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"
36 using namespace clang;
39 class UnqualUsingEntry {
40 const DeclContext *Nominated;
41 const DeclContext *CommonAncestor;
44 UnqualUsingEntry(const DeclContext *Nominated,
45 const DeclContext *CommonAncestor)
46 : Nominated(Nominated), CommonAncestor(CommonAncestor) {
49 const DeclContext *getCommonAncestor() const {
50 return CommonAncestor;
53 const DeclContext *getNominatedNamespace() const {
57 // Sort by the pointer value of the common ancestor.
59 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) {
60 return L.getCommonAncestor() < R.getCommonAncestor();
63 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) {
64 return E.getCommonAncestor() < DC;
67 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) {
68 return DC < E.getCommonAncestor();
73 /// A collection of using directives, as used by C++ unqualified
75 class UnqualUsingDirectiveSet {
76 typedef llvm::SmallVector<UnqualUsingEntry, 8> ListTy;
79 llvm::SmallPtrSet<DeclContext*, 8> visited;
82 UnqualUsingDirectiveSet() {}
84 void visitScopeChain(Scope *S, Scope *InnermostFileScope) {
85 // C++ [namespace.udir]p1:
86 // During unqualified name lookup, the names appear as if they
87 // were declared in the nearest enclosing namespace which contains
88 // both the using-directive and the nominated namespace.
89 DeclContext *InnermostFileDC
90 = static_cast<DeclContext*>(InnermostFileScope->getEntity());
91 assert(InnermostFileDC && InnermostFileDC->isFileContext());
93 for (; S; S = S->getParent()) {
94 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) {
95 DeclContext *EffectiveDC = (Ctx->isFileContext() ? Ctx : InnermostFileDC);
96 visit(Ctx, EffectiveDC);
98 Scope::udir_iterator I = S->using_directives_begin(),
99 End = S->using_directives_end();
101 for (; I != End; ++I)
102 visit(I->getAs<UsingDirectiveDecl>(), InnermostFileDC);
107 // Visits a context and collect all of its using directives
108 // recursively. Treats all using directives as if they were
109 // declared in the context.
111 // A given context is only every visited once, so it is important
112 // that contexts be visited from the inside out in order to get
113 // the effective DCs right.
114 void visit(DeclContext *DC, DeclContext *EffectiveDC) {
115 if (!visited.insert(DC))
118 addUsingDirectives(DC, EffectiveDC);
121 // Visits a using directive and collects all of its using
122 // directives recursively. Treats all using directives as if they
123 // were declared in the effective DC.
124 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
125 DeclContext *NS = UD->getNominatedNamespace();
126 if (!visited.insert(NS))
129 addUsingDirective(UD, EffectiveDC);
130 addUsingDirectives(NS, EffectiveDC);
133 // Adds all the using directives in a context (and those nominated
134 // by its using directives, transitively) as if they appeared in
135 // the given effective context.
136 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) {
137 llvm::SmallVector<DeclContext*,4> queue;
139 DeclContext::udir_iterator I, End;
140 for (llvm::tie(I, End) = DC->getUsingDirectives(); I != End; ++I) {
141 UsingDirectiveDecl *UD = *I;
142 DeclContext *NS = UD->getNominatedNamespace();
143 if (visited.insert(NS)) {
144 addUsingDirective(UD, EffectiveDC);
157 // Add a using directive as if it had been declared in the given
158 // context. This helps implement C++ [namespace.udir]p3:
159 // The using-directive is transitive: if a scope contains a
160 // using-directive that nominates a second namespace that itself
161 // contains using-directives, the effect is as if the
162 // using-directives from the second namespace also appeared in
164 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
165 // Find the common ancestor between the effective context and
166 // the nominated namespace.
167 DeclContext *Common = UD->getNominatedNamespace();
168 while (!Common->Encloses(EffectiveDC))
169 Common = Common->getParent();
170 Common = Common->getPrimaryContext();
172 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common));
176 std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator());
179 typedef ListTy::iterator iterator;
180 typedef ListTy::const_iterator const_iterator;
182 iterator begin() { return list.begin(); }
183 iterator end() { return list.end(); }
184 const_iterator begin() const { return list.begin(); }
185 const_iterator end() const { return list.end(); }
187 std::pair<const_iterator,const_iterator>
188 getNamespacesFor(DeclContext *DC) const {
189 return std::equal_range(begin(), end(), DC->getPrimaryContext(),
190 UnqualUsingEntry::Comparator());
195 // Retrieve the set of identifier namespaces that correspond to a
196 // specific kind of name lookup.
198 getIdentifierNamespacesFromLookupNameKind(Sema::LookupNameKind NameKind,
202 case Sema::LookupOrdinaryName:
203 case Sema::LookupOperatorName:
204 case Sema::LookupRedeclarationWithLinkage:
205 IDNS = Decl::IDNS_Ordinary;
207 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member;
210 case Sema::LookupTagName:
211 IDNS = Decl::IDNS_Tag;
214 case Sema::LookupMemberName:
215 IDNS = Decl::IDNS_Member;
217 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary;
220 case Sema::LookupNestedNameSpecifierName:
221 case Sema::LookupNamespaceName:
222 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member;
225 case Sema::LookupObjCProtocolName:
226 IDNS = Decl::IDNS_ObjCProtocol;
229 case Sema::LookupObjCImplementationName:
230 IDNS = Decl::IDNS_ObjCImplementation;
233 case Sema::LookupObjCCategoryImplName:
234 IDNS = Decl::IDNS_ObjCCategoryImpl;
240 // Necessary because CXXBasePaths is not complete in Sema.h
241 void LookupResult::deletePaths(CXXBasePaths *Paths) {
245 /// Resolves the result kind of this lookup.
246 void LookupResult::resolveKind() {
247 unsigned N = Decls.size();
249 // Fast case: no possible ambiguity.
251 assert(ResultKind == NotFound);
255 // If there's a single decl, we need to examine it to decide what
256 // kind of lookup this is.
258 if (isa<FunctionTemplateDecl>(Decls[0]))
259 ResultKind = FoundOverloaded;
260 else if (isa<UnresolvedUsingValueDecl>(Decls[0]))
261 ResultKind = FoundUnresolvedValue;
265 // Don't do any extra resolution if we've already resolved as ambiguous.
266 if (ResultKind == Ambiguous) return;
268 llvm::SmallPtrSet<NamedDecl*, 16> Unique;
270 bool Ambiguous = false;
271 bool HasTag = false, HasFunction = false, HasNonFunction = false;
272 bool HasFunctionTemplate = false, HasUnresolved = false;
274 unsigned UniqueTagIndex = 0;
278 NamedDecl *D = Decls[I]->getUnderlyingDecl();
279 D = cast<NamedDecl>(D->getCanonicalDecl());
281 if (!Unique.insert(D)) {
282 // If it's not unique, pull something off the back (and
283 // continue at this index).
