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::sort(C&: list, Comp: 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->setVisibleDespiteOwningModule();
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;
1593 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Val: Entity)) {
1594 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1595 Entity = Pattern;
1596 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Val: Entity)) {
1597 if (auto *Pattern = ED->getTemplateInstantiationPattern())
1598 Entity = Pattern;
1599 } else if (VarDecl *VD = dyn_cast<VarDecl>(Val: Entity)) {
1600 if (VarDecl *Pattern = VD->getTemplateInstantiationPattern())
1601 Entity = Pattern;
1602 }
1603
1604 // Walk up to the containing context. That might also have been instantiated
1605 // from a template.
1606 DeclContext *Context = Entity->getLexicalDeclContext();
1607 if (Context->isFileContext())
1608 return S.getOwningModule(Entity);
1609 return getDefiningModule(S, Entity: cast<Decl>(Val: Context));
1610}
1611
1612llvm::DenseSet<Module*> &Sema::getLookupModules() {
1613 unsigned N = CodeSynthesisContexts.size();
1614 for (unsigned I = CodeSynthesisContextLookupModules.size();
1615 I != N; ++I) {
1616 Module *M = CodeSynthesisContexts[I].Entity ?
1617 getDefiningModule(S&: *this, Entity: CodeSynthesisContexts[I].Entity) :
1618 nullptr;
1619 if (M && !LookupModulesCache.insert(V: M).second)
1620 M = nullptr;
1621 CodeSynthesisContextLookupModules.push_back(Elt: M);
1622 }
1623 return LookupModulesCache;
1624}
1625
1626bool Sema::isUsableModule(const Module *M) {
1627 assert(M && "We shouldn't check nullness for module here");
1628 // Return quickly if we cached the result.
1629 if (UsableModuleUnitsCache.count(V: M))
1630 return true;
1631
1632 // If M is the global module fragment of the current translation unit. So it
1633 // should be usable.
1634 // [module.global.frag]p1:
1635 // The global module fragment can be used to provide declarations that are
1636 // attached to the global module and usable within the module unit.
1637 if (M == TheGlobalModuleFragment || M == TheImplicitGlobalModuleFragment) {
1638 UsableModuleUnitsCache.insert(V: M);
1639 return true;
1640 }
1641
1642 // Otherwise, the global module fragment from other translation unit is not
1643 // directly usable.
1644 if (M->isExplicitGlobalModule())
1645 return false;
1646
1647 Module *Current = getCurrentModule();
1648
1649 // If we're not parsing a module, we can't use all the declarations from
1650 // another module easily.
1651 if (!Current)
1652 return false;
1653
1654 // For implicit global module, the decls in the same modules with the parent
1655 // module should be visible to the decls in the implicit global module.
1656 if (Current->isImplicitGlobalModule())
1657 Current = Current->getTopLevelModule();
1658 if (M->isImplicitGlobalModule())
1659 M = M->getTopLevelModule();
1660
1661 // If M is the module we're parsing or M and the current module unit lives in
1662 // the same module, M should be usable.
1663 //
1664 // Note: It should be fine to search the vector `ModuleScopes` linearly since
1665 // it should be generally small enough. There should be rare module fragments
1666 // in a named module unit.
1667 if (llvm::count_if(Range&: ModuleScopes,
1668 P: [&M](const ModuleScope &MS) { return MS.Module == M; }) ||
1669 getASTContext().isInSameModule(M1: M, M2: Current)) {
1670 UsableModuleUnitsCache.insert(V: M);
1671 return true;
1672 }
1673
1674 return false;
1675}
1676
1677bool Sema::hasVisibleMergedDefinition(const NamedDecl *Def) {
1678 for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1679 if (isModuleVisible(M: Merged))
1680 return true;
1681 return false;
1682}
1683
1684bool Sema::hasMergedDefinitionInCurrentModule(const NamedDecl *Def) {
1685 for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1686 if (isUsableModule(M: Merged))
1687 return true;
1688 return false;
1689}
1690
1691template <typename ParmDecl>
1692static bool
1693hasAcceptableDefaultArgument(Sema &S, const ParmDecl *D,
1694 llvm::SmallVectorImpl<Module *> *Modules,
1695 Sema::AcceptableKind Kind) {
1696 if (!D->hasDefaultArgument())
1697 return false;
1698
1699 llvm::SmallPtrSet<const ParmDecl *, 4> Visited;
1700 while (D && Visited.insert(D).second) {
1701 auto &DefaultArg = D->getDefaultArgStorage();
1702 if (!DefaultArg.isInherited() && S.isAcceptable(D, Kind))
1703 return true;
1704
1705 if (!DefaultArg.isInherited() && Modules) {
1706 auto *NonConstD = const_cast<ParmDecl*>(D);
1707 Modules->push_back(Elt: S.getOwningModule(Entity: NonConstD));
1708 }
1709
1710 // If there was a previous default argument, maybe its parameter is
1711 // acceptable.
1712 D = DefaultArg.getInheritedFrom();
1713 }
1714 return false;
1715}
1716
1717bool Sema::hasAcceptableDefaultArgument(
1718 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules,
1719 Sema::AcceptableKind Kind) {
1720 if (auto *P = dyn_cast<TemplateTypeParmDecl>(Val: D))
1721 return ::hasAcceptableDefaultArgument(S&: *this, D: P, Modules, Kind);
1722
1723 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(Val: D))
1724 return ::hasAcceptableDefaultArgument(S&: *this, D: P, Modules, Kind);
1725
1726 return ::hasAcceptableDefaultArgument(
1727 S&: *this, D: cast<TemplateTemplateParmDecl>(Val: D), Modules, Kind);
1728}
1729
1730bool Sema::hasVisibleDefaultArgument(const NamedDecl *D,
1731 llvm::SmallVectorImpl<Module *> *Modules) {
1732 return hasAcceptableDefaultArgument(D, Modules,
1733 Kind: Sema::AcceptableKind::Visible);
1734}
1735
1736bool Sema::hasReachableDefaultArgument(
1737 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1738 return hasAcceptableDefaultArgument(D, Modules,
1739 Kind: Sema::AcceptableKind::Reachable);
1740}
1741
1742template <typename Filter>
1743static bool
1744hasAcceptableDeclarationImpl(Sema &S, const NamedDecl *D,
1745 llvm::SmallVectorImpl<Module *> *Modules, Filter F,
1746 Sema::AcceptableKind Kind) {
1747 bool HasFilteredRedecls = false;
1748
1749 for (auto *Redecl : D->redecls()) {
1750 auto *R = cast<NamedDecl>(Val: Redecl);
1751 if (!F(R))
1752 continue;
1753
1754 if (S.isAcceptable(D: R, Kind))
1755 return true;
1756
1757 HasFilteredRedecls = true;
1758
1759 if (Modules)
1760 Modules->push_back(Elt: R->getOwningModule());
1761 }
1762
1763 // Only return false if there is at least one redecl that is not filtered out.
1764 if (HasFilteredRedecls)
1765 return false;
1766
1767 return true;
1768}
1769
1770static bool
1771hasAcceptableExplicitSpecialization(Sema &S, const NamedDecl *D,
1772 llvm::SmallVectorImpl<Module *> *Modules,
1773 Sema::AcceptableKind Kind) {
1774 return hasAcceptableDeclarationImpl(
1775 S, D, Modules,
1776 F: [](const NamedDecl *D) {
1777 if (auto *RD = dyn_cast<CXXRecordDecl>(Val: D))
1778 return RD->getTemplateSpecializationKind() ==
1779 TSK_ExplicitSpecialization;
1780 if (auto *FD = dyn_cast<FunctionDecl>(Val: D))
1781 return FD->getTemplateSpecializationKind() ==
1782 TSK_ExplicitSpecialization;
1783 if (auto *VD = dyn_cast<VarDecl>(Val: D))
1784 return VD->getTemplateSpecializationKind() ==
1785 TSK_ExplicitSpecialization;
1786 llvm_unreachable("unknown explicit specialization kind");
1787 },
1788 Kind);
1789}
1790
1791bool Sema::hasVisibleExplicitSpecialization(
1792 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1793 return ::hasAcceptableExplicitSpecialization(S&: *this, D, Modules,
1794 Kind: Sema::AcceptableKind::Visible);
1795}
1796
1797bool Sema::hasReachableExplicitSpecialization(
1798 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1799 return ::hasAcceptableExplicitSpecialization(S&: *this, D, Modules,
1800 Kind: Sema::AcceptableKind::Reachable);
1801}
1802
1803static bool
1804hasAcceptableMemberSpecialization(Sema &S, const NamedDecl *D,
1805 llvm::SmallVectorImpl<Module *> *Modules,
1806 Sema::AcceptableKind Kind) {
1807 assert(isa<CXXRecordDecl>(D->getDeclContext()) &&
1808 "not a member specialization");
1809 return hasAcceptableDeclarationImpl(
1810 S, D, Modules,
1811 F: [](const NamedDecl *D) {
1812 // If the specialization is declared at namespace scope, then it's a
1813 // member specialization declaration. If it's lexically inside the class
1814 // definition then it was instantiated.
1815 //
1816 // FIXME: This is a hack. There should be a better way to determine
1817 // this.
1818 // FIXME: What about MS-style explicit specializations declared within a
1819 // class definition?
1820 return D->getLexicalDeclContext()->isFileContext();
1821 },
1822 Kind);
1823}
1824
1825bool Sema::hasVisibleMemberSpecialization(
1826 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1827 return hasAcceptableMemberSpecialization(S&: *this, D, Modules,
1828 Kind: Sema::AcceptableKind::Visible);
1829}
1830
1831bool Sema::hasReachableMemberSpecialization(
1832 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1833 return hasAcceptableMemberSpecialization(S&: *this, D, Modules,
1834 Kind: Sema::AcceptableKind::Reachable);
1835}
1836
1837/// Determine whether a declaration is acceptable to name lookup.
1838///
1839/// This routine determines whether the declaration D is acceptable in the
1840/// current lookup context, taking into account the current template
1841/// instantiation stack. During template instantiation, a declaration is
1842/// acceptable if it is acceptable from a module containing any entity on the
1843/// template instantiation path (by instantiating a template, you allow it to
1844/// see the declarations that your module can see, including those later on in
1845/// your module).
1846bool LookupResult::isAcceptableSlow(Sema &SemaRef, NamedDecl *D,
1847 Sema::AcceptableKind Kind) {
1848 assert(!D->isUnconditionallyVisible() &&
1849 "should not call this: not in slow case");
1850
1851 Module *DeclModule = SemaRef.getOwningModule(Entity: D);
1852 assert(DeclModule && "hidden decl has no owning module");
1853
1854 // If the owning module is visible, the decl is acceptable.
1855 if (SemaRef.isModuleVisible(M: DeclModule,
1856 ModulePrivate: D->isInvisibleOutsideTheOwningModule()))
1857 return true;
1858
1859 // Determine whether a decl context is a file context for the purpose of
1860 // visibility/reachability. This looks through some (export and linkage spec)
1861 // transparent contexts, but not others (enums).
1862 auto IsEffectivelyFileContext = [](const DeclContext *DC) {
1863 return DC->isFileContext() || isa<LinkageSpecDecl>(Val: DC) ||
1864 isa<ExportDecl>(Val: DC);
1865 };
1866
1867 // If this declaration is not at namespace scope
1868 // then it is acceptable if its lexical parent has a acceptable definition.
1869 DeclContext *DC = D->getLexicalDeclContext();
1870 if (DC && !IsEffectivelyFileContext(DC)) {
1871 // For a parameter, check whether our current template declaration's
1872 // lexical context is acceptable, not whether there's some other acceptable
1873 // definition of it, because parameters aren't "within" the definition.
1874 //
1875 // In C++ we need to check for a acceptable definition due to ODR merging,
1876 // and in C we must not because each declaration of a function gets its own
1877 // set of declarations for tags in prototype scope.
1878 bool AcceptableWithinParent;
1879 if (D->isTemplateParameter()) {
1880 bool SearchDefinitions = true;
1881 if (const auto *DCD = dyn_cast<Decl>(Val: DC)) {
1882 if (const auto *TD = DCD->getDescribedTemplate()) {
1883 TemplateParameterList *TPL = TD->getTemplateParameters();
1884 auto Index = getDepthAndIndex(ND: D).second;
1885 SearchDefinitions = Index >= TPL->size() || TPL->getParam(Idx: Index) != D;
1886 }
1887 }
1888 if (SearchDefinitions)
1889 AcceptableWithinParent =
1890 SemaRef.hasAcceptableDefinition(D: cast<NamedDecl>(Val: DC), Kind);
1891 else
1892 AcceptableWithinParent =
1893 isAcceptable(SemaRef, D: cast<NamedDecl>(Val: DC), Kind);
1894 } else if (isa<ParmVarDecl>(Val: D) ||
1895 (isa<FunctionDecl>(Val: DC) && !SemaRef.getLangOpts().CPlusPlus))
1896 AcceptableWithinParent = isAcceptable(SemaRef, D: cast<NamedDecl>(Val: DC), Kind);
1897 else if (D->isModulePrivate()) {
1898 // A module-private declaration is only acceptable if an enclosing lexical
1899 // parent was merged with another definition in the current module.
1900 AcceptableWithinParent = false;
1901 do {
1902 if (SemaRef.hasMergedDefinitionInCurrentModule(Def: cast<NamedDecl>(Val: DC))) {
1903 AcceptableWithinParent = true;
1904 break;
1905 }
1906 DC = DC->getLexicalParent();
1907 } while (!IsEffectivelyFileContext(DC));
1908 } else {
1909 AcceptableWithinParent =
1910 SemaRef.hasAcceptableDefinition(D: cast<NamedDecl>(Val: DC), Kind);
1911 }
1912
1913 if (AcceptableWithinParent && SemaRef.CodeSynthesisContexts.empty() &&
1914 Kind == Sema::AcceptableKind::Visible &&
1915 // FIXME: Do something better in this case.
1916 !SemaRef.getLangOpts().ModulesLocalVisibility) {
1917 // Cache the fact that this declaration is implicitly visible because
1918 // its parent has a visible definition.
1919 D->setVisibleDespiteOwningModule();
1920 }
1921 return AcceptableWithinParent;
1922 }
1923
1924 if (Kind == Sema::AcceptableKind::Visible)
1925 return false;
1926
1927 assert(Kind == Sema::AcceptableKind::Reachable &&
1928 "Additional Sema::AcceptableKind?");
1929 return isReachableSlow(SemaRef, D);
1930}
1931
1932bool Sema::isModuleVisible(const Module *M, bool ModulePrivate) {
1933 // The module might be ordinarily visible. For a module-private query, that
1934 // means it is part of the current module.
1935 if (ModulePrivate && isUsableModule(M))
1936 return true;
1937
1938 // For a query which is not module-private, that means it is in our visible
1939 // module set.
1940 if (!ModulePrivate && VisibleModules.isVisible(M))
1941 return true;
1942
1943 // Otherwise, it might be visible by virtue of the query being within a
1944 // template instantiation or similar that is permitted to look inside M.
1945
1946 // Find the extra places where we need to look.
1947 const auto &LookupModules = getLookupModules();
1948 if (LookupModules.empty())
1949 return false;
1950
1951 // If our lookup set contains the module, it's visible.
1952 if (LookupModules.count(V: M))
1953 return true;
1954
1955 // The global module fragments are visible to its corresponding module unit.
1956 // So the global module fragment should be visible if the its corresponding
1957 // module unit is visible.
1958 if (M->isGlobalModule() && LookupModules.count(V: M->getTopLevelModule()))
1959 return true;
1960
1961 // For a module-private query, that's everywhere we get to look.
1962 if (ModulePrivate)
1963 return false;
1964
1965 // Check whether M is transitively exported to an import of the lookup set.
1966 return llvm::any_of(Range: LookupModules, P: [&](const Module *LookupM) {
1967 return LookupM->isModuleVisible(M);
1968 });
1969}
1970
1971// FIXME: Return false directly if we don't have an interface dependency on the
1972// translation unit containing D.
1973bool LookupResult::isReachableSlow(Sema &SemaRef, NamedDecl *D) {
1974 assert(!isVisible(SemaRef, D) && "Shouldn't call the slow case.\n");
1975
1976 Module *DeclModule = SemaRef.getOwningModule(Entity: D);
1977 assert(DeclModule && "hidden decl has no owning module");
1978
1979 // Entities in header like modules are reachable only if they're visible.
1980 if (DeclModule->isHeaderLikeModule())
1981 return false;
1982
1983 if (!D->isInAnotherModuleUnit())
1984 return true;
1985
1986 // [module.reach]/p3:
1987 // A declaration D is reachable from a point P if:
1988 // ...
1989 // - D is not discarded ([module.global.frag]), appears in a translation unit
1990 // that is reachable from P, and does not appear within a private module
1991 // fragment.
1992 //
1993 // A declaration that's discarded in the GMF should be module-private.
1994 if (D->isModulePrivate())
1995 return false;
1996
1997 Module *DeclTopModule = DeclModule->getTopLevelModule();
1998
1999 // [module.reach]/p1
2000 // A translation unit U is necessarily reachable from a point P if U is a
2001 // module interface unit on which the translation unit containing P has an
2002 // interface dependency, or the translation unit containing P imports U, in
2003 // either case prior to P ([module.import]).
2004 //
2005 // [module.import]/p10
2006 // A translation unit has an interface dependency on a translation unit U if
2007 // it contains a declaration (possibly a module-declaration) that imports U
2008 // or if it has an interface dependency on a translation unit that has an
2009 // interface dependency on U.
2010 //
2011 // So we could conclude the module unit U is necessarily reachable if:
2012 // (1) The module unit U is module interface unit.
2013 // (2) The current unit has an interface dependency on the module unit U.
2014 //
2015 // Here we only check for the first condition. Since we couldn't see
2016 // DeclModule if it isn't (transitively) imported.
2017 if (DeclTopModule->isModuleInterfaceUnit())
2018 return true;
2019
2020 // [module.reach]/p1,2
2021 // A translation unit U is necessarily reachable from a point P if U is a
2022 // module interface unit on which the translation unit containing P has an
2023 // interface dependency, or the translation unit containing P imports U, in
2024 // either case prior to P
2025 //
2026 // Additional translation units on
2027 // which the point within the program has an interface dependency may be
2028 // considered reachable, but it is unspecified which are and under what
2029 // circumstances.
2030 Module *CurrentM = SemaRef.getCurrentModule();
2031
2032 // Directly imported module are necessarily reachable.
2033 // Since we can't export import a module implementation partition unit, we
2034 // don't need to count for Exports here.
2035 if (CurrentM && CurrentM->getTopLevelModule()->Imports.count(key: DeclTopModule))
2036 return true;
2037
2038 // Then we treat all module implementation partition unit as unreachable.
2039 return false;
2040}
2041
2042bool Sema::isAcceptableSlow(const NamedDecl *D, Sema::AcceptableKind Kind) {
2043 return LookupResult::isAcceptable(SemaRef&: *this, D: const_cast<NamedDecl *>(D), Kind);
2044}
2045
2046bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
2047 // FIXME: If there are both visible and hidden declarations, we need to take
2048 // into account whether redeclaration is possible. Example:
2049 //
2050 // Non-imported module:
2051 // int f(T); // #1
2052 // Some TU:
2053 // static int f(U); // #2, not a redeclaration of #1
2054 // int f(T); // #3, finds both, should link with #1 if T != U, but
2055 // // with #2 if T == U; neither should be ambiguous.
2056 for (auto *D : R) {
2057 if (isVisible(D))
2058 return true;
2059 assert(D->isExternallyDeclarable() &&
2060 "should not have hidden, non-externally-declarable result here");
2061 }
2062
2063 // This function is called once "New" is essentially complete, but before a
2064 // previous declaration is attached. We can't query the linkage of "New" in
2065 // general, because attaching the previous declaration can change the
2066 // linkage of New to match the previous declaration.
2067 //
2068 // However, because we've just determined that there is no *visible* prior
2069 // declaration, we can compute the linkage here. There are two possibilities:
2070 //
2071 // * This is not a redeclaration; it's safe to compute the linkage now.
2072 //
2073 // * This is a redeclaration of a prior declaration that is externally
2074 // redeclarable. In that case, the linkage of the declaration is not
2075 // changed by attaching the prior declaration, because both are externally
2076 // declarable (and thus ExternalLinkage or VisibleNoLinkage).
2077 //
2078 // FIXME: This is subtle and fragile.
2079 return New->isExternallyDeclarable();
2080}
2081
2082/// Retrieve the visible declaration corresponding to D, if any.
2083///
2084/// This routine determines whether the declaration D is visible in the current
2085/// module, with the current imports. If not, it checks whether any
2086/// redeclaration of D is visible, and if so, returns that declaration.
2087///
2088/// \returns D, or a visible previous declaration of D, whichever is more recent
2089/// and visible. If no declaration of D is visible, returns null.
2090static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D,
2091 unsigned IDNS) {
2092 assert(!LookupResult::isAvailableForLookup(SemaRef, D) && "not in slow case");
2093
2094 for (auto *RD : D->redecls()) {
2095 // Don't bother with extra checks if we already know this one isn't visible.
2096 if (RD == D)
2097 continue;
2098
2099 auto ND = cast<NamedDecl>(Val: RD);
2100 // FIXME: This is wrong in the case where the previous declaration is not
2101 // visible in the same scope as D. This needs to be done much more
2102 // carefully.
2103 if (ND->isInIdentifierNamespace(NS: IDNS) &&
2104 LookupResult::isAvailableForLookup(SemaRef, ND))
2105 return ND;
2106 }
2107
2108 return nullptr;
2109}
2110
2111bool Sema::hasVisibleDeclarationSlow(const NamedDecl *D,
2112 llvm::SmallVectorImpl<Module *> *Modules) {
2113 assert(!isVisible(D) && "not in slow case");
2114 return hasAcceptableDeclarationImpl(
2115 S&: *this, D, Modules, F: [](const NamedDecl *) { return true; },
2116 Kind: Sema::AcceptableKind::Visible);
2117}
2118
2119bool Sema::hasReachableDeclarationSlow(
2120 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
2121 assert(!isReachable(D) && "not in slow case");
2122 return hasAcceptableDeclarationImpl(
2123 S&: *this, D, Modules, F: [](const NamedDecl *) { return true; },
2124 Kind: Sema::AcceptableKind::Reachable);
2125}
2126
2127NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
2128 if (auto *ND = dyn_cast<NamespaceDecl>(Val: D)) {
2129 // Namespaces are a bit of a special case: we expect there to be a lot of
2130 // redeclarations of some namespaces, all declarations of a namespace are
2131 // essentially interchangeable, all declarations are found by name lookup
2132 // if any is, and namespaces are never looked up during template
2133 // instantiation. So we benefit from caching the check in this case, and
2134 // it is correct to do so.
