1 //===--------------------- SemaLookup.cpp - Name Lookup ------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements name lookup for C, C++, Objective-C, and
13 //===----------------------------------------------------------------------===//
14 #include "clang/Sema/Lookup.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/CXXInheritance.h"
17 #include "clang/AST/Decl.h"
18 #include "clang/AST/DeclCXX.h"
19 #include "clang/AST/DeclLookups.h"
20 #include "clang/AST/DeclObjC.h"
21 #include "clang/AST/DeclTemplate.h"
22 #include "clang/AST/Expr.h"
23 #include "clang/AST/ExprCXX.h"
24 #include "clang/Basic/Builtins.h"
25 #include "clang/Basic/LangOptions.h"
26 #include "clang/Lex/ModuleLoader.h"
27 #include "clang/Sema/DeclSpec.h"
28 #include "clang/Sema/ExternalSemaSource.h"
29 #include "clang/Sema/Overload.h"
30 #include "clang/Sema/Scope.h"
31 #include "clang/Sema/ScopeInfo.h"
32 #include "clang/Sema/Sema.h"
33 #include "clang/Sema/SemaInternal.h"
34 #include "clang/Sema/TemplateDeduction.h"
35 #include "clang/Sema/TypoCorrection.h"
36 #include "llvm/ADT/STLExtras.h"
37 #include "llvm/ADT/SetVector.h"
38 #include "llvm/ADT/SmallPtrSet.h"
39 #include "llvm/ADT/StringMap.h"
40 #include "llvm/ADT/TinyPtrVector.h"
41 #include "llvm/ADT/edit_distance.h"
42 #include "llvm/Support/ErrorHandling.h"
52 using namespace clang;
56 class UnqualUsingEntry {
57 const DeclContext *Nominated;
58 const DeclContext *CommonAncestor;
61 UnqualUsingEntry(const DeclContext *Nominated,
62 const DeclContext *CommonAncestor)
63 : Nominated(Nominated), CommonAncestor(CommonAncestor) {
66 const DeclContext *getCommonAncestor() const {
67 return CommonAncestor;
70 const DeclContext *getNominatedNamespace() const {
74 // Sort by the pointer value of the common ancestor.
76 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) {
77 return L.getCommonAncestor() < R.getCommonAncestor();
80 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) {
81 return E.getCommonAncestor() < DC;
84 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) {
85 return DC < E.getCommonAncestor();
90 /// A collection of using directives, as used by C++ unqualified
92 class UnqualUsingDirectiveSet {
93 typedef SmallVector<UnqualUsingEntry, 8> ListTy;
96 llvm::SmallPtrSet<DeclContext*, 8> visited;
99 UnqualUsingDirectiveSet() {}
101 void visitScopeChain(Scope *S, Scope *InnermostFileScope) {
102 // C++ [namespace.udir]p1:
103 // During unqualified name lookup, the names appear as if they
104 // were declared in the nearest enclosing namespace which contains
105 // both the using-directive and the nominated namespace.
106 DeclContext *InnermostFileDC = InnermostFileScope->getEntity();
107 assert(InnermostFileDC && InnermostFileDC->isFileContext());
109 for (; S; S = S->getParent()) {
110 // C++ [namespace.udir]p1:
111 // A using-directive shall not appear in class scope, but may
112 // appear in namespace scope or in block scope.
113 DeclContext *Ctx = S->getEntity();
114 if (Ctx && Ctx->isFileContext()) {
116 } else if (!Ctx || Ctx->isFunctionOrMethod()) {
117 for (auto *I : S->using_directives())
118 visit(I, InnermostFileDC);
123 // Visits a context and collect all of its using directives
124 // recursively. Treats all using directives as if they were
125 // declared in the context.
127 // A given context is only every visited once, so it is important
128 // that contexts be visited from the inside out in order to get
129 // the effective DCs right.
130 void visit(DeclContext *DC, DeclContext *EffectiveDC) {
131 if (!visited.insert(DC))
134 addUsingDirectives(DC, EffectiveDC);
137 // Visits a using directive and collects all of its using
138 // directives recursively. Treats all using directives as if they
139 // were declared in the effective DC.
140 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
141 DeclContext *NS = UD->getNominatedNamespace();
142 if (!visited.insert(NS))
145 addUsingDirective(UD, EffectiveDC);
146 addUsingDirectives(NS, EffectiveDC);
149 // Adds all the using directives in a context (and those nominated
150 // by its using directives, transitively) as if they appeared in
151 // the given effective context.
152 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) {
153 SmallVector<DeclContext*,4> queue;
155 for (auto UD : DC->using_directives()) {
156 DeclContext *NS = UD->getNominatedNamespace();
157 if (visited.insert(NS)) {
158 addUsingDirective(UD, EffectiveDC);
166 DC = queue.pop_back_val();
170 // Add a using directive as if it had been declared in the given
171 // context. This helps implement C++ [namespace.udir]p3:
172 // The using-directive is transitive: if a scope contains a
173 // using-directive that nominates a second namespace that itself
174 // contains using-directives, the effect is as if the
175 // using-directives from the second namespace also appeared in
177 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
178 // Find the common ancestor between the effective context and
179 // the nominated namespace.
180 DeclContext *Common = UD->getNominatedNamespace();
181 while (!Common->Encloses(EffectiveDC))
182 Common = Common->getParent();
183 Common = Common->getPrimaryContext();
185 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common));
189 std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator());
192 typedef ListTy::const_iterator const_iterator;
194 const_iterator begin() const { return list.begin(); }
195 const_iterator end() const { return list.end(); }
197 std::pair<const_iterator,const_iterator>
198 getNamespacesFor(DeclContext *DC) const {
199 return std::equal_range(begin(), end(), DC->getPrimaryContext(),
200 UnqualUsingEntry::Comparator());
205 // Retrieve the set of identifier namespaces that correspond to a
206 // specific kind of name lookup.
207 static inline unsigned getIDNS(Sema::LookupNameKind NameKind,
209 bool Redeclaration) {
212 case Sema::LookupObjCImplicitSelfParam:
213 case Sema::LookupOrdinaryName:
214 case Sema::LookupRedeclarationWithLinkage:
215 case Sema::LookupLocalFriendName:
216 IDNS = Decl::IDNS_Ordinary;
218 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace;
220 IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend;
223 IDNS |= Decl::IDNS_LocalExtern;
226 case Sema::LookupOperatorName:
227 // Operator lookup is its own crazy thing; it is not the same
228 // as (e.g.) looking up an operator name for redeclaration.
229 assert(!Redeclaration && "cannot do redeclaration operator lookup");
230 IDNS = Decl::IDNS_NonMemberOperator;
233 case Sema::LookupTagName:
235 IDNS = Decl::IDNS_Type;
237 // When looking for a redeclaration of a tag name, we add:
238 // 1) TagFriend to find undeclared friend decls
239 // 2) Namespace because they can't "overload" with tag decls.
240 // 3) Tag because it includes class templates, which can't
241 // "overload" with tag decls.
243 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace;
245 IDNS = Decl::IDNS_Tag;
249 case Sema::LookupLabel:
250 IDNS = Decl::IDNS_Label;
253 case Sema::LookupMemberName:
254 IDNS = Decl::IDNS_Member;
256 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary;
259 case Sema::LookupNestedNameSpecifierName:
260 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace;
263 case Sema::LookupNamespaceName:
264 IDNS = Decl::IDNS_Namespace;
267 case Sema::LookupUsingDeclName:
268 assert(Redeclaration && "should only be used for redecl lookup");
269 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member |
270 Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend |
271 Decl::IDNS_LocalExtern;
274 case Sema::LookupObjCProtocolName:
275 IDNS = Decl::IDNS_ObjCProtocol;
278 case Sema::LookupAnyName:
279 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member
280 | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol
287 void LookupResult::configure() {
288 IDNS = getIDNS(LookupKind, SemaRef.getLangOpts().CPlusPlus,
289 isForRedeclaration());
291 // If we're looking for one of the allocation or deallocation
292 // operators, make sure that the implicitly-declared new and delete
293 // operators can be found.
294 switch (NameInfo.getName().getCXXOverloadedOperator()) {
298 case OO_Array_Delete:
299 SemaRef.DeclareGlobalNewDelete();
306 // Compiler builtins are always visible, regardless of where they end
307 // up being declared.
308 if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) {
309 if (unsigned BuiltinID = Id->getBuiltinID()) {
310 if (!SemaRef.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
316 bool LookupResult::sanity() const {
317 // This function is never called by NDEBUG builds.
318 assert(ResultKind != NotFound || Decls.size() == 0);
319 assert(ResultKind != Found || Decls.size() == 1);
320 assert(ResultKind != FoundOverloaded || Decls.size() > 1 ||
321 (Decls.size() == 1 &&
322 isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl())));
323 assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved());
324 assert(ResultKind != Ambiguous || Decls.size() > 1 ||
325 (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects ||
326 Ambiguity == AmbiguousBaseSubobjectTypes)));
327 assert((Paths != nullptr) == (ResultKind == Ambiguous &&
328 (Ambiguity == AmbiguousBaseSubobjectTypes ||
329 Ambiguity == AmbiguousBaseSubobjects)));
333 // Necessary because CXXBasePaths is not complete in Sema.h
334 void LookupResult::deletePaths(CXXBasePaths *Paths) {
338 /// Get a representative context for a declaration such that two declarations
339 /// will have the same context if they were found within the same scope.
340 static DeclContext *getContextForScopeMatching(Decl *D) {
341 // For function-local declarations, use that function as the context. This
342 // doesn't account for scopes within the function; the caller must deal with
344 DeclContext *DC = D->getLexicalDeclContext();
345 if (DC->isFunctionOrMethod())
348 // Otherwise, look at the semantic context of the declaration. The
349 // declaration must have been found there.
350 return D->getDeclContext()->getRedeclContext();
353 /// Resolves the result kind of this lookup.
354 void LookupResult::resolveKind() {
355 unsigned N = Decls.size();
357 // Fast case: no possible ambiguity.
359 assert(ResultKind == NotFound || ResultKind == NotFoundInCurrentInstantiation);
363 // If there's a single decl, we need to examine it to decide what
364 // kind of lookup this is.
366 NamedDecl *D = (*Decls.begin())->getUnderlyingDecl();
367 if (isa<FunctionTemplateDecl>(D))
368 ResultKind = FoundOverloaded;
369 else if (isa<UnresolvedUsingValueDecl>(D))
370 ResultKind = FoundUnresolvedValue;
374 // Don't do any extra resolution if we've already resolved as ambiguous.
375 if (ResultKind == Ambiguous) return;
377 llvm::SmallPtrSet<NamedDecl*, 16> Unique;
378 llvm::SmallPtrSet<QualType, 16> UniqueTypes;
380 bool Ambiguous = false;
381 bool HasTag = false, HasFunction = false, HasNonFunction = false;
382 bool HasFunctionTemplate = false, HasUnresolved = false;
384 unsigned UniqueTagIndex = 0;
388 NamedDecl *D = Decls[I]->getUnderlyingDecl();
389 D = cast<NamedDecl>(D->getCanonicalDecl());
391 // Ignore an invalid declaration unless it's the only one left.
392 if (D->isInvalidDecl() && I < N-1) {
393 Decls[I] = Decls[--N];
397 // Redeclarations of types via typedef can occur both within a scope
398 // and, through using declarations and directives, across scopes. There is
399 // no ambiguity if they all refer to the same type, so unique based on the
401 if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) {
402 if (!TD->getDeclContext()->isRecord()) {
403 QualType T = SemaRef.Context.getTypeDeclType(TD);
404 if (!UniqueTypes.insert(SemaRef.Context.getCanonicalType(T))) {
405 // The type is not unique; pull something off the back and continue
407 Decls[I] = Decls[--N];
413 if (!Unique.insert(D)) {
414 // If it's not unique, pull something off the back (and
415 // continue at this index).
416 Decls[I] = Decls[--N];
420 // Otherwise, do some decl type analysis and then continue.
422 if (isa<UnresolvedUsingValueDecl>(D)) {
423 HasUnresolved = true;
424 } else if (isa<TagDecl>(D)) {
429 } else if (isa<FunctionTemplateDecl>(D)) {
431 HasFunctionTemplate = true;
432 } else if (isa<FunctionDecl>(D)) {
437 HasNonFunction = true;
442 // C++ [basic.scope.hiding]p2:
443 // A class name or enumeration name can be hidden by the name of
444 // an object, function, or enumerator declared in the same
445 // scope. If a class or enumeration name and an object, function,
446 // or enumerator are declared in the same scope (in any order)
447 // with the same name, the class or enumeration name is hidden
448 // wherever the object, function, or enumerator name is visible.
449 // But it's still an error if there are distinct tag types found,
450 // even if they're not visible. (ref?)
451 if (HideTags && HasTag && !Ambiguous &&
452 (HasFunction || HasNonFunction || HasUnresolved)) {
453 if (getContextForScopeMatching(Decls[UniqueTagIndex])->Equals(
454 getContextForScopeMatching(Decls[UniqueTagIndex ? 0 : N - 1])))
455 Decls[UniqueTagIndex] = Decls[--N];
462 if (HasNonFunction && (HasFunction || HasUnresolved))
466 setAmbiguous(LookupResult::AmbiguousReference);
467 else if (HasUnresolved)
468 ResultKind = LookupResult::FoundUnresolvedValue;
469 else if (N > 1 || HasFunctionTemplate)
470 ResultKind = LookupResult::FoundOverloaded;
472 ResultKind = LookupResult::Found;
475 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
476 CXXBasePaths::const_paths_iterator I, E;
477 for (I = P.begin(), E = P.end(); I != E; ++I)
478 for (DeclContext::lookup_iterator DI = I->Decls.begin(),
479 DE = I->Decls.end(); DI != DE; ++DI)
483 void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) {
484 Paths = new CXXBasePaths;
486 addDeclsFromBasePaths(*Paths);
488 setAmbiguous(AmbiguousBaseSubobjects);
491 void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) {
492 Paths = new CXXBasePaths;
494 addDeclsFromBasePaths(*Paths);
496 setAmbiguous(AmbiguousBaseSubobjectTypes);
499 void LookupResult::print(raw_ostream &Out) {
500 Out << Decls.size() << " result(s)";
501 if (isAmbiguous()) Out << ", ambiguous";
502 if (Paths) Out << ", base paths present";
504 for (iterator I = begin(), E = end(); I != E; ++I) {
510 /// \brief Lookup a builtin function, when name lookup would otherwise
512 static bool LookupBuiltin(Sema &S, LookupResult &R) {
513 Sema::LookupNameKind NameKind = R.getLookupKind();
515 // If we didn't find a use of this identifier, and if the identifier
516 // corresponds to a compiler builtin, create the decl object for the builtin
517 // now, injecting it into translation unit scope, and return it.
518 if (NameKind == Sema::LookupOrdinaryName ||
519 NameKind == Sema::LookupRedeclarationWithLinkage) {
520 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo();
522 if (S.getLangOpts().CPlusPlus11 && S.getLangOpts().GNUMode &&
523 II == S.getFloat128Identifier()) {
524 // libstdc++4.7's type_traits expects type __float128 to exist, so
525 // insert a dummy type to make that header build in gnu++11 mode.
526 R.addDecl(S.getASTContext().getFloat128StubType());
530 // If this is a builtin on this (or all) targets, create the decl.
531 if (unsigned BuiltinID = II->getBuiltinID()) {
532 // In C++, we don't have any predefined library functions like
533 // 'malloc'. Instead, we'll just error.
534 if (S.getLangOpts().CPlusPlus &&
535 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
538 if (NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II,
539 BuiltinID, S.TUScope,
540 R.isForRedeclaration(),
552 /// \brief Determine whether we can declare a special member function within
553 /// the class at this point.
554 static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) {
555 // We need to have a definition for the class.
556 if (!Class->getDefinition() || Class->isDependentContext())
559 // We can't be in the middle of defining the class.
560 return !Class->isBeingDefined();
563 void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) {
564 if (!CanDeclareSpecialMemberFunction(Class))
567 // If the default constructor has not yet been declared, do so now.
568 if (Class->needsImplicitDefaultConstructor())
569 DeclareImplicitDefaultConstructor(Class);
571 // If the copy constructor has not yet been declared, do so now.
572 if (Class->needsImplicitCopyConstructor())
573 DeclareImplicitCopyConstructor(Class);
575 // If the copy assignment operator has not yet been declared, do so now.
576 if (Class->needsImplicitCopyAssignment())
577 DeclareImplicitCopyAssignment(Class);
579 if (getLangOpts().CPlusPlus11) {
580 // If the move constructor has not yet been declared, do so now.
581 if (Class->needsImplicitMoveConstructor())
582 DeclareImplicitMoveConstructor(Class); // might not actually do it
584 // If the move assignment operator has not yet been declared, do so now.
585 if (Class->needsImplicitMoveAssignment())
586 DeclareImplicitMoveAssignment(Class); // might not actually do it
589 // If the destructor has not yet been declared, do so now.
590 if (Class->needsImplicitDestructor())
591 DeclareImplicitDestructor(Class);
594 /// \brief Determine whether this is the name of an implicitly-declared
595 /// special member function.
596 static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) {
597 switch (Name.getNameKind()) {
598 case DeclarationName::CXXConstructorName:
599 case DeclarationName::CXXDestructorName:
602 case DeclarationName::CXXOperatorName:
603 return Name.getCXXOverloadedOperator() == OO_Equal;
612 /// \brief If there are any implicit member functions with the given name
613 /// that need to be declared in the given declaration context, do so.
