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());
549 // Perform template argument deduction against the type that we would
550 // expect the function to have.
551 if (R.getSema().DeduceTemplateArguments(ConvTemplate, 0, ExpectedType,
552 Specialization, Info)
553 == Sema::TDK_Success) {
554 R.addDecl(Specialization);
562 // Performs C++ unqualified lookup into the given file context.
564 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context,
565 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
567 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
569 // Perform direct name lookup into the LookupCtx.
570 bool Found = LookupDirect(S, R, NS);
572 // Perform direct name lookup into the namespaces nominated by the
573 // using directives whose common ancestor is this namespace.
574 UnqualUsingDirectiveSet::const_iterator UI, UEnd;
575 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(NS);
577 for (; UI != UEnd; ++UI)
578 if (LookupDirect(S, R, UI->getNominatedNamespace()))
586 static bool isNamespaceOrTranslationUnitScope(Scope *S) {
587 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()))
588 return Ctx->isFileContext();
592 // Find the next outer declaration context corresponding to this scope.
593 static DeclContext *findOuterContext(Scope *S) {
594 for (S = S->getParent(); S; S = S->getParent())
596 return static_cast<DeclContext *>(S->getEntity())->getPrimaryContext();
601 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
602 assert(getLangOptions().CPlusPlus && "Can perform only C++ lookup");
604 DeclarationName Name = R.getLookupName();
607 IdentifierResolver::iterator
608 I = IdResolver.begin(Name),
609 IEnd = IdResolver.end();
611 // First we lookup local scope.
612 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
613 // ...During unqualified name lookup (3.4.1), the names appear as if
614 // they were declared in the nearest enclosing namespace which contains
615 // both the using-directive and the nominated namespace.
616 // [Note: in this context, "contains" means "contains directly or
620 // namespace A { int i; }
624 // using namespace A;
625 // ++i; // finds local 'i', A::i appears at global scope
629 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
630 // Check whether the IdResolver has anything in this scope.
632 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) {
633 if (R.isAcceptableDecl(*I)) {
643 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) {
644 DeclContext *OuterCtx = findOuterContext(S);
645 for (; Ctx && Ctx->getPrimaryContext() != OuterCtx;
646 Ctx = Ctx->getLookupParent()) {
647 // We do not directly look into function or method contexts
648 // (since all local variables are found via the identifier
649 // changes) or in transparent contexts (since those entities
650 // will be found in the nearest enclosing non-transparent
652 if (Ctx->isFunctionOrMethod() || Ctx->isTransparentContext())
655 // Perform qualified name lookup into this context.
656 // FIXME: In some cases, we know that every name that could be found by
657 // this qualified name lookup will also be on the identifier chain. For
658 // example, inside a class without any base classes, we never need to
659 // perform qualified lookup because all of the members are on top of the
661 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
667 // Stop if we ran out of scopes.
668 // FIXME: This really, really shouldn't be happening.
669 if (!S) return false;
671 // Collect UsingDirectiveDecls in all scopes, and recursively all
672 // nominated namespaces by those using-directives.
674 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
675 // don't build it for each lookup!
677 UnqualUsingDirectiveSet UDirs;
678 UDirs.visitScopeChain(Initial, S);
681 // Lookup namespace scope, and global scope.
682 // Unqualified name lookup in C++ requires looking into scopes
683 // that aren't strictly lexical, and therefore we walk through the
684 // context as well as walking through the scopes.
686 for (; S; S = S->getParent()) {
687 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity());
688 if (Ctx && Ctx->isTransparentContext())
691 // Check whether the IdResolver has anything in this scope.
693 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) {
694 if (R.isAcceptableDecl(*I)) {
695 // We found something. Look for anything else in our scope
696 // with this same name and in an acceptable identifier
697 // namespace, so that we can construct an overload set if we
705 assert(Ctx->isFileContext() &&
706 "We should have been looking only at file context here already.");
708 // Look into context considering using-directives.
709 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
718 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
725 /// @brief Perform unqualified name lookup starting from a given
728 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
729 /// used to find names within the current scope. For example, 'x' in
733 /// return x; // unqualified name look finds 'x' in the global scope
737 /// Different lookup criteria can find different names. For example, a
738 /// particular scope can have both a struct and a function of the same
739 /// name, and each can be found by certain lookup criteria. For more
740 /// information about lookup criteria, see the documentation for the
741 /// class LookupCriteria.
743 /// @param S The scope from which unqualified name lookup will
744 /// begin. If the lookup criteria permits, name lookup may also search
745 /// in the parent scopes.
747 /// @param Name The name of the entity that we are searching for.
749 /// @param Loc If provided, the source location where we're performing
750 /// name lookup. At present, this is only used to produce diagnostics when
751 /// C library functions (like "malloc") are implicitly declared.
753 /// @returns The result of name lookup, which includes zero or more
754 /// declarations and possibly additional information used to diagnose
756 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
757 DeclarationName Name = R.getLookupName();
758 if (!Name) return false;
760 LookupNameKind NameKind = R.getLookupKind();
762 if (!getLangOptions().CPlusPlus) {
763 // Unqualified name lookup in C/Objective-C is purely lexical, so
764 // search in the declarations attached to the name.
766 if (NameKind == Sema::LookupRedeclarationWithLinkage) {
767 // Find the nearest non-transparent declaration scope.
768 while (!(S->getFlags() & Scope::DeclScope) ||
770 static_cast<DeclContext *>(S->getEntity())
771 ->isTransparentContext()))
775 unsigned IDNS = R.getIdentifierNamespace();
777 // Scan up the scope chain looking for a decl that matches this
778 // identifier that is in the appropriate namespace. This search
779 // should not take long, as shadowing of names is uncommon, and
780 // deep shadowing is extremely uncommon.
781 bool LeftStartingScope = false;
783 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
784 IEnd = IdResolver.end();
786 if ((*I)->isInIdentifierNamespace(IDNS)) {
787 if (NameKind == LookupRedeclarationWithLinkage) {
788 // Determine whether this (or a previous) declaration is
790 if (!LeftStartingScope && !S->isDeclScope(DeclPtrTy::make(*I)))
791 LeftStartingScope = true;
793 // If we found something outside of our starting scope that
794 // does not have linkage, skip it.
795 if (LeftStartingScope && !((*I)->hasLinkage()))
801 if ((*I)->getAttr<OverloadableAttr>()) {
802 // If this declaration has the "overloadable" attribute, we
803 // might have a set of overloaded functions.
805 // Figure out what scope the identifier is in.
806 while (!(S->getFlags() & Scope::DeclScope) ||
807 !S->isDeclScope(DeclPtrTy::make(*I)))
810 // Find the last declaration in this scope (with the same
812 IdentifierResolver::iterator LastI = I;
813 for (++LastI; LastI != IEnd; ++LastI) {
814 if (!S->isDeclScope(DeclPtrTy::make(*LastI)))
825 // Perform C++ unqualified name lookup.
826 if (CppLookupName(R, S))
830 // If we didn't find a use of this identifier, and if the identifier
831 // corresponds to a compiler builtin, create the decl object for the builtin
832 // now, injecting it into translation unit scope, and return it.
833 if (AllowBuiltinCreation)
834 return LookupBuiltin(*this, R);
839 /// @brief Perform qualified name lookup in the namespaces nominated by
840 /// using directives by the given context.