2135 auto *Key = ND->getCanonicalDecl();
2136 if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Val: Key))
2137 return Acceptable;
2138 auto *Acceptable = isVisible(SemaRef&: getSema(), D: Key)
2139 ? Key
2140 : findAcceptableDecl(SemaRef&: getSema(), D: Key, IDNS);
2141 if (Acceptable)
2142 getSema().VisibleNamespaceCache.insert(KV: std::make_pair(x&: Key, y&: Acceptable));
2143 return Acceptable;
2144 }
2145
2146 return findAcceptableDecl(SemaRef&: getSema(), D, IDNS);
2147}
2148
2149bool LookupResult::isVisible(Sema &SemaRef, NamedDecl *D) {
2150 // If this declaration is already visible, return it directly.
2151 if (D->isUnconditionallyVisible())
2152 return true;
2153
2154 // During template instantiation, we can refer to hidden declarations, if
2155 // they were visible in any module along the path of instantiation.
2156 return isAcceptableSlow(SemaRef, D, Kind: Sema::AcceptableKind::Visible);
2157}
2158
2159bool LookupResult::isReachable(Sema &SemaRef, NamedDecl *D) {
2160 if (D->isUnconditionallyVisible())
2161 return true;
2162
2163 return isAcceptableSlow(SemaRef, D, Kind: Sema::AcceptableKind::Reachable);
2164}
2165
2166bool LookupResult::isAvailableForLookup(Sema &SemaRef, NamedDecl *ND) {
2167 // We should check the visibility at the callsite already.
2168 if (isVisible(SemaRef, D: ND))
2169 return true;
2170
2171 // Deduction guide lives in namespace scope generally, but it is just a
2172 // hint to the compilers. What we actually lookup for is the generated member
2173 // of the corresponding template. So it is sufficient to check the
2174 // reachability of the template decl.
2175 if (auto *DeductionGuide = ND->getDeclName().getCXXDeductionGuideTemplate())
2176 return SemaRef.hasReachableDefinition(D: DeductionGuide);
2177
2178 // FIXME: The lookup for allocation function is a standalone process.
2179 // (We can find the logics in Sema::FindAllocationFunctions)
2180 //
2181 // Such structure makes it a problem when we instantiate a template
2182 // declaration using placement allocation function if the placement
2183 // allocation function is invisible.
2184 // (See https://github.com/llvm/llvm-project/issues/59601)
2185 //
2186 // Here we workaround it by making the placement allocation functions
2187 // always acceptable. The downside is that we can't diagnose the direct
2188 // use of the invisible placement allocation functions. (Although such uses
2189 // should be rare).
2190 if (auto *FD = dyn_cast<FunctionDecl>(Val: ND);
2191 FD && FD->isReservedGlobalPlacementOperator())
2192 return true;
2193
2194 auto *DC = ND->getDeclContext();
2195 // If ND is not visible and it is at namespace scope, it shouldn't be found
2196 // by name lookup.
2197 if (DC->isFileContext())
2198 return false;
2199
2200 // [module.interface]p7
2201 // Class and enumeration member names can be found by name lookup in any
2202 // context in which a definition of the type is reachable.
2203 //
2204 // NOTE: The above wording may be problematic. See
2205 // https://github.com/llvm/llvm-project/issues/131058 But it is much complext
2206 // to adjust it in Sema's lookup process. Now we hacked it in ASTWriter. See
2207 // the comments in ASTDeclContextNameLookupTrait::getLookupVisibility.
2208 if (auto *TD = dyn_cast<TagDecl>(Val: DC))
2209 return SemaRef.hasReachableDefinition(D: TD);
2210
2211 return false;
2212}
2213
2214bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation,
2215 bool ForceNoCPlusPlus) {
2216 DeclarationName Name = R.getLookupName();
2217 if (!Name) return false;
2218
2219 LookupNameKind NameKind = R.getLookupKind();
2220
2221 if (!getLangOpts().CPlusPlus || ForceNoCPlusPlus) {
2222 // Unqualified name lookup in C/Objective-C is purely lexical, so
2223 // search in the declarations attached to the name.
2224 if (NameKind == Sema::LookupRedeclarationWithLinkage) {
2225 // Find the nearest non-transparent declaration scope.
2226 while (!(S->getFlags() & Scope::DeclScope) ||
2227 (S->getEntity() && S->getEntity()->isTransparentContext()))
2228 S = S->getParent();
2229 }
2230
2231 // When performing a scope lookup, we want to find local extern decls.
2232 FindLocalExternScope FindLocals(R);
2233
2234 // Scan up the scope chain looking for a decl that matches this
2235 // identifier that is in the appropriate namespace. This search
2236 // should not take long, as shadowing of names is uncommon, and
2237 // deep shadowing is extremely uncommon.
2238 bool LeftStartingScope = false;
2239
2240 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
2241 IEnd = IdResolver.end();
2242 I != IEnd; ++I)
2243 if (NamedDecl *D = R.getAcceptableDecl(D: *I)) {
2244 if (NameKind == LookupRedeclarationWithLinkage) {
2245 // Determine whether this (or a previous) declaration is
2246 // out-of-scope.
2247 if (!LeftStartingScope && !S->isDeclScope(D: *I))
2248 LeftStartingScope = true;
2249
2250 // If we found something outside of our starting scope that
2251 // does not have linkage, skip it.
2252 if (LeftStartingScope && !((*I)->hasLinkage())) {
2253 R.setShadowed();
2254 continue;
2255 }
2256 }
2257 else if (NameKind == LookupObjCImplicitSelfParam &&
2258 !isa<ImplicitParamDecl>(Val: *I))
2259 continue;
2260
2261 R.addDecl(D);
2262
2263 // Check whether there are any other declarations with the same name
2264 // and in the same scope.
2265 if (I != IEnd) {
2266 // Find the scope in which this declaration was declared (if it
2267 // actually exists in a Scope).
2268 while (S && !S->isDeclScope(D))
2269 S = S->getParent();
2270
2271 // If the scope containing the declaration is the translation unit,
2272 // then we'll need to perform our checks based on the matching
2273 // DeclContexts rather than matching scopes.
2274 if (S && isNamespaceOrTranslationUnitScope(S))
2275 S = nullptr;
2276
2277 // Compute the DeclContext, if we need it.
2278 DeclContext *DC = nullptr;
2279 if (!S)
2280 DC = (*I)->getDeclContext()->getRedeclContext();
2281
2282 IdentifierResolver::iterator LastI = I;
2283 for (++LastI; LastI != IEnd; ++LastI) {
2284 if (S) {
2285 // Match based on scope.
2286 if (!S->isDeclScope(D: *LastI))
2287 break;
2288 } else {
2289 // Match based on DeclContext.
2290 DeclContext *LastDC
2291 = (*LastI)->getDeclContext()->getRedeclContext();
2292 if (!LastDC->Equals(DC))
2293 break;
2294 }
2295
2296 // If the declaration is in the right namespace and visible, add it.
2297 if (NamedDecl *LastD = R.getAcceptableDecl(D: *LastI))
2298 R.addDecl(D: LastD);
2299 }
2300
2301 R.resolveKind();
2302 }
2303
2304 return true;
2305 }
2306 } else {
2307 // Perform C++ unqualified name lookup.
2308 if (CppLookupName(R, S))
2309 return true;
2310 }
2311
2312 // If we didn't find a use of this identifier, and if the identifier
2313 // corresponds to a compiler builtin, create the decl object for the builtin
2314 // now, injecting it into translation unit scope, and return it.
2315 if (AllowBuiltinCreation && LookupBuiltin(R))
2316 return true;
2317
2318 // If we didn't find a use of this identifier, the ExternalSource
2319 // may be able to handle the situation.
2320 // Note: some lookup failures are expected!
2321 // See e.g. R.isForRedeclaration().
2322 return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
2323}
2324
2325/// Perform qualified name lookup in the namespaces nominated by
2326/// using directives by the given context.
2327///
2328/// C++98 [namespace.qual]p2:
2329/// Given X::m (where X is a user-declared namespace), or given \::m
2330/// (where X is the global namespace), let S be the set of all
2331/// declarations of m in X and in the transitive closure of all
2332/// namespaces nominated by using-directives in X and its used
2333/// namespaces, except that using-directives are ignored in any
2334/// namespace, including X, directly containing one or more
2335/// declarations of m. No namespace is searched more than once in
2336/// the lookup of a name. If S is the empty set, the program is
2337/// ill-formed. Otherwise, if S has exactly one member, or if the
2338/// context of the reference is a using-declaration
2339/// (namespace.udecl), S is the required set of declarations of
2340/// m. Otherwise if the use of m is not one that allows a unique
2341/// declaration to be chosen from S, the program is ill-formed.
2342///
2343/// C++98 [namespace.qual]p5:
2344/// During the lookup of a qualified namespace member name, if the
2345/// lookup finds more than one declaration of the member, and if one
2346/// declaration introduces a class name or enumeration name and the
2347/// other declarations either introduce the same object, the same
2348/// enumerator or a set of functions, the non-type name hides the
2349/// class or enumeration name if and only if the declarations are
2350/// from the same namespace; otherwise (the declarations are from
2351/// different namespaces), the program is ill-formed.
2352static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
2353 DeclContext *StartDC) {
2354 assert(StartDC->isFileContext() && "start context is not a file context");
2355
2356 // We have not yet looked into these namespaces, much less added
2357 // their "using-children" to the queue.
2358 SmallVector<NamespaceDecl*, 8> Queue;
2359
2360 // We have at least added all these contexts to the queue.
2361 llvm::SmallPtrSet<DeclContext*, 8> Visited;
2362 Visited.insert(Ptr: StartDC);
2363
2364 // We have already looked into the initial namespace; seed the queue
2365 // with its using-children.
2366 for (auto *I : StartDC->using_directives()) {
2367 NamespaceDecl *ND = I->getNominatedNamespace()->getFirstDecl();
2368 if (S.isVisible(D: I) && Visited.insert(Ptr: ND).second)
2369 Queue.push_back(Elt: ND);
2370 }
2371
2372 // The easiest way to implement the restriction in [namespace.qual]p5
2373 // is to check whether any of the individual results found a tag
2374 // and, if so, to declare an ambiguity if the final result is not
2375 // a tag.
2376 bool FoundTag = false;
2377 bool FoundNonTag = false;
2378
2379 LookupResult LocalR(LookupResult::Temporary, R);
2380
2381 bool Found = false;
2382 while (!Queue.empty()) {
2383 NamespaceDecl *ND = Queue.pop_back_val();
2384
2385 // We go through some convolutions here to avoid copying results
2386 // between LookupResults.
2387 bool UseLocal = !R.empty();
2388 LookupResult &DirectR = UseLocal ? LocalR : R;
2389 bool FoundDirect = LookupDirect(S, R&: DirectR, DC: ND);
2390
2391 if (FoundDirect) {
2392 // First do any local hiding.
2393 DirectR.resolveKind();
2394
2395 // If the local result is a tag, remember that.
2396 if (DirectR.isSingleTagDecl())
2397 FoundTag = true;
2398 else
2399 FoundNonTag = true;
2400
2401 // Append the local results to the total results if necessary.
2402 if (UseLocal) {
2403 R.addAllDecls(Other: LocalR);
2404 LocalR.clear();
2405 }
2406 }
2407
2408 // If we find names in this namespace, ignore its using directives.
2409 if (FoundDirect) {
2410 Found = true;
2411 continue;
2412 }
2413
2414 for (auto *I : ND->using_directives()) {
2415 NamespaceDecl *Nom = I->getNominatedNamespace();
2416 if (S.isVisible(D: I) && Visited.insert(Ptr: Nom).second)
2417 Queue.push_back(Elt: Nom);
2418 }
2419 }
2420
2421 if (Found) {
2422 if (FoundTag && FoundNonTag)
2423 R.setAmbiguousQualifiedTagHiding();
2424 else
2425 R.resolveKind();
2426 }
2427
2428 return Found;
2429}
2430
2431bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2432 bool InUnqualifiedLookup) {
2433 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
2434
2435 if (!R.getLookupName())
2436 return false;
2437
2438#ifndef NDEBUG
2439 // Make sure that the declaration context is complete.
2440 if (const auto *TD = dyn_cast<TagDecl>(LookupCtx);
2441 TD && !TD->isDependentType() && TD->getDefinition() == nullptr)
2442 llvm_unreachable("Declaration context must already be complete!");
2443#endif
2444
2445 struct QualifiedLookupInScope {
2446 bool oldVal;
2447 DeclContext *Context;
2448 // Set flag in DeclContext informing debugger that we're looking for qualified name
2449 QualifiedLookupInScope(DeclContext *ctx)
2450 : oldVal(ctx->shouldUseQualifiedLookup()), Context(ctx) {
2451 ctx->setUseQualifiedLookup();
2452 }
2453 ~QualifiedLookupInScope() {
2454 Context->setUseQualifiedLookup(oldVal);
2455 }
2456 } QL(LookupCtx);
2457
2458 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(Val: LookupCtx);
2459 // FIXME: Per [temp.dep.general]p2, an unqualified name is also dependent
2460 // if it's a dependent conversion-function-id or operator= where the current
2461 // class is a templated entity. This should be handled in LookupName.
2462 if (!InUnqualifiedLookup && !R.isForRedeclaration()) {
2463 // C++23 [temp.dep.type]p5:
2464 // A qualified name is dependent if
2465 // - it is a conversion-function-id whose conversion-type-id
2466 // is dependent, or
2467 // - [...]
2468 // - its lookup context is the current instantiation and it
2469 // is operator=, or
2470 // - [...]
2471 if (DeclarationName Name = R.getLookupName();
2472 Name.getNameKind() == DeclarationName::CXXConversionFunctionName &&
2473 Name.getCXXNameType()->isDependentType()) {
2474 R.setNotFoundInCurrentInstantiation();
2475 return false;
2476 }
2477 }
2478
2479 if (LookupDirect(S&: *this, R, DC: LookupCtx)) {
2480 R.resolveKind();
2481 if (LookupRec)
2482 R.setNamingClass(LookupRec);
2483 return true;
2484 }
2485
2486 // Don't descend into implied contexts for redeclarations.
2487 // C++98 [namespace.qual]p6:
2488 // In a declaration for a namespace member in which the
2489 // declarator-id is a qualified-id, given that the qualified-id
2490 // for the namespace member has the form
2491 // nested-name-specifier unqualified-id
2492 // the unqualified-id shall name a member of the namespace
2493 // designated by the nested-name-specifier.
2494 // See also [class.mfct]p5 and [class.static.data]p2.
2495 if (R.isForRedeclaration())
2496 return false;
2497
2498 // If this is a namespace, look it up in the implied namespaces.
2499 if (LookupCtx->isFileContext())
2500 return LookupQualifiedNameInUsingDirectives(S&: *this, R, StartDC: LookupCtx);
2501
2502 // If this isn't a C++ class, we aren't allowed to look into base
2503 // classes, we're done.
2504 if (!LookupRec || !LookupRec->getDefinition())
2505 return false;
2506
2507 // We're done for lookups that can never succeed for C++ classes.
2508 if (R.getLookupKind() == LookupOperatorName ||
2509 R.getLookupKind() == LookupNamespaceName ||
2510 R.getLookupKind() == LookupObjCProtocolName ||
2511 R.getLookupKind() == LookupLabel)
2512 return false;
2513
2514 // If we're performing qualified name lookup into a dependent class,
2515 // then we are actually looking into a current instantiation. If we have any
2516 // dependent base classes, then we either have to delay lookup until
2517 // template instantiation time (at which point all bases will be available)
2518 // or we have to fail.
2519 if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
2520 LookupRec->hasAnyDependentBases()) {
2521 R.setNotFoundInCurrentInstantiation();
2522 return false;
2523 }
2524
2525 // Perform lookup into our base classes.
2526
2527 DeclarationName Name = R.getLookupName();
2528 unsigned IDNS = R.getIdentifierNamespace();
2529
2530 // Look for this member in our base classes.
2531 auto BaseCallback = [Name, IDNS](const CXXBaseSpecifier *Specifier,
2532 CXXBasePath &Path) -> bool {
2533 CXXRecordDecl *BaseRecord = Specifier->getType()->getAsCXXRecordDecl();
2534 // Drop leading non-matching lookup results from the declaration list so
2535 // we don't need to consider them again below.
2536 for (Path.Decls = BaseRecord->lookup(Name).begin();
2537 Path.Decls != Path.Decls.end(); ++Path.Decls) {
2538 if ((*Path.Decls)->isInIdentifierNamespace(NS: IDNS))
2539 return true;
2540 }
2541 return false;
2542 };
2543
2544 CXXBasePaths Paths;
2545 Paths.setOrigin(LookupRec);
2546 if (!LookupRec->lookupInBases(BaseMatches: BaseCallback, Paths))
2547 return false;
2548
2549 R.setNamingClass(LookupRec);
2550
2551 // C++ [class.member.lookup]p2:
2552 // [...] If the resulting set of declarations are not all from
2553 // sub-objects of the same type, or the set has a nonstatic member
2554 // and includes members from distinct sub-objects, there is an
2555 // ambiguity and the program is ill-formed. Otherwise that set is
2556 // the result of the lookup.
2557 QualType SubobjectType;
2558 int SubobjectNumber = 0;
2559 AccessSpecifier SubobjectAccess = AS_none;
2560
2561 // Check whether the given lookup result contains only static members.
2562 auto HasOnlyStaticMembers = [&](DeclContext::lookup_iterator Result) {
2563 for (DeclContext::lookup_iterator I = Result, E = I.end(); I != E; ++I)
2564 if ((*I)->isInIdentifierNamespace(NS: IDNS) && (*I)->isCXXInstanceMember())
2565 return false;
2566 return true;
2567 };
2568
2569 bool TemplateNameLookup = R.isTemplateNameLookup();
2570
2571 // Determine whether two sets of members contain the same members, as
2572 // required by C++ [class.member.lookup]p6.
2573 auto HasSameDeclarations = [&](DeclContext::lookup_iterator A,
2574 DeclContext::lookup_iterator B) {
2575 using Iterator = DeclContextLookupResult::iterator;
2576 using Result = const void *;
2577
2578 auto Next = [&](Iterator &It, Iterator End) -> Result {
2579 while (It != End) {
2580 NamedDecl *ND = *It++;
2581 if (!ND->isInIdentifierNamespace(NS: IDNS))
2582 continue;
2583
2584 // C++ [temp.local]p3:
2585 // A lookup that finds an injected-class-name (10.2) can result in
2586 // an ambiguity in certain cases (for example, if it is found in
2587 // more than one base class). If all of the injected-class-names
2588 // that are found refer to specializations of the same class
2589 // template, and if the name is used as a template-name, the
2590 // reference refers to the class template itself and not a
2591 // specialization thereof, and is not ambiguous.
2592 if (TemplateNameLookup)
2593 if (auto *TD = getAsTemplateNameDecl(D: ND))
2594 ND = TD;
2595
2596 // C++ [class.member.lookup]p3:
2597 // type declarations (including injected-class-names) are replaced by
2598 // the types they designate
2599 if (const TypeDecl *TD = dyn_cast<TypeDecl>(Val: ND->getUnderlyingDecl()))
2600 return Context.getCanonicalTypeDeclType(TD).getAsOpaquePtr();
2601
2602 return ND->getUnderlyingDecl()->getCanonicalDecl();
2603 }
2604 return nullptr;
2605 };
2606
2607 // We'll often find the declarations are in the same order. Handle this
2608 // case (and the special case of only one declaration) efficiently.
2609 Iterator AIt = A, BIt = B, AEnd, BEnd;
2610 while (true) {
2611 Result AResult = Next(AIt, AEnd);
2612 Result BResult = Next(BIt, BEnd);
2613 if (!AResult && !BResult)
2614 return true;
2615 if (!AResult || !BResult)
2616 return false;
2617 if (AResult != BResult) {
2618 // Found a mismatch; carefully check both lists, accounting for the
2619 // possibility of declarations appearing more than once.
2620 llvm::SmallDenseMap<Result, bool, 32> AResults;
2621 for (; AResult; AResult = Next(AIt, AEnd))
2622 AResults.insert(KV: {AResult, /*FoundInB*/false});
2623 unsigned Found = 0;
2624 for (; BResult; BResult = Next(BIt, BEnd)) {
2625 auto It = AResults.find(Val: BResult);
2626 if (It == AResults.end())
2627 return false;
2628 if (!It->second) {
2629 It->second = true;
2630 ++Found;
2631 }
2632 }
2633 return AResults.size() == Found;
2634 }
2635 }
2636 };
2637
2638 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
2639 Path != PathEnd; ++Path) {
2640 const CXXBasePathElement &PathElement = Path->back();
2641
2642 // Pick the best (i.e. most permissive i.e. numerically lowest) access
2643 // across all paths.
2644 SubobjectAccess = std::min(a: SubobjectAccess, b: Path->Access);
2645
2646 // Determine whether we're looking at a distinct sub-object or not.
2647 if (SubobjectType.isNull()) {
2648 // This is the first subobject we've looked at. Record its type.
2649 SubobjectType = Context.getCanonicalType(T: PathElement.Base->getType());
2650 SubobjectNumber = PathElement.SubobjectNumber;
2651 continue;
2652 }
2653
2654 if (SubobjectType !=
2655 Context.getCanonicalType(T: PathElement.Base->getType())) {
2656 // We found members of the given name in two subobjects of
2657 // different types. If the declaration sets aren't the same, this
2658 // lookup is ambiguous.
2659 //
2660 // FIXME: The language rule says that this applies irrespective of
2661 // whether the sets contain only static members.
