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 /// \brief Lookup a builtin function, when name lookup would otherwise
655 static bool LookupBuiltin(Sema &S, LookupResult &R) {
656 Sema::LookupNameKind NameKind = R.getLookupKind();
658 // If we didn't find a use of this identifier, and if the identifier
659 // corresponds to a compiler builtin, create the decl object for the builtin
660 // now, injecting it into translation unit scope, and return it.
661 if (NameKind == Sema::LookupOrdinaryName ||
662 NameKind == Sema::LookupRedeclarationWithLinkage) {
663 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo();
665 if (S.getLangOpts().CPlusPlus11 && S.getLangOpts().GNUMode &&
666 II == S.getFloat128Identifier()) {
667 // libstdc++4.7's type_traits expects type __float128 to exist, so
668 // insert a dummy type to make that header build in gnu++11 mode.
669 R.addDecl(S.getASTContext().getFloat128StubType());
672 if (S.getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName &&
673 II == S.getASTContext().getMakeIntegerSeqName()) {
674 R.addDecl(S.getASTContext().getMakeIntegerSeqDecl());
678 // If this is a builtin on this (or all) targets, create the decl.
679 if (unsigned BuiltinID = II->getBuiltinID()) {
680 // In C++, we don't have any predefined library functions like
681 // 'malloc'. Instead, we'll just error.
682 if (S.getLangOpts().CPlusPlus &&
683 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
686 if (NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II,
687 BuiltinID, S.TUScope,
688 R.isForRedeclaration(),
700 /// \brief Determine whether we can declare a special member function within
701 /// the class at this point.
702 static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) {
703 // We need to have a definition for the class.
704 if (!Class->getDefinition() || Class->isDependentContext())
707 // We can't be in the middle of defining the class.
708 return !Class->isBeingDefined();
711 void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) {
712 if (!CanDeclareSpecialMemberFunction(Class))
715 // If the default constructor has not yet been declared, do so now.
716 if (Class->needsImplicitDefaultConstructor())
717 DeclareImplicitDefaultConstructor(Class);
719 // If the copy constructor has not yet been declared, do so now.
720 if (Class->needsImplicitCopyConstructor())
721 DeclareImplicitCopyConstructor(Class);
723 // If the copy assignment operator has not yet been declared, do so now.
724 if (Class->needsImplicitCopyAssignment())
725 DeclareImplicitCopyAssignment(Class);
727 if (getLangOpts().CPlusPlus11) {
728 // If the move constructor has not yet been declared, do so now.
729 if (Class->needsImplicitMoveConstructor())
730 DeclareImplicitMoveConstructor(Class); // might not actually do it
732 // If the move assignment operator has not yet been declared, do so now.
733 if (Class->needsImplicitMoveAssignment())
734 DeclareImplicitMoveAssignment(Class); // might not actually do it
737 // If the destructor has not yet been declared, do so now.
738 if (Class->needsImplicitDestructor())
739 DeclareImplicitDestructor(Class);
742 /// \brief Determine whether this is the name of an implicitly-declared
743 /// special member function.
744 static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) {
745 switch (Name.getNameKind()) {
746 case DeclarationName::CXXConstructorName:
747 case DeclarationName::CXXDestructorName:
750 case DeclarationName::CXXOperatorName:
751 return Name.getCXXOverloadedOperator() == OO_Equal;
760 /// \brief If there are any implicit member functions with the given name
761 /// that need to be declared in the given declaration context, do so.
762 static void DeclareImplicitMemberFunctionsWithName(Sema &S,
763 DeclarationName Name,
764 const DeclContext *DC) {
768 switch (Name.getNameKind()) {
769 case DeclarationName::CXXConstructorName:
770 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
771 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
772 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
773 if (Record->needsImplicitDefaultConstructor())
774 S.DeclareImplicitDefaultConstructor(Class);
775 if (Record->needsImplicitCopyConstructor())
776 S.DeclareImplicitCopyConstructor(Class);
777 if (S.getLangOpts().CPlusPlus11 &&
778 Record->needsImplicitMoveConstructor())
779 S.DeclareImplicitMoveConstructor(Class);
783 case DeclarationName::CXXDestructorName:
784 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
785 if (Record->getDefinition() && Record->needsImplicitDestructor() &&
786 CanDeclareSpecialMemberFunction(Record))
787 S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record));
790 case DeclarationName::CXXOperatorName:
791 if (Name.getCXXOverloadedOperator() != OO_Equal)
794 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) {
795 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
796 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
797 if (Record->needsImplicitCopyAssignment())
798 S.DeclareImplicitCopyAssignment(Class);
799 if (S.getLangOpts().CPlusPlus11 &&
800 Record->needsImplicitMoveAssignment())
801 S.DeclareImplicitMoveAssignment(Class);
811 // Adds all qualifying matches for a name within a decl context to the
812 // given lookup result. Returns true if any matches were found.
813 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
816 // Lazily declare C++ special member functions.
817 if (S.getLangOpts().CPlusPlus)
818 DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), DC);
820 // Perform lookup into this declaration context.
821 DeclContext::lookup_result DR = DC->lookup(R.getLookupName());
822 for (DeclContext::lookup_iterator I = DR.begin(), E = DR.end(); I != E;
825 if ((D = R.getAcceptableDecl(D))) {
831 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R))
834 if (R.getLookupName().getNameKind()
835 != DeclarationName::CXXConversionFunctionName ||
836 R.getLookupName().getCXXNameType()->isDependentType() ||
837 !isa<CXXRecordDecl>(DC))
841 // A specialization of a conversion function template is not found by
842 // name lookup. Instead, any conversion function templates visible in the
843 // context of the use are considered. [...]
844 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
845 if (!Record->isCompleteDefinition())
848 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(),
849 UEnd = Record->conversion_end(); U != UEnd; ++U) {
850 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
854 // When we're performing lookup for the purposes of redeclaration, just
855 // add the conversion function template. When we deduce template
856 // arguments for specializations, we'll end up unifying the return
857 // type of the new declaration with the type of the function template.
858 if (R.isForRedeclaration()) {
859 R.addDecl(ConvTemplate);
865 // [...] For each such operator, if argument deduction succeeds
866 // (14.9.2.3), the resulting specialization is used as if found by
869 // When referencing a conversion function for any purpose other than
870 // a redeclaration (such that we'll be building an expression with the
871 // result), perform template argument deduction and place the
872 // specialization into the result set. We do this to avoid forcing all
873 // callers to perform special deduction for conversion functions.
874 TemplateDeductionInfo Info(R.getNameLoc());
875 FunctionDecl *Specialization = nullptr;
877 const FunctionProtoType *ConvProto
878 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
879 assert(ConvProto && "Nonsensical conversion function template type");
881 // Compute the type of the function that we would expect the conversion
882 // function to have, if it were to match the name given.
883 // FIXME: Calling convention!
884 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo();
885 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C);
886 EPI.ExceptionSpec = EST_None;
887 QualType ExpectedType
888 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(),
891 // Perform template argument deduction against the type that we would
892 // expect the function to have.
893 if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType,
894 Specialization, Info)
895 == Sema::TDK_Success) {
896 R.addDecl(Specialization);
904 // Performs C++ unqualified lookup into the given file context.
906 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context,
907 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
909 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
911 // Perform direct name lookup into the LookupCtx.
912 bool Found = LookupDirect(S, R, NS);
914 // Perform direct name lookup into the namespaces nominated by the
915 // using directives whose common ancestor is this namespace.
916 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS))
917 if (LookupDirect(S, R, UUE.getNominatedNamespace()))
925 static bool isNamespaceOrTranslationUnitScope(Scope *S) {
926 if (DeclContext *Ctx = S->getEntity())
927 return Ctx->isFileContext();
931 // Find the next outer declaration context from this scope. This
932 // routine actually returns the semantic outer context, which may
933 // differ from the lexical context (encoded directly in the Scope
934 // stack) when we are parsing a member of a class template. In this
935 // case, the second element of the pair will be true, to indicate that
936 // name lookup should continue searching in this semantic context when
937 // it leaves the current template parameter scope.
938 static std::pair<DeclContext *, bool> findOuterContext(Scope *S) {
939 DeclContext *DC = S->getEntity();
940 DeclContext *Lexical = nullptr;
941 for (Scope *OuterS = S->getParent(); OuterS;
942 OuterS = OuterS->getParent()) {
943 if (OuterS->getEntity()) {
944 Lexical = OuterS->getEntity();
949 // C++ [temp.local]p8:
950 // In the definition of a member of a class template that appears
951 // outside of the namespace containing the class template
952 // definition, the name of a template-parameter hides the name of
953 // a member of this namespace.
960 // template<class T> class B {
965 // template<class C> void N::B<C>::f(C) {
966 // C b; // C is the template parameter, not N::C
969 // In this example, the lexical context we return is the
970 // TranslationUnit, while the semantic context is the namespace N.
971 if (!Lexical || !DC || !S->getParent() ||
972 !S->getParent()->isTemplateParamScope())
973 return std::make_pair(Lexical, false);
975 // Find the outermost template parameter scope.
976 // For the example, this is the scope for the template parameters of
977 // template<class C>.
978 Scope *OutermostTemplateScope = S->getParent();
979 while (OutermostTemplateScope->getParent() &&
980 OutermostTemplateScope->getParent()->isTemplateParamScope())
981 OutermostTemplateScope = OutermostTemplateScope->getParent();
983 // Find the namespace context in which the original scope occurs. In
984 // the example, this is namespace N.
985 DeclContext *Semantic = DC;
986 while (!Semantic->isFileContext())
987 Semantic = Semantic->getParent();
989 // Find the declaration context just outside of the template
990 // parameter scope. This is the context in which the template is
991 // being lexically declaration (a namespace context). In the
992 // example, this is the global scope.
993 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) &&
994 Lexical->Encloses(Semantic))
995 return std::make_pair(Semantic, true);
997 return std::make_pair(Lexical, false);
1001 /// An RAII object to specify that we want to find block scope extern
1003 struct FindLocalExternScope {
1004 FindLocalExternScope(LookupResult &R)
1005 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
1006 Decl::IDNS_LocalExtern) {
1007 R.setFindLocalExtern(R.getIdentifierNamespace() & Decl::IDNS_Ordinary);
1010 R.setFindLocalExtern(OldFindLocalExtern);
1012 ~FindLocalExternScope() {
1016 bool OldFindLocalExtern;
1018 } // end anonymous namespace
1020 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
1021 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
1023 DeclarationName Name = R.getLookupName();
1024 Sema::LookupNameKind NameKind = R.getLookupKind();
1026 // If this is the name of an implicitly-declared special member function,
1027 // go through the scope stack to implicitly declare
1028 if (isImplicitlyDeclaredMemberFunctionName(Name)) {
1029 for (Scope *PreS = S; PreS; PreS = PreS->getParent())
1030 if (DeclContext *DC = PreS->getEntity())
1031 DeclareImplicitMemberFunctionsWithName(*this, Name, DC);
1034 // Implicitly declare member functions with the name we're looking for, if in
1035 // fact we are in a scope where it matters.
1038 IdentifierResolver::iterator
1039 I = IdResolver.begin(Name),
1040 IEnd = IdResolver.end();
1042 // First we lookup local scope.
1043 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
1044 // ...During unqualified name lookup (3.4.1), the names appear as if
1045 // they were declared in the nearest enclosing namespace which contains
1046 // both the using-directive and the nominated namespace.
1047 // [Note: in this context, "contains" means "contains directly or
1051 // namespace A { int i; }
1055 // using namespace A;
1056 // ++i; // finds local 'i', A::i appears at global scope
1060 UnqualUsingDirectiveSet UDirs;
1061 bool VisitedUsingDirectives = false;
1062 bool LeftStartingScope = false;
1063 DeclContext *OutsideOfTemplateParamDC = nullptr;
1065 // When performing a scope lookup, we want to find local extern decls.
1066 FindLocalExternScope FindLocals(R);
1068 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
1069 DeclContext *Ctx = S->getEntity();
1071 // Check whether the IdResolver has anything in this scope.
1073 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1074 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1075 if (NameKind == LookupRedeclarationWithLinkage) {
1076 // Determine whether this (or a previous) declaration is
1078 if (!LeftStartingScope && !Initial->isDeclScope(*I))
1079 LeftStartingScope = true;
1081 // If we found something outside of our starting scope that
1082 // does not have linkage, skip it. If it's a template parameter,
1083 // we still find it, so we can diagnose the invalid redeclaration.
1084 if (LeftStartingScope && !((*I)->hasLinkage()) &&
1085 !(*I)->isTemplateParameter()) {
1097 if (S->isClassScope())
1098 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx))
1099 R.setNamingClass(Record);
1103 if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
1104 // C++11 [class.friend]p11:
1105 // If a friend declaration appears in a local class and the name
1106 // specified is an unqualified name, a prior declaration is
1107 // looked up without considering scopes that are outside the
1108 // innermost enclosing non-class scope.
1112 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1113 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1114 // We've just searched the last template parameter scope and
1115 // found nothing, so look into the contexts between the
1116 // lexical and semantic declaration contexts returned by
1117 // findOuterContext(). This implements the name lookup behavior
1118 // of C++ [temp.local]p8.
1119 Ctx = OutsideOfTemplateParamDC;
1120 OutsideOfTemplateParamDC = nullptr;
1124 DeclContext *OuterCtx;
1125 bool SearchAfterTemplateScope;
1126 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1127 if (SearchAfterTemplateScope)
1128 OutsideOfTemplateParamDC = OuterCtx;
1130 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1131 // We do not directly look into transparent contexts, since
1132 // those entities will be found in the nearest enclosing
1133 // non-transparent context.
1134 if (Ctx->isTransparentContext())
1137 // We do not look directly into function or method contexts,
1138 // since all of the local variables and parameters of the
1139 // function/method are present within the Scope.
1140 if (Ctx->isFunctionOrMethod()) {
1141 // If we have an Objective-C instance method, look for ivars
1142 // in the corresponding interface.
1143 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
1144 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
1145 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
1146 ObjCInterfaceDecl *ClassDeclared;
1147 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
1148 Name.getAsIdentifierInfo(),
1150 if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
1162 // If this is a file context, we need to perform unqualified name
1163 // lookup considering using directives.
1164 if (Ctx->isFileContext()) {
1165 // If we haven't handled using directives yet, do so now.
1166 if (!VisitedUsingDirectives) {
1167 // Add using directives from this context up to the top level.
1168 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
1169 if (UCtx->isTransparentContext())
1172 UDirs.visit(UCtx, UCtx);
1175 // Find the innermost file scope, so we can add using directives
1176 // from local scopes.
1177 Scope *InnermostFileScope = S;
1178 while (InnermostFileScope &&
1179 !isNamespaceOrTranslationUnitScope(InnermostFileScope))
1180 InnermostFileScope = InnermostFileScope->getParent();
1181 UDirs.visitScopeChain(Initial, InnermostFileScope);
1185 VisitedUsingDirectives = true;
1188 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
1196 // Perform qualified name lookup into this context.
1197 // FIXME: In some cases, we know that every name that could be found by
1198 // this qualified name lookup will also be on the identifier chain. For
1199 // example, inside a class without any base classes, we never need to
1200 // perform qualified lookup because all of the members are on top of the
1201 // identifier chain.
1202 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
1208 // Stop if we ran out of scopes.
1209 // FIXME: This really, really shouldn't be happening.
1210 if (!S) return false;
1212 // If we are looking for members, no need to look into global/namespace scope.
1213 if (NameKind == LookupMemberName)
1216 // Collect UsingDirectiveDecls in all scopes, and recursively all
1217 // nominated namespaces by those using-directives.
1219 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
1220 // don't build it for each lookup!
1221 if (!VisitedUsingDirectives) {
1222 UDirs.visitScopeChain(Initial, S);
1226 // If we're not performing redeclaration lookup, do not look for local
1227 // extern declarations outside of a function scope.
1228 if (!R.isForRedeclaration())
1229 FindLocals.restore();
1231 // Lookup namespace scope, and global scope.
1232 // Unqualified name lookup in C++ requires looking into scopes
1233 // that aren't strictly lexical, and therefore we walk through the
1234 // context as well as walking through the scopes.
1235 for (; S; S = S->getParent()) {
1236 // Check whether the IdResolver has anything in this scope.
