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 {
91 typedef SmallVector<UnqualUsingEntry, 8> ListTy;
94 llvm::SmallPtrSet<DeclContext*, 8> visited;
97 UnqualUsingDirectiveSet() {}
99 void visitScopeChain(Scope *S, Scope *InnermostFileScope) {
100 // C++ [namespace.udir]p1:
101 // During unqualified name lookup, the names appear as if they
102 // were declared in the nearest enclosing namespace which contains
103 // both the using-directive and the nominated namespace.
104 DeclContext *InnermostFileDC = InnermostFileScope->getEntity();
105 assert(InnermostFileDC && InnermostFileDC->isFileContext());
107 for (; S; S = S->getParent()) {
108 // C++ [namespace.udir]p1:
109 // A using-directive shall not appear in class scope, but may
110 // appear in namespace scope or in block scope.
111 DeclContext *Ctx = S->getEntity();
112 if (Ctx && Ctx->isFileContext()) {
114 } else if (!Ctx || Ctx->isFunctionOrMethod()) {
115 for (auto *I : S->using_directives())
116 visit(I, InnermostFileDC);
121 // Visits a context and collect all of its using directives
122 // recursively. Treats all using directives as if they were
123 // declared in the context.
125 // A given context is only every visited once, so it is important
126 // that contexts be visited from the inside out in order to get
127 // the effective DCs right.
128 void visit(DeclContext *DC, DeclContext *EffectiveDC) {
129 if (!visited.insert(DC).second)
132 addUsingDirectives(DC, EffectiveDC);
135 // Visits a using directive and collects all of its using
136 // directives recursively. Treats all using directives as if they
137 // were declared in the effective DC.
138 void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
139 DeclContext *NS = UD->getNominatedNamespace();
140 if (!visited.insert(NS).second)
143 addUsingDirective(UD, EffectiveDC);
144 addUsingDirectives(NS, EffectiveDC);
147 // Adds all the using directives in a context (and those nominated
148 // by its using directives, transitively) as if they appeared in
149 // the given effective context.
150 void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) {
151 SmallVector<DeclContext*, 4> queue;
153 for (auto UD : DC->using_directives()) {
154 DeclContext *NS = UD->getNominatedNamespace();
155 if (visited.insert(NS).second) {
156 addUsingDirective(UD, EffectiveDC);
164 DC = queue.pop_back_val();
168 // Add a using directive as if it had been declared in the given
169 // context. This helps implement C++ [namespace.udir]p3:
170 // The using-directive is transitive: if a scope contains a
171 // using-directive that nominates a second namespace that itself
172 // contains using-directives, the effect is as if the
173 // using-directives from the second namespace also appeared in
175 void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) {
176 // Find the common ancestor between the effective context and
177 // the nominated namespace.
178 DeclContext *Common = UD->getNominatedNamespace();
179 while (!Common->Encloses(EffectiveDC))
180 Common = Common->getParent();
181 Common = Common->getPrimaryContext();
183 list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common));
187 std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator());
190 typedef ListTy::const_iterator const_iterator;
192 const_iterator begin() const { return list.begin(); }
193 const_iterator end() const { return list.end(); }
195 llvm::iterator_range<const_iterator>
196 getNamespacesFor(DeclContext *DC) const {
197 return llvm::make_range(std::equal_range(begin(), end(),
198 DC->getPrimaryContext(),
199 UnqualUsingEntry::Comparator()));
202 } // end anonymous namespace
204 // Retrieve the set of identifier namespaces that correspond to a
205 // specific kind of name lookup.
206 static inline unsigned getIDNS(Sema::LookupNameKind NameKind,
208 bool Redeclaration) {
211 case Sema::LookupObjCImplicitSelfParam:
212 case Sema::LookupOrdinaryName:
213 case Sema::LookupRedeclarationWithLinkage:
214 case Sema::LookupLocalFriendName:
215 IDNS = Decl::IDNS_Ordinary;
217 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace;
219 IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend;
222 IDNS |= Decl::IDNS_LocalExtern;
225 case Sema::LookupOperatorName:
226 // Operator lookup is its own crazy thing; it is not the same
227 // as (e.g.) looking up an operator name for redeclaration.
228 assert(!Redeclaration && "cannot do redeclaration operator lookup");
229 IDNS = Decl::IDNS_NonMemberOperator;
232 case Sema::LookupTagName:
234 IDNS = Decl::IDNS_Type;
236 // When looking for a redeclaration of a tag name, we add:
237 // 1) TagFriend to find undeclared friend decls
238 // 2) Namespace because they can't "overload" with tag decls.
239 // 3) Tag because it includes class templates, which can't
240 // "overload" with tag decls.
242 IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace;
244 IDNS = Decl::IDNS_Tag;
248 case Sema::LookupLabel:
249 IDNS = Decl::IDNS_Label;
252 case Sema::LookupMemberName:
253 IDNS = Decl::IDNS_Member;
255 IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary;
258 case Sema::LookupNestedNameSpecifierName:
259 IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace;
262 case Sema::LookupNamespaceName:
263 IDNS = Decl::IDNS_Namespace;
266 case Sema::LookupUsingDeclName:
267 assert(Redeclaration && "should only be used for redecl lookup");
268 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member |
269 Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend |
270 Decl::IDNS_LocalExtern;
273 case Sema::LookupObjCProtocolName:
274 IDNS = Decl::IDNS_ObjCProtocol;
277 case Sema::LookupOMPReductionName:
278 IDNS = Decl::IDNS_OMPReduction;
281 case Sema::LookupAnyName:
282 IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member
283 | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol
290 void LookupResult::configure() {
291 IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus,
292 isForRedeclaration());
294 // If we're looking for one of the allocation or deallocation
295 // operators, make sure that the implicitly-declared new and delete
296 // operators can be found.
297 switch (NameInfo.getName().getCXXOverloadedOperator()) {
301 case OO_Array_Delete:
302 getSema().DeclareGlobalNewDelete();
309 // Compiler builtins are always visible, regardless of where they end
310 // up being declared.
311 if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) {
312 if (unsigned BuiltinID = Id->getBuiltinID()) {
313 if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
319 bool LookupResult::sanity() const {
320 // This function is never called by NDEBUG builds.
321 assert(ResultKind != NotFound || Decls.size() == 0);
322 assert(ResultKind != Found || Decls.size() == 1);
323 assert(ResultKind != FoundOverloaded || Decls.size() > 1 ||
324 (Decls.size() == 1 &&
325 isa<FunctionTemplateDecl>((*begin())->getUnderlyingDecl())));
326 assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved());
327 assert(ResultKind != Ambiguous || Decls.size() > 1 ||
328 (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects ||
329 Ambiguity == AmbiguousBaseSubobjectTypes)));
330 assert((Paths != nullptr) == (ResultKind == Ambiguous &&
331 (Ambiguity == AmbiguousBaseSubobjectTypes ||
332 Ambiguity == AmbiguousBaseSubobjects)));
336 // Necessary because CXXBasePaths is not complete in Sema.h
337 void LookupResult::deletePaths(CXXBasePaths *Paths) {
341 /// Get a representative context for a declaration such that two declarations
342 /// will have the same context if they were found within the same scope.
343 static DeclContext *getContextForScopeMatching(Decl *D) {
344 // For function-local declarations, use that function as the context. This
345 // doesn't account for scopes within the function; the caller must deal with
347 DeclContext *DC = D->getLexicalDeclContext();
348 if (DC->isFunctionOrMethod())
351 // Otherwise, look at the semantic context of the declaration. The
352 // declaration must have been found there.
353 return D->getDeclContext()->getRedeclContext();
356 /// \brief Determine whether \p D is a better lookup result than \p Existing,
357 /// given that they declare the same entity.
358 static bool isPreferredLookupResult(Sema &S, Sema::LookupNameKind Kind,
359 NamedDecl *D, NamedDecl *Existing) {
360 // When looking up redeclarations of a using declaration, prefer a using
361 // shadow declaration over any other declaration of the same entity.
362 if (Kind == Sema::LookupUsingDeclName && isa<UsingShadowDecl>(D) &&
363 !isa<UsingShadowDecl>(Existing))
366 auto *DUnderlying = D->getUnderlyingDecl();
367 auto *EUnderlying = Existing->getUnderlyingDecl();
369 // If they have different underlying declarations, prefer a typedef over the
370 // original type (this happens when two type declarations denote the same
371 // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef
372 // might carry additional semantic information, such as an alignment override.
373 // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag
374 // declaration over a typedef.
375 if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) {
376 assert(isa<TypeDecl>(DUnderlying) && isa<TypeDecl>(EUnderlying));
377 bool HaveTag = isa<TagDecl>(EUnderlying);
378 bool WantTag = Kind == Sema::LookupTagName;
379 return HaveTag != WantTag;
382 // Pick the function with more default arguments.
383 // FIXME: In the presence of ambiguous default arguments, we should keep both,
384 // so we can diagnose the ambiguity if the default argument is needed.
385 // See C++ [over.match.best]p3.
386 if (auto *DFD = dyn_cast<FunctionDecl>(DUnderlying)) {
387 auto *EFD = cast<FunctionDecl>(EUnderlying);
388 unsigned DMin = DFD->getMinRequiredArguments();
389 unsigned EMin = EFD->getMinRequiredArguments();
390 // If D has more default arguments, it is preferred.
393 // FIXME: When we track visibility for default function arguments, check
394 // that we pick the declaration with more visible default arguments.
397 // Pick the template with more default template arguments.
398 if (auto *DTD = dyn_cast<TemplateDecl>(DUnderlying)) {
399 auto *ETD = cast<TemplateDecl>(EUnderlying);
400 unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments();
401 unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments();
402 // If D has more default arguments, it is preferred. Note that default
403 // arguments (and their visibility) is monotonically increasing across the
404 // redeclaration chain, so this is a quick proxy for "is more recent".
407 // If D has more *visible* default arguments, it is preferred. Note, an
408 // earlier default argument being visible does not imply that a later
409 // default argument is visible, so we can't just check the first one.
410 for (unsigned I = DMin, N = DTD->getTemplateParameters()->size();
412 if (!S.hasVisibleDefaultArgument(
413 ETD->getTemplateParameters()->getParam(I)) &&
414 S.hasVisibleDefaultArgument(
415 DTD->getTemplateParameters()->getParam(I)))
420 // VarDecl can have incomplete array types, prefer the one with more complete
422 if (VarDecl *DVD = dyn_cast<VarDecl>(DUnderlying)) {
423 VarDecl *EVD = cast<VarDecl>(EUnderlying);
424 if (EVD->getType()->isIncompleteType() &&
425 !DVD->getType()->isIncompleteType()) {
426 // Prefer the decl with a more complete type if visible.
427 return S.isVisible(DVD);
429 return false; // Avoid picking up a newer decl, just because it was newer.
432 // For most kinds of declaration, it doesn't really matter which one we pick.
433 if (!isa<FunctionDecl>(DUnderlying) && !isa<VarDecl>(DUnderlying)) {
434 // If the existing declaration is hidden, prefer the new one. Otherwise,
435 // keep what we've got.
436 return !S.isVisible(Existing);
439 // Pick the newer declaration; it might have a more precise type.
440 for (Decl *Prev = DUnderlying->getPreviousDecl(); Prev;
441 Prev = Prev->getPreviousDecl())
442 if (Prev == EUnderlying)
447 /// Determine whether \p D can hide a tag declaration.
448 static bool canHideTag(NamedDecl *D) {
449 // C++ [basic.scope.declarative]p4:
450 // Given a set of declarations in a single declarative region [...]
451 // exactly one declaration shall declare a class name or enumeration name
452 // that is not a typedef name and the other declarations shall all refer to
453 // the same variable, non-static data member, or enumerator, or all refer
454 // to functions and function templates; in this case the class name or
455 // enumeration name is hidden.
456 // C++ [basic.scope.hiding]p2:
457 // A class name or enumeration name can be hidden by the name of a
458 // variable, data member, function, or enumerator declared in the same
460 // An UnresolvedUsingValueDecl always instantiates to one of these.
461 D = D->getUnderlyingDecl();
462 return isa<VarDecl>(D) || isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D) ||
463 isa<FunctionTemplateDecl>(D) || isa<FieldDecl>(D) ||
464 isa<UnresolvedUsingValueDecl>(D);
467 /// Resolves the result kind of this lookup.
468 void LookupResult::resolveKind() {
469 unsigned N = Decls.size();
471 // Fast case: no possible ambiguity.
473 assert(ResultKind == NotFound ||
474 ResultKind == NotFoundInCurrentInstantiation);
478 // If there's a single decl, we need to examine it to decide what
479 // kind of lookup this is.
481 NamedDecl *D = (*Decls.begin())->getUnderlyingDecl();
482 if (isa<FunctionTemplateDecl>(D))
483 ResultKind = FoundOverloaded;
484 else if (isa<UnresolvedUsingValueDecl>(D))
485 ResultKind = FoundUnresolvedValue;
489 // Don't do any extra resolution if we've already resolved as ambiguous.
490 if (ResultKind == Ambiguous) return;
492 llvm::SmallDenseMap<NamedDecl*, unsigned, 16> Unique;
493 llvm::SmallDenseMap<QualType, unsigned, 16> UniqueTypes;
495 bool Ambiguous = false;
496 bool HasTag = false, HasFunction = false;
497 bool HasFunctionTemplate = false, HasUnresolved = false;
498 NamedDecl *HasNonFunction = nullptr;
500 llvm::SmallVector<NamedDecl*, 4> EquivalentNonFunctions;
502 unsigned UniqueTagIndex = 0;
506 NamedDecl *D = Decls[I]->getUnderlyingDecl();
507 D = cast<NamedDecl>(D->getCanonicalDecl());
509 // Ignore an invalid declaration unless it's the only one left.
510 if (D->isInvalidDecl() && !(I == 0 && N == 1)) {
511 Decls[I] = Decls[--N];
515 llvm::Optional<unsigned> ExistingI;
517 // Redeclarations of types via typedef can occur both within a scope
518 // and, through using declarations and directives, across scopes. There is
519 // no ambiguity if they all refer to the same type, so unique based on the
521 if (TypeDecl *TD = dyn_cast<TypeDecl>(D)) {
522 QualType T = getSema().Context.getTypeDeclType(TD);
523 auto UniqueResult = UniqueTypes.insert(
524 std::make_pair(getSema().Context.getCanonicalType(T), I));
525 if (!UniqueResult.second) {
526 // The type is not unique.
527 ExistingI = UniqueResult.first->second;
531 // For non-type declarations, check for a prior lookup result naming this
532 // canonical declaration.
534 auto UniqueResult = Unique.insert(std::make_pair(D, I));
535 if (!UniqueResult.second) {
536 // We've seen this entity before.
537 ExistingI = UniqueResult.first->second;
542 // This is not a unique lookup result. Pick one of the results and
543 // discard the other.
544 if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I],
546 Decls[*ExistingI] = Decls[I];
547 Decls[I] = Decls[--N];
551 // Otherwise, do some decl type analysis and then continue.
553 if (isa<UnresolvedUsingValueDecl>(D)) {
554 HasUnresolved = true;
555 } else if (isa<TagDecl>(D)) {
560 } else if (isa<FunctionTemplateDecl>(D)) {
562 HasFunctionTemplate = true;
563 } else if (isa<FunctionDecl>(D)) {
566 if (HasNonFunction) {
567 // If we're about to create an ambiguity between two declarations that
568 // are equivalent, but one is an internal linkage declaration from one
569 // module and the other is an internal linkage declaration from another
570 // module, just skip it.
571 if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction,
573 EquivalentNonFunctions.push_back(D);
574 Decls[I] = Decls[--N];
585 // C++ [basic.scope.hiding]p2:
586 // A class name or enumeration name can be hidden by the name of
587 // an object, function, or enumerator declared in the same
588 // scope. If a class or enumeration name and an object, function,
589 // or enumerator are declared in the same scope (in any order)
590 // with the same name, the class or enumeration name is hidden
591 // wherever the object, function, or enumerator name is visible.
592 // But it's still an error if there are distinct tag types found,
593 // even if they're not visible. (ref?)
594 if (N > 1 && HideTags && HasTag && !Ambiguous &&
595 (HasFunction || HasNonFunction || HasUnresolved)) {
596 NamedDecl *OtherDecl = Decls[UniqueTagIndex ? 0 : N - 1];
597 if (isa<TagDecl>(Decls[UniqueTagIndex]->getUnderlyingDecl()) &&
598 getContextForScopeMatching(Decls[UniqueTagIndex])->Equals(
599 getContextForScopeMatching(OtherDecl)) &&
600 canHideTag(OtherDecl))
601 Decls[UniqueTagIndex] = Decls[--N];
606 // FIXME: This diagnostic should really be delayed until we're done with
607 // the lookup result, in case the ambiguity is resolved by the caller.
608 if (!EquivalentNonFunctions.empty() && !Ambiguous)
609 getSema().diagnoseEquivalentInternalLinkageDeclarations(
610 getNameLoc(), HasNonFunction, EquivalentNonFunctions);
614 if (HasNonFunction && (HasFunction || HasUnresolved))
618 setAmbiguous(LookupResult::AmbiguousReference);
619 else if (HasUnresolved)
620 ResultKind = LookupResult::FoundUnresolvedValue;
621 else if (N > 1 || HasFunctionTemplate)
622 ResultKind = LookupResult::FoundOverloaded;
624 ResultKind = LookupResult::Found;
627 void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) {
628 CXXBasePaths::const_paths_iterator I, E;
629 for (I = P.begin(), E = P.end(); I != E; ++I)
630 for (DeclContext::lookup_iterator DI = I->Decls.begin(),
631 DE = I->Decls.end(); DI != DE; ++DI)
635 void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) {
636 Paths = new CXXBasePaths;
638 addDeclsFromBasePaths(*Paths);
640 setAmbiguous(AmbiguousBaseSubobjects);
643 void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) {
644 Paths = new CXXBasePaths;
646 addDeclsFromBasePaths(*Paths);
648 setAmbiguous(AmbiguousBaseSubobjectTypes);
651 void LookupResult::print(raw_ostream &Out) {
652 Out << Decls.size() << " result(s)";
653 if (isAmbiguous()) Out << ", ambiguous";
654 if (Paths) Out << ", base paths present";
656 for (iterator I = begin(), E = end(); I != E; ++I) {
662 LLVM_DUMP_METHOD void LookupResult::dump() {
663 llvm::errs() << "lookup results for " << getLookupName().getAsString()
665 for (NamedDecl *D : *this)
669 /// \brief Lookup a builtin function, when name lookup would otherwise
671 static bool LookupBuiltin(Sema &S, LookupResult &R) {
672 Sema::LookupNameKind NameKind = R.getLookupKind();
674 // If we didn't find a use of this identifier, and if the identifier
675 // corresponds to a compiler builtin, create the decl object for the builtin
676 // now, injecting it into translation unit scope, and return it.
