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 conversion operators, 'operator auto' should only match
866 // 'operator auto'. Since 'auto' is not a type, it shouldn't be considered
867 // as a candidate for template substitution.
868 auto *ContainedDeducedType =
869 R.getLookupName().getCXXNameType()->getContainedDeducedType();
870 if (R.getLookupName().getNameKind() ==
871 DeclarationName::CXXConversionFunctionName &&
872 ContainedDeducedType && ContainedDeducedType->isUndeducedType())
875 for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(),
876 UEnd = Record->conversion_end(); U != UEnd; ++U) {
877 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(*U);
881 // When we're performing lookup for the purposes of redeclaration, just
882 // add the conversion function template. When we deduce template
883 // arguments for specializations, we'll end up unifying the return
884 // type of the new declaration with the type of the function template.
885 if (R.isForRedeclaration()) {
886 R.addDecl(ConvTemplate);
892 // [...] For each such operator, if argument deduction succeeds
893 // (14.9.2.3), the resulting specialization is used as if found by
896 // When referencing a conversion function for any purpose other than
897 // a redeclaration (such that we'll be building an expression with the
898 // result), perform template argument deduction and place the
899 // specialization into the result set. We do this to avoid forcing all
900 // callers to perform special deduction for conversion functions.
901 TemplateDeductionInfo Info(R.getNameLoc());
902 FunctionDecl *Specialization = nullptr;
904 const FunctionProtoType *ConvProto
905 = ConvTemplate->getTemplatedDecl()->getType()->getAs<FunctionProtoType>();
906 assert(ConvProto && "Nonsensical conversion function template type");
908 // Compute the type of the function that we would expect the conversion
909 // function to have, if it were to match the name given.
910 // FIXME: Calling convention!
911 FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo();
912 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C);
913 EPI.ExceptionSpec = EST_None;
914 QualType ExpectedType
915 = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(),
918 // Perform template argument deduction against the type that we would
919 // expect the function to have.
920 if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType,
921 Specialization, Info)
922 == Sema::TDK_Success) {
923 R.addDecl(Specialization);
931 // Performs C++ unqualified lookup into the given file context.
933 CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context,
934 DeclContext *NS, UnqualUsingDirectiveSet &UDirs) {
936 assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!");
938 // Perform direct name lookup into the LookupCtx.
939 bool Found = LookupDirect(S, R, NS);
941 // Perform direct name lookup into the namespaces nominated by the
942 // using directives whose common ancestor is this namespace.
943 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS))
944 if (LookupDirect(S, R, UUE.getNominatedNamespace()))
952 static bool isNamespaceOrTranslationUnitScope(Scope *S) {
953 if (DeclContext *Ctx = S->getEntity())
954 return Ctx->isFileContext();
958 // Find the next outer declaration context from this scope. This
959 // routine actually returns the semantic outer context, which may
960 // differ from the lexical context (encoded directly in the Scope
961 // stack) when we are parsing a member of a class template. In this
962 // case, the second element of the pair will be true, to indicate that
963 // name lookup should continue searching in this semantic context when
964 // it leaves the current template parameter scope.
965 static std::pair<DeclContext *, bool> findOuterContext(Scope *S) {
966 DeclContext *DC = S->getEntity();
967 DeclContext *Lexical = nullptr;
968 for (Scope *OuterS = S->getParent(); OuterS;
969 OuterS = OuterS->getParent()) {
970 if (OuterS->getEntity()) {
971 Lexical = OuterS->getEntity();
976 // C++ [temp.local]p8:
977 // In the definition of a member of a class template that appears
978 // outside of the namespace containing the class template
979 // definition, the name of a template-parameter hides the name of
980 // a member of this namespace.
987 // template<class T> class B {
992 // template<class C> void N::B<C>::f(C) {
993 // C b; // C is the template parameter, not N::C
996 // In this example, the lexical context we return is the
997 // TranslationUnit, while the semantic context is the namespace N.
998 if (!Lexical || !DC || !S->getParent() ||
999 !S->getParent()->isTemplateParamScope())
1000 return std::make_pair(Lexical, false);
1002 // Find the outermost template parameter scope.
1003 // For the example, this is the scope for the template parameters of
1004 // template<class C>.
1005 Scope *OutermostTemplateScope = S->getParent();
1006 while (OutermostTemplateScope->getParent() &&
1007 OutermostTemplateScope->getParent()->isTemplateParamScope())
1008 OutermostTemplateScope = OutermostTemplateScope->getParent();
1010 // Find the namespace context in which the original scope occurs. In
1011 // the example, this is namespace N.
1012 DeclContext *Semantic = DC;
1013 while (!Semantic->isFileContext())
1014 Semantic = Semantic->getParent();
1016 // Find the declaration context just outside of the template
1017 // parameter scope. This is the context in which the template is
1018 // being lexically declaration (a namespace context). In the
1019 // example, this is the global scope.
1020 if (Lexical->isFileContext() && !Lexical->Equals(Semantic) &&
1021 Lexical->Encloses(Semantic))
1022 return std::make_pair(Semantic, true);
1024 return std::make_pair(Lexical, false);
1028 /// An RAII object to specify that we want to find block scope extern
1030 struct FindLocalExternScope {
1031 FindLocalExternScope(LookupResult &R)
1032 : R(R), OldFindLocalExtern(R.getIdentifierNamespace() &
1033 Decl::IDNS_LocalExtern) {
1034 R.setFindLocalExtern(R.getIdentifierNamespace() & Decl::IDNS_Ordinary);
1037 R.setFindLocalExtern(OldFindLocalExtern);
1039 ~FindLocalExternScope() {
1043 bool OldFindLocalExtern;
1045 } // end anonymous namespace
1047 bool Sema::CppLookupName(LookupResult &R, Scope *S) {
1048 assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup");
1050 DeclarationName Name = R.getLookupName();
1051 Sema::LookupNameKind NameKind = R.getLookupKind();
1053 // If this is the name of an implicitly-declared special member function,
1054 // go through the scope stack to implicitly declare
1055 if (isImplicitlyDeclaredMemberFunctionName(Name)) {
1056 for (Scope *PreS = S; PreS; PreS = PreS->getParent())
1057 if (DeclContext *DC = PreS->getEntity())
1058 DeclareImplicitMemberFunctionsWithName(*this, Name, R.getNameLoc(), DC);
1061 // Implicitly declare member functions with the name we're looking for, if in
1062 // fact we are in a scope where it matters.
1065 IdentifierResolver::iterator
1066 I = IdResolver.begin(Name),
1067 IEnd = IdResolver.end();
1069 // First we lookup local scope.
1070 // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir]
1071 // ...During unqualified name lookup (3.4.1), the names appear as if
1072 // they were declared in the nearest enclosing namespace which contains
1073 // both the using-directive and the nominated namespace.
1074 // [Note: in this context, "contains" means "contains directly or
1078 // namespace A { int i; }
1082 // using namespace A;
1083 // ++i; // finds local 'i', A::i appears at global scope
1087 UnqualUsingDirectiveSet UDirs;
1088 bool VisitedUsingDirectives = false;
1089 bool LeftStartingScope = false;
1090 DeclContext *OutsideOfTemplateParamDC = nullptr;
1092 // When performing a scope lookup, we want to find local extern decls.
1093 FindLocalExternScope FindLocals(R);
1095 for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) {
1096 DeclContext *Ctx = S->getEntity();
1097 bool SearchNamespaceScope = true;
1098 // Check whether the IdResolver has anything in this scope.
1099 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1100 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1101 if (NameKind == LookupRedeclarationWithLinkage &&
1102 !(*I)->isTemplateParameter()) {
1103 // If it's a template parameter, we still find it, so we can diagnose
1104 // the invalid redeclaration.
1106 // Determine whether this (or a previous) declaration is
1108 if (!LeftStartingScope && !Initial->isDeclScope(*I))
1109 LeftStartingScope = true;
1111 // If we found something outside of our starting scope that
1112 // does not have linkage, skip it.
1113 if (LeftStartingScope && !((*I)->hasLinkage())) {
1118 // We found something in this scope, we should not look at the
1120 SearchNamespaceScope = false;
1125 if (!SearchNamespaceScope) {
1127 if (S->isClassScope())
1128 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(Ctx))
1129 R.setNamingClass(Record);
1133 if (NameKind == LookupLocalFriendName && !S->isClassScope()) {
1134 // C++11 [class.friend]p11:
1135 // If a friend declaration appears in a local class and the name
1136 // specified is an unqualified name, a prior declaration is
1137 // looked up without considering scopes that are outside the
1138 // innermost enclosing non-class scope.
1142 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1143 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1144 // We've just searched the last template parameter scope and
1145 // found nothing, so look into the contexts between the
1146 // lexical and semantic declaration contexts returned by
1147 // findOuterContext(). This implements the name lookup behavior
1148 // of C++ [temp.local]p8.
1149 Ctx = OutsideOfTemplateParamDC;
1150 OutsideOfTemplateParamDC = nullptr;
1154 DeclContext *OuterCtx;
1155 bool SearchAfterTemplateScope;
1156 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1157 if (SearchAfterTemplateScope)
1158 OutsideOfTemplateParamDC = OuterCtx;
1160 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1161 // We do not directly look into transparent contexts, since
1162 // those entities will be found in the nearest enclosing
1163 // non-transparent context.
1164 if (Ctx->isTransparentContext())
1167 // We do not look directly into function or method contexts,
1168 // since all of the local variables and parameters of the
1169 // function/method are present within the Scope.
1170 if (Ctx->isFunctionOrMethod()) {
1171 // If we have an Objective-C instance method, look for ivars
1172 // in the corresponding interface.
1173 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
1174 if (Method->isInstanceMethod() && Name.getAsIdentifierInfo())
1175 if (ObjCInterfaceDecl *Class = Method->getClassInterface()) {
1176 ObjCInterfaceDecl *ClassDeclared;
1177 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(
1178 Name.getAsIdentifierInfo(),
1180 if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) {
1192 // If this is a file context, we need to perform unqualified name
1193 // lookup considering using directives.
1194 if (Ctx->isFileContext()) {
1195 // If we haven't handled using directives yet, do so now.
1196 if (!VisitedUsingDirectives) {
1197 // Add using directives from this context up to the top level.
1198 for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) {
1199 if (UCtx->isTransparentContext())
1202 UDirs.visit(UCtx, UCtx);
1205 // Find the innermost file scope, so we can add using directives
1206 // from local scopes.
1207 Scope *InnermostFileScope = S;
1208 while (InnermostFileScope &&
1209 !isNamespaceOrTranslationUnitScope(InnermostFileScope))
1210 InnermostFileScope = InnermostFileScope->getParent();
1211 UDirs.visitScopeChain(Initial, InnermostFileScope);
1215 VisitedUsingDirectives = true;
1218 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
1226 // Perform qualified name lookup into this context.
1227 // FIXME: In some cases, we know that every name that could be found by
1228 // this qualified name lookup will also be on the identifier chain. For
1229 // example, inside a class without any base classes, we never need to
1230 // perform qualified lookup because all of the members are on top of the
1231 // identifier chain.
1232 if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true))
1238 // Stop if we ran out of scopes.
1239 // FIXME: This really, really shouldn't be happening.
1240 if (!S) return false;
1242 // If we are looking for members, no need to look into global/namespace scope.
1243 if (NameKind == LookupMemberName)
1246 // Collect UsingDirectiveDecls in all scopes, and recursively all
1247 // nominated namespaces by those using-directives.
1249 // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we
1250 // don't build it for each lookup!
1251 if (!VisitedUsingDirectives) {
1252 UDirs.visitScopeChain(Initial, S);
1256 // If we're not performing redeclaration lookup, do not look for local
1257 // extern declarations outside of a function scope.
1258 if (!R.isForRedeclaration())
1259 FindLocals.restore();
1261 // Lookup namespace scope, and global scope.
1262 // Unqualified name lookup in C++ requires looking into scopes
1263 // that aren't strictly lexical, and therefore we walk through the
1264 // context as well as walking through the scopes.
1265 for (; S; S = S->getParent()) {
1266 // Check whether the IdResolver has anything in this scope.
1268 for (; I != IEnd && S->isDeclScope(*I); ++I) {
1269 if (NamedDecl *ND = R.getAcceptableDecl(*I)) {
1270 // We found something. Look for anything else in our scope
1271 // with this same name and in an acceptable identifier
1272 // namespace, so that we can construct an overload set if we
1279 if (Found && S->isTemplateParamScope()) {
1284 DeclContext *Ctx = S->getEntity();
1285 if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC &&
1286 S->getParent() && !S->getParent()->isTemplateParamScope()) {
1287 // We've just searched the last template parameter scope and
1288 // found nothing, so look into the contexts between the
1289 // lexical and semantic declaration contexts returned by
1290 // findOuterContext(). This implements the name lookup behavior
1291 // of C++ [temp.local]p8.
1292 Ctx = OutsideOfTemplateParamDC;
1293 OutsideOfTemplateParamDC = nullptr;
1297 DeclContext *OuterCtx;
1298 bool SearchAfterTemplateScope;
1299 std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S);
1300 if (SearchAfterTemplateScope)
1301 OutsideOfTemplateParamDC = OuterCtx;
1303 for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) {
1304 // We do not directly look into transparent contexts, since
1305 // those entities will be found in the nearest enclosing
1306 // non-transparent context.
1307 if (Ctx->isTransparentContext())
1310 // If we have a context, and it's not a context stashed in the
1311 // template parameter scope for an out-of-line definition, also
1312 // look into that context.
1313 if (!(Found && S->isTemplateParamScope())) {
1314 assert(Ctx->isFileContext() &&
1315 "We should have been looking only at file context here already.");
1317 // Look into context considering using-directives.
1318 if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs))
1327 if (R.isForRedeclaration() && !Ctx->isTransparentContext())
1332 if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext())
1339 void Sema::makeMergedDefinitionVisible(NamedDecl *ND) {
1340 if (auto *M = getCurrentModule())
1341 Context.mergeDefinitionIntoModule(ND, M);
1343 // We're not building a module; just make the definition visible.
1344 ND->setVisibleDespiteOwningModule();
1346 // If ND is a template declaration, make the template parameters
1347 // visible too. They're not (necessarily) within a mergeable DeclContext.
1348 if (auto *TD = dyn_cast<TemplateDecl>(ND))
1349 for (auto *Param : *TD->getTemplateParameters())
1350 makeMergedDefinitionVisible(Param);
1353 /// \brief Find the module in which the given declaration was defined.
1354 static Module *getDefiningModule(Sema &S, Decl *Entity) {
1355 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Entity)) {
1356 // If this function was instantiated from a template, the defining module is
1357 // the module containing the pattern.
1358 if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
1360 } else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Entity)) {
1361 if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern())
1363 } else if (EnumDecl *ED = dyn_cast<EnumDecl>(Entity)) {
1364 if (auto *Pattern = ED->getTemplateInstantiationPattern())
1366 } else if (VarDecl *VD = dyn_cast<VarDecl>(Entity)) {
1367 if (VarDecl *Pattern = VD->getTemplateInstantiationPattern())
1371 // Walk up to the containing context. That might also have been instantiated
1373 DeclContext *Context = Entity->getDeclContext();
1374 if (Context->isFileContext())
1375 return S.getOwningModule(Entity);
1376 return getDefiningModule(S, cast<Decl>(Context));
1379 llvm::DenseSet<Module*> &Sema::getLookupModules() {
1380 unsigned N = CodeSynthesisContexts.size();
1381 for (unsigned I = CodeSynthesisContextLookupModules.size();
1383 Module *M = getDefiningModule(*this, CodeSynthesisContexts[I].Entity);
1384 if (M && !LookupModulesCache.insert(M).second)
1386 CodeSynthesisContextLookupModules.push_back(M);
1388 return LookupModulesCache;
1391 bool Sema::hasVisibleMergedDefinition(NamedDecl *Def) {
1392 for (Module *Merged : Context.getModulesWithMergedDefinition(Def))
1393 if (isModuleVisible(Merged))
1398 bool Sema::hasMergedDefinitionInCurrentModule(NamedDecl *Def) {
1399 // FIXME: When not in local visibility mode, we can't tell the difference
1400 // between a declaration being visible because we merged a local copy of
1401 // the same declaration into it, and it being visible because its owning
1402 // module is visible.
1403 if (Def->getModuleOwnershipKind() == Decl::ModuleOwnershipKind::Visible &&
1404 getLangOpts().ModulesLocalVisibility)
1406 for (Module *Merged : Context.getModulesWithMergedDefinition(Def))
1407 if (Merged->getTopLevelModuleName() == getLangOpts().CurrentModule)
1412 template<typename ParmDecl>
1414 hasVisibleDefaultArgument(Sema &S, const ParmDecl *D,
1415 llvm::SmallVectorImpl<Module *> *Modules) {
1416 if (!D->hasDefaultArgument())
1420 auto &DefaultArg = D->getDefaultArgStorage();
1421 if (!DefaultArg.isInherited() && S.isVisible(D))
1424 if (!DefaultArg.isInherited() && Modules) {
1425 auto *NonConstD = const_cast<ParmDecl*>(D);
1426 Modules->push_back(S.getOwningModule(NonConstD));
1427 const auto &Merged = S.Context.getModulesWithMergedDefinition(NonConstD);
1428 Modules->insert(Modules->end(), Merged.begin(), Merged.end());
1431 // If there was a previous default argument, maybe its parameter is visible.
