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 //===----------------------------------------------------------------------===//
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/CXXInheritance.h"
18 #include "clang/AST/Decl.h"
19 #include "clang/AST/DeclCXX.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/Parse/DeclSpec.h"
25 #include "clang/Basic/Builtins.h"
26 #include "clang/Basic/LangOptions.h"
27 #include "llvm/ADT/STLExtras.h"
28 #include "llvm/ADT/SmallPtrSet.h"
29 #include "llvm/Support/ErrorHandling.h"
37 using namespace clang;
40 class UnqualUsingEntry {
41 const DeclContext *Nominated;
42 const DeclContext *CommonAncestor;
45 UnqualUsingEntry(const DeclContext *Nominated,
46 const DeclContext *CommonAncestor)
47 : Nominated(Nominated), CommonAncestor(CommonAncestor) {
50 const DeclContext *getCommonAncestor() const {
51 return CommonAncestor;
54 const DeclContext *getNominatedNamespace() const {
58 // Sort by the pointer value of the common ancestor.
60 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) {
61 return L.getCommonAncestor() < R.getCommonAncestor();
64 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) {
65 return E.getCommonAncestor() < DC;
68 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) {
69 return DC < E.getCommonAncestor();
74 /// A collection of using directives, as used by C++ unqualified
76 class UnqualUsingDirectiveSet {
77 typedef llvm::SmallVector<UnqualUsingEntry, 8> ListTy;
80 llvm::SmallPtrSet<DeclContext*, 8> visited;
83 UnqualUsingDirectiveSet() {}
85 void visitScopeChain(Scope *S, Scope *InnermostFileScope) {
86 // C++ [namespace.udir]p1:
87 // During unqualified name lookup, the names appear as if they
88 // were declared in the nearest enclosing namespace which contains
89 // both the using-directive and the nominated namespace.
90 DeclContext *InnermostFileDC
91 = static_cast<DeclContext*>(InnermostFileScope->getEntity());
92 assert(InnermostFileDC && InnermostFileDC->isFileContext());
94 for (; S; S = S->getParent()) {
95 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) {
96 DeclContext *EffectiveDC = (Ctx->isFileContext() ? Ctx : InnermostFileDC);
97 visit(Ctx, EffectiveDC);
99 Scope::udir_iterator I = S->using_directives_begin(),
100 End = S->using_directives_end();
102 for (; I != End; ++I)
103 visit(I->getAs<UsingDirectiveDecl>(), InnermostFileDC);
108 // Visits a context and collect all of its using directives
109 // recursively. Treats all using directives as if they were
110 // declared in the context.
112 // A given context is only every visited once, so it is important
113 // that contexts be visited from the inside out in order to get
114 // the effective DCs right.
115 void visit(DeclContext *DC, DeclContext *EffectiveDC) {
116 if (!visited.insert(DC))
119 addUsingDirectives(DC, EffectiveDC);
122 // Visits a using directive and collects all of its using
123 // directives recursively. Treats all using directives as if they
124 // were declared in the effective DC.
125 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
126 DeclContext *NS = UD->getNominatedNamespace();
127 if (!visited.insert(NS))
130 addUsingDirective(UD, EffectiveDC);
131 addUsingDirectives(NS, EffectiveDC);
134 // Adds all the using directives in a context (and those nominated
135 // by its using directives, transitively) as if they appeared in
136 // the given effective context.
137 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) {
138 llvm::SmallVector<DeclContext*,4> queue;
140 DeclContext::udir_iterator I, End;
141 for (llvm::tie(I, End) = DC->getUsingDirectives(); I != End; ++I) {
142 UsingDirectiveDecl *UD = *I;
143 DeclContext *NS = UD->getNominatedNamespace();
144 if (visited.insert(NS)) {
145 addUsingDirective(UD, EffectiveDC);
158 // Add a using directive as if it had been declared in the given
159 // context. This helps implement C++ [namespace.udir]p3:
160 // The using-directive is transitive: if a scope contains a
161 // using-directive that nominates a second namespace that itself
162 // contains using-directives, the effect is as if the
163 // using-directives from the second namespace also appeared in
165 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
166 // Find the common ancestor between the effective context and
167 // the nominated namespace.
168 DeclContext *Common = UD->getNominatedNamespace();
169 while (!Common->Encloses(EffectiveDC))
170 Common = Common->getParent();
171 Common = Common->getPrimaryContext();
173 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common));
177 std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator());
180 typedef ListTy::iterator iterator;
181 typedef ListTy::const_iterator const_iterator;
183 iterator begin() { return list.begin(); }
184 iterator end() { return list.end(); }
185 const_iterator begin() const { return list.begin(); }
186 const_iterator end() const { return list.end(); }
188 std::pair<const_iterator,const_iterator>
189 getNamespacesFor(DeclContext *DC) const {
190 return std::equal_range(begin(), end(), DC->getPrimaryContext(),
191 UnqualUsingEntry::Comparator());
196 static bool IsAcceptableIDNS(NamedDecl *D, unsigned IDNS) {
197 return D->isInIdentifierNamespace(IDNS);
200 static bool IsAcceptableOperatorName(NamedDecl *D, unsigned IDNS) {
201 return D->isInIdentifierNamespace(IDNS) &&
202 !D->getDeclContext()->isRecord();
205 static bool IsAcceptableNestedNameSpecifierName(NamedDecl *D, unsigned IDNS) {
206 // This lookup ignores everything that isn't a type.
208 // This is a fast check for the far most common case.
209 if (D->isInIdentifierNamespace(Decl::IDNS_Tag))
212 if (isa<UsingShadowDecl>(D))
213 D = cast<UsingShadowDecl>(D)->getTargetDecl();
215 return isa<TypeDecl>(D);
218 static bool IsAcceptableNamespaceName(NamedDecl *D, unsigned IDNS) {
219 // We don't need to look through using decls here because
220 // using decls aren't allowed to name namespaces.
222 return isa<NamespaceDecl>(D) || isa<NamespaceAliasDecl>(D);
225 /// Gets the default result filter for the given lookup.
227 LookupResult::ResultFilter getResultFilter(Sema::LookupNameKind NameKind) {
229 case Sema::LookupOrdinaryName:
230 case Sema::LookupTagName:
231 case Sema::LookupMemberName:
232 case Sema::LookupRedeclarationWithLinkage: // FIXME: check linkage, scoping
233 case Sema::LookupUsingDeclName:
234 case Sema::LookupObjCProtocolName:
235 case Sema::LookupObjCImplementationName:
236 return &IsAcceptableIDNS;
238 case Sema::LookupOperatorName:
239 return &IsAcceptableOperatorName;
241 case Sema::LookupNestedNameSpecifierName:
242 return &IsAcceptableNestedNameSpecifierName;
244 case Sema::LookupNamespaceName:
245 return &IsAcceptableNamespaceName;
248 llvm_unreachable("unkknown lookup kind");
252 // Retrieve the set of identifier namespaces that correspond to a
253 // specific kind of name lookup.
254 static inline unsigned getIDNS(Sema::LookupNameKind NameKind,
256 bool Redeclaration) {
259 case Sema::LookupOrdinaryName:
260 case Sema::LookupOperatorName:
261 case Sema::LookupRedeclarationWithLinkage:
262 IDNS = Decl::IDNS_Ordinary;
264 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member;
265 if (Redeclaration) IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend;
269 case Sema::LookupTagName:
270 IDNS = Decl::IDNS_Tag;
271 if (CPlusPlus && Redeclaration)
272 IDNS |= Decl::IDNS_TagFriend;
275 case Sema::LookupMemberName:
276 IDNS = Decl::IDNS_Member;
278 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary;
281 case Sema::LookupNestedNameSpecifierName:
282 case Sema::LookupNamespaceName:
283 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member;
286 case Sema::LookupUsingDeclName:
287 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag
288 | Decl::IDNS_Member | Decl::IDNS_Using;
291 case Sema::LookupObjCProtocolName:
292 IDNS = Decl::IDNS_ObjCProtocol;
295 case Sema::LookupObjCImplementationName:
296 IDNS = Decl::IDNS_ObjCImplementation;
302 void LookupResult::configure() {
303 IDNS = getIDNS(LookupKind,
304 SemaRef.getLangOptions().CPlusPlus,
305 isForRedeclaration());
306 IsAcceptableFn = getResultFilter(LookupKind);
309 // Necessary because CXXBasePaths is not complete in Sema.h
310 void LookupResult::deletePaths(CXXBasePaths *Paths) {
314 /// Resolves the result kind of this lookup.
315 void LookupResult::resolveKind() {
316 unsigned N = Decls.size();
318 // Fast case: no possible ambiguity.
320 assert(ResultKind == NotFound || ResultKind == NotFoundInCurrentInstantiation);
324 // If there's a single decl, we need to examine it to decide what
325 // kind of lookup this is.
327 if (isa<FunctionTemplateDecl>(*Decls.begin()))
328 ResultKind = FoundOverloaded;
329 else if (isa<UnresolvedUsingValueDecl>(*Decls.begin()))
330 ResultKind = FoundUnresolvedValue;
334 // Don't do any extra resolution if we've already resolved as ambiguous.
335 if (ResultKind == Ambiguous) return;
337 llvm::SmallPtrSet<NamedDecl*, 16> Unique;
339 bool Ambiguous = false;
340 bool HasTag = false, HasFunction = false, HasNonFunction = false;
341 bool HasFunctionTemplate = false, HasUnresolved = false;
343 unsigned UniqueTagIndex = 0;
347 NamedDecl *D = Decls[I]->getUnderlyingDecl();
348 D = cast<NamedDecl>(D->getCanonicalDecl());
350 if (!Unique.insert(D)) {
351 // If it's not unique, pull something off the back (and
352 // continue at this index).
