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);
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[0]))
328 ResultKind = FoundOverloaded;
329 else if (isa<UnresolvedUsingValueDecl>(Decls[0]))
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::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 // Adds all qualifying matches for a name within a decl context to the
442 // given lookup result. Returns true if any matches were found.
443 static bool LookupDirect(LookupResult &R, const DeclContext *DC) {
446 DeclContext::lookup_const_iterator I, E;
447 for (llvm::tie(I, E) = DC->lookup(R.getLookupName()); I != E; ++I) {
448 if (R.isAcceptableDecl(*I)) {
454 if (R.getLookupName().getNameKind()
455 == DeclarationName::CXXConversionFunctionName &&
456 !R.getLookupName().getCXXNameType()->isDependentType() &&
457 isa<CXXRecordDecl>(DC)) {
459 // A specialization of a conversion function template is not found by
460 // name lookup. Instead, any conversion function templates visible in the
461 // context of the use are considered. [...]
462 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
463 if (!Record->isDefinition())
466 const UnresolvedSet *Unresolved = Record->getConversionFunctions();
467 for (UnresolvedSet::iterator U = Unresolved->begin(),
468 UEnd = Unresolved->end();
470 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
474 // When we're performing lookup for the purposes of redeclaration, just
475 // add the conversion function template. When we deduce template
476 // arguments for specializations, we'll end up unifying the return
477 // type of the new declaration with the type of the function template.
478 if (R.isForRedeclaration()) {
479 R.addDecl(ConvTemplate);
485 // [...] For each such operator, if argument deduction succeeds
486 // (14.9.2.3), the resulting specialization is used as if found by
489 // When referencing a conversion function for any purpose other than
490 // a redeclaration (such that we'll be building an expression with the
491 // result), perform template argument deduction and place the
492 // specialization into the result set. We do this to avoid forcing all
493 // callers to perform special deduction for conversion functions.
494 Sema::TemplateDeductionInfo Info(R.getSema().Context);
495 FunctionDecl *Specialization = 0;
497 const FunctionProtoType *ConvProto
498 = ConvTemplate->getTemplatedDecl()->getType()
499 ->getAs<FunctionProtoType>();
500 assert(ConvProto && "Nonsensical conversion function template type");
502 // Compute the type of the function that we would expect the conversion
503 // function to have, if it were to match the name given.
504 // FIXME: Calling convention!
505 QualType ExpectedType
506 = R.getSema().Context.getFunctionType(
507 R.getLookupName().getCXXNameType(),
508 0, 0, ConvProto->isVariadic(),
509 ConvProto->getTypeQuals(),
511 ConvProto->getNoReturnAttr());
513 // Perform template argument deduction against the type that we would
514 // expect the function to have.
515 if (R.getSema().DeduceTemplateArguments(ConvTemplate, 0, ExpectedType,
516 Specialization, Info)
517 == Sema::TDK_Success) {
518 R.addDecl(Specialization);
527 // Performs C++ unqualified lookup into the given file context.
529 CppNamespaceLookup(LookupResult &R, ASTContext &Context, DeclContext *NS,
530 UnqualUsingDirectiveSet &UDirs) {
532 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
534 // Perform direct name lookup into the LookupCtx.
535 bool Found = LookupDirect(R, NS);
537 // Perform direct name lookup into the namespaces nominated by the
538 // using directives whose common ancestor is this namespace.
539 UnqualUsingDirectiveSet::const_iterator UI, UEnd;
540 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(NS);
542 for (; UI != UEnd; ++UI)
543 if (LookupDirect(R, UI->getNominatedNamespace()))
551 static bool isNamespaceOrTranslationUnitScope(Scope *S) {
552 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()))
553 return Ctx->isFileContext();
557 // Find the next outer declaration context corresponding to this scope.
558 static DeclContext *findOuterContext(Scope *S) {
559 for (S = S->getParent(); S; S = S->getParent())
561 return static_cast<DeclContext *>(S->getEntity())->getPrimaryContext();
566 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
567 assert(getLangOptions().CPlusPlus && "Can perform only C++ lookup");
569 DeclarationName Name = R.getLookupName();
572 IdentifierResolver::iterator
573 I = IdResolver.begin(Name),
574 IEnd = IdResolver.end();
576 // First we lookup local scope.
577 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
578 // ...During unqualified name lookup (3.4.1), the names appear as if
579 // they were declared in the nearest enclosing namespace which contains
580 // both the using-directive and the nominated namespace.
581 // [Note: in this context, "contains" means "contains directly or
585 // namespace A { int i; }
589 // using namespace A;
590 // ++i; // finds local 'i', A::i appears at global scope
594 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
595 // Check whether the IdResolver has anything in this scope.
597 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) {
598 if (R.isAcceptableDecl(*I)) {
608 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) {
609 DeclContext *OuterCtx = findOuterContext(S);
610 for (; Ctx && Ctx->getPrimaryContext() != OuterCtx;
611 Ctx = Ctx->getLookupParent()) {
612 // We do not directly look into function or method contexts
613 // (since all local variables are found via the identifier
614 // changes) or in transparent contexts (since those entities
615 // will be found in the nearest enclosing non-transparent
617 if (Ctx->isFunctionOrMethod() || Ctx->isTransparentContext())
620 // Perform qualified name lookup into this context.
621 // FIXME: In some cases, we know that every name that could be found by
622 // this qualified name lookup will also be on the identifier chain. For
623 // example, inside a class without any base classes, we never need to
624 // perform qualified lookup because all of the members are on top of the
626 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
632 // Stop if we ran out of scopes.
633 // FIXME: This really, really shouldn't be happening.
634 if (!S) return false;
636 // Collect UsingDirectiveDecls in all scopes, and recursively all
637 // nominated namespaces by those using-directives.
639 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
640 // don't build it for each lookup!
642 UnqualUsingDirectiveSet UDirs;
643 UDirs.visitScopeChain(Initial, S);
646 // Lookup namespace scope, and global scope.
647 // Unqualified name lookup in C++ requires looking into scopes
648 // that aren't strictly lexical, and therefore we walk through the
649 // context as well as walking through the scopes.
651 for (; S; S = S->getParent()) {
652 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity());
653 if (!Ctx || Ctx->isTransparentContext())
656 assert(Ctx && Ctx->isFileContext() &&
657 "We should have been looking only at file context here already.");
659 // Check whether the IdResolver has anything in this scope.
661 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) {
662 if (R.isAcceptableDecl(*I)) {
663 // We found something. Look for anything else in our scope
664 // with this same name and in an acceptable identifier
665 // namespace, so that we can construct an overload set if we
672 // Look into context considering using-directives.
673 if (CppNamespaceLookup(R, Context, Ctx, UDirs))
681 if (R.isForRedeclaration() && !Ctx->isTransparentContext())
688 /// @brief Perform unqualified name lookup starting from a given
691 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
692 /// used to find names within the current scope. For example, 'x' in
696 /// return x; // unqualified name look finds 'x' in the global scope
700 /// Different lookup criteria can find different names. For example, a
701 /// particular scope can have both a struct and a function of the same
702 /// name, and each can be found by certain lookup criteria. For more
703 /// information about lookup criteria, see the documentation for the
704 /// class LookupCriteria.
706 /// @param S The scope from which unqualified name lookup will
707 /// begin. If the lookup criteria permits, name lookup may also search
708 /// in the parent scopes.
710 /// @param Name The name of the entity that we are searching for.
712 /// @param Loc If provided, the source location where we're performing
713 /// name lookup. At present, this is only used to produce diagnostics when
714 /// C library functions (like "malloc") are implicitly declared.
716 /// @returns The result of name lookup, which includes zero or more
717 /// declarations and possibly additional information used to diagnose
719 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
720 DeclarationName Name = R.getLookupName();
721 if (!Name) return false;
723 LookupNameKind NameKind = R.getLookupKind();
725 if (!getLangOptions().CPlusPlus) {
726 // Unqualified name lookup in C/Objective-C is purely lexical, so
727 // search in the declarations attached to the name.
