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 //===----------------------------------------------------------------------===//
15 #include "clang/Sema/Lookup.h"
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/ASTMutationListener.h"
18 #include "clang/AST/CXXInheritance.h"
19 #include "clang/AST/Decl.h"
20 #include "clang/AST/DeclCXX.h"
21 #include "clang/AST/DeclLookups.h"
22 #include "clang/AST/DeclObjC.h"
23 #include "clang/AST/DeclTemplate.h"
24 #include "clang/AST/Expr.h"
25 #include "clang/AST/ExprCXX.h"
26 #include "clang/Basic/Builtins.h"
27 #include "clang/Basic/LangOptions.h"
28 #include "clang/Lex/HeaderSearch.h"
29 #include "clang/Lex/ModuleLoader.h"
30 #include "clang/Lex/Preprocessor.h"
31 #include "clang/Sema/DeclSpec.h"
32 #include "clang/Sema/ExternalSemaSource.h"
33 #include "clang/Sema/Overload.h"
34 #include "clang/Sema/Scope.h"
35 #include "clang/Sema/ScopeInfo.h"
36 #include "clang/Sema/Sema.h"
37 #include "clang/Sema/SemaInternal.h"
38 #include "clang/Sema/TemplateDeduction.h"
39 #include "clang/Sema/TypoCorrection.h"
40 #include "llvm/ADT/STLExtras.h"
41 #include "llvm/ADT/SetVector.h"
42 #include "llvm/ADT/SmallPtrSet.h"
43 #include "llvm/ADT/StringMap.h"
44 #include "llvm/ADT/TinyPtrVector.h"
45 #include "llvm/ADT/edit_distance.h"
46 #include "llvm/Support/ErrorHandling.h"
56 using namespace clang;
60 class UnqualUsingEntry {
61 const DeclContext *Nominated;
62 const DeclContext *CommonAncestor;
65 UnqualUsingEntry(const DeclContext *Nominated,
66 const DeclContext *CommonAncestor)
67 : Nominated(Nominated), CommonAncestor(CommonAncestor) {
70 const DeclContext *getCommonAncestor() const {
71 return CommonAncestor;
74 const DeclContext *getNominatedNamespace() const {
78 // Sort by the pointer value of the common ancestor.
80 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) {
81 return L.getCommonAncestor() < R.getCommonAncestor();
84 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) {
85 return E.getCommonAncestor() < DC;
88 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) {
89 return DC < E.getCommonAncestor();
94 /// A collection of using directives, as used by C++ unqualified
96 class UnqualUsingDirectiveSet {
97 typedef SmallVector<UnqualUsingEntry, 8> ListTy;
100 llvm::SmallPtrSet<DeclContext*, 8> visited;
103 UnqualUsingDirectiveSet() {}
105 void visitScopeChain(Scope *S, Scope *InnermostFileScope) {
106 // C++ [namespace.udir]p1:
107 // During unqualified name lookup, the names appear as if they
108 // were declared in the nearest enclosing namespace which contains
109 // both the using-directive and the nominated namespace.
110 DeclContext *InnermostFileDC = InnermostFileScope->getEntity();
111 assert(InnermostFileDC && InnermostFileDC->isFileContext());
113 for (; S; S = S->getParent()) {
114 // C++ [namespace.udir]p1:
115 // A using-directive shall not appear in class scope, but may
116 // appear in namespace scope or in block scope.
117 DeclContext *Ctx = S->getEntity();
118 if (Ctx && Ctx->isFileContext()) {
120 } else if (!Ctx || Ctx->isFunctionOrMethod()) {
121 for (auto *I : S->using_directives())
122 visit(I, InnermostFileDC);
127 // Visits a context and collect all of its using directives
128 // recursively. Treats all using directives as if they were
129 // declared in the context.
131 // A given context is only every visited once, so it is important
132 // that contexts be visited from the inside out in order to get
133 // the effective DCs right.
134 void visit(DeclContext *DC, DeclContext *EffectiveDC) {
135 if (!visited.insert(DC).second)
138 addUsingDirectives(DC, EffectiveDC);
141 // Visits a using directive and collects all of its using
142 // directives recursively. Treats all using directives as if they
143 // were declared in the effective DC.
144 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
145 DeclContext *NS = UD->getNominatedNamespace();
146 if (!visited.insert(NS).second)
149 addUsingDirective(UD, EffectiveDC);
150 addUsingDirectives(NS, EffectiveDC);
153 // Adds all the using directives in a context (and those nominated
154 // by its using directives, transitively) as if they appeared in
155 // the given effective context.
156 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) {
157 SmallVector<DeclContext*, 4> queue;
159 for (auto UD : DC->using_directives()) {
160 DeclContext *NS = UD->getNominatedNamespace();
161 if (visited.insert(NS).second) {
162 addUsingDirective(UD, EffectiveDC);
170 DC = queue.pop_back_val();
174 // Add a using directive as if it had been declared in the given
175 // context. This helps implement C++ [namespace.udir]p3:
176 // The using-directive is transitive: if a scope contains a
177 // using-directive that nominates a second namespace that itself
178 // contains using-directives, the effect is as if the
179 // using-directives from the second namespace also appeared in
181 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
182 // Find the common ancestor between the effective context and
183 // the nominated namespace.
184 DeclContext *Common = UD->getNominatedNamespace();
185 while (!Common->Encloses(EffectiveDC))
186 Common = Common->getParent();
187 Common = Common->getPrimaryContext();
189 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common));
193 std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator());
196 typedef ListTy::const_iterator const_iterator;
198 const_iterator begin() const { return list.begin(); }
199 const_iterator end() const { return list.end(); }
201 llvm::iterator_range<const_iterator>
202 getNamespacesFor(DeclContext *DC) const {
203 return llvm::make_range(std::equal_range(begin(), end(),
204 DC->getPrimaryContext(),
205 UnqualUsingEntry::Comparator()));
208 } // end anonymous namespace
210 // Retrieve the set of identifier namespaces that correspond to a
211 // specific kind of name lookup.
212 static inline unsigned getIDNS(Sema::LookupNameKind NameKind,
214 bool Redeclaration) {
217 case Sema::LookupObjCImplicitSelfParam:
218 case Sema::LookupOrdinaryName:
219 case Sema::LookupRedeclarationWithLinkage:
220 case Sema::LookupLocalFriendName:
221 IDNS = Decl::IDNS_Ordinary;
223 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace;
225 IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend;
228 IDNS |= Decl::IDNS_LocalExtern;
231 case Sema::LookupOperatorName:
232 // Operator lookup is its own crazy thing; it is not the same
233 // as (e.g.) looking up an operator name for redeclaration.
234 assert(!Redeclaration && "cannot do redeclaration operator lookup");
235 IDNS = Decl::IDNS_NonMemberOperator;
238 case Sema::LookupTagName:
240 IDNS = Decl::IDNS_Type;
242 // When looking for a redeclaration of a tag name, we add:
243 // 1) TagFriend to find undeclared friend decls
244 // 2) Namespace because they can't "overload" with tag decls.
245 // 3) Tag because it includes class templates, which can't
246 // "overload" with tag decls.
248 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace;
250 IDNS = Decl::IDNS_Tag;
254 case Sema::LookupLabel:
255 IDNS = Decl::IDNS_Label;
258 case Sema::LookupMemberName:
259 IDNS = Decl::IDNS_Member;
261 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary;
264 case Sema::LookupNestedNameSpecifierName:
265 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace;
268 case Sema::LookupNamespaceName:
269 IDNS = Decl::IDNS_Namespace;
272 case Sema::LookupUsingDeclName:
273 assert(Redeclaration && "should only be used for redecl lookup");
274 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member |
275 Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend |
276 Decl::IDNS_LocalExtern;
279 case Sema::LookupObjCProtocolName:
280 IDNS = Decl::IDNS_ObjCProtocol;
283 case Sema::LookupAnyName:
284 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member
285 | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol
292 void LookupResult::configure() {
293 IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus,
294 isForRedeclaration());
296 // If we're looking for one of the allocation or deallocation
297 // operators, make sure that the implicitly-declared new and delete
298 // operators can be found.
299 switch (NameInfo.getName().getCXXOverloadedOperator()) {
303 case OO_Array_Delete:
304 getSema().DeclareGlobalNewDelete();
311 // Compiler builtins are always visible, regardless of where they end
312 // up being declared.
313 if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) {
314 if (unsigned BuiltinID = Id->getBuiltinID()) {
315 if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
321 bool LookupResult::sanity() const {
322 // This function is never called by NDEBUG builds.
323 assert(ResultKind != NotFound || Decls.size() == 0);
324 assert(ResultKind != Found || Decls.size() == 1);
325 assert(ResultKind != FoundOverloaded || Decls.size() > 1 ||
326 (Decls.size() == 1 &&
327 isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl())));
328 assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved());
329 assert(ResultKind != Ambiguous || Decls.size() > 1 ||
330 (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects ||
331 Ambiguity == AmbiguousBaseSubobjectTypes)));
332 assert((Paths != nullptr) == (ResultKind == Ambiguous &&
333 (Ambiguity == AmbiguousBaseSubobjectTypes ||
334 Ambiguity == AmbiguousBaseSubobjects)));
338 // Necessary because CXXBasePaths is not complete in Sema.h
339 void LookupResult::deletePaths(CXXBasePaths *Paths) {
343 /// Get a representative context for a declaration such that two declarations
344 /// will have the same context if they were found within the same scope.
345 static DeclContext *getContextForScopeMatching(Decl *D) {
346 // For function-local declarations, use that function as the context. This
347 // doesn't account for scopes within the function; the caller must deal with
349 DeclContext *DC = D->getLexicalDeclContext();
350 if (DC->isFunctionOrMethod())
353 // Otherwise, look at the semantic context of the declaration. The
354 // declaration must have been found there.
355 return D->getDeclContext()->getRedeclContext();
358 /// \brief Determine whether \p D is a better lookup result than \p Existing,
359 /// given that they declare the same entity.
360 static bool isPreferredLookupResult(Sema &S, Sema::LookupNameKind Kind,
361 NamedDecl *D, NamedDecl *Existing) {
362 // When looking up redeclarations of a using declaration, prefer a using
363 // shadow declaration over any other declaration of the same entity.
364 if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(D) &&
365 !isa<UsingShadowDecl>(Existing))
368 auto *DUnderlying = D->getUnderlyingDecl();
369 auto *EUnderlying = Existing->getUnderlyingDecl();
371 // If they have different underlying declarations, prefer a typedef over the
372 // original type (this happens when two type declarations denote the same
373 // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef
374 // might carry additional semantic information, such as an alignment override.
375 // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag
376 // declaration over a typedef.
377 if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) {
378 assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying));
379 bool HaveTag = isa<TagDecl>(EUnderlying);
380 bool WantTag = Kind == Sema::LookupTagName;
381 return HaveTag != WantTag;
384 // Pick the function with more default arguments.
385 // FIXME: In the presence of ambiguous default arguments, we should keep both,
386 // so we can diagnose the ambiguity if the default argument is needed.
387 // See C++ [over.match.best]p3.
388 if (auto *DFD = dyn_cast<FunctionDecl>(DUnderlying)) {
389 auto *EFD = cast<FunctionDecl>(EUnderlying);
390 unsigned DMin = DFD->getMinRequiredArguments();
391 unsigned EMin = EFD->getMinRequiredArguments();
392 // If D has more default arguments, it is preferred.
395 // FIXME: When we track visibility for default function arguments, check
396 // that we pick the declaration with more visible default arguments.
399 // Pick the template with more default template arguments.
400 if (auto *DTD = dyn_cast<TemplateDecl>(DUnderlying)) {
401 auto *ETD = cast<TemplateDecl>(EUnderlying);
402 unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments();
403 unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments();
404 // If D has more default arguments, it is preferred. Note that default
405 // arguments (and their visibility) is monotonically increasing across the
406 // redeclaration chain, so this is a quick proxy for "is more recent".
409 // If D has more *visible* default arguments, it is preferred. Note, an
410 // earlier default argument being visible does not imply that a later
411 // default argument is visible, so we can't just check the first one.
412 for (unsigned I = DMin, N = DTD->getTemplateParameters()->size();
414 if (!S.hasVisibleDefaultArgument(
415 ETD->getTemplateParameters()->getParam(I)) &&
416 S.hasVisibleDefaultArgument(
417 DTD->getTemplateParameters()->getParam(I)))
422 // For most kinds of declaration, it doesn't really matter which one we pick.
423 if (!isa<FunctionDecl>(DUnderlying) && !isa<VarDecl>(DUnderlying)) {
424 // If the existing declaration is hidden, prefer the new one. Otherwise,
425 // keep what we've got.
426 return !S.isVisible(Existing);
429 // Pick the newer declaration; it might have a more precise type.
430 for (Decl *Prev = DUnderlying->getPreviousDecl(); Prev;
431 Prev = Prev->getPreviousDecl())
432 if (Prev == EUnderlying)
436 // If the existing declaration is hidden, prefer the new one. Otherwise,
437 // keep what we've got.
438 return !S.isVisible(Existing);
441 /// Determine whether \p D can hide a tag declaration.
442 static bool canHideTag(NamedDecl *D) {
443 // C++ [basic.scope.declarative]p4:
444 // Given a set of declarations in a single declarative region [...]
445 // exactly one declaration shall declare a class name or enumeration name
446 // that is not a typedef name and the other declarations shall all refer to
447 // the same variable or enumerator, or all refer to functions and function
448 // templates; in this case the class name or enumeration name is hidden.
449 // C++ [basic.scope.hiding]p2:
450 // A class name or enumeration name can be hidden by the name of a
451 // variable, data member, function, or enumerator declared in the same
453 D = D->getUnderlyingDecl();
454 return isa<VarDecl>(D) || isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D) ||
455 isa<FunctionTemplateDecl>(D) || isa<FieldDecl>(D);
458 /// Resolves the result kind of this lookup.
459 void LookupResult::resolveKind() {
460 unsigned N = Decls.size();
462 // Fast case: no possible ambiguity.
464 assert(ResultKind == NotFound ||
465 ResultKind == NotFoundInCurrentInstantiation);
469 // If there's a single decl, we need to examine it to decide what
470 // kind of lookup this is.
472 NamedDecl *D = (*Decls.begin())->getUnderlyingDecl();
473 if (isa<FunctionTemplateDecl>(D))
474 ResultKind = FoundOverloaded;
475 else if (isa<UnresolvedUsingValueDecl>(D))
476 ResultKind = FoundUnresolvedValue;
480 // Don't do any extra resolution if we've already resolved as ambiguous.
481 if (ResultKind == Ambiguous) return;
483 llvm::SmallDenseMap<NamedDecl*, unsigned, 16> Unique;
484 llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes;
486 bool Ambiguous = false;
487 bool HasTag = false, HasFunction = false;
488 bool HasFunctionTemplate = false, HasUnresolved = false;
489 NamedDecl *HasNonFunction = nullptr;
491 llvm::SmallVector<NamedDecl*, 4> EquivalentNonFunctions;
493 unsigned UniqueTagIndex = 0;
497 NamedDecl *D = Decls[I]->getUnderlyingDecl();
498 D = cast<NamedDecl>(D->getCanonicalDecl());
500 // Ignore an invalid declaration unless it's the only one left.
501 if (D->isInvalidDecl() && !(I == 0 && N == 1)) {
502 Decls[I] = Decls[--N];
506 llvm::Optional<unsigned> ExistingI;
508 // Redeclarations of types via typedef can occur both within a scope
509 // and, through using declarations and directives, across scopes. There is
510 // no ambiguity if they all refer to the same type, so unique based on the
512 if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) {
513 QualType T = getSema().Context.getTypeDeclType(TD);
514 auto UniqueResult = UniqueTypes.insert(
515 std::make_pair(getSema().Context.getCanonicalType(T), I));
516 if (!UniqueResult.second) {
517 // The type is not unique.
518 ExistingI = UniqueResult.first->second;
522 // For non-type declarations, check for a prior lookup result naming this
523 // canonical declaration.
525 auto UniqueResult = Unique.insert(std::make_pair(D, I));
526 if (!UniqueResult.second) {
527 // We've seen this entity before.
528 ExistingI = UniqueResult.first->second;
533 // This is not a unique lookup result. Pick one of the results and
534 // discard the other.
535 if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I],
537 Decls[*ExistingI] = Decls[I];
538 Decls[I] = Decls[--N];
542 // Otherwise, do some decl type analysis and then continue.
544 if (isa<UnresolvedUsingValueDecl>(D)) {
545 HasUnresolved = true;
546 } else if (isa<TagDecl>(D)) {
551 } else if (isa<FunctionTemplateDecl>(D)) {
553 HasFunctionTemplate = true;
554 } else if (isa<FunctionDecl>(D)) {
557 if (HasNonFunction) {
558 // If we're about to create an ambiguity between two declarations that
559 // are equivalent, but one is an internal linkage declaration from one
560 // module and the other is an internal linkage declaration from another
561 // module, just skip it.
562 if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction,
564 EquivalentNonFunctions.push_back(D);
565 Decls[I] = Decls[--N];
576 // C++ [basic.scope.hiding]p2:
577 // A class name or enumeration name can be hidden by the name of
578 // an object, function, or enumerator declared in the same
579 // scope. If a class or enumeration name and an object, function,
580 // or enumerator are declared in the same scope (in any order)
581 // with the same name, the class or enumeration name is hidden
582 // wherever the object, function, or enumerator name is visible.
583 // But it's still an error if there are distinct tag types found,
584 // even if they're not visible. (ref?)
585 if (N > 1 && HideTags && HasTag && !Ambiguous &&
586 (HasFunction || HasNonFunction || HasUnresolved)) {
587 NamedDecl *OtherDecl = Decls[UniqueTagIndex ? 0 : N - 1];
588 if (isa<TagDecl>(Decls[UniqueTagIndex]->getUnderlyingDecl()) &&
589 getContextForScopeMatching(Decls[UniqueTagIndex])->Equals(
590 getContextForScopeMatching(OtherDecl)) &&
591 canHideTag(OtherDecl))
592 Decls[UniqueTagIndex] = Decls[--N];
597 // FIXME: This diagnostic should really be delayed until we're done with
598 // the lookup result, in case the ambiguity is resolved by the caller.