1238 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1239 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1240 // We found something. Look for anything else in our scope
1241 // with this same name and in an acceptable identifier
1242 // namespace, so that we can construct an overload set if we
1249 if (Found && S->isTemplateParamScope()) {
1254 DeclContext *Ctx = S->getEntity();
1255 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1256 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1257 // We've just searched the last template parameter scope and
1258 // found nothing, so look into the contexts between the
1259 // lexical and semantic declaration contexts returned by
1260 // findOuterContext(). This implements the name lookup behavior
1261 // of C++ [temp.local]p8.
1262 Ctx = OutsideOfTemplateParamDC;
1263 OutsideOfTemplateParamDC = nullptr;
1267 DeclContext *OuterCtx;
1268 bool SearchAfterTemplateScope;
1269 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1270 if (SearchAfterTemplateScope)
1271 OutsideOfTemplateParamDC = OuterCtx;
1273 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1274 // We do not directly look into transparent contexts, since
1275 // those entities will be found in the nearest enclosing
1276 // non-transparent context.
1277 if (Ctx->isTransparentContext())
1280 // If we have a context, and it's not a context stashed in the
1281 // template parameter scope for an out-of-line definition, also
1282 // look into that context.
1283 if (!(Found && S && S->isTemplateParamScope())) {
1284 assert(Ctx->isFileContext() &&
1285 "We should have been looking only at file context here already.");
1287 // Look into context considering using-directives.
1288 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
1297 if (R.isForRedeclaration() && !Ctx->isTransparentContext())
1302 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
1309 /// \brief Find the declaration that a class temploid member specialization was
1310 /// instantiated from, or the member itself if it is an explicit specialization.
1311 static Decl *getInstantiatedFrom(Decl *D, MemberSpecializationInfo *MSInfo) {
1312 return MSInfo->isExplicitSpecialization() ? D : MSInfo->getInstantiatedFrom();
1315 Module *Sema::getOwningModule(Decl *Entity) {
1316 // If it's imported, grab its owning module.
1317 Module *M = Entity->getImportedOwningModule();
1318 if (M || !isa<NamedDecl>(Entity) || !cast<NamedDecl>(Entity)->isHidden())
1320 assert(!Entity->isFromASTFile() &&
1321 "hidden entity from AST file has no owning module");
1323 if (!getLangOpts().ModulesLocalVisibility) {
1324 // If we're not tracking visibility locally, the only way a declaration
1325 // can be hidden and local is if it's hidden because it's parent is (for
1326 // instance, maybe this is a lazily-declared special member of an imported
1328 auto *Parent = cast<NamedDecl>(Entity->getDeclContext());
1329 assert(Parent->isHidden() && "unexpectedly hidden decl");
1330 return getOwningModule(Parent);
1333 // It's local and hidden; grab or compute its owning module.
1334 M = Entity->getLocalOwningModule();
1338 if (auto *Containing =
1339 PP.getModuleContainingLocation(Entity->getLocation())) {
1341 } else if (Entity->isInvalidDecl() || Entity->getLocation().isInvalid()) {
1342 // Don't bother tracking visibility for invalid declarations with broken
1344 cast<NamedDecl>(Entity)->setHidden(false);
1346 // We need to assign a module to an entity that exists outside of any
1347 // module, so that we can hide it from modules that we textually enter.
1348 // Invent a fake module for all such entities.
1349 if (!CachedFakeTopLevelModule) {
1350 CachedFakeTopLevelModule =
1351 PP.getHeaderSearchInfo().getModuleMap().findOrCreateModule(
1352 "<top-level>", nullptr, false, false).first;
1354 auto &SrcMgr = PP.getSourceManager();
1355 SourceLocation StartLoc =
1356 SrcMgr.getLocForStartOfFile(SrcMgr.getMainFileID());
1358 VisibleModulesStack.empty() ? VisibleModules : VisibleModulesStack[0];
1359 TopLevel.setVisible(CachedFakeTopLevelModule, StartLoc);
1362 M = CachedFakeTopLevelModule;
1366 Entity->setLocalOwningModule(M);
1370 void Sema::makeMergedDefinitionVisible(NamedDecl *ND, SourceLocation Loc) {
1371 if (auto *M = PP.getModuleContainingLocation(Loc))
1372 Context.mergeDefinitionIntoModule(ND, M);
1374 // We're not building a module; just make the definition visible.
1375 ND->setHidden(false);
1377 // If ND is a template declaration, make the template parameters
1378 // visible too. They're not (necessarily) within a mergeable DeclContext.
1379 if (auto *TD = dyn_cast<TemplateDecl>(ND))
1380 for (auto *Param : *TD->getTemplateParameters())
1381 makeMergedDefinitionVisible(Param, Loc);
1384 /// \brief Find the module in which the given declaration was defined.
1385 static Module *getDefiningModule(Sema &S, Decl *Entity) {
1386 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
1387 // If this function was instantiated from a template, the defining module is
1388 // the module containing the pattern.
1389 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1391 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
1392 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1394 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
1395 if (MemberSpecializationInfo *MSInfo = ED->getMemberSpecializationInfo())
1396 Entity = getInstantiatedFrom(ED, MSInfo);
1397 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
1398 // FIXME: Map from variable template specializations back to the template.
1399 if (MemberSpecializationInfo *MSInfo = VD->getMemberSpecializationInfo())
1400 Entity = getInstantiatedFrom(VD, MSInfo);
1403 // Walk up to the containing context. That might also have been instantiated
1405 DeclContext *Context = Entity->getDeclContext();
1406 if (Context->isFileContext())
1407 return S.getOwningModule(Entity);
1408 return getDefiningModule(S, cast<Decl>(Context));
1411 llvm::DenseSet<Module*> &Sema::getLookupModules() {
1412 unsigned N = ActiveTemplateInstantiations.size();
1413 for (unsigned I = ActiveTemplateInstantiationLookupModules.size();
1416 getDefiningModule(*this, ActiveTemplateInstantiations[I].Entity);
1417 if (M && !LookupModulesCache.insert(M).second)
1419 ActiveTemplateInstantiationLookupModules.push_back(M);
1421 return LookupModulesCache;
1424 bool Sema::hasVisibleMergedDefinition(NamedDecl *Def) {
1425 for (Module *Merged : Context.getModulesWithMergedDefinition(Def))
1426 if (isModuleVisible(Merged))
1431 template<typename ParmDecl>
1433 hasVisibleDefaultArgument(Sema &S, const ParmDecl *D,
1434 llvm::SmallVectorImpl<Module *> *Modules) {
1435 if (!D->hasDefaultArgument())
1439 auto &DefaultArg = D->getDefaultArgStorage();
1440 if (!DefaultArg.isInherited() && S.isVisible(D))
1443 if (!DefaultArg.isInherited() && Modules) {
1444 auto *NonConstD = const_cast<ParmDecl*>(D);
1445 Modules->push_back(S.getOwningModule(NonConstD));
1446 const auto &Merged = S.Context.getModulesWithMergedDefinition(NonConstD);
1447 Modules->insert(Modules->end(), Merged.begin(), Merged.end());
1450 // If there was a previous default argument, maybe its parameter is visible.
1451 D = DefaultArg.getInheritedFrom();
1456 bool Sema::hasVisibleDefaultArgument(const NamedDecl *D,
1457 llvm::SmallVectorImpl<Module *> *Modules) {
1458 if (auto *P = dyn_cast<TemplateTypeParmDecl>(D))
1459 return ::hasVisibleDefaultArgument(*this, P, Modules);
1460 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D))
1461 return ::hasVisibleDefaultArgument(*this, P, Modules);
1462 return ::hasVisibleDefaultArgument(*this, cast<TemplateTemplateParmDecl>(D),
1466 /// \brief Determine whether a declaration is visible to name lookup.
1468 /// This routine determines whether the declaration D is visible in the current
1469 /// lookup context, taking into account the current template instantiation
1470 /// stack. During template instantiation, a declaration is visible if it is
1471 /// visible from a module containing any entity on the template instantiation
1472 /// path (by instantiating a template, you allow it to see the declarations that
1473 /// your module can see, including those later on in your module).
1474 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
1475 assert(D->isHidden() && "should not call this: not in slow case");
1476 Module *DeclModule = nullptr;
1478 if (SemaRef.getLangOpts().ModulesLocalVisibility) {
1479 DeclModule = SemaRef.getOwningModule(D);
1481 // getOwningModule() may have decided the declaration should not be hidden.
1482 assert(!D->isHidden() && "hidden decl not from a module");
1486 // If the owning module is visible, and the decl is not module private,
1487 // then the decl is visible too. (Module private is ignored within the same
1488 // top-level module.)
1489 if ((!D->isFromASTFile() || !D->isModulePrivate()) &&
1490 (SemaRef.isModuleVisible(DeclModule) ||
1491 SemaRef.hasVisibleMergedDefinition(D)))
1495 // If this declaration is not at namespace scope nor module-private,
1496 // then it is visible if its lexical parent has a visible definition.
1497 DeclContext *DC = D->getLexicalDeclContext();
1498 if (!D->isModulePrivate() &&
1499 DC && !DC->isFileContext() && !isa<LinkageSpecDecl>(DC)) {
1500 // For a parameter, check whether our current template declaration's
1501 // lexical context is visible, not whether there's some other visible
1502 // definition of it, because parameters aren't "within" the definition.
1503 if ((D->isTemplateParameter() || isa<ParmVarDecl>(D))
1504 ? isVisible(SemaRef, cast<NamedDecl>(DC))
1505 : SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC))) {
1506 if (SemaRef.ActiveTemplateInstantiations.empty() &&
1507 // FIXME: Do something better in this case.
1508 !SemaRef.getLangOpts().ModulesLocalVisibility) {
1509 // Cache the fact that this declaration is implicitly visible because
1510 // its parent has a visible definition.
1511 D->setHidden(false);
1518 // Find the extra places where we need to look.
1519 llvm::DenseSet<Module*> &LookupModules = SemaRef.getLookupModules();
1520 if (LookupModules.empty())
1524 DeclModule = SemaRef.getOwningModule(D);
1525 assert(DeclModule && "hidden decl not from a module");
1528 // If our lookup set contains the decl's module, it's visible.
1529 if (LookupModules.count(DeclModule))
1532 // If the declaration isn't exported, it's not visible in any other module.
1533 if (D->isModulePrivate())
1536 // Check whether DeclModule is transitively exported to an import of
1538 return std::any_of(LookupModules.begin(), LookupModules.end(),
1539 [&](Module *M) { return M->isModuleVisible(DeclModule); });
1542 bool Sema::isVisibleSlow(const NamedDecl *D) {
1543 return LookupResult::isVisible(*this, const_cast<NamedDecl*>(D));
1546 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
1551 return New->isExternallyVisible();
1554 /// \brief Retrieve the visible declaration corresponding to D, if any.
1556 /// This routine determines whether the declaration D is visible in the current
1557 /// module, with the current imports. If not, it checks whether any
1558 /// redeclaration of D is visible, and if so, returns that declaration.
1560 /// \returns D, or a visible previous declaration of D, whichever is more recent
1561 /// and visible. If no declaration of D is visible, returns null.
1562 static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D) {
1563 assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case");
1565 for (auto RD : D->redecls()) {
1566 if (auto ND = dyn_cast<NamedDecl>(RD)) {
1567 // FIXME: This is wrong in the case where the previous declaration is not
1568 // visible in the same scope as D. This needs to be done much more
1570 if (LookupResult::isVisible(SemaRef, ND))
1578 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
1579 return findAcceptableDecl(getSema(), D);
1582 /// @brief Perform unqualified name lookup starting from a given
1585 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
1586 /// used to find names within the current scope. For example, 'x' in
1590 /// return x; // unqualified name look finds 'x' in the global scope
1594 /// Different lookup criteria can find different names. For example, a
1595 /// particular scope can have both a struct and a function of the same
1596 /// name, and each can be found by certain lookup criteria. For more
1597 /// information about lookup criteria, see the documentation for the
1598 /// class LookupCriteria.
1600 /// @param S The scope from which unqualified name lookup will
1601 /// begin. If the lookup criteria permits, name lookup may also search
1602 /// in the parent scopes.
1604 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to
1605 /// look up and the lookup kind), and is updated with the results of lookup
1606 /// including zero or more declarations and possibly additional information
1607 /// used to diagnose ambiguities.
1609 /// @returns \c true if lookup succeeded and false otherwise.
1610 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
1611 DeclarationName Name = R.getLookupName();
1612 if (!Name) return false;
1614 LookupNameKind NameKind = R.getLookupKind();
1616 if (!getLangOpts().CPlusPlus) {
1617 // Unqualified name lookup in C/Objective-C is purely lexical, so
1618 // search in the declarations attached to the name.
1619 if (NameKind == Sema::LookupRedeclarationWithLinkage) {
1620 // Find the nearest non-transparent declaration scope.
1621 while (!(S->getFlags() & Scope::DeclScope) ||
1622 (S->getEntity() && S->getEntity()->isTransparentContext()))
1626 // When performing a scope lookup, we want to find local extern decls.
1627 FindLocalExternScope FindLocals(R);
1629 // Scan up the scope chain looking for a decl that matches this
1630 // identifier that is in the appropriate namespace. This search
1631 // should not take long, as shadowing of names is uncommon, and
1632 // deep shadowing is extremely uncommon.
1633 bool LeftStartingScope = false;
1635 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
1636 IEnd = IdResolver.end();
1638 if (NamedDecl *D = R.getAcceptableDecl(*I)) {
1639 if (NameKind == LookupRedeclarationWithLinkage) {
1640 // Determine whether this (or a previous) declaration is
1642 if (!LeftStartingScope && !S->isDeclScope(*I))
1643 LeftStartingScope = true;
1645 // If we found something outside of our starting scope that
1646 // does not have linkage, skip it.
1647 if (LeftStartingScope && !((*I)->hasLinkage())) {
1652 else if (NameKind == LookupObjCImplicitSelfParam &&
1653 !isa<ImplicitParamDecl>(*I))
1658 // Check whether there are any other declarations with the same name
1659 // and in the same scope.
1661 // Find the scope in which this declaration was declared (if it
1662 // actually exists in a Scope).
1663 while (S && !S->isDeclScope(D))
1666 // If the scope containing the declaration is the translation unit,
1667 // then we'll need to perform our checks based on the matching
1668 // DeclContexts rather than matching scopes.
1669 if (S && isNamespaceOrTranslationUnitScope(S))
1672 // Compute the DeclContext, if we need it.
1673 DeclContext *DC = nullptr;
1675 DC = (*I)->getDeclContext()->getRedeclContext();
1677 IdentifierResolver::iterator LastI = I;
1678 for (++LastI; LastI != IEnd; ++LastI) {
1680 // Match based on scope.
1681 if (!S->isDeclScope(*LastI))
1684 // Match based on DeclContext.
1686 = (*LastI)->getDeclContext()->getRedeclContext();
1687 if (!LastDC->Equals(DC))
1691 // If the declaration is in the right namespace and visible, add it.
1692 if (NamedDecl *LastD = R.getAcceptableDecl(*LastI))
1702 // Perform C++ unqualified name lookup.
1703 if (CppLookupName(R, S))
1707 // If we didn't find a use of this identifier, and if the identifier
1708 // corresponds to a compiler builtin, create the decl object for the builtin
1709 // now, injecting it into translation unit scope, and return it.
1710 if (AllowBuiltinCreation && LookupBuiltin(*this, R))
1713 // If we didn't find a use of this identifier, the ExternalSource
1714 // may be able to handle the situation.
1715 // Note: some lookup failures are expected!
1716 // See e.g. R.isForRedeclaration().
1717 return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
1720 /// @brief Perform qualified name lookup in the namespaces nominated by
1721 /// using directives by the given context.
1723 /// C++98 [namespace.qual]p2:
1724 /// Given X::m (where X is a user-declared namespace), or given \::m
1725 /// (where X is the global namespace), let S be the set of all
1726 /// declarations of m in X and in the transitive closure of all
1727 /// namespaces nominated by using-directives in X and its used
1728 /// namespaces, except that using-directives are ignored in any
1729 /// namespace, including X, directly containing one or more
1730 /// declarations of m. No namespace is searched more than once in
1731 /// the lookup of a name. If S is the empty set, the program is
1732 /// ill-formed. Otherwise, if S has exactly one member, or if the
1733 /// context of the reference is a using-declaration
1734 /// (namespace.udecl), S is the required set of declarations of
1735 /// m. Otherwise if the use of m is not one that allows a unique
1736 /// declaration to be chosen from S, the program is ill-formed.