614 static void DeclareImplicitMemberFunctionsWithName(Sema &S,
615 DeclarationName Name,
616 const DeclContext *DC) {
620 switch (Name.getNameKind()) {
621 case DeclarationName::CXXConstructorName:
622 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
623 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
624 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
625 if (Record->needsImplicitDefaultConstructor())
626 S.DeclareImplicitDefaultConstructor(Class);
627 if (Record->needsImplicitCopyConstructor())
628 S.DeclareImplicitCopyConstructor(Class);
629 if (S.getLangOpts().CPlusPlus11 &&
630 Record->needsImplicitMoveConstructor())
631 S.DeclareImplicitMoveConstructor(Class);
635 case DeclarationName::CXXDestructorName:
636 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
637 if (Record->getDefinition() && Record->needsImplicitDestructor() &&
638 CanDeclareSpecialMemberFunction(Record))
639 S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record));
642 case DeclarationName::CXXOperatorName:
643 if (Name.getCXXOverloadedOperator() != OO_Equal)
646 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) {
647 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
648 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
649 if (Record->needsImplicitCopyAssignment())
650 S.DeclareImplicitCopyAssignment(Class);
651 if (S.getLangOpts().CPlusPlus11 &&
652 Record->needsImplicitMoveAssignment())
653 S.DeclareImplicitMoveAssignment(Class);
663 // Adds all qualifying matches for a name within a decl context to the
664 // given lookup result. Returns true if any matches were found.
665 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
668 // Lazily declare C++ special member functions.
669 if (S.getLangOpts().CPlusPlus)
670 DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), DC);
672 // Perform lookup into this declaration context.
673 DeclContext::lookup_const_result DR = DC->lookup(R.getLookupName());
674 for (DeclContext::lookup_const_iterator I = DR.begin(), E = DR.end(); I != E;
677 if ((D = R.getAcceptableDecl(D))) {
683 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R))
686 if (R.getLookupName().getNameKind()
687 != DeclarationName::CXXConversionFunctionName ||
688 R.getLookupName().getCXXNameType()->isDependentType() ||
689 !isa<CXXRecordDecl>(DC))
693 // A specialization of a conversion function template is not found by
694 // name lookup. Instead, any conversion function templates visible in the
695 // context of the use are considered. [...]
696 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
697 if (!Record->isCompleteDefinition())
700 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(),
701 UEnd = Record->conversion_end(); U != UEnd; ++U) {
702 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
706 // When we're performing lookup for the purposes of redeclaration, just
707 // add the conversion function template. When we deduce template
708 // arguments for specializations, we'll end up unifying the return
709 // type of the new declaration with the type of the function template.
710 if (R.isForRedeclaration()) {
711 R.addDecl(ConvTemplate);
717 // [...] For each such operator, if argument deduction succeeds
718 // (14.9.2.3), the resulting specialization is used as if found by
721 // When referencing a conversion function for any purpose other than
722 // a redeclaration (such that we'll be building an expression with the
723 // result), perform template argument deduction and place the
724 // specialization into the result set. We do this to avoid forcing all
725 // callers to perform special deduction for conversion functions.
726 TemplateDeductionInfo Info(R.getNameLoc());
727 FunctionDecl *Specialization = nullptr;
729 const FunctionProtoType *ConvProto
730 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
731 assert(ConvProto && "Nonsensical conversion function template type");
733 // Compute the type of the function that we would expect the conversion
734 // function to have, if it were to match the name given.
735 // FIXME: Calling convention!
736 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo();
737 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C);
738 EPI.ExceptionSpecType = EST_None;
739 EPI.NumExceptions = 0;
740 QualType ExpectedType
741 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(),
744 // Perform template argument deduction against the type that we would
745 // expect the function to have.
746 if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType,
747 Specialization, Info)
748 == Sema::TDK_Success) {
749 R.addDecl(Specialization);
757 // Performs C++ unqualified lookup into the given file context.
759 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context,
760 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
762 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
764 // Perform direct name lookup into the LookupCtx.
765 bool Found = LookupDirect(S, R, NS);
767 // Perform direct name lookup into the namespaces nominated by the
768 // using directives whose common ancestor is this namespace.
769 UnqualUsingDirectiveSet::const_iterator UI, UEnd;
770 std::tie(UI, UEnd) = UDirs.getNamespacesFor(NS);
772 for (; UI != UEnd; ++UI)
773 if (LookupDirect(S, R, UI->getNominatedNamespace()))
781 static bool isNamespaceOrTranslationUnitScope(Scope *S) {
782 if (DeclContext *Ctx = S->getEntity())
783 return Ctx->isFileContext();
787 // Find the next outer declaration context from this scope. This
788 // routine actually returns the semantic outer context, which may
789 // differ from the lexical context (encoded directly in the Scope
790 // stack) when we are parsing a member of a class template. In this
791 // case, the second element of the pair will be true, to indicate that
792 // name lookup should continue searching in this semantic context when
793 // it leaves the current template parameter scope.
794 static std::pair<DeclContext *, bool> findOuterContext(Scope *S) {
795 DeclContext *DC = S->getEntity();
796 DeclContext *Lexical = nullptr;
797 for (Scope *OuterS = S->getParent(); OuterS;
798 OuterS = OuterS->getParent()) {
799 if (OuterS->getEntity()) {
800 Lexical = OuterS->getEntity();
805 // C++ [temp.local]p8:
806 // In the definition of a member of a class template that appears
807 // outside of the namespace containing the class template
808 // definition, the name of a template-parameter hides the name of
809 // a member of this namespace.
816 // template<class T> class B {
821 // template<class C> void N::B<C>::f(C) {
822 // C b; // C is the template parameter, not N::C
825 // In this example, the lexical context we return is the
826 // TranslationUnit, while the semantic context is the namespace N.
827 if (!Lexical || !DC || !S->getParent() ||
828 !S->getParent()->isTemplateParamScope())
829 return std::make_pair(Lexical, false);
831 // Find the outermost template parameter scope.
832 // For the example, this is the scope for the template parameters of
833 // template<class C>.
834 Scope *OutermostTemplateScope = S->getParent();
835 while (OutermostTemplateScope->getParent() &&
836 OutermostTemplateScope->getParent()->isTemplateParamScope())
837 OutermostTemplateScope = OutermostTemplateScope->getParent();
839 // Find the namespace context in which the original scope occurs. In
840 // the example, this is namespace N.
841 DeclContext *Semantic = DC;
842 while (!Semantic->isFileContext())
843 Semantic = Semantic->getParent();
845 // Find the declaration context just outside of the template
846 // parameter scope. This is the context in which the template is
847 // being lexically declaration (a namespace context). In the
848 // example, this is the global scope.
849 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) &&
850 Lexical->Encloses(Semantic))
851 return std::make_pair(Semantic, true);
853 return std::make_pair(Lexical, false);
857 /// An RAII object to specify that we want to find block scope extern
859 struct FindLocalExternScope {
860 FindLocalExternScope(LookupResult &R)
861 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
862 Decl::IDNS_LocalExtern) {
863 R.setFindLocalExtern(R.getIdentifierNamespace() & Decl::IDNS_Ordinary);
866 R.setFindLocalExtern(OldFindLocalExtern);
868 ~FindLocalExternScope() {
872 bool OldFindLocalExtern;
876 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
877 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
879 DeclarationName Name = R.getLookupName();
880 Sema::LookupNameKind NameKind = R.getLookupKind();
882 // If this is the name of an implicitly-declared special member function,
883 // go through the scope stack to implicitly declare
884 if (isImplicitlyDeclaredMemberFunctionName(Name)) {
885 for (Scope *PreS = S; PreS; PreS = PreS->getParent())
886 if (DeclContext *DC = PreS->getEntity())
887 DeclareImplicitMemberFunctionsWithName(*this, Name, DC);
890 // Implicitly declare member functions with the name we're looking for, if in
891 // fact we are in a scope where it matters.
894 IdentifierResolver::iterator
895 I = IdResolver.begin(Name),
896 IEnd = IdResolver.end();
898 // First we lookup local scope.
899 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
900 // ...During unqualified name lookup (3.4.1), the names appear as if
901 // they were declared in the nearest enclosing namespace which contains
902 // both the using-directive and the nominated namespace.
903 // [Note: in this context, "contains" means "contains directly or
907 // namespace A { int i; }
911 // using namespace A;
912 // ++i; // finds local 'i', A::i appears at global scope
916 UnqualUsingDirectiveSet UDirs;
917 bool VisitedUsingDirectives = false;
918 bool LeftStartingScope = false;
919 DeclContext *OutsideOfTemplateParamDC = nullptr;
921 // When performing a scope lookup, we want to find local extern decls.
922 FindLocalExternScope FindLocals(R);
924 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
925 DeclContext *Ctx = S->getEntity();
927 // Check whether the IdResolver has anything in this scope.
929 for (; I != IEnd && S->isDeclScope(*I); ++I) {
930 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
931 if (NameKind == LookupRedeclarationWithLinkage) {
932 // Determine whether this (or a previous) declaration is
934 if (!LeftStartingScope && !Initial->isDeclScope(*I))
935 LeftStartingScope = true;
937 // If we found something outside of our starting scope that
938 // does not have linkage, skip it. If it's a template parameter,
939 // we still find it, so we can diagnose the invalid redeclaration.
940 if (LeftStartingScope && !((*I)->hasLinkage()) &&
941 !(*I)->isTemplateParameter()) {
953 if (S->isClassScope())
954 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx))
955 R.setNamingClass(Record);
959 if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
960 // C++11 [class.friend]p11:
961 // If a friend declaration appears in a local class and the name
962 // specified is an unqualified name, a prior declaration is
963 // looked up without considering scopes that are outside the
964 // innermost enclosing non-class scope.
968 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
969 S->getParent() && !S->getParent()->isTemplateParamScope()) {
970 // We've just searched the last template parameter scope and
971 // found nothing, so look into the contexts between the
972 // lexical and semantic declaration contexts returned by
973 // findOuterContext(). This implements the name lookup behavior
974 // of C++ [temp.local]p8.
975 Ctx = OutsideOfTemplateParamDC;
976 OutsideOfTemplateParamDC = nullptr;
980 DeclContext *OuterCtx;
981 bool SearchAfterTemplateScope;
982 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
983 if (SearchAfterTemplateScope)
984 OutsideOfTemplateParamDC = OuterCtx;
986 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
987 // We do not directly look into transparent contexts, since
988 // those entities will be found in the nearest enclosing
989 // non-transparent context.
990 if (Ctx->isTransparentContext())
993 // We do not look directly into function or method contexts,
994 // since all of the local variables and parameters of the
995 // function/method are present within the Scope.
996 if (Ctx->isFunctionOrMethod()) {
997 // If we have an Objective-C instance method, look for ivars
998 // in the corresponding interface.
999 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
1000 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
1001 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
1002 ObjCInterfaceDecl *ClassDeclared;
1003 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
1004 Name.getAsIdentifierInfo(),
1006 if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
1018 // If this is a file context, we need to perform unqualified name
1019 // lookup considering using directives.
1020 if (Ctx->isFileContext()) {
1021 // If we haven't handled using directives yet, do so now.
1022 if (!VisitedUsingDirectives) {
1023 // Add using directives from this context up to the top level.
1024 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
1025 if (UCtx->isTransparentContext())
1028 UDirs.visit(UCtx, UCtx);
1031 // Find the innermost file scope, so we can add using directives
1032 // from local scopes.
1033 Scope *InnermostFileScope = S;
1034 while (InnermostFileScope &&
1035 !isNamespaceOrTranslationUnitScope(InnermostFileScope))
1036 InnermostFileScope = InnermostFileScope->getParent();
1037 UDirs.visitScopeChain(Initial, InnermostFileScope);
1041 VisitedUsingDirectives = true;
1044 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
1052 // Perform qualified name lookup into this context.
1053 // FIXME: In some cases, we know that every name that could be found by
1054 // this qualified name lookup will also be on the identifier chain. For
1055 // example, inside a class without any base classes, we never need to
1056 // perform qualified lookup because all of the members are on top of the
1057 // identifier chain.
1058 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
1064 // Stop if we ran out of scopes.
1065 // FIXME: This really, really shouldn't be happening.
1066 if (!S) return false;
1068 // If we are looking for members, no need to look into global/namespace scope.
1069 if (NameKind == LookupMemberName)
1072 // Collect UsingDirectiveDecls in all scopes, and recursively all
1073 // nominated namespaces by those using-directives.
1075 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
1076 // don't build it for each lookup!
1077 if (!VisitedUsingDirectives) {
1078 UDirs.visitScopeChain(Initial, S);
1082 // If we're not performing redeclaration lookup, do not look for local
1083 // extern declarations outside of a function scope.
1084 if (!R.isForRedeclaration())
1085 FindLocals.restore();
1087 // Lookup namespace scope, and global scope.
1088 // Unqualified name lookup in C++ requires looking into scopes
1089 // that aren't strictly lexical, and therefore we walk through the
1090 // context as well as walking through the scopes.
1091 for (; S; S = S->getParent()) {
1092 // Check whether the IdResolver has anything in this scope.
1094 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1095 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1096 // We found something. Look for anything else in our scope
1097 // with this same name and in an acceptable identifier
1098 // namespace, so that we can construct an overload set if we
1105 if (Found && S->isTemplateParamScope()) {
1110 DeclContext *Ctx = S->getEntity();
1111 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1112 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1113 // We've just searched the last template parameter scope and
1114 // found nothing, so look into the contexts between the
1115 // lexical and semantic declaration contexts returned by
1116 // findOuterContext(). This implements the name lookup behavior
1117 // of C++ [temp.local]p8.
1118 Ctx = OutsideOfTemplateParamDC;
1119 OutsideOfTemplateParamDC = nullptr;
1123 DeclContext *OuterCtx;
1124 bool SearchAfterTemplateScope;
1125 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1126 if (SearchAfterTemplateScope)
1127 OutsideOfTemplateParamDC = OuterCtx;
1129 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1130 // We do not directly look into transparent contexts, since
1131 // those entities will be found in the nearest enclosing
1132 // non-transparent context.
1133 if (Ctx->isTransparentContext())
1136 // If we have a context, and it's not a context stashed in the
1137 // template parameter scope for an out-of-line definition, also
1138 // look into that context.
1139 if (!(Found && S && S->isTemplateParamScope())) {
1140 assert(Ctx->isFileContext() &&
1141 "We should have been looking only at file context here already.");
1143 // Look into context considering using-directives.
1144 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
1153 if (R.isForRedeclaration() && !Ctx->isTransparentContext())
1158 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
1165 /// \brief Find the declaration that a class temploid member specialization was
1166 /// instantiated from, or the member itself if it is an explicit specialization.
1167 static Decl *getInstantiatedFrom(Decl *D, MemberSpecializationInfo *MSInfo) {
1168 return MSInfo->isExplicitSpecialization() ? D : MSInfo->getInstantiatedFrom();
1171 /// \brief Find the module in which the given declaration was defined.
1172 static Module *getDefiningModule(Decl *Entity) {
1173 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
1174 // If this function was instantiated from a template, the defining module is
1175 // the module containing the pattern.
1176 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1178 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
1179 // If it's a class template specialization, find the template or partial
1180 // specialization from which it was instantiated.
1181 if (ClassTemplateSpecializationDecl *SpecRD =
1182 dyn_cast<ClassTemplateSpecializationDecl>(RD)) {
1183 llvm::PointerUnion<ClassTemplateDecl*,
1184 ClassTemplatePartialSpecializationDecl*> From =
1185 SpecRD->getInstantiatedFrom();
1186 if (ClassTemplateDecl *FromTemplate = From.dyn_cast<ClassTemplateDecl*>())
1187 Entity = FromTemplate->getTemplatedDecl();
1189 Entity = From.get<ClassTemplatePartialSpecializationDecl*>();
1190 // Otherwise, it's an explicit specialization.
1191 } else if (MemberSpecializationInfo *MSInfo =
1192 RD->getMemberSpecializationInfo())
1193 Entity = getInstantiatedFrom(RD, MSInfo);
1194 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
1195 if (MemberSpecializationInfo *MSInfo = ED->getMemberSpecializationInfo())
1196 Entity = getInstantiatedFrom(ED, MSInfo);
1197 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
1198 // FIXME: Map from variable template specializations back to the template.
1199 if (MemberSpecializationInfo *MSInfo = VD->getMemberSpecializationInfo())
1200 Entity = getInstantiatedFrom(VD, MSInfo);
1203 // Walk up to the containing context. That might also have been instantiated
1205 DeclContext *Context = Entity->getDeclContext();
1206 if (Context->isFileContext())
1207 return Entity->getOwningModule();
1208 return getDefiningModule(cast<Decl>(Context));
1211 llvm::DenseSet<Module*> &Sema::getLookupModules() {
1212 unsigned N = ActiveTemplateInstantiations.size();
1213 for (unsigned I = ActiveTemplateInstantiationLookupModules.size();
1215 Module *M = getDefiningModule(ActiveTemplateInstantiations[I].Entity);
1216 if (M && !LookupModulesCache.insert(M).second)
1218 ActiveTemplateInstantiationLookupModules.push_back(M);
1220 return LookupModulesCache;
1223 /// \brief Determine whether a declaration is visible to name lookup.
