//===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements semantic analysis for C++ declarations. // //===----------------------------------------------------------------------===// #include "clang/Sema/SemaInternal.h" #include "clang/AST/ASTConsumer.h" #include "clang/AST/ASTContext.h" #include "clang/AST/ASTLambda.h" #include "clang/AST/ASTMutationListener.h" #include "clang/AST/CXXInheritance.h" #include "clang/AST/CharUnits.h" #include "clang/AST/EvaluatedExprVisitor.h" #include "clang/AST/ExprCXX.h" #include "clang/AST/RecordLayout.h" #include "clang/AST/RecursiveASTVisitor.h" #include "clang/AST/StmtVisitor.h" #include "clang/AST/TypeLoc.h" #include "clang/AST/TypeOrdering.h" #include "clang/Basic/PartialDiagnostic.h" #include "clang/Basic/TargetInfo.h" #include "clang/Lex/LiteralSupport.h" #include "clang/Lex/Preprocessor.h" #include "clang/Sema/CXXFieldCollector.h" #include "clang/Sema/DeclSpec.h" #include "clang/Sema/Initialization.h" #include "clang/Sema/Lookup.h" #include "clang/Sema/ParsedTemplate.h" #include "clang/Sema/Scope.h" #include "clang/Sema/ScopeInfo.h" #include "clang/Sema/Template.h" #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/SmallString.h" #include <map> #include <set> using namespace clang; //===----------------------------------------------------------------------===// // CheckDefaultArgumentVisitor //===----------------------------------------------------------------------===// namespace { /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses /// the default argument of a parameter to determine whether it /// contains any ill-formed subexpressions. For example, this will /// diagnose the use of local variables or parameters within the /// default argument expression. class CheckDefaultArgumentVisitor : public StmtVisitor<CheckDefaultArgumentVisitor, bool> { Expr *DefaultArg; Sema *S; public: CheckDefaultArgumentVisitor(Expr *defarg, Sema *s) : DefaultArg(defarg), S(s) {} bool VisitExpr(Expr *Node); bool VisitDeclRefExpr(DeclRefExpr *DRE); bool VisitCXXThisExpr(CXXThisExpr *ThisE); bool VisitLambdaExpr(LambdaExpr *Lambda); bool VisitPseudoObjectExpr(PseudoObjectExpr *POE); }; /// VisitExpr - Visit all of the children of this expression. bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) { bool IsInvalid = false; for (Stmt *SubStmt : Node->children()) IsInvalid |= Visit(SubStmt); return IsInvalid; } /// VisitDeclRefExpr - Visit a reference to a declaration, to /// determine whether this declaration can be used in the default /// argument expression. bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) { NamedDecl *Decl = DRE->getDecl(); if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) { // C++ [dcl.fct.default]p9 // Default arguments are evaluated each time the function is // called. The order of evaluation of function arguments is // unspecified. Consequently, parameters of a function shall not // be used in default argument expressions, even if they are not // evaluated. Parameters of a function declared before a default // argument expression are in scope and can hide namespace and // class member names. return S->Diag(DRE->getLocStart(), diag::err_param_default_argument_references_param) << Param->getDeclName() << DefaultArg->getSourceRange(); } else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) { // C++ [dcl.fct.default]p7 // Local variables shall not be used in default argument // expressions. if (VDecl->isLocalVarDecl()) return S->Diag(DRE->getLocStart(), diag::err_param_default_argument_references_local) << VDecl->getDeclName() << DefaultArg->getSourceRange(); } return false; } /// VisitCXXThisExpr - Visit a C++ "this" expression. bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) { // C++ [dcl.fct.default]p8: // The keyword this shall not be used in a default argument of a // member function. return S->Diag(ThisE->getLocStart(), diag::err_param_default_argument_references_this) << ThisE->getSourceRange(); } bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr(PseudoObjectExpr *POE) { bool Invalid = false; for (PseudoObjectExpr::semantics_iterator i = POE->semantics_begin(), e = POE->semantics_end(); i != e; ++i) { Expr *E = *i; // Look through bindings. if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) { E = OVE->getSourceExpr(); assert(E && "pseudo-object binding without source expression?"); } Invalid |= Visit(E); } return Invalid; } bool CheckDefaultArgumentVisitor::VisitLambdaExpr(LambdaExpr *Lambda) { // C++11 [expr.lambda.prim]p13: // A lambda-expression appearing in a default argument shall not // implicitly or explicitly capture any entity. if (Lambda->capture_begin() == Lambda->capture_end()) return false; return S->Diag(Lambda->getLocStart(), diag::err_lambda_capture_default_arg); } } void Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc, const CXXMethodDecl *Method) { // If we have an MSAny spec already, don't bother. if (!Method || ComputedEST == EST_MSAny) return; const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); Proto = Self->ResolveExceptionSpec(CallLoc, Proto); if (!Proto) return; ExceptionSpecificationType EST = Proto->getExceptionSpecType(); // If we have a throw-all spec at this point, ignore the function. if (ComputedEST == EST_None) return; switch(EST) { // If this function can throw any exceptions, make a note of that. case EST_MSAny: case EST_None: ClearExceptions(); ComputedEST = EST; return; // FIXME: If the call to this decl is using any of its default arguments, we // need to search them for potentially-throwing calls. // If this function has a basic noexcept, it doesn't affect the outcome. case EST_BasicNoexcept: return; // If we're still at noexcept(true) and there's a nothrow() callee, // change to that specification. case EST_DynamicNone: if (ComputedEST == EST_BasicNoexcept) ComputedEST = EST_DynamicNone; return; // Check out noexcept specs. case EST_ComputedNoexcept: { FunctionProtoType::NoexceptResult NR = Proto->getNoexceptSpec(Self->Context); assert(NR != FunctionProtoType::NR_NoNoexcept && "Must have noexcept result for EST_ComputedNoexcept."); assert(NR != FunctionProtoType::NR_Dependent && "Should not generate implicit declarations for dependent cases, " "and don't know how to handle them anyway."); // noexcept(false) -> no spec on the new function if (NR == FunctionProtoType::NR_Throw) { ClearExceptions(); ComputedEST = EST_None; } // noexcept(true) won't change anything either. return; } default: break; } assert(EST == EST_Dynamic && "EST case not considered earlier."); assert(ComputedEST != EST_None && "Shouldn't collect exceptions when throw-all is guaranteed."); ComputedEST = EST_Dynamic; // Record the exceptions in this function's exception specification. for (const auto &E : Proto->exceptions()) if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second) Exceptions.push_back(E); } void Sema::ImplicitExceptionSpecification::CalledExpr(Expr *E) { if (!E || ComputedEST == EST_MSAny) return; // FIXME: // // C++0x [except.spec]p14: // [An] implicit exception-specification specifies the type-id T if and // only if T is allowed by the exception-specification of a function directly // invoked by f's implicit definition; f shall allow all exceptions if any // function it directly invokes allows all exceptions, and f shall allow no // exceptions if every function it directly invokes allows no exceptions. // // Note in particular that if an implicit exception-specification is generated // for a function containing a throw-expression, that specification can still // be noexcept(true). // // Note also that 'directly invoked' is not defined in the standard, and there // is no indication that we should only consider potentially-evaluated calls. // // Ultimately we should implement the intent of the standard: the exception // specification should be the set of exceptions which can be thrown by the // implicit definition. For now, we assume that any non-nothrow expression can // throw any exception. if (Self->canThrow(E)) ComputedEST = EST_None; } bool Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg, SourceLocation EqualLoc) { if (RequireCompleteType(Param->getLocation(), Param->getType(), diag::err_typecheck_decl_incomplete_type)) { Param->setInvalidDecl(); return true; } // C++ [dcl.fct.default]p5 // A default argument expression is implicitly converted (clause // 4) to the parameter type. The default argument expression has // the same semantic constraints as the initializer expression in // a declaration of a variable of the parameter type, using the // copy-initialization semantics (8.5). InitializedEntity Entity = InitializedEntity::InitializeParameter(Context, Param); InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(), EqualLoc); InitializationSequence InitSeq(*this, Entity, Kind, Arg); ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg); if (Result.isInvalid()) return true; Arg = Result.getAs<Expr>(); CheckCompletedExpr(Arg, EqualLoc); Arg = MaybeCreateExprWithCleanups(Arg); // Okay: add the default argument to the parameter Param->setDefaultArg(Arg); // We have already instantiated this parameter; provide each of the // instantiations with the uninstantiated default argument. UnparsedDefaultArgInstantiationsMap::iterator InstPos = UnparsedDefaultArgInstantiations.find(Param); if (InstPos != UnparsedDefaultArgInstantiations.end()) { for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I) InstPos->second[I]->setUninstantiatedDefaultArg(Arg); // We're done tracking this parameter's instantiations. UnparsedDefaultArgInstantiations.erase(InstPos); } return false; } /// ActOnParamDefaultArgument - Check whether the default argument /// provided for a function parameter is well-formed. If so, attach it /// to the parameter declaration. void Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc, Expr *DefaultArg) { if (!param || !DefaultArg) return; ParmVarDecl *Param = cast<ParmVarDecl>(param); UnparsedDefaultArgLocs.erase(Param); // Default arguments are only permitted in C++ if (!getLangOpts().CPlusPlus) { Diag(EqualLoc, diag::err_param_default_argument) << DefaultArg->getSourceRange(); Param->setInvalidDecl(); return; } // Check for unexpanded parameter packs. if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) { Param->setInvalidDecl(); return; } // C++11 [dcl.fct.default]p3 // A default argument expression [...] shall not be specified for a // parameter pack. if (Param->isParameterPack()) { Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack) << DefaultArg->getSourceRange(); return; } // Check that the default argument is well-formed CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg, this); if (DefaultArgChecker.Visit(DefaultArg)) { Param->setInvalidDecl(); return; } SetParamDefaultArgument(Param, DefaultArg, EqualLoc); } /// ActOnParamUnparsedDefaultArgument - We've seen a default /// argument for a function parameter, but we can't parse it yet /// because we're inside a class definition. Note that this default /// argument will be parsed later. void Sema::ActOnParamUnparsedDefaultArgument(Decl *param, SourceLocation EqualLoc, SourceLocation ArgLoc) { if (!param) return; ParmVarDecl *Param = cast<ParmVarDecl>(param); Param->setUnparsedDefaultArg(); UnparsedDefaultArgLocs[Param] = ArgLoc; } /// ActOnParamDefaultArgumentError - Parsing or semantic analysis of /// the default argument for the parameter param failed. void Sema::ActOnParamDefaultArgumentError(Decl *param, SourceLocation EqualLoc) { if (!param) return; ParmVarDecl *Param = cast<ParmVarDecl>(param); Param->setInvalidDecl(); UnparsedDefaultArgLocs.erase(Param); Param->setDefaultArg(new(Context) OpaqueValueExpr(EqualLoc, Param->getType().getNonReferenceType(), VK_RValue)); } /// CheckExtraCXXDefaultArguments - Check for any extra default /// arguments in the declarator, which is not a function declaration /// or definition and therefore is not permitted to have default /// arguments. This routine should be invoked for every declarator /// that is not a function declaration or definition. void Sema::CheckExtraCXXDefaultArguments(Declarator &D) { // C++ [dcl.fct.default]p3 // A default argument expression shall be specified only in the // parameter-declaration-clause of a function declaration or in a // template-parameter (14.1). It shall not be specified for a // parameter pack. If it is specified in a // parameter-declaration-clause, it shall not occur within a // declarator or abstract-declarator of a parameter-declaration. bool MightBeFunction = D.isFunctionDeclarationContext(); for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) { DeclaratorChunk &chunk = D.getTypeObject(i); if (chunk.Kind == DeclaratorChunk::Function) { if (MightBeFunction) { // This is a function declaration. It can have default arguments, but // keep looking in case its return type is a function type with default // arguments. MightBeFunction = false; continue; } for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e; ++argIdx) { ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param); if (Param->hasUnparsedDefaultArg()) { CachedTokens *Toks = chunk.Fun.Params[argIdx].DefaultArgTokens; SourceRange SR; if (Toks->size() > 1) SR = SourceRange((*Toks)[1].getLocation(), Toks->back().getLocation()); else SR = UnparsedDefaultArgLocs[Param]; Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc) << SR; delete Toks; chunk.Fun.Params[argIdx].DefaultArgTokens = nullptr; } else if (Param->getDefaultArg()) { Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc) << Param->getDefaultArg()->getSourceRange(); Param->setDefaultArg(nullptr); } } } else if (chunk.Kind != DeclaratorChunk::Paren) { MightBeFunction = false; } } } static bool functionDeclHasDefaultArgument(const FunctionDecl *FD) { for (unsigned NumParams = FD->getNumParams(); NumParams > 0; --NumParams) { const ParmVarDecl *PVD = FD->getParamDecl(NumParams-1); if (!PVD->hasDefaultArg()) return false; if (!PVD->hasInheritedDefaultArg()) return true; } return false; } /// MergeCXXFunctionDecl - Merge two declarations of the same C++ /// function, once we already know that they have the same /// type. Subroutine of MergeFunctionDecl. Returns true if there was an /// error, false otherwise. bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old, Scope *S) { bool Invalid = false; // The declaration context corresponding to the scope is the semantic // parent, unless this is a local function declaration, in which case // it is that surrounding function. DeclContext *ScopeDC = New->isLocalExternDecl() ? New->getLexicalDeclContext() : New->getDeclContext(); // Find the previous declaration for the purpose of default arguments. FunctionDecl *PrevForDefaultArgs = Old; for (/**/; PrevForDefaultArgs; // Don't bother looking back past the latest decl if this is a local // extern declaration; nothing else could work. PrevForDefaultArgs = New->isLocalExternDecl() ? nullptr : PrevForDefaultArgs->getPreviousDecl()) { // Ignore hidden declarations. if (!LookupResult::isVisible(*this, PrevForDefaultArgs)) continue; if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) && !New->isCXXClassMember()) { // Ignore default arguments of old decl if they are not in // the same scope and this is not an out-of-line definition of // a member function. continue; } if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) { // If only one of these is a local function declaration, then they are // declared in different scopes, even though isDeclInScope may think // they're in the same scope. (If both are local, the scope check is // sufficent, and if neither is local, then they are in the same scope.) continue; } // We found our guy. break; } // C++ [dcl.fct.default]p4: // For non-template functions, default arguments can be added in // later declarations of a function in the same // scope. Declarations in different scopes have completely // distinct sets of default arguments. That is, declarations in // inner scopes do not acquire default arguments from // declarations in outer scopes, and vice versa. In a given // function declaration, all parameters subsequent to a // parameter with a default argument shall have default // arguments supplied in this or previous declarations. A // default argument shall not be redefined by a later // declaration (not even to the same value). // // C++ [dcl.fct.default]p6: // Except for member functions of class templates, the default arguments // in a member function definition that appears outside of the class // definition are added to the set of default arguments provided by the // member function declaration in the class definition. for (unsigned p = 0, NumParams = PrevForDefaultArgs ? PrevForDefaultArgs->getNumParams() : 0; p < NumParams; ++p) { ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p); ParmVarDecl *NewParam = New->getParamDecl(p); bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false; bool NewParamHasDfl = NewParam->hasDefaultArg(); if (OldParamHasDfl && NewParamHasDfl) { unsigned DiagDefaultParamID = diag::err_param_default_argument_redefinition; // MSVC accepts that default parameters be redefined for member functions // of template class. The new default parameter's value is ignored. Invalid = true; if (getLangOpts().MicrosoftExt) { CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New); if (MD && MD->getParent()->getDescribedClassTemplate()) { // Merge the old default argument into the new parameter. NewParam->setHasInheritedDefaultArg(); if (OldParam->hasUninstantiatedDefaultArg()) NewParam->setUninstantiatedDefaultArg( OldParam->getUninstantiatedDefaultArg()); else NewParam->setDefaultArg(OldParam->getInit()); DiagDefaultParamID = diag::ext_param_default_argument_redefinition; Invalid = false; } } // FIXME: If we knew where the '=' was, we could easily provide a fix-it // hint here. Alternatively, we could walk the type-source information // for NewParam to find the last source location in the type... but it // isn't worth the effort right now. This is the kind of test case that // is hard to get right: // int f(int); // void g(int (*fp)(int) = f); // void g(int (*fp)(int) = &f); Diag(NewParam->getLocation(), DiagDefaultParamID) << NewParam->getDefaultArgRange(); // Look for the function declaration where the default argument was // actually written, which may be a declaration prior to Old. for (auto Older = PrevForDefaultArgs; OldParam->hasInheritedDefaultArg(); /**/) { Older = Older->getPreviousDecl(); OldParam = Older->getParamDecl(p); } Diag(OldParam->getLocation(), diag::note_previous_definition) << OldParam->getDefaultArgRange(); } else if (OldParamHasDfl) { // Merge the old default argument into the new parameter. // It's important to use getInit() here; getDefaultArg() // strips off any top-level ExprWithCleanups. NewParam->setHasInheritedDefaultArg(); if (OldParam->hasUnparsedDefaultArg()) NewParam->setUnparsedDefaultArg(); else if (OldParam->hasUninstantiatedDefaultArg()) NewParam->setUninstantiatedDefaultArg( OldParam->getUninstantiatedDefaultArg()); else NewParam->setDefaultArg(OldParam->getInit()); } else if (NewParamHasDfl) { if (New->getDescribedFunctionTemplate()) { // Paragraph 4, quoted above, only applies to non-template functions. Diag(NewParam->getLocation(), diag::err_param_default_argument_template_redecl) << NewParam->getDefaultArgRange(); Diag(PrevForDefaultArgs->getLocation(), diag::note_template_prev_declaration) << false; } else if (New->getTemplateSpecializationKind() != TSK_ImplicitInstantiation && New->getTemplateSpecializationKind() != TSK_Undeclared) { // C++ [temp.expr.spec]p21: // Default function arguments shall not be specified in a declaration // or a definition for one of the following explicit specializations: // - the explicit specialization of a function template; // - the explicit specialization of a member function template; // - the explicit specialization of a member function of a class // template where the class template specialization to which the // member function specialization belongs is implicitly // instantiated. Diag(NewParam->getLocation(), diag::err_template_spec_default_arg) << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization) << New->getDeclName() << NewParam->getDefaultArgRange(); } else if (New->getDeclContext()->isDependentContext()) { // C++ [dcl.fct.default]p6 (DR217): // Default arguments for a member function of a class template shall // be specified on the initial declaration of the member function // within the class template. // // Reading the tea leaves a bit in DR217 and its reference to DR205 // leads me to the conclusion that one cannot add default function // arguments for an out-of-line definition of a member function of a // dependent type. int WhichKind = 2; if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(New->getDeclContext())) { if (Record->getDescribedClassTemplate()) WhichKind = 0; else if (isa<ClassTemplatePartialSpecializationDecl>(Record)) WhichKind = 1; else WhichKind = 2; } Diag(NewParam->getLocation(), diag::err_param_default_argument_member_template_redecl) << WhichKind << NewParam->getDefaultArgRange(); } } } // DR1344: If a default argument is added outside a class definition and that // default argument makes the function a special member function, the program // is ill-formed. This can only happen for constructors. if (isa<CXXConstructorDecl>(New) && New->getMinRequiredArguments() < Old->getMinRequiredArguments()) { CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)), OldSM = getSpecialMember(cast<CXXMethodDecl>(Old)); if (NewSM != OldSM) { ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments()); assert(NewParam->hasDefaultArg()); Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special) << NewParam->getDefaultArgRange() << NewSM; Diag(Old->getLocation(), diag::note_previous_declaration); } } const FunctionDecl *Def; // C++11 [dcl.constexpr]p1: If any declaration of a function or function // template has a constexpr specifier then all its declarations shall // contain the constexpr specifier. if (New->isConstexpr() != Old->isConstexpr()) { Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch) << New << New->isConstexpr(); Diag(Old->getLocation(), diag::note_previous_declaration); Invalid = true; } else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() && Old->isDefined(Def)) { // C++11 [dcl.fcn.spec]p4: // If the definition of a function appears in a translation unit before its // first declaration as inline, the program is ill-formed. Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New; Diag(Def->getLocation(), diag::note_previous_definition); Invalid = true; } // C++11 [dcl.fct.default]p4: If a friend declaration specifies a default // argument expression, that declaration shall be a definition and shall be // the only declaration of the function or function template in the // translation unit. if (Old->getFriendObjectKind() == Decl::FOK_Undeclared && functionDeclHasDefaultArgument(Old)) { Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared); Diag(Old->getLocation(), diag::note_previous_declaration); Invalid = true; } if (CheckEquivalentExceptionSpec(Old, New)) Invalid = true; return Invalid; } /// \brief Merge the exception specifications of two variable declarations. /// /// This is called when there's a redeclaration of a VarDecl. The function /// checks if the redeclaration might have an exception specification and /// validates compatibility and merges the specs if necessary. void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) { // Shortcut if exceptions are disabled. if (!getLangOpts().CXXExceptions) return; assert(Context.hasSameType(New->getType(), Old->getType()) && "Should only be called if types are otherwise the same."); QualType NewType = New->getType(); QualType OldType = Old->getType(); // We're only interested in pointers and references to functions, as well // as pointers to member functions. if (const ReferenceType *R = NewType->getAs<ReferenceType>()) { NewType = R->getPointeeType(); OldType = OldType->getAs<ReferenceType>()->getPointeeType(); } else if (const PointerType *P = NewType->getAs<PointerType>()) { NewType = P->getPointeeType(); OldType = OldType->getAs<PointerType>()->getPointeeType(); } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) { NewType = M->getPointeeType(); OldType = OldType->getAs<MemberPointerType>()->getPointeeType(); } if (!NewType->isFunctionProtoType()) return; // There's lots of special cases for functions. For function pointers, system // libraries are hopefully not as broken so that we don't need these // workarounds. if (CheckEquivalentExceptionSpec( OldType->getAs<FunctionProtoType>(), Old->getLocation(), NewType->getAs<FunctionProtoType>(), New->getLocation())) { New->setInvalidDecl(); } } /// CheckCXXDefaultArguments - Verify that the default arguments for a /// function declaration are well-formed according to C++ /// [dcl.fct.default]. void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) { unsigned NumParams = FD->getNumParams(); unsigned p; // Find first parameter with a default argument for (p = 0; p < NumParams; ++p) { ParmVarDecl *Param = FD->getParamDecl(p); if (Param->hasDefaultArg()) break; } // C++11 [dcl.fct.default]p4: // In a given function declaration, each parameter subsequent to a parameter // with a default argument shall have a default argument supplied in this or // a previous declaration or shall be a function parameter pack. A default // argument shall not be redefined by a later declaration (not even to the // same value). unsigned LastMissingDefaultArg = 0; for (; p < NumParams; ++p) { ParmVarDecl *Param = FD->getParamDecl(p); if (!Param->hasDefaultArg() && !Param->isParameterPack()) { if (Param->isInvalidDecl()) /* We already complained about this parameter. */; else if (Param->getIdentifier()) Diag(Param->getLocation(), diag::err_param_default_argument_missing_name) << Param->getIdentifier(); else Diag(Param->getLocation(), diag::err_param_default_argument_missing); LastMissingDefaultArg = p; } } if (LastMissingDefaultArg > 0) { // Some default arguments were missing. Clear out all of the // default arguments up to (and including) the last missing // default argument, so that we leave the function parameters // in a semantically valid state. for (p = 0; p <= LastMissingDefaultArg; ++p) { ParmVarDecl *Param = FD->getParamDecl(p); if (Param->hasDefaultArg()) { Param->setDefaultArg(nullptr); } } } } // CheckConstexprParameterTypes - Check whether a function's parameter types // are all literal types. If so, return true. If not, produce a suitable // diagnostic and return false. static bool CheckConstexprParameterTypes(Sema &SemaRef, const FunctionDecl *FD) { unsigned ArgIndex = 0; const FunctionProtoType *FT = FD->getType()->getAs<FunctionProtoType>(); for (FunctionProtoType::param_type_iterator i = FT->param_type_begin(), e = FT->param_type_end(); i != e; ++i, ++ArgIndex) { const ParmVarDecl *PD = FD->getParamDecl(ArgIndex); SourceLocation ParamLoc = PD->getLocation(); if (!(*i)->isDependentType() && SemaRef.RequireLiteralType(ParamLoc, *i, diag::err_constexpr_non_literal_param, ArgIndex+1, PD->getSourceRange(), isa<CXXConstructorDecl>(FD))) return false; } return true; } /// \brief Get diagnostic %select index for tag kind for /// record diagnostic message. /// WARNING: Indexes apply to particular diagnostics only! /// /// \returns diagnostic %select index. static unsigned getRecordDiagFromTagKind(TagTypeKind Tag) { switch (Tag) { case TTK_Struct: return 0; case TTK_Interface: return 1; case TTK_Class: return 2; default: llvm_unreachable("Invalid tag kind for record diagnostic!"); } } // CheckConstexprFunctionDecl - Check whether a function declaration satisfies // the requirements of a constexpr function definition or a constexpr // constructor definition. If so, return true. If not, produce appropriate // diagnostics and return false. // // This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360. bool Sema::CheckConstexprFunctionDecl(const FunctionDecl *NewFD) { const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD); if (MD && MD->isInstance()) { // C++11 [dcl.constexpr]p4: // The definition of a constexpr constructor shall satisfy the following // constraints: // - the class shall not have any virtual base classes; const CXXRecordDecl *RD = MD->getParent(); if (RD->getNumVBases()) { Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base) << isa<CXXConstructorDecl>(NewFD) << getRecordDiagFromTagKind(RD->getTagKind()) << RD->getNumVBases(); for (const auto &I : RD->vbases()) Diag(I.getLocStart(), diag::note_constexpr_virtual_base_here) << I.getSourceRange(); return false; } } if (!isa<CXXConstructorDecl>(NewFD)) { // C++11 [dcl.constexpr]p3: // The definition of a constexpr function shall satisfy the following // constraints: // - it shall not be virtual; const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD); if (Method && Method->isVirtual()) { Method = Method->getCanonicalDecl(); Diag(Method->getLocation(), diag::err_constexpr_virtual); // If it's not obvious why this function is virtual, find an overridden // function which uses the 'virtual' keyword. const CXXMethodDecl *WrittenVirtual = Method; while (!WrittenVirtual->isVirtualAsWritten()) WrittenVirtual = *WrittenVirtual->begin_overridden_methods(); if (WrittenVirtual != Method) Diag(WrittenVirtual->getLocation(), diag::note_overridden_virtual_function); return false; } // - its return type shall be a literal type; QualType RT = NewFD->getReturnType(); if (!RT->isDependentType() && RequireLiteralType(NewFD->getLocation(), RT, diag::err_constexpr_non_literal_return)) return false; } // - each of its parameter types shall be a literal type; if (!CheckConstexprParameterTypes(*this, NewFD)) return false; return true; } /// Check the given declaration statement is legal within a constexpr function /// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3. /// /// \return true if the body is OK (maybe only as an extension), false if we /// have diagnosed a problem. static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl, DeclStmt *DS, SourceLocation &Cxx1yLoc) { // C++11 [dcl.constexpr]p3 and p4: // The definition of a constexpr function(p3) or constructor(p4) [...] shall // contain only for (const auto *DclIt : DS->decls()) { switch (DclIt->getKind()) { case Decl::StaticAssert: case Decl::Using: case Decl::UsingShadow: case Decl::UsingDirective: case Decl::UnresolvedUsingTypename: case Decl::UnresolvedUsingValue: // - static_assert-declarations // - using-declarations, // - using-directives, continue; case Decl::Typedef: case Decl::TypeAlias: { // - typedef declarations and alias-declarations that do not define // classes or enumerations, const auto *TN = cast<TypedefNameDecl>(DclIt); if (TN->getUnderlyingType()->isVariablyModifiedType()) { // Don't allow variably-modified types in constexpr functions. TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc(); SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla) << TL.getSourceRange() << TL.getType() << isa<CXXConstructorDecl>(Dcl); return false; } continue; } case Decl::Enum: case Decl::CXXRecord: // C++1y allows types to be defined, not just declared. if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition()) SemaRef.Diag(DS->getLocStart(), SemaRef.getLangOpts().CPlusPlus14 ? diag::warn_cxx11_compat_constexpr_type_definition : diag::ext_constexpr_type_definition) << isa<CXXConstructorDecl>(Dcl); continue; case Decl::EnumConstant: case Decl::IndirectField: case Decl::ParmVar: // These can only appear with other declarations which are banned in // C++11 and permitted in C++1y, so ignore them. continue; case Decl::Var: { // C++1y [dcl.constexpr]p3 allows anything except: // a definition of a variable of non-literal type or of static or // thread storage duration or for which no initialization is performed. const auto *VD = cast<VarDecl>(DclIt); if (VD->isThisDeclarationADefinition()) { if (VD->isStaticLocal()) { SemaRef.Diag(VD->getLocation(), diag::err_constexpr_local_var_static) << isa<CXXConstructorDecl>(Dcl) << (VD->getTLSKind() == VarDecl::TLS_Dynamic); return false; } if (!VD->getType()->isDependentType() && SemaRef.RequireLiteralType( VD->getLocation(), VD->getType(), diag::err_constexpr_local_var_non_literal_type, isa<CXXConstructorDecl>(Dcl))) return false; if (!VD->getType()->isDependentType() && !VD->hasInit() && !VD->isCXXForRangeDecl()) { SemaRef.Diag(VD->getLocation(), diag::err_constexpr_local_var_no_init) << isa<CXXConstructorDecl>(Dcl); return false; } } SemaRef.Diag(VD->getLocation(), SemaRef.getLangOpts().CPlusPlus14 ? diag::warn_cxx11_compat_constexpr_local_var : diag::ext_constexpr_local_var) << isa<CXXConstructorDecl>(Dcl); continue; } case Decl::NamespaceAlias: case Decl::Function: // These are disallowed in C++11 and permitted in C++1y. Allow them // everywhere as an extension. if (!Cxx1yLoc.isValid()) Cxx1yLoc = DS->getLocStart(); continue; default: SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_body_invalid_stmt) << isa<CXXConstructorDecl>(Dcl); return false; } } return true; } /// Check that the given field is initialized within a constexpr constructor. /// /// \param Dcl The constexpr constructor being checked. /// \param Field The field being checked. This may be a member of an anonymous /// struct or union nested within the class being checked. /// \param Inits All declarations, including anonymous struct/union members and /// indirect members, for which any initialization was provided. /// \param Diagnosed Set to true if an error is produced. static void CheckConstexprCtorInitializer(Sema &SemaRef, const FunctionDecl *Dcl, FieldDecl *Field, llvm::SmallSet<Decl*, 16> &Inits, bool &Diagnosed) { if (Field->isInvalidDecl()) return; if (Field->isUnnamedBitfield()) return; // Anonymous unions with no variant members and empty anonymous structs do not // need to be explicitly initialized. FIXME: Anonymous structs that contain no // indirect fields don't need initializing. if (Field->isAnonymousStructOrUnion() && (Field->getType()->isUnionType() ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers() : Field->getType()->getAsCXXRecordDecl()->isEmpty())) return; if (!Inits.count(Field)) { if (!Diagnosed) { SemaRef.Diag(Dcl->getLocation(), diag::err_constexpr_ctor_missing_init); Diagnosed = true; } SemaRef.Diag(Field->getLocation(), diag::note_constexpr_ctor_missing_init); } else if (Field->isAnonymousStructOrUnion()) { const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl(); for (auto *I : RD->fields()) // If an anonymous union contains an anonymous struct of which any member // is initialized, all members must be initialized. if (!RD->isUnion() || Inits.count(I)) CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed); } } /// Check the provided statement is allowed in a constexpr function /// definition. static bool CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S, SmallVectorImpl<SourceLocation> &ReturnStmts, SourceLocation &Cxx1yLoc) { // - its function-body shall be [...] a compound-statement that contains only switch (S->getStmtClass()) { case Stmt::NullStmtClass: // - null statements, return true; case Stmt::DeclStmtClass: // - static_assert-declarations // - using-declarations, // - using-directives, // - typedef declarations and alias-declarations that do not define // classes or enumerations, if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc)) return false; return true; case Stmt::ReturnStmtClass: // - and exactly one return statement; if (isa<CXXConstructorDecl>(Dcl)) { // C++1y allows return statements in constexpr constructors. if (!Cxx1yLoc.isValid()) Cxx1yLoc = S->getLocStart(); return true; } ReturnStmts.push_back(S->getLocStart()); return true; case Stmt::CompoundStmtClass: { // C++1y allows compound-statements. if (!Cxx1yLoc.isValid()) Cxx1yLoc = S->getLocStart(); CompoundStmt *CompStmt = cast<CompoundStmt>(S); for (auto *BodyIt : CompStmt->body()) { if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts, Cxx1yLoc)) return false; } return true; } case Stmt::AttributedStmtClass: if (!Cxx1yLoc.isValid()) Cxx1yLoc = S->getLocStart(); return true; case Stmt::IfStmtClass: { // C++1y allows if-statements. if (!Cxx1yLoc.isValid()) Cxx1yLoc = S->getLocStart(); IfStmt *If = cast<IfStmt>(S); if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts, Cxx1yLoc)) return false; if (If->getElse() && !