284 Decls[I] = Decls[--N];
285 } else if (isa<UnresolvedUsingValueDecl>(D)) {
286 // FIXME: support unresolved using value declarations
287 Decls[I] = Decls[--N];
289 // Otherwise, do some decl type analysis and then continue.
291 if (isa<UnresolvedUsingValueDecl>(D)) {
292 HasUnresolved = true;
293 } else if (isa<TagDecl>(D)) {
298 } else if (isa<FunctionTemplateDecl>(D)) {
300 HasFunctionTemplate = true;
301 } else if (isa<FunctionDecl>(D)) {
306 HasNonFunction = true;
312 // C++ [basic.scope.hiding]p2:
313 // A class name or enumeration name can be hidden by the name of
314 // an object, function, or enumerator declared in the same
315 // scope. If a class or enumeration name and an object, function,
316 // or enumerator are declared in the same scope (in any order)
317 // with the same name, the class or enumeration name is hidden
318 // wherever the object, function, or enumerator name is visible.
319 // But it's still an error if there are distinct tag types found,
320 // even if they're not visible. (ref?)
321 if (HideTags && HasTag && !Ambiguous && !HasUnresolved &&
322 (HasFunction || HasNonFunction))
323 Decls[UniqueTagIndex] = Decls[--N];
327 if (HasFunction && HasNonFunction)
331 setAmbiguous(LookupResult::AmbiguousReference);
332 else if (HasUnresolved)
333 ResultKind = LookupResult::FoundUnresolvedValue;
334 else if (N > 1 || HasFunctionTemplate)
335 ResultKind = LookupResult::FoundOverloaded;
337 ResultKind = LookupResult::Found;
340 /// @brief Converts the result of name lookup into a single (possible
341 /// NULL) pointer to a declaration.
343 /// The resulting declaration will either be the declaration we found
344 /// (if only a single declaration was found), an
345 /// OverloadedFunctionDecl (if an overloaded function was found), or
346 /// NULL (if no declaration was found). This conversion must not be
347 /// used anywhere where name lookup could result in an ambiguity.
349 /// The OverloadedFunctionDecl conversion is meant as a stop-gap
350 /// solution, since it causes the OverloadedFunctionDecl to be
351 /// leaked. FIXME: Eventually, there will be a better way to iterate
352 /// over the set of overloaded functions returned by name lookup.
353 NamedDecl *LookupResult::getAsSingleDecl(ASTContext &C) const {
354 size_t size = Decls.size();
355 if (size == 0) return 0;
356 if (size == 1) return (*begin())->getUnderlyingDecl();
358 if (isAmbiguous()) return 0;
360 iterator I = begin(), E = end();
362 OverloadedFunctionDecl *Ovl
363 = OverloadedFunctionDecl::Create(C, (*I)->getDeclContext(),
364 (*I)->getDeclName());
365 for (; I != E; ++I) {
366 NamedDecl *ND = (*I)->getUnderlyingDecl();
367 assert(ND->isFunctionOrFunctionTemplate());
368 if (isa<FunctionDecl>(ND))
369 Ovl->addOverload(cast<FunctionDecl>(ND));
371 Ovl->addOverload(cast<FunctionTemplateDecl>(ND));
372 // FIXME: UnresolvedUsingDecls.
378 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
379 CXXBasePaths::paths_iterator I, E;
380 DeclContext::lookup_iterator DI, DE;
381 for (I = P.begin(), E = P.end(); I != E; ++I)
382 for (llvm::tie(DI,DE) = I->Decls; DI != DE; ++DI)
386 void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) {
387 Paths = new CXXBasePaths;
389 addDeclsFromBasePaths(*Paths);
391 setAmbiguous(AmbiguousBaseSubobjects);
394 void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) {
395 Paths = new CXXBasePaths;
397 addDeclsFromBasePaths(*Paths);
399 setAmbiguous(AmbiguousBaseSubobjectTypes);
402 void LookupResult::print(llvm::raw_ostream &Out) {
403 Out << Decls.size() << " result(s)";
404 if (isAmbiguous()) Out << ", ambiguous";
405 if (Paths) Out << ", base paths present";
407 for (iterator I = begin(), E = end(); I != E; ++I) {
413 // Adds all qualifying matches for a name within a decl context to the
414 // given lookup result. Returns true if any matches were found.
415 static bool LookupDirect(LookupResult &R, const DeclContext *DC) {
418 DeclContext::lookup_const_iterator I, E;
419 for (llvm::tie(I, E) = DC->lookup(R.getLookupName()); I != E; ++I)
420 if (Sema::isAcceptableLookupResult(*I, R.getLookupKind(),
421 R.getIdentifierNamespace()))
422 R.addDecl(*I), Found = true;
427 // Performs C++ unqualified lookup into the given file context.
429 CppNamespaceLookup(LookupResult &R, ASTContext &Context, DeclContext *NS,
430 UnqualUsingDirectiveSet &UDirs) {
432 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
434 // Perform direct name lookup into the LookupCtx.
435 bool Found = LookupDirect(R, NS);
437 // Perform direct name lookup into the namespaces nominated by the
438 // using directives whose common ancestor is this namespace.
439 UnqualUsingDirectiveSet::const_iterator UI, UEnd;
440 llvm::tie(UI, UEnd) = UDirs.getNamespacesFor(NS);
442 for (; UI != UEnd; ++UI)
443 if (LookupDirect(R, UI->getNominatedNamespace()))
451 static bool isNamespaceOrTranslationUnitScope(Scope *S) {
452 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity()))
453 return Ctx->isFileContext();
457 // Find the next outer declaration context corresponding to this scope.
458 static DeclContext *findOuterContext(Scope *S) {
459 for (S = S->getParent(); S; S = S->getParent())
461 return static_cast<DeclContext *>(S->getEntity())->getPrimaryContext();
466 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
467 assert(getLangOptions().CPlusPlus &&
468 "Can perform only C++ lookup");
469 LookupNameKind NameKind = R.getLookupKind();
471 = getIdentifierNamespacesFromLookupNameKind(NameKind, /*CPlusPlus*/ true);
473 // If we're testing for redeclarations, also look in the friend namespaces.
474 if (R.isForRedeclaration()) {
475 if (IDNS & Decl::IDNS_Tag) IDNS |= Decl::IDNS_TagFriend;
476 if (IDNS & Decl::IDNS_Ordinary) IDNS |= Decl::IDNS_OrdinaryFriend;
479 R.setIdentifierNamespace(IDNS);
481 DeclarationName Name = R.getLookupName();
484 IdentifierResolver::iterator
485 I = IdResolver.begin(Name),
486 IEnd = IdResolver.end();
488 // First we lookup local scope.
489 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
490 // ...During unqualified name lookup (3.4.1), the names appear as if
491 // they were declared in the nearest enclosing namespace which contains
492 // both the using-directive and the nominated namespace.