1432 D = DefaultArg.getInheritedFrom();
1437 bool Sema::hasVisibleDefaultArgument(const NamedDecl *D,
1438 llvm::SmallVectorImpl<Module *> *Modules) {
1439 if (auto *P = dyn_cast<TemplateTypeParmDecl>(D))
1440 return ::hasVisibleDefaultArgument(*this, P, Modules);
1441 if (auto *P = dyn_cast<NonTypeTemplateParmDecl>(D))
1442 return ::hasVisibleDefaultArgument(*this, P, Modules);
1443 return ::hasVisibleDefaultArgument(*this, cast<TemplateTemplateParmDecl>(D),
1447 template<typename Filter>
1448 static bool hasVisibleDeclarationImpl(Sema &S, const NamedDecl *D,
1449 llvm::SmallVectorImpl<Module *> *Modules,
1451 for (auto *Redecl : D->redecls()) {
1452 auto *R = cast<NamedDecl>(Redecl);
1460 Modules->push_back(R->getOwningModule());
1461 const auto &Merged = S.Context.getModulesWithMergedDefinition(R);
1462 Modules->insert(Modules->end(), Merged.begin(), Merged.end());
1469 bool Sema::hasVisibleExplicitSpecialization(
1470 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1471 return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1472 if (auto *RD = dyn_cast<CXXRecordDecl>(D))
1473 return RD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1474 if (auto *FD = dyn_cast<FunctionDecl>(D))
1475 return FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1476 if (auto *VD = dyn_cast<VarDecl>(D))
1477 return VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization;
1478 llvm_unreachable("unknown explicit specialization kind");
1482 bool Sema::hasVisibleMemberSpecialization(
1483 const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules) {
1484 assert(isa<CXXRecordDecl>(D->getDeclContext()) &&
1485 "not a member specialization");
1486 return hasVisibleDeclarationImpl(*this, D, Modules, [](const NamedDecl *D) {
1487 // If the specialization is declared at namespace scope, then it's a member
1488 // specialization declaration. If it's lexically inside the class
1489 // definition then it was instantiated.
1491 // FIXME: This is a hack. There should be a better way to determine this.
1492 // FIXME: What about MS-style explicit specializations declared within a
1493 // class definition?
1494 return D->getLexicalDeclContext()->isFileContext();
1500 /// \brief Determine whether a declaration is visible to name lookup.
1502 /// This routine determines whether the declaration D is visible in the current
1503 /// lookup context, taking into account the current template instantiation
1504 /// stack. During template instantiation, a declaration is visible if it is
1505 /// visible from a module containing any entity on the template instantiation
1506 /// path (by instantiating a template, you allow it to see the declarations that
1507 /// your module can see, including those later on in your module).
1508 bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
1509 assert(D->isHidden() && "should not call this: not in slow case");
1511 Module *DeclModule = SemaRef.getOwningModule(D);
1513 // A module-private declaration with no owning module means this is in the
1514 // global module in the C++ Modules TS. This is visible within the same
1515 // translation unit only.
1516 // FIXME: Don't assume that "same translation unit" means the same thing
1517 // as "not from an AST file".
1518 assert(D->isModulePrivate() && "hidden decl has no module");
1519 if (!D->isFromASTFile() || SemaRef.hasMergedDefinitionInCurrentModule(D))
1522 // If the owning module is visible, and the decl is not module private,
1523 // then the decl is visible too. (Module private is ignored within the same
1524 // top-level module.)
1525 if (D->isModulePrivate()
1526 ? DeclModule->getTopLevelModuleName() ==
1527 SemaRef.getLangOpts().CurrentModule ||
1528 SemaRef.hasMergedDefinitionInCurrentModule(D)
1529 : SemaRef.isModuleVisible(DeclModule) ||
1530 SemaRef.hasVisibleMergedDefinition(D))
1534 // Determine whether a decl context is a file context for the purpose of
1535 // visibility. This looks through some (export and linkage spec) transparent
1536 // contexts, but not others (enums).
1537 auto IsEffectivelyFileContext = [](const DeclContext *DC) {
1538 return DC->isFileContext() || isa<LinkageSpecDecl>(DC) ||
1539 isa<ExportDecl>(DC);
1542 // If this declaration is not at namespace scope
1543 // then it is visible if its lexical parent has a visible definition.
1544 DeclContext *DC = D->getLexicalDeclContext();
1545 if (DC && !IsEffectivelyFileContext(DC)) {
1546 // For a parameter, check whether our current template declaration's
1547 // lexical context is visible, not whether there's some other visible
1548 // definition of it, because parameters aren't "within" the definition.
1550 // In C++ we need to check for a visible definition due to ODR merging,
1551 // and in C we must not because each declaration of a function gets its own
1552 // set of declarations for tags in prototype scope.
1553 bool VisibleWithinParent;
1554 if (D->isTemplateParameter() || isa<ParmVarDecl>(D) ||
1555 (isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus))
1556 VisibleWithinParent = isVisible(SemaRef, cast<NamedDecl>(DC));
1557 else if (D->isModulePrivate()) {
1558 // A module-private declaration is only visible if an enclosing lexical
1559 // parent was merged with another definition in the current module.
1560 VisibleWithinParent = false;
1562 if (SemaRef.hasMergedDefinitionInCurrentModule(cast<NamedDecl>(DC))) {
1563 VisibleWithinParent = true;
1566 DC = DC->getLexicalParent();
1567 } while (!IsEffectivelyFileContext(DC));
1569 VisibleWithinParent = SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC));
1572 if (VisibleWithinParent && SemaRef.CodeSynthesisContexts.empty() &&
1573 // FIXME: Do something better in this case.
1574 !SemaRef.getLangOpts().ModulesLocalVisibility) {
1575 // Cache the fact that this declaration is implicitly visible because
1576 // its parent has a visible definition.
1577 D->setVisibleDespiteOwningModule();
1579 return VisibleWithinParent;
1582 // FIXME: All uses of DeclModule below this point should also check merged
1587 // Find the extra places where we need to look.
1588 llvm::DenseSet<Module*> &LookupModules = SemaRef.getLookupModules();
1589 if (LookupModules.empty())
1592 // If our lookup set contains the decl's module, it's visible.
1593 if (LookupModules.count(DeclModule))
1596 // If the declaration isn't exported, it's not visible in any other module.
1597 if (D->isModulePrivate())
1600 // Check whether DeclModule is transitively exported to an import of
1602 return std::any_of(LookupModules.begin(), LookupModules.end(),
1603 [&](Module *M) { return M->isModuleVisible(DeclModule); });
1606 bool Sema::isVisibleSlow(const NamedDecl *D) {
1607 return LookupResult::isVisible(*this, const_cast<NamedDecl*>(D));
1610 bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) {
1615 return New->isExternallyVisible();
1618 /// \brief Retrieve the visible declaration corresponding to D, if any.
1620 /// This routine determines whether the declaration D is visible in the current
1621 /// module, with the current imports. If not, it checks whether any
1622 /// redeclaration of D is visible, and if so, returns that declaration.
1624 /// \returns D, or a visible previous declaration of D, whichever is more recent
1625 /// and visible. If no declaration of D is visible, returns null.
1626 static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D) {
1627 assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case");
1629 for (auto RD : D->redecls()) {
1630 // Don't bother with extra checks if we already know this one isn't visible.
1634 auto ND = cast<NamedDecl>(RD);
1635 // FIXME: This is wrong in the case where the previous declaration is not
1636 // visible in the same scope as D. This needs to be done much more
1638 if (LookupResult::isVisible(SemaRef, ND))
1645 bool Sema::hasVisibleDeclarationSlow(const NamedDecl *D,
1646 llvm::SmallVectorImpl<Module *> *Modules) {
1647 assert(!isVisible(D) && "not in slow case");
1648 return hasVisibleDeclarationImpl(*this, D, Modules,
1649 [](const NamedDecl *) { return true; });
1652 NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const {
1653 if (auto *ND = dyn_cast<NamespaceDecl>(D)) {
1654 // Namespaces are a bit of a special case: we expect there to be a lot of
1655 // redeclarations of some namespaces, all declarations of a namespace are
1656 // essentially interchangeable, all declarations are found by name lookup
1657 // if any is, and namespaces are never looked up during template
1658 // instantiation. So we benefit from caching the check in this case, and
1659 // it is correct to do so.
1660 auto *Key = ND->getCanonicalDecl();
1661 if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key))
1664 isVisible(getSema(), Key) ? Key : findAcceptableDecl(getSema(), Key);
1666 getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable));
1670 return findAcceptableDecl(getSema(), D);
1673 /// @brief Perform unqualified name lookup starting from a given
1676 /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is
1677 /// used to find names within the current scope. For example, 'x' in
1681 /// return x; // unqualified name look finds 'x' in the global scope
1685 /// Different lookup criteria can find different names. For example, a
1686 /// particular scope can have both a struct and a function of the same
1687 /// name, and each can be found by certain lookup criteria. For more
1688 /// information about lookup criteria, see the documentation for the
1689 /// class LookupCriteria.
1691 /// @param S The scope from which unqualified name lookup will
1692 /// begin. If the lookup criteria permits, name lookup may also search
1693 /// in the parent scopes.
1695 /// @param [in,out] R Specifies the lookup to perform (e.g., the name to
1696 /// look up and the lookup kind), and is updated with the results of lookup
1697 /// including zero or more declarations and possibly additional information
1698 /// used to diagnose ambiguities.
1700 /// @returns \c true if lookup succeeded and false otherwise.
1701 bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) {
1702 DeclarationName Name = R.getLookupName();
1703 if (!Name) return false;
1705 LookupNameKind NameKind = R.getLookupKind();
1707 if (!getLangOpts().CPlusPlus) {
1708 // Unqualified name lookup in C/Objective-C is purely lexical, so
1709 // search in the declarations attached to the name.
1710 if (NameKind == Sema::LookupRedeclarationWithLinkage) {
1711 // Find the nearest non-transparent declaration scope.
1712 while (!(S->getFlags() & Scope::DeclScope) ||
1713 (S->getEntity() && S->getEntity()->isTransparentContext()))
1717 // When performing a scope lookup, we want to find local extern decls.
1718 FindLocalExternScope FindLocals(R);
1720 // Scan up the scope chain looking for a decl that matches this
1721 // identifier that is in the appropriate namespace. This search
1722 // should not take long, as shadowing of names is uncommon, and
1723 // deep shadowing is extremely uncommon.
1724 bool LeftStartingScope = false;
1726 for (IdentifierResolver::iterator I = IdResolver.begin(Name),
1727 IEnd = IdResolver.end();
1729 if (NamedDecl *D = R.getAcceptableDecl(*I)) {
1730 if (NameKind == LookupRedeclarationWithLinkage) {
1731 // Determine whether this (or a previous) declaration is
1733 if (!LeftStartingScope && !S->isDeclScope(*I))
1734 LeftStartingScope = true;
1736 // If we found something outside of our starting scope that
1737 // does not have linkage, skip it.
1738 if (LeftStartingScope && !((*I)->hasLinkage())) {
1743 else if (NameKind == LookupObjCImplicitSelfParam &&
1744 !isa<ImplicitParamDecl>(*I))
1749 // Check whether there are any other declarations with the same name
1750 // and in the same scope.
1752 // Find the scope in which this declaration was declared (if it
1753 // actually exists in a Scope).
1754 while (S && !S->isDeclScope(D))
1757 // If the scope containing the declaration is the translation unit,
1758 // then we'll need to perform our checks based on the matching
1759 // DeclContexts rather than matching scopes.
1760 if (S && isNamespaceOrTranslationUnitScope(S))
1763 // Compute the DeclContext, if we need it.
1764 DeclContext *DC = nullptr;
1766 DC = (*I)->getDeclContext()->getRedeclContext();
1768 IdentifierResolver::iterator LastI = I;
1769 for (++LastI; LastI != IEnd; ++LastI) {
1771 // Match based on scope.
1772 if (!S->isDeclScope(*LastI))
1775 // Match based on DeclContext.
1777 = (*LastI)->getDeclContext()->getRedeclContext();
1778 if (!LastDC->Equals(DC))
1782 // If the declaration is in the right namespace and visible, add it.
1783 if (NamedDecl *LastD = R.getAcceptableDecl(*LastI))
1793 // Perform C++ unqualified name lookup.
1794 if (CppLookupName(R, S))
1798 // If we didn't find a use of this identifier, and if the identifier
1799 // corresponds to a compiler builtin, create the decl object for the builtin
1800 // now, injecting it into translation unit scope, and return it.
1801 if (AllowBuiltinCreation && LookupBuiltin(*this, R))
1804 // If we didn't find a use of this identifier, the ExternalSource
1805 // may be able to handle the situation.
1806 // Note: some lookup failures are expected!
1807 // See e.g. R.isForRedeclaration().
1808 return (ExternalSource && ExternalSource->LookupUnqualified(R, S));
1811 /// @brief Perform qualified name lookup in the namespaces nominated by
1812 /// using directives by the given context.
1814 /// C++98 [namespace.qual]p2:
1815 /// Given X::m (where X is a user-declared namespace), or given \::m
1816 /// (where X is the global namespace), let S be the set of all
1817 /// declarations of m in X and in the transitive closure of all
1818 /// namespaces nominated by using-directives in X and its used
1819 /// namespaces, except that using-directives are ignored in any
1820 /// namespace, including X, directly containing one or more
1821 /// declarations of m. No namespace is searched more than once in
1822 /// the lookup of a name. If S is the empty set, the program is
1823 /// ill-formed. Otherwise, if S has exactly one member, or if the
1824 /// context of the reference is a using-declaration
1825 /// (namespace.udecl), S is the required set of declarations of
1826 /// m. Otherwise if the use of m is not one that allows a unique
1827 /// declaration to be chosen from S, the program is ill-formed.
1829 /// C++98 [namespace.qual]p5:
1830 /// During the lookup of a qualified namespace member name, if the
1831 /// lookup finds more than one declaration of the member, and if one
1832 /// declaration introduces a class name or enumeration name and the
1833 /// other declarations either introduce the same object, the same
1834 /// enumerator or a set of functions, the non-type name hides the
1835 /// class or enumeration name if and only if the declarations are
1836 /// from the same namespace; otherwise (the declarations are from
1837 /// different namespaces), the program is ill-formed.
1838 static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R,
1839 DeclContext *StartDC) {
1840 assert(StartDC->isFileContext() && "start context is not a file context");
1842 DeclContext::udir_range UsingDirectives = StartDC->using_directives();
1843 if (UsingDirectives.begin() == UsingDirectives.end()) return false;
1845 // We have at least added all these contexts to the queue.
1846 llvm::SmallPtrSet<DeclContext*, 8> Visited;
1847 Visited.insert(StartDC);
1849 // We have not yet looked into these namespaces, much less added
1850 // their "using-children" to the queue.
1851 SmallVector<NamespaceDecl*, 8> Queue;
1853 // We have already looked into the initial namespace; seed the queue
1854 // with its using-children.
1855 for (auto *I : UsingDirectives) {
1856 NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace();
1857 if (Visited.insert(ND).second)
1858 Queue.push_back(ND);
1861 // The easiest way to implement the restriction in [namespace.qual]p5
1862 // is to check whether any of the individual results found a tag
1863 // and, if so, to declare an ambiguity if the final result is not
1865 bool FoundTag = false;
1866 bool FoundNonTag = false;
1868 LookupResult LocalR(LookupResult::Temporary, R);
1871 while (!Queue.empty()) {
1872 NamespaceDecl *ND = Queue.pop_back_val();
1874 // We go through some convolutions here to avoid copying results
1875 // between LookupResults.
1876 bool UseLocal = !R.empty();
1877 LookupResult &DirectR = UseLocal ? LocalR : R;
1878 bool FoundDirect = LookupDirect(S, DirectR, ND);
1881 // First do any local hiding.
1882 DirectR.resolveKind();
1884 // If the local result is a tag, remember that.
1885 if (DirectR.isSingleTagDecl())
1890 // Append the local results to the total results if necessary.
1892 R.addAllDecls(LocalR);
1897 // If we find names in this namespace, ignore its using directives.
1903 for (auto I : ND->using_directives()) {
1904 NamespaceDecl *Nom = I->getNominatedNamespace();
1905 if (Visited.insert(Nom).second)
1906 Queue.push_back(Nom);
1911 if (FoundTag && FoundNonTag)
1912 R.setAmbiguousQualifiedTagHiding();
1920 /// \brief Callback that looks for any member of a class with the given name.
1921 static bool LookupAnyMember(const CXXBaseSpecifier *Specifier,
1922 CXXBasePath &Path, DeclarationName Name) {
1923 RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl();
1925 Path.Decls = BaseRecord->lookup(Name);
1926 return !Path.Decls.empty();
1929 /// \brief Determine whether the given set of member declarations contains only
1930 /// static members, nested types, and enumerators.
1931 template<typename InputIterator>
1932 static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) {
1933 Decl *D = (*First)->getUnderlyingDecl();
1934 if (isa<VarDecl>(D) || isa<TypeDecl>(D) || isa<EnumConstantDecl>(D))
1937 if (isa<CXXMethodDecl>(D)) {
1938 // Determine whether all of the methods are static.
1939 bool AllMethodsAreStatic = true;
1940 for(; First != Last; ++First) {
1941 D = (*First)->getUnderlyingDecl();
1943 if (!isa<CXXMethodDecl>(D)) {
1944 assert(isa<TagDecl>(D) && "Non-function must be a tag decl");
1948 if (!cast<CXXMethodDecl>(D)->isStatic()) {
1949 AllMethodsAreStatic = false;
1954 if (AllMethodsAreStatic)
1961 /// \brief Perform qualified name lookup into a given context.
