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 void Sema::makeMergedDefinitionVisible(NamedDecl *ND) {
1330 if (auto *M = getCurrentModule())
1331 Context.mergeDefinitionIntoModule(ND, M);
1333 // We're not building a module; just make the definition visible.
1334 ND->setHidden(false);
1336 // If ND is a template declaration, make the template parameters
1337 // visible too. They're not (necessarily) within a mergeable DeclContext.
1338 if (auto *TD = dyn_cast<TemplateDecl>(ND))
1339 for (auto *Param : *TD->getTemplateParameters())
1340 makeMergedDefinitionVisible(Param);
1343 /// \brief Find the module in which the given declaration was defined.
1344 static Module *getDefiningModule(Sema &S, Decl *Entity) {
1345 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
1346 // If this function was instantiated from a template, the defining module is
1347 // the module containing the pattern.
1348 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1350 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
1351 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1353 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
1354 if (auto *Pattern = ED->getTemplateInstantiationPattern())
1356 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
1357 if (VarDecl *Pattern = VD->getTemplateInstantiationPattern())
1361 // Walk up to the containing context. That might also have been instantiated
1363 DeclContext *Context = Entity->getDeclContext();
1364 if (Context->isFileContext())
1365 return S.getOwningModule(Entity);
1366 return getDefiningModule(S, cast<Decl>(Context));
1369 llvm::DenseSet<Module*> &Sema::getLookupModules() {
1370 unsigned N = CodeSynthesisContexts.size();
1371 for (unsigned I = CodeSynthesisContextLookupModules.size();
1373 Module *M = getDefiningModule(*this, CodeSynthesisContexts[I].Entity);
1374 if (M && !LookupModulesCache.insert(M).second)
1376 CodeSynthesisContextLookupModules.push_back(M);
1378 return LookupModulesCache;
1381 bool Sema::hasVisibleMergedDefinition(NamedDecl *Def) {
1382 for (Module *Merged : Context.getModulesWithMergedDefinition(Def))
1383 if (isModuleVisible(Merged))
1388 template<typename ParmDecl>
1390 hasVisibleDefaultArgument(Sema &S, const ParmDecl *D,
1391 llvm::SmallVectorImpl<Module *> *Modules) {
1392 if (!D->hasDefaultArgument())
1396 auto &DefaultArg = D->getDefaultArgStorage();
1397 if (!DefaultArg.isInherited() && S.isVisible(D))
1400 if (!DefaultArg.isInherited() && Modules) {
1401 auto *NonConstD = const_cast<ParmDecl*>(D);
1402 Modules->push_back(S.getOwningModule(NonConstD));
1403 const auto &Merged = S.Context.getModulesWithMergedDefinition(NonConstD);
1404 Modules->insert(Modules->end(), Merged.begin(), Merged.end());
1407 // If there was a previous default argument, maybe its parameter is visible.
1408 D = DefaultArg.getInheritedFrom();
1413 bool Sema::hasVisibleDefaultArgument(const NamedDecl *D,
1414 llvm::SmallVectorImpl<Module *> *Modules) {
1415 if (auto *P = dyn_cast<TemplateTypeParmDecl>(D))
1416 return ::hasVisibleDefaultArgument(*this, P, Modules);
1417 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D))
1418 return ::hasVisibleDefaultArgument(*this, P, Modules);
1419 return ::hasVisibleDefaultArgument(*this, cast<TemplateTemplateParmDecl>(D),
1423 template<typename Filter>
1424 static bool hasVisibleDeclarationImpl(Sema &S, const NamedDecl *D,
1425 llvm::SmallVectorImpl<Module *> *Modules,
1427 for (auto *Redecl : D->redecls()) {
1428 auto *R = cast<NamedDecl>(Redecl);
1436 Modules->push_back(R->getOwningModule());
1437 const auto &Merged = S.Context.getModulesWithMergedDefinition(R);
1438 Modules->insert(Modules->end(), Merged.begin(), Merged.end());
1445 bool Sema::hasVisibleExplicitSpecialization(
1446 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1447 return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1448 if (auto *RD = dyn_cast<CXXRecordDecl>(D))
1449 return RD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1450 if (auto *FD = dyn_cast<FunctionDecl>(D))
1451 return FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1452 if (auto *VD = dyn_cast<VarDecl>(D))
1453 return VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1454 llvm_unreachable("unknown explicit specialization kind");
1458 bool Sema::hasVisibleMemberSpecialization(
1459 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1460 assert(isa<CXXRecordDecl>(D->getDeclContext()) &&
1461 "not a member specialization");
1462 return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1463 // If the specialization is declared at namespace scope, then it's a member
1464 // specialization declaration. If it's lexically inside the class
1465 // definition then it was instantiated.
1467 // FIXME: This is a hack. There should be a better way to determine this.
1468 // FIXME: What about MS-style explicit specializations declared within a
1469 // class definition?
1470 return D->getLexicalDeclContext()->isFileContext();
1476 /// \brief Determine whether a declaration is visible to name lookup.
1478 /// This routine determines whether the declaration D is visible in the current
1479 /// lookup context, taking into account the current template instantiation
1480 /// stack. During template instantiation, a declaration is visible if it is
1481 /// visible from a module containing any entity on the template instantiation
1482 /// path (by instantiating a template, you allow it to see the declarations that
1483 /// your module can see, including those later on in your module).
1484 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
1485 assert(D->isHidden() && "should not call this: not in slow case");
1487 Module *DeclModule = SemaRef.getOwningModule(D);
1488 assert(DeclModule && "hidden decl not from a module");
1490 // If the owning module is visible, and the decl is not module private,
1491 // then the decl is visible too. (Module private is ignored within the same
1492 // top-level module.)
1493 // FIXME: Check the owning module for module-private declarations rather than
1494 // assuming "same AST file" is the same thing as "same module".
1495 if ((!D->isFromASTFile() || !D->isModulePrivate()) &&
1496 (SemaRef.isModuleVisible(DeclModule) ||
1497 SemaRef.hasVisibleMergedDefinition(D)))
1500 // If this declaration is not at namespace scope nor module-private,
1501 // then it is visible if its lexical parent has a visible definition.
1502 DeclContext *DC = D->getLexicalDeclContext();
1503 if (!D->isModulePrivate() && DC && !DC->isFileContext() &&
1504 !isa<LinkageSpecDecl>(DC) && !isa<ExportDecl>(DC)) {
1505 // For a parameter, check whether our current template declaration's
1506 // lexical context is visible, not whether there's some other visible
1507 // definition of it, because parameters aren't "within" the definition.
1509 // In C++ we need to check for a visible definition due to ODR merging,
1510 // and in C we must not because each declaration of a function gets its own
1511 // set of declarations for tags in prototype scope.
1512 if ((D->isTemplateParameter() || isa<ParmVarDecl>(D)
1513 || (isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus))
1514 ? isVisible(SemaRef, cast<NamedDecl>(DC))
1515 : SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC))) {
1516 if (SemaRef.CodeSynthesisContexts.empty() &&
1517 // FIXME: Do something better in this case.
1518 !SemaRef.getLangOpts().ModulesLocalVisibility) {
1519 // Cache the fact that this declaration is implicitly visible because
1520 // its parent has a visible definition.
1521 D->setHidden(false);
1528 // Find the extra places where we need to look.
1529 llvm::DenseSet<Module*> &LookupModules = SemaRef.getLookupModules();
1530 if (LookupModules.empty())
1534 DeclModule = SemaRef.getOwningModule(D);
1535 assert(DeclModule && "hidden decl not from a module");
1538 // If our lookup set contains the decl's module, it's visible.
1539 if (LookupModules.count(DeclModule))
1542 // If the declaration isn't exported, it's not visible in any other module.
1543 if (D->isModulePrivate())
1546 // Check whether DeclModule is transitively exported to an import of
1548 return std::any_of(LookupModules.begin(), LookupModules.end(),
1549 [&](Module *M) { return M->isModuleVisible(DeclModule); });
1552 bool Sema::isVisibleSlow(const NamedDecl *D) {
1553 return LookupResult::isVisible(*this, const_cast<NamedDecl*>(D));
1556 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
1561 return New->isExternallyVisible();
1564 /// \brief Retrieve the visible declaration corresponding to D, if any.
1566 /// This routine determines whether the declaration D is visible in the current
1567 /// module, with the current imports. If not, it checks whether any
1568 /// redeclaration of D is visible, and if so, returns that declaration.
1570 /// \returns D, or a visible previous declaration of D, whichever is more recent
1571 /// and visible. If no declaration of D is visible, returns null.
1572 static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D) {
1573 assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case");
1575 for (auto RD : D->redecls()) {
1576 // Don't bother with extra checks if we already know this one isn't visible.
1580 auto ND = cast<NamedDecl>(RD);
1581 // FIXME: This is wrong in the case where the previous declaration is not
1582 // visible in the same scope as D. This needs to be done much more
1584 if (LookupResult::isVisible(SemaRef, ND))
1591 bool Sema::hasVisibleDeclarationSlow(const NamedDecl *D,
1592 llvm::SmallVectorImpl<Module *> *Modules) {
1593 assert(!isVisible(D) && "not in slow case");
1594 return hasVisibleDeclarationImpl(*this, D, Modules,
1595 [](const NamedDecl *) { return true; });
1598 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
1599 if (auto *ND = dyn_cast<NamespaceDecl>(D)) {
1600 // Namespaces are a bit of a special case: we expect there to be a lot of
1601 // redeclarations of some namespaces, all declarations of a namespace are
1602 // essentially interchangeable, all declarations are found by name lookup
1603 // if any is, and namespaces are never looked up during template
1604 // instantiation. So we benefit from caching the check in this case, and
1605 // it is correct to do so.
1606 auto *Key = ND->getCanonicalDecl();
1607 if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key))
1610 isVisible(getSema(), Key) ? Key : findAcceptableDecl(getSema(), Key);
1612 getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable));
1616 return findAcceptableDecl(getSema(), D);
1619 /// @brief Perform unqualified name lookup starting from a given
1622 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
1623 /// used to find names within the current scope. For example, 'x' in
1627 /// return x; // unqualified name look finds 'x' in the global scope
1631 /// Different lookup criteria can find different names. For example, a
1632 /// particular scope can have both a struct and a function of the same
1633 /// name, and each can be found by certain lookup criteria. For more
1634 /// information about lookup criteria, see the documentation for the
1635 /// class LookupCriteria.
1637 /// @param S The scope from which unqualified name lookup will
1638 /// begin. If the lookup criteria permits, name lookup may also search
1639 /// in the parent scopes.
1641 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to
1642 /// look up and the lookup kind), and is updated with the results of lookup
1643 /// including zero or more declarations and possibly additional information
1644 /// used to diagnose ambiguities.
1646 /// @returns \c true if lookup succeeded and false otherwise.
1647 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
1648 DeclarationName Name = R.getLookupName();
1649 if (!Name) return false;
1651 LookupNameKind NameKind = R.getLookupKind();
1653 if (!getLangOpts().CPlusPlus) {
1654 // Unqualified name lookup in C/Objective-C is purely lexical, so
1655 // search in the declarations attached to the name.
1656 if (NameKind == Sema::LookupRedeclarationWithLinkage) {
1657 // Find the nearest non-transparent declaration scope.
1658 while (!(S->getFlags() & Scope::DeclScope) ||
1659 (S->getEntity() && S->getEntity()->isTransparentContext()))
1663 // When performing a scope lookup, we want to find local extern decls.
1664 FindLocalExternScope FindLocals(R);
1666 // Scan up the scope chain looking for a decl that matches this
1667 // identifier that is in the appropriate namespace. This search
1668 // should not take long, as shadowing of names is uncommon, and
1669 // deep shadowing is extremely uncommon.
1670 bool LeftStartingScope = false;
1672 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
1673 IEnd = IdResolver.end();
1675 if (NamedDecl *D = R.getAcceptableDecl(*I)) {
1676 if (NameKind == LookupRedeclarationWithLinkage) {
1677 // Determine whether this (or a previous) declaration is
1679 if (!LeftStartingScope && !S->isDeclScope(*I))
1680 LeftStartingScope = true;
1682 // If we found something outside of our starting scope that
1683 // does not have linkage, skip it.
1684 if (LeftStartingScope && !((*I)->hasLinkage())) {
1689 else if (NameKind == LookupObjCImplicitSelfParam &&
1690 !isa<ImplicitParamDecl>(*I))
1695 // Check whether there are any other declarations with the same name
1696 // and in the same scope.
1698 // Find the scope in which this declaration was declared (if it
1699 // actually exists in a Scope).
1700 while (S && !S->isDeclScope(D))
1703 // If the scope containing the declaration is the translation unit,
1704 // then we'll need to perform our checks based on the matching
1705 // DeclContexts rather than matching scopes.
1706 if (S && isNamespaceOrTranslationUnitScope(S))
1709 // Compute the DeclContext, if we need it.
1710 DeclContext *DC = nullptr;
1712 DC = (*I)->getDeclContext()->getRedeclContext();
1714 IdentifierResolver::iterator LastI = I;
1715 for (++LastI; LastI != IEnd; ++LastI) {
1717 // Match based on scope.
1718 if (!S->isDeclScope(*LastI))
1721 // Match based on DeclContext.
1723 = (*LastI)->getDeclContext()->getRedeclContext();
1724 if (!LastDC->Equals(DC))
1728 // If the declaration is in the right namespace and visible, add it.
1729 if (NamedDecl *LastD = R.getAcceptableDecl(*LastI))
1739 // Perform C++ unqualified name lookup.
1740 if (CppLookupName(R, S))
1744 // If we didn't find a use of this identifier, and if the identifier
1745 // corresponds to a compiler builtin, create the decl object for the builtin
1746 // now, injecting it into translation unit scope, and return it.
1747 if (AllowBuiltinCreation && LookupBuiltin(*this, R))
1750 // If we didn't find a use of this identifier, the ExternalSource
1751 // may be able to handle the situation.
1752 // Note: some lookup failures are expected!
1753 // See e.g. R.isForRedeclaration().
1754 return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
1757 /// @brief Perform qualified name lookup in the namespaces nominated by
1758 /// using directives by the given context.