2662 if (HasOnlyStaticMembers(Path->Decls) &&
2663 HasSameDeclarations(Paths.begin()->Decls, Path->Decls))
2664 continue;
2665
2666 R.setAmbiguousBaseSubobjectTypes(Paths);
2667 return true;
2668 }
2669
2670 // FIXME: This language rule no longer exists. Checking for ambiguous base
2671 // subobjects should be done as part of formation of a class member access
2672 // expression (when converting the object parameter to the member's type).
2673 if (SubobjectNumber != PathElement.SubobjectNumber) {
2674 // We have a different subobject of the same type.
2675
2676 // C++ [class.member.lookup]p5:
2677 // A static member, a nested type or an enumerator defined in
2678 // a base class T can unambiguously be found even if an object
2679 // has more than one base class subobject of type T.
2680 if (HasOnlyStaticMembers(Path->Decls))
2681 continue;
2682
2683 // We have found a nonstatic member name in multiple, distinct
2684 // subobjects. Name lookup is ambiguous.
2685 R.setAmbiguousBaseSubobjects(Paths);
2686 return true;
2687 }
2688 }
2689
2690 // Lookup in a base class succeeded; return these results.
2691
2692 for (DeclContext::lookup_iterator I = Paths.front().Decls, E = I.end();
2693 I != E; ++I) {
2694 AccessSpecifier AS = CXXRecordDecl::MergeAccess(PathAccess: SubobjectAccess,
2695 DeclAccess: (*I)->getAccess());
2696 if (NamedDecl *ND = R.getAcceptableDecl(D: *I))
2697 R.addDecl(D: ND, AS);
2698 }
2699 R.resolveKind();
2700 return true;
2701}
2702
2703bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2704 CXXScopeSpec &SS) {
2705 NestedNameSpecifier Qualifier = SS.getScopeRep();
2706 if (Qualifier.getKind() == NestedNameSpecifier::Kind::MicrosoftSuper)
2707 return LookupInSuper(R, Class: Qualifier.getAsMicrosoftSuper());
2708 return LookupQualifiedName(R, LookupCtx);
2709}
2710
2711bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
2712 QualType ObjectType, bool AllowBuiltinCreation,
2713 bool EnteringContext) {
2714 // When the scope specifier is invalid, don't even look for anything.
2715 if (SS && SS->isInvalid())
2716 return false;
2717
2718 // Determine where to perform name lookup
2719 DeclContext *DC = nullptr;
2720 bool IsDependent = false;
2721 if (!ObjectType.isNull()) {
2722 // This nested-name-specifier occurs in a member access expression, e.g.,
2723 // x->B::f, and we are looking into the type of the object.
2724 assert((!SS || SS->isEmpty()) &&
2725 "ObjectType and scope specifier cannot coexist");
2726 DC = computeDeclContext(T: ObjectType);
2727 IsDependent = !DC && ObjectType->isDependentType();
2728 assert(((!DC && ObjectType->isDependentType()) ||
2729 !ObjectType->isIncompleteType() || !ObjectType->getAs<TagType>() ||
2730 ObjectType->castAs<TagType>()->getDecl()->isEntityBeingDefined()) &&
2731 "Caller should have completed object type");
2732 } else if (SS && SS->isNotEmpty()) {
2733 // This nested-name-specifier occurs after another nested-name-specifier,
2734 // so long into the context associated with the prior nested-name-specifier.
2735 if ((DC = computeDeclContext(SS: *SS, EnteringContext))) {
2736 // The declaration context must be complete.
2737 if (!DC->isDependentContext() && RequireCompleteDeclContext(SS&: *SS, DC))
2738 return false;
2739 R.setContextRange(SS->getRange());
2740 // FIXME: '__super' lookup semantics could be implemented by a
2741 // LookupResult::isSuperLookup flag which skips the initial search of
2742 // the lookup context in LookupQualified.
2743 if (NestedNameSpecifier Qualifier = SS->getScopeRep();
2744 Qualifier.getKind() == NestedNameSpecifier::Kind::MicrosoftSuper)
2745 return LookupInSuper(R, Class: Qualifier.getAsMicrosoftSuper());
2746 }
2747 IsDependent = !DC && isDependentScopeSpecifier(SS: *SS);
2748 } else {
2749 // Perform unqualified name lookup starting in the given scope.
2750 return LookupName(R, S, AllowBuiltinCreation);
2751 }
2752
2753 // If we were able to compute a declaration context, perform qualified name
2754 // lookup in that context.
2755 if (DC)
2756 return LookupQualifiedName(R, LookupCtx: DC);
2757 else if (IsDependent)
2758 // We could not resolve the scope specified to a specific declaration
2759 // context, which means that SS refers to an unknown specialization.
2760 // Name lookup can't find anything in this case.
2761 R.setNotFoundInCurrentInstantiation();
2762 return false;
2763}
2764
2765bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) {
2766 // The access-control rules we use here are essentially the rules for
2767 // doing a lookup in Class that just magically skipped the direct
2768 // members of Class itself. That is, the naming class is Class, and the
2769 // access includes the access of the base.
2770 for (const auto &BaseSpec : Class->bases()) {
2771 auto *RD = BaseSpec.getType()->castAsCXXRecordDecl();
2772 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
2773 Result.setBaseObjectType(Context.getCanonicalTagType(TD: Class));
2774 LookupQualifiedName(R&: Result, LookupCtx: RD);
2775
2776 // Copy the lookup results into the target, merging the base's access into
2777 // the path access.
2778 for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
2779 R.addDecl(D: I.getDecl(),
2780 AS: CXXRecordDecl::MergeAccess(PathAccess: BaseSpec.getAccessSpecifier(),
2781 DeclAccess: I.getAccess()));
2782 }
2783
2784 Result.suppressDiagnostics();
2785 }
2786
2787 R.resolveKind();
2788 R.setNamingClass(Class);
2789
2790 return !R.empty();
2791}
2792
2793void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
2794 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
2795
2796 DeclarationName Name = Result.getLookupName();
2797 SourceLocation NameLoc = Result.getNameLoc();
2798 SourceRange LookupRange = Result.getContextRange();
2799
2800 switch (Result.getAmbiguityKind()) {
2801 case LookupAmbiguityKind::AmbiguousBaseSubobjects: {
2802 CXXBasePaths *Paths = Result.getBasePaths();
2803 QualType SubobjectType = Paths->front().back().Base->getType();
2804 Diag(Loc: NameLoc, DiagID: diag::err_ambiguous_member_multiple_subobjects)
2805 << Name << SubobjectType << getAmbiguousPathsDisplayString(Paths&: *Paths)
2806 << LookupRange;
2807
2808 DeclContext::lookup_iterator Found = Paths->front().Decls;
2809 while (isa<CXXMethodDecl>(Val: *Found) &&
2810 cast<CXXMethodDecl>(Val: *Found)->isStatic())
2811 ++Found;
2812
2813 Diag(Loc: (*Found)->getLocation(), DiagID: diag::note_ambiguous_member_found);
2814 break;
2815 }
2816
2817 case LookupAmbiguityKind::AmbiguousBaseSubobjectTypes: {
2818 Diag(Loc: NameLoc, DiagID: diag::err_ambiguous_member_multiple_subobject_types)
2819 << Name << LookupRange;
2820
2821 CXXBasePaths *Paths = Result.getBasePaths();
2822 std::set<const NamedDecl *> DeclsPrinted;
2823 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
2824 PathEnd = Paths->end();
2825 Path != PathEnd; ++Path) {
2826 const NamedDecl *D = *Path->Decls;
2827 if (!D->isInIdentifierNamespace(NS: Result.getIdentifierNamespace()))
2828 continue;
2829 if (DeclsPrinted.insert(x: D).second) {
2830 if (const auto *TD = dyn_cast<TypedefNameDecl>(Val: D->getUnderlyingDecl()))
2831 Diag(Loc: D->getLocation(), DiagID: diag::note_ambiguous_member_type_found)
2832 << TD->getUnderlyingType();
2833 else if (const auto *TD = dyn_cast<TypeDecl>(Val: D->getUnderlyingDecl()))
2834 Diag(Loc: D->getLocation(), DiagID: diag::note_ambiguous_member_type_found)
2835 << Context.getTypeDeclType(Decl: TD);
2836 else
2837 Diag(Loc: D->getLocation(), DiagID: diag::note_ambiguous_member_found);
2838 }
2839 }
2840 break;
2841 }
2842
2843 case LookupAmbiguityKind::AmbiguousTagHiding: {
2844 Diag(Loc: NameLoc, DiagID: diag::err_ambiguous_tag_hiding) << Name << LookupRange;
2845
2846 llvm::SmallPtrSet<NamedDecl*, 8> TagDecls;
2847
2848 for (auto *D : Result)
2849 if (TagDecl *TD = dyn_cast<TagDecl>(Val: D)) {
2850 TagDecls.insert(Ptr: TD);
2851 Diag(Loc: TD->getLocation(), DiagID: diag::note_hidden_tag);
2852 }
2853
2854 for (auto *D : Result)
2855 if (!isa<TagDecl>(Val: D))
2856 Diag(Loc: D->getLocation(), DiagID: diag::note_hiding_object);
2857
2858 // For recovery purposes, go ahead and implement the hiding.
2859 LookupResult::Filter F = Result.makeFilter();
2860 while (F.hasNext()) {
2861 if (TagDecls.count(Ptr: F.next()))
2862 F.erase();
2863 }
2864 F.done();
2865 break;
2866 }
2867
2868 case LookupAmbiguityKind::AmbiguousReferenceToPlaceholderVariable: {
2869 Diag(Loc: NameLoc, DiagID: diag::err_using_placeholder_variable) << Name << LookupRange;
2870 DeclContext *DC = nullptr;
2871 for (auto *D : Result) {
2872 Diag(Loc: D->getLocation(), DiagID: diag::note_reference_placeholder) << D;
2873 if (DC != nullptr && DC != D->getDeclContext())
2874 break;
2875 DC = D->getDeclContext();
2876 }
2877 break;
2878 }
2879
2880 case LookupAmbiguityKind::AmbiguousReference: {
2881 Diag(Loc: NameLoc, DiagID: diag::err_ambiguous_reference) << Name << LookupRange;
2882
2883 for (auto *D : Result)
2884 Diag(Loc: D->getLocation(), DiagID: diag::note_ambiguous_candidate) << D;
2885 break;
2886 }
2887 }
2888}
2889
2890namespace {
2891 struct AssociatedLookup {
2892 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
2893 Sema::AssociatedNamespaceSet &Namespaces,
2894 Sema::AssociatedClassSet &Classes)
2895 : S(S), Namespaces(Namespaces), Classes(Classes),
2896 InstantiationLoc(InstantiationLoc) {
2897 }
2898
2899 bool addClassTransitive(CXXRecordDecl *RD) {
2900 Classes.insert(X: RD);
2901 return ClassesTransitive.insert(X: RD);
2902 }
2903
2904 Sema &S;
2905 Sema::AssociatedNamespaceSet &Namespaces;
2906 Sema::AssociatedClassSet &Classes;
2907 SourceLocation InstantiationLoc;
2908
2909 private:
2910 Sema::AssociatedClassSet ClassesTransitive;
2911 };
2912} // end anonymous namespace
2913
2914static void
2915addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
2916
2917// Given the declaration context \param Ctx of a class, class template or
2918// enumeration, add the associated namespaces to \param Namespaces as described
2919// in [basic.lookup.argdep]p2.
2920static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces,
2921 DeclContext *Ctx) {
2922 // The exact wording has been changed in C++14 as a result of
2923 // CWG 1691 (see also CWG 1690 and CWG 1692). We apply it unconditionally
2924 // to all language versions since it is possible to return a local type
2925 // from a lambda in C++11.
2926 //
2927 // C++14 [basic.lookup.argdep]p2:
2928 // If T is a class type [...]. Its associated namespaces are the innermost
2929 // enclosing namespaces of its associated classes. [...]
2930 //
2931 // If T is an enumeration type, its associated namespace is the innermost
2932 // enclosing namespace of its declaration. [...]
2933
2934 // We additionally skip inline namespaces. The innermost non-inline namespace
2935 // contains all names of all its nested inline namespaces anyway, so we can
2936 // replace the entire inline namespace tree with its root.
2937 while (!Ctx->isFileContext() || Ctx->isInlineNamespace())
2938 Ctx = Ctx->getParent();
2939
2940 // Actually it is fine to always do `Namespaces.insert(Ctx);` simply. But it
2941 // may cause more allocations in Namespaces and more unnecessary lookups. So
2942 // we'd like to insert the representative namespace only.
2943 DeclContext *PrimaryCtx = Ctx->getPrimaryContext();
2944 Decl *PrimaryD = cast<Decl>(Val: PrimaryCtx);
2945 Decl *D = cast<Decl>(Val: Ctx);
2946 ASTContext &AST = D->getASTContext();
2947
2948 // TODO: Technically it is better to insert one namespace per module. e.g.,
2949 //
2950 // ```
2951 // //--- first.cppm
2952 // export module first;
2953 // namespace ns { ... } // first namespace
2954 //
2955 // //--- m-partA.cppm
2956 // export module m:partA;
2957 // import first;
2958 //
2959 // namespace ns { ... }
2960 // namespace ns { ... }
2961 //
2962 // //--- m-partB.cppm
2963 // export module m:partB;
2964 // import first;
2965 // import :partA;
2966 //
2967 // namespace ns { ... }
2968 // namespace ns { ... }
2969 //
2970 // ...
2971 //
2972 // //--- m-partN.cppm
2973 // export module m:partN;
2974 // import first;
2975 // import :partA;
2976 // ...
2977 // import :part$(N-1);
2978 //
2979 // namespace ns { ... }
2980 // namespace ns { ... }
2981 //
2982 // consume(ns::any_decl); // the lookup
2983 // ```
2984 //
2985 // We should only insert once for all namespaces in module m.
2986 if (D->isInNamedModule() &&
2987 !AST.isInSameModule(M1: D->getOwningModule(), M2: PrimaryD->getOwningModule()))
2988 Namespaces.insert(X: Ctx);
2989 else
2990 Namespaces.insert(X: PrimaryCtx);
2991}
2992
2993// Add the associated classes and namespaces for argument-dependent
2994// lookup that involves a template argument (C++ [basic.lookup.argdep]p2).
2995static void
2996addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2997 const TemplateArgument &Arg) {
2998 // C++ [basic.lookup.argdep]p2, last bullet:
2999 // -- [...] ;
3000 switch (Arg.getKind()) {
3001 case TemplateArgument::Null:
3002 break;
3003
3004 case TemplateArgument::Type:
3005 // [...] the namespaces and classes associated with the types of the
3006 // template arguments provided for template type parameters (excluding
3007 // template template parameters)
3008 addAssociatedClassesAndNamespaces(Result, T: Arg.getAsType());
3009 break;
3010
3011 case TemplateArgument::Template:
3012 case TemplateArgument::TemplateExpansion: {
3013 // [...] the namespaces in which any template template arguments are
3014 // defined; and the classes in which any member templates used as
3015 // template template arguments are defined.
3016 TemplateName Template = Arg.getAsTemplateOrTemplatePattern();
3017 if (ClassTemplateDecl *ClassTemplate
3018 = dyn_cast<ClassTemplateDecl>(Val: Template.getAsTemplateDecl())) {
3019 DeclContext *Ctx = ClassTemplate->getDeclContext();
3020 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Val: Ctx))
3021 Result.Classes.insert(X: EnclosingClass);
3022 // Add the associated namespace for this class.
3023 CollectEnclosingNamespace(Namespaces&: Result.Namespaces, Ctx);
3024 }
3025 break;
3026 }
3027
3028 case TemplateArgument::Declaration:
3029 case TemplateArgument::Integral:
3030 case TemplateArgument::Expression:
3031 case TemplateArgument::NullPtr:
3032 case TemplateArgument::StructuralValue:
3033 // [Note: non-type template arguments do not contribute to the set of
3034 // associated namespaces. ]
3035 break;
3036
3037 case TemplateArgument::Pack:
3038 for (const auto &P : Arg.pack_elements())
3039 addAssociatedClassesAndNamespaces(Result, Arg: P);
3040 break;
3041 }
3042}
3043
3044// Add the associated classes and namespaces for argument-dependent lookup
3045// with an argument of class type (C++ [basic.lookup.argdep]p2).
3046static void
3047addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
3048 CXXRecordDecl *Class) {
3049
3050 // Just silently ignore anything whose name is __va_list_tag.
3051 if (Class->getDeclName() == Result.S.VAListTagName)
3052 return;
3053
3054 // C++ [basic.lookup.argdep]p2:
3055 // [...]
3056 // -- If T is a class type (including unions), its associated
3057 // classes are: the class itself; the class of which it is a
3058 // member, if any; and its direct and indirect base classes.
3059 // Its associated namespaces are the innermost enclosing
3060 // namespaces of its associated classes.
3061
3062 // Add the class of which it is a member, if any.
3063 DeclContext *Ctx = Class->getDeclContext();
3064 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Val: Ctx))
3065 Result.Classes.insert(X: EnclosingClass);
3066
3067 // Add the associated namespace for this class.
3068 CollectEnclosingNamespace(Namespaces&: Result.Namespaces, Ctx);
3069
3070 // -- If T is a template-id, its associated namespaces and classes are
3071 // the namespace in which the template is defined; for member
3072 // templates, the member template's class; the namespaces and classes
3073 // associated with the types of the template arguments provided for
3074 // template type parameters (excluding template template parameters); the
3075 // namespaces in which any template template arguments are defined; and
3076 // the classes in which any member templates used as template template
3077 // arguments are defined. [Note: non-type template arguments do not
3078 // contribute to the set of associated namespaces. ]
3079 if (ClassTemplateSpecializationDecl *Spec
3080 = dyn_cast<ClassTemplateSpecializationDecl>(Val: Class)) {
3081 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
3082 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Val: Ctx))
3083 Result.Classes.insert(X: EnclosingClass);
3084 // Add the associated namespace for this class.
3085 CollectEnclosingNamespace(Namespaces&: Result.Namespaces, Ctx);
3086
3087 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
3088 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
3089 addAssociatedClassesAndNamespaces(Result, Arg: TemplateArgs[I]);
3090 }
3091
3092 // Add the class itself. If we've already transitively visited this class,
3093 // we don't need to visit base classes.
3094 if (!Result.addClassTransitive(RD: Class))
3095 return;
3096
3097 // Only recurse into base classes for complete types.
3098 if (!Result.S.isCompleteType(Loc: Result.InstantiationLoc,
3099 T: Result.S.Context.getCanonicalTagType(TD: Class)))
3100 return;
3101
3102 // Add direct and indirect base classes along with their associated
3103 // namespaces.
3104 SmallVector<CXXRecordDecl *, 32> Bases;
3105 Bases.push_back(Elt: Class);
3106 while (!Bases.empty()) {
3107 // Pop this class off the stack.
3108 Class = Bases.pop_back_val();
3109
3110 // Visit the base classes.
3111 for (const auto &Base : Class->bases()) {
3112 CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
3113 // In dependent contexts, we do ADL twice, and the first time around,
3114 // the base type might be a dependent TemplateSpecializationType, or a
3115 // TemplateTypeParmType. If that happens, simply ignore it.
3116 // FIXME: If we want to support export, we probably need to add the
3117 // namespace of the template in a TemplateSpecializationType, or even
3118 // the classes and namespaces of known non-dependent arguments.
3119 if (!BaseDecl)
3120 continue;
3121 if (Result.addClassTransitive(RD: BaseDecl)) {
3122 // Find the associated namespace for this base class.
3123 DeclContext *BaseCtx = BaseDecl->getDeclContext();
3124 CollectEnclosingNamespace(Namespaces&: Result.Namespaces, Ctx: BaseCtx);
3125
3126 // Make sure we visit the bases of this base class.
3127 if (!BaseDecl->bases().empty())
3128 Bases.push_back(Elt: BaseDecl);
3129 }
3130 }
3131 }
3132}
3133
3134// Add the associated classes and namespaces for
3135// argument-dependent lookup with an argument of type T
3136// (C++ [basic.lookup.koenig]p2).
3137static void
3138addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
3139 // C++ [basic.lookup.koenig]p2:
3140 //
3141 // For each argument type T in the function call, there is a set
3142 // of zero or more associated namespaces and a set of zero or more
3143 // associated classes to be considered. The sets of namespaces and
3144 // classes is determined entirely by the types of the function
3145 // arguments (and the namespace of any template template
3146 // argument). Typedef names and using-declarations used to specify
3147 // the types do not contribute to this set. The sets of namespaces
3148 // and classes are determined in the following way:
3149
3150 SmallVector<const Type *, 16> Queue;
3151 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
3152
3153 while (true) {
3154 switch (T->getTypeClass()) {
3155
3156#define TYPE(Class, Base)
3157#define DEPENDENT_TYPE(Class, Base) case Type::Class:
3158#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
3159#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
3160#define ABSTRACT_TYPE(Class, Base)
3161#include "clang/AST/TypeNodes.inc"
3162 // T is canonical. We can also ignore dependent types because
3163 // we don't need to do ADL at the definition point, but if we
3164 // wanted to implement template export (or if we find some other
3165 // use for associated classes and namespaces...) this would be
3166 // wrong.
3167 break;
3168
3169 // -- If T is a pointer to U or an array of U, its associated
3170 // namespaces and classes are those associated with U.
3171 case Type::Pointer:
3172 T = cast<PointerType>(Val: T)->getPointeeType().getTypePtr();
3173 continue;
3174 case Type::ConstantArray:
3175 case Type::IncompleteArray:
3176 case Type::VariableArray:
3177 T = cast<ArrayType>(Val: T)->getElementType().getTypePtr();
3178 continue;
3179
3180 // -- If T is a fundamental type, its associated sets of
3181 // namespaces and classes are both empty.
3182 case Type::Builtin:
3183 break;
3184
3185 // -- If T is a class type (including unions), its associated
3186 // classes are: the class itself; the class of which it is
3187 // a member, if any; and its direct and indirect base classes.
3188 // Its associated namespaces are the innermost enclosing
3189 // namespaces of its associated classes.
3190 case Type::Record: {
3191 // FIXME: This should use the original decl.
