1//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements semantic analysis for declarations.
10//
11//===----------------------------------------------------------------------===//
12
13#include "TypeLocBuilder.h"
14#include "clang/AST/ASTConsumer.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/ASTLambda.h"
17#include "clang/AST/CXXInheritance.h"
18#include "clang/AST/CharUnits.h"
19#include "clang/AST/CommentDiagnostic.h"
20#include "clang/AST/Decl.h"
21#include "clang/AST/DeclCXX.h"
22#include "clang/AST/DeclObjC.h"
23#include "clang/AST/DeclTemplate.h"
24#include "clang/AST/EvaluatedExprVisitor.h"
25#include "clang/AST/Expr.h"
26#include "clang/AST/ExprCXX.h"
27#include "clang/AST/NonTrivialTypeVisitor.h"
28#include "clang/AST/Randstruct.h"
29#include "clang/AST/StmtCXX.h"
30#include "clang/AST/Type.h"
31#include "clang/Basic/Builtins.h"
32#include "clang/Basic/HLSLRuntime.h"
33#include "clang/Basic/PartialDiagnostic.h"
34#include "clang/Basic/SourceManager.h"
35#include "clang/Basic/TargetInfo.h"
36#include "clang/Lex/HeaderSearch.h" // TODO: Sema shouldn't depend on Lex
37#include "clang/Lex/Lexer.h" // TODO: Extract static functions to fix layering.
38#include "clang/Lex/ModuleLoader.h" // TODO: Sema shouldn't depend on Lex
39#include "clang/Lex/Preprocessor.h" // Included for isCodeCompletionEnabled()
40#include "clang/Sema/CXXFieldCollector.h"
41#include "clang/Sema/DeclSpec.h"
42#include "clang/Sema/DelayedDiagnostic.h"
43#include "clang/Sema/Initialization.h"
44#include "clang/Sema/Lookup.h"
45#include "clang/Sema/ParsedTemplate.h"
46#include "clang/Sema/Scope.h"
47#include "clang/Sema/ScopeInfo.h"
48#include "clang/Sema/SemaCUDA.h"
49#include "clang/Sema/SemaHLSL.h"
50#include "clang/Sema/SemaInternal.h"
51#include "clang/Sema/SemaObjC.h"
52#include "clang/Sema/SemaOpenMP.h"
53#include "clang/Sema/SemaPPC.h"
54#include "clang/Sema/SemaRISCV.h"
55#include "clang/Sema/SemaSwift.h"
56#include "clang/Sema/SemaWasm.h"
57#include "clang/Sema/Template.h"
58#include "llvm/ADT/STLForwardCompat.h"
59#include "llvm/ADT/SmallString.h"
60#include "llvm/ADT/StringExtras.h"
61#include "llvm/TargetParser/Triple.h"
62#include <algorithm>
63#include <cstring>
64#include <functional>
65#include <optional>
66#include <unordered_map>
67
68using namespace clang;
69using namespace sema;
70
71Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(Decl *Ptr, Decl *OwnedType) {
72 if (OwnedType) {
73 Decl *Group[2] = { OwnedType, Ptr };
74 return DeclGroupPtrTy::make(P: DeclGroupRef::Create(C&: Context, Decls: Group, NumDecls: 2));
75 }
76
77 return DeclGroupPtrTy::make(P: DeclGroupRef(Ptr));
78}
79
80namespace {
81
82class TypeNameValidatorCCC final : public CorrectionCandidateCallback {
83 public:
84 TypeNameValidatorCCC(bool AllowInvalid, bool WantClass = false,
85 bool AllowTemplates = false,
86 bool AllowNonTemplates = true)
87 : AllowInvalidDecl(AllowInvalid), WantClassName(WantClass),
88 AllowTemplates(AllowTemplates), AllowNonTemplates(AllowNonTemplates) {
89 WantExpressionKeywords = false;
90 WantCXXNamedCasts = false;
91 WantRemainingKeywords = false;
92 }
93
94 bool ValidateCandidate(const TypoCorrection &candidate) override {
95 if (NamedDecl *ND = candidate.getCorrectionDecl()) {
96 if (!AllowInvalidDecl && ND->isInvalidDecl())
97 return false;
98
99 if (getAsTypeTemplateDecl(D: ND))
100 return AllowTemplates;
101
102 bool IsType = isa<TypeDecl>(Val: ND) || isa<ObjCInterfaceDecl>(Val: ND);
103 if (!IsType)
104 return false;
105
106 if (AllowNonTemplates)
107 return true;
108
109 // An injected-class-name of a class template (specialization) is valid
110 // as a template or as a non-template.
111 if (AllowTemplates) {
112 auto *RD = dyn_cast<CXXRecordDecl>(Val: ND);
113 if (!RD || !RD->isInjectedClassName())
114 return false;
115 RD = cast<CXXRecordDecl>(Val: RD->getDeclContext());
116 return RD->getDescribedClassTemplate() ||
117 isa<ClassTemplateSpecializationDecl>(Val: RD);
118 }
119
120 return false;
121 }
122
123 return !WantClassName && candidate.isKeyword();
124 }
125
126 std::unique_ptr<CorrectionCandidateCallback> clone() override {
127 return std::make_unique<TypeNameValidatorCCC>(args&: *this);
128 }
129
130 private:
131 bool AllowInvalidDecl;
132 bool WantClassName;
133 bool AllowTemplates;
134 bool AllowNonTemplates;
135};
136
137} // end anonymous namespace
138
139namespace {
140enum class UnqualifiedTypeNameLookupResult {
141 NotFound,
142 FoundNonType,
143 FoundType
144};
145} // end anonymous namespace
146
147/// Tries to perform unqualified lookup of the type decls in bases for
148/// dependent class.
149/// \return \a NotFound if no any decls is found, \a FoundNotType if found not a
150/// type decl, \a FoundType if only type decls are found.
151static UnqualifiedTypeNameLookupResult
152lookupUnqualifiedTypeNameInBase(Sema &S, const IdentifierInfo &II,
153 SourceLocation NameLoc,
154 const CXXRecordDecl *RD) {
155 if (!RD->hasDefinition())
156 return UnqualifiedTypeNameLookupResult::NotFound;
157 // Look for type decls in base classes.
158 UnqualifiedTypeNameLookupResult FoundTypeDecl =
159 UnqualifiedTypeNameLookupResult::NotFound;
160 for (const auto &Base : RD->bases()) {
161 const CXXRecordDecl *BaseRD = nullptr;
162 if (auto *BaseTT = Base.getType()->getAs<TagType>())
163 BaseRD = BaseTT->getAsCXXRecordDecl();
164 else if (auto *TST = Base.getType()->getAs<TemplateSpecializationType>()) {
165 // Look for type decls in dependent base classes that have known primary
166 // templates.
167 if (!TST || !TST->isDependentType())
168 continue;
169 auto *TD = TST->getTemplateName().getAsTemplateDecl();
170 if (!TD)
171 continue;
172 if (auto *BasePrimaryTemplate =
173 dyn_cast_or_null<CXXRecordDecl>(Val: TD->getTemplatedDecl())) {
174 if (BasePrimaryTemplate->getCanonicalDecl() != RD->getCanonicalDecl())
175 BaseRD = BasePrimaryTemplate;
176 else if (auto *CTD = dyn_cast<ClassTemplateDecl>(Val: TD)) {
177 if (const ClassTemplatePartialSpecializationDecl *PS =
178 CTD->findPartialSpecialization(T: Base.getType()))
179 if (PS->getCanonicalDecl() != RD->getCanonicalDecl())
180 BaseRD = PS;
181 }
182 }
183 }
184 if (BaseRD) {
185 for (NamedDecl *ND : BaseRD->lookup(Name: &II)) {
186 if (!isa<TypeDecl>(Val: ND))
187 return UnqualifiedTypeNameLookupResult::FoundNonType;
188 FoundTypeDecl = UnqualifiedTypeNameLookupResult::FoundType;
189 }
190 if (FoundTypeDecl == UnqualifiedTypeNameLookupResult::NotFound) {
191 switch (lookupUnqualifiedTypeNameInBase(S, II, NameLoc, RD: BaseRD)) {
192 case UnqualifiedTypeNameLookupResult::FoundNonType:
193 return UnqualifiedTypeNameLookupResult::FoundNonType;
194 case UnqualifiedTypeNameLookupResult::FoundType:
195 FoundTypeDecl = UnqualifiedTypeNameLookupResult::FoundType;
196 break;
197 case UnqualifiedTypeNameLookupResult::NotFound:
198 break;
199 }
200 }
201 }
202 }
203
204 return FoundTypeDecl;
205}
206
207static ParsedType recoverFromTypeInKnownDependentBase(Sema &S,
208 const IdentifierInfo &II,
209 SourceLocation NameLoc) {
210 // Lookup in the parent class template context, if any.
211 const CXXRecordDecl *RD = nullptr;
212 UnqualifiedTypeNameLookupResult FoundTypeDecl =
213 UnqualifiedTypeNameLookupResult::NotFound;
214 for (DeclContext *DC = S.CurContext;
215 DC && FoundTypeDecl == UnqualifiedTypeNameLookupResult::NotFound;
216 DC = DC->getParent()) {
217 // Look for type decls in dependent base classes that have known primary
218 // templates.
219 RD = dyn_cast<CXXRecordDecl>(Val: DC);
220 if (RD && RD->getDescribedClassTemplate())
221 FoundTypeDecl = lookupUnqualifiedTypeNameInBase(S, II, NameLoc, RD);
222 }
223 if (FoundTypeDecl != UnqualifiedTypeNameLookupResult::FoundType)
224 return nullptr;
225
226 // We found some types in dependent base classes. Recover as if the user
227 // wrote 'typename MyClass::II' instead of 'II'. We'll fully resolve the
228 // lookup during template instantiation.
229 S.Diag(Loc: NameLoc, DiagID: diag::ext_found_in_dependent_base) << &II;
230
231 ASTContext &Context = S.Context;
232 auto *NNS = NestedNameSpecifier::Create(Context, Prefix: nullptr, Template: false,
233 T: cast<Type>(Val: Context.getRecordType(Decl: RD)));
234 QualType T =
235 Context.getDependentNameType(Keyword: ElaboratedTypeKeyword::Typename, NNS, Name: &II);
236
237 CXXScopeSpec SS;
238 SS.MakeTrivial(Context, Qualifier: NNS, R: SourceRange(NameLoc));
239
240 TypeLocBuilder Builder;
241 DependentNameTypeLoc DepTL = Builder.push<DependentNameTypeLoc>(T);
242 DepTL.setNameLoc(NameLoc);
243 DepTL.setElaboratedKeywordLoc(SourceLocation());
244 DepTL.setQualifierLoc(SS.getWithLocInContext(Context));
245 return S.CreateParsedType(T, TInfo: Builder.getTypeSourceInfo(Context, T));
246}
247
248/// Build a ParsedType for a simple-type-specifier with a nested-name-specifier.
249static ParsedType buildNamedType(Sema &S, const CXXScopeSpec *SS, QualType T,
250 SourceLocation NameLoc,
251 bool WantNontrivialTypeSourceInfo = true) {
252 switch (T->getTypeClass()) {
253 case Type::DeducedTemplateSpecialization:
254 case Type::Enum:
255 case Type::InjectedClassName:
256 case Type::Record:
257 case Type::Typedef:
258 case Type::UnresolvedUsing:
259 case Type::Using:
260 break;
261 // These can never be qualified so an ElaboratedType node
262 // would carry no additional meaning.
263 case Type::ObjCInterface:
264 case Type::ObjCTypeParam:
265 case Type::TemplateTypeParm:
266 return ParsedType::make(P: T);
267 default:
268 llvm_unreachable("Unexpected Type Class");
269 }
270
271 if (!SS || SS->isEmpty())
272 return ParsedType::make(P: S.Context.getElaboratedType(
273 Keyword: ElaboratedTypeKeyword::None, NNS: nullptr, NamedType: T, OwnedTagDecl: nullptr));
274
275 QualType ElTy = S.getElaboratedType(Keyword: ElaboratedTypeKeyword::None, SS: *SS, T);
276 if (!WantNontrivialTypeSourceInfo)
277 return ParsedType::make(P: ElTy);
278
279 TypeLocBuilder Builder;
280 Builder.pushTypeSpec(T).setNameLoc(NameLoc);
281 ElaboratedTypeLoc ElabTL = Builder.push<ElaboratedTypeLoc>(T: ElTy);
282 ElabTL.setElaboratedKeywordLoc(SourceLocation());
283 ElabTL.setQualifierLoc(SS->getWithLocInContext(Context&: S.Context));
284 return S.CreateParsedType(T: ElTy, TInfo: Builder.getTypeSourceInfo(Context&: S.Context, T: ElTy));
285}
286
287ParsedType Sema::getTypeName(const IdentifierInfo &II, SourceLocation NameLoc,
288 Scope *S, CXXScopeSpec *SS, bool isClassName,
289 bool HasTrailingDot, ParsedType ObjectTypePtr,
290 bool IsCtorOrDtorName,
291 bool WantNontrivialTypeSourceInfo,
292 bool IsClassTemplateDeductionContext,
293 ImplicitTypenameContext AllowImplicitTypename,
294 IdentifierInfo **CorrectedII) {
295 // FIXME: Consider allowing this outside C++1z mode as an extension.
296 bool AllowDeducedTemplate = IsClassTemplateDeductionContext &&
297 getLangOpts().CPlusPlus17 && !IsCtorOrDtorName &&
298 !isClassName && !HasTrailingDot;
299
300 // Determine where we will perform name lookup.
301 DeclContext *LookupCtx = nullptr;
302 if (ObjectTypePtr) {
303 QualType ObjectType = ObjectTypePtr.get();
304 if (ObjectType->isRecordType())
305 LookupCtx = computeDeclContext(T: ObjectType);
306 } else if (SS && SS->isNotEmpty()) {
307 LookupCtx = computeDeclContext(SS: *SS, EnteringContext: false);
308
309 if (!LookupCtx) {
310 if (isDependentScopeSpecifier(SS: *SS)) {
311 // C++ [temp.res]p3:
312 // A qualified-id that refers to a type and in which the
313 // nested-name-specifier depends on a template-parameter (14.6.2)
314 // shall be prefixed by the keyword typename to indicate that the
315 // qualified-id denotes a type, forming an
316 // elaborated-type-specifier (7.1.5.3).
317 //
318 // We therefore do not perform any name lookup if the result would
319 // refer to a member of an unknown specialization.
320 // In C++2a, in several contexts a 'typename' is not required. Also
321 // allow this as an extension.
322 if (AllowImplicitTypename == ImplicitTypenameContext::No &&
323 !isClassName && !IsCtorOrDtorName)
324 return nullptr;
325 bool IsImplicitTypename = !isClassName && !IsCtorOrDtorName;
326 if (IsImplicitTypename) {
327 SourceLocation QualifiedLoc = SS->getRange().getBegin();
328 if (getLangOpts().CPlusPlus20)
329 Diag(Loc: QualifiedLoc, DiagID: diag::warn_cxx17_compat_implicit_typename);
330 else
331 Diag(Loc: QualifiedLoc, DiagID: diag::ext_implicit_typename)
332 << SS->getScopeRep() << II.getName()
333 << FixItHint::CreateInsertion(InsertionLoc: QualifiedLoc, Code: "typename ");
334 }
335
336 // We know from the grammar that this name refers to a type,
337 // so build a dependent node to describe the type.
338 if (WantNontrivialTypeSourceInfo)
339 return ActOnTypenameType(S, TypenameLoc: SourceLocation(), SS: *SS, II, IdLoc: NameLoc,
340 IsImplicitTypename: (ImplicitTypenameContext)IsImplicitTypename)
341 .get();
342
343 NestedNameSpecifierLoc QualifierLoc = SS->getWithLocInContext(Context);
344 QualType T = CheckTypenameType(
345 Keyword: IsImplicitTypename ? ElaboratedTypeKeyword::Typename
346 : ElaboratedTypeKeyword::None,
347 KeywordLoc: SourceLocation(), QualifierLoc, II, IILoc: NameLoc);
348 return ParsedType::make(P: T);
349 }
350
351 return nullptr;
352 }
353
354 if (!LookupCtx->isDependentContext() &&
355 RequireCompleteDeclContext(SS&: *SS, DC: LookupCtx))
356 return nullptr;
357 }
358
359 // FIXME: LookupNestedNameSpecifierName isn't the right kind of
360 // lookup for class-names.
361 LookupNameKind Kind = isClassName ? LookupNestedNameSpecifierName :
362 LookupOrdinaryName;
363 LookupResult Result(*this, &II, NameLoc, Kind);
364 if (LookupCtx) {
365 // Perform "qualified" name lookup into the declaration context we
366 // computed, which is either the type of the base of a member access
367 // expression or the declaration context associated with a prior
368 // nested-name-specifier.
369 LookupQualifiedName(R&: Result, LookupCtx);
370
371 if (ObjectTypePtr && Result.empty()) {
372 // C++ [basic.lookup.classref]p3:
373 // If the unqualified-id is ~type-name, the type-name is looked up
374 // in the context of the entire postfix-expression. If the type T of
375 // the object expression is of a class type C, the type-name is also
376 // looked up in the scope of class C. At least one of the lookups shall
377 // find a name that refers to (possibly cv-qualified) T.
378 LookupName(R&: Result, S);
379 }
380 } else {
381 // Perform unqualified name lookup.
382 LookupName(R&: Result, S);
383
384 // For unqualified lookup in a class template in MSVC mode, look into
385 // dependent base classes where the primary class template is known.
386 if (Result.empty() && getLangOpts().MSVCCompat && (!SS || SS->isEmpty())) {
387 if (ParsedType TypeInBase =
388 recoverFromTypeInKnownDependentBase(S&: *this, II, NameLoc))
389 return TypeInBase;
390 }
391 }
392
393 NamedDecl *IIDecl = nullptr;
394 UsingShadowDecl *FoundUsingShadow = nullptr;
395 switch (Result.getResultKind()) {
396 case LookupResult::NotFound:
397 if (CorrectedII) {
398 TypeNameValidatorCCC CCC(/*AllowInvalid=*/true, isClassName,
399 AllowDeducedTemplate);
400 TypoCorrection Correction = CorrectTypo(Typo: Result.getLookupNameInfo(), LookupKind: Kind,
401 S, SS, CCC, Mode: CTK_ErrorRecovery);
402 IdentifierInfo *NewII = Correction.getCorrectionAsIdentifierInfo();
403 TemplateTy Template;
404 bool MemberOfUnknownSpecialization;
405 UnqualifiedId TemplateName;
406 TemplateName.setIdentifier(Id: NewII, IdLoc: NameLoc);
407 NestedNameSpecifier *NNS = Correction.getCorrectionSpecifier();
408 CXXScopeSpec NewSS, *NewSSPtr = SS;
409 if (SS && NNS) {
410 NewSS.MakeTrivial(Context, Qualifier: NNS, R: SourceRange(NameLoc));
411 NewSSPtr = &NewSS;
412 }
413 if (Correction && (NNS || NewII != &II) &&
414 // Ignore a correction to a template type as the to-be-corrected
415 // identifier is not a template (typo correction for template names
416 // is handled elsewhere).
417 !(getLangOpts().CPlusPlus && NewSSPtr &&
418 isTemplateName(S, SS&: *NewSSPtr, hasTemplateKeyword: false, Name: TemplateName, ObjectType: nullptr, EnteringContext: false,
419 Template, MemberOfUnknownSpecialization))) {
420 ParsedType Ty = getTypeName(II: *NewII, NameLoc, S, SS: NewSSPtr,
421 isClassName, HasTrailingDot, ObjectTypePtr,
422 IsCtorOrDtorName,
423 WantNontrivialTypeSourceInfo,
424 IsClassTemplateDeductionContext);
425 if (Ty) {
426 diagnoseTypo(Correction,
427 TypoDiag: PDiag(DiagID: diag::err_unknown_type_or_class_name_suggest)
428 << Result.getLookupName() << isClassName);
429 if (SS && NNS)
430 SS->MakeTrivial(Context, Qualifier: NNS, R: SourceRange(NameLoc));
431 *CorrectedII = NewII;
432 return Ty;
433 }
434 }
435 }
436 Result.suppressDiagnostics();
437 return nullptr;
438 case LookupResult::NotFoundInCurrentInstantiation:
439 if (AllowImplicitTypename == ImplicitTypenameContext::Yes) {
440 QualType T = Context.getDependentNameType(Keyword: ElaboratedTypeKeyword::None,
441 NNS: SS->getScopeRep(), Name: &II);
442 TypeLocBuilder TLB;
443 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(T);
444 TL.setElaboratedKeywordLoc(SourceLocation());
445 TL.setQualifierLoc(SS->getWithLocInContext(Context));
446 TL.setNameLoc(NameLoc);
447 return CreateParsedType(T, TInfo: TLB.getTypeSourceInfo(Context, T));
448 }
449 [[fallthrough]];
450 case LookupResult::FoundOverloaded:
451 case LookupResult::FoundUnresolvedValue:
452 Result.suppressDiagnostics();
453 return nullptr;
454
455 case LookupResult::Ambiguous:
456 // Recover from type-hiding ambiguities by hiding the type. We'll
457 // do the lookup again when looking for an object, and we can
458 // diagnose the error then. If we don't do this, then the error
459 // about hiding the type will be immediately followed by an error
460 // that only makes sense if the identifier was treated like a type.
461 if (Result.getAmbiguityKind() == LookupResult::AmbiguousTagHiding) {
462 Result.suppressDiagnostics();
463 return nullptr;
464 }
465
466 // Look to see if we have a type anywhere in the list of results.
467 for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end();
468 Res != ResEnd; ++Res) {
469 NamedDecl *RealRes = (*Res)->getUnderlyingDecl();
470 if (isa<TypeDecl, ObjCInterfaceDecl, UnresolvedUsingIfExistsDecl>(
471 Val: RealRes) ||
472 (AllowDeducedTemplate && getAsTypeTemplateDecl(D: RealRes))) {
473 if (!IIDecl ||
474 // Make the selection of the recovery decl deterministic.
475 RealRes->getLocation() < IIDecl->getLocation()) {
476 IIDecl = RealRes;
477 FoundUsingShadow = dyn_cast<UsingShadowDecl>(Val: *Res);
478 }
479 }
480 }
481
482 if (!IIDecl) {
483 // None of the entities we found is a type, so there is no way
484 // to even assume that the result is a type. In this case, don't
485 // complain about the ambiguity. The parser will either try to
486 // perform this lookup again (e.g., as an object name), which
487 // will produce the ambiguity, or will complain that it expected
488 // a type name.
489 Result.suppressDiagnostics();
490 return nullptr;
491 }
492
493 // We found a type within the ambiguous lookup; diagnose the
494 // ambiguity and then return that type. This might be the right
495 // answer, or it might not be, but it suppresses any attempt to
496 // perform the name lookup again.
497 break;
498
499 case LookupResult::Found:
500 IIDecl = Result.getFoundDecl();
501 FoundUsingShadow = dyn_cast<UsingShadowDecl>(Val: *Result.begin());
502 break;
503 }
504
505 assert(IIDecl && "Didn't find decl");
506
507 QualType T;
508 if (TypeDecl *TD = dyn_cast<TypeDecl>(Val: IIDecl)) {
509 // C++ [class.qual]p2: A lookup that would find the injected-class-name
510 // instead names the constructors of the class, except when naming a class.
511 // This is ill-formed when we're not actually forming a ctor or dtor name.
512 auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(Val: LookupCtx);
513 auto *FoundRD = dyn_cast<CXXRecordDecl>(Val: TD);
514 if (!isClassName && !IsCtorOrDtorName && LookupRD && FoundRD &&
515 FoundRD->isInjectedClassName() &&
516 declaresSameEntity(D1: LookupRD, D2: cast<Decl>(Val: FoundRD->getParent())))
517 Diag(Loc: NameLoc, DiagID: diag::err_out_of_line_qualified_id_type_names_constructor)
518 << &II << /*Type*/1;
519
520 DiagnoseUseOfDecl(D: IIDecl, Locs: NameLoc);
521
522 T = Context.getTypeDeclType(Decl: TD);
523 MarkAnyDeclReferenced(Loc: TD->getLocation(), D: TD, /*OdrUse=*/MightBeOdrUse: false);
524 } else if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(Val: IIDecl)) {
525 (void)DiagnoseUseOfDecl(D: IDecl, Locs: NameLoc);
526 if (!HasTrailingDot)
527 T = Context.getObjCInterfaceType(Decl: IDecl);
528 FoundUsingShadow = nullptr; // FIXME: Target must be a TypeDecl.
529 } else if (auto *UD = dyn_cast<UnresolvedUsingIfExistsDecl>(Val: IIDecl)) {
530 (void)DiagnoseUseOfDecl(D: UD, Locs: NameLoc);
531 // Recover with 'int'
532 return ParsedType::make(P: Context.IntTy);
533 } else if (AllowDeducedTemplate) {
534 if (auto *TD = getAsTypeTemplateDecl(D: IIDecl)) {
535 assert(!FoundUsingShadow || FoundUsingShadow->getTargetDecl() == TD);
536 TemplateName Template = Context.getQualifiedTemplateName(
537 NNS: SS ? SS->getScopeRep() : nullptr, /*TemplateKeyword=*/false,
538 Template: FoundUsingShadow ? TemplateName(FoundUsingShadow) : TemplateName(TD));
539 T = Context.getDeducedTemplateSpecializationType(Template, DeducedType: QualType(),
540 IsDependent: false);
541 // Don't wrap in a further UsingType.
542 FoundUsingShadow = nullptr;
543 }
544 }
545
546 if (T.isNull()) {
547 // If it's not plausibly a type, suppress diagnostics.
548 Result.suppressDiagnostics();
549 return nullptr;
550 }
551
552 if (FoundUsingShadow)
553 T = Context.getUsingType(Found: FoundUsingShadow, Underlying: T);
554
555 return buildNamedType(S&: *this, SS, T, NameLoc, WantNontrivialTypeSourceInfo);
556}
557
558// Builds a fake NNS for the given decl context.
559static NestedNameSpecifier *
560synthesizeCurrentNestedNameSpecifier(ASTContext &Context, DeclContext *DC) {
561 for (;; DC = DC->getLookupParent()) {
562 DC = DC->getPrimaryContext();
563 auto *ND = dyn_cast<NamespaceDecl>(Val: DC);
564 if (ND && !ND->isInline() && !ND->isAnonymousNamespace())
565 return NestedNameSpecifier::Create(Context, Prefix: nullptr, NS: ND);
566 else if (auto *RD = dyn_cast<CXXRecordDecl>(Val: DC))
567 return NestedNameSpecifier::Create(Context, Prefix: nullptr, Template: RD->isTemplateDecl(),
568 T: RD->getTypeForDecl());
569 else if (isa<TranslationUnitDecl>(Val: DC))
570 return NestedNameSpecifier::GlobalSpecifier(Context);
571 }
572 llvm_unreachable("something isn't in TU scope?");
573}
574
575/// Find the parent class with dependent bases of the innermost enclosing method
576/// context. Do not look for enclosing CXXRecordDecls directly, or we will end
577/// up allowing unqualified dependent type names at class-level, which MSVC
578/// correctly rejects.
579static const CXXRecordDecl *
580findRecordWithDependentBasesOfEnclosingMethod(const DeclContext *DC) {
581 for (; DC && DC->isDependentContext(); DC = DC->getLookupParent()) {
582 DC = DC->getPrimaryContext();
583 if (const auto *MD = dyn_cast<CXXMethodDecl>(Val: DC))
584 if (MD->getParent()->hasAnyDependentBases())
585 return MD->getParent();
586 }
587 return nullptr;
588}
589
590ParsedType Sema::ActOnMSVCUnknownTypeName(const IdentifierInfo &II,
591 SourceLocation NameLoc,
592 bool IsTemplateTypeArg) {
593 assert(getLangOpts().MSVCCompat && "shouldn't be called in non-MSVC mode");
594
595 NestedNameSpecifier *NNS = nullptr;
596 if (IsTemplateTypeArg && getCurScope()->isTemplateParamScope()) {
597 // If we weren't able to parse a default template argument, delay lookup
598 // until instantiation time by making a non-dependent DependentTypeName. We
599 // pretend we saw a NestedNameSpecifier referring to the current scope, and
600 // lookup is retried.
601 // FIXME: This hurts our diagnostic quality, since we get errors like "no
602 // type named 'Foo' in 'current_namespace'" when the user didn't write any
603 // name specifiers.
604 NNS = synthesizeCurrentNestedNameSpecifier(Context, DC: CurContext);
605 Diag(Loc: NameLoc, DiagID: diag::ext_ms_delayed_template_argument) << &II;
606 } else if (const CXXRecordDecl *RD =
607 findRecordWithDependentBasesOfEnclosingMethod(DC: CurContext)) {
608 // Build a DependentNameType that will perform lookup into RD at
609 // instantiation time.
610 NNS = NestedNameSpecifier::Create(Context, Prefix: nullptr, Template: RD->isTemplateDecl(),
611 T: RD->getTypeForDecl());
612
613 // Diagnose that this identifier was undeclared, and retry the lookup during
614 // template instantiation.
615 Diag(Loc: NameLoc, DiagID: diag::ext_undeclared_unqual_id_with_dependent_base) << &II
616 << RD;
617 } else {
618 // This is not a situation that we should recover from.
619 return ParsedType();
620 }
621
622 QualType T =
623 Context.getDependentNameType(Keyword: ElaboratedTypeKeyword::None, NNS, Name: &II);
624
625 // Build type location information. We synthesized the qualifier, so we have
626 // to build a fake NestedNameSpecifierLoc.
627 NestedNameSpecifierLocBuilder NNSLocBuilder;
628 NNSLocBuilder.MakeTrivial(Context, Qualifier: NNS, R: SourceRange(NameLoc));
629 NestedNameSpecifierLoc QualifierLoc = NNSLocBuilder.getWithLocInContext(Context);
630
631 TypeLocBuilder Builder;
632 DependentNameTypeLoc DepTL = Builder.push<DependentNameTypeLoc>(T);
633 DepTL.setNameLoc(NameLoc);
634 DepTL.setElaboratedKeywordLoc(SourceLocation());
635 DepTL.setQualifierLoc(QualifierLoc);
636 return CreateParsedType(T, TInfo: Builder.getTypeSourceInfo(Context, T));
637}
638
639DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) {
640 // Do a tag name lookup in this scope.
641 LookupResult R(*this, &II, SourceLocation(), LookupTagName);
642 LookupName(R, S, AllowBuiltinCreation: false);
643 R.suppressDiagnostics();
644 if (R.getResultKind() == LookupResult::Found)
645 if (const TagDecl *TD = R.getAsSingle<TagDecl>()) {
646 switch (TD->getTagKind()) {
647 case TagTypeKind::Struct:
648 return DeclSpec::TST_struct;
649 case TagTypeKind::Interface:
650 return DeclSpec::TST_interface;
651 case TagTypeKind::Union:
652 return DeclSpec::TST_union;
653 case TagTypeKind::Class:
654 return DeclSpec::TST_class;
655 case TagTypeKind::Enum:
656 return DeclSpec::TST_enum;
657 }
658 }
659
660 return DeclSpec::TST_unspecified;
661}
662
663bool Sema::isMicrosoftMissingTypename(const CXXScopeSpec *SS, Scope *S) {
664 if (CurContext->isRecord()) {
665 if (SS->getScopeRep()->getKind() == NestedNameSpecifier::Super)
666 return true;
667
668 const Type *Ty = SS->getScopeRep()->getAsType();
669
670 CXXRecordDecl *RD = cast<CXXRecordDecl>(Val: CurContext);
671 for (const auto &Base : RD->bases())
672 if (Ty && Context.hasSameUnqualifiedType(T1: QualType(Ty, 1), T2: Base.getType()))
673 return true;
674 return S->isFunctionPrototypeScope();
675 }
676 return CurContext->isFunctionOrMethod() || S->isFunctionPrototypeScope();
677}
678
679void Sema::DiagnoseUnknownTypeName(IdentifierInfo *&II,
680 SourceLocation IILoc,
681 Scope *S,
682 CXXScopeSpec *SS,
683 ParsedType &SuggestedType,
684 bool IsTemplateName) {
685 // Don't report typename errors for editor placeholders.
686 if (II->isEditorPlaceholder())
687 return;
688 // We don't have anything to suggest (yet).
689 SuggestedType = nullptr;
690
691 // There may have been a typo in the name of the type. Look up typo
692 // results, in case we have something that we can suggest.
693 TypeNameValidatorCCC CCC(/*AllowInvalid=*/false, /*WantClass=*/false,
694 /*AllowTemplates=*/IsTemplateName,
695 /*AllowNonTemplates=*/!IsTemplateName);
696 if (TypoCorrection Corrected =
697 CorrectTypo(Typo: DeclarationNameInfo(II, IILoc), LookupKind: LookupOrdinaryName, S, SS,
698 CCC, Mode: CTK_ErrorRecovery)) {
699 // FIXME: Support error recovery for the template-name case.
700 bool CanRecover = !IsTemplateName;
701 if (Corrected.isKeyword()) {
702 // We corrected to a keyword.
703 diagnoseTypo(Correction: Corrected,
704 TypoDiag: PDiag(DiagID: IsTemplateName ? diag::err_no_template_suggest
705 : diag::err_unknown_typename_suggest)
706 << II);
707 II = Corrected.getCorrectionAsIdentifierInfo();
708 } else {
709 // We found a similarly-named type or interface; suggest that.
710 if (!SS || !SS->isSet()) {
711 diagnoseTypo(Correction: Corrected,
712 TypoDiag: PDiag(DiagID: IsTemplateName ? diag::err_no_template_suggest
713 : diag::err_unknown_typename_suggest)
714 << II, ErrorRecovery: CanRecover);
715 } else if (DeclContext *DC = computeDeclContext(SS: *SS, EnteringContext: false)) {
716 std::string CorrectedStr(Corrected.getAsString(LO: getLangOpts()));
717 bool DroppedSpecifier =
718 Corrected.WillReplaceSpecifier() && II->getName() == CorrectedStr;
719 diagnoseTypo(Correction: Corrected,
720 TypoDiag: PDiag(DiagID: IsTemplateName
721 ? diag::err_no_member_template_suggest
722 : diag::err_unknown_nested_typename_suggest)
723 << II << DC << DroppedSpecifier << SS->getRange(),
724 ErrorRecovery: CanRecover);
725 } else {
726 llvm_unreachable("could not have corrected a typo here");
727 }
728
729 if (!CanRecover)
730 return;
731
732 CXXScopeSpec tmpSS;
733 if (Corrected.getCorrectionSpecifier())
734 tmpSS.MakeTrivial(Context, Qualifier: Corrected.getCorrectionSpecifier(),
735 R: SourceRange(IILoc));
736 // FIXME: Support class template argument deduction here.
737 SuggestedType =
738 getTypeName(II: *Corrected.getCorrectionAsIdentifierInfo(), NameLoc: IILoc, S,
739 SS: tmpSS.isSet() ? &tmpSS : SS, isClassName: false, HasTrailingDot: false, ObjectTypePtr: nullptr,
740 /*IsCtorOrDtorName=*/false,
741 /*WantNontrivialTypeSourceInfo=*/true);
742 }
743 return;
744 }
745
746 if (getLangOpts().CPlusPlus && !IsTemplateName) {
747 // See if II is a class template that the user forgot to pass arguments to.
748 UnqualifiedId Name;
749 Name.setIdentifier(Id: II, IdLoc: IILoc);
750 CXXScopeSpec EmptySS;
751 TemplateTy TemplateResult;
752 bool MemberOfUnknownSpecialization;
753 if (isTemplateName(S, SS&: SS ? *SS : EmptySS, /*hasTemplateKeyword=*/false,
754 Name, ObjectType: nullptr, EnteringContext: true, Template&: TemplateResult,
755 MemberOfUnknownSpecialization) == TNK_Type_template) {
756 diagnoseMissingTemplateArguments(Name: TemplateResult.get(), Loc: IILoc);
757 return;
758 }
759 }
760
761 // FIXME: Should we move the logic that tries to recover from a missing tag
762 // (struct, union, enum) from Parser::ParseImplicitInt here, instead?
763
764 if (!SS || (!SS->isSet() && !SS->isInvalid()))
765 Diag(Loc: IILoc, DiagID: IsTemplateName ? diag::err_no_template
766 : diag::err_unknown_typename)
767 << II;
768 else if (DeclContext *DC = computeDeclContext(SS: *SS, EnteringContext: false))
769 Diag(Loc: IILoc, DiagID: IsTemplateName ? diag::err_no_member_template
770 : diag::err_typename_nested_not_found)
771 << II << DC << SS->getRange();
772 else if (SS->isValid() && SS->getScopeRep()->containsErrors()) {
773 SuggestedType =
774 ActOnTypenameType(S, TypenameLoc: SourceLocation(), SS: *SS, II: *II, IdLoc: IILoc).get();
775 } else if (isDependentScopeSpecifier(SS: *SS)) {
776 unsigned DiagID = diag::err_typename_missing;
777 if (getLangOpts().MSVCCompat && isMicrosoftMissingTypename(SS, S))
778 DiagID = diag::ext_typename_missing;
779
780 Diag(Loc: SS->getRange().getBegin(), DiagID)
781 << SS->getScopeRep() << II->getName()
782 << SourceRange(SS->getRange().getBegin(), IILoc)
783 << FixItHint::CreateInsertion(InsertionLoc: SS->getRange().getBegin(), Code: "typename ");
784 SuggestedType = ActOnTypenameType(S, TypenameLoc: SourceLocation(),
785 SS: *SS, II: *II, IdLoc: IILoc).get();
786 } else {
787 assert(SS && SS->isInvalid() &&
788 "Invalid scope specifier has already been diagnosed");
789 }
790}
791
792/// Determine whether the given result set contains either a type name
793/// or
794static bool isResultTypeOrTemplate(LookupResult &R, const Token &NextToken) {
795 bool CheckTemplate = R.getSema().getLangOpts().CPlusPlus &&
796 NextToken.is(K: tok::less);
797
798 for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I) {
799 if (isa<TypeDecl>(Val: *I) || isa<ObjCInterfaceDecl>(Val: *I))
800 return true;
801
802 if (CheckTemplate && isa<TemplateDecl>(Val: *I))
803 return true;
804 }
805
806 return false;
807}
808
809static bool isTagTypeWithMissingTag(Sema &SemaRef, LookupResult &Result,
810 Scope *S, CXXScopeSpec &SS,
811 IdentifierInfo *&Name,
812 SourceLocation NameLoc) {
813 LookupResult R(SemaRef, Name, NameLoc, Sema::LookupTagName);
814 SemaRef.LookupParsedName(R, S, SS: &SS, /*ObjectType=*/QualType());
815 if (TagDecl *Tag = R.getAsSingle<TagDecl>()) {
816 StringRef FixItTagName;
817 switch (Tag->getTagKind()) {
818 case TagTypeKind::Class:
819 FixItTagName = "class ";
820 break;
821
822 case TagTypeKind::Enum:
823 FixItTagName = "enum ";
824 break;
825
826 case TagTypeKind::Struct:
827 FixItTagName = "struct ";
828 break;
829
830 case TagTypeKind::Interface:
831 FixItTagName = "__interface ";
832 break;
833
834 case TagTypeKind::Union:
835 FixItTagName = "union ";
836 break;
837 }
838
839 StringRef TagName = FixItTagName.drop_back();
840 SemaRef.Diag(Loc: NameLoc, DiagID: diag::err_use_of_tag_name_without_tag)
841 << Name << TagName << SemaRef.getLangOpts().CPlusPlus
842 << FixItHint::CreateInsertion(InsertionLoc: NameLoc, Code: FixItTagName);
843
844 for (LookupResult::iterator I = Result.begin(), IEnd = Result.end();
845 I != IEnd; ++I)
846 SemaRef.Diag(Loc: (*I)->getLocation(), DiagID: diag::note_decl_hiding_tag_type)
847 << Name << TagName;
848
849 // Replace lookup results with just the tag decl.
850 Result.clear(Kind: Sema::LookupTagName);
851 SemaRef.LookupParsedName(R&: Result, S, SS: &SS, /*ObjectType=*/QualType());
852 return true;
853 }
854
855 return false;
856}
857
858Sema::NameClassification Sema::ClassifyName(Scope *S, CXXScopeSpec &SS,
859 IdentifierInfo *&Name,
860 SourceLocation NameLoc,
861 const Token &NextToken,
862 CorrectionCandidateCallback *CCC) {
863 DeclarationNameInfo NameInfo(Name, NameLoc);
864 ObjCMethodDecl *CurMethod = getCurMethodDecl();
865
866 assert(NextToken.isNot(tok::coloncolon) &&
867 "parse nested name specifiers before calling ClassifyName");
868 if (getLangOpts().CPlusPlus && SS.isSet() &&
869 isCurrentClassName(II: *Name, S, SS: &SS)) {
870 // Per [class.qual]p2, this names the constructors of SS, not the
871 // injected-class-name. We don't have a classification for that.
872 // There's not much point caching this result, since the parser
873 // will reject it later.
874 return NameClassification::Unknown();
875 }
876
877 LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
878 LookupParsedName(R&: Result, S, SS: &SS, /*ObjectType=*/QualType(),
879 /*AllowBuiltinCreation=*/!CurMethod);
880
881 if (SS.isInvalid())
882 return NameClassification::Error();
883
884 // For unqualified lookup in a class template in MSVC mode, look into
885 // dependent base classes where the primary class template is known.
886 if (Result.empty() && SS.isEmpty() && getLangOpts().MSVCCompat) {
887 if (ParsedType TypeInBase =
888 recoverFromTypeInKnownDependentBase(S&: *this, II: *Name, NameLoc))
889 return TypeInBase;
890 }
891
892 // Perform lookup for Objective-C instance variables (including automatically
893 // synthesized instance variables), if we're in an Objective-C method.
894 // FIXME: This lookup really, really needs to be folded in to the normal
895 // unqualified lookup mechanism.
896 if (SS.isEmpty() && CurMethod && !isResultTypeOrTemplate(R&: Result, NextToken)) {
897 DeclResult Ivar = ObjC().LookupIvarInObjCMethod(Lookup&: Result, S, II: Name);
898 if (Ivar.isInvalid())
899 return NameClassification::Error();
900 if (Ivar.isUsable())
901 return NameClassification::NonType(D: cast<NamedDecl>(Val: Ivar.get()));
902
903 // We defer builtin creation until after ivar lookup inside ObjC methods.
904 if (Result.empty())
905 LookupBuiltin(R&: Result);
906 }
907
908 bool SecondTry = false;
909 bool IsFilteredTemplateName = false;
910
911Corrected:
912 switch (Result.getResultKind()) {
913 case LookupResult::NotFound:
914 // If an unqualified-id is followed by a '(', then we have a function
915 // call.
916 if (SS.isEmpty() && NextToken.is(K: tok::l_paren)) {
917 // In C++, this is an ADL-only call.
918 // FIXME: Reference?
919 if (getLangOpts().CPlusPlus)
920 return NameClassification::UndeclaredNonType();
921
922 // C90 6.3.2.2:
923 // If the expression that precedes the parenthesized argument list in a
924 // function call consists solely of an identifier, and if no
925 // declaration is visible for this identifier, the identifier is
926 // implicitly declared exactly as if, in the innermost block containing
927 // the function call, the declaration
928 //
929 // extern int identifier ();
930 //
931 // appeared.
932 //
933 // We also allow this in C99 as an extension. However, this is not
934 // allowed in all language modes as functions without prototypes may not
935 // be supported.
936 if (getLangOpts().implicitFunctionsAllowed()) {
937 if (NamedDecl *D = ImplicitlyDefineFunction(Loc: NameLoc, II&: *Name, S))
938 return NameClassification::NonType(D);
939 }
940 }
941
942 if (getLangOpts().CPlusPlus20 && SS.isEmpty() && NextToken.is(K: tok::less)) {
943 // In C++20 onwards, this could be an ADL-only call to a function
944 // template, and we're required to assume that this is a template name.
945 //
946 // FIXME: Find a way to still do typo correction in this case.
947 TemplateName Template =
948 Context.getAssumedTemplateName(Name: NameInfo.getName());
949 return NameClassification::UndeclaredTemplate(Name: Template);
950 }
951
952 // In C, we first see whether there is a tag type by the same name, in
953 // which case it's likely that the user just forgot to write "enum",
954 // "struct", or "union".
955 if (!getLangOpts().CPlusPlus && !SecondTry &&
956 isTagTypeWithMissingTag(SemaRef&: *this, Result, S, SS, Name, NameLoc)) {
957 break;
958 }
959
960 // Perform typo correction to determine if there is another name that is
961 // close to this name.
962 if (!SecondTry && CCC) {
963 SecondTry = true;
964 if (TypoCorrection Corrected =
965 CorrectTypo(Typo: Result.getLookupNameInfo(), LookupKind: Result.getLookupKind(), S,
966 SS: &SS, CCC&: *CCC, Mode: CTK_ErrorRecovery)) {
967 unsigned UnqualifiedDiag = diag::err_undeclared_var_use_suggest;
968 unsigned QualifiedDiag = diag::err_no_member_suggest;
969
970 NamedDecl *FirstDecl = Corrected.getFoundDecl();
971 NamedDecl *UnderlyingFirstDecl = Corrected.getCorrectionDecl();
972 if (getLangOpts().CPlusPlus && NextToken.is(K: tok::less) &&
973 UnderlyingFirstDecl && isa<TemplateDecl>(Val: UnderlyingFirstDecl)) {
974 UnqualifiedDiag = diag::err_no_template_suggest;
975 QualifiedDiag = diag::err_no_member_template_suggest;
976 } else if (UnderlyingFirstDecl &&
977 (isa<TypeDecl>(Val: UnderlyingFirstDecl) ||
978 isa<ObjCInterfaceDecl>(Val: UnderlyingFirstDecl) ||
979 isa<ObjCCompatibleAliasDecl>(Val: UnderlyingFirstDecl))) {
980 UnqualifiedDiag = diag::err_unknown_typename_suggest;
981 QualifiedDiag = diag::err_unknown_nested_typename_suggest;
982 }
983
984 if (SS.isEmpty()) {
985 diagnoseTypo(Correction: Corrected, TypoDiag: PDiag(DiagID: UnqualifiedDiag) << Name);
986 } else {// FIXME: is this even reachable? Test it.
987 std::string CorrectedStr(Corrected.getAsString(LO: getLangOpts()));
988 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
989 Name->getName() == CorrectedStr;
990 diagnoseTypo(Correction: Corrected, TypoDiag: PDiag(DiagID: QualifiedDiag)
991 << Name << computeDeclContext(SS, EnteringContext: false)
992 << DroppedSpecifier << SS.getRange());
993 }
994
995 // Update the name, so that the caller has the new name.
996 Name = Corrected.getCorrectionAsIdentifierInfo();
997
998 // Typo correction corrected to a keyword.
999 if (Corrected.isKeyword())
1000 return Name;
1001
1002 // Also update the LookupResult...
1003 // FIXME: This should probably go away at some point
1004 Result.clear();
1005 Result.setLookupName(Corrected.getCorrection());
1006 if (FirstDecl)
1007 Result.addDecl(D: FirstDecl);
1008
1009 // If we found an Objective-C instance variable, let
1010 // LookupInObjCMethod build the appropriate expression to
1011 // reference the ivar.
1012 // FIXME: This is a gross hack.
1013 if (ObjCIvarDecl *Ivar = Result.getAsSingle<ObjCIvarDecl>()) {
1014 DeclResult R =
1015 ObjC().LookupIvarInObjCMethod(Lookup&: Result, S, II: Ivar->getIdentifier());
1016 if (R.isInvalid())
1017 return NameClassification::Error();
1018 if (R.isUsable())
1019 return NameClassification::NonType(D: Ivar);
1020 }
1021
1022 goto Corrected;
1023 }
1024 }
1025
1026 // We failed to correct; just fall through and let the parser deal with it.
1027 Result.suppressDiagnostics();
1028 return NameClassification::Unknown();
1029
1030 case LookupResult::NotFoundInCurrentInstantiation: {
1031 // We performed name lookup into the current instantiation, and there were
1032 // dependent bases, so we treat this result the same way as any other
1033 // dependent nested-name-specifier.
1034
1035 // C++ [temp.res]p2:
1036 // A name used in a template declaration or definition and that is
1037 // dependent on a template-parameter is assumed not to name a type
1038 // unless the applicable name lookup finds a type name or the name is
1039 // qualified by the keyword typename.
1040 //
1041 // FIXME: If the next token is '<', we might want to ask the parser to
1042 // perform some heroics to see if we actually have a
1043 // template-argument-list, which would indicate a missing 'template'
1044 // keyword here.
1045 return NameClassification::DependentNonType();
1046 }
1047
1048 case LookupResult::Found:
1049 case LookupResult::FoundOverloaded:
1050 case LookupResult::FoundUnresolvedValue:
1051 break;
1052
1053 case LookupResult::Ambiguous:
1054 if (getLangOpts().CPlusPlus && NextToken.is(K: tok::less) &&
1055 hasAnyAcceptableTemplateNames(R&: Result, /*AllowFunctionTemplates=*/true,
1056 /*AllowDependent=*/false)) {
1057 // C++ [temp.local]p3:
1058 // A lookup that finds an injected-class-name (10.2) can result in an
1059 // ambiguity in certain cases (for example, if it is found in more than
1060 // one base class). If all of the injected-class-names that are found
1061 // refer to specializations of the same class template, and if the name
1062 // is followed by a template-argument-list, the reference refers to the
1063 // class template itself and not a specialization thereof, and is not
1064 // ambiguous.
1065 //
1066 // This filtering can make an ambiguous result into an unambiguous one,
1067 // so try again after filtering out template names.
1068 FilterAcceptableTemplateNames(R&: Result);
1069 if (!Result.isAmbiguous()) {
1070 IsFilteredTemplateName = true;
1071 break;
1072 }
1073 }
1074
1075 // Diagnose the ambiguity and return an error.
1076 return NameClassification::Error();
1077 }
1078
1079 if (getLangOpts().CPlusPlus && NextToken.is(K: tok::less) &&
1080 (IsFilteredTemplateName ||
1081 hasAnyAcceptableTemplateNames(
1082 R&: Result, /*AllowFunctionTemplates=*/true,
1083 /*AllowDependent=*/false,
1084 /*AllowNonTemplateFunctions*/ SS.isEmpty() &&
1085 getLangOpts().CPlusPlus20))) {
1086 // C++ [temp.names]p3:
1087 // After name lookup (3.4) finds that a name is a template-name or that
1088 // an operator-function-id or a literal- operator-id refers to a set of
1089 // overloaded functions any member of which is a function template if
1090 // this is followed by a <, the < is always taken as the delimiter of a
1091 // template-argument-list and never as the less-than operator.
1092 // C++2a [temp.names]p2:
1093 // A name is also considered to refer to a template if it is an
1094 // unqualified-id followed by a < and name lookup finds either one
1095 // or more functions or finds nothing.
1096 if (!IsFilteredTemplateName)
1097 FilterAcceptableTemplateNames(R&: Result);
1098
1099 bool IsFunctionTemplate;
1100 bool IsVarTemplate;
1101 TemplateName Template;
1102 if (Result.end() - Result.begin() > 1) {
1103 IsFunctionTemplate = true;
1104 Template = Context.getOverloadedTemplateName(Begin: Result.begin(),
1105 End: Result.end());
1106 } else if (!Result.empty()) {
1107 auto *TD = cast<TemplateDecl>(Val: getAsTemplateNameDecl(
1108 D: *Result.begin(), /*AllowFunctionTemplates=*/true,
1109 /*AllowDependent=*/false));
1110 IsFunctionTemplate = isa<FunctionTemplateDecl>(Val: TD);
1111 IsVarTemplate = isa<VarTemplateDecl>(Val: TD);
1112
1113 UsingShadowDecl *FoundUsingShadow =
1114 dyn_cast<UsingShadowDecl>(Val: *Result.begin());
1115 assert(!FoundUsingShadow ||
1116 TD == cast<TemplateDecl>(FoundUsingShadow->getTargetDecl()));
1117 Template = Context.getQualifiedTemplateName(
1118 NNS: SS.getScopeRep(),
1119 /*TemplateKeyword=*/false,
1120 Template: FoundUsingShadow ? TemplateName(FoundUsingShadow) : TemplateName(TD));
1121 } else {
1122 // All results were non-template functions. This is a function template
1123 // name.
1124 IsFunctionTemplate = true;
1125 Template = Context.getAssumedTemplateName(Name: NameInfo.getName());
1126 }
1127
1128 if (IsFunctionTemplate) {
1129 // Function templates always go through overload resolution, at which
1130 // point we'll perform the various checks (e.g., accessibility) we need
1131 // to based on which function we selected.
1132 Result.suppressDiagnostics();
1133
1134 return NameClassification::FunctionTemplate(Name: Template);
1135 }
1136
1137 return IsVarTemplate ? NameClassification::VarTemplate(Name: Template)
1138 : NameClassification::TypeTemplate(Name: Template);
1139 }
1140
1141 auto BuildTypeFor = [&](TypeDecl *Type, NamedDecl *Found) {
1142 QualType T = Context.getTypeDeclType(Decl: Type);
1143 if (const auto *USD = dyn_cast<UsingShadowDecl>(Val: Found))
1144 T = Context.getUsingType(Found: USD, Underlying: T);
1145 return buildNamedType(S&: *this, SS: &SS, T, NameLoc);
1146 };
1147
1148 NamedDecl *FirstDecl = (*Result.begin())->getUnderlyingDecl();
1149 if (TypeDecl *Type = dyn_cast<TypeDecl>(Val: FirstDecl)) {
1150 DiagnoseUseOfDecl(D: Type, Locs: NameLoc);
1151 MarkAnyDeclReferenced(Loc: Type->getLocation(), D: Type, /*OdrUse=*/MightBeOdrUse: false);
1152 return BuildTypeFor(Type, *Result.begin());
1153 }
1154
1155 ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(Val: FirstDecl);
1156 if (!Class) {
1157 // FIXME: It's unfortunate that we don't have a Type node for handling this.
1158 if (ObjCCompatibleAliasDecl *Alias =
1159 dyn_cast<ObjCCompatibleAliasDecl>(Val: FirstDecl))
1160 Class = Alias->getClassInterface();
1161 }
1162
1163 if (Class) {
1164 DiagnoseUseOfDecl(D: Class, Locs: NameLoc);
1165
1166 if (NextToken.is(K: tok::period)) {
1167 // Interface. <something> is parsed as a property reference expression.
1168 // Just return "unknown" as a fall-through for now.
1169 Result.suppressDiagnostics();
1170 return NameClassification::Unknown();
1171 }
1172
1173 QualType T = Context.getObjCInterfaceType(Decl: Class);
1174 return ParsedType::make(P: T);
1175 }
1176
1177 if (isa<ConceptDecl>(Val: FirstDecl)) {
1178 // We want to preserve the UsingShadowDecl for concepts.
1179 if (auto *USD = dyn_cast<UsingShadowDecl>(Val: Result.getRepresentativeDecl()))
1180 return NameClassification::Concept(Name: TemplateName(USD));
1181 return NameClassification::Concept(
1182 Name: TemplateName(cast<TemplateDecl>(Val: FirstDecl)));
1183 }
1184
1185 if (auto *EmptyD = dyn_cast<UnresolvedUsingIfExistsDecl>(Val: FirstDecl)) {
1186 (void)DiagnoseUseOfDecl(D: EmptyD, Locs: NameLoc);
1187 return NameClassification::Error();
1188 }
1189
1190 // We can have a type template here if we're classifying a template argument.
1191 if (isa<TemplateDecl>(Val: FirstDecl) && !isa<FunctionTemplateDecl>(Val: FirstDecl) &&
1192 !isa<VarTemplateDecl>(Val: FirstDecl))
1193 return NameClassification::TypeTemplate(
1194 Name: TemplateName(cast<TemplateDecl>(Val: FirstDecl)));
1195
1196 // Check for a tag type hidden by a non-type decl in a few cases where it
1197 // seems likely a type is wanted instead of the non-type that was found.
1198 bool NextIsOp = NextToken.isOneOf(K1: tok::amp, K2: tok::star);
1199 if ((NextToken.is(K: tok::identifier) ||
1200 (NextIsOp &&
1201 FirstDecl->getUnderlyingDecl()->isFunctionOrFunctionTemplate())) &&
1202 isTagTypeWithMissingTag(SemaRef&: *this, Result, S, SS, Name, NameLoc)) {
1203 TypeDecl *Type = Result.getAsSingle<TypeDecl>();
1204 DiagnoseUseOfDecl(D: Type, Locs: NameLoc);
1205 return BuildTypeFor(Type, *Result.begin());
1206 }
1207
1208 // If we already know which single declaration is referenced, just annotate
1209 // that declaration directly. Defer resolving even non-overloaded class
1210 // member accesses, as we need to defer certain access checks until we know
1211 // the context.
1212 bool ADL = UseArgumentDependentLookup(SS, R: Result, HasTrailingLParen: NextToken.is(K: tok::l_paren));
1213 if (Result.isSingleResult() && !ADL &&
1214 (!FirstDecl->isCXXClassMember() || isa<EnumConstantDecl>(Val: FirstDecl)))
1215 return NameClassification::NonType(D: Result.getRepresentativeDecl());
1216
1217 // Otherwise, this is an overload set that we will need to resolve later.
1218 Result.suppressDiagnostics();
1219 return NameClassification::OverloadSet(E: UnresolvedLookupExpr::Create(
1220 Context, NamingClass: Result.getNamingClass(), QualifierLoc: SS.getWithLocInContext(Context),
1221 NameInfo: Result.getLookupNameInfo(), RequiresADL: ADL, Begin: Result.begin(), End: Result.end(),
1222 /*KnownDependent=*/false, /*KnownInstantiationDependent=*/false));
1223}
1224
1225ExprResult
1226Sema::ActOnNameClassifiedAsUndeclaredNonType(IdentifierInfo *Name,
1227 SourceLocation NameLoc) {
1228 assert(getLangOpts().CPlusPlus && "ADL-only call in C?");
1229 CXXScopeSpec SS;
1230 LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
1231 return BuildDeclarationNameExpr(SS, R&: Result, /*ADL=*/NeedsADL: true);
1232}
1233
1234ExprResult
1235Sema::ActOnNameClassifiedAsDependentNonType(const CXXScopeSpec &SS,
1236 IdentifierInfo *Name,
1237 SourceLocation NameLoc,
1238 bool IsAddressOfOperand) {
1239 DeclarationNameInfo NameInfo(Name, NameLoc);
1240 return ActOnDependentIdExpression(SS, /*TemplateKWLoc=*/SourceLocation(),
1241 NameInfo, isAddressOfOperand: IsAddressOfOperand,
1242 /*TemplateArgs=*/nullptr);
1243}
1244
1245ExprResult Sema::ActOnNameClassifiedAsNonType(Scope *S, const CXXScopeSpec &SS,
1246 NamedDecl *Found,
1247 SourceLocation NameLoc,
1248 const Token &NextToken) {
1249 if (getCurMethodDecl() && SS.isEmpty())
1250 if (auto *Ivar = dyn_cast<ObjCIvarDecl>(Val: Found->getUnderlyingDecl()))
1251 return ObjC().BuildIvarRefExpr(S, Loc: NameLoc, IV: Ivar);
1252
1253 // Reconstruct the lookup result.
1254 LookupResult Result(*this, Found->getDeclName(), NameLoc, LookupOrdinaryName);
1255 Result.addDecl(D: Found);
1256 Result.resolveKind();
1257
1258 bool ADL = UseArgumentDependentLookup(SS, R: Result, HasTrailingLParen: NextToken.is(K: tok::l_paren));
1259 return BuildDeclarationNameExpr(SS, R&: Result, NeedsADL: ADL, /*AcceptInvalidDecl=*/true);
1260}
1261
1262ExprResult Sema::ActOnNameClassifiedAsOverloadSet(Scope *S, Expr *E) {
1263 // For an implicit class member access, transform the result into a member
1264 // access expression if necessary.
1265 auto *ULE = cast<UnresolvedLookupExpr>(Val: E);
1266 if ((*ULE->decls_begin())->isCXXClassMember()) {
1267 CXXScopeSpec SS;
1268 SS.Adopt(Other: ULE->getQualifierLoc());
1269
1270 // Reconstruct the lookup result.
1271 LookupResult Result(*this, ULE->getName(), ULE->getNameLoc(),
1272 LookupOrdinaryName);
1273 Result.setNamingClass(ULE->getNamingClass());
1274 for (auto I = ULE->decls_begin(), E = ULE->decls_end(); I != E; ++I)
1275 Result.addDecl(D: *I, AS: I.getAccess());
1276 Result.resolveKind();
1277 return BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc: SourceLocation(), R&: Result,
1278 TemplateArgs: nullptr, S);
1279 }
1280
1281 // Otherwise, this is already in the form we needed, and no further checks
1282 // are necessary.
1283 return ULE;
1284}
1285
1286Sema::TemplateNameKindForDiagnostics
1287Sema::getTemplateNameKindForDiagnostics(TemplateName Name) {
1288 auto *TD = Name.getAsTemplateDecl();
1289 if (!TD)
1290 return TemplateNameKindForDiagnostics::DependentTemplate;
1291 if (isa<ClassTemplateDecl>(Val: TD))
1292 return TemplateNameKindForDiagnostics::ClassTemplate;
1293 if (isa<FunctionTemplateDecl>(Val: TD))
1294 return TemplateNameKindForDiagnostics::FunctionTemplate;
1295 if (isa<VarTemplateDecl>(Val: TD))
1296 return TemplateNameKindForDiagnostics::VarTemplate;
1297 if (isa<TypeAliasTemplateDecl>(Val: TD))
1298 return TemplateNameKindForDiagnostics::AliasTemplate;
1299 if (isa<TemplateTemplateParmDecl>(Val: TD))
1300 return TemplateNameKindForDiagnostics::TemplateTemplateParam;
1301 if (isa<ConceptDecl>(Val: TD))
1302 return TemplateNameKindForDiagnostics::Concept;
1303 return TemplateNameKindForDiagnostics::DependentTemplate;
1304}
1305
1306void Sema::PushDeclContext(Scope *S, DeclContext *DC) {
1307 assert(DC->getLexicalParent() == CurContext &&
1308 "The next DeclContext should be lexically contained in the current one.");
1309 CurContext = DC;
1310 S->setEntity(DC);
1311}
1312
1313void Sema::PopDeclContext() {
1314 assert(CurContext && "DeclContext imbalance!");
1315
1316 CurContext = CurContext->getLexicalParent();
1317 assert(CurContext && "Popped translation unit!");
1318}
1319
1320Sema::SkippedDefinitionContext Sema::ActOnTagStartSkippedDefinition(Scope *S,
1321 Decl *D) {
1322 // Unlike PushDeclContext, the context to which we return is not necessarily
1323 // the containing DC of TD, because the new context will be some pre-existing
1324 // TagDecl definition instead of a fresh one.
1325 auto Result = static_cast<SkippedDefinitionContext>(CurContext);
1326 CurContext = cast<TagDecl>(Val: D)->getDefinition();
1327 assert(CurContext && "skipping definition of undefined tag");
1328 // Start lookups from the parent of the current context; we don't want to look
1329 // into the pre-existing complete definition.
1330 S->setEntity(CurContext->getLookupParent());
1331 return Result;
1332}
1333
1334void Sema::ActOnTagFinishSkippedDefinition(SkippedDefinitionContext Context) {
1335 CurContext = static_cast<decltype(CurContext)>(Context);
1336}
1337
1338void Sema::EnterDeclaratorContext(Scope *S, DeclContext *DC) {
1339 // C++0x [basic.lookup.unqual]p13:
1340 // A name used in the definition of a static data member of class
1341 // X (after the qualified-id of the static member) is looked up as
1342 // if the name was used in a member function of X.
1343 // C++0x [basic.lookup.unqual]p14:
1344 // If a variable member of a namespace is defined outside of the
1345 // scope of its namespace then any name used in the definition of
1346 // the variable member (after the declarator-id) is looked up as
1347 // if the definition of the variable member occurred in its
1348 // namespace.
1349 // Both of these imply that we should push a scope whose context
1350 // is the semantic context of the declaration. We can't use
1351 // PushDeclContext here because that context is not necessarily
1352 // lexically contained in the current context. Fortunately,
1353 // the containing scope should have the appropriate information.
1354
1355 assert(!S->getEntity() && "scope already has entity");
1356
1357#ifndef NDEBUG
1358 Scope *Ancestor = S->getParent();
1359 while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent();
1360 assert(Ancestor->getEntity() == CurContext && "ancestor context mismatch");
1361#endif
1362
1363 CurContext = DC;
1364 S->setEntity(DC);
1365
1366 if (S->getParent()->isTemplateParamScope()) {
1367 // Also set the corresponding entities for all immediately-enclosing
1368 // template parameter scopes.
1369 EnterTemplatedContext(S: S->getParent(), DC);
1370 }
1371}
1372
1373void Sema::ExitDeclaratorContext(Scope *S) {
1374 assert(S->getEntity() == CurContext && "Context imbalance!");
1375
1376 // Switch back to the lexical context. The safety of this is
1377 // enforced by an assert in EnterDeclaratorContext.
1378 Scope *Ancestor = S->getParent();
1379 while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent();
1380 CurContext = Ancestor->getEntity();
1381
1382 // We don't need to do anything with the scope, which is going to
1383 // disappear.
1384}
1385
1386void Sema::EnterTemplatedContext(Scope *S, DeclContext *DC) {
1387 assert(S->isTemplateParamScope() &&
1388 "expected to be initializing a template parameter scope");
1389
1390 // C++20 [temp.local]p7:
1391 // In the definition of a member of a class template that appears outside
1392 // of the class template definition, the name of a member of the class
1393 // template hides the name of a template-parameter of any enclosing class
1394 // templates (but not a template-parameter of the member if the member is a
1395 // class or function template).
1396 // C++20 [temp.local]p9:
1397 // In the definition of a class template or in the definition of a member
1398 // of such a template that appears outside of the template definition, for
1399 // each non-dependent base class (13.8.2.1), if the name of the base class
1400 // or the name of a member of the base class is the same as the name of a
1401 // template-parameter, the base class name or member name hides the
1402 // template-parameter name (6.4.10).
1403 //
1404 // This means that a template parameter scope should be searched immediately
1405 // after searching the DeclContext for which it is a template parameter
1406 // scope. For example, for
1407 // template<typename T> template<typename U> template<typename V>
1408 // void N::A<T>::B<U>::f(...)
1409 // we search V then B<U> (and base classes) then U then A<T> (and base
1410 // classes) then T then N then ::.
1411 unsigned ScopeDepth = getTemplateDepth(S);
1412 for (; S && S->isTemplateParamScope(); S = S->getParent(), --ScopeDepth) {
1413 DeclContext *SearchDCAfterScope = DC;
1414 for (; DC; DC = DC->getLookupParent()) {
1415 if (const TemplateParameterList *TPL =
1416 cast<Decl>(Val: DC)->getDescribedTemplateParams()) {
1417 unsigned DCDepth = TPL->getDepth() + 1;
1418 if (DCDepth > ScopeDepth)
1419 continue;
1420 if (ScopeDepth == DCDepth)
1421 SearchDCAfterScope = DC = DC->getLookupParent();
1422 break;
1423 }
1424 }
1425 S->setLookupEntity(SearchDCAfterScope);
1426 }
1427}
1428
1429void Sema::ActOnReenterFunctionContext(Scope* S, Decl *D) {
1430 // We assume that the caller has already called
1431 // ActOnReenterTemplateScope so getTemplatedDecl() works.
1432 FunctionDecl *FD = D->getAsFunction();
1433 if (!FD)
1434 return;
1435
1436 // Same implementation as PushDeclContext, but enters the context
1437 // from the lexical parent, rather than the top-level class.
1438 assert(CurContext == FD->getLexicalParent() &&
1439 "The next DeclContext should be lexically contained in the current one.");
1440 CurContext = FD;
1441 S->setEntity(CurContext);
1442
1443 for (unsigned P = 0, NumParams = FD->getNumParams(); P < NumParams; ++P) {
1444 ParmVarDecl *Param = FD->getParamDecl(i: P);
1445 // If the parameter has an identifier, then add it to the scope
1446 if (Param->getIdentifier()) {
1447 S->AddDecl(D: Param);
1448 IdResolver.AddDecl(D: Param);
1449 }
1450 }
1451}
1452
1453void Sema::ActOnExitFunctionContext() {
1454 // Same implementation as PopDeclContext, but returns to the lexical parent,
1455 // rather than the top-level class.
1456 assert(CurContext && "DeclContext imbalance!");
1457 CurContext = CurContext->getLexicalParent();
1458 assert(CurContext && "Popped translation unit!");
1459}
1460
1461/// Determine whether overloading is allowed for a new function
1462/// declaration considering prior declarations of the same name.
1463///
1464/// This routine determines whether overloading is possible, not
1465/// whether a new declaration actually overloads a previous one.
1466/// It will return true in C++ (where overloads are always permitted)
1467/// or, as a C extension, when either the new declaration or a
1468/// previous one is declared with the 'overloadable' attribute.
1469static bool AllowOverloadingOfFunction(const LookupResult &Previous,
1470 ASTContext &Context,
1471 const FunctionDecl *New) {
1472 if (Context.getLangOpts().CPlusPlus || New->hasAttr<OverloadableAttr>())
1473 return true;
1474
1475 // Multiversion function declarations are not overloads in the
1476 // usual sense of that term, but lookup will report that an
1477 // overload set was found if more than one multiversion function
1478 // declaration is present for the same name. It is therefore
1479 // inadequate to assume that some prior declaration(s) had
1480 // the overloadable attribute; checking is required. Since one
1481 // declaration is permitted to omit the attribute, it is necessary
1482 // to check at least two; hence the 'any_of' check below. Note that
1483 // the overloadable attribute is implicitly added to declarations
1484 // that were required to have it but did not.
1485 if (Previous.getResultKind() == LookupResult::FoundOverloaded) {
1486 return llvm::any_of(Range: Previous, P: [](const NamedDecl *ND) {
1487 return ND->hasAttr<OverloadableAttr>();
1488 });
1489 } else if (Previous.getResultKind() == LookupResult::Found)
1490 return Previous.getFoundDecl()->hasAttr<OverloadableAttr>();
1491
1492 return false;
1493}
1494
1495void Sema::PushOnScopeChains(NamedDecl *D, Scope *S, bool AddToContext) {
1496 // Move up the scope chain until we find the nearest enclosing
1497 // non-transparent context. The declaration will be introduced into this
1498 // scope.
1499 while (S->getEntity() && S->getEntity()->isTransparentContext())
1500 S = S->getParent();
1501
1502 // Add scoped declarations into their context, so that they can be
1503 // found later. Declarations without a context won't be inserted
1504 // into any context.
1505 if (AddToContext)
1506 CurContext->addDecl(D);
1507
1508 // Out-of-line definitions shouldn't be pushed into scope in C++, unless they
1509 // are function-local declarations.
1510 if (getLangOpts().CPlusPlus && D->isOutOfLine() && !S->getFnParent())
1511 return;
1512
1513 // Template instantiations should also not be pushed into scope.
1514 if (isa<FunctionDecl>(Val: D) &&
1515 cast<FunctionDecl>(Val: D)->isFunctionTemplateSpecialization())
1516 return;
1517
1518 if (isa<UsingEnumDecl>(Val: D) && D->getDeclName().isEmpty()) {
1519 S->AddDecl(D);
1520 return;
1521 }
1522 // If this replaces anything in the current scope,
1523 IdentifierResolver::iterator I = IdResolver.begin(Name: D->getDeclName()),
1524 IEnd = IdResolver.end();
1525 for (; I != IEnd; ++I) {
1526 if (S->isDeclScope(D: *I) && D->declarationReplaces(OldD: *I)) {
1527 S->RemoveDecl(D: *I);
1528 IdResolver.RemoveDecl(D: *I);
1529
1530 // Should only need to replace one decl.
1531 break;
1532 }
1533 }
1534
1535 S->AddDecl(D);
1536
1537 if (isa<LabelDecl>(Val: D) && !cast<LabelDecl>(Val: D)->isGnuLocal()) {
1538 // Implicitly-generated labels may end up getting generated in an order that
1539 // isn't strictly lexical, which breaks name lookup. Be careful to insert
1540 // the label at the appropriate place in the identifier chain.
1541 for (I = IdResolver.begin(Name: D->getDeclName()); I != IEnd; ++I) {
1542 DeclContext *IDC = (*I)->getLexicalDeclContext()->getRedeclContext();
1543 if (IDC == CurContext) {
1544 if (!S->isDeclScope(D: *I))
1545 continue;
1546 } else if (IDC->Encloses(DC: CurContext))
1547 break;
1548 }
1549
1550 IdResolver.InsertDeclAfter(Pos: I, D);
1551 } else {
1552 IdResolver.AddDecl(D);
1553 }
1554 warnOnReservedIdentifier(D);
1555}
1556
1557bool Sema::isDeclInScope(NamedDecl *D, DeclContext *Ctx, Scope *S,
1558 bool AllowInlineNamespace) const {
1559 return IdResolver.isDeclInScope(D, Ctx, S, AllowInlineNamespace);
1560}
1561
1562Scope *Sema::getScopeForDeclContext(Scope *S, DeclContext *DC) {
1563 DeclContext *TargetDC = DC->getPrimaryContext();
1564 do {
1565 if (DeclContext *ScopeDC = S->getEntity())
1566 if (ScopeDC->getPrimaryContext() == TargetDC)
1567 return S;
1568 } while ((S = S->getParent()));
1569
1570 return nullptr;
1571}
1572
1573static bool isOutOfScopePreviousDeclaration(NamedDecl *,
1574 DeclContext*,
1575 ASTContext&);
1576
1577void Sema::FilterLookupForScope(LookupResult &R, DeclContext *Ctx, Scope *S,
1578 bool ConsiderLinkage,
1579 bool AllowInlineNamespace) {
1580 LookupResult::Filter F = R.makeFilter();
1581 while (F.hasNext()) {
1582 NamedDecl *D = F.next();
1583
1584 if (isDeclInScope(D, Ctx, S, AllowInlineNamespace))
1585 continue;
1586
1587 if (ConsiderLinkage && isOutOfScopePreviousDeclaration(D, Ctx, Context))
1588 continue;
1589
1590 F.erase();
1591 }
1592
1593 F.done();
1594}
1595
1596bool Sema::CheckRedeclarationModuleOwnership(NamedDecl *New, NamedDecl *Old) {
1597 // [module.interface]p7:
1598 // A declaration is attached to a module as follows:
1599 // - If the declaration is a non-dependent friend declaration that nominates a
1600 // function with a declarator-id that is a qualified-id or template-id or that
1601 // nominates a class other than with an elaborated-type-specifier with neither
1602 // a nested-name-specifier nor a simple-template-id, it is attached to the
1603 // module to which the friend is attached ([basic.link]).
1604 if (New->getFriendObjectKind() &&
1605 Old->getOwningModuleForLinkage() != New->getOwningModuleForLinkage()) {
1606 New->setLocalOwningModule(Old->getOwningModule());
1607 makeMergedDefinitionVisible(ND: New);
1608 return false;
1609 }
1610
1611 Module *NewM = New->getOwningModule();
1612 Module *OldM = Old->getOwningModule();
1613
1614 if (NewM && NewM->isPrivateModule())
1615 NewM = NewM->Parent;
1616 if (OldM && OldM->isPrivateModule())
1617 OldM = OldM->Parent;
1618
1619 if (NewM == OldM)
1620 return false;
1621
1622 if (NewM && OldM) {
1623 // A module implementation unit has visibility of the decls in its
1624 // implicitly imported interface.
1625 if (NewM->isModuleImplementation() && OldM == ThePrimaryInterface)
1626 return false;
1627
1628 // Partitions are part of the module, but a partition could import another
1629 // module, so verify that the PMIs agree.
1630 if ((NewM->isModulePartition() || OldM->isModulePartition()) &&
1631 getASTContext().isInSameModule(M1: NewM, M2: OldM))
1632 return false;
1633 }
1634
1635 bool NewIsModuleInterface = NewM && NewM->isNamedModule();
1636 bool OldIsModuleInterface = OldM && OldM->isNamedModule();
1637 if (NewIsModuleInterface || OldIsModuleInterface) {
1638 // C++ Modules TS [basic.def.odr] 6.2/6.7 [sic]:
1639 // if a declaration of D [...] appears in the purview of a module, all
1640 // other such declarations shall appear in the purview of the same module
1641 Diag(Loc: New->getLocation(), DiagID: diag::err_mismatched_owning_module)
1642 << New
1643 << NewIsModuleInterface
1644 << (NewIsModuleInterface ? NewM->getFullModuleName() : "")
1645 << OldIsModuleInterface
1646 << (OldIsModuleInterface ? OldM->getFullModuleName() : "");
1647 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_declaration);
1648 New->setInvalidDecl();
1649 return true;
1650 }
1651
1652 return false;
1653}
1654
1655bool Sema::CheckRedeclarationExported(NamedDecl *New, NamedDecl *Old) {
1656 // [module.interface]p1:
1657 // An export-declaration shall inhabit a namespace scope.
1658 //
1659 // So it is meaningless to talk about redeclaration which is not at namespace
1660 // scope.
1661 if (!New->getLexicalDeclContext()
1662 ->getNonTransparentContext()
1663 ->isFileContext() ||
1664 !Old->getLexicalDeclContext()
1665 ->getNonTransparentContext()
1666 ->isFileContext())
1667 return false;
1668
1669 bool IsNewExported = New->isInExportDeclContext();
1670 bool IsOldExported = Old->isInExportDeclContext();
1671
1672 // It should be irrevelant if both of them are not exported.
1673 if (!IsNewExported && !IsOldExported)
1674 return false;
1675
1676 if (IsOldExported)
1677 return false;
1678
1679 // If the Old declaration are not attached to named modules
1680 // and the New declaration are attached to global module.
1681 // It should be fine to allow the export since it doesn't change
1682 // the linkage of declarations. See
1683 // https://github.com/llvm/llvm-project/issues/98583 for details.
1684 if (!Old->isInNamedModule() && New->getOwningModule() &&
1685 New->getOwningModule()->isImplicitGlobalModule())
1686 return false;
1687
1688 assert(IsNewExported);
1689
1690 auto Lk = Old->getFormalLinkage();
1691 int S = 0;
1692 if (Lk == Linkage::Internal)
1693 S = 1;
1694 else if (Lk == Linkage::Module)
1695 S = 2;
1696 Diag(Loc: New->getLocation(), DiagID: diag::err_redeclaration_non_exported) << New << S;
1697 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_declaration);
1698 return true;
1699}
1700
1701bool Sema::CheckRedeclarationInModule(NamedDecl *New, NamedDecl *Old) {
1702 if (CheckRedeclarationModuleOwnership(New, Old))
1703 return true;
1704
1705 if (CheckRedeclarationExported(New, Old))
1706 return true;
1707
1708 return false;
1709}
1710
1711bool Sema::IsRedefinitionInModule(const NamedDecl *New,
1712 const NamedDecl *Old) const {
1713 assert(getASTContext().isSameEntity(New, Old) &&
1714 "New and Old are not the same definition, we should diagnostic it "
1715 "immediately instead of checking it.");
1716 assert(const_cast<Sema *>(this)->isReachable(New) &&
1717 const_cast<Sema *>(this)->isReachable(Old) &&
1718 "We shouldn't see unreachable definitions here.");
1719
1720 Module *NewM = New->getOwningModule();
1721 Module *OldM = Old->getOwningModule();
1722
1723 // We only checks for named modules here. The header like modules is skipped.
1724 // FIXME: This is not right if we import the header like modules in the module
1725 // purview.
1726 //
1727 // For example, assuming "header.h" provides definition for `D`.
1728 // ```C++
1729 // //--- M.cppm
1730 // export module M;
1731 // import "header.h"; // or #include "header.h" but import it by clang modules
1732 // actually.
1733 //
1734 // //--- Use.cpp
1735 // import M;
1736 // import "header.h"; // or uses clang modules.
1737 // ```
1738 //
1739 // In this case, `D` has multiple definitions in multiple TU (M.cppm and
1740 // Use.cpp) and `D` is attached to a named module `M`. The compiler should
1741 // reject it. But the current implementation couldn't detect the case since we
1742 // don't record the information about the importee modules.
1743 //
1744 // But this might not be painful in practice. Since the design of C++20 Named
1745 // Modules suggests us to use headers in global module fragment instead of
1746 // module purview.
1747 if (NewM && NewM->isHeaderLikeModule())
1748 NewM = nullptr;
1749 if (OldM && OldM->isHeaderLikeModule())
1750 OldM = nullptr;
1751
1752 if (!NewM && !OldM)
1753 return true;
1754
1755 // [basic.def.odr]p14.3
1756 // Each such definition shall not be attached to a named module
1757 // ([module.unit]).
1758 if ((NewM && NewM->isNamedModule()) || (OldM && OldM->isNamedModule()))
1759 return true;
1760
1761 // Then New and Old lives in the same TU if their share one same module unit.
1762 if (NewM)
1763 NewM = NewM->getTopLevelModule();
1764 if (OldM)
1765 OldM = OldM->getTopLevelModule();
1766 return OldM == NewM;
1767}
1768
1769static bool isUsingDeclNotAtClassScope(NamedDecl *D) {
1770 if (D->getDeclContext()->isFileContext())
1771 return false;
1772
1773 return isa<UsingShadowDecl>(Val: D) ||
1774 isa<UnresolvedUsingTypenameDecl>(Val: D) ||
1775 isa<UnresolvedUsingValueDecl>(Val: D);
1776}
1777
1778/// Removes using shadow declarations not at class scope from the lookup
1779/// results.
1780static void RemoveUsingDecls(LookupResult &R) {
1781 LookupResult::Filter F = R.makeFilter();
1782 while (F.hasNext())
1783 if (isUsingDeclNotAtClassScope(D: F.next()))
1784 F.erase();
1785
1786 F.done();
1787}
1788
1789/// Check for this common pattern:
1790/// @code
1791/// class S {
1792/// S(const S&); // DO NOT IMPLEMENT
1793/// void operator=(const S&); // DO NOT IMPLEMENT
1794/// };
1795/// @endcode
1796static bool IsDisallowedCopyOrAssign(const CXXMethodDecl *D) {
1797 // FIXME: Should check for private access too but access is set after we get
1798 // the decl here.
1799 if (D->doesThisDeclarationHaveABody())
1800 return false;
1801
1802 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Val: D))
1803 return CD->isCopyConstructor();
1804 return D->isCopyAssignmentOperator();
1805}
1806
1807bool Sema::mightHaveNonExternalLinkage(const DeclaratorDecl *D) {
1808 const DeclContext *DC = D->getDeclContext();
1809 while (!DC->isTranslationUnit()) {
1810 if (const RecordDecl *RD = dyn_cast<RecordDecl>(Val: DC)){
1811 if (!RD->hasNameForLinkage())
1812 return true;
1813 }
1814 DC = DC->getParent();
1815 }
1816
1817 return !D->isExternallyVisible();
1818}
1819
1820// FIXME: This needs to be refactored; some other isInMainFile users want
1821// these semantics.
1822static bool isMainFileLoc(const Sema &S, SourceLocation Loc) {
1823 if (S.TUKind != TU_Complete || S.getLangOpts().IsHeaderFile)
1824 return false;
1825 return S.SourceMgr.isInMainFile(Loc);
1826}
1827
1828bool Sema::ShouldWarnIfUnusedFileScopedDecl(const DeclaratorDecl *D) const {
1829 assert(D);
1830
1831 if (D->isInvalidDecl() || D->isUsed() || D->hasAttr<UnusedAttr>())
1832 return false;
1833
1834 // Ignore all entities declared within templates, and out-of-line definitions
1835 // of members of class templates.
1836 if (D->getDeclContext()->isDependentContext() ||
1837 D->getLexicalDeclContext()->isDependentContext())
1838 return false;
1839
1840 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: D)) {
1841 if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
1842 return false;
1843 // A non-out-of-line declaration of a member specialization was implicitly
1844 // instantiated; it's the out-of-line declaration that we're interested in.
1845 if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
1846 FD->getMemberSpecializationInfo() && !FD->isOutOfLine())
1847 return false;
1848
1849 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Val: FD)) {
1850 if (MD->isVirtual() || IsDisallowedCopyOrAssign(D: MD))
1851 return false;
1852 } else {
1853 // 'static inline' functions are defined in headers; don't warn.
1854 if (FD->isInlined() && !isMainFileLoc(S: *this, Loc: FD->getLocation()))
1855 return false;
1856 }
1857
1858 if (FD->doesThisDeclarationHaveABody() &&
1859 Context.DeclMustBeEmitted(D: FD))
1860 return false;
1861 } else if (const VarDecl *VD = dyn_cast<VarDecl>(Val: D)) {
1862 // Constants and utility variables are defined in headers with internal
1863 // linkage; don't warn. (Unlike functions, there isn't a convenient marker
1864 // like "inline".)
1865 if (!isMainFileLoc(S: *this, Loc: VD->getLocation()))
1866 return false;
1867
1868 if (Context.DeclMustBeEmitted(D: VD))
1869 return false;
1870
1871 if (VD->isStaticDataMember() &&
1872 VD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
1873 return false;
1874 if (VD->isStaticDataMember() &&
1875 VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
1876 VD->getMemberSpecializationInfo() && !VD->isOutOfLine())
1877 return false;
1878
1879 if (VD->isInline() && !isMainFileLoc(S: *this, Loc: VD->getLocation()))
1880 return false;
1881 } else {
1882 return false;
1883 }
1884
1885 // Only warn for unused decls internal to the translation unit.
1886 // FIXME: This seems like a bogus check; it suppresses -Wunused-function
1887 // for inline functions defined in the main source file, for instance.
1888 return mightHaveNonExternalLinkage(D);
1889}
1890
1891void Sema::MarkUnusedFileScopedDecl(const DeclaratorDecl *D) {
1892 if (!D)
1893 return;
1894
1895 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: D)) {
1896 const FunctionDecl *First = FD->getFirstDecl();
1897 if (FD != First && ShouldWarnIfUnusedFileScopedDecl(D: First))
1898 return; // First should already be in the vector.
1899 }
1900
1901 if (const VarDecl *VD = dyn_cast<VarDecl>(Val: D)) {
1902 const VarDecl *First = VD->getFirstDecl();
1903 if (VD != First && ShouldWarnIfUnusedFileScopedDecl(D: First))
1904 return; // First should already be in the vector.
1905 }
1906
1907 if (ShouldWarnIfUnusedFileScopedDecl(D))
1908 UnusedFileScopedDecls.push_back(LocalValue: D);
1909}
1910
1911static bool ShouldDiagnoseUnusedDecl(const LangOptions &LangOpts,
1912 const NamedDecl *D) {
1913 if (D->isInvalidDecl())
1914 return false;
1915
1916 if (const auto *DD = dyn_cast<DecompositionDecl>(Val: D)) {
1917 // For a decomposition declaration, warn if none of the bindings are
1918 // referenced, instead of if the variable itself is referenced (which
1919 // it is, by the bindings' expressions).
1920 bool IsAllPlaceholders = true;
1921 for (const auto *BD : DD->bindings()) {
1922 if (BD->isReferenced() || BD->hasAttr<UnusedAttr>())
1923 return false;
1924 IsAllPlaceholders = IsAllPlaceholders && BD->isPlaceholderVar(LangOpts);
1925 }
1926 if (IsAllPlaceholders)
1927 return false;
1928 } else if (!D->getDeclName()) {
1929 return false;
1930 } else if (D->isReferenced() || D->isUsed()) {
1931 return false;
1932 }
1933
1934 if (D->isPlaceholderVar(LangOpts))
1935 return false;
1936
1937 if (D->hasAttr<UnusedAttr>() || D->hasAttr<ObjCPreciseLifetimeAttr>() ||
1938 D->hasAttr<CleanupAttr>())
1939 return false;
1940
1941 if (isa<LabelDecl>(Val: D))
1942 return true;
1943
1944 // Except for labels, we only care about unused decls that are local to
1945 // functions.
1946 bool WithinFunction = D->getDeclContext()->isFunctionOrMethod();
1947 if (const auto *R = dyn_cast<CXXRecordDecl>(Val: D->getDeclContext()))
1948 // For dependent types, the diagnostic is deferred.
1949 WithinFunction =
1950 WithinFunction || (R->isLocalClass() && !R->isDependentType());
1951 if (!WithinFunction)
1952 return false;
1953
1954 if (isa<TypedefNameDecl>(Val: D))
1955 return true;
1956
1957 // White-list anything that isn't a local variable.
1958 if (!isa<VarDecl>(Val: D) || isa<ParmVarDecl>(Val: D) || isa<ImplicitParamDecl>(Val: D))
1959 return false;
1960
1961 // Types of valid local variables should be complete, so this should succeed.
1962 if (const VarDecl *VD = dyn_cast<VarDecl>(Val: D)) {
1963
1964 const Expr *Init = VD->getInit();
1965 if (const auto *Cleanups = dyn_cast_if_present<ExprWithCleanups>(Val: Init))
1966 Init = Cleanups->getSubExpr();
1967
1968 const auto *Ty = VD->getType().getTypePtr();
1969
1970 // Only look at the outermost level of typedef.
1971 if (const TypedefType *TT = Ty->getAs<TypedefType>()) {
1972 // Allow anything marked with __attribute__((unused)).
1973 if (TT->getDecl()->hasAttr<UnusedAttr>())
1974 return false;
1975 }
1976
1977 // Warn for reference variables whose initializtion performs lifetime
1978 // extension.
1979 if (const auto *MTE = dyn_cast_if_present<MaterializeTemporaryExpr>(Val: Init);
1980 MTE && MTE->getExtendingDecl()) {
1981 Ty = VD->getType().getNonReferenceType().getTypePtr();
1982 Init = MTE->getSubExpr()->IgnoreImplicitAsWritten();
1983 }
1984
1985 // If we failed to complete the type for some reason, or if the type is
1986 // dependent, don't diagnose the variable.
1987 if (Ty->isIncompleteType() || Ty->isDependentType())
1988 return false;
1989
1990 // Look at the element type to ensure that the warning behaviour is
1991 // consistent for both scalars and arrays.
1992 Ty = Ty->getBaseElementTypeUnsafe();
1993
1994 if (const TagType *TT = Ty->getAs<TagType>()) {
1995 const TagDecl *Tag = TT->getDecl();
1996 if (Tag->hasAttr<UnusedAttr>())
1997 return false;
1998
1999 if (const auto *RD = dyn_cast<CXXRecordDecl>(Val: Tag)) {
2000 if (!RD->hasTrivialDestructor() && !RD->hasAttr<WarnUnusedAttr>())
2001 return false;
2002
2003 if (Init) {
2004 const auto *Construct =
2005 dyn_cast<CXXConstructExpr>(Val: Init->IgnoreImpCasts());
2006 if (Construct && !Construct->isElidable()) {
2007 const CXXConstructorDecl *CD = Construct->getConstructor();
2008 if (!CD->isTrivial() && !RD->hasAttr<WarnUnusedAttr>() &&
2009 (VD->getInit()->isValueDependent() || !VD->evaluateValue()))
2010 return false;
2011 }
2012
2013 // Suppress the warning if we don't know how this is constructed, and
2014 // it could possibly be non-trivial constructor.
2015 if (Init->isTypeDependent()) {
2016 for (const CXXConstructorDecl *Ctor : RD->ctors())
2017 if (!Ctor->isTrivial())
2018 return false;
2019 }
2020
2021 // Suppress the warning if the constructor is unresolved because
2022 // its arguments are dependent.
2023 if (isa<CXXUnresolvedConstructExpr>(Val: Init))
2024 return false;
2025 }
2026 }
2027 }
2028
2029 // TODO: __attribute__((unused)) templates?
2030 }
2031
2032 return true;
2033}
2034
2035static void GenerateFixForUnusedDecl(const NamedDecl *D, ASTContext &Ctx,
2036 FixItHint &Hint) {
2037 if (isa<LabelDecl>(Val: D)) {
2038 SourceLocation AfterColon = Lexer::findLocationAfterToken(
2039 loc: D->getEndLoc(), TKind: tok::colon, SM: Ctx.getSourceManager(), LangOpts: Ctx.getLangOpts(),
2040 /*SkipTrailingWhitespaceAndNewline=*/SkipTrailingWhitespaceAndNewLine: false);
2041 if (AfterColon.isInvalid())
2042 return;
2043 Hint = FixItHint::CreateRemoval(
2044 RemoveRange: CharSourceRange::getCharRange(B: D->getBeginLoc(), E: AfterColon));
2045 }
2046}
2047
2048void Sema::DiagnoseUnusedNestedTypedefs(const RecordDecl *D) {
2049 DiagnoseUnusedNestedTypedefs(
2050 D, DiagReceiver: [this](SourceLocation Loc, PartialDiagnostic PD) { Diag(Loc, PD); });
2051}
2052
2053void Sema::DiagnoseUnusedNestedTypedefs(const RecordDecl *D,
2054 DiagReceiverTy DiagReceiver) {
2055 if (D->getTypeForDecl()->isDependentType())
2056 return;
2057
2058 for (auto *TmpD : D->decls()) {
2059 if (const auto *T = dyn_cast<TypedefNameDecl>(Val: TmpD))
2060 DiagnoseUnusedDecl(ND: T, DiagReceiver);
2061 else if(const auto *R = dyn_cast<RecordDecl>(Val: TmpD))
2062 DiagnoseUnusedNestedTypedefs(D: R, DiagReceiver);
2063 }
2064}
2065
2066void Sema::DiagnoseUnusedDecl(const NamedDecl *D) {
2067 DiagnoseUnusedDecl(
2068 ND: D, DiagReceiver: [this](SourceLocation Loc, PartialDiagnostic PD) { Diag(Loc, PD); });
2069}
2070
2071void Sema::DiagnoseUnusedDecl(const NamedDecl *D, DiagReceiverTy DiagReceiver) {
2072 if (!ShouldDiagnoseUnusedDecl(LangOpts: getLangOpts(), D))
2073 return;
2074
2075 if (auto *TD = dyn_cast<TypedefNameDecl>(Val: D)) {
2076 // typedefs can be referenced later on, so the diagnostics are emitted
2077 // at end-of-translation-unit.
2078 UnusedLocalTypedefNameCandidates.insert(X: TD);
2079 return;
2080 }
2081
2082 FixItHint Hint;
2083 GenerateFixForUnusedDecl(D, Ctx&: Context, Hint);
2084
2085 unsigned DiagID;
2086 if (isa<VarDecl>(Val: D) && cast<VarDecl>(Val: D)->isExceptionVariable())
2087 DiagID = diag::warn_unused_exception_param;
2088 else if (isa<LabelDecl>(Val: D))
2089 DiagID = diag::warn_unused_label;
2090 else
2091 DiagID = diag::warn_unused_variable;
2092
2093 SourceLocation DiagLoc = D->getLocation();
2094 DiagReceiver(DiagLoc, PDiag(DiagID) << D << Hint << SourceRange(DiagLoc));
2095}
2096
2097void Sema::DiagnoseUnusedButSetDecl(const VarDecl *VD,
2098 DiagReceiverTy DiagReceiver) {
2099 // If it's not referenced, it can't be set. If it has the Cleanup attribute,
2100 // it's not really unused.
2101 if (!VD->isReferenced() || !VD->getDeclName() || VD->hasAttr<CleanupAttr>())
2102 return;
2103
2104 // In C++, `_` variables behave as if they were maybe_unused
2105 if (VD->hasAttr<UnusedAttr>() || VD->isPlaceholderVar(LangOpts: getLangOpts()))
2106 return;
2107
2108 const auto *Ty = VD->getType().getTypePtr()->getBaseElementTypeUnsafe();
2109
2110 if (Ty->isReferenceType() || Ty->isDependentType())
2111 return;
2112
2113 if (const TagType *TT = Ty->getAs<TagType>()) {
2114 const TagDecl *Tag = TT->getDecl();
2115 if (Tag->hasAttr<UnusedAttr>())
2116 return;
2117 // In C++, don't warn for record types that don't have WarnUnusedAttr, to
2118 // mimic gcc's behavior.
2119 if (const auto *RD = dyn_cast<CXXRecordDecl>(Val: Tag);
2120 RD && !RD->hasAttr<WarnUnusedAttr>())
2121 return;
2122 }
2123
2124 // Don't warn about __block Objective-C pointer variables, as they might
2125 // be assigned in the block but not used elsewhere for the purpose of lifetime
2126 // extension.
2127 if (VD->hasAttr<BlocksAttr>() && Ty->isObjCObjectPointerType())
2128 return;
2129
2130 // Don't warn about Objective-C pointer variables with precise lifetime
2131 // semantics; they can be used to ensure ARC releases the object at a known
2132 // time, which may mean assignment but no other references.
2133 if (VD->hasAttr<ObjCPreciseLifetimeAttr>() && Ty->isObjCObjectPointerType())
2134 return;
2135
2136 auto iter = RefsMinusAssignments.find(Val: VD);
2137 if (iter == RefsMinusAssignments.end())
2138 return;
2139
2140 assert(iter->getSecond() >= 0 &&
2141 "Found a negative number of references to a VarDecl");
2142 if (int RefCnt = iter->getSecond(); RefCnt > 0) {
2143 // Assume the given VarDecl is "used" if its ref count stored in
2144 // `RefMinusAssignments` is positive, with one exception.
2145 //
2146 // For a C++ variable whose decl (with initializer) entirely consist the
2147 // condition expression of a if/while/for construct,
2148 // Clang creates a DeclRefExpr for the condition expression rather than a
2149 // BinaryOperator of AssignmentOp. Thus, the C++ variable's ref
2150 // count stored in `RefMinusAssignment` equals 1 when the variable is never
2151 // used in the body of the if/while/for construct.
2152 bool UnusedCXXCondDecl = VD->isCXXCondDecl() && (RefCnt == 1);
2153 if (!UnusedCXXCondDecl)
2154 return;
2155 }
2156
2157 unsigned DiagID = isa<ParmVarDecl>(Val: VD) ? diag::warn_unused_but_set_parameter
2158 : diag::warn_unused_but_set_variable;
2159 DiagReceiver(VD->getLocation(), PDiag(DiagID) << VD);
2160}
2161
2162static void CheckPoppedLabel(LabelDecl *L, Sema &S,
2163 Sema::DiagReceiverTy DiagReceiver) {
2164 // Verify that we have no forward references left. If so, there was a goto
2165 // or address of a label taken, but no definition of it. Label fwd
2166 // definitions are indicated with a null substmt which is also not a resolved
2167 // MS inline assembly label name.
2168 bool Diagnose = false;
2169 if (L->isMSAsmLabel())
2170 Diagnose = !L->isResolvedMSAsmLabel();
2171 else
2172 Diagnose = L->getStmt() == nullptr;
2173 if (Diagnose)
2174 DiagReceiver(L->getLocation(), S.PDiag(DiagID: diag::err_undeclared_label_use)
2175 << L);
2176}
2177
2178void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) {
2179 S->applyNRVO();
2180
2181 if (S->decl_empty()) return;
2182 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) &&
2183 "Scope shouldn't contain decls!");
2184
2185 /// We visit the decls in non-deterministic order, but we want diagnostics
2186 /// emitted in deterministic order. Collect any diagnostic that may be emitted
2187 /// and sort the diagnostics before emitting them, after we visited all decls.
2188 struct LocAndDiag {
2189 SourceLocation Loc;
2190 std::optional<SourceLocation> PreviousDeclLoc;
2191 PartialDiagnostic PD;
2192 };
2193 SmallVector<LocAndDiag, 16> DeclDiags;
2194 auto addDiag = [&DeclDiags](SourceLocation Loc, PartialDiagnostic PD) {
2195 DeclDiags.push_back(Elt: LocAndDiag{.Loc: Loc, .PreviousDeclLoc: std::nullopt, .PD: std::move(PD)});
2196 };
2197 auto addDiagWithPrev = [&DeclDiags](SourceLocation Loc,
2198 SourceLocation PreviousDeclLoc,
2199 PartialDiagnostic PD) {
2200 DeclDiags.push_back(Elt: LocAndDiag{.Loc: Loc, .PreviousDeclLoc: PreviousDeclLoc, .PD: std::move(PD)});
2201 };
2202
2203 for (auto *TmpD : S->decls()) {
2204 assert(TmpD && "This decl didn't get pushed??");
2205
2206 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?");
2207 NamedDecl *D = cast<NamedDecl>(Val: TmpD);
2208
2209 // Diagnose unused variables in this scope.
2210 if (!S->hasUnrecoverableErrorOccurred()) {
2211 DiagnoseUnusedDecl(D, DiagReceiver: addDiag);
2212 if (const auto *RD = dyn_cast<RecordDecl>(Val: D))
2213 DiagnoseUnusedNestedTypedefs(D: RD, DiagReceiver: addDiag);
2214 if (VarDecl *VD = dyn_cast<VarDecl>(Val: D)) {
2215 DiagnoseUnusedButSetDecl(VD, DiagReceiver: addDiag);
2216 RefsMinusAssignments.erase(Val: VD);
2217 }
2218 }
2219
2220 if (!D->getDeclName()) continue;
2221
2222 // If this was a forward reference to a label, verify it was defined.
2223 if (LabelDecl *LD = dyn_cast<LabelDecl>(Val: D))
2224 CheckPoppedLabel(L: LD, S&: *this, DiagReceiver: addDiag);
2225
2226 // Partial translation units that are created in incremental processing must
2227 // not clean up the IdResolver because PTUs should take into account the
2228 // declarations that came from previous PTUs.
2229 if (!PP.isIncrementalProcessingEnabled() || getLangOpts().ObjC ||
2230 getLangOpts().CPlusPlus)
2231 IdResolver.RemoveDecl(D);
2232
2233 // Warn on it if we are shadowing a declaration.
2234 auto ShadowI = ShadowingDecls.find(Val: D);
2235 if (ShadowI != ShadowingDecls.end()) {
2236 if (const auto *FD = dyn_cast<FieldDecl>(Val: ShadowI->second)) {
2237 addDiagWithPrev(D->getLocation(), FD->getLocation(),
2238 PDiag(DiagID: diag::warn_ctor_parm_shadows_field)
2239 << D << FD << FD->getParent());
2240 }
2241 ShadowingDecls.erase(I: ShadowI);
2242 }
2243 }
2244
2245 llvm::sort(C&: DeclDiags,
2246 Comp: [](const LocAndDiag &LHS, const LocAndDiag &RHS) -> bool {
2247 // The particular order for diagnostics is not important, as long
2248 // as the order is deterministic. Using the raw location is going
2249 // to generally be in source order unless there are macro
2250 // expansions involved.
2251 return LHS.Loc.getRawEncoding() < RHS.Loc.getRawEncoding();
2252 });
2253 for (const LocAndDiag &D : DeclDiags) {
2254 Diag(Loc: D.Loc, PD: D.PD);
2255 if (D.PreviousDeclLoc)
2256 Diag(Loc: *D.PreviousDeclLoc, DiagID: diag::note_previous_declaration);
2257 }
2258}
2259
2260Scope *Sema::getNonFieldDeclScope(Scope *S) {
2261 while (((S->getFlags() & Scope::DeclScope) == 0) ||
2262 (S->getEntity() && S->getEntity()->isTransparentContext()) ||
2263 (S->isClassScope() && !getLangOpts().CPlusPlus))
2264 S = S->getParent();
2265 return S;
2266}
2267
2268static StringRef getHeaderName(Builtin::Context &BuiltinInfo, unsigned ID,
2269 ASTContext::GetBuiltinTypeError Error) {
2270 switch (Error) {
2271 case ASTContext::GE_None:
2272 return "";
2273 case ASTContext::GE_Missing_type:
2274 return BuiltinInfo.getHeaderName(ID);
2275 case ASTContext::GE_Missing_stdio:
2276 return "stdio.h";
2277 case ASTContext::GE_Missing_setjmp:
2278 return "setjmp.h";
2279 case ASTContext::GE_Missing_ucontext:
2280 return "ucontext.h";
2281 }
2282 llvm_unreachable("unhandled error kind");
2283}
2284
2285FunctionDecl *Sema::CreateBuiltin(IdentifierInfo *II, QualType Type,
2286 unsigned ID, SourceLocation Loc) {
2287 DeclContext *Parent = Context.getTranslationUnitDecl();
2288
2289 if (getLangOpts().CPlusPlus) {
2290 LinkageSpecDecl *CLinkageDecl = LinkageSpecDecl::Create(
2291 C&: Context, DC: Parent, ExternLoc: Loc, LangLoc: Loc, Lang: LinkageSpecLanguageIDs::C, HasBraces: false);
2292 CLinkageDecl->setImplicit();
2293 Parent->addDecl(D: CLinkageDecl);
2294 Parent = CLinkageDecl;
2295 }
2296
2297 ConstexprSpecKind ConstexprKind = ConstexprSpecKind::Unspecified;
2298 if (Context.BuiltinInfo.isImmediate(ID)) {
2299 assert(getLangOpts().CPlusPlus20 &&
2300 "consteval builtins should only be available in C++20 mode");
2301 ConstexprKind = ConstexprSpecKind::Consteval;
2302 }
2303
2304 FunctionDecl *New = FunctionDecl::Create(
2305 C&: Context, DC: Parent, StartLoc: Loc, NLoc: Loc, N: II, T: Type, /*TInfo=*/nullptr, SC: SC_Extern,
2306 UsesFPIntrin: getCurFPFeatures().isFPConstrained(), /*isInlineSpecified=*/false,
2307 hasWrittenPrototype: Type->isFunctionProtoType(), ConstexprKind);
2308 New->setImplicit();
2309 New->addAttr(A: BuiltinAttr::CreateImplicit(Ctx&: Context, ID));
2310
2311 // Create Decl objects for each parameter, adding them to the
2312 // FunctionDecl.
2313 if (const FunctionProtoType *FT = dyn_cast<FunctionProtoType>(Val&: Type)) {
2314 SmallVector<ParmVarDecl *, 16> Params;
2315 for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
2316 ParmVarDecl *parm = ParmVarDecl::Create(
2317 C&: Context, DC: New, StartLoc: SourceLocation(), IdLoc: SourceLocation(), Id: nullptr,
2318 T: FT->getParamType(i), /*TInfo=*/nullptr, S: SC_None, DefArg: nullptr);
2319 parm->setScopeInfo(scopeDepth: 0, parameterIndex: i);
2320 Params.push_back(Elt: parm);
2321 }
2322 New->setParams(Params);
2323 }
2324
2325 AddKnownFunctionAttributes(FD: New);
2326 return New;
2327}
2328
2329NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID,
2330 Scope *S, bool ForRedeclaration,
2331 SourceLocation Loc) {
2332 LookupNecessaryTypesForBuiltin(S, ID);
2333
2334 ASTContext::GetBuiltinTypeError Error;
2335 QualType R = Context.GetBuiltinType(ID, Error);
2336 if (Error) {
2337 if (!ForRedeclaration)
2338 return nullptr;
2339
2340 // If we have a builtin without an associated type we should not emit a
2341 // warning when we were not able to find a type for it.
2342 if (Error == ASTContext::GE_Missing_type ||
2343 Context.BuiltinInfo.allowTypeMismatch(ID))
2344 return nullptr;
2345
2346 // If we could not find a type for setjmp it is because the jmp_buf type was
2347 // not defined prior to the setjmp declaration.
2348 if (Error == ASTContext::GE_Missing_setjmp) {
2349 Diag(Loc, DiagID: diag::warn_implicit_decl_no_jmp_buf)
2350 << Context.BuiltinInfo.getName(ID);
2351 return nullptr;
2352 }
2353
2354 // Generally, we emit a warning that the declaration requires the
2355 // appropriate header.
2356 Diag(Loc, DiagID: diag::warn_implicit_decl_requires_sysheader)
2357 << getHeaderName(BuiltinInfo&: Context.BuiltinInfo, ID, Error)
2358 << Context.BuiltinInfo.getName(ID);
2359 return nullptr;
2360 }
2361
2362 if (!ForRedeclaration &&
2363 (Context.BuiltinInfo.isPredefinedLibFunction(ID) ||
2364 Context.BuiltinInfo.isHeaderDependentFunction(ID))) {
2365 Diag(Loc, DiagID: LangOpts.C99 ? diag::ext_implicit_lib_function_decl_c99
2366 : diag::ext_implicit_lib_function_decl)
2367 << Context.BuiltinInfo.getName(ID) << R;
2368 if (const char *Header = Context.BuiltinInfo.getHeaderName(ID))
2369 Diag(Loc, DiagID: diag::note_include_header_or_declare)
2370 << Header << Context.BuiltinInfo.getName(ID);
2371 }
2372
2373 if (R.isNull())
2374 return nullptr;
2375
2376 FunctionDecl *New = CreateBuiltin(II, Type: R, ID, Loc);
2377 RegisterLocallyScopedExternCDecl(ND: New, S);
2378
2379 // TUScope is the translation-unit scope to insert this function into.
2380 // FIXME: This is hideous. We need to teach PushOnScopeChains to
2381 // relate Scopes to DeclContexts, and probably eliminate CurContext
2382 // entirely, but we're not there yet.
2383 DeclContext *SavedContext = CurContext;
2384 CurContext = New->getDeclContext();
2385 PushOnScopeChains(D: New, S: TUScope);
2386 CurContext = SavedContext;
2387 return New;
2388}
2389
2390/// Typedef declarations don't have linkage, but they still denote the same
2391/// entity if their types are the same.
2392/// FIXME: This is notionally doing the same thing as ASTReaderDecl's
2393/// isSameEntity.
2394static void
2395filterNonConflictingPreviousTypedefDecls(Sema &S, const TypedefNameDecl *Decl,
2396 LookupResult &Previous) {
2397 // This is only interesting when modules are enabled.
2398 if (!S.getLangOpts().Modules && !S.getLangOpts().ModulesLocalVisibility)
2399 return;
2400
2401 // Empty sets are uninteresting.
2402 if (Previous.empty())
2403 return;
2404
2405 LookupResult::Filter Filter = Previous.makeFilter();
2406 while (Filter.hasNext()) {
2407 NamedDecl *Old = Filter.next();
2408
2409 // Non-hidden declarations are never ignored.
2410 if (S.isVisible(D: Old))
2411 continue;
2412
2413 // Declarations of the same entity are not ignored, even if they have
2414 // different linkages.
2415 if (auto *OldTD = dyn_cast<TypedefNameDecl>(Val: Old)) {
2416 if (S.Context.hasSameType(T1: OldTD->getUnderlyingType(),
2417 T2: Decl->getUnderlyingType()))
2418 continue;
2419
2420 // If both declarations give a tag declaration a typedef name for linkage
2421 // purposes, then they declare the same entity.
2422 if (OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true) &&
2423 Decl->getAnonDeclWithTypedefName())
2424 continue;
2425 }
2426
2427 Filter.erase();
2428 }
2429
2430 Filter.done();
2431}
2432
2433bool Sema::isIncompatibleTypedef(const TypeDecl *Old, TypedefNameDecl *New) {
2434 QualType OldType;
2435 if (const TypedefNameDecl *OldTypedef = dyn_cast<TypedefNameDecl>(Val: Old))
2436 OldType = OldTypedef->getUnderlyingType();
2437 else
2438 OldType = Context.getTypeDeclType(Decl: Old);
2439 QualType NewType = New->getUnderlyingType();
2440
2441 if (NewType->isVariablyModifiedType()) {
2442 // Must not redefine a typedef with a variably-modified type.
2443 int Kind = isa<TypeAliasDecl>(Val: Old) ? 1 : 0;
2444 Diag(Loc: New->getLocation(), DiagID: diag::err_redefinition_variably_modified_typedef)
2445 << Kind << NewType;
2446 if (Old->getLocation().isValid())
2447 notePreviousDefinition(Old, New: New->getLocation());
2448 New->setInvalidDecl();
2449 return true;
2450 }
2451
2452 if (OldType != NewType &&
2453 !OldType->isDependentType() &&
2454 !NewType->isDependentType() &&
2455 !Context.hasSameType(T1: OldType, T2: NewType)) {
2456 int Kind = isa<TypeAliasDecl>(Val: Old) ? 1 : 0;
2457 Diag(Loc: New->getLocation(), DiagID: diag::err_redefinition_different_typedef)
2458 << Kind << NewType << OldType;
2459 if (Old->getLocation().isValid())
2460 notePreviousDefinition(Old, New: New->getLocation());
2461 New->setInvalidDecl();
2462 return true;
2463 }
2464 return false;
2465}
2466
2467void Sema::MergeTypedefNameDecl(Scope *S, TypedefNameDecl *New,
2468 LookupResult &OldDecls) {
2469 // If the new decl is known invalid already, don't bother doing any
2470 // merging checks.
2471 if (New->isInvalidDecl()) return;
2472
2473 // Allow multiple definitions for ObjC built-in typedefs.
2474 // FIXME: Verify the underlying types are equivalent!
2475 if (getLangOpts().ObjC) {
2476 const IdentifierInfo *TypeID = New->getIdentifier();
2477 switch (TypeID->getLength()) {
2478 default: break;
2479 case 2:
2480 {
2481 if (!TypeID->isStr(Str: "id"))
2482 break;
2483 QualType T = New->getUnderlyingType();
2484 if (!T->isPointerType())
2485 break;
2486 if (!T->isVoidPointerType()) {
2487 QualType PT = T->castAs<PointerType>()->getPointeeType();
2488 if (!PT->isStructureType())
2489 break;
2490 }
2491 Context.setObjCIdRedefinitionType(T);
2492 // Install the built-in type for 'id', ignoring the current definition.
2493 New->setTypeForDecl(Context.getObjCIdType().getTypePtr());
2494 return;
2495 }
2496 case 5:
2497 if (!TypeID->isStr(Str: "Class"))
2498 break;
2499 Context.setObjCClassRedefinitionType(New->getUnderlyingType());
2500 // Install the built-in type for 'Class', ignoring the current definition.
2501 New->setTypeForDecl(Context.getObjCClassType().getTypePtr());
2502 return;
2503 case 3:
2504 if (!TypeID->isStr(Str: "SEL"))
2505 break;
2506 Context.setObjCSelRedefinitionType(New->getUnderlyingType());
2507 // Install the built-in type for 'SEL', ignoring the current definition.
2508 New->setTypeForDecl(Context.getObjCSelType().getTypePtr());
2509 return;
2510 }
2511 // Fall through - the typedef name was not a builtin type.
2512 }
2513
2514 // Verify the old decl was also a type.
2515 TypeDecl *Old = OldDecls.getAsSingle<TypeDecl>();
2516 if (!Old) {
2517 Diag(Loc: New->getLocation(), DiagID: diag::err_redefinition_different_kind)
2518 << New->getDeclName();
2519
2520 NamedDecl *OldD = OldDecls.getRepresentativeDecl();
2521 if (OldD->getLocation().isValid())
2522 notePreviousDefinition(Old: OldD, New: New->getLocation());
2523
2524 return New->setInvalidDecl();
2525 }
2526
2527 // If the old declaration is invalid, just give up here.
2528 if (Old->isInvalidDecl())
2529 return New->setInvalidDecl();
2530
2531 if (auto *OldTD = dyn_cast<TypedefNameDecl>(Val: Old)) {
2532 auto *OldTag = OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true);
2533 auto *NewTag = New->getAnonDeclWithTypedefName();
2534 NamedDecl *Hidden = nullptr;
2535 if (OldTag && NewTag &&
2536 OldTag->getCanonicalDecl() != NewTag->getCanonicalDecl() &&
2537 !hasVisibleDefinition(D: OldTag, Suggested: &Hidden)) {
2538 // There is a definition of this tag, but it is not visible. Use it
2539 // instead of our tag.
2540 New->setTypeForDecl(OldTD->getTypeForDecl());
2541 if (OldTD->isModed())
2542 New->setModedTypeSourceInfo(unmodedTSI: OldTD->getTypeSourceInfo(),
2543 modedTy: OldTD->getUnderlyingType());
2544 else
2545 New->setTypeSourceInfo(OldTD->getTypeSourceInfo());
2546
2547 // Make the old tag definition visible.
2548 makeMergedDefinitionVisible(ND: Hidden);
2549
2550 // If this was an unscoped enumeration, yank all of its enumerators
2551 // out of the scope.
2552 if (isa<EnumDecl>(Val: NewTag)) {
2553 Scope *EnumScope = getNonFieldDeclScope(S);
2554 for (auto *D : NewTag->decls()) {
2555 auto *ED = cast<EnumConstantDecl>(Val: D);
2556 assert(EnumScope->isDeclScope(ED));
2557 EnumScope->RemoveDecl(D: ED);
2558 IdResolver.RemoveDecl(D: ED);
2559 ED->getLexicalDeclContext()->removeDecl(D: ED);
2560 }
2561 }
2562 }
2563 }
2564
2565 // If the typedef types are not identical, reject them in all languages and
2566 // with any extensions enabled.
2567 if (isIncompatibleTypedef(Old, New))
2568 return;
2569
2570 // The types match. Link up the redeclaration chain and merge attributes if
2571 // the old declaration was a typedef.
2572 if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Val: Old)) {
2573 New->setPreviousDecl(Typedef);
2574 mergeDeclAttributes(New, Old);
2575 }
2576
2577 if (getLangOpts().MicrosoftExt)
2578 return;
2579
2580 if (getLangOpts().CPlusPlus) {
2581 // C++ [dcl.typedef]p2:
2582 // In a given non-class scope, a typedef specifier can be used to
2583 // redefine the name of any type declared in that scope to refer
2584 // to the type to which it already refers.
2585 if (!isa<CXXRecordDecl>(Val: CurContext))
2586 return;
2587
2588 // C++0x [dcl.typedef]p4:
2589 // In a given class scope, a typedef specifier can be used to redefine
2590 // any class-name declared in that scope that is not also a typedef-name
2591 // to refer to the type to which it already refers.
2592 //
2593 // This wording came in via DR424, which was a correction to the
2594 // wording in DR56, which accidentally banned code like:
2595 //
2596 // struct S {
2597 // typedef struct A { } A;
2598 // };
2599 //
2600 // in the C++03 standard. We implement the C++0x semantics, which
2601 // allow the above but disallow
2602 //
2603 // struct S {
2604 // typedef int I;
2605 // typedef int I;
2606 // };
2607 //
2608 // since that was the intent of DR56.
2609 if (!isa<TypedefNameDecl>(Val: Old))
2610 return;
2611
2612 Diag(Loc: New->getLocation(), DiagID: diag::err_redefinition)
2613 << New->getDeclName();
2614 notePreviousDefinition(Old, New: New->getLocation());
2615 return New->setInvalidDecl();
2616 }
2617
2618 // Modules always permit redefinition of typedefs, as does C11.
2619 if (getLangOpts().Modules || getLangOpts().C11)
2620 return;
2621
2622 // If we have a redefinition of a typedef in C, emit a warning. This warning
2623 // is normally mapped to an error, but can be controlled with
2624 // -Wtypedef-redefinition. If either the original or the redefinition is
2625 // in a system header, don't emit this for compatibility with GCC.
2626 if (getDiagnostics().getSuppressSystemWarnings() &&
2627 // Some standard types are defined implicitly in Clang (e.g. OpenCL).
2628 (Old->isImplicit() ||
2629 Context.getSourceManager().isInSystemHeader(Loc: Old->getLocation()) ||
2630 Context.getSourceManager().isInSystemHeader(Loc: New->getLocation())))
2631 return;
2632
2633 Diag(Loc: New->getLocation(), DiagID: diag::ext_redefinition_of_typedef)
2634 << New->getDeclName();
2635 notePreviousDefinition(Old, New: New->getLocation());
2636}
2637
2638/// DeclhasAttr - returns true if decl Declaration already has the target
2639/// attribute.
2640static bool DeclHasAttr(const Decl *D, const Attr *A) {
2641 const OwnershipAttr *OA = dyn_cast<OwnershipAttr>(Val: A);
2642 const AnnotateAttr *Ann = dyn_cast<AnnotateAttr>(Val: A);
2643 for (const auto *i : D->attrs())
2644 if (i->getKind() == A->getKind()) {
2645 if (Ann) {
2646 if (Ann->getAnnotation() == cast<AnnotateAttr>(Val: i)->getAnnotation())
2647 return true;
2648 continue;
2649 }
2650 // FIXME: Don't hardcode this check
2651 if (OA && isa<OwnershipAttr>(Val: i))
2652 return OA->getOwnKind() == cast<OwnershipAttr>(Val: i)->getOwnKind();
2653 return true;
2654 }
2655
2656 return false;
2657}
2658
2659static bool isAttributeTargetADefinition(Decl *D) {
2660 if (VarDecl *VD = dyn_cast<VarDecl>(Val: D))
2661 return VD->isThisDeclarationADefinition();
2662 if (TagDecl *TD = dyn_cast<TagDecl>(Val: D))
2663 return TD->isCompleteDefinition() || TD->isBeingDefined();
2664 return true;
2665}
2666
2667/// Merge alignment attributes from \p Old to \p New, taking into account the
2668/// special semantics of C11's _Alignas specifier and C++11's alignas attribute.
