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));
189 void done() { llvm::sort(list, UnqualUsingEntry::Comparator()); }
191 typedef ListTy::const_iterator const_iterator;
193 const_iterator begin() const { return list.begin(); }
194 const_iterator end() const { return list.end(); }
196 llvm::iterator_range<const_iterator>
197 getNamespacesFor(DeclContext *DC) const {
198 return llvm::make_range(std::equal_range(begin(), end(),
199 DC->getPrimaryContext(),
200 UnqualUsingEntry::Comparator()));
203 } // end anonymous namespace
205 // Retrieve the set of identifier namespaces that correspond to a
206 // specific kind of name lookup.
207 static inline unsigned getIDNS(Sema::LookupNameKind NameKind,
209 bool Redeclaration) {
212 case Sema::LookupObjCImplicitSelfParam:
213 case Sema::LookupOrdinaryName:
214 case Sema::LookupRedeclarationWithLinkage:
215 case Sema::LookupLocalFriendName:
216 IDNS = Decl::IDNS_Ordinary;
218 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace;
220 IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend;
223 IDNS |= Decl::IDNS_LocalExtern;
226 case Sema::LookupOperatorName:
227 // Operator lookup is its own crazy thing; it is not the same
228 // as (e.g.) looking up an operator name for redeclaration.
229 assert(!Redeclaration && "cannot do redeclaration operator lookup");
230 IDNS = Decl::IDNS_NonMemberOperator;
233 case Sema::LookupTagName:
235 IDNS = Decl::IDNS_Type;
237 // When looking for a redeclaration of a tag name, we add:
238 // 1) TagFriend to find undeclared friend decls
239 // 2) Namespace because they can't "overload" with tag decls.
240 // 3) Tag because it includes class templates, which can't
241 // "overload" with tag decls.
243 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace;
245 IDNS = Decl::IDNS_Tag;
249 case Sema::LookupLabel:
250 IDNS = Decl::IDNS_Label;
253 case Sema::LookupMemberName:
254 IDNS = Decl::IDNS_Member;
256 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary;
259 case Sema::LookupNestedNameSpecifierName:
260 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace;
263 case Sema::LookupNamespaceName:
264 IDNS = Decl::IDNS_Namespace;
267 case Sema::LookupUsingDeclName:
268 assert(Redeclaration && "should only be used for redecl lookup");
269 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member |
270 Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend |
271 Decl::IDNS_LocalExtern;
274 case Sema::LookupObjCProtocolName:
275 IDNS = Decl::IDNS_ObjCProtocol;
278 case Sema::LookupOMPReductionName:
279 IDNS = Decl::IDNS_OMPReduction;
282 case Sema::LookupAnyName:
283 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member
284 | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol
291 void LookupResult::configure() {
292 IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus,
293 isForRedeclaration());
295 // If we're looking for one of the allocation or deallocation
296 // operators, make sure that the implicitly-declared new and delete
297 // operators can be found.
298 switch (NameInfo.getName().getCXXOverloadedOperator()) {
302 case OO_Array_Delete:
303 getSema().DeclareGlobalNewDelete();
310 // Compiler builtins are always visible, regardless of where they end
311 // up being declared.
312 if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) {
313 if (unsigned BuiltinID = Id->getBuiltinID()) {
314 if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
320 bool LookupResult::sanity() const {
321 // This function is never called by NDEBUG builds.
322 assert(ResultKind != NotFound || Decls.size() == 0);
323 assert(ResultKind != Found || Decls.size() == 1);
324 assert(ResultKind != FoundOverloaded || Decls.size() > 1 ||
325 (Decls.size() == 1 &&
326 isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl())));
327 assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved());
328 assert(ResultKind != Ambiguous || Decls.size() > 1 ||
329 (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects ||
330 Ambiguity == AmbiguousBaseSubobjectTypes)));
331 assert((Paths != nullptr) == (ResultKind == Ambiguous &&
332 (Ambiguity == AmbiguousBaseSubobjectTypes ||
333 Ambiguity == AmbiguousBaseSubobjects)));
337 // Necessary because CXXBasePaths is not complete in Sema.h
338 void LookupResult::deletePaths(CXXBasePaths *Paths) {
342 /// Get a representative context for a declaration such that two declarations
343 /// will have the same context if they were found within the same scope.
344 static DeclContext *getContextForScopeMatching(Decl *D) {
345 // For function-local declarations, use that function as the context. This
346 // doesn't account for scopes within the function; the caller must deal with
348 DeclContext *DC = D->getLexicalDeclContext();
349 if (DC->isFunctionOrMethod())
352 // Otherwise, look at the semantic context of the declaration. The
353 // declaration must have been found there.
354 return D->getDeclContext()->getRedeclContext();
357 /// Determine whether \p D is a better lookup result than \p Existing,
358 /// given that they declare the same entity.
359 static bool isPreferredLookupResult(Sema &S, Sema::LookupNameKind Kind,
360 NamedDecl *D, NamedDecl *Existing) {
361 // When looking up redeclarations of a using declaration, prefer a using
362 // shadow declaration over any other declaration of the same entity.
363 if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(D) &&
364 !isa<UsingShadowDecl>(Existing))
367 auto *DUnderlying = D->getUnderlyingDecl();
368 auto *EUnderlying = Existing->getUnderlyingDecl();
370 // If they have different underlying declarations, prefer a typedef over the
371 // original type (this happens when two type declarations denote the same
372 // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef
373 // might carry additional semantic information, such as an alignment override.
374 // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag
375 // declaration over a typedef.
376 if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) {
377 assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying));
378 bool HaveTag = isa<TagDecl>(EUnderlying);
379 bool WantTag = Kind == Sema::LookupTagName;
380 return HaveTag != WantTag;
383 // Pick the function with more default arguments.
384 // FIXME: In the presence of ambiguous default arguments, we should keep both,
385 // so we can diagnose the ambiguity if the default argument is needed.
386 // See C++ [over.match.best]p3.
387 if (auto *DFD = dyn_cast<FunctionDecl>(DUnderlying)) {
388 auto *EFD = cast<FunctionDecl>(EUnderlying);
389 unsigned DMin = DFD->getMinRequiredArguments();
390 unsigned EMin = EFD->getMinRequiredArguments();
391 // If D has more default arguments, it is preferred.
394 // FIXME: When we track visibility for default function arguments, check
395 // that we pick the declaration with more visible default arguments.
398 // Pick the template with more default template arguments.
399 if (auto *DTD = dyn_cast<TemplateDecl>(DUnderlying)) {
400 auto *ETD = cast<TemplateDecl>(EUnderlying);
401 unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments();
402 unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments();
403 // If D has more default arguments, it is preferred. Note that default
404 // arguments (and their visibility) is monotonically increasing across the
405 // redeclaration chain, so this is a quick proxy for "is more recent".
408 // If D has more *visible* default arguments, it is preferred. Note, an
409 // earlier default argument being visible does not imply that a later
410 // default argument is visible, so we can't just check the first one.
411 for (unsigned I = DMin, N = DTD->getTemplateParameters()->size();
413 if (!S.hasVisibleDefaultArgument(
414 ETD->getTemplateParameters()->getParam(I)) &&
415 S.hasVisibleDefaultArgument(
416 DTD->getTemplateParameters()->getParam(I)))
421 // VarDecl can have incomplete array types, prefer the one with more complete
423 if (VarDecl *DVD = dyn_cast<VarDecl>(DUnderlying)) {
424 VarDecl *EVD = cast<VarDecl>(EUnderlying);
425 if (EVD->getType()->isIncompleteType() &&
426 !DVD->getType()->isIncompleteType()) {
427 // Prefer the decl with a more complete type if visible.
428 return S.isVisible(DVD);
430 return false; // Avoid picking up a newer decl, just because it was newer.
433 // For most kinds of declaration, it doesn't really matter which one we pick.
434 if (!isa<FunctionDecl>(DUnderlying) && !isa<VarDecl>(DUnderlying)) {
435 // If the existing declaration is hidden, prefer the new one. Otherwise,
436 // keep what we've got.
437 return !S.isVisible(Existing);
440 // Pick the newer declaration; it might have a more precise type.
441 for (Decl *Prev = DUnderlying->getPreviousDecl(); Prev;
442 Prev = Prev->getPreviousDecl())
443 if (Prev == EUnderlying)
448 /// Determine whether \p D can hide a tag declaration.
449 static bool canHideTag(NamedDecl *D) {
450 // C++ [basic.scope.declarative]p4:
451 // Given a set of declarations in a single declarative region [...]
452 // exactly one declaration shall declare a class name or enumeration name
453 // that is not a typedef name and the other declarations shall all refer to
454 // the same variable, non-static data member, or enumerator, or all refer
455 // to functions and function templates; in this case the class name or
456 // enumeration name is hidden.
457 // C++ [basic.scope.hiding]p2:
458 // A class name or enumeration name can be hidden by the name of a
459 // variable, data member, function, or enumerator declared in the same
461 // An UnresolvedUsingValueDecl always instantiates to one of these.
462 D = D->getUnderlyingDecl();
463 return isa<VarDecl>(D) || isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D) ||
464 isa<FunctionTemplateDecl>(D) || isa<FieldDecl>(D) ||
465 isa<UnresolvedUsingValueDecl>(D);
468 /// Resolves the result kind of this lookup.
469 void LookupResult::resolveKind() {
470 unsigned N = Decls.size();
472 // Fast case: no possible ambiguity.
474 assert(ResultKind == NotFound ||
475 ResultKind == NotFoundInCurrentInstantiation);
479 // If there's a single decl, we need to examine it to decide what
480 // kind of lookup this is.
482 NamedDecl *D = (*Decls.begin())->getUnderlyingDecl();
483 if (isa<FunctionTemplateDecl>(D))
484 ResultKind = FoundOverloaded;
485 else if (isa<UnresolvedUsingValueDecl>(D))
486 ResultKind = FoundUnresolvedValue;
490 // Don't do any extra resolution if we've already resolved as ambiguous.
491 if (ResultKind == Ambiguous) return;
493 llvm::SmallDenseMap<NamedDecl*, unsigned, 16> Unique;
494 llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes;
496 bool Ambiguous = false;
497 bool HasTag = false, HasFunction = false;
498 bool HasFunctionTemplate = false, HasUnresolved = false;
499 NamedDecl *HasNonFunction = nullptr;
501 llvm::SmallVector<NamedDecl*, 4> EquivalentNonFunctions;
503 unsigned UniqueTagIndex = 0;
507 NamedDecl *D = Decls[I]->getUnderlyingDecl();
508 D = cast<NamedDecl>(D->getCanonicalDecl());
510 // Ignore an invalid declaration unless it's the only one left.
511 if (D->isInvalidDecl() && !(I == 0 && N == 1)) {
512 Decls[I] = Decls[--N];
516 llvm::Optional<unsigned> ExistingI;
518 // Redeclarations of types via typedef can occur both within a scope
519 // and, through using declarations and directives, across scopes. There is
520 // no ambiguity if they all refer to the same type, so unique based on the
522 if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) {
523 QualType T = getSema().Context.getTypeDeclType(TD);
524 auto UniqueResult = UniqueTypes.insert(
525 std::make_pair(getSema().Context.getCanonicalType(T), I));
526 if (!UniqueResult.second) {
527 // The type is not unique.
528 ExistingI = UniqueResult.first->second;
532 // For non-type declarations, check for a prior lookup result naming this
533 // canonical declaration.
535 auto UniqueResult = Unique.insert(std::make_pair(D, I));
536 if (!UniqueResult.second) {
537 // We've seen this entity before.
538 ExistingI = UniqueResult.first->second;
543 // This is not a unique lookup result. Pick one of the results and
544 // discard the other.
545 if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I],
547 Decls[*ExistingI] = Decls[I];
548 Decls[I] = Decls[--N];
552 // Otherwise, do some decl type analysis and then continue.
554 if (isa<UnresolvedUsingValueDecl>(D)) {
555 HasUnresolved = true;
556 } else if (isa<TagDecl>(D)) {
561 } else if (isa<FunctionTemplateDecl>(D)) {
563 HasFunctionTemplate = true;
564 } else if (isa<FunctionDecl>(D)) {
567 if (HasNonFunction) {
568 // If we're about to create an ambiguity between two declarations that
569 // are equivalent, but one is an internal linkage declaration from one
570 // module and the other is an internal linkage declaration from another
571 // module, just skip it.
572 if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction,
574 EquivalentNonFunctions.push_back(D);
575 Decls[I] = Decls[--N];
586 // C++ [basic.scope.hiding]p2:
587 // A class name or enumeration name can be hidden by the name of
588 // an object, function, or enumerator declared in the same
589 // scope. If a class or enumeration name and an object, function,
590 // or enumerator are declared in the same scope (in any order)
591 // with the same name, the class or enumeration name is hidden
592 // wherever the object, function, or enumerator name is visible.
593 // But it's still an error if there are distinct tag types found,
594 // even if they're not visible. (ref?)