3192 auto *Class = cast<CXXRecordDecl>(Val: cast<RecordType>(Val: T)->getDecl())
3193 ->getDefinitionOrSelf();
3194 addAssociatedClassesAndNamespaces(Result, Class);
3195 break;
3196 }
3197
3198 // -- If T is an enumeration type, its associated namespace
3199 // is the innermost enclosing namespace of its declaration.
3200 // If it is a class member, its associated class is the
3201 // member’s class; else it has no associated class.
3202 case Type::Enum: {
3203 // FIXME: This should use the original decl.
3204 auto *Enum = T->castAsEnumDecl();
3205
3206 DeclContext *Ctx = Enum->getDeclContext();
3207 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Val: Ctx))
3208 Result.Classes.insert(X: EnclosingClass);
3209
3210 // Add the associated namespace for this enumeration.
3211 CollectEnclosingNamespace(Namespaces&: Result.Namespaces, Ctx);
3212
3213 break;
3214 }
3215
3216 // -- If T is a function type, its associated namespaces and
3217 // classes are those associated with the function parameter
3218 // types and those associated with the return type.
3219 case Type::FunctionProto: {
3220 const FunctionProtoType *Proto = cast<FunctionProtoType>(Val: T);
3221 for (const auto &Arg : Proto->param_types())
3222 Queue.push_back(Elt: Arg.getTypePtr());
3223 // fallthrough
3224 [[fallthrough]];
3225 }
3226 case Type::FunctionNoProto: {
3227 const FunctionType *FnType = cast<FunctionType>(Val: T);
3228 T = FnType->getReturnType().getTypePtr();
3229 continue;
3230 }
3231
3232 // -- If T is a pointer to a member function of a class X, its
3233 // associated namespaces and classes are those associated
3234 // with the function parameter types and return type,
3235 // together with those associated with X.
3236 //
3237 // -- If T is a pointer to a data member of class X, its
3238 // associated namespaces and classes are those associated
3239 // with the member type together with those associated with
3240 // X.
3241 case Type::MemberPointer: {
3242 const MemberPointerType *MemberPtr = cast<MemberPointerType>(Val: T);
3243 if (CXXRecordDecl *Class = MemberPtr->getMostRecentCXXRecordDecl())
3244 addAssociatedClassesAndNamespaces(Result, Class);
3245 T = MemberPtr->getPointeeType().getTypePtr();
3246 continue;
3247 }
3248
3249 // As an extension, treat this like a normal pointer.
3250 case Type::BlockPointer:
3251 T = cast<BlockPointerType>(Val: T)->getPointeeType().getTypePtr();
3252 continue;
3253
3254 // References aren't covered by the standard, but that's such an
3255 // obvious defect that we cover them anyway.
3256 case Type::LValueReference:
3257 case Type::RValueReference:
3258 T = cast<ReferenceType>(Val: T)->getPointeeType().getTypePtr();
3259 continue;
3260
3261 // These are fundamental types.
3262 case Type::Vector:
3263 case Type::ExtVector:
3264 case Type::ConstantMatrix:
3265 case Type::Complex:
3266 case Type::BitInt:
3267 break;
3268
3269 // Non-deduced auto types only get here for error cases.
3270 case Type::Auto:
3271 case Type::DeducedTemplateSpecialization:
3272 break;
3273
3274 // If T is an Objective-C object or interface type, or a pointer to an
3275 // object or interface type, the associated namespace is the global
3276 // namespace.
3277 case Type::ObjCObject:
3278 case Type::ObjCInterface:
3279 case Type::ObjCObjectPointer:
3280 Result.Namespaces.insert(X: Result.S.Context.getTranslationUnitDecl());
3281 break;
3282
3283 // Atomic types are just wrappers; use the associations of the
3284 // contained type.
3285 case Type::Atomic:
3286 T = cast<AtomicType>(Val: T)->getValueType().getTypePtr();
3287 continue;
3288 case Type::Pipe:
3289 T = cast<PipeType>(Val: T)->getElementType().getTypePtr();
3290 continue;
3291
3292 // Array parameter types are treated as fundamental types.
3293 case Type::ArrayParameter:
3294 break;
3295
3296 case Type::HLSLAttributedResource:
3297 T = cast<HLSLAttributedResourceType>(Val: T)->getWrappedType().getTypePtr();
3298 break;
3299
3300 // Inline SPIR-V types are treated as fundamental types.
3301 case Type::HLSLInlineSpirv:
3302 break;
3303 }
3304
3305 if (Queue.empty())
3306 break;
3307 T = Queue.pop_back_val();
3308 }
3309}
3310
3311void Sema::FindAssociatedClassesAndNamespaces(
3312 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
3313 AssociatedNamespaceSet &AssociatedNamespaces,
3314 AssociatedClassSet &AssociatedClasses) {
3315 AssociatedNamespaces.clear();
3316 AssociatedClasses.clear();
3317
3318 AssociatedLookup Result(*this, InstantiationLoc,
3319 AssociatedNamespaces, AssociatedClasses);
3320
3321 // C++ [basic.lookup.koenig]p2:
3322 // For each argument type T in the function call, there is a set
3323 // of zero or more associated namespaces and a set of zero or more
3324 // associated classes to be considered. The sets of namespaces and
3325 // classes is determined entirely by the types of the function
3326 // arguments (and the namespace of any template template
3327 // argument).
3328 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
3329 Expr *Arg = Args[ArgIdx];
3330
3331 if (Arg->getType() != Context.OverloadTy) {
3332 addAssociatedClassesAndNamespaces(Result, Ty: Arg->getType());
3333 continue;
3334 }
3335
3336 // [...] In addition, if the argument is the name or address of a
3337 // set of overloaded functions and/or function templates, its
3338 // associated classes and namespaces are the union of those
3339 // associated with each of the members of the set: the namespace
3340 // in which the function or function template is defined and the
3341 // classes and namespaces associated with its (non-dependent)
3342 // parameter types and return type.
3343 OverloadExpr *OE = OverloadExpr::find(E: Arg).Expression;
3344
3345 for (const NamedDecl *D : OE->decls()) {
3346 // Look through any using declarations to find the underlying function.
3347 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
3348
3349 // Add the classes and namespaces associated with the parameter
3350 // types and return type of this function.
3351 addAssociatedClassesAndNamespaces(Result, Ty: FDecl->getType());
3352 }
3353 }
3354}
3355
3356NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
3357 SourceLocation Loc,
3358 LookupNameKind NameKind,
3359 RedeclarationKind Redecl) {
3360 LookupResult R(*this, Name, Loc, NameKind, Redecl);
3361 LookupName(R, S);
3362 return R.getAsSingle<NamedDecl>();
3363}
3364
3365void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
3366 UnresolvedSetImpl &Functions) {
3367 // C++ [over.match.oper]p3:
3368 // -- The set of non-member candidates is the result of the
3369 // unqualified lookup of operator@ in the context of the
3370 // expression according to the usual rules for name lookup in
3371 // unqualified function calls (3.4.2) except that all member
3372 // functions are ignored.
3373 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
3374 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
3375 LookupName(R&: Operators, S);
3376
3377 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
3378 Functions.append(I: Operators.begin(), E: Operators.end());
3379}
3380
3381Sema::SpecialMemberOverloadResult
3382Sema::LookupSpecialMember(CXXRecordDecl *RD, CXXSpecialMemberKind SM,
3383 bool ConstArg, bool VolatileArg, bool RValueThis,
3384 bool ConstThis, bool VolatileThis) {
3385 assert(CanDeclareSpecialMemberFunction(RD) &&
3386 "doing special member lookup into record that isn't fully complete");
3387 RD = RD->getDefinition();
3388 if (RValueThis || ConstThis || VolatileThis)
3389 assert((SM == CXXSpecialMemberKind::CopyAssignment ||
3390 SM == CXXSpecialMemberKind::MoveAssignment) &&
3391 "constructors and destructors always have unqualified lvalue this");
3392 if (ConstArg || VolatileArg)
3393 assert((SM != CXXSpecialMemberKind::DefaultConstructor &&
3394 SM != CXXSpecialMemberKind::Destructor) &&
3395 "parameter-less special members can't have qualified arguments");
3396
3397 // FIXME: Get the caller to pass in a location for the lookup.
3398 SourceLocation LookupLoc = RD->getLocation();
3399
3400 llvm::FoldingSetNodeID ID;
3401 ID.AddPointer(Ptr: RD);
3402 ID.AddInteger(I: llvm::to_underlying(E: SM));
3403 ID.AddInteger(I: ConstArg);
3404 ID.AddInteger(I: VolatileArg);
3405 ID.AddInteger(I: RValueThis);
3406 ID.AddInteger(I: ConstThis);
3407 ID.AddInteger(I: VolatileThis);
3408
3409 void *InsertPoint;
3410 SpecialMemberOverloadResultEntry *Result =
3411 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPos&: InsertPoint);
3412
3413 // This was already cached
3414 if (Result)
3415 return *Result;
3416
3417 Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>();
3418 Result = new (Result) SpecialMemberOverloadResultEntry(ID);
3419 SpecialMemberCache.InsertNode(N: Result, InsertPos: InsertPoint);
3420
3421 if (SM == CXXSpecialMemberKind::Destructor) {
3422 if (RD->needsImplicitDestructor()) {
3423 runWithSufficientStackSpace(Loc: RD->getLocation(), Fn: [&] {
3424 DeclareImplicitDestructor(ClassDecl: RD);
3425 });
3426 }
3427 CXXDestructorDecl *DD = RD->getDestructor();
3428 Result->setMethod(DD);
3429 Result->setKind(DD && !DD->isDeleted()
3430 ? SpecialMemberOverloadResult::Success
3431 : SpecialMemberOverloadResult::NoMemberOrDeleted);
3432 return *Result;
3433 }
3434
3435 // Prepare for overload resolution. Here we construct a synthetic argument
3436 // if necessary and make sure that implicit functions are declared.
3437 CanQualType CanTy = Context.getCanonicalTagType(TD: RD);
3438 DeclarationName Name;
3439 Expr *Arg = nullptr;
3440 unsigned NumArgs;
3441
3442 QualType ArgType = CanTy;
3443 ExprValueKind VK = VK_LValue;
3444
3445 if (SM == CXXSpecialMemberKind::DefaultConstructor) {
3446 Name = Context.DeclarationNames.getCXXConstructorName(Ty: CanTy);
3447 NumArgs = 0;
3448 if (RD->needsImplicitDefaultConstructor()) {
3449 runWithSufficientStackSpace(Loc: RD->getLocation(), Fn: [&] {
3450 DeclareImplicitDefaultConstructor(ClassDecl: RD);
3451 });
3452 }
3453 } else {
3454 if (SM == CXXSpecialMemberKind::CopyConstructor ||
3455 SM == CXXSpecialMemberKind::MoveConstructor) {
3456 Name = Context.DeclarationNames.getCXXConstructorName(Ty: CanTy);
3457 if (RD->needsImplicitCopyConstructor()) {
3458 runWithSufficientStackSpace(Loc: RD->getLocation(), Fn: [&] {
3459 DeclareImplicitCopyConstructor(ClassDecl: RD);
3460 });
3461 }
3462 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor()) {
3463 runWithSufficientStackSpace(Loc: RD->getLocation(), Fn: [&] {
3464 DeclareImplicitMoveConstructor(ClassDecl: RD);
3465 });
3466 }
3467 } else {
3468 Name = Context.DeclarationNames.getCXXOperatorName(Op: OO_Equal);
3469 if (RD->needsImplicitCopyAssignment()) {
3470 runWithSufficientStackSpace(Loc: RD->getLocation(), Fn: [&] {
3471 DeclareImplicitCopyAssignment(ClassDecl: RD);
3472 });
3473 }
3474 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment()) {
3475 runWithSufficientStackSpace(Loc: RD->getLocation(), Fn: [&] {
3476 DeclareImplicitMoveAssignment(ClassDecl: RD);
3477 });
3478 }
3479 }
3480
3481 if (ConstArg)
3482 ArgType.addConst();
3483 if (VolatileArg)
3484 ArgType.addVolatile();
3485
3486 // This isn't /really/ specified by the standard, but it's implied
3487 // we should be working from a PRValue in the case of move to ensure
3488 // that we prefer to bind to rvalue references, and an LValue in the
3489 // case of copy to ensure we don't bind to rvalue references.
3490 // Possibly an XValue is actually correct in the case of move, but
3491 // there is no semantic difference for class types in this restricted
3492 // case.
3493 if (SM == CXXSpecialMemberKind::CopyConstructor ||
3494 SM == CXXSpecialMemberKind::CopyAssignment)
3495 VK = VK_LValue;
3496 else
3497 VK = VK_PRValue;
3498 }
3499
3500 OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK);
3501
3502 if (SM != CXXSpecialMemberKind::DefaultConstructor) {
3503 NumArgs = 1;
3504 Arg = &FakeArg;
3505 }
3506
3507 // Create the object argument
3508 QualType ThisTy = CanTy;
3509 if (ConstThis)
3510 ThisTy.addConst();
3511 if (VolatileThis)
3512 ThisTy.addVolatile();
3513 Expr::Classification Classification =
3514 OpaqueValueExpr(LookupLoc, ThisTy, RValueThis ? VK_PRValue : VK_LValue)
3515 .Classify(Ctx&: Context);
3516
3517 // Now we perform lookup on the name we computed earlier and do overload
3518 // resolution. Lookup is only performed directly into the class since there
3519 // will always be a (possibly implicit) declaration to shadow any others.
3520 OverloadCandidateSet OCS(LookupLoc, OverloadCandidateSet::CSK_Normal);
3521 DeclContext::lookup_result R = RD->lookup(Name);
3522
3523 if (R.empty()) {
3524 // We might have no default constructor because we have a lambda's closure
3525 // type, rather than because there's some other declared constructor.
3526 // Every class has a copy/move constructor, copy/move assignment, and
3527 // destructor.
3528 assert(SM == CXXSpecialMemberKind::DefaultConstructor &&
3529 "lookup for a constructor or assignment operator was empty");
3530 Result->setMethod(nullptr);
3531 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3532 return *Result;
3533 }
3534
3535 // Copy the candidates as our processing of them may load new declarations
3536 // from an external source and invalidate lookup_result.
3537 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
3538
3539 for (NamedDecl *CandDecl : Candidates) {
3540 if (CandDecl->isInvalidDecl())
3541 continue;
3542
3543 DeclAccessPair Cand = DeclAccessPair::make(D: CandDecl, AS: AS_public);
3544 auto CtorInfo = getConstructorInfo(ND: Cand);
3545 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Val: Cand->getUnderlyingDecl())) {
3546 if (SM == CXXSpecialMemberKind::CopyAssignment ||
3547 SM == CXXSpecialMemberKind::MoveAssignment)
3548 AddMethodCandidate(Method: M, FoundDecl: Cand, ActingContext: RD, ObjectType: ThisTy, ObjectClassification: Classification,
3549 Args: llvm::ArrayRef(&Arg, NumArgs), CandidateSet&: OCS, SuppressUserConversions: true);
3550 else if (CtorInfo)
3551 AddOverloadCandidate(Function: CtorInfo.Constructor, FoundDecl: CtorInfo.FoundDecl,
3552 Args: llvm::ArrayRef(&Arg, NumArgs), CandidateSet&: OCS,
3553 /*SuppressUserConversions*/ true);
3554 else
3555 AddOverloadCandidate(Function: M, FoundDecl: Cand, Args: llvm::ArrayRef(&Arg, NumArgs), CandidateSet&: OCS,
3556 /*SuppressUserConversions*/ true);
3557 } else if (FunctionTemplateDecl *Tmpl =
3558 dyn_cast<FunctionTemplateDecl>(Val: Cand->getUnderlyingDecl())) {
3559 if (SM == CXXSpecialMemberKind::CopyAssignment ||
3560 SM == CXXSpecialMemberKind::MoveAssignment)
3561 AddMethodTemplateCandidate(MethodTmpl: Tmpl, FoundDecl: Cand, ActingContext: RD, ExplicitTemplateArgs: nullptr, ObjectType: ThisTy,
3562 ObjectClassification: Classification,
3563 Args: llvm::ArrayRef(&Arg, NumArgs), CandidateSet&: OCS, SuppressUserConversions: true);
3564 else if (CtorInfo)
3565 AddTemplateOverloadCandidate(FunctionTemplate: CtorInfo.ConstructorTmpl,
3566 FoundDecl: CtorInfo.FoundDecl, ExplicitTemplateArgs: nullptr,
3567 Args: llvm::ArrayRef(&Arg, NumArgs), CandidateSet&: OCS, SuppressUserConversions: true);
3568 else
3569 AddTemplateOverloadCandidate(FunctionTemplate: Tmpl, FoundDecl: Cand, ExplicitTemplateArgs: nullptr,
3570 Args: llvm::ArrayRef(&Arg, NumArgs), CandidateSet&: OCS, SuppressUserConversions: true);
3571 } else {
3572 assert(isa<UsingDecl>(Cand.getDecl()) &&
3573 "illegal Kind of operator = Decl");
3574 }
3575 }
3576
3577 OverloadCandidateSet::iterator Best;
3578 switch (OCS.BestViableFunction(S&: *this, Loc: LookupLoc, Best)) {
3579 case OR_Success:
3580 Result->setMethod(cast<CXXMethodDecl>(Val: Best->Function));
3581 Result->setKind(SpecialMemberOverloadResult::Success);
3582 break;
3583
3584 case OR_Deleted:
3585 Result->setMethod(cast<CXXMethodDecl>(Val: Best->Function));
3586 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3587 break;
3588
3589 case OR_Ambiguous:
3590 Result->setMethod(nullptr);
3591 Result->setKind(SpecialMemberOverloadResult::Ambiguous);
3592 break;
3593
3594 case OR_No_Viable_Function:
3595 Result->setMethod(nullptr);
3596 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3597 break;
3598 }
3599
3600 return *Result;
3601}
3602
3603CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) {
3604 SpecialMemberOverloadResult Result =
3605 LookupSpecialMember(RD: Class, SM: CXXSpecialMemberKind::DefaultConstructor,
3606 ConstArg: false, VolatileArg: false, RValueThis: false, ConstThis: false, VolatileThis: false);
3607
3608 return cast_or_null<CXXConstructorDecl>(Val: Result.getMethod());
3609}
3610
3611CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class,
3612 unsigned Quals) {
3613 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3614 "non-const, non-volatile qualifiers for copy ctor arg");
3615 SpecialMemberOverloadResult Result = LookupSpecialMember(
3616 RD: Class, SM: CXXSpecialMemberKind::CopyConstructor, ConstArg: Quals & Qualifiers::Const,
3617 VolatileArg: Quals & Qualifiers::Volatile, RValueThis: false, ConstThis: false, VolatileThis: false);
3618
3619 return cast_or_null<CXXConstructorDecl>(Val: Result.getMethod());
3620}
3621
3622CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class,
3623 unsigned Quals) {
3624 SpecialMemberOverloadResult Result = LookupSpecialMember(
3625 RD: Class, SM: CXXSpecialMemberKind::MoveConstructor, ConstArg: Quals & Qualifiers::Const,
3626 VolatileArg: Quals & Qualifiers::Volatile, RValueThis: false, ConstThis: false, VolatileThis: false);
3627
3628 return cast_or_null<CXXConstructorDecl>(Val: Result.getMethod());
3629}
3630
3631DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) {
3632 // If the implicit constructors have not yet been declared, do so now.
3633 if (CanDeclareSpecialMemberFunction(Class)) {
3634 runWithSufficientStackSpace(Loc: Class->getLocation(), Fn: [&] {
3635 if (Class->needsImplicitDefaultConstructor())
3636 DeclareImplicitDefaultConstructor(ClassDecl: Class);
3637 if (Class->needsImplicitCopyConstructor())
3638 DeclareImplicitCopyConstructor(ClassDecl: Class);
3639 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
3640 DeclareImplicitMoveConstructor(ClassDecl: Class);
3641 });
3642 }
3643
3644 CanQualType T = Context.getCanonicalTagType(TD: Class);
3645 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(Ty: T);
3646 return Class->lookup(Name);
3647}
3648
3649CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class,
3650 unsigned Quals, bool RValueThis,
3651 unsigned ThisQuals) {
3652 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3653 "non-const, non-volatile qualifiers for copy assignment arg");
3654 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3655 "non-const, non-volatile qualifiers for copy assignment this");
3656 SpecialMemberOverloadResult Result = LookupSpecialMember(
3657 RD: Class, SM: CXXSpecialMemberKind::CopyAssignment, ConstArg: Quals & Qualifiers::Const,
3658 VolatileArg: Quals & Qualifiers::Volatile, RValueThis, ConstThis: ThisQuals & Qualifiers::Const,
3659 VolatileThis: ThisQuals & Qualifiers::Volatile);
3660
3661 return Result.getMethod();
3662}
3663
3664CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class,
3665 unsigned Quals,
3666 bool RValueThis,
3667 unsigned ThisQuals) {
3668 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3669 "non-const, non-volatile qualifiers for copy assignment this");
3670 SpecialMemberOverloadResult Result = LookupSpecialMember(
3671 RD: Class, SM: CXXSpecialMemberKind::MoveAssignment, ConstArg: Quals & Qualifiers::Const,
3672 VolatileArg: Quals & Qualifiers::Volatile, RValueThis, ConstThis: ThisQuals & Qualifiers::Const,
3673 VolatileThis: ThisQuals & Qualifiers::Volatile);
3674
3675 return Result.getMethod();
3676}
3677
3678CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) {
3679 return cast_or_null<CXXDestructorDecl>(
3680 Val: LookupSpecialMember(RD: Class, SM: CXXSpecialMemberKind::Destructor, ConstArg: false, VolatileArg: false,
3681 RValueThis: false, ConstThis: false, VolatileThis: false)
3682 .getMethod());
3683}
3684
3685Sema::LiteralOperatorLookupResult
3686Sema::LookupLiteralOperator(Scope *S, LookupResult &R,
3687 ArrayRef<QualType> ArgTys, bool AllowRaw,
3688 bool AllowTemplate, bool AllowStringTemplatePack,
3689 bool DiagnoseMissing, StringLiteral *StringLit) {
3690 LookupName(R, S);
3691 assert(R.getResultKind() != LookupResultKind::Ambiguous &&
3692 "literal operator lookup can't be ambiguous");
3693
3694 // Filter the lookup results appropriately.
