1//===--------------------- SemaLookup.cpp - Name Lookup ------------------===//
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 name lookup for C, C++, Objective-C, and
10// Objective-C++.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/AST/ASTContext.h"
15#include "clang/AST/CXXInheritance.h"
16#include "clang/AST/Decl.h"
17#include "clang/AST/DeclCXX.h"
18#include "clang/AST/DeclLookups.h"
19#include "clang/AST/DeclObjC.h"
20#include "clang/AST/DeclTemplate.h"
21#include "clang/AST/Expr.h"
22#include "clang/AST/ExprCXX.h"
23#include "clang/Basic/Builtins.h"
24#include "clang/Basic/LangOptions.h"
25#include "clang/Basic/TargetInfo.h"
26#include "clang/Lex/HeaderSearch.h"
27#include "clang/Lex/ModuleLoader.h"
28#include "clang/Lex/Preprocessor.h"
29#include "clang/Sema/DeclSpec.h"
30#include "clang/Sema/Lookup.h"
31#include "clang/Sema/Overload.h"
32#include "clang/Sema/RISCVIntrinsicManager.h"
33#include "clang/Sema/Scope.h"
34#include "clang/Sema/ScopeInfo.h"
35#include "clang/Sema/Sema.h"
36#include "clang/Sema/SemaInternal.h"
37#include "clang/Sema/SemaRISCV.h"
38#include "clang/Sema/TemplateDeduction.h"
39#include "clang/Sema/TypoCorrection.h"
40#include "llvm/ADT/STLExtras.h"
41#include "llvm/ADT/STLForwardCompat.h"
42#include "llvm/ADT/SmallPtrSet.h"
43#include "llvm/ADT/TinyPtrVector.h"
44#include "llvm/ADT/edit_distance.h"
45#include "llvm/Support/Casting.h"
46#include "llvm/Support/ErrorHandling.h"
47#include <algorithm>
48#include <iterator>
49#include <list>
50#include <optional>
51#include <set>
52#include <utility>
53#include <vector>
54
55#include "OpenCLBuiltins.inc"
56
57using namespace clang;
58using namespace sema;
59
60namespace {
61 class UnqualUsingEntry {
62 const DeclContext *Nominated;
63 const DeclContext *CommonAncestor;
64
65 public:
66 UnqualUsingEntry(const DeclContext *Nominated,
67 const DeclContext *CommonAncestor)
68 : Nominated(Nominated), CommonAncestor(CommonAncestor) {
69 }
70
71 const DeclContext *getCommonAncestor() const {
72 return CommonAncestor;
73 }
74
75 const DeclContext *getNominatedNamespace() const {
76 return Nominated;
77 }
78
79 // Sort by the pointer value of the common ancestor.
80 struct Comparator {
81 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) {
82 return L.getCommonAncestor() < R.getCommonAncestor();
83 }
84
85 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) {
86 return E.getCommonAncestor() < DC;
87 }
88
89 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) {
90 return DC < E.getCommonAncestor();
91 }
92 };
93 };
94
95 /// A collection of using directives, as used by C++ unqualified
96 /// lookup.
97 class UnqualUsingDirectiveSet {
98 Sema &SemaRef;
99
100 typedef SmallVector<UnqualUsingEntry, 8> ListTy;
101
102 ListTy list;
103 llvm::SmallPtrSet<DeclContext*, 8> visited;
104
105 public:
106 UnqualUsingDirectiveSet(Sema &SemaRef) : SemaRef(SemaRef) {}
107
108 void visitScopeChain(Scope *S, Scope *InnermostFileScope) {
109 // C++ [namespace.udir]p1:
110 // During unqualified name lookup, the names appear as if they
111 // were declared in the nearest enclosing namespace which contains
112 // both the using-directive and the nominated namespace.
113 DeclContext *InnermostFileDC = InnermostFileScope->getEntity();
114 assert(InnermostFileDC && InnermostFileDC->isFileContext());
115
116 for (; S; S = S->getParent()) {
117 // C++ [namespace.udir]p1:
118 // A using-directive shall not appear in class scope, but may
119 // appear in namespace scope or in block scope.
120 DeclContext *Ctx = S->getEntity();
121 if (Ctx && Ctx->isFileContext()) {
122 visit(DC: Ctx, EffectiveDC: Ctx);
123 } else if (!Ctx || Ctx->isFunctionOrMethod()) {
124 for (auto *I : S->using_directives())
125 if (SemaRef.isVisible(D: I))
126 visit(UD: I, EffectiveDC: InnermostFileDC);
127 }
128 }
129 }
130
131 // Visits a context and collect all of its using directives
132 // recursively. Treats all using directives as if they were
133 // declared in the context.
134 //
135 // A given context is only every visited once, so it is important
136 // that contexts be visited from the inside out in order to get
137 // the effective DCs right.
138 void visit(DeclContext *DC, DeclContext *EffectiveDC) {
139 if (!visited.insert(Ptr: DC).second)
140 return;
141
142 addUsingDirectives(DC, EffectiveDC);
143 }
144
145 // Visits a using directive and collects all of its using
146 // directives recursively. Treats all using directives as if they
147 // were declared in the effective DC.
148 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
149 DeclContext *NS = UD->getNominatedNamespace();
150 if (!visited.insert(Ptr: NS).second)
151 return;
152
153 addUsingDirective(UD, EffectiveDC);
154 addUsingDirectives(DC: NS, EffectiveDC);
155 }
156
157 // Adds all the using directives in a context (and those nominated
158 // by its using directives, transitively) as if they appeared in
159 // the given effective context.
160 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) {
161 SmallVector<DeclContext*, 4> queue;
162 while (true) {
163 for (auto *UD : DC->using_directives()) {
164 DeclContext *NS = UD->getNominatedNamespace();
165 if (SemaRef.isVisible(D: UD) && visited.insert(Ptr: NS).second) {
166 addUsingDirective(UD, EffectiveDC);
167 queue.push_back(Elt: NS);
168 }
169 }
170
171 if (queue.empty())
172 return;
173
174 DC = queue.pop_back_val();
175 }
176 }
177
178 // Add a using directive as if it had been declared in the given
179 // context. This helps implement C++ [namespace.udir]p3:
180 // The using-directive is transitive: if a scope contains a
181 // using-directive that nominates a second namespace that itself
182 // contains using-directives, the effect is as if the
183 // using-directives from the second namespace also appeared in
184 // the first.
185 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
186 // Find the common ancestor between the effective context and
187 // the nominated namespace.
188 DeclContext *Common = UD->getNominatedNamespace();
189 while (!Common->Encloses(DC: EffectiveDC))
190 Common = Common->getParent();
191 Common = Common->getPrimaryContext();
192
193 list.push_back(Elt: UnqualUsingEntry(UD->getNominatedNamespace(), Common));
194 }
195
196 void done() { llvm::stable_sort(Range&: list, C: UnqualUsingEntry::Comparator()); }
197
198 typedef ListTy::const_iterator const_iterator;
199
200 const_iterator begin() const { return list.begin(); }
201 const_iterator end() const { return list.end(); }
202
203 llvm::iterator_range<const_iterator>
204 getNamespacesFor(const DeclContext *DC) const {
205 return llvm::make_range(p: std::equal_range(first: begin(), last: end(),
206 val: DC->getPrimaryContext(),
207 comp: UnqualUsingEntry::Comparator()));
208 }
209 };
210} // end anonymous namespace
211
212// Retrieve the set of identifier namespaces that correspond to a
213// specific kind of name lookup.
214static inline unsigned getIDNS(Sema::LookupNameKind NameKind,
215 bool CPlusPlus,
216 bool Redeclaration) {
217 unsigned IDNS = 0;
218 switch (NameKind) {
219 case Sema::LookupObjCImplicitSelfParam:
220 case Sema::LookupOrdinaryName:
221 case Sema::LookupRedeclarationWithLinkage:
222 case Sema::LookupLocalFriendName:
223 case Sema::LookupDestructorName:
224 IDNS = Decl::IDNS_Ordinary;
225 if (CPlusPlus) {
226 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace;
227 if (Redeclaration)
228 IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend;
229 }
230 if (Redeclaration)
231 IDNS |= Decl::IDNS_LocalExtern;
232 break;
233
234 case Sema::LookupOperatorName:
235 // Operator lookup is its own crazy thing; it is not the same
236 // as (e.g.) looking up an operator name for redeclaration.
237 assert(!Redeclaration && "cannot do redeclaration operator lookup");
238 IDNS = Decl::IDNS_NonMemberOperator;
239 break;
240
241 case Sema::LookupTagName:
242 if (CPlusPlus) {
243 IDNS = Decl::IDNS_Type;
244
245 // When looking for a redeclaration of a tag name, we add:
246 // 1) TagFriend to find undeclared friend decls
247 // 2) Namespace because they can't "overload" with tag decls.
248 // 3) Tag because it includes class templates, which can't
249 // "overload" with tag decls.
250 if (Redeclaration)
251 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace;
252 } else {
253 IDNS = Decl::IDNS_Tag;
254 }
255 break;
256
257 case Sema::LookupLabel:
258 IDNS = Decl::IDNS_Label;
259 break;
260
261 case Sema::LookupMemberName:
262 IDNS = Decl::IDNS_Member;
263 if (CPlusPlus)
264 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary;
265 break;
266
267 case Sema::LookupNestedNameSpecifierName:
268 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace;
269 break;
270
271 case Sema::LookupNamespaceName:
272 IDNS = Decl::IDNS_Namespace;
273 break;
274
275 case Sema::LookupUsingDeclName:
276 assert(Redeclaration && "should only be used for redecl lookup");
277 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member |
278 Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend |
279 Decl::IDNS_LocalExtern;
280 break;
281
282 case Sema::LookupObjCProtocolName:
283 IDNS = Decl::IDNS_ObjCProtocol;
284 break;
285
286 case Sema::LookupOMPReductionName:
287 IDNS = Decl::IDNS_OMPReduction;
288 break;
289
290 case Sema::LookupOMPMapperName:
291 IDNS = Decl::IDNS_OMPMapper;
292 break;
293
294 case Sema::LookupAnyName:
295 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member
296 | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol
297 | Decl::IDNS_Type;
298 break;
299 }
300 return IDNS;
301}
302
303void LookupResult::configure() {
304 IDNS = getIDNS(NameKind: LookupKind, CPlusPlus: getSema().getLangOpts().CPlusPlus,
305 Redeclaration: isForRedeclaration());
306
307 // If we're looking for one of the allocation or deallocation
308 // operators, make sure that the implicitly-declared new and delete
309 // operators can be found.
310 switch (NameInfo.getName().getCXXOverloadedOperator()) {
311 case OO_New:
312 case OO_Delete:
313 case OO_Array_New:
314 case OO_Array_Delete:
315 getSema().DeclareGlobalNewDelete();
316 break;
317
318 default:
319 break;
320 }
321
322 // Compiler builtins are always visible, regardless of where they end
323 // up being declared.
324 if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) {
325 if (unsigned BuiltinID = Id->getBuiltinID()) {
326 if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(ID: BuiltinID))
327 AllowHidden = true;
328 }
329 }
330}
331
332bool LookupResult::checkDebugAssumptions() const {
333 // This function is never called by NDEBUG builds.
334 assert(ResultKind != LookupResultKind::NotFound || Decls.size() == 0);
335 assert(ResultKind != LookupResultKind::Found || Decls.size() == 1);
336 assert(ResultKind != LookupResultKind::FoundOverloaded || Decls.size() > 1 ||
337 (Decls.size() == 1 &&
338 isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl())));
339 assert(ResultKind != LookupResultKind::FoundUnresolvedValue ||
340 checkUnresolved());
341 assert(ResultKind != LookupResultKind::Ambiguous || Decls.size() > 1 ||
342 (Decls.size() == 1 &&
343 (Ambiguity == LookupAmbiguityKind::AmbiguousBaseSubobjects ||
344 Ambiguity == LookupAmbiguityKind::AmbiguousBaseSubobjectTypes)));
345 assert((Paths != nullptr) ==
346 (ResultKind == LookupResultKind::Ambiguous &&
347 (Ambiguity == LookupAmbiguityKind::AmbiguousBaseSubobjectTypes ||
348 Ambiguity == LookupAmbiguityKind::AmbiguousBaseSubobjects)));
349 return true;
350}
351
352// Necessary because CXXBasePaths is not complete in Sema.h
353void LookupResult::deletePaths(CXXBasePaths *Paths) {
354 delete Paths;
355}
356
357/// Get a representative context for a declaration such that two declarations
358/// will have the same context if they were found within the same scope.
359static const DeclContext *getContextForScopeMatching(const Decl *D) {
360 // For function-local declarations, use that function as the context. This
361 // doesn't account for scopes within the function; the caller must deal with
362 // those.
363 if (const DeclContext *DC = D->getLexicalDeclContext();
364 DC->isFunctionOrMethod())
365 return DC;
366
367 // Otherwise, look at the semantic context of the declaration. The
368 // declaration must have been found there.
369 return D->getDeclContext()->getRedeclContext();
370}
371
372/// Determine whether \p D is a better lookup result than \p Existing,
373/// given that they declare the same entity.
374static bool isPreferredLookupResult(Sema &S, Sema::LookupNameKind Kind,
375 const NamedDecl *D,
376 const NamedDecl *Existing) {
377 // When looking up redeclarations of a using declaration, prefer a using
378 // shadow declaration over any other declaration of the same entity.
379 if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(Val: D) &&
380 !isa<UsingShadowDecl>(Val: Existing))
381 return true;
382
383 const auto *DUnderlying = D->getUnderlyingDecl();
384 const auto *EUnderlying = Existing->getUnderlyingDecl();
385
386 // If they have different underlying declarations, prefer a typedef over the
387 // original type (this happens when two type declarations denote the same
388 // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef
389 // might carry additional semantic information, such as an alignment override.
390 // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag
391 // declaration over a typedef. Also prefer a tag over a typedef for
392 // destructor name lookup because in some contexts we only accept a
393 // class-name in a destructor declaration.
394 if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) {
395 assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying));
396 bool HaveTag = isa<TagDecl>(Val: EUnderlying);
397 bool WantTag =
398 Kind == Sema::LookupTagName || Kind == Sema::LookupDestructorName;
399 return HaveTag != WantTag;
400 }
401
402 // Pick the function with more default arguments.
403 // FIXME: In the presence of ambiguous default arguments, we should keep both,
404 // so we can diagnose the ambiguity if the default argument is needed.
405 // See C++ [over.match.best]p3.
406 if (const auto *DFD = dyn_cast<FunctionDecl>(Val: DUnderlying)) {
407 const auto *EFD = cast<FunctionDecl>(Val: EUnderlying);
408 unsigned DMin = DFD->getMinRequiredArguments();
409 unsigned EMin = EFD->getMinRequiredArguments();
410 // If D has more default arguments, it is preferred.
411 if (DMin != EMin)
412 return DMin < EMin;
413 // FIXME: When we track visibility for default function arguments, check
414 // that we pick the declaration with more visible default arguments.
415 }
416
417 // Pick the template with more default template arguments.
418 if (const auto *DTD = dyn_cast<TemplateDecl>(Val: DUnderlying)) {
419 const auto *ETD = cast<TemplateDecl>(Val: EUnderlying);
420 unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments();
421 unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments();
422 // If D has more default arguments, it is preferred. Note that default
423 // arguments (and their visibility) is monotonically increasing across the
424 // redeclaration chain, so this is a quick proxy for "is more recent".
425 if (DMin != EMin)
426 return DMin < EMin;
427 // If D has more *visible* default arguments, it is preferred. Note, an
428 // earlier default argument being visible does not imply that a later
429 // default argument is visible, so we can't just check the first one.
430 for (unsigned I = DMin, N = DTD->getTemplateParameters()->size();
431 I != N; ++I) {
432 if (!S.hasVisibleDefaultArgument(
433 D: ETD->getTemplateParameters()->getParam(Idx: I)) &&
434 S.hasVisibleDefaultArgument(
435 D: DTD->getTemplateParameters()->getParam(Idx: I)))
436 return true;
437 }
438 }
439
440 // VarDecl can have incomplete array types, prefer the one with more complete
441 // array type.
442 if (const auto *DVD = dyn_cast<VarDecl>(Val: DUnderlying)) {
443 const auto *EVD = cast<VarDecl>(Val: EUnderlying);
444 if (EVD->getType()->isIncompleteType() &&
445 !DVD->getType()->isIncompleteType()) {
446 // Prefer the decl with a more complete type if visible.
447 return S.isVisible(D: DVD);
448 }
449 return false; // Avoid picking up a newer decl, just because it was newer.
450 }
451
452 // For most kinds of declaration, it doesn't really matter which one we pick.
453 if (!isa<FunctionDecl>(Val: DUnderlying) && !isa<VarDecl>(Val: DUnderlying)) {
454 // If the existing declaration is hidden, prefer the new one. Otherwise,
455 // keep what we've got.
456 return !S.isVisible(D: Existing);
457 }
458
459 // Pick the newer declaration; it might have a more precise type.
460 for (const Decl *Prev = DUnderlying->getPreviousDecl(); Prev;
461 Prev = Prev->getPreviousDecl())
462 if (Prev == EUnderlying)
463 return true;
464 return false;
465}
466
467/// Determine whether \p D can hide a tag declaration.
468static bool canHideTag(const NamedDecl *D) {
469 // C++ [basic.scope.declarative]p4:
470 // Given a set of declarations in a single declarative region [...]
471 // exactly one declaration shall declare a class name or enumeration name
472 // that is not a typedef name and the other declarations shall all refer to
473 // the same variable, non-static data member, or enumerator, or all refer
474 // to functions and function templates; in this case the class name or
475 // enumeration name is hidden.
476 // C++ [basic.scope.hiding]p2:
477 // A class name or enumeration name can be hidden by the name of a
478 // variable, data member, function, or enumerator declared in the same
479 // scope.
480 // An UnresolvedUsingValueDecl always instantiates to one of these.
481 D = D->getUnderlyingDecl();
482 return isa<VarDecl>(Val: D) || isa<EnumConstantDecl>(Val: D) || isa<FunctionDecl>(Val: D) ||
483 isa<FunctionTemplateDecl>(Val: D) || isa<FieldDecl>(Val: D) ||
484 isa<UnresolvedUsingValueDecl>(Val: D);
485}
486
487/// Resolves the result kind of this lookup.
488void LookupResult::resolveKind() {
489 unsigned N = Decls.size();
490
491 // Fast case: no possible ambiguity.
492 if (N == 0) {
493 assert(ResultKind == LookupResultKind::NotFound ||
494 ResultKind == LookupResultKind::NotFoundInCurrentInstantiation);
495 return;
496 }
497
498 // If there's a single decl, we need to examine it to decide what
499 // kind of lookup this is.
500 if (N == 1) {
501 const NamedDecl *D = (*Decls.begin())->getUnderlyingDecl();
502 if (isa<FunctionTemplateDecl>(Val: D))
503 ResultKind = LookupResultKind::FoundOverloaded;
504 else if (isa<UnresolvedUsingValueDecl>(Val: D))
505 ResultKind = LookupResultKind::FoundUnresolvedValue;
506 return;
507 }
508
509 // Don't do any extra resolution if we've already resolved as ambiguous.
510 if (ResultKind == LookupResultKind::Ambiguous)
511 return;
512
513 llvm::SmallDenseMap<const NamedDecl *, unsigned, 16> Unique;
514 llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes;
515
516 bool Ambiguous = false;
517 bool ReferenceToPlaceHolderVariable = false;
518 bool HasTag = false, HasFunction = false;
519 bool HasFunctionTemplate = false, HasUnresolved = false;
520 const NamedDecl *HasNonFunction = nullptr;
521
522 llvm::SmallVector<const NamedDecl *, 4> EquivalentNonFunctions;
523 llvm::BitVector RemovedDecls(N);
524
525 for (unsigned I = 0; I < N; I++) {
526 const NamedDecl *D = Decls[I]->getUnderlyingDecl();
527 D = cast<NamedDecl>(Val: D->getCanonicalDecl());
528
529 // Ignore an invalid declaration unless it's the only one left.
530 // Also ignore HLSLBufferDecl which not have name conflict with other Decls.
531 if ((D->isInvalidDecl() || isa<HLSLBufferDecl>(Val: D)) &&
532 N - RemovedDecls.count() > 1) {
533 RemovedDecls.set(I);
534 continue;
535 }
536
537 // C++ [basic.scope.hiding]p2:
538 // A class name or enumeration name can be hidden by the name of
539 // an object, function, or enumerator declared in the same
540 // scope. If a class or enumeration name and an object, function,
541 // or enumerator are declared in the same scope (in any order)
542 // with the same name, the class or enumeration name is hidden
543 // wherever the object, function, or enumerator name is visible.
544 if (HideTags && isa<TagDecl>(Val: D)) {
545 bool Hidden = false;
546 for (auto *OtherDecl : Decls) {
547 if (canHideTag(D: OtherDecl) && !OtherDecl->isInvalidDecl() &&
548 getContextForScopeMatching(D: OtherDecl)->Equals(
549 DC: getContextForScopeMatching(D: Decls[I]))) {
550 RemovedDecls.set(I);
551 Hidden = true;
552 break;
553 }
554 }
555 if (Hidden)
556 continue;
557 }
558
559 std::optional<unsigned> ExistingI;
560
561 // Redeclarations of types via typedef can occur both within a scope
562 // and, through using declarations and directives, across scopes. There is
563 // no ambiguity if they all refer to the same type, so unique based on the
564 // canonical type.
565 if (const auto *TD = dyn_cast<TypeDecl>(Val: D)) {
566 auto UniqueResult = UniqueTypes.insert(
567 KV: std::make_pair(x: getSema().Context.getCanonicalTypeDeclType(TD), y&: I));
568 if (!UniqueResult.second) {
569 // The type is not unique.
570 ExistingI = UniqueResult.first->second;
571 }
572 }
573
574 // For non-type declarations, check for a prior lookup result naming this
575 // canonical declaration.
576 if (!ExistingI) {
577 auto UniqueResult = Unique.insert(KV: std::make_pair(x&: D, y&: I));
578 if (!UniqueResult.second) {
579 // We've seen this entity before.
580 ExistingI = UniqueResult.first->second;
581 }
582 }
583
584 if (ExistingI) {
585 // This is not a unique lookup result. Pick one of the results and
586 // discard the other.
587 if (isPreferredLookupResult(S&: getSema(), Kind: getLookupKind(), D: Decls[I],
588 Existing: Decls[*ExistingI]))
589 Decls[*ExistingI] = Decls[I];
590 RemovedDecls.set(I);
591 continue;
592 }
593
594 // Otherwise, do some decl type analysis and then continue.
595
596 if (isa<UnresolvedUsingValueDecl>(Val: D)) {
597 HasUnresolved = true;
598 } else if (isa<TagDecl>(Val: D)) {
599 if (HasTag)
600 Ambiguous = true;
601 HasTag = true;
602 } else if (isa<FunctionTemplateDecl>(Val: D)) {
603 HasFunction = true;
604 HasFunctionTemplate = true;
605 } else if (isa<FunctionDecl>(Val: D)) {
606 HasFunction = true;
607 } else {
608 if (HasNonFunction) {
609 // If we're about to create an ambiguity between two declarations that
610 // are equivalent, but one is an internal linkage declaration from one
611 // module and the other is an internal linkage declaration from another
612 // module, just skip it.
613 if (getSema().isEquivalentInternalLinkageDeclaration(A: HasNonFunction,
614 B: D)) {
615 EquivalentNonFunctions.push_back(Elt: D);
616 RemovedDecls.set(I);
617 continue;
618 }
619 if (D->isPlaceholderVar(LangOpts: getSema().getLangOpts()) &&
620 getContextForScopeMatching(D) ==
621 getContextForScopeMatching(D: Decls[I])) {
622 ReferenceToPlaceHolderVariable = true;
623 }
624 Ambiguous = true;
625 }
626 HasNonFunction = D;
627 }
628 }
629
630 // FIXME: This diagnostic should really be delayed until we're done with
631 // the lookup result, in case the ambiguity is resolved by the caller.
632 if (!EquivalentNonFunctions.empty() && !Ambiguous)
633 getSema().diagnoseEquivalentInternalLinkageDeclarations(
634 Loc: getNameLoc(), D: HasNonFunction, Equiv: EquivalentNonFunctions);
635
636 // Remove decls by replacing them with decls from the end (which
637 // means that we need to iterate from the end) and then truncating
638 // to the new size.
639 for (int I = RemovedDecls.find_last(); I >= 0; I = RemovedDecls.find_prev(PriorTo: I))
640 Decls[I] = Decls[--N];
641 Decls.truncate(N);
642
643 if ((HasNonFunction && (HasFunction || HasUnresolved)) ||
644 (HideTags && HasTag && (HasFunction || HasNonFunction || HasUnresolved)))
645 Ambiguous = true;
646
647 if (Ambiguous && ReferenceToPlaceHolderVariable)
648 setAmbiguous(LookupAmbiguityKind::AmbiguousReferenceToPlaceholderVariable);
649 else if (Ambiguous)
650 setAmbiguous(LookupAmbiguityKind::AmbiguousReference);
651 else if (HasUnresolved)
652 ResultKind = LookupResultKind::FoundUnresolvedValue;
653 else if (N > 1 || HasFunctionTemplate)
654 ResultKind = LookupResultKind::FoundOverloaded;
655 else
656 ResultKind = LookupResultKind::Found;
657}
658
659void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
660 CXXBasePaths::const_paths_iterator I, E;
661 for (I = P.begin(), E = P.end(); I != E; ++I)
662 for (DeclContext::lookup_iterator DI = I->Decls, DE = DI.end(); DI != DE;
663 ++DI)
664 addDecl(D: *DI);
665}
666
667void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) {
668 Paths = new CXXBasePaths;
669 Paths->swap(Other&: P);
670 addDeclsFromBasePaths(P: *Paths);
671 resolveKind();
672 setAmbiguous(LookupAmbiguityKind::AmbiguousBaseSubobjects);
673}
674
675void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) {
676 Paths = new CXXBasePaths;
677 Paths->swap(Other&: P);
678 addDeclsFromBasePaths(P: *Paths);
679 resolveKind();
680 setAmbiguous(LookupAmbiguityKind::AmbiguousBaseSubobjectTypes);
681}
682
683void LookupResult::print(raw_ostream &Out) {
684 Out << Decls.size() << " result(s)";
685 if (isAmbiguous()) Out << ", ambiguous";
686 if (Paths) Out << ", base paths present";
687
688 for (iterator I = begin(), E = end(); I != E; ++I) {
689 Out << "\n";
690 (*I)->print(Out, Indentation: 2);
691 }
692}
693
694LLVM_DUMP_METHOD void LookupResult::dump() {
695 llvm::errs() << "lookup results for " << getLookupName().getAsString()
696 << ":\n";
697 for (NamedDecl *D : *this)
698 D->dump();
699}
700
701/// Diagnose a missing builtin type.
702static QualType diagOpenCLBuiltinTypeError(Sema &S, llvm::StringRef TypeClass,
703 llvm::StringRef Name) {
704 S.Diag(Loc: SourceLocation(), DiagID: diag::err_opencl_type_not_found)
705 << TypeClass << Name;
706 return S.Context.VoidTy;
707}
708
709/// Lookup an OpenCL enum type.
710static QualType getOpenCLEnumType(Sema &S, llvm::StringRef Name) {
711 LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(),
712 Sema::LookupTagName);
713 S.LookupName(R&: Result, S: S.TUScope);
714 if (Result.empty())
715 return diagOpenCLBuiltinTypeError(S, TypeClass: "enum", Name);
716 EnumDecl *Decl = Result.getAsSingle<EnumDecl>();
717 if (!Decl)
718 return diagOpenCLBuiltinTypeError(S, TypeClass: "enum", Name);
719 return S.Context.getCanonicalTagType(TD: Decl);
720}
721
722/// Lookup an OpenCL typedef type.
723static QualType getOpenCLTypedefType(Sema &S, llvm::StringRef Name) {
724 LookupResult Result(S, &S.Context.Idents.get(Name), SourceLocation(),
725 Sema::LookupOrdinaryName);
726 S.LookupName(R&: Result, S: S.TUScope);
727 if (Result.empty())
728 return diagOpenCLBuiltinTypeError(S, TypeClass: "typedef", Name);
729 TypedefNameDecl *Decl = Result.getAsSingle<TypedefNameDecl>();
730 if (!Decl)
731 return diagOpenCLBuiltinTypeError(S, TypeClass: "typedef", Name);
732 return S.Context.getTypedefType(Keyword: ElaboratedTypeKeyword::None,
733 /*Qualifier=*/std::nullopt, Decl);
734}
735
736/// Get the QualType instances of the return type and arguments for an OpenCL
737/// builtin function signature.
738/// \param S (in) The Sema instance.
739/// \param OpenCLBuiltin (in) The signature currently handled.
740/// \param GenTypeMaxCnt (out) Maximum number of types contained in a generic
741/// type used as return type or as argument.
742/// Only meaningful for generic types, otherwise equals 1.
743/// \param RetTypes (out) List of the possible return types.
744/// \param ArgTypes (out) List of the possible argument types. For each
745/// argument, ArgTypes contains QualTypes for the Cartesian product
746/// of (vector sizes) x (types) .
747static void GetQualTypesForOpenCLBuiltin(
748 Sema &S, const OpenCLBuiltinStruct &OpenCLBuiltin, unsigned &GenTypeMaxCnt,
749 SmallVector<QualType, 1> &RetTypes,
750 SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) {
751 // Get the QualType instances of the return types.
752 unsigned Sig = SignatureTable[OpenCLBuiltin.SigTableIndex];
753 OCL2Qual(S, Ty: TypeTable[Sig], QT&: RetTypes);
754 GenTypeMaxCnt = RetTypes.size();
755
756 // Get the QualType instances of the arguments.
757 // First type is the return type, skip it.
758 for (unsigned Index = 1; Index < OpenCLBuiltin.NumTypes; Index++) {
759 SmallVector<QualType, 1> Ty;
760 OCL2Qual(S, Ty: TypeTable[SignatureTable[OpenCLBuiltin.SigTableIndex + Index]],
761 QT&: Ty);
762 GenTypeMaxCnt = (Ty.size() > GenTypeMaxCnt) ? Ty.size() : GenTypeMaxCnt;
763 ArgTypes.push_back(Elt: std::move(Ty));
764 }
765}
766
767/// Create a list of the candidate function overloads for an OpenCL builtin
768/// function.