677 if (NameKind == Sema::LookupOrdinaryName ||
678 NameKind == Sema::LookupRedeclarationWithLinkage) {
679 IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo();
681 if (S.getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName) {
682 if (II == S.getASTContext().getMakeIntegerSeqName()) {
683 R.addDecl(S.getASTContext().getMakeIntegerSeqDecl());
685 } else if (II == S.getASTContext().getTypePackElementName()) {
686 R.addDecl(S.getASTContext().getTypePackElementDecl());
691 // If this is a builtin on this (or all) targets, create the decl.
692 if (unsigned BuiltinID = II->getBuiltinID()) {
693 // In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined
694 // library functions like 'malloc'. Instead, we'll just error.
695 if ((S.getLangOpts().CPlusPlus || S.getLangOpts().OpenCL) &&
696 S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
699 if (NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II,
700 BuiltinID, S.TUScope,
701 R.isForRedeclaration(),
713 /// \brief Determine whether we can declare a special member function within
714 /// the class at this point.
715 static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) {
716 // We need to have a definition for the class.
717 if (!Class->getDefinition() || Class->isDependentContext())
720 // We can't be in the middle of defining the class.
721 return !Class->isBeingDefined();
724 void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) {
725 if (!CanDeclareSpecialMemberFunction(Class))
728 // If the default constructor has not yet been declared, do so now.
729 if (Class->needsImplicitDefaultConstructor())
730 DeclareImplicitDefaultConstructor(Class);
732 // If the copy constructor has not yet been declared, do so now.
733 if (Class->needsImplicitCopyConstructor())
734 DeclareImplicitCopyConstructor(Class);
736 // If the copy assignment operator has not yet been declared, do so now.
737 if (Class->needsImplicitCopyAssignment())
738 DeclareImplicitCopyAssignment(Class);
740 if (getLangOpts().CPlusPlus11) {
741 // If the move constructor has not yet been declared, do so now.
742 if (Class->needsImplicitMoveConstructor())
743 DeclareImplicitMoveConstructor(Class);
745 // If the move assignment operator has not yet been declared, do so now.
746 if (Class->needsImplicitMoveAssignment())
747 DeclareImplicitMoveAssignment(Class);
750 // If the destructor has not yet been declared, do so now.
751 if (Class->needsImplicitDestructor())
752 DeclareImplicitDestructor(Class);
755 /// \brief Determine whether this is the name of an implicitly-declared
756 /// special member function.
757 static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) {
758 switch (Name.getNameKind()) {
759 case DeclarationName::CXXConstructorName:
760 case DeclarationName::CXXDestructorName:
763 case DeclarationName::CXXOperatorName:
764 return Name.getCXXOverloadedOperator() == OO_Equal;
773 /// \brief If there are any implicit member functions with the given name
774 /// that need to be declared in the given declaration context, do so.
775 static void DeclareImplicitMemberFunctionsWithName(Sema &S,
776 DeclarationName Name,
778 const DeclContext *DC) {
782 switch (Name.getNameKind()) {
783 case DeclarationName::CXXConstructorName:
784 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
785 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
786 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
787 if (Record->needsImplicitDefaultConstructor())
788 S.DeclareImplicitDefaultConstructor(Class);
789 if (Record->needsImplicitCopyConstructor())
790 S.DeclareImplicitCopyConstructor(Class);
791 if (S.getLangOpts().CPlusPlus11 &&
792 Record->needsImplicitMoveConstructor())
793 S.DeclareImplicitMoveConstructor(Class);
797 case DeclarationName::CXXDestructorName:
798 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC))
799 if (Record->getDefinition() && Record->needsImplicitDestructor() &&
800 CanDeclareSpecialMemberFunction(Record))
801 S.DeclareImplicitDestructor(const_cast<CXXRecordDecl *>(Record));
804 case DeclarationName::CXXOperatorName:
805 if (Name.getCXXOverloadedOperator() != OO_Equal)
808 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC)) {
809 if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) {
810 CXXRecordDecl *Class = const_cast<CXXRecordDecl *>(Record);
811 if (Record->needsImplicitCopyAssignment())
812 S.DeclareImplicitCopyAssignment(Class);
813 if (S.getLangOpts().CPlusPlus11 &&
814 Record->needsImplicitMoveAssignment())
815 S.DeclareImplicitMoveAssignment(Class);
820 case DeclarationName::CXXDeductionGuideName:
821 S.DeclareImplicitDeductionGuides(Name.getCXXDeductionGuideTemplate(), Loc);
829 // Adds all qualifying matches for a name within a decl context to the
830 // given lookup result. Returns true if any matches were found.
831 static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) {
834 // Lazily declare C++ special member functions.
835 if (S.getLangOpts().CPlusPlus)
836 DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), R.getNameLoc(),
839 // Perform lookup into this declaration context.
840 DeclContext::lookup_result DR = DC->lookup(R.getLookupName());
841 for (NamedDecl *D : DR) {
842 if ((D = R.getAcceptableDecl(D))) {
848 if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R))
851 if (R.getLookupName().getNameKind()
852 != DeclarationName::CXXConversionFunctionName ||
853 R.getLookupName().getCXXNameType()->isDependentType() ||
854 !isa<CXXRecordDecl>(DC))
858 // A specialization of a conversion function template is not found by
859 // name lookup. Instead, any conversion function templates visible in the
860 // context of the use are considered. [...]
861 const CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
862 if (!Record->isCompleteDefinition())
865 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(),
866 UEnd = Record->conversion_end(); U != UEnd; ++U) {
867 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
871 // When we're performing lookup for the purposes of redeclaration, just
872 // add the conversion function template. When we deduce template
873 // arguments for specializations, we'll end up unifying the return
874 // type of the new declaration with the type of the function template.
875 if (R.isForRedeclaration()) {
876 R.addDecl(ConvTemplate);
882 // [...] For each such operator, if argument deduction succeeds
883 // (14.9.2.3), the resulting specialization is used as if found by
886 // When referencing a conversion function for any purpose other than
887 // a redeclaration (such that we'll be building an expression with the
888 // result), perform template argument deduction and place the
889 // specialization into the result set. We do this to avoid forcing all
890 // callers to perform special deduction for conversion functions.
891 TemplateDeductionInfo Info(R.getNameLoc());
892 FunctionDecl *Specialization = nullptr;
894 const FunctionProtoType *ConvProto
895 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
896 assert(ConvProto && "Nonsensical conversion function template type");
898 // Compute the type of the function that we would expect the conversion
899 // function to have, if it were to match the name given.
900 // FIXME: Calling convention!
901 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo();
902 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C);
903 EPI.ExceptionSpec = EST_None;
904 QualType ExpectedType
905 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(),
908 // Perform template argument deduction against the type that we would
909 // expect the function to have.
910 if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType,
911 Specialization, Info)
912 == Sema::TDK_Success) {
913 R.addDecl(Specialization);
921 // Performs C++ unqualified lookup into the given file context.
923 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context,
924 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
926 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
928 // Perform direct name lookup into the LookupCtx.
929 bool Found = LookupDirect(S, R, NS);
931 // Perform direct name lookup into the namespaces nominated by the
932 // using directives whose common ancestor is this namespace.
933 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS))
934 if (LookupDirect(S, R, UUE.getNominatedNamespace()))
942 static bool isNamespaceOrTranslationUnitScope(Scope *S) {
943 if (DeclContext *Ctx = S->getEntity())
944 return Ctx->isFileContext();
948 // Find the next outer declaration context from this scope. This
949 // routine actually returns the semantic outer context, which may
950 // differ from the lexical context (encoded directly in the Scope
951 // stack) when we are parsing a member of a class template. In this
952 // case, the second element of the pair will be true, to indicate that
953 // name lookup should continue searching in this semantic context when
954 // it leaves the current template parameter scope.
955 static std::pair<DeclContext *, bool> findOuterContext(Scope *S) {
956 DeclContext *DC = S->getEntity();
957 DeclContext *Lexical = nullptr;
958 for (Scope *OuterS = S->getParent(); OuterS;
959 OuterS = OuterS->getParent()) {
960 if (OuterS->getEntity()) {
961 Lexical = OuterS->getEntity();
966 // C++ [temp.local]p8:
967 // In the definition of a member of a class template that appears
968 // outside of the namespace containing the class template
969 // definition, the name of a template-parameter hides the name of
970 // a member of this namespace.
977 // template<class T> class B {
982 // template<class C> void N::B<C>::f(C) {
983 // C b; // C is the template parameter, not N::C
986 // In this example, the lexical context we return is the
987 // TranslationUnit, while the semantic context is the namespace N.
988 if (!Lexical || !DC || !S->getParent() ||
989 !S->getParent()->isTemplateParamScope())
990 return std::make_pair(Lexical, false);
992 // Find the outermost template parameter scope.
993 // For the example, this is the scope for the template parameters of
994 // template<class C>.
995 Scope *OutermostTemplateScope = S->getParent();
996 while (OutermostTemplateScope->getParent() &&
997 OutermostTemplateScope->getParent()->isTemplateParamScope())
998 OutermostTemplateScope = OutermostTemplateScope->getParent();
1000 // Find the namespace context in which the original scope occurs. In
1001 // the example, this is namespace N.
1002 DeclContext *Semantic = DC;
1003 while (!Semantic->isFileContext())
1004 Semantic = Semantic->getParent();
1006 // Find the declaration context just outside of the template
1007 // parameter scope. This is the context in which the template is
1008 // being lexically declaration (a namespace context). In the
1009 // example, this is the global scope.
1010 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) &&
1011 Lexical->Encloses(Semantic))
1012 return std::make_pair(Semantic, true);
1014 return std::make_pair(Lexical, false);
1018 /// An RAII object to specify that we want to find block scope extern
1020 struct FindLocalExternScope {
1021 FindLocalExternScope(LookupResult &R)
1022 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
1023 Decl::IDNS_LocalExtern) {
1024 R.setFindLocalExtern(R.getIdentifierNamespace() & Decl::IDNS_Ordinary);
1027 R.setFindLocalExtern(OldFindLocalExtern);
1029 ~FindLocalExternScope() {
1033 bool OldFindLocalExtern;
1035 } // end anonymous namespace
1037 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
1038 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
1040 DeclarationName Name = R.getLookupName();
1041 Sema::LookupNameKind NameKind = R.getLookupKind();
1043 // If this is the name of an implicitly-declared special member function,
1044 // go through the scope stack to implicitly declare
1045 if (isImplicitlyDeclaredMemberFunctionName(Name)) {
1046 for (Scope *PreS = S; PreS; PreS = PreS->getParent())
1047 if (DeclContext *DC = PreS->getEntity())
1048 DeclareImplicitMemberFunctionsWithName(*this, Name, R.getNameLoc(), DC);
1051 // Implicitly declare member functions with the name we're looking for, if in
1052 // fact we are in a scope where it matters.
1055 IdentifierResolver::iterator
1056 I = IdResolver.begin(Name),
1057 IEnd = IdResolver.end();
1059 // First we lookup local scope.
1060 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
1061 // ...During unqualified name lookup (3.4.1), the names appear as if
1062 // they were declared in the nearest enclosing namespace which contains
1063 // both the using-directive and the nominated namespace.
1064 // [Note: in this context, "contains" means "contains directly or
1068 // namespace A { int i; }
1072 // using namespace A;
1073 // ++i; // finds local 'i', A::i appears at global scope
1077 UnqualUsingDirectiveSet UDirs;
1078 bool VisitedUsingDirectives = false;
1079 bool LeftStartingScope = false;
1080 DeclContext *OutsideOfTemplateParamDC = nullptr;
1082 // When performing a scope lookup, we want to find local extern decls.
1083 FindLocalExternScope FindLocals(R);
1085 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
1086 DeclContext *Ctx = S->getEntity();
1087 bool SearchNamespaceScope = true;
1088 // Check whether the IdResolver has anything in this scope.
1089 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1090 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1091 if (NameKind == LookupRedeclarationWithLinkage &&
1092 !(*I)->isTemplateParameter()) {
1093 // If it's a template parameter, we still find it, so we can diagnose
1094 // the invalid redeclaration.
1096 // Determine whether this (or a previous) declaration is
1098 if (!LeftStartingScope && !Initial->isDeclScope(*I))
1099 LeftStartingScope = true;
1101 // If we found something outside of our starting scope that
1102 // does not have linkage, skip it.
1103 if (LeftStartingScope && !((*I)->hasLinkage())) {
1108 // We found something in this scope, we should not look at the
1110 SearchNamespaceScope = false;
1115 if (!SearchNamespaceScope) {
1117 if (S->isClassScope())
1118 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx))
1119 R.setNamingClass(Record);
1123 if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
1124 // C++11 [class.friend]p11:
1125 // If a friend declaration appears in a local class and the name
1126 // specified is an unqualified name, a prior declaration is
1127 // looked up without considering scopes that are outside the
1128 // innermost enclosing non-class scope.
1132 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1133 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1134 // We've just searched the last template parameter scope and
1135 // found nothing, so look into the contexts between the
1136 // lexical and semantic declaration contexts returned by
1137 // findOuterContext(). This implements the name lookup behavior
1138 // of C++ [temp.local]p8.
1139 Ctx = OutsideOfTemplateParamDC;
1140 OutsideOfTemplateParamDC = nullptr;
1144 DeclContext *OuterCtx;
1145 bool SearchAfterTemplateScope;
1146 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1147 if (SearchAfterTemplateScope)
1148 OutsideOfTemplateParamDC = OuterCtx;
1150 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1151 // We do not directly look into transparent contexts, since
1152 // those entities will be found in the nearest enclosing
1153 // non-transparent context.
1154 if (Ctx->isTransparentContext())
1157 // We do not look directly into function or method contexts,
1158 // since all of the local variables and parameters of the
1159 // function/method are present within the Scope.
1160 if (Ctx->isFunctionOrMethod()) {
1161 // If we have an Objective-C instance method, look for ivars
1162 // in the corresponding interface.
1163 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
1164 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
1165 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
1166 ObjCInterfaceDecl *ClassDeclared;
1167 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
1168 Name.getAsIdentifierInfo(),
1170 if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
1182 // If this is a file context, we need to perform unqualified name
1183 // lookup considering using directives.
1184 if (Ctx->isFileContext()) {
1185 // If we haven't handled using directives yet, do so now.
1186 if (!VisitedUsingDirectives) {
1187 // Add using directives from this context up to the top level.
1188 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
1189 if (UCtx->isTransparentContext())
1192 UDirs.visit(UCtx, UCtx);
1195 // Find the innermost file scope, so we can add using directives
1196 // from local scopes.
1197 Scope *InnermostFileScope = S;
1198 while (InnermostFileScope &&
1199 !isNamespaceOrTranslationUnitScope(InnermostFileScope))
1200 InnermostFileScope = InnermostFileScope->getParent();
1201 UDirs.visitScopeChain(Initial, InnermostFileScope);
1205 VisitedUsingDirectives = true;
1208 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
1216 // Perform qualified name lookup into this context.
1217 // FIXME: In some cases, we know that every name that could be found by
1218 // this qualified name lookup will also be on the identifier chain. For
1219 // example, inside a class without any base classes, we never need to
1220 // perform qualified lookup because all of the members are on top of the
1221 // identifier chain.
1222 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
1228 // Stop if we ran out of scopes.
1229 // FIXME: This really, really shouldn't be happening.
1230 if (!S) return false;
1232 // If we are looking for members, no need to look into global/namespace scope.
1233 if (NameKind == LookupMemberName)
1236 // Collect UsingDirectiveDecls in all scopes, and recursively all
1237 // nominated namespaces by those using-directives.
1239 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
1240 // don't build it for each lookup!
1241 if (!VisitedUsingDirectives) {
1242 UDirs.visitScopeChain(Initial, S);
1246 // If we're not performing redeclaration lookup, do not look for local
1247 // extern declarations outside of a function scope.
1248 if (!R.isForRedeclaration())
1249 FindLocals.restore();
1251 // Lookup namespace scope, and global scope.
1252 // Unqualified name lookup in C++ requires looking into scopes
1253 // that aren't strictly lexical, and therefore we walk through the
1254 // context as well as walking through the scopes.
1255 for (; S; S = S->getParent()) {
1256 // Check whether the IdResolver has anything in this scope.
1258 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1259 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1260 // We found something. Look for anything else in our scope
1261 // with this same name and in an acceptable identifier
1262 // namespace, so that we can construct an overload set if we
1269 if (Found && S->isTemplateParamScope()) {
1274 DeclContext *Ctx = S->getEntity();
1275 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1276 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1277 // We've just searched the last template parameter scope and
1278 // found nothing, so look into the contexts between the
1279 // lexical and semantic declaration contexts returned by
1280 // findOuterContext(). This implements the name lookup behavior
1281 // of C++ [temp.local]p8.
1282 Ctx = OutsideOfTemplateParamDC;
1283 OutsideOfTemplateParamDC = nullptr;
1287 DeclContext *OuterCtx;
1288 bool SearchAfterTemplateScope;
1289 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1290 if (SearchAfterTemplateScope)
1291 OutsideOfTemplateParamDC = OuterCtx;
1293 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1294 // We do not directly look into transparent contexts, since
1295 // those entities will be found in the nearest enclosing
1296 // non-transparent context.
1297 if (Ctx->isTransparentContext())
1300 // If we have a context, and it's not a context stashed in the
1301 // template parameter scope for an out-of-line definition, also
1302 // look into that context.
1303 if (!(Found && S->isTemplateParamScope())) {
1304 assert(Ctx->isFileContext() &&
1305 "We should have been looking only at file context here already.");
1307 // Look into context considering using-directives.
1308 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
1317 if (R.isForRedeclaration() && !Ctx->isTransparentContext())
1322 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
1329 Module *Sema::getOwningModule(Decl *Entity) {
1330 // If it's imported, grab its owning module.
1331 Module *M = Entity->getImportedOwningModule();
1332 if (M || !isa<NamedDecl>(Entity) || !cast<NamedDecl>(Entity)->isHidden())
1334 assert(!Entity->isFromASTFile() &&
1335 "hidden entity from AST file has no owning module");
1337 if (!getLangOpts().ModulesLocalVisibility) {
1338 // If we're not tracking visibility locally, the only way a declaration
1339 // can be hidden and local is if it's hidden because it's parent is (for
1340 // instance, maybe this is a lazily-declared special member of an imported
1342 auto *Parent = cast<NamedDecl>(Entity->getDeclContext());
1343 assert(Parent->isHidden() && "unexpectedly hidden decl");
1344 return getOwningModule(Parent);
1347 // It's local and hidden; grab or compute its owning module.
1348 M = Entity->getLocalOwningModule();
1352 if (auto *Containing =
1353 PP.getModuleContainingLocation(Entity->getLocation())) {
1355 } else if (Entity->isInvalidDecl() || Entity->getLocation().isInvalid()) {
1356 // Don't bother tracking visibility for invalid declarations with broken
1358 cast<NamedDecl>(Entity)->setHidden(false);
1360 // We need to assign a module to an entity that exists outside of any
1361 // module, so that we can hide it from modules that we textually enter.
1362 // Invent a fake module for all such entities.