2669///
2670/// \return \c true if any attributes were added to \p New.
2671static bool mergeAlignedAttrs(Sema &S, NamedDecl *New, Decl *Old) {
2672 // Look for alignas attributes on Old, and pick out whichever attribute
2673 // specifies the strictest alignment requirement.
2674 AlignedAttr *OldAlignasAttr = nullptr;
2675 AlignedAttr *OldStrictestAlignAttr = nullptr;
2676 unsigned OldAlign = 0;
2677 for (auto *I : Old->specific_attrs<AlignedAttr>()) {
2678 // FIXME: We have no way of representing inherited dependent alignments
2679 // in a case like:
2680 // template<int A, int B> struct alignas(A) X;
2681 // template<int A, int B> struct alignas(B) X {};
2682 // For now, we just ignore any alignas attributes which are not on the
2683 // definition in such a case.
2684 if (I->isAlignmentDependent())
2685 return false;
2686
2687 if (I->isAlignas())
2688 OldAlignasAttr = I;
2689
2690 unsigned Align = I->getAlignment(Ctx&: S.Context);
2691 if (Align > OldAlign) {
2692 OldAlign = Align;
2693 OldStrictestAlignAttr = I;
2694 }
2695 }
2696
2697 // Look for alignas attributes on New.
2698 AlignedAttr *NewAlignasAttr = nullptr;
2699 unsigned NewAlign = 0;
2700 for (auto *I : New->specific_attrs<AlignedAttr>()) {
2701 if (I->isAlignmentDependent())
2702 return false;
2703
2704 if (I->isAlignas())
2705 NewAlignasAttr = I;
2706
2707 unsigned Align = I->getAlignment(Ctx&: S.Context);
2708 if (Align > NewAlign)
2709 NewAlign = Align;
2710 }
2711
2712 if (OldAlignasAttr && NewAlignasAttr && OldAlign != NewAlign) {
2713 // Both declarations have 'alignas' attributes. We require them to match.
2714 // C++11 [dcl.align]p6 and C11 6.7.5/7 both come close to saying this, but
2715 // fall short. (If two declarations both have alignas, they must both match
2716 // every definition, and so must match each other if there is a definition.)
2717
2718 // If either declaration only contains 'alignas(0)' specifiers, then it
2719 // specifies the natural alignment for the type.
2720 if (OldAlign == 0 || NewAlign == 0) {
2721 QualType Ty;
2722 if (ValueDecl *VD = dyn_cast<ValueDecl>(Val: New))
2723 Ty = VD->getType();
2724 else
2725 Ty = S.Context.getTagDeclType(Decl: cast<TagDecl>(Val: New));
2726
2727 if (OldAlign == 0)
2728 OldAlign = S.Context.getTypeAlign(T: Ty);
2729 if (NewAlign == 0)
2730 NewAlign = S.Context.getTypeAlign(T: Ty);
2731 }
2732
2733 if (OldAlign != NewAlign) {
2734 S.Diag(Loc: NewAlignasAttr->getLocation(), DiagID: diag::err_alignas_mismatch)
2735 << (unsigned)S.Context.toCharUnitsFromBits(BitSize: OldAlign).getQuantity()
2736 << (unsigned)S.Context.toCharUnitsFromBits(BitSize: NewAlign).getQuantity();
2737 S.Diag(Loc: OldAlignasAttr->getLocation(), DiagID: diag::note_previous_declaration);
2738 }
2739 }
2740
2741 if (OldAlignasAttr && !NewAlignasAttr && isAttributeTargetADefinition(D: New)) {
2742 // C++11 [dcl.align]p6:
2743 // if any declaration of an entity has an alignment-specifier,
2744 // every defining declaration of that entity shall specify an
2745 // equivalent alignment.
2746 // C11 6.7.5/7:
2747 // If the definition of an object does not have an alignment
2748 // specifier, any other declaration of that object shall also
2749 // have no alignment specifier.
2750 S.Diag(Loc: New->getLocation(), DiagID: diag::err_alignas_missing_on_definition)
2751 << OldAlignasAttr;
2752 S.Diag(Loc: OldAlignasAttr->getLocation(), DiagID: diag::note_alignas_on_declaration)
2753 << OldAlignasAttr;
2754 }
2755
2756 bool AnyAdded = false;
2757
2758 // Ensure we have an attribute representing the strictest alignment.
2759 if (OldAlign > NewAlign) {
2760 AlignedAttr *Clone = OldStrictestAlignAttr->clone(C&: S.Context);
2761 Clone->setInherited(true);
2762 New->addAttr(A: Clone);
2763 AnyAdded = true;
2764 }
2765
2766 // Ensure we have an alignas attribute if the old declaration had one.
2767 if (OldAlignasAttr && !NewAlignasAttr &&
2768 !(AnyAdded && OldStrictestAlignAttr->isAlignas())) {
2769 AlignedAttr *Clone = OldAlignasAttr->clone(C&: S.Context);
2770 Clone->setInherited(true);
2771 New->addAttr(A: Clone);
2772 AnyAdded = true;
2773 }
2774
2775 return AnyAdded;
2776}
2777
2778#define WANT_DECL_MERGE_LOGIC
2779#include "clang/Sema/AttrParsedAttrImpl.inc"
2780#undef WANT_DECL_MERGE_LOGIC
2781
2782static bool mergeDeclAttribute(Sema &S, NamedDecl *D,
2783 const InheritableAttr *Attr,
2784 Sema::AvailabilityMergeKind AMK) {
2785 // Diagnose any mutual exclusions between the attribute that we want to add
2786 // and attributes that already exist on the declaration.
2787 if (!DiagnoseMutualExclusions(S, D, A: Attr))
2788 return false;
2789
2790 // This function copies an attribute Attr from a previous declaration to the
2791 // new declaration D if the new declaration doesn't itself have that attribute
2792 // yet or if that attribute allows duplicates.
2793 // If you're adding a new attribute that requires logic different from
2794 // "use explicit attribute on decl if present, else use attribute from
2795 // previous decl", for example if the attribute needs to be consistent
2796 // between redeclarations, you need to call a custom merge function here.
2797 InheritableAttr *NewAttr = nullptr;
2798 if (const auto *AA = dyn_cast<AvailabilityAttr>(Val: Attr))
2799 NewAttr = S.mergeAvailabilityAttr(
2800 D, CI: *AA, Platform: AA->getPlatform(), Implicit: AA->isImplicit(), Introduced: AA->getIntroduced(),
2801 Deprecated: AA->getDeprecated(), Obsoleted: AA->getObsoleted(), IsUnavailable: AA->getUnavailable(),
2802 Message: AA->getMessage(), IsStrict: AA->getStrict(), Replacement: AA->getReplacement(), AMK,
2803 Priority: AA->getPriority(), IIEnvironment: AA->getEnvironment());
2804 else if (const auto *VA = dyn_cast<VisibilityAttr>(Val: Attr))
2805 NewAttr = S.mergeVisibilityAttr(D, CI: *VA, Vis: VA->getVisibility());
2806 else if (const auto *VA = dyn_cast<TypeVisibilityAttr>(Val: Attr))
2807 NewAttr = S.mergeTypeVisibilityAttr(D, CI: *VA, Vis: VA->getVisibility());
2808 else if (const auto *ImportA = dyn_cast<DLLImportAttr>(Val: Attr))
2809 NewAttr = S.mergeDLLImportAttr(D, CI: *ImportA);
2810 else if (const auto *ExportA = dyn_cast<DLLExportAttr>(Val: Attr))
2811 NewAttr = S.mergeDLLExportAttr(D, CI: *ExportA);
2812 else if (const auto *EA = dyn_cast<ErrorAttr>(Val: Attr))
2813 NewAttr = S.mergeErrorAttr(D, CI: *EA, NewUserDiagnostic: EA->getUserDiagnostic());
2814 else if (const auto *FA = dyn_cast<FormatAttr>(Val: Attr))
2815 NewAttr = S.mergeFormatAttr(D, CI: *FA, Format: FA->getType(), FormatIdx: FA->getFormatIdx(),
2816 FirstArg: FA->getFirstArg());
2817 else if (const auto *SA = dyn_cast<SectionAttr>(Val: Attr))
2818 NewAttr = S.mergeSectionAttr(D, CI: *SA, Name: SA->getName());
2819 else if (const auto *CSA = dyn_cast<CodeSegAttr>(Val: Attr))
2820 NewAttr = S.mergeCodeSegAttr(D, CI: *CSA, Name: CSA->getName());
2821 else if (const auto *IA = dyn_cast<MSInheritanceAttr>(Val: Attr))
2822 NewAttr = S.mergeMSInheritanceAttr(D, CI: *IA, BestCase: IA->getBestCase(),
2823 Model: IA->getInheritanceModel());
2824 else if (const auto *AA = dyn_cast<AlwaysInlineAttr>(Val: Attr))
2825 NewAttr = S.mergeAlwaysInlineAttr(D, CI: *AA,
2826 Ident: &S.Context.Idents.get(Name: AA->getSpelling()));
2827 else if (S.getLangOpts().CUDA && isa<FunctionDecl>(Val: D) &&
2828 (isa<CUDAHostAttr>(Val: Attr) || isa<CUDADeviceAttr>(Val: Attr) ||
2829 isa<CUDAGlobalAttr>(Val: Attr))) {
2830 // CUDA target attributes are part of function signature for
2831 // overloading purposes and must not be merged.
2832 return false;
2833 } else if (const auto *MA = dyn_cast<MinSizeAttr>(Val: Attr))
2834 NewAttr = S.mergeMinSizeAttr(D, CI: *MA);
2835 else if (const auto *SNA = dyn_cast<SwiftNameAttr>(Val: Attr))
2836 NewAttr = S.Swift().mergeNameAttr(D, SNA: *SNA, Name: SNA->getName());
2837 else if (const auto *OA = dyn_cast<OptimizeNoneAttr>(Val: Attr))
2838 NewAttr = S.mergeOptimizeNoneAttr(D, CI: *OA);
2839 else if (const auto *InternalLinkageA = dyn_cast<InternalLinkageAttr>(Val: Attr))
2840 NewAttr = S.mergeInternalLinkageAttr(D, AL: *InternalLinkageA);
2841 else if (isa<AlignedAttr>(Val: Attr))
2842 // AlignedAttrs are handled separately, because we need to handle all
2843 // such attributes on a declaration at the same time.
2844 NewAttr = nullptr;
2845 else if ((isa<DeprecatedAttr>(Val: Attr) || isa<UnavailableAttr>(Val: Attr)) &&
2846 (AMK == Sema::AMK_Override ||
2847 AMK == Sema::AMK_ProtocolImplementation ||
2848 AMK == Sema::AMK_OptionalProtocolImplementation))
2849 NewAttr = nullptr;
2850 else if (const auto *UA = dyn_cast<UuidAttr>(Val: Attr))
2851 NewAttr = S.mergeUuidAttr(D, CI: *UA, UuidAsWritten: UA->getGuid(), GuidDecl: UA->getGuidDecl());
2852 else if (const auto *IMA = dyn_cast<WebAssemblyImportModuleAttr>(Val: Attr))
2853 NewAttr = S.Wasm().mergeImportModuleAttr(D, AL: *IMA);
2854 else if (const auto *INA = dyn_cast<WebAssemblyImportNameAttr>(Val: Attr))
2855 NewAttr = S.Wasm().mergeImportNameAttr(D, AL: *INA);
2856 else if (const auto *TCBA = dyn_cast<EnforceTCBAttr>(Val: Attr))
2857 NewAttr = S.mergeEnforceTCBAttr(D, AL: *TCBA);
2858 else if (const auto *TCBLA = dyn_cast<EnforceTCBLeafAttr>(Val: Attr))
2859 NewAttr = S.mergeEnforceTCBLeafAttr(D, AL: *TCBLA);
2860 else if (const auto *BTFA = dyn_cast<BTFDeclTagAttr>(Val: Attr))
2861 NewAttr = S.mergeBTFDeclTagAttr(D, AL: *BTFA);
2862 else if (const auto *NT = dyn_cast<HLSLNumThreadsAttr>(Val: Attr))
2863 NewAttr = S.HLSL().mergeNumThreadsAttr(D, AL: *NT, X: NT->getX(), Y: NT->getY(),
2864 Z: NT->getZ());
2865 else if (const auto *SA = dyn_cast<HLSLShaderAttr>(Val: Attr))
2866 NewAttr = S.HLSL().mergeShaderAttr(D, AL: *SA, ShaderType: SA->getType());
2867 else if (isa<SuppressAttr>(Val: Attr))
2868 // Do nothing. Each redeclaration should be suppressed separately.
2869 NewAttr = nullptr;
2870 else if (Attr->shouldInheritEvenIfAlreadyPresent() || !DeclHasAttr(D, A: Attr))
2871 NewAttr = cast<InheritableAttr>(Val: Attr->clone(C&: S.Context));
2872
2873 if (NewAttr) {
2874 NewAttr->setInherited(true);
2875 D->addAttr(A: NewAttr);
2876 if (isa<MSInheritanceAttr>(Val: NewAttr))
2877 S.Consumer.AssignInheritanceModel(RD: cast<CXXRecordDecl>(Val: D));
2878 return true;
2879 }
2880
2881 return false;
2882}
2883
2884static const NamedDecl *getDefinition(const Decl *D) {
2885 if (const TagDecl *TD = dyn_cast<TagDecl>(Val: D))
2886 return TD->getDefinition();
2887 if (const VarDecl *VD = dyn_cast<VarDecl>(Val: D)) {
2888 const VarDecl *Def = VD->getDefinition();
2889 if (Def)
2890 return Def;
2891 return VD->getActingDefinition();
2892 }
2893 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: D)) {
2894 const FunctionDecl *Def = nullptr;
2895 if (FD->isDefined(Definition&: Def, CheckForPendingFriendDefinition: true))
2896 return Def;
2897 }
2898 return nullptr;
2899}
2900
2901static bool hasAttribute(const Decl *D, attr::Kind Kind) {
2902 for (const auto *Attribute : D->attrs())
2903 if (Attribute->getKind() == Kind)
2904 return true;
2905 return false;
2906}
2907
2908/// checkNewAttributesAfterDef - If we already have a definition, check that
2909/// there are no new attributes in this declaration.
2910static void checkNewAttributesAfterDef(Sema &S, Decl *New, const Decl *Old) {
2911 if (!New->hasAttrs())
2912 return;
2913
2914 const NamedDecl *Def = getDefinition(D: Old);
2915 if (!Def || Def == New)
2916 return;
2917
2918 AttrVec &NewAttributes = New->getAttrs();
2919 for (unsigned I = 0, E = NewAttributes.size(); I != E;) {
2920 const Attr *NewAttribute = NewAttributes[I];
2921
2922 if (isa<AliasAttr>(Val: NewAttribute) || isa<IFuncAttr>(Val: NewAttribute)) {
2923 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: New)) {
2924 SkipBodyInfo SkipBody;
2925 S.CheckForFunctionRedefinition(FD, EffectiveDefinition: cast<FunctionDecl>(Val: Def), SkipBody: &SkipBody);
2926
2927 // If we're skipping this definition, drop the "alias" attribute.
2928 if (SkipBody.ShouldSkip) {
2929 NewAttributes.erase(CI: NewAttributes.begin() + I);
2930 --E;
2931 continue;
2932 }
2933 } else {
2934 VarDecl *VD = cast<VarDecl>(Val: New);
2935 unsigned Diag = cast<VarDecl>(Val: Def)->isThisDeclarationADefinition() ==
2936 VarDecl::TentativeDefinition
2937 ? diag::err_alias_after_tentative
2938 : diag::err_redefinition;
2939 S.Diag(Loc: VD->getLocation(), DiagID: Diag) << VD->getDeclName();
2940 if (Diag == diag::err_redefinition)
2941 S.notePreviousDefinition(Old: Def, New: VD->getLocation());
2942 else
2943 S.Diag(Loc: Def->getLocation(), DiagID: diag::note_previous_definition);
2944 VD->setInvalidDecl();
2945 }
2946 ++I;
2947 continue;
2948 }
2949
2950 if (const VarDecl *VD = dyn_cast<VarDecl>(Val: Def)) {
2951 // Tentative definitions are only interesting for the alias check above.
2952 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) {
2953 ++I;
2954 continue;
2955 }
2956 }
2957
2958 if (hasAttribute(D: Def, Kind: NewAttribute->getKind())) {
2959 ++I;
2960 continue; // regular attr merging will take care of validating this.
2961 }
2962
2963 if (isa<C11NoReturnAttr>(Val: NewAttribute)) {
2964 // C's _Noreturn is allowed to be added to a function after it is defined.
2965 ++I;
2966 continue;
2967 } else if (isa<UuidAttr>(Val: NewAttribute)) {
2968 // msvc will allow a subsequent definition to add an uuid to a class
2969 ++I;
2970 continue;
2971 } else if (const AlignedAttr *AA = dyn_cast<AlignedAttr>(Val: NewAttribute)) {
2972 if (AA->isAlignas()) {
2973 // C++11 [dcl.align]p6:
2974 // if any declaration of an entity has an alignment-specifier,
2975 // every defining declaration of that entity shall specify an
2976 // equivalent alignment.
2977 // C11 6.7.5/7:
2978 // If the definition of an object does not have an alignment
2979 // specifier, any other declaration of that object shall also
2980 // have no alignment specifier.
2981 S.Diag(Loc: Def->getLocation(), DiagID: diag::err_alignas_missing_on_definition)
2982 << AA;
2983 S.Diag(Loc: NewAttribute->getLocation(), DiagID: diag::note_alignas_on_declaration)
2984 << AA;
2985 NewAttributes.erase(CI: NewAttributes.begin() + I);
2986 --E;
2987 continue;
2988 }
2989 } else if (isa<LoaderUninitializedAttr>(Val: NewAttribute)) {
2990 // If there is a C definition followed by a redeclaration with this
2991 // attribute then there are two different definitions. In C++, prefer the
2992 // standard diagnostics.
2993 if (!S.getLangOpts().CPlusPlus) {
2994 S.Diag(Loc: NewAttribute->getLocation(),
2995 DiagID: diag::err_loader_uninitialized_redeclaration);
2996 S.Diag(Loc: Def->getLocation(), DiagID: diag::note_previous_definition);
2997 NewAttributes.erase(CI: NewAttributes.begin() + I);
2998 --E;
2999 continue;
3000 }
3001 } else if (isa<SelectAnyAttr>(Val: NewAttribute) &&
3002 cast<VarDecl>(Val: New)->isInline() &&
3003 !cast<VarDecl>(Val: New)->isInlineSpecified()) {
3004 // Don't warn about applying selectany to implicitly inline variables.
3005 // Older compilers and language modes would require the use of selectany
3006 // to make such variables inline, and it would have no effect if we
3007 // honored it.
3008 ++I;
3009 continue;
3010 } else if (isa<OMPDeclareVariantAttr>(Val: NewAttribute)) {
3011 // We allow to add OMP[Begin]DeclareVariantAttr to be added to
3012 // declarations after definitions.
3013 ++I;
3014 continue;
3015 }
3016
3017 S.Diag(Loc: NewAttribute->getLocation(),
3018 DiagID: diag::warn_attribute_precede_definition);
3019 S.Diag(Loc: Def->getLocation(), DiagID: diag::note_previous_definition);
3020 NewAttributes.erase(CI: NewAttributes.begin() + I);
3021 --E;
3022 }
3023}
3024
3025static void diagnoseMissingConstinit(Sema &S, const VarDecl *InitDecl,
3026 const ConstInitAttr *CIAttr,
3027 bool AttrBeforeInit) {
3028 SourceLocation InsertLoc = InitDecl->getInnerLocStart();
3029
3030 // Figure out a good way to write this specifier on the old declaration.
3031 // FIXME: We should just use the spelling of CIAttr, but we don't preserve
3032 // enough of the attribute list spelling information to extract that without
3033 // heroics.
3034 std::string SuitableSpelling;
3035 if (S.getLangOpts().CPlusPlus20)
3036 SuitableSpelling = std::string(
3037 S.PP.getLastMacroWithSpelling(Loc: InsertLoc, Tokens: {tok::kw_constinit}));
3038 if (SuitableSpelling.empty() && S.getLangOpts().CPlusPlus11)
3039 SuitableSpelling = std::string(S.PP.getLastMacroWithSpelling(
3040 Loc: InsertLoc, Tokens: {tok::l_square, tok::l_square,
3041 S.PP.getIdentifierInfo(Name: "clang"), tok::coloncolon,
3042 S.PP.getIdentifierInfo(Name: "require_constant_initialization"),
3043 tok::r_square, tok::r_square}));
3044 if (SuitableSpelling.empty())
3045 SuitableSpelling = std::string(S.PP.getLastMacroWithSpelling(
3046 Loc: InsertLoc, Tokens: {tok::kw___attribute, tok::l_paren, tok::r_paren,
3047 S.PP.getIdentifierInfo(Name: "require_constant_initialization"),
3048 tok::r_paren, tok::r_paren}));
3049 if (SuitableSpelling.empty() && S.getLangOpts().CPlusPlus20)
3050 SuitableSpelling = "constinit";
3051 if (SuitableSpelling.empty() && S.getLangOpts().CPlusPlus11)
3052 SuitableSpelling = "[[clang::require_constant_initialization]]";
3053 if (SuitableSpelling.empty())
3054 SuitableSpelling = "__attribute__((require_constant_initialization))";
3055 SuitableSpelling += " ";
3056
3057 if (AttrBeforeInit) {
3058 // extern constinit int a;
3059 // int a = 0; // error (missing 'constinit'), accepted as extension
3060 assert(CIAttr->isConstinit() && "should not diagnose this for attribute");
3061 S.Diag(Loc: InitDecl->getLocation(), DiagID: diag::ext_constinit_missing)
3062 << InitDecl << FixItHint::CreateInsertion(InsertionLoc: InsertLoc, Code: SuitableSpelling);
3063 S.Diag(Loc: CIAttr->getLocation(), DiagID: diag::note_constinit_specified_here);
3064 } else {
3065 // int a = 0;
3066 // constinit extern int a; // error (missing 'constinit')
3067 S.Diag(Loc: CIAttr->getLocation(),
3068 DiagID: CIAttr->isConstinit() ? diag::err_constinit_added_too_late
3069 : diag::warn_require_const_init_added_too_late)
3070 << FixItHint::CreateRemoval(RemoveRange: SourceRange(CIAttr->getLocation()));
3071 S.Diag(Loc: InitDecl->getLocation(), DiagID: diag::note_constinit_missing_here)
3072 << CIAttr->isConstinit()
3073 << FixItHint::CreateInsertion(InsertionLoc: InsertLoc, Code: SuitableSpelling);
3074 }
3075}
3076
3077void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old,
3078 AvailabilityMergeKind AMK) {
3079 if (UsedAttr *OldAttr = Old->getMostRecentDecl()->getAttr<UsedAttr>()) {
3080 UsedAttr *NewAttr = OldAttr->clone(C&: Context);
3081 NewAttr->setInherited(true);
3082 New->addAttr(A: NewAttr);
3083 }
3084 if (RetainAttr *OldAttr = Old->getMostRecentDecl()->getAttr<RetainAttr>()) {
3085 RetainAttr *NewAttr = OldAttr->clone(C&: Context);
3086 NewAttr->setInherited(true);
3087 New->addAttr(A: NewAttr);
3088 }
3089
3090 if (!Old->hasAttrs() && !New->hasAttrs())
3091 return;
3092
3093 // [dcl.constinit]p1:
3094 // If the [constinit] specifier is applied to any declaration of a
3095 // variable, it shall be applied to the initializing declaration.
3096 const auto *OldConstInit = Old->getAttr<ConstInitAttr>();
3097 const auto *NewConstInit = New->getAttr<ConstInitAttr>();
3098 if (bool(OldConstInit) != bool(NewConstInit)) {
3099 const auto *OldVD = cast<VarDecl>(Val: Old);
3100 auto *NewVD = cast<VarDecl>(Val: New);
3101
3102 // Find the initializing declaration. Note that we might not have linked
3103 // the new declaration into the redeclaration chain yet.
3104 const VarDecl *InitDecl = OldVD->getInitializingDeclaration();
3105 if (!InitDecl &&
3106 (NewVD->hasInit() || NewVD->isThisDeclarationADefinition()))
3107 InitDecl = NewVD;
3108
3109 if (InitDecl == NewVD) {
3110 // This is the initializing declaration. If it would inherit 'constinit',
3111 // that's ill-formed. (Note that we do not apply this to the attribute
3112 // form).
3113 if (OldConstInit && OldConstInit->isConstinit())
3114 diagnoseMissingConstinit(S&: *this, InitDecl: NewVD, CIAttr: OldConstInit,
3115 /*AttrBeforeInit=*/true);
3116 } else if (NewConstInit) {
3117 // This is the first time we've been told that this declaration should
3118 // have a constant initializer. If we already saw the initializing
3119 // declaration, this is too late.
3120 if (InitDecl && InitDecl != NewVD) {
3121 diagnoseMissingConstinit(S&: *this, InitDecl, CIAttr: NewConstInit,
3122 /*AttrBeforeInit=*/false);
3123 NewVD->dropAttr<ConstInitAttr>();
3124 }
3125 }
3126 }
3127
3128 // Attributes declared post-definition are currently ignored.
3129 checkNewAttributesAfterDef(S&: *this, New, Old);
3130
3131 if (AsmLabelAttr *NewA = New->getAttr<AsmLabelAttr>()) {
3132 if (AsmLabelAttr *OldA = Old->getAttr<AsmLabelAttr>()) {
3133 if (!OldA->isEquivalent(Other: NewA)) {
3134 // This redeclaration changes __asm__ label.
3135 Diag(Loc: New->getLocation(), DiagID: diag::err_different_asm_label);
3136 Diag(Loc: OldA->getLocation(), DiagID: diag::note_previous_declaration);
3137 }
3138 } else if (Old->isUsed()) {
3139 // This redeclaration adds an __asm__ label to a declaration that has
3140 // already been ODR-used.
3141 Diag(Loc: New->getLocation(), DiagID: diag::err_late_asm_label_name)
3142 << isa<FunctionDecl>(Val: Old) << New->getAttr<AsmLabelAttr>()->getRange();
3143 }
3144 }
3145
3146 // Re-declaration cannot add abi_tag's.
3147 if (const auto *NewAbiTagAttr = New->getAttr<AbiTagAttr>()) {
3148 if (const auto *OldAbiTagAttr = Old->getAttr<AbiTagAttr>()) {
3149 for (const auto &NewTag : NewAbiTagAttr->tags()) {
3150 if (!llvm::is_contained(Range: OldAbiTagAttr->tags(), Element: NewTag)) {
3151 Diag(Loc: NewAbiTagAttr->getLocation(),
3152 DiagID: diag::err_new_abi_tag_on_redeclaration)
3153 << NewTag;
3154 Diag(Loc: OldAbiTagAttr->getLocation(), DiagID: diag::note_previous_declaration);
3155 }
3156 }
3157 } else {
3158 Diag(Loc: NewAbiTagAttr->getLocation(), DiagID: diag::err_abi_tag_on_redeclaration);
3159 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_declaration);
3160 }
3161 }
3162
3163 // This redeclaration adds a section attribute.
3164 if (New->hasAttr<SectionAttr>() && !Old->hasAttr<SectionAttr>()) {
3165 if (auto *VD = dyn_cast<VarDecl>(Val: New)) {
3166 if (VD->isThisDeclarationADefinition() == VarDecl::DeclarationOnly) {
3167 Diag(Loc: New->getLocation(), DiagID: diag::warn_attribute_section_on_redeclaration);
3168 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_declaration);
3169 }
3170 }
3171 }
3172
3173 // Redeclaration adds code-seg attribute.
3174 const auto *NewCSA = New->getAttr<CodeSegAttr>();
3175 if (NewCSA && !Old->hasAttr<CodeSegAttr>() &&
3176 !NewCSA->isImplicit() && isa<CXXMethodDecl>(Val: New)) {
3177 Diag(Loc: New->getLocation(), DiagID: diag::warn_mismatched_section)
3178 << 0 /*codeseg*/;
3179 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_declaration);
3180 }
3181
3182 if (!Old->hasAttrs())
3183 return;
3184
3185 bool foundAny = New->hasAttrs();
3186
3187 // Ensure that any moving of objects within the allocated map is done before
3188 // we process them.
3189 if (!foundAny) New->setAttrs(AttrVec());
3190
3191 for (auto *I : Old->specific_attrs<InheritableAttr>()) {
3192 // Ignore deprecated/unavailable/availability attributes if requested.
3193 AvailabilityMergeKind LocalAMK = AMK_None;
3194 if (isa<DeprecatedAttr>(Val: I) ||
3195 isa<UnavailableAttr>(Val: I) ||
3196 isa<AvailabilityAttr>(Val: I)) {
3197 switch (AMK) {
3198 case AMK_None:
3199 continue;
3200
3201 case AMK_Redeclaration:
3202 case AMK_Override:
3203 case AMK_ProtocolImplementation:
3204 case AMK_OptionalProtocolImplementation:
3205 LocalAMK = AMK;
3206 break;
3207 }
3208 }
3209
3210 // Already handled.
3211 if (isa<UsedAttr>(Val: I) || isa<RetainAttr>(Val: I))
3212 continue;
3213
3214 if (mergeDeclAttribute(S&: *this, D: New, Attr: I, AMK: LocalAMK))
3215 foundAny = true;
3216 }
3217
3218 if (mergeAlignedAttrs(S&: *this, New, Old))
3219 foundAny = true;
3220
3221 if (!foundAny) New->dropAttrs();
3222}
3223
3224/// mergeParamDeclAttributes - Copy attributes from the old parameter
3225/// to the new one.
3226static void mergeParamDeclAttributes(ParmVarDecl *newDecl,
3227 const ParmVarDecl *oldDecl,
3228 Sema &S) {
3229 // C++11 [dcl.attr.depend]p2:
3230 // The first declaration of a function shall specify the
3231 // carries_dependency attribute for its declarator-id if any declaration
3232 // of the function specifies the carries_dependency attribute.
3233 const CarriesDependencyAttr *CDA = newDecl->getAttr<CarriesDependencyAttr>();
3234 if (CDA && !oldDecl->hasAttr<CarriesDependencyAttr>()) {
3235 S.Diag(Loc: CDA->getLocation(),
3236 DiagID: diag::err_carries_dependency_missing_on_first_decl) << 1/*Param*/;
3237 // Find the first declaration of the parameter.
3238 // FIXME: Should we build redeclaration chains for function parameters?
3239 const FunctionDecl *FirstFD =
3240 cast<FunctionDecl>(Val: oldDecl->getDeclContext())->getFirstDecl();
3241 const ParmVarDecl *FirstVD =
3242 FirstFD->getParamDecl(i: oldDecl->getFunctionScopeIndex());
3243 S.Diag(Loc: FirstVD->getLocation(),
3244 DiagID: diag::note_carries_dependency_missing_first_decl) << 1/*Param*/;
3245 }
3246
3247 // HLSL parameter declarations for inout and out must match between
3248 // declarations. In HLSL inout and out are ambiguous at the call site, but
3249 // have different calling behavior, so you cannot overload a method based on a
3250 // difference between inout and out annotations.
3251 if (S.getLangOpts().HLSL) {
3252 const auto *NDAttr = newDecl->getAttr<HLSLParamModifierAttr>();
3253 const auto *ODAttr = oldDecl->getAttr<HLSLParamModifierAttr>();
3254 // We don't need to cover the case where one declaration doesn't have an
3255 // attribute. The only possible case there is if one declaration has an `in`
3256 // attribute and the other declaration has no attribute. This case is
3257 // allowed since parameters are `in` by default.
3258 if (NDAttr && ODAttr &&
3259 NDAttr->getSpellingListIndex() != ODAttr->getSpellingListIndex()) {
3260 S.Diag(Loc: newDecl->getLocation(), DiagID: diag::err_hlsl_param_qualifier_mismatch)
3261 << NDAttr << newDecl;
3262 S.Diag(Loc: oldDecl->getLocation(), DiagID: diag::note_previous_declaration_as)
3263 << ODAttr;
3264 }
3265 }
3266
3267 if (!oldDecl->hasAttrs())
3268 return;
3269
3270 bool foundAny = newDecl->hasAttrs();
3271
3272 // Ensure that any moving of objects within the allocated map is
3273 // done before we process them.
3274 if (!foundAny) newDecl->setAttrs(AttrVec());
3275
3276 for (const auto *I : oldDecl->specific_attrs<InheritableParamAttr>()) {
3277 if (!DeclHasAttr(D: newDecl, A: I)) {
3278 InheritableAttr *newAttr =
3279 cast<InheritableParamAttr>(Val: I->clone(C&: S.Context));
3280 newAttr->setInherited(true);
3281 newDecl->addAttr(A: newAttr);
3282 foundAny = true;
3283 }
3284 }
3285
3286 if (!foundAny) newDecl->dropAttrs();
3287}
3288
3289static bool EquivalentArrayTypes(QualType Old, QualType New,
3290 const ASTContext &Ctx) {
3291
3292 auto NoSizeInfo = [&Ctx](QualType Ty) {
3293 if (Ty->isIncompleteArrayType() || Ty->isPointerType())
3294 return true;
3295 if (const auto *VAT = Ctx.getAsVariableArrayType(T: Ty))
3296 return VAT->getSizeModifier() == ArraySizeModifier::Star;
3297 return false;
3298 };
3299
3300 // `type[]` is equivalent to `type *` and `type[*]`.
3301 if (NoSizeInfo(Old) && NoSizeInfo(New))
3302 return true;
3303
3304 // Don't try to compare VLA sizes, unless one of them has the star modifier.
3305 if (Old->isVariableArrayType() && New->isVariableArrayType()) {
3306 const auto *OldVAT = Ctx.getAsVariableArrayType(T: Old);
3307 const auto *NewVAT = Ctx.getAsVariableArrayType(T: New);
3308 if ((OldVAT->getSizeModifier() == ArraySizeModifier::Star) ^
3309 (NewVAT->getSizeModifier() == ArraySizeModifier::Star))
3310 return false;
3311 return true;
3312 }
3313
3314 // Only compare size, ignore Size modifiers and CVR.
3315 if (Old->isConstantArrayType() && New->isConstantArrayType()) {
3316 return Ctx.getAsConstantArrayType(T: Old)->getSize() ==
3317 Ctx.getAsConstantArrayType(T: New)->getSize();
3318 }
3319
3320 // Don't try to compare dependent sized array
3321 if (Old->isDependentSizedArrayType() && New->isDependentSizedArrayType()) {
3322 return true;
3323 }
3324
3325 return Old == New;
3326}
3327
3328static void mergeParamDeclTypes(ParmVarDecl *NewParam,
3329 const ParmVarDecl *OldParam,
3330 Sema &S) {
3331 if (auto Oldnullability = OldParam->getType()->getNullability()) {
3332 if (auto Newnullability = NewParam->getType()->getNullability()) {
3333 if (*Oldnullability != *Newnullability) {
3334 S.Diag(Loc: NewParam->getLocation(), DiagID: diag::warn_mismatched_nullability_attr)
3335 << DiagNullabilityKind(
3336 *Newnullability,
3337 ((NewParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
3338 != 0))
3339 << DiagNullabilityKind(
3340 *Oldnullability,
3341 ((OldParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
3342 != 0));
3343 S.Diag(Loc: OldParam->getLocation(), DiagID: diag::note_previous_declaration);
3344 }
3345 } else {
3346 QualType NewT = NewParam->getType();
3347 NewT = S.Context.getAttributedType(
3348 attrKind: AttributedType::getNullabilityAttrKind(kind: *Oldnullability),
3349 modifiedType: NewT, equivalentType: NewT);
3350 NewParam->setType(NewT);
3351 }
3352 }
3353 const auto *OldParamDT = dyn_cast<DecayedType>(Val: OldParam->getType());
3354 const auto *NewParamDT = dyn_cast<DecayedType>(Val: NewParam->getType());
3355 if (OldParamDT && NewParamDT &&
3356 OldParamDT->getPointeeType() == NewParamDT->getPointeeType()) {
3357 QualType OldParamOT = OldParamDT->getOriginalType();
3358 QualType NewParamOT = NewParamDT->getOriginalType();
3359 if (!EquivalentArrayTypes(Old: OldParamOT, New: NewParamOT, Ctx: S.getASTContext())) {
3360 S.Diag(Loc: NewParam->getLocation(), DiagID: diag::warn_inconsistent_array_form)
3361 << NewParam << NewParamOT;
3362 S.Diag(Loc: OldParam->getLocation(), DiagID: diag::note_previous_declaration_as)
3363 << OldParamOT;
3364 }
3365 }
3366}
3367
3368namespace {
3369
3370/// Used in MergeFunctionDecl to keep track of function parameters in
3371/// C.
3372struct GNUCompatibleParamWarning {
3373 ParmVarDecl *OldParm;
3374 ParmVarDecl *NewParm;
3375 QualType PromotedType;
3376};
3377
3378} // end anonymous namespace
3379
3380// Determine whether the previous declaration was a definition, implicit
3381// declaration, or a declaration.
3382template <typename T>
3383static std::pair<diag::kind, SourceLocation>
3384getNoteDiagForInvalidRedeclaration(const T *Old, const T *New) {
3385 diag::kind PrevDiag;
3386 SourceLocation OldLocation = Old->getLocation();
3387 if (Old->isThisDeclarationADefinition())
3388 PrevDiag = diag::note_previous_definition;
3389 else if (Old->isImplicit()) {
3390 PrevDiag = diag::note_previous_implicit_declaration;
3391 if (const auto *FD = dyn_cast<FunctionDecl>(Old)) {
3392 if (FD->getBuiltinID())
3393 PrevDiag = diag::note_previous_builtin_declaration;
3394 }
3395 if (OldLocation.isInvalid())
3396 OldLocation = New->getLocation();
3397 } else
3398 PrevDiag = diag::note_previous_declaration;
3399 return std::make_pair(x&: PrevDiag, y&: OldLocation);
3400}
3401
3402/// canRedefineFunction - checks if a function can be redefined. Currently,
3403/// only extern inline functions can be redefined, and even then only in
3404/// GNU89 mode.
3405static bool canRedefineFunction(const FunctionDecl *FD,
3406 const LangOptions& LangOpts) {
3407 return ((FD->hasAttr<GNUInlineAttr>() || LangOpts.GNUInline) &&
3408 !LangOpts.CPlusPlus &&
3409 FD->isInlineSpecified() &&
3410 FD->getStorageClass() == SC_Extern);
3411}
3412
3413const AttributedType *Sema::getCallingConvAttributedType(QualType T) const {
3414 const AttributedType *AT = T->getAs<AttributedType>();
3415 while (AT && !AT->isCallingConv())
3416 AT = AT->getModifiedType()->getAs<AttributedType>();
3417 return AT;
3418}
3419
3420template <typename T>
3421static bool haveIncompatibleLanguageLinkages(const T *Old, const T *New) {
3422 const DeclContext *DC = Old->getDeclContext();
3423 if (DC->isRecord())
3424 return false;
3425
3426 LanguageLinkage OldLinkage = Old->getLanguageLinkage();
3427 if (OldLinkage == CXXLanguageLinkage && New->isInExternCContext())
3428 return true;
3429 if (OldLinkage == CLanguageLinkage && New->isInExternCXXContext())
3430 return true;
3431 return false;
3432}
3433
3434template<typename T> static bool isExternC(T *D) { return D->isExternC(); }
3435static bool isExternC(VarTemplateDecl *) { return false; }
3436static bool isExternC(FunctionTemplateDecl *) { return false; }
3437
3438/// Check whether a redeclaration of an entity introduced by a
3439/// using-declaration is valid, given that we know it's not an overload
3440/// (nor a hidden tag declaration).
3441template<typename ExpectedDecl>
3442static bool checkUsingShadowRedecl(Sema &S, UsingShadowDecl *OldS,
3443 ExpectedDecl *New) {
3444 // C++11 [basic.scope.declarative]p4:
3445 // Given a set of declarations in a single declarative region, each of
3446 // which specifies the same unqualified name,
3447 // -- they shall all refer to the same entity, or all refer to functions
3448 // and function templates; or
3449 // -- exactly one declaration shall declare a class name or enumeration
3450 // name that is not a typedef name and the other declarations shall all
3451 // refer to the same variable or enumerator, or all refer to functions
3452 // and function templates; in this case the class name or enumeration
3453 // name is hidden (3.3.10).
3454
3455 // C++11 [namespace.udecl]p14:
3456 // If a function declaration in namespace scope or block scope has the
3457 // same name and the same parameter-type-list as a function introduced
3458 // by a using-declaration, and the declarations do not declare the same
3459 // function, the program is ill-formed.
3460
3461 auto *Old = dyn_cast<ExpectedDecl>(OldS->getTargetDecl());
3462 if (Old &&
3463 !Old->getDeclContext()->getRedeclContext()->Equals(
3464 New->getDeclContext()->getRedeclContext()) &&
3465 !(isExternC(Old) && isExternC(New)))
3466 Old = nullptr;
3467
3468 if (!Old) {
3469 S.Diag(New->getLocation(), diag::err_using_decl_conflict_reverse);
3470 S.Diag(Loc: OldS->getTargetDecl()->getLocation(), DiagID: diag::note_using_decl_target);
3471 S.Diag(Loc: OldS->getIntroducer()->getLocation(), DiagID: diag::note_using_decl) << 0;
3472 return true;
3473 }
3474 return false;
3475}
3476
3477static bool hasIdenticalPassObjectSizeAttrs(const FunctionDecl *A,
3478 const FunctionDecl *B) {
3479 assert(A->getNumParams() == B->getNumParams());
3480
3481 auto AttrEq = [](const ParmVarDecl *A, const ParmVarDecl *B) {
3482 const auto *AttrA = A->getAttr<PassObjectSizeAttr>();
3483 const auto *AttrB = B->getAttr<PassObjectSizeAttr>();
3484 if (AttrA == AttrB)
3485 return true;
3486 return AttrA && AttrB && AttrA->getType() == AttrB->getType() &&
3487 AttrA->isDynamic() == AttrB->isDynamic();
3488 };
3489
3490 return std::equal(A->param_begin(), A->param_end(), B->param_begin(), AttrEq);
3491}
3492
3493/// If necessary, adjust the semantic declaration context for a qualified
3494/// declaration to name the correct inline namespace within the qualifier.
3495static void adjustDeclContextForDeclaratorDecl(DeclaratorDecl *NewD,
3496 DeclaratorDecl *OldD) {
3497 // The only case where we need to update the DeclContext is when
3498 // redeclaration lookup for a qualified name finds a declaration
3499 // in an inline namespace within the context named by the qualifier:
3500 //
3501 // inline namespace N { int f(); }
3502 // int ::f(); // Sema DC needs adjusting from :: to N::.
3503 //
3504 // For unqualified declarations, the semantic context *can* change
3505 // along the redeclaration chain (for local extern declarations,
3506 // extern "C" declarations, and friend declarations in particular).
3507 if (!NewD->getQualifier())
3508 return;
3509
3510 // NewD is probably already in the right context.
3511 auto *NamedDC = NewD->getDeclContext()->getRedeclContext();
3512 auto *SemaDC = OldD->getDeclContext()->getRedeclContext();
3513 if (NamedDC->Equals(DC: SemaDC))
3514 return;
3515
3516 assert((NamedDC->InEnclosingNamespaceSetOf(SemaDC) ||
3517 NewD->isInvalidDecl() || OldD->isInvalidDecl()) &&
3518 "unexpected context for redeclaration");
3519
3520 auto *LexDC = NewD->getLexicalDeclContext();
3521 auto FixSemaDC = [=](NamedDecl *D) {
3522 if (!D)
3523 return;
3524 D->setDeclContext(SemaDC);
3525 D->setLexicalDeclContext(LexDC);
3526 };
3527
3528 FixSemaDC(NewD);
3529 if (auto *FD = dyn_cast<FunctionDecl>(Val: NewD))
3530 FixSemaDC(FD->getDescribedFunctionTemplate());
3531 else if (auto *VD = dyn_cast<VarDecl>(Val: NewD))
3532 FixSemaDC(VD->getDescribedVarTemplate());
3533}
3534
3535bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
3536 bool MergeTypeWithOld, bool NewDeclIsDefn) {
3537 // Verify the old decl was also a function.
3538 FunctionDecl *Old = OldD->getAsFunction();
3539 if (!Old) {
3540 if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Val: OldD)) {
3541 if (New->getFriendObjectKind()) {
3542 Diag(Loc: New->getLocation(), DiagID: diag::err_using_decl_friend);
3543 Diag(Loc: Shadow->getTargetDecl()->getLocation(),
3544 DiagID: diag::note_using_decl_target);
3545 Diag(Loc: Shadow->getIntroducer()->getLocation(), DiagID: diag::note_using_decl)
3546 << 0;
3547 return true;
3548 }
3549
3550 // Check whether the two declarations might declare the same function or
3551 // function template.
3552 if (FunctionTemplateDecl *NewTemplate =
3553 New->getDescribedFunctionTemplate()) {
3554 if (checkUsingShadowRedecl<FunctionTemplateDecl>(S&: *this, OldS: Shadow,
3555 New: NewTemplate))
3556 return true;
3557 OldD = Old = cast<FunctionTemplateDecl>(Val: Shadow->getTargetDecl())
3558 ->getAsFunction();
3559 } else {
3560 if (checkUsingShadowRedecl<FunctionDecl>(S&: *this, OldS: Shadow, New))
3561 return true;
3562 OldD = Old = cast<FunctionDecl>(Val: Shadow->getTargetDecl());
3563 }
3564 } else {
3565 Diag(Loc: New->getLocation(), DiagID: diag::err_redefinition_different_kind)
3566 << New->getDeclName();
3567 notePreviousDefinition(Old: OldD, New: New->getLocation());
3568 return true;
3569 }
3570 }
3571
3572 // If the old declaration was found in an inline namespace and the new
3573 // declaration was qualified, update the DeclContext to match.
3574 adjustDeclContextForDeclaratorDecl(NewD: New, OldD: Old);
3575
3576 // If the old declaration is invalid, just give up here.
3577 if (Old->isInvalidDecl())
3578 return true;
3579
3580 // Disallow redeclaration of some builtins.
3581 if (!getASTContext().canBuiltinBeRedeclared(Old)) {
3582 Diag(Loc: New->getLocation(), DiagID: diag::err_builtin_redeclare) << Old->getDeclName();
3583 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_builtin_declaration)
3584 << Old << Old->getType();
3585 return true;
3586 }
3587
3588 diag::kind PrevDiag;
3589 SourceLocation OldLocation;
3590 std::tie(args&: PrevDiag, args&: OldLocation) =
3591 getNoteDiagForInvalidRedeclaration(Old, New);
3592
3593 // Don't complain about this if we're in GNU89 mode and the old function
3594 // is an extern inline function.
3595 // Don't complain about specializations. They are not supposed to have
3596 // storage classes.
3597 if (!isa<CXXMethodDecl>(Val: New) && !isa<CXXMethodDecl>(Val: Old) &&
3598 New->getStorageClass() == SC_Static &&
3599 Old->hasExternalFormalLinkage() &&
3600 !New->getTemplateSpecializationInfo() &&
3601 !canRedefineFunction(FD: Old, LangOpts: getLangOpts())) {
3602 if (getLangOpts().MicrosoftExt) {
3603 Diag(Loc: New->getLocation(), DiagID: diag::ext_static_non_static) << New;
3604 Diag(Loc: OldLocation, DiagID: PrevDiag) << Old << Old->getType();
3605 } else {
3606 Diag(Loc: New->getLocation(), DiagID: diag::err_static_non_static) << New;
3607 Diag(Loc: OldLocation, DiagID: PrevDiag) << Old << Old->getType();
3608 return true;
3609 }
3610 }
3611
3612 if (const auto *ILA = New->getAttr<InternalLinkageAttr>())
3613 if (!Old->hasAttr<InternalLinkageAttr>()) {
3614 Diag(Loc: New->getLocation(), DiagID: diag::err_attribute_missing_on_first_decl)
3615 << ILA;
3616 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_declaration);
3617 New->dropAttr<InternalLinkageAttr>();
3618 }
3619
3620 if (auto *EA = New->getAttr<ErrorAttr>()) {
3621 if (!Old->hasAttr<ErrorAttr>()) {
3622 Diag(Loc: EA->getLocation(), DiagID: diag::err_attribute_missing_on_first_decl) << EA;
3623 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_declaration);
3624 New->dropAttr<ErrorAttr>();
3625 }
3626 }
3627
3628 if (CheckRedeclarationInModule(New, Old))
3629 return true;
3630
3631 if (!getLangOpts().CPlusPlus) {
3632 bool OldOvl = Old->hasAttr<OverloadableAttr>();
3633 if (OldOvl != New->hasAttr<OverloadableAttr>() && !Old->isImplicit()) {
3634 Diag(Loc: New->getLocation(), DiagID: diag::err_attribute_overloadable_mismatch)
3635 << New << OldOvl;
3636
3637 // Try our best to find a decl that actually has the overloadable
3638 // attribute for the note. In most cases (e.g. programs with only one
3639 // broken declaration/definition), this won't matter.
3640 //
3641 // FIXME: We could do this if we juggled some extra state in
3642 // OverloadableAttr, rather than just removing it.
3643 const Decl *DiagOld = Old;
3644 if (OldOvl) {
3645 auto OldIter = llvm::find_if(Range: Old->redecls(), P: [](const Decl *D) {
3646 const auto *A = D->getAttr<OverloadableAttr>();
3647 return A && !A->isImplicit();
3648 });
3649 // If we've implicitly added *all* of the overloadable attrs to this
3650 // chain, emitting a "previous redecl" note is pointless.
3651 DiagOld = OldIter == Old->redecls_end() ? nullptr : *OldIter;
3652 }
3653
3654 if (DiagOld)
3655 Diag(Loc: DiagOld->getLocation(),
3656 DiagID: diag::note_attribute_overloadable_prev_overload)
3657 << OldOvl;
3658
3659 if (OldOvl)
3660 New->addAttr(A: OverloadableAttr::CreateImplicit(Ctx&: Context));
3661 else
3662 New->dropAttr<OverloadableAttr>();
3663 }
3664 }
3665
3666 // It is not permitted to redeclare an SME function with different SME
3667 // attributes.
3668 if (IsInvalidSMECallConversion(FromType: Old->getType(), ToType: New->getType())) {
3669 Diag(Loc: New->getLocation(), DiagID: diag::err_sme_attr_mismatch)
3670 << New->getType() << Old->getType();
3671 Diag(Loc: OldLocation, DiagID: diag::note_previous_declaration);
3672 return true;
3673 }
3674
3675 // If a function is first declared with a calling convention, but is later
3676 // declared or defined without one, all following decls assume the calling
3677 // convention of the first.
3678 //
3679 // It's OK if a function is first declared without a calling convention,
3680 // but is later declared or defined with the default calling convention.
3681 //
3682 // To test if either decl has an explicit calling convention, we look for
3683 // AttributedType sugar nodes on the type as written. If they are missing or
3684 // were canonicalized away, we assume the calling convention was implicit.
3685 //
3686 // Note also that we DO NOT return at this point, because we still have
3687 // other tests to run.
3688 QualType OldQType = Context.getCanonicalType(T: Old->getType());
3689 QualType NewQType = Context.getCanonicalType(T: New->getType());
3690 const FunctionType *OldType = cast<FunctionType>(Val&: OldQType);
3691 const FunctionType *NewType = cast<FunctionType>(Val&: NewQType);
3692 FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo();
3693 FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo();
3694 bool RequiresAdjustment = false;
3695
3696 if (OldTypeInfo.getCC() != NewTypeInfo.getCC()) {
3697 FunctionDecl *First = Old->getFirstDecl();
3698 const FunctionType *FT =
3699 First->getType().getCanonicalType()->castAs<FunctionType>();
3700 FunctionType::ExtInfo FI = FT->getExtInfo();
3701 bool NewCCExplicit = getCallingConvAttributedType(T: New->getType());
3702 if (!NewCCExplicit) {
3703 // Inherit the CC from the previous declaration if it was specified
3704 // there but not here.
3705 NewTypeInfo = NewTypeInfo.withCallingConv(cc: OldTypeInfo.getCC());
3706 RequiresAdjustment = true;
3707 } else if (Old->getBuiltinID()) {
3708 // Builtin attribute isn't propagated to the new one yet at this point,
3709 // so we check if the old one is a builtin.
3710
3711 // Calling Conventions on a Builtin aren't really useful and setting a
3712 // default calling convention and cdecl'ing some builtin redeclarations is
3713 // common, so warn and ignore the calling convention on the redeclaration.
3714 Diag(Loc: New->getLocation(), DiagID: diag::warn_cconv_unsupported)
3715 << FunctionType::getNameForCallConv(CC: NewTypeInfo.getCC())
3716 << (int)CallingConventionIgnoredReason::BuiltinFunction;
3717 NewTypeInfo = NewTypeInfo.withCallingConv(cc: OldTypeInfo.getCC());
3718 RequiresAdjustment = true;
3719 } else {
3720 // Calling conventions aren't compatible, so complain.
3721 bool FirstCCExplicit = getCallingConvAttributedType(T: First->getType());
3722 Diag(Loc: New->getLocation(), DiagID: diag::err_cconv_change)
3723 << FunctionType::getNameForCallConv(CC: NewTypeInfo.getCC())
3724 << !FirstCCExplicit
3725 << (!FirstCCExplicit ? "" :
3726 FunctionType::getNameForCallConv(CC: FI.getCC()));
3727
3728 // Put the note on the first decl, since it is the one that matters.
3729 Diag(Loc: First->getLocation(), DiagID: diag::note_previous_declaration);
3730 return true;
3731 }
3732 }
3733
3734 // FIXME: diagnose the other way around?
3735 if (OldTypeInfo.getNoReturn() && !NewTypeInfo.getNoReturn()) {
3736 NewTypeInfo = NewTypeInfo.withNoReturn(noReturn: true);
3737 RequiresAdjustment = true;
3738 }
3739
3740 // Merge regparm attribute.
3741 if (OldTypeInfo.getHasRegParm() != NewTypeInfo.getHasRegParm() ||
3742 OldTypeInfo.getRegParm() != NewTypeInfo.getRegParm()) {
3743 if (NewTypeInfo.getHasRegParm()) {
3744 Diag(Loc: New->getLocation(), DiagID: diag::err_regparm_mismatch)
3745 << NewType->getRegParmType()
3746 << OldType->getRegParmType();
3747 Diag(Loc: OldLocation, DiagID: diag::note_previous_declaration);
3748 return true;
3749 }
3750
3751 NewTypeInfo = NewTypeInfo.withRegParm(RegParm: OldTypeInfo.getRegParm());
3752 RequiresAdjustment = true;
3753 }
3754
3755 // Merge ns_returns_retained attribute.
3756 if (OldTypeInfo.getProducesResult() != NewTypeInfo.getProducesResult()) {
3757 if (NewTypeInfo.getProducesResult()) {
3758 Diag(Loc: New->getLocation(), DiagID: diag::err_function_attribute_mismatch)
3759 << "'ns_returns_retained'";
3760 Diag(Loc: OldLocation, DiagID: diag::note_previous_declaration);
3761 return true;
3762 }
3763
3764 NewTypeInfo = NewTypeInfo.withProducesResult(producesResult: true);
3765 RequiresAdjustment = true;
3766 }
3767
3768 if (OldTypeInfo.getNoCallerSavedRegs() !=
3769 NewTypeInfo.getNoCallerSavedRegs()) {
3770 if (NewTypeInfo.getNoCallerSavedRegs()) {
3771 AnyX86NoCallerSavedRegistersAttr *Attr =
3772 New->getAttr<AnyX86NoCallerSavedRegistersAttr>();
3773 Diag(Loc: New->getLocation(), DiagID: diag::err_function_attribute_mismatch) << Attr;
3774 Diag(Loc: OldLocation, DiagID: diag::note_previous_declaration);
3775 return true;
3776 }
3777
3778 NewTypeInfo = NewTypeInfo.withNoCallerSavedRegs(noCallerSavedRegs: true);
3779 RequiresAdjustment = true;
3780 }
3781
3782 if (RequiresAdjustment) {
3783 const FunctionType *AdjustedType = New->getType()->getAs<FunctionType>();
3784 AdjustedType = Context.adjustFunctionType(Fn: AdjustedType, EInfo: NewTypeInfo);
3785 New->setType(QualType(AdjustedType, 0));
3786 NewQType = Context.getCanonicalType(T: New->getType());
3787 }
3788
3789 // If this redeclaration makes the function inline, we may need to add it to
3790 // UndefinedButUsed.
3791 if (!Old->isInlined() && New->isInlined() &&
3792 !New->hasAttr<GNUInlineAttr>() &&
3793 !getLangOpts().GNUInline &&
3794 Old->isUsed(CheckUsedAttr: false) &&
3795 !Old->isDefined() && !New->isThisDeclarationADefinition())
3796 UndefinedButUsed.insert(KV: std::make_pair(x: Old->getCanonicalDecl(),
3797 y: SourceLocation()));
3798
3799 // If this redeclaration makes it newly gnu_inline, we don't want to warn
3800 // about it.
3801 if (New->hasAttr<GNUInlineAttr>() &&
3802 Old->isInlined() && !Old->hasAttr<GNUInlineAttr>()) {
3803 UndefinedButUsed.erase(Key: Old->getCanonicalDecl());
3804 }
3805
3806 // If pass_object_size params don't match up perfectly, this isn't a valid
3807 // redeclaration.
3808 if (Old->getNumParams() > 0 && Old->getNumParams() == New->getNumParams() &&
3809 !hasIdenticalPassObjectSizeAttrs(A: Old, B: New)) {
3810 Diag(Loc: New->getLocation(), DiagID: diag::err_different_pass_object_size_params)
3811 << New->getDeclName();
3812 Diag(Loc: OldLocation, DiagID: PrevDiag) << Old << Old->getType();
3813 return true;
3814 }
3815
3816 QualType OldQTypeForComparison = OldQType;
3817 if (Context.hasAnyFunctionEffects()) {
3818 const auto OldFX = Old->getFunctionEffects();
3819 const auto NewFX = New->getFunctionEffects();
3820 if (OldFX != NewFX) {
3821 const auto Diffs = FunctionEffectDifferences(OldFX, NewFX);
3822 for (const auto &Diff : Diffs) {
3823 if (Diff.shouldDiagnoseRedeclaration(OldFunction: *Old, OldFX, NewFunction: *New, NewFX)) {
3824 Diag(Loc: New->getLocation(),
3825 DiagID: diag::warn_mismatched_func_effect_redeclaration)
3826 << Diff.effectName();
3827 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_declaration);
3828 }
3829 }
3830 // Following a warning, we could skip merging effects from the previous
3831 // declaration, but that would trigger an additional "conflicting types"
3832 // error.
3833 if (const auto *NewFPT = NewQType->getAs<FunctionProtoType>()) {
3834 FunctionEffectSet::Conflicts MergeErrs;
3835 FunctionEffectSet MergedFX =
3836 FunctionEffectSet::getUnion(LHS: OldFX, RHS: NewFX, Errs&: MergeErrs);
3837 if (!MergeErrs.empty())
3838 diagnoseFunctionEffectMergeConflicts(Errs: MergeErrs, NewLoc: New->getLocation(),
3839 OldLoc: Old->getLocation());
3840
3841 FunctionProtoType::ExtProtoInfo EPI = NewFPT->getExtProtoInfo();
3842 EPI.FunctionEffects = FunctionEffectsRef(MergedFX);
3843 QualType ModQT = Context.getFunctionType(ResultTy: NewFPT->getReturnType(),
3844 Args: NewFPT->getParamTypes(), EPI);
3845
3846 New->setType(ModQT);
3847 NewQType = New->getType();
3848
3849 // Revise OldQTForComparison to include the merged effects,
3850 // so as not to fail due to differences later.
3851 if (const auto *OldFPT = OldQType->getAs<FunctionProtoType>()) {
3852 EPI = OldFPT->getExtProtoInfo();
3853 EPI.FunctionEffects = FunctionEffectsRef(MergedFX);
3854 OldQTypeForComparison = Context.getFunctionType(
3855 ResultTy: OldFPT->getReturnType(), Args: OldFPT->getParamTypes(), EPI);
3856 }
3857 }
3858 }
3859 }
3860
3861 if (getLangOpts().CPlusPlus) {
3862 OldQType = Context.getCanonicalType(T: Old->getType());
3863 NewQType = Context.getCanonicalType(T: New->getType());
3864
3865 // Go back to the type source info to compare the declared return types,
3866 // per C++1y [dcl.type.auto]p13:
3867 // Redeclarations or specializations of a function or function template
3868 // with a declared return type that uses a placeholder type shall also
3869 // use that placeholder, not a deduced type.
3870 QualType OldDeclaredReturnType = Old->getDeclaredReturnType();
3871 QualType NewDeclaredReturnType = New->getDeclaredReturnType();
3872 if (!Context.hasSameType(T1: OldDeclaredReturnType, T2: NewDeclaredReturnType) &&
3873 canFullyTypeCheckRedeclaration(NewD: New, OldD: Old, NewT: NewDeclaredReturnType,
3874 OldT: OldDeclaredReturnType)) {
3875 QualType ResQT;
3876 if (NewDeclaredReturnType->isObjCObjectPointerType() &&
3877 OldDeclaredReturnType->isObjCObjectPointerType())
3878 // FIXME: This does the wrong thing for a deduced return type.
3879 ResQT = Context.mergeObjCGCQualifiers(NewQType, OldQType);
3880 if (ResQT.isNull()) {
3881 if (New->isCXXClassMember() && New->isOutOfLine())
3882 Diag(Loc: New->getLocation(), DiagID: diag::err_member_def_does_not_match_ret_type)
3883 << New << New->getReturnTypeSourceRange();
3884 else
3885 Diag(Loc: New->getLocation(), DiagID: diag::err_ovl_diff_return_type)
3886 << New->getReturnTypeSourceRange();
3887 Diag(Loc: OldLocation, DiagID: PrevDiag) << Old << Old->getType()
3888 << Old->getReturnTypeSourceRange();
3889 return true;
3890 }
3891 else
3892 NewQType = ResQT;
3893 }
3894
3895 QualType OldReturnType = OldType->getReturnType();
3896 QualType NewReturnType = cast<FunctionType>(Val&: NewQType)->getReturnType();
3897 if (OldReturnType != NewReturnType) {
3898 // If this function has a deduced return type and has already been
3899 // defined, copy the deduced value from the old declaration.
3900 AutoType *OldAT = Old->getReturnType()->getContainedAutoType();
3901 if (OldAT && OldAT->isDeduced()) {
3902 QualType DT = OldAT->getDeducedType();
3903 if (DT.isNull()) {
3904 New->setType(SubstAutoTypeDependent(TypeWithAuto: New->getType()));
3905 NewQType = Context.getCanonicalType(T: SubstAutoTypeDependent(TypeWithAuto: NewQType));
3906 } else {
3907 New->setType(SubstAutoType(TypeWithAuto: New->getType(), Replacement: DT));
3908 NewQType = Context.getCanonicalType(T: SubstAutoType(TypeWithAuto: NewQType, Replacement: DT));
3909 }
3910 }
3911 }
3912
3913 const CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Val: Old);
3914 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(Val: New);
3915 if (OldMethod && NewMethod) {
3916 // Preserve triviality.
3917 NewMethod->setTrivial(OldMethod->isTrivial());
3918
3919 // MSVC allows explicit template specialization at class scope:
3920 // 2 CXXMethodDecls referring to the same function will be injected.
3921 // We don't want a redeclaration error.
3922 bool IsClassScopeExplicitSpecialization =
3923 OldMethod->isFunctionTemplateSpecialization() &&
3924 NewMethod->isFunctionTemplateSpecialization();
3925 bool isFriend = NewMethod->getFriendObjectKind();
3926
3927 if (!isFriend && NewMethod->getLexicalDeclContext()->isRecord() &&
3928 !IsClassScopeExplicitSpecialization) {
3929 // -- Member function declarations with the same name and the
3930 // same parameter types cannot be overloaded if any of them
3931 // is a static member function declaration.
3932 if (OldMethod->isStatic() != NewMethod->isStatic()) {
3933 Diag(Loc: New->getLocation(), DiagID: diag::err_ovl_static_nonstatic_member);
3934 Diag(Loc: OldLocation, DiagID: PrevDiag) << Old << Old->getType();
3935 return true;
3936 }
3937
3938 // C++ [class.mem]p1:
3939 // [...] A member shall not be declared twice in the
3940 // member-specification, except that a nested class or member
3941 // class template can be declared and then later defined.
3942 if (!inTemplateInstantiation()) {
3943 unsigned NewDiag;
3944 if (isa<CXXConstructorDecl>(Val: OldMethod))
3945 NewDiag = diag::err_constructor_redeclared;
3946 else if (isa<CXXDestructorDecl>(Val: NewMethod))
3947 NewDiag = diag::err_destructor_redeclared;
3948 else if (isa<CXXConversionDecl>(Val: NewMethod))
3949 NewDiag = diag::err_conv_function_redeclared;
3950 else
3951 NewDiag = diag::err_member_redeclared;
3952
3953 Diag(Loc: New->getLocation(), DiagID: NewDiag);
3954 } else {
3955 Diag(Loc: New->getLocation(), DiagID: diag::err_member_redeclared_in_instantiation)
3956 << New << New->getType();
3957 }
3958 Diag(Loc: OldLocation, DiagID: PrevDiag) << Old << Old->getType();
3959 return true;
3960
3961 // Complain if this is an explicit declaration of a special
3962 // member that was initially declared implicitly.
3963 //
3964 // As an exception, it's okay to befriend such methods in order
3965 // to permit the implicit constructor/destructor/operator calls.
3966 } else if (OldMethod->isImplicit()) {
3967 if (isFriend) {
3968 NewMethod->setImplicit();
3969 } else {
3970 Diag(Loc: NewMethod->getLocation(),
3971 DiagID: diag::err_definition_of_implicitly_declared_member)
3972 << New << llvm::to_underlying(E: getSpecialMember(MD: OldMethod));
3973 return true;
3974 }
3975 } else if (OldMethod->getFirstDecl()->isExplicitlyDefaulted() && !isFriend) {
3976 Diag(Loc: NewMethod->getLocation(),
3977 DiagID: diag::err_definition_of_explicitly_defaulted_member)
3978 << llvm::to_underlying(E: getSpecialMember(MD: OldMethod));
3979 return true;
3980 }
3981 }
3982
3983 // C++1z [over.load]p2
3984 // Certain function declarations cannot be overloaded:
3985 // -- Function declarations that differ only in the return type,
3986 // the exception specification, or both cannot be overloaded.
3987
3988 // Check the exception specifications match. This may recompute the type of
3989 // both Old and New if it resolved exception specifications, so grab the
3990 // types again after this. Because this updates the type, we do this before
3991 // any of the other checks below, which may update the "de facto" NewQType
3992 // but do not necessarily update the type of New.
3993 if (CheckEquivalentExceptionSpec(Old, New))
3994 return true;
3995
3996 // C++11 [dcl.attr.noreturn]p1:
3997 // The first declaration of a function shall specify the noreturn
3998 // attribute if any declaration of that function specifies the noreturn
3999 // attribute.
4000 if (const auto *NRA = New->getAttr<CXX11NoReturnAttr>())
4001 if (!Old->hasAttr<CXX11NoReturnAttr>()) {
4002 Diag(Loc: NRA->getLocation(), DiagID: diag::err_attribute_missing_on_first_decl)
4003 << NRA;
4004 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_declaration);
4005 }
4006
4007 // C++11 [dcl.attr.depend]p2:
4008 // The first declaration of a function shall specify the
4009 // carries_dependency attribute for its declarator-id if any declaration
4010 // of the function specifies the carries_dependency attribute.
4011 const CarriesDependencyAttr *CDA = New->getAttr<CarriesDependencyAttr>();
4012 if (CDA && !Old->hasAttr<CarriesDependencyAttr>()) {
4013 Diag(Loc: CDA->getLocation(),
4014 DiagID: diag::err_carries_dependency_missing_on_first_decl) << 0/*Function*/;
4015 Diag(Loc: Old->getFirstDecl()->getLocation(),
4016 DiagID: diag::note_carries_dependency_missing_first_decl) << 0/*Function*/;
4017 }
4018
4019 // (C++98 8.3.5p3):
4020 // All declarations for a function shall agree exactly in both the
4021 // return type and the parameter-type-list.
4022 // We also want to respect all the extended bits except noreturn.
4023
4024 // noreturn should now match unless the old type info didn't have it.
4025 if (!OldTypeInfo.getNoReturn() && NewTypeInfo.getNoReturn()) {
4026 auto *OldType = OldQTypeForComparison->castAs<FunctionProtoType>();
4027 const FunctionType *OldTypeForComparison
4028 = Context.adjustFunctionType(Fn: OldType, EInfo: OldTypeInfo.withNoReturn(noReturn: true));
4029 OldQTypeForComparison = QualType(OldTypeForComparison, 0);
4030 assert(OldQTypeForComparison.isCanonical());
4031 }
4032
4033 if (haveIncompatibleLanguageLinkages(Old, New)) {
4034 // As a special case, retain the language linkage from previous
4035 // declarations of a friend function as an extension.
4036 //
4037 // This liberal interpretation of C++ [class.friend]p3 matches GCC/MSVC
4038 // and is useful because there's otherwise no way to specify language
4039 // linkage within class scope.
4040 //
4041 // Check cautiously as the friend object kind isn't yet complete.
4042 if (New->getFriendObjectKind() != Decl::FOK_None) {
4043 Diag(Loc: New->getLocation(), DiagID: diag::ext_retained_language_linkage) << New;
4044 Diag(Loc: OldLocation, DiagID: PrevDiag);
4045 } else {
4046 Diag(Loc: New->getLocation(), DiagID: diag::err_different_language_linkage) << New;
4047 Diag(Loc: OldLocation, DiagID: PrevDiag);
4048 return true;
4049 }
4050 }
4051
4052 // If the function types are compatible, merge the declarations. Ignore the
4053 // exception specifier because it was already checked above in
4054 // CheckEquivalentExceptionSpec, and we don't want follow-on diagnostics
4055 // about incompatible types under -fms-compatibility.
4056 if (Context.hasSameFunctionTypeIgnoringExceptionSpec(T: OldQTypeForComparison,
4057 U: NewQType))
4058 return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
4059
4060 // If the types are imprecise (due to dependent constructs in friends or
4061 // local extern declarations), it's OK if they differ. We'll check again
4062 // during instantiation.
4063 if (!canFullyTypeCheckRedeclaration(NewD: New, OldD: Old, NewT: NewQType, OldT: OldQType))
4064 return false;
4065
4066 // Fall through for conflicting redeclarations and redefinitions.
4067 }
4068
4069 // C: Function types need to be compatible, not identical. This handles
4070 // duplicate function decls like "void f(int); void f(enum X);" properly.
4071 if (!getLangOpts().CPlusPlus) {
4072 // C99 6.7.5.3p15: ...If one type has a parameter type list and the other
4073 // type is specified by a function definition that contains a (possibly
4074 // empty) identifier list, both shall agree in the number of parameters
4075 // and the type of each parameter shall be compatible with the type that
4076 // results from the application of default argument promotions to the
4077 // type of the corresponding identifier. ...
4078 // This cannot be handled by ASTContext::typesAreCompatible() because that
4079 // doesn't know whether the function type is for a definition or not when
4080 // eventually calling ASTContext::mergeFunctionTypes(). The only situation
4081 // we need to cover here is that the number of arguments agree as the
4082 // default argument promotion rules were already checked by
4083 // ASTContext::typesAreCompatible().
4084 if (Old->hasPrototype() && !New->hasWrittenPrototype() && NewDeclIsDefn &&
4085 Old->getNumParams() != New->getNumParams() && !Old->isImplicit()) {
4086 if (Old->hasInheritedPrototype())
4087 Old = Old->getCanonicalDecl();
4088 Diag(Loc: New->getLocation(), DiagID: diag::err_conflicting_types) << New;
4089 Diag(Loc: Old->getLocation(), DiagID: PrevDiag) << Old << Old->getType();
4090 return true;
4091 }
4092
4093 // If we are merging two functions where only one of them has a prototype,
4094 // we may have enough information to decide to issue a diagnostic that the
4095 // function without a prototype will change behavior in C23. This handles
4096 // cases like:
4097 // void i(); void i(int j);
4098 // void i(int j); void i();
4099 // void i(); void i(int j) {}
4100 // See ActOnFinishFunctionBody() for other cases of the behavior change
4101 // diagnostic. See GetFullTypeForDeclarator() for handling of a function
4102 // type without a prototype.
4103 if (New->hasWrittenPrototype() != Old->hasWrittenPrototype() &&
4104 !New->isImplicit() && !Old->isImplicit()) {
4105 const FunctionDecl *WithProto, *WithoutProto;
4106 if (New->hasWrittenPrototype()) {
4107 WithProto = New;
4108 WithoutProto = Old;
4109 } else {
4110 WithProto = Old;
4111 WithoutProto = New;
4112 }
4113
4114 if (WithProto->getNumParams() != 0) {
4115 if (WithoutProto->getBuiltinID() == 0 && !WithoutProto->isImplicit()) {
4116 // The one without the prototype will be changing behavior in C23, so
4117 // warn about that one so long as it's a user-visible declaration.
4118 bool IsWithoutProtoADef = false, IsWithProtoADef = false;
4119 if (WithoutProto == New)
4120 IsWithoutProtoADef = NewDeclIsDefn;
4121 else
4122 IsWithProtoADef = NewDeclIsDefn;
4123 Diag(Loc: WithoutProto->getLocation(),
4124 DiagID: diag::warn_non_prototype_changes_behavior)
4125 << IsWithoutProtoADef << (WithoutProto->getNumParams() ? 0 : 1)
4126 << (WithoutProto == Old) << IsWithProtoADef;
4127
4128 // The reason the one without the prototype will be changing behavior
4129 // is because of the one with the prototype, so note that so long as
4130 // it's a user-visible declaration. There is one exception to this:
4131 // when the new declaration is a definition without a prototype, the
4132 // old declaration with a prototype is not the cause of the issue,
4133 // and that does not need to be noted because the one with a
4134 // prototype will not change behavior in C23.
4135 if (WithProto->getBuiltinID() == 0 && !WithProto->isImplicit() &&
4136 !IsWithoutProtoADef)
4137 Diag(Loc: WithProto->getLocation(), DiagID: diag::note_conflicting_prototype);
4138 }
4139 }
4140 }
4141
4142 if (Context.typesAreCompatible(T1: OldQType, T2: NewQType)) {
4143 const FunctionType *OldFuncType = OldQType->getAs<FunctionType>();
4144 const FunctionType *NewFuncType = NewQType->getAs<FunctionType>();
4145 const FunctionProtoType *OldProto = nullptr;
4146 if (MergeTypeWithOld && isa<FunctionNoProtoType>(Val: NewFuncType) &&
4147 (OldProto = dyn_cast<FunctionProtoType>(Val: OldFuncType))) {
4148 // The old declaration provided a function prototype, but the
4149 // new declaration does not. Merge in the prototype.
4150 assert(!OldProto->hasExceptionSpec() && "Exception spec in C");
4151 NewQType = Context.getFunctionType(ResultTy: NewFuncType->getReturnType(),
4152 Args: OldProto->getParamTypes(),
4153 EPI: OldProto->getExtProtoInfo());
4154 New->setType(NewQType);
4155 New->setHasInheritedPrototype();
4156
4157 // Synthesize parameters with the same types.
4158 SmallVector<ParmVarDecl *, 16> Params;
4159 for (const auto &ParamType : OldProto->param_types()) {
4160 ParmVarDecl *Param = ParmVarDecl::Create(
4161 C&: Context, DC: New, StartLoc: SourceLocation(), IdLoc: SourceLocation(), Id: nullptr,
4162 T: ParamType, /*TInfo=*/nullptr, S: SC_None, DefArg: nullptr);
4163 Param->setScopeInfo(scopeDepth: 0, parameterIndex: Params.size());
4164 Param->setImplicit();
4165 Params.push_back(Elt: Param);
4166 }
4167
4168 New->setParams(Params);
4169 }
4170
4171 return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
4172 }
4173 }
4174
4175 // Check if the function types are compatible when pointer size address
4176 // spaces are ignored.
4177 if (Context.hasSameFunctionTypeIgnoringPtrSizes(T: OldQType, U: NewQType))
4178 return false;
4179
4180 // GNU C permits a K&R definition to follow a prototype declaration
4181 // if the declared types of the parameters in the K&R definition
4182 // match the types in the prototype declaration, even when the
4183 // promoted types of the parameters from the K&R definition differ
4184 // from the types in the prototype. GCC then keeps the types from
4185 // the prototype.
4186 //
4187 // If a variadic prototype is followed by a non-variadic K&R definition,
4188 // the K&R definition becomes variadic. This is sort of an edge case, but
4189 // it's legal per the standard depending on how you read C99 6.7.5.3p15 and
4190 // C99 6.9.1p8.
4191 if (!getLangOpts().CPlusPlus &&
4192 Old->hasPrototype() && !New->hasPrototype() &&
4193 New->getType()->getAs<FunctionProtoType>() &&
4194 Old->getNumParams() == New->getNumParams()) {
4195 SmallVector<QualType, 16> ArgTypes;
4196 SmallVector<GNUCompatibleParamWarning, 16> Warnings;
4197 const FunctionProtoType *OldProto
4198 = Old->getType()->getAs<FunctionProtoType>();
4199 const FunctionProtoType *NewProto
4200 = New->getType()->getAs<FunctionProtoType>();
4201
4202 // Determine whether this is the GNU C extension.
4203 QualType MergedReturn = Context.mergeTypes(OldProto->getReturnType(),
4204 NewProto->getReturnType());
4205 bool LooseCompatible = !MergedReturn.isNull();
4206 for (unsigned Idx = 0, End = Old->getNumParams();
4207 LooseCompatible && Idx != End; ++Idx) {
4208 ParmVarDecl *OldParm = Old->getParamDecl(i: Idx);
4209 ParmVarDecl *NewParm = New->getParamDecl(i: Idx);
4210 if (Context.typesAreCompatible(T1: OldParm->getType(),
4211 T2: NewProto->getParamType(i: Idx))) {
4212 ArgTypes.push_back(Elt: NewParm->getType());
4213 } else if (Context.typesAreCompatible(T1: OldParm->getType(),
4214 T2: NewParm->getType(),
4215 /*CompareUnqualified=*/true)) {
4216 GNUCompatibleParamWarning Warn = { .OldParm: OldParm, .NewParm: NewParm,
4217 .PromotedType: NewProto->getParamType(i: Idx) };
4218 Warnings.push_back(Elt: Warn);
4219 ArgTypes.push_back(Elt: NewParm->getType());
4220 } else
4221 LooseCompatible = false;
4222 }
4223
4224 if (LooseCompatible) {
4225 for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) {
4226 Diag(Loc: Warnings[Warn].NewParm->getLocation(),
4227 DiagID: diag::ext_param_promoted_not_compatible_with_prototype)
4228 << Warnings[Warn].PromotedType
4229 << Warnings[Warn].OldParm->getType();
4230 if (Warnings[Warn].OldParm->getLocation().isValid())
4231 Diag(Loc: Warnings[Warn].OldParm->getLocation(),
4232 DiagID: diag::note_previous_declaration);
4233 }
4234
4235 if (MergeTypeWithOld)
4236 New->setType(Context.getFunctionType(ResultTy: MergedReturn, Args: ArgTypes,
4237 EPI: OldProto->getExtProtoInfo()));
4238 return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
4239 }
4240
4241 // Fall through to diagnose conflicting types.
4242 }
4243
4244 // A function that has already been declared has been redeclared or
4245 // defined with a different type; show an appropriate diagnostic.
4246
4247 // If the previous declaration was an implicitly-generated builtin
4248 // declaration, then at the very least we should use a specialized note.
4249 unsigned BuiltinID;
4250 if (Old->isImplicit() && (BuiltinID = Old->getBuiltinID())) {
4251 // If it's actually a library-defined builtin function like 'malloc'
4252 // or 'printf', just warn about the incompatible redeclaration.
4253 if (Context.BuiltinInfo.isPredefinedLibFunction(ID: BuiltinID)) {
4254 Diag(Loc: New->getLocation(), DiagID: diag::warn_redecl_library_builtin) << New;
4255 Diag(Loc: OldLocation, DiagID: diag::note_previous_builtin_declaration)
4256 << Old << Old->getType();
4257 return false;
4258 }
4259
4260 PrevDiag = diag::note_previous_builtin_declaration;
4261 }
4262
4263 Diag(Loc: New->getLocation(), DiagID: diag::err_conflicting_types) << New->getDeclName();
4264 Diag(Loc: OldLocation, DiagID: PrevDiag) << Old << Old->getType();
4265 return true;
4266}
4267
4268bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old,
4269 Scope *S, bool MergeTypeWithOld) {
4270 // Merge the attributes
4271 mergeDeclAttributes(New, Old);
4272
4273 // Merge "pure" flag.
4274 if (Old->isPureVirtual())
4275 New->setIsPureVirtual();
4276
4277 // Merge "used" flag.
4278 if (Old->getMostRecentDecl()->isUsed(CheckUsedAttr: false))
4279 New->setIsUsed();
4280
4281 // Merge attributes from the parameters. These can mismatch with K&R
4282 // declarations.
4283 if (New->getNumParams() == Old->getNumParams())
4284 for (unsigned i = 0, e = New->getNumParams(); i != e; ++i) {
4285 ParmVarDecl *NewParam = New->getParamDecl(i);
4286 ParmVarDecl *OldParam = Old->getParamDecl(i);
4287 mergeParamDeclAttributes(newDecl: NewParam, oldDecl: OldParam, S&: *this);
4288 mergeParamDeclTypes(NewParam, OldParam, S&: *this);
4289 }
4290
4291 if (getLangOpts().CPlusPlus)
4292 return MergeCXXFunctionDecl(New, Old, S);
4293
4294 // Merge the function types so the we get the composite types for the return
4295 // and argument types. Per C11 6.2.7/4, only update the type if the old decl
4296 // was visible.
4297 QualType Merged = Context.mergeTypes(Old->getType(), New->getType());
4298 if (!Merged.isNull() && MergeTypeWithOld)
4299 New->setType(Merged);
4300
4301 return false;
4302}
4303
4304void Sema::mergeObjCMethodDecls(ObjCMethodDecl *newMethod,
4305 ObjCMethodDecl *oldMethod) {
4306 // Merge the attributes, including deprecated/unavailable
4307 AvailabilityMergeKind MergeKind =
4308 isa<ObjCProtocolDecl>(Val: oldMethod->getDeclContext())
4309 ? (oldMethod->isOptional() ? AMK_OptionalProtocolImplementation
4310 : AMK_ProtocolImplementation)
4311 : isa<ObjCImplDecl>(Val: newMethod->getDeclContext()) ? AMK_Redeclaration
4312 : AMK_Override;
4313
4314 mergeDeclAttributes(New: newMethod, Old: oldMethod, AMK: MergeKind);
4315
4316 // Merge attributes from the parameters.
4317 ObjCMethodDecl::param_const_iterator oi = oldMethod->param_begin(),
4318 oe = oldMethod->param_end();
4319 for (ObjCMethodDecl::param_iterator
4320 ni = newMethod->param_begin(), ne = newMethod->param_end();
4321 ni != ne && oi != oe; ++ni, ++oi)
4322 mergeParamDeclAttributes(newDecl: *ni, oldDecl: *oi, S&: *this);
4323
4324 ObjC().CheckObjCMethodOverride(NewMethod: newMethod, Overridden: oldMethod);
4325}
4326
4327static void diagnoseVarDeclTypeMismatch(Sema &S, VarDecl *New, VarDecl* Old) {
4328 assert(!S.Context.hasSameType(New->getType(), Old->getType()));
4329
4330 S.Diag(Loc: New->getLocation(), DiagID: New->isThisDeclarationADefinition()
4331 ? diag::err_redefinition_different_type
4332 : diag::err_redeclaration_different_type)
4333 << New->getDeclName() << New->getType() << Old->getType();
4334
4335 diag::kind PrevDiag;
4336 SourceLocation OldLocation;
4337 std::tie(args&: PrevDiag, args&: OldLocation)
4338 = getNoteDiagForInvalidRedeclaration(Old, New);
4339 S.Diag(Loc: OldLocation, DiagID: PrevDiag) << Old << Old->getType();
4340 New->setInvalidDecl();
4341}
4342
4343void Sema::MergeVarDeclTypes(VarDecl *New, VarDecl *Old,
4344 bool MergeTypeWithOld) {
4345 if (New->isInvalidDecl() || Old->isInvalidDecl() || New->getType()->containsErrors() || Old->getType()->containsErrors())
4346 return;
4347
4348 QualType MergedT;
4349 if (getLangOpts().CPlusPlus) {
4350 if (New->getType()->isUndeducedType()) {
4351 // We don't know what the new type is until the initializer is attached.
4352 return;
4353 } else if (Context.hasSameType(T1: New->getType(), T2: Old->getType())) {
4354 // These could still be something that needs exception specs checked.
4355 return MergeVarDeclExceptionSpecs(New, Old);
4356 }
4357 // C++ [basic.link]p10:
4358 // [...] the types specified by all declarations referring to a given
4359 // object or function shall be identical, except that declarations for an
4360 // array object can specify array types that differ by the presence or
4361 // absence of a major array bound (8.3.4).
4362 else if (Old->getType()->isArrayType() && New->getType()->isArrayType()) {
4363 const ArrayType *OldArray = Context.getAsArrayType(T: Old->getType());
4364 const ArrayType *NewArray = Context.getAsArrayType(T: New->getType());
4365
4366 // We are merging a variable declaration New into Old. If it has an array
4367 // bound, and that bound differs from Old's bound, we should diagnose the
4368 // mismatch.
4369 if (!NewArray->isIncompleteArrayType() && !NewArray->isDependentType()) {
4370 for (VarDecl *PrevVD = Old->getMostRecentDecl(); PrevVD;
4371 PrevVD = PrevVD->getPreviousDecl()) {
4372 QualType PrevVDTy = PrevVD->getType();
4373 if (PrevVDTy->isIncompleteArrayType() || PrevVDTy->isDependentType())
4374 continue;
4375
4376 if (!Context.hasSameType(T1: New->getType(), T2: PrevVDTy))
4377 return diagnoseVarDeclTypeMismatch(S&: *this, New, Old: PrevVD);
4378 }
4379 }
4380
4381 if (OldArray->isIncompleteArrayType() && NewArray->isArrayType()) {
4382 if (Context.hasSameType(T1: OldArray->getElementType(),
4383 T2: NewArray->getElementType()))
4384 MergedT = New->getType();
4385 }
4386 // FIXME: Check visibility. New is hidden but has a complete type. If New
4387 // has no array bound, it should not inherit one from Old, if Old is not
4388 // visible.
4389 else if (OldArray->isArrayType() && NewArray->isIncompleteArrayType()) {
4390 if (Context.hasSameType(T1: OldArray->getElementType(),
4391 T2: NewArray->getElementType()))
4392 MergedT = Old->getType();
4393 }
4394 }
4395 else if (New->getType()->isObjCObjectPointerType() &&
4396 Old->getType()->isObjCObjectPointerType()) {
4397 MergedT = Context.mergeObjCGCQualifiers(New->getType(),
4398 Old->getType());
4399 }
4400 } else {
4401 // C 6.2.7p2:
4402 // All declarations that refer to the same object or function shall have
4403 // compatible type.
4404 MergedT = Context.mergeTypes(New->getType(), Old->getType());
4405 }
4406 if (MergedT.isNull()) {
4407 // It's OK if we couldn't merge types if either type is dependent, for a
4408 // block-scope variable. In other cases (static data members of class
4409 // templates, variable templates, ...), we require the types to be
4410 // equivalent.
4411 // FIXME: The C++ standard doesn't say anything about this.
4412 if ((New->getType()->isDependentType() ||
4413 Old->getType()->isDependentType()) && New->isLocalVarDecl()) {
4414 // If the old type was dependent, we can't merge with it, so the new type
4415 // becomes dependent for now. We'll reproduce the original type when we
4416 // instantiate the TypeSourceInfo for the variable.
4417 if (!New->getType()->isDependentType() && MergeTypeWithOld)
4418 New->setType(Context.DependentTy);
4419 return;
4420 }
4421 return diagnoseVarDeclTypeMismatch(S&: *this, New, Old);
4422 }
4423
4424 // Don't actually update the type on the new declaration if the old
4425 // declaration was an extern declaration in a different scope.
4426 if (MergeTypeWithOld)
4427 New->setType(MergedT);
4428}
4429
4430static bool mergeTypeWithPrevious(Sema &S, VarDecl *NewVD, VarDecl *OldVD,
4431 LookupResult &Previous) {
4432 // C11 6.2.7p4:
4433 // For an identifier with internal or external linkage declared
4434 // in a scope in which a prior declaration of that identifier is
4435 // visible, if the prior declaration specifies internal or
4436 // external linkage, the type of the identifier at the later
4437 // declaration becomes the composite type.
4438 //
4439 // If the variable isn't visible, we do not merge with its type.
4440 if (Previous.isShadowed())
4441 return false;
4442
4443 if (S.getLangOpts().CPlusPlus) {
4444 // C++11 [dcl.array]p3:
4445 // If there is a preceding declaration of the entity in the same
4446 // scope in which the bound was specified, an omitted array bound
4447 // is taken to be the same as in that earlier declaration.
4448 return NewVD->isPreviousDeclInSameBlockScope() ||
4449 (!OldVD->getLexicalDeclContext()->isFunctionOrMethod() &&
4450 !NewVD->getLexicalDeclContext()->isFunctionOrMethod());
4451 } else {
4452 // If the old declaration was function-local, don't merge with its
4453 // type unless we're in the same function.
4454 return !OldVD->getLexicalDeclContext()->isFunctionOrMethod() ||
4455 OldVD->getLexicalDeclContext() == NewVD->getLexicalDeclContext();
4456 }
4457}
4458
4459void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) {
4460 // If the new decl is already invalid, don't do any other checking.
4461 if (New->isInvalidDecl())
4462 return;
4463
4464 if (!shouldLinkPossiblyHiddenDecl(Old&: Previous, New))
4465 return;
4466
4467 VarTemplateDecl *NewTemplate = New->getDescribedVarTemplate();
4468
4469 // Verify the old decl was also a variable or variable template.
4470 VarDecl *Old = nullptr;
4471 VarTemplateDecl *OldTemplate = nullptr;
4472 if (Previous.isSingleResult()) {
4473 if (NewTemplate) {
4474 OldTemplate = dyn_cast<VarTemplateDecl>(Val: Previous.getFoundDecl());
4475 Old = OldTemplate ? OldTemplate->getTemplatedDecl() : nullptr;
4476
4477 if (auto *Shadow =
4478 dyn_cast<UsingShadowDecl>(Val: Previous.getRepresentativeDecl()))
4479 if (checkUsingShadowRedecl<VarTemplateDecl>(S&: *this, OldS: Shadow, New: NewTemplate))
4480 return New->setInvalidDecl();
4481 } else {
4482 Old = dyn_cast<VarDecl>(Val: Previous.getFoundDecl());
4483
4484 if (auto *Shadow =
4485 dyn_cast<UsingShadowDecl>(Val: Previous.getRepresentativeDecl()))
4486 if (checkUsingShadowRedecl<VarDecl>(S&: *this, OldS: Shadow, New))
4487 return New->setInvalidDecl();
4488 }
4489 }
4490 if (!Old) {
4491 Diag(Loc: New->getLocation(), DiagID: diag::err_redefinition_different_kind)
4492 << New->getDeclName();
4493 notePreviousDefinition(Old: Previous.getRepresentativeDecl(),
4494 New: New->getLocation());
4495 return New->setInvalidDecl();
4496 }
4497
4498 // If the old declaration was found in an inline namespace and the new
4499 // declaration was qualified, update the DeclContext to match.
4500 adjustDeclContextForDeclaratorDecl(NewD: New, OldD: Old);
4501
4502 // Ensure the template parameters are compatible.
4503 if (NewTemplate &&
4504 !TemplateParameterListsAreEqual(New: NewTemplate->getTemplateParameters(),
4505 Old: OldTemplate->getTemplateParameters(),
4506 /*Complain=*/true, Kind: TPL_TemplateMatch))
4507 return New->setInvalidDecl();
4508
4509 // C++ [class.mem]p1:
4510 // A member shall not be declared twice in the member-specification [...]
4511 //
4512 // Here, we need only consider static data members.
4513 if (Old->isStaticDataMember() && !New->isOutOfLine()) {
4514 Diag(Loc: New->getLocation(), DiagID: diag::err_duplicate_member)
4515 << New->getIdentifier();
4516 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_declaration);
4517 New->setInvalidDecl();
4518 }
4519
4520 mergeDeclAttributes(New, Old);
4521 // Warn if an already-defined variable is made a weak_import in a subsequent
4522 // declaration
4523 if (New->hasAttr<WeakImportAttr>())
4524 for (auto *D = Old; D; D = D->getPreviousDecl()) {
4525 if (D->isThisDeclarationADefinition() != VarDecl::DeclarationOnly) {
4526 Diag(Loc: New->getLocation(), DiagID: diag::warn_weak_import) << New->getDeclName();
4527 Diag(Loc: D->getLocation(), DiagID: diag::note_previous_definition);
4528 // Remove weak_import attribute on new declaration.
4529 New->dropAttr<WeakImportAttr>();
4530 break;
4531 }
4532 }
4533
4534 if (const auto *ILA = New->getAttr<InternalLinkageAttr>())
4535 if (!Old->hasAttr<InternalLinkageAttr>()) {
4536 Diag(Loc: New->getLocation(), DiagID: diag::err_attribute_missing_on_first_decl)
4537 << ILA;
4538 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_declaration);
4539 New->dropAttr<InternalLinkageAttr>();
4540 }
4541
4542 // Merge the types.
4543 VarDecl *MostRecent = Old->getMostRecentDecl();
4544 if (MostRecent != Old) {
4545 MergeVarDeclTypes(New, Old: MostRecent,
4546 MergeTypeWithOld: mergeTypeWithPrevious(S&: *this, NewVD: New, OldVD: MostRecent, Previous));
4547 if (New->isInvalidDecl())
4548 return;
4549 }
4550
4551 MergeVarDeclTypes(New, Old, MergeTypeWithOld: mergeTypeWithPrevious(S&: *this, NewVD: New, OldVD: Old, Previous));
4552 if (New->isInvalidDecl())
4553 return;
4554
4555 diag::kind PrevDiag;
4556 SourceLocation OldLocation;
4557 std::tie(args&: PrevDiag, args&: OldLocation) =
4558 getNoteDiagForInvalidRedeclaration(Old, New);
4559
4560 // [dcl.stc]p8: Check if we have a non-static decl followed by a static.
4561 if (New->getStorageClass() == SC_Static &&
4562 !New->isStaticDataMember() &&
4563 Old->hasExternalFormalLinkage()) {
4564 if (getLangOpts().MicrosoftExt) {
4565 Diag(Loc: New->getLocation(), DiagID: diag::ext_static_non_static)
4566 << New->getDeclName();
4567 Diag(Loc: OldLocation, DiagID: PrevDiag);
4568 } else {
4569 Diag(Loc: New->getLocation(), DiagID: diag::err_static_non_static)
4570 << New->getDeclName();
4571 Diag(Loc: OldLocation, DiagID: PrevDiag);
4572 return New->setInvalidDecl();
4573 }
4574 }
4575 // C99 6.2.2p4:
4576 // For an identifier declared with the storage-class specifier
4577 // extern in a scope in which a prior declaration of that
4578 // identifier is visible,23) if the prior declaration specifies
4579 // internal or external linkage, the linkage of the identifier at
4580 // the later declaration is the same as the linkage specified at
4581 // the prior declaration. If no prior declaration is visible, or
4582 // if the prior declaration specifies no linkage, then the
4583 // identifier has external linkage.
4584 if (New->hasExternalStorage() && Old->hasLinkage())
4585 /* Okay */;
4586 else if (New->getCanonicalDecl()->getStorageClass() != SC_Static &&
4587 !New->isStaticDataMember() &&
4588 Old->getCanonicalDecl()->getStorageClass() == SC_Static) {
4589 Diag(Loc: New->getLocation(), DiagID: diag::err_non_static_static) << New->getDeclName();
4590 Diag(Loc: OldLocation, DiagID: PrevDiag);
4591 return New->setInvalidDecl();
4592 }
4593
4594 // Check if extern is followed by non-extern and vice-versa.
4595 if (New->hasExternalStorage() &&
4596 !Old->hasLinkage() && Old->isLocalVarDeclOrParm()) {
4597 Diag(Loc: New->getLocation(), DiagID: diag::err_extern_non_extern) << New->getDeclName();
4598 Diag(Loc: OldLocation, DiagID: PrevDiag);
4599 return New->setInvalidDecl();
4600 }
4601 if (Old->hasLinkage() && New->isLocalVarDeclOrParm() &&
4602 !New->hasExternalStorage()) {
4603 Diag(Loc: New->getLocation(), DiagID: diag::err_non_extern_extern) << New->getDeclName();
4604 Diag(Loc: OldLocation, DiagID: PrevDiag);
4605 return New->setInvalidDecl();
4606 }
4607
4608 if (CheckRedeclarationInModule(New, Old))
4609 return;
4610
4611 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup.
4612
4613 // FIXME: The test for external storage here seems wrong? We still
4614 // need to check for mismatches.
4615 if (!New->hasExternalStorage() && !New->isFileVarDecl() &&
4616 // Don't complain about out-of-line definitions of static members.
4617 !(Old->getLexicalDeclContext()->isRecord() &&
4618 !New->getLexicalDeclContext()->isRecord())) {
4619 Diag(Loc: New->getLocation(), DiagID: diag::err_redefinition) << New->getDeclName();
4620 Diag(Loc: OldLocation, DiagID: PrevDiag);
4621 return New->setInvalidDecl();
4622 }
4623
4624 if (New->isInline() && !Old->getMostRecentDecl()->isInline()) {
4625 if (VarDecl *Def = Old->getDefinition()) {
4626 // C++1z [dcl.fcn.spec]p4:
4627 // If the definition of a variable appears in a translation unit before
4628 // its first declaration as inline, the program is ill-formed.
4629 Diag(Loc: New->getLocation(), DiagID: diag::err_inline_decl_follows_def) << New;
4630 Diag(Loc: Def->getLocation(), DiagID: diag::note_previous_definition);
4631 }
4632 }
4633
4634 // If this redeclaration makes the variable inline, we may need to add it to
4635 // UndefinedButUsed.
4636 if (!Old->isInline() && New->isInline() && Old->isUsed(CheckUsedAttr: false) &&
4637 !Old->getDefinition() && !New->isThisDeclarationADefinition())
4638 UndefinedButUsed.insert(KV: std::make_pair(x: Old->getCanonicalDecl(),
4639 y: SourceLocation()));
4640
4641 if (New->getTLSKind() != Old->getTLSKind()) {
4642 if (!Old->getTLSKind()) {
4643 Diag(Loc: New->getLocation(), DiagID: diag::err_thread_non_thread) << New->getDeclName();
4644 Diag(Loc: OldLocation, DiagID: PrevDiag);
4645 } else if (!New->getTLSKind()) {
4646 Diag(Loc: New->getLocation(), DiagID: diag::err_non_thread_thread) << New->getDeclName();
4647 Diag(Loc: OldLocation, DiagID: PrevDiag);
4648 } else {
4649 // Do not allow redeclaration to change the variable between requiring
4650 // static and dynamic initialization.
4651 // FIXME: GCC allows this, but uses the TLS keyword on the first
4652 // declaration to determine the kind. Do we need to be compatible here?
4653 Diag(Loc: New->getLocation(), DiagID: diag::err_thread_thread_different_kind)
4654 << New->getDeclName() << (New->getTLSKind() == VarDecl::TLS_Dynamic);
4655 Diag(Loc: OldLocation, DiagID: PrevDiag);
4656 }
4657 }
4658
4659 // C++ doesn't have tentative definitions, so go right ahead and check here.
4660 if (getLangOpts().CPlusPlus) {
4661 if (Old->isStaticDataMember() && Old->getCanonicalDecl()->isInline() &&
4662 Old->getCanonicalDecl()->isConstexpr()) {
4663 // This definition won't be a definition any more once it's been merged.
4664 Diag(Loc: New->getLocation(),
4665 DiagID: diag::warn_deprecated_redundant_constexpr_static_def);
4666 } else if (New->isThisDeclarationADefinition() == VarDecl::Definition) {
4667 VarDecl *Def = Old->getDefinition();
4668 if (Def && checkVarDeclRedefinition(OldDefn: Def, NewDefn: New))
4669 return;
4670 }
4671 }
4672
4673 if (haveIncompatibleLanguageLinkages(Old, New)) {
4674 Diag(Loc: New->getLocation(), DiagID: diag::err_different_language_linkage) << New;
4675 Diag(Loc: OldLocation, DiagID: PrevDiag);
4676 New->setInvalidDecl();
4677 return;
4678 }
4679
4680 // Merge "used" flag.
4681 if (Old->getMostRecentDecl()->isUsed(CheckUsedAttr: false))
4682 New->setIsUsed();
4683
4684 // Keep a chain of previous declarations.
4685 New->setPreviousDecl(Old);
4686 if (NewTemplate)
4687 NewTemplate->setPreviousDecl(OldTemplate);
4688
4689 // Inherit access appropriately.
4690 New->setAccess(Old->getAccess());
4691 if (NewTemplate)
4692 NewTemplate->setAccess(New->getAccess());
4693
4694 if (Old->isInline())
4695 New->setImplicitlyInline();
4696}
4697
4698void Sema::notePreviousDefinition(const NamedDecl *Old, SourceLocation New) {
4699 SourceManager &SrcMgr = getSourceManager();
4700 auto FNewDecLoc = SrcMgr.getDecomposedLoc(Loc: New);
4701 auto FOldDecLoc = SrcMgr.getDecomposedLoc(Loc: Old->getLocation());
4702 auto *FNew = SrcMgr.getFileEntryForID(FID: FNewDecLoc.first);
4703 auto FOld = SrcMgr.getFileEntryRefForID(FID: FOldDecLoc.first);
4704 auto &HSI = PP.getHeaderSearchInfo();
4705 StringRef HdrFilename =
4706 SrcMgr.getFilename(SpellingLoc: SrcMgr.getSpellingLoc(Loc: Old->getLocation()));
4707
4708 auto noteFromModuleOrInclude = [&](Module *Mod,
4709 SourceLocation IncLoc) -> bool {
4710 // Redefinition errors with modules are common with non modular mapped
4711 // headers, example: a non-modular header H in module A that also gets
4712 // included directly in a TU. Pointing twice to the same header/definition
4713 // is confusing, try to get better diagnostics when modules is on.
4714 if (IncLoc.isValid()) {
4715 if (Mod) {
4716 Diag(Loc: IncLoc, DiagID: diag::note_redefinition_modules_same_file)
4717 << HdrFilename.str() << Mod->getFullModuleName();
4718 if (!Mod->DefinitionLoc.isInvalid())
4719 Diag(Loc: Mod->DefinitionLoc, DiagID: diag::note_defined_here)
4720 << Mod->getFullModuleName();
4721 } else {
4722 Diag(Loc: IncLoc, DiagID: diag::note_redefinition_include_same_file)
4723 << HdrFilename.str();
4724 }
4725 return true;
4726 }
4727
4728 return false;
4729 };
4730
4731 // Is it the same file and same offset? Provide more information on why
4732 // this leads to a redefinition error.
4733 if (FNew == FOld && FNewDecLoc.second == FOldDecLoc.second) {
4734 SourceLocation OldIncLoc = SrcMgr.getIncludeLoc(FID: FOldDecLoc.first);
4735 SourceLocation NewIncLoc = SrcMgr.getIncludeLoc(FID: FNewDecLoc.first);
4736 bool EmittedDiag =
4737 noteFromModuleOrInclude(Old->getOwningModule(), OldIncLoc);
4738 EmittedDiag |= noteFromModuleOrInclude(getCurrentModule(), NewIncLoc);
4739
4740 // If the header has no guards, emit a note suggesting one.
4741 if (FOld && !HSI.isFileMultipleIncludeGuarded(File: *FOld))
4742 Diag(Loc: Old->getLocation(), DiagID: diag::note_use_ifdef_guards);
4743
4744 if (EmittedDiag)
4745 return;
4746 }
4747
4748 // Redefinition coming from different files or couldn't do better above.
4749 if (Old->getLocation().isValid())
4750 Diag(Loc: Old->getLocation(), DiagID: diag::note_previous_definition);
4751}
4752
4753bool Sema::checkVarDeclRedefinition(VarDecl *Old, VarDecl *New) {
4754 if (!hasVisibleDefinition(D: Old) &&
4755 (New->getFormalLinkage() == Linkage::Internal || New->isInline() ||
4756 isa<VarTemplateSpecializationDecl>(Val: New) ||
4757 New->getDescribedVarTemplate() || New->getNumTemplateParameterLists() ||
4758 New->getDeclContext()->isDependentContext())) {
4759 // The previous definition is hidden, and multiple definitions are
4760 // permitted (in separate TUs). Demote this to a declaration.
4761 New->demoteThisDefinitionToDeclaration();
4762
4763 // Make the canonical definition visible.
4764 if (auto *OldTD = Old->getDescribedVarTemplate())
4765 makeMergedDefinitionVisible(ND: OldTD);
4766 makeMergedDefinitionVisible(ND: Old);
4767 return false;
4768 } else {
4769 Diag(Loc: New->getLocation(), DiagID: diag::err_redefinition) << New;
4770 notePreviousDefinition(Old, New: New->getLocation());
4771 New->setInvalidDecl();
4772 return true;
4773 }
4774}
4775
4776Decl *Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
4777 DeclSpec &DS,
4778 const ParsedAttributesView &DeclAttrs,
4779 RecordDecl *&AnonRecord) {
4780 return ParsedFreeStandingDeclSpec(
4781 S, AS, DS, DeclAttrs, TemplateParams: MultiTemplateParamsArg(), IsExplicitInstantiation: false, AnonRecord);
4782}
4783
4784// The MS ABI changed between VS2013 and VS2015 with regard to numbers used to
4785// disambiguate entities defined in different scopes.
4786// While the VS2015 ABI fixes potential miscompiles, it is also breaks
4787// compatibility.
4788// We will pick our mangling number depending on which version of MSVC is being
4789// targeted.
4790static unsigned getMSManglingNumber(const LangOptions &LO, Scope *S) {
4791 return LO.isCompatibleWithMSVC(MajorVersion: LangOptions::MSVC2015)
4792 ? S->getMSCurManglingNumber()
4793 : S->getMSLastManglingNumber();
4794}
4795
4796void Sema::handleTagNumbering(const TagDecl *Tag, Scope *TagScope) {
4797 if (!Context.getLangOpts().CPlusPlus)
4798 return;
4799
4800 if (isa<CXXRecordDecl>(Val: Tag->getParent())) {
4801 // If this tag is the direct child of a class, number it if
4802 // it is anonymous.
4803 if (!Tag->getName().empty() || Tag->getTypedefNameForAnonDecl())
4804 return;
4805 MangleNumberingContext &MCtx =
4806 Context.getManglingNumberContext(DC: Tag->getParent());
4807 Context.setManglingNumber(
4808 ND: Tag, Number: MCtx.getManglingNumber(
4809 TD: Tag, MSLocalManglingNumber: getMSManglingNumber(LO: getLangOpts(), S: TagScope)));
4810 return;
4811 }
4812
4813 // If this tag isn't a direct child of a class, number it if it is local.
4814 MangleNumberingContext *MCtx;
4815 Decl *ManglingContextDecl;
4816 std::tie(args&: MCtx, args&: ManglingContextDecl) =
4817 getCurrentMangleNumberContext(DC: Tag->getDeclContext());
4818 if (MCtx) {
4819 Context.setManglingNumber(
4820 ND: Tag, Number: MCtx->getManglingNumber(
4821 TD: Tag, MSLocalManglingNumber: getMSManglingNumber(LO: getLangOpts(), S: TagScope)));
4822 }
4823}
4824
4825namespace {
4826struct NonCLikeKind {
4827 enum {
4828 None,
4829 BaseClass,
4830 DefaultMemberInit,
4831 Lambda,
4832 Friend,
4833 OtherMember,
4834 Invalid,
4835 } Kind = None;
4836 SourceRange Range;
4837
4838 explicit operator bool() { return Kind != None; }
4839};
4840}
4841
4842/// Determine whether a class is C-like, according to the rules of C++
4843/// [dcl.typedef] for anonymous classes with typedef names for linkage.
4844static NonCLikeKind getNonCLikeKindForAnonymousStruct(const CXXRecordDecl *RD) {
4845 if (RD->isInvalidDecl())
4846 return {.Kind: NonCLikeKind::Invalid, .Range: {}};
4847
4848 // C++ [dcl.typedef]p9: [P1766R1]
4849 // An unnamed class with a typedef name for linkage purposes shall not
4850 //
4851 // -- have any base classes
4852 if (RD->getNumBases())
4853 return {.Kind: NonCLikeKind::BaseClass,
4854 .Range: SourceRange(RD->bases_begin()->getBeginLoc(),
4855 RD->bases_end()[-1].getEndLoc())};
4856 bool Invalid = false;
4857 for (Decl *D : RD->decls()) {
4858 // Don't complain about things we already diagnosed.
4859 if (D->isInvalidDecl()) {
4860 Invalid = true;
4861 continue;
4862 }
4863
4864 // -- have any [...] default member initializers
4865 if (auto *FD = dyn_cast<FieldDecl>(Val: D)) {
4866 if (FD->hasInClassInitializer()) {
4867 auto *Init = FD->getInClassInitializer();
4868 return {.Kind: NonCLikeKind::DefaultMemberInit,
4869 .Range: Init ? Init->getSourceRange() : D->getSourceRange()};
4870 }
4871 continue;
4872 }
4873
4874 // FIXME: We don't allow friend declarations. This violates the wording of
4875 // P1766, but not the intent.
4876 if (isa<FriendDecl>(Val: D))
4877 return {.Kind: NonCLikeKind::Friend, .Range: D->getSourceRange()};
4878
4879 // -- declare any members other than non-static data members, member
4880 // enumerations, or member classes,
4881 if (isa<StaticAssertDecl>(Val: D) || isa<IndirectFieldDecl>(Val: D) ||
4882 isa<EnumDecl>(Val: D))
4883 continue;
4884 auto *MemberRD = dyn_cast<CXXRecordDecl>(Val: D);
4885 if (!MemberRD) {
4886 if (D->isImplicit())
4887 continue;
4888 return {.Kind: NonCLikeKind::OtherMember, .Range: D->getSourceRange()};
4889 }
4890
4891 // -- contain a lambda-expression,
4892 if (MemberRD->isLambda())
4893 return {.Kind: NonCLikeKind::Lambda, .Range: MemberRD->getSourceRange()};
4894
4895 // and all member classes shall also satisfy these requirements
4896 // (recursively).
4897 if (MemberRD->isThisDeclarationADefinition()) {
4898 if (auto Kind = getNonCLikeKindForAnonymousStruct(RD: MemberRD))
4899 return Kind;
4900 }
4901 }
4902
4903 return {.Kind: Invalid ? NonCLikeKind::Invalid : NonCLikeKind::None, .Range: {}};
4904}
4905
4906void Sema::setTagNameForLinkagePurposes(TagDecl *TagFromDeclSpec,
4907 TypedefNameDecl *NewTD) {
4908 if (TagFromDeclSpec->isInvalidDecl())
4909 return;
4910
4911 // Do nothing if the tag already has a name for linkage purposes.
4912 if (TagFromDeclSpec->hasNameForLinkage())
4913 return;
4914
4915 // A well-formed anonymous tag must always be a TagUseKind::Definition.
4916 assert(TagFromDeclSpec->isThisDeclarationADefinition());
4917
4918 // The type must match the tag exactly; no qualifiers allowed.
4919 if (!Context.hasSameType(T1: NewTD->getUnderlyingType(),
4920 T2: Context.getTagDeclType(Decl: TagFromDeclSpec))) {
4921 if (getLangOpts().CPlusPlus)
4922 Context.addTypedefNameForUnnamedTagDecl(TD: TagFromDeclSpec, TND: NewTD);
4923 return;
4924 }
4925
4926 // C++ [dcl.typedef]p9: [P1766R1, applied as DR]
4927 // An unnamed class with a typedef name for linkage purposes shall [be
4928 // C-like].
4929 //
4930 // FIXME: Also diagnose if we've already computed the linkage. That ideally
4931 // shouldn't happen, but there are constructs that the language rule doesn't
4932 // disallow for which we can't reasonably avoid computing linkage early.
4933 const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Val: TagFromDeclSpec);
4934 NonCLikeKind NonCLike = RD ? getNonCLikeKindForAnonymousStruct(RD)
4935 : NonCLikeKind();
4936 bool ChangesLinkage = TagFromDeclSpec->hasLinkageBeenComputed();
4937 if (NonCLike || ChangesLinkage) {
4938 if (NonCLike.Kind == NonCLikeKind::Invalid)
4939 return;
4940
4941 unsigned DiagID = diag::ext_non_c_like_anon_struct_in_typedef;
4942 if (ChangesLinkage) {
4943 // If the linkage changes, we can't accept this as an extension.
4944 if (NonCLike.Kind == NonCLikeKind::None)
4945 DiagID = diag::err_typedef_changes_linkage;
4946 else
4947 DiagID = diag::err_non_c_like_anon_struct_in_typedef;
4948 }
4949
4950 SourceLocation FixitLoc =
4951 getLocForEndOfToken(Loc: TagFromDeclSpec->getInnerLocStart());
4952 llvm::SmallString<40> TextToInsert;
4953 TextToInsert += ' ';
4954 TextToInsert += NewTD->getIdentifier()->getName();
4955
4956 Diag(Loc: FixitLoc, DiagID)
4957 << isa<TypeAliasDecl>(Val: NewTD)
4958 << FixItHint::CreateInsertion(InsertionLoc: FixitLoc, Code: TextToInsert);
4959 if (NonCLike.Kind != NonCLikeKind::None) {
4960 Diag(Loc: NonCLike.Range.getBegin(), DiagID: diag::note_non_c_like_anon_struct)
4961 << NonCLike.Kind - 1 << NonCLike.Range;
4962 }
4963 Diag(Loc: NewTD->getLocation(), DiagID: diag::note_typedef_for_linkage_here)
4964 << NewTD << isa<TypeAliasDecl>(Val: NewTD);
4965
4966 if (ChangesLinkage)
4967 return;
4968 }
4969
4970 // Otherwise, set this as the anon-decl typedef for the tag.
4971 TagFromDeclSpec->setTypedefNameForAnonDecl(NewTD);
4972}
4973
4974static unsigned GetDiagnosticTypeSpecifierID(const DeclSpec &DS) {
4975 DeclSpec::TST T = DS.getTypeSpecType();
4976 switch (T) {
4977 case DeclSpec::TST_class:
4978 return 0;
4979 case DeclSpec::TST_struct:
4980 return 1;
4981 case DeclSpec::TST_interface:
4982 return 2;
4983 case DeclSpec::TST_union:
4984 return 3;
4985 case DeclSpec::TST_enum:
4986 if (const auto *ED = dyn_cast<EnumDecl>(Val: DS.getRepAsDecl())) {
4987 if (ED->isScopedUsingClassTag())
4988 return 5;
4989 if (ED->isScoped())
4990 return 6;
4991 }
4992 return 4;
4993 default:
4994 llvm_unreachable("unexpected type specifier");
4995 }
4996}
4997
4998Decl *Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS,
4999 DeclSpec &DS,
5000 const ParsedAttributesView &DeclAttrs,
5001 MultiTemplateParamsArg TemplateParams,
5002 bool IsExplicitInstantiation,
5003 RecordDecl *&AnonRecord) {
5004 Decl *TagD = nullptr;
5005 TagDecl *Tag = nullptr;
5006 if (DS.getTypeSpecType() == DeclSpec::TST_class ||
5007 DS.getTypeSpecType() == DeclSpec::TST_struct ||
5008 DS.getTypeSpecType() == DeclSpec::TST_interface ||
5009 DS.getTypeSpecType() == DeclSpec::TST_union ||
5010 DS.getTypeSpecType() == DeclSpec::TST_enum) {
5011 TagD = DS.getRepAsDecl();
5012
5013 if (!TagD) // We probably had an error
5014 return nullptr;
5015
5016 // Note that the above type specs guarantee that the
5017 // type rep is a Decl, whereas in many of the others
5018 // it's a Type.
5019 if (isa<TagDecl>(Val: TagD))
5020 Tag = cast<TagDecl>(Val: TagD);
5021 else if (ClassTemplateDecl *CTD = dyn_cast<ClassTemplateDecl>(Val: TagD))
5022 Tag = CTD->getTemplatedDecl();
5023 }
5024
5025 if (Tag) {
5026 handleTagNumbering(Tag, TagScope: S);
5027 Tag->setFreeStanding();
5028 if (Tag->isInvalidDecl())
5029 return Tag;
5030 }
5031
5032 if (unsigned TypeQuals = DS.getTypeQualifiers()) {
5033 // Enforce C99 6.7.3p2: "Types other than pointer types derived from object
5034 // or incomplete types shall not be restrict-qualified."
5035 if (TypeQuals & DeclSpec::TQ_restrict)
5036 Diag(Loc: DS.getRestrictSpecLoc(),
5037 DiagID: diag::err_typecheck_invalid_restrict_not_pointer_noarg)
5038 << DS.getSourceRange();
5039 }
5040
5041 if (DS.isInlineSpecified())
5042 Diag(Loc: DS.getInlineSpecLoc(), DiagID: diag::err_inline_non_function)
5043 << getLangOpts().CPlusPlus17;
5044
5045 if (DS.hasConstexprSpecifier()) {
5046 // C++0x [dcl.constexpr]p1: constexpr can only be applied to declarations
5047 // and definitions of functions and variables.
5048 // C++2a [dcl.constexpr]p1: The consteval specifier shall be applied only to
5049 // the declaration of a function or function template
5050 if (Tag)
5051 Diag(Loc: DS.getConstexprSpecLoc(), DiagID: diag::err_constexpr_tag)
5052 << GetDiagnosticTypeSpecifierID(DS)
5053 << static_cast<int>(DS.getConstexprSpecifier());
5054 else if (getLangOpts().C23)
5055 Diag(Loc: DS.getConstexprSpecLoc(), DiagID: diag::err_c23_constexpr_not_variable);
5056 else
5057 Diag(Loc: DS.getConstexprSpecLoc(), DiagID: diag::err_constexpr_wrong_decl_kind)
5058 << static_cast<int>(DS.getConstexprSpecifier());
5059 // Don't emit warnings after this error.
5060 return TagD;
5061 }
5062
5063 DiagnoseFunctionSpecifiers(DS);
5064
5065 if (DS.isFriendSpecified()) {
5066 // If we're dealing with a decl but not a TagDecl, assume that
5067 // whatever routines created it handled the friendship aspect.
5068 if (TagD && !Tag)
5069 return nullptr;
5070 return ActOnFriendTypeDecl(S, DS, TemplateParams);
5071 }
5072
5073 // Track whether this decl-specifier declares anything.
5074 bool DeclaresAnything = true;
5075
5076 // Handle anonymous struct definitions.
5077 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Val: Tag)) {
5078 if (!Record->getDeclName() && Record->isCompleteDefinition() &&
5079 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) {
5080 if (getLangOpts().CPlusPlus ||
5081 Record->getDeclContext()->isRecord()) {
5082 // If CurContext is a DeclContext that can contain statements,
5083 // RecursiveASTVisitor won't visit the decls that
5084 // BuildAnonymousStructOrUnion() will put into CurContext.
5085 // Also store them here so that they can be part of the
5086 // DeclStmt that gets created in this case.
5087 // FIXME: Also return the IndirectFieldDecls created by
5088 // BuildAnonymousStructOr union, for the same reason?
5089 if (CurContext->isFunctionOrMethod())
5090 AnonRecord = Record;
5091 return BuildAnonymousStructOrUnion(S, DS, AS, Record,
5092 Policy: Context.getPrintingPolicy());
5093 }
5094
5095 DeclaresAnything = false;
5096 }
5097 }
5098
5099 // C11 6.7.2.1p2:
5100 // A struct-declaration that does not declare an anonymous structure or
5101 // anonymous union shall contain a struct-declarator-list.
5102 //
5103 // This rule also existed in C89 and C99; the grammar for struct-declaration
5104 // did not permit a struct-declaration without a struct-declarator-list.