1225 /// This routine determines whether the declaration D is visible in the current
1226 /// lookup context, taking into account the current template instantiation
1227 /// stack. During template instantiation, a declaration is visible if it is
1228 /// visible from a module containing any entity on the template instantiation
1229 /// path (by instantiating a template, you allow it to see the declarations that
1230 /// your module can see, including those later on in your module).
1231 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
1232 assert(D->isHidden() && !SemaRef.ActiveTemplateInstantiations.empty() &&
1233 "should not call this: not in slow case");
1234 Module *DeclModule = D->getOwningModule();
1235 assert(DeclModule && "hidden decl not from a module");
1237 // Find the extra places where we need to look.
1238 llvm::DenseSet<Module*> &LookupModules = SemaRef.getLookupModules();
1239 if (LookupModules.empty())
1242 // If our lookup set contains the decl's module, it's visible.
1243 if (LookupModules.count(DeclModule))
1246 // If the declaration isn't exported, it's not visible in any other module.
1247 if (D->isModulePrivate())
1250 // Check whether DeclModule is transitively exported to an import of
1252 for (llvm::DenseSet<Module *>::iterator I = LookupModules.begin(),
1253 E = LookupModules.end();
1255 if ((*I)->isModuleVisible(DeclModule))
1260 /// \brief Retrieve the visible declaration corresponding to D, if any.
1262 /// This routine determines whether the declaration D is visible in the current
1263 /// module, with the current imports. If not, it checks whether any
1264 /// redeclaration of D is visible, and if so, returns that declaration.
1266 /// \returns D, or a visible previous declaration of D, whichever is more recent
1267 /// and visible. If no declaration of D is visible, returns null.
1268 static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D) {
1269 assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case");
1271 for (auto RD : D->redecls()) {
1272 if (auto ND = dyn_cast<NamedDecl>(RD)) {
1273 if (LookupResult::isVisible(SemaRef, ND))
1281 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
1282 return findAcceptableDecl(SemaRef, D);
1285 /// @brief Perform unqualified name lookup starting from a given
1288 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
1289 /// used to find names within the current scope. For example, 'x' in
1293 /// return x; // unqualified name look finds 'x' in the global scope
1297 /// Different lookup criteria can find different names. For example, a
1298 /// particular scope can have both a struct and a function of the same
1299 /// name, and each can be found by certain lookup criteria. For more
1300 /// information about lookup criteria, see the documentation for the
1301 /// class LookupCriteria.
1303 /// @param S The scope from which unqualified name lookup will
1304 /// begin. If the lookup criteria permits, name lookup may also search
1305 /// in the parent scopes.
1307 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to
1308 /// look up and the lookup kind), and is updated with the results of lookup
1309 /// including zero or more declarations and possibly additional information
1310 /// used to diagnose ambiguities.
1312 /// @returns \c true if lookup succeeded and false otherwise.
1313 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
1314 DeclarationName Name = R.getLookupName();
1315 if (!Name) return false;
1317 LookupNameKind NameKind = R.getLookupKind();
1319 if (!getLangOpts().CPlusPlus) {
1320 // Unqualified name lookup in C/Objective-C is purely lexical, so
1321 // search in the declarations attached to the name.
1322 if (NameKind == Sema::LookupRedeclarationWithLinkage) {
1323 // Find the nearest non-transparent declaration scope.
1324 while (!(S->getFlags() & Scope::DeclScope) ||
1325 (S->getEntity() && S->getEntity()->isTransparentContext()))
1329 // When performing a scope lookup, we want to find local extern decls.
1330 FindLocalExternScope FindLocals(R);
1332 // Scan up the scope chain looking for a decl that matches this
1333 // identifier that is in the appropriate namespace. This search
1334 // should not take long, as shadowing of names is uncommon, and
1335 // deep shadowing is extremely uncommon.
1336 bool LeftStartingScope = false;
1338 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
1339 IEnd = IdResolver.end();
1341 if (NamedDecl *D = R.getAcceptableDecl(*I)) {
1342 if (NameKind == LookupRedeclarationWithLinkage) {
1343 // Determine whether this (or a previous) declaration is
1345 if (!LeftStartingScope && !S->isDeclScope(*I))
1346 LeftStartingScope = true;
1348 // If we found something outside of our starting scope that
1349 // does not have linkage, skip it.
1350 if (LeftStartingScope && !((*I)->hasLinkage())) {
1355 else if (NameKind == LookupObjCImplicitSelfParam &&
1356 !isa<ImplicitParamDecl>(*I))
1361 // Check whether there are any other declarations with the same name
1362 // and in the same scope.
1364 // Find the scope in which this declaration was declared (if it
1365 // actually exists in a Scope).
1366 while (S && !S->isDeclScope(D))
1369 // If the scope containing the declaration is the translation unit,
1370 // then we'll need to perform our checks based on the matching
1371 // DeclContexts rather than matching scopes.
1372 if (S && isNamespaceOrTranslationUnitScope(S))
1375 // Compute the DeclContext, if we need it.
1376 DeclContext *DC = nullptr;
1378 DC = (*I)->getDeclContext()->getRedeclContext();
1380 IdentifierResolver::iterator LastI = I;
1381 for (++LastI; LastI != IEnd; ++LastI) {
1383 // Match based on scope.
1384 if (!S->isDeclScope(*LastI))
1387 // Match based on DeclContext.
1389 = (*LastI)->getDeclContext()->getRedeclContext();
1390 if (!LastDC->Equals(DC))
1394 // If the declaration is in the right namespace and visible, add it.
1395 if (NamedDecl *LastD = R.getAcceptableDecl(*LastI))
1405 // Perform C++ unqualified name lookup.
1406 if (CppLookupName(R, S))
1410 // If we didn't find a use of this identifier, and if the identifier
1411 // corresponds to a compiler builtin, create the decl object for the builtin
1412 // now, injecting it into translation unit scope, and return it.
1413 if (AllowBuiltinCreation && LookupBuiltin(*this, R))
1416 // If we didn't find a use of this identifier, the ExternalSource
1417 // may be able to handle the situation.
1418 // Note: some lookup failures are expected!
1419 // See e.g. R.isForRedeclaration().
1420 return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
1423 /// @brief Perform qualified name lookup in the namespaces nominated by
1424 /// using directives by the given context.
1426 /// C++98 [namespace.qual]p2:
1427 /// Given X::m (where X is a user-declared namespace), or given \::m
1428 /// (where X is the global namespace), let S be the set of all
1429 /// declarations of m in X and in the transitive closure of all
1430 /// namespaces nominated by using-directives in X and its used
1431 /// namespaces, except that using-directives are ignored in any
1432 /// namespace, including X, directly containing one or more
1433 /// declarations of m. No namespace is searched more than once in
1434 /// the lookup of a name. If S is the empty set, the program is
1435 /// ill-formed. Otherwise, if S has exactly one member, or if the
1436 /// context of the reference is a using-declaration
1437 /// (namespace.udecl), S is the required set of declarations of
1438 /// m. Otherwise if the use of m is not one that allows a unique
1439 /// declaration to be chosen from S, the program is ill-formed.
1441 /// C++98 [namespace.qual]p5:
1442 /// During the lookup of a qualified namespace member name, if the
1443 /// lookup finds more than one declaration of the member, and if one
1444 /// declaration introduces a class name or enumeration name and the
1445 /// other declarations either introduce the same object, the same
1446 /// enumerator or a set of functions, the non-type name hides the
1447 /// class or enumeration name if and only if the declarations are
1448 /// from the same namespace; otherwise (the declarations are from
1449 /// different namespaces), the program is ill-formed.
1450 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
1451 DeclContext *StartDC) {
1452 assert(StartDC->isFileContext() && "start context is not a file context");
1454 DeclContext::udir_range UsingDirectives = StartDC->using_directives();
1455 if (UsingDirectives.begin() == UsingDirectives.end()) return false;
1457 // We have at least added all these contexts to the queue.
1458 llvm::SmallPtrSet<DeclContext*, 8> Visited;
1459 Visited.insert(StartDC);
1461 // We have not yet looked into these namespaces, much less added
1462 // their "using-children" to the queue.
1463 SmallVector<NamespaceDecl*, 8> Queue;
1465 // We have already looked into the initial namespace; seed the queue
1466 // with its using-children.
1467 for (auto *I : UsingDirectives) {
1468 NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace();
1469 if (Visited.insert(ND))
1470 Queue.push_back(ND);
1473 // The easiest way to implement the restriction in [namespace.qual]p5
1474 // is to check whether any of the individual results found a tag
1475 // and, if so, to declare an ambiguity if the final result is not
1477 bool FoundTag = false;
1478 bool FoundNonTag = false;
1480 LookupResult LocalR(LookupResult::Temporary, R);
1483 while (!Queue.empty()) {
1484 NamespaceDecl *ND = Queue.pop_back_val();
1486 // We go through some convolutions here to avoid copying results
1487 // between LookupResults.
1488 bool UseLocal = !R.empty();
1489 LookupResult &DirectR = UseLocal ? LocalR : R;
1490 bool FoundDirect = LookupDirect(S, DirectR, ND);
1493 // First do any local hiding.
1494 DirectR.resolveKind();
1496 // If the local result is a tag, remember that.
1497 if (DirectR.isSingleTagDecl())
1502 // Append the local results to the total results if necessary.
1504 R.addAllDecls(LocalR);
1509 // If we find names in this namespace, ignore its using directives.
1515 for (auto I : ND->using_directives()) {
1516 NamespaceDecl *Nom = I->getNominatedNamespace();
1517 if (Visited.insert(Nom))
1518 Queue.push_back(Nom);
1523 if (FoundTag && FoundNonTag)
1524 R.setAmbiguousQualifiedTagHiding();
1532 /// \brief Callback that looks for any member of a class with the given name.
1533 static bool LookupAnyMember(const CXXBaseSpecifier *Specifier,
1536 RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
1538 DeclarationName N = DeclarationName::getFromOpaquePtr(Name);
1539 Path.Decls = BaseRecord->lookup(N);
1540 return !Path.Decls.empty();
1543 /// \brief Determine whether the given set of member declarations contains only
1544 /// static members, nested types, and enumerators.
1545 template<typename InputIterator>
1546 static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) {
1547 Decl *D = (*First)->getUnderlyingDecl();
1548 if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D))
1551 if (isa<CXXMethodDecl>(D)) {
1552 // Determine whether all of the methods are static.
1553 bool AllMethodsAreStatic = true;
1554 for(; First != Last; ++First) {
1555 D = (*First)->getUnderlyingDecl();
1557 if (!isa<CXXMethodDecl>(D)) {
1558 assert(isa<TagDecl>(D) && "Non-function must be a tag decl");
1562 if (!cast<CXXMethodDecl>(D)->isStatic()) {
1563 AllMethodsAreStatic = false;
1568 if (AllMethodsAreStatic)
1575 /// \brief Perform qualified name lookup into a given context.
1577 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
1578 /// names when the context of those names is explicit specified, e.g.,
1579 /// "std::vector" or "x->member", or as part of unqualified name lookup.
1581 /// Different lookup criteria can find different names. For example, a
1582 /// particular scope can have both a struct and a function of the same
1583 /// name, and each can be found by certain lookup criteria. For more
1584 /// information about lookup criteria, see the documentation for the
1585 /// class LookupCriteria.
1587 /// \param R captures both the lookup criteria and any lookup results found.
1589 /// \param LookupCtx The context in which qualified name lookup will
1590 /// search. If the lookup criteria permits, name lookup may also search
1591 /// in the parent contexts or (for C++ classes) base classes.
1593 /// \param InUnqualifiedLookup true if this is qualified name lookup that
1594 /// occurs as part of unqualified name lookup.
1596 /// \returns true if lookup succeeded, false if it failed.
1597 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
1598 bool InUnqualifiedLookup) {
1599 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
1601 if (!R.getLookupName())
1604 // Make sure that the declaration context is complete.
1605 assert((!isa<TagDecl>(LookupCtx) ||
1606 LookupCtx->isDependentContext() ||
1607 cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
1608 cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
1609 "Declaration context must already be complete!");
1611 // Perform qualified name lookup into the LookupCtx.
1612 if (LookupDirect(*this, R, LookupCtx)) {
1614 if (isa<CXXRecordDecl>(LookupCtx))
1615 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
1619 // Don't descend into implied contexts for redeclarations.
1620 // C++98 [namespace.qual]p6:
1621 // In a declaration for a namespace member in which the
1622 // declarator-id is a qualified-id, given that the qualified-id
1623 // for the namespace member has the form
1624 // nested-name-specifier unqualified-id
1625 // the unqualified-id shall name a member of the namespace
1626 // designated by the nested-name-specifier.
1627 // See also [class.mfct]p5 and [class.static.data]p2.
1628 if (R.isForRedeclaration())
1631 // If this is a namespace, look it up in the implied namespaces.
1632 if (LookupCtx->isFileContext())
1633 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
1635 // If this isn't a C++ class, we aren't allowed to look into base
1636 // classes, we're done.
1637 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
1638 if (!LookupRec || !LookupRec->getDefinition())
1641 // If we're performing qualified name lookup into a dependent class,
1642 // then we are actually looking into a current instantiation. If we have any
1643 // dependent base classes, then we either have to delay lookup until
1644 // template instantiation time (at which point all bases will be available)
1645 // or we have to fail.
1646 if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
1647 LookupRec->hasAnyDependentBases()) {
1648 R.setNotFoundInCurrentInstantiation();
1652 // Perform lookup into our base classes.
1654 Paths.setOrigin(LookupRec);
1656 // Look for this member in our base classes
1657 CXXRecordDecl::BaseMatchesCallback *BaseCallback = nullptr;
1658 switch (R.getLookupKind()) {
1659 case LookupObjCImplicitSelfParam:
1660 case LookupOrdinaryName:
1661 case LookupMemberName:
1662 case LookupRedeclarationWithLinkage:
1663 case LookupLocalFriendName:
1664 BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
1668 BaseCallback = &CXXRecordDecl::FindTagMember;
1672 BaseCallback = &LookupAnyMember;
1675 case LookupUsingDeclName:
1676 // This lookup is for redeclarations only.
1678 case LookupOperatorName:
1679 case LookupNamespaceName:
1680 case LookupObjCProtocolName:
1682 // These lookups will never find a member in a C++ class (or base class).
1685 case LookupNestedNameSpecifierName:
1686 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember;
1690 if (!LookupRec->lookupInBases(BaseCallback,
1691 R.getLookupName().getAsOpaquePtr(), Paths))
1694 R.setNamingClass(LookupRec);
1696 // C++ [class.member.lookup]p2:
1697 // [...] If the resulting set of declarations are not all from
1698 // sub-objects of the same type, or the set has a nonstatic member
1699 // and includes members from distinct sub-objects, there is an
1700 // ambiguity and the program is ill-formed. Otherwise that set is
1701 // the result of the lookup.
1702 QualType SubobjectType;
1703 int SubobjectNumber = 0;
1704 AccessSpecifier SubobjectAccess = AS_none;
1706 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
1707 Path != PathEnd; ++Path) {
1708 const CXXBasePathElement &PathElement = Path->back();
1710 // Pick the best (i.e. most permissive i.e. numerically lowest) access
1711 // across all paths.
1712 SubobjectAccess = std::min(SubobjectAccess, Path->Access);
1714 // Determine whether we're looking at a distinct sub-object or not.
1715 if (SubobjectType.isNull()) {
1716 // This is the first subobject we've looked at. Record its type.
1717 SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
1718 SubobjectNumber = PathElement.SubobjectNumber;
1723 != Context.getCanonicalType(PathElement.Base->getType())) {
1724 // We found members of the given name in two subobjects of
1725 // different types. If the declaration sets aren't the same, this
1726 // lookup is ambiguous.
1727 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) {
1728 CXXBasePaths::paths_iterator FirstPath = Paths.begin();
1729 DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin();
1730 DeclContext::lookup_iterator CurrentD = Path->Decls.begin();
1732 while (FirstD != FirstPath->Decls.end() &&
1733 CurrentD != Path->Decls.end()) {
1734 if ((*FirstD)->getUnderlyingDecl()->getCanonicalDecl() !=
1735 (*CurrentD)->getUnderlyingDecl()->getCanonicalDecl())
1742 if (FirstD == FirstPath->Decls.end() &&
1743 CurrentD == Path->Decls.end())
1747 R.setAmbiguousBaseSubobjectTypes(Paths);
1751 if (SubobjectNumber != PathElement.SubobjectNumber) {
1752 // We have a different subobject of the same type.
1754 // C++ [class.member.lookup]p5:
1755 // A static member, a nested type or an enumerator defined in
1756 // a base class T can unambiguously be found even if an object
1757 // has more than one base class subobject of type T.
1758 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end()))
1761 // We have found a nonstatic member name in multiple, distinct
1762 // subobjects. Name lookup is ambiguous.
1763 R.setAmbiguousBaseSubobjects(Paths);
1768 // Lookup in a base class succeeded; return these results.
1770 for (auto *D : Paths.front().Decls) {
1771 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
1779 /// @brief Performs name lookup for a name that was parsed in the
1780 /// source code, and may contain a C++ scope specifier.
1782 /// This routine is a convenience routine meant to be called from
1783 /// contexts that receive a name and an optional C++ scope specifier
1784 /// (e.g., "N::M::x"). It will then perform either qualified or
1785 /// unqualified name lookup (with LookupQualifiedName or LookupName,
1786 /// respectively) on the given name and return those results.
1788 /// @param S The scope from which unqualified name lookup will
1791 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
1793 /// @param EnteringContext Indicates whether we are going to enter the
1794 /// context of the scope-specifier SS (if present).