1963 /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find
1964 /// names when the context of those names is explicit specified, e.g.,
1965 /// "std::vector" or "x->member", or as part of unqualified name lookup.
1967 /// Different lookup criteria can find different names. For example, a
1968 /// particular scope can have both a struct and a function of the same
1969 /// name, and each can be found by certain lookup criteria. For more
1970 /// information about lookup criteria, see the documentation for the
1971 /// class LookupCriteria.
1973 /// \param R captures both the lookup criteria and any lookup results found.
1975 /// \param LookupCtx The context in which qualified name lookup will
1976 /// search. If the lookup criteria permits, name lookup may also search
1977 /// in the parent contexts or (for C++ classes) base classes.
1979 /// \param InUnqualifiedLookup true if this is qualified name lookup that
1980 /// occurs as part of unqualified name lookup.
1982 /// \returns true if lookup succeeded, false if it failed.
1983 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
1984 bool InUnqualifiedLookup) {
1985 assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context");
1987 if (!R.getLookupName())
1990 // Make sure that the declaration context is complete.
1991 assert((!isa<TagDecl>(LookupCtx) ||
1992 LookupCtx->isDependentContext() ||
1993 cast<TagDecl>(LookupCtx)->isCompleteDefinition() ||
1994 cast<TagDecl>(LookupCtx)->isBeingDefined()) &&
1995 "Declaration context must already be complete!");
1997 struct QualifiedLookupInScope {
1999 DeclContext *Context;
2000 // Set flag in DeclContext informing debugger that we're looking for qualified name
2001 QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) {
2002 oldVal = ctx->setUseQualifiedLookup();
2004 ~QualifiedLookupInScope() {
2005 Context->setUseQualifiedLookup(oldVal);
2009 if (LookupDirect(*this, R, LookupCtx)) {
2011 if (isa<CXXRecordDecl>(LookupCtx))
2012 R.setNamingClass(cast<CXXRecordDecl>(LookupCtx));
2016 // Don't descend into implied contexts for redeclarations.
2017 // C++98 [namespace.qual]p6:
2018 // In a declaration for a namespace member in which the
2019 // declarator-id is a qualified-id, given that the qualified-id
2020 // for the namespace member has the form
2021 // nested-name-specifier unqualified-id
2022 // the unqualified-id shall name a member of the namespace
2023 // designated by the nested-name-specifier.
2024 // See also [class.mfct]p5 and [class.static.data]p2.
2025 if (R.isForRedeclaration())
2028 // If this is a namespace, look it up in the implied namespaces.
2029 if (LookupCtx->isFileContext())
2030 return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx);
2032 // If this isn't a C++ class, we aren't allowed to look into base
2033 // classes, we're done.
2034 CXXRecordDecl *LookupRec = dyn_cast<CXXRecordDecl>(LookupCtx);
2035 if (!LookupRec || !LookupRec->getDefinition())
2038 // If we're performing qualified name lookup into a dependent class,
2039 // then we are actually looking into a current instantiation. If we have any
2040 // dependent base classes, then we either have to delay lookup until
2041 // template instantiation time (at which point all bases will be available)
2042 // or we have to fail.
2043 if (!InUnqualifiedLookup && LookupRec->isDependentContext() &&
2044 LookupRec->hasAnyDependentBases()) {
2045 R.setNotFoundInCurrentInstantiation();
2049 // Perform lookup into our base classes.
2051 Paths.setOrigin(LookupRec);
2053 // Look for this member in our base classes
2054 bool (*BaseCallback)(const CXXBaseSpecifier *Specifier, CXXBasePath &Path,
2055 DeclarationName Name) = nullptr;
2056 switch (R.getLookupKind()) {
2057 case LookupObjCImplicitSelfParam:
2058 case LookupOrdinaryName:
2059 case LookupMemberName:
2060 case LookupRedeclarationWithLinkage:
2061 case LookupLocalFriendName:
2062 BaseCallback = &CXXRecordDecl::FindOrdinaryMember;
2066 BaseCallback = &CXXRecordDecl::FindTagMember;
2070 BaseCallback = &LookupAnyMember;
2073 case LookupOMPReductionName:
2074 BaseCallback = &CXXRecordDecl::FindOMPReductionMember;
2077 case LookupUsingDeclName:
2078 // This lookup is for redeclarations only.
2080 case LookupOperatorName:
2081 case LookupNamespaceName:
2082 case LookupObjCProtocolName:
2084 // These lookups will never find a member in a C++ class (or base class).
2087 case LookupNestedNameSpecifierName:
2088 BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember;
2092 DeclarationName Name = R.getLookupName();
2093 if (!LookupRec->lookupInBases(
2094 [=](const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
2095 return BaseCallback(Specifier, Path, Name);
2100 R.setNamingClass(LookupRec);
2102 // C++ [class.member.lookup]p2:
2103 // [...] If the resulting set of declarations are not all from
2104 // sub-objects of the same type, or the set has a nonstatic member
2105 // and includes members from distinct sub-objects, there is an
2106 // ambiguity and the program is ill-formed. Otherwise that set is
2107 // the result of the lookup.
2108 QualType SubobjectType;
2109 int SubobjectNumber = 0;
2110 AccessSpecifier SubobjectAccess = AS_none;
2112 for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end();
2113 Path != PathEnd; ++Path) {
2114 const CXXBasePathElement &PathElement = Path->back();
2116 // Pick the best (i.e. most permissive i.e. numerically lowest) access
2117 // across all paths.
2118 SubobjectAccess = std::min(SubobjectAccess, Path->Access);
2120 // Determine whether we're looking at a distinct sub-object or not.
2121 if (SubobjectType.isNull()) {
2122 // This is the first subobject we've looked at. Record its type.
2123 SubobjectType = Context.getCanonicalType(PathElement.Base->getType());
2124 SubobjectNumber = PathElement.SubobjectNumber;
2129 != Context.getCanonicalType(PathElement.Base->getType())) {
2130 // We found members of the given name in two subobjects of
2131 // different types. If the declaration sets aren't the same, this
2132 // lookup is ambiguous.
2133 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) {
2134 CXXBasePaths::paths_iterator FirstPath = Paths.begin();
2135 DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin();
2136 DeclContext::lookup_iterator CurrentD = Path->Decls.begin();
2138 while (FirstD != FirstPath->Decls.end() &&
2139 CurrentD != Path->Decls.end()) {
2140 if ((*FirstD)->getUnderlyingDecl()->getCanonicalDecl() !=
2141 (*CurrentD)->getUnderlyingDecl()->getCanonicalDecl())
2148 if (FirstD == FirstPath->Decls.end() &&
2149 CurrentD == Path->Decls.end())
2153 R.setAmbiguousBaseSubobjectTypes(Paths);
2157 if (SubobjectNumber != PathElement.SubobjectNumber) {
2158 // We have a different subobject of the same type.
2160 // C++ [class.member.lookup]p5:
2161 // A static member, a nested type or an enumerator defined in
2162 // a base class T can unambiguously be found even if an object
2163 // has more than one base class subobject of type T.
2164 if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end()))
2167 // We have found a nonstatic member name in multiple, distinct
2168 // subobjects. Name lookup is ambiguous.
2169 R.setAmbiguousBaseSubobjects(Paths);
2174 // Lookup in a base class succeeded; return these results.
2176 for (auto *D : Paths.front().Decls) {
2177 AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess,
2185 /// \brief Performs qualified name lookup or special type of lookup for
2186 /// "__super::" scope specifier.
2188 /// This routine is a convenience overload meant to be called from contexts
2189 /// that need to perform a qualified name lookup with an optional C++ scope
2190 /// specifier that might require special kind of lookup.
2192 /// \param R captures both the lookup criteria and any lookup results found.
2194 /// \param LookupCtx The context in which qualified name lookup will
2197 /// \param SS An optional C++ scope-specifier.
2199 /// \returns true if lookup succeeded, false if it failed.
2200 bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
2202 auto *NNS = SS.getScopeRep();
2203 if (NNS && NNS->getKind() == NestedNameSpecifier::Super)
2204 return LookupInSuper(R, NNS->getAsRecordDecl());
2207 return LookupQualifiedName(R, LookupCtx);
2210 /// @brief Performs name lookup for a name that was parsed in the
2211 /// source code, and may contain a C++ scope specifier.
2213 /// This routine is a convenience routine meant to be called from
2214 /// contexts that receive a name and an optional C++ scope specifier
2215 /// (e.g., "N::M::x"). It will then perform either qualified or
2216 /// unqualified name lookup (with LookupQualifiedName or LookupName,
2217 /// respectively) on the given name and return those results. It will
2218 /// perform a special type of lookup for "__super::" scope specifier.
2220 /// @param S The scope from which unqualified name lookup will
2223 /// @param SS An optional C++ scope-specifier, e.g., "::N::M".
2225 /// @param EnteringContext Indicates whether we are going to enter the
2226 /// context of the scope-specifier SS (if present).
2228 /// @returns True if any decls were found (but possibly ambiguous)
2229 bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
2230 bool AllowBuiltinCreation, bool EnteringContext) {
2231 if (SS && SS->isInvalid()) {
2232 // When the scope specifier is invalid, don't even look for
2237 if (SS && SS->isSet()) {
2238 NestedNameSpecifier *NNS = SS->getScopeRep();
2239 if (NNS->getKind() == NestedNameSpecifier::Super)
2240 return LookupInSuper(R, NNS->getAsRecordDecl());
2242 if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) {
2243 // We have resolved the scope specifier to a particular declaration
2244 // contex, and will perform name lookup in that context.
2245 if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC))
2248 R.setContextRange(SS->getRange());
2249 return LookupQualifiedName(R, DC);
2252 // We could not resolve the scope specified to a specific declaration
2253 // context, which means that SS refers to an unknown specialization.
2254 // Name lookup can't find anything in this case.
2255 R.setNotFoundInCurrentInstantiation();
2256 R.setContextRange(SS->getRange());
2260 // Perform unqualified name lookup starting in the given scope.
2261 return LookupName(R, S, AllowBuiltinCreation);
2264 /// \brief Perform qualified name lookup into all base classes of the given
2267 /// \param R captures both the lookup criteria and any lookup results found.
2269 /// \param Class The context in which qualified name lookup will
2270 /// search. Name lookup will search in all base classes merging the results.
2272 /// @returns True if any decls were found (but possibly ambiguous)
2273 bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) {
2274 // The access-control rules we use here are essentially the rules for
2275 // doing a lookup in Class that just magically skipped the direct
2276 // members of Class itself. That is, the naming class is Class, and the
2277 // access includes the access of the base.
2278 for (const auto &BaseSpec : Class->bases()) {
2279 CXXRecordDecl *RD = cast<CXXRecordDecl>(
2280 BaseSpec.getType()->castAs<RecordType>()->getDecl());
2281 LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind());
2282 Result.setBaseObjectType(Context.getRecordType(Class));
2283 LookupQualifiedName(Result, RD);
2285 // Copy the lookup results into the target, merging the base's access into
2287 for (auto I = Result.begin(), E = Result.end(); I != E; ++I) {
2288 R.addDecl(I.getDecl(),
2289 CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(),
2293 Result.suppressDiagnostics();
2297 R.setNamingClass(Class);
2302 /// \brief Produce a diagnostic describing the ambiguity that resulted
2303 /// from name lookup.
2305 /// \param Result The result of the ambiguous lookup to be diagnosed.
2306 void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) {
2307 assert(Result.isAmbiguous() && "Lookup result must be ambiguous");
2309 DeclarationName Name = Result.getLookupName();
2310 SourceLocation NameLoc = Result.getNameLoc();
2311 SourceRange LookupRange = Result.getContextRange();
2313 switch (Result.getAmbiguityKind()) {
2314 case LookupResult::AmbiguousBaseSubobjects: {
2315 CXXBasePaths *Paths = Result.getBasePaths();
2316 QualType SubobjectType = Paths->front().back().Base->getType();
2317 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects)
2318 << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths)
2321 DeclContext::lookup_iterator Found = Paths->front().Decls.begin();
2322 while (isa<CXXMethodDecl>(*Found) &&
2323 cast<CXXMethodDecl>(*Found)->isStatic())
2326 Diag((*Found)->getLocation(), diag::note_ambiguous_member_found);
2330 case LookupResult::AmbiguousBaseSubobjectTypes: {
2331 Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types)
2332 << Name << LookupRange;
2334 CXXBasePaths *Paths = Result.getBasePaths();
2335 std::set<Decl *> DeclsPrinted;
2336 for (CXXBasePaths::paths_iterator Path = Paths->begin(),
2337 PathEnd = Paths->end();
2338 Path != PathEnd; ++Path) {
2339 Decl *D = Path->Decls.front();
2340 if (DeclsPrinted.insert(D).second)
2341 Diag(D->getLocation(), diag::note_ambiguous_member_found);
2346 case LookupResult::AmbiguousTagHiding: {
2347 Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange;
2349 llvm::SmallPtrSet<NamedDecl*, 8> TagDecls;
2351 for (auto *D : Result)
2352 if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
2353 TagDecls.insert(TD);
2354 Diag(TD->getLocation(), diag::note_hidden_tag);
2357 for (auto *D : Result)
2358 if (!isa<TagDecl>(D))
2359 Diag(D->getLocation(), diag::note_hiding_object);
2361 // For recovery purposes, go ahead and implement the hiding.
2362 LookupResult::Filter F = Result.makeFilter();
2363 while (F.hasNext()) {
2364 if (TagDecls.count(F.next()))
2371 case LookupResult::AmbiguousReference: {
2372 Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange;
2374 for (auto *D : Result)
2375 Diag(D->getLocation(), diag::note_ambiguous_candidate) << D;
2382 struct AssociatedLookup {
2383 AssociatedLookup(Sema &S, SourceLocation InstantiationLoc,
2384 Sema::AssociatedNamespaceSet &Namespaces,
2385 Sema::AssociatedClassSet &Classes)
2386 : S(S), Namespaces(Namespaces), Classes(Classes),
2387 InstantiationLoc(InstantiationLoc) {
2391 Sema::AssociatedNamespaceSet &Namespaces;
2392 Sema::AssociatedClassSet &Classes;
2393 SourceLocation InstantiationLoc;
2395 } // end anonymous namespace
2398 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T);
2400 static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces,
2402 // Add the associated namespace for this class.
2404 // We don't use DeclContext::getEnclosingNamespaceContext() as this may
2405 // be a locally scoped record.
2407 // We skip out of inline namespaces. The innermost non-inline namespace
2408 // contains all names of all its nested inline namespaces anyway, so we can
2409 // replace the entire inline namespace tree with its root.
2410 while (Ctx->isRecord() || Ctx->isTransparentContext() ||
2411 Ctx->isInlineNamespace())
2412 Ctx = Ctx->getParent();
2414 if (Ctx->isFileContext())
2415 Namespaces.insert(Ctx->getPrimaryContext());
2418 // \brief Add the associated classes and namespaces for argument-dependent
2419 // lookup that involves a template argument (C++ [basic.lookup.koenig]p2).
2421 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2422 const TemplateArgument &Arg) {
2423 // C++ [basic.lookup.koenig]p2, last bullet:
2425 switch (Arg.getKind()) {
2426 case TemplateArgument::Null:
2429 case TemplateArgument::Type:
2430 // [...] the namespaces and classes associated with the types of the
2431 // template arguments provided for template type parameters (excluding
2432 // template template parameters)
2433 addAssociatedClassesAndNamespaces(Result, Arg.getAsType());
2436 case TemplateArgument::Template:
2437 case TemplateArgument::TemplateExpansion: {
2438 // [...] the namespaces in which any template template arguments are
2439 // defined; and the classes in which any member templates used as
2440 // template template arguments are defined.
2441 TemplateName Template = Arg.getAsTemplateOrTemplatePattern();
2442 if (ClassTemplateDecl *ClassTemplate
2443 = dyn_cast<ClassTemplateDecl>(Template.getAsTemplateDecl())) {
2444 DeclContext *Ctx = ClassTemplate->getDeclContext();
2445 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2446 Result.Classes.insert(EnclosingClass);
2447 // Add the associated namespace for this class.
2448 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2453 case TemplateArgument::Declaration:
2454 case TemplateArgument::Integral:
2455 case TemplateArgument::Expression:
2456 case TemplateArgument::NullPtr:
2457 // [Note: non-type template arguments do not contribute to the set of
2458 // associated namespaces. ]
2461 case TemplateArgument::Pack:
2462 for (const auto &P : Arg.pack_elements())
2463 addAssociatedClassesAndNamespaces(Result, P);
2468 // \brief Add the associated classes and namespaces for
2469 // argument-dependent lookup with an argument of class type
2470 // (C++ [basic.lookup.koenig]p2).
2472 addAssociatedClassesAndNamespaces(AssociatedLookup &Result,
2473 CXXRecordDecl *Class) {
2475 // Just silently ignore anything whose name is __va_list_tag.
2476 if (Class->getDeclName() == Result.S.VAListTagName)
2479 // C++ [basic.lookup.koenig]p2:
2481 // -- If T is a class type (including unions), its associated
2482 // classes are: the class itself; the class of which it is a
2483 // member, if any; and its direct and indirect base
2484 // classes. Its associated namespaces are the namespaces in
2485 // which its associated classes are defined.
2487 // Add the class of which it is a member, if any.
2488 DeclContext *Ctx = Class->getDeclContext();
2489 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2490 Result.Classes.insert(EnclosingClass);
2491 // Add the associated namespace for this class.
2492 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2494 // Add the class itself. If we've already seen this class, we don't
2495 // need to visit base classes.