729 if (NameKind == Sema::LookupRedeclarationWithLinkage) {
730 // Find the nearest non-transparent declaration scope.
731 while (!(S->getFlags() & Scope::DeclScope) ||
733 static_cast<DeclContext *>(S->getEntity())
734 ->isTransparentContext()))
738 unsigned IDNS = R.getIdentifierNamespace();
740 // Scan up the scope chain looking for a decl that matches this
741 // identifier that is in the appropriate namespace. This search
742 // should not take long, as shadowing of names is uncommon, and
743 // deep shadowing is extremely uncommon.
744 bool LeftStartingScope = false;
746 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
747 IEnd = IdResolver.end();
749 if ((*I)->isInIdentifierNamespace(IDNS)) {
750 if (NameKind == LookupRedeclarationWithLinkage) {
751 // Determine whether this (or a previous) declaration is
753 if (!LeftStartingScope && !S->isDeclScope(DeclPtrTy::make(*I)))
754 LeftStartingScope = true;
756 // If we found something outside of our starting scope that
757 // does not have linkage, skip it.
758 if (LeftStartingScope && !((*I)->hasLinkage()))
764 if ((*I)->getAttr<OverloadableAttr>()) {
765 // If this declaration has the "overloadable" attribute, we
766 // might have a set of overloaded functions.
768 // Figure out what scope the identifier is in.
769 while (!(S->getFlags() & Scope::DeclScope) ||
770 !S->isDeclScope(DeclPtrTy::make(*I)))
773 // Find the last declaration in this scope (with the same
775 IdentifierResolver::iterator LastI = I;
776 for (++LastI; LastI != IEnd; ++LastI) {
777 if (!S->isDeclScope(DeclPtrTy::make(*LastI)))
788 // Perform C++ unqualified name lookup.
789 if (CppLookupName(R, S))
793 // If we didn't find a use of this identifier, and if the identifier
794 // corresponds to a compiler builtin, create the decl object for the builtin
795 // now, injecting it into translation unit scope, and return it.
796 if (NameKind == LookupOrdinaryName ||
797 NameKind == LookupRedeclarationWithLinkage) {
798 IdentifierInfo *II = Name.getAsIdentifierInfo();
799 if (II && AllowBuiltinCreation) {
800 // If this is a builtin on this (or all) targets, create the decl.
801 if (unsigned BuiltinID = II->getBuiltinID()) {
802 // In C++, we don't have any predefined library functions like
803 // 'malloc'. Instead, we'll just error.
804 if (getLangOptions().CPlusPlus &&
805 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
808 NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID,
809 S, R.isForRedeclaration(),
819 /// @brief Perform qualified name lookup in the namespaces nominated by
820 /// using directives by the given context.
822 /// C++98 [namespace.qual]p2:
823 /// Given X::m (where X is a user-declared namespace), or given ::m
824 /// (where X is the global namespace), let S be the set of all
825 /// declarations of m in X and in the transitive closure of all
826 /// namespaces nominated by using-directives in X and its used
827 /// namespaces, except that using-directives are ignored in any
828 /// namespace, including X, directly containing one or more
829 /// declarations of m. No namespace is searched more than once in
830 /// the lookup of a name. If S is the empty set, the program is
831 /// ill-formed. Otherwise, if S has exactly one member, or if the
832 /// context of the reference is a using-declaration
833 /// (namespace.udecl), S is the required set of declarations of
834 /// m. Otherwise if the use of m is not one that allows a unique
835 /// declaration to be chosen from S, the program is ill-formed.
836 /// C++98 [namespace.qual]p5:
837 /// During the lookup of a qualified namespace member name, if the
838 /// lookup finds more than one declaration of the member, and if one
839 /// declaration introduces a class name or enumeration name and the
840 /// other declarations either introduce the same object, the same
841 /// enumerator or a set of functions, the non-type name hides the
842 /// class or enumeration name if and only if the declarations are
843 /// from the same namespace; otherwise (the declarations are from
844 /// different namespaces), the program is ill-formed.
845 static bool LookupQualifiedNameInUsingDirectives(LookupResult &R,
846 DeclContext *StartDC) {
847 assert(StartDC->isFileContext() && "start context is not a file context");
849 DeclContext::udir_iterator I = StartDC->using_directives_begin();
850 DeclContext::udir_iterator E = StartDC->using_directives_end();
852 if (I == E) return false;
854 // We have at least added all these contexts to the queue.
855 llvm::DenseSet<DeclContext*> Visited;
856 Visited.insert(StartDC);
858 // We have not yet looked into these namespaces, much less added
859 // their "using-children" to the queue.
860 llvm::SmallVector<NamespaceDecl*, 8> Queue;
862 // We have already looked into the initial namespace; seed the queue
863 // with its using-children.
864 for (; I != E; ++I) {
865 NamespaceDecl *ND = (*I)->getNominatedNamespace()->getOriginalNamespace();
866 if (Visited.insert(ND).second)
870 // The easiest way to implement the restriction in [namespace.qual]p5
871 // is to check whether any of the individual results found a tag
872 // and, if so, to declare an ambiguity if the final result is not
874 bool FoundTag = false;
875 bool FoundNonTag = false;
877 LookupResult LocalR(LookupResult::Temporary, R);
880 while (!Queue.empty()) {
881 NamespaceDecl *ND = Queue.back();
884 // We go through some convolutions here to avoid copying results
885 // between LookupResults.
886 bool UseLocal = !R.empty();
887 LookupResult &DirectR = UseLocal ? LocalR : R;
888 bool FoundDirect = LookupDirect(DirectR, ND);
891 // First do any local hiding.
892 DirectR.resolveKind();
894 // If the local result is a tag, remember that.
895 if (DirectR.isSingleTagDecl())
900 // Append the local results to the total results if necessary.
902 R.addAllDecls(LocalR);
907 // If we find names in this namespace, ignore its using directives.
913 for (llvm::tie(I,E) = ND->getUsingDirectives(); I != E; ++I) {
914 NamespaceDecl *Nom = (*I)->getNominatedNamespace();
915 if (Visited.insert(Nom).second)
916 Queue.push_back(Nom);
921 if (FoundTag && FoundNonTag)
922 R.setAmbiguousQualifiedTagHiding();
930 /// \brief Perform qualified name lookup into a given context.
932 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
933 /// names when the context of those names is explicit specified, e.g.,
934 /// "std::vector" or "x->member", or as part of unqualified name lookup.
936 /// Different lookup criteria can find different names. For example, a
937 /// particular scope can have both a struct and a function of the same
938 /// name, and each can be found by certain lookup criteria. For more
939 /// information about lookup criteria, see the documentation for the
940 /// class LookupCriteria.
942 /// \param R captures both the lookup criteria and any lookup results found.
944 /// \param LookupCtx The context in which qualified name lookup will
945 /// search. If the lookup criteria permits, name lookup may also search
946 /// in the parent contexts or (for C++ classes) base classes.
948 /// \param InUnqualifiedLookup true if this is qualified name lookup that
949 /// occurs as part of unqualified name lookup.
951 /// \returns true if lookup succeeded, false if it failed.
952 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
953 bool InUnqualifiedLookup) {
954 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
956 if (!R.getLookupName())
959 // Make sure that the declaration context is complete.
960 assert((!isa<TagDecl>(LookupCtx) ||
961 LookupCtx->isDependentContext() ||
962 cast<TagDecl>(LookupCtx)->isDefinition() ||
963 Context.getTypeDeclType(cast<TagDecl>(LookupCtx))->getAs<TagType>()
964 ->isBeingDefined()) &&
965 "Declaration context must already be complete!");
967 // Perform qualified name lookup into the LookupCtx.