769/// \param Context (in) The ASTContext instance.
770/// \param GenTypeMaxCnt (in) Maximum number of types contained in a generic
771/// type used as return type or as argument.
772/// Only meaningful for generic types, otherwise equals 1.
773/// \param FunctionList (out) List of FunctionTypes.
774/// \param RetTypes (in) List of the possible return types.
775/// \param ArgTypes (in) List of the possible types for the arguments.
776static void GetOpenCLBuiltinFctOverloads(
777 ASTContext &Context, unsigned GenTypeMaxCnt,
778 std::vector<QualType> &FunctionList, SmallVector<QualType, 1> &RetTypes,
779 SmallVector<SmallVector<QualType, 1>, 5> &ArgTypes) {
780 FunctionProtoType::ExtProtoInfo PI(
781 Context.getTargetInfo().getDefaultCallingConv());
782 PI.Variadic = false;
783
784 // Do not attempt to create any FunctionTypes if there are no return types,
785 // which happens when a type belongs to a disabled extension.
786 if (RetTypes.size() == 0)
787 return;
788
789 // Create FunctionTypes for each (gen)type.
790 for (unsigned IGenType = 0; IGenType < GenTypeMaxCnt; IGenType++) {
791 SmallVector<QualType, 5> ArgList;
792
793 for (unsigned A = 0; A < ArgTypes.size(); A++) {
794 // Bail out if there is an argument that has no available types.
795 if (ArgTypes[A].size() == 0)
796 return;
797
798 // Builtins such as "max" have an "sgentype" argument that represents
799 // the corresponding scalar type of a gentype. The number of gentypes
800 // must be a multiple of the number of sgentypes.
801 assert(GenTypeMaxCnt % ArgTypes[A].size() == 0 &&
802 "argument type count not compatible with gentype type count");
803 unsigned Idx = IGenType % ArgTypes[A].size();
804 ArgList.push_back(Elt: ArgTypes[A][Idx]);
805 }
806
807 FunctionList.push_back(x: Context.getFunctionType(
808 ResultTy: RetTypes[(RetTypes.size() != 1) ? IGenType : 0], Args: ArgList, EPI: PI));
809 }
810}
811
812/// When trying to resolve a function name, if isOpenCLBuiltin() returns a
813/// non-null <Index, Len> pair, then the name is referencing an OpenCL
814/// builtin function. Add all candidate signatures to the LookUpResult.
815///
816/// \param S (in) The Sema instance.
817/// \param LR (inout) The LookupResult instance.
818/// \param II (in) The identifier being resolved.
819/// \param FctIndex (in) Starting index in the BuiltinTable.
820/// \param Len (in) The signature list has Len elements.
821static void InsertOCLBuiltinDeclarationsFromTable(Sema &S, LookupResult &LR,
822 IdentifierInfo *II,
823 const unsigned FctIndex,
824 const unsigned Len) {
825 // The builtin function declaration uses generic types (gentype).
826 bool HasGenType = false;
827
828 // Maximum number of types contained in a generic type used as return type or
829 // as argument. Only meaningful for generic types, otherwise equals 1.
830 unsigned GenTypeMaxCnt;
831
832 ASTContext &Context = S.Context;
833
834 for (unsigned SignatureIndex = 0; SignatureIndex < Len; SignatureIndex++) {
835 const OpenCLBuiltinStruct &OpenCLBuiltin =
836 BuiltinTable[FctIndex + SignatureIndex];
837
838 // Ignore this builtin function if it is not available in the currently
839 // selected language version.
840 if (!isOpenCLVersionContainedInMask(LO: Context.getLangOpts(),
841 Mask: OpenCLBuiltin.Versions))
842 continue;
843
844 // Ignore this builtin function if it carries an extension macro that is
845 // not defined. This indicates that the extension is not supported by the
846 // target, so the builtin function should not be available.
847 StringRef Extensions = FunctionExtensionTable[OpenCLBuiltin.Extension];
848 if (!Extensions.empty()) {
849 SmallVector<StringRef, 2> ExtVec;
850 Extensions.split(A&: ExtVec, Separator: " ");
851 bool AllExtensionsDefined = true;
852 for (StringRef Ext : ExtVec) {
853 if (!S.getPreprocessor().isMacroDefined(Id: Ext)) {
854 AllExtensionsDefined = false;
855 break;
856 }
857 }
858 if (!AllExtensionsDefined)
859 continue;
860 }
861
862 SmallVector<QualType, 1> RetTypes;
863 SmallVector<SmallVector<QualType, 1>, 5> ArgTypes;
864
865 // Obtain QualType lists for the function signature.
866 GetQualTypesForOpenCLBuiltin(S, OpenCLBuiltin, GenTypeMaxCnt, RetTypes,
867 ArgTypes);
868 if (GenTypeMaxCnt > 1) {
869 HasGenType = true;
870 }
871
872 // Create function overload for each type combination.
873 std::vector<QualType> FunctionList;
874 GetOpenCLBuiltinFctOverloads(Context, GenTypeMaxCnt, FunctionList, RetTypes,
875 ArgTypes);
876
877 SourceLocation Loc = LR.getNameLoc();
878 DeclContext *Parent = Context.getTranslationUnitDecl();
879 FunctionDecl *NewOpenCLBuiltin;
880
881 for (const auto &FTy : FunctionList) {
882 NewOpenCLBuiltin = FunctionDecl::Create(
883 C&: Context, DC: Parent, StartLoc: Loc, NLoc: Loc, N: II, T: FTy, /*TInfo=*/nullptr, SC: SC_Extern,
884 UsesFPIntrin: S.getCurFPFeatures().isFPConstrained(), isInlineSpecified: false,
885 hasWrittenPrototype: FTy->isFunctionProtoType());
886 NewOpenCLBuiltin->setImplicit();
887
888 // Create Decl objects for each parameter, adding them to the
889 // FunctionDecl.
890 const auto *FP = cast<FunctionProtoType>(Val: FTy);
891 SmallVector<ParmVarDecl *, 4> ParmList;
892 for (unsigned IParm = 0, e = FP->getNumParams(); IParm != e; ++IParm) {
893 ParmVarDecl *Parm = ParmVarDecl::Create(
894 C&: Context, DC: NewOpenCLBuiltin, StartLoc: SourceLocation(), IdLoc: SourceLocation(),
895 Id: nullptr, T: FP->getParamType(i: IParm), TInfo: nullptr, S: SC_None, DefArg: nullptr);
896 Parm->setScopeInfo(scopeDepth: 0, parameterIndex: IParm);
897 ParmList.push_back(Elt: Parm);
898 }
899 NewOpenCLBuiltin->setParams(ParmList);
900
901 // Add function attributes.
902 if (OpenCLBuiltin.IsPure)
903 NewOpenCLBuiltin->addAttr(A: PureAttr::CreateImplicit(Ctx&: Context));
904 if (OpenCLBuiltin.IsConst)
905 NewOpenCLBuiltin->addAttr(A: ConstAttr::CreateImplicit(Ctx&: Context));
906 if (OpenCLBuiltin.IsConv)
907 NewOpenCLBuiltin->addAttr(A: ConvergentAttr::CreateImplicit(Ctx&: Context));
908
909 if (!S.getLangOpts().OpenCLCPlusPlus)
910 NewOpenCLBuiltin->addAttr(A: OverloadableAttr::CreateImplicit(Ctx&: Context));
911
912 LR.addDecl(D: NewOpenCLBuiltin);
913 }
914 }
915
916 // If we added overloads, need to resolve the lookup result.
917 if (Len > 1 || HasGenType)
918 LR.resolveKind();
919}
920
921bool Sema::LookupBuiltin(LookupResult &R) {
922 Sema::LookupNameKind NameKind = R.getLookupKind();
923
924 // If we didn't find a use of this identifier, and if the identifier
925 // corresponds to a compiler builtin, create the decl object for the builtin
926 // now, injecting it into translation unit scope, and return it.
927 if (NameKind == Sema::LookupOrdinaryName ||
928 NameKind == Sema::LookupRedeclarationWithLinkage) {
929 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo();
930 if (II) {
931 if (NameKind == Sema::LookupOrdinaryName) {
932 if (getLangOpts().CPlusPlus) {
933#define BuiltinTemplate(BIName)
934#define CPlusPlusBuiltinTemplate(BIName) \
935 if (II == getASTContext().get##BIName##Name()) { \
936 R.addDecl(getASTContext().get##BIName##Decl()); \
937 return true; \
938 }
939#include "clang/Basic/BuiltinTemplates.inc"
940 }
941 if (getLangOpts().HLSL) {
942#define BuiltinTemplate(BIName)
943#define HLSLBuiltinTemplate(BIName) \
944 if (II == getASTContext().get##BIName##Name()) { \
945 R.addDecl(getASTContext().get##BIName##Decl()); \
946 return true; \
947 }
948#include "clang/Basic/BuiltinTemplates.inc"
949 }
950 }
951
952 // Check if this is an OpenCL Builtin, and if so, insert its overloads.
953 if (getLangOpts().OpenCL && getLangOpts().DeclareOpenCLBuiltins) {
954 auto Index = isOpenCLBuiltin(Name: II->getName());
955 if (Index.first) {
956 InsertOCLBuiltinDeclarationsFromTable(S&: *this, LR&: R, II, FctIndex: Index.first - 1,
957 Len: Index.second);
958 return true;
959 }
960 }
961
962 if (RISCV().DeclareRVVBuiltins || RISCV().DeclareSiFiveVectorBuiltins ||
963 RISCV().DeclareAndesVectorBuiltins) {
964 if (!RISCV().IntrinsicManager)
965 RISCV().IntrinsicManager = CreateRISCVIntrinsicManager(S&: *this);
966
967 RISCV().IntrinsicManager->InitIntrinsicList();
968
969 if (RISCV().IntrinsicManager->CreateIntrinsicIfFound(LR&: R, II, PP))
970 return true;
971 }
972
973 // If this is a builtin on this (or all) targets, create the decl.
974 if (unsigned BuiltinID = II->getBuiltinID()) {
975 // In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined
976 // library functions like 'malloc'. Instead, we'll just error.
977 if ((getLangOpts().CPlusPlus || getLangOpts().OpenCL) &&
978 Context.BuiltinInfo.isPredefinedLibFunction(ID: BuiltinID))
979 return false;
980
981 if (NamedDecl *D =
982 LazilyCreateBuiltin(II, ID: BuiltinID, S: TUScope,
983 ForRedeclaration: R.isForRedeclaration(), Loc: R.getNameLoc())) {
984 R.addDecl(D);
985 return true;
986 }
987 }
988 }
989 }
990
991 return false;
992}
993
994/// Looks up the declaration of "struct objc_super" and
995/// saves it for later use in building builtin declaration of
996/// objc_msgSendSuper and objc_msgSendSuper_stret.
997static void LookupPredefedObjCSuperType(Sema &Sema, Scope *S) {
998 ASTContext &Context = Sema.Context;
999 LookupResult Result(Sema, &Context.Idents.get(Name: "objc_super"), SourceLocation(),
1000 Sema::LookupTagName);
1001 Sema.LookupName(R&: Result, S);
1002 if (Result.getResultKind() == LookupResultKind::Found)
1003 if (const TagDecl *TD = Result.getAsSingle<TagDecl>())
1004 Context.setObjCSuperType(Context.getCanonicalTagType(TD));
1005}
1006
1007void Sema::LookupNecessaryTypesForBuiltin(Scope *S, unsigned ID) {
1008 if (ID == Builtin::BIobjc_msgSendSuper)
1009 LookupPredefedObjCSuperType(Sema&: *this, S);
1010}
1011
1012/// Determine whether we can declare a special member function within
1013/// the class at this point.
1014static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) {
1015 // We need to have a definition for the class.
1016 if (!Class->getDefinition() || Class->isDependentContext())
1017 return false;
1018
1019 // We can't be in the middle of defining the class.
1020 return !Class->isBeingDefined();
1021}
1022
1023void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) {
1024 if (!CanDeclareSpecialMemberFunction(Class))
1025 return;
1026
1027 // If the default constructor has not yet been declared, do so now.
1028 if (Class->needsImplicitDefaultConstructor())
1029 DeclareImplicitDefaultConstructor(ClassDecl: Class);
1030
1031 // If the copy constructor has not yet been declared, do so now.
1032 if (Class->needsImplicitCopyConstructor())
1033 DeclareImplicitCopyConstructor(ClassDecl: Class);
1034
1035 // If the copy assignment operator has not yet been declared, do so now.
1036 if (Class->needsImplicitCopyAssignment())
1037 DeclareImplicitCopyAssignment(ClassDecl: Class);
1038
1039 if (getLangOpts().CPlusPlus11) {
1040 // If the move constructor has not yet been declared, do so now.
1041 if (Class->needsImplicitMoveConstructor())
1042 DeclareImplicitMoveConstructor(ClassDecl: Class);
1043
1044 // If the move assignment operator has not yet been declared, do so now.
1045 if (Class->needsImplicitMoveAssignment())
1046 DeclareImplicitMoveAssignment(ClassDecl: Class);
1047 }
1048
1049 // If the destructor has not yet been declared, do so now.
1050 if (Class->needsImplicitDestructor())
1051 DeclareImplicitDestructor(ClassDecl: Class);
1052}
1053
1054/// Determine whether this is the name of an implicitly-declared
1055/// special member function.
1056static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) {
1057 switch (Name.getNameKind()) {
1058 case DeclarationName::CXXConstructorName:
1059 case DeclarationName::CXXDestructorName:
1060 return true;
1061
1062 case DeclarationName::CXXOperatorName:
1063 return Name.getCXXOverloadedOperator() == OO_Equal;
1064
1065 default:
1066 break;
1067 }
1068
1069 return false;
1070}
1071
1072/// If there are any implicit member functions with the given name
1073/// that need to be declared in the given declaration context, do so.
1074static void DeclareImplicitMemberFunctionsWithName(Sema &S,
1075 DeclarationName Name,
1076 SourceLocation Loc,
1077 const DeclContext *DC) {
1078 if (!DC)
1079 return;
1080
1081 switch (Name.getNameKind()) {
1082 case DeclarationName::CXXConstructorName:
1083 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Val: DC))
1084 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Class: Record)) {
1085 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
1086 if (Record->needsImplicitDefaultConstructor())
1087 S.DeclareImplicitDefaultConstructor(ClassDecl: Class);
1088 if (Record->needsImplicitCopyConstructor())
1089 S.DeclareImplicitCopyConstructor(ClassDecl: Class);
1090 if (S.getLangOpts().CPlusPlus11 &&
1091 Record->needsImplicitMoveConstructor())
1092 S.DeclareImplicitMoveConstructor(ClassDecl: Class);
1093 }
1094 break;
1095
1096 case DeclarationName::CXXDestructorName:
1097 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Val: DC))
1098 if (Record->getDefinition() && Record->needsImplicitDestructor() &&
1099 CanDeclareSpecialMemberFunction(Class: Record))
1100 S.DeclareImplicitDestructor(ClassDecl: const_cast<CXXRecordDecl *>(Record));
1101 break;
1102
1103 case DeclarationName::CXXOperatorName:
1104 if (Name.getCXXOverloadedOperator() != OO_Equal)
1105 break;
1106
1107 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Val: DC)) {
1108 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Class: Record)) {
1109 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
1110 if (Record->needsImplicitCopyAssignment())
1111 S.DeclareImplicitCopyAssignment(ClassDecl: Class);
1112 if (S.getLangOpts().CPlusPlus11 &&
1113 Record->needsImplicitMoveAssignment())
1114 S.DeclareImplicitMoveAssignment(ClassDecl: Class);
1115 }
1116 }
1117 break;
1118
1119 case DeclarationName::CXXDeductionGuideName:
1120 S.DeclareImplicitDeductionGuides(Template: Name.getCXXDeductionGuideTemplate(), Loc);
1121 break;
1122
1123 default:
1124 break;
1125 }
1126}
1127
1128// Adds all qualifying matches for a name within a decl context to the
1129// given lookup result. Returns true if any matches were found.
1130static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
1131 bool Found = false;
1132
1133 // Lazily declare C++ special member functions.
1134 if (S.getLangOpts().CPlusPlus)
1135 DeclareImplicitMemberFunctionsWithName(S, Name: R.getLookupName(), Loc: R.getNameLoc(),
1136 DC);
1137
1138 // Perform lookup into this declaration context.
1139 DeclContext::lookup_result DR = DC->lookup(Name: R.getLookupName());
1140 for (NamedDecl *D : DR) {
1141 if ((D = R.getAcceptableDecl(D))) {
1142 R.addDecl(D);
1143 Found = true;
1144 }
1145 }
1146
1147 if (!Found && DC->isTranslationUnit() && S.LookupBuiltin(R))
1148 return true;
1149
1150 if (R.getLookupName().getNameKind()
1151 != DeclarationName::CXXConversionFunctionName ||
1152 R.getLookupName().getCXXNameType()->isDependentType() ||
1153 !isa<CXXRecordDecl>(Val: DC))
1154 return Found;
1155
1156 // C++ [temp.mem]p6:
1157 // A specialization of a conversion function template is not found by
1158 // name lookup. Instead, any conversion function templates visible in the
1159 // context of the use are considered. [...]
1160 const CXXRecordDecl *Record = cast<CXXRecordDecl>(Val: DC);
1161 if (!Record->isCompleteDefinition())
1162 return Found;
1163
1164 // For conversion operators, 'operator auto' should only match
1165 // 'operator auto'. Since 'auto' is not a type, it shouldn't be considered
1166 // as a candidate for template substitution.
1167 auto *ContainedDeducedType =
1168 R.getLookupName().getCXXNameType()->getContainedDeducedType();
1169 if (R.getLookupName().getNameKind() ==
1170 DeclarationName::CXXConversionFunctionName &&
1171 ContainedDeducedType && ContainedDeducedType->isUndeducedType())
1172 return Found;
1173
1174 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(),
1175 UEnd = Record->conversion_end(); U != UEnd; ++U) {
1176 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(Val: *U);
1177 if (!ConvTemplate)
1178 continue;
1179
1180 // When we're performing lookup for the purposes of redeclaration, just
1181 // add the conversion function template. When we deduce template
1182 // arguments for specializations, we'll end up unifying the return
1183 // type of the new declaration with the type of the function template.
1184 if (R.isForRedeclaration()) {
1185 R.addDecl(D: ConvTemplate);
1186 Found = true;
1187 continue;
1188 }
1189
1190 // C++ [temp.mem]p6:
1191 // [...] For each such operator, if argument deduction succeeds
1192 // (14.9.2.3), the resulting specialization is used as if found by
1193 // name lookup.
1194 //
1195 // When referencing a conversion function for any purpose other than
1196 // a redeclaration (such that we'll be building an expression with the
1197 // result), perform template argument deduction and place the
1198 // specialization into the result set. We do this to avoid forcing all
1199 // callers to perform special deduction for conversion functions.
1200 TemplateDeductionInfo Info(R.getNameLoc());
1201 FunctionDecl *Specialization = nullptr;
1202
1203 const FunctionProtoType *ConvProto
1204 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
1205 assert(ConvProto && "Nonsensical conversion function template type");
1206
1207 // Compute the type of the function that we would expect the conversion
1208 // function to have, if it were to match the name given.
1209 // FIXME: Calling convention!
1210 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo();
1211 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(cc: CC_C);
1212 EPI.ExceptionSpec = EST_None;
1213 QualType ExpectedType = R.getSema().Context.getFunctionType(
1214 ResultTy: R.getLookupName().getCXXNameType(), Args: {}, EPI);
1215
1216 // Perform template argument deduction against the type that we would
1217 // expect the function to have.
1218 if (R.getSema().DeduceTemplateArguments(FunctionTemplate: ConvTemplate, ExplicitTemplateArgs: nullptr, ArgFunctionType: ExpectedType,
1219 Specialization, Info) ==
1220 TemplateDeductionResult::Success) {
1221 R.addDecl(D: Specialization);
1222 Found = true;
1223 }
1224 }
1225
1226 return Found;
1227}
1228
1229// Performs C++ unqualified lookup into the given file context.
1230static bool CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context,
1231 const DeclContext *NS,
1232 UnqualUsingDirectiveSet &UDirs) {
1233
1234 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
1235
1236 // Perform direct name lookup into the LookupCtx.
1237 bool Found = LookupDirect(S, R, DC: NS);
1238
1239 // Perform direct name lookup into the namespaces nominated by the
1240 // using directives whose common ancestor is this namespace.
1241 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(DC: NS))
1242 if (LookupDirect(S, R, DC: UUE.getNominatedNamespace()))
1243 Found = true;
1244
1245 R.resolveKind();
1246
1247 return Found;
1248}
1249
1250static bool isNamespaceOrTranslationUnitScope(Scope *S) {
1251 if (DeclContext *Ctx = S->getEntity())
1252 return Ctx->isFileContext();
1253 return false;
1254}
1255
1256/// Find the outer declaration context from this scope. This indicates the
1257/// context that we should search up to (exclusive) before considering the
1258/// parent of the specified scope.
1259static DeclContext *findOuterContext(Scope *S) {
1260 for (Scope *OuterS = S->getParent(); OuterS; OuterS = OuterS->getParent())
1261 if (DeclContext *DC = OuterS->getLookupEntity())
1262 return DC;
1263 return nullptr;
1264}
1265
1266namespace {
1267/// An RAII object to specify that we want to find block scope extern
1268/// declarations.
1269struct FindLocalExternScope {
1270 FindLocalExternScope(LookupResult &R)
1271 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
1272 Decl::IDNS_LocalExtern) {
1273 R.setFindLocalExtern(R.getIdentifierNamespace() &
1274 (Decl::IDNS_Ordinary | Decl::IDNS_NonMemberOperator));
1275 }
1276 void restore() {
1277 R.setFindLocalExtern(OldFindLocalExtern);
1278 }
1279 ~FindLocalExternScope() {
1280 restore();
1281 }
1282 LookupResult &R;
1283 bool OldFindLocalExtern;
1284};
1285} // end anonymous namespace
1286
1287bool Sema::CppLookupName(LookupResult &R, Scope *S) {
1288 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
1289
1290 DeclarationName Name = R.getLookupName();
1291 Sema::LookupNameKind NameKind = R.getLookupKind();
1292
1293 // If this is the name of an implicitly-declared special member function,
1294 // go through the scope stack to implicitly declare
1295 if (isImplicitlyDeclaredMemberFunctionName(Name)) {
1296 for (Scope *PreS = S; PreS; PreS = PreS->getParent())
1297 if (DeclContext *DC = PreS->getEntity())
1298 DeclareImplicitMemberFunctionsWithName(S&: *this, Name, Loc: R.getNameLoc(), DC);
1299 }
1300
1301 // C++23 [temp.dep.general]p2:
1302 // The component name of an unqualified-id is dependent if
1303 // - it is a conversion-function-id whose conversion-type-id
1304 // is dependent, or
1305 // - it is operator= and the current class is a templated entity, or
1306 // - the unqualified-id is the postfix-expression in a dependent call.
1307 if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName &&
1308 Name.getCXXNameType()->isDependentType()) {
1309 R.setNotFoundInCurrentInstantiation();
1310 return false;
1311 }
1312
1313 // Implicitly declare member functions with the name we're looking for, if in
1314 // fact we are in a scope where it matters.
1315
1316 Scope *Initial = S;
1317 IdentifierResolver::iterator
1318 I = IdResolver.begin(Name),
1319 IEnd = IdResolver.end();
1320
1321 // First we lookup local scope.
1322 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
1323 // ...During unqualified name lookup (3.4.1), the names appear as if
1324 // they were declared in the nearest enclosing namespace which contains
1325 // both the using-directive and the nominated namespace.
1326 // [Note: in this context, "contains" means "contains directly or
1327 // indirectly".
1328 //
1329 // For example:
1330 // namespace A { int i; }
1331 // void foo() {
1332 // int i;
1333 // {
1334 // using namespace A;
1335 // ++i; // finds local 'i', A::i appears at global scope
1336 // }
1337 // }
1338 //
1339 UnqualUsingDirectiveSet UDirs(*this);
1340 bool VisitedUsingDirectives = false;
1341 bool LeftStartingScope = false;
1342
1343 // When performing a scope lookup, we want to find local extern decls.
1344 FindLocalExternScope FindLocals(R);
1345
1346 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
1347 bool SearchNamespaceScope = true;
1348 // Check whether the IdResolver has anything in this scope.
1349 for (; I != IEnd && S->isDeclScope(D: *I); ++I) {
1350 if (NamedDecl *ND = R.getAcceptableDecl(D: *I)) {
1351 if (NameKind == LookupRedeclarationWithLinkage &&
1352 !(*I)->isTemplateParameter()) {
1353 // If it's a template parameter, we still find it, so we can diagnose
1354 // the invalid redeclaration.
1355
1356 // Determine whether this (or a previous) declaration is
1357 // out-of-scope.
1358 if (!LeftStartingScope && !Initial->isDeclScope(D: *I))
1359 LeftStartingScope = true;
1360
1361 // If we found something outside of our starting scope that
1362 // does not have linkage, skip it.
1363 if (LeftStartingScope && !((*I)->hasLinkage())) {
1364 R.setShadowed();
1365 continue;
1366 }
1367 } else {
1368 // We found something in this scope, we should not look at the
1369 // namespace scope
1370 SearchNamespaceScope = false;
1371 }
1372 R.addDecl(D: ND);
1373 }
1374 }
1375 if (!SearchNamespaceScope) {
1376 R.resolveKind();
1377 if (S->isClassScope())
1378 if (auto *Record = dyn_cast_if_present<CXXRecordDecl>(Val: S->getEntity()))
1379 R.setNamingClass(Record);
1380 return true;
1381 }
1382
1383 if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
1384 // C++11 [class.friend]p11:
1385 // If a friend declaration appears in a local class and the name
1386 // specified is an unqualified name, a prior declaration is
1387 // looked up without considering scopes that are outside the
1388 // innermost enclosing non-class scope.
1389 return false;
1390 }
1391
1392 if (DeclContext *Ctx = S->getLookupEntity()) {
1393 DeclContext *OuterCtx = findOuterContext(S);
1394 for (; Ctx && !Ctx->Equals(DC: OuterCtx); Ctx = Ctx->getLookupParent()) {
1395 // We do not directly look into transparent contexts, since
1396 // those entities will be found in the nearest enclosing
1397 // non-transparent context.
1398 if (Ctx->isTransparentContext())
1399 continue;
1400
1401 // We do not look directly into function or method contexts,
1402 // since all of the local variables and parameters of the
1403 // function/method are present within the Scope.
1404 if (Ctx->isFunctionOrMethod()) {
1405 // If we have an Objective-C instance method, look for ivars
1406 // in the corresponding interface.
1407 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Val: Ctx)) {
1408 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
1409 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
1410 ObjCInterfaceDecl *ClassDeclared;
1411 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
1412 IVarName: Name.getAsIdentifierInfo(),
1413 ClassDeclared)) {
1414 if (NamedDecl *ND = R.getAcceptableDecl(D: Ivar)) {
1415 R.addDecl(D: ND);
1416 R.resolveKind();
1417 return true;
1418 }
1419 }
1420 }
1421 }
1422
1423 continue;
1424 }
1425
1426 // If this is a file context, we need to perform unqualified name
1427 // lookup considering using directives.
1428 if (Ctx->isFileContext()) {
1429 // If we haven't handled using directives yet, do so now.
1430 if (!VisitedUsingDirectives) {
1431 // Add using directives from this context up to the top level.
1432 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
1433 if (UCtx->isTransparentContext())
1434 continue;
1435
1436 UDirs.visit(DC: UCtx, EffectiveDC: UCtx);
1437 }
1438
1439 // Find the innermost file scope, so we can add using directives
1440 // from local scopes.
1441 Scope *InnermostFileScope = S;
1442 while (InnermostFileScope &&
1443 !isNamespaceOrTranslationUnitScope(S: InnermostFileScope))
1444 InnermostFileScope = InnermostFileScope->getParent();
1445 UDirs.visitScopeChain(S: Initial, InnermostFileScope);
1446
1447 UDirs.done();
1448
1449 VisitedUsingDirectives = true;
1450 }
1451
1452 if (CppNamespaceLookup(S&: *this, R, Context, NS: Ctx, UDirs)) {
1453 R.resolveKind();
1454 return true;
1455 }
1456
1457 continue;
1458 }
1459
1460 // Perform qualified name lookup into this context.
1461 // FIXME: In some cases, we know that every name that could be found by
1462 // this qualified name lookup will also be on the identifier chain. For
1463 // example, inside a class without any base classes, we never need to
1464 // perform qualified lookup because all of the members are on top of the
1465 // identifier chain.
1466 if (LookupQualifiedName(R, LookupCtx: Ctx, /*InUnqualifiedLookup=*/true))
1467 return true;
1468 }
1469 }
1470 }
1471
1472 // Stop if we ran out of scopes.
1473 // FIXME: This really, really shouldn't be happening.
1474 if (!S) return false;
1475
1476 // If we are looking for members, no need to look into global/namespace scope.
1477 if (NameKind == LookupMemberName)
1478 return false;
1479
1480 // Collect UsingDirectiveDecls in all scopes, and recursively all
1481 // nominated namespaces by those using-directives.
1482 //
1483 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
1484 // don't build it for each lookup!
1485 if (!VisitedUsingDirectives) {
1486 UDirs.visitScopeChain(S: Initial, InnermostFileScope: S);
1487 UDirs.done();
1488 }
1489
1490 // If we're not performing redeclaration lookup, do not look for local
1491 // extern declarations outside of a function scope.
1492 if (!R.isForRedeclaration())
1493 FindLocals.restore();
1494
1495 // Lookup namespace scope, and global scope.
1496 // Unqualified name lookup in C++ requires looking into scopes
1497 // that aren't strictly lexical, and therefore we walk through the
1498 // context as well as walking through the scopes.
1499 for (; S; S = S->getParent()) {
1500 // Check whether the IdResolver has anything in this scope.
1501 bool Found = false;
1502 for (; I != IEnd && S->isDeclScope(D: *I); ++I) {
1503 if (NamedDecl *ND = R.getAcceptableDecl(D: *I)) {
1504 // We found something. Look for anything else in our scope
1505 // with this same name and in an acceptable identifier
1506 // namespace, so that we can construct an overload set if we
1507 // need to.
