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/AST/ASTContext.h"
16 #include "clang/AST/CXXInheritance.h"
17 #include "clang/AST/Decl.h"
18 #include "clang/AST/DeclCXX.h"
19 #include "clang/AST/DeclLookups.h"
20 #include "clang/AST/DeclObjC.h"
21 #include "clang/AST/DeclTemplate.h"
22 #include "clang/AST/Expr.h"
23 #include "clang/AST/ExprCXX.h"
24 #include "clang/Basic/Builtins.h"
25 #include "clang/Basic/LangOptions.h"
26 #include "clang/Lex/HeaderSearch.h"
27 #include "clang/Lex/ModuleLoader.h"
28 #include "clang/Lex/Preprocessor.h"
29 #include "clang/Sema/DeclSpec.h"
30 #include "clang/Sema/Lookup.h"
31 #include "clang/Sema/Overload.h"
32 #include "clang/Sema/Scope.h"
33 #include "clang/Sema/ScopeInfo.h"
34 #include "clang/Sema/Sema.h"
35 #include "clang/Sema/SemaInternal.h"
36 #include "clang/Sema/TemplateDeduction.h"
37 #include "clang/Sema/TypoCorrection.h"
38 #include "llvm/ADT/STLExtras.h"
39 #include "llvm/ADT/SmallPtrSet.h"
40 #include "llvm/ADT/TinyPtrVector.h"
41 #include "llvm/ADT/edit_distance.h"
42 #include "llvm/Support/ErrorHandling.h"
50 using namespace clang;
54 class UnqualUsingEntry {
55 const DeclContext *Nominated;
56 const DeclContext *CommonAncestor;
59 UnqualUsingEntry(const DeclContext *Nominated,
60 const DeclContext *CommonAncestor)
61 : Nominated(Nominated), CommonAncestor(CommonAncestor) {
64 const DeclContext *getCommonAncestor() const {
65 return CommonAncestor;
68 const DeclContext *getNominatedNamespace() const {
72 // Sort by the pointer value of the common ancestor.
74 bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) {
75 return L.getCommonAncestor() < R.getCommonAncestor();
78 bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) {
79 return E.getCommonAncestor() < DC;
82 bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) {
83 return DC < E.getCommonAncestor();
88 /// A collection of using directives, as used by C++ unqualified
90 class UnqualUsingDirectiveSet {
93 typedef SmallVector<UnqualUsingEntry, 8> ListTy;
96 llvm::SmallPtrSet<DeclContext*, 8> visited;
99 UnqualUsingDirectiveSet(Sema &SemaRef) : SemaRef(SemaRef) {}
101 void visitScopeChain(Scope *S, Scope *InnermostFileScope) {
102 // C++ [namespace.udir]p1:
103 // During unqualified name lookup, the names appear as if they
104 // were declared in the nearest enclosing namespace which contains
105 // both the using-directive and the nominated namespace.
106 DeclContext *InnermostFileDC = InnermostFileScope->getEntity();
107 assert(InnermostFileDC && InnermostFileDC->isFileContext());
109 for (; S; S = S->getParent()) {
110 // C++ [namespace.udir]p1:
111 // A using-directive shall not appear in class scope, but may
112 // appear in namespace scope or in block scope.
113 DeclContext *Ctx = S->getEntity();
114 if (Ctx && Ctx->isFileContext()) {
116 } else if (!Ctx || Ctx->isFunctionOrMethod()) {
117 for (auto *I : S->using_directives())
118 if (SemaRef.isVisible(I))
119 visit(I, InnermostFileDC);
124 // Visits a context and collect all of its using directives
125 // recursively. Treats all using directives as if they were
126 // declared in the context.
128 // A given context is only every visited once, so it is important
129 // that contexts be visited from the inside out in order to get
130 // the effective DCs right.
131 void visit(DeclContext *DC, DeclContext *EffectiveDC) {
132 if (!visited.insert(DC).second)
135 addUsingDirectives(DC, EffectiveDC);
138 // Visits a using directive and collects all of its using
139 // directives recursively. Treats all using directives as if they
140 // were declared in the effective DC.
141 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
142 DeclContext *NS = UD->getNominatedNamespace();
143 if (!visited.insert(NS).second)
146 addUsingDirective(UD, EffectiveDC);
147 addUsingDirectives(NS, EffectiveDC);
150 // Adds all the using directives in a context (and those nominated
151 // by its using directives, transitively) as if they appeared in
152 // the given effective context.
153 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) {
154 SmallVector<DeclContext*, 4> queue;
156 for (auto UD : DC->using_directives()) {
157 DeclContext *NS = UD->getNominatedNamespace();
158 if (SemaRef.isVisible(UD) && visited.insert(NS).second) {
159 addUsingDirective(UD, EffectiveDC);
167 DC = queue.pop_back_val();
171 // Add a using directive as if it had been declared in the given
172 // context. This helps implement C++ [namespace.udir]p3:
173 // The using-directive is transitive: if a scope contains a
174 // using-directive that nominates a second namespace that itself
175 // contains using-directives, the effect is as if the
176 // using-directives from the second namespace also appeared in
178 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
179 // Find the common ancestor between the effective context and
180 // the nominated namespace.
181 DeclContext *Common = UD->getNominatedNamespace();
182 while (!Common->Encloses(EffectiveDC))
183 Common = Common->getParent();
184 Common = Common->getPrimaryContext();
186 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common));
190 std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator());
193 typedef ListTy::const_iterator const_iterator;
195 const_iterator begin() const { return list.begin(); }
196 const_iterator end() const { return list.end(); }
198 llvm::iterator_range<const_iterator>
199 getNamespacesFor(DeclContext *DC) const {
200 return llvm::make_range(std::equal_range(begin(), end(),
201 DC->getPrimaryContext(),
202 UnqualUsingEntry::Comparator()));
205 } // end anonymous namespace
207 // Retrieve the set of identifier namespaces that correspond to a
208 // specific kind of name lookup.
209 static inline unsigned getIDNS(Sema::LookupNameKind NameKind,
211 bool Redeclaration) {
214 case Sema::LookupObjCImplicitSelfParam:
215 case Sema::LookupOrdinaryName:
216 case Sema::LookupRedeclarationWithLinkage:
217 case Sema::LookupLocalFriendName:
218 IDNS = Decl::IDNS_Ordinary;
220 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace;
222 IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend;
225 IDNS |= Decl::IDNS_LocalExtern;
228 case Sema::LookupOperatorName:
229 // Operator lookup is its own crazy thing; it is not the same
230 // as (e.g.) looking up an operator name for redeclaration.
231 assert(!Redeclaration && "cannot do redeclaration operator lookup");
232 IDNS = Decl::IDNS_NonMemberOperator;
235 case Sema::LookupTagName:
237 IDNS = Decl::IDNS_Type;
239 // When looking for a redeclaration of a tag name, we add:
240 // 1) TagFriend to find undeclared friend decls
241 // 2) Namespace because they can't "overload" with tag decls.
242 // 3) Tag because it includes class templates, which can't
243 // "overload" with tag decls.
245 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace;
247 IDNS = Decl::IDNS_Tag;
251 case Sema::LookupLabel:
252 IDNS = Decl::IDNS_Label;
255 case Sema::LookupMemberName:
256 IDNS = Decl::IDNS_Member;
258 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary;
261 case Sema::LookupNestedNameSpecifierName:
262 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace;
265 case Sema::LookupNamespaceName:
266 IDNS = Decl::IDNS_Namespace;
269 case Sema::LookupUsingDeclName:
270 assert(Redeclaration && "should only be used for redecl lookup");
271 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member |
272 Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend |
273 Decl::IDNS_LocalExtern;
276 case Sema::LookupObjCProtocolName:
277 IDNS = Decl::IDNS_ObjCProtocol;
280 case Sema::LookupOMPReductionName:
281 IDNS = Decl::IDNS_OMPReduction;
284 case Sema::LookupAnyName:
285 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member
286 | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol
293 void LookupResult::configure() {
294 IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus,
295 isForRedeclaration());
297 // If we're looking for one of the allocation or deallocation
298 // operators, make sure that the implicitly-declared new and delete
299 // operators can be found.
300 switch (NameInfo.getName().getCXXOverloadedOperator()) {
304 case OO_Array_Delete:
305 getSema().DeclareGlobalNewDelete();
312 // Compiler builtins are always visible, regardless of where they end
313 // up being declared.
314 if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) {
315 if (unsigned BuiltinID = Id->getBuiltinID()) {
316 if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
322 bool LookupResult::sanity() const {
323 // This function is never called by NDEBUG builds.
324 assert(ResultKind != NotFound || Decls.size() == 0);
325 assert(ResultKind != Found || Decls.size() == 1);
326 assert(ResultKind != FoundOverloaded || Decls.size() > 1 ||
327 (Decls.size() == 1 &&
328 isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl())));
329 assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved());
330 assert(ResultKind != Ambiguous || Decls.size() > 1 ||
331 (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects ||
332 Ambiguity == AmbiguousBaseSubobjectTypes)));
333 assert((Paths != nullptr) == (ResultKind == Ambiguous &&
334 (Ambiguity == AmbiguousBaseSubobjectTypes ||
335 Ambiguity == AmbiguousBaseSubobjects)));
339 // Necessary because CXXBasePaths is not complete in Sema.h
340 void LookupResult::deletePaths(CXXBasePaths *Paths) {
344 /// Get a representative context for a declaration such that two declarations
345 /// will have the same context if they were found within the same scope.
346 static DeclContext *getContextForScopeMatching(Decl *D) {
347 // For function-local declarations, use that function as the context. This
348 // doesn't account for scopes within the function; the caller must deal with
350 DeclContext *DC = D->getLexicalDeclContext();
351 if (DC->isFunctionOrMethod())
354 // Otherwise, look at the semantic context of the declaration. The
355 // declaration must have been found there.
356 return D->getDeclContext()->getRedeclContext();
359 /// \brief Determine whether \p D is a better lookup result than \p Existing,
360 /// given that they declare the same entity.
361 static bool isPreferredLookupResult(Sema &S, Sema::LookupNameKind Kind,
362 NamedDecl *D, NamedDecl *Existing) {
363 // When looking up redeclarations of a using declaration, prefer a using
364 // shadow declaration over any other declaration of the same entity.
365 if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(D) &&
366 !isa<UsingShadowDecl>(Existing))
369 auto *DUnderlying = D->getUnderlyingDecl();
370 auto *EUnderlying = Existing->getUnderlyingDecl();
372 // If they have different underlying declarations, prefer a typedef over the
373 // original type (this happens when two type declarations denote the same
374 // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef
375 // might carry additional semantic information, such as an alignment override.
376 // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag
377 // declaration over a typedef.
378 if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) {
379 assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying));
380 bool HaveTag = isa<TagDecl>(EUnderlying);
381 bool WantTag = Kind == Sema::LookupTagName;
382 return HaveTag != WantTag;
385 // Pick the function with more default arguments.
386 // FIXME: In the presence of ambiguous default arguments, we should keep both,
387 // so we can diagnose the ambiguity if the default argument is needed.
388 // See C++ [over.match.best]p3.
389 if (auto *DFD = dyn_cast<FunctionDecl>(DUnderlying)) {
390 auto *EFD = cast<FunctionDecl>(EUnderlying);
391 unsigned DMin = DFD->getMinRequiredArguments();
392 unsigned EMin = EFD->getMinRequiredArguments();
393 // If D has more default arguments, it is preferred.
396 // FIXME: When we track visibility for default function arguments, check
397 // that we pick the declaration with more visible default arguments.
400 // Pick the template with more default template arguments.
401 if (auto *DTD = dyn_cast<TemplateDecl>(DUnderlying)) {
402 auto *ETD = cast<TemplateDecl>(EUnderlying);
403 unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments();
404 unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments();
405 // If D has more default arguments, it is preferred. Note that default
406 // arguments (and their visibility) is monotonically increasing across the
407 // redeclaration chain, so this is a quick proxy for "is more recent".
410 // If D has more *visible* default arguments, it is preferred. Note, an
411 // earlier default argument being visible does not imply that a later
412 // default argument is visible, so we can't just check the first one.
413 for (unsigned I = DMin, N = DTD->getTemplateParameters()->size();
415 if (!S.hasVisibleDefaultArgument(
416 ETD->getTemplateParameters()->getParam(I)) &&
417 S.hasVisibleDefaultArgument(
418 DTD->getTemplateParameters()->getParam(I)))
423 // VarDecl can have incomplete array types, prefer the one with more complete
425 if (VarDecl *DVD = dyn_cast<VarDecl>(DUnderlying)) {
426 VarDecl *EVD = cast<VarDecl>(EUnderlying);
427 if (EVD->getType()->isIncompleteType() &&
428 !DVD->getType()->isIncompleteType()) {
429 // Prefer the decl with a more complete type if visible.
430 return S.isVisible(DVD);
432 return false; // Avoid picking up a newer decl, just because it was newer.
435 // For most kinds of declaration, it doesn't really matter which one we pick.
436 if (!isa<FunctionDecl>(DUnderlying) && !isa<VarDecl>(DUnderlying)) {
437 // If the existing declaration is hidden, prefer the new one. Otherwise,
438 // keep what we've got.
439 return !S.isVisible(Existing);
442 // Pick the newer declaration; it might have a more precise type.
443 for (Decl *Prev = DUnderlying->getPreviousDecl(); Prev;
444 Prev = Prev->getPreviousDecl())
445 if (Prev == EUnderlying)
450 /// Determine whether \p D can hide a tag declaration.
451 static bool canHideTag(NamedDecl *D) {
452 // C++ [basic.scope.declarative]p4:
453 // Given a set of declarations in a single declarative region [...]
454 // exactly one declaration shall declare a class name or enumeration name
455 // that is not a typedef name and the other declarations shall all refer to
456 // the same variable, non-static data member, or enumerator, or all refer
457 // to functions and function templates; in this case the class name or
458 // enumeration name is hidden.
459 // C++ [basic.scope.hiding]p2:
460 // A class name or enumeration name can be hidden by the name of a
461 // variable, data member, function, or enumerator declared in the same
463 // An UnresolvedUsingValueDecl always instantiates to one of these.
464 D = D->getUnderlyingDecl();
465 return isa<VarDecl>(D) || isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D) ||
466 isa<FunctionTemplateDecl>(D) || isa<FieldDecl>(D) ||
467 isa<UnresolvedUsingValueDecl>(D);
470 /// Resolves the result kind of this lookup.
471 void LookupResult::resolveKind() {
472 unsigned N = Decls.size();
474 // Fast case: no possible ambiguity.
476 assert(ResultKind == NotFound ||
477 ResultKind == NotFoundInCurrentInstantiation);
481 // If there's a single decl, we need to examine it to decide what
482 // kind of lookup this is.
484 NamedDecl *D = (*Decls.begin())->getUnderlyingDecl();
485 if (isa<FunctionTemplateDecl>(D))
486 ResultKind = FoundOverloaded;
487 else if (isa<UnresolvedUsingValueDecl>(D))
488 ResultKind = FoundUnresolvedValue;
492 // Don't do any extra resolution if we've already resolved as ambiguous.
493 if (ResultKind == Ambiguous) return;
495 llvm::SmallDenseMap<NamedDecl*, unsigned, 16> Unique;
496 llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes;
498 bool Ambiguous = false;
499 bool HasTag = false, HasFunction = false;
500 bool HasFunctionTemplate = false, HasUnresolved = false;
501 NamedDecl *HasNonFunction = nullptr;
503 llvm::SmallVector<NamedDecl*, 4> EquivalentNonFunctions;
505 unsigned UniqueTagIndex = 0;
509 NamedDecl *D = Decls[I]->getUnderlyingDecl();
510 D = cast<NamedDecl>(D->getCanonicalDecl());
512 // Ignore an invalid declaration unless it's the only one left.
513 if (D->isInvalidDecl() && !(I == 0 && N == 1)) {
514 Decls[I] = Decls[--N];
518 llvm::Optional<unsigned> ExistingI;
520 // Redeclarations of types via typedef can occur both within a scope
521 // and, through using declarations and directives, across scopes. There is
522 // no ambiguity if they all refer to the same type, so unique based on the
524 if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) {
525 QualType T = getSema().Context.getTypeDeclType(TD);
526 auto UniqueResult = UniqueTypes.insert(
527 std::make_pair(getSema().Context.getCanonicalType(T), I));
528 if (!UniqueResult.second) {
529 // The type is not unique.
530 ExistingI = UniqueResult.first->second;
534 // For non-type declarations, check for a prior lookup result naming this
535 // canonical declaration.
537 auto UniqueResult = Unique.insert(std::make_pair(D, I));
538 if (!UniqueResult.second) {
539 // We've seen this entity before.
540 ExistingI = UniqueResult.first->second;
545 // This is not a unique lookup result. Pick one of the results and
546 // discard the other.
547 if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I],
549 Decls[*ExistingI] = Decls[I];
550 Decls[I] = Decls[--N];
554 // Otherwise, do some decl type analysis and then continue.
556 if (isa<UnresolvedUsingValueDecl>(D)) {
557 HasUnresolved = true;
558 } else if (isa<TagDecl>(D)) {
563 } else if (isa<FunctionTemplateDecl>(D)) {
565 HasFunctionTemplate = true;
566 } else if (isa<FunctionDecl>(D)) {
569 if (HasNonFunction) {
570 // If we're about to create an ambiguity between two declarations that
571 // are equivalent, but one is an internal linkage declaration from one
572 // module and the other is an internal linkage declaration from another
573 // module, just skip it.
574 if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction,
576 EquivalentNonFunctions.push_back(D);
577 Decls[I] = Decls[--N];
588 // C++ [basic.scope.hiding]p2:
589 // A class name or enumeration name can be hidden by the name of
590 // an object, function, or enumerator declared in the same
591 // scope. If a class or enumeration name and an object, function,
592 // or enumerator are declared in the same scope (in any order)
593 // with the same name, the class or enumeration name is hidden
594 // wherever the object, function, or enumerator name is visible.
595 // But it's still an error if there are distinct tag types found,
596 // even if they're not visible. (ref?)
597 if (N > 1 && HideTags && HasTag && !Ambiguous &&
598 (HasFunction || HasNonFunction || HasUnresolved)) {
599 NamedDecl *OtherDecl = Decls[UniqueTagIndex ? 0 : N - 1];
600 if (isa<TagDecl>(Decls[UniqueTagIndex]->getUnderlyingDecl()) &&
601 getContextForScopeMatching(Decls[UniqueTagIndex])->Equals(
602 getContextForScopeMatching(OtherDecl)) &&
603 canHideTag(OtherDecl))
604 Decls[UniqueTagIndex] = Decls[--N];
609 // FIXME: This diagnostic should really be delayed until we're done with
610 // the lookup result, in case the ambiguity is resolved by the caller.