842 /// C++98 [namespace.qual]p2:
843 /// Given X::m (where X is a user-declared namespace), or given ::m
844 /// (where X is the global namespace), let S be the set of all
845 /// declarations of m in X and in the transitive closure of all
846 /// namespaces nominated by using-directives in X and its used
847 /// namespaces, except that using-directives are ignored in any
848 /// namespace, including X, directly containing one or more
849 /// declarations of m. No namespace is searched more than once in
850 /// the lookup of a name. If S is the empty set, the program is
851 /// ill-formed. Otherwise, if S has exactly one member, or if the
852 /// context of the reference is a using-declaration
853 /// (namespace.udecl), S is the required set of declarations of
854 /// m. Otherwise if the use of m is not one that allows a unique
855 /// declaration to be chosen from S, the program is ill-formed.
856 /// C++98 [namespace.qual]p5:
857 /// During the lookup of a qualified namespace member name, if the
858 /// lookup finds more than one declaration of the member, and if one
859 /// declaration introduces a class name or enumeration name and the
860 /// other declarations either introduce the same object, the same
861 /// enumerator or a set of functions, the non-type name hides the
862 /// class or enumeration name if and only if the declarations are
863 /// from the same namespace; otherwise (the declarations are from
864 /// different namespaces), the program is ill-formed.
865 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
866 DeclContext *StartDC) {
867 assert(StartDC->isFileContext() && "start context is not a file context");
869 DeclContext::udir_iterator I = StartDC->using_directives_begin();
870 DeclContext::udir_iterator E = StartDC->using_directives_end();
872 if (I == E) return false;
874 // We have at least added all these contexts to the queue.
875 llvm::DenseSet<DeclContext*> Visited;
876 Visited.insert(StartDC);
878 // We have not yet looked into these namespaces, much less added
879 // their "using-children" to the queue.
880 llvm::SmallVector<NamespaceDecl*, 8> Queue;
882 // We have already looked into the initial namespace; seed the queue
883 // with its using-children.
884 for (; I != E; ++I) {
885 NamespaceDecl *ND = (*I)->getNominatedNamespace()->getOriginalNamespace();
886 if (Visited.insert(ND).second)
890 // The easiest way to implement the restriction in [namespace.qual]p5
891 // is to check whether any of the individual results found a tag
892 // and, if so, to declare an ambiguity if the final result is not
894 bool FoundTag = false;
895 bool FoundNonTag = false;
897 LookupResult LocalR(LookupResult::Temporary, R);
900 while (!Queue.empty()) {
901 NamespaceDecl *ND = Queue.back();
904 // We go through some convolutions here to avoid copying results
905 // between LookupResults.
906 bool UseLocal = !R.empty();
907 LookupResult &DirectR = UseLocal ? LocalR : R;
908 bool FoundDirect = LookupDirect(S, DirectR, ND);
911 // First do any local hiding.
912 DirectR.resolveKind();
914 // If the local result is a tag, remember that.
915 if (DirectR.isSingleTagDecl())
920 // Append the local results to the total results if necessary.
922 R.addAllDecls(LocalR);
927 // If we find names in this namespace, ignore its using directives.
933 for (llvm::tie(I,E) = ND->getUsingDirectives(); I != E; ++I) {
934 NamespaceDecl *Nom = (*I)->getNominatedNamespace();
935 if (Visited.insert(Nom).second)
936 Queue.push_back(Nom);
941 if (FoundTag && FoundNonTag)
942 R.setAmbiguousQualifiedTagHiding();
950 /// \brief Perform qualified name lookup into a given context.
952 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
953 /// names when the context of those names is explicit specified, e.g.,
954 /// "std::vector" or "x->member", or as part of unqualified name lookup.
956 /// Different lookup criteria can find different names. For example, a
957 /// particular scope can have both a struct and a function of the same
958 /// name, and each can be found by certain lookup criteria. For more
959 /// information about lookup criteria, see the documentation for the
960 /// class LookupCriteria.
962 /// \param R captures both the lookup criteria and any lookup results found.
964 /// \param LookupCtx The context in which qualified name lookup will
965 /// search. If the lookup criteria permits, name lookup may also search
966 /// in the parent contexts or (for C++ classes) base classes.
968 /// \param InUnqualifiedLookup true if this is qualified name lookup that
969 /// occurs as part of unqualified name lookup.
971 /// \returns true if lookup succeeded, false if it failed.
972 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
973 bool InUnqualifiedLookup) {
974 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
976 if (!R.getLookupName())
979 // Make sure that the declaration context is complete.
980 assert((!isa<TagDecl>(LookupCtx) ||
981 LookupCtx->isDependentContext() ||
982 cast<TagDecl>(LookupCtx)->isDefinition() ||
983 Context.getTypeDeclType(cast<TagDecl>(LookupCtx))->getAs<TagType>()
984 ->isBeingDefined()) &&
985 "Declaration context must already be complete!");
987 // Perform qualified name lookup into the LookupCtx.
988 if (LookupDirect(*this, R, LookupCtx)) {
990 if (isa<CXXRecordDecl>(LookupCtx))
991 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
995 // Don't descend into implied contexts for redeclarations.
996 // C++98 [namespace.qual]p6:
997 // In a declaration for a namespace member in which the
998 // declarator-id is a qualified-id, given that the qualified-id
999 // for the namespace member has the form
1000 // nested-name-specifier unqualified-id
1001 // the unqualified-id shall name a member of the namespace
1002 // designated by the nested-name-specifier.
1003 // See also [class.mfct]p5 and [class.static.data]p2.
1004 if (R.isForRedeclaration())
1007 // If this is a namespace, look it up in the implied namespaces.
1008 if (LookupCtx->isFileContext())
1009 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
1011 // If this isn't a C++ class, we aren't allowed to look into base
1012 // classes, we're done.
1013 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
1017 // If we're performing qualified name lookup into a dependent class,
1018 // then we are actually looking into a current instantiation. If we have any
1019 // dependent base classes, then we either have to delay lookup until
1020 // template instantiation time (at which point all bases will be available)
1021 // or we have to fail.
1022 if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
1023 LookupRec->hasAnyDependentBases()) {
1024 R.setNotFoundInCurrentInstantiation();
1028 // Perform lookup into our base classes.
1030 Paths.setOrigin(LookupRec);
1032 // Look for this member in our base classes
1033 CXXRecordDecl::BaseMatchesCallback *BaseCallback = 0;
1034 switch (R.getLookupKind()) {
1035 case LookupOrdinaryName:
1036 case LookupMemberName:
1037 case LookupRedeclarationWithLinkage:
1038 BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
1042 BaseCallback = &CXXRecordDecl::FindTagMember;
1045 case LookupUsingDeclName:
1046 // This lookup is for redeclarations only.
1048 case LookupOperatorName:
1049 case LookupNamespaceName:
1050 case LookupObjCProtocolName:
1051 case LookupObjCImplementationName:
1052 // These lookups will never find a member in a C++ class (or base class).
1055 case LookupNestedNameSpecifierName:
1056 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember;
1060 if (!LookupRec->lookupInBases(BaseCallback,
1061 R.getLookupName().getAsOpaquePtr(), Paths))
1064 R.setNamingClass(LookupRec);
1066 // C++ [class.member.lookup]p2:
1067 // [...] If the resulting set of declarations are not all from
1068 // sub-objects of the same type, or the set has a nonstatic member
1069 // and includes members from distinct sub-objects, there is an
1070 // ambiguity and the program is ill-formed. Otherwise that set is
1071 // the result of the lookup.
1072 // FIXME: support using declarations!
1073 QualType SubobjectType;
1074 int SubobjectNumber = 0;
1075 AccessSpecifier SubobjectAccess = AS_private;
1076 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
1077 Path != PathEnd; ++Path) {
1078 const CXXBasePathElement &PathElement = Path->back();
1080 // Pick the best (i.e. most permissive i.e. numerically lowest) access
1081 // across all paths.