1508 Found = true;
1509 R.addDecl(D: ND);
1510 }
1511 }
1512
1513 if (Found && S->isTemplateParamScope()) {
1514 R.resolveKind();
1515 return true;
1516 }
1517
1518 DeclContext *Ctx = S->getLookupEntity();
1519 if (Ctx) {
1520 DeclContext *OuterCtx = findOuterContext(S);
1521 for (; Ctx && !Ctx->Equals(DC: OuterCtx); Ctx = Ctx->getLookupParent()) {
1522 // We do not directly look into transparent contexts, since
1523 // those entities will be found in the nearest enclosing
1524 // non-transparent context.
1525 if (Ctx->isTransparentContext())
1526 continue;
1527
1528 // If we have a context, and it's not a context stashed in the
1529 // template parameter scope for an out-of-line definition, also
1530 // look into that context.
1531 if (!(Found && S->isTemplateParamScope())) {
1532 assert(Ctx->isFileContext() &&
1533 "We should have been looking only at file context here already.");
1534
1535 // Look into context considering using-directives.
1536 if (CppNamespaceLookup(S&: *this, R, Context, NS: Ctx, UDirs))
1537 Found = true;
1538 }
1539
1540 if (Found) {
1541 R.resolveKind();
1542 return true;
1543 }
1544
1545 if (R.isForRedeclaration() && !Ctx->isTransparentContext())
1546 return false;
1547 }
1548 }
1549
1550 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
1551 return false;
1552 }
1553
1554 return !R.empty();
1555}
1556
1557void Sema::makeMergedDefinitionVisible(NamedDecl *ND) {
1558 if (auto *M = getCurrentModule())
1559 Context.mergeDefinitionIntoModule(ND, M);
1560 else
1561 // We're not building a module; just make the definition visible.
1562 ND->setVisibleDespiteOwningModule();
1563
1564 // If ND is a template declaration, make the template parameters
1565 // visible too. They're not (necessarily) within a mergeable DeclContext.
1566 if (auto *TD = dyn_cast<TemplateDecl>(Val: ND))
1567 for (auto *Param : *TD->getTemplateParameters())
1568 makeMergedDefinitionVisible(ND: Param);
1569
1570 // If we import a named module which contains a header, and then we include a
1571 // header which contains a definition of enums, we will skip parsing the enums
1572 // in the current TU. But we need to ensure the visibility of the enum
1573 // contants, since they are able to be found with the parents of their
1574 // parents.
1575 if (auto *ED = dyn_cast<EnumDecl>(Val: ND);
1576 ED && ED->isFromGlobalModule() && !ED->isScoped()) {
1577 for (auto *ECD : ED->enumerators()) {
1578 ECD->setVisiblePromoted();
1579 DeclContext *RedeclCtx = ED->getDeclContext()->getRedeclContext();
1580 if (RedeclCtx->lookup(Name: ECD->getDeclName()).empty())
1581 RedeclCtx->makeDeclVisibleInContext(D: ECD);
1582 }
1583 }
1584}
1585
1586/// Find the module in which the given declaration was defined.
1587static Module *getDefiningModule(Sema &S, Decl *Entity) {
1588 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: Entity)) {
1589 // If this function was instantiated from a template, the defining module is
1590 // the module containing the pattern.
1591 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1592 Entity = Pattern->getDefinition();
1593 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Val: Entity)) {
1594 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1595 Entity = Pattern->getDefinition();
1596 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Val: Entity)) {
1597 if (auto *Pattern = ED->getTemplateInstantiationPattern())
1598 Entity = Pattern->getDefinition();
1599 } else if (VarDecl *VD = dyn_cast<VarDecl>(Val: Entity)) {
1600 if (VarDecl *Pattern = VD->getTemplateInstantiationPattern())
1601 Entity = Pattern->getDefinition();
1602 }
1603 if (!Entity)
1604 return nullptr;
1605
1606 // Walk up to the containing context. That might also have been instantiated
1607 // from a template.
1608 DeclContext *Context = Entity->getLexicalDeclContext();
1609 if (Context->isFileContext())
1610 return S.getOwningModule(Entity);
1611 return getDefiningModule(S, Entity: cast<Decl>(Val: Context));
1612}
1613
1614llvm::DenseSet<Module*> &Sema::getLookupModules() {
1615 unsigned N = CodeSynthesisContexts.size();
1616 for (unsigned I = CodeSynthesisContextLookupModules.size();
1617 I != N; ++I) {
1618 Module *M = CodeSynthesisContexts[I].Entity ?
1619 getDefiningModule(S&: *this, Entity: CodeSynthesisContexts[I].Entity) :
1620 nullptr;
1621 if (M && !LookupModulesCache.insert(V: M).second)
1622 M = nullptr;
1623 CodeSynthesisContextLookupModules.push_back(Elt: M);
1624 }
1625 return LookupModulesCache;
1626}
1627
1628bool Sema::isUsableModule(const Module *M) {
1629 assert(M && "We shouldn't check nullness for module here");
1630 // Return quickly if we cached the result.
1631 if (UsableModuleUnitsCache.count(V: M))
1632 return true;
1633
1634 // If M is the global module fragment of the current translation unit. So it
1635 // should be usable.
1636 // [module.global.frag]p1:
1637 // The global module fragment can be used to provide declarations that are
1638 // attached to the global module and usable within the module unit.
1639 if (M == TheGlobalModuleFragment || M == TheImplicitGlobalModuleFragment) {
1640 UsableModuleUnitsCache.insert(V: M);
1641 return true;
1642 }
1643
1644 // Otherwise, the global module fragment from other translation unit is not
1645 // directly usable.
1646 if (M->isExplicitGlobalModule())
1647 return false;
1648
1649 Module *Current = getCurrentModule();
1650
1651 // If we're not parsing a module, we can't use all the declarations from
1652 // another module easily.
1653 if (!Current)
1654 return false;
1655
1656 // For implicit global module, the decls in the same modules with the parent
1657 // module should be visible to the decls in the implicit global module.
1658 if (Current->isImplicitGlobalModule())
1659 Current = Current->getTopLevelModule();
1660 if (M->isImplicitGlobalModule())
1661 M = M->getTopLevelModule();
1662
1663 // If M is the module we're parsing or M and the current module unit lives in
1664 // the same module, M should be usable.
1665 //
1666 // Note: It should be fine to search the vector `ModuleScopes` linearly since
1667 // it should be generally small enough. There should be rare module fragments
1668 // in a named module unit.
1669 if (llvm::count_if(Range&: ModuleScopes,
1670 P: [&M](const ModuleScope &MS) { return MS.Module == M; }) ||
1671 getASTContext().isInSameModule(M1: M, M2: Current)) {
1672 UsableModuleUnitsCache.insert(V: M);
1673 return true;
1674 }
1675
1676 return false;
1677}
1678
1679bool Sema::hasVisibleMergedDefinition(const NamedDecl *Def) {
1680 for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1681 if (isModuleVisible(M: Merged))
1682 return true;
1683 return false;
1684}
1685
1686bool Sema::hasMergedDefinitionInCurrentModule(const NamedDecl *Def) {
1687 for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1688 if (isUsableModule(M: Merged))
1689 return true;
1690 return false;
1691}
1692
1693template <typename ParmDecl>
1694static bool
1695hasAcceptableDefaultArgument(Sema &S, const ParmDecl *D,
1696 llvm::SmallVectorImpl<Module *> *Modules,
1697 Sema::AcceptableKind Kind) {
1698 if (!D->hasDefaultArgument())
1699 return false;
1700
1701 llvm::SmallPtrSet<const ParmDecl *, 4> Visited;
1702 while (D && Visited.insert(D).second) {
1703 auto &DefaultArg = D->getDefaultArgStorage();
1704 if (!DefaultArg.isInherited() && S.isAcceptable(D, Kind))
1705 return true;
1706
1707 if (!DefaultArg.isInherited() && Modules) {
1708 auto *NonConstD = const_cast<ParmDecl*>(D);
1709 Modules->push_back(Elt: S.getOwningModule(Entity: NonConstD));
1710 }
1711
1712 // If there was a previous default argument, maybe its parameter is
1713 // acceptable.
1714 D = DefaultArg.getInheritedFrom();
1715 }
1716 return false;
1717}
1718
1719bool Sema::hasAcceptableDefaultArgument(
1720 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules,
1721 Sema::AcceptableKind Kind) {
1722 if (auto *P = dyn_cast<TemplateTypeParmDecl>(Val: D))
1723 return ::hasAcceptableDefaultArgument(S&: *this, D: P, Modules, Kind);
1724
1725 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(Val: D))
1726 return ::hasAcceptableDefaultArgument(S&: *this, D: P, Modules, Kind);
1727
1728 return ::hasAcceptableDefaultArgument(
1729 S&: *this, D: cast<TemplateTemplateParmDecl>(Val: D), Modules, Kind);
1730}
1731
1732bool Sema::hasVisibleDefaultArgument(const NamedDecl *D,
1733 llvm::SmallVectorImpl<Module *> *Modules) {
1734 return hasAcceptableDefaultArgument(D, Modules,
1735 Kind: Sema::AcceptableKind::Visible);
1736}
1737
1738bool Sema::hasReachableDefaultArgument(
1739 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1740 return hasAcceptableDefaultArgument(D, Modules,
1741 Kind: Sema::AcceptableKind::Reachable);
1742}
1743
1744template <typename Filter>
1745static bool
1746hasAcceptableDeclarationImpl(Sema &S, const NamedDecl *D,
1747 llvm::SmallVectorImpl<Module *> *Modules, Filter F,
1748 Sema::AcceptableKind Kind) {
1749 bool HasFilteredRedecls = false;
1750
1751 for (auto *Redecl : D->redecls()) {
1752 auto *R = cast<NamedDecl>(Val: Redecl);
1753 if (!F(R))
1754 continue;
1755
1756 if (S.isAcceptable(D: R, Kind))
1757 return true;
1758
1759 HasFilteredRedecls = true;
1760
1761 if (Modules)
1762 Modules->push_back(Elt: R->getOwningModule());
1763 }
1764
1765 // Only return false if there is at least one redecl that is not filtered out.
1766 if (HasFilteredRedecls)
1767 return false;
1768
1769 return true;
1770}
1771
1772static bool
1773hasAcceptableExplicitSpecialization(Sema &S, const NamedDecl *D,
1774 llvm::SmallVectorImpl<Module *> *Modules,
1775 Sema::AcceptableKind Kind) {
1776 return hasAcceptableDeclarationImpl(
1777 S, D, Modules,
1778 F: [](const NamedDecl *D) {
1779 if (auto *RD = dyn_cast<CXXRecordDecl>(Val: D))
1780 return RD->getTemplateSpecializationKind() ==
1781 TSK_ExplicitSpecialization;
1782 if (auto *FD = dyn_cast<FunctionDecl>(Val: D))
1783 return FD->getTemplateSpecializationKind() ==
1784 TSK_ExplicitSpecialization;
1785 if (auto *VD = dyn_cast<VarDecl>(Val: D))
1786 return VD->getTemplateSpecializationKind() ==
1787 TSK_ExplicitSpecialization;
1788 llvm_unreachable("unknown explicit specialization kind");
1789 },
1790 Kind);
1791}
1792
1793bool Sema::hasVisibleExplicitSpecialization(
1794 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1795 return ::hasAcceptableExplicitSpecialization(S&: *this, D, Modules,
1796 Kind: Sema::AcceptableKind::Visible);
1797}
1798
1799bool Sema::hasReachableExplicitSpecialization(
1800 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1801 return ::hasAcceptableExplicitSpecialization(S&: *this, D, Modules,
1802 Kind: Sema::AcceptableKind::Reachable);
1803}
1804
1805static bool
1806hasAcceptableMemberSpecialization(Sema &S, const NamedDecl *D,
1807 llvm::SmallVectorImpl<Module *> *Modules,
1808 Sema::AcceptableKind Kind) {
1809 assert(isa<CXXRecordDecl>(D->getDeclContext()) &&
1810 "not a member specialization");
1811 return hasAcceptableDeclarationImpl(
1812 S, D, Modules,
1813 F: [](const NamedDecl *D) {
1814 // If the specialization is declared at namespace scope, then it's a
1815 // member specialization declaration. If it's lexically inside the class
1816 // definition then it was instantiated.
1817 //
1818 // FIXME: This is a hack. There should be a better way to determine
1819 // this.
1820 // FIXME: What about MS-style explicit specializations declared within a
1821 // class definition?
1822 return D->getLexicalDeclContext()->isFileContext();
1823 },
1824 Kind);
1825}
1826
1827bool Sema::hasVisibleMemberSpecialization(
1828 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1829 return hasAcceptableMemberSpecialization(S&: *this, D, Modules,
1830 Kind: Sema::AcceptableKind::Visible);
1831}
1832
1833bool Sema::hasReachableMemberSpecialization(
1834 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1835 return hasAcceptableMemberSpecialization(S&: *this, D, Modules,
1836 Kind: Sema::AcceptableKind::Reachable);
1837}
1838
1839/// Determine whether a declaration is acceptable to name lookup.
1840///
1841/// This routine determines whether the declaration D is acceptable in the
1842/// current lookup context, taking into account the current template
1843/// instantiation stack. During template instantiation, a declaration is
1844/// acceptable if it is acceptable from a module containing any entity on the
1845/// template instantiation path (by instantiating a template, you allow it to
1846/// see the declarations that your module can see, including those later on in
1847/// your module).
1848bool LookupResult::isAcceptableSlow(Sema &SemaRef, NamedDecl *D,
1849 Sema::AcceptableKind Kind) {
1850 assert(!D->isUnconditionallyVisible() &&
1851 "should not call this: not in slow case");
1852
1853 Module *DeclModule = SemaRef.getOwningModule(Entity: D);
1854 assert(DeclModule && "hidden decl has no owning module");
1855
1856 // If the owning module is visible, the decl is acceptable.
1857 if (SemaRef.isModuleVisible(M: DeclModule,
1858 ModulePrivate: D->isInvisibleOutsideTheOwningModule()))
1859 return true;
1860
1861 // Determine whether a decl context is a file context for the purpose of
1862 // visibility/reachability. This looks through some (export and linkage spec)
1863 // transparent contexts, but not others (enums).
1864 auto IsEffectivelyFileContext = [](const DeclContext *DC) {
1865 return DC->isFileContext() || isa<LinkageSpecDecl>(Val: DC) ||
1866 isa<ExportDecl>(Val: DC);
1867 };
1868
1869 // If this declaration is not at namespace scope
1870 // then it is acceptable if its lexical parent has a acceptable definition.
1871 DeclContext *DC = D->getLexicalDeclContext();
1872 if (DC && !IsEffectivelyFileContext(DC)) {
1873 // For a parameter, check whether our current template declaration's
1874 // lexical context is acceptable, not whether there's some other acceptable
1875 // definition of it, because parameters aren't "within" the definition.
1876 //
1877 // In C++ we need to check for a acceptable definition due to ODR merging,
1878 // and in C we must not because each declaration of a function gets its own
1879 // set of declarations for tags in prototype scope.
1880 bool AcceptableWithinParent;
1881 if (D->isTemplateParameter()) {
1882 bool SearchDefinitions = true;
1883 if (const auto *DCD = dyn_cast<Decl>(Val: DC)) {
1884 if (const auto *TD = DCD->getDescribedTemplate()) {
1885 TemplateParameterList *TPL = TD->getTemplateParameters();
1886 auto Index = getDepthAndIndex(ND: D).second;
1887 SearchDefinitions = Index >= TPL->size() || TPL->getParam(Idx: Index) != D;
1888 }
1889 }
1890 if (SearchDefinitions)
1891 AcceptableWithinParent =
1892 SemaRef.hasAcceptableDefinition(D: cast<NamedDecl>(Val: DC), Kind);
1893 else
1894 AcceptableWithinParent =
1895 isAcceptable(SemaRef, D: cast<NamedDecl>(Val: DC), Kind);
1896 } else if (isa<ParmVarDecl>(Val: D) ||
1897 (isa<FunctionDecl>(Val: DC) && !SemaRef.getLangOpts().CPlusPlus))
1898 AcceptableWithinParent = isAcceptable(SemaRef, D: cast<NamedDecl>(Val: DC), Kind);
1899 else if (D->isModulePrivate()) {
1900 // A module-private declaration is only acceptable if an enclosing lexical
1901 // parent was merged with another definition in the current module.
1902 AcceptableWithinParent = false;
1903 do {
1904 if (SemaRef.hasMergedDefinitionInCurrentModule(Def: cast<NamedDecl>(Val: DC))) {
1905 AcceptableWithinParent = true;
1906 break;
1907 }
1908 DC = DC->getLexicalParent();
1909 } while (!IsEffectivelyFileContext(DC));
1910 } else {
1911 AcceptableWithinParent =
1912 SemaRef.hasAcceptableDefinition(D: cast<NamedDecl>(Val: DC), Kind);
1913 }
1914
1915 if (AcceptableWithinParent && SemaRef.CodeSynthesisContexts.empty() &&
1916 Kind == Sema::AcceptableKind::Visible &&
1917 // FIXME: Do something better in this case.
1918 !SemaRef.getLangOpts().ModulesLocalVisibility) {
1919 // Cache the fact that this declaration is implicitly visible because
1920 // its parent has a visible definition.
1921 D->setVisibleDespiteOwningModule();
1922 }
1923 return AcceptableWithinParent;
1924 }
1925
1926 if (Kind == Sema::AcceptableKind::Visible)
1927 return false;
1928
1929 assert(Kind == Sema::AcceptableKind::Reachable &&
1930 "Additional Sema::AcceptableKind?");
1931 return isReachableSlow(SemaRef, D);
1932}
1933
1934bool Sema::isModuleVisible(const Module *M, bool ModulePrivate) {
1935 // The module might be ordinarily visible. For a module-private query, that
1936 // means it is part of the current module.
1937 if (ModulePrivate && isUsableModule(M))
1938 return true;
1939
1940 // For a query which is not module-private, that means it is in our visible
1941 // module set.
1942 if (!ModulePrivate && VisibleModules.isVisible(M))
1943 return true;
1944
1945 // Otherwise, it might be visible by virtue of the query being within a
1946 // template instantiation or similar that is permitted to look inside M.
1947
1948 // Find the extra places where we need to look.
1949 const auto &LookupModules = getLookupModules();
1950 if (LookupModules.empty())
1951 return false;
1952
1953 // If our lookup set contains the module, it's visible.
1954 if (LookupModules.count(V: M))
1955 return true;
1956
1957 // The global module fragments are visible to its corresponding module unit.
1958 // So the global module fragment should be visible if the its corresponding
1959 // module unit is visible.
1960 if (M->isGlobalModule() && LookupModules.count(V: M->getTopLevelModule()))
1961 return true;
1962
1963 // For a module-private query, that's everywhere we get to look.
1964 if (ModulePrivate)
1965 return false;
1966
1967 // Check whether M is transitively exported to an import of the lookup set.
1968 return llvm::any_of(Range: LookupModules, P: [&](const Module *LookupM) {
1969 return LookupM->isModuleVisible(M);
1970 });
1971}
1972
1973// FIXME: Return false directly if we don't have an interface dependency on the
1974// translation unit containing D.
1975bool LookupResult::isReachableSlow(Sema &SemaRef, NamedDecl *D) {
1976 assert(!isVisible(SemaRef, D) && "Shouldn't call the slow case.\n");
1977
1978 Module *DeclModule = SemaRef.getOwningModule(Entity: D);
1979 assert(DeclModule && "hidden decl has no owning module");
1980
1981 // Entities in header like modules are reachable only if they're visible.
1982 if (DeclModule->isHeaderLikeModule())
1983 return false;
1984
1985 if (!D->isInAnotherModuleUnit())
1986 return true;
1987
1988 // [module.reach]/p3:
1989 // A declaration D is reachable from a point P if:
1990 // ...
1991 // - D is not discarded ([module.global.frag]), appears in a translation unit
1992 // that is reachable from P, and does not appear within a private module
1993 // fragment.
1994 //
1995 // A declaration that's discarded in the GMF should be module-private.
1996 if (D->isModulePrivate())
1997 return false;
1998
1999 Module *DeclTopModule = DeclModule->getTopLevelModule();
2000
2001 // [module.reach]/p1
2002 // A translation unit U is necessarily reachable from a point P if U is a
2003 // module interface unit on which the translation unit containing P has an
2004 // interface dependency, or the translation unit containing P imports U, in
2005 // either case prior to P ([module.import]).
2006 //
2007 // [module.import]/p10
2008 // A translation unit has an interface dependency on a translation unit U if
2009 // it contains a declaration (possibly a module-declaration) that imports U
2010 // or if it has an interface dependency on a translation unit that has an
2011 // interface dependency on U.
2012 //
2013 // So we could conclude the module unit U is necessarily reachable if:
2014 // (1) The module unit U is module interface unit.
2015 // (2) The current unit has an interface dependency on the module unit U.
2016 //
2017 // Here we only check for the first condition. Since we couldn't see
2018 // DeclModule if it isn't (transitively) imported.
2019 if (DeclTopModule->isModuleInterfaceUnit())
2020 return true;
2021
2022 // [module.reach]/p1,2
2023 // A translation unit U is necessarily reachable from a point P if U is a
2024 // module interface unit on which the translation unit containing P has an
2025 // interface dependency, or the translation unit containing P imports U, in
2026 // either case prior to P
2027 //
2028 // Additional translation units on
2029 // which the point within the program has an interface dependency may be
2030 // considered reachable, but it is unspecified which are and under what
2031 // circumstances.
2032 Module *CurrentM = SemaRef.getCurrentModule();
2033
2034 // Directly imported module are necessarily reachable.
2035 // Since we can't export import a module implementation partition unit, we
2036 // don't need to count for Exports here.
2037 if (CurrentM &&
2038 llvm::is_contained(Range&: CurrentM->getTopLevelModule()->Imports, Element: DeclTopModule))
2039 return true;
2040
2041 // Then we treat all module implementation partition unit as unreachable.
2042 return false;
2043}
2044
2045bool Sema::isAcceptableSlow(const NamedDecl *D, Sema::AcceptableKind Kind) {
2046 return LookupResult::isAcceptable(SemaRef&: *this, D: const_cast<NamedDecl *>(D), Kind);
2047}
2048
2049bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
2050 // FIXME: If there are both visible and hidden declarations, we need to take
2051 // into account whether redeclaration is possible. Example:
2052 //
2053 // Non-imported module:
2054 // int f(T); // #1
2055 // Some TU:
2056 // static int f(U); // #2, not a redeclaration of #1
2057 // int f(T); // #3, finds both, should link with #1 if T != U, but
2058 // // with #2 if T == U; neither should be ambiguous.
2059 for (auto *D : R) {
2060 if (isVisible(D))
2061 return true;
2062 assert(D->isExternallyDeclarable() &&
2063 "should not have hidden, non-externally-declarable result here");
2064 }
2065
2066 // This function is called once "New" is essentially complete, but before a
2067 // previous declaration is attached. We can't query the linkage of "New" in
2068 // general, because attaching the previous declaration can change the
2069 // linkage of New to match the previous declaration.
2070 //
2071 // However, because we've just determined that there is no *visible* prior
2072 // declaration, we can compute the linkage here. There are two possibilities:
2073 //
2074 // * This is not a redeclaration; it's safe to compute the linkage now.
2075 //
2076 // * This is a redeclaration of a prior declaration that is externally
2077 // redeclarable. In that case, the linkage of the declaration is not
2078 // changed by attaching the prior declaration, because both are externally
2079 // declarable (and thus ExternalLinkage or VisibleNoLinkage).
2080 //
2081 // FIXME: This is subtle and fragile.
2082 return New->isExternallyDeclarable();
2083}
2084
2085/// Retrieve the visible declaration corresponding to D, if any.
2086///
2087/// This routine determines whether the declaration D is visible in the current
2088/// module, with the current imports. If not, it checks whether any
2089/// redeclaration of D is visible, and if so, returns that declaration.
2090///
2091/// \returns D, or a visible previous declaration of D, whichever is more recent
2092/// and visible. If no declaration of D is visible, returns null.
2093static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D,
2094 unsigned IDNS) {
2095 assert(!LookupResult::isAvailableForLookup(SemaRef, D) && "not in slow case");
2096
2097 for (auto *RD : D->redecls()) {
2098 // Don't bother with extra checks if we already know this one isn't visible.
2099 if (RD == D)
2100 continue;
2101
2102 auto ND = cast<NamedDecl>(Val: RD);
2103 // FIXME: This is wrong in the case where the previous declaration is not
2104 // visible in the same scope as D. This needs to be done much more
2105 // carefully.
2106 if (ND->isInIdentifierNamespace(NS: IDNS) &&
2107 LookupResult::isAvailableForLookup(SemaRef, ND))
2108 return ND;
2109 }
2110
2111 return nullptr;
2112}
2113
2114bool Sema::hasVisibleDeclarationSlow(const NamedDecl *D,
2115 llvm::SmallVectorImpl<Module *> *Modules) {
2116 assert(!isVisible(D) && "not in slow case");
2117 return hasAcceptableDeclarationImpl(
2118 S&: *this, D, Modules, F: [](const NamedDecl *) { return true; },
2119 Kind: Sema::AcceptableKind::Visible);
2120}
2121
2122bool Sema::hasReachableDeclarationSlow(
2123 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
2124 assert(!isReachable(D) && "not in slow case");
2125 return hasAcceptableDeclarationImpl(
2126 S&: *this, D, Modules, F: [](const NamedDecl *) { return true; },
2127 Kind: Sema::AcceptableKind::Reachable);
2128}
2129
2130NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
2131 if (auto *ND = dyn_cast<NamespaceDecl>(Val: D)) {
2132 // Namespaces are a bit of a special case: we expect there to be a lot of
2133 // redeclarations of some namespaces, all declarations of a namespace are
2134 // essentially interchangeable, all declarations are found by name lookup
2135 // if any is, and namespaces are never looked up during template
2136 // instantiation. So we benefit from caching the check in this case, and
2137 // it is correct to do so.
2138 auto *Key = ND->getCanonicalDecl();
2139 if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Val: Key))
2140 return Acceptable;
2141 auto *Acceptable = isVisible(SemaRef&: getSema(), D: Key)
2142 ? Key
2143 : findAcceptableDecl(SemaRef&: getSema(), D: Key, IDNS);
2144 if (Acceptable)
2145 getSema().VisibleNamespaceCache.insert(KV: std::make_pair(x&: Key, y&: Acceptable));
2146 return Acceptable;
2147 }
2148
2149 return findAcceptableDecl(SemaRef&: getSema(), D, IDNS);
2150}
2151
2152bool LookupResult::isVisible(Sema &SemaRef, NamedDecl *D) {
2153 // If this declaration is already visible, return it directly.
2154 if (D->isUnconditionallyVisible())
2155 return true;
2156
2157 // During template instantiation, we can refer to hidden declarations, if
2158 // they were visible in any module along the path of instantiation.
2159 return isAcceptableSlow(SemaRef, D, Kind: Sema::AcceptableKind::Visible);
2160}
2161
2162bool LookupResult::isReachable(Sema &SemaRef, NamedDecl *D) {
2163 if (D->isUnconditionallyVisible())
2164 return true;
2165
2166 return isAcceptableSlow(SemaRef, D, Kind: Sema::AcceptableKind::Reachable);
2167}
2168
2169bool LookupResult::isAvailableForLookup(Sema &SemaRef, NamedDecl *ND) {
2170 // We should check the visibility at the callsite already.
2171 if (isVisible(SemaRef, D: ND))
2172 return true;
2173
2174 // Deduction guide lives in namespace scope generally, but it is just a
2175 // hint to the compilers. What we actually lookup for is the generated member
2176 // of the corresponding template. So it is sufficient to check the
2177 // reachability of the template decl.
2178 if (auto *DeductionGuide = ND->getDeclName().getCXXDeductionGuideTemplate())
2179 return SemaRef.hasReachableDefinition(D: DeductionGuide);
2180
2181 // FIXME: The lookup for allocation function is a standalone process.
2182 // (We can find the logics in Sema::FindAllocationFunctions)
2183 //
2184 // Such structure makes it a problem when we instantiate a template
2185 // declaration using placement allocation function if the placement
2186 // allocation function is invisible.
2187 // (See https://github.com/llvm/llvm-project/issues/59601)
2188 //
2189 // Here we workaround it by making the placement allocation functions
2190 // always acceptable. The downside is that we can't diagnose the direct
2191 // use of the invisible placement allocation functions. (Although such uses
2192 // should be rare).
2193 if (auto *FD = dyn_cast<FunctionDecl>(Val: ND);
2194 FD && FD->isReservedGlobalPlacementOperator())
2195 return true;
2196
2197 auto *DC = ND->getDeclContext();
2198 // If ND is not visible and it is at namespace scope, it shouldn't be found
2199 // by name lookup.
2200 if (DC->isFileContext())
2201 return false;
2202
2203 // [module.interface]p7
2204 // Class and enumeration member names can be found by name lookup in any
2205 // context in which a definition of the type is reachable.
2206 //
2207 // NOTE: The above wording may be problematic. See
2208 // https://github.com/llvm/llvm-project/issues/131058 But it is much complext
2209 // to adjust it in Sema's lookup process. Now we hacked it in ASTWriter. See
2210 // the comments in ASTDeclContextNameLookupTrait::getLookupVisibility.
2211 if (auto *TD = dyn_cast<TagDecl>(Val: DC))
2212 return SemaRef.hasReachableDefinition(D: TD);
2213
2214 return false;
2215}
2216
2217bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation,
2218 bool ForceNoCPlusPlus) {
2219 DeclarationName Name = R.getLookupName();
2220 if (!Name) return false;
2221
2222 LookupNameKind NameKind = R.getLookupKind();
2223
2224 if (!getLangOpts().CPlusPlus || ForceNoCPlusPlus) {
2225 // Unqualified name lookup in C/Objective-C is purely lexical, so
2226 // search in the declarations attached to the name.
2227 if (NameKind == Sema::LookupRedeclarationWithLinkage) {
2228 // Find the nearest non-transparent declaration scope.
2229 while (!(S->getFlags() & Scope::DeclScope) ||
2230 (S->getEntity() && S->getEntity()->isTransparentContext()))
2231 S = S->getParent();
2232 }
2233
2234 // When performing a scope lookup, we want to find local extern decls.