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts, Cxx1yLoc)) return false; return true; } case Stmt::WhileStmtClass: case Stmt::DoStmtClass: case Stmt::ForStmtClass: case Stmt::CXXForRangeStmtClass: case Stmt::ContinueStmtClass: // C++1y allows all of these. We don't allow them as extensions in C++11, // because they don't make sense without variable mutation. if (!SemaRef.getLangOpts().CPlusPlus14) break; if (!Cxx1yLoc.isValid()) Cxx1yLoc = S->getLocStart(); for (Stmt *SubStmt : S->children()) if (SubStmt && !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts, Cxx1yLoc)) return false; return true; case Stmt::SwitchStmtClass: case Stmt::CaseStmtClass: case Stmt::DefaultStmtClass: case Stmt::BreakStmtClass: // C++1y allows switch-statements, and since they don't need variable // mutation, we can reasonably allow them in C++11 as an extension. if (!Cxx1yLoc.isValid()) Cxx1yLoc = S->getLocStart(); for (Stmt *SubStmt : S->children()) if (SubStmt && !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts, Cxx1yLoc)) return false; return true; default: if (!isa<Expr>(S)) break; // C++1y allows expression-statements. if (!Cxx1yLoc.isValid()) Cxx1yLoc = S->getLocStart(); return true; } SemaRef.Diag(S->getLocStart(), diag::err_constexpr_body_invalid_stmt) << isa<CXXConstructorDecl>(Dcl); return false; } /// Check the body for the given constexpr function declaration only contains /// the permitted types of statement. C++11 [dcl.constexpr]p3,p4. /// /// \return true if the body is OK, false if we have diagnosed a problem. bool Sema::CheckConstexprFunctionBody(const FunctionDecl *Dcl, Stmt *Body) { if (isa<CXXTryStmt>(Body)) { // C++11 [dcl.constexpr]p3: // The definition of a constexpr function shall satisfy the following // constraints: [...] // - its function-body shall be = delete, = default, or a // compound-statement // // C++11 [dcl.constexpr]p4: // In the definition of a constexpr constructor, [...] // - its function-body shall not be a function-try-block; Diag(Body->getLocStart(), diag::err_constexpr_function_try_block) << isa<CXXConstructorDecl>(Dcl); return false; } SmallVector<SourceLocation, 4> ReturnStmts; // - its function-body shall be [...] a compound-statement that contains only // [... list of cases ...] CompoundStmt *CompBody = cast<CompoundStmt>(Body); SourceLocation Cxx1yLoc; for (auto *BodyIt : CompBody->body()) { if (!CheckConstexprFunctionStmt(*this, Dcl, BodyIt, ReturnStmts, Cxx1yLoc)) return false; } if (Cxx1yLoc.isValid()) Diag(Cxx1yLoc, getLangOpts().CPlusPlus14 ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt : diag::ext_constexpr_body_invalid_stmt) << isa<CXXConstructorDecl>(Dcl); if (const CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Dcl)) { const CXXRecordDecl *RD = Constructor->getParent(); // DR1359: // - every non-variant non-static data member and base class sub-object // shall be initialized; // DR1460: // - if the class is a union having variant members, exactly one of them // shall be initialized; if (RD->isUnion()) { if (Constructor->getNumCtorInitializers() == 0 && RD->hasVariantMembers()) { Diag(Dcl->getLocation(), diag::err_constexpr_union_ctor_no_init); return false; } } else if (!Constructor->isDependentContext() && !Constructor->isDelegatingConstructor()) { assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases"); // Skip detailed checking if we have enough initializers, and we would // allow at most one initializer per member. bool AnyAnonStructUnionMembers = false; unsigned Fields = 0; for (CXXRecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end(); I != E; ++I, ++Fields) { if (I->isAnonymousStructOrUnion()) { AnyAnonStructUnionMembers = true; break; } } // DR1460: // - if the class is a union-like class, but is not a union, for each of // its anonymous union members having variant members, exactly one of // them shall be initialized; if (AnyAnonStructUnionMembers || Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) { // Check initialization of non-static data members. Base classes are // always initialized so do not need to be checked. Dependent bases // might not have initializers in the member initializer list. llvm::SmallSet<Decl*, 16> Inits; for (const auto *I: Constructor->inits()) { if (FieldDecl *FD = I->getMember()) Inits.insert(FD); else if (IndirectFieldDecl *ID = I->getIndirectMember()) Inits.insert(ID->chain_begin(), ID->chain_end()); } bool Diagnosed = false; for (auto *I : RD->fields()) CheckConstexprCtorInitializer(*this, Dcl, I, Inits, Diagnosed); if (Diagnosed) return false; } } } else { if (ReturnStmts.empty()) { // C++1y doesn't require constexpr functions to contain a 'return' // statement. We still do, unless the return type might be void, because // otherwise if there's no return statement, the function cannot // be used in a core constant expression. bool OK = getLangOpts().CPlusPlus14 && (Dcl->getReturnType()->isVoidType() || Dcl->getReturnType()->isDependentType()); Diag(Dcl->getLocation(), OK ? diag::warn_cxx11_compat_constexpr_body_no_return : diag::err_constexpr_body_no_return); if (!OK) return false; } else if (ReturnStmts.size() > 1) { Diag(ReturnStmts.back(), getLangOpts().CPlusPlus14 ? diag::warn_cxx11_compat_constexpr_body_multiple_return : diag::ext_constexpr_body_multiple_return); for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I) Diag(ReturnStmts[I], diag::note_constexpr_body_previous_return); } } // C++11 [dcl.constexpr]p5: // if no function argument values exist such that the function invocation // substitution would produce a constant expression, the program is // ill-formed; no diagnostic required. // C++11 [dcl.constexpr]p3: // - every constructor call and implicit conversion used in initializing the // return value shall be one of those allowed in a constant expression. // C++11 [dcl.constexpr]p4: // - every constructor involved in initializing non-static data members and // base class sub-objects shall be a constexpr constructor. SmallVector<PartialDiagnosticAt, 8> Diags; if (!Expr::isPotentialConstantExpr(Dcl, Diags)) { Diag(Dcl->getLocation(), diag::ext_constexpr_function_never_constant_expr) << isa<CXXConstructorDecl>(Dcl); for (size_t I = 0, N = Diags.size(); I != N; ++I) Diag(Diags[I].first, Diags[I].second); // Don't return false here: we allow this for compatibility in // system headers. } return true; } /// isCurrentClassName - Determine whether the identifier II is the /// name of the class type currently being defined. In the case of /// nested classes, this will only return true if II is the name of /// the innermost class. bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *, const CXXScopeSpec *SS) { assert(getLangOpts().CPlusPlus && "No class names in C!"); CXXRecordDecl *CurDecl; if (SS && SS->isSet() && !SS->isInvalid()) { DeclContext *DC = computeDeclContext(*SS, true); CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC); } else CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext); if (CurDecl && CurDecl->getIdentifier()) return &II == CurDecl->getIdentifier(); return false; } /// \brief Determine whether the identifier II is a typo for the name of /// the class type currently being defined. If so, update it to the identifier /// that should have been used. bool Sema::isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS) { assert(getLangOpts().CPlusPlus && "No class names in C!"); if (!getLangOpts().SpellChecking) return false; CXXRecordDecl *CurDecl; if (SS && SS->isSet() && !SS->isInvalid()) { DeclContext *DC = computeDeclContext(*SS, true); CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC); } else CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext); if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() && 3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName()) < II->getLength()) { II = CurDecl->getIdentifier(); return true; } return false; } /// \brief Determine whether the given class is a base class of the given /// class, including looking at dependent bases. static bool findCircularInheritance(const CXXRecordDecl *Class, const CXXRecordDecl *Current) { SmallVector<const CXXRecordDecl*, 8> Queue; Class = Class->getCanonicalDecl(); while (true) { for (const auto &I : Current->bases()) { CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl(); if (!Base) continue; Base = Base->getDefinition(); if (!Base) continue; if (Base->getCanonicalDecl() == Class) return true; Queue.push_back(Base); } if (Queue.empty()) return false; Current = Queue.pop_back_val(); } return false; } /// \brief Check the validity of a C++ base class specifier. /// /// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics /// and returns NULL otherwise. CXXBaseSpecifier * Sema::CheckBaseSpecifier(CXXRecordDecl *Class, SourceRange SpecifierRange, bool Virtual, AccessSpecifier Access, TypeSourceInfo *TInfo, SourceLocation EllipsisLoc) { QualType BaseType = TInfo->getType(); // C++ [class.union]p1: // A union shall not have base classes. if (Class->isUnion()) { Diag(Class->getLocation(), diag::err_base_clause_on_union) << SpecifierRange; return nullptr; } if (EllipsisLoc.isValid() && !TInfo->getType()->containsUnexpandedParameterPack()) { Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) << TInfo->getTypeLoc().getSourceRange(); EllipsisLoc = SourceLocation(); } SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc(); if (BaseType->isDependentType()) { // Make sure that we don't have circular inheritance among our dependent // bases. For non-dependent bases, the check for completeness below handles // this. if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) { if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() || ((BaseDecl = BaseDecl->getDefinition()) && findCircularInheritance(Class, BaseDecl))) { Diag(BaseLoc, diag::err_circular_inheritance) << BaseType << Context.getTypeDeclType(Class); if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl()) Diag(BaseDecl->getLocation(), diag::note_previous_decl) << BaseType; return nullptr; } } return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual, Class->getTagKind() == TTK_Class, Access, TInfo, EllipsisLoc); } // Base specifiers must be record types. if (!BaseType->isRecordType()) { Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange; return nullptr; } // C++ [class.union]p1: // A union shall not be used as a base class. if (BaseType->isUnionType()) { Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange; return nullptr; } // For the MS ABI, propagate DLL attributes to base class templates. if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { if (Attr *ClassAttr = getDLLAttr(Class)) { if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>( BaseType->getAsCXXRecordDecl())) { propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate, BaseLoc); } } } // C++ [class.derived]p2: // The class-name in a base-specifier shall not be an incompletely // defined class. if (RequireCompleteType(BaseLoc, BaseType, diag::err_incomplete_base_class, SpecifierRange)) { Class->setInvalidDecl(); return nullptr; } // If the base class is polymorphic or isn't empty, the new one is/isn't, too. RecordDecl *BaseDecl = BaseType->getAs<RecordType>()->getDecl(); assert(BaseDecl && "Record type has no declaration"); BaseDecl = BaseDecl->getDefinition(); assert(BaseDecl && "Base type is not incomplete, but has no definition"); CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl); assert(CXXBaseDecl && "Base type is not a C++ type"); // A class which contains a flexible array member is not suitable for use as a // base class: // - If the layout determines that a base comes before another base, // the flexible array member would index into the subsequent base. // - If the layout determines that base comes before the derived class, // the flexible array member would index into the derived class. if (CXXBaseDecl->hasFlexibleArrayMember()) { Diag(BaseLoc, diag::err_base_class_has_flexible_array_member) << CXXBaseDecl->getDeclName(); return nullptr; } // C++ [class]p3: // If a class is marked final and it appears as a base-type-specifier in // base-clause, the program is ill-formed. if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) { Diag(BaseLoc, diag::err_class_marked_final_used_as_base) << CXXBaseDecl->getDeclName() << FA->isSpelledAsSealed(); Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at) << CXXBaseDecl->getDeclName() << FA->getRange(); return nullptr; } if (BaseDecl->isInvalidDecl()) Class->setInvalidDecl(); // Create the base specifier. return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual, Class->getTagKind() == TTK_Class, Access, TInfo, EllipsisLoc); } /// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is /// one entry in the base class list of a class specifier, for /// example: /// class foo : public bar, virtual private baz { /// 'public bar' and 'virtual private baz' are each base-specifiers. BaseResult Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange, ParsedAttributes &Attributes, bool Virtual, AccessSpecifier Access, ParsedType basetype, SourceLocation BaseLoc, SourceLocation EllipsisLoc) { if (!classdecl) return true; AdjustDeclIfTemplate(classdecl); CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl); if (!Class) return true; // We haven't yet attached the base specifiers. Class->setIsParsingBaseSpecifiers(); // We do not support any C++11 attributes on base-specifiers yet. // Diagnose any attributes we see. if (!Attributes.empty()) { for (AttributeList *Attr = Attributes.getList(); Attr; Attr = Attr->getNext()) { if (Attr->isInvalid() || Attr->getKind() == AttributeList::IgnoredAttribute) continue; Diag(Attr->getLoc(), Attr->getKind() == AttributeList::UnknownAttribute ? diag::warn_unknown_attribute_ignored : diag::err_base_specifier_attribute) << Attr->getName(); } } TypeSourceInfo *TInfo = nullptr; GetTypeFromParser(basetype, &TInfo); if (EllipsisLoc.isInvalid() && DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo, UPPC_BaseType)) return true; if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange, Virtual, Access, TInfo, EllipsisLoc)) return BaseSpec; else Class->setInvalidDecl(); return true; } /// Use small set to collect indirect bases. As this is only used /// locally, there's no need to abstract the small size parameter. typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet; /// \brief Recursively add the bases of Type. Don't add Type itself. static void NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set, const QualType &Type) { // Even though the incoming type is a base, it might not be // a class -- it could be a template parm, for instance. if (auto Rec = Type->getAs<RecordType>()) { auto Decl = Rec->getAsCXXRecordDecl(); // Iterate over its bases. for (const auto &BaseSpec : Decl->bases()) { QualType Base = Context.getCanonicalType(BaseSpec.getType()) .getUnqualifiedType(); if (Set.insert(Base).second) // If we've not already seen it, recurse. NoteIndirectBases(Context, Set, Base); } } } /// \brief Performs the actual work of attaching the given base class /// specifiers to a C++ class. bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class, CXXBaseSpecifier **Bases, unsigned NumBases) { if (NumBases == 0) return false; // Used to keep track of which base types we have already seen, so // that we can properly diagnose redundant direct base types. Note // that the key is always the unqualified canonical type of the base // class. std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes; // Used to track indirect bases so we can see if a direct base is // ambiguous. IndirectBaseSet IndirectBaseTypes; // Copy non-redundant base specifiers into permanent storage. unsigned NumGoodBases = 0; bool Invalid = false; for (unsigned idx = 0; idx < NumBases; ++idx) { QualType NewBaseType = Context.getCanonicalType(Bases[idx]->getType()); NewBaseType = NewBaseType.getLocalUnqualifiedType(); CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType]; if (KnownBase) { // C++ [class.mi]p3: // A class shall not be specified as a direct base class of a // derived class more than once. Diag(Bases[idx]->getLocStart(), diag::err_duplicate_base_class) << KnownBase->getType() << Bases[idx]->getSourceRange(); // Delete the duplicate base class specifier; we're going to // overwrite its pointer later. Context.Deallocate(Bases[idx]); Invalid = true; } else { // Okay, add this new base class. KnownBase = Bases[idx]; Bases[NumGoodBases++] = Bases[idx]; // Note this base's direct & indirect bases, if there could be ambiguity. if (NumBases > 1) NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType); if (const RecordType *Record = NewBaseType->getAs<RecordType>()) { const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl()); if (Class->isInterface() && (!RD->isInterface() || KnownBase->getAccessSpecifier() != AS_public)) { // The Microsoft extension __interface does not permit bases that // are not themselves public interfaces. Diag(KnownBase->getLocStart(), diag::err_invalid_base_in_interface) << getRecordDiagFromTagKind(RD->getTagKind()) << RD->getName() << RD->getSourceRange(); Invalid = true; } if (RD->hasAttr<WeakAttr>()) Class->addAttr(WeakAttr::CreateImplicit(Context)); } } } // Attach the remaining base class specifiers to the derived class. Class->setBases(Bases, NumGoodBases); for (unsigned idx = 0; idx < NumGoodBases; ++idx) { // Check whether this direct base is inaccessible due to ambiguity. QualType BaseType = Bases[idx]->getType(); CanQualType CanonicalBase = Context.getCanonicalType(BaseType) .getUnqualifiedType(); if (IndirectBaseTypes.count(CanonicalBase)) { CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, /*DetectVirtual=*/true); bool found = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths); assert(found); (void)found; if (Paths.isAmbiguous(CanonicalBase)) Diag(Bases[idx]->getLocStart (), diag::warn_inaccessible_base_class) << BaseType << getAmbiguousPathsDisplayString(Paths) << Bases[idx]->getSourceRange(); else assert(Bases[idx]->isVirtual()); } // Delete the base class specifier, since its data has been copied // into the CXXRecordDecl. Context.Deallocate(Bases[idx]); } return Invalid; } /// ActOnBaseSpecifiers - Attach the given base specifiers to the /// class, after checking whether there are any duplicate base /// classes. void Sema::ActOnBaseSpecifiers(Decl *ClassDecl, CXXBaseSpecifier **Bases, unsigned NumBases) { if (!ClassDecl || !Bases || !NumBases) return; AdjustDeclIfTemplate(ClassDecl); AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases, NumBases); } /// \brief Determine whether the type \p Derived is a C++ class that is /// derived from the type \p Base. bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base) { if (!getLangOpts().CPlusPlus) return false; CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl(); if (!DerivedRD) return false; CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl(); if (!BaseRD) return false; // If either the base or the derived type is invalid, don't try to // check whether one is derived from the other. if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl()) return false; // FIXME: In a modules build, do we need the entire path to be visible for us // to be able to use the inheritance relationship? if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined()) return false; return DerivedRD->isDerivedFrom(BaseRD); } /// \brief Determine whether the type \p Derived is a C++ class that is /// derived from the type \p Base. bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base, CXXBasePaths &Paths) { if (!getLangOpts().CPlusPlus) return false; CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl(); if (!DerivedRD) return false; CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl(); if (!BaseRD) return false; if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined()) return false; return DerivedRD->isDerivedFrom(BaseRD, Paths); } void Sema::BuildBasePathArray(const CXXBasePaths &Paths, CXXCastPath &BasePathArray) { assert(BasePathArray.empty() && "Base path array must be empty!"); assert(Paths.isRecordingPaths() && "Must record paths!"); const CXXBasePath &Path = Paths.front(); // We first go backward and check if we have a virtual base. // FIXME: It would be better if CXXBasePath had the base specifier for // the nearest virtual base. unsigned Start = 0; for (unsigned I = Path.size(); I != 0; --I) { if (Path[I - 1].Base->isVirtual()) { Start = I - 1; break; } } // Now add all bases. for (unsigned I = Start, E = Path.size(); I != E; ++I) BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base)); } /// CheckDerivedToBaseConversion - Check whether the Derived-to-Base /// conversion (where Derived and Base are class types) is /// well-formed, meaning that the conversion is unambiguous (and /// that all of the base classes are accessible). Returns true /// and emits a diagnostic if the code is ill-formed, returns false /// otherwise. Loc is the location where this routine should point to /// if there is an error, and Range is the source range to highlight /// if there is an error. bool Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base, unsigned InaccessibleBaseID, unsigned AmbigiousBaseConvID, SourceLocation Loc, SourceRange Range, DeclarationName Name, CXXCastPath *BasePath) { // First, determine whether the path from Derived to Base is // ambiguous. This is slightly more expensive than checking whether // the Derived to Base conversion exists, because here we need to // explore multiple paths to determine if there is an ambiguity. CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, /*DetectVirtual=*/false); bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths); assert(DerivationOkay && "Can only be used with a derived-to-base conversion"); (void)DerivationOkay; if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType())) { if (InaccessibleBaseID) { // Check that the base class can be accessed. switch (CheckBaseClassAccess(Loc, Base, Derived, Paths.front(), InaccessibleBaseID)) { case AR_inaccessible: return true; case AR_accessible: case AR_dependent: case AR_delayed: break; } } // Build a base path if necessary. if (BasePath) BuildBasePathArray(Paths, *BasePath); return false; } if (AmbigiousBaseConvID) { // We know that the derived-to-base conversion is ambiguous, and // we're going to produce a diagnostic. Perform the derived-to-base // search just one more time to compute all of the possible paths so // that we can print them out. This is more expensive than any of // the previous derived-to-base checks we've done, but at this point // performance isn't as much of an issue. Paths.clear(); Paths.setRecordingPaths(true); bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths); assert(StillOkay && "Can only be used with a derived-to-base conversion"); (void)StillOkay; // Build up a textual representation of the ambiguous paths, e.g., // D -> B -> A, that will be used to illustrate the ambiguous // conversions in the diagnostic. We only print one of the paths // to each base class subobject. std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); Diag(Loc, AmbigiousBaseConvID) << Derived << Base << PathDisplayStr << Range << Name; } return true; } bool Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base, SourceLocation Loc, SourceRange Range, CXXCastPath *BasePath, bool IgnoreAccess) { return CheckDerivedToBaseConversion(Derived, Base, IgnoreAccess ? 0 : diag::err_upcast_to_inaccessible_base, diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(), BasePath); } /// @brief Builds a string representing ambiguous paths from a /// specific derived class to different subobjects of the same base /// class. /// /// This function builds a string that can be used in error messages /// to show the different paths that one can take through the /// inheritance hierarchy to go from the derived class to different /// subobjects of a base class. The result looks something like this: /// @code /// struct D -> struct B -> struct A /// struct D -> struct C -> struct A /// @endcode std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) { std::string PathDisplayStr; std::set<unsigned> DisplayedPaths; for (CXXBasePaths::paths_iterator Path = Paths.begin(); Path != Paths.end(); ++Path) { if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) { // We haven't displayed a path to this particular base // class subobject yet. PathDisplayStr += "\n "; PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString(); for (CXXBasePath::const_iterator Element = Path->begin(); Element != Path->end(); ++Element) PathDisplayStr += " -> " + Element->Base->getType().getAsString(); } } return PathDisplayStr; } //===----------------------------------------------------------------------===// // C++ class member Handling //===----------------------------------------------------------------------===// /// ActOnAccessSpecifier - Parsed an access specifier followed by a colon. bool Sema::ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc, SourceLocation ColonLoc, AttributeList *Attrs) { assert(Access != AS_none && "Invalid kind for syntactic access specifier!"); AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext, ASLoc, ColonLoc); CurContext->addHiddenDecl(ASDecl); return ProcessAccessDeclAttributeList(ASDecl, Attrs); } /// CheckOverrideControl - Check C++11 override control semantics. void Sema::CheckOverrideControl(NamedDecl *D) { if (D->isInvalidDecl()) return; // We only care about "override" and "final" declarations. if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>()) return; CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D); // We can't check dependent instance methods. if (MD && MD->isInstance() && (MD->getParent()->hasAnyDependentBases() || MD->getType()->isDependentType())) return; if (MD && !MD->isVirtual()) { // If we have a non-virtual method, check if if hides a virtual method. // (In that case, it's most likely the method has the wrong type.) SmallVector<CXXMethodDecl *, 8> OverloadedMethods; FindHiddenVirtualMethods(MD, OverloadedMethods); if (!OverloadedMethods.empty()) { if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) { Diag(OA->getLocation(), diag::override_keyword_hides_virtual_member_function) << "override" << (OverloadedMethods.size() > 1); } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) { Diag(FA->getLocation(), diag::override_keyword_hides_virtual_member_function) << (FA->isSpelledAsSealed() ? "sealed" : "final") << (OverloadedMethods.size() > 1); } NoteHiddenVirtualMethods(MD, OverloadedMethods); MD->setInvalidDecl(); return; } // Fall through into the general case diagnostic. // FIXME: We might want to attempt typo correction here. } if (!MD || !MD->isVirtual()) { if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) { Diag(OA->getLocation(), diag::override_keyword_only_allowed_on_virtual_member_functions) << "override" << FixItHint::CreateRemoval(OA->getLocation()); D->dropAttr<OverrideAttr>(); } if (FinalAttr *FA = D->getAttr<FinalAttr>()) { Diag(FA->getLocation(), diag::override_keyword_only_allowed_on_virtual_member_functions) << (FA->isSpelledAsSealed() ? "sealed" : "final") << FixItHint::CreateRemoval(FA->getLocation()); D->dropAttr<FinalAttr>(); } return; } // C++11 [class.virtual]p5: // If a function is marked with the virt-specifier override and // does not override a member function of a base class, the program is // ill-formed. bool HasOverriddenMethods = MD->begin_overridden_methods() != MD->end_overridden_methods(); if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods) Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding) << MD->getDeclName(); } void Sema::DiagnoseAbsenceOfOverrideControl(NamedDecl *D) { if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>()) return; CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D); if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>() || isa<CXXDestructorDecl>(MD)) return; SourceLocation Loc = MD->getLocation(); SourceLocation SpellingLoc = Loc; if (getSourceManager().isMacroArgExpansion(Loc)) SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).first; SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc); if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc)) return; if (MD->size_overridden_methods() > 0) { Diag(MD->getLocation(), diag::warn_function_marked_not_override_overriding) << MD->getDeclName(); const CXXMethodDecl *OMD = *MD->begin_overridden_methods(); Diag(OMD->getLocation(), diag::note_overridden_virtual_function); } } /// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member /// function overrides a virtual member function marked 'final', according to /// C++11 [class.virtual]p4. bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New, const CXXMethodDecl *Old) { FinalAttr *FA = Old->getAttr<FinalAttr>(); if (!FA) return false; Diag(New->getLocation(), diag::err_final_function_overridden) << New->getDeclName() << FA->isSpelledAsSealed(); Diag(Old->getLocation(), diag::note_overridden_virtual_function); return true; } static bool InitializationHasSideEffects(const FieldDecl &FD) { const Type *T = FD.getType()->getBaseElementTypeUnsafe(); // FIXME: Destruction of ObjC lifetime types has side-effects. if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) return !RD->isCompleteDefinition() || !RD->hasTrivialDefaultConstructor() || !RD->hasTrivialDestructor(); return false; } static AttributeList *getMSPropertyAttr(AttributeList *list) { for (AttributeList *it = list; it != nullptr; it = it->getNext()) if (it->isDeclspecPropertyAttribute()) return it; return nullptr; } /// ActOnCXXMemberDeclarator - This is invoked when a C++ class member /// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the /// bitfield width if there is one, 'InitExpr' specifies the initializer if /// one has been parsed, and 'InitStyle' is set if an in-class initializer is /// present (but parsing it has been deferred). NamedDecl * Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D, MultiTemplateParamsArg TemplateParameterLists, Expr *BW, const VirtSpecifiers &VS, InClassInitStyle InitStyle) { const DeclSpec &DS = D.getDeclSpec(); DeclarationNameInfo NameInfo = GetNameForDeclarator(D); DeclarationName Name = NameInfo.getName(); SourceLocation Loc = NameInfo.getLoc(); // For anonymous bitfields, the location should point to the type. if (Loc.isInvalid()) Loc = D.getLocStart(); Expr *BitWidth = static_cast<Expr*>(BW); assert(isa<CXXRecordDecl>(CurContext)); assert(!DS.isFriendSpecified()); bool isFunc = D.isDeclarationOfFunction(); if (cast<CXXRecordDecl>(CurContext)->isInterface()) { // The Microsoft extension __interface only permits public member functions // and prohibits constructors, destructors, operators, non-public member // functions, static methods and data members. unsigned InvalidDecl; bool ShowDeclName = true; if (!isFunc) InvalidDecl = (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) ? 