595 if (N > 1 && HideTags && HasTag && !Ambiguous &&
596 (HasFunction || HasNonFunction || HasUnresolved)) {
597 NamedDecl *OtherDecl = Decls[UniqueTagIndex ? 0 : N - 1];
598 if (isa<TagDecl>(Decls[UniqueTagIndex]->getUnderlyingDecl()) &&
599 getContextForScopeMatching(Decls[UniqueTagIndex])->Equals(
600 getContextForScopeMatching(OtherDecl)) &&
601 canHideTag(OtherDecl))
602 Decls[UniqueTagIndex] = Decls[--N];
607 // FIXME: This diagnostic should really be delayed until we're done with
608 // the lookup result, in case the ambiguity is resolved by the caller.
609 if (!EquivalentNonFunctions.empty() && !Ambiguous)
610 getSema().diagnoseEquivalentInternalLinkageDeclarations(
611 getNameLoc(), HasNonFunction, EquivalentNonFunctions);
615 if (HasNonFunction && (HasFunction || HasUnresolved))
619 setAmbiguous(LookupResult::AmbiguousReference);
620 else if (HasUnresolved)
621 ResultKind = LookupResult::FoundUnresolvedValue;
622 else if (N > 1 || HasFunctionTemplate)
623 ResultKind = LookupResult::FoundOverloaded;
625 ResultKind = LookupResult::Found;
628 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
629 CXXBasePaths::const_paths_iterator I, E;
630 for (I = P.begin(), E = P.end(); I != E; ++I)
631 for (DeclContext::lookup_iterator DI = I->Decls.begin(),
632 DE = I->Decls.end(); DI != DE; ++DI)
636 void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) {
637 Paths = new CXXBasePaths;
639 addDeclsFromBasePaths(*Paths);
641 setAmbiguous(AmbiguousBaseSubobjects);
644 void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) {
645 Paths = new CXXBasePaths;
647 addDeclsFromBasePaths(*Paths);
649 setAmbiguous(AmbiguousBaseSubobjectTypes);
652 void LookupResult::print(raw_ostream &Out) {
653 Out << Decls.size() << " result(s)";
654 if (isAmbiguous()) Out << ", ambiguous";
655 if (Paths) Out << ", base paths present";
657 for (iterator I = begin(), E = end(); I != E; ++I) {
663 LLVM_DUMP_METHOD void LookupResult::dump() {
664 llvm::errs() << "lookup results for " << getLookupName().getAsString()
666 for (NamedDecl *D : *this)
670 /// Lookup a builtin function, when name lookup would otherwise
672 static bool LookupBuiltin(Sema &S, LookupResult &R) {
673 Sema::LookupNameKind NameKind = R.getLookupKind();
675 // If we didn't find a use of this identifier, and if the identifier
676 // corresponds to a compiler builtin, create the decl object for the builtin
677 // now, injecting it into translation unit scope, and return it.
678 if (NameKind == Sema::LookupOrdinaryName ||
679 NameKind == Sema::LookupRedeclarationWithLinkage) {
680 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo();
682 if (S.getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName) {
683 if (II == S.getASTContext().getMakeIntegerSeqName()) {
684 R.addDecl(S.getASTContext().getMakeIntegerSeqDecl());
686 } else if (II == S.getASTContext().getTypePackElementName()) {
687 R.addDecl(S.getASTContext().getTypePackElementDecl());
692 // If this is a builtin on this (or all) targets, create the decl.
693 if (unsigned BuiltinID = II->getBuiltinID()) {
694 // In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined
695 // library functions like 'malloc'. Instead, we'll just error.
696 if ((S.getLangOpts().CPlusPlus || S.getLangOpts().OpenCL) &&
697 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
700 if (NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II,
701 BuiltinID, S.TUScope,
702 R.isForRedeclaration(),
714 /// Determine whether we can declare a special member function within
715 /// the class at this point.
716 static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) {
717 // We need to have a definition for the class.
718 if (!Class->getDefinition() || Class->isDependentContext())
721 // We can't be in the middle of defining the class.
722 return !Class->isBeingDefined();
725 void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) {
726 if (!CanDeclareSpecialMemberFunction(Class))
729 // If the default constructor has not yet been declared, do so now.
730 if (Class->needsImplicitDefaultConstructor())
731 DeclareImplicitDefaultConstructor(Class);
733 // If the copy constructor has not yet been declared, do so now.
734 if (Class->needsImplicitCopyConstructor())
735 DeclareImplicitCopyConstructor(Class);
737 // If the copy assignment operator has not yet been declared, do so now.
738 if (Class->needsImplicitCopyAssignment())
739 DeclareImplicitCopyAssignment(Class);
741 if (getLangOpts().CPlusPlus11) {
742 // If the move constructor has not yet been declared, do so now.
743 if (Class->needsImplicitMoveConstructor())
744 DeclareImplicitMoveConstructor(Class);
746 // If the move assignment operator has not yet been declared, do so now.
747 if (Class->needsImplicitMoveAssignment())
748 DeclareImplicitMoveAssignment(Class);
751 // If the destructor has not yet been declared, do so now.
752 if (Class->needsImplicitDestructor())
753 DeclareImplicitDestructor(Class);
756 /// Determine whether this is the name of an implicitly-declared
757 /// special member function.
758 static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) {
759 switch (Name.getNameKind()) {
760 case DeclarationName::CXXConstructorName:
761 case DeclarationName::CXXDestructorName:
764 case DeclarationName::CXXOperatorName:
765 return Name.getCXXOverloadedOperator() == OO_Equal;
774 /// If there are any implicit member functions with the given name
775 /// that need to be declared in the given declaration context, do so.
776 static void DeclareImplicitMemberFunctionsWithName(Sema &S,
777 DeclarationName Name,
779 const DeclContext *DC) {
783 switch (Name.getNameKind()) {
784 case DeclarationName::CXXConstructorName:
785 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
786 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
787 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
788 if (Record->needsImplicitDefaultConstructor())
789 S.DeclareImplicitDefaultConstructor(Class);
790 if (Record->needsImplicitCopyConstructor())
791 S.DeclareImplicitCopyConstructor(Class);
792 if (S.getLangOpts().CPlusPlus11 &&
793 Record->needsImplicitMoveConstructor())
794 S.DeclareImplicitMoveConstructor(Class);
798 case DeclarationName::CXXDestructorName:
799 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
800 if (Record->getDefinition() && Record->needsImplicitDestructor() &&
801 CanDeclareSpecialMemberFunction(Record))
802 S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record));
805 case DeclarationName::CXXOperatorName:
806 if (Name.getCXXOverloadedOperator() != OO_Equal)
809 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) {
810 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
811 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
812 if (Record->needsImplicitCopyAssignment())
813 S.DeclareImplicitCopyAssignment(Class);
814 if (S.getLangOpts().CPlusPlus11 &&
815 Record->needsImplicitMoveAssignment())
816 S.DeclareImplicitMoveAssignment(Class);
821 case DeclarationName::CXXDeductionGuideName:
822 S.DeclareImplicitDeductionGuides(Name.getCXXDeductionGuideTemplate(), Loc);
830 // Adds all qualifying matches for a name within a decl context to the
831 // given lookup result. Returns true if any matches were found.
832 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
835 // Lazily declare C++ special member functions.
836 if (S.getLangOpts().CPlusPlus)
837 DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), R.getNameLoc(),
840 // Perform lookup into this declaration context.
841 DeclContext::lookup_result DR = DC->lookup(R.getLookupName());
842 for (NamedDecl *D : DR) {
843 if ((D = R.getAcceptableDecl(D))) {
849 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R))
852 if (R.getLookupName().getNameKind()
853 != DeclarationName::CXXConversionFunctionName ||
854 R.getLookupName().getCXXNameType()->isDependentType() ||
855 !isa<CXXRecordDecl>(DC))
859 // A specialization of a conversion function template is not found by
860 // name lookup. Instead, any conversion function templates visible in the
861 // context of the use are considered. [...]
862 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
863 if (!Record->isCompleteDefinition())
866 // For conversion operators, 'operator auto' should only match
867 // 'operator auto'. Since 'auto' is not a type, it shouldn't be considered
868 // as a candidate for template substitution.
869 auto *ContainedDeducedType =
870 R.getLookupName().getCXXNameType()->getContainedDeducedType();
871 if (R.getLookupName().getNameKind() ==
872 DeclarationName::CXXConversionFunctionName &&
873 ContainedDeducedType && ContainedDeducedType->isUndeducedType())
876 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(),
877 UEnd = Record->conversion_end(); U != UEnd; ++U) {
878 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
882 // When we're performing lookup for the purposes of redeclaration, just
883 // add the conversion function template. When we deduce template
884 // arguments for specializations, we'll end up unifying the return
885 // type of the new declaration with the type of the function template.
886 if (R.isForRedeclaration()) {
887 R.addDecl(ConvTemplate);
893 // [...] For each such operator, if argument deduction succeeds
894 // (14.9.2.3), the resulting specialization is used as if found by
897 // When referencing a conversion function for any purpose other than
898 // a redeclaration (such that we'll be building an expression with the
899 // result), perform template argument deduction and place the
900 // specialization into the result set. We do this to avoid forcing all
901 // callers to perform special deduction for conversion functions.
902 TemplateDeductionInfo Info(R.getNameLoc());
903 FunctionDecl *Specialization = nullptr;
905 const FunctionProtoType *ConvProto
906 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
907 assert(ConvProto && "Nonsensical conversion function template type");
909 // Compute the type of the function that we would expect the conversion
910 // function to have, if it were to match the name given.
911 // FIXME: Calling convention!
912 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo();
913 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C);
914 EPI.ExceptionSpec = EST_None;
915 QualType ExpectedType
916 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(),
919 // Perform template argument deduction against the type that we would
920 // expect the function to have.
921 if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType,
922 Specialization, Info)
923 == Sema::TDK_Success) {
924 R.addDecl(Specialization);
932 // Performs C++ unqualified lookup into the given file context.
934 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context,
935 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
937 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
939 // Perform direct name lookup into the LookupCtx.
940 bool Found = LookupDirect(S, R, NS);
942 // Perform direct name lookup into the namespaces nominated by the
943 // using directives whose common ancestor is this namespace.
944 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS))
945 if (LookupDirect(S, R, UUE.getNominatedNamespace()))
953 static bool isNamespaceOrTranslationUnitScope(Scope *S) {
954 if (DeclContext *Ctx = S->getEntity())
955 return Ctx->isFileContext();
959 // Find the next outer declaration context from this scope. This
960 // routine actually returns the semantic outer context, which may
961 // differ from the lexical context (encoded directly in the Scope
962 // stack) when we are parsing a member of a class template. In this
963 // case, the second element of the pair will be true, to indicate that
964 // name lookup should continue searching in this semantic context when
965 // it leaves the current template parameter scope.
966 static std::pair<DeclContext *, bool> findOuterContext(Scope *S) {
967 DeclContext *DC = S->getEntity();
968 DeclContext *Lexical = nullptr;
969 for (Scope *OuterS = S->getParent(); OuterS;
970 OuterS = OuterS->getParent()) {
971 if (OuterS->getEntity()) {
972 Lexical = OuterS->getEntity();
977 // C++ [temp.local]p8:
978 // In the definition of a member of a class template that appears
979 // outside of the namespace containing the class template
980 // definition, the name of a template-parameter hides the name of
981 // a member of this namespace.
988 // template<class T> class B {
993 // template<class C> void N::B<C>::f(C) {
994 // C b; // C is the template parameter, not N::C
997 // In this example, the lexical context we return is the
998 // TranslationUnit, while the semantic context is the namespace N.
999 if (!Lexical || !DC || !S->getParent() ||
1000 !S->getParent()->isTemplateParamScope())
1001 return std::make_pair(Lexical, false);
1003 // Find the outermost template parameter scope.
1004 // For the example, this is the scope for the template parameters of
1005 // template<class C>.
1006 Scope *OutermostTemplateScope = S->getParent();
1007 while (OutermostTemplateScope->getParent() &&
1008 OutermostTemplateScope->getParent()->isTemplateParamScope())
1009 OutermostTemplateScope = OutermostTemplateScope->getParent();
1011 // Find the namespace context in which the original scope occurs. In
1012 // the example, this is namespace N.
1013 DeclContext *Semantic = DC;
1014 while (!Semantic->isFileContext())
1015 Semantic = Semantic->getParent();
1017 // Find the declaration context just outside of the template
1018 // parameter scope. This is the context in which the template is
1019 // being lexically declaration (a namespace context). In the
1020 // example, this is the global scope.