2235 FindLocalExternScope FindLocals(R);
2236
2237 // Scan up the scope chain looking for a decl that matches this
2238 // identifier that is in the appropriate namespace. This search
2239 // should not take long, as shadowing of names is uncommon, and
2240 // deep shadowing is extremely uncommon.
2241 bool LeftStartingScope = false;
2242
2243 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
2244 IEnd = IdResolver.end();
2245 I != IEnd; ++I)
2246 if (NamedDecl *D = R.getAcceptableDecl(D: *I)) {
2247 if (NameKind == LookupRedeclarationWithLinkage) {
2248 // Determine whether this (or a previous) declaration is
2249 // out-of-scope.
2250 if (!LeftStartingScope && !S->isDeclScope(D: *I))
2251 LeftStartingScope = true;
2252
2253 // If we found something outside of our starting scope that
2254 // does not have linkage, skip it.
2255 if (LeftStartingScope && !((*I)->hasLinkage())) {
2256 R.setShadowed();
2257 continue;
2258 }
2259 }
2260 else if (NameKind == LookupObjCImplicitSelfParam &&
2261 !isa<ImplicitParamDecl>(Val: *I))
2262 continue;
2263
2264 R.addDecl(D);
2265
2266 // Check whether there are any other declarations with the same name
2267 // and in the same scope.
2268 if (I != IEnd) {
2269 // Find the scope in which this declaration was declared (if it
2270 // actually exists in a Scope).
2271 while (S && !S->isDeclScope(D))
2272 S = S->getParent();
2273
2274 // If the scope containing the declaration is the translation unit,
2275 // then we'll need to perform our checks based on the matching
2276 // DeclContexts rather than matching scopes.
2277 if (S && isNamespaceOrTranslationUnitScope(S))
2278 S = nullptr;
2279
2280 // Compute the DeclContext, if we need it.
2281 DeclContext *DC = nullptr;
2282 if (!S)
2283 DC = (*I)->getDeclContext()->getRedeclContext();
2284
2285 IdentifierResolver::iterator LastI = I;
2286 for (++LastI; LastI != IEnd; ++LastI) {
2287 if (S) {
2288 // Match based on scope.
2289 if (!S->isDeclScope(D: *LastI))
2290 break;
2291 } else {
2292 // Match based on DeclContext.
2293 DeclContext *LastDC
2294 = (*LastI)->getDeclContext()->getRedeclContext();
2295 if (!LastDC->Equals(DC))
2296 break;
2297 }
2298
2299 // If the declaration is in the right namespace and visible, add it.
2300 if (NamedDecl *LastD = R.getAcceptableDecl(D: *LastI))
2301 R.addDecl(D: LastD);
2302 }
2303
2304 R.resolveKind();
2305 }
2306
2307 return true;
2308 }
2309 } else {
2310 // Perform C++ unqualified name lookup.
2311 if (CppLookupName(R, S))
2312 return true;
2313 }
2314
2315 // If we didn't find a use of this identifier, and if the identifier
2316 // corresponds to a compiler builtin, create the decl object for the builtin
2317 // now, injecting it into translation unit scope, and return it.
2318 if (AllowBuiltinCreation && LookupBuiltin(R))
2319 return true;
2320
2321 // If we didn't find a use of this identifier, the ExternalSource
2322 // may be able to handle the situation.
2323 // Note: some lookup failures are expected!
2324 // See e.g. R.isForRedeclaration().
2325 return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
2326}
2327
2328/// Perform qualified name lookup in the namespaces nominated by
2329/// using directives by the given context.
2330///
2331/// C++98 [namespace.qual]p2:
2332/// Given X::m (where X is a user-declared namespace), or given \::m
2333/// (where X is the global namespace), let S be the set of all
2334/// declarations of m in X and in the transitive closure of all
2335/// namespaces nominated by using-directives in X and its used
2336/// namespaces, except that using-directives are ignored in any
2337/// namespace, including X, directly containing one or more
2338/// declarations of m. No namespace is searched more than once in
2339/// the lookup of a name. If S is the empty set, the program is
2340/// ill-formed. Otherwise, if S has exactly one member, or if the
2341/// context of the reference is a using-declaration
2342/// (namespace.udecl), S is the required set of declarations of
2343/// m. Otherwise if the use of m is not one that allows a unique
2344/// declaration to be chosen from S, the program is ill-formed.
2345///
2346/// C++98 [namespace.qual]p5:
2347/// During the lookup of a qualified namespace member name, if the
2348/// lookup finds more than one declaration of the member, and if one
2349/// declaration introduces a class name or enumeration name and the
2350/// other declarations either introduce the same object, the same
2351/// enumerator or a set of functions, the non-type name hides the
2352/// class or enumeration name if and only if the declarations are
2353/// from the same namespace; otherwise (the declarations are from
2354/// different namespaces), the program is ill-formed.
2355static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
2356 DeclContext *StartDC) {
2357 assert(StartDC->isFileContext() && "start context is not a file context");
2358
2359 // We have not yet looked into these namespaces, much less added
2360 // their "using-children" to the queue.
2361 SmallVector<NamespaceDecl*, 8> Queue;
2362
2363 // We have at least added all these contexts to the queue.
2364 llvm::SmallPtrSet<DeclContext*, 8> Visited;
2365 Visited.insert(Ptr: StartDC);
2366
2367 // We have already looked into the initial namespace; seed the queue
2368 // with its using-children.
2369 for (auto *I : StartDC->using_directives()) {
2370 NamespaceDecl *ND = I->getNominatedNamespace()->getFirstDecl();
2371 if (S.isVisible(D: I) && Visited.insert(Ptr: ND).second)
2372 Queue.push_back(Elt: ND);
2373 }
2374
2375 // The easiest way to implement the restriction in [namespace.qual]p5
2376 // is to check whether any of the individual results found a tag
2377 // and, if so, to declare an ambiguity if the final result is not
2378 // a tag.
2379 bool FoundTag = false;
2380 bool FoundNonTag = false;
2381
2382 LookupResult LocalR(LookupResult::Temporary, R);
2383
2384 bool Found = false;
2385 while (!Queue.empty()) {
2386 NamespaceDecl *ND = Queue.pop_back_val();
2387
2388 // We go through some convolutions here to avoid copying results
2389 // between LookupResults.
2390 bool UseLocal = !R.empty();
2391 LookupResult &DirectR = UseLocal ? LocalR : R;
2392 bool FoundDirect = LookupDirect(S, R&: DirectR, DC: ND);
2393
2394 if (FoundDirect) {
2395 // First do any local hiding.
2396 DirectR.resolveKind();
2397
2398 // If the local result is a tag, remember that.
2399 if (DirectR.isSingleTagDecl())
2400 FoundTag = true;
2401 else
2402 FoundNonTag = true;
2403
2404 // Append the local results to the total results if necessary.
2405 if (UseLocal) {
2406 R.addAllDecls(Other: LocalR);
2407 LocalR.clear();
2408 }
2409 }
2410
2411 // If we find names in this namespace, ignore its using directives.
2412 if (FoundDirect) {
2413 Found = true;
2414 continue;
2415 }
2416
2417 for (auto *I : ND->using_directives()) {
2418 NamespaceDecl *Nom = I->getNominatedNamespace();
2419 if (S.isVisible(D: I) && Visited.insert(Ptr: Nom).second)
2420 Queue.push_back(Elt: Nom);
2421 }
2422 }
2423
2424 if (Found) {
2425 if (FoundTag && FoundNonTag)
2426 R.setAmbiguousQualifiedTagHiding();
2427 else
2428 R.resolveKind();
2429 }
2430
2431 return Found;
2432}
2433
2434bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2435 bool InUnqualifiedLookup) {
2436 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
2437
2438 if (!R.getLookupName())
2439 return false;
2440
2441#ifndef NDEBUG
2442 // Make sure that the declaration context is complete.
2443 if (const auto *TD = dyn_cast<TagDecl>(LookupCtx);
2444 TD && !TD->isDependentType() && TD->getDefinition() == nullptr)
2445 llvm_unreachable("Declaration context must already be complete!");
2446#endif
2447
2448 struct QualifiedLookupInScope {
2449 bool oldVal;
2450 DeclContext *Context;
2451 // Set flag in DeclContext informing debugger that we're looking for qualified name
2452 QualifiedLookupInScope(DeclContext *ctx)
2453 : oldVal(ctx->shouldUseQualifiedLookup()), Context(ctx) {
2454 ctx->setUseQualifiedLookup();
2455 }
2456 ~QualifiedLookupInScope() {
2457 Context->setUseQualifiedLookup(oldVal);
2458 }
2459 } QL(LookupCtx);
2460
2461 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(Val: LookupCtx);
2462 // FIXME: Per [temp.dep.general]p2, an unqualified name is also dependent
2463 // if it's a dependent conversion-function-id or operator= where the current
2464 // class is a templated entity. This should be handled in LookupName.
2465 if (!InUnqualifiedLookup && !R.isForRedeclaration()) {
2466 // C++23 [temp.dep.type]p5:
2467 // A qualified name is dependent if
2468 // - it is a conversion-function-id whose conversion-type-id
2469 // is dependent, or
2470 // - [...]
2471 // - its lookup context is the current instantiation and it
2472 // is operator=, or
2473 // - [...]
2474 if (DeclarationName Name = R.getLookupName();
2475 Name.getNameKind() == DeclarationName::CXXConversionFunctionName &&
2476 Name.getCXXNameType()->isDependentType()) {
2477 R.setNotFoundInCurrentInstantiation();
2478 return false;
2479 }
2480 }
2481
2482 if (LookupDirect(S&: *this, R, DC: LookupCtx)) {
2483 R.resolveKind();
2484 if (LookupRec)
2485 R.setNamingClass(LookupRec);
2486 return true;
2487 }
2488
2489 // Don't descend into implied contexts for redeclarations.
2490 // C++98 [namespace.qual]p6:
2491 // In a declaration for a namespace member in which the
2492 // declarator-id is a qualified-id, given that the qualified-id
2493 // for the namespace member has the form
2494 // nested-name-specifier unqualified-id
2495 // the unqualified-id shall name a member of the namespace
2496 // designated by the nested-name-specifier.
2497 // See also [class.mfct]p5 and [class.static.data]p2.
2498 if (R.isForRedeclaration())
2499 return false;
2500
2501 // If this is a namespace, look it up in the implied namespaces.
2502 if (LookupCtx->isFileContext())
2503 return LookupQualifiedNameInUsingDirectives(S&: *this, R, StartDC: LookupCtx);
2504
2505 // If this isn't a C++ class, we aren't allowed to look into base
2506 // classes, we're done.
2507 if (!LookupRec || !LookupRec->getDefinition())
2508 return false;
2509
2510 // We're done for lookups that can never succeed for C++ classes.
2511 if (R.getLookupKind() == LookupOperatorName ||
2512 R.getLookupKind() == LookupNamespaceName ||
2513 R.getLookupKind() == LookupObjCProtocolName ||
2514 R.getLookupKind() == LookupLabel)
2515 return false;
2516
2517 // If we're performing qualified name lookup into a dependent class,
2518 // then we are actually looking into a current instantiation. If we have any
2519 // dependent base classes, then we either have to delay lookup until
2520 // template instantiation time (at which point all bases will be available)
2521 // or we have to fail.
2522 if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
2523 LookupRec->hasAnyDependentBases()) {
2524 R.setNotFoundInCurrentInstantiation();
2525 return false;
2526 }
2527
2528 // Perform lookup into our base classes.
2529
2530 DeclarationName Name = R.getLookupName();
2531 unsigned IDNS = R.getIdentifierNamespace();
2532
2533 // Look for this member in our base classes.
2534 auto BaseCallback = [Name, IDNS](const CXXBaseSpecifier *Specifier,
2535 CXXBasePath &Path) -> bool {
2536 CXXRecordDecl *BaseRecord = Specifier->getType()->getAsCXXRecordDecl();
2537 // Drop leading non-matching lookup results from the declaration list so
2538 // we don't need to consider them again below.
2539 for (Path.Decls = BaseRecord->lookup(Name).begin();
2540 Path.Decls != Path.Decls.end(); ++Path.Decls) {
2541 if ((*Path.Decls)->isInIdentifierNamespace(NS: IDNS))
2542 return true;
2543 }
2544 return false;
2545 };
2546
2547 CXXBasePaths Paths;
2548 Paths.setOrigin(LookupRec);
2549 if (!LookupRec->lookupInBases(BaseMatches: BaseCallback, Paths))
2550 return false;
2551
2552 R.setNamingClass(LookupRec);
2553
2554 // C++ [class.member.lookup]p2:
2555 // [...] If the resulting set of declarations are not all from
2556 // sub-objects of the same type, or the set has a nonstatic member
2557 // and includes members from distinct sub-objects, there is an
2558 // ambiguity and the program is ill-formed. Otherwise that set is
2559 // the result of the lookup.
2560 QualType SubobjectType;
2561 int SubobjectNumber = 0;
2562 AccessSpecifier SubobjectAccess = AS_none;
2563
2564 // Check whether the given lookup result contains only static members.
2565 auto HasOnlyStaticMembers = [&](DeclContext::lookup_iterator Result) {
2566 for (DeclContext::lookup_iterator I = Result, E = I.end(); I != E; ++I)
2567 if ((*I)->isInIdentifierNamespace(NS: IDNS) && (*I)->isCXXInstanceMember())
2568 return false;
2569 return true;
2570 };
2571
2572 bool TemplateNameLookup = R.isTemplateNameLookup();
2573
2574 // Determine whether two sets of members contain the same members, as
2575 // required by C++ [class.member.lookup]p6.
2576 auto HasSameDeclarations = [&](DeclContext::lookup_iterator A,
2577 DeclContext::lookup_iterator B) {
2578 using Iterator = DeclContextLookupResult::iterator;
2579 using Result = const void *;
2580
2581 auto Next = [&](Iterator &It, Iterator End) -> Result {
2582 while (It != End) {
2583 NamedDecl *ND = *It++;
2584 if (!ND->isInIdentifierNamespace(NS: IDNS))
2585 continue;
2586
2587 // C++ [temp.local]p3:
2588 // A lookup that finds an injected-class-name (10.2) can result in
2589 // an ambiguity in certain cases (for example, if it is found in
2590 // more than one base class). If all of the injected-class-names
2591 // that are found refer to specializations of the same class
2592 // template, and if the name is used as a template-name, the
2593 // reference refers to the class template itself and not a
2594 // specialization thereof, and is not ambiguous.
2595 if (TemplateNameLookup)
2596 if (auto *TD = getAsTemplateNameDecl(D: ND))
2597 ND = TD;
2598
2599 // C++ [class.member.lookup]p3:
2600 // type declarations (including injected-class-names) are replaced by
2601 // the types they designate
2602 if (const TypeDecl *TD = dyn_cast<TypeDecl>(Val: ND->getUnderlyingDecl()))
2603 return Context.getCanonicalTypeDeclType(TD).getAsOpaquePtr();
2604
2605 return ND->getUnderlyingDecl()->getCanonicalDecl();
2606 }
2607 return nullptr;
2608 };
2609
2610 // We'll often find the declarations are in the same order. Handle this
2611 // case (and the special case of only one declaration) efficiently.
2612 Iterator AIt = A, BIt = B, AEnd, BEnd;
2613 while (true) {
2614 Result AResult = Next(AIt, AEnd);
2615 Result BResult = Next(BIt, BEnd);
2616 if (!AResult && !BResult)
2617 return true;
2618 if (!AResult || !BResult)
2619 return false;
2620 if (AResult != BResult) {
2621 // Found a mismatch; carefully check both lists, accounting for the
2622 // possibility of declarations appearing more than once.
2623 llvm::SmallDenseMap<Result, bool, 32> AResults;
2624 for (; AResult; AResult = Next(AIt, AEnd))
2625 AResults.insert(KV: {AResult, /*FoundInB*/false});
2626 unsigned Found = 0;
2627 for (; BResult; BResult = Next(BIt, BEnd)) {
2628 auto It = AResults.find(Val: BResult);
2629 if (It == AResults.end())
2630 return false;
2631 if (!It->second) {
2632 It->second = true;
2633 ++Found;
2634 }
2635 }
2636 return AResults.size() == Found;
2637 }
2638 }
2639 };
2640
2641 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
2642 Path != PathEnd; ++Path) {
2643 const CXXBasePathElement &PathElement = Path->back();
2644
2645 // Pick the best (i.e. most permissive i.e. numerically lowest) access
2646 // across all paths.
2647 SubobjectAccess = std::min(a: SubobjectAccess, b: Path->Access);
2648
2649 // Determine whether we're looking at a distinct sub-object or not.
2650 if (SubobjectType.isNull()) {
2651 // This is the first subobject we've looked at. Record its type.
2652 SubobjectType = Context.getCanonicalType(T: PathElement.Base->getType());
2653 SubobjectNumber = PathElement.SubobjectNumber;
2654 continue;
2655 }
2656
2657 if (SubobjectType !=
2658 Context.getCanonicalType(T: PathElement.Base->getType())) {
2659 // We found members of the given name in two subobjects of
2660 // different types. If the declaration sets aren't the same, this
2661 // lookup is ambiguous.
2662 //
2663 // FIXME: The language rule says that this applies irrespective of
2664 // whether the sets contain only static members.
2665 if (HasOnlyStaticMembers(Path->Decls) &&
2666 HasSameDeclarations(Paths.begin()->Decls, Path->Decls))
2667 continue;
2668
2669 R.setAmbiguousBaseSubobjectTypes(Paths);
2670 return true;
2671 }
2672
2673 // FIXME: This language rule no longer exists. Checking for ambiguous base
2674 // subobjects should be done as part of formation of a class member access
2675 // expression (when converting the object parameter to the member's type).
2676 if (SubobjectNumber != PathElement.SubobjectNumber) {
2677 // We have a different subobject of the same type.
2678
2679 // C++ [class.member.lookup]p5:
2680 // A static member, a nested type or an enumerator defined in
2681 // a base class T can unambiguously be found even if an object
2682 // has more than one base class subobject of type T.
2683 if (HasOnlyStaticMembers(Path->Decls))
2684 continue;
2685
2686 // We have found a nonstatic member name in multiple, distinct
2687 // subobjects. Name lookup is ambiguous.
2688 R.setAmbiguousBaseSubobjects(Paths);
2689 return true;
2690 }
2691 }
2692
2693 // Lookup in a base class succeeded; return these results.
2694
2695 for (DeclContext::lookup_iterator I = Paths.front().Decls, E = I.end();
2696 I != E; ++I) {
2697 AccessSpecifier AS = CXXRecordDecl::MergeAccess(PathAccess: SubobjectAccess,
2698 DeclAccess: (*I)->getAccess());
2699 if (NamedDecl *ND = R.getAcceptableDecl(D: *I))
2700 R.addDecl(D: ND, AS);
2701 }
2702 R.resolveKind();
2703 return true;
2704}
2705
2706bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2707 CXXScopeSpec &SS) {
2708 NestedNameSpecifier Qualifier = SS.getScopeRep();
2709 if (Qualifier.getKind() == NestedNameSpecifier::Kind::MicrosoftSuper)
2710 return LookupInSuper(R, Class: Qualifier.getAsMicrosoftSuper());
2711 return LookupQualifiedName(R, LookupCtx);
2712}
2713
2714bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
2715 QualType ObjectType, bool AllowBuiltinCreation,
2716 bool EnteringContext) {
2717 // When the scope specifier is invalid, don't even look for anything.
2718 if (SS && SS->isInvalid())
2719 return false;
2720
2721 // Determine where to perform name lookup
2722 DeclContext *DC = nullptr;
2723 bool IsDependent = false;
2724 if (!ObjectType.isNull()) {
2725 // This nested-name-specifier occurs in a member access expression, e.g.,
2726 // x->B::f, and we are looking into the type of the object.
2727 assert((!SS || SS->isEmpty()) &&
2728 "ObjectType and scope specifier cannot coexist");
2729 DC = computeDeclContext(T: ObjectType);
2730 IsDependent = !DC && ObjectType->isDependentType();
2731 assert(((!DC && ObjectType->isDependentType()) ||
2732 !ObjectType->isIncompleteType() || !ObjectType->getAs<TagType>() ||
2733 ObjectType->castAs<TagType>()->getDecl()->isEntityBeingDefined()) &&
2734 "Caller should have completed object type");
2735 } else if (SS && SS->isNotEmpty()) {
2736 // This nested-name-specifier occurs after another nested-name-specifier,
2737 // so long into the context associated with the prior nested-name-specifier.
2738 if ((DC = computeDeclContext(SS: *SS, EnteringContext))) {
2739 // The declaration context must be complete.
2740 if (!DC->isDependentContext() && RequireCompleteDeclContext(SS&: *SS, DC))
2741 return false;
2742 R.setContextRange(SS->getRange());
2743 // FIXME: '__super' lookup semantics could be implemented by a
2744 // LookupResult::isSuperLookup flag which skips the initial search of
2745 // the lookup context in LookupQualified.
2746 if (NestedNameSpecifier Qualifier = SS->getScopeRep();
2747 Qualifier.getKind() == NestedNameSpecifier::Kind::MicrosoftSuper)
2748 return LookupInSuper(R, Class: Qualifier.getAsMicrosoftSuper());
2749 }
2750 IsDependent = !DC && isDependentScopeSpecifier(SS: *SS);
2751 } else {
2752 // Perform unqualified name lookup starting in the given scope.
2753 return LookupName(R, S, AllowBuiltinCreation);
2754 }
2755
2756 // If we were able to compute a declaration context, perform qualified name
2757 // lookup in that context.
2758 if (DC)
2759 return LookupQualifiedName(R, LookupCtx: DC);
2760 else if (IsDependent)
2761 // We could not resolve the scope specified to a specific declaration
2762 // context, which means that SS refers to an unknown specialization.
2763 // Name lookup can't find anything in this case.
2764 R.setNotFoundInCurrentInstantiation();
2765 return false;
2766}
2767
2768bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) {
2769 // The access-control rules we use here are essentially the rules for
2770 // doing a lookup in Class that just magically skipped the direct
2771 // members of Class itself. That is, the naming class is Class, and the
2772 // access includes the access of the base.
2773 for (const auto &BaseSpec : Class->bases()) {
2774 auto *RD = BaseSpec.getType()->castAsCXXRecordDecl();
2775 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
2776 Result.setBaseObjectType(Context.getCanonicalTagType(TD: Class));
2777 LookupQualifiedName(R&: Result, LookupCtx: RD);
2778
2779 // Copy the lookup results into the target, merging the base's access into
2780 // the path access.
2781 for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
2782 R.addDecl(D: I.getDecl(),
2783 AS: CXXRecordDecl::MergeAccess(PathAccess: BaseSpec.getAccessSpecifier(),
2784 DeclAccess: I.getAccess()));
2785 }
2786
2787 Result.suppressDiagnostics();
2788 }
2789
2790 R.resolveKind();
2791 R.setNamingClass(Class);
2792
2793 return !R.empty();
2794}
2795
2796void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
2797 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
2798
2799 DeclarationName Name = Result.getLookupName();
2800 SourceLocation NameLoc = Result.getNameLoc();
2801 SourceRange LookupRange = Result.getContextRange();
2802
2803 switch (Result.getAmbiguityKind()) {
2804 case LookupAmbiguityKind::AmbiguousBaseSubobjects: {
2805 CXXBasePaths *Paths = Result.getBasePaths();
2806 QualType SubobjectType = Paths->front().back().Base->getType();
2807 Diag(Loc: NameLoc, DiagID: diag::err_ambiguous_member_multiple_subobjects)
2808 << Name << SubobjectType << getAmbiguousPathsDisplayString(Paths&: *Paths)
2809 << LookupRange;
2810
2811 DeclContext::lookup_iterator Found = Paths->front().Decls;
2812 while (isa<CXXMethodDecl>(Val: *Found) &&
2813 cast<CXXMethodDecl>(Val: *Found)->isStatic())
2814 ++Found;
2815
2816 Diag(Loc: (*Found)->getLocation(), DiagID: diag::note_ambiguous_member_found);
2817 break;
2818 }
2819
2820 case LookupAmbiguityKind::AmbiguousBaseSubobjectTypes: {
2821 Diag(Loc: NameLoc, DiagID: diag::err_ambiguous_member_multiple_subobject_types)
2822 << Name << LookupRange;
2823
2824 CXXBasePaths *Paths = Result.getBasePaths();
2825 std::set<const NamedDecl *> DeclsPrinted;
2826 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
2827 PathEnd = Paths->end();
2828 Path != PathEnd; ++Path) {
2829 const NamedDecl *D = *Path->Decls;
2830 if (!D->isInIdentifierNamespace(NS: Result.getIdentifierNamespace()))
2831 continue;
2832 if (DeclsPrinted.insert(x: D).second) {
2833 if (const auto *TD = dyn_cast<TypedefNameDecl>(Val: D->getUnderlyingDecl()))
2834 Diag(Loc: D->getLocation(), DiagID: diag::note_ambiguous_member_type_found)
2835 << TD->getUnderlyingType();
2836 else if (const auto *TD = dyn_cast<TypeDecl>(Val: D->getUnderlyingDecl()))
2837 Diag(Loc: D->getLocation(), DiagID: diag::note_ambiguous_member_type_found)
2838 << Context.getTypeDeclType(Decl: TD);
2839 else
2840 Diag(Loc: D->getLocation(), DiagID: diag::note_ambiguous_member_found);
2841 }
2842 }
2843 break;
2844 }
2845
2846 case LookupAmbiguityKind::AmbiguousTagHiding: {
2847 Diag(Loc: NameLoc, DiagID: diag::err_ambiguous_tag_hiding) << Name << LookupRange;
2848
2849 llvm::SmallPtrSet<NamedDecl*, 8> TagDecls;
2850
2851 for (auto *D : Result)
2852 if (TagDecl *TD = dyn_cast<TagDecl>(Val: D)) {
2853 TagDecls.insert(Ptr: TD);
2854 Diag(Loc: TD->getLocation(), DiagID: diag::note_hidden_tag);
2855 }
2856
2857 for (auto *D : Result)
2858 if (!isa<TagDecl>(Val: D))
2859 Diag(Loc: D->getLocation(), DiagID: diag::note_hiding_object);
2860
2861 // For recovery purposes, go ahead and implement the hiding.
2862 LookupResult::Filter F = Result.makeFilter();
2863 while (F.hasNext()) {
2864 if (TagDecls.count(Ptr: F.next()))
2865 F.erase();
2866 }
2867 F.done();
2868 break;
2869 }
2870
2871 case LookupAmbiguityKind::AmbiguousReferenceToPlaceholderVariable: {
2872 Diag(Loc: NameLoc, DiagID: diag::err_using_placeholder_variable) << Name << LookupRange;
2873 DeclContext *DC = nullptr;
2874 for (auto *D : Result) {
2875 Diag(Loc: D->getLocation(), DiagID: diag::note_reference_placeholder) << D;
2876 if (DC != nullptr && DC != D->getDeclContext())
2877 break;
2878 DC = D->getDeclContext();
2879 }
2880 break;
2881 }
2882
2883 case LookupAmbiguityKind::AmbiguousReference: {
2884 Diag(Loc: NameLoc, DiagID: diag::err_ambiguous_reference) << Name << LookupRange;
2885
2886 for (auto *D : Result)
2887 Diag(Loc: D->getLocation(), DiagID: diag::note_ambiguous_candidate) << D;
2888 break;
2889 }
2890 }
2891}
2892
2893namespace {
2894 struct AssociatedLookup {
2895 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
2896 Sema::AssociatedNamespaceSet &Namespaces,
2897 Sema::AssociatedClassSet &Classes)
2898 : S(S), Namespaces(Namespaces), Classes(Classes),
2899 InstantiationLoc(InstantiationLoc) {
2900 }
2901
2902 bool addClassTransitive(CXXRecordDecl *RD) {
2903 Classes.insert(X: RD);
2904 return ClassesTransitive.insert(X: RD);
2905 }
2906
2907 Sema &S;
2908 Sema::AssociatedNamespaceSet &Namespaces;
2909 Sema::AssociatedClassSet &Classes;
2910 SourceLocation InstantiationLoc;
2911
2912 private:
2913 Sema::AssociatedClassSet ClassesTransitive;
2914 };
2915} // end anonymous namespace
2916
2917static void
2918addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
2919
2920// Given the declaration context \param Ctx of a class, class template or
2921// enumeration, add the associated namespaces to \param Namespaces as described
2922// in [basic.lookup.argdep]p2.
2923static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces,
2924 DeclContext *Ctx) {
2925 // The exact wording has been changed in C++14 as a result of
2926 // CWG 1691 (see also CWG 1690 and CWG 1692). We apply it unconditionally
2927 // to all language versions since it is possible to return a local type
2928 // from a lambda in C++11.
2929 //
2930 // C++14 [basic.lookup.argdep]p2:
2931 // If T is a class type [...]. Its associated namespaces are the innermost
2932 // enclosing namespaces of its associated classes. [...]
2933 //
2934 // If T is an enumeration type, its associated namespace is the innermost
2935 // enclosing namespace of its declaration. [...]
2936
2937 // We additionally skip inline namespaces. The innermost non-inline namespace
2938 // contains all names of all its nested inline namespaces anyway, so we can
2939 // replace the entire inline namespace tree with its root.
2940 while (!Ctx->isFileContext() || Ctx->isInlineNamespace())
2941 Ctx = Ctx->getParent();
2942
2943 // Actually it is fine to always do `Namespaces.insert(Ctx);` simply. But it
2944 // may cause more allocations in Namespaces and more unnecessary lookups. So
2945 // we'd like to insert the representative namespace only.
2946 DeclContext *PrimaryCtx = Ctx->getPrimaryContext();
2947 Decl *PrimaryD = cast<Decl>(Val: PrimaryCtx);
2948 Decl *D = cast<Decl>(Val: Ctx);
2949 ASTContext &AST = D->getASTContext();
2950
2951 // TODO: Technically it is better to insert one namespace per module. e.g.,
2952 //
2953 // ```
2954 // //--- first.cppm
2955 // export module first;
2956 // namespace ns { ... } // first namespace
2957 //
2958 // //--- m-partA.cppm
2959 // export module m:partA;
2960 // import first;
2961 //
2962 // namespace ns { ... }
2963 // namespace ns { ... }
2964 //
2965 // //--- m-partB.cppm
2966 // export module m:partB;
2967 // import first;
2968 // import :partA;
2969 //
2970 // namespace ns { ... }
2971 // namespace ns { ... }
2972 //
2973 // ...