599 if (!EquivalentNonFunctions.empty() && !Ambiguous)
600 getSema().diagnoseEquivalentInternalLinkageDeclarations(
601 getNameLoc(), HasNonFunction, EquivalentNonFunctions);
605 if (HasNonFunction && (HasFunction || HasUnresolved))
609 setAmbiguous(LookupResult::AmbiguousReference);
610 else if (HasUnresolved)
611 ResultKind = LookupResult::FoundUnresolvedValue;
612 else if (N > 1 || HasFunctionTemplate)
613 ResultKind = LookupResult::FoundOverloaded;
615 ResultKind = LookupResult::Found;
618 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
619 CXXBasePaths::const_paths_iterator I, E;
620 for (I = P.begin(), E = P.end(); I != E; ++I)
621 for (DeclContext::lookup_iterator DI = I->Decls.begin(),
622 DE = I->Decls.end(); DI != DE; ++DI)
626 void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) {
627 Paths = new CXXBasePaths;
629 addDeclsFromBasePaths(*Paths);
631 setAmbiguous(AmbiguousBaseSubobjects);
634 void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) {
635 Paths = new CXXBasePaths;
637 addDeclsFromBasePaths(*Paths);
639 setAmbiguous(AmbiguousBaseSubobjectTypes);
642 void LookupResult::print(raw_ostream &Out) {
643 Out << Decls.size() << " result(s)";
644 if (isAmbiguous()) Out << ", ambiguous";
645 if (Paths) Out << ", base paths present";
647 for (iterator I = begin(), E = end(); I != E; ++I) {
653 LLVM_DUMP_METHOD void LookupResult::dump() {
654 llvm::errs() << "lookup results for " << getLookupName().getAsString()
656 for (NamedDecl *D : *this)
660 /// \brief Lookup a builtin function, when name lookup would otherwise
662 static bool LookupBuiltin(Sema &S, LookupResult &R) {
663 Sema::LookupNameKind NameKind = R.getLookupKind();
665 // If we didn't find a use of this identifier, and if the identifier
666 // corresponds to a compiler builtin, create the decl object for the builtin
667 // now, injecting it into translation unit scope, and return it.
668 if (NameKind == Sema::LookupOrdinaryName ||
669 NameKind == Sema::LookupRedeclarationWithLinkage) {
670 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo();
672 if (S.getLangOpts().CPlusPlus11 && S.getLangOpts().GNUMode &&
673 II == S.getFloat128Identifier()) {
674 // libstdc++4.7's type_traits expects type __float128 to exist, so
675 // insert a dummy type to make that header build in gnu++11 mode.
676 R.addDecl(S.getASTContext().getFloat128StubType());
679 if (S.getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName &&
680 II == S.getASTContext().getMakeIntegerSeqName()) {
681 R.addDecl(S.getASTContext().getMakeIntegerSeqDecl());
685 // If this is a builtin on this (or all) targets, create the decl.
686 if (unsigned BuiltinID = II->getBuiltinID()) {
687 // In C++, we don't have any predefined library functions like
688 // 'malloc'. Instead, we'll just error.
689 if (S.getLangOpts().CPlusPlus &&
690 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
693 if (NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II,
694 BuiltinID, S.TUScope,
695 R.isForRedeclaration(),
707 /// \brief Determine whether we can declare a special member function within
708 /// the class at this point.
709 static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) {
710 // We need to have a definition for the class.
711 if (!Class->getDefinition() || Class->isDependentContext())
714 // We can't be in the middle of defining the class.
715 return !Class->isBeingDefined();
718 void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) {
719 if (!CanDeclareSpecialMemberFunction(Class))
722 // If the default constructor has not yet been declared, do so now.
723 if (Class->needsImplicitDefaultConstructor())
724 DeclareImplicitDefaultConstructor(Class);
726 // If the copy constructor has not yet been declared, do so now.
727 if (Class->needsImplicitCopyConstructor())
728 DeclareImplicitCopyConstructor(Class);
730 // If the copy assignment operator has not yet been declared, do so now.
731 if (Class->needsImplicitCopyAssignment())
732 DeclareImplicitCopyAssignment(Class);
734 if (getLangOpts().CPlusPlus11) {
735 // If the move constructor has not yet been declared, do so now.
736 if (Class->needsImplicitMoveConstructor())
737 DeclareImplicitMoveConstructor(Class); // might not actually do it
739 // If the move assignment operator has not yet been declared, do so now.
740 if (Class->needsImplicitMoveAssignment())
741 DeclareImplicitMoveAssignment(Class); // might not actually do it
744 // If the destructor has not yet been declared, do so now.
745 if (Class->needsImplicitDestructor())
746 DeclareImplicitDestructor(Class);
749 /// \brief Determine whether this is the name of an implicitly-declared
750 /// special member function.
751 static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) {
752 switch (Name.getNameKind()) {
753 case DeclarationName::CXXConstructorName:
754 case DeclarationName::CXXDestructorName:
757 case DeclarationName::CXXOperatorName:
758 return Name.getCXXOverloadedOperator() == OO_Equal;
767 /// \brief If there are any implicit member functions with the given name
768 /// that need to be declared in the given declaration context, do so.
769 static void DeclareImplicitMemberFunctionsWithName(Sema &S,
770 DeclarationName Name,
771 const DeclContext *DC) {
775 switch (Name.getNameKind()) {
776 case DeclarationName::CXXConstructorName:
777 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
778 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
779 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
780 if (Record->needsImplicitDefaultConstructor())
781 S.DeclareImplicitDefaultConstructor(Class);
782 if (Record->needsImplicitCopyConstructor())
783 S.DeclareImplicitCopyConstructor(Class);
784 if (S.getLangOpts().CPlusPlus11 &&
785 Record->needsImplicitMoveConstructor())
786 S.DeclareImplicitMoveConstructor(Class);
790 case DeclarationName::CXXDestructorName:
791 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
792 if (Record->getDefinition() && Record->needsImplicitDestructor() &&
793 CanDeclareSpecialMemberFunction(Record))
794 S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record));
797 case DeclarationName::CXXOperatorName:
798 if (Name.getCXXOverloadedOperator() != OO_Equal)
801 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) {
802 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
803 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
804 if (Record->needsImplicitCopyAssignment())
805 S.DeclareImplicitCopyAssignment(Class);
806 if (S.getLangOpts().CPlusPlus11 &&
807 Record->needsImplicitMoveAssignment())
808 S.DeclareImplicitMoveAssignment(Class);
818 // Adds all qualifying matches for a name within a decl context to the
819 // given lookup result. Returns true if any matches were found.
820 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
823 // Lazily declare C++ special member functions.
824 if (S.getLangOpts().CPlusPlus)
825 DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), DC);
827 // Perform lookup into this declaration context.
828 DeclContext::lookup_result DR = DC->lookup(R.getLookupName());
829 for (DeclContext::lookup_iterator I = DR.begin(), E = DR.end(); I != E;
832 if ((D = R.getAcceptableDecl(D))) {
838 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R))
841 if (R.getLookupName().getNameKind()
842 != DeclarationName::CXXConversionFunctionName ||
843 R.getLookupName().getCXXNameType()->isDependentType() ||
844 !isa<CXXRecordDecl>(DC))
848 // A specialization of a conversion function template is not found by
849 // name lookup. Instead, any conversion function templates visible in the
850 // context of the use are considered. [...]
851 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
852 if (!Record->isCompleteDefinition())
855 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(),
856 UEnd = Record->conversion_end(); U != UEnd; ++U) {
857 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
861 // When we're performing lookup for the purposes of redeclaration, just
862 // add the conversion function template. When we deduce template
863 // arguments for specializations, we'll end up unifying the return
864 // type of the new declaration with the type of the function template.
865 if (R.isForRedeclaration()) {
866 R.addDecl(ConvTemplate);
872 // [...] For each such operator, if argument deduction succeeds
873 // (14.9.2.3), the resulting specialization is used as if found by
876 // When referencing a conversion function for any purpose other than
877 // a redeclaration (such that we'll be building an expression with the
878 // result), perform template argument deduction and place the
879 // specialization into the result set. We do this to avoid forcing all
880 // callers to perform special deduction for conversion functions.
881 TemplateDeductionInfo Info(R.getNameLoc());
882 FunctionDecl *Specialization = nullptr;
884 const FunctionProtoType *ConvProto
885 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
886 assert(ConvProto && "Nonsensical conversion function template type");
888 // Compute the type of the function that we would expect the conversion
889 // function to have, if it were to match the name given.
890 // FIXME: Calling convention!
891 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo();
892 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C);
893 EPI.ExceptionSpec = EST_None;
894 QualType ExpectedType
895 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(),
898 // Perform template argument deduction against the type that we would
899 // expect the function to have.
900 if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType,
901 Specialization, Info)
902 == Sema::TDK_Success) {
903 R.addDecl(Specialization);
911 // Performs C++ unqualified lookup into the given file context.
913 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context,
914 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
916 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
918 // Perform direct name lookup into the LookupCtx.
919 bool Found = LookupDirect(S, R, NS);
921 // Perform direct name lookup into the namespaces nominated by the
922 // using directives whose common ancestor is this namespace.
923 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS))
924 if (LookupDirect(S, R, UUE.getNominatedNamespace()))
932 static bool isNamespaceOrTranslationUnitScope(Scope *S) {
933 if (DeclContext *Ctx = S->getEntity())
934 return Ctx->isFileContext();
938 // Find the next outer declaration context from this scope. This
939 // routine actually returns the semantic outer context, which may
940 // differ from the lexical context (encoded directly in the Scope
941 // stack) when we are parsing a member of a class template. In this
942 // case, the second element of the pair will be true, to indicate that
943 // name lookup should continue searching in this semantic context when
944 // it leaves the current template parameter scope.
945 static std::pair<DeclContext *, bool> findOuterContext(Scope *S) {
946 DeclContext *DC = S->getEntity();
947 DeclContext *Lexical = nullptr;
948 for (Scope *OuterS = S->getParent(); OuterS;
949 OuterS = OuterS->getParent()) {
950 if (OuterS->getEntity()) {
951 Lexical = OuterS->getEntity();
956 // C++ [temp.local]p8:
957 // In the definition of a member of a class template that appears
958 // outside of the namespace containing the class template
959 // definition, the name of a template-parameter hides the name of
960 // a member of this namespace.
967 // template<class T> class B {
972 // template<class C> void N::B<C>::f(C) {
973 // C b; // C is the template parameter, not N::C
976 // In this example, the lexical context we return is the
977 // TranslationUnit, while the semantic context is the namespace N.
978 if (!Lexical || !DC || !S->getParent() ||
979 !S->getParent()->isTemplateParamScope())
980 return std::make_pair(Lexical, false);
982 // Find the outermost template parameter scope.
983 // For the example, this is the scope for the template parameters of
984 // template<class C>.
985 Scope *OutermostTemplateScope = S->getParent();
986 while (OutermostTemplateScope->getParent() &&
987 OutermostTemplateScope->getParent()->isTemplateParamScope())
988 OutermostTemplateScope = OutermostTemplateScope->getParent();
990 // Find the namespace context in which the original scope occurs. In
991 // the example, this is namespace N.
992 DeclContext *Semantic = DC;
993 while (!Semantic->isFileContext())
994 Semantic = Semantic->getParent();
996 // Find the declaration context just outside of the template
997 // parameter scope. This is the context in which the template is
998 // being lexically declaration (a namespace context). In the
999 // example, this is the global scope.
1000 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) &&
1001 Lexical->Encloses(Semantic))
1002 return std::make_pair(Semantic, true);
1004 return std::make_pair(Lexical, false);
1008 /// An RAII object to specify that we want to find block scope extern
1010 struct FindLocalExternScope {
1011 FindLocalExternScope(LookupResult &R)
1012 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
1013 Decl::IDNS_LocalExtern) {
1014 R.setFindLocalExtern(R.getIdentifierNamespace() & Decl::IDNS_Ordinary);
1017 R.setFindLocalExtern(OldFindLocalExtern);
1019 ~FindLocalExternScope() {
1023 bool OldFindLocalExtern;
1025 } // end anonymous namespace
1027 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
1028 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
1030 DeclarationName Name = R.getLookupName();
1031 Sema::LookupNameKind NameKind = R.getLookupKind();
1033 // If this is the name of an implicitly-declared special member function,
1034 // go through the scope stack to implicitly declare
1035 if (isImplicitlyDeclaredMemberFunctionName(Name)) {
1036 for (Scope *PreS = S; PreS; PreS = PreS->getParent())
1037 if (DeclContext *DC = PreS->getEntity())
1038 DeclareImplicitMemberFunctionsWithName(*this, Name, DC);
1041 // Implicitly declare member functions with the name we're looking for, if in
1042 // fact we are in a scope where it matters.
1045 IdentifierResolver::iterator
1046 I = IdResolver.begin(Name),
1047 IEnd = IdResolver.end();
1049 // First we lookup local scope.
1050 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
1051 // ...During unqualified name lookup (3.4.1), the names appear as if
1052 // they were declared in the nearest enclosing namespace which contains
1053 // both the using-directive and the nominated namespace.
1054 // [Note: in this context, "contains" means "contains directly or
1058 // namespace A { int i; }
1062 // using namespace A;
1063 // ++i; // finds local 'i', A::i appears at global scope
1067 UnqualUsingDirectiveSet UDirs;
1068 bool VisitedUsingDirectives = false;
1069 bool LeftStartingScope = false;
1070 DeclContext *OutsideOfTemplateParamDC = nullptr;
1072 // When performing a scope lookup, we want to find local extern decls.
1073 FindLocalExternScope FindLocals(R);
1075 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
1076 DeclContext *Ctx = S->getEntity();
1078 // Check whether the IdResolver has anything in this scope.
1080 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1081 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1082 if (NameKind == LookupRedeclarationWithLinkage) {
1083 // Determine whether this (or a previous) declaration is
1085 if (!LeftStartingScope && !Initial->isDeclScope(*I))
1086 LeftStartingScope = true;
1088 // If we found something outside of our starting scope that
1089 // does not have linkage, skip it. If it's a template parameter,
1090 // we still find it, so we can diagnose the invalid redeclaration.
1091 if (LeftStartingScope && !((*I)->hasLinkage()) &&
1092 !(*I)->isTemplateParameter()) {
1104 if (S->isClassScope())
1105 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx))
1106 R.setNamingClass(Record);
1110 if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
1111 // C++11 [class.friend]p11:
1112 // If a friend declaration appears in a local class and the name
1113 // specified is an unqualified name, a prior declaration is
1114 // looked up without considering scopes that are outside the
1115 // innermost enclosing non-class scope.
1119 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1120 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1121 // We've just searched the last template parameter scope and
1122 // found nothing, so look into the contexts between the
1123 // lexical and semantic declaration contexts returned by
1124 // findOuterContext(). This implements the name lookup behavior
1125 // of C++ [temp.local]p8.
1126 Ctx = OutsideOfTemplateParamDC;
1127 OutsideOfTemplateParamDC = nullptr;
1131 DeclContext *OuterCtx;
1132 bool SearchAfterTemplateScope;
1133 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1134 if (SearchAfterTemplateScope)
1135 OutsideOfTemplateParamDC = OuterCtx;
1137 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1138 // We do not directly look into transparent contexts, since
1139 // those entities will be found in the nearest enclosing
1140 // non-transparent context.
1141 if (Ctx->isTransparentContext())
1144 // We do not look directly into function or method contexts,
1145 // since all of the local variables and parameters of the
1146 // function/method are present within the Scope.
1147 if (Ctx->isFunctionOrMethod()) {
1148 // If we have an Objective-C instance method, look for ivars
1149 // in the corresponding interface.
1150 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
1151 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
1152 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
1153 ObjCInterfaceDecl *ClassDeclared;
1154 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
1155 Name.getAsIdentifierInfo(),
1157 if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
1169 // If this is a file context, we need to perform unqualified name
1170 // lookup considering using directives.
1171 if (Ctx->isFileContext()) {
1172 // If we haven't handled using directives yet, do so now.
1173 if (!VisitedUsingDirectives) {
1174 // Add using directives from this context up to the top level.
1175 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
1176 if (UCtx->isTransparentContext())
1179 UDirs.visit(UCtx, UCtx);
1182 // Find the innermost file scope, so we can add using directives
1183 // from local scopes.
1184 Scope *InnermostFileScope = S;
1185 while (InnermostFileScope &&
1186 !isNamespaceOrTranslationUnitScope(InnermostFileScope))
1187 InnermostFileScope = InnermostFileScope->getParent();
1188 UDirs.visitScopeChain(Initial, InnermostFileScope);
1192 VisitedUsingDirectives = true;
1195 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
1203 // Perform qualified name lookup into this context.
1204 // FIXME: In some cases, we know that every name that could be found by
1205 // this qualified name lookup will also be on the identifier chain. For
1206 // example, inside a class without any base classes, we never need to
1207 // perform qualified lookup because all of the members are on top of the
1208 // identifier chain.
1209 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
1215 // Stop if we ran out of scopes.
1216 // FIXME: This really, really shouldn't be happening.
1217 if (!S) return false;
1219 // If we are looking for members, no need to look into global/namespace scope.
1220 if (NameKind == LookupMemberName)
1223 // Collect UsingDirectiveDecls in all scopes, and recursively all
1224 // nominated namespaces by those using-directives.
1226 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
1227 // don't build it for each lookup!
1228 if (!VisitedUsingDirectives) {
1229 UDirs.visitScopeChain(Initial, S);
1233 // If we're not performing redeclaration lookup, do not look for local
1234 // extern declarations outside of a function scope.
1235 if (!R.isForRedeclaration())
1236 FindLocals.restore();
1238 // Lookup namespace scope, and global scope.
1239 // Unqualified name lookup in C++ requires looking into scopes
1240 // that aren't strictly lexical, and therefore we walk through the
1241 // context as well as walking through the scopes.
1242 for (; S; S = S->getParent()) {
1243 // Check whether the IdResolver has anything in this scope.
1245 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1246 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1247 // We found something. Look for anything else in our scope
1248 // with this same name and in an acceptable identifier
1249 // namespace, so that we can construct an overload set if we
1256 if (Found && S->isTemplateParamScope()) {
1261 DeclContext *Ctx = S->getEntity();
1262 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1263 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1264 // We've just searched the last template parameter scope and
1265 // found nothing, so look into the contexts between the
1266 // lexical and semantic declaration contexts returned by
1267 // findOuterContext(). This implements the name lookup behavior
1268 // of C++ [temp.local]p8.
1269 Ctx = OutsideOfTemplateParamDC;
1270 OutsideOfTemplateParamDC = nullptr;
1274 DeclContext *OuterCtx;
1275 bool SearchAfterTemplateScope;
1276 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1277 if (SearchAfterTemplateScope)
1278 OutsideOfTemplateParamDC = OuterCtx;
1280 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1281 // We do not directly look into transparent contexts, since
1282 // those entities will be found in the nearest enclosing
1283 // non-transparent context.
1284 if (Ctx->isTransparentContext())
1287 // If we have a context, and it's not a context stashed in the
1288 // template parameter scope for an out-of-line definition, also
1289 // look into that context.
1290 if (!(Found && S && S->isTemplateParamScope())) {
1291 assert(Ctx->isFileContext() &&
1292 "We should have been looking only at file context here already.");
1294 // Look into context considering using-directives.
1295 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
1304 if (R.isForRedeclaration() && !Ctx->isTransparentContext())
1309 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
1316 /// \brief Find the declaration that a class temploid member specialization was
1317 /// instantiated from, or the member itself if it is an explicit specialization.