2497 // FIXME: That's not correct, we may have added this class only because it
2498 // was the enclosing class of another class, and in that case we won't have
2499 // added its base classes yet.
2500 if (!Result.Classes.insert(Class))
2503 // -- If T is a template-id, its associated namespaces and classes are
2504 // the namespace in which the template is defined; for member
2505 // templates, the member template's class; the namespaces and classes
2506 // associated with the types of the template arguments provided for
2507 // template type parameters (excluding template template parameters); the
2508 // namespaces in which any template template arguments are defined; and
2509 // the classes in which any member templates used as template template
2510 // arguments are defined. [Note: non-type template arguments do not
2511 // contribute to the set of associated namespaces. ]
2512 if (ClassTemplateSpecializationDecl *Spec
2513 = dyn_cast<ClassTemplateSpecializationDecl>(Class)) {
2514 DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext();
2515 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2516 Result.Classes.insert(EnclosingClass);
2517 // Add the associated namespace for this class.
2518 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2520 const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
2521 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
2522 addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]);
2525 // Only recurse into base classes for complete types.
2526 if (!Result.S.isCompleteType(Result.InstantiationLoc,
2527 Result.S.Context.getRecordType(Class)))
2530 // Add direct and indirect base classes along with their associated
2532 SmallVector<CXXRecordDecl *, 32> Bases;
2533 Bases.push_back(Class);
2534 while (!Bases.empty()) {
2535 // Pop this class off the stack.
2536 Class = Bases.pop_back_val();
2538 // Visit the base classes.
2539 for (const auto &Base : Class->bases()) {
2540 const RecordType *BaseType = Base.getType()->getAs<RecordType>();
2541 // In dependent contexts, we do ADL twice, and the first time around,
2542 // the base type might be a dependent TemplateSpecializationType, or a
2543 // TemplateTypeParmType. If that happens, simply ignore it.
2544 // FIXME: If we want to support export, we probably need to add the
2545 // namespace of the template in a TemplateSpecializationType, or even
2546 // the classes and namespaces of known non-dependent arguments.
2549 CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(BaseType->getDecl());
2550 if (Result.Classes.insert(BaseDecl)) {
2551 // Find the associated namespace for this base class.
2552 DeclContext *BaseCtx = BaseDecl->getDeclContext();
2553 CollectEnclosingNamespace(Result.Namespaces, BaseCtx);
2555 // Make sure we visit the bases of this base class.
2556 if (BaseDecl->bases_begin() != BaseDecl->bases_end())
2557 Bases.push_back(BaseDecl);
2563 // \brief Add the associated classes and namespaces for
2564 // argument-dependent lookup with an argument of type T
2565 // (C++ [basic.lookup.koenig]p2).
2567 addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) {
2568 // C++ [basic.lookup.koenig]p2:
2570 // For each argument type T in the function call, there is a set
2571 // of zero or more associated namespaces and a set of zero or more
2572 // associated classes to be considered. The sets of namespaces and
2573 // classes is determined entirely by the types of the function
2574 // arguments (and the namespace of any template template
2575 // argument). Typedef names and using-declarations used to specify
2576 // the types do not contribute to this set. The sets of namespaces
2577 // and classes are determined in the following way:
2579 SmallVector<const Type *, 16> Queue;
2580 const Type *T = Ty->getCanonicalTypeInternal().getTypePtr();
2583 switch (T->getTypeClass()) {
2585 #define TYPE(Class, Base)
2586 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
2587 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
2588 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
2589 #define ABSTRACT_TYPE(Class, Base)
2590 #include "clang/AST/TypeNodes.def"
2591 // T is canonical. We can also ignore dependent types because
2592 // we don't need to do ADL at the definition point, but if we
2593 // wanted to implement template export (or if we find some other
2594 // use for associated classes and namespaces...) this would be
2598 // -- If T is a pointer to U or an array of U, its associated
2599 // namespaces and classes are those associated with U.
2601 T = cast<PointerType>(T)->getPointeeType().getTypePtr();
2603 case Type::ConstantArray:
2604 case Type::IncompleteArray:
2605 case Type::VariableArray:
2606 T = cast<ArrayType>(T)->getElementType().getTypePtr();
2609 // -- If T is a fundamental type, its associated sets of
2610 // namespaces and classes are both empty.
2614 // -- If T is a class type (including unions), its associated
2615 // classes are: the class itself; the class of which it is a
2616 // member, if any; and its direct and indirect base
2617 // classes. Its associated namespaces are the namespaces in
2618 // which its associated classes are defined.
2619 case Type::Record: {
2620 CXXRecordDecl *Class =
2621 cast<CXXRecordDecl>(cast<RecordType>(T)->getDecl());
2622 addAssociatedClassesAndNamespaces(Result, Class);
2626 // -- If T is an enumeration type, its associated namespace is
2627 // the namespace in which it is defined. If it is class
2628 // member, its associated class is the member's class; else
2629 // it has no associated class.
2631 EnumDecl *Enum = cast<EnumType>(T)->getDecl();
2633 DeclContext *Ctx = Enum->getDeclContext();
2634 if (CXXRecordDecl *EnclosingClass = dyn_cast<CXXRecordDecl>(Ctx))
2635 Result.Classes.insert(EnclosingClass);
2637 // Add the associated namespace for this class.
2638 CollectEnclosingNamespace(Result.Namespaces, Ctx);
2643 // -- If T is a function type, its associated namespaces and
2644 // classes are those associated with the function parameter
2645 // types and those associated with the return type.
2646 case Type::FunctionProto: {
2647 const FunctionProtoType *Proto = cast<FunctionProtoType>(T);
2648 for (const auto &Arg : Proto->param_types())
2649 Queue.push_back(Arg.getTypePtr());
2653 case Type::FunctionNoProto: {
2654 const FunctionType *FnType = cast<FunctionType>(T);
2655 T = FnType->getReturnType().getTypePtr();
2659 // -- If T is a pointer to a member function of a class X, its
2660 // associated namespaces and classes are those associated
2661 // with the function parameter types and return type,
2662 // together with those associated with X.
2664 // -- If T is a pointer to a data member of class X, its
2665 // associated namespaces and classes are those associated
2666 // with the member type together with those associated with
2668 case Type::MemberPointer: {
2669 const MemberPointerType *MemberPtr = cast<MemberPointerType>(T);
2671 // Queue up the class type into which this points.
2672 Queue.push_back(MemberPtr->getClass());
2674 // And directly continue with the pointee type.
2675 T = MemberPtr->getPointeeType().getTypePtr();
2679 // As an extension, treat this like a normal pointer.
2680 case Type::BlockPointer:
2681 T = cast<BlockPointerType>(T)->getPointeeType().getTypePtr();
2684 // References aren't covered by the standard, but that's such an
2685 // obvious defect that we cover them anyway.
2686 case Type::LValueReference:
2687 case Type::RValueReference:
2688 T = cast<ReferenceType>(T)->getPointeeType().getTypePtr();
2691 // These are fundamental types.
2693 case Type::ExtVector:
2697 // Non-deduced auto types only get here for error cases.
2699 case Type::DeducedTemplateSpecialization:
2702 // If T is an Objective-C object or interface type, or a pointer to an
2703 // object or interface type, the associated namespace is the global
2705 case Type::ObjCObject:
2706 case Type::ObjCInterface:
2707 case Type::ObjCObjectPointer:
2708 Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl());
2711 // Atomic types are just wrappers; use the associations of the
2714 T = cast<AtomicType>(T)->getValueType().getTypePtr();
2717 T = cast<PipeType>(T)->getElementType().getTypePtr();
2723 T = Queue.pop_back_val();
2727 /// \brief Find the associated classes and namespaces for
2728 /// argument-dependent lookup for a call with the given set of
2731 /// This routine computes the sets of associated classes and associated
2732 /// namespaces searched by argument-dependent lookup
2733 /// (C++ [basic.lookup.argdep]) for a given set of arguments.
2734 void Sema::FindAssociatedClassesAndNamespaces(
2735 SourceLocation InstantiationLoc, ArrayRef<Expr *> Args,
2736 AssociatedNamespaceSet &AssociatedNamespaces,
2737 AssociatedClassSet &AssociatedClasses) {
2738 AssociatedNamespaces.clear();
2739 AssociatedClasses.clear();
2741 AssociatedLookup Result(*this, InstantiationLoc,
2742 AssociatedNamespaces, AssociatedClasses);
2744 // C++ [basic.lookup.koenig]p2:
2745 // For each argument type T in the function call, there is a set
2746 // of zero or more associated namespaces and a set of zero or more
2747 // associated classes to be considered. The sets of namespaces and
2748 // classes is determined entirely by the types of the function
2749 // arguments (and the namespace of any template template
2751 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) {
2752 Expr *Arg = Args[ArgIdx];
2754 if (Arg->getType() != Context.OverloadTy) {
2755 addAssociatedClassesAndNamespaces(Result, Arg->getType());
2759 // [...] In addition, if the argument is the name or address of a
2760 // set of overloaded functions and/or function templates, its
2761 // associated classes and namespaces are the union of those
2762 // associated with each of the members of the set: the namespace
2763 // in which the function or function template is defined and the
2764 // classes and namespaces associated with its (non-dependent)
2765 // parameter types and return type.
2766 Arg = Arg->IgnoreParens();
2767 if (UnaryOperator *unaryOp = dyn_cast<UnaryOperator>(Arg))
2768 if (unaryOp->getOpcode() == UO_AddrOf)
2769 Arg = unaryOp->getSubExpr();
2771 UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(Arg);
2774 for (const auto *D : ULE->decls()) {
2775 // Look through any using declarations to find the underlying function.
2776 const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction();
2778 // Add the classes and namespaces associated with the parameter
2779 // types and return type of this function.
2780 addAssociatedClassesAndNamespaces(Result, FDecl->getType());
2785 NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name,
2787 LookupNameKind NameKind,
2788 RedeclarationKind Redecl) {
2789 LookupResult R(*this, Name, Loc, NameKind, Redecl);
2791 return R.getAsSingle<NamedDecl>();
2794 /// \brief Find the protocol with the given name, if any.
2795 ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II,
2796 SourceLocation IdLoc,
2797 RedeclarationKind Redecl) {
2798 Decl *D = LookupSingleName(TUScope, II, IdLoc,
2799 LookupObjCProtocolName, Redecl);
2800 return cast_or_null<ObjCProtocolDecl>(D);
2803 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
2804 QualType T1, QualType T2,
2805 UnresolvedSetImpl &Functions) {
2806 // C++ [over.match.oper]p3:
2807 // -- The set of non-member candidates is the result of the
2808 // unqualified lookup of operator@ in the context of the
2809 // expression according to the usual rules for name lookup in
2810 // unqualified function calls (3.4.2) except that all member
2811 // functions are ignored.
2812 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op);
2813 LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName);
2814 LookupName(Operators, S);
2816 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous");
2817 Functions.append(Operators.begin(), Operators.end());
2820 Sema::SpecialMemberOverloadResult Sema::LookupSpecialMember(CXXRecordDecl *RD,
2821 CXXSpecialMember SM,
2826 bool VolatileThis) {
2827 assert(CanDeclareSpecialMemberFunction(RD) &&
2828 "doing special member lookup into record that isn't fully complete");
2829 RD = RD->getDefinition();
2830 if (RValueThis || ConstThis || VolatileThis)
2831 assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) &&
2832 "constructors and destructors always have unqualified lvalue this");
2833 if (ConstArg || VolatileArg)
2834 assert((SM != CXXDefaultConstructor && SM != CXXDestructor) &&
2835 "parameter-less special members can't have qualified arguments");
2837 // FIXME: Get the caller to pass in a location for the lookup.
2838 SourceLocation LookupLoc = RD->getLocation();
2840 llvm::FoldingSetNodeID ID;
2843 ID.AddInteger(ConstArg);
2844 ID.AddInteger(VolatileArg);
2845 ID.AddInteger(RValueThis);
2846 ID.AddInteger(ConstThis);
2847 ID.AddInteger(VolatileThis);
2850 SpecialMemberOverloadResultEntry *Result =
2851 SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint);
2853 // This was already cached
2857 Result = BumpAlloc.Allocate<SpecialMemberOverloadResultEntry>();
2858 Result = new (Result) SpecialMemberOverloadResultEntry(ID);
2859 SpecialMemberCache.InsertNode(Result, InsertPoint);
2861 if (SM == CXXDestructor) {
2862 if (RD->needsImplicitDestructor())
2863 DeclareImplicitDestructor(RD);
2864 CXXDestructorDecl *DD = RD->getDestructor();
2865 assert(DD && "record without a destructor");
2866 Result->setMethod(DD);
2867 Result->setKind(DD->isDeleted() ?
2868 SpecialMemberOverloadResult::NoMemberOrDeleted :
2869 SpecialMemberOverloadResult::Success);
2873 // Prepare for overload resolution. Here we construct a synthetic argument
2874 // if necessary and make sure that implicit functions are declared.
2875 CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD));
2876 DeclarationName Name;
2877 Expr *Arg = nullptr;
2880 QualType ArgType = CanTy;
2881 ExprValueKind VK = VK_LValue;
2883 if (SM == CXXDefaultConstructor) {
2884 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2886 if (RD->needsImplicitDefaultConstructor())
2887 DeclareImplicitDefaultConstructor(RD);
2889 if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) {
2890 Name = Context.DeclarationNames.getCXXConstructorName(CanTy);
2891 if (RD->needsImplicitCopyConstructor())
2892 DeclareImplicitCopyConstructor(RD);
2893 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor())
2894 DeclareImplicitMoveConstructor(RD);
2896 Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
2897 if (RD->needsImplicitCopyAssignment())
2898 DeclareImplicitCopyAssignment(RD);
2899 if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment())
2900 DeclareImplicitMoveAssignment(RD);
2906 ArgType.addVolatile();
2908 // This isn't /really/ specified by the standard, but it's implied
2909 // we should be working from an RValue in the case of move to ensure
2910 // that we prefer to bind to rvalue references, and an LValue in the
2911 // case of copy to ensure we don't bind to rvalue references.
2912 // Possibly an XValue is actually correct in the case of move, but
2913 // there is no semantic difference for class types in this restricted
2915 if (SM == CXXCopyConstructor || SM == CXXCopyAssignment)
2921 OpaqueValueExpr FakeArg(LookupLoc, ArgType, VK);
2923 if (SM != CXXDefaultConstructor) {
2928 // Create the object argument
2929 QualType ThisTy = CanTy;
2933 ThisTy.addVolatile();
2934 Expr::Classification Classification =
2935 OpaqueValueExpr(LookupLoc, ThisTy,
2936 RValueThis ? VK_RValue : VK_LValue).Classify(Context);
2938 // Now we perform lookup on the name we computed earlier and do overload
2939 // resolution. Lookup is only performed directly into the class since there
2940 // will always be a (possibly implicit) declaration to shadow any others.
2941 OverloadCandidateSet OCS(LookupLoc, OverloadCandidateSet::CSK_Normal);
2942 DeclContext::lookup_result R = RD->lookup(Name);
2945 // We might have no default constructor because we have a lambda's closure
2946 // type, rather than because there's some other declared constructor.
2947 // Every class has a copy/move constructor, copy/move assignment, and
2949 assert(SM == CXXDefaultConstructor &&
2950 "lookup for a constructor or assignment operator was empty");
2951 Result->setMethod(nullptr);
2952 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
2956 // Copy the candidates as our processing of them may load new declarations
2957 // from an external source and invalidate lookup_result.
2958 SmallVector<NamedDecl *, 8> Candidates(R.begin(), R.end());
2960 for (NamedDecl *CandDecl : Candidates) {
2961 if (CandDecl->isInvalidDecl())
2964 DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public);
2965 auto CtorInfo = getConstructorInfo(Cand);
2966 if (CXXMethodDecl *M = dyn_cast<CXXMethodDecl>(Cand->getUnderlyingDecl())) {
2967 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2968 AddMethodCandidate(M, Cand, RD, ThisTy, Classification,
2969 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2971 AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl,
2972 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2974 AddOverloadCandidate(M, Cand, llvm::makeArrayRef(&Arg, NumArgs), OCS,
2976 } else if (FunctionTemplateDecl *Tmpl =
2977 dyn_cast<FunctionTemplateDecl>(Cand->getUnderlyingDecl())) {
2978 if (SM == CXXCopyAssignment || SM == CXXMoveAssignment)
2979 AddMethodTemplateCandidate(
2980 Tmpl, Cand, RD, nullptr, ThisTy, Classification,
2981 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2983 AddTemplateOverloadCandidate(
2984 CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr,
2985 llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2987 AddTemplateOverloadCandidate(
2988 Tmpl, Cand, nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true);
2990 assert(isa<UsingDecl>(Cand.getDecl()) &&
2991 "illegal Kind of operator = Decl");
2995 OverloadCandidateSet::iterator Best;
2996 switch (OCS.BestViableFunction(*this, LookupLoc, Best)) {
2998 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
2999 Result->setKind(SpecialMemberOverloadResult::Success);
3003 Result->setMethod(cast<CXXMethodDecl>(Best->Function));
3004 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3008 Result->setMethod(nullptr);
3009 Result->setKind(SpecialMemberOverloadResult::Ambiguous);
3012 case OR_No_Viable_Function:
3013 Result->setMethod(nullptr);
3014 Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted);
3021 /// \brief Look up the default constructor for the given class.
3022 CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) {
3023 SpecialMemberOverloadResult Result =
3024 LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false,
3027 return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3030 /// \brief Look up the copying constructor for the given class.