1760 /// C++98 [namespace.qual]p2:
1761 /// Given X::m (where X is a user-declared namespace), or given \::m
1762 /// (where X is the global namespace), let S be the set of all
1763 /// declarations of m in X and in the transitive closure of all
1764 /// namespaces nominated by using-directives in X and its used
1765 /// namespaces, except that using-directives are ignored in any
1766 /// namespace, including X, directly containing one or more
1767 /// declarations of m. No namespace is searched more than once in
1768 /// the lookup of a name. If S is the empty set, the program is
1769 /// ill-formed. Otherwise, if S has exactly one member, or if the
1770 /// context of the reference is a using-declaration
1771 /// (namespace.udecl), S is the required set of declarations of
1772 /// m. Otherwise if the use of m is not one that allows a unique
1773 /// declaration to be chosen from S, the program is ill-formed.
1775 /// C++98 [namespace.qual]p5:
1776 /// During the lookup of a qualified namespace member name, if the
1777 /// lookup finds more than one declaration of the member, and if one
1778 /// declaration introduces a class name or enumeration name and the
1779 /// other declarations either introduce the same object, the same
1780 /// enumerator or a set of functions, the non-type name hides the
1781 /// class or enumeration name if and only if the declarations are
1782 /// from the same namespace; otherwise (the declarations are from
1783 /// different namespaces), the program is ill-formed.
1784 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
1785 DeclContext *StartDC) {
1786 assert(StartDC->isFileContext() && "start context is not a file context");
1788 DeclContext::udir_range UsingDirectives = StartDC->using_directives();
1789 if (UsingDirectives.begin() == UsingDirectives.end()) return false;
1791 // We have at least added all these contexts to the queue.
1792 llvm::SmallPtrSet<DeclContext*, 8> Visited;
1793 Visited.insert(StartDC);
1795 // We have not yet looked into these namespaces, much less added
1796 // their "using-children" to the queue.
1797 SmallVector<NamespaceDecl*, 8> Queue;
1799 // We have already looked into the initial namespace; seed the queue
1800 // with its using-children.
1801 for (auto *I : UsingDirectives) {
1802 NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace();
1803 if (Visited.insert(ND).second)
1804 Queue.push_back(ND);
1807 // The easiest way to implement the restriction in [namespace.qual]p5
1808 // is to check whether any of the individual results found a tag
1809 // and, if so, to declare an ambiguity if the final result is not
1811 bool FoundTag = false;
1812 bool FoundNonTag = false;
1814 LookupResult LocalR(LookupResult::Temporary, R);
1817 while (!Queue.empty()) {
1818 NamespaceDecl *ND = Queue.pop_back_val();
1820 // We go through some convolutions here to avoid copying results
1821 // between LookupResults.
1822 bool UseLocal = !R.empty();
1823 LookupResult &DirectR = UseLocal ? LocalR : R;
1824 bool FoundDirect = LookupDirect(S, DirectR, ND);
1827 // First do any local hiding.
1828 DirectR.resolveKind();
1830 // If the local result is a tag, remember that.
1831 if (DirectR.isSingleTagDecl())
1836 // Append the local results to the total results if necessary.
1838 R.addAllDecls(LocalR);
1843 // If we find names in this namespace, ignore its using directives.
1849 for (auto I : ND->using_directives()) {
1850 NamespaceDecl *Nom = I->getNominatedNamespace();
1851 if (Visited.insert(Nom).second)
1852 Queue.push_back(Nom);
1857 if (FoundTag && FoundNonTag)
1858 R.setAmbiguousQualifiedTagHiding();
1866 /// \brief Callback that looks for any member of a class with the given name.
1867 static bool LookupAnyMember(const CXXBaseSpecifier *Specifier,
1868 CXXBasePath &Path, DeclarationName Name) {
1869 RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
1871 Path.Decls = BaseRecord->lookup(Name);
1872 return !Path.Decls.empty();
1875 /// \brief Determine whether the given set of member declarations contains only
1876 /// static members, nested types, and enumerators.
1877 template<typename InputIterator>
1878 static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) {
1879 Decl *D = (*First)->getUnderlyingDecl();
1880 if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D))
1883 if (isa<CXXMethodDecl>(D)) {
1884 // Determine whether all of the methods are static.
1885 bool AllMethodsAreStatic = true;
1886 for(; First != Last; ++First) {
1887 D = (*First)->getUnderlyingDecl();
1889 if (!isa<CXXMethodDecl>(D)) {
1890 assert(isa<TagDecl>(D) && "Non-function must be a tag decl");
1894 if (!cast<CXXMethodDecl>(D)->isStatic()) {
1895 AllMethodsAreStatic = false;
1900 if (AllMethodsAreStatic)
1907 /// \brief Perform qualified name lookup into a given context.
1909 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
1910 /// names when the context of those names is explicit specified, e.g.,
1911 /// "std::vector" or "x->member", or as part of unqualified name lookup.
1913 /// Different lookup criteria can find different names. For example, a
1914 /// particular scope can have both a struct and a function of the same
1915 /// name, and each can be found by certain lookup criteria. For more
1916 /// information about lookup criteria, see the documentation for the
1917 /// class LookupCriteria.
1919 /// \param R captures both the lookup criteria and any lookup results found.
1921 /// \param LookupCtx The context in which qualified name lookup will
1922 /// search. If the lookup criteria permits, name lookup may also search
1923 /// in the parent contexts or (for C++ classes) base classes.
1925 /// \param InUnqualifiedLookup true if this is qualified name lookup that
1926 /// occurs as part of unqualified name lookup.
1928 /// \returns true if lookup succeeded, false if it failed.
1929 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
1930 bool InUnqualifiedLookup) {
1931 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
1933 if (!R.getLookupName())
1936 // Make sure that the declaration context is complete.
1937 assert((!isa<TagDecl>(LookupCtx) ||
1938 LookupCtx->isDependentContext() ||
1939 cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
1940 cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
1941 "Declaration context must already be complete!");
1943 struct QualifiedLookupInScope {
1945 DeclContext *Context;
1946 // Set flag in DeclContext informing debugger that we're looking for qualified name
1947 QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) {
1948 oldVal = ctx->setUseQualifiedLookup();
1950 ~QualifiedLookupInScope() {
1951 Context->setUseQualifiedLookup(oldVal);
1955 if (LookupDirect(*this, R, LookupCtx)) {
1957 if (isa<CXXRecordDecl>(LookupCtx))
1958 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
1962 // Don't descend into implied contexts for redeclarations.
1963 // C++98 [namespace.qual]p6:
1964 // In a declaration for a namespace member in which the
1965 // declarator-id is a qualified-id, given that the qualified-id
1966 // for the namespace member has the form
1967 // nested-name-specifier unqualified-id
1968 // the unqualified-id shall name a member of the namespace
1969 // designated by the nested-name-specifier.
1970 // See also [class.mfct]p5 and [class.static.data]p2.
1971 if (R.isForRedeclaration())
1974 // If this is a namespace, look it up in the implied namespaces.
1975 if (LookupCtx->isFileContext())
1976 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
1978 // If this isn't a C++ class, we aren't allowed to look into base
1979 // classes, we're done.
1980 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
1981 if (!LookupRec || !LookupRec->getDefinition())
1984 // If we're performing qualified name lookup into a dependent class,
1985 // then we are actually looking into a current instantiation. If we have any
1986 // dependent base classes, then we either have to delay lookup until
1987 // template instantiation time (at which point all bases will be available)
1988 // or we have to fail.
1989 if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
1990 LookupRec->hasAnyDependentBases()) {
1991 R.setNotFoundInCurrentInstantiation();
1995 // Perform lookup into our base classes.
1997 Paths.setOrigin(LookupRec);
1999 // Look for this member in our base classes
2000 bool (*BaseCallback)(const CXXBaseSpecifier *Specifier, CXXBasePath &Path,
2001 DeclarationName Name) = nullptr;
2002 switch (R.getLookupKind()) {
2003 case LookupObjCImplicitSelfParam:
2004 case LookupOrdinaryName:
2005 case LookupMemberName:
2006 case LookupRedeclarationWithLinkage:
2007 case LookupLocalFriendName:
2008 BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
2012 BaseCallback = &CXXRecordDecl::FindTagMember;
2016 BaseCallback = &LookupAnyMember;
2019 case LookupOMPReductionName:
2020 BaseCallback = &CXXRecordDecl::FindOMPReductionMember;
2023 case LookupUsingDeclName:
2024 // This lookup is for redeclarations only.
2026 case LookupOperatorName:
2027 case LookupNamespaceName:
2028 case LookupObjCProtocolName:
2030 // These lookups will never find a member in a C++ class (or base class).
2033 case LookupNestedNameSpecifierName:
2034 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember;
2038 DeclarationName Name = R.getLookupName();
2039 if (!LookupRec->lookupInBases(
2040 [=](const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
2041 return BaseCallback(Specifier, Path, Name);
2046 R.setNamingClass(LookupRec);
2048 // C++ [class.member.lookup]p2:
2049 // [...] If the resulting set of declarations are not all from
2050 // sub-objects of the same type, or the set has a nonstatic member
2051 // and includes members from distinct sub-objects, there is an
2052 // ambiguity and the program is ill-formed. Otherwise that set is
2053 // the result of the lookup.
2054 QualType SubobjectType;
2055 int SubobjectNumber = 0;
2056 AccessSpecifier SubobjectAccess = AS_none;
2058 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
2059 Path != PathEnd; ++Path) {
2060 const CXXBasePathElement &PathElement = Path->back();
2062 // Pick the best (i.e. most permissive i.e. numerically lowest) access
2063 // across all paths.
2064 SubobjectAccess = std::min(SubobjectAccess, Path->Access);
2066 // Determine whether we're looking at a distinct sub-object or not.
2067 if (SubobjectType.isNull()) {
2068 // This is the first subobject we've looked at. Record its type.
2069 SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
2070 SubobjectNumber = PathElement.SubobjectNumber;
2075 != Context.getCanonicalType(PathElement.Base->getType())) {
2076 // We found members of the given name in two subobjects of
2077 // different types. If the declaration sets aren't the same, this
2078 // lookup is ambiguous.
2079 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) {
2080 CXXBasePaths::paths_iterator FirstPath = Paths.begin();
2081 DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin();
2082 DeclContext::lookup_iterator CurrentD = Path->Decls.begin();
2084 while (FirstD != FirstPath->Decls.end() &&
2085 CurrentD != Path->Decls.end()) {
2086 if ((*FirstD)->getUnderlyingDecl()->getCanonicalDecl() !=
2087 (*CurrentD)->getUnderlyingDecl()->getCanonicalDecl())
2094 if (FirstD == FirstPath->Decls.end() &&
2095 CurrentD == Path->Decls.end())
2099 R.setAmbiguousBaseSubobjectTypes(Paths);
2103 if (SubobjectNumber != PathElement.SubobjectNumber) {
2104 // We have a different subobject of the same type.
2106 // C++ [class.member.lookup]p5:
2107 // A static member, a nested type or an enumerator defined in
2108 // a base class T can unambiguously be found even if an object
2109 // has more than one base class subobject of type T.
2110 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end()))
2113 // We have found a nonstatic member name in multiple, distinct
2114 // subobjects. Name lookup is ambiguous.
2115 R.setAmbiguousBaseSubobjects(Paths);
2120 // Lookup in a base class succeeded; return these results.
2122 for (auto *D : Paths.front().Decls) {
2123 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
2131 /// \brief Performs qualified name lookup or special type of lookup for
2132 /// "__super::" scope specifier.
2134 /// This routine is a convenience overload meant to be called from contexts
2135 /// that need to perform a qualified name lookup with an optional C++ scope
2136 /// specifier that might require special kind of lookup.
2138 /// \param R captures both the lookup criteria and any lookup results found.
2140 /// \param LookupCtx The context in which qualified name lookup will
2143 /// \param SS An optional C++ scope-specifier.
2145 /// \returns true if lookup succeeded, false if it failed.
2146 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2148 auto *NNS = SS.getScopeRep();
2149 if (NNS && NNS->getKind() == NestedNameSpecifier::Super)
2150 return LookupInSuper(R, NNS->getAsRecordDecl());
2153 return LookupQualifiedName(R, LookupCtx);
2156 /// @brief Performs name lookup for a name that was parsed in the
2157 /// source code, and may contain a C++ scope specifier.
2159 /// This routine is a convenience routine meant to be called from
2160 /// contexts that receive a name and an optional C++ scope specifier
2161 /// (e.g., "N::M::x"). It will then perform either qualified or
2162 /// unqualified name lookup (with LookupQualifiedName or LookupName,
2163 /// respectively) on the given name and return those results. It will
2164 /// perform a special type of lookup for "__super::" scope specifier.
2166 /// @param S The scope from which unqualified name lookup will
2169 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
2171 /// @param EnteringContext Indicates whether we are going to enter the
2172 /// context of the scope-specifier SS (if present).
2174 /// @returns True if any decls were found (but possibly ambiguous)
2175 bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
2176 bool AllowBuiltinCreation, bool EnteringContext) {
2177 if (SS && SS->isInvalid()) {
2178 // When the scope specifier is invalid, don't even look for
2183 if (SS && SS->isSet()) {
2184 NestedNameSpecifier *NNS = SS->getScopeRep();
2185 if (NNS->getKind() == NestedNameSpecifier::Super)
2186 return LookupInSuper(R, NNS->getAsRecordDecl());
2188 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
2189 // We have resolved the scope specifier to a particular declaration
2190 // contex, and will perform name lookup in that context.
2191 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
2194 R.setContextRange(SS->getRange());
2195 return LookupQualifiedName(R, DC);
2198 // We could not resolve the scope specified to a specific declaration
2199 // context, which means that SS refers to an unknown specialization.
2200 // Name lookup can't find anything in this case.
2201 R.setNotFoundInCurrentInstantiation();
2202 R.setContextRange(SS->getRange());
2206 // Perform unqualified name lookup starting in the given scope.
2207 return LookupName(R, S, AllowBuiltinCreation);
2210 /// \brief Perform qualified name lookup into all base classes of the given
2213 /// \param R captures both the lookup criteria and any lookup results found.
2215 /// \param Class The context in which qualified name lookup will
2216 /// search. Name lookup will search in all base classes merging the results.
2218 /// @returns True if any decls were found (but possibly ambiguous)
2219 bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) {
2220 // The access-control rules we use here are essentially the rules for
2221 // doing a lookup in Class that just magically skipped the direct
2222 // members of Class itself. That is, the naming class is Class, and the
2223 // access includes the access of the base.