968 if (LookupDirect(R, LookupCtx)) {
973 // Don't descend into implied contexts for redeclarations.
974 // C++98 [namespace.qual]p6:
975 // In a declaration for a namespace member in which the
976 // declarator-id is a qualified-id, given that the qualified-id
977 // for the namespace member has the form
978 // nested-name-specifier unqualified-id
979 // the unqualified-id shall name a member of the namespace
980 // designated by the nested-name-specifier.
981 // See also [class.mfct]p5 and [class.static.data]p2.
982 if (R.isForRedeclaration())
985 // If this is a namespace, look it up in the implied namespaces.
986 if (LookupCtx->isFileContext())
987 return LookupQualifiedNameInUsingDirectives(R, LookupCtx);
989 // If this isn't a C++ class, we aren't allowed to look into base
990 // classes, we're done.
991 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
995 // If we're performing qualified name lookup into a dependent class,
996 // then we are actually looking into a current instantiation. If we have any
997 // dependent base classes, then we either have to delay lookup until
998 // template instantiation time (at which point all bases will be available)
999 // or we have to fail.
1000 if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
1001 LookupRec->hasAnyDependentBases()) {
1002 R.setNotFoundInCurrentInstantiation();
1006 // Perform lookup into our base classes.
1008 Paths.setOrigin(LookupRec);
1010 // Look for this member in our base classes
1011 CXXRecordDecl::BaseMatchesCallback *BaseCallback = 0;
1012 switch (R.getLookupKind()) {
1013 case LookupOrdinaryName:
1014 case LookupMemberName:
1015 case LookupRedeclarationWithLinkage:
1016 BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
1020 BaseCallback = &CXXRecordDecl::FindTagMember;
1023 case LookupUsingDeclName:
1024 // This lookup is for redeclarations only.
1026 case LookupOperatorName:
1027 case LookupNamespaceName:
1028 case LookupObjCProtocolName:
1029 case LookupObjCImplementationName:
1030 // These lookups will never find a member in a C++ class (or base class).
1033 case LookupNestedNameSpecifierName:
1034 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember;
1038 if (!LookupRec->lookupInBases(BaseCallback,
1039 R.getLookupName().getAsOpaquePtr(), Paths))
1042 // C++ [class.member.lookup]p2:
1043 // [...] If the resulting set of declarations are not all from
1044 // sub-objects of the same type, or the set has a nonstatic member
1045 // and includes members from distinct sub-objects, there is an
1046 // ambiguity and the program is ill-formed. Otherwise that set is
1047 // the result of the lookup.
1048 // FIXME: support using declarations!
1049 QualType SubobjectType;
1050 int SubobjectNumber = 0;
1051 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
1052 Path != PathEnd; ++Path) {
1053 const CXXBasePathElement &PathElement = Path->back();
1055 // Determine whether we're looking at a distinct sub-object or not.
1056 if (SubobjectType.isNull()) {
1057 // This is the first subobject we've looked at. Record its type.
1058 SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
1059 SubobjectNumber = PathElement.SubobjectNumber;
1060 } else if (SubobjectType
1061 != Context.getCanonicalType(PathElement.Base->getType())) {
1062 // We found members of the given name in two subobjects of
1063 // different types. This lookup is ambiguous.
1064 R.setAmbiguousBaseSubobjectTypes(Paths);
1066 } else if (SubobjectNumber != PathElement.SubobjectNumber) {
1067 // We have a different subobject of the same type.
1069 // C++ [class.member.lookup]p5:
1070 // A static member, a nested type or an enumerator defined in
1071 // a base class T can unambiguously be found even if an object
1072 // has more than one base class subobject of type T.
1073 Decl *FirstDecl = *Path->Decls.first;
1074 if (isa<VarDecl>(FirstDecl) ||
1075 isa<TypeDecl>(FirstDecl) ||
1076 isa<EnumConstantDecl>(FirstDecl))
1079 if (isa<CXXMethodDecl>(FirstDecl)) {
1080 // Determine whether all of the methods are static.
1081 bool AllMethodsAreStatic = true;
1082 for (DeclContext::lookup_iterator Func = Path->Decls.first;
1083 Func != Path->Decls.second; ++Func) {
1084 if (!isa<CXXMethodDecl>(*Func)) {
1085 assert(isa<TagDecl>(*Func) && "Non-function must be a tag decl");
1089 if (!cast<CXXMethodDecl>(*Func)->isStatic()) {
1090 AllMethodsAreStatic = false;
1095 if (AllMethodsAreStatic)
1099 // We have found a nonstatic member name in multiple, distinct
1100 // subobjects. Name lookup is ambiguous.
1101 R.setAmbiguousBaseSubobjects(Paths);
1106 // Lookup in a base class succeeded; return these results.
1108 DeclContext::lookup_iterator I, E;
1109 for (llvm::tie(I,E) = Paths.front().Decls; I != E; ++I)
1115 /// @brief Performs name lookup for a name that was parsed in the
1116 /// source code, and may contain a C++ scope specifier.
1118 /// This routine is a convenience routine meant to be called from
1119 /// contexts that receive a name and an optional C++ scope specifier
1120 /// (e.g., "N::M::x"). It will then perform either qualified or
1121 /// unqualified name lookup (with LookupQualifiedName or LookupName,
1122 /// respectively) on the given name and return those results.
1124 /// @param S The scope from which unqualified name lookup will
1127 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
1129 /// @param Name The name of the entity that name lookup will
1132 /// @param Loc If provided, the source location where we're performing
1133 /// name lookup. At present, this is only used to produce diagnostics when
1134 /// C library functions (like "malloc") are implicitly declared.
1136 /// @param EnteringContext Indicates whether we are going to enter the
1137 /// context of the scope-specifier SS (if present).
1139 /// @returns True if any decls were found (but possibly ambiguous)
1140 bool Sema::LookupParsedName(LookupResult &R, Scope *S, const CXXScopeSpec *SS,
1141 bool AllowBuiltinCreation, bool EnteringContext) {
1142 if (SS && SS->isInvalid()) {
1143 // When the scope specifier is invalid, don't even look for
1148 if (SS && SS->isSet()) {
1149 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
1150 // We have resolved the scope specifier to a particular declaration
1151 // contex, and will perform name lookup in that context.
1152 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS))
1155 R.setContextRange(SS->getRange());
1157 return LookupQualifiedName(R, DC);
1160 // We could not resolve the scope specified to a specific declaration
1161 // context, which means that SS refers to an unknown specialization.
1162 // Name lookup can't find anything in this case.
1166 // Perform unqualified name lookup starting in the given scope.
1167 return LookupName(R, S, AllowBuiltinCreation);
1171 /// @brief Produce a diagnostic describing the ambiguity that resulted
1172 /// from name lookup.
1174 /// @param Result The ambiguous name lookup result.
1176 /// @param Name The name of the entity that name lookup was
1179 /// @param NameLoc The location of the name within the source code.
1181 /// @param LookupRange A source range that provides more
1182 /// source-location information concerning the lookup itself. For
1183 /// example, this range might highlight a nested-name-specifier that
1184 /// precedes the name.