1082 SubobjectAccess = std::min(SubobjectAccess, Path->Access);
1084 // Determine whether we're looking at a distinct sub-object or not.
1085 if (SubobjectType.isNull()) {
1086 // This is the first subobject we've looked at. Record its type.
1087 SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
1088 SubobjectNumber = PathElement.SubobjectNumber;
1089 } else if (SubobjectType
1090 != Context.getCanonicalType(PathElement.Base->getType())) {
1091 // We found members of the given name in two subobjects of
1092 // different types. This lookup is ambiguous.
1093 R.setAmbiguousBaseSubobjectTypes(Paths);
1095 } else if (SubobjectNumber != PathElement.SubobjectNumber) {
1096 // We have a different subobject of the same type.
1098 // C++ [class.member.lookup]p5:
1099 // A static member, a nested type or an enumerator defined in
1100 // a base class T can unambiguously be found even if an object
1101 // has more than one base class subobject of type T.
1102 Decl *FirstDecl = *Path->Decls.first;
1103 if (isa<VarDecl>(FirstDecl) ||
1104 isa<TypeDecl>(FirstDecl) ||
1105 isa<EnumConstantDecl>(FirstDecl))
1108 if (isa<CXXMethodDecl>(FirstDecl)) {
1109 // Determine whether all of the methods are static.
1110 bool AllMethodsAreStatic = true;
1111 for (DeclContext::lookup_iterator Func = Path->Decls.first;
1112 Func != Path->Decls.second; ++Func) {
1113 if (!isa<CXXMethodDecl>(*Func)) {
1114 assert(isa<TagDecl>(*Func) && "Non-function must be a tag decl");
1118 if (!cast<CXXMethodDecl>(*Func)->isStatic()) {
1119 AllMethodsAreStatic = false;
1124 if (AllMethodsAreStatic)
1128 // We have found a nonstatic member name in multiple, distinct
1129 // subobjects. Name lookup is ambiguous.
1130 R.setAmbiguousBaseSubobjects(Paths);
1135 // Lookup in a base class succeeded; return these results.
1137 DeclContext::lookup_iterator I, E;
1138 for (llvm::tie(I,E) = Paths.front().Decls; I != E; ++I) {
1140 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
1148 /// @brief Performs name lookup for a name that was parsed in the
1149 /// source code, and may contain a C++ scope specifier.
1151 /// This routine is a convenience routine meant to be called from
1152 /// contexts that receive a name and an optional C++ scope specifier
1153 /// (e.g., "N::M::x"). It will then perform either qualified or
1154 /// unqualified name lookup (with LookupQualifiedName or LookupName,
1155 /// respectively) on the given name and return those results.
1157 /// @param S The scope from which unqualified name lookup will
1160 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
1162 /// @param Name The name of the entity that name lookup will
1165 /// @param Loc If provided, the source location where we're performing
1166 /// name lookup. At present, this is only used to produce diagnostics when
1167 /// C library functions (like "malloc") are implicitly declared.
1169 /// @param EnteringContext Indicates whether we are going to enter the
1170 /// context of the scope-specifier SS (if present).
1172 /// @returns True if any decls were found (but possibly ambiguous)
1173 bool Sema::LookupParsedName(LookupResult &R, Scope *S, const CXXScopeSpec *SS,
1174 bool AllowBuiltinCreation, bool EnteringContext) {
1175 if (SS && SS->isInvalid()) {
1176 // When the scope specifier is invalid, don't even look for
1181 if (SS && SS->isSet()) {
1182 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
1183 // We have resolved the scope specifier to a particular declaration
1184 // contex, and will perform name lookup in that context.
1185 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS))
1188 R.setContextRange(SS->getRange());
1190 return LookupQualifiedName(R, DC);
1193 // We could not resolve the scope specified to a specific declaration
1194 // context, which means that SS refers to an unknown specialization.
1195 // Name lookup can't find anything in this case.
1199 // Perform unqualified name lookup starting in the given scope.
1200 return LookupName(R, S, AllowBuiltinCreation);
1204 /// @brief Produce a diagnostic describing the ambiguity that resulted
1205 /// from name lookup.
1207 /// @param Result The ambiguous name lookup result.
1209 /// @param Name The name of the entity that name lookup was
1212 /// @param NameLoc The location of the name within the source code.
1214 /// @param LookupRange A source range that provides more
1215 /// source-location information concerning the lookup itself. For
1216 /// example, this range might highlight a nested-name-specifier that
1217 /// precedes the name.
1220 bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
1221 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
1223 DeclarationName Name = Result.getLookupName();
1224 SourceLocation NameLoc = Result.getNameLoc();
1225 SourceRange LookupRange = Result.getContextRange();
1227 switch (Result.getAmbiguityKind()) {
1228 case LookupResult::AmbiguousBaseSubobjects: {
1229 CXXBasePaths *Paths = Result.getBasePaths();
1230 QualType SubobjectType = Paths->front().back().Base->getType();
1231 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
1232 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
1235 DeclContext::lookup_iterator Found = Paths->front().Decls.first;
1236 while (isa<CXXMethodDecl>(*Found) &&
1237 cast<CXXMethodDecl>(*Found)->isStatic())
1240 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
1245 case LookupResult::AmbiguousBaseSubobjectTypes: {
1246 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
1247 << Name << LookupRange;
1249 CXXBasePaths *Paths = Result.getBasePaths();
1250 std::set<Decl *> DeclsPrinted;
1251 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
1252 PathEnd = Paths->end();
1253 Path != PathEnd; ++Path) {
1254 Decl *D = *Path->Decls.first;
1255 if (DeclsPrinted.insert(D).second)
1256 Diag(D->getLocation(), diag::note_ambiguous_member_found);
1262 case LookupResult::AmbiguousTagHiding: {
1263 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
1265 llvm::SmallPtrSet<NamedDecl*,8> TagDecls;
1267 LookupResult::iterator DI, DE = Result.end();
1268 for (DI = Result.begin(); DI != DE; ++DI)
1269 if (TagDecl *TD = dyn_cast<TagDecl>(*DI)) {
1270 TagDecls.insert(TD);
1271 Diag(TD->getLocation(), diag::note_hidden_tag);
1274 for (DI = Result.begin(); DI != DE; ++DI)
1275 if (!isa<TagDecl>(*DI))
1276 Diag((*DI)->getLocation(), diag::note_hiding_object);
1278 // For recovery purposes, go ahead and implement the hiding.
1279 LookupResult::Filter F = Result.makeFilter();
1280 while (F.hasNext()) {
1281 if (TagDecls.count(F.next()))
1289 case LookupResult::AmbiguousReference: {
1290 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
1292 LookupResult::iterator DI = Result.begin(), DE = Result.end();
1293 for (; DI != DE; ++DI)
1294 Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI;
1300 llvm_unreachable("unknown ambiguity kind");
1305 addAssociatedClassesAndNamespaces(QualType T,
1306 ASTContext &Context,
1307 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1308 Sema::AssociatedClassSet &AssociatedClasses);
1310 static void CollectNamespace(Sema::AssociatedNamespaceSet &Namespaces,
1312 if (Ctx->isFileContext())
1313 Namespaces.insert(Ctx);
1316 // \brief Add the associated classes and namespaces for argument-dependent
1317 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2).