1021 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) &&
1022 Lexical->Encloses(Semantic))
1023 return std::make_pair(Semantic, true);
1025 return std::make_pair(Lexical, false);
1029 /// An RAII object to specify that we want to find block scope extern
1031 struct FindLocalExternScope {
1032 FindLocalExternScope(LookupResult &R)
1033 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
1034 Decl::IDNS_LocalExtern) {
1035 R.setFindLocalExtern(R.getIdentifierNamespace() &
1036 (Decl::IDNS_Ordinary | Decl::IDNS_NonMemberOperator));
1039 R.setFindLocalExtern(OldFindLocalExtern);
1041 ~FindLocalExternScope() {
1045 bool OldFindLocalExtern;
1047 } // end anonymous namespace
1049 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
1050 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
1052 DeclarationName Name = R.getLookupName();
1053 Sema::LookupNameKind NameKind = R.getLookupKind();
1055 // If this is the name of an implicitly-declared special member function,
1056 // go through the scope stack to implicitly declare
1057 if (isImplicitlyDeclaredMemberFunctionName(Name)) {
1058 for (Scope *PreS = S; PreS; PreS = PreS->getParent())
1059 if (DeclContext *DC = PreS->getEntity())
1060 DeclareImplicitMemberFunctionsWithName(*this, Name, R.getNameLoc(), DC);
1063 // Implicitly declare member functions with the name we're looking for, if in
1064 // fact we are in a scope where it matters.
1067 IdentifierResolver::iterator
1068 I = IdResolver.begin(Name),
1069 IEnd = IdResolver.end();
1071 // First we lookup local scope.
1072 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
1073 // ...During unqualified name lookup (3.4.1), the names appear as if
1074 // they were declared in the nearest enclosing namespace which contains
1075 // both the using-directive and the nominated namespace.
1076 // [Note: in this context, "contains" means "contains directly or
1080 // namespace A { int i; }
1084 // using namespace A;
1085 // ++i; // finds local 'i', A::i appears at global scope
1089 UnqualUsingDirectiveSet UDirs(*this);
1090 bool VisitedUsingDirectives = false;
1091 bool LeftStartingScope = false;
1092 DeclContext *OutsideOfTemplateParamDC = nullptr;
1094 // When performing a scope lookup, we want to find local extern decls.
1095 FindLocalExternScope FindLocals(R);
1097 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
1098 DeclContext *Ctx = S->getEntity();
1099 bool SearchNamespaceScope = true;
1100 // Check whether the IdResolver has anything in this scope.
1101 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1102 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1103 if (NameKind == LookupRedeclarationWithLinkage &&
1104 !(*I)->isTemplateParameter()) {
1105 // If it's a template parameter, we still find it, so we can diagnose
1106 // the invalid redeclaration.
1108 // Determine whether this (or a previous) declaration is
1110 if (!LeftStartingScope && !Initial->isDeclScope(*I))
1111 LeftStartingScope = true;
1113 // If we found something outside of our starting scope that
1114 // does not have linkage, skip it.
1115 if (LeftStartingScope && !((*I)->hasLinkage())) {
1120 // We found something in this scope, we should not look at the
1122 SearchNamespaceScope = false;
1127 if (!SearchNamespaceScope) {
1129 if (S->isClassScope())
1130 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx))
1131 R.setNamingClass(Record);
1135 if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
1136 // C++11 [class.friend]p11:
1137 // If a friend declaration appears in a local class and the name
1138 // specified is an unqualified name, a prior declaration is
1139 // looked up without considering scopes that are outside the
1140 // innermost enclosing non-class scope.
1144 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1145 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1146 // We've just searched the last template parameter scope and
1147 // found nothing, so look into the contexts between the
1148 // lexical and semantic declaration contexts returned by
1149 // findOuterContext(). This implements the name lookup behavior
1150 // of C++ [temp.local]p8.
1151 Ctx = OutsideOfTemplateParamDC;
1152 OutsideOfTemplateParamDC = nullptr;
1156 DeclContext *OuterCtx;
1157 bool SearchAfterTemplateScope;
1158 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1159 if (SearchAfterTemplateScope)
1160 OutsideOfTemplateParamDC = OuterCtx;
1162 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1163 // We do not directly look into transparent contexts, since
1164 // those entities will be found in the nearest enclosing
1165 // non-transparent context.
1166 if (Ctx->isTransparentContext())
1169 // We do not look directly into function or method contexts,
1170 // since all of the local variables and parameters of the
1171 // function/method are present within the Scope.
1172 if (Ctx->isFunctionOrMethod()) {
1173 // If we have an Objective-C instance method, look for ivars
1174 // in the corresponding interface.
1175 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
1176 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
1177 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
1178 ObjCInterfaceDecl *ClassDeclared;
1179 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
1180 Name.getAsIdentifierInfo(),
1182 if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
1194 // If this is a file context, we need to perform unqualified name
1195 // lookup considering using directives.
1196 if (Ctx->isFileContext()) {
1197 // If we haven't handled using directives yet, do so now.
1198 if (!VisitedUsingDirectives) {
1199 // Add using directives from this context up to the top level.
1200 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
1201 if (UCtx->isTransparentContext())
1204 UDirs.visit(UCtx, UCtx);
1207 // Find the innermost file scope, so we can add using directives
1208 // from local scopes.
1209 Scope *InnermostFileScope = S;
1210 while (InnermostFileScope &&
1211 !isNamespaceOrTranslationUnitScope(InnermostFileScope))
1212 InnermostFileScope = InnermostFileScope->getParent();
1213 UDirs.visitScopeChain(Initial, InnermostFileScope);
1217 VisitedUsingDirectives = true;
1220 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
1228 // Perform qualified name lookup into this context.
1229 // FIXME: In some cases, we know that every name that could be found by
1230 // this qualified name lookup will also be on the identifier chain. For
1231 // example, inside a class without any base classes, we never need to
1232 // perform qualified lookup because all of the members are on top of the
1233 // identifier chain.
1234 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
1240 // Stop if we ran out of scopes.
1241 // FIXME: This really, really shouldn't be happening.
1242 if (!S) return false;
1244 // If we are looking for members, no need to look into global/namespace scope.
1245 if (NameKind == LookupMemberName)
1248 // Collect UsingDirectiveDecls in all scopes, and recursively all
1249 // nominated namespaces by those using-directives.
1251 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
1252 // don't build it for each lookup!
1253 if (!VisitedUsingDirectives) {
1254 UDirs.visitScopeChain(Initial, S);
1258 // If we're not performing redeclaration lookup, do not look for local
1259 // extern declarations outside of a function scope.
1260 if (!R.isForRedeclaration())
1261 FindLocals.restore();
1263 // Lookup namespace scope, and global scope.
1264 // Unqualified name lookup in C++ requires looking into scopes
1265 // that aren't strictly lexical, and therefore we walk through the
1266 // context as well as walking through the scopes.
1267 for (; S; S = S->getParent()) {
1268 // Check whether the IdResolver has anything in this scope.
1270 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1271 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1272 // We found something. Look for anything else in our scope
1273 // with this same name and in an acceptable identifier
1274 // namespace, so that we can construct an overload set if we
1281 if (Found && S->isTemplateParamScope()) {
1286 DeclContext *Ctx = S->getEntity();
1287 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1288 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1289 // We've just searched the last template parameter scope and
1290 // found nothing, so look into the contexts between the
1291 // lexical and semantic declaration contexts returned by
1292 // findOuterContext(). This implements the name lookup behavior
1293 // of C++ [temp.local]p8.
1294 Ctx = OutsideOfTemplateParamDC;
1295 OutsideOfTemplateParamDC = nullptr;
1299 DeclContext *OuterCtx;
1300 bool SearchAfterTemplateScope;
1301 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1302 if (SearchAfterTemplateScope)
1303 OutsideOfTemplateParamDC = OuterCtx;
1305 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1306 // We do not directly look into transparent contexts, since
1307 // those entities will be found in the nearest enclosing
1308 // non-transparent context.
1309 if (Ctx->isTransparentContext())
1312 // If we have a context, and it's not a context stashed in the
1313 // template parameter scope for an out-of-line definition, also
1314 // look into that context.
1315 if (!(Found && S->isTemplateParamScope())) {
1316 assert(Ctx->isFileContext() &&
1317 "We should have been looking only at file context here already.");
1319 // Look into context considering using-directives.
1320 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
1329 if (R.isForRedeclaration() && !Ctx->isTransparentContext())
1334 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
1341 void Sema::makeMergedDefinitionVisible(NamedDecl *ND) {
1342 if (auto *M = getCurrentModule())
1343 Context.mergeDefinitionIntoModule(ND, M);
1345 // We're not building a module; just make the definition visible.
1346 ND->setVisibleDespiteOwningModule();
1348 // If ND is a template declaration, make the template parameters
1349 // visible too. They're not (necessarily) within a mergeable DeclContext.
1350 if (auto *TD = dyn_cast<TemplateDecl>(ND))
1351 for (auto *Param : *TD->getTemplateParameters())
1352 makeMergedDefinitionVisible(Param);
1355 /// Find the module in which the given declaration was defined.
1356 static Module *getDefiningModule(Sema &S, Decl *Entity) {
1357 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
1358 // If this function was instantiated from a template, the defining module is
1359 // the module containing the pattern.
1360 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1362 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
1363 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1365 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
1366 if (auto *Pattern = ED->getTemplateInstantiationPattern())
1368 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
1369 if (VarDecl *Pattern = VD->getTemplateInstantiationPattern())
1373 // Walk up to the containing context. That might also have been instantiated
1375 DeclContext *Context = Entity->getLexicalDeclContext();
1376 if (Context->isFileContext())
1377 return S.getOwningModule(Entity);
1378 return getDefiningModule(S, cast<Decl>(Context));
1381 llvm::DenseSet<Module*> &Sema::getLookupModules() {
1382 unsigned N = CodeSynthesisContexts.size();
1383 for (unsigned I = CodeSynthesisContextLookupModules.size();
1385 Module *M = getDefiningModule(*this, CodeSynthesisContexts[I].Entity);
1386 if (M && !LookupModulesCache.insert(M).second)
1388 CodeSynthesisContextLookupModules.push_back(M);
1390 return LookupModulesCache;
1393 /// Determine whether the module M is part of the current module from the
1394 /// perspective of a module-private visibility check.
1395 static bool isInCurrentModule(const Module *M, const LangOptions &LangOpts) {
1396 // If M is the global module fragment of a module that we've not yet finished
1397 // parsing, then it must be part of the current module.
1398 return M->getTopLevelModuleName() == LangOpts.CurrentModule ||
1399 (M->Kind == Module::GlobalModuleFragment && !M->Parent);
1402 bool Sema::hasVisibleMergedDefinition(NamedDecl *Def) {
1403 for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1404 if (isModuleVisible(Merged))
1409 bool Sema::hasMergedDefinitionInCurrentModule(NamedDecl *Def) {
1410 for (const Module *Merged : Context.getModulesWithMergedDefinition(Def))
1411 if (isInCurrentModule(Merged, getLangOpts()))
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));
1433 // If there was a previous default argument, maybe its parameter is visible.
1434 D = DefaultArg.getInheritedFrom();
1439 bool Sema::hasVisibleDefaultArgument(const NamedDecl *D,
1440 llvm::SmallVectorImpl<Module *> *Modules) {
1441 if (auto *P = dyn_cast<TemplateTypeParmDecl>(D))
1442 return ::hasVisibleDefaultArgument(*this, P, Modules);
1443 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D))
1444 return ::hasVisibleDefaultArgument(*this, P, Modules);
1445 return ::hasVisibleDefaultArgument(*this, cast<TemplateTemplateParmDecl>(D),
1449 template<typename Filter>
1450 static bool hasVisibleDeclarationImpl(Sema &S, const NamedDecl *D,
1451 llvm::SmallVectorImpl<Module *> *Modules,
1453 bool HasFilteredRedecls = false;
1455 for (auto *Redecl : D->redecls()) {
1456 auto *R = cast<NamedDecl>(Redecl);
1463 HasFilteredRedecls = true;
1466 Modules->push_back(R->getOwningModule());
1469 // Only return false if there is at least one redecl that is not filtered out.
1470 if (HasFilteredRedecls)
1476 bool Sema::hasVisibleExplicitSpecialization(
1477 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1478 return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1479 if (auto *RD = dyn_cast<CXXRecordDecl>(D))
1480 return RD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1481 if (auto *FD = dyn_cast<FunctionDecl>(D))
1482 return FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1483 if (auto *VD = dyn_cast<VarDecl>(D))
1484 return VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1485 llvm_unreachable("unknown explicit specialization kind");
1489 bool Sema::hasVisibleMemberSpecialization(
1490 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1491 assert(isa<CXXRecordDecl>(D->getDeclContext()) &&
1492 "not a member specialization");
1493 return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1494 // If the specialization is declared at namespace scope, then it's a member
1495 // specialization declaration. If it's lexically inside the class
1496 // definition then it was instantiated.
1498 // FIXME: This is a hack. There should be a better way to determine this.
1499 // FIXME: What about MS-style explicit specializations declared within a
1500 // class definition?
1501 return D->getLexicalDeclContext()->isFileContext();
1505 /// Determine whether a declaration is visible to name lookup.
1507 /// This routine determines whether the declaration D is visible in the current
1508 /// lookup context, taking into account the current template instantiation
1509 /// stack. During template instantiation, a declaration is visible if it is
1510 /// visible from a module containing any entity on the template instantiation
1511 /// path (by instantiating a template, you allow it to see the declarations that
1512 /// your module can see, including those later on in your module).