1187 bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
1188 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
1190 DeclarationName Name = Result.getLookupName();
1191 SourceLocation NameLoc = Result.getNameLoc();
1192 SourceRange LookupRange = Result.getContextRange();
1194 switch (Result.getAmbiguityKind()) {
1195 case LookupResult::AmbiguousBaseSubobjects: {
1196 CXXBasePaths *Paths = Result.getBasePaths();
1197 QualType SubobjectType = Paths->front().back().Base->getType();
1198 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
1199 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
1202 DeclContext::lookup_iterator Found = Paths->front().Decls.first;
1203 while (isa<CXXMethodDecl>(*Found) &&
1204 cast<CXXMethodDecl>(*Found)->isStatic())
1207 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
1212 case LookupResult::AmbiguousBaseSubobjectTypes: {
1213 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
1214 << Name << LookupRange;
1216 CXXBasePaths *Paths = Result.getBasePaths();
1217 std::set<Decl *> DeclsPrinted;
1218 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
1219 PathEnd = Paths->end();
1220 Path != PathEnd; ++Path) {
1221 Decl *D = *Path->Decls.first;
1222 if (DeclsPrinted.insert(D).second)
1223 Diag(D->getLocation(), diag::note_ambiguous_member_found);
1229 case LookupResult::AmbiguousTagHiding: {
1230 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
1232 llvm::SmallPtrSet<NamedDecl*,8> TagDecls;
1234 LookupResult::iterator DI, DE = Result.end();
1235 for (DI = Result.begin(); DI != DE; ++DI)
1236 if (TagDecl *TD = dyn_cast<TagDecl>(*DI)) {
1237 TagDecls.insert(TD);
1238 Diag(TD->getLocation(), diag::note_hidden_tag);
1241 for (DI = Result.begin(); DI != DE; ++DI)
1242 if (!isa<TagDecl>(*DI))
1243 Diag((*DI)->getLocation(), diag::note_hiding_object);
1245 // For recovery purposes, go ahead and implement the hiding.
1246 Result.hideDecls(TagDecls);
1251 case LookupResult::AmbiguousReference: {
1252 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
1254 LookupResult::iterator DI = Result.begin(), DE = Result.end();
1255 for (; DI != DE; ++DI)
1256 Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI;
1262 llvm_unreachable("unknown ambiguity kind");
1267 addAssociatedClassesAndNamespaces(QualType T,
1268 ASTContext &Context,
1269 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1270 Sema::AssociatedClassSet &AssociatedClasses);
1272 static void CollectNamespace(Sema::AssociatedNamespaceSet &Namespaces,
1274 if (Ctx->isFileContext())
1275 Namespaces.insert(Ctx);
1278 // \brief Add the associated classes and namespaces for argument-dependent
1279 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2).
1281 addAssociatedClassesAndNamespaces(const TemplateArgument &Arg,
1282 ASTContext &Context,
1283 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1284 Sema::AssociatedClassSet &AssociatedClasses) {
1285 // C++ [basic.lookup.koenig]p2, last bullet:
1287 switch (Arg.getKind()) {
1288 case TemplateArgument::Null:
1291 case TemplateArgument::Type:
1292 // [...] the namespaces and classes associated with the types of the
1293 // template arguments provided for template type parameters (excluding
1294 // template template parameters)
1295 addAssociatedClassesAndNamespaces(Arg.getAsType(), Context,
1296 AssociatedNamespaces,
1300 case TemplateArgument::Template: {
1301 // [...] the namespaces in which any template template arguments are
1302 // defined; and the classes in which any member templates used as
1303 // template template arguments are defined.
1304 TemplateName Template = Arg.getAsTemplate();
1305 if (ClassTemplateDecl *ClassTemplate
1306 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
1307 DeclContext *Ctx = ClassTemplate->getDeclContext();
1308 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1309 AssociatedClasses.insert(EnclosingClass);
1310 // Add the associated namespace for this class.
1311 while (Ctx->isRecord())
1312 Ctx = Ctx->getParent();
1313 CollectNamespace(AssociatedNamespaces, Ctx);
1318 case TemplateArgument::Declaration:
1319 case TemplateArgument::Integral:
1320 case TemplateArgument::Expression:
1321 // [Note: non-type template arguments do not contribute to the set of
1322 // associated namespaces. ]
1325 case TemplateArgument::Pack:
1326 for (TemplateArgument::pack_iterator P = Arg.pack_begin(),
1327 PEnd = Arg.pack_end();
1329 addAssociatedClassesAndNamespaces(*P, Context,
1330 AssociatedNamespaces,
1336 // \brief Add the associated classes and namespaces for
1337 // argument-dependent lookup with an argument of class type
1338 // (C++ [basic.lookup.koenig]p2).
1340 addAssociatedClassesAndNamespaces(CXXRecordDecl *Class,
1341 ASTContext &Context,
1342 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1343 Sema::AssociatedClassSet &AssociatedClasses) {
1344 // C++ [basic.lookup.koenig]p2:
1346 // -- If T is a class type (including unions), its associated
1347 // classes are: the class itself; the class of which it is a
1348 // member, if any; and its direct and indirect base
1349 // classes. Its associated namespaces are the namespaces in
1350 // which its associated classes are defined.
1352 // Add the class of which it is a member, if any.
1353 DeclContext *Ctx = Class->getDeclContext();
1354 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1355 AssociatedClasses.insert(EnclosingClass);
1356 // Add the associated namespace for this class.
1357 while (Ctx->isRecord())
1358 Ctx = Ctx->getParent();
1359 CollectNamespace(AssociatedNamespaces, Ctx);
1361 // Add the class itself. If we've already seen this class, we don't
1362 // need to visit base classes.
1363 if (!AssociatedClasses.insert(Class))
1366 // -- If T is a template-id, its associated namespaces and classes are
1367 // the namespace in which the template is defined; for member
1368 // templates, the member template’s class; the namespaces and classes
1369 // associated with the types of the template arguments provided for
1370 // template type parameters (excluding template template parameters); the
1371 // namespaces in which any template template arguments are defined; and
1372 // the classes in which any member templates used as template template
1373 // arguments are defined. [Note: non-type template arguments do not
1374 // contribute to the set of associated namespaces. ]
1375 if (ClassTemplateSpecializationDecl *Spec
1376 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
1377 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
1378 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1379 AssociatedClasses.insert(EnclosingClass);
1380 // Add the associated namespace for this class.
1381 while (Ctx->isRecord())
1382 Ctx = Ctx->getParent();
1383 CollectNamespace(AssociatedNamespaces, Ctx);
1385 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
1386 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
1387 addAssociatedClassesAndNamespaces(TemplateArgs[I], Context,
1388 AssociatedNamespaces,
1392 // Add direct and indirect base classes along with their associated
1394 llvm::SmallVector<CXXRecordDecl *, 32> Bases;
1395 Bases.push_back(Class);
1396 while (!Bases.empty()) {
1397 // Pop this class off the stack.
1398 Class = Bases.back();
1401 // Visit the base classes.
1402 for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(),
1403 BaseEnd = Class->bases_end();
1404 Base != BaseEnd; ++Base) {
1405 const RecordType *BaseType = Base->getType()->getAs<RecordType>();
1406 // In dependent contexts, we do ADL twice, and the first time around,
1407 // the base type might be a dependent TemplateSpecializationType, or a
1408 // TemplateTypeParmType. If that happens, simply ignore it.
1409 // FIXME: If we want to support export, we probably need to add the
1410 // namespace of the template in a TemplateSpecializationType, or even
1411 // the classes and namespaces of known non-dependent arguments.
1414 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
1415 if (AssociatedClasses.insert(BaseDecl)) {
1416 // Find the associated namespace for this base class.
1417 DeclContext *BaseCtx = BaseDecl->getDeclContext();
1418 while (BaseCtx->isRecord())
1419 BaseCtx = BaseCtx->getParent();
1420 CollectNamespace(AssociatedNamespaces, BaseCtx);
1422 // Make sure we visit the bases of this base class.
1423 if (BaseDecl->bases_begin() != BaseDecl->bases_end())
1424 Bases.push_back(BaseDecl);
1430 // \brief Add the associated classes and namespaces for
1431 // argument-dependent lookup with an argument of type T
1432 // (C++ [basic.lookup.koenig]p2).