3031 CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class,
3033 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3034 "non-const, non-volatile qualifiers for copy ctor arg");
3035 SpecialMemberOverloadResult Result =
3036 LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const,
3037 Quals & Qualifiers::Volatile, false, false, false);
3039 return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3042 /// \brief Look up the moving constructor for the given class.
3043 CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class,
3045 SpecialMemberOverloadResult Result =
3046 LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const,
3047 Quals & Qualifiers::Volatile, false, false, false);
3049 return cast_or_null<CXXConstructorDecl>(Result.getMethod());
3052 /// \brief Look up the constructors for the given class.
3053 DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) {
3054 // If the implicit constructors have not yet been declared, do so now.
3055 if (CanDeclareSpecialMemberFunction(Class)) {
3056 if (Class->needsImplicitDefaultConstructor())
3057 DeclareImplicitDefaultConstructor(Class);
3058 if (Class->needsImplicitCopyConstructor())
3059 DeclareImplicitCopyConstructor(Class);
3060 if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor())
3061 DeclareImplicitMoveConstructor(Class);
3064 CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class));
3065 DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T);
3066 return Class->lookup(Name);
3069 /// \brief Look up the copying assignment operator for the given class.
3070 CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class,
3071 unsigned Quals, bool RValueThis,
3072 unsigned ThisQuals) {
3073 assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3074 "non-const, non-volatile qualifiers for copy assignment arg");
3075 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3076 "non-const, non-volatile qualifiers for copy assignment this");
3077 SpecialMemberOverloadResult Result =
3078 LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const,
3079 Quals & Qualifiers::Volatile, RValueThis,
3080 ThisQuals & Qualifiers::Const,
3081 ThisQuals & Qualifiers::Volatile);
3083 return Result.getMethod();
3086 /// \brief Look up the moving assignment operator for the given class.
3087 CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class,
3090 unsigned ThisQuals) {
3091 assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) &&
3092 "non-const, non-volatile qualifiers for copy assignment this");
3093 SpecialMemberOverloadResult Result =
3094 LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const,
3095 Quals & Qualifiers::Volatile, RValueThis,
3096 ThisQuals & Qualifiers::Const,
3097 ThisQuals & Qualifiers::Volatile);
3099 return Result.getMethod();
3102 /// \brief Look for the destructor of the given class.
3104 /// During semantic analysis, this routine should be used in lieu of
3105 /// CXXRecordDecl::getDestructor().
3107 /// \returns The destructor for this class.
3108 CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) {
3109 return cast<CXXDestructorDecl>(LookupSpecialMember(Class, CXXDestructor,
3110 false, false, false,
3111 false, false).getMethod());
3114 /// LookupLiteralOperator - Determine which literal operator should be used for
3115 /// a user-defined literal, per C++11 [lex.ext].
3117 /// Normal overload resolution is not used to select which literal operator to
3118 /// call for a user-defined literal. Look up the provided literal operator name,
3119 /// and filter the results to the appropriate set for the given argument types.
3120 Sema::LiteralOperatorLookupResult
3121 Sema::LookupLiteralOperator(Scope *S, LookupResult &R,
3122 ArrayRef<QualType> ArgTys,
3123 bool AllowRaw, bool AllowTemplate,
3124 bool AllowStringTemplate) {
3126 assert(R.getResultKind() != LookupResult::Ambiguous &&
3127 "literal operator lookup can't be ambiguous");
3129 // Filter the lookup results appropriately.
3130 LookupResult::Filter F = R.makeFilter();
3132 bool FoundRaw = false;
3133 bool FoundTemplate = false;
3134 bool FoundStringTemplate = false;
3135 bool FoundExactMatch = false;
3137 while (F.hasNext()) {
3139 if (UsingShadowDecl *USD = dyn_cast<UsingShadowDecl>(D))
3140 D = USD->getTargetDecl();
3142 // If the declaration we found is invalid, skip it.
3143 if (D->isInvalidDecl()) {
3149 bool IsTemplate = false;
3150 bool IsStringTemplate = false;
3151 bool IsExactMatch = false;
3153 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
3154 if (FD->getNumParams() == 1 &&
3155 FD->getParamDecl(0)->getType()->getAs<PointerType>())
3157 else if (FD->getNumParams() == ArgTys.size()) {
3158 IsExactMatch = true;
3159 for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) {
3160 QualType ParamTy = FD->getParamDecl(ArgIdx)->getType();
3161 if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) {
3162 IsExactMatch = false;
3168 if (FunctionTemplateDecl *FD = dyn_cast<FunctionTemplateDecl>(D)) {
3169 TemplateParameterList *Params = FD->getTemplateParameters();
3170 if (Params->size() == 1)
3173 IsStringTemplate = true;
3177 FoundExactMatch = true;
3179 AllowTemplate = false;
3180 AllowStringTemplate = false;
3181 if (FoundRaw || FoundTemplate || FoundStringTemplate) {
3182 // Go through again and remove the raw and template decls we've
3185 FoundRaw = FoundTemplate = FoundStringTemplate = false;
3187 } else if (AllowRaw && IsRaw) {
3189 } else if (AllowTemplate && IsTemplate) {
3190 FoundTemplate = true;
3191 } else if (AllowStringTemplate && IsStringTemplate) {
3192 FoundStringTemplate = true;
3200 // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching
3201 // parameter type, that is used in preference to a raw literal operator
3202 // or literal operator template.
3203 if (FoundExactMatch)
3206 // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal
3207 // operator template, but not both.
3208 if (FoundRaw && FoundTemplate) {
3209 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName();
3210 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
3211 NoteOverloadCandidate(*I, (*I)->getUnderlyingDecl()->getAsFunction());
3219 return LOLR_Template;
3221 if (FoundStringTemplate)
3222 return LOLR_StringTemplate;
3224 // Didn't find anything we could use.
3225 Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator)
3226 << R.getLookupName() << (int)ArgTys.size() << ArgTys[0]
3227 << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw
3228 << (AllowTemplate || AllowStringTemplate);
3232 void ADLResult::insert(NamedDecl *New) {
3233 NamedDecl *&Old = Decls[cast<NamedDecl>(New->getCanonicalDecl())];
3235 // If we haven't yet seen a decl for this key, or the last decl
3236 // was exactly this one, we're done.
3237 if (Old == nullptr || Old == New) {
3242 // Otherwise, decide which is a more recent redeclaration.
3243 FunctionDecl *OldFD = Old->getAsFunction();
3244 FunctionDecl *NewFD = New->getAsFunction();
3246 FunctionDecl *Cursor = NewFD;
3248 Cursor = Cursor->getPreviousDecl();
3250 // If we got to the end without finding OldFD, OldFD is the newer
3251 // declaration; leave things as they are.
3252 if (!Cursor) return;
3254 // If we do find OldFD, then NewFD is newer.
3255 if (Cursor == OldFD) break;
3257 // Otherwise, keep looking.
3263 void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
3264 ArrayRef<Expr *> Args, ADLResult &Result) {
3265 // Find all of the associated namespaces and classes based on the
3266 // arguments we have.
3267 AssociatedNamespaceSet AssociatedNamespaces;
3268 AssociatedClassSet AssociatedClasses;
3269 FindAssociatedClassesAndNamespaces(Loc, Args,
3270 AssociatedNamespaces,
3273 // C++ [basic.lookup.argdep]p3:
3274 // Let X be the lookup set produced by unqualified lookup (3.4.1)
3275 // and let Y be the lookup set produced by argument dependent
3276 // lookup (defined as follows). If X contains [...] then Y is
3277 // empty. Otherwise Y is the set of declarations found in the
3278 // namespaces associated with the argument types as described
3279 // below. The set of declarations found by the lookup of the name
3280 // is the union of X and Y.
3282 // Here, we compute Y and add its members to the overloaded
3284 for (auto *NS : AssociatedNamespaces) {
3285 // When considering an associated namespace, the lookup is the
3286 // same as the lookup performed when the associated namespace is
3287 // used as a qualifier (3.4.3.2) except that:
3289 // -- Any using-directives in the associated namespace are
3292 // -- Any namespace-scope friend functions declared in
3293 // associated classes are visible within their respective
3294 // namespaces even if they are not visible during an ordinary
3296 DeclContext::lookup_result R = NS->lookup(Name);
3298 // If the only declaration here is an ordinary friend, consider
3299 // it only if it was declared in an associated classes.
3300 if ((D->getIdentifierNamespace() & Decl::IDNS_Ordinary) == 0) {
3301 // If it's neither ordinarily visible nor a friend, we can't find it.
3302 if ((D->getIdentifierNamespace() & Decl::IDNS_OrdinaryFriend) == 0)
3305 bool DeclaredInAssociatedClass = false;
3306 for (Decl *DI = D; DI; DI = DI->getPreviousDecl()) {
3307 DeclContext *LexDC = DI->getLexicalDeclContext();
3308 if (isa<CXXRecordDecl>(LexDC) &&
3309 AssociatedClasses.count(cast<CXXRecordDecl>(LexDC)) &&
3310 isVisible(cast<NamedDecl>(DI))) {
3311 DeclaredInAssociatedClass = true;
3315 if (!DeclaredInAssociatedClass)
3319 if (isa<UsingShadowDecl>(D))
3320 D = cast<UsingShadowDecl>(D)->getTargetDecl();
3322 if (!isa<FunctionDecl>(D) && !isa<FunctionTemplateDecl>(D))
3325 if (!isVisible(D) && !(D = findAcceptableDecl(*this, D)))
3333 //----------------------------------------------------------------------------
3334 // Search for all visible declarations.
3335 //----------------------------------------------------------------------------
3336 VisibleDeclConsumer::~VisibleDeclConsumer() { }
3338 bool VisibleDeclConsumer::includeHiddenDecls() const { return false; }
3342 class ShadowContextRAII;
3344 class VisibleDeclsRecord {
3346 /// \brief An entry in the shadow map, which is optimized to store a
3347 /// single declaration (the common case) but can also store a list
3348 /// of declarations.
3349 typedef llvm::TinyPtrVector<NamedDecl*> ShadowMapEntry;
3352 /// \brief A mapping from declaration names to the declarations that have
3353 /// this name within a particular scope.
3354 typedef llvm::DenseMap<DeclarationName, ShadowMapEntry> ShadowMap;
3356 /// \brief A list of shadow maps, which is used to model name hiding.
3357 std::list<ShadowMap> ShadowMaps;
3359 /// \brief The declaration contexts we have already visited.
3360 llvm::SmallPtrSet<DeclContext *, 8> VisitedContexts;
3362 friend class ShadowContextRAII;
3365 /// \brief Determine whether we have already visited this context
3366 /// (and, if not, note that we are going to visit that context now).
3367 bool visitedContext(DeclContext *Ctx) {
3368 return !VisitedContexts.insert(Ctx).second;
3371 bool alreadyVisitedContext(DeclContext *Ctx) {
3372 return VisitedContexts.count(Ctx);
3375 /// \brief Determine whether the given declaration is hidden in the
3378 /// \returns the declaration that hides the given declaration, or
3379 /// NULL if no such declaration exists.
3380 NamedDecl *checkHidden(NamedDecl *ND);
3382 /// \brief Add a declaration to the current shadow map.
3383 void add(NamedDecl *ND) {
3384 ShadowMaps.back()[ND->getDeclName()].push_back(ND);
3388 /// \brief RAII object that records when we've entered a shadow context.
3389 class ShadowContextRAII {
3390 VisibleDeclsRecord &Visible;
3392 typedef VisibleDeclsRecord::ShadowMap ShadowMap;
3395 ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) {
3396 Visible.ShadowMaps.emplace_back();
3399 ~ShadowContextRAII() {
3400 Visible.ShadowMaps.pop_back();
3404 } // end anonymous namespace
3406 NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) {
3407 unsigned IDNS = ND->getIdentifierNamespace();
3408 std::list<ShadowMap>::reverse_iterator SM = ShadowMaps.rbegin();
3409 for (std::list<ShadowMap>::reverse_iterator SMEnd = ShadowMaps.rend();
3410 SM != SMEnd; ++SM) {
3411 ShadowMap::iterator Pos = SM->find(ND->getDeclName());
3412 if (Pos == SM->end())
3415 for (auto *D : Pos->second) {
3416 // A tag declaration does not hide a non-tag declaration.
3417 if (D->hasTagIdentifierNamespace() &&
3418 (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary |
3419 Decl::IDNS_ObjCProtocol)))
3422 // Protocols are in distinct namespaces from everything else.
3423 if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol)
3424 || (IDNS & Decl::IDNS_ObjCProtocol)) &&
3425 D->getIdentifierNamespace() != IDNS)
3428 // Functions and function templates in the same scope overload
3429 // rather than hide. FIXME: Look for hiding based on function
3431 if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3432 ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() &&
3433 SM == ShadowMaps.rbegin())
3436 // A shadow declaration that's created by a resolved using declaration
3437 // is not hidden by the same using declaration.
3438 if (isa<UsingShadowDecl>(ND) && isa<UsingDecl>(D) &&
3439 cast<UsingShadowDecl>(ND)->getUsingDecl() == D)
3442 // We've found a declaration that hides this one.
3450 static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
3451 bool QualifiedNameLookup,
3453 VisibleDeclConsumer &Consumer,
3454 VisibleDeclsRecord &Visited,
3455 bool IncludeDependentBases = false) {
3459 // Make sure we don't visit the same context twice.
3460 if (Visited.visitedContext(Ctx->getPrimaryContext()))
3463 // Outside C++, lookup results for the TU live on identifiers.
3464 if (isa<TranslationUnitDecl>(Ctx) &&
3465 !Result.getSema().getLangOpts().CPlusPlus) {
3466 auto &S = Result.getSema();
3467 auto &Idents = S.Context.Idents;
3469 // Ensure all external identifiers are in the identifier table.
3470 if (IdentifierInfoLookup *External = Idents.getExternalIdentifierLookup()) {
3471 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
3472 for (StringRef Name = Iter->Next(); !Name.empty(); Name = Iter->Next())
3476 // Walk all lookup results in the TU for each identifier.
3477 for (const auto &Ident : Idents) {
3478 for (auto I = S.IdResolver.begin(Ident.getValue()),
3479 E = S.IdResolver.end();
3481 if (S.IdResolver.isDeclInScope(*I, Ctx)) {
3482 if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
3483 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3493 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
3494 Result.getSema().ForceDeclarationOfImplicitMembers(Class);
3496 // Enumerate all of the results in this context.
3497 for (DeclContextLookupResult R : Ctx->lookups()) {
3499 if (auto *ND = Result.getAcceptableDecl(D)) {
3500 Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
3506 // Traverse using directives for qualified name lookup.
3507 if (QualifiedNameLookup) {
3508 ShadowContextRAII Shadow(Visited);
3509 for (auto I : Ctx->using_directives()) {
3510 LookupVisibleDecls(I->getNominatedNamespace(), Result,
3511 QualifiedNameLookup, InBaseClass, Consumer, Visited,
3512 IncludeDependentBases);
3516 // Traverse the contexts of inherited C++ classes.
3517 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) {
3518 if (!Record->hasDefinition())
3521 for (const auto &B : Record->bases()) {
3522 QualType BaseType = B.getType();
3525 if (BaseType->isDependentType()) {
3526 if (!IncludeDependentBases) {
3527 // Don't look into dependent bases, because name lookup can't look
3531 const auto *TST = BaseType->getAs<TemplateSpecializationType>();
3534 TemplateName TN = TST->getTemplateName();
3536 dyn_cast_or_null<ClassTemplateDecl>(TN.getAsTemplateDecl());
3539 RD = TD->getTemplatedDecl();
3541 const auto *Record = BaseType->getAs<RecordType>();
3544 RD = Record->getDecl();
3547 // FIXME: It would be nice to be able to determine whether referencing
3548 // a particular member would be ambiguous. For example, given
3550 // struct A { int member; };
3551 // struct B { int member; };
3552 // struct C : A, B { };
3554 // void f(C *c) { c->### }
3556 // accessing 'member' would result in an ambiguity. However, we
3557 // could be smart enough to qualify the member with the base
3566 // Find results in this base class (and its bases).
3567 ShadowContextRAII Shadow(Visited);
3568 LookupVisibleDecls(RD, Result, QualifiedNameLookup, true, Consumer,
3569 Visited, IncludeDependentBases);
3573 // Traverse the contexts of Objective-C classes.
3574 if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
3575 // Traverse categories.
3576 for (auto *Cat : IFace->visible_categories()) {
3577 ShadowContextRAII Shadow(Visited);
3578 LookupVisibleDecls(Cat, Result, QualifiedNameLookup, false,
3582 // Traverse protocols.
3583 for (auto *I : IFace->all_referenced_protocols()) {
3584 ShadowContextRAII Shadow(Visited);
3585 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3589 // Traverse the superclass.
3590 if (IFace->getSuperClass()) {
3591 ShadowContextRAII Shadow(Visited);
3592 LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup,
3593 true, Consumer, Visited);
3596 // If there is an implementation, traverse it. We do this to find
3597 // synthesized ivars.
3598 if (IFace->getImplementation()) {
3599 ShadowContextRAII Shadow(Visited);
3600 LookupVisibleDecls(IFace->getImplementation(), Result,
3601 QualifiedNameLookup, InBaseClass, Consumer, Visited);
3603 } else if (ObjCProtocolDecl *Protocol = dyn_cast<ObjCProtocolDecl>(Ctx)) {
3604 for (auto *I : Protocol->protocols()) {
3605 ShadowContextRAII Shadow(Visited);
3606 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3609 } else if (ObjCCategoryDecl *Category = dyn_cast<ObjCCategoryDecl>(Ctx)) {
3610 for (auto *I : Category->protocols()) {
3611 ShadowContextRAII Shadow(Visited);
3612 LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer,
3616 // If there is an implementation, traverse it.