493 // [Note: in this context, "contains" means "contains directly or
497 // namespace A { int i; }
501 // using namespace A;
502 // ++i; // finds local 'i', A::i appears at global scope
506 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
507 // Check whether the IdResolver has anything in this scope.
509 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) {
510 if (isAcceptableLookupResult(*I, NameKind, IDNS)) {
520 if (DeclContext *Ctx = static_cast<DeclContext*>(S->getEntity())) {
521 DeclContext *OuterCtx = findOuterContext(S);
522 for (; Ctx && Ctx->getPrimaryContext() != OuterCtx;
523 Ctx = Ctx->getLookupParent()) {
524 if (Ctx->isFunctionOrMethod())
527 // Perform qualified name lookup into this context.
528 // FIXME: In some cases, we know that every name that could be found by
529 // this qualified name lookup will also be on the identifier chain. For
530 // example, inside a class without any base classes, we never need to
531 // perform qualified lookup because all of the members are on top of the
533 if (LookupQualifiedName(R, Ctx))
539 // Stop if we ran out of scopes.
540 // FIXME: This really, really shouldn't be happening.
541 if (!S) return false;
543 // Collect UsingDirectiveDecls in all scopes, and recursively all
544 // nominated namespaces by those using-directives.
546 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
547 // don't build it for each lookup!
549 UnqualUsingDirectiveSet UDirs;
550 UDirs.visitScopeChain(Initial, S);
553 // Lookup namespace scope, and global scope.
554 // Unqualified name lookup in C++ requires looking into scopes
555 // that aren't strictly lexical, and therefore we walk through the
556 // context as well as walking through the scopes.
558 for (; S; S = S->getParent()) {
559 DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity());
560 if (Ctx->isTransparentContext())
563 assert(Ctx && Ctx->isFileContext() &&
564 "We should have been looking only at file context here already.");
566 // Check whether the IdResolver has anything in this scope.
568 for (; I != IEnd && S->isDeclScope(DeclPtrTy::make(*I)); ++I) {
569 if (isAcceptableLookupResult(*I, NameKind, IDNS)) {
570 // We found something. Look for anything else in our scope
571 // with this same name and in an acceptable identifier
572 // namespace, so that we can construct an overload set if we
579 // Look into context considering using-directives.
580 if (CppNamespaceLookup(R, Context, Ctx, UDirs))
588 if (R.isForRedeclaration() && !Ctx->isTransparentContext())
595 /// @brief Perform unqualified name lookup starting from a given
598 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
599 /// used to find names within the current scope. For example, 'x' in
603 /// return x; // unqualified name look finds 'x' in the global scope
607 /// Different lookup criteria can find different names. For example, a
608 /// particular scope can have both a struct and a function of the same
609 /// name, and each can be found by certain lookup criteria. For more
610 /// information about lookup criteria, see the documentation for the
611 /// class LookupCriteria.
613 /// @param S The scope from which unqualified name lookup will
614 /// begin. If the lookup criteria permits, name lookup may also search
615 /// in the parent scopes.
617 /// @param Name The name of the entity that we are searching for.
619 /// @param Loc If provided, the source location where we're performing
620 /// name lookup. At present, this is only used to produce diagnostics when
621 /// C library functions (like "malloc") are implicitly declared.
623 /// @returns The result of name lookup, which includes zero or more
624 /// declarations and possibly additional information used to diagnose
626 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
627 DeclarationName Name = R.getLookupName();
628 if (!Name) return false;
630 LookupNameKind NameKind = R.getLookupKind();
632 if (!getLangOptions().CPlusPlus) {
633 // Unqualified name lookup in C/Objective-C is purely lexical, so
634 // search in the declarations attached to the name.
637 case Sema::LookupOrdinaryName:
638 IDNS = Decl::IDNS_Ordinary;
641 case Sema::LookupTagName:
642 IDNS = Decl::IDNS_Tag;
645 case Sema::LookupMemberName:
646 IDNS = Decl::IDNS_Member;
649 case Sema::LookupOperatorName:
650 case Sema::LookupNestedNameSpecifierName:
651 case Sema::LookupNamespaceName:
652 assert(false && "C does not perform these kinds of name lookup");
655 case Sema::LookupRedeclarationWithLinkage:
656 // Find the nearest non-transparent declaration scope.
657 while (!(S->getFlags() & Scope::DeclScope) ||
659 static_cast<DeclContext *>(S->getEntity())
660 ->isTransparentContext()))
662 IDNS = Decl::IDNS_Ordinary;
665 case Sema::LookupObjCProtocolName:
666 IDNS = Decl::IDNS_ObjCProtocol;
669 case Sema::LookupObjCImplementationName:
670 IDNS = Decl::IDNS_ObjCImplementation;
673 case Sema::LookupObjCCategoryImplName:
674 IDNS = Decl::IDNS_ObjCCategoryImpl;
678 // Scan up the scope chain looking for a decl that matches this
679 // identifier that is in the appropriate namespace. This search
680 // should not take long, as shadowing of names is uncommon, and
681 // deep shadowing is extremely uncommon.
682 bool LeftStartingScope = false;
684 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
685 IEnd = IdResolver.end();
687 if ((*I)->isInIdentifierNamespace(IDNS)) {
688 if (NameKind == LookupRedeclarationWithLinkage) {
689 // Determine whether this (or a previous) declaration is
691 if (!LeftStartingScope && !S->isDeclScope(DeclPtrTy::make(*I)))
692 LeftStartingScope = true;
694 // If we found something outside of our starting scope that
695 // does not have linkage, skip it.
696 if (LeftStartingScope && !((*I)->hasLinkage()))
702 if ((*I)->getAttr<OverloadableAttr>()) {
703 // If this declaration has the "overloadable" attribute, we
704 // might have a set of overloaded functions.
706 // Figure out what scope the identifier is in.
707 while (!(S->getFlags() & Scope::DeclScope) ||
708 !S->isDeclScope(DeclPtrTy::make(*I)))
711 // Find the last declaration in this scope (with the same
713 IdentifierResolver::iterator LastI = I;
714 for (++LastI; LastI != IEnd; ++LastI) {
715 if (!S->isDeclScope(DeclPtrTy::make(*LastI)))
726 // Perform C++ unqualified name lookup.
727 if (CppLookupName(R, S))
731 // If we didn't find a use of this identifier, and if the identifier
732 // corresponds to a compiler builtin, create the decl object for the builtin
733 // now, injecting it into translation unit scope, and return it.
734 if (NameKind == LookupOrdinaryName ||
735 NameKind == LookupRedeclarationWithLinkage) {
736 IdentifierInfo *II = Name.getAsIdentifierInfo();
737 if (II && AllowBuiltinCreation) {
738 // If this is a builtin on this (or all) targets, create the decl.
739 if (unsigned BuiltinID = II->getBuiltinID()) {
740 // In C++, we don't have any predefined library functions like
741 // 'malloc'. Instead, we'll just error.
