//===--------------------- SemaLookup.cpp - Name Lookup ------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements name lookup for C, C++, Objective-C, and // Objective-C++. // //===----------------------------------------------------------------------===// #include "clang/Sema/Lookup.h" #include "clang/AST/ASTContext.h" #include "clang/AST/ASTMutationListener.h" #include "clang/AST/CXXInheritance.h" #include "clang/AST/Decl.h" #include "clang/AST/DeclCXX.h" #include "clang/AST/DeclLookups.h" #include "clang/AST/DeclObjC.h" #include "clang/AST/DeclTemplate.h" #include "clang/AST/Expr.h" #include "clang/AST/ExprCXX.h" #include "clang/Basic/Builtins.h" #include "clang/Basic/LangOptions.h" #include "clang/Lex/HeaderSearch.h" #include "clang/Lex/ModuleLoader.h" #include "clang/Lex/Preprocessor.h" #include "clang/Sema/DeclSpec.h" #include "clang/Sema/Overload.h" #include "clang/Sema/Scope.h" #include "clang/Sema/ScopeInfo.h" #include "clang/Sema/Sema.h" #include "clang/Sema/SemaInternal.h" #include "clang/Sema/TemplateDeduction.h" #include "clang/Sema/TypoCorrection.h" #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/SetVector.h" #include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/StringMap.h" #include "llvm/ADT/TinyPtrVector.h" #include "llvm/ADT/edit_distance.h" #include "llvm/Support/ErrorHandling.h" #include #include #include #include #include #include #include #include using namespace clang; using namespace sema; namespace { class UnqualUsingEntry { const DeclContext *Nominated; const DeclContext *CommonAncestor; public: UnqualUsingEntry(const DeclContext *Nominated, const DeclContext *CommonAncestor) : Nominated(Nominated), CommonAncestor(CommonAncestor) { } const DeclContext *getCommonAncestor() const { return CommonAncestor; } const DeclContext *getNominatedNamespace() const { return Nominated; } // Sort by the pointer value of the common ancestor. struct Comparator { bool operator()(const UnqualUsingEntry &L, const UnqualUsingEntry &R) { return L.getCommonAncestor() < R.getCommonAncestor(); } bool operator()(const UnqualUsingEntry &E, const DeclContext *DC) { return E.getCommonAncestor() < DC; } bool operator()(const DeclContext *DC, const UnqualUsingEntry &E) { return DC < E.getCommonAncestor(); } }; }; /// A collection of using directives, as used by C++ unqualified /// lookup. class UnqualUsingDirectiveSet { typedef SmallVector ListTy; ListTy list; llvm::SmallPtrSet visited; public: UnqualUsingDirectiveSet() {} void visitScopeChain(Scope *S, Scope *InnermostFileScope) { // C++ [namespace.udir]p1: // During unqualified name lookup, the names appear as if they // were declared in the nearest enclosing namespace which contains // both the using-directive and the nominated namespace. DeclContext *InnermostFileDC = InnermostFileScope->getEntity(); assert(InnermostFileDC && InnermostFileDC->isFileContext()); for (; S; S = S->getParent()) { // C++ [namespace.udir]p1: // A using-directive shall not appear in class scope, but may // appear in namespace scope or in block scope. DeclContext *Ctx = S->getEntity(); if (Ctx && Ctx->isFileContext()) { visit(Ctx, Ctx); } else if (!Ctx || Ctx->isFunctionOrMethod()) { for (auto *I : S->using_directives()) visit(I, InnermostFileDC); } } } // Visits a context and collect all of its using directives // recursively. Treats all using directives as if they were // declared in the context. // // A given context is only every visited once, so it is important // that contexts be visited from the inside out in order to get // the effective DCs right. void visit(DeclContext *DC, DeclContext *EffectiveDC) { if (!visited.insert(DC).second) return; addUsingDirectives(DC, EffectiveDC); } // Visits a using directive and collects all of its using // directives recursively. Treats all using directives as if they // were declared in the effective DC. void visit(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { DeclContext *NS = UD->getNominatedNamespace(); if (!visited.insert(NS).second) return; addUsingDirective(UD, EffectiveDC); addUsingDirectives(NS, EffectiveDC); } // Adds all the using directives in a context (and those nominated // by its using directives, transitively) as if they appeared in // the given effective context. void addUsingDirectives(DeclContext *DC, DeclContext *EffectiveDC) { SmallVector queue; while (true) { for (auto UD : DC->using_directives()) { DeclContext *NS = UD->getNominatedNamespace(); if (visited.insert(NS).second) { addUsingDirective(UD, EffectiveDC); queue.push_back(NS); } } if (queue.empty()) return; DC = queue.pop_back_val(); } } // Add a using directive as if it had been declared in the given // context. This helps implement C++ [namespace.udir]p3: // The using-directive is transitive: if a scope contains a // using-directive that nominates a second namespace that itself // contains using-directives, the effect is as if the // using-directives from the second namespace also appeared in // the first. void addUsingDirective(UsingDirectiveDecl *UD, DeclContext *EffectiveDC) { // Find the common ancestor between the effective context and // the nominated namespace. DeclContext *Common = UD->getNominatedNamespace(); while (!Common->Encloses(EffectiveDC)) Common = Common->getParent(); Common = Common->getPrimaryContext(); list.push_back(UnqualUsingEntry(UD->getNominatedNamespace(), Common)); } void done() { std::sort(list.begin(), list.end(), UnqualUsingEntry::Comparator()); } typedef ListTy::const_iterator const_iterator; const_iterator begin() const { return list.begin(); } const_iterator end() const { return list.end(); } llvm::iterator_range getNamespacesFor(DeclContext *DC) const { return llvm::make_range(std::equal_range(begin(), end(), DC->getPrimaryContext(), UnqualUsingEntry::Comparator())); } }; } // end anonymous namespace // Retrieve the set of identifier namespaces that correspond to a // specific kind of name lookup. static inline unsigned getIDNS(Sema::LookupNameKind NameKind, bool CPlusPlus, bool Redeclaration) { unsigned IDNS = 0; switch (NameKind) { case Sema::LookupObjCImplicitSelfParam: case Sema::LookupOrdinaryName: case Sema::LookupRedeclarationWithLinkage: case Sema::LookupLocalFriendName: IDNS = Decl::IDNS_Ordinary; if (CPlusPlus) { IDNS |= Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Namespace; if (Redeclaration) IDNS |= Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend; } if (Redeclaration) IDNS |= Decl::IDNS_LocalExtern; break; case Sema::LookupOperatorName: // Operator lookup is its own crazy thing; it is not the same // as (e.g.) looking up an operator name for redeclaration. assert(!Redeclaration && "cannot do redeclaration operator lookup"); IDNS = Decl::IDNS_NonMemberOperator; break; case Sema::LookupTagName: if (CPlusPlus) { IDNS = Decl::IDNS_Type; // When looking for a redeclaration of a tag name, we add: // 1) TagFriend to find undeclared friend decls // 2) Namespace because they can't "overload" with tag decls. // 3) Tag because it includes class templates, which can't // "overload" with tag decls. if (Redeclaration) IDNS |= Decl::IDNS_Tag | Decl::IDNS_TagFriend | Decl::IDNS_Namespace; } else { IDNS = Decl::IDNS_Tag; } break; case Sema::LookupLabel: IDNS = Decl::IDNS_Label; break; case Sema::LookupMemberName: IDNS = Decl::IDNS_Member; if (CPlusPlus) IDNS |= Decl::IDNS_Tag | Decl::IDNS_Ordinary; break; case Sema::LookupNestedNameSpecifierName: IDNS = Decl::IDNS_Type | Decl::IDNS_Namespace; break; case Sema::LookupNamespaceName: IDNS = Decl::IDNS_Namespace; break; case Sema::LookupUsingDeclName: assert(Redeclaration && "should only be used for redecl lookup"); IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Using | Decl::IDNS_TagFriend | Decl::IDNS_OrdinaryFriend | Decl::IDNS_LocalExtern; break; case Sema::LookupObjCProtocolName: IDNS = Decl::IDNS_ObjCProtocol; break; case Sema::LookupOMPReductionName: IDNS = Decl::IDNS_OMPReduction; break; case Sema::LookupAnyName: IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member | Decl::IDNS_Using | Decl::IDNS_Namespace | Decl::IDNS_ObjCProtocol | Decl::IDNS_Type; break; } return IDNS; } void LookupResult::configure() { IDNS = getIDNS(LookupKind, getSema().getLangOpts().CPlusPlus, isForRedeclaration()); // If we're looking for one of the allocation or deallocation // operators, make sure that the implicitly-declared new and delete // operators can be found. switch (NameInfo.getName().getCXXOverloadedOperator()) { case OO_New: case OO_Delete: case OO_Array_New: case OO_Array_Delete: getSema().DeclareGlobalNewDelete(); break; default: break; } // Compiler builtins are always visible, regardless of where they end // up being declared. if (IdentifierInfo *Id = NameInfo.getName().getAsIdentifierInfo()) { if (unsigned BuiltinID = Id->getBuiltinID()) { if (!getSema().Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) AllowHidden = true; } } } bool LookupResult::sanity() const { // This function is never called by NDEBUG builds. assert(ResultKind != NotFound || Decls.size() == 0); assert(ResultKind != Found || Decls.size() == 1); assert(ResultKind != FoundOverloaded || Decls.size() > 1 || (Decls.size() == 1 && isa((*begin())->getUnderlyingDecl()))); assert(ResultKind != FoundUnresolvedValue || sanityCheckUnresolved()); assert(ResultKind != Ambiguous || Decls.size() > 1 || (Decls.size() == 1 && (Ambiguity == AmbiguousBaseSubobjects || Ambiguity == AmbiguousBaseSubobjectTypes))); assert((Paths != nullptr) == (ResultKind == Ambiguous && (Ambiguity == AmbiguousBaseSubobjectTypes || Ambiguity == AmbiguousBaseSubobjects))); return true; } // Necessary because CXXBasePaths is not complete in Sema.h void LookupResult::deletePaths(CXXBasePaths *Paths) { delete Paths; } /// Get a representative context for a declaration such that two declarations /// will have the same context if they were found within the same scope. static DeclContext *getContextForScopeMatching(Decl *D) { // For function-local declarations, use that function as the context. This // doesn't account for scopes within the function; the caller must deal with // those. DeclContext *DC = D->getLexicalDeclContext(); if (DC->isFunctionOrMethod()) return DC; // Otherwise, look at the semantic context of the declaration. The // declaration must have been found there. return D->getDeclContext()->getRedeclContext(); } /// \brief Determine whether \p D is a better lookup result than \p Existing, /// given that they declare the same entity. static bool isPreferredLookupResult(Sema &S, Sema::LookupNameKind Kind, NamedDecl *D, NamedDecl *Existing) { // When looking up redeclarations of a using declaration, prefer a using // shadow declaration over any other declaration of the same entity. if (Kind == Sema::LookupUsingDeclName && isa(D) && !isa(Existing)) return true; auto *DUnderlying = D->getUnderlyingDecl(); auto *EUnderlying = Existing->getUnderlyingDecl(); // If they have different underlying declarations, prefer a typedef over the // original type (this happens when two type declarations denote the same // type), per a generous reading of C++ [dcl.typedef]p3 and p4. The typedef // might carry additional semantic information, such as an alignment override. // However, per C++ [dcl.typedef]p5, when looking up a tag name, prefer a tag // declaration over a typedef. if (DUnderlying->getCanonicalDecl() != EUnderlying->getCanonicalDecl()) { assert(isa(DUnderlying) && isa(EUnderlying)); bool HaveTag = isa(EUnderlying); bool WantTag = Kind == Sema::LookupTagName; return HaveTag != WantTag; } // Pick the function with more default arguments. // FIXME: In the presence of ambiguous default arguments, we should keep both, // so we can diagnose the ambiguity if the default argument is needed. // See C++ [over.match.best]p3. if (auto *DFD = dyn_cast(DUnderlying)) { auto *EFD = cast(EUnderlying); unsigned DMin = DFD->getMinRequiredArguments(); unsigned EMin = EFD->getMinRequiredArguments(); // If D has more default arguments, it is preferred. if (DMin != EMin) return DMin < EMin; // FIXME: When we track visibility for default function arguments, check // that we pick the declaration with more visible default arguments. } // Pick the template with more default template arguments. if (auto *DTD = dyn_cast(DUnderlying)) { auto *ETD = cast(EUnderlying); unsigned DMin = DTD->getTemplateParameters()->getMinRequiredArguments(); unsigned EMin = ETD->getTemplateParameters()->getMinRequiredArguments(); // If D has more default arguments, it is preferred. Note that default // arguments (and their visibility) is monotonically increasing across the // redeclaration chain, so this is a quick proxy for "is more recent". if (DMin != EMin) return DMin < EMin; // If D has more *visible* default arguments, it is preferred. Note, an // earlier default argument being visible does not imply that a later // default argument is visible, so we can't just check the first one. for (unsigned I = DMin, N = DTD->getTemplateParameters()->size(); I != N; ++I) { if (!S.hasVisibleDefaultArgument( ETD->getTemplateParameters()->getParam(I)) && S.hasVisibleDefaultArgument( DTD->getTemplateParameters()->getParam(I))) return true; } } // VarDecl can have incomplete array types, prefer the one with more complete // array type. if (VarDecl *DVD = dyn_cast(DUnderlying)) { VarDecl *EVD = cast(EUnderlying); if (EVD->getType()->isIncompleteType() && !DVD->getType()->isIncompleteType()) { // Prefer the decl with a more complete type if visible. return S.isVisible(DVD); } return false; // Avoid picking up a newer decl, just because it was newer. } // For most kinds of declaration, it doesn't really matter which one we pick. if (!isa(DUnderlying) && !isa(DUnderlying)) { // If the existing declaration is hidden, prefer the new one. Otherwise, // keep what we've got. return !S.isVisible(Existing); } // Pick the newer declaration; it might have a more precise type. for (Decl *Prev = DUnderlying->getPreviousDecl(); Prev; Prev = Prev->getPreviousDecl()) if (Prev == EUnderlying) return true; return false; } /// Determine whether \p D can hide a tag declaration. static bool canHideTag(NamedDecl *D) { // C++ [basic.scope.declarative]p4: // Given a set of declarations in a single declarative region [...] // exactly one declaration shall declare a class name or enumeration name // that is not a typedef name and the other declarations shall all refer to // the same variable or enumerator, or all refer to functions and function // templates; in this case the class name or enumeration name is hidden. // C++ [basic.scope.hiding]p2: // A class name or enumeration name can be hidden by the name of a // variable, data member, function, or enumerator declared in the same // scope. D = D->getUnderlyingDecl(); return isa(D) || isa(D) || isa(D) || isa(D) || isa(D); } /// Resolves the result kind of this lookup. void LookupResult::resolveKind() { unsigned N = Decls.size(); // Fast case: no possible ambiguity. if (N == 0) { assert(ResultKind == NotFound || ResultKind == NotFoundInCurrentInstantiation); return; } // If there's a single decl, we need to examine it to decide what // kind of lookup this is. if (N == 1) { NamedDecl *D = (*Decls.begin())->getUnderlyingDecl(); if (isa(D)) ResultKind = FoundOverloaded; else if (isa(D)) ResultKind = FoundUnresolvedValue; return; } // Don't do any extra resolution if we've already resolved as ambiguous. if (ResultKind == Ambiguous) return; llvm::SmallDenseMap Unique; llvm::SmallDenseMap UniqueTypes; bool Ambiguous = false; bool HasTag = false, HasFunction = false; bool HasFunctionTemplate = false, HasUnresolved = false; NamedDecl *HasNonFunction = nullptr; llvm::SmallVector EquivalentNonFunctions; unsigned UniqueTagIndex = 0; unsigned I = 0; while (I < N) { NamedDecl *D = Decls[I]->getUnderlyingDecl(); D = cast(D->getCanonicalDecl()); // Ignore an invalid declaration unless it's the only one left. if (D->isInvalidDecl() && !(I == 0 && N == 1)) { Decls[I] = Decls[--N]; continue; } llvm::Optional ExistingI; // Redeclarations of types via typedef can occur both within a scope // and, through using declarations and directives, across scopes. There is // no ambiguity if they all refer to the same type, so unique based on the // canonical type. if (TypeDecl *TD = dyn_cast(D)) { QualType T = getSema().Context.getTypeDeclType(TD); auto UniqueResult = UniqueTypes.insert( std::make_pair(getSema().Context.getCanonicalType(T), I)); if (!UniqueResult.second) { // The type is not unique. ExistingI = UniqueResult.first->second; } } // For non-type declarations, check for a prior lookup result naming this // canonical declaration. if (!ExistingI) { auto UniqueResult = Unique.insert(std::make_pair(D, I)); if (!UniqueResult.second) { // We've seen this entity before. ExistingI = UniqueResult.first->second; } } if (ExistingI) { // This is not a unique lookup result. Pick one of the results and // discard the other. if (isPreferredLookupResult(getSema(), getLookupKind(), Decls[I], Decls[*ExistingI])) Decls[*ExistingI] = Decls[I]; Decls[I] = Decls[--N]; continue; } // Otherwise, do some decl type analysis and then continue. if (isa(D)) { HasUnresolved = true; } else if (isa(D)) { if (HasTag) Ambiguous = true; UniqueTagIndex = I; HasTag = true; } else if (isa(D)) { HasFunction = true; HasFunctionTemplate = true; } else if (isa(D)) { HasFunction = true; } else { if (HasNonFunction) { // If we're about to create an ambiguity between two declarations that // are equivalent, but one is an internal linkage declaration from one // module and the other is an internal linkage declaration from another // module, just skip it. if (getSema().isEquivalentInternalLinkageDeclaration(HasNonFunction, D)) { EquivalentNonFunctions.push_back(D); Decls[I] = Decls[--N]; continue; } Ambiguous = true; } HasNonFunction = D; } I++; } // C++ [basic.scope.hiding]p2: // A class name or enumeration name can be hidden by the name of // an object, function, or enumerator declared in the same // scope. If a class or enumeration name and an object, function, // or enumerator are declared in the same scope (in any order) // with the same name, the class or enumeration name is hidden // wherever the object, function, or enumerator name is visible. // But it's still an error if there are distinct tag types found, // even if they're not visible. (ref?) if (N > 1 && HideTags && HasTag && !Ambiguous && (HasFunction || HasNonFunction || HasUnresolved)) { NamedDecl *OtherDecl = Decls[UniqueTagIndex ? 