3617 if (Category->getImplementation()) {
3618 ShadowContextRAII Shadow(Visited);
3619 LookupVisibleDecls(Category->getImplementation(), Result,
3620 QualifiedNameLookup, true, Consumer, Visited);
3625 static void LookupVisibleDecls(Scope *S, LookupResult &Result,
3626 UnqualUsingDirectiveSet &UDirs,
3627 VisibleDeclConsumer &Consumer,
3628 VisibleDeclsRecord &Visited) {
3632 if (!S->getEntity() ||
3634 !Visited.alreadyVisitedContext(S->getEntity())) ||
3635 (S->getEntity())->isFunctionOrMethod()) {
3636 FindLocalExternScope FindLocals(Result);
3637 // Walk through the declarations in this Scope.
3638 for (auto *D : S->decls()) {
3639 if (NamedDecl *ND = dyn_cast<NamedDecl>(D))
3640 if ((ND = Result.getAcceptableDecl(ND))) {
3641 Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false);
3647 // FIXME: C++ [temp.local]p8
3648 DeclContext *Entity = nullptr;
3649 if (S->getEntity()) {
3650 // Look into this scope's declaration context, along with any of its
3651 // parent lookup contexts (e.g., enclosing classes), up to the point
3652 // where we hit the context stored in the next outer scope.
3653 Entity = S->getEntity();
3654 DeclContext *OuterCtx = findOuterContext(S).first; // FIXME
3656 for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx);
3657 Ctx = Ctx->getLookupParent()) {
3658 if (ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(Ctx)) {
3659 if (Method->isInstanceMethod()) {
3660 // For instance methods, look for ivars in the method's interface.
3661 LookupResult IvarResult(Result.getSema(), Result.getLookupName(),
3662 Result.getNameLoc(), Sema::LookupMemberName);
3663 if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) {
3664 LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false,
3665 /*InBaseClass=*/false, Consumer, Visited);
3669 // We've already performed all of the name lookup that we need
3670 // to for Objective-C methods; the next context will be the
3675 if (Ctx->isFunctionOrMethod())
3678 LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false,
3679 /*InBaseClass=*/false, Consumer, Visited);
3681 } else if (!S->getParent()) {
3682 // Look into the translation unit scope. We walk through the translation
3683 // unit's declaration context, because the Scope itself won't have all of
3684 // the declarations if we loaded a precompiled header.
3685 // FIXME: We would like the translation unit's Scope object to point to the
3686 // translation unit, so we don't need this special "if" branch. However,
3687 // doing so would force the normal C++ name-lookup code to look into the
3688 // translation unit decl when the IdentifierInfo chains would suffice.
3689 // Once we fix that problem (which is part of a more general "don't look
3690 // in DeclContexts unless we have to" optimization), we can eliminate this.
3691 Entity = Result.getSema().Context.getTranslationUnitDecl();
3692 LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false,
3693 /*InBaseClass=*/false, Consumer, Visited);
3697 // Lookup visible declarations in any namespaces found by using
3699 for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity))
3700 LookupVisibleDecls(const_cast<DeclContext *>(UUE.getNominatedNamespace()),
3701 Result, /*QualifiedNameLookup=*/false,
3702 /*InBaseClass=*/false, Consumer, Visited);
3705 // Lookup names in the parent scope.
3706 ShadowContextRAII Shadow(Visited);
3707 LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited);
3710 void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind,
3711 VisibleDeclConsumer &Consumer,
3712 bool IncludeGlobalScope) {
3713 // Determine the set of using directives available during
3714 // unqualified name lookup.
3716 UnqualUsingDirectiveSet UDirs;
3717 if (getLangOpts().CPlusPlus) {
3718 // Find the first namespace or translation-unit scope.
3719 while (S && !isNamespaceOrTranslationUnitScope(S))
3722 UDirs.visitScopeChain(Initial, S);
3726 // Look for visible declarations.
3727 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3728 Result.setAllowHidden(Consumer.includeHiddenDecls());
3729 VisibleDeclsRecord Visited;
3730 if (!IncludeGlobalScope)
3731 Visited.visitedContext(Context.getTranslationUnitDecl());
3732 ShadowContextRAII Shadow(Visited);
3733 ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited);
3736 void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
3737 VisibleDeclConsumer &Consumer,
3738 bool IncludeGlobalScope,
3739 bool IncludeDependentBases) {
3740 LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind);
3741 Result.setAllowHidden(Consumer.includeHiddenDecls());
3742 VisibleDeclsRecord Visited;
3743 if (!IncludeGlobalScope)
3744 Visited.visitedContext(Context.getTranslationUnitDecl());
3745 ShadowContextRAII Shadow(Visited);
3746 ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true,
3747 /*InBaseClass=*/false, Consumer, Visited,
3748 IncludeDependentBases);
3751 /// LookupOrCreateLabel - Do a name lookup of a label with the specified name.
3752 /// If GnuLabelLoc is a valid source location, then this is a definition
3753 /// of an __label__ label name, otherwise it is a normal label definition
3755 LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc,
3756 SourceLocation GnuLabelLoc) {
3757 // Do a lookup to see if we have a label with this name already.
3758 NamedDecl *Res = nullptr;
3760 if (GnuLabelLoc.isValid()) {
3761 // Local label definitions always shadow existing labels.
3762 Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc);
3763 Scope *S = CurScope;
3764 PushOnScopeChains(Res, S, true);
3765 return cast<LabelDecl>(Res);
3768 // Not a GNU local label.
3769 Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration);
3770 // If we found a label, check to see if it is in the same context as us.
3771 // When in a Block, we don't want to reuse a label in an enclosing function.
3772 if (Res && Res->getDeclContext() != CurContext)
3775 // If not forward referenced or defined already, create the backing decl.
3776 Res = LabelDecl::Create(Context, CurContext, Loc, II);
3777 Scope *S = CurScope->getFnParent();
3778 assert(S && "Not in a function?");
3779 PushOnScopeChains(Res, S, true);
3781 return cast<LabelDecl>(Res);
3784 //===----------------------------------------------------------------------===//
3786 //===----------------------------------------------------------------------===//
3788 static bool isCandidateViable(CorrectionCandidateCallback &CCC,
3789 TypoCorrection &Candidate) {
3790 Candidate.setCallbackDistance(CCC.RankCandidate(Candidate));
3791 return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance;
3794 static void LookupPotentialTypoResult(Sema &SemaRef,
3796 IdentifierInfo *Name,
3797 Scope *S, CXXScopeSpec *SS,
3798 DeclContext *MemberContext,
3799 bool EnteringContext,
3800 bool isObjCIvarLookup,
3803 /// \brief Check whether the declarations found for a typo correction are
3804 /// visible. Set the correction's RequiresImport flag to true if none of the
3805 /// declarations are visible, false otherwise.
3806 static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) {
3807 TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end();
3809 for (/**/; DI != DE; ++DI)
3810 if (!LookupResult::isVisible(SemaRef, *DI))
3812 // No filtering needed if all decls are visible.
3814 TC.setRequiresImport(false);
3818 llvm::SmallVector<NamedDecl*, 4> NewDecls(TC.begin(), DI);
3819 bool AnyVisibleDecls = !NewDecls.empty();
3821 for (/**/; DI != DE; ++DI) {
3822 NamedDecl *VisibleDecl = *DI;
3823 if (!LookupResult::isVisible(SemaRef, *DI))
3824 VisibleDecl = findAcceptableDecl(SemaRef, *DI);
3827 if (!AnyVisibleDecls) {
3828 // Found a visible decl, discard all hidden ones.
3829 AnyVisibleDecls = true;
3832 NewDecls.push_back(VisibleDecl);
3833 } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate())
3834 NewDecls.push_back(*DI);
3837 if (NewDecls.empty())
3838 TC = TypoCorrection();
3840 TC.setCorrectionDecls(NewDecls);
3841 TC.setRequiresImport(!AnyVisibleDecls);
3845 // Fill the supplied vector with the IdentifierInfo pointers for each piece of
3846 // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::",
3847 // fill the vector with the IdentifierInfo pointers for "foo" and "bar").
3848 static void getNestedNameSpecifierIdentifiers(
3849 NestedNameSpecifier *NNS,
3850 SmallVectorImpl<const IdentifierInfo*> &Identifiers) {
3851 if (NestedNameSpecifier *Prefix = NNS->getPrefix())
3852 getNestedNameSpecifierIdentifiers(Prefix, Identifiers);
3854 Identifiers.clear();
3856 const IdentifierInfo *II = nullptr;
3858 switch (NNS->getKind()) {
3859 case NestedNameSpecifier::Identifier:
3860 II = NNS->getAsIdentifier();
3863 case NestedNameSpecifier::Namespace:
3864 if (NNS->getAsNamespace()->isAnonymousNamespace())
3866 II = NNS->getAsNamespace()->getIdentifier();
3869 case NestedNameSpecifier::NamespaceAlias:
3870 II = NNS->getAsNamespaceAlias()->getIdentifier();
3873 case NestedNameSpecifier::TypeSpecWithTemplate:
3874 case NestedNameSpecifier::TypeSpec:
3875 II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier();
3878 case NestedNameSpecifier::Global:
3879 case NestedNameSpecifier::Super:
3884 Identifiers.push_back(II);
3887 void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding,
3888 DeclContext *Ctx, bool InBaseClass) {
3889 // Don't consider hidden names for typo correction.
3893 // Only consider entities with identifiers for names, ignoring
3894 // special names (constructors, overloaded operators, selectors,
3896 IdentifierInfo *Name = ND->getIdentifier();
3900 // Only consider visible declarations and declarations from modules with
3901 // names that exactly match.
3902 if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo &&
3903 !findAcceptableDecl(SemaRef, ND))
3906 FoundName(Name->getName());
3909 void TypoCorrectionConsumer::FoundName(StringRef Name) {
3910 // Compute the edit distance between the typo and the name of this
3911 // entity, and add the identifier to the list of results.
3912 addName(Name, nullptr);
3915 void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) {
3916 // Compute the edit distance between the typo and this keyword,
3917 // and add the keyword to the list of results.
3918 addName(Keyword, nullptr, nullptr, true);
3921 void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND,
3922 NestedNameSpecifier *NNS, bool isKeyword) {
3923 // Use a simple length-based heuristic to determine the minimum possible
3924 // edit distance. If the minimum isn't good enough, bail out early.
3925 StringRef TypoStr = Typo->getName();
3926 unsigned MinED = abs((int)Name.size() - (int)TypoStr.size());
3927 if (MinED && TypoStr.size() / MinED < 3)
3930 // Compute an upper bound on the allowable edit distance, so that the
3931 // edit-distance algorithm can short-circuit.
3932 unsigned UpperBound = (TypoStr.size() + 2) / 3 + 1;
3933 unsigned ED = TypoStr.edit_distance(Name, true, UpperBound);
3934 if (ED >= UpperBound) return;
3936 TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED);
3937 if (isKeyword) TC.makeKeyword();
3938 TC.setCorrectionRange(nullptr, Result.getLookupNameInfo());
3942 static const unsigned MaxTypoDistanceResultSets = 5;
3944 void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) {
3945 StringRef TypoStr = Typo->getName();
3946 StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName();
3948 // For very short typos, ignore potential corrections that have a different
3949 // base identifier from the typo or which have a normalized edit distance
3950 // longer than the typo itself.
3951 if (TypoStr.size() < 3 &&
3952 (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size()))
3955 // If the correction is resolved but is not viable, ignore it.
3956 if (Correction.isResolved()) {
3957 checkCorrectionVisibility(SemaRef, Correction);
3958 if (!Correction || !isCandidateViable(*CorrectionValidator, Correction))
3962 TypoResultList &CList =
3963 CorrectionResults[Correction.getEditDistance(false)][Name];
3965 if (!CList.empty() && !CList.back().isResolved())
3967 if (NamedDecl *NewND = Correction.getCorrectionDecl()) {
3968 std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts());
3969 for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end();
3970 RI != RIEnd; ++RI) {
3971 // If the Correction refers to a decl already in the result list,
3972 // replace the existing result if the string representation of Correction
3973 // comes before the current result alphabetically, then stop as there is
3974 // nothing more to be done to add Correction to the candidate set.
3975 if (RI->getCorrectionDecl() == NewND) {
3976 if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts()))
3982 if (CList.empty() || Correction.isResolved())
3983 CList.push_back(Correction);
3985 while (CorrectionResults.size() > MaxTypoDistanceResultSets)
3986 CorrectionResults.erase(std::prev(CorrectionResults.end()));
3989 void TypoCorrectionConsumer::addNamespaces(
3990 const llvm::MapVector<NamespaceDecl *, bool> &KnownNamespaces) {
3991 SearchNamespaces = true;
3993 for (auto KNPair : KnownNamespaces)
3994 Namespaces.addNameSpecifier(KNPair.first);
3996 bool SSIsTemplate = false;
3997 if (NestedNameSpecifier *NNS =
3998 (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) {
3999 if (const Type *T = NNS->getAsType())
4000 SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization;
4002 // Do not transform this into an iterator-based loop. The loop body can
4003 // trigger the creation of further types (through lazy deserialization) and
4004 // invalide iterators into this list.
4005 auto &Types = SemaRef.getASTContext().getTypes();
4006 for (unsigned I = 0; I != Types.size(); ++I) {
4007 const auto *TI = Types[I];
4008 if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) {
4009 CD = CD->getCanonicalDecl();
4010 if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() &&
4011 !CD->isUnion() && CD->getIdentifier() &&
4012 (SSIsTemplate || !isa<ClassTemplateSpecializationDecl>(CD)) &&
4013 (CD->isBeingDefined() || CD->isCompleteDefinition()))
4014 Namespaces.addNameSpecifier(CD);
4019 const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() {
4020 if (++CurrentTCIndex < ValidatedCorrections.size())
4021 return ValidatedCorrections[CurrentTCIndex];
4023 CurrentTCIndex = ValidatedCorrections.size();
4024 while (!CorrectionResults.empty()) {
4025 auto DI = CorrectionResults.begin();
4026 if (DI->second.empty()) {
4027 CorrectionResults.erase(DI);
4031 auto RI = DI->second.begin();
4032 if (RI->second.empty()) {
4033 DI->second.erase(RI);
4034 performQualifiedLookups();
4038 TypoCorrection TC = RI->second.pop_back_val();
4039 if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) {
4040 ValidatedCorrections.push_back(TC);
4041 return ValidatedCorrections[CurrentTCIndex];
4044 return ValidatedCorrections[0]; // The empty correction.
4047 bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) {
4048 IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo();
4049 DeclContext *TempMemberContext = MemberContext;
4050 CXXScopeSpec *TempSS = SS.get();
4052 LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext,
4054 CorrectionValidator->IsObjCIvarLookup,
4055 Name == Typo && !Candidate.WillReplaceSpecifier());
4056 switch (Result.getResultKind()) {
4057 case LookupResult::NotFound:
4058 case LookupResult::NotFoundInCurrentInstantiation:
4059 case LookupResult::FoundUnresolvedValue:
4061 // Immediately retry the lookup without the given CXXScopeSpec
4063 Candidate.WillReplaceSpecifier(true);
4066 if (TempMemberContext) {
4069 TempMemberContext = nullptr;
4072 if (SearchNamespaces)
4073 QualifiedResults.push_back(Candidate);
4076 case LookupResult::Ambiguous:
4077 // We don't deal with ambiguities.
4080 case LookupResult::Found:
4081 case LookupResult::FoundOverloaded:
4082 // Store all of the Decls for overloaded symbols
4083 for (auto *TRD : Result)
4084 Candidate.addCorrectionDecl(TRD);
4085 checkCorrectionVisibility(SemaRef, Candidate);
4086 if (!isCandidateViable(*CorrectionValidator, Candidate)) {
4087 if (SearchNamespaces)
4088 QualifiedResults.push_back(Candidate);
4091 Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4097 void TypoCorrectionConsumer::performQualifiedLookups() {
4098 unsigned TypoLen = Typo->getName().size();
4099 for (const TypoCorrection &QR : QualifiedResults) {
4100 for (const auto &NSI : Namespaces) {
4101 DeclContext *Ctx = NSI.DeclCtx;
4102 const Type *NSType = NSI.NameSpecifier->getAsType();
4104 // If the current NestedNameSpecifier refers to a class and the
4105 // current correction candidate is the name of that class, then skip
4106 // it as it is unlikely a qualified version of the class' constructor
4107 // is an appropriate correction.
4108 if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() :
4110 if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo())
4114 TypoCorrection TC(QR);
4115 TC.ClearCorrectionDecls();
4116 TC.setCorrectionSpecifier(NSI.NameSpecifier);
4117 TC.setQualifierDistance(NSI.EditDistance);
4118 TC.setCallbackDistance(0); // Reset the callback distance
4120 // If the current correction candidate and namespace combination are
4121 // too far away from the original typo based on the normalized edit
4122 // distance, then skip performing a qualified name lookup.
4123 unsigned TmpED = TC.getEditDistance(true);
4124 if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED &&
4125 TypoLen / TmpED < 3)
4129 Result.setLookupName(QR.getCorrectionAsIdentifierInfo());
4130 if (!SemaRef.LookupQualifiedName(Result, Ctx))
4133 // Any corrections added below will be validated in subsequent
4134 // iterations of the main while() loop over the Consumer's contents.