742 if (getLangOptions().CPlusPlus &&
743 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
746 NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID,
747 S, R.isForRedeclaration(),
757 /// @brief Perform qualified name lookup in the namespaces nominated by
758 /// using directives by the given context.
760 /// C++98 [namespace.qual]p2:
761 /// Given X::m (where X is a user-declared namespace), or given ::m
762 /// (where X is the global namespace), let S be the set of all
763 /// declarations of m in X and in the transitive closure of all
764 /// namespaces nominated by using-directives in X and its used
765 /// namespaces, except that using-directives are ignored in any
766 /// namespace, including X, directly containing one or more
767 /// declarations of m. No namespace is searched more than once in
768 /// the lookup of a name. If S is the empty set, the program is
769 /// ill-formed. Otherwise, if S has exactly one member, or if the
770 /// context of the reference is a using-declaration
771 /// (namespace.udecl), S is the required set of declarations of
772 /// m. Otherwise if the use of m is not one that allows a unique
773 /// declaration to be chosen from S, the program is ill-formed.
774 /// C++98 [namespace.qual]p5:
775 /// During the lookup of a qualified namespace member name, if the
776 /// lookup finds more than one declaration of the member, and if one
777 /// declaration introduces a class name or enumeration name and the
778 /// other declarations either introduce the same object, the same
779 /// enumerator or a set of functions, the non-type name hides the
780 /// class or enumeration name if and only if the declarations are
781 /// from the same namespace; otherwise (the declarations are from
782 /// different namespaces), the program is ill-formed.
783 static bool LookupQualifiedNameInUsingDirectives(LookupResult &R,
784 DeclContext *StartDC) {
785 assert(StartDC->isFileContext() && "start context is not a file context");
787 DeclContext::udir_iterator I = StartDC->using_directives_begin();
788 DeclContext::udir_iterator E = StartDC->using_directives_end();
790 if (I == E) return false;
792 // We have at least added all these contexts to the queue.
793 llvm::DenseSet<DeclContext*> Visited;
794 Visited.insert(StartDC);
796 // We have not yet looked into these namespaces, much less added
797 // their "using-children" to the queue.
798 llvm::SmallVector<NamespaceDecl*, 8> Queue;
800 // We have already looked into the initial namespace; seed the queue
801 // with its using-children.
802 for (; I != E; ++I) {
803 NamespaceDecl *ND = (*I)->getNominatedNamespace()->getOriginalNamespace();
804 if (Visited.insert(ND).second)
808 // The easiest way to implement the restriction in [namespace.qual]p5
809 // is to check whether any of the individual results found a tag
810 // and, if so, to declare an ambiguity if the final result is not
812 bool FoundTag = false;
813 bool FoundNonTag = false;
815 LookupResult LocalR(LookupResult::Temporary, R);
818 while (!Queue.empty()) {
819 NamespaceDecl *ND = Queue.back();
822 // We go through some convolutions here to avoid copying results
823 // between LookupResults.
824 bool UseLocal = !R.empty();
825 LookupResult &DirectR = UseLocal ? LocalR : R;
826 bool FoundDirect = LookupDirect(DirectR, ND);
829 // First do any local hiding.
830 DirectR.resolveKind();
832 // If the local result is a tag, remember that.
833 if (DirectR.isSingleTagDecl())
838 // Append the local results to the total results if necessary.
840 R.addAllDecls(LocalR);
845 // If we find names in this namespace, ignore its using directives.
851 for (llvm::tie(I,E) = ND->getUsingDirectives(); I != E; ++I) {
852 NamespaceDecl *Nom = (*I)->getNominatedNamespace();
853 if (Visited.insert(Nom).second)
854 Queue.push_back(Nom);
859 if (FoundTag && FoundNonTag)
860 R.setAmbiguousQualifiedTagHiding();
868 /// @brief Perform qualified name lookup into a given context.
870 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
871 /// names when the context of those names is explicit specified, e.g.,
872 /// "std::vector" or "x->member".
874 /// Different lookup criteria can find different names. For example, a
875 /// particular scope can have both a struct and a function of the same
876 /// name, and each can be found by certain lookup criteria. For more
877 /// information about lookup criteria, see the documentation for the
878 /// class LookupCriteria.
880 /// @param LookupCtx The context in which qualified name lookup will
881 /// search. If the lookup criteria permits, name lookup may also search
882 /// in the parent contexts or (for C++ classes) base classes.
884 /// @param Name The name of the entity that we are searching for.
886 /// @param Criteria The criteria that this routine will use to
887 /// determine which names are visible and which names will be
888 /// found. Note that name lookup will find a name that is visible by
889 /// the given criteria, but the entity itself may not be semantically
890 /// correct or even the kind of entity expected based on the
891 /// lookup. For example, searching for a nested-name-specifier name
892 /// might result in an EnumDecl, which is visible but is not permitted
893 /// as a nested-name-specifier in C++03.
895 /// @returns The result of name lookup, which includes zero or more
896 /// declarations and possibly additional information used to diagnose
898 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx) {
899 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
901 if (!R.getLookupName())
904 // If we're performing qualified name lookup (e.g., lookup into a
905 // struct), find fields as part of ordinary name lookup.
906 LookupNameKind NameKind = R.getLookupKind();
908 = getIdentifierNamespacesFromLookupNameKind(NameKind,
909 getLangOptions().CPlusPlus);
910 if (NameKind == LookupOrdinaryName)
911 IDNS |= Decl::IDNS_Member;
913 R.setIdentifierNamespace(IDNS);
915 // Make sure that the declaration context is complete.
916 assert((!isa<TagDecl>(LookupCtx) ||
917 LookupCtx->isDependentContext() ||
918 cast<TagDecl>(LookupCtx)->isDefinition() ||
919 Context.getTypeDeclType(cast<TagDecl>(LookupCtx))->getAs<TagType>()
920 ->isBeingDefined()) &&
921 "Declaration context must already be complete!");
923 // Perform qualified name lookup into the LookupCtx.
924 if (LookupDirect(R, LookupCtx)) {
929 // Don't descend into implied contexts for redeclarations.
930 // C++98 [namespace.qual]p6:
931 // In a declaration for a namespace member in which the
932 // declarator-id is a qualified-id, given that the qualified-id
933 // for the namespace member has the form
934 // nested-name-specifier unqualified-id
935 // the unqualified-id shall name a member of the namespace
936 // designated by the nested-name-specifier.
937 // See also [class.mfct]p5 and [class.static.data]p2.
938 if (R.isForRedeclaration())
941 // If this is a namespace, look it up in the implied namespaces.
942 if (LookupCtx->isFileContext())
943 return LookupQualifiedNameInUsingDirectives(R, LookupCtx);
945 // If this isn't a C++ class, we aren't allowed to look into base
946 // classes, we're done.
947 if (!isa<CXXRecordDecl>(LookupCtx))
950 // Perform lookup into our base classes.