1363 if (!CachedFakeTopLevelModule) {
1364 CachedFakeTopLevelModule =
1365 PP.getHeaderSearchInfo().getModuleMap().findOrCreateModule(
1366 "<top-level>", nullptr, false, false).first;
1368 auto &SrcMgr = PP.getSourceManager();
1369 SourceLocation StartLoc =
1370 SrcMgr.getLocForStartOfFile(SrcMgr.getMainFileID());
1371 auto &TopLevel = ModuleScopes.empty()
1373 : ModuleScopes[0].OuterVisibleModules;
1374 TopLevel.setVisible(CachedFakeTopLevelModule, StartLoc);
1377 M = CachedFakeTopLevelModule;
1381 Entity->setLocalOwningModule(M);
1385 void Sema::makeMergedDefinitionVisible(NamedDecl *ND, SourceLocation Loc) {
1386 if (auto *M = PP.getModuleContainingLocation(Loc))
1387 Context.mergeDefinitionIntoModule(ND, M);
1389 // We're not building a module; just make the definition visible.
1390 ND->setHidden(false);
1392 // If ND is a template declaration, make the template parameters
1393 // visible too. They're not (necessarily) within a mergeable DeclContext.
1394 if (auto *TD = dyn_cast<TemplateDecl>(ND))
1395 for (auto *Param : *TD->getTemplateParameters())
1396 makeMergedDefinitionVisible(Param, Loc);
1399 /// \brief Find the module in which the given declaration was defined.
1400 static Module *getDefiningModule(Sema &S, Decl *Entity) {
1401 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
1402 // If this function was instantiated from a template, the defining module is
1403 // the module containing the pattern.
1404 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1406 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
1407 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1409 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
1410 if (auto *Pattern = ED->getTemplateInstantiationPattern())
1412 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
1413 if (VarDecl *Pattern = VD->getTemplateInstantiationPattern())
1417 // Walk up to the containing context. That might also have been instantiated
1419 DeclContext *Context = Entity->getDeclContext();
1420 if (Context->isFileContext())
1421 return S.getOwningModule(Entity);
1422 return getDefiningModule(S, cast<Decl>(Context));
1425 llvm::DenseSet<Module*> &Sema::getLookupModules() {
1426 unsigned N = CodeSynthesisContexts.size();
1427 for (unsigned I = CodeSynthesisContextLookupModules.size();
1429 Module *M = getDefiningModule(*this, CodeSynthesisContexts[I].Entity);
1430 if (M && !LookupModulesCache.insert(M).second)
1432 CodeSynthesisContextLookupModules.push_back(M);
1434 return LookupModulesCache;
1437 bool Sema::hasVisibleMergedDefinition(NamedDecl *Def) {
1438 for (Module *Merged : Context.getModulesWithMergedDefinition(Def))
1439 if (isModuleVisible(Merged))
1444 template<typename ParmDecl>
1446 hasVisibleDefaultArgument(Sema &S, const ParmDecl *D,
1447 llvm::SmallVectorImpl<Module *> *Modules) {
1448 if (!D->hasDefaultArgument())
1452 auto &DefaultArg = D->getDefaultArgStorage();
1453 if (!DefaultArg.isInherited() && S.isVisible(D))
1456 if (!DefaultArg.isInherited() && Modules) {
1457 auto *NonConstD = const_cast<ParmDecl*>(D);
1458 Modules->push_back(S.getOwningModule(NonConstD));
1459 const auto &Merged = S.Context.getModulesWithMergedDefinition(NonConstD);
1460 Modules->insert(Modules->end(), Merged.begin(), Merged.end());
1463 // If there was a previous default argument, maybe its parameter is visible.
1464 D = DefaultArg.getInheritedFrom();
1469 bool Sema::hasVisibleDefaultArgument(const NamedDecl *D,
1470 llvm::SmallVectorImpl<Module *> *Modules) {
1471 if (auto *P = dyn_cast<TemplateTypeParmDecl>(D))
1472 return ::hasVisibleDefaultArgument(*this, P, Modules);
1473 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D))
1474 return ::hasVisibleDefaultArgument(*this, P, Modules);
1475 return ::hasVisibleDefaultArgument(*this, cast<TemplateTemplateParmDecl>(D),
1479 bool Sema::hasVisibleMemberSpecialization(
1480 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1481 assert(isa<CXXRecordDecl>(D->getDeclContext()) &&
1482 "not a member specialization");
1483 for (auto *Redecl : D->redecls()) {
1484 // If the specialization is declared at namespace scope, then it's a member
1485 // specialization declaration. If it's lexically inside the class
1486 // definition then it was instantiated.
1488 // FIXME: This is a hack. There should be a better way to determine this.
1489 // FIXME: What about MS-style explicit specializations declared within a
1490 // class definition?
1491 if (Redecl->getLexicalDeclContext()->isFileContext()) {
1492 auto *NonConstR = const_cast<NamedDecl*>(cast<NamedDecl>(Redecl));
1494 if (isVisible(NonConstR))
1498 Modules->push_back(getOwningModule(NonConstR));
1499 const auto &Merged = Context.getModulesWithMergedDefinition(NonConstR);
1500 Modules->insert(Modules->end(), Merged.begin(), Merged.end());
1508 /// \brief Determine whether a declaration is visible to name lookup.
1510 /// This routine determines whether the declaration D is visible in the current
1511 /// lookup context, taking into account the current template instantiation
1512 /// stack. During template instantiation, a declaration is visible if it is
1513 /// visible from a module containing any entity on the template instantiation
1514 /// path (by instantiating a template, you allow it to see the declarations that
1515 /// your module can see, including those later on in your module).
1516 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
1517 assert(D->isHidden() && "should not call this: not in slow case");
1518 Module *DeclModule = nullptr;
1520 if (SemaRef.getLangOpts().ModulesLocalVisibility) {
1521 DeclModule = SemaRef.getOwningModule(D);
1523 // getOwningModule() may have decided the declaration should not be hidden.
1524 assert(!D->isHidden() && "hidden decl not from a module");
1528 // If the owning module is visible, and the decl is not module private,
1529 // then the decl is visible too. (Module private is ignored within the same
1530 // top-level module.)
1531 if ((!D->isFromASTFile() || !D->isModulePrivate()) &&
1532 (SemaRef.isModuleVisible(DeclModule) ||
1533 SemaRef.hasVisibleMergedDefinition(D)))
1537 // If this declaration is not at namespace scope nor module-private,
1538 // then it is visible if its lexical parent has a visible definition.
1539 DeclContext *DC = D->getLexicalDeclContext();
1540 if (!D->isModulePrivate() && DC && !DC->isFileContext() &&
1541 !isa<LinkageSpecDecl>(DC) && !isa<ExportDecl>(DC)) {
1542 // For a parameter, check whether our current template declaration's
1543 // lexical context is visible, not whether there's some other visible
1544 // definition of it, because parameters aren't "within" the definition.
1546 // In C++ we need to check for a visible definition due to ODR merging,
1547 // and in C we must not because each declaration of a function gets its own
1548 // set of declarations for tags in prototype scope.
1549 if ((D->isTemplateParameter() || isa<ParmVarDecl>(D)
1550 || (isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus))
1551 ? isVisible(SemaRef, cast<NamedDecl>(DC))
1552 : SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC))) {
1553 if (SemaRef.CodeSynthesisContexts.empty() &&
1554 // FIXME: Do something better in this case.
1555 !SemaRef.getLangOpts().ModulesLocalVisibility) {
1556 // Cache the fact that this declaration is implicitly visible because
1557 // its parent has a visible definition.
1558 D->setHidden(false);
1565 // Find the extra places where we need to look.
1566 llvm::DenseSet<Module*> &LookupModules = SemaRef.getLookupModules();
1567 if (LookupModules.empty())
1571 DeclModule = SemaRef.getOwningModule(D);
1572 assert(DeclModule && "hidden decl not from a module");
1575 // If our lookup set contains the decl's module, it's visible.
1576 if (LookupModules.count(DeclModule))
1579 // If the declaration isn't exported, it's not visible in any other module.
1580 if (D->isModulePrivate())
1583 // Check whether DeclModule is transitively exported to an import of
1585 return std::any_of(LookupModules.begin(), LookupModules.end(),
1586 [&](Module *M) { return M->isModuleVisible(DeclModule); });
1589 bool Sema::isVisibleSlow(const NamedDecl *D) {
1590 return LookupResult::isVisible(*this, const_cast<NamedDecl*>(D));
1593 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
1598 return New->isExternallyVisible();
1601 /// \brief Retrieve the visible declaration corresponding to D, if any.
1603 /// This routine determines whether the declaration D is visible in the current
1604 /// module, with the current imports. If not, it checks whether any
1605 /// redeclaration of D is visible, and if so, returns that declaration.
1607 /// \returns D, or a visible previous declaration of D, whichever is more recent
1608 /// and visible. If no declaration of D is visible, returns null.
1609 static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D) {
1610 assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case");
1612 for (auto RD : D->redecls()) {
1613 // Don't bother with extra checks if we already know this one isn't visible.
1617 auto ND = cast<NamedDecl>(RD);
1618 // FIXME: This is wrong in the case where the previous declaration is not
1619 // visible in the same scope as D. This needs to be done much more
1621 if (LookupResult::isVisible(SemaRef, ND))
1628 bool Sema::hasVisibleDeclarationSlow(const NamedDecl *D,
1629 llvm::SmallVectorImpl<Module *> *Modules) {
1630 assert(!isVisible(D) && "not in slow case");
1632 for (auto *Redecl : D->redecls()) {
1633 auto *NonConstR = const_cast<NamedDecl*>(cast<NamedDecl>(Redecl));
1634 if (isVisible(NonConstR))
1638 Modules->push_back(getOwningModule(NonConstR));
1639 const auto &Merged = Context.getModulesWithMergedDefinition(NonConstR);
1640 Modules->insert(Modules->end(), Merged.begin(), Merged.end());
1647 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
1648 if (auto *ND = dyn_cast<NamespaceDecl>(D)) {
1649 // Namespaces are a bit of a special case: we expect there to be a lot of
1650 // redeclarations of some namespaces, all declarations of a namespace are
1651 // essentially interchangeable, all declarations are found by name lookup
1652 // if any is, and namespaces are never looked up during template
1653 // instantiation. So we benefit from caching the check in this case, and
1654 // it is correct to do so.
1655 auto *Key = ND->getCanonicalDecl();
1656 if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key))
1659 isVisible(getSema(), Key) ? Key : findAcceptableDecl(getSema(), Key);
1661 getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable));
1665 return findAcceptableDecl(getSema(), D);
1668 /// @brief Perform unqualified name lookup starting from a given
1671 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
1672 /// used to find names within the current scope. For example, 'x' in
1676 /// return x; // unqualified name look finds 'x' in the global scope
1680 /// Different lookup criteria can find different names. For example, a
1681 /// particular scope can have both a struct and a function of the same
1682 /// name, and each can be found by certain lookup criteria. For more
1683 /// information about lookup criteria, see the documentation for the
1684 /// class LookupCriteria.
1686 /// @param S The scope from which unqualified name lookup will
1687 /// begin. If the lookup criteria permits, name lookup may also search
1688 /// in the parent scopes.
1690 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to
1691 /// look up and the lookup kind), and is updated with the results of lookup
1692 /// including zero or more declarations and possibly additional information
1693 /// used to diagnose ambiguities.
1695 /// @returns \c true if lookup succeeded and false otherwise.
1696 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
1697 DeclarationName Name = R.getLookupName();
1698 if (!Name) return false;
1700 LookupNameKind NameKind = R.getLookupKind();
1702 if (!getLangOpts().CPlusPlus) {
1703 // Unqualified name lookup in C/Objective-C is purely lexical, so
1704 // search in the declarations attached to the name.
1705 if (NameKind == Sema::LookupRedeclarationWithLinkage) {
1706 // Find the nearest non-transparent declaration scope.
1707 while (!(S->getFlags() & Scope::DeclScope) ||
1708 (S->getEntity() && S->getEntity()->isTransparentContext()))
1712 // When performing a scope lookup, we want to find local extern decls.
1713 FindLocalExternScope FindLocals(R);
1715 // Scan up the scope chain looking for a decl that matches this
1716 // identifier that is in the appropriate namespace. This search
1717 // should not take long, as shadowing of names is uncommon, and
1718 // deep shadowing is extremely uncommon.
1719 bool LeftStartingScope = false;
1721 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
1722 IEnd = IdResolver.end();
1724 if (NamedDecl *D = R.getAcceptableDecl(*I)) {
1725 if (NameKind == LookupRedeclarationWithLinkage) {
1726 // Determine whether this (or a previous) declaration is
1728 if (!LeftStartingScope && !S->isDeclScope(*I))
1729 LeftStartingScope = true;
1731 // If we found something outside of our starting scope that
1732 // does not have linkage, skip it.
1733 if (LeftStartingScope && !((*I)->hasLinkage())) {
1738 else if (NameKind == LookupObjCImplicitSelfParam &&
1739 !isa<ImplicitParamDecl>(*I))
1744 // Check whether there are any other declarations with the same name
1745 // and in the same scope.
1747 // Find the scope in which this declaration was declared (if it
1748 // actually exists in a Scope).
1749 while (S && !S->isDeclScope(D))
1752 // If the scope containing the declaration is the translation unit,
1753 // then we'll need to perform our checks based on the matching
1754 // DeclContexts rather than matching scopes.
1755 if (S && isNamespaceOrTranslationUnitScope(S))
1758 // Compute the DeclContext, if we need it.
1759 DeclContext *DC = nullptr;
1761 DC = (*I)->getDeclContext()->getRedeclContext();
1763 IdentifierResolver::iterator LastI = I;
1764 for (++LastI; LastI != IEnd; ++LastI) {
1766 // Match based on scope.
1767 if (!S->isDeclScope(*LastI))
1770 // Match based on DeclContext.
1772 = (*LastI)->getDeclContext()->getRedeclContext();
1773 if (!LastDC->Equals(DC))
1777 // If the declaration is in the right namespace and visible, add it.
1778 if (NamedDecl *LastD = R.getAcceptableDecl(*LastI))
1788 // Perform C++ unqualified name lookup.
1789 if (CppLookupName(R, S))
1793 // If we didn't find a use of this identifier, and if the identifier
1794 // corresponds to a compiler builtin, create the decl object for the builtin
1795 // now, injecting it into translation unit scope, and return it.
1796 if (AllowBuiltinCreation && LookupBuiltin(*this, R))
1799 // If we didn't find a use of this identifier, the ExternalSource
1800 // may be able to handle the situation.
1801 // Note: some lookup failures are expected!
1802 // See e.g. R.isForRedeclaration().
1803 return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
1806 /// @brief Perform qualified name lookup in the namespaces nominated by
1807 /// using directives by the given context.
1809 /// C++98 [namespace.qual]p2:
1810 /// Given X::m (where X is a user-declared namespace), or given \::m
1811 /// (where X is the global namespace), let S be the set of all
1812 /// declarations of m in X and in the transitive closure of all
1813 /// namespaces nominated by using-directives in X and its used
1814 /// namespaces, except that using-directives are ignored in any
1815 /// namespace, including X, directly containing one or more
1816 /// declarations of m. No namespace is searched more than once in
1817 /// the lookup of a name. If S is the empty set, the program is
1818 /// ill-formed. Otherwise, if S has exactly one member, or if the
1819 /// context of the reference is a using-declaration
1820 /// (namespace.udecl), S is the required set of declarations of
1821 /// m. Otherwise if the use of m is not one that allows a unique
1822 /// declaration to be chosen from S, the program is ill-formed.
1824 /// C++98 [namespace.qual]p5:
1825 /// During the lookup of a qualified namespace member name, if the
1826 /// lookup finds more than one declaration of the member, and if one
1827 /// declaration introduces a class name or enumeration name and the
1828 /// other declarations either introduce the same object, the same
1829 /// enumerator or a set of functions, the non-type name hides the
1830 /// class or enumeration name if and only if the declarations are
1831 /// from the same namespace; otherwise (the declarations are from
1832 /// different namespaces), the program is ill-formed.
1833 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
1834 DeclContext *StartDC) {
1835 assert(StartDC->isFileContext() && "start context is not a file context");
1837 DeclContext::udir_range UsingDirectives = StartDC->using_directives();
1838 if (UsingDirectives.begin() == UsingDirectives.end()) return false;
1840 // We have at least added all these contexts to the queue.
1841 llvm::SmallPtrSet<DeclContext*, 8> Visited;
1842 Visited.insert(StartDC);
1844 // We have not yet looked into these namespaces, much less added
1845 // their "using-children" to the queue.
1846 SmallVector<NamespaceDecl*, 8> Queue;
1848 // We have already looked into the initial namespace; seed the queue
1849 // with its using-children.
1850 for (auto *I : UsingDirectives) {
1851 NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace();
1852 if (Visited.insert(ND).second)
1853 Queue.push_back(ND);
1856 // The easiest way to implement the restriction in [namespace.qual]p5
1857 // is to check whether any of the individual results found a tag
1858 // and, if so, to declare an ambiguity if the final result is not
1860 bool FoundTag = false;
1861 bool FoundNonTag = false;
1863 LookupResult LocalR(LookupResult::Temporary, R);
1866 while (!Queue.empty()) {
1867 NamespaceDecl *ND = Queue.pop_back_val();
1869 // We go through some convolutions here to avoid copying results
1870 // between LookupResults.
1871 bool UseLocal = !R.empty();
1872 LookupResult &DirectR = UseLocal ? LocalR : R;
1873 bool FoundDirect = LookupDirect(S, DirectR, ND);
1876 // First do any local hiding.
1877 DirectR.resolveKind();
1879 // If the local result is a tag, remember that.
1880 if (DirectR.isSingleTagDecl())
1885 // Append the local results to the total results if necessary.
1887 R.addAllDecls(LocalR);
1892 // If we find names in this namespace, ignore its using directives.
1898 for (auto I : ND->using_directives()) {
1899 NamespaceDecl *Nom = I->getNominatedNamespace();
1900 if (Visited.insert(Nom).second)
1901 Queue.push_back(Nom);
1906 if (FoundTag && FoundNonTag)
1907 R.setAmbiguousQualifiedTagHiding();
1915 /// \brief Callback that looks for any member of a class with the given name.
1916 static bool LookupAnyMember(const CXXBaseSpecifier *Specifier,
1917 CXXBasePath &Path, DeclarationName Name) {
1918 RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
1920 Path.Decls = BaseRecord->lookup(Name);
1921 return !Path.Decls.empty();
1924 /// \brief Determine whether the given set of member declarations contains only
1925 /// static members, nested types, and enumerators.
1926 template<typename InputIterator>
1927 static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) {
1928 Decl *D = (*First)->getUnderlyingDecl();
1929 if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D))
1932 if (isa<CXXMethodDecl>(D)) {
1933 // Determine whether all of the methods are static.
1934 bool AllMethodsAreStatic = true;
1935 for(; First != Last; ++First) {
1936 D = (*First)->getUnderlyingDecl();
1938 if (!isa<CXXMethodDecl>(D)) {
1939 assert(isa<TagDecl>(D) && "Non-function must be a tag decl");
1943 if (!cast<CXXMethodDecl>(D)->isStatic()) {
1944 AllMethodsAreStatic = false;
1949 if (AllMethodsAreStatic)
1956 /// \brief Perform qualified name lookup into a given context.