1738 /// C++98 [namespace.qual]p5:
1739 /// During the lookup of a qualified namespace member name, if the
1740 /// lookup finds more than one declaration of the member, and if one
1741 /// declaration introduces a class name or enumeration name and the
1742 /// other declarations either introduce the same object, the same
1743 /// enumerator or a set of functions, the non-type name hides the
1744 /// class or enumeration name if and only if the declarations are
1745 /// from the same namespace; otherwise (the declarations are from
1746 /// different namespaces), the program is ill-formed.
1747 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
1748 DeclContext *StartDC) {
1749 assert(StartDC->isFileContext() && "start context is not a file context");
1751 DeclContext::udir_range UsingDirectives = StartDC->using_directives();
1752 if (UsingDirectives.begin() == UsingDirectives.end()) return false;
1754 // We have at least added all these contexts to the queue.
1755 llvm::SmallPtrSet<DeclContext*, 8> Visited;
1756 Visited.insert(StartDC);
1758 // We have not yet looked into these namespaces, much less added
1759 // their "using-children" to the queue.
1760 SmallVector<NamespaceDecl*, 8> Queue;
1762 // We have already looked into the initial namespace; seed the queue
1763 // with its using-children.
1764 for (auto *I : UsingDirectives) {
1765 NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace();
1766 if (Visited.insert(ND).second)
1767 Queue.push_back(ND);
1770 // The easiest way to implement the restriction in [namespace.qual]p5
1771 // is to check whether any of the individual results found a tag
1772 // and, if so, to declare an ambiguity if the final result is not
1774 bool FoundTag = false;
1775 bool FoundNonTag = false;
1777 LookupResult LocalR(LookupResult::Temporary, R);
1780 while (!Queue.empty()) {
1781 NamespaceDecl *ND = Queue.pop_back_val();
1783 // We go through some convolutions here to avoid copying results
1784 // between LookupResults.
1785 bool UseLocal = !R.empty();
1786 LookupResult &DirectR = UseLocal ? LocalR : R;
1787 bool FoundDirect = LookupDirect(S, DirectR, ND);
1790 // First do any local hiding.
1791 DirectR.resolveKind();
1793 // If the local result is a tag, remember that.
1794 if (DirectR.isSingleTagDecl())
1799 // Append the local results to the total results if necessary.
1801 R.addAllDecls(LocalR);
1806 // If we find names in this namespace, ignore its using directives.
1812 for (auto I : ND->using_directives()) {
1813 NamespaceDecl *Nom = I->getNominatedNamespace();
1814 if (Visited.insert(Nom).second)
1815 Queue.push_back(Nom);
1820 if (FoundTag && FoundNonTag)
1821 R.setAmbiguousQualifiedTagHiding();
1829 /// \brief Callback that looks for any member of a class with the given name.
1830 static bool LookupAnyMember(const CXXBaseSpecifier *Specifier,
1831 CXXBasePath &Path, DeclarationName Name) {
1832 RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
1834 Path.Decls = BaseRecord->lookup(Name);
1835 return !Path.Decls.empty();
1838 /// \brief Determine whether the given set of member declarations contains only
1839 /// static members, nested types, and enumerators.
1840 template<typename InputIterator>
1841 static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) {
1842 Decl *D = (*First)->getUnderlyingDecl();
1843 if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D))
1846 if (isa<CXXMethodDecl>(D)) {
1847 // Determine whether all of the methods are static.
1848 bool AllMethodsAreStatic = true;
1849 for(; First != Last; ++First) {
1850 D = (*First)->getUnderlyingDecl();
1852 if (!isa<CXXMethodDecl>(D)) {
1853 assert(isa<TagDecl>(D) && "Non-function must be a tag decl");
1857 if (!cast<CXXMethodDecl>(D)->isStatic()) {
1858 AllMethodsAreStatic = false;
1863 if (AllMethodsAreStatic)
1870 /// \brief Perform qualified name lookup into a given context.
1872 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
1873 /// names when the context of those names is explicit specified, e.g.,
1874 /// "std::vector" or "x->member", or as part of unqualified name lookup.
1876 /// Different lookup criteria can find different names. For example, a
1877 /// particular scope can have both a struct and a function of the same
1878 /// name, and each can be found by certain lookup criteria. For more
1879 /// information about lookup criteria, see the documentation for the
1880 /// class LookupCriteria.
1882 /// \param R captures both the lookup criteria and any lookup results found.
1884 /// \param LookupCtx The context in which qualified name lookup will
1885 /// search. If the lookup criteria permits, name lookup may also search
1886 /// in the parent contexts or (for C++ classes) base classes.
1888 /// \param InUnqualifiedLookup true if this is qualified name lookup that
1889 /// occurs as part of unqualified name lookup.
1891 /// \returns true if lookup succeeded, false if it failed.
1892 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
1893 bool InUnqualifiedLookup) {
1894 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
1896 if (!R.getLookupName())
1899 // Make sure that the declaration context is complete.
1900 assert((!isa<TagDecl>(LookupCtx) ||
1901 LookupCtx->isDependentContext() ||
1902 cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
1903 cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
1904 "Declaration context must already be complete!");
1906 struct QualifiedLookupInScope {
1908 DeclContext *Context;
1909 // Set flag in DeclContext informing debugger that we're looking for qualified name
1910 QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) {
1911 oldVal = ctx->setUseQualifiedLookup();
1913 ~QualifiedLookupInScope() {
1914 Context->setUseQualifiedLookup(oldVal);
1918 if (LookupDirect(*this, R, LookupCtx)) {
1920 if (isa<CXXRecordDecl>(LookupCtx))
1921 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
1925 // Don't descend into implied contexts for redeclarations.
1926 // C++98 [namespace.qual]p6:
1927 // In a declaration for a namespace member in which the
1928 // declarator-id is a qualified-id, given that the qualified-id
1929 // for the namespace member has the form
1930 // nested-name-specifier unqualified-id
1931 // the unqualified-id shall name a member of the namespace
1932 // designated by the nested-name-specifier.
1933 // See also [class.mfct]p5 and [class.static.data]p2.
1934 if (R.isForRedeclaration())
1937 // If this is a namespace, look it up in the implied namespaces.
1938 if (LookupCtx->isFileContext())
1939 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
1941 // If this isn't a C++ class, we aren't allowed to look into base
1942 // classes, we're done.
1943 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
1944 if (!LookupRec || !LookupRec->getDefinition())
1947 // If we're performing qualified name lookup into a dependent class,
1948 // then we are actually looking into a current instantiation. If we have any
1949 // dependent base classes, then we either have to delay lookup until
1950 // template instantiation time (at which point all bases will be available)
1951 // or we have to fail.
1952 if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
1953 LookupRec->hasAnyDependentBases()) {
1954 R.setNotFoundInCurrentInstantiation();
1958 // Perform lookup into our base classes.
1960 Paths.setOrigin(LookupRec);
1962 // Look for this member in our base classes
1963 bool (*BaseCallback)(const CXXBaseSpecifier *Specifier, CXXBasePath &Path,
1964 DeclarationName Name) = nullptr;
1965 switch (R.getLookupKind()) {
1966 case LookupObjCImplicitSelfParam:
1967 case LookupOrdinaryName:
1968 case LookupMemberName:
1969 case LookupRedeclarationWithLinkage:
1970 case LookupLocalFriendName:
1971 BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
1975 BaseCallback = &CXXRecordDecl::FindTagMember;
1979 BaseCallback = &LookupAnyMember;
1982 case LookupUsingDeclName:
1983 // This lookup is for redeclarations only.
1985 case LookupOperatorName:
1986 case LookupNamespaceName:
1987 case LookupObjCProtocolName:
1989 // These lookups will never find a member in a C++ class (or base class).
1992 case LookupNestedNameSpecifierName:
1993 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember;
1997 DeclarationName Name = R.getLookupName();
1998 if (!LookupRec->lookupInBases(
1999 [=](const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
2000 return BaseCallback(Specifier, Path, Name);
2005 R.setNamingClass(LookupRec);
2007 // C++ [class.member.lookup]p2:
2008 // [...] If the resulting set of declarations are not all from
2009 // sub-objects of the same type, or the set has a nonstatic member
2010 // and includes members from distinct sub-objects, there is an
2011 // ambiguity and the program is ill-formed. Otherwise that set is
2012 // the result of the lookup.
2013 QualType SubobjectType;
2014 int SubobjectNumber = 0;
2015 AccessSpecifier SubobjectAccess = AS_none;
2017 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
2018 Path != PathEnd; ++Path) {
2019 const CXXBasePathElement &PathElement = Path->back();
2021 // Pick the best (i.e. most permissive i.e. numerically lowest) access
2022 // across all paths.
2023 SubobjectAccess = std::min(SubobjectAccess, Path->Access);
2025 // Determine whether we're looking at a distinct sub-object or not.
2026 if (SubobjectType.isNull()) {
2027 // This is the first subobject we've looked at. Record its type.
2028 SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
2029 SubobjectNumber = PathElement.SubobjectNumber;
2034 != Context.getCanonicalType(PathElement.Base->getType())) {
2035 // We found members of the given name in two subobjects of
2036 // different types. If the declaration sets aren't the same, this
2037 // lookup is ambiguous.
2038 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) {
2039 CXXBasePaths::paths_iterator FirstPath = Paths.begin();
2040 DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin();
2041 DeclContext::lookup_iterator CurrentD = Path->Decls.begin();
2043 while (FirstD != FirstPath->Decls.end() &&
2044 CurrentD != Path->Decls.end()) {
2045 if ((*FirstD)->getUnderlyingDecl()->getCanonicalDecl() !=
2046 (*CurrentD)->getUnderlyingDecl()->getCanonicalDecl())
2053 if (FirstD == FirstPath->Decls.end() &&
2054 CurrentD == Path->Decls.end())
2058 R.setAmbiguousBaseSubobjectTypes(Paths);
2062 if (SubobjectNumber != PathElement.SubobjectNumber) {
2063 // We have a different subobject of the same type.
2065 // C++ [class.member.lookup]p5:
2066 // A static member, a nested type or an enumerator defined in
2067 // a base class T can unambiguously be found even if an object
2068 // has more than one base class subobject of type T.
2069 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end()))
2072 // We have found a nonstatic member name in multiple, distinct
2073 // subobjects. Name lookup is ambiguous.
2074 R.setAmbiguousBaseSubobjects(Paths);
2079 // Lookup in a base class succeeded; return these results.
2081 for (auto *D : Paths.front().Decls) {
2082 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
2090 /// \brief Performs qualified name lookup or special type of lookup for
2091 /// "__super::" scope specifier.
2093 /// This routine is a convenience overload meant to be called from contexts
2094 /// that need to perform a qualified name lookup with an optional C++ scope
2095 /// specifier that might require special kind of lookup.
2097 /// \param R captures both the lookup criteria and any lookup results found.
2099 /// \param LookupCtx The context in which qualified name lookup will
2102 /// \param SS An optional C++ scope-specifier.
2104 /// \returns true if lookup succeeded, false if it failed.
2105 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2107 auto *NNS = SS.getScopeRep();
2108 if (NNS && NNS->getKind() == NestedNameSpecifier::Super)
2109 return LookupInSuper(R, NNS->getAsRecordDecl());
2112 return LookupQualifiedName(R, LookupCtx);
2115 /// @brief Performs name lookup for a name that was parsed in the
2116 /// source code, and may contain a C++ scope specifier.
2118 /// This routine is a convenience routine meant to be called from
2119 /// contexts that receive a name and an optional C++ scope specifier
2120 /// (e.g., "N::M::x"). It will then perform either qualified or
2121 /// unqualified name lookup (with LookupQualifiedName or LookupName,
2122 /// respectively) on the given name and return those results. It will
2123 /// perform a special type of lookup for "__super::" scope specifier.
2125 /// @param S The scope from which unqualified name lookup will
2128 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
2130 /// @param EnteringContext Indicates whether we are going to enter the
2131 /// context of the scope-specifier SS (if present).
2133 /// @returns True if any decls were found (but possibly ambiguous)
2134 bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
2135 bool AllowBuiltinCreation, bool EnteringContext) {
2136 if (SS && SS->isInvalid()) {
2137 // When the scope specifier is invalid, don't even look for
2142 if (SS && SS->isSet()) {
2143 NestedNameSpecifier *NNS = SS->getScopeRep();
2144 if (NNS->getKind() == NestedNameSpecifier::Super)
2145 return LookupInSuper(R, NNS->getAsRecordDecl());
2147 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
2148 // We have resolved the scope specifier to a particular declaration
2149 // contex, and will perform name lookup in that context.
2150 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
2153 R.setContextRange(SS->getRange());
2154 return LookupQualifiedName(R, DC);
2157 // We could not resolve the scope specified to a specific declaration
2158 // context, which means that SS refers to an unknown specialization.
2159 // Name lookup can't find anything in this case.
2160 R.setNotFoundInCurrentInstantiation();
2161 R.setContextRange(SS->getRange());
2165 // Perform unqualified name lookup starting in the given scope.
2166 return LookupName(R, S, AllowBuiltinCreation);
2169 /// \brief Perform qualified name lookup into all base classes of the given
2172 /// \param R captures both the lookup criteria and any lookup results found.
2174 /// \param Class The context in which qualified name lookup will
2175 /// search. Name lookup will search in all base classes merging the results.
2177 /// @returns True if any decls were found (but possibly ambiguous)
2178 bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) {
2179 // The access-control rules we use here are essentially the rules for
2180 // doing a lookup in Class that just magically skipped the direct
2181 // members of Class itself. That is, the naming class is Class, and the
2182 // access includes the access of the base.
2183 for (const auto &BaseSpec : Class->bases()) {
2184 CXXRecordDecl *RD = cast<CXXRecordDecl>(
2185 BaseSpec.getType()->castAs<RecordType>()->getDecl());
2186 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
2187 Result.setBaseObjectType(Context.getRecordType(Class));
2188 LookupQualifiedName(Result, RD);
2190 // Copy the lookup results into the target, merging the base's access into
2192 for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
2193 R.addDecl(I.getDecl(),
2194 CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(),
2198 Result.suppressDiagnostics();
2202 R.setNamingClass(Class);
2207 /// \brief Produce a diagnostic describing the ambiguity that resulted
2208 /// from name lookup.
2210 /// \param Result The result of the ambiguous lookup to be diagnosed.
2211 void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
2212 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
2214 DeclarationName Name = Result.getLookupName();
2215 SourceLocation NameLoc = Result.getNameLoc();
2216 SourceRange LookupRange = Result.getContextRange();
2218 switch (Result.getAmbiguityKind()) {
2219 case LookupResult::AmbiguousBaseSubobjects: {
2220 CXXBasePaths *Paths = Result.getBasePaths();
2221 QualType SubobjectType = Paths->front().back().Base->getType();
2222 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
2223 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
2226 DeclContext::lookup_iterator Found = Paths->front().Decls.begin();
2227 while (isa<CXXMethodDecl>(*Found) &&
2228 cast<CXXMethodDecl>(*Found)->isStatic())
2231 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
2235 case LookupResult::AmbiguousBaseSubobjectTypes: {
2236 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
2237 << Name << LookupRange;
2239 CXXBasePaths *Paths = Result.getBasePaths();
2240 std::set<Decl *> DeclsPrinted;
2241 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
2242 PathEnd = Paths->end();
2243 Path != PathEnd; ++Path) {
2244 Decl *D = Path->Decls.front();
2245 if (DeclsPrinted.insert(D).second)
2246 Diag(D->getLocation(), diag::note_ambiguous_member_found);
2251 case LookupResult::AmbiguousTagHiding: {
2252 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
2254 llvm::SmallPtrSet<NamedDecl*, 8> TagDecls;
2256 for (auto *D : Result)
2257 if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
2258 TagDecls.insert(TD);
2259 Diag(TD->getLocation(), diag::note_hidden_tag);
2262 for (auto *D : Result)
2263 if (!isa<TagDecl>(D))
2264 Diag(D->getLocation(), diag::note_hiding_object);
2266 // For recovery purposes, go ahead and implement the hiding.