1434 addAssociatedClassesAndNamespaces(QualType T,
1435 ASTContext &Context,
1436 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1437 Sema::AssociatedClassSet &AssociatedClasses) {
1438 // C++ [basic.lookup.koenig]p2:
1440 // For each argument type T in the function call, there is a set
1441 // of zero or more associated namespaces and a set of zero or more
1442 // associated classes to be considered. The sets of namespaces and
1443 // classes is determined entirely by the types of the function
1444 // arguments (and the namespace of any template template
1445 // argument). Typedef names and using-declarations used to specify
1446 // the types do not contribute to this set. The sets of namespaces
1447 // and classes are determined in the following way:
1448 T = Context.getCanonicalType(T).getUnqualifiedType();
1450 // -- If T is a pointer to U or an array of U, its associated
1451 // namespaces and classes are those associated with U.
1453 // We handle this by unwrapping pointer and array types immediately,
1454 // to avoid unnecessary recursion.
1456 if (const PointerType *Ptr = T->getAs<PointerType>())
1457 T = Ptr->getPointeeType();
1458 else if (const ArrayType *Ptr = Context.getAsArrayType(T))
1459 T = Ptr->getElementType();
1464 // -- If T is a fundamental type, its associated sets of
1465 // namespaces and classes are both empty.
1466 if (T->getAs<BuiltinType>())
1469 // -- If T is a class type (including unions), its associated
1470 // classes are: the class itself; the class of which it is a
1471 // member, if any; and its direct and indirect base
1472 // classes. Its associated namespaces are the namespaces in
1473 // which its associated classes are defined.
1474 if (const RecordType *ClassType = T->getAs<RecordType>())
1475 if (CXXRecordDecl *ClassDecl
1476 = dyn_cast<CXXRecordDecl>(ClassType->getDecl())) {
1477 addAssociatedClassesAndNamespaces(ClassDecl, Context,
1478 AssociatedNamespaces,
1483 // -- If T is an enumeration type, its associated namespace is
1484 // the namespace in which it is defined. If it is class
1485 // member, its associated class is the member’s class; else
1486 // it has no associated class.
1487 if (const EnumType *EnumT = T->getAs<EnumType>()) {
1488 EnumDecl *Enum = EnumT->getDecl();
1490 DeclContext *Ctx = Enum->getDeclContext();
1491 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1492 AssociatedClasses.insert(EnclosingClass);
1494 // Add the associated namespace for this class.
1495 while (Ctx->isRecord())
1496 Ctx = Ctx->getParent();
1497 CollectNamespace(AssociatedNamespaces, Ctx);
1502 // -- If T is a function type, its associated namespaces and
1503 // classes are those associated with the function parameter
1504 // types and those associated with the return type.
1505 if (const FunctionType *FnType = T->getAs<FunctionType>()) {
1507 addAssociatedClassesAndNamespaces(FnType->getResultType(),
1509 AssociatedNamespaces, AssociatedClasses);
1511 const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FnType);
1516 for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(),
1517 ArgEnd = Proto->arg_type_end();
1518 Arg != ArgEnd; ++Arg)
1519 addAssociatedClassesAndNamespaces(*Arg, Context,
1520 AssociatedNamespaces, AssociatedClasses);
1525 // -- If T is a pointer to a member function of a class X, its
1526 // associated namespaces and classes are those associated
1527 // with the function parameter types and return type,
1528 // together with those associated with X.
1530 // -- If T is a pointer to a data member of class X, its
1531 // associated namespaces and classes are those associated
1532 // with the member type together with those associated with
1534 if (const MemberPointerType *MemberPtr = T->getAs<MemberPointerType>()) {
1535 // Handle the type that the pointer to member points to.
1536 addAssociatedClassesAndNamespaces(MemberPtr->getPointeeType(),
1538 AssociatedNamespaces,
1541 // Handle the class type into which this points.
1542 if (const RecordType *Class = MemberPtr->getClass()->getAs<RecordType>())
1543 addAssociatedClassesAndNamespaces(cast<CXXRecordDecl>(Class->getDecl()),
1545 AssociatedNamespaces,
1551 // FIXME: What about block pointers?
1552 // FIXME: What about Objective-C message sends?
1555 /// \brief Find the associated classes and namespaces for
1556 /// argument-dependent lookup for a call with the given set of
1559 /// This routine computes the sets of associated classes and associated
1560 /// namespaces searched by argument-dependent lookup
1561 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
1563 Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs,
1564 AssociatedNamespaceSet &AssociatedNamespaces,
1565 AssociatedClassSet &AssociatedClasses) {
1566 AssociatedNamespaces.clear();
1567 AssociatedClasses.clear();
1569 // C++ [basic.lookup.koenig]p2:
1570 // For each argument type T in the function call, there is a set
1571 // of zero or more associated namespaces and a set of zero or more
1572 // associated classes to be considered. The sets of namespaces and
1573 // classes is determined entirely by the types of the function
1574 // arguments (and the namespace of any template template
1576 for (unsigned ArgIdx = 0; ArgIdx != NumArgs; ++ArgIdx) {
1577 Expr *Arg = Args[ArgIdx];
1579 if (Arg->getType() != Context.OverloadTy) {
1580 addAssociatedClassesAndNamespaces(Arg->getType(), Context,
1581 AssociatedNamespaces,
1586 // [...] In addition, if the argument is the name or address of a
1587 // set of overloaded functions and/or function templates, its
1588 // associated classes and namespaces are the union of those
1589 // associated with each of the members of the set: the namespace
1590 // in which the function or function template is defined and the
1591 // classes and namespaces associated with its (non-dependent)
1592 // parameter types and return type.
1593 Arg = Arg->IgnoreParens();
1594 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg))
1595 if (unaryOp->getOpcode() == UnaryOperator::AddrOf)
1596 Arg = unaryOp->getSubExpr();
1598 // TODO: avoid the copies. This should be easy when the cases
1599 // share a storage implementation.
1600 llvm::SmallVector<NamedDecl*, 8> Functions;
1602 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg))
1603 Functions.append(ULE->decls_begin(), ULE->decls_end());
1607 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Functions.begin(),
1608 E = Functions.end(); I != E; ++I) {
1609 // Look through any using declarations to find the underlying function.
1610 NamedDecl *Fn = (*I)->getUnderlyingDecl();
1612 FunctionDecl *FDecl = dyn_cast<FunctionDecl>(Fn);
1614 FDecl = cast<FunctionTemplateDecl>(Fn)->getTemplatedDecl();
1616 // Add the classes and namespaces associated with the parameter
1617 // types and return type of this function.
1618 addAssociatedClassesAndNamespaces(FDecl->getType(), Context,
1619 AssociatedNamespaces,
1625 /// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
1626 /// an acceptable non-member overloaded operator for a call whose
1627 /// arguments have types T1 (and, if non-empty, T2). This routine
1628 /// implements the check in C++ [over.match.oper]p3b2 concerning
1629 /// enumeration types.
1631 IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn,
1632 QualType T1, QualType T2,
1633 ASTContext &Context) {
1634 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
1637 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
1640 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
1641 if (Proto->getNumArgs() < 1)
1644 if (T1->isEnumeralType()) {
1645 QualType ArgType = Proto->getArgType(0).getNonReferenceType();
1646 if (Context.hasSameUnqualifiedType(T1, ArgType))
1650 if (Proto->getNumArgs() < 2)
1653 if (!T2.isNull() && T2->isEnumeralType()) {
1654 QualType ArgType = Proto->getArgType(1).getNonReferenceType();
1655 if (Context.hasSameUnqualifiedType(T2, ArgType))
1662 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
1663 LookupNameKind NameKind,
1664 RedeclarationKind Redecl) {
1665 LookupResult R(*this, Name, SourceLocation(), NameKind, Redecl);
1667 return R.getAsSingle<NamedDecl>();
1670 /// \brief Find the protocol with the given name, if any.