1796 /// @returns True if any decls were found (but possibly ambiguous)
1797 bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
1798 bool AllowBuiltinCreation, bool EnteringContext) {
1799 if (SS && SS->isInvalid()) {
1800 // When the scope specifier is invalid, don't even look for
1805 if (SS && SS->isSet()) {
1806 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
1807 // We have resolved the scope specifier to a particular declaration
1808 // contex, and will perform name lookup in that context.
1809 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
1812 R.setContextRange(SS->getRange());
1813 return LookupQualifiedName(R, DC);
1816 // We could not resolve the scope specified to a specific declaration
1817 // context, which means that SS refers to an unknown specialization.
1818 // Name lookup can't find anything in this case.
1819 R.setNotFoundInCurrentInstantiation();
1820 R.setContextRange(SS->getRange());
1824 // Perform unqualified name lookup starting in the given scope.
1825 return LookupName(R, S, AllowBuiltinCreation);
1829 /// \brief Produce a diagnostic describing the ambiguity that resulted
1830 /// from name lookup.
1832 /// \param Result The result of the ambiguous lookup to be diagnosed.
1833 void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
1834 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
1836 DeclarationName Name = Result.getLookupName();
1837 SourceLocation NameLoc = Result.getNameLoc();
1838 SourceRange LookupRange = Result.getContextRange();
1840 switch (Result.getAmbiguityKind()) {
1841 case LookupResult::AmbiguousBaseSubobjects: {
1842 CXXBasePaths *Paths = Result.getBasePaths();
1843 QualType SubobjectType = Paths->front().back().Base->getType();
1844 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
1845 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
1848 DeclContext::lookup_iterator Found = Paths->front().Decls.begin();
1849 while (isa<CXXMethodDecl>(*Found) &&
1850 cast<CXXMethodDecl>(*Found)->isStatic())
1853 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
1857 case LookupResult::AmbiguousBaseSubobjectTypes: {
1858 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
1859 << Name << LookupRange;
1861 CXXBasePaths *Paths = Result.getBasePaths();
1862 std::set<Decl *> DeclsPrinted;
1863 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
1864 PathEnd = Paths->end();
1865 Path != PathEnd; ++Path) {
1866 Decl *D = Path->Decls.front();
1867 if (DeclsPrinted.insert(D).second)
1868 Diag(D->getLocation(), diag::note_ambiguous_member_found);
1873 case LookupResult::AmbiguousTagHiding: {
1874 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
1876 llvm::SmallPtrSet<NamedDecl*,8> TagDecls;
1878 for (auto *D : Result)
1879 if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
1880 TagDecls.insert(TD);
1881 Diag(TD->getLocation(), diag::note_hidden_tag);
1884 for (auto *D : Result)
1885 if (!isa<TagDecl>(D))
1886 Diag(D->getLocation(), diag::note_hiding_object);
1888 // For recovery purposes, go ahead and implement the hiding.
1889 LookupResult::Filter F = Result.makeFilter();
1890 while (F.hasNext()) {
1891 if (TagDecls.count(F.next()))
1898 case LookupResult::AmbiguousReference: {
1899 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
1901 for (auto *D : Result)
1902 Diag(D->getLocation(), diag::note_ambiguous_candidate) << D;
1909 struct AssociatedLookup {
1910 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
1911 Sema::AssociatedNamespaceSet &Namespaces,
1912 Sema::AssociatedClassSet &Classes)
1913 : S(S), Namespaces(Namespaces), Classes(Classes),
1914 InstantiationLoc(InstantiationLoc) {
1918 Sema::AssociatedNamespaceSet &Namespaces;
1919 Sema::AssociatedClassSet &Classes;
1920 SourceLocation InstantiationLoc;
1925 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
1927 static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces,
1929 // Add the associated namespace for this class.
1931 // We don't use DeclContext::getEnclosingNamespaceContext() as this may
1932 // be a locally scoped record.
1934 // We skip out of inline namespaces. The innermost non-inline namespace
1935 // contains all names of all its nested inline namespaces anyway, so we can
1936 // replace the entire inline namespace tree with its root.
1937 while (Ctx->isRecord() || Ctx->isTransparentContext() ||
1938 Ctx->isInlineNamespace())
1939 Ctx = Ctx->getParent();
1941 if (Ctx->isFileContext())
1942 Namespaces.insert(Ctx->getPrimaryContext());
1945 // \brief Add the associated classes and namespaces for argument-dependent
1946 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2).
1948 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
1949 const TemplateArgument &Arg) {
1950 // C++ [basic.lookup.koenig]p2, last bullet:
1952 switch (Arg.getKind()) {
1953 case TemplateArgument::Null:
1956 case TemplateArgument::Type:
1957 // [...] the namespaces and classes associated with the types of the
1958 // template arguments provided for template type parameters (excluding
1959 // template template parameters)
1960 addAssociatedClassesAndNamespaces(Result, Arg.getAsType());
1963 case TemplateArgument::Template:
1964 case TemplateArgument::TemplateExpansion: {
1965 // [...] the namespaces in which any template template arguments are
1966 // defined; and the classes in which any member templates used as
1967 // template template arguments are defined.
1968 TemplateName Template = Arg.getAsTemplateOrTemplatePattern();
1969 if (ClassTemplateDecl *ClassTemplate
1970 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
1971 DeclContext *Ctx = ClassTemplate->getDeclContext();
1972 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1973 Result.Classes.insert(EnclosingClass);
1974 // Add the associated namespace for this class.
1975 CollectEnclosingNamespace(Result.Namespaces, Ctx);
1980 case TemplateArgument::Declaration:
1981 case TemplateArgument::Integral:
1982 case TemplateArgument::Expression:
1983 case TemplateArgument::NullPtr:
1984 // [Note: non-type template arguments do not contribute to the set of
1985 // associated namespaces. ]
1988 case TemplateArgument::Pack:
1989 for (const auto &P : Arg.pack_elements())
1990 addAssociatedClassesAndNamespaces(Result, P);
1995 // \brief Add the associated classes and namespaces for
1996 // argument-dependent lookup with an argument of class type
1997 // (C++ [basic.lookup.koenig]p2).
1999 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2000 CXXRecordDecl *Class) {
2002 // Just silently ignore anything whose name is __va_list_tag.
2003 if (Class->getDeclName() == Result.S.VAListTagName)
2006 // C++ [basic.lookup.koenig]p2:
2008 // -- If T is a class type (including unions), its associated
2009 // classes are: the class itself; the class of which it is a
2010 // member, if any; and its direct and indirect base
2011 // classes. Its associated namespaces are the namespaces in
2012 // which its associated classes are defined.
2014 // Add the class of which it is a member, if any.
2015 DeclContext *Ctx = Class->getDeclContext();
2016 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2017 Result.Classes.insert(EnclosingClass);
2018 // Add the associated namespace for this class.
2019 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2021 // Add the class itself. If we've already seen this class, we don't
2022 // need to visit base classes.
2024 // FIXME: That's not correct, we may have added this class only because it
2025 // was the enclosing class of another class, and in that case we won't have
2026 // added its base classes yet.
2027 if (!Result.Classes.insert(Class))
2030 // -- If T is a template-id, its associated namespaces and classes are
2031 // the namespace in which the template is defined; for member
2032 // templates, the member template's class; the namespaces and classes
2033 // associated with the types of the template arguments provided for
2034 // template type parameters (excluding template template parameters); the
2035 // namespaces in which any template template arguments are defined; and
2036 // the classes in which any member templates used as template template
2037 // arguments are defined. [Note: non-type template arguments do not
2038 // contribute to the set of associated namespaces. ]
2039 if (ClassTemplateSpecializationDecl *Spec
2040 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
2041 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
2042 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2043 Result.Classes.insert(EnclosingClass);
2044 // Add the associated namespace for this class.
2045 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2047 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
2048 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2049 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]);
2052 // Only recurse into base classes for complete types.
2053 if (!Class->hasDefinition())
2056 // Add direct and indirect base classes along with their associated
2058 SmallVector<CXXRecordDecl *, 32> Bases;
2059 Bases.push_back(Class);
2060 while (!Bases.empty()) {
2061 // Pop this class off the stack.
2062 Class = Bases.pop_back_val();
2064 // Visit the base classes.
2065 for (const auto &Base : Class->bases()) {
2066 const RecordType *BaseType = Base.getType()->getAs<RecordType>();
2067 // In dependent contexts, we do ADL twice, and the first time around,
2068 // the base type might be a dependent TemplateSpecializationType, or a
2069 // TemplateTypeParmType. If that happens, simply ignore it.
2070 // FIXME: If we want to support export, we probably need to add the
2071 // namespace of the template in a TemplateSpecializationType, or even
2072 // the classes and namespaces of known non-dependent arguments.
2075 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
2076 if (Result.Classes.insert(BaseDecl)) {
2077 // Find the associated namespace for this base class.
2078 DeclContext *BaseCtx = BaseDecl->getDeclContext();
2079 CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
2081 // Make sure we visit the bases of this base class.
2082 if (BaseDecl->bases_begin() != BaseDecl->bases_end())
2083 Bases.push_back(BaseDecl);
2089 // \brief Add the associated classes and namespaces for
2090 // argument-dependent lookup with an argument of type T
2091 // (C++ [basic.lookup.koenig]p2).
2093 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
2094 // C++ [basic.lookup.koenig]p2:
2096 // For each argument type T in the function call, there is a set
2097 // of zero or more associated namespaces and a set of zero or more
2098 // associated classes to be considered. The sets of namespaces and
2099 // classes is determined entirely by the types of the function
2100 // arguments (and the namespace of any template template
2101 // argument). Typedef names and using-declarations used to specify
2102 // the types do not contribute to this set. The sets of namespaces
2103 // and classes are determined in the following way:
2105 SmallVector<const Type *, 16> Queue;
2106 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
2109 switch (T->getTypeClass()) {
2111 #define TYPE(Class, Base)
2112 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
2113 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
2114 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
2115 #define ABSTRACT_TYPE(Class, Base)
2116 #include "clang/AST/TypeNodes.def"
2117 // T is canonical. We can also ignore dependent types because
2118 // we don't need to do ADL at the definition point, but if we
2119 // wanted to implement template export (or if we find some other
2120 // use for associated classes and namespaces...) this would be
2124 // -- If T is a pointer to U or an array of U, its associated
2125 // namespaces and classes are those associated with U.
2127 T = cast<PointerType>(T)->getPointeeType().getTypePtr();
2129 case Type::ConstantArray:
2130 case Type::IncompleteArray:
2131 case Type::VariableArray:
2132 T = cast<ArrayType>(T)->getElementType().getTypePtr();
2135 // -- If T is a fundamental type, its associated sets of
2136 // namespaces and classes are both empty.
2140 // -- If T is a class type (including unions), its associated
2141 // classes are: the class itself; the class of which it is a
2142 // member, if any; and its direct and indirect base
2143 // classes. Its associated namespaces are the namespaces in
2144 // which its associated classes are defined.
2145 case Type::Record: {
2146 Result.S.RequireCompleteType(Result.InstantiationLoc, QualType(T, 0),
2147 /*no diagnostic*/ 0);
2148 CXXRecordDecl *Class
2149 = cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl());
2150 addAssociatedClassesAndNamespaces(Result, Class);
2154 // -- If T is an enumeration type, its associated namespace is
2155 // the namespace in which it is defined. If it is class
2156 // member, its associated class is the member's class; else
2157 // it has no associated class.
2159 EnumDecl *Enum = cast<EnumType>(T)->getDecl();
2161 DeclContext *Ctx = Enum->getDeclContext();
2162 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2163 Result.Classes.insert(EnclosingClass);
2165 // Add the associated namespace for this class.
2166 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2171 // -- If T is a function type, its associated namespaces and
2172 // classes are those associated with the function parameter
2173 // types and those associated with the return type.
2174 case Type::FunctionProto: {
2175 const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
2176 for (const auto &Arg : Proto->param_types())
2177 Queue.push_back(Arg.getTypePtr());
2180 case Type::FunctionNoProto: {
2181 const FunctionType *FnType = cast<FunctionType>(T);
2182 T = FnType->getReturnType().getTypePtr();
2186 // -- If T is a pointer to a member function of a class X, its
2187 // associated namespaces and classes are those associated
2188 // with the function parameter types and return type,
2189 // together with those associated with X.
2191 // -- If T is a pointer to a data member of class X, its
2192 // associated namespaces and classes are those associated
2193 // with the member type together with those associated with
2195 case Type::MemberPointer: {
2196 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T);
2198 // Queue up the class type into which this points.
2199 Queue.push_back(MemberPtr->getClass());
2201 // And directly continue with the pointee type.
2202 T = MemberPtr->getPointeeType().getTypePtr();
2206 // As an extension, treat this like a normal pointer.
2207 case Type::BlockPointer:
2208 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr();
2211 // References aren't covered by the standard, but that's such an
2212 // obvious defect that we cover them anyway.
2213 case Type::LValueReference:
2214 case Type::RValueReference:
2215 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr();
2218 // These are fundamental types.
2220 case Type::ExtVector:
2224 // Non-deduced auto types only get here for error cases.
2228 // If T is an Objective-C object or interface type, or a pointer to an
2229 // object or interface type, the associated namespace is the global
2231 case Type::ObjCObject:
2232 case Type::ObjCInterface:
2233 case Type::ObjCObjectPointer:
2234 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
2237 // Atomic types are just wrappers; use the associations of the
2240 T = cast<AtomicType>(T)->getValueType().getTypePtr();
2246 T = Queue.pop_back_val();
2250 /// \brief Find the associated classes and namespaces for
2251 /// argument-dependent lookup for a call with the given set of
2254 /// This routine computes the sets of associated classes and associated
2255 /// namespaces searched by argument-dependent lookup
2256 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
2257 void Sema::FindAssociatedClassesAndNamespaces(
2258 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
2259 AssociatedNamespaceSet &AssociatedNamespaces,
2260 AssociatedClassSet &AssociatedClasses) {
2261 AssociatedNamespaces.clear();
2262 AssociatedClasses.clear();
2264 AssociatedLookup Result(*this, InstantiationLoc,
2265 AssociatedNamespaces, AssociatedClasses);
2267 // C++ [basic.lookup.koenig]p2:
2268 // For each argument type T in the function call, there is a set
2269 // of zero or more associated namespaces and a set of zero or more
2270 // associated classes to be considered. The sets of namespaces and
2271 // classes is determined entirely by the types of the function
2272 // arguments (and the namespace of any template template
2274 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
2275 Expr *Arg = Args[ArgIdx];
2277 if (Arg->getType() != Context.OverloadTy) {
2278 addAssociatedClassesAndNamespaces(Result, Arg->getType());
2282 // [...] In addition, if the argument is the name or address of a
2283 // set of overloaded functions and/or function templates, its
2284 // associated classes and namespaces are the union of those
2285 // associated with each of the members of the set: the namespace
2286 // in which the function or function template is defined and the
2287 // classes and namespaces associated with its (non-dependent)
2288 // parameter types and return type.
2289 Arg = Arg->IgnoreParens();
2290 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg))
2291 if (unaryOp->getOpcode() == UO_AddrOf)
2292 Arg = unaryOp->getSubExpr();
2294 UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg);
2297 for (const auto *D : ULE->decls()) {
2298 // Look through any using declarations to find the underlying function.
2299 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
2301 // Add the classes and namespaces associated with the parameter
2302 // types and return type of this function.
2303 addAssociatedClassesAndNamespaces(Result, FDecl->getType());
2308 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
2310 LookupNameKind NameKind,
2311 RedeclarationKind Redecl) {
2312 LookupResult R(*this, Name, Loc, NameKind, Redecl);
2314 return R.getAsSingle<NamedDecl>();
2317 /// \brief Find the protocol with the given name, if any.
2318 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II,
2319 SourceLocation IdLoc,
2320 RedeclarationKind Redecl) {
2321 Decl *D = LookupSingleName(TUScope, II, IdLoc,
2322 LookupObjCProtocolName, Redecl);
2323 return cast_or_null<ObjCProtocolDecl>(D);
2326 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
2327 QualType T1, QualType T2,
2328 UnresolvedSetImpl &Functions) {
2329 // C++ [over.match.oper]p3:
2330 // -- The set of non-member candidates is the result of the
2331 // unqualified lookup of operator@ in the context of the
2332 // expression according to the usual rules for name lookup in
2333 // unqualified function calls (3.4.2) except that all member
2334 // functions are ignored.
2335 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
2336 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
2337 LookupName(Operators, S);
2339 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
2340 Functions.append(Operators.begin(), Operators.end());
2343 Sema::SpecialMemberOverloadResult *Sema::LookupSpecialMember(CXXRecordDecl *RD,
2344 CXXSpecialMember SM,
2349 bool VolatileThis) {
2350 assert(CanDeclareSpecialMemberFunction(RD) &&
2351 "doing special member lookup into record that isn't fully complete");
2352 RD = RD->getDefinition();
2353 if (RValueThis || ConstThis || VolatileThis)
2354 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) &&
2355 "constructors and destructors always have unqualified lvalue this");
2356 if (ConstArg || VolatileArg)
2357 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) &&
2358 "parameter-less special members can't have qualified arguments");
2360 llvm::FoldingSetNodeID ID;
2363 ID.AddInteger(ConstArg);
2364 ID.AddInteger(VolatileArg);
2365 ID.AddInteger(RValueThis);
2366 ID.AddInteger(ConstThis);
2367 ID.AddInteger(VolatileThis);
2370 SpecialMemberOverloadResult *Result =
2371 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
2373 // This was already cached
2377 Result = BumpAlloc.Allocate<SpecialMemberOverloadResult>();
2378 Result = new (Result) SpecialMemberOverloadResult(ID);
2379 SpecialMemberCache.InsertNode(Result, InsertPoint);
2381 if (SM == CXXDestructor) {
2382 if (RD->needsImplicitDestructor())
2383 DeclareImplicitDestructor(RD);
2384 CXXDestructorDecl *DD = RD->getDestructor();
2385 assert(DD && "record without a destructor");
2386 Result->setMethod(DD);
2387 Result->setKind(DD->isDeleted() ?
2388 SpecialMemberOverloadResult::NoMemberOrDeleted :
2389 SpecialMemberOverloadResult::Success);
2393 // Prepare for overload resolution. Here we construct a synthetic argument
2394 // if necessary and make sure that implicit functions are declared.