1319 addAssociatedClassesAndNamespaces(const TemplateArgument &Arg,
1320 ASTContext &Context,
1321 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1322 Sema::AssociatedClassSet &AssociatedClasses) {
1323 // C++ [basic.lookup.koenig]p2, last bullet:
1325 switch (Arg.getKind()) {
1326 case TemplateArgument::Null:
1329 case TemplateArgument::Type:
1330 // [...] the namespaces and classes associated with the types of the
1331 // template arguments provided for template type parameters (excluding
1332 // template template parameters)
1333 addAssociatedClassesAndNamespaces(Arg.getAsType(), Context,
1334 AssociatedNamespaces,
1338 case TemplateArgument::Template: {
1339 // [...] the namespaces in which any template template arguments are
1340 // defined; and the classes in which any member templates used as
1341 // template template arguments are defined.
1342 TemplateName Template = Arg.getAsTemplate();
1343 if (ClassTemplateDecl *ClassTemplate
1344 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
1345 DeclContext *Ctx = ClassTemplate->getDeclContext();
1346 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1347 AssociatedClasses.insert(EnclosingClass);
1348 // Add the associated namespace for this class.
1349 while (Ctx->isRecord())
1350 Ctx = Ctx->getParent();
1351 CollectNamespace(AssociatedNamespaces, Ctx);
1356 case TemplateArgument::Declaration:
1357 case TemplateArgument::Integral:
1358 case TemplateArgument::Expression:
1359 // [Note: non-type template arguments do not contribute to the set of
1360 // associated namespaces. ]
1363 case TemplateArgument::Pack:
1364 for (TemplateArgument::pack_iterator P = Arg.pack_begin(),
1365 PEnd = Arg.pack_end();
1367 addAssociatedClassesAndNamespaces(*P, Context,
1368 AssociatedNamespaces,
1374 // \brief Add the associated classes and namespaces for
1375 // argument-dependent lookup with an argument of class type
1376 // (C++ [basic.lookup.koenig]p2).
1378 addAssociatedClassesAndNamespaces(CXXRecordDecl *Class,
1379 ASTContext &Context,
1380 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1381 Sema::AssociatedClassSet &AssociatedClasses) {
1382 // C++ [basic.lookup.koenig]p2:
1384 // -- If T is a class type (including unions), its associated
1385 // classes are: the class itself; the class of which it is a
1386 // member, if any; and its direct and indirect base
1387 // classes. Its associated namespaces are the namespaces in
1388 // which its associated classes are defined.
1390 // Add the class of which it is a member, if any.
1391 DeclContext *Ctx = Class->getDeclContext();
1392 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1393 AssociatedClasses.insert(EnclosingClass);
1394 // Add the associated namespace for this class.
1395 while (Ctx->isRecord())
1396 Ctx = Ctx->getParent();
1397 CollectNamespace(AssociatedNamespaces, Ctx);
1399 // Add the class itself. If we've already seen this class, we don't
1400 // need to visit base classes.
1401 if (!AssociatedClasses.insert(Class))
1404 // -- If T is a template-id, its associated namespaces and classes are
1405 // the namespace in which the template is defined; for member
1406 // templates, the member template’s class; the namespaces and classes
1407 // associated with the types of the template arguments provided for
1408 // template type parameters (excluding template template parameters); the
1409 // namespaces in which any template template arguments are defined; and
1410 // the classes in which any member templates used as template template
1411 // arguments are defined. [Note: non-type template arguments do not
1412 // contribute to the set of associated namespaces. ]
1413 if (ClassTemplateSpecializationDecl *Spec
1414 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
1415 DeclContext *Ctx = Spec->getSpecializedTemplate()->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 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
1424 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
1425 addAssociatedClassesAndNamespaces(TemplateArgs[I], Context,
1426 AssociatedNamespaces,
1430 // Only recurse into base classes for complete types.
1431 if (!Class->hasDefinition()) {
1432 // FIXME: we might need to instantiate templates here
1436 // Add direct and indirect base classes along with their associated
1438 llvm::SmallVector<CXXRecordDecl *, 32> Bases;
1439 Bases.push_back(Class);
1440 while (!Bases.empty()) {
1441 // Pop this class off the stack.
1442 Class = Bases.back();
1445 // Visit the base classes.
1446 for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(),
1447 BaseEnd = Class->bases_end();
1448 Base != BaseEnd; ++Base) {
1449 const RecordType *BaseType = Base->getType()->getAs<RecordType>();
1450 // In dependent contexts, we do ADL twice, and the first time around,
1451 // the base type might be a dependent TemplateSpecializationType, or a
1452 // TemplateTypeParmType. If that happens, simply ignore it.
1453 // FIXME: If we want to support export, we probably need to add the
1454 // namespace of the template in a TemplateSpecializationType, or even
1455 // the classes and namespaces of known non-dependent arguments.
1458 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
1459 if (AssociatedClasses.insert(BaseDecl)) {
1460 // Find the associated namespace for this base class.
1461 DeclContext *BaseCtx = BaseDecl->getDeclContext();
1462 while (BaseCtx->isRecord())
1463 BaseCtx = BaseCtx->getParent();
1464 CollectNamespace(AssociatedNamespaces, BaseCtx);
1466 // Make sure we visit the bases of this base class.
1467 if (BaseDecl->bases_begin() != BaseDecl->bases_end())
1468 Bases.push_back(BaseDecl);
1474 // \brief Add the associated classes and namespaces for
1475 // argument-dependent lookup with an argument of type T
1476 // (C++ [basic.lookup.koenig]p2).
1478 addAssociatedClassesAndNamespaces(QualType T,
1479 ASTContext &Context,
1480 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1481 Sema::AssociatedClassSet &AssociatedClasses) {
1482 // C++ [basic.lookup.koenig]p2:
1484 // For each argument type T in the function call, there is a set
1485 // of zero or more associated namespaces and a set of zero or more
1486 // associated classes to be considered. The sets of namespaces and
1487 // classes is determined entirely by the types of the function
1488 // arguments (and the namespace of any template template
1489 // argument). Typedef names and using-declarations used to specify
1490 // the types do not contribute to this set. The sets of namespaces
1491 // and classes are determined in the following way:
1492 T = Context.getCanonicalType(T).getUnqualifiedType();
1494 // -- If T is a pointer to U or an array of U, its associated
1495 // namespaces and classes are those associated with U.
1497 // We handle this by unwrapping pointer and array types immediately,
1498 // to avoid unnecessary recursion.
1500 if (const PointerType *Ptr = T->getAs<PointerType>())
1501 T = Ptr->getPointeeType();
1502 else if (const ArrayType *Ptr = Context.getAsArrayType(T))
1503 T = Ptr->getElementType();
1508 // -- If T is a fundamental type, its associated sets of
1509 // namespaces and classes are both empty.
1510 if (T->getAs<BuiltinType>())
1513 // -- If T is a class type (including unions), its associated
1514 // classes are: the class itself; the class of which it is a
1515 // member, if any; and its direct and indirect base
1516 // classes. Its associated namespaces are the namespaces in
1517 // which its associated classes are defined.
1518 if (const RecordType *ClassType = T->getAs<RecordType>())
1519 if (CXXRecordDecl *ClassDecl
1520 = dyn_cast<CXXRecordDecl>(ClassType->getDecl())) {
1521 addAssociatedClassesAndNamespaces(ClassDecl, Context,
1522 AssociatedNamespaces,
1527 // -- If T is an enumeration type, its associated namespace is
1528 // the namespace in which it is defined. If it is class
1529 // member, its associated class is the member’s class; else
1530 // it has no associated class.
1531 if (const EnumType *EnumT = T->getAs<EnumType>()) {
1532 EnumDecl *Enum = EnumT->getDecl();
1534 DeclContext *Ctx = Enum->getDeclContext();
1535 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1536 AssociatedClasses.insert(EnclosingClass);
1538 // Add the associated namespace for this class.