1513 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
1514 assert(D->isHidden() && "should not call this: not in slow case");
1516 Module *DeclModule = SemaRef.getOwningModule(D);
1517 assert(DeclModule && "hidden decl has no owning module");
1519 // If the owning module is visible, the decl is visible.
1520 if (SemaRef.isModuleVisible(DeclModule, D->isModulePrivate()))
1523 // Determine whether a decl context is a file context for the purpose of
1524 // visibility. This looks through some (export and linkage spec) transparent
1525 // contexts, but not others (enums).
1526 auto IsEffectivelyFileContext = [](const DeclContext *DC) {
1527 return DC->isFileContext() || isa<LinkageSpecDecl>(DC) ||
1528 isa<ExportDecl>(DC);
1531 // If this declaration is not at namespace scope
1532 // then it is visible if its lexical parent has a visible definition.
1533 DeclContext *DC = D->getLexicalDeclContext();
1534 if (DC && !IsEffectivelyFileContext(DC)) {
1535 // For a parameter, check whether our current template declaration's
1536 // lexical context is visible, not whether there's some other visible
1537 // definition of it, because parameters aren't "within" the definition.
1539 // In C++ we need to check for a visible definition due to ODR merging,
1540 // and in C we must not because each declaration of a function gets its own
1541 // set of declarations for tags in prototype scope.
1542 bool VisibleWithinParent;
1543 if (D->isTemplateParameter() || isa<ParmVarDecl>(D) ||
1544 (isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus))
1545 VisibleWithinParent = isVisible(SemaRef, cast<NamedDecl>(DC));
1546 else if (D->isModulePrivate()) {
1547 // A module-private declaration is only visible if an enclosing lexical
1548 // parent was merged with another definition in the current module.
1549 VisibleWithinParent = false;
1551 if (SemaRef.hasMergedDefinitionInCurrentModule(cast<NamedDecl>(DC))) {
1552 VisibleWithinParent = true;
1555 DC = DC->getLexicalParent();
1556 } while (!IsEffectivelyFileContext(DC));
1558 VisibleWithinParent = SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC));
1561 if (VisibleWithinParent && SemaRef.CodeSynthesisContexts.empty() &&
1562 // FIXME: Do something better in this case.
1563 !SemaRef.getLangOpts().ModulesLocalVisibility) {
1564 // Cache the fact that this declaration is implicitly visible because
1565 // its parent has a visible definition.
1566 D->setVisibleDespiteOwningModule();
1568 return VisibleWithinParent;
1574 bool Sema::isModuleVisible(const Module *M, bool ModulePrivate) {
1575 // The module might be ordinarily visible. For a module-private query, that
1576 // means it is part of the current module. For any other query, that means it
1577 // is in our visible module set.
1578 if (ModulePrivate) {
1579 if (isInCurrentModule(M, getLangOpts()))
1582 if (VisibleModules.isVisible(M))
1586 // Otherwise, it might be visible by virtue of the query being within a
1587 // template instantiation or similar that is permitted to look inside M.
1589 // Find the extra places where we need to look.
1590 const auto &LookupModules = getLookupModules();
1591 if (LookupModules.empty())
1594 // If our lookup set contains the module, it's visible.
1595 if (LookupModules.count(M))
1598 // For a module-private query, that's everywhere we get to look.
1602 // Check whether M is transitively exported to an import of the lookup set.
1603 return llvm::any_of(LookupModules, [&](const Module *LookupM) {
1604 return LookupM->isModuleVisible(M);
1608 bool Sema::isVisibleSlow(const NamedDecl *D) {
1609 return LookupResult::isVisible(*this, const_cast<NamedDecl*>(D));
1612 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
1613 // FIXME: If there are both visible and hidden declarations, we need to take
1614 // into account whether redeclaration is possible. Example:
1616 // Non-imported module:
1619 // static int f(U); // #2, not a redeclaration of #1
1620 // int f(T); // #3, finds both, should link with #1 if T != U, but
1621 // // with #2 if T == U; neither should be ambiguous.
1625 assert(D->isExternallyDeclarable() &&
1626 "should not have hidden, non-externally-declarable result here");
1629 // This function is called once "New" is essentially complete, but before a
1630 // previous declaration is attached. We can't query the linkage of "New" in
1631 // general, because attaching the previous declaration can change the
1632 // linkage of New to match the previous declaration.
1634 // However, because we've just determined that there is no *visible* prior
1635 // declaration, we can compute the linkage here. There are two possibilities:
1637 // * This is not a redeclaration; it's safe to compute the linkage now.
1639 // * This is a redeclaration of a prior declaration that is externally
1640 // redeclarable. In that case, the linkage of the declaration is not
1641 // changed by attaching the prior declaration, because both are externally
1642 // declarable (and thus ExternalLinkage or VisibleNoLinkage).
1644 // FIXME: This is subtle and fragile.
1645 return New->isExternallyDeclarable();
1648 /// Retrieve the visible declaration corresponding to D, if any.
1650 /// This routine determines whether the declaration D is visible in the current
1651 /// module, with the current imports. If not, it checks whether any
1652 /// redeclaration of D is visible, and if so, returns that declaration.
1654 /// \returns D, or a visible previous declaration of D, whichever is more recent
1655 /// and visible. If no declaration of D is visible, returns null.
1656 static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D,
1658 assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case");
1660 for (auto RD : D->redecls()) {
1661 // Don't bother with extra checks if we already know this one isn't visible.
1665 auto ND = cast<NamedDecl>(RD);
1666 // FIXME: This is wrong in the case where the previous declaration is not
1667 // visible in the same scope as D. This needs to be done much more
1669 if (ND->isInIdentifierNamespace(IDNS) &&
1670 LookupResult::isVisible(SemaRef, ND))
1677 bool Sema::hasVisibleDeclarationSlow(const NamedDecl *D,
1678 llvm::SmallVectorImpl<Module *> *Modules) {
1679 assert(!isVisible(D) && "not in slow case");
1680 return hasVisibleDeclarationImpl(*this, D, Modules,
1681 [](const NamedDecl *) { return true; });
1684 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
1685 if (auto *ND = dyn_cast<NamespaceDecl>(D)) {
1686 // Namespaces are a bit of a special case: we expect there to be a lot of
1687 // redeclarations of some namespaces, all declarations of a namespace are
1688 // essentially interchangeable, all declarations are found by name lookup
1689 // if any is, and namespaces are never looked up during template
1690 // instantiation. So we benefit from caching the check in this case, and
1691 // it is correct to do so.
1692 auto *Key = ND->getCanonicalDecl();
1693 if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key))
1695 auto *Acceptable = isVisible(getSema(), Key)
1697 : findAcceptableDecl(getSema(), Key, IDNS);
1699 getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable));
1703 return findAcceptableDecl(getSema(), D, IDNS);
1706 /// 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 /// 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 /// 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 /// 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 /// 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 /// 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 /// 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 /// 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 /// 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 // 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 // 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 // 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 /// 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 /// 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 /// 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 /// 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 /// 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 /// 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 /// 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 /// 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 /// 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 auto *Underlying = D;
3333 if (auto *USD = dyn_cast<UsingShadowDecl>(D))
3334 Underlying = USD->getTargetDecl();
3336 if (!isa<FunctionDecl>(Underlying) &&
3337 !isa<FunctionTemplateDecl>(Underlying))
3340 // The declaration is visible to argument-dependent lookup if either
3341 // it's ordinarily visible or declared as a friend in an associated
3343 bool Visible = false;
3344 for (D = D->getMostRecentDecl(); D;
3345 D = cast_or_null<NamedDecl>(D->getPreviousDecl())) {
3346 if (D->getIdentifierNamespace() & Decl::IDNS_Ordinary) {
3351 } else if (D->getFriendObjectKind()) {
3352 auto *RD = cast<CXXRecordDecl>(D->getLexicalDeclContext());
3353 if (AssociatedClasses.count(RD) && isVisible(D)) {
3360 // FIXME: Preserve D as the FoundDecl.
3362 Result.insert(Underlying);
3367 //----------------------------------------------------------------------------
3368 // Search for all visible declarations.
3369 //----------------------------------------------------------------------------
3370 VisibleDeclConsumer::~VisibleDeclConsumer() { }
3372 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
3376 class ShadowContextRAII;
3378 class VisibleDeclsRecord {
3380 /// An entry in the shadow map, which is optimized to store a
3381 /// single declaration (the common case) but can also store a list
3382 /// of declarations.
3383 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
3386 /// A mapping from declaration names to the declarations that have
3387 /// this name within a particular scope.
3388 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
3390 /// A list of shadow maps, which is used to model name hiding.
3391 std::list<ShadowMap> ShadowMaps;
3393 /// The declaration contexts we have already visited.
3394 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
3396 friend class ShadowContextRAII;
3399 /// Determine whether we have already visited this context
3400 /// (and, if not, note that we are going to visit that context now).
3401 bool visitedContext(DeclContext *Ctx) {
3402 return !VisitedContexts.insert(Ctx).second;
3405 bool alreadyVisitedContext(DeclContext *Ctx) {
3406 return VisitedContexts.count(Ctx);
3409 /// Determine whether the given declaration is hidden in the
3412 /// \returns the declaration that hides the given declaration, or
3413 /// NULL if no such declaration exists.
3414 NamedDecl *checkHidden(NamedDecl *ND);
3416 /// Add a declaration to the current shadow map.
3417 void add(NamedDecl *ND) {
3418 ShadowMaps.back()[ND->getDeclName()].push_back(ND);
3422 /// RAII object that records when we've entered a shadow context.
3423 class ShadowContextRAII {
3424 VisibleDeclsRecord &Visible;
3426 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
3429 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
3430 Visible.ShadowMaps.emplace_back();
3433 ~ShadowContextRAII() {
3434 Visible.ShadowMaps.pop_back();
3438 } // end anonymous namespace
3440 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
3441 unsigned IDNS = ND->getIdentifierNamespace();
3442 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
3443 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
3444 SM != SMEnd; ++SM) {
3445 ShadowMap::iterator Pos = SM->find(ND->getDeclName());
3446 if (Pos == SM->end())
3449 for (auto *D : Pos->second) {
3450 // A tag declaration does not hide a non-tag declaration.
3451 if (D->hasTagIdentifierNamespace() &&
3452 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
3453 Decl::IDNS_ObjCProtocol)))
3456 // Protocols are in distinct namespaces from everything else.
3457 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
3458 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
3459 D->getIdentifierNamespace() != IDNS)
3462 // Functions and function templates in the same scope overload
3463 // rather than hide. FIXME: Look for hiding based on function
3465 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3466 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3467 SM == ShadowMaps.rbegin())
3470 // A shadow declaration that's created by a resolved using declaration
3471 // is not hidden by the same using declaration.
3472 if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) &&
3473 cast<UsingShadowDecl>(ND)->getUsingDecl() == D)
3476 // We've found a declaration that hides this one.
3484 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
3485 bool QualifiedNameLookup,
3487 VisibleDeclConsumer &Consumer,
3488 VisibleDeclsRecord &Visited,
3489 bool IncludeDependentBases,
3490 bool LoadExternal) {
3494 // Make sure we don't visit the same context twice.
3495 if (Visited.visitedContext(Ctx->getPrimaryContext()))
3498 Consumer.EnteredContext(Ctx);
3500 // Outside C++, lookup results for the TU live on identifiers.
3501 if (isa<TranslationUnitDecl>(Ctx) &&
3502 !Result.getSema().getLangOpts().CPlusPlus) {
3503 auto &S = Result.getSema();
3504 auto &Idents = S.Context.Idents;
3506 // Ensure all external identifiers are in the identifier table.
3508 if (IdentifierInfoLookup *External = Idents.getExternalIdentifierLookup()) {
3509 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
3510 for (StringRef Name = Iter->Next(); !Name.empty(); Name = Iter->Next())
3514 // Walk all lookup results in the TU for each identifier.
3515 for (const auto &Ident : Idents) {
3516 for (auto I = S.IdResolver.begin(Ident.getValue()),
3517 E = S.IdResolver.end();
3519 if (S.IdResolver.isDeclInScope(*I, Ctx)) {
3520 if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
3521 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3531 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
3532 Result.getSema().ForceDeclarationOfImplicitMembers(Class);
3534 // We sometimes skip loading namespace-level results (they tend to be huge).
3535 bool Load = LoadExternal ||
3536 !(isa<TranslationUnitDecl>(Ctx) || isa<NamespaceDecl>(Ctx));
3537 // Enumerate all of the results in this context.
3538 for (DeclContextLookupResult R :
3539 Load ? Ctx->lookups()
3540 : Ctx->noload_lookups(/*PreserveInternalState=*/false)) {
3542 if (auto *ND = Result.getAcceptableDecl(D)) {
3543 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3549 // Traverse using directives for qualified name lookup.