2395 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD));
2396 DeclarationName Name;
2397 Expr *Arg = nullptr;
2400 QualType ArgType = CanTy;
2401 ExprValueKind VK = VK_LValue;
2403 if (SM == CXXDefaultConstructor) {
2404 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2406 if (RD->needsImplicitDefaultConstructor())
2407 DeclareImplicitDefaultConstructor(RD);
2409 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) {
2410 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2411 if (RD->needsImplicitCopyConstructor())
2412 DeclareImplicitCopyConstructor(RD);
2413 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor())
2414 DeclareImplicitMoveConstructor(RD);
2416 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
2417 if (RD->needsImplicitCopyAssignment())
2418 DeclareImplicitCopyAssignment(RD);
2419 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment())
2420 DeclareImplicitMoveAssignment(RD);
2426 ArgType.addVolatile();
2428 // This isn't /really/ specified by the standard, but it's implied
2429 // we should be working from an RValue in the case of move to ensure
2430 // that we prefer to bind to rvalue references, and an LValue in the
2431 // case of copy to ensure we don't bind to rvalue references.
2432 // Possibly an XValue is actually correct in the case of move, but
2433 // there is no semantic difference for class types in this restricted
2435 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment)
2441 OpaqueValueExpr FakeArg(SourceLocation(), ArgType, VK);
2443 if (SM != CXXDefaultConstructor) {
2448 // Create the object argument
2449 QualType ThisTy = CanTy;
2453 ThisTy.addVolatile();
2454 Expr::Classification Classification =
2455 OpaqueValueExpr(SourceLocation(), ThisTy,
2456 RValueThis ? VK_RValue : VK_LValue).Classify(Context);
2458 // Now we perform lookup on the name we computed earlier and do overload
2459 // resolution. Lookup is only performed directly into the class since there
2460 // will always be a (possibly implicit) declaration to shadow any others.
2461 OverloadCandidateSet OCS(RD->getLocation(), OverloadCandidateSet::CSK_Normal);
2462 DeclContext::lookup_result R = RD->lookup(Name);
2463 assert(!R.empty() &&
2464 "lookup for a constructor or assignment operator was empty");
2466 // Copy the candidates as our processing of them may load new declarations
2467 // from an external source and invalidate lookup_result.
2468 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
2470 for (auto *Cand : Candidates) {
2471 if (Cand->isInvalidDecl())
2474 if (UsingShadowDecl *U = dyn_cast<UsingShadowDecl>(Cand)) {
2475 // FIXME: [namespace.udecl]p15 says that we should only consider a
2476 // using declaration here if it does not match a declaration in the
2477 // derived class. We do not implement this correctly in other cases
2479 Cand = U->getTargetDecl();
2481 if (Cand->isInvalidDecl())
2485 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand)) {
2486 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2487 AddMethodCandidate(M, DeclAccessPair::make(M, AS_public), RD, ThisTy,
2488 Classification, llvm::makeArrayRef(&Arg, NumArgs),
2491 AddOverloadCandidate(M, DeclAccessPair::make(M, AS_public),
2492 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2493 } else if (FunctionTemplateDecl *Tmpl =
2494 dyn_cast<FunctionTemplateDecl>(Cand)) {
2495 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2496 AddMethodTemplateCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public),
2497 RD, nullptr, ThisTy, Classification,
2498 llvm::makeArrayRef(&Arg, NumArgs),
2501 AddTemplateOverloadCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public),
2502 nullptr, llvm::makeArrayRef(&Arg, NumArgs),
2505 assert(isa<UsingDecl>(Cand) && "illegal Kind of operator = Decl");
2509 OverloadCandidateSet::iterator Best;
2510 switch (OCS.BestViableFunction(*this, SourceLocation(), Best)) {
2512 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
2513 Result->setKind(SpecialMemberOverloadResult::Success);
2517 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
2518 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2522 Result->setMethod(nullptr);
2523 Result->setKind(SpecialMemberOverloadResult::Ambiguous);
2526 case OR_No_Viable_Function:
2527 Result->setMethod(nullptr);
2528 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2535 /// \brief Look up the default constructor for the given class.
2536 CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) {
2537 SpecialMemberOverloadResult *Result =
2538 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false,
2541 return cast_or_null<CXXConstructorDecl>(Result->getMethod());
2544 /// \brief Look up the copying constructor for the given class.
2545 CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class,
2547 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
2548 "non-const, non-volatile qualifiers for copy ctor arg");
2549 SpecialMemberOverloadResult *Result =
2550 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const,
2551 Quals & Qualifiers::Volatile, false, false, false);
2553 return cast_or_null<CXXConstructorDecl>(Result->getMethod());
2556 /// \brief Look up the moving constructor for the given class.
2557 CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class,
2559 SpecialMemberOverloadResult *Result =
2560 LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const,
2561 Quals & Qualifiers::Volatile, false, false, false);
2563 return cast_or_null<CXXConstructorDecl>(Result->getMethod());
2566 /// \brief Look up the constructors for the given class.
2567 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) {
2568 // If the implicit constructors have not yet been declared, do so now.
2569 if (CanDeclareSpecialMemberFunction(Class)) {
2570 if (Class->needsImplicitDefaultConstructor())
2571 DeclareImplicitDefaultConstructor(Class);
2572 if (Class->needsImplicitCopyConstructor())
2573 DeclareImplicitCopyConstructor(Class);
2574 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
2575 DeclareImplicitMoveConstructor(Class);
2578 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class));
2579 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T);
2580 return Class->lookup(Name);
2583 /// \brief Look up the copying assignment operator for the given class.
2584 CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class,
2585 unsigned Quals, bool RValueThis,
2586 unsigned ThisQuals) {
2587 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
2588 "non-const, non-volatile qualifiers for copy assignment arg");
2589 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
2590 "non-const, non-volatile qualifiers for copy assignment this");
2591 SpecialMemberOverloadResult *Result =
2592 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const,
2593 Quals & Qualifiers::Volatile, RValueThis,
2594 ThisQuals & Qualifiers::Const,
2595 ThisQuals & Qualifiers::Volatile);
2597 return Result->getMethod();
2600 /// \brief Look up the moving assignment operator for the given class.
2601 CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class,
2604 unsigned ThisQuals) {
2605 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
2606 "non-const, non-volatile qualifiers for copy assignment this");
2607 SpecialMemberOverloadResult *Result =
2608 LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const,
2609 Quals & Qualifiers::Volatile, RValueThis,
2610 ThisQuals & Qualifiers::Const,
2611 ThisQuals & Qualifiers::Volatile);
2613 return Result->getMethod();
2616 /// \brief Look for the destructor of the given class.
2618 /// During semantic analysis, this routine should be used in lieu of
2619 /// CXXRecordDecl::getDestructor().
2621 /// \returns The destructor for this class.
2622 CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) {
2623 return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor,
2624 false, false, false,
2625 false, false)->getMethod());
2628 /// LookupLiteralOperator - Determine which literal operator should be used for
2629 /// a user-defined literal, per C++11 [lex.ext].
2631 /// Normal overload resolution is not used to select which literal operator to
2632 /// call for a user-defined literal. Look up the provided literal operator name,
2633 /// and filter the results to the appropriate set for the given argument types.
2634 Sema::LiteralOperatorLookupResult
2635 Sema::LookupLiteralOperator(Scope *S, LookupResult &R,
2636 ArrayRef<QualType> ArgTys,
2637 bool AllowRaw, bool AllowTemplate,
2638 bool AllowStringTemplate) {
2640 assert(R.getResultKind() != LookupResult::Ambiguous &&
2641 "literal operator lookup can't be ambiguous");
2643 // Filter the lookup results appropriately.
2644 LookupResult::Filter F = R.makeFilter();
2646 bool FoundRaw = false;
2647 bool FoundTemplate = false;
2648 bool FoundStringTemplate = false;
2649 bool FoundExactMatch = false;
2651 while (F.hasNext()) {
2653 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
2654 D = USD->getTargetDecl();
2656 // If the declaration we found is invalid, skip it.
2657 if (D->isInvalidDecl()) {
2663 bool IsTemplate = false;
2664 bool IsStringTemplate = false;
2665 bool IsExactMatch = false;
2667 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
2668 if (FD->getNumParams() == 1 &&
2669 FD->getParamDecl(0)->getType()->getAs<PointerType>())
2671 else if (FD->getNumParams() == ArgTys.size()) {
2672 IsExactMatch = true;
2673 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
2674 QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
2675 if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
2676 IsExactMatch = false;
2682 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) {
2683 TemplateParameterList *Params = FD->getTemplateParameters();
2684 if (Params->size() == 1)
2687 IsStringTemplate = true;
2691 FoundExactMatch = true;
2693 AllowTemplate = false;
2694 AllowStringTemplate = false;
2695 if (FoundRaw || FoundTemplate || FoundStringTemplate) {
2696 // Go through again and remove the raw and template decls we've
2699 FoundRaw = FoundTemplate = FoundStringTemplate = false;
2701 } else if (AllowRaw && IsRaw) {
2703 } else if (AllowTemplate && IsTemplate) {
2704 FoundTemplate = true;
2705 } else if (AllowStringTemplate && IsStringTemplate) {
2706 FoundStringTemplate = true;
2714 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
2715 // parameter type, that is used in preference to a raw literal operator
2716 // or literal operator template.
2717 if (FoundExactMatch)
2720 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
2721 // operator template, but not both.
2722 if (FoundRaw && FoundTemplate) {
2723 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
2724 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
2725 NoteOverloadCandidate((*I)->getUnderlyingDecl()->getAsFunction());
2733 return LOLR_Template;
2735 if (FoundStringTemplate)
2736 return LOLR_StringTemplate;
2738 // Didn't find anything we could use.
2739 Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
2740 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
2741 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
2742 << (AllowTemplate || AllowStringTemplate);
2746 void ADLResult::insert(NamedDecl *New) {
2747 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
2749 // If we haven't yet seen a decl for this key, or the last decl
2750 // was exactly this one, we're done.
2751 if (Old == nullptr || Old == New) {
2756 // Otherwise, decide which is a more recent redeclaration.
2757 FunctionDecl *OldFD = Old->getAsFunction();
2758 FunctionDecl *NewFD = New->getAsFunction();
2760 FunctionDecl *Cursor = NewFD;
2762 Cursor = Cursor->getPreviousDecl();
2764 // If we got to the end without finding OldFD, OldFD is the newer
2765 // declaration; leave things as they are.
2766 if (!Cursor) return;
2768 // If we do find OldFD, then NewFD is newer.
2769 if (Cursor == OldFD) break;
2771 // Otherwise, keep looking.
2777 void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
2778 ArrayRef<Expr *> Args, ADLResult &Result) {
2779 // Find all of the associated namespaces and classes based on the
2780 // arguments we have.
2781 AssociatedNamespaceSet AssociatedNamespaces;
2782 AssociatedClassSet AssociatedClasses;
2783 FindAssociatedClassesAndNamespaces(Loc, Args,
2784 AssociatedNamespaces,
2787 // C++ [basic.lookup.argdep]p3:
2788 // Let X be the lookup set produced by unqualified lookup (3.4.1)
2789 // and let Y be the lookup set produced by argument dependent
2790 // lookup (defined as follows). If X contains [...] then Y is
2791 // empty. Otherwise Y is the set of declarations found in the
2792 // namespaces associated with the argument types as described
2793 // below. The set of declarations found by the lookup of the name
2794 // is the union of X and Y.
2796 // Here, we compute Y and add its members to the overloaded
2798 for (auto *NS : AssociatedNamespaces) {
2799 // When considering an associated namespace, the lookup is the
2800 // same as the lookup performed when the associated namespace is
2801 // used as a qualifier (3.4.3.2) except that:
2803 // -- Any using-directives in the associated namespace are
2806 // -- Any namespace-scope friend functions declared in
2807 // associated classes are visible within their respective
2808 // namespaces even if they are not visible during an ordinary
2810 DeclContext::lookup_result R = NS->lookup(Name);
2812 // If the only declaration here is an ordinary friend, consider
2813 // it only if it was declared in an associated classes.
2814 if ((D->getIdentifierNamespace() & Decl::IDNS_Ordinary) == 0) {
2815 // If it's neither ordinarily visible nor a friend, we can't find it.
2816 if ((D->getIdentifierNamespace() & Decl::IDNS_OrdinaryFriend) == 0)
2819 bool DeclaredInAssociatedClass = false;
2820 for (Decl *DI = D; DI; DI = DI->getPreviousDecl()) {
2821 DeclContext *LexDC = DI->getLexicalDeclContext();
2822 if (isa<CXXRecordDecl>(LexDC) &&
2823 AssociatedClasses.count(cast<CXXRecordDecl>(LexDC))) {
2824 DeclaredInAssociatedClass = true;
2828 if (!DeclaredInAssociatedClass)
2832 if (isa<UsingShadowDecl>(D))
2833 D = cast<UsingShadowDecl>(D)->getTargetDecl();
2835 if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D))
2843 //----------------------------------------------------------------------------
2844 // Search for all visible declarations.
2845 //----------------------------------------------------------------------------
2846 VisibleDeclConsumer::~VisibleDeclConsumer() { }
2848 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
2852 class ShadowContextRAII;
2854 class VisibleDeclsRecord {
2856 /// \brief An entry in the shadow map, which is optimized to store a
2857 /// single declaration (the common case) but can also store a list
2858 /// of declarations.
2859 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
2862 /// \brief A mapping from declaration names to the declarations that have
2863 /// this name within a particular scope.
2864 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
2866 /// \brief A list of shadow maps, which is used to model name hiding.
2867 std::list<ShadowMap> ShadowMaps;
2869 /// \brief The declaration contexts we have already visited.
2870 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
2872 friend class ShadowContextRAII;
2875 /// \brief Determine whether we have already visited this context
2876 /// (and, if not, note that we are going to visit that context now).
2877 bool visitedContext(DeclContext *Ctx) {
2878 return !VisitedContexts.insert(Ctx);
2881 bool alreadyVisitedContext(DeclContext *Ctx) {
2882 return VisitedContexts.count(Ctx);
2885 /// \brief Determine whether the given declaration is hidden in the
2888 /// \returns the declaration that hides the given declaration, or
2889 /// NULL if no such declaration exists.
2890 NamedDecl *checkHidden(NamedDecl *ND);
2892 /// \brief Add a declaration to the current shadow map.
2893 void add(NamedDecl *ND) {
2894 ShadowMaps.back()[ND->getDeclName()].push_back(ND);
2898 /// \brief RAII object that records when we've entered a shadow context.
2899 class ShadowContextRAII {
2900 VisibleDeclsRecord &Visible;
2902 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
2905 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
2906 Visible.ShadowMaps.push_back(ShadowMap());
2909 ~ShadowContextRAII() {
2910 Visible.ShadowMaps.pop_back();
2914 } // end anonymous namespace
2916 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
2917 // Look through using declarations.
2918 ND = ND->getUnderlyingDecl();
2920 unsigned IDNS = ND->getIdentifierNamespace();
2921 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
2922 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
2923 SM != SMEnd; ++SM) {
2924 ShadowMap::iterator Pos = SM->find(ND->getDeclName());
2925 if (Pos == SM->end())
2928 for (auto *D : Pos->second) {
2929 // A tag declaration does not hide a non-tag declaration.
2930 if (D->hasTagIdentifierNamespace() &&
2931 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
2932 Decl::IDNS_ObjCProtocol)))
2935 // Protocols are in distinct namespaces from everything else.
2936 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
2937 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
2938 D->getIdentifierNamespace() != IDNS)
2941 // Functions and function templates in the same scope overload
2942 // rather than hide. FIXME: Look for hiding based on function
2944 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
2945 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
2946 SM == ShadowMaps.rbegin())
2949 // We've found a declaration that hides this one.
2957 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
2958 bool QualifiedNameLookup,
2960 VisibleDeclConsumer &Consumer,
2961 VisibleDeclsRecord &Visited) {
2965 // Make sure we don't visit the same context twice.
2966 if (Visited.visitedContext(Ctx->getPrimaryContext()))
2969 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
2970 Result.getSema().ForceDeclarationOfImplicitMembers(Class);
2972 // Enumerate all of the results in this context.
2973 for (const auto &R : Ctx->lookups()) {
2975 if (NamedDecl *ND = dyn_cast<NamedDecl>(I)) {
2976 if ((ND = Result.getAcceptableDecl(ND))) {
2977 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
2984 // Traverse using directives for qualified name lookup.