2267 LookupResult::Filter F = Result.makeFilter();
2268 while (F.hasNext()) {
2269 if (TagDecls.count(F.next()))
2276 case LookupResult::AmbiguousReference: {
2277 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
2279 for (auto *D : Result)
2280 Diag(D->getLocation(), diag::note_ambiguous_candidate) << D;
2287 struct AssociatedLookup {
2288 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
2289 Sema::AssociatedNamespaceSet &Namespaces,
2290 Sema::AssociatedClassSet &Classes)
2291 : S(S), Namespaces(Namespaces), Classes(Classes),
2292 InstantiationLoc(InstantiationLoc) {
2296 Sema::AssociatedNamespaceSet &Namespaces;
2297 Sema::AssociatedClassSet &Classes;
2298 SourceLocation InstantiationLoc;
2300 } // end anonymous namespace
2303 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
2305 static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces,
2307 // Add the associated namespace for this class.
2309 // We don't use DeclContext::getEnclosingNamespaceContext() as this may
2310 // be a locally scoped record.
2312 // We skip out of inline namespaces. The innermost non-inline namespace
2313 // contains all names of all its nested inline namespaces anyway, so we can
2314 // replace the entire inline namespace tree with its root.
2315 while (Ctx->isRecord() || Ctx->isTransparentContext() ||
2316 Ctx->isInlineNamespace())
2317 Ctx = Ctx->getParent();
2319 if (Ctx->isFileContext())
2320 Namespaces.insert(Ctx->getPrimaryContext());
2323 // \brief Add the associated classes and namespaces for argument-dependent
2324 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2).
2326 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2327 const TemplateArgument &Arg) {
2328 // C++ [basic.lookup.koenig]p2, last bullet:
2330 switch (Arg.getKind()) {
2331 case TemplateArgument::Null:
2334 case TemplateArgument::Type:
2335 // [...] the namespaces and classes associated with the types of the
2336 // template arguments provided for template type parameters (excluding
2337 // template template parameters)
2338 addAssociatedClassesAndNamespaces(Result, Arg.getAsType());
2341 case TemplateArgument::Template:
2342 case TemplateArgument::TemplateExpansion: {
2343 // [...] the namespaces in which any template template arguments are
2344 // defined; and the classes in which any member templates used as
2345 // template template arguments are defined.
2346 TemplateName Template = Arg.getAsTemplateOrTemplatePattern();
2347 if (ClassTemplateDecl *ClassTemplate
2348 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
2349 DeclContext *Ctx = ClassTemplate->getDeclContext();
2350 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2351 Result.Classes.insert(EnclosingClass);
2352 // Add the associated namespace for this class.
2353 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2358 case TemplateArgument::Declaration:
2359 case TemplateArgument::Integral:
2360 case TemplateArgument::Expression:
2361 case TemplateArgument::NullPtr:
2362 // [Note: non-type template arguments do not contribute to the set of
2363 // associated namespaces. ]
2366 case TemplateArgument::Pack:
2367 for (const auto &P : Arg.pack_elements())
2368 addAssociatedClassesAndNamespaces(Result, P);
2373 // \brief Add the associated classes and namespaces for
2374 // argument-dependent lookup with an argument of class type
2375 // (C++ [basic.lookup.koenig]p2).
2377 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2378 CXXRecordDecl *Class) {
2380 // Just silently ignore anything whose name is __va_list_tag.
2381 if (Class->getDeclName() == Result.S.VAListTagName)
2384 // C++ [basic.lookup.koenig]p2:
2386 // -- If T is a class type (including unions), its associated
2387 // classes are: the class itself; the class of which it is a
2388 // member, if any; and its direct and indirect base
2389 // classes. Its associated namespaces are the namespaces in
2390 // which its associated classes are defined.
2392 // Add the class of which it is a member, if any.
2393 DeclContext *Ctx = Class->getDeclContext();
2394 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2395 Result.Classes.insert(EnclosingClass);
2396 // Add the associated namespace for this class.
2397 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2399 // Add the class itself. If we've already seen this class, we don't
2400 // need to visit base classes.
2402 // FIXME: That's not correct, we may have added this class only because it
2403 // was the enclosing class of another class, and in that case we won't have
2404 // added its base classes yet.
2405 if (!Result.Classes.insert(Class).second)
2408 // -- If T is a template-id, its associated namespaces and classes are
2409 // the namespace in which the template is defined; for member
2410 // templates, the member template's class; the namespaces and classes
2411 // associated with the types of the template arguments provided for
2412 // template type parameters (excluding template template parameters); the
2413 // namespaces in which any template template arguments are defined; and
2414 // the classes in which any member templates used as template template
2415 // arguments are defined. [Note: non-type template arguments do not
2416 // contribute to the set of associated namespaces. ]
2417 if (ClassTemplateSpecializationDecl *Spec
2418 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
2419 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
2420 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2421 Result.Classes.insert(EnclosingClass);
2422 // Add the associated namespace for this class.
2423 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2425 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
2426 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2427 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]);
2430 // Only recurse into base classes for complete types.
2431 if (!Result.S.isCompleteType(Result.InstantiationLoc,
2432 Result.S.Context.getRecordType(Class)))
2435 // Add direct and indirect base classes along with their associated
2437 SmallVector<CXXRecordDecl *, 32> Bases;
2438 Bases.push_back(Class);
2439 while (!Bases.empty()) {
2440 // Pop this class off the stack.
2441 Class = Bases.pop_back_val();
2443 // Visit the base classes.
2444 for (const auto &Base : Class->bases()) {
2445 const RecordType *BaseType = Base.getType()->getAs<RecordType>();
2446 // In dependent contexts, we do ADL twice, and the first time around,
2447 // the base type might be a dependent TemplateSpecializationType, or a
2448 // TemplateTypeParmType. If that happens, simply ignore it.
2449 // FIXME: If we want to support export, we probably need to add the
2450 // namespace of the template in a TemplateSpecializationType, or even
2451 // the classes and namespaces of known non-dependent arguments.
2454 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
2455 if (Result.Classes.insert(BaseDecl).second) {
2456 // Find the associated namespace for this base class.
2457 DeclContext *BaseCtx = BaseDecl->getDeclContext();
2458 CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
2460 // Make sure we visit the bases of this base class.
2461 if (BaseDecl->bases_begin() != BaseDecl->bases_end())
2462 Bases.push_back(BaseDecl);
2468 // \brief Add the associated classes and namespaces for
2469 // argument-dependent lookup with an argument of type T
2470 // (C++ [basic.lookup.koenig]p2).
2472 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
2473 // C++ [basic.lookup.koenig]p2:
2475 // For each argument type T in the function call, there is a set
2476 // of zero or more associated namespaces and a set of zero or more
2477 // associated classes to be considered. The sets of namespaces and
2478 // classes is determined entirely by the types of the function
2479 // arguments (and the namespace of any template template
2480 // argument). Typedef names and using-declarations used to specify
2481 // the types do not contribute to this set. The sets of namespaces
2482 // and classes are determined in the following way:
2484 SmallVector<const Type *, 16> Queue;
2485 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
2488 switch (T->getTypeClass()) {
2490 #define TYPE(Class, Base)
2491 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
2492 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
2493 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
2494 #define ABSTRACT_TYPE(Class, Base)
2495 #include "clang/AST/TypeNodes.def"
2496 // T is canonical. We can also ignore dependent types because
2497 // we don't need to do ADL at the definition point, but if we
2498 // wanted to implement template export (or if we find some other
2499 // use for associated classes and namespaces...) this would be
2503 // -- If T is a pointer to U or an array of U, its associated
2504 // namespaces and classes are those associated with U.
2506 T = cast<PointerType>(T)->getPointeeType().getTypePtr();
2508 case Type::ConstantArray:
2509 case Type::IncompleteArray:
2510 case Type::VariableArray:
2511 T = cast<ArrayType>(T)->getElementType().getTypePtr();
2514 // -- If T is a fundamental type, its associated sets of
2515 // namespaces and classes are both empty.
2519 // -- If T is a class type (including unions), its associated
2520 // classes are: the class itself; the class of which it is a
2521 // member, if any; and its direct and indirect base
2522 // classes. Its associated namespaces are the namespaces in
2523 // which its associated classes are defined.
2524 case Type::Record: {
2525 CXXRecordDecl *Class =
2526 cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl());
2527 addAssociatedClassesAndNamespaces(Result, Class);
2531 // -- If T is an enumeration type, its associated namespace is
2532 // the namespace in which it is defined. If it is class
2533 // member, its associated class is the member's class; else
2534 // it has no associated class.
2536 EnumDecl *Enum = cast<EnumType>(T)->getDecl();
2538 DeclContext *Ctx = Enum->getDeclContext();
2539 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2540 Result.Classes.insert(EnclosingClass);
2542 // Add the associated namespace for this class.
2543 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2548 // -- If T is a function type, its associated namespaces and
2549 // classes are those associated with the function parameter
2550 // types and those associated with the return type.
2551 case Type::FunctionProto: {
2552 const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
2553 for (const auto &Arg : Proto->param_types())
2554 Queue.push_back(Arg.getTypePtr());
2557 case Type::FunctionNoProto: {
2558 const FunctionType *FnType = cast<FunctionType>(T);
2559 T = FnType->getReturnType().getTypePtr();
2563 // -- If T is a pointer to a member function of a class X, its
2564 // associated namespaces and classes are those associated
2565 // with the function parameter types and return type,
2566 // together with those associated with X.
2568 // -- If T is a pointer to a data member of class X, its
2569 // associated namespaces and classes are those associated
2570 // with the member type together with those associated with
2572 case Type::MemberPointer: {
2573 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T);
2575 // Queue up the class type into which this points.
2576 Queue.push_back(MemberPtr->getClass());
2578 // And directly continue with the pointee type.
2579 T = MemberPtr->getPointeeType().getTypePtr();
2583 // As an extension, treat this like a normal pointer.
2584 case Type::BlockPointer:
2585 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr();
2588 // References aren't covered by the standard, but that's such an
2589 // obvious defect that we cover them anyway.
2590 case Type::LValueReference:
2591 case Type::RValueReference:
2592 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr();
2595 // These are fundamental types.
2597 case Type::ExtVector:
2601 // Non-deduced auto types only get here for error cases.
2605 // If T is an Objective-C object or interface type, or a pointer to an
2606 // object or interface type, the associated namespace is the global
2608 case Type::ObjCObject:
2609 case Type::ObjCInterface:
2610 case Type::ObjCObjectPointer:
2611 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
2614 // Atomic types are just wrappers; use the associations of the
2617 T = cast<AtomicType>(T)->getValueType().getTypePtr();
2623 T = Queue.pop_back_val();
2627 /// \brief Find the associated classes and namespaces for
2628 /// argument-dependent lookup for a call with the given set of
2631 /// This routine computes the sets of associated classes and associated
2632 /// namespaces searched by argument-dependent lookup
2633 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
2634 void Sema::FindAssociatedClassesAndNamespaces(
2635 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
2636 AssociatedNamespaceSet &AssociatedNamespaces,
2637 AssociatedClassSet &AssociatedClasses) {
2638 AssociatedNamespaces.clear();
2639 AssociatedClasses.clear();
2641 AssociatedLookup Result(*this, InstantiationLoc,
2642 AssociatedNamespaces, AssociatedClasses);
2644 // C++ [basic.lookup.koenig]p2:
2645 // For each argument type T in the function call, there is a set
2646 // of zero or more associated namespaces and a set of zero or more
2647 // associated classes to be considered. The sets of namespaces and
2648 // classes is determined entirely by the types of the function
2649 // arguments (and the namespace of any template template
2651 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
2652 Expr *Arg = Args[ArgIdx];
2654 if (Arg->getType() != Context.OverloadTy) {
2655 addAssociatedClassesAndNamespaces(Result, Arg->getType());
2659 // [...] In addition, if the argument is the name or address of a
2660 // set of overloaded functions and/or function templates, its
2661 // associated classes and namespaces are the union of those
2662 // associated with each of the members of the set: the namespace
2663 // in which the function or function template is defined and the
2664 // classes and namespaces associated with its (non-dependent)
2665 // parameter types and return type.
2666 Arg = Arg->IgnoreParens();
2667 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg))
2668 if (unaryOp->getOpcode() == UO_AddrOf)
2669 Arg = unaryOp->getSubExpr();
2671 UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg);
2674 for (const auto *D : ULE->decls()) {
2675 // Look through any using declarations to find the underlying function.
2676 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
2678 // Add the classes and namespaces associated with the parameter
2679 // types and return type of this function.
2680 addAssociatedClassesAndNamespaces(Result, FDecl->getType());
2685 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
2687 LookupNameKind NameKind,
2688 RedeclarationKind Redecl) {
2689 LookupResult R(*this, Name, Loc, NameKind, Redecl);
2691 return R.getAsSingle<NamedDecl>();
2694 /// \brief Find the protocol with the given name, if any.
2695 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II,
2696 SourceLocation IdLoc,
2697 RedeclarationKind Redecl) {
2698 Decl *D = LookupSingleName(TUScope, II, IdLoc,
2699 LookupObjCProtocolName, Redecl);
2700 return cast_or_null<ObjCProtocolDecl>(D);
2703 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
2704 QualType T1, QualType T2,
2705 UnresolvedSetImpl &Functions) {
2706 // C++ [over.match.oper]p3:
2707 // -- The set of non-member candidates is the result of the
2708 // unqualified lookup of operator@ in the context of the
2709 // expression according to the usual rules for name lookup in
2710 // unqualified function calls (3.4.2) except that all member
2711 // functions are ignored.
2712 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
2713 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
2714 LookupName(Operators, S);
2716 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
2717 Functions.append(Operators.begin(), Operators.end());
2720 Sema::SpecialMemberOverloadResult *Sema::LookupSpecialMember(CXXRecordDecl *RD,
2721 CXXSpecialMember SM,
2726 bool VolatileThis) {
2727 assert(CanDeclareSpecialMemberFunction(RD) &&
2728 "doing special member lookup into record that isn't fully complete");
2729 RD = RD->getDefinition();
2730 if (RValueThis || ConstThis || VolatileThis)
2731 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) &&
2732 "constructors and destructors always have unqualified lvalue this");
2733 if (ConstArg || VolatileArg)
2734 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) &&
2735 "parameter-less special members can't have qualified arguments");
2737 llvm::FoldingSetNodeID ID;
2740 ID.AddInteger(ConstArg);
2741 ID.AddInteger(VolatileArg);
2742 ID.AddInteger(RValueThis);
2743 ID.AddInteger(ConstThis);
2744 ID.AddInteger(VolatileThis);
2747 SpecialMemberOverloadResult *Result =
2748 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
2750 // This was already cached
2754 Result = BumpAlloc.Allocate<SpecialMemberOverloadResult>();
2755 Result = new (Result) SpecialMemberOverloadResult(ID);
2756 SpecialMemberCache.InsertNode(Result, InsertPoint);
2758 if (SM == CXXDestructor) {
2759 if (RD->needsImplicitDestructor())
2760 DeclareImplicitDestructor(RD);
2761 CXXDestructorDecl *DD = RD->getDestructor();
2762 assert(DD && "record without a destructor");
2763 Result->setMethod(DD);
2764 Result->setKind(DD->isDeleted() ?
2765 SpecialMemberOverloadResult::NoMemberOrDeleted :
2766 SpecialMemberOverloadResult::Success);
2770 // Prepare for overload resolution. Here we construct a synthetic argument
2771 // if necessary and make sure that implicit functions are declared.
2772 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD));
2773 DeclarationName Name;
2774 Expr *Arg = nullptr;
2777 QualType ArgType = CanTy;
2778 ExprValueKind VK = VK_LValue;
2780 if (SM == CXXDefaultConstructor) {
2781 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2783 if (RD->needsImplicitDefaultConstructor())
2784 DeclareImplicitDefaultConstructor(RD);
2786 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) {
2787 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2788 if (RD->needsImplicitCopyConstructor())
2789 DeclareImplicitCopyConstructor(RD);
2790 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor())
2791 DeclareImplicitMoveConstructor(RD);
2793 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
2794 if (RD->needsImplicitCopyAssignment())
2795 DeclareImplicitCopyAssignment(RD);
2796 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment())
2797 DeclareImplicitMoveAssignment(RD);
2803 ArgType.addVolatile();
2805 // This isn't /really/ specified by the standard, but it's implied
2806 // we should be working from an RValue in the case of move to ensure
2807 // that we prefer to bind to rvalue references, and an LValue in the
2808 // case of copy to ensure we don't bind to rvalue references.