3550 if (QualifiedNameLookup) {
3551 ShadowContextRAII Shadow(Visited);
3552 for (auto I : Ctx->using_directives()) {
3553 if (!Result.getSema().isVisible(I))
3555 LookupVisibleDecls(I->getNominatedNamespace(), Result,
3556 QualifiedNameLookup, InBaseClass, Consumer, Visited,
3557 IncludeDependentBases, LoadExternal);
3561 // Traverse the contexts of inherited C++ classes.
3562 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
3563 if (!Record->hasDefinition())
3566 for (const auto &B : Record->bases()) {
3567 QualType BaseType = B.getType();
3570 if (BaseType->isDependentType()) {
3571 if (!IncludeDependentBases) {
3572 // Don't look into dependent bases, because name lookup can't look
3576 const auto *TST = BaseType->getAs<TemplateSpecializationType>();
3579 TemplateName TN = TST->getTemplateName();
3581 dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl());
3584 RD = TD->getTemplatedDecl();
3586 const auto *Record = BaseType->getAs<RecordType>();
3589 RD = Record->getDecl();
3592 // FIXME: It would be nice to be able to determine whether referencing
3593 // a particular member would be ambiguous. For example, given
3595 // struct A { int member; };
3596 // struct B { int member; };
3597 // struct C : A, B { };
3599 // void f(C *c) { c->### }
3601 // accessing 'member' would result in an ambiguity. However, we
3602 // could be smart enough to qualify the member with the base
3611 // Find results in this base class (and its bases).
3612 ShadowContextRAII Shadow(Visited);
3613 LookupVisibleDecls(RD, Result, QualifiedNameLookup, /*InBaseClass=*/true,
3614 Consumer, Visited, IncludeDependentBases,
3619 // Traverse the contexts of Objective-C classes.
3620 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
3621 // Traverse categories.
3622 for (auto *Cat : IFace->visible_categories()) {
3623 ShadowContextRAII Shadow(Visited);
3624 LookupVisibleDecls(Cat, Result, QualifiedNameLookup, false, Consumer,
3625 Visited, IncludeDependentBases, LoadExternal);
3628 // Traverse protocols.
3629 for (auto *I : IFace->all_referenced_protocols()) {
3630 ShadowContextRAII Shadow(Visited);
3631 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3632 Visited, IncludeDependentBases, LoadExternal);
3635 // Traverse the superclass.
3636 if (IFace->getSuperClass()) {
3637 ShadowContextRAII Shadow(Visited);
3638 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup,
3639 true, Consumer, Visited, IncludeDependentBases,
3643 // If there is an implementation, traverse it. We do this to find
3644 // synthesized ivars.
3645 if (IFace->getImplementation()) {
3646 ShadowContextRAII Shadow(Visited);
3647 LookupVisibleDecls(IFace->getImplementation(), Result,
3648 QualifiedNameLookup, InBaseClass, Consumer, Visited,
3649 IncludeDependentBases, LoadExternal);
3651 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
3652 for (auto *I : Protocol->protocols()) {
3653 ShadowContextRAII Shadow(Visited);
3654 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3655 Visited, IncludeDependentBases, LoadExternal);
3657 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
3658 for (auto *I : Category->protocols()) {
3659 ShadowContextRAII Shadow(Visited);
3660 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3661 Visited, IncludeDependentBases, LoadExternal);
3664 // If there is an implementation, traverse it.
3665 if (Category->getImplementation()) {
3666 ShadowContextRAII Shadow(Visited);
3667 LookupVisibleDecls(Category->getImplementation(), Result,
3668 QualifiedNameLookup, true, Consumer, Visited,
3669 IncludeDependentBases, LoadExternal);
3674 static void LookupVisibleDecls(Scope *S, LookupResult &Result,
3675 UnqualUsingDirectiveSet &UDirs,
3676 VisibleDeclConsumer &Consumer,
3677 VisibleDeclsRecord &Visited,
3678 bool LoadExternal) {
3682 if (!S->getEntity() ||
3684 !Visited.alreadyVisitedContext(S->getEntity())) ||
3685 (S->getEntity())->isFunctionOrMethod()) {
3686 FindLocalExternScope FindLocals(Result);
3687 // Walk through the declarations in this Scope. The consumer might add new
3688 // decls to the scope as part of deserialization, so make a copy first.
3689 SmallVector<Decl *, 8> ScopeDecls(S->decls().begin(), S->decls().end());
3690 for (Decl *D : ScopeDecls) {
3691 if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
3692 if ((ND = Result.getAcceptableDecl(ND))) {
3693 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
3699 // FIXME: C++ [temp.local]p8
3700 DeclContext *Entity = nullptr;
3701 if (S->getEntity()) {
3702 // Look into this scope's declaration context, along with any of its
3703 // parent lookup contexts (e.g., enclosing classes), up to the point
3704 // where we hit the context stored in the next outer scope.
3705 Entity = S->getEntity();
3706 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME
3708 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
3709 Ctx = Ctx->getLookupParent()) {
3710 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
3711 if (Method->isInstanceMethod()) {
3712 // For instance methods, look for ivars in the method's interface.
3713 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
3714 Result.getNameLoc(), Sema::LookupMemberName);
3715 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
3716 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false,
3717 /*InBaseClass=*/false, Consumer, Visited,
3718 /*IncludeDependentBases=*/false, LoadExternal);
3722 // We've already performed all of the name lookup that we need
3723 // to for Objective-C methods; the next context will be the
3728 if (Ctx->isFunctionOrMethod())
3731 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false,
3732 /*InBaseClass=*/false, Consumer, Visited,
3733 /*IncludeDependentBases=*/false, LoadExternal);
3735 } else if (!S->getParent()) {
3736 // Look into the translation unit scope. We walk through the translation
3737 // unit's declaration context, because the Scope itself won't have all of
3738 // the declarations if we loaded a precompiled header.
3739 // FIXME: We would like the translation unit's Scope object to point to the
3740 // translation unit, so we don't need this special "if" branch. However,
3741 // doing so would force the normal C++ name-lookup code to look into the
3742 // translation unit decl when the IdentifierInfo chains would suffice.
3743 // Once we fix that problem (which is part of a more general "don't look
3744 // in DeclContexts unless we have to" optimization), we can eliminate this.
3745 Entity = Result.getSema().Context.getTranslationUnitDecl();
3746 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false,
3747 /*InBaseClass=*/false, Consumer, Visited,
3748 /*IncludeDependentBases=*/false, LoadExternal);
3752 // Lookup visible declarations in any namespaces found by using
3754 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity))
3755 LookupVisibleDecls(const_cast<DeclContext *>(UUE.getNominatedNamespace()),
3756 Result, /*QualifiedNameLookup=*/false,
3757 /*InBaseClass=*/false, Consumer, Visited,
3758 /*IncludeDependentBases=*/false, LoadExternal);
3761 // Lookup names in the parent scope.
3762 ShadowContextRAII Shadow(Visited);
3763 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited,
3767 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
3768 VisibleDeclConsumer &Consumer,
3769 bool IncludeGlobalScope, bool LoadExternal) {
3770 // Determine the set of using directives available during
3771 // unqualified name lookup.
3773 UnqualUsingDirectiveSet UDirs(*this);
3774 if (getLangOpts().CPlusPlus) {
3775 // Find the first namespace or translation-unit scope.
3776 while (S && !isNamespaceOrTranslationUnitScope(S))
3779 UDirs.visitScopeChain(Initial, S);
3783 // Look for visible declarations.
3784 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3785 Result.setAllowHidden(Consumer.includeHiddenDecls());
3786 VisibleDeclsRecord Visited;
3787 if (!IncludeGlobalScope)
3788 Visited.visitedContext(Context.getTranslationUnitDecl());
3789 ShadowContextRAII Shadow(Visited);
3790 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited, LoadExternal);
3793 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
3794 VisibleDeclConsumer &Consumer,
3795 bool IncludeGlobalScope,
3796 bool IncludeDependentBases, bool LoadExternal) {
3797 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3798 Result.setAllowHidden(Consumer.includeHiddenDecls());
3799 VisibleDeclsRecord Visited;
3800 if (!IncludeGlobalScope)
3801 Visited.visitedContext(Context.getTranslationUnitDecl());
3802 ShadowContextRAII Shadow(Visited);
3803 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true,
3804 /*InBaseClass=*/false, Consumer, Visited,
3805 IncludeDependentBases, LoadExternal);
3808 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name.
3809 /// If GnuLabelLoc is a valid source location, then this is a definition
3810 /// of an __label__ label name, otherwise it is a normal label definition
3812 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc,
3813 SourceLocation GnuLabelLoc) {
3814 // Do a lookup to see if we have a label with this name already.
3815 NamedDecl *Res = nullptr;
3817 if (GnuLabelLoc.isValid()) {
3818 // Local label definitions always shadow existing labels.
3819 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
3820 Scope *S = CurScope;
3821 PushOnScopeChains(Res, S, true);
3822 return cast<LabelDecl>(Res);
3825 // Not a GNU local label.
3826 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration);
3827 // If we found a label, check to see if it is in the same context as us.
3828 // When in a Block, we don't want to reuse a label in an enclosing function.
3829 if (Res && Res->getDeclContext() != CurContext)
3832 // If not forward referenced or defined already, create the backing decl.
3833 Res = LabelDecl::Create(Context, CurContext, Loc, II);
3834 Scope *S = CurScope->getFnParent();
3835 assert(S && "Not in a function?");
3836 PushOnScopeChains(Res, S, true);
3838 return cast<LabelDecl>(Res);
3841 //===----------------------------------------------------------------------===//
3843 //===----------------------------------------------------------------------===//
3845 static bool isCandidateViable(CorrectionCandidateCallback &CCC,
3846 TypoCorrection &Candidate) {
3847 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
3848 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
3851 static void LookupPotentialTypoResult(Sema &SemaRef,
3853 IdentifierInfo *Name,
3854 Scope *S, CXXScopeSpec *SS,
3855 DeclContext *MemberContext,
3856 bool EnteringContext,
3857 bool isObjCIvarLookup,
3860 /// Check whether the declarations found for a typo correction are
3861 /// visible. Set the correction's RequiresImport flag to true if none of the
3862 /// declarations are visible, false otherwise.
3863 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
3864 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
3866 for (/**/; DI != DE; ++DI)
3867 if (!LookupResult::isVisible(SemaRef, *DI))
3869 // No filtering needed if all decls are visible.
3871 TC.setRequiresImport(false);
3875 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
3876 bool AnyVisibleDecls = !NewDecls.empty();
3878 for (/**/; DI != DE; ++DI) {
3879 if (LookupResult::isVisible(SemaRef, *DI)) {
3880 if (!AnyVisibleDecls) {
3881 // Found a visible decl, discard all hidden ones.
3882 AnyVisibleDecls = true;
3885 NewDecls.push_back(*DI);
3886 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
3887 NewDecls.push_back(*DI);
3890 if (NewDecls.empty())
3891 TC = TypoCorrection();
3893 TC.setCorrectionDecls(NewDecls);
3894 TC.setRequiresImport(!AnyVisibleDecls);
3898 // Fill the supplied vector with the IdentifierInfo pointers for each piece of
3899 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
3900 // fill the vector with the IdentifierInfo pointers for "foo" and "bar").
3901 static void getNestedNameSpecifierIdentifiers(
3902 NestedNameSpecifier *NNS,
3903 SmallVectorImpl<const IdentifierInfo*> &Identifiers) {
3904 if (NestedNameSpecifier *Prefix = NNS->getPrefix())
3905 getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
3907 Identifiers.clear();
3909 const IdentifierInfo *II = nullptr;
3911 switch (NNS->getKind()) {
3912 case NestedNameSpecifier::Identifier:
3913 II = NNS->getAsIdentifier();
3916 case NestedNameSpecifier::Namespace:
3917 if (NNS->getAsNamespace()->isAnonymousNamespace())
3919 II = NNS->getAsNamespace()->getIdentifier();
3922 case NestedNameSpecifier::NamespaceAlias:
3923 II = NNS->getAsNamespaceAlias()->getIdentifier();
3926 case NestedNameSpecifier::TypeSpecWithTemplate:
3927 case NestedNameSpecifier::TypeSpec:
3928 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier();
3931 case NestedNameSpecifier::Global:
3932 case NestedNameSpecifier::Super:
3937 Identifiers.push_back(II);
3940 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
3941 DeclContext *Ctx, bool InBaseClass) {
3942 // Don't consider hidden names for typo correction.
3946 // Only consider entities with identifiers for names, ignoring
3947 // special names (constructors, overloaded operators, selectors,
3949 IdentifierInfo *Name = ND->getIdentifier();
3953 // Only consider visible declarations and declarations from modules with
3954 // names that exactly match.
3955 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo)
3958 FoundName(Name->getName());
3961 void TypoCorrectionConsumer::FoundName(StringRef Name) {
3962 // Compute the edit distance between the typo and the name of this
3963 // entity, and add the identifier to the list of results.
3964 addName(Name, nullptr);
3967 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) {
3968 // Compute the edit distance between the typo and this keyword,
3969 // and add the keyword to the list of results.