0 : N - 1]; if (isa(Decls[UniqueTagIndex]->getUnderlyingDecl()) && getContextForScopeMatching(Decls[UniqueTagIndex])->Equals( getContextForScopeMatching(OtherDecl)) && canHideTag(OtherDecl)) Decls[UniqueTagIndex] = Decls[--N]; else Ambiguous = true; } // FIXME: This diagnostic should really be delayed until we're done with // the lookup result, in case the ambiguity is resolved by the caller. if (!EquivalentNonFunctions.empty() && !Ambiguous) getSema().diagnoseEquivalentInternalLinkageDeclarations( getNameLoc(), HasNonFunction, EquivalentNonFunctions); Decls.set_size(N); if (HasNonFunction && (HasFunction || HasUnresolved)) Ambiguous = true; if (Ambiguous) setAmbiguous(LookupResult::AmbiguousReference); else if (HasUnresolved) ResultKind = LookupResult::FoundUnresolvedValue; else if (N > 1 || HasFunctionTemplate) ResultKind = LookupResult::FoundOverloaded; else ResultKind = LookupResult::Found; } void LookupResult::addDeclsFromBasePaths(const CXXBasePaths &P) { CXXBasePaths::const_paths_iterator I, E; for (I = P.begin(), E = P.end(); I != E; ++I) for (DeclContext::lookup_iterator DI = I->Decls.begin(), DE = I->Decls.end(); DI != DE; ++DI) addDecl(*DI); } void LookupResult::setAmbiguousBaseSubobjects(CXXBasePaths &P) { Paths = new CXXBasePaths; Paths->swap(P); addDeclsFromBasePaths(*Paths); resolveKind(); setAmbiguous(AmbiguousBaseSubobjects); } void LookupResult::setAmbiguousBaseSubobjectTypes(CXXBasePaths &P) { Paths = new CXXBasePaths; Paths->swap(P); addDeclsFromBasePaths(*Paths); resolveKind(); setAmbiguous(AmbiguousBaseSubobjectTypes); } void LookupResult::print(raw_ostream &Out) { Out << Decls.size() << " result(s)"; if (isAmbiguous()) Out << ", ambiguous"; if (Paths) Out << ", base paths present"; for (iterator I = begin(), E = end(); I != E; ++I) { Out << "\n"; (*I)->print(Out, 2); } } LLVM_DUMP_METHOD void LookupResult::dump() { llvm::errs() << "lookup results for " << getLookupName().getAsString() << ":\n"; for (NamedDecl *D : *this) D->dump(); } /// \brief Lookup a builtin function, when name lookup would otherwise /// fail. static bool LookupBuiltin(Sema &S, LookupResult &R) { Sema::LookupNameKind NameKind = R.getLookupKind(); // If we didn't find a use of this identifier, and if the identifier // corresponds to a compiler builtin, create the decl object for the builtin // now, injecting it into translation unit scope, and return it. if (NameKind == Sema::LookupOrdinaryName || NameKind == Sema::LookupRedeclarationWithLinkage) { IdentifierInfo *II = R.getLookupName().getAsIdentifierInfo(); if (II) { if (S.getLangOpts().CPlusPlus && NameKind == Sema::LookupOrdinaryName) { if (II == S.getASTContext().getMakeIntegerSeqName()) { R.addDecl(S.getASTContext().getMakeIntegerSeqDecl()); return true; } else if (II == S.getASTContext().getTypePackElementName()) { R.addDecl(S.getASTContext().getTypePackElementDecl()); return true; } } // If this is a builtin on this (or all) targets, create the decl. if (unsigned BuiltinID = II->getBuiltinID()) { // In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined // library functions like 'malloc'. Instead, we'll just error. if ((S.getLangOpts().CPlusPlus || S.getLangOpts().OpenCL) && S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) return false; if (NamedDecl *D = S.LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S.TUScope, R.isForRedeclaration(), R.getNameLoc())) { R.addDecl(D); return true; } } } } return false; } /// \brief Determine whether we can declare a special member function within /// the class at this point. static bool CanDeclareSpecialMemberFunction(const CXXRecordDecl *Class) { // We need to have a definition for the class. if (!Class->getDefinition() || Class->isDependentContext()) return false; // We can't be in the middle of defining the class. return !Class->isBeingDefined(); } void Sema::ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class) { if (!CanDeclareSpecialMemberFunction(Class)) return; // If the default constructor has not yet been declared, do so now. if (Class->needsImplicitDefaultConstructor()) DeclareImplicitDefaultConstructor(Class); // If the copy constructor has not yet been declared, do so now. if (Class->needsImplicitCopyConstructor()) DeclareImplicitCopyConstructor(Class); // If the copy assignment operator has not yet been declared, do so now. if (Class->needsImplicitCopyAssignment()) DeclareImplicitCopyAssignment(Class); if (getLangOpts().CPlusPlus11) { // If the move constructor has not yet been declared, do so now. if (Class->needsImplicitMoveConstructor()) DeclareImplicitMoveConstructor(Class); // If the move assignment operator has not yet been declared, do so now. if (Class->needsImplicitMoveAssignment()) DeclareImplicitMoveAssignment(Class); } // If the destructor has not yet been declared, do so now. if (Class->needsImplicitDestructor()) DeclareImplicitDestructor(Class); } /// \brief Determine whether this is the name of an implicitly-declared /// special member function. static bool isImplicitlyDeclaredMemberFunctionName(DeclarationName Name) { switch (Name.getNameKind()) { case DeclarationName::CXXConstructorName: case DeclarationName::CXXDestructorName: return true; case DeclarationName::CXXOperatorName: return Name.getCXXOverloadedOperator() == OO_Equal; default: break; } return false; } /// \brief If there are any implicit member functions with the given name /// that need to be declared in the given declaration context, do so. static void DeclareImplicitMemberFunctionsWithName(Sema &S, DeclarationName Name, const DeclContext *DC) { if (!DC) return; switch (Name.getNameKind()) { case DeclarationName::CXXConstructorName: if (const CXXRecordDecl *Record = dyn_cast(DC)) if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) { CXXRecordDecl *Class = const_cast(Record); if (Record->needsImplicitDefaultConstructor()) S.DeclareImplicitDefaultConstructor(Class); if (Record->needsImplicitCopyConstructor()) S.DeclareImplicitCopyConstructor(Class); if (S.getLangOpts().CPlusPlus11 && Record->needsImplicitMoveConstructor()) S.DeclareImplicitMoveConstructor(Class); } break; case DeclarationName::CXXDestructorName: if (const CXXRecordDecl *Record = dyn_cast(DC)) if (Record->getDefinition() && Record->needsImplicitDestructor() && CanDeclareSpecialMemberFunction(Record)) S.DeclareImplicitDestructor(const_cast(Record)); break; case DeclarationName::CXXOperatorName: if (Name.getCXXOverloadedOperator() != OO_Equal) break; if (const CXXRecordDecl *Record = dyn_cast(DC)) { if (Record->getDefinition() && CanDeclareSpecialMemberFunction(Record)) { CXXRecordDecl *Class = const_cast(Record); if (Record->needsImplicitCopyAssignment()) S.DeclareImplicitCopyAssignment(Class); if (S.getLangOpts().CPlusPlus11 && Record->needsImplicitMoveAssignment()) S.DeclareImplicitMoveAssignment(Class); } } break; default: break; } } // Adds all qualifying matches for a name within a decl context to the // given lookup result. Returns true if any matches were found. static bool LookupDirect(Sema &S, LookupResult &R, const DeclContext *DC) { bool Found = false; // Lazily declare C++ special member functions. if (S.getLangOpts().CPlusPlus) DeclareImplicitMemberFunctionsWithName(S, R.getLookupName(), DC); // Perform lookup into this declaration context. DeclContext::lookup_result DR = DC->lookup(R.getLookupName()); for (DeclContext::lookup_iterator I = DR.begin(), E = DR.end(); I != E; ++I) { NamedDecl *D = *I; if ((D = R.getAcceptableDecl(D))) { R.addDecl(D); Found = true; } } if (!Found && DC->isTranslationUnit() && LookupBuiltin(S, R)) return true; if (R.getLookupName().getNameKind() != DeclarationName::CXXConversionFunctionName || R.getLookupName().getCXXNameType()->isDependentType() || !isa(DC)) return Found; // C++ [temp.mem]p6: // A specialization of a conversion function template is not found by // name lookup. Instead, any conversion function templates visible in the // context of the use are considered. [...] const CXXRecordDecl *Record = cast(DC); if (!Record->isCompleteDefinition()) return Found; for (CXXRecordDecl::conversion_iterator U = Record->conversion_begin(), UEnd = Record->conversion_end(); U != UEnd; ++U) { FunctionTemplateDecl *ConvTemplate = dyn_cast(*U); if (!ConvTemplate) continue; // When we're performing lookup for the purposes of redeclaration, just // add the conversion function template. When we deduce template // arguments for specializations, we'll end up unifying the return // type of the new declaration with the type of the function template. if (R.isForRedeclaration()) { R.addDecl(ConvTemplate); Found = true; continue; } // C++ [temp.mem]p6: // [...] For each such operator, if argument deduction succeeds // (14.9.2.3), the resulting specialization is used as if found by // name lookup. // // When referencing a conversion function for any purpose other than // a redeclaration (such that we'll be building an expression with the // result), perform template argument deduction and place the // specialization into the result set. We do this to avoid forcing all // callers to perform special deduction for conversion functions. TemplateDeductionInfo Info(R.getNameLoc()); FunctionDecl *Specialization = nullptr; const FunctionProtoType *ConvProto = ConvTemplate->getTemplatedDecl()->getType()->getAs(); assert(ConvProto && "Nonsensical conversion function template type"); // Compute the type of the function that we would expect the conversion // function to have, if it were to match the name given. // FIXME: Calling convention! FunctionProtoType::ExtProtoInfo EPI = ConvProto->getExtProtoInfo(); EPI.ExtInfo = EPI.ExtInfo.withCallingConv(CC_C); EPI.ExceptionSpec = EST_None; QualType ExpectedType = R.getSema().Context.getFunctionType(R.getLookupName().getCXXNameType(), None, EPI); // Perform template argument deduction against the type that we would // expect the function to have. if (R.getSema().DeduceTemplateArguments(ConvTemplate, nullptr, ExpectedType, Specialization, Info) == Sema::TDK_Success) { R.addDecl(Specialization); Found = true; } } return Found; } // Performs C++ unqualified lookup into the given file context. static bool CppNamespaceLookup(Sema &S, LookupResult &R, ASTContext &Context, DeclContext *NS, UnqualUsingDirectiveSet &UDirs) { assert(NS && NS->isFileContext() && "CppNamespaceLookup() requires namespace!"); // Perform direct name lookup into the LookupCtx. bool Found = LookupDirect(S, R, NS); // Perform direct name lookup into the namespaces nominated by the // using directives whose common ancestor is this namespace. for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(NS)) if (LookupDirect(S, R, UUE.getNominatedNamespace())) Found = true; R.resolveKind(); return Found; } static bool isNamespaceOrTranslationUnitScope(Scope *S) { if (DeclContext *Ctx = S->getEntity()) return Ctx->isFileContext(); return false; } // Find the next outer declaration context from this scope. This // routine actually returns the semantic outer context, which may // differ from the lexical context (encoded directly in the Scope // stack) when we are parsing a member of a class template. In this // case, the second element of the pair will be true, to indicate that // name lookup should continue searching in this semantic context when // it leaves the current template parameter scope. static std::pair findOuterContext(Scope *S) { DeclContext *DC = S->getEntity(); DeclContext *Lexical = nullptr; for (Scope *OuterS = S->getParent(); OuterS; OuterS = OuterS->getParent()) { if (OuterS->getEntity()) { Lexical = OuterS->getEntity(); break; } } // C++ [temp.local]p8: // In the definition of a member of a class template that appears // outside of the namespace containing the class template // definition, the name of a template-parameter hides the name of // a member of this namespace. // // Example: // // namespace N { // class C { }; // // template class B { // void f(T); // }; // } // // template void N::B::f(C) { // C b; // C is the template parameter, not N::C // } // // In this example, the lexical context we return is the // TranslationUnit, while the semantic context is the namespace N. if (!Lexical || !DC || !S->getParent() || !S->getParent()->isTemplateParamScope()) return std::make_pair(Lexical, false); // Find the outermost template parameter scope. // For the example, this is the scope for the template parameters of // template. Scope *OutermostTemplateScope = S->getParent(); while (OutermostTemplateScope->getParent() && OutermostTemplateScope->getParent()->isTemplateParamScope()) OutermostTemplateScope = OutermostTemplateScope->getParent(); // Find the namespace context in which the original scope occurs. In // the example, this is namespace N. DeclContext *Semantic = DC; while (!Semantic->isFileContext()) Semantic = Semantic->getParent(); // Find the declaration context just outside of the template // parameter scope. This is the context in which the template is // being lexically declaration (a namespace context). In the // example, this is the global scope. if (Lexical->isFileContext() && !Lexical->Equals(Semantic) && Lexical->Encloses(Semantic)) return std::make_pair(Semantic, true); return std::make_pair(Lexical, false); } namespace { /// An RAII object to specify that we want to find block scope extern /// declarations. struct FindLocalExternScope { FindLocalExternScope(LookupResult &R) : R(R), OldFindLocalExtern(R.getIdentifierNamespace() & Decl::IDNS_LocalExtern) { R.setFindLocalExtern(R.getIdentifierNamespace() & Decl::IDNS_Ordinary); } void restore() { R.setFindLocalExtern(OldFindLocalExtern); } ~FindLocalExternScope() { restore(); } LookupResult &R; bool OldFindLocalExtern; }; } // end anonymous namespace bool Sema::CppLookupName(LookupResult &R, Scope *S) { assert(getLangOpts().CPlusPlus && "Can perform only C++ lookup"); DeclarationName Name = R.getLookupName(); Sema::LookupNameKind NameKind = R.getLookupKind(); // If this is the name of an implicitly-declared special member function, // go through the scope stack to implicitly declare if (isImplicitlyDeclaredMemberFunctionName(Name)) { for (Scope *PreS = S; PreS; PreS = PreS->getParent()) if (DeclContext *DC = PreS->getEntity()) DeclareImplicitMemberFunctionsWithName(*this, Name, DC); } // Implicitly declare member functions with the name we're looking for, if in // fact we are in a scope where it matters. Scope *Initial = S; IdentifierResolver::iterator I = IdResolver.begin(Name), IEnd = IdResolver.end(); // First we lookup local scope. // We don't consider using-directives, as per 7.3.4.p1 [namespace.udir] // ...During unqualified name lookup (3.4.1), the names appear as if // they were declared in the nearest enclosing namespace which contains // both the using-directive and the nominated namespace. // [Note: in this context, "contains" means "contains directly or // indirectly". // // For example: // namespace A { int i; } // void foo() { // int i; // { // using namespace A; // ++i; // finds local 'i', A::i appears at global scope // } // } // UnqualUsingDirectiveSet UDirs; bool VisitedUsingDirectives = false; bool LeftStartingScope = false; DeclContext *OutsideOfTemplateParamDC = nullptr; // When performing a scope lookup, we want to find local extern decls. FindLocalExternScope FindLocals(R); for (; S && !isNamespaceOrTranslationUnitScope(S); S = S->getParent()) { DeclContext *Ctx = S->getEntity(); bool SearchNamespaceScope = true; // Check whether the IdResolver has anything in this scope. for (; I != IEnd && S->isDeclScope(*I); ++I) { if (NamedDecl *ND = R.getAcceptableDecl(*I)) { if (NameKind == LookupRedeclarationWithLinkage && !(*I)->isTemplateParameter()) { // If it's a template parameter, we still find it, so we can diagnose // the invalid redeclaration. // Determine whether this (or a previous) declaration is // out-of-scope. if (!LeftStartingScope && !Initial->isDeclScope(*I)) LeftStartingScope = true; // If we found something outside of our starting scope that // does not have linkage, skip it. if (LeftStartingScope && !((*I)->hasLinkage())) { R.setShadowed(); continue; } } else { // We found something in this scope, we should not look at the // namespace scope SearchNamespaceScope = false; } R.addDecl(ND); } } if (!SearchNamespaceScope) { R.resolveKind(); if (S->isClassScope()) if (CXXRecordDecl *Record = dyn_cast_or_null(Ctx)) R.setNamingClass(Record); return true; } if (NameKind == LookupLocalFriendName && !S->isClassScope()) { // C++11 [class.friend]p11: // If a friend declaration appears in a local class and the name // specified is an unqualified name, a prior declaration is // looked up without considering scopes that are outside the // innermost enclosing non-class scope. return false; } if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && S->getParent() && !S->getParent()->isTemplateParamScope()) { // We've just searched the last template parameter scope and // found nothing, so look into the contexts between the // lexical and semantic declaration contexts returned by // findOuterContext(). This implements the name lookup behavior // of C++ [temp.local]p8. Ctx = OutsideOfTemplateParamDC; OutsideOfTemplateParamDC = nullptr; } if (Ctx) { DeclContext *OuterCtx; bool SearchAfterTemplateScope; std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); if (SearchAfterTemplateScope) OutsideOfTemplateParamDC = OuterCtx; for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { // We do not directly look into transparent contexts, since // those entities will be found in the nearest enclosing // non-transparent context. if (Ctx->isTransparentContext()) continue; // We do not look directly into function or method contexts, // since all of the local variables and parameters of the // function/method are present within the Scope. if (Ctx->isFunctionOrMethod()) { // If we have an Objective-C instance method, look for ivars // in the corresponding interface. if (ObjCMethodDecl *Method = dyn_cast(Ctx)) { if (Method->isInstanceMethod() && Name.getAsIdentifierInfo()) if (ObjCInterfaceDecl *Class = Method->getClassInterface()) { ObjCInterfaceDecl *ClassDeclared; if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable( Name.getAsIdentifierInfo(), ClassDeclared)) { if (NamedDecl *ND = R.getAcceptableDecl(Ivar)) { R.addDecl(ND); R.resolveKind(); return true; } } } } continue; } // If this is a file context, we need to perform unqualified name // lookup considering using directives. if (Ctx->isFileContext()) { // If we haven't handled using directives yet, do so now. if (!VisitedUsingDirectives) { // Add using directives from this context up to the top level. for (DeclContext *UCtx = Ctx; UCtx; UCtx = UCtx->getParent()) { if (UCtx->isTransparentContext()) continue; UDirs.visit(UCtx, UCtx); } // Find the innermost file scope, so we can add using directives // from local scopes. Scope *InnermostFileScope = S; while (InnermostFileScope && !isNamespaceOrTranslationUnitScope(InnermostFileScope)) InnermostFileScope = InnermostFileScope->getParent(); UDirs.visitScopeChain(Initial, InnermostFileScope); UDirs.done(); VisitedUsingDirectives = true; } if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) { R.resolveKind(); return true; } continue; } // Perform qualified name lookup into this context. // FIXME: In some cases, we know that every name that could be found by // this qualified name lookup will also be on the identifier chain. For // example, inside a class without any base classes, we never need to // perform qualified lookup because all of the members are on top of the // identifier chain. if (LookupQualifiedName(R, Ctx, /*InUnqualifiedLookup=*/true)) return true; } } } // Stop if we ran out of scopes. // FIXME: This really, really shouldn't be happening. if (!S) return false; // If we are looking for members, no need to look into global/namespace scope. if (NameKind == LookupMemberName) return false; // Collect UsingDirectiveDecls in all scopes, and recursively all // nominated namespaces by those using-directives. // // FIXME: Cache this sorted list in Scope structure, and DeclContext, so we // don't build it for each lookup! if (!VisitedUsingDirectives) { UDirs.visitScopeChain(Initial, S); UDirs.done(); } // If we're not performing redeclaration lookup, do not look for local // extern declarations outside of a function scope. if (!R.isForRedeclaration()) FindLocals.restore(); // Lookup namespace scope, and global scope. // Unqualified name lookup in C++ requires looking into scopes // that aren't strictly lexical, and therefore we walk through the // context as well as walking through the scopes. for (; S; S = S->getParent()) { // Check whether the IdResolver has anything in this scope. bool Found = false; for (; I != IEnd && S->isDeclScope(*I); ++I) { if (NamedDecl *ND = R.getAcceptableDecl(*I)) { // We found something. Look for anything else in our scope // with this same name and in an acceptable identifier // namespace, so that we can construct an overload set if we // need to. Found = true; R.addDecl(ND); } } if (Found && S->isTemplateParamScope()) { R.resolveKind(); return true; } DeclContext *Ctx = S->getEntity(); if (!Ctx && S->isTemplateParamScope() && OutsideOfTemplateParamDC && S->getParent() && !S->getParent()->isTemplateParamScope()) { // We've just searched the last template parameter scope and // found nothing, so look into the contexts between the // lexical and semantic declaration contexts returned by // findOuterContext(). This implements the name lookup behavior // of C++ [temp.local]p8. Ctx = OutsideOfTemplateParamDC; OutsideOfTemplateParamDC = nullptr; } if (Ctx) { DeclContext *OuterCtx; bool SearchAfterTemplateScope; std::tie(OuterCtx, SearchAfterTemplateScope) = findOuterContext(S); if (SearchAfterTemplateScope) OutsideOfTemplateParamDC = OuterCtx; for (; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { // We do not directly look into transparent contexts, since // those entities will be found in the nearest enclosing // non-transparent context. if (Ctx->isTransparentContext()) continue; // If we have a context, and it's not a context stashed in the // template parameter scope for an out-of-line definition, also // look into that context. if (!