353 Decls[I] = Decls[--N];
355 // Otherwise, do some decl type analysis and then continue.
357 if (isa<UnresolvedUsingValueDecl>(D)) {
358 HasUnresolved = true;
359 } else if (isa<TagDecl>(D)) {
364 } else if (isa<FunctionTemplateDecl>(D)) {
366 HasFunctionTemplate = true;
367 } else if (isa<FunctionDecl>(D)) {
372 HasNonFunction = true;
378 // C++ [basic.scope.hiding]p2:
379 // A class name or enumeration name can be hidden by the name of
380 // an object, function, or enumerator declared in the same
381 // scope. If a class or enumeration name and an object, function,
382 // or enumerator are declared in the same scope (in any order)
383 // with the same name, the class or enumeration name is hidden
384 // wherever the object, function, or enumerator name is visible.
385 // But it's still an error if there are distinct tag types found,
386 // even if they're not visible. (ref?)
387 if (HideTags && HasTag && !Ambiguous &&
388 (HasFunction || HasNonFunction || HasUnresolved))
389 Decls[UniqueTagIndex] = Decls[--N];
393 if (HasNonFunction && (HasFunction || HasUnresolved))
397 setAmbiguous(LookupResult::AmbiguousReference);
398 else if (HasUnresolved)
399 ResultKind = LookupResult::FoundUnresolvedValue;
400 else if (N > 1 || HasFunctionTemplate)
401 ResultKind = LookupResult::FoundOverloaded;
403 ResultKind = LookupResult::Found;
406 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
407 CXXBasePaths::const_paths_iterator I, E;
408 DeclContext::lookup_iterator DI, DE;
409 for (I = P.begin(), E = P.end(); I != E; ++I)
410 for (llvm::tie(DI,DE) = I->Decls; DI != DE; ++DI)
414 void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) {
415 Paths = new CXXBasePaths;
417 addDeclsFromBasePaths(*Paths);
419 setAmbiguous(AmbiguousBaseSubobjects);
422 void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) {
423 Paths = new CXXBasePaths;
425 addDeclsFromBasePaths(*Paths);
427 setAmbiguous(AmbiguousBaseSubobjectTypes);
430 void LookupResult::print(llvm::raw_ostream &Out) {
431 Out << Decls.size() << " result(s)";
432 if (isAmbiguous()) Out << ", ambiguous";
433 if (Paths) Out << ", base paths present";
435 for (iterator I = begin(), E = end(); I != E; ++I) {
441 /// \brief Lookup a builtin function, when name lookup would otherwise
443 static bool LookupBuiltin(Sema &S, LookupResult &R) {
444 Sema::LookupNameKind NameKind = R.getLookupKind();
446 // If we didn't find a use of this identifier, and if the identifier
447 // corresponds to a compiler builtin, create the decl object for the builtin
448 // now, injecting it into translation unit scope, and return it.
449 if (NameKind == Sema::LookupOrdinaryName ||
450 NameKind == Sema::LookupRedeclarationWithLinkage) {
451 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo();
453 // If this is a builtin on this (or all) targets, create the decl.
454 if (unsigned BuiltinID = II->getBuiltinID()) {
455 // In C++, we don't have any predefined library functions like
456 // 'malloc'. Instead, we'll just error.
457 if (S.getLangOptions().CPlusPlus &&
458 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
461 NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID,
462 S.TUScope, R.isForRedeclaration(),
474 // Adds all qualifying matches for a name within a decl context to the
475 // given lookup result. Returns true if any matches were found.
476 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
479 DeclContext::lookup_const_iterator I, E;
480 for (llvm::tie(I, E) = DC->lookup(R.getLookupName()); I != E; ++I) {
482 if (R.isAcceptableDecl(D)) {
488 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R))
491 if (R.getLookupName().getNameKind()
492 != DeclarationName::CXXConversionFunctionName ||
493 R.getLookupName().getCXXNameType()->isDependentType() ||
494 !isa<CXXRecordDecl>(DC))
498 // A specialization of a conversion function template is not found by
499 // name lookup. Instead, any conversion function templates visible in the
500 // context of the use are considered. [...]
501 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
502 if (!Record->isDefinition())
505 const UnresolvedSetImpl *Unresolved = Record->getConversionFunctions();
506 for (UnresolvedSetImpl::iterator U = Unresolved->begin(),
507 UEnd = Unresolved->end(); U != UEnd; ++U) {
508 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
512 // When we're performing lookup for the purposes of redeclaration, just
513 // add the conversion function template. When we deduce template
514 // arguments for specializations, we'll end up unifying the return
515 // type of the new declaration with the type of the function template.
516 if (R.isForRedeclaration()) {
517 R.addDecl(ConvTemplate);
523 // [...] For each such operator, if argument deduction succeeds
524 // (14.9.2.3), the resulting specialization is used as if found by
527 // When referencing a conversion function for any purpose other than
528 // a redeclaration (such that we'll be building an expression with the
529 // result), perform template argument deduction and place the
530 // specialization into the result set. We do this to avoid forcing all
531 // callers to perform special deduction for conversion functions.
532 Sema::TemplateDeductionInfo Info(R.getSema().Context, R.getNameLoc());
533 FunctionDecl *Specialization = 0;
535 const FunctionProtoType *ConvProto
536 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
537 assert(ConvProto && "Nonsensical conversion function template type");
539 // Compute the type of the function that we would expect the conversion
540 // function to have, if it were to match the name given.
541 // FIXME: Calling convention!
542 QualType ExpectedType
543 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(),
544 0, 0, ConvProto->isVariadic(),
545 ConvProto->getTypeQuals(),
547 ConvProto->getNoReturnAttr(),
550 // Perform template argument deduction against the type that we would
551 // expect the function to have.
552 if (R.getSema().DeduceTemplateArguments(ConvTemplate, 0, ExpectedType,
553 Specialization, Info)
554 == Sema::TDK_Success) {
555 R.addDecl(Specialization);
563 // Performs C++ unqualified lookup into the given file context.
565 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context,
566 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
568 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
570 // Perform direct name lookup into the LookupCtx.
571 bool Found = LookupDirect(S, R, NS);
573 // Perform direct name lookup into the namespaces nominated by the
574 // using directives whose common ancestor is this namespace.
575 UnqualUsingDirectiveSet::const_iterator UI, UEnd;
576 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(NS);
578 for (; UI != UEnd; ++UI)
579 if (LookupDirect(S, R, UI->getNominatedNamespace()))
587 static bool isNamespaceOrTranslationUnitScope(Scope *S) {
588 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()))
589 return Ctx->isFileContext();
593 // Find the next outer declaration context corresponding to this scope.
594 static DeclContext *findOuterContext(Scope *S) {
595 for (S = S->getParent(); S; S = S->getParent())
597 return static_cast<DeclContext *>(S->getEntity())->getPrimaryContext();
602 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
603 assert(getLangOptions().CPlusPlus && "Can perform only C++ lookup");
605 DeclarationName Name = R.getLookupName();
608 IdentifierResolver::iterator
609 I = IdResolver.begin(Name),
610 IEnd = IdResolver.end();
612 // First we lookup local scope.
613 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
614 // ...During unqualified name lookup (3.4.1), the names appear as if
615 // they were declared in the nearest enclosing namespace which contains
616 // both the using-directive and the nominated namespace.
617 // [Note: in this context, "contains" means "contains directly or
621 // namespace A { int i; }
625 // using namespace A;
626 // ++i; // finds local 'i', A::i appears at global scope
630 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
631 // Check whether the IdResolver has anything in this scope.
633 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) {
634 if (R.isAcceptableDecl(*I)) {
644 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) {
645 DeclContext *OuterCtx = findOuterContext(S);
646 for (; Ctx && Ctx->getPrimaryContext() != OuterCtx;
647 Ctx = Ctx->getLookupParent()) {
648 // We do not directly look into transparent contexts, since
649 // those entities will be found in the nearest enclosing
650 // non-transparent context.
651 if (Ctx->isTransparentContext())
654 // We do not look directly into function or method contexts,
655 // since all of the local variables and parameters of the
656 // function/method are present within the Scope.
657 if (Ctx->isFunctionOrMethod()) {
658 // If we have an Objective-C instance method, look for ivars
659 // in the corresponding interface.
660 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
661 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
662 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
663 ObjCInterfaceDecl *ClassDeclared;
664 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
665 Name.getAsIdentifierInfo(),
667 if (R.isAcceptableDecl(Ivar)) {
679 // Perform qualified name lookup into this context.
680 // FIXME: In some cases, we know that every name that could be found by
681 // this qualified name lookup will also be on the identifier chain. For
682 // example, inside a class without any base classes, we never need to
683 // perform qualified lookup because all of the members are on top of the
685 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
691 // Stop if we ran out of scopes.
692 // FIXME: This really, really shouldn't be happening.
693 if (!S) return false;
695 // Collect UsingDirectiveDecls in all scopes, and recursively all
696 // nominated namespaces by those using-directives.
698 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
699 // don't build it for each lookup!
701 UnqualUsingDirectiveSet UDirs;
702 UDirs.visitScopeChain(Initial, S);
705 // Lookup namespace scope, and global scope.
706 // Unqualified name lookup in C++ requires looking into scopes
707 // that aren't strictly lexical, and therefore we walk through the
708 // context as well as walking through the scopes.