3970 addName(Keyword, nullptr, nullptr, true);
3973 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
3974 NestedNameSpecifier *NNS, bool isKeyword) {
3975 // Use a simple length-based heuristic to determine the minimum possible
3976 // edit distance. If the minimum isn't good enough, bail out early.
3977 StringRef TypoStr = Typo->getName();
3978 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
3979 if (MinED && TypoStr.size() / MinED < 3)
3982 // Compute an upper bound on the allowable edit distance, so that the
3983 // edit-distance algorithm can short-circuit.
3984 unsigned UpperBound = (TypoStr.size() + 2) / 3;
3985 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
3986 if (ED > UpperBound) return;
3988 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
3989 if (isKeyword) TC.makeKeyword();
3990 TC.setCorrectionRange(nullptr, Result.getLookupNameInfo());
3994 static const unsigned MaxTypoDistanceResultSets = 5;
3996 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) {
3997 StringRef TypoStr = Typo->getName();
3998 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
4000 // For very short typos, ignore potential corrections that have a different
4001 // base identifier from the typo or which have a normalized edit distance
4002 // longer than the typo itself.
4003 if (TypoStr.size() < 3 &&
4004 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
4007 // If the correction is resolved but is not viable, ignore it.
4008 if (Correction.isResolved()) {
4009 checkCorrectionVisibility(SemaRef, Correction);
4010 if (!Correction || !isCandidateViable(*CorrectionValidator, Correction))
4014 TypoResultList &CList =
4015 CorrectionResults[Correction.getEditDistance(false)][Name];
4017 if (!CList.empty() && !CList.back().isResolved())
4019 if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
4020 std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts());
4021 for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end();
4022 RI != RIEnd; ++RI) {
4023 // If the Correction refers to a decl already in the result list,
4024 // replace the existing result if the string representation of Correction
4025 // comes before the current result alphabetically, then stop as there is
4026 // nothing more to be done to add Correction to the candidate set.
4027 if (RI->getCorrectionDecl() == NewND) {
4028 if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts()))
4034 if (CList.empty() || Correction.isResolved())
4035 CList.push_back(Correction);
4037 while (CorrectionResults.size() > MaxTypoDistanceResultSets)
4038 CorrectionResults.erase(std::prev(CorrectionResults.end()));
4041 void TypoCorrectionConsumer::addNamespaces(
4042 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
4043 SearchNamespaces = true;
4045 for (auto KNPair : KnownNamespaces)
4046 Namespaces.addNameSpecifier(KNPair.first);
4048 bool SSIsTemplate = false;
4049 if (NestedNameSpecifier *NNS =
4050 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) {
4051 if (const Type *T = NNS->getAsType())
4052 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization;
4054 // Do not transform this into an iterator-based loop. The loop body can
4055 // trigger the creation of further types (through lazy deserialization) and
4056 // invalid iterators into this list.
4057 auto &Types = SemaRef.getASTContext().getTypes();
4058 for (unsigned I = 0; I != Types.size(); ++I) {
4059 const auto *TI = Types[I];
4060 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
4061 CD = CD->getCanonicalDecl();
4062 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
4063 !CD->isUnion() && CD->getIdentifier() &&
4064 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
4065 (CD->isBeingDefined() || CD->isCompleteDefinition()))
4066 Namespaces.addNameSpecifier(CD);
4071 const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() {
4072 if (++CurrentTCIndex < ValidatedCorrections.size())
4073 return ValidatedCorrections[CurrentTCIndex];
4075 CurrentTCIndex = ValidatedCorrections.size();
4076 while (!CorrectionResults.empty()) {
4077 auto DI = CorrectionResults.begin();
4078 if (DI->second.empty()) {
4079 CorrectionResults.erase(DI);
4083 auto RI = DI->second.begin();
4084 if (RI->second.empty()) {
4085 DI->second.erase(RI);
4086 performQualifiedLookups();
4090 TypoCorrection TC = RI->second.pop_back_val();
4091 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) {
4092 ValidatedCorrections.push_back(TC);
4093 return ValidatedCorrections[CurrentTCIndex];
4096 return ValidatedCorrections[0]; // The empty correction.
4099 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
4100 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
4101 DeclContext *TempMemberContext = MemberContext;
4102 CXXScopeSpec *TempSS = SS.get();
4104 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
4106 CorrectionValidator->IsObjCIvarLookup,
4107 Name == Typo && !Candidate.WillReplaceSpecifier());
4108 switch (Result.getResultKind()) {
4109 case LookupResult::NotFound:
4110 case LookupResult::NotFoundInCurrentInstantiation:
4111 case LookupResult::FoundUnresolvedValue:
4113 // Immediately retry the lookup without the given CXXScopeSpec
4115 Candidate.WillReplaceSpecifier(true);
4118 if (TempMemberContext) {
4121 TempMemberContext = nullptr;
4124 if (SearchNamespaces)
4125 QualifiedResults.push_back(Candidate);
4128 case LookupResult::Ambiguous:
4129 // We don't deal with ambiguities.
4132 case LookupResult::Found:
4133 case LookupResult::FoundOverloaded:
4134 // Store all of the Decls for overloaded symbols
4135 for (auto *TRD : Result)
4136 Candidate.addCorrectionDecl(TRD);
4137 checkCorrectionVisibility(SemaRef, Candidate);
4138 if (!isCandidateViable(*CorrectionValidator, Candidate)) {
4139 if (SearchNamespaces)
4140 QualifiedResults.push_back(Candidate);
4143 Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4149 void TypoCorrectionConsumer::performQualifiedLookups() {
4150 unsigned TypoLen = Typo->getName().size();
4151 for (const TypoCorrection &QR : QualifiedResults) {
4152 for (const auto &NSI : Namespaces) {
4153 DeclContext *Ctx = NSI.DeclCtx;
4154 const Type *NSType = NSI.NameSpecifier->getAsType();
4156 // If the current NestedNameSpecifier refers to a class and the
4157 // current correction candidate is the name of that class, then skip
4158 // it as it is unlikely a qualified version of the class' constructor
4159 // is an appropriate correction.
4160 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() :
4162 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
4166 TypoCorrection TC(QR);
4167 TC.ClearCorrectionDecls();
4168 TC.setCorrectionSpecifier(NSI.NameSpecifier);
4169 TC.setQualifierDistance(NSI.EditDistance);
4170 TC.setCallbackDistance(0); // Reset the callback distance
4172 // If the current correction candidate and namespace combination are
4173 // too far away from the original typo based on the normalized edit
4174 // distance, then skip performing a qualified name lookup.
4175 unsigned TmpED = TC.getEditDistance(true);
4176 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4177 TypoLen / TmpED < 3)
4181 Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4182 if (!SemaRef.LookupQualifiedName(Result, Ctx))
4185 // Any corrections added below will be validated in subsequent
4186 // iterations of the main while() loop over the Consumer's contents.
4187 switch (Result.getResultKind()) {
4188 case LookupResult::Found:
4189 case LookupResult::FoundOverloaded: {
4190 if (SS && SS->isValid()) {
4191 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
4192 std::string OldQualified;
4193 llvm::raw_string_ostream OldOStream(OldQualified);
4194 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy());
4195 OldOStream << Typo->getName();
4196 // If correction candidate would be an identical written qualified
4197 // identifier, then the existing CXXScopeSpec probably included a
4198 // typedef that didn't get accounted for properly.
4199 if (OldOStream.str() == NewQualified)
4202 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4203 TRD != TRDEnd; ++TRD) {
4204 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
4205 NSType ? NSType->getAsCXXRecordDecl()
4207 TRD.getPair()) == Sema::AR_accessible)
4208 TC.addCorrectionDecl(*TRD);
4210 if (TC.isResolved()) {
4211 TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4216 case LookupResult::NotFound:
4217 case LookupResult::NotFoundInCurrentInstantiation:
4218 case LookupResult::Ambiguous:
4219 case LookupResult::FoundUnresolvedValue:
4224 QualifiedResults.clear();
4227 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4228 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4229 : Context(Context), CurContextChain(buildContextChain(CurContext)) {
4230 if (NestedNameSpecifier *NNS =
4231 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) {
4232 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4233 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4235 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
4237 // Build the list of identifiers that would be used for an absolute
4238 // (from the global context) NestedNameSpecifier referring to the current
4240 for (DeclContext *C : llvm::reverse(CurContextChain)) {
4241 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C))
4242 CurContextIdentifiers.push_back(ND->getIdentifier());
4245 // Add the global context as a NestedNameSpecifier
4246 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
4247 NestedNameSpecifier::GlobalSpecifier(Context), 1};
4248 DistanceMap[1].push_back(SI);
4251 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
4252 DeclContext *Start) -> DeclContextList {
4253 assert(Start && "Building a context chain from a null context");
4254 DeclContextList Chain;
4255 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
4256 DC = DC->getLookupParent()) {
4257 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
4258 if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
4259 !(ND && ND->isAnonymousNamespace()))
4260 Chain.push_back(DC->getPrimaryContext());
4266 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
4267 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) {
4268 unsigned NumSpecifiers = 0;
4269 for (DeclContext *C : llvm::reverse(DeclChain)) {
4270 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) {
4271 NNS = NestedNameSpecifier::Create(Context, NNS, ND);
4273 } else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) {
4274 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(),
4275 RD->getTypeForDecl());
4279 return NumSpecifiers;
4282 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
4284 NestedNameSpecifier *NNS = nullptr;
4285 unsigned NumSpecifiers = 0;
4286 DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
4287 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
4289 // Eliminate common elements from the two DeclContext chains.
4290 for (DeclContext *C : llvm::reverse(CurContextChain)) {
4291 if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C)
4293 NamespaceDeclChain.pop_back();
4296 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
4297 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
4299 // Add an explicit leading '::' specifier if needed.
4300 if (NamespaceDeclChain.empty()) {
4301 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4302 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4304 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4305 } else if (NamedDecl *ND =
4306 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
4307 IdentifierInfo *Name = ND->getIdentifier();
4308 bool SameNameSpecifier = false;
4309 if (std::find(CurNameSpecifierIdentifiers.begin(),
4310 CurNameSpecifierIdentifiers.end(),
4311 Name) != CurNameSpecifierIdentifiers.end()) {
4312 std::string NewNameSpecifier;
4313 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
4314 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
4315 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4316 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4317 SpecifierOStream.flush();
4318 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
4320 if (SameNameSpecifier ||
4321 std::find(CurContextIdentifiers.begin(), CurContextIdentifiers.end(),
4322 Name) != CurContextIdentifiers.end()) {
4323 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4324 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4326 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4330 // If the built NestedNameSpecifier would be replacing an existing
4331 // NestedNameSpecifier, use the number of component identifiers that
4332 // would need to be changed as the edit distance instead of the number
4333 // of components in the built NestedNameSpecifier.
4334 if (NNS && !CurNameSpecifierIdentifiers.empty()) {
4335 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
4336 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4337 NumSpecifiers = llvm::ComputeEditDistance(
4338 llvm::makeArrayRef(CurNameSpecifierIdentifiers),
4339 llvm::makeArrayRef(NewNameSpecifierIdentifiers));
4342 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
4343 DistanceMap[NumSpecifiers].push_back(SI);
4346 /// Perform name lookup for a possible result for typo correction.
4347 static void LookupPotentialTypoResult(Sema &SemaRef,
4349 IdentifierInfo *Name,
4350 Scope *S, CXXScopeSpec *SS,
4351 DeclContext *MemberContext,
4352 bool EnteringContext,
4353 bool isObjCIvarLookup,
4355 Res.suppressDiagnostics();
4357 Res.setLookupName(Name);
4358 Res.setAllowHidden(FindHidden);
4359 if (MemberContext) {
4360 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
4361 if (isObjCIvarLookup) {
4362 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
4369 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(
4370 Name, ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
4377 SemaRef.LookupQualifiedName(Res, MemberContext);
4381 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
4384 // Fake ivar lookup; this should really be part of
4385 // LookupParsedName.
4386 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
4387 if (Method->isInstanceMethod() && Method->getClassInterface() &&
4389 (Res.isSingleResult() &&
4390 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) {
4391 if (ObjCIvarDecl *IV
4392 = Method->getClassInterface()->lookupInstanceVariable(Name)) {
4400 /// Add keywords to the consumer as possible typo corrections.
4401 static void AddKeywordsToConsumer(Sema &SemaRef,
4402 TypoCorrectionConsumer &Consumer,
4403 Scope *S, CorrectionCandidateCallback &CCC,
4404 bool AfterNestedNameSpecifier) {
4405 if (AfterNestedNameSpecifier) {
4406 // For 'X::', we know exactly which keywords can appear next.
4407 Consumer.addKeywordResult("template");
4408 if (CCC.WantExpressionKeywords)
4409 Consumer.addKeywordResult("operator");
4413 if (CCC.WantObjCSuper)
4414 Consumer.addKeywordResult("super");
4416 if (CCC.WantTypeSpecifiers) {
4417 // Add type-specifier keywords to the set of results.