1671 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II) {
1672 Decl *D = LookupSingleName(TUScope, II, LookupObjCProtocolName);
1673 return cast_or_null<ObjCProtocolDecl>(D);
1676 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
1677 QualType T1, QualType T2,
1678 FunctionSet &Functions) {
1679 // C++ [over.match.oper]p3:
1680 // -- The set of non-member candidates is the result of the
1681 // unqualified lookup of operator@ in the context of the
1682 // expression according to the usual rules for name lookup in
1683 // unqualified function calls (3.4.2) except that all member
1684 // functions are ignored. However, if no operand has a class
1685 // type, only those non-member functions in the lookup set
1686 // that have a first parameter of type T1 or "reference to
1687 // (possibly cv-qualified) T1", when T1 is an enumeration
1688 // type, or (if there is a right operand) a second parameter
1689 // of type T2 or "reference to (possibly cv-qualified) T2",
1690 // when T2 is an enumeration type, are candidate functions.
1691 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
1692 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
1693 LookupName(Operators, S);
1695 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
1697 if (Operators.empty())
1700 for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end();
1701 Op != OpEnd; ++Op) {
1702 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Op)) {
1703 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context))
1704 Functions.insert(FD); // FIXME: canonical FD
1705 } else if (FunctionTemplateDecl *FunTmpl
1706 = dyn_cast<FunctionTemplateDecl>(*Op)) {
1707 // FIXME: friend operators?
1708 // FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate,
1710 if (!FunTmpl->getDeclContext()->isRecord())
1711 Functions.insert(FunTmpl);
1716 static void CollectFunctionDecl(Sema::FunctionSet &Functions,
1718 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(D))
1719 Functions.insert(Func);
1720 else if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D))
1721 Functions.insert(FunTmpl);
1724 void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator,
1725 Expr **Args, unsigned NumArgs,
1726 FunctionSet &Functions) {
1727 // Find all of the associated namespaces and classes based on the
1728 // arguments we have.
1729 AssociatedNamespaceSet AssociatedNamespaces;
1730 AssociatedClassSet AssociatedClasses;
1731 FindAssociatedClassesAndNamespaces(Args, NumArgs,
1732 AssociatedNamespaces,
1737 T1 = Args[0]->getType();
1739 T2 = Args[1]->getType();
1742 // C++ [basic.lookup.argdep]p3:
1743 // Let X be the lookup set produced by unqualified lookup (3.4.1)
1744 // and let Y be the lookup set produced by argument dependent
1745 // lookup (defined as follows). If X contains [...] then Y is
1746 // empty. Otherwise Y is the set of declarations found in the
1747 // namespaces associated with the argument types as described
1748 // below. The set of declarations found by the lookup of the name
1749 // is the union of X and Y.
1751 // Here, we compute Y and add its members to the overloaded
1753 for (AssociatedNamespaceSet::iterator NS = AssociatedNamespaces.begin(),
1754 NSEnd = AssociatedNamespaces.end();
1755 NS != NSEnd; ++NS) {
1756 // When considering an associated namespace, the lookup is the
1757 // same as the lookup performed when the associated namespace is
1758 // used as a qualifier (3.4.3.2) except that:
1760 // -- Any using-directives in the associated namespace are
1763 // -- Any namespace-scope friend functions declared in
1764 // associated classes are visible within their respective
1765 // namespaces even if they are not visible during an ordinary
1767 DeclContext::lookup_iterator I, E;
1768 for (llvm::tie(I, E) = (*NS)->lookup(Name); I != E; ++I) {
1770 // If the only declaration here is an ordinary friend, consider
1771 // it only if it was declared in an associated classes.
1772 if (D->getIdentifierNamespace() == Decl::IDNS_OrdinaryFriend) {
1773 DeclContext *LexDC = D->getLexicalDeclContext();
1774 if (!AssociatedClasses.count(cast<CXXRecordDecl>(LexDC)))
1779 if (!Operator || !(Fn = dyn_cast<FunctionDecl>(D)) ||
1780 IsAcceptableNonMemberOperatorCandidate(Fn, T1, T2, Context))
1781 CollectFunctionDecl(Functions, D);
1786 //----------------------------------------------------------------------------
1787 // Search for all visible declarations.
1788 //----------------------------------------------------------------------------
1789 VisibleDeclConsumer::~VisibleDeclConsumer() { }
1793 class ShadowContextRAII;
1795 class VisibleDeclsRecord {
1797 /// \brief An entry in the shadow map, which is optimized to store a
1798 /// single declaration (the common case) but can also store a list
1799 /// of declarations.
1800 class ShadowMapEntry {
1801 typedef llvm::SmallVector<NamedDecl *, 4> DeclVector;
1803 /// \brief Contains either the solitary NamedDecl * or a vector
1804 /// of declarations.
1805 llvm::PointerUnion<NamedDecl *, DeclVector*> DeclOrVector;
1808 ShadowMapEntry() : DeclOrVector() { }
1810 void Add(NamedDecl *ND);
1814 typedef NamedDecl **iterator;
1820 /// \brief A mapping from declaration names to the declarations that have
1821 /// this name within a particular scope.
1822 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
1824 /// \brief A list of shadow maps, which is used to model name hiding.
1825 std::list<ShadowMap> ShadowMaps;
1827 /// \brief The declaration contexts we have already visited.
1828 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
1830 friend class ShadowContextRAII;
1833 /// \brief Determine whether we have already visited this context
1834 /// (and, if not, note that we are going to visit that context now).
1835 bool visitedContext(DeclContext *Ctx) {
1836 return !VisitedContexts.insert(Ctx);
1839 /// \brief Determine whether the given declaration is hidden in the
1842 /// \returns the declaration that hides the given declaration, or
1843 /// NULL if no such declaration exists.
1844 NamedDecl *checkHidden(NamedDecl *ND);
1846 /// \brief Add a declaration to the current shadow map.
1847 void add(NamedDecl *ND) { ShadowMaps.back()[ND->getDeclName()].Add(ND); }
1850 /// \brief RAII object that records when we've entered a shadow context.
1851 class ShadowContextRAII {
1852 VisibleDeclsRecord &Visible;
1854 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
1857 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
1858 Visible.ShadowMaps.push_back(ShadowMap());
1861 ~ShadowContextRAII() {
1862 for (ShadowMap::iterator E = Visible.ShadowMaps.back().begin(),
1863 EEnd = Visible.ShadowMaps.back().end();
1866 E->second.Destroy();
1868 Visible.ShadowMaps.pop_back();
1872 } // end anonymous namespace
1874 void VisibleDeclsRecord::ShadowMapEntry::Add(NamedDecl *ND) {
1875 if (DeclOrVector.isNull()) {
1876 // 0 - > 1 elements: just set the single element information.
1881 if (NamedDecl *PrevND = DeclOrVector.dyn_cast<NamedDecl *>()) {
1882 // 1 -> 2 elements: create the vector of results and push in the
1883 // existing declaration.
1884 DeclVector *Vec = new DeclVector;
1885 Vec->push_back(PrevND);
1889 // Add the new element to the end of the vector.
1890 DeclOrVector.get<DeclVector*>()->push_back(ND);
1893 void VisibleDeclsRecord::ShadowMapEntry::Destroy() {
1894 if (DeclVector *Vec = DeclOrVector.dyn_cast<DeclVector *>()) {
1896 DeclOrVector = ((NamedDecl *)0);
1900 VisibleDeclsRecord::ShadowMapEntry::iterator
1901 VisibleDeclsRecord::ShadowMapEntry::begin() {
1902 if (DeclOrVector.isNull())
1905 if (DeclOrVector.dyn_cast<NamedDecl *>())
1906 return &reinterpret_cast<NamedDecl*&>(DeclOrVector);
1908 return DeclOrVector.get<DeclVector *>()->begin();
1911 VisibleDeclsRecord::ShadowMapEntry::iterator
1912 VisibleDeclsRecord::ShadowMapEntry::end() {
1913 if (DeclOrVector.isNull())
1916 if (DeclOrVector.dyn_cast<NamedDecl *>())
1917 return &reinterpret_cast<NamedDecl*&>(DeclOrVector) + 1;
1919 return DeclOrVector.get<DeclVector *>()->end();
1922 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
1923 // Look through using declarations.