2974 //
2975 // //--- m-partN.cppm
2976 // export module m:partN;
2977 // import first;
2978 // import :partA;
2979 // ...
2980 // import :part$(N-1);
2981 //
2982 // namespace ns { ... }
2983 // namespace ns { ... }
2984 //
2985 // consume(ns::any_decl); // the lookup
2986 // ```
2987 //
2988 // We should only insert once for all namespaces in module m.
2989 if (D->isInNamedModule() &&
2990 !AST.isInSameModule(M1: D->getOwningModule(), M2: PrimaryD->getOwningModule()))
2991 Namespaces.insert(X: Ctx);
2992 else
2993 Namespaces.insert(X: PrimaryCtx);
2994}
2995
2996// Add the associated classes and namespaces for argument-dependent
2997// lookup that involves a template argument (C++ [basic.lookup.argdep]p2).
2998static void
2999addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
3000 const TemplateArgument &Arg) {
3001 // C++ [basic.lookup.argdep]p2, last bullet:
3002 // -- [...] ;
3003 switch (Arg.getKind()) {
3004 case TemplateArgument::Null:
3005 break;
3006
3007 case TemplateArgument::Type:
3008 // [...] the namespaces and classes associated with the types of the
3009 // template arguments provided for template type parameters (excluding
3010 // template template parameters)
3011 addAssociatedClassesAndNamespaces(Result, T: Arg.getAsType());
3012 break;
3013
3014 case TemplateArgument::Template:
3015 case TemplateArgument::TemplateExpansion: {
3016 // [...] the namespaces in which any template template arguments are
3017 // defined; and the classes in which any member templates used as
3018 // template template arguments are defined.
3019 TemplateName Template = Arg.getAsTemplateOrTemplatePattern();
3020 if (ClassTemplateDecl *ClassTemplate
3021 = dyn_cast<ClassTemplateDecl>(Val: Template.getAsTemplateDecl())) {
3022 DeclContext *Ctx = ClassTemplate->getDeclContext();
3023 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Val: Ctx))
3024 Result.Classes.insert(X: EnclosingClass);
3025 // Add the associated namespace for this class.
3026 CollectEnclosingNamespace(Namespaces&: Result.Namespaces, Ctx);
3027 }
3028 break;
3029 }
3030
3031 case TemplateArgument::Declaration:
3032 case TemplateArgument::Integral:
3033 case TemplateArgument::Expression:
3034 case TemplateArgument::NullPtr:
3035 case TemplateArgument::StructuralValue:
3036 // [Note: non-type template arguments do not contribute to the set of
3037 // associated namespaces. ]
3038 break;
3039
3040 case TemplateArgument::Pack:
3041 for (const auto &P : Arg.pack_elements())
3042 addAssociatedClassesAndNamespaces(Result, Arg: P);
3043 break;
3044 }
3045}
3046
3047// Add the associated classes and namespaces for argument-dependent lookup
3048// with an argument of class type (C++ [basic.lookup.argdep]p2).
3049static void
3050addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
3051 CXXRecordDecl *Class) {
3052
3053 // Just silently ignore anything whose name is __va_list_tag.
3054 if (Class->getDeclName() == Result.S.VAListTagName)
3055 return;
3056
3057 // C++ [basic.lookup.argdep]p2:
3058 // [...]
3059 // -- If T is a class type (including unions), its associated
3060 // classes are: the class itself; the class of which it is a
3061 // member, if any; and its direct and indirect base classes.
3062 // Its associated namespaces are the innermost enclosing
3063 // namespaces of its associated classes.
3064
3065 // Add the class of which it is a member, if any.
3066 DeclContext *Ctx = Class->getDeclContext();
3067 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Val: Ctx))
3068 Result.Classes.insert(X: EnclosingClass);
3069
3070 // Add the associated namespace for this class.
3071 CollectEnclosingNamespace(Namespaces&: Result.Namespaces, Ctx);
3072
3073 // -- If T is a template-id, its associated namespaces and classes are
3074 // the namespace in which the template is defined; for member
3075 // templates, the member template's class; the namespaces and classes
3076 // associated with the types of the template arguments provided for
3077 // template type parameters (excluding template template parameters); the
3078 // namespaces in which any template template arguments are defined; and
3079 // the classes in which any member templates used as template template
3080 // arguments are defined. [Note: non-type template arguments do not
3081 // contribute to the set of associated namespaces. ]
3082 if (ClassTemplateSpecializationDecl *Spec
3083 = dyn_cast<ClassTemplateSpecializationDecl>(Val: Class)) {
3084 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
3085 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Val: Ctx))
3086 Result.Classes.insert(X: EnclosingClass);
3087 // Add the associated namespace for this class.
3088 CollectEnclosingNamespace(Namespaces&: Result.Namespaces, Ctx);
3089
3090 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
3091 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
3092 addAssociatedClassesAndNamespaces(Result, Arg: TemplateArgs[I]);
3093 }
3094
3095 // Add the class itself. If we've already transitively visited this class,
3096 // we don't need to visit base classes.
3097 if (!Result.addClassTransitive(RD: Class))
3098 return;
3099
3100 // Only recurse into base classes for complete types.
3101 if (!Result.S.isCompleteType(Loc: Result.InstantiationLoc,
3102 T: Result.S.Context.getCanonicalTagType(TD: Class)))
3103 return;
3104
3105 // Add direct and indirect base classes along with their associated
3106 // namespaces.
3107 SmallVector<CXXRecordDecl *, 32> Bases;
3108 Bases.push_back(Elt: Class);
3109 while (!Bases.empty()) {
3110 // Pop this class off the stack.
3111 Class = Bases.pop_back_val();
3112
3113 // Visit the base classes.
3114 for (const auto &Base : Class->bases()) {
3115 CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
3116 // In dependent contexts, we do ADL twice, and the first time around,
3117 // the base type might be a dependent TemplateSpecializationType, or a
3118 // TemplateTypeParmType. If that happens, simply ignore it.
3119 // FIXME: If we want to support export, we probably need to add the
3120 // namespace of the template in a TemplateSpecializationType, or even
3121 // the classes and namespaces of known non-dependent arguments.
3122 if (!BaseDecl)
3123 continue;
3124 if (Result.addClassTransitive(RD: BaseDecl)) {
3125 // Find the associated namespace for this base class.
3126 DeclContext *BaseCtx = BaseDecl->getDeclContext();
3127 CollectEnclosingNamespace(Namespaces&: Result.Namespaces, Ctx: BaseCtx);
3128
3129 // Make sure we visit the bases of this base class.
3130 if (!BaseDecl->bases().empty())
3131 Bases.push_back(Elt: BaseDecl);
3132 }
3133 }
3134 }
3135}
3136
3137// Add the associated classes and namespaces for
3138// argument-dependent lookup with an argument of type T
3139// (C++ [basic.lookup.koenig]p2).
3140static void
3141addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
3142 // C++ [basic.lookup.koenig]p2:
3143 //
3144 // For each argument type T in the function call, there is a set
3145 // of zero or more associated namespaces and a set of zero or more
3146 // associated classes to be considered. The sets of namespaces and
3147 // classes is determined entirely by the types of the function
3148 // arguments (and the namespace of any template template
3149 // argument). Typedef names and using-declarations used to specify
3150 // the types do not contribute to this set. The sets of namespaces
3151 // and classes are determined in the following way:
3152
3153 SmallVector<const Type *, 16> Queue;
3154 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
3155
3156 while (true) {
3157 switch (T->getTypeClass()) {
3158
3159#define TYPE(Class, Base)
3160#define DEPENDENT_TYPE(Class, Base) case Type::Class:
3161#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
3162#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
3163#define ABSTRACT_TYPE(Class, Base)
3164#include "clang/AST/TypeNodes.inc"
3165 // T is canonical. We can also ignore dependent types because
3166 // we don't need to do ADL at the definition point, but if we
3167 // wanted to implement template export (or if we find some other
3168 // use for associated classes and namespaces...) this would be
3169 // wrong.
3170 break;
3171
3172 // -- If T is a pointer to U or an array of U, its associated
3173 // namespaces and classes are those associated with U.
3174 case Type::Pointer:
3175 T = cast<PointerType>(Val: T)->getPointeeType().getTypePtr();
3176 continue;
3177 case Type::ConstantArray:
3178 case Type::IncompleteArray:
3179 case Type::VariableArray:
3180 T = cast<ArrayType>(Val: T)->getElementType().getTypePtr();
3181 continue;
3182
3183 // -- If T is a fundamental type, its associated sets of
3184 // namespaces and classes are both empty.
3185 case Type::Builtin:
3186 break;
3187
3188 // -- If T is a class type (including unions), its associated
3189 // classes are: the class itself; the class of which it is
3190 // a member, if any; and its direct and indirect base classes.
3191 // Its associated namespaces are the innermost enclosing
3192 // namespaces of its associated classes.
3193 case Type::Record: {
3194 // FIXME: This should use the original decl.
3195 auto *Class = cast<CXXRecordDecl>(Val: cast<RecordType>(Val: T)->getDecl())
3196 ->getDefinitionOrSelf();
3197 addAssociatedClassesAndNamespaces(Result, Class);
3198 break;
3199 }
3200
3201 // -- If T is an enumeration type, its associated namespace
3202 // is the innermost enclosing namespace of its declaration.
3203 // If it is a class member, its associated class is the
3204 // member’s class; else it has no associated class.
3205 case Type::Enum: {
3206 // FIXME: This should use the original decl.
3207 auto *Enum = T->castAsEnumDecl();
3208
3209 DeclContext *Ctx = Enum->getDeclContext();
3210 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Val: Ctx))
3211 Result.Classes.insert(X: EnclosingClass);
3212
3213 // Add the associated namespace for this enumeration.
3214 CollectEnclosingNamespace(Namespaces&: Result.Namespaces, Ctx);
3215
3216 break;
3217 }
3218
3219 // -- If T is a function type, its associated namespaces and
3220 // classes are those associated with the function parameter
3221 // types and those associated with the return type.
3222 case Type::FunctionProto: {
3223 const FunctionProtoType *Proto = cast<FunctionProtoType>(Val: T);
3224 for (const auto &Arg : Proto->param_types())
3225 Queue.push_back(Elt: Arg.getTypePtr());
3226 // fallthrough
3227 [[fallthrough]];
3228 }
3229 case Type::FunctionNoProto: {
3230 const FunctionType *FnType = cast<FunctionType>(Val: T);
3231 T = FnType->getReturnType().getTypePtr();
3232 continue;
3233 }
3234
3235 // -- If T is a pointer to a member function of a class X, its
3236 // associated namespaces and classes are those associated
3237 // with the function parameter types and return type,
3238 // together with those associated with X.
3239 //
3240 // -- If T is a pointer to a data member of class X, its
3241 // associated namespaces and classes are those associated
3242 // with the member type together with those associated with
3243 // X.
3244 case Type::MemberPointer: {
3245 const MemberPointerType *MemberPtr = cast<MemberPointerType>(Val: T);
3246 if (CXXRecordDecl *Class = MemberPtr->getMostRecentCXXRecordDecl())
3247 addAssociatedClassesAndNamespaces(Result, Class);
3248 T = MemberPtr->getPointeeType().getTypePtr();
3249 continue;
3250 }
3251
3252 // As an extension, treat this like a normal pointer.
3253 case Type::BlockPointer:
3254 T = cast<BlockPointerType>(Val: T)->getPointeeType().getTypePtr();
3255 continue;
3256
3257 // References aren't covered by the standard, but that's such an
3258 // obvious defect that we cover them anyway.
3259 case Type::LValueReference:
3260 case Type::RValueReference:
3261 T = cast<ReferenceType>(Val: T)->getPointeeType().getTypePtr();
3262 continue;
3263
3264 // These are fundamental types.
3265 case Type::Vector:
3266 case Type::ExtVector:
3267 case Type::ConstantMatrix:
3268 case Type::Complex:
3269 case Type::BitInt:
3270 break;
3271
3272 // Non-deduced auto types only get here for error cases.
3273 case Type::Auto:
3274 case Type::DeducedTemplateSpecialization:
3275 break;
3276
3277 // If T is an Objective-C object or interface type, or a pointer to an
3278 // object or interface type, the associated namespace is the global
3279 // namespace.
3280 case Type::ObjCObject:
3281 case Type::ObjCInterface:
3282 case Type::ObjCObjectPointer:
3283 Result.Namespaces.insert(X: Result.S.Context.getTranslationUnitDecl());
3284 break;
3285
3286 // Atomic types are just wrappers; use the associations of the
3287 // contained type.
3288 case Type::Atomic:
3289 T = cast<AtomicType>(Val: T)->getValueType().getTypePtr();
3290 continue;
3291 case Type::Pipe:
3292 T = cast<PipeType>(Val: T)->getElementType().getTypePtr();
3293 continue;
3294
3295 // Array parameter types are treated as fundamental types.
3296 case Type::ArrayParameter:
3297 break;
3298
3299 case Type::HLSLAttributedResource:
3300 T = cast<HLSLAttributedResourceType>(Val: T)->getWrappedType().getTypePtr();
3301 break;
3302
3303 // Inline SPIR-V types are treated as fundamental types.
3304 case Type::HLSLInlineSpirv:
3305 break;
3306 case Type::OverflowBehavior:
3307 T = cast<OverflowBehaviorType>(Val: T)->getUnderlyingType().getTypePtr();
3308 }
3309
3310 if (Queue.empty())
3311 break;
3312 T = Queue.pop_back_val();
3313 }
3314}
3315
3316void Sema::FindAssociatedClassesAndNamespaces(
3317 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
3318 AssociatedNamespaceSet &AssociatedNamespaces,
3319 AssociatedClassSet &AssociatedClasses) {
3320 AssociatedNamespaces.clear();
3321 AssociatedClasses.clear();
3322
3323 AssociatedLookup Result(*this, InstantiationLoc,
3324 AssociatedNamespaces, AssociatedClasses);
3325
3326 // C++ [basic.lookup.koenig]p2:
3327 // For each argument type T in the function call, there is a set
3328 // of zero or more associated namespaces and a set of zero or more
3329 // associated classes to be considered. The sets of namespaces and
3330 // classes is determined entirely by the types of the function
3331 // arguments (and the namespace of any template template
3332 // argument).
3333 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
3334 Expr *Arg = Args[ArgIdx];
3335
3336 if (Arg->getType() != Context.OverloadTy) {
3337 addAssociatedClassesAndNamespaces(Result, Ty: Arg->getType());
3338 continue;
3339 }
3340
3341 // [...] In addition, if the argument is the name or address of a
3342 // set of overloaded functions and/or function templates, its
3343 // associated classes and namespaces are the union of those
3344 // associated with each of the members of the set: the namespace
3345 // in which the function or function template is defined and the
3346 // classes and namespaces associated with its (non-dependent)
3347 // parameter types and return type.
3348 OverloadExpr *OE = OverloadExpr::find(E: Arg).Expression;
3349
3350 for (const NamedDecl *D : OE->decls()) {
3351 // Look through any using declarations to find the underlying function.
3352 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
3353
3354 // Add the classes and namespaces associated with the parameter
3355 // types and return type of this function.
3356 addAssociatedClassesAndNamespaces(Result, Ty: FDecl->getType());
3357 }
3358 }
3359}
3360
3361NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
3362 SourceLocation Loc,
3363 LookupNameKind NameKind,
3364 RedeclarationKind Redecl) {
3365 LookupResult R(*this, Name, Loc, NameKind, Redecl);
3366 LookupName(R, S);
3367 return R.getAsSingle<NamedDecl>();
3368}
3369
3370void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
3371 UnresolvedSetImpl &Functions) {
3372 // C++ [over.match.oper]p3:
3373 // -- The set of non-member candidates is the result of the
3374 // unqualified lookup of operator@ in the context of the
3375 // expression according to the usual rules for name lookup in
3376 // unqualified function calls (3.4.2) except that all member
3377 // functions are ignored.
3378 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
3379 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
3380 LookupName(R&: Operators, S);
3381
3382 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
3383 Functions.append(I: Operators.begin(), E: Operators.end());
3384}
3385
3386Sema::SpecialMemberOverloadResult
3387Sema::LookupSpecialMember(CXXRecordDecl *RD, CXXSpecialMemberKind SM,
3388 bool ConstArg, bool VolatileArg, bool RValueThis,
3389 bool ConstThis, bool VolatileThis) {
3390 assert(CanDeclareSpecialMemberFunction(RD) &&
3391 "doing special member lookup into record that isn't fully complete");
3392 RD = RD->getDefinition();
3393 if (RValueThis || ConstThis || VolatileThis)
3394 assert((SM == CXXSpecialMemberKind::CopyAssignment ||
3395 SM == CXXSpecialMemberKind::MoveAssignment) &&
3396 "constructors and destructors always have unqualified lvalue this");
3397 if (ConstArg || VolatileArg)
3398 assert((SM != CXXSpecialMemberKind::DefaultConstructor &&
3399 SM != CXXSpecialMemberKind::Destructor) &&
3400 "parameter-less special members can't have qualified arguments");
3401
3402 // FIXME: Get the caller to pass in a location for the lookup.
3403 SourceLocation LookupLoc = RD->getLocation();
3404
3405 llvm::FoldingSetNodeID ID;
3406 ID.AddPointer(Ptr: RD);
3407 ID.AddInteger(I: llvm::to_underlying(E: SM));
3408 ID.AddInteger(I: ConstArg);
3409 ID.AddInteger(I: VolatileArg);
3410 ID.AddInteger(I: RValueThis);
3411 ID.AddInteger(I: ConstThis);
3412 ID.AddInteger(I: VolatileThis);
3413
3414 void *InsertPoint;
3415 SpecialMemberOverloadResultEntry *Result =
3416 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPos&: InsertPoint);
3417
3418 // This was already cached
3419 if (Result)
3420 return *Result;
3421
3422 Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>();
3423 Result = new (Result) SpecialMemberOverloadResultEntry(ID);
3424 SpecialMemberCache.InsertNode(N: Result, InsertPos: InsertPoint);
3425
3426 if (SM == CXXSpecialMemberKind::Destructor) {
3427 if (RD->needsImplicitDestructor()) {
3428 runWithSufficientStackSpace(Loc: RD->getLocation(), Fn: [&] {
3429 DeclareImplicitDestructor(ClassDecl: RD);
3430 });
3431 }
3432 CXXDestructorDecl *DD = RD->getDestructor();
3433 Result->setMethod(DD);
3434 Result->setKind(DD && !DD->isDeleted()
3435 ? SpecialMemberOverloadResult::Success
3436 : SpecialMemberOverloadResult::NoMemberOrDeleted);
3437 return *Result;
3438 }
3439
3440 // Prepare for overload resolution. Here we construct a synthetic argument
3441 // if necessary and make sure that implicit functions are declared.
3442 CanQualType CanTy = Context.getCanonicalTagType(TD: RD);
3443 DeclarationName Name;
3444 Expr *Arg = nullptr;
3445 unsigned NumArgs;
3446
3447 QualType ArgType = CanTy;
3448 ExprValueKind VK = VK_LValue;
3449
3450 if (SM == CXXSpecialMemberKind::DefaultConstructor) {
3451 Name = Context.DeclarationNames.getCXXConstructorName(Ty: CanTy);
3452 NumArgs = 0;
3453 if (RD->needsImplicitDefaultConstructor()) {
3454 runWithSufficientStackSpace(Loc: RD->getLocation(), Fn: [&] {
3455 DeclareImplicitDefaultConstructor(ClassDecl: RD);
3456 });
3457 }
3458 } else {
3459 if (SM == CXXSpecialMemberKind::CopyConstructor ||
3460 SM == CXXSpecialMemberKind::MoveConstructor) {
3461 Name = Context.DeclarationNames.getCXXConstructorName(Ty: CanTy);
3462 if (RD->needsImplicitCopyConstructor()) {
3463 runWithSufficientStackSpace(Loc: RD->getLocation(), Fn: [&] {
3464 DeclareImplicitCopyConstructor(ClassDecl: RD);
3465 });
3466 }
3467 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor()) {
3468 runWithSufficientStackSpace(Loc: RD->getLocation(), Fn: [&] {
3469 DeclareImplicitMoveConstructor(ClassDecl: RD);
3470 });
3471 }
3472 } else {
3473 Name = Context.DeclarationNames.getCXXOperatorName(Op: OO_Equal);
3474 if (RD->needsImplicitCopyAssignment()) {
3475 runWithSufficientStackSpace(Loc: RD->getLocation(), Fn: [&] {
3476 DeclareImplicitCopyAssignment(ClassDecl: RD);
3477 });
3478 }
3479 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment()) {
3480 runWithSufficientStackSpace(Loc: RD->getLocation(), Fn: [&] {
3481 DeclareImplicitMoveAssignment(ClassDecl: RD);
3482 });
3483 }
3484 }
3485
3486 if (ConstArg)
3487 ArgType.addConst();
3488 if (VolatileArg)
3489 ArgType.addVolatile();
3490
3491 // This isn't /really/ specified by the standard, but it's implied
3492 // we should be working from a PRValue in the case of move to ensure
3493 // that we prefer to bind to rvalue references, and an LValue in the
3494 // case of copy to ensure we don't bind to rvalue references.
3495 // Possibly an XValue is actually correct in the case of move, but
3496 // there is no semantic difference for class types in this restricted
3497 // case.
3498 if (SM == CXXSpecialMemberKind::CopyConstructor ||
3499 SM == CXXSpecialMemberKind::CopyAssignment)
3500 VK = VK_LValue;
3501 else
3502 VK = VK_PRValue;
3503 }
3504
3505 OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK);
3506
3507 if (SM != CXXSpecialMemberKind::DefaultConstructor) {
3508 NumArgs = 1;
3509 Arg = &FakeArg;
3510 }
3511
3512 // Create the object argument
3513 QualType ThisTy = CanTy;
3514 if (ConstThis)
3515 ThisTy.addConst();
3516 if (VolatileThis)
3517 ThisTy.addVolatile();
3518 Expr::Classification Classification =
3519 OpaqueValueExpr(LookupLoc, ThisTy, RValueThis ? VK_PRValue : VK_LValue)
3520 .Classify(Ctx&: Context);
3521
3522 // Now we perform lookup on the name we computed earlier and do overload
3523 // resolution. Lookup is only performed directly into the class since there
3524 // will always be a (possibly implicit) declaration to shadow any others.
3525 OverloadCandidateSet OCS(LookupLoc, OverloadCandidateSet::CSK_Normal);
3526 DeclContext::lookup_result R = RD->lookup(Name);
3527
3528 if (R.empty()) {
3529 // We might have no default constructor because we have a lambda's closure
3530 // type, rather than because there's some other declared constructor.
3531 // Every class has a copy/move constructor, copy/move assignment, and
3532 // destructor.
3533 assert(SM == CXXSpecialMemberKind::DefaultConstructor &&
3534 "lookup for a constructor or assignment operator was empty");
3535 Result->setMethod(nullptr);
3536 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3537 return *Result;
3538 }
3539
3540 // Copy the candidates as our processing of them may load new declarations
3541 // from an external source and invalidate lookup_result.
3542 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
3543
3544 for (NamedDecl *CandDecl : Candidates) {
3545 if (CandDecl->isInvalidDecl())
3546 continue;
3547
3548 DeclAccessPair Cand = DeclAccessPair::make(D: CandDecl, AS: AS_public);
3549 auto CtorInfo = getConstructorInfo(ND: Cand);
3550 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Val: Cand->getUnderlyingDecl())) {
3551 if (SM == CXXSpecialMemberKind::CopyAssignment ||
3552 SM == CXXSpecialMemberKind::MoveAssignment)
3553 AddMethodCandidate(Method: M, FoundDecl: Cand, ActingContext: RD, ObjectType: ThisTy, ObjectClassification: Classification,
3554 Args: llvm::ArrayRef(&Arg, NumArgs), CandidateSet&: OCS, SuppressUserConversions: true);
3555 else if (CtorInfo)
3556 AddOverloadCandidate(Function: CtorInfo.Constructor, FoundDecl: CtorInfo.FoundDecl,
3557 Args: llvm::ArrayRef(&Arg, NumArgs), CandidateSet&: OCS,
3558 /*SuppressUserConversions*/ true);
3559 else
3560 AddOverloadCandidate(Function: M, FoundDecl: Cand, Args: llvm::ArrayRef(&Arg, NumArgs), CandidateSet&: OCS,
3561 /*SuppressUserConversions*/ true);
3562 } else if (FunctionTemplateDecl *Tmpl =
3563 dyn_cast<FunctionTemplateDecl>(Val: Cand->getUnderlyingDecl())) {
3564 if (SM == CXXSpecialMemberKind::CopyAssignment ||
3565 SM == CXXSpecialMemberKind::MoveAssignment)
3566 AddMethodTemplateCandidate(MethodTmpl: Tmpl, FoundDecl: Cand, ActingContext: RD, ExplicitTemplateArgs: nullptr, ObjectType: ThisTy,
3567 ObjectClassification: Classification,
3568 Args: llvm::ArrayRef(&Arg, NumArgs), CandidateSet&: OCS, SuppressUserConversions: true);
3569 else if (CtorInfo)
3570 AddTemplateOverloadCandidate(FunctionTemplate: CtorInfo.ConstructorTmpl,
3571 FoundDecl: CtorInfo.FoundDecl, ExplicitTemplateArgs: nullptr,
3572 Args: llvm::ArrayRef(&Arg, NumArgs), CandidateSet&: OCS, SuppressUserConversions: true);
3573 else
3574 AddTemplateOverloadCandidate(FunctionTemplate: Tmpl, FoundDecl: Cand, ExplicitTemplateArgs: nullptr,
3575 Args: llvm::ArrayRef(&Arg, NumArgs), CandidateSet&: OCS, SuppressUserConversions: true);
3576 } else {
3577 assert(isa<UsingDecl>(Cand.getDecl()) &&
3578 "illegal Kind of operator = Decl");
3579 }
3580 }
3581
3582 OverloadCandidateSet::iterator Best;
3583 switch (OCS.BestViableFunction(S&: *this, Loc: LookupLoc, Best)) {
3584 case OR_Success:
3585 Result->setMethod(cast<CXXMethodDecl>(Val: Best->Function));
3586 Result->setKind(SpecialMemberOverloadResult::Success);
3587 break;
3588
3589 case OR_Deleted:
3590 Result->setMethod(cast<CXXMethodDecl>(Val: Best->Function));
3591 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3592 break;
3593
3594 case OR_Ambiguous:
3595 Result->setMethod(nullptr);
3596 Result->setKind(SpecialMemberOverloadResult::Ambiguous);
3597 break;
3598
3599 case OR_No_Viable_Function:
3600 Result->setMethod(nullptr);
3601 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3602 break;
3603 }
3604
3605 return *Result;
3606}
3607
3608CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) {
3609 SpecialMemberOverloadResult Result =
3610 LookupSpecialMember(RD: Class, SM: CXXSpecialMemberKind::DefaultConstructor,
3611 ConstArg: false, VolatileArg: false, RValueThis: false, ConstThis: false, VolatileThis: false);
3612
3613 return cast_or_null<CXXConstructorDecl>(Val: Result.getMethod());
3614}
3615
3616CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class,
3617 unsigned Quals) {
3618 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3619 "non-const, non-volatile qualifiers for copy ctor arg");
3620 SpecialMemberOverloadResult Result = LookupSpecialMember(
3621 RD: Class, SM: CXXSpecialMemberKind::CopyConstructor, ConstArg: Quals & Qualifiers::Const,
3622 VolatileArg: Quals & Qualifiers::Volatile, RValueThis: false, ConstThis: false, VolatileThis: false);
3623
3624 return cast_or_null<CXXConstructorDecl>(Val: Result.getMethod());
3625}
3626
3627CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class,
3628 unsigned Quals) {
3629 SpecialMemberOverloadResult Result = LookupSpecialMember(
3630 RD: Class, SM: CXXSpecialMemberKind::MoveConstructor, ConstArg: Quals & Qualifiers::Const,
3631 VolatileArg: Quals & Qualifiers::Volatile, RValueThis: false, ConstThis: false, VolatileThis: false);
3632
3633 return cast_or_null<CXXConstructorDecl>(Val: Result.getMethod());
3634}
3635
3636DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) {
3637 // If the implicit constructors have not yet been declared, do so now.
3638 if (CanDeclareSpecialMemberFunction(Class)) {
3639 runWithSufficientStackSpace(Loc: Class->getLocation(), Fn: [&] {
3640 if (Class->needsImplicitDefaultConstructor())
3641 DeclareImplicitDefaultConstructor(ClassDecl: Class);
3642 if (Class->needsImplicitCopyConstructor())
3643 DeclareImplicitCopyConstructor(ClassDecl: Class);
3644 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
3645 DeclareImplicitMoveConstructor(ClassDecl: Class);
3646 });
3647 }
3648
3649 CanQualType T = Context.getCanonicalTagType(TD: Class);
3650 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(Ty: T);
3651 return Class->lookup(Name);
3652}
3653
3654CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class,
3655 unsigned Quals, bool RValueThis,
3656 unsigned ThisQuals) {
3657 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3658 "non-const, non-volatile qualifiers for copy assignment arg");
3659 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3660 "non-const, non-volatile qualifiers for copy assignment this");
3661 SpecialMemberOverloadResult Result = LookupSpecialMember(
3662 RD: Class, SM: CXXSpecialMemberKind::CopyAssignment, ConstArg: Quals & Qualifiers::Const,
3663 VolatileArg: Quals & Qualifiers::Volatile, RValueThis, ConstThis: ThisQuals & Qualifiers::Const,
3664 VolatileThis: ThisQuals & Qualifiers::Volatile);
3665
3666 return Result.getMethod();
3667}
3668
3669CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class,
3670 unsigned Quals,
3671 bool RValueThis,
3672 unsigned ThisQuals) {
3673 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3674 "non-const, non-volatile qualifiers for copy assignment this");
3675 SpecialMemberOverloadResult Result = LookupSpecialMember(
3676 RD: Class, SM: CXXSpecialMemberKind::MoveAssignment, ConstArg: Quals & Qualifiers::Const,
3677 VolatileArg: Quals & Qualifiers::Volatile, RValueThis, ConstThis: ThisQuals & Qualifiers::Const,
3678 VolatileThis: ThisQuals & Qualifiers::Volatile);
3679
3680 return Result.getMethod();
3681}
3682
3683CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) {
3684 return cast_or_null<CXXDestructorDecl>(
3685 Val: LookupSpecialMember(RD: Class, SM: CXXSpecialMemberKind::Destructor, ConstArg: false, VolatileArg: false,
3686 RValueThis: false, ConstThis: false, VolatileThis: false)
3687 .getMethod());
3688}
3689
3690Sema::LiteralOperatorLookupResult
3691Sema::LookupLiteralOperator(Scope *S, LookupResult &R,
3692 ArrayRef<QualType> ArgTys, bool AllowRaw,
3693 bool AllowTemplate, bool AllowStringTemplatePack,
3694 bool DiagnoseMissing, StringLiteral *StringLit) {
3695 LookupName(R, S);
3696 assert(R.getResultKind() != LookupResultKind::Ambiguous &&
3697 "literal operator lookup can't be ambiguous");
3698
3699 // Filter the lookup results appropriately.