4418 static const char *const CTypeSpecs[] = {
4419 "char", "const", "double", "enum", "float", "int", "long", "short",
4420 "signed", "struct", "union", "unsigned", "void", "volatile",
4421 "_Complex", "_Imaginary",
4422 // storage-specifiers as well
4423 "extern", "inline", "static", "typedef"
4426 const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs);
4427 for (unsigned I = 0; I != NumCTypeSpecs; ++I)
4428 Consumer.addKeywordResult(CTypeSpecs[I]);
4430 if (SemaRef.getLangOpts().C99)
4431 Consumer.addKeywordResult("restrict");
4432 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
4433 Consumer.addKeywordResult("bool");
4434 else if (SemaRef.getLangOpts().C99)
4435 Consumer.addKeywordResult("_Bool");
4437 if (SemaRef.getLangOpts().CPlusPlus) {
4438 Consumer.addKeywordResult("class");
4439 Consumer.addKeywordResult("typename");
4440 Consumer.addKeywordResult("wchar_t");
4442 if (SemaRef.getLangOpts().CPlusPlus11) {
4443 Consumer.addKeywordResult("char16_t");
4444 Consumer.addKeywordResult("char32_t");
4445 Consumer.addKeywordResult("constexpr");
4446 Consumer.addKeywordResult("decltype");
4447 Consumer.addKeywordResult("thread_local");
4451 if (SemaRef.getLangOpts().GNUKeywords)
4452 Consumer.addKeywordResult("typeof");
4453 } else if (CCC.WantFunctionLikeCasts) {
4454 static const char *const CastableTypeSpecs[] = {
4455 "char", "double", "float", "int", "long", "short",
4456 "signed", "unsigned", "void"
4458 for (auto *kw : CastableTypeSpecs)
4459 Consumer.addKeywordResult(kw);
4462 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
4463 Consumer.addKeywordResult("const_cast");
4464 Consumer.addKeywordResult("dynamic_cast");
4465 Consumer.addKeywordResult("reinterpret_cast");
4466 Consumer.addKeywordResult("static_cast");
4469 if (CCC.WantExpressionKeywords) {
4470 Consumer.addKeywordResult("sizeof");
4471 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
4472 Consumer.addKeywordResult("false");
4473 Consumer.addKeywordResult("true");
4476 if (SemaRef.getLangOpts().CPlusPlus) {
4477 static const char *const CXXExprs[] = {
4478 "delete", "new", "operator", "throw", "typeid"
4480 const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs);
4481 for (unsigned I = 0; I != NumCXXExprs; ++I)
4482 Consumer.addKeywordResult(CXXExprs[I]);
4484 if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
4485 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
4486 Consumer.addKeywordResult("this");
4488 if (SemaRef.getLangOpts().CPlusPlus11) {
4489 Consumer.addKeywordResult("alignof");
4490 Consumer.addKeywordResult("nullptr");
4494 if (SemaRef.getLangOpts().C11) {
4495 // FIXME: We should not suggest _Alignof if the alignof macro
4497 Consumer.addKeywordResult("_Alignof");
4501 if (CCC.WantRemainingKeywords) {
4502 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
4504 static const char *const CStmts[] = {
4505 "do", "else", "for", "goto", "if", "return", "switch", "while" };
4506 const unsigned NumCStmts = llvm::array_lengthof(CStmts);
4507 for (unsigned I = 0; I != NumCStmts; ++I)
4508 Consumer.addKeywordResult(CStmts[I]);
4510 if (SemaRef.getLangOpts().CPlusPlus) {
4511 Consumer.addKeywordResult("catch");
4512 Consumer.addKeywordResult("try");
4515 if (S && S->getBreakParent())
4516 Consumer.addKeywordResult("break");
4518 if (S && S->getContinueParent())
4519 Consumer.addKeywordResult("continue");
4521 if (SemaRef.getCurFunction() &&
4522 !SemaRef.getCurFunction()->SwitchStack.empty()) {
4523 Consumer.addKeywordResult("case");
4524 Consumer.addKeywordResult("default");
4527 if (SemaRef.getLangOpts().CPlusPlus) {
4528 Consumer.addKeywordResult("namespace");
4529 Consumer.addKeywordResult("template");
4532 if (S && S->isClassScope()) {
4533 Consumer.addKeywordResult("explicit");
4534 Consumer.addKeywordResult("friend");
4535 Consumer.addKeywordResult("mutable");
4536 Consumer.addKeywordResult("private");
4537 Consumer.addKeywordResult("protected");
4538 Consumer.addKeywordResult("public");
4539 Consumer.addKeywordResult("virtual");
4543 if (SemaRef.getLangOpts().CPlusPlus) {
4544 Consumer.addKeywordResult("using");
4546 if (SemaRef.getLangOpts().CPlusPlus11)
4547 Consumer.addKeywordResult("static_assert");
4552 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
4553 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4554 Scope *S, CXXScopeSpec *SS,
4555 std::unique_ptr<CorrectionCandidateCallback> CCC,
4556 DeclContext *MemberContext, bool EnteringContext,
4557 const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
4559 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
4560 DisableTypoCorrection)
4563 // In Microsoft mode, don't perform typo correction in a template member
4564 // function dependent context because it interferes with the "lookup into
4565 // dependent bases of class templates" feature.
4566 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
4567 isa<CXXMethodDecl>(CurContext))
4570 // We only attempt to correct typos for identifiers.
4571 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4575 // If the scope specifier itself was invalid, don't try to correct
4577 if (SS && SS->isInvalid())
4580 // Never try to correct typos during any kind of code synthesis.
4581 if (!CodeSynthesisContexts.empty())
4584 // Don't try to correct 'super'.
4585 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
4588 // Abort if typo correction already failed for this specific typo.
4589 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
4590 if (locs != TypoCorrectionFailures.end() &&
4591 locs->second.count(TypoName.getLoc()))
4594 // Don't try to correct the identifier "vector" when in AltiVec mode.
4595 // TODO: Figure out why typo correction misbehaves in this case, fix it, and
4596 // remove this workaround.
4597 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector"))
4600 // Provide a stop gap for files that are just seriously broken. Trying
4601 // to correct all typos can turn into a HUGE performance penalty, causing
4602 // some files to take minutes to get rejected by the parser.
4603 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
4604 if (Limit && TyposCorrected >= Limit)
4608 // If we're handling a missing symbol error, using modules, and the
4609 // special search all modules option is used, look for a missing import.
4610 if (ErrorRecovery && getLangOpts().Modules &&
4611 getLangOpts().ModulesSearchAll) {
4612 // The following has the side effect of loading the missing module.
4613 getModuleLoader().lookupMissingImports(Typo->getName(),
4614 TypoName.getBeginLoc());
4617 CorrectionCandidateCallback &CCCRef = *CCC;
4618 auto Consumer = llvm::make_unique<TypoCorrectionConsumer>(
4619 *this, TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4622 // Perform name lookup to find visible, similarly-named entities.
4623 bool IsUnqualifiedLookup = false;
4624 DeclContext *QualifiedDC = MemberContext;
4625 if (MemberContext) {
4626 LookupVisibleDecls(MemberContext, LookupKind, *Consumer);
4628 // Look in qualified interfaces.
4630 for (auto *I : OPT->quals())
4631 LookupVisibleDecls(I, LookupKind, *Consumer);
4633 } else if (SS && SS->isSet()) {
4634 QualifiedDC = computeDeclContext(*SS, EnteringContext);
4638 LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer);
4640 IsUnqualifiedLookup = true;
4643 // Determine whether we are going to search in the various namespaces for
4645 bool SearchNamespaces
4646 = getLangOpts().CPlusPlus &&
4647 (IsUnqualifiedLookup || (SS && SS->isSet()));
4649 if (IsUnqualifiedLookup || SearchNamespaces) {
4650 // For unqualified lookup, look through all of the names that we have
4651 // seen in this translation unit.
4652 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4653 for (const auto &I : Context.Idents)
4654 Consumer->FoundName(I.getKey());
4656 // Walk through identifiers in external identifier sources.
4657 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4658 if (IdentifierInfoLookup *External
4659 = Context.Idents.getExternalIdentifierLookup()) {
4660 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4662 StringRef Name = Iter->Next();
4666 Consumer->FoundName(Name);
4671 AddKeywordsToConsumer(*this, *Consumer, S, CCCRef, SS && SS->isNotEmpty());
4673 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
4674 // to search those namespaces.
4675 if (SearchNamespaces) {
4676 // Load any externally-known namespaces.
4677 if (ExternalSource && !LoadedExternalKnownNamespaces) {
4678 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
4679 LoadedExternalKnownNamespaces = true;
4680 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
4681 for (auto *N : ExternalKnownNamespaces)
4682 KnownNamespaces[N] = true;
4685 Consumer->addNamespaces(KnownNamespaces);
4691 /// Try to "correct" a typo in the source code by finding
4692 /// visible declarations whose names are similar to the name that was
4693 /// present in the source code.
4695 /// \param TypoName the \c DeclarationNameInfo structure that contains
4696 /// the name that was present in the source code along with its location.
4698 /// \param LookupKind the name-lookup criteria used to search for the name.
4700 /// \param S the scope in which name lookup occurs.
4702 /// \param SS the nested-name-specifier that precedes the name we're
4703 /// looking for, if present.
4705 /// \param CCC A CorrectionCandidateCallback object that provides further
4706 /// validation of typo correction candidates. It also provides flags for
4707 /// determining the set of keywords permitted.
4709 /// \param MemberContext if non-NULL, the context in which to look for
4710 /// a member access expression.
4712 /// \param EnteringContext whether we're entering the context described by
4713 /// the nested-name-specifier SS.
4715 /// \param OPT when non-NULL, the search for visible declarations will
4716 /// also walk the protocols in the qualified interfaces of \p OPT.
4718 /// \returns a \c TypoCorrection containing the corrected name if the typo
4719 /// along with information such as the \c NamedDecl where the corrected name
4720 /// was declared, and any additional \c NestedNameSpecifier needed to access
4721 /// it (C++ only). The \c TypoCorrection is empty if there is no correction.
4722 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
4723 Sema::LookupNameKind LookupKind,
4724 Scope *S, CXXScopeSpec *SS,
4725 std::unique_ptr<CorrectionCandidateCallback> CCC,
4726 CorrectTypoKind Mode,
4727 DeclContext *MemberContext,
4728 bool EnteringContext,
4729 const ObjCObjectPointerType *OPT,
4730 bool RecordFailure) {
4731 assert(CCC && "CorrectTypo requires a CorrectionCandidateCallback");
4733 // Always let the ExternalSource have the first chance at correction, even
4734 // if we would otherwise have given up.
4735 if (ExternalSource) {
4736 if (TypoCorrection Correction = ExternalSource->CorrectTypo(
4737 TypoName, LookupKind, S, SS, *CCC, MemberContext, EnteringContext, OPT))
4741 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
4742 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
4743 // some instances of CTC_Unknown, while WantRemainingKeywords is true
4744 // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
4745 bool ObjCMessageReceiver = CCC->WantObjCSuper && !CCC->WantRemainingKeywords;
4747 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4748 auto Consumer = makeTypoCorrectionConsumer(
4749 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4750 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4753 return TypoCorrection();
4755 // If we haven't found anything, we're done.
4756 if (Consumer->empty())
4757 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4759 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4760 // is not more that about a third of the length of the typo's identifier.
4761 unsigned ED = Consumer->getBestEditDistance(true);
4762 unsigned TypoLen = Typo->getName().size();
4763 if (ED > 0 && TypoLen / ED < 3)
4764 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4766 TypoCorrection BestTC = Consumer->getNextCorrection();
4767 TypoCorrection SecondBestTC = Consumer->getNextCorrection();
4769 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4771 ED = BestTC.getEditDistance();
4773 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
4774 // If this was an unqualified lookup and we believe the callback
4775 // object wouldn't have filtered out possible corrections, note
4776 // that no correction was found.
4777 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4780 // If only a single name remains, return that result.
4781 if (!SecondBestTC ||
4782 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
4783 const TypoCorrection &Result = BestTC;
4785 // Don't correct to a keyword that's the same as the typo; the keyword
4786 // wasn't actually in scope.
4787 if (ED == 0 && Result.isKeyword())
4788 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4790 TypoCorrection TC = Result;
4791 TC.setCorrectionRange(SS, TypoName);
4792 checkCorrectionVisibility(*this, TC);
4794 } else if (SecondBestTC && ObjCMessageReceiver) {
4795 // Prefer 'super' when we're completing in a message-receiver
4798 if (BestTC.getCorrection().getAsString() != "super") {
4799 if (SecondBestTC.getCorrection().getAsString() == "super")
4800 BestTC = SecondBestTC;
4801 else if ((*Consumer)["super"].front().isKeyword())
4802 BestTC = (*Consumer)["super"].front();
4804 // Don't correct to a keyword that's the same as the typo; the keyword
4805 // wasn't actually in scope.