0 : 1; else if (AS != AS_public) InvalidDecl = 2; else if (DS.getStorageClassSpec() == DeclSpec::SCS_static) InvalidDecl = 3; else switch (Name.getNameKind()) { case DeclarationName::CXXConstructorName: InvalidDecl = 4; ShowDeclName = false; break; case DeclarationName::CXXDestructorName: InvalidDecl = 5; ShowDeclName = false; break; case DeclarationName::CXXOperatorName: case DeclarationName::CXXConversionFunctionName: InvalidDecl = 6; break; default: InvalidDecl = 0; break; } if (InvalidDecl) { if (ShowDeclName) Diag(Loc, diag::err_invalid_member_in_interface) << (InvalidDecl-1) << Name; else Diag(Loc, diag::err_invalid_member_in_interface) << (InvalidDecl-1) << ""; return nullptr; } } // C++ 9.2p6: A member shall not be declared to have automatic storage // duration (auto, register) or with the extern storage-class-specifier. // C++ 7.1.1p8: The mutable specifier can be applied only to names of class // data members and cannot be applied to names declared const or static, // and cannot be applied to reference members. switch (DS.getStorageClassSpec()) { case DeclSpec::SCS_unspecified: case DeclSpec::SCS_typedef: case DeclSpec::SCS_static: break; case DeclSpec::SCS_mutable: if (isFunc) { Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function); // FIXME: It would be nicer if the keyword was ignored only for this // declarator. Otherwise we could get follow-up errors. D.getMutableDeclSpec().ClearStorageClassSpecs(); } break; default: Diag(DS.getStorageClassSpecLoc(), diag::err_storageclass_invalid_for_member); D.getMutableDeclSpec().ClearStorageClassSpecs(); break; } bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified || DS.getStorageClassSpec() == DeclSpec::SCS_mutable) && !isFunc); if (DS.isConstexprSpecified() && isInstField) { SemaDiagnosticBuilder B = Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member); SourceLocation ConstexprLoc = DS.getConstexprSpecLoc(); if (InitStyle == ICIS_NoInit) { B << 0 << 0; if (D.getDeclSpec().getTypeQualifiers() & DeclSpec::TQ_const) B << FixItHint::CreateRemoval(ConstexprLoc); else { B << FixItHint::CreateReplacement(ConstexprLoc, "const"); D.getMutableDeclSpec().ClearConstexprSpec(); const char *PrevSpec; unsigned DiagID; bool Failed = D.getMutableDeclSpec().SetTypeQual( DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts()); (void)Failed; assert(!Failed && "Making a constexpr member const shouldn't fail"); } } else { B << 1; const char *PrevSpec; unsigned DiagID; if (D.getMutableDeclSpec().SetStorageClassSpec( *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID, Context.getPrintingPolicy())) { assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable && "This is the only DeclSpec that should fail to be applied"); B << 1; } else { B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static "); isInstField = false; } } } NamedDecl *Member; if (isInstField) { CXXScopeSpec &SS = D.getCXXScopeSpec(); // Data members must have identifiers for names. if (!Name.isIdentifier()) { Diag(Loc, diag::err_bad_variable_name) << Name; return nullptr; } IdentifierInfo *II = Name.getAsIdentifierInfo(); // Member field could not be with "template" keyword. // So TemplateParameterLists should be empty in this case. if (TemplateParameterLists.size()) { TemplateParameterList* TemplateParams = TemplateParameterLists[0]; if (TemplateParams->size()) { // There is no such thing as a member field template. Diag(D.getIdentifierLoc(), diag::err_template_member) << II << SourceRange(TemplateParams->getTemplateLoc(), TemplateParams->getRAngleLoc()); } else { // There is an extraneous 'template<>' for this member. Diag(TemplateParams->getTemplateLoc(), diag::err_template_member_noparams) << II << SourceRange(TemplateParams->getTemplateLoc(), TemplateParams->getRAngleLoc()); } return nullptr; } if (SS.isSet() && !SS.isInvalid()) { // The user provided a superfluous scope specifier inside a class // definition: // // class X { // int X::member; // }; if (DeclContext *DC = computeDeclContext(SS, false)) diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc()); else Diag(D.getIdentifierLoc(), diag::err_member_qualification) << Name << SS.getRange(); SS.clear(); } AttributeList *MSPropertyAttr = getMSPropertyAttr(D.getDeclSpec().getAttributes().getList()); if (MSPropertyAttr) { Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D, BitWidth, InitStyle, AS, MSPropertyAttr); if (!Member) return nullptr; isInstField = false; } else { Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D, BitWidth, InitStyle, AS); assert(Member && "HandleField never returns null"); } } else { Member = HandleDeclarator(S, D, TemplateParameterLists); if (!Member) return nullptr; // Non-instance-fields can't have a bitfield. if (BitWidth) { if (Member->isInvalidDecl()) { // don't emit another diagnostic. } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) { // C++ 9.6p3: A bit-field shall not be a static member. // "static member 'A' cannot be a bit-field" Diag(Loc, diag::err_static_not_bitfield) << Name << BitWidth->getSourceRange(); } else if (isa<TypedefDecl>(Member)) { // "typedef member 'x' cannot be a bit-field" Diag(Loc, diag::err_typedef_not_bitfield) << Name << BitWidth->getSourceRange(); } else { // A function typedef ("typedef int f(); f a;"). // C++ 9.6p3: A bit-field shall have integral or enumeration type. Diag(Loc, diag::err_not_integral_type_bitfield) << Name << cast<ValueDecl>(Member)->getType() << BitWidth->getSourceRange(); } BitWidth = nullptr; Member->setInvalidDecl(); } Member->setAccess(AS); // If we have declared a member function template or static data member // template, set the access of the templated declaration as well. if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member)) FunTmpl->getTemplatedDecl()->setAccess(AS); else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member)) VarTmpl->getTemplatedDecl()->setAccess(AS); } if (VS.isOverrideSpecified()) Member->addAttr(new (Context) OverrideAttr(VS.getOverrideLoc(), Context, 0)); if (VS.isFinalSpecified()) Member->addAttr(new (Context) FinalAttr(VS.getFinalLoc(), Context, VS.isFinalSpelledSealed())); if (VS.getLastLocation().isValid()) { // Update the end location of a method that has a virt-specifiers. if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member)) MD->setRangeEnd(VS.getLastLocation()); } CheckOverrideControl(Member); assert((Name || isInstField) && "No identifier for non-field ?"); if (isInstField) { FieldDecl *FD = cast<FieldDecl>(Member); FieldCollector->Add(FD); if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) { // Remember all explicit private FieldDecls that have a name, no side // effects and are not part of a dependent type declaration. if (!FD->isImplicit() && FD->getDeclName() && FD->getAccess() == AS_private && !FD->hasAttr<UnusedAttr>() && !FD->getParent()->isDependentContext() && !InitializationHasSideEffects(*FD)) UnusedPrivateFields.insert(FD); } } return Member; } namespace { class UninitializedFieldVisitor : public EvaluatedExprVisitor<UninitializedFieldVisitor> { Sema &S; // List of Decls to generate a warning on. Also remove Decls that become // initialized. llvm::SmallPtrSetImpl<ValueDecl*> &Decls; // List of base classes of the record. Classes are removed after their // initializers. llvm::SmallPtrSetImpl<QualType> &BaseClasses; // Vector of decls to be removed from the Decl set prior to visiting the // nodes. These Decls may have been initialized in the prior initializer. llvm::SmallVector<ValueDecl*, 4> DeclsToRemove; // If non-null, add a note to the warning pointing back to the constructor. const CXXConstructorDecl *Constructor; // Variables to hold state when processing an initializer list. When // InitList is true, special case initialization of FieldDecls matching // InitListFieldDecl. bool InitList; FieldDecl *InitListFieldDecl; llvm::SmallVector<unsigned, 4> InitFieldIndex; public: typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited; UninitializedFieldVisitor(Sema &S, llvm::SmallPtrSetImpl<ValueDecl*> &Decls, llvm::SmallPtrSetImpl<QualType> &BaseClasses) : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses), Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {} // Returns true if the use of ME is not an uninitialized use. bool IsInitListMemberExprInitialized(MemberExpr *ME, bool CheckReferenceOnly) { llvm::SmallVector<FieldDecl*, 4> Fields; bool ReferenceField = false; while (ME) { FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()); if (!FD) return false; Fields.push_back(FD); if (FD->getType()->isReferenceType()) ReferenceField = true; ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts()); } // Binding a reference to an unintialized field is not an // uninitialized use. if (CheckReferenceOnly && !ReferenceField) return true; llvm::SmallVector<unsigned, 4> UsedFieldIndex; // Discard the first field since it is the field decl that is being // initialized. for (auto I = Fields.rbegin() + 1, E = Fields.rend(); I != E; ++I) { UsedFieldIndex.push_back((*I)->getFieldIndex()); } for (auto UsedIter = UsedFieldIndex.begin(), UsedEnd = UsedFieldIndex.end(), OrigIter = InitFieldIndex.begin(), OrigEnd = InitFieldIndex.end(); UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) { if (*UsedIter < *OrigIter) return true; if (*UsedIter > *OrigIter) break; } return false; } void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly, bool AddressOf) { if (isa<EnumConstantDecl>(ME->getMemberDecl())) return; // FieldME is the inner-most MemberExpr that is not an anonymous struct // or union. MemberExpr *FieldME = ME; bool AllPODFields = FieldME->getType().isPODType(S.Context); Expr *Base = ME; while (MemberExpr *SubME = dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) { if (isa<VarDecl>(SubME->getMemberDecl())) return; if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl())) if (!FD->isAnonymousStructOrUnion()) FieldME = SubME; if (!FieldME->getType().isPODType(S.Context)) AllPODFields = false; Base = SubME->getBase(); } if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts())) return; if (AddressOf && AllPODFields) return; ValueDecl* FoundVD = FieldME->getMemberDecl(); if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) { while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) { BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr()); } if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) { QualType T = BaseCast->getType(); if (T->isPointerType() && BaseClasses.count(T->getPointeeType())) { S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit) << T->getPointeeType() << FoundVD; } } } if (!Decls.count(FoundVD)) return; const bool IsReference = FoundVD->getType()->isReferenceType(); if (InitList && !AddressOf && FoundVD == InitListFieldDecl) { // Special checking for initializer lists. if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) { return; } } else { // Prevent double warnings on use of unbounded references. if (CheckReferenceOnly && !IsReference) return; } unsigned diag = IsReference ? diag::warn_reference_field_is_uninit : diag::warn_field_is_uninit; S.Diag(FieldME->getExprLoc(), diag) << FoundVD; if (Constructor) S.Diag(Constructor->getLocation(), diag::note_uninit_in_this_constructor) << (Constructor->isDefaultConstructor() && Constructor->isImplicit()); } void HandleValue(Expr *E, bool AddressOf) { E = E->IgnoreParens(); if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) { HandleMemberExpr(ME, false /*CheckReferenceOnly*/, AddressOf /*AddressOf*/); return; } if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) { Visit(CO->getCond()); HandleValue(CO->getTrueExpr(), AddressOf); HandleValue(CO->getFalseExpr(), AddressOf); return; } if (BinaryConditionalOperator *BCO = dyn_cast<BinaryConditionalOperator>(E)) { Visit(BCO->getCond()); HandleValue(BCO->getFalseExpr(), AddressOf); return; } if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) { HandleValue(OVE->getSourceExpr(), AddressOf); return; } if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { switch (BO->getOpcode()) { default: break; case(BO_PtrMemD): case(BO_PtrMemI): HandleValue(BO->getLHS(), AddressOf); Visit(BO->getRHS()); return; case(BO_Comma): Visit(BO->getLHS()); HandleValue(BO->getRHS(), AddressOf); return; } } Visit(E); } void CheckInitListExpr(InitListExpr *ILE) { InitFieldIndex.push_back(0); for (auto Child : ILE->children()) { if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) { CheckInitListExpr(SubList); } else { Visit(Child); } ++InitFieldIndex.back(); } InitFieldIndex.pop_back(); } void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor, FieldDecl *Field, const Type *BaseClass) { // Remove Decls that may have been initialized in the previous // initializer. for (ValueDecl* VD : DeclsToRemove) Decls.erase(VD); DeclsToRemove.clear(); Constructor = FieldConstructor; InitListExpr *ILE = dyn_cast<InitListExpr>(E); if (ILE && Field) { InitList = true; InitListFieldDecl = Field; InitFieldIndex.clear(); CheckInitListExpr(ILE); } else { InitList = false; Visit(E); } if (Field) Decls.erase(Field); if (BaseClass) BaseClasses.erase(BaseClass->getCanonicalTypeInternal()); } void VisitMemberExpr(MemberExpr *ME) { // All uses of unbounded reference fields will warn. HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/); } void VisitImplicitCastExpr(ImplicitCastExpr *E) { if (E->getCastKind() == CK_LValueToRValue) { HandleValue(E->getSubExpr(), false /*AddressOf*/); return; } Inherited::VisitImplicitCastExpr(E); } void VisitCXXConstructExpr(CXXConstructExpr *E) { if (E->getConstructor()->isCopyConstructor()) { Expr *ArgExpr = E->getArg(0); if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr)) if (ILE->getNumInits() == 1) ArgExpr = ILE->getInit(0); if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr)) if (ICE->getCastKind() == CK_NoOp) ArgExpr = ICE->getSubExpr(); HandleValue(ArgExpr, false /*AddressOf*/); return; } Inherited::VisitCXXConstructExpr(E); } void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) { Expr *Callee = E->getCallee(); if (isa<MemberExpr>(Callee)) { HandleValue(Callee, false /*AddressOf*/); for (auto Arg : E->arguments()) Visit(Arg); return; } Inherited::VisitCXXMemberCallExpr(E); } void VisitCallExpr(CallExpr *E) { // Treat std::move as a use. if (E->getNumArgs() == 1) { if (FunctionDecl *FD = E->getDirectCallee()) { if (FD->isInStdNamespace() && FD->getIdentifier() && FD->getIdentifier()->isStr("move")) { HandleValue(E->getArg(0), false /*AddressOf*/); return; } } } Inherited::VisitCallExpr(E); } void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) { Expr *Callee = E->getCallee(); if (isa<UnresolvedLookupExpr>(Callee)) return Inherited::VisitCXXOperatorCallExpr(E); Visit(Callee); for (auto Arg : E->arguments()) HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/); } void VisitBinaryOperator(BinaryOperator *E) { // If a field assignment is detected, remove the field from the // uninitiailized field set. if (E->getOpcode() == BO_Assign) if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS())) if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) if (!FD->getType()->isReferenceType()) DeclsToRemove.push_back(FD); if (E->isCompoundAssignmentOp()) { HandleValue(E->getLHS(), false /*AddressOf*/); Visit(E->getRHS()); return; } Inherited::VisitBinaryOperator(E); } void VisitUnaryOperator(UnaryOperator *E) { if (E->isIncrementDecrementOp()) { HandleValue(E->getSubExpr(), false /*AddressOf*/); return; } if (E->getOpcode() == UO_AddrOf) { if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) { HandleValue(ME->getBase(), true /*AddressOf*/); return; } } Inherited::VisitUnaryOperator(E); } }; // Diagnose value-uses of fields to initialize themselves, e.g. // foo(foo) // where foo is not also a parameter to the constructor. // Also diagnose across field uninitialized use such as // x(y), y(x) // TODO: implement -Wuninitialized and fold this into that framework. static void DiagnoseUninitializedFields( Sema &SemaRef, const CXXConstructorDecl *Constructor) { if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit, Constructor->getLocation())) { return; } if (Constructor->isInvalidDecl()) return; const CXXRecordDecl *RD = Constructor->getParent(); if (RD->getDescribedClassTemplate()) return; // Holds fields that are uninitialized. llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields; // At the beginning, all fields are uninitialized. for (auto *I : RD->decls()) { if (auto *FD = dyn_cast<FieldDecl>(I)) { UninitializedFields.insert(FD); } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) { UninitializedFields.insert(IFD->getAnonField()); } } llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses; for (auto I : RD->bases()) UninitializedBaseClasses.insert(I.getType().getCanonicalType()); if (UninitializedFields.empty() && UninitializedBaseClasses.empty()) return; UninitializedFieldVisitor UninitializedChecker(SemaRef, UninitializedFields, UninitializedBaseClasses); for (const auto *FieldInit : Constructor->inits()) { if (UninitializedFields.empty() && UninitializedBaseClasses.empty()) break; Expr *InitExpr = FieldInit->getInit(); if (!InitExpr) continue; if (CXXDefaultInitExpr *Default = dyn_cast<CXXDefaultInitExpr>(InitExpr)) { InitExpr = Default->getExpr(); if (!InitExpr) continue; // In class initializers will point to the constructor. UninitializedChecker.CheckInitializer(InitExpr, Constructor, FieldInit->getAnyMember(), FieldInit->getBaseClass()); } else { UninitializedChecker.CheckInitializer(InitExpr, nullptr, FieldInit->getAnyMember(), FieldInit->getBaseClass()); } } } } // namespace /// \brief Enter a new C++ default initializer scope. After calling this, the /// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if /// parsing or instantiating the initializer failed. void Sema::ActOnStartCXXInClassMemberInitializer() { // Create a synthetic function scope to represent the call to the constructor // that notionally surrounds a use of this initializer. PushFunctionScope(); } /// \brief This is invoked after parsing an in-class initializer for a /// non-static C++ class member, and after instantiating an in-class initializer /// in a class template. Such actions are deferred until the class is complete. void Sema::ActOnFinishCXXInClassMemberInitializer(Decl *D, SourceLocation InitLoc, Expr *InitExpr) { // Pop the notional constructor scope we created earlier. PopFunctionScopeInfo(nullptr, D); FieldDecl *FD = dyn_cast<FieldDecl>(D); assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) && "must set init style when field is created"); if (!InitExpr) { D->setInvalidDecl(); if (FD) FD->removeInClassInitializer(); return; } if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) { FD->setInvalidDecl(); FD->removeInClassInitializer(); return; } ExprResult Init = InitExpr; if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) { InitializedEntity Entity = InitializedEntity::InitializeMember(FD); InitializationKind Kind = FD->getInClassInitStyle() == ICIS_ListInit ? InitializationKind::CreateDirectList(InitExpr->getLocStart()) : InitializationKind::CreateCopy(InitExpr->getLocStart(), InitLoc); InitializationSequence Seq(*this, Entity, Kind, InitExpr); Init = Seq.Perform(*this, Entity, Kind, InitExpr); if (Init.isInvalid()) { FD->setInvalidDecl(); return; } } // C++11 [class.base.init]p7: // The initialization of each base and member constitutes a // full-expression. Init = ActOnFinishFullExpr(Init.get(), InitLoc); if (Init.isInvalid()) { FD->setInvalidDecl(); return; } InitExpr = Init.get(); FD->setInClassInitializer(InitExpr); } /// \brief Find the direct and/or virtual base specifiers that /// correspond to the given base type, for use in base initialization /// within a constructor. static bool FindBaseInitializer(Sema &SemaRef, CXXRecordDecl *ClassDecl, QualType BaseType, const CXXBaseSpecifier *&DirectBaseSpec, const CXXBaseSpecifier *&VirtualBaseSpec) { // First, check for a direct base class. DirectBaseSpec = nullptr; for (const auto &Base : ClassDecl->bases()) { if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) { // We found a direct base of this type. That's what we're // initializing. DirectBaseSpec = &Base; break; } } // Check for a virtual base class. // FIXME: We might be able to short-circuit this if we know in advance that // there are no virtual bases. VirtualBaseSpec = nullptr; if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) { // We haven't found a base yet; search the class hierarchy for a // virtual base class. CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, /*DetectVirtual=*/false); if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(), SemaRef.Context.getTypeDeclType(ClassDecl), BaseType, Paths)) { for (CXXBasePaths::paths_iterator Path = Paths.begin(); Path != Paths.end(); ++Path) { if (Path->back().Base->isVirtual()) { VirtualBaseSpec = Path->back().Base; break; } } } } return DirectBaseSpec || VirtualBaseSpec; } /// \brief Handle a C++ member initializer using braced-init-list syntax. MemInitResult Sema::ActOnMemInitializer(Decl *ConstructorD, Scope *S, CXXScopeSpec &SS, IdentifierInfo *MemberOrBase, ParsedType TemplateTypeTy, const DeclSpec &DS, SourceLocation IdLoc, Expr *InitList, SourceLocation EllipsisLoc) { return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy, DS, IdLoc, InitList, EllipsisLoc); } /// \brief Handle a C++ member initializer using parentheses syntax. MemInitResult Sema::ActOnMemInitializer(Decl *ConstructorD, Scope *S, CXXScopeSpec &SS, IdentifierInfo *MemberOrBase, ParsedType TemplateTypeTy, const DeclSpec &DS, SourceLocation IdLoc, SourceLocation LParenLoc, ArrayRef<Expr *> Args, SourceLocation RParenLoc, SourceLocation EllipsisLoc) { Expr *List = new (Context) ParenListExpr(Context, LParenLoc, Args, RParenLoc); return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy, DS, IdLoc, List, EllipsisLoc); } namespace { // Callback to only accept typo corrections that can be a valid C++ member // intializer: either a non-static field member or a base class. class MemInitializerValidatorCCC : public CorrectionCandidateCallback { public: explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl) : ClassDecl(ClassDecl) {} bool ValidateCandidate(const TypoCorrection &candidate) override { if (NamedDecl *ND = candidate.getCorrectionDecl()) { if (FieldDecl *Member = dyn_cast<FieldDecl>(ND)) return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl); return isa<TypeDecl>(ND); } return false; } private: CXXRecordDecl *ClassDecl; }; } /// \brief Handle a C++ member initializer. MemInitResult Sema::BuildMemInitializer(Decl *ConstructorD, Scope *S, CXXScopeSpec &SS, IdentifierInfo *MemberOrBase, ParsedType TemplateTypeTy, const DeclSpec &DS, SourceLocation IdLoc, Expr *Init, SourceLocation EllipsisLoc) { ExprResult Res = CorrectDelayedTyposInExpr(Init); if (!Res.isUsable()) return true; Init = Res.get(); if (!ConstructorD) return true; AdjustDeclIfTemplate(ConstructorD); CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(ConstructorD); if (!Constructor) { // The user wrote a constructor initializer on a function that is // not a C++ constructor. Ignore the error for now, because we may // have more member initializers coming; we'll diagnose it just // once in ActOnMemInitializers. return true; } CXXRecordDecl *ClassDecl = Constructor->getParent(); // C++ [class.base.init]p2: // Names in a mem-initializer-id are looked up in the scope of the // constructor's class and, if not found in that scope, are looked // up in the scope containing the constructor's definition. // [Note: if the constructor's class contains a member with the // same name as a direct or virtual base class of the class, a // mem-initializer-id naming the member or base class and composed // of a single identifier refers to the class member. A // mem-initializer-id for the hidden base class may be specified // using a qualified name. ] if (!SS.getScopeRep() && !TemplateTypeTy) { // Look for a member, first. DeclContext::lookup_result Result = ClassDecl->lookup(MemberOrBase); if (!Result.empty()) { ValueDecl *Member; if ((Member = dyn_cast<FieldDecl>(Result.front())) || (Member = dyn_cast<IndirectFieldDecl>(Result.front()))) { if (EllipsisLoc.isValid()) Diag(EllipsisLoc, diag::err_pack_expansion_member_init) << MemberOrBase << SourceRange(IdLoc, Init->getSourceRange().getEnd()); return BuildMemberInitializer(Member, Init, IdLoc); } } } // It didn't name a member, so see if it names a class. QualType BaseType; TypeSourceInfo *TInfo = nullptr; if (TemplateTypeTy) { BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo); } else if (DS.getTypeSpecType() == TST_decltype) { BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); } else { LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName); LookupParsedName(R, S, &SS); TypeDecl *TyD = R.getAsSingle<TypeDecl>(); if (!TyD) { if (R.isAmbiguous()) return true; // We don't want access-control diagnostics here. R.suppressDiagnostics(); if (SS.isSet() && isDependentScopeSpecifier(SS)) { bool NotUnknownSpecialization = false; DeclContext *DC = computeDeclContext(SS, false); if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC)) NotUnknownSpecialization = !Record->hasAnyDependentBases(); if (!NotUnknownSpecialization) { // When the scope specifier can refer to a member of an unknown // specialization, we take it as a type name. BaseType = CheckTypenameType(ETK_None, SourceLocation(), SS.getWithLocInContext(Context), *MemberOrBase, IdLoc); if (BaseType.isNull()) return true; R.clear(); R.setLookupName(MemberOrBase); } } // If no results were found, try to correct typos. TypoCorrection Corr; if (R.empty() && BaseType.isNull() && (Corr = CorrectTypo( R.getLookupNameInfo(), R.getLookupKind(), S, &SS, llvm::make_unique<MemInitializerValidatorCCC>(ClassDecl), CTK_ErrorRecovery, ClassDecl))) { if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) { // We have found a non-static data member with a similar // name to what was typed; complain and initialize that // member. diagnoseTypo(Corr, PDiag(diag::err_mem_init_not_member_or_class_suggest) << MemberOrBase << true); return BuildMemberInitializer(Member, Init, IdLoc); } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) { const CXXBaseSpecifier *DirectBaseSpec; const CXXBaseSpecifier *VirtualBaseSpec; if (FindBaseInitializer(*this, ClassDecl, Context.getTypeDeclType(Type), DirectBaseSpec, VirtualBaseSpec)) { // We have found a direct or virtual base class with a // similar name to what was typed; complain and initialize // that base class. diagnoseTypo(Corr, PDiag(diag::err_mem_init_not_member_or_class_suggest) << MemberOrBase << false, PDiag() /*Suppress note, we provide our own.*/); const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec : VirtualBaseSpec; Diag(BaseSpec->getLocStart(), diag::note_base_class_specified_here) << BaseSpec->getType() << BaseSpec->getSourceRange(); TyD = Type; } } } if (!TyD && BaseType.isNull()) { Diag(IdLoc, diag::err_mem_init_not_member_or_class) << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd()); return true; } } if (BaseType.isNull()) { BaseType = Context.getTypeDeclType(TyD); MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false); if (SS.isSet()) { BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(), BaseType); TInfo = Context.CreateTypeSourceInfo(BaseType); ElaboratedTypeLoc TL = TInfo->getTypeLoc().castAs<ElaboratedTypeLoc>(); TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc); TL.setElaboratedKeywordLoc(SourceLocation()); TL.setQualifierLoc(SS.getWithLocInContext(Context)); } } } if (!TInfo) TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc); return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc); } /// Checks a member initializer expression for cases where reference (or /// pointer) members are bound to by-value parameters (or their addresses). static void CheckForDanglingReferenceOrPointer(Sema &S, ValueDecl *Member, Expr *Init, SourceLocation IdLoc) { QualType MemberTy = Member->getType(); // We only handle pointers and references currently. // FIXME: Would this be relevant for ObjC object pointers? Or block pointers? if (!MemberTy->isReferenceType() && !MemberTy->isPointerType()) return; const bool IsPointer = MemberTy->isPointerType(); if (IsPointer) { if (const UnaryOperator *Op = dyn_cast<UnaryOperator>(Init->IgnoreParenImpCasts())) { // The only case we're worried about with pointers requires taking the // address. if (Op->getOpcode() != UO_AddrOf) return; Init = Op->getSubExpr(); } else { // We only handle address-of expression initializers for pointers. return; } } if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Init->IgnoreParens())) { // We only warn when referring to a non-reference parameter declaration. const ParmVarDecl *Parameter = dyn_cast<ParmVarDecl>(DRE->getDecl()); if (!Parameter || Parameter->getType()->isReferenceType()) return; S.Diag(Init->getExprLoc(), IsPointer ? diag::warn_init_ptr_member_to_parameter_addr : diag::warn_bind_ref_member_to_parameter) << Member << Parameter << Init->getSourceRange(); } else { // Other initializers are fine. return; } S.Diag(Member->getLocation(), diag::note_ref_or_ptr_member_declared_here) << (unsigned)IsPointer; } MemInitResult Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init, SourceLocation IdLoc) { FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member); IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member); assert((DirectMember || IndirectMember) && "Member must be a FieldDecl or IndirectFieldDecl"); if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer)) return true; if (Member->isInvalidDecl()) return true; MultiExprArg Args; if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) { Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs()); } else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) { Args = MultiExprArg(InitList->getInits(), InitList->getNumInits()); } else { // Template instantiation doesn't reconstruct ParenListExprs for us. Args = Init; } SourceRange InitRange = Init->getSourceRange(); if (Member->getType()->isDependentType() || Init->isTypeDependent()) { // Can't check initialization for a member of dependent type or when // any of the arguments are type-dependent expressions. DiscardCleanupsInEvaluationContext(); } else { bool InitList = false; if (isa<InitListExpr>(Init)) { InitList = true; Args = Init; } // Initialize the member. InitializedEntity MemberEntity = DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr) : InitializedEntity::InitializeMember(IndirectMember, nullptr); InitializationKind Kind = InitList ? InitializationKind::CreateDirectList(IdLoc) : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(), InitRange.getEnd()); InitializationSequence InitSeq(*this, MemberEntity, Kind, Args); ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args, nullptr); if (MemberInit.isInvalid()) return true; CheckForDanglingReferenceOrPointer(*this, Member, MemberInit.get(), IdLoc); // C++11 [class.base.init]p7: // The initialization of each base and member constitutes a // full-expression. MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin()); if (MemberInit.isInvalid()) return true; Init = MemberInit.get(); } if (DirectMember) { return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc, InitRange.getBegin(), Init, InitRange.getEnd()); } else { return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc, InitRange.getBegin(), Init, InitRange.getEnd()); } } MemInitResult Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init, CXXRecordDecl *ClassDecl) { SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin(); if (!LangOpts.CPlusPlus11) return Diag(NameLoc, diag::err_delegating_ctor) << TInfo->getTypeLoc().getLocalSourceRange(); Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor); bool InitList = true; MultiExprArg Args = Init; if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) { InitList = false; Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs()); } SourceRange InitRange = Init->getSourceRange(); // Initialize the object. InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation( QualType(ClassDecl->getTypeForDecl(), 0)); InitializationKind Kind = InitList ? InitializationKind::CreateDirectList(NameLoc) : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(), InitRange.getEnd()); InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args); ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind, Args, nullptr); if (DelegationInit.isInvalid()) return true; assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() && "Delegating constructor with no target?"); // C++11 [class.base.init]p7: // The initialization of each base and member constitutes a // full-expression. DelegationInit = ActOnFinishFullExpr(DelegationInit.get(), InitRange.getBegin()); if (DelegationInit.isInvalid()) return true; // If we are in a dependent context, template instantiation will // perform this type-checking again. Just save the arguments that we // received in a ParenListExpr. // FIXME: This isn't quite ideal, since our ASTs don't capture all // of the information that we have about the base // initializer. However, deconstructing the ASTs is a dicey process, // and this approach is far more likely to get the corner cases right. if (CurContext->isDependentContext()) DelegationInit = Init; return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(), DelegationInit.getAs<Expr>(), InitRange.getEnd()); } MemInitResult Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo, Expr *Init, CXXRecordDecl *ClassDecl, SourceLocation EllipsisLoc) { SourceLocation BaseLoc = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin(); if (!BaseType->isDependentType() && !BaseType->isRecordType()) return Diag(BaseLoc, diag::err_base_init_does_not_name_class) << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange(); // C++ [class.base.init]p2: // [...] Unless the mem-initializer-id names a nonstatic data // member of the constructor's class or a direct or virtual base // of that class, the mem-initializer is ill-formed. A // mem-initializer-list can initialize a base class using any // name that denotes that base class type. bool Dependent = BaseType->isDependentType() || Init->isTypeDependent(); SourceRange InitRange = Init->getSourceRange(); if (EllipsisLoc.isValid()) { // This is a pack expansion. if (!BaseType->containsUnexpandedParameterPack()) { Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) << SourceRange(BaseLoc, InitRange.getEnd()); EllipsisLoc = SourceLocation(); } } else { // Check for any unexpanded parameter packs. if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer)) return true; if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer)) return true; } // Check for direct and virtual base classes. const CXXBaseSpecifier *DirectBaseSpec = nullptr; const CXXBaseSpecifier *VirtualBaseSpec = nullptr; if (!Dependent) { if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0), BaseType)) return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl); FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec, VirtualBaseSpec); // C++ [base.class.init]p2: // Unless the mem-initializer-id names a nonstatic data member of the // constructor's class or a direct or virtual base of that class, the // mem-initializer is ill-formed. if (!DirectBaseSpec && !VirtualBaseSpec) { // If the class has any dependent bases, then it's possible that // one of those types will resolve to the same type as // BaseType. Therefore, just treat this as a dependent base // class initialization. FIXME: Should we try to check the // initialization anyway? It seems odd. if (ClassDecl->hasAnyDependentBases()) Dependent = true; else return Diag(BaseLoc, diag::err_not_direct_base_or_virtual) << BaseType << Context.getTypeDeclType(ClassDecl) << BaseTInfo->getTypeLoc().getLocalSourceRange(); } } if (Dependent) { DiscardCleanupsInEvaluationContext(); return new (Context) CXXCtorInitializer(Context, BaseTInfo, /*IsVirtual=*/false, InitRange.getBegin(), Init, InitRange.getEnd(), EllipsisLoc); } // C++ [base.class.init]p2: // If a mem-initializer-id is ambiguous because it designates both // a direct non-virtual base class and an inherited virtual base // class, the mem-initializer is ill-formed. if (DirectBaseSpec && VirtualBaseSpec) return Diag(BaseLoc, diag::err_base_init_direct_and_virtual) << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange(); const CXXBaseSpecifier *BaseSpec = DirectBaseSpec; if (!BaseSpec) BaseSpec = VirtualBaseSpec; // Initialize the base. bool InitList = true; MultiExprArg Args = Init; if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) { InitList = false; Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs()); } InitializedEntity BaseEntity = InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec); InitializationKind Kind = InitList ? InitializationKind::CreateDirectList(BaseLoc) : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(), InitRange.getEnd()); InitializationSequence InitSeq(*this, BaseEntity, Kind, Args); ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr); if (BaseInit.isInvalid()) return true; // C++11 [class.base.init]p7: // The initialization of each base and member constitutes a // full-expression. BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin()); if (BaseInit.isInvalid()) return true; // If we are in a dependent context, template instantiation will // perform this type-checking again. Just save the arguments that we // received in a ParenListExpr. // FIXME: This isn't quite ideal, since our ASTs don't capture all // of the information that we have about the base // initializer. However, deconstructing the ASTs is a dicey process, // and this approach is far more likely to get the corner cases right. if (CurContext->isDependentContext()) BaseInit = Init; return new (Context) CXXCtorInitializer(Context, BaseTInfo, BaseSpec->isVirtual(), InitRange.getBegin(), BaseInit.getAs<Expr>(), InitRange.getEnd(), EllipsisLoc); } // Create a static_cast\<T&&>(expr). static Expr *CastForMoving(Sema &SemaRef, Expr *E, QualType T = QualType()) { if (T.isNull()) T = E->getType(); QualType TargetType = SemaRef.BuildReferenceType( T, /*SpelledAsLValue*/false, SourceLocation(), DeclarationName()); SourceLocation ExprLoc = E->getLocStart(); TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo( TargetType, ExprLoc); return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E, SourceRange(ExprLoc, ExprLoc), E->getSourceRange()).get(); } /// ImplicitInitializerKind - How an implicit base or member initializer should /// initialize its base or member. enum ImplicitInitializerKind { IIK_Default, IIK_Copy, IIK_Move, IIK_Inherit }; static bool BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor, ImplicitInitializerKind ImplicitInitKind, CXXBaseSpecifier *BaseSpec, bool IsInheritedVirtualBase, CXXCtorInitializer *&CXXBaseInit) { InitializedEntity InitEntity = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec, IsInheritedVirtualBase); ExprResult BaseInit; switch (ImplicitInitKind) { case IIK_Inherit: { const CXXRecordDecl *Inherited = Constructor->getInheritedConstructor()->getParent(); const CXXRecordDecl *Base = BaseSpec->getType()->getAsCXXRecordDecl(); if (Base && Inherited->getCanonicalDecl() == Base->getCanonicalDecl()) { // C++11 [class.inhctor]p8: // Each expression in the expression-list is of the form // static_cast<T&&>(p), where p is the name of the corresponding // constructor parameter and T is the declared type of p. SmallVector<Expr*, 16> Args; for (unsigned I = 0, E = Constructor->getNumParams(); I != E; ++I) { ParmVarDecl *PD = Constructor->getParamDecl(I); ExprResult ArgExpr = SemaRef.BuildDeclRefExpr(PD, PD->getType().getNonReferenceType(), VK_LValue, SourceLocation()); if (ArgExpr.isInvalid()) return true; Args.push_back(CastForMoving(SemaRef, ArgExpr.get(), PD->getType())); } InitializationKind InitKind = InitializationKind::CreateDirect( Constructor->getLocation(), SourceLocation(), SourceLocation()); InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, Args); BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, Args); break; } } // Fall through. case IIK_Default: { InitializationKind InitKind = InitializationKind::CreateDefault(Constructor->getLocation()); InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None); BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None); break; } case IIK_Move: case IIK_Copy: { bool Moving = ImplicitInitKind == IIK_Move; ParmVarDecl *Param = Constructor->getParamDecl(0); QualType ParamType = Param->getType().getNonReferenceType(); Expr *CopyCtorArg = DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(), SourceLocation(), Param, false, Constructor->getLocation(), ParamType, VK_LValue, nullptr); SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg)); // Cast to the base class to avoid ambiguities. QualType ArgTy = SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(), ParamType.getQualifiers()); if (Moving) { CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg); } CXXCastPath BasePath; BasePath.push_back(BaseSpec); CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy, CK_UncheckedDerivedToBase, Moving ? VK_XValue : VK_LValue, &BasePath).get(); InitializationKind InitKind = InitializationKind::CreateDirect(Constructor->getLocation(), SourceLocation(), SourceLocation()); InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg); BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg); break; } } BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit); if (BaseInit.isInvalid()) return true; CXXBaseInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(), SourceLocation()), BaseSpec->isVirtual(), SourceLocation(), BaseInit.getAs<Expr>(), SourceLocation(), SourceLocation()); return false; } static bool RefersToRValueRef(Expr *MemRef) { ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl(); return Referenced->getType()->isRValueReferenceType(); } static bool BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor, ImplicitInitializerKind ImplicitInitKind, FieldDecl *Field, IndirectFieldDecl *Indirect, CXXCtorInitializer *&CXXMemberInit) { if (Field->isInvalidDecl()) return true; SourceLocation Loc = Constructor->getLocation(); if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) { bool Moving = ImplicitInitKind == IIK_Move; ParmVarDecl *Param = Constructor->getParamDecl(0); QualType ParamType = Param->getType().getNonReferenceType(); // Suppress copying zero-width bitfields. if (Field->isBitField() && Field->getBitWidthValue(SemaRef.Context) == 0) return false; Expr *MemberExprBase = DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(), SourceLocation(), Param, false, Loc, ParamType, VK_LValue, nullptr); SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase)); if (Moving) { MemberExprBase = CastForMoving(SemaRef, MemberExprBase); } // Build a reference to this field within the parameter. CXXScopeSpec SS; LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc, Sema::LookupMemberName); MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect) : cast<ValueDecl>(Field), AS_public); MemberLookup.resolveKind(); ExprResult CtorArg = SemaRef.BuildMemberReferenceExpr(MemberExprBase, ParamType, Loc, /*IsArrow=*/false, SS, /*TemplateKWLoc=*/SourceLocation(), /*FirstQualifierInScope=*/nullptr, MemberLookup, /*TemplateArgs=*/nullptr, /*S*/nullptr); if (CtorArg.isInvalid()) return true; // C++11 [class.copy]p15: // - if a member m has rvalue reference type T&&, it is direct-initialized // with static_cast<T&&>(x.m); if (RefersToRValueRef(CtorArg.get())) { CtorArg = CastForMoving(SemaRef, CtorArg.get()); } // When the field we are copying is an array, create index variables for // each dimension of the array. We use these index variables to subscript // the source array, and other clients (e.g., CodeGen) will perform the // necessary iteration with these index variables. SmallVector<VarDecl *, 4> IndexVariables; QualType BaseType = Field->getType(); QualType SizeType = SemaRef.Context.getSizeType(); bool InitializingArray = false; while (const ConstantArrayType *Array = SemaRef.Context.getAsConstantArrayType(BaseType)) { InitializingArray = true; // Create the iteration variable for this array index. IdentifierInfo *IterationVarName = nullptr; { SmallString<8> Str; llvm::raw_svector_ostream OS(Str); OS << "__i" << IndexVariables.size(); IterationVarName = &SemaRef.Context.Idents.get(OS.str()); } VarDecl *IterationVar = VarDecl::Create(SemaRef.Context, SemaRef.CurContext, Loc, Loc, IterationVarName, SizeType, SemaRef.Context.getTrivialTypeSourceInfo(SizeType, Loc), SC_None); IndexVariables.push_back(IterationVar); // Create a reference to the iteration variable. ExprResult IterationVarRef = SemaRef.BuildDeclRefExpr(IterationVar, SizeType, VK_LValue, Loc); assert(!IterationVarRef.isInvalid() && "Reference to invented variable cannot fail!"); IterationVarRef = SemaRef.DefaultLvalueConversion(IterationVarRef.get()); assert(!IterationVarRef.isInvalid() && "Conversion of invented variable cannot fail!"); // Subscript the array with this iteration variable. CtorArg = SemaRef.CreateBuiltinArraySubscriptExpr(CtorArg.get(), Loc, IterationVarRef.get(), Loc); if (CtorArg.isInvalid()) return true; BaseType = Array->getElementType(); } // The array subscript expression is an lvalue, which is wrong for moving. if (Moving && InitializingArray) CtorArg = CastForMoving(SemaRef, CtorArg.get()); // Construct the entity that we will be initializing. For an array, this // will be first element in the array, which may require several levels // of array-subscript entities. SmallVector<InitializedEntity, 4> Entities; Entities.reserve(1 + IndexVariables.size()); if (Indirect) Entities.push_back(InitializedEntity::InitializeMember(Indirect)); else Entities.push_back(InitializedEntity::InitializeMember(Field)); for (unsigned I = 0, N = IndexVariables.size(); I != N; ++I) Entities.push_back(InitializedEntity::InitializeElement(SemaRef.Context, 0, Entities.back())); // Direct-initialize to use the copy constructor. InitializationKind InitKind = InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation()); Expr *CtorArgE = CtorArg.getAs<Expr>(); InitializationSequence InitSeq(SemaRef, Entities.back(), InitKind, CtorArgE); ExprResult MemberInit = InitSeq.Perform(SemaRef, Entities.back(), InitKind, MultiExprArg(&CtorArgE, 1)); MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit); if (MemberInit.isInvalid()) return true; if (Indirect) { assert(IndexVariables.size() == 0 && "Indirect field improperly initialized"); CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc); } else CXXMemberInit = CXXCtorInitializer::Create(SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc, IndexVariables.data(), IndexVariables.size()); return false; } assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) && "Unhandled implicit init kind!"); QualType FieldBaseElementType = SemaRef.Context.getBaseElementType(Field->getType()); if (FieldBaseElementType->isRecordType()) { InitializedEntity InitEntity = Indirect? InitializedEntity::InitializeMember(Indirect) : InitializedEntity::InitializeMember(Field); InitializationKind InitKind = InitializationKind::CreateDefault(Loc); InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None); ExprResult MemberInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None); MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit); if (MemberInit.isInvalid()) return true; if (Indirect) CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Indirect, Loc, Loc, MemberInit.get(), Loc); else CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field, Loc, Loc, MemberInit.get(), Loc); return false; } if (!Field->getParent()->isUnion()) { if (FieldBaseElementType->isReferenceType()) { SemaRef.Diag(Constructor->getLocation(), diag::err_uninitialized_member_in_ctor) << (int)Constructor->isImplicit() << SemaRef.Context.getTagDeclType(Constructor->getParent()) << 0 << Field->getDeclName(); SemaRef.Diag(Field->getLocation(), diag::note_declared_at); return true; } if (FieldBaseElementType.isConstQualified()) { SemaRef.Diag(Constructor->getLocation(), diag::err_uninitialized_member_in_ctor) << (int)Constructor->isImplicit() << SemaRef.Context.getTagDeclType(Constructor->getParent()) << 1 << Field->getDeclName(); SemaRef.Diag(Field->getLocation(), diag::note_declared_at); return true; } } if (SemaRef.getLangOpts().ObjCAutoRefCount && FieldBaseElementType->isObjCRetainableType() && FieldBaseElementType.getObjCLifetime() != Qualifiers::OCL_None && FieldBaseElementType.getObjCLifetime() != Qualifiers::OCL_ExplicitNone) { // ARC: // Default-initialize Objective-C pointers to NULL. CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field, Loc, Loc, new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()), Loc); return false; } // Nothing to initialize. CXXMemberInit = nullptr; return false; } namespace { struct BaseAndFieldInfo { Sema &S; CXXConstructorDecl *Ctor; bool AnyErrorsInInits; ImplicitInitializerKind IIK; llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields; SmallVector<CXXCtorInitializer*, 8> AllToInit; llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember; BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits) : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) { bool Generated = Ctor->isImplicit() || Ctor->isDefaulted(); if (Generated && Ctor->isCopyConstructor()) IIK = IIK_Copy; else if (Generated && Ctor->isMoveConstructor()) IIK = IIK_Move; else if (Ctor->getInheritedConstructor()) IIK = IIK_Inherit; else IIK = IIK_Default; } bool isImplicitCopyOrMove() const { switch (IIK) { case IIK_Copy: case IIK_Move: return true; case IIK_Default: case IIK_Inherit: return false; } llvm_unreachable("Invalid ImplicitInitializerKind!"); } bool addFieldInitializer(CXXCtorInitializer *Init) { AllToInit.push_back(Init); // Check whether this initializer makes the field "used". if (Init->getInit()->HasSideEffects(S.Context)) S.UnusedPrivateFields.remove(Init->getAnyMember()); return false; } bool isInactiveUnionMember(FieldDecl *Field) { RecordDecl *Record = Field->getParent(); if (!Record->isUnion()) return false; if (FieldDecl *Active = ActiveUnionMember.lookup(Record->getCanonicalDecl())) return Active != Field->getCanonicalDecl(); // In an implicit copy or move constructor, ignore any in-class initializer. if (isImplicitCopyOrMove()) return true; // If there's no explicit initialization, the field is active only if it // has an in-class initializer... if (Field->hasInClassInitializer()) return false; // ... or it's an anonymous struct or union whose class has an in-class // initializer. if (!Field->isAnonymousStructOrUnion()) return true; CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl(); return !FieldRD->hasInClassInitializer(); } /// \brief Determine whether the given field is, or is within, a union member /// that is inactive (because there was an initializer given for a different /// member of the union, or because the union was not initialized at all). bool isWithinInactiveUnionMember(FieldDecl *Field, IndirectFieldDecl *Indirect) { if (!Indirect) return isInactiveUnionMember(Field); for (auto *C : Indirect->chain()) { FieldDecl *Field = dyn_cast<FieldDecl>(C); if (Field && isInactiveUnionMember(Field)) return true; } return false; } }; } /// \brief Determine whether the given type is an incomplete or zero-lenfgth /// array type. static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) { if (T->isIncompleteArrayType()) return true; while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) { if (!ArrayT->getSize()) return true; T = ArrayT->getElementType(); } return false; } static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info, FieldDecl *Field, IndirectFieldDecl *Indirect = nullptr) { if (Field->isInvalidDecl()) return false; // Overwhelmingly common case: we have a direct initializer for this field. if (CXXCtorInitializer *Init = Info.AllBaseFields.lookup(Field->getCanonicalDecl())) return Info.addFieldInitializer(Init); // C++11 [class.base.init]p8: // if the entity is a non-static data member that has a // brace-or-equal-initializer and either // -- the constructor's class is a union and no other variant member of that // union is designated by a mem-initializer-id or // -- the constructor's class is not a union, and, if the entity is a member // of an anonymous union, no other member of that union is designated by // a mem-initializer-id, // the entity is initialized as specified in [dcl.init]. // // We also apply the same rules to handle anonymous structs within anonymous // unions. if (Info.isWithinInactiveUnionMember(Field, Indirect)) return false; if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) { ExprResult DIE = SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field); if (DIE.isInvalid()) return true; CXXCtorInitializer *Init; if (Indirect) Init = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(), SourceLocation(), DIE.get(), SourceLocation()); else Init = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(), SourceLocation(), DIE.get(), SourceLocation()); return Info.addFieldInitializer(Init); } // Don't initialize incomplete or zero-length arrays. if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType())) return false; // Don't try to build an implicit initializer if there were semantic // errors in any of the initializers (and therefore we might be // missing some that the user actually wrote). if (Info.AnyErrorsInInits) return false; CXXCtorInitializer *Init = nullptr; if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field, Indirect, Init)) return true; if (!Init) return false; return Info.addFieldInitializer(Init); } bool Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor, CXXCtorInitializer *Initializer) { assert(Initializer->isDelegatingInitializer()); Constructor->setNumCtorInitializers(1); CXXCtorInitializer **initializer = new (Context) CXXCtorInitializer*[1]; memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*)); Constructor->setCtorInitializers(initializer); if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) { MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor); DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation()); } DelegatingCtorDecls.push_back(Constructor); DiagnoseUninitializedFields(*this, Constructor); return false; } bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors, ArrayRef<CXXCtorInitializer *> Initializers) { if (Constructor->isDependentContext()) { // Just store the initializers as written, they will be checked during // instantiation. if (!Initializers.empty()) { Constructor->setNumCtorInitializers(Initializers.size()); CXXCtorInitializer **baseOrMemberInitializers = new (Context) CXXCtorInitializer*[Initializers.size()]; memcpy(baseOrMemberInitializers, Initializers.data(), Initializers.size() * sizeof(CXXCtorInitializer*)); Constructor->setCtorInitializers(baseOrMemberInitializers); } // Let template instantiation know whether we had errors. if (AnyErrors) Constructor->setInvalidDecl(); return false; } BaseAndFieldInfo Info(*this, Constructor, AnyErrors); // We need to build the initializer AST according to order of construction // and not what user specified in the Initializers list. CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition(); if (!ClassDecl) return true; bool HadError = false; for (unsigned i = 0; i < Initializers.size(); i++) { CXXCtorInitializer *Member = Initializers[i]; if (Member->isBaseInitializer()) Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member; else { Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member; if (IndirectFieldDecl *F = Member->getIndirectMember()) { for (auto *C : F->chain()) { FieldDecl *FD = dyn_cast<FieldDecl>(C); if (FD && FD->getParent()->isUnion()) Info.ActiveUnionMember.insert(std::make_pair( FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl())); } } else if (FieldDecl *FD = Member->getMember()) { if (FD->getParent()->isUnion()) Info.ActiveUnionMember.insert(std::make_pair( FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl())); } } } // Keep track of the direct virtual bases. llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases; for (auto &I : ClassDecl->bases()) { if (I.isVirtual()) DirectVBases.insert(&I); } // Push virtual bases before others. for (auto &VBase : ClassDecl->vbases()) { if (CXXCtorInitializer *Value = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) { // [class.base.init]p7, per DR257: // A mem-initializer where the mem-initializer-id names a virtual base // class is ignored during execution of a constructor of any class that // is not the most derived class. if (ClassDecl->isAbstract()) { // FIXME: Provide a fixit to remove the base specifier. This requires // tracking the location of the associated comma for a base specifier. Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored) << VBase.getType() << ClassDecl; DiagnoseAbstractType(ClassDecl); } Info.AllToInit.push_back(Value); } else if (!AnyErrors && !ClassDecl->isAbstract()) { // [class.base.init]p8, per DR257: // If a given [...] base class is not named by a mem-initializer-id // [...] and the entity is not a virtual base class of an abstract // class, then [...] the entity is default-initialized. bool IsInheritedVirtualBase = !DirectVBases.count(&VBase); CXXCtorInitializer *CXXBaseInit; if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK, &VBase, IsInheritedVirtualBase, CXXBaseInit)) { HadError = true; continue; } Info.AllToInit.push_back(CXXBaseInit); } } // Non-virtual bases. for (auto &Base : ClassDecl->bases()) { // Virtuals are in the virtual base list and already constructed. if (Base.isVirtual()) continue; if (CXXCtorInitializer *Value = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) { Info.AllToInit.push_back(Value); } else if (!AnyErrors) { CXXCtorInitializer *CXXBaseInit; if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK, &Base, /*IsInheritedVirtualBase=*/false, CXXBaseInit)) { HadError = true; continue; } Info.AllToInit.push_back(CXXBaseInit); } } // Fields. for (auto *Mem : ClassDecl->decls()) { if (auto *F = dyn_cast<FieldDecl>(Mem)) { // C++ [class.bit]p2: // A declaration for a bit-field that omits the identifier declares an // unnamed bit-field. Unnamed bit-fields are not members and cannot be // initialized. if (F->isUnnamedBitfield()) continue; // If we're not generating the implicit copy/move constructor, then we'll // handle anonymous struct/union fields based on their individual // indirect fields. if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove()) continue; if (CollectFieldInitializer(*this, Info, F)) HadError = true; continue; } // Beyond this point, we only consider default initialization. if (Info.isImplicitCopyOrMove()) continue; if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) { if (F->getType()->isIncompleteArrayType()) { assert(ClassDecl->hasFlexibleArrayMember() && "Incomplete array type is not valid"); continue; } // Initialize each field of an anonymous struct individually. if (CollectFieldInitializer(*this, Info, F->getAnonField(), F)) HadError = true; continue; } } unsigned NumInitializers = Info.AllToInit.size(); if (NumInitializers > 0) { Constructor->setNumCtorInitializers(NumInitializers); CXXCtorInitializer **baseOrMemberInitializers = new (Context) CXXCtorInitializer*[NumInitializers]; memcpy(baseOrMemberInitializers, Info.AllToInit.data(), NumInitializers * sizeof(CXXCtorInitializer*)); Constructor->setCtorInitializers(baseOrMemberInitializers); // Constructors implicitly reference the base and member // destructors. MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(), Constructor->getParent()); } return HadError; } static void PopulateKeysForFields(FieldDecl *Field, SmallVectorImpl<const void*> &IdealInits) { if (const RecordType *RT = Field->getType()->getAs<RecordType>()) { const RecordDecl *RD = RT->getDecl(); if (RD->isAnonymousStructOrUnion()) { for (auto *Field : RD->fields()) PopulateKeysForFields(Field, IdealInits); return; } } IdealInits.push_back(Field->getCanonicalDecl()); } static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) { return Context.getCanonicalType(BaseType).getTypePtr(); } static const void *GetKeyForMember(ASTContext &Context, CXXCtorInitializer *Member) { if (!Member->isAnyMemberInitializer()) return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0)); return Member->getAnyMember()->getCanonicalDecl(); } static void DiagnoseBaseOrMemInitializerOrder( Sema &SemaRef, const CXXConstructorDecl *Constructor, ArrayRef<CXXCtorInitializer *> Inits) { if (Constructor->getDeclContext()->isDependentContext()) return; // Don't check initializers order unless the warning is enabled at the // location of at least one initializer. bool ShouldCheckOrder = false; for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) { CXXCtorInitializer *Init = Inits[InitIndex]; if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order, Init->getSourceLocation())) { ShouldCheckOrder = true; break; } } if (!ShouldCheckOrder) return; // Build the list of bases and members in the order that they'll // actually be initialized. The explicit initializers should be in // this same order but may be missing things. SmallVector<const void*, 32> IdealInitKeys; const CXXRecordDecl *ClassDecl = Constructor->getParent(); // 1. Virtual bases. for (const auto &VBase : ClassDecl->vbases()) IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType())); // 2. Non-virtual bases. for (const auto &Base : ClassDecl->bases()) { if (Base.isVirtual()) continue; IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType())); } // 3. Direct fields. for (auto *Field : ClassDecl->fields()) { if (Field->isUnnamedBitfield()) continue; PopulateKeysForFields(Field, IdealInitKeys); } unsigned NumIdealInits = IdealInitKeys.size(); unsigned IdealIndex = 0; CXXCtorInitializer *PrevInit = nullptr; for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) { CXXCtorInitializer *Init = Inits[InitIndex]; const void *InitKey = GetKeyForMember(SemaRef.Context, Init); // Scan forward to try to find this initializer in the idealized // initializers list. for (; IdealIndex != NumIdealInits; ++IdealIndex) if (InitKey == IdealInitKeys[IdealIndex]) break; // If we didn't find this initializer, it must be because we // scanned past it on a previous iteration. That can only // happen if we're out of order; emit a warning. if (IdealIndex == NumIdealInits && PrevInit) { Sema::SemaDiagnosticBuilder D = SemaRef.Diag(PrevInit->getSourceLocation(), diag::warn_initializer_out_of_order); if (PrevInit->isAnyMemberInitializer()) D << 0 << PrevInit->getAnyMember()->getDeclName(); else D << 1 << PrevInit->getTypeSourceInfo()->getType(); if (Init->isAnyMemberInitializer()) D << 0 << Init->getAnyMember()->getDeclName(); else D << 1 << Init->getTypeSourceInfo()->getType(); // Move back to the initializer's location in the ideal list. for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex) if (InitKey == IdealInitKeys[IdealIndex]) break; assert(IdealIndex < NumIdealInits && "initializer not found in initializer list"); } PrevInit = Init; } } namespace { bool CheckRedundantInit(Sema &S, CXXCtorInitializer *Init, CXXCtorInitializer *&PrevInit) { if (!PrevInit) { PrevInit = Init; return false; } if (FieldDecl *Field = Init->getAnyMember()) S.Diag(Init->getSourceLocation(), diag::err_multiple_mem_initialization) << Field->getDeclName() << Init->getSourceRange(); else { const Type *BaseClass = Init->getBaseClass(); assert(BaseClass && "neither field nor base"); S.Diag(Init->getSourceLocation(), diag::err_multiple_base_initialization) << QualType(BaseClass, 0) << Init->getSourceRange(); } S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer) << 0 << PrevInit->getSourceRange(); return true; } typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry; typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap; bool CheckRedundantUnionInit(Sema &S, CXXCtorInitializer *Init, RedundantUnionMap &Unions) { FieldDecl *Field = Init->getAnyMember(); RecordDecl *Parent = Field->getParent(); NamedDecl *Child = Field; while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) { if (Parent->isUnion()) { UnionEntry &En = Unions[Parent]; if (En.first && En.first != Child) { S.Diag(Init->getSourceLocation(), diag::err_multiple_mem_union_initialization) << Field->getDeclName() << Init->getSourceRange(); S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer) << 0 << En.second->getSourceRange(); return true; } if (!En.first) { En.first = Child; En.second = Init; } if (!Parent->isAnonymousStructOrUnion()) return false; } Child = Parent; Parent = cast<RecordDecl>(Parent->getDeclContext()); } return false; } } /// ActOnMemInitializers - Handle the member initializers for a constructor. void Sema::ActOnMemInitializers(Decl *ConstructorDecl, SourceLocation ColonLoc, ArrayRef<CXXCtorInitializer*> MemInits, bool AnyErrors) { if (!ConstructorDecl) return; AdjustDeclIfTemplate(ConstructorDecl); CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(ConstructorDecl); if (!Constructor) { Diag(ColonLoc, diag::err_only_constructors_take_base_inits); return; } // Mapping for the duplicate initializers check. // For member initializers, this is keyed with a FieldDecl*. // For base initializers, this is keyed with a Type*. llvm::DenseMap<const void *, CXXCtorInitializer *> Members; // Mapping for the inconsistent anonymous-union initializers check. RedundantUnionMap MemberUnions; bool HadError = false; for (unsigned i = 0; i < MemInits.size(); i++) { CXXCtorInitializer *Init = MemInits[i]; // Set the source order index. Init->setSourceOrder(i); if (Init->isAnyMemberInitializer()) { const void *Key = GetKeyForMember(Context, Init); if (CheckRedundantInit(*this, Init, Members[Key]) || CheckRedundantUnionInit(*this, Init, MemberUnions)) HadError = true; } else if (Init->isBaseInitializer()) { const void *Key = GetKeyForMember(Context, Init); if (CheckRedundantInit(*this, Init, Members[Key])) HadError = true; } else { assert(Init->isDelegatingInitializer()); // This must be the only initializer if (MemInits.size() != 1) { Diag(Init->getSourceLocation(), diag::err_delegating_initializer_alone) << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange(); // We will treat this as being the only initializer. } SetDelegatingInitializer(Constructor, MemInits[i]); // Return immediately as the initializer is set. return; } } if (HadError) return; DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits); SetCtorInitializers(Constructor, AnyErrors, MemInits); DiagnoseUninitializedFields(*this, Constructor); } void Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location, CXXRecordDecl *ClassDecl) { // Ignore dependent contexts. Also ignore unions, since their members never // have destructors implicitly called. if (ClassDecl->isDependentContext() || ClassDecl->isUnion()) return; // FIXME: all the access-control diagnostics are positioned on the // field/base declaration. That's probably good; that said, the // user might reasonably want to know why the destructor is being // emitted, and we currently don't say. // Non-static data members. for (auto *Field : ClassDecl->fields()) { if (Field->isInvalidDecl()) continue; // Don't destroy incomplete or zero-length arrays. if (isIncompleteOrZeroLengthArrayType(Context, Field->getType())) continue; QualType FieldType = Context.getBaseElementType(Field->getType()); const RecordType* RT = FieldType->getAs<RecordType>(); if (!RT) continue; CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl()); if (FieldClassDecl->isInvalidDecl()) continue; if (FieldClassDecl->hasIrrelevantDestructor()) continue; // The destructor for an implicit anonymous union member is never invoked. if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion()) continue; CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl); assert(Dtor && "No dtor found for FieldClassDecl!"); CheckDestructorAccess(Field->getLocation(), Dtor, PDiag(diag::err_access_dtor_field) << Field->getDeclName() << FieldType); MarkFunctionReferenced(Location, Dtor); DiagnoseUseOfDecl(Dtor, Location); } llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases; // Bases. for (const auto &Base : ClassDecl->bases()) { // Bases are always records in a well-formed non-dependent class. const RecordType *RT = Base.getType()->getAs<RecordType>(); // Remember direct virtual bases. if (Base.isVirtual()) DirectVirtualBases.insert(RT); CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl()); // If our base class is invalid, we probably can't get its dtor anyway. if (BaseClassDecl->isInvalidDecl()) continue; if (BaseClassDecl->hasIrrelevantDestructor()) continue; CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl); assert(Dtor && "No dtor found for BaseClassDecl!"); // FIXME: caret should be on the start of the class name CheckDestructorAccess(Base.getLocStart(), Dtor, PDiag(diag::err_access_dtor_base) << Base.getType() << Base.getSourceRange(), Context.getTypeDeclType(ClassDecl)); MarkFunctionReferenced(Location, Dtor); DiagnoseUseOfDecl(Dtor, Location); } // Virtual bases. for (const auto &VBase : ClassDecl->vbases()) { // Bases are always records in a well-formed non-dependent class. const RecordType *RT = VBase.getType()->castAs<RecordType>(); // Ignore direct virtual bases. if (DirectVirtualBases.count(RT)) continue; CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl()); // If our base class is invalid, we probably can't get its dtor anyway. if (BaseClassDecl->isInvalidDecl()) continue; if (BaseClassDecl->hasIrrelevantDestructor()) continue; CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl); assert(Dtor && "No dtor found for BaseClassDecl!"); if (CheckDestructorAccess( ClassDecl->getLocation(), Dtor, PDiag(diag::err_access_dtor_vbase) << Context.getTypeDeclType(ClassDecl) << VBase.getType(), Context.getTypeDeclType(ClassDecl)) == AR_accessible) { CheckDerivedToBaseConversion( Context.getTypeDeclType(ClassDecl), VBase.getType(), diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(), SourceRange(), DeclarationName(), nullptr); } MarkFunctionReferenced(Location, Dtor); DiagnoseUseOfDecl(Dtor, Location); } } void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) { if (!CDtorDecl) return; if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(CDtorDecl)) { SetCtorInitializers(Constructor, /*AnyErrors=*/false); DiagnoseUninitializedFields(*this, Constructor); } } bool Sema::isAbstractType(SourceLocation Loc, QualType T) { if (!getLangOpts().CPlusPlus) return false; const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl(); if (!RD) return false; // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a // class template specialization here, but doing so breaks a lot of code. // We can't answer whether something is abstract until it has a // definition. If it's currently being defined, we'll walk back // over all the declarations when we have a full definition. const CXXRecordDecl *Def = RD->getDefinition(); if (!Def || Def->isBeingDefined()) return false; return RD->isAbstract(); } bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T, TypeDiagnoser &Diagnoser) { if (!isAbstractType(Loc, T)) return false; T = Context.getBaseElementType(T); Diagnoser.diagnose(*this, Loc, T); DiagnoseAbstractType(T->getAsCXXRecordDecl()); return true; } void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) { // Check if we've already emitted the list of pure virtual functions // for this class. if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD)) return; // If the diagnostic is suppressed, don't emit the notes. We're only // going to emit them once, so try to attach them to a diagnostic we're // actually going to show. if (Diags.isLastDiagnosticIgnored()) return; CXXFinalOverriderMap FinalOverriders; RD->getFinalOverriders(FinalOverriders); // Keep a set of seen pure methods so we won't diagnose the same method // more than once. llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods; for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(), MEnd = FinalOverriders.end(); M != MEnd; ++M) { for (OverridingMethods::iterator SO = M->second.begin(), SOEnd = M->second.end(); SO != SOEnd; ++SO) { // C++ [class.abstract]p4: // A class is abstract if it contains or inherits at least one // pure virtual function for which the final overrider is pure // virtual. // if (SO->second.size() != 1) continue; if (!SO->second.front().Method->isPure()) continue; if (!SeenPureMethods.insert(SO->second.front().Method).second) continue; Diag(SO->second.front().Method->getLocation(), diag::note_pure_virtual_function) << SO->second.front().Method->getDeclName() << RD->getDeclName(); } } if (!PureVirtualClassDiagSet) PureVirtualClassDiagSet.reset(new RecordDeclSetTy); PureVirtualClassDiagSet->insert(RD); } namespace { struct AbstractUsageInfo { Sema &S; CXXRecordDecl *Record; CanQualType AbstractType; bool Invalid; AbstractUsageInfo(Sema &S, CXXRecordDecl *Record) : S(S), Record(Record), AbstractType(S.Context.getCanonicalType( S.Context.getTypeDeclType(Record))), Invalid(false) {} void DiagnoseAbstractType() { if (Invalid) return; S.DiagnoseAbstractType(Record); Invalid = true; } void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel); }; struct CheckAbstractUsage { AbstractUsageInfo &Info; const NamedDecl *Ctx; CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx) : Info(Info), Ctx(Ctx) {} void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) { switch (TL.getTypeLocClass()) { #define ABSTRACT_TYPELOC(CLASS, PARENT) #define TYPELOC(CLASS, PARENT) \ case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break; #include "clang/AST/TypeLocNodes.def" } } void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) { Visit(TL.getReturnLoc(), Sema::AbstractReturnType); for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) { if (!TL.getParam(I)) continue; TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo(); if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType); } } void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) { Visit(TL.getElementLoc(), Sema::AbstractArrayType); } void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) { // Visit the type parameters from a permissive context. for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) { TemplateArgumentLoc TAL = TL.getArgLoc(I); if (TAL.getArgument().getKind() == TemplateArgument::Type) if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo()) Visit(TSI->getTypeLoc(), Sema::AbstractNone); // TODO: other template argument types? } } // Visit pointee types from a permissive context. #define CheckPolymorphic(Type) \ void Check(Type TL, Sema::AbstractDiagSelID Sel) { \ Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \ } CheckPolymorphic(PointerTypeLoc) CheckPolymorphic(ReferenceTypeLoc) CheckPolymorphic(MemberPointerTypeLoc) CheckPolymorphic(BlockPointerTypeLoc) CheckPolymorphic(AtomicTypeLoc) /// Handle all the types we haven't given a more specific /// implementation for above. void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) { // Every other kind of type that we haven't called out already // that has an inner type is either (1) sugar or (2) contains that // inner type in some way as a subobject. if (TypeLoc Next = TL.getNextTypeLoc()) return Visit(Next, Sel); // If there's no inner type and we're in a permissive context, // don't diagnose. if (Sel == Sema::AbstractNone) return; // Check whether the type matches the abstract type. QualType T = TL.getType(); if (T->isArrayType()) { Sel = Sema::AbstractArrayType; T = Info.S.Context.getBaseElementType(T); } CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType(); if (CT != Info.AbstractType) return; // It matched; do some magic. if (Sel == Sema::AbstractArrayType) { Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type) << T << TL.getSourceRange(); } else { Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl) << Sel << T << TL.getSourceRange(); } Info.DiagnoseAbstractType(); } }; void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel) { CheckAbstractUsage(*this, D).Visit(TL, Sel); } } /// Check for invalid uses of an abstract type in a method declaration. static void CheckAbstractClassUsage(AbstractUsageInfo &Info, CXXMethodDecl *MD) { // No need to do the check on definitions, which require that // the return/param types be complete. if (MD->doesThisDeclarationHaveABody()) return; // For safety's sake, just ignore it if we don't have type source // information. This should never happen for non-implicit methods, // but... if (TypeSourceInfo *TSI = MD->getTypeSourceInfo()) Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone); } /// Check for invalid uses of an abstract type within a class definition. static void CheckAbstractClassUsage(AbstractUsageInfo &Info, CXXRecordDecl *RD) { for (auto *D : RD->decls()) { if (D->isImplicit()) continue; // Methods and method templates. if (isa<CXXMethodDecl>(D)) { CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D)); } else if (isa<FunctionTemplateDecl>(D)) { FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl(); CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD)); // Fields and static variables. } else if (isa<FieldDecl>(D)) { FieldDecl *FD = cast<FieldDecl>(D); if (TypeSourceInfo *TSI = FD->getTypeSourceInfo()) Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType); } else if (isa<VarDecl>(D)) { VarDecl *VD = cast<VarDecl>(D); if (TypeSourceInfo *TSI = VD->getTypeSourceInfo()) Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType); // Nested classes and class templates. } else if (isa<CXXRecordDecl>(D)) { CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D)); } else if (isa<ClassTemplateDecl>(D)) { CheckAbstractClassUsage(Info, cast<ClassTemplateDecl>(D)->getTemplatedDecl()); } } } static void ReferenceDllExportedMethods(Sema &S, CXXRecordDecl *Class) { Attr *ClassAttr = getDLLAttr(Class); if (!ClassAttr) return; assert(ClassAttr->getKind() == attr::DLLExport); TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind(); if (TSK == TSK_ExplicitInstantiationDeclaration) // Don't go any further if this is just an explicit instantiation // declaration. return; for (Decl *Member : Class->decls()) { auto *MD = dyn_cast<CXXMethodDecl>(Member); if (!MD) continue; if (Member->getAttr<DLLExportAttr>()) { if (MD->isUserProvided()) { // Instantiate non-default class member functions ... // .. except for certain kinds of template specializations. if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited()) continue; S.MarkFunctionReferenced(Class->getLocation(), MD); // The function will be passed to the consumer when its definition is // encountered. } else if (!MD->isTrivial() || MD->isExplicitlyDefaulted() || MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) { // Synthesize and instantiate non-trivial implicit methods, explicitly // defaulted methods, and the copy and move assignment operators. The // latter are exported even if they are trivial, because the address of // an operator can be taken and should compare equal accross libraries. DiagnosticErrorTrap Trap(S.Diags); S.MarkFunctionReferenced(Class->getLocation(), MD); if (Trap.hasErrorOccurred()) { S.Diag(ClassAttr->getLocation(), diag::note_due_to_dllexported_class) << Class->getName() << !S.getLangOpts().CPlusPlus11; break; } // There is no later point when we will see the definition of this // function, so pass it to the consumer now. S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD)); } } } } /// \brief Check class-level dllimport/dllexport attribute. void Sema::checkClassLevelDLLAttribute(CXXRecordDecl *Class) { Attr *ClassAttr = getDLLAttr(Class); // MSVC inherits DLL attributes to partial class template specializations. if (Context.getTargetInfo().getCXXABI().isMicrosoft() && !ClassAttr) { if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) { if (Attr *TemplateAttr = getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) { auto *A = cast<InheritableAttr>(TemplateAttr->clone(getASTContext())); A->setInherited(true); ClassAttr = A; } } } if (!ClassAttr) return; if (!Class->isExternallyVisible()) { Diag(Class->getLocation(), diag::err_attribute_dll_not_extern) << Class << ClassAttr; return; } if (Context.getTargetInfo().getCXXABI().isMicrosoft() && !ClassAttr->isInherited()) { // Diagnose dll attributes on members of class with dll attribute. for (Decl *Member : Class->decls()) { if (!isa<VarDecl>(Member) && !isa<CXXMethodDecl>(Member)) continue; InheritableAttr *MemberAttr = getDLLAttr(Member); if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl()) continue; Diag(MemberAttr->getLocation(), diag::err_attribute_dll_member_of_dll_class) << MemberAttr << ClassAttr; Diag(ClassAttr->getLocation(), diag::note_previous_attribute); Member->setInvalidDecl(); } } if (Class->getDescribedClassTemplate()) // Don't inherit dll attribute until the template is instantiated. return; // The class is either imported or exported. const bool ClassExported = ClassAttr->getKind() == attr::DLLExport; const bool ClassImported = !ClassExported; TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind(); // Ignore explicit dllexport on explicit class template instantiation declarations. if (ClassExported && !ClassAttr->isInherited() && TSK == TSK_ExplicitInstantiationDeclaration) { Class->dropAttr<DLLExportAttr>(); return; } // Force declaration of implicit members so they can inherit the attribute. ForceDeclarationOfImplicitMembers(Class); // FIXME: MSVC's docs say all bases must be exportable, but this doesn't // seem to be true in practice? for (Decl *Member : Class->decls()) { VarDecl *VD = dyn_cast<VarDecl>(Member); CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member); // Only methods and static fields inherit the attributes. if (!VD && !MD) continue; if (MD) { // Don't process deleted methods. if (MD->isDeleted()) continue; if (MD->isInlined()) { // MinGW does not import or export inline methods. if (!Context.getTargetInfo().getCXXABI().isMicrosoft()) continue; // MSVC versions before 2015 don't export the move assignment operators, // so don't attempt to import them if we have a definition. if (ClassImported && MD->isMoveAssignmentOperator() && !