5105 if (!getLangOpts().CPlusPlus && CurContext->isRecord() &&
5106 DS.getStorageClassSpec() == DeclSpec::SCS_unspecified) {
5107 // Check for Microsoft C extension: anonymous struct/union member.
5108 // Handle 2 kinds of anonymous struct/union:
5109 // struct STRUCT;
5110 // union UNION;
5111 // and
5112 // STRUCT_TYPE; <- where STRUCT_TYPE is a typedef struct.
5113 // UNION_TYPE; <- where UNION_TYPE is a typedef union.
5114 if ((Tag && Tag->getDeclName()) ||
5115 DS.getTypeSpecType() == DeclSpec::TST_typename) {
5116 RecordDecl *Record = nullptr;
5117 if (Tag)
5118 Record = dyn_cast<RecordDecl>(Val: Tag);
5119 else if (const RecordType *RT =
5120 DS.getRepAsType().get()->getAsStructureType())
5121 Record = RT->getDecl();
5122 else if (const RecordType *UT = DS.getRepAsType().get()->getAsUnionType())
5123 Record = UT->getDecl();
5124
5125 if (Record && getLangOpts().MicrosoftExt) {
5126 Diag(Loc: DS.getBeginLoc(), DiagID: diag::ext_ms_anonymous_record)
5127 << Record->isUnion() << DS.getSourceRange();
5128 return BuildMicrosoftCAnonymousStruct(S, DS, Record);
5129 }
5130
5131 DeclaresAnything = false;
5132 }
5133 }
5134
5135 // Skip all the checks below if we have a type error.
5136 if (DS.getTypeSpecType() == DeclSpec::TST_error ||
5137 (TagD && TagD->isInvalidDecl()))
5138 return TagD;
5139
5140 if (getLangOpts().CPlusPlus &&
5141 DS.getStorageClassSpec() != DeclSpec::SCS_typedef)
5142 if (EnumDecl *Enum = dyn_cast_or_null<EnumDecl>(Val: Tag))
5143 if (Enum->enumerator_begin() == Enum->enumerator_end() &&
5144 !Enum->getIdentifier() && !Enum->isInvalidDecl())
5145 DeclaresAnything = false;
5146
5147 if (!DS.isMissingDeclaratorOk()) {
5148 // Customize diagnostic for a typedef missing a name.
5149 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
5150 Diag(Loc: DS.getBeginLoc(), DiagID: diag::ext_typedef_without_a_name)
5151 << DS.getSourceRange();
5152 else
5153 DeclaresAnything = false;
5154 }
5155
5156 if (DS.isModulePrivateSpecified() &&
5157 Tag && Tag->getDeclContext()->isFunctionOrMethod())
5158 Diag(Loc: DS.getModulePrivateSpecLoc(), DiagID: diag::err_module_private_local_class)
5159 << llvm::to_underlying(E: Tag->getTagKind())
5160 << FixItHint::CreateRemoval(RemoveRange: DS.getModulePrivateSpecLoc());
5161
5162 ActOnDocumentableDecl(D: TagD);
5163
5164 // C 6.7/2:
5165 // A declaration [...] shall declare at least a declarator [...], a tag,
5166 // or the members of an enumeration.
5167 // C++ [dcl.dcl]p3:
5168 // [If there are no declarators], and except for the declaration of an
5169 // unnamed bit-field, the decl-specifier-seq shall introduce one or more
5170 // names into the program, or shall redeclare a name introduced by a
5171 // previous declaration.
5172 if (!DeclaresAnything) {
5173 // In C, we allow this as a (popular) extension / bug. Don't bother
5174 // producing further diagnostics for redundant qualifiers after this.
5175 Diag(Loc: DS.getBeginLoc(), DiagID: (IsExplicitInstantiation || !TemplateParams.empty())
5176 ? diag::err_no_declarators
5177 : diag::ext_no_declarators)
5178 << DS.getSourceRange();
5179 return TagD;
5180 }
5181
5182 // C++ [dcl.stc]p1:
5183 // If a storage-class-specifier appears in a decl-specifier-seq, [...] the
5184 // init-declarator-list of the declaration shall not be empty.
5185 // C++ [dcl.fct.spec]p1:
5186 // If a cv-qualifier appears in a decl-specifier-seq, the
5187 // init-declarator-list of the declaration shall not be empty.
5188 //
5189 // Spurious qualifiers here appear to be valid in C.
5190 unsigned DiagID = diag::warn_standalone_specifier;
5191 if (getLangOpts().CPlusPlus)
5192 DiagID = diag::ext_standalone_specifier;
5193
5194 // Note that a linkage-specification sets a storage class, but
5195 // 'extern "C" struct foo;' is actually valid and not theoretically
5196 // useless.
5197 if (DeclSpec::SCS SCS = DS.getStorageClassSpec()) {
5198 if (SCS == DeclSpec::SCS_mutable)
5199 // Since mutable is not a viable storage class specifier in C, there is
5200 // no reason to treat it as an extension. Instead, diagnose as an error.
5201 Diag(Loc: DS.getStorageClassSpecLoc(), DiagID: diag::err_mutable_nonmember);
5202 else if (!DS.isExternInLinkageSpec() && SCS != DeclSpec::SCS_typedef)
5203 Diag(Loc: DS.getStorageClassSpecLoc(), DiagID)
5204 << DeclSpec::getSpecifierName(S: SCS);
5205 }
5206
5207 if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec())
5208 Diag(Loc: DS.getThreadStorageClassSpecLoc(), DiagID)
5209 << DeclSpec::getSpecifierName(S: TSCS);
5210 if (DS.getTypeQualifiers()) {
5211 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
5212 Diag(Loc: DS.getConstSpecLoc(), DiagID) << "const";
5213 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
5214 Diag(Loc: DS.getConstSpecLoc(), DiagID) << "volatile";
5215 // Restrict is covered above.
5216 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
5217 Diag(Loc: DS.getAtomicSpecLoc(), DiagID) << "_Atomic";
5218 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
5219 Diag(Loc: DS.getUnalignedSpecLoc(), DiagID) << "__unaligned";
5220 }
5221
5222 // Warn about ignored type attributes, for example:
5223 // __attribute__((aligned)) struct A;
5224 // Attributes should be placed after tag to apply to type declaration.
5225 if (!DS.getAttributes().empty() || !DeclAttrs.empty()) {
5226 DeclSpec::TST TypeSpecType = DS.getTypeSpecType();
5227 if (TypeSpecType == DeclSpec::TST_class ||
5228 TypeSpecType == DeclSpec::TST_struct ||
5229 TypeSpecType == DeclSpec::TST_interface ||
5230 TypeSpecType == DeclSpec::TST_union ||
5231 TypeSpecType == DeclSpec::TST_enum) {
5232
5233 auto EmitAttributeDiagnostic = [this, &DS](const ParsedAttr &AL) {
5234 unsigned DiagnosticId = diag::warn_declspec_attribute_ignored;
5235 if (AL.isAlignas() && !getLangOpts().CPlusPlus)
5236 DiagnosticId = diag::warn_attribute_ignored;
5237 else if (AL.isRegularKeywordAttribute())
5238 DiagnosticId = diag::err_declspec_keyword_has_no_effect;
5239 else
5240 DiagnosticId = diag::warn_declspec_attribute_ignored;
5241 Diag(Loc: AL.getLoc(), DiagID: DiagnosticId)
5242 << AL << GetDiagnosticTypeSpecifierID(DS);
5243 };
5244
5245 llvm::for_each(Range&: DS.getAttributes(), F: EmitAttributeDiagnostic);
5246 llvm::for_each(Range: DeclAttrs, F: EmitAttributeDiagnostic);
5247 }
5248 }
5249
5250 return TagD;
5251}
5252
5253/// We are trying to inject an anonymous member into the given scope;
5254/// check if there's an existing declaration that can't be overloaded.
5255///
5256/// \return true if this is a forbidden redeclaration
5257static bool CheckAnonMemberRedeclaration(Sema &SemaRef, Scope *S,
5258 DeclContext *Owner,
5259 DeclarationName Name,
5260 SourceLocation NameLoc, bool IsUnion,
5261 StorageClass SC) {
5262 LookupResult R(SemaRef, Name, NameLoc,
5263 Owner->isRecord() ? Sema::LookupMemberName
5264 : Sema::LookupOrdinaryName,
5265 RedeclarationKind::ForVisibleRedeclaration);
5266 if (!SemaRef.LookupName(R, S)) return false;
5267
5268 // Pick a representative declaration.
5269 NamedDecl *PrevDecl = R.getRepresentativeDecl()->getUnderlyingDecl();
5270 assert(PrevDecl && "Expected a non-null Decl");
5271
5272 if (!SemaRef.isDeclInScope(D: PrevDecl, Ctx: Owner, S))
5273 return false;
5274
5275 if (SC == StorageClass::SC_None &&
5276 PrevDecl->isPlaceholderVar(LangOpts: SemaRef.getLangOpts()) &&
5277 (Owner->isFunctionOrMethod() || Owner->isRecord())) {
5278 if (!Owner->isRecord())
5279 SemaRef.DiagPlaceholderVariableDefinition(Loc: NameLoc);
5280 return false;
5281 }
5282
5283 SemaRef.Diag(Loc: NameLoc, DiagID: diag::err_anonymous_record_member_redecl)
5284 << IsUnion << Name;
5285 SemaRef.Diag(Loc: PrevDecl->getLocation(), DiagID: diag::note_previous_declaration);
5286
5287 return true;
5288}
5289
5290void Sema::ActOnDefinedDeclarationSpecifier(Decl *D) {
5291 if (auto *RD = dyn_cast_if_present<RecordDecl>(Val: D))
5292 DiagPlaceholderFieldDeclDefinitions(Record: RD);
5293}
5294
5295void Sema::DiagPlaceholderFieldDeclDefinitions(RecordDecl *Record) {
5296 if (!getLangOpts().CPlusPlus)
5297 return;
5298
5299 // This function can be parsed before we have validated the
5300 // structure as an anonymous struct
5301 if (Record->isAnonymousStructOrUnion())
5302 return;
5303
5304 const NamedDecl *First = 0;
5305 for (const Decl *D : Record->decls()) {
5306 const NamedDecl *ND = dyn_cast<NamedDecl>(Val: D);
5307 if (!ND || !ND->isPlaceholderVar(LangOpts: getLangOpts()))
5308 continue;
5309 if (!First)
5310 First = ND;
5311 else
5312 DiagPlaceholderVariableDefinition(Loc: ND->getLocation());
5313 }
5314}
5315
5316/// InjectAnonymousStructOrUnionMembers - Inject the members of the
5317/// anonymous struct or union AnonRecord into the owning context Owner
5318/// and scope S. This routine will be invoked just after we realize
5319/// that an unnamed union or struct is actually an anonymous union or
5320/// struct, e.g.,
5321///
5322/// @code
5323/// union {
5324/// int i;
5325/// float f;
5326/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and
5327/// // f into the surrounding scope.x
5328/// @endcode
5329///
5330/// This routine is recursive, injecting the names of nested anonymous
5331/// structs/unions into the owning context and scope as well.
5332static bool
5333InjectAnonymousStructOrUnionMembers(Sema &SemaRef, Scope *S, DeclContext *Owner,
5334 RecordDecl *AnonRecord, AccessSpecifier AS,
5335 StorageClass SC,
5336 SmallVectorImpl<NamedDecl *> &Chaining) {
5337 bool Invalid = false;
5338
5339 // Look every FieldDecl and IndirectFieldDecl with a name.
5340 for (auto *D : AnonRecord->decls()) {
5341 if ((isa<FieldDecl>(Val: D) || isa<IndirectFieldDecl>(Val: D)) &&
5342 cast<NamedDecl>(Val: D)->getDeclName()) {
5343 ValueDecl *VD = cast<ValueDecl>(Val: D);
5344 if (CheckAnonMemberRedeclaration(SemaRef, S, Owner, Name: VD->getDeclName(),
5345 NameLoc: VD->getLocation(), IsUnion: AnonRecord->isUnion(),
5346 SC)) {
5347 // C++ [class.union]p2:
5348 // The names of the members of an anonymous union shall be
5349 // distinct from the names of any other entity in the
5350 // scope in which the anonymous union is declared.
5351 Invalid = true;
5352 } else {
5353 // C++ [class.union]p2:
5354 // For the purpose of name lookup, after the anonymous union
5355 // definition, the members of the anonymous union are
5356 // considered to have been defined in the scope in which the
5357 // anonymous union is declared.
5358 unsigned OldChainingSize = Chaining.size();
5359 if (IndirectFieldDecl *IF = dyn_cast<IndirectFieldDecl>(Val: VD))
5360 Chaining.append(in_start: IF->chain_begin(), in_end: IF->chain_end());
5361 else
5362 Chaining.push_back(Elt: VD);
5363
5364 assert(Chaining.size() >= 2);
5365 NamedDecl **NamedChain =
5366 new (SemaRef.Context)NamedDecl*[Chaining.size()];
5367 for (unsigned i = 0; i < Chaining.size(); i++)
5368 NamedChain[i] = Chaining[i];
5369
5370 IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
5371 C&: SemaRef.Context, DC: Owner, L: VD->getLocation(), Id: VD->getIdentifier(),
5372 T: VD->getType(), CH: {NamedChain, Chaining.size()});
5373
5374 for (const auto *Attr : VD->attrs())
5375 IndirectField->addAttr(A: Attr->clone(C&: SemaRef.Context));
5376
5377 IndirectField->setAccess(AS);
5378 IndirectField->setImplicit();
5379 SemaRef.PushOnScopeChains(D: IndirectField, S);
5380
5381 // That includes picking up the appropriate access specifier.
5382 if (AS != AS_none) IndirectField->setAccess(AS);
5383
5384 Chaining.resize(N: OldChainingSize);
5385 }
5386 }
5387 }
5388
5389 return Invalid;
5390}
5391
5392/// StorageClassSpecToVarDeclStorageClass - Maps a DeclSpec::SCS to
5393/// a VarDecl::StorageClass. Any error reporting is up to the caller:
5394/// illegal input values are mapped to SC_None.
5395static StorageClass
5396StorageClassSpecToVarDeclStorageClass(const DeclSpec &DS) {
5397 DeclSpec::SCS StorageClassSpec = DS.getStorageClassSpec();
5398 assert(StorageClassSpec != DeclSpec::SCS_typedef &&
5399 "Parser allowed 'typedef' as storage class VarDecl.");
5400 switch (StorageClassSpec) {
5401 case DeclSpec::SCS_unspecified: return SC_None;
5402 case DeclSpec::SCS_extern:
5403 if (DS.isExternInLinkageSpec())
5404 return SC_None;
5405 return SC_Extern;
5406 case DeclSpec::SCS_static: return SC_Static;
5407 case DeclSpec::SCS_auto: return SC_Auto;
5408 case DeclSpec::SCS_register: return SC_Register;
5409 case DeclSpec::SCS_private_extern: return SC_PrivateExtern;
5410 // Illegal SCSs map to None: error reporting is up to the caller.
5411 case DeclSpec::SCS_mutable: // Fall through.
5412 case DeclSpec::SCS_typedef: return SC_None;
5413 }
5414 llvm_unreachable("unknown storage class specifier");
5415}
5416
5417static SourceLocation findDefaultInitializer(const CXXRecordDecl *Record) {
5418 assert(Record->hasInClassInitializer());
5419
5420 for (const auto *I : Record->decls()) {
5421 const auto *FD = dyn_cast<FieldDecl>(Val: I);
5422 if (const auto *IFD = dyn_cast<IndirectFieldDecl>(Val: I))
5423 FD = IFD->getAnonField();
5424 if (FD && FD->hasInClassInitializer())
5425 return FD->getLocation();
5426 }
5427
5428 llvm_unreachable("couldn't find in-class initializer");
5429}
5430
5431static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent,
5432 SourceLocation DefaultInitLoc) {
5433 if (!Parent->isUnion() || !Parent->hasInClassInitializer())
5434 return;
5435
5436 S.Diag(Loc: DefaultInitLoc, DiagID: diag::err_multiple_mem_union_initialization);
5437 S.Diag(Loc: findDefaultInitializer(Record: Parent), DiagID: diag::note_previous_initializer) << 0;
5438}
5439
5440static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent,
5441 CXXRecordDecl *AnonUnion) {
5442 if (!Parent->isUnion() || !Parent->hasInClassInitializer())
5443 return;
5444
5445 checkDuplicateDefaultInit(S, Parent, DefaultInitLoc: findDefaultInitializer(Record: AnonUnion));
5446}
5447
5448Decl *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
5449 AccessSpecifier AS,
5450 RecordDecl *Record,
5451 const PrintingPolicy &Policy) {
5452 DeclContext *Owner = Record->getDeclContext();
5453
5454 // Diagnose whether this anonymous struct/union is an extension.
5455 if (Record->isUnion() && !getLangOpts().CPlusPlus && !getLangOpts().C11)
5456 Diag(Loc: Record->getLocation(), DiagID: diag::ext_anonymous_union);
5457 else if (!Record->isUnion() && getLangOpts().CPlusPlus)
5458 Diag(Loc: Record->getLocation(), DiagID: diag::ext_gnu_anonymous_struct);
5459 else if (!Record->isUnion() && !getLangOpts().C11)
5460 Diag(Loc: Record->getLocation(), DiagID: diag::ext_c11_anonymous_struct);
5461
5462 // C and C++ require different kinds of checks for anonymous
5463 // structs/unions.
5464 bool Invalid = false;
5465 if (getLangOpts().CPlusPlus) {
5466 const char *PrevSpec = nullptr;
5467 if (Record->isUnion()) {
5468 // C++ [class.union]p6:
5469 // C++17 [class.union.anon]p2:
5470 // Anonymous unions declared in a named namespace or in the
5471 // global namespace shall be declared static.
5472 unsigned DiagID;
5473 DeclContext *OwnerScope = Owner->getRedeclContext();
5474 if (DS.getStorageClassSpec() != DeclSpec::SCS_static &&
5475 (OwnerScope->isTranslationUnit() ||
5476 (OwnerScope->isNamespace() &&
5477 !cast<NamespaceDecl>(Val: OwnerScope)->isAnonymousNamespace()))) {
5478 Diag(Loc: Record->getLocation(), DiagID: diag::err_anonymous_union_not_static)
5479 << FixItHint::CreateInsertion(InsertionLoc: Record->getLocation(), Code: "static ");
5480
5481 // Recover by adding 'static'.
5482 DS.SetStorageClassSpec(S&: *this, SC: DeclSpec::SCS_static, Loc: SourceLocation(),
5483 PrevSpec, DiagID, Policy);
5484 }
5485 // C++ [class.union]p6:
5486 // A storage class is not allowed in a declaration of an
5487 // anonymous union in a class scope.
5488 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
5489 isa<RecordDecl>(Val: Owner)) {
5490 Diag(Loc: DS.getStorageClassSpecLoc(),
5491 DiagID: diag::err_anonymous_union_with_storage_spec)
5492 << FixItHint::CreateRemoval(RemoveRange: DS.getStorageClassSpecLoc());
5493
5494 // Recover by removing the storage specifier.
5495 DS.SetStorageClassSpec(S&: *this, SC: DeclSpec::SCS_unspecified,
5496 Loc: SourceLocation(),
5497 PrevSpec, DiagID, Policy: Context.getPrintingPolicy());
5498 }
5499 }
5500
5501 // Ignore const/volatile/restrict qualifiers.
5502 if (DS.getTypeQualifiers()) {
5503 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
5504 Diag(Loc: DS.getConstSpecLoc(), DiagID: diag::ext_anonymous_struct_union_qualified)
5505 << Record->isUnion() << "const"
5506 << FixItHint::CreateRemoval(RemoveRange: DS.getConstSpecLoc());
5507 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
5508 Diag(Loc: DS.getVolatileSpecLoc(),
5509 DiagID: diag::ext_anonymous_struct_union_qualified)
5510 << Record->isUnion() << "volatile"
5511 << FixItHint::CreateRemoval(RemoveRange: DS.getVolatileSpecLoc());
5512 if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
5513 Diag(Loc: DS.getRestrictSpecLoc(),
5514 DiagID: diag::ext_anonymous_struct_union_qualified)
5515 << Record->isUnion() << "restrict"
5516 << FixItHint::CreateRemoval(RemoveRange: DS.getRestrictSpecLoc());
5517 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
5518 Diag(Loc: DS.getAtomicSpecLoc(),
5519 DiagID: diag::ext_anonymous_struct_union_qualified)
5520 << Record->isUnion() << "_Atomic"
5521 << FixItHint::CreateRemoval(RemoveRange: DS.getAtomicSpecLoc());
5522 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
5523 Diag(Loc: DS.getUnalignedSpecLoc(),
5524 DiagID: diag::ext_anonymous_struct_union_qualified)
5525 << Record->isUnion() << "__unaligned"
5526 << FixItHint::CreateRemoval(RemoveRange: DS.getUnalignedSpecLoc());
5527
5528 DS.ClearTypeQualifiers();
5529 }
5530
5531 // C++ [class.union]p2:
5532 // The member-specification of an anonymous union shall only
5533 // define non-static data members. [Note: nested types and
5534 // functions cannot be declared within an anonymous union. ]
5535 for (auto *Mem : Record->decls()) {
5536 // Ignore invalid declarations; we already diagnosed them.
5537 if (Mem->isInvalidDecl())
5538 continue;
5539
5540 if (auto *FD = dyn_cast<FieldDecl>(Val: Mem)) {
5541 // C++ [class.union]p3:
5542 // An anonymous union shall not have private or protected
5543 // members (clause 11).
5544 assert(FD->getAccess() != AS_none);
5545 if (FD->getAccess() != AS_public) {
5546 Diag(Loc: FD->getLocation(), DiagID: diag::err_anonymous_record_nonpublic_member)
5547 << Record->isUnion() << (FD->getAccess() == AS_protected);
5548 Invalid = true;
5549 }
5550
5551 // C++ [class.union]p1
5552 // An object of a class with a non-trivial constructor, a non-trivial
5553 // copy constructor, a non-trivial destructor, or a non-trivial copy
5554 // assignment operator cannot be a member of a union, nor can an
5555 // array of such objects.
5556 if (CheckNontrivialField(FD))
5557 Invalid = true;
5558 } else if (Mem->isImplicit()) {
5559 // Any implicit members are fine.
5560 } else if (isa<TagDecl>(Val: Mem) && Mem->getDeclContext() != Record) {
5561 // This is a type that showed up in an
5562 // elaborated-type-specifier inside the anonymous struct or
5563 // union, but which actually declares a type outside of the
5564 // anonymous struct or union. It's okay.
5565 } else if (auto *MemRecord = dyn_cast<RecordDecl>(Val: Mem)) {
5566 if (!MemRecord->isAnonymousStructOrUnion() &&
5567 MemRecord->getDeclName()) {
5568 // Visual C++ allows type definition in anonymous struct or union.
5569 if (getLangOpts().MicrosoftExt)
5570 Diag(Loc: MemRecord->getLocation(), DiagID: diag::ext_anonymous_record_with_type)
5571 << Record->isUnion();
5572 else {
5573 // This is a nested type declaration.
5574 Diag(Loc: MemRecord->getLocation(), DiagID: diag::err_anonymous_record_with_type)
5575 << Record->isUnion();
5576 Invalid = true;
5577 }
5578 } else {
5579 // This is an anonymous type definition within another anonymous type.
5580 // This is a popular extension, provided by Plan9, MSVC and GCC, but
5581 // not part of standard C++.
5582 Diag(Loc: MemRecord->getLocation(),
5583 DiagID: diag::ext_anonymous_record_with_anonymous_type)
5584 << Record->isUnion();
5585 }
5586 } else if (isa<AccessSpecDecl>(Val: Mem)) {
5587 // Any access specifier is fine.
5588 } else if (isa<StaticAssertDecl>(Val: Mem)) {
5589 // In C++1z, static_assert declarations are also fine.
5590 } else {
5591 // We have something that isn't a non-static data
5592 // member. Complain about it.
5593 unsigned DK = diag::err_anonymous_record_bad_member;
5594 if (isa<TypeDecl>(Val: Mem))
5595 DK = diag::err_anonymous_record_with_type;
5596 else if (isa<FunctionDecl>(Val: Mem))
5597 DK = diag::err_anonymous_record_with_function;
5598 else if (isa<VarDecl>(Val: Mem))
5599 DK = diag::err_anonymous_record_with_static;
5600
5601 // Visual C++ allows type definition in anonymous struct or union.
5602 if (getLangOpts().MicrosoftExt &&
5603 DK == diag::err_anonymous_record_with_type)
5604 Diag(Loc: Mem->getLocation(), DiagID: diag::ext_anonymous_record_with_type)
5605 << Record->isUnion();
5606 else {
5607 Diag(Loc: Mem->getLocation(), DiagID: DK) << Record->isUnion();
5608 Invalid = true;
5609 }
5610 }
5611 }
5612
5613 // C++11 [class.union]p8 (DR1460):
5614 // At most one variant member of a union may have a
5615 // brace-or-equal-initializer.
5616 if (cast<CXXRecordDecl>(Val: Record)->hasInClassInitializer() &&
5617 Owner->isRecord())
5618 checkDuplicateDefaultInit(S&: *this, Parent: cast<CXXRecordDecl>(Val: Owner),
5619 AnonUnion: cast<CXXRecordDecl>(Val: Record));
5620 }
5621
5622 if (!Record->isUnion() && !Owner->isRecord()) {
5623 Diag(Loc: Record->getLocation(), DiagID: diag::err_anonymous_struct_not_member)
5624 << getLangOpts().CPlusPlus;
5625 Invalid = true;
5626 }
5627
5628 // C++ [dcl.dcl]p3:
5629 // [If there are no declarators], and except for the declaration of an
5630 // unnamed bit-field, the decl-specifier-seq shall introduce one or more
5631 // names into the program
5632 // C++ [class.mem]p2:
5633 // each such member-declaration shall either declare at least one member
5634 // name of the class or declare at least one unnamed bit-field
5635 //
5636 // For C this is an error even for a named struct, and is diagnosed elsewhere.
5637 if (getLangOpts().CPlusPlus && Record->field_empty())
5638 Diag(Loc: DS.getBeginLoc(), DiagID: diag::ext_no_declarators) << DS.getSourceRange();
5639
5640 // Mock up a declarator.
5641 Declarator Dc(DS, ParsedAttributesView::none(), DeclaratorContext::Member);
5642 StorageClass SC = StorageClassSpecToVarDeclStorageClass(DS);
5643 TypeSourceInfo *TInfo = GetTypeForDeclarator(D&: Dc);
5644 assert(TInfo && "couldn't build declarator info for anonymous struct/union");
5645
5646 // Create a declaration for this anonymous struct/union.
5647 NamedDecl *Anon = nullptr;
5648 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Val: Owner)) {
5649 Anon = FieldDecl::Create(
5650 C: Context, DC: OwningClass, StartLoc: DS.getBeginLoc(), IdLoc: Record->getLocation(),
5651 /*IdentifierInfo=*/Id: nullptr, T: Context.getTypeDeclType(Decl: Record), TInfo,
5652 /*BitWidth=*/BW: nullptr, /*Mutable=*/false,
5653 /*InitStyle=*/ICIS_NoInit);
5654 Anon->setAccess(AS);
5655 ProcessDeclAttributes(S, D: Anon, PD: Dc);
5656
5657 if (getLangOpts().CPlusPlus)
5658 FieldCollector->Add(D: cast<FieldDecl>(Val: Anon));
5659 } else {
5660 DeclSpec::SCS SCSpec = DS.getStorageClassSpec();
5661 if (SCSpec == DeclSpec::SCS_mutable) {
5662 // mutable can only appear on non-static class members, so it's always
5663 // an error here
5664 Diag(Loc: Record->getLocation(), DiagID: diag::err_mutable_nonmember);
5665 Invalid = true;
5666 SC = SC_None;
5667 }
5668
5669 Anon = VarDecl::Create(C&: Context, DC: Owner, StartLoc: DS.getBeginLoc(),
5670 IdLoc: Record->getLocation(), /*IdentifierInfo=*/Id: nullptr,
5671 T: Context.getTypeDeclType(Decl: Record), TInfo, S: SC);
5672 if (Invalid)
5673 Anon->setInvalidDecl();
5674
5675 ProcessDeclAttributes(S, D: Anon, PD: Dc);
5676
5677 // Default-initialize the implicit variable. This initialization will be
5678 // trivial in almost all cases, except if a union member has an in-class
5679 // initializer:
5680 // union { int n = 0; };
5681 ActOnUninitializedDecl(dcl: Anon);
5682 }
5683 Anon->setImplicit();
5684
5685 // Mark this as an anonymous struct/union type.
5686 Record->setAnonymousStructOrUnion(true);
5687
5688 // Add the anonymous struct/union object to the current
5689 // context. We'll be referencing this object when we refer to one of
5690 // its members.
5691 Owner->addDecl(D: Anon);
5692
5693 // Inject the members of the anonymous struct/union into the owning
5694 // context and into the identifier resolver chain for name lookup
5695 // purposes.
5696 SmallVector<NamedDecl*, 2> Chain;
5697 Chain.push_back(Elt: Anon);
5698
5699 if (InjectAnonymousStructOrUnionMembers(SemaRef&: *this, S, Owner, AnonRecord: Record, AS, SC,
5700 Chaining&: Chain))
5701 Invalid = true;
5702
5703 if (VarDecl *NewVD = dyn_cast<VarDecl>(Val: Anon)) {
5704 if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
5705 MangleNumberingContext *MCtx;
5706 Decl *ManglingContextDecl;
5707 std::tie(args&: MCtx, args&: ManglingContextDecl) =
5708 getCurrentMangleNumberContext(DC: NewVD->getDeclContext());
5709 if (MCtx) {
5710 Context.setManglingNumber(
5711 ND: NewVD, Number: MCtx->getManglingNumber(
5712 VD: NewVD, MSLocalManglingNumber: getMSManglingNumber(LO: getLangOpts(), S)));
5713 Context.setStaticLocalNumber(VD: NewVD, Number: MCtx->getStaticLocalNumber(VD: NewVD));
5714 }
5715 }
5716 }
5717
5718 if (Invalid)
5719 Anon->setInvalidDecl();
5720
5721 return Anon;
5722}
5723
5724Decl *Sema::BuildMicrosoftCAnonymousStruct(Scope *S, DeclSpec &DS,
5725 RecordDecl *Record) {
5726 assert(Record && "expected a record!");
5727
5728 // Mock up a declarator.
5729 Declarator Dc(DS, ParsedAttributesView::none(), DeclaratorContext::TypeName);
5730 TypeSourceInfo *TInfo = GetTypeForDeclarator(D&: Dc);
5731 assert(TInfo && "couldn't build declarator info for anonymous struct");
5732
5733 auto *ParentDecl = cast<RecordDecl>(Val: CurContext);
5734 QualType RecTy = Context.getTypeDeclType(Decl: Record);
5735
5736 // Create a declaration for this anonymous struct.
5737 NamedDecl *Anon =
5738 FieldDecl::Create(C: Context, DC: ParentDecl, StartLoc: DS.getBeginLoc(), IdLoc: DS.getBeginLoc(),
5739 /*IdentifierInfo=*/Id: nullptr, T: RecTy, TInfo,
5740 /*BitWidth=*/BW: nullptr, /*Mutable=*/false,
5741 /*InitStyle=*/ICIS_NoInit);
5742 Anon->setImplicit();
5743
5744 // Add the anonymous struct object to the current context.
5745 CurContext->addDecl(D: Anon);
5746
5747 // Inject the members of the anonymous struct into the current
5748 // context and into the identifier resolver chain for name lookup
5749 // purposes.
5750 SmallVector<NamedDecl*, 2> Chain;
5751 Chain.push_back(Elt: Anon);
5752
5753 RecordDecl *RecordDef = Record->getDefinition();
5754 if (RequireCompleteSizedType(Loc: Anon->getLocation(), T: RecTy,
5755 DiagID: diag::err_field_incomplete_or_sizeless) ||
5756 InjectAnonymousStructOrUnionMembers(
5757 SemaRef&: *this, S, Owner: CurContext, AnonRecord: RecordDef, AS: AS_none,
5758 SC: StorageClassSpecToVarDeclStorageClass(DS), Chaining&: Chain)) {
5759 Anon->setInvalidDecl();
5760 ParentDecl->setInvalidDecl();
5761 }
5762
5763 return Anon;
5764}
5765
5766DeclarationNameInfo Sema::GetNameForDeclarator(Declarator &D) {
5767 return GetNameFromUnqualifiedId(Name: D.getName());
5768}
5769
5770DeclarationNameInfo
5771Sema::GetNameFromUnqualifiedId(const UnqualifiedId &Name) {
5772 DeclarationNameInfo NameInfo;
5773 NameInfo.setLoc(Name.StartLocation);
5774
5775 switch (Name.getKind()) {
5776
5777 case UnqualifiedIdKind::IK_ImplicitSelfParam:
5778 case UnqualifiedIdKind::IK_Identifier:
5779 NameInfo.setName(Name.Identifier);
5780 return NameInfo;
5781
5782 case UnqualifiedIdKind::IK_DeductionGuideName: {
5783 // C++ [temp.deduct.guide]p3:
5784 // The simple-template-id shall name a class template specialization.
5785 // The template-name shall be the same identifier as the template-name
5786 // of the simple-template-id.
5787 // These together intend to imply that the template-name shall name a
5788 // class template.
5789 // FIXME: template<typename T> struct X {};
5790 // template<typename T> using Y = X<T>;
5791 // Y(int) -> Y<int>;
5792 // satisfies these rules but does not name a class template.
5793 TemplateName TN = Name.TemplateName.get().get();
5794 auto *Template = TN.getAsTemplateDecl();
5795 if (!Template || !isa<ClassTemplateDecl>(Val: Template)) {
5796 Diag(Loc: Name.StartLocation,
5797 DiagID: diag::err_deduction_guide_name_not_class_template)
5798 << (int)getTemplateNameKindForDiagnostics(Name: TN) << TN;
5799 if (Template)
5800 NoteTemplateLocation(Decl: *Template);
5801 return DeclarationNameInfo();
5802 }
5803
5804 NameInfo.setName(
5805 Context.DeclarationNames.getCXXDeductionGuideName(TD: Template));
5806 return NameInfo;
5807 }
5808
5809 case UnqualifiedIdKind::IK_OperatorFunctionId:
5810 NameInfo.setName(Context.DeclarationNames.getCXXOperatorName(
5811 Op: Name.OperatorFunctionId.Operator));
5812 NameInfo.setCXXOperatorNameRange(SourceRange(
5813 Name.OperatorFunctionId.SymbolLocations[0], Name.EndLocation));
5814 return NameInfo;
5815
5816 case UnqualifiedIdKind::IK_LiteralOperatorId:
5817 NameInfo.setName(Context.DeclarationNames.getCXXLiteralOperatorName(
5818 II: Name.Identifier));
5819 NameInfo.setCXXLiteralOperatorNameLoc(Name.EndLocation);
5820 return NameInfo;
5821
5822 case UnqualifiedIdKind::IK_ConversionFunctionId: {
5823 TypeSourceInfo *TInfo;
5824 QualType Ty = GetTypeFromParser(Ty: Name.ConversionFunctionId, TInfo: &TInfo);
5825 if (Ty.isNull())
5826 return DeclarationNameInfo();
5827 NameInfo.setName(Context.DeclarationNames.getCXXConversionFunctionName(
5828 Ty: Context.getCanonicalType(T: Ty)));
5829 NameInfo.setNamedTypeInfo(TInfo);
5830 return NameInfo;
5831 }
5832
5833 case UnqualifiedIdKind::IK_ConstructorName: {
5834 TypeSourceInfo *TInfo;
5835 QualType Ty = GetTypeFromParser(Ty: Name.ConstructorName, TInfo: &TInfo);
5836 if (Ty.isNull())
5837 return DeclarationNameInfo();
5838 NameInfo.setName(Context.DeclarationNames.getCXXConstructorName(
5839 Ty: Context.getCanonicalType(T: Ty)));
5840 NameInfo.setNamedTypeInfo(TInfo);
5841 return NameInfo;
5842 }
5843
5844 case UnqualifiedIdKind::IK_ConstructorTemplateId: {
5845 // In well-formed code, we can only have a constructor
5846 // template-id that refers to the current context, so go there
5847 // to find the actual type being constructed.
5848 CXXRecordDecl *CurClass = dyn_cast<CXXRecordDecl>(Val: CurContext);
5849 if (!CurClass || CurClass->getIdentifier() != Name.TemplateId->Name)
5850 return DeclarationNameInfo();
5851
5852 // Determine the type of the class being constructed.
5853 QualType CurClassType = Context.getTypeDeclType(Decl: CurClass);
5854
5855 // FIXME: Check two things: that the template-id names the same type as
5856 // CurClassType, and that the template-id does not occur when the name
5857 // was qualified.
5858
5859 NameInfo.setName(Context.DeclarationNames.getCXXConstructorName(
5860 Ty: Context.getCanonicalType(T: CurClassType)));
5861 // FIXME: should we retrieve TypeSourceInfo?
5862 NameInfo.setNamedTypeInfo(nullptr);
5863 return NameInfo;
5864 }
5865
5866 case UnqualifiedIdKind::IK_DestructorName: {
5867 TypeSourceInfo *TInfo;
5868 QualType Ty = GetTypeFromParser(Ty: Name.DestructorName, TInfo: &TInfo);
5869 if (Ty.isNull())
5870 return DeclarationNameInfo();
5871 NameInfo.setName(Context.DeclarationNames.getCXXDestructorName(
5872 Ty: Context.getCanonicalType(T: Ty)));
5873 NameInfo.setNamedTypeInfo(TInfo);
5874 return NameInfo;
5875 }
5876
5877 case UnqualifiedIdKind::IK_TemplateId: {
5878 TemplateName TName = Name.TemplateId->Template.get();
5879 SourceLocation TNameLoc = Name.TemplateId->TemplateNameLoc;
5880 return Context.getNameForTemplate(Name: TName, NameLoc: TNameLoc);
5881 }
5882
5883 } // switch (Name.getKind())
5884
5885 llvm_unreachable("Unknown name kind");
5886}
5887
5888static QualType getCoreType(QualType Ty) {
5889 do {
5890 if (Ty->isPointerType() || Ty->isReferenceType())
5891 Ty = Ty->getPointeeType();
5892 else if (Ty->isArrayType())
5893 Ty = Ty->castAsArrayTypeUnsafe()->getElementType();
5894 else
5895 return Ty.withoutLocalFastQualifiers();
5896 } while (true);
5897}
5898
5899/// hasSimilarParameters - Determine whether the C++ functions Declaration
5900/// and Definition have "nearly" matching parameters. This heuristic is
5901/// used to improve diagnostics in the case where an out-of-line function
5902/// definition doesn't match any declaration within the class or namespace.
5903/// Also sets Params to the list of indices to the parameters that differ
5904/// between the declaration and the definition. If hasSimilarParameters
5905/// returns true and Params is empty, then all of the parameters match.
5906static bool hasSimilarParameters(ASTContext &Context,
5907 FunctionDecl *Declaration,
5908 FunctionDecl *Definition,
5909 SmallVectorImpl<unsigned> &Params) {
5910 Params.clear();
5911 if (Declaration->param_size() != Definition->param_size())
5912 return false;
5913 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) {
5914 QualType DeclParamTy = Declaration->getParamDecl(i: Idx)->getType();
5915 QualType DefParamTy = Definition->getParamDecl(i: Idx)->getType();
5916
5917 // The parameter types are identical
5918 if (Context.hasSameUnqualifiedType(T1: DefParamTy, T2: DeclParamTy))
5919 continue;
5920
5921 QualType DeclParamBaseTy = getCoreType(Ty: DeclParamTy);
5922 QualType DefParamBaseTy = getCoreType(Ty: DefParamTy);
5923 const IdentifierInfo *DeclTyName = DeclParamBaseTy.getBaseTypeIdentifier();
5924 const IdentifierInfo *DefTyName = DefParamBaseTy.getBaseTypeIdentifier();
5925
5926 if (Context.hasSameUnqualifiedType(T1: DeclParamBaseTy, T2: DefParamBaseTy) ||
5927 (DeclTyName && DeclTyName == DefTyName))
5928 Params.push_back(Elt: Idx);
5929 else // The two parameters aren't even close
5930 return false;
5931 }
5932
5933 return true;
5934}
5935
5936/// RebuildDeclaratorInCurrentInstantiation - Checks whether the given
5937/// declarator needs to be rebuilt in the current instantiation.
5938/// Any bits of declarator which appear before the name are valid for
5939/// consideration here. That's specifically the type in the decl spec
5940/// and the base type in any member-pointer chunks.
5941static bool RebuildDeclaratorInCurrentInstantiation(Sema &S, Declarator &D,
5942 DeclarationName Name) {
5943 // The types we specifically need to rebuild are:
5944 // - typenames, typeofs, and decltypes
5945 // - types which will become injected class names
5946 // Of course, we also need to rebuild any type referencing such a
5947 // type. It's safest to just say "dependent", but we call out a
5948 // few cases here.
5949
5950 DeclSpec &DS = D.getMutableDeclSpec();
5951 switch (DS.getTypeSpecType()) {
5952 case DeclSpec::TST_typename:
5953 case DeclSpec::TST_typeofType:
5954 case DeclSpec::TST_typeof_unqualType:
5955#define TRANSFORM_TYPE_TRAIT_DEF(_, Trait) case DeclSpec::TST_##Trait:
5956#include "clang/Basic/TransformTypeTraits.def"
5957 case DeclSpec::TST_atomic: {
5958 // Grab the type from the parser.
5959 TypeSourceInfo *TSI = nullptr;
5960 QualType T = S.GetTypeFromParser(Ty: DS.getRepAsType(), TInfo: &TSI);
5961 if (T.isNull() || !T->isInstantiationDependentType()) break;
5962
5963 // Make sure there's a type source info. This isn't really much
5964 // of a waste; most dependent types should have type source info
5965 // attached already.
5966 if (!TSI)
5967 TSI = S.Context.getTrivialTypeSourceInfo(T, Loc: DS.getTypeSpecTypeLoc());
5968
5969 // Rebuild the type in the current instantiation.
5970 TSI = S.RebuildTypeInCurrentInstantiation(T: TSI, Loc: D.getIdentifierLoc(), Name);
5971 if (!TSI) return true;
5972
5973 // Store the new type back in the decl spec.
5974 ParsedType LocType = S.CreateParsedType(T: TSI->getType(), TInfo: TSI);
5975 DS.UpdateTypeRep(Rep: LocType);
5976 break;
5977 }
5978
5979 case DeclSpec::TST_decltype:
5980 case DeclSpec::TST_typeof_unqualExpr:
5981 case DeclSpec::TST_typeofExpr: {
5982 Expr *E = DS.getRepAsExpr();
5983 ExprResult Result = S.RebuildExprInCurrentInstantiation(E);
5984 if (Result.isInvalid()) return true;
5985 DS.UpdateExprRep(Rep: Result.get());
5986 break;
5987 }
5988
5989 default:
5990 // Nothing to do for these decl specs.
5991 break;
5992 }
5993
5994 // It doesn't matter what order we do this in.
5995 for (unsigned I = 0, E = D.getNumTypeObjects(); I != E; ++I) {
5996 DeclaratorChunk &Chunk = D.getTypeObject(i: I);
5997
5998 // The only type information in the declarator which can come
5999 // before the declaration name is the base type of a member
6000 // pointer.
6001 if (Chunk.Kind != DeclaratorChunk::MemberPointer)
6002 continue;
6003
6004 // Rebuild the scope specifier in-place.
6005 CXXScopeSpec &SS = Chunk.Mem.Scope();
6006 if (S.RebuildNestedNameSpecifierInCurrentInstantiation(SS))
6007 return true;
6008 }
6009
6010 return false;
6011}
6012
6013/// Returns true if the declaration is declared in a system header or from a
6014/// system macro.
6015static bool isFromSystemHeader(SourceManager &SM, const Decl *D) {
6016 return SM.isInSystemHeader(Loc: D->getLocation()) ||
6017 SM.isInSystemMacro(loc: D->getLocation());
6018}
6019
6020void Sema::warnOnReservedIdentifier(const NamedDecl *D) {
6021 // Avoid warning twice on the same identifier, and don't warn on redeclaration
6022 // of system decl.
6023 if (D->getPreviousDecl() || D->isImplicit())
6024 return;
6025 ReservedIdentifierStatus Status = D->isReserved(LangOpts: getLangOpts());
6026 if (Status != ReservedIdentifierStatus::NotReserved &&
6027 !isFromSystemHeader(SM&: Context.getSourceManager(), D)) {
6028 Diag(Loc: D->getLocation(), DiagID: diag::warn_reserved_extern_symbol)
6029 << D << static_cast<int>(Status);
6030 }
6031}
6032
6033Decl *Sema::ActOnDeclarator(Scope *S, Declarator &D) {
6034 D.setFunctionDefinitionKind(FunctionDefinitionKind::Declaration);
6035
6036 // Check if we are in an `omp begin/end declare variant` scope. Handle this
6037 // declaration only if the `bind_to_declaration` extension is set.
6038 SmallVector<FunctionDecl *, 4> Bases;
6039 if (LangOpts.OpenMP && OpenMP().isInOpenMPDeclareVariantScope())
6040 if (OpenMP().getOMPTraitInfoForSurroundingScope()->isExtensionActive(
6041 TP: llvm::omp::TraitProperty::
6042 implementation_extension_bind_to_declaration))
6043 OpenMP().ActOnStartOfFunctionDefinitionInOpenMPDeclareVariantScope(
6044 S, D, TemplateParameterLists: MultiTemplateParamsArg(), Bases);
6045
6046 Decl *Dcl = HandleDeclarator(S, D, TemplateParameterLists: MultiTemplateParamsArg());
6047
6048 if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer() &&
6049 Dcl && Dcl->getDeclContext()->isFileContext())
6050 Dcl->setTopLevelDeclInObjCContainer();
6051
6052 if (!Bases.empty())
6053 OpenMP().ActOnFinishedFunctionDefinitionInOpenMPDeclareVariantScope(D: Dcl,
6054 Bases);
6055
6056 return Dcl;
6057}
6058
6059bool Sema::DiagnoseClassNameShadow(DeclContext *DC,
6060 DeclarationNameInfo NameInfo) {
6061 DeclarationName Name = NameInfo.getName();
6062
6063 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Val: DC);
6064 while (Record && Record->isAnonymousStructOrUnion())
6065 Record = dyn_cast<CXXRecordDecl>(Val: Record->getParent());
6066 if (Record && Record->getIdentifier() && Record->getDeclName() == Name) {
6067 Diag(Loc: NameInfo.getLoc(), DiagID: diag::err_member_name_of_class) << Name;
6068 return true;
6069 }
6070
6071 return false;
6072}
6073
6074bool Sema::diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
6075 DeclarationName Name,
6076 SourceLocation Loc,
6077 TemplateIdAnnotation *TemplateId,
6078 bool IsMemberSpecialization) {
6079 assert(SS.isValid() && "diagnoseQualifiedDeclaration called for declaration "
6080 "without nested-name-specifier");
6081 DeclContext *Cur = CurContext;
6082 while (isa<LinkageSpecDecl>(Val: Cur) || isa<CapturedDecl>(Val: Cur))
6083 Cur = Cur->getParent();
6084
6085 // If the user provided a superfluous scope specifier that refers back to the
6086 // class in which the entity is already declared, diagnose and ignore it.
6087 //
6088 // class X {
6089 // void X::f();
6090 // };
6091 //
6092 // Note, it was once ill-formed to give redundant qualification in all
6093 // contexts, but that rule was removed by DR482.
6094 if (Cur->Equals(DC)) {
6095 if (Cur->isRecord()) {
6096 Diag(Loc, DiagID: LangOpts.MicrosoftExt ? diag::warn_member_extra_qualification
6097 : diag::err_member_extra_qualification)
6098 << Name << FixItHint::CreateRemoval(RemoveRange: SS.getRange());
6099 SS.clear();
6100 } else {
6101 Diag(Loc, DiagID: diag::warn_namespace_member_extra_qualification) << Name;
6102 }
6103 return false;
6104 }
6105
6106 // Check whether the qualifying scope encloses the scope of the original
6107 // declaration. For a template-id, we perform the checks in
6108 // CheckTemplateSpecializationScope.
6109 if (!Cur->Encloses(DC) && !(TemplateId || IsMemberSpecialization)) {
6110 if (Cur->isRecord())
6111 Diag(Loc, DiagID: diag::err_member_qualification)
6112 << Name << SS.getRange();
6113 else if (isa<TranslationUnitDecl>(Val: DC))
6114 Diag(Loc, DiagID: diag::err_invalid_declarator_global_scope)
6115 << Name << SS.getRange();
6116 else if (isa<FunctionDecl>(Val: Cur))
6117 Diag(Loc, DiagID: diag::err_invalid_declarator_in_function)
6118 << Name << SS.getRange();
6119 else if (isa<BlockDecl>(Val: Cur))
6120 Diag(Loc, DiagID: diag::err_invalid_declarator_in_block)
6121 << Name << SS.getRange();
6122 else if (isa<ExportDecl>(Val: Cur)) {
6123 if (!isa<NamespaceDecl>(Val: DC))
6124 Diag(Loc, DiagID: diag::err_export_non_namespace_scope_name)
6125 << Name << SS.getRange();
6126 else
6127 // The cases that DC is not NamespaceDecl should be handled in
6128 // CheckRedeclarationExported.
6129 return false;
6130 } else
6131 Diag(Loc, DiagID: diag::err_invalid_declarator_scope)
6132 << Name << cast<NamedDecl>(Val: Cur) << cast<NamedDecl>(Val: DC) << SS.getRange();
6133
6134 return true;
6135 }
6136
6137 if (Cur->isRecord()) {
6138 // Cannot qualify members within a class.
6139 Diag(Loc, DiagID: diag::err_member_qualification)
6140 << Name << SS.getRange();
6141 SS.clear();
6142
6143 // C++ constructors and destructors with incorrect scopes can break
6144 // our AST invariants by having the wrong underlying types. If
6145 // that's the case, then drop this declaration entirely.
6146 if ((Name.getNameKind() == DeclarationName::CXXConstructorName ||
6147 Name.getNameKind() == DeclarationName::CXXDestructorName) &&
6148 !Context.hasSameType(T1: Name.getCXXNameType(),
6149 T2: Context.getTypeDeclType(Decl: cast<CXXRecordDecl>(Val: Cur))))
6150 return true;
6151
6152 return false;
6153 }
6154
6155 // C++23 [temp.names]p5:
6156 // The keyword template shall not appear immediately after a declarative
6157 // nested-name-specifier.
6158 //
6159 // First check the template-id (if any), and then check each component of the
6160 // nested-name-specifier in reverse order.
6161 //
6162 // FIXME: nested-name-specifiers in friend declarations are declarative,
6163 // but we don't call diagnoseQualifiedDeclaration for them. We should.
6164 if (TemplateId && TemplateId->TemplateKWLoc.isValid())
6165 Diag(Loc, DiagID: diag::ext_template_after_declarative_nns)
6166 << FixItHint::CreateRemoval(RemoveRange: TemplateId->TemplateKWLoc);
6167
6168 NestedNameSpecifierLoc SpecLoc(SS.getScopeRep(), SS.location_data());
6169 do {
6170 if (SpecLoc.getNestedNameSpecifier()->getKind() ==
6171 NestedNameSpecifier::TypeSpecWithTemplate)
6172 Diag(Loc, DiagID: diag::ext_template_after_declarative_nns)
6173 << FixItHint::CreateRemoval(
6174 RemoveRange: SpecLoc.getTypeLoc().getTemplateKeywordLoc());
6175
6176 if (const Type *T = SpecLoc.getNestedNameSpecifier()->getAsType()) {
6177 if (const auto *TST = T->getAsAdjusted<TemplateSpecializationType>()) {
6178 // C++23 [expr.prim.id.qual]p3:
6179 // [...] If a nested-name-specifier N is declarative and has a
6180 // simple-template-id with a template argument list A that involves a
6181 // template parameter, let T be the template nominated by N without A.
6182 // T shall be a class template.
6183 if (TST->isDependentType() && TST->isTypeAlias())
6184 Diag(Loc, DiagID: diag::ext_alias_template_in_declarative_nns)
6185 << SpecLoc.getLocalSourceRange();
6186 } else if (T->isDecltypeType() || T->getAsAdjusted<PackIndexingType>()) {
6187 // C++23 [expr.prim.id.qual]p2:
6188 // [...] A declarative nested-name-specifier shall not have a
6189 // computed-type-specifier.
6190 //
6191 // CWG2858 changed this from 'decltype-specifier' to
6192 // 'computed-type-specifier'.
6193 Diag(Loc, DiagID: diag::err_computed_type_in_declarative_nns)
6194 << T->isDecltypeType() << SpecLoc.getTypeLoc().getSourceRange();
6195 }
6196 }
6197 } while ((SpecLoc = SpecLoc.getPrefix()));
6198
6199 return false;
6200}
6201
6202NamedDecl *Sema::HandleDeclarator(Scope *S, Declarator &D,
6203 MultiTemplateParamsArg TemplateParamLists) {
6204 // TODO: consider using NameInfo for diagnostic.
6205 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
6206 DeclarationName Name = NameInfo.getName();
6207
6208 // All of these full declarators require an identifier. If it doesn't have
6209 // one, the ParsedFreeStandingDeclSpec action should be used.
6210 if (D.isDecompositionDeclarator()) {
6211 return ActOnDecompositionDeclarator(S, D, TemplateParamLists);
6212 } else if (!Name) {
6213 if (!D.isInvalidType()) // Reject this if we think it is valid.
6214 Diag(Loc: D.getDeclSpec().getBeginLoc(), DiagID: diag::err_declarator_need_ident)
6215 << D.getDeclSpec().getSourceRange() << D.getSourceRange();
6216 return nullptr;
6217 } else if (DiagnoseUnexpandedParameterPack(NameInfo, UPPC: UPPC_DeclarationType))
6218 return nullptr;
6219
6220 DeclContext *DC = CurContext;
6221 if (D.getCXXScopeSpec().isInvalid())
6222 D.setInvalidType();
6223 else if (D.getCXXScopeSpec().isSet()) {
6224 if (DiagnoseUnexpandedParameterPack(SS: D.getCXXScopeSpec(),
6225 UPPC: UPPC_DeclarationQualifier))
6226 return nullptr;
6227
6228 bool EnteringContext = !D.getDeclSpec().isFriendSpecified();
6229 DC = computeDeclContext(SS: D.getCXXScopeSpec(), EnteringContext);
6230 if (!DC || isa<EnumDecl>(Val: DC)) {
6231 // If we could not compute the declaration context, it's because the
6232 // declaration context is dependent but does not refer to a class,
6233 // class template, or class template partial specialization. Complain
6234 // and return early, to avoid the coming semantic disaster.
6235 Diag(Loc: D.getIdentifierLoc(),
6236 DiagID: diag::err_template_qualified_declarator_no_match)
6237 << D.getCXXScopeSpec().getScopeRep()
6238 << D.getCXXScopeSpec().getRange();
6239 return nullptr;
6240 }
6241 bool IsDependentContext = DC->isDependentContext();
6242
6243 if (!IsDependentContext &&
6244 RequireCompleteDeclContext(SS&: D.getCXXScopeSpec(), DC))
6245 return nullptr;
6246
6247 // If a class is incomplete, do not parse entities inside it.
6248 if (isa<CXXRecordDecl>(Val: DC) && !cast<CXXRecordDecl>(Val: DC)->hasDefinition()) {
6249 Diag(Loc: D.getIdentifierLoc(),
6250 DiagID: diag::err_member_def_undefined_record)
6251 << Name << DC << D.getCXXScopeSpec().getRange();
6252 return nullptr;
6253 }
6254 if (!D.getDeclSpec().isFriendSpecified()) {
6255 TemplateIdAnnotation *TemplateId =
6256 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
6257 ? D.getName().TemplateId
6258 : nullptr;
6259 if (diagnoseQualifiedDeclaration(SS&: D.getCXXScopeSpec(), DC, Name,
6260 Loc: D.getIdentifierLoc(), TemplateId,
6261 /*IsMemberSpecialization=*/false)) {
6262 if (DC->isRecord())
6263 return nullptr;
6264
6265 D.setInvalidType();
6266 }
6267 }
6268
6269 // Check whether we need to rebuild the type of the given
6270 // declaration in the current instantiation.
6271 if (EnteringContext && IsDependentContext &&
6272 TemplateParamLists.size() != 0) {
6273 ContextRAII SavedContext(*this, DC);
6274 if (RebuildDeclaratorInCurrentInstantiation(S&: *this, D, Name))
6275 D.setInvalidType();
6276 }
6277 }
6278
6279 TypeSourceInfo *TInfo = GetTypeForDeclarator(D);
6280 QualType R = TInfo->getType();
6281
6282 if (DiagnoseUnexpandedParameterPack(Loc: D.getIdentifierLoc(), T: TInfo,
6283 UPPC: UPPC_DeclarationType))
6284 D.setInvalidType();
6285
6286 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
6287 forRedeclarationInCurContext());
6288
6289 // See if this is a redefinition of a variable in the same scope.
6290 if (!D.getCXXScopeSpec().isSet()) {
6291 bool IsLinkageLookup = false;
6292 bool CreateBuiltins = false;
6293
6294 // If the declaration we're planning to build will be a function
6295 // or object with linkage, then look for another declaration with
6296 // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6).
6297 //
6298 // If the declaration we're planning to build will be declared with
6299 // external linkage in the translation unit, create any builtin with
6300 // the same name.
6301 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef)
6302 /* Do nothing*/;
6303 else if (CurContext->isFunctionOrMethod() &&
6304 (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern ||
6305 R->isFunctionType())) {
6306 IsLinkageLookup = true;
6307 CreateBuiltins =
6308 CurContext->getEnclosingNamespaceContext()->isTranslationUnit();
6309 } else if (CurContext->getRedeclContext()->isTranslationUnit() &&
6310 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static)
6311 CreateBuiltins = true;
6312
6313 if (IsLinkageLookup) {
6314 Previous.clear(Kind: LookupRedeclarationWithLinkage);
6315 Previous.setRedeclarationKind(
6316 RedeclarationKind::ForExternalRedeclaration);
6317 }
6318
6319 LookupName(R&: Previous, S, AllowBuiltinCreation: CreateBuiltins);
6320 } else { // Something like "int foo::x;"
6321 LookupQualifiedName(R&: Previous, LookupCtx: DC);
6322
6323 // C++ [dcl.meaning]p1:
6324 // When the declarator-id is qualified, the declaration shall refer to a
6325 // previously declared member of the class or namespace to which the
6326 // qualifier refers (or, in the case of a namespace, of an element of the
6327 // inline namespace set of that namespace (7.3.1)) or to a specialization
6328 // thereof; [...]
6329 //
6330 // Note that we already checked the context above, and that we do not have
6331 // enough information to make sure that Previous contains the declaration
6332 // we want to match. For example, given:
6333 //
6334 // class X {
6335 // void f();
6336 // void f(float);
6337 // };
6338 //
6339 // void X::f(int) { } // ill-formed
6340 //
6341 // In this case, Previous will point to the overload set
6342 // containing the two f's declared in X, but neither of them
6343 // matches.
6344
6345 RemoveUsingDecls(R&: Previous);
6346 }
6347
6348 if (auto *TPD = Previous.getAsSingle<NamedDecl>();
6349 TPD && TPD->isTemplateParameter()) {
6350 // Older versions of clang allowed the names of function/variable templates
6351 // to shadow the names of their template parameters. For the compatibility
6352 // purposes we detect such cases and issue a default-to-error warning that
6353 // can be disabled with -Wno-strict-primary-template-shadow.
6354 if (!D.isInvalidType()) {
6355 bool AllowForCompatibility = false;
6356 if (Scope *DeclParent = S->getDeclParent();
6357 Scope *TemplateParamParent = S->getTemplateParamParent()) {
6358 AllowForCompatibility = DeclParent->Contains(rhs: *TemplateParamParent) &&
6359 TemplateParamParent->isDeclScope(D: TPD);
6360 }
6361 DiagnoseTemplateParameterShadow(Loc: D.getIdentifierLoc(), PrevDecl: TPD,
6362 SupportedForCompatibility: AllowForCompatibility);
6363 }
6364
6365 // Just pretend that we didn't see the previous declaration.
6366 Previous.clear();
6367 }
6368
6369 if (!R->isFunctionType() && DiagnoseClassNameShadow(DC, NameInfo))
6370 // Forget that the previous declaration is the injected-class-name.
6371 Previous.clear();
6372
6373 // In C++, the previous declaration we find might be a tag type
6374 // (class or enum). In this case, the new declaration will hide the
6375 // tag type. Note that this applies to functions, function templates, and
6376 // variables, but not to typedefs (C++ [dcl.typedef]p4) or variable templates.
6377 if (Previous.isSingleTagDecl() &&
6378 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
6379 (TemplateParamLists.size() == 0 || R->isFunctionType()))
6380 Previous.clear();
6381
6382 // Check that there are no default arguments other than in the parameters
6383 // of a function declaration (C++ only).
6384 if (getLangOpts().CPlusPlus)
6385 CheckExtraCXXDefaultArguments(D);
6386
6387 /// Get the innermost enclosing declaration scope.
6388 S = S->getDeclParent();
6389
6390 NamedDecl *New;
6391
6392 bool AddToScope = true;
6393 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
6394 if (TemplateParamLists.size()) {
6395 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_template_typedef);
6396 return nullptr;
6397 }
6398
6399 New = ActOnTypedefDeclarator(S, D, DC, TInfo, Previous);
6400 } else if (R->isFunctionType()) {
6401 New = ActOnFunctionDeclarator(S, D, DC, TInfo, Previous,
6402 TemplateParamLists,
6403 AddToScope);
6404 } else {
6405 New = ActOnVariableDeclarator(S, D, DC, TInfo, Previous, TemplateParamLists,
6406 AddToScope);
6407 }
6408
6409 if (!New)
6410 return nullptr;
6411
6412 // If this has an identifier and is not a function template specialization,
6413 // add it to the scope stack.
6414 if (New->getDeclName() && AddToScope)
6415 PushOnScopeChains(D: New, S);
6416
6417 if (OpenMP().isInOpenMPDeclareTargetContext())
6418 OpenMP().checkDeclIsAllowedInOpenMPTarget(E: nullptr, D: New);
6419
6420 return New;
6421}
6422
6423/// Helper method to turn variable array types into constant array
6424/// types in certain situations which would otherwise be errors (for
6425/// GCC compatibility).
6426static QualType TryToFixInvalidVariablyModifiedType(QualType T,
6427 ASTContext &Context,
6428 bool &SizeIsNegative,
6429 llvm::APSInt &Oversized) {
6430 // This method tries to turn a variable array into a constant
6431 // array even when the size isn't an ICE. This is necessary
6432 // for compatibility with code that depends on gcc's buggy
6433 // constant expression folding, like struct {char x[(int)(char*)2];}
6434 SizeIsNegative = false;
6435 Oversized = 0;
6436
6437 if (T->isDependentType())
6438 return QualType();
6439
6440 QualifierCollector Qs;
6441 const Type *Ty = Qs.strip(type: T);
6442
6443 if (const PointerType* PTy = dyn_cast<PointerType>(Val: Ty)) {
6444 QualType Pointee = PTy->getPointeeType();
6445 QualType FixedType =
6446 TryToFixInvalidVariablyModifiedType(T: Pointee, Context, SizeIsNegative,
6447 Oversized);
6448 if (FixedType.isNull()) return FixedType;
6449 FixedType = Context.getPointerType(T: FixedType);
6450 return Qs.apply(Context, QT: FixedType);
6451 }
6452 if (const ParenType* PTy = dyn_cast<ParenType>(Val: Ty)) {
6453 QualType Inner = PTy->getInnerType();
6454 QualType FixedType =
6455 TryToFixInvalidVariablyModifiedType(T: Inner, Context, SizeIsNegative,
6456 Oversized);
6457 if (FixedType.isNull()) return FixedType;
6458 FixedType = Context.getParenType(NamedType: FixedType);
6459 return Qs.apply(Context, QT: FixedType);
6460 }
6461
6462 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(Val&: T);
6463 if (!VLATy)
6464 return QualType();
6465
6466 QualType ElemTy = VLATy->getElementType();
6467 if (ElemTy->isVariablyModifiedType()) {
6468 ElemTy = TryToFixInvalidVariablyModifiedType(T: ElemTy, Context,
6469 SizeIsNegative, Oversized);
6470 if (ElemTy.isNull())
6471 return QualType();
6472 }
6473
6474 Expr::EvalResult Result;
6475 if (!VLATy->getSizeExpr() ||
6476 !VLATy->getSizeExpr()->EvaluateAsInt(Result, Ctx: Context))
6477 return QualType();
6478
6479 llvm::APSInt Res = Result.Val.getInt();
6480
6481 // Check whether the array size is negative.
6482 if (Res.isSigned() && Res.isNegative()) {
6483 SizeIsNegative = true;
6484 return QualType();
6485 }
6486
6487 // Check whether the array is too large to be addressed.
6488 unsigned ActiveSizeBits =
6489 (!ElemTy->isDependentType() && !ElemTy->isVariablyModifiedType() &&
6490 !ElemTy->isIncompleteType() && !ElemTy->isUndeducedType())
6491 ? ConstantArrayType::getNumAddressingBits(Context, ElementType: ElemTy, NumElements: Res)
6492 : Res.getActiveBits();
6493 if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
6494 Oversized = Res;
6495 return QualType();
6496 }
6497
6498 QualType FoldedArrayType = Context.getConstantArrayType(
6499 EltTy: ElemTy, ArySize: Res, SizeExpr: VLATy->getSizeExpr(), ASM: ArraySizeModifier::Normal, IndexTypeQuals: 0);
6500 return Qs.apply(Context, QT: FoldedArrayType);
6501}
6502
6503static void
6504FixInvalidVariablyModifiedTypeLoc(TypeLoc SrcTL, TypeLoc DstTL) {
6505 SrcTL = SrcTL.getUnqualifiedLoc();
6506 DstTL = DstTL.getUnqualifiedLoc();
6507 if (PointerTypeLoc SrcPTL = SrcTL.getAs<PointerTypeLoc>()) {
6508 PointerTypeLoc DstPTL = DstTL.castAs<PointerTypeLoc>();
6509 FixInvalidVariablyModifiedTypeLoc(SrcTL: SrcPTL.getPointeeLoc(),
6510 DstTL: DstPTL.getPointeeLoc());
6511 DstPTL.setStarLoc(SrcPTL.getStarLoc());
6512 return;
6513 }
6514 if (ParenTypeLoc SrcPTL = SrcTL.getAs<ParenTypeLoc>()) {
6515 ParenTypeLoc DstPTL = DstTL.castAs<ParenTypeLoc>();
6516 FixInvalidVariablyModifiedTypeLoc(SrcTL: SrcPTL.getInnerLoc(),
6517 DstTL: DstPTL.getInnerLoc());
6518 DstPTL.setLParenLoc(SrcPTL.getLParenLoc());
6519 DstPTL.setRParenLoc(SrcPTL.getRParenLoc());
6520 return;
6521 }
6522 ArrayTypeLoc SrcATL = SrcTL.castAs<ArrayTypeLoc>();
6523 ArrayTypeLoc DstATL = DstTL.castAs<ArrayTypeLoc>();
6524 TypeLoc SrcElemTL = SrcATL.getElementLoc();
6525 TypeLoc DstElemTL = DstATL.getElementLoc();
6526 if (VariableArrayTypeLoc SrcElemATL =
6527 SrcElemTL.getAs<VariableArrayTypeLoc>()) {
6528 ConstantArrayTypeLoc DstElemATL = DstElemTL.castAs<ConstantArrayTypeLoc>();
6529 FixInvalidVariablyModifiedTypeLoc(SrcTL: SrcElemATL, DstTL: DstElemATL);
6530 } else {
6531 DstElemTL.initializeFullCopy(Other: SrcElemTL);
6532 }
6533 DstATL.setLBracketLoc(SrcATL.getLBracketLoc());
6534 DstATL.setSizeExpr(SrcATL.getSizeExpr());
6535 DstATL.setRBracketLoc(SrcATL.getRBracketLoc());
6536}
6537
6538/// Helper method to turn variable array types into constant array
6539/// types in certain situations which would otherwise be errors (for
6540/// GCC compatibility).
6541static TypeSourceInfo*
6542TryToFixInvalidVariablyModifiedTypeSourceInfo(TypeSourceInfo *TInfo,
6543 ASTContext &Context,
6544 bool &SizeIsNegative,
6545 llvm::APSInt &Oversized) {
6546 QualType FixedTy
6547 = TryToFixInvalidVariablyModifiedType(T: TInfo->getType(), Context,
6548 SizeIsNegative, Oversized);
6549 if (FixedTy.isNull())
6550 return nullptr;
6551 TypeSourceInfo *FixedTInfo = Context.getTrivialTypeSourceInfo(T: FixedTy);
6552 FixInvalidVariablyModifiedTypeLoc(SrcTL: TInfo->getTypeLoc(),
6553 DstTL: FixedTInfo->getTypeLoc());
6554 return FixedTInfo;
6555}
6556
6557bool Sema::tryToFixVariablyModifiedVarType(TypeSourceInfo *&TInfo,
6558 QualType &T, SourceLocation Loc,
6559 unsigned FailedFoldDiagID) {
6560 bool SizeIsNegative;
6561 llvm::APSInt Oversized;
6562 TypeSourceInfo *FixedTInfo = TryToFixInvalidVariablyModifiedTypeSourceInfo(
6563 TInfo, Context, SizeIsNegative, Oversized);
6564 if (FixedTInfo) {
6565 Diag(Loc, DiagID: diag::ext_vla_folded_to_constant);
6566 TInfo = FixedTInfo;
6567 T = FixedTInfo->getType();
6568 return true;
6569 }
6570
6571 if (SizeIsNegative)
6572 Diag(Loc, DiagID: diag::err_typecheck_negative_array_size);
6573 else if (Oversized.getBoolValue())
6574 Diag(Loc, DiagID: diag::err_array_too_large) << toString(I: Oversized, Radix: 10);
6575 else if (FailedFoldDiagID)
6576 Diag(Loc, DiagID: FailedFoldDiagID);
6577 return false;
6578}
6579
6580void
6581Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, Scope *S) {
6582 if (!getLangOpts().CPlusPlus &&
6583 ND->getLexicalDeclContext()->getRedeclContext()->isTranslationUnit())
6584 // Don't need to track declarations in the TU in C.
6585 return;
6586
6587 // Note that we have a locally-scoped external with this name.
6588 Context.getExternCContextDecl()->makeDeclVisibleInContext(D: ND);
6589}
6590
6591NamedDecl *Sema::findLocallyScopedExternCDecl(DeclarationName Name) {
6592 // FIXME: We can have multiple results via __attribute__((overloadable)).
6593 auto Result = Context.getExternCContextDecl()->lookup(Name);
6594 return Result.empty() ? nullptr : *Result.begin();
6595}
6596
6597void Sema::DiagnoseFunctionSpecifiers(const DeclSpec &DS) {
6598 // FIXME: We should probably indicate the identifier in question to avoid
6599 // confusion for constructs like "virtual int a(), b;"
6600 if (DS.isVirtualSpecified())
6601 Diag(Loc: DS.getVirtualSpecLoc(),
6602 DiagID: diag::err_virtual_non_function);
6603
6604 if (DS.hasExplicitSpecifier())
6605 Diag(Loc: DS.getExplicitSpecLoc(),
6606 DiagID: diag::err_explicit_non_function);
6607
6608 if (DS.isNoreturnSpecified())
6609 Diag(Loc: DS.getNoreturnSpecLoc(),
6610 DiagID: diag::err_noreturn_non_function);
6611}
6612
6613NamedDecl*
6614Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC,
6615 TypeSourceInfo *TInfo, LookupResult &Previous) {
6616 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1).
6617 if (D.getCXXScopeSpec().isSet()) {
6618 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_qualified_typedef_declarator)
6619 << D.getCXXScopeSpec().getRange();
6620 D.setInvalidType();
6621 // Pretend we didn't see the scope specifier.
6622 DC = CurContext;
6623 Previous.clear();
6624 }
6625
6626 DiagnoseFunctionSpecifiers(DS: D.getDeclSpec());
6627
6628 if (D.getDeclSpec().isInlineSpecified())
6629 Diag(Loc: D.getDeclSpec().getInlineSpecLoc(), DiagID: diag::err_inline_non_function)
6630 << getLangOpts().CPlusPlus17;
6631 if (D.getDeclSpec().hasConstexprSpecifier())
6632 Diag(Loc: D.getDeclSpec().getConstexprSpecLoc(), DiagID: diag::err_invalid_constexpr)
6633 << 1 << static_cast<int>(D.getDeclSpec().getConstexprSpecifier());
6634
6635 if (D.getName().getKind() != UnqualifiedIdKind::IK_Identifier) {
6636 if (D.getName().getKind() == UnqualifiedIdKind::IK_DeductionGuideName)
6637 Diag(Loc: D.getName().StartLocation,
6638 DiagID: diag::err_deduction_guide_invalid_specifier)
6639 << "typedef";
6640 else
6641 Diag(Loc: D.getName().StartLocation, DiagID: diag::err_typedef_not_identifier)
6642 << D.getName().getSourceRange();
6643 return nullptr;
6644 }
6645
6646 TypedefDecl *NewTD = ParseTypedefDecl(S, D, T: TInfo->getType(), TInfo);
6647 if (!NewTD) return nullptr;
6648
6649 // Handle attributes prior to checking for duplicates in MergeVarDecl
6650 ProcessDeclAttributes(S, D: NewTD, PD: D);
6651
6652 CheckTypedefForVariablyModifiedType(S, D: NewTD);
6653
6654 bool Redeclaration = D.isRedeclaration();
6655 NamedDecl *ND = ActOnTypedefNameDecl(S, DC, D: NewTD, Previous, Redeclaration);
6656 D.setRedeclaration(Redeclaration);
6657 return ND;
6658}
6659
6660void
6661Sema::CheckTypedefForVariablyModifiedType(Scope *S, TypedefNameDecl *NewTD) {
6662 // C99 6.7.7p2: If a typedef name specifies a variably modified type
6663 // then it shall have block scope.
6664 // Note that variably modified types must be fixed before merging the decl so
6665 // that redeclarations will match.
6666 TypeSourceInfo *TInfo = NewTD->getTypeSourceInfo();
6667 QualType T = TInfo->getType();
6668 if (T->isVariablyModifiedType()) {
6669 setFunctionHasBranchProtectedScope();
6670
6671 if (S->getFnParent() == nullptr) {
6672 bool SizeIsNegative;
6673 llvm::APSInt Oversized;
6674 TypeSourceInfo *FixedTInfo =
6675 TryToFixInvalidVariablyModifiedTypeSourceInfo(TInfo, Context,
6676 SizeIsNegative,
6677 Oversized);
6678 if (FixedTInfo) {
6679 Diag(Loc: NewTD->getLocation(), DiagID: diag::ext_vla_folded_to_constant);
6680 NewTD->setTypeSourceInfo(FixedTInfo);
6681 } else {
6682 if (SizeIsNegative)
6683 Diag(Loc: NewTD->getLocation(), DiagID: diag::err_typecheck_negative_array_size);
6684 else if (T->isVariableArrayType())
6685 Diag(Loc: NewTD->getLocation(), DiagID: diag::err_vla_decl_in_file_scope);
6686 else if (Oversized.getBoolValue())
6687 Diag(Loc: NewTD->getLocation(), DiagID: diag::err_array_too_large)
6688 << toString(I: Oversized, Radix: 10);
6689 else
6690 Diag(Loc: NewTD->getLocation(), DiagID: diag::err_vm_decl_in_file_scope);
6691 NewTD->setInvalidDecl();
6692 }
6693 }
6694 }
6695}
6696
6697NamedDecl*
6698Sema::ActOnTypedefNameDecl(Scope *S, DeclContext *DC, TypedefNameDecl *NewTD,
6699 LookupResult &Previous, bool &Redeclaration) {
6700
6701 // Find the shadowed declaration before filtering for scope.
6702 NamedDecl *ShadowedDecl = getShadowedDeclaration(D: NewTD, R: Previous);
6703
6704 // Merge the decl with the existing one if appropriate. If the decl is
6705 // in an outer scope, it isn't the same thing.
6706 FilterLookupForScope(R&: Previous, Ctx: DC, S, /*ConsiderLinkage*/false,
6707 /*AllowInlineNamespace*/false);
6708 filterNonConflictingPreviousTypedefDecls(S&: *this, Decl: NewTD, Previous);
6709 if (!Previous.empty()) {
6710 Redeclaration = true;
6711 MergeTypedefNameDecl(S, New: NewTD, OldDecls&: Previous);
6712 } else {
6713 inferGslPointerAttribute(TD: NewTD);
6714 }
6715
6716 if (ShadowedDecl && !Redeclaration)
6717 CheckShadow(D: NewTD, ShadowedDecl, R: Previous);
6718
6719 // If this is the C FILE type, notify the AST context.
6720 if (IdentifierInfo *II = NewTD->getIdentifier())
6721 if (!NewTD->isInvalidDecl() &&
6722 NewTD->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
6723 switch (II->getNotableIdentifierID()) {
6724 case tok::NotableIdentifierKind::FILE:
6725 Context.setFILEDecl(NewTD);
6726 break;
6727 case tok::NotableIdentifierKind::jmp_buf:
6728 Context.setjmp_bufDecl(NewTD);
6729 break;
6730 case tok::NotableIdentifierKind::sigjmp_buf:
6731 Context.setsigjmp_bufDecl(NewTD);
6732 break;
6733 case tok::NotableIdentifierKind::ucontext_t:
6734 Context.setucontext_tDecl(NewTD);
6735 break;
6736 case tok::NotableIdentifierKind::float_t:
6737 case tok::NotableIdentifierKind::double_t:
6738 NewTD->addAttr(A: AvailableOnlyInDefaultEvalMethodAttr::Create(Ctx&: Context));
6739 break;
6740 default:
6741 break;
6742 }
6743 }
6744
6745 return NewTD;
6746}
6747
6748/// Determines whether the given declaration is an out-of-scope
6749/// previous declaration.
6750///
6751/// This routine should be invoked when name lookup has found a
6752/// previous declaration (PrevDecl) that is not in the scope where a
6753/// new declaration by the same name is being introduced. If the new
6754/// declaration occurs in a local scope, previous declarations with
6755/// linkage may still be considered previous declarations (C99
6756/// 6.2.2p4-5, C++ [basic.link]p6).
6757///
6758/// \param PrevDecl the previous declaration found by name
6759/// lookup
6760///
6761/// \param DC the context in which the new declaration is being
6762/// declared.
6763///
6764/// \returns true if PrevDecl is an out-of-scope previous declaration
6765/// for a new delcaration with the same name.
6766static bool
6767isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC,
6768 ASTContext &Context) {
6769 if (!PrevDecl)
6770 return false;
6771
6772 if (!PrevDecl->hasLinkage())
6773 return false;
6774
6775 if (Context.getLangOpts().CPlusPlus) {
6776 // C++ [basic.link]p6:
6777 // If there is a visible declaration of an entity with linkage
6778 // having the same name and type, ignoring entities declared
6779 // outside the innermost enclosing namespace scope, the block
6780 // scope declaration declares that same entity and receives the
6781 // linkage of the previous declaration.
6782 DeclContext *OuterContext = DC->getRedeclContext();
6783 if (!OuterContext->isFunctionOrMethod())
6784 // This rule only applies to block-scope declarations.
6785 return false;
6786
6787 DeclContext *PrevOuterContext = PrevDecl->getDeclContext();
6788 if (PrevOuterContext->isRecord())
6789 // We found a member function: ignore it.
6790 return false;
6791
6792 // Find the innermost enclosing namespace for the new and
6793 // previous declarations.
6794 OuterContext = OuterContext->getEnclosingNamespaceContext();
6795 PrevOuterContext = PrevOuterContext->getEnclosingNamespaceContext();
6796
6797 // The previous declaration is in a different namespace, so it
6798 // isn't the same function.
6799 if (!OuterContext->Equals(DC: PrevOuterContext))
6800 return false;
6801 }
6802
6803 return true;
6804}
6805
6806static void SetNestedNameSpecifier(Sema &S, DeclaratorDecl *DD, Declarator &D) {
6807 CXXScopeSpec &SS = D.getCXXScopeSpec();
6808 if (!SS.isSet()) return;
6809 DD->setQualifierInfo(SS.getWithLocInContext(Context&: S.Context));
6810}
6811
6812void Sema::deduceOpenCLAddressSpace(ValueDecl *Decl) {
6813 if (Decl->getType().hasAddressSpace())
6814 return;
6815 if (Decl->getType()->isDependentType())
6816 return;
6817 if (VarDecl *Var = dyn_cast<VarDecl>(Val: Decl)) {
6818 QualType Type = Var->getType();
6819 if (Type->isSamplerT() || Type->isVoidType())
6820 return;
6821 LangAS ImplAS = LangAS::opencl_private;
6822 // OpenCL C v3.0 s6.7.8 - For OpenCL C 2.0 or with the
6823 // __opencl_c_program_scope_global_variables feature, the address space
6824 // for a variable at program scope or a static or extern variable inside
6825 // a function are inferred to be __global.
6826 if (getOpenCLOptions().areProgramScopeVariablesSupported(Opts: getLangOpts()) &&
6827 Var->hasGlobalStorage())
6828 ImplAS = LangAS::opencl_global;
6829 // If the original type from a decayed type is an array type and that array
6830 // type has no address space yet, deduce it now.
6831 if (auto DT = dyn_cast<DecayedType>(Val&: Type)) {
6832 auto OrigTy = DT->getOriginalType();
6833 if (!OrigTy.hasAddressSpace() && OrigTy->isArrayType()) {
6834 // Add the address space to the original array type and then propagate
6835 // that to the element type through `getAsArrayType`.
6836 OrigTy = Context.getAddrSpaceQualType(T: OrigTy, AddressSpace: ImplAS);
6837 OrigTy = QualType(Context.getAsArrayType(T: OrigTy), 0);
6838 // Re-generate the decayed type.
6839 Type = Context.getDecayedType(T: OrigTy);
6840 }
6841 }
6842 Type = Context.getAddrSpaceQualType(T: Type, AddressSpace: ImplAS);
6843 // Apply any qualifiers (including address space) from the array type to
6844 // the element type. This implements C99 6.7.3p8: "If the specification of
6845 // an array type includes any type qualifiers, the element type is so
6846 // qualified, not the array type."
6847 if (Type->isArrayType())
6848 Type = QualType(Context.getAsArrayType(T: Type), 0);
6849 Decl->setType(Type);
6850 }
6851}
6852
6853static void checkAttributesAfterMerging(Sema &S, NamedDecl &ND) {
6854 // Ensure that an auto decl is deduced otherwise the checks below might cache
6855 // the wrong linkage.
6856 assert(S.ParsingInitForAutoVars.count(&ND) == 0);
6857
6858 // 'weak' only applies to declarations with external linkage.
6859 if (WeakAttr *Attr = ND.getAttr<WeakAttr>()) {
6860 if (!ND.isExternallyVisible()) {
6861 S.Diag(Loc: Attr->getLocation(), DiagID: diag::err_attribute_weak_static);
6862 ND.dropAttr<WeakAttr>();
6863 }
6864 }
6865 if (WeakRefAttr *Attr = ND.getAttr<WeakRefAttr>()) {
6866 if (ND.isExternallyVisible()) {
6867 S.Diag(Loc: Attr->getLocation(), DiagID: diag::err_attribute_weakref_not_static);
6868 ND.dropAttrs<WeakRefAttr, AliasAttr>();
6869 }
6870 }
6871
6872 if (auto *VD = dyn_cast<VarDecl>(Val: &ND)) {
6873 if (VD->hasInit()) {
6874 if (const auto *Attr = VD->getAttr<AliasAttr>()) {
6875 assert(VD->isThisDeclarationADefinition() &&
6876 !VD->isExternallyVisible() && "Broken AliasAttr handled late!");
6877 S.Diag(Loc: Attr->getLocation(), DiagID: diag::err_alias_is_definition) << VD << 0;
6878 VD->dropAttr<AliasAttr>();
6879 }
6880 }
6881 }
6882
6883 // 'selectany' only applies to externally visible variable declarations.
6884 // It does not apply to functions.
6885 if (SelectAnyAttr *Attr = ND.getAttr<SelectAnyAttr>()) {
6886 if (isa<FunctionDecl>(Val: ND) || !ND.isExternallyVisible()) {
6887 S.Diag(Loc: Attr->getLocation(),
6888 DiagID: diag::err_attribute_selectany_non_extern_data);
6889 ND.dropAttr<SelectAnyAttr>();
6890 }
6891 }
6892
6893 if (HybridPatchableAttr *Attr = ND.getAttr<HybridPatchableAttr>()) {
6894 if (!ND.isExternallyVisible())
6895 S.Diag(Loc: Attr->getLocation(),
6896 DiagID: diag::warn_attribute_hybrid_patchable_non_extern);
6897 }
6898 if (const InheritableAttr *Attr = getDLLAttr(D: &ND)) {
6899 auto *VD = dyn_cast<VarDecl>(Val: &ND);
6900 bool IsAnonymousNS = false;
6901 bool IsMicrosoft = S.Context.getTargetInfo().getCXXABI().isMicrosoft();
6902 if (VD) {
6903 const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(Val: VD->getDeclContext());
6904 while (NS && !IsAnonymousNS) {
6905 IsAnonymousNS = NS->isAnonymousNamespace();
6906 NS = dyn_cast<NamespaceDecl>(Val: NS->getParent());
6907 }
6908 }
6909 // dll attributes require external linkage. Static locals may have external
6910 // linkage but still cannot be explicitly imported or exported.
6911 // In Microsoft mode, a variable defined in anonymous namespace must have
6912 // external linkage in order to be exported.
6913 bool AnonNSInMicrosoftMode = IsAnonymousNS && IsMicrosoft;
6914 if ((ND.isExternallyVisible() && AnonNSInMicrosoftMode) ||
6915 (!AnonNSInMicrosoftMode &&
6916 (!ND.isExternallyVisible() || (VD && VD->isStaticLocal())))) {
6917 S.Diag(Loc: ND.getLocation(), DiagID: diag::err_attribute_dll_not_extern)
6918 << &ND << Attr;
6919 ND.setInvalidDecl();
6920 }
6921 }
6922
6923 // Check the attributes on the function type, if any.
6924 if (const auto *FD = dyn_cast<FunctionDecl>(Val: &ND)) {
6925 // Don't declare this variable in the second operand of the for-statement;
6926 // GCC miscompiles that by ending its lifetime before evaluating the
6927 // third operand. See gcc.gnu.org/PR86769.
6928 AttributedTypeLoc ATL;
6929 for (TypeLoc TL = FD->getTypeSourceInfo()->getTypeLoc();
6930 (ATL = TL.getAsAdjusted<AttributedTypeLoc>());
6931 TL = ATL.getModifiedLoc()) {
6932 // The [[lifetimebound]] attribute can be applied to the implicit object
6933 // parameter of a non-static member function (other than a ctor or dtor)
6934 // by applying it to the function type.
6935 if (const auto *A = ATL.getAttrAs<LifetimeBoundAttr>()) {
6936 const auto *MD = dyn_cast<CXXMethodDecl>(Val: FD);
6937 if (!MD || MD->isStatic()) {
6938 S.Diag(Loc: A->getLocation(), DiagID: diag::err_lifetimebound_no_object_param)
6939 << !MD << A->getRange();
6940 } else if (isa<CXXConstructorDecl>(Val: MD) || isa<CXXDestructorDecl>(Val: MD)) {
6941 S.Diag(Loc: A->getLocation(), DiagID: diag::err_lifetimebound_ctor_dtor)
6942 << isa<CXXDestructorDecl>(Val: MD) << A->getRange();
6943 }
6944 }
6945 }
6946 }
6947}
6948
6949static void checkDLLAttributeRedeclaration(Sema &S, NamedDecl *OldDecl,
6950 NamedDecl *NewDecl,
6951 bool IsSpecialization,
6952 bool IsDefinition) {
6953 if (OldDecl->isInvalidDecl() || NewDecl->isInvalidDecl())
6954 return;
6955
6956 bool IsTemplate = false;
6957 if (TemplateDecl *OldTD = dyn_cast<TemplateDecl>(Val: OldDecl)) {
6958 OldDecl = OldTD->getTemplatedDecl();
6959 IsTemplate = true;
6960 if (!IsSpecialization)
6961 IsDefinition = false;
6962 }
6963 if (TemplateDecl *NewTD = dyn_cast<TemplateDecl>(Val: NewDecl)) {
6964 NewDecl = NewTD->getTemplatedDecl();
6965 IsTemplate = true;
6966 }
6967
6968 if (!OldDecl || !NewDecl)
6969 return;
6970
6971 const DLLImportAttr *OldImportAttr = OldDecl->getAttr<DLLImportAttr>();
6972 const DLLExportAttr *OldExportAttr = OldDecl->getAttr<DLLExportAttr>();
6973 const DLLImportAttr *NewImportAttr = NewDecl->getAttr<DLLImportAttr>();
6974 const DLLExportAttr *NewExportAttr = NewDecl->getAttr<DLLExportAttr>();
6975
6976 // dllimport and dllexport are inheritable attributes so we have to exclude
6977 // inherited attribute instances.
6978 bool HasNewAttr = (NewImportAttr && !NewImportAttr->isInherited()) ||
6979 (NewExportAttr && !NewExportAttr->isInherited());
6980
6981 // A redeclaration is not allowed to add a dllimport or dllexport attribute,
6982 // the only exception being explicit specializations.
6983 // Implicitly generated declarations are also excluded for now because there
6984 // is no other way to switch these to use dllimport or dllexport.
6985 bool AddsAttr = !(OldImportAttr || OldExportAttr) && HasNewAttr;
6986
6987 if (AddsAttr && !IsSpecialization && !OldDecl->isImplicit()) {
6988 // Allow with a warning for free functions and global variables.
6989 bool JustWarn = false;
6990 if (!OldDecl->isCXXClassMember()) {
6991 auto *VD = dyn_cast<VarDecl>(Val: OldDecl);
6992 if (VD && !VD->getDescribedVarTemplate())
6993 JustWarn = true;
6994 auto *FD = dyn_cast<FunctionDecl>(Val: OldDecl);
6995 if (FD && FD->getTemplatedKind() == FunctionDecl::TK_NonTemplate)
6996 JustWarn = true;
6997 }
6998
6999 // We cannot change a declaration that's been used because IR has already
7000 // been emitted. Dllimported functions will still work though (modulo
7001 // address equality) as they can use the thunk.
7002 if (OldDecl->isUsed())
7003 if (!isa<FunctionDecl>(Val: OldDecl) || !NewImportAttr)
7004 JustWarn = false;
7005
7006 unsigned DiagID = JustWarn ? diag::warn_attribute_dll_redeclaration
7007 : diag::err_attribute_dll_redeclaration;
7008 S.Diag(Loc: NewDecl->getLocation(), DiagID)
7009 << NewDecl
7010 << (NewImportAttr ? (const Attr *)NewImportAttr : NewExportAttr);
7011 S.Diag(Loc: OldDecl->getLocation(), DiagID: diag::note_previous_declaration);
7012 if (!JustWarn) {
7013 NewDecl->setInvalidDecl();
7014 return;
7015 }
7016 }
7017
7018 // A redeclaration is not allowed to drop a dllimport attribute, the only
7019 // exceptions being inline function definitions (except for function
7020 // templates), local extern declarations, qualified friend declarations or
7021 // special MSVC extension: in the last case, the declaration is treated as if
7022 // it were marked dllexport.
7023 bool IsInline = false, IsStaticDataMember = false, IsQualifiedFriend = false;
7024 bool IsMicrosoftABI = S.Context.getTargetInfo().shouldDLLImportComdatSymbols();
7025 if (const auto *VD = dyn_cast<VarDecl>(Val: NewDecl)) {
7026 // Ignore static data because out-of-line definitions are diagnosed
7027 // separately.
7028 IsStaticDataMember = VD->isStaticDataMember();
7029 IsDefinition = VD->isThisDeclarationADefinition(S.Context) !=
7030 VarDecl::DeclarationOnly;
7031 } else if (const auto *FD = dyn_cast<FunctionDecl>(Val: NewDecl)) {
7032 IsInline = FD->isInlined();
7033 IsQualifiedFriend = FD->getQualifier() &&
7034 FD->getFriendObjectKind() == Decl::FOK_Declared;
7035 }
7036
7037 if (OldImportAttr && !HasNewAttr &&
7038 (!IsInline || (IsMicrosoftABI && IsTemplate)) && !IsStaticDataMember &&
7039 !NewDecl->isLocalExternDecl() && !IsQualifiedFriend) {
7040 if (IsMicrosoftABI && IsDefinition) {
7041 if (IsSpecialization) {
7042 S.Diag(
7043 Loc: NewDecl->getLocation(),
7044 DiagID: diag::err_attribute_dllimport_function_specialization_definition);
7045 S.Diag(Loc: OldImportAttr->getLocation(), DiagID: diag::note_attribute);
7046 NewDecl->dropAttr<DLLImportAttr>();
7047 } else {
7048 S.Diag(Loc: NewDecl->getLocation(),
7049 DiagID: diag::warn_redeclaration_without_import_attribute)
7050 << NewDecl;
7051 S.Diag(Loc: OldDecl->getLocation(), DiagID: diag::note_previous_declaration);
7052 NewDecl->dropAttr<DLLImportAttr>();
7053 NewDecl->addAttr(A: DLLExportAttr::CreateImplicit(
7054 Ctx&: S.Context, Range: NewImportAttr->getRange()));
7055 }
7056 } else if (IsMicrosoftABI && IsSpecialization) {
7057 assert(!IsDefinition);
7058 // MSVC allows this. Keep the inherited attribute.
7059 } else {
7060 S.Diag(Loc: NewDecl->getLocation(),
7061 DiagID: diag::warn_redeclaration_without_attribute_prev_attribute_ignored)
7062 << NewDecl << OldImportAttr;
7063 S.Diag(Loc: OldDecl->getLocation(), DiagID: diag::note_previous_declaration);
7064 S.Diag(Loc: OldImportAttr->getLocation(), DiagID: diag::note_previous_attribute);
7065 OldDecl->dropAttr<DLLImportAttr>();
7066 NewDecl->dropAttr<DLLImportAttr>();
7067 }
7068 } else if (IsInline && OldImportAttr && !IsMicrosoftABI) {
7069 // In MinGW, seeing a function declared inline drops the dllimport
7070 // attribute.
7071 OldDecl->dropAttr<DLLImportAttr>();
7072 NewDecl->dropAttr<DLLImportAttr>();
7073 S.Diag(Loc: NewDecl->getLocation(),
7074 DiagID: diag::warn_dllimport_dropped_from_inline_function)
7075 << NewDecl << OldImportAttr;
7076 }
7077
7078 // A specialization of a class template member function is processed here
7079 // since it's a redeclaration. If the parent class is dllexport, the
7080 // specialization inherits that attribute. This doesn't happen automatically
7081 // since the parent class isn't instantiated until later.
7082 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Val: NewDecl)) {
7083 if (MD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization &&
7084 !NewImportAttr && !NewExportAttr) {
7085 if (const DLLExportAttr *ParentExportAttr =
7086 MD->getParent()->getAttr<DLLExportAttr>()) {
7087 DLLExportAttr *NewAttr = ParentExportAttr->clone(C&: S.Context);
7088 NewAttr->setInherited(true);
7089 NewDecl->addAttr(A: NewAttr);
7090 }
7091 }
7092 }
7093}
7094
7095/// Given that we are within the definition of the given function,
7096/// will that definition behave like C99's 'inline', where the
7097/// definition is discarded except for optimization purposes?
7098static bool isFunctionDefinitionDiscarded(Sema &S, FunctionDecl *FD) {
7099 // Try to avoid calling GetGVALinkageForFunction.
7100
7101 // All cases of this require the 'inline' keyword.
7102 if (!FD->isInlined()) return false;
7103
7104 // This is only possible in C++ with the gnu_inline attribute.
7105 if (S.getLangOpts().CPlusPlus && !FD->hasAttr<GNUInlineAttr>())
7106 return false;
7107
7108 // Okay, go ahead and call the relatively-more-expensive function.
7109 return S.Context.GetGVALinkageForFunction(FD) == GVA_AvailableExternally;
7110}
7111
7112/// Determine whether a variable is extern "C" prior to attaching
7113/// an initializer. We can't just call isExternC() here, because that
7114/// will also compute and cache whether the declaration is externally
7115/// visible, which might change when we attach the initializer.
7116///
7117/// This can only be used if the declaration is known to not be a
7118/// redeclaration of an internal linkage declaration.
7119///
7120/// For instance:
7121///
7122/// auto x = []{};
7123///
7124/// Attaching the initializer here makes this declaration not externally
7125/// visible, because its type has internal linkage.
7126///
7127/// FIXME: This is a hack.
7128template<typename T>
7129static bool isIncompleteDeclExternC(Sema &S, const T *D) {
7130 if (S.getLangOpts().CPlusPlus) {
7131 // In C++, the overloadable attribute negates the effects of extern "C".
7132 if (!D->isInExternCContext() || D->template hasAttr<OverloadableAttr>())
7133 return false;
7134
7135 // So do CUDA's host/device attributes.
7136 if (S.getLangOpts().CUDA && (D->template hasAttr<CUDADeviceAttr>() ||
7137 D->template hasAttr<CUDAHostAttr>()))
7138 return false;
7139 }
7140 return D->isExternC();
7141}
7142
7143static bool shouldConsiderLinkage(const VarDecl *VD) {
7144 const DeclContext *DC = VD->getDeclContext()->getRedeclContext();
7145 if (DC->isFunctionOrMethod() || isa<OMPDeclareReductionDecl>(Val: DC) ||
7146 isa<OMPDeclareMapperDecl>(Val: DC))
7147 return VD->hasExternalStorage();
7148 if (DC->isFileContext())
7149 return true;
7150 if (DC->isRecord())
7151 return false;
7152 if (DC->getDeclKind() == Decl::HLSLBuffer)
7153 return false;
7154
7155 if (isa<RequiresExprBodyDecl>(Val: DC))
7156 return false;
7157 llvm_unreachable("Unexpected context");
7158}
7159
7160static bool shouldConsiderLinkage(const FunctionDecl *FD) {
7161 const DeclContext *DC = FD->getDeclContext()->getRedeclContext();
7162 if (DC->isFileContext() || DC->isFunctionOrMethod() ||
7163 isa<OMPDeclareReductionDecl>(Val: DC) || isa<OMPDeclareMapperDecl>(Val: DC))
7164 return true;
7165 if (DC->isRecord())
7166 return false;
7167 llvm_unreachable("Unexpected context");
7168}
7169
7170static bool hasParsedAttr(Scope *S, const Declarator &PD,
7171 ParsedAttr::Kind Kind) {
7172 // Check decl attributes on the DeclSpec.
7173 if (PD.getDeclSpec().getAttributes().hasAttribute(K: Kind))
7174 return true;
7175
7176 // Walk the declarator structure, checking decl attributes that were in a type
7177 // position to the decl itself.
7178 for (unsigned I = 0, E = PD.getNumTypeObjects(); I != E; ++I) {
7179 if (PD.getTypeObject(i: I).getAttrs().hasAttribute(K: Kind))
7180 return true;
7181 }
7182
7183 // Finally, check attributes on the decl itself.
7184 return PD.getAttributes().hasAttribute(K: Kind) ||
7185 PD.getDeclarationAttributes().hasAttribute(K: Kind);
7186}
7187
7188bool Sema::adjustContextForLocalExternDecl(DeclContext *&DC) {
7189 if (!DC->isFunctionOrMethod())
7190 return false;
7191
7192 // If this is a local extern function or variable declared within a function
7193 // template, don't add it into the enclosing namespace scope until it is
7194 // instantiated; it might have a dependent type right now.
7195 if (DC->isDependentContext())
7196 return true;
7197
7198 // C++11 [basic.link]p7:
7199 // When a block scope declaration of an entity with linkage is not found to
7200 // refer to some other declaration, then that entity is a member of the
7201 // innermost enclosing namespace.
7202 //
7203 // Per C++11 [namespace.def]p6, the innermost enclosing namespace is a
7204 // semantically-enclosing namespace, not a lexically-enclosing one.
7205 while (!DC->isFileContext() && !isa<LinkageSpecDecl>(Val: DC))
7206 DC = DC->getParent();
7207 return true;
7208}
7209
7210/// Returns true if given declaration has external C language linkage.
7211static bool isDeclExternC(const Decl *D) {
7212 if (const auto *FD = dyn_cast<FunctionDecl>(Val: D))
7213 return FD->isExternC();
7214 if (const auto *VD = dyn_cast<VarDecl>(Val: D))
7215 return VD->isExternC();
7216
7217 llvm_unreachable("Unknown type of decl!");
7218}
7219
7220/// Returns true if there hasn't been any invalid type diagnosed.
7221static bool diagnoseOpenCLTypes(Sema &Se, VarDecl *NewVD) {
7222 DeclContext *DC = NewVD->getDeclContext();
7223 QualType R = NewVD->getType();
7224
7225 // OpenCL v2.0 s6.9.b - Image type can only be used as a function argument.
7226 // OpenCL v2.0 s6.13.16.1 - Pipe type can only be used as a function
7227 // argument.
7228 if (R->isImageType() || R->isPipeType()) {
7229 Se.Diag(Loc: NewVD->getLocation(),
7230 DiagID: diag::err_opencl_type_can_only_be_used_as_function_parameter)
7231 << R;
7232 NewVD->setInvalidDecl();
7233 return false;
7234 }
7235
7236 // OpenCL v1.2 s6.9.r:
7237 // The event type cannot be used to declare a program scope variable.
7238 // OpenCL v2.0 s6.9.q:
7239 // The clk_event_t and reserve_id_t types cannot be declared in program
7240 // scope.
7241 if (NewVD->hasGlobalStorage() && !NewVD->isStaticLocal()) {
7242 if (R->isReserveIDT() || R->isClkEventT() || R->isEventT()) {
7243 Se.Diag(Loc: NewVD->getLocation(),
7244 DiagID: diag::err_invalid_type_for_program_scope_var)
7245 << R;
7246 NewVD->setInvalidDecl();
7247 return false;
7248 }
7249 }
7250
7251 // OpenCL v1.0 s6.8.a.3: Pointers to functions are not allowed.
7252 if (!Se.getOpenCLOptions().isAvailableOption(Ext: "__cl_clang_function_pointers",
7253 LO: Se.getLangOpts())) {
7254 QualType NR = R.getCanonicalType();
7255 while (NR->isPointerType() || NR->isMemberFunctionPointerType() ||
7256 NR->isReferenceType()) {
7257 if (NR->isFunctionPointerType() || NR->isMemberFunctionPointerType() ||
7258 NR->isFunctionReferenceType()) {
7259 Se.Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_function_pointer)
7260 << NR->isReferenceType();
7261 NewVD->setInvalidDecl();
7262 return false;
7263 }
7264 NR = NR->getPointeeType();
7265 }
7266 }
7267
7268 if (!Se.getOpenCLOptions().isAvailableOption(Ext: "cl_khr_fp16",
7269 LO: Se.getLangOpts())) {
7270 // OpenCL v1.2 s6.1.1.1: reject declaring variables of the half and
7271 // half array type (unless the cl_khr_fp16 extension is enabled).
7272 if (Se.Context.getBaseElementType(QT: R)->isHalfType()) {
7273 Se.Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_half_declaration) << R;
7274 NewVD->setInvalidDecl();
7275 return false;
7276 }
7277 }
7278
7279 // OpenCL v1.2 s6.9.r:
7280 // The event type cannot be used with the __local, __constant and __global
7281 // address space qualifiers.
7282 if (R->isEventT()) {
7283 if (R.getAddressSpace() != LangAS::opencl_private) {
7284 Se.Diag(Loc: NewVD->getBeginLoc(), DiagID: diag::err_event_t_addr_space_qual);
7285 NewVD->setInvalidDecl();
7286 return false;
7287 }
7288 }
7289
7290 if (R->isSamplerT()) {
7291 // OpenCL v1.2 s6.9.b p4:
7292 // The sampler type cannot be used with the __local and __global address
7293 // space qualifiers.
7294 if (R.getAddressSpace() == LangAS::opencl_local ||
7295 R.getAddressSpace() == LangAS::opencl_global) {
7296 Se.Diag(Loc: NewVD->getLocation(), DiagID: diag::err_wrong_sampler_addressspace);
7297 NewVD->setInvalidDecl();
7298 }
7299
7300 // OpenCL v1.2 s6.12.14.1:
7301 // A global sampler must be declared with either the constant address
7302 // space qualifier or with the const qualifier.
7303 if (DC->isTranslationUnit() &&
7304 !(R.getAddressSpace() == LangAS::opencl_constant ||
7305 R.isConstQualified())) {
7306 Se.Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_nonconst_global_sampler);
7307 NewVD->setInvalidDecl();
7308 }
7309 if (NewVD->isInvalidDecl())
7310 return false;
7311 }
7312
7313 return true;
7314}
7315
7316template <typename AttrTy>
7317static void copyAttrFromTypedefToDecl(Sema &S, Decl *D, const TypedefType *TT) {
7318 const TypedefNameDecl *TND = TT->getDecl();
7319 if (const auto *Attribute = TND->getAttr<AttrTy>()) {
7320 AttrTy *Clone = Attribute->clone(S.Context);
7321 Clone->setInherited(true);
7322 D->addAttr(A: Clone);
7323 }
7324}
7325
7326// This function emits warning and a corresponding note based on the
7327// ReadOnlyPlacementAttr attribute. The warning checks that all global variable
7328// declarations of an annotated type must be const qualified.
7329void emitReadOnlyPlacementAttrWarning(Sema &S, const VarDecl *VD) {
7330 QualType VarType = VD->getType().getCanonicalType();
7331
7332 // Ignore local declarations (for now) and those with const qualification.
7333 // TODO: Local variables should not be allowed if their type declaration has
7334 // ReadOnlyPlacementAttr attribute. To be handled in follow-up patch.
7335 if (!VD || VD->hasLocalStorage() || VD->getType().isConstQualified())
7336 return;
7337
7338 if (VarType->isArrayType()) {
7339 // Retrieve element type for array declarations.
7340 VarType = S.getASTContext().getBaseElementType(QT: VarType);
7341 }
7342
7343 const RecordDecl *RD = VarType->getAsRecordDecl();
7344
7345 // Check if the record declaration is present and if it has any attributes.
7346 if (RD == nullptr)
7347 return;
7348
7349 if (const auto *ConstDecl = RD->getAttr<ReadOnlyPlacementAttr>()) {
7350 S.Diag(Loc: VD->getLocation(), DiagID: diag::warn_var_decl_not_read_only) << RD;
7351 S.Diag(Loc: ConstDecl->getLocation(), DiagID: diag::note_enforce_read_only_placement);
7352 return;
7353 }
7354}
7355
7356NamedDecl *Sema::ActOnVariableDeclarator(
7357 Scope *S, Declarator &D, DeclContext *DC, TypeSourceInfo *TInfo,
7358 LookupResult &Previous, MultiTemplateParamsArg TemplateParamLists,
7359 bool &AddToScope, ArrayRef<BindingDecl *> Bindings) {
7360 QualType R = TInfo->getType();
7361 DeclarationName Name = GetNameForDeclarator(D).getName();
7362
7363 IdentifierInfo *II = Name.getAsIdentifierInfo();
7364 bool IsPlaceholderVariable = false;
7365
7366 if (D.isDecompositionDeclarator()) {
7367 // Take the name of the first declarator as our name for diagnostic
7368 // purposes.
7369 auto &Decomp = D.getDecompositionDeclarator();
7370 if (!Decomp.bindings().empty()) {
7371 II = Decomp.bindings()[0].Name;
7372 Name = II;
7373 }
7374 } else if (!II) {
7375 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_bad_variable_name) << Name;
7376 return nullptr;
7377 }
7378
7379
7380 DeclSpec::SCS SCSpec = D.getDeclSpec().getStorageClassSpec();
7381 StorageClass SC = StorageClassSpecToVarDeclStorageClass(DS: D.getDeclSpec());
7382
7383 if (LangOpts.CPlusPlus && (DC->isClosure() || DC->isFunctionOrMethod()) &&
7384 SC != SC_Static && SC != SC_Extern && II && II->isPlaceholder()) {
7385 IsPlaceholderVariable = true;
7386 if (!Previous.empty()) {
7387 NamedDecl *PrevDecl = *Previous.begin();
7388 bool SameDC = PrevDecl->getDeclContext()->getRedeclContext()->Equals(
7389 DC: DC->getRedeclContext());
7390 if (SameDC && isDeclInScope(D: PrevDecl, Ctx: CurContext, S, AllowInlineNamespace: false))
7391 DiagPlaceholderVariableDefinition(Loc: D.getIdentifierLoc());
7392 }
7393 }
7394
7395 // dllimport globals without explicit storage class are treated as extern. We
7396 // have to change the storage class this early to get the right DeclContext.
7397 if (SC == SC_None && !DC->isRecord() &&
7398 hasParsedAttr(S, PD: D, Kind: ParsedAttr::AT_DLLImport) &&
7399 !hasParsedAttr(S, PD: D, Kind: ParsedAttr::AT_DLLExport))
7400 SC = SC_Extern;
7401
7402 DeclContext *OriginalDC = DC;
7403 bool IsLocalExternDecl = SC == SC_Extern &&
7404 adjustContextForLocalExternDecl(DC);
7405
7406 if (SCSpec == DeclSpec::SCS_mutable) {
7407 // mutable can only appear on non-static class members, so it's always
7408 // an error here
7409 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_mutable_nonmember);
7410 D.setInvalidType();
7411 SC = SC_None;
7412 }
7413
7414 if (getLangOpts().CPlusPlus11 && SCSpec == DeclSpec::SCS_register &&
7415 !D.getAsmLabel() && !getSourceManager().isInSystemMacro(
7416 loc: D.getDeclSpec().getStorageClassSpecLoc())) {
7417 // In C++11, the 'register' storage class specifier is deprecated.
7418 // Suppress the warning in system macros, it's used in macros in some
7419 // popular C system headers, such as in glibc's htonl() macro.
7420 Diag(Loc: D.getDeclSpec().getStorageClassSpecLoc(),
7421 DiagID: getLangOpts().CPlusPlus17 ? diag::ext_register_storage_class
7422 : diag::warn_deprecated_register)
7423 << FixItHint::CreateRemoval(RemoveRange: D.getDeclSpec().getStorageClassSpecLoc());
7424 }
7425
7426 DiagnoseFunctionSpecifiers(DS: D.getDeclSpec());
7427
7428 if (!DC->isRecord() && S->getFnParent() == nullptr) {
7429 // C99 6.9p2: The storage-class specifiers auto and register shall not
7430 // appear in the declaration specifiers in an external declaration.
7431 // Global Register+Asm is a GNU extension we support.
7432 if (SC == SC_Auto || (SC == SC_Register && !D.getAsmLabel())) {
7433 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_typecheck_sclass_fscope);
7434 D.setInvalidType();
7435 }
7436 }
7437
7438 // If this variable has a VLA type and an initializer, try to
7439 // fold to a constant-sized type. This is otherwise invalid.
7440 if (D.hasInitializer() && R->isVariableArrayType())
7441 tryToFixVariablyModifiedVarType(TInfo, T&: R, Loc: D.getIdentifierLoc(),
7442 /*DiagID=*/FailedFoldDiagID: 0);
7443
7444 if (AutoTypeLoc TL = TInfo->getTypeLoc().getContainedAutoTypeLoc()) {
7445 const AutoType *AT = TL.getTypePtr();
7446 CheckConstrainedAuto(AutoT: AT, Loc: TL.getConceptNameLoc());
7447 }
7448
7449 bool IsMemberSpecialization = false;
7450 bool IsVariableTemplateSpecialization = false;
7451 bool IsPartialSpecialization = false;
7452 bool IsVariableTemplate = false;
7453 VarDecl *NewVD = nullptr;
7454 VarTemplateDecl *NewTemplate = nullptr;
7455 TemplateParameterList *TemplateParams = nullptr;
7456 if (!getLangOpts().CPlusPlus) {
7457 NewVD = VarDecl::Create(C&: Context, DC, StartLoc: D.getBeginLoc(), IdLoc: D.getIdentifierLoc(),
7458 Id: II, T: R, TInfo, S: SC);
7459
7460 if (R->getContainedDeducedType())
7461 ParsingInitForAutoVars.insert(Ptr: NewVD);
7462
7463 if (D.isInvalidType())
7464 NewVD->setInvalidDecl();
7465
7466 if (NewVD->getType().hasNonTrivialToPrimitiveDestructCUnion() &&
7467 NewVD->hasLocalStorage())
7468 checkNonTrivialCUnion(QT: NewVD->getType(), Loc: NewVD->getLocation(),
7469 UseContext: NTCUC_AutoVar, NonTrivialKind: NTCUK_Destruct);
7470 } else {
7471 bool Invalid = false;
7472 // Match up the template parameter lists with the scope specifier, then
7473 // determine whether we have a template or a template specialization.
7474 TemplateParams = MatchTemplateParametersToScopeSpecifier(
7475 DeclStartLoc: D.getDeclSpec().getBeginLoc(), DeclLoc: D.getIdentifierLoc(),
7476 SS: D.getCXXScopeSpec(),
7477 TemplateId: D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
7478 ? D.getName().TemplateId
7479 : nullptr,
7480 ParamLists: TemplateParamLists,
7481 /*never a friend*/ IsFriend: false, IsMemberSpecialization, Invalid);
7482
7483 if (TemplateParams) {
7484 if (!TemplateParams->size() &&
7485 D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) {
7486 // There is an extraneous 'template<>' for this variable. Complain
7487 // about it, but allow the declaration of the variable.
7488 Diag(Loc: TemplateParams->getTemplateLoc(),
7489 DiagID: diag::err_template_variable_noparams)
7490 << II
7491 << SourceRange(TemplateParams->getTemplateLoc(),
7492 TemplateParams->getRAngleLoc());
7493 TemplateParams = nullptr;
7494 } else {
7495 // Check that we can declare a template here.
7496 if (CheckTemplateDeclScope(S, TemplateParams))
7497 return nullptr;
7498
7499 if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) {
7500 // This is an explicit specialization or a partial specialization.
7501 IsVariableTemplateSpecialization = true;
7502 IsPartialSpecialization = TemplateParams->size() > 0;
7503 } else { // if (TemplateParams->size() > 0)
7504 // This is a template declaration.
7505 IsVariableTemplate = true;
7506
7507 // Only C++1y supports variable templates (N3651).
7508 Diag(Loc: D.getIdentifierLoc(),
7509 DiagID: getLangOpts().CPlusPlus14
7510 ? diag::warn_cxx11_compat_variable_template
7511 : diag::ext_variable_template);
7512 }
7513 }
7514 } else {
7515 // Check that we can declare a member specialization here.
7516 if (!TemplateParamLists.empty() && IsMemberSpecialization &&
7517 CheckTemplateDeclScope(S, TemplateParams: TemplateParamLists.back()))
7518 return nullptr;
7519 assert((Invalid ||
7520 D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) &&
7521 "should have a 'template<>' for this decl");
7522 }
7523
7524 bool IsExplicitSpecialization =
7525 IsVariableTemplateSpecialization && !IsPartialSpecialization;
7526
7527 // C++ [temp.expl.spec]p2:
7528 // The declaration in an explicit-specialization shall not be an
7529 // export-declaration. An explicit specialization shall not use a
7530 // storage-class-specifier other than thread_local.
7531 //
7532 // We use the storage-class-specifier from DeclSpec because we may have
7533 // added implicit 'extern' for declarations with __declspec(dllimport)!
7534 if (SCSpec != DeclSpec::SCS_unspecified &&
7535 (IsExplicitSpecialization || IsMemberSpecialization)) {
7536 Diag(Loc: D.getDeclSpec().getStorageClassSpecLoc(),
7537 DiagID: diag::ext_explicit_specialization_storage_class)
7538 << FixItHint::CreateRemoval(RemoveRange: D.getDeclSpec().getStorageClassSpecLoc());
7539 }
7540
7541 if (CurContext->isRecord()) {
7542 if (SC == SC_Static) {
7543 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Val: DC)) {
7544 // Walk up the enclosing DeclContexts to check for any that are
7545 // incompatible with static data members.
7546 const DeclContext *FunctionOrMethod = nullptr;
7547 const CXXRecordDecl *AnonStruct = nullptr;
7548 for (DeclContext *Ctxt = DC; Ctxt; Ctxt = Ctxt->getParent()) {
7549 if (Ctxt->isFunctionOrMethod()) {
7550 FunctionOrMethod = Ctxt;
7551 break;
7552 }
7553 const CXXRecordDecl *ParentDecl = dyn_cast<CXXRecordDecl>(Val: Ctxt);
7554 if (ParentDecl && !ParentDecl->getDeclName()) {
7555 AnonStruct = ParentDecl;
7556 break;
7557 }
7558 }
7559 if (FunctionOrMethod) {
7560 // C++ [class.static.data]p5: A local class shall not have static
7561 // data members.
7562 Diag(Loc: D.getIdentifierLoc(),
7563 DiagID: diag::err_static_data_member_not_allowed_in_local_class)
7564 << Name << RD->getDeclName()
7565 << llvm::to_underlying(E: RD->getTagKind());
7566 } else if (AnonStruct) {
7567 // C++ [class.static.data]p4: Unnamed classes and classes contained
7568 // directly or indirectly within unnamed classes shall not contain
7569 // static data members.
7570 Diag(Loc: D.getIdentifierLoc(),
7571 DiagID: diag::err_static_data_member_not_allowed_in_anon_struct)
7572 << Name << llvm::to_underlying(E: AnonStruct->getTagKind());
7573 Invalid = true;
7574 } else if (RD->isUnion()) {
7575 // C++98 [class.union]p1: If a union contains a static data member,
7576 // the program is ill-formed. C++11 drops this restriction.
7577 Diag(Loc: D.getIdentifierLoc(),
7578 DiagID: getLangOpts().CPlusPlus11
7579 ? diag::warn_cxx98_compat_static_data_member_in_union
7580 : diag::ext_static_data_member_in_union)
7581 << Name;
7582 }
7583 }
7584 } else if (IsVariableTemplate || IsPartialSpecialization) {
7585 // There is no such thing as a member field template.
7586 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_template_member)
7587 << II << TemplateParams->getSourceRange();
7588 // Recover by pretending this is a static data member template.
7589 SC = SC_Static;
7590 }
7591 } else if (DC->isRecord()) {
7592 // This is an out-of-line definition of a static data member.
7593 switch (SC) {
7594 case SC_None:
7595 break;
7596 case SC_Static:
7597 Diag(Loc: D.getDeclSpec().getStorageClassSpecLoc(),
7598 DiagID: diag::err_static_out_of_line)
7599 << FixItHint::CreateRemoval(
7600 RemoveRange: D.getDeclSpec().getStorageClassSpecLoc());
7601 break;
7602 case SC_Auto:
7603 case SC_Register:
7604 case SC_Extern:
7605 // [dcl.stc] p2: The auto or register specifiers shall be applied only
7606 // to names of variables declared in a block or to function parameters.
7607 // [dcl.stc] p6: The extern specifier cannot be used in the declaration
7608 // of class members
7609
7610 Diag(Loc: D.getDeclSpec().getStorageClassSpecLoc(),
7611 DiagID: diag::err_storage_class_for_static_member)
7612 << FixItHint::CreateRemoval(
7613 RemoveRange: D.getDeclSpec().getStorageClassSpecLoc());
7614 break;
7615 case SC_PrivateExtern:
7616 llvm_unreachable("C storage class in c++!");
7617 }
7618 }
7619
7620 if (IsVariableTemplateSpecialization) {
7621 SourceLocation TemplateKWLoc =
7622 TemplateParamLists.size() > 0
7623 ? TemplateParamLists[0]->getTemplateLoc()
7624 : SourceLocation();
7625 DeclResult Res = ActOnVarTemplateSpecialization(
7626 S, D, DI: TInfo, Previous, TemplateKWLoc, TemplateParams, SC,
7627 IsPartialSpecialization);
7628 if (Res.isInvalid())
7629 return nullptr;
7630 NewVD = cast<VarDecl>(Val: Res.get());
7631 AddToScope = false;
7632 } else if (D.isDecompositionDeclarator()) {
7633 NewVD = DecompositionDecl::Create(C&: Context, DC, StartLoc: D.getBeginLoc(),
7634 LSquareLoc: D.getIdentifierLoc(), T: R, TInfo, S: SC,
7635 Bindings);
7636 } else
7637 NewVD = VarDecl::Create(C&: Context, DC, StartLoc: D.getBeginLoc(),
7638 IdLoc: D.getIdentifierLoc(), Id: II, T: R, TInfo, S: SC);
7639
7640 // If this is supposed to be a variable template, create it as such.