1958 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
1959 /// names when the context of those names is explicit specified, e.g.,
1960 /// "std::vector" or "x->member", or as part of unqualified name lookup.
1962 /// Different lookup criteria can find different names. For example, a
1963 /// particular scope can have both a struct and a function of the same
1964 /// name, and each can be found by certain lookup criteria. For more
1965 /// information about lookup criteria, see the documentation for the
1966 /// class LookupCriteria.
1968 /// \param R captures both the lookup criteria and any lookup results found.
1970 /// \param LookupCtx The context in which qualified name lookup will
1971 /// search. If the lookup criteria permits, name lookup may also search
1972 /// in the parent contexts or (for C++ classes) base classes.
1974 /// \param InUnqualifiedLookup true if this is qualified name lookup that
1975 /// occurs as part of unqualified name lookup.
1977 /// \returns true if lookup succeeded, false if it failed.
1978 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
1979 bool InUnqualifiedLookup) {
1980 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
1982 if (!R.getLookupName())
1985 // Make sure that the declaration context is complete.
1986 assert((!isa<TagDecl>(LookupCtx) ||
1987 LookupCtx->isDependentContext() ||
1988 cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
1989 cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
1990 "Declaration context must already be complete!");
1992 struct QualifiedLookupInScope {
1994 DeclContext *Context;
1995 // Set flag in DeclContext informing debugger that we're looking for qualified name
1996 QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) {
1997 oldVal = ctx->setUseQualifiedLookup();
1999 ~QualifiedLookupInScope() {
2000 Context->setUseQualifiedLookup(oldVal);
2004 if (LookupDirect(*this, R, LookupCtx)) {
2006 if (isa<CXXRecordDecl>(LookupCtx))
2007 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
2011 // Don't descend into implied contexts for redeclarations.
2012 // C++98 [namespace.qual]p6:
2013 // In a declaration for a namespace member in which the
2014 // declarator-id is a qualified-id, given that the qualified-id
2015 // for the namespace member has the form
2016 // nested-name-specifier unqualified-id
2017 // the unqualified-id shall name a member of the namespace
2018 // designated by the nested-name-specifier.
2019 // See also [class.mfct]p5 and [class.static.data]p2.
2020 if (R.isForRedeclaration())
2023 // If this is a namespace, look it up in the implied namespaces.
2024 if (LookupCtx->isFileContext())
2025 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
2027 // If this isn't a C++ class, we aren't allowed to look into base
2028 // classes, we're done.
2029 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
2030 if (!LookupRec || !LookupRec->getDefinition())
2033 // If we're performing qualified name lookup into a dependent class,
2034 // then we are actually looking into a current instantiation. If we have any
2035 // dependent base classes, then we either have to delay lookup until
2036 // template instantiation time (at which point all bases will be available)
2037 // or we have to fail.
2038 if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
2039 LookupRec->hasAnyDependentBases()) {
2040 R.setNotFoundInCurrentInstantiation();
2044 // Perform lookup into our base classes.
2046 Paths.setOrigin(LookupRec);
2048 // Look for this member in our base classes
2049 bool (*BaseCallback)(const CXXBaseSpecifier *Specifier, CXXBasePath &Path,
2050 DeclarationName Name) = nullptr;
2051 switch (R.getLookupKind()) {
2052 case LookupObjCImplicitSelfParam:
2053 case LookupOrdinaryName:
2054 case LookupMemberName:
2055 case LookupRedeclarationWithLinkage:
2056 case LookupLocalFriendName:
2057 BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
2061 BaseCallback = &CXXRecordDecl::FindTagMember;
2065 BaseCallback = &LookupAnyMember;
2068 case LookupOMPReductionName:
2069 BaseCallback = &CXXRecordDecl::FindOMPReductionMember;
2072 case LookupUsingDeclName:
2073 // This lookup is for redeclarations only.
2075 case LookupOperatorName:
2076 case LookupNamespaceName:
2077 case LookupObjCProtocolName:
2079 // These lookups will never find a member in a C++ class (or base class).
2082 case LookupNestedNameSpecifierName:
2083 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember;
2087 DeclarationName Name = R.getLookupName();
2088 if (!LookupRec->lookupInBases(
2089 [=](const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
2090 return BaseCallback(Specifier, Path, Name);
2095 R.setNamingClass(LookupRec);
2097 // C++ [class.member.lookup]p2:
2098 // [...] If the resulting set of declarations are not all from
2099 // sub-objects of the same type, or the set has a nonstatic member
2100 // and includes members from distinct sub-objects, there is an
2101 // ambiguity and the program is ill-formed. Otherwise that set is
2102 // the result of the lookup.
2103 QualType SubobjectType;
2104 int SubobjectNumber = 0;
2105 AccessSpecifier SubobjectAccess = AS_none;
2107 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
2108 Path != PathEnd; ++Path) {
2109 const CXXBasePathElement &PathElement = Path->back();
2111 // Pick the best (i.e. most permissive i.e. numerically lowest) access
2112 // across all paths.
2113 SubobjectAccess = std::min(SubobjectAccess, Path->Access);
2115 // Determine whether we're looking at a distinct sub-object or not.
2116 if (SubobjectType.isNull()) {
2117 // This is the first subobject we've looked at. Record its type.
2118 SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
2119 SubobjectNumber = PathElement.SubobjectNumber;
2124 != Context.getCanonicalType(PathElement.Base->getType())) {
2125 // We found members of the given name in two subobjects of
2126 // different types. If the declaration sets aren't the same, this
2127 // lookup is ambiguous.
2128 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) {
2129 CXXBasePaths::paths_iterator FirstPath = Paths.begin();
2130 DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin();
2131 DeclContext::lookup_iterator CurrentD = Path->Decls.begin();
2133 while (FirstD != FirstPath->Decls.end() &&
2134 CurrentD != Path->Decls.end()) {
2135 if ((*FirstD)->getUnderlyingDecl()->getCanonicalDecl() !=
2136 (*CurrentD)->getUnderlyingDecl()->getCanonicalDecl())
2143 if (FirstD == FirstPath->Decls.end() &&
2144 CurrentD == Path->Decls.end())
2148 R.setAmbiguousBaseSubobjectTypes(Paths);
2152 if (SubobjectNumber != PathElement.SubobjectNumber) {
2153 // We have a different subobject of the same type.
2155 // C++ [class.member.lookup]p5:
2156 // A static member, a nested type or an enumerator defined in
2157 // a base class T can unambiguously be found even if an object
2158 // has more than one base class subobject of type T.
2159 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end()))
2162 // We have found a nonstatic member name in multiple, distinct
2163 // subobjects. Name lookup is ambiguous.
2164 R.setAmbiguousBaseSubobjects(Paths);
2169 // Lookup in a base class succeeded; return these results.
2171 for (auto *D : Paths.front().Decls) {
2172 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
2180 /// \brief Performs qualified name lookup or special type of lookup for
2181 /// "__super::" scope specifier.
2183 /// This routine is a convenience overload meant to be called from contexts
2184 /// that need to perform a qualified name lookup with an optional C++ scope
2185 /// specifier that might require special kind of lookup.
2187 /// \param R captures both the lookup criteria and any lookup results found.
2189 /// \param LookupCtx The context in which qualified name lookup will
2192 /// \param SS An optional C++ scope-specifier.
2194 /// \returns true if lookup succeeded, false if it failed.
2195 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2197 auto *NNS = SS.getScopeRep();
2198 if (NNS && NNS->getKind() == NestedNameSpecifier::Super)
2199 return LookupInSuper(R, NNS->getAsRecordDecl());
2202 return LookupQualifiedName(R, LookupCtx);
2205 /// @brief Performs name lookup for a name that was parsed in the
2206 /// source code, and may contain a C++ scope specifier.
2208 /// This routine is a convenience routine meant to be called from
2209 /// contexts that receive a name and an optional C++ scope specifier
2210 /// (e.g., "N::M::x"). It will then perform either qualified or
2211 /// unqualified name lookup (with LookupQualifiedName or LookupName,
2212 /// respectively) on the given name and return those results. It will
2213 /// perform a special type of lookup for "__super::" scope specifier.
2215 /// @param S The scope from which unqualified name lookup will
2218 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
2220 /// @param EnteringContext Indicates whether we are going to enter the
2221 /// context of the scope-specifier SS (if present).
2223 /// @returns True if any decls were found (but possibly ambiguous)
2224 bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
2225 bool AllowBuiltinCreation, bool EnteringContext) {
2226 if (SS && SS->isInvalid()) {
2227 // When the scope specifier is invalid, don't even look for
2232 if (SS && SS->isSet()) {
2233 NestedNameSpecifier *NNS = SS->getScopeRep();
2234 if (NNS->getKind() == NestedNameSpecifier::Super)
2235 return LookupInSuper(R, NNS->getAsRecordDecl());
2237 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
2238 // We have resolved the scope specifier to a particular declaration
2239 // contex, and will perform name lookup in that context.
2240 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
2243 R.setContextRange(SS->getRange());
2244 return LookupQualifiedName(R, DC);
2247 // We could not resolve the scope specified to a specific declaration
2248 // context, which means that SS refers to an unknown specialization.
2249 // Name lookup can't find anything in this case.
2250 R.setNotFoundInCurrentInstantiation();
2251 R.setContextRange(SS->getRange());
2255 // Perform unqualified name lookup starting in the given scope.
2256 return LookupName(R, S, AllowBuiltinCreation);
2259 /// \brief Perform qualified name lookup into all base classes of the given
2262 /// \param R captures both the lookup criteria and any lookup results found.
2264 /// \param Class The context in which qualified name lookup will
2265 /// search. Name lookup will search in all base classes merging the results.
2267 /// @returns True if any decls were found (but possibly ambiguous)
2268 bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) {
2269 // The access-control rules we use here are essentially the rules for
2270 // doing a lookup in Class that just magically skipped the direct
2271 // members of Class itself. That is, the naming class is Class, and the
2272 // access includes the access of the base.
2273 for (const auto &BaseSpec : Class->bases()) {
2274 CXXRecordDecl *RD = cast<CXXRecordDecl>(
2275 BaseSpec.getType()->castAs<RecordType>()->getDecl());
2276 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
2277 Result.setBaseObjectType(Context.getRecordType(Class));
2278 LookupQualifiedName(Result, RD);
2280 // Copy the lookup results into the target, merging the base's access into
2282 for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
2283 R.addDecl(I.getDecl(),
2284 CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(),
2288 Result.suppressDiagnostics();
2292 R.setNamingClass(Class);
2297 /// \brief Produce a diagnostic describing the ambiguity that resulted
2298 /// from name lookup.
2300 /// \param Result The result of the ambiguous lookup to be diagnosed.
2301 void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
2302 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
2304 DeclarationName Name = Result.getLookupName();
2305 SourceLocation NameLoc = Result.getNameLoc();
2306 SourceRange LookupRange = Result.getContextRange();
2308 switch (Result.getAmbiguityKind()) {
2309 case LookupResult::AmbiguousBaseSubobjects: {
2310 CXXBasePaths *Paths = Result.getBasePaths();
2311 QualType SubobjectType = Paths->front().back().Base->getType();
2312 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
2313 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
2316 DeclContext::lookup_iterator Found = Paths->front().Decls.begin();
2317 while (isa<CXXMethodDecl>(*Found) &&
2318 cast<CXXMethodDecl>(*Found)->isStatic())
2321 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
2325 case LookupResult::AmbiguousBaseSubobjectTypes: {
2326 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
2327 << Name << LookupRange;
2329 CXXBasePaths *Paths = Result.getBasePaths();
2330 std::set<Decl *> DeclsPrinted;
2331 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
2332 PathEnd = Paths->end();
2333 Path != PathEnd; ++Path) {
2334 Decl *D = Path->Decls.front();
2335 if (DeclsPrinted.insert(D).second)
2336 Diag(D->getLocation(), diag::note_ambiguous_member_found);
2341 case LookupResult::AmbiguousTagHiding: {
2342 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
2344 llvm::SmallPtrSet<NamedDecl*, 8> TagDecls;
2346 for (auto *D : Result)
2347 if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
2348 TagDecls.insert(TD);
2349 Diag(TD->getLocation(), diag::note_hidden_tag);
2352 for (auto *D : Result)
2353 if (!isa<TagDecl>(D))
2354 Diag(D->getLocation(), diag::note_hiding_object);
2356 // For recovery purposes, go ahead and implement the hiding.
2357 LookupResult::Filter F = Result.makeFilter();
2358 while (F.hasNext()) {
2359 if (TagDecls.count(F.next()))
2366 case LookupResult::AmbiguousReference: {
2367 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
2369 for (auto *D : Result)
2370 Diag(D->getLocation(), diag::note_ambiguous_candidate) << D;
2377 struct AssociatedLookup {
2378 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
2379 Sema::AssociatedNamespaceSet &Namespaces,
2380 Sema::AssociatedClassSet &Classes)
2381 : S(S), Namespaces(Namespaces), Classes(Classes),
2382 InstantiationLoc(InstantiationLoc) {
2386 Sema::AssociatedNamespaceSet &Namespaces;
2387 Sema::AssociatedClassSet &Classes;
2388 SourceLocation InstantiationLoc;
2390 } // end anonymous namespace
2393 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
2395 static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces,
2397 // Add the associated namespace for this class.
2399 // We don't use DeclContext::getEnclosingNamespaceContext() as this may
2400 // be a locally scoped record.
2402 // We skip out of inline namespaces. The innermost non-inline namespace
2403 // contains all names of all its nested inline namespaces anyway, so we can
2404 // replace the entire inline namespace tree with its root.
2405 while (Ctx->isRecord() || Ctx->isTransparentContext() ||
2406 Ctx->isInlineNamespace())
2407 Ctx = Ctx->getParent();
2409 if (Ctx->isFileContext())
2410 Namespaces.insert(Ctx->getPrimaryContext());
2413 // \brief Add the associated classes and namespaces for argument-dependent
2414 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2).
2416 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2417 const TemplateArgument &Arg) {
2418 // C++ [basic.lookup.koenig]p2, last bullet:
2420 switch (Arg.getKind()) {
2421 case TemplateArgument::Null:
2424 case TemplateArgument::Type:
2425 // [...] the namespaces and classes associated with the types of the
2426 // template arguments provided for template type parameters (excluding
2427 // template template parameters)
2428 addAssociatedClassesAndNamespaces(Result, Arg.getAsType());
2431 case TemplateArgument::Template:
2432 case TemplateArgument::TemplateExpansion: {
2433 // [...] the namespaces in which any template template arguments are
2434 // defined; and the classes in which any member templates used as
2435 // template template arguments are defined.
2436 TemplateName Template = Arg.getAsTemplateOrTemplatePattern();
2437 if (ClassTemplateDecl *ClassTemplate
2438 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
2439 DeclContext *Ctx = ClassTemplate->getDeclContext();
2440 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2441 Result.Classes.insert(EnclosingClass);
2442 // Add the associated namespace for this class.
2443 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2448 case TemplateArgument::Declaration:
2449 case TemplateArgument::Integral:
2450 case TemplateArgument::Expression:
2451 case TemplateArgument::NullPtr:
2452 // [Note: non-type template arguments do not contribute to the set of
2453 // associated namespaces. ]
2456 case TemplateArgument::Pack:
2457 for (const auto &P : Arg.pack_elements())
2458 addAssociatedClassesAndNamespaces(Result, P);
2463 // \brief Add the associated classes and namespaces for
2464 // argument-dependent lookup with an argument of class type
2465 // (C++ [basic.lookup.koenig]p2).
2467 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2468 CXXRecordDecl *Class) {
2470 // Just silently ignore anything whose name is __va_list_tag.
2471 if (Class->getDeclName() == Result.S.VAListTagName)
2474 // C++ [basic.lookup.koenig]p2:
2476 // -- If T is a class type (including unions), its associated
2477 // classes are: the class itself; the class of which it is a
2478 // member, if any; and its direct and indirect base
2479 // classes. Its associated namespaces are the namespaces in
2480 // which its associated classes are defined.
2482 // Add the class of which it is a member, if any.
2483 DeclContext *Ctx = Class->getDeclContext();
2484 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2485 Result.Classes.insert(EnclosingClass);
2486 // Add the associated namespace for this class.
2487 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2489 // Add the class itself. If we've already seen this class, we don't
2490 // need to visit base classes.
2492 // FIXME: That's not correct, we may have added this class only because it
2493 // was the enclosing class of another class, and in that case we won't have
2494 // added its base classes yet.
2495 if (!Result.Classes.insert(Class))
2498 // -- If T is a template-id, its associated namespaces and classes are
2499 // the namespace in which the template is defined; for member
2500 // templates, the member template's class; the namespaces and classes
2501 // associated with the types of the template arguments provided for
2502 // template type parameters (excluding template template parameters); the
2503 // namespaces in which any template template arguments are defined; and
2504 // the classes in which any member templates used as template template
2505 // arguments are defined. [Note: non-type template arguments do not
2506 // contribute to the set of associated namespaces. ]
2507 if (ClassTemplateSpecializationDecl *Spec
2508 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
2509 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
2510 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2511 Result.Classes.insert(EnclosingClass);
2512 // Add the associated namespace for this class.
2513 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2515 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
2516 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2517 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]);
2520 // Only recurse into base classes for complete types.
2521 if (!Result.S.isCompleteType(Result.InstantiationLoc,
2522 Result.S.Context.getRecordType(Class)))
2525 // Add direct and indirect base classes along with their associated
2527 SmallVector<CXXRecordDecl *, 32> Bases;
2528 Bases.push_back(Class);
2529 while (!Bases.empty()) {
2530 // Pop this class off the stack.
2531 Class = Bases.pop_back_val();
2533 // Visit the base classes.
2534 for (const auto &Base : Class->bases()) {
2535 const RecordType *BaseType = Base.getType()->getAs<RecordType>();
2536 // In dependent contexts, we do ADL twice, and the first time around,
2537 // the base type might be a dependent TemplateSpecializationType, or a
2538 // TemplateTypeParmType. If that happens, simply ignore it.
2539 // FIXME: If we want to support export, we probably need to add the
2540 // namespace of the template in a TemplateSpecializationType, or even
2541 // the classes and namespaces of known non-dependent arguments.
2544 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
2545 if (Result.Classes.insert(BaseDecl)) {
2546 // Find the associated namespace for this base class.
2547 DeclContext *BaseCtx = BaseDecl->getDeclContext();
2548 CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
2550 // Make sure we visit the bases of this base class.
2551 if (BaseDecl->bases_begin() != BaseDecl->bases_end())
2552 Bases.push_back(BaseDecl);
2558 // \brief Add the associated classes and namespaces for
2559 // argument-dependent lookup with an argument of type T
2560 // (C++ [basic.lookup.koenig]p2).