4135 switch (Result.getResultKind()) {
4136 case LookupResult::Found:
4137 case LookupResult::FoundOverloaded: {
4138 if (SS && SS->isValid()) {
4139 std::string NewQualified = TC.getAsString(SemaRef.getLangOpts());
4140 std::string OldQualified;
4141 llvm::raw_string_ostream OldOStream(OldQualified);
4142 SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy());
4143 OldOStream << Typo->getName();
4144 // If correction candidate would be an identical written qualified
4145 // identifer, then the existing CXXScopeSpec probably included a
4146 // typedef that didn't get accounted for properly.
4147 if (OldOStream.str() == NewQualified)
4150 for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end();
4151 TRD != TRDEnd; ++TRD) {
4152 if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(),
4153 NSType ? NSType->getAsCXXRecordDecl()
4155 TRD.getPair()) == Sema::AR_accessible)
4156 TC.addCorrectionDecl(*TRD);
4158 if (TC.isResolved()) {
4159 TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo());
4164 case LookupResult::NotFound:
4165 case LookupResult::NotFoundInCurrentInstantiation:
4166 case LookupResult::Ambiguous:
4167 case LookupResult::FoundUnresolvedValue:
4172 QualifiedResults.clear();
4175 TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet(
4176 ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec)
4177 : Context(Context), CurContextChain(buildContextChain(CurContext)) {
4178 if (NestedNameSpecifier *NNS =
4179 CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) {
4180 llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier);
4181 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4183 getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers);
4185 // Build the list of identifiers that would be used for an absolute
4186 // (from the global context) NestedNameSpecifier referring to the current
4188 for (DeclContext *C : llvm::reverse(CurContextChain)) {
4189 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C))
4190 CurContextIdentifiers.push_back(ND->getIdentifier());
4193 // Add the global context as a NestedNameSpecifier
4194 SpecifierInfo SI = {cast<DeclContext>(Context.getTranslationUnitDecl()),
4195 NestedNameSpecifier::GlobalSpecifier(Context), 1};
4196 DistanceMap[1].push_back(SI);
4199 auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain(
4200 DeclContext *Start) -> DeclContextList {
4201 assert(Start && "Building a context chain from a null context");
4202 DeclContextList Chain;
4203 for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr;
4204 DC = DC->getLookupParent()) {
4205 NamespaceDecl *ND = dyn_cast_or_null<NamespaceDecl>(DC);
4206 if (!DC->isInlineNamespace() && !DC->isTransparentContext() &&
4207 !(ND && ND->isAnonymousNamespace()))
4208 Chain.push_back(DC->getPrimaryContext());
4214 TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier(
4215 DeclContextList &DeclChain, NestedNameSpecifier *&NNS) {
4216 unsigned NumSpecifiers = 0;
4217 for (DeclContext *C : llvm::reverse(DeclChain)) {
4218 if (auto *ND = dyn_cast_or_null<NamespaceDecl>(C)) {
4219 NNS = NestedNameSpecifier::Create(Context, NNS, ND);
4221 } else if (auto *RD = dyn_cast_or_null<RecordDecl>(C)) {
4222 NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(),
4223 RD->getTypeForDecl());
4227 return NumSpecifiers;
4230 void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier(
4232 NestedNameSpecifier *NNS = nullptr;
4233 unsigned NumSpecifiers = 0;
4234 DeclContextList NamespaceDeclChain(buildContextChain(Ctx));
4235 DeclContextList FullNamespaceDeclChain(NamespaceDeclChain);
4237 // Eliminate common elements from the two DeclContext chains.
4238 for (DeclContext *C : llvm::reverse(CurContextChain)) {
4239 if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C)
4241 NamespaceDeclChain.pop_back();
4244 // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain
4245 NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS);
4247 // Add an explicit leading '::' specifier if needed.
4248 if (NamespaceDeclChain.empty()) {
4249 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4250 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4252 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4253 } else if (NamedDecl *ND =
4254 dyn_cast_or_null<NamedDecl>(NamespaceDeclChain.back())) {
4255 IdentifierInfo *Name = ND->getIdentifier();
4256 bool SameNameSpecifier = false;
4257 if (std::find(CurNameSpecifierIdentifiers.begin(),
4258 CurNameSpecifierIdentifiers.end(),
4259 Name) != CurNameSpecifierIdentifiers.end()) {
4260 std::string NewNameSpecifier;
4261 llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier);
4262 SmallVector<const IdentifierInfo *, 4> NewNameSpecifierIdentifiers;
4263 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4264 NNS->print(SpecifierOStream, Context.getPrintingPolicy());
4265 SpecifierOStream.flush();
4266 SameNameSpecifier = NewNameSpecifier == CurNameSpecifier;
4268 if (SameNameSpecifier ||
4269 std::find(CurContextIdentifiers.begin(), CurContextIdentifiers.end(),
4270 Name) != CurContextIdentifiers.end()) {
4271 // Rebuild the NestedNameSpecifier as a globally-qualified specifier.
4272 NNS = NestedNameSpecifier::GlobalSpecifier(Context);
4274 buildNestedNameSpecifier(FullNamespaceDeclChain, NNS);
4278 // If the built NestedNameSpecifier would be replacing an existing
4279 // NestedNameSpecifier, use the number of component identifiers that
4280 // would need to be changed as the edit distance instead of the number
4281 // of components in the built NestedNameSpecifier.
4282 if (NNS && !CurNameSpecifierIdentifiers.empty()) {
4283 SmallVector<const IdentifierInfo*, 4> NewNameSpecifierIdentifiers;
4284 getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers);
4285 NumSpecifiers = llvm::ComputeEditDistance(
4286 llvm::makeArrayRef(CurNameSpecifierIdentifiers),
4287 llvm::makeArrayRef(NewNameSpecifierIdentifiers));
4290 SpecifierInfo SI = {Ctx, NNS, NumSpecifiers};
4291 DistanceMap[NumSpecifiers].push_back(SI);
4294 /// \brief Perform name lookup for a possible result for typo correction.
4295 static void LookupPotentialTypoResult(Sema &SemaRef,
4297 IdentifierInfo *Name,
4298 Scope *S, CXXScopeSpec *SS,
4299 DeclContext *MemberContext,
4300 bool EnteringContext,
4301 bool isObjCIvarLookup,
4303 Res.suppressDiagnostics();
4305 Res.setLookupName(Name);
4306 Res.setAllowHidden(FindHidden);
4307 if (MemberContext) {
4308 if (ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(MemberContext)) {
4309 if (isObjCIvarLookup) {
4310 if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) {
4317 if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration(
4318 Name, ObjCPropertyQueryKind::OBJC_PR_query_instance)) {
4325 SemaRef.LookupQualifiedName(Res, MemberContext);
4329 SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false,
4332 // Fake ivar lookup; this should really be part of
4333 // LookupParsedName.
4334 if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) {
4335 if (Method->isInstanceMethod() && Method->getClassInterface() &&
4337 (Res.isSingleResult() &&
4338 Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) {
4339 if (ObjCIvarDecl *IV
4340 = Method->getClassInterface()->lookupInstanceVariable(Name)) {
4348 /// \brief Add keywords to the consumer as possible typo corrections.
4349 static void AddKeywordsToConsumer(Sema &SemaRef,
4350 TypoCorrectionConsumer &Consumer,
4351 Scope *S, CorrectionCandidateCallback &CCC,
4352 bool AfterNestedNameSpecifier) {
4353 if (AfterNestedNameSpecifier) {
4354 // For 'X::', we know exactly which keywords can appear next.
4355 Consumer.addKeywordResult("template");
4356 if (CCC.WantExpressionKeywords)
4357 Consumer.addKeywordResult("operator");
4361 if (CCC.WantObjCSuper)
4362 Consumer.addKeywordResult("super");
4364 if (CCC.WantTypeSpecifiers) {
4365 // Add type-specifier keywords to the set of results.
4366 static const char *const CTypeSpecs[] = {
4367 "char", "const", "double", "enum", "float", "int", "long", "short",
4368 "signed", "struct", "union", "unsigned", "void", "volatile",
4369 "_Complex", "_Imaginary",
4370 // storage-specifiers as well
4371 "extern", "inline", "static", "typedef"
4374 const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs);
4375 for (unsigned I = 0; I != NumCTypeSpecs; ++I)
4376 Consumer.addKeywordResult(CTypeSpecs[I]);
4378 if (SemaRef.getLangOpts().C99)
4379 Consumer.addKeywordResult("restrict");
4380 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus)
4381 Consumer.addKeywordResult("bool");
4382 else if (SemaRef.getLangOpts().C99)
4383 Consumer.addKeywordResult("_Bool");
4385 if (SemaRef.getLangOpts().CPlusPlus) {
4386 Consumer.addKeywordResult("class");
4387 Consumer.addKeywordResult("typename");
4388 Consumer.addKeywordResult("wchar_t");
4390 if (SemaRef.getLangOpts().CPlusPlus11) {
4391 Consumer.addKeywordResult("char16_t");
4392 Consumer.addKeywordResult("char32_t");
4393 Consumer.addKeywordResult("constexpr");
4394 Consumer.addKeywordResult("decltype");
4395 Consumer.addKeywordResult("thread_local");
4399 if (SemaRef.getLangOpts().GNUMode)
4400 Consumer.addKeywordResult("typeof");
4401 } else if (CCC.WantFunctionLikeCasts) {
4402 static const char *const CastableTypeSpecs[] = {
4403 "char", "double", "float", "int", "long", "short",
4404 "signed", "unsigned", "void"
4406 for (auto *kw : CastableTypeSpecs)
4407 Consumer.addKeywordResult(kw);
4410 if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) {
4411 Consumer.addKeywordResult("const_cast");
4412 Consumer.addKeywordResult("dynamic_cast");
4413 Consumer.addKeywordResult("reinterpret_cast");
4414 Consumer.addKeywordResult("static_cast");
4417 if (CCC.WantExpressionKeywords) {
4418 Consumer.addKeywordResult("sizeof");
4419 if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) {
4420 Consumer.addKeywordResult("false");
4421 Consumer.addKeywordResult("true");
4424 if (SemaRef.getLangOpts().CPlusPlus) {
4425 static const char *const CXXExprs[] = {
4426 "delete", "new", "operator", "throw", "typeid"
4428 const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs);
4429 for (unsigned I = 0; I != NumCXXExprs; ++I)
4430 Consumer.addKeywordResult(CXXExprs[I]);
4432 if (isa<CXXMethodDecl>(SemaRef.CurContext) &&
4433 cast<CXXMethodDecl>(SemaRef.CurContext)->isInstance())
4434 Consumer.addKeywordResult("this");
4436 if (SemaRef.getLangOpts().CPlusPlus11) {
4437 Consumer.addKeywordResult("alignof");
4438 Consumer.addKeywordResult("nullptr");
4442 if (SemaRef.getLangOpts().C11) {
4443 // FIXME: We should not suggest _Alignof if the alignof macro
4445 Consumer.addKeywordResult("_Alignof");
4449 if (CCC.WantRemainingKeywords) {
4450 if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) {
4452 static const char *const CStmts[] = {
4453 "do", "else", "for", "goto", "if", "return", "switch", "while" };
4454 const unsigned NumCStmts = llvm::array_lengthof(CStmts);
4455 for (unsigned I = 0; I != NumCStmts; ++I)
4456 Consumer.addKeywordResult(CStmts[I]);
4458 if (SemaRef.getLangOpts().CPlusPlus) {
4459 Consumer.addKeywordResult("catch");
4460 Consumer.addKeywordResult("try");
4463 if (S && S->getBreakParent())
4464 Consumer.addKeywordResult("break");
4466 if (S && S->getContinueParent())
4467 Consumer.addKeywordResult("continue");
4469 if (!SemaRef.getCurFunction()->SwitchStack.empty()) {
4470 Consumer.addKeywordResult("case");
4471 Consumer.addKeywordResult("default");
4474 if (SemaRef.getLangOpts().CPlusPlus) {
4475 Consumer.addKeywordResult("namespace");
4476 Consumer.addKeywordResult("template");
4479 if (S && S->isClassScope()) {
4480 Consumer.addKeywordResult("explicit");
4481 Consumer.addKeywordResult("friend");
4482 Consumer.addKeywordResult("mutable");
4483 Consumer.addKeywordResult("private");
4484 Consumer.addKeywordResult("protected");
4485 Consumer.addKeywordResult("public");
4486 Consumer.addKeywordResult("virtual");
4490 if (SemaRef.getLangOpts().CPlusPlus) {
4491 Consumer.addKeywordResult("using");
4493 if (SemaRef.getLangOpts().CPlusPlus11)
4494 Consumer.addKeywordResult("static_assert");
4499 std::unique_ptr<TypoCorrectionConsumer> Sema::makeTypoCorrectionConsumer(
4500 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4501 Scope *S, CXXScopeSpec *SS,
4502 std::unique_ptr<CorrectionCandidateCallback> CCC,
4503 DeclContext *MemberContext, bool EnteringContext,
4504 const ObjCObjectPointerType *OPT, bool ErrorRecovery) {
4506 if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking ||
4507 DisableTypoCorrection)
4510 // In Microsoft mode, don't perform typo correction in a template member
4511 // function dependent context because it interferes with the "lookup into
4512 // dependent bases of class templates" feature.
4513 if (getLangOpts().MSVCCompat && CurContext->isDependentContext() &&
4514 isa<CXXMethodDecl>(CurContext))
4517 // We only attempt to correct typos for identifiers.
4518 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4522 // If the scope specifier itself was invalid, don't try to correct
4524 if (SS && SS->isInvalid())
4527 // Never try to correct typos during any kind of code synthesis.
4528 if (!CodeSynthesisContexts.empty())
4531 // Don't try to correct 'super'.
4532 if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier())
4535 // Abort if typo correction already failed for this specific typo.
4536 IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo);
4537 if (locs != TypoCorrectionFailures.end() &&
4538 locs->second.count(TypoName.getLoc()))
4541 // Don't try to correct the identifier "vector" when in AltiVec mode.
4542 // TODO: Figure out why typo correction misbehaves in this case, fix it, and
4543 // remove this workaround.
4544 if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector"))
4547 // Provide a stop gap for files that are just seriously broken. Trying
4548 // to correct all typos can turn into a HUGE performance penalty, causing
4549 // some files to take minutes to get rejected by the parser.
4550 unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit;
4551 if (Limit && TyposCorrected >= Limit)
4555 // If we're handling a missing symbol error, using modules, and the
4556 // special search all modules option is used, look for a missing import.
4557 if (ErrorRecovery && getLangOpts().Modules &&
4558 getLangOpts().ModulesSearchAll) {
4559 // The following has the side effect of loading the missing module.
4560 getModuleLoader().lookupMissingImports(Typo->getName(),
4561 TypoName.getLocStart());
4564 CorrectionCandidateCallback &CCCRef = *CCC;
4565 auto Consumer = llvm::make_unique<TypoCorrectionConsumer>(
4566 *this, TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4569 // Perform name lookup to find visible, similarly-named entities.
4570 bool IsUnqualifiedLookup = false;
4571 DeclContext *QualifiedDC = MemberContext;
4572 if (MemberContext) {
4573 LookupVisibleDecls(MemberContext, LookupKind, *Consumer);
4575 // Look in qualified interfaces.
4577 for (auto *I : OPT->quals())
4578 LookupVisibleDecls(I, LookupKind, *Consumer);
4580 } else if (SS && SS->isSet()) {
4581 QualifiedDC = computeDeclContext(*SS, EnteringContext);
4585 LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer);
4587 IsUnqualifiedLookup = true;
4590 // Determine whether we are going to search in the various namespaces for
4592 bool SearchNamespaces
4593 = getLangOpts().CPlusPlus &&
4594 (IsUnqualifiedLookup || (SS && SS->isSet()));
4596 if (IsUnqualifiedLookup || SearchNamespaces) {
4597 // For unqualified lookup, look through all of the names that we have
4598 // seen in this translation unit.
4599 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4600 for (const auto &I : Context.Idents)
4601 Consumer->FoundName(I.getKey());
4603 // Walk through identifiers in external identifier sources.
4604 // FIXME: Re-add the ability to skip very unlikely potential corrections.
4605 if (IdentifierInfoLookup *External
4606 = Context.Idents.getExternalIdentifierLookup()) {
4607 std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
4609 StringRef Name = Iter->Next();
4613 Consumer->FoundName(Name);
4618 AddKeywordsToConsumer(*this, *Consumer, S, CCCRef, SS && SS->isNotEmpty());
4620 // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going
4621 // to search those namespaces.
4622 if (SearchNamespaces) {
4623 // Load any externally-known namespaces.
4624 if (ExternalSource && !LoadedExternalKnownNamespaces) {
4625 SmallVector<NamespaceDecl *, 4> ExternalKnownNamespaces;
4626 LoadedExternalKnownNamespaces = true;
4627 ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces);
4628 for (auto *N : ExternalKnownNamespaces)
4629 KnownNamespaces[N] = true;
4632 Consumer->addNamespaces(KnownNamespaces);
4638 /// \brief Try to "correct" a typo in the source code by finding
4639 /// visible declarations whose names are similar to the name that was
4640 /// present in the source code.
4642 /// \param TypoName the \c DeclarationNameInfo structure that contains
4643 /// the name that was present in the source code along with its location.
4645 /// \param LookupKind the name-lookup criteria used to search for the name.
4647 /// \param S the scope in which name lookup occurs.
4649 /// \param SS the nested-name-specifier that precedes the name we're
4650 /// looking for, if present.
4652 /// \param CCC A CorrectionCandidateCallback object that provides further
4653 /// validation of typo correction candidates. It also provides flags for
4654 /// determining the set of keywords permitted.