(Found && S && S->isTemplateParamScope())) { assert(Ctx->isFileContext() && "We should have been looking only at file context here already."); // Look into context considering using-directives. if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) Found = true; } if (Found) { R.resolveKind(); return true; } if (R.isForRedeclaration() && !Ctx->isTransparentContext()) return false; } } if (R.isForRedeclaration() && Ctx && !Ctx->isTransparentContext()) return false; } return !R.empty(); } /// \brief Find the declaration that a class temploid member specialization was /// instantiated from, or the member itself if it is an explicit specialization. static Decl *getInstantiatedFrom(Decl *D, MemberSpecializationInfo *MSInfo) { return MSInfo->isExplicitSpecialization() ? D : MSInfo->getInstantiatedFrom(); } Module *Sema::getOwningModule(Decl *Entity) { // If it's imported, grab its owning module. Module *M = Entity->getImportedOwningModule(); if (M || !isa(Entity) || !cast(Entity)->isHidden()) return M; assert(!Entity->isFromASTFile() && "hidden entity from AST file has no owning module"); if (!getLangOpts().ModulesLocalVisibility) { // If we're not tracking visibility locally, the only way a declaration // can be hidden and local is if it's hidden because it's parent is (for // instance, maybe this is a lazily-declared special member of an imported // class). auto *Parent = cast(Entity->getDeclContext()); assert(Parent->isHidden() && "unexpectedly hidden decl"); return getOwningModule(Parent); } // It's local and hidden; grab or compute its owning module. M = Entity->getLocalOwningModule(); if (M) return M; if (auto *Containing = PP.getModuleContainingLocation(Entity->getLocation())) { M = Containing; } else if (Entity->isInvalidDecl() || Entity->getLocation().isInvalid()) { // Don't bother tracking visibility for invalid declarations with broken // locations. cast(Entity)->setHidden(false); } else { // We need to assign a module to an entity that exists outside of any // module, so that we can hide it from modules that we textually enter. // Invent a fake module for all such entities. if (!CachedFakeTopLevelModule) { CachedFakeTopLevelModule = PP.getHeaderSearchInfo().getModuleMap().findOrCreateModule( "", nullptr, false, false).first; auto &SrcMgr = PP.getSourceManager(); SourceLocation StartLoc = SrcMgr.getLocForStartOfFile(SrcMgr.getMainFileID()); auto &TopLevel = VisibleModulesStack.empty() ? VisibleModules : VisibleModulesStack[0]; TopLevel.setVisible(CachedFakeTopLevelModule, StartLoc); } M = CachedFakeTopLevelModule; } if (M) Entity->setLocalOwningModule(M); return M; } void Sema::makeMergedDefinitionVisible(NamedDecl *ND, SourceLocation Loc) { if (auto *M = PP.getModuleContainingLocation(Loc)) Context.mergeDefinitionIntoModule(ND, M); else // We're not building a module; just make the definition visible. ND->setHidden(false); // If ND is a template declaration, make the template parameters // visible too. They're not (necessarily) within a mergeable DeclContext. if (auto *TD = dyn_cast(ND)) for (auto *Param : *TD->getTemplateParameters()) makeMergedDefinitionVisible(Param, Loc); } /// \brief Find the module in which the given declaration was defined. static Module *getDefiningModule(Sema &S, Decl *Entity) { if (FunctionDecl *FD = dyn_cast(Entity)) { // If this function was instantiated from a template, the defining module is // the module containing the pattern. if (FunctionDecl *Pattern = FD->getTemplateInstantiationPattern()) Entity = Pattern; } else if (CXXRecordDecl *RD = dyn_cast(Entity)) { if (CXXRecordDecl *Pattern = RD->getTemplateInstantiationPattern()) Entity = Pattern; } else if (EnumDecl *ED = dyn_cast(Entity)) { if (MemberSpecializationInfo *MSInfo = ED->getMemberSpecializationInfo()) Entity = getInstantiatedFrom(ED, MSInfo); } else if (VarDecl *VD = dyn_cast(Entity)) { // FIXME: Map from variable template specializations back to the template. if (MemberSpecializationInfo *MSInfo = VD->getMemberSpecializationInfo()) Entity = getInstantiatedFrom(VD, MSInfo); } // Walk up to the containing context. That might also have been instantiated // from a template. DeclContext *Context = Entity->getDeclContext(); if (Context->isFileContext()) return S.getOwningModule(Entity); return getDefiningModule(S, cast(Context)); } llvm::DenseSet &Sema::getLookupModules() { unsigned N = ActiveTemplateInstantiations.size(); for (unsigned I = ActiveTemplateInstantiationLookupModules.size(); I != N; ++I) { Module *M = getDefiningModule(*this, ActiveTemplateInstantiations[I].Entity); if (M && !LookupModulesCache.insert(M).second) M = nullptr; ActiveTemplateInstantiationLookupModules.push_back(M); } return LookupModulesCache; } bool Sema::hasVisibleMergedDefinition(NamedDecl *Def) { for (Module *Merged : Context.getModulesWithMergedDefinition(Def)) if (isModuleVisible(Merged)) return true; return false; } template static bool hasVisibleDefaultArgument(Sema &S, const ParmDecl *D, llvm::SmallVectorImpl *Modules) { if (!D->hasDefaultArgument()) return false; while (D) { auto &DefaultArg = D->getDefaultArgStorage(); if (!DefaultArg.isInherited() && S.isVisible(D)) return true; if (!DefaultArg.isInherited() && Modules) { auto *NonConstD = const_cast(D); Modules->push_back(S.getOwningModule(NonConstD)); const auto &Merged = S.Context.getModulesWithMergedDefinition(NonConstD); Modules->insert(Modules->end(), Merged.begin(), Merged.end()); } // If there was a previous default argument, maybe its parameter is visible. D = DefaultArg.getInheritedFrom(); } return false; } bool Sema::hasVisibleDefaultArgument(const NamedDecl *D, llvm::SmallVectorImpl *Modules) { if (auto *P = dyn_cast(D)) return ::hasVisibleDefaultArgument(*this, P, Modules); if (auto *P = dyn_cast(D)) return ::hasVisibleDefaultArgument(*this, P, Modules); return ::hasVisibleDefaultArgument(*this, cast(D), Modules); } bool Sema::hasVisibleMemberSpecialization( const NamedDecl *D, llvm::SmallVectorImpl *Modules) { assert(isa(D->getDeclContext()) && "not a member specialization"); for (auto *Redecl : D->redecls()) { // If the specialization is declared at namespace scope, then it's a member // specialization declaration. If it's lexically inside the class // definition then it was instantiated. // // FIXME: This is a hack. There should be a better way to determine this. // FIXME: What about MS-style explicit specializations declared within a // class definition? if (Redecl->getLexicalDeclContext()->isFileContext()) { auto *NonConstR = const_cast(cast(Redecl)); if (isVisible(NonConstR)) return true; if (Modules) { Modules->push_back(getOwningModule(NonConstR)); const auto &Merged = Context.getModulesWithMergedDefinition(NonConstR); Modules->insert(Modules->end(), Merged.begin(), Merged.end()); } } } return false; } /// \brief Determine whether a declaration is visible to name lookup. /// /// This routine determines whether the declaration D is visible in the current /// lookup context, taking into account the current template instantiation /// stack. During template instantiation, a declaration is visible if it is /// visible from a module containing any entity on the template instantiation /// path (by instantiating a template, you allow it to see the declarations that /// your module can see, including those later on in your module). bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) { assert(D->isHidden() && "should not call this: not in slow case"); Module *DeclModule = nullptr; if (SemaRef.getLangOpts().ModulesLocalVisibility) { DeclModule = SemaRef.getOwningModule(D); if (!DeclModule) { // getOwningModule() may have decided the declaration should not be hidden. assert(!D->isHidden() && "hidden decl not from a module"); return true; } // If the owning module is visible, and the decl is not module private, // then the decl is visible too. (Module private is ignored within the same // top-level module.) if ((!D->isFromASTFile() || !D->isModulePrivate()) && (SemaRef.isModuleVisible(DeclModule) || SemaRef.hasVisibleMergedDefinition(D))) return true; } // If this declaration is not at namespace scope nor module-private, // then it is visible if its lexical parent has a visible definition. DeclContext *DC = D->getLexicalDeclContext(); if (!D->isModulePrivate() && DC && !DC->isFileContext() && !isa(DC)) { // For a parameter, check whether our current template declaration's // lexical context is visible, not whether there's some other visible // definition of it, because parameters aren't "within" the definition. if ((D->isTemplateParameter() || isa(D)) ? isVisible(SemaRef, cast(DC)) : SemaRef.hasVisibleDefinition(cast(DC))) { if (SemaRef.ActiveTemplateInstantiations.empty() && // FIXME: Do something better in this case. !SemaRef.getLangOpts().ModulesLocalVisibility) { // Cache the fact that this declaration is implicitly visible because // its parent has a visible definition. D->setHidden(false); } return true; } return false; } // Find the extra places where we need to look. llvm::DenseSet &LookupModules = SemaRef.getLookupModules(); if (LookupModules.empty()) return false; if (!DeclModule) { DeclModule = SemaRef.getOwningModule(D); assert(DeclModule && "hidden decl not from a module"); } // If our lookup set contains the decl's module, it's visible. if (LookupModules.count(DeclModule)) return true; // If the declaration isn't exported, it's not visible in any other module. if (D->isModulePrivate()) return false; // Check whether DeclModule is transitively exported to an import of // the lookup set. return std::any_of(LookupModules.begin(), LookupModules.end(), [&](Module *M) { return M->isModuleVisible(DeclModule); }); } bool Sema::isVisibleSlow(const NamedDecl *D) { return LookupResult::isVisible(*this, const_cast(D)); } bool Sema::shouldLinkPossiblyHiddenDecl(LookupResult &R, const NamedDecl *New) { for (auto *D : R) { if (isVisible(D)) return true; } return New->isExternallyVisible(); } /// \brief Retrieve the visible declaration corresponding to D, if any. /// /// This routine determines whether the declaration D is visible in the current /// module, with the current imports. If not, it checks whether any /// redeclaration of D is visible, and if so, returns that declaration. /// /// \returns D, or a visible previous declaration of D, whichever is more recent /// and visible. If no declaration of D is visible, returns null. static NamedDecl *findAcceptableDecl(Sema &SemaRef, NamedDecl *D) { assert(!LookupResult::isVisible(SemaRef, D) && "not in slow case"); for (auto RD : D->redecls()) { // Don't bother with extra checks if we already know this one isn't visible. if (RD == D) continue; auto ND = cast(RD); // FIXME: This is wrong in the case where the previous declaration is not // visible in the same scope as D. This needs to be done much more // carefully. if (LookupResult::isVisible(SemaRef, ND)) return ND; } return nullptr; } bool Sema::hasVisibleDeclarationSlow(const NamedDecl *D, llvm::SmallVectorImpl *Modules) { assert(!isVisible(D) && "not in slow case"); for (auto *Redecl : D->redecls()) { auto *NonConstR = const_cast(cast(Redecl)); if (isVisible(NonConstR)) return true; if (Modules) { Modules->push_back(getOwningModule(NonConstR)); const auto &Merged = Context.getModulesWithMergedDefinition(NonConstR); Modules->insert(Modules->end(), Merged.begin(), Merged.end()); } } return false; } NamedDecl *LookupResult::getAcceptableDeclSlow(NamedDecl *D) const { if (auto *ND = dyn_cast(D)) { // Namespaces are a bit of a special case: we expect there to be a lot of // redeclarations of some namespaces, all declarations of a namespace are // essentially interchangeable, all declarations are found by name lookup // if any is, and namespaces are never looked up during template // instantiation. So we benefit from caching the check in this case, and // it is correct to do so. auto *Key = ND->getCanonicalDecl(); if (auto *Acceptable = getSema().VisibleNamespaceCache.lookup(Key)) return Acceptable; auto *Acceptable = isVisible(getSema(), Key) ? Key : findAcceptableDecl(getSema(), Key); if (Acceptable) getSema().VisibleNamespaceCache.insert(std::make_pair(Key, Acceptable)); return Acceptable; } return findAcceptableDecl(getSema(), D); } /// @brief Perform unqualified name lookup starting from a given /// scope. /// /// Unqualified name lookup (C++ [basic.lookup.unqual], C99 6.2.1) is /// used to find names within the current scope. For example, 'x' in /// @code /// int x; /// int f() { /// return x; // unqualified name look finds 'x' in the global scope /// } /// @endcode /// /// Different lookup criteria can find different names. For example, a /// particular scope can have both a struct and a function of the same /// name, and each can be found by certain lookup criteria. For more /// information about lookup criteria, see the documentation for the /// class LookupCriteria. /// /// @param S The scope from which unqualified name lookup will /// begin. If the lookup criteria permits, name lookup may also search /// in the parent scopes. /// /// @param [in,out] R Specifies the lookup to perform (e.g., the name to /// look up and the lookup kind), and is updated with the results of lookup /// including zero or more declarations and possibly additional information /// used to diagnose ambiguities. /// /// @returns \c true if lookup succeeded and false otherwise. bool Sema::LookupName(LookupResult &R, Scope *S, bool AllowBuiltinCreation) { DeclarationName Name = R.getLookupName(); if (!Name) return false; LookupNameKind NameKind = R.getLookupKind(); if (!getLangOpts().CPlusPlus) { // Unqualified name lookup in C/Objective-C is purely lexical, so // search in the declarations attached to the name. if (NameKind == Sema::LookupRedeclarationWithLinkage) { // Find the nearest non-transparent declaration scope. while (!(S->getFlags() & Scope::DeclScope) || (S->getEntity() && S->getEntity()->isTransparentContext())) S = S->getParent(); } // When performing a scope lookup, we want to find local extern decls. FindLocalExternScope FindLocals(R); // Scan up the scope chain looking for a decl that matches this // identifier that is in the appropriate namespace. This search // should not take long, as shadowing of names is uncommon, and // deep shadowing is extremely uncommon. bool LeftStartingScope = false; for (IdentifierResolver::iterator I = IdResolver.begin(Name), IEnd = IdResolver.end(); I != IEnd; ++I) if (NamedDecl *D = R.getAcceptableDecl(*I)) { if (NameKind == LookupRedeclarationWithLinkage) { // Determine whether this (or a previous) declaration is // out-of-scope. if (!LeftStartingScope && !S->isDeclScope(*I)) LeftStartingScope = true; // If we found something outside of our starting scope that // does not have linkage, skip it. if (LeftStartingScope && !((*I)->hasLinkage())) { R.setShadowed(); continue; } } else if (NameKind == LookupObjCImplicitSelfParam && !isa(*I)) continue; R.addDecl(D); // Check whether there are any other declarations with the same name // and in the same scope. if (I != IEnd) { // Find the scope in which this declaration was declared (if it // actually exists in a Scope). while (S && !S->isDeclScope(D)) S = S->getParent(); // If the scope containing the declaration is the translation unit, // then we'll need to perform our checks based on the matching // DeclContexts rather than matching scopes. if (S && isNamespaceOrTranslationUnitScope(S)) S = nullptr; // Compute the DeclContext, if we need it. DeclContext *DC = nullptr; if (!S) DC = (*I)->getDeclContext()->getRedeclContext(); IdentifierResolver::iterator LastI = I; for (++LastI; LastI != IEnd; ++LastI) { if (S) { // Match based on scope. if (!S->isDeclScope(*LastI)) break; } else { // Match based on DeclContext. DeclContext *LastDC = (*LastI)->getDeclContext()->getRedeclContext(); if (!LastDC->Equals(DC)) break; } // If the declaration is in the right namespace and visible, add it. if (NamedDecl *LastD = R.getAcceptableDecl(*LastI)) R.addDecl(LastD); } R.resolveKind(); } return true; } } else { // Perform C++ unqualified name lookup. if (CppLookupName(R, S)) return true; } // If we didn't find a use of this identifier, and if the identifier // corresponds to a compiler builtin, create the decl object for the builtin // now, injecting it into translation unit scope, and return it. if (AllowBuiltinCreation && LookupBuiltin(*this, R)) return true; // If we didn't find a use of this identifier, the ExternalSource // may be able to handle the situation. // Note: some lookup failures are expected! // See e.g. R.isForRedeclaration(). return (ExternalSource && ExternalSource->LookupUnqualified(R, S)); } /// @brief Perform qualified name lookup in the namespaces nominated by /// using directives by the given context. /// /// C++98 [namespace.qual]p2: /// Given X::m (where X is a user-declared namespace), or given \::m /// (where X is the global namespace), let S be the set of all /// declarations of m in X and in the transitive closure of all /// namespaces nominated by using-directives in X and its used /// namespaces, except that using-directives are ignored in any /// namespace, including X, directly containing one or more /// declarations of m. No namespace is searched more than once in /// the lookup of a name. If S is the empty set, the program is /// ill-formed. Otherwise, if S has exactly one member, or if the /// context of the reference is a using-declaration /// (namespace.udecl), S is the required set of declarations of /// m. Otherwise if the use of m is not one that allows a unique /// declaration to be chosen from S, the program is ill-formed. /// /// C++98 [namespace.qual]p5: /// During the lookup of a qualified namespace member name, if the /// lookup finds more than one declaration of the member, and if one /// declaration introduces a class name or enumeration name and the /// other declarations either introduce the same object, the same /// enumerator or a set of functions, the non-type name hides the /// class or enumeration name if and only if the declarations are /// from the same namespace; otherwise (the declarations are from /// different namespaces), the program is ill-formed. static bool LookupQualifiedNameInUsingDirectives(Sema &S, LookupResult &R, DeclContext *StartDC) { assert(StartDC->isFileContext() && "start context is not a file context"); DeclContext::udir_range UsingDirectives = StartDC->using_directives(); if (UsingDirectives.begin() == UsingDirectives.end()) return false; // We have at least added all these contexts to the queue. llvm::SmallPtrSet Visited; Visited.insert(StartDC); // We have not yet looked into these namespaces, much less added // their "using-children" to the queue. SmallVector Queue; // We have already looked into the initial namespace; seed the queue // with its using-children. for (auto *I : UsingDirectives) { NamespaceDecl *ND = I->getNominatedNamespace()->getOriginalNamespace(); if (Visited.insert(ND).second) Queue.push_back(ND); } // The easiest way to implement the restriction in [namespace.qual]p5 // is to check whether any of the individual results found a tag // and, if so, to declare an ambiguity if the final result is not // a tag. bool FoundTag = false; bool FoundNonTag = false; LookupResult LocalR(LookupResult::Temporary, R); bool Found = false; while (!Queue.empty()) { NamespaceDecl *ND = Queue.pop_back_val(); // We go through some convolutions here to avoid copying results // between LookupResults. bool UseLocal = !R.empty(); LookupResult &DirectR = UseLocal ? LocalR : R; bool FoundDirect = LookupDirect(S, DirectR, ND); if (FoundDirect) { // First do any local hiding. DirectR.resolveKind(); // If the local result is a tag, remember that. if (DirectR.isSingleTagDecl()) FoundTag = true; else FoundNonTag = true; // Append the local results to the total results if necessary. if (UseLocal) { R.addAllDecls(LocalR); LocalR.clear(); } } // If we find names in this namespace, ignore its using directives. if (FoundDirect) { Found = true; continue; } for (auto I : ND->using_directives()) { NamespaceDecl *Nom = I->getNominatedNamespace(); if (Visited.insert(Nom).second) Queue.push_back(Nom); } } if (Found) { if (FoundTag && FoundNonTag) R.setAmbiguousQualifiedTagHiding(); else R.resolveKind(); } return Found; } /// \brief Callback that looks for any member of a class with the given name. static bool LookupAnyMember(const CXXBaseSpecifier *Specifier, CXXBasePath &Path, DeclarationName Name) { RecordDecl *BaseRecord = Specifier->getType()->getAs()->getDecl(); Path.Decls = BaseRecord->lookup(Name); return !Path.Decls.empty(); } /// \brief Determine whether the given set of member declarations contains only /// static members, nested types, and enumerators. template static bool HasOnlyStaticMembers(InputIterator First, InputIterator Last) { Decl *D = (*First)->getUnderlyingDecl(); if (isa(D) || isa(D) || isa(D)) return true; if (isa(D)) { // Determine whether all of the methods are static. bool AllMethodsAreStatic = true; for(; First != Last; ++First) { D = (*First)->getUnderlyingDecl(); if (!isa(D)) { assert(isa(D) && "Non-function must be a tag decl"); break; } if (!cast(D)->isStatic()) { AllMethodsAreStatic = false; break; } } if (AllMethodsAreStatic) return true; } return false; } /// \brief Perform qualified name lookup into a given context. /// /// Qualified name lookup (C++ [basic.lookup.qual]) is used to find /// names when the context of those names is explicit specified, e.g., /// "std::vector" or "x->member", or as part of unqualified name lookup. /// /// Different lookup criteria can find different names. For example, a /// particular scope can have both a struct and a function of the same /// name, and each can be found by certain lookup criteria. For more /// information about lookup criteria, see the documentation for the /// class LookupCriteria. /// /// \param R captures both the lookup criteria and any lookup results found. /// /// \param LookupCtx The context in which qualified name lookup will /// search. If the lookup criteria permits, name lookup may also search /// in the parent contexts or (for C++ classes) base classes. /// /// \param InUnqualifiedLookup true if this is qualified name lookup that /// occurs as part of unqualified name lookup. /// /// \returns true if lookup succeeded, false if it failed. bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, bool InUnqualifiedLookup) { assert(LookupCtx && "Sema::LookupQualifiedName requires a lookup context"); if (!R.getLookupName()) return false; // Make sure that the declaration context is complete. assert((!isa(LookupCtx) || LookupCtx->isDependentContext() || cast(LookupCtx)->isCompleteDefinition() || cast(LookupCtx)->isBeingDefined()) && "Declaration context must already be complete!"); struct QualifiedLookupInScope { bool oldVal; DeclContext *Context; // Set flag in DeclContext informing debugger that we're looking for qualified name QualifiedLookupInScope(DeclContext *ctx) : Context(ctx) { oldVal = ctx->setUseQualifiedLookup(); } ~QualifiedLookupInScope() { Context->setUseQualifiedLookup(oldVal); } } QL(LookupCtx); if (LookupDirect(*this, R, LookupCtx)) { R.resolveKind(); if (isa(LookupCtx)) R.setNamingClass(cast(LookupCtx)); return true; } // Don't descend into implied contexts for redeclarations. // C++98 [namespace.qual]p6: // In a declaration for a namespace member in which the // declarator-id is a qualified-id, given that the qualified-id // for the namespace member has the form // nested-name-specifier unqualified-id // the unqualified-id shall name a member of the namespace // designated by the nested-name-specifier. // See also [class.mfct]p5 and [class.static.data]p2. if (R.isForRedeclaration()) return false; // If this is a namespace, look it up in the implied namespaces. if (LookupCtx->isFileContext()) return LookupQualifiedNameInUsingDirectives(*this, R, LookupCtx); // If this isn't a C++ class, we aren't allowed to look into base // classes, we're done. CXXRecordDecl *LookupRec = dyn_cast(LookupCtx); if (!LookupRec || !LookupRec->getDefinition()) return false; // If we're performing qualified name lookup into a dependent class, // then we are actually looking into a current instantiation. If we have any // dependent base classes, then we either have to delay lookup until // template instantiation time (at which point all bases will be available) // or we have to fail. if (!InUnqualifiedLookup && LookupRec->isDependentContext() && LookupRec->hasAnyDependentBases()) { R.setNotFoundInCurrentInstantiation(); return false; } // Perform lookup into our base classes. CXXBasePaths Paths; Paths.setOrigin(LookupRec); // Look for this member in our base classes bool (*BaseCallback)(const CXXBaseSpecifier *Specifier, CXXBasePath &Path, DeclarationName Name) = nullptr; switch (R.getLookupKind()) { case LookupObjCImplicitSelfParam: case LookupOrdinaryName: case LookupMemberName: case LookupRedeclarationWithLinkage: case LookupLocalFriendName: BaseCallback = &CXXRecordDecl::FindOrdinaryMember; break; case LookupTagName: BaseCallback = &CXXRecordDecl::FindTagMember; break; case LookupAnyName: BaseCallback = &LookupAnyMember; break; case LookupOMPReductionName: BaseCallback = &CXXRecordDecl::FindOMPReductionMember; break; case LookupUsingDeclName: // This lookup is for redeclarations only. case LookupOperatorName: case LookupNamespaceName: case LookupObjCProtocolName: case LookupLabel: // These lookups will never find a member in a C++ class (or base class). return false; case LookupNestedNameSpecifierName: BaseCallback = &CXXRecordDecl::FindNestedNameSpecifierMember; break; } DeclarationName Name = R.getLookupName(); if (!LookupRec->lookupInBases( [=](const CXXBaseSpecifier *Specifier, CXXBasePath &Path) { return BaseCallback(Specifier, Path, Name); }, Paths)) return false; R.setNamingClass(LookupRec); // C++ [class.member.lookup]p2: // [...] If the resulting set of declarations are not all from // sub-objects of the same type, or the set has a nonstatic member // and includes members from distinct sub-objects, there is an // ambiguity and the program is ill-formed. Otherwise that set is // the result of the lookup. QualType SubobjectType; int SubobjectNumber = 0; AccessSpecifier SubobjectAccess = AS_none; for (CXXBasePaths::paths_iterator Path = Paths.begin(), PathEnd = Paths.end(); Path != PathEnd; ++Path) { const CXXBasePathElement &PathElement = Path->back(); // Pick the best (i.e. most permissive i.e. numerically lowest) access // across all paths. SubobjectAccess = std::min(SubobjectAccess, Path->Access); // Determine whether we're looking at a distinct sub-object or not. if (SubobjectType.isNull()) { // This is the first subobject we've looked at. Record its type. SubobjectType = Context.getCanonicalType(PathElement.Base->getType()); SubobjectNumber = PathElement.SubobjectNumber; continue; } if (SubobjectType != Context.getCanonicalType(PathElement.Base->getType())) { // We found members of the given name in two subobjects of // different types. If the declaration sets aren't the same, this // lookup is ambiguous. if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) { CXXBasePaths::paths_iterator FirstPath = Paths.begin(); DeclContext::lookup_iterator FirstD = FirstPath->Decls.begin(); DeclContext::lookup_iterator CurrentD = Path->Decls.begin(); while (FirstD != FirstPath->Decls.end() && CurrentD != Path->Decls.end()) { if ((*FirstD)->getUnderlyingDecl()->getCanonicalDecl() != (*CurrentD)->getUnderlyingDecl()->getCanonicalDecl()) break; ++FirstD; ++CurrentD; } if (FirstD == FirstPath->Decls.end() && CurrentD == Path->Decls.end()) continue; } R.setAmbiguousBaseSubobjectTypes(Paths); return true; } if (SubobjectNumber != PathElement.SubobjectNumber) { // We have a different subobject of the same type. // C++ [class.member.lookup]p5: // A static member, a nested type or an enumerator defined in // a base class T can unambiguously be found even if an object // has more than one base class subobject of type T. if (HasOnlyStaticMembers(Path->Decls.begin(), Path->Decls.end())) continue; // We have found a nonstatic member name in multiple, distinct // subobjects. Name lookup is ambiguous. R.setAmbiguousBaseSubobjects(Paths); return true; } } // Lookup in a base class succeeded; return these results. for (auto *D : Paths.front().Decls) { AccessSpecifier AS = CXXRecordDecl::MergeAccess(SubobjectAccess, D->getAccess()); R.addDecl(D, AS); } R.resolveKind(); return true; } /// \brief Performs qualified name lookup or special type of lookup for /// "__super::" scope specifier. /// /// This routine is a convenience overload meant to be called from contexts /// that need to perform a qualified name lookup with an optional C++ scope /// specifier that might require special kind of lookup. /// /// \param R captures both the lookup criteria and any lookup results found. /// /// \param LookupCtx The context in which qualified name lookup will /// search. /// /// \param SS An optional C++ scope-specifier. /// /// \returns true if lookup succeeded, false if it failed. bool Sema::LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx, CXXScopeSpec &SS) { auto *NNS = SS.getScopeRep(); if (NNS && NNS->getKind() == NestedNameSpecifier::Super) return LookupInSuper(R, NNS->getAsRecordDecl()); else return LookupQualifiedName(R, LookupCtx); } /// @brief Performs name lookup for a name that was parsed in the /// source code, and may contain a C++ scope specifier. /// /// This routine is a convenience routine meant to be called from /// contexts that receive a name and an optional C++ scope specifier /// (e.g., "N::M::x"). It will then perform either qualified or /// unqualified name lookup (with LookupQualifiedName or LookupName, /// respectively) on the given name and return those results. It will /// perform a special type of lookup for "__super::" scope specifier. /// /// @param S The scope from which unqualified name lookup will /// begin. /// /// @param SS An optional C++ scope-specifier, e.g., "::N::M". /// /// @param EnteringContext Indicates whether we are going to enter the /// context of the scope-specifier SS (if present). /// /// @returns True if any decls were found (but possibly ambiguous) bool Sema::LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS, bool AllowBuiltinCreation, bool EnteringContext) { if (SS && SS->isInvalid()) { // When the scope specifier is invalid, don't even look for // anything. return false; } if (SS && SS->isSet()) { NestedNameSpecifier *NNS = SS->getScopeRep(); if (NNS->getKind() == NestedNameSpecifier::Super) return LookupInSuper(R, NNS->getAsRecordDecl()); if (DeclContext *DC = computeDeclContext(*SS, EnteringContext)) { // We have resolved the scope specifier to a particular declaration // contex, and will perform name lookup in that context. if (!DC->isDependentContext() && RequireCompleteDeclContext(*SS, DC)) return false; R.setContextRange(SS->getRange()); return LookupQualifiedName(R, DC); } // We could not resolve the scope specified to a specific declaration // context, which means that SS refers to an unknown specialization. // Name lookup can't find anything in this case. R.setNotFoundInCurrentInstantiation(); R.setContextRange(SS->getRange()); return false; } // Perform unqualified name lookup starting in the given scope. return LookupName(R, S, AllowBuiltinCreation); } /// \brief Perform qualified name lookup into all base classes of the given /// class. /// /// \param R captures both the lookup criteria and any lookup results found. /// /// \param Class The context in which qualified name lookup will /// search. Name lookup will search in all base classes merging the results. /// /// @returns True if any decls were found (but possibly ambiguous) bool Sema::LookupInSuper(LookupResult &R, CXXRecordDecl *Class) { // The access-control rules we use here are essentially the rules for // doing a lookup in Class that just magically skipped the direct // members of Class itself. That is, the naming class is Class, and the // access includes the access of the base. for (const auto &BaseSpec : Class->bases()) { CXXRecordDecl *RD = cast( BaseSpec.getType()->castAs()->getDecl()); LookupResult Result(*this, R.getLookupNameInfo(), R.getLookupKind()); Result.setBaseObjectType(Context.getRecordType(Class)); LookupQualifiedName(Result, RD); // Copy the lookup results into the target, merging the base's access into // the path access. for (auto I = Result.begin(), E = Result.end(); I != E; ++I) { R.addDecl(I.getDecl(), CXXRecordDecl::MergeAccess(BaseSpec.getAccessSpecifier(), I.getAccess())); } Result.suppressDiagnostics(); } R.resolveKind(); R.setNamingClass(Class); return !R.empty(); } /// \brief Produce a diagnostic describing the ambiguity that resulted /// from name lookup. /// /// \param Result The result of the ambiguous lookup to be diagnosed. void Sema::DiagnoseAmbiguousLookup(LookupResult &Result) { assert(Result.isAmbiguous() && "Lookup result must be ambiguous"); DeclarationName Name = Result.getLookupName(); SourceLocation NameLoc = Result.getNameLoc(); SourceRange LookupRange = Result.getContextRange(); switch (Result.getAmbiguityKind()) { case LookupResult::AmbiguousBaseSubobjects: { CXXBasePaths *Paths = Result.getBasePaths(); QualType SubobjectType = Paths->front().back().Base->getType(); Diag(NameLoc, diag::err_ambiguous_member_multiple_subobjects) << Name << SubobjectType << getAmbiguousPathsDisplayString(*Paths) << LookupRange; DeclContext::lookup_iterator Found = Paths->front().Decls.begin(); while (isa(*Found) && cast(*Found)->isStatic()) ++Found; Diag((*Found)->getLocation(), diag::note_ambiguous_member_found); break; } case LookupResult::AmbiguousBaseSubobjectTypes: { Diag(NameLoc, diag::err_ambiguous_member_multiple_subobject_types) << Name << LookupRange; CXXBasePaths *Paths = Result.getBasePaths(); std::set DeclsPrinted; for (CXXBasePaths::paths_iterator Path = Paths->begin(), PathEnd = Paths->end(); Path != PathEnd; ++Path) { Decl *D = Path->Decls.front(); if (DeclsPrinted.insert(D).second) Diag(D->getLocation(), diag::note_ambiguous_member_found); } break; } case LookupResult::AmbiguousTagHiding: { Diag(NameLoc, diag::err_ambiguous_tag_hiding) << Name << LookupRange; llvm::SmallPtrSet TagDecls; for (auto *D : Result) if (TagDecl *TD = dyn_cast(D)) { TagDecls.insert(TD); Diag(TD->getLocation(), diag::note_hidden_tag); } for (auto *D : Result) if (!isa(D)) Diag(D->getLocation(), diag::note_hiding_object); // For recovery purposes, go ahead and implement the hiding. LookupResult::Filter F = Result.makeFilter(); while (F.hasNext()) { if (TagDecls.count(F.next())) F.erase(); } F.done(); break; } case LookupResult::AmbiguousReference: { Diag(NameLoc, diag::err_ambiguous_reference) << Name << LookupRange; for (auto *D : Result) Diag(D->getLocation(), diag::note_ambiguous_candidate) << D; break; } } } namespace { struct AssociatedLookup { AssociatedLookup(Sema &S, SourceLocation InstantiationLoc, Sema::AssociatedNamespaceSet &Namespaces, Sema::AssociatedClassSet &Classes) : S(S), Namespaces(Namespaces), Classes(Classes), InstantiationLoc(InstantiationLoc) { } Sema &S; Sema::AssociatedNamespaceSet &Namespaces; Sema::AssociatedClassSet &Classes; SourceLocation InstantiationLoc; }; } // end anonymous namespace static void addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType T); static void CollectEnclosingNamespace(Sema::AssociatedNamespaceSet &Namespaces, DeclContext *Ctx) { // Add the associated namespace for this class. // We don't use DeclContext::getEnclosingNamespaceContext() as this may // be a locally scoped record. // We skip out of inline namespaces. The innermost non-inline namespace // contains all names of all its nested inline namespaces anyway, so we can // replace the entire inline namespace tree with its root. while (Ctx->isRecord() || Ctx->isTransparentContext() || Ctx->isInlineNamespace()) Ctx = Ctx->getParent(); if (Ctx->isFileContext()) Namespaces.insert(Ctx->getPrimaryContext()); } // \brief Add the associated classes and namespaces for argument-dependent // lookup that involves a template argument (C++ [basic.lookup.koenig]p2). static void addAssociatedClassesAndNamespaces(AssociatedLookup &Result, const TemplateArgument &Arg) { // C++ [basic.lookup.koenig]p2, last bullet: // -- [...] ; switch (Arg.getKind()) { case TemplateArgument::Null: break; case TemplateArgument::Type: // [...] the namespaces and classes associated with the types of the // template arguments provided for template type parameters (excluding // template template parameters) addAssociatedClassesAndNamespaces(Result, Arg.getAsType()); break; case TemplateArgument::Template: case TemplateArgument::TemplateExpansion: { // [...] the namespaces in which any template template arguments are // defined; and the classes in which any member templates used as // template template arguments are defined. TemplateName Template = Arg.getAsTemplateOrTemplatePattern(); if (ClassTemplateDecl *ClassTemplate = dyn_cast(Template.getAsTemplateDecl())) { DeclContext *Ctx = ClassTemplate->getDeclContext(); if (CXXRecordDecl *EnclosingClass = dyn_cast(Ctx)) Result.Classes.insert(EnclosingClass); // Add the associated namespace for this class. CollectEnclosingNamespace(Result.Namespaces, Ctx); } break; } case TemplateArgument::Declaration: case TemplateArgument::Integral: case TemplateArgument::Expression: case TemplateArgument::NullPtr: // [Note: non-type template arguments do not contribute to the set of // associated namespaces. ] break; case TemplateArgument::Pack: for (const auto &P : Arg.pack_elements()) addAssociatedClassesAndNamespaces(Result, P); break; } } // \brief Add the associated classes and namespaces for // argument-dependent lookup with an argument of class type // (C++ [basic.lookup.koenig]p2). static void addAssociatedClassesAndNamespaces(AssociatedLookup &Result, CXXRecordDecl *Class) { // Just silently ignore anything whose name is __va_list_tag. if (Class->getDeclName() == Result.S.VAListTagName) return; // C++ [basic.lookup.koenig]p2: // [...] // -- If T is a class type (including unions), its associated // classes are: the class itself; the class of which it is a // member, if any; and its direct and indirect base // classes. Its associated namespaces are the namespaces in // which its associated classes are defined. // Add the class of which it is a member, if any. DeclContext *Ctx = Class->getDeclContext(); if (CXXRecordDecl *EnclosingClass = dyn_cast(Ctx)) Result.Classes.insert(EnclosingClass); // Add the associated namespace for this class. CollectEnclosingNamespace(Result.Namespaces, Ctx); // Add the class itself. If we've already seen this class, we don't // need to visit base classes. // // FIXME: That's not correct, we may have added this class only because it // was the enclosing class of another class, and in that case we won't have // added its base classes yet. if (!Result.Classes.insert(Class)) return; // -- If T is a template-id, its associated namespaces and classes are // the namespace in which the template is defined; for member // templates, the member template's class; the namespaces and classes // associated with the types of the template arguments provided for // template type parameters (excluding template template parameters); the // namespaces in which any template template arguments are defined; and // the classes in which any member templates used as template template // arguments are defined. [Note: non-type template arguments do not // contribute to the set of associated namespaces. ] if (ClassTemplateSpecializationDecl *Spec = dyn_cast(Class)) { DeclContext *Ctx = Spec->getSpecializedTemplate()->getDeclContext(); if (CXXRecordDecl *EnclosingClass = dyn_cast(Ctx)) Result.Classes.insert(EnclosingClass); // Add the associated namespace for this class. CollectEnclosingNamespace(Result.Namespaces, Ctx); const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs(); for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) addAssociatedClassesAndNamespaces(Result, TemplateArgs[I]); } // Only recurse into base classes for complete types. if (!Result.S.isCompleteType(Result.InstantiationLoc, Result.S.Context.getRecordType(Class))) return; // Add direct and indirect base classes along with their associated // namespaces. SmallVector Bases; Bases.push_back(Class); while (!Bases.empty()) { // Pop this class off the stack. Class = Bases.pop_back_val(); // Visit the base classes. for (const auto &Base : Class->bases()) { const RecordType *BaseType = Base.getType()->getAs(); // In dependent contexts, we do ADL twice, and the first time around, // the base type might be a dependent TemplateSpecializationType, or a // TemplateTypeParmType. If that happens, simply ignore it. // FIXME: If we want to support export, we probably need to add the // namespace of the template in a TemplateSpecializationType, or even // the classes and namespaces of known non-dependent arguments. if (!BaseType) continue; CXXRecordDecl *BaseDecl = cast(BaseType->getDecl()); if (Result.Classes.insert(BaseDecl)) { // Find the associated namespace for this base class. DeclContext *BaseCtx = BaseDecl->getDeclContext(); CollectEnclosingNamespace(Result.Namespaces, BaseCtx); // Make sure we visit the bases of this base class. if (BaseDecl->bases_begin() != BaseDecl->bases_end()) Bases.push_back(BaseDecl); } } } } // \brief Add the associated classes and namespaces for // argument-dependent lookup with an argument of type T // (C++ [basic.lookup.koenig]p2). static void addAssociatedClassesAndNamespaces(AssociatedLookup &Result, QualType Ty) { // C++ [basic.lookup.koenig]p2: // // For each argument type T in the function call, there is a set // of zero or more associated namespaces and a set of zero or more // associated classes to be considered. The