611 if (!EquivalentNonFunctions.empty() && !Ambiguous)
612 getSema().diagnoseEquivalentInternalLinkageDeclarations(
613 getNameLoc(), HasNonFunction, EquivalentNonFunctions);
617 if (HasNonFunction && (HasFunction || HasUnresolved))
621 setAmbiguous(LookupResult::AmbiguousReference);
622 else if (HasUnresolved)
623 ResultKind = LookupResult::FoundUnresolvedValue;
624 else if (N > 1 || HasFunctionTemplate)
625 ResultKind = LookupResult::FoundOverloaded;
627 ResultKind = LookupResult::Found;
630 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
631 CXXBasePaths::const_paths_iterator I, E;
632 for (I = P.begin(), E = P.end(); I != E; ++I)
633 for (DeclContext::lookup_iterator DI = I->Decls.begin(),
634 DE = I->Decls.end(); DI != DE; ++DI)
638 void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) {
639 Paths = new CXXBasePaths;
641 addDeclsFromBasePaths(*Paths);
643 setAmbiguous(AmbiguousBaseSubobjects);
646 void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) {
647 Paths = new CXXBasePaths;
649 addDeclsFromBasePaths(*Paths);
651 setAmbiguous(AmbiguousBaseSubobjectTypes);
654 void LookupResult::print(raw_ostream &Out) {
655 Out << Decls.size() << " result(s)";
656 if (isAmbiguous()) Out << ", ambiguous";
657 if (Paths) Out << ", base paths present";
659 for (iterator I = begin(), E = end(); I != E; ++I) {
665 LLVM_DUMP_METHOD void LookupResult::dump() {
666 llvm::errs() << "lookup results for " << getLookupName().getAsString()
668 for (NamedDecl *D : *this)
672 /// \brief Lookup a builtin function, when name lookup would otherwise
674 static bool LookupBuiltin(Sema &S, LookupResult &R) {
675 Sema::LookupNameKind NameKind = R.getLookupKind();
677 // If we didn't find a use of this identifier, and if the identifier
678 // corresponds to a compiler builtin, create the decl object for the builtin
679 // now, injecting it into translation unit scope, and return it.
680 if (NameKind == Sema::LookupOrdinaryName ||
681 NameKind == Sema::LookupRedeclarationWithLinkage) {
682 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo();
684 if (S.getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName) {
685 if (II == S.getASTContext().getMakeIntegerSeqName()) {
686 R.addDecl(S.getASTContext().getMakeIntegerSeqDecl());
688 } else if (II == S.getASTContext().getTypePackElementName()) {
689 R.addDecl(S.getASTContext().getTypePackElementDecl());
694 // If this is a builtin on this (or all) targets, create the decl.
695 if (unsigned BuiltinID = II->getBuiltinID()) {
696 // In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined
697 // library functions like 'malloc'. Instead, we'll just error.
698 if ((S.getLangOpts().CPlusPlus || S.getLangOpts().OpenCL) &&
699 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
702 if (NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II,
703 BuiltinID, S.TUScope,
704 R.isForRedeclaration(),
716 /// \brief Determine whether we can declare a special member function within
717 /// the class at this point.
718 static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) {
719 // We need to have a definition for the class.
720 if (!Class->getDefinition() || Class->isDependentContext())
723 // We can't be in the middle of defining the class.
724 return !Class->isBeingDefined();
727 void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) {
728 if (!CanDeclareSpecialMemberFunction(Class))
731 // If the default constructor has not yet been declared, do so now.
732 if (Class->needsImplicitDefaultConstructor())
733 DeclareImplicitDefaultConstructor(Class);
735 // If the copy constructor has not yet been declared, do so now.
736 if (Class->needsImplicitCopyConstructor())
737 DeclareImplicitCopyConstructor(Class);
739 // If the copy assignment operator has not yet been declared, do so now.
740 if (Class->needsImplicitCopyAssignment())
741 DeclareImplicitCopyAssignment(Class);
743 if (getLangOpts().CPlusPlus11) {
744 // If the move constructor has not yet been declared, do so now.
745 if (Class->needsImplicitMoveConstructor())
746 DeclareImplicitMoveConstructor(Class);
748 // If the move assignment operator has not yet been declared, do so now.
749 if (Class->needsImplicitMoveAssignment())
750 DeclareImplicitMoveAssignment(Class);
753 // If the destructor has not yet been declared, do so now.
754 if (Class->needsImplicitDestructor())
755 DeclareImplicitDestructor(Class);
758 /// \brief Determine whether this is the name of an implicitly-declared
759 /// special member function.
760 static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) {
761 switch (Name.getNameKind()) {
762 case DeclarationName::CXXConstructorName:
763 case DeclarationName::CXXDestructorName:
766 case DeclarationName::CXXOperatorName:
767 return Name.getCXXOverloadedOperator() == OO_Equal;
776 /// \brief If there are any implicit member functions with the given name
777 /// that need to be declared in the given declaration context, do so.
778 static void DeclareImplicitMemberFunctionsWithName(Sema &S,
779 DeclarationName Name,
781 const DeclContext *DC) {
785 switch (Name.getNameKind()) {
786 case DeclarationName::CXXConstructorName:
787 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
788 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
789 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
790 if (Record->needsImplicitDefaultConstructor())
791 S.DeclareImplicitDefaultConstructor(Class);
792 if (Record->needsImplicitCopyConstructor())
793 S.DeclareImplicitCopyConstructor(Class);
794 if (S.getLangOpts().CPlusPlus11 &&
795 Record->needsImplicitMoveConstructor())
796 S.DeclareImplicitMoveConstructor(Class);
800 case DeclarationName::CXXDestructorName:
801 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
802 if (Record->getDefinition() && Record->needsImplicitDestructor() &&
803 CanDeclareSpecialMemberFunction(Record))
804 S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record));
807 case DeclarationName::CXXOperatorName:
808 if (Name.getCXXOverloadedOperator() != OO_Equal)
811 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) {
812 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
813 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
814 if (Record->needsImplicitCopyAssignment())
815 S.DeclareImplicitCopyAssignment(Class);
816 if (S.getLangOpts().CPlusPlus11 &&
817 Record->needsImplicitMoveAssignment())
818 S.DeclareImplicitMoveAssignment(Class);
823 case DeclarationName::CXXDeductionGuideName:
824 S.DeclareImplicitDeductionGuides(Name.getCXXDeductionGuideTemplate(), Loc);
832 // Adds all qualifying matches for a name within a decl context to the
833 // given lookup result. Returns true if any matches were found.
834 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
837 // Lazily declare C++ special member functions.
838 if (S.getLangOpts().CPlusPlus)
839 DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), R.getNameLoc(),
842 // Perform lookup into this declaration context.
843 DeclContext::lookup_result DR = DC->lookup(R.getLookupName());
844 for (NamedDecl *D : DR) {
845 if ((D = R.getAcceptableDecl(D))) {
851 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R))
854 if (R.getLookupName().getNameKind()
855 != DeclarationName::CXXConversionFunctionName ||
856 R.getLookupName().getCXXNameType()->isDependentType() ||
857 !isa<CXXRecordDecl>(DC))
861 // A specialization of a conversion function template is not found by
862 // name lookup. Instead, any conversion function templates visible in the
863 // context of the use are considered. [...]
864 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
865 if (!Record->isCompleteDefinition())
868 // For conversion operators, 'operator auto' should only match
869 // 'operator auto'. Since 'auto' is not a type, it shouldn't be considered
870 // as a candidate for template substitution.
871 auto *ContainedDeducedType =
872 R.getLookupName().getCXXNameType()->getContainedDeducedType();
873 if (R.getLookupName().getNameKind() ==
874 DeclarationName::CXXConversionFunctionName &&
875 ContainedDeducedType && ContainedDeducedType->isUndeducedType())
878 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(),
879 UEnd = Record->conversion_end(); U != UEnd; ++U) {
880 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
884 // When we're performing lookup for the purposes of redeclaration, just
885 // add the conversion function template. When we deduce template
886 // arguments for specializations, we'll end up unifying the return
887 // type of the new declaration with the type of the function template.
888 if (R.isForRedeclaration()) {
889 R.addDecl(ConvTemplate);
895 // [...] For each such operator, if argument deduction succeeds
896 // (14.9.2.3), the resulting specialization is used as if found by
899 // When referencing a conversion function for any purpose other than
900 // a redeclaration (such that we'll be building an expression with the
901 // result), perform template argument deduction and place the
902 // specialization into the result set. We do this to avoid forcing all
903 // callers to perform special deduction for conversion functions.
904 TemplateDeductionInfo Info(R.getNameLoc());
905 FunctionDecl *Specialization = nullptr;
907 const FunctionProtoType *ConvProto
908 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
909 assert(ConvProto && "Nonsensical conversion function template type");
911 // Compute the type of the function that we would expect the conversion
912 // function to have, if it were to match the name given.
913 // FIXME: Calling convention!
914 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo();
915 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C);
916 EPI.ExceptionSpec = EST_None;
917 QualType ExpectedType
918 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(),
921 // Perform template argument deduction against the type that we would
922 // expect the function to have.
923 if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType,
924 Specialization, Info)
925 == Sema::TDK_Success) {
926 R.addDecl(Specialization);
934 // Performs C++ unqualified lookup into the given file context.
936 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context,
937 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
939 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
941 // Perform direct name lookup into the LookupCtx.
942 bool Found = LookupDirect(S, R, NS);
944 // Perform direct name lookup into the namespaces nominated by the
945 // using directives whose common ancestor is this namespace.
946 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS))
947 if (LookupDirect(S, R, UUE.getNominatedNamespace()))
955 static bool isNamespaceOrTranslationUnitScope(Scope *S) {
956 if (DeclContext *Ctx = S->getEntity())
957 return Ctx->isFileContext();
961 // Find the next outer declaration context from this scope. This
962 // routine actually returns the semantic outer context, which may
963 // differ from the lexical context (encoded directly in the Scope
964 // stack) when we are parsing a member of a class template. In this
965 // case, the second element of the pair will be true, to indicate that
966 // name lookup should continue searching in this semantic context when
967 // it leaves the current template parameter scope.
968 static std::pair<DeclContext *, bool> findOuterContext(Scope *S) {
969 DeclContext *DC = S->getEntity();
970 DeclContext *Lexical = nullptr;
971 for (Scope *OuterS = S->getParent(); OuterS;
972 OuterS = OuterS->getParent()) {
973 if (OuterS->getEntity()) {
974 Lexical = OuterS->getEntity();
979 // C++ [temp.local]p8:
980 // In the definition of a member of a class template that appears
981 // outside of the namespace containing the class template
982 // definition, the name of a template-parameter hides the name of
983 // a member of this namespace.
990 // template<class T> class B {
995 // template<class C> void N::B<C>::f(C) {
996 // C b; // C is the template parameter, not N::C
999 // In this example, the lexical context we return is the
1000 // TranslationUnit, while the semantic context is the namespace N.
1001 if (!Lexical || !DC || !S->getParent() ||
1002 !S->getParent()->isTemplateParamScope())
1003 return std::make_pair(Lexical, false);
1005 // Find the outermost template parameter scope.
1006 // For the example, this is the scope for the template parameters of
1007 // template<class C>.
1008 Scope *OutermostTemplateScope = S->getParent();
1009 while (OutermostTemplateScope->getParent() &&
1010 OutermostTemplateScope->getParent()->isTemplateParamScope())
1011 OutermostTemplateScope = OutermostTemplateScope->getParent();
1013 // Find the namespace context in which the original scope occurs. In
1014 // the example, this is namespace N.
1015 DeclContext *Semantic = DC;
1016 while (!Semantic->isFileContext())
1017 Semantic = Semantic->getParent();
1019 // Find the declaration context just outside of the template
1020 // parameter scope. This is the context in which the template is
1021 // being lexically declaration (a namespace context). In the
1022 // example, this is the global scope.
1023 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) &&
1024 Lexical->Encloses(Semantic))
1025 return std::make_pair(Semantic, true);
1027 return std::make_pair(Lexical, false);
1031 /// An RAII object to specify that we want to find block scope extern
1033 struct FindLocalExternScope {
1034 FindLocalExternScope(LookupResult &R)
1035 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
1036 Decl::IDNS_LocalExtern) {
1037 R.setFindLocalExtern(R.getIdentifierNamespace() &
1038 (Decl::IDNS_Ordinary | Decl::IDNS_NonMemberOperator));
1041 R.setFindLocalExtern(OldFindLocalExtern);
1043 ~FindLocalExternScope() {
1047 bool OldFindLocalExtern;
1049 } // end anonymous namespace
1051 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
1052 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
1054 DeclarationName Name = R.getLookupName();
1055 Sema::LookupNameKind NameKind = R.getLookupKind();
1057 // If this is the name of an implicitly-declared special member function,
1058 // go through the scope stack to implicitly declare
1059 if (isImplicitlyDeclaredMemberFunctionName(Name)) {
1060 for (Scope *PreS = S; PreS; PreS = PreS->getParent())
1061 if (DeclContext *DC = PreS->getEntity())
1062 DeclareImplicitMemberFunctionsWithName(*this, Name, R.getNameLoc(), DC);
1065 // Implicitly declare member functions with the name we're looking for, if in
1066 // fact we are in a scope where it matters.
1069 IdentifierResolver::iterator
1070 I = IdResolver.begin(Name),
1071 IEnd = IdResolver.end();
1073 // First we lookup local scope.
1074 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
1075 // ...During unqualified name lookup (3.4.1), the names appear as if
1076 // they were declared in the nearest enclosing namespace which contains
1077 // both the using-directive and the nominated namespace.
1078 // [Note: in this context, "contains" means "contains directly or
1082 // namespace A { int i; }
1086 // using namespace A;
1087 // ++i; // finds local 'i', A::i appears at global scope
1091 UnqualUsingDirectiveSet UDirs(*this);
1092 bool VisitedUsingDirectives = false;
1093 bool LeftStartingScope = false;
1094 DeclContext *OutsideOfTemplateParamDC = nullptr;
1096 // When performing a scope lookup, we want to find local extern decls.
1097 FindLocalExternScope FindLocals(R);
1099 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
1100 DeclContext *Ctx = S->getEntity();
1101 bool SearchNamespaceScope = true;
1102 // Check whether the IdResolver has anything in this scope.
1103 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1104 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1105 if (NameKind == LookupRedeclarationWithLinkage &&
1106 !(*I)->isTemplateParameter()) {
1107 // If it's a template parameter, we still find it, so we can diagnose
1108 // the invalid redeclaration.
1110 // Determine whether this (or a previous) declaration is
1112 if (!LeftStartingScope && !Initial->isDeclScope(*I))
1113 LeftStartingScope = true;
1115 // If we found something outside of our starting scope that
1116 // does not have linkage, skip it.
1117 if (LeftStartingScope && !((*I)->hasLinkage())) {
1122 // We found something in this scope, we should not look at the
1124 SearchNamespaceScope = false;
1129 if (!SearchNamespaceScope) {
1131 if (S->isClassScope())
1132 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx))
1133 R.setNamingClass(Record);
1137 if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
1138 // C++11 [class.friend]p11:
1139 // If a friend declaration appears in a local class and the name
1140 // specified is an unqualified name, a prior declaration is
1141 // looked up without considering scopes that are outside the
1142 // innermost enclosing non-class scope.
1146 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1147 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1148 // We've just searched the last template parameter scope and
1149 // found nothing, so look into the contexts between the
1150 // lexical and semantic declaration contexts returned by
1151 // findOuterContext(). This implements the name lookup behavior
1152 // of C++ [temp.local]p8.
1153 Ctx = OutsideOfTemplateParamDC;
1154 OutsideOfTemplateParamDC = nullptr;
1158 DeclContext *OuterCtx;
1159 bool SearchAfterTemplateScope;
1160 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1161 if (SearchAfterTemplateScope)
1162 OutsideOfTemplateParamDC = OuterCtx;
1164 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1165 // We do not directly look into transparent contexts, since
1166 // those entities will be found in the nearest enclosing
1167 // non-transparent context.
1168 if (Ctx->isTransparentContext())
1171 // We do not look directly into function or method contexts,
1172 // since all of the local variables and parameters of the
1173 // function/method are present within the Scope.
1174 if (Ctx->isFunctionOrMethod()) {
1175 // If we have an Objective-C instance method, look for ivars
1176 // in the corresponding interface.
1177 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
1178 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
1179 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
1180 ObjCInterfaceDecl *ClassDeclared;
1181 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
1182 Name.getAsIdentifierInfo(),
1184 if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
1196 // If this is a file context, we need to perform unqualified name
1197 // lookup considering using directives.
1198 if (Ctx->isFileContext()) {
1199 // If we haven't handled using directives yet, do so now.
1200 if (!VisitedUsingDirectives) {
1201 // Add using directives from this context up to the top level.
1202 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
1203 if (UCtx->isTransparentContext())
1206 UDirs.visit(UCtx, UCtx);
1209 // Find the innermost file scope, so we can add using directives
1210 // from local scopes.
1211 Scope *InnermostFileScope = S;
1212 while (InnermostFileScope &&
1213 !isNamespaceOrTranslationUnitScope(InnermostFileScope))
1214 InnermostFileScope = InnermostFileScope->getParent();
1215 UDirs.visitScopeChain(Initial, InnermostFileScope);
1219 VisitedUsingDirectives = true;
1222 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
1230 // Perform qualified name lookup into this context.
1231 // FIXME: In some cases, we know that every name that could be found by
1232 // this qualified name lookup will also be on the identifier chain. For
1233 // example, inside a class without any base classes, we never need to
1234 // perform qualified lookup because all of the members are on top of the
1235 // identifier chain.
1236 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
1242 // Stop if we ran out of scopes.
1243 // FIXME: This really, really shouldn't be happening.
1244 if (!S) return false;
1246 // If we are looking for members, no need to look into global/namespace scope.
1247 if (NameKind == LookupMemberName)
1250 // Collect UsingDirectiveDecls in all scopes, and recursively all
1251 // nominated namespaces by those using-directives.
1253 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
1254 // don't build it for each lookup!
1255 if (!VisitedUsingDirectives) {
1256 UDirs.visitScopeChain(Initial, S);
1260 // If we're not performing redeclaration lookup, do not look for local
1261 // extern declarations outside of a function scope.
1262 if (!R.isForRedeclaration())
1263 FindLocals.restore();
1265 // Lookup namespace scope, and global scope.
1266 // Unqualified name lookup in C++ requires looking into scopes
1267 // that aren't strictly lexical, and therefore we walk through the
1268 // context as well as walking through the scopes.
1269 for (; S; S = S->getParent()) {
1270 // Check whether the IdResolver has anything in this scope.
1272 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1273 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1274 // We found something. Look for anything else in our scope
1275 // with this same name and in an acceptable identifier
1276 // namespace, so that we can construct an overload set if we
1283 if (Found && S->isTemplateParamScope()) {
1288 DeclContext *Ctx = S->getEntity();
1289 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1290 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1291 // We've just searched the last template parameter scope and
1292 // found nothing, so look into the contexts between the
1293 // lexical and semantic declaration contexts returned by
1294 // findOuterContext(). This implements the name lookup behavior
1295 // of C++ [temp.local]p8.
1296 Ctx = OutsideOfTemplateParamDC;
1297 OutsideOfTemplateParamDC = nullptr;
1301 DeclContext *OuterCtx;
1302 bool SearchAfterTemplateScope;
1303 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1304 if (SearchAfterTemplateScope)
1305 OutsideOfTemplateParamDC = OuterCtx;
1307 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1308 // We do not directly look into transparent contexts, since
1309 // those entities will be found in the nearest enclosing
1310 // non-transparent context.
1311 if (Ctx->isTransparentContext())
1314 // If we have a context, and it's not a context stashed in the
1315 // template parameter scope for an out-of-line definition, also
1316 // look into that context.
1317 if (!(Found && S->isTemplateParamScope())) {
1318 assert(Ctx->isFileContext() &&
1319 "We should have been looking only at file context here already.");
1321 // Look into context considering using-directives.
1322 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
1331 if (R.isForRedeclaration() && !Ctx->isTransparentContext())
1336 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
1343 void Sema::makeMergedDefinitionVisible(NamedDecl *ND) {
1344 if (auto *M = getCurrentModule())
1345 Context.mergeDefinitionIntoModule(ND, M);
1347 // We're not building a module; just make the definition visible.
1348 ND->setVisibleDespiteOwningModule();
1350 // If ND is a template declaration, make the template parameters
1351 // visible too. They're not (necessarily) within a mergeable DeclContext.