2562 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
2563 // C++ [basic.lookup.koenig]p2:
2565 // For each argument type T in the function call, there is a set
2566 // of zero or more associated namespaces and a set of zero or more
2567 // associated classes to be considered. The sets of namespaces and
2568 // classes is determined entirely by the types of the function
2569 // arguments (and the namespace of any template template
2570 // argument). Typedef names and using-declarations used to specify
2571 // the types do not contribute to this set. The sets of namespaces
2572 // and classes are determined in the following way:
2574 SmallVector<const Type *, 16> Queue;
2575 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
2578 switch (T->getTypeClass()) {
2580 #define TYPE(Class, Base)
2581 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
2582 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
2583 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
2584 #define ABSTRACT_TYPE(Class, Base)
2585 #include "clang/AST/TypeNodes.def"
2586 // T is canonical. We can also ignore dependent types because
2587 // we don't need to do ADL at the definition point, but if we
2588 // wanted to implement template export (or if we find some other
2589 // use for associated classes and namespaces...) this would be
2593 // -- If T is a pointer to U or an array of U, its associated
2594 // namespaces and classes are those associated with U.
2596 T = cast<PointerType>(T)->getPointeeType().getTypePtr();
2598 case Type::ConstantArray:
2599 case Type::IncompleteArray:
2600 case Type::VariableArray:
2601 T = cast<ArrayType>(T)->getElementType().getTypePtr();
2604 // -- If T is a fundamental type, its associated sets of
2605 // namespaces and classes are both empty.
2609 // -- If T is a class type (including unions), its associated
2610 // classes are: the class itself; the class of which it is a
2611 // member, if any; and its direct and indirect base
2612 // classes. Its associated namespaces are the namespaces in
2613 // which its associated classes are defined.
2614 case Type::Record: {
2615 CXXRecordDecl *Class =
2616 cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl());
2617 addAssociatedClassesAndNamespaces(Result, Class);
2621 // -- If T is an enumeration type, its associated namespace is
2622 // the namespace in which it is defined. If it is class
2623 // member, its associated class is the member's class; else
2624 // it has no associated class.
2626 EnumDecl *Enum = cast<EnumType>(T)->getDecl();
2628 DeclContext *Ctx = Enum->getDeclContext();
2629 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2630 Result.Classes.insert(EnclosingClass);
2632 // Add the associated namespace for this class.
2633 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2638 // -- If T is a function type, its associated namespaces and
2639 // classes are those associated with the function parameter
2640 // types and those associated with the return type.
2641 case Type::FunctionProto: {
2642 const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
2643 for (const auto &Arg : Proto->param_types())
2644 Queue.push_back(Arg.getTypePtr());
2647 case Type::FunctionNoProto: {
2648 const FunctionType *FnType = cast<FunctionType>(T);
2649 T = FnType->getReturnType().getTypePtr();
2653 // -- If T is a pointer to a member function of a class X, its
2654 // associated namespaces and classes are those associated
2655 // with the function parameter types and return type,
2656 // together with those associated with X.
2658 // -- If T is a pointer to a data member of class X, its
2659 // associated namespaces and classes are those associated
2660 // with the member type together with those associated with
2662 case Type::MemberPointer: {
2663 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T);
2665 // Queue up the class type into which this points.
2666 Queue.push_back(MemberPtr->getClass());
2668 // And directly continue with the pointee type.
2669 T = MemberPtr->getPointeeType().getTypePtr();
2673 // As an extension, treat this like a normal pointer.
2674 case Type::BlockPointer:
2675 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr();
2678 // References aren't covered by the standard, but that's such an
2679 // obvious defect that we cover them anyway.
2680 case Type::LValueReference:
2681 case Type::RValueReference:
2682 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr();
2685 // These are fundamental types.
2687 case Type::ExtVector:
2691 // Non-deduced auto types only get here for error cases.
2693 case Type::DeducedTemplateSpecialization:
2696 // If T is an Objective-C object or interface type, or a pointer to an
2697 // object or interface type, the associated namespace is the global
2699 case Type::ObjCObject:
2700 case Type::ObjCInterface:
2701 case Type::ObjCObjectPointer:
2702 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
2705 // Atomic types are just wrappers; use the associations of the
2708 T = cast<AtomicType>(T)->getValueType().getTypePtr();
2711 T = cast<PipeType>(T)->getElementType().getTypePtr();
2717 T = Queue.pop_back_val();
2721 /// \brief Find the associated classes and namespaces for
2722 /// argument-dependent lookup for a call with the given set of
2725 /// This routine computes the sets of associated classes and associated
2726 /// namespaces searched by argument-dependent lookup
2727 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
2728 void Sema::FindAssociatedClassesAndNamespaces(
2729 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
2730 AssociatedNamespaceSet &AssociatedNamespaces,
2731 AssociatedClassSet &AssociatedClasses) {
2732 AssociatedNamespaces.clear();
2733 AssociatedClasses.clear();
2735 AssociatedLookup Result(*this, InstantiationLoc,
2736 AssociatedNamespaces, AssociatedClasses);
2738 // C++ [basic.lookup.koenig]p2:
2739 // For each argument type T in the function call, there is a set
2740 // of zero or more associated namespaces and a set of zero or more
2741 // associated classes to be considered. The sets of namespaces and
2742 // classes is determined entirely by the types of the function
2743 // arguments (and the namespace of any template template
2745 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
2746 Expr *Arg = Args[ArgIdx];
2748 if (Arg->getType() != Context.OverloadTy) {
2749 addAssociatedClassesAndNamespaces(Result, Arg->getType());
2753 // [...] In addition, if the argument is the name or address of a
2754 // set of overloaded functions and/or function templates, its
2755 // associated classes and namespaces are the union of those
2756 // associated with each of the members of the set: the namespace
2757 // in which the function or function template is defined and the
2758 // classes and namespaces associated with its (non-dependent)
2759 // parameter types and return type.
2760 Arg = Arg->IgnoreParens();
2761 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg))
2762 if (unaryOp->getOpcode() == UO_AddrOf)
2763 Arg = unaryOp->getSubExpr();
2765 UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg);
2768 for (const auto *D : ULE->decls()) {
2769 // Look through any using declarations to find the underlying function.
2770 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
2772 // Add the classes and namespaces associated with the parameter
2773 // types and return type of this function.
2774 addAssociatedClassesAndNamespaces(Result, FDecl->getType());
2779 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
2781 LookupNameKind NameKind,
2782 RedeclarationKind Redecl) {
2783 LookupResult R(*this, Name, Loc, NameKind, Redecl);
2785 return R.getAsSingle<NamedDecl>();
2788 /// \brief Find the protocol with the given name, if any.
2789 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II,
2790 SourceLocation IdLoc,
2791 RedeclarationKind Redecl) {
2792 Decl *D = LookupSingleName(TUScope, II, IdLoc,
2793 LookupObjCProtocolName, Redecl);
2794 return cast_or_null<ObjCProtocolDecl>(D);
2797 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
2798 QualType T1, QualType T2,
2799 UnresolvedSetImpl &Functions) {
2800 // C++ [over.match.oper]p3:
2801 // -- The set of non-member candidates is the result of the
2802 // unqualified lookup of operator@ in the context of the
2803 // expression according to the usual rules for name lookup in
2804 // unqualified function calls (3.4.2) except that all member
2805 // functions are ignored.
2806 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
2807 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
2808 LookupName(Operators, S);
2810 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
2811 Functions.append(Operators.begin(), Operators.end());
2814 Sema::SpecialMemberOverloadResult Sema::LookupSpecialMember(CXXRecordDecl *RD,
2815 CXXSpecialMember SM,
2820 bool VolatileThis) {
2821 assert(CanDeclareSpecialMemberFunction(RD) &&
2822 "doing special member lookup into record that isn't fully complete");
2823 RD = RD->getDefinition();
2824 if (RValueThis || ConstThis || VolatileThis)
2825 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) &&
2826 "constructors and destructors always have unqualified lvalue this");
2827 if (ConstArg || VolatileArg)
2828 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) &&
2829 "parameter-less special members can't have qualified arguments");
2831 // FIXME: Get the caller to pass in a location for the lookup.
2832 SourceLocation LookupLoc = RD->getLocation();
2834 llvm::FoldingSetNodeID ID;
2837 ID.AddInteger(ConstArg);
2838 ID.AddInteger(VolatileArg);
2839 ID.AddInteger(RValueThis);
2840 ID.AddInteger(ConstThis);
2841 ID.AddInteger(VolatileThis);
2844 SpecialMemberOverloadResultEntry *Result =
2845 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
2847 // This was already cached
2851 Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>();
2852 Result = new (Result) SpecialMemberOverloadResultEntry(ID);
2853 SpecialMemberCache.InsertNode(Result, InsertPoint);
2855 if (SM == CXXDestructor) {
2856 if (RD->needsImplicitDestructor())
2857 DeclareImplicitDestructor(RD);
2858 CXXDestructorDecl *DD = RD->getDestructor();
2859 assert(DD && "record without a destructor");
2860 Result->setMethod(DD);
2861 Result->setKind(DD->isDeleted() ?
2862 SpecialMemberOverloadResult::NoMemberOrDeleted :
2863 SpecialMemberOverloadResult::Success);
2867 // Prepare for overload resolution. Here we construct a synthetic argument
2868 // if necessary and make sure that implicit functions are declared.
2869 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD));
2870 DeclarationName Name;
2871 Expr *Arg = nullptr;
2874 QualType ArgType = CanTy;
2875 ExprValueKind VK = VK_LValue;
2877 if (SM == CXXDefaultConstructor) {
2878 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2880 if (RD->needsImplicitDefaultConstructor())
2881 DeclareImplicitDefaultConstructor(RD);
2883 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) {
2884 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2885 if (RD->needsImplicitCopyConstructor())
2886 DeclareImplicitCopyConstructor(RD);
2887 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor())
2888 DeclareImplicitMoveConstructor(RD);
2890 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
2891 if (RD->needsImplicitCopyAssignment())
2892 DeclareImplicitCopyAssignment(RD);
2893 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment())
2894 DeclareImplicitMoveAssignment(RD);
2900 ArgType.addVolatile();
2902 // This isn't /really/ specified by the standard, but it's implied
2903 // we should be working from an RValue in the case of move to ensure
2904 // that we prefer to bind to rvalue references, and an LValue in the
2905 // case of copy to ensure we don't bind to rvalue references.
2906 // Possibly an XValue is actually correct in the case of move, but
2907 // there is no semantic difference for class types in this restricted
2909 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment)
2915 OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK);
2917 if (SM != CXXDefaultConstructor) {
2922 // Create the object argument
2923 QualType ThisTy = CanTy;
2927 ThisTy.addVolatile();
2928 Expr::Classification Classification =
2929 OpaqueValueExpr(LookupLoc, ThisTy,
2930 RValueThis ? VK_RValue : VK_LValue).Classify(Context);
2932 // Now we perform lookup on the name we computed earlier and do overload
2933 // resolution. Lookup is only performed directly into the class since there
2934 // will always be a (possibly implicit) declaration to shadow any others.
2935 OverloadCandidateSet OCS(LookupLoc, OverloadCandidateSet::CSK_Normal);
2936 DeclContext::lookup_result R = RD->lookup(Name);
2939 // We might have no default constructor because we have a lambda's closure
2940 // type, rather than because there's some other declared constructor.
2941 // Every class has a copy/move constructor, copy/move assignment, and
2943 assert(SM == CXXDefaultConstructor &&
2944 "lookup for a constructor or assignment operator was empty");
2945 Result->setMethod(nullptr);
2946 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2950 // Copy the candidates as our processing of them may load new declarations
2951 // from an external source and invalidate lookup_result.
2952 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
2954 for (NamedDecl *CandDecl : Candidates) {
2955 if (CandDecl->isInvalidDecl())
2958 DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public);
2959 auto CtorInfo = getConstructorInfo(Cand);
2960 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl())) {
2961 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2962 AddMethodCandidate(M, Cand, RD, ThisTy, Classification,
2963 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2965 AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl,
2966 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2968 AddOverloadCandidate(M, Cand, llvm::makeArrayRef(&Arg, NumArgs), OCS,
2970 } else if (FunctionTemplateDecl *Tmpl =
2971 dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) {
2972 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2973 AddMethodTemplateCandidate(
2974 Tmpl, Cand, RD, nullptr, ThisTy, Classification,
2975 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2977 AddTemplateOverloadCandidate(
2978 CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr,
2979 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2981 AddTemplateOverloadCandidate(
2982 Tmpl, Cand, nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2984 assert(isa<UsingDecl>(Cand.getDecl()) &&
2985 "illegal Kind of operator = Decl");
2989 OverloadCandidateSet::iterator Best;
2990 switch (OCS.BestViableFunction(*this, LookupLoc, Best)) {
2992 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
2993 Result->setKind(SpecialMemberOverloadResult::Success);
2997 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
2998 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3002 Result->setMethod(nullptr);
3003 Result->setKind(SpecialMemberOverloadResult::Ambiguous);
3006 case OR_No_Viable_Function:
3007 Result->setMethod(nullptr);
3008 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3015 /// \brief Look up the default constructor for the given class.
3016 CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) {
3017 SpecialMemberOverloadResult Result =
3018 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false,
3021 return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3024 /// \brief Look up the copying constructor for the given class.
3025 CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class,
3027 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3028 "non-const, non-volatile qualifiers for copy ctor arg");
3029 SpecialMemberOverloadResult Result =
3030 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const,
3031 Quals & Qualifiers::Volatile, false, false, false);
3033 return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3036 /// \brief Look up the moving constructor for the given class.
3037 CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class,
3039 SpecialMemberOverloadResult Result =
3040 LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const,
3041 Quals & Qualifiers::Volatile, false, false, false);
3043 return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3046 /// \brief Look up the constructors for the given class.
3047 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) {
3048 // If the implicit constructors have not yet been declared, do so now.
3049 if (CanDeclareSpecialMemberFunction(Class)) {
3050 if (Class->needsImplicitDefaultConstructor())
3051 DeclareImplicitDefaultConstructor(Class);
3052 if (Class->needsImplicitCopyConstructor())
3053 DeclareImplicitCopyConstructor(Class);
3054 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
3055 DeclareImplicitMoveConstructor(Class);
3058 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class));
3059 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T);
3060 return Class->lookup(Name);
3063 /// \brief Look up the copying assignment operator for the given class.
3064 CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class,
3065 unsigned Quals, bool RValueThis,
3066 unsigned ThisQuals) {
3067 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3068 "non-const, non-volatile qualifiers for copy assignment arg");
3069 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3070 "non-const, non-volatile qualifiers for copy assignment this");
3071 SpecialMemberOverloadResult Result =
3072 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const,
3073 Quals & Qualifiers::Volatile, RValueThis,
3074 ThisQuals & Qualifiers::Const,
3075 ThisQuals & Qualifiers::Volatile);
3077 return Result.getMethod();
3080 /// \brief Look up the moving assignment operator for the given class.
3081 CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class,
3084 unsigned ThisQuals) {
3085 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3086 "non-const, non-volatile qualifiers for copy assignment this");
3087 SpecialMemberOverloadResult Result =
3088 LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const,
3089 Quals & Qualifiers::Volatile, RValueThis,
3090 ThisQuals & Qualifiers::Const,
3091 ThisQuals & Qualifiers::Volatile);
3093 return Result.getMethod();
3096 /// \brief Look for the destructor of the given class.
3098 /// During semantic analysis, this routine should be used in lieu of
3099 /// CXXRecordDecl::getDestructor().
3101 /// \returns The destructor for this class.
3102 CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) {
3103 return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor,
3104 false, false, false,
3105 false, false).getMethod());
3108 /// LookupLiteralOperator - Determine which literal operator should be used for
3109 /// a user-defined literal, per C++11 [lex.ext].
3111 /// Normal overload resolution is not used to select which literal operator to
3112 /// call for a user-defined literal. Look up the provided literal operator name,
3113 /// and filter the results to the appropriate set for the given argument types.
3114 Sema::LiteralOperatorLookupResult
3115 Sema::LookupLiteralOperator(Scope *S, LookupResult &R,
3116 ArrayRef<QualType> ArgTys,
3117 bool AllowRaw, bool AllowTemplate,
3118 bool AllowStringTemplate) {
3120 assert(R.getResultKind() != LookupResult::Ambiguous &&
3121 "literal operator lookup can't be ambiguous");
3123 // Filter the lookup results appropriately.
3124 LookupResult::Filter F = R.makeFilter();
3126 bool FoundRaw = false;
3127 bool FoundTemplate = false;
3128 bool FoundStringTemplate = false;
3129 bool FoundExactMatch = false;
3131 while (F.hasNext()) {
3133 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
3134 D = USD->getTargetDecl();
3136 // If the declaration we found is invalid, skip it.
3137 if (D->isInvalidDecl()) {
3143 bool IsTemplate = false;
3144 bool IsStringTemplate = false;
3145 bool IsExactMatch = false;
3147 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
3148 if (FD->getNumParams() == 1 &&
3149 FD->getParamDecl(0)->getType()->getAs<PointerType>())
3151 else if (FD->getNumParams() == ArgTys.size()) {
3152 IsExactMatch = true;
3153 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
3154 QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
3155 if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
3156 IsExactMatch = false;
3162 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) {
3163 TemplateParameterList *Params = FD->getTemplateParameters();
3164 if (Params->size() == 1)
3167 IsStringTemplate = true;
3171 FoundExactMatch = true;
3173 AllowTemplate = false;
3174 AllowStringTemplate = false;
3175 if (FoundRaw || FoundTemplate || FoundStringTemplate) {
3176 // Go through again and remove the raw and template decls we've
3179 FoundRaw = FoundTemplate = FoundStringTemplate = false;
3181 } else if (AllowRaw && IsRaw) {
3183 } else if (AllowTemplate && IsTemplate) {
3184 FoundTemplate = true;
3185 } else if (AllowStringTemplate && IsStringTemplate) {
3186 FoundStringTemplate = true;
3194 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
3195 // parameter type, that is used in preference to a raw literal operator
3196 // or literal operator template.
3197 if (FoundExactMatch)
3200 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
3201 // operator template, but not both.
3202 if (FoundRaw && FoundTemplate) {
3203 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
3204 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
3205 NoteOverloadCandidate(*I, (*I)->getUnderlyingDecl()->getAsFunction());
3213 return LOLR_Template;
3215 if (FoundStringTemplate)
3216 return LOLR_StringTemplate;
3218 // Didn't find anything we could use.
3219 Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
3220 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
3221 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
3222 << (AllowTemplate || AllowStringTemplate);
3226 void ADLResult::insert(NamedDecl *New) {
3227 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
3229 // If we haven't yet seen a decl for this key, or the last decl
3230 // was exactly this one, we're done.
3231 if (Old == nullptr || Old == New) {
3236 // Otherwise, decide which is a more recent redeclaration.
3237 FunctionDecl *OldFD = Old->getAsFunction();
3238 FunctionDecl *NewFD = New->getAsFunction();
3240 FunctionDecl *Cursor = NewFD;
3242 Cursor = Cursor->getPreviousDecl();
3244 // If we got to the end without finding OldFD, OldFD is the newer
3245 // declaration; leave things as they are.
3246 if (!Cursor) return;
3248 // If we do find OldFD, then NewFD is newer.