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015)) continue; } } if (!cast<NamedDecl>(Member)->isExternallyVisible()) continue; if (!getDLLAttr(Member)) { auto *NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext())); NewAttr->setInherited(true); Member->addAttr(NewAttr); } } if (ClassExported) DelayedDllExportClasses.push_back(Class); } /// \brief Perform propagation of DLL attributes from a derived class to a /// templated base class for MS compatibility. void Sema::propagateDLLAttrToBaseClassTemplate( CXXRecordDecl *Class, Attr *ClassAttr, ClassTemplateSpecializationDecl *BaseTemplateSpec, SourceLocation BaseLoc) { if (getDLLAttr( BaseTemplateSpec->getSpecializedTemplate()->getTemplatedDecl())) { // If the base class template has a DLL attribute, don't try to change it. return; } auto TSK = BaseTemplateSpec->getSpecializationKind(); if (!getDLLAttr(BaseTemplateSpec) && (TSK == TSK_Undeclared || TSK == TSK_ExplicitInstantiationDeclaration || TSK == TSK_ImplicitInstantiation)) { // The template hasn't been instantiated yet (or it has, but only as an // explicit instantiation declaration or implicit instantiation, which means // we haven't codegenned any members yet), so propagate the attribute. auto *NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext())); NewAttr->setInherited(true); BaseTemplateSpec->addAttr(NewAttr); // If the template is already instantiated, checkDLLAttributeRedeclaration() // needs to be run again to work see the new attribute. Otherwise this will // get run whenever the template is instantiated. if (TSK != TSK_Undeclared) checkClassLevelDLLAttribute(BaseTemplateSpec); return; } if (getDLLAttr(BaseTemplateSpec)) { // The template has already been specialized or instantiated with an // attribute, explicitly or through propagation. We should not try to change // it. return; } // The template was previously instantiated or explicitly specialized without // a dll attribute, It's too late for us to add an attribute, so warn that // this is unsupported. Diag(BaseLoc, diag::warn_attribute_dll_instantiated_base_class) << BaseTemplateSpec->isExplicitSpecialization(); Diag(ClassAttr->getLocation(), diag::note_attribute); if (BaseTemplateSpec->isExplicitSpecialization()) { Diag(BaseTemplateSpec->getLocation(), diag::note_template_class_explicit_specialization_was_here) << BaseTemplateSpec; } else { Diag(BaseTemplateSpec->getPointOfInstantiation(), diag::note_template_class_instantiation_was_here) << BaseTemplateSpec; } } /// \brief Perform semantic checks on a class definition that has been /// completing, introducing implicitly-declared members, checking for /// abstract types, etc. void Sema::CheckCompletedCXXClass(CXXRecordDecl *Record) { if (!Record) return; if (Record->isAbstract() && !Record->isInvalidDecl()) { AbstractUsageInfo Info(*this, Record); CheckAbstractClassUsage(Info, Record); } // If this is not an aggregate type and has no user-declared constructor, // complain about any non-static data members of reference or const scalar // type, since they will never get initializers. if (!Record->isInvalidDecl() && !Record->isDependentType() && !Record->isAggregate() && !Record->hasUserDeclaredConstructor() && !Record->isLambda()) { bool Complained = false; for (const auto *F : Record->fields()) { if (F->hasInClassInitializer() || F->isUnnamedBitfield()) continue; if (F->getType()->isReferenceType() || (F->getType().isConstQualified() && F->getType()->isScalarType())) { if (!Complained) { Diag(Record->getLocation(), diag::warn_no_constructor_for_refconst) << Record->getTagKind() << Record; Complained = true; } Diag(F->getLocation(), diag::note_refconst_member_not_initialized) << F->getType()->isReferenceType() << F->getDeclName(); } } } if (Record->getIdentifier()) { // C++ [class.mem]p13: // If T is the name of a class, then each of the following shall have a // name different from T: // - every member of every anonymous union that is a member of class T. // // C++ [class.mem]p14: // In addition, if class T has a user-declared constructor (12.1), every // non-static data member of class T shall have a name different from T. DeclContext::lookup_result R = Record->lookup(Record->getDeclName()); for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) { NamedDecl *D = *I; if ((isa<FieldDecl>(D) && Record->hasUserDeclaredConstructor()) || isa<IndirectFieldDecl>(D)) { Diag(D->getLocation(), diag::err_member_name_of_class) << D->getDeclName(); break; } } } // Warn if the class has virtual methods but non-virtual public destructor. if (Record->isPolymorphic() && !Record->isDependentType()) { CXXDestructorDecl *dtor = Record->getDestructor(); if ((!dtor || (!dtor->isVirtual() && dtor->getAccess() == AS_public)) && !Record->hasAttr<FinalAttr>()) Diag(dtor ? dtor->getLocation() : Record->getLocation(), diag::warn_non_virtual_dtor) << Context.getRecordType(Record); } if (Record->isAbstract()) { if (FinalAttr *FA = Record->getAttr<FinalAttr>()) { Diag(Record->getLocation(), diag::warn_abstract_final_class) << FA->isSpelledAsSealed(); DiagnoseAbstractType(Record); } } bool HasMethodWithOverrideControl = false, HasOverridingMethodWithoutOverrideControl = false; if (!Record->isDependentType()) { for (auto *M : Record->methods()) { // See if a method overloads virtual methods in a base // class without overriding any. if (!M->isStatic()) DiagnoseHiddenVirtualMethods(M); if (M->hasAttr<OverrideAttr>()) HasMethodWithOverrideControl = true; else if (M->size_overridden_methods() > 0) HasOverridingMethodWithoutOverrideControl = true; // Check whether the explicitly-defaulted special members are valid. if (!M->isInvalidDecl() && M->isExplicitlyDefaulted()) CheckExplicitlyDefaultedSpecialMember(M); // For an explicitly defaulted or deleted special member, we defer // determining triviality until the class is complete. That time is now! if (!M->isImplicit() && !M->isUserProvided()) { CXXSpecialMember CSM = getSpecialMember(M); if (CSM != CXXInvalid) { M->setTrivial(SpecialMemberIsTrivial(M, CSM)); // Inform the class that we've finished declaring this member. Record->finishedDefaultedOrDeletedMember(M); } } } } if (HasMethodWithOverrideControl && HasOverridingMethodWithoutOverrideControl) { // At least one method has the 'override' control declared. // Diagnose all other overridden methods which do not have 'override' specified on them. for (auto *M : Record->methods()) DiagnoseAbsenceOfOverrideControl(M); } // ms_struct is a request to use the same ABI rules as MSVC. Check // whether this class uses any C++ features that are implemented // completely differently in MSVC, and if so, emit a diagnostic. // That diagnostic defaults to an error, but we allow projects to // map it down to a warning (or ignore it). It's a fairly common // practice among users of the ms_struct pragma to mass-annotate // headers, sweeping up a bunch of types that the project doesn't // really rely on MSVC-compatible layout for. We must therefore // support "ms_struct except for C++ stuff" as a secondary ABI. if (Record->isMsStruct(Context) && (Record->isPolymorphic() || Record->getNumBases())) { Diag(Record->getLocation(), diag::warn_cxx_ms_struct); } // Declare inheriting constructors. We do this eagerly here because: // - The standard requires an eager diagnostic for conflicting inheriting // constructors from different classes. // - The lazy declaration of the other implicit constructors is so as to not // waste space and performance on classes that are not meant to be // instantiated (e.g. meta-functions). This doesn't apply to classes that // have inheriting constructors. DeclareInheritingConstructors(Record); checkClassLevelDLLAttribute(Record); } /// Look up the special member function that would be called by a special /// member function for a subobject of class type. /// /// \param Class The class type of the subobject. /// \param CSM The kind of special member function. /// \param FieldQuals If the subobject is a field, its cv-qualifiers. /// \param ConstRHS True if this is a copy operation with a const object /// on its RHS, that is, if the argument to the outer special member /// function is 'const' and this is not a field marked 'mutable'. static Sema::SpecialMemberOverloadResult *lookupCallFromSpecialMember( Sema &S, CXXRecordDecl *Class, Sema::CXXSpecialMember CSM, unsigned FieldQuals, bool ConstRHS) { unsigned LHSQuals = 0; if (CSM == Sema::CXXCopyAssignment || CSM == Sema::CXXMoveAssignment) LHSQuals = FieldQuals; unsigned RHSQuals = FieldQuals; if (CSM == Sema::CXXDefaultConstructor || CSM == Sema::CXXDestructor) RHSQuals = 0; else if (ConstRHS) RHSQuals |= Qualifiers::Const; return S.LookupSpecialMember(Class, CSM, RHSQuals & Qualifiers::Const, RHSQuals & Qualifiers::Volatile, false, LHSQuals & Qualifiers::Const, LHSQuals & Qualifiers::Volatile); } /// Is the special member function which would be selected to perform the /// specified operation on the specified class type a constexpr constructor? static bool specialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl, Sema::CXXSpecialMember CSM, unsigned Quals, bool ConstRHS) { Sema::SpecialMemberOverloadResult *SMOR = lookupCallFromSpecialMember(S, ClassDecl, CSM, Quals, ConstRHS); if (!SMOR || !SMOR->getMethod()) // A constructor we wouldn't select can't be "involved in initializing" // anything. return true; return SMOR->getMethod()->isConstexpr(); } /// Determine whether the specified special member function would be constexpr /// if it were implicitly defined. static bool defaultedSpecialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl, Sema::CXXSpecialMember CSM, bool ConstArg) { if (!S.getLangOpts().CPlusPlus11) return false; // C++11 [dcl.constexpr]p4: // In the definition of a constexpr constructor [...] bool Ctor = true; switch (CSM) { case Sema::CXXDefaultConstructor: // Since default constructor lookup is essentially trivial (and cannot // involve, for instance, template instantiation), we compute whether a // defaulted default constructor is constexpr directly within CXXRecordDecl. // // This is important for performance; we need to know whether the default // constructor is constexpr to determine whether the type is a literal type. return ClassDecl->defaultedDefaultConstructorIsConstexpr(); case Sema::CXXCopyConstructor: case Sema::CXXMoveConstructor: // For copy or move constructors, we need to perform overload resolution. break; case Sema::CXXCopyAssignment: case Sema::CXXMoveAssignment: if (!S.getLangOpts().CPlusPlus14) return false; // In C++1y, we need to perform overload resolution. Ctor = false; break; case Sema::CXXDestructor: case Sema::CXXInvalid: return false; } // -- if the class is a non-empty union, or for each non-empty anonymous // union member of a non-union class, exactly one non-static data member // shall be initialized; [DR1359] // // If we squint, this is guaranteed, since exactly one non-static data member // will be initialized (if the constructor isn't deleted), we just don't know // which one. if (Ctor && ClassDecl->isUnion()) return true; // -- the class shall not have any virtual base classes; if (Ctor && ClassDecl->getNumVBases()) return false; // C++1y [class.copy]p26: // -- [the class] is a literal type, and if (!Ctor && !ClassDecl->isLiteral()) return false; // -- every constructor involved in initializing [...] base class // sub-objects shall be a constexpr constructor; // -- the assignment operator selected to copy/move each direct base // class is a constexpr function, and for (const auto &B : ClassDecl->bases()) { const RecordType *BaseType = B.getType()->getAs<RecordType>(); if (!BaseType) continue; CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl()); if (!specialMemberIsConstexpr(S, BaseClassDecl, CSM, 0, ConstArg)) return false; } // -- every constructor involved in initializing non-static data members // [...] shall be a constexpr constructor; // -- every non-static data member and base class sub-object shall be // initialized // -- for each non-static data member of X that is of class type (or array // thereof), the assignment operator selected to copy/move that member is // a constexpr function for (const auto *F : ClassDecl->fields()) { if (F->isInvalidDecl()) continue; QualType BaseType = S.Context.getBaseElementType(F->getType()); if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) { CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl()); if (!specialMemberIsConstexpr(S, FieldRecDecl, CSM, BaseType.getCVRQualifiers(), ConstArg && !F->isMutable())) return false; } } // All OK, it's constexpr! return true; } static Sema::ImplicitExceptionSpecification computeImplicitExceptionSpec(Sema &S, SourceLocation Loc, CXXMethodDecl *MD) { switch (S.getSpecialMember(MD)) { case Sema::CXXDefaultConstructor: return S.ComputeDefaultedDefaultCtorExceptionSpec(Loc, MD); case Sema::CXXCopyConstructor: return S.ComputeDefaultedCopyCtorExceptionSpec(MD); case Sema::CXXCopyAssignment: return S.ComputeDefaultedCopyAssignmentExceptionSpec(MD); case Sema::CXXMoveConstructor: return S.ComputeDefaultedMoveCtorExceptionSpec(MD); case Sema::CXXMoveAssignment: return S.ComputeDefaultedMoveAssignmentExceptionSpec(MD); case Sema::CXXDestructor: return S.ComputeDefaultedDtorExceptionSpec(MD); case Sema::CXXInvalid: break; } assert(cast<CXXConstructorDecl>(MD)->getInheritedConstructor() && "only special members have implicit exception specs"); return S.ComputeInheritingCtorExceptionSpec(cast<CXXConstructorDecl>(MD)); } static FunctionProtoType::ExtProtoInfo getImplicitMethodEPI(Sema &S, CXXMethodDecl *MD) { FunctionProtoType::ExtProtoInfo EPI; // Build an exception specification pointing back at this member. EPI.ExceptionSpec.Type = EST_Unevaluated; EPI.ExceptionSpec.SourceDecl = MD; // Set the calling convention to the default for C++ instance methods. EPI.ExtInfo = EPI.ExtInfo.withCallingConv( S.Context.getDefaultCallingConvention(/*IsVariadic=*/false, /*IsCXXMethod=*/true)); return EPI; } void Sema::EvaluateImplicitExceptionSpec(SourceLocation Loc, CXXMethodDecl *MD) { const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>(); if (FPT->getExceptionSpecType() != EST_Unevaluated) return; // Evaluate the exception specification. auto ESI = computeImplicitExceptionSpec(*this, Loc, MD).getExceptionSpec(); // Update the type of the special member to use it. UpdateExceptionSpec(MD, ESI); // A user-provided destructor can be defined outside the class. When that // happens, be sure to update the exception specification on both // declarations. const FunctionProtoType *CanonicalFPT = MD->getCanonicalDecl()->getType()->castAs<FunctionProtoType>(); if (CanonicalFPT->getExceptionSpecType() == EST_Unevaluated) UpdateExceptionSpec(MD->getCanonicalDecl(), ESI); } void Sema::CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD) { CXXRecordDecl *RD = MD->getParent(); CXXSpecialMember CSM = getSpecialMember(MD); assert(MD->isExplicitlyDefaulted() && CSM != CXXInvalid && "not an explicitly-defaulted special member"); // Whether this was the first-declared instance of the constructor. // This affects whether we implicitly add an exception spec and constexpr. bool First = MD == MD->getCanonicalDecl(); bool HadError = false; // C++11 [dcl.fct.def.default]p1: // A function that is explicitly defaulted shall // -- be a special member function (checked elsewhere), // -- have the same type (except for ref-qualifiers, and except that a // copy operation can take a non-const reference) as an implicit // declaration, and // -- not have default arguments. unsigned ExpectedParams = 1; if (CSM == CXXDefaultConstructor || CSM == CXXDestructor) ExpectedParams = 0; if (MD->getNumParams() != ExpectedParams) { // This also checks for default arguments: a copy or move constructor with a // default argument is classified as a default constructor, and assignment // operations and destructors can't have default arguments. Diag(MD->getLocation(), diag::err_defaulted_special_member_params) << CSM << MD->getSourceRange(); HadError = true; } else if (MD->isVariadic()) { Diag(MD->getLocation(), diag::err_defaulted_special_member_variadic) << CSM << MD->getSourceRange(); HadError = true; } const FunctionProtoType *Type = MD->getType()->getAs<FunctionProtoType>(); bool CanHaveConstParam = false; if (CSM == CXXCopyConstructor) CanHaveConstParam = RD->implicitCopyConstructorHasConstParam(); else if (CSM == CXXCopyAssignment) CanHaveConstParam = RD->implicitCopyAssignmentHasConstParam(); QualType ReturnType = Context.VoidTy; if (CSM == CXXCopyAssignment || CSM == CXXMoveAssignment) { // Check for return type matching. ReturnType = Type->getReturnType(); QualType ExpectedReturnType = Context.getLValueReferenceType(Context.getTypeDeclType(RD)); if (!Context.hasSameType(ReturnType, ExpectedReturnType)) { Diag(MD->getLocation(), diag::err_defaulted_special_member_return_type) << (CSM == CXXMoveAssignment) << ExpectedReturnType; HadError = true; } // A defaulted special member cannot have cv-qualifiers. if (Type->getTypeQuals()) { Diag(MD->getLocation(), diag::err_defaulted_special_member_quals) << (CSM == CXXMoveAssignment) << getLangOpts().CPlusPlus14; HadError = true; } } // Check for parameter type matching. QualType ArgType = ExpectedParams ? Type->getParamType(0) : QualType(); bool HasConstParam = false; if (ExpectedParams && ArgType->isReferenceType()) { // Argument must be reference to possibly-const T. QualType ReferentType = ArgType->getPointeeType(); HasConstParam = ReferentType.isConstQualified(); if (ReferentType.isVolatileQualified()) { Diag(MD->getLocation(), diag::err_defaulted_special_member_volatile_param) << CSM; HadError = true; } if (HasConstParam && !CanHaveConstParam) { if (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment) { Diag(MD->getLocation(), diag::err_defaulted_special_member_copy_const_param) << (CSM == CXXCopyAssignment); // FIXME: Explain why this special member can't be const. } else { Diag(MD->getLocation(), diag::err_defaulted_special_member_move_const_param) << (CSM == CXXMoveAssignment); } HadError = true; } } else if (ExpectedParams) { // A copy assignment operator can take its argument by value, but a // defaulted one cannot. assert(CSM == CXXCopyAssignment && "unexpected non-ref argument"); Diag(MD->getLocation(), diag::err_defaulted_copy_assign_not_ref); HadError = true; } // C++11 [dcl.fct.def.default]p2: // An explicitly-defaulted function may be declared constexpr only if it // would have been implicitly declared as constexpr, // Do not apply this rule to members of class templates, since core issue 1358 // makes such functions always instantiate to constexpr functions. For // functions which cannot be constexpr (for non-constructors in C++11 and for // destructors in C++1y), this is checked elsewhere. bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, RD, CSM, HasConstParam); if ((getLangOpts().CPlusPlus14 ? !isa<CXXDestructorDecl>(MD) : isa<CXXConstructorDecl>(MD)) && MD->isConstexpr() && !Constexpr && MD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) { Diag(MD->getLocStart(), diag::err_incorrect_defaulted_constexpr) << CSM; // FIXME: Explain why the special member can't be constexpr. HadError = true; } // and may have an explicit exception-specification only if it is compatible // with the exception-specification on the implicit declaration. if (Type->hasExceptionSpec()) { // Delay the check if this is the first declaration of the special member, // since we may not have parsed some necessary in-class initializers yet. if (First) { // If the exception specification needs to be instantiated, do so now, // before we clobber it with an EST_Unevaluated specification below. if (Type->getExceptionSpecType() == EST_Uninstantiated) { InstantiateExceptionSpec(MD->getLocStart(), MD); Type = MD->getType()->getAs<FunctionProtoType>(); } DelayedDefaultedMemberExceptionSpecs.push_back(std::make_pair(MD, Type)); } else CheckExplicitlyDefaultedMemberExceptionSpec(MD, Type); } // If a function is explicitly defaulted on its first declaration, if (First) { // -- it is implicitly considered to be constexpr if the implicit // definition would be, MD->setConstexpr(Constexpr); // -- it is implicitly considered to have the same exception-specification // as if it had been implicitly declared, FunctionProtoType::ExtProtoInfo EPI = Type->getExtProtoInfo(); EPI.ExceptionSpec.Type = EST_Unevaluated; EPI.ExceptionSpec.SourceDecl = MD; MD->setType(Context.getFunctionType(ReturnType, llvm::makeArrayRef(&ArgType, ExpectedParams), EPI)); } if (ShouldDeleteSpecialMember(MD, CSM)) { if (First) { SetDeclDeleted(MD, MD->getLocation()); } else { // C++11 [dcl.fct.def.default]p4: // [For a] user-provided explicitly-defaulted function [...] if such a // function is implicitly defined as deleted, the program is ill-formed. Diag(MD->getLocation(), diag::err_out_of_line_default_deletes) << CSM; ShouldDeleteSpecialMember(MD, CSM, /*Diagnose*/true); HadError = true; } } if (HadError) MD->setInvalidDecl(); } /// Check whether the exception specification provided for an /// explicitly-defaulted special member matches the exception specification /// that would have been generated for an implicit special member, per /// C++11 [dcl.fct.def.default]p2. void Sema::CheckExplicitlyDefaultedMemberExceptionSpec( CXXMethodDecl *MD, const FunctionProtoType *SpecifiedType) { // If the exception specification was explicitly specified but hadn't been // parsed when the method was defaulted, grab it now. if (SpecifiedType->getExceptionSpecType() == EST_Unparsed) SpecifiedType = MD->getTypeSourceInfo()->getType()->castAs<FunctionProtoType>(); // Compute the implicit exception specification. CallingConv CC = Context.getDefaultCallingConvention(/*IsVariadic=*/false, /*IsCXXMethod=*/true); FunctionProtoType::ExtProtoInfo EPI(CC); EPI.ExceptionSpec = computeImplicitExceptionSpec(*this, MD->getLocation(), MD) .getExceptionSpec(); const FunctionProtoType *ImplicitType = cast<FunctionProtoType>( Context.getFunctionType(Context.VoidTy, None, EPI)); // Ensure that it matches. CheckEquivalentExceptionSpec( PDiag(diag::err_incorrect_defaulted_exception_spec) << getSpecialMember(MD), PDiag(), ImplicitType, SourceLocation(), SpecifiedType, MD->getLocation()); } void Sema::CheckDelayedMemberExceptionSpecs() { decltype(DelayedExceptionSpecChecks) Checks; decltype(DelayedDefaultedMemberExceptionSpecs) Specs; std::swap(Checks, DelayedExceptionSpecChecks); std::swap(Specs, DelayedDefaultedMemberExceptionSpecs); // Perform any deferred checking of exception specifications for virtual // destructors. for (auto &Check : Checks) CheckOverridingFunctionExceptionSpec(Check.first, Check.second); // Check that any explicitly-defaulted methods have exception specifications // compatible with their implicit exception specifications. for (auto &Spec : Specs) CheckExplicitlyDefaultedMemberExceptionSpec(Spec.first, Spec.second); } namespace { struct SpecialMemberDeletionInfo { Sema &S; CXXMethodDecl *MD; Sema::CXXSpecialMember CSM; bool Diagnose; // Properties of the special member, computed for convenience. bool IsConstructor, IsAssignment, IsMove, ConstArg; SourceLocation Loc; bool AllFieldsAreConst; SpecialMemberDeletionInfo(Sema &S, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM, bool Diagnose) : S(S), MD(MD), CSM(CSM), Diagnose(Diagnose), IsConstructor(false), IsAssignment(false), IsMove(false), ConstArg(false), Loc(MD->getLocation()), AllFieldsAreConst(true) { switch (CSM) { case Sema::CXXDefaultConstructor: case Sema::CXXCopyConstructor: IsConstructor = true; break; case Sema::CXXMoveConstructor: IsConstructor = true; IsMove = true; break; case Sema::CXXCopyAssignment: IsAssignment = true; break; case Sema::CXXMoveAssignment: IsAssignment = true; IsMove = true; break; case Sema::CXXDestructor: break; case Sema::CXXInvalid: llvm_unreachable("invalid special member kind"); } if (MD->getNumParams()) { if (const ReferenceType *RT = MD->getParamDecl(0)->getType()->getAs<ReferenceType>()) ConstArg = RT->getPointeeType().isConstQualified(); } } bool inUnion() const { return MD->getParent()->isUnion(); } /// Look up the corresponding special member in the given class. Sema::SpecialMemberOverloadResult *lookupIn(CXXRecordDecl *Class, unsigned Quals, bool IsMutable) { return lookupCallFromSpecialMember(S, Class, CSM, Quals, ConstArg && !IsMutable); } typedef llvm::PointerUnion<CXXBaseSpecifier*, FieldDecl*> Subobject; bool shouldDeleteForBase(CXXBaseSpecifier *Base); bool shouldDeleteForField(FieldDecl *FD); bool shouldDeleteForAllConstMembers(); bool shouldDeleteForClassSubobject(CXXRecordDecl *Class, Subobject Subobj, unsigned Quals); bool shouldDeleteForSubobjectCall(Subobject Subobj, Sema::SpecialMemberOverloadResult *SMOR, bool IsDtorCallInCtor); bool isAccessible(Subobject Subobj, CXXMethodDecl *D); }; } /// Is the given special member inaccessible when used on the given /// sub-object. bool SpecialMemberDeletionInfo::isAccessible(Subobject Subobj, CXXMethodDecl *target) { /// If we're operating on a base class, the object type is the /// type of this special member. QualType objectTy; AccessSpecifier access = target->getAccess(); if (CXXBaseSpecifier *base = Subobj.dyn_cast<CXXBaseSpecifier*>()) { objectTy = S.Context.getTypeDeclType(MD->getParent()); access = CXXRecordDecl::MergeAccess(base->getAccessSpecifier(), access); // If we're operating on a field, the object type is the type of the field. } else { objectTy = S.Context.getTypeDeclType(target->getParent()); } return S.isSpecialMemberAccessibleForDeletion(target, access, objectTy); } /// Check whether we should delete a special member due to the implicit /// definition containing a call to a special member of a subobject. bool SpecialMemberDeletionInfo::shouldDeleteForSubobjectCall( Subobject Subobj, Sema::SpecialMemberOverloadResult *SMOR, bool IsDtorCallInCtor) { CXXMethodDecl *Decl = SMOR->getMethod(); FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>(); int DiagKind = -1; if (SMOR->getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted) DiagKind = !Decl ? 0 : 1; else if (SMOR->getKind() == Sema::SpecialMemberOverloadResult::Ambiguous) DiagKind = 2; else if (!isAccessible(Subobj, Decl)) DiagKind = 3; else if (!IsDtorCallInCtor && Field && Field->getParent()->isUnion() && !Decl->isTrivial()) { // A member of a union must have a trivial corresponding special member. // As a weird special case, a destructor call from a union's constructor // must be accessible and non-deleted, but need not be trivial. Such a // destructor is never actually called, but is semantically checked as // if it were. DiagKind = 4; } if (DiagKind == -1) return false; if (Diagnose) { if (Field) { S.Diag(Field->getLocation(), diag::note_deleted_special_member_class_subobject) << CSM << MD->getParent() << /*IsField*/true << Field << DiagKind << IsDtorCallInCtor; } else { CXXBaseSpecifier *Base = Subobj.get<CXXBaseSpecifier*>(); S.Diag(Base->getLocStart(), diag::note_deleted_special_member_class_subobject) << CSM << MD->getParent() << /*IsField*/false << Base->getType() << DiagKind << IsDtorCallInCtor; } if (DiagKind == 1) S.NoteDeletedFunction(Decl); // FIXME: Explain inaccessibility if DiagKind == 3. } return true; } /// Check whether we should delete a special member function due to having a /// direct or virtual base class or non-static data member of class type M. bool SpecialMemberDeletionInfo::shouldDeleteForClassSubobject( CXXRecordDecl *Class, Subobject Subobj, unsigned Quals) { FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>(); bool IsMutable = Field && Field->isMutable(); // C++11 [class.ctor]p5: // -- any direct or virtual base class, or non-static data member with no // brace-or-equal-initializer, has class type M (or array thereof) and // either M has no default constructor or overload resolution as applied // to M's default constructor results in an ambiguity or in a function // that is deleted or inaccessible // C++11 [class.copy]p11, C++11 [class.copy]p23: // -- a direct or virtual base class B that cannot be copied/moved because // overload resolution, as applied to B's corresponding special member, // results in an ambiguity or a function that is deleted or inaccessible // from the defaulted special member // C++11 [class.dtor]p5: // -- any direct or virtual base class [...] has a type with a destructor // that is deleted or inaccessible if (!