1352 if (auto *TD = dyn_cast<TemplateDecl>(ND))
1353 for (auto *Param : *TD->getTemplateParameters())
1354 makeMergedDefinitionVisible(Param);
1357 /// \brief Find the module in which the given declaration was defined.
1358 static Module *getDefiningModule(Sema &S, Decl *Entity) {
1359 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
1360 // If this function was instantiated from a template, the defining module is
1361 // the module containing the pattern.
1362 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1364 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
1365 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1367 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
1368 if (auto *Pattern = ED->getTemplateInstantiationPattern())
1370 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
1371 if (VarDecl *Pattern = VD->getTemplateInstantiationPattern())
1375 // Walk up to the containing context. That might also have been instantiated
1377 DeclContext *Context = Entity->getLexicalDeclContext();
1378 if (Context->isFileContext())
1379 return S.getOwningModule(Entity);
1380 return getDefiningModule(S, cast<Decl>(Context));
1383 llvm::DenseSet<Module*> &Sema::getLookupModules() {
1384 unsigned N = CodeSynthesisContexts.size();
1385 for (unsigned I = CodeSynthesisContextLookupModules.size();
1387 Module *M = getDefiningModule(*this, CodeSynthesisContexts[I].Entity);
1388 if (M && !LookupModulesCache.insert(M).second)
1390 CodeSynthesisContextLookupModules.push_back(M);
1392 return LookupModulesCache;
1395 bool Sema::hasVisibleMergedDefinition(NamedDecl *Def) {
1396 for (Module *Merged : Context.getModulesWithMergedDefinition(Def))
1397 if (isModuleVisible(Merged))
1402 bool Sema::hasMergedDefinitionInCurrentModule(NamedDecl *Def) {
1403 // FIXME: When not in local visibility mode, we can't tell the difference
1404 // between a declaration being visible because we merged a local copy of
1405 // the same declaration into it, and it being visible because its owning
1406 // module is visible.
1407 if (Def->getModuleOwnershipKind() == Decl::ModuleOwnershipKind::Visible &&
1408 getLangOpts().ModulesLocalVisibility)
1410 for (Module *Merged : Context.getModulesWithMergedDefinition(Def))
1411 if (Merged->getTopLevelModuleName() == getLangOpts().CurrentModule)
1416 template<typename ParmDecl>
1418 hasVisibleDefaultArgument(Sema &S, const ParmDecl *D,
1419 llvm::SmallVectorImpl<Module *> *Modules) {
1420 if (!D->hasDefaultArgument())
1424 auto &DefaultArg = D->getDefaultArgStorage();
1425 if (!DefaultArg.isInherited() && S.isVisible(D))
1428 if (!DefaultArg.isInherited() && Modules) {
1429 auto *NonConstD = const_cast<ParmDecl*>(D);
1430 Modules->push_back(S.getOwningModule(NonConstD));
1431 const auto &Merged = S.Context.getModulesWithMergedDefinition(NonConstD);
1432 Modules->insert(Modules->end(), Merged.begin(), Merged.end());
1435 // If there was a previous default argument, maybe its parameter is visible.
1436 D = DefaultArg.getInheritedFrom();
1441 bool Sema::hasVisibleDefaultArgument(const NamedDecl *D,
1442 llvm::SmallVectorImpl<Module *> *Modules) {
1443 if (auto *P = dyn_cast<TemplateTypeParmDecl>(D))
1444 return ::hasVisibleDefaultArgument(*this, P, Modules);
1445 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D))
1446 return ::hasVisibleDefaultArgument(*this, P, Modules);
1447 return ::hasVisibleDefaultArgument(*this, cast<TemplateTemplateParmDecl>(D),
1451 template<typename Filter>
1452 static bool hasVisibleDeclarationImpl(Sema &S, const NamedDecl *D,
1453 llvm::SmallVectorImpl<Module *> *Modules,
1455 for (auto *Redecl : D->redecls()) {
1456 auto *R = cast<NamedDecl>(Redecl);
1464 Modules->push_back(R->getOwningModule());
1465 const auto &Merged = S.Context.getModulesWithMergedDefinition(R);
1466 Modules->insert(Modules->end(), Merged.begin(), Merged.end());
1473 bool Sema::hasVisibleExplicitSpecialization(
1474 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1475 return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1476 if (auto *RD = dyn_cast<CXXRecordDecl>(D))
1477 return RD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1478 if (auto *FD = dyn_cast<FunctionDecl>(D))
1479 return FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1480 if (auto *VD = dyn_cast<VarDecl>(D))
1481 return VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1482 llvm_unreachable("unknown explicit specialization kind");
1486 bool Sema::hasVisibleMemberSpecialization(
1487 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1488 assert(isa<CXXRecordDecl>(D->getDeclContext()) &&
1489 "not a member specialization");
1490 return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1491 // If the specialization is declared at namespace scope, then it's a member
1492 // specialization declaration. If it's lexically inside the class
1493 // definition then it was instantiated.
1495 // FIXME: This is a hack. There should be a better way to determine this.
1496 // FIXME: What about MS-style explicit specializations declared within a
1497 // class definition?
1498 return D->getLexicalDeclContext()->isFileContext();
1504 /// \brief Determine whether a declaration is visible to name lookup.
1506 /// This routine determines whether the declaration D is visible in the current
1507 /// lookup context, taking into account the current template instantiation
1508 /// stack. During template instantiation, a declaration is visible if it is
1509 /// visible from a module containing any entity on the template instantiation
1510 /// path (by instantiating a template, you allow it to see the declarations that
1511 /// your module can see, including those later on in your module).
1512 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
1513 assert(D->isHidden() && "should not call this: not in slow case");
1515 Module *DeclModule = SemaRef.getOwningModule(D);
1517 // A module-private declaration with no owning module means this is in the
1518 // global module in the C++ Modules TS. This is visible within the same
1519 // translation unit only.
1520 // FIXME: Don't assume that "same translation unit" means the same thing
1521 // as "not from an AST file".
1522 assert(D->isModulePrivate() && "hidden decl has no module");
1523 if (!D->isFromASTFile() || SemaRef.hasMergedDefinitionInCurrentModule(D))
1526 // If the owning module is visible, and the decl is not module private,
1527 // then the decl is visible too. (Module private is ignored within the same
1528 // top-level module.)
1529 if (D->isModulePrivate()
1530 ? DeclModule->getTopLevelModuleName() ==
1531 SemaRef.getLangOpts().CurrentModule ||
1532 SemaRef.hasMergedDefinitionInCurrentModule(D)
1533 : SemaRef.isModuleVisible(DeclModule) ||
1534 SemaRef.hasVisibleMergedDefinition(D))
1538 // Determine whether a decl context is a file context for the purpose of
1539 // visibility. This looks through some (export and linkage spec) transparent
1540 // contexts, but not others (enums).
1541 auto IsEffectivelyFileContext = [](const DeclContext *DC) {
1542 return DC->isFileContext() || isa<LinkageSpecDecl>(DC) ||
1543 isa<ExportDecl>(DC);
1546 // If this declaration is not at namespace scope
1547 // then it is visible if its lexical parent has a visible definition.
1548 DeclContext *DC = D->getLexicalDeclContext();
1549 if (DC && !IsEffectivelyFileContext(DC)) {
1550 // For a parameter, check whether our current template declaration's
1551 // lexical context is visible, not whether there's some other visible
1552 // definition of it, because parameters aren't "within" the definition.
1554 // In C++ we need to check for a visible definition due to ODR merging,
1555 // and in C we must not because each declaration of a function gets its own
1556 // set of declarations for tags in prototype scope.
1557 bool VisibleWithinParent;
1558 if (D->isTemplateParameter() || isa<ParmVarDecl>(D) ||
1559 (isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus))
1560 VisibleWithinParent = isVisible(SemaRef, cast<NamedDecl>(DC));
1561 else if (D->isModulePrivate()) {
1562 // A module-private declaration is only visible if an enclosing lexical
1563 // parent was merged with another definition in the current module.
1564 VisibleWithinParent = false;
1566 if (SemaRef.hasMergedDefinitionInCurrentModule(cast<NamedDecl>(DC))) {
1567 VisibleWithinParent = true;
1570 DC = DC->getLexicalParent();
1571 } while (!IsEffectivelyFileContext(DC));
1573 VisibleWithinParent = SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC));
1576 if (VisibleWithinParent && SemaRef.CodeSynthesisContexts.empty() &&
1577 // FIXME: Do something better in this case.
1578 !SemaRef.getLangOpts().ModulesLocalVisibility) {
1579 // Cache the fact that this declaration is implicitly visible because
1580 // its parent has a visible definition.
1581 D->setVisibleDespiteOwningModule();
1583 return VisibleWithinParent;
1586 // FIXME: All uses of DeclModule below this point should also check merged
1591 // Find the extra places where we need to look.
1592 const auto &LookupModules = SemaRef.getLookupModules();
1593 if (LookupModules.empty())
1596 // If our lookup set contains the decl's module, it's visible.
1597 if (LookupModules.count(DeclModule))
1600 // If the declaration isn't exported, it's not visible in any other module.
1601 if (D->isModulePrivate())
1604 // Check whether DeclModule is transitively exported to an import of
1606 return std::any_of(LookupModules.begin(), LookupModules.end(),
1607 [&](const Module *M) {
1608 return M->isModuleVisible(DeclModule); });
1611 bool Sema::isVisibleSlow(const NamedDecl *D) {
1612 return LookupResult::isVisible(*this, const_cast<NamedDecl*>(D));
1615 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
1616 // FIXME: If there are both visible and hidden declarations, we need to take
1617 // into account whether redeclaration is possible. Example:
1619 // Non-imported module:
1622 // static int f(U); // #2, not a redeclaration of #1
1623 // int f(T); // #3, finds both, should link with #1 if T != U, but
1624 // // with #2 if T == U; neither should be ambiguous.
1628 assert(D->isExternallyDeclarable() &&
1629 "should not have hidden, non-externally-declarable result here");
1632 // This function is called once "New" is essentially complete, but before a
1633 // previous declaration is attached. We can't query the linkage of "New" in
1634 // general, because attaching the previous declaration can change the
1635 // linkage of New to match the previous declaration.
1637 // However, because we've just determined that there is no *visible* prior
1638 // declaration, we can compute the linkage here. There are two possibilities:
1640 // * This is not a redeclaration; it's safe to compute the linkage now.
1642 // * This is a redeclaration of a prior declaration that is externally
1643 // redeclarable. In that case, the linkage of the declaration is not
1644 // changed by attaching the prior declaration, because both are externally
1645 // declarable (and thus ExternalLinkage or VisibleNoLinkage).
1647 // FIXME: This is subtle and fragile.
1648 return New->isExternallyDeclarable();
1651 /// \brief Retrieve the visible declaration corresponding to D, if any.
1653 /// This routine determines whether the declaration D is visible in the current
1654 /// module, with the current imports. If not, it checks whether any
1655 /// redeclaration of D is visible, and if so, returns that declaration.
1657 /// \returns D, or a visible previous declaration of D, whichever is more recent
1658 /// and visible. If no declaration of D is visible, returns null.
1659 static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D) {
1660 assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case");
1662 for (auto RD : D->redecls()) {
1663 // Don't bother with extra checks if we already know this one isn't visible.
1667 auto ND = cast<NamedDecl>(RD);
1668 // FIXME: This is wrong in the case where the previous declaration is not
1669 // visible in the same scope as D. This needs to be done much more
1671 if (LookupResult::isVisible(SemaRef, ND))
1678 bool Sema::hasVisibleDeclarationSlow(const NamedDecl *D,
1679 llvm::SmallVectorImpl<Module *> *Modules) {
1680 assert(!isVisible(D) && "not in slow case");
1681 return hasVisibleDeclarationImpl(*this, D, Modules,
1682 [](const NamedDecl *) { return true; });
1685 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
1686 if (auto *ND = dyn_cast<NamespaceDecl>(D)) {
1687 // Namespaces are a bit of a special case: we expect there to be a lot of
1688 // redeclarations of some namespaces, all declarations of a namespace are
1689 // essentially interchangeable, all declarations are found by name lookup
1690 // if any is, and namespaces are never looked up during template
1691 // instantiation. So we benefit from caching the check in this case, and
1692 // it is correct to do so.
1693 auto *Key = ND->getCanonicalDecl();
1694 if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key))
1697 isVisible(getSema(), Key) ? Key : findAcceptableDecl(getSema(), Key);
1699 getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable));
1703 return findAcceptableDecl(getSema(), D);
1706 /// @brief Perform unqualified name lookup starting from a given
1709 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
1710 /// used to find names within the current scope. For example, 'x' in
1714 /// return x; // unqualified name look finds 'x' in the global scope
1718 /// Different lookup criteria can find different names. For example, a
1719 /// particular scope can have both a struct and a function of the same
1720 /// name, and each can be found by certain lookup criteria. For more
1721 /// information about lookup criteria, see the documentation for the
1722 /// class LookupCriteria.
1724 /// @param S The scope from which unqualified name lookup will
1725 /// begin. If the lookup criteria permits, name lookup may also search
1726 /// in the parent scopes.
1728 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to
1729 /// look up and the lookup kind), and is updated with the results of lookup
1730 /// including zero or more declarations and possibly additional information
1731 /// used to diagnose ambiguities.
1733 /// @returns \c true if lookup succeeded and false otherwise.
1734 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
1735 DeclarationName Name = R.getLookupName();
1736 if (!Name) return false;
1738 LookupNameKind NameKind = R.getLookupKind();
1740 if (!getLangOpts().CPlusPlus) {
1741 // Unqualified name lookup in C/Objective-C is purely lexical, so
1742 // search in the declarations attached to the name.
1743 if (NameKind == Sema::LookupRedeclarationWithLinkage) {
1744 // Find the nearest non-transparent declaration scope.
1745 while (!(S->getFlags() & Scope::DeclScope) ||
1746 (S->getEntity() && S->getEntity()->isTransparentContext()))
1750 // When performing a scope lookup, we want to find local extern decls.
1751 FindLocalExternScope FindLocals(R);
1753 // Scan up the scope chain looking for a decl that matches this
1754 // identifier that is in the appropriate namespace. This search
1755 // should not take long, as shadowing of names is uncommon, and
1756 // deep shadowing is extremely uncommon.
1757 bool LeftStartingScope = false;
1759 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
1760 IEnd = IdResolver.end();
1762 if (NamedDecl *D = R.getAcceptableDecl(*I)) {
1763 if (NameKind == LookupRedeclarationWithLinkage) {
1764 // Determine whether this (or a previous) declaration is
1766 if (!LeftStartingScope && !S->isDeclScope(*I))
1767 LeftStartingScope = true;
1769 // If we found something outside of our starting scope that
1770 // does not have linkage, skip it.
1771 if (LeftStartingScope && !((*I)->hasLinkage())) {
1776 else if (NameKind == LookupObjCImplicitSelfParam &&
1777 !isa<ImplicitParamDecl>(*I))
1782 // Check whether there are any other declarations with the same name
1783 // and in the same scope.
1785 // Find the scope in which this declaration was declared (if it
1786 // actually exists in a Scope).
1787 while (S && !S->isDeclScope(D))
1790 // If the scope containing the declaration is the translation unit,
1791 // then we'll need to perform our checks based on the matching
1792 // DeclContexts rather than matching scopes.
1793 if (S && isNamespaceOrTranslationUnitScope(S))
1796 // Compute the DeclContext, if we need it.
1797 DeclContext *DC = nullptr;
1799 DC = (*I)->getDeclContext()->getRedeclContext();
1801 IdentifierResolver::iterator LastI = I;
1802 for (++LastI; LastI != IEnd; ++LastI) {
1804 // Match based on scope.
1805 if (!S->isDeclScope(*LastI))
1808 // Match based on DeclContext.
1810 = (*LastI)->getDeclContext()->getRedeclContext();
1811 if (!LastDC->Equals(DC))
1815 // If the declaration is in the right namespace and visible, add it.
1816 if (NamedDecl *LastD = R.getAcceptableDecl(*LastI))
1826 // Perform C++ unqualified name lookup.
1827 if (CppLookupName(R, S))
1831 // If we didn't find a use of this identifier, and if the identifier
1832 // corresponds to a compiler builtin, create the decl object for the builtin
1833 // now, injecting it into translation unit scope, and return it.
1834 if (AllowBuiltinCreation && LookupBuiltin(*this, R))
1837 // If we didn't find a use of this identifier, the ExternalSource
1838 // may be able to handle the situation.
1839 // Note: some lookup failures are expected!
1840 // See e.g. R.isForRedeclaration().
1841 return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
1844 /// @brief Perform qualified name lookup in the namespaces nominated by
1845 /// using directives by the given context.
1847 /// C++98 [namespace.qual]p2:
1848 /// Given X::m (where X is a user-declared namespace), or given \::m
1849 /// (where X is the global namespace), let S be the set of all
1850 /// declarations of m in X and in the transitive closure of all
1851 /// namespaces nominated by using-directives in X and its used
1852 /// namespaces, except that using-directives are ignored in any
1853 /// namespace, including X, directly containing one or more
1854 /// declarations of m. No namespace is searched more than once in
1855 /// the lookup of a name. If S is the empty set, the program is
1856 /// ill-formed. Otherwise, if S has exactly one member, or if the
1857 /// context of the reference is a using-declaration
1858 /// (namespace.udecl), S is the required set of declarations of
1859 /// m. Otherwise if the use of m is not one that allows a unique
1860 /// declaration to be chosen from S, the program is ill-formed.
1862 /// C++98 [namespace.qual]p5:
1863 /// During the lookup of a qualified namespace member name, if the
1864 /// lookup finds more than one declaration of the member, and if one
1865 /// declaration introduces a class name or enumeration name and the
1866 /// other declarations either introduce the same object, the same
1867 /// enumerator or a set of functions, the non-type name hides the
1868 /// class or enumeration name if and only if the declarations are
1869 /// from the same namespace; otherwise (the declarations are from
1870 /// different namespaces), the program is ill-formed.
1871 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
1872 DeclContext *StartDC) {
1873 assert(StartDC->isFileContext() && "start context is not a file context");
1875 // We have not yet looked into these namespaces, much less added
1876 // their "using-children" to the queue.
1877 SmallVector<NamespaceDecl*, 8> Queue;
1879 // We have at least added all these contexts to the queue.
1880 llvm::SmallPtrSet<DeclContext*, 8> Visited;
1881 Visited.insert(StartDC);
1883 // We have already looked into the initial namespace; seed the queue
1884 // with its using-children.
1885 for (auto *I : StartDC->using_directives()) {
1886 NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace();
1887 if (S.isVisible(I) && Visited.insert(ND).second)
1888 Queue.push_back(ND);
1891 // The easiest way to implement the restriction in [namespace.qual]p5
1892 // is to check whether any of the individual results found a tag
1893 // and, if so, to declare an ambiguity if the final result is not
1895 bool FoundTag = false;
1896 bool FoundNonTag = false;
1898 LookupResult LocalR(LookupResult::Temporary, R);
1901 while (!Queue.empty()) {
1902 NamespaceDecl *ND = Queue.pop_back_val();
1904 // We go through some convolutions here to avoid copying results
1905 // between LookupResults.
1906 bool UseLocal = !R.empty();
1907 LookupResult &DirectR = UseLocal ? LocalR : R;
1908 bool FoundDirect = LookupDirect(S, DirectR, ND);
1911 // First do any local hiding.
1912 DirectR.resolveKind();
1914 // If the local result is a tag, remember that.
1915 if (DirectR.isSingleTagDecl())
1920 // Append the local results to the total results if necessary.
1922 R.addAllDecls(LocalR);
1927 // If we find names in this namespace, ignore its using directives.