1318 static Decl *getInstantiatedFrom(Decl *D, MemberSpecializationInfo *MSInfo) {
1319 return MSInfo->isExplicitSpecialization() ? D : MSInfo->getInstantiatedFrom();
1322 Module *Sema::getOwningModule(Decl *Entity) {
1323 // If it's imported, grab its owning module.
1324 Module *M = Entity->getImportedOwningModule();
1325 if (M || !isa<NamedDecl>(Entity) || !cast<NamedDecl>(Entity)->isHidden())
1327 assert(!Entity->isFromASTFile() &&
1328 "hidden entity from AST file has no owning module");
1330 if (!getLangOpts().ModulesLocalVisibility) {
1331 // If we're not tracking visibility locally, the only way a declaration
1332 // can be hidden and local is if it's hidden because it's parent is (for
1333 // instance, maybe this is a lazily-declared special member of an imported
1335 auto *Parent = cast<NamedDecl>(Entity->getDeclContext());
1336 assert(Parent->isHidden() && "unexpectedly hidden decl");
1337 return getOwningModule(Parent);
1340 // It's local and hidden; grab or compute its owning module.
1341 M = Entity->getLocalOwningModule();
1345 if (auto *Containing =
1346 PP.getModuleContainingLocation(Entity->getLocation())) {
1348 } else if (Entity->isInvalidDecl() || Entity->getLocation().isInvalid()) {
1349 // Don't bother tracking visibility for invalid declarations with broken
1351 cast<NamedDecl>(Entity)->setHidden(false);
1353 // We need to assign a module to an entity that exists outside of any
1354 // module, so that we can hide it from modules that we textually enter.
1355 // Invent a fake module for all such entities.
1356 if (!CachedFakeTopLevelModule) {
1357 CachedFakeTopLevelModule =
1358 PP.getHeaderSearchInfo().getModuleMap().findOrCreateModule(
1359 "<top-level>", nullptr, false, false).first;
1361 auto &SrcMgr = PP.getSourceManager();
1362 SourceLocation StartLoc =
1363 SrcMgr.getLocForStartOfFile(SrcMgr.getMainFileID());
1365 VisibleModulesStack.empty() ? VisibleModules : VisibleModulesStack[0];
1366 TopLevel.setVisible(CachedFakeTopLevelModule, StartLoc);
1369 M = CachedFakeTopLevelModule;
1373 Entity->setLocalOwningModule(M);
1377 void Sema::makeMergedDefinitionVisible(NamedDecl *ND, SourceLocation Loc) {
1378 if (auto *M = PP.getModuleContainingLocation(Loc))
1379 Context.mergeDefinitionIntoModule(ND, M);
1381 // We're not building a module; just make the definition visible.
1382 ND->setHidden(false);
1384 // If ND is a template declaration, make the template parameters
1385 // visible too. They're not (necessarily) within a mergeable DeclContext.
1386 if (auto *TD = dyn_cast<TemplateDecl>(ND))
1387 for (auto *Param : *TD->getTemplateParameters())
1388 makeMergedDefinitionVisible(Param, Loc);
1391 /// \brief Find the module in which the given declaration was defined.
1392 static Module *getDefiningModule(Sema &S, Decl *Entity) {
1393 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
1394 // If this function was instantiated from a template, the defining module is
1395 // the module containing the pattern.
1396 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1398 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
1399 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1401 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
1402 if (MemberSpecializationInfo *MSInfo = ED->getMemberSpecializationInfo())
1403 Entity = getInstantiatedFrom(ED, MSInfo);
1404 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
1405 // FIXME: Map from variable template specializations back to the template.
1406 if (MemberSpecializationInfo *MSInfo = VD->getMemberSpecializationInfo())
1407 Entity = getInstantiatedFrom(VD, MSInfo);
1410 // Walk up to the containing context. That might also have been instantiated
1412 DeclContext *Context = Entity->getDeclContext();
1413 if (Context->isFileContext())
1414 return S.getOwningModule(Entity);
1415 return getDefiningModule(S, cast<Decl>(Context));
1418 llvm::DenseSet<Module*> &Sema::getLookupModules() {
1419 unsigned N = ActiveTemplateInstantiations.size();
1420 for (unsigned I = ActiveTemplateInstantiationLookupModules.size();
1423 getDefiningModule(*this, ActiveTemplateInstantiations[I].Entity);
1424 if (M && !LookupModulesCache.insert(M).second)
1426 ActiveTemplateInstantiationLookupModules.push_back(M);
1428 return LookupModulesCache;
1431 bool Sema::hasVisibleMergedDefinition(NamedDecl *Def) {
1432 for (Module *Merged : Context.getModulesWithMergedDefinition(Def))
1433 if (isModuleVisible(Merged))
1438 template<typename ParmDecl>
1440 hasVisibleDefaultArgument(Sema &S, const ParmDecl *D,
1441 llvm::SmallVectorImpl<Module *> *Modules) {
1442 if (!D->hasDefaultArgument())
1446 auto &DefaultArg = D->getDefaultArgStorage();
1447 if (!DefaultArg.isInherited() && S.isVisible(D))
1450 if (!DefaultArg.isInherited() && Modules) {
1451 auto *NonConstD = const_cast<ParmDecl*>(D);
1452 Modules->push_back(S.getOwningModule(NonConstD));
1453 const auto &Merged = S.Context.getModulesWithMergedDefinition(NonConstD);
1454 Modules->insert(Modules->end(), Merged.begin(), Merged.end());
1457 // If there was a previous default argument, maybe its parameter is visible.
1458 D = DefaultArg.getInheritedFrom();
1463 bool Sema::hasVisibleDefaultArgument(const NamedDecl *D,
1464 llvm::SmallVectorImpl<Module *> *Modules) {
1465 if (auto *P = dyn_cast<TemplateTypeParmDecl>(D))
1466 return ::hasVisibleDefaultArgument(*this, P, Modules);
1467 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D))
1468 return ::hasVisibleDefaultArgument(*this, P, Modules);
1469 return ::hasVisibleDefaultArgument(*this, cast<TemplateTemplateParmDecl>(D),
1473 /// \brief Determine whether a declaration is visible to name lookup.
1475 /// This routine determines whether the declaration D is visible in the current
1476 /// lookup context, taking into account the current template instantiation
1477 /// stack. During template instantiation, a declaration is visible if it is
1478 /// visible from a module containing any entity on the template instantiation
1479 /// path (by instantiating a template, you allow it to see the declarations that
1480 /// your module can see, including those later on in your module).
1481 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
1482 assert(D->isHidden() && "should not call this: not in slow case");
1483 Module *DeclModule = nullptr;
1485 if (SemaRef.getLangOpts().ModulesLocalVisibility) {
1486 DeclModule = SemaRef.getOwningModule(D);
1488 // getOwningModule() may have decided the declaration should not be hidden.
1489 assert(!D->isHidden() && "hidden decl not from a module");
1493 // If the owning module is visible, and the decl is not module private,
1494 // then the decl is visible too. (Module private is ignored within the same
1495 // top-level module.)
1496 if ((!D->isFromASTFile() || !D->isModulePrivate()) &&
1497 (SemaRef.isModuleVisible(DeclModule) ||
1498 SemaRef.hasVisibleMergedDefinition(D)))
1502 // If this declaration is not at namespace scope nor module-private,
1503 // then it is visible if its lexical parent has a visible definition.
1504 DeclContext *DC = D->getLexicalDeclContext();
1505 if (!D->isModulePrivate() &&
1506 DC && !DC->isFileContext() && !isa<LinkageSpecDecl>(DC)) {
1507 // For a parameter, check whether our current template declaration's
1508 // lexical context is visible, not whether there's some other visible
1509 // definition of it, because parameters aren't "within" the definition.
1510 if ((D->isTemplateParameter() || isa<ParmVarDecl>(D))
1511 ? isVisible(SemaRef, cast<NamedDecl>(DC))
1512 : SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC))) {
1513 if (SemaRef.ActiveTemplateInstantiations.empty() &&
1514 // FIXME: Do something better in this case.
1515 !SemaRef.getLangOpts().ModulesLocalVisibility) {
1516 // Cache the fact that this declaration is implicitly visible because
1517 // its parent has a visible definition.
1518 D->setHidden(false);
1525 // Find the extra places where we need to look.
1526 llvm::DenseSet<Module*> &LookupModules = SemaRef.getLookupModules();
1527 if (LookupModules.empty())
1531 DeclModule = SemaRef.getOwningModule(D);
1532 assert(DeclModule && "hidden decl not from a module");
1535 // If our lookup set contains the decl's module, it's visible.
1536 if (LookupModules.count(DeclModule))
1539 // If the declaration isn't exported, it's not visible in any other module.
1540 if (D->isModulePrivate())
1543 // Check whether DeclModule is transitively exported to an import of
1545 return std::any_of(LookupModules.begin(), LookupModules.end(),
1546 [&](Module *M) { return M->isModuleVisible(DeclModule); });
1549 bool Sema::isVisibleSlow(const NamedDecl *D) {
1550 return LookupResult::isVisible(*this, const_cast<NamedDecl*>(D));
1553 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
1558 return New->isExternallyVisible();
1561 /// \brief Retrieve the visible declaration corresponding to D, if any.
1563 /// This routine determines whether the declaration D is visible in the current
1564 /// module, with the current imports. If not, it checks whether any
1565 /// redeclaration of D is visible, and if so, returns that declaration.
1567 /// \returns D, or a visible previous declaration of D, whichever is more recent
1568 /// and visible. If no declaration of D is visible, returns null.
1569 static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D) {
1570 assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case");
1572 for (auto RD : D->redecls()) {
1573 if (auto ND = dyn_cast<NamedDecl>(RD)) {
1574 // FIXME: This is wrong in the case where the previous declaration is not
1575 // visible in the same scope as D. This needs to be done much more
1577 if (LookupResult::isVisible(SemaRef, ND))
1585 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
1586 return findAcceptableDecl(getSema(), D);
1589 /// @brief Perform unqualified name lookup starting from a given
1592 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
1593 /// used to find names within the current scope. For example, 'x' in
1597 /// return x; // unqualified name look finds 'x' in the global scope
1601 /// Different lookup criteria can find different names. For example, a
1602 /// particular scope can have both a struct and a function of the same
1603 /// name, and each can be found by certain lookup criteria. For more
1604 /// information about lookup criteria, see the documentation for the
1605 /// class LookupCriteria.
1607 /// @param S The scope from which unqualified name lookup will
1608 /// begin. If the lookup criteria permits, name lookup may also search
1609 /// in the parent scopes.
1611 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to
1612 /// look up and the lookup kind), and is updated with the results of lookup
1613 /// including zero or more declarations and possibly additional information
1614 /// used to diagnose ambiguities.
1616 /// @returns \c true if lookup succeeded and false otherwise.
1617 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
1618 DeclarationName Name = R.getLookupName();
1619 if (!Name) return false;
1621 LookupNameKind NameKind = R.getLookupKind();
1623 if (!getLangOpts().CPlusPlus) {
1624 // Unqualified name lookup in C/Objective-C is purely lexical, so
1625 // search in the declarations attached to the name.
1626 if (NameKind == Sema::LookupRedeclarationWithLinkage) {
1627 // Find the nearest non-transparent declaration scope.
1628 while (!(S->getFlags() & Scope::DeclScope) ||
1629 (S->getEntity() && S->getEntity()->isTransparentContext()))
1633 // When performing a scope lookup, we want to find local extern decls.
1634 FindLocalExternScope FindLocals(R);
1636 // Scan up the scope chain looking for a decl that matches this
1637 // identifier that is in the appropriate namespace. This search
1638 // should not take long, as shadowing of names is uncommon, and
1639 // deep shadowing is extremely uncommon.
1640 bool LeftStartingScope = false;
1642 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
1643 IEnd = IdResolver.end();
1645 if (NamedDecl *D = R.getAcceptableDecl(*I)) {
1646 if (NameKind == LookupRedeclarationWithLinkage) {
1647 // Determine whether this (or a previous) declaration is
1649 if (!LeftStartingScope && !S->isDeclScope(*I))
1650 LeftStartingScope = true;
1652 // If we found something outside of our starting scope that
1653 // does not have linkage, skip it.
1654 if (LeftStartingScope && !((*I)->hasLinkage())) {
1659 else if (NameKind == LookupObjCImplicitSelfParam &&
1660 !isa<ImplicitParamDecl>(*I))
1665 // Check whether there are any other declarations with the same name
1666 // and in the same scope.
1668 // Find the scope in which this declaration was declared (if it
1669 // actually exists in a Scope).
1670 while (S && !S->isDeclScope(D))
1673 // If the scope containing the declaration is the translation unit,
1674 // then we'll need to perform our checks based on the matching
1675 // DeclContexts rather than matching scopes.
1676 if (S && isNamespaceOrTranslationUnitScope(S))
1679 // Compute the DeclContext, if we need it.
1680 DeclContext *DC = nullptr;
1682 DC = (*I)->getDeclContext()->getRedeclContext();
1684 IdentifierResolver::iterator LastI = I;
1685 for (++LastI; LastI != IEnd; ++LastI) {
1687 // Match based on scope.
1688 if (!S->isDeclScope(*LastI))
1691 // Match based on DeclContext.
1693 = (*LastI)->getDeclContext()->getRedeclContext();
1694 if (!LastDC->Equals(DC))
1698 // If the declaration is in the right namespace and visible, add it.
1699 if (NamedDecl *LastD = R.getAcceptableDecl(*LastI))
1709 // Perform C++ unqualified name lookup.
1710 if (CppLookupName(R, S))
1714 // If we didn't find a use of this identifier, and if the identifier
1715 // corresponds to a compiler builtin, create the decl object for the builtin
1716 // now, injecting it into translation unit scope, and return it.
1717 if (AllowBuiltinCreation && LookupBuiltin(*this, R))
1720 // If we didn't find a use of this identifier, the ExternalSource
1721 // may be able to handle the situation.
1722 // Note: some lookup failures are expected!
1723 // See e.g. R.isForRedeclaration().
1724 return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
1727 /// @brief Perform qualified name lookup in the namespaces nominated by
1728 /// using directives by the given context.
1730 /// C++98 [namespace.qual]p2:
1731 /// Given X::m (where X is a user-declared namespace), or given \::m
1732 /// (where X is the global namespace), let S be the set of all
1733 /// declarations of m in X and in the transitive closure of all
1734 /// namespaces nominated by using-directives in X and its used
1735 /// namespaces, except that using-directives are ignored in any
1736 /// namespace, including X, directly containing one or more
1737 /// declarations of m. No namespace is searched more than once in
1738 /// the lookup of a name. If S is the empty set, the program is
1739 /// ill-formed. Otherwise, if S has exactly one member, or if the
1740 /// context of the reference is a using-declaration
1741 /// (namespace.udecl), S is the required set of declarations of
1742 /// m. Otherwise if the use of m is not one that allows a unique
1743 /// declaration to be chosen from S, the program is ill-formed.
1745 /// C++98 [namespace.qual]p5:
1746 /// During the lookup of a qualified namespace member name, if the
1747 /// lookup finds more than one declaration of the member, and if one
1748 /// declaration introduces a class name or enumeration name and the
1749 /// other declarations either introduce the same object, the same
1750 /// enumerator or a set of functions, the non-type name hides the
1751 /// class or enumeration name if and only if the declarations are
1752 /// from the same namespace; otherwise (the declarations are from
1753 /// different namespaces), the program is ill-formed.
1754 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
1755 DeclContext *StartDC) {
1756 assert(StartDC->isFileContext() && "start context is not a file context");
1758 DeclContext::udir_range UsingDirectives = StartDC->using_directives();
1759 if (UsingDirectives.begin() == UsingDirectives.end()) return false;
1761 // We have at least added all these contexts to the queue.
1762 llvm::SmallPtrSet<DeclContext*, 8> Visited;
1763 Visited.insert(StartDC);
1765 // We have not yet looked into these namespaces, much less added
1766 // their "using-children" to the queue.
1767 SmallVector<NamespaceDecl*, 8> Queue;
1769 // We have already looked into the initial namespace; seed the queue
1770 // with its using-children.
1771 for (auto *I : UsingDirectives) {
1772 NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace();
1773 if (Visited.insert(ND).second)
1774 Queue.push_back(ND);
1777 // The easiest way to implement the restriction in [namespace.qual]p5
1778 // is to check whether any of the individual results found a tag
1779 // and, if so, to declare an ambiguity if the final result is not
1781 bool FoundTag = false;
1782 bool FoundNonTag = false;
1784 LookupResult LocalR(LookupResult::Temporary, R);
1787 while (!Queue.empty()) {
1788 NamespaceDecl *ND = Queue.pop_back_val();
1790 // We go through some convolutions here to avoid copying results
1791 // between LookupResults.
1792 bool UseLocal = !R.empty();
1793 LookupResult &DirectR = UseLocal ? LocalR : R;
1794 bool FoundDirect = LookupDirect(S, DirectR, ND);
1797 // First do any local hiding.
1798 DirectR.resolveKind();
1800 // If the local result is a tag, remember that.
1801 if (DirectR.isSingleTagDecl())
1806 // Append the local results to the total results if necessary.
1808 R.addAllDecls(LocalR);
1813 // If we find names in this namespace, ignore its using directives.
1819 for (auto I : ND->using_directives()) {
1820 NamespaceDecl *Nom = I->getNominatedNamespace();
1821 if (Visited.insert(Nom).second)
1822 Queue.push_back(Nom);
1827 if (FoundTag && FoundNonTag)
1828 R.setAmbiguousQualifiedTagHiding();
1836 /// \brief Callback that looks for any member of a class with the given name.
1837 static bool LookupAnyMember(const CXXBaseSpecifier *Specifier,
1838 CXXBasePath &Path, DeclarationName Name) {
1839 RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
1841 Path.Decls = BaseRecord->lookup(Name);
1842 return !Path.Decls.empty();
1845 /// \brief Determine whether the given set of member declarations contains only
1846 /// static members, nested types, and enumerators.
1847 template<typename InputIterator>
1848 static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) {
1849 Decl *D = (*First)->getUnderlyingDecl();
1850 if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D))
1853 if (isa<CXXMethodDecl>(D)) {
1854 // Determine whether all of the methods are static.
1855 bool AllMethodsAreStatic = true;
1856 for(; First != Last; ++First) {
1857 D = (*First)->getUnderlyingDecl();
1859 if (!isa<CXXMethodDecl>(D)) {
1860 assert(isa<TagDecl>(D) && "Non-function must be a tag decl");
1864 if (!cast<CXXMethodDecl>(D)->isStatic()) {
1865 AllMethodsAreStatic = false;
1870 if (AllMethodsAreStatic)
1877 /// \brief Perform qualified name lookup into a given context.