(CSM == Sema::CXXDefaultConstructor && Field && Field->hasInClassInitializer()) && shouldDeleteForSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable), false)) return true; // C++11 [class.ctor]p5, C++11 [class.copy]p11: // -- any direct or virtual base class or non-static data member has a // type with a destructor that is deleted or inaccessible if (IsConstructor) { Sema::SpecialMemberOverloadResult *SMOR = S.LookupSpecialMember(Class, Sema::CXXDestructor, false, false, false, false, false); if (shouldDeleteForSubobjectCall(Subobj, SMOR, true)) return true; } return false; } /// Check whether we should delete a special member function due to the class /// having a particular direct or virtual base class. bool SpecialMemberDeletionInfo::shouldDeleteForBase(CXXBaseSpecifier *Base) { CXXRecordDecl *BaseClass = Base->getType()->getAsCXXRecordDecl(); return shouldDeleteForClassSubobject(BaseClass, Base, 0); } /// Check whether we should delete a special member function due to the class /// having a particular non-static data member. bool SpecialMemberDeletionInfo::shouldDeleteForField(FieldDecl *FD) { QualType FieldType = S.Context.getBaseElementType(FD->getType()); CXXRecordDecl *FieldRecord = FieldType->getAsCXXRecordDecl(); if (CSM == Sema::CXXDefaultConstructor) { // For a default constructor, all references must be initialized in-class // and, if a union, it must have a non-const member. if (FieldType->isReferenceType() && !FD->hasInClassInitializer()) { if (Diagnose) S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field) << MD->getParent() << FD << FieldType << /*Reference*/0; return true; } // C++11 [class.ctor]p5: any non-variant non-static data member of // const-qualified type (or array thereof) with no // brace-or-equal-initializer does not have a user-provided default // constructor. if (!inUnion() && FieldType.isConstQualified() && !FD->hasInClassInitializer() && (!FieldRecord || !FieldRecord->hasUserProvidedDefaultConstructor())) { if (Diagnose) S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field) << MD->getParent() << FD << FD->getType() << /*Const*/1; return true; } if (inUnion() && !FieldType.isConstQualified()) AllFieldsAreConst = false; } else if (CSM == Sema::CXXCopyConstructor) { // For a copy constructor, data members must not be of rvalue reference // type. if (FieldType->isRValueReferenceType()) { if (Diagnose) S.Diag(FD->getLocation(), diag::note_deleted_copy_ctor_rvalue_reference) << MD->getParent() << FD << FieldType; return true; } } else if (IsAssignment) { // For an assignment operator, data members must not be of reference type. if (FieldType->isReferenceType()) { if (Diagnose) S.Diag(FD->getLocation(), diag::note_deleted_assign_field) << IsMove << MD->getParent() << FD << FieldType << /*Reference*/0; return true; } if (!FieldRecord && FieldType.isConstQualified()) { // C++11 [class.copy]p23: // -- a non-static data member of const non-class type (or array thereof) if (Diagnose) S.Diag(FD->getLocation(), diag::note_deleted_assign_field) << IsMove << MD->getParent() << FD << FD->getType() << /*Const*/1; return true; } } if (FieldRecord) { // Some additional restrictions exist on the variant members. if (!inUnion() && FieldRecord->isUnion() && FieldRecord->isAnonymousStructOrUnion()) { bool AllVariantFieldsAreConst = true; // FIXME: Handle anonymous unions declared within anonymous unions. for (auto *UI : FieldRecord->fields()) { QualType UnionFieldType = S.Context.getBaseElementType(UI->getType()); if (!UnionFieldType.isConstQualified()) AllVariantFieldsAreConst = false; CXXRecordDecl *UnionFieldRecord = UnionFieldType->getAsCXXRecordDecl(); if (UnionFieldRecord && shouldDeleteForClassSubobject(UnionFieldRecord, UI, UnionFieldType.getCVRQualifiers())) return true; } // At least one member in each anonymous union must be non-const if (CSM == Sema::CXXDefaultConstructor && AllVariantFieldsAreConst && !FieldRecord->field_empty()) { if (Diagnose) S.Diag(FieldRecord->getLocation(), diag::note_deleted_default_ctor_all_const) << MD->getParent() << /*anonymous union*/1; return true; } // Don't check the implicit member of the anonymous union type. // This is technically non-conformant, but sanity demands it. return false; } if (shouldDeleteForClassSubobject(FieldRecord, FD, FieldType.getCVRQualifiers())) return true; } return false; } /// C++11 [class.ctor] p5: /// A defaulted default constructor for a class X is defined as deleted if /// X is a union and all of its variant members are of const-qualified type. bool SpecialMemberDeletionInfo::shouldDeleteForAllConstMembers() { // This is a silly definition, because it gives an empty union a deleted // default constructor. Don't do that. if (CSM == Sema::CXXDefaultConstructor && inUnion() && AllFieldsAreConst && !MD->getParent()->field_empty()) { if (Diagnose) S.Diag(MD->getParent()->getLocation(), diag::note_deleted_default_ctor_all_const) << MD->getParent() << /*not anonymous union*/0; return true; } return false; } /// Determine whether a defaulted special member function should be defined as /// deleted, as specified in C++11 [class.ctor]p5, C++11 [class.copy]p11, /// C++11 [class.copy]p23, and C++11 [class.dtor]p5. bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM, bool Diagnose) { if (MD->isInvalidDecl()) return false; CXXRecordDecl *RD = MD->getParent(); assert(!RD->isDependentType() && "do deletion after instantiation"); if (!LangOpts.CPlusPlus11 || RD->isInvalidDecl()) return false; // C++11 [expr.lambda.prim]p19: // The closure type associated with a lambda-expression has a // deleted (8.4.3) default constructor and a deleted copy // assignment operator. if (RD->isLambda() && (CSM == CXXDefaultConstructor || CSM == CXXCopyAssignment)) { if (Diagnose) Diag(RD->getLocation(), diag::note_lambda_decl); return true; } // For an anonymous struct or union, the copy and assignment special members // will never be used, so skip the check. For an anonymous union declared at // namespace scope, the constructor and destructor are used. if (CSM != CXXDefaultConstructor && CSM != CXXDestructor && RD->isAnonymousStructOrUnion()) return false; // C++11 [class.copy]p7, p18: // If the class definition declares a move constructor or move assignment // operator, an implicitly declared copy constructor or copy assignment // operator is defined as deleted. if (MD->isImplicit() && (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) { CXXMethodDecl *UserDeclaredMove = nullptr; // In Microsoft mode, a user-declared move only causes the deletion of the // corresponding copy operation, not both copy operations. if (RD->hasUserDeclaredMoveConstructor() && (!getLangOpts().MSVCCompat || CSM == CXXCopyConstructor)) { if (!Diagnose) return true; // Find any user-declared move constructor. for (auto *I : RD->ctors()) { if (I->isMoveConstructor()) { UserDeclaredMove = I; break; } } assert(UserDeclaredMove); } else if (RD->hasUserDeclaredMoveAssignment() && (!getLangOpts().MSVCCompat || CSM == CXXCopyAssignment)) { if (!Diagnose) return true; // Find any user-declared move assignment operator. for (auto *I : RD->methods()) { if (I->isMoveAssignmentOperator()) { UserDeclaredMove = I; break; } } assert(UserDeclaredMove); } if (UserDeclaredMove) { Diag(UserDeclaredMove->getLocation(), diag::note_deleted_copy_user_declared_move) << (CSM == CXXCopyAssignment) << RD << UserDeclaredMove->isMoveAssignmentOperator(); return true; } } // Do access control from the special member function ContextRAII MethodContext(*this, MD); // C++11 [class.dtor]p5: // -- for a virtual destructor, lookup of the non-array deallocation function // results in an ambiguity or in a function that is deleted or inaccessible if (CSM == CXXDestructor && MD->isVirtual()) { FunctionDecl *OperatorDelete = nullptr; DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Delete); if (FindDeallocationFunction(MD->getLocation(), MD->getParent(), Name, OperatorDelete, false)) { if (Diagnose) Diag(RD->getLocation(), diag::note_deleted_dtor_no_operator_delete); return true; } } SpecialMemberDeletionInfo SMI(*this, MD, CSM, Diagnose); for (auto &BI : RD->bases()) if (!BI.isVirtual() && SMI.shouldDeleteForBase(&BI)) return true; // Per DR1611, do not consider virtual bases of constructors of abstract // classes, since we are not going to construct them. if (!RD->isAbstract() || !SMI.IsConstructor) { for (auto &BI : RD->vbases()) if (SMI.shouldDeleteForBase(&BI)) return true; } for (auto *FI : RD->fields()) if (!FI->isInvalidDecl() && !FI->isUnnamedBitfield() && SMI.shouldDeleteForField(FI)) return true; if (SMI.shouldDeleteForAllConstMembers()) return true; if (getLangOpts().CUDA) { // We should delete the special member in CUDA mode if target inference // failed. return inferCUDATargetForImplicitSpecialMember(RD, CSM, MD, SMI.ConstArg, Diagnose); } return false; } /// Perform lookup for a special member of the specified kind, and determine /// whether it is trivial. If the triviality can be determined without the /// lookup, skip it. This is intended for use when determining whether a /// special member of a containing object is trivial, and thus does not ever /// perform overload resolution for default constructors. /// /// If \p Selected is not \c NULL, \c *Selected will be filled in with the /// member that was most likely to be intended to be trivial, if any. static bool findTrivialSpecialMember(Sema &S, CXXRecordDecl *RD, Sema::CXXSpecialMember CSM, unsigned Quals, bool ConstRHS, CXXMethodDecl **Selected) { if (Selected) *Selected = nullptr; switch (CSM) { case Sema::CXXInvalid: llvm_unreachable("not a special member"); case Sema::CXXDefaultConstructor: // C++11 [class.ctor]p5: // A default constructor is trivial if: // - all the [direct subobjects] have trivial default constructors // // Note, no overload resolution is performed in this case. if (RD->hasTrivialDefaultConstructor()) return true; if (Selected) { // If there's a default constructor which could have been trivial, dig it // out. Otherwise, if there's any user-provided default constructor, point // to that as an example of why there's not a trivial one. CXXConstructorDecl *DefCtor = nullptr; if (RD->needsImplicitDefaultConstructor()) S.DeclareImplicitDefaultConstructor(RD); for (auto *CI : RD->ctors()) { if (!CI->isDefaultConstructor()) continue; DefCtor = CI; if (!DefCtor->isUserProvided()) break; } *Selected = DefCtor; } return false; case Sema::CXXDestructor: // C++11 [class.dtor]p5: // A destructor is trivial if: // - all the direct [subobjects] have trivial destructors if (RD->hasTrivialDestructor()) return true; if (Selected) { if (RD->needsImplicitDestructor()) S.DeclareImplicitDestructor(RD); *Selected = RD->getDestructor(); } return false; case Sema::CXXCopyConstructor: // C++11 [class.copy]p12: // A copy constructor is trivial if: // - the constructor selected to copy each direct [subobject] is trivial if (RD->hasTrivialCopyConstructor()) { if (Quals == Qualifiers::Const) // We must either select the trivial copy constructor or reach an // ambiguity; no need to actually perform overload resolution. return true; } else if (!Selected) { return false; } // In C++98, we are not supposed to perform overload resolution here, but we // treat that as a language defect, as suggested on cxx-abi-dev, to treat // cases like B as having a non-trivial copy constructor: // struct A { template<typename T> A(T&); }; // struct B { mutable A a; }; goto NeedOverloadResolution; case Sema::CXXCopyAssignment: // C++11 [class.copy]p25: // A copy assignment operator is trivial if: // - the assignment operator selected to copy each direct [subobject] is // trivial if (RD->hasTrivialCopyAssignment()) { if (Quals == Qualifiers::Const) return true; } else if (!Selected) { return false; } // In C++98, we are not supposed to perform overload resolution here, but we // treat that as a language defect. goto NeedOverloadResolution; case Sema::CXXMoveConstructor: case Sema::CXXMoveAssignment: NeedOverloadResolution: Sema::SpecialMemberOverloadResult *SMOR = lookupCallFromSpecialMember(S, RD, CSM, Quals, ConstRHS); // The standard doesn't describe how to behave if the lookup is ambiguous. // We treat it as not making the member non-trivial, just like the standard // mandates for the default constructor. This should rarely matter, because // the member will also be deleted. if (SMOR->getKind() == Sema::SpecialMemberOverloadResult::Ambiguous) return true; if (!SMOR->getMethod()) { assert(SMOR->getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted); return false; } // We deliberately don't check if we found a deleted special member. We're // not supposed to! if (Selected) *Selected = SMOR->getMethod(); return SMOR->getMethod()->isTrivial(); } llvm_unreachable("unknown special method kind"); } static CXXConstructorDecl *findUserDeclaredCtor(CXXRecordDecl *RD) { for (auto *CI : RD->ctors()) if (!CI->isImplicit()) return CI; // Look for constructor templates. typedef CXXRecordDecl::specific_decl_iterator<FunctionTemplateDecl> tmpl_iter; for (tmpl_iter TI(RD->decls_begin()), TE(RD->decls_end()); TI != TE; ++TI) { if (CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(TI->getTemplatedDecl())) return CD; } return nullptr; } /// The kind of subobject we are checking for triviality. The values of this /// enumeration are used in diagnostics. enum TrivialSubobjectKind { /// The subobject is a base class. TSK_BaseClass, /// The subobject is a non-static data member. TSK_Field, /// The object is actually the complete object. TSK_CompleteObject }; /// Check whether the special member selected for a given type would be trivial. static bool checkTrivialSubobjectCall(Sema &S, SourceLocation SubobjLoc, QualType SubType, bool ConstRHS, Sema::CXXSpecialMember CSM, TrivialSubobjectKind Kind, bool Diagnose) { CXXRecordDecl *SubRD = SubType->getAsCXXRecordDecl(); if (!SubRD) return true; CXXMethodDecl *Selected; if (findTrivialSpecialMember(S, SubRD, CSM, SubType.getCVRQualifiers(), ConstRHS, Diagnose ? &Selected : nullptr)) return true; if (Diagnose) { if (ConstRHS) SubType.addConst(); if (!Selected && CSM == Sema::CXXDefaultConstructor) { S.Diag(SubobjLoc, diag::note_nontrivial_no_def_ctor) << Kind << SubType.getUnqualifiedType(); if (CXXConstructorDecl *CD = findUserDeclaredCtor(SubRD)) S.Diag(CD->getLocation(), diag::note_user_declared_ctor); } else if (!Selected) S.Diag(SubobjLoc, diag::note_nontrivial_no_copy) << Kind << SubType.getUnqualifiedType() << CSM << SubType; else if (Selected->isUserProvided()) { if (Kind == TSK_CompleteObject) S.Diag(Selected->getLocation(), diag::note_nontrivial_user_provided) << Kind << SubType.getUnqualifiedType() << CSM; else { S.Diag(SubobjLoc, diag::note_nontrivial_user_provided) << Kind << SubType.getUnqualifiedType() << CSM; S.Diag(Selected->getLocation(), diag::note_declared_at); } } else { if (Kind != TSK_CompleteObject) S.Diag(SubobjLoc, diag::note_nontrivial_subobject) << Kind << SubType.getUnqualifiedType() << CSM; // Explain why the defaulted or deleted special member isn't trivial. S.SpecialMemberIsTrivial(Selected, CSM, Diagnose); } } return false; } /// Check whether the members of a class type allow a special member to be /// trivial. static bool checkTrivialClassMembers(Sema &S, CXXRecordDecl *RD, Sema::CXXSpecialMember CSM, bool ConstArg, bool Diagnose) { for (const auto *FI : RD->fields()) { if (FI->isInvalidDecl() || FI->isUnnamedBitfield()) continue; QualType FieldType = S.Context.getBaseElementType(FI->getType()); // Pretend anonymous struct or union members are members of this class. if (FI->isAnonymousStructOrUnion()) { if (!checkTrivialClassMembers(S, FieldType->getAsCXXRecordDecl(), CSM, ConstArg, Diagnose)) return false; continue; } // C++11 [class.ctor]p5: // A default constructor is trivial if [...] // -- no non-static data member of its class has a // brace-or-equal-initializer if (CSM == Sema::CXXDefaultConstructor && FI->hasInClassInitializer()) { if (Diagnose) S.Diag(FI->getLocation(), diag::note_nontrivial_in_class_init) << FI; return false; } // Objective C ARC 4.3.5: // [...] nontrivally ownership-qualified types are [...] not trivially // default constructible, copy constructible, move constructible, copy // assignable, move assignable, or destructible [...] if (S.getLangOpts().ObjCAutoRefCount && FieldType.hasNonTrivialObjCLifetime()) { if (Diagnose) S.Diag(FI->getLocation(), diag::note_nontrivial_objc_ownership) << RD << FieldType.getObjCLifetime(); return false; } bool ConstRHS = ConstArg && !FI->isMutable(); if (!checkTrivialSubobjectCall(S, FI->getLocation(), FieldType, ConstRHS, CSM, TSK_Field, Diagnose)) return false; } return true; } /// Diagnose why the specified class does not have a trivial special member of /// the given kind. void Sema::DiagnoseNontrivial(const CXXRecordDecl *RD, CXXSpecialMember CSM) { QualType Ty = Context.getRecordType(RD); bool ConstArg = (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment); checkTrivialSubobjectCall(*this, RD->getLocation(), Ty, ConstArg, CSM, TSK_CompleteObject, /*Diagnose*/true); } /// Determine whether a defaulted or deleted special member function is trivial, /// as specified in C++11 [class.ctor]p5, C++11 [class.copy]p12, /// C++11 [class.copy]p25, and C++11 [class.dtor]p5. bool Sema::SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM, bool Diagnose) { assert(!MD->isUserProvided() && CSM != CXXInvalid && "not special enough"); CXXRecordDecl *RD = MD->getParent(); bool ConstArg = false; // C++11 [class.copy]p12, p25: [DR1593] // A [special member] is trivial if [...] its parameter-type-list is // equivalent to the parameter-type-list of an implicit declaration [...] switch (CSM) { case CXXDefaultConstructor: case CXXDestructor: // Trivial default constructors and destructors cannot have parameters. break; case CXXCopyConstructor: case CXXCopyAssignment: { // Trivial copy operations always have const, non-volatile parameter types. ConstArg = true; const ParmVarDecl *Param0 = MD->getParamDecl(0); const ReferenceType *RT = Param0->getType()->getAs<ReferenceType>(); if (!RT || RT->getPointeeType().getCVRQualifiers() != Qualifiers::Const) { if (Diagnose) Diag(Param0->getLocation(), diag::note_nontrivial_param_type) << Param0->getSourceRange() << Param0->getType() << Context.getLValueReferenceType( Context.getRecordType(RD).withConst()); return false; } break; } case CXXMoveConstructor: case CXXMoveAssignment: { // Trivial move operations always have non-cv-qualified parameters. const ParmVarDecl *Param0 = MD->getParamDecl(0); const RValueReferenceType *RT = Param0->getType()->getAs<RValueReferenceType>(); if (!RT || RT->getPointeeType().getCVRQualifiers()) { if (Diagnose) Diag(Param0->getLocation(), diag::note_nontrivial_param_type) << Param0->getSourceRange() << Param0->getType() << Context.getRValueReferenceType(Context.getRecordType(RD)); return false; } break; } case CXXInvalid: llvm_unreachable("not a special member"); } if (MD->getMinRequiredArguments() < MD->getNumParams()) { if (Diagnose) Diag(MD->getParamDecl(MD->getMinRequiredArguments())->getLocation(), diag::note_nontrivial_default_arg) << MD->getParamDecl(MD->getMinRequiredArguments())->getSourceRange(); return false; } if (MD->isVariadic()) { if (Diagnose) Diag(MD->getLocation(), diag::note_nontrivial_variadic); return false; } // C++11 [class.ctor]p5, C++11 [class.dtor]p5: // A copy/move [constructor or assignment operator] is trivial if // -- the [member] selected to copy/move each direct base class subobject // is trivial // // C++11 [class.copy]p12, C++11 [class.copy]p25: // A [default constructor or destructor] is trivial if // -- all the direct base classes have trivial [default constructors or // destructors] for (const auto &BI : RD->bases()) if (!checkTrivialSubobjectCall(*this, BI.getLocStart(), BI.getType(), ConstArg, CSM, TSK_BaseClass, Diagnose)) return false; // C++11 [class.ctor]p5, C++11 [class.dtor]p5: // A copy/move [constructor or assignment operator] for a class X is // trivial if // -- for each non-static data member of X that is of class type (or array // thereof), the constructor selected to copy/move that member is // trivial // // C++11 [class.copy]p12, C++11 [class.copy]p25: // A [default constructor or destructor] is trivial if // -- for all of the non-static data members of its class that are of class // type (or array thereof), each such class has a trivial [default // constructor or destructor] if (!checkTrivialClassMembers(*this, RD, CSM, ConstArg, Diagnose)) return false; // C++11 [class.dtor]p5: // A destructor is trivial if [...] // -- the destructor is not virtual if (CSM == CXXDestructor && MD->isVirtual()) { if (Diagnose) Diag(MD->getLocation(), diag::note_nontrivial_virtual_dtor) << RD; return false; } // C++11 [class.ctor]p5, C++11 [class.copy]p12, C++11 [class.copy]p25: // A [special member] for class X is trivial if [...] // -- class X has no virtual functions and no virtual base classes if (CSM != CXXDestructor && MD->getParent()->isDynamicClass()) { if (!Diagnose) return false; if (RD->getNumVBases()) { // Check for virtual bases. We already know that the corresponding // member in all bases is trivial, so vbases must all be direct. CXXBaseSpecifier &BS = *RD->vbases_begin(); assert(BS.isVirtual()); Diag(BS.getLocStart(), diag::note_nontrivial_has_virtual) << RD << 1; return false; } // Must have a virtual method. for (const auto *MI : RD->methods()) { if (MI->isVirtual()) { SourceLocation MLoc = MI->getLocStart(); Diag(MLoc, diag::note_nontrivial_has_virtual) << RD << 0; return false; } } llvm_unreachable("dynamic class with no vbases and no virtual functions"); } // Looks like it's trivial! return true; } namespace { struct FindHiddenVirtualMethod { Sema *S; CXXMethodDecl *Method; llvm::SmallPtrSet<const CXXMethodDecl *, 8> OverridenAndUsingBaseMethods; SmallVector<CXXMethodDecl *, 8> OverloadedMethods; private: /// Check whether any most overriden method from MD in Methods static bool CheckMostOverridenMethods( const CXXMethodDecl *MD, const llvm::SmallPtrSetImpl<const CXXMethodDecl *> &Methods) { if (MD->size_overridden_methods() == 0) return Methods.count(MD->getCanonicalDecl()); for (CXXMethodDecl::method_iterator I = MD->begin_overridden_methods(), E = MD->end_overridden_methods(); I != E; ++I) if (CheckMostOverridenMethods(*I, Methods)) return true; return false; } public: /// Member lookup function that determines whether a given C++ /// method overloads virtual methods in a base class without overriding any, /// to be used with CXXRecordDecl::lookupInBases(). bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) { RecordDecl *BaseRecord = Specifier->getType()->getAs<RecordType>()->getDecl(); DeclarationName Name = Method->getDeclName(); assert(Name.getNameKind() == DeclarationName::Identifier); bool foundSameNameMethod = false; SmallVector<CXXMethodDecl *, 8> overloadedMethods; for (Path.Decls = BaseRecord->lookup(Name); !Path.Decls.empty(); Path.Decls = Path.Decls.slice(1)) { NamedDecl *D = Path.Decls.front(); if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) { MD = MD->getCanonicalDecl(); foundSameNameMethod = true; // Interested only in hidden virtual methods. if (!MD->isVirtual()) continue; // If the method we are checking overrides a method from its base // don't warn about the other overloaded methods. Clang deviates from // GCC by only diagnosing overloads of inherited virtual functions that // do not override any other virtual functions in the base. GCC's // -Woverloaded-virtual diagnoses any derived function hiding a virtual // function from a base class. These cases may be better served by a // warning (not specific to virtual functions) on call sites when the // call would select a different function from the base class, were it // visible. // See FIXME in test/SemaCXX/warn-overload-virtual.cpp for an example. if (!S->IsOverload(Method, MD, false)) return true; // Collect the overload only if its hidden. if (!CheckMostOverridenMethods(MD, OverridenAndUsingBaseMethods)) overloadedMethods.push_back(MD); } } if (foundSameNameMethod) OverloadedMethods.append(overloadedMethods.begin(), overloadedMethods.end()); return foundSameNameMethod; } }; } // end anonymous namespace /// \brief Add the most overriden methods from MD to Methods static void AddMostOverridenMethods(const CXXMethodDecl *MD, llvm::SmallPtrSetImpl<const CXXMethodDecl *>& Methods) { if (MD->size_overridden_methods() == 0) Methods.insert(MD->getCanonicalDecl()); for (CXXMethodDecl::method_iterator I = MD->begin_overridden_methods(), E = MD->end_overridden_methods(); I != E; ++I) AddMostOverridenMethods(*I, Methods); } /// \brief Check if a method overloads virtual methods in a base class without /// overriding any. void Sema::FindHiddenVirtualMethods(CXXMethodDecl *MD, SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) { if (!MD->getDeclName().isIdentifier()) return; CXXBasePaths Paths(/*FindAmbiguities=*/true, // true to look in all bases. /*bool RecordPaths=*/false, /*bool DetectVirtual=*/false); FindHiddenVirtualMethod FHVM; FHVM.Method = MD; FHVM.S = this; // Keep the base methods that were overriden or introduced in the subclass // by 'using' in a set. A base method not in this set is hidden. CXXRecordDecl *DC = MD->getParent(); DeclContext::lookup_result R = DC->lookup(MD->getDeclName()); for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) { NamedDecl *ND = *I; if (UsingShadowDecl *shad = dyn_cast<UsingShadowDecl>(*I)) ND = shad->getTargetDecl(); if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND)) AddMostOverridenMethods(MD, FHVM.OverridenAndUsingBaseMethods); } if (DC->lookupInBases(FHVM, Paths)) OverloadedMethods = FHVM.OverloadedMethods; } void Sema::NoteHiddenVirtualMethods(CXXMethodDecl *MD, SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) { for (unsigned i = 0, e = OverloadedMethods.size(); i != e; ++i) { CXXMethodDecl *overloadedMD = OverloadedMethods[i]; PartialDiagnostic PD = PDiag( diag::note_hidden_overloaded_virtual_declared_here) << overloadedMD; HandleFunctionTypeMismatch(PD, MD->getType(), overloadedMD->getType()); Diag(overloadedMD->getLocation(), PD); } } /// \brief Diagnose methods which overload virtual methods in a base class /// without overriding any. void Sema::DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD) { if (MD->isInvalidDecl()) return; if (Diags.isIgnored(diag::warn_overloaded_virtual, MD->getLocation())) return; SmallVector<CXXMethodDecl *, 8> OverloadedMethods; FindHiddenVirtualMethods(MD, OverloadedMethods); if (!OverloadedMethods.empty()) { Diag(MD->getLocation(), diag::warn_overloaded_virtual) << MD << (OverloadedMethods.size() > 1); NoteHiddenVirtualMethods(MD, OverloadedMethods); } } void Sema::ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc, Decl *TagDecl, SourceLocation LBrac, SourceLocation RBrac, AttributeList *AttrList) { if (!TagDecl) return; AdjustDeclIfTemplate(TagDecl); for (const AttributeList* l = AttrList; l; l = l->getNext()) { if (l->getKind() != AttributeList::AT_Visibility) continue; l->setInvalid(); Diag(l->getLoc(), diag::warn_attribute_after_definition_ignored) << l->getName(); } ActOnFields(S, RLoc, TagDecl, llvm::makeArrayRef( // strict aliasing violation! reinterpret_cast<Decl**>(FieldCollector->getCurFields()), FieldCollector->getCurNumFields()), LBrac, RBrac, AttrList); CheckCompletedCXXClass( dyn_cast_or_null<CXXRecordDecl>(TagDecl)); } /// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared /// special functions, such as the default constructor, copy /// constructor, or destructor, to the given C++ class (C++ /// [special]p1). This routine can only be executed just before the /// definition of the class is complete. void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) { if (!ClassDecl->hasUserDeclaredConstructor()) ++ASTContext::NumImplicitDefaultConstructors; if (!ClassDecl->hasUserDeclaredCopyConstructor()) { ++ASTContext::NumImplicitCopyConstructors; // If the properties or semantics of the copy constructor couldn't be // determined while the class was being declared, force a declaration // of it now. if (ClassDecl->needsOverloadResolutionForCopyConstructor()) DeclareImplicitCopyConstructor(ClassDecl); } if (getLangOpts().CPlusPlus11 && ClassDecl->needsImplicitMoveConstructor()) { ++ASTContext::NumImplicitMoveConstructors; if (ClassDecl->needsOverloadResolutionForMoveConstructor()) DeclareImplicitMoveConstructor(ClassDecl); } if (!ClassDecl->hasUserDeclaredCopyAssignment()) { ++ASTContext::NumImplicitCopyAssignmentOperators; // If we have a dynamic class, then the copy assignment operator may be // virtual, so we have to declare it immediately. This ensures that, e.g., // it shows up in the right place in the vtable and that we diagnose // problems with the implicit exception specification. if (ClassDecl->isDynamicClass() || ClassDecl->needsOverloadResolutionForCopyAssignment()) DeclareImplicitCopyAssignment(ClassDecl); } if (getLangOpts().CPlusPlus11 && ClassDecl->needsImplicitMoveAssignment()) { ++ASTContext::NumImplicitMoveAssignmentOperators; // Likewise for the move assignment operator. if (ClassDecl->isDynamicClass() || ClassDecl->needsOverloadResolutionForMoveAssignment()) DeclareImplicitMoveAssignment(ClassDecl); } if (!ClassDecl->hasUserDeclaredDestructor()) { ++ASTContext::NumImplicitDestructors; // If we have a dynamic class, then the destructor may be virtual, so we // have to declare the destructor immediately. This ensures that, e.g., it // shows up in the right place in the vtable and that we diagnose problems // with the implicit exception specification. if (ClassDecl->isDynamicClass() || ClassDecl->needsOverloadResolutionForDestructor()) DeclareImplicitDestructor(ClassDecl); } } unsigned Sema::ActOnReenterTemplateScope(Scope *S, Decl *D) { if (!D) return 0; // The order of template parameters is not important here. All names // get added to the same scope. SmallVector<TemplateParameterList *, 4> ParameterLists; if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D)) D = TD->getTemplatedDecl(); if (auto *PSD = dyn_cast<ClassTemplatePartialSpecializationDecl>(D)) ParameterLists.push_back(PSD->getTemplateParameters()); if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) { for (unsigned i = 0; i < DD->getNumTemplateParameterLists(); ++i) ParameterLists.push_back(DD->getTemplateParameterList(i)); if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate()) ParameterLists.push_back(FTD->getTemplateParameters()); } } if (TagDecl *TD = dyn_cast<TagDecl>(D)) { for (unsigned i = 0; i < TD->getNumTemplateParameterLists(); ++i) ParameterLists.push_back(TD->getTemplateParameterList(i)); if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) { if (ClassTemplateDecl *CTD = RD->getDescribedClassTemplate()) ParameterLists.push_back(CTD->getTemplateParameters()); } } unsigned Count = 0; for (TemplateParameterList *Params : ParameterLists) { if (Params->size() > 0) // Ignore explicit specializations; they don't contribute to the template // depth. ++Count; for (NamedDecl *Param : *Params) { if (Param->getDeclName()) { S->AddDecl(Param); IdResolver.AddDecl(Param); } } } return Count; } void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, Decl *RecordD) { if (!RecordD) return; AdjustDeclIfTemplate(RecordD); CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordD); PushDeclContext(S, Record); } void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *RecordD) { if (!RecordD) return; PopDeclContext(); } /// This is used to implement the constant expression evaluation part of the /// attribute enable_if extension. There is nothing in standard C++ which would /// require reentering parameters. void Sema::ActOnReenterCXXMethodParameter(Scope *S, ParmVarDecl *Param) { if (!Param) return; S->AddDecl(Param); if (Param->getDeclName()) IdResolver.AddDecl(Param); } /// ActOnStartDelayedCXXMethodDeclaration - We have completed /// parsing a top-level (non-nested) C++ class, and we are now /// parsing those parts of the given Method declaration that could /// not be parsed earlier (C++ [class.mem]p2), such as default /// arguments. This action should enter the scope of the given /// Method declaration as if we had just parsed the qualified method /// name. However, it should not bring the parameters into scope; /// that will be performed by ActOnDelayedCXXMethodParameter. void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) { } /// ActOnDelayedCXXMethodParameter - We've already started a delayed /// C++ method declaration. We're (re-)introducing the given /// function parameter into scope for use in parsing later parts of /// the method declaration. For example, we could see an /// ActOnParamDefaultArgument event for this parameter. void Sema::ActOnDelayedCXXMethodParameter(Scope *S, Decl *ParamD) { if (!ParamD) return; ParmVarDecl *Param = cast<ParmVarDecl>(ParamD); // If this parameter has an unparsed default argument, clear it out // to make way for the parsed default argument. if (Param->hasUnparsedDefaultArg()) Param->setDefaultArg(nullptr); S->AddDecl(Param); if (Param->getDeclName()) IdResolver.AddDecl(Param); } /// ActOnFinishDelayedCXXMethodDeclaration - We have finished /// processing the delayed method declaration for Method. The method /// declaration is now considered finished. There may be a separate /// ActOnStartOfFunctionDef action later (not necessarily /// immediately!) for this method, if it was also defined inside the /// class body. void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) { if (!MethodD) return; AdjustDeclIfTemplate(MethodD); FunctionDecl *Method = cast<FunctionDecl>(MethodD); // Now that we have our default arguments, check the constructor // again. It could produce additional diagnostics or affect whether // the class has implicitly-declared destructors, among other // things. if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method)) CheckConstructor(Constructor); // Check the default arguments, which we may have added. if (!Method->isInvalidDecl()) CheckCXXDefaultArguments(Method); } /// CheckConstructorDeclarator - Called by ActOnDeclarator to check /// the well-formedness of the constructor declarator @p D with type @p /// R. If there are any errors in the declarator, this routine will /// emit diagnostics and set the invalid bit to true. In any case, the type /// will be updated to reflect a well-formed type for the constructor and /// returned. QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R, StorageClass &SC) { bool isVirtual = D.getDeclSpec().isVirtualSpecified(); // C++ [class.ctor]p3: // A constructor shall not be virtual (10.3) or static (9.4). A // constructor can be invoked for a const, volatile or const // volatile object. A constructor shall not be declared const, // volatile, or const volatile (9.3.2). if (isVirtual) { if (!D.isInvalidType()) Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be) << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc()) << SourceRange(D.getIdentifierLoc()); D.setInvalidType(); } if (SC == SC_Static) { if (!D.isInvalidType()) Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be) << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) << SourceRange(D.getIdentifierLoc()); D.setInvalidType(); SC = SC_None; } if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) { diagnoseIgnoredQualifiers( diag::err_constructor_return_type, TypeQuals, SourceLocation(), D.getDeclSpec().getConstSpecLoc(), D.getDeclSpec().getVolatileSpecLoc(), D.getDeclSpec().getRestrictSpecLoc(), D.getDeclSpec().getAtomicSpecLoc()); D.setInvalidType(); } DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo(); if (FTI.TypeQuals != 0) { if (FTI.TypeQuals & Qualifiers::Const) Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor) << "const" << SourceRange(D.getIdentifierLoc()); if (FTI.TypeQuals & Qualifiers::Volatile) Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor) << "volatile" << SourceRange(D.getIdentifierLoc()); if (FTI.TypeQuals & Qualifiers::Restrict) Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_constructor) << "restrict" << SourceRange(D.getIdentifierLoc()); D.setInvalidType(); } // C++0x [class.ctor]p4: // A constructor shall not be declared with a ref-qualifier. if (FTI.hasRefQualifier()) { Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_constructor) << FTI.RefQualifierIsLValueRef << FixItHint::CreateRemoval(FTI.getRefQualifierLoc()); D.setInvalidType(); } // Rebuild the function type "R" without any type qualifiers (in // case any of the errors above fired) and with "void" as the // return type, since constructors don't have return types. const FunctionProtoType *Proto = R->getAs<FunctionProtoType>(); if (Proto->getReturnType() == Context.VoidTy && !D.isInvalidType()) return R; FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo(); EPI.TypeQuals = 0; EPI.RefQualifier = RQ_None; return Context.getFunctionType(Context.VoidTy, Proto->getParamTypes(), EPI); } /// CheckConstructor - Checks a fully-formed constructor for /// well-formedness, issuing any diagnostics required. Returns true if /// the constructor declarator is invalid. void Sema::CheckConstructor(CXXConstructorDecl *Constructor) { CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext()); if (!ClassDecl) return Constructor->setInvalidDecl(); // C++ [class.copy]p3: // A declaration of a constructor for a class X is ill-formed if // its first parameter is of type (optionally cv-qualified) X and // either there are no other parameters or else all other // parameters have default arguments. if (!Constructor->isInvalidDecl() && ((Constructor->getNumParams() == 1) || (Constructor->getNumParams() > 1 && Constructor->getParamDecl(1)->hasDefaultArg())) && Constructor->getTemplateSpecializationKind() != TSK_ImplicitInstantiation) { QualType ParamType = Constructor->getParamDecl(0)->getType(); QualType ClassTy = Context.getTagDeclType(ClassDecl); if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) { SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation(); const char *ConstRef = Constructor->getParamDecl(0)->getIdentifier() ? "const &" : " const &"; Diag(ParamLoc, diag::err_constructor_byvalue_arg) << FixItHint::CreateInsertion(ParamLoc, ConstRef); // FIXME: Rather that making the constructor invalid, we should endeavor // to fix the type. Constructor->setInvalidDecl(); } } } /// CheckDestructor - Checks a fully-formed destructor definition for /// well-formedness, issuing any diagnostics required. Returns true /// on error. bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) { CXXRecordDecl *RD = Destructor->getParent(); if (!Destructor->getOperatorDelete() && Destructor->isVirtual()) { SourceLocation Loc; if (!Destructor->isImplicit()) Loc = Destructor->getLocation(); else Loc = RD->getLocation(); // If we have a virtual destructor, look up the deallocation function FunctionDecl *OperatorDelete = nullptr; DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Delete); if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete)) return true; // If