7641 if (IsVariableTemplate) {
7642 NewTemplate =
7643 VarTemplateDecl::Create(C&: Context, DC, L: D.getIdentifierLoc(), Name,
7644 Params: TemplateParams, Decl: NewVD);
7645 NewVD->setDescribedVarTemplate(NewTemplate);
7646 }
7647
7648 // If this decl has an auto type in need of deduction, make a note of the
7649 // Decl so we can diagnose uses of it in its own initializer.
7650 if (R->getContainedDeducedType())
7651 ParsingInitForAutoVars.insert(Ptr: NewVD);
7652
7653 if (D.isInvalidType() || Invalid) {
7654 NewVD->setInvalidDecl();
7655 if (NewTemplate)
7656 NewTemplate->setInvalidDecl();
7657 }
7658
7659 SetNestedNameSpecifier(S&: *this, DD: NewVD, D);
7660
7661 // If we have any template parameter lists that don't directly belong to
7662 // the variable (matching the scope specifier), store them.
7663 // An explicit variable template specialization does not own any template
7664 // parameter lists.
7665 unsigned VDTemplateParamLists =
7666 (TemplateParams && !IsExplicitSpecialization) ? 1 : 0;
7667 if (TemplateParamLists.size() > VDTemplateParamLists)
7668 NewVD->setTemplateParameterListsInfo(
7669 Context, TPLists: TemplateParamLists.drop_back(N: VDTemplateParamLists));
7670 }
7671
7672 if (D.getDeclSpec().isInlineSpecified()) {
7673 if (!getLangOpts().CPlusPlus) {
7674 Diag(Loc: D.getDeclSpec().getInlineSpecLoc(), DiagID: diag::err_inline_non_function)
7675 << 0;
7676 } else if (CurContext->isFunctionOrMethod()) {
7677 // 'inline' is not allowed on block scope variable declaration.
7678 Diag(Loc: D.getDeclSpec().getInlineSpecLoc(),
7679 DiagID: diag::err_inline_declaration_block_scope) << Name
7680 << FixItHint::CreateRemoval(RemoveRange: D.getDeclSpec().getInlineSpecLoc());
7681 } else {
7682 Diag(Loc: D.getDeclSpec().getInlineSpecLoc(),
7683 DiagID: getLangOpts().CPlusPlus17 ? diag::warn_cxx14_compat_inline_variable
7684 : diag::ext_inline_variable);
7685 NewVD->setInlineSpecified();
7686 }
7687 }
7688
7689 // Set the lexical context. If the declarator has a C++ scope specifier, the
7690 // lexical context will be different from the semantic context.
7691 NewVD->setLexicalDeclContext(CurContext);
7692 if (NewTemplate)
7693 NewTemplate->setLexicalDeclContext(CurContext);
7694
7695 if (IsLocalExternDecl) {
7696 if (D.isDecompositionDeclarator())
7697 for (auto *B : Bindings)
7698 B->setLocalExternDecl();
7699 else
7700 NewVD->setLocalExternDecl();
7701 }
7702
7703 bool EmitTLSUnsupportedError = false;
7704 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec()) {
7705 // C++11 [dcl.stc]p4:
7706 // When thread_local is applied to a variable of block scope the
7707 // storage-class-specifier static is implied if it does not appear
7708 // explicitly.
7709 // Core issue: 'static' is not implied if the variable is declared
7710 // 'extern'.
7711 if (NewVD->hasLocalStorage() &&
7712 (SCSpec != DeclSpec::SCS_unspecified ||
7713 TSCS != DeclSpec::TSCS_thread_local ||
7714 !DC->isFunctionOrMethod()))
7715 Diag(Loc: D.getDeclSpec().getThreadStorageClassSpecLoc(),
7716 DiagID: diag::err_thread_non_global)
7717 << DeclSpec::getSpecifierName(S: TSCS);
7718 else if (!Context.getTargetInfo().isTLSSupported()) {
7719 if (getLangOpts().CUDA || getLangOpts().OpenMPIsTargetDevice ||
7720 getLangOpts().SYCLIsDevice) {
7721 // Postpone error emission until we've collected attributes required to
7722 // figure out whether it's a host or device variable and whether the
7723 // error should be ignored.
7724 EmitTLSUnsupportedError = true;
7725 // We still need to mark the variable as TLS so it shows up in AST with
7726 // proper storage class for other tools to use even if we're not going
7727 // to emit any code for it.
7728 NewVD->setTSCSpec(TSCS);
7729 } else
7730 Diag(Loc: D.getDeclSpec().getThreadStorageClassSpecLoc(),
7731 DiagID: diag::err_thread_unsupported);
7732 } else
7733 NewVD->setTSCSpec(TSCS);
7734 }
7735
7736 switch (D.getDeclSpec().getConstexprSpecifier()) {
7737 case ConstexprSpecKind::Unspecified:
7738 break;
7739
7740 case ConstexprSpecKind::Consteval:
7741 Diag(Loc: D.getDeclSpec().getConstexprSpecLoc(),
7742 DiagID: diag::err_constexpr_wrong_decl_kind)
7743 << static_cast<int>(D.getDeclSpec().getConstexprSpecifier());
7744 [[fallthrough]];
7745
7746 case ConstexprSpecKind::Constexpr:
7747 NewVD->setConstexpr(true);
7748 // C++1z [dcl.spec.constexpr]p1:
7749 // A static data member declared with the constexpr specifier is
7750 // implicitly an inline variable.
7751 if (NewVD->isStaticDataMember() &&
7752 (getLangOpts().CPlusPlus17 ||
7753 Context.getTargetInfo().getCXXABI().isMicrosoft()))
7754 NewVD->setImplicitlyInline();
7755 break;
7756
7757 case ConstexprSpecKind::Constinit:
7758 if (!NewVD->hasGlobalStorage())
7759 Diag(Loc: D.getDeclSpec().getConstexprSpecLoc(),
7760 DiagID: diag::err_constinit_local_variable);
7761 else
7762 NewVD->addAttr(
7763 A: ConstInitAttr::Create(Ctx&: Context, Range: D.getDeclSpec().getConstexprSpecLoc(),
7764 S: ConstInitAttr::Keyword_constinit));
7765 break;
7766 }
7767
7768 // C99 6.7.4p3
7769 // An inline definition of a function with external linkage shall
7770 // not contain a definition of a modifiable object with static or
7771 // thread storage duration...
7772 // We only apply this when the function is required to be defined
7773 // elsewhere, i.e. when the function is not 'extern inline'. Note
7774 // that a local variable with thread storage duration still has to
7775 // be marked 'static'. Also note that it's possible to get these
7776 // semantics in C++ using __attribute__((gnu_inline)).
7777 if (SC == SC_Static && S->getFnParent() != nullptr &&
7778 !NewVD->getType().isConstQualified()) {
7779 FunctionDecl *CurFD = getCurFunctionDecl();
7780 if (CurFD && isFunctionDefinitionDiscarded(S&: *this, FD: CurFD)) {
7781 Diag(Loc: D.getDeclSpec().getStorageClassSpecLoc(),
7782 DiagID: diag::warn_static_local_in_extern_inline);
7783 MaybeSuggestAddingStaticToDecl(D: CurFD);
7784 }
7785 }
7786
7787 if (D.getDeclSpec().isModulePrivateSpecified()) {
7788 if (IsVariableTemplateSpecialization)
7789 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_module_private_specialization)
7790 << (IsPartialSpecialization ? 1 : 0)
7791 << FixItHint::CreateRemoval(
7792 RemoveRange: D.getDeclSpec().getModulePrivateSpecLoc());
7793 else if (IsMemberSpecialization)
7794 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_module_private_specialization)
7795 << 2
7796 << FixItHint::CreateRemoval(RemoveRange: D.getDeclSpec().getModulePrivateSpecLoc());
7797 else if (NewVD->hasLocalStorage())
7798 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_module_private_local)
7799 << 0 << NewVD
7800 << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
7801 << FixItHint::CreateRemoval(
7802 RemoveRange: D.getDeclSpec().getModulePrivateSpecLoc());
7803 else {
7804 NewVD->setModulePrivate();
7805 if (NewTemplate)
7806 NewTemplate->setModulePrivate();
7807 for (auto *B : Bindings)
7808 B->setModulePrivate();
7809 }
7810 }
7811
7812 if (getLangOpts().OpenCL) {
7813 deduceOpenCLAddressSpace(Decl: NewVD);
7814
7815 DeclSpec::TSCS TSC = D.getDeclSpec().getThreadStorageClassSpec();
7816 if (TSC != TSCS_unspecified) {
7817 Diag(Loc: D.getDeclSpec().getThreadStorageClassSpecLoc(),
7818 DiagID: diag::err_opencl_unknown_type_specifier)
7819 << getLangOpts().getOpenCLVersionString()
7820 << DeclSpec::getSpecifierName(S: TSC) << 1;
7821 NewVD->setInvalidDecl();
7822 }
7823 }
7824
7825 // WebAssembly tables are always in address space 1 (wasm_var). Don't apply
7826 // address space if the table has local storage (semantic checks elsewhere
7827 // will produce an error anyway).
7828 if (const auto *ATy = dyn_cast<ArrayType>(Val: NewVD->getType())) {
7829 if (ATy && ATy->getElementType().isWebAssemblyReferenceType() &&
7830 !NewVD->hasLocalStorage()) {
7831 QualType Type = Context.getAddrSpaceQualType(
7832 T: NewVD->getType(), AddressSpace: Context.getLangASForBuiltinAddressSpace(AS: 1));
7833 NewVD->setType(Type);
7834 }
7835 }
7836
7837 // Handle attributes prior to checking for duplicates in MergeVarDecl
7838 ProcessDeclAttributes(S, D: NewVD, PD: D);
7839
7840 // FIXME: This is probably the wrong location to be doing this and we should
7841 // probably be doing this for more attributes (especially for function
7842 // pointer attributes such as format, warn_unused_result, etc.). Ideally
7843 // the code to copy attributes would be generated by TableGen.
7844 if (R->isFunctionPointerType())
7845 if (const auto *TT = R->getAs<TypedefType>())
7846 copyAttrFromTypedefToDecl<AllocSizeAttr>(S&: *this, D: NewVD, TT);
7847
7848 if (getLangOpts().CUDA || getLangOpts().OpenMPIsTargetDevice ||
7849 getLangOpts().SYCLIsDevice) {
7850 if (EmitTLSUnsupportedError &&
7851 ((getLangOpts().CUDA && DeclAttrsMatchCUDAMode(LangOpts: getLangOpts(), D: NewVD)) ||
7852 (getLangOpts().OpenMPIsTargetDevice &&
7853 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD: NewVD))))
7854 Diag(Loc: D.getDeclSpec().getThreadStorageClassSpecLoc(),
7855 DiagID: diag::err_thread_unsupported);
7856
7857 if (EmitTLSUnsupportedError &&
7858 (LangOpts.SYCLIsDevice ||
7859 (LangOpts.OpenMP && LangOpts.OpenMPIsTargetDevice)))
7860 targetDiag(Loc: D.getIdentifierLoc(), DiagID: diag::err_thread_unsupported);
7861 // CUDA B.2.5: "__shared__ and __constant__ variables have implied static
7862 // storage [duration]."
7863 if (SC == SC_None && S->getFnParent() != nullptr &&
7864 (NewVD->hasAttr<CUDASharedAttr>() ||
7865 NewVD->hasAttr<CUDAConstantAttr>())) {
7866 NewVD->setStorageClass(SC_Static);
7867 }
7868 }
7869
7870 // Ensure that dllimport globals without explicit storage class are treated as
7871 // extern. The storage class is set above using parsed attributes. Now we can
7872 // check the VarDecl itself.
7873 assert(!NewVD->hasAttr<DLLImportAttr>() ||
7874 NewVD->getAttr<DLLImportAttr>()->isInherited() ||
7875 NewVD->isStaticDataMember() || NewVD->getStorageClass() != SC_None);
7876
7877 // In auto-retain/release, infer strong retension for variables of
7878 // retainable type.
7879 if (getLangOpts().ObjCAutoRefCount && ObjC().inferObjCARCLifetime(decl: NewVD))
7880 NewVD->setInvalidDecl();
7881
7882 // Handle GNU asm-label extension (encoded as an attribute).
7883 if (Expr *E = (Expr*)D.getAsmLabel()) {
7884 // The parser guarantees this is a string.
7885 StringLiteral *SE = cast<StringLiteral>(Val: E);
7886 StringRef Label = SE->getString();
7887 if (S->getFnParent() != nullptr) {
7888 switch (SC) {
7889 case SC_None:
7890 case SC_Auto:
7891 Diag(Loc: E->getExprLoc(), DiagID: diag::warn_asm_label_on_auto_decl) << Label;
7892 break;
7893 case SC_Register:
7894 // Local Named register
7895 if (!Context.getTargetInfo().isValidGCCRegisterName(Name: Label) &&
7896 DeclAttrsMatchCUDAMode(LangOpts: getLangOpts(), D: getCurFunctionDecl()))
7897 Diag(Loc: E->getExprLoc(), DiagID: diag::err_asm_unknown_register_name) << Label;
7898 break;
7899 case SC_Static:
7900 case SC_Extern:
7901 case SC_PrivateExtern:
7902 break;
7903 }
7904 } else if (SC == SC_Register) {
7905 // Global Named register
7906 if (DeclAttrsMatchCUDAMode(LangOpts: getLangOpts(), D: NewVD)) {
7907 const auto &TI = Context.getTargetInfo();
7908 bool HasSizeMismatch;
7909
7910 if (!TI.isValidGCCRegisterName(Name: Label))
7911 Diag(Loc: E->getExprLoc(), DiagID: diag::err_asm_unknown_register_name) << Label;
7912 else if (!TI.validateGlobalRegisterVariable(RegName: Label,
7913 RegSize: Context.getTypeSize(T: R),
7914 HasSizeMismatch))
7915 Diag(Loc: E->getExprLoc(), DiagID: diag::err_asm_invalid_global_var_reg) << Label;
7916 else if (HasSizeMismatch)
7917 Diag(Loc: E->getExprLoc(), DiagID: diag::err_asm_register_size_mismatch) << Label;
7918 }
7919
7920 if (!R->isIntegralType(Ctx: Context) && !R->isPointerType()) {
7921 Diag(Loc: D.getBeginLoc(), DiagID: diag::err_asm_bad_register_type);
7922 NewVD->setInvalidDecl(true);
7923 }
7924 }
7925
7926 NewVD->addAttr(A: AsmLabelAttr::Create(Ctx&: Context, Label,
7927 /*IsLiteralLabel=*/true,
7928 Range: SE->getStrTokenLoc(TokNum: 0)));
7929 } else if (!ExtnameUndeclaredIdentifiers.empty()) {
7930 llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
7931 ExtnameUndeclaredIdentifiers.find(Val: NewVD->getIdentifier());
7932 if (I != ExtnameUndeclaredIdentifiers.end()) {
7933 if (isDeclExternC(D: NewVD)) {
7934 NewVD->addAttr(A: I->second);
7935 ExtnameUndeclaredIdentifiers.erase(I);
7936 } else
7937 Diag(Loc: NewVD->getLocation(), DiagID: diag::warn_redefine_extname_not_applied)
7938 << /*Variable*/1 << NewVD;
7939 }
7940 }
7941
7942 // Find the shadowed declaration before filtering for scope.
7943 NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty()
7944 ? getShadowedDeclaration(D: NewVD, R: Previous)
7945 : nullptr;
7946
7947 // Don't consider existing declarations that are in a different
7948 // scope and are out-of-semantic-context declarations (if the new
7949 // declaration has linkage).
7950 FilterLookupForScope(R&: Previous, Ctx: OriginalDC, S, ConsiderLinkage: shouldConsiderLinkage(VD: NewVD),
7951 AllowInlineNamespace: D.getCXXScopeSpec().isNotEmpty() ||
7952 IsMemberSpecialization ||
7953 IsVariableTemplateSpecialization);
7954
7955 // Check whether the previous declaration is in the same block scope. This
7956 // affects whether we merge types with it, per C++11 [dcl.array]p3.
7957 if (getLangOpts().CPlusPlus &&
7958 NewVD->isLocalVarDecl() && NewVD->hasExternalStorage())
7959 NewVD->setPreviousDeclInSameBlockScope(
7960 Previous.isSingleResult() && !Previous.isShadowed() &&
7961 isDeclInScope(D: Previous.getFoundDecl(), Ctx: OriginalDC, S, AllowInlineNamespace: false));
7962
7963 if (!getLangOpts().CPlusPlus) {
7964 D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous));
7965 } else {
7966 // If this is an explicit specialization of a static data member, check it.
7967 if (IsMemberSpecialization && !IsVariableTemplateSpecialization &&
7968 !NewVD->isInvalidDecl() && CheckMemberSpecialization(Member: NewVD, Previous))
7969 NewVD->setInvalidDecl();
7970
7971 // Merge the decl with the existing one if appropriate.
7972 if (!Previous.empty()) {
7973 if (Previous.isSingleResult() &&
7974 isa<FieldDecl>(Val: Previous.getFoundDecl()) &&
7975 D.getCXXScopeSpec().isSet()) {
7976 // The user tried to define a non-static data member
7977 // out-of-line (C++ [dcl.meaning]p1).
7978 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_nonstatic_member_out_of_line)
7979 << D.getCXXScopeSpec().getRange();
7980 Previous.clear();
7981 NewVD->setInvalidDecl();
7982 }
7983 } else if (D.getCXXScopeSpec().isSet() &&
7984 !IsVariableTemplateSpecialization) {
7985 // No previous declaration in the qualifying scope.
7986 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_no_member)
7987 << Name << computeDeclContext(SS: D.getCXXScopeSpec(), EnteringContext: true)
7988 << D.getCXXScopeSpec().getRange();
7989 NewVD->setInvalidDecl();
7990 }
7991
7992 if (!IsPlaceholderVariable)
7993 D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous));
7994
7995 // CheckVariableDeclaration will set NewVD as invalid if something is in
7996 // error like WebAssembly tables being declared as arrays with a non-zero
7997 // size, but then parsing continues and emits further errors on that line.
7998 // To avoid that we check here if it happened and return nullptr.
7999 if (NewVD->getType()->isWebAssemblyTableType() && NewVD->isInvalidDecl())
8000 return nullptr;
8001
8002 if (NewTemplate) {
8003 VarTemplateDecl *PrevVarTemplate =
8004 NewVD->getPreviousDecl()
8005 ? NewVD->getPreviousDecl()->getDescribedVarTemplate()
8006 : nullptr;
8007
8008 // Check the template parameter list of this declaration, possibly
8009 // merging in the template parameter list from the previous variable
8010 // template declaration.
8011 if (CheckTemplateParameterList(
8012 NewParams: TemplateParams,
8013 OldParams: PrevVarTemplate ? PrevVarTemplate->getTemplateParameters()
8014 : nullptr,
8015 TPC: (D.getCXXScopeSpec().isSet() && DC && DC->isRecord() &&
8016 DC->isDependentContext())
8017 ? TPC_ClassTemplateMember
8018 : TPC_VarTemplate))
8019 NewVD->setInvalidDecl();
8020
8021 // If we are providing an explicit specialization of a static variable
8022 // template, make a note of that.
8023 if (PrevVarTemplate &&
8024 PrevVarTemplate->getInstantiatedFromMemberTemplate())
8025 PrevVarTemplate->setMemberSpecialization();
8026 }
8027 }
8028
8029 // Diagnose shadowed variables iff this isn't a redeclaration.
8030 if (!IsPlaceholderVariable && ShadowedDecl && !D.isRedeclaration())
8031 CheckShadow(D: NewVD, ShadowedDecl, R: Previous);
8032
8033 ProcessPragmaWeak(S, D: NewVD);
8034
8035 // If this is the first declaration of an extern C variable, update
8036 // the map of such variables.
8037 if (NewVD->isFirstDecl() && !NewVD->isInvalidDecl() &&
8038 isIncompleteDeclExternC(S&: *this, D: NewVD))
8039 RegisterLocallyScopedExternCDecl(ND: NewVD, S);
8040
8041 if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
8042 MangleNumberingContext *MCtx;
8043 Decl *ManglingContextDecl;
8044 std::tie(args&: MCtx, args&: ManglingContextDecl) =
8045 getCurrentMangleNumberContext(DC: NewVD->getDeclContext());
8046 if (MCtx) {
8047 Context.setManglingNumber(
8048 ND: NewVD, Number: MCtx->getManglingNumber(
8049 VD: NewVD, MSLocalManglingNumber: getMSManglingNumber(LO: getLangOpts(), S)));
8050 Context.setStaticLocalNumber(VD: NewVD, Number: MCtx->getStaticLocalNumber(VD: NewVD));
8051 }
8052 }
8053
8054 // Special handling of variable named 'main'.
8055 if (Name.getAsIdentifierInfo() && Name.getAsIdentifierInfo()->isStr(Str: "main") &&
8056 NewVD->getDeclContext()->getRedeclContext()->isTranslationUnit() &&
8057 !getLangOpts().Freestanding && !NewVD->getDescribedVarTemplate()) {
8058
8059 // C++ [basic.start.main]p3
8060 // A program that declares a variable main at global scope is ill-formed.
8061 if (getLangOpts().CPlusPlus)
8062 Diag(Loc: D.getBeginLoc(), DiagID: diag::err_main_global_variable);
8063
8064 // In C, and external-linkage variable named main results in undefined
8065 // behavior.
8066 else if (NewVD->hasExternalFormalLinkage())
8067 Diag(Loc: D.getBeginLoc(), DiagID: diag::warn_main_redefined);
8068 }
8069
8070 if (D.isRedeclaration() && !Previous.empty()) {
8071 NamedDecl *Prev = Previous.getRepresentativeDecl();
8072 checkDLLAttributeRedeclaration(S&: *this, OldDecl: Prev, NewDecl: NewVD, IsSpecialization: IsMemberSpecialization,
8073 IsDefinition: D.isFunctionDefinition());
8074 }
8075
8076 if (NewTemplate) {
8077 if (NewVD->isInvalidDecl())
8078 NewTemplate->setInvalidDecl();
8079 ActOnDocumentableDecl(D: NewTemplate);
8080 return NewTemplate;
8081 }
8082
8083 if (IsMemberSpecialization && !NewVD->isInvalidDecl())
8084 CompleteMemberSpecialization(Member: NewVD, Previous);
8085
8086 emitReadOnlyPlacementAttrWarning(S&: *this, VD: NewVD);
8087
8088 return NewVD;
8089}
8090
8091/// Enum describing the %select options in diag::warn_decl_shadow.
8092enum ShadowedDeclKind {
8093 SDK_Local,
8094 SDK_Global,
8095 SDK_StaticMember,
8096 SDK_Field,
8097 SDK_Typedef,
8098 SDK_Using,
8099 SDK_StructuredBinding
8100};
8101
8102/// Determine what kind of declaration we're shadowing.
8103static ShadowedDeclKind computeShadowedDeclKind(const NamedDecl *ShadowedDecl,
8104 const DeclContext *OldDC) {
8105 if (isa<TypeAliasDecl>(Val: ShadowedDecl))
8106 return SDK_Using;
8107 else if (isa<TypedefDecl>(Val: ShadowedDecl))
8108 return SDK_Typedef;
8109 else if (isa<BindingDecl>(Val: ShadowedDecl))
8110 return SDK_StructuredBinding;
8111 else if (isa<RecordDecl>(Val: OldDC))
8112 return isa<FieldDecl>(Val: ShadowedDecl) ? SDK_Field : SDK_StaticMember;
8113
8114 return OldDC->isFileContext() ? SDK_Global : SDK_Local;
8115}
8116
8117/// Return the location of the capture if the given lambda captures the given
8118/// variable \p VD, or an invalid source location otherwise.
8119static SourceLocation getCaptureLocation(const LambdaScopeInfo *LSI,
8120 const VarDecl *VD) {
8121 for (const Capture &Capture : LSI->Captures) {
8122 if (Capture.isVariableCapture() && Capture.getVariable() == VD)
8123 return Capture.getLocation();
8124 }
8125 return SourceLocation();
8126}
8127
8128static bool shouldWarnIfShadowedDecl(const DiagnosticsEngine &Diags,
8129 const LookupResult &R) {
8130 // Only diagnose if we're shadowing an unambiguous field or variable.
8131 if (R.getResultKind() != LookupResult::Found)
8132 return false;
8133
8134 // Return false if warning is ignored.
8135 return !Diags.isIgnored(DiagID: diag::warn_decl_shadow, Loc: R.getNameLoc());
8136}
8137
8138NamedDecl *Sema::getShadowedDeclaration(const VarDecl *D,
8139 const LookupResult &R) {
8140 if (!shouldWarnIfShadowedDecl(Diags, R))
8141 return nullptr;
8142
8143 // Don't diagnose declarations at file scope.
8144 if (D->hasGlobalStorage() && !D->isStaticLocal())
8145 return nullptr;
8146
8147 NamedDecl *ShadowedDecl = R.getFoundDecl();
8148 return isa<VarDecl, FieldDecl, BindingDecl>(Val: ShadowedDecl) ? ShadowedDecl
8149 : nullptr;
8150}
8151
8152NamedDecl *Sema::getShadowedDeclaration(const TypedefNameDecl *D,
8153 const LookupResult &R) {
8154 // Don't warn if typedef declaration is part of a class
8155 if (D->getDeclContext()->isRecord())
8156 return nullptr;
8157
8158 if (!shouldWarnIfShadowedDecl(Diags, R))
8159 return nullptr;
8160
8161 NamedDecl *ShadowedDecl = R.getFoundDecl();
8162 return isa<TypedefNameDecl>(Val: ShadowedDecl) ? ShadowedDecl : nullptr;
8163}
8164
8165NamedDecl *Sema::getShadowedDeclaration(const BindingDecl *D,
8166 const LookupResult &R) {
8167 if (!shouldWarnIfShadowedDecl(Diags, R))
8168 return nullptr;
8169
8170 NamedDecl *ShadowedDecl = R.getFoundDecl();
8171 return isa<VarDecl, FieldDecl, BindingDecl>(Val: ShadowedDecl) ? ShadowedDecl
8172 : nullptr;
8173}
8174
8175void Sema::CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl,
8176 const LookupResult &R) {
8177 DeclContext *NewDC = D->getDeclContext();
8178
8179 if (FieldDecl *FD = dyn_cast<FieldDecl>(Val: ShadowedDecl)) {
8180 // Fields are not shadowed by variables in C++ static methods.
8181 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Val: NewDC))
8182 if (MD->isStatic())
8183 return;
8184
8185 // Fields shadowed by constructor parameters are a special case. Usually
8186 // the constructor initializes the field with the parameter.
8187 if (isa<CXXConstructorDecl>(Val: NewDC))
8188 if (const auto PVD = dyn_cast<ParmVarDecl>(Val: D)) {
8189 // Remember that this was shadowed so we can either warn about its
8190 // modification or its existence depending on warning settings.
8191 ShadowingDecls.insert(KV: {PVD->getCanonicalDecl(), FD});
8192 return;
8193 }
8194 }
8195
8196 if (VarDecl *shadowedVar = dyn_cast<VarDecl>(Val: ShadowedDecl))
8197 if (shadowedVar->isExternC()) {
8198 // For shadowing external vars, make sure that we point to the global
8199 // declaration, not a locally scoped extern declaration.
8200 for (auto *I : shadowedVar->redecls())
8201 if (I->isFileVarDecl()) {
8202 ShadowedDecl = I;
8203 break;
8204 }
8205 }
8206
8207 DeclContext *OldDC = ShadowedDecl->getDeclContext()->getRedeclContext();
8208
8209 unsigned WarningDiag = diag::warn_decl_shadow;
8210 SourceLocation CaptureLoc;
8211 if (isa<VarDecl>(Val: D) && NewDC && isa<CXXMethodDecl>(Val: NewDC)) {
8212 if (const auto *RD = dyn_cast<CXXRecordDecl>(Val: NewDC->getParent())) {
8213 if (RD->isLambda() && OldDC->Encloses(DC: NewDC->getLexicalParent())) {
8214 if (const auto *VD = dyn_cast<VarDecl>(Val: ShadowedDecl)) {
8215 const auto *LSI = cast<LambdaScopeInfo>(Val: getCurFunction());
8216 if (RD->getLambdaCaptureDefault() == LCD_None) {
8217 // Try to avoid warnings for lambdas with an explicit capture
8218 // list. Warn only when the lambda captures the shadowed decl
8219 // explicitly.
8220 CaptureLoc = getCaptureLocation(LSI, VD);
8221 if (CaptureLoc.isInvalid())
8222 WarningDiag = diag::warn_decl_shadow_uncaptured_local;
8223 } else {
8224 // Remember that this was shadowed so we can avoid the warning if
8225 // the shadowed decl isn't captured and the warning settings allow
8226 // it.
8227 cast<LambdaScopeInfo>(Val: getCurFunction())
8228 ->ShadowingDecls.push_back(Elt: {.VD: D, .ShadowedDecl: VD});
8229 return;
8230 }
8231 }
8232 if (isa<FieldDecl>(Val: ShadowedDecl)) {
8233 // If lambda can capture this, then emit default shadowing warning,
8234 // Otherwise it is not really a shadowing case since field is not
8235 // available in lambda's body.
8236 // At this point we don't know that lambda can capture this, so
8237 // remember that this was shadowed and delay until we know.
8238 cast<LambdaScopeInfo>(Val: getCurFunction())
8239 ->ShadowingDecls.push_back(Elt: {.VD: D, .ShadowedDecl: ShadowedDecl});
8240 return;
8241 }
8242 }
8243 if (const auto *VD = dyn_cast<VarDecl>(Val: ShadowedDecl);
8244 VD && VD->hasLocalStorage()) {
8245 // A variable can't shadow a local variable in an enclosing scope, if
8246 // they are separated by a non-capturing declaration context.
8247 for (DeclContext *ParentDC = NewDC;
8248 ParentDC && !ParentDC->Equals(DC: OldDC);
8249 ParentDC = getLambdaAwareParentOfDeclContext(DC: ParentDC)) {
8250 // Only block literals, captured statements, and lambda expressions
8251 // can capture; other scopes don't.
8252 if (!isa<BlockDecl>(Val: ParentDC) && !isa<CapturedDecl>(Val: ParentDC) &&
8253 !isLambdaCallOperator(DC: ParentDC)) {
8254 return;
8255 }
8256 }
8257 }
8258 }
8259 }
8260
8261 // Never warn about shadowing a placeholder variable.
8262 if (ShadowedDecl->isPlaceholderVar(LangOpts: getLangOpts()))
8263 return;
8264
8265 // Only warn about certain kinds of shadowing for class members.
8266 if (NewDC && NewDC->isRecord()) {
8267 // In particular, don't warn about shadowing non-class members.
8268 if (!OldDC->isRecord())
8269 return;
8270
8271 // TODO: should we warn about static data members shadowing
8272 // static data members from base classes?
8273
8274 // TODO: don't diagnose for inaccessible shadowed members.
8275 // This is hard to do perfectly because we might friend the
8276 // shadowing context, but that's just a false negative.
8277 }
8278
8279
8280 DeclarationName Name = R.getLookupName();
8281
8282 // Emit warning and note.
8283 ShadowedDeclKind Kind = computeShadowedDeclKind(ShadowedDecl, OldDC);
8284 Diag(Loc: R.getNameLoc(), DiagID: WarningDiag) << Name << Kind << OldDC;
8285 if (!CaptureLoc.isInvalid())
8286 Diag(Loc: CaptureLoc, DiagID: diag::note_var_explicitly_captured_here)
8287 << Name << /*explicitly*/ 1;
8288 Diag(Loc: ShadowedDecl->getLocation(), DiagID: diag::note_previous_declaration);
8289}
8290
8291void Sema::DiagnoseShadowingLambdaDecls(const LambdaScopeInfo *LSI) {
8292 for (const auto &Shadow : LSI->ShadowingDecls) {
8293 const NamedDecl *ShadowedDecl = Shadow.ShadowedDecl;
8294 // Try to avoid the warning when the shadowed decl isn't captured.
8295 const DeclContext *OldDC = ShadowedDecl->getDeclContext();
8296 if (const auto *VD = dyn_cast<VarDecl>(Val: ShadowedDecl)) {
8297 SourceLocation CaptureLoc = getCaptureLocation(LSI, VD);
8298 Diag(Loc: Shadow.VD->getLocation(),
8299 DiagID: CaptureLoc.isInvalid() ? diag::warn_decl_shadow_uncaptured_local
8300 : diag::warn_decl_shadow)
8301 << Shadow.VD->getDeclName()
8302 << computeShadowedDeclKind(ShadowedDecl, OldDC) << OldDC;
8303 if (CaptureLoc.isValid())
8304 Diag(Loc: CaptureLoc, DiagID: diag::note_var_explicitly_captured_here)
8305 << Shadow.VD->getDeclName() << /*explicitly*/ 0;
8306 Diag(Loc: ShadowedDecl->getLocation(), DiagID: diag::note_previous_declaration);
8307 } else if (isa<FieldDecl>(Val: ShadowedDecl)) {
8308 Diag(Loc: Shadow.VD->getLocation(),
8309 DiagID: LSI->isCXXThisCaptured() ? diag::warn_decl_shadow
8310 : diag::warn_decl_shadow_uncaptured_local)
8311 << Shadow.VD->getDeclName()
8312 << computeShadowedDeclKind(ShadowedDecl, OldDC) << OldDC;
8313 Diag(Loc: ShadowedDecl->getLocation(), DiagID: diag::note_previous_declaration);
8314 }
8315 }
8316}
8317
8318void Sema::CheckShadow(Scope *S, VarDecl *D) {
8319 if (Diags.isIgnored(DiagID: diag::warn_decl_shadow, Loc: D->getLocation()))
8320 return;
8321
8322 LookupResult R(*this, D->getDeclName(), D->getLocation(),
8323 Sema::LookupOrdinaryName,
8324 RedeclarationKind::ForVisibleRedeclaration);
8325 LookupName(R, S);
8326 if (NamedDecl *ShadowedDecl = getShadowedDeclaration(D, R))
8327 CheckShadow(D, ShadowedDecl, R);
8328}
8329
8330/// Check if 'E', which is an expression that is about to be modified, refers
8331/// to a constructor parameter that shadows a field.
8332void Sema::CheckShadowingDeclModification(Expr *E, SourceLocation Loc) {
8333 // Quickly ignore expressions that can't be shadowing ctor parameters.
8334 if (!getLangOpts().CPlusPlus || ShadowingDecls.empty())
8335 return;
8336 E = E->IgnoreParenImpCasts();
8337 auto *DRE = dyn_cast<DeclRefExpr>(Val: E);
8338 if (!DRE)
8339 return;
8340 const NamedDecl *D = cast<NamedDecl>(Val: DRE->getDecl()->getCanonicalDecl());
8341 auto I = ShadowingDecls.find(Val: D);
8342 if (I == ShadowingDecls.end())
8343 return;
8344 const NamedDecl *ShadowedDecl = I->second;
8345 const DeclContext *OldDC = ShadowedDecl->getDeclContext();
8346 Diag(Loc, DiagID: diag::warn_modifying_shadowing_decl) << D << OldDC;
8347 Diag(Loc: D->getLocation(), DiagID: diag::note_var_declared_here) << D;
8348 Diag(Loc: ShadowedDecl->getLocation(), DiagID: diag::note_previous_declaration);
8349
8350 // Avoid issuing multiple warnings about the same decl.
8351 ShadowingDecls.erase(I);
8352}
8353
8354/// Check for conflict between this global or extern "C" declaration and
8355/// previous global or extern "C" declarations. This is only used in C++.
8356template<typename T>
8357static bool checkGlobalOrExternCConflict(
8358 Sema &S, const T *ND, bool IsGlobal, LookupResult &Previous) {
8359 assert(S.getLangOpts().CPlusPlus && "only C++ has extern \"C\"");
8360 NamedDecl *Prev = S.findLocallyScopedExternCDecl(Name: ND->getDeclName());
8361
8362 if (!Prev && IsGlobal && !isIncompleteDeclExternC(S, ND)) {
8363 // The common case: this global doesn't conflict with any extern "C"
8364 // declaration.
8365 return false;
8366 }
8367
8368 if (Prev) {
8369 if (!IsGlobal || isIncompleteDeclExternC(S, ND)) {
8370 // Both the old and new declarations have C language linkage. This is a
8371 // redeclaration.
8372 Previous.clear();
8373 Previous.addDecl(D: Prev);
8374 return true;
8375 }
8376
8377 // This is a global, non-extern "C" declaration, and there is a previous
8378 // non-global extern "C" declaration. Diagnose if this is a variable
8379 // declaration.
8380 if (!isa<VarDecl>(ND))
8381 return false;
8382 } else {
8383 // The declaration is extern "C". Check for any declaration in the
8384 // translation unit which might conflict.
8385 if (IsGlobal) {
8386 // We have already performed the lookup into the translation unit.
8387 IsGlobal = false;
8388 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
8389 I != E; ++I) {
8390 if (isa<VarDecl>(Val: *I)) {
8391 Prev = *I;
8392 break;
8393 }
8394 }
8395 } else {
8396 DeclContext::lookup_result R =
8397 S.Context.getTranslationUnitDecl()->lookup(Name: ND->getDeclName());
8398 for (DeclContext::lookup_result::iterator I = R.begin(), E = R.end();
8399 I != E; ++I) {
8400 if (isa<VarDecl>(Val: *I)) {
8401 Prev = *I;
8402 break;
8403 }
8404 // FIXME: If we have any other entity with this name in global scope,
8405 // the declaration is ill-formed, but that is a defect: it breaks the
8406 // 'stat' hack, for instance. Only variables can have mangled name
8407 // clashes with extern "C" declarations, so only they deserve a
8408 // diagnostic.
8409 }
8410 }
8411
8412 if (!Prev)
8413 return false;
8414 }
8415
8416 // Use the first declaration's location to ensure we point at something which
8417 // is lexically inside an extern "C" linkage-spec.
8418 assert(Prev && "should have found a previous declaration to diagnose");
8419 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: Prev))
8420 Prev = FD->getFirstDecl();
8421 else
8422 Prev = cast<VarDecl>(Val: Prev)->getFirstDecl();
8423
8424 S.Diag(ND->getLocation(), diag::err_extern_c_global_conflict)
8425 << IsGlobal << ND;
8426 S.Diag(Loc: Prev->getLocation(), DiagID: diag::note_extern_c_global_conflict)
8427 << IsGlobal;
8428 return false;
8429}
8430
8431/// Apply special rules for handling extern "C" declarations. Returns \c true
8432/// if we have found that this is a redeclaration of some prior entity.
8433///
8434/// Per C++ [dcl.link]p6:
8435/// Two declarations [for a function or variable] with C language linkage
8436/// with the same name that appear in different scopes refer to the same
8437/// [entity]. An entity with C language linkage shall not be declared with
8438/// the same name as an entity in global scope.
8439template<typename T>
8440static bool checkForConflictWithNonVisibleExternC(Sema &S, const T *ND,
8441 LookupResult &Previous) {
8442 if (!S.getLangOpts().CPlusPlus) {
8443 // In C, when declaring a global variable, look for a corresponding 'extern'
8444 // variable declared in function scope. We don't need this in C++, because
8445 // we find local extern decls in the surrounding file-scope DeclContext.
8446 if (ND->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
8447 if (NamedDecl *Prev = S.findLocallyScopedExternCDecl(Name: ND->getDeclName())) {
8448 Previous.clear();
8449 Previous.addDecl(D: Prev);
8450 return true;
8451 }
8452 }
8453 return false;
8454 }
8455
8456 // A declaration in the translation unit can conflict with an extern "C"
8457 // declaration.
8458 if (ND->getDeclContext()->getRedeclContext()->isTranslationUnit())
8459 return checkGlobalOrExternCConflict(S, ND, /*IsGlobal*/true, Previous);
8460
8461 // An extern "C" declaration can conflict with a declaration in the
8462 // translation unit or can be a redeclaration of an extern "C" declaration
8463 // in another scope.
8464 if (isIncompleteDeclExternC(S,ND))
8465 return checkGlobalOrExternCConflict(S, ND, /*IsGlobal*/false, Previous);
8466
8467 // Neither global nor extern "C": nothing to do.
8468 return false;
8469}
8470
8471static bool CheckC23ConstexprVarType(Sema &SemaRef, SourceLocation VarLoc,
8472 QualType T) {
8473 QualType CanonT = SemaRef.Context.getCanonicalType(T);
8474 // C23 6.7.1p5: An object declared with storage-class specifier constexpr or
8475 // any of its members, even recursively, shall not have an atomic type, or a
8476 // variably modified type, or a type that is volatile or restrict qualified.
8477 if (CanonT->isVariablyModifiedType()) {
8478 SemaRef.Diag(Loc: VarLoc, DiagID: diag::err_c23_constexpr_invalid_type) << T;
8479 return true;
8480 }
8481
8482 // Arrays are qualified by their element type, so get the base type (this
8483 // works on non-arrays as well).
8484 CanonT = SemaRef.Context.getBaseElementType(QT: CanonT);
8485
8486 if (CanonT->isAtomicType() || CanonT.isVolatileQualified() ||
8487 CanonT.isRestrictQualified()) {
8488 SemaRef.Diag(Loc: VarLoc, DiagID: diag::err_c23_constexpr_invalid_type) << T;
8489 return true;
8490 }
8491
8492 if (CanonT->isRecordType()) {
8493 const RecordDecl *RD = CanonT->getAsRecordDecl();
8494 if (llvm::any_of(Range: RD->fields(), P: [&SemaRef, VarLoc](const FieldDecl *F) {
8495 return CheckC23ConstexprVarType(SemaRef, VarLoc, T: F->getType());
8496 }))
8497 return true;
8498 }
8499
8500 return false;
8501}
8502
8503void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
8504 // If the decl is already known invalid, don't check it.
8505 if (NewVD->isInvalidDecl())
8506 return;
8507
8508 QualType T = NewVD->getType();
8509
8510 // Defer checking an 'auto' type until its initializer is attached.
8511 if (T->isUndeducedType())
8512 return;
8513
8514 if (NewVD->hasAttrs())
8515 CheckAlignasUnderalignment(D: NewVD);
8516
8517 if (T->isObjCObjectType()) {
8518 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_statically_allocated_object)
8519 << FixItHint::CreateInsertion(InsertionLoc: NewVD->getLocation(), Code: "*");
8520 T = Context.getObjCObjectPointerType(OIT: T);
8521 NewVD->setType(T);
8522 }
8523
8524 // Emit an error if an address space was applied to decl with local storage.
8525 // This includes arrays of objects with address space qualifiers, but not
8526 // automatic variables that point to other address spaces.
8527 // ISO/IEC TR 18037 S5.1.2
8528 if (!getLangOpts().OpenCL && NewVD->hasLocalStorage() &&
8529 T.getAddressSpace() != LangAS::Default) {
8530 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_as_qualified_auto_decl) << 0;
8531 NewVD->setInvalidDecl();
8532 return;
8533 }
8534
8535 // OpenCL v1.2 s6.8 - The static qualifier is valid only in program
8536 // scope.
8537 if (getLangOpts().OpenCLVersion == 120 &&
8538 !getOpenCLOptions().isAvailableOption(Ext: "cl_clang_storage_class_specifiers",
8539 LO: getLangOpts()) &&
8540 NewVD->isStaticLocal()) {
8541 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_static_function_scope);
8542 NewVD->setInvalidDecl();
8543 return;
8544 }
8545
8546 if (getLangOpts().OpenCL) {
8547 if (!diagnoseOpenCLTypes(Se&: *this, NewVD))
8548 return;
8549
8550 // OpenCL v2.0 s6.12.5 - The __block storage type is not supported.
8551 if (NewVD->hasAttr<BlocksAttr>()) {
8552 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_block_storage_type);
8553 return;
8554 }
8555
8556 if (T->isBlockPointerType()) {
8557 // OpenCL v2.0 s6.12.5 - Any block declaration must be const qualified and
8558 // can't use 'extern' storage class.
8559 if (!T.isConstQualified()) {
8560 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_invalid_block_declaration)
8561 << 0 /*const*/;
8562 NewVD->setInvalidDecl();
8563 return;
8564 }
8565 if (NewVD->hasExternalStorage()) {
8566 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_extern_block_declaration);
8567 NewVD->setInvalidDecl();
8568 return;
8569 }
8570 }
8571
8572 // FIXME: Adding local AS in C++ for OpenCL might make sense.
8573 if (NewVD->isFileVarDecl() || NewVD->isStaticLocal() ||
8574 NewVD->hasExternalStorage()) {
8575 if (!T->isSamplerT() && !T->isDependentType() &&
8576 !(T.getAddressSpace() == LangAS::opencl_constant ||
8577 (T.getAddressSpace() == LangAS::opencl_global &&
8578 getOpenCLOptions().areProgramScopeVariablesSupported(
8579 Opts: getLangOpts())))) {
8580 int Scope = NewVD->isStaticLocal() | NewVD->hasExternalStorage() << 1;
8581 if (getOpenCLOptions().areProgramScopeVariablesSupported(Opts: getLangOpts()))
8582 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_global_invalid_addr_space)
8583 << Scope << "global or constant";
8584 else
8585 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_global_invalid_addr_space)
8586 << Scope << "constant";
8587 NewVD->setInvalidDecl();
8588 return;
8589 }
8590 } else {
8591 if (T.getAddressSpace() == LangAS::opencl_global) {
8592 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_function_variable)
8593 << 1 /*is any function*/ << "global";
8594 NewVD->setInvalidDecl();
8595 return;
8596 }
8597 if (T.getAddressSpace() == LangAS::opencl_constant ||
8598 T.getAddressSpace() == LangAS::opencl_local) {
8599 FunctionDecl *FD = getCurFunctionDecl();
8600 // OpenCL v1.1 s6.5.2 and s6.5.3: no local or constant variables
8601 // in functions.
8602 if (FD && !FD->hasAttr<OpenCLKernelAttr>()) {
8603 if (T.getAddressSpace() == LangAS::opencl_constant)
8604 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_function_variable)
8605 << 0 /*non-kernel only*/ << "constant";
8606 else
8607 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_function_variable)
8608 << 0 /*non-kernel only*/ << "local";
8609 NewVD->setInvalidDecl();
8610 return;
8611 }
8612 // OpenCL v2.0 s6.5.2 and s6.5.3: local and constant variables must be
8613 // in the outermost scope of a kernel function.
8614 if (FD && FD->hasAttr<OpenCLKernelAttr>()) {
8615 if (!getCurScope()->isFunctionScope()) {
8616 if (T.getAddressSpace() == LangAS::opencl_constant)
8617 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_addrspace_scope)
8618 << "constant";
8619 else
8620 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_opencl_addrspace_scope)
8621 << "local";
8622 NewVD->setInvalidDecl();
8623 return;
8624 }
8625 }
8626 } else if (T.getAddressSpace() != LangAS::opencl_private &&
8627 // If we are parsing a template we didn't deduce an addr
8628 // space yet.
8629 T.getAddressSpace() != LangAS::Default) {
8630 // Do not allow other address spaces on automatic variable.
8631 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_as_qualified_auto_decl) << 1;
8632 NewVD->setInvalidDecl();
8633 return;
8634 }
8635 }
8636 }
8637
8638 if (NewVD->hasLocalStorage() && T.isObjCGCWeak()
8639 && !NewVD->hasAttr<BlocksAttr>()) {
8640 if (getLangOpts().getGC() != LangOptions::NonGC)
8641 Diag(Loc: NewVD->getLocation(), DiagID: diag::warn_gc_attribute_weak_on_local);
8642 else {
8643 assert(!getLangOpts().ObjCAutoRefCount);
8644 Diag(Loc: NewVD->getLocation(), DiagID: diag::warn_attribute_weak_on_local);
8645 }
8646 }
8647
8648 // WebAssembly tables must be static with a zero length and can't be
8649 // declared within functions.
8650 if (T->isWebAssemblyTableType()) {
8651 if (getCurScope()->getParent()) { // Parent is null at top-level
8652 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_wasm_table_in_function);
8653 NewVD->setInvalidDecl();
8654 return;
8655 }
8656 if (NewVD->getStorageClass() != SC_Static) {
8657 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_wasm_table_must_be_static);
8658 NewVD->setInvalidDecl();
8659 return;
8660 }
8661 const auto *ATy = dyn_cast<ConstantArrayType>(Val: T.getTypePtr());
8662 if (!ATy || ATy->getZExtSize() != 0) {
8663 Diag(Loc: NewVD->getLocation(),
8664 DiagID: diag::err_typecheck_wasm_table_must_have_zero_length);
8665 NewVD->setInvalidDecl();
8666 return;
8667 }
8668 }
8669
8670 bool isVM = T->isVariablyModifiedType();
8671 if (isVM || NewVD->hasAttr<CleanupAttr>() ||
8672 NewVD->hasAttr<BlocksAttr>())
8673 setFunctionHasBranchProtectedScope();
8674
8675 if ((isVM && NewVD->hasLinkage()) ||
8676 (T->isVariableArrayType() && NewVD->hasGlobalStorage())) {
8677 bool SizeIsNegative;
8678 llvm::APSInt Oversized;
8679 TypeSourceInfo *FixedTInfo = TryToFixInvalidVariablyModifiedTypeSourceInfo(
8680 TInfo: NewVD->getTypeSourceInfo(), Context, SizeIsNegative, Oversized);
8681 QualType FixedT;
8682 if (FixedTInfo && T == NewVD->getTypeSourceInfo()->getType())
8683 FixedT = FixedTInfo->getType();
8684 else if (FixedTInfo) {
8685 // Type and type-as-written are canonically different. We need to fix up
8686 // both types separately.
8687 FixedT = TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative,
8688 Oversized);
8689 }
8690 if ((!FixedTInfo || FixedT.isNull()) && T->isVariableArrayType()) {
8691 const VariableArrayType *VAT = Context.getAsVariableArrayType(T);
8692 // FIXME: This won't give the correct result for
8693 // int a[10][n];
8694 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange();
8695
8696 if (NewVD->isFileVarDecl())
8697 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_vla_decl_in_file_scope)
8698 << SizeRange;
8699 else if (NewVD->isStaticLocal())
8700 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_vla_decl_has_static_storage)
8701 << SizeRange;
8702 else
8703 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_vla_decl_has_extern_linkage)
8704 << SizeRange;
8705 NewVD->setInvalidDecl();
8706 return;
8707 }
8708
8709 if (!FixedTInfo) {
8710 if (NewVD->isFileVarDecl())
8711 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_vm_decl_in_file_scope);
8712 else
8713 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_vm_decl_has_extern_linkage);
8714 NewVD->setInvalidDecl();
8715 return;
8716 }
8717
8718 Diag(Loc: NewVD->getLocation(), DiagID: diag::ext_vla_folded_to_constant);
8719 NewVD->setType(FixedT);
8720 NewVD->setTypeSourceInfo(FixedTInfo);
8721 }
8722
8723 if (T->isVoidType()) {
8724 // C++98 [dcl.stc]p5: The extern specifier can be applied only to the names
8725 // of objects and functions.
8726 if (NewVD->isThisDeclarationADefinition() || getLangOpts().CPlusPlus) {
8727 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_typecheck_decl_incomplete_type)
8728 << T;
8729 NewVD->setInvalidDecl();
8730 return;
8731 }
8732 }
8733
8734 if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) {
8735 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_block_on_nonlocal);
8736 NewVD->setInvalidDecl();
8737 return;
8738 }
8739
8740 if (!NewVD->hasLocalStorage() && T->isSizelessType() &&
8741 !T.isWebAssemblyReferenceType()) {
8742 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_sizeless_nonlocal) << T;
8743 NewVD->setInvalidDecl();
8744 return;
8745 }
8746
8747 if (isVM && NewVD->hasAttr<BlocksAttr>()) {
8748 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_block_on_vm);
8749 NewVD->setInvalidDecl();
8750 return;
8751 }
8752
8753 if (getLangOpts().C23 && NewVD->isConstexpr() &&
8754 CheckC23ConstexprVarType(SemaRef&: *this, VarLoc: NewVD->getLocation(), T)) {
8755 NewVD->setInvalidDecl();
8756 return;
8757 }
8758
8759 if (NewVD->isConstexpr() && !T->isDependentType() &&
8760 RequireLiteralType(Loc: NewVD->getLocation(), T,
8761 DiagID: diag::err_constexpr_var_non_literal)) {
8762 NewVD->setInvalidDecl();
8763 return;
8764 }
8765
8766 // PPC MMA non-pointer types are not allowed as non-local variable types.
8767 if (Context.getTargetInfo().getTriple().isPPC64() &&
8768 !NewVD->isLocalVarDecl() &&
8769 PPC().CheckPPCMMAType(Type: T, TypeLoc: NewVD->getLocation())) {
8770 NewVD->setInvalidDecl();
8771 return;
8772 }
8773
8774 // Check that SVE types are only used in functions with SVE available.
8775 if (T->isSVESizelessBuiltinType() && isa<FunctionDecl>(Val: CurContext)) {
8776 const FunctionDecl *FD = cast<FunctionDecl>(Val: CurContext);
8777 llvm::StringMap<bool> CallerFeatureMap;
8778 Context.getFunctionFeatureMap(FeatureMap&: CallerFeatureMap, FD);
8779
8780 if (!Builtin::evaluateRequiredTargetFeatures(RequiredFatures: "sve", TargetFetureMap: CallerFeatureMap)) {
8781 if (!Builtin::evaluateRequiredTargetFeatures(RequiredFatures: "sme", TargetFetureMap: CallerFeatureMap)) {
8782 Diag(Loc: NewVD->getLocation(), DiagID: diag::err_sve_vector_in_non_sve_target) << T;
8783 NewVD->setInvalidDecl();
8784 return;
8785 } else if (!IsArmStreamingFunction(FD,
8786 /*IncludeLocallyStreaming=*/true)) {
8787 Diag(Loc: NewVD->getLocation(),
8788 DiagID: diag::err_sve_vector_in_non_streaming_function)
8789 << T;
8790 NewVD->setInvalidDecl();
8791 return;
8792 }
8793 }
8794 }
8795
8796 if (T->isRVVSizelessBuiltinType() && isa<FunctionDecl>(Val: CurContext)) {
8797 const FunctionDecl *FD = cast<FunctionDecl>(Val: CurContext);
8798 llvm::StringMap<bool> CallerFeatureMap;
8799 Context.getFunctionFeatureMap(FeatureMap&: CallerFeatureMap, FD);
8800 RISCV().checkRVVTypeSupport(Ty: T, Loc: NewVD->getLocation(), D: cast<Decl>(Val: CurContext),
8801 FeatureMap: CallerFeatureMap);
8802 }
8803}
8804
8805bool Sema::CheckVariableDeclaration(VarDecl *NewVD, LookupResult &Previous) {
8806 CheckVariableDeclarationType(NewVD);
8807
8808 // If the decl is already known invalid, don't check it.
8809 if (NewVD->isInvalidDecl())
8810 return false;
8811
8812 // If we did not find anything by this name, look for a non-visible
8813 // extern "C" declaration with the same name.
8814 if (Previous.empty() &&
8815 checkForConflictWithNonVisibleExternC(S&: *this, ND: NewVD, Previous))
8816 Previous.setShadowed();
8817
8818 if (!Previous.empty()) {
8819 MergeVarDecl(New: NewVD, Previous);
8820 return true;
8821 }
8822 return false;
8823}
8824
8825bool Sema::AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD) {
8826 llvm::SmallPtrSet<const CXXMethodDecl*, 4> Overridden;
8827
8828 // Look for methods in base classes that this method might override.
8829 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false,
8830 /*DetectVirtual=*/false);
8831 auto VisitBase = [&] (const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
8832 CXXRecordDecl *BaseRecord = Specifier->getType()->getAsCXXRecordDecl();
8833 DeclarationName Name = MD->getDeclName();
8834
8835 if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
8836 // We really want to find the base class destructor here.
8837 QualType T = Context.getTypeDeclType(Decl: BaseRecord);
8838 CanQualType CT = Context.getCanonicalType(T);
8839 Name = Context.DeclarationNames.getCXXDestructorName(Ty: CT);
8840 }
8841
8842 for (NamedDecl *BaseND : BaseRecord->lookup(Name)) {
8843 CXXMethodDecl *BaseMD =
8844 dyn_cast<CXXMethodDecl>(Val: BaseND->getCanonicalDecl());
8845 if (!BaseMD || !BaseMD->isVirtual() ||
8846 IsOverride(MD, BaseMD, /*UseMemberUsingDeclRules=*/false,
8847 /*ConsiderCudaAttrs=*/true))
8848 continue;
8849 if (!CheckExplicitObjectOverride(New: MD, Old: BaseMD))
8850 continue;
8851 if (Overridden.insert(Ptr: BaseMD).second) {
8852 MD->addOverriddenMethod(MD: BaseMD);
8853 CheckOverridingFunctionReturnType(New: MD, Old: BaseMD);
8854 CheckOverridingFunctionAttributes(New: MD, Old: BaseMD);
8855 CheckOverridingFunctionExceptionSpec(New: MD, Old: BaseMD);
8856 CheckIfOverriddenFunctionIsMarkedFinal(New: MD, Old: BaseMD);
8857 }
8858
8859 // A method can only override one function from each base class. We
8860 // don't track indirectly overridden methods from bases of bases.
8861 return true;
8862 }
8863
8864 return false;
8865 };
8866
8867 DC->lookupInBases(BaseMatches: VisitBase, Paths);
8868 return !Overridden.empty();
8869}
8870
8871namespace {
8872 // Struct for holding all of the extra arguments needed by
8873 // DiagnoseInvalidRedeclaration to call Sema::ActOnFunctionDeclarator.
8874 struct ActOnFDArgs {
8875 Scope *S;
8876 Declarator &D;
8877 MultiTemplateParamsArg TemplateParamLists;
8878 bool AddToScope;
8879 };
8880} // end anonymous namespace
8881
8882namespace {
8883
8884// Callback to only accept typo corrections that have a non-zero edit distance.
8885// Also only accept corrections that have the same parent decl.
8886class DifferentNameValidatorCCC final : public CorrectionCandidateCallback {
8887 public:
8888 DifferentNameValidatorCCC(ASTContext &Context, FunctionDecl *TypoFD,
8889 CXXRecordDecl *Parent)
8890 : Context(Context), OriginalFD(TypoFD),
8891 ExpectedParent(Parent ? Parent->getCanonicalDecl() : nullptr) {}
8892
8893 bool ValidateCandidate(const TypoCorrection &candidate) override {
8894 if (candidate.getEditDistance() == 0)
8895 return false;
8896
8897 SmallVector<unsigned, 1> MismatchedParams;
8898 for (TypoCorrection::const_decl_iterator CDecl = candidate.begin(),
8899 CDeclEnd = candidate.end();
8900 CDecl != CDeclEnd; ++CDecl) {
8901 FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: *CDecl);
8902
8903 if (FD && !FD->hasBody() &&
8904 hasSimilarParameters(Context, Declaration: FD, Definition: OriginalFD, Params&: MismatchedParams)) {
8905 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Val: FD)) {
8906 CXXRecordDecl *Parent = MD->getParent();
8907 if (Parent && Parent->getCanonicalDecl() == ExpectedParent)
8908 return true;
8909 } else if (!ExpectedParent) {
8910 return true;
8911 }
8912 }
8913 }
8914
8915 return false;
8916 }
8917
8918 std::unique_ptr<CorrectionCandidateCallback> clone() override {
8919 return std::make_unique<DifferentNameValidatorCCC>(args&: *this);
8920 }
8921
8922 private:
8923 ASTContext &Context;
8924 FunctionDecl *OriginalFD;
8925 CXXRecordDecl *ExpectedParent;
8926};
8927
8928} // end anonymous namespace
8929
8930void Sema::MarkTypoCorrectedFunctionDefinition(const NamedDecl *F) {
8931 TypoCorrectedFunctionDefinitions.insert(Ptr: F);
8932}
8933
8934/// Generate diagnostics for an invalid function redeclaration.
8935///
8936/// This routine handles generating the diagnostic messages for an invalid
8937/// function redeclaration, including finding possible similar declarations
8938/// or performing typo correction if there are no previous declarations with
8939/// the same name.
8940///
8941/// Returns a NamedDecl iff typo correction was performed and substituting in
8942/// the new declaration name does not cause new errors.
8943static NamedDecl *DiagnoseInvalidRedeclaration(
8944 Sema &SemaRef, LookupResult &Previous, FunctionDecl *NewFD,
8945 ActOnFDArgs &ExtraArgs, bool IsLocalFriend, Scope *S) {
8946 DeclarationName Name = NewFD->getDeclName();
8947 DeclContext *NewDC = NewFD->getDeclContext();
8948 SmallVector<unsigned, 1> MismatchedParams;
8949 SmallVector<std::pair<FunctionDecl *, unsigned>, 1> NearMatches;
8950 TypoCorrection Correction;
8951 bool IsDefinition = ExtraArgs.D.isFunctionDefinition();
8952 unsigned DiagMsg =
8953 IsLocalFriend ? diag::err_no_matching_local_friend :
8954 NewFD->getFriendObjectKind() ? diag::err_qualified_friend_no_match :
8955 diag::err_member_decl_does_not_match;
8956 LookupResult Prev(SemaRef, Name, NewFD->getLocation(),
8957 IsLocalFriend ? Sema::LookupLocalFriendName
8958 : Sema::LookupOrdinaryName,
8959 RedeclarationKind::ForVisibleRedeclaration);
8960
8961 NewFD->setInvalidDecl();
8962 if (IsLocalFriend)
8963 SemaRef.LookupName(R&: Prev, S);
8964 else
8965 SemaRef.LookupQualifiedName(R&: Prev, LookupCtx: NewDC);
8966 assert(!Prev.isAmbiguous() &&
8967 "Cannot have an ambiguity in previous-declaration lookup");
8968 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Val: NewFD);
8969 DifferentNameValidatorCCC CCC(SemaRef.Context, NewFD,
8970 MD ? MD->getParent() : nullptr);
8971 if (!Prev.empty()) {
8972 for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end();
8973 Func != FuncEnd; ++Func) {
8974 FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: *Func);
8975 if (FD &&
8976 hasSimilarParameters(Context&: SemaRef.Context, Declaration: FD, Definition: NewFD, Params&: MismatchedParams)) {
8977 // Add 1 to the index so that 0 can mean the mismatch didn't
8978 // involve a parameter
8979 unsigned ParamNum =
8980 MismatchedParams.empty() ? 0 : MismatchedParams.front() + 1;
8981 NearMatches.push_back(Elt: std::make_pair(x&: FD, y&: ParamNum));
8982 }
8983 }
8984 // If the qualified name lookup yielded nothing, try typo correction
8985 } else if ((Correction = SemaRef.CorrectTypo(
8986 Typo: Prev.getLookupNameInfo(), LookupKind: Prev.getLookupKind(), S,
8987 SS: &ExtraArgs.D.getCXXScopeSpec(), CCC, Mode: Sema::CTK_ErrorRecovery,
8988 MemberContext: IsLocalFriend ? nullptr : NewDC))) {
8989 // Set up everything for the call to ActOnFunctionDeclarator
8990 ExtraArgs.D.SetIdentifier(Id: Correction.getCorrectionAsIdentifierInfo(),
8991 IdLoc: ExtraArgs.D.getIdentifierLoc());
8992 Previous.clear();
8993 Previous.setLookupName(Correction.getCorrection());
8994 for (TypoCorrection::decl_iterator CDecl = Correction.begin(),
8995 CDeclEnd = Correction.end();
8996 CDecl != CDeclEnd; ++CDecl) {
8997 FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: *CDecl);
8998 if (FD && !FD->hasBody() &&
8999 hasSimilarParameters(Context&: SemaRef.Context, Declaration: FD, Definition: NewFD, Params&: MismatchedParams)) {
9000 Previous.addDecl(D: FD);
9001 }
9002 }
9003 bool wasRedeclaration = ExtraArgs.D.isRedeclaration();
9004
9005 NamedDecl *Result;
9006 // Retry building the function declaration with the new previous
9007 // declarations, and with errors suppressed.
9008 {
9009 // Trap errors.
9010 Sema::SFINAETrap Trap(SemaRef);
9011
9012 // TODO: Refactor ActOnFunctionDeclarator so that we can call only the
9013 // pieces need to verify the typo-corrected C++ declaration and hopefully
9014 // eliminate the need for the parameter pack ExtraArgs.
9015 Result = SemaRef.ActOnFunctionDeclarator(
9016 S: ExtraArgs.S, D&: ExtraArgs.D,
9017 DC: Correction.getCorrectionDecl()->getDeclContext(),
9018 TInfo: NewFD->getTypeSourceInfo(), Previous, TemplateParamLists: ExtraArgs.TemplateParamLists,
9019 AddToScope&: ExtraArgs.AddToScope);
9020
9021 if (Trap.hasErrorOccurred())
9022 Result = nullptr;
9023 }
9024
9025 if (Result) {
9026 // Determine which correction we picked.
9027 Decl *Canonical = Result->getCanonicalDecl();
9028 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
9029 I != E; ++I)
9030 if ((*I)->getCanonicalDecl() == Canonical)
9031 Correction.setCorrectionDecl(*I);
9032
9033 // Let Sema know about the correction.
9034 SemaRef.MarkTypoCorrectedFunctionDefinition(F: Result);
9035 SemaRef.diagnoseTypo(
9036 Correction,
9037 TypoDiag: SemaRef.PDiag(DiagID: IsLocalFriend
9038 ? diag::err_no_matching_local_friend_suggest
9039 : diag::err_member_decl_does_not_match_suggest)
9040 << Name << NewDC << IsDefinition);
9041 return Result;
9042 }
9043
9044 // Pretend the typo correction never occurred
9045 ExtraArgs.D.SetIdentifier(Id: Name.getAsIdentifierInfo(),
9046 IdLoc: ExtraArgs.D.getIdentifierLoc());
9047 ExtraArgs.D.setRedeclaration(wasRedeclaration);
9048 Previous.clear();
9049 Previous.setLookupName(Name);
9050 }
9051
9052 SemaRef.Diag(Loc: NewFD->getLocation(), DiagID: DiagMsg)
9053 << Name << NewDC << IsDefinition << NewFD->getLocation();
9054
9055 bool NewFDisConst = false;
9056 if (CXXMethodDecl *NewMD = dyn_cast<CXXMethodDecl>(Val: NewFD))
9057 NewFDisConst = NewMD->isConst();
9058
9059 for (SmallVectorImpl<std::pair<FunctionDecl *, unsigned> >::iterator
9060 NearMatch = NearMatches.begin(), NearMatchEnd = NearMatches.end();
9061 NearMatch != NearMatchEnd; ++NearMatch) {
9062 FunctionDecl *FD = NearMatch->first;
9063 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Val: FD);
9064 bool FDisConst = MD && MD->isConst();
9065 bool IsMember = MD || !IsLocalFriend;
9066
9067 // FIXME: These notes are poorly worded for the local friend case.
9068 if (unsigned Idx = NearMatch->second) {
9069 ParmVarDecl *FDParam = FD->getParamDecl(i: Idx-1);
9070 SourceLocation Loc = FDParam->getTypeSpecStartLoc();
9071 if (Loc.isInvalid()) Loc = FD->getLocation();
9072 SemaRef.Diag(Loc, DiagID: IsMember ? diag::note_member_def_close_param_match
9073 : diag::note_local_decl_close_param_match)
9074 << Idx << FDParam->getType()
9075 << NewFD->getParamDecl(i: Idx - 1)->getType();
9076 } else if (FDisConst != NewFDisConst) {
9077 auto DB = SemaRef.Diag(Loc: FD->getLocation(),
9078 DiagID: diag::note_member_def_close_const_match)
9079 << NewFDisConst << FD->getSourceRange().getEnd();
9080 if (const auto &FTI = ExtraArgs.D.getFunctionTypeInfo(); !NewFDisConst)
9081 DB << FixItHint::CreateInsertion(InsertionLoc: FTI.getRParenLoc().getLocWithOffset(Offset: 1),
9082 Code: " const");
9083 else if (FTI.hasMethodTypeQualifiers() &&
9084 FTI.getConstQualifierLoc().isValid())
9085 DB << FixItHint::CreateRemoval(RemoveRange: FTI.getConstQualifierLoc());
9086 } else {
9087 SemaRef.Diag(Loc: FD->getLocation(),
9088 DiagID: IsMember ? diag::note_member_def_close_match
9089 : diag::note_local_decl_close_match);
9090 }
9091 }
9092 return nullptr;
9093}
9094
9095static StorageClass getFunctionStorageClass(Sema &SemaRef, Declarator &D) {
9096 switch (D.getDeclSpec().getStorageClassSpec()) {
9097 default: llvm_unreachable("Unknown storage class!");
9098 case DeclSpec::SCS_auto:
9099 case DeclSpec::SCS_register:
9100 case DeclSpec::SCS_mutable:
9101 SemaRef.Diag(Loc: D.getDeclSpec().getStorageClassSpecLoc(),
9102 DiagID: diag::err_typecheck_sclass_func);
9103 D.getMutableDeclSpec().ClearStorageClassSpecs();
9104 D.setInvalidType();
9105 break;
9106 case DeclSpec::SCS_unspecified: break;
9107 case DeclSpec::SCS_extern:
9108 if (D.getDeclSpec().isExternInLinkageSpec())
9109 return SC_None;
9110 return SC_Extern;
9111 case DeclSpec::SCS_static: {
9112 if (SemaRef.CurContext->getRedeclContext()->isFunctionOrMethod()) {
9113 // C99 6.7.1p5:
9114 // The declaration of an identifier for a function that has
9115 // block scope shall have no explicit storage-class specifier
9116 // other than extern
9117 // See also (C++ [dcl.stc]p4).
9118 SemaRef.Diag(Loc: D.getDeclSpec().getStorageClassSpecLoc(),
9119 DiagID: diag::err_static_block_func);
9120 break;
9121 } else
9122 return SC_Static;
9123 }
9124 case DeclSpec::SCS_private_extern: return SC_PrivateExtern;
9125 }
9126
9127 // No explicit storage class has already been returned
9128 return SC_None;
9129}
9130
9131static FunctionDecl *CreateNewFunctionDecl(Sema &SemaRef, Declarator &D,
9132 DeclContext *DC, QualType &R,
9133 TypeSourceInfo *TInfo,
9134 StorageClass SC,
9135 bool &IsVirtualOkay) {
9136 DeclarationNameInfo NameInfo = SemaRef.GetNameForDeclarator(D);
9137 DeclarationName Name = NameInfo.getName();
9138
9139 FunctionDecl *NewFD = nullptr;
9140 bool isInline = D.getDeclSpec().isInlineSpecified();
9141
9142 ConstexprSpecKind ConstexprKind = D.getDeclSpec().getConstexprSpecifier();
9143 if (ConstexprKind == ConstexprSpecKind::Constinit ||
9144 (SemaRef.getLangOpts().C23 &&
9145 ConstexprKind == ConstexprSpecKind::Constexpr)) {
9146
9147 if (SemaRef.getLangOpts().C23)
9148 SemaRef.Diag(Loc: D.getDeclSpec().getConstexprSpecLoc(),
9149 DiagID: diag::err_c23_constexpr_not_variable);
9150 else
9151 SemaRef.Diag(Loc: D.getDeclSpec().getConstexprSpecLoc(),
9152 DiagID: diag::err_constexpr_wrong_decl_kind)
9153 << static_cast<int>(ConstexprKind);
9154 ConstexprKind = ConstexprSpecKind::Unspecified;
9155 D.getMutableDeclSpec().ClearConstexprSpec();
9156 }
9157
9158 if (!SemaRef.getLangOpts().CPlusPlus) {
9159 // Determine whether the function was written with a prototype. This is
9160 // true when:
9161 // - there is a prototype in the declarator, or
9162 // - the type R of the function is some kind of typedef or other non-
9163 // attributed reference to a type name (which eventually refers to a
9164 // function type). Note, we can't always look at the adjusted type to
9165 // check this case because attributes may cause a non-function
9166 // declarator to still have a function type. e.g.,
9167 // typedef void func(int a);
9168 // __attribute__((noreturn)) func other_func; // This has a prototype
9169 bool HasPrototype =
9170 (D.isFunctionDeclarator() && D.getFunctionTypeInfo().hasPrototype) ||
9171 (D.getDeclSpec().isTypeRep() &&
9172 SemaRef.GetTypeFromParser(Ty: D.getDeclSpec().getRepAsType(), TInfo: nullptr)
9173 ->isFunctionProtoType()) ||
9174 (!R->getAsAdjusted<FunctionType>() && R->isFunctionProtoType());
9175 assert(
9176 (HasPrototype || !SemaRef.getLangOpts().requiresStrictPrototypes()) &&
9177 "Strict prototypes are required");
9178
9179 NewFD = FunctionDecl::Create(
9180 C&: SemaRef.Context, DC, StartLoc: D.getBeginLoc(), NameInfo, T: R, TInfo, SC,
9181 UsesFPIntrin: SemaRef.getCurFPFeatures().isFPConstrained(), isInlineSpecified: isInline, hasWrittenPrototype: HasPrototype,
9182 ConstexprKind: ConstexprSpecKind::Unspecified,
9183 /*TrailingRequiresClause=*/nullptr);
9184 if (D.isInvalidType())
9185 NewFD->setInvalidDecl();
9186
9187 return NewFD;
9188 }
9189
9190 ExplicitSpecifier ExplicitSpecifier = D.getDeclSpec().getExplicitSpecifier();
9191 Expr *TrailingRequiresClause = D.getTrailingRequiresClause();
9192
9193 SemaRef.CheckExplicitObjectMemberFunction(DC, D, Name, R);
9194
9195 if (Name.getNameKind() == DeclarationName::CXXConstructorName) {
9196 // This is a C++ constructor declaration.
9197 assert(DC->isRecord() &&
9198 "Constructors can only be declared in a member context");
9199
9200 R = SemaRef.CheckConstructorDeclarator(D, R, SC);
9201 return CXXConstructorDecl::Create(
9202 C&: SemaRef.Context, RD: cast<CXXRecordDecl>(Val: DC), StartLoc: D.getBeginLoc(), NameInfo, T: R,
9203 TInfo, ES: ExplicitSpecifier, UsesFPIntrin: SemaRef.getCurFPFeatures().isFPConstrained(),
9204 isInline, /*isImplicitlyDeclared=*/false, ConstexprKind,
9205 Inherited: InheritedConstructor(), TrailingRequiresClause);
9206
9207 } else if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
9208 // This is a C++ destructor declaration.
9209 if (DC->isRecord()) {
9210 R = SemaRef.CheckDestructorDeclarator(D, R, SC);
9211 CXXRecordDecl *Record = cast<CXXRecordDecl>(Val: DC);
9212 CXXDestructorDecl *NewDD = CXXDestructorDecl::Create(
9213 C&: SemaRef.Context, RD: Record, StartLoc: D.getBeginLoc(), NameInfo, T: R, TInfo,
9214 UsesFPIntrin: SemaRef.getCurFPFeatures().isFPConstrained(), isInline,
9215 /*isImplicitlyDeclared=*/false, ConstexprKind,
9216 TrailingRequiresClause);
9217 // User defined destructors start as not selected if the class definition is still
9218 // not done.
9219 if (Record->isBeingDefined())
9220 NewDD->setIneligibleOrNotSelected(true);
9221
9222 // If the destructor needs an implicit exception specification, set it
9223 // now. FIXME: It'd be nice to be able to create the right type to start
9224 // with, but the type needs to reference the destructor declaration.
9225 if (SemaRef.getLangOpts().CPlusPlus11)
9226 SemaRef.AdjustDestructorExceptionSpec(Destructor: NewDD);
9227
9228 IsVirtualOkay = true;
9229 return NewDD;
9230
9231 } else {
9232 SemaRef.Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_destructor_not_member);
9233 D.setInvalidType();
9234
9235 // Create a FunctionDecl to satisfy the function definition parsing
9236 // code path.
9237 return FunctionDecl::Create(
9238 C&: SemaRef.Context, DC, StartLoc: D.getBeginLoc(), NLoc: D.getIdentifierLoc(), N: Name, T: R,
9239 TInfo, SC, UsesFPIntrin: SemaRef.getCurFPFeatures().isFPConstrained(), isInlineSpecified: isInline,
9240 /*hasPrototype=*/hasWrittenPrototype: true, ConstexprKind, TrailingRequiresClause);
9241 }
9242
9243 } else if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName) {
9244 if (!DC->isRecord()) {
9245 SemaRef.Diag(Loc: D.getIdentifierLoc(),
9246 DiagID: diag::err_conv_function_not_member);
9247 return nullptr;
9248 }
9249
9250 SemaRef.CheckConversionDeclarator(D, R, SC);
9251 if (D.isInvalidType())
9252 return nullptr;
9253
9254 IsVirtualOkay = true;
9255 return CXXConversionDecl::Create(
9256 C&: SemaRef.Context, RD: cast<CXXRecordDecl>(Val: DC), StartLoc: D.getBeginLoc(), NameInfo, T: R,
9257 TInfo, UsesFPIntrin: SemaRef.getCurFPFeatures().isFPConstrained(), isInline,
9258 ES: ExplicitSpecifier, ConstexprKind, EndLocation: SourceLocation(),
9259 TrailingRequiresClause);
9260
9261 } else if (Name.getNameKind() == DeclarationName::CXXDeductionGuideName) {
9262 if (TrailingRequiresClause)
9263 SemaRef.Diag(Loc: TrailingRequiresClause->getBeginLoc(),
9264 DiagID: diag::err_trailing_requires_clause_on_deduction_guide)
9265 << TrailingRequiresClause->getSourceRange();
9266 if (SemaRef.CheckDeductionGuideDeclarator(D, R, SC))
9267 return nullptr;
9268 return CXXDeductionGuideDecl::Create(C&: SemaRef.Context, DC, StartLoc: D.getBeginLoc(),
9269 ES: ExplicitSpecifier, NameInfo, T: R, TInfo,
9270 EndLocation: D.getEndLoc());
9271 } else if (DC->isRecord()) {
9272 // If the name of the function is the same as the name of the record,
9273 // then this must be an invalid constructor that has a return type.
9274 // (The parser checks for a return type and makes the declarator a
9275 // constructor if it has no return type).
9276 if (Name.getAsIdentifierInfo() &&
9277 Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(Val: DC)->getIdentifier()){
9278 SemaRef.Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_constructor_return_type)
9279 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
9280 << SourceRange(D.getIdentifierLoc());
9281 return nullptr;
9282 }
9283
9284 // This is a C++ method declaration.
9285 CXXMethodDecl *Ret = CXXMethodDecl::Create(
9286 C&: SemaRef.Context, RD: cast<CXXRecordDecl>(Val: DC), StartLoc: D.getBeginLoc(), NameInfo, T: R,
9287 TInfo, SC, UsesFPIntrin: SemaRef.getCurFPFeatures().isFPConstrained(), isInline,
9288 ConstexprKind, EndLocation: SourceLocation(), TrailingRequiresClause);
9289 IsVirtualOkay = !Ret->isStatic();
9290 return Ret;
9291 } else {
9292 bool isFriend =
9293 SemaRef.getLangOpts().CPlusPlus && D.getDeclSpec().isFriendSpecified();
9294 if (!isFriend && SemaRef.CurContext->isRecord())
9295 return nullptr;
9296
9297 // Determine whether the function was written with a
9298 // prototype. This true when:
9299 // - we're in C++ (where every function has a prototype),
9300 return FunctionDecl::Create(
9301 C&: SemaRef.Context, DC, StartLoc: D.getBeginLoc(), NameInfo, T: R, TInfo, SC,
9302 UsesFPIntrin: SemaRef.getCurFPFeatures().isFPConstrained(), isInlineSpecified: isInline,
9303 hasWrittenPrototype: true /*HasPrototype*/, ConstexprKind, TrailingRequiresClause);
9304 }
9305}
9306
9307enum OpenCLParamType {
9308 ValidKernelParam,
9309 PtrPtrKernelParam,
9310 PtrKernelParam,
9311 InvalidAddrSpacePtrKernelParam,
9312 InvalidKernelParam,
9313 RecordKernelParam
9314};
9315
9316static bool isOpenCLSizeDependentType(ASTContext &C, QualType Ty) {
9317 // Size dependent types are just typedefs to normal integer types
9318 // (e.g. unsigned long), so we cannot distinguish them from other typedefs to
9319 // integers other than by their names.
9320 StringRef SizeTypeNames[] = {"size_t", "intptr_t", "uintptr_t", "ptrdiff_t"};
9321
9322 // Remove typedefs one by one until we reach a typedef
9323 // for a size dependent type.
9324 QualType DesugaredTy = Ty;
9325 do {
9326 ArrayRef<StringRef> Names(SizeTypeNames);
9327 auto Match = llvm::find(Range&: Names, Val: DesugaredTy.getUnqualifiedType().getAsString());
9328 if (Names.end() != Match)
9329 return true;
9330
9331 Ty = DesugaredTy;
9332 DesugaredTy = Ty.getSingleStepDesugaredType(Context: C);
9333 } while (DesugaredTy != Ty);
9334
9335 return false;
9336}
9337
9338static OpenCLParamType getOpenCLKernelParameterType(Sema &S, QualType PT) {
9339 if (PT->isDependentType())
9340 return InvalidKernelParam;
9341
9342 if (PT->isPointerType() || PT->isReferenceType()) {
9343 QualType PointeeType = PT->getPointeeType();
9344 if (PointeeType.getAddressSpace() == LangAS::opencl_generic ||
9345 PointeeType.getAddressSpace() == LangAS::opencl_private ||
9346 PointeeType.getAddressSpace() == LangAS::Default)
9347 return InvalidAddrSpacePtrKernelParam;
9348
9349 if (PointeeType->isPointerType()) {
9350 // This is a pointer to pointer parameter.
9351 // Recursively check inner type.
9352 OpenCLParamType ParamKind = getOpenCLKernelParameterType(S, PT: PointeeType);
9353 if (ParamKind == InvalidAddrSpacePtrKernelParam ||
9354 ParamKind == InvalidKernelParam)
9355 return ParamKind;
9356
9357 // OpenCL v3.0 s6.11.a:
9358 // A restriction to pass pointers to pointers only applies to OpenCL C
9359 // v1.2 or below.
9360 if (S.getLangOpts().getOpenCLCompatibleVersion() > 120)
9361 return ValidKernelParam;
9362
9363 return PtrPtrKernelParam;
9364 }
9365
9366 // C++ for OpenCL v1.0 s2.4:
9367 // Moreover the types used in parameters of the kernel functions must be:
9368 // Standard layout types for pointer parameters. The same applies to
9369 // reference if an implementation supports them in kernel parameters.
9370 if (S.getLangOpts().OpenCLCPlusPlus &&
9371 !S.getOpenCLOptions().isAvailableOption(
9372 Ext: "__cl_clang_non_portable_kernel_param_types", LO: S.getLangOpts())) {
9373 auto CXXRec = PointeeType.getCanonicalType()->getAsCXXRecordDecl();
9374 bool IsStandardLayoutType = true;
9375 if (CXXRec) {
9376 // If template type is not ODR-used its definition is only available
9377 // in the template definition not its instantiation.
9378 // FIXME: This logic doesn't work for types that depend on template
9379 // parameter (PR58590).
9380 if (!CXXRec->hasDefinition())
9381 CXXRec = CXXRec->getTemplateInstantiationPattern();
9382 if (!CXXRec || !CXXRec->hasDefinition() || !CXXRec->isStandardLayout())
9383 IsStandardLayoutType = false;
9384 }
9385 if (!PointeeType->isAtomicType() && !PointeeType->isVoidType() &&
9386 !IsStandardLayoutType)
9387 return InvalidKernelParam;
9388 }
9389
9390 // OpenCL v1.2 s6.9.p:
9391 // A restriction to pass pointers only applies to OpenCL C v1.2 or below.
9392 if (S.getLangOpts().getOpenCLCompatibleVersion() > 120)
9393 return ValidKernelParam;
9394
9395 return PtrKernelParam;
9396 }
9397
9398 // OpenCL v1.2 s6.9.k:
9399 // Arguments to kernel functions in a program cannot be declared with the
9400 // built-in scalar types bool, half, size_t, ptrdiff_t, intptr_t, and
9401 // uintptr_t or a struct and/or union that contain fields declared to be one
9402 // of these built-in scalar types.
9403 if (isOpenCLSizeDependentType(C&: S.getASTContext(), Ty: PT))
9404 return InvalidKernelParam;
9405
9406 if (PT->isImageType())
9407 return PtrKernelParam;
9408
9409 if (PT->isBooleanType() || PT->isEventT() || PT->isReserveIDT())
9410 return InvalidKernelParam;
9411
9412 // OpenCL extension spec v1.2 s9.5:
9413 // This extension adds support for half scalar and vector types as built-in
9414 // types that can be used for arithmetic operations, conversions etc.
9415 if (!S.getOpenCLOptions().isAvailableOption(Ext: "cl_khr_fp16", LO: S.getLangOpts()) &&
9416 PT->isHalfType())
9417 return InvalidKernelParam;
9418
9419 // Look into an array argument to check if it has a forbidden type.
9420 if (PT->isArrayType()) {
9421 const Type *UnderlyingTy = PT->getPointeeOrArrayElementType();
9422 // Call ourself to check an underlying type of an array. Since the
9423 // getPointeeOrArrayElementType returns an innermost type which is not an
9424 // array, this recursive call only happens once.
9425 return getOpenCLKernelParameterType(S, PT: QualType(UnderlyingTy, 0));
9426 }
9427
9428 // C++ for OpenCL v1.0 s2.4:
9429 // Moreover the types used in parameters of the kernel functions must be:
9430 // Trivial and standard-layout types C++17 [basic.types] (plain old data
9431 // types) for parameters passed by value;
9432 if (S.getLangOpts().OpenCLCPlusPlus &&
9433 !S.getOpenCLOptions().isAvailableOption(
9434 Ext: "__cl_clang_non_portable_kernel_param_types", LO: S.getLangOpts()) &&
9435 !PT->isOpenCLSpecificType() && !PT.isPODType(Context: S.Context))
9436 return InvalidKernelParam;
9437
9438 if (PT->isRecordType())
9439 return RecordKernelParam;
9440
9441 return ValidKernelParam;
9442}
9443
9444static void checkIsValidOpenCLKernelParameter(
9445 Sema &S,
9446 Declarator &D,
9447 ParmVarDecl *Param,
9448 llvm::SmallPtrSetImpl<const Type *> &ValidTypes) {
9449 QualType PT = Param->getType();
9450
9451 // Cache the valid types we encounter to avoid rechecking structs that are
9452 // used again
9453 if (ValidTypes.count(Ptr: PT.getTypePtr()))
9454 return;
9455
9456 switch (getOpenCLKernelParameterType(S, PT)) {
9457 case PtrPtrKernelParam:
9458 // OpenCL v3.0 s6.11.a:
9459 // A kernel function argument cannot be declared as a pointer to a pointer
9460 // type. [...] This restriction only applies to OpenCL C 1.2 or below.
9461 S.Diag(Loc: Param->getLocation(), DiagID: diag::err_opencl_ptrptr_kernel_param);
9462 D.setInvalidType();
9463 return;
9464
9465 case InvalidAddrSpacePtrKernelParam:
9466 // OpenCL v1.0 s6.5:
9467 // __kernel function arguments declared to be a pointer of a type can point
9468 // to one of the following address spaces only : __global, __local or
9469 // __constant.
9470 S.Diag(Loc: Param->getLocation(), DiagID: diag::err_kernel_arg_address_space);
9471 D.setInvalidType();
9472 return;
9473
9474 // OpenCL v1.2 s6.9.k:
9475 // Arguments to kernel functions in a program cannot be declared with the
9476 // built-in scalar types bool, half, size_t, ptrdiff_t, intptr_t, and
9477 // uintptr_t or a struct and/or union that contain fields declared to be
9478 // one of these built-in scalar types.
9479
9480 case InvalidKernelParam:
9481 // OpenCL v1.2 s6.8 n:
9482 // A kernel function argument cannot be declared
9483 // of event_t type.
9484 // Do not diagnose half type since it is diagnosed as invalid argument
9485 // type for any function elsewhere.
9486 if (!PT->isHalfType()) {
9487 S.Diag(Loc: Param->getLocation(), DiagID: diag::err_bad_kernel_param_type) << PT;
9488
9489 // Explain what typedefs are involved.
9490 const TypedefType *Typedef = nullptr;
9491 while ((Typedef = PT->getAs<TypedefType>())) {
9492 SourceLocation Loc = Typedef->getDecl()->getLocation();
9493 // SourceLocation may be invalid for a built-in type.
9494 if (Loc.isValid())
9495 S.Diag(Loc, DiagID: diag::note_entity_declared_at) << PT;
9496 PT = Typedef->desugar();
9497 }
9498 }
9499
9500 D.setInvalidType();
9501 return;
9502
9503 case PtrKernelParam:
9504 case ValidKernelParam:
9505 ValidTypes.insert(Ptr: PT.getTypePtr());
9506 return;
9507
9508 case RecordKernelParam:
9509 break;
9510 }
9511
9512 // Track nested structs we will inspect
9513 SmallVector<const Decl *, 4> VisitStack;
9514
9515 // Track where we are in the nested structs. Items will migrate from
9516 // VisitStack to HistoryStack as we do the DFS for bad field.
9517 SmallVector<const FieldDecl *, 4> HistoryStack;
9518 HistoryStack.push_back(Elt: nullptr);
9519
9520 // At this point we already handled everything except of a RecordType or
9521 // an ArrayType of a RecordType.
9522 assert((PT->isArrayType() || PT->isRecordType()) && "Unexpected type.");
9523 const RecordType *RecTy =
9524 PT->getPointeeOrArrayElementType()->getAs<RecordType>();
9525 const RecordDecl *OrigRecDecl = RecTy->getDecl();
9526
9527 VisitStack.push_back(Elt: RecTy->getDecl());
9528 assert(VisitStack.back() && "First decl null?");
9529
9530 do {
9531 const Decl *Next = VisitStack.pop_back_val();
9532 if (!Next) {
9533 assert(!HistoryStack.empty());
9534 // Found a marker, we have gone up a level
9535 if (const FieldDecl *Hist = HistoryStack.pop_back_val())
9536 ValidTypes.insert(Ptr: Hist->getType().getTypePtr());
9537
9538 continue;
9539 }
9540
9541 // Adds everything except the original parameter declaration (which is not a
9542 // field itself) to the history stack.
9543 const RecordDecl *RD;
9544 if (const FieldDecl *Field = dyn_cast<FieldDecl>(Val: Next)) {
9545 HistoryStack.push_back(Elt: Field);
9546
9547 QualType FieldTy = Field->getType();
9548 // Other field types (known to be valid or invalid) are handled while we
9549 // walk around RecordDecl::fields().
9550 assert((FieldTy->isArrayType() || FieldTy->isRecordType()) &&
9551 "Unexpected type.");
9552 const Type *FieldRecTy = FieldTy->getPointeeOrArrayElementType();
9553
9554 RD = FieldRecTy->castAs<RecordType>()->getDecl();
9555 } else {
9556 RD = cast<RecordDecl>(Val: Next);
9557 }
9558
9559 // Add a null marker so we know when we've gone back up a level
9560 VisitStack.push_back(Elt: nullptr);
9561
9562 for (const auto *FD : RD->fields()) {
9563 QualType QT = FD->getType();
9564
9565 if (ValidTypes.count(Ptr: QT.getTypePtr()))
9566 continue;
9567
9568 OpenCLParamType ParamType = getOpenCLKernelParameterType(S, PT: QT);
9569 if (ParamType == ValidKernelParam)
9570 continue;
9571
9572 if (ParamType == RecordKernelParam) {
9573 VisitStack.push_back(Elt: FD);
9574 continue;
9575 }
9576
9577 // OpenCL v1.2 s6.9.p:
9578 // Arguments to kernel functions that are declared to be a struct or union
9579 // do not allow OpenCL objects to be passed as elements of the struct or
9580 // union. This restriction was lifted in OpenCL v2.0 with the introduction
9581 // of SVM.
9582 if (ParamType == PtrKernelParam || ParamType == PtrPtrKernelParam ||
9583 ParamType == InvalidAddrSpacePtrKernelParam) {
9584 S.Diag(Loc: Param->getLocation(),
9585 DiagID: diag::err_record_with_pointers_kernel_param)
9586 << PT->isUnionType()
9587 << PT;
9588 } else {
9589 S.Diag(Loc: Param->getLocation(), DiagID: diag::err_bad_kernel_param_type) << PT;
9590 }
9591
9592 S.Diag(Loc: OrigRecDecl->getLocation(), DiagID: diag::note_within_field_of_type)
9593 << OrigRecDecl->getDeclName();
9594
9595 // We have an error, now let's go back up through history and show where
9596 // the offending field came from
9597 for (ArrayRef<const FieldDecl *>::const_iterator
9598 I = HistoryStack.begin() + 1,
9599 E = HistoryStack.end();
9600 I != E; ++I) {
9601 const FieldDecl *OuterField = *I;
9602 S.Diag(Loc: OuterField->getLocation(), DiagID: diag::note_within_field_of_type)
9603 << OuterField->getType();
9604 }
9605
9606 S.Diag(Loc: FD->getLocation(), DiagID: diag::note_illegal_field_declared_here)
9607 << QT->isPointerType()
9608 << QT;
9609 D.setInvalidType();
9610 return;
9611 }
9612 } while (!VisitStack.empty());
9613}
9614
9615/// Find the DeclContext in which a tag is implicitly declared if we see an
9616/// elaborated type specifier in the specified context, and lookup finds
9617/// nothing.
9618static DeclContext *getTagInjectionContext(DeclContext *DC) {
9619 while (!DC->isFileContext() && !DC->isFunctionOrMethod())
9620 DC = DC->getParent();
9621 return DC;
9622}
9623
9624/// Find the Scope in which a tag is implicitly declared if we see an
9625/// elaborated type specifier in the specified context, and lookup finds
9626/// nothing.
9627static Scope *getTagInjectionScope(Scope *S, const LangOptions &LangOpts) {
9628 while (S->isClassScope() ||
9629 (LangOpts.CPlusPlus &&
9630 S->isFunctionPrototypeScope()) ||
9631 ((S->getFlags() & Scope::DeclScope) == 0) ||
9632 (S->getEntity() && S->getEntity()->isTransparentContext()))
9633 S = S->getParent();
9634 return S;
9635}
9636
9637/// Determine whether a declaration matches a known function in namespace std.
9638static bool isStdBuiltin(ASTContext &Ctx, FunctionDecl *FD,
9639 unsigned BuiltinID) {
9640 switch (BuiltinID) {
9641 case Builtin::BI__GetExceptionInfo:
9642 // No type checking whatsoever.
9643 return Ctx.getTargetInfo().getCXXABI().isMicrosoft();
9644
9645 case Builtin::BIaddressof:
9646 case Builtin::BI__addressof:
9647 case Builtin::BIforward:
9648 case Builtin::BIforward_like:
9649 case Builtin::BImove:
9650 case Builtin::BImove_if_noexcept:
9651 case Builtin::BIas_const: {
9652 // Ensure that we don't treat the algorithm
9653 // OutputIt std::move(InputIt, InputIt, OutputIt)
9654 // as the builtin std::move.
9655 const auto *FPT = FD->getType()->castAs<FunctionProtoType>();
9656 return FPT->getNumParams() == 1 && !FPT->isVariadic();
9657 }
9658
9659 default:
9660 return false;
9661 }
9662}
9663
9664NamedDecl*
9665Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
9666 TypeSourceInfo *TInfo, LookupResult &Previous,
9667 MultiTemplateParamsArg TemplateParamListsRef,
9668 bool &AddToScope) {
9669 QualType R = TInfo->getType();
9670
9671 assert(R->isFunctionType());
9672 if (R.getCanonicalType()->castAs<FunctionType>()->getCmseNSCallAttr())
9673 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_function_decl_cmse_ns_call);
9674
9675 SmallVector<TemplateParameterList *, 4> TemplateParamLists;
9676 llvm::append_range(C&: TemplateParamLists, R&: TemplateParamListsRef);
9677 if (TemplateParameterList *Invented = D.getInventedTemplateParameterList()) {
9678 if (!TemplateParamLists.empty() && !TemplateParamLists.back()->empty() &&
9679 Invented->getDepth() == TemplateParamLists.back()->getDepth())
9680 TemplateParamLists.back() = Invented;
9681 else
9682 TemplateParamLists.push_back(Elt: Invented);
9683 }
9684
9685 // TODO: consider using NameInfo for diagnostic.
9686 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
9687 DeclarationName Name = NameInfo.getName();
9688 StorageClass SC = getFunctionStorageClass(SemaRef&: *this, D);
9689
9690 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
9691 Diag(Loc: D.getDeclSpec().getThreadStorageClassSpecLoc(),
9692 DiagID: diag::err_invalid_thread)
9693 << DeclSpec::getSpecifierName(S: TSCS);
9694
9695 if (D.isFirstDeclarationOfMember())
9696 adjustMemberFunctionCC(
9697 T&: R, HasThisPointer: !(D.isStaticMember() || D.isExplicitObjectMemberFunction()),
9698 IsCtorOrDtor: D.isCtorOrDtor(), Loc: D.getIdentifierLoc());
9699
9700 bool isFriend = false;
9701 FunctionTemplateDecl *FunctionTemplate = nullptr;
9702 bool isMemberSpecialization = false;
9703 bool isFunctionTemplateSpecialization = false;
9704
9705 bool HasExplicitTemplateArgs = false;
9706 TemplateArgumentListInfo TemplateArgs;
9707
9708 bool isVirtualOkay = false;
9709
9710 DeclContext *OriginalDC = DC;
9711 bool IsLocalExternDecl = adjustContextForLocalExternDecl(DC);
9712
9713 FunctionDecl *NewFD = CreateNewFunctionDecl(SemaRef&: *this, D, DC, R, TInfo, SC,
9714 IsVirtualOkay&: isVirtualOkay);
9715 if (!NewFD) return nullptr;
9716
9717 if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer())
9718 NewFD->setTopLevelDeclInObjCContainer();
9719
9720 // Set the lexical context. If this is a function-scope declaration, or has a
9721 // C++ scope specifier, or is the object of a friend declaration, the lexical
9722 // context will be different from the semantic context.
9723 NewFD->setLexicalDeclContext(CurContext);
9724
9725 if (IsLocalExternDecl)
9726 NewFD->setLocalExternDecl();
9727
9728 if (getLangOpts().CPlusPlus) {
9729 // The rules for implicit inlines changed in C++20 for methods and friends
9730 // with an in-class definition (when such a definition is not attached to
9731 // the global module). User-specified 'inline' overrides this (set when
9732 // the function decl is created above).
9733 // FIXME: We need a better way to separate C++ standard and clang modules.
9734 bool ImplicitInlineCXX20 = !getLangOpts().CPlusPlusModules ||
9735 !NewFD->getOwningModule() ||
9736 NewFD->isFromExplicitGlobalModule() ||
9737 NewFD->getOwningModule()->isHeaderLikeModule();
9738 bool isInline = D.getDeclSpec().isInlineSpecified();
9739 bool isVirtual = D.getDeclSpec().isVirtualSpecified();
9740 bool hasExplicit = D.getDeclSpec().hasExplicitSpecifier();
9741 isFriend = D.getDeclSpec().isFriendSpecified();
9742 if (isFriend && !isInline && D.isFunctionDefinition()) {
9743 // Pre-C++20 [class.friend]p5
9744 // A function can be defined in a friend declaration of a
9745 // class . . . . Such a function is implicitly inline.
9746 // Post C++20 [class.friend]p7
9747 // Such a function is implicitly an inline function if it is attached
9748 // to the global module.
9749 NewFD->setImplicitlyInline(ImplicitInlineCXX20);
9750 }
9751
9752 // If this is a method defined in an __interface, and is not a constructor
9753 // or an overloaded operator, then set the pure flag (isVirtual will already
9754 // return true).
9755 if (const CXXRecordDecl *Parent =
9756 dyn_cast<CXXRecordDecl>(Val: NewFD->getDeclContext())) {
9757 if (Parent->isInterface() && cast<CXXMethodDecl>(Val: NewFD)->isUserProvided())
9758 NewFD->setIsPureVirtual(true);
9759
9760 // C++ [class.union]p2
9761 // A union can have member functions, but not virtual functions.
9762 if (isVirtual && Parent->isUnion()) {
9763 Diag(Loc: D.getDeclSpec().getVirtualSpecLoc(), DiagID: diag::err_virtual_in_union);
9764 NewFD->setInvalidDecl();
9765 }
9766 if ((Parent->isClass() || Parent->isStruct()) &&
9767 Parent->hasAttr<SYCLSpecialClassAttr>() &&
9768 NewFD->getKind() == Decl::Kind::CXXMethod && NewFD->getIdentifier() &&
9769 NewFD->getName() == "__init" && D.isFunctionDefinition()) {
9770 if (auto *Def = Parent->getDefinition())
9771 Def->setInitMethod(true);
9772 }
9773 }
9774
9775 SetNestedNameSpecifier(S&: *this, DD: NewFD, D);
9776 isMemberSpecialization = false;
9777 isFunctionTemplateSpecialization = false;
9778 if (D.isInvalidType())
9779 NewFD->setInvalidDecl();
9780
9781 // Match up the template parameter lists with the scope specifier, then
9782 // determine whether we have a template or a template specialization.
9783 bool Invalid = false;
9784 TemplateIdAnnotation *TemplateId =
9785 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
9786 ? D.getName().TemplateId
9787 : nullptr;
9788 TemplateParameterList *TemplateParams =
9789 MatchTemplateParametersToScopeSpecifier(
9790 DeclStartLoc: D.getDeclSpec().getBeginLoc(), DeclLoc: D.getIdentifierLoc(),
9791 SS: D.getCXXScopeSpec(), TemplateId, ParamLists: TemplateParamLists, IsFriend: isFriend,
9792 IsMemberSpecialization&: isMemberSpecialization, Invalid);
9793 if (TemplateParams) {
9794 // Check that we can declare a template here.
9795 if (CheckTemplateDeclScope(S, TemplateParams))
9796 NewFD->setInvalidDecl();
9797
9798 if (TemplateParams->size() > 0) {
9799 // This is a function template
9800
9801 // A destructor cannot be a template.
9802 if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
9803 Diag(Loc: NewFD->getLocation(), DiagID: diag::err_destructor_template);
9804 NewFD->setInvalidDecl();
9805 // Function template with explicit template arguments.
9806 } else if (TemplateId) {
9807 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_function_template_partial_spec)
9808 << SourceRange(TemplateId->LAngleLoc, TemplateId->RAngleLoc);
9809 NewFD->setInvalidDecl();
9810 }
9811
9812 // If we're adding a template to a dependent context, we may need to
9813 // rebuilding some of the types used within the template parameter list,
9814 // now that we know what the current instantiation is.
9815 if (DC->isDependentContext()) {
9816 ContextRAII SavedContext(*this, DC);
9817 if (RebuildTemplateParamsInCurrentInstantiation(Params: TemplateParams))
9818 Invalid = true;
9819 }
9820
9821 FunctionTemplate = FunctionTemplateDecl::Create(C&: Context, DC,
9822 L: NewFD->getLocation(),
9823 Name, Params: TemplateParams,
9824 Decl: NewFD);
9825 FunctionTemplate->setLexicalDeclContext(CurContext);
9826 NewFD->setDescribedFunctionTemplate(FunctionTemplate);
9827
9828 // For source fidelity, store the other template param lists.
9829 if (TemplateParamLists.size() > 1) {
9830 NewFD->setTemplateParameterListsInfo(Context,
9831 TPLists: ArrayRef<TemplateParameterList *>(TemplateParamLists)
9832 .drop_back(N: 1));
9833 }
9834 } else {
9835 // This is a function template specialization.
9836 isFunctionTemplateSpecialization = true;
9837 // For source fidelity, store all the template param lists.
9838 if (TemplateParamLists.size() > 0)
9839 NewFD->setTemplateParameterListsInfo(Context, TPLists: TemplateParamLists);
9840
9841 // C++0x [temp.expl.spec]p20 forbids "template<> friend void foo(int);".
9842 if (isFriend) {
9843 // We want to remove the "template<>", found here.
9844 SourceRange RemoveRange = TemplateParams->getSourceRange();
9845
9846 // If we remove the template<> and the name is not a
9847 // template-id, we're actually silently creating a problem:
9848 // the friend declaration will refer to an untemplated decl,
9849 // and clearly the user wants a template specialization. So
9850 // we need to insert '<>' after the name.
9851 SourceLocation InsertLoc;
9852 if (D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) {
9853 InsertLoc = D.getName().getSourceRange().getEnd();
9854 InsertLoc = getLocForEndOfToken(Loc: InsertLoc);
9855 }
9856
9857 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_template_spec_decl_friend)
9858 << Name << RemoveRange
9859 << FixItHint::CreateRemoval(RemoveRange)
9860 << FixItHint::CreateInsertion(InsertionLoc: InsertLoc, Code: "<>");
9861 Invalid = true;
9862
9863 // Recover by faking up an empty template argument list.
9864 HasExplicitTemplateArgs = true;
9865 TemplateArgs.setLAngleLoc(InsertLoc);
9866 TemplateArgs.setRAngleLoc(InsertLoc);
9867 }
9868 }
9869 } else {
9870 // Check that we can declare a template here.
9871 if (!TemplateParamLists.empty() && isMemberSpecialization &&
9872 CheckTemplateDeclScope(S, TemplateParams: TemplateParamLists.back()))
9873 NewFD->setInvalidDecl();
9874
9875 // All template param lists were matched against the scope specifier:
9876 // this is NOT (an explicit specialization of) a template.
9877 if (TemplateParamLists.size() > 0)
9878 // For source fidelity, store all the template param lists.
9879 NewFD->setTemplateParameterListsInfo(Context, TPLists: TemplateParamLists);
9880
9881 // "friend void foo<>(int);" is an implicit specialization decl.
9882 if (isFriend && TemplateId)
9883 isFunctionTemplateSpecialization = true;
9884 }
9885
9886 // If this is a function template specialization and the unqualified-id of
9887 // the declarator-id is a template-id, convert the template argument list
9888 // into our AST format and check for unexpanded packs.
9889 if (isFunctionTemplateSpecialization && TemplateId) {
9890 HasExplicitTemplateArgs = true;
9891
9892 TemplateArgs.setLAngleLoc(TemplateId->LAngleLoc);
9893 TemplateArgs.setRAngleLoc(TemplateId->RAngleLoc);
9894 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
9895 TemplateId->NumArgs);
9896 translateTemplateArguments(In: TemplateArgsPtr, Out&: TemplateArgs);
9897
9898 // FIXME: Should we check for unexpanded packs if this was an (invalid)
9899 // declaration of a function template partial specialization? Should we
9900 // consider the unexpanded pack context to be a partial specialization?
9901 for (const TemplateArgumentLoc &ArgLoc : TemplateArgs.arguments()) {
9902 if (DiagnoseUnexpandedParameterPack(
9903 Arg: ArgLoc, UPPC: isFriend ? UPPC_FriendDeclaration
9904 : UPPC_ExplicitSpecialization))
9905 NewFD->setInvalidDecl();
9906 }
9907 }
9908
9909 if (Invalid) {
9910 NewFD->setInvalidDecl();
9911 if (FunctionTemplate)
9912 FunctionTemplate->setInvalidDecl();
9913 }
9914
9915 // C++ [dcl.fct.spec]p5:
9916 // The virtual specifier shall only be used in declarations of
9917 // nonstatic class member functions that appear within a
9918 // member-specification of a class declaration; see 10.3.
9919 //
9920 if (isVirtual && !NewFD->isInvalidDecl()) {
9921 if (!isVirtualOkay) {
9922 Diag(Loc: D.getDeclSpec().getVirtualSpecLoc(),
9923 DiagID: diag::err_virtual_non_function);
9924 } else if (!CurContext->isRecord()) {
9925 // 'virtual' was specified outside of the class.
9926 Diag(Loc: D.getDeclSpec().getVirtualSpecLoc(),
9927 DiagID: diag::err_virtual_out_of_class)
9928 << FixItHint::CreateRemoval(RemoveRange: D.getDeclSpec().getVirtualSpecLoc());
9929 } else if (NewFD->getDescribedFunctionTemplate()) {
9930 // C++ [temp.mem]p3:
9931 // A member function template shall not be virtual.
9932 Diag(Loc: D.getDeclSpec().getVirtualSpecLoc(),
9933 DiagID: diag::err_virtual_member_function_template)
9934 << FixItHint::CreateRemoval(RemoveRange: D.getDeclSpec().getVirtualSpecLoc());
9935 } else {
9936 // Okay: Add virtual to the method.
9937 NewFD->setVirtualAsWritten(true);
9938 }
9939
9940 if (getLangOpts().CPlusPlus14 &&
9941 NewFD->getReturnType()->isUndeducedType())
9942 Diag(Loc: D.getDeclSpec().getVirtualSpecLoc(), DiagID: diag::err_auto_fn_virtual);
9943 }
9944
9945 // C++ [dcl.fct.spec]p3:
9946 // The inline specifier shall not appear on a block scope function
9947 // declaration.
9948 if (isInline && !NewFD->isInvalidDecl()) {
9949 if (CurContext->isFunctionOrMethod()) {
9950 // 'inline' is not allowed on block scope function declaration.
9951 Diag(Loc: D.getDeclSpec().getInlineSpecLoc(),
9952 DiagID: diag::err_inline_declaration_block_scope) << Name
9953 << FixItHint::CreateRemoval(RemoveRange: D.getDeclSpec().getInlineSpecLoc());
9954 }
9955 }
9956
9957 // C++ [dcl.fct.spec]p6:
9958 // The explicit specifier shall be used only in the declaration of a
9959 // constructor or conversion function within its class definition;
9960 // see 12.3.1 and 12.3.2.
9961 if (hasExplicit && !NewFD->isInvalidDecl() &&
9962 !isa<CXXDeductionGuideDecl>(Val: NewFD)) {
9963 if (!CurContext->isRecord()) {
9964 // 'explicit' was specified outside of the class.
9965 Diag(Loc: D.getDeclSpec().getExplicitSpecLoc(),
9966 DiagID: diag::err_explicit_out_of_class)
9967 << FixItHint::CreateRemoval(RemoveRange: D.getDeclSpec().getExplicitSpecRange());
9968 } else if (!isa<CXXConstructorDecl>(Val: NewFD) &&
9969 !isa<CXXConversionDecl>(Val: NewFD)) {
9970 // 'explicit' was specified on a function that wasn't a constructor
9971 // or conversion function.
9972 Diag(Loc: D.getDeclSpec().getExplicitSpecLoc(),
9973 DiagID: diag::err_explicit_non_ctor_or_conv_function)
9974 << FixItHint::CreateRemoval(RemoveRange: D.getDeclSpec().getExplicitSpecRange());
9975 }
9976 }
9977
9978 ConstexprSpecKind ConstexprKind = D.getDeclSpec().getConstexprSpecifier();
9979 if (ConstexprKind != ConstexprSpecKind::Unspecified) {
9980 // C++11 [dcl.constexpr]p2: constexpr functions and constexpr constructors
9981 // are implicitly inline.
9982 NewFD->setImplicitlyInline();
9983
9984 // C++11 [dcl.constexpr]p3: functions declared constexpr are required to
9985 // be either constructors or to return a literal type. Therefore,
9986 // destructors cannot be declared constexpr.
9987 if (isa<CXXDestructorDecl>(Val: NewFD) &&
9988 (!getLangOpts().CPlusPlus20 ||
9989 ConstexprKind == ConstexprSpecKind::Consteval)) {
9990 Diag(Loc: D.getDeclSpec().getConstexprSpecLoc(), DiagID: diag::err_constexpr_dtor)
9991 << static_cast<int>(ConstexprKind);
9992 NewFD->setConstexprKind(getLangOpts().CPlusPlus20
9993 ? ConstexprSpecKind::Unspecified
9994 : ConstexprSpecKind::Constexpr);
9995 }
9996 // C++20 [dcl.constexpr]p2: An allocation function, or a
9997 // deallocation function shall not be declared with the consteval
9998 // specifier.
9999 if (ConstexprKind == ConstexprSpecKind::Consteval &&
10000 (NewFD->getOverloadedOperator() == OO_New ||
10001 NewFD->getOverloadedOperator() == OO_Array_New ||
10002 NewFD->getOverloadedOperator() == OO_Delete ||
10003 NewFD->getOverloadedOperator() == OO_Array_Delete)) {
10004 Diag(Loc: D.getDeclSpec().getConstexprSpecLoc(),
10005 DiagID: diag::err_invalid_consteval_decl_kind)
10006 << NewFD;
10007 NewFD->setConstexprKind(ConstexprSpecKind::Constexpr);
10008 }
10009 }
10010
10011 // If __module_private__ was specified, mark the function accordingly.
10012 if (D.getDeclSpec().isModulePrivateSpecified()) {
10013 if (isFunctionTemplateSpecialization) {
10014 SourceLocation ModulePrivateLoc
10015 = D.getDeclSpec().getModulePrivateSpecLoc();
10016 Diag(Loc: ModulePrivateLoc, DiagID: diag::err_module_private_specialization)
10017 << 0
10018 << FixItHint::CreateRemoval(RemoveRange: ModulePrivateLoc);
10019 } else {
10020 NewFD->setModulePrivate();
10021 if (FunctionTemplate)
10022 FunctionTemplate->setModulePrivate();
10023 }
10024 }
10025
10026 if (isFriend) {
10027 if (FunctionTemplate) {
10028 FunctionTemplate->setObjectOfFriendDecl();
10029 FunctionTemplate->setAccess(AS_public);
10030 }
10031 NewFD->setObjectOfFriendDecl();
10032 NewFD->setAccess(AS_public);
10033 }
10034
10035 // If a function is defined as defaulted or deleted, mark it as such now.
10036 // We'll do the relevant checks on defaulted / deleted functions later.
10037 switch (D.getFunctionDefinitionKind()) {
10038 case FunctionDefinitionKind::Declaration:
10039 case FunctionDefinitionKind::Definition:
10040 break;
10041
10042 case FunctionDefinitionKind::Defaulted:
10043 NewFD->setDefaulted();
10044 break;
10045
10046 case FunctionDefinitionKind::Deleted:
10047 NewFD->setDeletedAsWritten();
10048 break;
10049 }
10050
10051 if (isa<CXXMethodDecl>(Val: NewFD) && DC == CurContext &&
10052 D.isFunctionDefinition() && !isInline) {
10053 // Pre C++20 [class.mfct]p2:
10054 // A member function may be defined (8.4) in its class definition, in
10055 // which case it is an inline member function (7.1.2)
10056 // Post C++20 [class.mfct]p1:
10057 // If a member function is attached to the global module and is defined
10058 // in its class definition, it is inline.
10059 NewFD->setImplicitlyInline(ImplicitInlineCXX20);
10060 }
10061
10062 if (!isFriend && SC != SC_None) {
10063 // C++ [temp.expl.spec]p2:
10064 // The declaration in an explicit-specialization shall not be an
10065 // export-declaration. An explicit specialization shall not use a
10066 // storage-class-specifier other than thread_local.
10067 //
10068 // We diagnose friend declarations with storage-class-specifiers
10069 // elsewhere.
10070 if (isFunctionTemplateSpecialization || isMemberSpecialization) {
10071 Diag(Loc: D.getDeclSpec().getStorageClassSpecLoc(),
10072 DiagID: diag::ext_explicit_specialization_storage_class)
10073 << FixItHint::CreateRemoval(
10074 RemoveRange: D.getDeclSpec().getStorageClassSpecLoc());
10075 }
10076
10077 if (SC == SC_Static && !CurContext->isRecord() && DC->isRecord()) {
10078 assert(isa<CXXMethodDecl>(NewFD) &&
10079 "Out-of-line member function should be a CXXMethodDecl");
10080 // C++ [class.static]p1:
10081 // A data or function member of a class may be declared static
10082 // in a class definition, in which case it is a static member of
10083 // the class.
10084
10085 // Complain about the 'static' specifier if it's on an out-of-line
10086 // member function definition.
10087
10088 // MSVC permits the use of a 'static' storage specifier on an
10089 // out-of-line member function template declaration and class member
10090 // template declaration (MSVC versions before 2015), warn about this.
10091 Diag(Loc: D.getDeclSpec().getStorageClassSpecLoc(),
10092 DiagID: ((!getLangOpts().isCompatibleWithMSVC(MajorVersion: LangOptions::MSVC2015) &&
10093 cast<CXXRecordDecl>(Val: DC)->getDescribedClassTemplate()) ||
10094 (getLangOpts().MSVCCompat &&
10095 NewFD->getDescribedFunctionTemplate()))
10096 ? diag::ext_static_out_of_line
10097 : diag::err_static_out_of_line)
10098 << FixItHint::CreateRemoval(
10099 RemoveRange: D.getDeclSpec().getStorageClassSpecLoc());
10100 }
10101 }
10102
10103 // C++11 [except.spec]p15:
10104 // A deallocation function with no exception-specification is treated
10105 // as if it were specified with noexcept(true).
10106 const FunctionProtoType *FPT = R->getAs<FunctionProtoType>();
10107 if ((Name.getCXXOverloadedOperator() == OO_Delete ||
10108 Name.getCXXOverloadedOperator() == OO_Array_Delete) &&
10109 getLangOpts().CPlusPlus11 && FPT && !FPT->hasExceptionSpec())
10110 NewFD->setType(Context.getFunctionType(
10111 ResultTy: FPT->getReturnType(), Args: FPT->getParamTypes(),
10112 EPI: FPT->getExtProtoInfo().withExceptionSpec(ESI: EST_BasicNoexcept)));
10113
10114 // C++20 [dcl.inline]/7
10115 // If an inline function or variable that is attached to a named module
10116 // is declared in a definition domain, it shall be defined in that
10117 // domain.
10118 // So, if the current declaration does not have a definition, we must
10119 // check at the end of the TU (or when the PMF starts) to see that we
10120 // have a definition at that point.
10121 if (isInline && !D.isFunctionDefinition() && getLangOpts().CPlusPlus20 &&
10122 NewFD->isInNamedModule()) {
10123 PendingInlineFuncDecls.insert(Ptr: NewFD);
10124 }
10125 }
10126
10127 // Filter out previous declarations that don't match the scope.
10128 FilterLookupForScope(R&: Previous, Ctx: OriginalDC, S, ConsiderLinkage: shouldConsiderLinkage(FD: NewFD),
10129 AllowInlineNamespace: D.getCXXScopeSpec().isNotEmpty() ||
10130 isMemberSpecialization ||
10131 isFunctionTemplateSpecialization);
10132
10133 // Handle GNU asm-label extension (encoded as an attribute).
10134 if (Expr *E = (Expr*) D.getAsmLabel()) {
10135 // The parser guarantees this is a string.
10136 StringLiteral *SE = cast<StringLiteral>(Val: E);
10137 NewFD->addAttr(A: AsmLabelAttr::Create(Ctx&: Context, Label: SE->getString(),
10138 /*IsLiteralLabel=*/true,
10139 Range: SE->getStrTokenLoc(TokNum: 0)));
10140 } else if (!ExtnameUndeclaredIdentifiers.empty()) {
10141 llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
10142 ExtnameUndeclaredIdentifiers.find(Val: NewFD->getIdentifier());
10143 if (I != ExtnameUndeclaredIdentifiers.end()) {
10144 if (isDeclExternC(D: NewFD)) {
10145 NewFD->addAttr(A: I->second);
10146 ExtnameUndeclaredIdentifiers.erase(I);
10147 } else
10148 Diag(Loc: NewFD->getLocation(), DiagID: diag::warn_redefine_extname_not_applied)
10149 << /*Variable*/0 << NewFD;
10150 }
10151 }
10152
10153 // Copy the parameter declarations from the declarator D to the function
10154 // declaration NewFD, if they are available. First scavenge them into Params.
10155 SmallVector<ParmVarDecl*, 16> Params;
10156 unsigned FTIIdx;
10157 if (D.isFunctionDeclarator(idx&: FTIIdx)) {
10158 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(i: FTIIdx).Fun;
10159
10160 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs
10161 // function that takes no arguments, not a function that takes a
10162 // single void argument.
10163 // We let through "const void" here because Sema::GetTypeForDeclarator
10164 // already checks for that case.