1879 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
1880 /// names when the context of those names is explicit specified, e.g.,
1881 /// "std::vector" or "x->member", or as part of unqualified name lookup.
1883 /// Different lookup criteria can find different names. For example, a
1884 /// particular scope can have both a struct and a function of the same
1885 /// name, and each can be found by certain lookup criteria. For more
1886 /// information about lookup criteria, see the documentation for the
1887 /// class LookupCriteria.
1889 /// \param R captures both the lookup criteria and any lookup results found.
1891 /// \param LookupCtx The context in which qualified name lookup will
1892 /// search. If the lookup criteria permits, name lookup may also search
1893 /// in the parent contexts or (for C++ classes) base classes.
1895 /// \param InUnqualifiedLookup true if this is qualified name lookup that
1896 /// occurs as part of unqualified name lookup.
1898 /// \returns true if lookup succeeded, false if it failed.
1899 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
1900 bool InUnqualifiedLookup) {
1901 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
1903 if (!R.getLookupName())
1906 // Make sure that the declaration context is complete.
1907 assert((!isa<TagDecl>(LookupCtx) ||
1908 LookupCtx->isDependentContext() ||
1909 cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
1910 cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
1911 "Declaration context must already be complete!");
1913 struct QualifiedLookupInScope {
1915 DeclContext *Context;
1916 // Set flag in DeclContext informing debugger that we're looking for qualified name
1917 QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) {
1918 oldVal = ctx->setUseQualifiedLookup();
1920 ~QualifiedLookupInScope() {
1921 Context->setUseQualifiedLookup(oldVal);
1925 if (LookupDirect(*this, R, LookupCtx)) {
1927 if (isa<CXXRecordDecl>(LookupCtx))
1928 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
1932 // Don't descend into implied contexts for redeclarations.
1933 // C++98 [namespace.qual]p6:
1934 // In a declaration for a namespace member in which the
1935 // declarator-id is a qualified-id, given that the qualified-id
1936 // for the namespace member has the form
1937 // nested-name-specifier unqualified-id
1938 // the unqualified-id shall name a member of the namespace
1939 // designated by the nested-name-specifier.
1940 // See also [class.mfct]p5 and [class.static.data]p2.
1941 if (R.isForRedeclaration())
1944 // If this is a namespace, look it up in the implied namespaces.
1945 if (LookupCtx->isFileContext())
1946 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
1948 // If this isn't a C++ class, we aren't allowed to look into base
1949 // classes, we're done.
1950 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
1951 if (!LookupRec || !LookupRec->getDefinition())
1954 // If we're performing qualified name lookup into a dependent class,
1955 // then we are actually looking into a current instantiation. If we have any
1956 // dependent base classes, then we either have to delay lookup until
1957 // template instantiation time (at which point all bases will be available)
1958 // or we have to fail.
1959 if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
1960 LookupRec->hasAnyDependentBases()) {
1961 R.setNotFoundInCurrentInstantiation();
1965 // Perform lookup into our base classes.
1967 Paths.setOrigin(LookupRec);
1969 // Look for this member in our base classes
1970 bool (*BaseCallback)(const CXXBaseSpecifier *Specifier, CXXBasePath &Path,
1971 DeclarationName Name) = nullptr;
1972 switch (R.getLookupKind()) {
1973 case LookupObjCImplicitSelfParam:
1974 case LookupOrdinaryName:
1975 case LookupMemberName:
1976 case LookupRedeclarationWithLinkage:
1977 case LookupLocalFriendName:
1978 BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
1982 BaseCallback = &CXXRecordDecl::FindTagMember;
1986 BaseCallback = &LookupAnyMember;
1989 case LookupUsingDeclName:
1990 // This lookup is for redeclarations only.
1992 case LookupOperatorName:
1993 case LookupNamespaceName:
1994 case LookupObjCProtocolName:
1996 // These lookups will never find a member in a C++ class (or base class).
1999 case LookupNestedNameSpecifierName:
2000 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember;
2004 DeclarationName Name = R.getLookupName();
2005 if (!LookupRec->lookupInBases(
2006 [=](const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
2007 return BaseCallback(Specifier, Path, Name);
2012 R.setNamingClass(LookupRec);
2014 // C++ [class.member.lookup]p2:
2015 // [...] If the resulting set of declarations are not all from
2016 // sub-objects of the same type, or the set has a nonstatic member
2017 // and includes members from distinct sub-objects, there is an
2018 // ambiguity and the program is ill-formed. Otherwise that set is
2019 // the result of the lookup.
2020 QualType SubobjectType;
2021 int SubobjectNumber = 0;
2022 AccessSpecifier SubobjectAccess = AS_none;
2024 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
2025 Path != PathEnd; ++Path) {
2026 const CXXBasePathElement &PathElement = Path->back();
2028 // Pick the best (i.e. most permissive i.e. numerically lowest) access
2029 // across all paths.
2030 SubobjectAccess = std::min(SubobjectAccess, Path->Access);
2032 // Determine whether we're looking at a distinct sub-object or not.
2033 if (SubobjectType.isNull()) {
2034 // This is the first subobject we've looked at. Record its type.
2035 SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
2036 SubobjectNumber = PathElement.SubobjectNumber;
2041 != Context.getCanonicalType(PathElement.Base->getType())) {
2042 // We found members of the given name in two subobjects of
2043 // different types. If the declaration sets aren't the same, this
2044 // lookup is ambiguous.
2045 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) {
2046 CXXBasePaths::paths_iterator FirstPath = Paths.begin();
2047 DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin();
2048 DeclContext::lookup_iterator CurrentD = Path->Decls.begin();
2050 while (FirstD != FirstPath->Decls.end() &&
2051 CurrentD != Path->Decls.end()) {
2052 if ((*FirstD)->getUnderlyingDecl()->getCanonicalDecl() !=
2053 (*CurrentD)->getUnderlyingDecl()->getCanonicalDecl())
2060 if (FirstD == FirstPath->Decls.end() &&
2061 CurrentD == Path->Decls.end())
2065 R.setAmbiguousBaseSubobjectTypes(Paths);
2069 if (SubobjectNumber != PathElement.SubobjectNumber) {
2070 // We have a different subobject of the same type.
2072 // C++ [class.member.lookup]p5:
2073 // A static member, a nested type or an enumerator defined in
2074 // a base class T can unambiguously be found even if an object
2075 // has more than one base class subobject of type T.
2076 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end()))
2079 // We have found a nonstatic member name in multiple, distinct
2080 // subobjects. Name lookup is ambiguous.
2081 R.setAmbiguousBaseSubobjects(Paths);
2086 // Lookup in a base class succeeded; return these results.
2088 for (auto *D : Paths.front().Decls) {
2089 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
2097 /// \brief Performs qualified name lookup or special type of lookup for
2098 /// "__super::" scope specifier.
2100 /// This routine is a convenience overload meant to be called from contexts
2101 /// that need to perform a qualified name lookup with an optional C++ scope
2102 /// specifier that might require special kind of lookup.
2104 /// \param R captures both the lookup criteria and any lookup results found.
2106 /// \param LookupCtx The context in which qualified name lookup will
2109 /// \param SS An optional C++ scope-specifier.
2111 /// \returns true if lookup succeeded, false if it failed.
2112 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2114 auto *NNS = SS.getScopeRep();
2115 if (NNS && NNS->getKind() == NestedNameSpecifier::Super)
2116 return LookupInSuper(R, NNS->getAsRecordDecl());
2119 return LookupQualifiedName(R, LookupCtx);
2122 /// @brief Performs name lookup for a name that was parsed in the
2123 /// source code, and may contain a C++ scope specifier.
2125 /// This routine is a convenience routine meant to be called from
2126 /// contexts that receive a name and an optional C++ scope specifier
2127 /// (e.g., "N::M::x"). It will then perform either qualified or
2128 /// unqualified name lookup (with LookupQualifiedName or LookupName,
2129 /// respectively) on the given name and return those results. It will
2130 /// perform a special type of lookup for "__super::" scope specifier.
2132 /// @param S The scope from which unqualified name lookup will
2135 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
2137 /// @param EnteringContext Indicates whether we are going to enter the
2138 /// context of the scope-specifier SS (if present).
2140 /// @returns True if any decls were found (but possibly ambiguous)
2141 bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
2142 bool AllowBuiltinCreation, bool EnteringContext) {
2143 if (SS && SS->isInvalid()) {
2144 // When the scope specifier is invalid, don't even look for
2149 if (SS && SS->isSet()) {
2150 NestedNameSpecifier *NNS = SS->getScopeRep();
2151 if (NNS->getKind() == NestedNameSpecifier::Super)
2152 return LookupInSuper(R, NNS->getAsRecordDecl());
2154 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
2155 // We have resolved the scope specifier to a particular declaration
2156 // contex, and will perform name lookup in that context.
2157 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
2160 R.setContextRange(SS->getRange());
2161 return LookupQualifiedName(R, DC);
2164 // We could not resolve the scope specified to a specific declaration
2165 // context, which means that SS refers to an unknown specialization.
2166 // Name lookup can't find anything in this case.
2167 R.setNotFoundInCurrentInstantiation();
2168 R.setContextRange(SS->getRange());
2172 // Perform unqualified name lookup starting in the given scope.
2173 return LookupName(R, S, AllowBuiltinCreation);
2176 /// \brief Perform qualified name lookup into all base classes of the given
2179 /// \param R captures both the lookup criteria and any lookup results found.
2181 /// \param Class The context in which qualified name lookup will
2182 /// search. Name lookup will search in all base classes merging the results.
2184 /// @returns True if any decls were found (but possibly ambiguous)
2185 bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) {
2186 // The access-control rules we use here are essentially the rules for
2187 // doing a lookup in Class that just magically skipped the direct
2188 // members of Class itself. That is, the naming class is Class, and the
2189 // access includes the access of the base.
2190 for (const auto &BaseSpec : Class->bases()) {
2191 CXXRecordDecl *RD = cast<CXXRecordDecl>(
2192 BaseSpec.getType()->castAs<RecordType>()->getDecl());
2193 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
2194 Result.setBaseObjectType(Context.getRecordType(Class));
2195 LookupQualifiedName(Result, RD);
2197 // Copy the lookup results into the target, merging the base's access into
2199 for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
2200 R.addDecl(I.getDecl(),
2201 CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(),
2205 Result.suppressDiagnostics();
2209 R.setNamingClass(Class);
2214 /// \brief Produce a diagnostic describing the ambiguity that resulted
2215 /// from name lookup.
2217 /// \param Result The result of the ambiguous lookup to be diagnosed.
2218 void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
2219 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
2221 DeclarationName Name = Result.getLookupName();
2222 SourceLocation NameLoc = Result.getNameLoc();
2223 SourceRange LookupRange = Result.getContextRange();
2225 switch (Result.getAmbiguityKind()) {
2226 case LookupResult::AmbiguousBaseSubobjects: {
2227 CXXBasePaths *Paths = Result.getBasePaths();
2228 QualType SubobjectType = Paths->front().back().Base->getType();
2229 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
2230 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
2233 DeclContext::lookup_iterator Found = Paths->front().Decls.begin();
2234 while (isa<CXXMethodDecl>(*Found) &&
2235 cast<CXXMethodDecl>(*Found)->isStatic())
2238 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
2242 case LookupResult::AmbiguousBaseSubobjectTypes: {
2243 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
2244 << Name << LookupRange;
2246 CXXBasePaths *Paths = Result.getBasePaths();
2247 std::set<Decl *> DeclsPrinted;
2248 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
2249 PathEnd = Paths->end();
2250 Path != PathEnd; ++Path) {
2251 Decl *D = Path->Decls.front();
2252 if (DeclsPrinted.insert(D).second)
2253 Diag(D->getLocation(), diag::note_ambiguous_member_found);
2258 case LookupResult::AmbiguousTagHiding: {
2259 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
2261 llvm::SmallPtrSet<NamedDecl*, 8> TagDecls;
2263 for (auto *D : Result)
2264 if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
2265 TagDecls.insert(TD);
2266 Diag(TD->getLocation(), diag::note_hidden_tag);
2269 for (auto *D : Result)
2270 if (!isa<TagDecl>(D))
2271 Diag(D->getLocation(), diag::note_hiding_object);
2273 // For recovery purposes, go ahead and implement the hiding.
2274 LookupResult::Filter F = Result.makeFilter();
2275 while (F.hasNext()) {
2276 if (TagDecls.count(F.next()))
2283 case LookupResult::AmbiguousReference: {
2284 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
2286 for (auto *D : Result)
2287 Diag(D->getLocation(), diag::note_ambiguous_candidate) << D;
2294 struct AssociatedLookup {
2295 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
2296 Sema::AssociatedNamespaceSet &Namespaces,
2297 Sema::AssociatedClassSet &Classes)
2298 : S(S), Namespaces(Namespaces), Classes(Classes),
2299 InstantiationLoc(InstantiationLoc) {
2303 Sema::AssociatedNamespaceSet &Namespaces;
2304 Sema::AssociatedClassSet &Classes;
2305 SourceLocation InstantiationLoc;
2307 } // end anonymous namespace
2310 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
2312 static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces,
2314 // Add the associated namespace for this class.
2316 // We don't use DeclContext::getEnclosingNamespaceContext() as this may
2317 // be a locally scoped record.
2319 // We skip out of inline namespaces. The innermost non-inline namespace
2320 // contains all names of all its nested inline namespaces anyway, so we can
2321 // replace the entire inline namespace tree with its root.
2322 while (Ctx->isRecord() || Ctx->isTransparentContext() ||
2323 Ctx->isInlineNamespace())
2324 Ctx = Ctx->getParent();
2326 if (Ctx->isFileContext())
2327 Namespaces.insert(Ctx->getPrimaryContext());
2330 // \brief Add the associated classes and namespaces for argument-dependent
2331 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2).
2333 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2334 const TemplateArgument &Arg) {
2335 // C++ [basic.lookup.koenig]p2, last bullet:
2337 switch (Arg.getKind()) {
2338 case TemplateArgument::Null:
2341 case TemplateArgument::Type:
2342 // [...] the namespaces and classes associated with the types of the
2343 // template arguments provided for template type parameters (excluding
2344 // template template parameters)
2345 addAssociatedClassesAndNamespaces(Result, Arg.getAsType());
2348 case TemplateArgument::Template:
2349 case TemplateArgument::TemplateExpansion: {
2350 // [...] the namespaces in which any template template arguments are
2351 // defined; and the classes in which any member templates used as
2352 // template template arguments are defined.
2353 TemplateName Template = Arg.getAsTemplateOrTemplatePattern();
2354 if (ClassTemplateDecl *ClassTemplate
2355 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
2356 DeclContext *Ctx = ClassTemplate->getDeclContext();
2357 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2358 Result.Classes.insert(EnclosingClass);
2359 // Add the associated namespace for this class.
2360 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2365 case TemplateArgument::Declaration:
2366 case TemplateArgument::Integral:
2367 case TemplateArgument::Expression:
2368 case TemplateArgument::NullPtr:
2369 // [Note: non-type template arguments do not contribute to the set of
2370 // associated namespaces. ]
2373 case TemplateArgument::Pack:
2374 for (const auto &P : Arg.pack_elements())
2375 addAssociatedClassesAndNamespaces(Result, P);
2380 // \brief Add the associated classes and namespaces for
2381 // argument-dependent lookup with an argument of class type
2382 // (C++ [basic.lookup.koenig]p2).
2384 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2385 CXXRecordDecl *Class) {
2387 // Just silently ignore anything whose name is __va_list_tag.
2388 if (Class->getDeclName() == Result.S.VAListTagName)
2391 // C++ [basic.lookup.koenig]p2:
2393 // -- If T is a class type (including unions), its associated
2394 // classes are: the class itself; the class of which it is a
2395 // member, if any; and its direct and indirect base
2396 // classes. Its associated namespaces are the namespaces in
2397 // which its associated classes are defined.
2399 // Add the class of which it is a member, if any.
2400 DeclContext *Ctx = Class->getDeclContext();
2401 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2402 Result.Classes.insert(EnclosingClass);
2403 // Add the associated namespace for this class.
2404 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2406 // Add the class itself. If we've already seen this class, we don't
2407 // need to visit base classes.
2409 // FIXME: That's not correct, we may have added this class only because it
2410 // was the enclosing class of another class, and in that case we won't have
2411 // added its base classes yet.
2412 if (!Result.Classes.insert(Class).second)
2415 // -- If T is a template-id, its associated namespaces and classes are
2416 // the namespace in which the template is defined; for member
2417 // templates, the member template's class; the namespaces and classes
2418 // associated with the types of the template arguments provided for
2419 // template type parameters (excluding template template parameters); the
2420 // namespaces in which any template template arguments are defined; and
2421 // the classes in which any member templates used as template template
2422 // arguments are defined. [Note: non-type template arguments do not
2423 // contribute to the set of associated namespaces. ]
2424 if (ClassTemplateSpecializationDecl *Spec
2425 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
2426 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
2427 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2428 Result.Classes.insert(EnclosingClass);
2429 // Add the associated namespace for this class.
2430 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2432 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
2433 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2434 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]);
2437 // Only recurse into base classes for complete types.
2438 if (!Result.S.isCompleteType(Result.InstantiationLoc,
2439 Result.S.Context.getRecordType(Class)))
2442 // Add direct and indirect base classes along with their associated
2444 SmallVector<CXXRecordDecl *, 32> Bases;
2445 Bases.push_back(Class);
2446 while (!Bases.empty()) {
2447 // Pop this class off the stack.
2448 Class = Bases.pop_back_val();
2450 // Visit the base classes.
2451 for (const auto &Base : Class->bases()) {
2452 const RecordType *BaseType = Base.getType()->getAs<RecordType>();
2453 // In dependent contexts, we do ADL twice, and the first time around,
2454 // the base type might be a dependent TemplateSpecializationType, or a
2455 // TemplateTypeParmType. If that happens, simply ignore it.
2456 // FIXME: If we want to support export, we probably need to add the
2457 // namespace of the template in a TemplateSpecializationType, or even
2458 // the classes and namespaces of known non-dependent arguments.
2461 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
2462 if (Result.Classes.insert(BaseDecl).second) {
2463 // Find the associated namespace for this base class.
2464 DeclContext *BaseCtx = BaseDecl->getDeclContext();
2465 CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
2467 // Make sure we visit the bases of this base class.
2468 if (BaseDecl->bases_begin() != BaseDecl->bases_end())
2469 Bases.push_back(BaseDecl);
2475 // \brief Add the associated classes and namespaces for
2476 // argument-dependent lookup with an argument of type T
2477 // (C++ [basic.lookup.koenig]p2).