710 for (; S; S = S->getParent()) {
711 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity());
712 if (Ctx && Ctx->isTransparentContext())
715 // Check whether the IdResolver has anything in this scope.
717 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) {
718 if (R.isAcceptableDecl(*I)) {
719 // We found something. Look for anything else in our scope
720 // with this same name and in an acceptable identifier
721 // namespace, so that we can construct an overload set if we
729 assert(Ctx->isFileContext() &&
730 "We should have been looking only at file context here already.");
732 // Look into context considering using-directives.
733 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
742 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
749 /// @brief Perform unqualified name lookup starting from a given
752 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
753 /// used to find names within the current scope. For example, 'x' in
757 /// return x; // unqualified name look finds 'x' in the global scope
761 /// Different lookup criteria can find different names. For example, a
762 /// particular scope can have both a struct and a function of the same
763 /// name, and each can be found by certain lookup criteria. For more
764 /// information about lookup criteria, see the documentation for the
765 /// class LookupCriteria.
767 /// @param S The scope from which unqualified name lookup will
768 /// begin. If the lookup criteria permits, name lookup may also search
769 /// in the parent scopes.
771 /// @param Name The name of the entity that we are searching for.
773 /// @param Loc If provided, the source location where we're performing
774 /// name lookup. At present, this is only used to produce diagnostics when
775 /// C library functions (like "malloc") are implicitly declared.
777 /// @returns The result of name lookup, which includes zero or more
778 /// declarations and possibly additional information used to diagnose
780 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
781 DeclarationName Name = R.getLookupName();
782 if (!Name) return false;
784 LookupNameKind NameKind = R.getLookupKind();
786 if (!getLangOptions().CPlusPlus) {
787 // Unqualified name lookup in C/Objective-C is purely lexical, so
788 // search in the declarations attached to the name.
790 if (NameKind == Sema::LookupRedeclarationWithLinkage) {
791 // Find the nearest non-transparent declaration scope.
792 while (!(S->getFlags() & Scope::DeclScope) ||
794 static_cast<DeclContext *>(S->getEntity())
795 ->isTransparentContext()))
799 unsigned IDNS = R.getIdentifierNamespace();
801 // Scan up the scope chain looking for a decl that matches this
802 // identifier that is in the appropriate namespace. This search
803 // should not take long, as shadowing of names is uncommon, and
804 // deep shadowing is extremely uncommon.
805 bool LeftStartingScope = false;
807 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
808 IEnd = IdResolver.end();
810 if ((*I)->isInIdentifierNamespace(IDNS)) {
811 if (NameKind == LookupRedeclarationWithLinkage) {
812 // Determine whether this (or a previous) declaration is
814 if (!LeftStartingScope && !S->isDeclScope(DeclPtrTy::make(*I)))
815 LeftStartingScope = true;
817 // If we found something outside of our starting scope that
818 // does not have linkage, skip it.
819 if (LeftStartingScope && !((*I)->hasLinkage()))
825 if ((*I)->getAttr<OverloadableAttr>()) {
826 // If this declaration has the "overloadable" attribute, we
827 // might have a set of overloaded functions.
829 // Figure out what scope the identifier is in.
830 while (!(S->getFlags() & Scope::DeclScope) ||
831 !S->isDeclScope(DeclPtrTy::make(*I)))
834 // Find the last declaration in this scope (with the same
836 IdentifierResolver::iterator LastI = I;
837 for (++LastI; LastI != IEnd; ++LastI) {
838 if (!S->isDeclScope(DeclPtrTy::make(*LastI)))
849 // Perform C++ unqualified name lookup.
850 if (CppLookupName(R, S))
854 // If we didn't find a use of this identifier, and if the identifier
855 // corresponds to a compiler builtin, create the decl object for the builtin
856 // now, injecting it into translation unit scope, and return it.
857 if (AllowBuiltinCreation)
858 return LookupBuiltin(*this, R);
863 /// @brief Perform qualified name lookup in the namespaces nominated by
864 /// using directives by the given context.
866 /// C++98 [namespace.qual]p2:
867 /// Given X::m (where X is a user-declared namespace), or given ::m
868 /// (where X is the global namespace), let S be the set of all
869 /// declarations of m in X and in the transitive closure of all
870 /// namespaces nominated by using-directives in X and its used
871 /// namespaces, except that using-directives are ignored in any
872 /// namespace, including X, directly containing one or more
873 /// declarations of m. No namespace is searched more than once in
874 /// the lookup of a name. If S is the empty set, the program is
875 /// ill-formed. Otherwise, if S has exactly one member, or if the
876 /// context of the reference is a using-declaration
877 /// (namespace.udecl), S is the required set of declarations of
878 /// m. Otherwise if the use of m is not one that allows a unique
879 /// declaration to be chosen from S, the program is ill-formed.
880 /// C++98 [namespace.qual]p5:
881 /// During the lookup of a qualified namespace member name, if the
882 /// lookup finds more than one declaration of the member, and if one
883 /// declaration introduces a class name or enumeration name and the
884 /// other declarations either introduce the same object, the same
885 /// enumerator or a set of functions, the non-type name hides the
886 /// class or enumeration name if and only if the declarations are
887 /// from the same namespace; otherwise (the declarations are from
888 /// different namespaces), the program is ill-formed.
889 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
890 DeclContext *StartDC) {
891 assert(StartDC->isFileContext() && "start context is not a file context");
893 DeclContext::udir_iterator I = StartDC->using_directives_begin();
894 DeclContext::udir_iterator E = StartDC->using_directives_end();
896 if (I == E) return false;
898 // We have at least added all these contexts to the queue.
899 llvm::DenseSet<DeclContext*> Visited;
900 Visited.insert(StartDC);
902 // We have not yet looked into these namespaces, much less added
903 // their "using-children" to the queue.
904 llvm::SmallVector<NamespaceDecl*, 8> Queue;
906 // We have already looked into the initial namespace; seed the queue
907 // with its using-children.
908 for (; I != E; ++I) {
909 NamespaceDecl *ND = (*I)->getNominatedNamespace()->getOriginalNamespace();
910 if (Visited.insert(ND).second)
914 // The easiest way to implement the restriction in [namespace.qual]p5
915 // is to check whether any of the individual results found a tag
916 // and, if so, to declare an ambiguity if the final result is not
918 bool FoundTag = false;
919 bool FoundNonTag = false;
921 LookupResult LocalR(LookupResult::Temporary, R);
924 while (!Queue.empty()) {
925 NamespaceDecl *ND = Queue.back();
928 // We go through some convolutions here to avoid copying results
929 // between LookupResults.
930 bool UseLocal = !R.empty();
931 LookupResult &DirectR = UseLocal ? LocalR : R;
932 bool FoundDirect = LookupDirect(S, DirectR, ND);
935 // First do any local hiding.
936 DirectR.resolveKind();
938 // If the local result is a tag, remember that.
939 if (DirectR.isSingleTagDecl())
944 // Append the local results to the total results if necessary.
946 R.addAllDecls(LocalR);
951 // If we find names in this namespace, ignore its using directives.
957 for (llvm::tie(I,E) = ND->getUsingDirectives(); I != E; ++I) {
958 NamespaceDecl *Nom = (*I)->getNominatedNamespace();
959 if (Visited.insert(Nom).second)
960 Queue.push_back(Nom);
965 if (FoundTag && FoundNonTag)
966 R.setAmbiguousQualifiedTagHiding();
974 /// \brief Perform qualified name lookup into a given context.
976 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
977 /// names when the context of those names is explicit specified, e.g.,
978 /// "std::vector" or "x->member", or as part of unqualified name lookup.
980 /// Different lookup criteria can find different names. For example, a
981 /// particular scope can have both a struct and a function of the same
982 /// name, and each can be found by certain lookup criteria. For more
983 /// information about lookup criteria, see the documentation for the
984 /// class LookupCriteria.
986 /// \param R captures both the lookup criteria and any lookup results found.
988 /// \param LookupCtx The context in which qualified name lookup will
989 /// search. If the lookup criteria permits, name lookup may also search
990 /// in the parent contexts or (for C++ classes) base classes.
992 /// \param InUnqualifiedLookup true if this is qualified name lookup that
993 /// occurs as part of unqualified name lookup.
995 /// \returns true if lookup succeeded, false if it failed.
996 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
997 bool InUnqualifiedLookup) {
998 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
1000 if (!R.getLookupName())
1003 // Make sure that the declaration context is complete.
1004 assert((!isa<TagDecl>(LookupCtx) ||
1005 LookupCtx->isDependentContext() ||
1006 cast<TagDecl>(LookupCtx)->isDefinition() ||
1007 Context.getTypeDeclType(cast<TagDecl>(LookupCtx))->getAs<TagType>()
1008 ->isBeingDefined()) &&
1009 "Declaration context must already be complete!");
1011 // Perform qualified name lookup into the LookupCtx.
1012 if (LookupDirect(*this, R, LookupCtx)) {
1014 if (isa<CXXRecordDecl>(LookupCtx))
1015 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
1019 // Don't descend into implied contexts for redeclarations.
1020 // C++98 [namespace.qual]p6:
1021 // In a declaration for a namespace member in which the
1022 // declarator-id is a qualified-id, given that the qualified-id
1023 // for the namespace member has the form
1024 // nested-name-specifier unqualified-id
1025 // the unqualified-id shall name a member of the namespace
1026 // designated by the nested-name-specifier.
1027 // See also [class.mfct]p5 and [class.static.data]p2.
1028 if (R.isForRedeclaration())
1031 // If this is a namespace, look it up in the implied namespaces.
1032 if (LookupCtx->isFileContext())
1033 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
1035 // If this isn't a C++ class, we aren't allowed to look into base
1036 // classes, we're done.