10165 if (FTIHasNonVoidParameters(FTI) && FTI.Params[0].Param) {
10166 for (unsigned i = 0, e = FTI.NumParams; i != e; ++i) {
10167 ParmVarDecl *Param = cast<ParmVarDecl>(Val: FTI.Params[i].Param);
10168 assert(Param->getDeclContext() != NewFD && "Was set before ?");
10169 Param->setDeclContext(NewFD);
10170 Params.push_back(Elt: Param);
10171
10172 if (Param->isInvalidDecl())
10173 NewFD->setInvalidDecl();
10174 }
10175 }
10176
10177 if (!getLangOpts().CPlusPlus) {
10178 // In C, find all the tag declarations from the prototype and move them
10179 // into the function DeclContext. Remove them from the surrounding tag
10180 // injection context of the function, which is typically but not always
10181 // the TU.
10182 DeclContext *PrototypeTagContext =
10183 getTagInjectionContext(DC: NewFD->getLexicalDeclContext());
10184 for (NamedDecl *NonParmDecl : FTI.getDeclsInPrototype()) {
10185 auto *TD = dyn_cast<TagDecl>(Val: NonParmDecl);
10186
10187 // We don't want to reparent enumerators. Look at their parent enum
10188 // instead.
10189 if (!TD) {
10190 if (auto *ECD = dyn_cast<EnumConstantDecl>(Val: NonParmDecl))
10191 TD = cast<EnumDecl>(Val: ECD->getDeclContext());
10192 }
10193 if (!TD)
10194 continue;
10195 DeclContext *TagDC = TD->getLexicalDeclContext();
10196 if (!TagDC->containsDecl(D: TD))
10197 continue;
10198 TagDC->removeDecl(D: TD);
10199 TD->setDeclContext(NewFD);
10200 NewFD->addDecl(D: TD);
10201
10202 // Preserve the lexical DeclContext if it is not the surrounding tag
10203 // injection context of the FD. In this example, the semantic context of
10204 // E will be f and the lexical context will be S, while both the
10205 // semantic and lexical contexts of S will be f:
10206 // void f(struct S { enum E { a } f; } s);
10207 if (TagDC != PrototypeTagContext)
10208 TD->setLexicalDeclContext(TagDC);
10209 }
10210 }
10211 } else if (const FunctionProtoType *FT = R->getAs<FunctionProtoType>()) {
10212 // When we're declaring a function with a typedef, typeof, etc as in the
10213 // following example, we'll need to synthesize (unnamed)
10214 // parameters for use in the declaration.
10215 //
10216 // @code
10217 // typedef void fn(int);
10218 // fn f;
10219 // @endcode
10220
10221 // Synthesize a parameter for each argument type.
10222 for (const auto &AI : FT->param_types()) {
10223 ParmVarDecl *Param =
10224 BuildParmVarDeclForTypedef(DC: NewFD, Loc: D.getIdentifierLoc(), T: AI);
10225 Param->setScopeInfo(scopeDepth: 0, parameterIndex: Params.size());
10226 Params.push_back(Elt: Param);
10227 }
10228 } else {
10229 assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 &&
10230 "Should not need args for typedef of non-prototype fn");
10231 }
10232
10233 // Finally, we know we have the right number of parameters, install them.
10234 NewFD->setParams(Params);
10235
10236 if (D.getDeclSpec().isNoreturnSpecified())
10237 NewFD->addAttr(
10238 A: C11NoReturnAttr::Create(Ctx&: Context, Range: D.getDeclSpec().getNoreturnSpecLoc()));
10239
10240 // Functions returning a variably modified type violate C99 6.7.5.2p2
10241 // because all functions have linkage.
10242 if (!NewFD->isInvalidDecl() &&
10243 NewFD->getReturnType()->isVariablyModifiedType()) {
10244 Diag(Loc: NewFD->getLocation(), DiagID: diag::err_vm_func_decl);
10245 NewFD->setInvalidDecl();
10246 }
10247
10248 // Apply an implicit SectionAttr if '#pragma clang section text' is active
10249 if (PragmaClangTextSection.Valid && D.isFunctionDefinition() &&
10250 !NewFD->hasAttr<SectionAttr>())
10251 NewFD->addAttr(A: PragmaClangTextSectionAttr::CreateImplicit(
10252 Ctx&: Context, Name: PragmaClangTextSection.SectionName,
10253 Range: PragmaClangTextSection.PragmaLocation));
10254
10255 // Apply an implicit SectionAttr if #pragma code_seg is active.
10256 if (CodeSegStack.CurrentValue && D.isFunctionDefinition() &&
10257 !NewFD->hasAttr<SectionAttr>()) {
10258 NewFD->addAttr(A: SectionAttr::CreateImplicit(
10259 Ctx&: Context, Name: CodeSegStack.CurrentValue->getString(),
10260 Range: CodeSegStack.CurrentPragmaLocation, S: SectionAttr::Declspec_allocate));
10261 if (UnifySection(SectionName: CodeSegStack.CurrentValue->getString(),
10262 SectionFlags: ASTContext::PSF_Implicit | ASTContext::PSF_Execute |
10263 ASTContext::PSF_Read,
10264 TheDecl: NewFD))
10265 NewFD->dropAttr<SectionAttr>();
10266 }
10267
10268 // Apply an implicit StrictGuardStackCheckAttr if #pragma strict_gs_check is
10269 // active.
10270 if (StrictGuardStackCheckStack.CurrentValue && D.isFunctionDefinition() &&
10271 !NewFD->hasAttr<StrictGuardStackCheckAttr>())
10272 NewFD->addAttr(A: StrictGuardStackCheckAttr::CreateImplicit(
10273 Ctx&: Context, Range: PragmaClangTextSection.PragmaLocation));
10274
10275 // Apply an implicit CodeSegAttr from class declspec or
10276 // apply an implicit SectionAttr from #pragma code_seg if active.
10277 if (!NewFD->hasAttr<CodeSegAttr>()) {
10278 if (Attr *SAttr = getImplicitCodeSegOrSectionAttrForFunction(FD: NewFD,
10279 IsDefinition: D.isFunctionDefinition())) {
10280 NewFD->addAttr(A: SAttr);
10281 }
10282 }
10283
10284 // Handle attributes.
10285 ProcessDeclAttributes(S, D: NewFD, PD: D);
10286 const auto *NewTVA = NewFD->getAttr<TargetVersionAttr>();
10287 if (NewTVA && !NewTVA->isDefaultVersion() &&
10288 !Context.getTargetInfo().hasFeature(Feature: "fmv")) {
10289 // Don't add to scope fmv functions declarations if fmv disabled
10290 AddToScope = false;
10291 return NewFD;
10292 }
10293
10294 if (getLangOpts().OpenCL || getLangOpts().HLSL) {
10295 // Neither OpenCL nor HLSL allow an address space qualifyer on a return
10296 // type.
10297 //
10298 // OpenCL v1.1 s6.5: Using an address space qualifier in a function return
10299 // type declaration will generate a compilation error.
10300 LangAS AddressSpace = NewFD->getReturnType().getAddressSpace();
10301 if (AddressSpace != LangAS::Default) {
10302 Diag(Loc: NewFD->getLocation(), DiagID: diag::err_return_value_with_address_space);
10303 NewFD->setInvalidDecl();
10304 }
10305 }
10306
10307 if (!getLangOpts().CPlusPlus) {
10308 // Perform semantic checking on the function declaration.
10309 if (!NewFD->isInvalidDecl() && NewFD->isMain())
10310 CheckMain(FD: NewFD, D: D.getDeclSpec());
10311
10312 if (!NewFD->isInvalidDecl() && NewFD->isMSVCRTEntryPoint())
10313 CheckMSVCRTEntryPoint(FD: NewFD);
10314
10315 if (!NewFD->isInvalidDecl())
10316 D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous,
10317 IsMemberSpecialization: isMemberSpecialization,
10318 DeclIsDefn: D.isFunctionDefinition()));
10319 else if (!Previous.empty())
10320 // Recover gracefully from an invalid redeclaration.
10321 D.setRedeclaration(true);
10322 assert((NewFD->isInvalidDecl() || !D.isRedeclaration() ||
10323 Previous.getResultKind() != LookupResult::FoundOverloaded) &&
10324 "previous declaration set still overloaded");
10325
10326 // Diagnose no-prototype function declarations with calling conventions that
10327 // don't support variadic calls. Only do this in C and do it after merging
10328 // possibly prototyped redeclarations.
10329 const FunctionType *FT = NewFD->getType()->castAs<FunctionType>();
10330 if (isa<FunctionNoProtoType>(Val: FT) && !D.isFunctionDefinition()) {
10331 CallingConv CC = FT->getExtInfo().getCC();
10332 if (!supportsVariadicCall(CC)) {
10333 // Windows system headers sometimes accidentally use stdcall without
10334 // (void) parameters, so we relax this to a warning.
10335 int DiagID =
10336 CC == CC_X86StdCall ? diag::warn_cconv_knr : diag::err_cconv_knr;
10337 Diag(Loc: NewFD->getLocation(), DiagID)
10338 << FunctionType::getNameForCallConv(CC);
10339 }
10340 }
10341
10342 if (NewFD->getReturnType().hasNonTrivialToPrimitiveDestructCUnion() ||
10343 NewFD->getReturnType().hasNonTrivialToPrimitiveCopyCUnion())
10344 checkNonTrivialCUnion(QT: NewFD->getReturnType(),
10345 Loc: NewFD->getReturnTypeSourceRange().getBegin(),
10346 UseContext: NTCUC_FunctionReturn, NonTrivialKind: NTCUK_Destruct|NTCUK_Copy);
10347 } else {
10348 // C++11 [replacement.functions]p3:
10349 // The program's definitions shall not be specified as inline.
10350 //
10351 // N.B. We diagnose declarations instead of definitions per LWG issue 2340.
10352 //
10353 // Suppress the diagnostic if the function is __attribute__((used)), since
10354 // that forces an external definition to be emitted.
10355 if (D.getDeclSpec().isInlineSpecified() &&
10356 NewFD->isReplaceableGlobalAllocationFunction() &&
10357 !NewFD->hasAttr<UsedAttr>())
10358 Diag(Loc: D.getDeclSpec().getInlineSpecLoc(),
10359 DiagID: diag::ext_operator_new_delete_declared_inline)
10360 << NewFD->getDeclName();
10361
10362 if (Expr *TRC = NewFD->getTrailingRequiresClause()) {
10363 // C++20 [dcl.decl.general]p4:
10364 // The optional requires-clause in an init-declarator or
10365 // member-declarator shall be present only if the declarator declares a
10366 // templated function.
10367 //
10368 // C++20 [temp.pre]p8:
10369 // An entity is templated if it is
10370 // - a template,
10371 // - an entity defined or created in a templated entity,
10372 // - a member of a templated entity,
10373 // - an enumerator for an enumeration that is a templated entity, or
10374 // - the closure type of a lambda-expression appearing in the
10375 // declaration of a templated entity.
10376 //
10377 // [Note 6: A local class, a local or block variable, or a friend
10378 // function defined in a templated entity is a templated entity.
10379 // — end note]
10380 //
10381 // A templated function is a function template or a function that is
10382 // templated. A templated class is a class template or a class that is
10383 // templated. A templated variable is a variable template or a variable
10384 // that is templated.
10385 if (!FunctionTemplate) {
10386 if (isFunctionTemplateSpecialization || isMemberSpecialization) {
10387 // C++ [temp.expl.spec]p8 (proposed resolution for CWG2847):
10388 // An explicit specialization shall not have a trailing
10389 // requires-clause unless it declares a function template.
10390 //
10391 // Since a friend function template specialization cannot be
10392 // definition, and since a non-template friend declaration with a
10393 // trailing requires-clause must be a definition, we diagnose
10394 // friend function template specializations with trailing
10395 // requires-clauses on the same path as explicit specializations
10396 // even though they aren't necessarily prohibited by the same
10397 // language rule.
10398 Diag(Loc: TRC->getBeginLoc(), DiagID: diag::err_non_temp_spec_requires_clause)
10399 << isFriend;
10400 } else if (isFriend && NewFD->isTemplated() &&
10401 !D.isFunctionDefinition()) {
10402 // C++ [temp.friend]p9:
10403 // A non-template friend declaration with a requires-clause shall be
10404 // a definition.
10405 Diag(Loc: NewFD->getBeginLoc(),
10406 DiagID: diag::err_non_temp_friend_decl_with_requires_clause_must_be_def);
10407 NewFD->setInvalidDecl();
10408 } else if (!NewFD->isTemplated() ||
10409 !(isa<CXXMethodDecl>(Val: NewFD) || D.isFunctionDefinition())) {
10410 Diag(Loc: TRC->getBeginLoc(),
10411 DiagID: diag::err_constrained_non_templated_function);
10412 }
10413 }
10414 }
10415
10416 // We do not add HD attributes to specializations here because
10417 // they may have different constexpr-ness compared to their
10418 // templates and, after maybeAddHostDeviceAttrs() is applied,
10419 // may end up with different effective targets. Instead, a
10420 // specialization inherits its target attributes from its template
10421 // in the CheckFunctionTemplateSpecialization() call below.
10422 if (getLangOpts().CUDA && !isFunctionTemplateSpecialization)
10423 CUDA().maybeAddHostDeviceAttrs(FD: NewFD, Previous);
10424
10425 // Handle explicit specializations of function templates
10426 // and friend function declarations with an explicit
10427 // template argument list.
10428 if (isFunctionTemplateSpecialization) {
10429 bool isDependentSpecialization = false;
10430 if (isFriend) {
10431 // For friend function specializations, this is a dependent
10432 // specialization if its semantic context is dependent, its
10433 // type is dependent, or if its template-id is dependent.
10434 isDependentSpecialization =
10435 DC->isDependentContext() || NewFD->getType()->isDependentType() ||
10436 (HasExplicitTemplateArgs &&
10437 TemplateSpecializationType::
10438 anyInstantiationDependentTemplateArguments(
10439 Args: TemplateArgs.arguments()));
10440 assert((!isDependentSpecialization ||
10441 (HasExplicitTemplateArgs == isDependentSpecialization)) &&
10442 "dependent friend function specialization without template "
10443 "args");
10444 } else {
10445 // For class-scope explicit specializations of function templates,
10446 // if the lexical context is dependent, then the specialization
10447 // is dependent.
10448 isDependentSpecialization =
10449 CurContext->isRecord() && CurContext->isDependentContext();
10450 }
10451
10452 TemplateArgumentListInfo *ExplicitTemplateArgs =
10453 HasExplicitTemplateArgs ? &TemplateArgs : nullptr;
10454 if (isDependentSpecialization) {
10455 // If it's a dependent specialization, it may not be possible
10456 // to determine the primary template (for explicit specializations)
10457 // or befriended declaration (for friends) until the enclosing
10458 // template is instantiated. In such cases, we store the declarations
10459 // found by name lookup and defer resolution until instantiation.
10460 if (CheckDependentFunctionTemplateSpecialization(
10461 FD: NewFD, ExplicitTemplateArgs, Previous))
10462 NewFD->setInvalidDecl();
10463 } else if (!NewFD->isInvalidDecl()) {
10464 if (CheckFunctionTemplateSpecialization(FD: NewFD, ExplicitTemplateArgs,
10465 Previous))
10466 NewFD->setInvalidDecl();
10467 }
10468 } else if (isMemberSpecialization && isa<CXXMethodDecl>(Val: NewFD)) {
10469 if (CheckMemberSpecialization(Member: NewFD, Previous))
10470 NewFD->setInvalidDecl();
10471 }
10472
10473 // Perform semantic checking on the function declaration.
10474 if (!NewFD->isInvalidDecl() && NewFD->isMain())
10475 CheckMain(FD: NewFD, D: D.getDeclSpec());
10476
10477 if (!NewFD->isInvalidDecl() && NewFD->isMSVCRTEntryPoint())
10478 CheckMSVCRTEntryPoint(FD: NewFD);
10479
10480 if (!NewFD->isInvalidDecl())
10481 D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous,
10482 IsMemberSpecialization: isMemberSpecialization,
10483 DeclIsDefn: D.isFunctionDefinition()));
10484 else if (!Previous.empty())
10485 // Recover gracefully from an invalid redeclaration.
10486 D.setRedeclaration(true);
10487
10488 assert((NewFD->isInvalidDecl() || NewFD->isMultiVersion() ||
10489 !D.isRedeclaration() ||
10490 Previous.getResultKind() != LookupResult::FoundOverloaded) &&
10491 "previous declaration set still overloaded");
10492
10493 NamedDecl *PrincipalDecl = (FunctionTemplate
10494 ? cast<NamedDecl>(Val: FunctionTemplate)
10495 : NewFD);
10496
10497 if (isFriend && NewFD->getPreviousDecl()) {
10498 AccessSpecifier Access = AS_public;
10499 if (!NewFD->isInvalidDecl())
10500 Access = NewFD->getPreviousDecl()->getAccess();
10501
10502 NewFD->setAccess(Access);
10503 if (FunctionTemplate) FunctionTemplate->setAccess(Access);
10504 }
10505
10506 if (NewFD->isOverloadedOperator() && !DC->isRecord() &&
10507 PrincipalDecl->isInIdentifierNamespace(NS: Decl::IDNS_Ordinary))
10508 PrincipalDecl->setNonMemberOperator();
10509
10510 // If we have a function template, check the template parameter
10511 // list. This will check and merge default template arguments.
10512 if (FunctionTemplate) {
10513 FunctionTemplateDecl *PrevTemplate =
10514 FunctionTemplate->getPreviousDecl();
10515 CheckTemplateParameterList(NewParams: FunctionTemplate->getTemplateParameters(),
10516 OldParams: PrevTemplate ? PrevTemplate->getTemplateParameters()
10517 : nullptr,
10518 TPC: D.getDeclSpec().isFriendSpecified()
10519 ? (D.isFunctionDefinition()
10520 ? TPC_FriendFunctionTemplateDefinition
10521 : TPC_FriendFunctionTemplate)
10522 : (D.getCXXScopeSpec().isSet() &&
10523 DC && DC->isRecord() &&
10524 DC->isDependentContext())
10525 ? TPC_ClassTemplateMember
10526 : TPC_FunctionTemplate);
10527 }
10528
10529 if (NewFD->isInvalidDecl()) {
10530 // Ignore all the rest of this.
10531 } else if (!D.isRedeclaration()) {
10532 struct ActOnFDArgs ExtraArgs = { .S: S, .D: D, .TemplateParamLists: TemplateParamLists,
10533 .AddToScope: AddToScope };
10534 // Fake up an access specifier if it's supposed to be a class member.
10535 if (isa<CXXRecordDecl>(Val: NewFD->getDeclContext()))
10536 NewFD->setAccess(AS_public);
10537
10538 // Qualified decls generally require a previous declaration.
10539 if (D.getCXXScopeSpec().isSet()) {
10540 // ...with the major exception of templated-scope or
10541 // dependent-scope friend declarations.
10542
10543 // TODO: we currently also suppress this check in dependent
10544 // contexts because (1) the parameter depth will be off when
10545 // matching friend templates and (2) we might actually be
10546 // selecting a friend based on a dependent factor. But there
10547 // are situations where these conditions don't apply and we
10548 // can actually do this check immediately.
10549 //
10550 // Unless the scope is dependent, it's always an error if qualified
10551 // redeclaration lookup found nothing at all. Diagnose that now;
10552 // nothing will diagnose that error later.
10553 if (isFriend &&
10554 (D.getCXXScopeSpec().getScopeRep()->isDependent() ||
10555 (!Previous.empty() && CurContext->isDependentContext()))) {
10556 // ignore these
10557 } else if (NewFD->isCPUDispatchMultiVersion() ||
10558 NewFD->isCPUSpecificMultiVersion()) {
10559 // ignore this, we allow the redeclaration behavior here to create new
10560 // versions of the function.
10561 } else {
10562 // The user tried to provide an out-of-line definition for a
10563 // function that is a member of a class or namespace, but there
10564 // was no such member function declared (C++ [class.mfct]p2,
10565 // C++ [namespace.memdef]p2). For example:
10566 //
10567 // class X {
10568 // void f() const;
10569 // };
10570 //
10571 // void X::f() { } // ill-formed
10572 //
10573 // Complain about this problem, and attempt to suggest close
10574 // matches (e.g., those that differ only in cv-qualifiers and
10575 // whether the parameter types are references).
10576
10577 if (NamedDecl *Result = DiagnoseInvalidRedeclaration(
10578 SemaRef&: *this, Previous, NewFD, ExtraArgs, IsLocalFriend: false, S: nullptr)) {
10579 AddToScope = ExtraArgs.AddToScope;
10580 return Result;
10581 }
10582 }
10583
10584 // Unqualified local friend declarations are required to resolve
10585 // to something.
10586 } else if (isFriend && cast<CXXRecordDecl>(Val: CurContext)->isLocalClass()) {
10587 if (NamedDecl *Result = DiagnoseInvalidRedeclaration(
10588 SemaRef&: *this, Previous, NewFD, ExtraArgs, IsLocalFriend: true, S)) {
10589 AddToScope = ExtraArgs.AddToScope;
10590 return Result;
10591 }
10592 }
10593 } else if (!D.isFunctionDefinition() &&
10594 isa<CXXMethodDecl>(Val: NewFD) && NewFD->isOutOfLine() &&
10595 !isFriend && !isFunctionTemplateSpecialization &&
10596 !isMemberSpecialization) {
10597 // An out-of-line member function declaration must also be a
10598 // definition (C++ [class.mfct]p2).
10599 // Note that this is not the case for explicit specializations of
10600 // function templates or member functions of class templates, per
10601 // C++ [temp.expl.spec]p2. We also allow these declarations as an
10602 // extension for compatibility with old SWIG code which likes to
10603 // generate them.
10604 Diag(Loc: NewFD->getLocation(), DiagID: diag::ext_out_of_line_declaration)
10605 << D.getCXXScopeSpec().getRange();
10606 }
10607 }
10608
10609 if (getLangOpts().HLSL && D.isFunctionDefinition()) {
10610 // Any top level function could potentially be specified as an entry.
10611 if (!NewFD->isInvalidDecl() && S->getDepth() == 0 && Name.isIdentifier())
10612 HLSL().ActOnTopLevelFunction(FD: NewFD);
10613
10614 if (NewFD->hasAttr<HLSLShaderAttr>())
10615 HLSL().CheckEntryPoint(FD: NewFD);
10616 }
10617
10618 // If this is the first declaration of a library builtin function, add
10619 // attributes as appropriate.
10620 if (!D.isRedeclaration()) {
10621 if (IdentifierInfo *II = Previous.getLookupName().getAsIdentifierInfo()) {
10622 if (unsigned BuiltinID = II->getBuiltinID()) {
10623 bool InStdNamespace = Context.BuiltinInfo.isInStdNamespace(ID: BuiltinID);
10624 if (!InStdNamespace &&
10625 NewFD->getDeclContext()->getRedeclContext()->isFileContext()) {
10626 if (NewFD->getLanguageLinkage() == CLanguageLinkage) {
10627 // Validate the type matches unless this builtin is specified as
10628 // matching regardless of its declared type.
10629 if (Context.BuiltinInfo.allowTypeMismatch(ID: BuiltinID)) {
10630 NewFD->addAttr(A: BuiltinAttr::CreateImplicit(Ctx&: Context, ID: BuiltinID));
10631 } else {
10632 ASTContext::GetBuiltinTypeError Error;
10633 LookupNecessaryTypesForBuiltin(S, ID: BuiltinID);
10634 QualType BuiltinType = Context.GetBuiltinType(ID: BuiltinID, Error);
10635
10636 if (!Error && !BuiltinType.isNull() &&
10637 Context.hasSameFunctionTypeIgnoringExceptionSpec(
10638 T: NewFD->getType(), U: BuiltinType))
10639 NewFD->addAttr(A: BuiltinAttr::CreateImplicit(Ctx&: Context, ID: BuiltinID));
10640 }
10641 }
10642 } else if (InStdNamespace && NewFD->isInStdNamespace() &&
10643 isStdBuiltin(Ctx&: Context, FD: NewFD, BuiltinID)) {
10644 NewFD->addAttr(A: BuiltinAttr::CreateImplicit(Ctx&: Context, ID: BuiltinID));
10645 }
10646 }
10647 }
10648 }
10649
10650 ProcessPragmaWeak(S, D: NewFD);
10651 checkAttributesAfterMerging(S&: *this, ND&: *NewFD);
10652
10653 AddKnownFunctionAttributes(FD: NewFD);
10654
10655 if (NewFD->hasAttr<OverloadableAttr>() &&
10656 !NewFD->getType()->getAs<FunctionProtoType>()) {
10657 Diag(Loc: NewFD->getLocation(),
10658 DiagID: diag::err_attribute_overloadable_no_prototype)
10659 << NewFD;
10660 NewFD->dropAttr<OverloadableAttr>();
10661 }
10662
10663 // If there's a #pragma GCC visibility in scope, and this isn't a class
10664 // member, set the visibility of this function.
10665 if (!DC->isRecord() && NewFD->isExternallyVisible())
10666 AddPushedVisibilityAttribute(RD: NewFD);
10667
10668 // If there's a #pragma clang arc_cf_code_audited in scope, consider
10669 // marking the function.
10670 ObjC().AddCFAuditedAttribute(D: NewFD);
10671
10672 // If this is a function definition, check if we have to apply any
10673 // attributes (i.e. optnone and no_builtin) due to a pragma.
10674 if (D.isFunctionDefinition()) {
10675 AddRangeBasedOptnone(FD: NewFD);
10676 AddImplicitMSFunctionNoBuiltinAttr(FD: NewFD);
10677 AddSectionMSAllocText(FD: NewFD);
10678 ModifyFnAttributesMSPragmaOptimize(FD: NewFD);
10679 }
10680
10681 // If this is the first declaration of an extern C variable, update
10682 // the map of such variables.
10683 if (NewFD->isFirstDecl() && !NewFD->isInvalidDecl() &&
10684 isIncompleteDeclExternC(S&: *this, D: NewFD))
10685 RegisterLocallyScopedExternCDecl(ND: NewFD, S);
10686
10687 // Set this FunctionDecl's range up to the right paren.
10688 NewFD->setRangeEnd(D.getSourceRange().getEnd());
10689
10690 if (D.isRedeclaration() && !Previous.empty()) {
10691 NamedDecl *Prev = Previous.getRepresentativeDecl();
10692 checkDLLAttributeRedeclaration(S&: *this, OldDecl: Prev, NewDecl: NewFD,
10693 IsSpecialization: isMemberSpecialization ||
10694 isFunctionTemplateSpecialization,
10695 IsDefinition: D.isFunctionDefinition());
10696 }
10697
10698 if (getLangOpts().CUDA) {
10699 IdentifierInfo *II = NewFD->getIdentifier();
10700 if (II && II->isStr(Str: CUDA().getConfigureFuncName()) &&
10701 !NewFD->isInvalidDecl() &&
10702 NewFD->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
10703 if (!R->castAs<FunctionType>()->getReturnType()->isScalarType())
10704 Diag(Loc: NewFD->getLocation(), DiagID: diag::err_config_scalar_return)
10705 << CUDA().getConfigureFuncName();
10706 Context.setcudaConfigureCallDecl(NewFD);
10707 }
10708
10709 // Variadic functions, other than a *declaration* of printf, are not allowed
10710 // in device-side CUDA code, unless someone passed
10711 // -fcuda-allow-variadic-functions.
10712 if (!getLangOpts().CUDAAllowVariadicFunctions && NewFD->isVariadic() &&
10713 (NewFD->hasAttr<CUDADeviceAttr>() ||
10714 NewFD->hasAttr<CUDAGlobalAttr>()) &&
10715 !(II && II->isStr(Str: "printf") && NewFD->isExternC() &&
10716 !D.isFunctionDefinition())) {
10717 Diag(Loc: NewFD->getLocation(), DiagID: diag::err_variadic_device_fn);
10718 }
10719 }
10720
10721 MarkUnusedFileScopedDecl(D: NewFD);
10722
10723
10724
10725 if (getLangOpts().OpenCL && NewFD->hasAttr<OpenCLKernelAttr>()) {
10726 // OpenCL v1.2 s6.8 static is invalid for kernel functions.
10727 if (SC == SC_Static) {
10728 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_static_kernel);
10729 D.setInvalidType();
10730 }
10731
10732 // OpenCL v1.2, s6.9 -- Kernels can only have return type void.
10733 if (!NewFD->getReturnType()->isVoidType()) {
10734 SourceRange RTRange = NewFD->getReturnTypeSourceRange();
10735 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_expected_kernel_void_return_type)
10736 << (RTRange.isValid() ? FixItHint::CreateReplacement(RemoveRange: RTRange, Code: "void")
10737 : FixItHint());
10738 D.setInvalidType();
10739 }
10740
10741 llvm::SmallPtrSet<const Type *, 16> ValidTypes;
10742 for (auto *Param : NewFD->parameters())
10743 checkIsValidOpenCLKernelParameter(S&: *this, D, Param, ValidTypes);
10744
10745 if (getLangOpts().OpenCLCPlusPlus) {
10746 if (DC->isRecord()) {
10747 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_method_kernel);
10748 D.setInvalidType();
10749 }
10750 if (FunctionTemplate) {
10751 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_template_kernel);
10752 D.setInvalidType();
10753 }
10754 }
10755 }
10756
10757 if (getLangOpts().CPlusPlus) {
10758 // Precalculate whether this is a friend function template with a constraint
10759 // that depends on an enclosing template, per [temp.friend]p9.
10760 if (isFriend && FunctionTemplate &&
10761 FriendConstraintsDependOnEnclosingTemplate(FD: NewFD)) {
10762 NewFD->setFriendConstraintRefersToEnclosingTemplate(true);
10763
10764 // C++ [temp.friend]p9:
10765 // A friend function template with a constraint that depends on a
10766 // template parameter from an enclosing template shall be a definition.
10767 if (!D.isFunctionDefinition()) {
10768 Diag(Loc: NewFD->getBeginLoc(),
10769 DiagID: diag::err_friend_decl_with_enclosing_temp_constraint_must_be_def);
10770 NewFD->setInvalidDecl();
10771 }
10772 }
10773
10774 if (FunctionTemplate) {
10775 if (NewFD->isInvalidDecl())
10776 FunctionTemplate->setInvalidDecl();
10777 return FunctionTemplate;
10778 }
10779
10780 if (isMemberSpecialization && !NewFD->isInvalidDecl())
10781 CompleteMemberSpecialization(Member: NewFD, Previous);
10782 }
10783
10784 for (const ParmVarDecl *Param : NewFD->parameters()) {
10785 QualType PT = Param->getType();
10786
10787 // OpenCL 2.0 pipe restrictions forbids pipe packet types to be non-value
10788 // types.
10789 if (getLangOpts().getOpenCLCompatibleVersion() >= 200) {
10790 if(const PipeType *PipeTy = PT->getAs<PipeType>()) {
10791 QualType ElemTy = PipeTy->getElementType();
10792 if (ElemTy->isReferenceType() || ElemTy->isPointerType()) {
10793 Diag(Loc: Param->getTypeSpecStartLoc(), DiagID: diag::err_reference_pipe_type );
10794 D.setInvalidType();
10795 }
10796 }
10797 }
10798 // WebAssembly tables can't be used as function parameters.
10799 if (Context.getTargetInfo().getTriple().isWasm()) {
10800 if (PT->getUnqualifiedDesugaredType()->isWebAssemblyTableType()) {
10801 Diag(Loc: Param->getTypeSpecStartLoc(),
10802 DiagID: diag::err_wasm_table_as_function_parameter);
10803 D.setInvalidType();
10804 }
10805 }
10806 }
10807
10808 // Diagnose availability attributes. Availability cannot be used on functions
10809 // that are run during load/unload.
10810 if (const auto *attr = NewFD->getAttr<AvailabilityAttr>()) {
10811 if (NewFD->hasAttr<ConstructorAttr>()) {
10812 Diag(Loc: attr->getLocation(), DiagID: diag::warn_availability_on_static_initializer)
10813 << 1;
10814 NewFD->dropAttr<AvailabilityAttr>();
10815 }
10816 if (NewFD->hasAttr<DestructorAttr>()) {
10817 Diag(Loc: attr->getLocation(), DiagID: diag::warn_availability_on_static_initializer)
10818 << 2;
10819 NewFD->dropAttr<AvailabilityAttr>();
10820 }
10821 }
10822
10823 // Diagnose no_builtin attribute on function declaration that are not a
10824 // definition.
10825 // FIXME: We should really be doing this in
10826 // SemaDeclAttr.cpp::handleNoBuiltinAttr, unfortunately we only have access to
10827 // the FunctionDecl and at this point of the code
10828 // FunctionDecl::isThisDeclarationADefinition() which always returns `false`
10829 // because Sema::ActOnStartOfFunctionDef has not been called yet.
10830 if (const auto *NBA = NewFD->getAttr<NoBuiltinAttr>())
10831 switch (D.getFunctionDefinitionKind()) {
10832 case FunctionDefinitionKind::Defaulted:
10833 case FunctionDefinitionKind::Deleted:
10834 Diag(Loc: NBA->getLocation(),
10835 DiagID: diag::err_attribute_no_builtin_on_defaulted_deleted_function)
10836 << NBA->getSpelling();
10837 break;
10838 case FunctionDefinitionKind::Declaration:
10839 Diag(Loc: NBA->getLocation(), DiagID: diag::err_attribute_no_builtin_on_non_definition)
10840 << NBA->getSpelling();
10841 break;
10842 case FunctionDefinitionKind::Definition:
10843 break;
10844 }
10845
10846 // Similar to no_builtin logic above, at this point of the code
10847 // FunctionDecl::isThisDeclarationADefinition() always returns `false`
10848 // because Sema::ActOnStartOfFunctionDef has not been called yet.
10849 if (Context.getTargetInfo().allowDebugInfoForExternalRef() &&
10850 !NewFD->isInvalidDecl() &&
10851 D.getFunctionDefinitionKind() == FunctionDefinitionKind::Declaration)
10852 ExternalDeclarations.push_back(Elt: NewFD);
10853
10854 return NewFD;
10855}
10856
10857/// Return a CodeSegAttr from a containing class. The Microsoft docs say
10858/// when __declspec(code_seg) "is applied to a class, all member functions of
10859/// the class and nested classes -- this includes compiler-generated special
10860/// member functions -- are put in the specified segment."
10861/// The actual behavior is a little more complicated. The Microsoft compiler
10862/// won't check outer classes if there is an active value from #pragma code_seg.
10863/// The CodeSeg is always applied from the direct parent but only from outer
10864/// classes when the #pragma code_seg stack is empty. See:
10865/// https://reviews.llvm.org/D22931, the Microsoft feedback page is no longer
10866/// available since MS has removed the page.
10867static Attr *getImplicitCodeSegAttrFromClass(Sema &S, const FunctionDecl *FD) {
10868 const auto *Method = dyn_cast<CXXMethodDecl>(Val: FD);
10869 if (!Method)
10870 return nullptr;
10871 const CXXRecordDecl *Parent = Method->getParent();
10872 if (const auto *SAttr = Parent->getAttr<CodeSegAttr>()) {
10873 Attr *NewAttr = SAttr->clone(C&: S.getASTContext());
10874 NewAttr->setImplicit(true);
10875 return NewAttr;
10876 }
10877
10878 // The Microsoft compiler won't check outer classes for the CodeSeg
10879 // when the #pragma code_seg stack is active.
10880 if (S.CodeSegStack.CurrentValue)
10881 return nullptr;
10882
10883 while ((Parent = dyn_cast<CXXRecordDecl>(Val: Parent->getParent()))) {
10884 if (const auto *SAttr = Parent->getAttr<CodeSegAttr>()) {
10885 Attr *NewAttr = SAttr->clone(C&: S.getASTContext());
10886 NewAttr->setImplicit(true);
10887 return NewAttr;
10888 }
10889 }
10890 return nullptr;
10891}
10892
10893Attr *Sema::getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
10894 bool IsDefinition) {
10895 if (Attr *A = getImplicitCodeSegAttrFromClass(S&: *this, FD))
10896 return A;
10897 if (!FD->hasAttr<SectionAttr>() && IsDefinition &&
10898 CodeSegStack.CurrentValue)
10899 return SectionAttr::CreateImplicit(
10900 Ctx&: getASTContext(), Name: CodeSegStack.CurrentValue->getString(),
10901 Range: CodeSegStack.CurrentPragmaLocation, S: SectionAttr::Declspec_allocate);
10902 return nullptr;
10903}
10904
10905bool Sema::canFullyTypeCheckRedeclaration(ValueDecl *NewD, ValueDecl *OldD,
10906 QualType NewT, QualType OldT) {
10907 if (!NewD->getLexicalDeclContext()->isDependentContext())
10908 return true;
10909
10910 // For dependently-typed local extern declarations and friends, we can't
10911 // perform a correct type check in general until instantiation:
10912 //
10913 // int f();
10914 // template<typename T> void g() { T f(); }
10915 //
10916 // (valid if g() is only instantiated with T = int).
10917 if (NewT->isDependentType() &&
10918 (NewD->isLocalExternDecl() || NewD->getFriendObjectKind()))
10919 return false;
10920
10921 // Similarly, if the previous declaration was a dependent local extern
10922 // declaration, we don't really know its type yet.
10923 if (OldT->isDependentType() && OldD->isLocalExternDecl())
10924 return false;
10925
10926 return true;
10927}
10928
10929bool Sema::shouldLinkDependentDeclWithPrevious(Decl *D, Decl *PrevDecl) {
10930 if (!D->getLexicalDeclContext()->isDependentContext())
10931 return true;
10932
10933 // Don't chain dependent friend function definitions until instantiation, to
10934 // permit cases like
10935 //
10936 // void func();
10937 // template<typename T> class C1 { friend void func() {} };
10938 // template<typename T> class C2 { friend void func() {} };
10939 //
10940 // ... which is valid if only one of C1 and C2 is ever instantiated.
10941 //
10942 // FIXME: This need only apply to function definitions. For now, we proxy
10943 // this by checking for a file-scope function. We do not want this to apply
10944 // to friend declarations nominating member functions, because that gets in
10945 // the way of access checks.
10946 if (D->getFriendObjectKind() && D->getDeclContext()->isFileContext())
10947 return false;
10948
10949 auto *VD = dyn_cast<ValueDecl>(Val: D);
10950 auto *PrevVD = dyn_cast<ValueDecl>(Val: PrevDecl);
10951 return !VD || !PrevVD ||
10952 canFullyTypeCheckRedeclaration(NewD: VD, OldD: PrevVD, NewT: VD->getType(),
10953 OldT: PrevVD->getType());
10954}
10955
10956/// Check the target or target_version attribute of the function for
10957/// MultiVersion validity.
10958///
10959/// Returns true if there was an error, false otherwise.
10960static bool CheckMultiVersionValue(Sema &S, const FunctionDecl *FD) {
10961 const auto *TA = FD->getAttr<TargetAttr>();
10962 const auto *TVA = FD->getAttr<TargetVersionAttr>();
10963 assert(
10964 (TA || TVA) &&
10965 "MultiVersion candidate requires a target or target_version attribute");
10966 const TargetInfo &TargetInfo = S.Context.getTargetInfo();
10967 enum ErrType { Feature = 0, Architecture = 1 };
10968
10969 if (TA) {
10970 ParsedTargetAttr ParseInfo =
10971 S.getASTContext().getTargetInfo().parseTargetAttr(Str: TA->getFeaturesStr());
10972 if (!ParseInfo.CPU.empty() && !TargetInfo.validateCpuIs(Name: ParseInfo.CPU)) {
10973 S.Diag(Loc: FD->getLocation(), DiagID: diag::err_bad_multiversion_option)
10974 << Architecture << ParseInfo.CPU;
10975 return true;
10976 }
10977 for (const auto &Feat : ParseInfo.Features) {
10978 auto BareFeat = StringRef{Feat}.substr(Start: 1);
10979 if (Feat[0] == '-') {
10980 S.Diag(Loc: FD->getLocation(), DiagID: diag::err_bad_multiversion_option)
10981 << Feature << ("no-" + BareFeat).str();
10982 return true;
10983 }
10984
10985 if (!TargetInfo.validateCpuSupports(Name: BareFeat) ||
10986 !TargetInfo.isValidFeatureName(Feature: BareFeat)) {
10987 S.Diag(Loc: FD->getLocation(), DiagID: diag::err_bad_multiversion_option)
10988 << Feature << BareFeat;
10989 return true;
10990 }
10991 }
10992 }
10993
10994 if (TVA) {
10995 llvm::SmallVector<StringRef, 8> Feats;
10996 TVA->getFeatures(Out&: Feats);
10997 for (const auto &Feat : Feats) {
10998 if (!TargetInfo.validateCpuSupports(Name: Feat)) {
10999 S.Diag(Loc: FD->getLocation(), DiagID: diag::err_bad_multiversion_option)
11000 << Feature << Feat;
11001 return true;
11002 }
11003 }
11004 }
11005 return false;
11006}
11007
11008// Provide a white-list of attributes that are allowed to be combined with
11009// multiversion functions.
11010static bool AttrCompatibleWithMultiVersion(attr::Kind Kind,
11011 MultiVersionKind MVKind) {
11012 // Note: this list/diagnosis must match the list in
11013 // checkMultiversionAttributesAllSame.
11014 switch (Kind) {
11015 default:
11016 return false;
11017 case attr::ArmLocallyStreaming:
11018 return MVKind == MultiVersionKind::TargetVersion ||
11019 MVKind == MultiVersionKind::TargetClones;
11020 case attr::Used:
11021 return MVKind == MultiVersionKind::Target;
11022 case attr::NonNull:
11023 case attr::NoThrow:
11024 return true;
11025 }
11026}
11027
11028static bool checkNonMultiVersionCompatAttributes(Sema &S,
11029 const FunctionDecl *FD,
11030 const FunctionDecl *CausedFD,
11031 MultiVersionKind MVKind) {
11032 const auto Diagnose = [FD, CausedFD, MVKind](Sema &S, const Attr *A) {
11033 S.Diag(Loc: FD->getLocation(), DiagID: diag::err_multiversion_disallowed_other_attr)
11034 << static_cast<unsigned>(MVKind) << A;
11035 if (CausedFD)
11036 S.Diag(Loc: CausedFD->getLocation(), DiagID: diag::note_multiversioning_caused_here);
11037 return true;
11038 };
11039
11040 for (const Attr *A : FD->attrs()) {
11041 switch (A->getKind()) {
11042 case attr::CPUDispatch:
11043 case attr::CPUSpecific:
11044 if (MVKind != MultiVersionKind::CPUDispatch &&
11045 MVKind != MultiVersionKind::CPUSpecific)
11046 return Diagnose(S, A);
11047 break;
11048 case attr::Target:
11049 if (MVKind != MultiVersionKind::Target)
11050 return Diagnose(S, A);
11051 break;
11052 case attr::TargetVersion:
11053 if (MVKind != MultiVersionKind::TargetVersion &&
11054 MVKind != MultiVersionKind::TargetClones)
11055 return Diagnose(S, A);
11056 break;
11057 case attr::TargetClones:
11058 if (MVKind != MultiVersionKind::TargetClones &&
11059 MVKind != MultiVersionKind::TargetVersion)
11060 return Diagnose(S, A);
11061 break;
11062 default:
11063 if (!AttrCompatibleWithMultiVersion(Kind: A->getKind(), MVKind))
11064 return Diagnose(S, A);
11065 break;
11066 }
11067 }
11068 return false;
11069}
11070
11071bool Sema::areMultiversionVariantFunctionsCompatible(
11072 const FunctionDecl *OldFD, const FunctionDecl *NewFD,
11073 const PartialDiagnostic &NoProtoDiagID,
11074 const PartialDiagnosticAt &NoteCausedDiagIDAt,
11075 const PartialDiagnosticAt &NoSupportDiagIDAt,
11076 const PartialDiagnosticAt &DiffDiagIDAt, bool TemplatesSupported,
11077 bool ConstexprSupported, bool CLinkageMayDiffer) {
11078 enum DoesntSupport {
11079 FuncTemplates = 0,
11080 VirtFuncs = 1,
11081 DeducedReturn = 2,
11082 Constructors = 3,
11083 Destructors = 4,
11084 DeletedFuncs = 5,
11085 DefaultedFuncs = 6,
11086 ConstexprFuncs = 7,
11087 ConstevalFuncs = 8,
11088 Lambda = 9,
11089 };
11090 enum Different {
11091 CallingConv = 0,
11092 ReturnType = 1,
11093 ConstexprSpec = 2,
11094 InlineSpec = 3,
11095 Linkage = 4,
11096 LanguageLinkage = 5,
11097 };
11098
11099 if (NoProtoDiagID.getDiagID() != 0 && OldFD &&
11100 !OldFD->getType()->getAs<FunctionProtoType>()) {
11101 Diag(Loc: OldFD->getLocation(), PD: NoProtoDiagID);
11102 Diag(Loc: NoteCausedDiagIDAt.first, PD: NoteCausedDiagIDAt.second);
11103 return true;
11104 }
11105
11106 if (NoProtoDiagID.getDiagID() != 0 &&
11107 !NewFD->getType()->getAs<FunctionProtoType>())
11108 return Diag(Loc: NewFD->getLocation(), PD: NoProtoDiagID);
11109
11110 if (!TemplatesSupported &&
11111 NewFD->getTemplatedKind() == FunctionDecl::TK_FunctionTemplate)
11112 return Diag(Loc: NoSupportDiagIDAt.first, PD: NoSupportDiagIDAt.second)
11113 << FuncTemplates;
11114
11115 if (const auto *NewCXXFD = dyn_cast<CXXMethodDecl>(Val: NewFD)) {
11116 if (NewCXXFD->isVirtual())
11117 return Diag(Loc: NoSupportDiagIDAt.first, PD: NoSupportDiagIDAt.second)
11118 << VirtFuncs;
11119
11120 if (isa<CXXConstructorDecl>(Val: NewCXXFD))
11121 return Diag(Loc: NoSupportDiagIDAt.first, PD: NoSupportDiagIDAt.second)
11122 << Constructors;
11123
11124 if (isa<CXXDestructorDecl>(Val: NewCXXFD))
11125 return Diag(Loc: NoSupportDiagIDAt.first, PD: NoSupportDiagIDAt.second)
11126 << Destructors;
11127 }
11128
11129 if (NewFD->isDeleted())
11130 return Diag(Loc: NoSupportDiagIDAt.first, PD: NoSupportDiagIDAt.second)
11131 << DeletedFuncs;
11132
11133 if (NewFD->isDefaulted())
11134 return Diag(Loc: NoSupportDiagIDAt.first, PD: NoSupportDiagIDAt.second)
11135 << DefaultedFuncs;
11136
11137 if (!ConstexprSupported && NewFD->isConstexpr())
11138 return Diag(Loc: NoSupportDiagIDAt.first, PD: NoSupportDiagIDAt.second)
11139 << (NewFD->isConsteval() ? ConstevalFuncs : ConstexprFuncs);
11140
11141 QualType NewQType = Context.getCanonicalType(T: NewFD->getType());
11142 const auto *NewType = cast<FunctionType>(Val&: NewQType);
11143 QualType NewReturnType = NewType->getReturnType();
11144
11145 if (NewReturnType->isUndeducedType())
11146 return Diag(Loc: NoSupportDiagIDAt.first, PD: NoSupportDiagIDAt.second)
11147 << DeducedReturn;
11148
11149 // Ensure the return type is identical.
11150 if (OldFD) {
11151 QualType OldQType = Context.getCanonicalType(T: OldFD->getType());
11152 const auto *OldType = cast<FunctionType>(Val&: OldQType);
11153 FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo();
11154 FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo();
11155
11156 const auto *OldFPT = OldFD->getType()->getAs<FunctionProtoType>();
11157 const auto *NewFPT = NewFD->getType()->getAs<FunctionProtoType>();
11158
11159 bool ArmStreamingCCMismatched = false;
11160 if (OldFPT && NewFPT) {
11161 unsigned Diff =
11162 OldFPT->getAArch64SMEAttributes() ^ NewFPT->getAArch64SMEAttributes();
11163 // Arm-streaming, arm-streaming-compatible and non-streaming versions
11164 // cannot be mixed.
11165 if (Diff & (FunctionType::SME_PStateSMEnabledMask |
11166 FunctionType::SME_PStateSMCompatibleMask))
11167 ArmStreamingCCMismatched = true;
11168 }
11169
11170 if (OldTypeInfo.getCC() != NewTypeInfo.getCC() || ArmStreamingCCMismatched)
11171 return Diag(Loc: DiffDiagIDAt.first, PD: DiffDiagIDAt.second) << CallingConv;
11172
11173 QualType OldReturnType = OldType->getReturnType();
11174
11175 if (OldReturnType != NewReturnType)
11176 return Diag(Loc: DiffDiagIDAt.first, PD: DiffDiagIDAt.second) << ReturnType;
11177
11178 if (OldFD->getConstexprKind() != NewFD->getConstexprKind())
11179 return Diag(Loc: DiffDiagIDAt.first, PD: DiffDiagIDAt.second) << ConstexprSpec;
11180
11181 if (OldFD->isInlineSpecified() != NewFD->isInlineSpecified())
11182 return Diag(Loc: DiffDiagIDAt.first, PD: DiffDiagIDAt.second) << InlineSpec;
11183
11184 if (OldFD->getFormalLinkage() != NewFD->getFormalLinkage())
11185 return Diag(Loc: DiffDiagIDAt.first, PD: DiffDiagIDAt.second) << Linkage;
11186
11187 if (!CLinkageMayDiffer && OldFD->isExternC() != NewFD->isExternC())
11188 return Diag(Loc: DiffDiagIDAt.first, PD: DiffDiagIDAt.second) << LanguageLinkage;
11189
11190 if (CheckEquivalentExceptionSpec(Old: OldFPT, OldLoc: OldFD->getLocation(), New: NewFPT,
11191 NewLoc: NewFD->getLocation()))
11192 return true;
11193 }
11194 return false;
11195}
11196
11197static bool CheckMultiVersionAdditionalRules(Sema &S, const FunctionDecl *OldFD,
11198 const FunctionDecl *NewFD,
11199 bool CausesMV,
11200 MultiVersionKind MVKind) {
11201 if (!S.getASTContext().getTargetInfo().supportsMultiVersioning()) {
11202 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_multiversion_not_supported);
11203 if (OldFD)
11204 S.Diag(Loc: OldFD->getLocation(), DiagID: diag::note_previous_declaration);
11205 return true;
11206 }
11207
11208 bool IsCPUSpecificCPUDispatchMVKind =
11209 MVKind == MultiVersionKind::CPUDispatch ||
11210 MVKind == MultiVersionKind::CPUSpecific;
11211
11212 if (CausesMV && OldFD &&
11213 checkNonMultiVersionCompatAttributes(S, FD: OldFD, CausedFD: NewFD, MVKind))
11214 return true;
11215
11216 if (checkNonMultiVersionCompatAttributes(S, FD: NewFD, CausedFD: nullptr, MVKind))
11217 return true;
11218
11219 // Only allow transition to MultiVersion if it hasn't been used.
11220 if (OldFD && CausesMV && OldFD->isUsed(CheckUsedAttr: false))
11221 return S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_multiversion_after_used);
11222
11223 return S.areMultiversionVariantFunctionsCompatible(
11224 OldFD, NewFD, NoProtoDiagID: S.PDiag(DiagID: diag::err_multiversion_noproto),
11225 NoteCausedDiagIDAt: PartialDiagnosticAt(NewFD->getLocation(),
11226 S.PDiag(DiagID: diag::note_multiversioning_caused_here)),
11227 NoSupportDiagIDAt: PartialDiagnosticAt(NewFD->getLocation(),
11228 S.PDiag(DiagID: diag::err_multiversion_doesnt_support)
11229 << static_cast<unsigned>(MVKind)),
11230 DiffDiagIDAt: PartialDiagnosticAt(NewFD->getLocation(),
11231 S.PDiag(DiagID: diag::err_multiversion_diff)),
11232 /*TemplatesSupported=*/false,
11233 /*ConstexprSupported=*/!IsCPUSpecificCPUDispatchMVKind,
11234 /*CLinkageMayDiffer=*/false);
11235}
11236
11237/// Check the validity of a multiversion function declaration that is the
11238/// first of its kind. Also sets the multiversion'ness' of the function itself.
11239///
11240/// This sets NewFD->isInvalidDecl() to true if there was an error.
11241///
11242/// Returns true if there was an error, false otherwise.
11243static bool CheckMultiVersionFirstFunction(Sema &S, FunctionDecl *FD) {
11244 MultiVersionKind MVKind = FD->getMultiVersionKind();
11245 assert(MVKind != MultiVersionKind::None &&
11246 "Function lacks multiversion attribute");
11247 const auto *TA = FD->getAttr<TargetAttr>();
11248 const auto *TVA = FD->getAttr<TargetVersionAttr>();
11249 // The target attribute only causes MV if this declaration is the default,
11250 // otherwise it is treated as a normal function.
11251 if (TA && !TA->isDefaultVersion())
11252 return false;
11253 // The target_version attribute only causes Multiversioning if this
11254 // declaration is NOT the default version.
11255 if (TVA && TVA->isDefaultVersion())
11256 return false;
11257
11258 if ((TA || TVA) && CheckMultiVersionValue(S, FD)) {
11259 FD->setInvalidDecl();
11260 return true;
11261 }
11262
11263 if (CheckMultiVersionAdditionalRules(S, OldFD: nullptr, NewFD: FD, CausesMV: true, MVKind)) {
11264 FD->setInvalidDecl();
11265 return true;
11266 }
11267
11268 FD->setIsMultiVersion();
11269 return false;
11270}
11271
11272static bool PreviousDeclsHaveMultiVersionAttribute(const FunctionDecl *FD) {
11273 for (const Decl *D = FD->getPreviousDecl(); D; D = D->getPreviousDecl()) {
11274 if (D->getAsFunction()->getMultiVersionKind() != MultiVersionKind::None)
11275 return true;
11276 }
11277
11278 return false;
11279}
11280
11281static void patchDefaultTargetVersion(FunctionDecl *From, FunctionDecl *To) {
11282 if (!From->getASTContext().getTargetInfo().getTriple().isAArch64())
11283 return;
11284
11285 MultiVersionKind MVKindFrom = From->getMultiVersionKind();
11286 MultiVersionKind MVKindTo = To->getMultiVersionKind();
11287
11288 if (MVKindTo == MultiVersionKind::None &&
11289 (MVKindFrom == MultiVersionKind::TargetVersion ||
11290 MVKindFrom == MultiVersionKind::TargetClones))
11291 To->addAttr(A: TargetVersionAttr::CreateImplicit(
11292 Ctx&: To->getASTContext(), NamesStr: "default", Range: To->getSourceRange()));
11293}
11294
11295static bool CheckDeclarationCausesMultiVersioning(Sema &S, FunctionDecl *OldFD,
11296 FunctionDecl *NewFD,
11297 bool &Redeclaration,
11298 NamedDecl *&OldDecl,
11299 LookupResult &Previous) {
11300 assert(!OldFD->isMultiVersion() && "Unexpected MultiVersion");
11301
11302 // The definitions should be allowed in any order. If we have discovered
11303 // a new target version and the preceeding was the default, then add the
11304 // corresponding attribute to it.
11305 patchDefaultTargetVersion(From: NewFD, To: OldFD);
11306
11307 const auto *NewTA = NewFD->getAttr<TargetAttr>();
11308 const auto *NewTVA = NewFD->getAttr<TargetVersionAttr>();
11309 const auto *OldTA = OldFD->getAttr<TargetAttr>();
11310
11311 // If the old decl is NOT MultiVersioned yet, and we don't cause that
11312 // to change, this is a simple redeclaration.
11313 if (NewTA && !NewTA->isDefaultVersion() &&
11314 (!OldTA || OldTA->getFeaturesStr() == NewTA->getFeaturesStr()))
11315 return false;
11316
11317 // The target_version attribute only causes Multiversioning if this
11318 // declaration is NOT the default version.
11319 if (NewTVA && NewTVA->isDefaultVersion())
11320 return false;
11321
11322 // Otherwise, this decl causes MultiVersioning.
11323 if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD, CausesMV: true,
11324 MVKind: NewTVA ? MultiVersionKind::TargetVersion
11325 : MultiVersionKind::Target)) {
11326 NewFD->setInvalidDecl();
11327 return true;
11328 }
11329
11330 if (CheckMultiVersionValue(S, FD: NewFD)) {
11331 NewFD->setInvalidDecl();
11332 return true;
11333 }
11334
11335 // If this is 'default', permit the forward declaration.
11336 if (NewTA && NewTA->isDefaultVersion() && !OldTA) {
11337 Redeclaration = true;
11338 OldDecl = OldFD;
11339 OldFD->setIsMultiVersion();
11340 NewFD->setIsMultiVersion();
11341 return false;
11342 }
11343
11344 if (CheckMultiVersionValue(S, FD: OldFD)) {
11345 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::note_multiversioning_caused_here);
11346 NewFD->setInvalidDecl();
11347 return true;
11348 }
11349
11350 if (NewTA) {
11351 ParsedTargetAttr OldParsed =
11352 S.getASTContext().getTargetInfo().parseTargetAttr(
11353 Str: OldTA->getFeaturesStr());
11354 llvm::sort(C&: OldParsed.Features);
11355 ParsedTargetAttr NewParsed =
11356 S.getASTContext().getTargetInfo().parseTargetAttr(
11357 Str: NewTA->getFeaturesStr());
11358 // Sort order doesn't matter, it just needs to be consistent.
11359 llvm::sort(C&: NewParsed.Features);
11360 if (OldParsed == NewParsed) {
11361 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_multiversion_duplicate);
11362 S.Diag(Loc: OldFD->getLocation(), DiagID: diag::note_previous_declaration);
11363 NewFD->setInvalidDecl();
11364 return true;
11365 }
11366 }
11367
11368 for (const auto *FD : OldFD->redecls()) {
11369 const auto *CurTA = FD->getAttr<TargetAttr>();
11370 const auto *CurTVA = FD->getAttr<TargetVersionAttr>();
11371 // We allow forward declarations before ANY multiversioning attributes, but
11372 // nothing after the fact.
11373 if (PreviousDeclsHaveMultiVersionAttribute(FD) &&
11374 ((NewTA && (!CurTA || CurTA->isInherited())) ||
11375 (NewTVA && (!CurTVA || CurTVA->isInherited())))) {
11376 S.Diag(Loc: FD->getLocation(), DiagID: diag::err_multiversion_required_in_redecl)
11377 << (NewTA ? 0 : 2);
11378 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::note_multiversioning_caused_here);
11379 NewFD->setInvalidDecl();
11380 return true;
11381 }
11382 }
11383
11384 OldFD->setIsMultiVersion();
11385 NewFD->setIsMultiVersion();
11386 Redeclaration = false;
11387 OldDecl = nullptr;
11388 Previous.clear();
11389 return false;
11390}
11391
11392static bool MultiVersionTypesCompatible(FunctionDecl *Old, FunctionDecl *New) {
11393 MultiVersionKind OldKind = Old->getMultiVersionKind();
11394 MultiVersionKind NewKind = New->getMultiVersionKind();
11395
11396 if (OldKind == NewKind || OldKind == MultiVersionKind::None ||
11397 NewKind == MultiVersionKind::None)
11398 return true;
11399
11400 if (Old->getASTContext().getTargetInfo().getTriple().isAArch64()) {
11401 switch (OldKind) {
11402 case MultiVersionKind::TargetVersion:
11403 return NewKind == MultiVersionKind::TargetClones;
11404 case MultiVersionKind::TargetClones:
11405 return NewKind == MultiVersionKind::TargetVersion;
11406 default:
11407 return false;
11408 }
11409 } else {
11410 switch (OldKind) {
11411 case MultiVersionKind::CPUDispatch:
11412 return NewKind == MultiVersionKind::CPUSpecific;
11413 case MultiVersionKind::CPUSpecific:
11414 return NewKind == MultiVersionKind::CPUDispatch;
11415 default:
11416 return false;
11417 }
11418 }
11419}
11420
11421/// Check the validity of a new function declaration being added to an existing
11422/// multiversioned declaration collection.
11423static bool CheckMultiVersionAdditionalDecl(
11424 Sema &S, FunctionDecl *OldFD, FunctionDecl *NewFD,
11425 const CPUDispatchAttr *NewCPUDisp, const CPUSpecificAttr *NewCPUSpec,
11426 const TargetClonesAttr *NewClones, bool &Redeclaration, NamedDecl *&OldDecl,
11427 LookupResult &Previous) {
11428
11429 // Disallow mixing of multiversioning types.
11430 if (!MultiVersionTypesCompatible(Old: OldFD, New: NewFD)) {
11431 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_multiversion_types_mixed);
11432 S.Diag(Loc: OldFD->getLocation(), DiagID: diag::note_previous_declaration);
11433 NewFD->setInvalidDecl();
11434 return true;
11435 }
11436
11437 // Add the default target_version attribute if it's missing.
11438 patchDefaultTargetVersion(From: OldFD, To: NewFD);
11439 patchDefaultTargetVersion(From: NewFD, To: OldFD);
11440
11441 const auto *NewTA = NewFD->getAttr<TargetAttr>();
11442 const auto *NewTVA = NewFD->getAttr<TargetVersionAttr>();
11443 MultiVersionKind NewMVKind = NewFD->getMultiVersionKind();
11444 [[maybe_unused]] MultiVersionKind OldMVKind = OldFD->getMultiVersionKind();
11445
11446 ParsedTargetAttr NewParsed;
11447 if (NewTA) {
11448 NewParsed = S.getASTContext().getTargetInfo().parseTargetAttr(
11449 Str: NewTA->getFeaturesStr());
11450 llvm::sort(C&: NewParsed.Features);
11451 }
11452 llvm::SmallVector<StringRef, 8> NewFeats;
11453 if (NewTVA) {
11454 NewTVA->getFeatures(Out&: NewFeats);
11455 llvm::sort(C&: NewFeats);
11456 }
11457
11458 bool UseMemberUsingDeclRules =
11459 S.CurContext->isRecord() && !NewFD->getFriendObjectKind();
11460
11461 bool MayNeedOverloadableChecks =
11462 AllowOverloadingOfFunction(Previous, Context&: S.Context, New: NewFD);
11463
11464 // Next, check ALL non-invalid non-overloads to see if this is a redeclaration
11465 // of a previous member of the MultiVersion set.
11466 for (NamedDecl *ND : Previous) {
11467 FunctionDecl *CurFD = ND->getAsFunction();
11468 if (!CurFD || CurFD->isInvalidDecl())
11469 continue;
11470 if (MayNeedOverloadableChecks &&
11471 S.IsOverload(New: NewFD, Old: CurFD, UseMemberUsingDeclRules))
11472 continue;
11473
11474 switch (NewMVKind) {
11475 case MultiVersionKind::None:
11476 assert(OldMVKind == MultiVersionKind::TargetClones &&
11477 "Only target_clones can be omitted in subsequent declarations");
11478 break;
11479 case MultiVersionKind::Target: {
11480 const auto *CurTA = CurFD->getAttr<TargetAttr>();
11481 if (CurTA->getFeaturesStr() == NewTA->getFeaturesStr()) {
11482 NewFD->setIsMultiVersion();
11483 Redeclaration = true;
11484 OldDecl = ND;
11485 return false;
11486 }
11487
11488 ParsedTargetAttr CurParsed =
11489 S.getASTContext().getTargetInfo().parseTargetAttr(
11490 Str: CurTA->getFeaturesStr());
11491 llvm::sort(C&: CurParsed.Features);
11492 if (CurParsed == NewParsed) {
11493 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_multiversion_duplicate);
11494 S.Diag(Loc: CurFD->getLocation(), DiagID: diag::note_previous_declaration);
11495 NewFD->setInvalidDecl();
11496 return true;
11497 }
11498 break;
11499 }
11500 case MultiVersionKind::TargetVersion: {
11501 if (const auto *CurTVA = CurFD->getAttr<TargetVersionAttr>()) {
11502 if (CurTVA->getName() == NewTVA->getName()) {
11503 NewFD->setIsMultiVersion();
11504 Redeclaration = true;
11505 OldDecl = ND;
11506 return false;
11507 }
11508 llvm::SmallVector<StringRef, 8> CurFeats;
11509 CurTVA->getFeatures(Out&: CurFeats);
11510 llvm::sort(C&: CurFeats);
11511
11512 if (CurFeats == NewFeats) {
11513 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_multiversion_duplicate);
11514 S.Diag(Loc: CurFD->getLocation(), DiagID: diag::note_previous_declaration);
11515 NewFD->setInvalidDecl();
11516 return true;
11517 }
11518 } else if (const auto *CurClones = CurFD->getAttr<TargetClonesAttr>()) {
11519 // Default
11520 if (NewFeats.empty())
11521 break;
11522
11523 for (unsigned I = 0; I < CurClones->featuresStrs_size(); ++I) {
11524 llvm::SmallVector<StringRef, 8> CurFeats;
11525 CurClones->getFeatures(Out&: CurFeats, Index: I);
11526 llvm::sort(C&: CurFeats);
11527
11528 if (CurFeats == NewFeats) {
11529 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_multiversion_duplicate);
11530 S.Diag(Loc: CurFD->getLocation(), DiagID: diag::note_previous_declaration);
11531 NewFD->setInvalidDecl();
11532 return true;
11533 }
11534 }
11535 }
11536 break;
11537 }
11538 case MultiVersionKind::TargetClones: {
11539 assert(NewClones && "MultiVersionKind does not match attribute type");
11540 if (const auto *CurClones = CurFD->getAttr<TargetClonesAttr>()) {
11541 if (CurClones->featuresStrs_size() != NewClones->featuresStrs_size() ||
11542 !std::equal(CurClones->featuresStrs_begin(),
11543 CurClones->featuresStrs_end(),
11544 NewClones->featuresStrs_begin())) {
11545 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_target_clone_doesnt_match);
11546 S.Diag(Loc: CurFD->getLocation(), DiagID: diag::note_previous_declaration);
11547 NewFD->setInvalidDecl();
11548 return true;
11549 }
11550 } else if (const auto *CurTVA = CurFD->getAttr<TargetVersionAttr>()) {
11551 llvm::SmallVector<StringRef, 8> CurFeats;
11552 CurTVA->getFeatures(Out&: CurFeats);
11553 llvm::sort(C&: CurFeats);
11554
11555 // Default
11556 if (CurFeats.empty())
11557 break;
11558
11559 for (unsigned I = 0; I < NewClones->featuresStrs_size(); ++I) {
11560 NewFeats.clear();
11561 NewClones->getFeatures(Out&: NewFeats, Index: I);
11562 llvm::sort(C&: NewFeats);
11563
11564 if (CurFeats == NewFeats) {
11565 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_multiversion_duplicate);
11566 S.Diag(Loc: CurFD->getLocation(), DiagID: diag::note_previous_declaration);
11567 NewFD->setInvalidDecl();
11568 return true;
11569 }
11570 }
11571 break;
11572 }
11573 Redeclaration = true;
11574 OldDecl = CurFD;
11575 NewFD->setIsMultiVersion();
11576 return false;
11577 }
11578 case MultiVersionKind::CPUSpecific:
11579 case MultiVersionKind::CPUDispatch: {
11580 const auto *CurCPUSpec = CurFD->getAttr<CPUSpecificAttr>();
11581 const auto *CurCPUDisp = CurFD->getAttr<CPUDispatchAttr>();
11582 // Handle CPUDispatch/CPUSpecific versions.
11583 // Only 1 CPUDispatch function is allowed, this will make it go through
11584 // the redeclaration errors.
11585 if (NewMVKind == MultiVersionKind::CPUDispatch &&
11586 CurFD->hasAttr<CPUDispatchAttr>()) {
11587 if (CurCPUDisp->cpus_size() == NewCPUDisp->cpus_size() &&
11588 std::equal(
11589 CurCPUDisp->cpus_begin(), CurCPUDisp->cpus_end(),
11590 NewCPUDisp->cpus_begin(),
11591 [](const IdentifierInfo *Cur, const IdentifierInfo *New) {
11592 return Cur->getName() == New->getName();
11593 })) {
11594 NewFD->setIsMultiVersion();
11595 Redeclaration = true;
11596 OldDecl = ND;
11597 return false;
11598 }
11599
11600 // If the declarations don't match, this is an error condition.
11601 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_cpu_dispatch_mismatch);
11602 S.Diag(Loc: CurFD->getLocation(), DiagID: diag::note_previous_declaration);
11603 NewFD->setInvalidDecl();
11604 return true;
11605 }
11606 if (NewMVKind == MultiVersionKind::CPUSpecific && CurCPUSpec) {
11607 if (CurCPUSpec->cpus_size() == NewCPUSpec->cpus_size() &&
11608 std::equal(
11609 CurCPUSpec->cpus_begin(), CurCPUSpec->cpus_end(),
11610 NewCPUSpec->cpus_begin(),
11611 [](const IdentifierInfo *Cur, const IdentifierInfo *New) {
11612 return Cur->getName() == New->getName();
11613 })) {
11614 NewFD->setIsMultiVersion();
11615 Redeclaration = true;
11616 OldDecl = ND;
11617 return false;
11618 }
11619
11620 // Only 1 version of CPUSpecific is allowed for each CPU.
11621 for (const IdentifierInfo *CurII : CurCPUSpec->cpus()) {
11622 for (const IdentifierInfo *NewII : NewCPUSpec->cpus()) {
11623 if (CurII == NewII) {
11624 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_cpu_specific_multiple_defs)
11625 << NewII;
11626 S.Diag(Loc: CurFD->getLocation(), DiagID: diag::note_previous_declaration);
11627 NewFD->setInvalidDecl();
11628 return true;
11629 }
11630 }
11631 }
11632 }
11633 break;
11634 }
11635 }
11636 }
11637
11638 // Else, this is simply a non-redecl case. Checking the 'value' is only
11639 // necessary in the Target case, since The CPUSpecific/Dispatch cases are
11640 // handled in the attribute adding step.
11641 if ((NewMVKind == MultiVersionKind::TargetVersion ||
11642 NewMVKind == MultiVersionKind::Target) &&
11643 CheckMultiVersionValue(S, FD: NewFD)) {
11644 NewFD->setInvalidDecl();
11645 return true;
11646 }
11647
11648 if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD,
11649 CausesMV: !OldFD->isMultiVersion(), MVKind: NewMVKind)) {
11650 NewFD->setInvalidDecl();
11651 return true;
11652 }
11653
11654 // Permit forward declarations in the case where these two are compatible.
11655 if (!OldFD->isMultiVersion()) {
11656 OldFD->setIsMultiVersion();
11657 NewFD->setIsMultiVersion();
11658 Redeclaration = true;
11659 OldDecl = OldFD;
11660 return false;
11661 }
11662
11663 NewFD->setIsMultiVersion();
11664 Redeclaration = false;
11665 OldDecl = nullptr;
11666 Previous.clear();
11667 return false;
11668}
11669
11670/// Check the validity of a mulitversion function declaration.
11671/// Also sets the multiversion'ness' of the function itself.
11672///
11673/// This sets NewFD->isInvalidDecl() to true if there was an error.
11674///
11675/// Returns true if there was an error, false otherwise.
11676static bool CheckMultiVersionFunction(Sema &S, FunctionDecl *NewFD,
11677 bool &Redeclaration, NamedDecl *&OldDecl,
11678 LookupResult &Previous) {
11679 const auto *NewTA = NewFD->getAttr<TargetAttr>();
11680 const auto *NewTVA = NewFD->getAttr<TargetVersionAttr>();
11681 const auto *NewCPUDisp = NewFD->getAttr<CPUDispatchAttr>();
11682 const auto *NewCPUSpec = NewFD->getAttr<CPUSpecificAttr>();
11683 const auto *NewClones = NewFD->getAttr<TargetClonesAttr>();
11684 MultiVersionKind MVKind = NewFD->getMultiVersionKind();
11685
11686 // Main isn't allowed to become a multiversion function, however it IS
11687 // permitted to have 'main' be marked with the 'target' optimization hint,
11688 // for 'target_version' only default is allowed.
11689 if (NewFD->isMain()) {
11690 if (MVKind != MultiVersionKind::None &&
11691 !(MVKind == MultiVersionKind::Target && !NewTA->isDefaultVersion()) &&
11692 !(MVKind == MultiVersionKind::TargetVersion &&
11693 NewTVA->isDefaultVersion())) {
11694 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_multiversion_not_allowed_on_main);
11695 NewFD->setInvalidDecl();
11696 return true;
11697 }
11698 return false;
11699 }
11700
11701 const llvm::Triple &T = S.getASTContext().getTargetInfo().getTriple();
11702
11703 // Target attribute on AArch64 is not used for multiversioning
11704 if (NewTA && T.isAArch64())
11705 return false;
11706
11707 // Target attribute on RISCV is not used for multiversioning
11708 if (NewTA && T.isRISCV())
11709 return false;
11710
11711 if (!OldDecl || !OldDecl->getAsFunction() ||
11712 !OldDecl->getDeclContext()->getRedeclContext()->Equals(
11713 DC: NewFD->getDeclContext()->getRedeclContext())) {
11714 // If there's no previous declaration, AND this isn't attempting to cause
11715 // multiversioning, this isn't an error condition.
11716 if (MVKind == MultiVersionKind::None)
11717 return false;
11718 return CheckMultiVersionFirstFunction(S, FD: NewFD);
11719 }
11720
11721 FunctionDecl *OldFD = OldDecl->getAsFunction();
11722
11723 if (!OldFD->isMultiVersion() && MVKind == MultiVersionKind::None)
11724 return false;
11725
11726 // Multiversioned redeclarations aren't allowed to omit the attribute, except
11727 // for target_clones and target_version.
11728 if (OldFD->isMultiVersion() && MVKind == MultiVersionKind::None &&
11729 OldFD->getMultiVersionKind() != MultiVersionKind::TargetClones &&
11730 OldFD->getMultiVersionKind() != MultiVersionKind::TargetVersion) {
11731 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_multiversion_required_in_redecl)
11732 << (OldFD->getMultiVersionKind() != MultiVersionKind::Target);
11733 NewFD->setInvalidDecl();
11734 return true;
11735 }
11736
11737 if (!OldFD->isMultiVersion()) {
11738 switch (MVKind) {
11739 case MultiVersionKind::Target:
11740 case MultiVersionKind::TargetVersion:
11741 return CheckDeclarationCausesMultiVersioning(
11742 S, OldFD, NewFD, Redeclaration, OldDecl, Previous);
11743 case MultiVersionKind::TargetClones:
11744 if (OldFD->isUsed(CheckUsedAttr: false)) {
11745 NewFD->setInvalidDecl();
11746 return S.Diag(Loc: NewFD->getLocation(), DiagID: diag::err_multiversion_after_used);
11747 }
11748 OldFD->setIsMultiVersion();
11749 break;
11750
11751 case MultiVersionKind::CPUDispatch:
11752 case MultiVersionKind::CPUSpecific:
11753 case MultiVersionKind::None:
11754 break;
11755 }
11756 }
11757
11758 // At this point, we have a multiversion function decl (in OldFD) AND an
11759 // appropriate attribute in the current function decl. Resolve that these are
11760 // still compatible with previous declarations.
11761 return CheckMultiVersionAdditionalDecl(S, OldFD, NewFD, NewCPUDisp,
11762 NewCPUSpec, NewClones, Redeclaration,
11763 OldDecl, Previous);
11764}
11765
11766static void CheckConstPureAttributesUsage(Sema &S, FunctionDecl *NewFD) {
11767 bool IsPure = NewFD->hasAttr<PureAttr>();
11768 bool IsConst = NewFD->hasAttr<ConstAttr>();
11769
11770 // If there are no pure or const attributes, there's nothing to check.
11771 if (!IsPure && !IsConst)
11772 return;
11773
11774 // If the function is marked both pure and const, we retain the const
11775 // attribute because it makes stronger guarantees than the pure attribute, and
11776 // we drop the pure attribute explicitly to prevent later confusion about
11777 // semantics.
11778 if (IsPure && IsConst) {
11779 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::warn_const_attr_with_pure_attr);
11780 NewFD->dropAttrs<PureAttr>();
11781 }
11782
11783 // Constructors and destructors are functions which return void, so are
11784 // handled here as well.
11785 if (NewFD->getReturnType()->isVoidType()) {
11786 S.Diag(Loc: NewFD->getLocation(), DiagID: diag::warn_pure_function_returns_void)
11787 << IsConst;
11788 NewFD->dropAttrs<PureAttr, ConstAttr>();
11789 }
11790}
11791
11792bool Sema::CheckFunctionDeclaration(Scope *S, FunctionDecl *NewFD,
11793 LookupResult &Previous,
11794 bool IsMemberSpecialization,
11795 bool DeclIsDefn) {
11796 assert(!NewFD->getReturnType()->isVariablyModifiedType() &&
11797 "Variably modified return types are not handled here");
11798
11799 // Determine whether the type of this function should be merged with
11800 // a previous visible declaration. This never happens for functions in C++,
11801 // and always happens in C if the previous declaration was visible.
11802 bool MergeTypeWithPrevious = !getLangOpts().CPlusPlus &&
11803 !Previous.isShadowed();
11804
11805 bool Redeclaration = false;
11806 NamedDecl *OldDecl = nullptr;
11807 bool MayNeedOverloadableChecks = false;
11808
11809 // Merge or overload the declaration with an existing declaration of
11810 // the same name, if appropriate.
11811 if (!Previous.empty()) {
11812 // Determine whether NewFD is an overload of PrevDecl or
11813 // a declaration that requires merging. If it's an overload,
11814 // there's no more work to do here; we'll just add the new
11815 // function to the scope.
11816 if (!AllowOverloadingOfFunction(Previous, Context, New: NewFD)) {
11817 NamedDecl *Candidate = Previous.getRepresentativeDecl();
11818 if (shouldLinkPossiblyHiddenDecl(Old: Candidate, New: NewFD)) {
11819 Redeclaration = true;
11820 OldDecl = Candidate;
11821 }
11822 } else {
11823 MayNeedOverloadableChecks = true;
11824 switch (CheckOverload(S, New: NewFD, OldDecls: Previous, OldDecl,
11825 /*NewIsUsingDecl*/ UseMemberUsingDeclRules: false)) {
11826 case Ovl_Match:
11827 Redeclaration = true;
11828 break;
11829
11830 case Ovl_NonFunction:
11831 Redeclaration = true;
11832 break;
11833
11834 case Ovl_Overload:
11835 Redeclaration = false;
11836 break;
11837 }
11838 }
11839 }
11840
11841 // Check for a previous extern "C" declaration with this name.
11842 if (!Redeclaration &&
11843 checkForConflictWithNonVisibleExternC(S&: *this, ND: NewFD, Previous)) {
11844 if (!Previous.empty()) {
11845 // This is an extern "C" declaration with the same name as a previous
11846 // declaration, and thus redeclares that entity...
11847 Redeclaration = true;
11848 OldDecl = Previous.getFoundDecl();
11849 MergeTypeWithPrevious = false;
11850
11851 // ... except in the presence of __attribute__((overloadable)).
11852 if (OldDecl->hasAttr<OverloadableAttr>() ||
11853 NewFD->hasAttr<OverloadableAttr>()) {
11854 if (IsOverload(New: NewFD, Old: cast<FunctionDecl>(Val: OldDecl), UseMemberUsingDeclRules: false)) {
11855 MayNeedOverloadableChecks = true;
11856 Redeclaration = false;
11857 OldDecl = nullptr;
11858 }
11859 }
11860 }
11861 }
11862
11863 if (CheckMultiVersionFunction(S&: *this, NewFD, Redeclaration, OldDecl, Previous))
11864 return Redeclaration;
11865
11866 // PPC MMA non-pointer types are not allowed as function return types.
11867 if (Context.getTargetInfo().getTriple().isPPC64() &&
11868 PPC().CheckPPCMMAType(Type: NewFD->getReturnType(), TypeLoc: NewFD->getLocation())) {
11869 NewFD->setInvalidDecl();
11870 }
11871
11872 CheckConstPureAttributesUsage(S&: *this, NewFD);
11873
11874 // C++ [dcl.spec.auto.general]p12:
11875 // Return type deduction for a templated function with a placeholder in its
11876 // declared type occurs when the definition is instantiated even if the
11877 // function body contains a return statement with a non-type-dependent
11878 // operand.
11879 //
11880 // C++ [temp.dep.expr]p3:
11881 // An id-expression is type-dependent if it is a template-id that is not a
11882 // concept-id and is dependent; or if its terminal name is:
11883 // - [...]
11884 // - associated by name lookup with one or more declarations of member
11885 // functions of a class that is the current instantiation declared with a
11886 // return type that contains a placeholder type,
11887 // - [...]
11888 //
11889 // If this is a templated function with a placeholder in its return type,
11890 // make the placeholder type dependent since it won't be deduced until the
11891 // definition is instantiated. We do this here because it needs to happen
11892 // for implicitly instantiated member functions/member function templates.
11893 if (getLangOpts().CPlusPlus14 &&
11894 (NewFD->isDependentContext() &&
11895 NewFD->getReturnType()->isUndeducedType())) {
11896 const FunctionProtoType *FPT =
11897 NewFD->getType()->castAs<FunctionProtoType>();
11898 QualType NewReturnType = SubstAutoTypeDependent(TypeWithAuto: FPT->getReturnType());
11899 NewFD->setType(Context.getFunctionType(ResultTy: NewReturnType, Args: FPT->getParamTypes(),
11900 EPI: FPT->getExtProtoInfo()));
11901 }
11902
11903 // C++11 [dcl.constexpr]p8:
11904 // A constexpr specifier for a non-static member function that is not
11905 // a constructor declares that member function to be const.
11906 //
11907 // This needs to be delayed until we know whether this is an out-of-line
11908 // definition of a static member function.
11909 //
11910 // This rule is not present in C++1y, so we produce a backwards
11911 // compatibility warning whenever it happens in C++11.
11912 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Val: NewFD);
11913 if (!getLangOpts().CPlusPlus14 && MD && MD->isConstexpr() &&
11914 !MD->isStatic() && !isa<CXXConstructorDecl>(Val: MD) &&
11915 !isa<CXXDestructorDecl>(Val: MD) && !MD->getMethodQualifiers().hasConst()) {
11916 CXXMethodDecl *OldMD = nullptr;
11917 if (OldDecl)
11918 OldMD = dyn_cast_or_null<CXXMethodDecl>(Val: OldDecl->getAsFunction());
11919 if (!OldMD || !OldMD->isStatic()) {
11920 const FunctionProtoType *FPT =
11921 MD->getType()->castAs<FunctionProtoType>();
11922 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
11923 EPI.TypeQuals.addConst();
11924 MD->setType(Context.getFunctionType(ResultTy: FPT->getReturnType(),
11925 Args: FPT->getParamTypes(), EPI));
11926
11927 // Warn that we did this, if we're not performing template instantiation.
11928 // In that case, we'll have warned already when the template was defined.
11929 if (!inTemplateInstantiation()) {
11930 SourceLocation AddConstLoc;
11931 if (FunctionTypeLoc FTL = MD->getTypeSourceInfo()->getTypeLoc()
11932 .IgnoreParens().getAs<FunctionTypeLoc>())
11933 AddConstLoc = getLocForEndOfToken(Loc: FTL.getRParenLoc());
11934
11935 Diag(Loc: MD->getLocation(), DiagID: diag::warn_cxx14_compat_constexpr_not_const)
11936 << FixItHint::CreateInsertion(InsertionLoc: AddConstLoc, Code: " const");
11937 }
11938 }
11939 }
11940
11941 if (Redeclaration) {
11942 // NewFD and OldDecl represent declarations that need to be
11943 // merged.
11944 if (MergeFunctionDecl(New: NewFD, OldD&: OldDecl, S, MergeTypeWithOld: MergeTypeWithPrevious,
11945 NewDeclIsDefn: DeclIsDefn)) {
11946 NewFD->setInvalidDecl();
11947 return Redeclaration;
11948 }
11949
11950 Previous.clear();
11951 Previous.addDecl(D: OldDecl);
11952
11953 if (FunctionTemplateDecl *OldTemplateDecl =
11954 dyn_cast<FunctionTemplateDecl>(Val: OldDecl)) {
11955 auto *OldFD = OldTemplateDecl->getTemplatedDecl();
11956 FunctionTemplateDecl *NewTemplateDecl
11957 = NewFD->getDescribedFunctionTemplate();
11958 assert(NewTemplateDecl && "Template/non-template mismatch");
11959
11960 // The call to MergeFunctionDecl above may have created some state in
11961 // NewTemplateDecl that needs to be merged with OldTemplateDecl before we
11962 // can add it as a redeclaration.
11963 NewTemplateDecl->mergePrevDecl(Prev: OldTemplateDecl);
11964
11965 NewFD->setPreviousDeclaration(OldFD);
11966 if (NewFD->isCXXClassMember()) {
11967 NewFD->setAccess(OldTemplateDecl->getAccess());
11968 NewTemplateDecl->setAccess(OldTemplateDecl->getAccess());
11969 }
11970
11971 // If this is an explicit specialization of a member that is a function
11972 // template, mark it as a member specialization.
11973 if (IsMemberSpecialization &&
11974 NewTemplateDecl->getInstantiatedFromMemberTemplate()) {
11975 NewTemplateDecl->setMemberSpecialization();
11976 assert(OldTemplateDecl->isMemberSpecialization());
11977 // Explicit specializations of a member template do not inherit deleted
11978 // status from the parent member template that they are specializing.
11979 if (OldFD->isDeleted()) {
11980 // FIXME: This assert will not hold in the presence of modules.
11981 assert(OldFD->getCanonicalDecl() == OldFD);
11982 // FIXME: We need an update record for this AST mutation.
11983 OldFD->setDeletedAsWritten(D: false);
11984 }
11985 }
11986
11987 } else {
11988 if (shouldLinkDependentDeclWithPrevious(D: NewFD, PrevDecl: OldDecl)) {
11989 auto *OldFD = cast<FunctionDecl>(Val: OldDecl);
11990 // This needs to happen first so that 'inline' propagates.
11991 NewFD->setPreviousDeclaration(OldFD);
11992 if (NewFD->isCXXClassMember())
11993 NewFD->setAccess(OldFD->getAccess());
11994 }
11995 }
11996 } else if (!getLangOpts().CPlusPlus && MayNeedOverloadableChecks &&
11997 !NewFD->getAttr<OverloadableAttr>()) {
11998 assert((Previous.empty() ||
11999 llvm::any_of(Previous,
12000 [](const NamedDecl *ND) {
12001 return ND->hasAttr<OverloadableAttr>();
12002 })) &&
12003 "Non-redecls shouldn't happen without overloadable present");
12004
12005 auto OtherUnmarkedIter = llvm::find_if(Range&: Previous, P: [](const NamedDecl *ND) {
12006 const auto *FD = dyn_cast<FunctionDecl>(Val: ND);
12007 return FD && !FD->hasAttr<OverloadableAttr>();
12008 });
12009
12010 if (OtherUnmarkedIter != Previous.end()) {
12011 Diag(Loc: NewFD->getLocation(),
12012 DiagID: diag::err_attribute_overloadable_multiple_unmarked_overloads);
12013 Diag(Loc: (*OtherUnmarkedIter)->getLocation(),
12014 DiagID: diag::note_attribute_overloadable_prev_overload)
12015 << false;
12016
12017 NewFD->addAttr(A: OverloadableAttr::CreateImplicit(Ctx&: Context));
12018 }
12019 }
12020
12021 if (LangOpts.OpenMP)
12022 OpenMP().ActOnFinishedFunctionDefinitionInOpenMPAssumeScope(D: NewFD);
12023
12024 // Semantic checking for this function declaration (in isolation).
12025
12026 if (getLangOpts().CPlusPlus) {
12027 // C++-specific checks.
12028 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Val: NewFD)) {
12029 CheckConstructor(Constructor);
12030 } else if (CXXDestructorDecl *Destructor =
12031 dyn_cast<CXXDestructorDecl>(Val: NewFD)) {
12032 // We check here for invalid destructor names.
12033 // If we have a friend destructor declaration that is dependent, we can't
12034 // diagnose right away because cases like this are still valid:
12035 // template <class T> struct A { friend T::X::~Y(); };
12036 // struct B { struct Y { ~Y(); }; using X = Y; };
12037 // template struct A<B>;
12038 if (NewFD->getFriendObjectKind() == Decl::FriendObjectKind::FOK_None ||
12039 !Destructor->getFunctionObjectParameterType()->isDependentType()) {
12040 CXXRecordDecl *Record = Destructor->getParent();
12041 QualType ClassType = Context.getTypeDeclType(Decl: Record);
12042
12043 DeclarationName Name = Context.DeclarationNames.getCXXDestructorName(
12044 Ty: Context.getCanonicalType(T: ClassType));
12045 if (NewFD->getDeclName() != Name) {
12046 Diag(Loc: NewFD->getLocation(), DiagID: diag::err_destructor_name);
12047 NewFD->setInvalidDecl();
12048 return Redeclaration;
12049 }
12050 }
12051 } else if (auto *Guide = dyn_cast<CXXDeductionGuideDecl>(Val: NewFD)) {
12052 if (auto *TD = Guide->getDescribedFunctionTemplate())
12053 CheckDeductionGuideTemplate(TD);
12054
12055 // A deduction guide is not on the list of entities that can be
12056 // explicitly specialized.
12057 if (Guide->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
12058 Diag(Loc: Guide->getBeginLoc(), DiagID: diag::err_deduction_guide_specialized)
12059 << /*explicit specialization*/ 1;
12060 }
12061
12062 // Find any virtual functions that this function overrides.
12063 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Val: NewFD)) {
12064 if (!Method->isFunctionTemplateSpecialization() &&
12065 !Method->getDescribedFunctionTemplate() &&
12066 Method->isCanonicalDecl()) {
12067 AddOverriddenMethods(DC: Method->getParent(), MD: Method);
12068 }
12069 if (Method->isVirtual() && NewFD->getTrailingRequiresClause())
12070 // C++2a [class.virtual]p6
12071 // A virtual method shall not have a requires-clause.
12072 Diag(Loc: NewFD->getTrailingRequiresClause()->getBeginLoc(),
12073 DiagID: diag::err_constrained_virtual_method);
12074
12075 if (Method->isStatic())
12076 checkThisInStaticMemberFunctionType(Method);
12077 }
12078
12079 if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(Val: NewFD))
12080 ActOnConversionDeclarator(Conversion);
12081
12082 // Extra checking for C++ overloaded operators (C++ [over.oper]).
12083 if (NewFD->isOverloadedOperator() &&
12084 CheckOverloadedOperatorDeclaration(FnDecl: NewFD)) {
12085 NewFD->setInvalidDecl();
12086 return Redeclaration;
12087 }
12088
12089 // Extra checking for C++0x literal operators (C++0x [over.literal]).
12090 if (NewFD->getLiteralIdentifier() &&
12091 CheckLiteralOperatorDeclaration(FnDecl: NewFD)) {
12092 NewFD->setInvalidDecl();
12093 return Redeclaration;
12094 }
12095
12096 // In C++, check default arguments now that we have merged decls. Unless
12097 // the lexical context is the class, because in this case this is done
12098 // during delayed parsing anyway.
12099 if (!CurContext->isRecord())
12100 CheckCXXDefaultArguments(FD: NewFD);
12101
12102 // If this function is declared as being extern "C", then check to see if
12103 // the function returns a UDT (class, struct, or union type) that is not C
12104 // compatible, and if it does, warn the user.
12105 // But, issue any diagnostic on the first declaration only.
12106 if (Previous.empty() && NewFD->isExternC()) {
12107 QualType R = NewFD->getReturnType();
12108 if (R->isIncompleteType() && !R->isVoidType())
12109 Diag(Loc: NewFD->getLocation(), DiagID: diag::warn_return_value_udt_incomplete)
12110 << NewFD << R;
12111 else if (!R.isPODType(Context) && !R->isVoidType() &&
12112 !R->isObjCObjectPointerType())
12113 Diag(Loc: NewFD->getLocation(), DiagID: diag::warn_return_value_udt) << NewFD << R;
12114 }
12115
12116 // C++1z [dcl.fct]p6:
12117 // [...] whether the function has a non-throwing exception-specification
12118 // [is] part of the function type
12119 //
12120 // This results in an ABI break between C++14 and C++17 for functions whose
12121 // declared type includes an exception-specification in a parameter or
12122 // return type. (Exception specifications on the function itself are OK in
12123 // most cases, and exception specifications are not permitted in most other
12124 // contexts where they could make it into a mangling.)
12125 if (!getLangOpts().CPlusPlus17 && !NewFD->getPrimaryTemplate()) {
12126 auto HasNoexcept = [&](QualType T) -> bool {
12127 // Strip off declarator chunks that could be between us and a function
12128 // type. We don't need to look far, exception specifications are very
12129 // restricted prior to C++17.
12130 if (auto *RT = T->getAs<ReferenceType>())
12131 T = RT->getPointeeType();
12132 else if (T->isAnyPointerType())
12133 T = T->getPointeeType();
12134 else if (auto *MPT = T->getAs<MemberPointerType>())
12135 T = MPT->getPointeeType();
12136 if (auto *FPT = T->getAs<FunctionProtoType>())
12137 if (FPT->isNothrow())
12138 return true;
12139 return false;
12140 };
12141
12142 auto *FPT = NewFD->getType()->castAs<FunctionProtoType>();
12143 bool AnyNoexcept = HasNoexcept(FPT->getReturnType());
12144 for (QualType T : FPT->param_types())
12145 AnyNoexcept |= HasNoexcept(T);
12146 if (AnyNoexcept)
12147 Diag(Loc: NewFD->getLocation(),
12148 DiagID: diag::warn_cxx17_compat_exception_spec_in_signature)
12149 << NewFD;
12150 }
12151
12152 if (!Redeclaration && LangOpts.CUDA)
12153 CUDA().checkTargetOverload(NewFD, Previous);
12154 }
12155
12156 // Check if the function definition uses any AArch64 SME features without
12157 // having the '+sme' feature enabled and warn user if sme locally streaming
12158 // function returns or uses arguments with VL-based types.
12159 if (DeclIsDefn) {
12160 const auto *Attr = NewFD->getAttr<ArmNewAttr>();
12161 bool UsesSM = NewFD->hasAttr<ArmLocallyStreamingAttr>();
12162 bool UsesZA = Attr && Attr->isNewZA();
12163 bool UsesZT0 = Attr && Attr->isNewZT0();
12164
12165 if (NewFD->hasAttr<ArmLocallyStreamingAttr>()) {
12166 if (NewFD->getReturnType()->isSizelessVectorType())
12167 Diag(Loc: NewFD->getLocation(),
12168 DiagID: diag::warn_sme_locally_streaming_has_vl_args_returns)
12169 << /*IsArg=*/false;
12170 if (llvm::any_of(Range: NewFD->parameters(), P: [](ParmVarDecl *P) {
12171 return P->getOriginalType()->isSizelessVectorType();
12172 }))
12173 Diag(Loc: NewFD->getLocation(),
12174 DiagID: diag::warn_sme_locally_streaming_has_vl_args_returns)
12175 << /*IsArg=*/true;
12176 }
12177 if (const auto *FPT = NewFD->getType()->getAs<FunctionProtoType>()) {
12178 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
12179 UsesSM |=
12180 EPI.AArch64SMEAttributes & FunctionType::SME_PStateSMEnabledMask;
12181 UsesZA |= FunctionType::getArmZAState(AttrBits: EPI.AArch64SMEAttributes) !=
12182 FunctionType::ARM_None;
12183 UsesZT0 |= FunctionType::getArmZT0State(AttrBits: EPI.AArch64SMEAttributes) !=
12184 FunctionType::ARM_None;
12185 }
12186
12187 if (UsesSM || UsesZA) {
12188 llvm::StringMap<bool> FeatureMap;
12189 Context.getFunctionFeatureMap(FeatureMap, NewFD);
12190 if (!FeatureMap.contains(Key: "sme")) {
12191 if (UsesSM)
12192 Diag(Loc: NewFD->getLocation(),
12193 DiagID: diag::err_sme_definition_using_sm_in_non_sme_target);
12194 else
12195 Diag(Loc: NewFD->getLocation(),
12196 DiagID: diag::err_sme_definition_using_za_in_non_sme_target);
12197 }
12198 }
12199 if (UsesZT0) {
12200 llvm::StringMap<bool> FeatureMap;
12201 Context.getFunctionFeatureMap(FeatureMap, NewFD);
12202 if (!FeatureMap.contains(Key: "sme2")) {
12203 Diag(Loc: NewFD->getLocation(),
12204 DiagID: diag::err_sme_definition_using_zt0_in_non_sme2_target);
12205 }
12206 }
12207 }
12208
12209 return Redeclaration;
12210}
12211
12212void Sema::CheckMain(FunctionDecl* FD, const DeclSpec& DS) {
12213 // C++11 [basic.start.main]p3:
12214 // A program that [...] declares main to be inline, static or
12215 // constexpr is ill-formed.
12216 // C11 6.7.4p4: In a hosted environment, no function specifier(s) shall
12217 // appear in a declaration of main.
12218 // static main is not an error under C99, but we should warn about it.
12219 // We accept _Noreturn main as an extension.
12220 if (FD->getStorageClass() == SC_Static)
12221 Diag(Loc: DS.getStorageClassSpecLoc(), DiagID: getLangOpts().CPlusPlus
12222 ? diag::err_static_main : diag::warn_static_main)
12223 << FixItHint::CreateRemoval(RemoveRange: DS.getStorageClassSpecLoc());
12224 if (FD->isInlineSpecified())
12225 Diag(Loc: DS.getInlineSpecLoc(), DiagID: diag::err_inline_main)
12226 << FixItHint::CreateRemoval(RemoveRange: DS.getInlineSpecLoc());
12227 if (DS.isNoreturnSpecified()) {
12228 SourceLocation NoreturnLoc = DS.getNoreturnSpecLoc();
12229 SourceRange NoreturnRange(NoreturnLoc, getLocForEndOfToken(Loc: NoreturnLoc));
12230 Diag(Loc: NoreturnLoc, DiagID: diag::ext_noreturn_main);
12231 Diag(Loc: NoreturnLoc, DiagID: diag::note_main_remove_noreturn)
12232 << FixItHint::CreateRemoval(RemoveRange: NoreturnRange);
12233 }
12234 if (FD->isConstexpr()) {
12235 Diag(Loc: DS.getConstexprSpecLoc(), DiagID: diag::err_constexpr_main)
12236 << FD->isConsteval()
12237 << FixItHint::CreateRemoval(RemoveRange: DS.getConstexprSpecLoc());
12238 FD->setConstexprKind(ConstexprSpecKind::Unspecified);
12239 }
12240
12241 if (getLangOpts().OpenCL) {
12242 Diag(Loc: FD->getLocation(), DiagID: diag::err_opencl_no_main)
12243 << FD->hasAttr<OpenCLKernelAttr>();
12244 FD->setInvalidDecl();
12245 return;
12246 }
12247
12248 // Functions named main in hlsl are default entries, but don't have specific
12249 // signatures they are required to conform to.
12250 if (getLangOpts().HLSL)
12251 return;
12252
12253 QualType T = FD->getType();
12254 assert(T->isFunctionType() && "function decl is not of function type");
12255 const FunctionType* FT = T->castAs<FunctionType>();
12256
12257 // Set default calling convention for main()
12258 if (FT->getCallConv() != CC_C) {
12259 FT = Context.adjustFunctionType(Fn: FT, EInfo: FT->getExtInfo().withCallingConv(cc: CC_C));
12260 FD->setType(QualType(FT, 0));
12261 T = Context.getCanonicalType(T: FD->getType());
12262 }
12263
12264 if (getLangOpts().GNUMode && !getLangOpts().CPlusPlus) {
12265 // In C with GNU extensions we allow main() to have non-integer return
12266 // type, but we should warn about the extension, and we disable the
12267 // implicit-return-zero rule.
12268
12269 // GCC in C mode accepts qualified 'int'.
12270 if (Context.hasSameUnqualifiedType(T1: FT->getReturnType(), T2: Context.IntTy))
12271 FD->setHasImplicitReturnZero(true);
12272 else {
12273 Diag(Loc: FD->getTypeSpecStartLoc(), DiagID: diag::ext_main_returns_nonint);
12274 SourceRange RTRange = FD->getReturnTypeSourceRange();
12275 if (RTRange.isValid())
12276 Diag(Loc: RTRange.getBegin(), DiagID: diag::note_main_change_return_type)
12277 << FixItHint::CreateReplacement(RemoveRange: RTRange, Code: "int");
12278 }
12279 } else {
12280 // In C and C++, main magically returns 0 if you fall off the end;
12281 // set the flag which tells us that.
12282 // This is C++ [basic.start.main]p5 and C99 5.1.2.2.3.
12283
12284 // All the standards say that main() should return 'int'.
12285 if (Context.hasSameType(T1: FT->getReturnType(), T2: Context.IntTy))
12286 FD->setHasImplicitReturnZero(true);
12287 else {
12288 // Otherwise, this is just a flat-out error.
12289 SourceRange RTRange = FD->getReturnTypeSourceRange();
12290 Diag(Loc: FD->getTypeSpecStartLoc(), DiagID: diag::err_main_returns_nonint)
12291 << (RTRange.isValid() ? FixItHint::CreateReplacement(RemoveRange: RTRange, Code: "int")
12292 : FixItHint());
12293 FD->setInvalidDecl(true);
12294 }
12295 }
12296
12297 // Treat protoless main() as nullary.
12298 if (isa<FunctionNoProtoType>(Val: FT)) return;
12299
12300 const FunctionProtoType* FTP = cast<const FunctionProtoType>(Val: FT);
12301 unsigned nparams = FTP->getNumParams();
12302 assert(FD->getNumParams() == nparams);
12303
12304 bool HasExtraParameters = (nparams > 3);
12305
12306 if (FTP->isVariadic()) {
12307 Diag(Loc: FD->getLocation(), DiagID: diag::ext_variadic_main);
12308 // FIXME: if we had information about the location of the ellipsis, we
12309 // could add a FixIt hint to remove it as a parameter.
12310 }
12311
12312 // Darwin passes an undocumented fourth argument of type char**. If
12313 // other platforms start sprouting these, the logic below will start
12314 // getting shifty.
12315 if (nparams == 4 && Context.getTargetInfo().getTriple().isOSDarwin())
12316 HasExtraParameters = false;
12317
12318 if (HasExtraParameters) {
12319 Diag(Loc: FD->getLocation(), DiagID: diag::err_main_surplus_args) << nparams;
12320 FD->setInvalidDecl(true);
12321 nparams = 3;
12322 }
12323
12324 // FIXME: a lot of the following diagnostics would be improved
12325 // if we had some location information about types.
12326
12327 QualType CharPP =
12328 Context.getPointerType(T: Context.getPointerType(T: Context.CharTy));
12329 QualType Expected[] = { Context.IntTy, CharPP, CharPP, CharPP };
12330
12331 for (unsigned i = 0; i < nparams; ++i) {
12332 QualType AT = FTP->getParamType(i);
12333
12334 bool mismatch = true;
12335
12336 if (Context.hasSameUnqualifiedType(T1: AT, T2: Expected[i]))
12337 mismatch = false;
12338 else if (Expected[i] == CharPP) {
12339 // As an extension, the following forms are okay:
12340 // char const **
12341 // char const * const *
12342 // char * const *
12343
12344 QualifierCollector qs;
12345 const PointerType* PT;
12346 if ((PT = qs.strip(type: AT)->getAs<PointerType>()) &&
12347 (PT = qs.strip(type: PT->getPointeeType())->getAs<PointerType>()) &&
12348 Context.hasSameType(T1: QualType(qs.strip(type: PT->getPointeeType()), 0),
12349 T2: Context.CharTy)) {
12350 qs.removeConst();
12351 mismatch = !qs.empty();
12352 }
12353 }
12354
12355 if (mismatch) {
12356 Diag(Loc: FD->getLocation(), DiagID: diag::err_main_arg_wrong) << i << Expected[i];
12357 // TODO: suggest replacing given type with expected type
12358 FD->setInvalidDecl(true);
12359 }
12360 }
12361
12362 if (nparams == 1 && !FD->isInvalidDecl()) {
12363 Diag(Loc: FD->getLocation(), DiagID: diag::warn_main_one_arg);
12364 }
12365
12366 if (!FD->isInvalidDecl() && FD->getDescribedFunctionTemplate()) {
12367 Diag(Loc: FD->getLocation(), DiagID: diag::err_mainlike_template_decl) << FD;
12368 FD->setInvalidDecl();
12369 }
12370}
12371
12372static bool isDefaultStdCall(FunctionDecl *FD, Sema &S) {
12373
12374 // Default calling convention for main and wmain is __cdecl
12375 if (FD->getName() == "main" || FD->getName() == "wmain")
12376 return false;
12377
12378 // Default calling convention for MinGW is __cdecl
12379 const llvm::Triple &T = S.Context.getTargetInfo().getTriple();
12380 if (T.isWindowsGNUEnvironment())
12381 return false;
12382
12383 // Default calling convention for WinMain, wWinMain and DllMain
12384 // is __stdcall on 32 bit Windows
12385 if (T.isOSWindows() && T.getArch() == llvm::Triple::x86)
12386 return true;
12387
12388 return false;
12389}
12390
12391void Sema::CheckMSVCRTEntryPoint(FunctionDecl *FD) {
12392 QualType T = FD->getType();
12393 assert(T->isFunctionType() && "function decl is not of function type");
12394 const FunctionType *FT = T->castAs<FunctionType>();
12395
12396 // Set an implicit return of 'zero' if the function can return some integral,
12397 // enumeration, pointer or nullptr type.
12398 if (FT->getReturnType()->isIntegralOrEnumerationType() ||
12399 FT->getReturnType()->isAnyPointerType() ||
12400 FT->getReturnType()->isNullPtrType())
12401 // DllMain is exempt because a return value of zero means it failed.
12402 if (FD->getName() != "DllMain")
12403 FD->setHasImplicitReturnZero(true);
12404
12405 // Explicitly specified calling conventions are applied to MSVC entry points
12406 if (!hasExplicitCallingConv(T)) {
12407 if (isDefaultStdCall(FD, S&: *this)) {
12408 if (FT->getCallConv() != CC_X86StdCall) {
12409 FT = Context.adjustFunctionType(
12410 Fn: FT, EInfo: FT->getExtInfo().withCallingConv(cc: CC_X86StdCall));
12411 FD->setType(QualType(FT, 0));
12412 }
12413 } else if (FT->getCallConv() != CC_C) {
12414 FT = Context.adjustFunctionType(Fn: FT,
12415 EInfo: FT->getExtInfo().withCallingConv(cc: CC_C));
12416 FD->setType(QualType(FT, 0));
12417 }
12418 }
12419
12420 if (!FD->isInvalidDecl() && FD->getDescribedFunctionTemplate()) {
12421 Diag(Loc: FD->getLocation(), DiagID: diag::err_mainlike_template_decl) << FD;
12422 FD->setInvalidDecl();
12423 }
12424}
12425
12426bool Sema::CheckForConstantInitializer(Expr *Init, unsigned DiagID) {
12427 // FIXME: Need strict checking. In C89, we need to check for
12428 // any assignment, increment, decrement, function-calls, or
12429 // commas outside of a sizeof. In C99, it's the same list,
12430 // except that the aforementioned are allowed in unevaluated
12431 // expressions. Everything else falls under the
12432 // "may accept other forms of constant expressions" exception.
12433 //
12434 // Regular C++ code will not end up here (exceptions: language extensions,
12435 // OpenCL C++ etc), so the constant expression rules there don't matter.
12436 if (Init->isValueDependent()) {
12437 assert(Init->containsErrors() &&
12438 "Dependent code should only occur in error-recovery path.");
12439 return true;
12440 }
12441 const Expr *Culprit;
12442 if (Init->isConstantInitializer(Ctx&: Context, ForRef: false, Culprit: &Culprit))
12443 return false;
12444 Diag(Loc: Culprit->getExprLoc(), DiagID) << Culprit->getSourceRange();
12445 return true;
12446}
12447
12448namespace {
12449 // Visits an initialization expression to see if OrigDecl is evaluated in
12450 // its own initialization and throws a warning if it does.
12451 class SelfReferenceChecker
12452 : public EvaluatedExprVisitor<SelfReferenceChecker> {
12453 Sema &S;
12454 Decl *OrigDecl;
12455 bool isRecordType;
12456 bool isPODType;
12457 bool isReferenceType;
12458
12459 bool isInitList;
12460 llvm::SmallVector<unsigned, 4> InitFieldIndex;
12461
12462 public:
12463 typedef EvaluatedExprVisitor<SelfReferenceChecker> Inherited;
12464
12465 SelfReferenceChecker(Sema &S, Decl *OrigDecl) : Inherited(S.Context),
12466 S(S), OrigDecl(OrigDecl) {
12467 isPODType = false;
12468 isRecordType = false;
12469 isReferenceType = false;
12470 isInitList = false;
12471 if (ValueDecl *VD = dyn_cast<ValueDecl>(Val: OrigDecl)) {
12472 isPODType = VD->getType().isPODType(Context: S.Context);
12473 isRecordType = VD->getType()->isRecordType();
12474 isReferenceType = VD->getType()->isReferenceType();
12475 }
12476 }
12477
12478 // For most expressions, just call the visitor. For initializer lists,
12479 // track the index of the field being initialized since fields are
12480 // initialized in order allowing use of previously initialized fields.
12481 void CheckExpr(Expr *E) {
12482 InitListExpr *InitList = dyn_cast<InitListExpr>(Val: E);
12483 if (!InitList) {
12484 Visit(S: E);
12485 return;
12486 }
12487
12488 // Track and increment the index here.
12489 isInitList = true;
12490 InitFieldIndex.push_back(Elt: 0);
12491 for (auto *Child : InitList->children()) {
12492 CheckExpr(E: cast<Expr>(Val: Child));
12493 ++InitFieldIndex.back();
12494 }
12495 InitFieldIndex.pop_back();
12496 }
12497
12498 // Returns true if MemberExpr is checked and no further checking is needed.
12499 // Returns false if additional checking is required.
12500 bool CheckInitListMemberExpr(MemberExpr *E, bool CheckReference) {
12501 llvm::SmallVector<FieldDecl*, 4> Fields;
12502 Expr *Base = E;
12503 bool ReferenceField = false;
12504
12505 // Get the field members used.
12506 while (MemberExpr *ME = dyn_cast<MemberExpr>(Val: Base)) {
12507 FieldDecl *FD = dyn_cast<FieldDecl>(Val: ME->getMemberDecl());
12508 if (!FD)
12509 return false;
12510 Fields.push_back(Elt: FD);
12511 if (FD->getType()->isReferenceType())
12512 ReferenceField = true;
12513 Base = ME->getBase()->IgnoreParenImpCasts();
12514 }
12515
12516 // Keep checking only if the base Decl is the same.
12517 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Val: Base);
12518 if (!DRE || DRE->getDecl() != OrigDecl)
12519 return false;
12520
12521 // A reference field can be bound to an unininitialized field.
12522 if (CheckReference && !ReferenceField)
12523 return true;
12524
12525 // Convert FieldDecls to their index number.
12526 llvm::SmallVector<unsigned, 4> UsedFieldIndex;
12527 for (const FieldDecl *I : llvm::reverse(C&: Fields))
12528 UsedFieldIndex.push_back(Elt: I->getFieldIndex());
12529
12530 // See if a warning is needed by checking the first difference in index
12531 // numbers. If field being used has index less than the field being
12532 // initialized, then the use is safe.
12533 for (auto UsedIter = UsedFieldIndex.begin(),
12534 UsedEnd = UsedFieldIndex.end(),
12535 OrigIter = InitFieldIndex.begin(),
12536 OrigEnd = InitFieldIndex.end();
12537 UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
12538 if (*UsedIter < *OrigIter)
12539 return true;
12540 if (*UsedIter > *OrigIter)
12541 break;
12542 }
12543
12544 // TODO: Add a different warning which will print the field names.
12545 HandleDeclRefExpr(DRE);
12546 return true;
12547 }
12548
12549 // For most expressions, the cast is directly above the DeclRefExpr.
12550 // For conditional operators, the cast can be outside the conditional
12551 // operator if both expressions are DeclRefExpr's.
12552 void HandleValue(Expr *E) {
12553 E = E->IgnoreParens();
12554 if (DeclRefExpr* DRE = dyn_cast<DeclRefExpr>(Val: E)) {
12555 HandleDeclRefExpr(DRE);
12556 return;
12557 }
12558
12559 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(Val: E)) {
12560 Visit(S: CO->getCond());
12561 HandleValue(E: CO->getTrueExpr());
12562 HandleValue(E: CO->getFalseExpr());
12563 return;
12564 }
12565
12566 if (BinaryConditionalOperator *BCO =
12567 dyn_cast<BinaryConditionalOperator>(Val: E)) {
12568 Visit(S: BCO->getCond());
12569 HandleValue(E: BCO->getFalseExpr());
12570 return;
12571 }
12572
12573 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(Val: E)) {
12574 if (Expr *SE = OVE->getSourceExpr())
12575 HandleValue(E: SE);
12576 return;
12577 }
12578
12579 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Val: E)) {
12580 if (BO->getOpcode() == BO_Comma) {
12581 Visit(S: BO->getLHS());
12582 HandleValue(E: BO->getRHS());
12583 return;
12584 }
12585 }
12586
12587 if (isa<MemberExpr>(Val: E)) {
12588 if (isInitList) {
12589 if (CheckInitListMemberExpr(E: cast<MemberExpr>(Val: E),
12590 CheckReference: false /*CheckReference*/))
12591 return;
12592 }
12593
12594 Expr *Base = E->IgnoreParenImpCasts();
12595 while (MemberExpr *ME = dyn_cast<MemberExpr>(Val: Base)) {
12596 // Check for static member variables and don't warn on them.
12597 if (!isa<FieldDecl>(Val: ME->getMemberDecl()))
12598 return;
12599 Base = ME->getBase()->IgnoreParenImpCasts();
12600 }
12601 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Val: Base))
12602 HandleDeclRefExpr(DRE);
12603 return;
12604 }
12605
12606 Visit(S: E);
12607 }
12608
12609 // Reference types not handled in HandleValue are handled here since all
12610 // uses of references are bad, not just r-value uses.
12611 void VisitDeclRefExpr(DeclRefExpr *E) {
12612 if (isReferenceType)
12613 HandleDeclRefExpr(DRE: E);
12614 }
12615
12616 void VisitImplicitCastExpr(ImplicitCastExpr *E) {
12617 if (E->getCastKind() == CK_LValueToRValue) {
12618 HandleValue(E: E->getSubExpr());
12619 return;
12620 }
12621
12622 Inherited::VisitImplicitCastExpr(S: E);
12623 }
12624
12625 void VisitMemberExpr(MemberExpr *E) {
12626 if (isInitList) {
12627 if (CheckInitListMemberExpr(E, CheckReference: true /*CheckReference*/))
12628 return;
12629 }
12630
12631 // Don't warn on arrays since they can be treated as pointers.
12632 if (E->getType()->canDecayToPointerType()) return;
12633
12634 // Warn when a non-static method call is followed by non-static member
12635 // field accesses, which is followed by a DeclRefExpr.
12636 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Val: E->getMemberDecl());
12637 bool Warn = (MD && !MD->isStatic());
12638 Expr *Base = E->getBase()->IgnoreParenImpCasts();
12639 while (MemberExpr *ME = dyn_cast<MemberExpr>(Val: Base)) {
12640 if (!isa<FieldDecl>(Val: ME->getMemberDecl()))
12641 Warn = false;
12642 Base = ME->getBase()->IgnoreParenImpCasts();
12643 }
12644
12645 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Val: Base)) {
12646 if (Warn)
12647 HandleDeclRefExpr(DRE);
12648 return;
12649 }
12650
12651 // The base of a MemberExpr is not a MemberExpr or a DeclRefExpr.
12652 // Visit that expression.
12653 Visit(S: Base);
12654 }
12655
12656 void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
12657 Expr *Callee = E->getCallee();
12658
12659 if (isa<UnresolvedLookupExpr>(Val: Callee))
12660 return Inherited::VisitCXXOperatorCallExpr(S: E);
12661
12662 Visit(S: Callee);
12663 for (auto Arg: E->arguments())
12664 HandleValue(E: Arg->IgnoreParenImpCasts());
12665 }
12666
12667 void VisitUnaryOperator(UnaryOperator *E) {
12668 // For POD record types, addresses of its own members are well-defined.
12669 if (E->getOpcode() == UO_AddrOf && isRecordType &&
12670 isa<MemberExpr>(Val: E->getSubExpr()->IgnoreParens())) {
12671 if (!isPODType)
12672 HandleValue(E: E->getSubExpr());
12673 return;
12674 }
12675
12676 if (E->isIncrementDecrementOp()) {
12677 HandleValue(E: E->getSubExpr());
12678 return;
12679 }
12680
12681 Inherited::VisitUnaryOperator(S: E);
12682 }
12683
12684 void VisitObjCMessageExpr(ObjCMessageExpr *E) {}
12685
12686 void VisitCXXConstructExpr(CXXConstructExpr *E) {
12687 if (E->getConstructor()->isCopyConstructor()) {
12688 Expr *ArgExpr = E->getArg(Arg: 0);
12689 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Val: ArgExpr))
12690 if (ILE->getNumInits() == 1)
12691 ArgExpr = ILE->getInit(Init: 0);
12692 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Val: ArgExpr))
12693 if (ICE->getCastKind() == CK_NoOp)
12694 ArgExpr = ICE->getSubExpr();
12695 HandleValue(E: ArgExpr);
12696 return;
12697 }
12698 Inherited::VisitCXXConstructExpr(S: E);
12699 }
12700
12701 void VisitCallExpr(CallExpr *E) {
12702 // Treat std::move as a use.
12703 if (E->isCallToStdMove()) {
12704 HandleValue(E: E->getArg(Arg: 0));
12705 return;
12706 }
12707
12708 Inherited::VisitCallExpr(CE: E);
12709 }
12710
12711 void VisitBinaryOperator(BinaryOperator *E) {
12712 if (E->isCompoundAssignmentOp()) {
12713 HandleValue(E: E->getLHS());
12714 Visit(S: E->getRHS());
12715 return;
12716 }
12717
12718 Inherited::VisitBinaryOperator(S: E);
12719 }
12720
12721 // A custom visitor for BinaryConditionalOperator is needed because the
12722 // regular visitor would check the condition and true expression separately
12723 // but both point to the same place giving duplicate diagnostics.
12724 void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) {
12725 Visit(S: E->getCond());
12726 Visit(S: E->getFalseExpr());
12727 }
12728
12729 void HandleDeclRefExpr(DeclRefExpr *DRE) {
12730 Decl* ReferenceDecl = DRE->getDecl();
12731 if (OrigDecl != ReferenceDecl) return;
12732 unsigned diag;
12733 if (isReferenceType) {
12734 diag = diag::warn_uninit_self_reference_in_reference_init;
12735 } else if (cast<VarDecl>(Val: OrigDecl)->isStaticLocal()) {
12736 diag = diag::warn_static_self_reference_in_init;
12737 } else if (isa<TranslationUnitDecl>(Val: OrigDecl->getDeclContext()) ||
12738 isa<NamespaceDecl>(Val: OrigDecl->getDeclContext()) ||
12739 DRE->getDecl()->getType()->isRecordType()) {
12740 diag = diag::warn_uninit_self_reference_in_init;
12741 } else {
12742 // Local variables will be handled by the CFG analysis.
12743 return;
12744 }
12745
12746 S.DiagRuntimeBehavior(Loc: DRE->getBeginLoc(), Statement: DRE,
12747 PD: S.PDiag(DiagID: diag)
12748 << DRE->getDecl() << OrigDecl->getLocation()
12749 << DRE->getSourceRange());
12750 }
12751 };
12752
12753 /// CheckSelfReference - Warns if OrigDecl is used in expression E.
12754 static void CheckSelfReference(Sema &S, Decl* OrigDecl, Expr *E,
12755 bool DirectInit) {
12756 // Parameters arguments are occassionially constructed with itself,
12757 // for instance, in recursive functions. Skip them.
12758 if (isa<ParmVarDecl>(Val: OrigDecl))
12759 return;
12760
12761 E = E->IgnoreParens();
12762
12763 // Skip checking T a = a where T is not a record or reference type.
12764 // Doing so is a way to silence uninitialized warnings.
12765 if (!DirectInit && !cast<VarDecl>(Val: OrigDecl)->getType()->isRecordType())
12766 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Val: E))
12767 if (ICE->getCastKind() == CK_LValueToRValue)
12768 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Val: ICE->getSubExpr()))
12769 if (DRE->getDecl() == OrigDecl)
12770 return;
12771
12772 SelfReferenceChecker(S, OrigDecl).CheckExpr(E);
12773 }
12774} // end anonymous namespace
12775
12776namespace {
12777 // Simple wrapper to add the name of a variable or (if no variable is
12778 // available) a DeclarationName into a diagnostic.