1933 for (auto I : ND->using_directives()) {
1934 NamespaceDecl *Nom = I->getNominatedNamespace();
1935 if (S.isVisible(I) && Visited.insert(Nom).second)
1936 Queue.push_back(Nom);
1941 if (FoundTag && FoundNonTag)
1942 R.setAmbiguousQualifiedTagHiding();
1950 /// \brief Callback that looks for any member of a class with the given name.
1951 static bool LookupAnyMember(const CXXBaseSpecifier *Specifier,
1952 CXXBasePath &Path, DeclarationName Name) {
1953 RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
1955 Path.Decls = BaseRecord->lookup(Name);
1956 return !Path.Decls.empty();
1959 /// \brief Determine whether the given set of member declarations contains only
1960 /// static members, nested types, and enumerators.
1961 template<typename InputIterator>
1962 static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) {
1963 Decl *D = (*First)->getUnderlyingDecl();
1964 if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D))
1967 if (isa<CXXMethodDecl>(D)) {
1968 // Determine whether all of the methods are static.
1969 bool AllMethodsAreStatic = true;
1970 for(; First != Last; ++First) {
1971 D = (*First)->getUnderlyingDecl();
1973 if (!isa<CXXMethodDecl>(D)) {
1974 assert(isa<TagDecl>(D) && "Non-function must be a tag decl");
1978 if (!cast<CXXMethodDecl>(D)->isStatic()) {
1979 AllMethodsAreStatic = false;
1984 if (AllMethodsAreStatic)
1991 /// \brief Perform qualified name lookup into a given context.
1993 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
1994 /// names when the context of those names is explicit specified, e.g.,
1995 /// "std::vector" or "x->member", or as part of unqualified name lookup.
1997 /// Different lookup criteria can find different names. For example, a
1998 /// particular scope can have both a struct and a function of the same
1999 /// name, and each can be found by certain lookup criteria. For more
2000 /// information about lookup criteria, see the documentation for the
2001 /// class LookupCriteria.
2003 /// \param R captures both the lookup criteria and any lookup results found.
2005 /// \param LookupCtx The context in which qualified name lookup will
2006 /// search. If the lookup criteria permits, name lookup may also search
2007 /// in the parent contexts or (for C++ classes) base classes.
2009 /// \param InUnqualifiedLookup true if this is qualified name lookup that
2010 /// occurs as part of unqualified name lookup.
2012 /// \returns true if lookup succeeded, false if it failed.
2013 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2014 bool InUnqualifiedLookup) {
2015 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
2017 if (!R.getLookupName())
2020 // Make sure that the declaration context is complete.
2021 assert((!isa<TagDecl>(LookupCtx) ||
2022 LookupCtx->isDependentContext() ||
2023 cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
2024 cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
2025 "Declaration context must already be complete!");
2027 struct QualifiedLookupInScope {
2029 DeclContext *Context;
2030 // Set flag in DeclContext informing debugger that we're looking for qualified name
2031 QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) {
2032 oldVal = ctx->setUseQualifiedLookup();
2034 ~QualifiedLookupInScope() {
2035 Context->setUseQualifiedLookup(oldVal);
2039 if (LookupDirect(*this, R, LookupCtx)) {
2041 if (isa<CXXRecordDecl>(LookupCtx))
2042 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
2046 // Don't descend into implied contexts for redeclarations.
2047 // C++98 [namespace.qual]p6:
2048 // In a declaration for a namespace member in which the
2049 // declarator-id is a qualified-id, given that the qualified-id
2050 // for the namespace member has the form
2051 // nested-name-specifier unqualified-id
2052 // the unqualified-id shall name a member of the namespace
2053 // designated by the nested-name-specifier.
2054 // See also [class.mfct]p5 and [class.static.data]p2.
2055 if (R.isForRedeclaration())
2058 // If this is a namespace, look it up in the implied namespaces.
2059 if (LookupCtx->isFileContext())
2060 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
2062 // If this isn't a C++ class, we aren't allowed to look into base
2063 // classes, we're done.
2064 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
2065 if (!LookupRec || !LookupRec->getDefinition())
2068 // If we're performing qualified name lookup into a dependent class,
2069 // then we are actually looking into a current instantiation. If we have any
2070 // dependent base classes, then we either have to delay lookup until
2071 // template instantiation time (at which point all bases will be available)
2072 // or we have to fail.
2073 if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
2074 LookupRec->hasAnyDependentBases()) {
2075 R.setNotFoundInCurrentInstantiation();
2079 // Perform lookup into our base classes.
2081 Paths.setOrigin(LookupRec);
2083 // Look for this member in our base classes
2084 bool (*BaseCallback)(const CXXBaseSpecifier *Specifier, CXXBasePath &Path,
2085 DeclarationName Name) = nullptr;
2086 switch (R.getLookupKind()) {
2087 case LookupObjCImplicitSelfParam:
2088 case LookupOrdinaryName:
2089 case LookupMemberName:
2090 case LookupRedeclarationWithLinkage:
2091 case LookupLocalFriendName:
2092 BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
2096 BaseCallback = &CXXRecordDecl::FindTagMember;
2100 BaseCallback = &LookupAnyMember;
2103 case LookupOMPReductionName:
2104 BaseCallback = &CXXRecordDecl::FindOMPReductionMember;
2107 case LookupUsingDeclName:
2108 // This lookup is for redeclarations only.
2110 case LookupOperatorName:
2111 case LookupNamespaceName:
2112 case LookupObjCProtocolName:
2114 // These lookups will never find a member in a C++ class (or base class).
2117 case LookupNestedNameSpecifierName:
2118 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember;
2122 DeclarationName Name = R.getLookupName();
2123 if (!LookupRec->lookupInBases(
2124 [=](const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
2125 return BaseCallback(Specifier, Path, Name);
2130 R.setNamingClass(LookupRec);
2132 // C++ [class.member.lookup]p2:
2133 // [...] If the resulting set of declarations are not all from
2134 // sub-objects of the same type, or the set has a nonstatic member
2135 // and includes members from distinct sub-objects, there is an
2136 // ambiguity and the program is ill-formed. Otherwise that set is
2137 // the result of the lookup.
2138 QualType SubobjectType;
2139 int SubobjectNumber = 0;
2140 AccessSpecifier SubobjectAccess = AS_none;
2142 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
2143 Path != PathEnd; ++Path) {
2144 const CXXBasePathElement &PathElement = Path->back();
2146 // Pick the best (i.e. most permissive i.e. numerically lowest) access
2147 // across all paths.
2148 SubobjectAccess = std::min(SubobjectAccess, Path->Access);
2150 // Determine whether we're looking at a distinct sub-object or not.
2151 if (SubobjectType.isNull()) {
2152 // This is the first subobject we've looked at. Record its type.
2153 SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
2154 SubobjectNumber = PathElement.SubobjectNumber;
2159 != Context.getCanonicalType(PathElement.Base->getType())) {
2160 // We found members of the given name in two subobjects of
2161 // different types. If the declaration sets aren't the same, this
2162 // lookup is ambiguous.
2163 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) {
2164 CXXBasePaths::paths_iterator FirstPath = Paths.begin();
2165 DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin();
2166 DeclContext::lookup_iterator CurrentD = Path->Decls.begin();
2168 while (FirstD != FirstPath->Decls.end() &&
2169 CurrentD != Path->Decls.end()) {
2170 if ((*FirstD)->getUnderlyingDecl()->getCanonicalDecl() !=
2171 (*CurrentD)->getUnderlyingDecl()->getCanonicalDecl())
2178 if (FirstD == FirstPath->Decls.end() &&
2179 CurrentD == Path->Decls.end())
2183 R.setAmbiguousBaseSubobjectTypes(Paths);
2187 if (SubobjectNumber != PathElement.SubobjectNumber) {
2188 // We have a different subobject of the same type.
2190 // C++ [class.member.lookup]p5:
2191 // A static member, a nested type or an enumerator defined in
2192 // a base class T can unambiguously be found even if an object
2193 // has more than one base class subobject of type T.
2194 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end()))
2197 // We have found a nonstatic member name in multiple, distinct
2198 // subobjects. Name lookup is ambiguous.
2199 R.setAmbiguousBaseSubobjects(Paths);
2204 // Lookup in a base class succeeded; return these results.
2206 for (auto *D : Paths.front().Decls) {
2207 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
2215 /// \brief Performs qualified name lookup or special type of lookup for
2216 /// "__super::" scope specifier.
2218 /// This routine is a convenience overload meant to be called from contexts
2219 /// that need to perform a qualified name lookup with an optional C++ scope
2220 /// specifier that might require special kind of lookup.
2222 /// \param R captures both the lookup criteria and any lookup results found.
2224 /// \param LookupCtx The context in which qualified name lookup will
2227 /// \param SS An optional C++ scope-specifier.
2229 /// \returns true if lookup succeeded, false if it failed.
2230 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2232 auto *NNS = SS.getScopeRep();
2233 if (NNS && NNS->getKind() == NestedNameSpecifier::Super)
2234 return LookupInSuper(R, NNS->getAsRecordDecl());
2237 return LookupQualifiedName(R, LookupCtx);
2240 /// @brief Performs name lookup for a name that was parsed in the
2241 /// source code, and may contain a C++ scope specifier.
2243 /// This routine is a convenience routine meant to be called from
2244 /// contexts that receive a name and an optional C++ scope specifier
2245 /// (e.g., "N::M::x"). It will then perform either qualified or
2246 /// unqualified name lookup (with LookupQualifiedName or LookupName,
2247 /// respectively) on the given name and return those results. It will
2248 /// perform a special type of lookup for "__super::" scope specifier.
2250 /// @param S The scope from which unqualified name lookup will
2253 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
2255 /// @param EnteringContext Indicates whether we are going to enter the
2256 /// context of the scope-specifier SS (if present).
2258 /// @returns True if any decls were found (but possibly ambiguous)
2259 bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
2260 bool AllowBuiltinCreation, bool EnteringContext) {
2261 if (SS && SS->isInvalid()) {
2262 // When the scope specifier is invalid, don't even look for
2267 if (SS && SS->isSet()) {
2268 NestedNameSpecifier *NNS = SS->getScopeRep();
2269 if (NNS->getKind() == NestedNameSpecifier::Super)
2270 return LookupInSuper(R, NNS->getAsRecordDecl());
2272 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
2273 // We have resolved the scope specifier to a particular declaration
2274 // contex, and will perform name lookup in that context.
2275 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
2278 R.setContextRange(SS->getRange());
2279 return LookupQualifiedName(R, DC);
2282 // We could not resolve the scope specified to a specific declaration
2283 // context, which means that SS refers to an unknown specialization.
2284 // Name lookup can't find anything in this case.
2285 R.setNotFoundInCurrentInstantiation();
2286 R.setContextRange(SS->getRange());
2290 // Perform unqualified name lookup starting in the given scope.
2291 return LookupName(R, S, AllowBuiltinCreation);
2294 /// \brief Perform qualified name lookup into all base classes of the given
2297 /// \param R captures both the lookup criteria and any lookup results found.
2299 /// \param Class The context in which qualified name lookup will
2300 /// search. Name lookup will search in all base classes merging the results.
2302 /// @returns True if any decls were found (but possibly ambiguous)
2303 bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) {
2304 // The access-control rules we use here are essentially the rules for
2305 // doing a lookup in Class that just magically skipped the direct
2306 // members of Class itself. That is, the naming class is Class, and the
2307 // access includes the access of the base.
2308 for (const auto &BaseSpec : Class->bases()) {
2309 CXXRecordDecl *RD = cast<CXXRecordDecl>(
2310 BaseSpec.getType()->castAs<RecordType>()->getDecl());
2311 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
2312 Result.setBaseObjectType(Context.getRecordType(Class));
2313 LookupQualifiedName(Result, RD);
2315 // Copy the lookup results into the target, merging the base's access into
2317 for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
2318 R.addDecl(I.getDecl(),
2319 CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(),
2323 Result.suppressDiagnostics();
2327 R.setNamingClass(Class);
2332 /// \brief Produce a diagnostic describing the ambiguity that resulted
2333 /// from name lookup.
2335 /// \param Result The result of the ambiguous lookup to be diagnosed.
2336 void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
2337 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
2339 DeclarationName Name = Result.getLookupName();
2340 SourceLocation NameLoc = Result.getNameLoc();
2341 SourceRange LookupRange = Result.getContextRange();
2343 switch (Result.getAmbiguityKind()) {
2344 case LookupResult::AmbiguousBaseSubobjects: {
2345 CXXBasePaths *Paths = Result.getBasePaths();
2346 QualType SubobjectType = Paths->front().back().Base->getType();
2347 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
2348 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
2351 DeclContext::lookup_iterator Found = Paths->front().Decls.begin();
2352 while (isa<CXXMethodDecl>(*Found) &&
2353 cast<CXXMethodDecl>(*Found)->isStatic())
2356 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
2360 case LookupResult::AmbiguousBaseSubobjectTypes: {
2361 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
2362 << Name << LookupRange;
2364 CXXBasePaths *Paths = Result.getBasePaths();
2365 std::set<Decl *> DeclsPrinted;
2366 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
2367 PathEnd = Paths->end();
2368 Path != PathEnd; ++Path) {
2369 Decl *D = Path->Decls.front();
2370 if (DeclsPrinted.insert(D).second)
2371 Diag(D->getLocation(), diag::note_ambiguous_member_found);
2376 case LookupResult::AmbiguousTagHiding: {
2377 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
2379 llvm::SmallPtrSet<NamedDecl*, 8> TagDecls;
2381 for (auto *D : Result)
2382 if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
2383 TagDecls.insert(TD);
2384 Diag(TD->getLocation(), diag::note_hidden_tag);
2387 for (auto *D : Result)
2388 if (!isa<TagDecl>(D))
2389 Diag(D->getLocation(), diag::note_hiding_object);
2391 // For recovery purposes, go ahead and implement the hiding.
2392 LookupResult::Filter F = Result.makeFilter();
2393 while (F.hasNext()) {
2394 if (TagDecls.count(F.next()))
2401 case LookupResult::AmbiguousReference: {
2402 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
2404 for (auto *D : Result)
2405 Diag(D->getLocation(), diag::note_ambiguous_candidate) << D;
2412 struct AssociatedLookup {
2413 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
2414 Sema::AssociatedNamespaceSet &Namespaces,
2415 Sema::AssociatedClassSet &Classes)
2416 : S(S), Namespaces(Namespaces), Classes(Classes),
2417 InstantiationLoc(InstantiationLoc) {
2421 Sema::AssociatedNamespaceSet &Namespaces;
2422 Sema::AssociatedClassSet &Classes;
2423 SourceLocation InstantiationLoc;
2425 } // end anonymous namespace
2428 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
2430 static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces,
2432 // Add the associated namespace for this class.
2434 // We don't use DeclContext::getEnclosingNamespaceContext() as this may
2435 // be a locally scoped record.
2437 // We skip out of inline namespaces. The innermost non-inline namespace
2438 // contains all names of all its nested inline namespaces anyway, so we can
2439 // replace the entire inline namespace tree with its root.
2440 while (Ctx->isRecord() || Ctx->isTransparentContext() ||
2441 Ctx->isInlineNamespace())
2442 Ctx = Ctx->getParent();
2444 if (Ctx->isFileContext())
2445 Namespaces.insert(Ctx->getPrimaryContext());
2448 // \brief Add the associated classes and namespaces for argument-dependent
2449 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2).
2451 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2452 const TemplateArgument &Arg) {
2453 // C++ [basic.lookup.koenig]p2, last bullet:
2455 switch (Arg.getKind()) {
2456 case TemplateArgument::Null:
2459 case TemplateArgument::Type:
2460 // [...] the namespaces and classes associated with the types of the
2461 // template arguments provided for template type parameters (excluding
2462 // template template parameters)
2463 addAssociatedClassesAndNamespaces(Result, Arg.getAsType());
2466 case TemplateArgument::Template:
2467 case TemplateArgument::TemplateExpansion: {
2468 // [...] the namespaces in which any template template arguments are
2469 // defined; and the classes in which any member templates used as
2470 // template template arguments are defined.
2471 TemplateName Template = Arg.getAsTemplateOrTemplatePattern();
2472 if (ClassTemplateDecl *ClassTemplate
2473 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
2474 DeclContext *Ctx = ClassTemplate->getDeclContext();
2475 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2476 Result.Classes.insert(EnclosingClass);
2477 // Add the associated namespace for this class.
2478 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2483 case TemplateArgument::Declaration:
2484 case TemplateArgument::Integral:
2485 case TemplateArgument::Expression:
2486 case TemplateArgument::NullPtr:
2487 // [Note: non-type template arguments do not contribute to the set of
2488 // associated namespaces. ]
2491 case TemplateArgument::Pack:
2492 for (const auto &P : Arg.pack_elements())
2493 addAssociatedClassesAndNamespaces(Result, P);
2498 // \brief Add the associated classes and namespaces for
2499 // argument-dependent lookup with an argument of class type
2500 // (C++ [basic.lookup.koenig]p2).
2502 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2503 CXXRecordDecl *Class) {
2505 // Just silently ignore anything whose name is __va_list_tag.
2506 if (Class->getDeclName() == Result.S.VAListTagName)
2509 // C++ [basic.lookup.koenig]p2:
2511 // -- If T is a class type (including unions), its associated
2512 // classes are: the class itself; the class of which it is a
2513 // member, if any; and its direct and indirect base
2514 // classes. Its associated namespaces are the namespaces in
2515 // which its associated classes are defined.
2517 // Add the class of which it is a member, if any.
2518 DeclContext *Ctx = Class->getDeclContext();
2519 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2520 Result.Classes.insert(EnclosingClass);
2521 // Add the associated namespace for this class.
2522 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2524 // Add the class itself. If we've already seen this class, we don't
2525 // need to visit base classes.
2527 // FIXME: That's not correct, we may have added this class only because it
2528 // was the enclosing class of another class, and in that case we won't have
2529 // added its base classes yet.
2530 if (!Result.Classes.insert(Class))
2533 // -- If T is a template-id, its associated namespaces and classes are
2534 // the namespace in which the template is defined; for member
2535 // templates, the member template's class; the namespaces and classes
2536 // associated with the types of the template arguments provided for
2537 // template type parameters (excluding template template parameters); the
2538 // namespaces in which any template template arguments are defined; and
2539 // the classes in which any member templates used as template template
2540 // arguments are defined. [Note: non-type template arguments do not
2541 // contribute to the set of associated namespaces. ]
2542 if (ClassTemplateSpecializationDecl *Spec
2543 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
2544 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
2545 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2546 Result.Classes.insert(EnclosingClass);
2547 // Add the associated namespace for this class.
2548 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2550 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
2551 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2552 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]);
2555 // Only recurse into base classes for complete types.
2556 if (!Result.S.isCompleteType(Result.InstantiationLoc,
2557 Result.S.Context.getRecordType(Class)))
2560 // Add direct and indirect base classes along with their associated
2562 SmallVector<CXXRecordDecl *, 32> Bases;
2563 Bases.push_back(Class);
2564 while (!Bases.empty()) {
2565 // Pop this class off the stack.
2566 Class = Bases.pop_back_val();
2568 // Visit the base classes.
2569 for (const auto &Base : Class->bases()) {
2570 const RecordType *BaseType = Base.getType()->getAs<RecordType>();
2571 // In dependent contexts, we do ADL twice, and the first time around,
2572 // the base type might be a dependent TemplateSpecializationType, or a
2573 // TemplateTypeParmType. If that happens, simply ignore it.
2574 // FIXME: If we want to support export, we probably need to add the
2575 // namespace of the template in a TemplateSpecializationType, or even
2576 // the classes and namespaces of known non-dependent arguments.