2985 if (QualifiedNameLookup) {
2986 ShadowContextRAII Shadow(Visited);
2987 for (auto I : Ctx->using_directives()) {
2988 LookupVisibleDecls(I->getNominatedNamespace(), Result,
2989 QualifiedNameLookup, InBaseClass, Consumer, Visited);
2993 // Traverse the contexts of inherited C++ classes.
2994 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
2995 if (!Record->hasDefinition())
2998 for (const auto &B : Record->bases()) {
2999 QualType BaseType = B.getType();
3001 // Don't look into dependent bases, because name lookup can't look
3003 if (BaseType->isDependentType())
3006 const RecordType *Record = BaseType->getAs<RecordType>();
3010 // FIXME: It would be nice to be able to determine whether referencing
3011 // a particular member would be ambiguous. For example, given
3013 // struct A { int member; };
3014 // struct B { int member; };
3015 // struct C : A, B { };
3017 // void f(C *c) { c->### }
3019 // accessing 'member' would result in an ambiguity. However, we
3020 // could be smart enough to qualify the member with the base
3029 // Find results in this base class (and its bases).
3030 ShadowContextRAII Shadow(Visited);
3031 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup,
3032 true, Consumer, Visited);
3036 // Traverse the contexts of Objective-C classes.
3037 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
3038 // Traverse categories.
3039 for (auto *Cat : IFace->visible_categories()) {
3040 ShadowContextRAII Shadow(Visited);
3041 LookupVisibleDecls(Cat, Result, QualifiedNameLookup, false,
3045 // Traverse protocols.
3046 for (auto *I : IFace->all_referenced_protocols()) {
3047 ShadowContextRAII Shadow(Visited);
3048 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3052 // Traverse the superclass.
3053 if (IFace->getSuperClass()) {
3054 ShadowContextRAII Shadow(Visited);
3055 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup,
3056 true, Consumer, Visited);
3059 // If there is an implementation, traverse it. We do this to find
3060 // synthesized ivars.
3061 if (IFace->getImplementation()) {
3062 ShadowContextRAII Shadow(Visited);
3063 LookupVisibleDecls(IFace->getImplementation(), Result,
3064 QualifiedNameLookup, InBaseClass, Consumer, Visited);
3066 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
3067 for (auto *I : Protocol->protocols()) {
3068 ShadowContextRAII Shadow(Visited);
3069 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3072 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
3073 for (auto *I : Category->protocols()) {
3074 ShadowContextRAII Shadow(Visited);
3075 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3079 // If there is an implementation, traverse it.
3080 if (Category->getImplementation()) {
3081 ShadowContextRAII Shadow(Visited);
3082 LookupVisibleDecls(Category->getImplementation(), Result,
3083 QualifiedNameLookup, true, Consumer, Visited);
3088 static void LookupVisibleDecls(Scope *S, LookupResult &Result,
3089 UnqualUsingDirectiveSet &UDirs,
3090 VisibleDeclConsumer &Consumer,
3091 VisibleDeclsRecord &Visited) {
3095 if (!S->getEntity() ||
3097 !Visited.alreadyVisitedContext(S->getEntity())) ||
3098 (S->getEntity())->isFunctionOrMethod()) {
3099 FindLocalExternScope FindLocals(Result);
3100 // Walk through the declarations in this Scope.
3101 for (auto *D : S->decls()) {
3102 if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
3103 if ((ND = Result.getAcceptableDecl(ND))) {
3104 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
3110 // FIXME: C++ [temp.local]p8
3111 DeclContext *Entity = nullptr;
3112 if (S->getEntity()) {
3113 // Look into this scope's declaration context, along with any of its
3114 // parent lookup contexts (e.g., enclosing classes), up to the point
3115 // where we hit the context stored in the next outer scope.
3116 Entity = S->getEntity();
3117 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME
3119 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
3120 Ctx = Ctx->getLookupParent()) {
3121 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
3122 if (Method->isInstanceMethod()) {
3123 // For instance methods, look for ivars in the method's interface.
3124 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
3125 Result.getNameLoc(), Sema::LookupMemberName);
3126 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
3127 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false,
3128 /*InBaseClass=*/false, Consumer, Visited);
3132 // We've already performed all of the name lookup that we need
3133 // to for Objective-C methods; the next context will be the
3138 if (Ctx->isFunctionOrMethod())
3141 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false,
3142 /*InBaseClass=*/false, Consumer, Visited);
3144 } else if (!S->getParent()) {
3145 // Look into the translation unit scope. We walk through the translation
3146 // unit's declaration context, because the Scope itself won't have all of
3147 // the declarations if we loaded a precompiled header.
3148 // FIXME: We would like the translation unit's Scope object to point to the
3149 // translation unit, so we don't need this special "if" branch. However,
3150 // doing so would force the normal C++ name-lookup code to look into the
3151 // translation unit decl when the IdentifierInfo chains would suffice.
3152 // Once we fix that problem (which is part of a more general "don't look
3153 // in DeclContexts unless we have to" optimization), we can eliminate this.
3154 Entity = Result.getSema().Context.getTranslationUnitDecl();
3155 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false,
3156 /*InBaseClass=*/false, Consumer, Visited);
3160 // Lookup visible declarations in any namespaces found by using
3162 UnqualUsingDirectiveSet::const_iterator UI, UEnd;
3163 std::tie(UI, UEnd) = UDirs.getNamespacesFor(Entity);
3164 for (; UI != UEnd; ++UI)
3165 LookupVisibleDecls(const_cast<DeclContext *>(UI->getNominatedNamespace()),
3166 Result, /*QualifiedNameLookup=*/false,
3167 /*InBaseClass=*/false, Consumer, Visited);
3170 // Lookup names in the parent scope.
3171 ShadowContextRAII Shadow(Visited);
3172 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited);
3175 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
3176 VisibleDeclConsumer &Consumer,
3177 bool IncludeGlobalScope) {
3178 // Determine the set of using directives available during
3179 // unqualified name lookup.
3181 UnqualUsingDirectiveSet UDirs;
3182 if (getLangOpts().CPlusPlus) {
3183 // Find the first namespace or translation-unit scope.
3184 while (S && !isNamespaceOrTranslationUnitScope(S))
3187 UDirs.visitScopeChain(Initial, S);
3191 // Look for visible declarations.
3192 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3193 Result.setAllowHidden(Consumer.includeHiddenDecls());
3194 VisibleDeclsRecord Visited;
3195 if (!IncludeGlobalScope)
3196 Visited.visitedContext(Context.getTranslationUnitDecl());
3197 ShadowContextRAII Shadow(Visited);
3198 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited);
3201 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
3202 VisibleDeclConsumer &Consumer,
3203 bool IncludeGlobalScope) {
3204 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3205 Result.setAllowHidden(Consumer.includeHiddenDecls());
3206 VisibleDeclsRecord Visited;
3207 if (!IncludeGlobalScope)
3208 Visited.visitedContext(Context.getTranslationUnitDecl());
3209 ShadowContextRAII Shadow(Visited);
3210 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true,
3211 /*InBaseClass=*/false, Consumer, Visited);
3214 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name.
3215 /// If GnuLabelLoc is a valid source location, then this is a definition
3216 /// of an __label__ label name, otherwise it is a normal label definition
3218 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc,
3219 SourceLocation GnuLabelLoc) {
3220 // Do a lookup to see if we have a label with this name already.
3221 NamedDecl *Res = nullptr;
3223 if (GnuLabelLoc.isValid()) {
3224 // Local label definitions always shadow existing labels.
3225 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
3226 Scope *S = CurScope;
3227 PushOnScopeChains(Res, S, true);
3228 return cast<LabelDecl>(Res);
3231 // Not a GNU local label.
3232 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration);
3233 // If we found a label, check to see if it is in the same context as us.
3234 // When in a Block, we don't want to reuse a label in an enclosing function.
3235 if (Res && Res->getDeclContext() != CurContext)
3238 // If not forward referenced or defined already, create the backing decl.
3239 Res = LabelDecl::Create(Context, CurContext, Loc, II);
3240 Scope *S = CurScope->getFnParent();
3241 assert(S && "Not in a function?");
3242 PushOnScopeChains(Res, S, true);
3244 return cast<LabelDecl>(Res);
3247 //===----------------------------------------------------------------------===//
3249 //===----------------------------------------------------------------------===//
3251 static bool isCandidateViable(CorrectionCandidateCallback &CCC,
3252 TypoCorrection &Candidate) {
3253 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
3254 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
3257 static void LookupPotentialTypoResult(Sema &SemaRef,
3259 IdentifierInfo *Name,
3260 Scope *S, CXXScopeSpec *SS,
3261 DeclContext *MemberContext,
3262 bool EnteringContext,
3263 bool isObjCIvarLookup,
3266 // Fill the supplied vector with the IdentifierInfo pointers for each piece of
3267 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
3268 // fill the vector with the IdentifierInfo pointers for "foo" and "bar").
3269 static void getNestedNameSpecifierIdentifiers(
3270 NestedNameSpecifier *NNS,
3271 SmallVectorImpl<const IdentifierInfo*> &Identifiers) {
3272 if (NestedNameSpecifier *Prefix = NNS->getPrefix())
3273 getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
3275 Identifiers.clear();
3277 const IdentifierInfo *II = nullptr;
3279 switch (NNS->getKind()) {
3280 case NestedNameSpecifier::Identifier:
3281 II = NNS->getAsIdentifier();
3284 case NestedNameSpecifier::Namespace:
3285 if (NNS->getAsNamespace()->isAnonymousNamespace())
3287 II = NNS->getAsNamespace()->getIdentifier();
3290 case NestedNameSpecifier::NamespaceAlias:
3291 II = NNS->getAsNamespaceAlias()->getIdentifier();
3294 case NestedNameSpecifier::TypeSpecWithTemplate:
3295 case NestedNameSpecifier::TypeSpec:
3296 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier();
3299 case NestedNameSpecifier::Global:
3304 Identifiers.push_back(II);
3309 static const unsigned MaxTypoDistanceResultSets = 5;
3311 class TypoCorrectionConsumer : public VisibleDeclConsumer {
3312 typedef SmallVector<TypoCorrection, 1> TypoResultList;
3313 typedef llvm::StringMap<TypoResultList> TypoResultsMap;
3314 typedef std::map<unsigned, TypoResultsMap> TypoEditDistanceMap;
3317 explicit TypoCorrectionConsumer(Sema &SemaRef,
3318 const DeclarationNameInfo &TypoName,
3319 Sema::LookupNameKind LookupKind,
3320 Scope *S, CXXScopeSpec *SS,
3321 CorrectionCandidateCallback &CCC,
3322 DeclContext *MemberContext,
3323 bool EnteringContext)
3324 : Typo(TypoName.getName().getAsIdentifierInfo()), SemaRef(SemaRef), S(S),
3325 SS(SS), CorrectionValidator(CCC), MemberContext(MemberContext),
3326 Result(SemaRef, TypoName, LookupKind),
3327 Namespaces(SemaRef.Context, SemaRef.CurContext, SS),
3328 EnteringContext(EnteringContext), SearchNamespaces(false) {
3329 Result.suppressDiagnostics();
3332 bool includeHiddenDecls() const override { return true; }
3334 // Methods for adding potential corrections to the consumer.
3335 void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, DeclContext *Ctx,
3336 bool InBaseClass) override;
3337 void FoundName(StringRef Name);
3338 void addKeywordResult(StringRef Keyword);
3339 void addCorrection(TypoCorrection Correction);
3341 bool empty() const { return CorrectionResults.empty(); }
3343 /// \brief Return the list of TypoCorrections for the given identifier from
3344 /// the set of corrections that have the closest edit distance, if any.
3345 TypoResultList &operator[](StringRef Name) {
3346 return CorrectionResults.begin()->second[Name];
3349 /// \brief Return the edit distance of the corrections that have the
3350 /// closest/best edit distance from the original typop.
3351 unsigned getBestEditDistance(bool Normalized) {
3352 if (CorrectionResults.empty())
3353 return (std::numeric_limits<unsigned>::max)();
3355 unsigned BestED = CorrectionResults.begin()->first;
3356 return Normalized ? TypoCorrection::NormalizeEditDistance(BestED) : BestED;
3359 /// \brief Set-up method to add to the consumer the set of namespaces to use
3360 /// in performing corrections to nested name specifiers. This method also
3361 /// implicitly adds all of the known classes in the current AST context to the
3362 /// to the consumer for correcting nested name specifiers.
3364 addNamespaces(const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces);
3366 /// \brief Return the next typo correction that passes all internal filters
3367 /// and is deemed valid by the consumer's CorrectionCandidateCallback,
3368 /// starting with the corrections that have the closest edit distance. An
3369 /// empty TypoCorrection is returned once no more viable corrections remain
3370 /// in the consumer.
3371 TypoCorrection getNextCorrection();
3374 class NamespaceSpecifierSet {
3375 struct SpecifierInfo {
3376 DeclContext* DeclCtx;
3377 NestedNameSpecifier* NameSpecifier;
3378 unsigned EditDistance;
3381 typedef SmallVector<DeclContext*, 4> DeclContextList;
3382 typedef SmallVector<SpecifierInfo, 16> SpecifierInfoList;
3384 ASTContext &Context;
3385 DeclContextList CurContextChain;
3386 std::string CurNameSpecifier;
3387 SmallVector<const IdentifierInfo*, 4> CurContextIdentifiers;
3388 SmallVector<const IdentifierInfo*, 4> CurNameSpecifierIdentifiers;
3391 SpecifierInfoList Specifiers;
3392 llvm::SmallSetVector<unsigned, 4> Distances;
3393 llvm::DenseMap<unsigned, SpecifierInfoList> DistanceMap;
3395 /// \brief Helper for building the list of DeclContexts between the current
3396 /// context and the top of the translation unit
3397 static DeclContextList buildContextChain(DeclContext *Start);
3399 void sortNamespaces();
3401 unsigned buildNestedNameSpecifier(DeclContextList &DeclChain,
3402 NestedNameSpecifier *&NNS);
3405 NamespaceSpecifierSet(ASTContext &Context, DeclContext *CurContext,
3406 CXXScopeSpec *CurScopeSpec);
3408 /// \brief Add the DeclContext (a namespace or record) to the set, computing
3409 /// the corresponding NestedNameSpecifier and its distance in the process.
3410 void addNameSpecifier(DeclContext *Ctx);
3412 typedef SpecifierInfoList::iterator iterator;
3414 if (!isSorted) sortNamespaces();
3415 return Specifiers.begin();
3417 iterator end() { return Specifiers.end(); }
3420 void addName(StringRef Name, NamedDecl *ND,
3421 NestedNameSpecifier *NNS = nullptr, bool isKeyword = false);
3423 /// \brief Find any visible decls for the given typo correction candidate.
3424 /// If none are found, it to the set of candidates for which qualified lookups
3425 /// will be performed to find possible nested name specifier changes.
3426 bool resolveCorrection(TypoCorrection &Candidate);
3428 /// \brief Perform qualified lookups on the queued set of typo correction
3429 /// candidates and add the nested name specifier changes to each candidate if
3430 /// a lookup succeeds (at which point the candidate will be returned to the
3431 /// main pool of potential corrections).
3432 void performQualifiedLookups();
3434 /// \brief The name written that is a typo in the source.
3435 IdentifierInfo *Typo;
3437 /// \brief The results found that have the smallest edit distance
3438 /// found (so far) with the typo name.
3440 /// The pointer value being set to the current DeclContext indicates
3441 /// whether there is a keyword with this name.
3442 TypoEditDistanceMap CorrectionResults;
3447 CorrectionCandidateCallback &CorrectionValidator;
3448 DeclContext *MemberContext;
3449 LookupResult Result;
3450 NamespaceSpecifierSet Namespaces;
3451 SmallVector<TypoCorrection, 2> QualifiedResults;
3452 bool EnteringContext;
3453 bool SearchNamespaces;
3458 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
3459 DeclContext *Ctx, bool InBaseClass) {
3460 // Don't consider hidden names for typo correction.
3464 // Only consider entities with identifiers for names, ignoring
3465 // special names (constructors, overloaded operators, selectors,
3467 IdentifierInfo *Name = ND->getIdentifier();
3471 // Only consider visible declarations and declarations from modules with
3472 // names that exactly match.
3473 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo &&
3474 !findAcceptableDecl(SemaRef, ND))
3477 FoundName(Name->getName());
3480 void TypoCorrectionConsumer::FoundName(StringRef Name) {
3481 // Compute the edit distance between the typo and the name of this
3482 // entity, and add the identifier to the list of results.
3483 addName(Name, nullptr);
3486 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) {
3487 // Compute the edit distance between the typo and this keyword,
3488 // and add the keyword to the list of results.
3489 addName(Keyword, nullptr, nullptr, true);
3492 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
3493 NestedNameSpecifier *NNS, bool isKeyword) {
3494 // Use a simple length-based heuristic to determine the minimum possible
3495 // edit distance. If the minimum isn't good enough, bail out early.
3496 StringRef TypoStr = Typo->getName();
3497 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
3498 if (MinED && TypoStr.size() / MinED < 3)
3501 // Compute an upper bound on the allowable edit distance, so that the
3502 // edit-distance algorithm can short-circuit.
3503 unsigned UpperBound = (TypoStr.size() + 2) / 3 + 1;
3504 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
3505 if (ED >= UpperBound) return;
3507 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
3508 if (isKeyword) TC.makeKeyword();
3512 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) {
3513 StringRef TypoStr = Typo->getName();
3514 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
3516 // For very short typos, ignore potential corrections that have a different
3517 // base identifier from the typo or which have a normalized edit distance
3518 // longer than the typo itself.