there's no class-specific operator delete, look up the global // non-array delete. if (!OperatorDelete) OperatorDelete = FindUsualDeallocationFunction(Loc, true, Name); MarkFunctionReferenced(Loc, OperatorDelete); Destructor->setOperatorDelete(OperatorDelete); } return false; } /// CheckDestructorDeclarator - Called by ActOnDeclarator to check /// the well-formednes of the destructor declarator @p D with type @p /// R. If there are any errors in the declarator, this routine will /// emit diagnostics and set the declarator to invalid. Even if this happens, /// will be updated to reflect a well-formed type for the destructor and /// returned. QualType Sema::CheckDestructorDeclarator(Declarator &D, QualType R, StorageClass& SC) { // C++ [class.dtor]p1: // [...] A typedef-name that names a class is a class-name // (7.1.3); however, a typedef-name that names a class shall not // be used as the identifier in the declarator for a destructor // declaration. QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName); if (const TypedefType *TT = DeclaratorType->getAs<TypedefType>()) Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name) << DeclaratorType << isa<TypeAliasDecl>(TT->getDecl()); else if (const TemplateSpecializationType *TST = DeclaratorType->getAs<TemplateSpecializationType>()) if (TST->isTypeAlias()) Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name) << DeclaratorType << 1; // C++ [class.dtor]p2: // A destructor is used to destroy objects of its class type. A // destructor takes no parameters, and no return type can be // specified for it (not even void). The address of a destructor // shall not be taken. A destructor shall not be static. A // destructor can be invoked for a const, volatile or const // volatile object. A destructor shall not be declared const, // volatile or const volatile (9.3.2). if (SC == SC_Static) { if (!D.isInvalidType()) Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be) << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) << SourceRange(D.getIdentifierLoc()) << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc()); SC = SC_None; } if (!D.isInvalidType()) { // Destructors don't have return types, but the parser will // happily parse something like: // // class X { // float ~X(); // }; // // The return type will be eliminated later. if (D.getDeclSpec().hasTypeSpecifier()) Diag(D.getIdentifierLoc(), diag::err_destructor_return_type) << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) << SourceRange(D.getIdentifierLoc()); else if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) { diagnoseIgnoredQualifiers(diag::err_destructor_return_type, TypeQuals, SourceLocation(), D.getDeclSpec().getConstSpecLoc(), D.getDeclSpec().getVolatileSpecLoc(), D.getDeclSpec().getRestrictSpecLoc(), D.getDeclSpec().getAtomicSpecLoc()); D.setInvalidType(); } } DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo(); if (FTI.TypeQuals != 0 && !D.isInvalidType()) { if (FTI.TypeQuals & Qualifiers::Const) Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor) << "const" << SourceRange(D.getIdentifierLoc()); if (FTI.TypeQuals & Qualifiers::Volatile) Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor) << "volatile" << SourceRange(D.getIdentifierLoc()); if (FTI.TypeQuals & Qualifiers::Restrict) Diag(D.getIdentifierLoc(), diag::err_invalid_qualified_destructor) << "restrict" << SourceRange(D.getIdentifierLoc()); D.setInvalidType(); } // C++0x [class.dtor]p2: // A destructor shall not be declared with a ref-qualifier. if (FTI.hasRefQualifier()) { Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_destructor) << FTI.RefQualifierIsLValueRef << FixItHint::CreateRemoval(FTI.getRefQualifierLoc()); D.setInvalidType(); } // Make sure we don't have any parameters. if (FTIHasNonVoidParameters(FTI)) { Diag(D.getIdentifierLoc(), diag::err_destructor_with_params); // Delete the parameters. FTI.freeParams(); D.setInvalidType(); } // Make sure the destructor isn't variadic. if (FTI.isVariadic) { Diag(D.getIdentifierLoc(), diag::err_destructor_variadic); D.setInvalidType(); } // Rebuild the function type "R" without any type qualifiers or // parameters (in case any of the errors above fired) and with // "void" as the return type, since destructors don't have return // types. if (!D.isInvalidType()) return R; const FunctionProtoType *Proto = R->getAs<FunctionProtoType>(); FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo(); EPI.Variadic = false; EPI.TypeQuals = 0; EPI.RefQualifier = RQ_None; return Context.getFunctionType(Context.VoidTy, None, EPI); } static void extendLeft(SourceRange &R, SourceRange Before) { if (Before.isInvalid()) return; R.setBegin(Before.getBegin()); if (R.getEnd().isInvalid()) R.setEnd(Before.getEnd()); } static void extendRight(SourceRange &R, SourceRange After) { if (After.isInvalid()) return; if (R.getBegin().isInvalid()) R.setBegin(After.getBegin()); R.setEnd(After.getEnd()); } /// CheckConversionDeclarator - Called by ActOnDeclarator to check the /// well-formednes of the conversion function declarator @p D with /// type @p R. If there are any errors in the declarator, this routine /// will emit diagnostics and return true. Otherwise, it will return /// false. Either way, the type @p R will be updated to reflect a /// well-formed type for the conversion operator. void Sema::CheckConversionDeclarator(Declarator &D, QualType &R, StorageClass& SC) { // C++ [class.conv.fct]p1: // Neither parameter types nor return type can be specified. The // type of a conversion function (8.3.5) is "function taking no // parameter returning conversion-type-id." if (SC == SC_Static) { if (!D.isInvalidType()) Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member) << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) << D.getName().getSourceRange(); D.setInvalidType(); SC = SC_None; } TypeSourceInfo *ConvTSI = nullptr; QualType ConvType = GetTypeFromParser(D.getName().ConversionFunctionId, &ConvTSI); if (D.getDeclSpec().hasTypeSpecifier() && !D.isInvalidType()) { // Conversion functions don't have return types, but the parser will // happily parse something like: // // class X { // float operator bool(); // }; // // The return type will be changed later anyway. Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type) << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) << SourceRange(D.getIdentifierLoc()); D.setInvalidType(); } const FunctionProtoType *Proto = R->getAs<FunctionProtoType>(); // Make sure we don't have any parameters. if (Proto->getNumParams() > 0) { Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params); // Delete the parameters. D.getFunctionTypeInfo().freeParams(); D.setInvalidType(); } else if (Proto->isVariadic()) { Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic); D.setInvalidType(); } // Diagnose "&operator bool()" and other such nonsense. This // is actually a gcc extension which we don't support. if (Proto->getReturnType() != ConvType) { bool NeedsTypedef = false; SourceRange Before, After; // Walk the chunks and extract information on them for our diagnostic. bool PastFunctionChunk = false; for (auto &Chunk : D.type_objects()) { switch (Chunk.Kind) { case DeclaratorChunk::Function: if (!PastFunctionChunk) { if (Chunk.Fun.HasTrailingReturnType) { TypeSourceInfo *TRT = nullptr; GetTypeFromParser(Chunk.Fun.getTrailingReturnType(), &TRT); if (TRT) extendRight(After, TRT->getTypeLoc().getSourceRange()); } PastFunctionChunk = true; break; } // Fall through. case DeclaratorChunk::Array: NeedsTypedef = true; extendRight(After, Chunk.getSourceRange()); break; case DeclaratorChunk::Pointer: case DeclaratorChunk::BlockPointer: case DeclaratorChunk::Reference: case DeclaratorChunk::MemberPointer: extendLeft(Before, Chunk.getSourceRange()); break; case DeclaratorChunk::Paren: extendLeft(Before, Chunk.Loc); extendRight(After, Chunk.EndLoc); break; } } SourceLocation Loc = Before.isValid() ? Before.getBegin() : After.isValid() ? After.getBegin() : D.getIdentifierLoc(); auto &&DB = Diag(Loc, diag::err_conv_function_with_complex_decl); DB << Before << After; if (!NeedsTypedef) { DB << /*don't need a typedef*/0; // If we can provide a correct fix-it hint, do so. if (After.isInvalid() && ConvTSI) { SourceLocation InsertLoc = getLocForEndOfToken(ConvTSI->getTypeLoc().getLocEnd()); DB << FixItHint::CreateInsertion(InsertLoc, " ") << FixItHint::CreateInsertionFromRange( InsertLoc, CharSourceRange::getTokenRange(Before)) << FixItHint::CreateRemoval(Before); } } else if (!Proto->getReturnType()->isDependentType()) { DB << /*typedef*/1 << Proto->getReturnType(); } else if (getLangOpts().CPlusPlus11) { DB << /*alias template*/2 << Proto->getReturnType(); } else { DB << /*might not be fixable*/3; } // Recover by incorporating the other type chunks into the result type. // Note, this does *not* change the name of the function. This is compatible // with the GCC extension: // struct S { &operator int(); } s; // int &r = s.operator int(); // ok in GCC // S::operator int&() {} // error in GCC, function name is 'operator int'. ConvType = Proto->getReturnType(); } // C++ [class.conv.fct]p4: // The conversion-type-id shall not represent a function type nor // an array type. if (ConvType->isArrayType()) { Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array); ConvType = Context.getPointerType(ConvType); D.setInvalidType(); } else if (ConvType->isFunctionType()) { Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function); ConvType = Context.getPointerType(ConvType); D.setInvalidType(); } // Rebuild the function type "R" without any parameters (in case any // of the errors above fired) and with the conversion type as the // return type. if (D.isInvalidType()) R = Context.getFunctionType(ConvType, None, Proto->getExtProtoInfo()); // C++0x explicit conversion operators. if (D.getDeclSpec().isExplicitSpecified()) Diag(D.getDeclSpec().getExplicitSpecLoc(), getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_explicit_conversion_functions : diag::ext_explicit_conversion_functions) << SourceRange(D.getDeclSpec().getExplicitSpecLoc()); } /// ActOnConversionDeclarator - Called by ActOnDeclarator to complete /// the declaration of the given C++ conversion function. This routine /// is responsible for recording the conversion function in the C++ /// class, if possible. Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) { assert(Conversion && "Expected to receive a conversion function declaration"); CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext()); // Make sure we aren't redeclaring the conversion function. QualType ConvType = Context.getCanonicalType(Conversion->getConversionType()); // C++ [class.conv.fct]p1: // [...] A conversion function is never used to convert a // (possibly cv-qualified) object to the (possibly cv-qualified) // same object type (or a reference to it), to a (possibly // cv-qualified) base class of that type (or a reference to it), // or to (possibly cv-qualified) void. // FIXME: Suppress this warning if the conversion function ends up being a // virtual function that overrides a virtual function in a base class. QualType ClassType = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl)); if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>()) ConvType = ConvTypeRef->getPointeeType(); if (Conversion->getTemplateSpecializationKind() != TSK_Undeclared && Conversion->getTemplateSpecializationKind() != TSK_ExplicitSpecialization) /* Suppress diagnostics for instantiations. */; else if (ConvType->isRecordType()) { ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType(); if (ConvType == ClassType) Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used) << ClassType; else if (IsDerivedFrom(Conversion->getLocation(), ClassType, ConvType)) Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used) << ClassType << ConvType; } else if (ConvType->isVoidType()) { Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used) << ClassType << ConvType; } if (FunctionTemplateDecl *ConversionTemplate = Conversion->getDescribedFunctionTemplate()) return ConversionTemplate; return Conversion; } //===----------------------------------------------------------------------===// // Namespace Handling //===----------------------------------------------------------------------===// /// \brief Diagnose a mismatch in 'inline' qualifiers when a namespace is /// reopened. static void DiagnoseNamespaceInlineMismatch(Sema &S, SourceLocation KeywordLoc, SourceLocation Loc, IdentifierInfo *II, bool *IsInline, NamespaceDecl *PrevNS) { assert(*IsInline != PrevNS->isInline()); // HACK: Work around a bug in libstdc++4.6's <atomic>, where // std::__atomic[0,1,2] are defined as non-inline namespaces, then reopened as // inline namespaces, with the intention of bringing names into namespace std. // // We support this just well enough to get that case working; this is not // sufficient to support reopening namespaces as inline in general. if (*IsInline && II && II->getName().startswith("__atomic") && S.getSourceManager().isInSystemHeader(Loc)) { // Mark all prior declarations of the namespace as inline. for (NamespaceDecl *NS = PrevNS->getMostRecentDecl(); NS; NS = NS->getPreviousDecl()) NS->setInline(*IsInline); // Patch up the lookup table for the containing namespace. This isn't really // correct, but it's good enough for this particular case. for (auto *I : PrevNS->decls()) if (auto *ND = dyn_cast<NamedDecl>(I)) PrevNS->getParent()->makeDeclVisibleInContext(ND); return; } if (PrevNS->isInline()) // The user probably just forgot the 'inline', so suggest that it // be added back. S.Diag(Loc, diag::warn_inline_namespace_reopened_noninline) << FixItHint::CreateInsertion(KeywordLoc, "inline "); else S.Diag(Loc, diag::err_inline_namespace_mismatch) << *IsInline; S.Diag(PrevNS->getLocation(), diag::note_previous_definition); *IsInline = PrevNS->isInline(); } /// ActOnStartNamespaceDef - This is called at the start of a namespace /// definition. Decl *Sema::ActOnStartNamespaceDef(Scope *NamespcScope, SourceLocation InlineLoc, SourceLocation NamespaceLoc, SourceLocation IdentLoc, IdentifierInfo *II, SourceLocation LBrace, AttributeList *AttrList, UsingDirectiveDecl *&UD) { SourceLocation StartLoc = InlineLoc.isValid() ? InlineLoc : NamespaceLoc; // For anonymous namespace, take the location of the left brace. SourceLocation Loc = II ? IdentLoc : LBrace; bool IsInline = InlineLoc.isValid(); bool IsInvalid = false; bool IsStd = false; bool AddToKnown = false; Scope *DeclRegionScope = NamespcScope->getParent(); NamespaceDecl *PrevNS = nullptr; if (II) { // C++ [namespace.def]p2: // The identifier in an original-namespace-definition shall not // have been previously defined in the declarative region in // which the original-namespace-definition appears. The // identifier in an original-namespace-definition is the name of // the namespace. Subsequently in that declarative region, it is // treated as an original-namespace-name. // // Since namespace names are unique in their scope, and we don't // look through using directives, just look for any ordinary names // as if by qualified name lookup. LookupResult R(*this, II, IdentLoc, LookupOrdinaryName, ForRedeclaration); LookupQualifiedName(R, CurContext->getRedeclContext()); NamedDecl *PrevDecl = R.getAsSingle<NamedDecl>(); PrevNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl); if (PrevNS) { // This is an extended namespace definition. if (IsInline != PrevNS->isInline()) DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, Loc, II, &IsInline, PrevNS); } else if (PrevDecl) { // This is an invalid name redefinition. Diag(Loc, diag::err_redefinition_different_kind) << II; Diag(PrevDecl->getLocation(), diag::note_previous_definition); IsInvalid = true; // Continue on to push Namespc as current DeclContext and return it. } else if (II->isStr("std") && CurContext->getRedeclContext()->isTranslationUnit()) { // This is the first "real" definition of the namespace "std", so update // our cache of the "std" namespace to point at this definition. PrevNS = getStdNamespace(); IsStd = true; AddToKnown = !IsInline; } else { // We've seen this namespace for the first time. AddToKnown = !IsInline; } } else { // Anonymous namespaces. // Determine whether the parent already has an anonymous namespace. DeclContext *Parent = CurContext->getRedeclContext(); if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) { PrevNS = TU->getAnonymousNamespace(); } else { NamespaceDecl *ND = cast<NamespaceDecl>(Parent); PrevNS = ND->getAnonymousNamespace(); } if (PrevNS && IsInline != PrevNS->isInline()) DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, NamespaceLoc, II, &IsInline, PrevNS); } NamespaceDecl *Namespc = NamespaceDecl::Create(Context, CurContext, IsInline, StartLoc, Loc, II, PrevNS); if (IsInvalid) Namespc->setInvalidDecl(); ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList); // FIXME: Should we be merging attributes? if (const VisibilityAttr *Attr = Namespc->getAttr<VisibilityAttr>()) PushNamespaceVisibilityAttr(Attr, Loc); if (IsStd) StdNamespace = Namespc; if (AddToKnown) KnownNamespaces[Namespc] = false; if (II) { PushOnScopeChains(Namespc, DeclRegionScope); } else { // Link the anonymous namespace into its parent. DeclContext *Parent = CurContext->getRedeclContext(); if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) { TU->setAnonymousNamespace(Namespc); } else { cast<NamespaceDecl>(Parent)->setAnonymousNamespace(Namespc); } CurContext->addDecl(Namespc); // C++ [namespace.unnamed]p1. An unnamed-namespace-definition // behaves as if it were replaced by // namespace unique { /* empty body */ } // using namespace unique; // namespace unique { namespace-body } // where all occurrences of 'unique' in a translation unit are // replaced by the same identifier and this identifier differs // from all other identifiers in the entire program. // We just create the namespace with an empty name and then add an // implicit using declaration, just like the standard suggests. // // CodeGen enforces the "universally unique" aspect by giving all // declarations semantically contained within an anonymous // namespace internal linkage. if (!PrevNS) { UD = UsingDirectiveDecl::Create(Context, Parent, /* 'using' */ LBrace, /* 'namespace' */ SourceLocation(), /* qualifier */ NestedNameSpecifierLoc(), /* identifier */ SourceLocation(), Namespc, /* Ancestor */ Parent); UD->setImplicit(); Parent->addDecl(UD); } } ActOnDocumentableDecl(Namespc); // Although we could have an invalid decl (i.e. the namespace name is a // redefinition), push it as current DeclContext and try to continue parsing. // FIXME: We should be able to push Namespc here, so that the each DeclContext // for the namespace has the declarations that showed up in that particular // namespace definition. PushDeclContext(NamespcScope, Namespc); return Namespc; } /// getNamespaceDecl - Returns the namespace a decl represents. If the decl /// is a namespace alias, returns the namespace it points to. static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) { if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D)) return AD->getNamespace(); return dyn_cast_or_null<NamespaceDecl>(D); } /// ActOnFinishNamespaceDef - This callback is called after a namespace is /// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef. void Sema::ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace) { NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl); assert(Namespc && "Invalid parameter, expected NamespaceDecl"); Namespc->setRBraceLoc(RBrace); PopDeclContext(); if (Namespc->hasAttr<VisibilityAttr>()) PopPragmaVisibility(true, RBrace); } CXXRecordDecl *Sema::getStdBadAlloc() const { return cast_or_null<CXXRecordDecl>( StdBadAlloc.get(Context.getExternalSource())); } NamespaceDecl *Sema::getStdNamespace() const { return cast_or_null<NamespaceDecl>( StdNamespace.get(Context.getExternalSource())); } /// \brief Retrieve the special "std" namespace, which may require us to /// implicitly define the namespace. NamespaceDecl *Sema::getOrCreateStdNamespace() { if (!StdNamespace) { // The "std" namespace has not yet been defined, so build one implicitly. StdNamespace = NamespaceDecl::Create(Context, Context.getTranslationUnitDecl(), /*Inline=*/false, SourceLocation(), SourceLocation(), &PP.getIdentifierTable().get("std"), /*PrevDecl=*/nullptr); getStdNamespace()->setImplicit(true); } return getStdNamespace(); } bool Sema::isStdInitializerList(QualType Ty, QualType *Element) { assert(getLangOpts().CPlusPlus && "Looking for std::initializer_list outside of C++."); // We're looking for implicit instantiations of // template <typename E> class std::initializer_list. if (!StdNamespace) // If we haven't seen namespace std yet, this can't be it. return false; ClassTemplateDecl *Template = nullptr; const TemplateArgument *Arguments = nullptr; if (const RecordType *RT = Ty->getAs<RecordType>()) { ClassTemplateSpecializationDecl *Specialization = dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl()); if (!Specialization) return false; Template = Specialization->getSpecializedTemplate(); Arguments = Specialization->getTemplateArgs().data(); } else if (const TemplateSpecializationType *TST = Ty->getAs<TemplateSpecializationType>()) { Template = dyn_cast_or_null<ClassTemplateDecl>( TST->getTemplateName().getAsTemplateDecl()); Arguments = TST->getArgs(); } if (!Template) return false; if (!StdInitializerList) { // Haven't recognized std::initializer_list yet, maybe this is it. CXXRecordDecl *TemplateClass = Template->getTemplatedDecl(); if (TemplateClass->getIdentifier() != &PP.getIdentifierTable().get("initializer_list") || !getStdNamespace()->InEnclosingNamespaceSetOf( TemplateClass->getDeclContext())) return false; // This is a template called std::initializer_list, but is it the right // template? TemplateParameterList *Params = Template->getTemplateParameters(); if (Params->getMinRequiredArguments() != 1) return false; if (!isa<TemplateTypeParmDecl>(Params->getParam(0))) return false; // It's the right template. StdInitializerList = Template; } if (Template->getCanonicalDecl() != StdInitializerList->getCanonicalDecl()) return false; // This is an instance of std::initializer_list. Find the argument type. if (Element) *Element = Arguments[0].getAsType(); return true; } static ClassTemplateDecl *LookupStdInitializerList(Sema &S, SourceLocation Loc){ NamespaceDecl *Std = S.getStdNamespace(); if (!Std) { S.Diag(Loc, diag::err_implied_std_initializer_list_not_found); return nullptr; } LookupResult Result(S, &S.PP.getIdentifierTable().get("initializer_list"), Loc, Sema::LookupOrdinaryName); if (!S.LookupQualifiedName(Result, Std)) { S.Diag(Loc, diag::err_implied_std_initializer_list_not_found); return nullptr; } ClassTemplateDecl *Template = Result.getAsSingle<ClassTemplateDecl>(); if (!Template) { Result.suppressDiagnostics(); // We found something weird. Complain about the first thing we found. NamedDecl *Found = *Result.begin(); S.Diag(Found->getLocation(), diag::err_malformed_std_initializer_list); return nullptr; } // We found some template called std::initializer_list. Now verify that it's // correct. TemplateParameterList *Params = Template->getTemplateParameters(); if (Params->getMinRequiredArguments() != 1 || !isa<TemplateTypeParmDecl>(Params->getParam(0))) { S.Diag(Template->getLocation(), diag::err_malformed_std_initializer_list); return nullptr; } return Template; } QualType Sema::BuildStdInitializerList(QualType Element, SourceLocation Loc) { if (!StdInitializerList) { StdInitializerList = LookupStdInitializerList(*this, Loc); if (!StdInitializerList) return QualType(); } TemplateArgumentListInfo Args(Loc, Loc); Args.addArgument(TemplateArgumentLoc(TemplateArgument(Element), Context.getTrivialTypeSourceInfo(Element, Loc))); return Context.getCanonicalType( CheckTemplateIdType(TemplateName(StdInitializerList), Loc, Args)); } bool Sema::isInitListConstructor(const CXXConstructorDecl* Ctor) { // C++ [dcl.init.list]p2: // A constructor is an initializer-list constructor if its first parameter // is of type std::initializer_list<E> or reference to possibly cv-qualified // std::initializer_list<E> for some type E, and either there are no other // parameters or else all other parameters have default arguments. if (Ctor->getNumParams() < 1 || (Ctor->getNumParams() > 1 && !Ctor->getParamDecl(1)->hasDefaultArg())) return false; QualType ArgType = Ctor->getParamDecl(0)->getType(); if (const ReferenceType *RT = ArgType->getAs<ReferenceType>()) ArgType = RT->getPointeeType().getUnqualifiedType(); return isStdInitializerList(ArgType, nullptr); } /// \brief Determine whether a using statement is in a context where it will be /// apply in all contexts. static bool IsUsingDirectiveInToplevelContext(DeclContext *CurContext) { switch (CurContext->getDeclKind()) { case Decl::TranslationUnit: return true; case Decl::LinkageSpec: return IsUsingDirectiveInToplevelContext(CurContext->getParent()); default: return false; } } namespace { // Callback to only accept typo corrections that are namespaces. class NamespaceValidatorCCC : public CorrectionCandidateCallback { public: bool ValidateCandidate(const TypoCorrection &candidate) override { if (NamedDecl *ND = candidate.getCorrectionDecl()) return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND); return false; } }; } static bool TryNamespaceTypoCorrection(Sema &S, LookupResult &R, Scope *Sc, CXXScopeSpec &SS, SourceLocation IdentLoc, IdentifierInfo *Ident) { R.clear(); if (TypoCorrection Corrected = S.CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), Sc, &SS, llvm::make_unique<NamespaceValidatorCCC>(), Sema::CTK_ErrorRecovery)) { if (DeclContext *DC = S.computeDeclContext(SS, false)) { std::string CorrectedStr(Corrected.getAsString(S.getLangOpts())); bool DroppedSpecifier = Corrected.WillReplaceSpecifier() && Ident->getName().equals(CorrectedStr); S.diagnoseTypo(Corrected, S.PDiag(diag::err_using_directive_member_suggest) << Ident << DC << DroppedSpecifier << SS.getRange(), S.PDiag(diag::note_namespace_defined_here)); } else { S.diagnoseTypo(Corrected, S.PDiag(diag::err_using_directive_suggest) << Ident, S.PDiag(diag::note_namespace_defined_here)); } R.addDecl(Corrected.getCorrectionDecl()); return true; } return false; } Decl *Sema::ActOnUsingDirective(Scope *S, SourceLocation UsingLoc, SourceLocation NamespcLoc, CXXScopeSpec &SS, SourceLocation IdentLoc, IdentifierInfo *NamespcName, AttributeList *AttrList) { assert(!SS.isInvalid() && "Invalid CXXScopeSpec."); assert(NamespcName && "Invalid NamespcName."); assert(IdentLoc.isValid() && "Invalid NamespceName location."); // This can only happen along a recovery path. while (S->isTemplateParamScope()) S = S->getParent(); assert(S->getFlags() & Scope::DeclScope && "Invalid Scope."); UsingDirectiveDecl *UDir = nullptr; NestedNameSpecifier *Qualifier = nullptr; if (SS.isSet()) Qualifier = SS.getScopeRep(); // Lookup namespace name. LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName); LookupParsedName(R, S, &SS); if (R.isAmbiguous()) return nullptr; if (R.empty()) { R.clear(); // Allow "using namespace std;" or "using namespace ::std;" even if // "std" hasn't been defined yet, for GCC compatibility. if ((!Qualifier || Qualifier->getKind() == NestedNameSpecifier::Global) && NamespcName->isStr("std")) { Diag(IdentLoc, diag::ext_using_undefined_std); R.addDecl(getOrCreateStdNamespace()); R.resolveKind(); } // Otherwise, attempt typo correction. else TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, NamespcName); } if (!R.empty()) { NamedDecl *Named = R.getFoundDecl(); assert((isa<NamespaceDecl>(Named) || isa<NamespaceAliasDecl>(Named)) && "expected namespace decl"); // The use of a nested name specifier may trigger deprecation warnings. DiagnoseUseOfDecl(Named, IdentLoc); // C++ [namespace.udir]p1: // A using-directive specifies that the names in the nominated // namespace can be used in the scope in which the // using-directive appears after the using-directive. 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". ] // Find enclosing context containing both using-directive and // nominated namespace. NamespaceDecl *NS = getNamespaceDecl(Named); DeclContext *CommonAncestor = cast<DeclContext>(NS); while (CommonAncestor && !CommonAncestor->Encloses(CurContext)) CommonAncestor = CommonAncestor->getParent(); UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc, SS.getWithLocInContext(Context), IdentLoc, Named, CommonAncestor); if (IsUsingDirectiveInToplevelContext(CurContext) && !SourceMgr.isInMainFile(SourceMgr.getExpansionLoc(IdentLoc))) { Diag(IdentLoc, diag::warn_using_directive_in_header); } PushUsingDirective(S, UDir); } else { Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange(); } if (UDir) ProcessDeclAttributeList(S, UDir, AttrList); return UDir; } void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) { // If the scope has an associated entity and the using directive is at // namespace or translation unit scope, add the UsingDirectiveDecl into // its lookup structure so qualified name lookup can find it. DeclContext *Ctx = S->getEntity(); if (Ctx && !Ctx->isFunctionOrMethod()) Ctx->addDecl(UDir); else // Otherwise, it is at block scope. The using-directives will affect lookup // only to the end of the scope. S->PushUsingDirective(UDir); } Decl *Sema::ActOnUsingDeclaration(Scope *S, AccessSpecifier AS, bool HasUsingKeyword, SourceLocation UsingLoc, CXXScopeSpec &SS, UnqualifiedId &Name, AttributeList *AttrList, bool HasTypenameKeyword, SourceLocation TypenameLoc) { assert(S->getFlags() & Scope::DeclScope && "Invalid Scope."); switch (Name.getKind()) { case UnqualifiedId::IK_ImplicitSelfParam: case UnqualifiedId::IK_Identifier: case UnqualifiedId::IK_OperatorFunctionId: case UnqualifiedId::IK_LiteralOperatorId: case UnqualifiedId::IK_ConversionFunctionId: break; case UnqualifiedId::IK_ConstructorName: case UnqualifiedId::IK_ConstructorTemplateId: // C++11 inheriting constructors. Diag(Name.getLocStart(), getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_using_decl_constructor : diag::err_using_decl_constructor) << SS.getRange(); if (getLangOpts().CPlusPlus11) break; return nullptr; case UnqualifiedId::IK_DestructorName: Diag(Name.getLocStart(), diag::err_using_decl_destructor) << SS.getRange(); return nullptr; case UnqualifiedId::IK_TemplateId: Diag(Name.getLocStart(), diag::err_using_decl_template_id) << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc); return nullptr; } DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name); DeclarationName TargetName = TargetNameInfo.getName(); if (!TargetName) return nullptr; // Warn about access declarations. if (!HasUsingKeyword) { Diag(Name.getLocStart(), getLangOpts().CPlusPlus11 ? diag::err_access_decl : diag::warn_access_decl_deprecated) << FixItHint::CreateInsertion(SS.getRange().getBegin(), "using "); } if (DiagnoseUnexpandedParameterPack(SS, UPPC_UsingDeclaration) || DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC_UsingDeclaration)) return nullptr; NamedDecl *UD = BuildUsingDeclaration(S, AS, UsingLoc, SS, TargetNameInfo, AttrList, /* IsInstantiation */ false, HasTypenameKeyword, TypenameLoc); if (UD) PushOnScopeChains(UD, S, /*AddToContext*/ false); return UD; } /// \brief Determine whether a using declaration considers the given /// declarations as "equivalent", e.g., if they are redeclarations of /// the same entity or are both typedefs of the same type. static bool IsEquivalentForUsingDecl(ASTContext &Context, NamedDecl *D1, NamedDecl *D2) { if (D1->getCanonicalDecl() == D2->getCanonicalDecl()) return true; if (TypedefNameDecl *TD1 = dyn_cast<TypedefNameDecl>(D1)) if (TypedefNameDecl *TD2 = dyn_cast<TypedefNameDecl>(D2)) return Context.hasSameType(TD1->getUnderlyingType(), TD2->getUnderlyingType()); return false; } /// Determines whether to create a using shadow decl for a particular /// decl, given the set of decls existing prior to this using lookup. bool Sema::CheckUsingShadowDecl(UsingDecl *Using, NamedDecl *Orig, const LookupResult &Previous, UsingShadowDecl *&PrevShadow) { // Diagnose finding a decl which is not from a base class of the // current class. We do this now because there are cases where this // function will silently decide not to build a shadow decl, which // will pre-empt further diagnostics. // // We don't need to do this in C++0x because we do the check once on // the qualifier. // // FIXME: diagnose the following if we care enough: // struct A { int foo; }; // struct B : A { using A::foo; }; // template <class T> struct C : A {}; // template <class T> struct D : C<T> { using B::foo; } // <--- // This is invalid (during instantiation) in C++03 because B::foo // resolves to the using decl in B, which is not a base class of D<T>. // We can't diagnose it immediately because C<T> is an unknown // specialization. The UsingShadowDecl in D<T> then points directly // to A::foo, which will look well-formed when we instantiate. // The right solution is to not collapse the shadow-decl chain. if (!getLangOpts().CPlusPlus11 && CurContext->isRecord()) { DeclContext *OrigDC = Orig->getDeclContext(); // Handle enums and anonymous structs. if (isa<EnumDecl>(OrigDC)) OrigDC = OrigDC->getParent(); CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC); while (OrigRec->isAnonymousStructOrUnion()) OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext()); if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) { if (OrigDC == CurContext) { Diag(Using->getLocation(), diag::err_using_decl_nested_name_specifier_is_current_class) << Using->getQualifierLoc().getSourceRange(); Diag(Orig->getLocation(), diag::note_using_decl_target); return true; } Diag(Using->getQualifierLoc().getBeginLoc(), diag::err_using_decl_nested_name_specifier_is_not_base_class) << Using->getQualifier() << cast<CXXRecordDecl>(CurContext) << Using->getQualifierLoc().getSourceRange(); Diag(Orig->getLocation(), diag::note_using_decl_target); return true; } } if (Previous.empty()) return false; NamedDecl *Target = Orig; if (isa<UsingShadowDecl>(Target)) Target = cast<UsingShadowDecl>(Target)->getTargetDecl(); // If the target happens to be one of the previous declarations, we // don't have a conflict. // // FIXME: but we might be increasing its access, in which case we // should redeclare it. NamedDecl *NonTag = nullptr, *Tag = nullptr; bool FoundEquivalentDecl = false; for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); I != E; ++I) { NamedDecl *D = (*I)->getUnderlyingDecl(); if (IsEquivalentForUsingDecl(Context, D, Target)) { if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(*I)) PrevShadow = Shadow; FoundEquivalentDecl = true; } if (isVisible(D)) (isa<TagDecl>(D) ? Tag : NonTag) = D; } if (FoundEquivalentDecl) return false; if (FunctionDecl *FD = Target->getAsFunction()) { NamedDecl *OldDecl = nullptr; switch (CheckOverload(nullptr, FD, Previous, OldDecl, /*IsForUsingDecl*/ true)) { case Ovl_Overload: return false; case Ovl_NonFunction: Diag(Using->getLocation(), diag::err_using_decl_conflict); break; // We found a decl with the exact signature. case Ovl_Match: // If we're in a record, we want to hide the target, so we // return true (without a diagnostic) to tell the caller not to // build a shadow decl. if (CurContext->isRecord()) return true; // If we're not in a record, this is an error. Diag(Using->getLocation(), diag::err_using_decl_conflict); break; } Diag(Target->getLocation(), diag::note_using_decl_target); Diag(OldDecl->getLocation(), diag::note_using_decl_conflict); return true; } // Target is not a function. if (isa<TagDecl>(Target)) { // No conflict between a tag and a non-tag. if (!Tag) return false; Diag(Using->getLocation(), diag::err_using_decl_conflict); Diag(Target->getLocation(), diag::note_using_decl_target); Diag(Tag->getLocation(), diag::note_using_decl_conflict); return true; } // No conflict between a tag and a non-tag. if (!NonTag) return false; Diag(Using->getLocation(), diag::err_using_decl_conflict); Diag(Target->getLocation(), diag::note_using_decl_target); Diag(NonTag->getLocation(), diag::note_using_decl_conflict); return true; } /// Builds a shadow declaration corresponding to a 