3249 if (Cursor == OldFD) break;
3251 // Otherwise, keep looking.
3257 void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
3258 ArrayRef<Expr *> Args, ADLResult &Result) {
3259 // Find all of the associated namespaces and classes based on the
3260 // arguments we have.
3261 AssociatedNamespaceSet AssociatedNamespaces;
3262 AssociatedClassSet AssociatedClasses;
3263 FindAssociatedClassesAndNamespaces(Loc, Args,
3264 AssociatedNamespaces,
3267 // C++ [basic.lookup.argdep]p3:
3268 // Let X be the lookup set produced by unqualified lookup (3.4.1)
3269 // and let Y be the lookup set produced by argument dependent
3270 // lookup (defined as follows). If X contains [...] then Y is
3271 // empty. Otherwise Y is the set of declarations found in the
3272 // namespaces associated with the argument types as described
3273 // below. The set of declarations found by the lookup of the name
3274 // is the union of X and Y.
3276 // Here, we compute Y and add its members to the overloaded
3278 for (auto *NS : AssociatedNamespaces) {
3279 // When considering an associated namespace, the lookup is the
3280 // same as the lookup performed when the associated namespace is
3281 // used as a qualifier (3.4.3.2) except that:
3283 // -- Any using-directives in the associated namespace are
3286 // -- Any namespace-scope friend functions declared in
3287 // associated classes are visible within their respective
3288 // namespaces even if they are not visible during an ordinary
3290 DeclContext::lookup_result R = NS->lookup(Name);
3292 // If the only declaration here is an ordinary friend, consider
3293 // it only if it was declared in an associated classes.
3294 if ((D->getIdentifierNamespace() & Decl::IDNS_Ordinary) == 0) {
3295 // If it's neither ordinarily visible nor a friend, we can't find it.
3296 if ((D->getIdentifierNamespace() & Decl::IDNS_OrdinaryFriend) == 0)
3299 bool DeclaredInAssociatedClass = false;
3300 for (Decl *DI = D; DI; DI = DI->getPreviousDecl()) {
3301 DeclContext *LexDC = DI->getLexicalDeclContext();
3302 if (isa<CXXRecordDecl>(LexDC) &&
3303 AssociatedClasses.count(cast<CXXRecordDecl>(LexDC)) &&
3304 isVisible(cast<NamedDecl>(DI))) {
3305 DeclaredInAssociatedClass = true;
3309 if (!DeclaredInAssociatedClass)
3313 if (isa<UsingShadowDecl>(D))
3314 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3316 if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D))
3319 if (!isVisible(D) && !(D = findAcceptableDecl(*this, D)))
3327 //----------------------------------------------------------------------------
3328 // Search for all visible declarations.
3329 //----------------------------------------------------------------------------
3330 VisibleDeclConsumer::~VisibleDeclConsumer() { }
3332 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
3336 class ShadowContextRAII;
3338 class VisibleDeclsRecord {
3340 /// \brief An entry in the shadow map, which is optimized to store a
3341 /// single declaration (the common case) but can also store a list
3342 /// of declarations.
3343 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
3346 /// \brief A mapping from declaration names to the declarations that have
3347 /// this name within a particular scope.
3348 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
3350 /// \brief A list of shadow maps, which is used to model name hiding.
3351 std::list<ShadowMap> ShadowMaps;
3353 /// \brief The declaration contexts we have already visited.
3354 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
3356 friend class ShadowContextRAII;
3359 /// \brief Determine whether we have already visited this context
3360 /// (and, if not, note that we are going to visit that context now).
3361 bool visitedContext(DeclContext *Ctx) {
3362 return !VisitedContexts.insert(Ctx).second;
3365 bool alreadyVisitedContext(DeclContext *Ctx) {
3366 return VisitedContexts.count(Ctx);
3369 /// \brief Determine whether the given declaration is hidden in the
3372 /// \returns the declaration that hides the given declaration, or
3373 /// NULL if no such declaration exists.
3374 NamedDecl *checkHidden(NamedDecl *ND);
3376 /// \brief Add a declaration to the current shadow map.
3377 void add(NamedDecl *ND) {
3378 ShadowMaps.back()[ND->getDeclName()].push_back(ND);
3382 /// \brief RAII object that records when we've entered a shadow context.
3383 class ShadowContextRAII {
3384 VisibleDeclsRecord &Visible;
3386 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
3389 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
3390 Visible.ShadowMaps.emplace_back();
3393 ~ShadowContextRAII() {
3394 Visible.ShadowMaps.pop_back();
3398 } // end anonymous namespace
3400 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
3401 unsigned IDNS = ND->getIdentifierNamespace();
3402 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
3403 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
3404 SM != SMEnd; ++SM) {
3405 ShadowMap::iterator Pos = SM->find(ND->getDeclName());
3406 if (Pos == SM->end())
3409 for (auto *D : Pos->second) {
3410 // A tag declaration does not hide a non-tag declaration.
3411 if (D->hasTagIdentifierNamespace() &&
3412 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
3413 Decl::IDNS_ObjCProtocol)))
3416 // Protocols are in distinct namespaces from everything else.
3417 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
3418 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
3419 D->getIdentifierNamespace() != IDNS)
3422 // Functions and function templates in the same scope overload
3423 // rather than hide. FIXME: Look for hiding based on function
3425 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3426 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3427 SM == ShadowMaps.rbegin())
3430 // A shadow declaration that's created by a resolved using declaration
3431 // is not hidden by the same using declaration.
3432 if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) &&
3433 cast<UsingShadowDecl>(ND)->getUsingDecl() == D)
3436 // We've found a declaration that hides this one.
3444 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
3445 bool QualifiedNameLookup,
3447 VisibleDeclConsumer &Consumer,
3448 VisibleDeclsRecord &Visited) {
3452 // Make sure we don't visit the same context twice.
3453 if (Visited.visitedContext(Ctx->getPrimaryContext()))
3456 // Outside C++, lookup results for the TU live on identifiers.
3457 if (isa<TranslationUnitDecl>(Ctx) &&
3458 !Result.getSema().getLangOpts().CPlusPlus) {
3459 auto &S = Result.getSema();
3460 auto &Idents = S.Context.Idents;
3462 // Ensure all external identifiers are in the identifier table.
3463 if (IdentifierInfoLookup *External = Idents.getExternalIdentifierLookup()) {
3464 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
3465 for (StringRef Name = Iter->Next(); !Name.empty(); Name = Iter->Next())
3469 // Walk all lookup results in the TU for each identifier.
3470 for (const auto &Ident : Idents) {
3471 for (auto I = S.IdResolver.begin(Ident.getValue()),
3472 E = S.IdResolver.end();
3474 if (S.IdResolver.isDeclInScope(*I, Ctx)) {
3475 if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
3476 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3486 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
3487 Result.getSema().ForceDeclarationOfImplicitMembers(Class);
3489 // Enumerate all of the results in this context.
3490 for (DeclContextLookupResult R : Ctx->lookups()) {
3492 if (auto *ND = Result.getAcceptableDecl(D)) {
3493 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3499 // Traverse using directives for qualified name lookup.
3500 if (QualifiedNameLookup) {
3501 ShadowContextRAII Shadow(Visited);
3502 for (auto I : Ctx->using_directives()) {
3503 LookupVisibleDecls(I->getNominatedNamespace(), Result,
3504 QualifiedNameLookup, InBaseClass, Consumer, Visited);
3508 // Traverse the contexts of inherited C++ classes.
3509 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
3510 if (!Record->hasDefinition())
3513 for (const auto &B : Record->bases()) {
3514 QualType BaseType = B.getType();
3516 // Don't look into dependent bases, because name lookup can't look
3518 if (BaseType->isDependentType())
3521 const RecordType *Record = BaseType->getAs<RecordType>();
3525 // FIXME: It would be nice to be able to determine whether referencing
3526 // a particular member would be ambiguous. For example, given
3528 // struct A { int member; };
3529 // struct B { int member; };
3530 // struct C : A, B { };
3532 // void f(C *c) { c->### }
3534 // accessing 'member' would result in an ambiguity. However, we
3535 // could be smart enough to qualify the member with the base
3544 // Find results in this base class (and its bases).
3545 ShadowContextRAII Shadow(Visited);
3546 LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup,
3547 true, Consumer, Visited);
3551 // Traverse the contexts of Objective-C classes.
3552 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
3553 // Traverse categories.
3554 for (auto *Cat : IFace->visible_categories()) {
3555 ShadowContextRAII Shadow(Visited);
3556 LookupVisibleDecls(Cat, Result, QualifiedNameLookup, false,
3560 // Traverse protocols.
3561 for (auto *I : IFace->all_referenced_protocols()) {
3562 ShadowContextRAII Shadow(Visited);
3563 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3567 // Traverse the superclass.
3568 if (IFace->getSuperClass()) {
3569 ShadowContextRAII Shadow(Visited);
3570 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup,
3571 true, Consumer, Visited);
3574 // If there is an implementation, traverse it. We do this to find
3575 // synthesized ivars.
3576 if (IFace->getImplementation()) {
3577 ShadowContextRAII Shadow(Visited);
3578 LookupVisibleDecls(IFace->getImplementation(), Result,
3579 QualifiedNameLookup, InBaseClass, Consumer, Visited);
3581 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
3582 for (auto *I : Protocol->protocols()) {
3583 ShadowContextRAII Shadow(Visited);
3584 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3587 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
3588 for (auto *I : Category->protocols()) {
3589 ShadowContextRAII Shadow(Visited);
3590 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3594 // If there is an implementation, traverse it.
3595 if (Category->getImplementation()) {
3596 ShadowContextRAII Shadow(Visited);
3597 LookupVisibleDecls(Category->getImplementation(), Result,
3598 QualifiedNameLookup, true, Consumer, Visited);
3603 static void LookupVisibleDecls(Scope *S, LookupResult &Result,
3604 UnqualUsingDirectiveSet &UDirs,
3605 VisibleDeclConsumer &Consumer,
3606 VisibleDeclsRecord &Visited) {
3610 if (!S->getEntity() ||
3612 !Visited.alreadyVisitedContext(S->getEntity())) ||
3613 (S->getEntity())->isFunctionOrMethod()) {
3614 FindLocalExternScope FindLocals(Result);
3615 // Walk through the declarations in this Scope.
3616 for (auto *D : S->decls()) {
3617 if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
3618 if ((ND = Result.getAcceptableDecl(ND))) {
3619 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
3625 // FIXME: C++ [temp.local]p8
3626 DeclContext *Entity = nullptr;
3627 if (S->getEntity()) {
3628 // Look into this scope's declaration context, along with any of its
3629 // parent lookup contexts (e.g., enclosing classes), up to the point
3630 // where we hit the context stored in the next outer scope.
3631 Entity = S->getEntity();
3632 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME
3634 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
3635 Ctx = Ctx->getLookupParent()) {
3636 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
3637 if (Method->isInstanceMethod()) {
3638 // For instance methods, look for ivars in the method's interface.
3639 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
3640 Result.getNameLoc(), Sema::LookupMemberName);
3641 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
3642 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false,
3643 /*InBaseClass=*/false, Consumer, Visited);
3647 // We've already performed all of the name lookup that we need
3648 // to for Objective-C methods; the next context will be the
3653 if (Ctx->isFunctionOrMethod())
3656 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false,
3657 /*InBaseClass=*/false, Consumer, Visited);
3659 } else if (!S->getParent()) {
3660 // Look into the translation unit scope. We walk through the translation
3661 // unit's declaration context, because the Scope itself won't have all of
3662 // the declarations if we loaded a precompiled header.
3663 // FIXME: We would like the translation unit's Scope object to point to the
3664 // translation unit, so we don't need this special "if" branch. However,
3665 // doing so would force the normal C++ name-lookup code to look into the
3666 // translation unit decl when the IdentifierInfo chains would suffice.
3667 // Once we fix that problem (which is part of a more general "don't look
3668 // in DeclContexts unless we have to" optimization), we can eliminate this.
3669 Entity = Result.getSema().Context.getTranslationUnitDecl();
3670 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false,
3671 /*InBaseClass=*/false, Consumer, Visited);
3675 // Lookup visible declarations in any namespaces found by using
3677 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity))
3678 LookupVisibleDecls(const_cast<DeclContext *>(UUE.getNominatedNamespace()),
3679 Result, /*QualifiedNameLookup=*/false,
3680 /*InBaseClass=*/false, Consumer, Visited);
3683 // Lookup names in the parent scope.
3684 ShadowContextRAII Shadow(Visited);
3685 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited);
3688 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
3689 VisibleDeclConsumer &Consumer,
3690 bool IncludeGlobalScope) {
3691 // Determine the set of using directives available during
3692 // unqualified name lookup.
3694 UnqualUsingDirectiveSet UDirs;
3695 if (getLangOpts().CPlusPlus) {
3696 // Find the first namespace or translation-unit scope.
3697 while (S && !isNamespaceOrTranslationUnitScope(S))
3700 UDirs.visitScopeChain(Initial, S);
3704 // Look for visible declarations.
3705 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3706 Result.setAllowHidden(Consumer.includeHiddenDecls());
3707 VisibleDeclsRecord Visited;
3708 if (!IncludeGlobalScope)
3709 Visited.visitedContext(Context.getTranslationUnitDecl());
3710 ShadowContextRAII Shadow(Visited);
3711 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited);
3714 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
3715 VisibleDeclConsumer &Consumer,
3716 bool IncludeGlobalScope) {
3717 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3718 Result.setAllowHidden(Consumer.includeHiddenDecls());
3719 VisibleDeclsRecord Visited;
3720 if (!IncludeGlobalScope)
3721 Visited.visitedContext(Context.getTranslationUnitDecl());
3722 ShadowContextRAII Shadow(Visited);
3723 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true,
3724 /*InBaseClass=*/false, Consumer, Visited);
3727 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name.
3728 /// If GnuLabelLoc is a valid source location, then this is a definition
3729 /// of an __label__ label name, otherwise it is a normal label definition
3731 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc,
3732 SourceLocation GnuLabelLoc) {
3733 // Do a lookup to see if we have a label with this name already.
3734 NamedDecl *Res = nullptr;
3736 if (GnuLabelLoc.isValid()) {
3737 // Local label definitions always shadow existing labels.
3738 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
3739 Scope *S = CurScope;
3740 PushOnScopeChains(Res, S, true);
3741 return cast<LabelDecl>(Res);
3744 // Not a GNU local label.
3745 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration);
3746 // If we found a label, check to see if it is in the same context as us.
3747 // When in a Block, we don't want to reuse a label in an enclosing function.
3748 if (Res && Res->getDeclContext() != CurContext)
3751 // If not forward referenced or defined already, create the backing decl.
3752 Res = LabelDecl::Create(Context, CurContext, Loc, II);
3753 Scope *S = CurScope->getFnParent();
3754 assert(S && "Not in a function?");
3755 PushOnScopeChains(Res, S, true);
3757 return cast<LabelDecl>(Res);
3760 //===----------------------------------------------------------------------===//
3762 //===----------------------------------------------------------------------===//
3764 static bool isCandidateViable(CorrectionCandidateCallback &CCC,
3765 TypoCorrection &Candidate) {
3766 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
3767 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
3770 static void LookupPotentialTypoResult(Sema &SemaRef,
3772 IdentifierInfo *Name,
3773 Scope *S, CXXScopeSpec *SS,
3774 DeclContext *MemberContext,
3775 bool EnteringContext,
3776 bool isObjCIvarLookup,
3779 /// \brief Check whether the declarations found for a typo correction are
3780 /// visible, and if none of them are, convert the correction to an 'import
3781 /// a module' correction.
3782 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
3783 if (TC.begin() == TC.end())
3786 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
3788 for (/**/; DI != DE; ++DI)
3789 if (!LookupResult::isVisible(SemaRef, *DI))
3791 // Nothing to do if all decls are visible.
3795 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
3796 bool AnyVisibleDecls = !NewDecls.empty();
3798 for (/**/; DI != DE; ++DI) {
3799 NamedDecl *VisibleDecl = *DI;
3800 if (!LookupResult::isVisible(SemaRef, *DI))
3801 VisibleDecl = findAcceptableDecl(SemaRef, *DI);
3804 if (!AnyVisibleDecls) {
3805 // Found a visible decl, discard all hidden ones.
3806 AnyVisibleDecls = true;
3809 NewDecls.push_back(VisibleDecl);
3810 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
3811 NewDecls.push_back(*DI);
3814 if (NewDecls.empty())
3815 TC = TypoCorrection();
3817 TC.setCorrectionDecls(NewDecls);
3818 TC.setRequiresImport(!AnyVisibleDecls);
3822 // Fill the supplied vector with the IdentifierInfo pointers for each piece of
3823 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
3824 // fill the vector with the IdentifierInfo pointers for "foo" and "bar").
3825 static void getNestedNameSpecifierIdentifiers(
3826 NestedNameSpecifier *NNS,
3827 SmallVectorImpl<const IdentifierInfo*> &Identifiers) {
3828 if (NestedNameSpecifier *Prefix = NNS->getPrefix())
3829 getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
3831 Identifiers.clear();
3833 const IdentifierInfo *II = nullptr;
3835 switch (NNS->getKind()) {
3836 case NestedNameSpecifier::Identifier:
3837 II = NNS->getAsIdentifier();
3840 case NestedNameSpecifier::Namespace:
3841 if (NNS->getAsNamespace()->isAnonymousNamespace())
3843 II = NNS->getAsNamespace()->getIdentifier();
3846 case NestedNameSpecifier::NamespaceAlias:
3847 II = NNS->getAsNamespaceAlias()->getIdentifier();
3850 case NestedNameSpecifier::TypeSpecWithTemplate:
3851 case NestedNameSpecifier::TypeSpec:
3852 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier();
3855 case NestedNameSpecifier::Global:
3856 case NestedNameSpecifier::Super:
3861 Identifiers.push_back(II);
3864 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
3865 DeclContext *Ctx, bool InBaseClass) {
3866 // Don't consider hidden names for typo correction.
3870 // Only consider entities with identifiers for names, ignoring
3871 // special names (constructors, overloaded operators, selectors,
3873 IdentifierInfo *Name = ND->getIdentifier();
3877 // Only consider visible declarations and declarations from modules with
3878 // names that exactly match.
3879 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo &&
3880 !findAcceptableDecl(SemaRef, ND))
3883 FoundName(Name->getName());
3886 void TypoCorrectionConsumer::FoundName(StringRef Name) {
3887 // Compute the edit distance between the typo and the name of this
3888 // entity, and add the identifier to the list of results.
3889 addName(Name, nullptr);
3892 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) {
3893 // Compute the edit distance between the typo and this keyword,
3894 // and add the keyword to the list of results.
3895 addName(Keyword, nullptr, nullptr, true);
3898 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
3899 NestedNameSpecifier *NNS, bool isKeyword) {
3900 // Use a simple length-based heuristic to determine the minimum possible
3901 // edit distance. If the minimum isn't good enough, bail out early.
3902 StringRef TypoStr = Typo->getName();
3903 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
3904 if (MinED && TypoStr.size() / MinED < 3)
3907 // Compute an upper bound on the allowable edit distance, so that the
3908 // edit-distance algorithm can short-circuit.