3700 LookupResult::Filter F = R.makeFilter();
3701
3702 bool AllowCooked = true;
3703 bool FoundRaw = false;
3704 bool FoundTemplate = false;
3705 bool FoundStringTemplatePack = false;
3706 bool FoundCooked = false;
3707
3708 while (F.hasNext()) {
3709 Decl *D = F.next();
3710 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(Val: D))
3711 D = USD->getTargetDecl();
3712
3713 // If the declaration we found is invalid, skip it.
3714 if (D->isInvalidDecl()) {
3715 F.erase();
3716 continue;
3717 }
3718
3719 bool IsRaw = false;
3720 bool IsTemplate = false;
3721 bool IsStringTemplatePack = false;
3722 bool IsCooked = false;
3723
3724 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: D)) {
3725 if (FD->getNumParams() == 1 &&
3726 FD->getParamDecl(i: 0)->getType()->getAs<PointerType>())
3727 IsRaw = true;
3728 else if (FD->getNumParams() == ArgTys.size()) {
3729 IsCooked = true;
3730 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
3731 QualType ParamTy = FD->getParamDecl(i: ArgIdx)->getType();
3732 if (!Context.hasSameUnqualifiedType(T1: ArgTys[ArgIdx], T2: ParamTy)) {
3733 IsCooked = false;
3734 break;
3735 }
3736 }
3737 }
3738 }
3739 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(Val: D)) {
3740 TemplateParameterList *Params = FD->getTemplateParameters();
3741 if (Params->size() == 1) {
3742 IsTemplate = true;
3743 if (!Params->getParam(Idx: 0)->isTemplateParameterPack() && !StringLit) {
3744 // Implied but not stated: user-defined integer and floating literals
3745 // only ever use numeric literal operator templates, not templates
3746 // taking a parameter of class type.
3747 F.erase();
3748 continue;
3749 }
3750
3751 // A string literal template is only considered if the string literal
3752 // is a well-formed template argument for the template parameter.
3753 if (StringLit) {
3754 SFINAETrap Trap(*this);
3755 CheckTemplateArgumentInfo CTAI;
3756 TemplateArgumentLoc Arg(
3757 TemplateArgument(StringLit, /*IsCanonical=*/false), StringLit);
3758 if (CheckTemplateArgument(
3759 Param: Params->getParam(Idx: 0), Arg, Template: FD, TemplateLoc: R.getNameLoc(), RAngleLoc: R.getNameLoc(),
3760 /*ArgumentPackIndex=*/0, CTAI, CTAK: CTAK_Specified) ||
3761 Trap.hasErrorOccurred())
3762 IsTemplate = false;
3763 }
3764 } else {
3765 IsStringTemplatePack = true;
3766 }
3767 }
3768
3769 if (AllowTemplate && StringLit && IsTemplate) {
3770 FoundTemplate = true;
3771 AllowRaw = false;
3772 AllowCooked = false;
3773 AllowStringTemplatePack = false;
3774 if (FoundRaw || FoundCooked || FoundStringTemplatePack) {
3775 F.restart();
3776 FoundRaw = FoundCooked = FoundStringTemplatePack = false;
3777 }
3778 } else if (AllowCooked && IsCooked) {
3779 FoundCooked = true;
3780 AllowRaw = false;
3781 AllowTemplate = StringLit;
3782 AllowStringTemplatePack = false;
3783 if (FoundRaw || FoundTemplate || FoundStringTemplatePack) {
3784 // Go through again and remove the raw and template decls we've
3785 // already found.
3786 F.restart();
3787 FoundRaw = FoundTemplate = FoundStringTemplatePack = false;
3788 }
3789 } else if (AllowRaw && IsRaw) {
3790 FoundRaw = true;
3791 } else if (AllowTemplate && IsTemplate) {
3792 FoundTemplate = true;
3793 } else if (AllowStringTemplatePack && IsStringTemplatePack) {
3794 FoundStringTemplatePack = true;
3795 } else {
3796 F.erase();
3797 }
3798 }
3799
3800 F.done();
3801
3802 // Per C++20 [lex.ext]p5, we prefer the template form over the non-template
3803 // form for string literal operator templates.
3804 if (StringLit && FoundTemplate)
3805 return LOLR_Template;
3806
3807 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
3808 // parameter type, that is used in preference to a raw literal operator
3809 // or literal operator template.
3810 if (FoundCooked)
3811 return LOLR_Cooked;
3812
3813 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
3814 // operator template, but not both.
3815 if (FoundRaw && FoundTemplate) {
3816 Diag(Loc: R.getNameLoc(), DiagID: diag::err_ovl_ambiguous_call) << R.getLookupName();
3817 for (const NamedDecl *D : R)
3818 NoteOverloadCandidate(Found: D, Fn: D->getUnderlyingDecl()->getAsFunction());
3819 return LOLR_Error;
3820 }
3821
3822 if (FoundRaw)
3823 return LOLR_Raw;
3824
3825 if (FoundTemplate)
3826 return LOLR_Template;
3827
3828 if (FoundStringTemplatePack)
3829 return LOLR_StringTemplatePack;
3830
3831 // Didn't find anything we could use.
3832 if (DiagnoseMissing) {
3833 Diag(Loc: R.getNameLoc(), DiagID: diag::err_ovl_no_viable_literal_operator)
3834 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
3835 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
3836 << (AllowTemplate || AllowStringTemplatePack);
3837 return LOLR_Error;
3838 }
3839
3840 return LOLR_ErrorNoDiagnostic;
3841}
3842
3843void ADLResult::insert(NamedDecl *New) {
3844 NamedDecl *&Old = Decls[cast<NamedDecl>(Val: New->getCanonicalDecl())];
3845
3846 // If we haven't yet seen a decl for this key, or the last decl
3847 // was exactly this one, we're done.
3848 if (Old == nullptr || Old == New) {
3849 Old = New;
3850 return;
3851 }
3852
3853 // Otherwise, decide which is a more recent redeclaration.
3854 FunctionDecl *OldFD = Old->getAsFunction();
3855 FunctionDecl *NewFD = New->getAsFunction();
3856
3857 FunctionDecl *Cursor = NewFD;
3858 while (true) {
3859 Cursor = Cursor->getPreviousDecl();
3860
3861 // If we got to the end without finding OldFD, OldFD is the newer
3862 // declaration; leave things as they are.
3863 if (!Cursor) return;
3864
3865 // If we do find OldFD, then NewFD is newer.
3866 if (Cursor == OldFD) break;
3867
3868 // Otherwise, keep looking.
3869 }
3870
3871 Old = New;
3872}
3873
3874void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
3875 ArrayRef<Expr *> Args, ADLResult &Result) {
3876 // Find all of the associated namespaces and classes based on the
3877 // arguments we have.
3878 AssociatedNamespaceSet AssociatedNamespaces;
3879 AssociatedClassSet AssociatedClasses;
3880 FindAssociatedClassesAndNamespaces(InstantiationLoc: Loc, Args,
3881 AssociatedNamespaces,
3882 AssociatedClasses);
3883
3884 // Load the friend classes in case there are unloaded decls.
3885 //
3886 // FIXME: Currently this is inefficient if there are a lot of friends
3887 // in the classes. We just expect the number of friends are limited
3888 // in real world. In case we meet the case that the loading friends
3889 // became a threshold, we can change the structure of friends from
3890 // a list to a name lookup table.
3891 for (CXXRecordDecl *Class : AssociatedClasses)
3892 if (Class->hasDefinition() && Class->hasLazyFriends())
3893 Class->loadLazyFriends();
3894
3895 // C++ [basic.lookup.argdep]p3:
3896 // Let X be the lookup set produced by unqualified lookup (3.4.1)
3897 // and let Y be the lookup set produced by argument dependent
3898 // lookup (defined as follows). If X contains [...] then Y is
3899 // empty. Otherwise Y is the set of declarations found in the
3900 // namespaces associated with the argument types as described
3901 // below. The set of declarations found by the lookup of the name
3902 // is the union of X and Y.
3903 //
3904 // Here, we compute Y and add its members to the overloaded
3905 // candidate set.
3906 for (auto *NS : AssociatedNamespaces) {
3907 // When considering an associated namespace, the lookup is the
3908 // same as the lookup performed when the associated namespace is
3909 // used as a qualifier (3.4.3.2) except that:
3910 //
3911 // -- Any using-directives in the associated namespace are
3912 // ignored.
3913 //
3914 // -- Any namespace-scope friend functions declared in
3915 // associated classes are visible within their respective
3916 // namespaces even if they are not visible during an ordinary
3917 // lookup (11.4).
3918 //
3919 // C++20 [basic.lookup.argdep] p4.3
3920 // -- are exported, are attached to a named module M, do not appear
3921 // in the translation unit containing the point of the lookup, and
3922 // have the same innermost enclosing non-inline namespace scope as
3923 // a declaration of an associated entity attached to M.
3924 DeclContext::lookup_result R = NS->lookup(Name);
3925 for (auto *D : R) {
3926 auto *Underlying = D;
3927 if (auto *USD = dyn_cast<UsingShadowDecl>(Val: D))
3928 Underlying = USD->getTargetDecl();
3929
3930 if (!isa<FunctionDecl>(Val: Underlying) &&
3931 !isa<FunctionTemplateDecl>(Val: Underlying))
3932 continue;
3933
3934 // The declaration is visible to argument-dependent lookup if either
3935 // it's ordinarily visible or declared as a friend in an associated
3936 // class.
3937 bool Visible = false;
3938 for (D = D->getMostRecentDecl(); D;
3939 D = cast_or_null<NamedDecl>(Val: D->getPreviousDecl())) {
3940 if (D->getIdentifierNamespace() & Decl::IDNS_Ordinary) {
3941 if (isVisible(D)) {
3942 Visible = true;
3943 break;
3944 }
3945
3946 if (!D->getOwningModule() ||
3947 !D->getOwningModule()->getTopLevelModule()->isNamedModule())
3948 continue;
3949
3950 if (D->isInExportDeclContext()) {
3951 Module *FM = D->getOwningModule();
3952 // C++20 [basic.lookup.argdep] p4.3 .. are exported ...
3953 // exports are only valid in module purview and outside of any
3954 // PMF (although a PMF should not even be present in a module
3955 // with an import).
3956 assert(FM &&
3957 (FM->isNamedModule() || FM->isImplicitGlobalModule()) &&
3958 !FM->isPrivateModule() && "bad export context");
3959 // .. are attached to a named module M, do not appear in the
3960 // translation unit containing the point of the lookup..
3961 if (D->isInAnotherModuleUnit() &&
3962 llvm::any_of(Range&: AssociatedClasses, P: [&](auto *E) {
3963 // ... and have the same innermost enclosing non-inline
3964 // namespace scope as a declaration of an associated entity
3965 // attached to M
3966 if (E->getOwningModule() != FM)
3967 return false;
3968 // TODO: maybe this could be cached when generating the
3969 // associated namespaces / entities.
3970 DeclContext *Ctx = E->getDeclContext();
3971 while (!Ctx->isFileContext() || Ctx->isInlineNamespace())
3972 Ctx = Ctx->getParent();
3973 return Ctx == NS;
3974 })) {
3975 Visible = true;
3976 break;
3977 }
3978 }
3979 }
3980
3981 if (D->getFriendObjectKind()) {
3982 auto *RD = cast<CXXRecordDecl>(Val: D->getLexicalDeclContext());
3983 // [basic.lookup.argdep]p4:
3984 // Argument-dependent lookup finds all declarations of functions and
3985 // function templates that
3986 // - ...
3987 // - are declared as a friend ([class.friend]) of any class with a
3988 // reachable definition in the set of associated entities,
3989 //
3990 // FIXME: If there's a merged definition of D that is reachable, then
3991 // the friend declaration should be considered.
3992 if (AssociatedClasses.count(key: RD) && isReachable(D)) {
3993 Visible = true;
3994 break;
3995 }
3996 }
3997 }
3998
3999 // FIXME: Preserve D as the FoundDecl.
4000 if (Visible)
4001 Result.insert(New: Underlying);
4002 }
4003 }
4004}
4005
4006//----------------------------------------------------------------------------
4007// Search for all visible declarations.
4008//----------------------------------------------------------------------------
4009VisibleDeclConsumer::~VisibleDeclConsumer() { }
4010
4011bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
4012
4013namespace {
4014
4015class ShadowContextRAII;
4016
4017class VisibleDeclsRecord {
4018public:
4019 /// An entry in the shadow map, which is optimized to store a
4020 /// single declaration (the common case) but can also store a list
4021 /// of declarations.
4022 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
4023
4024private:
4025 /// A mapping from declaration names to the declarations that have
4026 /// this name within a particular scope.
4027 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
4028
4029 /// A list of shadow maps, which is used to model name hiding.
4030 std::list<ShadowMap> ShadowMaps;
4031
4032 /// The declaration contexts we have already visited.
4033 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
4034
4035 friend class ShadowContextRAII;
4036
4037public:
4038 /// Determine whether we have already visited this context
4039 /// (and, if not, note that we are going to visit that context now).
4040 bool visitedContext(DeclContext *Ctx) {
4041 return !VisitedContexts.insert(Ptr: Ctx).second;
4042 }
4043
4044 bool alreadyVisitedContext(DeclContext *Ctx) {
4045 return VisitedContexts.count(Ptr: Ctx);
4046 }
4047
4048 /// Determine whether the given declaration is hidden in the
4049 /// current scope.
4050 ///
4051 /// \returns the declaration that hides the given declaration, or
4052 /// NULL if no such declaration exists.
4053 NamedDecl *checkHidden(NamedDecl *ND);
4054
4055 /// Add a declaration to the current shadow map.
4056 void add(NamedDecl *ND) {
4057 ShadowMaps.back()[ND->getDeclName()].push_back(NewVal: ND);
4058 }
4059};
4060
4061/// RAII object that records when we've entered a shadow context.
4062class ShadowContextRAII {
4063 VisibleDeclsRecord &Visible;
4064
4065 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
4066
4067public:
4068 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
4069 Visible.ShadowMaps.emplace_back();
4070 }
4071
4072 ~ShadowContextRAII() {
4073 Visible.ShadowMaps.pop_back();
4074 }
4075};
4076
4077} // end anonymous namespace
4078
4079NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
4080 unsigned IDNS = ND->getIdentifierNamespace();
4081 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
4082 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
4083 SM != SMEnd; ++SM) {
4084 ShadowMap::iterator Pos = SM->find(Val: ND->getDeclName());
4085 if (Pos == SM->end())
4086 continue;
4087
4088 for (auto *D : Pos->second) {
4089 // A tag declaration does not hide a non-tag declaration.
4090 if (D->hasTagIdentifierNamespace() &&
4091 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
4092 Decl::IDNS_ObjCProtocol)))
4093 continue;
4094
4095 // Protocols are in distinct namespaces from everything else.
4096 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
4097 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
4098 D->getIdentifierNamespace() != IDNS)
4099 continue;
4100
4101 // Functions and function templates in the same scope overload
4102 // rather than hide. FIXME: Look for hiding based on function
4103 // signatures!
4104 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
4105 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
4106 SM == ShadowMaps.rbegin())
4107 continue;
4108
4109 // A shadow declaration that's created by a resolved using declaration
4110 // is not hidden by the same using declaration.
4111 if (isa<UsingShadowDecl>(Val: ND) && isa<UsingDecl>(Val: D) &&
4112 cast<UsingShadowDecl>(Val: ND)->getIntroducer() == D)
4113 continue;
4114
4115 // We've found a declaration that hides this one.
4116 return D;
4117 }
4118 }
4119
4120 return nullptr;
4121}
4122
4123namespace {
4124class LookupVisibleHelper {
4125public:
4126 LookupVisibleHelper(VisibleDeclConsumer &Consumer, bool IncludeDependentBases,
4127 bool LoadExternal)
4128 : Consumer(Consumer), IncludeDependentBases(IncludeDependentBases),
4129 LoadExternal(LoadExternal) {}
4130
4131 void lookupVisibleDecls(Sema &SemaRef, Scope *S, Sema::LookupNameKind Kind,
4132 bool IncludeGlobalScope) {
4133 // Determine the set of using directives available during
4134 // unqualified name lookup.
4135 Scope *Initial = S;
4136 UnqualUsingDirectiveSet UDirs(SemaRef);
4137 if (SemaRef.getLangOpts().CPlusPlus) {
4138 // Find the first namespace or translation-unit scope.
4139 while (S && !isNamespaceOrTranslationUnitScope(S))
4140 S = S->getParent();
4141
4142 UDirs.visitScopeChain(S: Initial, InnermostFileScope: S);
4143 }
4144 UDirs.done();
4145
4146 // Look for visible declarations.
4147 LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind);
4148 Result.setAllowHidden(Consumer.includeHiddenDecls());
4149 if (!IncludeGlobalScope)
4150 Visited.visitedContext(Ctx: SemaRef.getASTContext().getTranslationUnitDecl());
4151 ShadowContextRAII Shadow(Visited);
4152 lookupInScope(S: Initial, Result, UDirs);
4153 }
4154
4155 void lookupVisibleDecls(Sema &SemaRef, DeclContext *Ctx,
4156 Sema::LookupNameKind Kind, bool IncludeGlobalScope) {
4157 LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind);
4158 Result.setAllowHidden(Consumer.includeHiddenDecls());
4159 if (!IncludeGlobalScope)
4160 Visited.visitedContext(Ctx: SemaRef.getASTContext().getTranslationUnitDecl());
4161
4162 ShadowContextRAII Shadow(Visited);
4163 lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/true,
4164 /*InBaseClass=*/false);
4165 }
4166
4167private:
4168 void lookupInDeclContext(DeclContext *Ctx, LookupResult &Result,
4169 bool QualifiedNameLookup, bool InBaseClass) {
4170 if (!Ctx)
4171 return;
4172
4173 // Make sure we don't visit the same context twice.
4174 if (Visited.visitedContext(Ctx: Ctx->getPrimaryContext()))
4175 return;
4176
4177 Consumer.EnteredContext(Ctx);
4178
4179 // Outside C++, lookup results for the TU live on identifiers.
4180 if (isa<TranslationUnitDecl>(Val: Ctx) &&
4181 !Result.getSema().getLangOpts().CPlusPlus) {
4182 auto &S = Result.getSema();
4183 auto &Idents = S.Context.Idents;
4184
4185 // Ensure all external identifiers are in the identifier table.
4186 if (LoadExternal)
4187 if (IdentifierInfoLookup *External =
4188 Idents.getExternalIdentifierLookup()) {
4189 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4190 for (StringRef Name = Iter->Next(); !Name.empty();
4191 Name = Iter->Next())
4192 Idents.get(Name);
4193 }
4194
4195 // Walk all lookup results in the TU for each identifier.
4196 for (const auto &Ident : Idents) {
4197 for (auto I = S.IdResolver.begin(Name: Ident.getValue()),
4198 E = S.IdResolver.end();
4199 I != E; ++I) {
4200 if (S.IdResolver.isDeclInScope(D: *I, Ctx)) {
4201 if (NamedDecl *ND = Result.getAcceptableDecl(D: *I)) {
4202 Consumer.FoundDecl(ND, Hiding: Visited.checkHidden(ND), Ctx, InBaseClass);
4203 Visited.add(ND);
4204 }
4205 }
4206 }
4207 }
4208
4209 return;
4210 }
4211
4212 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Val: Ctx))
4213 Result.getSema().ForceDeclarationOfImplicitMembers(Class);
4214
4215 llvm::SmallVector<NamedDecl *, 4> DeclsToVisit;
4216 // We sometimes skip loading namespace-level results (they tend to be huge).
4217 bool Load = LoadExternal ||
4218 !(isa<TranslationUnitDecl>(Val: Ctx) || isa<NamespaceDecl>(Val: Ctx));
4219 // Enumerate all of the results in this context.
4220 for (DeclContextLookupResult R :
4221 Load ? Ctx->lookups()
4222 : Ctx->noload_lookups(/*PreserveInternalState=*/false))
4223 for (auto *D : R)
4224 // Rather than visit immediately, we put ND into a vector and visit
4225 // all decls, in order, outside of this loop. The reason is that
4226 // Consumer.FoundDecl() and LookupResult::getAcceptableDecl(D)
4227 // may invalidate the iterators used in the two
4228 // loops above.
4229 DeclsToVisit.push_back(Elt: D);
4230
4231 for (auto *D : DeclsToVisit)
4232 if (auto *ND = Result.getAcceptableDecl(D)) {
4233 Consumer.FoundDecl(ND, Hiding: Visited.checkHidden(ND), Ctx, InBaseClass);
4234 Visited.add(ND);
4235 }
4236
4237 DeclsToVisit.clear();
4238
4239 // Traverse using directives for qualified name lookup.
4240 if (QualifiedNameLookup) {
4241 ShadowContextRAII Shadow(Visited);
4242 for (auto *I : Ctx->using_directives()) {
4243 if (!Result.getSema().isVisible(D: I))
4244 continue;
4245 lookupInDeclContext(Ctx: I->getNominatedNamespace(), Result,
4246 QualifiedNameLookup, InBaseClass);
4247 }
4248 }
4249
4250 // Traverse the contexts of inherited C++ classes.
4251 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Val: Ctx)) {
4252 if (!Record->hasDefinition())
4253 return;
4254
4255 for (const auto &B : Record->bases()) {
4256 QualType BaseType = B.getType();
4257
4258 RecordDecl *RD;
4259 if (BaseType->isDependentType()) {
4260 if (!IncludeDependentBases) {
4261 // Don't look into dependent bases, because name lookup can't look
4262 // there anyway.
4263 continue;
4264 }
4265 const auto *TST = BaseType->getAs<TemplateSpecializationType>();
4266 if (!TST)
4267 continue;
4268 TemplateName TN = TST->getTemplateName();
4269 const auto *TD =
4270 dyn_cast_or_null<ClassTemplateDecl>(Val: TN.getAsTemplateDecl());
4271 if (!TD)
4272 continue;
4273 RD = TD->getTemplatedDecl();
4274 } else {
4275 RD = BaseType->getAsCXXRecordDecl();
4276 if (!RD)
4277 continue;
4278 }
4279
4280 // FIXME: It would be nice to be able to determine whether referencing
4281 // a particular member would be ambiguous. For example, given
4282 //
4283 // struct A { int member; };
4284 // struct B { int member; };
4285 // struct C : A, B { };
4286 //
4287 // void f(C *c) { c->### }
4288 //
4289 // accessing 'member' would result in an ambiguity. However, we
4290 // could be smart enough to qualify the member with the base
4291 // class, e.g.,
4292 //
4293 // c->B::member
4294 //
4295 // or
4296 //
4297 // c->A::member
4298
4299 // Find results in this base class (and its bases).
4300 ShadowContextRAII Shadow(Visited);
4301 lookupInDeclContext(Ctx: RD, Result, QualifiedNameLookup,
4302 /*InBaseClass=*/true);
4303 }
4304 }
4305
4306 // Traverse the contexts of Objective-C classes.
4307 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Val: Ctx)) {
4308 // Traverse categories.
4309 for (auto *Cat : IFace->visible_categories()) {
4310 ShadowContextRAII Shadow(Visited);
4311 lookupInDeclContext(Ctx: Cat, Result, QualifiedNameLookup,
4312 /*InBaseClass=*/false);
4313 }
4314
4315 // Traverse protocols.
4316 for (auto *I : IFace->all_referenced_protocols()) {
4317 ShadowContextRAII Shadow(Visited);
4318 lookupInDeclContext(Ctx: I, Result, QualifiedNameLookup,
4319 /*InBaseClass=*/false);
4320 }
4321
4322 // Traverse the superclass.
4323 if (IFace->getSuperClass()) {
4324 ShadowContextRAII Shadow(Visited);
4325 lookupInDeclContext(Ctx: IFace->getSuperClass(), Result, QualifiedNameLookup,
4326 /*InBaseClass=*/true);
4327 }
4328
4329 // If there is an implementation, traverse it. We do this to find
4330 // synthesized ivars.
4331 if (IFace->getImplementation()) {
4332 ShadowContextRAII Shadow(Visited);
4333 lookupInDeclContext(Ctx: IFace->getImplementation(), Result,
4334 QualifiedNameLookup, InBaseClass);
4335 }
4336 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Val: Ctx)) {
4337 for (auto *I : Protocol->protocols()) {
4338 ShadowContextRAII Shadow(Visited);
4339 lookupInDeclContext(Ctx: I, Result, QualifiedNameLookup,
4340 /*InBaseClass=*/false);
4341 }
4342 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Val: Ctx)) {
4343 for (auto *I : Category->protocols()) {
4344 ShadowContextRAII Shadow(Visited);
4345 lookupInDeclContext(Ctx: I, Result, QualifiedNameLookup,
4346 /*InBaseClass=*/false);
4347 }
4348
4349 // If there is an implementation, traverse it.
4350 if (Category->getImplementation()) {
4351 ShadowContextRAII Shadow(Visited);
4352 lookupInDeclContext(Ctx: Category->getImplementation(), Result,
4353 QualifiedNameLookup, /*InBaseClass=*/true);
4354 }
4355 }
4356 }
4357
4358 void lookupInScope(Scope *S, LookupResult &Result,
4359 UnqualUsingDirectiveSet &UDirs) {
4360 // No clients run in this mode and it's not supported. Please add tests and
4361 // remove the assertion if you start relying on it.
4362 assert(!IncludeDependentBases && "Unsupported flag for lookupInScope");
4363
4364 if (!S)
4365 return;
4366
4367 if (!S->getEntity() ||
4368 (!S->getParent() && !Visited.alreadyVisitedContext(Ctx: S->getEntity())) ||
4369 (S->getEntity())->isFunctionOrMethod()) {
4370 FindLocalExternScope FindLocals(Result);
4371 // Walk through the declarations in this Scope. The consumer might add new
4372 // decls to the scope as part of deserialization, so make a copy first.
4373 SmallVector<Decl *, 8> ScopeDecls(S->decls().begin(), S->decls().end());
4374 for (Decl *D : ScopeDecls) {
4375 if (NamedDecl *ND = dyn_cast<NamedDecl>(Val: D))
4376 if ((ND = Result.getAcceptableDecl(D: ND))) {
4377 Consumer.FoundDecl(ND, Hiding: Visited.checkHidden(ND), Ctx: nullptr, InBaseClass: false);
4378 Visited.add(ND);
4379 }
4380 }
4381 }
4382
4383 DeclContext *Entity = S->getLookupEntity();
4384 if (Entity) {
4385 // Look into this scope's declaration context, along with any of its
4386 // parent lookup contexts (e.g., enclosing classes), up to the point
4387 // where we hit the context stored in the next outer scope.
4388 DeclContext *OuterCtx = findOuterContext(S);
4389
4390 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(DC: OuterCtx);
4391 Ctx = Ctx->getLookupParent()) {
4392 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Val: Ctx)) {
4393 if (Method->isInstanceMethod()) {
4394 // For instance methods, look for ivars in the method's interface.
4395 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
4396 Result.getNameLoc(),
4397 Sema::LookupMemberName);
4398 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
4399 lookupInDeclContext(Ctx: IFace, Result&: IvarResult,
4400 /*QualifiedNameLookup=*/false,
4401 /*InBaseClass=*/false);
4402 }
4403 }
4404
4405 // We've already performed all of the name lookup that we need
4406 // to for Objective-C methods; the next context will be the
4407 // outer scope.
4408 break;
4409 }
4410
4411 if (Ctx->isFunctionOrMethod())
4412 continue;
4413
4414 lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/false,
4415 /*InBaseClass=*/false);
4416 }
4417 } else if (!S->getParent()) {
4418 // Look into the translation unit scope. We walk through the translation
4419 // unit's declaration context, because the Scope itself won't have all of
4420 // the declarations if we loaded a precompiled header.
4421 // FIXME: We would like the translation unit's Scope object to point to
4422 // the translation unit, so we don't need this special "if" branch.
4423 // However, doing so would force the normal C++ name-lookup code to look
4424 // into the translation unit decl when the IdentifierInfo chains would
4425 // suffice. Once we fix that problem (which is part of a more general
4426 // "don't look in DeclContexts unless we have to" optimization), we can
4427 // eliminate this.
4428 Entity = Result.getSema().Context.getTranslationUnitDecl();
4429 lookupInDeclContext(Ctx: Entity, Result, /*QualifiedNameLookup=*/false,
4430 /*InBaseClass=*/false);
4431 }
4432
4433 if (Entity) {
4434 // Lookup visible declarations in any namespaces found by using
4435 // directives.
4436 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(DC: Entity))
4437 lookupInDeclContext(
4438 Ctx: const_cast<DeclContext *>(UUE.getNominatedNamespace()), Result,
4439 /*QualifiedNameLookup=*/false,
4440 /*InBaseClass=*/false);
4441 }
4442
4443 // Lookup names in the parent scope.
4444 ShadowContextRAII Shadow(Visited);
4445 lookupInScope(S: S->getParent(), Result, UDirs);
4446 }
4447
4448private:
4449 VisibleDeclsRecord Visited;
4450 VisibleDeclConsumer &Consumer;
4451 bool IncludeDependentBases;
4452 bool LoadExternal;
4453};
4454} // namespace
4455
4456void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
4457 VisibleDeclConsumer &Consumer,
4458 bool IncludeGlobalScope, bool LoadExternal) {
4459 LookupVisibleHelper H(Consumer, /*IncludeDependentBases=*/false,
4460 LoadExternal);
4461 H.lookupVisibleDecls(SemaRef&: *this, S, Kind, IncludeGlobalScope);
4462}
4463
4464void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
4465 VisibleDeclConsumer &Consumer,
4466 bool IncludeGlobalScope,
4467 bool IncludeDependentBases, bool LoadExternal) {
4468 LookupVisibleHelper H(Consumer, IncludeDependentBases, LoadExternal);
4469 H.lookupVisibleDecls(SemaRef&: *this, Ctx, Kind, IncludeGlobalScope);
4470}
4471
4472LabelDecl *Sema::LookupExistingLabel(IdentifierInfo *II, SourceLocation Loc) {
4473 NamedDecl *Res = LookupSingleName(S: CurScope, Name: II, Loc, NameKind: LookupLabel,
4474 Redecl: RedeclarationKind::NotForRedeclaration);
4475 // If we found a label, check to see if it is in the same context as us.