3695 LookupResult::Filter F = R.makeFilter();
3696
3697 bool AllowCooked = true;
3698 bool FoundRaw = false;
3699 bool FoundTemplate = false;
3700 bool FoundStringTemplatePack = false;
3701 bool FoundCooked = false;
3702
3703 while (F.hasNext()) {
3704 Decl *D = F.next();
3705 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(Val: D))
3706 D = USD->getTargetDecl();
3707
3708 // If the declaration we found is invalid, skip it.
3709 if (D->isInvalidDecl()) {
3710 F.erase();
3711 continue;
3712 }
3713
3714 bool IsRaw = false;
3715 bool IsTemplate = false;
3716 bool IsStringTemplatePack = false;
3717 bool IsCooked = false;
3718
3719 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: D)) {
3720 if (FD->getNumParams() == 1 &&
3721 FD->getParamDecl(i: 0)->getType()->getAs<PointerType>())
3722 IsRaw = true;
3723 else if (FD->getNumParams() == ArgTys.size()) {
3724 IsCooked = true;
3725 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
3726 QualType ParamTy = FD->getParamDecl(i: ArgIdx)->getType();
3727 if (!Context.hasSameUnqualifiedType(T1: ArgTys[ArgIdx], T2: ParamTy)) {
3728 IsCooked = false;
3729 break;
3730 }
3731 }
3732 }
3733 }
3734 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(Val: D)) {
3735 TemplateParameterList *Params = FD->getTemplateParameters();
3736 if (Params->size() == 1) {
3737 IsTemplate = true;
3738 if (!Params->getParam(Idx: 0)->isTemplateParameterPack() && !StringLit) {
3739 // Implied but not stated: user-defined integer and floating literals
3740 // only ever use numeric literal operator templates, not templates
3741 // taking a parameter of class type.
3742 F.erase();
3743 continue;
3744 }
3745
3746 // A string literal template is only considered if the string literal
3747 // is a well-formed template argument for the template parameter.
3748 if (StringLit) {
3749 SFINAETrap Trap(*this);
3750 CheckTemplateArgumentInfo CTAI;
3751 TemplateArgumentLoc Arg(
3752 TemplateArgument(StringLit, /*IsCanonical=*/false), StringLit);
3753 if (CheckTemplateArgument(
3754 Param: Params->getParam(Idx: 0), Arg, Template: FD, TemplateLoc: R.getNameLoc(), RAngleLoc: R.getNameLoc(),
3755 /*ArgumentPackIndex=*/0, CTAI, CTAK: CTAK_Specified) ||
3756 Trap.hasErrorOccurred())
3757 IsTemplate = false;
3758 }
3759 } else {
3760 IsStringTemplatePack = true;
3761 }
3762 }
3763
3764 if (AllowTemplate && StringLit && IsTemplate) {
3765 FoundTemplate = true;
3766 AllowRaw = false;
3767 AllowCooked = false;
3768 AllowStringTemplatePack = false;
3769 if (FoundRaw || FoundCooked || FoundStringTemplatePack) {
3770 F.restart();
3771 FoundRaw = FoundCooked = FoundStringTemplatePack = false;
3772 }
3773 } else if (AllowCooked && IsCooked) {
3774 FoundCooked = true;
3775 AllowRaw = false;
3776 AllowTemplate = StringLit;
3777 AllowStringTemplatePack = false;
3778 if (FoundRaw || FoundTemplate || FoundStringTemplatePack) {
3779 // Go through again and remove the raw and template decls we've
3780 // already found.
3781 F.restart();
3782 FoundRaw = FoundTemplate = FoundStringTemplatePack = false;
3783 }
3784 } else if (AllowRaw && IsRaw) {
3785 FoundRaw = true;
3786 } else if (AllowTemplate && IsTemplate) {
3787 FoundTemplate = true;
3788 } else if (AllowStringTemplatePack && IsStringTemplatePack) {
3789 FoundStringTemplatePack = true;
3790 } else {
3791 F.erase();
3792 }
3793 }
3794
3795 F.done();
3796
3797 // Per C++20 [lex.ext]p5, we prefer the template form over the non-template
3798 // form for string literal operator templates.
3799 if (StringLit && FoundTemplate)
3800 return LOLR_Template;
3801
3802 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
3803 // parameter type, that is used in preference to a raw literal operator
3804 // or literal operator template.
3805 if (FoundCooked)
3806 return LOLR_Cooked;
3807
3808 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
3809 // operator template, but not both.
3810 if (FoundRaw && FoundTemplate) {
3811 Diag(Loc: R.getNameLoc(), DiagID: diag::err_ovl_ambiguous_call) << R.getLookupName();
3812 for (const NamedDecl *D : R)
3813 NoteOverloadCandidate(Found: D, Fn: D->getUnderlyingDecl()->getAsFunction());
3814 return LOLR_Error;
3815 }
3816
3817 if (FoundRaw)
3818 return LOLR_Raw;
3819
3820 if (FoundTemplate)
3821 return LOLR_Template;
3822
3823 if (FoundStringTemplatePack)
3824 return LOLR_StringTemplatePack;
3825
3826 // Didn't find anything we could use.
3827 if (DiagnoseMissing) {
3828 Diag(Loc: R.getNameLoc(), DiagID: diag::err_ovl_no_viable_literal_operator)
3829 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
3830 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
3831 << (AllowTemplate || AllowStringTemplatePack);
3832 return LOLR_Error;
3833 }
3834
3835 return LOLR_ErrorNoDiagnostic;
3836}
3837
3838void ADLResult::insert(NamedDecl *New) {
3839 NamedDecl *&Old = Decls[cast<NamedDecl>(Val: New->getCanonicalDecl())];
3840
3841 // If we haven't yet seen a decl for this key, or the last decl
3842 // was exactly this one, we're done.
3843 if (Old == nullptr || Old == New) {
3844 Old = New;
3845 return;
3846 }
3847
3848 // Otherwise, decide which is a more recent redeclaration.
3849 FunctionDecl *OldFD = Old->getAsFunction();
3850 FunctionDecl *NewFD = New->getAsFunction();
3851
3852 FunctionDecl *Cursor = NewFD;
3853 while (true) {
3854 Cursor = Cursor->getPreviousDecl();
3855
3856 // If we got to the end without finding OldFD, OldFD is the newer
3857 // declaration; leave things as they are.
3858 if (!Cursor) return;
3859
3860 // If we do find OldFD, then NewFD is newer.
3861 if (Cursor == OldFD) break;
3862
3863 // Otherwise, keep looking.
3864 }
3865
3866 Old = New;
3867}
3868
3869void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
3870 ArrayRef<Expr *> Args, ADLResult &Result) {
3871 // Find all of the associated namespaces and classes based on the
3872 // arguments we have.
3873 AssociatedNamespaceSet AssociatedNamespaces;
3874 AssociatedClassSet AssociatedClasses;
3875 FindAssociatedClassesAndNamespaces(InstantiationLoc: Loc, Args,
3876 AssociatedNamespaces,
3877 AssociatedClasses);
3878
3879 // C++ [basic.lookup.argdep]p3:
3880 // Let X be the lookup set produced by unqualified lookup (3.4.1)
3881 // and let Y be the lookup set produced by argument dependent
3882 // lookup (defined as follows). If X contains [...] then Y is
3883 // empty. Otherwise Y is the set of declarations found in the
3884 // namespaces associated with the argument types as described
3885 // below. The set of declarations found by the lookup of the name
3886 // is the union of X and Y.
3887 //
3888 // Here, we compute Y and add its members to the overloaded
3889 // candidate set.
3890 for (auto *NS : AssociatedNamespaces) {
3891 // When considering an associated namespace, the lookup is the
3892 // same as the lookup performed when the associated namespace is
3893 // used as a qualifier (3.4.3.2) except that:
3894 //
3895 // -- Any using-directives in the associated namespace are
3896 // ignored.
3897 //
3898 // -- Any namespace-scope friend functions declared in
3899 // associated classes are visible within their respective
3900 // namespaces even if they are not visible during an ordinary
3901 // lookup (11.4).
3902 //
3903 // C++20 [basic.lookup.argdep] p4.3
3904 // -- are exported, are attached to a named module M, do not appear
3905 // in the translation unit containing the point of the lookup, and
3906 // have the same innermost enclosing non-inline namespace scope as
3907 // a declaration of an associated entity attached to M.
3908 DeclContext::lookup_result R = NS->lookup(Name);
3909 for (auto *D : R) {
3910 auto *Underlying = D;
3911 if (auto *USD = dyn_cast<UsingShadowDecl>(Val: D))
3912 Underlying = USD->getTargetDecl();
3913
3914 if (!isa<FunctionDecl>(Val: Underlying) &&
3915 !isa<FunctionTemplateDecl>(Val: Underlying))
3916 continue;
3917
3918 // The declaration is visible to argument-dependent lookup if either
3919 // it's ordinarily visible or declared as a friend in an associated
3920 // class.
3921 bool Visible = false;
3922 for (D = D->getMostRecentDecl(); D;
3923 D = cast_or_null<NamedDecl>(Val: D->getPreviousDecl())) {
3924 if (D->getIdentifierNamespace() & Decl::IDNS_Ordinary) {
3925 if (isVisible(D)) {
3926 Visible = true;
3927 break;
3928 }
3929
3930 if (!D->getOwningModule() ||
3931 !D->getOwningModule()->getTopLevelModule()->isNamedModule())
3932 continue;
3933
3934 if (D->isInExportDeclContext()) {
3935 Module *FM = D->getOwningModule();
3936 // C++20 [basic.lookup.argdep] p4.3 .. are exported ...
3937 // exports are only valid in module purview and outside of any
3938 // PMF (although a PMF should not even be present in a module
3939 // with an import).
3940 assert(FM &&
3941 (FM->isNamedModule() || FM->isImplicitGlobalModule()) &&
3942 !FM->isPrivateModule() && "bad export context");
3943 // .. are attached to a named module M, do not appear in the
3944 // translation unit containing the point of the lookup..
3945 if (D->isInAnotherModuleUnit() &&
3946 llvm::any_of(Range&: AssociatedClasses, P: [&](auto *E) {
3947 // ... and have the same innermost enclosing non-inline
3948 // namespace scope as a declaration of an associated entity
3949 // attached to M
3950 if (E->getOwningModule() != FM)
3951 return false;
3952 // TODO: maybe this could be cached when generating the
3953 // associated namespaces / entities.
3954 DeclContext *Ctx = E->getDeclContext();
3955 while (!Ctx->isFileContext() || Ctx->isInlineNamespace())
3956 Ctx = Ctx->getParent();
3957 return Ctx == NS;
3958 })) {
3959 Visible = true;
3960 break;
3961 }
3962 }
3963 }
3964
3965 if (D->getFriendObjectKind()) {
3966 auto *RD = cast<CXXRecordDecl>(Val: D->getLexicalDeclContext());
3967 // [basic.lookup.argdep]p4:
3968 // Argument-dependent lookup finds all declarations of functions and
3969 // function templates that
3970 // - ...
3971 // - are declared as a friend ([class.friend]) of any class with a
3972 // reachable definition in the set of associated entities,
3973 //
3974 // FIXME: If there's a merged definition of D that is reachable, then
3975 // the friend declaration should be considered.
3976 if (AssociatedClasses.count(key: RD) && isReachable(D)) {
3977 Visible = true;
3978 break;
3979 }
3980 }
3981 }
3982
3983 // FIXME: Preserve D as the FoundDecl.
3984 if (Visible)
3985 Result.insert(New: Underlying);
3986 }
3987 }
3988}
3989
3990//----------------------------------------------------------------------------
3991// Search for all visible declarations.
3992//----------------------------------------------------------------------------
3993VisibleDeclConsumer::~VisibleDeclConsumer() { }
3994
3995bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
3996
3997namespace {
3998
3999class ShadowContextRAII;
4000
4001class VisibleDeclsRecord {
4002public:
4003 /// An entry in the shadow map, which is optimized to store a
4004 /// single declaration (the common case) but can also store a list
4005 /// of declarations.
4006 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
4007
4008private:
4009 /// A mapping from declaration names to the declarations that have
4010 /// this name within a particular scope.
4011 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
4012
4013 /// A list of shadow maps, which is used to model name hiding.
4014 std::list<ShadowMap> ShadowMaps;
4015
4016 /// The declaration contexts we have already visited.
4017 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
4018
4019 friend class ShadowContextRAII;
4020
4021public:
4022 /// Determine whether we have already visited this context
4023 /// (and, if not, note that we are going to visit that context now).
4024 bool visitedContext(DeclContext *Ctx) {
4025 return !VisitedContexts.insert(Ptr: Ctx).second;
4026 }
4027
4028 bool alreadyVisitedContext(DeclContext *Ctx) {
4029 return VisitedContexts.count(Ptr: Ctx);
4030 }
4031
4032 /// Determine whether the given declaration is hidden in the
4033 /// current scope.
4034 ///
4035 /// \returns the declaration that hides the given declaration, or
4036 /// NULL if no such declaration exists.
4037 NamedDecl *checkHidden(NamedDecl *ND);
4038
4039 /// Add a declaration to the current shadow map.
4040 void add(NamedDecl *ND) {
4041 ShadowMaps.back()[ND->getDeclName()].push_back(NewVal: ND);
4042 }
4043};
4044
4045/// RAII object that records when we've entered a shadow context.
4046class ShadowContextRAII {
4047 VisibleDeclsRecord &Visible;
4048
4049 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
4050
4051public:
4052 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
4053 Visible.ShadowMaps.emplace_back();
4054 }
4055
4056 ~ShadowContextRAII() {
4057 Visible.ShadowMaps.pop_back();
4058 }
4059};
4060
4061} // end anonymous namespace
4062
4063NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
4064 unsigned IDNS = ND->getIdentifierNamespace();
4065 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
4066 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
4067 SM != SMEnd; ++SM) {
4068 ShadowMap::iterator Pos = SM->find(Val: ND->getDeclName());
4069 if (Pos == SM->end())
4070 continue;
4071
4072 for (auto *D : Pos->second) {
4073 // A tag declaration does not hide a non-tag declaration.
4074 if (D->hasTagIdentifierNamespace() &&
4075 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
4076 Decl::IDNS_ObjCProtocol)))
4077 continue;
4078
4079 // Protocols are in distinct namespaces from everything else.
4080 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
4081 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
4082 D->getIdentifierNamespace() != IDNS)
4083 continue;
4084
4085 // Functions and function templates in the same scope overload
4086 // rather than hide. FIXME: Look for hiding based on function
4087 // signatures!
4088 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
4089 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
4090 SM == ShadowMaps.rbegin())
4091 continue;
4092
4093 // A shadow declaration that's created by a resolved using declaration
4094 // is not hidden by the same using declaration.
4095 if (isa<UsingShadowDecl>(Val: ND) && isa<UsingDecl>(Val: D) &&
4096 cast<UsingShadowDecl>(Val: ND)->getIntroducer() == D)
4097 continue;
4098
4099 // We've found a declaration that hides this one.
4100 return D;
4101 }
4102 }
4103
4104 return nullptr;
4105}
4106
4107namespace {
4108class LookupVisibleHelper {
4109public:
4110 LookupVisibleHelper(VisibleDeclConsumer &Consumer, bool IncludeDependentBases,
4111 bool LoadExternal)
4112 : Consumer(Consumer), IncludeDependentBases(IncludeDependentBases),
4113 LoadExternal(LoadExternal) {}
4114
4115 void lookupVisibleDecls(Sema &SemaRef, Scope *S, Sema::LookupNameKind Kind,
4116 bool IncludeGlobalScope) {
4117 // Determine the set of using directives available during
4118 // unqualified name lookup.
4119 Scope *Initial = S;
4120 UnqualUsingDirectiveSet UDirs(SemaRef);
4121 if (SemaRef.getLangOpts().CPlusPlus) {
4122 // Find the first namespace or translation-unit scope.
4123 while (S && !isNamespaceOrTranslationUnitScope(S))
4124 S = S->getParent();
4125
4126 UDirs.visitScopeChain(S: Initial, InnermostFileScope: S);
4127 }
4128 UDirs.done();
4129
4130 // Look for visible declarations.
4131 LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind);
4132 Result.setAllowHidden(Consumer.includeHiddenDecls());
4133 if (!IncludeGlobalScope)
4134 Visited.visitedContext(Ctx: SemaRef.getASTContext().getTranslationUnitDecl());
4135 ShadowContextRAII Shadow(Visited);
4136 lookupInScope(S: Initial, Result, UDirs);
4137 }
4138
4139 void lookupVisibleDecls(Sema &SemaRef, DeclContext *Ctx,
4140 Sema::LookupNameKind Kind, bool IncludeGlobalScope) {
4141 LookupResult Result(SemaRef, DeclarationName(), SourceLocation(), Kind);
4142 Result.setAllowHidden(Consumer.includeHiddenDecls());
4143 if (!IncludeGlobalScope)
4144 Visited.visitedContext(Ctx: SemaRef.getASTContext().getTranslationUnitDecl());
4145
4146 ShadowContextRAII Shadow(Visited);
4147 lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/true,
4148 /*InBaseClass=*/false);
4149 }
4150
4151private:
4152 void lookupInDeclContext(DeclContext *Ctx, LookupResult &Result,
4153 bool QualifiedNameLookup, bool InBaseClass) {
4154 if (!Ctx)
4155 return;
4156
4157 // Make sure we don't visit the same context twice.
4158 if (Visited.visitedContext(Ctx: Ctx->getPrimaryContext()))
4159 return;
4160
4161 Consumer.EnteredContext(Ctx);
4162
4163 // Outside C++, lookup results for the TU live on identifiers.
4164 if (isa<TranslationUnitDecl>(Val: Ctx) &&
4165 !Result.getSema().getLangOpts().CPlusPlus) {
4166 auto &S = Result.getSema();
4167 auto &Idents = S.Context.Idents;
4168
4169 // Ensure all external identifiers are in the identifier table.
4170 if (LoadExternal)
4171 if (IdentifierInfoLookup *External =
4172 Idents.getExternalIdentifierLookup()) {
4173 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4174 for (StringRef Name = Iter->Next(); !Name.empty();
4175 Name = Iter->Next())
4176 Idents.get(Name);
4177 }
4178
4179 // Walk all lookup results in the TU for each identifier.
4180 for (const auto &Ident : Idents) {
4181 for (auto I = S.IdResolver.begin(Name: Ident.getValue()),
4182 E = S.IdResolver.end();
4183 I != E; ++I) {
4184 if (S.IdResolver.isDeclInScope(D: *I, Ctx)) {
4185 if (NamedDecl *ND = Result.getAcceptableDecl(D: *I)) {
4186 Consumer.FoundDecl(ND, Hiding: Visited.checkHidden(ND), Ctx, InBaseClass);
4187 Visited.add(ND);
4188 }
4189 }
4190 }
4191 }
4192
4193 return;
4194 }
4195
4196 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Val: Ctx))
4197 Result.getSema().ForceDeclarationOfImplicitMembers(Class);
4198
4199 llvm::SmallVector<NamedDecl *, 4> DeclsToVisit;
4200 // We sometimes skip loading namespace-level results (they tend to be huge).
4201 bool Load = LoadExternal ||
4202 !(isa<TranslationUnitDecl>(Val: Ctx) || isa<NamespaceDecl>(Val: Ctx));
4203 // Enumerate all of the results in this context.
4204 for (DeclContextLookupResult R :
4205 Load ? Ctx->lookups()
4206 : Ctx->noload_lookups(/*PreserveInternalState=*/false))
4207 for (auto *D : R)
4208 // Rather than visit immediately, we put ND into a vector and visit
4209 // all decls, in order, outside of this loop. The reason is that
4210 // Consumer.FoundDecl() and LookupResult::getAcceptableDecl(D)
4211 // may invalidate the iterators used in the two
4212 // loops above.
4213 DeclsToVisit.push_back(Elt: D);
4214
4215 for (auto *D : DeclsToVisit)
4216 if (auto *ND = Result.getAcceptableDecl(D)) {
4217 Consumer.FoundDecl(ND, Hiding: Visited.checkHidden(ND), Ctx, InBaseClass);
4218 Visited.add(ND);
4219 }
4220
4221 DeclsToVisit.clear();
4222
4223 // Traverse using directives for qualified name lookup.
4224 if (QualifiedNameLookup) {
4225 ShadowContextRAII Shadow(Visited);
4226 for (auto *I : Ctx->using_directives()) {
4227 if (!Result.getSema().isVisible(D: I))
4228 continue;
4229 lookupInDeclContext(Ctx: I->getNominatedNamespace(), Result,
4230 QualifiedNameLookup, InBaseClass);
4231 }
4232 }
4233
4234 // Traverse the contexts of inherited C++ classes.
4235 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Val: Ctx)) {
4236 if (!Record->hasDefinition())
4237 return;
4238
4239 for (const auto &B : Record->bases()) {
4240 QualType BaseType = B.getType();
4241
4242 RecordDecl *RD;
4243 if (BaseType->isDependentType()) {
4244 if (!IncludeDependentBases) {
4245 // Don't look into dependent bases, because name lookup can't look
4246 // there anyway.
4247 continue;
4248 }
4249 const auto *TST = BaseType->getAs<TemplateSpecializationType>();
4250 if (!TST)
4251 continue;
4252 TemplateName TN = TST->getTemplateName();
4253 const auto *TD =
4254 dyn_cast_or_null<ClassTemplateDecl>(Val: TN.getAsTemplateDecl());
4255 if (!TD)
4256 continue;
4257 RD = TD->getTemplatedDecl();
4258 } else {
4259 RD = BaseType->getAsCXXRecordDecl();
4260 if (!RD)
4261 continue;
4262 }
4263
4264 // FIXME: It would be nice to be able to determine whether referencing
4265 // a particular member would be ambiguous. For example, given
4266 //
4267 // struct A { int member; };
4268 // struct B { int member; };
4269 // struct C : A, B { };
4270 //
4271 // void f(C *c) { c->### }
4272 //
4273 // accessing 'member' would result in an ambiguity. However, we
4274 // could be smart enough to qualify the member with the base
4275 // class, e.g.,
4276 //
4277 // c->B::member
4278 //
4279 // or
4280 //
4281 // c->A::member
4282
4283 // Find results in this base class (and its bases).