2579 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
2580 if (Result.Classes.insert(BaseDecl)) {
2581 // Find the associated namespace for this base class.
2582 DeclContext *BaseCtx = BaseDecl->getDeclContext();
2583 CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
2585 // Make sure we visit the bases of this base class.
2586 if (BaseDecl->bases_begin() != BaseDecl->bases_end())
2587 Bases.push_back(BaseDecl);
2593 // \brief Add the associated classes and namespaces for
2594 // argument-dependent lookup with an argument of type T
2595 // (C++ [basic.lookup.koenig]p2).
2597 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
2598 // C++ [basic.lookup.koenig]p2:
2600 // For each argument type T in the function call, there is a set
2601 // of zero or more associated namespaces and a set of zero or more
2602 // associated classes to be considered. The sets of namespaces and
2603 // classes is determined entirely by the types of the function
2604 // arguments (and the namespace of any template template
2605 // argument). Typedef names and using-declarations used to specify
2606 // the types do not contribute to this set. The sets of namespaces
2607 // and classes are determined in the following way:
2609 SmallVector<const Type *, 16> Queue;
2610 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
2613 switch (T->getTypeClass()) {
2615 #define TYPE(Class, Base)
2616 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
2617 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
2618 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
2619 #define ABSTRACT_TYPE(Class, Base)
2620 #include "clang/AST/TypeNodes.def"
2621 // T is canonical. We can also ignore dependent types because
2622 // we don't need to do ADL at the definition point, but if we
2623 // wanted to implement template export (or if we find some other
2624 // use for associated classes and namespaces...) this would be
2628 // -- If T is a pointer to U or an array of U, its associated
2629 // namespaces and classes are those associated with U.
2631 T = cast<PointerType>(T)->getPointeeType().getTypePtr();
2633 case Type::ConstantArray:
2634 case Type::IncompleteArray:
2635 case Type::VariableArray:
2636 T = cast<ArrayType>(T)->getElementType().getTypePtr();
2639 // -- If T is a fundamental type, its associated sets of
2640 // namespaces and classes are both empty.
2644 // -- If T is a class type (including unions), its associated
2645 // classes are: the class itself; the class of which it is a
2646 // member, if any; and its direct and indirect base
2647 // classes. Its associated namespaces are the namespaces in
2648 // which its associated classes are defined.
2649 case Type::Record: {
2650 CXXRecordDecl *Class =
2651 cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl());
2652 addAssociatedClassesAndNamespaces(Result, Class);
2656 // -- If T is an enumeration type, its associated namespace is
2657 // the namespace in which it is defined. If it is class
2658 // member, its associated class is the member's class; else
2659 // it has no associated class.
2661 EnumDecl *Enum = cast<EnumType>(T)->getDecl();
2663 DeclContext *Ctx = Enum->getDeclContext();
2664 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2665 Result.Classes.insert(EnclosingClass);
2667 // Add the associated namespace for this class.
2668 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2673 // -- If T is a function type, its associated namespaces and
2674 // classes are those associated with the function parameter
2675 // types and those associated with the return type.
2676 case Type::FunctionProto: {
2677 const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
2678 for (const auto &Arg : Proto->param_types())
2679 Queue.push_back(Arg.getTypePtr());
2683 case Type::FunctionNoProto: {
2684 const FunctionType *FnType = cast<FunctionType>(T);
2685 T = FnType->getReturnType().getTypePtr();
2689 // -- If T is a pointer to a member function of a class X, its
2690 // associated namespaces and classes are those associated
2691 // with the function parameter types and return type,
2692 // together with those associated with X.
2694 // -- If T is a pointer to a data member of class X, its
2695 // associated namespaces and classes are those associated
2696 // with the member type together with those associated with
2698 case Type::MemberPointer: {
2699 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T);
2701 // Queue up the class type into which this points.
2702 Queue.push_back(MemberPtr->getClass());
2704 // And directly continue with the pointee type.
2705 T = MemberPtr->getPointeeType().getTypePtr();
2709 // As an extension, treat this like a normal pointer.
2710 case Type::BlockPointer:
2711 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr();
2714 // References aren't covered by the standard, but that's such an
2715 // obvious defect that we cover them anyway.
2716 case Type::LValueReference:
2717 case Type::RValueReference:
2718 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr();
2721 // These are fundamental types.
2723 case Type::ExtVector:
2727 // Non-deduced auto types only get here for error cases.
2729 case Type::DeducedTemplateSpecialization:
2732 // If T is an Objective-C object or interface type, or a pointer to an
2733 // object or interface type, the associated namespace is the global
2735 case Type::ObjCObject:
2736 case Type::ObjCInterface:
2737 case Type::ObjCObjectPointer:
2738 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
2741 // Atomic types are just wrappers; use the associations of the
2744 T = cast<AtomicType>(T)->getValueType().getTypePtr();
2747 T = cast<PipeType>(T)->getElementType().getTypePtr();
2753 T = Queue.pop_back_val();
2757 /// \brief Find the associated classes and namespaces for
2758 /// argument-dependent lookup for a call with the given set of
2761 /// This routine computes the sets of associated classes and associated
2762 /// namespaces searched by argument-dependent lookup
2763 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
2764 void Sema::FindAssociatedClassesAndNamespaces(
2765 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
2766 AssociatedNamespaceSet &AssociatedNamespaces,
2767 AssociatedClassSet &AssociatedClasses) {
2768 AssociatedNamespaces.clear();
2769 AssociatedClasses.clear();
2771 AssociatedLookup Result(*this, InstantiationLoc,
2772 AssociatedNamespaces, AssociatedClasses);
2774 // C++ [basic.lookup.koenig]p2:
2775 // For each argument type T in the function call, there is a set
2776 // of zero or more associated namespaces and a set of zero or more
2777 // associated classes to be considered. The sets of namespaces and
2778 // classes is determined entirely by the types of the function
2779 // arguments (and the namespace of any template template
2781 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
2782 Expr *Arg = Args[ArgIdx];
2784 if (Arg->getType() != Context.OverloadTy) {
2785 addAssociatedClassesAndNamespaces(Result, Arg->getType());
2789 // [...] In addition, if the argument is the name or address of a
2790 // set of overloaded functions and/or function templates, its
2791 // associated classes and namespaces are the union of those
2792 // associated with each of the members of the set: the namespace
2793 // in which the function or function template is defined and the
2794 // classes and namespaces associated with its (non-dependent)
2795 // parameter types and return type.
2796 Arg = Arg->IgnoreParens();
2797 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg))
2798 if (unaryOp->getOpcode() == UO_AddrOf)
2799 Arg = unaryOp->getSubExpr();
2801 UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg);
2804 for (const auto *D : ULE->decls()) {
2805 // Look through any using declarations to find the underlying function.
2806 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
2808 // Add the classes and namespaces associated with the parameter
2809 // types and return type of this function.
2810 addAssociatedClassesAndNamespaces(Result, FDecl->getType());
2815 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
2817 LookupNameKind NameKind,
2818 RedeclarationKind Redecl) {
2819 LookupResult R(*this, Name, Loc, NameKind, Redecl);
2821 return R.getAsSingle<NamedDecl>();
2824 /// \brief Find the protocol with the given name, if any.
2825 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II,
2826 SourceLocation IdLoc,
2827 RedeclarationKind Redecl) {
2828 Decl *D = LookupSingleName(TUScope, II, IdLoc,
2829 LookupObjCProtocolName, Redecl);
2830 return cast_or_null<ObjCProtocolDecl>(D);
2833 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
2834 QualType T1, QualType T2,
2835 UnresolvedSetImpl &Functions) {
2836 // C++ [over.match.oper]p3:
2837 // -- The set of non-member candidates is the result of the
2838 // unqualified lookup of operator@ in the context of the
2839 // expression according to the usual rules for name lookup in
2840 // unqualified function calls (3.4.2) except that all member
2841 // functions are ignored.
2842 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
2843 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
2844 LookupName(Operators, S);
2846 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
2847 Functions.append(Operators.begin(), Operators.end());
2850 Sema::SpecialMemberOverloadResult Sema::LookupSpecialMember(CXXRecordDecl *RD,
2851 CXXSpecialMember SM,
2856 bool VolatileThis) {
2857 assert(CanDeclareSpecialMemberFunction(RD) &&
2858 "doing special member lookup into record that isn't fully complete");
2859 RD = RD->getDefinition();
2860 if (RValueThis || ConstThis || VolatileThis)
2861 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) &&
2862 "constructors and destructors always have unqualified lvalue this");
2863 if (ConstArg || VolatileArg)
2864 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) &&
2865 "parameter-less special members can't have qualified arguments");
2867 // FIXME: Get the caller to pass in a location for the lookup.
2868 SourceLocation LookupLoc = RD->getLocation();
2870 llvm::FoldingSetNodeID ID;
2873 ID.AddInteger(ConstArg);
2874 ID.AddInteger(VolatileArg);
2875 ID.AddInteger(RValueThis);
2876 ID.AddInteger(ConstThis);
2877 ID.AddInteger(VolatileThis);
2880 SpecialMemberOverloadResultEntry *Result =
2881 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
2883 // This was already cached
2887 Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>();
2888 Result = new (Result) SpecialMemberOverloadResultEntry(ID);
2889 SpecialMemberCache.InsertNode(Result, InsertPoint);
2891 if (SM == CXXDestructor) {
2892 if (RD->needsImplicitDestructor())
2893 DeclareImplicitDestructor(RD);
2894 CXXDestructorDecl *DD = RD->getDestructor();
2895 assert(DD && "record without a destructor");
2896 Result->setMethod(DD);
2897 Result->setKind(DD->isDeleted() ?
2898 SpecialMemberOverloadResult::NoMemberOrDeleted :
2899 SpecialMemberOverloadResult::Success);
2903 // Prepare for overload resolution. Here we construct a synthetic argument
2904 // if necessary and make sure that implicit functions are declared.
2905 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD));
2906 DeclarationName Name;
2907 Expr *Arg = nullptr;
2910 QualType ArgType = CanTy;
2911 ExprValueKind VK = VK_LValue;
2913 if (SM == CXXDefaultConstructor) {
2914 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2916 if (RD->needsImplicitDefaultConstructor())
2917 DeclareImplicitDefaultConstructor(RD);
2919 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) {
2920 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2921 if (RD->needsImplicitCopyConstructor())
2922 DeclareImplicitCopyConstructor(RD);
2923 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor())
2924 DeclareImplicitMoveConstructor(RD);
2926 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
2927 if (RD->needsImplicitCopyAssignment())
2928 DeclareImplicitCopyAssignment(RD);
2929 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment())
2930 DeclareImplicitMoveAssignment(RD);
2936 ArgType.addVolatile();
2938 // This isn't /really/ specified by the standard, but it's implied
2939 // we should be working from an RValue in the case of move to ensure
2940 // that we prefer to bind to rvalue references, and an LValue in the
2941 // case of copy to ensure we don't bind to rvalue references.
2942 // Possibly an XValue is actually correct in the case of move, but
2943 // there is no semantic difference for class types in this restricted
2945 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment)
2951 OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK);
2953 if (SM != CXXDefaultConstructor) {
2958 // Create the object argument
2959 QualType ThisTy = CanTy;
2963 ThisTy.addVolatile();
2964 Expr::Classification Classification =
2965 OpaqueValueExpr(LookupLoc, ThisTy,
2966 RValueThis ? VK_RValue : VK_LValue).Classify(Context);
2968 // Now we perform lookup on the name we computed earlier and do overload
2969 // resolution. Lookup is only performed directly into the class since there
2970 // will always be a (possibly implicit) declaration to shadow any others.
2971 OverloadCandidateSet OCS(LookupLoc, OverloadCandidateSet::CSK_Normal);
2972 DeclContext::lookup_result R = RD->lookup(Name);
2975 // We might have no default constructor because we have a lambda's closure
2976 // type, rather than because there's some other declared constructor.
2977 // Every class has a copy/move constructor, copy/move assignment, and
2979 assert(SM == CXXDefaultConstructor &&
2980 "lookup for a constructor or assignment operator was empty");
2981 Result->setMethod(nullptr);
2982 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2986 // Copy the candidates as our processing of them may load new declarations
2987 // from an external source and invalidate lookup_result.
2988 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
2990 for (NamedDecl *CandDecl : Candidates) {
2991 if (CandDecl->isInvalidDecl())
2994 DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public);
2995 auto CtorInfo = getConstructorInfo(Cand);
2996 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl())) {
2997 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2998 AddMethodCandidate(M, Cand, RD, ThisTy, Classification,
2999 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3001 AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl,
3002 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3004 AddOverloadCandidate(M, Cand, llvm::makeArrayRef(&Arg, NumArgs), OCS,
3006 } else if (FunctionTemplateDecl *Tmpl =
3007 dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) {
3008 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
3009 AddMethodTemplateCandidate(
3010 Tmpl, Cand, RD, nullptr, ThisTy, Classification,
3011 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3013 AddTemplateOverloadCandidate(
3014 CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr,
3015 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3017 AddTemplateOverloadCandidate(
3018 Tmpl, Cand, nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
3020 assert(isa<UsingDecl>(Cand.getDecl()) &&
3021 "illegal Kind of operator = Decl");
3025 OverloadCandidateSet::iterator Best;
3026 switch (OCS.BestViableFunction(*this, LookupLoc, Best)) {
3028 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
3029 Result->setKind(SpecialMemberOverloadResult::Success);
3033 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
3034 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3038 Result->setMethod(nullptr);
3039 Result->setKind(SpecialMemberOverloadResult::Ambiguous);
3042 case OR_No_Viable_Function:
3043 Result->setMethod(nullptr);
3044 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3051 /// \brief Look up the default constructor for the given class.
3052 CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) {
3053 SpecialMemberOverloadResult Result =
3054 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false,
3057 return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3060 /// \brief Look up the copying constructor for the given class.
3061 CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class,
3063 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3064 "non-const, non-volatile qualifiers for copy ctor arg");
3065 SpecialMemberOverloadResult Result =
3066 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const,
3067 Quals & Qualifiers::Volatile, false, false, false);
3069 return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3072 /// \brief Look up the moving constructor for the given class.
3073 CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class,
3075 SpecialMemberOverloadResult Result =
3076 LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const,
3077 Quals & Qualifiers::Volatile, false, false, false);
3079 return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3082 /// \brief Look up the constructors for the given class.
3083 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) {
3084 // If the implicit constructors have not yet been declared, do so now.
3085 if (CanDeclareSpecialMemberFunction(Class)) {
3086 if (Class->needsImplicitDefaultConstructor())
3087 DeclareImplicitDefaultConstructor(Class);
3088 if (Class->needsImplicitCopyConstructor())
3089 DeclareImplicitCopyConstructor(Class);
3090 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
3091 DeclareImplicitMoveConstructor(Class);
3094 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class));
3095 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T);
3096 return Class->lookup(Name);
3099 /// \brief Look up the copying assignment operator for the given class.
3100 CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class,
3101 unsigned Quals, bool RValueThis,
3102 unsigned ThisQuals) {
3103 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3104 "non-const, non-volatile qualifiers for copy assignment arg");
3105 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3106 "non-const, non-volatile qualifiers for copy assignment this");
3107 SpecialMemberOverloadResult Result =
3108 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const,
3109 Quals & Qualifiers::Volatile, RValueThis,
3110 ThisQuals & Qualifiers::Const,
3111 ThisQuals & Qualifiers::Volatile);
3113 return Result.getMethod();
3116 /// \brief Look up the moving assignment operator for the given class.
3117 CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class,
3120 unsigned ThisQuals) {
3121 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3122 "non-const, non-volatile qualifiers for copy assignment this");
3123 SpecialMemberOverloadResult Result =
3124 LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const,
3125 Quals & Qualifiers::Volatile, RValueThis,
3126 ThisQuals & Qualifiers::Const,
3127 ThisQuals & Qualifiers::Volatile);
3129 return Result.getMethod();
3132 /// \brief Look for the destructor of the given class.
3134 /// During semantic analysis, this routine should be used in lieu of
3135 /// CXXRecordDecl::getDestructor().
3137 /// \returns The destructor for this class.
3138 CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) {
3139 return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor,
3140 false, false, false,
3141 false, false).getMethod());
3144 /// LookupLiteralOperator - Determine which literal operator should be used for
3145 /// a user-defined literal, per C++11 [lex.ext].
3147 /// Normal overload resolution is not used to select which literal operator to
3148 /// call for a user-defined literal. Look up the provided literal operator name,
3149 /// and filter the results to the appropriate set for the given argument types.
3150 Sema::LiteralOperatorLookupResult
3151 Sema::LookupLiteralOperator(Scope *S, LookupResult &R,
3152 ArrayRef<QualType> ArgTys,
3153 bool AllowRaw, bool AllowTemplate,
3154 bool AllowStringTemplate, bool DiagnoseMissing) {
3156 assert(R.getResultKind() != LookupResult::Ambiguous &&
3157 "literal operator lookup can't be ambiguous");
3159 // Filter the lookup results appropriately.
3160 LookupResult::Filter F = R.makeFilter();
3162 bool FoundRaw = false;
3163 bool FoundTemplate = false;
3164 bool FoundStringTemplate = false;
3165 bool FoundExactMatch = false;
3167 while (F.hasNext()) {
3169 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
3170 D = USD->getTargetDecl();
3172 // If the declaration we found is invalid, skip it.
3173 if (D->isInvalidDecl()) {
3179 bool IsTemplate = false;
3180 bool IsStringTemplate = false;
3181 bool IsExactMatch = false;
3183 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
3184 if (FD->getNumParams() == 1 &&
3185 FD->getParamDecl(0)->getType()->getAs<PointerType>())
3187 else if (FD->getNumParams() == ArgTys.size()) {
3188 IsExactMatch = true;
3189 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
3190 QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
3191 if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
3192 IsExactMatch = false;
3198 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) {
3199 TemplateParameterList *Params = FD->getTemplateParameters();
3200 if (Params->size() == 1)
3203 IsStringTemplate = true;
3207 FoundExactMatch = true;
3209 AllowTemplate = false;
3210 AllowStringTemplate = false;
3211 if (FoundRaw || FoundTemplate || FoundStringTemplate) {
3212 // Go through again and remove the raw and template decls we've
3215 FoundRaw = FoundTemplate = FoundStringTemplate = false;
3217 } else if (AllowRaw && IsRaw) {
3219 } else if (AllowTemplate && IsTemplate) {
3220 FoundTemplate = true;
3221 } else if (AllowStringTemplate && IsStringTemplate) {
3222 FoundStringTemplate = true;
3230 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
3231 // parameter type, that is used in preference to a raw literal operator
3232 // or literal operator template.
3233 if (FoundExactMatch)
3236 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
3237 // operator template, but not both.
3238 if (FoundRaw && FoundTemplate) {
3239 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
3240 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
3241 NoteOverloadCandidate(*I, (*I)->getUnderlyingDecl()->getAsFunction());
3249 return LOLR_Template;
3251 if (FoundStringTemplate)
3252 return LOLR_StringTemplate;
3254 // Didn't find anything we could use.
3255 if (DiagnoseMissing) {
3256 Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
3257 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
3258 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
3259 << (AllowTemplate || AllowStringTemplate);
3263 return LOLR_ErrorNoDiagnostic;
3266 void ADLResult::insert(NamedDecl *New) {
3267 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
3269 // If we haven't yet seen a decl for this key, or the last decl
3270 // was exactly this one, we're done.
3271 if (Old == nullptr || Old == New) {
3276 // Otherwise, decide which is a more recent redeclaration.