4806 if (BestTC.getEditDistance() == 0 ||
4807 BestTC.getCorrection().getAsString() != "super")
4808 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4810 BestTC.setCorrectionRange(SS, TypoName);
4814 // Record the failure's location if needed and return an empty correction. If
4815 // this was an unqualified lookup and we believe the callback object did not
4816 // filter out possible corrections, also cache the failure for the typo.
4817 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC);
4820 /// Try to "correct" a typo in the source code by finding
4821 /// visible declarations whose names are similar to the name that was
4822 /// present in the source code.
4824 /// \param TypoName the \c DeclarationNameInfo structure that contains
4825 /// the name that was present in the source code along with its location.
4827 /// \param LookupKind the name-lookup criteria used to search for the name.
4829 /// \param S the scope in which name lookup occurs.
4831 /// \param SS the nested-name-specifier that precedes the name we're
4832 /// looking for, if present.
4834 /// \param CCC A CorrectionCandidateCallback object that provides further
4835 /// validation of typo correction candidates. It also provides flags for
4836 /// determining the set of keywords permitted.
4838 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print
4839 /// diagnostics when the actual typo correction is attempted.
4841 /// \param TRC A TypoRecoveryCallback functor that will be used to build an
4842 /// Expr from a typo correction candidate.
4844 /// \param MemberContext if non-NULL, the context in which to look for
4845 /// a member access expression.
4847 /// \param EnteringContext whether we're entering the context described by
4848 /// the nested-name-specifier SS.
4850 /// \param OPT when non-NULL, the search for visible declarations will
4851 /// also walk the protocols in the qualified interfaces of \p OPT.
4853 /// \returns a new \c TypoExpr that will later be replaced in the AST with an
4854 /// Expr representing the result of performing typo correction, or nullptr if
4855 /// typo correction is not possible. If nullptr is returned, no diagnostics will
4856 /// be emitted and it is the responsibility of the caller to emit any that are
4858 TypoExpr *Sema::CorrectTypoDelayed(
4859 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4860 Scope *S, CXXScopeSpec *SS,
4861 std::unique_ptr<CorrectionCandidateCallback> CCC,
4862 TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode,
4863 DeclContext *MemberContext, bool EnteringContext,
4864 const ObjCObjectPointerType *OPT) {
4865 assert(CCC && "CorrectTypoDelayed requires a CorrectionCandidateCallback");
4867 auto Consumer = makeTypoCorrectionConsumer(
4868 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4869 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4871 // Give the external sema source a chance to correct the typo.
4872 TypoCorrection ExternalTypo;
4873 if (ExternalSource && Consumer) {
4874 ExternalTypo = ExternalSource->CorrectTypo(
4875 TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(),
4876 MemberContext, EnteringContext, OPT);
4878 Consumer->addCorrection(ExternalTypo);
4881 if (!Consumer || Consumer->empty())
4884 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4885 // is not more that about a third of the length of the typo's identifier.
4886 unsigned ED = Consumer->getBestEditDistance(true);
4887 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4888 if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3)
4891 ExprEvalContexts.back().NumTypos++;
4892 return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC));
4895 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) {
4899 CorrectionDecls.clear();
4901 CorrectionDecls.push_back(CDecl);
4903 if (!CorrectionName)
4904 CorrectionName = CDecl->getDeclName();
4907 std::string TypoCorrection::getAsString(const LangOptions &LO) const {
4908 if (CorrectionNameSpec) {
4909 std::string tmpBuffer;
4910 llvm::raw_string_ostream PrefixOStream(tmpBuffer);
4911 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO));
4912 PrefixOStream << CorrectionName;
4913 return PrefixOStream.str();
4916 return CorrectionName.getAsString();
4919 bool CorrectionCandidateCallback::ValidateCandidate(
4920 const TypoCorrection &candidate) {
4921 if (!candidate.isResolved())
4924 if (candidate.isKeyword())
4925 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
4926 WantRemainingKeywords || WantObjCSuper;
4928 bool HasNonType = false;
4929 bool HasStaticMethod = false;
4930 bool HasNonStaticMethod = false;
4931 for (Decl *D : candidate) {
4932 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
4933 D = FTD->getTemplatedDecl();
4934 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
4935 if (Method->isStatic())
4936 HasStaticMethod = true;
4938 HasNonStaticMethod = true;
4940 if (!isa<TypeDecl>(D))
4944 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
4945 !candidate.getCorrectionSpecifier())
4948 return WantTypeSpecifiers || HasNonType;
4951 FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs,
4952 bool HasExplicitTemplateArgs,
4954 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
4955 CurContext(SemaRef.CurContext), MemberFn(ME) {
4956 WantTypeSpecifiers = false;
4957 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && NumArgs == 1;
4958 WantRemainingKeywords = false;
4961 bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) {
4962 if (!candidate.getCorrectionDecl())
4963 return candidate.isKeyword();
4965 for (auto *C : candidate) {
4966 FunctionDecl *FD = nullptr;
4967 NamedDecl *ND = C->getUnderlyingDecl();
4968 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
4969 FD = FTD->getTemplatedDecl();
4970 if (!HasExplicitTemplateArgs && !FD) {
4971 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
4972 // If the Decl is neither a function nor a template function,
4973 // determine if it is a pointer or reference to a function. If so,
4974 // check against the number of arguments expected for the pointee.
4975 QualType ValType = cast<ValueDecl>(ND)->getType();
4976 if (ValType.isNull())
4978 if (ValType->isAnyPointerType() || ValType->isReferenceType())
4979 ValType = ValType->getPointeeType();
4980 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
4981 if (FPT->getNumParams() == NumArgs)
4986 // Skip the current candidate if it is not a FunctionDecl or does not accept
4987 // the current number of arguments.
4988 if (!FD || !(FD->getNumParams() >= NumArgs &&
4989 FD->getMinRequiredArguments() <= NumArgs))
4992 // If the current candidate is a non-static C++ method, skip the candidate
4993 // unless the method being corrected--or the current DeclContext, if the
4994 // function being corrected is not a method--is a method in the same class
4995 // or a descendent class of the candidate's parent class.
4996 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
4997 if (MemberFn || !MD->isStatic()) {
4998 CXXMethodDecl *CurMD =
5000 ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl())
5001 : dyn_cast_or_null<CXXMethodDecl>(CurContext);
5002 CXXRecordDecl *CurRD =
5003 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
5004 CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
5005 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
5014 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5015 const PartialDiagnostic &TypoDiag,
5016 bool ErrorRecovery) {
5017 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
5021 /// Find which declaration we should import to provide the definition of
5022 /// the given declaration.
5023 static NamedDecl *getDefinitionToImport(NamedDecl *D) {
5024 if (VarDecl *VD = dyn_cast<VarDecl>(D))
5025 return VD->getDefinition();
5026 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
5027 return FD->getDefinition();
5028 if (TagDecl *TD = dyn_cast<TagDecl>(D))
5029 return TD->getDefinition();
5030 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
5031 return ID->getDefinition();
5032 if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
5033 return PD->getDefinition();
5034 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
5035 return getDefinitionToImport(TD->getTemplatedDecl());
5039 void Sema::diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl,
5040 MissingImportKind MIK, bool Recover) {
5041 // Suggest importing a module providing the definition of this entity, if
5043 NamedDecl *Def = getDefinitionToImport(Decl);
5047 Module *Owner = getOwningModule(Def);
5048 assert(Owner && "definition of hidden declaration is not in a module");
5050 llvm::SmallVector<Module*, 8> OwningModules;
5051 OwningModules.push_back(Owner);
5052 auto Merged = Context.getModulesWithMergedDefinition(Def);
5053 OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end());
5055 diagnoseMissingImport(Loc, Decl, Decl->getLocation(), OwningModules, MIK,
5059 /// Get a "quoted.h" or <angled.h> include path to use in a diagnostic
5060 /// suggesting the addition of a #include of the specified file.
5061 static std::string getIncludeStringForHeader(Preprocessor &PP,
5062 const FileEntry *E) {
5065 PP.getHeaderSearchInfo().suggestPathToFileForDiagnostics(E, &IsSystem);
5066 return (IsSystem ? '<' : '"') + Path + (IsSystem ? '>' : '"');
5069 void Sema::diagnoseMissingImport(SourceLocation UseLoc, NamedDecl *Decl,
5070 SourceLocation DeclLoc,
5071 ArrayRef<Module *> Modules,
5072 MissingImportKind MIK, bool Recover) {
5073 assert(!Modules.empty());
5075 // Weed out duplicates from module list.
5076 llvm::SmallVector<Module*, 8> UniqueModules;
5077 llvm::SmallDenseSet<Module*, 8> UniqueModuleSet;
5078 for (auto *M : Modules)
5079 if (UniqueModuleSet.insert(M).second)
5080 UniqueModules.push_back(M);
5081 Modules = UniqueModules;
5083 if (Modules.size() > 1) {
5084 std::string ModuleList;
5086 for (Module *M : Modules) {
5087 ModuleList += "\n ";
5088 if (++N == 5 && N != Modules.size()) {
5089 ModuleList += "[...]";
5092 ModuleList += M->getFullModuleName();
5095 Diag(UseLoc, diag::err_module_unimported_use_multiple)
5096 << (int)MIK << Decl << ModuleList;
5097 } else if (const FileEntry *E = PP.getModuleHeaderToIncludeForDiagnostics(
5098 UseLoc, Modules[0], DeclLoc)) {
5099 // The right way to make the declaration visible is to include a header;
5100 // suggest doing so.
5102 // FIXME: Find a smart place to suggest inserting a #include, and add
5103 // a FixItHint there.
5104 Diag(UseLoc, diag::err_module_unimported_use_header)
5105 << (int)MIK << Decl << Modules[0]->getFullModuleName()
5106 << getIncludeStringForHeader(PP, E);
5108 // FIXME: Add a FixItHint that imports the corresponding module.
5109 Diag(UseLoc, diag::err_module_unimported_use)
5110 << (int)MIK << Decl << Modules[0]->getFullModuleName();
5115 case MissingImportKind::Declaration:
5116 DiagID = diag::note_previous_declaration;
5118 case MissingImportKind::Definition:
5119 DiagID = diag::note_previous_definition;
5121 case MissingImportKind::DefaultArgument:
5122 DiagID = diag::note_default_argument_declared_here;
5124 case MissingImportKind::ExplicitSpecialization:
5125 DiagID = diag::note_explicit_specialization_declared_here;
5127 case MissingImportKind::PartialSpecialization:
5128 DiagID = diag::note_partial_specialization_declared_here;
5131 Diag(DeclLoc, DiagID);
5133 // Try to recover by implicitly importing this module.
5135 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5138 /// Diagnose a successfully-corrected typo. Separated from the correction
5139 /// itself to allow external validation of the result, etc.
5141 /// \param Correction The result of performing typo correction.
5142 /// \param TypoDiag The diagnostic to produce. This will have the corrected
5143 /// string added to it (and usually also a fixit).
5144 /// \param PrevNote A note to use when indicating the location of the entity to
5145 /// which we are correcting. Will have the correction string added to it.
5146 /// \param ErrorRecovery If \c true (the default), the caller is going to
5147 /// recover from the typo as if the corrected string had been typed.
5148 /// In this case, \c PDiag must be an error, and we will attach a fixit
5150 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5151 const PartialDiagnostic &TypoDiag,
5152 const PartialDiagnostic &PrevNote,
5153 bool ErrorRecovery) {
5154 std::string CorrectedStr = Correction.getAsString(getLangOpts());
5155 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
5156 FixItHint FixTypo = FixItHint::CreateReplacement(
5157 Correction.getCorrectionRange(), CorrectedStr);
5159 // Maybe we're just missing a module import.
5160 if (Correction.requiresImport()) {
5161 NamedDecl *Decl = Correction.getFoundDecl();
5162 assert(Decl && "import required but no declaration to import");
5164 diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl,
5165 MissingImportKind::Declaration, ErrorRecovery);
5169 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
5170 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
5172 NamedDecl *ChosenDecl =
5173 Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
5174 if (PrevNote.getDiagID() && ChosenDecl)
5175 Diag(ChosenDecl->getLocation(), PrevNote)
5176 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
5178 // Add any extra diagnostics.
5179 for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
5180 Diag(Correction.getCorrectionRange().getBegin(), PD);
5183 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
5184 TypoDiagnosticGenerator TDG,
5185 TypoRecoveryCallback TRC) {
5186 assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer");
5187 auto TE = new (Context) TypoExpr(Context.DependentTy);
5188 auto &State = DelayedTypos[TE];
5189 State.Consumer = std::move(TCC);
5190 State.DiagHandler = std::move(TDG);
5191 State.RecoveryHandler = std::move(TRC);
5195 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const {
5196 auto Entry = DelayedTypos.find(TE);
5197 assert(Entry != DelayedTypos.end() &&
5198 "Failed to get the state for a TypoExpr!");
5199 return Entry->second;
5202 void Sema::clearDelayedTypo(TypoExpr *TE) {
5203 DelayedTypos.erase(TE);
5206 void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) {
5207 DeclarationNameInfo Name(II, IILoc);
5208 LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration);
5209 R.suppressDiagnostics();
5210 R.setHideTags(false);