2809 // Possibly an XValue is actually correct in the case of move, but
2810 // there is no semantic difference for class types in this restricted
2812 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment)
2818 OpaqueValueExpr FakeArg(SourceLocation(), ArgType, VK);
2820 if (SM != CXXDefaultConstructor) {
2825 // Create the object argument
2826 QualType ThisTy = CanTy;
2830 ThisTy.addVolatile();
2831 Expr::Classification Classification =
2832 OpaqueValueExpr(SourceLocation(), ThisTy,
2833 RValueThis ? VK_RValue : VK_LValue).Classify(Context);
2835 // Now we perform lookup on the name we computed earlier and do overload
2836 // resolution. Lookup is only performed directly into the class since there
2837 // will always be a (possibly implicit) declaration to shadow any others.
2838 OverloadCandidateSet OCS(RD->getLocation(), OverloadCandidateSet::CSK_Normal);
2839 DeclContext::lookup_result R = RD->lookup(Name);
2842 // We might have no default constructor because we have a lambda's closure
2843 // type, rather than because there's some other declared constructor.
2844 // Every class has a copy/move constructor, copy/move assignment, and
2846 assert(SM == CXXDefaultConstructor &&
2847 "lookup for a constructor or assignment operator was empty");
2848 Result->setMethod(nullptr);
2849 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2853 // Copy the candidates as our processing of them may load new declarations
2854 // from an external source and invalidate lookup_result.
2855 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
2857 for (auto *Cand : Candidates) {
2858 if (Cand->isInvalidDecl())
2861 if (UsingShadowDecl *U = dyn_cast<UsingShadowDecl>(Cand)) {
2862 // FIXME: [namespace.udecl]p15 says that we should only consider a
2863 // using declaration here if it does not match a declaration in the
2864 // derived class. We do not implement this correctly in other cases
2866 Cand = U->getTargetDecl();
2868 if (Cand->isInvalidDecl())
2872 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand)) {
2873 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2874 AddMethodCandidate(M, DeclAccessPair::make(M, AS_public), RD, ThisTy,
2875 Classification, llvm::makeArrayRef(&Arg, NumArgs),
2878 AddOverloadCandidate(M, DeclAccessPair::make(M, AS_public),
2879 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2880 } else if (FunctionTemplateDecl *Tmpl =
2881 dyn_cast<FunctionTemplateDecl>(Cand)) {
2882 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2883 AddMethodTemplateCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public),
2884 RD, nullptr, ThisTy, Classification,
2885 llvm::makeArrayRef(&Arg, NumArgs),
2888 AddTemplateOverloadCandidate(Tmpl, DeclAccessPair::make(Tmpl, AS_public),
2889 nullptr, llvm::makeArrayRef(&Arg, NumArgs),
2892 assert(isa<UsingDecl>(Cand) && "illegal Kind of operator = Decl");
2896 OverloadCandidateSet::iterator Best;
2897 switch (OCS.BestViableFunction(*this, SourceLocation(), Best)) {
2899 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
2900 Result->setKind(SpecialMemberOverloadResult::Success);
2904 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
2905 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2909 Result->setMethod(nullptr);
2910 Result->setKind(SpecialMemberOverloadResult::Ambiguous);
2913 case OR_No_Viable_Function:
2914 Result->setMethod(nullptr);
2915 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2922 /// \brief Look up the default constructor for the given class.
2923 CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) {
2924 SpecialMemberOverloadResult *Result =
2925 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false,
2928 return cast_or_null<CXXConstructorDecl>(Result->getMethod());
2931 /// \brief Look up the copying constructor for the given class.
2932 CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class,
2934 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
2935 "non-const, non-volatile qualifiers for copy ctor arg");
2936 SpecialMemberOverloadResult *Result =
2937 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const,
2938 Quals & Qualifiers::Volatile, false, false, false);
2940 return cast_or_null<CXXConstructorDecl>(Result->getMethod());
2943 /// \brief Look up the moving constructor for the given class.
2944 CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class,
2946 SpecialMemberOverloadResult *Result =
2947 LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const,
2948 Quals & Qualifiers::Volatile, false, false, false);
2950 return cast_or_null<CXXConstructorDecl>(Result->getMethod());
2953 /// \brief Look up the constructors for the given class.
2954 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) {
2955 // If the implicit constructors have not yet been declared, do so now.
2956 if (CanDeclareSpecialMemberFunction(Class)) {
2957 if (Class->needsImplicitDefaultConstructor())
2958 DeclareImplicitDefaultConstructor(Class);
2959 if (Class->needsImplicitCopyConstructor())
2960 DeclareImplicitCopyConstructor(Class);
2961 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
2962 DeclareImplicitMoveConstructor(Class);
2965 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class));
2966 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T);
2967 return Class->lookup(Name);
2970 /// \brief Look up the copying assignment operator for the given class.
2971 CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class,
2972 unsigned Quals, bool RValueThis,
2973 unsigned ThisQuals) {
2974 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
2975 "non-const, non-volatile qualifiers for copy assignment arg");
2976 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
2977 "non-const, non-volatile qualifiers for copy assignment this");
2978 SpecialMemberOverloadResult *Result =
2979 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const,
2980 Quals & Qualifiers::Volatile, RValueThis,
2981 ThisQuals & Qualifiers::Const,
2982 ThisQuals & Qualifiers::Volatile);
2984 return Result->getMethod();
2987 /// \brief Look up the moving assignment operator for the given class.
2988 CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class,
2991 unsigned ThisQuals) {
2992 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
2993 "non-const, non-volatile qualifiers for copy assignment this");
2994 SpecialMemberOverloadResult *Result =
2995 LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const,
2996 Quals & Qualifiers::Volatile, RValueThis,
2997 ThisQuals & Qualifiers::Const,
2998 ThisQuals & Qualifiers::Volatile);
3000 return Result->getMethod();
3003 /// \brief Look for the destructor of the given class.
3005 /// During semantic analysis, this routine should be used in lieu of
3006 /// CXXRecordDecl::getDestructor().
3008 /// \returns The destructor for this class.
3009 CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) {
3010 return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor,
3011 false, false, false,
3012 false, false)->getMethod());
3015 /// LookupLiteralOperator - Determine which literal operator should be used for
3016 /// a user-defined literal, per C++11 [lex.ext].
3018 /// Normal overload resolution is not used to select which literal operator to
3019 /// call for a user-defined literal. Look up the provided literal operator name,
3020 /// and filter the results to the appropriate set for the given argument types.
3021 Sema::LiteralOperatorLookupResult
3022 Sema::LookupLiteralOperator(Scope *S, LookupResult &R,
3023 ArrayRef<QualType> ArgTys,
3024 bool AllowRaw, bool AllowTemplate,
3025 bool AllowStringTemplate) {
3027 assert(R.getResultKind() != LookupResult::Ambiguous &&
3028 "literal operator lookup can't be ambiguous");
3030 // Filter the lookup results appropriately.
3031 LookupResult::Filter F = R.makeFilter();
3033 bool FoundRaw = false;
3034 bool FoundTemplate = false;
3035 bool FoundStringTemplate = false;
3036 bool FoundExactMatch = false;
3038 while (F.hasNext()) {
3040 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
3041 D = USD->getTargetDecl();
3043 // If the declaration we found is invalid, skip it.
3044 if (D->isInvalidDecl()) {
3050 bool IsTemplate = false;
3051 bool IsStringTemplate = false;
3052 bool IsExactMatch = false;
3054 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
3055 if (FD->getNumParams() == 1 &&
3056 FD->getParamDecl(0)->getType()->getAs<PointerType>())
3058 else if (FD->getNumParams() == ArgTys.size()) {
3059 IsExactMatch = true;
3060 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
3061 QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
3062 if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
3063 IsExactMatch = false;
3069 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) {
3070 TemplateParameterList *Params = FD->getTemplateParameters();
3071 if (Params->size() == 1)
3074 IsStringTemplate = true;
3078 FoundExactMatch = true;
3080 AllowTemplate = false;
3081 AllowStringTemplate = false;
3082 if (FoundRaw || FoundTemplate || FoundStringTemplate) {
3083 // Go through again and remove the raw and template decls we've
3086 FoundRaw = FoundTemplate = FoundStringTemplate = false;
3088 } else if (AllowRaw && IsRaw) {
3090 } else if (AllowTemplate && IsTemplate) {
3091 FoundTemplate = true;
3092 } else if (AllowStringTemplate && IsStringTemplate) {
3093 FoundStringTemplate = true;
3101 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
3102 // parameter type, that is used in preference to a raw literal operator
3103 // or literal operator template.
3104 if (FoundExactMatch)
3107 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
3108 // operator template, but not both.
3109 if (FoundRaw && FoundTemplate) {
3110 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
3111 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
3112 NoteOverloadCandidate((*I)->getUnderlyingDecl()->getAsFunction());
3120 return LOLR_Template;
3122 if (FoundStringTemplate)
3123 return LOLR_StringTemplate;
3125 // Didn't find anything we could use.
3126 Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
3127 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
3128 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
3129 << (AllowTemplate || AllowStringTemplate);
3133 void ADLResult::insert(NamedDecl *New) {
3134 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
3136 // If we haven't yet seen a decl for this key, or the last decl
3137 // was exactly this one, we're done.
3138 if (Old == nullptr || Old == New) {
3143 // Otherwise, decide which is a more recent redeclaration.
3144 FunctionDecl *OldFD = Old->getAsFunction();
3145 FunctionDecl *NewFD = New->getAsFunction();
3147 FunctionDecl *Cursor = NewFD;
3149 Cursor = Cursor->getPreviousDecl();
3151 // If we got to the end without finding OldFD, OldFD is the newer
3152 // declaration; leave things as they are.
3153 if (!Cursor) return;
3155 // If we do find OldFD, then NewFD is newer.
3156 if (Cursor == OldFD) break;
3158 // Otherwise, keep looking.
3164 void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
3165 ArrayRef<Expr *> Args, ADLResult &Result) {
3166 // Find all of the associated namespaces and classes based on the
3167 // arguments we have.
3168 AssociatedNamespaceSet AssociatedNamespaces;
3169 AssociatedClassSet AssociatedClasses;
3170 FindAssociatedClassesAndNamespaces(Loc, Args,
3171 AssociatedNamespaces,
3174 // C++ [basic.lookup.argdep]p3:
3175 // Let X be the lookup set produced by unqualified lookup (3.4.1)
3176 // and let Y be the lookup set produced by argument dependent
3177 // lookup (defined as follows). If X contains [...] then Y is
3178 // empty. Otherwise Y is the set of declarations found in the
3179 // namespaces associated with the argument types as described
3180 // below. The set of declarations found by the lookup of the name
3181 // is the union of X and Y.
3183 // Here, we compute Y and add its members to the overloaded
3185 for (auto *NS : AssociatedNamespaces) {
3186 // When considering an associated namespace, the lookup is the
3187 // same as the lookup performed when the associated namespace is
3188 // used as a qualifier (3.4.3.2) except that:
3190 // -- Any using-directives in the associated namespace are
3193 // -- Any namespace-scope friend functions declared in
3194 // associated classes are visible within their respective
3195 // namespaces even if they are not visible during an ordinary
3197 DeclContext::lookup_result R = NS->lookup(Name);
3199 // If the only declaration here is an ordinary friend, consider
3200 // it only if it was declared in an associated classes.
3201 if ((D->getIdentifierNamespace() & Decl::IDNS_Ordinary) == 0) {
3202 // If it's neither ordinarily visible nor a friend, we can't find it.
3203 if ((D->getIdentifierNamespace() & Decl::IDNS_OrdinaryFriend) == 0)
3206 bool DeclaredInAssociatedClass = false;
3207 for (Decl *DI = D; DI; DI = DI->getPreviousDecl()) {
3208 DeclContext *LexDC = DI->getLexicalDeclContext();
3209 if (isa<CXXRecordDecl>(LexDC) &&
3210 AssociatedClasses.count(cast<CXXRecordDecl>(LexDC)) &&
3211 isVisible(cast<NamedDecl>(DI))) {
3212 DeclaredInAssociatedClass = true;
3216 if (!DeclaredInAssociatedClass)
3220 if (isa<UsingShadowDecl>(D))
3221 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3223 if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D))
3226 if (!isVisible(D) && !(D = findAcceptableDecl(*this, D)))
3234 //----------------------------------------------------------------------------
3235 // Search for all visible declarations.
3236 //----------------------------------------------------------------------------
3237 VisibleDeclConsumer::~VisibleDeclConsumer() { }
3239 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
3243 class ShadowContextRAII;
3245 class VisibleDeclsRecord {
3247 /// \brief An entry in the shadow map, which is optimized to store a
3248 /// single declaration (the common case) but can also store a list
3249 /// of declarations.
3250 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
3253 /// \brief A mapping from declaration names to the declarations that have
3254 /// this name within a particular scope.
3255 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
3257 /// \brief A list of shadow maps, which is used to model name hiding.
3258 std::list<ShadowMap> ShadowMaps;
3260 /// \brief The declaration contexts we have already visited.
3261 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
3263 friend class ShadowContextRAII;
3266 /// \brief Determine whether we have already visited this context
3267 /// (and, if not, note that we are going to visit that context now).
3268 bool visitedContext(DeclContext *Ctx) {
3269 return !VisitedContexts.insert(Ctx).second;
3272 bool alreadyVisitedContext(DeclContext *Ctx) {
3273 return VisitedContexts.count(Ctx);
3276 /// \brief Determine whether the given declaration is hidden in the
3279 /// \returns the declaration that hides the given declaration, or
3280 /// NULL if no such declaration exists.
3281 NamedDecl *checkHidden(NamedDecl *ND);
3283 /// \brief Add a declaration to the current shadow map.
3284 void add(NamedDecl *ND) {
3285 ShadowMaps.back()[ND->getDeclName()].push_back(ND);
3289 /// \brief RAII object that records when we've entered a shadow context.
3290 class ShadowContextRAII {
3291 VisibleDeclsRecord &Visible;
3293 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
3296 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
3297 Visible.ShadowMaps.emplace_back();
3300 ~ShadowContextRAII() {
3301 Visible.ShadowMaps.pop_back();
3305 } // end anonymous namespace
3307 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
3308 unsigned IDNS = ND->getIdentifierNamespace();
3309 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
3310 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
3311 SM != SMEnd; ++SM) {
3312 ShadowMap::iterator Pos = SM->find(ND->getDeclName());
3313 if (Pos == SM->end())
3316 for (auto *D : Pos->second) {
3317 // A tag declaration does not hide a non-tag declaration.
3318 if (D->hasTagIdentifierNamespace() &&
3319 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
3320 Decl::IDNS_ObjCProtocol)))
3323 // Protocols are in distinct namespaces from everything else.
3324 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
3325 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
3326 D->getIdentifierNamespace() != IDNS)
3329 // Functions and function templates in the same scope overload
3330 // rather than hide. FIXME: Look for hiding based on function
3332 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3333 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3334 SM == ShadowMaps.rbegin())
3337 // We've found a declaration that hides this one.
3345 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
3346 bool QualifiedNameLookup,
3348 VisibleDeclConsumer &Consumer,
3349 VisibleDeclsRecord &Visited) {
3353 // Make sure we don't visit the same context twice.
3354 if (Visited.visitedContext(Ctx->getPrimaryContext()))
3357 // Outside C++, lookup results for the TU live on identifiers.
3358 if (isa<TranslationUnitDecl>(Ctx) &&
3359 !Result.getSema().getLangOpts().CPlusPlus) {
3360 auto &S = Result.getSema();
3361 auto &Idents = S.Context.Idents;
3363 // Ensure all external identifiers are in the identifier table.
3364 if (IdentifierInfoLookup *External = Idents.getExternalIdentifierLookup()) {
3365 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
3366 for (StringRef Name = Iter->Next(); !Name.empty(); Name = Iter->Next())
3370 // Walk all lookup results in the TU for each identifier.
3371 for (const auto &Ident : Idents) {
3372 for (auto I = S.IdResolver.begin(Ident.getValue()),
3373 E = S.IdResolver.end();
3375 if (S.IdResolver.isDeclInScope(*I, Ctx)) {
3376 if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
3377 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3387 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
3388 Result.getSema().ForceDeclarationOfImplicitMembers(Class);
3390 // Enumerate all of the results in this context.
3391 for (DeclContextLookupResult R : Ctx->lookups()) {
3393 if (auto *ND = Result.getAcceptableDecl(D)) {
3394 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3400 // Traverse using directives for qualified name lookup.