1539 while (Ctx->isRecord())
1540 Ctx = Ctx->getParent();
1541 CollectNamespace(AssociatedNamespaces, Ctx);
1546 // -- If T is a function type, its associated namespaces and
1547 // classes are those associated with the function parameter
1548 // types and those associated with the return type.
1549 if (const FunctionType *FnType = T->getAs<FunctionType>()) {
1551 addAssociatedClassesAndNamespaces(FnType->getResultType(),
1553 AssociatedNamespaces, AssociatedClasses);
1555 const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FnType);
1560 for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(),
1561 ArgEnd = Proto->arg_type_end();
1562 Arg != ArgEnd; ++Arg)
1563 addAssociatedClassesAndNamespaces(*Arg, Context,
1564 AssociatedNamespaces, AssociatedClasses);
1569 // -- If T is a pointer to a member function of a class X, its
1570 // associated namespaces and classes are those associated
1571 // with the function parameter types and return type,
1572 // together with those associated with X.
1574 // -- If T is a pointer to a data member of class X, its
1575 // associated namespaces and classes are those associated
1576 // with the member type together with those associated with
1578 if (const MemberPointerType *MemberPtr = T->getAs<MemberPointerType>()) {
1579 // Handle the type that the pointer to member points to.
1580 addAssociatedClassesAndNamespaces(MemberPtr->getPointeeType(),
1582 AssociatedNamespaces,
1585 // Handle the class type into which this points.
1586 if (const RecordType *Class = MemberPtr->getClass()->getAs<RecordType>())
1587 addAssociatedClassesAndNamespaces(cast<CXXRecordDecl>(Class->getDecl()),
1589 AssociatedNamespaces,
1595 // FIXME: What about block pointers?
1596 // FIXME: What about Objective-C message sends?
1599 /// \brief Find the associated classes and namespaces for
1600 /// argument-dependent lookup for a call with the given set of
1603 /// This routine computes the sets of associated classes and associated
1604 /// namespaces searched by argument-dependent lookup
1605 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
1607 Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs,
1608 AssociatedNamespaceSet &AssociatedNamespaces,
1609 AssociatedClassSet &AssociatedClasses) {
1610 AssociatedNamespaces.clear();
1611 AssociatedClasses.clear();
1613 // C++ [basic.lookup.koenig]p2:
1614 // For each argument type T in the function call, there is a set
1615 // of zero or more associated namespaces and a set of zero or more
1616 // associated classes to be considered. The sets of namespaces and
1617 // classes is determined entirely by the types of the function
1618 // arguments (and the namespace of any template template
1620 for (unsigned ArgIdx = 0; ArgIdx != NumArgs; ++ArgIdx) {
1621 Expr *Arg = Args[ArgIdx];
1623 if (Arg->getType() != Context.OverloadTy) {
1624 addAssociatedClassesAndNamespaces(Arg->getType(), Context,
1625 AssociatedNamespaces,
1630 // [...] In addition, if the argument is the name or address of a
1631 // set of overloaded functions and/or function templates, its
1632 // associated classes and namespaces are the union of those
1633 // associated with each of the members of the set: the namespace
1634 // in which the function or function template is defined and the
1635 // classes and namespaces associated with its (non-dependent)
1636 // parameter types and return type.
1637 Arg = Arg->IgnoreParens();
1638 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg))
1639 if (unaryOp->getOpcode() == UnaryOperator::AddrOf)
1640 Arg = unaryOp->getSubExpr();
1642 // TODO: avoid the copies. This should be easy when the cases
1643 // share a storage implementation.
1644 llvm::SmallVector<NamedDecl*, 8> Functions;
1646 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg))
1647 Functions.append(ULE->decls_begin(), ULE->decls_end());
1651 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Functions.begin(),
1652 E = Functions.end(); I != E; ++I) {
1653 // Look through any using declarations to find the underlying function.
1654 NamedDecl *Fn = (*I)->getUnderlyingDecl();
1656 FunctionDecl *FDecl = dyn_cast<FunctionDecl>(Fn);
1658 FDecl = cast<FunctionTemplateDecl>(Fn)->getTemplatedDecl();
1660 // Add the classes and namespaces associated with the parameter
1661 // types and return type of this function.
1662 addAssociatedClassesAndNamespaces(FDecl->getType(), Context,
1663 AssociatedNamespaces,
1669 /// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
1670 /// an acceptable non-member overloaded operator for a call whose
1671 /// arguments have types T1 (and, if non-empty, T2). This routine
1672 /// implements the check in C++ [over.match.oper]p3b2 concerning
1673 /// enumeration types.
1675 IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn,
1676 QualType T1, QualType T2,
1677 ASTContext &Context) {
1678 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
1681 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
1684 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
1685 if (Proto->getNumArgs() < 1)
1688 if (T1->isEnumeralType()) {
1689 QualType ArgType = Proto->getArgType(0).getNonReferenceType();
1690 if (Context.hasSameUnqualifiedType(T1, ArgType))
1694 if (Proto->getNumArgs() < 2)
1697 if (!T2.isNull() && T2->isEnumeralType()) {
1698 QualType ArgType = Proto->getArgType(1).getNonReferenceType();
1699 if (Context.hasSameUnqualifiedType(T2, ArgType))
1706 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
1707 LookupNameKind NameKind,
1708 RedeclarationKind Redecl) {
1709 LookupResult R(*this, Name, SourceLocation(), NameKind, Redecl);
1711 return R.getAsSingle<NamedDecl>();
1714 /// \brief Find the protocol with the given name, if any.
1715 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II) {
1716 Decl *D = LookupSingleName(TUScope, II, LookupObjCProtocolName);
1717 return cast_or_null<ObjCProtocolDecl>(D);
1720 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
1721 QualType T1, QualType T2,
1722 UnresolvedSetImpl &Functions) {
1723 // C++ [over.match.oper]p3:
1724 // -- The set of non-member candidates is the result of the
1725 // unqualified lookup of operator@ in the context of the
1726 // expression according to the usual rules for name lookup in
1727 // unqualified function calls (3.4.2) except that all member
1728 // functions are ignored. However, if no operand has a class
1729 // type, only those non-member functions in the lookup set
1730 // that have a first parameter of type T1 or "reference to
1731 // (possibly cv-qualified) T1", when T1 is an enumeration
1732 // type, or (if there is a right operand) a second parameter
1733 // of type T2 or "reference to (possibly cv-qualified) T2",
1734 // when T2 is an enumeration type, are candidate functions.
1735 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
1736 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
1737 LookupName(Operators, S);
1739 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
1741 if (Operators.empty())
1744 for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end();
1745 Op != OpEnd; ++Op) {
1746 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Op)) {
1747 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context))
1748 Functions.addDecl(FD, Op.getAccess()); // FIXME: canonical FD
1749 } else if (FunctionTemplateDecl *FunTmpl
1750 = dyn_cast<FunctionTemplateDecl>(*Op)) {
1751 // FIXME: friend operators?
1752 // FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate,
1754 if (!FunTmpl->getDeclContext()->isRecord())
1755 Functions.addDecl(FunTmpl, Op.getAccess());
1760 void ADLResult::insert(NamedDecl *New) {
1761 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
1763 // If we haven't yet seen a decl for this key, or the last decl
1764 // was exactly this one, we're done.
1765 if (Old == 0 || Old == New) {
1770 // Otherwise, decide which is a more recent redeclaration.