3277 FunctionDecl *OldFD = Old->getAsFunction();
3278 FunctionDecl *NewFD = New->getAsFunction();
3280 FunctionDecl *Cursor = NewFD;
3282 Cursor = Cursor->getPreviousDecl();
3284 // If we got to the end without finding OldFD, OldFD is the newer
3285 // declaration; leave things as they are.
3286 if (!Cursor) return;
3288 // If we do find OldFD, then NewFD is newer.
3289 if (Cursor == OldFD) break;
3291 // Otherwise, keep looking.
3297 void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
3298 ArrayRef<Expr *> Args, ADLResult &Result) {
3299 // Find all of the associated namespaces and classes based on the
3300 // arguments we have.
3301 AssociatedNamespaceSet AssociatedNamespaces;
3302 AssociatedClassSet AssociatedClasses;
3303 FindAssociatedClassesAndNamespaces(Loc, Args,
3304 AssociatedNamespaces,
3307 // C++ [basic.lookup.argdep]p3:
3308 // Let X be the lookup set produced by unqualified lookup (3.4.1)
3309 // and let Y be the lookup set produced by argument dependent
3310 // lookup (defined as follows). If X contains [...] then Y is
3311 // empty. Otherwise Y is the set of declarations found in the
3312 // namespaces associated with the argument types as described
3313 // below. The set of declarations found by the lookup of the name
3314 // is the union of X and Y.
3316 // Here, we compute Y and add its members to the overloaded
3318 for (auto *NS : AssociatedNamespaces) {
3319 // When considering an associated namespace, the lookup is the
3320 // same as the lookup performed when the associated namespace is
3321 // used as a qualifier (3.4.3.2) except that:
3323 // -- Any using-directives in the associated namespace are
3326 // -- Any namespace-scope friend functions declared in
3327 // associated classes are visible within their respective
3328 // namespaces even if they are not visible during an ordinary
3330 DeclContext::lookup_result R = NS->lookup(Name);
3332 // If the only declaration here is an ordinary friend, consider
3333 // it only if it was declared in an associated classes.
3334 if ((D->getIdentifierNamespace() & Decl::IDNS_Ordinary) == 0) {
3335 // If it's neither ordinarily visible nor a friend, we can't find it.
3336 if ((D->getIdentifierNamespace() & Decl::IDNS_OrdinaryFriend) == 0)
3339 bool DeclaredInAssociatedClass = false;
3340 for (Decl *DI = D; DI; DI = DI->getPreviousDecl()) {
3341 DeclContext *LexDC = DI->getLexicalDeclContext();
3342 if (isa<CXXRecordDecl>(LexDC) &&
3343 AssociatedClasses.count(cast<CXXRecordDecl>(LexDC)) &&
3344 isVisible(cast<NamedDecl>(DI))) {
3345 DeclaredInAssociatedClass = true;
3349 if (!DeclaredInAssociatedClass)
3353 auto *Underlying = D;
3354 if (auto *USD = dyn_cast<UsingShadowDecl>(D))
3355 Underlying = USD->getTargetDecl();
3357 if (!isa<FunctionDecl>(Underlying) &&
3358 !isa<FunctionTemplateDecl>(Underlying))
3361 if (!isVisible(D)) {
3362 D = findAcceptableDecl(*this, D);
3365 if (auto *USD = dyn_cast<UsingShadowDecl>(D))
3366 Underlying = USD->getTargetDecl();
3369 // FIXME: Preserve D as the FoundDecl.
3370 Result.insert(Underlying);
3375 //----------------------------------------------------------------------------
3376 // Search for all visible declarations.
3377 //----------------------------------------------------------------------------
3378 VisibleDeclConsumer::~VisibleDeclConsumer() { }
3380 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
3384 class ShadowContextRAII;
3386 class VisibleDeclsRecord {
3388 /// \brief An entry in the shadow map, which is optimized to store a
3389 /// single declaration (the common case) but can also store a list
3390 /// of declarations.
3391 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
3394 /// \brief A mapping from declaration names to the declarations that have
3395 /// this name within a particular scope.
3396 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
3398 /// \brief A list of shadow maps, which is used to model name hiding.
3399 std::list<ShadowMap> ShadowMaps;
3401 /// \brief The declaration contexts we have already visited.
3402 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
3404 friend class ShadowContextRAII;
3407 /// \brief Determine whether we have already visited this context
3408 /// (and, if not, note that we are going to visit that context now).
3409 bool visitedContext(DeclContext *Ctx) {
3410 return !VisitedContexts.insert(Ctx).second;
3413 bool alreadyVisitedContext(DeclContext *Ctx) {
3414 return VisitedContexts.count(Ctx);
3417 /// \brief Determine whether the given declaration is hidden in the
3420 /// \returns the declaration that hides the given declaration, or
3421 /// NULL if no such declaration exists.
3422 NamedDecl *checkHidden(NamedDecl *ND);
3424 /// \brief Add a declaration to the current shadow map.
3425 void add(NamedDecl *ND) {
3426 ShadowMaps.back()[ND->getDeclName()].push_back(ND);
3430 /// \brief RAII object that records when we've entered a shadow context.
3431 class ShadowContextRAII {
3432 VisibleDeclsRecord &Visible;
3434 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
3437 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
3438 Visible.ShadowMaps.emplace_back();
3441 ~ShadowContextRAII() {
3442 Visible.ShadowMaps.pop_back();
3446 } // end anonymous namespace
3448 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
3449 unsigned IDNS = ND->getIdentifierNamespace();
3450 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
3451 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
3452 SM != SMEnd; ++SM) {
3453 ShadowMap::iterator Pos = SM->find(ND->getDeclName());
3454 if (Pos == SM->end())
3457 for (auto *D : Pos->second) {
3458 // A tag declaration does not hide a non-tag declaration.
3459 if (D->hasTagIdentifierNamespace() &&
3460 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
3461 Decl::IDNS_ObjCProtocol)))
3464 // Protocols are in distinct namespaces from everything else.
3465 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
3466 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
3467 D->getIdentifierNamespace() != IDNS)
3470 // Functions and function templates in the same scope overload
3471 // rather than hide. FIXME: Look for hiding based on function
3473 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3474 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3475 SM == ShadowMaps.rbegin())
3478 // A shadow declaration that's created by a resolved using declaration
3479 // is not hidden by the same using declaration.
3480 if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) &&
3481 cast<UsingShadowDecl>(ND)->getUsingDecl() == D)
3484 // We've found a declaration that hides this one.
3492 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
3493 bool QualifiedNameLookup,
3495 VisibleDeclConsumer &Consumer,
3496 VisibleDeclsRecord &Visited,
3497 bool IncludeDependentBases = false) {
3501 // Make sure we don't visit the same context twice.
3502 if (Visited.visitedContext(Ctx->getPrimaryContext()))
3505 // Outside C++, lookup results for the TU live on identifiers.
3506 if (isa<TranslationUnitDecl>(Ctx) &&
3507 !Result.getSema().getLangOpts().CPlusPlus) {
3508 auto &S = Result.getSema();
3509 auto &Idents = S.Context.Idents;
3511 // Ensure all external identifiers are in the identifier table.
3512 if (IdentifierInfoLookup *External = Idents.getExternalIdentifierLookup()) {
3513 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
3514 for (StringRef Name = Iter->Next(); !Name.empty(); Name = Iter->Next())
3518 // Walk all lookup results in the TU for each identifier.
3519 for (const auto &Ident : Idents) {
3520 for (auto I = S.IdResolver.begin(Ident.getValue()),
3521 E = S.IdResolver.end();
3523 if (S.IdResolver.isDeclInScope(*I, Ctx)) {
3524 if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
3525 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3535 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
3536 Result.getSema().ForceDeclarationOfImplicitMembers(Class);
3538 // Enumerate all of the results in this context.
3539 for (DeclContextLookupResult R : Ctx->lookups()) {
3541 if (auto *ND = Result.getAcceptableDecl(D)) {
3542 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3548 // Traverse using directives for qualified name lookup.
3549 if (QualifiedNameLookup) {
3550 ShadowContextRAII Shadow(Visited);
3551 for (auto I : Ctx->using_directives()) {
3552 if (!Result.getSema().isVisible(I))
3554 LookupVisibleDecls(I->getNominatedNamespace(), Result,
3555 QualifiedNameLookup, InBaseClass, Consumer, Visited,
3556 IncludeDependentBases);
3560 // Traverse the contexts of inherited C++ classes.
3561 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
3562 if (!Record->hasDefinition())
3565 for (const auto &B : Record->bases()) {
3566 QualType BaseType = B.getType();
3569 if (BaseType->isDependentType()) {
3570 if (!IncludeDependentBases) {
3571 // Don't look into dependent bases, because name lookup can't look
3575 const auto *TST = BaseType->getAs<TemplateSpecializationType>();
3578 TemplateName TN = TST->getTemplateName();
3580 dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl());
3583 RD = TD->getTemplatedDecl();
3585 const auto *Record = BaseType->getAs<RecordType>();
3588 RD = Record->getDecl();
3591 // FIXME: It would be nice to be able to determine whether referencing
3592 // a particular member would be ambiguous. For example, given
3594 // struct A { int member; };
3595 // struct B { int member; };
3596 // struct C : A, B { };
3598 // void f(C *c) { c->### }
3600 // accessing 'member' would result in an ambiguity. However, we
3601 // could be smart enough to qualify the member with the base
3610 // Find results in this base class (and its bases).
3611 ShadowContextRAII Shadow(Visited);
3612 LookupVisibleDecls(RD, Result, QualifiedNameLookup, true, Consumer,
3613 Visited, IncludeDependentBases);
3617 // Traverse the contexts of Objective-C classes.
3618 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
3619 // Traverse categories.
3620 for (auto *Cat : IFace->visible_categories()) {
3621 ShadowContextRAII Shadow(Visited);
3622 LookupVisibleDecls(Cat, Result, QualifiedNameLookup, false,
3626 // Traverse protocols.
3627 for (auto *I : IFace->all_referenced_protocols()) {
3628 ShadowContextRAII Shadow(Visited);
3629 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3633 // Traverse the superclass.
3634 if (IFace->getSuperClass()) {
3635 ShadowContextRAII Shadow(Visited);
3636 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup,
3637 true, Consumer, Visited);
3640 // If there is an implementation, traverse it. We do this to find
3641 // synthesized ivars.
3642 if (IFace->getImplementation()) {
3643 ShadowContextRAII Shadow(Visited);
3644 LookupVisibleDecls(IFace->getImplementation(), Result,
3645 QualifiedNameLookup, InBaseClass, Consumer, Visited);
3647 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
3648 for (auto *I : Protocol->protocols()) {
3649 ShadowContextRAII Shadow(Visited);
3650 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3653 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
3654 for (auto *I : Category->protocols()) {
3655 ShadowContextRAII Shadow(Visited);
3656 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3660 // If there is an implementation, traverse it.
3661 if (Category->getImplementation()) {
3662 ShadowContextRAII Shadow(Visited);
3663 LookupVisibleDecls(Category->getImplementation(), Result,
3664 QualifiedNameLookup, true, Consumer, Visited);
3669 static void LookupVisibleDecls(Scope *S, LookupResult &Result,
3670 UnqualUsingDirectiveSet &UDirs,
3671 VisibleDeclConsumer &Consumer,
3672 VisibleDeclsRecord &Visited) {
3676 if (!S->getEntity() ||
3678 !Visited.alreadyVisitedContext(S->getEntity())) ||
3679 (S->getEntity())->isFunctionOrMethod()) {
3680 FindLocalExternScope FindLocals(Result);
3681 // Walk through the declarations in this Scope. The consumer might add new
3682 // decls to the scope as part of deserialization, so make a copy first.
3683 SmallVector<Decl *, 8> ScopeDecls(S->decls().begin(), S->decls().end());
3684 for (Decl *D : ScopeDecls) {
3685 if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
3686 if ((ND = Result.getAcceptableDecl(ND))) {
3687 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
3693 // FIXME: C++ [temp.local]p8
3694 DeclContext *Entity = nullptr;
3695 if (S->getEntity()) {
3696 // Look into this scope's declaration context, along with any of its
3697 // parent lookup contexts (e.g., enclosing classes), up to the point
3698 // where we hit the context stored in the next outer scope.
3699 Entity = S->getEntity();
3700 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME
3702 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
3703 Ctx = Ctx->getLookupParent()) {
3704 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
3705 if (Method->isInstanceMethod()) {
3706 // For instance methods, look for ivars in the method's interface.
3707 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
3708 Result.getNameLoc(), Sema::LookupMemberName);
3709 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
3710 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false,
3711 /*InBaseClass=*/false, Consumer, Visited);
3715 // We've already performed all of the name lookup that we need
3716 // to for Objective-C methods; the next context will be the
3721 if (Ctx->isFunctionOrMethod())
3724 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false,
3725 /*InBaseClass=*/false, Consumer, Visited);
3727 } else if (!S->getParent()) {
3728 // Look into the translation unit scope. We walk through the translation
3729 // unit's declaration context, because the Scope itself won't have all of
3730 // the declarations if we loaded a precompiled header.
3731 // FIXME: We would like the translation unit's Scope object to point to the
3732 // translation unit, so we don't need this special "if" branch. However,
3733 // doing so would force the normal C++ name-lookup code to look into the
3734 // translation unit decl when the IdentifierInfo chains would suffice.
3735 // Once we fix that problem (which is part of a more general "don't look
3736 // in DeclContexts unless we have to" optimization), we can eliminate this.
3737 Entity = Result.getSema().Context.getTranslationUnitDecl();
3738 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false,
3739 /*InBaseClass=*/false, Consumer, Visited);
3743 // Lookup visible declarations in any namespaces found by using
3745 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity))
3746 LookupVisibleDecls(const_cast<DeclContext *>(UUE.getNominatedNamespace()),
3747 Result, /*QualifiedNameLookup=*/false,
3748 /*InBaseClass=*/false, Consumer, Visited);
3751 // Lookup names in the parent scope.
3752 ShadowContextRAII Shadow(Visited);
3753 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited);
3756 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
3757 VisibleDeclConsumer &Consumer,
3758 bool IncludeGlobalScope) {
3759 // Determine the set of using directives available during
3760 // unqualified name lookup.
3762 UnqualUsingDirectiveSet UDirs(*this);
3763 if (getLangOpts().CPlusPlus) {
3764 // Find the first namespace or translation-unit scope.
3765 while (S && !isNamespaceOrTranslationUnitScope(S))
3768 UDirs.visitScopeChain(Initial, S);
3772 // Look for visible declarations.
3773 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3774 Result.setAllowHidden(Consumer.includeHiddenDecls());
3775 VisibleDeclsRecord Visited;
3776 if (!IncludeGlobalScope)
3777 Visited.visitedContext(Context.getTranslationUnitDecl());
3778 ShadowContextRAII Shadow(Visited);
3779 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited);
3782 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
3783 VisibleDeclConsumer &Consumer,
3784 bool IncludeGlobalScope,
3785 bool IncludeDependentBases) {
3786 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3787 Result.setAllowHidden(Consumer.includeHiddenDecls());
3788 VisibleDeclsRecord Visited;
3789 if (!IncludeGlobalScope)
3790 Visited.visitedContext(Context.getTranslationUnitDecl());
3791 ShadowContextRAII Shadow(Visited);
3792 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true,
3793 /*InBaseClass=*/false, Consumer, Visited,
3794 IncludeDependentBases);
3797 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name.
3798 /// If GnuLabelLoc is a valid source location, then this is a definition
3799 /// of an __label__ label name, otherwise it is a normal label definition
3801 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc,
3802 SourceLocation GnuLabelLoc) {
3803 // Do a lookup to see if we have a label with this name already.
3804 NamedDecl *Res = nullptr;
3806 if (GnuLabelLoc.isValid()) {
3807 // Local label definitions always shadow existing labels.
3808 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
3809 Scope *S = CurScope;
3810 PushOnScopeChains(Res, S, true);
3811 return cast<LabelDecl>(Res);
3814 // Not a GNU local label.
3815 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration);
3816 // If we found a label, check to see if it is in the same context as us.
3817 // When in a Block, we don't want to reuse a label in an enclosing function.
3818 if (Res && Res->getDeclContext() != CurContext)
3821 // If not forward referenced or defined already, create the backing decl.
3822 Res = LabelDecl::Create(Context, CurContext, Loc, II);
3823 Scope *S = CurScope->getFnParent();
3824 assert(S && "Not in a function?");
3825 PushOnScopeChains(Res, S, true);
3827 return cast<LabelDecl>(Res);
3830 //===----------------------------------------------------------------------===//
3832 //===----------------------------------------------------------------------===//
3834 static bool isCandidateViable(CorrectionCandidateCallback &CCC,
3835 TypoCorrection &Candidate) {
3836 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
3837 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
3840 static void LookupPotentialTypoResult(Sema &SemaRef,
3842 IdentifierInfo *Name,
3843 Scope *S, CXXScopeSpec *SS,
3844 DeclContext *MemberContext,
3845 bool EnteringContext,
3846 bool isObjCIvarLookup,
3849 /// \brief Check whether the declarations found for a typo correction are
3850 /// visible. Set the correction's RequiresImport flag to true if none of the
3851 /// declarations are visible, false otherwise.
3852 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
3853 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
3855 for (/**/; DI != DE; ++DI)
3856 if (!LookupResult::isVisible(SemaRef, *DI))
3858 // No filtering needed if all decls are visible.
3860 TC.setRequiresImport(false);
3864 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
3865 bool AnyVisibleDecls = !NewDecls.empty();
3867 for (/**/; DI != DE; ++DI) {
3868 NamedDecl *VisibleDecl = *DI;
3869 if (!LookupResult::isVisible(SemaRef, *DI))
3870 VisibleDecl = findAcceptableDecl(SemaRef, *DI);
3873 if (!AnyVisibleDecls) {
3874 // Found a visible decl, discard all hidden ones.
3875 AnyVisibleDecls = true;
3878 NewDecls.push_back(VisibleDecl);
3879 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
3880 NewDecls.push_back(*DI);
3883 if (NewDecls.empty())
3884 TC = TypoCorrection();
3886 TC.setCorrectionDecls(NewDecls);
3887 TC.setRequiresImport(!AnyVisibleDecls);
3891 // Fill the supplied vector with the IdentifierInfo pointers for each piece of
3892 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
3893 // fill the vector with the IdentifierInfo pointers for "foo" and "bar").
3894 static void getNestedNameSpecifierIdentifiers(
3895 NestedNameSpecifier *NNS,
3896 SmallVectorImpl<const IdentifierInfo*> &Identifiers) {
3897 if (NestedNameSpecifier *Prefix = NNS->getPrefix())
3898 getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
3900 Identifiers.clear();
3902 const IdentifierInfo *II = nullptr;
3904 switch (NNS->getKind()) {
3905 case NestedNameSpecifier::Identifier:
3906 II = NNS->getAsIdentifier();
3909 case NestedNameSpecifier::Namespace:
3910 if (NNS->getAsNamespace()->isAnonymousNamespace())
3912 II = NNS->getAsNamespace()->getIdentifier();
3915 case NestedNameSpecifier::NamespaceAlias:
3916 II = NNS->getAsNamespaceAlias()->getIdentifier();
3919 case NestedNameSpecifier::TypeSpecWithTemplate:
3920 case NestedNameSpecifier::TypeSpec:
3921 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier();
3924 case NestedNameSpecifier::Global:
3925 case NestedNameSpecifier::Super:
3930 Identifiers.push_back(II);
3933 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
3934 DeclContext *Ctx, bool InBaseClass) {
3935 // Don't consider hidden names for typo correction.
3939 // Only consider entities with identifiers for names, ignoring
3940 // special names (constructors, overloaded operators, selectors,
3942 IdentifierInfo *Name = ND->getIdentifier();
3946 // Only consider visible declarations and declarations from modules with
3947 // names that exactly match.