951 CXXRecordDecl *LookupRec = cast<CXXRecordDecl>(LookupCtx);
953 Paths.setOrigin(LookupRec);
955 // Look for this member in our base classes
956 CXXRecordDecl::BaseMatchesCallback *BaseCallback = 0;
957 switch (R.getLookupKind()) {
958 case LookupOrdinaryName:
959 case LookupMemberName:
960 case LookupRedeclarationWithLinkage:
961 BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
965 BaseCallback = &CXXRecordDecl::FindTagMember;
968 case LookupOperatorName:
969 case LookupNamespaceName:
970 case LookupObjCProtocolName:
971 case LookupObjCImplementationName:
972 case LookupObjCCategoryImplName:
973 // These lookups will never find a member in a C++ class (or base class).
976 case LookupNestedNameSpecifierName:
977 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember;
981 if (!LookupRec->lookupInBases(BaseCallback,
982 R.getLookupName().getAsOpaquePtr(), Paths))
985 // C++ [class.member.lookup]p2:
986 // [...] If the resulting set of declarations are not all from
987 // sub-objects of the same type, or the set has a nonstatic member
988 // and includes members from distinct sub-objects, there is an
989 // ambiguity and the program is ill-formed. Otherwise that set is
990 // the result of the lookup.
991 // FIXME: support using declarations!
992 QualType SubobjectType;
993 int SubobjectNumber = 0;
994 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
995 Path != PathEnd; ++Path) {
996 const CXXBasePathElement &PathElement = Path->back();
998 // Determine whether we're looking at a distinct sub-object or not.
999 if (SubobjectType.isNull()) {
1000 // This is the first subobject we've looked at. Record its type.
1001 SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
1002 SubobjectNumber = PathElement.SubobjectNumber;
1003 } else if (SubobjectType
1004 != Context.getCanonicalType(PathElement.Base->getType())) {
1005 // We found members of the given name in two subobjects of
1006 // different types. This lookup is ambiguous.
1007 R.setAmbiguousBaseSubobjectTypes(Paths);
1009 } else if (SubobjectNumber != PathElement.SubobjectNumber) {
1010 // We have a different subobject of the same type.
1012 // C++ [class.member.lookup]p5:
1013 // A static member, a nested type or an enumerator defined in
1014 // a base class T can unambiguously be found even if an object
1015 // has more than one base class subobject of type T.
1016 Decl *FirstDecl = *Path->Decls.first;
1017 if (isa<VarDecl>(FirstDecl) ||
1018 isa<TypeDecl>(FirstDecl) ||
1019 isa<EnumConstantDecl>(FirstDecl))
1022 if (isa<CXXMethodDecl>(FirstDecl)) {
1023 // Determine whether all of the methods are static.
1024 bool AllMethodsAreStatic = true;
1025 for (DeclContext::lookup_iterator Func = Path->Decls.first;
1026 Func != Path->Decls.second; ++Func) {
1027 if (!isa<CXXMethodDecl>(*Func)) {
1028 assert(isa<TagDecl>(*Func) && "Non-function must be a tag decl");
1032 if (!cast<CXXMethodDecl>(*Func)->isStatic()) {
1033 AllMethodsAreStatic = false;
1038 if (AllMethodsAreStatic)
1042 // We have found a nonstatic member name in multiple, distinct
1043 // subobjects. Name lookup is ambiguous.
1044 R.setAmbiguousBaseSubobjects(Paths);
1049 // Lookup in a base class succeeded; return these results.
1051 DeclContext::lookup_iterator I, E;
1052 for (llvm::tie(I,E) = Paths.front().Decls; I != E; ++I)
1058 /// @brief Performs name lookup for a name that was parsed in the
1059 /// source code, and may contain a C++ scope specifier.
1061 /// This routine is a convenience routine meant to be called from
1062 /// contexts that receive a name and an optional C++ scope specifier
1063 /// (e.g., "N::M::x"). It will then perform either qualified or
1064 /// unqualified name lookup (with LookupQualifiedName or LookupName,
1065 /// respectively) on the given name and return those results.
1067 /// @param S The scope from which unqualified name lookup will
1070 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
1072 /// @param Name The name of the entity that name lookup will
1075 /// @param Loc If provided, the source location where we're performing
1076 /// name lookup. At present, this is only used to produce diagnostics when
1077 /// C library functions (like "malloc") are implicitly declared.
1079 /// @param EnteringContext Indicates whether we are going to enter the
1080 /// context of the scope-specifier SS (if present).
1082 /// @returns True if any decls were found (but possibly ambiguous)
1083 bool Sema::LookupParsedName(LookupResult &R, Scope *S, const CXXScopeSpec *SS,
1084 bool AllowBuiltinCreation, bool EnteringContext) {
1085 if (SS && SS->isInvalid()) {
1086 // When the scope specifier is invalid, don't even look for
1091 if (SS && SS->isSet()) {
1092 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
1093 // We have resolved the scope specifier to a particular declaration
1094 // contex, and will perform name lookup in that context.
1095 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS))
1098 R.setContextRange(SS->getRange());
1100 return LookupQualifiedName(R, DC);
1103 // We could not resolve the scope specified to a specific declaration
1104 // context, which means that SS refers to an unknown specialization.
1105 // Name lookup can't find anything in this case.
1109 // Perform unqualified name lookup starting in the given scope.
1110 return LookupName(R, S, AllowBuiltinCreation);
1114 /// @brief Produce a diagnostic describing the ambiguity that resulted
1115 /// from name lookup.
1117 /// @param Result The ambiguous name lookup result.
1119 /// @param Name The name of the entity that name lookup was
1122 /// @param NameLoc The location of the name within the source code.
1124 /// @param LookupRange A source range that provides more
1125 /// source-location information concerning the lookup itself. For
1126 /// example, this range might highlight a nested-name-specifier that
1127 /// precedes the name.
1130 bool Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
1131 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
1133 DeclarationName Name = Result.getLookupName();
1134 SourceLocation NameLoc = Result.getNameLoc();
1135 SourceRange LookupRange = Result.getContextRange();
1137 switch (Result.getAmbiguityKind()) {
1138 case LookupResult::AmbiguousBaseSubobjects: {
1139 CXXBasePaths *Paths = Result.getBasePaths();
1140 QualType SubobjectType = Paths->front().back().Base->getType();
1141 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
1142 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
1145 DeclContext::lookup_iterator Found = Paths->front().Decls.first;
1146 while (isa<CXXMethodDecl>(*Found) &&
1147 cast<CXXMethodDecl>(*Found)->isStatic())
1150 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
1155 case LookupResult::AmbiguousBaseSubobjectTypes: {
1156 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
1157 << Name << LookupRange;
1159 CXXBasePaths *Paths = Result.getBasePaths();
1160 std::set<Decl *> DeclsPrinted;
1161 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
1162 PathEnd = Paths->end();
1163 Path != PathEnd; ++Path) {
1164 Decl *D = *Path->Decls.first;
1165 if (DeclsPrinted.insert(D).second)
1166 Diag(D->getLocation(), diag::note_ambiguous_member_found);
1172 case LookupResult::AmbiguousTagHiding: {
1173 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
1175 llvm::SmallPtrSet<NamedDecl*,8> TagDecls;
1177 LookupResult::iterator DI, DE = Result.end();
1178 for (DI = Result.begin(); DI != DE; ++DI)
1179 if (TagDecl *TD = dyn_cast<TagDecl>(*DI)) {
1180 TagDecls.insert(TD);
1181 Diag(TD->getLocation(), diag::note_hidden_tag);
1184 for (DI = Result.begin(); DI != DE; ++DI)
1185 if (!isa<TagDecl>(*DI))
1186 Diag((*DI)->getLocation(), diag::note_hiding_object);
1188 // For recovery purposes, go ahead and implement the hiding.