1037 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
1041 // If we're performing qualified name lookup into a dependent class,
1042 // then we are actually looking into a current instantiation. If we have any
1043 // dependent base classes, then we either have to delay lookup until
1044 // template instantiation time (at which point all bases will be available)
1045 // or we have to fail.
1046 if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
1047 LookupRec->hasAnyDependentBases()) {
1048 R.setNotFoundInCurrentInstantiation();
1052 // Perform lookup into our base classes.
1054 Paths.setOrigin(LookupRec);
1056 // Look for this member in our base classes
1057 CXXRecordDecl::BaseMatchesCallback *BaseCallback = 0;
1058 switch (R.getLookupKind()) {
1059 case LookupOrdinaryName:
1060 case LookupMemberName:
1061 case LookupRedeclarationWithLinkage:
1062 BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
1066 BaseCallback = &CXXRecordDecl::FindTagMember;
1069 case LookupUsingDeclName:
1070 // This lookup is for redeclarations only.
1072 case LookupOperatorName:
1073 case LookupNamespaceName:
1074 case LookupObjCProtocolName:
1075 case LookupObjCImplementationName:
1076 // These lookups will never find a member in a C++ class (or base class).
1079 case LookupNestedNameSpecifierName:
1080 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember;
1084 if (!LookupRec->lookupInBases(BaseCallback,
1085 R.getLookupName().getAsOpaquePtr(), Paths))
1088 R.setNamingClass(LookupRec);
1090 // C++ [class.member.lookup]p2:
1091 // [...] If the resulting set of declarations are not all from
1092 // sub-objects of the same type, or the set has a nonstatic member
1093 // and includes members from distinct sub-objects, there is an
1094 // ambiguity and the program is ill-formed. Otherwise that set is
1095 // the result of the lookup.
1096 // FIXME: support using declarations!
1097 QualType SubobjectType;
1098 int SubobjectNumber = 0;
1099 AccessSpecifier SubobjectAccess = AS_private;
1100 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
1101 Path != PathEnd; ++Path) {
1102 const CXXBasePathElement &PathElement = Path->back();
1104 // Pick the best (i.e. most permissive i.e. numerically lowest) access
1105 // across all paths.
1106 SubobjectAccess = std::min(SubobjectAccess, Path->Access);
1108 // Determine whether we're looking at a distinct sub-object or not.
1109 if (SubobjectType.isNull()) {
1110 // This is the first subobject we've looked at. Record its type.
1111 SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
1112 SubobjectNumber = PathElement.SubobjectNumber;
1113 } else if (SubobjectType
1114 != Context.getCanonicalType(PathElement.Base->getType())) {
1115 // We found members of the given name in two subobjects of
1116 // different types. This lookup is ambiguous.
1117 R.setAmbiguousBaseSubobjectTypes(Paths);
1119 } else if (SubobjectNumber != PathElement.SubobjectNumber) {
1120 // We have a different subobject of the same type.
1122 // C++ [class.member.lookup]p5:
1123 // A static member, a nested type or an enumerator defined in
1124 // a base class T can unambiguously be found even if an object
1125 // has more than one base class subobject of type T.
1126 Decl *FirstDecl = *Path->Decls.first;
1127 if (isa<VarDecl>(FirstDecl) ||
1128 isa<TypeDecl>(FirstDecl) ||
1129 isa<EnumConstantDecl>(FirstDecl))
1132 if (isa<CXXMethodDecl>(FirstDecl)) {
1133 // Determine whether all of the methods are static.
1134 bool AllMethodsAreStatic = true;
1135 for (DeclContext::lookup_iterator Func = Path->Decls.first;
1136 Func != Path->Decls.second; ++Func) {
1137 if (!isa<CXXMethodDecl>(*Func)) {
1138 assert(isa<TagDecl>(*Func) && "Non-function must be a tag decl");
1142 if (!cast<CXXMethodDecl>(*Func)->isStatic()) {
1143 AllMethodsAreStatic = false;
1148 if (AllMethodsAreStatic)
1152 // We have found a nonstatic member name in multiple, distinct
1153 // subobjects. Name lookup is ambiguous.
1154 R.setAmbiguousBaseSubobjects(Paths);
1159 // Lookup in a base class succeeded; return these results.
1161 DeclContext::lookup_iterator I, E;
1162 for (llvm::tie(I,E) = Paths.front().Decls; I != E; ++I) {
1164 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
1172 /// @brief Performs name lookup for a name that was parsed in the
1173 /// source code, and may contain a C++ scope specifier.
1175 /// This routine is a convenience routine meant to be called from
1176 /// contexts that receive a name and an optional C++ scope specifier
1177 /// (e.g., "N::M::x"). It will then perform either qualified or
1178 /// unqualified name lookup (with LookupQualifiedName or LookupName,
1179 /// respectively) on the given name and return those results.
1181 /// @param S The scope from which unqualified name lookup will
1184 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
1186 /// @param Name The name of the entity that name lookup will
1189 /// @param Loc If provided, the source location where we're performing
1190 /// name lookup. At present, this is only used to produce diagnostics when
1191 /// C library functions (like "malloc") are implicitly declared.
1193 /// @param EnteringContext Indicates whether we are going to enter the
1194 /// context of the scope-specifier SS (if present).
1196 /// @returns True if any decls were found (but possibly ambiguous)
1197 bool Sema::LookupParsedName(LookupResult &R, Scope *S, const CXXScopeSpec *SS,
1198 bool AllowBuiltinCreation, bool EnteringContext) {
1199 if (SS && SS->isInvalid()) {
1200 // When the scope specifier is invalid, don't even look for
1205 if (SS && SS->isSet()) {
1206 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
1207 // We have resolved the scope specifier to a particular declaration
1208 // contex, and will perform name lookup in that context.
1209 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS))
1212 R.setContextRange(SS->getRange());
1214 return LookupQualifiedName(R, DC);
1217 // We could not resolve the scope specified to a specific declaration
1218 // context, which means that SS refers to an unknown specialization.
1219 // Name lookup can't find anything in this case.
1223 // Perform unqualified name lookup starting in the given scope.
1224 return LookupName(R, S, AllowBuiltinCreation);
1228 /// @brief Produce a diagnostic describing the ambiguity that resulted
1229 /// from name lookup.
1231 /// @param Result The ambiguous name lookup result.
1233 /// @param Name The name of the entity that name lookup was
1236 /// @param NameLoc The location of the name within the source code.
1238 /// @param LookupRange A source range that provides more
1239 /// source-location information concerning the lookup itself. For
1240 /// example, this range might highlight a nested-name-specifier that
1241 /// precedes the name.
1244 bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
1245 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
1247 DeclarationName Name = Result.getLookupName();
1248 SourceLocation NameLoc = Result.getNameLoc();
1249 SourceRange LookupRange = Result.getContextRange();
1251 switch (Result.getAmbiguityKind()) {
1252 case LookupResult::AmbiguousBaseSubobjects: {
1253 CXXBasePaths *Paths = Result.getBasePaths();
1254 QualType SubobjectType = Paths->front().back().Base->getType();
1255 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
1256 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
1259 DeclContext::lookup_iterator Found = Paths->front().Decls.first;
1260 while (isa<CXXMethodDecl>(*Found) &&
1261 cast<CXXMethodDecl>(*Found)->isStatic())
1264 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
1269 case LookupResult::AmbiguousBaseSubobjectTypes: {
1270 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
1271 << Name << LookupRange;
1273 CXXBasePaths *Paths = Result.getBasePaths();
1274 std::set<Decl *> DeclsPrinted;
1275 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
1276 PathEnd = Paths->end();
1277 Path != PathEnd; ++Path) {
1278 Decl *D = *Path->Decls.first;
1279 if (DeclsPrinted.insert(D).second)
1280 Diag(D->getLocation(), diag::note_ambiguous_member_found);
1286 case LookupResult::AmbiguousTagHiding: {
1287 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
1289 llvm::SmallPtrSet<NamedDecl*,8> TagDecls;
1291 LookupResult::iterator DI, DE = Result.end();
1292 for (DI = Result.begin(); DI != DE; ++DI)
1293 if (TagDecl *TD = dyn_cast<TagDecl>(*DI)) {
1294 TagDecls.insert(TD);
1295 Diag(TD->getLocation(), diag::note_hidden_tag);
1298 for (DI = Result.begin(); DI != DE; ++DI)
1299 if (!isa<TagDecl>(*DI))
1300 Diag((*DI)->getLocation(), diag::note_hiding_object);
1302 // For recovery purposes, go ahead and implement the hiding.
1303 LookupResult::Filter F = Result.makeFilter();
1304 while (F.hasNext()) {
1305 if (TagDecls.count(F.next()))
1313 case LookupResult::AmbiguousReference: {
1314 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
1316 LookupResult::iterator DI = Result.begin(), DE = Result.end();
1317 for (; DI != DE; ++DI)
1318 Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI;
1324 llvm_unreachable("unknown ambiguity kind");
1329 addAssociatedClassesAndNamespaces(QualType T,
1330 ASTContext &Context,
1331 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1332 Sema::AssociatedClassSet &AssociatedClasses);
1334 static void CollectNamespace(Sema::AssociatedNamespaceSet &Namespaces,
1336 if (Ctx->isFileContext())
1337 Namespaces.insert(Ctx);
1340 // \brief Add the associated classes and namespaces for argument-dependent
1341 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2).