sets of namespaces and // classes is determined entirely by the types of the function // arguments (and the namespace of any template template // argument). Typedef names and using-declarations used to specify // the types do not contribute to this set. The sets of namespaces // and classes are determined in the following way: SmallVector Queue; const Type *T = Ty->getCanonicalTypeInternal().getTypePtr(); while (true) { switch (T->getTypeClass()) { #define TYPE(Class, Base) #define DEPENDENT_TYPE(Class, Base) case Type::Class: #define NON_CANONICAL_TYPE(Class, Base) case Type::Class: #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class: #define ABSTRACT_TYPE(Class, Base) #include "clang/AST/TypeNodes.def" // T is canonical. We can also ignore dependent types because // we don't need to do ADL at the definition point, but if we // wanted to implement template export (or if we find some other // use for associated classes and namespaces...) this would be // wrong. break; // -- If T is a pointer to U or an array of U, its associated // namespaces and classes are those associated with U. case Type::Pointer: T = cast(T)->getPointeeType().getTypePtr(); continue; case Type::ConstantArray: case Type::IncompleteArray: case Type::VariableArray: T = cast(T)->getElementType().getTypePtr(); continue; // -- If T is a fundamental type, its associated sets of // namespaces and classes are both empty. case Type::Builtin: break; // -- If T is a class type (including unions), its associated // classes are: the class itself; the class of which it is a // member, if any; and its direct and indirect base // classes. Its associated namespaces are the namespaces in // which its associated classes are defined. case Type::Record: { CXXRecordDecl *Class = cast(cast(T)->getDecl()); addAssociatedClassesAndNamespaces(Result, Class); break; } // -- If T is an enumeration type, its associated namespace is // the namespace in which it is defined. If it is class // member, its associated class is the member's class; else // it has no associated class. case Type::Enum: { EnumDecl *Enum = cast(T)->getDecl(); DeclContext *Ctx = Enum->getDeclContext(); if (CXXRecordDecl *EnclosingClass = dyn_cast(Ctx)) Result.Classes.insert(EnclosingClass); // Add the associated namespace for this class. CollectEnclosingNamespace(Result.Namespaces, Ctx); break; } // -- If T is a function type, its associated namespaces and // classes are those associated with the function parameter // types and those associated with the return type. case Type::FunctionProto: { const FunctionProtoType *Proto = cast(T); for (const auto &Arg : Proto->param_types()) Queue.push_back(Arg.getTypePtr()); // fallthrough } case Type::FunctionNoProto: { const FunctionType *FnType = cast(T); T = FnType->getReturnType().getTypePtr(); continue; } // -- If T is a pointer to a member function of a class X, its // associated namespaces and classes are those associated // with the function parameter types and return type, // together with those associated with X. // // -- If T is a pointer to a data member of class X, its // associated namespaces and classes are those associated // with the member type together with those associated with // X. case Type::MemberPointer: { const MemberPointerType *MemberPtr = cast(T); // Queue up the class type into which this points. Queue.push_back(MemberPtr->getClass()); // And directly continue with the pointee type. T = MemberPtr->getPointeeType().getTypePtr(); continue; } // As an extension, treat this like a normal pointer. case Type::BlockPointer: T = cast(T)->getPointeeType().getTypePtr(); continue; // References aren't covered by the standard, but that's such an // obvious defect that we cover them anyway. case Type::LValueReference: case Type::RValueReference: T = cast(T)->getPointeeType().getTypePtr(); continue; // These are fundamental types. case Type::Vector: case Type::ExtVector: case Type::Complex: break; // Non-deduced auto types only get here for error cases. case Type::Auto: break; // If T is an Objective-C object or interface type, or a pointer to an // object or interface type, the associated namespace is the global // namespace. case Type::ObjCObject: case Type::ObjCInterface: case Type::ObjCObjectPointer: Result.Namespaces.insert(Result.S.Context.getTranslationUnitDecl()); break; // Atomic types are just wrappers; use the associations of the // contained type. case Type::Atomic: T = cast(T)->getValueType().getTypePtr(); continue; case Type::Pipe: T = cast(T)->getElementType().getTypePtr(); continue; } if (Queue.empty()) break; T = Queue.pop_back_val(); } } /// \brief Find the associated classes and namespaces for /// argument-dependent lookup for a call with the given set of /// arguments. /// /// This routine computes the sets of associated classes and associated /// namespaces searched by argument-dependent lookup /// (C++ [basic.lookup.argdep]) for a given set of arguments. void Sema::FindAssociatedClassesAndNamespaces( SourceLocation InstantiationLoc, ArrayRef Args, AssociatedNamespaceSet &AssociatedNamespaces, AssociatedClassSet &AssociatedClasses) { AssociatedNamespaces.clear(); AssociatedClasses.clear(); AssociatedLookup Result(*this, InstantiationLoc, AssociatedNamespaces, AssociatedClasses); // C++ [basic.lookup.koenig]p2: // For each argument type T in the function call, there is a set // of zero or more associated namespaces and a set of zero or more // associated classes to be considered. The sets of namespaces and // classes is determined entirely by the types of the function // arguments (and the namespace of any template template // argument). for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) { Expr *Arg = Args[ArgIdx]; if (Arg->getType() != Context.OverloadTy) { addAssociatedClassesAndNamespaces(Result, Arg->getType()); continue; } // [...] In addition, if the argument is the name or address of a // set of overloaded functions and/or function templates, its // associated classes and namespaces are the union of those // associated with each of the members of the set: the namespace // in which the function or function template is defined and the // classes and namespaces associated with its (non-dependent) // parameter types and return type. Arg = Arg->IgnoreParens(); if (UnaryOperator *unaryOp = dyn_cast(Arg)) if (unaryOp->getOpcode() == UO_AddrOf) Arg = unaryOp->getSubExpr(); UnresolvedLookupExpr *ULE = dyn_cast(Arg); if (!ULE) continue; for (const auto *D : ULE->decls()) { // Look through any using declarations to find the underlying function. const FunctionDecl *FDecl = D->getUnderlyingDecl()->getAsFunction(); // Add the classes and namespaces associated with the parameter // types and return type of this function. addAssociatedClassesAndNamespaces(Result, FDecl->getType()); } } } NamedDecl *Sema::LookupSingleName(Scope *S, DeclarationName Name, SourceLocation Loc, LookupNameKind NameKind, RedeclarationKind Redecl) { LookupResult R(*this, Name, Loc, NameKind, Redecl); LookupName(R, S); return R.getAsSingle(); } /// \brief Find the protocol with the given name, if any. ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II, SourceLocation IdLoc, RedeclarationKind Redecl) { Decl *D = LookupSingleName(TUScope, II, IdLoc, LookupObjCProtocolName, Redecl); return cast_or_null(D); } void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S, QualType T1, QualType T2, UnresolvedSetImpl &Functions) { // C++ [over.match.oper]p3: // -- The set of non-member candidates is the result of the // unqualified lookup of operator@ in the context of the // expression according to the usual rules for name lookup in // unqualified function calls (3.4.2) except that all member // functions are ignored. DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); LookupResult Operators(*this, OpName, SourceLocation(), LookupOperatorName); LookupName(Operators, S); assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"); Functions.append(Operators.begin(), Operators.end()); } Sema::SpecialMemberOverloadResult *Sema::LookupSpecialMember(CXXRecordDecl *RD, CXXSpecialMember SM, bool ConstArg, bool VolatileArg, bool RValueThis, bool ConstThis, bool VolatileThis) { assert(CanDeclareSpecialMemberFunction(RD) && "doing special member lookup into record that isn't fully complete"); RD = RD->getDefinition(); if (RValueThis || ConstThis || VolatileThis) assert((SM == CXXCopyAssignment || SM == CXXMoveAssignment) && "constructors and destructors always have unqualified lvalue this"); if (ConstArg || VolatileArg) assert((SM != CXXDefaultConstructor && SM != CXXDestructor) && "parameter-less special members can't have qualified arguments"); llvm::FoldingSetNodeID ID; ID.AddPointer(RD); ID.AddInteger(SM); ID.AddInteger(ConstArg); ID.AddInteger(VolatileArg); ID.AddInteger(RValueThis); ID.AddInteger(ConstThis); ID.AddInteger(VolatileThis); void *InsertPoint; SpecialMemberOverloadResult *Result = SpecialMemberCache.FindNodeOrInsertPos(ID, InsertPoint); // This was already cached if (Result) return Result; Result = BumpAlloc.Allocate(); Result = new (Result) SpecialMemberOverloadResult(ID); SpecialMemberCache.InsertNode(Result, InsertPoint); if (SM == CXXDestructor) { if (RD->needsImplicitDestructor()) DeclareImplicitDestructor(RD); CXXDestructorDecl *DD = RD->getDestructor(); assert(DD && "record without a destructor"); Result->setMethod(DD); Result->setKind(DD->isDeleted() ? SpecialMemberOverloadResult::NoMemberOrDeleted : SpecialMemberOverloadResult::Success); return Result; } // Prepare for overload resolution. Here we construct a synthetic argument // if necessary and make sure that implicit functions are declared. CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD)); DeclarationName Name; Expr *Arg = nullptr; unsigned NumArgs; QualType ArgType = CanTy; ExprValueKind VK = VK_LValue; if (SM == CXXDefaultConstructor) { Name = Context.DeclarationNames.getCXXConstructorName(CanTy); NumArgs = 0; if (RD->needsImplicitDefaultConstructor()) DeclareImplicitDefaultConstructor(RD); } else { if (SM == CXXCopyConstructor || SM == CXXMoveConstructor) { Name = Context.DeclarationNames.getCXXConstructorName(CanTy); if (RD->needsImplicitCopyConstructor()) DeclareImplicitCopyConstructor(RD); if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveConstructor()) DeclareImplicitMoveConstructor(RD); } else { Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); if (RD->needsImplicitCopyAssignment()) DeclareImplicitCopyAssignment(RD); if (getLangOpts().CPlusPlus11 && RD->needsImplicitMoveAssignment()) DeclareImplicitMoveAssignment(RD); } if (ConstArg) ArgType.addConst(); if (VolatileArg) ArgType.addVolatile(); // This isn't /really/ specified by the standard, but it's implied // we should be working from an RValue in the case of move to ensure // that we prefer to bind to rvalue references, and an LValue in the // case of copy to ensure we don't bind to rvalue references. // Possibly an XValue is actually correct in the case of move, but // there is no semantic difference for class types in this restricted // case. if (SM == CXXCopyConstructor || SM == CXXCopyAssignment) VK = VK_LValue; else VK = VK_RValue; } OpaqueValueExpr FakeArg(SourceLocation(), ArgType, VK); if (SM != CXXDefaultConstructor) { NumArgs = 1; Arg = &FakeArg; } // Create the object argument QualType ThisTy = CanTy; if (ConstThis) ThisTy.addConst(); if (VolatileThis) ThisTy.addVolatile(); Expr::Classification Classification = OpaqueValueExpr(SourceLocation(), ThisTy, RValueThis ? VK_RValue : VK_LValue).Classify(Context); // Now we perform lookup on the name we computed earlier and do overload // resolution. Lookup is only performed directly into the class since there // will always be a (possibly implicit) declaration to shadow any others. OverloadCandidateSet OCS(RD->getLocation(), OverloadCandidateSet::CSK_Normal); DeclContext::lookup_result R = RD->lookup(Name); if (R.empty()) { // We might have no default constructor because we have a lambda's closure // type, rather than because there's some other declared constructor. // Every class has a copy/move constructor, copy/move assignment, and // destructor. assert(SM == CXXDefaultConstructor && "lookup for a constructor or assignment operator was empty"); Result->setMethod(nullptr); Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); return Result; } // Copy the candidates as our processing of them may load new declarations // from an external source and invalidate lookup_result. SmallVector Candidates(R.begin(), R.end()); for (NamedDecl *CandDecl : Candidates) { if (CandDecl->isInvalidDecl()) continue; DeclAccessPair Cand = DeclAccessPair::make(CandDecl, AS_public); auto CtorInfo = getConstructorInfo(Cand); if (CXXMethodDecl *M = dyn_cast(Cand->getUnderlyingDecl())) { if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) AddMethodCandidate(M, Cand, RD, ThisTy, Classification, llvm::makeArrayRef(&Arg, NumArgs), OCS, true); else if (CtorInfo) AddOverloadCandidate(CtorInfo.Constructor, CtorInfo.FoundDecl, llvm::makeArrayRef(&Arg, NumArgs), OCS, true); else AddOverloadCandidate(M, Cand, llvm::makeArrayRef(&Arg, NumArgs), OCS, true); } else if (FunctionTemplateDecl *Tmpl = dyn_cast(Cand->getUnderlyingDecl())) { if (SM == CXXCopyAssignment || SM == CXXMoveAssignment) AddMethodTemplateCandidate( Tmpl, Cand, RD, nullptr, ThisTy, Classification, llvm::makeArrayRef(&Arg, NumArgs), OCS, true); else if (CtorInfo) AddTemplateOverloadCandidate( CtorInfo.ConstructorTmpl, CtorInfo.FoundDecl, nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true); else AddTemplateOverloadCandidate( Tmpl, Cand, nullptr, llvm::makeArrayRef(&Arg, NumArgs), OCS, true); } else { assert(isa(Cand.getDecl()) && "illegal Kind of operator = Decl"); } } OverloadCandidateSet::iterator Best; switch (OCS.BestViableFunction(*this, SourceLocation(), Best)) { case OR_Success: Result->setMethod(cast(Best->Function)); Result->setKind(SpecialMemberOverloadResult::Success); break; case OR_Deleted: Result->setMethod(cast(Best->Function)); Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); break; case OR_Ambiguous: Result->setMethod(nullptr); Result->setKind(SpecialMemberOverloadResult::Ambiguous); break; case OR_No_Viable_Function: Result->setMethod(nullptr); Result->setKind(SpecialMemberOverloadResult::NoMemberOrDeleted); break; } return Result; } /// \brief Look up the default constructor for the given class. CXXConstructorDecl *Sema::LookupDefaultConstructor(CXXRecordDecl *Class) { SpecialMemberOverloadResult *Result = LookupSpecialMember(Class, CXXDefaultConstructor, false, false, false, false, false); return cast_or_null(Result->getMethod()); } /// \brief Look up the copying constructor for the given class. CXXConstructorDecl *Sema::LookupCopyingConstructor(CXXRecordDecl *Class, unsigned Quals) { assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && "non-const, non-volatile qualifiers for copy ctor arg"); SpecialMemberOverloadResult *Result = LookupSpecialMember(Class, CXXCopyConstructor, Quals & Qualifiers::Const, Quals & Qualifiers::Volatile, false, false, false); return cast_or_null(Result->getMethod()); } /// \brief Look up the moving constructor for the given class. CXXConstructorDecl *Sema::LookupMovingConstructor(CXXRecordDecl *Class, unsigned Quals) { SpecialMemberOverloadResult *Result = LookupSpecialMember(Class, CXXMoveConstructor, Quals & Qualifiers::Const, Quals & Qualifiers::Volatile, false, false, false); return cast_or_null(Result->getMethod()); } /// \brief Look up the constructors for the given class. DeclContext::lookup_result Sema::LookupConstructors(CXXRecordDecl *Class) { // If the implicit constructors have not yet been declared, do so now. if (CanDeclareSpecialMemberFunction(Class)) { if (Class->needsImplicitDefaultConstructor()) DeclareImplicitDefaultConstructor(Class); if (Class->needsImplicitCopyConstructor()) DeclareImplicitCopyConstructor(Class); if (getLangOpts().CPlusPlus11 && Class->needsImplicitMoveConstructor()) DeclareImplicitMoveConstructor(Class); } CanQualType T = Context.getCanonicalType(Context.getTypeDeclType(Class)); DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(T); return Class->lookup(Name); } /// \brief Look up the copying assignment operator for the given class. CXXMethodDecl *Sema::LookupCopyingAssignment(CXXRecordDecl *Class, unsigned Quals, bool RValueThis, unsigned ThisQuals) { assert(!(Quals & ~(Qualifiers::Const | Qualifiers::Volatile)) && "non-const, non-volatile qualifiers for copy assignment arg"); assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && "non-const, non-volatile qualifiers for copy assignment this"); SpecialMemberOverloadResult *Result = LookupSpecialMember(Class, CXXCopyAssignment, Quals & Qualifiers::Const, Quals & Qualifiers::Volatile, RValueThis, ThisQuals & Qualifiers::Const, ThisQuals & Qualifiers::Volatile); return Result->getMethod(); } /// \brief Look up the moving assignment operator for the given class. CXXMethodDecl *Sema::LookupMovingAssignment(CXXRecordDecl *Class, unsigned Quals, bool RValueThis, unsigned ThisQuals) { assert(!(ThisQuals & ~(Qualifiers::Const | Qualifiers::Volatile)) && "non-const, non-volatile qualifiers for copy assignment this"); SpecialMemberOverloadResult *Result = LookupSpecialMember(Class, CXXMoveAssignment, Quals & Qualifiers::Const, Quals & Qualifiers::Volatile, RValueThis, ThisQuals & Qualifiers::Const, ThisQuals & Qualifiers::Volatile); return Result->getMethod(); } /// \brief Look for the destructor of the given class. /// /// During semantic analysis, this routine should be used in lieu of /// CXXRecordDecl::getDestructor(). /// /// \returns The destructor for this class. CXXDestructorDecl *Sema::LookupDestructor(CXXRecordDecl *Class) { return cast(LookupSpecialMember(Class, CXXDestructor, false, false, false, false, false)->getMethod()); } /// LookupLiteralOperator - Determine which literal operator should be used for /// a user-defined literal, per C++11 [lex.ext]. /// /// Normal overload resolution is not used to select which literal operator to /// call for a user-defined literal. Look up the provided literal operator name, /// and filter the results to the appropriate set for the given argument types. Sema::LiteralOperatorLookupResult Sema::LookupLiteralOperator(Scope *S, LookupResult &R, ArrayRef ArgTys, bool AllowRaw, bool AllowTemplate, bool AllowStringTemplate) { LookupName(R, S); assert(R.getResultKind() != LookupResult::Ambiguous && "literal operator lookup can't be ambiguous"); // Filter the lookup results appropriately. LookupResult::Filter F = R.makeFilter(); bool FoundRaw = false; bool FoundTemplate = false; bool FoundStringTemplate = false; bool FoundExactMatch = false; while (F.hasNext()) { Decl *D = F.next(); if (UsingShadowDecl *USD = dyn_cast(D)) D = USD->getTargetDecl(); // If the declaration we found is invalid, skip it. if (D->isInvalidDecl()) { F.erase(); continue; } bool IsRaw = false; bool IsTemplate = false; bool IsStringTemplate = false; bool IsExactMatch = false; if (FunctionDecl *FD = dyn_cast(D)) { if (FD->getNumParams() == 1 && FD->getParamDecl(0)->getType()->getAs()) IsRaw = true; else if (FD->getNumParams() == ArgTys.size()) { IsExactMatch = true; for (unsigned ArgIdx = 0; ArgIdx != ArgTys.size(); ++ArgIdx) { QualType ParamTy = FD->getParamDecl(ArgIdx)->getType(); if (!Context.hasSameUnqualifiedType(ArgTys[ArgIdx], ParamTy)) { IsExactMatch = false; break; } } } } if (FunctionTemplateDecl *FD = dyn_cast(D)) { TemplateParameterList *Params = FD->getTemplateParameters(); if (Params->size() == 1) IsTemplate = true; else IsStringTemplate = true; } if (IsExactMatch) { FoundExactMatch = true; AllowRaw = false; AllowTemplate = false; AllowStringTemplate = false; if (FoundRaw || FoundTemplate || FoundStringTemplate) { // Go through again and remove the raw and template decls we've // already found. F.restart(); FoundRaw = FoundTemplate = FoundStringTemplate = false; } } else if (AllowRaw && IsRaw) { FoundRaw = true; } else if (AllowTemplate && IsTemplate) { FoundTemplate = true; } else if (AllowStringTemplate && IsStringTemplate) { FoundStringTemplate = true; } else { F.erase(); } } F.done(); // C++11 [lex.ext]p3, p4: If S contains a literal operator with a matching // parameter type, that is used in preference to a raw literal operator // or literal operator template. if (FoundExactMatch) return LOLR_Cooked; // C++11 [lex.ext]p3, p4: S shall contain a raw literal operator or a literal // operator template, but not both. if (FoundRaw && FoundTemplate) { Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName(); for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) NoteOverloadCandidate(*I, (*I)->getUnderlyingDecl()->getAsFunction()); return LOLR_Error; } if (FoundRaw) return LOLR_Raw; if (FoundTemplate) return LOLR_Template; if (FoundStringTemplate) return LOLR_StringTemplate; // Didn't find anything we could use. Diag(R.getNameLoc(), diag::err_ovl_no_viable_literal_operator) << R.getLookupName() << (int)ArgTys.size() << ArgTys[0] << (ArgTys.size() == 2 ? ArgTys[1] : QualType()) << AllowRaw << (AllowTemplate || AllowStringTemplate); return LOLR_Error; } void ADLResult::insert(NamedDecl *New) { NamedDecl *&Old = Decls[cast(New->getCanonicalDecl())]; // If we haven't yet seen a decl for this key, or the last decl // was exactly this one, we're done. if (Old == nullptr || Old == New) { Old = New; return; } // Otherwise, decide which is a more recent redeclaration. FunctionDecl *OldFD = Old->getAsFunction(); FunctionDecl *NewFD = New->getAsFunction(); FunctionDecl *Cursor = NewFD; while (true) { Cursor = Cursor->getPreviousDecl(); // If we got to the end without finding OldFD, OldFD is the newer // declaration; leave things as they are. if (!Cursor) return; // If we do find OldFD, then NewFD is newer. if (Cursor == OldFD) break; // Otherwise, keep looking. } Old = New; } void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc, ArrayRef Args, ADLResult &Result) { // Find all of the associated namespaces and classes based on the // arguments we have. AssociatedNamespaceSet AssociatedNamespaces; AssociatedClassSet AssociatedClasses; FindAssociatedClassesAndNamespaces(Loc, Args, AssociatedNamespaces, AssociatedClasses); // C++ [basic.lookup.argdep]p3: // Let X be the lookup set produced by unqualified lookup (3.4.1) // and let Y be the lookup set produced by argument dependent // lookup (defined as follows). If X contains [...] then Y is // empty. Otherwise Y is the set of declarations found in the // namespaces associated with the argument types as described // below. The set of declarations found by the lookup of the name // is the union of X and Y. // // Here, we compute Y and add its members to the overloaded // candidate set. for (auto *NS : AssociatedNamespaces) { // When considering an associated namespace, the lookup is the // same as the lookup performed when the associated namespace is // used as a qualifier (3.4.3.2) except that: // // -- Any using-directives in the associated namespace are // ignored. // // -- Any namespace-scope friend functions declared in // associated classes are visible within their respective // namespaces even if they are not visible during an ordinary // lookup (11.4). DeclContext::lookup_result R = NS->lookup(Name); for (auto *D : R) { // If the only declaration here is an ordinary friend, consider // it only if it was declared in an associated classes. if ((D->getIdentifierNamespace() & Decl::IDNS_Ordinary) == 0) { // If it's neither ordinarily visible nor a friend, we can't find it. if ((D->getIdentifierNamespace() & Decl::IDNS_OrdinaryFriend) == 0) continue; bool DeclaredInAssociatedClass = false; for (Decl *DI = D; DI; DI = DI->getPreviousDecl()) { DeclContext *LexDC = DI->getLexicalDeclContext(); if (isa(LexDC) && AssociatedClasses.count(cast(LexDC)) && isVisible(cast(DI))) { DeclaredInAssociatedClass = true; break; } } if (!DeclaredInAssociatedClass) continue; } if (isa(D)) D = cast(D)->getTargetDecl(); if (!isa(D) && !isa(D)) continue; if (!isVisible(D) && !(D = findAcceptableDecl(*this, D))) continue; Result.insert(D); } } } //---------------------------------------------------------------------------- // Search for all visible declarations. //---------------------------------------------------------------------------- VisibleDeclConsumer::~VisibleDeclConsumer() { } bool VisibleDeclConsumer::includeHiddenDecls() const { return false; } namespace { class ShadowContextRAII; class VisibleDeclsRecord { public: /// \brief An entry in the shadow map, which is optimized to store a /// single declaration (the common case) but can also store a list /// of declarations. typedef llvm::TinyPtrVector ShadowMapEntry; private: /// \brief A mapping from declaration names to the declarations that have /// this name within a particular scope. typedef llvm::DenseMap ShadowMap; /// \brief A list of shadow maps, which is used to model name hiding. std::list ShadowMaps; /// \brief The declaration contexts we have already visited. llvm::SmallPtrSet VisitedContexts; friend class ShadowContextRAII; public: /// \brief Determine whether we have already visited this context /// (and, if not, note that we are going to visit that context now). bool visitedContext(DeclContext *Ctx) { return !VisitedContexts.insert(Ctx).second; } bool alreadyVisitedContext(DeclContext *Ctx) { return VisitedContexts.count(Ctx); } /// \brief Determine whether the given declaration is hidden in the /// current scope. /// /// \returns the declaration that hides the given declaration, or /// NULL if no such declaration exists. NamedDecl *checkHidden(NamedDecl *ND); /// \brief Add a declaration to the current shadow map. void add(NamedDecl *ND) { ShadowMaps.back()[ND->getDeclName()].push_back(ND); } }; /// \brief RAII object that records when we've entered a shadow context. class ShadowContextRAII { VisibleDeclsRecord &Visible; typedef VisibleDeclsRecord::ShadowMap ShadowMap; public: ShadowContextRAII(VisibleDeclsRecord &Visible) : Visible(Visible) { Visible.ShadowMaps.emplace_back(); } ~ShadowContextRAII() { Visible.ShadowMaps.pop_back(); } }; } // end anonymous namespace NamedDecl *VisibleDeclsRecord::checkHidden(NamedDecl *ND) { unsigned IDNS = ND->getIdentifierNamespace(); std::list::reverse_iterator SM = ShadowMaps.rbegin(); for (std::list::reverse_iterator SMEnd = ShadowMaps.rend(); SM != SMEnd; ++SM) { ShadowMap::iterator Pos = SM->find(ND->getDeclName()); if (Pos == SM->end()) continue; for (auto *D : Pos->second) { // A tag declaration does not hide a non-tag declaration. if (D->hasTagIdentifierNamespace() && (IDNS & (Decl::IDNS_Member | Decl::IDNS_Ordinary | Decl::IDNS_ObjCProtocol))) continue; // Protocols are in distinct namespaces from everything else. if (((D->getIdentifierNamespace() & Decl::IDNS_ObjCProtocol) || (IDNS & Decl::IDNS_ObjCProtocol)) && D->getIdentifierNamespace() != IDNS) continue; // Functions and function templates in the same scope overload // rather than hide. FIXME: Look for hiding based on function // signatures! if (D->getUnderlyingDecl()->isFunctionOrFunctionTemplate() && ND->getUnderlyingDecl()->isFunctionOrFunctionTemplate() && SM == ShadowMaps.rbegin()) continue; // We've found a declaration that hides this one. return D; } } return nullptr; } static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result, bool QualifiedNameLookup, bool InBaseClass, VisibleDeclConsumer &Consumer, VisibleDeclsRecord &Visited) { if (!Ctx) return; // Make sure we don't visit the same context twice. if (Visited.visitedContext(Ctx->getPrimaryContext())) return; // Outside C++, lookup results for the TU live on identifiers. if (isa(Ctx) && !Result.getSema().getLangOpts().CPlusPlus) { auto &S = Result.getSema(); auto &Idents = S.Context.Idents; // Ensure all external identifiers are in the identifier table. if (IdentifierInfoLookup *External = Idents.getExternalIdentifierLookup()) { std::unique_ptr Iter(External->getIdentifiers()); for (StringRef Name = Iter->Next(); !Name.empty(); Name = Iter->Next()) Idents.get(Name); } // Walk all lookup results in the TU for each identifier. for (const auto &Ident : Idents) { for (auto I = S.IdResolver.begin(Ident.getValue()), E = S.IdResolver.end(); I != E; ++I) { if (S.IdResolver.isDeclInScope(*I, Ctx)) { if (NamedDecl *ND = Result.getAcceptableDecl(*I)) { Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); Visited.add(ND); } } } } return; } if (CXXRecordDecl *Class = dyn_cast(Ctx)) Result.getSema().ForceDeclarationOfImplicitMembers(Class); // Enumerate all of the results in this context. for (DeclContextLookupResult R : Ctx->lookups()) { for (auto *D : R) { if (auto *ND = Result.getAcceptableDecl(D)) { Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass); Visited.add(ND); } } } // Traverse using directives for qualified name lookup. if (QualifiedNameLookup) { ShadowContextRAII Shadow(Visited); for (auto I : Ctx->using_directives()) { LookupVisibleDecls(I->getNominatedNamespace(), Result, QualifiedNameLookup, InBaseClass, Consumer, Visited); } } // Traverse the contexts of inherited C++ classes. if (CXXRecordDecl *Record = dyn_cast(Ctx)) { if (!Record->hasDefinition()) return; for (const auto &B : Record->bases()) { QualType BaseType = B.getType(); // Don't look into dependent bases, because name lookup can't look // there anyway. if (BaseType->isDependentType()) continue; const RecordType *Record = BaseType->getAs(); if (!Record) continue; // FIXME: It would be nice to be able to determine whether referencing // a particular member would be ambiguous. For example, given // // struct A { int member; }; // struct B { int member; }; // struct C : A, B { }; // // void f(C *c) { c->### } // // accessing 'member' would result in an ambiguity. However, we // could be smart enough to qualify the member with the base // class, e.g., // // c->B::member // // or // // c->A::member // Find results in this base class (and its bases). ShadowContextRAII Shadow(Visited); LookupVisibleDecls(Record->getDecl(), Result, QualifiedNameLookup, true, Consumer, Visited); } } // Traverse the contexts of Objective-C classes. if (ObjCInterfaceDecl *IFace = dyn_cast(Ctx)) { // Traverse categories. for (auto *Cat : IFace->visible_categories()) { ShadowContextRAII Shadow(Visited); LookupVisibleDecls(Cat, Result, QualifiedNameLookup, false, Consumer, Visited); } // Traverse protocols. for (auto *I : IFace->all_referenced_protocols()) { ShadowContextRAII Shadow(Visited); LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer, Visited); } // Traverse the superclass. if (IFace->getSuperClass()) { ShadowContextRAII Shadow(Visited); LookupVisibleDecls(IFace->getSuperClass(), Result, QualifiedNameLookup, true, Consumer, Visited); } // If there is an implementation, traverse it. We do this to find // synthesized ivars. if (IFace->getImplementation()) { ShadowContextRAII Shadow(Visited); LookupVisibleDecls(IFace->getImplementation(), Result, QualifiedNameLookup, InBaseClass, Consumer, Visited); } } else if (ObjCProtocolDecl *Protocol = dyn_cast(Ctx)) { for (auto *I : Protocol->protocols()) { ShadowContextRAII Shadow(Visited); LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer, Visited); } } else if (ObjCCategoryDecl *Category = dyn_cast(Ctx)) { for (auto *I : Category->protocols()) { ShadowContextRAII Shadow(Visited); LookupVisibleDecls(I, Result, QualifiedNameLookup, false, Consumer, Visited); } // If there is an implementation, traverse it. if (Category->getImplementation()) { ShadowContextRAII Shadow(Visited); LookupVisibleDecls(Category->getImplementation(), Result, QualifiedNameLookup, true, Consumer, Visited); } } } static void LookupVisibleDecls(Scope *S, LookupResult &Result, UnqualUsingDirectiveSet &UDirs, VisibleDeclConsumer &Consumer, VisibleDeclsRecord &Visited) { if (!S) return; if (!S->getEntity() || (!S->getParent() && !Visited.alreadyVisitedContext(S->getEntity())) || (S->getEntity())->isFunctionOrMethod()) { FindLocalExternScope FindLocals(Result); // Walk through the declarations in this Scope. for (auto *D : S->decls()) { if (NamedDecl *ND = dyn_cast(D)) if ((ND = Result.getAcceptableDecl(ND))) { Consumer.FoundDecl(ND, Visited.checkHidden(ND), nullptr, false); Visited.add(ND); } } } // FIXME: C++ [temp.local]p8 DeclContext *Entity = nullptr; if (S->getEntity()) { // Look into this scope's declaration context, along with any of its // parent lookup contexts (e.g., enclosing classes), up to the point // where we hit the context stored in the next outer scope. Entity = S->getEntity(); DeclContext *OuterCtx = findOuterContext(S).first; // FIXME for (DeclContext *Ctx = Entity; Ctx && !Ctx->Equals(OuterCtx); Ctx = Ctx->getLookupParent()) { if (ObjCMethodDecl *Method = dyn_cast(Ctx)) { if (Method->isInstanceMethod()) { // For instance methods, look for ivars in the method's interface. LookupResult IvarResult(Result.getSema(), Result.getLookupName(), Result.getNameLoc(), Sema::LookupMemberName); if (ObjCInterfaceDecl *IFace = Method->getClassInterface()) { LookupVisibleDecls(IFace, IvarResult, /*QualifiedNameLookup=*/false, /*InBaseClass=*/false, Consumer, Visited); } } // We've already performed all of the name lookup that we need // to for Objective-C methods; the next context will be the // outer scope. break; } if (Ctx->isFunctionOrMethod()) continue; LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/false, /*InBaseClass=*/false, Consumer, Visited); } } else if (!S->getParent()) { // Look into the translation unit scope. We walk through the translation // unit's declaration context, because the Scope itself won't have all of // the declarations if we loaded a precompiled header. // FIXME: We would like the translation unit's Scope object to point to the // translation unit, so we don't need this special "if" branch. However, // doing so would force the normal C++ name-lookup code to look into the // translation unit decl when the IdentifierInfo chains would suffice. // Once we fix that problem (which is part of a more general "don't look // in DeclContexts unless we have to" optimization), we can eliminate this. Entity = Result.getSema().Context.getTranslationUnitDecl(); LookupVisibleDecls(Entity, Result, /*QualifiedNameLookup=*/false, /*InBaseClass=*/false, Consumer, Visited); } if (Entity) { // Lookup visible declarations in any namespaces found by using // directives. for (const UnqualUsingEntry &UUE : UDirs.getNamespacesFor(Entity)) LookupVisibleDecls(const_cast(UUE.getNominatedNamespace()), Result, /*QualifiedNameLookup=*/false, /*InBaseClass=*/false, Consumer, Visited); } // Lookup names in the parent scope. ShadowContextRAII Shadow(Visited); LookupVisibleDecls(S->getParent(), Result, UDirs, Consumer, Visited); } void Sema::LookupVisibleDecls(Scope *S, LookupNameKind Kind, VisibleDeclConsumer &Consumer, bool IncludeGlobalScope) { // Determine the set of using directives available during // unqualified name lookup. Scope *Initial = S; UnqualUsingDirectiveSet UDirs; if (getLangOpts().CPlusPlus) { // Find the first namespace or translation-unit scope. while (S && !isNamespaceOrTranslationUnitScope(S)) S = S->getParent(); UDirs.visitScopeChain(Initial, S); } UDirs.done(); // Look for visible declarations. LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); Result.setAllowHidden(Consumer.includeHiddenDecls()); VisibleDeclsRecord Visited; if (!IncludeGlobalScope) Visited.visitedContext(Context.getTranslationUnitDecl()); ShadowContextRAII Shadow(Visited); ::LookupVisibleDecls(Initial, Result, UDirs, Consumer, Visited); } void Sema::LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind, VisibleDeclConsumer &Consumer, bool IncludeGlobalScope) { LookupResult Result(*this, DeclarationName(), SourceLocation(), Kind); Result.setAllowHidden(Consumer.includeHiddenDecls()); VisibleDeclsRecord Visited; if (!IncludeGlobalScope) Visited.visitedContext(Context.getTranslationUnitDecl()); ShadowContextRAII Shadow(Visited); ::LookupVisibleDecls(Ctx, Result, /*QualifiedNameLookup=*/true, /*InBaseClass=*/false, Consumer, Visited); } /// LookupOrCreateLabel - Do a name lookup of a label with the specified name. /// If GnuLabelLoc is a valid source location, then this is a definition /// of an __label__ label name, otherwise it is a normal label definition /// or use. LabelDecl *Sema::LookupOrCreateLabel(IdentifierInfo *II, SourceLocation Loc, SourceLocation GnuLabelLoc) { // Do a lookup to see if we have a label with this name already. NamedDecl *Res = nullptr; if (GnuLabelLoc.isValid()) { // Local label definitions always shadow existing labels. Res = LabelDecl::Create(Context, CurContext, Loc, II, GnuLabelLoc); Scope *S = CurScope; PushOnScopeChains(Res, S, true); return cast(Res); } // Not a GNU local label. Res = LookupSingleName(CurScope, II, Loc, LookupLabel, NotForRedeclaration); // If we found a label, check to see if it is in the same context as us. // When in a Block, we don't want to reuse a label in an enclosing function. if (Res && Res->getDeclContext() != CurContext) Res = nullptr; if (!Res) { // If not forward referenced or defined already, create the backing decl. Res = LabelDecl::Create(Context, CurContext, Loc, II); Scope *S = CurScope->getFnParent(); assert(S && "Not in a function?"); PushOnScopeChains(Res, S, true); } return cast(Res); } //===----------------------------------------------------------------------===// // Typo correction //===----------------------------------------------------------------------===// static bool isCandidateViable(CorrectionCandidateCallback &CCC, TypoCorrection &Candidate) { Candidate.setCallbackDistance(CCC.RankCandidate(Candidate)); return Candidate.getEditDistance(false) != TypoCorrection::InvalidDistance; } static void LookupPotentialTypoResult(Sema &SemaRef, LookupResult &Res, IdentifierInfo *Name, Scope *S, CXXScopeSpec *SS, DeclContext *MemberContext, bool EnteringContext, bool isObjCIvarLookup, bool FindHidden); /// \brief Check whether the declarations found for a typo correction are /// visible, and if none of them are, convert the correction to an 'import /// a module' correction. static void checkCorrectionVisibility(Sema &SemaRef, TypoCorrection &TC) { if (TC.begin() == TC.end()) return; TypoCorrection::decl_iterator DI = TC.begin(), DE = TC.end(); for (/**/; DI != DE; ++DI) if (!LookupResult::isVisible(SemaRef, *DI)) break; // Nothing to do if all decls are visible. if (DI == DE) return; llvm::SmallVector NewDecls(TC.begin(), DI); bool AnyVisibleDecls = !NewDecls.empty(); for (/**/; DI != DE; ++DI) { NamedDecl *VisibleDecl = *DI; if (!LookupResult::isVisible(SemaRef, *DI)) VisibleDecl = findAcceptableDecl(SemaRef, *DI); if (VisibleDecl) { if (!AnyVisibleDecls) { // Found a visible decl, discard all hidden ones. AnyVisibleDecls = true; NewDecls.clear(); } NewDecls.push_back(VisibleDecl); } else if (!AnyVisibleDecls && !