2479 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
2480 // C++ [basic.lookup.koenig]p2:
2482 // For each argument type T in the function call, there is a set
2483 // of zero or more associated namespaces and a set of zero or more
2484 // associated classes to be considered. The sets of namespaces and
2485 // classes is determined entirely by the types of the function
2486 // arguments (and the namespace of any template template
2487 // argument). Typedef names and using-declarations used to specify
2488 // the types do not contribute to this set. The sets of namespaces
2489 // and classes are determined in the following way:
2491 SmallVector<const Type *, 16> Queue;
2492 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
2495 switch (T->getTypeClass()) {
2497 #define TYPE(Class, Base)
2498 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
2499 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
2500 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
2501 #define ABSTRACT_TYPE(Class, Base)
2502 #include "clang/AST/TypeNodes.def"
2503 // T is canonical. We can also ignore dependent types because
2504 // we don't need to do ADL at the definition point, but if we
2505 // wanted to implement template export (or if we find some other
2506 // use for associated classes and namespaces...) this would be
2510 // -- If T is a pointer to U or an array of U, its associated
2511 // namespaces and classes are those associated with U.
2513 T = cast<PointerType>(T)->getPointeeType().getTypePtr();
2515 case Type::ConstantArray:
2516 case Type::IncompleteArray:
2517 case Type::VariableArray:
2518 T = cast<ArrayType>(T)->getElementType().getTypePtr();
2521 // -- If T is a fundamental type, its associated sets of
2522 // namespaces and classes are both empty.
2526 // -- If T is a class type (including unions), its associated
2527 // classes are: the class itself; the class of which it is a
2528 // member, if any; and its direct and indirect base
2529 // classes. Its associated namespaces are the namespaces in
2530 // which its associated classes are defined.
2531 case Type::Record: {
2532 CXXRecordDecl *Class =
2533 cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl());
2534 addAssociatedClassesAndNamespaces(Result, Class);
2538 // -- If T is an enumeration type, its associated namespace is
2539 // the namespace in which it is defined. If it is class
2540 // member, its associated class is the member's class; else
2541 // it has no associated class.
2543 EnumDecl *Enum = cast<EnumType>(T)->getDecl();
2545 DeclContext *Ctx = Enum->getDeclContext();
2546 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2547 Result.Classes.insert(EnclosingClass);
2549 // Add the associated namespace for this class.
2550 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2555 // -- If T is a function type, its associated namespaces and
2556 // classes are those associated with the function parameter
2557 // types and those associated with the return type.
2558 case Type::FunctionProto: {
2559 const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
2560 for (const auto &Arg : Proto->param_types())
2561 Queue.push_back(Arg.getTypePtr());
2564 case Type::FunctionNoProto: {
2565 const FunctionType *FnType = cast<FunctionType>(T);
2566 T = FnType->getReturnType().getTypePtr();
2570 // -- If T is a pointer to a member function of a class X, its
2571 // associated namespaces and classes are those associated
2572 // with the function parameter types and return type,
2573 // together with those associated with X.
2575 // -- If T is a pointer to a data member of class X, its
2576 // associated namespaces and classes are those associated
2577 // with the member type together with those associated with
2579 case Type::MemberPointer: {
2580 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T);
2582 // Queue up the class type into which this points.
2583 Queue.push_back(MemberPtr->getClass());
2585 // And directly continue with the pointee type.
2586 T = MemberPtr->getPointeeType().getTypePtr();
2590 // As an extension, treat this like a normal pointer.
2591 case Type::BlockPointer:
2592 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr();
2595 // References aren't covered by the standard, but that's such an
2596 // obvious defect that we cover them anyway.
2597 case Type::LValueReference:
2598 case Type::RValueReference:
2599 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr();
2602 // These are fundamental types.
2604 case Type::ExtVector:
2608 // Non-deduced auto types only get here for error cases.
2612 // If T is an Objective-C object or interface type, or a pointer to an
2613 // object or interface type, the associated namespace is the global
2615 case Type::ObjCObject:
2616 case Type::ObjCInterface:
2617 case Type::ObjCObjectPointer:
2618 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
2621 // Atomic types are just wrappers; use the associations of the
2624 T = cast<AtomicType>(T)->getValueType().getTypePtr();
2627 T = cast<PipeType>(T)->getElementType().getTypePtr();
2633 T = Queue.pop_back_val();
2637 /// \brief Find the associated classes and namespaces for
2638 /// argument-dependent lookup for a call with the given set of
2641 /// This routine computes the sets of associated classes and associated
2642 /// namespaces searched by argument-dependent lookup
2643 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
2644 void Sema::FindAssociatedClassesAndNamespaces(
2645 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
2646 AssociatedNamespaceSet &AssociatedNamespaces,
2647 AssociatedClassSet &AssociatedClasses) {
2648 AssociatedNamespaces.clear();
2649 AssociatedClasses.clear();
2651 AssociatedLookup Result(*this, InstantiationLoc,
2652 AssociatedNamespaces, AssociatedClasses);
2654 // C++ [basic.lookup.koenig]p2:
2655 // For each argument type T in the function call, there is a set
2656 // of zero or more associated namespaces and a set of zero or more
2657 // associated classes to be considered. The sets of namespaces and
2658 // classes is determined entirely by the types of the function
2659 // arguments (and the namespace of any template template
2661 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
2662 Expr *Arg = Args[ArgIdx];
2664 if (Arg->getType() != Context.OverloadTy) {
2665 addAssociatedClassesAndNamespaces(Result, Arg->getType());
2669 // [...] In addition, if the argument is the name or address of a
2670 // set of overloaded functions and/or function templates, its
2671 // associated classes and namespaces are the union of those
2672 // associated with each of the members of the set: the namespace
2673 // in which the function or function template is defined and the
2674 // classes and namespaces associated with its (non-dependent)
2675 // parameter types and return type.
2676 Arg = Arg->IgnoreParens();
2677 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg))
2678 if (unaryOp->getOpcode() == UO_AddrOf)
2679 Arg = unaryOp->getSubExpr();
2681 UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg);
2684 for (const auto *D : ULE->decls()) {
2685 // Look through any using declarations to find the underlying function.
2686 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
2688 // Add the classes and namespaces associated with the parameter
2689 // types and return type of this function.
2690 addAssociatedClassesAndNamespaces(Result, FDecl->getType());
2695 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
2697 LookupNameKind NameKind,
2698 RedeclarationKind Redecl) {
2699 LookupResult R(*this, Name, Loc, NameKind, Redecl);
2701 return R.getAsSingle<NamedDecl>();
2704 /// \brief Find the protocol with the given name, if any.
2705 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II,
2706 SourceLocation IdLoc,
2707 RedeclarationKind Redecl) {
2708 Decl *D = LookupSingleName(TUScope, II, IdLoc,
2709 LookupObjCProtocolName, Redecl);
2710 return cast_or_null<ObjCProtocolDecl>(D);
2713 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
2714 QualType T1, QualType T2,
2715 UnresolvedSetImpl &Functions) {
2716 // C++ [over.match.oper]p3:
2717 // -- The set of non-member candidates is the result of the
2718 // unqualified lookup of operator@ in the context of the
2719 // expression according to the usual rules for name lookup in
2720 // unqualified function calls (3.4.2) except that all member
2721 // functions are ignored.
2722 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
2723 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
2724 LookupName(Operators, S);
2726 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
2727 Functions.append(Operators.begin(), Operators.end());
2730 Sema::SpecialMemberOverloadResult *Sema::LookupSpecialMember(CXXRecordDecl *RD,
2731 CXXSpecialMember SM,
2736 bool VolatileThis) {
2737 assert(CanDeclareSpecialMemberFunction(RD) &&
2738 "doing special member lookup into record that isn't fully complete");
2739 RD = RD->getDefinition();
2740 if (RValueThis || ConstThis || VolatileThis)
2741 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) &&
2742 "constructors and destructors always have unqualified lvalue this");
2743 if (ConstArg || VolatileArg)
2744 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) &&
2745 "parameter-less special members can't have qualified arguments");
2747 llvm::FoldingSetNodeID ID;
2750 ID.AddInteger(ConstArg);
2751 ID.AddInteger(VolatileArg);
2752 ID.AddInteger(RValueThis);
2753 ID.AddInteger(ConstThis);
2754 ID.AddInteger(VolatileThis);
2757 SpecialMemberOverloadResult *Result =
2758 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
2760 // This was already cached
2764 Result = BumpAlloc.Allocate<SpecialMemberOverloadResult>();
2765 Result = new (Result) SpecialMemberOverloadResult(ID);
2766 SpecialMemberCache.InsertNode(Result, InsertPoint);
2768 if (SM == CXXDestructor) {
2769 if (RD->needsImplicitDestructor())
2770 DeclareImplicitDestructor(RD);
2771 CXXDestructorDecl *DD = RD->getDestructor();
2772 assert(DD && "record without a destructor");
2773 Result->setMethod(DD);
2774 Result->setKind(DD->isDeleted() ?
2775 SpecialMemberOverloadResult::NoMemberOrDeleted :
2776 SpecialMemberOverloadResult::Success);
2780 // Prepare for overload resolution. Here we construct a synthetic argument
2781 // if necessary and make sure that implicit functions are declared.
2782 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD));
2783 DeclarationName Name;
2784 Expr *Arg = nullptr;
2787 QualType ArgType = CanTy;
2788 ExprValueKind VK = VK_LValue;
2790 if (SM == CXXDefaultConstructor) {
2791 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2793 if (RD->needsImplicitDefaultConstructor())
2794 DeclareImplicitDefaultConstructor(RD);
2796 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) {
2797 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2798 if (RD->needsImplicitCopyConstructor())
2799 DeclareImplicitCopyConstructor(RD);
2800 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor())
2801 DeclareImplicitMoveConstructor(RD);
2803 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
2804 if (RD->needsImplicitCopyAssignment())
2805 DeclareImplicitCopyAssignment(RD);
2806 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment())
2807 DeclareImplicitMoveAssignment(RD);
2813 ArgType.addVolatile();
2815 // This isn't /really/ specified by the standard, but it's implied
2816 // we should be working from an RValue in the case of move to ensure
2817 // that we prefer to bind to rvalue references, and an LValue in the
2818 // case of copy to ensure we don't bind to rvalue references.
2819 // Possibly an XValue is actually correct in the case of move, but
2820 // there is no semantic difference for class types in this restricted
2822 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment)
2828 OpaqueValueExpr FakeArg(SourceLocation(), ArgType, VK);
2830 if (SM != CXXDefaultConstructor) {
2835 // Create the object argument
2836 QualType ThisTy = CanTy;
2840 ThisTy.addVolatile();
2841 Expr::Classification Classification =
2842 OpaqueValueExpr(SourceLocation(), ThisTy,
2843 RValueThis ? VK_RValue : VK_LValue).Classify(Context);
2845 // Now we perform lookup on the name we computed earlier and do overload
2846 // resolution. Lookup is only performed directly into the class since there
2847 // will always be a (possibly implicit) declaration to shadow any others.
2848 OverloadCandidateSet OCS(RD->getLocation(), OverloadCandidateSet::CSK_Normal);
2849 DeclContext::lookup_result R = RD->lookup(Name);
2852 // We might have no default constructor because we have a lambda's closure
2853 // type, rather than because there's some other declared constructor.
2854 // Every class has a copy/move constructor, copy/move assignment, and
2856 assert(SM == CXXDefaultConstructor &&
2857 "lookup for a constructor or assignment operator was empty");
2858 Result->setMethod(nullptr);
2859 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2863 // Copy the candidates as our processing of them may load new declarations
2864 // from an external source and invalidate lookup_result.
2865 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
2867 for (auto *Cand : Candidates) {
2868 if (Cand->isInvalidDecl())
2871 if (UsingShadowDecl *U = dyn_cast<UsingShadowDecl>(Cand)) {
2872 // FIXME: [namespace.udecl]p15 says that we should only consider a
2873 // using declaration here if it does not match a declaration in the
2874 // derived class. We do not implement this correctly in other cases
2876 Cand = U->getTargetDecl();
2878 if (Cand->isInvalidDecl())
2882 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand)) {
2883 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2884 AddMethodCandidate(M, DeclAccessPair::make(M, AS_public), RD, ThisTy,
2885 Classification, llvm::makeArrayRef(&Arg, NumArgs),
2888 AddOverloadCandidate(M, DeclAccessPair::make(M, AS_public),
2889 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2890 } else if (FunctionTemplateDecl *Tmpl =
2891 dyn_cast<FunctionTemplateDecl>(Cand)) {
2892 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2893 AddMethodTemplateCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public),
2894 RD, nullptr, ThisTy, Classification,
2895 llvm::makeArrayRef(&Arg, NumArgs),
2898 AddTemplateOverloadCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public),
2899 nullptr, llvm::makeArrayRef(&Arg, NumArgs),
2902 assert(isa<UsingDecl>(Cand) && "illegal Kind of operator = Decl");
2906 OverloadCandidateSet::iterator Best;
2907 switch (OCS.BestViableFunction(*this, SourceLocation(), Best)) {
2909 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
2910 Result->setKind(SpecialMemberOverloadResult::Success);
2914 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
2915 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2919 Result->setMethod(nullptr);
2920 Result->setKind(SpecialMemberOverloadResult::Ambiguous);
2923 case OR_No_Viable_Function:
2924 Result->setMethod(nullptr);
2925 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2932 /// \brief Look up the default constructor for the given class.
2933 CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) {
2934 SpecialMemberOverloadResult *Result =
2935 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false,
2938 return cast_or_null<CXXConstructorDecl>(Result->getMethod());
2941 /// \brief Look up the copying constructor for the given class.
2942 CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class,
2944 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
2945 "non-const, non-volatile qualifiers for copy ctor arg");
2946 SpecialMemberOverloadResult *Result =
2947 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const,
2948 Quals & Qualifiers::Volatile, false, false, false);
2950 return cast_or_null<CXXConstructorDecl>(Result->getMethod());
2953 /// \brief Look up the moving constructor for the given class.
2954 CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class,
2956 SpecialMemberOverloadResult *Result =
2957 LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const,
2958 Quals & Qualifiers::Volatile, false, false, false);
2960 return cast_or_null<CXXConstructorDecl>(Result->getMethod());
2963 /// \brief Look up the constructors for the given class.
2964 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) {
2965 // If the implicit constructors have not yet been declared, do so now.
2966 if (CanDeclareSpecialMemberFunction(Class)) {
2967 if (Class->needsImplicitDefaultConstructor())
2968 DeclareImplicitDefaultConstructor(Class);
2969 if (Class->needsImplicitCopyConstructor())
2970 DeclareImplicitCopyConstructor(Class);
2971 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
2972 DeclareImplicitMoveConstructor(Class);
2975 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class));
2976 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T);
2977 return Class->lookup(Name);
2980 /// \brief Look up the copying assignment operator for the given class.
2981 CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class,
2982 unsigned Quals, bool RValueThis,
2983 unsigned ThisQuals) {
2984 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
2985 "non-const, non-volatile qualifiers for copy assignment arg");
2986 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
2987 "non-const, non-volatile qualifiers for copy assignment this");
2988 SpecialMemberOverloadResult *Result =
2989 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const,
2990 Quals & Qualifiers::Volatile, RValueThis,
2991 ThisQuals & Qualifiers::Const,
2992 ThisQuals & Qualifiers::Volatile);
2994 return Result->getMethod();
2997 /// \brief Look up the moving assignment operator for the given class.
2998 CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class,
3001 unsigned ThisQuals) {
3002 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3003 "non-const, non-volatile qualifiers for copy assignment this");
3004 SpecialMemberOverloadResult *Result =
3005 LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const,
3006 Quals & Qualifiers::Volatile, RValueThis,
3007 ThisQuals & Qualifiers::Const,
3008 ThisQuals & Qualifiers::Volatile);
3010 return Result->getMethod();
3013 /// \brief Look for the destructor of the given class.
3015 /// During semantic analysis, this routine should be used in lieu of
3016 /// CXXRecordDecl::getDestructor().
3018 /// \returns The destructor for this class.
3019 CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) {
3020 return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor,
3021 false, false, false,
3022 false, false)->getMethod());
3025 /// LookupLiteralOperator - Determine which literal operator should be used for
3026 /// a user-defined literal, per C++11 [lex.ext].
3028 /// Normal overload resolution is not used to select which literal operator to
3029 /// call for a user-defined literal. Look up the provided literal operator name,
3030 /// and filter the results to the appropriate set for the given argument types.
3031 Sema::LiteralOperatorLookupResult
3032 Sema::LookupLiteralOperator(Scope *S, LookupResult &R,
3033 ArrayRef<QualType> ArgTys,
3034 bool AllowRaw, bool AllowTemplate,
3035 bool AllowStringTemplate) {
3037 assert(R.getResultKind() != LookupResult::Ambiguous &&
3038 "literal operator lookup can't be ambiguous");
3040 // Filter the lookup results appropriately.
3041 LookupResult::Filter F = R.makeFilter();
3043 bool FoundRaw = false;
3044 bool FoundTemplate = false;
3045 bool FoundStringTemplate = false;
3046 bool FoundExactMatch = false;
3048 while (F.hasNext()) {
3050 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
3051 D = USD->getTargetDecl();
3053 // If the declaration we found is invalid, skip it.
3054 if (D->isInvalidDecl()) {
3060 bool IsTemplate = false;
3061 bool IsStringTemplate = false;
3062 bool IsExactMatch = false;
3064 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
3065 if (FD->getNumParams() == 1 &&
3066 FD->getParamDecl(0)->getType()->getAs<PointerType>())
3068 else if (FD->getNumParams() == ArgTys.size()) {
3069 IsExactMatch = true;
3070 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
3071 QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
3072 if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
3073 IsExactMatch = false;
3079 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) {
3080 TemplateParameterList *Params = FD->getTemplateParameters();
3081 if (Params->size() == 1)
3084 IsStringTemplate = true;
3088 FoundExactMatch = true;
3090 AllowTemplate = false;
3091 AllowStringTemplate = false;
3092 if (FoundRaw || FoundTemplate || FoundStringTemplate) {
3093 // Go through again and remove the raw and template decls we've
3096 FoundRaw = FoundTemplate = FoundStringTemplate = false;
3098 } else if (AllowRaw && IsRaw) {
3100 } else if (AllowTemplate && IsTemplate) {
3101 FoundTemplate = true;
3102 } else if (AllowStringTemplate && IsStringTemplate) {
3103 FoundStringTemplate = true;
3111 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
3112 // parameter type, that is used in preference to a raw literal operator
3113 // or literal operator template.
3114 if (FoundExactMatch)
3117 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
3118 // operator template, but not both.
3119 if (FoundRaw && FoundTemplate) {
3120 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
3121 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
3122 NoteOverloadCandidate((*I)->getUnderlyingDecl()->getAsFunction());
3130 return LOLR_Template;
3132 if (FoundStringTemplate)
3133 return LOLR_StringTemplate;
3135 // Didn't find anything we could use.
3136 Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
3137 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
3138 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
3139 << (AllowTemplate || AllowStringTemplate);
3143 void ADLResult::insert(NamedDecl *New) {
3144 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
3146 // If we haven't yet seen a decl for this key, or the last decl
3147 // was exactly this one, we're done.