1343 addAssociatedClassesAndNamespaces(const TemplateArgument &Arg,
1344 ASTContext &Context,
1345 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1346 Sema::AssociatedClassSet &AssociatedClasses) {
1347 // C++ [basic.lookup.koenig]p2, last bullet:
1349 switch (Arg.getKind()) {
1350 case TemplateArgument::Null:
1353 case TemplateArgument::Type:
1354 // [...] the namespaces and classes associated with the types of the
1355 // template arguments provided for template type parameters (excluding
1356 // template template parameters)
1357 addAssociatedClassesAndNamespaces(Arg.getAsType(), Context,
1358 AssociatedNamespaces,
1362 case TemplateArgument::Template: {
1363 // [...] the namespaces in which any template template arguments are
1364 // defined; and the classes in which any member templates used as
1365 // template template arguments are defined.
1366 TemplateName Template = Arg.getAsTemplate();
1367 if (ClassTemplateDecl *ClassTemplate
1368 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
1369 DeclContext *Ctx = ClassTemplate->getDeclContext();
1370 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1371 AssociatedClasses.insert(EnclosingClass);
1372 // Add the associated namespace for this class.
1373 while (Ctx->isRecord())
1374 Ctx = Ctx->getParent();
1375 CollectNamespace(AssociatedNamespaces, Ctx);
1380 case TemplateArgument::Declaration:
1381 case TemplateArgument::Integral:
1382 case TemplateArgument::Expression:
1383 // [Note: non-type template arguments do not contribute to the set of
1384 // associated namespaces. ]
1387 case TemplateArgument::Pack:
1388 for (TemplateArgument::pack_iterator P = Arg.pack_begin(),
1389 PEnd = Arg.pack_end();
1391 addAssociatedClassesAndNamespaces(*P, Context,
1392 AssociatedNamespaces,
1398 // \brief Add the associated classes and namespaces for
1399 // argument-dependent lookup with an argument of class type
1400 // (C++ [basic.lookup.koenig]p2).
1402 addAssociatedClassesAndNamespaces(CXXRecordDecl *Class,
1403 ASTContext &Context,
1404 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1405 Sema::AssociatedClassSet &AssociatedClasses) {
1406 // C++ [basic.lookup.koenig]p2:
1408 // -- If T is a class type (including unions), its associated
1409 // classes are: the class itself; the class of which it is a
1410 // member, if any; and its direct and indirect base
1411 // classes. Its associated namespaces are the namespaces in
1412 // which its associated classes are defined.
1414 // Add the class of which it is a member, if any.
1415 DeclContext *Ctx = Class->getDeclContext();
1416 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1417 AssociatedClasses.insert(EnclosingClass);
1418 // Add the associated namespace for this class.
1419 while (Ctx->isRecord())
1420 Ctx = Ctx->getParent();
1421 CollectNamespace(AssociatedNamespaces, Ctx);
1423 // Add the class itself. If we've already seen this class, we don't
1424 // need to visit base classes.
1425 if (!AssociatedClasses.insert(Class))
1428 // -- If T is a template-id, its associated namespaces and classes are
1429 // the namespace in which the template is defined; for member
1430 // templates, the member template’s class; the namespaces and classes
1431 // associated with the types of the template arguments provided for
1432 // template type parameters (excluding template template parameters); the
1433 // namespaces in which any template template arguments are defined; and
1434 // the classes in which any member templates used as template template
1435 // arguments are defined. [Note: non-type template arguments do not
1436 // contribute to the set of associated namespaces. ]
1437 if (ClassTemplateSpecializationDecl *Spec
1438 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
1439 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
1440 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1441 AssociatedClasses.insert(EnclosingClass);
1442 // Add the associated namespace for this class.
1443 while (Ctx->isRecord())
1444 Ctx = Ctx->getParent();
1445 CollectNamespace(AssociatedNamespaces, Ctx);
1447 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
1448 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
1449 addAssociatedClassesAndNamespaces(TemplateArgs[I], Context,
1450 AssociatedNamespaces,
1454 // Only recurse into base classes for complete types.
1455 if (!Class->hasDefinition()) {
1456 // FIXME: we might need to instantiate templates here
1460 // Add direct and indirect base classes along with their associated
1462 llvm::SmallVector<CXXRecordDecl *, 32> Bases;
1463 Bases.push_back(Class);
1464 while (!Bases.empty()) {
1465 // Pop this class off the stack.
1466 Class = Bases.back();
1469 // Visit the base classes.
1470 for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(),
1471 BaseEnd = Class->bases_end();
1472 Base != BaseEnd; ++Base) {
1473 const RecordType *BaseType = Base->getType()->getAs<RecordType>();
1474 // In dependent contexts, we do ADL twice, and the first time around,
1475 // the base type might be a dependent TemplateSpecializationType, or a
1476 // TemplateTypeParmType. If that happens, simply ignore it.
1477 // FIXME: If we want to support export, we probably need to add the
1478 // namespace of the template in a TemplateSpecializationType, or even
1479 // the classes and namespaces of known non-dependent arguments.
1482 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
1483 if (AssociatedClasses.insert(BaseDecl)) {
1484 // Find the associated namespace for this base class.
1485 DeclContext *BaseCtx = BaseDecl->getDeclContext();
1486 while (BaseCtx->isRecord())
1487 BaseCtx = BaseCtx->getParent();
1488 CollectNamespace(AssociatedNamespaces, BaseCtx);
1490 // Make sure we visit the bases of this base class.
1491 if (BaseDecl->bases_begin() != BaseDecl->bases_end())
1492 Bases.push_back(BaseDecl);
1498 // \brief Add the associated classes and namespaces for
1499 // argument-dependent lookup with an argument of type T
1500 // (C++ [basic.lookup.koenig]p2).
1502 addAssociatedClassesAndNamespaces(QualType T,
1503 ASTContext &Context,
1504 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1505 Sema::AssociatedClassSet &AssociatedClasses) {
1506 // C++ [basic.lookup.koenig]p2:
1508 // For each argument type T in the function call, there is a set
1509 // of zero or more associated namespaces and a set of zero or more
1510 // associated classes to be considered. The sets of namespaces and
1511 // classes is determined entirely by the types of the function
1512 // arguments (and the namespace of any template template
1513 // argument). Typedef names and using-declarations used to specify
1514 // the types do not contribute to this set. The sets of namespaces
1515 // and classes are determined in the following way:
1516 T = Context.getCanonicalType(T).getUnqualifiedType();
1518 // -- If T is a pointer to U or an array of U, its associated
1519 // namespaces and classes are those associated with U.
1521 // We handle this by unwrapping pointer and array types immediately,
1522 // to avoid unnecessary recursion.
1524 if (const PointerType *Ptr = T->getAs<PointerType>())
1525 T = Ptr->getPointeeType();
1526 else if (const ArrayType *Ptr = Context.getAsArrayType(T))
1527 T = Ptr->getElementType();
1532 // -- If T is a fundamental type, its associated sets of
1533 // namespaces and classes are both empty.
1534 if (T->getAs<BuiltinType>())
1537 // -- If T is a class type (including unions), its associated
1538 // classes are: the class itself; the class of which it is a
1539 // member, if any; and its direct and indirect base
1540 // classes. Its associated namespaces are the namespaces in
1541 // which its associated classes are defined.
1542 if (const RecordType *ClassType = T->getAs<RecordType>())
1543 if (CXXRecordDecl *ClassDecl
1544 = dyn_cast<CXXRecordDecl>(ClassType->getDecl())) {
1545 addAssociatedClassesAndNamespaces(ClassDecl, Context,
1546 AssociatedNamespaces,
1551 // -- If T is an enumeration type, its associated namespace is
1552 // the namespace in which it is defined. If it is class
1553 // member, its associated class is the member’s class; else
1554 // it has no associated class.
1555 if (const EnumType *EnumT = T->getAs<EnumType>()) {
1556 EnumDecl *Enum = EnumT->getDecl();
1558 DeclContext *Ctx = Enum->getDeclContext();
1559 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1560 AssociatedClasses.insert(EnclosingClass);
1562 // Add the associated namespace for this class.
1563 while (Ctx->isRecord())
1564 Ctx = Ctx->getParent();
1565 CollectNamespace(AssociatedNamespaces, Ctx);
1570 // -- If T is a function type, its associated namespaces and
1571 // classes are those associated with the function parameter
1572 // types and those associated with the return type.
1573 if (const FunctionType *FnType = T->getAs<FunctionType>()) {
1575 addAssociatedClassesAndNamespaces(FnType->getResultType(),
1577 AssociatedNamespaces, AssociatedClasses);
1579 const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FnType);
1584 for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(),
1585 ArgEnd = Proto->arg_type_end();
1586 Arg != ArgEnd; ++Arg)
1587 addAssociatedClassesAndNamespaces(*Arg, Context,
1588 AssociatedNamespaces, AssociatedClasses);
1593 // -- If T is a pointer to a member function of a class X, its
1594 // associated namespaces and classes are those associated
1595 // with the function parameter types and return type,
1596 // together with those associated with X.
1598 // -- If T is a pointer to a data member of class X, its
1599 // associated namespaces and classes are those associated
1600 // with the member type together with those associated with
1602 if (const MemberPointerType *MemberPtr = T->getAs<MemberPointerType>()) {
1603 // Handle the type that the pointer to member points to.
1604 addAssociatedClassesAndNamespaces(MemberPtr->getPointeeType(),
1606 AssociatedNamespaces,
1609 // Handle the class type into which this points.
1610 if (const RecordType *Class = MemberPtr->getClass()->getAs<RecordType>())
1611 addAssociatedClassesAndNamespaces(cast<CXXRecordDecl>(Class->getDecl()),
1613 AssociatedNamespaces,
1619 // FIXME: What about block pointers?