1189 Result.hideDecls(TagDecls);
1194 case LookupResult::AmbiguousReference: {
1195 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
1197 LookupResult::iterator DI = Result.begin(), DE = Result.end();
1198 for (; DI != DE; ++DI)
1199 Diag((*DI)->getLocation(), diag::note_ambiguous_candidate) << *DI;
1205 llvm::llvm_unreachable("unknown ambiguity kind");
1210 addAssociatedClassesAndNamespaces(QualType T,
1211 ASTContext &Context,
1212 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1213 Sema::AssociatedClassSet &AssociatedClasses);
1215 static void CollectNamespace(Sema::AssociatedNamespaceSet &Namespaces,
1217 if (Ctx->isFileContext())
1218 Namespaces.insert(Ctx);
1221 // \brief Add the associated classes and namespaces for argument-dependent
1222 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2).
1224 addAssociatedClassesAndNamespaces(const TemplateArgument &Arg,
1225 ASTContext &Context,
1226 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1227 Sema::AssociatedClassSet &AssociatedClasses) {
1228 // C++ [basic.lookup.koenig]p2, last bullet:
1230 switch (Arg.getKind()) {
1231 case TemplateArgument::Null:
1234 case TemplateArgument::Type:
1235 // [...] the namespaces and classes associated with the types of the
1236 // template arguments provided for template type parameters (excluding
1237 // template template parameters)
1238 addAssociatedClassesAndNamespaces(Arg.getAsType(), Context,
1239 AssociatedNamespaces,
1243 case TemplateArgument::Template: {
1244 // [...] the namespaces in which any template template arguments are
1245 // defined; and the classes in which any member templates used as
1246 // template template arguments are defined.
1247 TemplateName Template = Arg.getAsTemplate();
1248 if (ClassTemplateDecl *ClassTemplate
1249 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
1250 DeclContext *Ctx = ClassTemplate->getDeclContext();
1251 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1252 AssociatedClasses.insert(EnclosingClass);
1253 // Add the associated namespace for this class.
1254 while (Ctx->isRecord())
1255 Ctx = Ctx->getParent();
1256 CollectNamespace(AssociatedNamespaces, Ctx);
1261 case TemplateArgument::Declaration:
1262 case TemplateArgument::Integral:
1263 case TemplateArgument::Expression:
1264 // [Note: non-type template arguments do not contribute to the set of
1265 // associated namespaces. ]
1268 case TemplateArgument::Pack:
1269 for (TemplateArgument::pack_iterator P = Arg.pack_begin(),
1270 PEnd = Arg.pack_end();
1272 addAssociatedClassesAndNamespaces(*P, Context,
1273 AssociatedNamespaces,
1279 // \brief Add the associated classes and namespaces for
1280 // argument-dependent lookup with an argument of class type
1281 // (C++ [basic.lookup.koenig]p2).
1283 addAssociatedClassesAndNamespaces(CXXRecordDecl *Class,
1284 ASTContext &Context,
1285 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1286 Sema::AssociatedClassSet &AssociatedClasses) {
1287 // C++ [basic.lookup.koenig]p2:
1289 // -- If T is a class type (including unions), its associated
1290 // classes are: the class itself; the class of which it is a
1291 // member, if any; and its direct and indirect base
1292 // classes. Its associated namespaces are the namespaces in
1293 // which its associated classes are defined.
1295 // Add the class of which it is a member, if any.
1296 DeclContext *Ctx = Class->getDeclContext();
1297 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1298 AssociatedClasses.insert(EnclosingClass);
1299 // Add the associated namespace for this class.
1300 while (Ctx->isRecord())
1301 Ctx = Ctx->getParent();
1302 CollectNamespace(AssociatedNamespaces, Ctx);
1304 // Add the class itself. If we've already seen this class, we don't
1305 // need to visit base classes.
1306 if (!AssociatedClasses.insert(Class))
1309 // -- If T is a template-id, its associated namespaces and classes are
1310 // the namespace in which the template is defined; for member
1311 // templates, the member template’s class; the namespaces and classes
1312 // associated with the types of the template arguments provided for
1313 // template type parameters (excluding template template parameters); the
1314 // namespaces in which any template template arguments are defined; and
1315 // the classes in which any member templates used as template template
1316 // arguments are defined. [Note: non-type template arguments do not
1317 // contribute to the set of associated namespaces. ]
1318 if (ClassTemplateSpecializationDecl *Spec
1319 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
1320 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
1321 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1322 AssociatedClasses.insert(EnclosingClass);
1323 // Add the associated namespace for this class.
1324 while (Ctx->isRecord())
1325 Ctx = Ctx->getParent();
1326 CollectNamespace(AssociatedNamespaces, Ctx);
1328 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
1329 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
1330 addAssociatedClassesAndNamespaces(TemplateArgs[I], Context,
1331 AssociatedNamespaces,
1335 // Add direct and indirect base classes along with their associated
1337 llvm::SmallVector<CXXRecordDecl *, 32> Bases;
1338 Bases.push_back(Class);
1339 while (!Bases.empty()) {
1340 // Pop this class off the stack.
1341 Class = Bases.back();
1344 // Visit the base classes.
1345 for (CXXRecordDecl::base_class_iterator Base = Class->bases_begin(),
1346 BaseEnd = Class->bases_end();
1347 Base != BaseEnd; ++Base) {
1348 const RecordType *BaseType = Base->getType()->getAs<RecordType>();
1349 // In dependent contexts, we do ADL twice, and the first time around,
1350 // the base type might be a dependent TemplateSpecializationType, or a
1351 // TemplateTypeParmType. If that happens, simply ignore it.
1352 // FIXME: If we want to support export, we probably need to add the
1353 // namespace of the template in a TemplateSpecializationType, or even
1354 // the classes and namespaces of known non-dependent arguments.
1357 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
1358 if (AssociatedClasses.insert(BaseDecl)) {
1359 // Find the associated namespace for this base class.