1771 FunctionDecl *OldFD, *NewFD;
1772 if (isa<FunctionTemplateDecl>(New)) {
1773 OldFD = cast<FunctionTemplateDecl>(Old)->getTemplatedDecl();
1774 NewFD = cast<FunctionTemplateDecl>(New)->getTemplatedDecl();
1776 OldFD = cast<FunctionDecl>(Old);
1777 NewFD = cast<FunctionDecl>(New);
1780 FunctionDecl *Cursor = NewFD;
1782 Cursor = Cursor->getPreviousDeclaration();
1784 // If we got to the end without finding OldFD, OldFD is the newer
1785 // declaration; leave things as they are.
1786 if (!Cursor) return;
1788 // If we do find OldFD, then NewFD is newer.
1789 if (Cursor == OldFD) break;
1791 // Otherwise, keep looking.
1797 void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator,
1798 Expr **Args, unsigned NumArgs,
1799 ADLResult &Result) {
1800 // Find all of the associated namespaces and classes based on the
1801 // arguments we have.
1802 AssociatedNamespaceSet AssociatedNamespaces;
1803 AssociatedClassSet AssociatedClasses;
1804 FindAssociatedClassesAndNamespaces(Args, NumArgs,
1805 AssociatedNamespaces,
1810 T1 = Args[0]->getType();
1812 T2 = Args[1]->getType();
1815 // C++ [basic.lookup.argdep]p3:
1816 // Let X be the lookup set produced by unqualified lookup (3.4.1)
1817 // and let Y be the lookup set produced by argument dependent
1818 // lookup (defined as follows). If X contains [...] then Y is
1819 // empty. Otherwise Y is the set of declarations found in the
1820 // namespaces associated with the argument types as described
1821 // below. The set of declarations found by the lookup of the name
1822 // is the union of X and Y.
1824 // Here, we compute Y and add its members to the overloaded
1826 for (AssociatedNamespaceSet::iterator NS = AssociatedNamespaces.begin(),
1827 NSEnd = AssociatedNamespaces.end();
1828 NS != NSEnd; ++NS) {
1829 // When considering an associated namespace, the lookup is the
1830 // same as the lookup performed when the associated namespace is
1831 // used as a qualifier (3.4.3.2) except that:
1833 // -- Any using-directives in the associated namespace are
1836 // -- Any namespace-scope friend functions declared in
1837 // associated classes are visible within their respective
1838 // namespaces even if they are not visible during an ordinary
1840 DeclContext::lookup_iterator I, E;
1841 for (llvm::tie(I, E) = (*NS)->lookup(Name); I != E; ++I) {
1843 // If the only declaration here is an ordinary friend, consider
1844 // it only if it was declared in an associated classes.
1845 if (D->getIdentifierNamespace() == Decl::IDNS_OrdinaryFriend) {
1846 DeclContext *LexDC = D->getLexicalDeclContext();
1847 if (!AssociatedClasses.count(cast<CXXRecordDecl>(LexDC)))
1851 if (isa<UsingShadowDecl>(D))
1852 D = cast<UsingShadowDecl>(D)->getTargetDecl();
1854 if (isa<FunctionDecl>(D)) {
1856 !IsAcceptableNonMemberOperatorCandidate(cast<FunctionDecl>(D),
1859 } else if (!isa<FunctionTemplateDecl>(D))
1867 //----------------------------------------------------------------------------
1868 // Search for all visible declarations.
1869 //----------------------------------------------------------------------------
1870 VisibleDeclConsumer::~VisibleDeclConsumer() { }
1874 class ShadowContextRAII;
1876 class VisibleDeclsRecord {
1878 /// \brief An entry in the shadow map, which is optimized to store a
1879 /// single declaration (the common case) but can also store a list
1880 /// of declarations.
1881 class ShadowMapEntry {
1882 typedef llvm::SmallVector<NamedDecl *, 4> DeclVector;
1884 /// \brief Contains either the solitary NamedDecl * or a vector
1885 /// of declarations.
1886 llvm::PointerUnion<NamedDecl *, DeclVector*> DeclOrVector;
1889 ShadowMapEntry() : DeclOrVector() { }
1891 void Add(NamedDecl *ND);
1895 typedef NamedDecl **iterator;
1901 /// \brief A mapping from declaration names to the declarations that have
1902 /// this name within a particular scope.
1903 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
1905 /// \brief A list of shadow maps, which is used to model name hiding.
1906 std::list<ShadowMap> ShadowMaps;
1908 /// \brief The declaration contexts we have already visited.
1909 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
1911 friend class ShadowContextRAII;
1914 /// \brief Determine whether we have already visited this context
1915 /// (and, if not, note that we are going to visit that context now).
1916 bool visitedContext(DeclContext *Ctx) {
1917 return !VisitedContexts.insert(Ctx);
1920 /// \brief Determine whether the given declaration is hidden in the
1923 /// \returns the declaration that hides the given declaration, or
1924 /// NULL if no such declaration exists.
1925 NamedDecl *checkHidden(NamedDecl *ND);
1927 /// \brief Add a declaration to the current shadow map.
1928 void add(NamedDecl *ND) { ShadowMaps.back()[ND->getDeclName()].Add(ND); }
1931 /// \brief RAII object that records when we've entered a shadow context.
1932 class ShadowContextRAII {
1933 VisibleDeclsRecord &Visible;
1935 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
1938 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
1939 Visible.ShadowMaps.push_back(ShadowMap());
1942 ~ShadowContextRAII() {
1943 for (ShadowMap::iterator E = Visible.ShadowMaps.back().begin(),
1944 EEnd = Visible.ShadowMaps.back().end();
1947 E->second.Destroy();
1949 Visible.ShadowMaps.pop_back();
1953 } // end anonymous namespace
1955 void VisibleDeclsRecord::ShadowMapEntry::Add(NamedDecl *ND) {
1956 if (DeclOrVector.isNull()) {
1957 // 0 - > 1 elements: just set the single element information.
1962 if (NamedDecl *PrevND = DeclOrVector.dyn_cast<NamedDecl *>()) {
1963 // 1 -> 2 elements: create the vector of results and push in the
1964 // existing declaration.
1965 DeclVector *Vec = new DeclVector;
1966 Vec->push_back(PrevND);
1970 // Add the new element to the end of the vector.
1971 DeclOrVector.get<DeclVector*>()->push_back(ND);
1974 void VisibleDeclsRecord::ShadowMapEntry::Destroy() {
1975 if (DeclVector *Vec = DeclOrVector.dyn_cast<DeclVector *>()) {
1977 DeclOrVector = ((NamedDecl *)0);
1981 VisibleDeclsRecord::ShadowMapEntry::iterator
1982 VisibleDeclsRecord::ShadowMapEntry::begin() {
1983 if (DeclOrVector.isNull())
1986 if (DeclOrVector.dyn_cast<NamedDecl *>())
1987 return &reinterpret_cast<NamedDecl*&>(DeclOrVector);
1989 return DeclOrVector.get<DeclVector *>()->begin();
1992 VisibleDeclsRecord::ShadowMapEntry::iterator
1993 VisibleDeclsRecord::ShadowMapEntry::end() {
1994 if (DeclOrVector.isNull())
1997 if (DeclOrVector.dyn_cast<NamedDecl *>())
1998 return &reinterpret_cast<NamedDecl*&>(DeclOrVector) + 1;
2000 return DeclOrVector.get<DeclVector *>()->end();
2003 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
2004 // Look through using declarations.
2005 ND = ND->getUnderlyingDecl();
2007 unsigned IDNS = ND->getIdentifierNamespace();
2008 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
2009 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
2010 SM != SMEnd; ++SM) {
2011 ShadowMap::iterator Pos = SM->find(ND->getDeclName());
2012 if (Pos == SM->end())
2015 for (ShadowMapEntry::iterator I = Pos->second.begin(),
2016 IEnd = Pos->second.end();
2018 // A tag declaration does not hide a non-tag declaration.