1620 // FIXME: What about Objective-C message sends?
1623 /// \brief Find the associated classes and namespaces for
1624 /// argument-dependent lookup for a call with the given set of
1627 /// This routine computes the sets of associated classes and associated
1628 /// namespaces searched by argument-dependent lookup
1629 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
1631 Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs,
1632 AssociatedNamespaceSet &AssociatedNamespaces,
1633 AssociatedClassSet &AssociatedClasses) {
1634 AssociatedNamespaces.clear();
1635 AssociatedClasses.clear();
1637 // C++ [basic.lookup.koenig]p2:
1638 // For each argument type T in the function call, there is a set
1639 // of zero or more associated namespaces and a set of zero or more
1640 // associated classes to be considered. The sets of namespaces and
1641 // classes is determined entirely by the types of the function
1642 // arguments (and the namespace of any template template
1644 for (unsigned ArgIdx = 0; ArgIdx != NumArgs; ++ArgIdx) {
1645 Expr *Arg = Args[ArgIdx];
1647 if (Arg->getType() != Context.OverloadTy) {
1648 addAssociatedClassesAndNamespaces(Arg->getType(), Context,
1649 AssociatedNamespaces,
1654 // [...] In addition, if the argument is the name or address of a
1655 // set of overloaded functions and/or function templates, its
1656 // associated classes and namespaces are the union of those
1657 // associated with each of the members of the set: the namespace
1658 // in which the function or function template is defined and the
1659 // classes and namespaces associated with its (non-dependent)
1660 // parameter types and return type.
1661 Arg = Arg->IgnoreParens();
1662 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg))
1663 if (unaryOp->getOpcode() == UnaryOperator::AddrOf)
1664 Arg = unaryOp->getSubExpr();
1666 // TODO: avoid the copies. This should be easy when the cases
1667 // share a storage implementation.
1668 llvm::SmallVector<NamedDecl*, 8> Functions;
1670 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg))
1671 Functions.append(ULE->decls_begin(), ULE->decls_end());
1675 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Functions.begin(),
1676 E = Functions.end(); I != E; ++I) {
1677 // Look through any using declarations to find the underlying function.
1678 NamedDecl *Fn = (*I)->getUnderlyingDecl();
1680 FunctionDecl *FDecl = dyn_cast<FunctionDecl>(Fn);
1682 FDecl = cast<FunctionTemplateDecl>(Fn)->getTemplatedDecl();
1684 // Add the classes and namespaces associated with the parameter
1685 // types and return type of this function.
1686 addAssociatedClassesAndNamespaces(FDecl->getType(), Context,
1687 AssociatedNamespaces,
1693 /// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
1694 /// an acceptable non-member overloaded operator for a call whose
1695 /// arguments have types T1 (and, if non-empty, T2). This routine
1696 /// implements the check in C++ [over.match.oper]p3b2 concerning
1697 /// enumeration types.
1699 IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn,
1700 QualType T1, QualType T2,
1701 ASTContext &Context) {
1702 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
1705 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
1708 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
1709 if (Proto->getNumArgs() < 1)
1712 if (T1->isEnumeralType()) {
1713 QualType ArgType = Proto->getArgType(0).getNonReferenceType();
1714 if (Context.hasSameUnqualifiedType(T1, ArgType))
1718 if (Proto->getNumArgs() < 2)
1721 if (!T2.isNull() && T2->isEnumeralType()) {
1722 QualType ArgType = Proto->getArgType(1).getNonReferenceType();
1723 if (Context.hasSameUnqualifiedType(T2, ArgType))
1730 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
1731 LookupNameKind NameKind,
1732 RedeclarationKind Redecl) {
1733 LookupResult R(*this, Name, SourceLocation(), NameKind, Redecl);
1735 return R.getAsSingle<NamedDecl>();
1738 /// \brief Find the protocol with the given name, if any.
1739 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II) {
1740 Decl *D = LookupSingleName(TUScope, II, LookupObjCProtocolName);
1741 return cast_or_null<ObjCProtocolDecl>(D);
1744 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
1745 QualType T1, QualType T2,
1746 UnresolvedSetImpl &Functions) {
1747 // C++ [over.match.oper]p3:
1748 // -- The set of non-member candidates is the result of the
1749 // unqualified lookup of operator@ in the context of the
1750 // expression according to the usual rules for name lookup in
1751 // unqualified function calls (3.4.2) except that all member
1752 // functions are ignored. However, if no operand has a class
1753 // type, only those non-member functions in the lookup set
1754 // that have a first parameter of type T1 or "reference to
1755 // (possibly cv-qualified) T1", when T1 is an enumeration
1756 // type, or (if there is a right operand) a second parameter
1757 // of type T2 or "reference to (possibly cv-qualified) T2",
1758 // when T2 is an enumeration type, are candidate functions.
1759 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
1760 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
1761 LookupName(Operators, S);
1763 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
1765 if (Operators.empty())
1768 for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end();
1769 Op != OpEnd; ++Op) {
1770 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Op)) {
1771 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context))
1772 Functions.addDecl(FD, Op.getAccess()); // FIXME: canonical FD
1773 } else if (FunctionTemplateDecl *FunTmpl
1774 = dyn_cast<FunctionTemplateDecl>(*Op)) {
1775 // FIXME: friend operators?
1776 // FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate,
1778 if (!FunTmpl->getDeclContext()->isRecord())
1779 Functions.addDecl(FunTmpl, Op.getAccess());
1784 void ADLResult::insert(NamedDecl *New) {
1785 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
1787 // If we haven't yet seen a decl for this key, or the last decl
1788 // was exactly this one, we're done.
1789 if (Old == 0 || Old == New) {
1794 // Otherwise, decide which is a more recent redeclaration.
1795 FunctionDecl *OldFD, *NewFD;
1796 if (isa<FunctionTemplateDecl>(New)) {
1797 OldFD = cast<FunctionTemplateDecl>(Old)->getTemplatedDecl();
1798 NewFD = cast<FunctionTemplateDecl>(New)->getTemplatedDecl();
1800 OldFD = cast<FunctionDecl>(Old);
1801 NewFD = cast<FunctionDecl>(New);
1804 FunctionDecl *Cursor = NewFD;
1806 Cursor = Cursor->getPreviousDeclaration();
1808 // If we got to the end without finding OldFD, OldFD is the newer
1809 // declaration; leave things as they are.
1810 if (!Cursor) return;
1812 // If we do find OldFD, then NewFD is newer.
1813 if (Cursor == OldFD) break;
1815 // Otherwise, keep looking.
1821 void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator,
1822 Expr **Args, unsigned NumArgs,
1823 ADLResult &Result) {
1824 // Find all of the associated namespaces and classes based on the
1825 // arguments we have.
1826 AssociatedNamespaceSet AssociatedNamespaces;
1827 AssociatedClassSet AssociatedClasses;
1828 FindAssociatedClassesAndNamespaces(Args, NumArgs,
1829 AssociatedNamespaces,
1834 T1 = Args[0]->getType();
1836 T2 = Args[1]->getType();
1839 // C++ [basic.lookup.argdep]p3:
1840 // Let X be the lookup set produced by unqualified lookup (3.4.1)
1841 // and let Y be the lookup set produced by argument dependent
1842 // lookup (defined as follows). If X contains [...] then Y is
1843 // empty. Otherwise Y is the set of declarations found in the
1844 // namespaces associated with the argument types as described
1845 // below. The set of declarations found by the lookup of the name
1846 // is the union of X and Y.
1848 // Here, we compute Y and add its members to the overloaded
1850 for (AssociatedNamespaceSet::iterator NS = AssociatedNamespaces.begin(),
1851 NSEnd = AssociatedNamespaces.end();
1852 NS != NSEnd; ++NS) {
1853 // When considering an associated namespace, the lookup is the
1854 // same as the lookup performed when the associated namespace is
1855 // used as a qualifier (3.4.3.2) except that:
1857 // -- Any using-directives in the associated namespace are
1860 // -- Any namespace-scope friend functions declared in
1861 // associated classes are visible within their respective
1862 // namespaces even if they are not visible during an ordinary
1864 DeclContext::lookup_iterator I, E;
1865 for (llvm::tie(I, E) = (*NS)->lookup(Name); I != E; ++I) {
1867 // If the only declaration here is an ordinary friend, consider
1868 // it only if it was declared in an associated classes.
1869 if (D->getIdentifierNamespace() == Decl::IDNS_OrdinaryFriend) {
1870 DeclContext *LexDC = D->getLexicalDeclContext();
1871 if (!AssociatedClasses.count(cast<CXXRecordDecl>(LexDC)))
1875 if (isa<UsingShadowDecl>(D))
1876 D = cast<UsingShadowDecl>(D)->getTargetDecl();
1878 if (isa<FunctionDecl>(D)) {
1880 !IsAcceptableNonMemberOperatorCandidate(cast<FunctionDecl>(D),
1883 } else if (!isa<FunctionTemplateDecl>(D))
1891 //----------------------------------------------------------------------------
1892 // Search for all visible declarations.
1893 //----------------------------------------------------------------------------
1894 VisibleDeclConsumer::~VisibleDeclConsumer() { }
1898 class ShadowContextRAII;
1900 class VisibleDeclsRecord {
1902 /// \brief An entry in the shadow map, which is optimized to store a
1903 /// single declaration (the common case) but can also store a list
1904 /// of declarations.
1905 class ShadowMapEntry {
1906 typedef llvm::SmallVector<NamedDecl *, 4> DeclVector;
1908 /// \brief Contains either the solitary NamedDecl * or a vector
1909 /// of declarations.