3401 if (QualifiedNameLookup) {
3402 ShadowContextRAII Shadow(Visited);
3403 for (auto I : Ctx->using_directives()) {
3404 LookupVisibleDecls(I->getNominatedNamespace(), Result,
3405 QualifiedNameLookup, InBaseClass, Consumer, Visited);
3409 // Traverse the contexts of inherited C++ classes.
3410 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
3411 if (!Record->hasDefinition())
3414 for (const auto &B : Record->bases()) {
3415 QualType BaseType = B.getType();
3417 // Don't look into dependent bases, because name lookup can't look
3419 if (BaseType->isDependentType())
3422 const RecordType *Record = BaseType->getAs<RecordType>();
3426 // FIXME: It would be nice to be able to determine whether referencing
3427 // a particular member would be ambiguous. For example, given
3429 // struct A { int member; };
3430 // struct B { int member; };
3431 // struct C : A, B { };
3433 // void f(C *c) { c->### }
3435 // accessing 'member' would result in an ambiguity. However, we
3436 // could be smart enough to qualify the member with the base
3445 // Find results in this base class (and its bases).
3446 ShadowContextRAII Shadow(Visited);
3447 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup,
3448 true, Consumer, Visited);
3452 // Traverse the contexts of Objective-C classes.
3453 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
3454 // Traverse categories.
3455 for (auto *Cat : IFace->visible_categories()) {
3456 ShadowContextRAII Shadow(Visited);
3457 LookupVisibleDecls(Cat, Result, QualifiedNameLookup, false,
3461 // Traverse protocols.
3462 for (auto *I : IFace->all_referenced_protocols()) {
3463 ShadowContextRAII Shadow(Visited);
3464 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3468 // Traverse the superclass.
3469 if (IFace->getSuperClass()) {
3470 ShadowContextRAII Shadow(Visited);
3471 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup,
3472 true, Consumer, Visited);
3475 // If there is an implementation, traverse it. We do this to find
3476 // synthesized ivars.
3477 if (IFace->getImplementation()) {
3478 ShadowContextRAII Shadow(Visited);
3479 LookupVisibleDecls(IFace->getImplementation(), Result,
3480 QualifiedNameLookup, InBaseClass, Consumer, Visited);
3482 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
3483 for (auto *I : Protocol->protocols()) {
3484 ShadowContextRAII Shadow(Visited);
3485 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3488 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
3489 for (auto *I : Category->protocols()) {
3490 ShadowContextRAII Shadow(Visited);
3491 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3495 // If there is an implementation, traverse it.
3496 if (Category->getImplementation()) {
3497 ShadowContextRAII Shadow(Visited);
3498 LookupVisibleDecls(Category->getImplementation(), Result,
3499 QualifiedNameLookup, true, Consumer, Visited);
3504 static void LookupVisibleDecls(Scope *S, LookupResult &Result,
3505 UnqualUsingDirectiveSet &UDirs,
3506 VisibleDeclConsumer &Consumer,
3507 VisibleDeclsRecord &Visited) {
3511 if (!S->getEntity() ||
3513 !Visited.alreadyVisitedContext(S->getEntity())) ||
3514 (S->getEntity())->isFunctionOrMethod()) {
3515 FindLocalExternScope FindLocals(Result);
3516 // Walk through the declarations in this Scope.
3517 for (auto *D : S->decls()) {
3518 if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
3519 if ((ND = Result.getAcceptableDecl(ND))) {
3520 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
3526 // FIXME: C++ [temp.local]p8
3527 DeclContext *Entity = nullptr;
3528 if (S->getEntity()) {
3529 // Look into this scope's declaration context, along with any of its
3530 // parent lookup contexts (e.g., enclosing classes), up to the point
3531 // where we hit the context stored in the next outer scope.
3532 Entity = S->getEntity();
3533 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME
3535 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
3536 Ctx = Ctx->getLookupParent()) {
3537 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
3538 if (Method->isInstanceMethod()) {
3539 // For instance methods, look for ivars in the method's interface.
3540 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
3541 Result.getNameLoc(), Sema::LookupMemberName);
3542 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
3543 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false,
3544 /*InBaseClass=*/false, Consumer, Visited);
3548 // We've already performed all of the name lookup that we need
3549 // to for Objective-C methods; the next context will be the
3554 if (Ctx->isFunctionOrMethod())
3557 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false,
3558 /*InBaseClass=*/false, Consumer, Visited);
3560 } else if (!S->getParent()) {
3561 // Look into the translation unit scope. We walk through the translation
3562 // unit's declaration context, because the Scope itself won't have all of
3563 // the declarations if we loaded a precompiled header.
3564 // FIXME: We would like the translation unit's Scope object to point to the
3565 // translation unit, so we don't need this special "if" branch. However,
3566 // doing so would force the normal C++ name-lookup code to look into the
3567 // translation unit decl when the IdentifierInfo chains would suffice.
3568 // Once we fix that problem (which is part of a more general "don't look
3569 // in DeclContexts unless we have to" optimization), we can eliminate this.
3570 Entity = Result.getSema().Context.getTranslationUnitDecl();
3571 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false,
3572 /*InBaseClass=*/false, Consumer, Visited);
3576 // Lookup visible declarations in any namespaces found by using
3578 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity))
3579 LookupVisibleDecls(const_cast<DeclContext *>(UUE.getNominatedNamespace()),
3580 Result, /*QualifiedNameLookup=*/false,
3581 /*InBaseClass=*/false, Consumer, Visited);
3584 // Lookup names in the parent scope.
3585 ShadowContextRAII Shadow(Visited);
3586 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited);
3589 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
3590 VisibleDeclConsumer &Consumer,
3591 bool IncludeGlobalScope) {
3592 // Determine the set of using directives available during
3593 // unqualified name lookup.
3595 UnqualUsingDirectiveSet UDirs;
3596 if (getLangOpts().CPlusPlus) {
3597 // Find the first namespace or translation-unit scope.
3598 while (S && !isNamespaceOrTranslationUnitScope(S))
3601 UDirs.visitScopeChain(Initial, S);
3605 // Look for visible declarations.
3606 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3607 Result.setAllowHidden(Consumer.includeHiddenDecls());
3608 VisibleDeclsRecord Visited;
3609 if (!IncludeGlobalScope)
3610 Visited.visitedContext(Context.getTranslationUnitDecl());
3611 ShadowContextRAII Shadow(Visited);
3612 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited);
3615 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
3616 VisibleDeclConsumer &Consumer,
3617 bool IncludeGlobalScope) {
3618 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3619 Result.setAllowHidden(Consumer.includeHiddenDecls());
3620 VisibleDeclsRecord Visited;
3621 if (!IncludeGlobalScope)
3622 Visited.visitedContext(Context.getTranslationUnitDecl());
3623 ShadowContextRAII Shadow(Visited);
3624 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true,
3625 /*InBaseClass=*/false, Consumer, Visited);
3628 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name.
3629 /// If GnuLabelLoc is a valid source location, then this is a definition
3630 /// of an __label__ label name, otherwise it is a normal label definition
3632 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc,
3633 SourceLocation GnuLabelLoc) {
3634 // Do a lookup to see if we have a label with this name already.
3635 NamedDecl *Res = nullptr;
3637 if (GnuLabelLoc.isValid()) {
3638 // Local label definitions always shadow existing labels.
3639 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
3640 Scope *S = CurScope;
3641 PushOnScopeChains(Res, S, true);
3642 return cast<LabelDecl>(Res);
3645 // Not a GNU local label.
3646 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration);
3647 // If we found a label, check to see if it is in the same context as us.
3648 // When in a Block, we don't want to reuse a label in an enclosing function.
3649 if (Res && Res->getDeclContext() != CurContext)
3652 // If not forward referenced or defined already, create the backing decl.
3653 Res = LabelDecl::Create(Context, CurContext, Loc, II);
3654 Scope *S = CurScope->getFnParent();
3655 assert(S && "Not in a function?");
3656 PushOnScopeChains(Res, S, true);
3658 return cast<LabelDecl>(Res);
3661 //===----------------------------------------------------------------------===//
3663 //===----------------------------------------------------------------------===//
3665 static bool isCandidateViable(CorrectionCandidateCallback &CCC,
3666 TypoCorrection &Candidate) {
3667 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
3668 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
3671 static void LookupPotentialTypoResult(Sema &SemaRef,
3673 IdentifierInfo *Name,
3674 Scope *S, CXXScopeSpec *SS,
3675 DeclContext *MemberContext,
3676 bool EnteringContext,
3677 bool isObjCIvarLookup,
3680 /// \brief Check whether the declarations found for a typo correction are
3681 /// visible, and if none of them are, convert the correction to an 'import
3682 /// a module' correction.
3683 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
3684 if (TC.begin() == TC.end())
3687 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
3689 for (/**/; DI != DE; ++DI)
3690 if (!LookupResult::isVisible(SemaRef, *DI))
3692 // Nothing to do if all decls are visible.
3696 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
3697 bool AnyVisibleDecls = !NewDecls.empty();
3699 for (/**/; DI != DE; ++DI) {
3700 NamedDecl *VisibleDecl = *DI;
3701 if (!LookupResult::isVisible(SemaRef, *DI))
3702 VisibleDecl = findAcceptableDecl(SemaRef, *DI);
3705 if (!AnyVisibleDecls) {
3706 // Found a visible decl, discard all hidden ones.
3707 AnyVisibleDecls = true;
3710 NewDecls.push_back(VisibleDecl);
3711 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
3712 NewDecls.push_back(*DI);
3715 if (NewDecls.empty())
3716 TC = TypoCorrection();
3718 TC.setCorrectionDecls(NewDecls);
3719 TC.setRequiresImport(!AnyVisibleDecls);
3723 // Fill the supplied vector with the IdentifierInfo pointers for each piece of
3724 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
3725 // fill the vector with the IdentifierInfo pointers for "foo" and "bar").
3726 static void getNestedNameSpecifierIdentifiers(
3727 NestedNameSpecifier *NNS,
3728 SmallVectorImpl<const IdentifierInfo*> &Identifiers) {
3729 if (NestedNameSpecifier *Prefix = NNS->getPrefix())
3730 getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
3732 Identifiers.clear();
3734 const IdentifierInfo *II = nullptr;
3736 switch (NNS->getKind()) {
3737 case NestedNameSpecifier::Identifier:
3738 II = NNS->getAsIdentifier();
3741 case NestedNameSpecifier::Namespace:
3742 if (NNS->getAsNamespace()->isAnonymousNamespace())
3744 II = NNS->getAsNamespace()->getIdentifier();
3747 case NestedNameSpecifier::NamespaceAlias:
3748 II = NNS->getAsNamespaceAlias()->getIdentifier();
3751 case NestedNameSpecifier::TypeSpecWithTemplate:
3752 case NestedNameSpecifier::TypeSpec:
3753 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier();
3756 case NestedNameSpecifier::Global:
3757 case NestedNameSpecifier::Super:
3762 Identifiers.push_back(II);
3765 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
3766 DeclContext *Ctx, bool InBaseClass) {
3767 // Don't consider hidden names for typo correction.
3771 // Only consider entities with identifiers for names, ignoring
3772 // special names (constructors, overloaded operators, selectors,
3774 IdentifierInfo *Name = ND->getIdentifier();
3778 // Only consider visible declarations and declarations from modules with
3779 // names that exactly match.
3780 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo &&
3781 !findAcceptableDecl(SemaRef, ND))
3784 FoundName(Name->getName());
3787 void TypoCorrectionConsumer::FoundName(StringRef Name) {
3788 // Compute the edit distance between the typo and the name of this
3789 // entity, and add the identifier to the list of results.
3790 addName(Name, nullptr);
3793 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) {
3794 // Compute the edit distance between the typo and this keyword,
3795 // and add the keyword to the list of results.
3796 addName(Keyword, nullptr, nullptr, true);
3799 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
3800 NestedNameSpecifier *NNS, bool isKeyword) {
3801 // Use a simple length-based heuristic to determine the minimum possible
3802 // edit distance. If the minimum isn't good enough, bail out early.
3803 StringRef TypoStr = Typo->getName();
3804 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
3805 if (MinED && TypoStr.size() / MinED < 3)
3808 // Compute an upper bound on the allowable edit distance, so that the
3809 // edit-distance algorithm can short-circuit.
3810 unsigned UpperBound = (TypoStr.size() + 2) / 3 + 1;
3811 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
3812 if (ED >= UpperBound) return;
3814 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
3815 if (isKeyword) TC.makeKeyword();
3816 TC.setCorrectionRange(nullptr, Result.getLookupNameInfo());
3820 static const unsigned MaxTypoDistanceResultSets = 5;
3822 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) {
3823 StringRef TypoStr = Typo->getName();
3824 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
3826 // For very short typos, ignore potential corrections that have a different
3827 // base identifier from the typo or which have a normalized edit distance
3828 // longer than the typo itself.
3829 if (TypoStr.size() < 3 &&
3830 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
3833 // If the correction is resolved but is not viable, ignore it.
3834 if (Correction.isResolved()) {
3835 checkCorrectionVisibility(SemaRef, Correction);
3836 if (!Correction || !isCandidateViable(*CorrectionValidator, Correction))
3840 TypoResultList &CList =
3841 CorrectionResults[Correction.getEditDistance(false)][Name];
3843 if (!CList.empty() && !CList.back().isResolved())
3845 if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
3846 std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts());
3847 for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end();
3848 RI != RIEnd; ++RI) {
3849 // If the Correction refers to a decl already in the result list,
3850 // replace the existing result if the string representation of Correction
3851 // comes before the current result alphabetically, then stop as there is
3852 // nothing more to be done to add Correction to the candidate set.
3853 if (RI->getCorrectionDecl() == NewND) {
3854 if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts()))
3860 if (CList.empty() || Correction.isResolved())
3861 CList.push_back(Correction);
3863 while (CorrectionResults.size() > MaxTypoDistanceResultSets)
3864 CorrectionResults.erase(std::prev(CorrectionResults.end()));
3867 void TypoCorrectionConsumer::addNamespaces(
3868 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
3869 SearchNamespaces = true;
3871 for (auto KNPair : KnownNamespaces)
3872 Namespaces.addNameSpecifier(KNPair.first);
3874 bool SSIsTemplate = false;
3875 if (NestedNameSpecifier *NNS =
3876 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) {
3877 if (const Type *T = NNS->getAsType())
3878 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization;
3880 // Do not transform this into an iterator-based loop. The loop body can
3881 // trigger the creation of further types (through lazy deserialization) and
3882 // invalide iterators into this list.
3883 auto &Types = SemaRef.getASTContext().getTypes();
3884 for (unsigned I = 0; I != Types.size(); ++I) {
3885 const auto *TI = Types[I];
3886 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
3887 CD = CD->getCanonicalDecl();
3888 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
3889 !CD->isUnion() && CD->getIdentifier() &&
3890 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
3891 (CD->isBeingDefined() || CD->isCompleteDefinition()))
3892 Namespaces.addNameSpecifier(CD);
3897 const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() {
3898 if (++CurrentTCIndex < ValidatedCorrections.size())
3899 return ValidatedCorrections[CurrentTCIndex];
3901 CurrentTCIndex = ValidatedCorrections.size();
3902 while (!CorrectionResults.empty()) {
3903 auto DI = CorrectionResults.begin();
3904 if (DI->second.empty()) {
3905 CorrectionResults.erase(DI);
3909 auto RI = DI->second.begin();
3910 if (RI->second.empty()) {
3911 DI->second.erase(RI);
3912 performQualifiedLookups();
3916 TypoCorrection TC = RI->second.pop_back_val();
3917 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) {
3918 ValidatedCorrections.push_back(TC);
3919 return ValidatedCorrections[CurrentTCIndex];
3922 return ValidatedCorrections[0]; // The empty correction.
3925 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
3926 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
3927 DeclContext *TempMemberContext = MemberContext;
3928 CXXScopeSpec *TempSS = SS.get();
3930 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
3932 CorrectionValidator->IsObjCIvarLookup,
3933 Name == Typo && !Candidate.WillReplaceSpecifier());
3934 switch (Result.getResultKind()) {
3935 case LookupResult::NotFound:
3936 case LookupResult::NotFoundInCurrentInstantiation:
3937 case LookupResult::FoundUnresolvedValue:
3939 // Immediately retry the lookup without the given CXXScopeSpec
3941 Candidate.WillReplaceSpecifier(true);
3944 if (TempMemberContext) {
3947 TempMemberContext = nullptr;
3950 if (SearchNamespaces)
3951 QualifiedResults.push_back(Candidate);
3954 case LookupResult::Ambiguous:
3955 // We don't deal with ambiguities.