3909 unsigned UpperBound = (TypoStr.size() + 2) / 3 + 1;
3910 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
3911 if (ED >= UpperBound) return;
3913 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
3914 if (isKeyword) TC.makeKeyword();
3915 TC.setCorrectionRange(nullptr, Result.getLookupNameInfo());
3919 static const unsigned MaxTypoDistanceResultSets = 5;
3921 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) {
3922 StringRef TypoStr = Typo->getName();
3923 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
3925 // For very short typos, ignore potential corrections that have a different
3926 // base identifier from the typo or which have a normalized edit distance
3927 // longer than the typo itself.
3928 if (TypoStr.size() < 3 &&
3929 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
3932 // If the correction is resolved but is not viable, ignore it.
3933 if (Correction.isResolved()) {
3934 checkCorrectionVisibility(SemaRef, Correction);
3935 if (!Correction || !isCandidateViable(*CorrectionValidator, Correction))
3939 TypoResultList &CList =
3940 CorrectionResults[Correction.getEditDistance(false)][Name];
3942 if (!CList.empty() && !CList.back().isResolved())
3944 if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
3945 std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts());
3946 for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end();
3947 RI != RIEnd; ++RI) {
3948 // If the Correction refers to a decl already in the result list,
3949 // replace the existing result if the string representation of Correction
3950 // comes before the current result alphabetically, then stop as there is
3951 // nothing more to be done to add Correction to the candidate set.
3952 if (RI->getCorrectionDecl() == NewND) {
3953 if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts()))
3959 if (CList.empty() || Correction.isResolved())
3960 CList.push_back(Correction);
3962 while (CorrectionResults.size() > MaxTypoDistanceResultSets)
3963 CorrectionResults.erase(std::prev(CorrectionResults.end()));
3966 void TypoCorrectionConsumer::addNamespaces(
3967 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
3968 SearchNamespaces = true;
3970 for (auto KNPair : KnownNamespaces)
3971 Namespaces.addNameSpecifier(KNPair.first);
3973 bool SSIsTemplate = false;
3974 if (NestedNameSpecifier *NNS =
3975 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) {
3976 if (const Type *T = NNS->getAsType())
3977 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization;
3979 // Do not transform this into an iterator-based loop. The loop body can
3980 // trigger the creation of further types (through lazy deserialization) and
3981 // invalide iterators into this list.
3982 auto &Types = SemaRef.getASTContext().getTypes();
3983 for (unsigned I = 0; I != Types.size(); ++I) {
3984 const auto *TI = Types[I];
3985 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
3986 CD = CD->getCanonicalDecl();
3987 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
3988 !CD->isUnion() && CD->getIdentifier() &&
3989 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
3990 (CD->isBeingDefined() || CD->isCompleteDefinition()))
3991 Namespaces.addNameSpecifier(CD);
3996 const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() {
3997 if (++CurrentTCIndex < ValidatedCorrections.size())
3998 return ValidatedCorrections[CurrentTCIndex];
4000 CurrentTCIndex = ValidatedCorrections.size();
4001 while (!CorrectionResults.empty()) {
4002 auto DI = CorrectionResults.begin();
4003 if (DI->second.empty()) {
4004 CorrectionResults.erase(DI);
4008 auto RI = DI->second.begin();
4009 if (RI->second.empty()) {
4010 DI->second.erase(RI);
4011 performQualifiedLookups();
4015 TypoCorrection TC = RI->second.pop_back_val();
4016 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) {
4017 ValidatedCorrections.push_back(TC);
4018 return ValidatedCorrections[CurrentTCIndex];
4021 return ValidatedCorrections[0]; // The empty correction.
4024 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
4025 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
4026 DeclContext *TempMemberContext = MemberContext;
4027 CXXScopeSpec *TempSS = SS.get();
4029 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
4031 CorrectionValidator->IsObjCIvarLookup,
4032 Name == Typo && !Candidate.WillReplaceSpecifier());
4033 switch (Result.getResultKind()) {
4034 case LookupResult::NotFound:
4035 case LookupResult::NotFoundInCurrentInstantiation:
4036 case LookupResult::FoundUnresolvedValue:
4038 // Immediately retry the lookup without the given CXXScopeSpec
4040 Candidate.WillReplaceSpecifier(true);
4043 if (TempMemberContext) {
4046 TempMemberContext = nullptr;
4049 if (SearchNamespaces)
4050 QualifiedResults.push_back(Candidate);
4053 case LookupResult::Ambiguous:
4054 // We don't deal with ambiguities.
4057 case LookupResult::Found:
4058 case LookupResult::FoundOverloaded:
4059 // Store all of the Decls for overloaded symbols
4060 for (auto *TRD : Result)
4061 Candidate.addCorrectionDecl(TRD);
4062 checkCorrectionVisibility(SemaRef, Candidate);
4063 if (!isCandidateViable(*CorrectionValidator, Candidate)) {
4064 if (SearchNamespaces)
4065 QualifiedResults.push_back(Candidate);
4068 Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4074 void TypoCorrectionConsumer::performQualifiedLookups() {
4075 unsigned TypoLen = Typo->getName().size();
4076 for (const TypoCorrection &QR : QualifiedResults) {
4077 for (const auto &NSI : Namespaces) {
4078 DeclContext *Ctx = NSI.DeclCtx;
4079 const Type *NSType = NSI.NameSpecifier->getAsType();
4081 // If the current NestedNameSpecifier refers to a class and the
4082 // current correction candidate is the name of that class, then skip
4083 // it as it is unlikely a qualified version of the class' constructor
4084 // is an appropriate correction.
4085 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() :
4087 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
4091 TypoCorrection TC(QR);
4092 TC.ClearCorrectionDecls();
4093 TC.setCorrectionSpecifier(NSI.NameSpecifier);
4094 TC.setQualifierDistance(NSI.EditDistance);
4095 TC.setCallbackDistance(0); // Reset the callback distance
4097 // If the current correction candidate and namespace combination are
4098 // too far away from the original typo based on the normalized edit
4099 // distance, then skip performing a qualified name lookup.
4100 unsigned TmpED = TC.getEditDistance(true);
4101 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4102 TypoLen / TmpED < 3)
4106 Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4107 if (!SemaRef.LookupQualifiedName(Result, Ctx))
4110 // Any corrections added below will be validated in subsequent
4111 // iterations of the main while() loop over the Consumer's contents.
4112 switch (Result.getResultKind()) {
4113 case LookupResult::Found:
4114 case LookupResult::FoundOverloaded: {
4115 if (SS && SS->isValid()) {
4116 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
4117 std::string OldQualified;
4118 llvm::raw_string_ostream OldOStream(OldQualified);
4119 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy());
4120 OldOStream << Typo->getName();
4121 // If correction candidate would be an identical written qualified
4122 // identifer, then the existing CXXScopeSpec probably included a
4123 // typedef that didn't get accounted for properly.
4124 if (OldOStream.str() == NewQualified)
4127 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4128 TRD != TRDEnd; ++TRD) {
4129 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
4130 NSType ? NSType->getAsCXXRecordDecl()
4132 TRD.getPair()) == Sema::AR_accessible)
4133 TC.addCorrectionDecl(*TRD);
4135 if (TC.isResolved()) {
4136 TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4141 case LookupResult::NotFound:
4142 case LookupResult::NotFoundInCurrentInstantiation:
4143 case LookupResult::Ambiguous:
4144 case LookupResult::FoundUnresolvedValue:
4149 QualifiedResults.clear();
4152 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4153 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4154 : Context(Context), CurContextChain(buildContextChain(CurContext)) {
4155 if (NestedNameSpecifier *NNS =
4156 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) {
4157 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4158 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4160 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
4162 // Build the list of identifiers that would be used for an absolute
4163 // (from the global context) NestedNameSpecifier referring to the current
4165 for (DeclContext *C : llvm::reverse(CurContextChain)) {
4166 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C))
4167 CurContextIdentifiers.push_back(ND->getIdentifier());
4170 // Add the global context as a NestedNameSpecifier
4171 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
4172 NestedNameSpecifier::GlobalSpecifier(Context), 1};
4173 DistanceMap[1].push_back(SI);
4176 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
4177 DeclContext *Start) -> DeclContextList {
4178 assert(Start && "Building a context chain from a null context");
4179 DeclContextList Chain;
4180 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
4181 DC = DC->getLookupParent()) {
4182 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
4183 if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
4184 !(ND && ND->isAnonymousNamespace()))
4185 Chain.push_back(DC->getPrimaryContext());
4191 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
4192 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) {
4193 unsigned NumSpecifiers = 0;
4194 for (DeclContext *C : llvm::reverse(DeclChain)) {
4195 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) {
4196 NNS = NestedNameSpecifier::Create(Context, NNS, ND);
4198 } else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) {
4199 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(),
4200 RD->getTypeForDecl());
4204 return NumSpecifiers;
4207 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
4209 NestedNameSpecifier *NNS = nullptr;
4210 unsigned NumSpecifiers = 0;
4211 DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
4212 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
4214 // Eliminate common elements from the two DeclContext chains.
4215 for (DeclContext *C : llvm::reverse(CurContextChain)) {
4216 if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C)
4218 NamespaceDeclChain.pop_back();
4221 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
4222 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
4224 // Add an explicit leading '::' specifier if needed.
4225 if (NamespaceDeclChain.empty()) {
4226 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4227 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4229 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4230 } else if (NamedDecl *ND =
4231 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
4232 IdentifierInfo *Name = ND->getIdentifier();
4233 bool SameNameSpecifier = false;
4234 if (std::find(CurNameSpecifierIdentifiers.begin(),
4235 CurNameSpecifierIdentifiers.end(),
4236 Name) != CurNameSpecifierIdentifiers.end()) {
4237 std::string NewNameSpecifier;
4238 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
4239 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
4240 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4241 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4242 SpecifierOStream.flush();
4243 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
4245 if (SameNameSpecifier ||
4246 std::find(CurContextIdentifiers.begin(), CurContextIdentifiers.end(),
4247 Name) != CurContextIdentifiers.end()) {
4248 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4249 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4251 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4255 // If the built NestedNameSpecifier would be replacing an existing
4256 // NestedNameSpecifier, use the number of component identifiers that
4257 // would need to be changed as the edit distance instead of the number
4258 // of components in the built NestedNameSpecifier.
4259 if (NNS && !CurNameSpecifierIdentifiers.empty()) {
4260 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
4261 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4262 NumSpecifiers = llvm::ComputeEditDistance(
4263 llvm::makeArrayRef(CurNameSpecifierIdentifiers),
4264 llvm::makeArrayRef(NewNameSpecifierIdentifiers));
4267 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
4268 DistanceMap[NumSpecifiers].push_back(SI);
4271 /// \brief Perform name lookup for a possible result for typo correction.
4272 static void LookupPotentialTypoResult(Sema &SemaRef,
4274 IdentifierInfo *Name,
4275 Scope *S, CXXScopeSpec *SS,
4276 DeclContext *MemberContext,
4277 bool EnteringContext,
4278 bool isObjCIvarLookup,
4280 Res.suppressDiagnostics();
4282 Res.setLookupName(Name);
4283 Res.setAllowHidden(FindHidden);
4284 if (MemberContext) {
4285 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
4286 if (isObjCIvarLookup) {
4287 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
4294 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(
4295 Name, ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
4302 SemaRef.LookupQualifiedName(Res, MemberContext);
4306 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
4309 // Fake ivar lookup; this should really be part of
4310 // LookupParsedName.
4311 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
4312 if (Method->isInstanceMethod() && Method->getClassInterface() &&
4314 (Res.isSingleResult() &&
4315 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) {
4316 if (ObjCIvarDecl *IV
4317 = Method->getClassInterface()->lookupInstanceVariable(Name)) {
4325 /// \brief Add keywords to the consumer as possible typo corrections.
4326 static void AddKeywordsToConsumer(Sema &SemaRef,
4327 TypoCorrectionConsumer &Consumer,
4328 Scope *S, CorrectionCandidateCallback &CCC,
4329 bool AfterNestedNameSpecifier) {
4330 if (AfterNestedNameSpecifier) {
4331 // For 'X::', we know exactly which keywords can appear next.
4332 Consumer.addKeywordResult("template");
4333 if (CCC.WantExpressionKeywords)
4334 Consumer.addKeywordResult("operator");
4338 if (CCC.WantObjCSuper)
4339 Consumer.addKeywordResult("super");
4341 if (CCC.WantTypeSpecifiers) {
4342 // Add type-specifier keywords to the set of results.
4343 static const char *const CTypeSpecs[] = {
4344 "char", "const", "double", "enum", "float", "int", "long", "short",
4345 "signed", "struct", "union", "unsigned", "void", "volatile",
4346 "_Complex", "_Imaginary",
4347 // storage-specifiers as well
4348 "extern", "inline", "static", "typedef"
4351 const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs);
4352 for (unsigned I = 0; I != NumCTypeSpecs; ++I)
4353 Consumer.addKeywordResult(CTypeSpecs[I]);
4355 if (SemaRef.getLangOpts().C99)
4356 Consumer.addKeywordResult("restrict");
4357 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
4358 Consumer.addKeywordResult("bool");
4359 else if (SemaRef.getLangOpts().C99)
4360 Consumer.addKeywordResult("_Bool");
4362 if (SemaRef.getLangOpts().CPlusPlus) {
4363 Consumer.addKeywordResult("class");
4364 Consumer.addKeywordResult("typename");
4365 Consumer.addKeywordResult("wchar_t");
4367 if (SemaRef.getLangOpts().CPlusPlus11) {
4368 Consumer.addKeywordResult("char16_t");
4369 Consumer.addKeywordResult("char32_t");
4370 Consumer.addKeywordResult("constexpr");
4371 Consumer.addKeywordResult("decltype");
4372 Consumer.addKeywordResult("thread_local");
4376 if (SemaRef.getLangOpts().GNUMode)
4377 Consumer.addKeywordResult("typeof");
4378 } else if (CCC.WantFunctionLikeCasts) {
4379 static const char *const CastableTypeSpecs[] = {
4380 "char", "double", "float", "int", "long", "short",
4381 "signed", "unsigned", "void"
4383 for (auto *kw : CastableTypeSpecs)
4384 Consumer.addKeywordResult(kw);
4387 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
4388 Consumer.addKeywordResult("const_cast");
4389 Consumer.addKeywordResult("dynamic_cast");
4390 Consumer.addKeywordResult("reinterpret_cast");
4391 Consumer.addKeywordResult("static_cast");
4394 if (CCC.WantExpressionKeywords) {
4395 Consumer.addKeywordResult("sizeof");
4396 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
4397 Consumer.addKeywordResult("false");
4398 Consumer.addKeywordResult("true");
4401 if (SemaRef.getLangOpts().CPlusPlus) {
4402 static const char *const CXXExprs[] = {
4403 "delete", "new", "operator", "throw", "typeid"
4405 const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs);
4406 for (unsigned I = 0; I != NumCXXExprs; ++I)
4407 Consumer.addKeywordResult(CXXExprs[I]);
4409 if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
4410 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
4411 Consumer.addKeywordResult("this");
4413 if (SemaRef.getLangOpts().CPlusPlus11) {
4414 Consumer.addKeywordResult("alignof");
4415 Consumer.addKeywordResult("nullptr");
4419 if (SemaRef.getLangOpts().C11) {
4420 // FIXME: We should not suggest _Alignof if the alignof macro
4422 Consumer.addKeywordResult("_Alignof");
4426 if (CCC.WantRemainingKeywords) {
4427 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
4429 static const char *const CStmts[] = {
4430 "do", "else", "for", "goto", "if", "return", "switch", "while" };
4431 const unsigned NumCStmts = llvm::array_lengthof(CStmts);
4432 for (unsigned I = 0; I != NumCStmts; ++I)
4433 Consumer.addKeywordResult(CStmts[I]);
4435 if (SemaRef.getLangOpts().CPlusPlus) {
4436 Consumer.addKeywordResult("catch");
4437 Consumer.addKeywordResult("try");
4440 if (S && S->getBreakParent())
4441 Consumer.addKeywordResult("break");
4443 if (S && S->getContinueParent())
4444 Consumer.addKeywordResult("continue");
4446 if (!SemaRef.getCurFunction()->SwitchStack.empty()) {
4447 Consumer.addKeywordResult("case");
4448 Consumer.addKeywordResult("default");
4451 if (SemaRef.getLangOpts().CPlusPlus) {
4452 Consumer.addKeywordResult("namespace");
4453 Consumer.addKeywordResult("template");
4456 if (S && S->isClassScope()) {
4457 Consumer.addKeywordResult("explicit");
4458 Consumer.addKeywordResult("friend");
4459 Consumer.addKeywordResult("mutable");
4460 Consumer.addKeywordResult("private");
4461 Consumer.addKeywordResult("protected");
4462 Consumer.addKeywordResult("public");
4463 Consumer.addKeywordResult("virtual");
4467 if (SemaRef.getLangOpts().CPlusPlus) {
4468 Consumer.addKeywordResult("using");
4470 if (SemaRef.getLangOpts().CPlusPlus11)
4471 Consumer.addKeywordResult("static_assert");
4476 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
4477 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4478 Scope *S, CXXScopeSpec *SS,
4479 std::unique_ptr<CorrectionCandidateCallback> CCC,
4480 DeclContext *MemberContext, bool EnteringContext,
4481 const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
4483 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
4484 DisableTypoCorrection)
4487 // In Microsoft mode, don't perform typo correction in a template member
4488 // function dependent context because it interferes with the "lookup into
4489 // dependent bases of class templates" feature.
4490 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
4491 isa<CXXMethodDecl>(CurContext))
4494 // We only attempt to correct typos for identifiers.
4495 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4499 // If the scope specifier itself was invalid, don't try to correct
4501 if (SS && SS->isInvalid())
4504 // Never try to correct typos during any kind of code synthesis.
4505 if (!CodeSynthesisContexts.empty())
4508 // Don't try to correct 'super'.
4509 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
4512 // Abort if typo correction already failed for this specific typo.
4513 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
4514 if (locs != TypoCorrectionFailures.end() &&
4515 locs->second.count(TypoName.getLoc()))
4518 // Don't try to correct the identifier "vector" when in AltiVec mode.
4519 // TODO: Figure out why typo correction misbehaves in this case, fix it, and
4520 // remove this workaround.
4521 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector"))
4524 // Provide a stop gap for files that are just seriously broken. Trying
4525 // to correct all typos can turn into a HUGE performance penalty, causing
4526 // some files to take minutes to get rejected by the parser.
4527 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
4528 if (Limit && TyposCorrected >= Limit)
4532 // If we're handling a missing symbol error, using modules, and the
4533 // special search all modules option is used, look for a missing import.
4534 if (ErrorRecovery && getLangOpts().Modules &&
4535 getLangOpts().ModulesSearchAll) {
4536 // The following has the side effect of loading the missing module.