1910 llvm::PointerUnion<NamedDecl *, DeclVector*> DeclOrVector;
1913 ShadowMapEntry() : DeclOrVector() { }
1915 void Add(NamedDecl *ND);
1919 typedef NamedDecl **iterator;
1925 /// \brief A mapping from declaration names to the declarations that have
1926 /// this name within a particular scope.
1927 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
1929 /// \brief A list of shadow maps, which is used to model name hiding.
1930 std::list<ShadowMap> ShadowMaps;
1932 /// \brief The declaration contexts we have already visited.
1933 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
1935 friend class ShadowContextRAII;
1938 /// \brief Determine whether we have already visited this context
1939 /// (and, if not, note that we are going to visit that context now).
1940 bool visitedContext(DeclContext *Ctx) {
1941 return !VisitedContexts.insert(Ctx);
1944 /// \brief Determine whether the given declaration is hidden in the
1947 /// \returns the declaration that hides the given declaration, or
1948 /// NULL if no such declaration exists.
1949 NamedDecl *checkHidden(NamedDecl *ND);
1951 /// \brief Add a declaration to the current shadow map.
1952 void add(NamedDecl *ND) { ShadowMaps.back()[ND->getDeclName()].Add(ND); }
1955 /// \brief RAII object that records when we've entered a shadow context.
1956 class ShadowContextRAII {
1957 VisibleDeclsRecord &Visible;
1959 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
1962 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
1963 Visible.ShadowMaps.push_back(ShadowMap());
1966 ~ShadowContextRAII() {
1967 for (ShadowMap::iterator E = Visible.ShadowMaps.back().begin(),
1968 EEnd = Visible.ShadowMaps.back().end();
1971 E->second.Destroy();
1973 Visible.ShadowMaps.pop_back();
1977 } // end anonymous namespace
1979 void VisibleDeclsRecord::ShadowMapEntry::Add(NamedDecl *ND) {
1980 if (DeclOrVector.isNull()) {
1981 // 0 - > 1 elements: just set the single element information.
1986 if (NamedDecl *PrevND = DeclOrVector.dyn_cast<NamedDecl *>()) {
1987 // 1 -> 2 elements: create the vector of results and push in the
1988 // existing declaration.
1989 DeclVector *Vec = new DeclVector;
1990 Vec->push_back(PrevND);
1994 // Add the new element to the end of the vector.
1995 DeclOrVector.get<DeclVector*>()->push_back(ND);
1998 void VisibleDeclsRecord::ShadowMapEntry::Destroy() {
1999 if (DeclVector *Vec = DeclOrVector.dyn_cast<DeclVector *>()) {
2001 DeclOrVector = ((NamedDecl *)0);
2005 VisibleDeclsRecord::ShadowMapEntry::iterator
2006 VisibleDeclsRecord::ShadowMapEntry::begin() {
2007 if (DeclOrVector.isNull())
2010 if (DeclOrVector.dyn_cast<NamedDecl *>())
2011 return &reinterpret_cast<NamedDecl*&>(DeclOrVector);
2013 return DeclOrVector.get<DeclVector *>()->begin();
2016 VisibleDeclsRecord::ShadowMapEntry::iterator
2017 VisibleDeclsRecord::ShadowMapEntry::end() {
2018 if (DeclOrVector.isNull())
2021 if (DeclOrVector.dyn_cast<NamedDecl *>())
2022 return &reinterpret_cast<NamedDecl*&>(DeclOrVector) + 1;
2024 return DeclOrVector.get<DeclVector *>()->end();
2027 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
2028 // Look through using declarations.
2029 ND = ND->getUnderlyingDecl();
2031 unsigned IDNS = ND->getIdentifierNamespace();
2032 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
2033 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
2034 SM != SMEnd; ++SM) {
2035 ShadowMap::iterator Pos = SM->find(ND->getDeclName());
2036 if (Pos == SM->end())
2039 for (ShadowMapEntry::iterator I = Pos->second.begin(),
2040 IEnd = Pos->second.end();
2042 // A tag declaration does not hide a non-tag declaration.
2043 if ((*I)->getIdentifierNamespace() == Decl::IDNS_Tag &&
2044 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
2045 Decl::IDNS_ObjCProtocol)))
2048 // Protocols are in distinct namespaces from everything else.
2049 if ((((*I)->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
2050 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
2051 (*I)->getIdentifierNamespace() != IDNS)
2054 // Functions and function templates in the same scope overload
2055 // rather than hide. FIXME: Look for hiding based on function
2057 if ((*I)->isFunctionOrFunctionTemplate() &&
2058 ND->isFunctionOrFunctionTemplate() &&
2059 SM == ShadowMaps.rbegin())
2062 // We've found a declaration that hides this one.
2070 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
2071 bool QualifiedNameLookup,
2073 VisibleDeclConsumer &Consumer,
2074 VisibleDeclsRecord &Visited) {
2078 // Make sure we don't visit the same context twice.
2079 if (Visited.visitedContext(Ctx->getPrimaryContext()))
2082 // Enumerate all of the results in this context.
2083 for (DeclContext *CurCtx = Ctx->getPrimaryContext(); CurCtx;
2084 CurCtx = CurCtx->getNextContext()) {
2085 for (DeclContext::decl_iterator D = CurCtx->decls_begin(),
2086 DEnd = CurCtx->decls_end();
2088 if (NamedDecl *ND = dyn_cast<NamedDecl>(*D))
2089 if (Result.isAcceptableDecl(ND)) {
2090 Consumer.FoundDecl(ND, Visited.checkHidden(ND), InBaseClass);
2094 // Visit transparent contexts inside this context.
2095 if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D)) {
2096 if (InnerCtx->isTransparentContext())
2097 LookupVisibleDecls(InnerCtx, Result, QualifiedNameLookup, InBaseClass,
2103 // Traverse using directives for qualified name lookup.
2104 if (QualifiedNameLookup) {
2105 ShadowContextRAII Shadow(Visited);
2106 DeclContext::udir_iterator I, E;
2107 for (llvm::tie(I, E) = Ctx->getUsingDirectives(); I != E; ++I) {
2108 LookupVisibleDecls((*I)->getNominatedNamespace(), Result,
2109 QualifiedNameLookup, InBaseClass, Consumer, Visited);
2113 // Traverse the contexts of inherited C++ classes.
2114 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
2115 if (!Record->hasDefinition())
2118 for (CXXRecordDecl::base_class_iterator B = Record->bases_begin(),
2119 BEnd = Record->bases_end();
2121 QualType BaseType = B->getType();
2123 // Don't look into dependent bases, because name lookup can't look
2125 if (BaseType->isDependentType())
2128 const RecordType *Record = BaseType->getAs<RecordType>();
2132 // FIXME: It would be nice to be able to determine whether referencing
2133 // a particular member would be ambiguous. For example, given
2135 // struct A { int member; };
2136 // struct B { int member; };
2137 // struct C : A, B { };
2139 // void f(C *c) { c->### }
2141 // accessing 'member' would result in an ambiguity. However, we
2142 // could be smart enough to qualify the member with the base
2151 // Find results in this base class (and its bases).
2152 ShadowContextRAII Shadow(Visited);
2153 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup,
2154 true, Consumer, Visited);
2158 // Traverse the contexts of Objective-C classes.
2159 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
2160 // Traverse categories.
2161 for (ObjCCategoryDecl *Category = IFace->getCategoryList();
2162 Category; Category = Category->getNextClassCategory()) {
2163 ShadowContextRAII Shadow(Visited);
2164 LookupVisibleDecls(Category, Result, QualifiedNameLookup, false,
2168 // Traverse protocols.
2169 for (ObjCInterfaceDecl::protocol_iterator I = IFace->protocol_begin(),
2170 E = IFace->protocol_end(); I != E; ++I) {
2171 ShadowContextRAII Shadow(Visited);
2172 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer,
2176 // Traverse the superclass.
2177 if (IFace->getSuperClass()) {
2178 ShadowContextRAII Shadow(Visited);
2179 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup,
2180 true, Consumer, Visited);
2182 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
2183 for (ObjCProtocolDecl::protocol_iterator I = Protocol->protocol_begin(),
2184 E = Protocol->protocol_end(); I != E; ++I) {
2185 ShadowContextRAII Shadow(Visited);
2186 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer,
2189 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
2190 for (ObjCCategoryDecl::protocol_iterator I = Category->protocol_begin(),
2191 E = Category->protocol_end(); I != E; ++I) {
2192 ShadowContextRAII Shadow(Visited);
2193 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer,
2199 static void LookupVisibleDecls(Scope *S, LookupResult &Result,
2200 UnqualUsingDirectiveSet &UDirs,
2201 VisibleDeclConsumer &Consumer,
2202 VisibleDeclsRecord &Visited) {
2206 if (!S->getEntity() || !S->getParent() ||
2207 ((DeclContext *)S->getEntity())->isFunctionOrMethod()) {
2208 // Walk through the declarations in this Scope.
2209 for (Scope::decl_iterator D = S->decl_begin(), DEnd = S->decl_end();
2211 if (NamedDecl *ND = dyn_cast<NamedDecl>((Decl *)((*D).get())))
2212 if (Result.isAcceptableDecl(ND)) {
2213 Consumer.FoundDecl(ND, Visited.checkHidden(ND), false);
2219 DeclContext *Entity = 0;
2220 if (S->getEntity()) {
2221 // Look into this scope's declaration context, along with any of its
2222 // parent lookup contexts (e.g., enclosing classes), up to the point
2223 // where we hit the context stored in the next outer scope.