4284 ShadowContextRAII Shadow(Visited);
4285 lookupInDeclContext(Ctx: RD, Result, QualifiedNameLookup,
4286 /*InBaseClass=*/true);
4287 }
4288 }
4289
4290 // Traverse the contexts of Objective-C classes.
4291 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Val: Ctx)) {
4292 // Traverse categories.
4293 for (auto *Cat : IFace->visible_categories()) {
4294 ShadowContextRAII Shadow(Visited);
4295 lookupInDeclContext(Ctx: Cat, Result, QualifiedNameLookup,
4296 /*InBaseClass=*/false);
4297 }
4298
4299 // Traverse protocols.
4300 for (auto *I : IFace->all_referenced_protocols()) {
4301 ShadowContextRAII Shadow(Visited);
4302 lookupInDeclContext(Ctx: I, Result, QualifiedNameLookup,
4303 /*InBaseClass=*/false);
4304 }
4305
4306 // Traverse the superclass.
4307 if (IFace->getSuperClass()) {
4308 ShadowContextRAII Shadow(Visited);
4309 lookupInDeclContext(Ctx: IFace->getSuperClass(), Result, QualifiedNameLookup,
4310 /*InBaseClass=*/true);
4311 }
4312
4313 // If there is an implementation, traverse it. We do this to find
4314 // synthesized ivars.
4315 if (IFace->getImplementation()) {
4316 ShadowContextRAII Shadow(Visited);
4317 lookupInDeclContext(Ctx: IFace->getImplementation(), Result,
4318 QualifiedNameLookup, InBaseClass);
4319 }
4320 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Val: Ctx)) {
4321 for (auto *I : Protocol->protocols()) {
4322 ShadowContextRAII Shadow(Visited);
4323 lookupInDeclContext(Ctx: I, Result, QualifiedNameLookup,
4324 /*InBaseClass=*/false);
4325 }
4326 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Val: Ctx)) {
4327 for (auto *I : Category->protocols()) {
4328 ShadowContextRAII Shadow(Visited);
4329 lookupInDeclContext(Ctx: I, Result, QualifiedNameLookup,
4330 /*InBaseClass=*/false);
4331 }
4332
4333 // If there is an implementation, traverse it.
4334 if (Category->getImplementation()) {
4335 ShadowContextRAII Shadow(Visited);
4336 lookupInDeclContext(Ctx: Category->getImplementation(), Result,
4337 QualifiedNameLookup, /*InBaseClass=*/true);
4338 }
4339 }
4340 }
4341
4342 void lookupInScope(Scope *S, LookupResult &Result,
4343 UnqualUsingDirectiveSet &UDirs) {
4344 // No clients run in this mode and it's not supported. Please add tests and
4345 // remove the assertion if you start relying on it.
4346 assert(!IncludeDependentBases && "Unsupported flag for lookupInScope");
4347
4348 if (!S)
4349 return;
4350
4351 if (!S->getEntity() ||
4352 (!S->getParent() && !Visited.alreadyVisitedContext(Ctx: S->getEntity())) ||
4353 (S->getEntity())->isFunctionOrMethod()) {
4354 FindLocalExternScope FindLocals(Result);
4355 // Walk through the declarations in this Scope. The consumer might add new
4356 // decls to the scope as part of deserialization, so make a copy first.
4357 SmallVector<Decl *, 8> ScopeDecls(S->decls().begin(), S->decls().end());
4358 for (Decl *D : ScopeDecls) {
4359 if (NamedDecl *ND = dyn_cast<NamedDecl>(Val: D))
4360 if ((ND = Result.getAcceptableDecl(D: ND))) {
4361 Consumer.FoundDecl(ND, Hiding: Visited.checkHidden(ND), Ctx: nullptr, InBaseClass: false);
4362 Visited.add(ND);
4363 }
4364 }
4365 }
4366
4367 DeclContext *Entity = S->getLookupEntity();
4368 if (Entity) {
4369 // Look into this scope's declaration context, along with any of its
4370 // parent lookup contexts (e.g., enclosing classes), up to the point
4371 // where we hit the context stored in the next outer scope.
4372 DeclContext *OuterCtx = findOuterContext(S);
4373
4374 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(DC: OuterCtx);
4375 Ctx = Ctx->getLookupParent()) {
4376 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Val: Ctx)) {
4377 if (Method->isInstanceMethod()) {
4378 // For instance methods, look for ivars in the method's interface.
4379 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
4380 Result.getNameLoc(),
4381 Sema::LookupMemberName);
4382 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
4383 lookupInDeclContext(Ctx: IFace, Result&: IvarResult,
4384 /*QualifiedNameLookup=*/false,
4385 /*InBaseClass=*/false);
4386 }
4387 }
4388
4389 // We've already performed all of the name lookup that we need
4390 // to for Objective-C methods; the next context will be the
4391 // outer scope.
4392 break;
4393 }
4394
4395 if (Ctx->isFunctionOrMethod())
4396 continue;
4397
4398 lookupInDeclContext(Ctx, Result, /*QualifiedNameLookup=*/false,
4399 /*InBaseClass=*/false);
4400 }
4401 } else if (!S->getParent()) {
4402 // Look into the translation unit scope. We walk through the translation
4403 // unit's declaration context, because the Scope itself won't have all of
4404 // the declarations if we loaded a precompiled header.
4405 // FIXME: We would like the translation unit's Scope object to point to
4406 // the translation unit, so we don't need this special "if" branch.
4407 // However, doing so would force the normal C++ name-lookup code to look
4408 // into the translation unit decl when the IdentifierInfo chains would
4409 // suffice. Once we fix that problem (which is part of a more general
4410 // "don't look in DeclContexts unless we have to" optimization), we can
4411 // eliminate this.
4412 Entity = Result.getSema().Context.getTranslationUnitDecl();
4413 lookupInDeclContext(Ctx: Entity, Result, /*QualifiedNameLookup=*/false,
4414 /*InBaseClass=*/false);
4415 }
4416
4417 if (Entity) {
4418 // Lookup visible declarations in any namespaces found by using
4419 // directives.
4420 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(DC: Entity))
4421 lookupInDeclContext(
4422 Ctx: const_cast<DeclContext *>(UUE.getNominatedNamespace()), Result,
4423 /*QualifiedNameLookup=*/false,
4424 /*InBaseClass=*/false);
4425 }
4426
4427 // Lookup names in the parent scope.
4428 ShadowContextRAII Shadow(Visited);
4429 lookupInScope(S: S->getParent(), Result, UDirs);
4430 }
4431
4432private:
4433 VisibleDeclsRecord Visited;
4434 VisibleDeclConsumer &Consumer;
4435 bool IncludeDependentBases;
4436 bool LoadExternal;
4437};
4438} // namespace
4439
4440void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
4441 VisibleDeclConsumer &Consumer,
4442 bool IncludeGlobalScope, bool LoadExternal) {
4443 LookupVisibleHelper H(Consumer, /*IncludeDependentBases=*/false,
4444 LoadExternal);
4445 H.lookupVisibleDecls(SemaRef&: *this, S, Kind, IncludeGlobalScope);
4446}
4447
4448void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
4449 VisibleDeclConsumer &Consumer,
4450 bool IncludeGlobalScope,
4451 bool IncludeDependentBases, bool LoadExternal) {
4452 LookupVisibleHelper H(Consumer, IncludeDependentBases, LoadExternal);
4453 H.lookupVisibleDecls(SemaRef&: *this, Ctx, Kind, IncludeGlobalScope);
4454}
4455
4456LabelDecl *Sema::LookupExistingLabel(IdentifierInfo *II, SourceLocation Loc) {
4457 NamedDecl *Res = LookupSingleName(S: CurScope, Name: II, Loc, NameKind: LookupLabel,
4458 Redecl: RedeclarationKind::NotForRedeclaration);
4459 // If we found a label, check to see if it is in the same context as us.
4460 // When in a Block, we don't want to reuse a label in an enclosing function.
4461 if (!Res || Res->getDeclContext() != CurContext)
4462 return nullptr;
4463 return cast<LabelDecl>(Val: Res);
4464}
4465
4466LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc,
4467 SourceLocation GnuLabelLoc) {
4468 if (GnuLabelLoc.isValid()) {
4469 // Local label definitions always shadow existing labels.
4470 auto *Res = LabelDecl::Create(C&: Context, DC: CurContext, IdentL: Loc, II, GnuLabelL: GnuLabelLoc);
4471 Scope *S = CurScope;
4472 PushOnScopeChains(D: Res, S, AddToContext: true);
4473 return cast<LabelDecl>(Val: Res);
4474 }
4475
4476 // Not a GNU local label.
4477 LabelDecl *Res = LookupExistingLabel(II, Loc);
4478 if (!Res) {
4479 // If not forward referenced or defined already, create the backing decl.
4480 Res = LabelDecl::Create(C&: Context, DC: CurContext, IdentL: Loc, II);
4481 Scope *S = CurScope->getFnParent();
4482 assert(S && "Not in a function?");
4483 PushOnScopeChains(D: Res, S, AddToContext: true);
4484 }
4485 return Res;
4486}
4487
4488//===----------------------------------------------------------------------===//
4489// Typo correction
4490//===----------------------------------------------------------------------===//
4491
4492static bool isCandidateViable(CorrectionCandidateCallback &CCC,
4493 TypoCorrection &Candidate) {
4494 Candidate.setCallbackDistance(CCC.RankCandidate(candidate: Candidate));
4495 return Candidate.getEditDistance(Normalized: false) != TypoCorrection::InvalidDistance;
4496}
4497
4498static void LookupPotentialTypoResult(Sema &SemaRef,
4499 LookupResult &Res,
4500 IdentifierInfo *Name,
4501 Scope *S, CXXScopeSpec *SS,
4502 DeclContext *MemberContext,
4503 bool EnteringContext,
4504 bool isObjCIvarLookup,
4505 bool FindHidden);
4506
4507/// Check whether the declarations found for a typo correction are
4508/// visible. Set the correction's RequiresImport flag to true if none of the
4509/// declarations are visible, false otherwise.
4510static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
4511 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
4512
4513 for (/**/; DI != DE; ++DI)
4514 if (!LookupResult::isVisible(SemaRef, D: *DI))
4515 break;
4516 // No filtering needed if all decls are visible.
4517 if (DI == DE) {
4518 TC.setRequiresImport(false);
4519 return;
4520 }
4521
4522 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
4523 bool AnyVisibleDecls = !NewDecls.empty();
4524
4525 for (/**/; DI != DE; ++DI) {
4526 if (LookupResult::isVisible(SemaRef, D: *DI)) {
4527 if (!AnyVisibleDecls) {
4528 // Found a visible decl, discard all hidden ones.
4529 AnyVisibleDecls = true;
4530 NewDecls.clear();
4531 }
4532 NewDecls.push_back(Elt: *DI);
4533 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
4534 NewDecls.push_back(Elt: *DI);
4535 }
4536
4537 if (NewDecls.empty())
4538 TC = TypoCorrection();
4539 else {
4540 TC.setCorrectionDecls(NewDecls);
4541 TC.setRequiresImport(!AnyVisibleDecls);
4542 }
4543}
4544
4545// Fill the supplied vector with the IdentifierInfo pointers for each piece of
4546// the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
4547// fill the vector with the IdentifierInfo pointers for "foo" and "bar").
4548static void getNestedNameSpecifierIdentifiers(
4549 NestedNameSpecifier NNS,
4550 SmallVectorImpl<const IdentifierInfo *> &Identifiers) {
4551 switch (NNS.getKind()) {
4552 case NestedNameSpecifier::Kind::Null:
4553 Identifiers.clear();
4554 return;
4555
4556 case NestedNameSpecifier::Kind::Namespace: {
4557 auto [Namespace, Prefix] = NNS.getAsNamespaceAndPrefix();
4558 getNestedNameSpecifierIdentifiers(NNS: Prefix, Identifiers);
4559 if (const auto *NS = dyn_cast<NamespaceDecl>(Val: Namespace);
4560 NS && NS->isAnonymousNamespace())
4561 return;
4562 Identifiers.push_back(Elt: Namespace->getIdentifier());
4563 return;
4564 }
4565
4566 case NestedNameSpecifier::Kind::Type: {
4567 for (const Type *T = NNS.getAsType(); /**/; /**/) {
4568 switch (T->getTypeClass()) {
4569 case Type::DependentName: {
4570 auto *DT = cast<DependentNameType>(Val: T);
4571 getNestedNameSpecifierIdentifiers(NNS: DT->getQualifier(), Identifiers);
4572 Identifiers.push_back(Elt: DT->getIdentifier());
4573 return;
4574 }
4575 case Type::TemplateSpecialization: {
4576 TemplateName Name =
4577 cast<TemplateSpecializationType>(Val: T)->getTemplateName();
4578 if (const DependentTemplateName *DTN =
4579 Name.getAsDependentTemplateName()) {
4580 getNestedNameSpecifierIdentifiers(NNS: DTN->getQualifier(), Identifiers);
4581 if (const auto *II = DTN->getName().getIdentifier())
4582 Identifiers.push_back(Elt: II);
4583 return;
4584 }
4585 if (const QualifiedTemplateName *QTN =
4586 Name.getAsQualifiedTemplateName()) {
4587 getNestedNameSpecifierIdentifiers(NNS: QTN->getQualifier(), Identifiers);
4588 Name = QTN->getUnderlyingTemplate();
4589 }
4590 if (const auto *TD = Name.getAsTemplateDecl(/*IgnoreDeduced=*/true))
4591 Identifiers.push_back(Elt: TD->getIdentifier());
4592 return;
4593 }
4594 case Type::SubstTemplateTypeParm:
4595 T = cast<SubstTemplateTypeParmType>(Val: T)
4596 ->getReplacementType()
4597 .getTypePtr();
4598 continue;
4599 case Type::TemplateTypeParm:
4600 Identifiers.push_back(Elt: cast<TemplateTypeParmType>(Val: T)->getIdentifier());
4601 return;
4602 case Type::Decltype:
4603 return;
4604 case Type::Enum:
4605 case Type::Record:
4606 case Type::InjectedClassName: {
4607 auto *TT = cast<TagType>(Val: T);
4608 getNestedNameSpecifierIdentifiers(NNS: TT->getQualifier(), Identifiers);
4609 Identifiers.push_back(Elt: TT->getDecl()->getIdentifier());
4610 return;
4611 }
4612 case Type::Typedef: {
4613 auto *TT = cast<TypedefType>(Val: T);
4614 getNestedNameSpecifierIdentifiers(NNS: TT->getQualifier(), Identifiers);
4615 Identifiers.push_back(Elt: TT->getDecl()->getIdentifier());
4616 return;
4617 }
4618 case Type::Using: {
4619 auto *TT = cast<UsingType>(Val: T);
4620 getNestedNameSpecifierIdentifiers(NNS: TT->getQualifier(), Identifiers);
4621 Identifiers.push_back(Elt: TT->getDecl()->getIdentifier());
4622 return;
4623 }
4624 case Type::UnresolvedUsing: {
4625 auto *TT = cast<UnresolvedUsingType>(Val: T);
4626 getNestedNameSpecifierIdentifiers(NNS: TT->getQualifier(), Identifiers);
4627 Identifiers.push_back(Elt: TT->getDecl()->getIdentifier());
4628 return;
4629 }
4630 default:
4631 Identifiers.push_back(Elt: QualType(T, 0).getBaseTypeIdentifier());
4632 return;
4633 }
4634 }
4635 break;
4636 }
4637
4638 case NestedNameSpecifier::Kind::Global:
4639 case NestedNameSpecifier::Kind::MicrosoftSuper:
4640 return;
4641 }
4642}
4643
4644void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
4645 DeclContext *Ctx, bool InBaseClass) {
4646 // Don't consider hidden names for typo correction.
4647 if (Hiding)
4648 return;
4649
4650 // Only consider entities with identifiers for names, ignoring
4651 // special names (constructors, overloaded operators, selectors,
4652 // etc.).
4653 IdentifierInfo *Name = ND->getIdentifier();
4654 if (!Name)
4655 return;
4656
4657 // Only consider visible declarations and declarations from modules with
4658 // names that exactly match.
4659 if (!LookupResult::isVisible(SemaRef, D: ND) && Name != Typo)
4660 return;
4661
4662 FoundName(Name: Name->getName());
4663}
4664
4665void TypoCorrectionConsumer::FoundName(StringRef Name) {
4666 // Compute the edit distance between the typo and the name of this
4667 // entity, and add the identifier to the list of results.
4668 addName(Name, ND: nullptr);
4669}
4670
4671void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) {
4672 // Compute the edit distance between the typo and this keyword,
4673 // and add the keyword to the list of results.
4674 addName(Name: Keyword, /*ND=*/nullptr, /*NNS=*/std::nullopt, /*isKeyword=*/true);
4675}
4676
4677void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
4678 NestedNameSpecifier NNS, bool isKeyword) {
4679 // Use a simple length-based heuristic to determine the minimum possible
4680 // edit distance. If the minimum isn't good enough, bail out early.
4681 StringRef TypoStr = Typo->getName();
4682 unsigned MinED = abs(x: (int)Name.size() - (int)TypoStr.size());
4683 if (MinED && TypoStr.size() / MinED < 3)
4684 return;
4685
4686 // Compute an upper bound on the allowable edit distance, so that the
4687 // edit-distance algorithm can short-circuit.
4688 unsigned UpperBound = (TypoStr.size() + 2) / 3;
4689 unsigned ED = TypoStr.edit_distance(Other: Name, AllowReplacements: true, MaxEditDistance: UpperBound);
4690 if (ED > UpperBound) return;
4691
4692 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
4693 if (isKeyword) TC.makeKeyword();
4694 TC.setCorrectionRange(SS: nullptr, TypoName: Result.getLookupNameInfo());
4695 addCorrection(Correction: TC);
4696}
4697
4698static const unsigned MaxTypoDistanceResultSets = 5;
4699
4700void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) {
4701 StringRef TypoStr = Typo->getName();
4702 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
4703
4704 // For very short typos, ignore potential corrections that have a different
4705 // base identifier from the typo or which have a normalized edit distance
4706 // longer than the typo itself.
4707 if (TypoStr.size() < 3 &&
4708 (Name != TypoStr || Correction.getEditDistance(Normalized: true) > TypoStr.size()))
4709 return;
4710
4711 // If the correction is resolved but is not viable, ignore it.
4712 if (Correction.isResolved()) {
4713 checkCorrectionVisibility(SemaRef, TC&: Correction);
4714 if (!Correction || !isCandidateViable(CCC&: *CorrectionValidator, Candidate&: Correction))
4715 return;
4716 }
4717
4718 TypoResultList &CList =
4719 CorrectionResults[Correction.getEditDistance(Normalized: false)][Name];
4720
4721 if (!CList.empty() && !CList.back().isResolved())
4722 CList.pop_back();
4723 if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
4724 auto RI = llvm::find_if(Range&: CList, P: [NewND](const TypoCorrection &TypoCorr) {
4725 return TypoCorr.getCorrectionDecl() == NewND;
4726 });
4727 if (RI != CList.end()) {
4728 // The Correction refers to a decl already in the list. No insertion is
4729 // necessary and all further cases will return.
4730
4731 auto IsDeprecated = [](Decl *D) {
4732 while (D) {
4733 if (D->isDeprecated())
4734 return true;
4735 D = llvm::dyn_cast_or_null<NamespaceDecl>(Val: D->getDeclContext());
4736 }
4737 return false;
4738 };
4739
4740 // Prefer non deprecated Corrections over deprecated and only then
4741 // sort using an alphabetical order.
4742 std::pair<bool, std::string> NewKey = {
4743 IsDeprecated(Correction.getFoundDecl()),
4744 Correction.getAsString(LO: SemaRef.getLangOpts())};
4745
4746 std::pair<bool, std::string> PrevKey = {
4747 IsDeprecated(RI->getFoundDecl()),
4748 RI->getAsString(LO: SemaRef.getLangOpts())};
4749
4750 if (NewKey < PrevKey)
4751 *RI = Correction;
4752 return;
4753 }
4754 }
4755 if (CList.empty() || Correction.isResolved())
4756 CList.push_back(Elt: Correction);
4757
4758 while (CorrectionResults.size() > MaxTypoDistanceResultSets)
4759 CorrectionResults.erase(position: std::prev(x: CorrectionResults.end()));
4760}
4761
4762void TypoCorrectionConsumer::addNamespaces(
4763 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
4764 SearchNamespaces = true;
4765
4766 for (auto KNPair : KnownNamespaces)
4767 Namespaces.addNameSpecifier(Ctx: KNPair.first);
4768
4769 bool SSIsTemplate = false;
4770 if (NestedNameSpecifier NNS = (SS ? SS->getScopeRep() : std::nullopt)) {
4771 if (NNS.getKind() == NestedNameSpecifier::Kind::Type)
4772 SSIsTemplate =
4773 NNS.getAsType()->getTypeClass() == Type::TemplateSpecialization;
4774 }
4775 // Do not transform this into an iterator-based loop. The loop body can
4776 // trigger the creation of further types (through lazy deserialization) and
4777 // invalid iterators into this list.
4778 auto &Types = SemaRef.getASTContext().getTypes();
4779 for (unsigned I = 0; I != Types.size(); ++I) {
4780 const auto *TI = Types[I];
4781 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
4782 CD = CD->getCanonicalDecl();
4783 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
4784 !CD->isUnion() && CD->getIdentifier() &&
4785 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(Val: CD)) &&
4786 (CD->isBeingDefined() || CD->isCompleteDefinition()))
4787 Namespaces.addNameSpecifier(Ctx: CD);
4788 }
4789 }
4790}
4791
4792const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() {
4793 if (++CurrentTCIndex < ValidatedCorrections.size())
4794 return ValidatedCorrections[CurrentTCIndex];
4795
4796 CurrentTCIndex = ValidatedCorrections.size();
4797 while (!CorrectionResults.empty()) {
4798 auto DI = CorrectionResults.begin();
4799 if (DI->second.empty()) {
4800 CorrectionResults.erase(position: DI);
4801 continue;
4802 }
4803
4804 auto RI = DI->second.begin();
4805 if (RI->second.empty()) {
4806 DI->second.erase(I: RI);
4807 performQualifiedLookups();
4808 continue;
4809 }
4810
4811 TypoCorrection TC = RI->second.pop_back_val();
4812 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(Candidate&: TC)) {
4813 ValidatedCorrections.push_back(Elt: TC);
4814 return ValidatedCorrections[CurrentTCIndex];
4815 }
4816 }
4817 return ValidatedCorrections[0]; // The empty correction.