1924 ND = ND->getUnderlyingDecl();
1926 unsigned IDNS = ND->getIdentifierNamespace();
1927 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
1928 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
1929 SM != SMEnd; ++SM) {
1930 ShadowMap::iterator Pos = SM->find(ND->getDeclName());
1931 if (Pos == SM->end())
1934 for (ShadowMapEntry::iterator I = Pos->second.begin(),
1935 IEnd = Pos->second.end();
1937 // A tag declaration does not hide a non-tag declaration.
1938 if ((*I)->getIdentifierNamespace() == Decl::IDNS_Tag &&
1939 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
1940 Decl::IDNS_ObjCProtocol)))
1943 // Protocols are in distinct namespaces from everything else.
1944 if ((((*I)->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
1945 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
1946 (*I)->getIdentifierNamespace() != IDNS)
1949 // Functions and function templates in the same scope overload
1950 // rather than hide. FIXME: Look for hiding based on function
1952 if ((*I)->isFunctionOrFunctionTemplate() &&
1953 ND->isFunctionOrFunctionTemplate() &&
1954 SM == ShadowMaps.rbegin())
1957 // We've found a declaration that hides this one.
1965 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
1966 bool QualifiedNameLookup,
1968 VisibleDeclConsumer &Consumer,
1969 VisibleDeclsRecord &Visited) {
1970 // Make sure we don't visit the same context twice.
1971 if (Visited.visitedContext(Ctx->getPrimaryContext()))
1974 // Enumerate all of the results in this context.
1975 for (DeclContext *CurCtx = Ctx->getPrimaryContext(); CurCtx;
1976 CurCtx = CurCtx->getNextContext()) {
1977 for (DeclContext::decl_iterator D = CurCtx->decls_begin(),
1978 DEnd = CurCtx->decls_end();
1980 if (NamedDecl *ND = dyn_cast<NamedDecl>(*D))
1981 if (Result.isAcceptableDecl(ND)) {
1982 Consumer.FoundDecl(ND, Visited.checkHidden(ND), InBaseClass);
1986 // Visit transparent contexts inside this context.
1987 if (DeclContext *InnerCtx = dyn_cast<DeclContext>(*D)) {
1988 if (InnerCtx->isTransparentContext())
1989 LookupVisibleDecls(InnerCtx, Result, QualifiedNameLookup, InBaseClass,
1995 // Traverse using directives for qualified name lookup.
1996 if (QualifiedNameLookup) {
1997 ShadowContextRAII Shadow(Visited);
1998 DeclContext::udir_iterator I, E;
1999 for (llvm::tie(I, E) = Ctx->getUsingDirectives(); I != E; ++I) {
2000 LookupVisibleDecls((*I)->getNominatedNamespace(), Result,
2001 QualifiedNameLookup, InBaseClass, Consumer, Visited);
2005 // Traverse the contexts of inherited C++ classes.
2006 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
2007 for (CXXRecordDecl::base_class_iterator B = Record->bases_begin(),
2008 BEnd = Record->bases_end();
2010 QualType BaseType = B->getType();
2012 // Don't look into dependent bases, because name lookup can't look
2014 if (BaseType->isDependentType())
2017 const RecordType *Record = BaseType->getAs<RecordType>();
2021 // FIXME: It would be nice to be able to determine whether referencing
2022 // a particular member would be ambiguous. For example, given
2024 // struct A { int member; };
2025 // struct B { int member; };
2026 // struct C : A, B { };
2028 // void f(C *c) { c->### }
2030 // accessing 'member' would result in an ambiguity. However, we
2031 // could be smart enough to qualify the member with the base
2040 // Find results in this base class (and its bases).
2041 ShadowContextRAII Shadow(Visited);
2042 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup,
2043 true, Consumer, Visited);
2047 // Traverse the contexts of Objective-C classes.
2048 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
2049 // Traverse categories.
2050 for (ObjCCategoryDecl *Category = IFace->getCategoryList();
2051 Category; Category = Category->getNextClassCategory()) {
2052 ShadowContextRAII Shadow(Visited);
2053 LookupVisibleDecls(Category, Result, QualifiedNameLookup, false,
2057 // Traverse protocols.
2058 for (ObjCInterfaceDecl::protocol_iterator I = IFace->protocol_begin(),
2059 E = IFace->protocol_end(); I != E; ++I) {
2060 ShadowContextRAII Shadow(Visited);
2061 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer,
2065 // Traverse the superclass.
2066 if (IFace->getSuperClass()) {
2067 ShadowContextRAII Shadow(Visited);
2068 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup,
2069 true, Consumer, Visited);
2071 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
2072 for (ObjCProtocolDecl::protocol_iterator I = Protocol->protocol_begin(),
2073 E = Protocol->protocol_end(); I != E; ++I) {
2074 ShadowContextRAII Shadow(Visited);
2075 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer,
2078 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
2079 for (ObjCCategoryDecl::protocol_iterator I = Category->protocol_begin(),
2080 E = Category->protocol_end(); I != E; ++I) {
2081 ShadowContextRAII Shadow(Visited);
2082 LookupVisibleDecls(*I, Result, QualifiedNameLookup, false, Consumer,
2088 static void LookupVisibleDecls(Scope *S, LookupResult &Result,
2089 UnqualUsingDirectiveSet &UDirs,
2090 VisibleDeclConsumer &Consumer,
2091 VisibleDeclsRecord &Visited) {
2095 if (!S->getEntity() || !S->getParent() ||
2096 ((DeclContext *)S->getEntity())->isFunctionOrMethod()) {
2097 // Walk through the declarations in this Scope.
2098 for (Scope::decl_iterator D = S->decl_begin(), DEnd = S->decl_end();
2100 if (NamedDecl *ND = dyn_cast<NamedDecl>((Decl *)((*D).get())))
2101 if (Result.isAcceptableDecl(ND)) {
2102 Consumer.FoundDecl(ND, Visited.checkHidden(ND), false);
2108 DeclContext *Entity = 0;
2109 if (S->getEntity()) {
2110 // Look into this scope's declaration context, along with any of its
2111 // parent lookup contexts (e.g., enclosing classes), up to the point
2112 // where we hit the context stored in the next outer scope.
2113 Entity = (DeclContext *)S->getEntity();
2114 DeclContext *OuterCtx = findOuterContext(S);
2116 for (DeclContext *Ctx = Entity; Ctx && Ctx->getPrimaryContext() != OuterCtx;
2117 Ctx = Ctx->getLookupParent()) {
2118 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
2119 if (Method->isInstanceMethod()) {
2120 // For instance methods, look for ivars in the method's interface.
2121 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
2122 Result.getNameLoc(), Sema::LookupMemberName);
2123 ObjCInterfaceDecl *IFace = Method->getClassInterface();
2124 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false,
2125 /*InBaseClass=*/false, Consumer, Visited);
2128 // We've already performed all of the name lookup that we need
2129 // to for Objective-C methods; the next context will be the
2134 if (Ctx->isFunctionOrMethod())
2137 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false,
2138 /*InBaseClass=*/false, Consumer, Visited);
2140 } else if (!S->getParent()) {
2141 // Look into the translation unit scope. We walk through the translation
2142 // unit's declaration context, because the Scope itself won't have all of
2143 // the declarations if we loaded a precompiled header.
2144 // FIXME: We would like the translation unit's Scope object to point to the
2145 // translation unit, so we don't need this special "if" branch. However,
2146 // doing so would force the normal C++ name-lookup code to look into the
2147 // translation unit decl when the IdentifierInfo chains would suffice.
2148 // Once we fix that problem (which is part of a more general "don't look
2149 // in DeclContexts unless we have to" optimization), we can eliminate this.