3948 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo &&
3949 !findAcceptableDecl(SemaRef, ND))
3952 FoundName(Name->getName());
3955 void TypoCorrectionConsumer::FoundName(StringRef Name) {
3956 // Compute the edit distance between the typo and the name of this
3957 // entity, and add the identifier to the list of results.
3958 addName(Name, nullptr);
3961 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) {
3962 // Compute the edit distance between the typo and this keyword,
3963 // and add the keyword to the list of results.
3964 addName(Keyword, nullptr, nullptr, true);
3967 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
3968 NestedNameSpecifier *NNS, bool isKeyword) {
3969 // Use a simple length-based heuristic to determine the minimum possible
3970 // edit distance. If the minimum isn't good enough, bail out early.
3971 StringRef TypoStr = Typo->getName();
3972 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
3973 if (MinED && TypoStr.size() / MinED < 3)
3976 // Compute an upper bound on the allowable edit distance, so that the
3977 // edit-distance algorithm can short-circuit.
3978 unsigned UpperBound = (TypoStr.size() + 2) / 3 + 1;
3979 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
3980 if (ED >= UpperBound) return;
3982 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
3983 if (isKeyword) TC.makeKeyword();
3984 TC.setCorrectionRange(nullptr, Result.getLookupNameInfo());
3988 static const unsigned MaxTypoDistanceResultSets = 5;
3990 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) {
3991 StringRef TypoStr = Typo->getName();
3992 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
3994 // For very short typos, ignore potential corrections that have a different
3995 // base identifier from the typo or which have a normalized edit distance
3996 // longer than the typo itself.
3997 if (TypoStr.size() < 3 &&
3998 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
4001 // If the correction is resolved but is not viable, ignore it.
4002 if (Correction.isResolved()) {
4003 checkCorrectionVisibility(SemaRef, Correction);
4004 if (!Correction || !isCandidateViable(*CorrectionValidator, Correction))
4008 TypoResultList &CList =
4009 CorrectionResults[Correction.getEditDistance(false)][Name];
4011 if (!CList.empty() && !CList.back().isResolved())
4013 if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
4014 std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts());
4015 for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end();
4016 RI != RIEnd; ++RI) {
4017 // If the Correction refers to a decl already in the result list,
4018 // replace the existing result if the string representation of Correction
4019 // comes before the current result alphabetically, then stop as there is
4020 // nothing more to be done to add Correction to the candidate set.
4021 if (RI->getCorrectionDecl() == NewND) {
4022 if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts()))
4028 if (CList.empty() || Correction.isResolved())
4029 CList.push_back(Correction);
4031 while (CorrectionResults.size() > MaxTypoDistanceResultSets)
4032 CorrectionResults.erase(std::prev(CorrectionResults.end()));
4035 void TypoCorrectionConsumer::addNamespaces(
4036 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
4037 SearchNamespaces = true;
4039 for (auto KNPair : KnownNamespaces)
4040 Namespaces.addNameSpecifier(KNPair.first);
4042 bool SSIsTemplate = false;
4043 if (NestedNameSpecifier *NNS =
4044 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) {
4045 if (const Type *T = NNS->getAsType())
4046 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization;
4048 // Do not transform this into an iterator-based loop. The loop body can
4049 // trigger the creation of further types (through lazy deserialization) and
4050 // invalide iterators into this list.
4051 auto &Types = SemaRef.getASTContext().getTypes();
4052 for (unsigned I = 0; I != Types.size(); ++I) {
4053 const auto *TI = Types[I];
4054 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
4055 CD = CD->getCanonicalDecl();
4056 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
4057 !CD->isUnion() && CD->getIdentifier() &&
4058 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
4059 (CD->isBeingDefined() || CD->isCompleteDefinition()))
4060 Namespaces.addNameSpecifier(CD);
4065 const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() {
4066 if (++CurrentTCIndex < ValidatedCorrections.size())
4067 return ValidatedCorrections[CurrentTCIndex];
4069 CurrentTCIndex = ValidatedCorrections.size();
4070 while (!CorrectionResults.empty()) {
4071 auto DI = CorrectionResults.begin();
4072 if (DI->second.empty()) {
4073 CorrectionResults.erase(DI);
4077 auto RI = DI->second.begin();
4078 if (RI->second.empty()) {
4079 DI->second.erase(RI);
4080 performQualifiedLookups();
4084 TypoCorrection TC = RI->second.pop_back_val();
4085 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) {
4086 ValidatedCorrections.push_back(TC);
4087 return ValidatedCorrections[CurrentTCIndex];
4090 return ValidatedCorrections[0]; // The empty correction.
4093 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
4094 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
4095 DeclContext *TempMemberContext = MemberContext;
4096 CXXScopeSpec *TempSS = SS.get();
4098 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
4100 CorrectionValidator->IsObjCIvarLookup,
4101 Name == Typo && !Candidate.WillReplaceSpecifier());
4102 switch (Result.getResultKind()) {
4103 case LookupResult::NotFound:
4104 case LookupResult::NotFoundInCurrentInstantiation:
4105 case LookupResult::FoundUnresolvedValue:
4107 // Immediately retry the lookup without the given CXXScopeSpec
4109 Candidate.WillReplaceSpecifier(true);
4112 if (TempMemberContext) {
4115 TempMemberContext = nullptr;
4118 if (SearchNamespaces)
4119 QualifiedResults.push_back(Candidate);
4122 case LookupResult::Ambiguous:
4123 // We don't deal with ambiguities.
4126 case LookupResult::Found:
4127 case LookupResult::FoundOverloaded:
4128 // Store all of the Decls for overloaded symbols
4129 for (auto *TRD : Result)
4130 Candidate.addCorrectionDecl(TRD);
4131 checkCorrectionVisibility(SemaRef, Candidate);
4132 if (!isCandidateViable(*CorrectionValidator, Candidate)) {
4133 if (SearchNamespaces)
4134 QualifiedResults.push_back(Candidate);
4137 Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4143 void TypoCorrectionConsumer::performQualifiedLookups() {
4144 unsigned TypoLen = Typo->getName().size();
4145 for (const TypoCorrection &QR : QualifiedResults) {
4146 for (const auto &NSI : Namespaces) {
4147 DeclContext *Ctx = NSI.DeclCtx;
4148 const Type *NSType = NSI.NameSpecifier->getAsType();
4150 // If the current NestedNameSpecifier refers to a class and the
4151 // current correction candidate is the name of that class, then skip
4152 // it as it is unlikely a qualified version of the class' constructor
4153 // is an appropriate correction.
4154 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() :
4156 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
4160 TypoCorrection TC(QR);
4161 TC.ClearCorrectionDecls();
4162 TC.setCorrectionSpecifier(NSI.NameSpecifier);
4163 TC.setQualifierDistance(NSI.EditDistance);
4164 TC.setCallbackDistance(0); // Reset the callback distance
4166 // If the current correction candidate and namespace combination are
4167 // too far away from the original typo based on the normalized edit
4168 // distance, then skip performing a qualified name lookup.
4169 unsigned TmpED = TC.getEditDistance(true);
4170 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4171 TypoLen / TmpED < 3)
4175 Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4176 if (!SemaRef.LookupQualifiedName(Result, Ctx))
4179 // Any corrections added below will be validated in subsequent
4180 // iterations of the main while() loop over the Consumer's contents.
4181 switch (Result.getResultKind()) {
4182 case LookupResult::Found:
4183 case LookupResult::FoundOverloaded: {
4184 if (SS && SS->isValid()) {
4185 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
4186 std::string OldQualified;
4187 llvm::raw_string_ostream OldOStream(OldQualified);
4188 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy());
4189 OldOStream << Typo->getName();
4190 // If correction candidate would be an identical written qualified
4191 // identifer, then the existing CXXScopeSpec probably included a
4192 // typedef that didn't get accounted for properly.
4193 if (OldOStream.str() == NewQualified)
4196 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4197 TRD != TRDEnd; ++TRD) {
4198 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
4199 NSType ? NSType->getAsCXXRecordDecl()
4201 TRD.getPair()) == Sema::AR_accessible)
4202 TC.addCorrectionDecl(*TRD);
4204 if (TC.isResolved()) {
4205 TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4210 case LookupResult::NotFound:
4211 case LookupResult::NotFoundInCurrentInstantiation:
4212 case LookupResult::Ambiguous:
4213 case LookupResult::FoundUnresolvedValue:
4218 QualifiedResults.clear();
4221 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4222 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4223 : Context(Context), CurContextChain(buildContextChain(CurContext)) {
4224 if (NestedNameSpecifier *NNS =
4225 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) {
4226 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4227 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4229 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
4231 // Build the list of identifiers that would be used for an absolute
4232 // (from the global context) NestedNameSpecifier referring to the current
4234 for (DeclContext *C : llvm::reverse(CurContextChain)) {
4235 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C))
4236 CurContextIdentifiers.push_back(ND->getIdentifier());
4239 // Add the global context as a NestedNameSpecifier
4240 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
4241 NestedNameSpecifier::GlobalSpecifier(Context), 1};
4242 DistanceMap[1].push_back(SI);
4245 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
4246 DeclContext *Start) -> DeclContextList {
4247 assert(Start && "Building a context chain from a null context");
4248 DeclContextList Chain;
4249 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
4250 DC = DC->getLookupParent()) {
4251 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
4252 if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
4253 !(ND && ND->isAnonymousNamespace()))
4254 Chain.push_back(DC->getPrimaryContext());
4260 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
4261 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) {
4262 unsigned NumSpecifiers = 0;
4263 for (DeclContext *C : llvm::reverse(DeclChain)) {
4264 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) {
4265 NNS = NestedNameSpecifier::Create(Context, NNS, ND);
4267 } else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) {
4268 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(),
4269 RD->getTypeForDecl());
4273 return NumSpecifiers;
4276 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
4278 NestedNameSpecifier *NNS = nullptr;
4279 unsigned NumSpecifiers = 0;
4280 DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
4281 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
4283 // Eliminate common elements from the two DeclContext chains.
4284 for (DeclContext *C : llvm::reverse(CurContextChain)) {
4285 if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C)
4287 NamespaceDeclChain.pop_back();
4290 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
4291 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
4293 // Add an explicit leading '::' specifier if needed.
4294 if (NamespaceDeclChain.empty()) {
4295 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4296 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4298 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4299 } else if (NamedDecl *ND =
4300 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
4301 IdentifierInfo *Name = ND->getIdentifier();
4302 bool SameNameSpecifier = false;
4303 if (std::find(CurNameSpecifierIdentifiers.begin(),
4304 CurNameSpecifierIdentifiers.end(),
4305 Name) != CurNameSpecifierIdentifiers.end()) {
4306 std::string NewNameSpecifier;
4307 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
4308 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
4309 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4310 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4311 SpecifierOStream.flush();
4312 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
4314 if (SameNameSpecifier ||
4315 std::find(CurContextIdentifiers.begin(), CurContextIdentifiers.end(),
4316 Name) != CurContextIdentifiers.end()) {
4317 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4318 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4320 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4324 // If the built NestedNameSpecifier would be replacing an existing
4325 // NestedNameSpecifier, use the number of component identifiers that
4326 // would need to be changed as the edit distance instead of the number
4327 // of components in the built NestedNameSpecifier.
4328 if (NNS && !CurNameSpecifierIdentifiers.empty()) {
4329 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
4330 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4331 NumSpecifiers = llvm::ComputeEditDistance(
4332 llvm::makeArrayRef(CurNameSpecifierIdentifiers),
4333 llvm::makeArrayRef(NewNameSpecifierIdentifiers));
4336 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
4337 DistanceMap[NumSpecifiers].push_back(SI);
4340 /// \brief Perform name lookup for a possible result for typo correction.
4341 static void LookupPotentialTypoResult(Sema &SemaRef,
4343 IdentifierInfo *Name,
4344 Scope *S, CXXScopeSpec *SS,
4345 DeclContext *MemberContext,
4346 bool EnteringContext,
4347 bool isObjCIvarLookup,
4349 Res.suppressDiagnostics();
4351 Res.setLookupName(Name);
4352 Res.setAllowHidden(FindHidden);
4353 if (MemberContext) {
4354 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
4355 if (isObjCIvarLookup) {
4356 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
4363 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(
4364 Name, ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
4371 SemaRef.LookupQualifiedName(Res, MemberContext);
4375 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
4378 // Fake ivar lookup; this should really be part of
4379 // LookupParsedName.
4380 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
4381 if (Method->isInstanceMethod() && Method->getClassInterface() &&
4383 (Res.isSingleResult() &&
4384 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) {
4385 if (ObjCIvarDecl *IV
4386 = Method->getClassInterface()->lookupInstanceVariable(Name)) {
4394 /// \brief Add keywords to the consumer as possible typo corrections.
4395 static void AddKeywordsToConsumer(Sema &SemaRef,
4396 TypoCorrectionConsumer &Consumer,
4397 Scope *S, CorrectionCandidateCallback &CCC,
4398 bool AfterNestedNameSpecifier) {
4399 if (AfterNestedNameSpecifier) {
4400 // For 'X::', we know exactly which keywords can appear next.
4401 Consumer.addKeywordResult("template");
4402 if (CCC.WantExpressionKeywords)
4403 Consumer.addKeywordResult("operator");
4407 if (CCC.WantObjCSuper)
4408 Consumer.addKeywordResult("super");
4410 if (CCC.WantTypeSpecifiers) {
4411 // Add type-specifier keywords to the set of results.
4412 static const char *const CTypeSpecs[] = {
4413 "char", "const", "double", "enum", "float", "int", "long", "short",
4414 "signed", "struct", "union", "unsigned", "void", "volatile",
4415 "_Complex", "_Imaginary",
4416 // storage-specifiers as well
4417 "extern", "inline", "static", "typedef"
4420 const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs);
4421 for (unsigned I = 0; I != NumCTypeSpecs; ++I)
4422 Consumer.addKeywordResult(CTypeSpecs[I]);
4424 if (SemaRef.getLangOpts().C99)
4425 Consumer.addKeywordResult("restrict");
4426 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
4427 Consumer.addKeywordResult("bool");
4428 else if (SemaRef.getLangOpts().C99)
4429 Consumer.addKeywordResult("_Bool");
4431 if (SemaRef.getLangOpts().CPlusPlus) {
4432 Consumer.addKeywordResult("class");
4433 Consumer.addKeywordResult("typename");
4434 Consumer.addKeywordResult("wchar_t");
4436 if (SemaRef.getLangOpts().CPlusPlus11) {
4437 Consumer.addKeywordResult("char16_t");
4438 Consumer.addKeywordResult("char32_t");
4439 Consumer.addKeywordResult("constexpr");
4440 Consumer.addKeywordResult("decltype");
4441 Consumer.addKeywordResult("thread_local");
4445 if (SemaRef.getLangOpts().GNUMode)
4446 Consumer.addKeywordResult("typeof");
4447 } else if (CCC.WantFunctionLikeCasts) {
4448 static const char *const CastableTypeSpecs[] = {
4449 "char", "double", "float", "int", "long", "short",
4450 "signed", "unsigned", "void"
4452 for (auto *kw : CastableTypeSpecs)
4453 Consumer.addKeywordResult(kw);
4456 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
4457 Consumer.addKeywordResult("const_cast");
4458 Consumer.addKeywordResult("dynamic_cast");
4459 Consumer.addKeywordResult("reinterpret_cast");
4460 Consumer.addKeywordResult("static_cast");
4463 if (CCC.WantExpressionKeywords) {
4464 Consumer.addKeywordResult("sizeof");
4465 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
4466 Consumer.addKeywordResult("false");
4467 Consumer.addKeywordResult("true");
4470 if (SemaRef.getLangOpts().CPlusPlus) {
4471 static const char *const CXXExprs[] = {
4472 "delete", "new", "operator", "throw", "typeid"
4474 const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs);
4475 for (unsigned I = 0; I != NumCXXExprs; ++I)
4476 Consumer.addKeywordResult(CXXExprs[I]);
4478 if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
4479 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
4480 Consumer.addKeywordResult("this");
4482 if (SemaRef.getLangOpts().CPlusPlus11) {
4483 Consumer.addKeywordResult("alignof");
4484 Consumer.addKeywordResult("nullptr");
4488 if (SemaRef.getLangOpts().C11) {
4489 // FIXME: We should not suggest _Alignof if the alignof macro
4491 Consumer.addKeywordResult("_Alignof");
4495 if (CCC.WantRemainingKeywords) {
4496 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
4498 static const char *const CStmts[] = {
4499 "do", "else", "for", "goto", "if", "return", "switch", "while" };
4500 const unsigned NumCStmts = llvm::array_lengthof(CStmts);
4501 for (unsigned I = 0; I != NumCStmts; ++I)
4502 Consumer.addKeywordResult(CStmts[I]);
4504 if (SemaRef.getLangOpts().CPlusPlus) {
4505 Consumer.addKeywordResult("catch");
4506 Consumer.addKeywordResult("try");
4509 if (S && S->getBreakParent())
4510 Consumer.addKeywordResult("break");
4512 if (S && S->getContinueParent())
4513 Consumer.addKeywordResult("continue");
4515 if (!SemaRef.getCurFunction()->SwitchStack.empty()) {
4516 Consumer.addKeywordResult("case");
4517 Consumer.addKeywordResult("default");
4520 if (SemaRef.getLangOpts().CPlusPlus) {
4521 Consumer.addKeywordResult("namespace");
4522 Consumer.addKeywordResult("template");
4525 if (S && S->isClassScope()) {
4526 Consumer.addKeywordResult("explicit");
4527 Consumer.addKeywordResult("friend");
4528 Consumer.addKeywordResult("mutable");
4529 Consumer.addKeywordResult("private");
4530 Consumer.addKeywordResult("protected");
4531 Consumer.addKeywordResult("public");
4532 Consumer.addKeywordResult("virtual");
4536 if (SemaRef.getLangOpts().CPlusPlus) {
4537 Consumer.addKeywordResult("using");
4539 if (SemaRef.getLangOpts().CPlusPlus11)
4540 Consumer.addKeywordResult("static_assert");
4545 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
4546 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4547 Scope *S, CXXScopeSpec *SS,
4548 std::unique_ptr<CorrectionCandidateCallback> CCC,
4549 DeclContext *MemberContext, bool EnteringContext,
4550 const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
4552 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
4553 DisableTypoCorrection)
4556 // In Microsoft mode, don't perform typo correction in a template member
4557 // function dependent context because it interferes with the "lookup into
4558 // dependent bases of class templates" feature.
4559 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
4560 isa<CXXMethodDecl>(CurContext))
4563 // We only attempt to correct typos for identifiers.
4564 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4568 // If the scope specifier itself was invalid, don't try to correct
4570 if (SS && SS->isInvalid())
4573 // Never try to correct typos during any kind of code synthesis.
4574 if (!CodeSynthesisContexts.empty())
4577 // Don't try to correct 'super'.
4578 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
4581 // Abort if typo correction already failed for this specific typo.
4582 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
4583 if (locs != TypoCorrectionFailures.end() &&
4584 locs->second.count(TypoName.getLoc()))
4587 // Don't try to correct the identifier "vector" when in AltiVec mode.
4588 // TODO: Figure out why typo correction misbehaves in this case, fix it, and
4589 // remove this workaround.
4590 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector"))
4593 // Provide a stop gap for files that are just seriously broken. Trying
4594 // to correct all typos can turn into a HUGE performance penalty, causing
4595 // some files to take minutes to get rejected by the parser.
4596 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
4597 if (Limit && TyposCorrected >= Limit)
4601 // If we're handling a missing symbol error, using modules, and the
4602 // special search all modules option is used, look for a missing import.