3148 if (Old == nullptr || Old == New) {
3153 // Otherwise, decide which is a more recent redeclaration.
3154 FunctionDecl *OldFD = Old->getAsFunction();
3155 FunctionDecl *NewFD = New->getAsFunction();
3157 FunctionDecl *Cursor = NewFD;
3159 Cursor = Cursor->getPreviousDecl();
3161 // If we got to the end without finding OldFD, OldFD is the newer
3162 // declaration; leave things as they are.
3163 if (!Cursor) return;
3165 // If we do find OldFD, then NewFD is newer.
3166 if (Cursor == OldFD) break;
3168 // Otherwise, keep looking.
3174 void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
3175 ArrayRef<Expr *> Args, ADLResult &Result) {
3176 // Find all of the associated namespaces and classes based on the
3177 // arguments we have.
3178 AssociatedNamespaceSet AssociatedNamespaces;
3179 AssociatedClassSet AssociatedClasses;
3180 FindAssociatedClassesAndNamespaces(Loc, Args,
3181 AssociatedNamespaces,
3184 // C++ [basic.lookup.argdep]p3:
3185 // Let X be the lookup set produced by unqualified lookup (3.4.1)
3186 // and let Y be the lookup set produced by argument dependent
3187 // lookup (defined as follows). If X contains [...] then Y is
3188 // empty. Otherwise Y is the set of declarations found in the
3189 // namespaces associated with the argument types as described
3190 // below. The set of declarations found by the lookup of the name
3191 // is the union of X and Y.
3193 // Here, we compute Y and add its members to the overloaded
3195 for (auto *NS : AssociatedNamespaces) {
3196 // When considering an associated namespace, the lookup is the
3197 // same as the lookup performed when the associated namespace is
3198 // used as a qualifier (3.4.3.2) except that:
3200 // -- Any using-directives in the associated namespace are
3203 // -- Any namespace-scope friend functions declared in
3204 // associated classes are visible within their respective
3205 // namespaces even if they are not visible during an ordinary
3207 DeclContext::lookup_result R = NS->lookup(Name);
3209 // If the only declaration here is an ordinary friend, consider
3210 // it only if it was declared in an associated classes.
3211 if ((D->getIdentifierNamespace() & Decl::IDNS_Ordinary) == 0) {
3212 // If it's neither ordinarily visible nor a friend, we can't find it.
3213 if ((D->getIdentifierNamespace() & Decl::IDNS_OrdinaryFriend) == 0)
3216 bool DeclaredInAssociatedClass = false;
3217 for (Decl *DI = D; DI; DI = DI->getPreviousDecl()) {
3218 DeclContext *LexDC = DI->getLexicalDeclContext();
3219 if (isa<CXXRecordDecl>(LexDC) &&
3220 AssociatedClasses.count(cast<CXXRecordDecl>(LexDC)) &&
3221 isVisible(cast<NamedDecl>(DI))) {
3222 DeclaredInAssociatedClass = true;
3226 if (!DeclaredInAssociatedClass)
3230 if (isa<UsingShadowDecl>(D))
3231 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3233 if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D))
3236 if (!isVisible(D) && !(D = findAcceptableDecl(*this, D)))
3244 //----------------------------------------------------------------------------
3245 // Search for all visible declarations.
3246 //----------------------------------------------------------------------------
3247 VisibleDeclConsumer::~VisibleDeclConsumer() { }
3249 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
3253 class ShadowContextRAII;
3255 class VisibleDeclsRecord {
3257 /// \brief An entry in the shadow map, which is optimized to store a
3258 /// single declaration (the common case) but can also store a list
3259 /// of declarations.
3260 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
3263 /// \brief A mapping from declaration names to the declarations that have
3264 /// this name within a particular scope.
3265 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
3267 /// \brief A list of shadow maps, which is used to model name hiding.
3268 std::list<ShadowMap> ShadowMaps;
3270 /// \brief The declaration contexts we have already visited.
3271 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
3273 friend class ShadowContextRAII;
3276 /// \brief Determine whether we have already visited this context
3277 /// (and, if not, note that we are going to visit that context now).
3278 bool visitedContext(DeclContext *Ctx) {
3279 return !VisitedContexts.insert(Ctx).second;
3282 bool alreadyVisitedContext(DeclContext *Ctx) {
3283 return VisitedContexts.count(Ctx);
3286 /// \brief Determine whether the given declaration is hidden in the
3289 /// \returns the declaration that hides the given declaration, or
3290 /// NULL if no such declaration exists.
3291 NamedDecl *checkHidden(NamedDecl *ND);
3293 /// \brief Add a declaration to the current shadow map.
3294 void add(NamedDecl *ND) {
3295 ShadowMaps.back()[ND->getDeclName()].push_back(ND);
3299 /// \brief RAII object that records when we've entered a shadow context.
3300 class ShadowContextRAII {
3301 VisibleDeclsRecord &Visible;
3303 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
3306 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
3307 Visible.ShadowMaps.emplace_back();
3310 ~ShadowContextRAII() {
3311 Visible.ShadowMaps.pop_back();
3315 } // end anonymous namespace
3317 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
3318 unsigned IDNS = ND->getIdentifierNamespace();
3319 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
3320 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
3321 SM != SMEnd; ++SM) {
3322 ShadowMap::iterator Pos = SM->find(ND->getDeclName());
3323 if (Pos == SM->end())
3326 for (auto *D : Pos->second) {
3327 // A tag declaration does not hide a non-tag declaration.
3328 if (D->hasTagIdentifierNamespace() &&
3329 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
3330 Decl::IDNS_ObjCProtocol)))
3333 // Protocols are in distinct namespaces from everything else.
3334 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
3335 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
3336 D->getIdentifierNamespace() != IDNS)
3339 // Functions and function templates in the same scope overload
3340 // rather than hide. FIXME: Look for hiding based on function
3342 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3343 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3344 SM == ShadowMaps.rbegin())
3347 // We've found a declaration that hides this one.
3355 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
3356 bool QualifiedNameLookup,
3358 VisibleDeclConsumer &Consumer,
3359 VisibleDeclsRecord &Visited) {
3363 // Make sure we don't visit the same context twice.
3364 if (Visited.visitedContext(Ctx->getPrimaryContext()))
3367 // Outside C++, lookup results for the TU live on identifiers.
3368 if (isa<TranslationUnitDecl>(Ctx) &&
3369 !Result.getSema().getLangOpts().CPlusPlus) {
3370 auto &S = Result.getSema();
3371 auto &Idents = S.Context.Idents;
3373 // Ensure all external identifiers are in the identifier table.
3374 if (IdentifierInfoLookup *External = Idents.getExternalIdentifierLookup()) {
3375 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
3376 for (StringRef Name = Iter->Next(); !Name.empty(); Name = Iter->Next())
3380 // Walk all lookup results in the TU for each identifier.
3381 for (const auto &Ident : Idents) {
3382 for (auto I = S.IdResolver.begin(Ident.getValue()),
3383 E = S.IdResolver.end();
3385 if (S.IdResolver.isDeclInScope(*I, Ctx)) {
3386 if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
3387 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3397 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
3398 Result.getSema().ForceDeclarationOfImplicitMembers(Class);
3400 // Enumerate all of the results in this context.
3401 for (DeclContextLookupResult R : Ctx->lookups()) {
3403 if (auto *ND = Result.getAcceptableDecl(D)) {
3404 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3410 // Traverse using directives for qualified name lookup.
3411 if (QualifiedNameLookup) {
3412 ShadowContextRAII Shadow(Visited);
3413 for (auto I : Ctx->using_directives()) {
3414 LookupVisibleDecls(I->getNominatedNamespace(), Result,
3415 QualifiedNameLookup, InBaseClass, Consumer, Visited);
3419 // Traverse the contexts of inherited C++ classes.
3420 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
3421 if (!Record->hasDefinition())
3424 for (const auto &B : Record->bases()) {
3425 QualType BaseType = B.getType();
3427 // Don't look into dependent bases, because name lookup can't look
3429 if (BaseType->isDependentType())
3432 const RecordType *Record = BaseType->getAs<RecordType>();
3436 // FIXME: It would be nice to be able to determine whether referencing
3437 // a particular member would be ambiguous. For example, given
3439 // struct A { int member; };
3440 // struct B { int member; };
3441 // struct C : A, B { };
3443 // void f(C *c) { c->### }
3445 // accessing 'member' would result in an ambiguity. However, we
3446 // could be smart enough to qualify the member with the base
3455 // Find results in this base class (and its bases).
3456 ShadowContextRAII Shadow(Visited);
3457 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup,
3458 true, Consumer, Visited);
3462 // Traverse the contexts of Objective-C classes.
3463 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
3464 // Traverse categories.
3465 for (auto *Cat : IFace->visible_categories()) {
3466 ShadowContextRAII Shadow(Visited);
3467 LookupVisibleDecls(Cat, Result, QualifiedNameLookup, false,
3471 // Traverse protocols.
3472 for (auto *I : IFace->all_referenced_protocols()) {
3473 ShadowContextRAII Shadow(Visited);
3474 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3478 // Traverse the superclass.
3479 if (IFace->getSuperClass()) {
3480 ShadowContextRAII Shadow(Visited);
3481 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup,
3482 true, Consumer, Visited);
3485 // If there is an implementation, traverse it. We do this to find
3486 // synthesized ivars.
3487 if (IFace->getImplementation()) {
3488 ShadowContextRAII Shadow(Visited);
3489 LookupVisibleDecls(IFace->getImplementation(), Result,
3490 QualifiedNameLookup, InBaseClass, Consumer, Visited);
3492 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
3493 for (auto *I : Protocol->protocols()) {
3494 ShadowContextRAII Shadow(Visited);
3495 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3498 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
3499 for (auto *I : Category->protocols()) {
3500 ShadowContextRAII Shadow(Visited);
3501 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3505 // If there is an implementation, traverse it.
3506 if (Category->getImplementation()) {
3507 ShadowContextRAII Shadow(Visited);
3508 LookupVisibleDecls(Category->getImplementation(), Result,
3509 QualifiedNameLookup, true, Consumer, Visited);
3514 static void LookupVisibleDecls(Scope *S, LookupResult &Result,
3515 UnqualUsingDirectiveSet &UDirs,
3516 VisibleDeclConsumer &Consumer,
3517 VisibleDeclsRecord &Visited) {
3521 if (!S->getEntity() ||
3523 !Visited.alreadyVisitedContext(S->getEntity())) ||
3524 (S->getEntity())->isFunctionOrMethod()) {
3525 FindLocalExternScope FindLocals(Result);
3526 // Walk through the declarations in this Scope.
3527 for (auto *D : S->decls()) {
3528 if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
3529 if ((ND = Result.getAcceptableDecl(ND))) {
3530 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
3536 // FIXME: C++ [temp.local]p8
3537 DeclContext *Entity = nullptr;
3538 if (S->getEntity()) {
3539 // Look into this scope's declaration context, along with any of its
3540 // parent lookup contexts (e.g., enclosing classes), up to the point
3541 // where we hit the context stored in the next outer scope.
3542 Entity = S->getEntity();
3543 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME
3545 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
3546 Ctx = Ctx->getLookupParent()) {
3547 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
3548 if (Method->isInstanceMethod()) {
3549 // For instance methods, look for ivars in the method's interface.
3550 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
3551 Result.getNameLoc(), Sema::LookupMemberName);
3552 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
3553 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false,
3554 /*InBaseClass=*/false, Consumer, Visited);
3558 // We've already performed all of the name lookup that we need
3559 // to for Objective-C methods; the next context will be the
3564 if (Ctx->isFunctionOrMethod())
3567 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false,
3568 /*InBaseClass=*/false, Consumer, Visited);
3570 } else if (!S->getParent()) {
3571 // Look into the translation unit scope. We walk through the translation
3572 // unit's declaration context, because the Scope itself won't have all of
3573 // the declarations if we loaded a precompiled header.
3574 // FIXME: We would like the translation unit's Scope object to point to the
3575 // translation unit, so we don't need this special "if" branch. However,
3576 // doing so would force the normal C++ name-lookup code to look into the
3577 // translation unit decl when the IdentifierInfo chains would suffice.
3578 // Once we fix that problem (which is part of a more general "don't look
3579 // in DeclContexts unless we have to" optimization), we can eliminate this.
3580 Entity = Result.getSema().Context.getTranslationUnitDecl();
3581 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false,
3582 /*InBaseClass=*/false, Consumer, Visited);
3586 // Lookup visible declarations in any namespaces found by using
3588 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity))
3589 LookupVisibleDecls(const_cast<DeclContext *>(UUE.getNominatedNamespace()),
3590 Result, /*QualifiedNameLookup=*/false,
3591 /*InBaseClass=*/false, Consumer, Visited);
3594 // Lookup names in the parent scope.
3595 ShadowContextRAII Shadow(Visited);
3596 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited);
3599 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
3600 VisibleDeclConsumer &Consumer,
3601 bool IncludeGlobalScope) {
3602 // Determine the set of using directives available during
3603 // unqualified name lookup.
3605 UnqualUsingDirectiveSet UDirs;
3606 if (getLangOpts().CPlusPlus) {
3607 // Find the first namespace or translation-unit scope.
3608 while (S && !isNamespaceOrTranslationUnitScope(S))
3611 UDirs.visitScopeChain(Initial, S);
3615 // Look for visible declarations.
3616 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3617 Result.setAllowHidden(Consumer.includeHiddenDecls());
3618 VisibleDeclsRecord Visited;
3619 if (!IncludeGlobalScope)
3620 Visited.visitedContext(Context.getTranslationUnitDecl());
3621 ShadowContextRAII Shadow(Visited);
3622 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited);
3625 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
3626 VisibleDeclConsumer &Consumer,
3627 bool IncludeGlobalScope) {
3628 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3629 Result.setAllowHidden(Consumer.includeHiddenDecls());
3630 VisibleDeclsRecord Visited;
3631 if (!IncludeGlobalScope)
3632 Visited.visitedContext(Context.getTranslationUnitDecl());
3633 ShadowContextRAII Shadow(Visited);
3634 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true,
3635 /*InBaseClass=*/false, Consumer, Visited);
3638 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name.
3639 /// If GnuLabelLoc is a valid source location, then this is a definition
3640 /// of an __label__ label name, otherwise it is a normal label definition
3642 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc,
3643 SourceLocation GnuLabelLoc) {
3644 // Do a lookup to see if we have a label with this name already.
3645 NamedDecl *Res = nullptr;
3647 if (GnuLabelLoc.isValid()) {
3648 // Local label definitions always shadow existing labels.
3649 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
3650 Scope *S = CurScope;
3651 PushOnScopeChains(Res, S, true);
3652 return cast<LabelDecl>(Res);
3655 // Not a GNU local label.
3656 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration);
3657 // If we found a label, check to see if it is in the same context as us.
3658 // When in a Block, we don't want to reuse a label in an enclosing function.
3659 if (Res && Res->getDeclContext() != CurContext)
3662 // If not forward referenced or defined already, create the backing decl.
3663 Res = LabelDecl::Create(Context, CurContext, Loc, II);
3664 Scope *S = CurScope->getFnParent();
3665 assert(S && "Not in a function?");
3666 PushOnScopeChains(Res, S, true);
3668 return cast<LabelDecl>(Res);
3671 //===----------------------------------------------------------------------===//
3673 //===----------------------------------------------------------------------===//
3675 static bool isCandidateViable(CorrectionCandidateCallback &CCC,
3676 TypoCorrection &Candidate) {
3677 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
3678 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
3681 static void LookupPotentialTypoResult(Sema &SemaRef,
3683 IdentifierInfo *Name,
3684 Scope *S, CXXScopeSpec *SS,
3685 DeclContext *MemberContext,
3686 bool EnteringContext,
3687 bool isObjCIvarLookup,
3690 /// \brief Check whether the declarations found for a typo correction are
3691 /// visible, and if none of them are, convert the correction to an 'import
3692 /// a module' correction.
3693 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
3694 if (TC.begin() == TC.end())
3697 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
3699 for (/**/; DI != DE; ++DI)
3700 if (!LookupResult::isVisible(SemaRef, *DI))
3702 // Nothing to do if all decls are visible.
3706 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
3707 bool AnyVisibleDecls = !NewDecls.empty();
3709 for (/**/; DI != DE; ++DI) {
3710 NamedDecl *VisibleDecl = *DI;
3711 if (!LookupResult::isVisible(SemaRef, *DI))
3712 VisibleDecl = findAcceptableDecl(SemaRef, *DI);
3715 if (!AnyVisibleDecls) {
3716 // Found a visible decl, discard all hidden ones.
3717 AnyVisibleDecls = true;
3720 NewDecls.push_back(VisibleDecl);
3721 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
3722 NewDecls.push_back(*DI);
3725 if (NewDecls.empty())
3726 TC = TypoCorrection();
3728 TC.setCorrectionDecls(NewDecls);
3729 TC.setRequiresImport(!AnyVisibleDecls);
3733 // Fill the supplied vector with the IdentifierInfo pointers for each piece of
3734 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
3735 // fill the vector with the IdentifierInfo pointers for "foo" and "bar").
3736 static void getNestedNameSpecifierIdentifiers(
3737 NestedNameSpecifier *NNS,
3738 SmallVectorImpl<const IdentifierInfo*> &Identifiers) {
3739 if (NestedNameSpecifier *Prefix = NNS->getPrefix())
3740 getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
3742 Identifiers.clear();
3744 const IdentifierInfo *II = nullptr;
3746 switch (NNS->getKind()) {
3747 case NestedNameSpecifier::Identifier:
3748 II = NNS->getAsIdentifier();
3751 case NestedNameSpecifier::Namespace:
3752 if (NNS->getAsNamespace()->isAnonymousNamespace())
3754 II = NNS->getAsNamespace()->getIdentifier();
3757 case NestedNameSpecifier::NamespaceAlias:
3758 II = NNS->getAsNamespaceAlias()->getIdentifier();
3761 case NestedNameSpecifier::TypeSpecWithTemplate:
3762 case NestedNameSpecifier::TypeSpec:
3763 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier();
3766 case NestedNameSpecifier::Global:
3767 case NestedNameSpecifier::Super:
3772 Identifiers.push_back(II);
3775 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
3776 DeclContext *Ctx, bool InBaseClass) {
3777 // Don't consider hidden names for typo correction.
3781 // Only consider entities with identifiers for names, ignoring
3782 // special names (constructors, overloaded operators, selectors,
3784 IdentifierInfo *Name = ND->getIdentifier();
3788 // Only consider visible declarations and declarations from modules with
3789 // names that exactly match.
3790 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo &&
3791 !findAcceptableDecl(SemaRef, ND))
3794 FoundName(Name->getName());
3797 void TypoCorrectionConsumer::FoundName(StringRef Name) {
3798 // Compute the edit distance between the typo and the name of this
3799 // entity, and add the identifier to the list of results.