1360 DeclContext *BaseCtx = BaseDecl->getDeclContext();
1361 while (BaseCtx->isRecord())
1362 BaseCtx = BaseCtx->getParent();
1363 CollectNamespace(AssociatedNamespaces, BaseCtx);
1365 // Make sure we visit the bases of this base class.
1366 if (BaseDecl->bases_begin() != BaseDecl->bases_end())
1367 Bases.push_back(BaseDecl);
1373 // \brief Add the associated classes and namespaces for
1374 // argument-dependent lookup with an argument of type T
1375 // (C++ [basic.lookup.koenig]p2).
1377 addAssociatedClassesAndNamespaces(QualType T,
1378 ASTContext &Context,
1379 Sema::AssociatedNamespaceSet &AssociatedNamespaces,
1380 Sema::AssociatedClassSet &AssociatedClasses) {
1381 // C++ [basic.lookup.koenig]p2:
1383 // For each argument type T in the function call, there is a set
1384 // of zero or more associated namespaces and a set of zero or more
1385 // associated classes to be considered. The sets of namespaces and
1386 // classes is determined entirely by the types of the function
1387 // arguments (and the namespace of any template template
1388 // argument). Typedef names and using-declarations used to specify
1389 // the types do not contribute to this set. The sets of namespaces
1390 // and classes are determined in the following way:
1391 T = Context.getCanonicalType(T).getUnqualifiedType();
1393 // -- If T is a pointer to U or an array of U, its associated
1394 // namespaces and classes are those associated with U.
1396 // We handle this by unwrapping pointer and array types immediately,
1397 // to avoid unnecessary recursion.
1399 if (const PointerType *Ptr = T->getAs<PointerType>())
1400 T = Ptr->getPointeeType();
1401 else if (const ArrayType *Ptr = Context.getAsArrayType(T))
1402 T = Ptr->getElementType();
1407 // -- If T is a fundamental type, its associated sets of
1408 // namespaces and classes are both empty.
1409 if (T->getAs<BuiltinType>())
1412 // -- If T is a class type (including unions), its associated
1413 // classes are: the class itself; the class of which it is a
1414 // member, if any; and its direct and indirect base
1415 // classes. Its associated namespaces are the namespaces in
1416 // which its associated classes are defined.
1417 if (const RecordType *ClassType = T->getAs<RecordType>())
1418 if (CXXRecordDecl *ClassDecl
1419 = dyn_cast<CXXRecordDecl>(ClassType->getDecl())) {
1420 addAssociatedClassesAndNamespaces(ClassDecl, Context,
1421 AssociatedNamespaces,
1426 // -- If T is an enumeration type, its associated namespace is
1427 // the namespace in which it is defined. If it is class
1428 // member, its associated class is the member’s class; else
1429 // it has no associated class.
1430 if (const EnumType *EnumT = T->getAs<EnumType>()) {
1431 EnumDecl *Enum = EnumT->getDecl();
1433 DeclContext *Ctx = Enum->getDeclContext();
1434 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
1435 AssociatedClasses.insert(EnclosingClass);
1437 // Add the associated namespace for this class.
1438 while (Ctx->isRecord())
1439 Ctx = Ctx->getParent();
1440 CollectNamespace(AssociatedNamespaces, Ctx);
1445 // -- If T is a function type, its associated namespaces and
1446 // classes are those associated with the function parameter
1447 // types and those associated with the return type.
1448 if (const FunctionType *FnType = T->getAs<FunctionType>()) {
1450 addAssociatedClassesAndNamespaces(FnType->getResultType(),
1452 AssociatedNamespaces, AssociatedClasses);
1454 const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FnType);
1459 for (FunctionProtoType::arg_type_iterator Arg = Proto->arg_type_begin(),
1460 ArgEnd = Proto->arg_type_end();
1461 Arg != ArgEnd; ++Arg)
1462 addAssociatedClassesAndNamespaces(*Arg, Context,
1463 AssociatedNamespaces, AssociatedClasses);
1468 // -- If T is a pointer to a member function of a class X, its
1469 // associated namespaces and classes are those associated
1470 // with the function parameter types and return type,
1471 // together with those associated with X.
1473 // -- If T is a pointer to a data member of class X, its
1474 // associated namespaces and classes are those associated
1475 // with the member type together with those associated with
1477 if (const MemberPointerType *MemberPtr = T->getAs<MemberPointerType>()) {
1478 // Handle the type that the pointer to member points to.
1479 addAssociatedClassesAndNamespaces(MemberPtr->getPointeeType(),
1481 AssociatedNamespaces,
1484 // Handle the class type into which this points.
1485 if (const RecordType *Class = MemberPtr->getClass()->getAs<RecordType>())
1486 addAssociatedClassesAndNamespaces(cast<CXXRecordDecl>(Class->getDecl()),
1488 AssociatedNamespaces,
1494 // FIXME: What about block pointers?
1495 // FIXME: What about Objective-C message sends?
1498 /// \brief Find the associated classes and namespaces for
1499 /// argument-dependent lookup for a call with the given set of
1502 /// This routine computes the sets of associated classes and associated
1503 /// namespaces searched by argument-dependent lookup
1504 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
1506 Sema::FindAssociatedClassesAndNamespaces(Expr **Args, unsigned NumArgs,
1507 AssociatedNamespaceSet &AssociatedNamespaces,
1508 AssociatedClassSet &AssociatedClasses) {
1509 AssociatedNamespaces.clear();
1510 AssociatedClasses.clear();
1512 // C++ [basic.lookup.koenig]p2:
1513 // For each argument type T in the function call, there is a set
1514 // of zero or more associated namespaces and a set of zero or more
1515 // associated classes to be considered. The sets of namespaces and
1516 // classes is determined entirely by the types of the function
1517 // arguments (and the namespace of any template template
1519 for (unsigned ArgIdx = 0; ArgIdx != NumArgs; ++ArgIdx) {
1520 Expr *Arg = Args[ArgIdx];
1522 if (Arg->getType() != Context.OverloadTy) {
1523 addAssociatedClassesAndNamespaces(Arg->getType(), Context,
1524 AssociatedNamespaces,
1529 // [...] In addition, if the argument is the name or address of a
1530 // set of overloaded functions and/or function templates, its
1531 // associated classes and namespaces are the union of those
1532 // associated with each of the members of the set: the namespace
1533 // in which the function or function template is defined and the
1534 // classes and namespaces associated with its (non-dependent)
1535 // parameter types and return type.
1536 Arg = Arg->IgnoreParens();
1537 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg))
1538 if (unaryOp->getOpcode() == UnaryOperator::AddrOf)
1539 Arg = unaryOp->getSubExpr();
1541 // TODO: avoid the copies. This should be easy when the cases
1542 // share a storage implementation.