4818}
4819
4820bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
4821 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
4822 DeclContext *TempMemberContext = MemberContext;
4823 CXXScopeSpec *TempSS = SS.get();
4824retry_lookup:
4825 LookupPotentialTypoResult(SemaRef, Res&: Result, Name, S, SS: TempSS, MemberContext: TempMemberContext,
4826 EnteringContext,
4827 isObjCIvarLookup: CorrectionValidator->IsObjCIvarLookup,
4828 FindHidden: Name == Typo && !Candidate.WillReplaceSpecifier());
4829 switch (Result.getResultKind()) {
4830 case LookupResultKind::NotFound:
4831 case LookupResultKind::NotFoundInCurrentInstantiation:
4832 case LookupResultKind::FoundUnresolvedValue:
4833 if (TempSS) {
4834 // Immediately retry the lookup without the given CXXScopeSpec
4835 TempSS = nullptr;
4836 Candidate.WillReplaceSpecifier(ForceReplacement: true);
4837 goto retry_lookup;
4838 }
4839 if (TempMemberContext) {
4840 if (SS && !TempSS)
4841 TempSS = SS.get();
4842 TempMemberContext = nullptr;
4843 goto retry_lookup;
4844 }
4845 if (SearchNamespaces)
4846 QualifiedResults.push_back(Elt: Candidate);
4847 break;
4848
4849 case LookupResultKind::Ambiguous:
4850 // We don't deal with ambiguities.
4851 break;
4852
4853 case LookupResultKind::Found:
4854 case LookupResultKind::FoundOverloaded:
4855 // Store all of the Decls for overloaded symbols
4856 for (auto *TRD : Result)
4857 Candidate.addCorrectionDecl(CDecl: TRD);
4858 checkCorrectionVisibility(SemaRef, TC&: Candidate);
4859 if (!isCandidateViable(CCC&: *CorrectionValidator, Candidate)) {
4860 if (SearchNamespaces)
4861 QualifiedResults.push_back(Elt: Candidate);
4862 break;
4863 }
4864 Candidate.setCorrectionRange(SS: SS.get(), TypoName: Result.getLookupNameInfo());
4865 return true;
4866 }
4867 return false;
4868}
4869
4870void TypoCorrectionConsumer::performQualifiedLookups() {
4871 unsigned TypoLen = Typo->getName().size();
4872 for (const TypoCorrection &QR : QualifiedResults) {
4873 for (const auto &NSI : Namespaces) {
4874 DeclContext *Ctx = NSI.DeclCtx;
4875 CXXRecordDecl *NamingClass = NSI.NameSpecifier.getAsRecordDecl();
4876
4877 // If the current NestedNameSpecifier refers to a class and the
4878 // current correction candidate is the name of that class, then skip
4879 // it as it is unlikely a qualified version of the class' constructor
4880 // is an appropriate correction.
4881 if (NamingClass &&
4882 NamingClass->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
4883 continue;
4884
4885 TypoCorrection TC(QR);
4886 TC.ClearCorrectionDecls();
4887 TC.setCorrectionSpecifier(NSI.NameSpecifier);
4888 TC.setQualifierDistance(NSI.EditDistance);
4889 TC.setCallbackDistance(0); // Reset the callback distance
4890
4891 // If the current correction candidate and namespace combination are
4892 // too far away from the original typo based on the normalized edit
4893 // distance, then skip performing a qualified name lookup.
4894 unsigned TmpED = TC.getEditDistance(Normalized: true);
4895 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4896 TypoLen / TmpED < 3)
4897 continue;
4898
4899 Result.clear();
4900 Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4901 if (!SemaRef.LookupQualifiedName(R&: Result, LookupCtx: Ctx))
4902 continue;
4903
4904 // Any corrections added below will be validated in subsequent
4905 // iterations of the main while() loop over the Consumer's contents.
4906 switch (Result.getResultKind()) {
4907 case LookupResultKind::Found:
4908 case LookupResultKind::FoundOverloaded: {
4909 if (SS && SS->isValid()) {
4910 std::string NewQualified = TC.getAsString(LO: SemaRef.getLangOpts());
4911 std::string OldQualified;
4912 llvm::raw_string_ostream OldOStream(OldQualified);
4913 SS->getScopeRep().print(OS&: OldOStream, Policy: SemaRef.getPrintingPolicy());
4914 OldOStream << Typo->getName();
4915 // If correction candidate would be an identical written qualified
4916 // identifier, then the existing CXXScopeSpec probably included a
4917 // typedef that didn't get accounted for properly.
4918 if (OldOStream.str() == NewQualified)
4919 break;
4920 }
4921 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4922 TRD != TRDEnd; ++TRD) {
4923 if (SemaRef.CheckMemberAccess(UseLoc: TC.getCorrectionRange().getBegin(),
4924 NamingClass,
4925 Found: TRD.getPair()) == Sema::AR_accessible)
4926 TC.addCorrectionDecl(CDecl: *TRD);
4927 }
4928 if (TC.isResolved()) {
4929 TC.setCorrectionRange(SS: SS.get(), TypoName: Result.getLookupNameInfo());
4930 addCorrection(Correction: TC);
4931 }
4932 break;
4933 }
4934 case LookupResultKind::NotFound:
4935 case LookupResultKind::NotFoundInCurrentInstantiation:
4936 case LookupResultKind::Ambiguous:
4937 case LookupResultKind::FoundUnresolvedValue:
4938 break;
4939 }
4940 }
4941 }
4942 QualifiedResults.clear();
4943}
4944
4945TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4946 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4947 : Context(Context), CurContextChain(buildContextChain(Start: CurContext)) {
4948 if (NestedNameSpecifier NNS =
4949 CurScopeSpec ? CurScopeSpec->getScopeRep() : std::nullopt) {
4950 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4951 NNS.print(OS&: SpecifierOStream, Policy: Context.getPrintingPolicy());
4952
4953 getNestedNameSpecifierIdentifiers(NNS, Identifiers&: CurNameSpecifierIdentifiers);
4954 }
4955 // Build the list of identifiers that would be used for an absolute
4956 // (from the global context) NestedNameSpecifier referring to the current
4957 // context.
4958 for (DeclContext *C : llvm::reverse(C&: CurContextChain)) {
4959 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(Val: C))
4960 CurContextIdentifiers.push_back(Elt: ND->getIdentifier());
4961 }
4962
4963 // Add the global context as a NestedNameSpecifier
4964 SpecifierInfo SI = {.DeclCtx: cast<DeclContext>(Val: Context.getTranslationUnitDecl()),
4965 .NameSpecifier: NestedNameSpecifier::getGlobal(), .EditDistance: 1};
4966 DistanceMap[1].push_back(Elt: SI);
4967}
4968
4969auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
4970 DeclContext *Start) -> DeclContextList {
4971 assert(Start && "Building a context chain from a null context");
4972 DeclContextList Chain;
4973 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
4974 DC = DC->getLookupParent()) {
4975 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(Val: DC);
4976 if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
4977 !(ND && ND->isAnonymousNamespace()))
4978 Chain.push_back(Elt: DC->getPrimaryContext());
4979 }
4980 return Chain;
4981}
4982
4983unsigned
4984TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
4985 DeclContextList &DeclChain, NestedNameSpecifier &NNS) {
4986 unsigned NumSpecifiers = 0;
4987 for (DeclContext *C : llvm::reverse(C&: DeclChain)) {
4988 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(Val: C)) {
4989 NNS = NestedNameSpecifier(Context, ND, NNS);
4990 ++NumSpecifiers;
4991 } else if (auto *RD = dyn_cast_or_null<RecordDecl>(Val: C)) {
4992 QualType T = Context.getTagType(Keyword: ElaboratedTypeKeyword::None, Qualifier: NNS, TD: RD,
4993 /*OwnsTag=*/false);
4994 NNS = NestedNameSpecifier(T.getTypePtr());
4995 ++NumSpecifiers;
4996 }
4997 }
4998 return NumSpecifiers;
4999}
5000
5001void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
5002 DeclContext *Ctx) {
5003 NestedNameSpecifier NNS = std::nullopt;
5004 unsigned NumSpecifiers = 0;
5005 DeclContextList NamespaceDeclChain(buildContextChain(Start: Ctx));
5006 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
5007
5008 // Eliminate common elements from the two DeclContext chains.
5009 for (DeclContext *C : llvm::reverse(C&: CurContextChain)) {
5010 if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C)
5011 break;
5012 NamespaceDeclChain.pop_back();
5013 }
5014
5015 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
5016 NumSpecifiers = buildNestedNameSpecifier(DeclChain&: NamespaceDeclChain, NNS);
5017
5018 // Add an explicit leading '::' specifier if needed.
5019 if (NamespaceDeclChain.empty()) {
5020 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
5021 NNS = NestedNameSpecifier::getGlobal();
5022 NumSpecifiers =
5023 buildNestedNameSpecifier(DeclChain&: FullNamespaceDeclChain, NNS);
5024 } else if (NamedDecl *ND =
5025 dyn_cast_or_null<NamedDecl>(Val: NamespaceDeclChain.back())) {
5026 IdentifierInfo *Name = ND->getIdentifier();
5027 bool SameNameSpecifier = false;
5028 if (llvm::is_contained(Range&: CurNameSpecifierIdentifiers, Element: Name)) {
5029 std::string NewNameSpecifier;
5030 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
5031 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
5032 getNestedNameSpecifierIdentifiers(NNS, Identifiers&: NewNameSpecifierIdentifiers);
5033 NNS.print(OS&: SpecifierOStream, Policy: Context.getPrintingPolicy());
5034 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
5035 }
5036 if (SameNameSpecifier || llvm::is_contained(Range&: CurContextIdentifiers, Element: Name)) {
5037 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
5038 NNS = NestedNameSpecifier::getGlobal();
5039 NumSpecifiers =
5040 buildNestedNameSpecifier(DeclChain&: FullNamespaceDeclChain, NNS);
5041 }
5042 }
5043
5044 // If the built NestedNameSpecifier would be replacing an existing
5045 // NestedNameSpecifier, use the number of component identifiers that
5046 // would need to be changed as the edit distance instead of the number
5047 // of components in the built NestedNameSpecifier.
5048 if (NNS && !CurNameSpecifierIdentifiers.empty()) {
5049 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
5050 getNestedNameSpecifierIdentifiers(NNS, Identifiers&: NewNameSpecifierIdentifiers);
5051 NumSpecifiers =
5052 llvm::ComputeEditDistance(FromArray: llvm::ArrayRef(CurNameSpecifierIdentifiers),
5053 ToArray: llvm::ArrayRef(NewNameSpecifierIdentifiers));
5054 }
5055
5056 SpecifierInfo SI = {.DeclCtx: Ctx, .NameSpecifier: NNS, .EditDistance: NumSpecifiers};
5057 DistanceMap[NumSpecifiers].push_back(Elt: SI);
5058}
5059
5060/// Perform name lookup for a possible result for typo correction.
5061static void LookupPotentialTypoResult(Sema &SemaRef,
5062 LookupResult &Res,
5063 IdentifierInfo *Name,
5064 Scope *S, CXXScopeSpec *SS,
5065 DeclContext *MemberContext,
5066 bool EnteringContext,
5067 bool isObjCIvarLookup,
5068 bool FindHidden) {
5069 Res.suppressDiagnostics();
5070 Res.clear();
5071 Res.setLookupName(Name);
5072 Res.setAllowHidden(FindHidden);
5073 if (MemberContext) {
5074 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(Val: MemberContext)) {
5075 if (isObjCIvarLookup) {
5076 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(IVarName: Name)) {
5077 Res.addDecl(D: Ivar);
5078 Res.resolveKind();
5079 return;
5080 }
5081 }
5082
5083 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(
5084 PropertyId: Name, QueryKind: ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
5085 Res.addDecl(D: Prop);
5086 Res.resolveKind();
5087 return;
5088 }
5089 }
5090
5091 SemaRef.LookupQualifiedName(R&: Res, LookupCtx: MemberContext);
5092 return;
5093 }
5094
5095 SemaRef.LookupParsedName(R&: Res, S, SS,
5096 /*ObjectType=*/QualType(),
5097 /*AllowBuiltinCreation=*/false, EnteringContext);
5098
5099 // Fake ivar lookup; this should really be part of
5100 // LookupParsedName.
5101 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
5102 if (Method->isInstanceMethod() && Method->getClassInterface() &&
5103 (Res.empty() ||
5104 (Res.isSingleResult() &&
5105 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) {
5106 if (ObjCIvarDecl *IV
5107 = Method->getClassInterface()->lookupInstanceVariable(IVarName: Name)) {
5108 Res.addDecl(D: IV);
5109 Res.resolveKind();
5110 }
5111 }
5112 }
5113}
5114
5115/// Add keywords to the consumer as possible typo corrections.
5116static void AddKeywordsToConsumer(Sema &SemaRef,
5117 TypoCorrectionConsumer &Consumer,
5118 Scope *S, CorrectionCandidateCallback &CCC,
5119 bool AfterNestedNameSpecifier) {
5120 if (AfterNestedNameSpecifier) {
5121 // For 'X::', we know exactly which keywords can appear next.
5122 Consumer.addKeywordResult(Keyword: "template");
5123 if (CCC.WantExpressionKeywords)
5124 Consumer.addKeywordResult(Keyword: "operator");
5125 return;
5126 }
5127
5128 if (CCC.WantObjCSuper)
5129 Consumer.addKeywordResult(Keyword: "super");
5130
5131 if (CCC.WantTypeSpecifiers) {
5132 // Add type-specifier keywords to the set of results.
5133 static const char *const CTypeSpecs[] = {
5134 "char", "const", "double", "enum", "float", "int", "long", "short",
5135 "signed", "struct", "union", "unsigned", "void", "volatile",
5136 "_Complex",
5137 // storage-specifiers as well
5138 "extern", "inline", "static", "typedef"
5139 };
5140
5141 for (const auto *CTS : CTypeSpecs)
5142 Consumer.addKeywordResult(Keyword: CTS);
5143
5144 if (SemaRef.getLangOpts().C99 && !SemaRef.getLangOpts().C2y)
5145 Consumer.addKeywordResult(Keyword: "_Imaginary");
5146
5147 if (SemaRef.getLangOpts().C99)
5148 Consumer.addKeywordResult(Keyword: "restrict");
5149 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
5150 Consumer.addKeywordResult(Keyword: "bool");
5151 else if (SemaRef.getLangOpts().C99)
5152 Consumer.addKeywordResult(Keyword: "_Bool");
5153
5154 if (SemaRef.getLangOpts().CPlusPlus) {
5155 Consumer.addKeywordResult(Keyword: "class");
5156 Consumer.addKeywordResult(Keyword: "typename");
5157 Consumer.addKeywordResult(Keyword: "wchar_t");
5158
5159 if (SemaRef.getLangOpts().CPlusPlus11) {
5160 Consumer.addKeywordResult(Keyword: "char16_t");
5161 Consumer.addKeywordResult(Keyword: "char32_t");
5162 Consumer.addKeywordResult(Keyword: "constexpr");
5163 Consumer.addKeywordResult(Keyword: "decltype");
5164 Consumer.addKeywordResult(Keyword: "thread_local");
5165 }
5166 }
5167
5168 if (SemaRef.getLangOpts().GNUKeywords)
5169 Consumer.addKeywordResult(Keyword: "typeof");
5170 } else if (CCC.WantFunctionLikeCasts) {
5171 static const char *const CastableTypeSpecs[] = {
5172 "char", "double", "float", "int", "long", "short",
5173 "signed", "unsigned", "void"
5174 };
5175 for (auto *kw : CastableTypeSpecs)
5176 Consumer.addKeywordResult(Keyword: kw);
5177 }
5178
5179 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
5180 Consumer.addKeywordResult(Keyword: "const_cast");
5181 Consumer.addKeywordResult(Keyword: "dynamic_cast");
5182 Consumer.addKeywordResult(Keyword: "reinterpret_cast");
5183 Consumer.addKeywordResult(Keyword: "static_cast");
5184 }
5185
5186 if (CCC.WantExpressionKeywords) {
5187 Consumer.addKeywordResult(Keyword: "sizeof");
5188 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
5189 Consumer.addKeywordResult(Keyword: "false");
5190 Consumer.addKeywordResult(Keyword: "true");
5191 }
5192
5193 if (SemaRef.getLangOpts().CPlusPlus) {
5194 static const char *const CXXExprs[] = {
5195 "delete", "new", "operator", "throw", "typeid"
5196 };
5197 for (const auto *CE : CXXExprs)
5198 Consumer.addKeywordResult(Keyword: CE);
5199
5200 if (isa<CXXMethodDecl>(Val: SemaRef.CurContext) &&
5201 cast<CXXMethodDecl>(Val: SemaRef.CurContext)->isInstance())
5202 Consumer.addKeywordResult(Keyword: "this");
5203
5204 if (SemaRef.getLangOpts().CPlusPlus11) {
5205 Consumer.addKeywordResult(Keyword: "alignof");
5206 Consumer.addKeywordResult(Keyword: "nullptr");
5207 }
5208 }
5209
5210 if (SemaRef.getLangOpts().C11) {
5211 // FIXME: We should not suggest _Alignof if the alignof macro
5212 // is present.
5213 Consumer.addKeywordResult(Keyword: "_Alignof");
5214 }
5215 }
5216
5217 if (CCC.WantRemainingKeywords) {
5218 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
5219 // Statements.
5220 static const char *const CStmts[] = {
5221 "do", "else", "for", "goto", "if", "return", "switch", "while" };
5222 for (const auto *CS : CStmts)
5223 Consumer.addKeywordResult(Keyword: CS);
5224
5225 if (SemaRef.getLangOpts().CPlusPlus) {
5226 Consumer.addKeywordResult(Keyword: "catch");
5227 Consumer.addKeywordResult(Keyword: "try");
5228 }
5229
5230 if (S && S->getBreakParent())
5231 Consumer.addKeywordResult(Keyword: "break");
5232
5233 if (S && S->getContinueParent())
5234 Consumer.addKeywordResult(Keyword: "continue");
5235
5236 if (SemaRef.getCurFunction() &&
5237 !SemaRef.getCurFunction()->SwitchStack.empty()) {
5238 Consumer.addKeywordResult(Keyword: "case");
5239 Consumer.addKeywordResult(Keyword: "default");
5240 }
5241 } else {
5242 if (SemaRef.getLangOpts().CPlusPlus) {
5243 Consumer.addKeywordResult(Keyword: "namespace");
5244 Consumer.addKeywordResult(Keyword: "template");
5245 }
5246
5247 if (S && S->isClassScope()) {
5248 Consumer.addKeywordResult(Keyword: "explicit");
5249 Consumer.addKeywordResult(Keyword: "friend");
5250 Consumer.addKeywordResult(Keyword: "mutable");
5251 Consumer.addKeywordResult(Keyword: "private");
5252 Consumer.addKeywordResult(Keyword: "protected");
5253 Consumer.addKeywordResult(Keyword: "public");
5254 Consumer.addKeywordResult(Keyword: "virtual");
5255 }
5256 }
5257
5258 if (SemaRef.getLangOpts().CPlusPlus) {
5259 Consumer.addKeywordResult(Keyword: "using");
5260
5261 if (SemaRef.getLangOpts().CPlusPlus11)
5262 Consumer.addKeywordResult(Keyword: "static_assert");
5263 }
5264 }
5265}
5266
5267std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
5268 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
5269 Scope *S, CXXScopeSpec *SS, CorrectionCandidateCallback &CCC,
5270 DeclContext *MemberContext, bool EnteringContext,
5271 const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
5272
5273 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
5274 DisableTypoCorrection)
5275 return nullptr;
5276
5277 // In Microsoft mode, don't perform typo correction in a template member
5278 // function dependent context because it interferes with the "lookup into
5279 // dependent bases of class templates" feature.
5280 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
5281 isa<CXXMethodDecl>(Val: CurContext))
5282 return nullptr;
5283
5284 // We only attempt to correct typos for identifiers.
5285 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
5286 if (!Typo)
5287 return nullptr;
5288
5289 // If the scope specifier itself was invalid, don't try to correct
5290 // typos.
5291 if (SS && SS->isInvalid())
5292 return nullptr;
5293
5294 // Never try to correct typos during any kind of code synthesis.
5295 if (!CodeSynthesisContexts.empty())
5296 return nullptr;
5297
5298 // Don't try to correct 'super'.
5299 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
5300 return nullptr;
5301
5302 // Abort if typo correction already failed for this specific typo.
5303 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Val: Typo);
5304 if (locs != TypoCorrectionFailures.end() &&
5305 locs->second.count(V: TypoName.getLoc()))
5306 return nullptr;
5307
5308 // Don't try to correct the identifier "vector" when in AltiVec mode.
5309 // TODO: Figure out why typo correction misbehaves in this case, fix it, and
5310 // remove this workaround.
5311 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr(Str: "vector"))
5312 return nullptr;
5313
5314 // Provide a stop gap for files that are just seriously broken. Trying
5315 // to correct all typos can turn into a HUGE performance penalty, causing
5316 // some files to take minutes to get rejected by the parser.
5317 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
5318 if (Limit && TyposCorrected >= Limit)
5319 return nullptr;
5320 ++TyposCorrected;
5321
5322 // If we're handling a missing symbol error, using modules, and the
5323 // special search all modules option is used, look for a missing import.
5324 if (ErrorRecovery && getLangOpts().Modules &&
5325 getLangOpts().ModulesSearchAll) {
5326 // The following has the side effect of loading the missing module.
5327 getModuleLoader().lookupMissingImports(Name: Typo->getName(),
5328 TriggerLoc: TypoName.getBeginLoc());
5329 }
5330
5331 // Extend the lifetime of the callback. We delayed this until here
5332 // to avoid allocations in the hot path (which is where no typo correction
5333 // occurs). Note that CorrectionCandidateCallback is polymorphic and
5334 // initially stack-allocated.