3958 case LookupResult::Found:
3959 case LookupResult::FoundOverloaded:
3960 // Store all of the Decls for overloaded symbols
3961 for (auto *TRD : Result)
3962 Candidate.addCorrectionDecl(TRD);
3963 checkCorrectionVisibility(SemaRef, Candidate);
3964 if (!isCandidateViable(*CorrectionValidator, Candidate)) {
3965 if (SearchNamespaces)
3966 QualifiedResults.push_back(Candidate);
3969 Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
3975 void TypoCorrectionConsumer::performQualifiedLookups() {
3976 unsigned TypoLen = Typo->getName().size();
3977 for (auto QR : QualifiedResults) {
3978 for (auto NSI : Namespaces) {
3979 DeclContext *Ctx = NSI.DeclCtx;
3980 const Type *NSType = NSI.NameSpecifier->getAsType();
3982 // If the current NestedNameSpecifier refers to a class and the
3983 // current correction candidate is the name of that class, then skip
3984 // it as it is unlikely a qualified version of the class' constructor
3985 // is an appropriate correction.
3986 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() :
3988 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
3992 TypoCorrection TC(QR);
3993 TC.ClearCorrectionDecls();
3994 TC.setCorrectionSpecifier(NSI.NameSpecifier);
3995 TC.setQualifierDistance(NSI.EditDistance);
3996 TC.setCallbackDistance(0); // Reset the callback distance
3998 // If the current correction candidate and namespace combination are
3999 // too far away from the original typo based on the normalized edit
4000 // distance, then skip performing a qualified name lookup.
4001 unsigned TmpED = TC.getEditDistance(true);
4002 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4003 TypoLen / TmpED < 3)
4007 Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4008 if (!SemaRef.LookupQualifiedName(Result, Ctx))
4011 // Any corrections added below will be validated in subsequent
4012 // iterations of the main while() loop over the Consumer's contents.
4013 switch (Result.getResultKind()) {
4014 case LookupResult::Found:
4015 case LookupResult::FoundOverloaded: {
4016 if (SS && SS->isValid()) {
4017 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
4018 std::string OldQualified;
4019 llvm::raw_string_ostream OldOStream(OldQualified);
4020 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy());
4021 OldOStream << Typo->getName();
4022 // If correction candidate would be an identical written qualified
4023 // identifer, then the existing CXXScopeSpec probably included a
4024 // typedef that didn't get accounted for properly.
4025 if (OldOStream.str() == NewQualified)
4028 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4029 TRD != TRDEnd; ++TRD) {
4030 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
4031 NSType ? NSType->getAsCXXRecordDecl()
4033 TRD.getPair()) == Sema::AR_accessible)
4034 TC.addCorrectionDecl(*TRD);
4036 if (TC.isResolved()) {
4037 TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4042 case LookupResult::NotFound:
4043 case LookupResult::NotFoundInCurrentInstantiation:
4044 case LookupResult::Ambiguous:
4045 case LookupResult::FoundUnresolvedValue:
4050 QualifiedResults.clear();
4053 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4054 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4055 : Context(Context), CurContextChain(buildContextChain(CurContext)) {
4056 if (NestedNameSpecifier *NNS =
4057 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) {
4058 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4059 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4061 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
4063 // Build the list of identifiers that would be used for an absolute
4064 // (from the global context) NestedNameSpecifier referring to the current
4066 for (DeclContextList::reverse_iterator C = CurContextChain.rbegin(),
4067 CEnd = CurContextChain.rend();
4069 if (NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(*C))
4070 CurContextIdentifiers.push_back(ND->getIdentifier());
4073 // Add the global context as a NestedNameSpecifier
4074 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
4075 NestedNameSpecifier::GlobalSpecifier(Context), 1};
4076 DistanceMap[1].push_back(SI);
4079 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
4080 DeclContext *Start) -> DeclContextList {
4081 assert(Start && "Building a context chain from a null context");
4082 DeclContextList Chain;
4083 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
4084 DC = DC->getLookupParent()) {
4085 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
4086 if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
4087 !(ND && ND->isAnonymousNamespace()))
4088 Chain.push_back(DC->getPrimaryContext());
4094 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
4095 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) {
4096 unsigned NumSpecifiers = 0;
4097 for (DeclContextList::reverse_iterator C = DeclChain.rbegin(),
4098 CEnd = DeclChain.rend();
4100 if (NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(*C)) {
4101 NNS = NestedNameSpecifier::Create(Context, NNS, ND);
4103 } else if (RecordDecl *RD = dyn_cast_or_null<RecordDecl>(*C)) {
4104 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(),
4105 RD->getTypeForDecl());
4109 return NumSpecifiers;
4112 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
4114 NestedNameSpecifier *NNS = nullptr;
4115 unsigned NumSpecifiers = 0;
4116 DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
4117 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
4119 // Eliminate common elements from the two DeclContext chains.
4120 for (DeclContextList::reverse_iterator C = CurContextChain.rbegin(),
4121 CEnd = CurContextChain.rend();
4122 C != CEnd && !NamespaceDeclChain.empty() &&
4123 NamespaceDeclChain.back() == *C; ++C) {
4124 NamespaceDeclChain.pop_back();
4127 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
4128 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
4130 // Add an explicit leading '::' specifier if needed.
4131 if (NamespaceDeclChain.empty()) {
4132 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4133 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4135 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4136 } else if (NamedDecl *ND =
4137 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
4138 IdentifierInfo *Name = ND->getIdentifier();
4139 bool SameNameSpecifier = false;
4140 if (std::find(CurNameSpecifierIdentifiers.begin(),
4141 CurNameSpecifierIdentifiers.end(),
4142 Name) != CurNameSpecifierIdentifiers.end()) {
4143 std::string NewNameSpecifier;
4144 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
4145 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
4146 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4147 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4148 SpecifierOStream.flush();
4149 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
4151 if (SameNameSpecifier ||
4152 std::find(CurContextIdentifiers.begin(), CurContextIdentifiers.end(),
4153 Name) != CurContextIdentifiers.end()) {
4154 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4155 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4157 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4161 // If the built NestedNameSpecifier would be replacing an existing
4162 // NestedNameSpecifier, use the number of component identifiers that
4163 // would need to be changed as the edit distance instead of the number
4164 // of components in the built NestedNameSpecifier.
4165 if (NNS && !CurNameSpecifierIdentifiers.empty()) {
4166 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
4167 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4168 NumSpecifiers = llvm::ComputeEditDistance(
4169 llvm::makeArrayRef(CurNameSpecifierIdentifiers),
4170 llvm::makeArrayRef(NewNameSpecifierIdentifiers));
4173 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
4174 DistanceMap[NumSpecifiers].push_back(SI);
4177 /// \brief Perform name lookup for a possible result for typo correction.
4178 static void LookupPotentialTypoResult(Sema &SemaRef,
4180 IdentifierInfo *Name,
4181 Scope *S, CXXScopeSpec *SS,
4182 DeclContext *MemberContext,
4183 bool EnteringContext,
4184 bool isObjCIvarLookup,
4186 Res.suppressDiagnostics();
4188 Res.setLookupName(Name);
4189 Res.setAllowHidden(FindHidden);
4190 if (MemberContext) {
4191 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
4192 if (isObjCIvarLookup) {
4193 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
4200 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(Name)) {
4207 SemaRef.LookupQualifiedName(Res, MemberContext);
4211 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
4214 // Fake ivar lookup; this should really be part of
4215 // LookupParsedName.
4216 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
4217 if (Method->isInstanceMethod() && Method->getClassInterface() &&
4219 (Res.isSingleResult() &&
4220 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) {
4221 if (ObjCIvarDecl *IV
4222 = Method->getClassInterface()->lookupInstanceVariable(Name)) {
4230 /// \brief Add keywords to the consumer as possible typo corrections.
4231 static void AddKeywordsToConsumer(Sema &SemaRef,
4232 TypoCorrectionConsumer &Consumer,
4233 Scope *S, CorrectionCandidateCallback &CCC,
4234 bool AfterNestedNameSpecifier) {
4235 if (AfterNestedNameSpecifier) {
4236 // For 'X::', we know exactly which keywords can appear next.
4237 Consumer.addKeywordResult("template");
4238 if (CCC.WantExpressionKeywords)
4239 Consumer.addKeywordResult("operator");
4243 if (CCC.WantObjCSuper)
4244 Consumer.addKeywordResult("super");
4246 if (CCC.WantTypeSpecifiers) {
4247 // Add type-specifier keywords to the set of results.
4248 static const char *const CTypeSpecs[] = {
4249 "char", "const", "double", "enum", "float", "int", "long", "short",
4250 "signed", "struct", "union", "unsigned", "void", "volatile",
4251 "_Complex", "_Imaginary",
4252 // storage-specifiers as well
4253 "extern", "inline", "static", "typedef"
4256 const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs);
4257 for (unsigned I = 0; I != NumCTypeSpecs; ++I)
4258 Consumer.addKeywordResult(CTypeSpecs[I]);
4260 if (SemaRef.getLangOpts().C99)
4261 Consumer.addKeywordResult("restrict");
4262 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
4263 Consumer.addKeywordResult("bool");
4264 else if (SemaRef.getLangOpts().C99)
4265 Consumer.addKeywordResult("_Bool");
4267 if (SemaRef.getLangOpts().CPlusPlus) {
4268 Consumer.addKeywordResult("class");
4269 Consumer.addKeywordResult("typename");
4270 Consumer.addKeywordResult("wchar_t");
4272 if (SemaRef.getLangOpts().CPlusPlus11) {
4273 Consumer.addKeywordResult("char16_t");
4274 Consumer.addKeywordResult("char32_t");
4275 Consumer.addKeywordResult("constexpr");
4276 Consumer.addKeywordResult("decltype");
4277 Consumer.addKeywordResult("thread_local");
4281 if (SemaRef.getLangOpts().GNUMode)
4282 Consumer.addKeywordResult("typeof");
4283 } else if (CCC.WantFunctionLikeCasts) {
4284 static const char *const CastableTypeSpecs[] = {
4285 "char", "double", "float", "int", "long", "short",
4286 "signed", "unsigned", "void"
4288 for (auto *kw : CastableTypeSpecs)
4289 Consumer.addKeywordResult(kw);
4292 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
4293 Consumer.addKeywordResult("const_cast");
4294 Consumer.addKeywordResult("dynamic_cast");
4295 Consumer.addKeywordResult("reinterpret_cast");
4296 Consumer.addKeywordResult("static_cast");
4299 if (CCC.WantExpressionKeywords) {
4300 Consumer.addKeywordResult("sizeof");
4301 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
4302 Consumer.addKeywordResult("false");
4303 Consumer.addKeywordResult("true");
4306 if (SemaRef.getLangOpts().CPlusPlus) {
4307 static const char *const CXXExprs[] = {
4308 "delete", "new", "operator", "throw", "typeid"
4310 const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs);
4311 for (unsigned I = 0; I != NumCXXExprs; ++I)
4312 Consumer.addKeywordResult(CXXExprs[I]);
4314 if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
4315 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
4316 Consumer.addKeywordResult("this");
4318 if (SemaRef.getLangOpts().CPlusPlus11) {
4319 Consumer.addKeywordResult("alignof");
4320 Consumer.addKeywordResult("nullptr");
4324 if (SemaRef.getLangOpts().C11) {
4325 // FIXME: We should not suggest _Alignof if the alignof macro
4327 Consumer.addKeywordResult("_Alignof");
4331 if (CCC.WantRemainingKeywords) {
4332 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
4334 static const char *const CStmts[] = {
4335 "do", "else", "for", "goto", "if", "return", "switch", "while" };
4336 const unsigned NumCStmts = llvm::array_lengthof(CStmts);
4337 for (unsigned I = 0; I != NumCStmts; ++I)
4338 Consumer.addKeywordResult(CStmts[I]);
4340 if (SemaRef.getLangOpts().CPlusPlus) {
4341 Consumer.addKeywordResult("catch");
4342 Consumer.addKeywordResult("try");
4345 if (S && S->getBreakParent())
4346 Consumer.addKeywordResult("break");
4348 if (S && S->getContinueParent())
4349 Consumer.addKeywordResult("continue");
4351 if (!SemaRef.getCurFunction()->SwitchStack.empty()) {
4352 Consumer.addKeywordResult("case");
4353 Consumer.addKeywordResult("default");
4356 if (SemaRef.getLangOpts().CPlusPlus) {
4357 Consumer.addKeywordResult("namespace");
4358 Consumer.addKeywordResult("template");
4361 if (S && S->isClassScope()) {
4362 Consumer.addKeywordResult("explicit");
4363 Consumer.addKeywordResult("friend");
4364 Consumer.addKeywordResult("mutable");
4365 Consumer.addKeywordResult("private");
4366 Consumer.addKeywordResult("protected");
4367 Consumer.addKeywordResult("public");
4368 Consumer.addKeywordResult("virtual");
4372 if (SemaRef.getLangOpts().CPlusPlus) {
4373 Consumer.addKeywordResult("using");
4375 if (SemaRef.getLangOpts().CPlusPlus11)
4376 Consumer.addKeywordResult("static_assert");
4381 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
4382 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4383 Scope *S, CXXScopeSpec *SS,
4384 std::unique_ptr<CorrectionCandidateCallback> CCC,
4385 DeclContext *MemberContext, bool EnteringContext,
4386 const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
4388 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
4389 DisableTypoCorrection)
4392 // In Microsoft mode, don't perform typo correction in a template member
4393 // function dependent context because it interferes with the "lookup into
4394 // dependent bases of class templates" feature.
4395 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
4396 isa<CXXMethodDecl>(CurContext))
4399 // We only attempt to correct typos for identifiers.
4400 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4404 // If the scope specifier itself was invalid, don't try to correct
4406 if (SS && SS->isInvalid())
4409 // Never try to correct typos during template deduction or
4411 if (!ActiveTemplateInstantiations.empty())
4414 // Don't try to correct 'super'.
4415 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
4418 // Abort if typo correction already failed for this specific typo.
4419 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
4420 if (locs != TypoCorrectionFailures.end() &&
4421 locs->second.count(TypoName.getLoc()))
4424 // Don't try to correct the identifier "vector" when in AltiVec mode.
4425 // TODO: Figure out why typo correction misbehaves in this case, fix it, and
4426 // remove this workaround.
4427 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector"))
4430 // Provide a stop gap for files that are just seriously broken. Trying
4431 // to correct all typos can turn into a HUGE performance penalty, causing
4432 // some files to take minutes to get rejected by the parser.
4433 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
4434 if (Limit && TyposCorrected >= Limit)
4438 // If we're handling a missing symbol error, using modules, and the
4439 // special search all modules option is used, look for a missing import.
4440 if (ErrorRecovery && getLangOpts().Modules &&
4441 getLangOpts().ModulesSearchAll) {
4442 // The following has the side effect of loading the missing module.
4443 getModuleLoader().lookupMissingImports(Typo->getName(),
4444 TypoName.getLocStart());
4447 CorrectionCandidateCallback &CCCRef = *CCC;
4448 auto Consumer = llvm::make_unique<TypoCorrectionConsumer>(
4449 *this, TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4452 // Perform name lookup to find visible, similarly-named entities.
4453 bool IsUnqualifiedLookup = false;
4454 DeclContext *QualifiedDC = MemberContext;
4455 if (MemberContext) {
4456 LookupVisibleDecls(MemberContext, LookupKind, *Consumer);
4458 // Look in qualified interfaces.
4460 for (auto *I : OPT->quals())
4461 LookupVisibleDecls(I, LookupKind, *Consumer);
4463 } else if (SS && SS->isSet()) {
4464 QualifiedDC = computeDeclContext(*SS, EnteringContext);
4468 LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer);
4470 IsUnqualifiedLookup = true;
4473 // Determine whether we are going to search in the various namespaces for
4475 bool SearchNamespaces
4476 = getLangOpts().CPlusPlus &&
4477 (IsUnqualifiedLookup || (SS && SS->isSet()));
4479 if (IsUnqualifiedLookup || SearchNamespaces) {
4480 // For unqualified lookup, look through all of the names that we have
4481 // seen in this translation unit.