3800 addName(Name, nullptr);
3803 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) {
3804 // Compute the edit distance between the typo and this keyword,
3805 // and add the keyword to the list of results.
3806 addName(Keyword, nullptr, nullptr, true);
3809 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
3810 NestedNameSpecifier *NNS, bool isKeyword) {
3811 // Use a simple length-based heuristic to determine the minimum possible
3812 // edit distance. If the minimum isn't good enough, bail out early.
3813 StringRef TypoStr = Typo->getName();
3814 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
3815 if (MinED && TypoStr.size() / MinED < 3)
3818 // Compute an upper bound on the allowable edit distance, so that the
3819 // edit-distance algorithm can short-circuit.
3820 unsigned UpperBound = (TypoStr.size() + 2) / 3 + 1;
3821 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
3822 if (ED >= UpperBound) return;
3824 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
3825 if (isKeyword) TC.makeKeyword();
3826 TC.setCorrectionRange(nullptr, Result.getLookupNameInfo());
3830 static const unsigned MaxTypoDistanceResultSets = 5;
3832 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) {
3833 StringRef TypoStr = Typo->getName();
3834 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
3836 // For very short typos, ignore potential corrections that have a different
3837 // base identifier from the typo or which have a normalized edit distance
3838 // longer than the typo itself.
3839 if (TypoStr.size() < 3 &&
3840 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
3843 // If the correction is resolved but is not viable, ignore it.
3844 if (Correction.isResolved()) {
3845 checkCorrectionVisibility(SemaRef, Correction);
3846 if (!Correction || !isCandidateViable(*CorrectionValidator, Correction))
3850 TypoResultList &CList =
3851 CorrectionResults[Correction.getEditDistance(false)][Name];
3853 if (!CList.empty() && !CList.back().isResolved())
3855 if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
3856 std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts());
3857 for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end();
3858 RI != RIEnd; ++RI) {
3859 // If the Correction refers to a decl already in the result list,
3860 // replace the existing result if the string representation of Correction
3861 // comes before the current result alphabetically, then stop as there is
3862 // nothing more to be done to add Correction to the candidate set.
3863 if (RI->getCorrectionDecl() == NewND) {
3864 if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts()))
3870 if (CList.empty() || Correction.isResolved())
3871 CList.push_back(Correction);
3873 while (CorrectionResults.size() > MaxTypoDistanceResultSets)
3874 CorrectionResults.erase(std::prev(CorrectionResults.end()));
3877 void TypoCorrectionConsumer::addNamespaces(
3878 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
3879 SearchNamespaces = true;
3881 for (auto KNPair : KnownNamespaces)
3882 Namespaces.addNameSpecifier(KNPair.first);
3884 bool SSIsTemplate = false;
3885 if (NestedNameSpecifier *NNS =
3886 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) {
3887 if (const Type *T = NNS->getAsType())
3888 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization;
3890 // Do not transform this into an iterator-based loop. The loop body can
3891 // trigger the creation of further types (through lazy deserialization) and
3892 // invalide iterators into this list.
3893 auto &Types = SemaRef.getASTContext().getTypes();
3894 for (unsigned I = 0; I != Types.size(); ++I) {
3895 const auto *TI = Types[I];
3896 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
3897 CD = CD->getCanonicalDecl();
3898 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
3899 !CD->isUnion() && CD->getIdentifier() &&
3900 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
3901 (CD->isBeingDefined() || CD->isCompleteDefinition()))
3902 Namespaces.addNameSpecifier(CD);
3907 const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() {
3908 if (++CurrentTCIndex < ValidatedCorrections.size())
3909 return ValidatedCorrections[CurrentTCIndex];
3911 CurrentTCIndex = ValidatedCorrections.size();
3912 while (!CorrectionResults.empty()) {
3913 auto DI = CorrectionResults.begin();
3914 if (DI->second.empty()) {
3915 CorrectionResults.erase(DI);
3919 auto RI = DI->second.begin();
3920 if (RI->second.empty()) {
3921 DI->second.erase(RI);
3922 performQualifiedLookups();
3926 TypoCorrection TC = RI->second.pop_back_val();
3927 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) {
3928 ValidatedCorrections.push_back(TC);
3929 return ValidatedCorrections[CurrentTCIndex];
3932 return ValidatedCorrections[0]; // The empty correction.
3935 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
3936 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
3937 DeclContext *TempMemberContext = MemberContext;
3938 CXXScopeSpec *TempSS = SS.get();
3940 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
3942 CorrectionValidator->IsObjCIvarLookup,
3943 Name == Typo && !Candidate.WillReplaceSpecifier());
3944 switch (Result.getResultKind()) {
3945 case LookupResult::NotFound:
3946 case LookupResult::NotFoundInCurrentInstantiation:
3947 case LookupResult::FoundUnresolvedValue:
3949 // Immediately retry the lookup without the given CXXScopeSpec
3951 Candidate.WillReplaceSpecifier(true);
3954 if (TempMemberContext) {
3957 TempMemberContext = nullptr;
3960 if (SearchNamespaces)
3961 QualifiedResults.push_back(Candidate);
3964 case LookupResult::Ambiguous:
3965 // We don't deal with ambiguities.
3968 case LookupResult::Found:
3969 case LookupResult::FoundOverloaded:
3970 // Store all of the Decls for overloaded symbols
3971 for (auto *TRD : Result)
3972 Candidate.addCorrectionDecl(TRD);
3973 checkCorrectionVisibility(SemaRef, Candidate);
3974 if (!isCandidateViable(*CorrectionValidator, Candidate)) {
3975 if (SearchNamespaces)
3976 QualifiedResults.push_back(Candidate);
3979 Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
3985 void TypoCorrectionConsumer::performQualifiedLookups() {
3986 unsigned TypoLen = Typo->getName().size();
3987 for (auto QR : QualifiedResults) {
3988 for (auto NSI : Namespaces) {
3989 DeclContext *Ctx = NSI.DeclCtx;
3990 const Type *NSType = NSI.NameSpecifier->getAsType();
3992 // If the current NestedNameSpecifier refers to a class and the
3993 // current correction candidate is the name of that class, then skip
3994 // it as it is unlikely a qualified version of the class' constructor
3995 // is an appropriate correction.
3996 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() :
3998 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
4002 TypoCorrection TC(QR);
4003 TC.ClearCorrectionDecls();
4004 TC.setCorrectionSpecifier(NSI.NameSpecifier);
4005 TC.setQualifierDistance(NSI.EditDistance);
4006 TC.setCallbackDistance(0); // Reset the callback distance
4008 // If the current correction candidate and namespace combination are
4009 // too far away from the original typo based on the normalized edit
4010 // distance, then skip performing a qualified name lookup.
4011 unsigned TmpED = TC.getEditDistance(true);
4012 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4013 TypoLen / TmpED < 3)
4017 Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4018 if (!SemaRef.LookupQualifiedName(Result, Ctx))
4021 // Any corrections added below will be validated in subsequent
4022 // iterations of the main while() loop over the Consumer's contents.
4023 switch (Result.getResultKind()) {
4024 case LookupResult::Found:
4025 case LookupResult::FoundOverloaded: {
4026 if (SS && SS->isValid()) {
4027 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
4028 std::string OldQualified;
4029 llvm::raw_string_ostream OldOStream(OldQualified);
4030 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy());
4031 OldOStream << Typo->getName();
4032 // If correction candidate would be an identical written qualified
4033 // identifer, then the existing CXXScopeSpec probably included a
4034 // typedef that didn't get accounted for properly.
4035 if (OldOStream.str() == NewQualified)
4038 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4039 TRD != TRDEnd; ++TRD) {
4040 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
4041 NSType ? NSType->getAsCXXRecordDecl()
4043 TRD.getPair()) == Sema::AR_accessible)
4044 TC.addCorrectionDecl(*TRD);
4046 if (TC.isResolved()) {
4047 TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4052 case LookupResult::NotFound:
4053 case LookupResult::NotFoundInCurrentInstantiation:
4054 case LookupResult::Ambiguous:
4055 case LookupResult::FoundUnresolvedValue:
4060 QualifiedResults.clear();
4063 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4064 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4065 : Context(Context), CurContextChain(buildContextChain(CurContext)) {
4066 if (NestedNameSpecifier *NNS =
4067 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) {
4068 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4069 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4071 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
4073 // Build the list of identifiers that would be used for an absolute
4074 // (from the global context) NestedNameSpecifier referring to the current
4076 for (DeclContextList::reverse_iterator C = CurContextChain.rbegin(),
4077 CEnd = CurContextChain.rend();
4079 if (NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(*C))
4080 CurContextIdentifiers.push_back(ND->getIdentifier());
4083 // Add the global context as a NestedNameSpecifier
4084 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
4085 NestedNameSpecifier::GlobalSpecifier(Context), 1};
4086 DistanceMap[1].push_back(SI);
4089 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
4090 DeclContext *Start) -> DeclContextList {
4091 assert(Start && "Building a context chain from a null context");
4092 DeclContextList Chain;
4093 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
4094 DC = DC->getLookupParent()) {
4095 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
4096 if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
4097 !(ND && ND->isAnonymousNamespace()))
4098 Chain.push_back(DC->getPrimaryContext());
4104 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
4105 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) {
4106 unsigned NumSpecifiers = 0;
4107 for (DeclContextList::reverse_iterator C = DeclChain.rbegin(),
4108 CEnd = DeclChain.rend();
4110 if (NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(*C)) {
4111 NNS = NestedNameSpecifier::Create(Context, NNS, ND);
4113 } else if (RecordDecl *RD = dyn_cast_or_null<RecordDecl>(*C)) {
4114 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(),
4115 RD->getTypeForDecl());
4119 return NumSpecifiers;
4122 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
4124 NestedNameSpecifier *NNS = nullptr;
4125 unsigned NumSpecifiers = 0;
4126 DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
4127 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
4129 // Eliminate common elements from the two DeclContext chains.
4130 for (DeclContextList::reverse_iterator C = CurContextChain.rbegin(),
4131 CEnd = CurContextChain.rend();
4132 C != CEnd && !NamespaceDeclChain.empty() &&
4133 NamespaceDeclChain.back() == *C; ++C) {
4134 NamespaceDeclChain.pop_back();
4137 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
4138 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
4140 // Add an explicit leading '::' specifier if needed.
4141 if (NamespaceDeclChain.empty()) {
4142 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4143 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4145 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4146 } else if (NamedDecl *ND =
4147 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
4148 IdentifierInfo *Name = ND->getIdentifier();
4149 bool SameNameSpecifier = false;
4150 if (std::find(CurNameSpecifierIdentifiers.begin(),
4151 CurNameSpecifierIdentifiers.end(),
4152 Name) != CurNameSpecifierIdentifiers.end()) {
4153 std::string NewNameSpecifier;
4154 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
4155 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
4156 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4157 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4158 SpecifierOStream.flush();
4159 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
4161 if (SameNameSpecifier ||
4162 std::find(CurContextIdentifiers.begin(), CurContextIdentifiers.end(),
4163 Name) != CurContextIdentifiers.end()) {
4164 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4165 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4167 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4171 // If the built NestedNameSpecifier would be replacing an existing
4172 // NestedNameSpecifier, use the number of component identifiers that
4173 // would need to be changed as the edit distance instead of the number
4174 // of components in the built NestedNameSpecifier.
4175 if (NNS && !CurNameSpecifierIdentifiers.empty()) {
4176 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
4177 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4178 NumSpecifiers = llvm::ComputeEditDistance(
4179 llvm::makeArrayRef(CurNameSpecifierIdentifiers),
4180 llvm::makeArrayRef(NewNameSpecifierIdentifiers));
4183 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
4184 DistanceMap[NumSpecifiers].push_back(SI);
4187 /// \brief Perform name lookup for a possible result for typo correction.
4188 static void LookupPotentialTypoResult(Sema &SemaRef,
4190 IdentifierInfo *Name,
4191 Scope *S, CXXScopeSpec *SS,
4192 DeclContext *MemberContext,
4193 bool EnteringContext,
4194 bool isObjCIvarLookup,
4196 Res.suppressDiagnostics();
4198 Res.setLookupName(Name);
4199 Res.setAllowHidden(FindHidden);
4200 if (MemberContext) {
4201 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
4202 if (isObjCIvarLookup) {
4203 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
4210 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(Name)) {
4217 SemaRef.LookupQualifiedName(Res, MemberContext);
4221 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
4224 // Fake ivar lookup; this should really be part of
4225 // LookupParsedName.
4226 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
4227 if (Method->isInstanceMethod() && Method->getClassInterface() &&
4229 (Res.isSingleResult() &&
4230 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) {
4231 if (ObjCIvarDecl *IV
4232 = Method->getClassInterface()->lookupInstanceVariable(Name)) {
4240 /// \brief Add keywords to the consumer as possible typo corrections.
4241 static void AddKeywordsToConsumer(Sema &SemaRef,
4242 TypoCorrectionConsumer &Consumer,
4243 Scope *S, CorrectionCandidateCallback &CCC,
4244 bool AfterNestedNameSpecifier) {
4245 if (AfterNestedNameSpecifier) {
4246 // For 'X::', we know exactly which keywords can appear next.
4247 Consumer.addKeywordResult("template");
4248 if (CCC.WantExpressionKeywords)
4249 Consumer.addKeywordResult("operator");
4253 if (CCC.WantObjCSuper)
4254 Consumer.addKeywordResult("super");
4256 if (CCC.WantTypeSpecifiers) {
4257 // Add type-specifier keywords to the set of results.
4258 static const char *const CTypeSpecs[] = {
4259 "char", "const", "double", "enum", "float", "int", "long", "short",
4260 "signed", "struct", "union", "unsigned", "void", "volatile",
4261 "_Complex", "_Imaginary",
4262 // storage-specifiers as well
4263 "extern", "inline", "static", "typedef"
4266 const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs);
4267 for (unsigned I = 0; I != NumCTypeSpecs; ++I)
4268 Consumer.addKeywordResult(CTypeSpecs[I]);
4270 if (SemaRef.getLangOpts().C99)
4271 Consumer.addKeywordResult("restrict");
4272 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
4273 Consumer.addKeywordResult("bool");
4274 else if (SemaRef.getLangOpts().C99)
4275 Consumer.addKeywordResult("_Bool");
4277 if (SemaRef.getLangOpts().CPlusPlus) {
4278 Consumer.addKeywordResult("class");
4279 Consumer.addKeywordResult("typename");
4280 Consumer.addKeywordResult("wchar_t");
4282 if (SemaRef.getLangOpts().CPlusPlus11) {
4283 Consumer.addKeywordResult("char16_t");
4284 Consumer.addKeywordResult("char32_t");
4285 Consumer.addKeywordResult("constexpr");
4286 Consumer.addKeywordResult("decltype");
4287 Consumer.addKeywordResult("thread_local");
4291 if (SemaRef.getLangOpts().GNUMode)
4292 Consumer.addKeywordResult("typeof");
4293 } else if (CCC.WantFunctionLikeCasts) {
4294 static const char *const CastableTypeSpecs[] = {
4295 "char", "double", "float", "int", "long", "short",
4296 "signed", "unsigned", "void"
4298 for (auto *kw : CastableTypeSpecs)
4299 Consumer.addKeywordResult(kw);
4302 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
4303 Consumer.addKeywordResult("const_cast");
4304 Consumer.addKeywordResult("dynamic_cast");
4305 Consumer.addKeywordResult("reinterpret_cast");
4306 Consumer.addKeywordResult("static_cast");
4309 if (CCC.WantExpressionKeywords) {
4310 Consumer.addKeywordResult("sizeof");
4311 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
4312 Consumer.addKeywordResult("false");
4313 Consumer.addKeywordResult("true");
4316 if (SemaRef.getLangOpts().CPlusPlus) {
4317 static const char *const CXXExprs[] = {
4318 "delete", "new", "operator", "throw", "typeid"
4320 const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs);
4321 for (unsigned I = 0; I != NumCXXExprs; ++I)
4322 Consumer.addKeywordResult(CXXExprs[I]);
4324 if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
4325 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
4326 Consumer.addKeywordResult("this");
4328 if (SemaRef.getLangOpts().CPlusPlus11) {
4329 Consumer.addKeywordResult("alignof");
4330 Consumer.addKeywordResult("nullptr");
4334 if (SemaRef.getLangOpts().C11) {
4335 // FIXME: We should not suggest _Alignof if the alignof macro
4337 Consumer.addKeywordResult("_Alignof");
4341 if (CCC.WantRemainingKeywords) {
4342 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
4344 static const char *const CStmts[] = {
4345 "do", "else", "for", "goto", "if", "return", "switch", "while" };
4346 const unsigned NumCStmts = llvm::array_lengthof(CStmts);
4347 for (unsigned I = 0; I != NumCStmts; ++I)
4348 Consumer.addKeywordResult(CStmts[I]);
4350 if (SemaRef.getLangOpts().CPlusPlus) {
4351 Consumer.addKeywordResult("catch");
4352 Consumer.addKeywordResult("try");
4355 if (S && S->getBreakParent())
4356 Consumer.addKeywordResult("break");
4358 if (S && S->getContinueParent())
4359 Consumer.addKeywordResult("continue");
4361 if (!SemaRef.getCurFunction()->SwitchStack.empty()) {
4362 Consumer.addKeywordResult("case");
4363 Consumer.addKeywordResult("default");
4366 if (SemaRef.getLangOpts().CPlusPlus) {
4367 Consumer.addKeywordResult("namespace");
4368 Consumer.addKeywordResult("template");
4371 if (S && S->isClassScope()) {
4372 Consumer.addKeywordResult("explicit");
4373 Consumer.addKeywordResult("friend");
4374 Consumer.addKeywordResult("mutable");
4375 Consumer.addKeywordResult("private");
4376 Consumer.addKeywordResult("protected");
4377 Consumer.addKeywordResult("public");
4378 Consumer.addKeywordResult("virtual");
4382 if (SemaRef.getLangOpts().CPlusPlus) {
4383 Consumer.addKeywordResult("using");
4385 if (SemaRef.getLangOpts().CPlusPlus11)
4386 Consumer.addKeywordResult("static_assert");
4391 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
4392 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4393 Scope *S, CXXScopeSpec *SS,
4394 std::unique_ptr<CorrectionCandidateCallback> CCC,
4395 DeclContext *MemberContext, bool EnteringContext,
4396 const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
4398 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
4399 DisableTypoCorrection)
4402 // In Microsoft mode, don't perform typo correction in a template member
4403 // function dependent context because it interferes with the "lookup into
4404 // dependent bases of class templates" feature.
4405 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
4406 isa<CXXMethodDecl>(CurContext))
4409 // We only attempt to correct typos for identifiers.
4410 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4414 // If the scope specifier itself was invalid, don't try to correct
4416 if (SS && SS->isInvalid())
4419 // Never try to correct typos during template deduction or
4421 if (!ActiveTemplateInstantiations.empty())
4424 // Don't try to correct 'super'.