4537 getModuleLoader().lookupMissingImports(Typo->getName(),
4538 TypoName.getLocStart());
4541 CorrectionCandidateCallback &CCCRef = *CCC;
4542 auto Consumer = llvm::make_unique<TypoCorrectionConsumer>(
4543 *this, TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4546 // Perform name lookup to find visible, similarly-named entities.
4547 bool IsUnqualifiedLookup = false;
4548 DeclContext *QualifiedDC = MemberContext;
4549 if (MemberContext) {
4550 LookupVisibleDecls(MemberContext, LookupKind, *Consumer);
4552 // Look in qualified interfaces.
4554 for (auto *I : OPT->quals())
4555 LookupVisibleDecls(I, LookupKind, *Consumer);
4557 } else if (SS && SS->isSet()) {
4558 QualifiedDC = computeDeclContext(*SS, EnteringContext);
4562 LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer);
4564 IsUnqualifiedLookup = true;
4567 // Determine whether we are going to search in the various namespaces for
4569 bool SearchNamespaces
4570 = getLangOpts().CPlusPlus &&
4571 (IsUnqualifiedLookup || (SS && SS->isSet()));
4573 if (IsUnqualifiedLookup || SearchNamespaces) {
4574 // For unqualified lookup, look through all of the names that we have
4575 // seen in this translation unit.
4576 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4577 for (const auto &I : Context.Idents)
4578 Consumer->FoundName(I.getKey());
4580 // Walk through identifiers in external identifier sources.
4581 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4582 if (IdentifierInfoLookup *External
4583 = Context.Idents.getExternalIdentifierLookup()) {
4584 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4586 StringRef Name = Iter->Next();
4590 Consumer->FoundName(Name);
4595 AddKeywordsToConsumer(*this, *Consumer, S, CCCRef, SS && SS->isNotEmpty());
4597 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
4598 // to search those namespaces.
4599 if (SearchNamespaces) {
4600 // Load any externally-known namespaces.
4601 if (ExternalSource && !LoadedExternalKnownNamespaces) {
4602 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
4603 LoadedExternalKnownNamespaces = true;
4604 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
4605 for (auto *N : ExternalKnownNamespaces)
4606 KnownNamespaces[N] = true;
4609 Consumer->addNamespaces(KnownNamespaces);
4615 /// \brief Try to "correct" a typo in the source code by finding
4616 /// visible declarations whose names are similar to the name that was
4617 /// present in the source code.
4619 /// \param TypoName the \c DeclarationNameInfo structure that contains
4620 /// the name that was present in the source code along with its location.
4622 /// \param LookupKind the name-lookup criteria used to search for the name.
4624 /// \param S the scope in which name lookup occurs.
4626 /// \param SS the nested-name-specifier that precedes the name we're
4627 /// looking for, if present.
4629 /// \param CCC A CorrectionCandidateCallback object that provides further
4630 /// validation of typo correction candidates. It also provides flags for
4631 /// determining the set of keywords permitted.
4633 /// \param MemberContext if non-NULL, the context in which to look for
4634 /// a member access expression.
4636 /// \param EnteringContext whether we're entering the context described by
4637 /// the nested-name-specifier SS.
4639 /// \param OPT when non-NULL, the search for visible declarations will
4640 /// also walk the protocols in the qualified interfaces of \p OPT.
4642 /// \returns a \c TypoCorrection containing the corrected name if the typo
4643 /// along with information such as the \c NamedDecl where the corrected name
4644 /// was declared, and any additional \c NestedNameSpecifier needed to access
4645 /// it (C++ only). The \c TypoCorrection is empty if there is no correction.
4646 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
4647 Sema::LookupNameKind LookupKind,
4648 Scope *S, CXXScopeSpec *SS,
4649 std::unique_ptr<CorrectionCandidateCallback> CCC,
4650 CorrectTypoKind Mode,
4651 DeclContext *MemberContext,
4652 bool EnteringContext,
4653 const ObjCObjectPointerType *OPT,
4654 bool RecordFailure) {
4655 assert(CCC && "CorrectTypo requires a CorrectionCandidateCallback");
4657 // Always let the ExternalSource have the first chance at correction, even
4658 // if we would otherwise have given up.
4659 if (ExternalSource) {
4660 if (TypoCorrection Correction = ExternalSource->CorrectTypo(
4661 TypoName, LookupKind, S, SS, *CCC, MemberContext, EnteringContext, OPT))
4665 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
4666 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
4667 // some instances of CTC_Unknown, while WantRemainingKeywords is true
4668 // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
4669 bool ObjCMessageReceiver = CCC->WantObjCSuper && !CCC->WantRemainingKeywords;
4671 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4672 auto Consumer = makeTypoCorrectionConsumer(
4673 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4674 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4677 return TypoCorrection();
4679 // If we haven't found anything, we're done.
4680 if (Consumer->empty())
4681 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4683 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4684 // is not more that about a third of the length of the typo's identifier.
4685 unsigned ED = Consumer->getBestEditDistance(true);
4686 unsigned TypoLen = Typo->getName().size();
4687 if (ED > 0 && TypoLen / ED < 3)
4688 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4690 TypoCorrection BestTC = Consumer->getNextCorrection();
4691 TypoCorrection SecondBestTC = Consumer->getNextCorrection();
4693 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4695 ED = BestTC.getEditDistance();
4697 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
4698 // If this was an unqualified lookup and we believe the callback
4699 // object wouldn't have filtered out possible corrections, note
4700 // that no correction was found.
4701 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4704 // If only a single name remains, return that result.
4705 if (!SecondBestTC ||
4706 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
4707 const TypoCorrection &Result = BestTC;
4709 // Don't correct to a keyword that's the same as the typo; the keyword
4710 // wasn't actually in scope.
4711 if (ED == 0 && Result.isKeyword())
4712 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4714 TypoCorrection TC = Result;
4715 TC.setCorrectionRange(SS, TypoName);
4716 checkCorrectionVisibility(*this, TC);
4718 } else if (SecondBestTC && ObjCMessageReceiver) {
4719 // Prefer 'super' when we're completing in a message-receiver
4722 if (BestTC.getCorrection().getAsString() != "super") {
4723 if (SecondBestTC.getCorrection().getAsString() == "super")
4724 BestTC = SecondBestTC;
4725 else if ((*Consumer)["super"].front().isKeyword())
4726 BestTC = (*Consumer)["super"].front();
4728 // Don't correct to a keyword that's the same as the typo; the keyword
4729 // wasn't actually in scope.
4730 if (BestTC.getEditDistance() == 0 ||
4731 BestTC.getCorrection().getAsString() != "super")
4732 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4734 BestTC.setCorrectionRange(SS, TypoName);
4738 // Record the failure's location if needed and return an empty correction. If
4739 // this was an unqualified lookup and we believe the callback object did not
4740 // filter out possible corrections, also cache the failure for the typo.
4741 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC);
4744 /// \brief Try to "correct" a typo in the source code by finding
4745 /// visible declarations whose names are similar to the name that was
4746 /// present in the source code.
4748 /// \param TypoName the \c DeclarationNameInfo structure that contains
4749 /// the name that was present in the source code along with its location.
4751 /// \param LookupKind the name-lookup criteria used to search for the name.
4753 /// \param S the scope in which name lookup occurs.
4755 /// \param SS the nested-name-specifier that precedes the name we're
4756 /// looking for, if present.
4758 /// \param CCC A CorrectionCandidateCallback object that provides further
4759 /// validation of typo correction candidates. It also provides flags for
4760 /// determining the set of keywords permitted.
4762 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print
4763 /// diagnostics when the actual typo correction is attempted.
4765 /// \param TRC A TypoRecoveryCallback functor that will be used to build an
4766 /// Expr from a typo correction candidate.
4768 /// \param MemberContext if non-NULL, the context in which to look for
4769 /// a member access expression.
4771 /// \param EnteringContext whether we're entering the context described by
4772 /// the nested-name-specifier SS.
4774 /// \param OPT when non-NULL, the search for visible declarations will
4775 /// also walk the protocols in the qualified interfaces of \p OPT.
4777 /// \returns a new \c TypoExpr that will later be replaced in the AST with an
4778 /// Expr representing the result of performing typo correction, or nullptr if
4779 /// typo correction is not possible. If nullptr is returned, no diagnostics will
4780 /// be emitted and it is the responsibility of the caller to emit any that are
4782 TypoExpr *Sema::CorrectTypoDelayed(
4783 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4784 Scope *S, CXXScopeSpec *SS,
4785 std::unique_ptr<CorrectionCandidateCallback> CCC,
4786 TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode,
4787 DeclContext *MemberContext, bool EnteringContext,
4788 const ObjCObjectPointerType *OPT) {
4789 assert(CCC && "CorrectTypoDelayed requires a CorrectionCandidateCallback");
4791 auto Consumer = makeTypoCorrectionConsumer(
4792 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4793 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4795 // Give the external sema source a chance to correct the typo.
4796 TypoCorrection ExternalTypo;
4797 if (ExternalSource && Consumer) {
4798 ExternalTypo = ExternalSource->CorrectTypo(
4799 TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(),
4800 MemberContext, EnteringContext, OPT);
4802 Consumer->addCorrection(ExternalTypo);
4805 if (!Consumer || Consumer->empty())
4808 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4809 // is not more that about a third of the length of the typo's identifier.
4810 unsigned ED = Consumer->getBestEditDistance(true);
4811 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4812 if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3)
4815 ExprEvalContexts.back().NumTypos++;
4816 return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC));
4819 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) {
4823 CorrectionDecls.clear();
4825 CorrectionDecls.push_back(CDecl);
4827 if (!CorrectionName)
4828 CorrectionName = CDecl->getDeclName();
4831 std::string TypoCorrection::getAsString(const LangOptions &LO) const {
4832 if (CorrectionNameSpec) {
4833 std::string tmpBuffer;
4834 llvm::raw_string_ostream PrefixOStream(tmpBuffer);
4835 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO));
4836 PrefixOStream << CorrectionName;
4837 return PrefixOStream.str();
4840 return CorrectionName.getAsString();
4843 bool CorrectionCandidateCallback::ValidateCandidate(
4844 const TypoCorrection &candidate) {
4845 if (!candidate.isResolved())
4848 if (candidate.isKeyword())
4849 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
4850 WantRemainingKeywords || WantObjCSuper;
4852 bool HasNonType = false;
4853 bool HasStaticMethod = false;
4854 bool HasNonStaticMethod = false;
4855 for (Decl *D : candidate) {
4856 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
4857 D = FTD->getTemplatedDecl();
4858 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
4859 if (Method->isStatic())
4860 HasStaticMethod = true;
4862 HasNonStaticMethod = true;
4864 if (!isa<TypeDecl>(D))
4868 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
4869 !candidate.getCorrectionSpecifier())
4872 return WantTypeSpecifiers || HasNonType;
4875 FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs,
4876 bool HasExplicitTemplateArgs,
4878 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
4879 CurContext(SemaRef.CurContext), MemberFn(ME) {
4880 WantTypeSpecifiers = false;
4881 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && NumArgs == 1;
4882 WantRemainingKeywords = false;
4885 bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) {
4886 if (!candidate.getCorrectionDecl())
4887 return candidate.isKeyword();
4889 for (auto *C : candidate) {
4890 FunctionDecl *FD = nullptr;
4891 NamedDecl *ND = C->getUnderlyingDecl();
4892 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
4893 FD = FTD->getTemplatedDecl();
4894 if (!HasExplicitTemplateArgs && !FD) {
4895 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
4896 // If the Decl is neither a function nor a template function,
4897 // determine if it is a pointer or reference to a function. If so,
4898 // check against the number of arguments expected for the pointee.
4899 QualType ValType = cast<ValueDecl>(ND)->getType();
4900 if (ValType->isAnyPointerType() || ValType->isReferenceType())
4901 ValType = ValType->getPointeeType();
4902 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
4903 if (FPT->getNumParams() == NumArgs)
4908 // Skip the current candidate if it is not a FunctionDecl or does not accept
4909 // the current number of arguments.
4910 if (!FD || !(FD->getNumParams() >= NumArgs &&
4911 FD->getMinRequiredArguments() <= NumArgs))
4914 // If the current candidate is a non-static C++ method, skip the candidate
4915 // unless the method being corrected--or the current DeclContext, if the
4916 // function being corrected is not a method--is a method in the same class
4917 // or a descendent class of the candidate's parent class.
4918 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
4919 if (MemberFn || !MD->isStatic()) {
4920 CXXMethodDecl *CurMD =
4922 ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl())
4923 : dyn_cast_or_null<CXXMethodDecl>(CurContext);
4924 CXXRecordDecl *CurRD =
4925 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
4926 CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
4927 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
4936 void Sema::diagnoseTypo(const TypoCorrection &Correction,
4937 const PartialDiagnostic &TypoDiag,
4938 bool ErrorRecovery) {
4939 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
4943 /// Find which declaration we should import to provide the definition of
4944 /// the given declaration.
4945 static NamedDecl *getDefinitionToImport(NamedDecl *D) {
4946 if (VarDecl *VD = dyn_cast<VarDecl>(D))
4947 return VD->getDefinition();
4948 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
4949 return FD->getDefinition();
4950 if (TagDecl *TD = dyn_cast<TagDecl>(D))
4951 return TD->getDefinition();
4952 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
4953 return ID->getDefinition();
4954 if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
4955 return PD->getDefinition();
4956 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
4957 return getDefinitionToImport(TD->getTemplatedDecl());
4961 void Sema::diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl,
4962 MissingImportKind MIK, bool Recover) {
4963 assert(!isVisible(Decl) && "missing import for non-hidden decl?");
4965 // Suggest importing a module providing the definition of this entity, if
4967 NamedDecl *Def = getDefinitionToImport(Decl);
4971 Module *Owner = getOwningModule(Decl);
4972 assert(Owner && "definition of hidden declaration is not in a module");
4974 llvm::SmallVector<Module*, 8> OwningModules;
4975 OwningModules.push_back(Owner);
4976 auto Merged = Context.getModulesWithMergedDefinition(Decl);
4977 OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end());
4979 diagnoseMissingImport(Loc, Decl, Decl->getLocation(), OwningModules, MIK,
4983 /// \brief Get a "quoted.h" or <angled.h> include path to use in a diagnostic
4984 /// suggesting the addition of a #include of the specified file.
4985 static std::string getIncludeStringForHeader(Preprocessor &PP,
4986 const FileEntry *E) {
4989 PP.getHeaderSearchInfo().suggestPathToFileForDiagnostics(E, &IsSystem);
4990 return (IsSystem ? '<' : '"') + Path + (IsSystem ? '>' : '"');
4993 void Sema::diagnoseMissingImport(SourceLocation UseLoc, NamedDecl *Decl,
4994 SourceLocation DeclLoc,
4995 ArrayRef<Module *> Modules,
4996 MissingImportKind MIK, bool Recover) {
4997 assert(!Modules.empty());
4999 if (Modules.size() > 1) {
5000 std::string ModuleList;
5002 for (Module *M : Modules) {
5003 ModuleList += "\n ";
5004 if (++N == 5 && N != Modules.size()) {
5005 ModuleList += "[...]";
5008 ModuleList += M->getFullModuleName();
5011 Diag(UseLoc, diag::err_module_unimported_use_multiple)
5012 << (int)MIK << Decl << ModuleList;
5013 } else if (const FileEntry *E =
5014 PP.getModuleHeaderToIncludeForDiagnostics(UseLoc, DeclLoc)) {
5015 // The right way to make the declaration visible is to include a header;
5016 // suggest doing so.
5018 // FIXME: Find a smart place to suggest inserting a #include, and add
5019 // a FixItHint there.
5020 Diag(UseLoc, diag::err_module_unimported_use_header)
5021 << (int)MIK << Decl << Modules[0]->getFullModuleName()
5022 << getIncludeStringForHeader(PP, E);
5024 // FIXME: Add a FixItHint that imports the corresponding module.
5025 Diag(UseLoc, diag::err_module_unimported_use)
5026 << (int)MIK << Decl << Modules[0]->getFullModuleName();
5031 case MissingImportKind::Declaration:
5032 DiagID = diag::note_previous_declaration;
5034 case MissingImportKind::Definition:
5035 DiagID = diag::note_previous_definition;
5037 case MissingImportKind::DefaultArgument:
5038 DiagID = diag::note_default_argument_declared_here;
5040 case MissingImportKind::ExplicitSpecialization:
5041 DiagID = diag::note_explicit_specialization_declared_here;
5043 case MissingImportKind::PartialSpecialization:
5044 DiagID = diag::note_partial_specialization_declared_here;
5047 Diag(DeclLoc, DiagID);
5049 // Try to recover by implicitly importing this module.
5051 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5054 /// \brief Diagnose a successfully-corrected typo. Separated from the correction
5055 /// itself to allow external validation of the result, etc.
5057 /// \param Correction The result of performing typo correction.
5058 /// \param TypoDiag The diagnostic to produce. This will have the corrected
5059 /// string added to it (and usually also a fixit).
5060 /// \param PrevNote A note to use when indicating the location of the entity to
5061 /// which we are correcting. Will have the correction string added to it.
5062 /// \param ErrorRecovery If \c true (the default), the caller is going to
5063 /// recover from the typo as if the corrected string had been typed.
5064 /// In this case, \c PDiag must be an error, and we will attach a fixit
5066 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5067 const PartialDiagnostic &TypoDiag,
5068 const PartialDiagnostic &PrevNote,
5069 bool ErrorRecovery) {
5070 std::string CorrectedStr = Correction.getAsString(getLangOpts());
5071 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
5072 FixItHint FixTypo = FixItHint::CreateReplacement(
5073 Correction.getCorrectionRange(), CorrectedStr);
5075 // Maybe we're just missing a module import.
5076 if (Correction.requiresImport()) {
5077 NamedDecl *Decl = Correction.getFoundDecl();
5078 assert(Decl && "import required but no declaration to import");
5080 diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl,
5081 MissingImportKind::Declaration, ErrorRecovery);
5085 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
5086 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
5088 NamedDecl *ChosenDecl =
5089 Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
5090 if (PrevNote.getDiagID() && ChosenDecl)
5091 Diag(ChosenDecl->getLocation(), PrevNote)
5092 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
5094 // Add any extra diagnostics.
5095 for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
5096 Diag(Correction.getCorrectionRange().getBegin(), PD);
5099 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
5100 TypoDiagnosticGenerator TDG,
5101 TypoRecoveryCallback TRC) {
5102 assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer");
5103 auto TE = new (Context) TypoExpr(Context.DependentTy);
5104 auto &State = DelayedTypos[TE];
5105 State.Consumer = std::move(TCC);
5106 State.DiagHandler = std::move(TDG);
5107 State.RecoveryHandler = std::move(TRC);
5111 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const {
5112 auto Entry = DelayedTypos.find(TE);
5113 assert(Entry != DelayedTypos.end() &&
5114 "Failed to get the state for a TypoExpr!");
5115 return Entry->second;
5118 void Sema::clearDelayedTypo(TypoExpr *TE) {
5119 DelayedTypos.erase(TE);
5122 void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) {
5123 DeclarationNameInfo Name(II, IILoc);
5124 LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration);
5125 R.suppressDiagnostics();
5126 R.setHideTags(false);