12779 struct VarDeclOrName {
12780 VarDecl *VDecl;
12781 DeclarationName Name;
12782
12783 friend const Sema::SemaDiagnosticBuilder &
12784 operator<<(const Sema::SemaDiagnosticBuilder &Diag, VarDeclOrName VN) {
12785 return VN.VDecl ? Diag << VN.VDecl : Diag << VN.Name;
12786 }
12787 };
12788} // end anonymous namespace
12789
12790QualType Sema::deduceVarTypeFromInitializer(VarDecl *VDecl,
12791 DeclarationName Name, QualType Type,
12792 TypeSourceInfo *TSI,
12793 SourceRange Range, bool DirectInit,
12794 Expr *Init) {
12795 bool IsInitCapture = !VDecl;
12796 assert((!VDecl || !VDecl->isInitCapture()) &&
12797 "init captures are expected to be deduced prior to initialization");
12798
12799 VarDeclOrName VN{.VDecl: VDecl, .Name: Name};
12800
12801 DeducedType *Deduced = Type->getContainedDeducedType();
12802 assert(Deduced && "deduceVarTypeFromInitializer for non-deduced type");
12803
12804 // Diagnose auto array declarations in C23, unless it's a supported extension.
12805 if (getLangOpts().C23 && Type->isArrayType() &&
12806 !isa_and_present<StringLiteral, InitListExpr>(Val: Init)) {
12807 Diag(Loc: Range.getBegin(), DiagID: diag::err_auto_not_allowed)
12808 << (int)Deduced->getContainedAutoType()->getKeyword()
12809 << /*in array decl*/ 23 << Range;
12810 return QualType();
12811 }
12812
12813 // C++11 [dcl.spec.auto]p3
12814 if (!Init) {
12815 assert(VDecl && "no init for init capture deduction?");
12816
12817 // Except for class argument deduction, and then for an initializing
12818 // declaration only, i.e. no static at class scope or extern.
12819 if (!isa<DeducedTemplateSpecializationType>(Val: Deduced) ||
12820 VDecl->hasExternalStorage() ||
12821 VDecl->isStaticDataMember()) {
12822 Diag(Loc: VDecl->getLocation(), DiagID: diag::err_auto_var_requires_init)
12823 << VDecl->getDeclName() << Type;
12824 return QualType();
12825 }
12826 }
12827
12828 ArrayRef<Expr*> DeduceInits;
12829 if (Init)
12830 DeduceInits = Init;
12831
12832 auto *PL = dyn_cast_if_present<ParenListExpr>(Val: Init);
12833 if (DirectInit && PL)
12834 DeduceInits = PL->exprs();
12835
12836 if (isa<DeducedTemplateSpecializationType>(Val: Deduced)) {
12837 assert(VDecl && "non-auto type for init capture deduction?");
12838 InitializedEntity Entity = InitializedEntity::InitializeVariable(Var: VDecl);
12839 InitializationKind Kind = InitializationKind::CreateForInit(
12840 Loc: VDecl->getLocation(), DirectInit, Init);
12841 // FIXME: Initialization should not be taking a mutable list of inits.
12842 SmallVector<Expr*, 8> InitsCopy(DeduceInits.begin(), DeduceInits.end());
12843 return DeduceTemplateSpecializationFromInitializer(TInfo: TSI, Entity, Kind,
12844 Init: InitsCopy);
12845 }
12846
12847 if (DirectInit) {
12848 if (auto *IL = dyn_cast<InitListExpr>(Val: Init))
12849 DeduceInits = IL->inits();
12850 }
12851
12852 // Deduction only works if we have exactly one source expression.
12853 if (DeduceInits.empty()) {
12854 // It isn't possible to write this directly, but it is possible to
12855 // end up in this situation with "auto x(some_pack...);"
12856 Diag(Loc: Init->getBeginLoc(), DiagID: IsInitCapture
12857 ? diag::err_init_capture_no_expression
12858 : diag::err_auto_var_init_no_expression)
12859 << VN << Type << Range;
12860 return QualType();
12861 }
12862
12863 if (DeduceInits.size() > 1) {
12864 Diag(Loc: DeduceInits[1]->getBeginLoc(),
12865 DiagID: IsInitCapture ? diag::err_init_capture_multiple_expressions
12866 : diag::err_auto_var_init_multiple_expressions)
12867 << VN << Type << Range;
12868 return QualType();
12869 }
12870
12871 Expr *DeduceInit = DeduceInits[0];
12872 if (DirectInit && isa<InitListExpr>(Val: DeduceInit)) {
12873 Diag(Loc: Init->getBeginLoc(), DiagID: IsInitCapture
12874 ? diag::err_init_capture_paren_braces
12875 : diag::err_auto_var_init_paren_braces)
12876 << isa<InitListExpr>(Val: Init) << VN << Type << Range;
12877 return QualType();
12878 }
12879
12880 // Expressions default to 'id' when we're in a debugger.
12881 bool DefaultedAnyToId = false;
12882 if (getLangOpts().DebuggerCastResultToId &&
12883 Init->getType() == Context.UnknownAnyTy && !IsInitCapture) {
12884 ExprResult Result = forceUnknownAnyToType(E: Init, ToType: Context.getObjCIdType());
12885 if (Result.isInvalid()) {
12886 return QualType();
12887 }
12888 Init = Result.get();
12889 DefaultedAnyToId = true;
12890 }
12891
12892 // C++ [dcl.decomp]p1:
12893 // If the assignment-expression [...] has array type A and no ref-qualifier
12894 // is present, e has type cv A
12895 if (VDecl && isa<DecompositionDecl>(Val: VDecl) &&
12896 Context.hasSameUnqualifiedType(T1: Type, T2: Context.getAutoDeductType()) &&
12897 DeduceInit->getType()->isConstantArrayType())
12898 return Context.getQualifiedType(T: DeduceInit->getType(),
12899 Qs: Type.getQualifiers());
12900
12901 QualType DeducedType;
12902 TemplateDeductionInfo Info(DeduceInit->getExprLoc());
12903 TemplateDeductionResult Result =
12904 DeduceAutoType(AutoTypeLoc: TSI->getTypeLoc(), Initializer: DeduceInit, Result&: DeducedType, Info);
12905 if (Result != TemplateDeductionResult::Success &&
12906 Result != TemplateDeductionResult::AlreadyDiagnosed) {
12907 if (!IsInitCapture)
12908 DiagnoseAutoDeductionFailure(VDecl, Init: DeduceInit);
12909 else if (isa<InitListExpr>(Val: Init))
12910 Diag(Loc: Range.getBegin(),
12911 DiagID: diag::err_init_capture_deduction_failure_from_init_list)
12912 << VN
12913 << (DeduceInit->getType().isNull() ? TSI->getType()
12914 : DeduceInit->getType())
12915 << DeduceInit->getSourceRange();
12916 else
12917 Diag(Loc: Range.getBegin(), DiagID: diag::err_init_capture_deduction_failure)
12918 << VN << TSI->getType()
12919 << (DeduceInit->getType().isNull() ? TSI->getType()
12920 : DeduceInit->getType())
12921 << DeduceInit->getSourceRange();
12922 }
12923
12924 // Warn if we deduced 'id'. 'auto' usually implies type-safety, but using
12925 // 'id' instead of a specific object type prevents most of our usual
12926 // checks.
12927 // We only want to warn outside of template instantiations, though:
12928 // inside a template, the 'id' could have come from a parameter.
12929 if (!inTemplateInstantiation() && !DefaultedAnyToId && !IsInitCapture &&
12930 !DeducedType.isNull() && DeducedType->isObjCIdType()) {
12931 SourceLocation Loc = TSI->getTypeLoc().getBeginLoc();
12932 Diag(Loc, DiagID: diag::warn_auto_var_is_id) << VN << Range;
12933 }
12934
12935 return DeducedType;
12936}
12937
12938bool Sema::DeduceVariableDeclarationType(VarDecl *VDecl, bool DirectInit,
12939 Expr *Init) {
12940 assert(!Init || !Init->containsErrors());
12941 QualType DeducedType = deduceVarTypeFromInitializer(
12942 VDecl, Name: VDecl->getDeclName(), Type: VDecl->getType(), TSI: VDecl->getTypeSourceInfo(),
12943 Range: VDecl->getSourceRange(), DirectInit, Init);
12944 if (DeducedType.isNull()) {
12945 VDecl->setInvalidDecl();
12946 return true;
12947 }
12948
12949 VDecl->setType(DeducedType);
12950 assert(VDecl->isLinkageValid());
12951
12952 // In ARC, infer lifetime.
12953 if (getLangOpts().ObjCAutoRefCount && ObjC().inferObjCARCLifetime(decl: VDecl))
12954 VDecl->setInvalidDecl();
12955
12956 if (getLangOpts().OpenCL)
12957 deduceOpenCLAddressSpace(Decl: VDecl);
12958
12959 // If this is a redeclaration, check that the type we just deduced matches
12960 // the previously declared type.
12961 if (VarDecl *Old = VDecl->getPreviousDecl()) {
12962 // We never need to merge the type, because we cannot form an incomplete
12963 // array of auto, nor deduce such a type.
12964 MergeVarDeclTypes(New: VDecl, Old, /*MergeTypeWithPrevious*/ MergeTypeWithOld: false);
12965 }
12966
12967 // Check the deduced type is valid for a variable declaration.
12968 CheckVariableDeclarationType(NewVD: VDecl);
12969 return VDecl->isInvalidDecl();
12970}
12971
12972void Sema::checkNonTrivialCUnionInInitializer(const Expr *Init,
12973 SourceLocation Loc) {
12974 if (auto *EWC = dyn_cast<ExprWithCleanups>(Val: Init))
12975 Init = EWC->getSubExpr();
12976
12977 if (auto *CE = dyn_cast<ConstantExpr>(Val: Init))
12978 Init = CE->getSubExpr();
12979
12980 QualType InitType = Init->getType();
12981 assert((InitType.hasNonTrivialToPrimitiveDefaultInitializeCUnion() ||
12982 InitType.hasNonTrivialToPrimitiveCopyCUnion()) &&
12983 "shouldn't be called if type doesn't have a non-trivial C struct");
12984 if (auto *ILE = dyn_cast<InitListExpr>(Val: Init)) {
12985 for (auto *I : ILE->inits()) {
12986 if (!I->getType().hasNonTrivialToPrimitiveDefaultInitializeCUnion() &&
12987 !I->getType().hasNonTrivialToPrimitiveCopyCUnion())
12988 continue;
12989 SourceLocation SL = I->getExprLoc();
12990 checkNonTrivialCUnionInInitializer(Init: I, Loc: SL.isValid() ? SL : Loc);
12991 }
12992 return;
12993 }
12994
12995 if (isa<ImplicitValueInitExpr>(Val: Init)) {
12996 if (InitType.hasNonTrivialToPrimitiveDefaultInitializeCUnion())
12997 checkNonTrivialCUnion(QT: InitType, Loc, UseContext: NTCUC_DefaultInitializedObject,
12998 NonTrivialKind: NTCUK_Init);
12999 } else {
13000 // Assume all other explicit initializers involving copying some existing
13001 // object.
13002 // TODO: ignore any explicit initializers where we can guarantee
13003 // copy-elision.
13004 if (InitType.hasNonTrivialToPrimitiveCopyCUnion())
13005 checkNonTrivialCUnion(QT: InitType, Loc, UseContext: NTCUC_CopyInit, NonTrivialKind: NTCUK_Copy);
13006 }
13007}
13008
13009namespace {
13010
13011bool shouldIgnoreForRecordTriviality(const FieldDecl *FD) {
13012 // Ignore unavailable fields. A field can be marked as unavailable explicitly
13013 // in the source code or implicitly by the compiler if it is in a union
13014 // defined in a system header and has non-trivial ObjC ownership
13015 // qualifications. We don't want those fields to participate in determining
13016 // whether the containing union is non-trivial.
13017 return FD->hasAttr<UnavailableAttr>();
13018}
13019
13020struct DiagNonTrivalCUnionDefaultInitializeVisitor
13021 : DefaultInitializedTypeVisitor<DiagNonTrivalCUnionDefaultInitializeVisitor,
13022 void> {
13023 using Super =
13024 DefaultInitializedTypeVisitor<DiagNonTrivalCUnionDefaultInitializeVisitor,
13025 void>;
13026
13027 DiagNonTrivalCUnionDefaultInitializeVisitor(
13028 QualType OrigTy, SourceLocation OrigLoc,
13029 Sema::NonTrivialCUnionContext UseContext, Sema &S)
13030 : OrigTy(OrigTy), OrigLoc(OrigLoc), UseContext(UseContext), S(S) {}
13031
13032 void visitWithKind(QualType::PrimitiveDefaultInitializeKind PDIK, QualType QT,
13033 const FieldDecl *FD, bool InNonTrivialUnion) {
13034 if (const auto *AT = S.Context.getAsArrayType(T: QT))
13035 return this->asDerived().visit(FT: S.Context.getBaseElementType(VAT: AT), Args&: FD,
13036 Args&: InNonTrivialUnion);
13037 return Super::visitWithKind(PDIK, FT: QT, Args&: FD, Args&: InNonTrivialUnion);
13038 }
13039
13040 void visitARCStrong(QualType QT, const FieldDecl *FD,
13041 bool InNonTrivialUnion) {
13042 if (InNonTrivialUnion)
13043 S.Diag(Loc: FD->getLocation(), DiagID: diag::note_non_trivial_c_union)
13044 << 1 << 0 << QT << FD->getName();
13045 }
13046
13047 void visitARCWeak(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
13048 if (InNonTrivialUnion)
13049 S.Diag(Loc: FD->getLocation(), DiagID: diag::note_non_trivial_c_union)
13050 << 1 << 0 << QT << FD->getName();
13051 }
13052
13053 void visitStruct(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
13054 const RecordDecl *RD = QT->castAs<RecordType>()->getDecl();
13055 if (RD->isUnion()) {
13056 if (OrigLoc.isValid()) {
13057 bool IsUnion = false;
13058 if (auto *OrigRD = OrigTy->getAsRecordDecl())
13059 IsUnion = OrigRD->isUnion();
13060 S.Diag(Loc: OrigLoc, DiagID: diag::err_non_trivial_c_union_in_invalid_context)
13061 << 0 << OrigTy << IsUnion << UseContext;
13062 // Reset OrigLoc so that this diagnostic is emitted only once.
13063 OrigLoc = SourceLocation();
13064 }
13065 InNonTrivialUnion = true;
13066 }
13067
13068 if (InNonTrivialUnion)
13069 S.Diag(Loc: RD->getLocation(), DiagID: diag::note_non_trivial_c_union)
13070 << 0 << 0 << QT.getUnqualifiedType() << "";
13071
13072 for (const FieldDecl *FD : RD->fields())
13073 if (!shouldIgnoreForRecordTriviality(FD))
13074 asDerived().visit(FT: FD->getType(), Args&: FD, Args&: InNonTrivialUnion);
13075 }
13076
13077 void visitTrivial(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {}
13078
13079 // The non-trivial C union type or the struct/union type that contains a
13080 // non-trivial C union.
13081 QualType OrigTy;
13082 SourceLocation OrigLoc;
13083 Sema::NonTrivialCUnionContext UseContext;
13084 Sema &S;
13085};
13086
13087struct DiagNonTrivalCUnionDestructedTypeVisitor
13088 : DestructedTypeVisitor<DiagNonTrivalCUnionDestructedTypeVisitor, void> {
13089 using Super =
13090 DestructedTypeVisitor<DiagNonTrivalCUnionDestructedTypeVisitor, void>;
13091
13092 DiagNonTrivalCUnionDestructedTypeVisitor(
13093 QualType OrigTy, SourceLocation OrigLoc,
13094 Sema::NonTrivialCUnionContext UseContext, Sema &S)
13095 : OrigTy(OrigTy), OrigLoc(OrigLoc), UseContext(UseContext), S(S) {}
13096
13097 void visitWithKind(QualType::DestructionKind DK, QualType QT,
13098 const FieldDecl *FD, bool InNonTrivialUnion) {
13099 if (const auto *AT = S.Context.getAsArrayType(T: QT))
13100 return this->asDerived().visit(FT: S.Context.getBaseElementType(VAT: AT), Args&: FD,
13101 Args&: InNonTrivialUnion);
13102 return Super::visitWithKind(DK, FT: QT, Args&: FD, Args&: InNonTrivialUnion);
13103 }
13104
13105 void visitARCStrong(QualType QT, const FieldDecl *FD,
13106 bool InNonTrivialUnion) {
13107 if (InNonTrivialUnion)
13108 S.Diag(Loc: FD->getLocation(), DiagID: diag::note_non_trivial_c_union)
13109 << 1 << 1 << QT << FD->getName();
13110 }
13111
13112 void visitARCWeak(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
13113 if (InNonTrivialUnion)
13114 S.Diag(Loc: FD->getLocation(), DiagID: diag::note_non_trivial_c_union)
13115 << 1 << 1 << QT << FD->getName();
13116 }
13117
13118 void visitStruct(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
13119 const RecordDecl *RD = QT->castAs<RecordType>()->getDecl();
13120 if (RD->isUnion()) {
13121 if (OrigLoc.isValid()) {
13122 bool IsUnion = false;
13123 if (auto *OrigRD = OrigTy->getAsRecordDecl())
13124 IsUnion = OrigRD->isUnion();
13125 S.Diag(Loc: OrigLoc, DiagID: diag::err_non_trivial_c_union_in_invalid_context)
13126 << 1 << OrigTy << IsUnion << UseContext;
13127 // Reset OrigLoc so that this diagnostic is emitted only once.
13128 OrigLoc = SourceLocation();
13129 }
13130 InNonTrivialUnion = true;
13131 }
13132
13133 if (InNonTrivialUnion)
13134 S.Diag(Loc: RD->getLocation(), DiagID: diag::note_non_trivial_c_union)
13135 << 0 << 1 << QT.getUnqualifiedType() << "";
13136
13137 for (const FieldDecl *FD : RD->fields())
13138 if (!shouldIgnoreForRecordTriviality(FD))
13139 asDerived().visit(FT: FD->getType(), Args&: FD, Args&: InNonTrivialUnion);
13140 }
13141
13142 void visitTrivial(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {}
13143 void visitCXXDestructor(QualType QT, const FieldDecl *FD,
13144 bool InNonTrivialUnion) {}
13145
13146 // The non-trivial C union type or the struct/union type that contains a
13147 // non-trivial C union.
13148 QualType OrigTy;
13149 SourceLocation OrigLoc;
13150 Sema::NonTrivialCUnionContext UseContext;
13151 Sema &S;
13152};
13153
13154struct DiagNonTrivalCUnionCopyVisitor
13155 : CopiedTypeVisitor<DiagNonTrivalCUnionCopyVisitor, false, void> {
13156 using Super = CopiedTypeVisitor<DiagNonTrivalCUnionCopyVisitor, false, void>;
13157
13158 DiagNonTrivalCUnionCopyVisitor(QualType OrigTy, SourceLocation OrigLoc,
13159 Sema::NonTrivialCUnionContext UseContext,
13160 Sema &S)
13161 : OrigTy(OrigTy), OrigLoc(OrigLoc), UseContext(UseContext), S(S) {}
13162
13163 void visitWithKind(QualType::PrimitiveCopyKind PCK, QualType QT,
13164 const FieldDecl *FD, bool InNonTrivialUnion) {
13165 if (const auto *AT = S.Context.getAsArrayType(T: QT))
13166 return this->asDerived().visit(FT: S.Context.getBaseElementType(VAT: AT), Args&: FD,
13167 Args&: InNonTrivialUnion);
13168 return Super::visitWithKind(PCK, FT: QT, Args&: FD, Args&: InNonTrivialUnion);
13169 }
13170
13171 void visitARCStrong(QualType QT, const FieldDecl *FD,
13172 bool InNonTrivialUnion) {
13173 if (InNonTrivialUnion)
13174 S.Diag(Loc: FD->getLocation(), DiagID: diag::note_non_trivial_c_union)
13175 << 1 << 2 << QT << FD->getName();
13176 }
13177
13178 void visitARCWeak(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
13179 if (InNonTrivialUnion)
13180 S.Diag(Loc: FD->getLocation(), DiagID: diag::note_non_trivial_c_union)
13181 << 1 << 2 << QT << FD->getName();
13182 }
13183
13184 void visitStruct(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {
13185 const RecordDecl *RD = QT->castAs<RecordType>()->getDecl();
13186 if (RD->isUnion()) {
13187 if (OrigLoc.isValid()) {
13188 bool IsUnion = false;
13189 if (auto *OrigRD = OrigTy->getAsRecordDecl())
13190 IsUnion = OrigRD->isUnion();
13191 S.Diag(Loc: OrigLoc, DiagID: diag::err_non_trivial_c_union_in_invalid_context)
13192 << 2 << OrigTy << IsUnion << UseContext;
13193 // Reset OrigLoc so that this diagnostic is emitted only once.
13194 OrigLoc = SourceLocation();
13195 }
13196 InNonTrivialUnion = true;
13197 }
13198
13199 if (InNonTrivialUnion)
13200 S.Diag(Loc: RD->getLocation(), DiagID: diag::note_non_trivial_c_union)
13201 << 0 << 2 << QT.getUnqualifiedType() << "";
13202
13203 for (const FieldDecl *FD : RD->fields())
13204 if (!shouldIgnoreForRecordTriviality(FD))
13205 asDerived().visit(FT: FD->getType(), Args&: FD, Args&: InNonTrivialUnion);
13206 }
13207
13208 void preVisit(QualType::PrimitiveCopyKind PCK, QualType QT,
13209 const FieldDecl *FD, bool InNonTrivialUnion) {}
13210 void visitTrivial(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {}
13211 void visitVolatileTrivial(QualType QT, const FieldDecl *FD,
13212 bool InNonTrivialUnion) {}
13213
13214 // The non-trivial C union type or the struct/union type that contains a
13215 // non-trivial C union.
13216 QualType OrigTy;
13217 SourceLocation OrigLoc;
13218 Sema::NonTrivialCUnionContext UseContext;
13219 Sema &S;
13220};
13221
13222} // namespace
13223
13224void Sema::checkNonTrivialCUnion(QualType QT, SourceLocation Loc,
13225 NonTrivialCUnionContext UseContext,
13226 unsigned NonTrivialKind) {
13227 assert((QT.hasNonTrivialToPrimitiveDefaultInitializeCUnion() ||
13228 QT.hasNonTrivialToPrimitiveDestructCUnion() ||
13229 QT.hasNonTrivialToPrimitiveCopyCUnion()) &&
13230 "shouldn't be called if type doesn't have a non-trivial C union");
13231
13232 if ((NonTrivialKind & NTCUK_Init) &&
13233 QT.hasNonTrivialToPrimitiveDefaultInitializeCUnion())
13234 DiagNonTrivalCUnionDefaultInitializeVisitor(QT, Loc, UseContext, *this)
13235 .visit(FT: QT, Args: nullptr, Args: false);
13236 if ((NonTrivialKind & NTCUK_Destruct) &&
13237 QT.hasNonTrivialToPrimitiveDestructCUnion())
13238 DiagNonTrivalCUnionDestructedTypeVisitor(QT, Loc, UseContext, *this)
13239 .visit(FT: QT, Args: nullptr, Args: false);
13240 if ((NonTrivialKind & NTCUK_Copy) && QT.hasNonTrivialToPrimitiveCopyCUnion())
13241 DiagNonTrivalCUnionCopyVisitor(QT, Loc, UseContext, *this)
13242 .visit(FT: QT, Args: nullptr, Args: false);
13243}
13244
13245void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
13246 // If there is no declaration, there was an error parsing it. Just ignore
13247 // the initializer.
13248 if (!RealDecl) {
13249 CorrectDelayedTyposInExpr(E: Init, InitDecl: dyn_cast_or_null<VarDecl>(Val: RealDecl));
13250 return;
13251 }
13252
13253 if (auto *Method = dyn_cast<CXXMethodDecl>(Val: RealDecl)) {
13254 if (!Method->isInvalidDecl()) {
13255 // Pure-specifiers are handled in ActOnPureSpecifier.
13256 Diag(Loc: Method->getLocation(), DiagID: diag::err_member_function_initialization)
13257 << Method->getDeclName() << Init->getSourceRange();
13258 Method->setInvalidDecl();
13259 }
13260 return;
13261 }
13262
13263 VarDecl *VDecl = dyn_cast<VarDecl>(Val: RealDecl);
13264 if (!VDecl) {
13265 assert(!isa<FieldDecl>(RealDecl) && "field init shouldn't get here");
13266 Diag(Loc: RealDecl->getLocation(), DiagID: diag::err_illegal_initializer);
13267 RealDecl->setInvalidDecl();
13268 return;
13269 }
13270
13271 if (VDecl->isInvalidDecl()) {
13272 ExprResult Res = CorrectDelayedTyposInExpr(E: Init, InitDecl: VDecl);
13273 SmallVector<Expr *> SubExprs;
13274 if (Res.isUsable())
13275 SubExprs.push_back(Elt: Res.get());
13276 ExprResult Recovery =
13277 CreateRecoveryExpr(Begin: Init->getBeginLoc(), End: Init->getEndLoc(), SubExprs);
13278 if (Expr *E = Recovery.get())
13279 VDecl->setInit(E);
13280 return;
13281 }
13282
13283 // WebAssembly tables can't be used to initialise a variable.
13284 if (Init && !Init->getType().isNull() &&
13285 Init->getType()->isWebAssemblyTableType()) {
13286 Diag(Loc: Init->getExprLoc(), DiagID: diag::err_wasm_table_art) << 0;
13287 VDecl->setInvalidDecl();
13288 return;
13289 }
13290
13291 // C++11 [decl.spec.auto]p6. Deduce the type which 'auto' stands in for.
13292 if (VDecl->getType()->isUndeducedType()) {
13293 // Attempt typo correction early so that the type of the init expression can
13294 // be deduced based on the chosen correction if the original init contains a
13295 // TypoExpr.
13296 ExprResult Res = CorrectDelayedTyposInExpr(E: Init, InitDecl: VDecl);
13297 if (!Res.isUsable()) {
13298 // There are unresolved typos in Init, just drop them.
13299 // FIXME: improve the recovery strategy to preserve the Init.
13300 RealDecl->setInvalidDecl();
13301 return;
13302 }
13303 if (Res.get()->containsErrors()) {
13304 // Invalidate the decl as we don't know the type for recovery-expr yet.
13305 RealDecl->setInvalidDecl();
13306 VDecl->setInit(Res.get());
13307 return;
13308 }
13309 Init = Res.get();
13310
13311 if (DeduceVariableDeclarationType(VDecl, DirectInit, Init))
13312 return;
13313 }
13314
13315 // dllimport cannot be used on variable definitions.
13316 if (VDecl->hasAttr<DLLImportAttr>() && !VDecl->isStaticDataMember()) {
13317 Diag(Loc: VDecl->getLocation(), DiagID: diag::err_attribute_dllimport_data_definition);
13318 VDecl->setInvalidDecl();
13319 return;
13320 }
13321
13322 // C99 6.7.8p5. If the declaration of an identifier has block scope, and
13323 // the identifier has external or internal linkage, the declaration shall
13324 // have no initializer for the identifier.
13325 // C++14 [dcl.init]p5 is the same restriction for C++.
13326 if (VDecl->isLocalVarDecl() && VDecl->hasExternalStorage()) {
13327 Diag(Loc: VDecl->getLocation(), DiagID: diag::err_block_extern_cant_init);
13328 VDecl->setInvalidDecl();
13329 return;
13330 }
13331
13332 if (!VDecl->getType()->isDependentType()) {
13333 // A definition must end up with a complete type, which means it must be
13334 // complete with the restriction that an array type might be completed by
13335 // the initializer; note that later code assumes this restriction.
13336 QualType BaseDeclType = VDecl->getType();
13337 if (const ArrayType *Array = Context.getAsIncompleteArrayType(T: BaseDeclType))
13338 BaseDeclType = Array->getElementType();
13339 if (RequireCompleteType(Loc: VDecl->getLocation(), T: BaseDeclType,
13340 DiagID: diag::err_typecheck_decl_incomplete_type)) {
13341 RealDecl->setInvalidDecl();
13342 return;
13343 }
13344
13345 // The variable can not have an abstract class type.
13346 if (RequireNonAbstractType(Loc: VDecl->getLocation(), T: VDecl->getType(),
13347 DiagID: diag::err_abstract_type_in_decl,
13348 Args: AbstractVariableType))
13349 VDecl->setInvalidDecl();
13350 }
13351
13352 // C++ [module.import/6] external definitions are not permitted in header
13353 // units.
13354 if (getLangOpts().CPlusPlusModules && currentModuleIsHeaderUnit() &&
13355 !VDecl->isInvalidDecl() && VDecl->isThisDeclarationADefinition() &&
13356 VDecl->getFormalLinkage() == Linkage::External && !VDecl->isInline() &&
13357 !VDecl->isTemplated() && !isa<VarTemplateSpecializationDecl>(Val: VDecl) &&
13358 !VDecl->getInstantiatedFromStaticDataMember()) {
13359 Diag(Loc: VDecl->getLocation(), DiagID: diag::err_extern_def_in_header_unit);
13360 VDecl->setInvalidDecl();
13361 }
13362
13363 // If adding the initializer will turn this declaration into a definition,
13364 // and we already have a definition for this variable, diagnose or otherwise
13365 // handle the situation.
13366 if (VarDecl *Def = VDecl->getDefinition())
13367 if (Def != VDecl &&
13368 (!VDecl->isStaticDataMember() || VDecl->isOutOfLine()) &&
13369 !VDecl->isThisDeclarationADemotedDefinition() &&
13370 checkVarDeclRedefinition(Old: Def, New: VDecl))
13371 return;
13372
13373 if (getLangOpts().CPlusPlus) {
13374 // C++ [class.static.data]p4
13375 // If a static data member is of const integral or const
13376 // enumeration type, its declaration in the class definition can
13377 // specify a constant-initializer which shall be an integral
13378 // constant expression (5.19). In that case, the member can appear
13379 // in integral constant expressions. The member shall still be
13380 // defined in a namespace scope if it is used in the program and the
13381 // namespace scope definition shall not contain an initializer.
13382 //
13383 // We already performed a redefinition check above, but for static
13384 // data members we also need to check whether there was an in-class
13385 // declaration with an initializer.
13386 if (VDecl->isStaticDataMember() && VDecl->getCanonicalDecl()->hasInit()) {
13387 Diag(Loc: Init->getExprLoc(), DiagID: diag::err_static_data_member_reinitialization)
13388 << VDecl->getDeclName();
13389 Diag(Loc: VDecl->getCanonicalDecl()->getInit()->getExprLoc(),
13390 DiagID: diag::note_previous_initializer)
13391 << 0;
13392 return;
13393 }
13394
13395 if (VDecl->hasLocalStorage())
13396 setFunctionHasBranchProtectedScope();
13397
13398 if (DiagnoseUnexpandedParameterPack(E: Init, UPPC: UPPC_Initializer)) {
13399 VDecl->setInvalidDecl();
13400 return;
13401 }
13402 }
13403
13404 // OpenCL 1.1 6.5.2: "Variables allocated in the __local address space inside
13405 // a kernel function cannot be initialized."
13406 if (VDecl->getType().getAddressSpace() == LangAS::opencl_local) {
13407 Diag(Loc: VDecl->getLocation(), DiagID: diag::err_local_cant_init);
13408 VDecl->setInvalidDecl();
13409 return;
13410 }
13411
13412 // The LoaderUninitialized attribute acts as a definition (of undef).
13413 if (VDecl->hasAttr<LoaderUninitializedAttr>()) {
13414 Diag(Loc: VDecl->getLocation(), DiagID: diag::err_loader_uninitialized_cant_init);
13415 VDecl->setInvalidDecl();
13416 return;
13417 }
13418
13419 // Get the decls type and save a reference for later, since
13420 // CheckInitializerTypes may change it.
13421 QualType DclT = VDecl->getType(), SavT = DclT;
13422
13423 // Expressions default to 'id' when we're in a debugger
13424 // and we are assigning it to a variable of Objective-C pointer type.
13425 if (getLangOpts().DebuggerCastResultToId && DclT->isObjCObjectPointerType() &&
13426 Init->getType() == Context.UnknownAnyTy) {
13427 ExprResult Result = forceUnknownAnyToType(E: Init, ToType: Context.getObjCIdType());
13428 if (Result.isInvalid()) {
13429 VDecl->setInvalidDecl();
13430 return;
13431 }
13432 Init = Result.get();
13433 }
13434
13435 // Perform the initialization.
13436 ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Val: Init);
13437 bool IsParenListInit = false;
13438 if (!VDecl->isInvalidDecl()) {
13439 InitializedEntity Entity = InitializedEntity::InitializeVariable(Var: VDecl);
13440 InitializationKind Kind = InitializationKind::CreateForInit(
13441 Loc: VDecl->getLocation(), DirectInit, Init);
13442
13443 MultiExprArg Args = Init;
13444 if (CXXDirectInit)
13445 Args = MultiExprArg(CXXDirectInit->getExprs(),
13446 CXXDirectInit->getNumExprs());
13447
13448 // Try to correct any TypoExprs in the initialization arguments.
13449 for (size_t Idx = 0; Idx < Args.size(); ++Idx) {
13450 ExprResult Res = CorrectDelayedTyposInExpr(
13451 E: Args[Idx], InitDecl: VDecl, /*RecoverUncorrectedTypos=*/true,
13452 Filter: [this, Entity, Kind](Expr *E) {
13453 InitializationSequence Init(*this, Entity, Kind, MultiExprArg(E));
13454 return Init.Failed() ? ExprError() : E;
13455 });
13456 if (Res.isInvalid()) {
13457 VDecl->setInvalidDecl();
13458 } else if (Res.get() != Args[Idx]) {
13459 Args[Idx] = Res.get();
13460 }
13461 }
13462 if (VDecl->isInvalidDecl())
13463 return;
13464
13465 InitializationSequence InitSeq(*this, Entity, Kind, Args,
13466 /*TopLevelOfInitList=*/false,
13467 /*TreatUnavailableAsInvalid=*/false);
13468 ExprResult Result = InitSeq.Perform(S&: *this, Entity, Kind, Args, ResultType: &DclT);
13469 if (Result.isInvalid()) {
13470 // If the provided initializer fails to initialize the var decl,
13471 // we attach a recovery expr for better recovery.
13472 auto RecoveryExpr =
13473 CreateRecoveryExpr(Begin: Init->getBeginLoc(), End: Init->getEndLoc(), SubExprs: Args);
13474 if (RecoveryExpr.get())
13475 VDecl->setInit(RecoveryExpr.get());
13476 // In general, for error recovery purposes, the initializer doesn't play
13477 // part in the valid bit of the declaration. There are a few exceptions:
13478 // 1) if the var decl has a deduced auto type, and the type cannot be
13479 // deduced by an invalid initializer;
13480 // 2) if the var decl is a decomposition decl with a non-deduced type,
13481 // and the initialization fails (e.g. `int [a] = {1, 2};`);
13482 // Case 1) was already handled elsewhere.
13483 if (isa<DecompositionDecl>(Val: VDecl)) // Case 2)
13484 VDecl->setInvalidDecl();
13485 return;
13486 }
13487
13488 Init = Result.getAs<Expr>();
13489 IsParenListInit = !InitSeq.steps().empty() &&
13490 InitSeq.step_begin()->Kind ==
13491 InitializationSequence::SK_ParenthesizedListInit;
13492 QualType VDeclType = VDecl->getType();
13493 if (Init && !Init->getType().isNull() &&
13494 !Init->getType()->isDependentType() && !VDeclType->isDependentType() &&
13495 Context.getAsIncompleteArrayType(T: VDeclType) &&
13496 Context.getAsIncompleteArrayType(T: Init->getType())) {
13497 // Bail out if it is not possible to deduce array size from the
13498 // initializer.
13499 Diag(Loc: VDecl->getLocation(), DiagID: diag::err_typecheck_decl_incomplete_type)
13500 << VDeclType;
13501 VDecl->setInvalidDecl();
13502 return;
13503 }
13504 }
13505
13506 // Check for self-references within variable initializers.
13507 // Variables declared within a function/method body (except for references)
13508 // are handled by a dataflow analysis.
13509 // This is undefined behavior in C++, but valid in C.
13510 if (getLangOpts().CPlusPlus)
13511 if (!VDecl->hasLocalStorage() || VDecl->getType()->isRecordType() ||
13512 VDecl->getType()->isReferenceType())
13513 CheckSelfReference(S&: *this, OrigDecl: RealDecl, E: Init, DirectInit);
13514
13515 // If the type changed, it means we had an incomplete type that was
13516 // completed by the initializer. For example:
13517 // int ary[] = { 1, 3, 5 };
13518 // "ary" transitions from an IncompleteArrayType to a ConstantArrayType.
13519 if (!VDecl->isInvalidDecl() && (DclT != SavT))
13520 VDecl->setType(DclT);
13521
13522 if (!VDecl->isInvalidDecl()) {
13523 checkUnsafeAssigns(Loc: VDecl->getLocation(), LHS: VDecl->getType(), RHS: Init);
13524
13525 if (VDecl->hasAttr<BlocksAttr>())
13526 ObjC().checkRetainCycles(Var: VDecl, Init);
13527
13528 // It is safe to assign a weak reference into a strong variable.
13529 // Although this code can still have problems:
13530 // id x = self.weakProp;
13531 // id y = self.weakProp;
13532 // we do not warn to warn spuriously when 'x' and 'y' are on separate
13533 // paths through the function. This should be revisited if
13534 // -Wrepeated-use-of-weak is made flow-sensitive.
13535 if (FunctionScopeInfo *FSI = getCurFunction())
13536 if ((VDecl->getType().getObjCLifetime() == Qualifiers::OCL_Strong ||
13537 VDecl->getType().isNonWeakInMRRWithObjCWeak(Context)) &&
13538 !Diags.isIgnored(DiagID: diag::warn_arc_repeated_use_of_weak,
13539 Loc: Init->getBeginLoc()))
13540 FSI->markSafeWeakUse(E: Init);
13541 }
13542
13543 // The initialization is usually a full-expression.
13544 //
13545 // FIXME: If this is a braced initialization of an aggregate, it is not
13546 // an expression, and each individual field initializer is a separate
13547 // full-expression. For instance, in:
13548 //
13549 // struct Temp { ~Temp(); };
13550 // struct S { S(Temp); };
13551 // struct T { S a, b; } t = { Temp(), Temp() }
13552 //
13553 // we should destroy the first Temp before constructing the second.
13554 ExprResult Result =
13555 ActOnFinishFullExpr(Expr: Init, CC: VDecl->getLocation(),
13556 /*DiscardedValue*/ false, IsConstexpr: VDecl->isConstexpr());
13557 if (Result.isInvalid()) {
13558 VDecl->setInvalidDecl();
13559 return;
13560 }
13561 Init = Result.get();
13562
13563 // Attach the initializer to the decl.
13564 VDecl->setInit(Init);
13565
13566 if (VDecl->isLocalVarDecl()) {
13567 // Don't check the initializer if the declaration is malformed.
13568 if (VDecl->isInvalidDecl()) {
13569 // do nothing
13570
13571 // OpenCL v1.2 s6.5.3: __constant locals must be constant-initialized.
13572 // This is true even in C++ for OpenCL.
13573 } else if (VDecl->getType().getAddressSpace() == LangAS::opencl_constant) {
13574 CheckForConstantInitializer(Init);
13575
13576 // Otherwise, C++ does not restrict the initializer.
13577 } else if (getLangOpts().CPlusPlus) {
13578 // do nothing
13579
13580 // C99 6.7.8p4: All the expressions in an initializer for an object that has
13581 // static storage duration shall be constant expressions or string literals.
13582 } else if (VDecl->getStorageClass() == SC_Static) {
13583 CheckForConstantInitializer(Init);
13584
13585 // C89 is stricter than C99 for aggregate initializers.
13586 // C89 6.5.7p3: All the expressions [...] in an initializer list
13587 // for an object that has aggregate or union type shall be
13588 // constant expressions.
13589 } else if (!getLangOpts().C99 && VDecl->getType()->isAggregateType() &&
13590 isa<InitListExpr>(Val: Init)) {
13591 CheckForConstantInitializer(Init, DiagID: diag::ext_aggregate_init_not_constant);
13592 }
13593
13594 if (auto *E = dyn_cast<ExprWithCleanups>(Val: Init))
13595 if (auto *BE = dyn_cast<BlockExpr>(Val: E->getSubExpr()->IgnoreParens()))
13596 if (VDecl->hasLocalStorage())
13597 BE->getBlockDecl()->setCanAvoidCopyToHeap();
13598 } else if (VDecl->isStaticDataMember() && !VDecl->isInline() &&
13599 VDecl->getLexicalDeclContext()->isRecord()) {
13600 // This is an in-class initialization for a static data member, e.g.,
13601 //
13602 // struct S {
13603 // static const int value = 17;
13604 // };
13605
13606 // C++ [class.mem]p4:
13607 // A member-declarator can contain a constant-initializer only
13608 // if it declares a static member (9.4) of const integral or
13609 // const enumeration type, see 9.4.2.
13610 //
13611 // C++11 [class.static.data]p3:
13612 // If a non-volatile non-inline const static data member is of integral
13613 // or enumeration type, its declaration in the class definition can
13614 // specify a brace-or-equal-initializer in which every initializer-clause
13615 // that is an assignment-expression is a constant expression. A static
13616 // data member of literal type can be declared in the class definition
13617 // with the constexpr specifier; if so, its declaration shall specify a
13618 // brace-or-equal-initializer in which every initializer-clause that is
13619 // an assignment-expression is a constant expression.
13620
13621 // Do nothing on dependent types.
13622 if (DclT->isDependentType()) {
13623
13624 // Allow any 'static constexpr' members, whether or not they are of literal
13625 // type. We separately check that every constexpr variable is of literal
13626 // type.
13627 } else if (VDecl->isConstexpr()) {
13628
13629 // Require constness.
13630 } else if (!DclT.isConstQualified()) {
13631 Diag(Loc: VDecl->getLocation(), DiagID: diag::err_in_class_initializer_non_const)
13632 << Init->getSourceRange();
13633 VDecl->setInvalidDecl();
13634
13635 // We allow integer constant expressions in all cases.
13636 } else if (DclT->isIntegralOrEnumerationType()) {
13637 // Check whether the expression is a constant expression.
13638 SourceLocation Loc;
13639 if (getLangOpts().CPlusPlus11 && DclT.isVolatileQualified())
13640 // In C++11, a non-constexpr const static data member with an
13641 // in-class initializer cannot be volatile.
13642 Diag(Loc: VDecl->getLocation(), DiagID: diag::err_in_class_initializer_volatile);
13643 else if (Init->isValueDependent())
13644 ; // Nothing to check.
13645 else if (Init->isIntegerConstantExpr(Ctx: Context, Loc: &Loc))
13646 ; // Ok, it's an ICE!
13647 else if (Init->getType()->isScopedEnumeralType() &&
13648 Init->isCXX11ConstantExpr(Ctx: Context))
13649 ; // Ok, it is a scoped-enum constant expression.
13650 else if (Init->isEvaluatable(Ctx: Context)) {
13651 // If we can constant fold the initializer through heroics, accept it,
13652 // but report this as a use of an extension for -pedantic.
13653 Diag(Loc, DiagID: diag::ext_in_class_initializer_non_constant)
13654 << Init->getSourceRange();
13655 } else {
13656 // Otherwise, this is some crazy unknown case. Report the issue at the
13657 // location provided by the isIntegerConstantExpr failed check.
13658 Diag(Loc, DiagID: diag::err_in_class_initializer_non_constant)
13659 << Init->getSourceRange();
13660 VDecl->setInvalidDecl();
13661 }
13662
13663 // We allow foldable floating-point constants as an extension.
13664 } else if (DclT->isFloatingType()) { // also permits complex, which is ok
13665 // In C++98, this is a GNU extension. In C++11, it is not, but we support
13666 // it anyway and provide a fixit to add the 'constexpr'.
13667 if (getLangOpts().CPlusPlus11) {
13668 Diag(Loc: VDecl->getLocation(),
13669 DiagID: diag::ext_in_class_initializer_float_type_cxx11)
13670 << DclT << Init->getSourceRange();
13671 Diag(Loc: VDecl->getBeginLoc(),
13672 DiagID: diag::note_in_class_initializer_float_type_cxx11)
13673 << FixItHint::CreateInsertion(InsertionLoc: VDecl->getBeginLoc(), Code: "constexpr ");
13674 } else {
13675 Diag(Loc: VDecl->getLocation(), DiagID: diag::ext_in_class_initializer_float_type)
13676 << DclT << Init->getSourceRange();
13677
13678 if (!Init->isValueDependent() && !Init->isEvaluatable(Ctx: Context)) {
13679 Diag(Loc: Init->getExprLoc(), DiagID: diag::err_in_class_initializer_non_constant)
13680 << Init->getSourceRange();
13681 VDecl->setInvalidDecl();
13682 }
13683 }
13684
13685 // Suggest adding 'constexpr' in C++11 for literal types.
13686 } else if (getLangOpts().CPlusPlus11 && DclT->isLiteralType(Ctx: Context)) {
13687 Diag(Loc: VDecl->getLocation(), DiagID: diag::err_in_class_initializer_literal_type)
13688 << DclT << Init->getSourceRange()
13689 << FixItHint::CreateInsertion(InsertionLoc: VDecl->getBeginLoc(), Code: "constexpr ");
13690 VDecl->setConstexpr(true);
13691
13692 } else {
13693 Diag(Loc: VDecl->getLocation(), DiagID: diag::err_in_class_initializer_bad_type)
13694 << DclT << Init->getSourceRange();
13695 VDecl->setInvalidDecl();
13696 }
13697 } else if (VDecl->isFileVarDecl()) {
13698 // In C, extern is typically used to avoid tentative definitions when
13699 // declaring variables in headers, but adding an initializer makes it a
13700 // definition. This is somewhat confusing, so GCC and Clang both warn on it.
13701 // In C++, extern is often used to give implicitly static const variables
13702 // external linkage, so don't warn in that case. If selectany is present,
13703 // this might be header code intended for C and C++ inclusion, so apply the
13704 // C++ rules.
13705 if (VDecl->getStorageClass() == SC_Extern &&
13706 ((!getLangOpts().CPlusPlus && !VDecl->hasAttr<SelectAnyAttr>()) ||
13707 !Context.getBaseElementType(QT: VDecl->getType()).isConstQualified()) &&
13708 !(getLangOpts().CPlusPlus && VDecl->isExternC()) &&
13709 !isTemplateInstantiation(Kind: VDecl->getTemplateSpecializationKind()))
13710 Diag(Loc: VDecl->getLocation(), DiagID: diag::warn_extern_init);
13711
13712 // In Microsoft C++ mode, a const variable defined in namespace scope has
13713 // external linkage by default if the variable is declared with
13714 // __declspec(dllexport).
13715 if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
13716 getLangOpts().CPlusPlus && VDecl->getType().isConstQualified() &&
13717 VDecl->hasAttr<DLLExportAttr>() && VDecl->getDefinition())
13718 VDecl->setStorageClass(SC_Extern);
13719
13720 // C99 6.7.8p4. All file scoped initializers need to be constant.
13721 // Avoid duplicate diagnostics for constexpr variables.
13722 if (!getLangOpts().CPlusPlus && !VDecl->isInvalidDecl() &&
13723 !VDecl->isConstexpr())
13724 CheckForConstantInitializer(Init);
13725 }
13726
13727 QualType InitType = Init->getType();
13728 if (!InitType.isNull() &&
13729 (InitType.hasNonTrivialToPrimitiveDefaultInitializeCUnion() ||
13730 InitType.hasNonTrivialToPrimitiveCopyCUnion()))
13731 checkNonTrivialCUnionInInitializer(Init, Loc: Init->getExprLoc());
13732
13733 // We will represent direct-initialization similarly to copy-initialization:
13734 // int x(1); -as-> int x = 1;
13735 // ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c);
13736 //
13737 // Clients that want to distinguish between the two forms, can check for
13738 // direct initializer using VarDecl::getInitStyle().
13739 // A major benefit is that clients that don't particularly care about which
13740 // exactly form was it (like the CodeGen) can handle both cases without
13741 // special case code.
13742
13743 // C++ 8.5p11:
13744 // The form of initialization (using parentheses or '=') is generally
13745 // insignificant, but does matter when the entity being initialized has a
13746 // class type.
13747 if (CXXDirectInit) {
13748 assert(DirectInit && "Call-style initializer must be direct init.");
13749 VDecl->setInitStyle(IsParenListInit ? VarDecl::ParenListInit
13750 : VarDecl::CallInit);
13751 } else if (DirectInit) {
13752 // This must be list-initialization. No other way is direct-initialization.
13753 VDecl->setInitStyle(VarDecl::ListInit);
13754 }
13755
13756 if (LangOpts.OpenMP &&
13757 (LangOpts.OpenMPIsTargetDevice || !LangOpts.OMPTargetTriples.empty()) &&
13758 VDecl->isFileVarDecl())
13759 DeclsToCheckForDeferredDiags.insert(X: VDecl);
13760 CheckCompleteVariableDeclaration(VD: VDecl);
13761}
13762
13763void Sema::ActOnInitializerError(Decl *D) {
13764 // Our main concern here is re-establishing invariants like "a
13765 // variable's type is either dependent or complete".
13766 if (!D || D->isInvalidDecl()) return;
13767
13768 VarDecl *VD = dyn_cast<VarDecl>(Val: D);
13769 if (!VD) return;
13770
13771 // Bindings are not usable if we can't make sense of the initializer.
13772 if (auto *DD = dyn_cast<DecompositionDecl>(Val: D))
13773 for (auto *BD : DD->bindings())
13774 BD->setInvalidDecl();
13775
13776 // Auto types are meaningless if we can't make sense of the initializer.
13777 if (VD->getType()->isUndeducedType()) {
13778 D->setInvalidDecl();
13779 return;
13780 }
13781
13782 QualType Ty = VD->getType();
13783 if (Ty->isDependentType()) return;
13784
13785 // Require a complete type.
13786 if (RequireCompleteType(Loc: VD->getLocation(),
13787 T: Context.getBaseElementType(QT: Ty),
13788 DiagID: diag::err_typecheck_decl_incomplete_type)) {
13789 VD->setInvalidDecl();
13790 return;
13791 }
13792
13793 // Require a non-abstract type.
13794 if (RequireNonAbstractType(Loc: VD->getLocation(), T: Ty,
13795 DiagID: diag::err_abstract_type_in_decl,
13796 Args: AbstractVariableType)) {
13797 VD->setInvalidDecl();
13798 return;
13799 }
13800
13801 // Don't bother complaining about constructors or destructors,
13802 // though.
13803}
13804
13805void Sema::ActOnUninitializedDecl(Decl *RealDecl) {
13806 // If there is no declaration, there was an error parsing it. Just ignore it.
13807 if (!RealDecl)
13808 return;
13809
13810 if (VarDecl *Var = dyn_cast<VarDecl>(Val: RealDecl)) {
13811 QualType Type = Var->getType();
13812
13813 // C++1z [dcl.dcl]p1 grammar implies that an initializer is mandatory.
13814 if (isa<DecompositionDecl>(Val: RealDecl)) {
13815 Diag(Loc: Var->getLocation(), DiagID: diag::err_decomp_decl_requires_init) << Var;
13816 Var->setInvalidDecl();
13817 return;
13818 }
13819
13820 if (Type->isUndeducedType() &&
13821 DeduceVariableDeclarationType(VDecl: Var, DirectInit: false, Init: nullptr))
13822 return;
13823
13824 // C++11 [class.static.data]p3: A static data member can be declared with
13825 // the constexpr specifier; if so, its declaration shall specify
13826 // a brace-or-equal-initializer.
13827 // C++11 [dcl.constexpr]p1: The constexpr specifier shall be applied only to
13828 // the definition of a variable [...] or the declaration of a static data
13829 // member.
13830 if (Var->isConstexpr() && !Var->isThisDeclarationADefinition() &&
13831 !Var->isThisDeclarationADemotedDefinition()) {
13832 if (Var->isStaticDataMember()) {
13833 // C++1z removes the relevant rule; the in-class declaration is always
13834 // a definition there.
13835 if (!getLangOpts().CPlusPlus17 &&
13836 !Context.getTargetInfo().getCXXABI().isMicrosoft()) {
13837 Diag(Loc: Var->getLocation(),
13838 DiagID: diag::err_constexpr_static_mem_var_requires_init)
13839 << Var;
13840 Var->setInvalidDecl();
13841 return;
13842 }
13843 } else {
13844 Diag(Loc: Var->getLocation(), DiagID: diag::err_invalid_constexpr_var_decl);
13845 Var->setInvalidDecl();
13846 return;
13847 }
13848 }
13849
13850 // OpenCL v1.1 s6.5.3: variables declared in the constant address space must
13851 // be initialized.
13852 if (!Var->isInvalidDecl() &&
13853 Var->getType().getAddressSpace() == LangAS::opencl_constant &&
13854 Var->getStorageClass() != SC_Extern && !Var->getInit()) {
13855 bool HasConstExprDefaultConstructor = false;
13856 if (CXXRecordDecl *RD = Var->getType()->getAsCXXRecordDecl()) {
13857 for (auto *Ctor : RD->ctors()) {
13858 if (Ctor->isConstexpr() && Ctor->getNumParams() == 0 &&
13859 Ctor->getMethodQualifiers().getAddressSpace() ==
13860 LangAS::opencl_constant) {
13861 HasConstExprDefaultConstructor = true;
13862 }
13863 }
13864 }
13865 if (!HasConstExprDefaultConstructor) {
13866 Diag(Loc: Var->getLocation(), DiagID: diag::err_opencl_constant_no_init);
13867 Var->setInvalidDecl();
13868 return;
13869 }
13870 }
13871
13872 if (!Var->isInvalidDecl() && RealDecl->hasAttr<LoaderUninitializedAttr>()) {
13873 if (Var->getStorageClass() == SC_Extern) {
13874 Diag(Loc: Var->getLocation(), DiagID: diag::err_loader_uninitialized_extern_decl)
13875 << Var;
13876 Var->setInvalidDecl();
13877 return;
13878 }
13879 if (RequireCompleteType(Loc: Var->getLocation(), T: Var->getType(),
13880 DiagID: diag::err_typecheck_decl_incomplete_type)) {
13881 Var->setInvalidDecl();
13882 return;
13883 }
13884 if (CXXRecordDecl *RD = Var->getType()->getAsCXXRecordDecl()) {
13885 if (!RD->hasTrivialDefaultConstructor()) {
13886 Diag(Loc: Var->getLocation(), DiagID: diag::err_loader_uninitialized_trivial_ctor);
13887 Var->setInvalidDecl();
13888 return;
13889 }
13890 }
13891 // The declaration is uninitialized, no need for further checks.
13892 return;
13893 }
13894
13895 VarDecl::DefinitionKind DefKind = Var->isThisDeclarationADefinition();
13896 if (!Var->isInvalidDecl() && DefKind != VarDecl::DeclarationOnly &&
13897 Var->getType().hasNonTrivialToPrimitiveDefaultInitializeCUnion())
13898 checkNonTrivialCUnion(QT: Var->getType(), Loc: Var->getLocation(),
13899 UseContext: NTCUC_DefaultInitializedObject, NonTrivialKind: NTCUK_Init);
13900
13901
13902 switch (DefKind) {
13903 case VarDecl::Definition:
13904 if (!Var->isStaticDataMember() || !Var->getAnyInitializer())
13905 break;
13906
13907 // We have an out-of-line definition of a static data member
13908 // that has an in-class initializer, so we type-check this like
13909 // a declaration.
13910 //
13911 [[fallthrough]];
13912
13913 case VarDecl::DeclarationOnly:
13914 // It's only a declaration.
13915
13916 // Block scope. C99 6.7p7: If an identifier for an object is
13917 // declared with no linkage (C99 6.2.2p6), the type for the
13918 // object shall be complete.
13919 if (!Type->isDependentType() && Var->isLocalVarDecl() &&
13920 !Var->hasLinkage() && !Var->isInvalidDecl() &&
13921 RequireCompleteType(Loc: Var->getLocation(), T: Type,
13922 DiagID: diag::err_typecheck_decl_incomplete_type))
13923 Var->setInvalidDecl();
13924
13925 // Make sure that the type is not abstract.
13926 if (!Type->isDependentType() && !Var->isInvalidDecl() &&
13927 RequireNonAbstractType(Loc: Var->getLocation(), T: Type,
13928 DiagID: diag::err_abstract_type_in_decl,
13929 Args: AbstractVariableType))
13930 Var->setInvalidDecl();
13931 if (!Type->isDependentType() && !Var->isInvalidDecl() &&
13932 Var->getStorageClass() == SC_PrivateExtern) {
13933 Diag(Loc: Var->getLocation(), DiagID: diag::warn_private_extern);
13934 Diag(Loc: Var->getLocation(), DiagID: diag::note_private_extern);
13935 }
13936
13937 if (Context.getTargetInfo().allowDebugInfoForExternalRef() &&
13938 !Var->isInvalidDecl())
13939 ExternalDeclarations.push_back(Elt: Var);
13940
13941 return;
13942
13943 case VarDecl::TentativeDefinition:
13944 // File scope. C99 6.9.2p2: A declaration of an identifier for an
13945 // object that has file scope without an initializer, and without a
13946 // storage-class specifier or with the storage-class specifier "static",
13947 // constitutes a tentative definition. Note: A tentative definition with
13948 // external linkage is valid (C99 6.2.2p5).
13949 if (!Var->isInvalidDecl()) {
13950 if (const IncompleteArrayType *ArrayT
13951 = Context.getAsIncompleteArrayType(T: Type)) {
13952 if (RequireCompleteSizedType(
13953 Loc: Var->getLocation(), T: ArrayT->getElementType(),
13954 DiagID: diag::err_array_incomplete_or_sizeless_type))
13955 Var->setInvalidDecl();
13956 } else if (Var->getStorageClass() == SC_Static) {
13957 // C99 6.9.2p3: If the declaration of an identifier for an object is
13958 // a tentative definition and has internal linkage (C99 6.2.2p3), the
13959 // declared type shall not be an incomplete type.
13960 // NOTE: code such as the following
13961 // static struct s;
13962 // struct s { int a; };
13963 // is accepted by gcc. Hence here we issue a warning instead of
13964 // an error and we do not invalidate the static declaration.
13965 // NOTE: to avoid multiple warnings, only check the first declaration.
13966 if (Var->isFirstDecl())
13967 RequireCompleteType(Loc: Var->getLocation(), T: Type,
13968 DiagID: diag::ext_typecheck_decl_incomplete_type);
13969 }
13970 }
13971
13972 // Record the tentative definition; we're done.
13973 if (!Var->isInvalidDecl())
13974 TentativeDefinitions.push_back(LocalValue: Var);
13975 return;
13976 }
13977
13978 // Provide a specific diagnostic for uninitialized variable
13979 // definitions with incomplete array type.
13980 if (Type->isIncompleteArrayType()) {
13981 if (Var->isConstexpr())
13982 Diag(Loc: Var->getLocation(), DiagID: diag::err_constexpr_var_requires_const_init)
13983 << Var;
13984 else
13985 Diag(Loc: Var->getLocation(),
13986 DiagID: diag::err_typecheck_incomplete_array_needs_initializer);
13987 Var->setInvalidDecl();
13988 return;
13989 }
13990
13991 // Provide a specific diagnostic for uninitialized variable
13992 // definitions with reference type.
13993 if (Type->isReferenceType()) {
13994 Diag(Loc: Var->getLocation(), DiagID: diag::err_reference_var_requires_init)
13995 << Var << SourceRange(Var->getLocation(), Var->getLocation());
13996 return;
13997 }
13998
13999 // Do not attempt to type-check the default initializer for a
14000 // variable with dependent type.
14001 if (Type->isDependentType())
14002 return;
14003
14004 if (Var->isInvalidDecl())
14005 return;
14006
14007 if (!Var->hasAttr<AliasAttr>()) {
14008 if (RequireCompleteType(Loc: Var->getLocation(),
14009 T: Context.getBaseElementType(QT: Type),
14010 DiagID: diag::err_typecheck_decl_incomplete_type)) {
14011 Var->setInvalidDecl();
14012 return;
14013 }
14014 } else {
14015 return;
14016 }
14017
14018 // The variable can not have an abstract class type.
14019 if (RequireNonAbstractType(Loc: Var->getLocation(), T: Type,
14020 DiagID: diag::err_abstract_type_in_decl,
14021 Args: AbstractVariableType)) {
14022 Var->setInvalidDecl();
14023 return;
14024 }
14025
14026 // Check for jumps past the implicit initializer. C++0x
14027 // clarifies that this applies to a "variable with automatic
14028 // storage duration", not a "local variable".
14029 // C++11 [stmt.dcl]p3
14030 // A program that jumps from a point where a variable with automatic
14031 // storage duration is not in scope to a point where it is in scope is
14032 // ill-formed unless the variable has scalar type, class type with a
14033 // trivial default constructor and a trivial destructor, a cv-qualified
14034 // version of one of these types, or an array of one of the preceding
14035 // types and is declared without an initializer.
14036 if (getLangOpts().CPlusPlus && Var->hasLocalStorage()) {
14037 if (const RecordType *Record
14038 = Context.getBaseElementType(QT: Type)->getAs<RecordType>()) {
14039 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Val: Record->getDecl());
14040 // Mark the function (if we're in one) for further checking even if the
14041 // looser rules of C++11 do not require such checks, so that we can
14042 // diagnose incompatibilities with C++98.
14043 if (!CXXRecord->isPOD())
14044 setFunctionHasBranchProtectedScope();
14045 }
14046 }
14047 // In OpenCL, we can't initialize objects in the __local address space,
14048 // even implicitly, so don't synthesize an implicit initializer.
14049 if (getLangOpts().OpenCL &&
14050 Var->getType().getAddressSpace() == LangAS::opencl_local)
14051 return;
14052 // C++03 [dcl.init]p9:
14053 // If no initializer is specified for an object, and the
14054 // object is of (possibly cv-qualified) non-POD class type (or
14055 // array thereof), the object shall be default-initialized; if
14056 // the object is of const-qualified type, the underlying class
14057 // type shall have a user-declared default
14058 // constructor. Otherwise, if no initializer is specified for
14059 // a non- static object, the object and its subobjects, if
14060 // any, have an indeterminate initial value); if the object
14061 // or any of its subobjects are of const-qualified type, the
14062 // program is ill-formed.
14063 // C++0x [dcl.init]p11:
14064 // If no initializer is specified for an object, the object is
14065 // default-initialized; [...].
14066 InitializedEntity Entity = InitializedEntity::InitializeVariable(Var);
14067 InitializationKind Kind
14068 = InitializationKind::CreateDefault(InitLoc: Var->getLocation());
14069
14070 InitializationSequence InitSeq(*this, Entity, Kind, std::nullopt);
14071 ExprResult Init = InitSeq.Perform(S&: *this, Entity, Kind, Args: std::nullopt);
14072
14073 if (Init.get()) {
14074 Var->setInit(MaybeCreateExprWithCleanups(SubExpr: Init.get()));
14075 // This is important for template substitution.
14076 Var->setInitStyle(VarDecl::CallInit);
14077 } else if (Init.isInvalid()) {
14078 // If default-init fails, attach a recovery-expr initializer to track
14079 // that initialization was attempted and failed.
14080 auto RecoveryExpr =
14081 CreateRecoveryExpr(Begin: Var->getLocation(), End: Var->getLocation(), SubExprs: {});
14082 if (RecoveryExpr.get())
14083 Var->setInit(RecoveryExpr.get());
14084 }
14085
14086 CheckCompleteVariableDeclaration(VD: Var);
14087 }
14088}
14089
14090void Sema::ActOnCXXForRangeDecl(Decl *D) {
14091 // If there is no declaration, there was an error parsing it. Ignore it.
14092 if (!D)
14093 return;
14094
14095 VarDecl *VD = dyn_cast<VarDecl>(Val: D);
14096 if (!VD) {
14097 Diag(Loc: D->getLocation(), DiagID: diag::err_for_range_decl_must_be_var);
14098 D->setInvalidDecl();
14099 return;
14100 }
14101
14102 VD->setCXXForRangeDecl(true);
14103
14104 // for-range-declaration cannot be given a storage class specifier.
14105 int Error = -1;
14106 switch (VD->getStorageClass()) {
14107 case SC_None:
14108 break;
14109 case SC_Extern:
14110 Error = 0;
14111 break;
14112 case SC_Static:
14113 Error = 1;
14114 break;
14115 case SC_PrivateExtern:
14116 Error = 2;
14117 break;
14118 case SC_Auto:
14119 Error = 3;
14120 break;
14121 case SC_Register:
14122 Error = 4;
14123 break;
14124 }
14125
14126 // for-range-declaration cannot be given a storage class specifier con't.
14127 switch (VD->getTSCSpec()) {
14128 case TSCS_thread_local:
14129 Error = 6;
14130 break;
14131 case TSCS___thread:
14132 case TSCS__Thread_local:
14133 case TSCS_unspecified:
14134 break;
14135 }
14136
14137 if (Error != -1) {
14138 Diag(Loc: VD->getOuterLocStart(), DiagID: diag::err_for_range_storage_class)
14139 << VD << Error;
14140 D->setInvalidDecl();
14141 }
14142}
14143
14144StmtResult Sema::ActOnCXXForRangeIdentifier(Scope *S, SourceLocation IdentLoc,
14145 IdentifierInfo *Ident,
14146 ParsedAttributes &Attrs) {
14147 // C++1y [stmt.iter]p1:
14148 // A range-based for statement of the form
14149 // for ( for-range-identifier : for-range-initializer ) statement
14150 // is equivalent to
14151 // for ( auto&& for-range-identifier : for-range-initializer ) statement
14152 DeclSpec DS(Attrs.getPool().getFactory());
14153
14154 const char *PrevSpec;
14155 unsigned DiagID;
14156 DS.SetTypeSpecType(T: DeclSpec::TST_auto, Loc: IdentLoc, PrevSpec, DiagID,
14157 Policy: getPrintingPolicy());
14158
14159 Declarator D(DS, ParsedAttributesView::none(), DeclaratorContext::ForInit);
14160 D.SetIdentifier(Id: Ident, IdLoc: IdentLoc);
14161 D.takeAttributes(attrs&: Attrs);
14162
14163 D.AddTypeInfo(TI: DeclaratorChunk::getReference(TypeQuals: 0, Loc: IdentLoc, /*lvalue*/ false),
14164 EndLoc: IdentLoc);
14165 Decl *Var = ActOnDeclarator(S, D);
14166 cast<VarDecl>(Val: Var)->setCXXForRangeDecl(true);
14167 FinalizeDeclaration(D: Var);
14168 return ActOnDeclStmt(Decl: FinalizeDeclaratorGroup(S, DS, Group: Var), StartLoc: IdentLoc,
14169 EndLoc: Attrs.Range.getEnd().isValid() ? Attrs.Range.getEnd()
14170 : IdentLoc);
14171}
14172
14173void Sema::CheckCompleteVariableDeclaration(VarDecl *var) {
14174 if (var->isInvalidDecl()) return;
14175
14176 CUDA().MaybeAddConstantAttr(VD: var);
14177
14178 if (getLangOpts().OpenCL) {
14179 // OpenCL v2.0 s6.12.5 - Every block variable declaration must have an
14180 // initialiser
14181 if (var->getTypeSourceInfo()->getType()->isBlockPointerType() &&
14182 !var->hasInit()) {
14183 Diag(Loc: var->getLocation(), DiagID: diag::err_opencl_invalid_block_declaration)
14184 << 1 /*Init*/;
14185 var->setInvalidDecl();
14186 return;
14187 }
14188 }
14189
14190 // In Objective-C, don't allow jumps past the implicit initialization of a
14191 // local retaining variable.
14192 if (getLangOpts().ObjC &&
14193 var->hasLocalStorage()) {
14194 switch (var->getType().getObjCLifetime()) {
14195 case Qualifiers::OCL_None:
14196 case Qualifiers::OCL_ExplicitNone:
14197 case Qualifiers::OCL_Autoreleasing:
14198 break;
14199
14200 case Qualifiers::OCL_Weak:
14201 case Qualifiers::OCL_Strong:
14202 setFunctionHasBranchProtectedScope();
14203 break;
14204 }
14205 }
14206
14207 if (var->hasLocalStorage() &&
14208 var->getType().isDestructedType() == QualType::DK_nontrivial_c_struct)
14209 setFunctionHasBranchProtectedScope();
14210
14211 // Warn about externally-visible variables being defined without a
14212 // prior declaration. We only want to do this for global
14213 // declarations, but we also specifically need to avoid doing it for
14214 // class members because the linkage of an anonymous class can
14215 // change if it's later given a typedef name.
14216 if (var->isThisDeclarationADefinition() &&
14217 var->getDeclContext()->getRedeclContext()->isFileContext() &&
14218 var->isExternallyVisible() && var->hasLinkage() &&
14219 !var->isInline() && !var->getDescribedVarTemplate() &&
14220 var->getStorageClass() != SC_Register &&
14221 !isa<VarTemplatePartialSpecializationDecl>(Val: var) &&
14222 !isTemplateInstantiation(Kind: var->getTemplateSpecializationKind()) &&
14223 !getDiagnostics().isIgnored(DiagID: diag::warn_missing_variable_declarations,
14224 Loc: var->getLocation())) {
14225 // Find a previous declaration that's not a definition.
14226 VarDecl *prev = var->getPreviousDecl();
14227 while (prev && prev->isThisDeclarationADefinition())
14228 prev = prev->getPreviousDecl();
14229
14230 if (!prev) {
14231 Diag(Loc: var->getLocation(), DiagID: diag::warn_missing_variable_declarations) << var;
14232 Diag(Loc: var->getTypeSpecStartLoc(), DiagID: diag::note_static_for_internal_linkage)
14233 << /* variable */ 0;
14234 }
14235 }
14236
14237 // Cache the result of checking for constant initialization.
14238 std::optional<bool> CacheHasConstInit;
14239 const Expr *CacheCulprit = nullptr;
14240 auto checkConstInit = [&]() mutable {
14241 if (!CacheHasConstInit)
14242 CacheHasConstInit = var->getInit()->isConstantInitializer(
14243 Ctx&: Context, ForRef: var->getType()->isReferenceType(), Culprit: &CacheCulprit);
14244 return *CacheHasConstInit;
14245 };
14246
14247 if (var->getTLSKind() == VarDecl::TLS_Static) {
14248 if (var->getType().isDestructedType()) {
14249 // GNU C++98 edits for __thread, [basic.start.term]p3:
14250 // The type of an object with thread storage duration shall not
14251 // have a non-trivial destructor.
14252 Diag(Loc: var->getLocation(), DiagID: diag::err_thread_nontrivial_dtor);
14253 if (getLangOpts().CPlusPlus11)
14254 Diag(Loc: var->getLocation(), DiagID: diag::note_use_thread_local);
14255 } else if (getLangOpts().CPlusPlus && var->hasInit()) {
14256 if (!checkConstInit()) {
14257 // GNU C++98 edits for __thread, [basic.start.init]p4:
14258 // An object of thread storage duration shall not require dynamic
14259 // initialization.
14260 // FIXME: Need strict checking here.
14261 Diag(Loc: CacheCulprit->getExprLoc(), DiagID: diag::err_thread_dynamic_init)
14262 << CacheCulprit->getSourceRange();
14263 if (getLangOpts().CPlusPlus11)
14264 Diag(Loc: var->getLocation(), DiagID: diag::note_use_thread_local);
14265 }
14266 }
14267 }
14268
14269
14270 if (!var->getType()->isStructureType() && var->hasInit() &&
14271 isa<InitListExpr>(Val: var->getInit())) {
14272 const auto *ILE = cast<InitListExpr>(Val: var->getInit());
14273 unsigned NumInits = ILE->getNumInits();
14274 if (NumInits > 2)
14275 for (unsigned I = 0; I < NumInits; ++I) {
14276 const auto *Init = ILE->getInit(Init: I);
14277 if (!Init)
14278 break;
14279 const auto *SL = dyn_cast<StringLiteral>(Val: Init->IgnoreImpCasts());
14280 if (!SL)
14281 break;
14282
14283 unsigned NumConcat = SL->getNumConcatenated();
14284 // Diagnose missing comma in string array initialization.
14285 // Do not warn when all the elements in the initializer are concatenated
14286 // together. Do not warn for macros too.
14287 if (NumConcat == 2 && !SL->getBeginLoc().isMacroID()) {
14288 bool OnlyOneMissingComma = true;
14289 for (unsigned J = I + 1; J < NumInits; ++J) {
14290 const auto *Init = ILE->getInit(Init: J);
14291 if (!Init)
14292 break;
14293 const auto *SLJ = dyn_cast<StringLiteral>(Val: Init->IgnoreImpCasts());
14294 if (!SLJ || SLJ->getNumConcatenated() > 1) {
14295 OnlyOneMissingComma = false;
14296 break;
14297 }
14298 }
14299
14300 if (OnlyOneMissingComma) {
14301 SmallVector<FixItHint, 1> Hints;
14302 for (unsigned i = 0; i < NumConcat - 1; ++i)
14303 Hints.push_back(Elt: FixItHint::CreateInsertion(
14304 InsertionLoc: PP.getLocForEndOfToken(Loc: SL->getStrTokenLoc(TokNum: i)), Code: ","));
14305
14306 Diag(Loc: SL->getStrTokenLoc(TokNum: 1),
14307 DiagID: diag::warn_concatenated_literal_array_init)
14308 << Hints;
14309 Diag(Loc: SL->getBeginLoc(),
14310 DiagID: diag::note_concatenated_string_literal_silence);
14311 }
14312 // In any case, stop now.
14313 break;
14314 }
14315 }
14316 }
14317
14318
14319 QualType type = var->getType();
14320
14321 if (var->hasAttr<BlocksAttr>())
14322 getCurFunction()->addByrefBlockVar(VD: var);
14323
14324 Expr *Init = var->getInit();
14325 bool GlobalStorage = var->hasGlobalStorage();
14326 bool IsGlobal = GlobalStorage && !var->isStaticLocal();
14327 QualType baseType = Context.getBaseElementType(QT: type);
14328 bool HasConstInit = true;
14329
14330 if (getLangOpts().C23 && var->isConstexpr() && !Init)
14331 Diag(Loc: var->getLocation(), DiagID: diag::err_constexpr_var_requires_const_init)
14332 << var;
14333
14334 // Check whether the initializer is sufficiently constant.
14335 if ((getLangOpts().CPlusPlus || (getLangOpts().C23 && var->isConstexpr())) &&
14336 !type->isDependentType() && Init && !Init->isValueDependent() &&
14337 (GlobalStorage || var->isConstexpr() ||
14338 var->mightBeUsableInConstantExpressions(C: Context))) {
14339 // If this variable might have a constant initializer or might be usable in
14340 // constant expressions, check whether or not it actually is now. We can't
14341 // do this lazily, because the result might depend on things that change
14342 // later, such as which constexpr functions happen to be defined.
14343 SmallVector<PartialDiagnosticAt, 8> Notes;
14344 if (!getLangOpts().CPlusPlus11 && !getLangOpts().C23) {
14345 // Prior to C++11, in contexts where a constant initializer is required,
14346 // the set of valid constant initializers is described by syntactic rules
14347 // in [expr.const]p2-6.
14348 // FIXME: Stricter checking for these rules would be useful for constinit /
14349 // -Wglobal-constructors.
14350 HasConstInit = checkConstInit();
14351
14352 // Compute and cache the constant value, and remember that we have a
14353 // constant initializer.
14354 if (HasConstInit) {
14355 (void)var->checkForConstantInitialization(Notes);
14356 Notes.clear();
14357 } else if (CacheCulprit) {
14358 Notes.emplace_back(Args: CacheCulprit->getExprLoc(),
14359 Args: PDiag(DiagID: diag::note_invalid_subexpr_in_const_expr));
14360 Notes.back().second << CacheCulprit->getSourceRange();
14361 }
14362 } else {
14363 // Evaluate the initializer to see if it's a constant initializer.
14364 HasConstInit = var->checkForConstantInitialization(Notes);
14365 }
14366
14367 if (HasConstInit) {
14368 // FIXME: Consider replacing the initializer with a ConstantExpr.
14369 } else if (var->isConstexpr()) {
14370 SourceLocation DiagLoc = var->getLocation();
14371 // If the note doesn't add any useful information other than a source
14372 // location, fold it into the primary diagnostic.
14373 if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
14374 diag::note_invalid_subexpr_in_const_expr) {
14375 DiagLoc = Notes[0].first;
14376 Notes.clear();
14377 }
14378 Diag(Loc: DiagLoc, DiagID: diag::err_constexpr_var_requires_const_init)
14379 << var << Init->getSourceRange();
14380 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
14381 Diag(Loc: Notes[I].first, PD: Notes[I].second);
14382 } else if (GlobalStorage && var->hasAttr<ConstInitAttr>()) {
14383 auto *Attr = var->getAttr<ConstInitAttr>();
14384 Diag(Loc: var->getLocation(), DiagID: diag::err_require_constant_init_failed)
14385 << Init->getSourceRange();
14386 Diag(Loc: Attr->getLocation(), DiagID: diag::note_declared_required_constant_init_here)
14387 << Attr->getRange() << Attr->isConstinit();
14388 for (auto &it : Notes)
14389 Diag(Loc: it.first, PD: it.second);
14390 } else if (IsGlobal &&
14391 !getDiagnostics().isIgnored(DiagID: diag::warn_global_constructor,
14392 Loc: var->getLocation())) {
14393 // Warn about globals which don't have a constant initializer. Don't
14394 // warn about globals with a non-trivial destructor because we already
14395 // warned about them.
14396 CXXRecordDecl *RD = baseType->getAsCXXRecordDecl();
14397 if (!(RD && !RD->hasTrivialDestructor())) {
14398 // checkConstInit() here permits trivial default initialization even in
14399 // C++11 onwards, where such an initializer is not a constant initializer
14400 // but nonetheless doesn't require a global constructor.
14401 if (!checkConstInit())
14402 Diag(Loc: var->getLocation(), DiagID: diag::warn_global_constructor)
14403 << Init->getSourceRange();
14404 }
14405 }
14406 }
14407
14408 // Apply section attributes and pragmas to global variables.
14409 if (GlobalStorage && var->isThisDeclarationADefinition() &&
14410 !inTemplateInstantiation()) {
14411 PragmaStack<StringLiteral *> *Stack = nullptr;
14412 int SectionFlags = ASTContext::PSF_Read;
14413 bool MSVCEnv =
14414 Context.getTargetInfo().getTriple().isWindowsMSVCEnvironment();
14415 std::optional<QualType::NonConstantStorageReason> Reason;
14416 if (HasConstInit &&
14417 !(Reason = var->getType().isNonConstantStorage(Ctx: Context, ExcludeCtor: true, ExcludeDtor: false))) {
14418 Stack = &ConstSegStack;
14419 } else {
14420 SectionFlags |= ASTContext::PSF_Write;
14421 Stack = var->hasInit() && HasConstInit ? &DataSegStack : &BSSSegStack;
14422 }
14423 if (const SectionAttr *SA = var->getAttr<SectionAttr>()) {
14424 if (SA->getSyntax() == AttributeCommonInfo::AS_Declspec)
14425 SectionFlags |= ASTContext::PSF_Implicit;
14426 UnifySection(SectionName: SA->getName(), SectionFlags, TheDecl: var);
14427 } else if (Stack->CurrentValue) {
14428 if (Stack != &ConstSegStack && MSVCEnv &&
14429 ConstSegStack.CurrentValue != ConstSegStack.DefaultValue &&
14430 var->getType().isConstQualified()) {
14431 assert((!Reason || Reason != QualType::NonConstantStorageReason::
14432 NonConstNonReferenceType) &&
14433 "This case should've already been handled elsewhere");
14434 Diag(Loc: var->getLocation(), DiagID: diag::warn_section_msvc_compat)
14435 << var << ConstSegStack.CurrentValue << (int)(!HasConstInit
14436 ? QualType::NonConstantStorageReason::NonTrivialCtor
14437 : *Reason);
14438 }
14439 SectionFlags |= ASTContext::PSF_Implicit;
14440 auto SectionName = Stack->CurrentValue->getString();
14441 var->addAttr(A: SectionAttr::CreateImplicit(Ctx&: Context, Name: SectionName,
14442 Range: Stack->CurrentPragmaLocation,
14443 S: SectionAttr::Declspec_allocate));
14444 if (UnifySection(SectionName, SectionFlags, TheDecl: var))
14445 var->dropAttr<SectionAttr>();
14446 }
14447
14448 // Apply the init_seg attribute if this has an initializer. If the
14449 // initializer turns out to not be dynamic, we'll end up ignoring this
14450 // attribute.
14451 if (CurInitSeg && var->getInit())
14452 var->addAttr(A: InitSegAttr::CreateImplicit(Ctx&: Context, Section: CurInitSeg->getString(),
14453 Range: CurInitSegLoc));
14454 }
14455
14456 // All the following checks are C++ only.
14457 if (!getLangOpts().CPlusPlus) {
14458 // If this variable must be emitted, add it as an initializer for the
14459 // current module.
14460 if (Context.DeclMustBeEmitted(D: var) && !ModuleScopes.empty())
14461 Context.addModuleInitializer(M: ModuleScopes.back().Module, Init: var);
14462 return;
14463 }
14464
14465 // Require the destructor.
14466 if (!type->isDependentType())
14467 if (const RecordType *recordType = baseType->getAs<RecordType>())
14468 FinalizeVarWithDestructor(VD: var, DeclInitType: recordType);
14469
14470 // If this variable must be emitted, add it as an initializer for the current
14471 // module.
14472 if (Context.DeclMustBeEmitted(D: var) && !ModuleScopes.empty())
14473 Context.addModuleInitializer(M: ModuleScopes.back().Module, Init: var);
14474
14475 // Build the bindings if this is a structured binding declaration.
14476 if (auto *DD = dyn_cast<DecompositionDecl>(Val: var))
14477 CheckCompleteDecompositionDeclaration(DD);
14478}
14479
14480void Sema::CheckStaticLocalForDllExport(VarDecl *VD) {
14481 assert(VD->isStaticLocal());
14482
14483 auto *FD = dyn_cast_or_null<FunctionDecl>(Val: VD->getParentFunctionOrMethod());
14484
14485 // Find outermost function when VD is in lambda function.
14486 while (FD && !getDLLAttr(D: FD) &&
14487 !FD->hasAttr<DLLExportStaticLocalAttr>() &&
14488 !FD->hasAttr<DLLImportStaticLocalAttr>()) {
14489 FD = dyn_cast_or_null<FunctionDecl>(Val: FD->getParentFunctionOrMethod());
14490 }
14491
14492 if (!FD)
14493 return;
14494
14495 // Static locals inherit dll attributes from their function.
14496 if (Attr *A = getDLLAttr(D: FD)) {
14497 auto *NewAttr = cast<InheritableAttr>(Val: A->clone(C&: getASTContext()));
14498 NewAttr->setInherited(true);
14499 VD->addAttr(A: NewAttr);
14500 } else if (Attr *A = FD->getAttr<DLLExportStaticLocalAttr>()) {
14501 auto *NewAttr = DLLExportAttr::CreateImplicit(Ctx&: getASTContext(), CommonInfo: *A);
14502 NewAttr->setInherited(true);
14503 VD->addAttr(A: NewAttr);
14504
14505 // Export this function to enforce exporting this static variable even
14506 // if it is not used in this compilation unit.
14507 if (!FD->hasAttr<DLLExportAttr>())
14508 FD->addAttr(A: NewAttr);
14509
14510 } else if (Attr *A = FD->getAttr<DLLImportStaticLocalAttr>()) {
14511 auto *NewAttr = DLLImportAttr::CreateImplicit(Ctx&: getASTContext(), CommonInfo: *A);
14512 NewAttr->setInherited(true);
14513 VD->addAttr(A: NewAttr);
14514 }
14515}
14516
14517void Sema::CheckThreadLocalForLargeAlignment(VarDecl *VD) {
14518 assert(VD->getTLSKind());
14519
14520 // Perform TLS alignment check here after attributes attached to the variable
14521 // which may affect the alignment have been processed. Only perform the check
14522 // if the target has a maximum TLS alignment (zero means no constraints).
14523 if (unsigned MaxAlign = Context.getTargetInfo().getMaxTLSAlign()) {
14524 // Protect the check so that it's not performed on dependent types and
14525 // dependent alignments (we can't determine the alignment in that case).
14526 if (!VD->hasDependentAlignment()) {
14527 CharUnits MaxAlignChars = Context.toCharUnitsFromBits(BitSize: MaxAlign);
14528 if (Context.getDeclAlign(D: VD) > MaxAlignChars) {
14529 Diag(Loc: VD->getLocation(), DiagID: diag::err_tls_var_aligned_over_maximum)
14530 << (unsigned)Context.getDeclAlign(D: VD).getQuantity() << VD
14531 << (unsigned)MaxAlignChars.getQuantity();
14532 }
14533 }
14534 }
14535}
14536
14537void Sema::FinalizeDeclaration(Decl *ThisDecl) {
14538 // Note that we are no longer parsing the initializer for this declaration.
14539 ParsingInitForAutoVars.erase(Ptr: ThisDecl);
14540
14541 VarDecl *VD = dyn_cast_or_null<VarDecl>(Val: ThisDecl);
14542 if (!VD)
14543 return;
14544
14545 // Apply an implicit SectionAttr if '#pragma clang section bss|data|rodata' is active
14546 if (VD->hasGlobalStorage() && VD->isThisDeclarationADefinition() &&
14547 !inTemplateInstantiation() && !VD->hasAttr<SectionAttr>()) {
14548 if (PragmaClangBSSSection.Valid)
14549 VD->addAttr(A: PragmaClangBSSSectionAttr::CreateImplicit(
14550 Ctx&: Context, Name: PragmaClangBSSSection.SectionName,
14551 Range: PragmaClangBSSSection.PragmaLocation));
14552 if (PragmaClangDataSection.Valid)
14553 VD->addAttr(A: PragmaClangDataSectionAttr::CreateImplicit(
14554 Ctx&: Context, Name: PragmaClangDataSection.SectionName,
14555 Range: PragmaClangDataSection.PragmaLocation));
14556 if (PragmaClangRodataSection.Valid)
14557 VD->addAttr(A: PragmaClangRodataSectionAttr::CreateImplicit(
14558 Ctx&: Context, Name: PragmaClangRodataSection.SectionName,
14559 Range: PragmaClangRodataSection.PragmaLocation));
14560 if (PragmaClangRelroSection.Valid)
14561 VD->addAttr(A: PragmaClangRelroSectionAttr::CreateImplicit(
14562 Ctx&: Context, Name: PragmaClangRelroSection.SectionName,
14563 Range: PragmaClangRelroSection.PragmaLocation));
14564 }
14565
14566 if (auto *DD = dyn_cast<DecompositionDecl>(Val: ThisDecl)) {
14567 for (auto *BD : DD->bindings()) {
14568 FinalizeDeclaration(ThisDecl: BD);
14569 }
14570 }
14571
14572 checkAttributesAfterMerging(S&: *this, ND&: *VD);
14573
14574 if (VD->isStaticLocal())
14575 CheckStaticLocalForDllExport(VD);
14576
14577 if (VD->getTLSKind())
14578 CheckThreadLocalForLargeAlignment(VD);
14579
14580 // Perform check for initializers of device-side global variables.
14581 // CUDA allows empty constructors as initializers (see E.2.3.1, CUDA
14582 // 7.5). We must also apply the same checks to all __shared__
14583 // variables whether they are local or not. CUDA also allows
14584 // constant initializers for __constant__ and __device__ variables.
14585 if (getLangOpts().CUDA)
14586 CUDA().checkAllowedInitializer(VD);
14587
14588 // Grab the dllimport or dllexport attribute off of the VarDecl.
14589 const InheritableAttr *DLLAttr = getDLLAttr(D: VD);
14590
14591 // Imported static data members cannot be defined out-of-line.
14592 if (const auto *IA = dyn_cast_or_null<DLLImportAttr>(Val: DLLAttr)) {
14593 if (VD->isStaticDataMember() && VD->isOutOfLine() &&
14594 VD->isThisDeclarationADefinition()) {
14595 // We allow definitions of dllimport class template static data members
14596 // with a warning.
14597 CXXRecordDecl *Context =
14598 cast<CXXRecordDecl>(Val: VD->getFirstDecl()->getDeclContext());
14599 bool IsClassTemplateMember =
14600 isa<ClassTemplatePartialSpecializationDecl>(Val: Context) ||
14601 Context->getDescribedClassTemplate();
14602
14603 Diag(Loc: VD->getLocation(),
14604 DiagID: IsClassTemplateMember
14605 ? diag::warn_attribute_dllimport_static_field_definition
14606 : diag::err_attribute_dllimport_static_field_definition);
14607 Diag(Loc: IA->getLocation(), DiagID: diag::note_attribute);
14608 if (!IsClassTemplateMember)
14609 VD->setInvalidDecl();
14610 }
14611 }
14612
14613 // dllimport/dllexport variables cannot be thread local, their TLS index
14614 // isn't exported with the variable.
14615 if (DLLAttr && VD->getTLSKind()) {
14616 auto *F = dyn_cast_or_null<FunctionDecl>(Val: VD->getParentFunctionOrMethod());
14617 if (F && getDLLAttr(D: F)) {
14618 assert(VD->isStaticLocal());
14619 // But if this is a static local in a dlimport/dllexport function, the
14620 // function will never be inlined, which means the var would never be
14621 // imported, so having it marked import/export is safe.
14622 } else {
14623 Diag(Loc: VD->getLocation(), DiagID: diag::err_attribute_dll_thread_local) << VD
14624 << DLLAttr;
14625 VD->setInvalidDecl();
14626 }
14627 }
14628
14629 if (UsedAttr *Attr = VD->getAttr<UsedAttr>()) {
14630 if (!Attr->isInherited() && !VD->isThisDeclarationADefinition()) {
14631 Diag(Loc: Attr->getLocation(), DiagID: diag::warn_attribute_ignored_on_non_definition)
14632 << Attr;
14633 VD->dropAttr<UsedAttr>();
14634 }
14635 }
14636 if (RetainAttr *Attr = VD->getAttr<RetainAttr>()) {
14637 if (!Attr->isInherited() && !VD->isThisDeclarationADefinition()) {
14638 Diag(Loc: Attr->getLocation(), DiagID: diag::warn_attribute_ignored_on_non_definition)
14639 << Attr;
14640 VD->dropAttr<RetainAttr>();
14641 }
14642 }
14643
14644 const DeclContext *DC = VD->getDeclContext();
14645 // If there's a #pragma GCC visibility in scope, and this isn't a class
14646 // member, set the visibility of this variable.
14647 if (DC->getRedeclContext()->isFileContext() && VD->isExternallyVisible())
14648 AddPushedVisibilityAttribute(RD: VD);
14649
14650 // FIXME: Warn on unused var template partial specializations.
14651 if (VD->isFileVarDecl() && !isa<VarTemplatePartialSpecializationDecl>(Val: VD))
14652 MarkUnusedFileScopedDecl(D: VD);
14653
14654 // Now we have parsed the initializer and can update the table of magic
14655 // tag values.
14656 if (!VD->hasAttr<TypeTagForDatatypeAttr>() ||
14657 !VD->getType()->isIntegralOrEnumerationType())
14658 return;
14659
14660 for (const auto *I : ThisDecl->specific_attrs<TypeTagForDatatypeAttr>()) {
14661 const Expr *MagicValueExpr = VD->getInit();
14662 if (!MagicValueExpr) {
14663 continue;
14664 }
14665 std::optional<llvm::APSInt> MagicValueInt;
14666 if (!(MagicValueInt = MagicValueExpr->getIntegerConstantExpr(Ctx: Context))) {
14667 Diag(Loc: I->getRange().getBegin(),
14668 DiagID: diag::err_type_tag_for_datatype_not_ice)
14669 << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange();
14670 continue;
14671 }
14672 if (MagicValueInt->getActiveBits() > 64) {
14673 Diag(Loc: I->getRange().getBegin(),
14674 DiagID: diag::err_type_tag_for_datatype_too_large)
14675 << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange();
14676 continue;
14677 }
14678 uint64_t MagicValue = MagicValueInt->getZExtValue();
14679 RegisterTypeTagForDatatype(ArgumentKind: I->getArgumentKind(),
14680 MagicValue,
14681 Type: I->getMatchingCType(),
14682 LayoutCompatible: I->getLayoutCompatible(),
14683 MustBeNull: I->getMustBeNull());
14684 }
14685}
14686
14687static bool hasDeducedAuto(DeclaratorDecl *DD) {
14688 auto *VD = dyn_cast<VarDecl>(Val: DD);
14689 return VD && !VD->getType()->hasAutoForTrailingReturnType();
14690}
14691
14692Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS,
14693 ArrayRef<Decl *> Group) {
14694 SmallVector<Decl*, 8> Decls;
14695
14696 if (DS.isTypeSpecOwned())
14697 Decls.push_back(Elt: DS.getRepAsDecl());
14698
14699 DeclaratorDecl *FirstDeclaratorInGroup = nullptr;
14700 DecompositionDecl *FirstDecompDeclaratorInGroup = nullptr;
14701 bool DiagnosedMultipleDecomps = false;
14702 DeclaratorDecl *FirstNonDeducedAutoInGroup = nullptr;
14703 bool DiagnosedNonDeducedAuto = false;
14704
14705 for (Decl *D : Group) {
14706 if (!D)
14707 continue;
14708 // Check if the Decl has been declared in '#pragma omp declare target'
14709 // directive and has static storage duration.
14710 if (auto *VD = dyn_cast<VarDecl>(Val: D);
14711 LangOpts.OpenMP && VD && VD->hasAttr<OMPDeclareTargetDeclAttr>() &&
14712 VD->hasGlobalStorage())
14713 OpenMP().ActOnOpenMPDeclareTargetInitializer(D);
14714 // For declarators, there are some additional syntactic-ish checks we need
14715 // to perform.
14716 if (auto *DD = dyn_cast<DeclaratorDecl>(Val: D)) {
14717 if (!FirstDeclaratorInGroup)
14718 FirstDeclaratorInGroup = DD;
14719 if (!FirstDecompDeclaratorInGroup)
14720 FirstDecompDeclaratorInGroup = dyn_cast<DecompositionDecl>(Val: D);
14721 if (!FirstNonDeducedAutoInGroup && DS.hasAutoTypeSpec() &&
14722 !hasDeducedAuto(DD))
14723 FirstNonDeducedAutoInGroup = DD;
14724
14725 if (FirstDeclaratorInGroup != DD) {
14726 // A decomposition declaration cannot be combined with any other
14727 // declaration in the same group.
14728 if (FirstDecompDeclaratorInGroup && !DiagnosedMultipleDecomps) {
14729 Diag(Loc: FirstDecompDeclaratorInGroup->getLocation(),
14730 DiagID: diag::err_decomp_decl_not_alone)
14731 << FirstDeclaratorInGroup->getSourceRange()
14732 << DD->getSourceRange();
14733 DiagnosedMultipleDecomps = true;
14734 }
14735
14736 // A declarator that uses 'auto' in any way other than to declare a
14737 // variable with a deduced type cannot be combined with any other
14738 // declarator in the same group.
14739 if (FirstNonDeducedAutoInGroup && !DiagnosedNonDeducedAuto) {
14740 Diag(Loc: FirstNonDeducedAutoInGroup->getLocation(),
14741 DiagID: diag::err_auto_non_deduced_not_alone)
14742 << FirstNonDeducedAutoInGroup->getType()
14743 ->hasAutoForTrailingReturnType()
14744 << FirstDeclaratorInGroup->getSourceRange()
14745 << DD->getSourceRange();
14746 DiagnosedNonDeducedAuto = true;
14747 }
14748 }
14749 }
14750
14751 Decls.push_back(Elt: D);
14752 }
14753
14754 if (DeclSpec::isDeclRep(T: DS.getTypeSpecType())) {
14755 if (TagDecl *Tag = dyn_cast_or_null<TagDecl>(Val: DS.getRepAsDecl())) {
14756 handleTagNumbering(Tag, TagScope: S);
14757 if (FirstDeclaratorInGroup && !Tag->hasNameForLinkage() &&
14758 getLangOpts().CPlusPlus)
14759 Context.addDeclaratorForUnnamedTagDecl(TD: Tag, DD: FirstDeclaratorInGroup);
14760 }
14761 }
14762
14763 return BuildDeclaratorGroup(Group: Decls);
14764}
14765
14766Sema::DeclGroupPtrTy
14767Sema::BuildDeclaratorGroup(MutableArrayRef<Decl *> Group) {
14768 // C++14 [dcl.spec.auto]p7: (DR1347)
14769 // If the type that replaces the placeholder type is not the same in each
14770 // deduction, the program is ill-formed.
14771 if (Group.size() > 1) {
14772 QualType Deduced;
14773 VarDecl *DeducedDecl = nullptr;
14774 for (unsigned i = 0, e = Group.size(); i != e; ++i) {
14775 VarDecl *D = dyn_cast<VarDecl>(Val: Group[i]);
14776 if (!D || D->isInvalidDecl())
14777 break;
14778 DeducedType *DT = D->getType()->getContainedDeducedType();
14779 if (!DT || DT->getDeducedType().isNull())
14780 continue;
14781 if (Deduced.isNull()) {
14782 Deduced = DT->getDeducedType();
14783 DeducedDecl = D;
14784 } else if (!Context.hasSameType(T1: DT->getDeducedType(), T2: Deduced)) {
14785 auto *AT = dyn_cast<AutoType>(Val: DT);
14786 auto Dia = Diag(Loc: D->getTypeSourceInfo()->getTypeLoc().getBeginLoc(),
14787 DiagID: diag::err_auto_different_deductions)
14788 << (AT ? (unsigned)AT->getKeyword() : 3) << Deduced
14789 << DeducedDecl->getDeclName() << DT->getDeducedType()
14790 << D->getDeclName();
14791 if (DeducedDecl->hasInit())
14792 Dia << DeducedDecl->getInit()->getSourceRange();
14793 if (D->getInit())
14794 Dia << D->getInit()->getSourceRange();
14795 D->setInvalidDecl();
14796 break;
14797 }
14798 }
14799 }
14800
14801 ActOnDocumentableDecls(Group);
14802
14803 return DeclGroupPtrTy::make(
14804 P: DeclGroupRef::Create(C&: Context, Decls: Group.data(), NumDecls: Group.size()));
14805}
14806
14807void Sema::ActOnDocumentableDecl(Decl *D) {
14808 ActOnDocumentableDecls(Group: D);
14809}
14810
14811void Sema::ActOnDocumentableDecls(ArrayRef<Decl *> Group) {
14812 // Don't parse the comment if Doxygen diagnostics are ignored.
14813 if (Group.empty() || !Group[0])
14814 return;
14815
14816 if (Diags.isIgnored(DiagID: diag::warn_doc_param_not_found,
14817 Loc: Group[0]->getLocation()) &&
14818 Diags.isIgnored(DiagID: diag::warn_unknown_comment_command_name,
14819 Loc: Group[0]->getLocation()))
14820 return;
14821
14822 if (Group.size() >= 2) {
14823 // This is a decl group. Normally it will contain only declarations
14824 // produced from declarator list. But in case we have any definitions or
14825 // additional declaration references:
14826 // 'typedef struct S {} S;'
14827 // 'typedef struct S *S;'
14828 // 'struct S *pS;'
14829 // FinalizeDeclaratorGroup adds these as separate declarations.
14830 Decl *MaybeTagDecl = Group[0];
14831 if (MaybeTagDecl && isa<TagDecl>(Val: MaybeTagDecl)) {
14832 Group = Group.slice(N: 1);
14833 }
14834 }
14835
14836 // FIMXE: We assume every Decl in the group is in the same file.
14837 // This is false when preprocessor constructs the group from decls in
14838 // different files (e. g. macros or #include).
14839 Context.attachCommentsToJustParsedDecls(Decls: Group, PP: &getPreprocessor());
14840}
14841
14842void Sema::CheckFunctionOrTemplateParamDeclarator(Scope *S, Declarator &D) {
14843 // Check that there are no default arguments inside the type of this
14844 // parameter.
14845 if (getLangOpts().CPlusPlus)
14846 CheckExtraCXXDefaultArguments(D);
14847
14848 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1).
14849 if (D.getCXXScopeSpec().isSet()) {
14850 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_qualified_param_declarator)
14851 << D.getCXXScopeSpec().getRange();
14852 }
14853
14854 // [dcl.meaning]p1: An unqualified-id occurring in a declarator-id shall be a
14855 // simple identifier except [...irrelevant cases...].
14856 switch (D.getName().getKind()) {
14857 case UnqualifiedIdKind::IK_Identifier:
14858 break;
14859
14860 case UnqualifiedIdKind::IK_OperatorFunctionId:
14861 case UnqualifiedIdKind::IK_ConversionFunctionId:
14862 case UnqualifiedIdKind::IK_LiteralOperatorId:
14863 case UnqualifiedIdKind::IK_ConstructorName:
14864 case UnqualifiedIdKind::IK_DestructorName:
14865 case UnqualifiedIdKind::IK_ImplicitSelfParam:
14866 case UnqualifiedIdKind::IK_DeductionGuideName:
14867 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_bad_parameter_name)
14868 << GetNameForDeclarator(D).getName();
14869 break;
14870
14871 case UnqualifiedIdKind::IK_TemplateId:
14872 case UnqualifiedIdKind::IK_ConstructorTemplateId:
14873 // GetNameForDeclarator would not produce a useful name in this case.
14874 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_bad_parameter_name_template_id);
14875 break;
14876 }
14877}
14878
14879static void CheckExplicitObjectParameter(Sema &S, ParmVarDecl *P,
14880 SourceLocation ExplicitThisLoc) {
14881 if (!ExplicitThisLoc.isValid())
14882 return;
14883 assert(S.getLangOpts().CPlusPlus &&
14884 "explicit parameter in non-cplusplus mode");
14885 if (!S.getLangOpts().CPlusPlus23)
14886 S.Diag(Loc: ExplicitThisLoc, DiagID: diag::err_cxx20_deducing_this)
14887 << P->getSourceRange();
14888
14889 // C++2b [dcl.fct/7] An explicit object parameter shall not be a function
14890 // parameter pack.
14891 if (P->isParameterPack()) {
14892 S.Diag(Loc: P->getBeginLoc(), DiagID: diag::err_explicit_object_parameter_pack)
14893 << P->getSourceRange();
14894 return;
14895 }
14896 P->setExplicitObjectParameterLoc(ExplicitThisLoc);
14897 if (LambdaScopeInfo *LSI = S.getCurLambda())
14898 LSI->ExplicitObjectParameter = P;
14899}
14900
14901Decl *Sema::ActOnParamDeclarator(Scope *S, Declarator &D,
14902 SourceLocation ExplicitThisLoc) {
14903 const DeclSpec &DS = D.getDeclSpec();
14904
14905 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'.
14906
14907 // C++03 [dcl.stc]p2 also permits 'auto'.
14908 StorageClass SC = SC_None;
14909 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) {
14910 SC = SC_Register;
14911 // In C++11, the 'register' storage class specifier is deprecated.
14912 // In C++17, it is not allowed, but we tolerate it as an extension.
14913 if (getLangOpts().CPlusPlus11) {
14914 Diag(Loc: DS.getStorageClassSpecLoc(),
14915 DiagID: getLangOpts().CPlusPlus17 ? diag::ext_register_storage_class
14916 : diag::warn_deprecated_register)
14917 << FixItHint::CreateRemoval(RemoveRange: DS.getStorageClassSpecLoc());
14918 }
14919 } else if (getLangOpts().CPlusPlus &&
14920 DS.getStorageClassSpec() == DeclSpec::SCS_auto) {
14921 SC = SC_Auto;
14922 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) {
14923 Diag(Loc: DS.getStorageClassSpecLoc(),
14924 DiagID: diag::err_invalid_storage_class_in_func_decl);
14925 D.getMutableDeclSpec().ClearStorageClassSpecs();
14926 }
14927
14928 if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec())
14929 Diag(Loc: DS.getThreadStorageClassSpecLoc(), DiagID: diag::err_invalid_thread)
14930 << DeclSpec::getSpecifierName(S: TSCS);
14931 if (DS.isInlineSpecified())
14932 Diag(Loc: DS.getInlineSpecLoc(), DiagID: diag::err_inline_non_function)
14933 << getLangOpts().CPlusPlus17;
14934 if (DS.hasConstexprSpecifier())
14935 Diag(Loc: DS.getConstexprSpecLoc(), DiagID: diag::err_invalid_constexpr)
14936 << 0 << static_cast<int>(D.getDeclSpec().getConstexprSpecifier());
14937
14938 DiagnoseFunctionSpecifiers(DS);
14939
14940 CheckFunctionOrTemplateParamDeclarator(S, D);
14941
14942 TypeSourceInfo *TInfo = GetTypeForDeclarator(D);
14943 QualType parmDeclType = TInfo->getType();
14944
14945 // Check for redeclaration of parameters, e.g. int foo(int x, int x);
14946 const IdentifierInfo *II = D.getIdentifier();
14947 if (II) {
14948 LookupResult R(*this, II, D.getIdentifierLoc(), LookupOrdinaryName,
14949 RedeclarationKind::ForVisibleRedeclaration);
14950 LookupName(R, S);
14951 if (!R.empty()) {
14952 NamedDecl *PrevDecl = *R.begin();
14953 if (R.isSingleResult() && PrevDecl->isTemplateParameter()) {
14954 // Maybe we will complain about the shadowed template parameter.
14955 DiagnoseTemplateParameterShadow(Loc: D.getIdentifierLoc(), PrevDecl);
14956 // Just pretend that we didn't see the previous declaration.
14957 PrevDecl = nullptr;
14958 }
14959 if (PrevDecl && S->isDeclScope(D: PrevDecl)) {
14960 Diag(Loc: D.getIdentifierLoc(), DiagID: diag::err_param_redefinition) << II;
14961 Diag(Loc: PrevDecl->getLocation(), DiagID: diag::note_previous_declaration);
14962 // Recover by removing the name
14963 II = nullptr;
14964 D.SetIdentifier(Id: nullptr, IdLoc: D.getIdentifierLoc());
14965 D.setInvalidType(true);
14966 }
14967 }
14968 }
14969
14970 // Temporarily put parameter variables in the translation unit, not
14971 // the enclosing context. This prevents them from accidentally
14972 // looking like class members in C++.
14973 ParmVarDecl *New =
14974 CheckParameter(DC: Context.getTranslationUnitDecl(), StartLoc: D.getBeginLoc(),
14975 NameLoc: D.getIdentifierLoc(), Name: II, T: parmDeclType, TSInfo: TInfo, SC);
14976
14977 if (D.isInvalidType())
14978 New->setInvalidDecl();
14979
14980 CheckExplicitObjectParameter(S&: *this, P: New, ExplicitThisLoc);
14981
14982 assert(S->isFunctionPrototypeScope());
14983 assert(S->getFunctionPrototypeDepth() >= 1);
14984 New->setScopeInfo(scopeDepth: S->getFunctionPrototypeDepth() - 1,
14985 parameterIndex: S->getNextFunctionPrototypeIndex());
14986
14987 // Add the parameter declaration into this scope.
14988 S->AddDecl(D: New);
14989 if (II)
14990 IdResolver.AddDecl(D: New);
14991
14992 ProcessDeclAttributes(S, D: New, PD: D);
14993
14994 if (D.getDeclSpec().isModulePrivateSpecified())
14995 Diag(Loc: New->getLocation(), DiagID: diag::err_module_private_local)
14996 << 1 << New << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
14997 << FixItHint::CreateRemoval(RemoveRange: D.getDeclSpec().getModulePrivateSpecLoc());
14998
14999 if (New->hasAttr<BlocksAttr>()) {
15000 Diag(Loc: New->getLocation(), DiagID: diag::err_block_on_nonlocal);
15001 }
15002
15003 if (getLangOpts().OpenCL)
15004 deduceOpenCLAddressSpace(Decl: New);
15005
15006 return New;
15007}
15008
15009ParmVarDecl *Sema::BuildParmVarDeclForTypedef(DeclContext *DC,
15010 SourceLocation Loc,
15011 QualType T) {
15012 /* FIXME: setting StartLoc == Loc.
15013 Would it be worth to modify callers so as to provide proper source
15014 location for the unnamed parameters, embedding the parameter's type? */
15015 ParmVarDecl *Param = ParmVarDecl::Create(C&: Context, DC, StartLoc: Loc, IdLoc: Loc, Id: nullptr,
15016 T, TInfo: Context.getTrivialTypeSourceInfo(T, Loc),
15017 S: SC_None, DefArg: nullptr);
15018 Param->setImplicit();
15019 return Param;
15020}
15021
15022void Sema::DiagnoseUnusedParameters(ArrayRef<ParmVarDecl *> Parameters) {
15023 // Don't diagnose unused-parameter errors in template instantiations; we
15024 // will already have done so in the template itself.
15025 if (inTemplateInstantiation())
15026 return;
15027
15028 for (const ParmVarDecl *Parameter : Parameters) {
15029 if (!Parameter->isReferenced() && Parameter->getDeclName() &&
15030 !Parameter->hasAttr<UnusedAttr>() &&
15031 !Parameter->getIdentifier()->isPlaceholder()) {
15032 Diag(Loc: Parameter->getLocation(), DiagID: diag::warn_unused_parameter)
15033 << Parameter->getDeclName();
15034 }
15035 }
15036}
15037
15038void Sema::DiagnoseSizeOfParametersAndReturnValue(
15039 ArrayRef<ParmVarDecl *> Parameters, QualType ReturnTy, NamedDecl *D) {
15040 if (LangOpts.NumLargeByValueCopy == 0) // No check.
15041 return;
15042
15043 // Warn if the return value is pass-by-value and larger than the specified
15044 // threshold.
15045 if (!ReturnTy->isDependentType() && ReturnTy.isPODType(Context)) {
15046 unsigned Size = Context.getTypeSizeInChars(T: ReturnTy).getQuantity();
15047 if (Size > LangOpts.NumLargeByValueCopy)
15048 Diag(Loc: D->getLocation(), DiagID: diag::warn_return_value_size) << D << Size;
15049 }
15050
15051 // Warn if any parameter is pass-by-value and larger than the specified
15052 // threshold.
15053 for (const ParmVarDecl *Parameter : Parameters) {
15054 QualType T = Parameter->getType();
15055 if (T->isDependentType() || !T.isPODType(Context))
15056 continue;
15057 unsigned Size = Context.getTypeSizeInChars(T).getQuantity();
15058 if (Size > LangOpts.NumLargeByValueCopy)
15059 Diag(Loc: Parameter->getLocation(), DiagID: diag::warn_parameter_size)
15060 << Parameter << Size;
15061 }
15062}
15063
15064ParmVarDecl *Sema::CheckParameter(DeclContext *DC, SourceLocation StartLoc,
15065 SourceLocation NameLoc,
15066 const IdentifierInfo *Name, QualType T,
15067 TypeSourceInfo *TSInfo, StorageClass SC) {
15068 // In ARC, infer a lifetime qualifier for appropriate parameter types.
15069 if (getLangOpts().ObjCAutoRefCount &&
15070 T.getObjCLifetime() == Qualifiers::OCL_None &&
15071 T->isObjCLifetimeType()) {
15072
15073 Qualifiers::ObjCLifetime lifetime;
15074
15075 // Special cases for arrays:
15076 // - if it's const, use __unsafe_unretained
15077 // - otherwise, it's an error
15078 if (T->isArrayType()) {
15079 if (!T.isConstQualified()) {
15080 if (DelayedDiagnostics.shouldDelayDiagnostics())
15081 DelayedDiagnostics.add(
15082 diag: sema::DelayedDiagnostic::makeForbiddenType(
15083 loc: NameLoc, diagnostic: diag::err_arc_array_param_no_ownership, type: T, argument: false));
15084 else
15085 Diag(Loc: NameLoc, DiagID: diag::err_arc_array_param_no_ownership)
15086 << TSInfo->getTypeLoc().getSourceRange();
15087 }
15088 lifetime = Qualifiers::OCL_ExplicitNone;
15089 } else {
15090 lifetime = T->getObjCARCImplicitLifetime();
15091 }
15092 T = Context.getLifetimeQualifiedType(type: T, lifetime);
15093 }
15094
15095 ParmVarDecl *New = ParmVarDecl::Create(C&: Context, DC, StartLoc, IdLoc: NameLoc, Id: Name,
15096 T: Context.getAdjustedParameterType(T),
15097 TInfo: TSInfo, S: SC, DefArg: nullptr);
15098
15099 // Make a note if we created a new pack in the scope of a lambda, so that
15100 // we know that references to that pack must also be expanded within the
15101 // lambda scope.
15102 if (New->isParameterPack())
15103 if (auto *LSI = getEnclosingLambda())
15104 LSI->LocalPacks.push_back(Elt: New);
15105
15106 if (New->getType().hasNonTrivialToPrimitiveDestructCUnion() ||
15107 New->getType().hasNonTrivialToPrimitiveCopyCUnion())
15108 checkNonTrivialCUnion(QT: New->getType(), Loc: New->getLocation(),
15109 UseContext: NTCUC_FunctionParam, NonTrivialKind: NTCUK_Destruct|NTCUK_Copy);
15110
15111 // Parameter declarators cannot be interface types. All ObjC objects are
15112 // passed by reference.
15113 if (T->isObjCObjectType()) {
15114 SourceLocation TypeEndLoc =
15115 getLocForEndOfToken(Loc: TSInfo->getTypeLoc().getEndLoc());
15116 Diag(Loc: NameLoc,
15117 DiagID: diag::err_object_cannot_be_passed_returned_by_value) << 1 << T
15118 << FixItHint::CreateInsertion(InsertionLoc: TypeEndLoc, Code: "*");
15119 T = Context.getObjCObjectPointerType(OIT: T);
15120 New->setType(T);
15121 }
15122
15123 // ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage
15124 // duration shall not be qualified by an address-space qualifier."
15125 // Since all parameters have automatic store duration, they can not have
15126 // an address space.
15127 if (T.getAddressSpace() != LangAS::Default &&
15128 // OpenCL allows function arguments declared to be an array of a type
15129 // to be qualified with an address space.
15130 !(getLangOpts().OpenCL &&
15131 (T->isArrayType() || T.getAddressSpace() == LangAS::opencl_private)) &&
15132 // WebAssembly allows reference types as parameters. Funcref in particular
15133 // lives in a different address space.
15134 !(T->isFunctionPointerType() &&
15135 T.getAddressSpace() == LangAS::wasm_funcref)) {
15136 Diag(Loc: NameLoc, DiagID: diag::err_arg_with_address_space);
15137 New->setInvalidDecl();
15138 }
15139
15140 // PPC MMA non-pointer types are not allowed as function argument types.
15141 if (Context.getTargetInfo().getTriple().isPPC64() &&
15142 PPC().CheckPPCMMAType(Type: New->getOriginalType(), TypeLoc: New->getLocation())) {
15143 New->setInvalidDecl();
15144 }
15145
15146 return New;
15147}
15148
15149void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D,
15150 SourceLocation LocAfterDecls) {
15151 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
15152
15153 // C99 6.9.1p6 "If a declarator includes an identifier list, each declaration
15154 // in the declaration list shall have at least one declarator, those
15155 // declarators shall only declare identifiers from the identifier list, and
15156 // every identifier in the identifier list shall be declared.
15157 //
15158 // C89 3.7.1p5 "If a declarator includes an identifier list, only the
15159 // identifiers it names shall be declared in the declaration list."
15160 //
15161 // This is why we only diagnose in C99 and later. Note, the other conditions
15162 // listed are checked elsewhere.
15163 if (!FTI.hasPrototype) {
15164 for (int i = FTI.NumParams; i != 0; /* decrement in loop */) {
15165 --i;
15166 if (FTI.Params[i].Param == nullptr) {
15167 if (getLangOpts().C99) {
15168 SmallString<256> Code;
15169 llvm::raw_svector_ostream(Code)
15170 << " int " << FTI.Params[i].Ident->getName() << ";\n";
15171 Diag(Loc: FTI.Params[i].IdentLoc, DiagID: diag::ext_param_not_declared)
15172 << FTI.Params[i].Ident
15173 << FixItHint::CreateInsertion(InsertionLoc: LocAfterDecls, Code);
15174 }
15175
15176 // Implicitly declare the argument as type 'int' for lack of a better
15177 // type.
15178 AttributeFactory attrs;
15179 DeclSpec DS(attrs);
15180 const char* PrevSpec; // unused
15181 unsigned DiagID; // unused
15182 DS.SetTypeSpecType(T: DeclSpec::TST_int, Loc: FTI.Params[i].IdentLoc, PrevSpec,
15183 DiagID, Policy: Context.getPrintingPolicy());
15184 // Use the identifier location for the type source range.
15185 DS.SetRangeStart(FTI.Params[i].IdentLoc);
15186 DS.SetRangeEnd(FTI.Params[i].IdentLoc);
15187 Declarator ParamD(DS, ParsedAttributesView::none(),
15188 DeclaratorContext::KNRTypeList);
15189 ParamD.SetIdentifier(Id: FTI.Params[i].Ident, IdLoc: FTI.Params[i].IdentLoc);
15190 FTI.Params[i].Param = ActOnParamDeclarator(S, D&: ParamD);
15191 }
15192 }
15193 }
15194}
15195
15196Decl *
15197Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D,
15198 MultiTemplateParamsArg TemplateParameterLists,
15199 SkipBodyInfo *SkipBody, FnBodyKind BodyKind) {
15200 assert(getCurFunctionDecl() == nullptr && "Function parsing confused");
15201 assert(D.isFunctionDeclarator() && "Not a function declarator!");
15202 Scope *ParentScope = FnBodyScope->getParent();
15203
15204 // Check if we are in an `omp begin/end declare variant` scope. If we are, and
15205 // we define a non-templated function definition, we will create a declaration
15206 // instead (=BaseFD), and emit the definition with a mangled name afterwards.
15207 // The base function declaration will have the equivalent of an `omp declare
15208 // variant` annotation which specifies the mangled definition as a
15209 // specialization function under the OpenMP context defined as part of the
15210 // `omp begin declare variant`.
15211 SmallVector<FunctionDecl *, 4> Bases;
15212 if (LangOpts.OpenMP && OpenMP().isInOpenMPDeclareVariantScope())
15213 OpenMP().ActOnStartOfFunctionDefinitionInOpenMPDeclareVariantScope(
15214 S: ParentScope, D, TemplateParameterLists, Bases);
15215
15216 D.setFunctionDefinitionKind(FunctionDefinitionKind::Definition);
15217 Decl *DP = HandleDeclarator(S: ParentScope, D, TemplateParamLists: TemplateParameterLists);
15218 Decl *Dcl = ActOnStartOfFunctionDef(S: FnBodyScope, D: DP, SkipBody, BodyKind);
15219
15220 if (!Bases.empty())
15221 OpenMP().ActOnFinishedFunctionDefinitionInOpenMPDeclareVariantScope(D: Dcl,
15222 Bases);
15223
15224 return Dcl;
15225}
15226
15227void Sema::ActOnFinishInlineFunctionDef(FunctionDecl *D) {
15228 Consumer.HandleInlineFunctionDefinition(D);
15229}
15230
15231static bool FindPossiblePrototype(const FunctionDecl *FD,
15232 const FunctionDecl *&PossiblePrototype) {
15233 for (const FunctionDecl *Prev = FD->getPreviousDecl(); Prev;
15234 Prev = Prev->getPreviousDecl()) {
15235 // Ignore any declarations that occur in function or method
15236 // scope, because they aren't visible from the header.
15237 if (Prev->getLexicalDeclContext()->isFunctionOrMethod())
15238 continue;
15239
15240 PossiblePrototype = Prev;
15241 return Prev->getType()->isFunctionProtoType();
15242 }
15243 return false;
15244}
15245
15246static bool
15247ShouldWarnAboutMissingPrototype(const FunctionDecl *FD,
15248 const FunctionDecl *&PossiblePrototype) {
15249 // Don't warn about invalid declarations.
15250 if (FD->isInvalidDecl())
15251 return false;
15252
15253 // Or declarations that aren't global.
15254 if (!FD->isGlobal())
15255 return false;
15256
15257 // Don't warn about C++ member functions.
15258 if (isa<CXXMethodDecl>(Val: FD))
15259 return false;
15260
15261 // Don't warn about 'main'.
15262 if (isa<TranslationUnitDecl>(Val: FD->getDeclContext()->getRedeclContext()))
15263 if (IdentifierInfo *II = FD->getIdentifier())
15264 if (II->isStr(Str: "main") || II->isStr(Str: "efi_main"))
15265 return false;
15266
15267 if (FD->isMSVCRTEntryPoint())
15268 return false;
15269
15270 // Don't warn about inline functions.
15271 if (FD->isInlined())
15272 return false;
15273
15274 // Don't warn about function templates.