2224 for (const auto &BaseSpec : Class->bases()) {
2225 CXXRecordDecl *RD = cast<CXXRecordDecl>(
2226 BaseSpec.getType()->castAs<RecordType>()->getDecl());
2227 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
2228 Result.setBaseObjectType(Context.getRecordType(Class));
2229 LookupQualifiedName(Result, RD);
2231 // Copy the lookup results into the target, merging the base's access into
2233 for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
2234 R.addDecl(I.getDecl(),
2235 CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(),
2239 Result.suppressDiagnostics();
2243 R.setNamingClass(Class);
2248 /// \brief Produce a diagnostic describing the ambiguity that resulted
2249 /// from name lookup.
2251 /// \param Result The result of the ambiguous lookup to be diagnosed.
2252 void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
2253 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
2255 DeclarationName Name = Result.getLookupName();
2256 SourceLocation NameLoc = Result.getNameLoc();
2257 SourceRange LookupRange = Result.getContextRange();
2259 switch (Result.getAmbiguityKind()) {
2260 case LookupResult::AmbiguousBaseSubobjects: {
2261 CXXBasePaths *Paths = Result.getBasePaths();
2262 QualType SubobjectType = Paths->front().back().Base->getType();
2263 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
2264 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
2267 DeclContext::lookup_iterator Found = Paths->front().Decls.begin();
2268 while (isa<CXXMethodDecl>(*Found) &&
2269 cast<CXXMethodDecl>(*Found)->isStatic())
2272 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
2276 case LookupResult::AmbiguousBaseSubobjectTypes: {
2277 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
2278 << Name << LookupRange;
2280 CXXBasePaths *Paths = Result.getBasePaths();
2281 std::set<Decl *> DeclsPrinted;
2282 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
2283 PathEnd = Paths->end();
2284 Path != PathEnd; ++Path) {
2285 Decl *D = Path->Decls.front();
2286 if (DeclsPrinted.insert(D).second)
2287 Diag(D->getLocation(), diag::note_ambiguous_member_found);
2292 case LookupResult::AmbiguousTagHiding: {
2293 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
2295 llvm::SmallPtrSet<NamedDecl*, 8> TagDecls;
2297 for (auto *D : Result)
2298 if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
2299 TagDecls.insert(TD);
2300 Diag(TD->getLocation(), diag::note_hidden_tag);
2303 for (auto *D : Result)
2304 if (!isa<TagDecl>(D))
2305 Diag(D->getLocation(), diag::note_hiding_object);
2307 // For recovery purposes, go ahead and implement the hiding.
2308 LookupResult::Filter F = Result.makeFilter();
2309 while (F.hasNext()) {
2310 if (TagDecls.count(F.next()))
2317 case LookupResult::AmbiguousReference: {
2318 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
2320 for (auto *D : Result)
2321 Diag(D->getLocation(), diag::note_ambiguous_candidate) << D;
2328 struct AssociatedLookup {
2329 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
2330 Sema::AssociatedNamespaceSet &Namespaces,
2331 Sema::AssociatedClassSet &Classes)
2332 : S(S), Namespaces(Namespaces), Classes(Classes),
2333 InstantiationLoc(InstantiationLoc) {
2337 Sema::AssociatedNamespaceSet &Namespaces;
2338 Sema::AssociatedClassSet &Classes;
2339 SourceLocation InstantiationLoc;
2341 } // end anonymous namespace
2344 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
2346 static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces,
2348 // Add the associated namespace for this class.
2350 // We don't use DeclContext::getEnclosingNamespaceContext() as this may
2351 // be a locally scoped record.
2353 // We skip out of inline namespaces. The innermost non-inline namespace
2354 // contains all names of all its nested inline namespaces anyway, so we can
2355 // replace the entire inline namespace tree with its root.
2356 while (Ctx->isRecord() || Ctx->isTransparentContext() ||
2357 Ctx->isInlineNamespace())
2358 Ctx = Ctx->getParent();
2360 if (Ctx->isFileContext())
2361 Namespaces.insert(Ctx->getPrimaryContext());
2364 // \brief Add the associated classes and namespaces for argument-dependent
2365 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2).
2367 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2368 const TemplateArgument &Arg) {
2369 // C++ [basic.lookup.koenig]p2, last bullet:
2371 switch (Arg.getKind()) {
2372 case TemplateArgument::Null:
2375 case TemplateArgument::Type:
2376 // [...] the namespaces and classes associated with the types of the
2377 // template arguments provided for template type parameters (excluding
2378 // template template parameters)
2379 addAssociatedClassesAndNamespaces(Result, Arg.getAsType());
2382 case TemplateArgument::Template:
2383 case TemplateArgument::TemplateExpansion: {
2384 // [...] the namespaces in which any template template arguments are
2385 // defined; and the classes in which any member templates used as
2386 // template template arguments are defined.
2387 TemplateName Template = Arg.getAsTemplateOrTemplatePattern();
2388 if (ClassTemplateDecl *ClassTemplate
2389 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
2390 DeclContext *Ctx = ClassTemplate->getDeclContext();
2391 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2392 Result.Classes.insert(EnclosingClass);
2393 // Add the associated namespace for this class.
2394 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2399 case TemplateArgument::Declaration:
2400 case TemplateArgument::Integral:
2401 case TemplateArgument::Expression:
2402 case TemplateArgument::NullPtr:
2403 // [Note: non-type template arguments do not contribute to the set of
2404 // associated namespaces. ]
2407 case TemplateArgument::Pack:
2408 for (const auto &P : Arg.pack_elements())
2409 addAssociatedClassesAndNamespaces(Result, P);
2414 // \brief Add the associated classes and namespaces for
2415 // argument-dependent lookup with an argument of class type
2416 // (C++ [basic.lookup.koenig]p2).
2418 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2419 CXXRecordDecl *Class) {
2421 // Just silently ignore anything whose name is __va_list_tag.
2422 if (Class->getDeclName() == Result.S.VAListTagName)
2425 // C++ [basic.lookup.koenig]p2:
2427 // -- If T is a class type (including unions), its associated
2428 // classes are: the class itself; the class of which it is a
2429 // member, if any; and its direct and indirect base
2430 // classes. Its associated namespaces are the namespaces in
2431 // which its associated classes are defined.
2433 // Add the class of which it is a member, if any.
2434 DeclContext *Ctx = Class->getDeclContext();
2435 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2436 Result.Classes.insert(EnclosingClass);
2437 // Add the associated namespace for this class.
2438 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2440 // Add the class itself. If we've already seen this class, we don't
2441 // need to visit base classes.
2443 // FIXME: That's not correct, we may have added this class only because it
2444 // was the enclosing class of another class, and in that case we won't have
2445 // added its base classes yet.
2446 if (!Result.Classes.insert(Class))
2449 // -- If T is a template-id, its associated namespaces and classes are
2450 // the namespace in which the template is defined; for member
2451 // templates, the member template's class; the namespaces and classes
2452 // associated with the types of the template arguments provided for
2453 // template type parameters (excluding template template parameters); the
2454 // namespaces in which any template template arguments are defined; and
2455 // the classes in which any member templates used as template template
2456 // arguments are defined. [Note: non-type template arguments do not
2457 // contribute to the set of associated namespaces. ]
2458 if (ClassTemplateSpecializationDecl *Spec
2459 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
2460 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
2461 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2462 Result.Classes.insert(EnclosingClass);
2463 // Add the associated namespace for this class.
2464 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2466 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
2467 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2468 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]);
2471 // Only recurse into base classes for complete types.
2472 if (!Result.S.isCompleteType(Result.InstantiationLoc,
2473 Result.S.Context.getRecordType(Class)))
2476 // Add direct and indirect base classes along with their associated
2478 SmallVector<CXXRecordDecl *, 32> Bases;
2479 Bases.push_back(Class);
2480 while (!Bases.empty()) {
2481 // Pop this class off the stack.
2482 Class = Bases.pop_back_val();
2484 // Visit the base classes.
2485 for (const auto &Base : Class->bases()) {
2486 const RecordType *BaseType = Base.getType()->getAs<RecordType>();
2487 // In dependent contexts, we do ADL twice, and the first time around,
2488 // the base type might be a dependent TemplateSpecializationType, or a
2489 // TemplateTypeParmType. If that happens, simply ignore it.
2490 // FIXME: If we want to support export, we probably need to add the
2491 // namespace of the template in a TemplateSpecializationType, or even
2492 // the classes and namespaces of known non-dependent arguments.
2495 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
2496 if (Result.Classes.insert(BaseDecl)) {
2497 // Find the associated namespace for this base class.
2498 DeclContext *BaseCtx = BaseDecl->getDeclContext();
2499 CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
2501 // Make sure we visit the bases of this base class.
2502 if (BaseDecl->bases_begin() != BaseDecl->bases_end())
2503 Bases.push_back(BaseDecl);
2509 // \brief Add the associated classes and namespaces for
2510 // argument-dependent lookup with an argument of type T
2511 // (C++ [basic.lookup.koenig]p2).
2513 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
2514 // C++ [basic.lookup.koenig]p2:
2516 // For each argument type T in the function call, there is a set
2517 // of zero or more associated namespaces and a set of zero or more
2518 // associated classes to be considered. The sets of namespaces and
2519 // classes is determined entirely by the types of the function
2520 // arguments (and the namespace of any template template
2521 // argument). Typedef names and using-declarations used to specify
2522 // the types do not contribute to this set. The sets of namespaces
2523 // and classes are determined in the following way:
2525 SmallVector<const Type *, 16> Queue;
2526 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
2529 switch (T->getTypeClass()) {
2531 #define TYPE(Class, Base)
2532 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
2533 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
2534 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
2535 #define ABSTRACT_TYPE(Class, Base)
2536 #include "clang/AST/TypeNodes.def"
2537 // T is canonical. We can also ignore dependent types because
2538 // we don't need to do ADL at the definition point, but if we
2539 // wanted to implement template export (or if we find some other
2540 // use for associated classes and namespaces...) this would be
2544 // -- If T is a pointer to U or an array of U, its associated
2545 // namespaces and classes are those associated with U.
2547 T = cast<PointerType>(T)->getPointeeType().getTypePtr();
2549 case Type::ConstantArray:
2550 case Type::IncompleteArray:
2551 case Type::VariableArray:
2552 T = cast<ArrayType>(T)->getElementType().getTypePtr();
2555 // -- If T is a fundamental type, its associated sets of
2556 // namespaces and classes are both empty.
2560 // -- If T is a class type (including unions), its associated
2561 // classes are: the class itself; the class of which it is a
2562 // member, if any; and its direct and indirect base
2563 // classes. Its associated namespaces are the namespaces in
2564 // which its associated classes are defined.
2565 case Type::Record: {
2566 CXXRecordDecl *Class =
2567 cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl());
2568 addAssociatedClassesAndNamespaces(Result, Class);
2572 // -- If T is an enumeration type, its associated namespace is
2573 // the namespace in which it is defined. If it is class
2574 // member, its associated class is the member's class; else
2575 // it has no associated class.
2577 EnumDecl *Enum = cast<EnumType>(T)->getDecl();
2579 DeclContext *Ctx = Enum->getDeclContext();
2580 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2581 Result.Classes.insert(EnclosingClass);
2583 // Add the associated namespace for this class.
2584 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2589 // -- If T is a function type, its associated namespaces and
2590 // classes are those associated with the function parameter
2591 // types and those associated with the return type.
2592 case Type::FunctionProto: {
2593 const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
2594 for (const auto &Arg : Proto->param_types())
2595 Queue.push_back(Arg.getTypePtr());
2598 case Type::FunctionNoProto: {
2599 const FunctionType *FnType = cast<FunctionType>(T);
2600 T = FnType->getReturnType().getTypePtr();
2604 // -- If T is a pointer to a member function of a class X, its
2605 // associated namespaces and classes are those associated
2606 // with the function parameter types and return type,
2607 // together with those associated with X.
2609 // -- If T is a pointer to a data member of class X, its
2610 // associated namespaces and classes are those associated
2611 // with the member type together with those associated with
2613 case Type::MemberPointer: {
2614 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T);
2616 // Queue up the class type into which this points.
2617 Queue.push_back(MemberPtr->getClass());
2619 // And directly continue with the pointee type.
2620 T = MemberPtr->getPointeeType().getTypePtr();
2624 // As an extension, treat this like a normal pointer.
2625 case Type::BlockPointer:
2626 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr();
2629 // References aren't covered by the standard, but that's such an
2630 // obvious defect that we cover them anyway.
2631 case Type::LValueReference:
2632 case Type::RValueReference:
2633 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr();
2636 // These are fundamental types.
2638 case Type::ExtVector:
2642 // Non-deduced auto types only get here for error cases.
2644 case Type::DeducedTemplateSpecialization:
2647 // If T is an Objective-C object or interface type, or a pointer to an
2648 // object or interface type, the associated namespace is the global
2650 case Type::ObjCObject:
2651 case Type::ObjCInterface:
2652 case Type::ObjCObjectPointer:
2653 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
2656 // Atomic types are just wrappers; use the associations of the
2659 T = cast<AtomicType>(T)->getValueType().getTypePtr();
2662 T = cast<PipeType>(T)->getElementType().getTypePtr();
2668 T = Queue.pop_back_val();
2672 /// \brief Find the associated classes and namespaces for
2673 /// argument-dependent lookup for a call with the given set of
2676 /// This routine computes the sets of associated classes and associated
2677 /// namespaces searched by argument-dependent lookup
2678 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
2679 void Sema::FindAssociatedClassesAndNamespaces(
2680 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
2681 AssociatedNamespaceSet &AssociatedNamespaces,
2682 AssociatedClassSet &AssociatedClasses) {
2683 AssociatedNamespaces.clear();
2684 AssociatedClasses.clear();
2686 AssociatedLookup Result(*this, InstantiationLoc,
2687 AssociatedNamespaces, AssociatedClasses);
2689 // C++ [basic.lookup.koenig]p2:
2690 // For each argument type T in the function call, there is a set
2691 // of zero or more associated namespaces and a set of zero or more
2692 // associated classes to be considered. The sets of namespaces and
2693 // classes is determined entirely by the types of the function
2694 // arguments (and the namespace of any template template
2696 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
2697 Expr *Arg = Args[ArgIdx];
2699 if (Arg->getType() != Context.OverloadTy) {
2700 addAssociatedClassesAndNamespaces(Result, Arg->getType());
2704 // [...] In addition, if the argument is the name or address of a
2705 // set of overloaded functions and/or function templates, its
2706 // associated classes and namespaces are the union of those
2707 // associated with each of the members of the set: the namespace
2708 // in which the function or function template is defined and the
2709 // classes and namespaces associated with its (non-dependent)
2710 // parameter types and return type.