2224 Entity = (DeclContext *)S->getEntity();
2225 DeclContext *OuterCtx = findOuterContext(S);
2227 for (DeclContext *Ctx = Entity; Ctx && Ctx->getPrimaryContext() != OuterCtx;
2228 Ctx = Ctx->getLookupParent()) {
2229 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
2230 if (Method->isInstanceMethod()) {
2231 // For instance methods, look for ivars in the method's interface.
2232 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
2233 Result.getNameLoc(), Sema::LookupMemberName);
2234 if (ObjCInterfaceDecl *IFace = Method->getClassInterface())
2235 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false,
2236 /*InBaseClass=*/false, Consumer, Visited);
2239 // We've already performed all of the name lookup that we need
2240 // to for Objective-C methods; the next context will be the
2245 if (Ctx->isFunctionOrMethod())
2248 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false,
2249 /*InBaseClass=*/false, Consumer, Visited);
2251 } else if (!S->getParent()) {
2252 // Look into the translation unit scope. We walk through the translation
2253 // unit's declaration context, because the Scope itself won't have all of
2254 // the declarations if we loaded a precompiled header.
2255 // FIXME: We would like the translation unit's Scope object to point to the
2256 // translation unit, so we don't need this special "if" branch. However,
2257 // doing so would force the normal C++ name-lookup code to look into the
2258 // translation unit decl when the IdentifierInfo chains would suffice.
2259 // Once we fix that problem (which is part of a more general "don't look
2260 // in DeclContexts unless we have to" optimization), we can eliminate this.
2261 Entity = Result.getSema().Context.getTranslationUnitDecl();
2262 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false,
2263 /*InBaseClass=*/false, Consumer, Visited);
2267 // Lookup visible declarations in any namespaces found by using
2269 UnqualUsingDirectiveSet::const_iterator UI, UEnd;
2270 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(Entity);
2271 for (; UI != UEnd; ++UI)
2272 LookupVisibleDecls(const_cast<DeclContext *>(UI->getNominatedNamespace()),
2273 Result, /*QualifiedNameLookup=*/false,
2274 /*InBaseClass=*/false, Consumer, Visited);
2277 // Lookup names in the parent scope.
2278 ShadowContextRAII Shadow(Visited);
2279 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited);
2282 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
2283 VisibleDeclConsumer &Consumer) {
2284 // Determine the set of using directives available during
2285 // unqualified name lookup.
2287 UnqualUsingDirectiveSet UDirs;
2288 if (getLangOptions().CPlusPlus) {
2289 // Find the first namespace or translation-unit scope.
2290 while (S && !isNamespaceOrTranslationUnitScope(S))
2293 UDirs.visitScopeChain(Initial, S);
2297 // Look for visible declarations.
2298 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
2299 VisibleDeclsRecord Visited;
2300 ShadowContextRAII Shadow(Visited);
2301 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited);
2304 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
2305 VisibleDeclConsumer &Consumer) {
2306 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
2307 VisibleDeclsRecord Visited;
2308 ShadowContextRAII Shadow(Visited);
2309 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true,
2310 /*InBaseClass=*/false, Consumer, Visited);
2313 //----------------------------------------------------------------------------
2315 //----------------------------------------------------------------------------
2318 class TypoCorrectionConsumer : public VisibleDeclConsumer {
2319 /// \brief The name written that is a typo in the source.
2320 llvm::StringRef Typo;
2322 /// \brief The results found that have the smallest edit distance
2323 /// found (so far) with the typo name.
2324 llvm::SmallVector<NamedDecl *, 4> BestResults;
2326 /// \brief The best edit distance found so far.
2327 unsigned BestEditDistance;
2330 explicit TypoCorrectionConsumer(IdentifierInfo *Typo)
2331 : Typo(Typo->getName()) { }
2333 virtual void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, bool InBaseClass);
2335 typedef llvm::SmallVector<NamedDecl *, 4>::const_iterator iterator;
2336 iterator begin() const { return BestResults.begin(); }
2337 iterator end() const { return BestResults.end(); }
2338 bool empty() const { return BestResults.empty(); }
2340 unsigned getBestEditDistance() const { return BestEditDistance; }
2345 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
2347 // Don't consider hidden names for typo correction.
2351 // Only consider entities with identifiers for names, ignoring
2352 // special names (constructors, overloaded operators, selectors,
2354 IdentifierInfo *Name = ND->getIdentifier();
2358 // Compute the edit distance between the typo and the name of this
2359 // entity. If this edit distance is not worse than the best edit
2360 // distance we've seen so far, add it to the list of results.
2361 unsigned ED = Typo.edit_distance(Name->getName());
2362 if (!BestResults.empty()) {
2363 if (ED < BestEditDistance) {
2364 // This result is better than any we've seen before; clear out
2365 // the previous results.
2366 BestResults.clear();
2367 BestEditDistance = ED;
2368 } else if (ED > BestEditDistance) {
2369 // This result is worse than the best results we've seen so far;
2374 BestEditDistance = ED;
2376 BestResults.push_back(ND);
2379 /// \brief Try to "correct" a typo in the source code by finding
2380 /// visible declarations whose names are similar to the name that was
2381 /// present in the source code.
2383 /// \param Res the \c LookupResult structure that contains the name
2384 /// that was present in the source code along with the name-lookup
2385 /// criteria used to search for the name. On success, this structure
2386 /// will contain the results of name lookup.
2388 /// \param S the scope in which name lookup occurs.
2390 /// \param SS the nested-name-specifier that precedes the name we're
2391 /// looking for, if present.
2393 /// \param MemberContext if non-NULL, the context in which to look for
2394 /// a member access expression.
2396 /// \param EnteringContext whether we're entering the context described by
2397 /// the nested-name-specifier SS.
2399 /// \param OPT when non-NULL, the search for visible declarations will
2400 /// also walk the protocols in the qualified interfaces of \p OPT.
2402 /// \returns true if the typo was corrected, in which case the \p Res
2403 /// structure will contain the results of name lookup for the
2404 /// corrected name. Otherwise, returns false.
2405 bool Sema::CorrectTypo(LookupResult &Res, Scope *S, const CXXScopeSpec *SS,
2406 DeclContext *MemberContext, bool EnteringContext,
2407 const ObjCObjectPointerType *OPT) {
2408 if (Diags.hasFatalErrorOccurred())
2411 // Provide a stop gap for files that are just seriously broken. Trying
2412 // to correct all typos can turn into a HUGE performance penalty, causing
2413 // some files to take minutes to get rejected by the parser.
2414 // FIXME: Is this the right solution?
2415 if (TyposCorrected == 20)
2419 // We only attempt to correct typos for identifiers.
2420 IdentifierInfo *Typo = Res.getLookupName().getAsIdentifierInfo();
2424 // If the scope specifier itself was invalid, don't try to correct
2426 if (SS && SS->isInvalid())
2429 // Never try to correct typos during template deduction or
2431 if (!ActiveTemplateInstantiations.empty())
2434 TypoCorrectionConsumer Consumer(Typo);
2435 if (MemberContext) {
2436 LookupVisibleDecls(MemberContext, Res.getLookupKind(), Consumer);
2438 // Look in qualified interfaces.
2440 for (ObjCObjectPointerType::qual_iterator
2441 I = OPT->qual_begin(), E = OPT->qual_end();
2443 LookupVisibleDecls(*I, Res.getLookupKind(), Consumer);
2445 } else if (SS && SS->isSet()) {
2446 DeclContext *DC = computeDeclContext(*SS, EnteringContext);
2450 LookupVisibleDecls(DC, Res.getLookupKind(), Consumer);
2452 LookupVisibleDecls(S, Res.getLookupKind(), Consumer);
2455 if (Consumer.empty())
2458 // Only allow a single, closest name in the result set (it's okay to
2459 // have overloads of that name, though).
2460 TypoCorrectionConsumer::iterator I = Consumer.begin();
2461 DeclarationName BestName = (*I)->getDeclName();
2463 // If we've found an Objective-C ivar or property, don't perform
2464 // name lookup again; we'll just return the result directly.
2465 NamedDecl *FoundBest = 0;
2466 if (isa<ObjCIvarDecl>(*I) || isa<ObjCPropertyDecl>(*I))
2469 for(TypoCorrectionConsumer::iterator IEnd = Consumer.end(); I != IEnd; ++I) {
2470 if (BestName != (*I)->getDeclName())
2473 // FIXME: If there are both ivars and properties of the same name,
2474 // don't return both because the callee can't handle two
2475 // results. We really need to separate ivar lookup from property
2476 // lookup to avoid this problem.
2480 // BestName is the closest viable name to what the user
2481 // typed. However, to make sure that we don't pick something that's
2482 // way off, make sure that the user typed at least 3 characters for
2484 unsigned ED = Consumer.getBestEditDistance();
2485 if (ED == 0 || (BestName.getAsIdentifierInfo()->getName().size() / ED) < 3)
2488 // Perform name lookup again with the name we chose, and declare
2489 // success if we found something that was not ambiguous.
2491 Res.setLookupName(BestName);
2493 // If we found an ivar or property, add that result; no further
2494 // lookup is required.
2496 Res.addDecl(FoundBest);
2497 // If we're looking into the context of a member, perform qualified
2498 // name lookup on the best name.
2499 else if (MemberContext)
2500 LookupQualifiedName(Res, MemberContext);
2501 // Perform lookup as if we had just parsed the best name.
2503 LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
2506 if (Res.isAmbiguous()) {
2507 Res.suppressDiagnostics();
2511 return Res.getResultKind() != LookupResult::NotFound;