15275 if (FD->getDescribedFunctionTemplate())
15276 return false;
15277
15278 // Don't warn about function template specializations.
15279 if (FD->isFunctionTemplateSpecialization())
15280 return false;
15281
15282 // Don't warn for OpenCL kernels.
15283 if (FD->hasAttr<OpenCLKernelAttr>())
15284 return false;
15285
15286 // Don't warn on explicitly deleted functions.
15287 if (FD->isDeleted())
15288 return false;
15289
15290 // Don't warn on implicitly local functions (such as having local-typed
15291 // parameters).
15292 if (!FD->isExternallyVisible())
15293 return false;
15294
15295 // If we were able to find a potential prototype, don't warn.
15296 if (FindPossiblePrototype(FD, PossiblePrototype))
15297 return false;
15298
15299 return true;
15300}
15301
15302void
15303Sema::CheckForFunctionRedefinition(FunctionDecl *FD,
15304 const FunctionDecl *EffectiveDefinition,
15305 SkipBodyInfo *SkipBody) {
15306 const FunctionDecl *Definition = EffectiveDefinition;
15307 if (!Definition &&
15308 !FD->isDefined(Definition, /*CheckForPendingFriendDefinition*/ true))
15309 return;
15310
15311 if (Definition->getFriendObjectKind() != Decl::FOK_None) {
15312 if (FunctionDecl *OrigDef = Definition->getInstantiatedFromMemberFunction()) {
15313 if (FunctionDecl *OrigFD = FD->getInstantiatedFromMemberFunction()) {
15314 // A merged copy of the same function, instantiated as a member of
15315 // the same class, is OK.
15316 if (declaresSameEntity(D1: OrigFD, D2: OrigDef) &&
15317 declaresSameEntity(D1: cast<Decl>(Val: Definition->getLexicalDeclContext()),
15318 D2: cast<Decl>(Val: FD->getLexicalDeclContext())))
15319 return;
15320 }
15321 }
15322 }
15323
15324 if (canRedefineFunction(FD: Definition, LangOpts: getLangOpts()))
15325 return;
15326
15327 // Don't emit an error when this is redefinition of a typo-corrected
15328 // definition.
15329 if (TypoCorrectedFunctionDefinitions.count(Ptr: Definition))
15330 return;
15331
15332 // If we don't have a visible definition of the function, and it's inline or
15333 // a template, skip the new definition.
15334 if (SkipBody && !hasVisibleDefinition(D: Definition) &&
15335 (Definition->getFormalLinkage() == Linkage::Internal ||
15336 Definition->isInlined() || Definition->getDescribedFunctionTemplate() ||
15337 Definition->getNumTemplateParameterLists())) {
15338 SkipBody->ShouldSkip = true;
15339 SkipBody->Previous = const_cast<FunctionDecl*>(Definition);
15340 if (auto *TD = Definition->getDescribedFunctionTemplate())
15341 makeMergedDefinitionVisible(ND: TD);
15342 makeMergedDefinitionVisible(ND: const_cast<FunctionDecl*>(Definition));
15343 return;
15344 }
15345
15346 if (getLangOpts().GNUMode && Definition->isInlineSpecified() &&
15347 Definition->getStorageClass() == SC_Extern)
15348 Diag(Loc: FD->getLocation(), DiagID: diag::err_redefinition_extern_inline)
15349 << FD << getLangOpts().CPlusPlus;
15350 else
15351 Diag(Loc: FD->getLocation(), DiagID: diag::err_redefinition) << FD;
15352
15353 Diag(Loc: Definition->getLocation(), DiagID: diag::note_previous_definition);
15354 FD->setInvalidDecl();
15355}
15356
15357LambdaScopeInfo *Sema::RebuildLambdaScopeInfo(CXXMethodDecl *CallOperator) {
15358 CXXRecordDecl *LambdaClass = CallOperator->getParent();
15359
15360 LambdaScopeInfo *LSI = PushLambdaScope();
15361 LSI->CallOperator = CallOperator;
15362 LSI->Lambda = LambdaClass;
15363 LSI->ReturnType = CallOperator->getReturnType();
15364 // This function in calls in situation where the context of the call operator
15365 // is not entered, so we set AfterParameterList to false, so that
15366 // `tryCaptureVariable` finds explicit captures in the appropriate context.
15367 LSI->AfterParameterList = false;
15368 const LambdaCaptureDefault LCD = LambdaClass->getLambdaCaptureDefault();
15369
15370 if (LCD == LCD_None)
15371 LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_None;
15372 else if (LCD == LCD_ByCopy)
15373 LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_LambdaByval;
15374 else if (LCD == LCD_ByRef)
15375 LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_LambdaByref;
15376 DeclarationNameInfo DNI = CallOperator->getNameInfo();
15377
15378 LSI->IntroducerRange = DNI.getCXXOperatorNameRange();
15379 LSI->Mutable = !CallOperator->isConst();
15380 if (CallOperator->isExplicitObjectMemberFunction())
15381 LSI->ExplicitObjectParameter = CallOperator->getParamDecl(i: 0);
15382
15383 // Add the captures to the LSI so they can be noted as already
15384 // captured within tryCaptureVar.
15385 auto I = LambdaClass->field_begin();
15386 for (const auto &C : LambdaClass->captures()) {
15387 if (C.capturesVariable()) {
15388 ValueDecl *VD = C.getCapturedVar();
15389 if (VD->isInitCapture())
15390 CurrentInstantiationScope->InstantiatedLocal(D: VD, Inst: VD);
15391 const bool ByRef = C.getCaptureKind() == LCK_ByRef;
15392 LSI->addCapture(Var: VD, /*IsBlock*/isBlock: false, isByref: ByRef,
15393 /*RefersToEnclosingVariableOrCapture*/isNested: true, Loc: C.getLocation(),
15394 /*EllipsisLoc*/C.isPackExpansion()
15395 ? C.getEllipsisLoc() : SourceLocation(),
15396 CaptureType: I->getType(), /*Invalid*/false);
15397
15398 } else if (C.capturesThis()) {
15399 LSI->addThisCapture(/*Nested*/ isNested: false, Loc: C.getLocation(), CaptureType: I->getType(),
15400 ByCopy: C.getCaptureKind() == LCK_StarThis);
15401 } else {
15402 LSI->addVLATypeCapture(Loc: C.getLocation(), VLAType: I->getCapturedVLAType(),
15403 CaptureType: I->getType());
15404 }
15405 ++I;
15406 }
15407 return LSI;
15408}
15409
15410Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
15411 SkipBodyInfo *SkipBody,
15412 FnBodyKind BodyKind) {
15413 if (!D) {
15414 // Parsing the function declaration failed in some way. Push on a fake scope
15415 // anyway so we can try to parse the function body.
15416 PushFunctionScope();
15417 PushExpressionEvaluationContext(NewContext: ExprEvalContexts.back().Context);
15418 return D;
15419 }
15420
15421 FunctionDecl *FD = nullptr;
15422
15423 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Val: D))
15424 FD = FunTmpl->getTemplatedDecl();
15425 else
15426 FD = cast<FunctionDecl>(Val: D);
15427
15428 // Do not push if it is a lambda because one is already pushed when building
15429 // the lambda in ActOnStartOfLambdaDefinition().
15430 if (!isLambdaCallOperator(DC: FD))
15431 // [expr.const]/p14.1
15432 // An expression or conversion is in an immediate function context if it is
15433 // potentially evaluated and either: its innermost enclosing non-block scope
15434 // is a function parameter scope of an immediate function.
15435 PushExpressionEvaluationContext(
15436 NewContext: FD->isConsteval() ? ExpressionEvaluationContext::ImmediateFunctionContext
15437 : ExprEvalContexts.back().Context);
15438
15439 // Each ExpressionEvaluationContextRecord also keeps track of whether the
15440 // context is nested in an immediate function context, so smaller contexts
15441 // that appear inside immediate functions (like variable initializers) are
15442 // considered to be inside an immediate function context even though by
15443 // themselves they are not immediate function contexts. But when a new
15444 // function is entered, we need to reset this tracking, since the entered
15445 // function might be not an immediate function.
15446 ExprEvalContexts.back().InImmediateFunctionContext = FD->isConsteval();
15447 ExprEvalContexts.back().InImmediateEscalatingFunctionContext =
15448 getLangOpts().CPlusPlus20 && FD->isImmediateEscalating();
15449
15450 // Check for defining attributes before the check for redefinition.
15451 if (const auto *Attr = FD->getAttr<AliasAttr>()) {
15452 Diag(Loc: Attr->getLocation(), DiagID: diag::err_alias_is_definition) << FD << 0;
15453 FD->dropAttr<AliasAttr>();
15454 FD->setInvalidDecl();
15455 }
15456 if (const auto *Attr = FD->getAttr<IFuncAttr>()) {
15457 Diag(Loc: Attr->getLocation(), DiagID: diag::err_alias_is_definition) << FD << 1;
15458 FD->dropAttr<IFuncAttr>();
15459 FD->setInvalidDecl();
15460 }
15461 if (const auto *Attr = FD->getAttr<TargetVersionAttr>()) {
15462 if (!Context.getTargetInfo().hasFeature(Feature: "fmv") &&
15463 !Attr->isDefaultVersion()) {
15464 // If function multi versioning disabled skip parsing function body
15465 // defined with non-default target_version attribute
15466 if (SkipBody)
15467 SkipBody->ShouldSkip = true;
15468 return nullptr;
15469 }
15470 }
15471
15472 if (auto *Ctor = dyn_cast<CXXConstructorDecl>(Val: FD)) {
15473 if (Ctor->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
15474 Ctor->isDefaultConstructor() &&
15475 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
15476 // If this is an MS ABI dllexport default constructor, instantiate any
15477 // default arguments.
15478 InstantiateDefaultCtorDefaultArgs(Ctor);
15479 }
15480 }
15481
15482 // See if this is a redefinition. If 'will have body' (or similar) is already
15483 // set, then these checks were already performed when it was set.
15484 if (!FD->willHaveBody() && !FD->isLateTemplateParsed() &&
15485 !FD->isThisDeclarationInstantiatedFromAFriendDefinition()) {
15486 CheckForFunctionRedefinition(FD, EffectiveDefinition: nullptr, SkipBody);
15487
15488 // If we're skipping the body, we're done. Don't enter the scope.
15489 if (SkipBody && SkipBody->ShouldSkip)
15490 return D;
15491 }
15492
15493 // Mark this function as "will have a body eventually". This lets users to
15494 // call e.g. isInlineDefinitionExternallyVisible while we're still parsing
15495 // this function.
15496 FD->setWillHaveBody();
15497
15498 // If we are instantiating a generic lambda call operator, push
15499 // a LambdaScopeInfo onto the function stack. But use the information
15500 // that's already been calculated (ActOnLambdaExpr) to prime the current
15501 // LambdaScopeInfo.
15502 // When the template operator is being specialized, the LambdaScopeInfo,
15503 // has to be properly restored so that tryCaptureVariable doesn't try
15504 // and capture any new variables. In addition when calculating potential
15505 // captures during transformation of nested lambdas, it is necessary to
15506 // have the LSI properly restored.
15507 if (isGenericLambdaCallOperatorSpecialization(DC: FD)) {
15508 // C++2c 7.5.5.2p17 A member of a closure type shall not be explicitly
15509 // instantiated, explicitly specialized.
15510 if (FD->getTemplateSpecializationInfo()
15511 ->isExplicitInstantiationOrSpecialization()) {
15512 Diag(Loc: FD->getLocation(), DiagID: diag::err_lambda_explicit_spec);
15513 FD->setInvalidDecl();
15514 PushFunctionScope();
15515 } else {
15516 assert(inTemplateInstantiation() &&
15517 "There should be an active template instantiation on the stack "
15518 "when instantiating a generic lambda!");
15519 RebuildLambdaScopeInfo(CallOperator: cast<CXXMethodDecl>(Val: D));
15520 }
15521 } else {
15522 // Enter a new function scope
15523 PushFunctionScope();
15524 }
15525
15526 // Builtin functions cannot be defined.
15527 if (unsigned BuiltinID = FD->getBuiltinID()) {
15528 if (!Context.BuiltinInfo.isPredefinedLibFunction(ID: BuiltinID) &&
15529 !Context.BuiltinInfo.isPredefinedRuntimeFunction(ID: BuiltinID)) {
15530 Diag(Loc: FD->getLocation(), DiagID: diag::err_builtin_definition) << FD;
15531 FD->setInvalidDecl();
15532 }
15533 }
15534
15535 // The return type of a function definition must be complete (C99 6.9.1p3).
15536 // C++23 [dcl.fct.def.general]/p2
15537 // The type of [...] the return for a function definition
15538 // shall not be a (possibly cv-qualified) class type that is incomplete
15539 // or abstract within the function body unless the function is deleted.
15540 QualType ResultType = FD->getReturnType();
15541 if (!ResultType->isDependentType() && !ResultType->isVoidType() &&
15542 !FD->isInvalidDecl() && BodyKind != FnBodyKind::Delete &&
15543 (RequireCompleteType(Loc: FD->getLocation(), T: ResultType,
15544 DiagID: diag::err_func_def_incomplete_result) ||
15545 RequireNonAbstractType(Loc: FD->getLocation(), T: FD->getReturnType(),
15546 DiagID: diag::err_abstract_type_in_decl,
15547 Args: AbstractReturnType)))
15548 FD->setInvalidDecl();
15549
15550 if (FnBodyScope)
15551 PushDeclContext(S: FnBodyScope, DC: FD);
15552
15553 // Check the validity of our function parameters
15554 if (BodyKind != FnBodyKind::Delete)
15555 CheckParmsForFunctionDef(Parameters: FD->parameters(),
15556 /*CheckParameterNames=*/true);
15557
15558 // Add non-parameter declarations already in the function to the current
15559 // scope.
15560 if (FnBodyScope) {
15561 for (Decl *NPD : FD->decls()) {
15562 auto *NonParmDecl = dyn_cast<NamedDecl>(Val: NPD);
15563 if (!NonParmDecl)
15564 continue;
15565 assert(!isa<ParmVarDecl>(NonParmDecl) &&
15566 "parameters should not be in newly created FD yet");
15567
15568 // If the decl has a name, make it accessible in the current scope.
15569 if (NonParmDecl->getDeclName())
15570 PushOnScopeChains(D: NonParmDecl, S: FnBodyScope, /*AddToContext=*/false);
15571
15572 // Similarly, dive into enums and fish their constants out, making them
15573 // accessible in this scope.
15574 if (auto *ED = dyn_cast<EnumDecl>(Val: NonParmDecl)) {
15575 for (auto *EI : ED->enumerators())
15576 PushOnScopeChains(D: EI, S: FnBodyScope, /*AddToContext=*/false);
15577 }
15578 }
15579 }
15580
15581 // Introduce our parameters into the function scope
15582 for (auto *Param : FD->parameters()) {
15583 Param->setOwningFunction(FD);
15584
15585 // If this has an identifier, add it to the scope stack.
15586 if (Param->getIdentifier() && FnBodyScope) {
15587 CheckShadow(S: FnBodyScope, D: Param);
15588
15589 PushOnScopeChains(D: Param, S: FnBodyScope);
15590 }
15591 }
15592
15593 // C++ [module.import/6] external definitions are not permitted in header
15594 // units. Deleted and Defaulted functions are implicitly inline (but the
15595 // inline state is not set at this point, so check the BodyKind explicitly).
15596 // FIXME: Consider an alternate location for the test where the inlined()
15597 // state is complete.
15598 if (getLangOpts().CPlusPlusModules && currentModuleIsHeaderUnit() &&
15599 !FD->isInvalidDecl() && !FD->isInlined() &&
15600 BodyKind != FnBodyKind::Delete && BodyKind != FnBodyKind::Default &&
15601 FD->getFormalLinkage() == Linkage::External && !FD->isTemplated() &&
15602 !FD->isTemplateInstantiation()) {
15603 assert(FD->isThisDeclarationADefinition());
15604 Diag(Loc: FD->getLocation(), DiagID: diag::err_extern_def_in_header_unit);
15605 FD->setInvalidDecl();
15606 }
15607
15608 // Ensure that the function's exception specification is instantiated.
15609 if (const FunctionProtoType *FPT = FD->getType()->getAs<FunctionProtoType>())
15610 ResolveExceptionSpec(Loc: D->getLocation(), FPT);
15611
15612 // dllimport cannot be applied to non-inline function definitions.
15613 if (FD->hasAttr<DLLImportAttr>() && !FD->isInlined() &&
15614 !FD->isTemplateInstantiation()) {
15615 assert(!FD->hasAttr<DLLExportAttr>());
15616 Diag(Loc: FD->getLocation(), DiagID: diag::err_attribute_dllimport_function_definition);
15617 FD->setInvalidDecl();
15618 return D;
15619 }
15620
15621 // Some function attributes (like OptimizeNoneAttr) need actions before
15622 // parsing body started.
15623 applyFunctionAttributesBeforeParsingBody(FD: D);
15624
15625 // We want to attach documentation to original Decl (which might be
15626 // a function template).
15627 ActOnDocumentableDecl(D);
15628 if (getCurLexicalContext()->isObjCContainer() &&
15629 getCurLexicalContext()->getDeclKind() != Decl::ObjCCategoryImpl &&
15630 getCurLexicalContext()->getDeclKind() != Decl::ObjCImplementation)
15631 Diag(Loc: FD->getLocation(), DiagID: diag::warn_function_def_in_objc_container);
15632
15633 return D;
15634}
15635
15636void Sema::applyFunctionAttributesBeforeParsingBody(Decl *FD) {
15637 if (!FD || FD->isInvalidDecl())
15638 return;
15639 if (auto *TD = dyn_cast<FunctionTemplateDecl>(Val: FD))
15640 FD = TD->getTemplatedDecl();
15641 if (FD && FD->hasAttr<OptimizeNoneAttr>()) {
15642 FPOptionsOverride FPO;
15643 FPO.setDisallowOptimizations();
15644 CurFPFeatures.applyChanges(FPO);
15645 FpPragmaStack.CurrentValue =
15646 CurFPFeatures.getChangesFrom(Base: FPOptions(LangOpts));
15647 }
15648}
15649
15650void Sema::computeNRVO(Stmt *Body, FunctionScopeInfo *Scope) {
15651 ReturnStmt **Returns = Scope->Returns.data();
15652
15653 for (unsigned I = 0, E = Scope->Returns.size(); I != E; ++I) {
15654 if (const VarDecl *NRVOCandidate = Returns[I]->getNRVOCandidate()) {
15655 if (!NRVOCandidate->isNRVOVariable())
15656 Returns[I]->setNRVOCandidate(nullptr);
15657 }
15658 }
15659}
15660
15661bool Sema::canDelayFunctionBody(const Declarator &D) {
15662 // We can't delay parsing the body of a constexpr function template (yet).
15663 if (D.getDeclSpec().hasConstexprSpecifier())
15664 return false;
15665
15666 // We can't delay parsing the body of a function template with a deduced
15667 // return type (yet).
15668 if (D.getDeclSpec().hasAutoTypeSpec()) {
15669 // If the placeholder introduces a non-deduced trailing return type,
15670 // we can still delay parsing it.
15671 if (D.getNumTypeObjects()) {
15672 const auto &Outer = D.getTypeObject(i: D.getNumTypeObjects() - 1);
15673 if (Outer.Kind == DeclaratorChunk::Function &&
15674 Outer.Fun.hasTrailingReturnType()) {
15675 QualType Ty = GetTypeFromParser(Ty: Outer.Fun.getTrailingReturnType());
15676 return Ty.isNull() || !Ty->isUndeducedType();
15677 }
15678 }
15679 return false;
15680 }
15681
15682 return true;
15683}
15684
15685bool Sema::canSkipFunctionBody(Decl *D) {
15686 // We cannot skip the body of a function (or function template) which is
15687 // constexpr, since we may need to evaluate its body in order to parse the
15688 // rest of the file.
15689 // We cannot skip the body of a function with an undeduced return type,
15690 // because any callers of that function need to know the type.
15691 if (const FunctionDecl *FD = D->getAsFunction()) {
15692 if (FD->isConstexpr())
15693 return false;
15694 // We can't simply call Type::isUndeducedType here, because inside template
15695 // auto can be deduced to a dependent type, which is not considered
15696 // "undeduced".
15697 if (FD->getReturnType()->getContainedDeducedType())
15698 return false;
15699 }
15700 return Consumer.shouldSkipFunctionBody(D);
15701}
15702
15703Decl *Sema::ActOnSkippedFunctionBody(Decl *Decl) {
15704 if (!Decl)
15705 return nullptr;
15706 if (FunctionDecl *FD = Decl->getAsFunction())
15707 FD->setHasSkippedBody();
15708 else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(Val: Decl))
15709 MD->setHasSkippedBody();
15710 return Decl;
15711}
15712
15713Decl *Sema::ActOnFinishFunctionBody(Decl *D, Stmt *BodyArg) {
15714 return ActOnFinishFunctionBody(Decl: D, Body: BodyArg, /*IsInstantiation=*/false);
15715}
15716
15717/// RAII object that pops an ExpressionEvaluationContext when exiting a function
15718/// body.
15719class ExitFunctionBodyRAII {
15720public:
15721 ExitFunctionBodyRAII(Sema &S, bool IsLambda) : S(S), IsLambda(IsLambda) {}
15722 ~ExitFunctionBodyRAII() {
15723 if (!IsLambda)
15724 S.PopExpressionEvaluationContext();
15725 }
15726
15727private:
15728 Sema &S;
15729 bool IsLambda = false;
15730};
15731
15732static void diagnoseImplicitlyRetainedSelf(Sema &S) {
15733 llvm::DenseMap<const BlockDecl *, bool> EscapeInfo;
15734
15735 auto IsOrNestedInEscapingBlock = [&](const BlockDecl *BD) {
15736 if (EscapeInfo.count(Val: BD))
15737 return EscapeInfo[BD];
15738
15739 bool R = false;
15740 const BlockDecl *CurBD = BD;
15741
15742 do {
15743 R = !CurBD->doesNotEscape();
15744 if (R)
15745 break;
15746 CurBD = CurBD->getParent()->getInnermostBlockDecl();
15747 } while (CurBD);
15748
15749 return EscapeInfo[BD] = R;
15750 };
15751
15752 // If the location where 'self' is implicitly retained is inside a escaping
15753 // block, emit a diagnostic.
15754 for (const std::pair<SourceLocation, const BlockDecl *> &P :
15755 S.ImplicitlyRetainedSelfLocs)
15756 if (IsOrNestedInEscapingBlock(P.second))
15757 S.Diag(Loc: P.first, DiagID: diag::warn_implicitly_retains_self)
15758 << FixItHint::CreateInsertion(InsertionLoc: P.first, Code: "self->");
15759}
15760
15761static bool methodHasName(const FunctionDecl *FD, StringRef Name) {
15762 return isa<CXXMethodDecl>(Val: FD) && FD->param_empty() &&
15763 FD->getDeclName().isIdentifier() && FD->getName() == Name;
15764}
15765
15766bool Sema::CanBeGetReturnObject(const FunctionDecl *FD) {
15767 return methodHasName(FD, Name: "get_return_object");
15768}
15769
15770bool Sema::CanBeGetReturnTypeOnAllocFailure(const FunctionDecl *FD) {
15771 return FD->isStatic() &&
15772 methodHasName(FD, Name: "get_return_object_on_allocation_failure");
15773}
15774
15775void Sema::CheckCoroutineWrapper(FunctionDecl *FD) {
15776 RecordDecl *RD = FD->getReturnType()->getAsRecordDecl();
15777 if (!RD || !RD->getUnderlyingDecl()->hasAttr<CoroReturnTypeAttr>())
15778 return;
15779 // Allow some_promise_type::get_return_object().
15780 if (CanBeGetReturnObject(FD) || CanBeGetReturnTypeOnAllocFailure(FD))
15781 return;
15782 if (!FD->hasAttr<CoroWrapperAttr>())
15783 Diag(Loc: FD->getLocation(), DiagID: diag::err_coroutine_return_type) << RD;
15784}
15785
15786Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
15787 bool IsInstantiation) {
15788 FunctionScopeInfo *FSI = getCurFunction();
15789 FunctionDecl *FD = dcl ? dcl->getAsFunction() : nullptr;
15790
15791 if (FSI->UsesFPIntrin && FD && !FD->hasAttr<StrictFPAttr>())
15792 FD->addAttr(A: StrictFPAttr::CreateImplicit(Ctx&: Context));
15793
15794 sema::AnalysisBasedWarnings::Policy WP = AnalysisWarnings.getDefaultPolicy();
15795 sema::AnalysisBasedWarnings::Policy *ActivePolicy = nullptr;
15796
15797 // If we skip function body, we can't tell if a function is a coroutine.
15798 if (getLangOpts().Coroutines && FD && !FD->hasSkippedBody()) {
15799 if (FSI->isCoroutine())
15800 CheckCompletedCoroutineBody(FD, Body);
15801 else
15802 CheckCoroutineWrapper(FD);
15803 }
15804
15805 {
15806 // Do not call PopExpressionEvaluationContext() if it is a lambda because
15807 // one is already popped when finishing the lambda in BuildLambdaExpr().
15808 // This is meant to pop the context added in ActOnStartOfFunctionDef().
15809 ExitFunctionBodyRAII ExitRAII(*this, isLambdaCallOperator(DC: FD));
15810 if (FD) {
15811 // If this is called by Parser::ParseFunctionDefinition() after marking
15812 // the declaration as deleted, and if the deleted-function-body contains
15813 // a message (C++26), then a DefaultedOrDeletedInfo will have already been
15814 // added to store that message; do not overwrite it in that case.
15815 //
15816 // Since this would always set the body to 'nullptr' in that case anyway,
15817 // which is already done when the function decl is initially created,
15818 // always skipping this irrespective of whether there is a delete message
15819 // should not be a problem.
15820 if (!FD->isDeletedAsWritten())
15821 FD->setBody(Body);
15822 FD->setWillHaveBody(false);
15823 CheckImmediateEscalatingFunctionDefinition(FD, FSI);
15824
15825 if (getLangOpts().CPlusPlus14) {
15826 if (!FD->isInvalidDecl() && Body && !FD->isDependentContext() &&
15827 FD->getReturnType()->isUndeducedType()) {
15828 // For a function with a deduced result type to return void,
15829 // the result type as written must be 'auto' or 'decltype(auto)',
15830 // possibly cv-qualified or constrained, but not ref-qualified.
15831 if (!FD->getReturnType()->getAs<AutoType>()) {
15832 Diag(Loc: dcl->getLocation(), DiagID: diag::err_auto_fn_no_return_but_not_auto)
15833 << FD->getReturnType();
15834 FD->setInvalidDecl();
15835 } else {
15836 // Falling off the end of the function is the same as 'return;'.
15837 Expr *Dummy = nullptr;
15838 if (DeduceFunctionTypeFromReturnExpr(
15839 FD, ReturnLoc: dcl->getLocation(), RetExpr: Dummy,
15840 AT: FD->getReturnType()->getAs<AutoType>()))
15841 FD->setInvalidDecl();
15842 }
15843 }
15844 } else if (getLangOpts().CPlusPlus && isLambdaCallOperator(DC: FD)) {
15845 // In C++11, we don't use 'auto' deduction rules for lambda call
15846 // operators because we don't support return type deduction.
15847 auto *LSI = getCurLambda();
15848 if (LSI->HasImplicitReturnType) {
15849 deduceClosureReturnType(CSI&: *LSI);
15850
15851 // C++11 [expr.prim.lambda]p4:
15852 // [...] if there are no return statements in the compound-statement
15853 // [the deduced type is] the type void
15854 QualType RetType =
15855 LSI->ReturnType.isNull() ? Context.VoidTy : LSI->ReturnType;
15856
15857 // Update the return type to the deduced type.
15858 const auto *Proto = FD->getType()->castAs<FunctionProtoType>();
15859 FD->setType(Context.getFunctionType(ResultTy: RetType, Args: Proto->getParamTypes(),
15860 EPI: Proto->getExtProtoInfo()));
15861 }
15862 }
15863
15864 // If the function implicitly returns zero (like 'main') or is naked,
15865 // don't complain about missing return statements.
15866 if (FD->hasImplicitReturnZero() || FD->hasAttr<NakedAttr>())
15867 WP.disableCheckFallThrough();
15868
15869 // MSVC permits the use of pure specifier (=0) on function definition,
15870 // defined at class scope, warn about this non-standard construct.
15871 if (getLangOpts().MicrosoftExt && FD->isPureVirtual() &&
15872 !FD->isOutOfLine())
15873 Diag(Loc: FD->getLocation(), DiagID: diag::ext_pure_function_definition);
15874
15875 if (!FD->isInvalidDecl()) {
15876 // Don't diagnose unused parameters of defaulted, deleted or naked
15877 // functions.
15878 if (!FD->isDeleted() && !FD->isDefaulted() && !FD->hasSkippedBody() &&
15879 !FD->hasAttr<NakedAttr>())
15880 DiagnoseUnusedParameters(Parameters: FD->parameters());
15881 DiagnoseSizeOfParametersAndReturnValue(Parameters: FD->parameters(),
15882 ReturnTy: FD->getReturnType(), D: FD);
15883
15884 // If this is a structor, we need a vtable.
15885 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Val: FD))
15886 MarkVTableUsed(Loc: FD->getLocation(), Class: Constructor->getParent());
15887 else if (CXXDestructorDecl *Destructor =
15888 dyn_cast<CXXDestructorDecl>(Val: FD))
15889 MarkVTableUsed(Loc: FD->getLocation(), Class: Destructor->getParent());
15890
15891 // Try to apply the named return value optimization. We have to check
15892 // if we can do this here because lambdas keep return statements around
15893 // to deduce an implicit return type.
15894 if (FD->getReturnType()->isRecordType() &&
15895 (!getLangOpts().CPlusPlus || !FD->isDependentContext()))
15896 computeNRVO(Body, Scope: FSI);
15897 }
15898
15899 // GNU warning -Wmissing-prototypes:
15900 // Warn if a global function is defined without a previous
15901 // prototype declaration. This warning is issued even if the
15902 // definition itself provides a prototype. The aim is to detect
15903 // global functions that fail to be declared in header files.
15904 const FunctionDecl *PossiblePrototype = nullptr;
15905 if (ShouldWarnAboutMissingPrototype(FD, PossiblePrototype)) {
15906 Diag(Loc: FD->getLocation(), DiagID: diag::warn_missing_prototype) << FD;
15907
15908 if (PossiblePrototype) {
15909 // We found a declaration that is not a prototype,
15910 // but that could be a zero-parameter prototype
15911 if (TypeSourceInfo *TI = PossiblePrototype->getTypeSourceInfo()) {
15912 TypeLoc TL = TI->getTypeLoc();
15913 if (FunctionNoProtoTypeLoc FTL = TL.getAs<FunctionNoProtoTypeLoc>())
15914 Diag(Loc: PossiblePrototype->getLocation(),
15915 DiagID: diag::note_declaration_not_a_prototype)
15916 << (FD->getNumParams() != 0)
15917 << (FD->getNumParams() == 0 ? FixItHint::CreateInsertion(
15918 InsertionLoc: FTL.getRParenLoc(), Code: "void")
15919 : FixItHint{});
15920 }
15921 } else {
15922 // Returns true if the token beginning at this Loc is `const`.
15923 auto isLocAtConst = [&](SourceLocation Loc, const SourceManager &SM,
15924 const LangOptions &LangOpts) {
15925 std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(Loc);
15926 if (LocInfo.first.isInvalid())
15927 return false;
15928
15929 bool Invalid = false;
15930 StringRef Buffer = SM.getBufferData(FID: LocInfo.first, Invalid: &Invalid);
15931 if (Invalid)
15932 return false;
15933
15934 if (LocInfo.second > Buffer.size())
15935 return false;
15936
15937 const char *LexStart = Buffer.data() + LocInfo.second;
15938 StringRef StartTok(LexStart, Buffer.size() - LocInfo.second);
15939
15940 return StartTok.consume_front(Prefix: "const") &&
15941 (StartTok.empty() || isWhitespace(c: StartTok[0]) ||
15942 StartTok.starts_with(Prefix: "/*") || StartTok.starts_with(Prefix: "//"));
15943 };
15944
15945 auto findBeginLoc = [&]() {
15946 // If the return type has `const` qualifier, we want to insert
15947 // `static` before `const` (and not before the typename).
15948 if ((FD->getReturnType()->isAnyPointerType() &&
15949 FD->getReturnType()->getPointeeType().isConstQualified()) ||
15950 FD->getReturnType().isConstQualified()) {
15951 // But only do this if we can determine where the `const` is.
15952
15953 if (isLocAtConst(FD->getBeginLoc(), getSourceManager(),
15954 getLangOpts()))
15955
15956 return FD->getBeginLoc();
15957 }
15958 return FD->getTypeSpecStartLoc();
15959 };
15960 Diag(Loc: FD->getTypeSpecStartLoc(),
15961 DiagID: diag::note_static_for_internal_linkage)
15962 << /* function */ 1
15963 << (FD->getStorageClass() == SC_None
15964 ? FixItHint::CreateInsertion(InsertionLoc: findBeginLoc(), Code: "static ")
15965 : FixItHint{});
15966 }
15967 }
15968
15969 // We might not have found a prototype because we didn't wish to warn on
15970 // the lack of a missing prototype. Try again without the checks for
15971 // whether we want to warn on the missing prototype.
15972 if (!PossiblePrototype)
15973 (void)FindPossiblePrototype(FD, PossiblePrototype);
15974
15975 // If the function being defined does not have a prototype, then we may
15976 // need to diagnose it as changing behavior in C23 because we now know
15977 // whether the function accepts arguments or not. This only handles the
15978 // case where the definition has no prototype but does have parameters
15979 // and either there is no previous potential prototype, or the previous
15980 // potential prototype also has no actual prototype. This handles cases
15981 // like:
15982 // void f(); void f(a) int a; {}
15983 // void g(a) int a; {}
15984 // See MergeFunctionDecl() for other cases of the behavior change
15985 // diagnostic. See GetFullTypeForDeclarator() for handling of a function
15986 // type without a prototype.
15987 if (!FD->hasWrittenPrototype() && FD->getNumParams() != 0 &&
15988 (!PossiblePrototype || (!PossiblePrototype->hasWrittenPrototype() &&
15989 !PossiblePrototype->isImplicit()))) {
15990 // The function definition has parameters, so this will change behavior
15991 // in C23. If there is a possible prototype, it comes before the
15992 // function definition.
15993 // FIXME: The declaration may have already been diagnosed as being
15994 // deprecated in GetFullTypeForDeclarator() if it had no arguments, but
15995 // there's no way to test for the "changes behavior" condition in
15996 // SemaType.cpp when forming the declaration's function type. So, we do
15997 // this awkward dance instead.
15998 //
15999 // If we have a possible prototype and it declares a function with a
16000 // prototype, we don't want to diagnose it; if we have a possible
16001 // prototype and it has no prototype, it may have already been
16002 // diagnosed in SemaType.cpp as deprecated depending on whether
16003 // -Wstrict-prototypes is enabled. If we already warned about it being
16004 // deprecated, add a note that it also changes behavior. If we didn't
16005 // warn about it being deprecated (because the diagnostic is not
16006 // enabled), warn now that it is deprecated and changes behavior.
16007
16008 // This K&R C function definition definitely changes behavior in C23,
16009 // so diagnose it.
16010 Diag(Loc: FD->getLocation(), DiagID: diag::warn_non_prototype_changes_behavior)
16011 << /*definition*/ 1 << /* not supported in C23 */ 0;
16012
16013 // If we have a possible prototype for the function which is a user-
16014 // visible declaration, we already tested that it has no prototype.
16015 // This will change behavior in C23. This gets a warning rather than a
16016 // note because it's the same behavior-changing problem as with the
16017 // definition.
16018 if (PossiblePrototype)
16019 Diag(Loc: PossiblePrototype->getLocation(),
16020 DiagID: diag::warn_non_prototype_changes_behavior)
16021 << /*declaration*/ 0 << /* conflicting */ 1 << /*subsequent*/ 1
16022 << /*definition*/ 1;
16023 }
16024
16025 // Warn on CPUDispatch with an actual body.
16026 if (FD->isMultiVersion() && FD->hasAttr<CPUDispatchAttr>() && Body)
16027 if (const auto *CmpndBody = dyn_cast<CompoundStmt>(Val: Body))
16028 if (!CmpndBody->body_empty())
16029 Diag(Loc: CmpndBody->body_front()->getBeginLoc(),
16030 DiagID: diag::warn_dispatch_body_ignored);
16031
16032 if (auto *MD = dyn_cast<CXXMethodDecl>(Val: FD)) {
16033 const CXXMethodDecl *KeyFunction;
16034 if (MD->isOutOfLine() && (MD = MD->getCanonicalDecl()) &&
16035 MD->isVirtual() &&
16036 (KeyFunction = Context.getCurrentKeyFunction(RD: MD->getParent())) &&
16037 MD == KeyFunction->getCanonicalDecl()) {
16038 // Update the key-function state if necessary for this ABI.
16039 if (FD->isInlined() &&
16040 !Context.getTargetInfo().getCXXABI().canKeyFunctionBeInline()) {
16041 Context.setNonKeyFunction(MD);
16042
16043 // If the newly-chosen key function is already defined, then we
16044 // need to mark the vtable as used retroactively.
16045 KeyFunction = Context.getCurrentKeyFunction(RD: MD->getParent());
16046 const FunctionDecl *Definition;
16047 if (KeyFunction && KeyFunction->isDefined(Definition))
16048 MarkVTableUsed(Loc: Definition->getLocation(), Class: MD->getParent(), DefinitionRequired: true);
16049 } else {
16050 // We just defined they key function; mark the vtable as used.
16051 MarkVTableUsed(Loc: FD->getLocation(), Class: MD->getParent(), DefinitionRequired: true);
16052 }
16053 }
16054 }
16055
16056 assert((FD == getCurFunctionDecl(/*AllowLambdas=*/true)) &&
16057 "Function parsing confused");
16058 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(Val: dcl)) {
16059 assert(MD == getCurMethodDecl() && "Method parsing confused");
16060 MD->setBody(Body);
16061 if (!MD->isInvalidDecl()) {
16062 DiagnoseSizeOfParametersAndReturnValue(Parameters: MD->parameters(),
16063 ReturnTy: MD->getReturnType(), D: MD);
16064
16065 if (Body)
16066 computeNRVO(Body, Scope: FSI);
16067 }
16068 if (FSI->ObjCShouldCallSuper) {
16069 Diag(Loc: MD->getEndLoc(), DiagID: diag::warn_objc_missing_super_call)
16070 << MD->getSelector().getAsString();
16071 FSI->ObjCShouldCallSuper = false;
16072 }
16073 if (FSI->ObjCWarnForNoDesignatedInitChain) {
16074 const ObjCMethodDecl *InitMethod = nullptr;
16075 bool isDesignated =
16076 MD->isDesignatedInitializerForTheInterface(InitMethod: &InitMethod);
16077 assert(isDesignated && InitMethod);
16078 (void)isDesignated;
16079
16080 auto superIsNSObject = [&](const ObjCMethodDecl *MD) {
16081 auto IFace = MD->getClassInterface();
16082 if (!IFace)
16083 return false;
16084 auto SuperD = IFace->getSuperClass();
16085 if (!SuperD)
16086 return false;
16087 return SuperD->getIdentifier() ==
16088 ObjC().NSAPIObj->getNSClassId(K: NSAPI::ClassId_NSObject);
16089 };
16090 // Don't issue this warning for unavailable inits or direct subclasses
16091 // of NSObject.
16092 if (!MD->isUnavailable() && !superIsNSObject(MD)) {
16093 Diag(Loc: MD->getLocation(),
16094 DiagID: diag::warn_objc_designated_init_missing_super_call);
16095 Diag(Loc: InitMethod->getLocation(),
16096 DiagID: diag::note_objc_designated_init_marked_here);
16097 }
16098 FSI->ObjCWarnForNoDesignatedInitChain = false;
16099 }
16100 if (FSI->ObjCWarnForNoInitDelegation) {
16101 // Don't issue this warning for unavailable inits.
16102 if (!MD->isUnavailable())
16103 Diag(Loc: MD->getLocation(),
16104 DiagID: diag::warn_objc_secondary_init_missing_init_call);
16105 FSI->ObjCWarnForNoInitDelegation = false;
16106 }
16107
16108 diagnoseImplicitlyRetainedSelf(S&: *this);
16109 } else {
16110 // Parsing the function declaration failed in some way. Pop the fake scope
16111 // we pushed on.
16112 PopFunctionScopeInfo(WP: ActivePolicy, D: dcl);
16113 return nullptr;
16114 }
16115
16116 if (Body && FSI->HasPotentialAvailabilityViolations)
16117 DiagnoseUnguardedAvailabilityViolations(FD: dcl);
16118
16119 assert(!FSI->ObjCShouldCallSuper &&
16120 "This should only be set for ObjC methods, which should have been "
16121 "handled in the block above.");
16122
16123 // Verify and clean out per-function state.
16124 if (Body && (!FD || !FD->isDefaulted())) {
16125 // C++ constructors that have function-try-blocks can't have return
16126 // statements in the handlers of that block. (C++ [except.handle]p14)
16127 // Verify this.
16128 if (FD && isa<CXXConstructorDecl>(Val: FD) && isa<CXXTryStmt>(Val: Body))
16129 DiagnoseReturnInConstructorExceptionHandler(TryBlock: cast<CXXTryStmt>(Val: Body));
16130
16131 // Verify that gotos and switch cases don't jump into scopes illegally.
16132 if (FSI->NeedsScopeChecking() && !PP.isCodeCompletionEnabled())
16133 DiagnoseInvalidJumps(Body);
16134
16135 if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(Val: dcl)) {
16136 if (!Destructor->getParent()->isDependentType())
16137 CheckDestructor(Destructor);
16138
16139 MarkBaseAndMemberDestructorsReferenced(Loc: Destructor->getLocation(),
16140 Record: Destructor->getParent());
16141 }
16142
16143 // If any errors have occurred, clear out any temporaries that may have
16144 // been leftover. This ensures that these temporaries won't be picked up
16145 // for deletion in some later function.
16146 if (hasUncompilableErrorOccurred() ||
16147 hasAnyUnrecoverableErrorsInThisFunction() ||
16148 getDiagnostics().getSuppressAllDiagnostics()) {
16149 DiscardCleanupsInEvaluationContext();
16150 }
16151 if (!hasUncompilableErrorOccurred() && !isa<FunctionTemplateDecl>(Val: dcl)) {
16152 // Since the body is valid, issue any analysis-based warnings that are
16153 // enabled.
16154 ActivePolicy = &WP;
16155 }
16156
16157 if (!IsInstantiation && FD &&
16158 (FD->isConstexpr() || FD->hasAttr<MSConstexprAttr>()) &&
16159 !FD->isInvalidDecl() &&
16160 !CheckConstexprFunctionDefinition(FD, Kind: CheckConstexprKind::Diagnose))
16161 FD->setInvalidDecl();
16162
16163 if (FD && FD->hasAttr<NakedAttr>()) {
16164 for (const Stmt *S : Body->children()) {
16165 // Allow local register variables without initializer as they don't
16166 // require prologue.
16167 bool RegisterVariables = false;
16168 if (auto *DS = dyn_cast<DeclStmt>(Val: S)) {
16169 for (const auto *Decl : DS->decls()) {
16170 if (const auto *Var = dyn_cast<VarDecl>(Val: Decl)) {
16171 RegisterVariables =
16172 Var->hasAttr<AsmLabelAttr>() && !Var->hasInit();
16173 if (!RegisterVariables)
16174 break;
16175 }
16176 }
16177 }
16178 if (RegisterVariables)
16179 continue;
16180 if (!isa<AsmStmt>(Val: S) && !isa<NullStmt>(Val: S)) {
16181 Diag(Loc: S->getBeginLoc(), DiagID: diag::err_non_asm_stmt_in_naked_function);
16182 Diag(Loc: FD->getAttr<NakedAttr>()->getLocation(), DiagID: diag::note_attribute);
16183 FD->setInvalidDecl();
16184 break;
16185 }
16186 }
16187 }
16188
16189 assert(ExprCleanupObjects.size() ==
16190 ExprEvalContexts.back().NumCleanupObjects &&
16191 "Leftover temporaries in function");
16192 assert(!Cleanup.exprNeedsCleanups() &&
16193 "Unaccounted cleanups in function");
16194 assert(MaybeODRUseExprs.empty() &&
16195 "Leftover expressions for odr-use checking");
16196 }
16197 } // Pops the ExitFunctionBodyRAII scope, which needs to happen before we pop
16198 // the declaration context below. Otherwise, we're unable to transform
16199 // 'this' expressions when transforming immediate context functions.
16200
16201 if (!IsInstantiation)
16202 PopDeclContext();
16203
16204 PopFunctionScopeInfo(WP: ActivePolicy, D: dcl);
16205 // If any errors have occurred, clear out any temporaries that may have
16206 // been leftover. This ensures that these temporaries won't be picked up for
16207 // deletion in some later function.
16208 if (hasUncompilableErrorOccurred()) {
16209 DiscardCleanupsInEvaluationContext();
16210 }
16211
16212 if (FD && ((LangOpts.OpenMP && (LangOpts.OpenMPIsTargetDevice ||
16213 !LangOpts.OMPTargetTriples.empty())) ||
16214 LangOpts.CUDA || LangOpts.SYCLIsDevice)) {
16215 auto ES = getEmissionStatus(Decl: FD);
16216 if (ES == Sema::FunctionEmissionStatus::Emitted ||
16217 ES == Sema::FunctionEmissionStatus::Unknown)
16218 DeclsToCheckForDeferredDiags.insert(X: FD);
16219 }
16220
16221 if (FD && !FD->isDeleted())
16222 checkTypeSupport(Ty: FD->getType(), Loc: FD->getLocation(), D: FD);
16223
16224 return dcl;
16225}
16226
16227/// When we finish delayed parsing of an attribute, we must attach it to the
16228/// relevant Decl.
16229void Sema::ActOnFinishDelayedAttribute(Scope *S, Decl *D,
16230 ParsedAttributes &Attrs) {
16231 // Always attach attributes to the underlying decl.
16232 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(Val: D))
16233 D = TD->getTemplatedDecl();
16234 ProcessDeclAttributeList(S, D, AttrList: Attrs);
16235 ProcessAPINotes(D);
16236
16237 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(Val: D))
16238 if (Method->isStatic())
16239 checkThisInStaticMemberFunctionAttributes(Method);
16240}
16241
16242NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc,
16243 IdentifierInfo &II, Scope *S) {
16244 // It is not valid to implicitly define a function in C23.
16245 assert(LangOpts.implicitFunctionsAllowed() &&
16246 "Implicit function declarations aren't allowed in this language mode");
16247
16248 // Find the scope in which the identifier is injected and the corresponding
16249 // DeclContext.
16250 // FIXME: C89 does not say what happens if there is no enclosing block scope.
16251 // In that case, we inject the declaration into the translation unit scope
16252 // instead.
16253 Scope *BlockScope = S;
16254 while (!BlockScope->isCompoundStmtScope() && BlockScope->getParent())
16255 BlockScope = BlockScope->getParent();
16256
16257 // Loop until we find a DeclContext that is either a function/method or the
16258 // translation unit, which are the only two valid places to implicitly define
16259 // a function. This avoids accidentally defining the function within a tag
16260 // declaration, for example.
16261 Scope *ContextScope = BlockScope;
16262 while (!ContextScope->getEntity() ||
16263 (!ContextScope->getEntity()->isFunctionOrMethod() &&
16264 !ContextScope->getEntity()->isTranslationUnit()))
16265 ContextScope = ContextScope->getParent();
16266 ContextRAII SavedContext(*this, ContextScope->getEntity());
16267
16268 // Before we produce a declaration for an implicitly defined
16269 // function, see whether there was a locally-scoped declaration of
16270 // this name as a function or variable. If so, use that
16271 // (non-visible) declaration, and complain about it.
16272 NamedDecl *ExternCPrev = findLocallyScopedExternCDecl(Name: &II);
16273 if (ExternCPrev) {
16274 // We still need to inject the function into the enclosing block scope so
16275 // that later (non-call) uses can see it.
16276 PushOnScopeChains(D: ExternCPrev, S: BlockScope, /*AddToContext*/false);
16277
16278 // C89 footnote 38:
16279 // If in fact it is not defined as having type "function returning int",
16280 // the behavior is undefined.
16281 if (!isa<FunctionDecl>(Val: ExternCPrev) ||
16282 !Context.typesAreCompatible(
16283 T1: cast<FunctionDecl>(Val: ExternCPrev)->getType(),
16284 T2: Context.getFunctionNoProtoType(ResultTy: Context.IntTy))) {
16285 Diag(Loc, DiagID: diag::ext_use_out_of_scope_declaration)
16286 << ExternCPrev << !getLangOpts().C99;
16287 Diag(Loc: ExternCPrev->getLocation(), DiagID: diag::note_previous_declaration);
16288 return ExternCPrev;
16289 }
16290 }
16291
16292 // Extension in C99 (defaults to error). Legal in C89, but warn about it.
16293 unsigned diag_id;
16294 if (II.getName().starts_with(Prefix: "__builtin_"))
16295 diag_id = diag::warn_builtin_unknown;
16296 // OpenCL v2.0 s6.9.u - Implicit function declaration is not supported.
16297 else if (getLangOpts().C99)
16298 diag_id = diag::ext_implicit_function_decl_c99;
16299 else
16300 diag_id = diag::warn_implicit_function_decl;
16301
16302 TypoCorrection Corrected;
16303 // Because typo correction is expensive, only do it if the implicit
16304 // function declaration is going to be treated as an error.
16305 //
16306 // Perform the correction before issuing the main diagnostic, as some
16307 // consumers use typo-correction callbacks to enhance the main diagnostic.
16308 if (S && !ExternCPrev &&
16309 (Diags.getDiagnosticLevel(DiagID: diag_id, Loc) >= DiagnosticsEngine::Error)) {
16310 DeclFilterCCC<FunctionDecl> CCC{};
16311 Corrected = CorrectTypo(Typo: DeclarationNameInfo(&II, Loc), LookupKind: LookupOrdinaryName,
16312 S, SS: nullptr, CCC, Mode: CTK_NonError);
16313 }
16314
16315 Diag(Loc, DiagID: diag_id) << &II;
16316 if (Corrected) {
16317 // If the correction is going to suggest an implicitly defined function,
16318 // skip the correction as not being a particularly good idea.
16319 bool Diagnose = true;
16320 if (const auto *D = Corrected.getCorrectionDecl())
16321 Diagnose = !D->isImplicit();
16322 if (Diagnose)
16323 diagnoseTypo(Correction: Corrected, TypoDiag: PDiag(DiagID: diag::note_function_suggestion),
16324 /*ErrorRecovery*/ false);
16325 }
16326
16327 // If we found a prior declaration of this function, don't bother building
16328 // another one. We've already pushed that one into scope, so there's nothing
16329 // more to do.
16330 if (ExternCPrev)
16331 return ExternCPrev;
16332
16333 // Set a Declarator for the implicit definition: int foo();
16334 const char *Dummy;
16335 AttributeFactory attrFactory;
16336 DeclSpec DS(attrFactory);
16337 unsigned DiagID;
16338 bool Error = DS.SetTypeSpecType(T: DeclSpec::TST_int, Loc, PrevSpec&: Dummy, DiagID,
16339 Policy: Context.getPrintingPolicy());
16340 (void)Error; // Silence warning.
16341 assert(!Error && "Error setting up implicit decl!");
16342 SourceLocation NoLoc;
16343 Declarator D(DS, ParsedAttributesView::none(), DeclaratorContext::Block);
16344 D.AddTypeInfo(TI: DeclaratorChunk::getFunction(/*HasProto=*/false,
16345 /*IsAmbiguous=*/false,
16346 /*LParenLoc=*/NoLoc,
16347 /*Params=*/nullptr,
16348 /*NumParams=*/0,
16349 /*EllipsisLoc=*/NoLoc,
16350 /*RParenLoc=*/NoLoc,
16351 /*RefQualifierIsLvalueRef=*/true,
16352 /*RefQualifierLoc=*/NoLoc,
16353 /*MutableLoc=*/NoLoc, ESpecType: EST_None,
16354 /*ESpecRange=*/SourceRange(),
16355 /*Exceptions=*/nullptr,
16356 /*ExceptionRanges=*/nullptr,
16357 /*NumExceptions=*/0,
16358 /*NoexceptExpr=*/nullptr,
16359 /*ExceptionSpecTokens=*/nullptr,
16360 /*DeclsInPrototype=*/std::nullopt,
16361 LocalRangeBegin: Loc, LocalRangeEnd: Loc, TheDeclarator&: D),
16362 attrs: std::move(DS.getAttributes()), EndLoc: SourceLocation());
16363 D.SetIdentifier(Id: &II, IdLoc: Loc);
16364
16365 // Insert this function into the enclosing block scope.
16366 FunctionDecl *FD = cast<FunctionDecl>(Val: ActOnDeclarator(S: BlockScope, D));
16367 FD->setImplicit();
16368
16369 AddKnownFunctionAttributes(FD);
16370
16371 return FD;
16372}
16373
16374void Sema::AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction(
16375 FunctionDecl *FD) {
16376 if (FD->isInvalidDecl())
16377 return;
16378
16379 if (FD->getDeclName().getCXXOverloadedOperator() != OO_New &&
16380 FD->getDeclName().getCXXOverloadedOperator() != OO_Array_New)
16381 return;
16382
16383 std::optional<unsigned> AlignmentParam;
16384 bool IsNothrow = false;
16385 if (!FD->isReplaceableGlobalAllocationFunction(AlignmentParam: &AlignmentParam, IsNothrow: &IsNothrow))
16386 return;
16387
16388 // C++2a [basic.stc.dynamic.allocation]p4:
16389 // An allocation function that has a non-throwing exception specification
16390 // indicates failure by returning a null pointer value. Any other allocation
16391 // function never returns a null pointer value and indicates failure only by
16392 // throwing an exception [...]
16393 //
16394 // However, -fcheck-new invalidates this possible assumption, so don't add
16395 // NonNull when that is enabled.
16396 if (!IsNothrow && !FD->hasAttr<ReturnsNonNullAttr>() &&
16397 !getLangOpts().CheckNew)
16398 FD->addAttr(A: ReturnsNonNullAttr::CreateImplicit(Ctx&: Context, Range: FD->getLocation()));
16399
16400 // C++2a [basic.stc.dynamic.allocation]p2:
16401 // An allocation function attempts to allocate the requested amount of
16402 // storage. [...] If the request succeeds, the value returned by a
16403 // replaceable allocation function is a [...] pointer value p0 different
16404 // from any previously returned value p1 [...]
16405 //
16406 // However, this particular information is being added in codegen,
16407 // because there is an opt-out switch for it (-fno-assume-sane-operator-new)
16408
16409 // C++2a [basic.stc.dynamic.allocation]p2:
16410 // An allocation function attempts to allocate the requested amount of
16411 // storage. If it is successful, it returns the address of the start of a
16412 // block of storage whose length in bytes is at least as large as the
16413 // requested size.
16414 if (!FD->hasAttr<AllocSizeAttr>()) {
16415 FD->addAttr(A: AllocSizeAttr::CreateImplicit(
16416 Ctx&: Context, /*ElemSizeParam=*/ParamIdx(1, FD),
16417 /*NumElemsParam=*/ParamIdx(), Range: FD->getLocation()));
16418 }
16419
16420 // C++2a [basic.stc.dynamic.allocation]p3:
16421 // For an allocation function [...], the pointer returned on a successful
16422 // call shall represent the address of storage that is aligned as follows:
16423 // (3.1) If the allocation function takes an argument of type
16424 // std​::​align_­val_­t, the storage will have the alignment
16425 // specified by the value of this argument.
16426 if (AlignmentParam && !FD->hasAttr<AllocAlignAttr>()) {
16427 FD->addAttr(A: AllocAlignAttr::CreateImplicit(
16428 Ctx&: Context, ParamIndex: ParamIdx(*AlignmentParam, FD), Range: FD->getLocation()));
16429 }
16430
16431 // FIXME:
16432 // C++2a [basic.stc.dynamic.allocation]p3:
16433 // For an allocation function [...], the pointer returned on a successful
16434 // call shall represent the address of storage that is aligned as follows:
16435 // (3.2) Otherwise, if the allocation function is named operator new[],
16436 // the storage is aligned for any object that does not have
16437 // new-extended alignment ([basic.align]) and is no larger than the
16438 // requested size.
16439 // (3.3) Otherwise, the storage is aligned for any object that does not
16440 // have new-extended alignment and is of the requested size.
16441}
16442
16443void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) {
16444 if (FD->isInvalidDecl())
16445 return;
16446
16447 // If this is a built-in function, map its builtin attributes to
16448 // actual attributes.
16449 if (unsigned BuiltinID = FD->getBuiltinID()) {
16450 // Handle printf-formatting attributes.
16451 unsigned FormatIdx;
16452 bool HasVAListArg;
16453 if (Context.BuiltinInfo.isPrintfLike(ID: BuiltinID, FormatIdx, HasVAListArg)) {
16454 if (!FD->hasAttr<FormatAttr>()) {
16455 const char *fmt = "printf";
16456 unsigned int NumParams = FD->getNumParams();
16457 if (FormatIdx < NumParams && // NumParams may be 0 (e.g. vfprintf)
16458 FD->getParamDecl(i: FormatIdx)->getType()->isObjCObjectPointerType())
16459 fmt = "NSString";
16460 FD->addAttr(A: FormatAttr::CreateImplicit(Ctx&: Context,
16461 Type: &Context.Idents.get(Name: fmt),
16462 FormatIdx: FormatIdx+1,
16463 FirstArg: HasVAListArg ? 0 : FormatIdx+2,
16464 Range: FD->getLocation()));
16465 }
16466 }
16467 if (Context.BuiltinInfo.isScanfLike(ID: BuiltinID, FormatIdx,
16468 HasVAListArg)) {
16469 if (!FD->hasAttr<FormatAttr>())
16470 FD->addAttr(A: FormatAttr::CreateImplicit(Ctx&: Context,
16471 Type: &Context.Idents.get(Name: "scanf"),
16472 FormatIdx: FormatIdx+1,
16473 FirstArg: HasVAListArg ? 0 : FormatIdx+2,
16474 Range: FD->getLocation()));
16475 }
16476
16477 // Handle automatically recognized callbacks.
16478 SmallVector<int, 4> Encoding;
16479 if (!FD->hasAttr<CallbackAttr>() &&
16480 Context.BuiltinInfo.performsCallback(ID: BuiltinID, Encoding))
16481 FD->addAttr(A: CallbackAttr::CreateImplicit(
16482 Ctx&: Context, Encoding: Encoding.data(), EncodingSize: Encoding.size(), Range: FD->getLocation()));
16483
16484 // Mark const if we don't care about errno and/or floating point exceptions
16485 // that are the only thing preventing the function from being const. This
16486 // allows IRgen to use LLVM intrinsics for such functions.
16487 bool NoExceptions =
16488 getLangOpts().getDefaultExceptionMode() == LangOptions::FPE_Ignore;
16489 bool ConstWithoutErrnoAndExceptions =
16490 Context.BuiltinInfo.isConstWithoutErrnoAndExceptions(ID: BuiltinID);
16491 bool ConstWithoutExceptions =
16492 Context.BuiltinInfo.isConstWithoutExceptions(ID: BuiltinID);
16493 if (!FD->hasAttr<ConstAttr>() &&
16494 (ConstWithoutErrnoAndExceptions || ConstWithoutExceptions) &&
16495 (!ConstWithoutErrnoAndExceptions ||
16496 (!getLangOpts().MathErrno && NoExceptions)) &&
16497 (!ConstWithoutExceptions || NoExceptions))
16498 FD->addAttr(A: ConstAttr::CreateImplicit(Ctx&: Context, Range: FD->getLocation()));
16499
16500 // We make "fma" on GNU or Windows const because we know it does not set
16501 // errno in those environments even though it could set errno based on the
16502 // C standard.
16503 const llvm::Triple &Trip = Context.getTargetInfo().getTriple();
16504 if ((Trip.isGNUEnvironment() || Trip.isOSMSVCRT()) &&
16505 !FD->hasAttr<ConstAttr>()) {
16506 switch (BuiltinID) {
16507 case Builtin::BI__builtin_fma:
16508 case Builtin::BI__builtin_fmaf:
16509 case Builtin::BI__builtin_fmal:
16510 case Builtin::BIfma:
16511 case Builtin::BIfmaf:
16512 case Builtin::BIfmal:
16513 FD->addAttr(A: ConstAttr::CreateImplicit(Ctx&: Context, Range: FD->getLocation()));
16514 break;
16515 default:
16516 break;
16517 }
16518 }
16519
16520 if (Context.BuiltinInfo.isReturnsTwice(ID: BuiltinID) &&
16521 !FD->hasAttr<ReturnsTwiceAttr>())
16522 FD->addAttr(A: ReturnsTwiceAttr::CreateImplicit(Ctx&: Context,
16523 Range: FD->getLocation()));
16524 if (Context.BuiltinInfo.isNoThrow(ID: BuiltinID) && !FD->hasAttr<NoThrowAttr>())
16525 FD->addAttr(A: NoThrowAttr::CreateImplicit(Ctx&: Context, Range: FD->getLocation()));
16526 if (Context.BuiltinInfo.isPure(ID: BuiltinID) && !FD->hasAttr<PureAttr>())
16527 FD->addAttr(A: PureAttr::CreateImplicit(Ctx&: Context, Range: FD->getLocation()));
16528 if (Context.BuiltinInfo.isConst(ID: BuiltinID) && !FD->hasAttr<ConstAttr>())
16529 FD->addAttr(A: ConstAttr::CreateImplicit(Ctx&: Context, Range: FD->getLocation()));
16530 if (getLangOpts().CUDA && Context.BuiltinInfo.isTSBuiltin(ID: BuiltinID) &&
16531 !FD->hasAttr<CUDADeviceAttr>() && !FD->hasAttr<CUDAHostAttr>()) {
16532 // Add the appropriate attribute, depending on the CUDA compilation mode
16533 // and which target the builtin belongs to. For example, during host
16534 // compilation, aux builtins are __device__, while the rest are __host__.
16535 if (getLangOpts().CUDAIsDevice !=
16536 Context.BuiltinInfo.isAuxBuiltinID(ID: BuiltinID))
16537 FD->addAttr(A: CUDADeviceAttr::CreateImplicit(Ctx&: Context, Range: FD->getLocation()));
16538 else
16539 FD->addAttr(A: CUDAHostAttr::CreateImplicit(Ctx&: Context, Range: FD->getLocation()));
16540 }
16541
16542 // Add known guaranteed alignment for allocation functions.
16543 switch (BuiltinID) {
16544 case Builtin::BImemalign:
16545 case Builtin::BIaligned_alloc:
16546 if (!FD->hasAttr<AllocAlignAttr>())
16547 FD->addAttr(A: AllocAlignAttr::CreateImplicit(Ctx&: Context, ParamIndex: ParamIdx(1, FD),
16548 Range: FD->getLocation()));
16549 break;
16550 default:
16551 break;
16552 }
16553
16554 // Add allocsize attribute for allocation functions.
16555 switch (BuiltinID) {
16556 case Builtin::BIcalloc:
16557 FD->addAttr(A: AllocSizeAttr::CreateImplicit(
16558 Ctx&: Context, ElemSizeParam: ParamIdx(1, FD), NumElemsParam: ParamIdx(2, FD), Range: FD->getLocation()));
16559 break;
16560 case Builtin::BImemalign:
16561 case Builtin::BIaligned_alloc:
16562 case Builtin::BIrealloc:
16563 FD->addAttr(A: AllocSizeAttr::CreateImplicit(Ctx&: Context, ElemSizeParam: ParamIdx(2, FD),
16564 NumElemsParam: ParamIdx(), Range: FD->getLocation()));
16565 break;
16566 case Builtin::BImalloc:
16567 FD->addAttr(A: AllocSizeAttr::CreateImplicit(Ctx&: Context, ElemSizeParam: ParamIdx(1, FD),
16568 NumElemsParam: ParamIdx(), Range: FD->getLocation()));
16569 break;
16570 default:
16571 break;
16572 }
16573
16574 // Add lifetime attribute to std::move, std::fowrard et al.
16575 switch (BuiltinID) {
16576 case Builtin::BIaddressof:
16577 case Builtin::BI__addressof:
16578 case Builtin::BI__builtin_addressof:
16579 case Builtin::BIas_const:
16580 case Builtin::BIforward:
16581 case Builtin::BIforward_like:
16582 case Builtin::BImove:
16583 case Builtin::BImove_if_noexcept:
16584 if (ParmVarDecl *P = FD->getParamDecl(i: 0u);
16585 !P->hasAttr<LifetimeBoundAttr>())
16586 P->addAttr(
16587 A: LifetimeBoundAttr::CreateImplicit(Ctx&: Context, Range: FD->getLocation()));
16588 break;
16589 default:
16590 break;
16591 }
16592 }
16593
16594 AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction(FD);
16595
16596 // If C++ exceptions are enabled but we are told extern "C" functions cannot
16597 // throw, add an implicit nothrow attribute to any extern "C" function we come
16598 // across.
16599 if (getLangOpts().CXXExceptions && getLangOpts().ExternCNoUnwind &&
16600 FD->isExternC() && !FD->hasAttr<NoThrowAttr>()) {
16601 const auto *FPT = FD->getType()->getAs<FunctionProtoType>();
16602 if (!FPT || FPT->getExceptionSpecType() == EST_None)
16603 FD->addAttr(A: NoThrowAttr::CreateImplicit(Ctx&: Context, Range: FD->getLocation()));
16604 }
16605
16606 IdentifierInfo *Name = FD->getIdentifier();
16607 if (!Name)
16608 return;
16609 if ((!getLangOpts().CPlusPlus && FD->getDeclContext()->isTranslationUnit()) ||
16610 (isa<LinkageSpecDecl>(Val: FD->getDeclContext()) &&
16611 cast<LinkageSpecDecl>(Val: FD->getDeclContext())->getLanguage() ==
16612 LinkageSpecLanguageIDs::C)) {
16613 // Okay: this could be a libc/libm/Objective-C function we know
16614 // about.
16615 } else
16616 return;
16617
16618 if (Name->isStr(Str: "asprintf") || Name->isStr(Str: "vasprintf")) {
16619 // FIXME: asprintf and vasprintf aren't C99 functions. Should they be
16620 // target-specific builtins, perhaps?
16621 if (!FD->hasAttr<FormatAttr>())
16622 FD->addAttr(A: FormatAttr::CreateImplicit(Ctx&: Context,
16623 Type: &Context.Idents.get(Name: "printf"), FormatIdx: 2,
16624 FirstArg: Name->isStr(Str: "vasprintf") ? 0 : 3,
16625 Range: FD->getLocation()));
16626 }
16627
16628 if (Name->isStr(Str: "__CFStringMakeConstantString")) {
16629 // We already have a __builtin___CFStringMakeConstantString,
16630 // but builds that use -fno-constant-cfstrings don't go through that.
16631 if (!FD->hasAttr<FormatArgAttr>())
16632 FD->addAttr(A: FormatArgAttr::CreateImplicit(Ctx&: Context, FormatIdx: ParamIdx(1, FD),
16633 Range: FD->getLocation()));
16634 }
16635}
16636
16637TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T,
16638 TypeSourceInfo *TInfo) {
16639 assert(D.getIdentifier() && "Wrong callback for declspec without declarator");
16640 assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
16641
16642 if (!TInfo) {
16643 assert(D.isInvalidType() && "no declarator info for valid type");
16644 TInfo = Context.getTrivialTypeSourceInfo(T);
16645 }
16646
16647 // Scope manipulation handled by caller.
16648 TypedefDecl *NewTD =
16649 TypedefDecl::Create(C&: Context, DC: CurContext, StartLoc: D.getBeginLoc(),
16650 IdLoc: D.getIdentifierLoc(), Id: D.getIdentifier(), TInfo);
16651
16652 // Bail out immediately if we have an invalid declaration.
16653 if (D.isInvalidType()) {
16654 NewTD->setInvalidDecl();
16655 return NewTD;
16656 }
16657
16658 if (D.getDeclSpec().isModulePrivateSpecified()) {
16659 if (CurContext->isFunctionOrMethod())
16660 Diag(Loc: NewTD->getLocation(), DiagID: diag::err_module_private_local)
16661 << 2 << NewTD
16662 << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
16663 << FixItHint::CreateRemoval(
16664 RemoveRange: D.getDeclSpec().getModulePrivateSpecLoc());
16665 else
16666 NewTD->setModulePrivate();
16667 }
16668
16669 // C++ [dcl.typedef]p8:
16670 // If the typedef declaration defines an unnamed class (or
16671 // enum), the first typedef-name declared by the declaration
16672 // to be that class type (or enum type) is used to denote the
16673 // class type (or enum type) for linkage purposes only.
16674 // We need to check whether the type was declared in the declaration.
16675 switch (D.getDeclSpec().getTypeSpecType()) {
16676 case TST_enum:
16677 case TST_struct:
16678 case TST_interface:
16679 case TST_union:
16680 case TST_class: {
16681 TagDecl *tagFromDeclSpec = cast<TagDecl>(Val: D.getDeclSpec().getRepAsDecl());
16682 setTagNameForLinkagePurposes(TagFromDeclSpec: tagFromDeclSpec, NewTD);
16683 break;
16684 }
16685
16686 default:
16687 break;
16688 }
16689
16690 return NewTD;
16691}
16692
16693bool Sema::CheckEnumUnderlyingType(TypeSourceInfo *TI) {
16694 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
16695 QualType T = TI->getType();
16696
16697 if (T->isDependentType())
16698 return false;
16699
16700 // This doesn't use 'isIntegralType' despite the error message mentioning
16701 // integral type because isIntegralType would also allow enum types in C.
16702 if (const BuiltinType *BT = T->getAs<BuiltinType>())
16703 if (BT->isInteger())
16704 return false;
16705
16706 return Diag(Loc: UnderlyingLoc, DiagID: diag::err_enum_invalid_underlying)
16707 << T << T->isBitIntType();
16708}
16709
16710bool Sema::CheckEnumRedeclaration(SourceLocation EnumLoc, bool IsScoped,
16711 QualType EnumUnderlyingTy, bool IsFixed,
16712 const EnumDecl *Prev) {
16713 if (IsScoped != Prev->isScoped()) {
16714 Diag(Loc: EnumLoc, DiagID: diag::err_enum_redeclare_scoped_mismatch)
16715 << Prev->isScoped();
16716 Diag(Loc: Prev->getLocation(), DiagID: diag::note_previous_declaration);
16717 return true;
16718 }
16719
16720 if (IsFixed && Prev->isFixed()) {
16721 if (!EnumUnderlyingTy->isDependentType() &&
16722 !Prev->getIntegerType()->isDependentType() &&
16723 !Context.hasSameUnqualifiedType(T1: EnumUnderlyingTy,
16724 T2: Prev->getIntegerType())) {
16725 // TODO: Highlight the underlying type of the redeclaration.
16726 Diag(Loc: EnumLoc, DiagID: diag::err_enum_redeclare_type_mismatch)
16727 << EnumUnderlyingTy << Prev->getIntegerType();
16728 Diag(Loc: Prev->getLocation(), DiagID: diag::note_previous_declaration)
16729 << Prev->getIntegerTypeRange();
16730 return true;
16731 }
16732 } else if (IsFixed != Prev->isFixed()) {
16733 Diag(Loc: EnumLoc, DiagID: diag::err_enum_redeclare_fixed_mismatch)
16734 << Prev->isFixed();
16735 Diag(Loc: Prev->getLocation(), DiagID: diag::note_previous_declaration);
16736 return true;
16737 }
16738
16739 return false;
16740}
16741
16742/// Get diagnostic %select index for tag kind for
16743/// redeclaration diagnostic message.
16744/// WARNING: Indexes apply to particular diagnostics only!
16745///
16746/// \returns diagnostic %select index.
16747static unsigned getRedeclDiagFromTagKind(TagTypeKind Tag) {
16748 switch (Tag) {
16749 case TagTypeKind::Struct:
16750 return 0;
16751 case TagTypeKind::Interface:
16752 return 1;
16753 case TagTypeKind::Class:
16754 return 2;
16755 default: llvm_unreachable("Invalid tag kind for redecl diagnostic!");
16756 }
16757}
16758
16759/// Determine if tag kind is a class-key compatible with
16760/// class for redeclaration (class, struct, or __interface).
16761///
16762/// \returns true iff the tag kind is compatible.
16763static bool isClassCompatTagKind(TagTypeKind Tag)
16764{
16765 return Tag == TagTypeKind::Struct || Tag == TagTypeKind::Class ||
16766 Tag == TagTypeKind::Interface;
16767}
16768
16769Sema::NonTagKind Sema::getNonTagTypeDeclKind(const Decl *PrevDecl,
16770 TagTypeKind TTK) {
16771 if (isa<TypedefDecl>(Val: PrevDecl))
16772 return NTK_Typedef;
16773 else if (isa<TypeAliasDecl>(Val: PrevDecl))
16774 return NTK_TypeAlias;
16775 else if (isa<ClassTemplateDecl>(Val: PrevDecl))
16776 return NTK_Template;
16777 else if (isa<TypeAliasTemplateDecl>(Val: PrevDecl))
16778 return NTK_TypeAliasTemplate;
16779 else if (isa<TemplateTemplateParmDecl>(Val: PrevDecl))
16780 return NTK_TemplateTemplateArgument;
16781 switch (TTK) {
16782 case TagTypeKind::Struct:
16783 case TagTypeKind::Interface:
16784 case TagTypeKind::Class:
16785 return getLangOpts().CPlusPlus ? NTK_NonClass : NTK_NonStruct;
16786 case TagTypeKind::Union:
16787 return NTK_NonUnion;
16788 case TagTypeKind::Enum:
16789 return NTK_NonEnum;
16790 }
16791 llvm_unreachable("invalid TTK");
16792}
16793
16794bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous,
16795 TagTypeKind NewTag, bool isDefinition,
16796 SourceLocation NewTagLoc,
16797 const IdentifierInfo *Name) {
16798 // C++ [dcl.type.elab]p3:
16799 // The class-key or enum keyword present in the
16800 // elaborated-type-specifier shall agree in kind with the
16801 // declaration to which the name in the elaborated-type-specifier
16802 // refers. This rule also applies to the form of
16803 // elaborated-type-specifier that declares a class-name or
16804 // friend class since it can be construed as referring to the
16805 // definition of the class. Thus, in any
16806 // elaborated-type-specifier, the enum keyword shall be used to
16807 // refer to an enumeration (7.2), the union class-key shall be
16808 // used to refer to a union (clause 9), and either the class or
16809 // struct class-key shall be used to refer to a class (clause 9)
16810 // declared using the class or struct class-key.
16811 TagTypeKind OldTag = Previous->getTagKind();
16812 if (OldTag != NewTag &&
16813 !(isClassCompatTagKind(Tag: OldTag) && isClassCompatTagKind(Tag: NewTag)))
16814 return false;
16815
16816 // Tags are compatible, but we might still want to warn on mismatched tags.
16817 // Non-class tags can't be mismatched at this point.
16818 if (!isClassCompatTagKind(Tag: NewTag))
16819 return true;
16820
16821 // Declarations for which -Wmismatched-tags is disabled are entirely ignored
16822 // by our warning analysis. We don't want to warn about mismatches with (eg)
16823 // declarations in system headers that are designed to be specialized, but if
16824 // a user asks us to warn, we should warn if their code contains mismatched
16825 // declarations.
16826 auto IsIgnoredLoc = [&](SourceLocation Loc) {
16827 return getDiagnostics().isIgnored(DiagID: diag::warn_struct_class_tag_mismatch,
16828 Loc);
16829 };
16830 if (IsIgnoredLoc(NewTagLoc))
16831 return true;
16832
16833 auto IsIgnored = [&](const TagDecl *Tag) {
16834 return IsIgnoredLoc(Tag->getLocation());
16835 };
16836 while (IsIgnored(Previous)) {
16837 Previous = Previous->getPreviousDecl();
16838 if (!Previous)
16839 return true;
16840 OldTag = Previous->getTagKind();
16841 }
16842
16843 bool isTemplate = false;
16844 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Val: Previous))
16845 isTemplate = Record->getDescribedClassTemplate();
16846
16847 if (inTemplateInstantiation()) {
16848 if (OldTag != NewTag) {
16849 // In a template instantiation, do not offer fix-its for tag mismatches
16850 // since they usually mess up the template instead of fixing the problem.
16851 Diag(Loc: NewTagLoc, DiagID: diag::warn_struct_class_tag_mismatch)
16852 << getRedeclDiagFromTagKind(Tag: NewTag) << isTemplate << Name
16853 << getRedeclDiagFromTagKind(Tag: OldTag);
16854 // FIXME: Note previous location?
16855 }
16856 return true;
16857 }
16858
16859 if (isDefinition) {
16860 // On definitions, check all previous tags and issue a fix-it for each
16861 // one that doesn't match the current tag.
16862 if (Previous->getDefinition()) {
16863 // Don't suggest fix-its for redefinitions.
16864 return true;
16865 }
16866
16867 bool previousMismatch = false;
16868 for (const TagDecl *I : Previous->redecls()) {
16869 if (I->getTagKind() != NewTag) {
16870 // Ignore previous declarations for which the warning was disabled.
16871 if (IsIgnored(I))
16872 continue;
16873
16874 if (!previousMismatch) {
16875 previousMismatch = true;
16876 Diag(Loc: NewTagLoc, DiagID: diag::warn_struct_class_previous_tag_mismatch)
16877 << getRedeclDiagFromTagKind(Tag: NewTag) << isTemplate << Name
16878 << getRedeclDiagFromTagKind(Tag: I->getTagKind());
16879 }
16880 Diag(Loc: I->getInnerLocStart(), DiagID: diag::note_struct_class_suggestion)
16881 << getRedeclDiagFromTagKind(Tag: NewTag)
16882 << FixItHint::CreateReplacement(RemoveRange: I->getInnerLocStart(),
16883 Code: TypeWithKeyword::getTagTypeKindName(Kind: NewTag));
16884 }
16885 }
16886 return true;
16887 }
16888
16889 // Identify the prevailing tag kind: this is the kind of the definition (if
16890 // there is a non-ignored definition), or otherwise the kind of the prior
16891 // (non-ignored) declaration.
16892 const TagDecl *PrevDef = Previous->getDefinition();
16893 if (PrevDef && IsIgnored(PrevDef))
16894 PrevDef = nullptr;
16895 const TagDecl *Redecl = PrevDef ? PrevDef : Previous;
16896 if (Redecl->getTagKind() != NewTag) {
16897 Diag(Loc: NewTagLoc, DiagID: diag::warn_struct_class_tag_mismatch)
16898 << getRedeclDiagFromTagKind(Tag: NewTag) << isTemplate << Name
16899 << getRedeclDiagFromTagKind(Tag: OldTag);
16900 Diag(Loc: Redecl->getLocation(), DiagID: diag::note_previous_use);
16901
16902 // If there is a previous definition, suggest a fix-it.
16903 if (PrevDef) {
16904 Diag(Loc: NewTagLoc, DiagID: diag::note_struct_class_suggestion)
16905 << getRedeclDiagFromTagKind(Tag: Redecl->getTagKind())
16906 << FixItHint::CreateReplacement(RemoveRange: SourceRange(NewTagLoc),
16907 Code: TypeWithKeyword::getTagTypeKindName(Kind: Redecl->getTagKind()));
16908 }
16909 }
16910
16911 return true;
16912}
16913
16914/// Add a minimal nested name specifier fixit hint to allow lookup of a tag name
16915/// from an outer enclosing namespace or file scope inside a friend declaration.
16916/// This should provide the commented out code in the following snippet:
16917/// namespace N {
16918/// struct X;
16919/// namespace M {
16920/// struct Y { friend struct /*N::*/ X; };
16921/// }
16922/// }
16923static FixItHint createFriendTagNNSFixIt(Sema &SemaRef, NamedDecl *ND, Scope *S,
16924 SourceLocation NameLoc) {
16925 // While the decl is in a namespace, do repeated lookup of that name and see
16926 // if we get the same namespace back. If we do not, continue until
16927 // translation unit scope, at which point we have a fully qualified NNS.
16928 SmallVector<IdentifierInfo *, 4> Namespaces;
16929 DeclContext *DC = ND->getDeclContext()->getRedeclContext();
16930 for (; !DC->isTranslationUnit(); DC = DC->getParent()) {
16931 // This tag should be declared in a namespace, which can only be enclosed by
16932 // other namespaces. Bail if there's an anonymous namespace in the chain.
16933 NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(Val: DC);
16934 if (!Namespace || Namespace->isAnonymousNamespace())
16935 return FixItHint();
16936 IdentifierInfo *II = Namespace->getIdentifier();
16937 Namespaces.push_back(Elt: II);
16938 NamedDecl *Lookup = SemaRef.LookupSingleName(
16939 S, Name: II, Loc: NameLoc, NameKind: Sema::LookupNestedNameSpecifierName);
16940 if (Lookup == Namespace)
16941 break;
16942 }
16943
16944 // Once we have all the namespaces, reverse them to go outermost first, and
16945 // build an NNS.
16946 SmallString<64> Insertion;
16947 llvm::raw_svector_ostream OS(Insertion);
16948 if (DC->isTranslationUnit())
16949 OS << "::";
16950 std::reverse(first: Namespaces.begin(), last: Namespaces.end());
16951 for (auto *II : Namespaces)
16952 OS << II->getName() << "::";
16953 return FixItHint::CreateInsertion(InsertionLoc: NameLoc, Code: Insertion);
16954}
16955
16956/// Determine whether a tag originally declared in context \p OldDC can
16957/// be redeclared with an unqualified name in \p NewDC (assuming name lookup
16958/// found a declaration in \p OldDC as a previous decl, perhaps through a
16959/// using-declaration).
16960static bool isAcceptableTagRedeclContext(Sema &S, DeclContext *OldDC,
16961 DeclContext *NewDC) {
16962 OldDC = OldDC->getRedeclContext();
16963 NewDC = NewDC->getRedeclContext();
16964
16965 if (OldDC->Equals(DC: NewDC))
16966 return true;
16967
16968 // In MSVC mode, we allow a redeclaration if the contexts are related (either
16969 // encloses the other).
16970 if (S.getLangOpts().MSVCCompat &&
16971 (OldDC->Encloses(DC: NewDC) || NewDC->Encloses(DC: OldDC)))
16972 return true;
16973
16974 return false;
16975}
16976
16977DeclResult
16978Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
16979 CXXScopeSpec &SS, IdentifierInfo *Name, SourceLocation NameLoc,
16980 const ParsedAttributesView &Attrs, AccessSpecifier AS,
16981 SourceLocation ModulePrivateLoc,
16982 MultiTemplateParamsArg TemplateParameterLists, bool &OwnedDecl,
16983 bool &IsDependent, SourceLocation ScopedEnumKWLoc,
16984 bool ScopedEnumUsesClassTag, TypeResult UnderlyingType,
16985 bool IsTypeSpecifier, bool IsTemplateParamOrArg,
16986 OffsetOfKind OOK, SkipBodyInfo *SkipBody) {
16987 // If this is not a definition, it must have a name.
16988 IdentifierInfo *OrigName = Name;
16989 assert((Name != nullptr || TUK == TagUseKind::Definition) &&
16990 "Nameless record must be a definition!");
16991 assert(TemplateParameterLists.size() == 0 || TUK != TagUseKind::Reference);
16992
16993 OwnedDecl = false;
16994 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TypeSpec: TagSpec);
16995 bool ScopedEnum = ScopedEnumKWLoc.isValid();
16996
16997 // FIXME: Check member specializations more carefully.
16998 bool isMemberSpecialization = false;
16999 bool Invalid = false;
17000
17001 // We only need to do this matching if we have template parameters
17002 // or a scope specifier, which also conveniently avoids this work
17003 // for non-C++ cases.
17004 if (TemplateParameterLists.size() > 0 ||
17005 (SS.isNotEmpty() && TUK != TagUseKind::Reference)) {
17006 TemplateParameterList *TemplateParams =
17007 MatchTemplateParametersToScopeSpecifier(
17008 DeclStartLoc: KWLoc, DeclLoc: NameLoc, SS, TemplateId: nullptr, ParamLists: TemplateParameterLists,
17009 IsFriend: TUK == TagUseKind::Friend, IsMemberSpecialization&: isMemberSpecialization, Invalid);
17010
17011 // C++23 [dcl.type.elab] p2:
17012 // If an elaborated-type-specifier is the sole constituent of a
17013 // declaration, the declaration is ill-formed unless it is an explicit
17014 // specialization, an explicit instantiation or it has one of the
17015 // following forms: [...]
17016 // C++23 [dcl.enum] p1:
17017 // If the enum-head-name of an opaque-enum-declaration contains a
17018 // nested-name-specifier, the declaration shall be an explicit
17019 // specialization.
17020 //
17021 // FIXME: Class template partial specializations can be forward declared
17022 // per CWG2213, but the resolution failed to allow qualified forward
17023 // declarations. This is almost certainly unintentional, so we allow them.
17024 if (TUK == TagUseKind::Declaration && SS.isNotEmpty() &&
17025 !isMemberSpecialization)
17026 Diag(Loc: SS.getBeginLoc(), DiagID: diag::err_standalone_class_nested_name_specifier)
17027 << TypeWithKeyword::getTagTypeKindName(Kind) << SS.getRange();
17028
17029 if (TemplateParams) {
17030 if (Kind == TagTypeKind::Enum) {
17031 Diag(Loc: KWLoc, DiagID: diag::err_enum_template);
17032 return true;
17033 }
17034
17035 if (TemplateParams->size() > 0) {
17036 // This is a declaration or definition of a class template (which may
17037 // be a member of another template).
17038
17039 if (Invalid)
17040 return true;
17041
17042 OwnedDecl = false;
17043 DeclResult Result = CheckClassTemplate(
17044 S, TagSpec, TUK, KWLoc, SS, Name, NameLoc, Attr: Attrs, TemplateParams,
17045 AS, ModulePrivateLoc,
17046 /*FriendLoc*/ SourceLocation(), NumOuterTemplateParamLists: TemplateParameterLists.size() - 1,
17047 OuterTemplateParamLists: TemplateParameterLists.data(), SkipBody);
17048 return Result.get();
17049 } else {
17050 // The "template<>" header is extraneous.
17051 Diag(Loc: TemplateParams->getTemplateLoc(), DiagID: diag::err_template_tag_noparams)
17052 << TypeWithKeyword::getTagTypeKindName(Kind) << Name;
17053 isMemberSpecialization = true;
17054 }
17055 }
17056
17057 if (!TemplateParameterLists.empty() && isMemberSpecialization &&
17058 CheckTemplateDeclScope(S, TemplateParams: TemplateParameterLists.back()))
17059 return true;
17060 }
17061
17062 if (TUK == TagUseKind::Friend && Kind == TagTypeKind::Enum) {
17063 // C++23 [dcl.type.elab]p4:
17064 // If an elaborated-type-specifier appears with the friend specifier as
17065 // an entire member-declaration, the member-declaration shall have one
17066 // of the following forms:
17067 // friend class-key nested-name-specifier(opt) identifier ;
17068 // friend class-key simple-template-id ;
17069 // friend class-key nested-name-specifier template(opt)
17070 // simple-template-id ;
17071 //
17072 // Since enum is not a class-key, so declarations like "friend enum E;"
17073 // are ill-formed. Although CWG2363 reaffirms that such declarations are
17074 // invalid, most implementations accept so we issue a pedantic warning.
17075 Diag(Loc: KWLoc, DiagID: diag::ext_enum_friend) << FixItHint::CreateRemoval(
17076 RemoveRange: ScopedEnum ? SourceRange(KWLoc, ScopedEnumKWLoc) : KWLoc);
17077 assert(ScopedEnum || !ScopedEnumUsesClassTag);
17078 Diag(Loc: KWLoc, DiagID: diag::note_enum_friend)
17079 << (ScopedEnum + ScopedEnumUsesClassTag);
17080 }
17081
17082 // Figure out the underlying type if this a enum declaration. We need to do
17083 // this early, because it's needed to detect if this is an incompatible
17084 // redeclaration.
17085 llvm::PointerUnion<const Type*, TypeSourceInfo*> EnumUnderlying;
17086 bool IsFixed = !UnderlyingType.isUnset() || ScopedEnum;
17087
17088 if (Kind == TagTypeKind::Enum) {
17089 if (UnderlyingType.isInvalid() || (!UnderlyingType.get() && ScopedEnum)) {
17090 // No underlying type explicitly specified, or we failed to parse the
17091 // type, default to int.
17092 EnumUnderlying = Context.IntTy.getTypePtr();
17093 } else if (UnderlyingType.get()) {
17094 // C++0x 7.2p2: The type-specifier-seq of an enum-base shall name an
17095 // integral type; any cv-qualification is ignored.
17096 TypeSourceInfo *TI = nullptr;
17097 GetTypeFromParser(Ty: UnderlyingType.get(), TInfo: &TI);
17098 EnumUnderlying = TI;
17099
17100 if (CheckEnumUnderlyingType(TI))
17101 // Recover by falling back to int.
17102 EnumUnderlying = Context.IntTy.getTypePtr();
17103
17104 if (DiagnoseUnexpandedParameterPack(Loc: TI->getTypeLoc().getBeginLoc(), T: TI,
17105 UPPC: UPPC_FixedUnderlyingType))
17106 EnumUnderlying = Context.IntTy.getTypePtr();
17107
17108 } else if (Context.getTargetInfo().getTriple().isWindowsMSVCEnvironment()) {
17109 // For MSVC ABI compatibility, unfixed enums must use an underlying type
17110 // of 'int'. However, if this is an unfixed forward declaration, don't set
17111 // the underlying type unless the user enables -fms-compatibility. This
17112 // makes unfixed forward declared enums incomplete and is more conforming.
17113 if (TUK == TagUseKind::Definition || getLangOpts().MSVCCompat)
17114 EnumUnderlying = Context.IntTy.getTypePtr();
17115 }
17116 }
17117
17118 DeclContext *SearchDC = CurContext;
17119 DeclContext *DC = CurContext;
17120 bool isStdBadAlloc = false;
17121 bool isStdAlignValT = false;
17122
17123 RedeclarationKind Redecl = forRedeclarationInCurContext();
17124 if (TUK == TagUseKind::Friend || TUK == TagUseKind::Reference)
17125 Redecl = RedeclarationKind::NotForRedeclaration;
17126
17127 /// Create a new tag decl in C/ObjC. Since the ODR-like semantics for ObjC/C
17128 /// implemented asks for structural equivalence checking, the returned decl
17129 /// here is passed back to the parser, allowing the tag body to be parsed.
17130 auto createTagFromNewDecl = [&]() -> TagDecl * {
17131 assert(!getLangOpts().CPlusPlus && "not meant for C++ usage");
17132 // If there is an identifier, use the location of the identifier as the
17133 // location of the decl, otherwise use the location of the struct/union
17134 // keyword.
17135 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
17136 TagDecl *New = nullptr;
17137
17138 if (Kind == TagTypeKind::Enum) {
17139 New = EnumDecl::Create(C&: Context, DC: SearchDC, StartLoc: KWLoc, IdLoc: Loc, Id: Name, PrevDecl: nullptr,
17140 IsScoped: ScopedEnum, IsScopedUsingClassTag: ScopedEnumUsesClassTag, IsFixed);
17141 // If this is an undefined enum, bail.
17142 if (TUK != TagUseKind::Definition && !Invalid)
17143 return nullptr;
17144 if (EnumUnderlying) {
17145 EnumDecl *ED = cast<EnumDecl>(Val: New);
17146 if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast<TypeSourceInfo *>())
17147 ED->setIntegerTypeSourceInfo(TI);
17148 else
17149 ED->setIntegerType(QualType(EnumUnderlying.get<const Type *>(), 0));
17150 QualType EnumTy = ED->getIntegerType();
17151 ED->setPromotionType(Context.isPromotableIntegerType(T: EnumTy)
17152 ? Context.getPromotedIntegerType(PromotableType: EnumTy)
17153 : EnumTy);
17154 }
17155 } else { // struct/union
17156 New = RecordDecl::Create(C: Context, TK: Kind, DC: SearchDC, StartLoc: KWLoc, IdLoc: Loc, Id: Name,
17157 PrevDecl: nullptr);
17158 }
17159
17160 if (RecordDecl *RD = dyn_cast<RecordDecl>(Val: New)) {
17161 // Add alignment attributes if necessary; these attributes are checked
17162 // when the ASTContext lays out the structure.
17163 //
17164 // It is important for implementing the correct semantics that this
17165 // happen here (in ActOnTag). The #pragma pack stack is
17166 // maintained as a result of parser callbacks which can occur at
17167 // many points during the parsing of a struct declaration (because
17168 // the #pragma tokens are effectively skipped over during the
17169 // parsing of the struct).
17170 if (TUK == TagUseKind::Definition &&
17171 (!SkipBody || !SkipBody->ShouldSkip)) {
17172 AddAlignmentAttributesForRecord(RD);
17173 AddMsStructLayoutForRecord(RD);
17174 }
17175 }
17176 New->setLexicalDeclContext(CurContext);
17177 return New;
17178 };
17179
17180 LookupResult Previous(*this, Name, NameLoc, LookupTagName, Redecl);
17181 if (Name && SS.isNotEmpty()) {
17182 // We have a nested-name tag ('struct foo::bar').
17183
17184 // Check for invalid 'foo::'.
17185 if (SS.isInvalid()) {
17186 Name = nullptr;
17187 goto CreateNewDecl;
17188 }
17189
17190 // If this is a friend or a reference to a class in a dependent
17191 // context, don't try to make a decl for it.
17192 if (TUK == TagUseKind::Friend || TUK == TagUseKind::Reference) {
17193 DC = computeDeclContext(SS, EnteringContext: false);
17194 if (!DC) {
17195 IsDependent = true;
17196 return true;
17197 }
17198 } else {
17199 DC = computeDeclContext(SS, EnteringContext: true);
17200 if (!DC) {
17201 Diag(Loc: SS.getRange().getBegin(), DiagID: diag::err_dependent_nested_name_spec)
17202 << SS.getRange();
17203 return true;
17204 }
17205 }
17206
17207 if (RequireCompleteDeclContext(SS, DC))
17208 return true;
17209
17210 SearchDC = DC;
17211 // Look-up name inside 'foo::'.
17212 LookupQualifiedName(R&: Previous, LookupCtx: DC);
17213
17214 if (Previous.isAmbiguous())
17215 return true;
17216
17217 if (Previous.empty()) {
17218 // Name lookup did not find anything. However, if the
17219 // nested-name-specifier refers to the current instantiation,
17220 // and that current instantiation has any dependent base
17221 // classes, we might find something at instantiation time: treat
17222 // this as a dependent elaborated-type-specifier.
17223 // But this only makes any sense for reference-like lookups.
17224 if (Previous.wasNotFoundInCurrentInstantiation() &&
17225 (TUK == TagUseKind::Reference || TUK == TagUseKind::Friend)) {
17226 IsDependent = true;
17227 return true;
17228 }
17229
17230 // A tag 'foo::bar' must already exist.
17231 Diag(Loc: NameLoc, DiagID: diag::err_not_tag_in_scope)
17232 << llvm::to_underlying(E: Kind) << Name << DC << SS.getRange();
17233 Name = nullptr;
17234 Invalid = true;
17235 goto CreateNewDecl;
17236 }
17237 } else if (Name) {
17238 // C++14 [class.mem]p14:
17239 // If T is the name of a class, then each of the following shall have a
17240 // name different from T:
17241 // -- every member of class T that is itself a type
17242 if (TUK != TagUseKind::Reference && TUK != TagUseKind::Friend &&
17243 DiagnoseClassNameShadow(DC: SearchDC, NameInfo: DeclarationNameInfo(Name, NameLoc)))
17244 return true;
17245
17246 // If this is a named struct, check to see if there was a previous forward
17247 // declaration or definition.
17248 // FIXME: We're looking into outer scopes here, even when we
17249 // shouldn't be. Doing so can result in ambiguities that we
17250 // shouldn't be diagnosing.
17251 LookupName(R&: Previous, S);
17252
17253 // When declaring or defining a tag, ignore ambiguities introduced
17254 // by types using'ed into this scope.
17255 if (Previous.isAmbiguous() &&
17256 (TUK == TagUseKind::Definition || TUK == TagUseKind::Declaration)) {
17257 LookupResult::Filter F = Previous.makeFilter();
17258 while (F.hasNext()) {
17259 NamedDecl *ND = F.next();
17260 if (!ND->getDeclContext()->getRedeclContext()->Equals(
17261 DC: SearchDC->getRedeclContext()))
17262 F.erase();
17263 }
17264 F.done();
17265 }
17266
17267 // C++11 [namespace.memdef]p3:
17268 // If the name in a friend declaration is neither qualified nor
17269 // a template-id and the declaration is a function or an
17270 // elaborated-type-specifier, the lookup to determine whether
17271 // the entity has been previously declared shall not consider
17272 // any scopes outside the innermost enclosing namespace.
17273 //
17274 // MSVC doesn't implement the above rule for types, so a friend tag
17275 // declaration may be a redeclaration of a type declared in an enclosing
17276 // scope. They do implement this rule for friend functions.
17277 //
17278 // Does it matter that this should be by scope instead of by
17279 // semantic context?
17280 if (!Previous.empty() && TUK == TagUseKind::Friend) {
17281 DeclContext *EnclosingNS = SearchDC->getEnclosingNamespaceContext();
17282 LookupResult::Filter F = Previous.makeFilter();
17283 bool FriendSawTagOutsideEnclosingNamespace = false;
17284 while (F.hasNext()) {
17285 NamedDecl *ND = F.next();
17286 DeclContext *DC = ND->getDeclContext()->getRedeclContext();
17287 if (DC->isFileContext() &&
17288 !EnclosingNS->Encloses(DC: ND->getDeclContext())) {
17289 if (getLangOpts().MSVCCompat)
17290 FriendSawTagOutsideEnclosingNamespace = true;
17291 else
17292 F.erase();
17293 }
17294 }
17295 F.done();
17296
17297 // Diagnose this MSVC extension in the easy case where lookup would have
17298 // unambiguously found something outside the enclosing namespace.
17299 if (Previous.isSingleResult() && FriendSawTagOutsideEnclosingNamespace) {
17300 NamedDecl *ND = Previous.getFoundDecl();
17301 Diag(Loc: NameLoc, DiagID: diag::ext_friend_tag_redecl_outside_namespace)
17302 << createFriendTagNNSFixIt(SemaRef&: *this, ND, S, NameLoc);
17303 }
17304 }
17305
17306 // Note: there used to be some attempt at recovery here.
17307 if (Previous.isAmbiguous())
17308 return true;
17309
17310 if (!getLangOpts().CPlusPlus && TUK != TagUseKind::Reference) {
17311 // FIXME: This makes sure that we ignore the contexts associated
17312 // with C structs, unions, and enums when looking for a matching
17313 // tag declaration or definition. See the similar lookup tweak
17314 // in Sema::LookupName; is there a better way to deal with this?
17315 while (isa<RecordDecl, EnumDecl, ObjCContainerDecl>(Val: SearchDC))
17316 SearchDC = SearchDC->getParent();
17317 } else if (getLangOpts().CPlusPlus) {
17318 // Inside ObjCContainer want to keep it as a lexical decl context but go
17319 // past it (most often to TranslationUnit) to find the semantic decl
17320 // context.
17321 while (isa<ObjCContainerDecl>(Val: SearchDC))
17322 SearchDC = SearchDC->getParent();
17323 }
17324 } else if (getLangOpts().CPlusPlus) {
17325 // Don't use ObjCContainerDecl as the semantic decl context for anonymous
17326 // TagDecl the same way as we skip it for named TagDecl.
17327 while (isa<ObjCContainerDecl>(Val: SearchDC))
17328 SearchDC = SearchDC->getParent();
17329 }
17330
17331 if (Previous.isSingleResult() &&
17332 Previous.getFoundDecl()->isTemplateParameter()) {
17333 // Maybe we will complain about the shadowed template parameter.
17334 DiagnoseTemplateParameterShadow(Loc: NameLoc, PrevDecl: Previous.getFoundDecl());
17335 // Just pretend that we didn't see the previous declaration.
17336 Previous.clear();
17337 }
17338
17339 if (getLangOpts().CPlusPlus && Name && DC && StdNamespace &&
17340 DC->Equals(DC: getStdNamespace())) {
17341 if (Name->isStr(Str: "bad_alloc")) {
17342 // This is a declaration of or a reference to "std::bad_alloc".
17343 isStdBadAlloc = true;
17344
17345 // If std::bad_alloc has been implicitly declared (but made invisible to
17346 // name lookup), fill in this implicit declaration as the previous
17347 // declaration, so that the declarations get chained appropriately.
17348 if (Previous.empty() && StdBadAlloc)
17349 Previous.addDecl(D: getStdBadAlloc());
17350 } else if (Name->isStr(Str: "align_val_t")) {
17351 isStdAlignValT = true;
17352 if (Previous.empty() && StdAlignValT)
17353 Previous.addDecl(D: getStdAlignValT());
17354 }
17355 }
17356
17357 // If we didn't find a previous declaration, and this is a reference
17358 // (or friend reference), move to the correct scope. In C++, we
17359 // also need to do a redeclaration lookup there, just in case
17360 // there's a shadow friend decl.
17361 if (Name && Previous.empty() &&
17362 (TUK == TagUseKind::Reference || TUK == TagUseKind::Friend ||
17363 IsTemplateParamOrArg)) {
17364 if (Invalid) goto CreateNewDecl;
17365 assert(SS.isEmpty());
17366
17367 if (TUK == TagUseKind::Reference || IsTemplateParamOrArg) {
17368 // C++ [basic.scope.pdecl]p5:
17369 // -- for an elaborated-type-specifier of the form
17370 //
17371 // class-key identifier
17372 //
17373 // if the elaborated-type-specifier is used in the
17374 // decl-specifier-seq or parameter-declaration-clause of a
17375 // function defined in namespace scope, the identifier is
17376 // declared as a class-name in the namespace that contains
17377 // the declaration; otherwise, except as a friend
17378 // declaration, the identifier is declared in the smallest
17379 // non-class, non-function-prototype scope that contains the
17380 // declaration.
17381 //
17382 // C99 6.7.2.3p8 has a similar (but not identical!) provision for
17383 // C structs and unions.
17384 //
17385 // It is an error in C++ to declare (rather than define) an enum
17386 // type, including via an elaborated type specifier. We'll
17387 // diagnose that later; for now, declare the enum in the same
17388 // scope as we would have picked for any other tag type.
17389 //
17390 // GNU C also supports this behavior as part of its incomplete
17391 // enum types extension, while GNU C++ does not.
17392 //
17393 // Find the context where we'll be declaring the tag.
17394 // FIXME: We would like to maintain the current DeclContext as the
17395 // lexical context,
17396 SearchDC = getTagInjectionContext(DC: SearchDC);
17397
17398 // Find the scope where we'll be declaring the tag.
17399 S = getTagInjectionScope(S, LangOpts: getLangOpts());
17400 } else {
17401 assert(TUK == TagUseKind::Friend);
17402 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Val: SearchDC);
17403
17404 // C++ [namespace.memdef]p3:
17405 // If a friend declaration in a non-local class first declares a
17406 // class or function, the friend class or function is a member of
17407 // the innermost enclosing namespace.
17408 SearchDC = RD->isLocalClass() ? RD->isLocalClass()
17409 : SearchDC->getEnclosingNamespaceContext();
17410 }
17411
17412 // In C++, we need to do a redeclaration lookup to properly
17413 // diagnose some problems.
17414 // FIXME: redeclaration lookup is also used (with and without C++) to find a
17415 // hidden declaration so that we don't get ambiguity errors when using a
17416 // type declared by an elaborated-type-specifier. In C that is not correct
17417 // and we should instead merge compatible types found by lookup.
17418 if (getLangOpts().CPlusPlus) {
17419 // FIXME: This can perform qualified lookups into function contexts,
17420 // which are meaningless.
17421 Previous.setRedeclarationKind(forRedeclarationInCurContext());
17422 LookupQualifiedName(R&: Previous, LookupCtx: SearchDC);
17423 } else {
17424 Previous.setRedeclarationKind(forRedeclarationInCurContext());
17425 LookupName(R&: Previous, S);
17426 }
17427 }
17428
17429 // If we have a known previous declaration to use, then use it.
17430 if (Previous.empty() && SkipBody && SkipBody->Previous)
17431 Previous.addDecl(D: SkipBody->Previous);
17432
17433 if (!Previous.empty()) {
17434 NamedDecl *PrevDecl = Previous.getFoundDecl();
17435 NamedDecl *DirectPrevDecl = Previous.getRepresentativeDecl();
17436
17437 // It's okay to have a tag decl in the same scope as a typedef
17438 // which hides a tag decl in the same scope. Finding this
17439 // with a redeclaration lookup can only actually happen in C++.
17440 //
17441 // This is also okay for elaborated-type-specifiers, which is
17442 // technically forbidden by the current standard but which is
17443 // okay according to the likely resolution of an open issue;
17444 // see http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#407
17445 if (getLangOpts().CPlusPlus) {
17446 if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(Val: PrevDecl)) {
17447 if (const TagType *TT = TD->getUnderlyingType()->getAs<TagType>()) {
17448 TagDecl *Tag = TT->getDecl();
17449 if (Tag->getDeclName() == Name &&
17450 Tag->getDeclContext()->getRedeclContext()
17451 ->Equals(DC: TD->getDeclContext()->getRedeclContext())) {
17452 PrevDecl = Tag;
17453 Previous.clear();
17454 Previous.addDecl(D: Tag);
17455 Previous.resolveKind();
17456 }
17457 }
17458 }
17459 }
17460
17461 // If this is a redeclaration of a using shadow declaration, it must
17462 // declare a tag in the same context. In MSVC mode, we allow a
17463 // redefinition if either context is within the other.
17464 if (auto *Shadow = dyn_cast<UsingShadowDecl>(Val: DirectPrevDecl)) {
17465 auto *OldTag = dyn_cast<TagDecl>(Val: PrevDecl);
17466 if (SS.isEmpty() && TUK != TagUseKind::Reference &&
17467 TUK != TagUseKind::Friend &&
17468 isDeclInScope(D: Shadow, Ctx: SearchDC, S, AllowInlineNamespace: isMemberSpecialization) &&
17469 !(OldTag && isAcceptableTagRedeclContext(
17470 S&: *this, OldDC: OldTag->getDeclContext(), NewDC: SearchDC))) {
17471 Diag(Loc: KWLoc, DiagID: diag::err_using_decl_conflict_reverse);
17472 Diag(Loc: Shadow->getTargetDecl()->getLocation(),
17473 DiagID: diag::note_using_decl_target);
17474 Diag(Loc: Shadow->getIntroducer()->getLocation(), DiagID: diag::note_using_decl)
17475 << 0;
17476 // Recover by ignoring the old declaration.
17477 Previous.clear();
17478 goto CreateNewDecl;
17479 }
17480 }
17481
17482 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(Val: PrevDecl)) {
17483 // If this is a use of a previous tag, or if the tag is already declared
17484 // in the same scope (so that the definition/declaration completes or
17485 // rementions the tag), reuse the decl.
17486 if (TUK == TagUseKind::Reference || TUK == TagUseKind::Friend ||
17487 isDeclInScope(D: DirectPrevDecl, Ctx: SearchDC, S,
17488 AllowInlineNamespace: SS.isNotEmpty() || isMemberSpecialization)) {
17489 // Make sure that this wasn't declared as an enum and now used as a
17490 // struct or something similar.
17491 if (!isAcceptableTagRedeclaration(Previous: PrevTagDecl, NewTag: Kind,
17492 isDefinition: TUK == TagUseKind::Definition, NewTagLoc: KWLoc,
17493 Name)) {
17494 bool SafeToContinue =
17495 (PrevTagDecl->getTagKind() != TagTypeKind::Enum &&
17496 Kind != TagTypeKind::Enum);
17497 if (SafeToContinue)
17498 Diag(Loc: KWLoc, DiagID: diag::err_use_with_wrong_tag)
17499 << Name
17500 << FixItHint::CreateReplacement(RemoveRange: SourceRange(KWLoc),
17501 Code: PrevTagDecl->getKindName());
17502 else
17503 Diag(Loc: KWLoc, DiagID: diag::err_use_with_wrong_tag) << Name;
17504 Diag(Loc: PrevTagDecl->getLocation(), DiagID: diag::note_previous_use);
17505
17506 if (SafeToContinue)
17507 Kind = PrevTagDecl->getTagKind();
17508 else {
17509 // Recover by making this an anonymous redefinition.
17510 Name = nullptr;
17511 Previous.clear();
17512 Invalid = true;
17513 }
17514 }
17515
17516 if (Kind == TagTypeKind::Enum &&
17517 PrevTagDecl->getTagKind() == TagTypeKind::Enum) {
17518 const EnumDecl *PrevEnum = cast<EnumDecl>(Val: PrevTagDecl);
17519 if (TUK == TagUseKind::Reference || TUK == TagUseKind::Friend)
17520 return PrevTagDecl;
17521
17522 QualType EnumUnderlyingTy;
17523 if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast<TypeSourceInfo*>())
17524 EnumUnderlyingTy = TI->getType().getUnqualifiedType();
17525 else if (const Type *T = EnumUnderlying.dyn_cast<const Type*>())
17526 EnumUnderlyingTy = QualType(T, 0);
17527
17528 // All conflicts with previous declarations are recovered by
17529 // returning the previous declaration, unless this is a definition,
17530 // in which case we want the caller to bail out.
17531 if (CheckEnumRedeclaration(EnumLoc: NameLoc.isValid() ? NameLoc : KWLoc,
17532 IsScoped: ScopedEnum, EnumUnderlyingTy,
17533 IsFixed, Prev: PrevEnum))
17534 return TUK == TagUseKind::Declaration ? PrevTagDecl : nullptr;
17535 }
17536
17537 // C++11 [class.mem]p1:
17538 // A member shall not be declared twice in the member-specification,
17539 // except that a nested class or member class template can be declared
17540 // and then later defined.
17541 if (TUK == TagUseKind::Declaration && PrevDecl->isCXXClassMember() &&
17542 S->isDeclScope(D: PrevDecl)) {
17543 Diag(Loc: NameLoc, DiagID: diag::ext_member_redeclared);
17544 Diag(Loc: PrevTagDecl->getLocation(), DiagID: diag::note_previous_declaration);
17545 }
17546
17547 if (!Invalid) {
17548 // If this is a use, just return the declaration we found, unless
17549 // we have attributes.
17550 if (TUK == TagUseKind::Reference || TUK == TagUseKind::Friend) {
17551 if (!Attrs.empty()) {
17552 // FIXME: Diagnose these attributes. For now, we create a new
17553 // declaration to hold them.
17554 } else if (TUK == TagUseKind::Reference &&
17555 (PrevTagDecl->getFriendObjectKind() ==
17556 Decl::FOK_Undeclared ||
17557 PrevDecl->getOwningModule() != getCurrentModule()) &&
17558 SS.isEmpty()) {
17559 // This declaration is a reference to an existing entity, but
17560 // has different visibility from that entity: it either makes
17561 // a friend visible or it makes a type visible in a new module.
17562 // In either case, create a new declaration. We only do this if
17563 // the declaration would have meant the same thing if no prior
17564 // declaration were found, that is, if it was found in the same
17565 // scope where we would have injected a declaration.
17566 if (!getTagInjectionContext(DC: CurContext)->getRedeclContext()
17567 ->Equals(DC: PrevDecl->getDeclContext()->getRedeclContext()))
17568 return PrevTagDecl;
17569 // This is in the injected scope, create a new declaration in
17570 // that scope.
17571 S = getTagInjectionScope(S, LangOpts: getLangOpts());
17572 } else {
17573 return PrevTagDecl;
17574 }
17575 }
17576
17577 // Diagnose attempts to redefine a tag.
17578 if (TUK == TagUseKind::Definition) {
17579 if (NamedDecl *Def = PrevTagDecl->getDefinition()) {
17580 // If we're defining a specialization and the previous definition
17581 // is from an implicit instantiation, don't emit an error
17582 // here; we'll catch this in the general case below.
17583 bool IsExplicitSpecializationAfterInstantiation = false;
17584 if (isMemberSpecialization) {
17585 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Val: Def))
17586 IsExplicitSpecializationAfterInstantiation =
17587 RD->getTemplateSpecializationKind() !=
17588 TSK_ExplicitSpecialization;
17589 else if (EnumDecl *ED = dyn_cast<EnumDecl>(Val: Def))
17590 IsExplicitSpecializationAfterInstantiation =
17591 ED->getTemplateSpecializationKind() !=
17592 TSK_ExplicitSpecialization;
17593 }
17594
17595 // Note that clang allows ODR-like semantics for ObjC/C, i.e., do
17596 // not keep more that one definition around (merge them). However,
17597 // ensure the decl passes the structural compatibility check in
17598 // C11 6.2.7/1 (or 6.1.2.6/1 in C89).
17599 NamedDecl *Hidden = nullptr;
17600 if (SkipBody && !hasVisibleDefinition(D: Def, Suggested: &Hidden)) {
17601 // There is a definition of this tag, but it is not visible. We
17602 // explicitly make use of C++'s one definition rule here, and
17603 // assume that this definition is identical to the hidden one
17604 // we already have. Make the existing definition visible and
17605 // use it in place of this one.
17606 if (!getLangOpts().CPlusPlus) {
17607 // Postpone making the old definition visible until after we
17608 // complete parsing the new one and do the structural
17609 // comparison.
17610 SkipBody->CheckSameAsPrevious = true;
17611 SkipBody->New = createTagFromNewDecl();
17612 SkipBody->Previous = Def;
17613 return Def;
17614 } else {
17615 SkipBody->ShouldSkip = true;
17616 SkipBody->Previous = Def;
17617 makeMergedDefinitionVisible(ND: Hidden);
17618 // Carry on and handle it like a normal definition. We'll
17619 // skip starting the definition later.
17620 }
17621 } else if (!IsExplicitSpecializationAfterInstantiation) {
17622 // A redeclaration in function prototype scope in C isn't
17623 // visible elsewhere, so merely issue a warning.
17624 if (!getLangOpts().CPlusPlus && S->containedInPrototypeScope())
17625 Diag(Loc: NameLoc, DiagID: diag::warn_redefinition_in_param_list) << Name;
17626 else
17627 Diag(Loc: NameLoc, DiagID: diag::err_redefinition) << Name;
17628 notePreviousDefinition(Old: Def,
17629 New: NameLoc.isValid() ? NameLoc : KWLoc);
17630 // If this is a redefinition, recover by making this
17631 // struct be anonymous, which will make any later
17632 // references get the previous definition.
17633 Name = nullptr;
17634 Previous.clear();
17635 Invalid = true;
17636 }
17637 } else {
17638 // If the type is currently being defined, complain
17639 // about a nested redefinition.
17640 auto *TD = Context.getTagDeclType(Decl: PrevTagDecl)->getAsTagDecl();
17641 if (TD->isBeingDefined()) {
17642 Diag(Loc: NameLoc, DiagID: diag::err_nested_redefinition) << Name;
17643 Diag(Loc: PrevTagDecl->getLocation(),
17644 DiagID: diag::note_previous_definition);
17645 Name = nullptr;
17646 Previous.clear();
17647 Invalid = true;
17648 }
17649 }
17650
17651 // Okay, this is definition of a previously declared or referenced
17652 // tag. We're going to create a new Decl for it.
17653 }
17654
17655 // Okay, we're going to make a redeclaration. If this is some kind
17656 // of reference, make sure we build the redeclaration in the same DC
17657 // as the original, and ignore the current access specifier.
17658 if (TUK == TagUseKind::Friend || TUK == TagUseKind::Reference) {
17659 SearchDC = PrevTagDecl->getDeclContext();
17660 AS = AS_none;
17661 }
17662 }
17663 // If we get here we have (another) forward declaration or we
17664 // have a definition. Just create a new decl.
17665
17666 } else {
17667 // If we get here, this is a definition of a new tag type in a nested
17668 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a
17669 // new decl/type. We set PrevDecl to NULL so that the entities
17670 // have distinct types.
17671 Previous.clear();
17672 }
17673 // If we get here, we're going to create a new Decl. If PrevDecl
17674 // is non-NULL, it's a definition of the tag declared by
17675 // PrevDecl. If it's NULL, we have a new definition.
17676
17677 // Otherwise, PrevDecl is not a tag, but was found with tag
17678 // lookup. This is only actually possible in C++, where a few
17679 // things like templates still live in the tag namespace.
17680 } else {
17681 // Use a better diagnostic if an elaborated-type-specifier
17682 // found the wrong kind of type on the first
17683 // (non-redeclaration) lookup.
17684 if ((TUK == TagUseKind::Reference || TUK == TagUseKind::Friend) &&
17685 !Previous.isForRedeclaration()) {
17686 NonTagKind NTK = getNonTagTypeDeclKind(PrevDecl, TTK: Kind);
17687 Diag(Loc: NameLoc, DiagID: diag::err_tag_reference_non_tag)
17688 << PrevDecl << NTK << llvm::to_underlying(E: Kind);
17689 Diag(Loc: PrevDecl->getLocation(), DiagID: diag::note_declared_at);
17690 Invalid = true;
17691
17692 // Otherwise, only diagnose if the declaration is in scope.
17693 } else if (!isDeclInScope(D: DirectPrevDecl, Ctx: SearchDC, S,
17694 AllowInlineNamespace: SS.isNotEmpty() || isMemberSpecialization)) {
17695 // do nothing
17696
17697 // Diagnose implicit declarations introduced by elaborated types.
17698 } else if (TUK == TagUseKind::Reference || TUK == TagUseKind::Friend) {
17699 NonTagKind NTK = getNonTagTypeDeclKind(PrevDecl, TTK: Kind);
17700 Diag(Loc: NameLoc, DiagID: diag::err_tag_reference_conflict) << NTK;
17701 Diag(Loc: PrevDecl->getLocation(), DiagID: diag::note_previous_decl) << PrevDecl;
17702 Invalid = true;
17703
17704 // Otherwise it's a declaration. Call out a particularly common
17705 // case here.
17706 } else if (TypedefNameDecl *TND = dyn_cast<TypedefNameDecl>(Val: PrevDecl)) {
17707 unsigned Kind = 0;
17708 if (isa<TypeAliasDecl>(Val: PrevDecl)) Kind = 1;
17709 Diag(Loc: NameLoc, DiagID: diag::err_tag_definition_of_typedef)
17710 << Name << Kind << TND->getUnderlyingType();
17711 Diag(Loc: PrevDecl->getLocation(), DiagID: diag::note_previous_decl) << PrevDecl;
17712 Invalid = true;
17713
17714 // Otherwise, diagnose.
17715 } else {
17716 // The tag name clashes with something else in the target scope,
17717 // issue an error and recover by making this tag be anonymous.
17718 Diag(Loc: NameLoc, DiagID: diag::err_redefinition_different_kind) << Name;
17719 notePreviousDefinition(Old: PrevDecl, New: NameLoc);
17720 Name = nullptr;
17721 Invalid = true;
17722 }
17723
17724 // The existing declaration isn't relevant to us; we're in a
17725 // new scope, so clear out the previous declaration.
17726 Previous.clear();
17727 }
17728 }
17729
17730CreateNewDecl:
17731
17732 TagDecl *PrevDecl = nullptr;
17733 if (Previous.isSingleResult())
17734 PrevDecl = cast<TagDecl>(Val: Previous.getFoundDecl());
17735
17736 // If there is an identifier, use the location of the identifier as the
17737 // location of the decl, otherwise use the location of the struct/union
17738 // keyword.
17739 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
17740
17741 // Otherwise, create a new declaration. If there is a previous
17742 // declaration of the same entity, the two will be linked via
17743 // PrevDecl.
17744 TagDecl *New;
17745
17746 if (Kind == TagTypeKind::Enum) {
17747 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
17748 // enum X { A, B, C } D; D should chain to X.
17749 New = EnumDecl::Create(C&: Context, DC: SearchDC, StartLoc: KWLoc, IdLoc: Loc, Id: Name,
17750 PrevDecl: cast_or_null<EnumDecl>(Val: PrevDecl), IsScoped: ScopedEnum,
17751 IsScopedUsingClassTag: ScopedEnumUsesClassTag, IsFixed);
17752
17753 if (isStdAlignValT && (!StdAlignValT || getStdAlignValT()->isImplicit()))
17754 StdAlignValT = cast<EnumDecl>(Val: New);
17755
17756 // If this is an undefined enum, warn.
17757 if (TUK != TagUseKind::Definition && !Invalid) {
17758 TagDecl *Def;
17759 if (IsFixed && cast<EnumDecl>(Val: New)->isFixed()) {
17760 // C++0x: 7.2p2: opaque-enum-declaration.