2711 Arg = Arg->IgnoreParens();
2712 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg))
2713 if (unaryOp->getOpcode() == UO_AddrOf)
2714 Arg = unaryOp->getSubExpr();
2716 UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg);
2719 for (const auto *D : ULE->decls()) {
2720 // Look through any using declarations to find the underlying function.
2721 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
2723 // Add the classes and namespaces associated with the parameter
2724 // types and return type of this function.
2725 addAssociatedClassesAndNamespaces(Result, FDecl->getType());
2730 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
2732 LookupNameKind NameKind,
2733 RedeclarationKind Redecl) {
2734 LookupResult R(*this, Name, Loc, NameKind, Redecl);
2736 return R.getAsSingle<NamedDecl>();
2739 /// \brief Find the protocol with the given name, if any.
2740 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II,
2741 SourceLocation IdLoc,
2742 RedeclarationKind Redecl) {
2743 Decl *D = LookupSingleName(TUScope, II, IdLoc,
2744 LookupObjCProtocolName, Redecl);
2745 return cast_or_null<ObjCProtocolDecl>(D);
2748 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
2749 QualType T1, QualType T2,
2750 UnresolvedSetImpl &Functions) {
2751 // C++ [over.match.oper]p3:
2752 // -- The set of non-member candidates is the result of the
2753 // unqualified lookup of operator@ in the context of the
2754 // expression according to the usual rules for name lookup in
2755 // unqualified function calls (3.4.2) except that all member
2756 // functions are ignored.
2757 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
2758 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
2759 LookupName(Operators, S);
2761 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
2762 Functions.append(Operators.begin(), Operators.end());
2765 Sema::SpecialMemberOverloadResult Sema::LookupSpecialMember(CXXRecordDecl *RD,
2766 CXXSpecialMember SM,
2771 bool VolatileThis) {
2772 assert(CanDeclareSpecialMemberFunction(RD) &&
2773 "doing special member lookup into record that isn't fully complete");
2774 RD = RD->getDefinition();
2775 if (RValueThis || ConstThis || VolatileThis)
2776 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) &&
2777 "constructors and destructors always have unqualified lvalue this");
2778 if (ConstArg || VolatileArg)
2779 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) &&
2780 "parameter-less special members can't have qualified arguments");
2782 // FIXME: Get the caller to pass in a location for the lookup.
2783 SourceLocation LookupLoc = RD->getLocation();
2785 llvm::FoldingSetNodeID ID;
2788 ID.AddInteger(ConstArg);
2789 ID.AddInteger(VolatileArg);
2790 ID.AddInteger(RValueThis);
2791 ID.AddInteger(ConstThis);
2792 ID.AddInteger(VolatileThis);
2795 SpecialMemberOverloadResultEntry *Result =
2796 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
2798 // This was already cached
2802 Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>();
2803 Result = new (Result) SpecialMemberOverloadResultEntry(ID);
2804 SpecialMemberCache.InsertNode(Result, InsertPoint);
2806 if (SM == CXXDestructor) {
2807 if (RD->needsImplicitDestructor())
2808 DeclareImplicitDestructor(RD);
2809 CXXDestructorDecl *DD = RD->getDestructor();
2810 assert(DD && "record without a destructor");
2811 Result->setMethod(DD);
2812 Result->setKind(DD->isDeleted() ?
2813 SpecialMemberOverloadResult::NoMemberOrDeleted :
2814 SpecialMemberOverloadResult::Success);
2818 // Prepare for overload resolution. Here we construct a synthetic argument
2819 // if necessary and make sure that implicit functions are declared.
2820 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD));
2821 DeclarationName Name;
2822 Expr *Arg = nullptr;
2825 QualType ArgType = CanTy;
2826 ExprValueKind VK = VK_LValue;
2828 if (SM == CXXDefaultConstructor) {
2829 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2831 if (RD->needsImplicitDefaultConstructor())
2832 DeclareImplicitDefaultConstructor(RD);
2834 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) {
2835 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2836 if (RD->needsImplicitCopyConstructor())
2837 DeclareImplicitCopyConstructor(RD);
2838 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor())
2839 DeclareImplicitMoveConstructor(RD);
2841 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
2842 if (RD->needsImplicitCopyAssignment())
2843 DeclareImplicitCopyAssignment(RD);
2844 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment())
2845 DeclareImplicitMoveAssignment(RD);
2851 ArgType.addVolatile();
2853 // This isn't /really/ specified by the standard, but it's implied
2854 // we should be working from an RValue in the case of move to ensure
2855 // that we prefer to bind to rvalue references, and an LValue in the
2856 // case of copy to ensure we don't bind to rvalue references.
2857 // Possibly an XValue is actually correct in the case of move, but
2858 // there is no semantic difference for class types in this restricted
2860 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment)
2866 OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK);
2868 if (SM != CXXDefaultConstructor) {
2873 // Create the object argument
2874 QualType ThisTy = CanTy;
2878 ThisTy.addVolatile();
2879 Expr::Classification Classification =
2880 OpaqueValueExpr(LookupLoc, ThisTy,
2881 RValueThis ? VK_RValue : VK_LValue).Classify(Context);
2883 // Now we perform lookup on the name we computed earlier and do overload
2884 // resolution. Lookup is only performed directly into the class since there
2885 // will always be a (possibly implicit) declaration to shadow any others.
2886 OverloadCandidateSet OCS(LookupLoc, OverloadCandidateSet::CSK_Normal);
2887 DeclContext::lookup_result R = RD->lookup(Name);
2890 // We might have no default constructor because we have a lambda's closure
2891 // type, rather than because there's some other declared constructor.
2892 // Every class has a copy/move constructor, copy/move assignment, and
2894 assert(SM == CXXDefaultConstructor &&
2895 "lookup for a constructor or assignment operator was empty");
2896 Result->setMethod(nullptr);
2897 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2901 // Copy the candidates as our processing of them may load new declarations
2902 // from an external source and invalidate lookup_result.
2903 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
2905 for (NamedDecl *CandDecl : Candidates) {
2906 if (CandDecl->isInvalidDecl())
2909 DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public);
2910 auto CtorInfo = getConstructorInfo(Cand);
2911 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl())) {
2912 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2913 AddMethodCandidate(M, Cand, RD, ThisTy, Classification,
2914 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2916 AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl,
2917 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2919 AddOverloadCandidate(M, Cand, llvm::makeArrayRef(&Arg, NumArgs), OCS,
2921 } else if (FunctionTemplateDecl *Tmpl =
2922 dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) {
2923 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2924 AddMethodTemplateCandidate(
2925 Tmpl, Cand, RD, nullptr, ThisTy, Classification,
2926 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2928 AddTemplateOverloadCandidate(
2929 CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr,
2930 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2932 AddTemplateOverloadCandidate(
2933 Tmpl, Cand, nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2935 assert(isa<UsingDecl>(Cand.getDecl()) &&
2936 "illegal Kind of operator = Decl");
2940 OverloadCandidateSet::iterator Best;
2941 switch (OCS.BestViableFunction(*this, LookupLoc, Best)) {
2943 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
2944 Result->setKind(SpecialMemberOverloadResult::Success);
2948 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
2949 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2953 Result->setMethod(nullptr);
2954 Result->setKind(SpecialMemberOverloadResult::Ambiguous);
2957 case OR_No_Viable_Function:
2958 Result->setMethod(nullptr);
2959 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2966 /// \brief Look up the default constructor for the given class.
2967 CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) {
2968 SpecialMemberOverloadResult Result =
2969 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false,
2972 return cast_or_null<CXXConstructorDecl>(Result.getMethod());
2975 /// \brief Look up the copying constructor for the given class.
2976 CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class,
2978 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
2979 "non-const, non-volatile qualifiers for copy ctor arg");
2980 SpecialMemberOverloadResult Result =
2981 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const,
2982 Quals & Qualifiers::Volatile, false, false, false);
2984 return cast_or_null<CXXConstructorDecl>(Result.getMethod());
2987 /// \brief Look up the moving constructor for the given class.
2988 CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class,
2990 SpecialMemberOverloadResult Result =
2991 LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const,
2992 Quals & Qualifiers::Volatile, false, false, false);
2994 return cast_or_null<CXXConstructorDecl>(Result.getMethod());
2997 /// \brief Look up the constructors for the given class.
2998 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) {
2999 // If the implicit constructors have not yet been declared, do so now.
3000 if (CanDeclareSpecialMemberFunction(Class)) {
3001 if (Class->needsImplicitDefaultConstructor())
3002 DeclareImplicitDefaultConstructor(Class);
3003 if (Class->needsImplicitCopyConstructor())
3004 DeclareImplicitCopyConstructor(Class);
3005 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
3006 DeclareImplicitMoveConstructor(Class);
3009 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class));
3010 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T);
3011 return Class->lookup(Name);
3014 /// \brief Look up the copying assignment operator for the given class.
3015 CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class,
3016 unsigned Quals, bool RValueThis,
3017 unsigned ThisQuals) {
3018 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3019 "non-const, non-volatile qualifiers for copy assignment arg");
3020 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3021 "non-const, non-volatile qualifiers for copy assignment this");
3022 SpecialMemberOverloadResult Result =
3023 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const,
3024 Quals & Qualifiers::Volatile, RValueThis,
3025 ThisQuals & Qualifiers::Const,
3026 ThisQuals & Qualifiers::Volatile);
3028 return Result.getMethod();
3031 /// \brief Look up the moving assignment operator for the given class.
3032 CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class,
3035 unsigned ThisQuals) {
3036 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3037 "non-const, non-volatile qualifiers for copy assignment this");
3038 SpecialMemberOverloadResult Result =
3039 LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const,
3040 Quals & Qualifiers::Volatile, RValueThis,
3041 ThisQuals & Qualifiers::Const,
3042 ThisQuals & Qualifiers::Volatile);
3044 return Result.getMethod();
3047 /// \brief Look for the destructor of the given class.
3049 /// During semantic analysis, this routine should be used in lieu of
3050 /// CXXRecordDecl::getDestructor().
3052 /// \returns The destructor for this class.
3053 CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) {
3054 return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor,
3055 false, false, false,
3056 false, false).getMethod());
3059 /// LookupLiteralOperator - Determine which literal operator should be used for
3060 /// a user-defined literal, per C++11 [lex.ext].
3062 /// Normal overload resolution is not used to select which literal operator to
3063 /// call for a user-defined literal. Look up the provided literal operator name,
3064 /// and filter the results to the appropriate set for the given argument types.
3065 Sema::LiteralOperatorLookupResult
3066 Sema::LookupLiteralOperator(Scope *S, LookupResult &R,
3067 ArrayRef<QualType> ArgTys,
3068 bool AllowRaw, bool AllowTemplate,
3069 bool AllowStringTemplate) {
3071 assert(R.getResultKind() != LookupResult::Ambiguous &&
3072 "literal operator lookup can't be ambiguous");
3074 // Filter the lookup results appropriately.
3075 LookupResult::Filter F = R.makeFilter();
3077 bool FoundRaw = false;
3078 bool FoundTemplate = false;
3079 bool FoundStringTemplate = false;
3080 bool FoundExactMatch = false;
3082 while (F.hasNext()) {
3084 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
3085 D = USD->getTargetDecl();
3087 // If the declaration we found is invalid, skip it.
3088 if (D->isInvalidDecl()) {
3094 bool IsTemplate = false;
3095 bool IsStringTemplate = false;
3096 bool IsExactMatch = false;
3098 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
3099 if (FD->getNumParams() == 1 &&
3100 FD->getParamDecl(0)->getType()->getAs<PointerType>())
3102 else if (FD->getNumParams() == ArgTys.size()) {
3103 IsExactMatch = true;
3104 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
3105 QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
3106 if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
3107 IsExactMatch = false;
3113 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) {
3114 TemplateParameterList *Params = FD->getTemplateParameters();
3115 if (Params->size() == 1)
3118 IsStringTemplate = true;
3122 FoundExactMatch = true;
3124 AllowTemplate = false;
3125 AllowStringTemplate = false;
3126 if (FoundRaw || FoundTemplate || FoundStringTemplate) {
3127 // Go through again and remove the raw and template decls we've
3130 FoundRaw = FoundTemplate = FoundStringTemplate = false;
3132 } else if (AllowRaw && IsRaw) {
3134 } else if (AllowTemplate && IsTemplate) {
3135 FoundTemplate = true;
3136 } else if (AllowStringTemplate && IsStringTemplate) {
3137 FoundStringTemplate = true;
3145 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
3146 // parameter type, that is used in preference to a raw literal operator
3147 // or literal operator template.
3148 if (FoundExactMatch)
3151 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
3152 // operator template, but not both.
3153 if (FoundRaw && FoundTemplate) {
3154 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
3155 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
3156 NoteOverloadCandidate(*I, (*I)->getUnderlyingDecl()->getAsFunction());
3164 return LOLR_Template;
3166 if (FoundStringTemplate)
3167 return LOLR_StringTemplate;
3169 // Didn't find anything we could use.
3170 Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
3171 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
3172 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
3173 << (AllowTemplate || AllowStringTemplate);
3177 void ADLResult::insert(NamedDecl *New) {
3178 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
3180 // If we haven't yet seen a decl for this key, or the last decl
3181 // was exactly this one, we're done.
3182 if (Old == nullptr || Old == New) {
3187 // Otherwise, decide which is a more recent redeclaration.
3188 FunctionDecl *OldFD = Old->getAsFunction();
3189 FunctionDecl *NewFD = New->getAsFunction();
3191 FunctionDecl *Cursor = NewFD;
3193 Cursor = Cursor->getPreviousDecl();
3195 // If we got to the end without finding OldFD, OldFD is the newer
3196 // declaration; leave things as they are.
3197 if (!Cursor) return;
3199 // If we do find OldFD, then NewFD is newer.
3200 if (Cursor == OldFD) break;
3202 // Otherwise, keep looking.
3208 void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
3209 ArrayRef<Expr *> Args, ADLResult &Result) {
3210 // Find all of the associated namespaces and classes based on the
3211 // arguments we have.