2019 if ((*I)->getIdentifierNamespace() == Decl::IDNS_Tag &&
2020 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
2021 Decl::IDNS_ObjCProtocol)))
2024 // Protocols are in distinct namespaces from everything else.
2025 if ((((*I)->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
2026 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
2027 (*I)->getIdentifierNamespace() != IDNS)
2030 // Functions and function templates in the same scope overload
2031 // rather than hide. FIXME: Look for hiding based on function
2033 if ((*I)->isFunctionOrFunctionTemplate() &&
2034 ND->isFunctionOrFunctionTemplate() &&
2035 SM == ShadowMaps.rbegin())
2038 // We've found a declaration that hides this one.
2046 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
2047 bool QualifiedNameLookup,
2049 VisibleDeclConsumer &Consumer,
2050 VisibleDeclsRecord &Visited) {
2054 // Make sure we don't visit the same context twice.
2055 if (Visited.visitedContext(Ctx->getPrimaryContext()))
2058 // Enumerate all of the results in this context.
2059 for (DeclContext *CurCtx = Ctx->getPrimaryContext(); CurCtx;
2060 CurCtx = CurCtx->getNextContext()) {
2061 for (DeclContext::decl_iterator D = CurCtx->decls_begin(),
2062 DEnd = CurCtx->decls_end();
2064 if (NamedDecl *ND = dyn_cast<NamedDecl>(*D))
2065 if (Result.isAcceptableDecl(ND)) {
2066 Consumer.FoundDecl(ND, Visited.checkHidden(ND), InBaseClass);
2070 // Visit transparent contexts inside this context.
2071 if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D)) {
2072 if (InnerCtx->isTransparentContext())
2073 LookupVisibleDecls(InnerCtx, Result, QualifiedNameLookup, InBaseClass,
2079 // Traverse using directives for qualified name lookup.
2080 if (QualifiedNameLookup) {
2081 ShadowContextRAII Shadow(Visited);
2082 DeclContext::udir_iterator I, E;
2083 for (llvm::tie(I, E) = Ctx->getUsingDirectives(); I != E; ++I) {
2084 LookupVisibleDecls((*I)->getNominatedNamespace(), Result,
2085 QualifiedNameLookup, InBaseClass, Consumer, Visited);
2089 // Traverse the contexts of inherited C++ classes.
2090 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
2091 if (!Record->hasDefinition())
2094 for (CXXRecordDecl::base_class_iterator B = Record->bases_begin(),
2095 BEnd = Record->bases_end();
2097 QualType BaseType = B->getType();
2099 // Don't look into dependent bases, because name lookup can't look
2101 if (BaseType->isDependentType())
2104 const RecordType *Record = BaseType->getAs<RecordType>();
2108 // FIXME: It would be nice to be able to determine whether referencing
2109 // a particular member would be ambiguous. For example, given
2111 // struct A { int member; };
2112 // struct B { int member; };
2113 // struct C : A, B { };
2115 // void f(C *c) { c->### }
2117 // accessing 'member' would result in an ambiguity. However, we
2118 // could be smart enough to qualify the member with the base
2127 // Find results in this base class (and its bases).
2128 ShadowContextRAII Shadow(Visited);
2129 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup,
2130 true, Consumer, Visited);
2134 // Traverse the contexts of Objective-C classes.
2135 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
2136 // Traverse categories.
2137 for (ObjCCategoryDecl *Category = IFace->getCategoryList();
2138 Category; Category = Category->getNextClassCategory()) {
2139 ShadowContextRAII Shadow(Visited);
2140 LookupVisibleDecls(Category, Result, QualifiedNameLookup, false,
2144 // Traverse protocols.
2145 for (ObjCInterfaceDecl::protocol_iterator I = IFace->protocol_begin(),
2146 E = IFace->protocol_end(); I != E; ++I) {
2147 ShadowContextRAII Shadow(Visited);
2148 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer,
2152 // Traverse the superclass.
2153 if (IFace->getSuperClass()) {
2154 ShadowContextRAII Shadow(Visited);
2155 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup,
2156 true, Consumer, Visited);
2158 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
2159 for (ObjCProtocolDecl::protocol_iterator I = Protocol->protocol_begin(),
2160 E = Protocol->protocol_end(); I != E; ++I) {
2161 ShadowContextRAII Shadow(Visited);
2162 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer,
2165 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
2166 for (ObjCCategoryDecl::protocol_iterator I = Category->protocol_begin(),
2167 E = Category->protocol_end(); I != E; ++I) {
2168 ShadowContextRAII Shadow(Visited);
2169 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer,
2175 static void LookupVisibleDecls(Scope *S, LookupResult &Result,
2176 UnqualUsingDirectiveSet &UDirs,
2177 VisibleDeclConsumer &Consumer,
2178 VisibleDeclsRecord &Visited) {
2182 if (!S->getEntity() || !S->getParent() ||
2183 ((DeclContext *)S->getEntity())->isFunctionOrMethod()) {
2184 // Walk through the declarations in this Scope.
2185 for (Scope::decl_iterator D = S->decl_begin(), DEnd = S->decl_end();
2187 if (NamedDecl *ND = dyn_cast<NamedDecl>((Decl *)((*D).get())))
2188 if (Result.isAcceptableDecl(ND)) {
2189 Consumer.FoundDecl(ND, Visited.checkHidden(ND), false);
2195 DeclContext *Entity = 0;
2196 if (S->getEntity()) {
2197 // Look into this scope's declaration context, along with any of its
2198 // parent lookup contexts (e.g., enclosing classes), up to the point
2199 // where we hit the context stored in the next outer scope.
2200 Entity = (DeclContext *)S->getEntity();
2201 DeclContext *OuterCtx = findOuterContext(S);
2203 for (DeclContext *Ctx = Entity; Ctx && Ctx->getPrimaryContext() != OuterCtx;
2204 Ctx = Ctx->getLookupParent()) {
2205 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
2206 if (Method->isInstanceMethod()) {
2207 // For instance methods, look for ivars in the method's interface.
2208 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
2209 Result.getNameLoc(), Sema::LookupMemberName);
2210 if (ObjCInterfaceDecl *IFace = Method->getClassInterface())
2211 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false,
2212 /*InBaseClass=*/false, Consumer, Visited);
2215 // We've already performed all of the name lookup that we need
2216 // to for Objective-C methods; the next context will be the
2221 if (Ctx->isFunctionOrMethod())
2224 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false,
2225 /*InBaseClass=*/false, Consumer, Visited);
2227 } else if (!S->getParent()) {
2228 // Look into the translation unit scope. We walk through the translation
2229 // unit's declaration context, because the Scope itself won't have all of
2230 // the declarations if we loaded a precompiled header.
2231 // FIXME: We would like the translation unit's Scope object to point to the
2232 // translation unit, so we don't need this special "if" branch. However,
2233 // doing so would force the normal C++ name-lookup code to look into the
2234 // translation unit decl when the IdentifierInfo chains would suffice.
2235 // Once we fix that problem (which is part of a more general "don't look
2236 // in DeclContexts unless we have to" optimization), we can eliminate this.
2237 Entity = Result.getSema().Context.getTranslationUnitDecl();
2238 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false,
2239 /*InBaseClass=*/false, Consumer, Visited);
2243 // Lookup visible declarations in any namespaces found by using
2245 UnqualUsingDirectiveSet::const_iterator UI, UEnd;
2246 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(Entity);
2247 for (; UI != UEnd; ++UI)
2248 LookupVisibleDecls(const_cast<DeclContext *>(UI->getNominatedNamespace()),
2249 Result, /*QualifiedNameLookup=*/false,
2250 /*InBaseClass=*/false, Consumer, Visited);
2253 // Lookup names in the parent scope.