1543 llvm::SmallVector<NamedDecl*, 8> Functions;
1545 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg))
1546 Functions.append(ULE->decls_begin(), ULE->decls_end());
1550 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Functions.begin(),
1551 E = Functions.end(); I != E; ++I) {
1552 FunctionDecl *FDecl = dyn_cast<FunctionDecl>(*I);
1554 FDecl = cast<FunctionTemplateDecl>(*I)->getTemplatedDecl();
1556 // Add the namespace in which this function was defined. Note
1557 // that, if this is a member function, we do *not* consider the
1558 // enclosing namespace of its class.
1559 DeclContext *Ctx = FDecl->getDeclContext();
1560 CollectNamespace(AssociatedNamespaces, Ctx);
1562 // Add the classes and namespaces associated with the parameter
1563 // types and return type of this function.
1564 addAssociatedClassesAndNamespaces(FDecl->getType(), Context,
1565 AssociatedNamespaces,
1571 /// IsAcceptableNonMemberOperatorCandidate - Determine whether Fn is
1572 /// an acceptable non-member overloaded operator for a call whose
1573 /// arguments have types T1 (and, if non-empty, T2). This routine
1574 /// implements the check in C++ [over.match.oper]p3b2 concerning
1575 /// enumeration types.
1577 IsAcceptableNonMemberOperatorCandidate(FunctionDecl *Fn,
1578 QualType T1, QualType T2,
1579 ASTContext &Context) {
1580 if (T1->isDependentType() || (!T2.isNull() && T2->isDependentType()))
1583 if (T1->isRecordType() || (!T2.isNull() && T2->isRecordType()))
1586 const FunctionProtoType *Proto = Fn->getType()->getAs<FunctionProtoType>();
1587 if (Proto->getNumArgs() < 1)
1590 if (T1->isEnumeralType()) {
1591 QualType ArgType = Proto->getArgType(0).getNonReferenceType();
1592 if (Context.hasSameUnqualifiedType(T1, ArgType))
1596 if (Proto->getNumArgs() < 2)
1599 if (!T2.isNull() && T2->isEnumeralType()) {
1600 QualType ArgType = Proto->getArgType(1).getNonReferenceType();
1601 if (Context.hasSameUnqualifiedType(T2, ArgType))
1608 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
1609 LookupNameKind NameKind,
1610 RedeclarationKind Redecl) {
1611 LookupResult R(*this, Name, SourceLocation(), NameKind, Redecl);
1613 return R.getAsSingleDecl(Context);
1616 /// \brief Find the protocol with the given name, if any.
1617 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II) {
1618 Decl *D = LookupSingleName(TUScope, II, LookupObjCProtocolName);
1619 return cast_or_null<ObjCProtocolDecl>(D);
1622 /// \brief Find the Objective-C category implementation with the given
1624 ObjCCategoryImplDecl *Sema::LookupObjCCategoryImpl(IdentifierInfo *II) {
1625 Decl *D = LookupSingleName(TUScope, II, LookupObjCCategoryImplName);
1626 return cast_or_null<ObjCCategoryImplDecl>(D);
1629 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
1630 QualType T1, QualType T2,
1631 FunctionSet &Functions) {
1632 // C++ [over.match.oper]p3:
1633 // -- The set of non-member candidates is the result of the
1634 // unqualified lookup of operator@ in the context of the
1635 // expression according to the usual rules for name lookup in
1636 // unqualified function calls (3.4.2) except that all member
1637 // functions are ignored. However, if no operand has a class
1638 // type, only those non-member functions in the lookup set
1639 // that have a first parameter of type T1 or "reference to
1640 // (possibly cv-qualified) T1", when T1 is an enumeration
1641 // type, or (if there is a right operand) a second parameter
1642 // of type T2 or "reference to (possibly cv-qualified) T2",
1643 // when T2 is an enumeration type, are candidate functions.
1644 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
1645 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
1646 LookupName(Operators, S);
1648 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
1650 if (Operators.empty())
1653 for (LookupResult::iterator Op = Operators.begin(), OpEnd = Operators.end();
1654 Op != OpEnd; ++Op) {
1655 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Op)) {
1656 if (IsAcceptableNonMemberOperatorCandidate(FD, T1, T2, Context))
1657 Functions.insert(FD); // FIXME: canonical FD
1658 } else if (FunctionTemplateDecl *FunTmpl
1659 = dyn_cast<FunctionTemplateDecl>(*Op)) {
1660 // FIXME: friend operators?
1661 // FIXME: do we need to check IsAcceptableNonMemberOperatorCandidate,
1663 if (!FunTmpl->getDeclContext()->isRecord())
1664 Functions.insert(FunTmpl);
1669 static void CollectFunctionDecl(Sema::FunctionSet &Functions,
1671 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(D))
1672 Functions.insert(Func);
1673 else if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D))
1674 Functions.insert(FunTmpl);
1677 void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator,
1678 Expr **Args, unsigned NumArgs,
1679 FunctionSet &Functions) {
1680 // Find all of the associated namespaces and classes based on the
1681 // arguments we have.
1682 AssociatedNamespaceSet AssociatedNamespaces;
1683 AssociatedClassSet AssociatedClasses;
1684 FindAssociatedClassesAndNamespaces(Args, NumArgs,
1685 AssociatedNamespaces,
1690 T1 = Args[0]->getType();
1692 T2 = Args[1]->getType();
1695 // C++ [basic.lookup.argdep]p3:
1696 // Let X be the lookup set produced by unqualified lookup (3.4.1)
1697 // and let Y be the lookup set produced by argument dependent
1698 // lookup (defined as follows). If X contains [...] then Y is
1699 // empty. Otherwise Y is the set of declarations found in the
1700 // namespaces associated with the argument types as described
1701 // below. The set of declarations found by the lookup of the name
1702 // is the union of X and Y.
1704 // Here, we compute Y and add its members to the overloaded
1706 for (AssociatedNamespaceSet::iterator NS = AssociatedNamespaces.begin(),
1707 NSEnd = AssociatedNamespaces.end();
1708 NS != NSEnd; ++NS) {
1709 // When considering an associated namespace, the lookup is the
1710 // same as the lookup performed when the associated namespace is
1711 // used as a qualifier (3.4.3.2) except that:
1713 // -- Any using-directives in the associated namespace are
1716 // -- Any namespace-scope friend functions declared in
1717 // associated classes are visible within their respective
1718 // namespaces even if they are not visible during an ordinary
1720 DeclContext::lookup_iterator I, E;
1721 for (llvm::tie(I, E) = (*NS)->lookup(Name); I != E; ++I) {
1723 // If the only declaration here is an ordinary friend, consider
1724 // it only if it was declared in an associated classes.
1725 if (D->getIdentifierNamespace() == Decl::IDNS_OrdinaryFriend) {
1726 DeclContext *LexDC = D->getLexicalDeclContext();
1727 if (!AssociatedClasses.count(cast<CXXRecordDecl>(LexDC)))
1732 if (!Operator || !(Fn = dyn_cast<FunctionDecl>(D)) ||
1733 IsAcceptableNonMemberOperatorCandidate(Fn, T1, T2, Context))
1734 CollectFunctionDecl(Functions, D);