3519 if (TypoStr.size() < 3 &&
3520 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
3523 // If the correction is resolved but is not viable, ignore it.
3524 if (Correction.isResolved() &&
3525 !isCandidateViable(CorrectionValidator, Correction))
3528 TypoResultList &CList =
3529 CorrectionResults[Correction.getEditDistance(false)][Name];
3531 if (!CList.empty() && !CList.back().isResolved())
3533 if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
3534 std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts());
3535 for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end();
3536 RI != RIEnd; ++RI) {
3537 // If the Correction refers to a decl already in the result list,
3538 // replace the existing result if the string representation of Correction
3539 // comes before the current result alphabetically, then stop as there is
3540 // nothing more to be done to add Correction to the candidate set.
3541 if (RI->getCorrectionDecl() == NewND) {
3542 if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts()))
3548 if (CList.empty() || Correction.isResolved())
3549 CList.push_back(Correction);
3551 while (CorrectionResults.size() > MaxTypoDistanceResultSets)
3552 CorrectionResults.erase(std::prev(CorrectionResults.end()));
3555 void TypoCorrectionConsumer::addNamespaces(
3556 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
3557 SearchNamespaces = true;
3559 for (auto KNPair : KnownNamespaces)
3560 Namespaces.addNameSpecifier(KNPair.first);
3562 bool SSIsTemplate = false;
3563 if (NestedNameSpecifier *NNS =
3564 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) {
3565 if (const Type *T = NNS->getAsType())
3566 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization;
3568 for (const auto *TI : SemaRef.getASTContext().types()) {
3569 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
3570 CD = CD->getCanonicalDecl();
3571 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
3572 !CD->isUnion() && CD->getIdentifier() &&
3573 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
3574 (CD->isBeingDefined() || CD->isCompleteDefinition()))
3575 Namespaces.addNameSpecifier(CD);
3580 TypoCorrection TypoCorrectionConsumer::getNextCorrection() {
3581 while (!CorrectionResults.empty()) {
3582 auto DI = CorrectionResults.begin();
3583 if (DI->second.empty()) {
3584 CorrectionResults.erase(DI);
3588 auto RI = DI->second.begin();
3589 if (RI->second.empty()) {
3590 DI->second.erase(RI);
3591 performQualifiedLookups();
3595 TypoCorrection TC = RI->second.pop_back_val();
3596 if (TC.isResolved() || resolveCorrection(TC))
3599 return TypoCorrection();
3602 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
3603 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
3604 DeclContext *TempMemberContext = MemberContext;
3605 CXXScopeSpec *TempSS = SS;
3607 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
3609 CorrectionValidator.IsObjCIvarLookup,
3610 Name == Typo && !Candidate.WillReplaceSpecifier());
3611 switch (Result.getResultKind()) {
3612 case LookupResult::NotFound:
3613 case LookupResult::NotFoundInCurrentInstantiation:
3614 case LookupResult::FoundUnresolvedValue:
3616 // Immediately retry the lookup without the given CXXScopeSpec
3618 Candidate.WillReplaceSpecifier(true);
3621 if (TempMemberContext) {
3624 TempMemberContext = nullptr;
3627 if (SearchNamespaces)
3628 QualifiedResults.push_back(Candidate);
3631 case LookupResult::Ambiguous:
3632 // We don't deal with ambiguities.
3635 case LookupResult::Found:
3636 case LookupResult::FoundOverloaded:
3637 // Store all of the Decls for overloaded symbols
3638 for (auto *TRD : Result)
3639 Candidate.addCorrectionDecl(TRD);
3640 if (!isCandidateViable(CorrectionValidator, Candidate)) {
3641 if (SearchNamespaces)
3642 QualifiedResults.push_back(Candidate);
3650 void TypoCorrectionConsumer::performQualifiedLookups() {
3651 unsigned TypoLen = Typo->getName().size();
3652 for (auto QR : QualifiedResults) {
3653 for (auto NSI : Namespaces) {
3654 DeclContext *Ctx = NSI.DeclCtx;
3655 const Type *NSType = NSI.NameSpecifier->getAsType();
3657 // If the current NestedNameSpecifier refers to a class and the
3658 // current correction candidate is the name of that class, then skip
3659 // it as it is unlikely a qualified version of the class' constructor
3660 // is an appropriate correction.
3661 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() : 0) {
3662 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
3666 TypoCorrection TC(QR);
3667 TC.ClearCorrectionDecls();
3668 TC.setCorrectionSpecifier(NSI.NameSpecifier);
3669 TC.setQualifierDistance(NSI.EditDistance);
3670 TC.setCallbackDistance(0); // Reset the callback distance
3672 // If the current correction candidate and namespace combination are
3673 // too far away from the original typo based on the normalized edit
3674 // distance, then skip performing a qualified name lookup.
3675 unsigned TmpED = TC.getEditDistance(true);
3676 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
3677 TypoLen / TmpED < 3)
3681 Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
3682 if (!SemaRef.LookupQualifiedName(Result, Ctx))
3685 // Any corrections added below will be validated in subsequent
3686 // iterations of the main while() loop over the Consumer's contents.
3687 switch (Result.getResultKind()) {
3688 case LookupResult::Found:
3689 case LookupResult::FoundOverloaded: {
3690 if (SS && SS->isValid()) {
3691 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
3692 std::string OldQualified;
3693 llvm::raw_string_ostream OldOStream(OldQualified);
3694 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy());
3695 OldOStream << Typo->getName();
3696 // If correction candidate would be an identical written qualified
3697 // identifer, then the existing CXXScopeSpec probably included a
3698 // typedef that didn't get accounted for properly.
3699 if (OldOStream.str() == NewQualified)
3702 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
3703 TRD != TRDEnd; ++TRD) {
3704 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
3705 NSType ? NSType->getAsCXXRecordDecl()
3707 TRD.getPair()) == Sema::AR_accessible)
3708 TC.addCorrectionDecl(*TRD);
3710 if (TC.isResolved())
3714 case LookupResult::NotFound:
3715 case LookupResult::NotFoundInCurrentInstantiation:
3716 case LookupResult::Ambiguous:
3717 case LookupResult::FoundUnresolvedValue:
3722 QualifiedResults.clear();
3725 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
3726 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
3727 : Context(Context), CurContextChain(buildContextChain(CurContext)),
3729 if (NestedNameSpecifier *NNS =
3730 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) {
3731 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
3732 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
3734 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
3736 // Build the list of identifiers that would be used for an absolute
3737 // (from the global context) NestedNameSpecifier referring to the current
3739 for (DeclContextList::reverse_iterator C = CurContextChain.rbegin(),
3740 CEnd = CurContextChain.rend();
3742 if (NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(*C))
3743 CurContextIdentifiers.push_back(ND->getIdentifier());
3746 // Add the global context as a NestedNameSpecifier
3747 Distances.insert(1);
3748 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
3749 NestedNameSpecifier::GlobalSpecifier(Context), 1};
3750 DistanceMap[1].push_back(SI);
3753 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
3754 DeclContext *Start) -> DeclContextList {
3755 assert(Start && "Building a context chain from a null context");
3756 DeclContextList Chain;
3757 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
3758 DC = DC->getLookupParent()) {
3759 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
3760 if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
3761 !(ND && ND->isAnonymousNamespace()))
3762 Chain.push_back(DC->getPrimaryContext());
3767 void TypoCorrectionConsumer::NamespaceSpecifierSet::sortNamespaces() {
3768 SmallVector<unsigned, 4> sortedDistances;
3769 sortedDistances.append(Distances.begin(), Distances.end());
3771 if (sortedDistances.size() > 1)
3772 std::sort(sortedDistances.begin(), sortedDistances.end());
3775 for (auto D : sortedDistances) {
3776 SpecifierInfoList &SpecList = DistanceMap[D];
3777 Specifiers.append(SpecList.begin(), SpecList.end());
3784 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
3785 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) {
3786 unsigned NumSpecifiers = 0;
3787 for (DeclContextList::reverse_iterator C = DeclChain.rbegin(),
3788 CEnd = DeclChain.rend();
3790 if (NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(*C)) {
3791 NNS = NestedNameSpecifier::Create(Context, NNS, ND);
3793 } else if (RecordDecl *RD = dyn_cast_or_null<RecordDecl>(*C)) {
3794 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(),
3795 RD->getTypeForDecl());
3799 return NumSpecifiers;
3802 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
3804 NestedNameSpecifier *NNS = nullptr;
3805 unsigned NumSpecifiers = 0;
3806 DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
3807 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
3809 // Eliminate common elements from the two DeclContext chains.
3810 for (DeclContextList::reverse_iterator C = CurContextChain.rbegin(),
3811 CEnd = CurContextChain.rend();
3812 C != CEnd && !NamespaceDeclChain.empty() &&
3813 NamespaceDeclChain.back() == *C; ++C) {
3814 NamespaceDeclChain.pop_back();
3817 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
3818 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
3820 // Add an explicit leading '::' specifier if needed.
3821 if (NamespaceDeclChain.empty()) {
3822 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
3823 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
3825 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
3826 } else if (NamedDecl *ND =
3827 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
3828 IdentifierInfo *Name = ND->getIdentifier();
3829 bool SameNameSpecifier = false;
3830 if (std::find(CurNameSpecifierIdentifiers.begin(),
3831 CurNameSpecifierIdentifiers.end(),
3832 Name) != CurNameSpecifierIdentifiers.end()) {
3833 std::string NewNameSpecifier;
3834 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
3835 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
3836 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
3837 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
3838 SpecifierOStream.flush();
3839 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
3841 if (SameNameSpecifier ||
3842 std::find(CurContextIdentifiers.begin(), CurContextIdentifiers.end(),
3843 Name) != CurContextIdentifiers.end()) {
3844 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
3845 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
3847 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
3851 // If the built NestedNameSpecifier would be replacing an existing
3852 // NestedNameSpecifier, use the number of component identifiers that
3853 // would need to be changed as the edit distance instead of the number
3854 // of components in the built NestedNameSpecifier.
3855 if (NNS && !CurNameSpecifierIdentifiers.empty()) {
3856 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
3857 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
3858 NumSpecifiers = llvm::ComputeEditDistance(
3859 ArrayRef<const IdentifierInfo *>(CurNameSpecifierIdentifiers),
3860 ArrayRef<const IdentifierInfo *>(NewNameSpecifierIdentifiers));
3864 Distances.insert(NumSpecifiers);
3865 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
3866 DistanceMap[NumSpecifiers].push_back(SI);
3869 /// \brief Perform name lookup for a possible result for typo correction.
3870 static void LookupPotentialTypoResult(Sema &SemaRef,
3872 IdentifierInfo *Name,
3873 Scope *S, CXXScopeSpec *SS,
3874 DeclContext *MemberContext,
3875 bool EnteringContext,
3876 bool isObjCIvarLookup,
3878 Res.suppressDiagnostics();
3880 Res.setLookupName(Name);
3881 Res.setAllowHidden(FindHidden);
3882 if (MemberContext) {
3883 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
3884 if (isObjCIvarLookup) {
3885 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
3892 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(Name)) {
3899 SemaRef.LookupQualifiedName(Res, MemberContext);
3903 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
3906 // Fake ivar lookup; this should really be part of
3907 // LookupParsedName.
3908 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
3909 if (Method->isInstanceMethod() && Method->getClassInterface() &&
3911 (Res.isSingleResult() &&
3912 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) {
3913 if (ObjCIvarDecl *IV
3914 = Method->getClassInterface()->lookupInstanceVariable(Name)) {
3922 /// \brief Add keywords to the consumer as possible typo corrections.
3923 static void AddKeywordsToConsumer(Sema &SemaRef,
3924 TypoCorrectionConsumer &Consumer,
3925 Scope *S, CorrectionCandidateCallback &CCC,
3926 bool AfterNestedNameSpecifier) {
3927 if (AfterNestedNameSpecifier) {
3928 // For 'X::', we know exactly which keywords can appear next.
3929 Consumer.addKeywordResult("template");
3930 if (CCC.WantExpressionKeywords)
3931 Consumer.addKeywordResult("operator");
3935 if (CCC.WantObjCSuper)
3936 Consumer.addKeywordResult("super");
3938 if (CCC.WantTypeSpecifiers) {
3939 // Add type-specifier keywords to the set of results.
3940 static const char *const CTypeSpecs[] = {
3941 "char", "const", "double", "enum", "float", "int", "long", "short",
3942 "signed", "struct", "union", "unsigned", "void", "volatile",
3943 "_Complex", "_Imaginary",
3944 // storage-specifiers as well
3945 "extern", "inline", "static", "typedef"
3948 const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs);
3949 for (unsigned I = 0; I != NumCTypeSpecs; ++I)
3950 Consumer.addKeywordResult(CTypeSpecs[I]);
3952 if (SemaRef.getLangOpts().C99)
3953 Consumer.addKeywordResult("restrict");
3954 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
3955 Consumer.addKeywordResult("bool");
3956 else if (SemaRef.getLangOpts().C99)
3957 Consumer.addKeywordResult("_Bool");
3959 if (SemaRef.getLangOpts().CPlusPlus) {
3960 Consumer.addKeywordResult("class");
3961 Consumer.addKeywordResult("typename");
3962 Consumer.addKeywordResult("wchar_t");
3964 if (SemaRef.getLangOpts().CPlusPlus11) {
3965 Consumer.addKeywordResult("char16_t");
3966 Consumer.addKeywordResult("char32_t");
3967 Consumer.addKeywordResult("constexpr");
3968 Consumer.addKeywordResult("decltype");
3969 Consumer.addKeywordResult("thread_local");
3973 if (SemaRef.getLangOpts().GNUMode)
3974 Consumer.addKeywordResult("typeof");
3977 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
3978 Consumer.addKeywordResult("const_cast");
3979 Consumer.addKeywordResult("dynamic_cast");
3980 Consumer.addKeywordResult("reinterpret_cast");
3981 Consumer.addKeywordResult("static_cast");
3984 if (CCC.WantExpressionKeywords) {
3985 Consumer.addKeywordResult("sizeof");
3986 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
3987 Consumer.addKeywordResult("false");
3988 Consumer.addKeywordResult("true");
3991 if (SemaRef.getLangOpts().CPlusPlus) {
3992 static const char *const CXXExprs[] = {
3993 "delete", "new", "operator", "throw", "typeid"
3995 const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs);
3996 for (unsigned I = 0; I != NumCXXExprs; ++I)
3997 Consumer.addKeywordResult(CXXExprs[I]);
3999 if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
4000 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
4001 Consumer.addKeywordResult("this");
4003 if (SemaRef.getLangOpts().CPlusPlus11) {
4004 Consumer.addKeywordResult("alignof");
4005 Consumer.addKeywordResult("nullptr");
4009 if (SemaRef.getLangOpts().C11) {
4010 // FIXME: We should not suggest _Alignof if the alignof macro
4012 Consumer.addKeywordResult("_Alignof");
4016 if (CCC.WantRemainingKeywords) {
4017 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
4019 static const char *const CStmts[] = {
4020 "do", "else", "for", "goto", "if", "return", "switch", "while" };
4021 const unsigned NumCStmts = llvm::array_lengthof(CStmts);
4022 for (unsigned I = 0; I != NumCStmts; ++I)
4023 Consumer.addKeywordResult(CStmts[I]);
4025 if (SemaRef.getLangOpts().CPlusPlus) {
4026 Consumer.addKeywordResult("catch");
4027 Consumer.addKeywordResult("try");
4030 if (S && S->getBreakParent())
4031 Consumer.addKeywordResult("break");
4033 if (S && S->getContinueParent())
4034 Consumer.addKeywordResult("continue");
4036 if (!SemaRef.getCurFunction()->SwitchStack.empty()) {
4037 Consumer.addKeywordResult("case");
4038 Consumer.addKeywordResult("default");
4041 if (SemaRef.getLangOpts().CPlusPlus) {
4042 Consumer.addKeywordResult("namespace");
4043 Consumer.addKeywordResult("template");
4046 if (S && S->isClassScope()) {
4047 Consumer.addKeywordResult("explicit");
4048 Consumer.addKeywordResult("friend");
4049 Consumer.addKeywordResult("mutable");
4050 Consumer.addKeywordResult("private");
4051 Consumer.addKeywordResult("protected");
4052 Consumer.addKeywordResult("public");
4053 Consumer.addKeywordResult("virtual");
4057 if (SemaRef.getLangOpts().CPlusPlus) {
4058 Consumer.addKeywordResult("using");
4060 if (SemaRef.getLangOpts().CPlusPlus11)
4061 Consumer.addKeywordResult("static_assert");
4066 /// \brief Check whether the declarations found for a typo correction are
4067 /// visible, and if none of them are, convert the correction to an 'import
4068 /// a module' correction.
4069 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
4070 if (TC.begin() == TC.end())
4073 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
4075 for (/**/; DI != DE; ++DI)
4076 if (!LookupResult::isVisible(SemaRef, *DI))
4078 // Nothing to do if all decls are visible.
4082 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
4083 bool AnyVisibleDecls = !NewDecls.empty();
4085 for (/**/; DI != DE; ++DI) {
4086 NamedDecl *VisibleDecl = *DI;
4087 if (!LookupResult::isVisible(SemaRef, *DI))
4088 VisibleDecl = findAcceptableDecl(SemaRef, *DI);
4091 if (!AnyVisibleDecls) {
4092 // Found a visible decl, discard all hidden ones.