4656 /// \param MemberContext if non-NULL, the context in which to look for
4657 /// a member access expression.
4659 /// \param EnteringContext whether we're entering the context described by
4660 /// the nested-name-specifier SS.
4662 /// \param OPT when non-NULL, the search for visible declarations will
4663 /// also walk the protocols in the qualified interfaces of \p OPT.
4665 /// \returns a \c TypoCorrection containing the corrected name if the typo
4666 /// along with information such as the \c NamedDecl where the corrected name
4667 /// was declared, and any additional \c NestedNameSpecifier needed to access
4668 /// it (C++ only). The \c TypoCorrection is empty if there is no correction.
4669 TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName,
4670 Sema::LookupNameKind LookupKind,
4671 Scope *S, CXXScopeSpec *SS,
4672 std::unique_ptr<CorrectionCandidateCallback> CCC,
4673 CorrectTypoKind Mode,
4674 DeclContext *MemberContext,
4675 bool EnteringContext,
4676 const ObjCObjectPointerType *OPT,
4677 bool RecordFailure) {
4678 assert(CCC && "CorrectTypo requires a CorrectionCandidateCallback");
4680 // Always let the ExternalSource have the first chance at correction, even
4681 // if we would otherwise have given up.
4682 if (ExternalSource) {
4683 if (TypoCorrection Correction = ExternalSource->CorrectTypo(
4684 TypoName, LookupKind, S, SS, *CCC, MemberContext, EnteringContext, OPT))
4688 // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver;
4689 // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for
4690 // some instances of CTC_Unknown, while WantRemainingKeywords is true
4691 // for CTC_Unknown but not for CTC_ObjCMessageReceiver.
4692 bool ObjCMessageReceiver = CCC->WantObjCSuper && !CCC->WantRemainingKeywords;
4694 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4695 auto Consumer = makeTypoCorrectionConsumer(
4696 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4697 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4700 return TypoCorrection();
4702 // If we haven't found anything, we're done.
4703 if (Consumer->empty())
4704 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4706 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4707 // is not more that about a third of the length of the typo's identifier.
4708 unsigned ED = Consumer->getBestEditDistance(true);
4709 unsigned TypoLen = Typo->getName().size();
4710 if (ED > 0 && TypoLen / ED < 3)
4711 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4713 TypoCorrection BestTC = Consumer->getNextCorrection();
4714 TypoCorrection SecondBestTC = Consumer->getNextCorrection();
4716 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4718 ED = BestTC.getEditDistance();
4720 if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) {
4721 // If this was an unqualified lookup and we believe the callback
4722 // object wouldn't have filtered out possible corrections, note
4723 // that no correction was found.
4724 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4727 // If only a single name remains, return that result.
4728 if (!SecondBestTC ||
4729 SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) {
4730 const TypoCorrection &Result = BestTC;
4732 // Don't correct to a keyword that's the same as the typo; the keyword
4733 // wasn't actually in scope.
4734 if (ED == 0 && Result.isKeyword())
4735 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4737 TypoCorrection TC = Result;
4738 TC.setCorrectionRange(SS, TypoName);
4739 checkCorrectionVisibility(*this, TC);
4741 } else if (SecondBestTC && ObjCMessageReceiver) {
4742 // Prefer 'super' when we're completing in a message-receiver
4745 if (BestTC.getCorrection().getAsString() != "super") {
4746 if (SecondBestTC.getCorrection().getAsString() == "super")
4747 BestTC = SecondBestTC;
4748 else if ((*Consumer)["super"].front().isKeyword())
4749 BestTC = (*Consumer)["super"].front();
4751 // Don't correct to a keyword that's the same as the typo; the keyword
4752 // wasn't actually in scope.
4753 if (BestTC.getEditDistance() == 0 ||
4754 BestTC.getCorrection().getAsString() != "super")
4755 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure);
4757 BestTC.setCorrectionRange(SS, TypoName);
4761 // Record the failure's location if needed and return an empty correction. If
4762 // this was an unqualified lookup and we believe the callback object did not
4763 // filter out possible corrections, also cache the failure for the typo.
4764 return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC);
4767 /// \brief Try to "correct" a typo in the source code by finding
4768 /// visible declarations whose names are similar to the name that was
4769 /// present in the source code.
4771 /// \param TypoName the \c DeclarationNameInfo structure that contains
4772 /// the name that was present in the source code along with its location.
4774 /// \param LookupKind the name-lookup criteria used to search for the name.
4776 /// \param S the scope in which name lookup occurs.
4778 /// \param SS the nested-name-specifier that precedes the name we're
4779 /// looking for, if present.
4781 /// \param CCC A CorrectionCandidateCallback object that provides further
4782 /// validation of typo correction candidates. It also provides flags for
4783 /// determining the set of keywords permitted.
4785 /// \param TDG A TypoDiagnosticGenerator functor that will be used to print
4786 /// diagnostics when the actual typo correction is attempted.
4788 /// \param TRC A TypoRecoveryCallback functor that will be used to build an
4789 /// Expr from a typo correction candidate.
4791 /// \param MemberContext if non-NULL, the context in which to look for
4792 /// a member access expression.
4794 /// \param EnteringContext whether we're entering the context described by
4795 /// the nested-name-specifier SS.
4797 /// \param OPT when non-NULL, the search for visible declarations will
4798 /// also walk the protocols in the qualified interfaces of \p OPT.
4800 /// \returns a new \c TypoExpr that will later be replaced in the AST with an
4801 /// Expr representing the result of performing typo correction, or nullptr if
4802 /// typo correction is not possible. If nullptr is returned, no diagnostics will
4803 /// be emitted and it is the responsibility of the caller to emit any that are
4805 TypoExpr *Sema::CorrectTypoDelayed(
4806 const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind,
4807 Scope *S, CXXScopeSpec *SS,
4808 std::unique_ptr<CorrectionCandidateCallback> CCC,
4809 TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode,
4810 DeclContext *MemberContext, bool EnteringContext,
4811 const ObjCObjectPointerType *OPT) {
4812 assert(CCC && "CorrectTypoDelayed requires a CorrectionCandidateCallback");
4814 auto Consumer = makeTypoCorrectionConsumer(
4815 TypoName, LookupKind, S, SS, std::move(CCC), MemberContext,
4816 EnteringContext, OPT, Mode == CTK_ErrorRecovery);
4818 // Give the external sema source a chance to correct the typo.
4819 TypoCorrection ExternalTypo;
4820 if (ExternalSource && Consumer) {
4821 ExternalTypo = ExternalSource->CorrectTypo(
4822 TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(),
4823 MemberContext, EnteringContext, OPT);
4825 Consumer->addCorrection(ExternalTypo);
4828 if (!Consumer || Consumer->empty())
4831 // Make sure the best edit distance (prior to adding any namespace qualifiers)
4832 // is not more that about a third of the length of the typo's identifier.
4833 unsigned ED = Consumer->getBestEditDistance(true);
4834 IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo();
4835 if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3)
4838 ExprEvalContexts.back().NumTypos++;
4839 return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC));
4842 void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) {
4846 CorrectionDecls.clear();
4848 CorrectionDecls.push_back(CDecl);
4850 if (!CorrectionName)
4851 CorrectionName = CDecl->getDeclName();
4854 std::string TypoCorrection::getAsString(const LangOptions &LO) const {
4855 if (CorrectionNameSpec) {
4856 std::string tmpBuffer;
4857 llvm::raw_string_ostream PrefixOStream(tmpBuffer);
4858 CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO));
4859 PrefixOStream << CorrectionName;
4860 return PrefixOStream.str();
4863 return CorrectionName.getAsString();
4866 bool CorrectionCandidateCallback::ValidateCandidate(
4867 const TypoCorrection &candidate) {
4868 if (!candidate.isResolved())
4871 if (candidate.isKeyword())
4872 return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts ||
4873 WantRemainingKeywords || WantObjCSuper;
4875 bool HasNonType = false;
4876 bool HasStaticMethod = false;
4877 bool HasNonStaticMethod = false;
4878 for (Decl *D : candidate) {
4879 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(D))
4880 D = FTD->getTemplatedDecl();
4881 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
4882 if (Method->isStatic())
4883 HasStaticMethod = true;
4885 HasNonStaticMethod = true;
4887 if (!isa<TypeDecl>(D))
4891 if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod &&
4892 !candidate.getCorrectionSpecifier())
4895 return WantTypeSpecifiers || HasNonType;
4898 FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs,
4899 bool HasExplicitTemplateArgs,
4901 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs),
4902 CurContext(SemaRef.CurContext), MemberFn(ME) {
4903 WantTypeSpecifiers = false;
4904 WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && NumArgs == 1;
4905 WantRemainingKeywords = false;
4908 bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) {
4909 if (!candidate.getCorrectionDecl())
4910 return candidate.isKeyword();
4912 for (auto *C : candidate) {
4913 FunctionDecl *FD = nullptr;
4914 NamedDecl *ND = C->getUnderlyingDecl();
4915 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
4916 FD = FTD->getTemplatedDecl();
4917 if (!HasExplicitTemplateArgs && !FD) {
4918 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) {
4919 // If the Decl is neither a function nor a template function,
4920 // determine if it is a pointer or reference to a function. If so,
4921 // check against the number of arguments expected for the pointee.
4922 QualType ValType = cast<ValueDecl>(ND)->getType();
4923 if (ValType->isAnyPointerType() || ValType->isReferenceType())
4924 ValType = ValType->getPointeeType();
4925 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>())
4926 if (FPT->getNumParams() == NumArgs)
4931 // Skip the current candidate if it is not a FunctionDecl or does not accept
4932 // the current number of arguments.
4933 if (!FD || !(FD->getNumParams() >= NumArgs &&
4934 FD->getMinRequiredArguments() <= NumArgs))
4937 // If the current candidate is a non-static C++ method, skip the candidate
4938 // unless the method being corrected--or the current DeclContext, if the
4939 // function being corrected is not a method--is a method in the same class
4940 // or a descendent class of the candidate's parent class.
4941 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
4942 if (MemberFn || !MD->isStatic()) {
4943 CXXMethodDecl *CurMD =
4945 ? dyn_cast_or_null<CXXMethodDecl>(MemberFn->getMemberDecl())
4946 : dyn_cast_or_null<CXXMethodDecl>(CurContext);
4947 CXXRecordDecl *CurRD =
4948 CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr;
4949 CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl();
4950 if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD)))
4959 void Sema::diagnoseTypo(const TypoCorrection &Correction,
4960 const PartialDiagnostic &TypoDiag,
4961 bool ErrorRecovery) {
4962 diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl),
4966 /// Find which declaration we should import to provide the definition of
4967 /// the given declaration.
4968 static NamedDecl *getDefinitionToImport(NamedDecl *D) {
4969 if (VarDecl *VD = dyn_cast<VarDecl>(D))
4970 return VD->getDefinition();
4971 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
4972 return FD->getDefinition();
4973 if (TagDecl *TD = dyn_cast<TagDecl>(D))
4974 return TD->getDefinition();
4975 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(D))
4976 return ID->getDefinition();
4977 if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D))
4978 return PD->getDefinition();
4979 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
4980 return getDefinitionToImport(TD->getTemplatedDecl());
4984 void Sema::diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl,
4985 MissingImportKind MIK, bool Recover) {
4986 // Suggest importing a module providing the definition of this entity, if
4988 NamedDecl *Def = getDefinitionToImport(Decl);
4992 Module *Owner = getOwningModule(Decl);
4993 assert(Owner && "definition of hidden declaration is not in a module");
4995 llvm::SmallVector<Module*, 8> OwningModules;
4996 OwningModules.push_back(Owner);
4997 auto Merged = Context.getModulesWithMergedDefinition(Decl);
4998 OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end());
5000 diagnoseMissingImport(Loc, Decl, Decl->getLocation(), OwningModules, MIK,
5004 /// \brief Get a "quoted.h" or <angled.h> include path to use in a diagnostic
5005 /// suggesting the addition of a #include of the specified file.
5006 static std::string getIncludeStringForHeader(Preprocessor &PP,
5007 const FileEntry *E) {
5010 PP.getHeaderSearchInfo().suggestPathToFileForDiagnostics(E, &IsSystem);
5011 return (IsSystem ? '<' : '"') + Path + (IsSystem ? '>' : '"');
5014 void Sema::diagnoseMissingImport(SourceLocation UseLoc, NamedDecl *Decl,
5015 SourceLocation DeclLoc,
5016 ArrayRef<Module *> Modules,
5017 MissingImportKind MIK, bool Recover) {
5018 assert(!Modules.empty());
5020 // Weed out duplicates from module list.
5021 llvm::SmallVector<Module*, 8> UniqueModules;
5022 llvm::SmallDenseSet<Module*, 8> UniqueModuleSet;
5023 for (auto *M : Modules)
5024 if (UniqueModuleSet.insert(M).second)
5025 UniqueModules.push_back(M);
5026 Modules = UniqueModules;
5028 if (Modules.size() > 1) {
5029 std::string ModuleList;
5031 for (Module *M : Modules) {
5032 ModuleList += "\n ";
5033 if (++N == 5 && N != Modules.size()) {
5034 ModuleList += "[...]";
5037 ModuleList += M->getFullModuleName();
5040 Diag(UseLoc, diag::err_module_unimported_use_multiple)
5041 << (int)MIK << Decl << ModuleList;
5042 } else if (const FileEntry *E = PP.getModuleHeaderToIncludeForDiagnostics(
5043 UseLoc, Modules[0], DeclLoc)) {
5044 // The right way to make the declaration visible is to include a header;
5045 // suggest doing so.
5047 // FIXME: Find a smart place to suggest inserting a #include, and add
5048 // a FixItHint there.
5049 Diag(UseLoc, diag::err_module_unimported_use_header)
5050 << (int)MIK << Decl << Modules[0]->getFullModuleName()
5051 << getIncludeStringForHeader(PP, E);
5053 // FIXME: Add a FixItHint that imports the corresponding module.
5054 Diag(UseLoc, diag::err_module_unimported_use)
5055 << (int)MIK << Decl << Modules[0]->getFullModuleName();
5060 case MissingImportKind::Declaration:
5061 DiagID = diag::note_previous_declaration;
5063 case MissingImportKind::Definition:
5064 DiagID = diag::note_previous_definition;
5066 case MissingImportKind::DefaultArgument:
5067 DiagID = diag::note_default_argument_declared_here;
5069 case MissingImportKind::ExplicitSpecialization:
5070 DiagID = diag::note_explicit_specialization_declared_here;
5072 case MissingImportKind::PartialSpecialization:
5073 DiagID = diag::note_partial_specialization_declared_here;
5076 Diag(DeclLoc, DiagID);
5078 // Try to recover by implicitly importing this module.
5080 createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]);
5083 /// \brief Diagnose a successfully-corrected typo. Separated from the correction
5084 /// itself to allow external validation of the result, etc.
5086 /// \param Correction The result of performing typo correction.
5087 /// \param TypoDiag The diagnostic to produce. This will have the corrected
5088 /// string added to it (and usually also a fixit).
5089 /// \param PrevNote A note to use when indicating the location of the entity to
5090 /// which we are correcting. Will have the correction string added to it.
5091 /// \param ErrorRecovery If \c true (the default), the caller is going to
5092 /// recover from the typo as if the corrected string had been typed.
5093 /// In this case, \c PDiag must be an error, and we will attach a fixit
5095 void Sema::diagnoseTypo(const TypoCorrection &Correction,
5096 const PartialDiagnostic &TypoDiag,
5097 const PartialDiagnostic &PrevNote,
5098 bool ErrorRecovery) {
5099 std::string CorrectedStr = Correction.getAsString(getLangOpts());
5100 std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts());
5101 FixItHint FixTypo = FixItHint::CreateReplacement(
5102 Correction.getCorrectionRange(), CorrectedStr);
5104 // Maybe we're just missing a module import.
5105 if (Correction.requiresImport()) {
5106 NamedDecl *Decl = Correction.getFoundDecl();
5107 assert(Decl && "import required but no declaration to import");
5109 diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl,
5110 MissingImportKind::Declaration, ErrorRecovery);
5114 Diag(Correction.getCorrectionRange().getBegin(), TypoDiag)
5115 << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint());
5117 NamedDecl *ChosenDecl =
5118 Correction.isKeyword() ? nullptr : Correction.getFoundDecl();
5119 if (PrevNote.getDiagID() && ChosenDecl)
5120 Diag(ChosenDecl->getLocation(), PrevNote)
5121 << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo);
5123 // Add any extra diagnostics.
5124 for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
5125 Diag(Correction.getCorrectionRange().getBegin(), PD);
5128 TypoExpr *Sema::createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
5129 TypoDiagnosticGenerator TDG,
5130 TypoRecoveryCallback TRC) {
5131 assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer");
5132 auto TE = new (Context) TypoExpr(Context.DependentTy);
5133 auto &State = DelayedTypos[TE];
5134 State.Consumer = std::move(TCC);
5135 State.DiagHandler = std::move(TDG);
5136 State.RecoveryHandler = std::move(TRC);
5140 const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const {
5141 auto Entry = DelayedTypos.find(TE);
5142 assert(Entry != DelayedTypos.end() &&
5143 "Failed to get the state for a TypoExpr!");
5144 return Entry->second;
5147 void Sema::clearDelayedTypo(TypoExpr *TE) {
5148 DelayedTypos.erase(TE);
5151 void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) {
5152 DeclarationNameInfo Name(II, IILoc);
5153 LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration);
5154 R.suppressDiagnostics();
5155 R.setHideTags(false);