17761 // Conflicts are diagnosed above. Do nothing.
17762 }
17763 else if (PrevDecl && (Def = cast<EnumDecl>(Val: PrevDecl)->getDefinition())) {
17764 Diag(Loc, DiagID: diag::ext_forward_ref_enum_def)
17765 << New;
17766 Diag(Loc: Def->getLocation(), DiagID: diag::note_previous_definition);
17767 } else {
17768 unsigned DiagID = diag::ext_forward_ref_enum;
17769 if (getLangOpts().MSVCCompat)
17770 DiagID = diag::ext_ms_forward_ref_enum;
17771 else if (getLangOpts().CPlusPlus)
17772 DiagID = diag::err_forward_ref_enum;
17773 Diag(Loc, DiagID);
17774 }
17775 }
17776
17777 if (EnumUnderlying) {
17778 EnumDecl *ED = cast<EnumDecl>(Val: New);
17779 if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast<TypeSourceInfo*>())
17780 ED->setIntegerTypeSourceInfo(TI);
17781 else
17782 ED->setIntegerType(QualType(EnumUnderlying.get<const Type *>(), 0));
17783 QualType EnumTy = ED->getIntegerType();
17784 ED->setPromotionType(Context.isPromotableIntegerType(T: EnumTy)
17785 ? Context.getPromotedIntegerType(PromotableType: EnumTy)
17786 : EnumTy);
17787 assert(ED->isComplete() && "enum with type should be complete");
17788 }
17789 } else {
17790 // struct/union/class
17791
17792 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
17793 // struct X { int A; } D; D should chain to X.
17794 if (getLangOpts().CPlusPlus) {
17795 // FIXME: Look for a way to use RecordDecl for simple structs.
17796 New = CXXRecordDecl::Create(C: Context, TK: Kind, DC: SearchDC, StartLoc: KWLoc, IdLoc: Loc, Id: Name,
17797 PrevDecl: cast_or_null<CXXRecordDecl>(Val: PrevDecl));
17798
17799 if (isStdBadAlloc && (!StdBadAlloc || getStdBadAlloc()->isImplicit()))
17800 StdBadAlloc = cast<CXXRecordDecl>(Val: New);
17801 } else
17802 New = RecordDecl::Create(C: Context, TK: Kind, DC: SearchDC, StartLoc: KWLoc, IdLoc: Loc, Id: Name,
17803 PrevDecl: cast_or_null<RecordDecl>(Val: PrevDecl));
17804 }
17805
17806 // Only C23 and later allow defining new types in 'offsetof()'.
17807 if (OOK != OOK_Outside && TUK == TagUseKind::Definition &&
17808 !getLangOpts().CPlusPlus && !getLangOpts().C23)
17809 Diag(Loc: New->getLocation(), DiagID: diag::ext_type_defined_in_offsetof)
17810 << (OOK == OOK_Macro) << New->getSourceRange();
17811
17812 // C++11 [dcl.type]p3:
17813 // A type-specifier-seq shall not define a class or enumeration [...].
17814 if (!Invalid && getLangOpts().CPlusPlus &&
17815 (IsTypeSpecifier || IsTemplateParamOrArg) &&
17816 TUK == TagUseKind::Definition) {
17817 Diag(Loc: New->getLocation(), DiagID: diag::err_type_defined_in_type_specifier)
17818 << Context.getTagDeclType(Decl: New);
17819 Invalid = true;
17820 }
17821
17822 if (!Invalid && getLangOpts().CPlusPlus && TUK == TagUseKind::Definition &&
17823 DC->getDeclKind() == Decl::Enum) {
17824 Diag(Loc: New->getLocation(), DiagID: diag::err_type_defined_in_enum)
17825 << Context.getTagDeclType(Decl: New);
17826 Invalid = true;
17827 }
17828
17829 // Maybe add qualifier info.
17830 if (SS.isNotEmpty()) {
17831 if (SS.isSet()) {
17832 // If this is either a declaration or a definition, check the
17833 // nested-name-specifier against the current context.
17834 if ((TUK == TagUseKind::Definition || TUK == TagUseKind::Declaration) &&
17835 diagnoseQualifiedDeclaration(SS, DC, Name: OrigName, Loc,
17836 /*TemplateId=*/nullptr,
17837 IsMemberSpecialization: isMemberSpecialization))
17838 Invalid = true;
17839
17840 New->setQualifierInfo(SS.getWithLocInContext(Context));
17841 if (TemplateParameterLists.size() > 0) {
17842 New->setTemplateParameterListsInfo(Context, TPLists: TemplateParameterLists);
17843 }
17844 }
17845 else
17846 Invalid = true;
17847 }
17848
17849 if (RecordDecl *RD = dyn_cast<RecordDecl>(Val: New)) {
17850 // Add alignment attributes if necessary; these attributes are checked when
17851 // the ASTContext lays out the structure.
17852 //
17853 // It is important for implementing the correct semantics that this
17854 // happen here (in ActOnTag). The #pragma pack stack is
17855 // maintained as a result of parser callbacks which can occur at
17856 // many points during the parsing of a struct declaration (because
17857 // the #pragma tokens are effectively skipped over during the
17858 // parsing of the struct).
17859 if (TUK == TagUseKind::Definition && (!SkipBody || !SkipBody->ShouldSkip)) {
17860 AddAlignmentAttributesForRecord(RD);
17861 AddMsStructLayoutForRecord(RD);
17862 }
17863 }
17864
17865 if (ModulePrivateLoc.isValid()) {
17866 if (isMemberSpecialization)
17867 Diag(Loc: New->getLocation(), DiagID: diag::err_module_private_specialization)
17868 << 2
17869 << FixItHint::CreateRemoval(RemoveRange: ModulePrivateLoc);
17870 // __module_private__ does not apply to local classes. However, we only
17871 // diagnose this as an error when the declaration specifiers are
17872 // freestanding. Here, we just ignore the __module_private__.
17873 else if (!SearchDC->isFunctionOrMethod())
17874 New->setModulePrivate();
17875 }
17876
17877 // If this is a specialization of a member class (of a class template),
17878 // check the specialization.
17879 if (isMemberSpecialization && CheckMemberSpecialization(Member: New, Previous))
17880 Invalid = true;
17881
17882 // If we're declaring or defining a tag in function prototype scope in C,
17883 // note that this type can only be used within the function and add it to
17884 // the list of decls to inject into the function definition scope.
17885 if ((Name || Kind == TagTypeKind::Enum) &&
17886 getNonFieldDeclScope(S)->isFunctionPrototypeScope()) {
17887 if (getLangOpts().CPlusPlus) {
17888 // C++ [dcl.fct]p6:
17889 // Types shall not be defined in return or parameter types.
17890 if (TUK == TagUseKind::Definition && !IsTypeSpecifier) {
17891 Diag(Loc, DiagID: diag::err_type_defined_in_param_type)
17892 << Name;
17893 Invalid = true;
17894 }
17895 } else if (!PrevDecl) {
17896 Diag(Loc, DiagID: diag::warn_decl_in_param_list) << Context.getTagDeclType(Decl: New);
17897 }
17898 }
17899
17900 if (Invalid)
17901 New->setInvalidDecl();
17902
17903 // Set the lexical context. If the tag has a C++ scope specifier, the
17904 // lexical context will be different from the semantic context.
17905 New->setLexicalDeclContext(CurContext);
17906
17907 // Mark this as a friend decl if applicable.
17908 // In Microsoft mode, a friend declaration also acts as a forward
17909 // declaration so we always pass true to setObjectOfFriendDecl to make
17910 // the tag name visible.
17911 if (TUK == TagUseKind::Friend)
17912 New->setObjectOfFriendDecl(getLangOpts().MSVCCompat);
17913
17914 // Set the access specifier.
17915 if (!Invalid && SearchDC->isRecord())
17916 SetMemberAccessSpecifier(MemberDecl: New, PrevMemberDecl: PrevDecl, LexicalAS: AS);
17917
17918 if (PrevDecl)
17919 CheckRedeclarationInModule(New, Old: PrevDecl);
17920
17921 if (TUK == TagUseKind::Definition && (!SkipBody || !SkipBody->ShouldSkip))
17922 New->startDefinition();
17923
17924 ProcessDeclAttributeList(S, D: New, AttrList: Attrs);
17925 AddPragmaAttributes(S, D: New);
17926
17927 // If this has an identifier, add it to the scope stack.
17928 if (TUK == TagUseKind::Friend) {
17929 // We might be replacing an existing declaration in the lookup tables;
17930 // if so, borrow its access specifier.
17931 if (PrevDecl)
17932 New->setAccess(PrevDecl->getAccess());
17933
17934 DeclContext *DC = New->getDeclContext()->getRedeclContext();
17935 DC->makeDeclVisibleInContext(D: New);
17936 if (Name) // can be null along some error paths
17937 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
17938 PushOnScopeChains(D: New, S: EnclosingScope, /* AddToContext = */ false);
17939 } else if (Name) {
17940 S = getNonFieldDeclScope(S);
17941 PushOnScopeChains(D: New, S, AddToContext: true);
17942 } else {
17943 CurContext->addDecl(D: New);
17944 }
17945
17946 // If this is the C FILE type, notify the AST context.
17947 if (IdentifierInfo *II = New->getIdentifier())
17948 if (!New->isInvalidDecl() &&
17949 New->getDeclContext()->getRedeclContext()->isTranslationUnit() &&
17950 II->isStr(Str: "FILE"))
17951 Context.setFILEDecl(New);
17952
17953 if (PrevDecl)
17954 mergeDeclAttributes(New, Old: PrevDecl);
17955
17956 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(Val: New)) {
17957 inferGslOwnerPointerAttribute(Record: CXXRD);
17958 inferNullableClassAttribute(CRD: CXXRD);
17959 }
17960
17961 // If there's a #pragma GCC visibility in scope, set the visibility of this
17962 // record.
17963 AddPushedVisibilityAttribute(RD: New);
17964
17965 if (isMemberSpecialization && !New->isInvalidDecl())
17966 CompleteMemberSpecialization(Member: New, Previous);
17967
17968 OwnedDecl = true;
17969 // In C++, don't return an invalid declaration. We can't recover well from
17970 // the cases where we make the type anonymous.
17971 if (Invalid && getLangOpts().CPlusPlus) {
17972 if (New->isBeingDefined())
17973 if (auto RD = dyn_cast<RecordDecl>(Val: New))
17974 RD->completeDefinition();
17975 return true;
17976 } else if (SkipBody && SkipBody->ShouldSkip) {
17977 return SkipBody->Previous;
17978 } else {
17979 return New;
17980 }
17981}
17982
17983void Sema::ActOnTagStartDefinition(Scope *S, Decl *TagD) {
17984 AdjustDeclIfTemplate(Decl&: TagD);
17985 TagDecl *Tag = cast<TagDecl>(Val: TagD);
17986
17987 // Enter the tag context.
17988 PushDeclContext(S, DC: Tag);
17989
17990 ActOnDocumentableDecl(D: TagD);
17991
17992 // If there's a #pragma GCC visibility in scope, set the visibility of this
17993 // record.
17994 AddPushedVisibilityAttribute(RD: Tag);
17995}
17996
17997bool Sema::ActOnDuplicateDefinition(Decl *Prev, SkipBodyInfo &SkipBody) {
17998 if (!hasStructuralCompatLayout(D: Prev, Suggested: SkipBody.New))
17999 return false;
18000
18001 // Make the previous decl visible.
18002 makeMergedDefinitionVisible(ND: SkipBody.Previous);
18003 return true;
18004}
18005
18006void Sema::ActOnStartCXXMemberDeclarations(Scope *S, Decl *TagD,
18007 SourceLocation FinalLoc,
18008 bool IsFinalSpelledSealed,
18009 bool IsAbstract,
18010 SourceLocation LBraceLoc) {
18011 AdjustDeclIfTemplate(Decl&: TagD);
18012 CXXRecordDecl *Record = cast<CXXRecordDecl>(Val: TagD);
18013
18014 FieldCollector->StartClass();
18015
18016 if (!Record->getIdentifier())
18017 return;
18018
18019 if (IsAbstract)
18020 Record->markAbstract();
18021
18022 if (FinalLoc.isValid()) {
18023 Record->addAttr(A: FinalAttr::Create(Ctx&: Context, Range: FinalLoc,
18024 S: IsFinalSpelledSealed
18025 ? FinalAttr::Keyword_sealed
18026 : FinalAttr::Keyword_final));
18027 }
18028 // C++ [class]p2:
18029 // [...] The class-name is also inserted into the scope of the
18030 // class itself; this is known as the injected-class-name. For
18031 // purposes of access checking, the injected-class-name is treated
18032 // as if it were a public member name.
18033 CXXRecordDecl *InjectedClassName = CXXRecordDecl::Create(
18034 C: Context, TK: Record->getTagKind(), DC: CurContext, StartLoc: Record->getBeginLoc(),
18035 IdLoc: Record->getLocation(), Id: Record->getIdentifier(),
18036 /*PrevDecl=*/nullptr,
18037 /*DelayTypeCreation=*/true);
18038 Context.getTypeDeclType(Decl: InjectedClassName, PrevDecl: Record);
18039 InjectedClassName->setImplicit();
18040 InjectedClassName->setAccess(AS_public);
18041 if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate())
18042 InjectedClassName->setDescribedClassTemplate(Template);
18043 PushOnScopeChains(D: InjectedClassName, S);
18044 assert(InjectedClassName->isInjectedClassName() &&
18045 "Broken injected-class-name");
18046}
18047
18048void Sema::ActOnTagFinishDefinition(Scope *S, Decl *TagD,
18049 SourceRange BraceRange) {
18050 AdjustDeclIfTemplate(Decl&: TagD);
18051 TagDecl *Tag = cast<TagDecl>(Val: TagD);
18052 Tag->setBraceRange(BraceRange);
18053
18054 // Make sure we "complete" the definition even it is invalid.
18055 if (Tag->isBeingDefined()) {
18056 assert(Tag->isInvalidDecl() && "We should already have completed it");
18057 if (RecordDecl *RD = dyn_cast<RecordDecl>(Val: Tag))
18058 RD->completeDefinition();
18059 }
18060
18061 if (auto *RD = dyn_cast<CXXRecordDecl>(Val: Tag)) {
18062 FieldCollector->FinishClass();
18063 if (RD->hasAttr<SYCLSpecialClassAttr>()) {
18064 auto *Def = RD->getDefinition();
18065 assert(Def && "The record is expected to have a completed definition");
18066 unsigned NumInitMethods = 0;
18067 for (auto *Method : Def->methods()) {
18068 if (!Method->getIdentifier())
18069 continue;
18070 if (Method->getName() == "__init")
18071 NumInitMethods++;
18072 }
18073 if (NumInitMethods > 1 || !Def->hasInitMethod())
18074 Diag(Loc: RD->getLocation(), DiagID: diag::err_sycl_special_type_num_init_method);
18075 }
18076
18077 // If we're defining a dynamic class in a module interface unit, we always
18078 // need to produce the vtable for it, even if the vtable is not used in the
18079 // current TU.
18080 //
18081 // The case where the current class is not dynamic is handled in
18082 // MarkVTableUsed.
18083 if (getCurrentModule() && getCurrentModule()->isInterfaceOrPartition())
18084 MarkVTableUsed(Loc: RD->getLocation(), Class: RD, /*DefinitionRequired=*/true);
18085 }
18086
18087 // Exit this scope of this tag's definition.
18088 PopDeclContext();
18089
18090 if (getCurLexicalContext()->isObjCContainer() &&
18091 Tag->getDeclContext()->isFileContext())
18092 Tag->setTopLevelDeclInObjCContainer();
18093
18094 // Notify the consumer that we've defined a tag.
18095 if (!Tag->isInvalidDecl())
18096 Consumer.HandleTagDeclDefinition(D: Tag);
18097
18098 // Clangs implementation of #pragma align(packed) differs in bitfield layout
18099 // from XLs and instead matches the XL #pragma pack(1) behavior.
18100 if (Context.getTargetInfo().getTriple().isOSAIX() &&
18101 AlignPackStack.hasValue()) {
18102 AlignPackInfo APInfo = AlignPackStack.CurrentValue;
18103 // Only diagnose #pragma align(packed).
18104 if (!APInfo.IsAlignAttr() || APInfo.getAlignMode() != AlignPackInfo::Packed)
18105 return;
18106 const RecordDecl *RD = dyn_cast<RecordDecl>(Val: Tag);
18107 if (!RD)
18108 return;
18109 // Only warn if there is at least 1 bitfield member.
18110 if (llvm::any_of(Range: RD->fields(),
18111 P: [](const FieldDecl *FD) { return FD->isBitField(); }))
18112 Diag(Loc: BraceRange.getBegin(), DiagID: diag::warn_pragma_align_not_xl_compatible);
18113 }
18114}
18115
18116void Sema::ActOnTagDefinitionError(Scope *S, Decl *TagD) {
18117 AdjustDeclIfTemplate(Decl&: TagD);
18118 TagDecl *Tag = cast<TagDecl>(Val: TagD);
18119 Tag->setInvalidDecl();
18120
18121 // Make sure we "complete" the definition even it is invalid.
18122 if (Tag->isBeingDefined()) {
18123 if (RecordDecl *RD = dyn_cast<RecordDecl>(Val: Tag))
18124 RD->completeDefinition();
18125 }
18126
18127 // We're undoing ActOnTagStartDefinition here, not
18128 // ActOnStartCXXMemberDeclarations, so we don't have to mess with
18129 // the FieldCollector.
18130
18131 PopDeclContext();
18132}
18133
18134// Note that FieldName may be null for anonymous bitfields.
18135ExprResult Sema::VerifyBitField(SourceLocation FieldLoc,
18136 const IdentifierInfo *FieldName,
18137 QualType FieldTy, bool IsMsStruct,
18138 Expr *BitWidth) {
18139 assert(BitWidth);
18140 if (BitWidth->containsErrors())
18141 return ExprError();
18142
18143 // C99 6.7.2.1p4 - verify the field type.
18144 // C++ 9.6p3: A bit-field shall have integral or enumeration type.
18145 if (!FieldTy->isDependentType() && !FieldTy->isIntegralOrEnumerationType()) {
18146 // Handle incomplete and sizeless types with a specific error.
18147 if (RequireCompleteSizedType(Loc: FieldLoc, T: FieldTy,
18148 DiagID: diag::err_field_incomplete_or_sizeless))
18149 return ExprError();
18150 if (FieldName)
18151 return Diag(Loc: FieldLoc, DiagID: diag::err_not_integral_type_bitfield)
18152 << FieldName << FieldTy << BitWidth->getSourceRange();
18153 return Diag(Loc: FieldLoc, DiagID: diag::err_not_integral_type_anon_bitfield)
18154 << FieldTy << BitWidth->getSourceRange();
18155 } else if (DiagnoseUnexpandedParameterPack(E: const_cast<Expr *>(BitWidth),
18156 UPPC: UPPC_BitFieldWidth))
18157 return ExprError();
18158
18159 // If the bit-width is type- or value-dependent, don't try to check
18160 // it now.
18161 if (BitWidth->isValueDependent() || BitWidth->isTypeDependent())
18162 return BitWidth;
18163
18164 llvm::APSInt Value;
18165 ExprResult ICE = VerifyIntegerConstantExpression(E: BitWidth, Result: &Value, CanFold: AllowFold);
18166 if (ICE.isInvalid())
18167 return ICE;
18168 BitWidth = ICE.get();
18169
18170 // Zero-width bitfield is ok for anonymous field.
18171 if (Value == 0 && FieldName)
18172 return Diag(Loc: FieldLoc, DiagID: diag::err_bitfield_has_zero_width)
18173 << FieldName << BitWidth->getSourceRange();
18174
18175 if (Value.isSigned() && Value.isNegative()) {
18176 if (FieldName)
18177 return Diag(Loc: FieldLoc, DiagID: diag::err_bitfield_has_negative_width)
18178 << FieldName << toString(I: Value, Radix: 10);
18179 return Diag(Loc: FieldLoc, DiagID: diag::err_anon_bitfield_has_negative_width)
18180 << toString(I: Value, Radix: 10);
18181 }
18182
18183 // The size of the bit-field must not exceed our maximum permitted object
18184 // size.
18185 if (Value.getActiveBits() > ConstantArrayType::getMaxSizeBits(Context)) {
18186 return Diag(Loc: FieldLoc, DiagID: diag::err_bitfield_too_wide)
18187 << !FieldName << FieldName << toString(I: Value, Radix: 10);
18188 }
18189
18190 if (!FieldTy->isDependentType()) {
18191 uint64_t TypeStorageSize = Context.getTypeSize(T: FieldTy);
18192 uint64_t TypeWidth = Context.getIntWidth(T: FieldTy);
18193 bool BitfieldIsOverwide = Value.ugt(RHS: TypeWidth);
18194
18195 // Over-wide bitfields are an error in C or when using the MSVC bitfield
18196 // ABI.
18197 bool CStdConstraintViolation =
18198 BitfieldIsOverwide && !getLangOpts().CPlusPlus;
18199 bool MSBitfieldViolation =
18200 Value.ugt(RHS: TypeStorageSize) &&
18201 (IsMsStruct || Context.getTargetInfo().getCXXABI().isMicrosoft());
18202 if (CStdConstraintViolation || MSBitfieldViolation) {
18203 unsigned DiagWidth =
18204 CStdConstraintViolation ? TypeWidth : TypeStorageSize;
18205 return Diag(Loc: FieldLoc, DiagID: diag::err_bitfield_width_exceeds_type_width)
18206 << (bool)FieldName << FieldName << toString(I: Value, Radix: 10)
18207 << !CStdConstraintViolation << DiagWidth;
18208 }
18209
18210 // Warn on types where the user might conceivably expect to get all
18211 // specified bits as value bits: that's all integral types other than
18212 // 'bool'.
18213 if (BitfieldIsOverwide && !FieldTy->isBooleanType() && FieldName) {
18214 Diag(Loc: FieldLoc, DiagID: diag::warn_bitfield_width_exceeds_type_width)
18215 << FieldName << toString(I: Value, Radix: 10)
18216 << (unsigned)TypeWidth;
18217 }
18218 }
18219
18220 return BitWidth;
18221}
18222
18223Decl *Sema::ActOnField(Scope *S, Decl *TagD, SourceLocation DeclStart,
18224 Declarator &D, Expr *BitfieldWidth) {
18225 FieldDecl *Res = HandleField(S, TagD: cast_if_present<RecordDecl>(Val: TagD), DeclStart,
18226 D, BitfieldWidth,
18227 /*InitStyle=*/ICIS_NoInit, AS: AS_public);
18228 return Res;
18229}
18230
18231FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record,
18232 SourceLocation DeclStart,
18233 Declarator &D, Expr *BitWidth,
18234 InClassInitStyle InitStyle,
18235 AccessSpecifier AS) {
18236 if (D.isDecompositionDeclarator()) {
18237 const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator();
18238 Diag(Loc: Decomp.getLSquareLoc(), DiagID: diag::err_decomp_decl_context)
18239 << Decomp.getSourceRange();
18240 return nullptr;
18241 }
18242
18243 const IdentifierInfo *II = D.getIdentifier();
18244 SourceLocation Loc = DeclStart;
18245 if (II) Loc = D.getIdentifierLoc();
18246
18247 TypeSourceInfo *TInfo = GetTypeForDeclarator(D);
18248 QualType T = TInfo->getType();
18249 if (getLangOpts().CPlusPlus) {
18250 CheckExtraCXXDefaultArguments(D);
18251
18252 if (DiagnoseUnexpandedParameterPack(Loc: D.getIdentifierLoc(), T: TInfo,
18253 UPPC: UPPC_DataMemberType)) {
18254 D.setInvalidType();
18255 T = Context.IntTy;
18256 TInfo = Context.getTrivialTypeSourceInfo(T, Loc);
18257 }
18258 }
18259
18260 DiagnoseFunctionSpecifiers(DS: D.getDeclSpec());
18261
18262 if (D.getDeclSpec().isInlineSpecified())
18263 Diag(Loc: D.getDeclSpec().getInlineSpecLoc(), DiagID: diag::err_inline_non_function)
18264 << getLangOpts().CPlusPlus17;
18265 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
18266 Diag(Loc: D.getDeclSpec().getThreadStorageClassSpecLoc(),
18267 DiagID: diag::err_invalid_thread)
18268 << DeclSpec::getSpecifierName(S: TSCS);
18269
18270 // Check to see if this name was declared as a member previously
18271 NamedDecl *PrevDecl = nullptr;
18272 LookupResult Previous(*this, II, Loc, LookupMemberName,
18273 RedeclarationKind::ForVisibleRedeclaration);
18274 LookupName(R&: Previous, S);
18275 switch (Previous.getResultKind()) {
18276 case LookupResult::Found:
18277 case LookupResult::FoundUnresolvedValue:
18278 PrevDecl = Previous.getAsSingle<NamedDecl>();
18279 break;
18280
18281 case LookupResult::FoundOverloaded:
18282 PrevDecl = Previous.getRepresentativeDecl();
18283 break;
18284
18285 case LookupResult::NotFound:
18286 case LookupResult::NotFoundInCurrentInstantiation:
18287 case LookupResult::Ambiguous:
18288 break;
18289 }
18290 Previous.suppressDiagnostics();
18291
18292 if (PrevDecl && PrevDecl->isTemplateParameter()) {
18293 // Maybe we will complain about the shadowed template parameter.
18294 DiagnoseTemplateParameterShadow(Loc: D.getIdentifierLoc(), PrevDecl);
18295 // Just pretend that we didn't see the previous declaration.
18296 PrevDecl = nullptr;
18297 }
18298
18299 if (PrevDecl && !isDeclInScope(D: PrevDecl, Ctx: Record, S))
18300 PrevDecl = nullptr;
18301
18302 bool Mutable
18303 = (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable);
18304 SourceLocation TSSL = D.getBeginLoc();
18305 FieldDecl *NewFD
18306 = CheckFieldDecl(Name: II, T, TInfo, Record, Loc, Mutable, BitfieldWidth: BitWidth, InitStyle,
18307 TSSL, AS, PrevDecl, D: &D);
18308
18309 if (NewFD->isInvalidDecl())
18310 Record->setInvalidDecl();
18311
18312 if (D.getDeclSpec().isModulePrivateSpecified())
18313 NewFD->setModulePrivate();
18314
18315 if (NewFD->isInvalidDecl() && PrevDecl) {
18316 // Don't introduce NewFD into scope; there's already something
18317 // with the same name in the same scope.
18318 } else if (II) {
18319 PushOnScopeChains(D: NewFD, S);
18320 } else
18321 Record->addDecl(D: NewFD);
18322
18323 return NewFD;
18324}
18325
18326FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T,
18327 TypeSourceInfo *TInfo,
18328 RecordDecl *Record, SourceLocation Loc,
18329 bool Mutable, Expr *BitWidth,
18330 InClassInitStyle InitStyle,
18331 SourceLocation TSSL,
18332 AccessSpecifier AS, NamedDecl *PrevDecl,
18333 Declarator *D) {
18334 const IdentifierInfo *II = Name.getAsIdentifierInfo();
18335 bool InvalidDecl = false;
18336 if (D) InvalidDecl = D->isInvalidType();
18337
18338 // If we receive a broken type, recover by assuming 'int' and
18339 // marking this declaration as invalid.
18340 if (T.isNull() || T->containsErrors()) {
18341 InvalidDecl = true;
18342 T = Context.IntTy;
18343 }
18344
18345 QualType EltTy = Context.getBaseElementType(QT: T);
18346 if (!EltTy->isDependentType() && !EltTy->containsErrors()) {
18347 if (RequireCompleteSizedType(Loc, T: EltTy,
18348 DiagID: diag::err_field_incomplete_or_sizeless)) {
18349 // Fields of incomplete type force their record to be invalid.
18350 Record->setInvalidDecl();
18351 InvalidDecl = true;
18352 } else {
18353 NamedDecl *Def;
18354 EltTy->isIncompleteType(Def: &Def);
18355 if (Def && Def->isInvalidDecl()) {
18356 Record->setInvalidDecl();
18357 InvalidDecl = true;
18358 }
18359 }
18360 }
18361
18362 // TR 18037 does not allow fields to be declared with address space
18363 if (T.hasAddressSpace() || T->isDependentAddressSpaceType() ||
18364 T->getBaseElementTypeUnsafe()->isDependentAddressSpaceType()) {
18365 Diag(Loc, DiagID: diag::err_field_with_address_space);
18366 Record->setInvalidDecl();
18367 InvalidDecl = true;
18368 }
18369
18370 if (LangOpts.OpenCL) {
18371 // OpenCL v1.2 s6.9b,r & OpenCL v2.0 s6.12.5 - The following types cannot be
18372 // used as structure or union field: image, sampler, event or block types.
18373 if (T->isEventT() || T->isImageType() || T->isSamplerT() ||
18374 T->isBlockPointerType()) {
18375 Diag(Loc, DiagID: diag::err_opencl_type_struct_or_union_field) << T;
18376 Record->setInvalidDecl();
18377 InvalidDecl = true;
18378 }
18379 // OpenCL v1.2 s6.9.c: bitfields are not supported, unless Clang extension
18380 // is enabled.
18381 if (BitWidth && !getOpenCLOptions().isAvailableOption(
18382 Ext: "__cl_clang_bitfields", LO: LangOpts)) {
18383 Diag(Loc, DiagID: diag::err_opencl_bitfields);
18384 InvalidDecl = true;
18385 }
18386 }
18387
18388 // Anonymous bit-fields cannot be cv-qualified (CWG 2229).
18389 if (!InvalidDecl && getLangOpts().CPlusPlus && !II && BitWidth &&
18390 T.hasQualifiers()) {
18391 InvalidDecl = true;
18392 Diag(Loc, DiagID: diag::err_anon_bitfield_qualifiers);
18393 }
18394
18395 // C99 6.7.2.1p8: A member of a structure or union may have any type other
18396 // than a variably modified type.
18397 if (!InvalidDecl && T->isVariablyModifiedType()) {
18398 if (!tryToFixVariablyModifiedVarType(
18399 TInfo, T, Loc, FailedFoldDiagID: diag::err_typecheck_field_variable_size))
18400 InvalidDecl = true;
18401 }
18402
18403 // Fields can not have abstract class types
18404 if (!InvalidDecl && RequireNonAbstractType(Loc, T,
18405 DiagID: diag::err_abstract_type_in_decl,
18406 Args: AbstractFieldType))
18407 InvalidDecl = true;
18408
18409 if (InvalidDecl)
18410 BitWidth = nullptr;
18411 // If this is declared as a bit-field, check the bit-field.
18412 if (BitWidth) {
18413 BitWidth =
18414 VerifyBitField(FieldLoc: Loc, FieldName: II, FieldTy: T, IsMsStruct: Record->isMsStruct(C: Context), BitWidth).get();
18415 if (!BitWidth) {
18416 InvalidDecl = true;
18417 BitWidth = nullptr;
18418 }
18419 }
18420
18421 // Check that 'mutable' is consistent with the type of the declaration.
18422 if (!InvalidDecl && Mutable) {
18423 unsigned DiagID = 0;
18424 if (T->isReferenceType())
18425 DiagID = getLangOpts().MSVCCompat ? diag::ext_mutable_reference
18426 : diag::err_mutable_reference;
18427 else if (T.isConstQualified())
18428 DiagID = diag::err_mutable_const;
18429
18430 if (DiagID) {
18431 SourceLocation ErrLoc = Loc;
18432 if (D && D->getDeclSpec().getStorageClassSpecLoc().isValid())
18433 ErrLoc = D->getDeclSpec().getStorageClassSpecLoc();
18434 Diag(Loc: ErrLoc, DiagID);
18435 if (DiagID != diag::ext_mutable_reference) {
18436 Mutable = false;
18437 InvalidDecl = true;
18438 }
18439 }
18440 }
18441
18442 // C++11 [class.union]p8 (DR1460):
18443 // At most one variant member of a union may have a
18444 // brace-or-equal-initializer.
18445 if (InitStyle != ICIS_NoInit)
18446 checkDuplicateDefaultInit(S&: *this, Parent: cast<CXXRecordDecl>(Val: Record), DefaultInitLoc: Loc);
18447
18448 FieldDecl *NewFD = FieldDecl::Create(C: Context, DC: Record, StartLoc: TSSL, IdLoc: Loc, Id: II, T, TInfo,
18449 BW: BitWidth, Mutable, InitStyle);
18450 if (InvalidDecl)
18451 NewFD->setInvalidDecl();
18452
18453 if (PrevDecl && !isa<TagDecl>(Val: PrevDecl) &&
18454 !PrevDecl->isPlaceholderVar(LangOpts: getLangOpts())) {
18455 Diag(Loc, DiagID: diag::err_duplicate_member) << II;
18456 Diag(Loc: PrevDecl->getLocation(), DiagID: diag::note_previous_declaration);
18457 NewFD->setInvalidDecl();
18458 }
18459
18460 if (!InvalidDecl && getLangOpts().CPlusPlus) {
18461 if (Record->isUnion()) {
18462 if (const RecordType *RT = EltTy->getAs<RecordType>()) {
18463 CXXRecordDecl* RDecl = cast<CXXRecordDecl>(Val: RT->getDecl());
18464 if (RDecl->getDefinition()) {
18465 // C++ [class.union]p1: An object of a class with a non-trivial
18466 // constructor, a non-trivial copy constructor, a non-trivial
18467 // destructor, or a non-trivial copy assignment operator
18468 // cannot be a member of a union, nor can an array of such
18469 // objects.
18470 if (CheckNontrivialField(FD: NewFD))
18471 NewFD->setInvalidDecl();
18472 }
18473 }
18474
18475 // C++ [class.union]p1: If a union contains a member of reference type,
18476 // the program is ill-formed, except when compiling with MSVC extensions
18477 // enabled.
18478 if (EltTy->isReferenceType()) {
18479 Diag(Loc: NewFD->getLocation(), DiagID: getLangOpts().MicrosoftExt ?
18480 diag::ext_union_member_of_reference_type :
18481 diag::err_union_member_of_reference_type)
18482 << NewFD->getDeclName() << EltTy;
18483 if (!getLangOpts().MicrosoftExt)
18484 NewFD->setInvalidDecl();
18485 }
18486 }
18487 }
18488
18489 // FIXME: We need to pass in the attributes given an AST
18490 // representation, not a parser representation.
18491 if (D) {
18492 // FIXME: The current scope is almost... but not entirely... correct here.
18493 ProcessDeclAttributes(S: getCurScope(), D: NewFD, PD: *D);
18494
18495 if (NewFD->hasAttrs())
18496 CheckAlignasUnderalignment(D: NewFD);
18497 }
18498
18499 // In auto-retain/release, infer strong retension for fields of
18500 // retainable type.
18501 if (getLangOpts().ObjCAutoRefCount && ObjC().inferObjCARCLifetime(decl: NewFD))
18502 NewFD->setInvalidDecl();
18503
18504 if (T.isObjCGCWeak())
18505 Diag(Loc, DiagID: diag::warn_attribute_weak_on_field);
18506
18507 // PPC MMA non-pointer types are not allowed as field types.
18508 if (Context.getTargetInfo().getTriple().isPPC64() &&
18509 PPC().CheckPPCMMAType(Type: T, TypeLoc: NewFD->getLocation()))
18510 NewFD->setInvalidDecl();
18511
18512 NewFD->setAccess(AS);
18513 return NewFD;
18514}
18515
18516bool Sema::CheckNontrivialField(FieldDecl *FD) {
18517 assert(FD);
18518 assert(getLangOpts().CPlusPlus && "valid check only for C++");
18519
18520 if (FD->isInvalidDecl() || FD->getType()->isDependentType())
18521 return false;
18522
18523 QualType EltTy = Context.getBaseElementType(QT: FD->getType());
18524 if (const RecordType *RT = EltTy->getAs<RecordType>()) {
18525 CXXRecordDecl *RDecl = cast<CXXRecordDecl>(Val: RT->getDecl());
18526 if (RDecl->getDefinition()) {
18527 // We check for copy constructors before constructors
18528 // because otherwise we'll never get complaints about
18529 // copy constructors.
18530
18531 CXXSpecialMemberKind member = CXXSpecialMemberKind::Invalid;
18532 // We're required to check for any non-trivial constructors. Since the
18533 // implicit default constructor is suppressed if there are any
18534 // user-declared constructors, we just need to check that there is a
18535 // trivial default constructor and a trivial copy constructor. (We don't
18536 // worry about move constructors here, since this is a C++98 check.)
18537 if (RDecl->hasNonTrivialCopyConstructor())
18538 member = CXXSpecialMemberKind::CopyConstructor;
18539 else if (!RDecl->hasTrivialDefaultConstructor())
18540 member = CXXSpecialMemberKind::DefaultConstructor;
18541 else if (RDecl->hasNonTrivialCopyAssignment())
18542 member = CXXSpecialMemberKind::CopyAssignment;
18543 else if (RDecl->hasNonTrivialDestructor())
18544 member = CXXSpecialMemberKind::Destructor;
18545
18546 if (member != CXXSpecialMemberKind::Invalid) {
18547 if (!getLangOpts().CPlusPlus11 &&
18548 getLangOpts().ObjCAutoRefCount && RDecl->hasObjectMember()) {
18549 // Objective-C++ ARC: it is an error to have a non-trivial field of
18550 // a union. However, system headers in Objective-C programs
18551 // occasionally have Objective-C lifetime objects within unions,
18552 // and rather than cause the program to fail, we make those
18553 // members unavailable.
18554 SourceLocation Loc = FD->getLocation();
18555 if (getSourceManager().isInSystemHeader(Loc)) {
18556 if (!FD->hasAttr<UnavailableAttr>())
18557 FD->addAttr(A: UnavailableAttr::CreateImplicit(Ctx&: Context, Message: "",
18558 ImplicitReason: UnavailableAttr::IR_ARCFieldWithOwnership, Range: Loc));
18559 return false;
18560 }
18561 }
18562
18563 Diag(
18564 Loc: FD->getLocation(),
18565 DiagID: getLangOpts().CPlusPlus11
18566 ? diag::warn_cxx98_compat_nontrivial_union_or_anon_struct_member
18567 : diag::err_illegal_union_or_anon_struct_member)
18568 << FD->getParent()->isUnion() << FD->getDeclName()
18569 << llvm::to_underlying(E: member);
18570 DiagnoseNontrivial(Record: RDecl, CSM: member);
18571 return !getLangOpts().CPlusPlus11;
18572 }
18573 }
18574 }
18575
18576 return false;
18577}
18578
18579void Sema::ActOnLastBitfield(SourceLocation DeclLoc,
18580 SmallVectorImpl<Decl *> &AllIvarDecls) {
18581 if (LangOpts.ObjCRuntime.isFragile() || AllIvarDecls.empty())
18582 return;
18583
18584 Decl *ivarDecl = AllIvarDecls[AllIvarDecls.size()-1];
18585 ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(Val: ivarDecl);
18586
18587 if (!Ivar->isBitField() || Ivar->isZeroLengthBitField(Ctx: Context))
18588 return;
18589 ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(Val: CurContext);
18590 if (!ID) {
18591 if (ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(Val: CurContext)) {
18592 if (!CD->IsClassExtension())
18593 return;
18594 }
18595 // No need to add this to end of @implementation.
18596 else
18597 return;
18598 }
18599 // All conditions are met. Add a new bitfield to the tail end of ivars.
18600 llvm::APInt Zero(Context.getTypeSize(T: Context.IntTy), 0);
18601 Expr * BW = IntegerLiteral::Create(C: Context, V: Zero, type: Context.IntTy, l: DeclLoc);
18602
18603 Ivar = ObjCIvarDecl::Create(C&: Context, DC: cast<ObjCContainerDecl>(Val: CurContext),
18604 StartLoc: DeclLoc, IdLoc: DeclLoc, Id: nullptr,
18605 T: Context.CharTy,
18606 TInfo: Context.getTrivialTypeSourceInfo(T: Context.CharTy,
18607 Loc: DeclLoc),
18608 ac: ObjCIvarDecl::Private, BW,
18609 synthesized: true);
18610 AllIvarDecls.push_back(Elt: Ivar);
18611}
18612
18613/// [class.dtor]p4:
18614/// At the end of the definition of a class, overload resolution is
18615/// performed among the prospective destructors declared in that class with
18616/// an empty argument list to select the destructor for the class, also
18617/// known as the selected destructor.
18618///
18619/// We do the overload resolution here, then mark the selected constructor in the AST.
18620/// Later CXXRecordDecl::getDestructor() will return the selected constructor.
18621static void ComputeSelectedDestructor(Sema &S, CXXRecordDecl *Record) {
18622 if (!Record->hasUserDeclaredDestructor()) {
18623 return;
18624 }
18625
18626 SourceLocation Loc = Record->getLocation();
18627 OverloadCandidateSet OCS(Loc, OverloadCandidateSet::CSK_Normal);
18628
18629 for (auto *Decl : Record->decls()) {
18630 if (auto *DD = dyn_cast<CXXDestructorDecl>(Val: Decl)) {
18631 if (DD->isInvalidDecl())
18632 continue;
18633 S.AddOverloadCandidate(Function: DD, FoundDecl: DeclAccessPair::make(D: DD, AS: DD->getAccess()), Args: {},
18634 CandidateSet&: OCS);
18635 assert(DD->isIneligibleOrNotSelected() && "Selecting a destructor but a destructor was already selected.");
18636 }
18637 }
18638
18639 if (OCS.empty()) {
18640 return;
18641 }
18642 OverloadCandidateSet::iterator Best;
18643 unsigned Msg = 0;
18644 OverloadCandidateDisplayKind DisplayKind;
18645
18646 switch (OCS.BestViableFunction(S, Loc, Best)) {
18647 case OR_Success:
18648 case OR_Deleted:
18649 Record->addedSelectedDestructor(DD: dyn_cast<CXXDestructorDecl>(Val: Best->Function));
18650 break;
18651
18652 case OR_Ambiguous:
18653 Msg = diag::err_ambiguous_destructor;
18654 DisplayKind = OCD_AmbiguousCandidates;
18655 break;
18656
18657 case OR_No_Viable_Function:
18658 Msg = diag::err_no_viable_destructor;
18659 DisplayKind = OCD_AllCandidates;
18660 break;
18661 }
18662
18663 if (Msg) {
18664 // OpenCL have got their own thing going with destructors. It's slightly broken,
18665 // but we allow it.
18666 if (!S.LangOpts.OpenCL) {
18667 PartialDiagnostic Diag = S.PDiag(DiagID: Msg) << Record;
18668 OCS.NoteCandidates(PA: PartialDiagnosticAt(Loc, Diag), S, OCD: DisplayKind, Args: {});
18669 Record->setInvalidDecl();
18670 }
18671 // It's a bit hacky: At this point we've raised an error but we want the
18672 // rest of the compiler to continue somehow working. However almost
18673 // everything we'll try to do with the class will depend on there being a
18674 // destructor. So let's pretend the first one is selected and hope for the
18675 // best.
18676 Record->addedSelectedDestructor(DD: dyn_cast<CXXDestructorDecl>(Val: OCS.begin()->Function));
18677 }
18678}
18679
18680/// [class.mem.special]p5
18681/// Two special member functions are of the same kind if:
18682/// - they are both default constructors,
18683/// - they are both copy or move constructors with the same first parameter
18684/// type, or
18685/// - they are both copy or move assignment operators with the same first
18686/// parameter type and the same cv-qualifiers and ref-qualifier, if any.
18687static bool AreSpecialMemberFunctionsSameKind(ASTContext &Context,
18688 CXXMethodDecl *M1,
18689 CXXMethodDecl *M2,
18690 CXXSpecialMemberKind CSM) {
18691 // We don't want to compare templates to non-templates: See
18692 // https://github.com/llvm/llvm-project/issues/59206
18693 if (CSM == CXXSpecialMemberKind::DefaultConstructor)
18694 return bool(M1->getDescribedFunctionTemplate()) ==
18695 bool(M2->getDescribedFunctionTemplate());
18696 // FIXME: better resolve CWG
18697 // https://cplusplus.github.io/CWG/issues/2787.html
18698 if (!Context.hasSameType(T1: M1->getNonObjectParameter(I: 0)->getType(),
18699 T2: M2->getNonObjectParameter(I: 0)->getType()))
18700 return false;
18701 if (!Context.hasSameType(T1: M1->getFunctionObjectParameterReferenceType(),
18702 T2: M2->getFunctionObjectParameterReferenceType()))
18703 return false;
18704
18705 return true;
18706}
18707
18708/// [class.mem.special]p6:
18709/// An eligible special member function is a special member function for which:
18710/// - the function is not deleted,
18711/// - the associated constraints, if any, are satisfied, and
18712/// - no special member function of the same kind whose associated constraints
18713/// [CWG2595], if any, are satisfied is more constrained.
18714static void SetEligibleMethods(Sema &S, CXXRecordDecl *Record,
18715 ArrayRef<CXXMethodDecl *> Methods,
18716 CXXSpecialMemberKind CSM) {
18717 SmallVector<bool, 4> SatisfactionStatus;
18718
18719 for (CXXMethodDecl *Method : Methods) {
18720 const Expr *Constraints = Method->getTrailingRequiresClause();
18721 if (!Constraints)
18722 SatisfactionStatus.push_back(Elt: true);
18723 else {
18724 ConstraintSatisfaction Satisfaction;
18725 if (S.CheckFunctionConstraints(FD: Method, Satisfaction))
18726 SatisfactionStatus.push_back(Elt: false);
18727 else
18728 SatisfactionStatus.push_back(Elt: Satisfaction.IsSatisfied);
18729 }
18730 }
18731
18732 for (size_t i = 0; i < Methods.size(); i++) {
18733 if (!SatisfactionStatus[i])
18734 continue;
18735 CXXMethodDecl *Method = Methods[i];
18736 CXXMethodDecl *OrigMethod = Method;
18737 if (FunctionDecl *MF = OrigMethod->getInstantiatedFromMemberFunction())
18738 OrigMethod = cast<CXXMethodDecl>(Val: MF);
18739
18740 const Expr *Constraints = OrigMethod->getTrailingRequiresClause();
18741 bool AnotherMethodIsMoreConstrained = false;
18742 for (size_t j = 0; j < Methods.size(); j++) {
18743 if (i == j || !SatisfactionStatus[j])
18744 continue;
18745 CXXMethodDecl *OtherMethod = Methods[j];
18746 if (FunctionDecl *MF = OtherMethod->getInstantiatedFromMemberFunction())
18747 OtherMethod = cast<CXXMethodDecl>(Val: MF);
18748
18749 if (!AreSpecialMemberFunctionsSameKind(Context&: S.Context, M1: OrigMethod, M2: OtherMethod,
18750 CSM))
18751 continue;
18752
18753 const Expr *OtherConstraints = OtherMethod->getTrailingRequiresClause();
18754 if (!OtherConstraints)
18755 continue;
18756 if (!Constraints) {
18757 AnotherMethodIsMoreConstrained = true;
18758 break;
18759 }
18760 if (S.IsAtLeastAsConstrained(D1: OtherMethod, AC1: {OtherConstraints}, D2: OrigMethod,
18761 AC2: {Constraints},
18762 Result&: AnotherMethodIsMoreConstrained)) {
18763 // There was an error with the constraints comparison. Exit the loop
18764 // and don't consider this function eligible.
18765 AnotherMethodIsMoreConstrained = true;
18766 }
18767 if (AnotherMethodIsMoreConstrained)
18768 break;
18769 }
18770 // FIXME: Do not consider deleted methods as eligible after implementing
18771 // DR1734 and DR1496.
18772 if (!AnotherMethodIsMoreConstrained) {
18773 Method->setIneligibleOrNotSelected(false);
18774 Record->addedEligibleSpecialMemberFunction(MD: Method,
18775 SMKind: 1 << llvm::to_underlying(E: CSM));
18776 }
18777 }
18778}
18779
18780static void ComputeSpecialMemberFunctionsEligiblity(Sema &S,
18781 CXXRecordDecl *Record) {
18782 SmallVector<CXXMethodDecl *, 4> DefaultConstructors;
18783 SmallVector<CXXMethodDecl *, 4> CopyConstructors;
18784 SmallVector<CXXMethodDecl *, 4> MoveConstructors;
18785 SmallVector<CXXMethodDecl *, 4> CopyAssignmentOperators;
18786 SmallVector<CXXMethodDecl *, 4> MoveAssignmentOperators;
18787
18788 for (auto *Decl : Record->decls()) {
18789 auto *MD = dyn_cast<CXXMethodDecl>(Val: Decl);
18790 if (!MD) {
18791 auto *FTD = dyn_cast<FunctionTemplateDecl>(Val: Decl);
18792 if (FTD)
18793 MD = dyn_cast<CXXMethodDecl>(Val: FTD->getTemplatedDecl());
18794 }
18795 if (!MD)
18796 continue;
18797 if (auto *CD = dyn_cast<CXXConstructorDecl>(Val: MD)) {
18798 if (CD->isInvalidDecl())
18799 continue;
18800 if (CD->isDefaultConstructor())
18801 DefaultConstructors.push_back(Elt: MD);
18802 else if (CD->isCopyConstructor())
18803 CopyConstructors.push_back(Elt: MD);
18804 else if (CD->isMoveConstructor())
18805 MoveConstructors.push_back(Elt: MD);
18806 } else if (MD->isCopyAssignmentOperator()) {
18807 CopyAssignmentOperators.push_back(Elt: MD);
18808 } else if (MD->isMoveAssignmentOperator()) {
18809 MoveAssignmentOperators.push_back(Elt: MD);
18810 }
18811 }
18812
18813 SetEligibleMethods(S, Record, Methods: DefaultConstructors,
18814 CSM: CXXSpecialMemberKind::DefaultConstructor);
18815 SetEligibleMethods(S, Record, Methods: CopyConstructors,
18816 CSM: CXXSpecialMemberKind::CopyConstructor);
18817 SetEligibleMethods(S, Record, Methods: MoveConstructors,
18818 CSM: CXXSpecialMemberKind::MoveConstructor);
18819 SetEligibleMethods(S, Record, Methods: CopyAssignmentOperators,
18820 CSM: CXXSpecialMemberKind::CopyAssignment);
18821 SetEligibleMethods(S, Record, Methods: MoveAssignmentOperators,
18822 CSM: CXXSpecialMemberKind::MoveAssignment);
18823}
18824
18825void Sema::ActOnFields(Scope *S, SourceLocation RecLoc, Decl *EnclosingDecl,
18826 ArrayRef<Decl *> Fields, SourceLocation LBrac,
18827 SourceLocation RBrac,
18828 const ParsedAttributesView &Attrs) {
18829 assert(EnclosingDecl && "missing record or interface decl");
18830
18831 // If this is an Objective-C @implementation or category and we have
18832 // new fields here we should reset the layout of the interface since
18833 // it will now change.
18834 if (!Fields.empty() && isa<ObjCContainerDecl>(Val: EnclosingDecl)) {
18835 ObjCContainerDecl *DC = cast<ObjCContainerDecl>(Val: EnclosingDecl);
18836 switch (DC->getKind()) {
18837 default: break;
18838 case Decl::ObjCCategory:
18839 Context.ResetObjCLayout(CD: cast<ObjCCategoryDecl>(Val: DC)->getClassInterface());
18840 break;
18841 case Decl::ObjCImplementation:
18842 Context.
18843 ResetObjCLayout(CD: cast<ObjCImplementationDecl>(Val: DC)->getClassInterface());
18844 break;
18845 }
18846 }
18847
18848 RecordDecl *Record = dyn_cast<RecordDecl>(Val: EnclosingDecl);
18849 CXXRecordDecl *CXXRecord = dyn_cast<CXXRecordDecl>(Val: EnclosingDecl);
18850
18851 // Start counting up the number of named members; make sure to include
18852 // members of anonymous structs and unions in the total.
18853 unsigned NumNamedMembers = 0;
18854 if (Record) {
18855 for (const auto *I : Record->decls()) {
18856 if (const auto *IFD = dyn_cast<IndirectFieldDecl>(Val: I))
18857 if (IFD->getDeclName())
18858 ++NumNamedMembers;
18859 }
18860 }
18861
18862 // Verify that all the fields are okay.
18863 SmallVector<FieldDecl*, 32> RecFields;
18864
18865 for (ArrayRef<Decl *>::iterator i = Fields.begin(), end = Fields.end();
18866 i != end; ++i) {
18867 FieldDecl *FD = cast<FieldDecl>(Val: *i);
18868
18869 // Get the type for the field.
18870 const Type *FDTy = FD->getType().getTypePtr();
18871
18872 if (!FD->isAnonymousStructOrUnion()) {
18873 // Remember all fields written by the user.
18874 RecFields.push_back(Elt: FD);
18875 }
18876
18877 // If the field is already invalid for some reason, don't emit more
18878 // diagnostics about it.
18879 if (FD->isInvalidDecl()) {
18880 EnclosingDecl->setInvalidDecl();
18881 continue;
18882 }
18883
18884 // C99 6.7.2.1p2:
18885 // A structure or union shall not contain a member with
18886 // incomplete or function type (hence, a structure shall not
18887 // contain an instance of itself, but may contain a pointer to
18888 // an instance of itself), except that the last member of a
18889 // structure with more than one named member may have incomplete
18890 // array type; such a structure (and any union containing,
18891 // possibly recursively, a member that is such a structure)
18892 // shall not be a member of a structure or an element of an
18893 // array.
18894 bool IsLastField = (i + 1 == Fields.end());
18895 if (FDTy->isFunctionType()) {
18896 // Field declared as a function.
18897 Diag(Loc: FD->getLocation(), DiagID: diag::err_field_declared_as_function)
18898 << FD->getDeclName();
18899 FD->setInvalidDecl();
18900 EnclosingDecl->setInvalidDecl();
18901 continue;
18902 } else if (FDTy->isIncompleteArrayType() &&
18903 (Record || isa<ObjCContainerDecl>(Val: EnclosingDecl))) {
18904 if (Record) {
18905 // Flexible array member.
18906 // Microsoft and g++ is more permissive regarding flexible array.
18907 // It will accept flexible array in union and also
18908 // as the sole element of a struct/class.
18909 unsigned DiagID = 0;
18910 if (!Record->isUnion() && !IsLastField) {
18911 Diag(Loc: FD->getLocation(), DiagID: diag::err_flexible_array_not_at_end)
18912 << FD->getDeclName() << FD->getType()
18913 << llvm::to_underlying(E: Record->getTagKind());
18914 Diag(Loc: (*(i + 1))->getLocation(), DiagID: diag::note_next_field_declaration);
18915 FD->setInvalidDecl();
18916 EnclosingDecl->setInvalidDecl();
18917 continue;
18918 } else if (Record->isUnion())
18919 DiagID = getLangOpts().MicrosoftExt
18920 ? diag::ext_flexible_array_union_ms
18921 : diag::ext_flexible_array_union_gnu;
18922 else if (NumNamedMembers < 1)
18923 DiagID = getLangOpts().MicrosoftExt
18924 ? diag::ext_flexible_array_empty_aggregate_ms
18925 : diag::ext_flexible_array_empty_aggregate_gnu;
18926
18927 if (DiagID)
18928 Diag(Loc: FD->getLocation(), DiagID)
18929 << FD->getDeclName() << llvm::to_underlying(E: Record->getTagKind());
18930 // While the layout of types that contain virtual bases is not specified
18931 // by the C++ standard, both the Itanium and Microsoft C++ ABIs place
18932 // virtual bases after the derived members. This would make a flexible
18933 // array member declared at the end of an object not adjacent to the end
18934 // of the type.
18935 if (CXXRecord && CXXRecord->getNumVBases() != 0)
18936 Diag(Loc: FD->getLocation(), DiagID: diag::err_flexible_array_virtual_base)
18937 << FD->getDeclName() << llvm::to_underlying(E: Record->getTagKind());
18938 if (!getLangOpts().C99)
18939 Diag(Loc: FD->getLocation(), DiagID: diag::ext_c99_flexible_array_member)
18940 << FD->getDeclName() << llvm::to_underlying(E: Record->getTagKind());
18941
18942 // If the element type has a non-trivial destructor, we would not
18943 // implicitly destroy the elements, so disallow it for now.
18944 //
18945 // FIXME: GCC allows this. We should probably either implicitly delete
18946 // the destructor of the containing class, or just allow this.
18947 QualType BaseElem = Context.getBaseElementType(QT: FD->getType());
18948 if (!BaseElem->isDependentType() && BaseElem.isDestructedType()) {
18949 Diag(Loc: FD->getLocation(), DiagID: diag::err_flexible_array_has_nontrivial_dtor)
18950 << FD->getDeclName() << FD->getType();
18951 FD->setInvalidDecl();
18952 EnclosingDecl->setInvalidDecl();
18953 continue;
18954 }
18955 // Okay, we have a legal flexible array member at the end of the struct.
18956 Record->setHasFlexibleArrayMember(true);
18957 } else {
18958 // In ObjCContainerDecl ivars with incomplete array type are accepted,
18959 // unless they are followed by another ivar. That check is done
18960 // elsewhere, after synthesized ivars are known.
18961 }
18962 } else if (!FDTy->isDependentType() &&
18963 RequireCompleteSizedType(
18964 Loc: FD->getLocation(), T: FD->getType(),
18965 DiagID: diag::err_field_incomplete_or_sizeless)) {
18966 // Incomplete type
18967 FD->setInvalidDecl();
18968 EnclosingDecl->setInvalidDecl();
18969 continue;
18970 } else if (const RecordType *FDTTy = FDTy->getAs<RecordType>()) {
18971 if (Record && FDTTy->getDecl()->hasFlexibleArrayMember()) {
18972 // A type which contains a flexible array member is considered to be a
18973 // flexible array member.
18974 Record->setHasFlexibleArrayMember(true);
18975 if (!Record->isUnion()) {
18976 // If this is a struct/class and this is not the last element, reject
18977 // it. Note that GCC supports variable sized arrays in the middle of
18978 // structures.
18979 if (!IsLastField)
18980 Diag(Loc: FD->getLocation(), DiagID: diag::ext_variable_sized_type_in_struct)
18981 << FD->getDeclName() << FD->getType();
18982 else {
18983 // We support flexible arrays at the end of structs in
18984 // other structs as an extension.
18985 Diag(Loc: FD->getLocation(), DiagID: diag::ext_flexible_array_in_struct)
18986 << FD->getDeclName();
18987 }
18988 }
18989 }
18990 if (isa<ObjCContainerDecl>(Val: EnclosingDecl) &&
18991 RequireNonAbstractType(Loc: FD->getLocation(), T: FD->getType(),
18992 DiagID: diag::err_abstract_type_in_decl,
18993 Args: AbstractIvarType)) {
18994 // Ivars can not have abstract class types
18995 FD->setInvalidDecl();
18996 }
18997 if (Record && FDTTy->getDecl()->hasObjectMember())
18998 Record->setHasObjectMember(true);
18999 if (Record && FDTTy->getDecl()->hasVolatileMember())
19000 Record->setHasVolatileMember(true);
19001 } else if (FDTy->isObjCObjectType()) {
19002 /// A field cannot be an Objective-c object
19003 Diag(Loc: FD->getLocation(), DiagID: diag::err_statically_allocated_object)
19004 << FixItHint::CreateInsertion(InsertionLoc: FD->getLocation(), Code: "*");
19005 QualType T = Context.getObjCObjectPointerType(OIT: FD->getType());
19006 FD->setType(T);
19007 } else if (Record && Record->isUnion() &&
19008 FD->getType().hasNonTrivialObjCLifetime() &&
19009 getSourceManager().isInSystemHeader(Loc: FD->getLocation()) &&
19010 !getLangOpts().CPlusPlus && !FD->hasAttr<UnavailableAttr>() &&
19011 (FD->getType().getObjCLifetime() != Qualifiers::OCL_Strong ||
19012 !Context.hasDirectOwnershipQualifier(Ty: FD->getType()))) {
19013 // For backward compatibility, fields of C unions declared in system
19014 // headers that have non-trivial ObjC ownership qualifications are marked
19015 // as unavailable unless the qualifier is explicit and __strong. This can
19016 // break ABI compatibility between programs compiled with ARC and MRR, but
19017 // is a better option than rejecting programs using those unions under
19018 // ARC.
19019 FD->addAttr(A: UnavailableAttr::CreateImplicit(
19020 Ctx&: Context, Message: "", ImplicitReason: UnavailableAttr::IR_ARCFieldWithOwnership,
19021 Range: FD->getLocation()));
19022 } else if (getLangOpts().ObjC &&
19023 getLangOpts().getGC() != LangOptions::NonGC && Record &&
19024 !Record->hasObjectMember()) {
19025 if (FD->getType()->isObjCObjectPointerType() ||
19026 FD->getType().isObjCGCStrong())
19027 Record->setHasObjectMember(true);
19028 else if (Context.getAsArrayType(T: FD->getType())) {
19029 QualType BaseType = Context.getBaseElementType(QT: FD->getType());
19030 if (BaseType->isRecordType() &&
19031 BaseType->castAs<RecordType>()->getDecl()->hasObjectMember())
19032 Record->setHasObjectMember(true);
19033 else if (BaseType->isObjCObjectPointerType() ||
19034 BaseType.isObjCGCStrong())
19035 Record->setHasObjectMember(true);
19036 }
19037 }
19038
19039 if (Record && !getLangOpts().CPlusPlus &&
19040 !shouldIgnoreForRecordTriviality(FD)) {
19041 QualType FT = FD->getType();
19042 if (FT.isNonTrivialToPrimitiveDefaultInitialize()) {
19043 Record->setNonTrivialToPrimitiveDefaultInitialize(true);
19044 if (FT.hasNonTrivialToPrimitiveDefaultInitializeCUnion() ||
19045 Record->isUnion())
19046 Record->setHasNonTrivialToPrimitiveDefaultInitializeCUnion(true);
19047 }
19048 QualType::PrimitiveCopyKind PCK = FT.isNonTrivialToPrimitiveCopy();
19049 if (PCK != QualType::PCK_Trivial && PCK != QualType::PCK_VolatileTrivial) {
19050 Record->setNonTrivialToPrimitiveCopy(true);
19051 if (FT.hasNonTrivialToPrimitiveCopyCUnion() || Record->isUnion())
19052 Record->setHasNonTrivialToPrimitiveCopyCUnion(true);
19053 }
19054 if (FT.isDestructedType()) {
19055 Record->setNonTrivialToPrimitiveDestroy(true);
19056 Record->setParamDestroyedInCallee(true);
19057 if (FT.hasNonTrivialToPrimitiveDestructCUnion() || Record->isUnion())
19058 Record->setHasNonTrivialToPrimitiveDestructCUnion(true);
19059 }
19060
19061 if (const auto *RT = FT->getAs<RecordType>()) {
19062 if (RT->getDecl()->getArgPassingRestrictions() ==
19063 RecordArgPassingKind::CanNeverPassInRegs)
19064 Record->setArgPassingRestrictions(
19065 RecordArgPassingKind::CanNeverPassInRegs);
19066 } else if (FT.getQualifiers().getObjCLifetime() == Qualifiers::OCL_Weak)
19067 Record->setArgPassingRestrictions(
19068 RecordArgPassingKind::CanNeverPassInRegs);
19069 }
19070
19071 if (Record && FD->getType().isVolatileQualified())
19072 Record->setHasVolatileMember(true);
19073 // Keep track of the number of named members.
19074 if (FD->getIdentifier())
19075 ++NumNamedMembers;
19076 }
19077
19078 // Okay, we successfully defined 'Record'.
19079 if (Record) {
19080 bool Completed = false;
19081 if (S) {
19082 Scope *Parent = S->getParent();
19083 if (Parent && Parent->isTypeAliasScope() &&
19084 Parent->isTemplateParamScope())
19085 Record->setInvalidDecl();
19086 }
19087
19088 if (CXXRecord) {
19089 if (!CXXRecord->isInvalidDecl()) {
19090 // Set access bits correctly on the directly-declared conversions.
19091 for (CXXRecordDecl::conversion_iterator
19092 I = CXXRecord->conversion_begin(),
19093 E = CXXRecord->conversion_end(); I != E; ++I)
19094 I.setAccess((*I)->getAccess());
19095 }
19096
19097 // Add any implicitly-declared members to this class.
19098 AddImplicitlyDeclaredMembersToClass(ClassDecl: CXXRecord);
19099
19100 if (!CXXRecord->isDependentType()) {
19101 if (!CXXRecord->isInvalidDecl()) {
19102 // If we have virtual base classes, we may end up finding multiple
19103 // final overriders for a given virtual function. Check for this
19104 // problem now.
19105 if (CXXRecord->getNumVBases()) {
19106 CXXFinalOverriderMap FinalOverriders;
19107 CXXRecord->getFinalOverriders(FinaOverriders&: FinalOverriders);
19108
19109 for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
19110 MEnd = FinalOverriders.end();
19111 M != MEnd; ++M) {
19112 for (OverridingMethods::iterator SO = M->second.begin(),
19113 SOEnd = M->second.end();
19114 SO != SOEnd; ++SO) {
19115 assert(SO->second.size() > 0 &&
19116 "Virtual function without overriding functions?");
19117 if (SO->second.size() == 1)
19118 continue;
19119
19120 // C++ [class.virtual]p2:
19121 // In a derived class, if a virtual member function of a base
19122 // class subobject has more than one final overrider the
19123 // program is ill-formed.
19124 Diag(Loc: Record->getLocation(), DiagID: diag::err_multiple_final_overriders)
19125 << (const NamedDecl *)M->first << Record;
19126 Diag(Loc: M->first->getLocation(),
19127 DiagID: diag::note_overridden_virtual_function);
19128 for (OverridingMethods::overriding_iterator
19129 OM = SO->second.begin(),
19130 OMEnd = SO->second.end();
19131 OM != OMEnd; ++OM)
19132 Diag(Loc: OM->Method->getLocation(), DiagID: diag::note_final_overrider)
19133 << (const NamedDecl *)M->first << OM->Method->getParent();
19134
19135 Record->setInvalidDecl();
19136 }
19137 }
19138 CXXRecord->completeDefinition(FinalOverriders: &FinalOverriders);
19139 Completed = true;
19140 }
19141 }
19142 ComputeSelectedDestructor(S&: *this, Record: CXXRecord);
19143 ComputeSpecialMemberFunctionsEligiblity(S&: *this, Record: CXXRecord);
19144 }
19145 }
19146
19147 if (!Completed)
19148 Record->completeDefinition();
19149
19150 // Handle attributes before checking the layout.
19151 ProcessDeclAttributeList(S, D: Record, AttrList: Attrs);
19152
19153 // Check to see if a FieldDecl is a pointer to a function.
19154 auto IsFunctionPointerOrForwardDecl = [&](const Decl *D) {
19155 const FieldDecl *FD = dyn_cast<FieldDecl>(Val: D);
19156 if (!FD) {
19157 // Check whether this is a forward declaration that was inserted by
19158 // Clang. This happens when a non-forward declared / defined type is
19159 // used, e.g.:
19160 //
19161 // struct foo {
19162 // struct bar *(*f)();
19163 // struct bar *(*g)();
19164 // };
19165 //
19166 // "struct bar" shows up in the decl AST as a "RecordDecl" with an
19167 // incomplete definition.
19168 if (const auto *TD = dyn_cast<TagDecl>(Val: D))
19169 return !TD->isCompleteDefinition();
19170 return false;
19171 }
19172 QualType FieldType = FD->getType().getDesugaredType(Context);
19173 if (isa<PointerType>(Val: FieldType)) {
19174 QualType PointeeType = cast<PointerType>(Val&: FieldType)->getPointeeType();
19175 return PointeeType.getDesugaredType(Context)->isFunctionType();
19176 }
19177 return false;
19178 };
19179
19180 // Maybe randomize the record's decls. We automatically randomize a record
19181 // of function pointers, unless it has the "no_randomize_layout" attribute.
19182 if (!getLangOpts().CPlusPlus &&
19183 (Record->hasAttr<RandomizeLayoutAttr>() ||
19184 (!Record->hasAttr<NoRandomizeLayoutAttr>() &&
19185 llvm::all_of(Range: Record->decls(), P: IsFunctionPointerOrForwardDecl))) &&
19186 !Record->isUnion() && !getLangOpts().RandstructSeed.empty() &&
19187 !Record->isRandomized()) {
19188 SmallVector<Decl *, 32> NewDeclOrdering;
19189 if (randstruct::randomizeStructureLayout(Context, RD: Record,
19190 FinalOrdering&: NewDeclOrdering))
19191 Record->reorderDecls(Decls: NewDeclOrdering);
19192 }
19193
19194 // We may have deferred checking for a deleted destructor. Check now.
19195 if (CXXRecord) {
19196 auto *Dtor = CXXRecord->getDestructor();
19197 if (Dtor && Dtor->isImplicit() &&
19198 ShouldDeleteSpecialMember(MD: Dtor, CSM: CXXSpecialMemberKind::Destructor)) {
19199 CXXRecord->setImplicitDestructorIsDeleted();
19200 SetDeclDeleted(dcl: Dtor, DelLoc: CXXRecord->getLocation());
19201 }
19202 }
19203
19204 if (Record->hasAttrs()) {
19205 CheckAlignasUnderalignment(D: Record);
19206
19207 if (const MSInheritanceAttr *IA = Record->getAttr<MSInheritanceAttr>())
19208 checkMSInheritanceAttrOnDefinition(RD: cast<CXXRecordDecl>(Val: Record),
19209 Range: IA->getRange(), BestCase: IA->getBestCase(),
19210 SemanticSpelling: IA->getInheritanceModel());
19211 }
19212
19213 // Check if the structure/union declaration is a type that can have zero
19214 // size in C. For C this is a language extension, for C++ it may cause
19215 // compatibility problems.
19216 bool CheckForZeroSize;
19217 if (!getLangOpts().CPlusPlus) {
19218 CheckForZeroSize = true;
19219 } else {
19220 // For C++ filter out types that cannot be referenced in C code.
19221 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Val: Record);
19222 CheckForZeroSize =
19223 CXXRecord->getLexicalDeclContext()->isExternCContext() &&
19224 !CXXRecord->isDependentType() && !inTemplateInstantiation() &&
19225 CXXRecord->isCLike();
19226 }
19227 if (CheckForZeroSize) {
19228 bool ZeroSize = true;
19229 bool IsEmpty = true;
19230 unsigned NonBitFields = 0;
19231 for (RecordDecl::field_iterator I = Record->field_begin(),
19232 E = Record->field_end();
19233 (NonBitFields == 0 || ZeroSize) && I != E; ++I) {
19234 IsEmpty = false;
19235 if (I->isUnnamedBitField()) {
19236 if (!I->isZeroLengthBitField(Ctx: Context))
19237 ZeroSize = false;
19238 } else {
19239 ++NonBitFields;
19240 QualType FieldType = I->getType();
19241 if (FieldType->isIncompleteType() ||
19242 !Context.getTypeSizeInChars(T: FieldType).isZero())
19243 ZeroSize = false;
19244 }
19245 }
19246
19247 // Empty structs are an extension in C (C99 6.7.2.1p7). They are
19248 // allowed in C++, but warn if its declaration is inside
19249 // extern "C" block.
19250 if (ZeroSize) {
19251 Diag(Loc: RecLoc, DiagID: getLangOpts().CPlusPlus ?
19252 diag::warn_zero_size_struct_union_in_extern_c :
19253 diag::warn_zero_size_struct_union_compat)
19254 << IsEmpty << Record->isUnion() << (NonBitFields > 1);
19255 }
19256
19257 // Structs without named members are extension in C (C99 6.7.2.1p7),
19258 // but are accepted by GCC.
19259 if (NonBitFields == 0 && !getLangOpts().CPlusPlus) {
19260 Diag(Loc: RecLoc, DiagID: IsEmpty ? diag::ext_empty_struct_union :
19261 diag::ext_no_named_members_in_struct_union)
19262 << Record->isUnion();
19263 }
19264 }
19265 } else {
19266 ObjCIvarDecl **ClsFields =
19267 reinterpret_cast<ObjCIvarDecl**>(RecFields.data());
19268 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(Val: EnclosingDecl)) {
19269 ID->setEndOfDefinitionLoc(RBrac);
19270 // Add ivar's to class's DeclContext.
19271 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) {
19272 ClsFields[i]->setLexicalDeclContext(ID);
19273 ID->addDecl(D: ClsFields[i]);
19274 }
19275 // Must enforce the rule that ivars in the base classes may not be
19276 // duplicates.
19277 if (ID->getSuperClass())
19278 ObjC().DiagnoseDuplicateIvars(ID, SID: ID->getSuperClass());
19279 } else if (ObjCImplementationDecl *IMPDecl =
19280 dyn_cast<ObjCImplementationDecl>(Val: EnclosingDecl)) {
19281 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl");
19282 for (unsigned I = 0, N = RecFields.size(); I != N; ++I)
19283 // Ivar declared in @implementation never belongs to the implementation.
19284 // Only it is in implementation's lexical context.
19285 ClsFields[I]->setLexicalDeclContext(IMPDecl);
19286 ObjC().CheckImplementationIvars(ImpDecl: IMPDecl, Fields: ClsFields, nIvars: RecFields.size(),
19287 Loc: RBrac);
19288 IMPDecl->setIvarLBraceLoc(LBrac);
19289 IMPDecl->setIvarRBraceLoc(RBrac);
19290 } else if (ObjCCategoryDecl *CDecl =
19291 dyn_cast<ObjCCategoryDecl>(Val: EnclosingDecl)) {
19292 // case of ivars in class extension; all other cases have been
19293 // reported as errors elsewhere.
19294 // FIXME. Class extension does not have a LocEnd field.
19295 // CDecl->setLocEnd(RBrac);
19296 // Add ivar's to class extension's DeclContext.
19297 // Diagnose redeclaration of private ivars.
19298 ObjCInterfaceDecl *IDecl = CDecl->getClassInterface();
19299 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) {
19300 if (IDecl) {
19301 if (const ObjCIvarDecl *ClsIvar =
19302 IDecl->getIvarDecl(Id: ClsFields[i]->getIdentifier())) {
19303 Diag(Loc: ClsFields[i]->getLocation(),
19304 DiagID: diag::err_duplicate_ivar_declaration);
19305 Diag(Loc: ClsIvar->getLocation(), DiagID: diag::note_previous_definition);
19306 continue;
19307 }
19308 for (const auto *Ext : IDecl->known_extensions()) {
19309 if (const ObjCIvarDecl *ClsExtIvar
19310 = Ext->getIvarDecl(Id: ClsFields[i]->getIdentifier())) {
19311 Diag(Loc: ClsFields[i]->getLocation(),
19312 DiagID: diag::err_duplicate_ivar_declaration);
19313 Diag(Loc: ClsExtIvar->getLocation(), DiagID: diag::note_previous_definition);
19314 continue;
19315 }
19316 }
19317 }
19318 ClsFields[i]->setLexicalDeclContext(CDecl);
19319 CDecl->addDecl(D: ClsFields[i]);
19320 }
19321 CDecl->setIvarLBraceLoc(LBrac);
19322 CDecl->setIvarRBraceLoc(RBrac);
19323 }
19324 }
19325 ProcessAPINotes(D: Record);
19326}
19327
19328/// Determine whether the given integral value is representable within
19329/// the given type T.
19330static bool isRepresentableIntegerValue(ASTContext &Context,
19331 llvm::APSInt &Value,
19332 QualType T) {
19333 assert((T->isIntegralType(Context) || T->isEnumeralType()) &&
19334 "Integral type required!");
19335 unsigned BitWidth = Context.getIntWidth(T);
19336
19337 if (Value.isUnsigned() || Value.isNonNegative()) {
19338 if (T->isSignedIntegerOrEnumerationType())
19339 --BitWidth;
19340 return Value.getActiveBits() <= BitWidth;
19341 }
19342 return Value.getSignificantBits() <= BitWidth;
19343}
19344
19345// Given an integral type, return the next larger integral type
19346// (or a NULL type of no such type exists).
19347static QualType getNextLargerIntegralType(ASTContext &Context, QualType T) {
19348 // FIXME: Int128/UInt128 support, which also needs to be introduced into
19349 // enum checking below.
19350 assert((T->isIntegralType(Context) ||
19351 T->isEnumeralType()) && "Integral type required!");
19352 const unsigned NumTypes = 4;
19353 QualType SignedIntegralTypes[NumTypes] = {
19354 Context.ShortTy, Context.IntTy, Context.LongTy, Context.LongLongTy
19355 };
19356 QualType UnsignedIntegralTypes[NumTypes] = {
19357 Context.UnsignedShortTy, Context.UnsignedIntTy, Context.UnsignedLongTy,
19358 Context.UnsignedLongLongTy
19359 };
19360
19361 unsigned BitWidth = Context.getTypeSize(T);
19362 QualType *Types = T->isSignedIntegerOrEnumerationType()? SignedIntegralTypes
19363 : UnsignedIntegralTypes;
19364 for (unsigned I = 0; I != NumTypes; ++I)
19365 if (Context.getTypeSize(T: Types[I]) > BitWidth)
19366 return Types[I];
19367
19368 return QualType();
19369}
19370
19371EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum,
19372 EnumConstantDecl *LastEnumConst,
19373 SourceLocation IdLoc,
19374 IdentifierInfo *Id,
19375 Expr *Val) {
19376 unsigned IntWidth = Context.getTargetInfo().getIntWidth();
19377 llvm::APSInt EnumVal(IntWidth);
19378 QualType EltTy;
19379
19380 if (Val && DiagnoseUnexpandedParameterPack(E: Val, UPPC: UPPC_EnumeratorValue))
19381 Val = nullptr;
19382
19383 if (Val)
19384 Val = DefaultLvalueConversion(E: Val).get();
19385
19386 if (Val) {
19387 if (Enum->isDependentType() || Val->isTypeDependent() ||
19388 Val->containsErrors())
19389 EltTy = Context.DependentTy;
19390 else {
19391 // FIXME: We don't allow folding in C++11 mode for an enum with a fixed
19392 // underlying type, but do allow it in all other contexts.
19393 if (getLangOpts().CPlusPlus11 && Enum->isFixed()) {
19394 // C++11 [dcl.enum]p5: If the underlying type is fixed, [...] the
19395 // constant-expression in the enumerator-definition shall be a converted
19396 // constant expression of the underlying type.
19397 EltTy = Enum->getIntegerType();
19398 ExprResult Converted =
19399 CheckConvertedConstantExpression(From: Val, T: EltTy, Value&: EnumVal,
19400 CCE: CCEK_Enumerator);
19401 if (Converted.isInvalid())
19402 Val = nullptr;
19403 else
19404 Val = Converted.get();
19405 } else if (!Val->isValueDependent() &&
19406 !(Val =
19407 VerifyIntegerConstantExpression(E: Val, Result: &EnumVal, CanFold: AllowFold)
19408 .get())) {
19409 // C99 6.7.2.2p2: Make sure we have an integer constant expression.
19410 } else {
19411 if (Enum->isComplete()) {
19412 EltTy = Enum->getIntegerType();
19413
19414 // In Obj-C and Microsoft mode, require the enumeration value to be
19415 // representable in the underlying type of the enumeration. In C++11,
19416 // we perform a non-narrowing conversion as part of converted constant
19417 // expression checking.
19418 if (!isRepresentableIntegerValue(Context, Value&: EnumVal, T: EltTy)) {
19419 if (Context.getTargetInfo()
19420 .getTriple()
19421 .isWindowsMSVCEnvironment()) {
19422 Diag(Loc: IdLoc, DiagID: diag::ext_enumerator_too_large) << EltTy;
19423 } else {
19424 Diag(Loc: IdLoc, DiagID: diag::err_enumerator_too_large) << EltTy;
19425 }
19426 }
19427
19428 // Cast to the underlying type.
19429 Val = ImpCastExprToType(E: Val, Type: EltTy,
19430 CK: EltTy->isBooleanType() ? CK_IntegralToBoolean
19431 : CK_IntegralCast)
19432 .get();
19433 } else if (getLangOpts().CPlusPlus) {
19434 // C++11 [dcl.enum]p5:
19435 // If the underlying type is not fixed, the type of each enumerator
19436 // is the type of its initializing value:
19437 // - If an initializer is specified for an enumerator, the
19438 // initializing value has the same type as the expression.
19439 EltTy = Val->getType();
19440 } else {
19441 // C99 6.7.2.2p2:
19442 // The expression that defines the value of an enumeration constant
19443 // shall be an integer constant expression that has a value
19444 // representable as an int.
19445
19446 // Complain if the value is not representable in an int.
19447 if (!isRepresentableIntegerValue(Context, Value&: EnumVal, T: Context.IntTy))
19448 Diag(Loc: IdLoc, DiagID: diag::ext_enum_value_not_int)
19449 << toString(I: EnumVal, Radix: 10) << Val->getSourceRange()
19450 << (EnumVal.isUnsigned() || EnumVal.isNonNegative());
19451 else if (!Context.hasSameType(T1: Val->getType(), T2: Context.IntTy)) {
19452 // Force the type of the expression to 'int'.
19453 Val = ImpCastExprToType(E: Val, Type: Context.IntTy, CK: CK_IntegralCast).get();
19454 }
19455 EltTy = Val->getType();
19456 }
19457 }
19458 }
19459 }
19460
19461 if (!Val) {
19462 if (Enum->isDependentType())
19463 EltTy = Context.DependentTy;
19464 else if (!LastEnumConst) {
19465 // C++0x [dcl.enum]p5:
19466 // If the underlying type is not fixed, the type of each enumerator
19467 // is the type of its initializing value:
19468 // - If no initializer is specified for the first enumerator, the
19469 // initializing value has an unspecified integral type.
19470 //
19471 // GCC uses 'int' for its unspecified integral type, as does
19472 // C99 6.7.2.2p3.
19473 if (Enum->isFixed()) {
19474 EltTy = Enum->getIntegerType();
19475 }
19476 else {
19477 EltTy = Context.IntTy;
19478 }
19479 } else {
19480 // Assign the last value + 1.
19481 EnumVal = LastEnumConst->getInitVal();
19482 ++EnumVal;
19483 EltTy = LastEnumConst->getType();
19484
19485 // Check for overflow on increment.
19486 if (EnumVal < LastEnumConst->getInitVal()) {
19487 // C++0x [dcl.enum]p5:
19488 // If the underlying type is not fixed, the type of each enumerator
19489 // is the type of its initializing value:
19490 //
19491 // - Otherwise the type of the initializing value is the same as
19492 // the type of the initializing value of the preceding enumerator
19493 // unless the incremented value is not representable in that type,
19494 // in which case the type is an unspecified integral type
19495 // sufficient to contain the incremented value. If no such type
19496 // exists, the program is ill-formed.
19497 QualType T = getNextLargerIntegralType(Context, T: EltTy);
19498 if (T.isNull() || Enum->isFixed()) {
19499 // There is no integral type larger enough to represent this
19500 // value. Complain, then allow the value to wrap around.
19501 EnumVal = LastEnumConst->getInitVal();
19502 EnumVal = EnumVal.zext(width: EnumVal.getBitWidth() * 2);
19503 ++EnumVal;
19504 if (Enum->isFixed())
19505 // When the underlying type is fixed, this is ill-formed.
19506 Diag(Loc: IdLoc, DiagID: diag::err_enumerator_wrapped)
19507 << toString(I: EnumVal, Radix: 10)
19508 << EltTy;
19509 else
19510 Diag(Loc: IdLoc, DiagID: diag::ext_enumerator_increment_too_large)
19511 << toString(I: EnumVal, Radix: 10);
19512 } else {
19513 EltTy = T;
19514 }
19515
19516 // Retrieve the last enumerator's value, extent that type to the
19517 // type that is supposed to be large enough to represent the incremented
19518 // value, then increment.
19519 EnumVal = LastEnumConst->getInitVal();
19520 EnumVal.setIsSigned(EltTy->isSignedIntegerOrEnumerationType());
19521 EnumVal = EnumVal.zextOrTrunc(width: Context.getIntWidth(T: EltTy));
19522 ++EnumVal;
19523
19524 // If we're not in C++, diagnose the overflow of enumerator values,
19525 // which in C99 means that the enumerator value is not representable in
19526 // an int (C99 6.7.2.2p2). However, we support GCC's extension that
19527 // permits enumerator values that are representable in some larger
19528 // integral type.
19529 if (!getLangOpts().CPlusPlus && !T.isNull())
19530 Diag(Loc: IdLoc, DiagID: diag::warn_enum_value_overflow);
19531 } else if (!getLangOpts().CPlusPlus &&
19532 !EltTy->isDependentType() &&
19533 !isRepresentableIntegerValue(Context, Value&: EnumVal, T: EltTy)) {
19534 // Enforce C99 6.7.2.2p2 even when we compute the next value.
19535 Diag(Loc: IdLoc, DiagID: diag::ext_enum_value_not_int)
19536 << toString(I: EnumVal, Radix: 10) << 1;
19537 }
19538 }
19539 }
19540
19541 if (!EltTy->isDependentType()) {
19542 // Make the enumerator value match the signedness and size of the
19543 // enumerator's type.
19544 EnumVal = EnumVal.extOrTrunc(width: Context.getIntWidth(T: EltTy));
19545 EnumVal.setIsSigned(EltTy->isSignedIntegerOrEnumerationType());
19546 }
19547
19548 return EnumConstantDecl::Create(C&: Context, DC: Enum, L: IdLoc, Id, T: EltTy,
19549 E: Val, V: EnumVal);
19550}
19551
19552SkipBodyInfo Sema::shouldSkipAnonEnumBody(Scope *S, IdentifierInfo *II,
19553 SourceLocation IILoc) {
19554 if (!(getLangOpts().Modules || getLangOpts().ModulesLocalVisibility) ||
19555 !getLangOpts().CPlusPlus)
19556 return SkipBodyInfo();
19557
19558 // We have an anonymous enum definition. Look up the first enumerator to
19559 // determine if we should merge the definition with an existing one and
19560 // skip the body.
19561 NamedDecl *PrevDecl = LookupSingleName(S, Name: II, Loc: IILoc, NameKind: LookupOrdinaryName,
19562 Redecl: forRedeclarationInCurContext());
19563 auto *PrevECD = dyn_cast_or_null<EnumConstantDecl>(Val: PrevDecl);
19564 if (!PrevECD)
19565 return SkipBodyInfo();
19566
19567 EnumDecl *PrevED = cast<EnumDecl>(Val: PrevECD->getDeclContext());
19568 NamedDecl *Hidden;
19569 if (!PrevED->getDeclName() && !hasVisibleDefinition(D: PrevED, Suggested: &Hidden)) {
19570 SkipBodyInfo Skip;
19571 Skip.Previous = Hidden;
19572 return Skip;
19573 }
19574
19575 return SkipBodyInfo();
19576}
19577
19578Decl *Sema::ActOnEnumConstant(Scope *S, Decl *theEnumDecl, Decl *lastEnumConst,
19579 SourceLocation IdLoc, IdentifierInfo *Id,
19580 const ParsedAttributesView &Attrs,
19581 SourceLocation EqualLoc, Expr *Val) {
19582 EnumDecl *TheEnumDecl = cast<EnumDecl>(Val: theEnumDecl);
19583 EnumConstantDecl *LastEnumConst =
19584 cast_or_null<EnumConstantDecl>(Val: lastEnumConst);
19585
19586 // The scope passed in may not be a decl scope. Zip up the scope tree until
19587 // we find one that is.
19588 S = getNonFieldDeclScope(S);
19589
19590 // Verify that there isn't already something declared with this name in this
19591 // scope.
19592 LookupResult R(*this, Id, IdLoc, LookupOrdinaryName,
19593 RedeclarationKind::ForVisibleRedeclaration);
19594 LookupName(R, S);
19595 NamedDecl *PrevDecl = R.getAsSingle<NamedDecl>();
19596
19597 if (PrevDecl && PrevDecl->isTemplateParameter()) {
19598 // Maybe we will complain about the shadowed template parameter.
19599 DiagnoseTemplateParameterShadow(Loc: IdLoc, PrevDecl);
19600 // Just pretend that we didn't see the previous declaration.
19601 PrevDecl = nullptr;
19602 }
19603
19604 // C++ [class.mem]p15:
19605 // If T is the name of a class, then each of the following shall have a name
19606 // different from T:
19607 // - every enumerator of every member of class T that is an unscoped
19608 // enumerated type
19609 if (getLangOpts().CPlusPlus && !TheEnumDecl->isScoped())
19610 DiagnoseClassNameShadow(DC: TheEnumDecl->getDeclContext(),
19611 NameInfo: DeclarationNameInfo(Id, IdLoc));
19612
19613 EnumConstantDecl *New =
19614 CheckEnumConstant(Enum: TheEnumDecl, LastEnumConst, IdLoc, Id, Val);
19615 if (!New)
19616 return nullptr;
19617
19618 if (PrevDecl) {
19619 if (!TheEnumDecl->isScoped() && isa<ValueDecl>(Val: PrevDecl)) {
19620 // Check for other kinds of shadowing not already handled.
19621 CheckShadow(D: New, ShadowedDecl: PrevDecl, R);
19622 }
19623
19624 // When in C++, we may get a TagDecl with the same name; in this case the
19625 // enum constant will 'hide' the tag.
19626 assert((getLangOpts().CPlusPlus || !isa<TagDecl>(PrevDecl)) &&
19627 "Received TagDecl when not in C++!");
19628 if (!isa<TagDecl>(Val: PrevDecl) && isDeclInScope(D: PrevDecl, Ctx: CurContext, S)) {
19629 if (isa<EnumConstantDecl>(Val: PrevDecl))
19630 Diag(Loc: IdLoc, DiagID: diag::err_redefinition_of_enumerator) << Id;
19631 else
19632 Diag(Loc: IdLoc, DiagID: diag::err_redefinition) << Id;
19633 notePreviousDefinition(Old: PrevDecl, New: IdLoc);
19634 return nullptr;
19635 }
19636 }
19637
19638 // Process attributes.
19639 ProcessDeclAttributeList(S, D: New, AttrList: Attrs);
19640 AddPragmaAttributes(S, D: New);
19641 ProcessAPINotes(D: New);
19642
19643 // Register this decl in the current scope stack.
19644 New->setAccess(TheEnumDecl->getAccess());
19645 PushOnScopeChains(D: New, S);
19646
19647 ActOnDocumentableDecl(D: New);
19648
19649 return New;
19650}
19651
19652// Returns true when the enum initial expression does not trigger the
19653// duplicate enum warning. A few common cases are exempted as follows:
19654// Element2 = Element1
19655// Element2 = Element1 + 1
19656// Element2 = Element1 - 1
19657// Where Element2 and Element1 are from the same enum.
19658static bool ValidDuplicateEnum(EnumConstantDecl *ECD, EnumDecl *Enum) {
19659 Expr *InitExpr = ECD->getInitExpr();
19660 if (!InitExpr)
19661 return true;
19662 InitExpr = InitExpr->IgnoreImpCasts();
19663
19664 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Val: InitExpr)) {
19665 if (!BO->isAdditiveOp())
19666 return true;
19667 IntegerLiteral *IL = dyn_cast<IntegerLiteral>(Val: BO->getRHS());
19668 if (!IL)
19669 return true;
19670 if (IL->getValue() != 1)
19671 return true;
19672
19673 InitExpr = BO->getLHS();
19674 }
19675
19676 // This checks if the elements are from the same enum.
19677 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Val: InitExpr);
19678 if (!DRE)
19679 return true;
19680
19681 EnumConstantDecl *EnumConstant = dyn_cast<EnumConstantDecl>(Val: DRE->getDecl());
19682 if (!EnumConstant)
19683 return true;
19684
19685 if (cast<EnumDecl>(Val: TagDecl::castFromDeclContext(DC: ECD->getDeclContext())) !=
19686 Enum)
19687 return true;
19688
19689 return false;
19690}
19691
19692// Emits a warning when an element is implicitly set a value that
19693// a previous element has already been set to.
19694static void CheckForDuplicateEnumValues(Sema &S, ArrayRef<Decl *> Elements,
19695 EnumDecl *Enum, QualType EnumType) {
19696 // Avoid anonymous enums
19697 if (!Enum->getIdentifier())
19698 return;
19699
19700 // Only check for small enums.
19701 if (Enum->getNumPositiveBits() > 63 || Enum->getNumNegativeBits() > 64)
19702 return;
19703
19704 if (S.Diags.isIgnored(DiagID: diag::warn_duplicate_enum_values, Loc: Enum->getLocation()))
19705 return;
19706
19707 typedef SmallVector<EnumConstantDecl *, 3> ECDVector;
19708 typedef SmallVector<std::unique_ptr<ECDVector>, 3> DuplicatesVector;
19709
19710 typedef llvm::PointerUnion<EnumConstantDecl*, ECDVector*> DeclOrVector;
19711
19712 // DenseMaps cannot contain the all ones int64_t value, so use unordered_map.
19713 typedef std::unordered_map<int64_t, DeclOrVector> ValueToVectorMap;
19714
19715 // Use int64_t as a key to avoid needing special handling for map keys.
19716 auto EnumConstantToKey = [](const EnumConstantDecl *D) {
19717 llvm::APSInt Val = D->getInitVal();
19718 return Val.isSigned() ? Val.getSExtValue() : Val.getZExtValue();
19719 };
19720
19721 DuplicatesVector DupVector;
19722 ValueToVectorMap EnumMap;
19723
19724 // Populate the EnumMap with all values represented by enum constants without
19725 // an initializer.
19726 for (auto *Element : Elements) {
19727 EnumConstantDecl *ECD = cast_or_null<EnumConstantDecl>(Val: Element);
19728
19729 // Null EnumConstantDecl means a previous diagnostic has been emitted for
19730 // this constant. Skip this enum since it may be ill-formed.
19731 if (!ECD) {
19732 return;
19733 }
19734
19735 // Constants with initializers are handled in the next loop.
19736 if (ECD->getInitExpr())
19737 continue;
19738
19739 // Duplicate values are handled in the next loop.
19740 EnumMap.insert(x: {EnumConstantToKey(ECD), ECD});
19741 }
19742
19743 if (EnumMap.size() == 0)
19744 return;
19745
19746 // Create vectors for any values that has duplicates.
19747 for (auto *Element : Elements) {
19748 // The last loop returned if any constant was null.
19749 EnumConstantDecl *ECD = cast<EnumConstantDecl>(Val: Element);
19750 if (!ValidDuplicateEnum(ECD, Enum))
19751 continue;
19752
19753 auto Iter = EnumMap.find(x: EnumConstantToKey(ECD));
19754 if (Iter == EnumMap.end())
19755 continue;
19756
19757 DeclOrVector& Entry = Iter->second;
19758 if (EnumConstantDecl *D = Entry.dyn_cast<EnumConstantDecl*>()) {
19759 // Ensure constants are different.
19760 if (D == ECD)
19761 continue;
19762
19763 // Create new vector and push values onto it.
19764 auto Vec = std::make_unique<ECDVector>();
19765 Vec->push_back(Elt: D);
19766 Vec->push_back(Elt: ECD);
19767
19768 // Update entry to point to the duplicates vector.
19769 Entry = Vec.get();
19770
19771 // Store the vector somewhere we can consult later for quick emission of
19772 // diagnostics.
19773 DupVector.emplace_back(Args: std::move(Vec));
19774 continue;
19775 }
19776
19777 ECDVector *Vec = Entry.get<ECDVector*>();
19778 // Make sure constants are not added more than once.
19779 if (*Vec->begin() == ECD)
19780 continue;
19781
19782 Vec->push_back(Elt: ECD);
19783 }
19784
19785 // Emit diagnostics.
19786 for (const auto &Vec : DupVector) {
19787 assert(Vec->size() > 1 && "ECDVector should have at least 2 elements.");
19788
19789 // Emit warning for one enum constant.
19790 auto *FirstECD = Vec->front();
19791 S.Diag(Loc: FirstECD->getLocation(), DiagID: diag::warn_duplicate_enum_values)
19792 << FirstECD << toString(I: FirstECD->getInitVal(), Radix: 10)
19793 << FirstECD->getSourceRange();
19794
19795 // Emit one note for each of the remaining enum constants with
19796 // the same value.
19797 for (auto *ECD : llvm::drop_begin(RangeOrContainer&: *Vec))
19798 S.Diag(Loc: ECD->getLocation(), DiagID: diag::note_duplicate_element)
19799 << ECD << toString(I: ECD->getInitVal(), Radix: 10)
19800 << ECD->getSourceRange();
19801 }
19802}
19803
19804bool Sema::IsValueInFlagEnum(const EnumDecl *ED, const llvm::APInt &Val,
19805 bool AllowMask) const {
19806 assert(ED->isClosedFlag() && "looking for value in non-flag or open enum");
19807 assert(ED->isCompleteDefinition() && "expected enum definition");
19808
19809 auto R = FlagBitsCache.insert(KV: std::make_pair(x&: ED, y: llvm::APInt()));
19810 llvm::APInt &FlagBits = R.first->second;
19811
19812 if (R.second) {
19813 for (auto *E : ED->enumerators()) {
19814 const auto &EVal = E->getInitVal();
19815 // Only single-bit enumerators introduce new flag values.
19816 if (EVal.isPowerOf2())
19817 FlagBits = FlagBits.zext(width: EVal.getBitWidth()) | EVal;
19818 }
19819 }
19820
19821 // A value is in a flag enum if either its bits are a subset of the enum's
19822 // flag bits (the first condition) or we are allowing masks and the same is
19823 // true of its complement (the second condition). When masks are allowed, we
19824 // allow the common idiom of ~(enum1 | enum2) to be a valid enum value.
19825 //
19826 // While it's true that any value could be used as a mask, the assumption is
19827 // that a mask will have all of the insignificant bits set. Anything else is
19828 // likely a logic error.
19829 llvm::APInt FlagMask = ~FlagBits.zextOrTrunc(width: Val.getBitWidth());
19830 return !(FlagMask & Val) || (AllowMask && !(FlagMask & ~Val));
19831}
19832
19833void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange,
19834 Decl *EnumDeclX, ArrayRef<Decl *> Elements, Scope *S,
19835 const ParsedAttributesView &Attrs) {
19836 EnumDecl *Enum = cast<EnumDecl>(Val: EnumDeclX);
19837 QualType EnumType = Context.getTypeDeclType(Decl: Enum);
19838
19839 ProcessDeclAttributeList(S, D: Enum, AttrList: Attrs);
19840 ProcessAPINotes(D: Enum);
19841
19842 if (Enum->isDependentType()) {
19843 for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
19844 EnumConstantDecl *ECD =
19845 cast_or_null<EnumConstantDecl>(Val: Elements[i]);
19846 if (!ECD) continue;
19847
19848 ECD->setType(EnumType);
19849 }
19850
19851 Enum->completeDefinition(NewType: Context.DependentTy, PromotionType: Context.DependentTy, NumPositiveBits: 0, NumNegativeBits: 0);
19852 return;
19853 }
19854
19855 // TODO: If the result value doesn't fit in an int, it must be a long or long
19856 // long value. ISO C does not support this, but GCC does as an extension,
19857 // emit a warning.
19858 unsigned IntWidth = Context.getTargetInfo().getIntWidth();
19859 unsigned CharWidth = Context.getTargetInfo().getCharWidth();
19860 unsigned ShortWidth = Context.getTargetInfo().getShortWidth();
19861
19862 // Verify that all the values are okay, compute the size of the values, and
19863 // reverse the list.
19864 unsigned NumNegativeBits = 0;
19865 unsigned NumPositiveBits = 0;
19866
19867 for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
19868 EnumConstantDecl *ECD =
19869 cast_or_null<EnumConstantDecl>(Val: Elements[i]);
19870 if (!ECD) continue; // Already issued a diagnostic.
19871
19872 const llvm::APSInt &InitVal = ECD->getInitVal();
19873
19874 // Keep track of the size of positive and negative values.
19875 if (InitVal.isUnsigned() || InitVal.isNonNegative()) {
19876 // If the enumerator is zero that should still be counted as a positive
19877 // bit since we need a bit to store the value zero.
19878 unsigned ActiveBits = InitVal.getActiveBits();
19879 NumPositiveBits = std::max(l: {NumPositiveBits, ActiveBits, 1u});
19880 } else {
19881 NumNegativeBits =
19882 std::max(a: NumNegativeBits, b: (unsigned)InitVal.getSignificantBits());
19883 }
19884 }
19885
19886 // If we have an empty set of enumerators we still need one bit.
19887 // From [dcl.enum]p8
19888 // If the enumerator-list is empty, the values of the enumeration are as if
19889 // the enumeration had a single enumerator with value 0
19890 if (!NumPositiveBits && !NumNegativeBits)
19891 NumPositiveBits = 1;
19892
19893 // Figure out the type that should be used for this enum.
19894 QualType BestType;
19895 unsigned BestWidth;
19896
19897 // C++0x N3000 [conv.prom]p3:
19898 // An rvalue of an unscoped enumeration type whose underlying
19899 // type is not fixed can be converted to an rvalue of the first
19900 // of the following types that can represent all the values of
19901 // the enumeration: int, unsigned int, long int, unsigned long
19902 // int, long long int, or unsigned long long int.
19903 // C99 6.4.4.3p2:
19904 // An identifier declared as an enumeration constant has type int.
19905 // The C99 rule is modified by a gcc extension
19906 QualType BestPromotionType;
19907
19908 bool Packed = Enum->hasAttr<PackedAttr>();
19909 // -fshort-enums is the equivalent to specifying the packed attribute on all
19910 // enum definitions.
19911 if (LangOpts.ShortEnums)
19912 Packed = true;
19913
19914 // If the enum already has a type because it is fixed or dictated by the
19915 // target, promote that type instead of analyzing the enumerators.
19916 if (Enum->isComplete()) {
19917 BestType = Enum->getIntegerType();
19918 if (Context.isPromotableIntegerType(T: BestType))
19919 BestPromotionType = Context.getPromotedIntegerType(PromotableType: BestType);
19920 else
19921 BestPromotionType = BestType;
19922
19923 BestWidth = Context.getIntWidth(T: BestType);
19924 }
19925 else if (NumNegativeBits) {
19926 // If there is a negative value, figure out the smallest integer type (of
19927 // int/long/longlong) that fits.
19928 // If it's packed, check also if it fits a char or a short.
19929 if (Packed && NumNegativeBits <= CharWidth && NumPositiveBits < CharWidth) {
19930 BestType = Context.SignedCharTy;
19931 BestWidth = CharWidth;
19932 } else if (Packed && NumNegativeBits <= ShortWidth &&
19933 NumPositiveBits < ShortWidth) {
19934 BestType = Context.ShortTy;
19935 BestWidth = ShortWidth;
19936 } else if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) {
19937 BestType = Context.IntTy;
19938 BestWidth = IntWidth;
19939 } else {
19940 BestWidth = Context.getTargetInfo().getLongWidth();
19941
19942 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) {
19943 BestType = Context.LongTy;
19944 } else {
19945 BestWidth = Context.getTargetInfo().getLongLongWidth();
19946
19947 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth)
19948 Diag(Loc: Enum->getLocation(), DiagID: diag::ext_enum_too_large);
19949 BestType = Context.LongLongTy;
19950 }
19951 }
19952 BestPromotionType = (BestWidth <= IntWidth ? Context.IntTy : BestType);
19953 } else {
19954 // If there is no negative value, figure out the smallest type that fits
19955 // all of the enumerator values.
19956 // If it's packed, check also if it fits a char or a short.
19957 if (Packed && NumPositiveBits <= CharWidth) {
19958 BestType = Context.UnsignedCharTy;
19959 BestPromotionType = Context.IntTy;
19960 BestWidth = CharWidth;
19961 } else if (Packed && NumPositiveBits <= ShortWidth) {
19962 BestType = Context.UnsignedShortTy;
19963 BestPromotionType = Context.IntTy;
19964 BestWidth = ShortWidth;
19965 } else if (NumPositiveBits <= IntWidth) {
19966 BestType = Context.UnsignedIntTy;
19967 BestWidth = IntWidth;
19968 BestPromotionType
19969 = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus)
19970 ? Context.UnsignedIntTy : Context.IntTy;
19971 } else if (NumPositiveBits <=
19972 (BestWidth = Context.getTargetInfo().getLongWidth())) {
19973 BestType = Context.UnsignedLongTy;
19974 BestPromotionType
19975 = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus)
19976 ? Context.UnsignedLongTy : Context.LongTy;
19977 } else {
19978 BestWidth = Context.getTargetInfo().getLongLongWidth();
19979 if (NumPositiveBits > BestWidth) {
19980 // This can happen with bit-precise integer types, but those are not
19981 // allowed as the type for an enumerator per C23 6.7.2.2p4 and p12.
19982 // FIXME: GCC uses __int128_t and __uint128_t for cases that fit within
19983 // a 128-bit integer, we should consider doing the same.
19984 Diag(Loc: Enum->getLocation(), DiagID: diag::ext_enum_too_large);
19985 }
19986 BestType = Context.UnsignedLongLongTy;
19987 BestPromotionType
19988 = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus)
19989 ? Context.UnsignedLongLongTy : Context.LongLongTy;
19990 }
19991 }
19992
19993 // Loop over all of the enumerator constants, changing their types to match
19994 // the type of the enum if needed.
19995 for (auto *D : Elements) {
19996 auto *ECD = cast_or_null<EnumConstantDecl>(Val: D);
19997 if (!ECD) continue; // Already issued a diagnostic.
19998
19999 // Standard C says the enumerators have int type, but we allow, as an
20000 // extension, the enumerators to be larger than int size. If each
20001 // enumerator value fits in an int, type it as an int, otherwise type it the
20002 // same as the enumerator decl itself. This means that in "enum { X = 1U }"
20003 // that X has type 'int', not 'unsigned'.
20004
20005 // Determine whether the value fits into an int.
20006 llvm::APSInt InitVal = ECD->getInitVal();
20007
20008 // If it fits into an integer type, force it. Otherwise force it to match
20009 // the enum decl type.
20010 QualType NewTy;
20011 unsigned NewWidth;
20012 bool NewSign;
20013 if (!getLangOpts().CPlusPlus &&
20014 !Enum->isFixed() &&
20015 isRepresentableIntegerValue(Context, Value&: InitVal, T: Context.IntTy)) {
20016 NewTy = Context.IntTy;
20017 NewWidth = IntWidth;
20018 NewSign = true;
20019 } else if (ECD->getType() == BestType) {
20020 // Already the right type!
20021 if (getLangOpts().CPlusPlus)
20022 // C++ [dcl.enum]p4: Following the closing brace of an
20023 // enum-specifier, each enumerator has the type of its
20024 // enumeration.
20025 ECD->setType(EnumType);
20026 continue;
20027 } else {
20028 NewTy = BestType;
20029 NewWidth = BestWidth;
20030 NewSign = BestType->isSignedIntegerOrEnumerationType();
20031 }
20032
20033 // Adjust the APSInt value.
20034 InitVal = InitVal.extOrTrunc(width: NewWidth);
20035 InitVal.setIsSigned(NewSign);
20036 ECD->setInitVal(C: Context, V: InitVal);
20037
20038 // Adjust the Expr initializer and type.
20039 if (ECD->getInitExpr() &&
20040 !Context.hasSameType(T1: NewTy, T2: ECD->getInitExpr()->getType()))
20041 ECD->setInitExpr(ImplicitCastExpr::Create(
20042 Context, T: NewTy, Kind: CK_IntegralCast, Operand: ECD->getInitExpr(),
20043 /*base paths*/ BasePath: nullptr, Cat: VK_PRValue, FPO: FPOptionsOverride()));
20044 if (getLangOpts().CPlusPlus)
20045 // C++ [dcl.enum]p4: Following the closing brace of an
20046 // enum-specifier, each enumerator has the type of its
20047 // enumeration.
20048 ECD->setType(EnumType);
20049 else
20050 ECD->setType(NewTy);
20051 }
20052
20053 Enum->completeDefinition(NewType: BestType, PromotionType: BestPromotionType,
20054 NumPositiveBits, NumNegativeBits);
20055
20056 CheckForDuplicateEnumValues(S&: *this, Elements, Enum, EnumType);
20057
20058 if (Enum->isClosedFlag()) {
20059 for (Decl *D : Elements) {
20060 EnumConstantDecl *ECD = cast_or_null<EnumConstantDecl>(Val: D);
20061 if (!ECD) continue; // Already issued a diagnostic.
20062
20063 llvm::APSInt InitVal = ECD->getInitVal();
20064 if (InitVal != 0 && !InitVal.isPowerOf2() &&
20065 !IsValueInFlagEnum(ED: Enum, Val: InitVal, AllowMask: true))
20066 Diag(Loc: ECD->getLocation(), DiagID: diag::warn_flag_enum_constant_out_of_range)
20067 << ECD << Enum;
20068 }
20069 }
20070
20071 // Now that the enum type is defined, ensure it's not been underaligned.
20072 if (Enum->hasAttrs())
20073 CheckAlignasUnderalignment(D: Enum);
20074}
20075
20076Decl *Sema::ActOnFileScopeAsmDecl(Expr *expr,
20077 SourceLocation StartLoc,
20078 SourceLocation EndLoc) {
20079 StringLiteral *AsmString = cast<StringLiteral>(Val: expr);
20080
20081 FileScopeAsmDecl *New = FileScopeAsmDecl::Create(C&: Context, DC: CurContext,
20082 Str: AsmString, AsmLoc: StartLoc,
20083 RParenLoc: EndLoc);
20084 CurContext->addDecl(D: New);
20085 return New;
20086}
20087
20088TopLevelStmtDecl *Sema::ActOnStartTopLevelStmtDecl(Scope *S) {
20089 auto *New = TopLevelStmtDecl::Create(C&: Context, /*Statement=*/nullptr);
20090 CurContext->addDecl(D: New);
20091 PushDeclContext(S, DC: New);
20092 PushFunctionScope();
20093 PushCompoundScope(IsStmtExpr: false);
20094 return New;
20095}
20096
20097void Sema::ActOnFinishTopLevelStmtDecl(TopLevelStmtDecl *D, Stmt *Statement) {
20098 D->setStmt(Statement);
20099 PopCompoundScope();
20100 PopFunctionScopeInfo();
20101 PopDeclContext();
20102}
20103
20104void Sema::ActOnPragmaRedefineExtname(IdentifierInfo* Name,
20105 IdentifierInfo* AliasName,
20106 SourceLocation PragmaLoc,
20107 SourceLocation NameLoc,
20108 SourceLocation AliasNameLoc) {
20109 NamedDecl *PrevDecl = LookupSingleName(S: TUScope, Name, Loc: NameLoc,
20110 NameKind: LookupOrdinaryName);
20111 AttributeCommonInfo Info(AliasName, SourceRange(AliasNameLoc),
20112 AttributeCommonInfo::Form::Pragma());
20113 AsmLabelAttr *Attr = AsmLabelAttr::CreateImplicit(
20114 Ctx&: Context, Label: AliasName->getName(), /*IsLiteralLabel=*/true, CommonInfo: Info);
20115
20116 // If a declaration that:
20117 // 1) declares a function or a variable
20118 // 2) has external linkage
20119 // already exists, add a label attribute to it.
20120 if (PrevDecl && (isa<FunctionDecl>(Val: PrevDecl) || isa<VarDecl>(Val: PrevDecl))) {
20121 if (isDeclExternC(D: PrevDecl))
20122 PrevDecl->addAttr(A: Attr);
20123 else
20124 Diag(Loc: PrevDecl->getLocation(), DiagID: diag::warn_redefine_extname_not_applied)
20125 << /*Variable*/(isa<FunctionDecl>(Val: PrevDecl) ? 0 : 1) << PrevDecl;
20126 // Otherwise, add a label attribute to ExtnameUndeclaredIdentifiers.
20127 } else
20128 (void)ExtnameUndeclaredIdentifiers.insert(KV: std::make_pair(x&: Name, y&: Attr));
20129}
20130
20131void Sema::ActOnPragmaWeakID(IdentifierInfo* Name,
20132 SourceLocation PragmaLoc,
20133 SourceLocation NameLoc) {
20134 Decl *PrevDecl = LookupSingleName(S: TUScope, Name, Loc: NameLoc, NameKind: LookupOrdinaryName);
20135
20136 if (PrevDecl) {
20137 PrevDecl->addAttr(A: WeakAttr::CreateImplicit(Ctx&: Context, Range: PragmaLoc));
20138 } else {
20139 (void)WeakUndeclaredIdentifiers[Name].insert(X: WeakInfo(nullptr, NameLoc));
20140 }
20141}
20142
20143void Sema::ActOnPragmaWeakAlias(IdentifierInfo* Name,
20144 IdentifierInfo* AliasName,
20145 SourceLocation PragmaLoc,
20146 SourceLocation NameLoc,
20147 SourceLocation AliasNameLoc) {
20148 Decl *PrevDecl = LookupSingleName(S: TUScope, Name: AliasName, Loc: AliasNameLoc,
20149 NameKind: LookupOrdinaryName);
20150 WeakInfo W = WeakInfo(Name, NameLoc);
20151
20152 if (PrevDecl && (isa<FunctionDecl>(Val: PrevDecl) || isa<VarDecl>(Val: PrevDecl))) {
20153 if (!PrevDecl->hasAttr<AliasAttr>())
20154 if (NamedDecl *ND = dyn_cast<NamedDecl>(Val: PrevDecl))
20155 DeclApplyPragmaWeak(S: TUScope, ND, W);
20156 } else {
20157 (void)WeakUndeclaredIdentifiers[AliasName].insert(X: W);
20158 }
20159}
20160
20161Sema::FunctionEmissionStatus Sema::getEmissionStatus(const FunctionDecl *FD,
20162 bool Final) {
20163 assert(FD && "Expected non-null FunctionDecl");
20164
20165 // SYCL functions can be template, so we check if they have appropriate
20166 // attribute prior to checking if it is a template.
20167 if (LangOpts.SYCLIsDevice && FD->hasAttr<SYCLKernelAttr>())
20168 return FunctionEmissionStatus::Emitted;
20169
20170 // Templates are emitted when they're instantiated.
20171 if (FD->isDependentContext())
20172 return FunctionEmissionStatus::TemplateDiscarded;
20173
20174 // Check whether this function is an externally visible definition.
20175 auto IsEmittedForExternalSymbol = [this, FD]() {
20176 // We have to check the GVA linkage of the function's *definition* -- if we
20177 // only have a declaration, we don't know whether or not the function will
20178 // be emitted, because (say) the definition could include "inline".
20179 const FunctionDecl *Def = FD->getDefinition();
20180
20181 return Def && !isDiscardableGVALinkage(
20182 L: getASTContext().GetGVALinkageForFunction(FD: Def));
20183 };
20184
20185 if (LangOpts.OpenMPIsTargetDevice) {
20186 // In OpenMP device mode we will not emit host only functions, or functions
20187 // we don't need due to their linkage.
20188 std::optional<OMPDeclareTargetDeclAttr::DevTypeTy> DevTy =
20189 OMPDeclareTargetDeclAttr::getDeviceType(VD: FD->getCanonicalDecl());
20190 // DevTy may be changed later by
20191 // #pragma omp declare target to(*) device_type(*).
20192 // Therefore DevTy having no value does not imply host. The emission status
20193 // will be checked again at the end of compilation unit with Final = true.
20194 if (DevTy)
20195 if (*DevTy == OMPDeclareTargetDeclAttr::DT_Host)
20196 return FunctionEmissionStatus::OMPDiscarded;
20197 // If we have an explicit value for the device type, or we are in a target
20198 // declare context, we need to emit all extern and used symbols.
20199 if (OpenMP().isInOpenMPDeclareTargetContext() || DevTy)
20200 if (IsEmittedForExternalSymbol())
20201 return FunctionEmissionStatus::Emitted;
20202 // Device mode only emits what it must, if it wasn't tagged yet and needed,
20203 // we'll omit it.
20204 if (Final)
20205 return FunctionEmissionStatus::OMPDiscarded;
20206 } else if (LangOpts.OpenMP > 45) {
20207 // In OpenMP host compilation prior to 5.0 everything was an emitted host
20208 // function. In 5.0, no_host was introduced which might cause a function to
20209 // be omitted.
20210 std::optional<OMPDeclareTargetDeclAttr::DevTypeTy> DevTy =
20211 OMPDeclareTargetDeclAttr::getDeviceType(VD: FD->getCanonicalDecl());
20212 if (DevTy)
20213 if (*DevTy == OMPDeclareTargetDeclAttr::DT_NoHost)
20214 return FunctionEmissionStatus::OMPDiscarded;
20215 }
20216
20217 if (Final && LangOpts.OpenMP && !LangOpts.CUDA)
20218 return FunctionEmissionStatus::Emitted;
20219
20220 if (LangOpts.CUDA) {
20221 // When compiling for device, host functions are never emitted. Similarly,
20222 // when compiling for host, device and global functions are never emitted.
20223 // (Technically, we do emit a host-side stub for global functions, but this
20224 // doesn't count for our purposes here.)
20225 CUDAFunctionTarget T = CUDA().IdentifyTarget(D: FD);
20226 if (LangOpts.CUDAIsDevice && T == CUDAFunctionTarget::Host)
20227 return FunctionEmissionStatus::CUDADiscarded;
20228 if (!LangOpts.CUDAIsDevice &&
20229 (T == CUDAFunctionTarget::Device || T == CUDAFunctionTarget::Global))
20230 return FunctionEmissionStatus::CUDADiscarded;
20231
20232 if (IsEmittedForExternalSymbol())
20233 return FunctionEmissionStatus::Emitted;
20234 }
20235
20236 // Otherwise, the function is known-emitted if it's in our set of
20237 // known-emitted functions.
20238 return FunctionEmissionStatus::Unknown;
20239}
20240
20241bool Sema::shouldIgnoreInHostDeviceCheck(FunctionDecl *Callee) {
20242 // Host-side references to a __global__ function refer to the stub, so the
20243 // function itself is never emitted and therefore should not be marked.
20244 // If we have host fn calls kernel fn calls host+device, the HD function
20245 // does not get instantiated on the host. We model this by omitting at the
20246 // call to the kernel from the callgraph. This ensures that, when compiling
20247 // for host, only HD functions actually called from the host get marked as
20248 // known-emitted.
20249 return LangOpts.CUDA && !LangOpts.CUDAIsDevice &&
20250 CUDA().IdentifyTarget(D: Callee) == CUDAFunctionTarget::Global;
20251}
20252
20253void Sema::diagnoseFunctionEffectMergeConflicts(
20254 const FunctionEffectSet::Conflicts &Errs, SourceLocation NewLoc,
20255 SourceLocation OldLoc) {
20256 for (const FunctionEffectSet::Conflict &Conflict : Errs) {
20257 Diag(Loc: NewLoc, DiagID: diag::warn_conflicting_func_effects)
20258 << Conflict.Kept.description() << Conflict.Rejected.description();
20259 Diag(Loc: OldLoc, DiagID: diag::note_previous_declaration);
20260 }
20261}
20262
20263bool Sema::diagnoseConflictingFunctionEffect(
20264 const FunctionEffectsRef &FX, const FunctionEffectWithCondition &NewEC,
20265 SourceLocation NewAttrLoc) {
20266 // If the new effect has a condition, we can't detect conflicts until the
20267 // condition is resolved.
20268 if (NewEC.Cond.getCondition() != nullptr)
20269 return false;
20270
20271 // Diagnose the new attribute as incompatible with a previous one.
20272 auto Incompatible = [&](const FunctionEffectWithCondition &PrevEC) {
20273 Diag(Loc: NewAttrLoc, DiagID: diag::err_attributes_are_not_compatible)
20274 << ("'" + NewEC.description() + "'")
20275 << ("'" + PrevEC.description() + "'") << false;
20276 // We don't necessarily have the location of the previous attribute,
20277 // so no note.
20278 return true;
20279 };
20280
20281 // Compare against previous attributes.
20282 FunctionEffect::Kind NewKind = NewEC.Effect.kind();
20283
20284 for (const FunctionEffectWithCondition &PrevEC : FX) {
20285 // Again, can't check yet when the effect is conditional.
20286 if (PrevEC.Cond.getCondition() != nullptr)
20287 continue;
20288
20289 FunctionEffect::Kind PrevKind = PrevEC.Effect.kind();
20290 // Note that we allow PrevKind == NewKind; it's redundant and ignored.
20291
20292 if (PrevEC.Effect.oppositeKind() == NewKind)
20293 return Incompatible(PrevEC);
20294
20295 // A new allocating is incompatible with a previous nonblocking.
20296 if (PrevKind == FunctionEffect::Kind::NonBlocking &&
20297 NewKind == FunctionEffect::Kind::Allocating)
20298 return Incompatible(PrevEC);
20299
20300 // A new nonblocking is incompatible with a previous allocating.
20301 if (PrevKind == FunctionEffect::Kind::Allocating &&
20302 NewKind == FunctionEffect::Kind::NonBlocking)
20303 return Incompatible(PrevEC);
20304 }
20305
20306 return false;
20307}
20308