4093 AnyVisibleDecls = true;
4096 NewDecls.push_back(VisibleDecl);
4097 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
4098 NewDecls.push_back(*DI);
4101 if (NewDecls.empty())
4102 TC = TypoCorrection();
4104 TC.setCorrectionDecls(NewDecls);
4105 TC.setRequiresImport(!AnyVisibleDecls);
4109 /// \brief Try to "correct" a typo in the source code by finding
4110 /// visible declarations whose names are similar to the name that was
4111 /// present in the source code.
4113 /// \param TypoName the \c DeclarationNameInfo structure that contains
4114 /// the name that was present in the source code along with its location.
4116 /// \param LookupKind the name-lookup criteria used to search for the name.
4118 /// \param S the scope in which name lookup occurs.
4120 /// \param SS the nested-name-specifier that precedes the name we're
4121 /// looking for, if present.
4123 /// \param CCC A CorrectionCandidateCallback object that provides further
4124 /// validation of typo correction candidates. It also provides flags for
4125 /// determining the set of keywords permitted.
4127 /// \param MemberContext if non-NULL, the context in which to look for
4128 /// a member access expression.
4130 /// \param EnteringContext whether we're entering the context described by
4131 /// the nested-name-specifier SS.
4133 /// \param OPT when non-NULL, the search for visible declarations will
4134 /// also walk the protocols in the qualified interfaces of \p OPT.
4136 /// \returns a \c TypoCorrection containing the corrected name if the typo
4137 /// along with information such as the \c NamedDecl where the corrected name
4138 /// was declared, and any additional \c NestedNameSpecifier needed to access
4139 /// it (C++ only). The \c TypoCorrection is empty if there is no correction.
4140 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
4141 Sema::LookupNameKind LookupKind,
4142 Scope *S, CXXScopeSpec *SS,
4143 CorrectionCandidateCallback &CCC,
4144 CorrectTypoKind Mode,
4145 DeclContext *MemberContext,
4146 bool EnteringContext,
4147 const ObjCObjectPointerType *OPT,
4148 bool RecordFailure) {
4149 // Always let the ExternalSource have the first chance at correction, even
4150 // if we would otherwise have given up.
4151 if (ExternalSource) {
4152 if (TypoCorrection Correction = ExternalSource->CorrectTypo(
4153 TypoName, LookupKind, S, SS, CCC, MemberContext, EnteringContext, OPT))
4157 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
4158 DisableTypoCorrection)
4159 return TypoCorrection();
4161 // In Microsoft mode, don't perform typo correction in a template member
4162 // function dependent context because it interferes with the "lookup into
4163 // dependent bases of class templates" feature.
4164 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
4165 isa<CXXMethodDecl>(CurContext))
4166 return TypoCorrection();
4168 // We only attempt to correct typos for identifiers.
4169 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4171 return TypoCorrection();
4173 // If the scope specifier itself was invalid, don't try to correct
4175 if (SS && SS->isInvalid())
4176 return TypoCorrection();
4178 // Never try to correct typos during template deduction or
4180 if (!ActiveTemplateInstantiations.empty())
4181 return TypoCorrection();
4183 // Don't try to correct 'super'.
4184 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
4185 return TypoCorrection();
4187 // Abort if typo correction already failed for this specific typo.
4188 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
4189 if (locs != TypoCorrectionFailures.end() &&
4190 locs->second.count(TypoName.getLoc()))
4191 return TypoCorrection();
4193 // Don't try to correct the identifier "vector" when in AltiVec mode.
4194 // TODO: Figure out why typo correction misbehaves in this case, fix it, and
4195 // remove this workaround.
4196 if (getLangOpts().AltiVec && Typo->isStr("vector"))
4197 return TypoCorrection();
4199 // If we're handling a missing symbol error, using modules, and the
4200 // special search all modules option is used, look for a missing import.
4201 if ((Mode == CTK_ErrorRecovery) && getLangOpts().Modules &&
4202 getLangOpts().ModulesSearchAll) {
4203 // The following has the side effect of loading the missing module.
4204 getModuleLoader().lookupMissingImports(Typo->getName(),
4205 TypoName.getLocStart());
4208 TypoCorrectionConsumer Consumer(*this, TypoName, LookupKind, S, SS, CCC,
4209 MemberContext, EnteringContext);
4211 // If a callback object considers an empty typo correction candidate to be
4212 // viable, assume it does not do any actual validation of the candidates.
4213 TypoCorrection EmptyCorrection;
4214 bool ValidatingCallback = !isCandidateViable(CCC, EmptyCorrection);
4216 // Perform name lookup to find visible, similarly-named entities.
4217 bool IsUnqualifiedLookup = false;
4218 DeclContext *QualifiedDC = MemberContext;
4219 if (MemberContext) {
4220 LookupVisibleDecls(MemberContext, LookupKind, Consumer);
4222 // Look in qualified interfaces.
4224 for (auto *I : OPT->quals())
4225 LookupVisibleDecls(I, LookupKind, Consumer);
4227 } else if (SS && SS->isSet()) {
4228 QualifiedDC = computeDeclContext(*SS, EnteringContext);
4230 return TypoCorrection();
4232 // Provide a stop gap for files that are just seriously broken. Trying
4233 // to correct all typos can turn into a HUGE performance penalty, causing
4234 // some files to take minutes to get rejected by the parser.
4235 if (TyposCorrected + UnqualifiedTyposCorrected.size() >= 20)
4236 return TypoCorrection();
4239 LookupVisibleDecls(QualifiedDC, LookupKind, Consumer);
4241 IsUnqualifiedLookup = true;
4242 UnqualifiedTyposCorrectedMap::iterator Cached
4243 = UnqualifiedTyposCorrected.find(Typo);
4244 if (Cached != UnqualifiedTyposCorrected.end()) {
4245 // Add the cached value, unless it's a keyword or fails validation. In the
4246 // keyword case, we'll end up adding the keyword below.
4247 if (Cached->second) {
4248 if (!Cached->second.isKeyword() &&
4249 isCandidateViable(CCC, Cached->second)) {
4250 // Do not use correction that is unaccessible in the given scope.
4251 NamedDecl *CorrectionDecl = Cached->second.getCorrectionDecl();
4252 DeclarationNameInfo NameInfo(CorrectionDecl->getDeclName(),
4253 CorrectionDecl->getLocation());
4254 LookupResult R(*this, NameInfo, LookupOrdinaryName);
4255 if (LookupName(R, S))
4256 Consumer.addCorrection(Cached->second);
4259 // Only honor no-correction cache hits when a callback that will validate
4260 // correction candidates is not being used.
4261 if (!ValidatingCallback)
4262 return TypoCorrection();
4265 if (Cached == UnqualifiedTyposCorrected.end()) {
4266 // Provide a stop gap for files that are just seriously broken. Trying
4267 // to correct all typos can turn into a HUGE performance penalty, causing
4268 // some files to take minutes to get rejected by the parser.
4269 if (TyposCorrected + UnqualifiedTyposCorrected.size() >= 20)
4270 return TypoCorrection();
4274 // Determine whether we are going to search in the various namespaces for
4276 bool SearchNamespaces
4277 = getLangOpts().CPlusPlus &&
4278 (IsUnqualifiedLookup || (SS && SS->isSet()));
4279 // In a few cases we *only* want to search for corrections based on just
4280 // adding or changing the nested name specifier.
4281 unsigned TypoLen = Typo->getName().size();
4282 bool AllowOnlyNNSChanges = TypoLen < 3;
4284 if (IsUnqualifiedLookup || SearchNamespaces) {
4285 // For unqualified lookup, look through all of the names that we have
4286 // seen in this translation unit.
4287 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4288 for (const auto &I : Context.Idents)
4289 Consumer.FoundName(I.getKey());
4291 // Walk through identifiers in external identifier sources.
4292 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4293 if (IdentifierInfoLookup *External
4294 = Context.Idents.getExternalIdentifierLookup()) {
4295 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4297 StringRef Name = Iter->Next();
4301 Consumer.FoundName(Name);
4306 AddKeywordsToConsumer(*this, Consumer, S, CCC, SS && SS->isNotEmpty());
4308 // If we haven't found anything, we're done.
4309 if (Consumer.empty())
4310 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure,
4311 IsUnqualifiedLookup);
4313 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4314 // is not more that about a third of the length of the typo's identifier.
4315 unsigned ED = Consumer.getBestEditDistance(true);
4316 if (ED > 0 && TypoLen / ED < 3)
4317 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure,
4318 IsUnqualifiedLookup);
4320 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
4321 // to search those namespaces.
4322 if (SearchNamespaces) {
4323 // Load any externally-known namespaces.
4324 if (ExternalSource && !LoadedExternalKnownNamespaces) {
4325 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
4326 LoadedExternalKnownNamespaces = true;
4327 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
4328 for (auto *N : ExternalKnownNamespaces)
4329 KnownNamespaces[N] = true;
4332 Consumer.addNamespaces(KnownNamespaces);
4335 TypoCorrection BestTC = Consumer.getNextCorrection();
4336 TypoCorrection SecondBestTC = Consumer.getNextCorrection();
4338 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4340 ED = BestTC.getEditDistance();
4342 if (!AllowOnlyNNSChanges && ED > 0 && TypoLen / ED < 3) {
4343 // If this was an unqualified lookup and we believe the callback
4344 // object wouldn't have filtered out possible corrections, note
4345 // that no correction was found.
4346 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure,
4347 IsUnqualifiedLookup && !ValidatingCallback);
4350 // If only a single name remains, return that result.
4351 if (!SecondBestTC ||
4352 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
4353 const TypoCorrection &Result = BestTC;
4355 // Don't correct to a keyword that's the same as the typo; the keyword
4356 // wasn't actually in scope.
4357 if (ED == 0 && Result.isKeyword())
4358 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4360 // Record the correction for unqualified lookup.
4361 if (IsUnqualifiedLookup)
4362 UnqualifiedTyposCorrected[Typo] = Result;
4364 TypoCorrection TC = Result;
4365 TC.setCorrectionRange(SS, TypoName);
4366 checkCorrectionVisibility(*this, TC);
4369 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
4370 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
4371 // some instances of CTC_Unknown, while WantRemainingKeywords is true
4372 // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
4373 else if (SecondBestTC && CCC.WantObjCSuper && !CCC.WantRemainingKeywords) {
4374 // Prefer 'super' when we're completing in a message-receiver
4377 if (BestTC.getCorrection().getAsString() != "super") {
4378 if (SecondBestTC.getCorrection().getAsString() == "super")
4379 BestTC = SecondBestTC;
4380 else if (Consumer["super"].front().isKeyword())
4381 BestTC = Consumer["super"].front();
4383 // Don't correct to a keyword that's the same as the typo; the keyword
4384 // wasn't actually in scope.
4385 if (BestTC.getEditDistance() == 0 ||
4386 BestTC.getCorrection().getAsString() != "super")
4387 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4389 // Record the correction for unqualified lookup.
4390 if (IsUnqualifiedLookup)
4391 UnqualifiedTyposCorrected[Typo] = BestTC;
4393 BestTC.setCorrectionRange(SS, TypoName);
4397 // Record the failure's location if needed and return an empty correction. If
4398 // this was an unqualified lookup and we believe the callback object did not
4399 // filter out possible corrections, also cache the failure for the typo.
4400 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure,
4401 IsUnqualifiedLookup && !ValidatingCallback);
4404 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) {
4408 CorrectionDecls.clear();
4410 CorrectionDecls.push_back(CDecl->getUnderlyingDecl());
4412 if (!CorrectionName)
4413 CorrectionName = CDecl->getDeclName();
4416 std::string TypoCorrection::getAsString(const LangOptions &LO) const {
4417 if (CorrectionNameSpec) {
4418 std::string tmpBuffer;
4419 llvm::raw_string_ostream PrefixOStream(tmpBuffer);
4420 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO));
4421 PrefixOStream << CorrectionName;
4422 return PrefixOStream.str();
4425 return CorrectionName.getAsString();
4428 bool CorrectionCandidateCallback::ValidateCandidate(const TypoCorrection &candidate) {
4429 if (!candidate.isResolved())
4432 if (candidate.isKeyword())
4433 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
4434 WantRemainingKeywords || WantObjCSuper;
4436 bool HasNonType = false;
4437 bool HasStaticMethod = false;
4438 bool HasNonStaticMethod = false;
4439 for (Decl *D : candidate) {
4440 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
4441 D = FTD->getTemplatedDecl();
4442 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
4443 if (Method->isStatic())
4444 HasStaticMethod = true;
4446 HasNonStaticMethod = true;
4448 if (!isa<TypeDecl>(D))
4452 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
4453 !candidate.getCorrectionSpecifier())
4456 return WantTypeSpecifiers || HasNonType;
4459 FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs,
4460 bool HasExplicitTemplateArgs,
4462 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
4463 CurContext(SemaRef.CurContext), MemberFn(ME) {
4464 WantTypeSpecifiers = SemaRef.getLangOpts().CPlusPlus;
4465 WantRemainingKeywords = false;
4468 bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) {
4469 if (!candidate.getCorrectionDecl())
4470 return candidate.isKeyword();
4472 for (auto *C : candidate) {
4473 FunctionDecl *FD = nullptr;
4474 NamedDecl *ND = C->getUnderlyingDecl();
4475 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
4476 FD = FTD->getTemplatedDecl();
4477 if (!HasExplicitTemplateArgs && !FD) {
4478 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
4479 // If the Decl is neither a function nor a template function,
4480 // determine if it is a pointer or reference to a function. If so,
4481 // check against the number of arguments expected for the pointee.
4482 QualType ValType = cast<ValueDecl>(ND)->getType();
4483 if (ValType->isAnyPointerType() || ValType->isReferenceType())
4484 ValType = ValType->getPointeeType();
4485 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
4486 if (FPT->getNumParams() == NumArgs)
4491 // Skip the current candidate if it is not a FunctionDecl or does not accept
4492 // the current number of arguments.
4493 if (!FD || !(FD->getNumParams() >= NumArgs &&
4494 FD->getMinRequiredArguments() <= NumArgs))
4497 // If the current candidate is a non-static C++ method, skip the candidate
4498 // unless the method being corrected--or the current DeclContext, if the
4499 // function being corrected is not a method--is a method in the same class
4500 // or a descendent class of the candidate's parent class.
4501 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
4502 if (MemberFn || !MD->isStatic()) {
4503 CXXMethodDecl *CurMD =
4505 ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl())
4506 : dyn_cast_or_null<CXXMethodDecl>(CurContext);
4507 CXXRecordDecl *CurRD =
4508 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
4509 CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
4510 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
4519 void Sema::diagnoseTypo(const TypoCorrection &Correction,
4520 const PartialDiagnostic &TypoDiag,
4521 bool ErrorRecovery) {
4522 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
4526 /// Find which declaration we should import to provide the definition of
4527 /// the given declaration.
4528 static const NamedDecl *getDefinitionToImport(const NamedDecl *D) {
4529 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
4530 return VD->getDefinition();
4531 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
4532 return FD->isDefined(FD) ? FD : nullptr;
4533 if (const TagDecl *TD = dyn_cast<TagDecl>(D))
4534 return TD->getDefinition();
4535 if (const ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
4536 return ID->getDefinition();
4537 if (const ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
4538 return PD->getDefinition();
4539 if (const TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
4540 return getDefinitionToImport(TD->getTemplatedDecl());
4544 /// \brief Diagnose a successfully-corrected typo. Separated from the correction
4545 /// itself to allow external validation of the result, etc.
4547 /// \param Correction The result of performing typo correction.
4548 /// \param TypoDiag The diagnostic to produce. This will have the corrected
4549 /// string added to it (and usually also a fixit).
4550 /// \param PrevNote A note to use when indicating the location of the entity to
4551 /// which we are correcting. Will have the correction string added to it.
4552 /// \param ErrorRecovery If \c true (the default), the caller is going to
4553 /// recover from the typo as if the corrected string had been typed.
4554 /// In this case, \c PDiag must be an error, and we will attach a fixit
4556 void Sema::diagnoseTypo(const TypoCorrection &Correction,
4557 const PartialDiagnostic &TypoDiag,
4558 const PartialDiagnostic &PrevNote,
4559 bool ErrorRecovery) {
4560 std::string CorrectedStr = Correction.getAsString(getLangOpts());
4561 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
4562 FixItHint FixTypo = FixItHint::CreateReplacement(
4563 Correction.getCorrectionRange(), CorrectedStr);
4565 // Maybe we're just missing a module import.
4566 if (Correction.requiresImport()) {
4567 NamedDecl *Decl = Correction.getCorrectionDecl();
4568 assert(Decl && "import required but no declaration to import");
4570 // Suggest importing a module providing the definition of this entity, if
4572 const NamedDecl *Def = getDefinitionToImport(Decl);
4575 Module *Owner = Def->getOwningModule();
4576 assert(Owner && "definition of hidden declaration is not in a module");
4578 Diag(Correction.getCorrectionRange().getBegin(),
4579 diag::err_module_private_declaration)
4580 << Def << Owner->getFullModuleName();
4581 Diag(Def->getLocation(), diag::note_previous_declaration);
4583 // Recover by implicitly importing this module.
4585 createImplicitModuleImportForErrorRecovery(
4586 Correction.getCorrectionRange().getBegin(), Owner);
4590 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
4591 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
4593 NamedDecl *ChosenDecl =
4594 Correction.isKeyword() ? nullptr : Correction.getCorrectionDecl();
4595 if (PrevNote.getDiagID() && ChosenDecl)
4596 Diag(ChosenDecl->getLocation(), PrevNote)
4597 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);