(*DI)->isModulePrivate()) NewDecls.push_back(*DI); } if (NewDecls.empty()) TC = TypoCorrection(); else { TC.setCorrectionDecls(NewDecls); TC.setRequiresImport(!AnyVisibleDecls); } } // Fill the supplied vector with the IdentifierInfo pointers for each piece of // the given NestedNameSpecifier (i.e. given a NestedNameSpecifier "foo::bar::", // fill the vector with the IdentifierInfo pointers for "foo" and "bar"). static void getNestedNameSpecifierIdentifiers( NestedNameSpecifier *NNS, SmallVectorImpl &Identifiers) { if (NestedNameSpecifier *Prefix = NNS->getPrefix()) getNestedNameSpecifierIdentifiers(Prefix, Identifiers); else Identifiers.clear(); const IdentifierInfo *II = nullptr; switch (NNS->getKind()) { case NestedNameSpecifier::Identifier: II = NNS->getAsIdentifier(); break; case NestedNameSpecifier::Namespace: if (NNS->getAsNamespace()->isAnonymousNamespace()) return; II = NNS->getAsNamespace()->getIdentifier(); break; case NestedNameSpecifier::NamespaceAlias: II = NNS->getAsNamespaceAlias()->getIdentifier(); break; case NestedNameSpecifier::TypeSpecWithTemplate: case NestedNameSpecifier::TypeSpec: II = QualType(NNS->getAsType(), 0).getBaseTypeIdentifier(); break; case NestedNameSpecifier::Global: case NestedNameSpecifier::Super: return; } if (II) Identifiers.push_back(II); } void TypoCorrectionConsumer::FoundDecl(NamedDecl *ND, NamedDecl *Hiding, DeclContext *Ctx, bool InBaseClass) { // Don't consider hidden names for typo correction. if (Hiding) return; // Only consider entities with identifiers for names, ignoring // special names (constructors, overloaded operators, selectors, // etc.). IdentifierInfo *Name = ND->getIdentifier(); if (!Name) return; // Only consider visible declarations and declarations from modules with // names that exactly match. if (!LookupResult::isVisible(SemaRef, ND) && Name != Typo && !findAcceptableDecl(SemaRef, ND)) return; FoundName(Name->getName()); } void TypoCorrectionConsumer::FoundName(StringRef Name) { // Compute the edit distance between the typo and the name of this // entity, and add the identifier to the list of results. addName(Name, nullptr); } void TypoCorrectionConsumer::addKeywordResult(StringRef Keyword) { // Compute the edit distance between the typo and this keyword, // and add the keyword to the list of results. addName(Keyword, nullptr, nullptr, true); } void TypoCorrectionConsumer::addName(StringRef Name, NamedDecl *ND, NestedNameSpecifier *NNS, bool isKeyword) { // Use a simple length-based heuristic to determine the minimum possible // edit distance. If the minimum isn't good enough, bail out early. StringRef TypoStr = Typo->getName(); unsigned MinED = abs((int)Name.size() - (int)TypoStr.size()); if (MinED && TypoStr.size() / MinED < 3) return; // Compute an upper bound on the allowable edit distance, so that the // edit-distance algorithm can short-circuit. unsigned UpperBound = (TypoStr.size() + 2) / 3 + 1; unsigned ED = TypoStr.edit_distance(Name, true, UpperBound); if (ED >= UpperBound) return; TypoCorrection TC(&SemaRef.Context.Idents.get(Name), ND, NNS, ED); if (isKeyword) TC.makeKeyword(); TC.setCorrectionRange(nullptr, Result.getLookupNameInfo()); addCorrection(TC); } static const unsigned MaxTypoDistanceResultSets = 5; void TypoCorrectionConsumer::addCorrection(TypoCorrection Correction) { StringRef TypoStr = Typo->getName(); StringRef Name = Correction.getCorrectionAsIdentifierInfo()->getName(); // For very short typos, ignore potential corrections that have a different // base identifier from the typo or which have a normalized edit distance // longer than the typo itself. if (TypoStr.size() < 3 && (Name != TypoStr || Correction.getEditDistance(true) > TypoStr.size())) return; // If the correction is resolved but is not viable, ignore it. if (Correction.isResolved()) { checkCorrectionVisibility(SemaRef, Correction); if (!Correction || !isCandidateViable(*CorrectionValidator, Correction)) return; } TypoResultList &CList = CorrectionResults[Correction.getEditDistance(false)][Name]; if (!CList.empty() && !CList.back().isResolved()) CList.pop_back(); if (NamedDecl *NewND = Correction.getCorrectionDecl()) { std::string CorrectionStr = Correction.getAsString(SemaRef.getLangOpts()); for (TypoResultList::iterator RI = CList.begin(), RIEnd = CList.end(); RI != RIEnd; ++RI) { // If the Correction refers to a decl already in the result list, // replace the existing result if the string representation of Correction // comes before the current result alphabetically, then stop as there is // nothing more to be done to add Correction to the candidate set. if (RI->getCorrectionDecl() == NewND) { if (CorrectionStr < RI->getAsString(SemaRef.getLangOpts())) *RI = Correction; return; } } } if (CList.empty() || Correction.isResolved()) CList.push_back(Correction); while (CorrectionResults.size() > MaxTypoDistanceResultSets) CorrectionResults.erase(std::prev(CorrectionResults.end())); } void TypoCorrectionConsumer::addNamespaces( const llvm::MapVector &KnownNamespaces) { SearchNamespaces = true; for (auto KNPair : KnownNamespaces) Namespaces.addNameSpecifier(KNPair.first); bool SSIsTemplate = false; if (NestedNameSpecifier *NNS = (SS && SS->isValid()) ? SS->getScopeRep() : nullptr) { if (const Type *T = NNS->getAsType()) SSIsTemplate = T->getTypeClass() == Type::TemplateSpecialization; } // Do not transform this into an iterator-based loop. The loop body can // trigger the creation of further types (through lazy deserialization) and // invalide iterators into this list. auto &Types = SemaRef.getASTContext().getTypes(); for (unsigned I = 0; I != Types.size(); ++I) { const auto *TI = Types[I]; if (CXXRecordDecl *CD = TI->getAsCXXRecordDecl()) { CD = CD->getCanonicalDecl(); if (!CD->isDependentType() && !CD->isAnonymousStructOrUnion() && !CD->isUnion() && CD->getIdentifier() && (SSIsTemplate || !isa(CD)) && (CD->isBeingDefined() || CD->isCompleteDefinition())) Namespaces.addNameSpecifier(CD); } } } const TypoCorrection &TypoCorrectionConsumer::getNextCorrection() { if (++CurrentTCIndex < ValidatedCorrections.size()) return ValidatedCorrections[CurrentTCIndex]; CurrentTCIndex = ValidatedCorrections.size(); while (!CorrectionResults.empty()) { auto DI = CorrectionResults.begin(); if (DI->second.empty()) { CorrectionResults.erase(DI); continue; } auto RI = DI->second.begin(); if (RI->second.empty()) { DI->second.erase(RI); performQualifiedLookups(); continue; } TypoCorrection TC = RI->second.pop_back_val(); if (TC.isResolved() || TC.requiresImport() || resolveCorrection(TC)) { ValidatedCorrections.push_back(TC); return ValidatedCorrections[CurrentTCIndex]; } } return ValidatedCorrections[0]; // The empty correction. } bool TypoCorrectionConsumer::resolveCorrection(TypoCorrection &Candidate) { IdentifierInfo *Name = Candidate.getCorrectionAsIdentifierInfo(); DeclContext *TempMemberContext = MemberContext; CXXScopeSpec *TempSS = SS.get(); retry_lookup: LookupPotentialTypoResult(SemaRef, Result, Name, S, TempSS, TempMemberContext, EnteringContext, CorrectionValidator->IsObjCIvarLookup, Name == Typo && !Candidate.WillReplaceSpecifier()); switch (Result.getResultKind()) { case LookupResult::NotFound: case LookupResult::NotFoundInCurrentInstantiation: case LookupResult::FoundUnresolvedValue: if (TempSS) { // Immediately retry the lookup without the given CXXScopeSpec TempSS = nullptr; Candidate.WillReplaceSpecifier(true); goto retry_lookup; } if (TempMemberContext) { if (SS && !TempSS) TempSS = SS.get(); TempMemberContext = nullptr; goto retry_lookup; } if (SearchNamespaces) QualifiedResults.push_back(Candidate); break; case LookupResult::Ambiguous: // We don't deal with ambiguities. break; case LookupResult::Found: case LookupResult::FoundOverloaded: // Store all of the Decls for overloaded symbols for (auto *TRD : Result) Candidate.addCorrectionDecl(TRD); checkCorrectionVisibility(SemaRef, Candidate); if (!isCandidateViable(*CorrectionValidator, Candidate)) { if (SearchNamespaces) QualifiedResults.push_back(Candidate); break; } Candidate.setCorrectionRange(SS.get(), Result.getLookupNameInfo()); return true; } return false; } void TypoCorrectionConsumer::performQualifiedLookups() { unsigned TypoLen = Typo->getName().size(); for (const TypoCorrection &QR : QualifiedResults) { for (const auto &NSI : Namespaces) { DeclContext *Ctx = NSI.DeclCtx; const Type *NSType = NSI.NameSpecifier->getAsType(); // If the current NestedNameSpecifier refers to a class and the // current correction candidate is the name of that class, then skip // it as it is unlikely a qualified version of the class' constructor // is an appropriate correction. if (CXXRecordDecl *NSDecl = NSType ? NSType->getAsCXXRecordDecl() : nullptr) { if (NSDecl->getIdentifier() == QR.getCorrectionAsIdentifierInfo()) continue; } TypoCorrection TC(QR); TC.ClearCorrectionDecls(); TC.setCorrectionSpecifier(NSI.NameSpecifier); TC.setQualifierDistance(NSI.EditDistance); TC.setCallbackDistance(0); // Reset the callback distance // If the current correction candidate and namespace combination are // too far away from the original typo based on the normalized edit // distance, then skip performing a qualified name lookup. unsigned TmpED = TC.getEditDistance(true); if (QR.getCorrectionAsIdentifierInfo() != Typo && TmpED && TypoLen / TmpED < 3) continue; Result.clear(); Result.setLookupName(QR.getCorrectionAsIdentifierInfo()); if (!SemaRef.LookupQualifiedName(Result, Ctx)) continue; // Any corrections added below will be validated in subsequent // iterations of the main while() loop over the Consumer's contents. switch (Result.getResultKind()) { case LookupResult::Found: case LookupResult::FoundOverloaded: { if (SS && SS->isValid()) { std::string NewQualified = TC.getAsString(SemaRef.getLangOpts()); std::string OldQualified; llvm::raw_string_ostream OldOStream(OldQualified); SS->getScopeRep()->print(OldOStream, SemaRef.getPrintingPolicy()); OldOStream << Typo->getName(); // If correction candidate would be an identical written qualified // identifer, then the existing CXXScopeSpec probably included a // typedef that didn't get accounted for properly. if (OldOStream.str() == NewQualified) break; } for (LookupResult::iterator TRD = Result.begin(), TRDEnd = Result.end(); TRD != TRDEnd; ++TRD) { if (SemaRef.CheckMemberAccess(TC.getCorrectionRange().getBegin(), NSType ? NSType->getAsCXXRecordDecl() : nullptr, TRD.getPair()) == Sema::AR_accessible) TC.addCorrectionDecl(*TRD); } if (TC.isResolved()) { TC.setCorrectionRange(SS.get(), Result.getLookupNameInfo()); addCorrection(TC); } break; } case LookupResult::NotFound: case LookupResult::NotFoundInCurrentInstantiation: case LookupResult::Ambiguous: case LookupResult::FoundUnresolvedValue: break; } } } QualifiedResults.clear(); } TypoCorrectionConsumer::NamespaceSpecifierSet::NamespaceSpecifierSet( ASTContext &Context, DeclContext *CurContext, CXXScopeSpec *CurScopeSpec) : Context(Context), CurContextChain(buildContextChain(CurContext)) { if (NestedNameSpecifier *NNS = CurScopeSpec ? CurScopeSpec->getScopeRep() : nullptr) { llvm::raw_string_ostream SpecifierOStream(CurNameSpecifier); NNS->print(SpecifierOStream, Context.getPrintingPolicy()); getNestedNameSpecifierIdentifiers(NNS, CurNameSpecifierIdentifiers); } // Build the list of identifiers that would be used for an absolute // (from the global context) NestedNameSpecifier referring to the current // context. for (DeclContext *C : llvm::reverse(CurContextChain)) { if (auto *ND = dyn_cast_or_null(C)) CurContextIdentifiers.push_back(ND->getIdentifier()); } // Add the global context as a NestedNameSpecifier SpecifierInfo SI = {cast(Context.getTranslationUnitDecl()), NestedNameSpecifier::GlobalSpecifier(Context), 1}; DistanceMap[1].push_back(SI); } auto TypoCorrectionConsumer::NamespaceSpecifierSet::buildContextChain( DeclContext *Start) -> DeclContextList { assert(Start && "Building a context chain from a null context"); DeclContextList Chain; for (DeclContext *DC = Start->getPrimaryContext(); DC != nullptr; DC = DC->getLookupParent()) { NamespaceDecl *ND = dyn_cast_or_null(DC); if (!DC->isInlineNamespace() && !DC->isTransparentContext() && !(ND && ND->isAnonymousNamespace())) Chain.push_back(DC->getPrimaryContext()); } return Chain; } unsigned TypoCorrectionConsumer::NamespaceSpecifierSet::buildNestedNameSpecifier( DeclContextList &DeclChain, NestedNameSpecifier *&NNS) { unsigned NumSpecifiers = 0; for (DeclContext *C : llvm::reverse(DeclChain)) { if (auto *ND = dyn_cast_or_null(C)) { NNS = NestedNameSpecifier::Create(Context, NNS, ND); ++NumSpecifiers; } else if (auto *RD = dyn_cast_or_null(C)) { NNS = NestedNameSpecifier::Create(Context, NNS, RD->isTemplateDecl(), RD->getTypeForDecl()); ++NumSpecifiers; } } return NumSpecifiers; } void TypoCorrectionConsumer::NamespaceSpecifierSet::addNameSpecifier( DeclContext *Ctx) { NestedNameSpecifier *NNS = nullptr; unsigned NumSpecifiers = 0; DeclContextList NamespaceDeclChain(buildContextChain(Ctx)); DeclContextList FullNamespaceDeclChain(NamespaceDeclChain); // Eliminate common elements from the two DeclContext chains. for (DeclContext *C : llvm::reverse(CurContextChain)) { if (NamespaceDeclChain.empty() || NamespaceDeclChain.back() != C) break; NamespaceDeclChain.pop_back(); } // Build the NestedNameSpecifier from what is left of the NamespaceDeclChain NumSpecifiers = buildNestedNameSpecifier(NamespaceDeclChain, NNS); // Add an explicit leading '::' specifier if needed. if (NamespaceDeclChain.empty()) { // Rebuild the NestedNameSpecifier as a globally-qualified specifier. NNS = NestedNameSpecifier::GlobalSpecifier(Context); NumSpecifiers = buildNestedNameSpecifier(FullNamespaceDeclChain, NNS); } else if (NamedDecl *ND = dyn_cast_or_null(NamespaceDeclChain.back())) { IdentifierInfo *Name = ND->getIdentifier(); bool SameNameSpecifier = false; if (std::find(CurNameSpecifierIdentifiers.begin(), CurNameSpecifierIdentifiers.end(), Name) != CurNameSpecifierIdentifiers.end()) { std::string NewNameSpecifier; llvm::raw_string_ostream SpecifierOStream(NewNameSpecifier); SmallVector NewNameSpecifierIdentifiers; getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers); NNS->print(SpecifierOStream, Context.getPrintingPolicy()); SpecifierOStream.flush(); SameNameSpecifier = NewNameSpecifier == CurNameSpecifier; } if (SameNameSpecifier || std::find(CurContextIdentifiers.begin(), CurContextIdentifiers.end(), Name) != CurContextIdentifiers.end()) { // Rebuild the NestedNameSpecifier as a globally-qualified specifier. NNS = NestedNameSpecifier::GlobalSpecifier(Context); NumSpecifiers = buildNestedNameSpecifier(FullNamespaceDeclChain, NNS); } } // If the built NestedNameSpecifier would be replacing an existing // NestedNameSpecifier, use the number of component identifiers that // would need to be changed as the edit distance instead of the number // of components in the built NestedNameSpecifier. if (NNS && !CurNameSpecifierIdentifiers.empty()) { SmallVector NewNameSpecifierIdentifiers; getNestedNameSpecifierIdentifiers(NNS, NewNameSpecifierIdentifiers); NumSpecifiers = llvm::ComputeEditDistance( llvm::makeArrayRef(CurNameSpecifierIdentifiers), llvm::makeArrayRef(NewNameSpecifierIdentifiers)); } SpecifierInfo SI = {Ctx, NNS, NumSpecifiers}; DistanceMap[NumSpecifiers].push_back(SI); } /// \brief Perform name lookup for a possible result for typo correction. static void LookupPotentialTypoResult(Sema &SemaRef, LookupResult &Res, IdentifierInfo *Name, Scope *S, CXXScopeSpec *SS, DeclContext *MemberContext, bool EnteringContext, bool isObjCIvarLookup, bool FindHidden) { Res.suppressDiagnostics(); Res.clear(); Res.setLookupName(Name); Res.setAllowHidden(FindHidden); if (MemberContext) { if (ObjCInterfaceDecl *Class = dyn_cast(MemberContext)) { if (isObjCIvarLookup) { if (ObjCIvarDecl *Ivar = Class->lookupInstanceVariable(Name)) { Res.addDecl(Ivar); Res.resolveKind(); return; } } if (ObjCPropertyDecl *Prop = Class->FindPropertyDeclaration( Name, ObjCPropertyQueryKind::OBJC_PR_query_instance)) { Res.addDecl(Prop); Res.resolveKind(); return; } } SemaRef.LookupQualifiedName(Res, MemberContext); return; } SemaRef.LookupParsedName(Res, S, SS, /*AllowBuiltinCreation=*/false, EnteringContext); // Fake ivar lookup; this should really be part of // LookupParsedName. if (ObjCMethodDecl *Method = SemaRef.getCurMethodDecl()) { if (Method->isInstanceMethod() && Method->getClassInterface() && (Res.empty() || (Res.isSingleResult() && Res.getFoundDecl()->isDefinedOutsideFunctionOrMethod()))) { if (ObjCIvarDecl *IV = Method->getClassInterface()->lookupInstanceVariable(Name)) { Res.addDecl(IV); Res.resolveKind(); } } } } /// \brief Add keywords to the consumer as possible typo corrections. static void AddKeywordsToConsumer(Sema &SemaRef, TypoCorrectionConsumer &Consumer, Scope *S, CorrectionCandidateCallback &CCC, bool AfterNestedNameSpecifier) { if (AfterNestedNameSpecifier) { // For 'X::', we know exactly which keywords can appear next. Consumer.addKeywordResult("template"); if (CCC.WantExpressionKeywords) Consumer.addKeywordResult("operator"); return; } if (CCC.WantObjCSuper) Consumer.addKeywordResult("super"); if (CCC.WantTypeSpecifiers) { // Add type-specifier keywords to the set of results. static const char *const CTypeSpecs[] = { "char", "const", "double", "enum", "float", "int", "long", "short", "signed", "struct", "union", "unsigned", "void", "volatile", "_Complex", "_Imaginary", // storage-specifiers as well "extern", "inline", "static", "typedef" }; const unsigned NumCTypeSpecs = llvm::array_lengthof(CTypeSpecs); for (unsigned I = 0; I != NumCTypeSpecs; ++I) Consumer.addKeywordResult(CTypeSpecs[I]); if (SemaRef.getLangOpts().C99) Consumer.addKeywordResult("restrict"); if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) Consumer.addKeywordResult("bool"); else if (SemaRef.getLangOpts().C99) Consumer.addKeywordResult("_Bool"); if (SemaRef.getLangOpts().CPlusPlus) { Consumer.addKeywordResult("class"); Consumer.addKeywordResult("typename"); Consumer.addKeywordResult("wchar_t"); if (SemaRef.getLangOpts().CPlusPlus11) { Consumer.addKeywordResult("char16_t"); Consumer.addKeywordResult("char32_t"); Consumer.addKeywordResult("constexpr"); Consumer.addKeywordResult("decltype"); Consumer.addKeywordResult("thread_local"); } } if (SemaRef.getLangOpts().GNUMode) Consumer.addKeywordResult("typeof"); } else if (CCC.WantFunctionLikeCasts) { static const char *const CastableTypeSpecs[] = { "char", "double", "float", "int", "long", "short", "signed", "unsigned", "void" }; for (auto *kw : CastableTypeSpecs) Consumer.addKeywordResult(kw); } if (CCC.WantCXXNamedCasts && SemaRef.getLangOpts().CPlusPlus) { Consumer.addKeywordResult("const_cast"); Consumer.addKeywordResult("dynamic_cast"); Consumer.addKeywordResult("reinterpret_cast"); Consumer.addKeywordResult("static_cast"); } if (CCC.WantExpressionKeywords) { Consumer.addKeywordResult("sizeof"); if (SemaRef.getLangOpts().Bool || SemaRef.getLangOpts().CPlusPlus) { Consumer.addKeywordResult("false"); Consumer.addKeywordResult("true"); } if (SemaRef.getLangOpts().CPlusPlus) { static const char *const CXXExprs[] = { "delete", "new", "operator", "throw", "typeid" }; const unsigned NumCXXExprs = llvm::array_lengthof(CXXExprs); for (unsigned I = 0; I != NumCXXExprs; ++I) Consumer.addKeywordResult(CXXExprs[I]); if (isa(SemaRef.CurContext) && cast(SemaRef.CurContext)->isInstance()) Consumer.addKeywordResult("this"); if (SemaRef.getLangOpts().CPlusPlus11) { Consumer.addKeywordResult("alignof"); Consumer.addKeywordResult("nullptr"); } } if (SemaRef.getLangOpts().C11) { // FIXME: We should not suggest _Alignof if the alignof macro // is present. Consumer.addKeywordResult("_Alignof"); } } if (CCC.WantRemainingKeywords) { if (SemaRef.getCurFunctionOrMethodDecl() || SemaRef.getCurBlock()) { // Statements. static const char *const CStmts[] = { "do", "else", "for", "goto", "if", "return", "switch", "while" }; const unsigned NumCStmts = llvm::array_lengthof(CStmts); for (unsigned I = 0; I != NumCStmts; ++I) Consumer.addKeywordResult(CStmts[I]); if (SemaRef.getLangOpts().CPlusPlus) { Consumer.addKeywordResult("catch"); Consumer.addKeywordResult("try"); } if (S && S->getBreakParent()) Consumer.addKeywordResult("break"); if (S && S->getContinueParent()) Consumer.addKeywordResult("continue"); if (!SemaRef.getCurFunction()->SwitchStack.empty()) { Consumer.addKeywordResult("case"); Consumer.addKeywordResult("default"); } } else { if (SemaRef.getLangOpts().CPlusPlus) { Consumer.addKeywordResult("namespace"); Consumer.addKeywordResult("template"); } if (S && S->isClassScope()) { Consumer.addKeywordResult("explicit"); Consumer.addKeywordResult("friend"); Consumer.addKeywordResult("mutable"); Consumer.addKeywordResult("private"); Consumer.addKeywordResult("protected"); Consumer.addKeywordResult("public"); Consumer.addKeywordResult("virtual"); } } if (SemaRef.getLangOpts().CPlusPlus) { Consumer.addKeywordResult("using"); if (SemaRef.getLangOpts().CPlusPlus11) Consumer.addKeywordResult("static_assert"); } } } std::unique_ptr Sema::makeTypoCorrectionConsumer( const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, Scope *S, CXXScopeSpec *SS, std::unique_ptr CCC, DeclContext *MemberContext, bool EnteringContext, const ObjCObjectPointerType *OPT, bool ErrorRecovery) { if (Diags.hasFatalErrorOccurred() || !getLangOpts().SpellChecking || DisableTypoCorrection) return nullptr; // In Microsoft mode, don't perform typo correction in a template member // function dependent context because it interferes with the "lookup into // dependent bases of class templates" feature. if (getLangOpts().MSVCCompat && CurContext->isDependentContext() && isa(CurContext)) return nullptr; // We only attempt to correct typos for identifiers. IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); if (!Typo) return nullptr; // If the scope specifier itself was invalid, don't try to correct // typos. if (SS && SS->isInvalid()) return nullptr; // Never try to correct typos during template deduction or // instantiation. if (!ActiveTemplateInstantiations.empty()) return nullptr; // Don't try to correct 'super'. if (S && S->isInObjcMethodScope() && Typo == getSuperIdentifier()) return nullptr; // Abort if typo correction already failed for this specific typo. IdentifierSourceLocations::iterator locs = TypoCorrectionFailures.find(Typo); if (locs != TypoCorrectionFailures.end() && locs->second.count(TypoName.getLoc())) return nullptr; // Don't try to correct the identifier "vector" when in AltiVec mode. // TODO: Figure out why typo correction misbehaves in this case, fix it, and // remove this workaround. if ((getLangOpts().AltiVec || getLangOpts().ZVector) && Typo->isStr("vector")) return nullptr; // Provide a stop gap for files that are just seriously broken. Trying // to correct all typos can turn into a HUGE performance penalty, causing // some files to take minutes to get rejected by the parser. unsigned Limit = getDiagnostics().getDiagnosticOptions().SpellCheckingLimit; if (Limit && TyposCorrected >= Limit) return nullptr; ++TyposCorrected; // If we're handling a missing symbol error, using modules, and the // special search all modules option is used, look for a missing import. if (ErrorRecovery && getLangOpts().Modules && getLangOpts().ModulesSearchAll) { // The following has the side effect of loading the missing module. getModuleLoader().lookupMissingImports(Typo->getName(), TypoName.getLocStart()); } CorrectionCandidateCallback &CCCRef = *CCC; auto Consumer = llvm::make_unique( *this, TypoName, LookupKind, S, SS, std::move(CCC), MemberContext, EnteringContext); // Perform name lookup to find visible, similarly-named entities. bool IsUnqualifiedLookup = false; DeclContext *QualifiedDC = MemberContext; if (MemberContext) { LookupVisibleDecls(MemberContext, LookupKind, *Consumer); // Look in qualified interfaces. if (OPT) { for (auto *I : OPT->quals()) LookupVisibleDecls(I, LookupKind, *Consumer); } } else if (SS && SS->isSet()) { QualifiedDC = computeDeclContext(*SS, EnteringContext); if (!QualifiedDC) return nullptr; LookupVisibleDecls(QualifiedDC, LookupKind, *Consumer); } else { IsUnqualifiedLookup = true; } // Determine whether we are going to search in the various namespaces for // corrections. bool SearchNamespaces = getLangOpts().CPlusPlus && (IsUnqualifiedLookup || (SS && SS->isSet())); if (IsUnqualifiedLookup || SearchNamespaces) { // For unqualified lookup, look through all of the names that we have // seen in this translation unit. // FIXME: Re-add the ability to skip very unlikely potential corrections. for (const auto &I : Context.Idents) Consumer->FoundName(I.getKey()); // Walk through identifiers in external identifier sources. // FIXME: Re-add the ability to skip very unlikely potential corrections. if (IdentifierInfoLookup *External = Context.Idents.getExternalIdentifierLookup()) { std::unique_ptr Iter(External->getIdentifiers()); do { StringRef Name = Iter->Next(); if (Name.empty()) break; Consumer->FoundName(Name); } while (true); } } AddKeywordsToConsumer(*this, *Consumer, S, CCCRef, SS && SS->isNotEmpty()); // Build the NestedNameSpecifiers for the KnownNamespaces, if we're going // to search those namespaces. if (SearchNamespaces) { // Load any externally-known namespaces. if (ExternalSource && !LoadedExternalKnownNamespaces) { SmallVector ExternalKnownNamespaces; LoadedExternalKnownNamespaces = true; ExternalSource->ReadKnownNamespaces(ExternalKnownNamespaces); for (auto *N : ExternalKnownNamespaces) KnownNamespaces[N] = true; } Consumer->addNamespaces(KnownNamespaces); } return Consumer; } /// \brief Try to "correct" a typo in the source code by finding /// visible declarations whose names are similar to the name that was /// present in the source code. /// /// \param TypoName the \c DeclarationNameInfo structure that contains /// the name that was present in the source code along with its location. /// /// \param LookupKind the name-lookup criteria used to search for the name. /// /// \param S the scope in which name lookup occurs. /// /// \param SS the nested-name-specifier that precedes the name we're /// looking for, if present. /// /// \param CCC A CorrectionCandidateCallback object that provides further /// validation of typo correction candidates. It also provides flags for /// determining the set of keywords permitted. /// /// \param MemberContext if non-NULL, the context in which to look for /// a member access expression. /// /// \param EnteringContext whether we're entering the context described by /// the nested-name-specifier SS. /// /// \param OPT when non-NULL, the search for visible declarations will /// also walk the protocols in the qualified interfaces of \p OPT. /// /// \returns a \c TypoCorrection containing the corrected name if the typo /// along with information such as the \c NamedDecl where the corrected name /// was declared, and any additional \c NestedNameSpecifier needed to access /// it (C++ only). The \c TypoCorrection is empty if there is no correction. TypoCorrection Sema::CorrectTypo(const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, Scope *S, CXXScopeSpec *SS, std::unique_ptr CCC, CorrectTypoKind Mode, DeclContext *MemberContext, bool EnteringContext, const ObjCObjectPointerType *OPT, bool RecordFailure) { assert(CCC && "CorrectTypo requires a CorrectionCandidateCallback"); // Always let the ExternalSource have the first chance at correction, even // if we would otherwise have given up. if (ExternalSource) { if (TypoCorrection Correction = ExternalSource->CorrectTypo( TypoName, LookupKind, S, SS, *CCC, MemberContext, EnteringContext, OPT)) return Correction; } // Ugly hack equivalent to CTC == CTC_ObjCMessageReceiver; // WantObjCSuper is only true for CTC_ObjCMessageReceiver and for // some instances of CTC_Unknown, while WantRemainingKeywords is true // for CTC_Unknown but not for CTC_ObjCMessageReceiver. bool ObjCMessageReceiver = CCC->WantObjCSuper && !CCC->WantRemainingKeywords; IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); auto Consumer = makeTypoCorrectionConsumer( TypoName, LookupKind, S, SS, std::move(CCC), MemberContext, EnteringContext, OPT, Mode == CTK_ErrorRecovery); if (!Consumer) return TypoCorrection(); // If we haven't found anything, we're done. if (Consumer->empty()) return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); // Make sure the best edit distance (prior to adding any namespace qualifiers) // is not more that about a third of the length of the typo's identifier. unsigned ED = Consumer->getBestEditDistance(true); unsigned TypoLen = Typo->getName().size(); if (ED > 0 && TypoLen / ED < 3) return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); TypoCorrection BestTC = Consumer->getNextCorrection(); TypoCorrection SecondBestTC = Consumer->getNextCorrection(); if (!BestTC) return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); ED = BestTC.getEditDistance(); if (TypoLen >= 3 && ED > 0 && TypoLen / ED < 3) { // If this was an unqualified lookup and we believe the callback // object wouldn't have filtered out possible corrections, note // that no correction was found. return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); } // If only a single name remains, return that result. if (!SecondBestTC || SecondBestTC.getEditDistance(false) > BestTC.getEditDistance(false)) { const TypoCorrection &Result = BestTC; // Don't correct to a keyword that's the same as the typo; the keyword // wasn't actually in scope. if (ED == 0 && Result.isKeyword()) return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); TypoCorrection TC = Result; TC.setCorrectionRange(SS, TypoName); checkCorrectionVisibility(*this, TC); return TC; } else if (SecondBestTC && ObjCMessageReceiver) { // Prefer 'super' when we're completing in a message-receiver // context. if (BestTC.getCorrection().getAsString() != "super") { if (SecondBestTC.getCorrection().getAsString() == "super") BestTC = SecondBestTC; else if ((*Consumer)["super"].front().isKeyword()) BestTC = (*Consumer)["super"].front(); } // Don't correct to a keyword that's the same as the typo; the keyword // wasn't actually in scope. if (BestTC.getEditDistance() == 0 || BestTC.getCorrection().getAsString() != "super") return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure); BestTC.setCorrectionRange(SS, TypoName); return BestTC; } // Record the failure's location if needed and return an empty correction. If // this was an unqualified lookup and we believe the callback object did not // filter out possible corrections, also cache the failure for the typo. return FailedCorrection(Typo, TypoName.getLoc(), RecordFailure && !SecondBestTC); } /// \brief Try to "correct" a typo in the source code by finding /// visible declarations whose names are similar to the name that was /// present in the source code. /// /// \param TypoName the \c DeclarationNameInfo structure that contains /// the name that was present in the source code along with its location. /// /// \param LookupKind the name-lookup criteria used to search for the name. /// /// \param S the scope in which name lookup occurs. /// /// \param SS the nested-name-specifier that precedes the name we're /// looking for, if present. /// /// \param CCC A CorrectionCandidateCallback object that provides further /// validation of typo correction candidates. It also provides flags for /// determining the set of keywords permitted. /// /// \param TDG A TypoDiagnosticGenerator functor that will be used to print /// diagnostics when the actual typo correction is attempted. /// /// \param TRC A TypoRecoveryCallback functor that will be used to build an /// Expr from a typo correction candidate. /// /// \param MemberContext if non-NULL, the context in which to look for /// a member access expression. /// /// \param EnteringContext whether we're entering the context described by /// the nested-name-specifier SS. /// /// \param OPT when non-NULL, the search for visible declarations will /// also walk the protocols in the qualified interfaces of \p OPT. /// /// \returns a new \c TypoExpr that will later be replaced in the AST with an /// Expr representing the result of performing typo correction, or nullptr if /// typo correction is not possible. If nullptr is returned, no diagnostics will /// be emitted and it is the responsibility of the caller to emit any that are /// needed. TypoExpr *Sema::CorrectTypoDelayed( const DeclarationNameInfo &TypoName, Sema::LookupNameKind LookupKind, Scope *S, CXXScopeSpec *SS, std::unique_ptr CCC, TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC, CorrectTypoKind Mode, DeclContext *MemberContext, bool EnteringContext, const ObjCObjectPointerType *OPT) { assert(CCC && "CorrectTypoDelayed requires a CorrectionCandidateCallback"); auto Consumer = makeTypoCorrectionConsumer( TypoName, LookupKind, S, SS, std::move(CCC), MemberContext, EnteringContext, OPT, Mode == CTK_ErrorRecovery); // Give the external sema source a chance to correct the typo. TypoCorrection ExternalTypo; if (ExternalSource && Consumer) { ExternalTypo = ExternalSource->CorrectTypo( TypoName, LookupKind, S, SS, *Consumer->getCorrectionValidator(), MemberContext, EnteringContext, OPT); if (ExternalTypo) Consumer->addCorrection(ExternalTypo); } if (!Consumer || Consumer->empty()) return nullptr; // Make sure the best edit distance (prior to adding any namespace qualifiers) // is not more that about a third of the length of the typo's identifier. unsigned ED = Consumer->getBestEditDistance(true); IdentifierInfo *Typo = TypoName.getName().getAsIdentifierInfo(); if (!ExternalTypo && ED > 0 && Typo->getName().size() / ED < 3) return nullptr; ExprEvalContexts.back().NumTypos++; return createDelayedTypo(std::move(Consumer), std::move(TDG), std::move(TRC)); } void TypoCorrection::addCorrectionDecl(NamedDecl *CDecl) { if (!CDecl) return; if (isKeyword()) CorrectionDecls.clear(); CorrectionDecls.push_back(CDecl); if (!CorrectionName) CorrectionName = CDecl->getDeclName(); } std::string TypoCorrection::getAsString(const LangOptions &LO) const { if (CorrectionNameSpec) { std::string tmpBuffer; llvm::raw_string_ostream PrefixOStream(tmpBuffer); CorrectionNameSpec->print(PrefixOStream, PrintingPolicy(LO)); PrefixOStream << CorrectionName; return PrefixOStream.str(); } return CorrectionName.getAsString(); } bool CorrectionCandidateCallback::ValidateCandidate( const TypoCorrection &candidate) { if (!candidate.isResolved()) return true; if (candidate.isKeyword()) return WantTypeSpecifiers || WantExpressionKeywords || WantCXXNamedCasts || WantRemainingKeywords || WantObjCSuper; bool HasNonType = false; bool HasStaticMethod = false; bool HasNonStaticMethod = false; for (Decl *D : candidate) { if (FunctionTemplateDecl *FTD = dyn_cast(D)) D = FTD->getTemplatedDecl(); if (CXXMethodDecl *Method = dyn_cast(D)) { if (Method->isStatic()) HasStaticMethod = true; else HasNonStaticMethod = true; } if (!isa(D)) HasNonType = true; } if (IsAddressOfOperand && HasNonStaticMethod && !HasStaticMethod && !candidate.getCorrectionSpecifier()) return false; return WantTypeSpecifiers || HasNonType; } FunctionCallFilterCCC::FunctionCallFilterCCC(Sema &SemaRef, unsigned NumArgs, bool HasExplicitTemplateArgs, MemberExpr *ME) : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs), CurContext(SemaRef.CurContext), MemberFn(ME) { WantTypeSpecifiers = false; WantFunctionLikeCasts = SemaRef.getLangOpts().CPlusPlus && NumArgs == 1; WantRemainingKeywords = false; } bool FunctionCallFilterCCC::ValidateCandidate(const TypoCorrection &candidate) { if (!candidate.getCorrectionDecl()) return candidate.isKeyword(); for (auto *C : candidate) { FunctionDecl *FD = nullptr; NamedDecl *ND = C->getUnderlyingDecl(); if (FunctionTemplateDecl *FTD = dyn_cast(ND)) FD = FTD->getTemplatedDecl(); if (!HasExplicitTemplateArgs && !FD) { if (!(FD = dyn_cast(ND)) && isa(ND)) { // If the Decl is neither a function nor a template function, // determine if it is a pointer or reference to a function. If so, // check against the number of arguments expected for the pointee. QualType ValType = cast(ND)->getType(); if (ValType->isAnyPointerType() || ValType->isReferenceType()) ValType = ValType->getPointeeType(); if (const FunctionProtoType *FPT = ValType->getAs()) if (FPT->getNumParams() == NumArgs) return true; } } // Skip the current candidate if it is not a FunctionDecl or does not accept // the current number of arguments. if (!FD || !(FD->getNumParams() >= NumArgs && FD->getMinRequiredArguments() <= NumArgs)) continue; // If the current candidate is a non-static C++ method, skip the candidate // unless the method being corrected--or the current DeclContext, if the // function being corrected is not a method--is a method in the same class // or a descendent class of the candidate's parent class. if (CXXMethodDecl *MD = dyn_cast(FD)) { if (MemberFn || !MD->isStatic()) { CXXMethodDecl *CurMD = MemberFn ? dyn_cast_or_null(MemberFn->getMemberDecl()) : dyn_cast_or_null(CurContext); CXXRecordDecl *CurRD = CurMD ? CurMD->getParent()->getCanonicalDecl() : nullptr; CXXRecordDecl *RD = MD->getParent()->getCanonicalDecl(); if (!CurRD || (CurRD != RD && !CurRD->isDerivedFrom(RD))) continue; } } return true; } return false; } void Sema::diagnoseTypo(const TypoCorrection &Correction, const PartialDiagnostic &TypoDiag, bool ErrorRecovery) { diagnoseTypo(Correction, TypoDiag, PDiag(diag::note_previous_decl), ErrorRecovery); } /// Find which declaration we should import to provide the definition of /// the given declaration. static NamedDecl *getDefinitionToImport(NamedDecl *D) { if (VarDecl *VD = dyn_cast(D)) return VD->getDefinition(); if (FunctionDecl *FD = dyn_cast(D)) return FD->getDefinition(); if (TagDecl *TD = dyn_cast(D)) return TD->getDefinition(); if (ObjCInterfaceDecl *ID = dyn_cast(D)) return ID->getDefinition(); if (ObjCProtocolDecl *PD = dyn_cast(D)) return PD->getDefinition(); if (TemplateDecl *TD = dyn_cast(D)) return getDefinitionToImport(TD->getTemplatedDecl()); return nullptr; } void Sema::diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl, MissingImportKind MIK, bool Recover) { assert(!isVisible(Decl) && "missing import for non-hidden decl?"); // Suggest importing a module providing the definition of this entity, if // possible. NamedDecl *Def = getDefinitionToImport(Decl); if (!Def) Def = Decl; Module *Owner = getOwningModule(Decl); assert(Owner && "definition of hidden declaration is not in a module"); llvm::SmallVector OwningModules; OwningModules.push_back(Owner); auto Merged = Context.getModulesWithMergedDefinition(Decl); OwningModules.insert(OwningModules.end(), Merged.begin(), Merged.end()); diagnoseMissingImport(Loc, Decl, Decl->getLocation(), OwningModules, MIK, Recover); } /// \brief Get a "quoted.h" or include path to use in a diagnostic /// suggesting the addition of a #include of the specified file. static std::string getIncludeStringForHeader(Preprocessor &PP, const FileEntry *E) { bool IsSystem; auto Path = PP.getHeaderSearchInfo().suggestPathToFileForDiagnostics(E, &IsSystem); return (IsSystem ? '<' : '"') + Path + (IsSystem ? '>' : '"'); } void Sema::diagnoseMissingImport(SourceLocation UseLoc, NamedDecl *Decl, SourceLocation DeclLoc, ArrayRef Modules, MissingImportKind MIK, bool Recover) { assert(!Modules.empty()); if (Modules.size() > 1) { std::string ModuleList; unsigned N = 0; for (Module *M : Modules) { ModuleList += "\n "; if (++N == 5 && N != Modules.size()) { ModuleList += "[...]"; break; } ModuleList += M->getFullModuleName(); } Diag(UseLoc, diag::err_module_unimported_use_multiple) << (int)MIK << Decl << ModuleList; } else if (const FileEntry *E = PP.getModuleHeaderToIncludeForDiagnostics(UseLoc, DeclLoc)) { // The right way to make the declaration visible is to include a header; // suggest doing so. // // FIXME: Find a smart place to suggest inserting a #include, and add // a FixItHint there. Diag(UseLoc, diag::err_module_unimported_use_header) << (int)MIK << Decl << Modules[0]->getFullModuleName() << getIncludeStringForHeader(PP, E); } else { // FIXME: Add a FixItHint that imports the corresponding module. Diag(UseLoc, diag::err_module_unimported_use) << (int)MIK << Decl << Modules[0]->getFullModuleName(); } unsigned DiagID; switch (MIK) { case MissingImportKind::Declaration: DiagID = diag::note_previous_declaration; break; case MissingImportKind::Definition: DiagID = diag::note_previous_definition; break; case MissingImportKind::DefaultArgument: DiagID = diag::note_default_argument_declared_here; break; case MissingImportKind::ExplicitSpecialization: DiagID = diag::note_explicit_specialization_declared_here; break; case MissingImportKind::PartialSpecialization: DiagID = diag::note_partial_specialization_declared_here; break; } Diag(DeclLoc, DiagID); // Try to recover by implicitly importing this module. if (Recover) createImplicitModuleImportForErrorRecovery(UseLoc, Modules[0]); } /// \brief Diagnose a successfully-corrected typo. Separated from the correction /// itself to allow external validation of the result, etc. /// /// \param Correction The result of performing typo correction. /// \param TypoDiag The diagnostic to produce. This will have the corrected /// string added to it (and usually also a fixit). /// \param PrevNote A note to use when indicating the location of the entity to /// which we are correcting. Will have the correction string added to it. /// \param ErrorRecovery If \c true (the default), the caller is going to /// recover from the typo as if the corrected string had been typed. /// In this case, \c PDiag must be an error, and we will attach a fixit /// to it. void Sema::diagnoseTypo(const TypoCorrection &Correction, const PartialDiagnostic &TypoDiag, const PartialDiagnostic &PrevNote, bool ErrorRecovery) { std::string CorrectedStr = Correction.getAsString(getLangOpts()); std::string CorrectedQuotedStr = Correction.getQuoted(getLangOpts()); FixItHint FixTypo = FixItHint::CreateReplacement( Correction.getCorrectionRange(), CorrectedStr); // Maybe we're just missing a module import. if (Correction.requiresImport()) { NamedDecl *Decl = Correction.getFoundDecl(); assert(Decl && "import required but no declaration to import"); diagnoseMissingImport(Correction.getCorrectionRange().getBegin(), Decl, MissingImportKind::Declaration, ErrorRecovery); return; } Diag(Correction.getCorrectionRange().getBegin(), TypoDiag) << CorrectedQuotedStr << (ErrorRecovery ? FixTypo : FixItHint()); NamedDecl *ChosenDecl = Correction.isKeyword() ? nullptr : Correction.getFoundDecl(); if (PrevNote.getDiagID() && ChosenDecl) Diag(ChosenDecl->getLocation(), PrevNote) << CorrectedQuotedStr << (ErrorRecovery ? FixItHint() : FixTypo); } TypoExpr *Sema::createDelayedTypo(std::unique_ptr TCC, TypoDiagnosticGenerator TDG, TypoRecoveryCallback TRC) { assert(TCC && "createDelayedTypo requires a valid TypoCorrectionConsumer"); auto TE = new (Context) TypoExpr(Context.DependentTy); auto &State = DelayedTypos[TE]; State.Consumer = std::move(TCC); State.DiagHandler = std::move(TDG); State.RecoveryHandler = std::move(TRC); return TE; } const Sema::TypoExprState &Sema::getTypoExprState(TypoExpr *TE) const { auto Entry = DelayedTypos.find(TE); assert(Entry != DelayedTypos.end() && "Failed to get the state for a TypoExpr!"); return Entry->second; } void Sema::clearDelayedTypo(TypoExpr *TE) { DelayedTypos.erase(TE); } void Sema::ActOnPragmaDump(Scope *S, SourceLocation IILoc, IdentifierInfo *II) { DeclarationNameInfo Name(II, IILoc); LookupResult R(*this, Name, LookupAnyName, Sema::NotForRedeclaration); R.suppressDiagnostics(); R.setHideTags(false); LookupName(R, S); R.dump(); }