4425 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
4428 // Abort if typo correction already failed for this specific typo.
4429 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
4430 if (locs != TypoCorrectionFailures.end() &&
4431 locs->second.count(TypoName.getLoc()))
4434 // Don't try to correct the identifier "vector" when in AltiVec mode.
4435 // TODO: Figure out why typo correction misbehaves in this case, fix it, and
4436 // remove this workaround.
4437 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector"))
4440 // Provide a stop gap for files that are just seriously broken. Trying
4441 // to correct all typos can turn into a HUGE performance penalty, causing
4442 // some files to take minutes to get rejected by the parser.
4443 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
4444 if (Limit && TyposCorrected >= Limit)
4448 // If we're handling a missing symbol error, using modules, and the
4449 // special search all modules option is used, look for a missing import.
4450 if (ErrorRecovery && getLangOpts().Modules &&
4451 getLangOpts().ModulesSearchAll) {
4452 // The following has the side effect of loading the missing module.
4453 getModuleLoader().lookupMissingImports(Typo->getName(),
4454 TypoName.getLocStart());
4457 CorrectionCandidateCallback &CCCRef = *CCC;
4458 auto Consumer = llvm::make_unique<TypoCorrectionConsumer>(
4459 *this, TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4462 // Perform name lookup to find visible, similarly-named entities.
4463 bool IsUnqualifiedLookup = false;
4464 DeclContext *QualifiedDC = MemberContext;
4465 if (MemberContext) {
4466 LookupVisibleDecls(MemberContext, LookupKind, *Consumer);
4468 // Look in qualified interfaces.
4470 for (auto *I : OPT->quals())
4471 LookupVisibleDecls(I, LookupKind, *Consumer);
4473 } else if (SS && SS->isSet()) {
4474 QualifiedDC = computeDeclContext(*SS, EnteringContext);
4478 LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer);
4480 IsUnqualifiedLookup = true;
4483 // Determine whether we are going to search in the various namespaces for
4485 bool SearchNamespaces
4486 = getLangOpts().CPlusPlus &&
4487 (IsUnqualifiedLookup || (SS && SS->isSet()));
4489 if (IsUnqualifiedLookup || SearchNamespaces) {
4490 // For unqualified lookup, look through all of the names that we have
4491 // seen in this translation unit.
4492 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4493 for (const auto &I : Context.Idents)
4494 Consumer->FoundName(I.getKey());
4496 // Walk through identifiers in external identifier sources.
4497 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4498 if (IdentifierInfoLookup *External
4499 = Context.Idents.getExternalIdentifierLookup()) {
4500 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4502 StringRef Name = Iter->Next();
4506 Consumer->FoundName(Name);
4511 AddKeywordsToConsumer(*this, *Consumer, S, CCCRef, SS && SS->isNotEmpty());
4513 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
4514 // to search those namespaces.
4515 if (SearchNamespaces) {
4516 // Load any externally-known namespaces.
4517 if (ExternalSource && !LoadedExternalKnownNamespaces) {
4518 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
4519 LoadedExternalKnownNamespaces = true;
4520 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
4521 for (auto *N : ExternalKnownNamespaces)
4522 KnownNamespaces[N] = true;
4525 Consumer->addNamespaces(KnownNamespaces);
4531 /// \brief Try to "correct" a typo in the source code by finding
4532 /// visible declarations whose names are similar to the name that was
4533 /// present in the source code.
4535 /// \param TypoName the \c DeclarationNameInfo structure that contains
4536 /// the name that was present in the source code along with its location.
4538 /// \param LookupKind the name-lookup criteria used to search for the name.
4540 /// \param S the scope in which name lookup occurs.
4542 /// \param SS the nested-name-specifier that precedes the name we're
4543 /// looking for, if present.
4545 /// \param CCC A CorrectionCandidateCallback object that provides further
4546 /// validation of typo correction candidates. It also provides flags for
4547 /// determining the set of keywords permitted.
4549 /// \param MemberContext if non-NULL, the context in which to look for
4550 /// a member access expression.
4552 /// \param EnteringContext whether we're entering the context described by
4553 /// the nested-name-specifier SS.
4555 /// \param OPT when non-NULL, the search for visible declarations will
4556 /// also walk the protocols in the qualified interfaces of \p OPT.
4558 /// \returns a \c TypoCorrection containing the corrected name if the typo
4559 /// along with information such as the \c NamedDecl where the corrected name
4560 /// was declared, and any additional \c NestedNameSpecifier needed to access
4561 /// it (C++ only). The \c TypoCorrection is empty if there is no correction.
4562 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
4563 Sema::LookupNameKind LookupKind,
4564 Scope *S, CXXScopeSpec *SS,
4565 std::unique_ptr<CorrectionCandidateCallback> CCC,
4566 CorrectTypoKind Mode,
4567 DeclContext *MemberContext,
4568 bool EnteringContext,
4569 const ObjCObjectPointerType *OPT,
4570 bool RecordFailure) {
4571 assert(CCC && "CorrectTypo requires a CorrectionCandidateCallback");
4573 // Always let the ExternalSource have the first chance at correction, even
4574 // if we would otherwise have given up.
4575 if (ExternalSource) {
4576 if (TypoCorrection Correction = ExternalSource->CorrectTypo(
4577 TypoName, LookupKind, S, SS, *CCC, MemberContext, EnteringContext, OPT))
4581 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
4582 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
4583 // some instances of CTC_Unknown, while WantRemainingKeywords is true
4584 // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
4585 bool ObjCMessageReceiver = CCC->WantObjCSuper && !CCC->WantRemainingKeywords;
4587 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4588 auto Consumer = makeTypoCorrectionConsumer(
4589 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4590 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4593 return TypoCorrection();
4595 // If we haven't found anything, we're done.
4596 if (Consumer->empty())
4597 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4599 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4600 // is not more that about a third of the length of the typo's identifier.
4601 unsigned ED = Consumer->getBestEditDistance(true);
4602 unsigned TypoLen = Typo->getName().size();
4603 if (ED > 0 && TypoLen / ED < 3)
4604 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4606 TypoCorrection BestTC = Consumer->getNextCorrection();
4607 TypoCorrection SecondBestTC = Consumer->getNextCorrection();
4609 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4611 ED = BestTC.getEditDistance();
4613 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
4614 // If this was an unqualified lookup and we believe the callback
4615 // object wouldn't have filtered out possible corrections, note
4616 // that no correction was found.
4617 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4620 // If only a single name remains, return that result.
4621 if (!SecondBestTC ||
4622 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
4623 const TypoCorrection &Result = BestTC;
4625 // Don't correct to a keyword that's the same as the typo; the keyword
4626 // wasn't actually in scope.
4627 if (ED == 0 && Result.isKeyword())
4628 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4630 TypoCorrection TC = Result;
4631 TC.setCorrectionRange(SS, TypoName);
4632 checkCorrectionVisibility(*this, TC);
4634 } else if (SecondBestTC && ObjCMessageReceiver) {
4635 // Prefer 'super' when we're completing in a message-receiver
4638 if (BestTC.getCorrection().getAsString() != "super") {
4639 if (SecondBestTC.getCorrection().getAsString() == "super")
4640 BestTC = SecondBestTC;
4641 else if ((*Consumer)["super"].front().isKeyword())
4642 BestTC = (*Consumer)["super"].front();
4644 // Don't correct to a keyword that's the same as the typo; the keyword
4645 // wasn't actually in scope.
4646 if (BestTC.getEditDistance() == 0 ||
4647 BestTC.getCorrection().getAsString() != "super")
4648 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4650 BestTC.setCorrectionRange(SS, TypoName);
4654 // Record the failure's location if needed and return an empty correction. If
4655 // this was an unqualified lookup and we believe the callback object did not
4656 // filter out possible corrections, also cache the failure for the typo.
4657 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC);
4660 /// \brief Try to "correct" a typo in the source code by finding
4661 /// visible declarations whose names are similar to the name that was
4662 /// present in the source code.
4664 /// \param TypoName the \c DeclarationNameInfo structure that contains
4665 /// the name that was present in the source code along with its location.
4667 /// \param LookupKind the name-lookup criteria used to search for the name.
4669 /// \param S the scope in which name lookup occurs.
4671 /// \param SS the nested-name-specifier that precedes the name we're
4672 /// looking for, if present.
4674 /// \param CCC A CorrectionCandidateCallback object that provides further
4675 /// validation of typo correction candidates. It also provides flags for
4676 /// determining the set of keywords permitted.
4678 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print
4679 /// diagnostics when the actual typo correction is attempted.
4681 /// \param TRC A TypoRecoveryCallback functor that will be used to build an
4682 /// Expr from a typo correction candidate.
4684 /// \param MemberContext if non-NULL, the context in which to look for
4685 /// a member access expression.
4687 /// \param EnteringContext whether we're entering the context described by
4688 /// the nested-name-specifier SS.
4690 /// \param OPT when non-NULL, the search for visible declarations will
4691 /// also walk the protocols in the qualified interfaces of \p OPT.
4693 /// \returns a new \c TypoExpr that will later be replaced in the AST with an
4694 /// Expr representing the result of performing typo correction, or nullptr if
4695 /// typo correction is not possible. If nullptr is returned, no diagnostics will
4696 /// be emitted and it is the responsibility of the caller to emit any that are
4698 TypoExpr *Sema::CorrectTypoDelayed(
4699 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4700 Scope *S, CXXScopeSpec *SS,
4701 std::unique_ptr<CorrectionCandidateCallback> CCC,
4702 TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode,
4703 DeclContext *MemberContext, bool EnteringContext,
4704 const ObjCObjectPointerType *OPT) {
4705 assert(CCC && "CorrectTypoDelayed requires a CorrectionCandidateCallback");
4707 TypoCorrection Empty;
4708 auto Consumer = makeTypoCorrectionConsumer(
4709 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4710 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4712 if (!Consumer || Consumer->empty())
4715 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4716 // is not more that about a third of the length of the typo's identifier.
4717 unsigned ED = Consumer->getBestEditDistance(true);
4718 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4719 if (ED > 0 && Typo->getName().size() / ED < 3)
4722 ExprEvalContexts.back().NumTypos++;
4723 return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC));
4726 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) {
4730 CorrectionDecls.clear();
4732 CorrectionDecls.push_back(CDecl);
4734 if (!CorrectionName)
4735 CorrectionName = CDecl->getDeclName();
4738 std::string TypoCorrection::getAsString(const LangOptions &LO) const {
4739 if (CorrectionNameSpec) {
4740 std::string tmpBuffer;
4741 llvm::raw_string_ostream PrefixOStream(tmpBuffer);
4742 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO));
4743 PrefixOStream << CorrectionName;
4744 return PrefixOStream.str();
4747 return CorrectionName.getAsString();
4750 bool CorrectionCandidateCallback::ValidateCandidate(
4751 const TypoCorrection &candidate) {
4752 if (!candidate.isResolved())
4755 if (candidate.isKeyword())
4756 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
4757 WantRemainingKeywords || WantObjCSuper;
4759 bool HasNonType = false;
4760 bool HasStaticMethod = false;
4761 bool HasNonStaticMethod = false;
4762 for (Decl *D : candidate) {
4763 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
4764 D = FTD->getTemplatedDecl();
4765 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
4766 if (Method->isStatic())
4767 HasStaticMethod = true;
4769 HasNonStaticMethod = true;
4771 if (!isa<TypeDecl>(D))
4775 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
4776 !candidate.getCorrectionSpecifier())
4779 return WantTypeSpecifiers || HasNonType;
4782 FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs,
4783 bool HasExplicitTemplateArgs,
4785 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
4786 CurContext(SemaRef.CurContext), MemberFn(ME) {
4787 WantTypeSpecifiers = false;
4788 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && NumArgs == 1;
4789 WantRemainingKeywords = false;
4792 bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) {
4793 if (!candidate.getCorrectionDecl())
4794 return candidate.isKeyword();
4796 for (auto *C : candidate) {
4797 FunctionDecl *FD = nullptr;
4798 NamedDecl *ND = C->getUnderlyingDecl();
4799 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
4800 FD = FTD->getTemplatedDecl();
4801 if (!HasExplicitTemplateArgs && !FD) {
4802 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
4803 // If the Decl is neither a function nor a template function,
4804 // determine if it is a pointer or reference to a function. If so,
4805 // check against the number of arguments expected for the pointee.
4806 QualType ValType = cast<ValueDecl>(ND)->getType();
4807 if (ValType->isAnyPointerType() || ValType->isReferenceType())
4808 ValType = ValType->getPointeeType();
4809 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
4810 if (FPT->getNumParams() == NumArgs)
4815 // Skip the current candidate if it is not a FunctionDecl or does not accept
4816 // the current number of arguments.
4817 if (!FD || !(FD->getNumParams() >= NumArgs &&
4818 FD->getMinRequiredArguments() <= NumArgs))
4821 // If the current candidate is a non-static C++ method, skip the candidate
4822 // unless the method being corrected--or the current DeclContext, if the
4823 // function being corrected is not a method--is a method in the same class
4824 // or a descendent class of the candidate's parent class.
4825 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
4826 if (MemberFn || !MD->isStatic()) {
4827 CXXMethodDecl *CurMD =
4829 ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl())
4830 : dyn_cast_or_null<CXXMethodDecl>(CurContext);
4831 CXXRecordDecl *CurRD =
4832 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
4833 CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
4834 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
4843 void Sema::diagnoseTypo(const TypoCorrection &Correction,
4844 const PartialDiagnostic &TypoDiag,
4845 bool ErrorRecovery) {
4846 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
4850 /// Find which declaration we should import to provide the definition of
4851 /// the given declaration.
4852 static NamedDecl *getDefinitionToImport(NamedDecl *D) {
4853 if (VarDecl *VD = dyn_cast<VarDecl>(D))
4854 return VD->getDefinition();
4855 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
4856 return FD->isDefined(FD) ? const_cast<FunctionDecl*>(FD) : nullptr;
4857 if (TagDecl *TD = dyn_cast<TagDecl>(D))
4858 return TD->getDefinition();
4859 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
4860 return ID->getDefinition();
4861 if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
4862 return PD->getDefinition();
4863 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
4864 return getDefinitionToImport(TD->getTemplatedDecl());
4868 void Sema::diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl,
4869 bool NeedDefinition, bool Recover) {
4870 assert(!isVisible(Decl) && "missing import for non-hidden decl?");
4872 // Suggest importing a module providing the definition of this entity, if
4874 NamedDecl *Def = getDefinitionToImport(Decl);
4878 // FIXME: Add a Fix-It that imports the corresponding module or includes
4880 Module *Owner = getOwningModule(Decl);
4881 assert(Owner && "definition of hidden declaration is not in a module");
4883 llvm::SmallVector<Module*, 8> OwningModules;
4884 OwningModules.push_back(Owner);
4885 auto Merged = Context.getModulesWithMergedDefinition(Decl);
4886 OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end());
4888 diagnoseMissingImport(Loc, Decl, Decl->getLocation(), OwningModules,
4889 NeedDefinition ? MissingImportKind::Definition
4890 : MissingImportKind::Declaration,
4894 void Sema::diagnoseMissingImport(SourceLocation UseLoc, NamedDecl *Decl,
4895 SourceLocation DeclLoc,
4896 ArrayRef<Module *> Modules,
4897 MissingImportKind MIK, bool Recover) {
4898 assert(!Modules.empty());
4900 if (Modules.size() > 1) {
4901 std::string ModuleList;
4903 for (Module *M : Modules) {
4904 ModuleList += "\n ";
4905 if (++N == 5 && N != Modules.size()) {
4906 ModuleList += "[...]";
4909 ModuleList += M->getFullModuleName();
4912 Diag(UseLoc, diag::err_module_unimported_use_multiple)
4913 << (int)MIK << Decl << ModuleList;
4915 Diag(UseLoc, diag::err_module_unimported_use)
4916 << (int)MIK << Decl << Modules[0]->getFullModuleName();
4921 case MissingImportKind::Declaration:
4922 DiagID = diag::note_previous_declaration;
4924 case MissingImportKind::Definition:
4925 DiagID = diag::note_previous_definition;
4927 case MissingImportKind::DefaultArgument:
4928 DiagID = diag::note_default_argument_declared_here;
4931 Diag(DeclLoc, DiagID);
4933 // Try to recover by implicitly importing this module.
4935 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
4938 /// \brief Diagnose a successfully-corrected typo. Separated from the correction
4939 /// itself to allow external validation of the result, etc.
4941 /// \param Correction The result of performing typo correction.
4942 /// \param TypoDiag The diagnostic to produce. This will have the corrected
4943 /// string added to it (and usually also a fixit).
4944 /// \param PrevNote A note to use when indicating the location of the entity to
4945 /// which we are correcting. Will have the correction string added to it.
4946 /// \param ErrorRecovery If \c true (the default), the caller is going to
4947 /// recover from the typo as if the corrected string had been typed.
4948 /// In this case, \c PDiag must be an error, and we will attach a fixit
4950 void Sema::diagnoseTypo(const TypoCorrection &Correction,
4951 const PartialDiagnostic &TypoDiag,
4952 const PartialDiagnostic &PrevNote,
4953 bool ErrorRecovery) {
4954 std::string CorrectedStr = Correction.getAsString(getLangOpts());
4955 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
4956 FixItHint FixTypo = FixItHint::CreateReplacement(
4957 Correction.getCorrectionRange(), CorrectedStr);
4959 // Maybe we're just missing a module import.
4960 if (Correction.requiresImport()) {
4961 NamedDecl *Decl = Correction.getFoundDecl();
4962 assert(Decl && "import required but no declaration to import");
4964 diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl,
4965 /*NeedDefinition*/ false, ErrorRecovery);
4969 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
4970 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
4972 NamedDecl *ChosenDecl =
4973 Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
4974 if (PrevNote.getDiagID() && ChosenDecl)
4975 Diag(ChosenDecl->getLocation(), PrevNote)
4976 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
4979 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
4980 TypoDiagnosticGenerator TDG,
4981 TypoRecoveryCallback TRC) {
4982 assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer");
4983 auto TE = new (Context) TypoExpr(Context.DependentTy);
4984 auto &State = DelayedTypos[TE];
4985 State.Consumer = std::move(TCC);
4986 State.DiagHandler = std::move(TDG);
4987 State.RecoveryHandler = std::move(TRC);
4991 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const {
4992 auto Entry = DelayedTypos.find(TE);
4993 assert(Entry != DelayedTypos.end() &&
4994 "Failed to get the state for a TypoExpr!");
4995 return Entry->second;
4998 void Sema::clearDelayedTypo(TypoExpr *TE) {
4999 DelayedTypos.erase(TE);
5002 void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) {
5003 DeclarationNameInfo Name(II, IILoc);
5004 LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration);
5005 R.suppressDiagnostics();
5006 R.setHideTags(false);