4476 // When in a Block, we don't want to reuse a label in an enclosing function.
4477 if (!Res ||
4478 Res->getDeclContext()->getEnclosingNonExpansionStatementContext() !=
4479 CurContext->getEnclosingNonExpansionStatementContext())
4480 return nullptr;
4481 return cast<LabelDecl>(Val: Res);
4482}
4483
4484LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc,
4485 SourceLocation GnuLabelLoc,
4486 bool IsLabelStmt) {
4487 if (GnuLabelLoc.isValid()) {
4488 // Local label definitions always shadow existing labels.
4489 auto *Res = LabelDecl::Create(C&: Context, DC: CurContext, IdentL: Loc, II, GnuLabelL: GnuLabelLoc);
4490 Scope *S = CurScope;
4491 PushOnScopeChains(D: Res, S, AddToContext: true);
4492 return cast<LabelDecl>(Val: Res);
4493 }
4494
4495 LabelDecl *Existing = LookupExistingLabel(II, Loc);
4496
4497 // C++26 [stmt.label]p4 An identifier label shall not be enclosed by an
4498 // expansion-statement.
4499 //
4500 // As an extension, we allow GNU local labels since they are logically
4501 // scoped to the containing block, which prevents us from ending up with
4502 // multiple copies of the same label in a function after instantiation.
4503 //
4504 // While allowing this is slightly more complicated, it also has the nice
4505 // side-effect of avoiding otherwise rather horrible diagnostics you'd get
4506 // when trying to use '__label__' if we didn't support this.
4507 if (IsLabelStmt && CurContext->isExpansionStmt()) {
4508 if (Existing && Existing->isGnuLocal())
4509 return Existing;
4510
4511 // Drop the label from the AST as creating it anyway would cause us to
4512 // either issue various unhelpful diagnostics (if we were to declare
4513 // it in the function decl context) or shadow a valid label with the
4514 // same name outside the expansion statement.
4515 Diag(Loc, DiagID: diag::err_expansion_stmt_label);
4516 return nullptr;
4517 }
4518
4519 if (Existing)
4520 return Existing;
4521
4522 // Declare non-local labels outside any expansion statements; this is required
4523 // to support jumping out of an expansion statement.
4524 ContextRAII Ctx{*this, CurContext->getEnclosingNonExpansionStatementContext(),
4525 /*NewThisContext=*/false};
4526
4527 // Not a GNU local label. Create the backing decl.
4528 auto *Res = LabelDecl::Create(C&: Context, DC: CurContext, IdentL: Loc, II);
4529 Scope *S = CurScope->getFnParent();
4530 assert(S && "Not in a function?");
4531 PushOnScopeChains(D: Res, S, AddToContext: true);
4532 return Res;
4533}
4534
4535//===----------------------------------------------------------------------===//
4536// Typo correction
4537//===----------------------------------------------------------------------===//
4538
4539static bool isCandidateViable(CorrectionCandidateCallback &CCC,
4540 TypoCorrection &Candidate) {
4541 Candidate.setCallbackDistance(CCC.RankCandidate(candidate: Candidate));
4542 return Candidate.getEditDistance(Normalized: false) != TypoCorrection::InvalidDistance;
4543}
4544
4545static void LookupPotentialTypoResult(Sema &SemaRef,
4546 LookupResult &Res,
4547 IdentifierInfo *Name,
4548 Scope *S, CXXScopeSpec *SS,
4549 DeclContext *MemberContext,
4550 bool EnteringContext,
4551 bool isObjCIvarLookup,
4552 bool FindHidden);
4553
4554/// Check whether the declarations found for a typo correction are
4555/// visible. Set the correction's RequiresImport flag to true if none of the
4556/// declarations are visible, false otherwise.
4557static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
4558 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
4559
4560 for (/**/; DI != DE; ++DI)
4561 if (!LookupResult::isVisible(SemaRef, D: *DI))
4562 break;
4563 // No filtering needed if all decls are visible.
4564 if (DI == DE) {
4565 TC.setRequiresImport(false);
4566 return;
4567 }
4568
4569 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
4570 bool AnyVisibleDecls = !NewDecls.empty();
4571
4572 for (/**/; DI != DE; ++DI) {
4573 if (LookupResult::isVisible(SemaRef, D: *DI)) {
4574 if (!AnyVisibleDecls) {
4575 // Found a visible decl, discard all hidden ones.
4576 AnyVisibleDecls = true;
4577 NewDecls.clear();
4578 }
4579 NewDecls.push_back(Elt: *DI);
4580 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
4581 NewDecls.push_back(Elt: *DI);
4582 }
4583
4584 if (NewDecls.empty())
4585 TC = TypoCorrection();
4586 else {
4587 TC.setCorrectionDecls(NewDecls);
4588 TC.setRequiresImport(!AnyVisibleDecls);
4589 }
4590}
4591
4592// Fill the supplied vector with the IdentifierInfo pointers for each piece of
4593// the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
4594// fill the vector with the IdentifierInfo pointers for "foo" and "bar").
4595static void getNestedNameSpecifierIdentifiers(
4596 NestedNameSpecifier NNS,
4597 SmallVectorImpl<const IdentifierInfo *> &Identifiers) {
4598 switch (NNS.getKind()) {
4599 case NestedNameSpecifier::Kind::Null:
4600 Identifiers.clear();
4601 return;
4602
4603 case NestedNameSpecifier::Kind::Namespace: {
4604 auto [Namespace, Prefix] = NNS.getAsNamespaceAndPrefix();
4605 getNestedNameSpecifierIdentifiers(NNS: Prefix, Identifiers);
4606 if (const auto *NS = dyn_cast<NamespaceDecl>(Val: Namespace);
4607 NS && NS->isAnonymousNamespace())
4608 return;
4609 Identifiers.push_back(Elt: Namespace->getIdentifier());
4610 return;
4611 }
4612
4613 case NestedNameSpecifier::Kind::Type: {
4614 for (const Type *T = NNS.getAsType(); /**/; /**/) {
4615 switch (T->getTypeClass()) {
4616 case Type::DependentName: {
4617 auto *DT = cast<DependentNameType>(Val: T);
4618 getNestedNameSpecifierIdentifiers(NNS: DT->getQualifier(), Identifiers);
4619 Identifiers.push_back(Elt: DT->getIdentifier());
4620 return;
4621 }
4622 case Type::TemplateSpecialization: {
4623 TemplateName Name =
4624 cast<TemplateSpecializationType>(Val: T)->getTemplateName();
4625 if (const DependentTemplateName *DTN =
4626 Name.getAsDependentTemplateName()) {
4627 getNestedNameSpecifierIdentifiers(NNS: DTN->getQualifier(), Identifiers);
4628 if (const auto *II = DTN->getName().getIdentifier())
4629 Identifiers.push_back(Elt: II);
4630 return;
4631 }
4632 if (const QualifiedTemplateName *QTN =
4633 Name.getAsQualifiedTemplateName()) {
4634 getNestedNameSpecifierIdentifiers(NNS: QTN->getQualifier(), Identifiers);
4635 Name = QTN->getUnderlyingTemplate();
4636 }
4637 if (const auto *TD = Name.getAsTemplateDecl(/*IgnoreDeduced=*/true))
4638 Identifiers.push_back(Elt: TD->getIdentifier());
4639 return;
4640 }
4641 case Type::SubstTemplateTypeParm:
4642 T = cast<SubstTemplateTypeParmType>(Val: T)
4643 ->getReplacementType()
4644 .getTypePtr();
4645 continue;
4646 case Type::TemplateTypeParm:
4647 Identifiers.push_back(Elt: cast<TemplateTypeParmType>(Val: T)->getIdentifier());
4648 return;
4649 case Type::Decltype:
4650 return;
4651 case Type::Enum:
4652 case Type::Record:
4653 case Type::InjectedClassName: {
4654 auto *TT = cast<TagType>(Val: T);
4655 getNestedNameSpecifierIdentifiers(NNS: TT->getQualifier(), Identifiers);
4656 Identifiers.push_back(Elt: TT->getDecl()->getIdentifier());
4657 return;
4658 }
4659 case Type::Typedef: {
4660 auto *TT = cast<TypedefType>(Val: T);
4661 getNestedNameSpecifierIdentifiers(NNS: TT->getQualifier(), Identifiers);
4662 Identifiers.push_back(Elt: TT->getDecl()->getIdentifier());
4663 return;
4664 }
4665 case Type::Using: {
4666 auto *TT = cast<UsingType>(Val: T);
4667 getNestedNameSpecifierIdentifiers(NNS: TT->getQualifier(), Identifiers);
4668 Identifiers.push_back(Elt: TT->getDecl()->getIdentifier());
4669 return;
4670 }
4671 case Type::UnresolvedUsing: {
4672 auto *TT = cast<UnresolvedUsingType>(Val: T);
4673 getNestedNameSpecifierIdentifiers(NNS: TT->getQualifier(), Identifiers);
4674 Identifiers.push_back(Elt: TT->getDecl()->getIdentifier());
4675 return;
4676 }
4677 default:
4678 Identifiers.push_back(Elt: QualType(T, 0).getBaseTypeIdentifier());
4679 return;
4680 }
4681 }
4682 break;
4683 }
4684
4685 case NestedNameSpecifier::Kind::Global:
4686 case NestedNameSpecifier::Kind::MicrosoftSuper:
4687 return;
4688 }
4689}
4690
4691void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
4692 DeclContext *Ctx, bool InBaseClass) {
4693 // Don't consider hidden names for typo correction.
4694 if (Hiding)
4695 return;
4696
4697 // Only consider entities with identifiers for names, ignoring
4698 // special names (constructors, overloaded operators, selectors,
4699 // etc.).
4700 IdentifierInfo *Name = ND->getIdentifier();
4701 if (!Name)
4702 return;
4703
4704 // Only consider visible declarations and declarations from modules with
4705 // names that exactly match.
4706 if (!LookupResult::isVisible(SemaRef, D: ND) && Name != Typo)
4707 return;
4708
4709 FoundName(Name: Name->getName());
4710}
4711
4712void TypoCorrectionConsumer::FoundName(StringRef Name) {
4713 // Compute the edit distance between the typo and the name of this
4714 // entity, and add the identifier to the list of results.
4715 addName(Name, ND: nullptr);
4716}
4717
4718void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) {
4719 // Compute the edit distance between the typo and this keyword,
4720 // and add the keyword to the list of results.
4721 addName(Name: Keyword, /*ND=*/nullptr, /*NNS=*/std::nullopt, /*isKeyword=*/true);
4722}
4723
4724void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
4725 NestedNameSpecifier NNS, bool isKeyword) {
4726 // Use a simple length-based heuristic to determine the minimum possible
4727 // edit distance. If the minimum isn't good enough, bail out early.
4728 StringRef TypoStr = Typo->getName();
4729 unsigned MinED = abs(x: (int)Name.size() - (int)TypoStr.size());
4730 if (MinED && TypoStr.size() / MinED < 3)
4731 return;
4732
4733 // Compute an upper bound on the allowable edit distance, so that the
4734 // edit-distance algorithm can short-circuit.
4735 unsigned UpperBound = (TypoStr.size() + 2) / 3;
4736 unsigned ED = TypoStr.edit_distance(Other: Name, AllowReplacements: true, MaxEditDistance: UpperBound);
4737 if (ED > UpperBound) return;
4738
4739 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
4740 if (isKeyword) TC.makeKeyword();
4741 TC.setCorrectionRange(SS: nullptr, TypoName: Result.getLookupNameInfo());
4742 addCorrection(Correction: TC);
4743}
4744
4745static const unsigned MaxTypoDistanceResultSets = 5;
4746
4747void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) {
4748 StringRef TypoStr = Typo->getName();
4749 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
4750
4751 // For very short typos, ignore potential corrections that have a different
4752 // base identifier from the typo or which have a normalized edit distance
4753 // longer than the typo itself.
4754 if (TypoStr.size() < 3 &&
4755 (Name != TypoStr || Correction.getEditDistance(Normalized: true) > TypoStr.size()))
4756 return;
4757
4758 // If the correction is resolved but is not viable, ignore it.
4759 if (Correction.isResolved()) {
4760 checkCorrectionVisibility(SemaRef, TC&: Correction);
4761 if (!Correction || !isCandidateViable(CCC&: *CorrectionValidator, Candidate&: Correction))
4762 return;
4763 }
4764
4765 TypoResultList &CList =
4766 CorrectionResults[Correction.getEditDistance(Normalized: false)][Name];
4767
4768 if (!CList.empty() && !CList.back().isResolved())
4769 CList.pop_back();
4770 if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
4771 auto RI = llvm::find_if(Range&: CList, P: [NewND](const TypoCorrection &TypoCorr) {
4772 return TypoCorr.getCorrectionDecl() == NewND;
4773 });
4774 if (RI != CList.end()) {
4775 // The Correction refers to a decl already in the list. No insertion is
4776 // necessary and all further cases will return.
4777
4778 auto IsDeprecated = [](Decl *D) {
4779 while (D) {
4780 if (D->isDeprecated())
4781 return true;
4782 D = llvm::dyn_cast_or_null<NamespaceDecl>(Val: D->getDeclContext());
4783 }
4784 return false;
4785 };
4786
4787 // Prefer non deprecated Corrections over deprecated and only then
4788 // sort using an alphabetical order.
4789 std::pair<bool, std::string> NewKey = {
4790 IsDeprecated(Correction.getFoundDecl()),
4791 Correction.getAsString(LO: SemaRef.getLangOpts())};
4792
4793 std::pair<bool, std::string> PrevKey = {
4794 IsDeprecated(RI->getFoundDecl()),
4795 RI->getAsString(LO: SemaRef.getLangOpts())};
4796
4797 if (NewKey < PrevKey)
4798 *RI = std::move(Correction);
4799 return;
4800 }
4801 }
4802 if (CList.empty() || Correction.isResolved())
4803 CList.push_back(Elt: Correction);
4804
4805 while (CorrectionResults.size() > MaxTypoDistanceResultSets)
4806 CorrectionResults.erase(position: std::prev(x: CorrectionResults.end()));
4807}
4808
4809void TypoCorrectionConsumer::addNamespaces(
4810 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
4811 SearchNamespaces = true;
4812
4813 for (auto KNPair : KnownNamespaces)
4814 Namespaces.addNameSpecifier(Ctx: KNPair.first);
4815
4816 bool SSIsTemplate = false;
4817 if (NestedNameSpecifier NNS = (SS ? SS->getScopeRep() : std::nullopt)) {
4818 if (NNS.getKind() == NestedNameSpecifier::Kind::Type)
4819 SSIsTemplate =
4820 NNS.getAsType()->getTypeClass() == Type::TemplateSpecialization;
4821 }
4822 // Do not transform this into an iterator-based loop. The loop body can
4823 // trigger the creation of further types (through lazy deserialization) and
4824 // invalid iterators into this list.
4825 auto &Types = SemaRef.getASTContext().getTypes();
4826 for (unsigned I = 0; I != Types.size(); ++I) {
4827 const auto *TI = Types[I];
4828 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
4829 CD = CD->getCanonicalDecl();
4830 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
4831 !CD->isUnion() && CD->getIdentifier() &&
4832 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(Val: CD)) &&
4833 (CD->isBeingDefined() || CD->isCompleteDefinition()))
4834 Namespaces.addNameSpecifier(Ctx: CD);
4835 }
4836 }
4837}
4838
4839const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() {
4840 if (++CurrentTCIndex < ValidatedCorrections.size())
4841 return ValidatedCorrections[CurrentTCIndex];
4842
4843 CurrentTCIndex = ValidatedCorrections.size();
4844 while (!CorrectionResults.empty()) {
4845 auto DI = CorrectionResults.begin();
4846 if (DI->second.empty()) {
4847 CorrectionResults.erase(position: DI);
4848 continue;
4849 }
4850
4851 auto RI = DI->second.begin();
4852 if (RI->second.empty()) {
4853 DI->second.erase(I: RI);
4854 performQualifiedLookups();
4855 continue;
4856 }
4857
4858 TypoCorrection TC = RI->second.pop_back_val();
4859 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(Candidate&: TC)) {
4860 ValidatedCorrections.push_back(Elt: TC);
4861 return ValidatedCorrections[CurrentTCIndex];
4862 }
4863 }
4864 return ValidatedCorrections[0]; // The empty correction.
4865}
4866
4867bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
4868 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
4869 DeclContext *TempMemberContext = MemberContext;
4870 CXXScopeSpec *TempSS = SS.get();
4871retry_lookup:
4872 LookupPotentialTypoResult(SemaRef, Res&: Result, Name, S, SS: TempSS, MemberContext: TempMemberContext,
4873 EnteringContext,
4874 isObjCIvarLookup: CorrectionValidator->IsObjCIvarLookup,
4875 FindHidden: Name == Typo && !Candidate.WillReplaceSpecifier());
4876 switch (Result.getResultKind()) {
4877 case LookupResultKind::NotFound:
4878 case LookupResultKind::NotFoundInCurrentInstantiation:
4879 case LookupResultKind::FoundUnresolvedValue:
4880 if (TempSS) {
4881 // Immediately retry the lookup without the given CXXScopeSpec
4882 TempSS = nullptr;
4883 Candidate.WillReplaceSpecifier(ForceReplacement: true);
4884 goto retry_lookup;
4885 }
4886 if (TempMemberContext) {
4887 if (SS && !TempSS)
4888 TempSS = SS.get();
4889 TempMemberContext = nullptr;
4890 goto retry_lookup;
4891 }
4892 if (SearchNamespaces)
4893 QualifiedResults.push_back(Elt: Candidate);
4894 break;
4895
4896 case LookupResultKind::Ambiguous:
4897 // We don't deal with ambiguities.
4898 break;
4899
4900 case LookupResultKind::Found:
4901 case LookupResultKind::FoundOverloaded:
4902 // Store all of the Decls for overloaded symbols
4903 for (auto *TRD : Result)
4904 Candidate.addCorrectionDecl(CDecl: TRD);
4905 checkCorrectionVisibility(SemaRef, TC&: Candidate);
4906 if (!isCandidateViable(CCC&: *CorrectionValidator, Candidate)) {
4907 if (SearchNamespaces)
4908 QualifiedResults.push_back(Elt: Candidate);
4909 break;
4910 }
4911 Candidate.setCorrectionRange(SS: SS.get(), TypoName: Result.getLookupNameInfo());
4912 return true;
4913 }
4914 return false;
4915}
4916
4917void TypoCorrectionConsumer::performQualifiedLookups() {
4918 unsigned TypoLen = Typo->getName().size();
4919 for (const TypoCorrection &QR : QualifiedResults) {
4920 for (const auto &NSI : Namespaces) {
4921 DeclContext *Ctx = NSI.DeclCtx;
4922 CXXRecordDecl *NamingClass = NSI.NameSpecifier.getAsRecordDecl();
4923
4924 // If the current NestedNameSpecifier refers to a class and the
4925 // current correction candidate is the name of that class, then skip
4926 // it as it is unlikely a qualified version of the class' constructor
4927 // is an appropriate correction.
4928 if (NamingClass &&
4929 NamingClass->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
4930 continue;
4931
4932 TypoCorrection TC(QR);
4933 TC.ClearCorrectionDecls();
4934 TC.setCorrectionSpecifier(NSI.NameSpecifier);
4935 TC.setQualifierDistance(NSI.EditDistance);
4936 TC.setCallbackDistance(0); // Reset the callback distance
4937
4938 // If the current correction candidate and namespace combination are
4939 // too far away from the original typo based on the normalized edit
4940 // distance, then skip performing a qualified name lookup.
4941 unsigned TmpED = TC.getEditDistance(Normalized: true);
4942 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4943 TypoLen / TmpED < 3)
4944 continue;
4945
4946 Result.clear();
4947 Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4948 if (!SemaRef.LookupQualifiedName(R&: Result, LookupCtx: Ctx))
4949 continue;
4950
4951 // Any corrections added below will be validated in subsequent
4952 // iterations of the main while() loop over the Consumer's contents.
4953 switch (Result.getResultKind()) {
4954 case LookupResultKind::Found:
4955 case LookupResultKind::FoundOverloaded: {
4956 if (SS && SS->isValid()) {
4957 std::string NewQualified = TC.getAsString(LO: SemaRef.getLangOpts());
4958 std::string OldQualified;
4959 llvm::raw_string_ostream OldOStream(OldQualified);
4960 SS->getScopeRep().print(OS&: OldOStream, Policy: SemaRef.getPrintingPolicy());
4961 OldOStream << Typo->getName();
4962 // If correction candidate would be an identical written qualified
4963 // identifier, then the existing CXXScopeSpec probably included a
4964 // typedef that didn't get accounted for properly.
4965 if (OldOStream.str() == NewQualified)
4966 break;
4967 }
4968 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4969 TRD != TRDEnd; ++TRD) {
4970 if (SemaRef.CheckMemberAccess(UseLoc: TC.getCorrectionRange().getBegin(),
4971 NamingClass,
4972 Found: TRD.getPair()) == Sema::AR_accessible)
4973 TC.addCorrectionDecl(CDecl: *TRD);
4974 }
4975 if (TC.isResolved()) {
4976 TC.setCorrectionRange(SS: SS.get(), TypoName: Result.getLookupNameInfo());
4977 addCorrection(Correction: TC);
4978 }
4979 break;
4980 }
4981 case LookupResultKind::NotFound:
4982 case LookupResultKind::NotFoundInCurrentInstantiation:
4983 case LookupResultKind::Ambiguous:
4984 case LookupResultKind::FoundUnresolvedValue:
4985 break;
4986 }
4987 }
4988 }
4989 QualifiedResults.clear();
4990}
4991
4992TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4993 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4994 : Context(Context), CurContextChain(buildContextChain(Start: CurContext)) {
4995 if (NestedNameSpecifier NNS =
4996 CurScopeSpec ? CurScopeSpec->getScopeRep() : std::nullopt) {
4997 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4998 NNS.print(OS&: SpecifierOStream, Policy: Context.getPrintingPolicy());
4999
5000 getNestedNameSpecifierIdentifiers(NNS, Identifiers&: CurNameSpecifierIdentifiers);
5001 }
5002 // Build the list of identifiers that would be used for an absolute
5003 // (from the global context) NestedNameSpecifier referring to the current
5004 // context.
5005 for (DeclContext *C : llvm::reverse(C&: CurContextChain)) {
5006 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(Val: C))
5007 CurContextIdentifiers.push_back(Elt: ND->getIdentifier());
5008 }
5009
5010 // Add the global context as a NestedNameSpecifier
5011 SpecifierInfo SI = {.DeclCtx: cast<DeclContext>(Val: Context.getTranslationUnitDecl()),
5012 .NameSpecifier: NestedNameSpecifier::getGlobal(), .EditDistance: 1};
5013 DistanceMap[1].push_back(Elt: SI);
5014}
5015
5016auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
5017 DeclContext *Start) -> DeclContextList {
5018 assert(Start && "Building a context chain from a null context");
5019 DeclContextList Chain;
5020 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
5021 DC = DC->getLookupParent()) {
5022 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(Val: DC);
5023 if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
5024 !(ND && ND->isAnonymousNamespace()))
5025 Chain.push_back(Elt: DC->getPrimaryContext());
5026 }
5027 return Chain;
5028}
5029
5030unsigned
5031TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
5032 DeclContextList &DeclChain, NestedNameSpecifier &NNS) {
5033 unsigned NumSpecifiers = 0;
5034 for (DeclContext *C : llvm::reverse(C&: DeclChain)) {
5035 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(Val: C)) {
5036 NNS = NestedNameSpecifier(Context, ND, NNS);
5037 ++NumSpecifiers;
5038 } else if (auto *RD = dyn_cast_or_null<RecordDecl>(Val: C)) {
5039 QualType T = Context.getTagType(Keyword: ElaboratedTypeKeyword::None, Qualifier: NNS, TD: RD,
5040 /*OwnsTag=*/false);
5041 NNS = NestedNameSpecifier(T.getTypePtr());
5042 ++NumSpecifiers;
5043 }
5044 }
5045 return NumSpecifiers;
5046}
5047
5048void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
5049 DeclContext *Ctx) {
5050 NestedNameSpecifier NNS = std::nullopt;
5051 unsigned NumSpecifiers = 0;
5052 DeclContextList NamespaceDeclChain(buildContextChain(Start: Ctx));
5053 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
5054
5055 // Eliminate common elements from the two DeclContext chains.
5056 for (DeclContext *C : llvm::reverse(C&: CurContextChain)) {
5057 if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C)
5058 break;
5059 NamespaceDeclChain.pop_back();
5060 }
5061
5062 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
5063 NumSpecifiers = buildNestedNameSpecifier(DeclChain&: NamespaceDeclChain, NNS);
5064
5065 // Add an explicit leading '::' specifier if needed.
5066 if (NamespaceDeclChain.empty()) {
5067 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
5068 NNS = NestedNameSpecifier::getGlobal();
5069 NumSpecifiers =
5070 buildNestedNameSpecifier(DeclChain&: FullNamespaceDeclChain, NNS);
5071 } else if (NamedDecl *ND =
5072 dyn_cast_or_null<NamedDecl>(Val: NamespaceDeclChain.back())) {
5073 IdentifierInfo *Name = ND->getIdentifier();
5074 bool SameNameSpecifier = false;
5075 if (llvm::is_contained(Range&: CurNameSpecifierIdentifiers, Element: Name)) {
5076 std::string NewNameSpecifier;
5077 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
5078 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
5079 getNestedNameSpecifierIdentifiers(NNS, Identifiers&: NewNameSpecifierIdentifiers);
5080 NNS.print(OS&: SpecifierOStream, Policy: Context.getPrintingPolicy());
5081 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
5082 }
5083 if (SameNameSpecifier || llvm::is_contained(Range&: CurContextIdentifiers, Element: Name)) {
5084 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
5085 NNS = NestedNameSpecifier::getGlobal();
5086 NumSpecifiers =
5087 buildNestedNameSpecifier(DeclChain&: FullNamespaceDeclChain, NNS);
5088 }
5089 }
5090
5091 // If the built NestedNameSpecifier would be replacing an existing
5092 // NestedNameSpecifier, use the number of component identifiers that
5093 // would need to be changed as the edit distance instead of the number
5094 // of components in the built NestedNameSpecifier.
5095 if (NNS && !CurNameSpecifierIdentifiers.empty()) {
5096 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
5097 getNestedNameSpecifierIdentifiers(NNS, Identifiers&: NewNameSpecifierIdentifiers);
5098 NumSpecifiers =
5099 llvm::ComputeEditDistance(FromArray: llvm::ArrayRef(CurNameSpecifierIdentifiers),
5100 ToArray: llvm::ArrayRef(NewNameSpecifierIdentifiers));
5101 }
5102
5103 SpecifierInfo SI = {.DeclCtx: Ctx, .NameSpecifier: NNS, .EditDistance: NumSpecifiers};
5104 DistanceMap[NumSpecifiers].push_back(Elt: SI);
5105}
5106
5107/// Perform name lookup for a possible result for typo correction.
5108static void LookupPotentialTypoResult(Sema &SemaRef,
5109 LookupResult &Res,
5110 IdentifierInfo *Name,
5111 Scope *S, CXXScopeSpec *SS,
5112 DeclContext *MemberContext,
5113 bool EnteringContext,
5114 bool isObjCIvarLookup,
5115 bool FindHidden) {
5116 Res.suppressDiagnostics();
5117 Res.clear();
5118 Res.setLookupName(Name);
5119 Res.setAllowHidden(FindHidden);
5120 if (MemberContext) {
5121 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(Val: MemberContext)) {
5122 if (isObjCIvarLookup) {
5123 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(IVarName: Name)) {
5124 Res.addDecl(D: Ivar);
5125 Res.resolveKind();
5126 return;
5127 }
5128 }
5129
5130 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(
5131 PropertyId: Name, QueryKind: ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
5132 Res.addDecl(D: Prop);
5133 Res.resolveKind();
5134 return;
5135 }
5136 }
5137
5138 SemaRef.LookupQualifiedName(R&: Res, LookupCtx: MemberContext);
5139 return;
5140 }
5141
5142 SemaRef.LookupParsedName(R&: Res, S, SS,
5143 /*ObjectType=*/QualType(),
5144 /*AllowBuiltinCreation=*/false, EnteringContext);
5145
5146 // Fake ivar lookup; this should really be part of
5147 // LookupParsedName.
5148 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
5149 if (Method->isInstanceMethod() && Method->getClassInterface() &&
5150 (Res.empty() ||
5151 (Res.isSingleResult() &&
5152 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) {
5153 if (ObjCIvarDecl *IV
5154 = Method->getClassInterface()->lookupInstanceVariable(IVarName: Name)) {
5155 Res.addDecl(D: IV);
5156 Res.resolveKind();
5157 }
5158 }
5159 }
5160}
5161
5162/// Add keywords to the consumer as possible typo corrections.
5163static void AddKeywordsToConsumer(Sema &SemaRef,
5164 TypoCorrectionConsumer &Consumer,
5165 Scope *S, CorrectionCandidateCallback &CCC,
5166 bool AfterNestedNameSpecifier) {
5167 if (AfterNestedNameSpecifier) {
5168 // For 'X::', we know exactly which keywords can appear next.
5169 Consumer.addKeywordResult(Keyword: "template");
5170 if (CCC.WantExpressionKeywords)
5171 Consumer.addKeywordResult(Keyword: "operator");
5172 return;
5173 }
5174
5175 if (CCC.WantObjCSuper)
5176 Consumer.addKeywordResult(Keyword: "super");
5177
5178 if (CCC.WantTypeSpecifiers) {
5179 // Add type-specifier keywords to the set of results.