3212 AssociatedNamespaceSet AssociatedNamespaces;
3213 AssociatedClassSet AssociatedClasses;
3214 FindAssociatedClassesAndNamespaces(Loc, Args,
3215 AssociatedNamespaces,
3218 // C++ [basic.lookup.argdep]p3:
3219 // Let X be the lookup set produced by unqualified lookup (3.4.1)
3220 // and let Y be the lookup set produced by argument dependent
3221 // lookup (defined as follows). If X contains [...] then Y is
3222 // empty. Otherwise Y is the set of declarations found in the
3223 // namespaces associated with the argument types as described
3224 // below. The set of declarations found by the lookup of the name
3225 // is the union of X and Y.
3227 // Here, we compute Y and add its members to the overloaded
3229 for (auto *NS : AssociatedNamespaces) {
3230 // When considering an associated namespace, the lookup is the
3231 // same as the lookup performed when the associated namespace is
3232 // used as a qualifier (3.4.3.2) except that:
3234 // -- Any using-directives in the associated namespace are
3237 // -- Any namespace-scope friend functions declared in
3238 // associated classes are visible within their respective
3239 // namespaces even if they are not visible during an ordinary
3241 DeclContext::lookup_result R = NS->lookup(Name);
3243 // If the only declaration here is an ordinary friend, consider
3244 // it only if it was declared in an associated classes.
3245 if ((D->getIdentifierNamespace() & Decl::IDNS_Ordinary) == 0) {
3246 // If it's neither ordinarily visible nor a friend, we can't find it.
3247 if ((D->getIdentifierNamespace() & Decl::IDNS_OrdinaryFriend) == 0)
3250 bool DeclaredInAssociatedClass = false;
3251 for (Decl *DI = D; DI; DI = DI->getPreviousDecl()) {
3252 DeclContext *LexDC = DI->getLexicalDeclContext();
3253 if (isa<CXXRecordDecl>(LexDC) &&
3254 AssociatedClasses.count(cast<CXXRecordDecl>(LexDC)) &&
3255 isVisible(cast<NamedDecl>(DI))) {
3256 DeclaredInAssociatedClass = true;
3260 if (!DeclaredInAssociatedClass)
3264 if (isa<UsingShadowDecl>(D))
3265 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3267 if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D))
3270 if (!isVisible(D) && !(D = findAcceptableDecl(*this, D)))
3278 //----------------------------------------------------------------------------
3279 // Search for all visible declarations.
3280 //----------------------------------------------------------------------------
3281 VisibleDeclConsumer::~VisibleDeclConsumer() { }
3283 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
3287 class ShadowContextRAII;
3289 class VisibleDeclsRecord {
3291 /// \brief An entry in the shadow map, which is optimized to store a
3292 /// single declaration (the common case) but can also store a list
3293 /// of declarations.
3294 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
3297 /// \brief A mapping from declaration names to the declarations that have
3298 /// this name within a particular scope.
3299 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
3301 /// \brief A list of shadow maps, which is used to model name hiding.
3302 std::list<ShadowMap> ShadowMaps;
3304 /// \brief The declaration contexts we have already visited.
3305 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
3307 friend class ShadowContextRAII;
3310 /// \brief Determine whether we have already visited this context
3311 /// (and, if not, note that we are going to visit that context now).
3312 bool visitedContext(DeclContext *Ctx) {
3313 return !VisitedContexts.insert(Ctx).second;
3316 bool alreadyVisitedContext(DeclContext *Ctx) {
3317 return VisitedContexts.count(Ctx);
3320 /// \brief Determine whether the given declaration is hidden in the
3323 /// \returns the declaration that hides the given declaration, or
3324 /// NULL if no such declaration exists.
3325 NamedDecl *checkHidden(NamedDecl *ND);
3327 /// \brief Add a declaration to the current shadow map.
3328 void add(NamedDecl *ND) {
3329 ShadowMaps.back()[ND->getDeclName()].push_back(ND);
3333 /// \brief RAII object that records when we've entered a shadow context.
3334 class ShadowContextRAII {
3335 VisibleDeclsRecord &Visible;
3337 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
3340 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
3341 Visible.ShadowMaps.emplace_back();
3344 ~ShadowContextRAII() {
3345 Visible.ShadowMaps.pop_back();
3349 } // end anonymous namespace
3351 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
3352 unsigned IDNS = ND->getIdentifierNamespace();
3353 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
3354 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
3355 SM != SMEnd; ++SM) {
3356 ShadowMap::iterator Pos = SM->find(ND->getDeclName());
3357 if (Pos == SM->end())
3360 for (auto *D : Pos->second) {
3361 // A tag declaration does not hide a non-tag declaration.
3362 if (D->hasTagIdentifierNamespace() &&
3363 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
3364 Decl::IDNS_ObjCProtocol)))
3367 // Protocols are in distinct namespaces from everything else.
3368 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
3369 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
3370 D->getIdentifierNamespace() != IDNS)
3373 // Functions and function templates in the same scope overload
3374 // rather than hide. FIXME: Look for hiding based on function
3376 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3377 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3378 SM == ShadowMaps.rbegin())
3381 // A shadow declaration that's created by a resolved using declaration
3382 // is not hidden by the same using declaration.
3383 if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) &&
3384 cast<UsingShadowDecl>(ND)->getUsingDecl() == D)
3387 // We've found a declaration that hides this one.
3395 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
3396 bool QualifiedNameLookup,
3398 VisibleDeclConsumer &Consumer,
3399 VisibleDeclsRecord &Visited,
3400 bool IncludeDependentBases = false) {
3404 // Make sure we don't visit the same context twice.
3405 if (Visited.visitedContext(Ctx->getPrimaryContext()))
3408 // Outside C++, lookup results for the TU live on identifiers.
3409 if (isa<TranslationUnitDecl>(Ctx) &&
3410 !Result.getSema().getLangOpts().CPlusPlus) {
3411 auto &S = Result.getSema();
3412 auto &Idents = S.Context.Idents;
3414 // Ensure all external identifiers are in the identifier table.
3415 if (IdentifierInfoLookup *External = Idents.getExternalIdentifierLookup()) {
3416 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
3417 for (StringRef Name = Iter->Next(); !Name.empty(); Name = Iter->Next())
3421 // Walk all lookup results in the TU for each identifier.
3422 for (const auto &Ident : Idents) {
3423 for (auto I = S.IdResolver.begin(Ident.getValue()),
3424 E = S.IdResolver.end();
3426 if (S.IdResolver.isDeclInScope(*I, Ctx)) {
3427 if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
3428 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3438 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
3439 Result.getSema().ForceDeclarationOfImplicitMembers(Class);
3441 // Enumerate all of the results in this context.
3442 for (DeclContextLookupResult R : Ctx->lookups()) {
3444 if (auto *ND = Result.getAcceptableDecl(D)) {
3445 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3451 // Traverse using directives for qualified name lookup.
3452 if (QualifiedNameLookup) {
3453 ShadowContextRAII Shadow(Visited);
3454 for (auto I : Ctx->using_directives()) {
3455 LookupVisibleDecls(I->getNominatedNamespace(), Result,
3456 QualifiedNameLookup, InBaseClass, Consumer, Visited,
3457 IncludeDependentBases);
3461 // Traverse the contexts of inherited C++ classes.
3462 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
3463 if (!Record->hasDefinition())
3466 for (const auto &B : Record->bases()) {
3467 QualType BaseType = B.getType();
3470 if (BaseType->isDependentType()) {
3471 if (!IncludeDependentBases) {
3472 // Don't look into dependent bases, because name lookup can't look
3476 const auto *TST = BaseType->getAs<TemplateSpecializationType>();
3479 TemplateName TN = TST->getTemplateName();
3481 dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl());
3484 RD = TD->getTemplatedDecl();
3486 const auto *Record = BaseType->getAs<RecordType>();
3489 RD = Record->getDecl();
3492 // FIXME: It would be nice to be able to determine whether referencing
3493 // a particular member would be ambiguous. For example, given
3495 // struct A { int member; };
3496 // struct B { int member; };
3497 // struct C : A, B { };
3499 // void f(C *c) { c->### }
3501 // accessing 'member' would result in an ambiguity. However, we
3502 // could be smart enough to qualify the member with the base
3511 // Find results in this base class (and its bases).
3512 ShadowContextRAII Shadow(Visited);
3513 LookupVisibleDecls(RD, Result, QualifiedNameLookup, true, Consumer,
3514 Visited, IncludeDependentBases);
3518 // Traverse the contexts of Objective-C classes.
3519 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
3520 // Traverse categories.
3521 for (auto *Cat : IFace->visible_categories()) {
3522 ShadowContextRAII Shadow(Visited);
3523 LookupVisibleDecls(Cat, Result, QualifiedNameLookup, false,
3527 // Traverse protocols.
3528 for (auto *I : IFace->all_referenced_protocols()) {
3529 ShadowContextRAII Shadow(Visited);
3530 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3534 // Traverse the superclass.
3535 if (IFace->getSuperClass()) {
3536 ShadowContextRAII Shadow(Visited);
3537 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup,
3538 true, Consumer, Visited);
3541 // If there is an implementation, traverse it. We do this to find
3542 // synthesized ivars.
3543 if (IFace->getImplementation()) {
3544 ShadowContextRAII Shadow(Visited);
3545 LookupVisibleDecls(IFace->getImplementation(), Result,
3546 QualifiedNameLookup, InBaseClass, Consumer, Visited);
3548 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
3549 for (auto *I : Protocol->protocols()) {
3550 ShadowContextRAII Shadow(Visited);
3551 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3554 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
3555 for (auto *I : Category->protocols()) {
3556 ShadowContextRAII Shadow(Visited);
3557 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3561 // If there is an implementation, traverse it.
3562 if (Category->getImplementation()) {
3563 ShadowContextRAII Shadow(Visited);
3564 LookupVisibleDecls(Category->getImplementation(), Result,
3565 QualifiedNameLookup, true, Consumer, Visited);
3570 static void LookupVisibleDecls(Scope *S, LookupResult &Result,
3571 UnqualUsingDirectiveSet &UDirs,
3572 VisibleDeclConsumer &Consumer,
3573 VisibleDeclsRecord &Visited) {
3577 if (!S->getEntity() ||
3579 !Visited.alreadyVisitedContext(S->getEntity())) ||
3580 (S->getEntity())->isFunctionOrMethod()) {
3581 FindLocalExternScope FindLocals(Result);
3582 // Walk through the declarations in this Scope.
3583 for (auto *D : S->decls()) {
3584 if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
3585 if ((ND = Result.getAcceptableDecl(ND))) {
3586 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
3592 // FIXME: C++ [temp.local]p8
3593 DeclContext *Entity = nullptr;
3594 if (S->getEntity()) {
3595 // Look into this scope's declaration context, along with any of its
3596 // parent lookup contexts (e.g., enclosing classes), up to the point
3597 // where we hit the context stored in the next outer scope.
3598 Entity = S->getEntity();
3599 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME
3601 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
3602 Ctx = Ctx->getLookupParent()) {
3603 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
3604 if (Method->isInstanceMethod()) {
3605 // For instance methods, look for ivars in the method's interface.
3606 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
3607 Result.getNameLoc(), Sema::LookupMemberName);
3608 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
3609 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false,
3610 /*InBaseClass=*/false, Consumer, Visited);
3614 // We've already performed all of the name lookup that we need
3615 // to for Objective-C methods; the next context will be the
3620 if (Ctx->isFunctionOrMethod())
3623 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false,
3624 /*InBaseClass=*/false, Consumer, Visited);
3626 } else if (!S->getParent()) {
3627 // Look into the translation unit scope. We walk through the translation
3628 // unit's declaration context, because the Scope itself won't have all of
3629 // the declarations if we loaded a precompiled header.
3630 // FIXME: We would like the translation unit's Scope object to point to the
3631 // translation unit, so we don't need this special "if" branch. However,
3632 // doing so would force the normal C++ name-lookup code to look into the
3633 // translation unit decl when the IdentifierInfo chains would suffice.
3634 // Once we fix that problem (which is part of a more general "don't look
3635 // in DeclContexts unless we have to" optimization), we can eliminate this.
3636 Entity = Result.getSema().Context.getTranslationUnitDecl();
3637 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false,
3638 /*InBaseClass=*/false, Consumer, Visited);
3642 // Lookup visible declarations in any namespaces found by using
3644 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity))
3645 LookupVisibleDecls(const_cast<DeclContext *>(UUE.getNominatedNamespace()),
3646 Result, /*QualifiedNameLookup=*/false,
3647 /*InBaseClass=*/false, Consumer, Visited);
3650 // Lookup names in the parent scope.
3651 ShadowContextRAII Shadow(Visited);
3652 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited);
3655 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
3656 VisibleDeclConsumer &Consumer,
3657 bool IncludeGlobalScope) {
3658 // Determine the set of using directives available during
3659 // unqualified name lookup.
3661 UnqualUsingDirectiveSet UDirs;
3662 if (getLangOpts().CPlusPlus) {
3663 // Find the first namespace or translation-unit scope.
3664 while (S && !isNamespaceOrTranslationUnitScope(S))
3667 UDirs.visitScopeChain(Initial, S);
3671 // Look for visible declarations.
3672 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3673 Result.setAllowHidden(Consumer.includeHiddenDecls());
3674 VisibleDeclsRecord Visited;
3675 if (!IncludeGlobalScope)
3676 Visited.visitedContext(Context.getTranslationUnitDecl());
3677 ShadowContextRAII Shadow(Visited);
3678 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited);
3681 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
3682 VisibleDeclConsumer &Consumer,
3683 bool IncludeGlobalScope,
3684 bool IncludeDependentBases) {
3685 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3686 Result.setAllowHidden(Consumer.includeHiddenDecls());
3687 VisibleDeclsRecord Visited;
3688 if (!IncludeGlobalScope)
3689 Visited.visitedContext(Context.getTranslationUnitDecl());
3690 ShadowContextRAII Shadow(Visited);
3691 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true,
3692 /*InBaseClass=*/false, Consumer, Visited,
3693 IncludeDependentBases);
3696 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name.
3697 /// If GnuLabelLoc is a valid source location, then this is a definition
3698 /// of an __label__ label name, otherwise it is a normal label definition
3700 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc,
3701 SourceLocation GnuLabelLoc) {
3702 // Do a lookup to see if we have a label with this name already.
3703 NamedDecl *Res = nullptr;
3705 if (GnuLabelLoc.isValid()) {
3706 // Local label definitions always shadow existing labels.
3707 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
3708 Scope *S = CurScope;
3709 PushOnScopeChains(Res, S, true);
3710 return cast<LabelDecl>(Res);
3713 // Not a GNU local label.
3714 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration);
3715 // If we found a label, check to see if it is in the same context as us.