4482 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4483 for (const auto &I : Context.Idents)
4484 Consumer->FoundName(I.getKey());
4486 // Walk through identifiers in external identifier sources.
4487 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4488 if (IdentifierInfoLookup *External
4489 = Context.Idents.getExternalIdentifierLookup()) {
4490 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4492 StringRef Name = Iter->Next();
4496 Consumer->FoundName(Name);
4501 AddKeywordsToConsumer(*this, *Consumer, S, CCCRef, SS && SS->isNotEmpty());
4503 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
4504 // to search those namespaces.
4505 if (SearchNamespaces) {
4506 // Load any externally-known namespaces.
4507 if (ExternalSource && !LoadedExternalKnownNamespaces) {
4508 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
4509 LoadedExternalKnownNamespaces = true;
4510 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
4511 for (auto *N : ExternalKnownNamespaces)
4512 KnownNamespaces[N] = true;
4515 Consumer->addNamespaces(KnownNamespaces);
4521 /// \brief Try to "correct" a typo in the source code by finding
4522 /// visible declarations whose names are similar to the name that was
4523 /// present in the source code.
4525 /// \param TypoName the \c DeclarationNameInfo structure that contains
4526 /// the name that was present in the source code along with its location.
4528 /// \param LookupKind the name-lookup criteria used to search for the name.
4530 /// \param S the scope in which name lookup occurs.
4532 /// \param SS the nested-name-specifier that precedes the name we're
4533 /// looking for, if present.
4535 /// \param CCC A CorrectionCandidateCallback object that provides further
4536 /// validation of typo correction candidates. It also provides flags for
4537 /// determining the set of keywords permitted.
4539 /// \param MemberContext if non-NULL, the context in which to look for
4540 /// a member access expression.
4542 /// \param EnteringContext whether we're entering the context described by
4543 /// the nested-name-specifier SS.
4545 /// \param OPT when non-NULL, the search for visible declarations will
4546 /// also walk the protocols in the qualified interfaces of \p OPT.
4548 /// \returns a \c TypoCorrection containing the corrected name if the typo
4549 /// along with information such as the \c NamedDecl where the corrected name
4550 /// was declared, and any additional \c NestedNameSpecifier needed to access
4551 /// it (C++ only). The \c TypoCorrection is empty if there is no correction.
4552 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
4553 Sema::LookupNameKind LookupKind,
4554 Scope *S, CXXScopeSpec *SS,
4555 std::unique_ptr<CorrectionCandidateCallback> CCC,
4556 CorrectTypoKind Mode,
4557 DeclContext *MemberContext,
4558 bool EnteringContext,
4559 const ObjCObjectPointerType *OPT,
4560 bool RecordFailure) {
4561 assert(CCC && "CorrectTypo requires a CorrectionCandidateCallback");
4563 // Always let the ExternalSource have the first chance at correction, even
4564 // if we would otherwise have given up.
4565 if (ExternalSource) {
4566 if (TypoCorrection Correction = ExternalSource->CorrectTypo(
4567 TypoName, LookupKind, S, SS, *CCC, MemberContext, EnteringContext, OPT))
4571 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
4572 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
4573 // some instances of CTC_Unknown, while WantRemainingKeywords is true
4574 // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
4575 bool ObjCMessageReceiver = CCC->WantObjCSuper && !CCC->WantRemainingKeywords;
4577 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4578 auto Consumer = makeTypoCorrectionConsumer(
4579 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4580 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4583 return TypoCorrection();
4585 // If we haven't found anything, we're done.
4586 if (Consumer->empty())
4587 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4589 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4590 // is not more that about a third of the length of the typo's identifier.
4591 unsigned ED = Consumer->getBestEditDistance(true);
4592 unsigned TypoLen = Typo->getName().size();
4593 if (ED > 0 && TypoLen / ED < 3)
4594 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4596 TypoCorrection BestTC = Consumer->getNextCorrection();
4597 TypoCorrection SecondBestTC = Consumer->getNextCorrection();
4599 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4601 ED = BestTC.getEditDistance();
4603 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
4604 // If this was an unqualified lookup and we believe the callback
4605 // object wouldn't have filtered out possible corrections, note
4606 // that no correction was found.
4607 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4610 // If only a single name remains, return that result.
4611 if (!SecondBestTC ||
4612 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
4613 const TypoCorrection &Result = BestTC;
4615 // Don't correct to a keyword that's the same as the typo; the keyword
4616 // wasn't actually in scope.
4617 if (ED == 0 && Result.isKeyword())
4618 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4620 TypoCorrection TC = Result;
4621 TC.setCorrectionRange(SS, TypoName);
4622 checkCorrectionVisibility(*this, TC);
4624 } else if (SecondBestTC && ObjCMessageReceiver) {
4625 // Prefer 'super' when we're completing in a message-receiver
4628 if (BestTC.getCorrection().getAsString() != "super") {
4629 if (SecondBestTC.getCorrection().getAsString() == "super")
4630 BestTC = SecondBestTC;
4631 else if ((*Consumer)["super"].front().isKeyword())
4632 BestTC = (*Consumer)["super"].front();
4634 // Don't correct to a keyword that's the same as the typo; the keyword
4635 // wasn't actually in scope.
4636 if (BestTC.getEditDistance() == 0 ||
4637 BestTC.getCorrection().getAsString() != "super")
4638 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4640 BestTC.setCorrectionRange(SS, TypoName);
4644 // Record the failure's location if needed and return an empty correction. If
4645 // this was an unqualified lookup and we believe the callback object did not
4646 // filter out possible corrections, also cache the failure for the typo.
4647 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC);
4650 /// \brief Try to "correct" a typo in the source code by finding
4651 /// visible declarations whose names are similar to the name that was
4652 /// present in the source code.
4654 /// \param TypoName the \c DeclarationNameInfo structure that contains
4655 /// the name that was present in the source code along with its location.
4657 /// \param LookupKind the name-lookup criteria used to search for the name.
4659 /// \param S the scope in which name lookup occurs.
4661 /// \param SS the nested-name-specifier that precedes the name we're
4662 /// looking for, if present.
4664 /// \param CCC A CorrectionCandidateCallback object that provides further
4665 /// validation of typo correction candidates. It also provides flags for
4666 /// determining the set of keywords permitted.
4668 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print
4669 /// diagnostics when the actual typo correction is attempted.
4671 /// \param TRC A TypoRecoveryCallback functor that will be used to build an
4672 /// Expr from a typo correction candidate.
4674 /// \param MemberContext if non-NULL, the context in which to look for
4675 /// a member access expression.
4677 /// \param EnteringContext whether we're entering the context described by
4678 /// the nested-name-specifier SS.
4680 /// \param OPT when non-NULL, the search for visible declarations will
4681 /// also walk the protocols in the qualified interfaces of \p OPT.
4683 /// \returns a new \c TypoExpr that will later be replaced in the AST with an
4684 /// Expr representing the result of performing typo correction, or nullptr if
4685 /// typo correction is not possible. If nullptr is returned, no diagnostics will
4686 /// be emitted and it is the responsibility of the caller to emit any that are
4688 TypoExpr *Sema::CorrectTypoDelayed(
4689 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4690 Scope *S, CXXScopeSpec *SS,
4691 std::unique_ptr<CorrectionCandidateCallback> CCC,
4692 TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode,
4693 DeclContext *MemberContext, bool EnteringContext,
4694 const ObjCObjectPointerType *OPT) {
4695 assert(CCC && "CorrectTypoDelayed requires a CorrectionCandidateCallback");
4697 TypoCorrection Empty;
4698 auto Consumer = makeTypoCorrectionConsumer(
4699 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4700 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4702 if (!Consumer || Consumer->empty())
4705 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4706 // is not more that about a third of the length of the typo's identifier.
4707 unsigned ED = Consumer->getBestEditDistance(true);
4708 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4709 if (ED > 0 && Typo->getName().size() / ED < 3)
4712 ExprEvalContexts.back().NumTypos++;
4713 return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC));
4716 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) {
4720 CorrectionDecls.clear();
4722 CorrectionDecls.push_back(CDecl);
4724 if (!CorrectionName)
4725 CorrectionName = CDecl->getDeclName();
4728 std::string TypoCorrection::getAsString(const LangOptions &LO) const {
4729 if (CorrectionNameSpec) {
4730 std::string tmpBuffer;
4731 llvm::raw_string_ostream PrefixOStream(tmpBuffer);
4732 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO));
4733 PrefixOStream << CorrectionName;
4734 return PrefixOStream.str();
4737 return CorrectionName.getAsString();
4740 bool CorrectionCandidateCallback::ValidateCandidate(
4741 const TypoCorrection &candidate) {
4742 if (!candidate.isResolved())
4745 if (candidate.isKeyword())
4746 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
4747 WantRemainingKeywords || WantObjCSuper;
4749 bool HasNonType = false;
4750 bool HasStaticMethod = false;
4751 bool HasNonStaticMethod = false;
4752 for (Decl *D : candidate) {
4753 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
4754 D = FTD->getTemplatedDecl();
4755 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
4756 if (Method->isStatic())
4757 HasStaticMethod = true;
4759 HasNonStaticMethod = true;
4761 if (!isa<TypeDecl>(D))
4765 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
4766 !candidate.getCorrectionSpecifier())
4769 return WantTypeSpecifiers || HasNonType;
4772 FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs,
4773 bool HasExplicitTemplateArgs,
4775 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
4776 CurContext(SemaRef.CurContext), MemberFn(ME) {
4777 WantTypeSpecifiers = false;
4778 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && NumArgs == 1;
4779 WantRemainingKeywords = false;
4782 bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) {
4783 if (!candidate.getCorrectionDecl())
4784 return candidate.isKeyword();
4786 for (auto *C : candidate) {
4787 FunctionDecl *FD = nullptr;
4788 NamedDecl *ND = C->getUnderlyingDecl();
4789 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
4790 FD = FTD->getTemplatedDecl();
4791 if (!HasExplicitTemplateArgs && !FD) {
4792 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
4793 // If the Decl is neither a function nor a template function,
4794 // determine if it is a pointer or reference to a function. If so,
4795 // check against the number of arguments expected for the pointee.
4796 QualType ValType = cast<ValueDecl>(ND)->getType();
4797 if (ValType->isAnyPointerType() || ValType->isReferenceType())
4798 ValType = ValType->getPointeeType();
4799 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
4800 if (FPT->getNumParams() == NumArgs)
4805 // Skip the current candidate if it is not a FunctionDecl or does not accept
4806 // the current number of arguments.
4807 if (!FD || !(FD->getNumParams() >= NumArgs &&
4808 FD->getMinRequiredArguments() <= NumArgs))
4811 // If the current candidate is a non-static C++ method, skip the candidate
4812 // unless the method being corrected--or the current DeclContext, if the
4813 // function being corrected is not a method--is a method in the same class
4814 // or a descendent class of the candidate's parent class.
4815 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
4816 if (MemberFn || !MD->isStatic()) {
4817 CXXMethodDecl *CurMD =
4819 ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl())
4820 : dyn_cast_or_null<CXXMethodDecl>(CurContext);
4821 CXXRecordDecl *CurRD =
4822 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
4823 CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
4824 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
4833 void Sema::diagnoseTypo(const TypoCorrection &Correction,
4834 const PartialDiagnostic &TypoDiag,
4835 bool ErrorRecovery) {
4836 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
4840 /// Find which declaration we should import to provide the definition of
4841 /// the given declaration.
4842 static NamedDecl *getDefinitionToImport(NamedDecl *D) {
4843 if (VarDecl *VD = dyn_cast<VarDecl>(D))
4844 return VD->getDefinition();
4845 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
4846 return FD->isDefined(FD) ? const_cast<FunctionDecl*>(FD) : nullptr;
4847 if (TagDecl *TD = dyn_cast<TagDecl>(D))
4848 return TD->getDefinition();
4849 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
4850 return ID->getDefinition();
4851 if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
4852 return PD->getDefinition();
4853 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
4854 return getDefinitionToImport(TD->getTemplatedDecl());
4858 void Sema::diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl,
4859 bool NeedDefinition, bool Recover) {
4860 assert(!isVisible(Decl) && "missing import for non-hidden decl?");
4862 // Suggest importing a module providing the definition of this entity, if
4864 NamedDecl *Def = getDefinitionToImport(Decl);
4868 // FIXME: Add a Fix-It that imports the corresponding module or includes
4870 Module *Owner = getOwningModule(Decl);
4871 assert(Owner && "definition of hidden declaration is not in a module");
4873 llvm::SmallVector<Module*, 8> OwningModules;
4874 OwningModules.push_back(Owner);
4875 auto Merged = Context.getModulesWithMergedDefinition(Decl);
4876 OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end());
4878 diagnoseMissingImport(Loc, Decl, Decl->getLocation(), OwningModules,
4879 NeedDefinition ? MissingImportKind::Definition
4880 : MissingImportKind::Declaration,
4884 void Sema::diagnoseMissingImport(SourceLocation UseLoc, NamedDecl *Decl,
4885 SourceLocation DeclLoc,
4886 ArrayRef<Module *> Modules,
4887 MissingImportKind MIK, bool Recover) {
4888 assert(!Modules.empty());
4890 if (Modules.size() > 1) {
4891 std::string ModuleList;
4893 for (Module *M : Modules) {
4894 ModuleList += "\n ";
4895 if (++N == 5 && N != Modules.size()) {
4896 ModuleList += "[...]";
4899 ModuleList += M->getFullModuleName();
4902 Diag(UseLoc, diag::err_module_unimported_use_multiple)
4903 << (int)MIK << Decl << ModuleList;
4905 Diag(UseLoc, diag::err_module_unimported_use)
4906 << (int)MIK << Decl << Modules[0]->getFullModuleName();
4911 case MissingImportKind::Declaration:
4912 DiagID = diag::note_previous_declaration;
4914 case MissingImportKind::Definition:
4915 DiagID = diag::note_previous_definition;
4917 case MissingImportKind::DefaultArgument:
4918 DiagID = diag::note_default_argument_declared_here;
4921 Diag(DeclLoc, DiagID);
4923 // Try to recover by implicitly importing this module.
4925 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
4928 /// \brief Diagnose a successfully-corrected typo. Separated from the correction
4929 /// itself to allow external validation of the result, etc.
4931 /// \param Correction The result of performing typo correction.
4932 /// \param TypoDiag The diagnostic to produce. This will have the corrected
4933 /// string added to it (and usually also a fixit).
4934 /// \param PrevNote A note to use when indicating the location of the entity to
4935 /// which we are correcting. Will have the correction string added to it.
4936 /// \param ErrorRecovery If \c true (the default), the caller is going to
4937 /// recover from the typo as if the corrected string had been typed.
4938 /// In this case, \c PDiag must be an error, and we will attach a fixit
4940 void Sema::diagnoseTypo(const TypoCorrection &Correction,
4941 const PartialDiagnostic &TypoDiag,
4942 const PartialDiagnostic &PrevNote,
4943 bool ErrorRecovery) {
4944 std::string CorrectedStr = Correction.getAsString(getLangOpts());
4945 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
4946 FixItHint FixTypo = FixItHint::CreateReplacement(
4947 Correction.getCorrectionRange(), CorrectedStr);
4949 // Maybe we're just missing a module import.
4950 if (Correction.requiresImport()) {
4951 NamedDecl *Decl = Correction.getFoundDecl();
4952 assert(Decl && "import required but no declaration to import");
4954 diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl,
4955 /*NeedDefinition*/ false, ErrorRecovery);
4959 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
4960 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
4962 NamedDecl *ChosenDecl =
4963 Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
4964 if (PrevNote.getDiagID() && ChosenDecl)
4965 Diag(ChosenDecl->getLocation(), PrevNote)
4966 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
4969 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
4970 TypoDiagnosticGenerator TDG,
4971 TypoRecoveryCallback TRC) {
4972 assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer");
4973 auto TE = new (Context) TypoExpr(Context.DependentTy);
4974 auto &State = DelayedTypos[TE];
4975 State.Consumer = std::move(TCC);
4976 State.DiagHandler = std::move(TDG);
4977 State.RecoveryHandler = std::move(TRC);
4981 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const {
4982 auto Entry = DelayedTypos.find(TE);
4983 assert(Entry != DelayedTypos.end() &&
4984 "Failed to get the state for a TypoExpr!");
4985 return Entry->second;
4988 void Sema::clearDelayedTypo(TypoExpr *TE) {
4989 DelayedTypos.erase(TE);