2150 Entity = Result.getSema().Context.getTranslationUnitDecl();
2151 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false,
2152 /*InBaseClass=*/false, Consumer, Visited);
2156 // Lookup visible declarations in any namespaces found by using
2158 UnqualUsingDirectiveSet::const_iterator UI, UEnd;
2159 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(Entity);
2160 for (; UI != UEnd; ++UI)
2161 LookupVisibleDecls(const_cast<DeclContext *>(UI->getNominatedNamespace()),
2162 Result, /*QualifiedNameLookup=*/false,
2163 /*InBaseClass=*/false, Consumer, Visited);
2166 // Lookup names in the parent scope.
2167 ShadowContextRAII Shadow(Visited);
2168 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited);
2171 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
2172 VisibleDeclConsumer &Consumer) {
2173 // Determine the set of using directives available during
2174 // unqualified name lookup.
2176 UnqualUsingDirectiveSet UDirs;
2177 if (getLangOptions().CPlusPlus) {
2178 // Find the first namespace or translation-unit scope.
2179 while (S && !isNamespaceOrTranslationUnitScope(S))
2182 UDirs.visitScopeChain(Initial, S);
2186 // Look for visible declarations.
2187 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
2188 VisibleDeclsRecord Visited;
2189 ShadowContextRAII Shadow(Visited);
2190 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited);
2193 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
2194 VisibleDeclConsumer &Consumer) {
2195 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
2196 VisibleDeclsRecord Visited;
2197 ShadowContextRAII Shadow(Visited);
2198 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true,
2199 /*InBaseClass=*/false, Consumer, Visited);
2202 //----------------------------------------------------------------------------
2204 //----------------------------------------------------------------------------
2207 class TypoCorrectionConsumer : public VisibleDeclConsumer {
2208 /// \brief The name written that is a typo in the source.
2209 llvm::StringRef Typo;
2211 /// \brief The results found that have the smallest edit distance
2212 /// found (so far) with the typo name.
2213 llvm::SmallVector<NamedDecl *, 4> BestResults;
2215 /// \brief The best edit distance found so far.
2216 unsigned BestEditDistance;
2219 explicit TypoCorrectionConsumer(IdentifierInfo *Typo)
2220 : Typo(Typo->getName()) { }
2222 virtual void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, bool InBaseClass);
2224 typedef llvm::SmallVector<NamedDecl *, 4>::const_iterator iterator;
2225 iterator begin() const { return BestResults.begin(); }
2226 iterator end() const { return BestResults.end(); }
2227 bool empty() const { return BestResults.empty(); }
2229 unsigned getBestEditDistance() const { return BestEditDistance; }
2234 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
2236 // Don't consider hidden names for typo correction.
2240 // Only consider entities with identifiers for names, ignoring
2241 // special names (constructors, overloaded operators, selectors,
2243 IdentifierInfo *Name = ND->getIdentifier();
2247 // Compute the edit distance between the typo and the name of this
2248 // entity. If this edit distance is not worse than the best edit
2249 // distance we've seen so far, add it to the list of results.
2250 unsigned ED = Typo.edit_distance(Name->getName());
2251 if (!BestResults.empty()) {
2252 if (ED < BestEditDistance) {
2253 // This result is better than any we've seen before; clear out
2254 // the previous results.
2255 BestResults.clear();
2256 BestEditDistance = ED;
2257 } else if (ED > BestEditDistance) {
2258 // This result is worse than the best results we've seen so far;
2263 BestEditDistance = ED;
2265 BestResults.push_back(ND);
2268 /// \brief Try to "correct" a typo in the source code by finding
2269 /// visible declarations whose names are similar to the name that was
2270 /// present in the source code.
2272 /// \param Res the \c LookupResult structure that contains the name
2273 /// that was present in the source code along with the name-lookup
2274 /// criteria used to search for the name. On success, this structure
2275 /// will contain the results of name lookup.
2277 /// \param S the scope in which name lookup occurs.
2279 /// \param SS the nested-name-specifier that precedes the name we're
2280 /// looking for, if present.
2282 /// \param MemberContext if non-NULL, the context in which to look for
2283 /// a member access expression.
2285 /// \param EnteringContext whether we're entering the context described by
2286 /// the nested-name-specifier SS.
2288 /// \param OPT when non-NULL, the search for visible declarations will
2289 /// also walk the protocols in the qualified interfaces of \p OPT.
2291 /// \returns true if the typo was corrected, in which case the \p Res
2292 /// structure will contain the results of name lookup for the
2293 /// corrected name. Otherwise, returns false.
2294 bool Sema::CorrectTypo(LookupResult &Res, Scope *S, const CXXScopeSpec *SS,
2295 DeclContext *MemberContext, bool EnteringContext,
2296 const ObjCObjectPointerType *OPT) {
2298 if (Diags.hasFatalErrorOccurred())
2301 // We only attempt to correct typos for identifiers.
2302 IdentifierInfo *Typo = Res.getLookupName().getAsIdentifierInfo();
2306 // If the scope specifier itself was invalid, don't try to correct
2308 if (SS && SS->isInvalid())
2311 // Never try to correct typos during template deduction or
2313 if (!ActiveTemplateInstantiations.empty())
2316 TypoCorrectionConsumer Consumer(Typo);
2317 if (MemberContext) {
2318 LookupVisibleDecls(MemberContext, Res.getLookupKind(), Consumer);
2320 // Look in qualified interfaces.
2322 for (ObjCObjectPointerType::qual_iterator
2323 I = OPT->qual_begin(), E = OPT->qual_end();
2325 LookupVisibleDecls(*I, Res.getLookupKind(), Consumer);
2327 } else if (SS && SS->isSet()) {
2328 DeclContext *DC = computeDeclContext(*SS, EnteringContext);
2332 LookupVisibleDecls(DC, Res.getLookupKind(), Consumer);
2334 LookupVisibleDecls(S, Res.getLookupKind(), Consumer);
2337 if (Consumer.empty())
2340 // Only allow a single, closest name in the result set (it's okay to
2341 // have overloads of that name, though).
2342 TypoCorrectionConsumer::iterator I = Consumer.begin();
2343 DeclarationName BestName = (*I)->getDeclName();
2345 // If we've found an Objective-C ivar or property, don't perform
2346 // name lookup again; we'll just return the result directly.
2347 NamedDecl *FoundBest = 0;
2348 if (isa<ObjCIvarDecl>(*I) || isa<ObjCPropertyDecl>(*I))
2351 for(TypoCorrectionConsumer::iterator IEnd = Consumer.end(); I != IEnd; ++I) {
2352 if (BestName != (*I)->getDeclName())
2355 // FIXME: If there are both ivars and properties of the same name,
2356 // don't return both because the callee can't handle two
2357 // results. We really need to separate ivar lookup from property
2358 // lookup to avoid this problem.
2362 // BestName is the closest viable name to what the user
2363 // typed. However, to make sure that we don't pick something that's
2364 // way off, make sure that the user typed at least 3 characters for
2366 unsigned ED = Consumer.getBestEditDistance();
2367 if (ED == 0 || (BestName.getAsIdentifierInfo()->getName().size() / ED) < 3)
2370 // Perform name lookup again with the name we chose, and declare
2371 // success if we found something that was not ambiguous.
2373 Res.setLookupName(BestName);
2375 // If we found an ivar or property, add that result; no further
2376 // lookup is required.
2378 Res.addDecl(FoundBest);
2379 // If we're looking into the context of a member, perform qualified
2380 // name lookup on the best name.
2381 else if (MemberContext)
2382 LookupQualifiedName(Res, MemberContext);
2383 // Perform lookup as if we had just parsed the best name.
2385 LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
2388 if (Res.isAmbiguous()) {
2389 Res.suppressDiagnostics();
2393 return Res.getResultKind() != LookupResult::NotFound;