5335 std::unique_ptr<CorrectionCandidateCallback> ClonedCCC = CCC.clone();
5336 auto Consumer = std::make_unique<TypoCorrectionConsumer>(
5337 args&: *this, args: TypoName, args&: LookupKind, args&: S, args&: SS, args: std::move(ClonedCCC), args&: MemberContext,
5338 args&: EnteringContext);
5339
5340 // Perform name lookup to find visible, similarly-named entities.
5341 bool IsUnqualifiedLookup = false;
5342 DeclContext *QualifiedDC = MemberContext;
5343 if (MemberContext) {
5344 LookupVisibleDecls(Ctx: MemberContext, Kind: LookupKind, Consumer&: *Consumer);
5345
5346 // Look in qualified interfaces.
5347 if (OPT) {
5348 for (auto *I : OPT->quals())
5349 LookupVisibleDecls(Ctx: I, Kind: LookupKind, Consumer&: *Consumer);
5350 }
5351 } else if (SS && SS->isSet()) {
5352 QualifiedDC = computeDeclContext(SS: *SS, EnteringContext);
5353 if (!QualifiedDC)
5354 return nullptr;
5355
5356 LookupVisibleDecls(Ctx: QualifiedDC, Kind: LookupKind, Consumer&: *Consumer);
5357 } else {
5358 IsUnqualifiedLookup = true;
5359 }
5360
5361 // Determine whether we are going to search in the various namespaces for
5362 // corrections.
5363 bool SearchNamespaces
5364 = getLangOpts().CPlusPlus &&
5365 (IsUnqualifiedLookup || (SS && SS->isSet()));
5366
5367 if (IsUnqualifiedLookup || SearchNamespaces) {
5368 // For unqualified lookup, look through all of the names that we have
5369 // seen in this translation unit.
5370 // FIXME: Re-add the ability to skip very unlikely potential corrections.
5371 for (const auto &I : Context.Idents)
5372 Consumer->FoundName(Name: I.getKey());
5373
5374 // Walk through identifiers in external identifier sources.
5375 // FIXME: Re-add the ability to skip very unlikely potential corrections.
5376 if (IdentifierInfoLookup *External
5377 = Context.Idents.getExternalIdentifierLookup()) {
5378 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
5379 do {
5380 StringRef Name = Iter->Next();
5381 if (Name.empty())
5382 break;
5383
5384 Consumer->FoundName(Name);
5385 } while (true);
5386 }
5387 }
5388
5389 AddKeywordsToConsumer(SemaRef&: *this, Consumer&: *Consumer, S,
5390 CCC&: *Consumer->getCorrectionValidator(),
5391 AfterNestedNameSpecifier: SS && SS->isNotEmpty());
5392
5393 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
5394 // to search those namespaces.
5395 if (SearchNamespaces) {
5396 // Load any externally-known namespaces.
5397 if (ExternalSource && !LoadedExternalKnownNamespaces) {
5398 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
5399 LoadedExternalKnownNamespaces = true;
5400 ExternalSource->ReadKnownNamespaces(Namespaces&: ExternalKnownNamespaces);
5401 for (auto *N : ExternalKnownNamespaces)
5402 KnownNamespaces[N] = true;
5403 }
5404
5405 Consumer->addNamespaces(KnownNamespaces);
5406 }
5407
5408 return Consumer;
5409}
5410
5411TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
5412 Sema::LookupNameKind LookupKind,
5413 Scope *S, CXXScopeSpec *SS,
5414 CorrectionCandidateCallback &CCC,
5415 CorrectTypoKind Mode,
5416 DeclContext *MemberContext,
5417 bool EnteringContext,
5418 const ObjCObjectPointerType *OPT,
5419 bool RecordFailure) {
5420 // Always let the ExternalSource have the first chance at correction, even
5421 // if we would otherwise have given up.
5422 if (ExternalSource) {
5423 if (TypoCorrection Correction =
5424 ExternalSource->CorrectTypo(Typo: TypoName, LookupKind, S, SS, CCC,
5425 MemberContext, EnteringContext, OPT))
5426 return Correction;
5427 }
5428
5429 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
5430 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
5431 // some instances of CTC_Unknown, while WantRemainingKeywords is true
5432 // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
5433 bool ObjCMessageReceiver = CCC.WantObjCSuper && !CCC.WantRemainingKeywords;
5434
5435 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
5436 auto Consumer = makeTypoCorrectionConsumer(
5437 TypoName, LookupKind, S, SS, CCC, MemberContext, EnteringContext, OPT,
5438 ErrorRecovery: Mode == CorrectTypoKind::ErrorRecovery);
5439
5440 if (!Consumer)
5441 return TypoCorrection();
5442
5443 // If we haven't found anything, we're done.
5444 if (Consumer->empty())
5445 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure);
5446
5447 // Make sure the best edit distance (prior to adding any namespace qualifiers)
5448 // is not more that about a third of the length of the typo's identifier.
5449 unsigned ED = Consumer->getBestEditDistance(Normalized: true);
5450 unsigned TypoLen = Typo->getName().size();
5451 if (ED > 0 && TypoLen / ED < 3)
5452 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure);
5453
5454 TypoCorrection BestTC = Consumer->getNextCorrection();
5455 TypoCorrection SecondBestTC = Consumer->getNextCorrection();
5456 if (!BestTC)
5457 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure);
5458
5459 ED = BestTC.getEditDistance();
5460
5461 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
5462 // If this was an unqualified lookup and we believe the callback
5463 // object wouldn't have filtered out possible corrections, note
5464 // that no correction was found.
5465 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure);
5466 }
5467
5468 // If only a single name remains, return that result.
5469 if (!SecondBestTC ||
5470 SecondBestTC.getEditDistance(Normalized: false) > BestTC.getEditDistance(Normalized: false)) {
5471 const TypoCorrection &Result = BestTC;
5472
5473 // Don't correct to a keyword that's the same as the typo; the keyword
5474 // wasn't actually in scope.
5475 if (ED == 0 && Result.isKeyword())
5476 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure);
5477
5478 TypoCorrection TC = Result;
5479 TC.setCorrectionRange(SS, TypoName);
5480 checkCorrectionVisibility(SemaRef&: *this, TC);
5481 return TC;
5482 } else if (SecondBestTC && ObjCMessageReceiver) {
5483 // Prefer 'super' when we're completing in a message-receiver
5484 // context.
5485
5486 if (BestTC.getCorrection().getAsString() != "super") {
5487 if (SecondBestTC.getCorrection().getAsString() == "super")
5488 BestTC = SecondBestTC;
5489 else if ((*Consumer)["super"].front().isKeyword())
5490 BestTC = (*Consumer)["super"].front();
5491 }
5492 // Don't correct to a keyword that's the same as the typo; the keyword
5493 // wasn't actually in scope.
5494 if (BestTC.getEditDistance() == 0 ||
5495 BestTC.getCorrection().getAsString() != "super")
5496 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure);
5497
5498 BestTC.setCorrectionRange(SS, TypoName);
5499 return BestTC;
5500 }
5501
5502 // Record the failure's location if needed and return an empty correction. If
5503 // this was an unqualified lookup and we believe the callback object did not
5504 // filter out possible corrections, also cache the failure for the typo.
5505 return FailedCorrection(Typo, TypoLoc: TypoName.getLoc(), RecordFailure: RecordFailure && !SecondBestTC);
5506}
5507
5508void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) {
5509 if (!CDecl) return;
5510
5511 if (isKeyword())
5512 CorrectionDecls.clear();
5513
5514 CorrectionDecls.push_back(Elt: CDecl);
5515
5516 if (!CorrectionName)
5517 CorrectionName = CDecl->getDeclName();
5518}
5519
5520std::string TypoCorrection::getAsString(const LangOptions &LO) const {
5521 if (CorrectionNameSpec) {
5522 std::string tmpBuffer;
5523 llvm::raw_string_ostream PrefixOStream(tmpBuffer);
5524 CorrectionNameSpec.print(OS&: PrefixOStream, Policy: PrintingPolicy(LO));
5525 PrefixOStream << CorrectionName;
5526 return PrefixOStream.str();
5527 }
5528
5529 return CorrectionName.getAsString();
5530}
5531
5532bool CorrectionCandidateCallback::ValidateCandidate(
5533 const TypoCorrection &candidate) {
5534 if (!candidate.isResolved())
5535 return true;
5536
5537 if (candidate.isKeyword())
5538 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
5539 WantRemainingKeywords || WantObjCSuper;
5540
5541 bool HasNonType = false;
5542 bool HasStaticMethod = false;
5543 bool HasNonStaticMethod = false;
5544 for (Decl *D : candidate) {
5545 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(Val: D))
5546 D = FTD->getTemplatedDecl();
5547 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Val: D)) {
5548 if (Method->isStatic())
5549 HasStaticMethod = true;
5550 else
5551 HasNonStaticMethod = true;
5552 }
5553 if (!isa<TypeDecl>(Val: D))
5554 HasNonType = true;
5555 }
5556
5557 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
5558 !candidate.getCorrectionSpecifier())
5559 return false;
5560
5561 return WantTypeSpecifiers || HasNonType;
5562}
5563
5564FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs,
5565 bool HasExplicitTemplateArgs,
5566 MemberExpr *ME)
5567 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
5568 CurContext(SemaRef.CurContext), MemberFn(ME) {
5569 WantTypeSpecifiers = false;
5570 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus &&
5571 !HasExplicitTemplateArgs && NumArgs == 1;
5572 WantCXXNamedCasts = HasExplicitTemplateArgs && NumArgs == 1;
5573 WantRemainingKeywords = false;
5574}
5575
5576bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) {
5577 if (!candidate.getCorrectionDecl())
5578 return candidate.isKeyword();
5579
5580 for (auto *C : candidate) {
5581 FunctionDecl *FD = nullptr;
5582 NamedDecl *ND = C->getUnderlyingDecl();
5583 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(Val: ND))
5584 FD = FTD->getTemplatedDecl();
5585 if (!HasExplicitTemplateArgs && !FD) {
5586 if (!(FD = dyn_cast<FunctionDecl>(Val: ND)) && isa<ValueDecl>(Val: ND)) {
5587 // If the Decl is neither a function nor a template function,
5588 // determine if it is a pointer or reference to a function. If so,
5589 // check against the number of arguments expected for the pointee.
5590 QualType ValType = cast<ValueDecl>(Val: ND)->getType();
5591 if (ValType.isNull())
5592 continue;
5593 if (ValType->isAnyPointerType() || ValType->isReferenceType())
5594 ValType = ValType->getPointeeType();
5595 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
5596 if (FPT->getNumParams() == NumArgs)
5597 return true;
5598 }
5599 }
5600
5601 // A typo for a function-style cast can look like a function call in C++.
5602 if ((HasExplicitTemplateArgs ? getAsTypeTemplateDecl(D: ND) != nullptr
5603 : isa<TypeDecl>(Val: ND)) &&
5604 CurContext->getParentASTContext().getLangOpts().CPlusPlus)
5605 // Only a class or class template can take two or more arguments.
5606 return NumArgs <= 1 || HasExplicitTemplateArgs || isa<CXXRecordDecl>(Val: ND);
5607
5608 // Skip the current candidate if it is not a FunctionDecl or does not accept
5609 // the current number of arguments.
5610 if (!FD || !(FD->getNumParams() >= NumArgs &&
5611 FD->getMinRequiredArguments() <= NumArgs))
5612 continue;
5613
5614 // If the current candidate is a non-static C++ method, skip the candidate
5615 // unless the method being corrected--or the current DeclContext, if the
5616 // function being corrected is not a method--is a method in the same class
5617 // or a descendent class of the candidate's parent class.
5618 if (const auto *MD = dyn_cast<CXXMethodDecl>(Val: FD)) {
5619 if (MemberFn || !MD->isStatic()) {
5620 const auto *CurMD =
5621 MemberFn
5622 ? dyn_cast_if_present<CXXMethodDecl>(Val: MemberFn->getMemberDecl())
5623 : dyn_cast_if_present<CXXMethodDecl>(Val: CurContext);
5624 const CXXRecordDecl *CurRD =
5625 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
5626 const CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
5627 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(Base: RD)))
5628 continue;
5629 }
5630 }
5631 return true;
5632 }
5633 return false;
5634}
5635
5636void Sema::diagnoseTypo(const TypoCorrection &Correction,
5637 const PartialDiagnostic &TypoDiag,
5638 bool ErrorRecovery) {
5639 diagnoseTypo(Correction, TypoDiag, PrevNote: PDiag(DiagID: diag::note_previous_decl),
5640 ErrorRecovery);
5641}
5642
5643/// Find which declaration we should import to provide the definition of
5644/// the given declaration.
5645static const NamedDecl *getDefinitionToImport(const NamedDecl *D) {
5646 if (const auto *VD = dyn_cast<VarDecl>(Val: D))
5647 return VD->getDefinition();
5648 if (const auto *FD = dyn_cast<FunctionDecl>(Val: D))
5649 return FD->getDefinition();
5650 if (const auto *TD = dyn_cast<TagDecl>(Val: D))
5651 return TD->getDefinition();
5652 if (const auto *ID = dyn_cast<ObjCInterfaceDecl>(Val: D))
5653 return ID->getDefinition();
5654 if (const auto *PD = dyn_cast<ObjCProtocolDecl>(Val: D))
5655 return PD->getDefinition();
5656 if (const auto *TD = dyn_cast<TemplateDecl>(Val: D))
5657 if (const NamedDecl *TTD = TD->getTemplatedDecl())
5658 return getDefinitionToImport(D: TTD);
5659 return nullptr;
5660}
5661
5662void Sema::diagnoseMissingImport(SourceLocation Loc, const NamedDecl *Decl,
5663 MissingImportKind MIK, bool Recover) {
5664 // Suggest importing a module providing the definition of this entity, if
5665 // possible.
5666 const NamedDecl *Def = getDefinitionToImport(D: Decl);
5667 if (!Def)
5668 Def = Decl;
5669
5670 Module *Owner = getOwningModule(Entity: Def);
5671 assert(Owner && "definition of hidden declaration is not in a module");
5672
5673 llvm::SmallVector<Module*, 8> OwningModules;
5674 OwningModules.push_back(Elt: Owner);
5675 auto Merged = Context.getModulesWithMergedDefinition(Def);
5676 llvm::append_range(C&: OwningModules, R&: Merged);
5677
5678 diagnoseMissingImport(Loc, Decl: Def, DeclLoc: Def->getLocation(), Modules: OwningModules, MIK,
5679 Recover);
5680}
5681
5682/// Get a "quoted.h" or <angled.h> include path to use in a diagnostic
5683/// suggesting the addition of a #include of the specified file.
5684static std::string getHeaderNameForHeader(Preprocessor &PP, FileEntryRef E,
5685 llvm::StringRef IncludingFile) {
5686 bool IsAngled = false;
5687 auto Path = PP.getHeaderSearchInfo().suggestPathToFileForDiagnostics(
5688 File: E, MainFile: IncludingFile, IsAngled: &IsAngled);
5689 return (IsAngled ? '<' : '"') + Path + (IsAngled ? '>' : '"');
5690}
5691
5692void Sema::diagnoseMissingImport(SourceLocation UseLoc, const NamedDecl *Decl,
5693 SourceLocation DeclLoc,
5694 ArrayRef<Module *> Modules,
5695 MissingImportKind MIK, bool Recover) {
5696 assert(!Modules.empty());
5697
5698 // See https://github.com/llvm/llvm-project/issues/73893. It is generally
5699 // confusing than helpful to show the namespace is not visible.
5700 if (isa<NamespaceDecl>(Val: Decl))
5701 return;
5702
5703 auto NotePrevious = [&] {
5704 // FIXME: Suppress the note backtrace even under
5705 // -fdiagnostics-show-note-include-stack. We don't care how this
5706 // declaration was previously reached.
5707 Diag(Loc: DeclLoc, DiagID: diag::note_unreachable_entity) << (int)MIK;
5708 };
5709
5710 // Weed out duplicates from module list.
5711 llvm::SmallVector<Module*, 8> UniqueModules;
5712 llvm::SmallDenseSet<Module*, 8> UniqueModuleSet;
5713 for (auto *M : Modules) {
5714 if (M->isExplicitGlobalModule() || M->isPrivateModule())
5715 continue;
5716 if (UniqueModuleSet.insert(V: M).second)
5717 UniqueModules.push_back(Elt: M);
5718 }
5719
5720 // Try to find a suitable header-name to #include.
5721 std::string HeaderName;
5722 if (OptionalFileEntryRef Header =
5723 PP.getHeaderToIncludeForDiagnostics(IncLoc: UseLoc, MLoc: DeclLoc)) {
5724 if (const FileEntry *FE =
5725 SourceMgr.getFileEntryForID(FID: SourceMgr.getFileID(SpellingLoc: UseLoc)))
5726 HeaderName =
5727 getHeaderNameForHeader(PP, E: *Header, IncludingFile: FE->tryGetRealPathName());
5728 }
5729
5730 // If we have a #include we should suggest, or if all definition locations
5731 // were in global module fragments, don't suggest an import.
5732 if (!HeaderName.empty() || UniqueModules.empty()) {
5733 // FIXME: Find a smart place to suggest inserting a #include, and add
5734 // a FixItHint there.
5735 Diag(Loc: UseLoc, DiagID: diag::err_module_unimported_use_header)
5736 << (int)MIK << Decl << !HeaderName.empty() << HeaderName;
5737 // Produce a note showing where the entity was declared.
5738 NotePrevious();
5739 if (Recover)
5740 createImplicitModuleImportForErrorRecovery(Loc: UseLoc, Mod: Modules[0]);
5741 return;
5742 }
5743
5744 Modules = UniqueModules;
5745
5746 auto GetModuleNameForDiagnostic = [this](const Module *M) -> std::string {
5747 if (M->isModuleMapModule())
5748 return M->getFullModuleName();
5749
5750 if (M->isImplicitGlobalModule())
5751 M = M->getTopLevelModule();
5752
5753 // If the current module unit is in the same module with M, it is OK to show
5754 // the partition name. Otherwise, it'll be sufficient to show the primary
5755 // module name.
5756 if (getASTContext().isInSameModule(M1: M, M2: getCurrentModule()))
5757 return M->getTopLevelModuleName().str();
5758 else
5759 return M->getPrimaryModuleInterfaceName().str();
5760 };
5761
5762 if (Modules.size() > 1) {
5763 std::string ModuleList;
5764 unsigned N = 0;
5765 for (const auto *M : Modules) {
5766 ModuleList += "\n ";
5767 if (++N == 5 && N != Modules.size()) {
5768 ModuleList += "[...]";
5769 break;
5770 }
5771 ModuleList += GetModuleNameForDiagnostic(M);
5772 }
5773
5774 Diag(Loc: UseLoc, DiagID: diag::err_module_unimported_use_multiple)
5775 << (int)MIK << Decl << ModuleList;
5776 } else {
5777 // FIXME: Add a FixItHint that imports the corresponding module.
5778 Diag(Loc: UseLoc, DiagID: diag::err_module_unimported_use)
5779 << (int)MIK << Decl << GetModuleNameForDiagnostic(Modules[0]);
5780 }
5781
5782 NotePrevious();
5783
5784 // Try to recover by implicitly importing this module.
5785 if (Recover)
5786 createImplicitModuleImportForErrorRecovery(Loc: UseLoc, Mod: Modules[0]);
5787}
5788
5789void Sema::diagnoseTypo(const TypoCorrection &Correction,
5790 const PartialDiagnostic &TypoDiag,
5791 const PartialDiagnostic &PrevNote,
5792 bool ErrorRecovery) {
5793 std::string CorrectedStr = Correction.getAsString(LO: getLangOpts());
5794 std::string CorrectedQuotedStr = Correction.getQuoted(LO: getLangOpts());
5795 FixItHint FixTypo = FixItHint::CreateReplacement(
5796 RemoveRange: Correction.getCorrectionRange(), Code: CorrectedStr);
5797
5798 // Maybe we're just missing a module import.
5799 if (Correction.requiresImport()) {
5800 NamedDecl *Decl = Correction.getFoundDecl();
5801 assert(Decl && "import required but no declaration to import");
5802
5803 diagnoseMissingImport(Loc: Correction.getCorrectionRange().getBegin(), Decl,
5804 MIK: MissingImportKind::Declaration, Recover: ErrorRecovery);
5805 return;
5806 }
5807
5808 Diag(Loc: Correction.getCorrectionRange().getBegin(), PD: TypoDiag)
5809 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
5810
5811 NamedDecl *ChosenDecl =
5812 Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
5813
5814 // For builtin functions which aren't declared anywhere in source,
5815 // don't emit the "declared here" note.
5816 if (const auto *FD = dyn_cast_if_present<FunctionDecl>(Val: ChosenDecl);
5817 FD && FD->getBuiltinID() &&
5818 PrevNote.getDiagID() == diag::note_previous_decl &&
5819 Correction.getCorrectionRange().getBegin() == FD->getBeginLoc()) {
5820 ChosenDecl = nullptr;
5821 }
5822
5823 if (PrevNote.getDiagID() && ChosenDecl)
5824 Diag(Loc: ChosenDecl->getLocation(), PD: PrevNote)
5825 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
5826
5827 // Add any extra diagnostics.
5828 for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
5829 Diag(Loc: Correction.getCorrectionRange().getBegin(), PD);
5830}
5831
5832void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) {
5833 DeclarationNameInfo Name(II, IILoc);
5834 LookupResult R(*this, Name, LookupAnyName,
5835 RedeclarationKind::NotForRedeclaration);
5836 R.suppressDiagnostics();
5837 R.setHideTags(false);
5838 LookupName(R, S);
5839 R.dump();
5840}
5841
5842void Sema::ActOnPragmaDump(Expr *E) {
5843 E->dump();
5844}
5845
5846RedeclarationKind Sema::forRedeclarationInCurContext() const {
5847 // A declaration with an owning module for linkage can never link against
5848 // anything that is not visible. We don't need to check linkage here; if
5849 // the context has internal linkage, redeclaration lookup won't find things
5850 // from other TUs, and we can't safely compute linkage yet in general.
5851 if (cast<Decl>(Val: CurContext)->getOwningModuleForLinkage())
5852 return RedeclarationKind::ForVisibleRedeclaration;
5853 return RedeclarationKind::ForExternalRedeclaration;
5854}
5855