3716 // When in a Block, we don't want to reuse a label in an enclosing function.
3717 if (Res && Res->getDeclContext() != CurContext)
3720 // If not forward referenced or defined already, create the backing decl.
3721 Res = LabelDecl::Create(Context, CurContext, Loc, II);
3722 Scope *S = CurScope->getFnParent();
3723 assert(S && "Not in a function?");
3724 PushOnScopeChains(Res, S, true);
3726 return cast<LabelDecl>(Res);
3729 //===----------------------------------------------------------------------===//
3731 //===----------------------------------------------------------------------===//
3733 static bool isCandidateViable(CorrectionCandidateCallback &CCC,
3734 TypoCorrection &Candidate) {
3735 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
3736 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
3739 static void LookupPotentialTypoResult(Sema &SemaRef,
3741 IdentifierInfo *Name,
3742 Scope *S, CXXScopeSpec *SS,
3743 DeclContext *MemberContext,
3744 bool EnteringContext,
3745 bool isObjCIvarLookup,
3748 /// \brief Check whether the declarations found for a typo correction are
3749 /// visible, and if none of them are, convert the correction to an 'import
3750 /// a module' correction.
3751 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
3752 if (TC.begin() == TC.end())
3755 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
3757 for (/**/; DI != DE; ++DI)
3758 if (!LookupResult::isVisible(SemaRef, *DI))
3760 // Nothing to do if all decls are visible.
3764 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
3765 bool AnyVisibleDecls = !NewDecls.empty();
3767 for (/**/; DI != DE; ++DI) {
3768 NamedDecl *VisibleDecl = *DI;
3769 if (!LookupResult::isVisible(SemaRef, *DI))
3770 VisibleDecl = findAcceptableDecl(SemaRef, *DI);
3773 if (!AnyVisibleDecls) {
3774 // Found a visible decl, discard all hidden ones.
3775 AnyVisibleDecls = true;
3778 NewDecls.push_back(VisibleDecl);
3779 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
3780 NewDecls.push_back(*DI);
3783 if (NewDecls.empty())
3784 TC = TypoCorrection();
3786 TC.setCorrectionDecls(NewDecls);
3787 TC.setRequiresImport(!AnyVisibleDecls);
3791 // Fill the supplied vector with the IdentifierInfo pointers for each piece of
3792 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
3793 // fill the vector with the IdentifierInfo pointers for "foo" and "bar").
3794 static void getNestedNameSpecifierIdentifiers(
3795 NestedNameSpecifier *NNS,
3796 SmallVectorImpl<const IdentifierInfo*> &Identifiers) {
3797 if (NestedNameSpecifier *Prefix = NNS->getPrefix())
3798 getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
3800 Identifiers.clear();
3802 const IdentifierInfo *II = nullptr;
3804 switch (NNS->getKind()) {
3805 case NestedNameSpecifier::Identifier:
3806 II = NNS->getAsIdentifier();
3809 case NestedNameSpecifier::Namespace:
3810 if (NNS->getAsNamespace()->isAnonymousNamespace())
3812 II = NNS->getAsNamespace()->getIdentifier();
3815 case NestedNameSpecifier::NamespaceAlias:
3816 II = NNS->getAsNamespaceAlias()->getIdentifier();
3819 case NestedNameSpecifier::TypeSpecWithTemplate:
3820 case NestedNameSpecifier::TypeSpec:
3821 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier();
3824 case NestedNameSpecifier::Global:
3825 case NestedNameSpecifier::Super:
3830 Identifiers.push_back(II);
3833 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
3834 DeclContext *Ctx, bool InBaseClass) {
3835 // Don't consider hidden names for typo correction.
3839 // Only consider entities with identifiers for names, ignoring
3840 // special names (constructors, overloaded operators, selectors,
3842 IdentifierInfo *Name = ND->getIdentifier();
3846 // Only consider visible declarations and declarations from modules with
3847 // names that exactly match.
3848 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo &&
3849 !findAcceptableDecl(SemaRef, ND))
3852 FoundName(Name->getName());
3855 void TypoCorrectionConsumer::FoundName(StringRef Name) {
3856 // Compute the edit distance between the typo and the name of this
3857 // entity, and add the identifier to the list of results.
3858 addName(Name, nullptr);
3861 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) {
3862 // Compute the edit distance between the typo and this keyword,
3863 // and add the keyword to the list of results.
3864 addName(Keyword, nullptr, nullptr, true);
3867 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
3868 NestedNameSpecifier *NNS, bool isKeyword) {
3869 // Use a simple length-based heuristic to determine the minimum possible
3870 // edit distance. If the minimum isn't good enough, bail out early.
3871 StringRef TypoStr = Typo->getName();
3872 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
3873 if (MinED && TypoStr.size() / MinED < 3)
3876 // Compute an upper bound on the allowable edit distance, so that the
3877 // edit-distance algorithm can short-circuit.
3878 unsigned UpperBound = (TypoStr.size() + 2) / 3 + 1;
3879 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
3880 if (ED >= UpperBound) return;
3882 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
3883 if (isKeyword) TC.makeKeyword();
3884 TC.setCorrectionRange(nullptr, Result.getLookupNameInfo());
3888 static const unsigned MaxTypoDistanceResultSets = 5;
3890 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) {
3891 StringRef TypoStr = Typo->getName();
3892 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
3894 // For very short typos, ignore potential corrections that have a different
3895 // base identifier from the typo or which have a normalized edit distance
3896 // longer than the typo itself.
3897 if (TypoStr.size() < 3 &&
3898 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
3901 // If the correction is resolved but is not viable, ignore it.
3902 if (Correction.isResolved()) {
3903 checkCorrectionVisibility(SemaRef, Correction);
3904 if (!Correction || !isCandidateViable(*CorrectionValidator, Correction))
3908 TypoResultList &CList =
3909 CorrectionResults[Correction.getEditDistance(false)][Name];
3911 if (!CList.empty() && !CList.back().isResolved())
3913 if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
3914 std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts());
3915 for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end();
3916 RI != RIEnd; ++RI) {
3917 // If the Correction refers to a decl already in the result list,
3918 // replace the existing result if the string representation of Correction
3919 // comes before the current result alphabetically, then stop as there is
3920 // nothing more to be done to add Correction to the candidate set.
3921 if (RI->getCorrectionDecl() == NewND) {
3922 if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts()))
3928 if (CList.empty() || Correction.isResolved())
3929 CList.push_back(Correction);
3931 while (CorrectionResults.size() > MaxTypoDistanceResultSets)
3932 CorrectionResults.erase(std::prev(CorrectionResults.end()));
3935 void TypoCorrectionConsumer::addNamespaces(
3936 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
3937 SearchNamespaces = true;
3939 for (auto KNPair : KnownNamespaces)
3940 Namespaces.addNameSpecifier(KNPair.first);
3942 bool SSIsTemplate = false;
3943 if (NestedNameSpecifier *NNS =
3944 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) {
3945 if (const Type *T = NNS->getAsType())
3946 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization;
3948 // Do not transform this into an iterator-based loop. The loop body can
3949 // trigger the creation of further types (through lazy deserialization) and
3950 // invalide iterators into this list.
3951 auto &Types = SemaRef.getASTContext().getTypes();
3952 for (unsigned I = 0; I != Types.size(); ++I) {
3953 const auto *TI = Types[I];
3954 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
3955 CD = CD->getCanonicalDecl();
3956 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
3957 !CD->isUnion() && CD->getIdentifier() &&
3958 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
3959 (CD->isBeingDefined() || CD->isCompleteDefinition()))
3960 Namespaces.addNameSpecifier(CD);
3965 const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() {
3966 if (++CurrentTCIndex < ValidatedCorrections.size())
3967 return ValidatedCorrections[CurrentTCIndex];
3969 CurrentTCIndex = ValidatedCorrections.size();
3970 while (!CorrectionResults.empty()) {
3971 auto DI = CorrectionResults.begin();
3972 if (DI->second.empty()) {
3973 CorrectionResults.erase(DI);
3977 auto RI = DI->second.begin();
3978 if (RI->second.empty()) {
3979 DI->second.erase(RI);
3980 performQualifiedLookups();
3984 TypoCorrection TC = RI->second.pop_back_val();
3985 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) {
3986 ValidatedCorrections.push_back(TC);
3987 return ValidatedCorrections[CurrentTCIndex];
3990 return ValidatedCorrections[0]; // The empty correction.
3993 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
3994 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
3995 DeclContext *TempMemberContext = MemberContext;
3996 CXXScopeSpec *TempSS = SS.get();
3998 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
4000 CorrectionValidator->IsObjCIvarLookup,
4001 Name == Typo && !Candidate.WillReplaceSpecifier());
4002 switch (Result.getResultKind()) {
4003 case LookupResult::NotFound:
4004 case LookupResult::NotFoundInCurrentInstantiation:
4005 case LookupResult::FoundUnresolvedValue:
4007 // Immediately retry the lookup without the given CXXScopeSpec
4009 Candidate.WillReplaceSpecifier(true);
4012 if (TempMemberContext) {
4015 TempMemberContext = nullptr;
4018 if (SearchNamespaces)
4019 QualifiedResults.push_back(Candidate);
4022 case LookupResult::Ambiguous:
4023 // We don't deal with ambiguities.
4026 case LookupResult::Found:
4027 case LookupResult::FoundOverloaded:
4028 // Store all of the Decls for overloaded symbols
4029 for (auto *TRD : Result)
4030 Candidate.addCorrectionDecl(TRD);
4031 checkCorrectionVisibility(SemaRef, Candidate);
4032 if (!isCandidateViable(*CorrectionValidator, Candidate)) {
4033 if (SearchNamespaces)
4034 QualifiedResults.push_back(Candidate);
4037 Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4043 void TypoCorrectionConsumer::performQualifiedLookups() {
4044 unsigned TypoLen = Typo->getName().size();
4045 for (const TypoCorrection &QR : QualifiedResults) {
4046 for (const auto &NSI : Namespaces) {
4047 DeclContext *Ctx = NSI.DeclCtx;
4048 const Type *NSType = NSI.NameSpecifier->getAsType();
4050 // If the current NestedNameSpecifier refers to a class and the
4051 // current correction candidate is the name of that class, then skip
4052 // it as it is unlikely a qualified version of the class' constructor
4053 // is an appropriate correction.
4054 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() :
4056 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
4060 TypoCorrection TC(QR);
4061 TC.ClearCorrectionDecls();
4062 TC.setCorrectionSpecifier(NSI.NameSpecifier);
4063 TC.setQualifierDistance(NSI.EditDistance);
4064 TC.setCallbackDistance(0); // Reset the callback distance
4066 // If the current correction candidate and namespace combination are
4067 // too far away from the original typo based on the normalized edit
4068 // distance, then skip performing a qualified name lookup.
4069 unsigned TmpED = TC.getEditDistance(true);
4070 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4071 TypoLen / TmpED < 3)
4075 Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4076 if (!SemaRef.LookupQualifiedName(Result, Ctx))
4079 // Any corrections added below will be validated in subsequent
4080 // iterations of the main while() loop over the Consumer's contents.
4081 switch (Result.getResultKind()) {
4082 case LookupResult::Found:
4083 case LookupResult::FoundOverloaded: {
4084 if (SS && SS->isValid()) {
4085 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
4086 std::string OldQualified;
4087 llvm::raw_string_ostream OldOStream(OldQualified);
4088 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy());
4089 OldOStream << Typo->getName();
4090 // If correction candidate would be an identical written qualified
4091 // identifer, then the existing CXXScopeSpec probably included a
4092 // typedef that didn't get accounted for properly.
4093 if (OldOStream.str() == NewQualified)
4096 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4097 TRD != TRDEnd; ++TRD) {
4098 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
4099 NSType ? NSType->getAsCXXRecordDecl()
4101 TRD.getPair()) == Sema::AR_accessible)
4102 TC.addCorrectionDecl(*TRD);
4104 if (TC.isResolved()) {
4105 TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4110 case LookupResult::NotFound:
4111 case LookupResult::NotFoundInCurrentInstantiation:
4112 case LookupResult::Ambiguous:
4113 case LookupResult::FoundUnresolvedValue:
4118 QualifiedResults.clear();
4121 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4122 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4123 : Context(Context), CurContextChain(buildContextChain(CurContext)) {
4124 if (NestedNameSpecifier *NNS =
4125 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) {
4126 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4127 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4129 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
4131 // Build the list of identifiers that would be used for an absolute
4132 // (from the global context) NestedNameSpecifier referring to the current
4134 for (DeclContext *C : llvm::reverse(CurContextChain)) {
4135 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C))
4136 CurContextIdentifiers.push_back(ND->getIdentifier());
4139 // Add the global context as a NestedNameSpecifier
4140 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
4141 NestedNameSpecifier::GlobalSpecifier(Context), 1};
4142 DistanceMap[1].push_back(SI);
4145 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
4146 DeclContext *Start) -> DeclContextList {
4147 assert(Start && "Building a context chain from a null context");
4148 DeclContextList Chain;
4149 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
4150 DC = DC->getLookupParent()) {
4151 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
4152 if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
4153 !(ND && ND->isAnonymousNamespace()))
4154 Chain.push_back(DC->getPrimaryContext());
4160 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
4161 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) {
4162 unsigned NumSpecifiers = 0;
4163 for (DeclContext *C : llvm::reverse(DeclChain)) {
4164 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) {
4165 NNS = NestedNameSpecifier::Create(Context, NNS, ND);
4167 } else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) {
4168 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(),
4169 RD->getTypeForDecl());
4173 return NumSpecifiers;
4176 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
4178 NestedNameSpecifier *NNS = nullptr;
4179 unsigned NumSpecifiers = 0;
4180 DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
4181 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
4183 // Eliminate common elements from the two DeclContext chains.
4184 for (DeclContext *C : llvm::reverse(CurContextChain)) {
4185 if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C)
4187 NamespaceDeclChain.pop_back();
4190 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
4191 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
4193 // Add an explicit leading '::' specifier if needed.