2254 ShadowContextRAII Shadow(Visited);
2255 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited);
2258 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
2259 VisibleDeclConsumer &Consumer) {
2260 // Determine the set of using directives available during
2261 // unqualified name lookup.
2263 UnqualUsingDirectiveSet UDirs;
2264 if (getLangOptions().CPlusPlus) {
2265 // Find the first namespace or translation-unit scope.
2266 while (S && !isNamespaceOrTranslationUnitScope(S))
2269 UDirs.visitScopeChain(Initial, S);
2273 // Look for visible declarations.
2274 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
2275 VisibleDeclsRecord Visited;
2276 ShadowContextRAII Shadow(Visited);
2277 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited);
2280 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
2281 VisibleDeclConsumer &Consumer) {
2282 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
2283 VisibleDeclsRecord Visited;
2284 ShadowContextRAII Shadow(Visited);
2285 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true,
2286 /*InBaseClass=*/false, Consumer, Visited);
2289 //----------------------------------------------------------------------------
2291 //----------------------------------------------------------------------------
2294 class TypoCorrectionConsumer : public VisibleDeclConsumer {
2295 /// \brief The name written that is a typo in the source.
2296 llvm::StringRef Typo;
2298 /// \brief The results found that have the smallest edit distance
2299 /// found (so far) with the typo name.
2300 llvm::SmallVector<NamedDecl *, 4> BestResults;
2302 /// \brief The best edit distance found so far.
2303 unsigned BestEditDistance;
2306 explicit TypoCorrectionConsumer(IdentifierInfo *Typo)
2307 : Typo(Typo->getName()) { }
2309 virtual void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, bool InBaseClass);
2311 typedef llvm::SmallVector<NamedDecl *, 4>::const_iterator iterator;
2312 iterator begin() const { return BestResults.begin(); }
2313 iterator end() const { return BestResults.end(); }
2314 bool empty() const { return BestResults.empty(); }
2316 unsigned getBestEditDistance() const { return BestEditDistance; }
2321 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
2323 // Don't consider hidden names for typo correction.
2327 // Only consider entities with identifiers for names, ignoring
2328 // special names (constructors, overloaded operators, selectors,
2330 IdentifierInfo *Name = ND->getIdentifier();
2334 // Compute the edit distance between the typo and the name of this
2335 // entity. If this edit distance is not worse than the best edit
2336 // distance we've seen so far, add it to the list of results.
2337 unsigned ED = Typo.edit_distance(Name->getName());
2338 if (!BestResults.empty()) {
2339 if (ED < BestEditDistance) {
2340 // This result is better than any we've seen before; clear out
2341 // the previous results.
2342 BestResults.clear();
2343 BestEditDistance = ED;
2344 } else if (ED > BestEditDistance) {
2345 // This result is worse than the best results we've seen so far;
2350 BestEditDistance = ED;
2352 BestResults.push_back(ND);
2355 /// \brief Try to "correct" a typo in the source code by finding
2356 /// visible declarations whose names are similar to the name that was
2357 /// present in the source code.
2359 /// \param Res the \c LookupResult structure that contains the name
2360 /// that was present in the source code along with the name-lookup
2361 /// criteria used to search for the name. On success, this structure
2362 /// will contain the results of name lookup.
2364 /// \param S the scope in which name lookup occurs.
2366 /// \param SS the nested-name-specifier that precedes the name we're
2367 /// looking for, if present.
2369 /// \param MemberContext if non-NULL, the context in which to look for
2370 /// a member access expression.
2372 /// \param EnteringContext whether we're entering the context described by
2373 /// the nested-name-specifier SS.
2375 /// \param OPT when non-NULL, the search for visible declarations will
2376 /// also walk the protocols in the qualified interfaces of \p OPT.
2378 /// \returns true if the typo was corrected, in which case the \p Res
2379 /// structure will contain the results of name lookup for the
2380 /// corrected name. Otherwise, returns false.
2381 bool Sema::CorrectTypo(LookupResult &Res, Scope *S, const CXXScopeSpec *SS,
2382 DeclContext *MemberContext, bool EnteringContext,
2383 const ObjCObjectPointerType *OPT) {
2384 if (Diags.hasFatalErrorOccurred())
2387 // Provide a stop gap for files that are just seriously broken. Trying
2388 // to correct all typos can turn into a HUGE performance penalty, causing
2389 // some files to take minutes to get rejected by the parser.
2390 // FIXME: Is this the right solution?
2391 if (TyposCorrected == 20)
2395 // We only attempt to correct typos for identifiers.
2396 IdentifierInfo *Typo = Res.getLookupName().getAsIdentifierInfo();
2400 // If the scope specifier itself was invalid, don't try to correct
2402 if (SS && SS->isInvalid())
2405 // Never try to correct typos during template deduction or
2407 if (!ActiveTemplateInstantiations.empty())
2410 TypoCorrectionConsumer Consumer(Typo);
2411 if (MemberContext) {
2412 LookupVisibleDecls(MemberContext, Res.getLookupKind(), Consumer);
2414 // Look in qualified interfaces.
2416 for (ObjCObjectPointerType::qual_iterator
2417 I = OPT->qual_begin(), E = OPT->qual_end();
2419 LookupVisibleDecls(*I, Res.getLookupKind(), Consumer);
2421 } else if (SS && SS->isSet()) {
2422 DeclContext *DC = computeDeclContext(*SS, EnteringContext);
2426 LookupVisibleDecls(DC, Res.getLookupKind(), Consumer);
2428 LookupVisibleDecls(S, Res.getLookupKind(), Consumer);
2431 if (Consumer.empty())
2434 // Only allow a single, closest name in the result set (it's okay to
2435 // have overloads of that name, though).
2436 TypoCorrectionConsumer::iterator I = Consumer.begin();
2437 DeclarationName BestName = (*I)->getDeclName();
2439 // If we've found an Objective-C ivar or property, don't perform
2440 // name lookup again; we'll just return the result directly.
2441 NamedDecl *FoundBest = 0;
2442 if (isa<ObjCIvarDecl>(*I) || isa<ObjCPropertyDecl>(*I))
2445 for(TypoCorrectionConsumer::iterator IEnd = Consumer.end(); I != IEnd; ++I) {
2446 if (BestName != (*I)->getDeclName())
2449 // FIXME: If there are both ivars and properties of the same name,
2450 // don't return both because the callee can't handle two
2451 // results. We really need to separate ivar lookup from property
2452 // lookup to avoid this problem.
2456 // BestName is the closest viable name to what the user
2457 // typed. However, to make sure that we don't pick something that's
2458 // way off, make sure that the user typed at least 3 characters for
2460 unsigned ED = Consumer.getBestEditDistance();
2461 if (ED == 0 || (BestName.getAsIdentifierInfo()->getName().size() / ED) < 3)
2464 // Perform name lookup again with the name we chose, and declare
2465 // success if we found something that was not ambiguous.
2467 Res.setLookupName(BestName);
2469 // If we found an ivar or property, add that result; no further
2470 // lookup is required.
2472 Res.addDecl(FoundBest);
2473 // If we're looking into the context of a member, perform qualified
2474 // name lookup on the best name.
2475 else if (MemberContext)
2476 LookupQualifiedName(Res, MemberContext);
2477 // Perform lookup as if we had just parsed the best name.
2479 LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
2482 if (Res.isAmbiguous()) {
2483 Res.suppressDiagnostics();
2487 return Res.getResultKind() != LookupResult::NotFound;