5180 static const char *const CTypeSpecs[] = {
5181 "char", "const", "double", "enum", "float", "int", "long", "short",
5182 "signed", "struct", "union", "unsigned", "void", "volatile",
5183 "_Complex",
5184 // storage-specifiers as well
5185 "extern", "inline", "static", "typedef"
5186 };
5187
5188 for (const auto *CTS : CTypeSpecs)
5189 Consumer.addKeywordResult(Keyword: CTS);
5190
5191 if (SemaRef.getLangOpts().C99 && !SemaRef.getLangOpts().C2y)
5192 Consumer.addKeywordResult(Keyword: "_Imaginary");
5193
5194 if (SemaRef.getLangOpts().C99)
5195 Consumer.addKeywordResult(Keyword: "restrict");
5196 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
5197 Consumer.addKeywordResult(Keyword: "bool");
5198 else if (SemaRef.getLangOpts().C99)
5199 Consumer.addKeywordResult(Keyword: "_Bool");
5200
5201 if (SemaRef.getLangOpts().CPlusPlus) {
5202 Consumer.addKeywordResult(Keyword: "class");
5203 Consumer.addKeywordResult(Keyword: "typename");
5204 Consumer.addKeywordResult(Keyword: "wchar_t");
5205
5206 if (SemaRef.getLangOpts().CPlusPlus11) {
5207 Consumer.addKeywordResult(Keyword: "char16_t");
5208 Consumer.addKeywordResult(Keyword: "char32_t");
5209 Consumer.addKeywordResult(Keyword: "constexpr");
5210 Consumer.addKeywordResult(Keyword: "decltype");
5211 Consumer.addKeywordResult(Keyword: "thread_local");
5212 }
5213 }
5214
5215 if (SemaRef.getLangOpts().GNUKeywords)
5216 Consumer.addKeywordResult(Keyword: "typeof");
5217 } else if (CCC.WantFunctionLikeCasts) {
5218 static const char *const CastableTypeSpecs[] = {
5219 "char", "double", "float", "int", "long", "short",
5220 "signed", "unsigned", "void"
5221 };
5222 for (auto *kw : CastableTypeSpecs)
5223 Consumer.addKeywordResult(Keyword: kw);
5224 }
5225
5226 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
5227 Consumer.addKeywordResult(Keyword: "const_cast");
5228 Consumer.addKeywordResult(Keyword: "dynamic_cast");
5229 Consumer.addKeywordResult(Keyword: "reinterpret_cast");
5230 Consumer.addKeywordResult(Keyword: "static_cast");
5231 }
5232
5233 if (CCC.WantExpressionKeywords) {
5234 Consumer.addKeywordResult(Keyword: "sizeof");
5235 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
5236 Consumer.addKeywordResult(Keyword: "false");
5237 Consumer.addKeywordResult(Keyword: "true");
5238 }
5239
5240 if (SemaRef.getLangOpts().CPlusPlus) {
5241 static const char *const CXXExprs[] = {
5242 "delete", "new", "operator", "throw", "typeid"
5243 };
5244 for (const auto *CE : CXXExprs)
5245 Consumer.addKeywordResult(Keyword: CE);
5246
5247 if (isa<CXXMethodDecl>(Val: SemaRef.CurContext) &&
5248 cast<CXXMethodDecl>(Val: SemaRef.CurContext)->isInstance())
5249 Consumer.addKeywordResult(Keyword: "this");
5250
5251 if (SemaRef.getLangOpts().CPlusPlus11) {
5252 Consumer.addKeywordResult(Keyword: "alignof");
5253 Consumer.addKeywordResult(Keyword: "nullptr");
5254 }
5255 }
5256
5257 if (SemaRef.getLangOpts().C11) {
5258 // FIXME: We should not suggest _Alignof if the alignof macro
5259 // is present.
5260 Consumer.addKeywordResult(Keyword: "_Alignof");
5261 }
5262 }
5263
5264 if (CCC.WantRemainingKeywords) {
5265 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
5266 // Statements.
5267 static const char *const CStmts[] = {
5268 "do", "else", "for", "goto", "if", "return", "switch", "while" };
5269 for (const auto *CS : CStmts)
5270 Consumer.addKeywordResult(Keyword: CS);
5271
5272 if (SemaRef.getLangOpts().CPlusPlus) {
5273 Consumer.addKeywordResult(Keyword: "catch");
5274 Consumer.addKeywordResult(Keyword: "try");
5275 }
5276
5277 if (S && S->getBreakParent())
5278 Consumer.addKeywordResult(Keyword: "break");
5279
5280 if (S && S->getContinueParent())
5281 Consumer.addKeywordResult(Keyword: "continue");
5282
5283 if (SemaRef.getCurFunction() &&
5284 !SemaRef.getCurFunction()->SwitchStack.empty()) {
5285 Consumer.addKeywordResult(Keyword: "case");
5286 Consumer.addKeywordResult(Keyword: "default");
5287 }
5288 } else {
5289 if (SemaRef.getLangOpts().CPlusPlus) {
5290 Consumer.addKeywordResult(Keyword: "namespace");
5291 Consumer.addKeywordResult(Keyword: "template");
5292 }
5293
5294 if (S && S->isClassScope()) {
5295 Consumer.addKeywordResult(Keyword: "explicit");
5296 Consumer.addKeywordResult(Keyword: "friend");
5297 Consumer.addKeywordResult(Keyword: "mutable");
5298 Consumer.addKeywordResult(Keyword: "private");
5299 Consumer.addKeywordResult(Keyword: "protected");
5300 Consumer.addKeywordResult(Keyword: "public");
5301 Consumer.addKeywordResult(Keyword: "virtual");
5302 }
5303 }
5304
5305 if (SemaRef.getLangOpts().CPlusPlus) {
5306 Consumer.addKeywordResult(Keyword: "using");
5307
5308 if (SemaRef.getLangOpts().CPlusPlus11)
5309 Consumer.addKeywordResult(Keyword: "static_assert");
5310 }
5311 }
5312}
5313
5314std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
5315 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
5316 Scope *S, CXXScopeSpec *SS, CorrectionCandidateCallback &CCC,
5317 DeclContext *MemberContext, bool EnteringContext,
5318 const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
5319
5320 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
5321 DisableTypoCorrection)
5322 return nullptr;
5323
5324 // In Microsoft mode, don't perform typo correction in a template member
5325 // function dependent context because it interferes with the "lookup into
5326 // dependent bases of class templates" feature.
5327 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
5328 isa<CXXMethodDecl>(Val: CurContext))
5329 return nullptr;
5330
5331 // We only attempt to correct typos for identifiers.
5332 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
5333 if (!Typo)
5334 return nullptr;
5335
5336 // If the scope specifier itself was invalid, don't try to correct
5337 // typos.
5338 if (SS && SS->isInvalid())
5339 return nullptr;
5340
5341 // Never try to correct typos during any kind of code synthesis.
5342 if (!CodeSynthesisContexts.empty())
5343 return nullptr;
5344
5345 // Don't try to correct 'super'.
5346 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
5347 return nullptr;
5348
5349 // Abort if typo correction already failed for this specific typo.
5350 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Val: Typo);
5351 if (locs != TypoCorrectionFailures.end() &&
5352 locs->second.count(V: TypoName.getLoc()))
5353 return nullptr;
5354
5355 // Don't try to correct the identifier "vector" when in AltiVec mode.
5356 // TODO: Figure out why typo correction misbehaves in this case, fix it, and
5357 // remove this workaround.
5358 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr(Str: "vector"))
5359 return nullptr;
5360
5361 // Provide a stop gap for files that are just seriously broken. Trying
5362 // to correct all typos can turn into a HUGE performance penalty, causing
5363 // some files to take minutes to get rejected by the parser.
5364 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
5365 if (Limit && TyposCorrected >= Limit)
5366 return nullptr;
5367 ++TyposCorrected;
5368
5369 // If we're handling a missing symbol error, using modules, and the
5370 // special search all modules option is used, look for a missing import.
5371 if (ErrorRecovery && getLangOpts().Modules &&
5372 getLangOpts().ModulesSearchAll) {
5373 // The following has the side effect of loading the missing module.
5374 getModuleLoader().lookupMissingImports(Name: Typo->getName(),
5375 TriggerLoc: TypoName.getBeginLoc());
5376 }
5377
5378 // Extend the lifetime of the callback. We delayed this until here
5379 // to avoid allocations in the hot path (which is where no typo correction
5380 // occurs). Note that CorrectionCandidateCallback is polymorphic and
5381 // initially stack-allocated.
5382 std::unique_ptr<CorrectionCandidateCallback> ClonedCCC = CCC.clone();
5383 auto Consumer = std::make_unique<TypoCorrectionConsumer>(
5384 args&: *this, args: TypoName, args&: LookupKind, args&: S, args&: SS, args: std::move(ClonedCCC), args&: MemberContext,
5385 args&: EnteringContext);
5386
5387 // Perform name lookup to find visible, similarly-named entities.
5388 bool IsUnqualifiedLookup = false;
5389 DeclContext *QualifiedDC = MemberContext;
5390 if (MemberContext) {
5391 LookupVisibleDecls(Ctx: MemberContext, Kind: LookupKind, Consumer&: *Consumer);
5392
5393 // Look in qualified interfaces.
5394 if (OPT) {
5395 for (auto *I : OPT->quals())
5396 LookupVisibleDecls(Ctx: I, Kind: LookupKind, Consumer&: *Consumer);
5397 }
5398 } else if (SS && SS->isSet()) {
5399 QualifiedDC = computeDeclContext(SS: *SS, EnteringContext);
5400 if (!QualifiedDC)
5401 return nullptr;
5402
5403 LookupVisibleDecls(Ctx: QualifiedDC, Kind: LookupKind, Consumer&: *Consumer);
5404 } else {
5405 IsUnqualifiedLookup = true;
5406 }
5407
5408 // Determine whether we are going to search in the various namespaces for
5409 // corrections.
5410 bool SearchNamespaces
5411 = getLangOpts().CPlusPlus &&
5412 (IsUnqualifiedLookup || (SS && SS->isSet()));
5413
5414 if (IsUnqualifiedLookup || SearchNamespaces) {
5415 // For unqualified lookup, look through all of the names that we have
5416 // seen in this translation unit.
5417 // FIXME: Re-add the ability to skip very unlikely potential corrections.
5418 for (const auto &I : Context.Idents)
5419 Consumer->FoundName(Name: I.getKey());
5420
5421 // Walk through identifiers in external identifier sources.
5422 // FIXME: Re-add the ability to skip very unlikely potential corrections.
5423 if (IdentifierInfoLookup *External
5424 = Context.Idents.getExternalIdentifierLookup()) {
5425 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
5426 do {
5427 StringRef Name = Iter->Next();
5428 if (Name.empty())
5429 break;
5430
5431 Consumer->FoundName(Name);
5432 } while (true);
5433 }
5434 }
5435
5436 AddKeywordsToConsumer(SemaRef&: *this, Consumer&: *Consumer, S,
5437 CCC&: *Consumer->getCorrectionValidator(),
5438 AfterNestedNameSpecifier: SS && SS->isNotEmpty());
5439
5440 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
5441 // to search those namespaces.
5442 if (SearchNamespaces) {
5443 // Load any externally-known namespaces.
5444 if (ExternalSource && !LoadedExternalKnownNamespaces) {
5445 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
5446 LoadedExternalKnownNamespaces = true;
5447 ExternalSource->ReadKnownNamespaces(Namespaces&: ExternalKnownNamespaces);
5448 for (auto *N : ExternalKnownNamespaces)
5449 KnownNamespaces[N] = true;
5450 }
5451
5452 Consumer->addNamespaces(KnownNamespaces);
5453 }
5454
5455 return Consumer;
5456}
5457
5458TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
5459 Sema::LookupNameKind LookupKind,
5460 Scope *S, CXXScopeSpec *SS,
5461 CorrectionCandidateCallback &CCC,
5462 CorrectTypoKind Mode,
5463 DeclContext *MemberContext,
5464 bool EnteringContext,
5465 const ObjCObjectPointerType *OPT,
5466 bool RecordFailure) {
5467 // Always let the ExternalSource have the first chance at correction, even
5468 // if we would otherwise have given up.
5469 if (ExternalSource) {
5470 if (TypoCorrection Correction =
5471 ExternalSource->CorrectTypo(Typo: TypoName, LookupKind, S, SS, CCC,
5472 MemberContext, EnteringContext, OPT))
5473 return Correction;
5474 }
5475
5476 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
5477 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
5478 // some instances of CTC_Unknown, while WantRemainingKeywords is true
5479 // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
5480 bool ObjCMessageReceiver = CCC.WantObjCSuper && !CCC.WantRemainingKeywords;
5481
5482 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
5483 auto Consumer = makeTypoCorrectionConsumer(
5484 TypoName, LookupKind, S, SS, CCC, MemberContext, EnteringContext, OPT,
5485 ErrorRecovery: Mode == CorrectTypoKind::ErrorRecovery);
5486
5487 if (!Consumer)
5488 return TypoCorrection();
5489
5490 // If we haven't found anything, we're done.
5491 if (Consumer->empty())
5492 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure);
5493
5494 // Make sure the best edit distance (prior to adding any namespace qualifiers)
5495 // is not more that about a third of the length of the typo's identifier.
5496 unsigned ED = Consumer->getBestEditDistance(Normalized: true);
5497 unsigned TypoLen = Typo->getName().size();
5498 if (ED > 0 && TypoLen / ED < 3)
5499 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure);
5500
5501 TypoCorrection BestTC = Consumer->getNextCorrection();
5502 TypoCorrection SecondBestTC = Consumer->getNextCorrection();
5503 if (!BestTC)
5504 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure);
5505
5506 ED = BestTC.getEditDistance();
5507
5508 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
5509 // If this was an unqualified lookup and we believe the callback
5510 // object wouldn't have filtered out possible corrections, note
5511 // that no correction was found.
5512 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure);
5513 }
5514
5515 // If only a single name remains, return that result.
5516 if (!SecondBestTC ||
5517 SecondBestTC.getEditDistance(Normalized: false) > BestTC.getEditDistance(Normalized: false)) {
5518 const TypoCorrection &Result = BestTC;
5519
5520 // Don't correct to a keyword that's the same as the typo; the keyword
5521 // wasn't actually in scope.
5522 if (ED == 0 && Result.isKeyword())
5523 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure);
5524
5525 TypoCorrection TC = Result;
5526 TC.setCorrectionRange(SS, TypoName);
5527 checkCorrectionVisibility(SemaRef&: *this, TC);
5528 return TC;
5529 } else if (SecondBestTC && ObjCMessageReceiver) {
5530 // Prefer 'super' when we're completing in a message-receiver
5531 // context.
5532
5533 if (BestTC.getCorrection().getAsString() != "super") {
5534 if (SecondBestTC.getCorrection().getAsString() == "super")
5535 BestTC = std::move(SecondBestTC);
5536 else if ((*Consumer)["super"].front().isKeyword())
5537 BestTC = (*Consumer)["super"].front();
5538 }
5539 // Don't correct to a keyword that's the same as the typo; the keyword
5540 // wasn't actually in scope.
5541 if (BestTC.getEditDistance() == 0 ||
5542 BestTC.getCorrection().getAsString() != "super")
5543 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure);
5544
5545 BestTC.setCorrectionRange(SS, TypoName);
5546 return BestTC;
5547 }
5548
5549 // Record the failure's location if needed and return an empty correction. If
5550 // this was an unqualified lookup and we believe the callback object did not
5551 // filter out possible corrections, also cache the failure for the typo.
5552 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure: RecordFailure && !SecondBestTC);
5553}
5554
5555void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) {
5556 if (!CDecl) return;
5557
5558 if (isKeyword())
5559 CorrectionDecls.clear();
5560
5561 CorrectionDecls.push_back(Elt: CDecl);
5562
5563 if (!CorrectionName)
5564 CorrectionName = CDecl->getDeclName();
5565}
5566
5567std::string TypoCorrection::getAsString(const LangOptions &LO) const {
5568 if (CorrectionNameSpec) {
5569 std::string tmpBuffer;
5570 llvm::raw_string_ostream PrefixOStream(tmpBuffer);
5571 CorrectionNameSpec.print(OS&: PrefixOStream, Policy: PrintingPolicy(LO));
5572 PrefixOStream << CorrectionName;
5573 return PrefixOStream.str();
5574 }
5575
5576 return CorrectionName.getAsString();
5577}
5578
5579bool CorrectionCandidateCallback::ValidateCandidate(
5580 const TypoCorrection &candidate) {
5581 if (!candidate.isResolved())
5582 return true;
5583
5584 if (candidate.isKeyword())
5585 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
5586 WantRemainingKeywords || WantObjCSuper;
5587
5588 bool HasNonType = false;
5589 bool HasStaticMethod = false;
5590 bool HasNonStaticMethod = false;
5591 for (Decl *D : candidate) {
5592 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(Val: D))
5593 D = FTD->getTemplatedDecl();
5594 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Val: D)) {
5595 if (Method->isStatic())
5596 HasStaticMethod = true;
5597 else
5598 HasNonStaticMethod = true;
5599 }
5600 if (!isa<TypeDecl>(Val: D))
5601 HasNonType = true;
5602 }
5603
5604 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
5605 !candidate.getCorrectionSpecifier())
5606 return false;
5607
5608 return WantTypeSpecifiers || HasNonType;
5609}
5610
5611FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs,
5612 bool HasExplicitTemplateArgs,
5613 MemberExpr *ME)
5614 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
5615 CurContext(SemaRef.CurContext), MemberFn(ME) {
5616 WantTypeSpecifiers = false;
5617 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus &&
5618 !HasExplicitTemplateArgs && NumArgs == 1;
5619 WantCXXNamedCasts = HasExplicitTemplateArgs && NumArgs == 1;
5620 WantRemainingKeywords = false;
5621}
5622
5623bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) {
5624 if (!candidate.getCorrectionDecl())
5625 return candidate.isKeyword();
5626
5627 for (auto *C : candidate) {
5628 FunctionDecl *FD = nullptr;
5629 NamedDecl *ND = C->getUnderlyingDecl();
5630 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(Val: ND))
5631 FD = FTD->getTemplatedDecl();
5632 if (!HasExplicitTemplateArgs && !FD) {
5633 if (!(FD = dyn_cast<FunctionDecl>(Val: ND)) && isa<ValueDecl>(Val: ND)) {
5634 // If the Decl is neither a function nor a template function,
5635 // determine if it is a pointer or reference to a function. If so,
5636 // check against the number of arguments expected for the pointee.
5637 QualType ValType = cast<ValueDecl>(Val: ND)->getType();
5638 if (ValType.isNull())
5639 continue;
5640 if (ValType->isAnyPointerType() || ValType->isReferenceType())
5641 ValType = ValType->getPointeeType();
5642 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
5643 if (FPT->getNumParams() == NumArgs)
5644 return true;
5645 }
5646 }
5647
5648 // A typo for a function-style cast can look like a function call in C++.
5649 if ((HasExplicitTemplateArgs ? getAsTypeTemplateDecl(D: ND) != nullptr
5650 : isa<TypeDecl>(Val: ND)) &&
5651 CurContext->getParentASTContext().getLangOpts().CPlusPlus)
5652 // Only a class or class template can take two or more arguments.
5653 return NumArgs <= 1 || HasExplicitTemplateArgs || isa<CXXRecordDecl>(Val: ND);
5654
5655 // Skip the current candidate if it is not a FunctionDecl or does not accept
5656 // the current number of arguments.
5657 if (!FD || !(FD->getNumParams() >= NumArgs &&
5658 FD->getMinRequiredArguments() <= NumArgs))
5659 continue;
5660
5661 // If the current candidate is a non-static C++ method, skip the candidate
5662 // unless the method being corrected--or the current DeclContext, if the
5663 // function being corrected is not a method--is a method in the same class
5664 // or a descendent class of the candidate's parent class.
5665 if (const auto *MD = dyn_cast<CXXMethodDecl>(Val: FD)) {
5666 if (MemberFn || !MD->isStatic()) {
5667 const auto *CurMD =
5668 MemberFn
5669 ? dyn_cast_if_present<CXXMethodDecl>(Val: MemberFn->getMemberDecl())
5670 : dyn_cast_if_present<CXXMethodDecl>(Val: CurContext);
5671 const CXXRecordDecl *CurRD =
5672 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
5673 const CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
5674 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(Base: RD)))
5675 continue;
5676 }
5677 }
5678 return true;
5679 }
5680 return false;
5681}
5682
5683void Sema::diagnoseTypo(const TypoCorrection &Correction,
5684 const PartialDiagnostic &TypoDiag,
5685 bool ErrorRecovery) {
5686 diagnoseTypo(Correction, TypoDiag, PrevNote: PDiag(DiagID: diag::note_previous_decl),
5687 ErrorRecovery);
5688}
5689
5690/// Find which declaration we should import to provide the definition of
5691/// the given declaration.
5692static const NamedDecl *getDefinitionToImport(const NamedDecl *D) {
5693 if (const auto *VD = dyn_cast<VarDecl>(Val: D))
5694 return VD->getDefinition();
5695 if (const auto *FD = dyn_cast<FunctionDecl>(Val: D))
5696 return FD->getDefinition();
5697 if (const auto *TD = dyn_cast<TagDecl>(Val: D))
5698 return TD->getDefinition();
5699 if (const auto *ID = dyn_cast<ObjCInterfaceDecl>(Val: D))
5700 return ID->getDefinition();
5701 if (const auto *PD = dyn_cast<ObjCProtocolDecl>(Val: D))
5702 return PD->getDefinition();
5703 if (const auto *TD = dyn_cast<TemplateDecl>(Val: D))
5704 if (const NamedDecl *TTD = TD->getTemplatedDecl())
5705 return getDefinitionToImport(D: TTD);
5706 return nullptr;
5707}
5708
5709void Sema::diagnoseMissingImport(SourceLocation Loc, const NamedDecl *Decl,
5710 MissingImportKind MIK, bool Recover) {
5711 // Suggest importing a module providing the definition of this entity, if
5712 // possible.
5713 const NamedDecl *Def = getDefinitionToImport(D: Decl);
5714 if (!Def)
5715 Def = Decl;
5716
5717 Module *Owner = getOwningModule(Entity: Def);
5718 assert(Owner && "definition of hidden declaration is not in a module");
5719
5720 llvm::SmallVector<Module*, 8> OwningModules;
5721 OwningModules.push_back(Elt: Owner);
5722 auto Merged = Context.getModulesWithMergedDefinition(Def);
5723 llvm::append_range(C&: OwningModules, R&: Merged);
5724
5725 diagnoseMissingImport(Loc, Decl: Def, DeclLoc: Def->getLocation(), Modules: OwningModules, MIK,
5726 Recover);
5727}
5728
5729/// Get a "quoted.h" or <angled.h> include path to use in a diagnostic
5730/// suggesting the addition of a #include of the specified file.
5731static std::string getHeaderNameForHeader(Preprocessor &PP, FileEntryRef E,
5732 llvm::StringRef IncludingFile) {
5733 bool IsAngled = false;
5734 auto Path = PP.getHeaderSearchInfo().suggestPathToFileForDiagnostics(
5735 File: E, MainFile: IncludingFile, IsAngled: &IsAngled);
5736 return (IsAngled ? '<' : '"') + Path + (IsAngled ? '>' : '"');
5737}
5738
5739void Sema::diagnoseMissingImport(SourceLocation UseLoc, const NamedDecl *Decl,
5740 SourceLocation DeclLoc,
5741 ArrayRef<Module *> Modules,
5742 MissingImportKind MIK, bool Recover) {
5743 assert(!Modules.empty());
5744
5745 // See https://github.com/llvm/llvm-project/issues/73893. It is generally
5746 // confusing than helpful to show the namespace is not visible.
5747 if (isa<NamespaceDecl>(Val: Decl))
5748 return;
5749
5750 auto NotePrevious = [&] {
5751 // FIXME: Suppress the note backtrace even under
5752 // -fdiagnostics-show-note-include-stack. We don't care how this
5753 // declaration was previously reached.
5754 Diag(Loc: DeclLoc, DiagID: diag::note_unreachable_entity) << (int)MIK;
5755 };
5756
5757 // Weed out duplicates from module list.
5758 llvm::SmallVector<Module*, 8> UniqueModules;
5759 llvm::SmallDenseSet<Module*, 8> UniqueModuleSet;
5760 for (auto *M : Modules) {
5761 if (M->isExplicitGlobalModule() || M->isPrivateModule())
5762 continue;
5763 if (UniqueModuleSet.insert(V: M).second)
5764 UniqueModules.push_back(Elt: M);
5765 }
5766
5767 // Try to find a suitable header-name to #include.
5768 std::string HeaderName;
5769 if (OptionalFileEntryRef Header =
5770 PP.getHeaderToIncludeForDiagnostics(IncLoc: UseLoc, MLoc: DeclLoc)) {
5771 if (const FileEntry *FE =
5772 SourceMgr.getFileEntryForID(FID: SourceMgr.getFileID(SpellingLoc: UseLoc)))
5773 HeaderName =
5774 getHeaderNameForHeader(PP, E: *Header, IncludingFile: FE->tryGetRealPathName());
5775 }
5776
5777 // If we have a #include we should suggest, or if all definition locations
5778 // were in global module fragments, don't suggest an import.
5779 if (!HeaderName.empty() || UniqueModules.empty()) {
5780 // FIXME: Find a smart place to suggest inserting a #include, and add
5781 // a FixItHint there.
5782 Diag(Loc: UseLoc, DiagID: diag::err_module_unimported_use_header)
5783 << (int)MIK << Decl << !HeaderName.empty() << HeaderName;
5784 // Produce a note showing where the entity was declared.
5785 NotePrevious();
5786 if (Recover)
5787 createImplicitModuleImportForErrorRecovery(Loc: UseLoc, Mod: Modules[0]);
5788 return;
5789 }
5790
5791 Modules = UniqueModules;
5792
5793 auto GetModuleNameForDiagnostic = [this](const Module *M) -> std::string {
5794 if (M->isModuleMapModule())
5795 return M->getFullModuleName();
5796
5797 if (M->isImplicitGlobalModule())
5798 M = M->getTopLevelModule();
5799
5800 // If the current module unit is in the same module with M, it is OK to show
5801 // the partition name. Otherwise, it'll be sufficient to show the primary
5802 // module name.
5803 if (getASTContext().isInSameModule(M1: M, M2: getCurrentModule()))
5804 return M->getTopLevelModuleName().str();
5805 else
5806 return M->getPrimaryModuleInterfaceName().str();
5807 };
5808
5809 if (Modules.size() > 1) {
5810 std::string ModuleList;
5811 unsigned N = 0;
5812 for (const auto *M : Modules) {
5813 ModuleList += "\n ";
5814 if (++N == 5 && N != Modules.size()) {
5815 ModuleList += "[...]";
5816 break;
5817 }
5818 ModuleList += GetModuleNameForDiagnostic(M);
5819 }
5820
5821 Diag(Loc: UseLoc, DiagID: diag::err_module_unimported_use_multiple)
5822 << (int)MIK << Decl << ModuleList;
5823 } else {
5824 // FIXME: Add a FixItHint that imports the corresponding module.
5825 Diag(Loc: UseLoc, DiagID: diag::err_module_unimported_use)
5826 << (int)MIK << Decl << GetModuleNameForDiagnostic(Modules[0]);
5827 }
5828
5829 NotePrevious();
5830
5831 // Try to recover by implicitly importing this module.
5832 if (Recover)
5833 createImplicitModuleImportForErrorRecovery(Loc: UseLoc, Mod: Modules[0]);
5834}
5835
5836void Sema::diagnoseTypo(const TypoCorrection &Correction,
5837 const PartialDiagnostic &TypoDiag,
5838 const PartialDiagnostic &PrevNote,
5839 bool ErrorRecovery) {
5840 std::string CorrectedStr = Correction.getAsString(LO: getLangOpts());
5841 std::string CorrectedQuotedStr = Correction.getQuoted(LO: getLangOpts());
5842 FixItHint FixTypo = FixItHint::CreateReplacement(
5843 RemoveRange: Correction.getCorrectionRange(), Code: CorrectedStr);
5844
5845 // Maybe we're just missing a module import.
5846 if (Correction.requiresImport()) {
5847 NamedDecl *Decl = Correction.getFoundDecl();
5848 assert(Decl && "import required but no declaration to import");
5849
5850 diagnoseMissingImport(Loc: Correction.getCorrectionRange().getBegin(), Decl,
5851 MIK: MissingImportKind::Declaration, Recover: ErrorRecovery);
5852 return;
5853 }
5854
5855 Diag(Loc: Correction.getCorrectionRange().getBegin(), PD: TypoDiag)
5856 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
5857
5858 NamedDecl *ChosenDecl =
5859 Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
5860
5861 // For builtin functions which aren't declared anywhere in source,
5862 // don't emit the "declared here" note.
5863 if (const auto *FD = dyn_cast_if_present<FunctionDecl>(Val: ChosenDecl);
5864 FD && FD->getBuiltinID() &&
5865 PrevNote.getDiagID() == diag::note_previous_decl &&
5866 Correction.getCorrectionRange().getBegin() == FD->getBeginLoc()) {
5867 ChosenDecl = nullptr;
5868 }
5869
5870 if (PrevNote.getDiagID() && ChosenDecl)
5871 Diag(Loc: ChosenDecl->getLocation(), PD: PrevNote)
5872 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
5873
5874 // Add any extra diagnostics.
5875 for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
5876 Diag(Loc: Correction.getCorrectionRange().getBegin(), PD);
5877}
5878
5879void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) {
5880 DeclarationNameInfo Name(II, IILoc);
5881 LookupResult R(*this, Name, LookupAnyName,
5882 RedeclarationKind::NotForRedeclaration);
5883 R.suppressDiagnostics();
5884 R.setHideTags(false);
5885 LookupName(R, S);
5886 R.dump();
5887}
5888
5889void Sema::ActOnPragmaDump(Expr *E) {
5890 E->dump();
5891}
5892
5893RedeclarationKind Sema::forRedeclarationInCurContext() const {
5894 // A declaration with an owning module for linkage can never link against
5895 // anything that is not visible. We don't need to check linkage here; if
5896 // the context has internal linkage, redeclaration lookup won't find things
5897 // from other TUs, and we can't safely compute linkage yet in general.
5898 if (cast<Decl>(Val: CurContext)->getOwningModuleForLinkage())
5899 return RedeclarationKind::ForVisibleRedeclaration;
5900 return RedeclarationKind::ForExternalRedeclaration;
5901}
5902