4194 if (NamespaceDeclChain.empty()) {
4195 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4196 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4198 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4199 } else if (NamedDecl *ND =
4200 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
4201 IdentifierInfo *Name = ND->getIdentifier();
4202 bool SameNameSpecifier = false;
4203 if (std::find(CurNameSpecifierIdentifiers.begin(),
4204 CurNameSpecifierIdentifiers.end(),
4205 Name) != CurNameSpecifierIdentifiers.end()) {
4206 std::string NewNameSpecifier;
4207 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
4208 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
4209 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4210 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4211 SpecifierOStream.flush();
4212 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
4214 if (SameNameSpecifier ||
4215 std::find(CurContextIdentifiers.begin(), CurContextIdentifiers.end(),
4216 Name) != CurContextIdentifiers.end()) {
4217 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4218 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4220 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4224 // If the built NestedNameSpecifier would be replacing an existing
4225 // NestedNameSpecifier, use the number of component identifiers that
4226 // would need to be changed as the edit distance instead of the number
4227 // of components in the built NestedNameSpecifier.
4228 if (NNS && !CurNameSpecifierIdentifiers.empty()) {
4229 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
4230 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4231 NumSpecifiers = llvm::ComputeEditDistance(
4232 llvm::makeArrayRef(CurNameSpecifierIdentifiers),
4233 llvm::makeArrayRef(NewNameSpecifierIdentifiers));
4236 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
4237 DistanceMap[NumSpecifiers].push_back(SI);
4240 /// \brief Perform name lookup for a possible result for typo correction.
4241 static void LookupPotentialTypoResult(Sema &SemaRef,
4243 IdentifierInfo *Name,
4244 Scope *S, CXXScopeSpec *SS,
4245 DeclContext *MemberContext,
4246 bool EnteringContext,
4247 bool isObjCIvarLookup,
4249 Res.suppressDiagnostics();
4251 Res.setLookupName(Name);
4252 Res.setAllowHidden(FindHidden);
4253 if (MemberContext) {
4254 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
4255 if (isObjCIvarLookup) {
4256 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
4263 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(
4264 Name, ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
4271 SemaRef.LookupQualifiedName(Res, MemberContext);
4275 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
4278 // Fake ivar lookup; this should really be part of
4279 // LookupParsedName.
4280 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
4281 if (Method->isInstanceMethod() && Method->getClassInterface() &&
4283 (Res.isSingleResult() &&
4284 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) {
4285 if (ObjCIvarDecl *IV
4286 = Method->getClassInterface()->lookupInstanceVariable(Name)) {
4294 /// \brief Add keywords to the consumer as possible typo corrections.
4295 static void AddKeywordsToConsumer(Sema &SemaRef,
4296 TypoCorrectionConsumer &Consumer,
4297 Scope *S, CorrectionCandidateCallback &CCC,
4298 bool AfterNestedNameSpecifier) {
4299 if (AfterNestedNameSpecifier) {
4300 // For 'X::', we know exactly which keywords can appear next.
4301 Consumer.addKeywordResult("template");
4302 if (CCC.WantExpressionKeywords)
4303 Consumer.addKeywordResult("operator");
4307 if (CCC.WantObjCSuper)
4308 Consumer.addKeywordResult("super");
4310 if (CCC.WantTypeSpecifiers) {
4311 // Add type-specifier keywords to the set of results.
4312 static const char *const CTypeSpecs[] = {
4313 "char", "const", "double", "enum", "float", "int", "long", "short",
4314 "signed", "struct", "union", "unsigned", "void", "volatile",
4315 "_Complex", "_Imaginary",
4316 // storage-specifiers as well
4317 "extern", "inline", "static", "typedef"
4320 const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs);
4321 for (unsigned I = 0; I != NumCTypeSpecs; ++I)
4322 Consumer.addKeywordResult(CTypeSpecs[I]);
4324 if (SemaRef.getLangOpts().C99)
4325 Consumer.addKeywordResult("restrict");
4326 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
4327 Consumer.addKeywordResult("bool");
4328 else if (SemaRef.getLangOpts().C99)
4329 Consumer.addKeywordResult("_Bool");
4331 if (SemaRef.getLangOpts().CPlusPlus) {
4332 Consumer.addKeywordResult("class");
4333 Consumer.addKeywordResult("typename");
4334 Consumer.addKeywordResult("wchar_t");
4336 if (SemaRef.getLangOpts().CPlusPlus11) {
4337 Consumer.addKeywordResult("char16_t");
4338 Consumer.addKeywordResult("char32_t");
4339 Consumer.addKeywordResult("constexpr");
4340 Consumer.addKeywordResult("decltype");
4341 Consumer.addKeywordResult("thread_local");
4345 if (SemaRef.getLangOpts().GNUMode)
4346 Consumer.addKeywordResult("typeof");
4347 } else if (CCC.WantFunctionLikeCasts) {
4348 static const char *const CastableTypeSpecs[] = {
4349 "char", "double", "float", "int", "long", "short",
4350 "signed", "unsigned", "void"
4352 for (auto *kw : CastableTypeSpecs)
4353 Consumer.addKeywordResult(kw);
4356 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
4357 Consumer.addKeywordResult("const_cast");
4358 Consumer.addKeywordResult("dynamic_cast");
4359 Consumer.addKeywordResult("reinterpret_cast");
4360 Consumer.addKeywordResult("static_cast");
4363 if (CCC.WantExpressionKeywords) {
4364 Consumer.addKeywordResult("sizeof");
4365 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
4366 Consumer.addKeywordResult("false");
4367 Consumer.addKeywordResult("true");
4370 if (SemaRef.getLangOpts().CPlusPlus) {
4371 static const char *const CXXExprs[] = {
4372 "delete", "new", "operator", "throw", "typeid"
4374 const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs);
4375 for (unsigned I = 0; I != NumCXXExprs; ++I)
4376 Consumer.addKeywordResult(CXXExprs[I]);
4378 if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
4379 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
4380 Consumer.addKeywordResult("this");
4382 if (SemaRef.getLangOpts().CPlusPlus11) {
4383 Consumer.addKeywordResult("alignof");
4384 Consumer.addKeywordResult("nullptr");
4388 if (SemaRef.getLangOpts().C11) {
4389 // FIXME: We should not suggest _Alignof if the alignof macro
4391 Consumer.addKeywordResult("_Alignof");
4395 if (CCC.WantRemainingKeywords) {
4396 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
4398 static const char *const CStmts[] = {
4399 "do", "else", "for", "goto", "if", "return", "switch", "while" };
4400 const unsigned NumCStmts = llvm::array_lengthof(CStmts);
4401 for (unsigned I = 0; I != NumCStmts; ++I)
4402 Consumer.addKeywordResult(CStmts[I]);
4404 if (SemaRef.getLangOpts().CPlusPlus) {
4405 Consumer.addKeywordResult("catch");
4406 Consumer.addKeywordResult("try");
4409 if (S && S->getBreakParent())
4410 Consumer.addKeywordResult("break");
4412 if (S && S->getContinueParent())
4413 Consumer.addKeywordResult("continue");
4415 if (!SemaRef.getCurFunction()->SwitchStack.empty()) {
4416 Consumer.addKeywordResult("case");
4417 Consumer.addKeywordResult("default");
4420 if (SemaRef.getLangOpts().CPlusPlus) {
4421 Consumer.addKeywordResult("namespace");
4422 Consumer.addKeywordResult("template");
4425 if (S && S->isClassScope()) {
4426 Consumer.addKeywordResult("explicit");
4427 Consumer.addKeywordResult("friend");
4428 Consumer.addKeywordResult("mutable");
4429 Consumer.addKeywordResult("private");
4430 Consumer.addKeywordResult("protected");
4431 Consumer.addKeywordResult("public");
4432 Consumer.addKeywordResult("virtual");
4436 if (SemaRef.getLangOpts().CPlusPlus) {
4437 Consumer.addKeywordResult("using");
4439 if (SemaRef.getLangOpts().CPlusPlus11)
4440 Consumer.addKeywordResult("static_assert");
4445 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
4446 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4447 Scope *S, CXXScopeSpec *SS,
4448 std::unique_ptr<CorrectionCandidateCallback> CCC,
4449 DeclContext *MemberContext, bool EnteringContext,
4450 const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
4452 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
4453 DisableTypoCorrection)
4456 // In Microsoft mode, don't perform typo correction in a template member
4457 // function dependent context because it interferes with the "lookup into
4458 // dependent bases of class templates" feature.
4459 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
4460 isa<CXXMethodDecl>(CurContext))
4463 // We only attempt to correct typos for identifiers.
4464 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4468 // If the scope specifier itself was invalid, don't try to correct
4470 if (SS && SS->isInvalid())
4473 // Never try to correct typos during any kind of code synthesis.
4474 if (!CodeSynthesisContexts.empty())
4477 // Don't try to correct 'super'.
4478 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
4481 // Abort if typo correction already failed for this specific typo.
4482 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
4483 if (locs != TypoCorrectionFailures.end() &&
4484 locs->second.count(TypoName.getLoc()))
4487 // Don't try to correct the identifier "vector" when in AltiVec mode.
4488 // TODO: Figure out why typo correction misbehaves in this case, fix it, and
4489 // remove this workaround.
4490 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector"))
4493 // Provide a stop gap for files that are just seriously broken. Trying
4494 // to correct all typos can turn into a HUGE performance penalty, causing
4495 // some files to take minutes to get rejected by the parser.
4496 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
4497 if (Limit && TyposCorrected >= Limit)
4501 // If we're handling a missing symbol error, using modules, and the
4502 // special search all modules option is used, look for a missing import.
4503 if (ErrorRecovery && getLangOpts().Modules &&
4504 getLangOpts().ModulesSearchAll) {
4505 // The following has the side effect of loading the missing module.
4506 getModuleLoader().lookupMissingImports(Typo->getName(),
4507 TypoName.getLocStart());
4510 CorrectionCandidateCallback &CCCRef = *CCC;
4511 auto Consumer = llvm::make_unique<TypoCorrectionConsumer>(
4512 *this, TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4515 // Perform name lookup to find visible, similarly-named entities.
4516 bool IsUnqualifiedLookup = false;
4517 DeclContext *QualifiedDC = MemberContext;
4518 if (MemberContext) {
4519 LookupVisibleDecls(MemberContext, LookupKind, *Consumer);
4521 // Look in qualified interfaces.
4523 for (auto *I : OPT->quals())
4524 LookupVisibleDecls(I, LookupKind, *Consumer);
4526 } else if (SS && SS->isSet()) {
4527 QualifiedDC = computeDeclContext(*SS, EnteringContext);
4531 LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer);
4533 IsUnqualifiedLookup = true;
4536 // Determine whether we are going to search in the various namespaces for
4538 bool SearchNamespaces
4539 = getLangOpts().CPlusPlus &&
4540 (IsUnqualifiedLookup || (SS && SS->isSet()));
4542 if (IsUnqualifiedLookup || SearchNamespaces) {
4543 // For unqualified lookup, look through all of the names that we have
4544 // seen in this translation unit.
4545 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4546 for (const auto &I : Context.Idents)
4547 Consumer->FoundName(I.getKey());
4549 // Walk through identifiers in external identifier sources.
4550 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4551 if (IdentifierInfoLookup *External
4552 = Context.Idents.getExternalIdentifierLookup()) {
4553 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4555 StringRef Name = Iter->Next();
4559 Consumer->FoundName(Name);
4564 AddKeywordsToConsumer(*this, *Consumer, S, CCCRef, SS && SS->isNotEmpty());
4566 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
4567 // to search those namespaces.
4568 if (SearchNamespaces) {
4569 // Load any externally-known namespaces.
4570 if (ExternalSource && !LoadedExternalKnownNamespaces) {
4571 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
4572 LoadedExternalKnownNamespaces = true;
4573 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
4574 for (auto *N : ExternalKnownNamespaces)
4575 KnownNamespaces[N] = true;
4578 Consumer->addNamespaces(KnownNamespaces);
4584 /// \brief Try to "correct" a typo in the source code by finding
4585 /// visible declarations whose names are similar to the name that was
4586 /// present in the source code.
4588 /// \param TypoName the \c DeclarationNameInfo structure that contains
4589 /// the name that was present in the source code along with its location.
4591 /// \param LookupKind the name-lookup criteria used to search for the name.
4593 /// \param S the scope in which name lookup occurs.
4595 /// \param SS the nested-name-specifier that precedes the name we're
4596 /// looking for, if present.
4598 /// \param CCC A CorrectionCandidateCallback object that provides further
4599 /// validation of typo correction candidates. It also provides flags for
4600 /// determining the set of keywords permitted.
4602 /// \param MemberContext if non-NULL, the context in which to look for
4603 /// a member access expression.
4605 /// \param EnteringContext whether we're entering the context described by
4606 /// the nested-name-specifier SS.
4608 /// \param OPT when non-NULL, the search for visible declarations will
4609 /// also walk the protocols in the qualified interfaces of \p OPT.
4611 /// \returns a \c TypoCorrection containing the corrected name if the typo
4612 /// along with information such as the \c NamedDecl where the corrected name
4613 /// was declared, and any additional \c NestedNameSpecifier needed to access
4614 /// it (C++ only). The \c TypoCorrection is empty if there is no correction.
4615 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
4616 Sema::LookupNameKind LookupKind,
4617 Scope *S, CXXScopeSpec *SS,
4618 std::unique_ptr<CorrectionCandidateCallback> CCC,
4619 CorrectTypoKind Mode,
4620 DeclContext *MemberContext,
4621 bool EnteringContext,
4622 const ObjCObjectPointerType *OPT,
4623 bool RecordFailure) {
4624 assert(CCC && "CorrectTypo requires a CorrectionCandidateCallback");
4626 // Always let the ExternalSource have the first chance at correction, even
4627 // if we would otherwise have given up.
4628 if (ExternalSource) {
4629 if (TypoCorrection Correction = ExternalSource->CorrectTypo(
4630 TypoName, LookupKind, S, SS, *CCC, MemberContext, EnteringContext, OPT))
4634 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
4635 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
4636 // some instances of CTC_Unknown, while WantRemainingKeywords is true
4637 // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
4638 bool ObjCMessageReceiver = CCC->WantObjCSuper && !CCC->WantRemainingKeywords;
4640 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4641 auto Consumer = makeTypoCorrectionConsumer(
4642 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4643 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4646 return TypoCorrection();
4648 // If we haven't found anything, we're done.
4649 if (Consumer->empty())
4650 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4652 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4653 // is not more that about a third of the length of the typo's identifier.
4654 unsigned ED = Consumer->getBestEditDistance(true);
4655 unsigned TypoLen = Typo->getName().size();
4656 if (ED > 0 && TypoLen / ED < 3)
4657 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4659 TypoCorrection BestTC = Consumer->getNextCorrection();
4660 TypoCorrection SecondBestTC = Consumer->getNextCorrection();
4662 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4664 ED = BestTC.getEditDistance();
4666 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
4667 // If this was an unqualified lookup and we believe the callback
4668 // object wouldn't have filtered out possible corrections, note
4669 // that no correction was found.