4603 if (ErrorRecovery && getLangOpts().Modules &&
4604 getLangOpts().ModulesSearchAll) {
4605 // The following has the side effect of loading the missing module.
4606 getModuleLoader().lookupMissingImports(Typo->getName(),
4607 TypoName.getLocStart());
4610 CorrectionCandidateCallback &CCCRef = *CCC;
4611 auto Consumer = llvm::make_unique<TypoCorrectionConsumer>(
4612 *this, TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4615 // Perform name lookup to find visible, similarly-named entities.
4616 bool IsUnqualifiedLookup = false;
4617 DeclContext *QualifiedDC = MemberContext;
4618 if (MemberContext) {
4619 LookupVisibleDecls(MemberContext, LookupKind, *Consumer);
4621 // Look in qualified interfaces.
4623 for (auto *I : OPT->quals())
4624 LookupVisibleDecls(I, LookupKind, *Consumer);
4626 } else if (SS && SS->isSet()) {
4627 QualifiedDC = computeDeclContext(*SS, EnteringContext);
4631 LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer);
4633 IsUnqualifiedLookup = true;
4636 // Determine whether we are going to search in the various namespaces for
4638 bool SearchNamespaces
4639 = getLangOpts().CPlusPlus &&
4640 (IsUnqualifiedLookup || (SS && SS->isSet()));
4642 if (IsUnqualifiedLookup || SearchNamespaces) {
4643 // For unqualified lookup, look through all of the names that we have
4644 // seen in this translation unit.
4645 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4646 for (const auto &I : Context.Idents)
4647 Consumer->FoundName(I.getKey());
4649 // Walk through identifiers in external identifier sources.
4650 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4651 if (IdentifierInfoLookup *External
4652 = Context.Idents.getExternalIdentifierLookup()) {
4653 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4655 StringRef Name = Iter->Next();
4659 Consumer->FoundName(Name);
4664 AddKeywordsToConsumer(*this, *Consumer, S, CCCRef, SS && SS->isNotEmpty());
4666 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
4667 // to search those namespaces.
4668 if (SearchNamespaces) {
4669 // Load any externally-known namespaces.
4670 if (ExternalSource && !LoadedExternalKnownNamespaces) {
4671 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
4672 LoadedExternalKnownNamespaces = true;
4673 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
4674 for (auto *N : ExternalKnownNamespaces)
4675 KnownNamespaces[N] = true;
4678 Consumer->addNamespaces(KnownNamespaces);
4684 /// \brief Try to "correct" a typo in the source code by finding
4685 /// visible declarations whose names are similar to the name that was
4686 /// present in the source code.
4688 /// \param TypoName the \c DeclarationNameInfo structure that contains
4689 /// the name that was present in the source code along with its location.
4691 /// \param LookupKind the name-lookup criteria used to search for the name.
4693 /// \param S the scope in which name lookup occurs.
4695 /// \param SS the nested-name-specifier that precedes the name we're
4696 /// looking for, if present.
4698 /// \param CCC A CorrectionCandidateCallback object that provides further
4699 /// validation of typo correction candidates. It also provides flags for
4700 /// determining the set of keywords permitted.
4702 /// \param MemberContext if non-NULL, the context in which to look for
4703 /// a member access expression.
4705 /// \param EnteringContext whether we're entering the context described by
4706 /// the nested-name-specifier SS.
4708 /// \param OPT when non-NULL, the search for visible declarations will
4709 /// also walk the protocols in the qualified interfaces of \p OPT.
4711 /// \returns a \c TypoCorrection containing the corrected name if the typo
4712 /// along with information such as the \c NamedDecl where the corrected name
4713 /// was declared, and any additional \c NestedNameSpecifier needed to access
4714 /// it (C++ only). The \c TypoCorrection is empty if there is no correction.
4715 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
4716 Sema::LookupNameKind LookupKind,
4717 Scope *S, CXXScopeSpec *SS,
4718 std::unique_ptr<CorrectionCandidateCallback> CCC,
4719 CorrectTypoKind Mode,
4720 DeclContext *MemberContext,
4721 bool EnteringContext,
4722 const ObjCObjectPointerType *OPT,
4723 bool RecordFailure) {
4724 assert(CCC && "CorrectTypo requires a CorrectionCandidateCallback");
4726 // Always let the ExternalSource have the first chance at correction, even
4727 // if we would otherwise have given up.
4728 if (ExternalSource) {
4729 if (TypoCorrection Correction = ExternalSource->CorrectTypo(
4730 TypoName, LookupKind, S, SS, *CCC, MemberContext, EnteringContext, OPT))
4734 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
4735 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
4736 // some instances of CTC_Unknown, while WantRemainingKeywords is true
4737 // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
4738 bool ObjCMessageReceiver = CCC->WantObjCSuper && !CCC->WantRemainingKeywords;
4740 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4741 auto Consumer = makeTypoCorrectionConsumer(
4742 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4743 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4746 return TypoCorrection();
4748 // If we haven't found anything, we're done.
4749 if (Consumer->empty())
4750 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4752 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4753 // is not more that about a third of the length of the typo's identifier.
4754 unsigned ED = Consumer->getBestEditDistance(true);
4755 unsigned TypoLen = Typo->getName().size();
4756 if (ED > 0 && TypoLen / ED < 3)
4757 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4759 TypoCorrection BestTC = Consumer->getNextCorrection();
4760 TypoCorrection SecondBestTC = Consumer->getNextCorrection();
4762 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4764 ED = BestTC.getEditDistance();
4766 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
4767 // If this was an unqualified lookup and we believe the callback
4768 // object wouldn't have filtered out possible corrections, note
4769 // that no correction was found.
4770 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4773 // If only a single name remains, return that result.
4774 if (!SecondBestTC ||
4775 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
4776 const TypoCorrection &Result = BestTC;
4778 // Don't correct to a keyword that's the same as the typo; the keyword
4779 // wasn't actually in scope.
4780 if (ED == 0 && Result.isKeyword())
4781 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4783 TypoCorrection TC = Result;
4784 TC.setCorrectionRange(SS, TypoName);
4785 checkCorrectionVisibility(*this, TC);
4787 } else if (SecondBestTC && ObjCMessageReceiver) {
4788 // Prefer 'super' when we're completing in a message-receiver
4791 if (BestTC.getCorrection().getAsString() != "super") {
4792 if (SecondBestTC.getCorrection().getAsString() == "super")
4793 BestTC = SecondBestTC;
4794 else if ((*Consumer)["super"].front().isKeyword())
4795 BestTC = (*Consumer)["super"].front();
4797 // Don't correct to a keyword that's the same as the typo; the keyword
4798 // wasn't actually in scope.
4799 if (BestTC.getEditDistance() == 0 ||
4800 BestTC.getCorrection().getAsString() != "super")
4801 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4803 BestTC.setCorrectionRange(SS, TypoName);
4807 // Record the failure's location if needed and return an empty correction. If
4808 // this was an unqualified lookup and we believe the callback object did not
4809 // filter out possible corrections, also cache the failure for the typo.
4810 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC);
4813 /// \brief Try to "correct" a typo in the source code by finding
4814 /// visible declarations whose names are similar to the name that was
4815 /// present in the source code.
4817 /// \param TypoName the \c DeclarationNameInfo structure that contains
4818 /// the name that was present in the source code along with its location.
4820 /// \param LookupKind the name-lookup criteria used to search for the name.
4822 /// \param S the scope in which name lookup occurs.
4824 /// \param SS the nested-name-specifier that precedes the name we're
4825 /// looking for, if present.
4827 /// \param CCC A CorrectionCandidateCallback object that provides further
4828 /// validation of typo correction candidates. It also provides flags for
4829 /// determining the set of keywords permitted.
4831 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print
4832 /// diagnostics when the actual typo correction is attempted.
4834 /// \param TRC A TypoRecoveryCallback functor that will be used to build an
4835 /// Expr from a typo correction candidate.
4837 /// \param MemberContext if non-NULL, the context in which to look for
4838 /// a member access expression.
4840 /// \param EnteringContext whether we're entering the context described by
4841 /// the nested-name-specifier SS.
4843 /// \param OPT when non-NULL, the search for visible declarations will
4844 /// also walk the protocols in the qualified interfaces of \p OPT.
4846 /// \returns a new \c TypoExpr that will later be replaced in the AST with an
4847 /// Expr representing the result of performing typo correction, or nullptr if
4848 /// typo correction is not possible. If nullptr is returned, no diagnostics will
4849 /// be emitted and it is the responsibility of the caller to emit any that are
4851 TypoExpr *Sema::CorrectTypoDelayed(
4852 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4853 Scope *S, CXXScopeSpec *SS,
4854 std::unique_ptr<CorrectionCandidateCallback> CCC,
4855 TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode,
4856 DeclContext *MemberContext, bool EnteringContext,
4857 const ObjCObjectPointerType *OPT) {
4858 assert(CCC && "CorrectTypoDelayed requires a CorrectionCandidateCallback");
4860 auto Consumer = makeTypoCorrectionConsumer(
4861 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4862 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4864 // Give the external sema source a chance to correct the typo.
4865 TypoCorrection ExternalTypo;
4866 if (ExternalSource && Consumer) {
4867 ExternalTypo = ExternalSource->CorrectTypo(
4868 TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(),
4869 MemberContext, EnteringContext, OPT);
4871 Consumer->addCorrection(ExternalTypo);
4874 if (!Consumer || Consumer->empty())
4877 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4878 // is not more that about a third of the length of the typo's identifier.
4879 unsigned ED = Consumer->getBestEditDistance(true);
4880 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4881 if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3)
4884 ExprEvalContexts.back().NumTypos++;
4885 return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC));
4888 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) {
4892 CorrectionDecls.clear();
4894 CorrectionDecls.push_back(CDecl);
4896 if (!CorrectionName)
4897 CorrectionName = CDecl->getDeclName();
4900 std::string TypoCorrection::getAsString(const LangOptions &LO) const {
4901 if (CorrectionNameSpec) {
4902 std::string tmpBuffer;
4903 llvm::raw_string_ostream PrefixOStream(tmpBuffer);
4904 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO));
4905 PrefixOStream << CorrectionName;
4906 return PrefixOStream.str();
4909 return CorrectionName.getAsString();
4912 bool CorrectionCandidateCallback::ValidateCandidate(
4913 const TypoCorrection &candidate) {
4914 if (!candidate.isResolved())
4917 if (candidate.isKeyword())
4918 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
4919 WantRemainingKeywords || WantObjCSuper;
4921 bool HasNonType = false;
4922 bool HasStaticMethod = false;
4923 bool HasNonStaticMethod = false;
4924 for (Decl *D : candidate) {
4925 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
4926 D = FTD->getTemplatedDecl();
4927 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
4928 if (Method->isStatic())
4929 HasStaticMethod = true;
4931 HasNonStaticMethod = true;
4933 if (!isa<TypeDecl>(D))
4937 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
4938 !candidate.getCorrectionSpecifier())
4941 return WantTypeSpecifiers || HasNonType;
4944 FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs,
4945 bool HasExplicitTemplateArgs,
4947 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
4948 CurContext(SemaRef.CurContext), MemberFn(ME) {
4949 WantTypeSpecifiers = false;
4950 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && NumArgs == 1;
4951 WantRemainingKeywords = false;
4954 bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) {
4955 if (!candidate.getCorrectionDecl())
4956 return candidate.isKeyword();
4958 for (auto *C : candidate) {
4959 FunctionDecl *FD = nullptr;
4960 NamedDecl *ND = C->getUnderlyingDecl();
4961 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
4962 FD = FTD->getTemplatedDecl();
4963 if (!HasExplicitTemplateArgs && !FD) {
4964 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
4965 // If the Decl is neither a function nor a template function,
4966 // determine if it is a pointer or reference to a function. If so,
4967 // check against the number of arguments expected for the pointee.
4968 QualType ValType = cast<ValueDecl>(ND)->getType();
4969 if (ValType->isAnyPointerType() || ValType->isReferenceType())
4970 ValType = ValType->getPointeeType();
4971 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
4972 if (FPT->getNumParams() == NumArgs)
4977 // Skip the current candidate if it is not a FunctionDecl or does not accept
4978 // the current number of arguments.
4979 if (!FD || !(FD->getNumParams() >= NumArgs &&
4980 FD->getMinRequiredArguments() <= NumArgs))
4983 // If the current candidate is a non-static C++ method, skip the candidate
4984 // unless the method being corrected--or the current DeclContext, if the
4985 // function being corrected is not a method--is a method in the same class
4986 // or a descendent class of the candidate's parent class.
4987 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
4988 if (MemberFn || !MD->isStatic()) {
4989 CXXMethodDecl *CurMD =
4991 ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl())
4992 : dyn_cast_or_null<CXXMethodDecl>(CurContext);
4993 CXXRecordDecl *CurRD =
4994 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
4995 CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
4996 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
5005 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5006 const PartialDiagnostic &TypoDiag,
5007 bool ErrorRecovery) {
5008 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
5012 /// Find which declaration we should import to provide the definition of
5013 /// the given declaration.
5014 static NamedDecl *getDefinitionToImport(NamedDecl *D) {
5015 if (VarDecl *VD = dyn_cast<VarDecl>(D))
5016 return VD->getDefinition();
5017 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
5018 return FD->getDefinition();
5019 if (TagDecl *TD = dyn_cast<TagDecl>(D))
5020 return TD->getDefinition();
5021 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
5022 return ID->getDefinition();
5023 if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
5024 return PD->getDefinition();
5025 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
5026 return getDefinitionToImport(TD->getTemplatedDecl());
5030 void Sema::diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl,
5031 MissingImportKind MIK, bool Recover) {
5032 // Suggest importing a module providing the definition of this entity, if
5034 NamedDecl *Def = getDefinitionToImport(Decl);
5038 Module *Owner = getOwningModule(Decl);
5039 assert(Owner && "definition of hidden declaration is not in a module");
5041 llvm::SmallVector<Module*, 8> OwningModules;
5042 OwningModules.push_back(Owner);
5043 auto Merged = Context.getModulesWithMergedDefinition(Decl);
5044 OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end());
5046 diagnoseMissingImport(Loc, Decl, Decl->getLocation(), OwningModules, MIK,
5050 /// \brief Get a "quoted.h" or <angled.h> include path to use in a diagnostic
5051 /// suggesting the addition of a #include of the specified file.
5052 static std::string getIncludeStringForHeader(Preprocessor &PP,
5053 const FileEntry *E) {
5056 PP.getHeaderSearchInfo().suggestPathToFileForDiagnostics(E, &IsSystem);
5057 return (IsSystem ? '<' : '"') + Path + (IsSystem ? '>' : '"');
5060 void Sema::diagnoseMissingImport(SourceLocation UseLoc, NamedDecl *Decl,
5061 SourceLocation DeclLoc,
5062 ArrayRef<Module *> Modules,
5063 MissingImportKind MIK, bool Recover) {
5064 assert(!Modules.empty());
5066 // Weed out duplicates from module list.
5067 llvm::SmallVector<Module*, 8> UniqueModules;
5068 llvm::SmallDenseSet<Module*, 8> UniqueModuleSet;
5069 for (auto *M : Modules)
5070 if (UniqueModuleSet.insert(M).second)
5071 UniqueModules.push_back(M);
5072 Modules = UniqueModules;
5074 if (Modules.size() > 1) {
5075 std::string ModuleList;
5077 for (Module *M : Modules) {
5078 ModuleList += "\n ";
5079 if (++N == 5 && N != Modules.size()) {
5080 ModuleList += "[...]";
5083 ModuleList += M->getFullModuleName();
5086 Diag(UseLoc, diag::err_module_unimported_use_multiple)
5087 << (int)MIK << Decl << ModuleList;
5088 } else if (const FileEntry *E = PP.getModuleHeaderToIncludeForDiagnostics(
5089 UseLoc, Modules[0], DeclLoc)) {
5090 // The right way to make the declaration visible is to include a header;
5091 // suggest doing so.
5093 // FIXME: Find a smart place to suggest inserting a #include, and add
5094 // a FixItHint there.
5095 Diag(UseLoc, diag::err_module_unimported_use_header)
5096 << (int)MIK << Decl << Modules[0]->getFullModuleName()
5097 << getIncludeStringForHeader(PP, E);
5099 // FIXME: Add a FixItHint that imports the corresponding module.
5100 Diag(UseLoc, diag::err_module_unimported_use)
5101 << (int)MIK << Decl << Modules[0]->getFullModuleName();
5106 case MissingImportKind::Declaration:
5107 DiagID = diag::note_previous_declaration;
5109 case MissingImportKind::Definition:
5110 DiagID = diag::note_previous_definition;
5112 case MissingImportKind::DefaultArgument:
5113 DiagID = diag::note_default_argument_declared_here;
5115 case MissingImportKind::ExplicitSpecialization:
5116 DiagID = diag::note_explicit_specialization_declared_here;
5118 case MissingImportKind::PartialSpecialization:
5119 DiagID = diag::note_partial_specialization_declared_here;
5122 Diag(DeclLoc, DiagID);
5124 // Try to recover by implicitly importing this module.
5126 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5129 /// \brief Diagnose a successfully-corrected typo. Separated from the correction
5130 /// itself to allow external validation of the result, etc.
5132 /// \param Correction The result of performing typo correction.
5133 /// \param TypoDiag The diagnostic to produce. This will have the corrected
5134 /// string added to it (and usually also a fixit).
5135 /// \param PrevNote A note to use when indicating the location of the entity to
5136 /// which we are correcting. Will have the correction string added to it.
5137 /// \param ErrorRecovery If \c true (the default), the caller is going to
5138 /// recover from the typo as if the corrected string had been typed.
5139 /// In this case, \c PDiag must be an error, and we will attach a fixit
5141 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5142 const PartialDiagnostic &TypoDiag,
5143 const PartialDiagnostic &PrevNote,
5144 bool ErrorRecovery) {
5145 std::string CorrectedStr = Correction.getAsString(getLangOpts());
5146 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
5147 FixItHint FixTypo = FixItHint::CreateReplacement(
5148 Correction.getCorrectionRange(), CorrectedStr);
5150 // Maybe we're just missing a module import.
5151 if (Correction.requiresImport()) {
5152 NamedDecl *Decl = Correction.getFoundDecl();
5153 assert(Decl && "import required but no declaration to import");
5155 diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl,
5156 MissingImportKind::Declaration, ErrorRecovery);
5160 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
5161 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
5163 NamedDecl *ChosenDecl =
5164 Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
5165 if (PrevNote.getDiagID() && ChosenDecl)
5166 Diag(ChosenDecl->getLocation(), PrevNote)
5167 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
5169 // Add any extra diagnostics.
5170 for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
5171 Diag(Correction.getCorrectionRange().getBegin(), PD);
5174 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
5175 TypoDiagnosticGenerator TDG,
5176 TypoRecoveryCallback TRC) {
5177 assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer");
5178 auto TE = new (Context) TypoExpr(Context.DependentTy);
5179 auto &State = DelayedTypos[TE];
5180 State.Consumer = std::move(TCC);
5181 State.DiagHandler = std::move(TDG);
5182 State.RecoveryHandler = std::move(TRC);
5186 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const {
5187 auto Entry = DelayedTypos.find(TE);
5188 assert(Entry != DelayedTypos.end() &&
5189 "Failed to get the state for a TypoExpr!");
5190 return Entry->second;
5193 void Sema::clearDelayedTypo(TypoExpr *TE) {
5194 DelayedTypos.erase(TE);
5197 void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) {
5198 DeclarationNameInfo Name(II, IILoc);
5199 LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration);
5200 R.suppressDiagnostics();
5201 R.setHideTags(false);