4670 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4673 // If only a single name remains, return that result.
4674 if (!SecondBestTC ||
4675 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
4676 const TypoCorrection &Result = BestTC;
4678 // Don't correct to a keyword that's the same as the typo; the keyword
4679 // wasn't actually in scope.
4680 if (ED == 0 && Result.isKeyword())
4681 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4683 TypoCorrection TC = Result;
4684 TC.setCorrectionRange(SS, TypoName);
4685 checkCorrectionVisibility(*this, TC);
4687 } else if (SecondBestTC && ObjCMessageReceiver) {
4688 // Prefer 'super' when we're completing in a message-receiver
4691 if (BestTC.getCorrection().getAsString() != "super") {
4692 if (SecondBestTC.getCorrection().getAsString() == "super")
4693 BestTC = SecondBestTC;
4694 else if ((*Consumer)["super"].front().isKeyword())
4695 BestTC = (*Consumer)["super"].front();
4697 // Don't correct to a keyword that's the same as the typo; the keyword
4698 // wasn't actually in scope.
4699 if (BestTC.getEditDistance() == 0 ||
4700 BestTC.getCorrection().getAsString() != "super")
4701 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4703 BestTC.setCorrectionRange(SS, TypoName);
4707 // Record the failure's location if needed and return an empty correction. If
4708 // this was an unqualified lookup and we believe the callback object did not
4709 // filter out possible corrections, also cache the failure for the typo.
4710 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC);
4713 /// \brief Try to "correct" a typo in the source code by finding
4714 /// visible declarations whose names are similar to the name that was
4715 /// present in the source code.
4717 /// \param TypoName the \c DeclarationNameInfo structure that contains
4718 /// the name that was present in the source code along with its location.
4720 /// \param LookupKind the name-lookup criteria used to search for the name.
4722 /// \param S the scope in which name lookup occurs.
4724 /// \param SS the nested-name-specifier that precedes the name we're
4725 /// looking for, if present.
4727 /// \param CCC A CorrectionCandidateCallback object that provides further
4728 /// validation of typo correction candidates. It also provides flags for
4729 /// determining the set of keywords permitted.
4731 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print
4732 /// diagnostics when the actual typo correction is attempted.
4734 /// \param TRC A TypoRecoveryCallback functor that will be used to build an
4735 /// Expr from a typo correction candidate.
4737 /// \param MemberContext if non-NULL, the context in which to look for
4738 /// a member access expression.
4740 /// \param EnteringContext whether we're entering the context described by
4741 /// the nested-name-specifier SS.
4743 /// \param OPT when non-NULL, the search for visible declarations will
4744 /// also walk the protocols in the qualified interfaces of \p OPT.
4746 /// \returns a new \c TypoExpr that will later be replaced in the AST with an
4747 /// Expr representing the result of performing typo correction, or nullptr if
4748 /// typo correction is not possible. If nullptr is returned, no diagnostics will
4749 /// be emitted and it is the responsibility of the caller to emit any that are
4751 TypoExpr *Sema::CorrectTypoDelayed(
4752 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4753 Scope *S, CXXScopeSpec *SS,
4754 std::unique_ptr<CorrectionCandidateCallback> CCC,
4755 TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode,
4756 DeclContext *MemberContext, bool EnteringContext,
4757 const ObjCObjectPointerType *OPT) {
4758 assert(CCC && "CorrectTypoDelayed requires a CorrectionCandidateCallback");
4760 auto Consumer = makeTypoCorrectionConsumer(
4761 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4762 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4764 // Give the external sema source a chance to correct the typo.
4765 TypoCorrection ExternalTypo;
4766 if (ExternalSource && Consumer) {
4767 ExternalTypo = ExternalSource->CorrectTypo(
4768 TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(),
4769 MemberContext, EnteringContext, OPT);
4771 Consumer->addCorrection(ExternalTypo);
4774 if (!Consumer || Consumer->empty())
4777 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4778 // is not more that about a third of the length of the typo's identifier.
4779 unsigned ED = Consumer->getBestEditDistance(true);
4780 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4781 if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3)
4784 ExprEvalContexts.back().NumTypos++;
4785 return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC));
4788 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) {
4792 CorrectionDecls.clear();
4794 CorrectionDecls.push_back(CDecl);
4796 if (!CorrectionName)
4797 CorrectionName = CDecl->getDeclName();
4800 std::string TypoCorrection::getAsString(const LangOptions &LO) const {
4801 if (CorrectionNameSpec) {
4802 std::string tmpBuffer;
4803 llvm::raw_string_ostream PrefixOStream(tmpBuffer);
4804 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO));
4805 PrefixOStream << CorrectionName;
4806 return PrefixOStream.str();
4809 return CorrectionName.getAsString();
4812 bool CorrectionCandidateCallback::ValidateCandidate(
4813 const TypoCorrection &candidate) {
4814 if (!candidate.isResolved())
4817 if (candidate.isKeyword())
4818 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
4819 WantRemainingKeywords || WantObjCSuper;
4821 bool HasNonType = false;
4822 bool HasStaticMethod = false;
4823 bool HasNonStaticMethod = false;
4824 for (Decl *D : candidate) {
4825 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
4826 D = FTD->getTemplatedDecl();
4827 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
4828 if (Method->isStatic())
4829 HasStaticMethod = true;
4831 HasNonStaticMethod = true;
4833 if (!isa<TypeDecl>(D))
4837 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
4838 !candidate.getCorrectionSpecifier())
4841 return WantTypeSpecifiers || HasNonType;
4844 FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs,
4845 bool HasExplicitTemplateArgs,
4847 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
4848 CurContext(SemaRef.CurContext), MemberFn(ME) {
4849 WantTypeSpecifiers = false;
4850 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && NumArgs == 1;
4851 WantRemainingKeywords = false;
4854 bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) {
4855 if (!candidate.getCorrectionDecl())
4856 return candidate.isKeyword();
4858 for (auto *C : candidate) {
4859 FunctionDecl *FD = nullptr;
4860 NamedDecl *ND = C->getUnderlyingDecl();
4861 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
4862 FD = FTD->getTemplatedDecl();
4863 if (!HasExplicitTemplateArgs && !FD) {
4864 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
4865 // If the Decl is neither a function nor a template function,
4866 // determine if it is a pointer or reference to a function. If so,
4867 // check against the number of arguments expected for the pointee.
4868 QualType ValType = cast<ValueDecl>(ND)->getType();
4869 if (ValType->isAnyPointerType() || ValType->isReferenceType())
4870 ValType = ValType->getPointeeType();
4871 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
4872 if (FPT->getNumParams() == NumArgs)
4877 // Skip the current candidate if it is not a FunctionDecl or does not accept
4878 // the current number of arguments.
4879 if (!FD || !(FD->getNumParams() >= NumArgs &&
4880 FD->getMinRequiredArguments() <= NumArgs))
4883 // If the current candidate is a non-static C++ method, skip the candidate
4884 // unless the method being corrected--or the current DeclContext, if the
4885 // function being corrected is not a method--is a method in the same class
4886 // or a descendent class of the candidate's parent class.
4887 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
4888 if (MemberFn || !MD->isStatic()) {
4889 CXXMethodDecl *CurMD =
4891 ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl())
4892 : dyn_cast_or_null<CXXMethodDecl>(CurContext);
4893 CXXRecordDecl *CurRD =
4894 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
4895 CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
4896 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
4905 void Sema::diagnoseTypo(const TypoCorrection &Correction,
4906 const PartialDiagnostic &TypoDiag,
4907 bool ErrorRecovery) {
4908 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
4912 /// Find which declaration we should import to provide the definition of
4913 /// the given declaration.
4914 static NamedDecl *getDefinitionToImport(NamedDecl *D) {
4915 if (VarDecl *VD = dyn_cast<VarDecl>(D))
4916 return VD->getDefinition();
4917 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
4918 return FD->getDefinition();
4919 if (TagDecl *TD = dyn_cast<TagDecl>(D))
4920 return TD->getDefinition();
4921 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
4922 return ID->getDefinition();
4923 if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
4924 return PD->getDefinition();
4925 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
4926 return getDefinitionToImport(TD->getTemplatedDecl());
4930 void Sema::diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl,
4931 MissingImportKind MIK, bool Recover) {
4932 // Suggest importing a module providing the definition of this entity, if
4934 NamedDecl *Def = getDefinitionToImport(Decl);
4938 Module *Owner = getOwningModule(Decl);
4939 assert(Owner && "definition of hidden declaration is not in a module");
4941 llvm::SmallVector<Module*, 8> OwningModules;
4942 OwningModules.push_back(Owner);
4943 auto Merged = Context.getModulesWithMergedDefinition(Decl);
4944 OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end());
4946 diagnoseMissingImport(Loc, Decl, Decl->getLocation(), OwningModules, MIK,
4950 /// \brief Get a "quoted.h" or <angled.h> include path to use in a diagnostic
4951 /// suggesting the addition of a #include of the specified file.
4952 static std::string getIncludeStringForHeader(Preprocessor &PP,
4953 const FileEntry *E) {
4956 PP.getHeaderSearchInfo().suggestPathToFileForDiagnostics(E, &IsSystem);
4957 return (IsSystem ? '<' : '"') + Path + (IsSystem ? '>' : '"');
4960 void Sema::diagnoseMissingImport(SourceLocation UseLoc, NamedDecl *Decl,
4961 SourceLocation DeclLoc,
4962 ArrayRef<Module *> Modules,
4963 MissingImportKind MIK, bool Recover) {
4964 assert(!Modules.empty());
4966 // Weed out duplicates from module list.
4967 llvm::SmallVector<Module*, 8> UniqueModules;
4968 llvm::SmallDenseSet<Module*, 8> UniqueModuleSet;
4969 for (auto *M : Modules)
4970 if (UniqueModuleSet.insert(M).second)
4971 UniqueModules.push_back(M);
4972 Modules = UniqueModules;
4974 if (Modules.size() > 1) {
4975 std::string ModuleList;
4977 for (Module *M : Modules) {
4978 ModuleList += "\n ";
4979 if (++N == 5 && N != Modules.size()) {
4980 ModuleList += "[...]";
4983 ModuleList += M->getFullModuleName();
4986 Diag(UseLoc, diag::err_module_unimported_use_multiple)
4987 << (int)MIK << Decl << ModuleList;
4988 } else if (const FileEntry *E = PP.getModuleHeaderToIncludeForDiagnostics(
4989 UseLoc, Modules[0], DeclLoc)) {
4990 // The right way to make the declaration visible is to include a header;
4991 // suggest doing so.
4993 // FIXME: Find a smart place to suggest inserting a #include, and add
4994 // a FixItHint there.
4995 Diag(UseLoc, diag::err_module_unimported_use_header)
4996 << (int)MIK << Decl << Modules[0]->getFullModuleName()
4997 << getIncludeStringForHeader(PP, E);
4999 // FIXME: Add a FixItHint that imports the corresponding module.
5000 Diag(UseLoc, diag::err_module_unimported_use)
5001 << (int)MIK << Decl << Modules[0]->getFullModuleName();
5006 case MissingImportKind::Declaration:
5007 DiagID = diag::note_previous_declaration;
5009 case MissingImportKind::Definition:
5010 DiagID = diag::note_previous_definition;
5012 case MissingImportKind::DefaultArgument:
5013 DiagID = diag::note_default_argument_declared_here;
5015 case MissingImportKind::ExplicitSpecialization:
5016 DiagID = diag::note_explicit_specialization_declared_here;
5018 case MissingImportKind::PartialSpecialization:
5019 DiagID = diag::note_partial_specialization_declared_here;
5022 Diag(DeclLoc, DiagID);
5024 // Try to recover by implicitly importing this module.
5026 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5029 /// \brief Diagnose a successfully-corrected typo. Separated from the correction
5030 /// itself to allow external validation of the result, etc.
5032 /// \param Correction The result of performing typo correction.
5033 /// \param TypoDiag The diagnostic to produce. This will have the corrected
5034 /// string added to it (and usually also a fixit).
5035 /// \param PrevNote A note to use when indicating the location of the entity to
5036 /// which we are correcting. Will have the correction string added to it.
5037 /// \param ErrorRecovery If \c true (the default), the caller is going to
5038 /// recover from the typo as if the corrected string had been typed.
5039 /// In this case, \c PDiag must be an error, and we will attach a fixit
5041 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5042 const PartialDiagnostic &TypoDiag,
5043 const PartialDiagnostic &PrevNote,
5044 bool ErrorRecovery) {
5045 std::string CorrectedStr = Correction.getAsString(getLangOpts());
5046 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
5047 FixItHint FixTypo = FixItHint::CreateReplacement(
5048 Correction.getCorrectionRange(), CorrectedStr);
5050 // Maybe we're just missing a module import.
5051 if (Correction.requiresImport()) {
5052 NamedDecl *Decl = Correction.getFoundDecl();
5053 assert(Decl && "import required but no declaration to import");
5055 diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl,
5056 MissingImportKind::Declaration, ErrorRecovery);
5060 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
5061 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
5063 NamedDecl *ChosenDecl =
5064 Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
5065 if (PrevNote.getDiagID() && ChosenDecl)
5066 Diag(ChosenDecl->getLocation(), PrevNote)
5067 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
5069 // Add any extra diagnostics.
5070 for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
5071 Diag(Correction.getCorrectionRange().getBegin(), PD);
5074 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
5075 TypoDiagnosticGenerator TDG,
5076 TypoRecoveryCallback TRC) {
5077 assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer");
5078 auto TE = new (Context) TypoExpr(Context.DependentTy);
5079 auto &State = DelayedTypos[TE];
5080 State.Consumer = std::move(TCC);
5081 State.DiagHandler = std::move(TDG);
5082 State.RecoveryHandler = std::move(TRC);
5086 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const {
5087 auto Entry = DelayedTypos.find(TE);
5088 assert(Entry != DelayedTypos.end() &&
5089 "Failed to get the state for a TypoExpr!");
5090 return Entry->second;
5093 void Sema::clearDelayedTypo(TypoExpr *TE) {
5094 DelayedTypos.erase(TE);
5097 void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) {
5098 DeclarationNameInfo Name(II, IILoc);
5099 LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration);
5100 R.suppressDiagnostics();
5101 R.setHideTags(false);