'using' declaration. UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S, UsingDecl *UD, NamedDecl *Orig, UsingShadowDecl *PrevDecl) { // If we resolved to another shadow declaration, just coalesce them. NamedDecl *Target = Orig; if (isa<UsingShadowDecl>(Target)) { Target = cast<UsingShadowDecl>(Target)->getTargetDecl(); assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration"); } UsingShadowDecl *Shadow = UsingShadowDecl::Create(Context, CurContext, UD->getLocation(), UD, Target); UD->addShadowDecl(Shadow); Shadow->setAccess(UD->getAccess()); if (Orig->isInvalidDecl() || UD->isInvalidDecl()) Shadow->setInvalidDecl(); Shadow->setPreviousDecl(PrevDecl); if (S) PushOnScopeChains(Shadow, S); else CurContext->addDecl(Shadow); return Shadow; } /// Hides a using shadow declaration. This is required by the current /// using-decl implementation when a resolvable using declaration in a /// class is followed by a declaration which would hide or override /// one or more of the using decl's targets; for example: /// /// struct Base { void foo(int); }; /// struct Derived : Base { /// using Base::foo; /// void foo(int); /// }; /// /// The governing language is C++03 [namespace.udecl]p12: /// /// When a using-declaration brings names from a base class into a /// derived class scope, member functions in the derived class /// override and/or hide member functions with the same name and /// parameter types in a base class (rather than conflicting). /// /// There are two ways to implement this: /// (1) optimistically create shadow decls when they're not hidden /// by existing declarations, or /// (2) don't create any shadow decls (or at least don't make them /// visible) until we've fully parsed/instantiated the class. /// The problem with (1) is that we might have to retroactively remove /// a shadow decl, which requires several O(n) operations because the /// decl structures are (very reasonably) not designed for removal. /// (2) avoids this but is very fiddly and phase-dependent. void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) { if (Shadow->getDeclName().getNameKind() == DeclarationName::CXXConversionFunctionName) cast<CXXRecordDecl>(Shadow->getDeclContext())->removeConversion(Shadow); // Remove it from the DeclContext... Shadow->getDeclContext()->removeDecl(Shadow); // ...and the scope, if applicable... if (S) { S->RemoveDecl(Shadow); IdResolver.RemoveDecl(Shadow); } // ...and the using decl. Shadow->getUsingDecl()->removeShadowDecl(Shadow); // TODO: complain somehow if Shadow was used. It shouldn't // be possible for this to happen, because...? } /// Find the base specifier for a base class with the given type. static CXXBaseSpecifier *findDirectBaseWithType(CXXRecordDecl *Derived, QualType DesiredBase, bool &AnyDependentBases) { // Check whether the named type is a direct base class. CanQualType CanonicalDesiredBase = DesiredBase->getCanonicalTypeUnqualified(); for (auto &Base : Derived->bases()) { CanQualType BaseType = Base.getType()->getCanonicalTypeUnqualified(); if (CanonicalDesiredBase == BaseType) return &Base; if (BaseType->isDependentType()) AnyDependentBases = true; } return nullptr; } namespace { class UsingValidatorCCC : public CorrectionCandidateCallback { public: UsingValidatorCCC(bool HasTypenameKeyword, bool IsInstantiation, NestedNameSpecifier *NNS, CXXRecordDecl *RequireMemberOf) : HasTypenameKeyword(HasTypenameKeyword), IsInstantiation(IsInstantiation), OldNNS(NNS), RequireMemberOf(RequireMemberOf) {} bool ValidateCandidate(const TypoCorrection &Candidate) override { NamedDecl *ND = Candidate.getCorrectionDecl(); // Keywords are not valid here. if (!ND || isa<NamespaceDecl>(ND)) return false; // Completely unqualified names are invalid for a 'using' declaration. if (Candidate.WillReplaceSpecifier() && !Candidate.getCorrectionSpecifier()) return false; if (RequireMemberOf) { auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND); if (FoundRecord && FoundRecord->isInjectedClassName()) { // No-one ever wants a using-declaration to name an injected-class-name // of a base class, unless they're declaring an inheriting constructor. ASTContext &Ctx = ND->getASTContext(); if (!Ctx.getLangOpts().CPlusPlus11) return false; QualType FoundType = Ctx.getRecordType(FoundRecord); // Check that the injected-class-name is named as a member of its own // type; we don't want to suggest 'using Derived::Base;', since that // means something else. NestedNameSpecifier *Specifier = Candidate.WillReplaceSpecifier() ? Candidate.getCorrectionSpecifier() : OldNNS; if (!Specifier->getAsType() || !Ctx.hasSameType(QualType(Specifier->getAsType(), 0), FoundType)) return false; // Check that this inheriting constructor declaration actually names a // direct base class of the current class. bool AnyDependentBases = false; if (!findDirectBaseWithType(RequireMemberOf, Ctx.getRecordType(FoundRecord), AnyDependentBases) && !AnyDependentBases) return false; } else { auto *RD = dyn_cast<CXXRecordDecl>(ND->getDeclContext()); if (!RD || RequireMemberOf->isProvablyNotDerivedFrom(RD)) return false; // FIXME: Check that the base class member is accessible? } } else { auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND); if (FoundRecord && FoundRecord->isInjectedClassName()) return false; } if (isa<TypeDecl>(ND)) return HasTypenameKeyword || !IsInstantiation; return !HasTypenameKeyword; } private: bool HasTypenameKeyword; bool IsInstantiation; NestedNameSpecifier *OldNNS; CXXRecordDecl *RequireMemberOf; }; } // end anonymous namespace /// Builds a using declaration. /// /// \param IsInstantiation - Whether this call arises from an /// instantiation of an unresolved using declaration. We treat /// the lookup differently for these declarations. NamedDecl *Sema::BuildUsingDeclaration(Scope *S, AccessSpecifier AS, SourceLocation UsingLoc, CXXScopeSpec &SS, DeclarationNameInfo NameInfo, AttributeList *AttrList, bool IsInstantiation, bool HasTypenameKeyword, SourceLocation TypenameLoc) { assert(!SS.isInvalid() && "Invalid CXXScopeSpec."); SourceLocation IdentLoc = NameInfo.getLoc(); assert(IdentLoc.isValid() && "Invalid TargetName location."); // FIXME: We ignore attributes for now. if (SS.isEmpty()) { Diag(IdentLoc, diag::err_using_requires_qualname); return nullptr; } // Do the redeclaration lookup in the current scope. LookupResult Previous(*this, NameInfo, LookupUsingDeclName, ForRedeclaration); Previous.setHideTags(false); if (S) { LookupName(Previous, S); // It is really dumb that we have to do this. LookupResult::Filter F = Previous.makeFilter(); while (F.hasNext()) { NamedDecl *D = F.next(); if (!isDeclInScope(D, CurContext, S)) F.erase(); // If we found a local extern declaration that's not ordinarily visible, // and this declaration is being added to a non-block scope, ignore it. // We're only checking for scope conflicts here, not also for violations // of the linkage rules. else if (!CurContext->isFunctionOrMethod() && D->isLocalExternDecl() && !(D->getIdentifierNamespace() & Decl::IDNS_Ordinary)) F.erase(); } F.done(); } else { assert(IsInstantiation && "no scope in non-instantiation"); assert(CurContext->isRecord() && "scope not record in instantiation"); LookupQualifiedName(Previous, CurContext); } // Check for invalid redeclarations. if (CheckUsingDeclRedeclaration(UsingLoc, HasTypenameKeyword, SS, IdentLoc, Previous)) return nullptr; // Check for bad qualifiers. if (CheckUsingDeclQualifier(UsingLoc, SS, NameInfo, IdentLoc)) return nullptr; DeclContext *LookupContext = computeDeclContext(SS); NamedDecl *D; NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context); if (!LookupContext) { if (HasTypenameKeyword) { // FIXME: not all declaration name kinds are legal here D = UnresolvedUsingTypenameDecl::Create(Context, CurContext, UsingLoc, TypenameLoc, QualifierLoc, IdentLoc, NameInfo.getName()); } else { D = UnresolvedUsingValueDecl::Create(Context, CurContext, UsingLoc, QualifierLoc, NameInfo); } D->setAccess(AS); CurContext->addDecl(D); return D; } auto Build = [&](bool Invalid) { UsingDecl *UD = UsingDecl::Create(Context, CurContext, UsingLoc, QualifierLoc, NameInfo, HasTypenameKeyword); UD->setAccess(AS); CurContext->addDecl(UD); UD->setInvalidDecl(Invalid); return UD; }; auto BuildInvalid = [&]{ return Build(true); }; auto BuildValid = [&]{ return Build(false); }; if (RequireCompleteDeclContext(SS, LookupContext)) return BuildInvalid(); // Look up the target name. LookupResult R(*this, NameInfo, LookupOrdinaryName); // Unlike most lookups, we don't always want to hide tag // declarations: tag names are visible through the using declaration // even if hidden by ordinary names, *except* in a dependent context // where it's important for the sanity of two-phase lookup. if (!IsInstantiation) R.setHideTags(false); // For the purposes of this lookup, we have a base object type // equal to that of the current context. if (CurContext->isRecord()) { R.setBaseObjectType( Context.getTypeDeclType(cast<CXXRecordDecl>(CurContext))); } LookupQualifiedName(R, LookupContext); // Try to correct typos if possible. If constructor name lookup finds no // results, that means the named class has no explicit constructors, and we // suppressed declaring implicit ones (probably because it's dependent or // invalid). if (R.empty() && NameInfo.getName().getNameKind() != DeclarationName::CXXConstructorName) { if (TypoCorrection Corrected = CorrectTypo( R.getLookupNameInfo(), R.getLookupKind(), S, &SS, llvm::make_unique<UsingValidatorCCC>( HasTypenameKeyword, IsInstantiation, SS.getScopeRep(), dyn_cast<CXXRecordDecl>(CurContext)), CTK_ErrorRecovery)) { // We reject any correction for which ND would be NULL. NamedDecl *ND = Corrected.getCorrectionDecl(); // We reject candidates where DroppedSpecifier == true, hence the // literal '0' below. diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest) << NameInfo.getName() << LookupContext << 0 << SS.getRange()); // If we corrected to an inheriting constructor, handle it as one. auto *RD = dyn_cast<CXXRecordDecl>(ND); if (RD && RD->isInjectedClassName()) { // Fix up the information we'll use to build the using declaration. if (Corrected.WillReplaceSpecifier()) { NestedNameSpecifierLocBuilder Builder; Builder.MakeTrivial(Context, Corrected.getCorrectionSpecifier(), QualifierLoc.getSourceRange()); QualifierLoc = Builder.getWithLocInContext(Context); } NameInfo.setName(Context.DeclarationNames.getCXXConstructorName( Context.getCanonicalType(Context.getRecordType(RD)))); NameInfo.setNamedTypeInfo(nullptr); for (auto *Ctor : LookupConstructors(RD)) R.addDecl(Ctor); } else { // FIXME: Pick up all the declarations if we found an overloaded function. R.addDecl(ND); } } else { Diag(IdentLoc, diag::err_no_member) << NameInfo.getName() << LookupContext << SS.getRange(); return BuildInvalid(); } } if (R.isAmbiguous()) return BuildInvalid(); if (HasTypenameKeyword) { // If we asked for a typename and got a non-type decl, error out. if (!R.getAsSingle<TypeDecl>()) { Diag(IdentLoc, diag::err_using_typename_non_type); for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) Diag((*I)->getUnderlyingDecl()->getLocation(), diag::note_using_decl_target); return BuildInvalid(); } } else { // If we asked for a non-typename and we got a type, error out, // but only if this is an instantiation of an unresolved using // decl. Otherwise just silently find the type name. if (IsInstantiation && R.getAsSingle<TypeDecl>()) { Diag(IdentLoc, diag::err_using_dependent_value_is_type); Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target); return BuildInvalid(); } } // C++0x N2914 [namespace.udecl]p6: // A using-declaration shall not name a namespace. if (R.getAsSingle<NamespaceDecl>()) { Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace) << SS.getRange(); return BuildInvalid(); } UsingDecl *UD = BuildValid(); // The normal rules do not apply to inheriting constructor declarations. if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName) { // Suppress access diagnostics; the access check is instead performed at the // point of use for an inheriting constructor. R.suppressDiagnostics(); CheckInheritingConstructorUsingDecl(UD); return UD; } // Otherwise, look up the target name. for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { UsingShadowDecl *PrevDecl = nullptr; if (!CheckUsingShadowDecl(UD, *I, Previous, PrevDecl)) BuildUsingShadowDecl(S, UD, *I, PrevDecl); } return UD; } /// Additional checks for a using declaration referring to a constructor name. bool Sema::CheckInheritingConstructorUsingDecl(UsingDecl *UD) { assert(!UD->hasTypename() && "expecting a constructor name"); const Type *SourceType = UD->getQualifier()->getAsType(); assert(SourceType && "Using decl naming constructor doesn't have type in scope spec."); CXXRecordDecl *TargetClass = cast<CXXRecordDecl>(CurContext); // Check whether the named type is a direct base class. bool AnyDependentBases = false; auto *Base = findDirectBaseWithType(TargetClass, QualType(SourceType, 0), AnyDependentBases); if (!Base && !AnyDependentBases) { Diag(UD->getUsingLoc(), diag::err_using_decl_constructor_not_in_direct_base) << UD->getNameInfo().getSourceRange() << QualType(SourceType, 0) << TargetClass; UD->setInvalidDecl(); return true; } if (Base) Base->setInheritConstructors(); return false; } /// Checks that the given using declaration is not an invalid /// redeclaration. Note that this is checking only for the using decl /// itself, not for any ill-formedness among the UsingShadowDecls. bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc, bool HasTypenameKeyword, const CXXScopeSpec &SS, SourceLocation NameLoc, const LookupResult &Prev) { // C++03 [namespace.udecl]p8: // C++0x [namespace.udecl]p10: // A using-declaration is a declaration and can therefore be used // repeatedly where (and only where) multiple declarations are // allowed. // // That's in non-member contexts. if (!CurContext->getRedeclContext()->isRecord()) return false; NestedNameSpecifier *Qual = SS.getScopeRep(); for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) { NamedDecl *D = *I; bool DTypename; NestedNameSpecifier *DQual; if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) { DTypename = UD->hasTypename(); DQual = UD->getQualifier(); } else if (UnresolvedUsingValueDecl *UD = dyn_cast<UnresolvedUsingValueDecl>(D)) { DTypename = false; DQual = UD->getQualifier(); } else if (UnresolvedUsingTypenameDecl *UD = dyn_cast<UnresolvedUsingTypenameDecl>(D)) { DTypename = true; DQual = UD->getQualifier(); } else continue; // using decls differ if one says 'typename' and the other doesn't. // FIXME: non-dependent using decls? if (HasTypenameKeyword != DTypename) continue; // using decls differ if they name different scopes (but note that // template instantiation can cause this check to trigger when it // didn't before instantiation). if (Context.getCanonicalNestedNameSpecifier(Qual) != Context.getCanonicalNestedNameSpecifier(DQual)) continue; Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange(); Diag(D->getLocation(), diag::note_using_decl) << 1; return true; } return false; } /// Checks that the given nested-name qualifier used in a using decl /// in the current context is appropriately related to the current /// scope. If an error is found, diagnoses it and returns true. bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc, const CXXScopeSpec &SS, const DeclarationNameInfo &NameInfo, SourceLocation NameLoc) { DeclContext *NamedContext = computeDeclContext(SS); if (!CurContext->isRecord()) { // C++03 [namespace.udecl]p3: // C++0x [namespace.udecl]p8: // A using-declaration for a class member shall be a member-declaration. // If we weren't able to compute a valid scope, it must be a // dependent class scope. if (!NamedContext || NamedContext->isRecord()) { auto *RD = dyn_cast_or_null<CXXRecordDecl>(NamedContext); if (RD && RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), RD)) RD = nullptr; Diag(NameLoc, diag::err_using_decl_can_not_refer_to_class_member) << SS.getRange(); // If we have a complete, non-dependent source type, try to suggest a // way to get the same effect. if (!RD) return true; // Find what this using-declaration was referring to. LookupResult R(*this, NameInfo, LookupOrdinaryName); R.setHideTags(false); R.suppressDiagnostics(); LookupQualifiedName(R, RD); if (R.getAsSingle<TypeDecl>()) { if (getLangOpts().CPlusPlus11) { // Convert 'using X::Y;' to 'using Y = X::Y;'. Diag(SS.getBeginLoc(), diag::note_using_decl_class_member_workaround) << 0 // alias declaration << FixItHint::CreateInsertion(SS.getBeginLoc(), NameInfo.getName().getAsString() + " = "); } else { // Convert 'using X::Y;' to 'typedef X::Y Y;'. SourceLocation InsertLoc = getLocForEndOfToken(NameInfo.getLocEnd()); Diag(InsertLoc, diag::note_using_decl_class_member_workaround) << 1 // typedef declaration << FixItHint::CreateReplacement(UsingLoc, "typedef") << FixItHint::CreateInsertion( InsertLoc, " " + NameInfo.getName().getAsString()); } } else if (R.getAsSingle<VarDecl>()) { // Don't provide a fixit outside C++11 mode; we don't want to suggest // repeating the type of the static data member here. FixItHint FixIt; if (getLangOpts().CPlusPlus11) { // Convert 'using X::Y;' to 'auto &Y = X::Y;'. FixIt = FixItHint::CreateReplacement( UsingLoc, "auto &" + NameInfo.getName().getAsString() + " = "); } Diag(UsingLoc, diag::note_using_decl_class_member_workaround) << 2 // reference declaration << FixIt; } return true; } // Otherwise, everything is known to be fine. return false; } // The current scope is a record. // If the named context is dependent, we can't decide much. if (!NamedContext) { // FIXME: in C++0x, we can diagnose if we can prove that the // nested-name-specifier does not refer to a base class, which is // still possible in some cases. // Otherwise we have to conservatively report that things might be // okay. return false; } if (!NamedContext->isRecord()) { // Ideally this would point at the last name in the specifier, // but we don't have that level of source info. Diag(SS.getRange().getBegin(), diag::err_using_decl_nested_name_specifier_is_not_class) << SS.getScopeRep() << SS.getRange(); return true; } if (!NamedContext->isDependentContext() && RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), NamedContext)) return true; if (getLangOpts().CPlusPlus11) { // C++0x [namespace.udecl]p3: // In a using-declaration used as a member-declaration, the // nested-name-specifier shall name a base class of the class // being defined. if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom( cast<CXXRecordDecl>(NamedContext))) { if (CurContext == NamedContext) { Diag(NameLoc, diag::err_using_decl_nested_name_specifier_is_current_class) << SS.getRange(); return true; } Diag(SS.getRange().getBegin(), diag::err_using_decl_nested_name_specifier_is_not_base_class) << SS.getScopeRep() << cast<CXXRecordDecl>(CurContext) << SS.getRange(); return true; } return false; } // C++03 [namespace.udecl]p4: // A using-declaration used as a member-declaration shall refer // to a member of a base class of the class being defined [etc.]. // Salient point: SS doesn't have to name a base class as long as // lookup only finds members from base classes. Therefore we can // diagnose here only if we can prove that that can't happen, // i.e. if the class hierarchies provably don't intersect. // TODO: it would be nice if "definitely valid" results were cached // in the UsingDecl and UsingShadowDecl so that these checks didn't // need to be repeated. llvm::SmallPtrSet<const CXXRecordDecl *, 4> Bases; auto Collect = [&Bases](const CXXRecordDecl *Base) { Bases.insert(Base); return true; }; // Collect all bases. Return false if we find a dependent base. if (!cast<CXXRecordDecl>(CurContext)->forallBases(Collect)) return false; // Returns true if the base is dependent or is one of the accumulated base // classes. auto IsNotBase = [&Bases](const CXXRecordDecl *Base) { return !Bases.count(Base); }; // Return false if the class has a dependent base or if it or one // of its bases is present in the base set of the current context. if (Bases.count(cast<CXXRecordDecl>(NamedContext)) || !cast<CXXRecordDecl>(NamedContext)->forallBases(IsNotBase)) return false; Diag(SS.getRange().getBegin(), diag::err_using_decl_nested_name_specifier_is_not_base_class) << SS.getScopeRep() << cast<CXXRecordDecl>(CurContext) << SS.getRange(); return true; } Decl *Sema::ActOnAliasDeclaration(Scope *S, AccessSpecifier AS, MultiTemplateParamsArg TemplateParamLists, SourceLocation UsingLoc, UnqualifiedId &Name, AttributeList *AttrList, TypeResult Type, Decl *DeclFromDeclSpec) { // Skip up to the relevant declaration scope. while (S->isTemplateParamScope()) S = S->getParent(); assert((S->getFlags() & Scope::DeclScope) && "got alias-declaration outside of declaration scope"); if (Type.isInvalid()) return nullptr; bool Invalid = false; DeclarationNameInfo NameInfo = GetNameFromUnqualifiedId(Name); TypeSourceInfo *TInfo = nullptr; GetTypeFromParser(Type.get(), &TInfo); if (DiagnoseClassNameShadow(CurContext, NameInfo)) return nullptr; if (DiagnoseUnexpandedParameterPack(Name.StartLocation, TInfo, UPPC_DeclarationType)) { Invalid = true; TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy, TInfo->getTypeLoc().getBeginLoc()); } LookupResult Previous(*this, NameInfo, LookupOrdinaryName, ForRedeclaration); LookupName(Previous, S); // Warn about shadowing the name of a template parameter. if (Previous.isSingleResult() && Previous.getFoundDecl()->isTemplateParameter()) { DiagnoseTemplateParameterShadow(Name.StartLocation,Previous.getFoundDecl()); Previous.clear(); } assert(Name.Kind == UnqualifiedId::IK_Identifier && "name in alias declaration must be an identifier"); TypeAliasDecl *NewTD = TypeAliasDecl::Create(Context, CurContext, UsingLoc, Name.StartLocation, Name.Identifier, TInfo); NewTD->setAccess(AS); if (Invalid) NewTD->setInvalidDecl(); ProcessDeclAttributeList(S, NewTD, AttrList); CheckTypedefForVariablyModifiedType(S, NewTD); Invalid |= NewTD->isInvalidDecl(); bool Redeclaration = false; NamedDecl *NewND; if (TemplateParamLists.size()) { TypeAliasTemplateDecl *OldDecl = nullptr; TemplateParameterList *OldTemplateParams = nullptr; if (TemplateParamLists.size() != 1) { Diag(UsingLoc, diag::err_alias_template_extra_headers) << SourceRange(TemplateParamLists[1]->getTemplateLoc(), TemplateParamLists[TemplateParamLists.size()-1]->getRAngleLoc()); } TemplateParameterList *TemplateParams = TemplateParamLists[0]; // Only consider previous declarations in the same scope. FilterLookupForScope(Previous, CurContext, S, /*ConsiderLinkage*/false, /*ExplicitInstantiationOrSpecialization*/false); if (!Previous.empty()) { Redeclaration = true; OldDecl = Previous.getAsSingle<TypeAliasTemplateDecl>(); if (!OldDecl && !Invalid) { Diag(UsingLoc, diag::err_redefinition_different_kind) << Name.Identifier; NamedDecl *OldD = Previous.getRepresentativeDecl(); if (OldD->getLocation().isValid()) Diag(OldD->getLocation(), diag::note_previous_definition); Invalid = true; } if (!Invalid && OldDecl && !OldDecl->isInvalidDecl()) { if (TemplateParameterListsAreEqual(TemplateParams, OldDecl->getTemplateParameters(), /*Complain=*/true, TPL_TemplateMatch)) OldTemplateParams = OldDecl->getTemplateParameters(); else Invalid = true; TypeAliasDecl *OldTD = OldDecl->getTemplatedDecl(); if (!Invalid && !Context.hasSameType(OldTD->getUnderlyingType(), NewTD->getUnderlyingType())) { // FIXME: The C++0x standard does not clearly say this is ill-formed, // but we can't reasonably accept it. Diag(NewTD->getLocation(), diag::err_redefinition_different_typedef) << 2 << NewTD->getUnderlyingType() << OldTD->getUnderlyingType(); if (OldTD->getLocation().isValid()) Diag(OldTD->getLocation(), diag::note_previous_definition); Invalid = true; } } } // Merge any previous default template arguments into our parameters, // and check the parameter list. if (CheckTemplateParameterList(TemplateParams, OldTemplateParams, TPC_TypeAliasTemplate)) return nullptr; TypeAliasTemplateDecl *NewDecl = TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc, Name.Identifier, TemplateParams, NewTD); NewTD->setDescribedAliasTemplate(NewDecl); NewDecl->setAccess(AS); if (Invalid) NewDecl->setInvalidDecl(); else if (OldDecl) NewDecl->setPreviousDecl(OldDecl); NewND = NewDecl; } else { if (auto *TD = dyn_cast_or_null<TagDecl>(DeclFromDeclSpec)) { setTagNameForLinkagePurposes(TD, NewTD); handleTagNumbering(TD, S); } ActOnTypedefNameDecl(S, CurContext, NewTD, Previous, Redeclaration); NewND = NewTD; } if (!Redeclaration) PushOnScopeChains(NewND, S); ActOnDocumentableDecl(NewND); return NewND; } Decl *Sema::ActOnNamespaceAliasDef(Scope *S, SourceLocation NamespaceLoc, SourceLocation AliasLoc, IdentifierInfo *Alias, CXXScopeSpec &SS, SourceLocation IdentLoc, IdentifierInfo *Ident) { // Lookup the namespace name. LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName); LookupParsedName(R, S, &SS); if (R.isAmbiguous()) return nullptr; if (R.empty()) { if (!TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, Ident)) { Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange(); return nullptr; } } assert(!R.isAmbiguous() && !R.empty()); NamedDecl *ND = R.getFoundDecl(); // Check if we have a previous declaration with the same name. LookupResult PrevR(*this, Alias, AliasLoc, LookupOrdinaryName, ForRedeclaration); LookupName(PrevR, S); // Check we're not shadowing a template parameter. if (PrevR.isSingleResult() && PrevR.getFoundDecl()->isTemplateParameter()) { DiagnoseTemplateParameterShadow(AliasLoc, PrevR.getFoundDecl()); PrevR.clear(); } // Filter out any other lookup result from an enclosing scope. FilterLookupForScope(PrevR, CurContext, S, /*ConsiderLinkage*/false, /*AllowInlineNamespace*/false); // Find the previous declaration and check that we can redeclare it. NamespaceAliasDecl *Prev = nullptr; if (NamedDecl *PrevDecl = PrevR.getAsSingle<NamedDecl>()) { if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) { // We already have an alias with the same name that points to the same // namespace; check that it matches. if (AD->getNamespace()->Equals(getNamespaceDecl(ND))) { Prev = AD; } else if (isVisible(PrevDecl)) { Diag(AliasLoc, diag::err_redefinition_different_namespace_alias) << Alias; Diag(PrevDecl->getLocation(), diag::note_previous_namespace_alias) << AD->getNamespace(); return nullptr; } } else if (isVisible(PrevDecl)) { unsigned DiagID = isa<NamespaceDecl>(PrevDecl) ? diag::err_redefinition : diag::err_redefinition_different_kind; Diag(AliasLoc, DiagID) << Alias; Diag(PrevDecl->getLocation(), diag::note_previous_definition); return nullptr; } } // The use of a nested name specifier may trigger deprecation warnings. DiagnoseUseOfDecl(ND, IdentLoc); NamespaceAliasDecl *AliasDecl = NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc, Alias, SS.getWithLocInContext(Context), IdentLoc, ND); if (Prev) AliasDecl->setPreviousDecl(Prev); PushOnScopeChains(AliasDecl, S); return AliasDecl; } Sema::ImplicitExceptionSpecification Sema::ComputeDefaultedDefaultCtorExceptionSpec(SourceLocation Loc, CXXMethodDecl *MD) { CXXRecordDecl *ClassDecl = MD->getParent(); // C++ [except.spec]p14: // An implicitly declared special member function (Clause 12) shall have an // exception-specification. [...] ImplicitExceptionSpecification ExceptSpec(*this); if (ClassDecl->isInvalidDecl()) return ExceptSpec; // Direct base-class constructors. for (const auto &B : ClassDecl->bases()) { if (B.isVirtual()) // Handled below. continue; if (const RecordType *BaseType = B.getType()->getAs<RecordType>()) { CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl()); CXXConstructorDecl *Constructor = LookupDefaultConstructor(BaseClassDecl); // If this is a deleted function, add it anyway. This might be conformant // with the standard. This might not. I'm not sure. It might not matter. if (Constructor) ExceptSpec.CalledDecl(B.getLocStart(), Constructor); } } // Virtual base-class constructors. for (const auto &B : ClassDecl->vbases()) { if (const RecordType *BaseType = B.getType()->getAs<RecordType>()) { CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl()); CXXConstructorDecl *Constructor = LookupDefaultConstructor(BaseClassDecl); // If this is a deleted function, add it anyway. This might be conformant // with the standard. This might not. I'm not sure. It might not matter. if (Constructor) ExceptSpec.CalledDecl(B.getLocStart(), Constructor); } } // Field constructors. for (const auto *F : ClassDecl->fields()) { if (F->hasInClassInitializer()) { if (Expr *E = F->getInClassInitializer()) ExceptSpec.CalledExpr(E); } else if (const RecordType *RecordTy = Context.getBaseElementType(F->getType())->getAs<RecordType>()) { CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl()); CXXConstructorDecl *Constructor = LookupDefaultConstructor(FieldRecDecl); // If this is a deleted function, add it anyway. This might be conformant // with the standard. This might not. I'm not sure. It might not matter. // In particular, the problem is that this function never gets called. It // might just be ill-formed because this function attempts to refer to // a deleted function here. if (Constructor) ExceptSpec.CalledDecl(F->getLocation(), Constructor); } } return ExceptSpec; } Sema::ImplicitExceptionSpecification Sema::ComputeInheritingCtorExceptionSpec(CXXConstructorDecl *CD) { CXXRecordDecl *ClassDecl = CD->getParent(); // C++ [except.spec]p14: // An inheriting constructor [...] shall have an exception-specification. [...] ImplicitExceptionSpecification ExceptSpec(*this); if (ClassDecl->isInvalidDecl()) return ExceptSpec; // Inherited constructor. const CXXConstructorDecl *InheritedCD = CD->getInheritedConstructor(); const CXXRecordDecl *InheritedDecl = InheritedCD->getParent(); // FIXME: Copying or moving the parameters could add extra exceptions to the // set, as could the default arguments for the inherited constructor. This // will be addressed when we implement the resolution of core issue 1351. ExceptSpec.CalledDecl(CD->getLocStart(), InheritedCD); // Direct base-class constructors. for (const auto &B : ClassDecl->bases()) { if (B.isVirtual()) // Handled below. continue; if (const RecordType *BaseType = B.getType()->getAs<RecordType>()) { CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl()); if (BaseClassDecl == InheritedDecl) continue; CXXConstructorDecl *Constructor = LookupDefaultConstructor(BaseClassDecl); if (Constructor) ExceptSpec.CalledDecl(B.getLocStart(), Constructor); } } // Virtual base-class constructors. for (const auto &B : ClassDecl->vbases()) { if (const RecordType *BaseType = B.getType()->getAs<RecordType>()) { CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl()); if (BaseClassDecl == InheritedDecl) continue; CXXConstructorDecl *Constructor = LookupDefaultConstructor(BaseClassDecl); if (Constructor) ExceptSpec.CalledDecl(B.getLocStart(), Constructor); } } // Field constructors. for (const auto *F : ClassDecl->fields()) { if (F->hasInClassInitializer()) { if (Expr *E = F->getInClassInitializer()) ExceptSpec.CalledExpr(E); } else if (const RecordType *RecordTy = Context.getBaseElementType(F->getType())->getAs<RecordType>()) { CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl()); CXXConstructorDecl *Constructor = LookupDefaultConstructor(FieldRecDecl); if (Constructor) ExceptSpec.CalledDecl(F->getLocation(), Constructor); } } return ExceptSpec; } namespace { /// RAII object to register a special member as being currently declared. struct DeclaringSpecialMember { Sema &S; Sema::SpecialMemberDecl D; bool WasAlreadyBeingDeclared; DeclaringSpecialMember(Sema &S, CXXRecordDecl *RD, Sema::CXXSpecialMember CSM) : S(S), D(RD, CSM) { WasAlreadyBeingDeclared = !S.SpecialMembersBeingDeclared.insert(D).second; if (WasAlreadyBeingDeclared) // This almost never happens, but if it does, ensure that our cache // doesn't contain a stale result. S.SpecialMemberCache.clear(); // FIXME: Register a note to be produced if we encounter an error while // declaring the special member. } ~DeclaringSpecialMember() { if (!WasAlreadyBeingDeclared) S.SpecialMembersBeingDeclared.erase(D); } /// \brief Are we already trying to declare this special member? bool isAlreadyBeingDeclared() const { return WasAlreadyBeingDeclared; } }; } CXXConstructorDecl *Sema::DeclareImplicitDefaultConstructor( CXXRecordDecl *ClassDecl) { // C++ [class.ctor]p5: // A default constructor for a class X is a constructor of class X // that can be called without an argument. If there is no // user-declared constructor for class X, a default constructor is // implicitly declared. An implicitly-declared default constructor // is an inline public member of its class. assert(ClassDecl->needsImplicitDefaultConstructor() && "Should not build implicit default constructor!"); DeclaringSpecialMember DSM(*this, ClassDecl, CXXDefaultConstructor); if (DSM.isAlreadyBeingDeclared()) return nullptr; bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, CXXDefaultConstructor, false); // Create the actual constructor declaration. CanQualType ClassType = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl)); SourceLocation ClassLoc = ClassDecl->getLocation(); DeclarationName Name = Context.DeclarationNames.getCXXConstructorName(ClassType); DeclarationNameInfo NameInfo(Name, ClassLoc); CXXConstructorDecl *DefaultCon = CXXConstructorDecl::Create( Context, ClassDecl, ClassLoc, NameInfo, /*Type*/QualType(), /*TInfo=*/nullptr, /*isExplicit=*/false, /*isInline=*/true, /*isImplicitlyDeclared=*/true, Constexpr); DefaultCon->setAccess(AS_public); DefaultCon->setDefaulted(); if (getLangOpts().CUDA) { inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDefaultConstructor, DefaultCon, /* ConstRHS */ false, /* Diagnose */ false); } // Build an exception specification pointing back at this constructor. FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, DefaultCon); DefaultCon->setType(Context.getFunctionType(Context.VoidTy, None, EPI)); // We don't need to use SpecialMemberIsTrivial here; triviality for default // constructors is easy to compute. DefaultCon->setTrivial(ClassDecl->hasTrivialDefaultConstructor()); if (ShouldDeleteSpecialMember(DefaultCon, CXXDefaultConstructor)) SetDeclDeleted(DefaultCon, ClassLoc); // Note that we have declared this constructor. ++ASTContext::NumImplicitDefaultConstructorsDeclared; if (Scope *S = getScopeForContext(ClassDecl)) PushOnScopeChains(DefaultCon, S, false); ClassDecl->addDecl(DefaultCon); return DefaultCon; } void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation, CXXConstructorDecl *Constructor) { assert((Constructor->isDefaulted() && Constructor->isDefaultConstructor() && !Constructor->doesThisDeclarationHaveABody() && !Constructor->isDeleted()) && "DefineImplicitDefaultConstructor - call it for implicit default ctor"); CXXRecordDecl *ClassDecl = Constructor->getParent(); assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor"); SynthesizedFunctionScope Scope(*this, Constructor); DiagnosticErrorTrap Trap(Diags); if (SetCtorInitializers(Constructor, /*AnyErrors=*/false) || Trap.hasErrorOccurred()) { Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXDefaultConstructor << Context.getTagDeclType(ClassDecl); Constructor->setInvalidDecl(); return; } // The exception specification is needed because we are defining the // function. ResolveExceptionSpec(CurrentLocation, Constructor->getType()->castAs<FunctionProtoType>()); SourceLocation Loc = Constructor->getLocEnd().isValid() ? Constructor->getLocEnd() : Constructor->getLocation(); Constructor->setBody(new (Context) CompoundStmt(Loc)); Constructor->markUsed(Context); MarkVTableUsed(CurrentLocation, ClassDecl); if (ASTMutationListener *L = getASTMutationListener()) { L->CompletedImplicitDefinition(Constructor); } DiagnoseUninitializedFields(*this, Constructor); } void Sema::ActOnFinishDelayedMemberInitializers(Decl *D) { // Perform any delayed checks on exception specifications. CheckDelayedMemberExceptionSpecs(); } namespace { /// Information on inheriting constructors to declare. class InheritingConstructorInfo { public: InheritingConstructorInfo(Sema &SemaRef, CXXRecordDecl *Derived) : SemaRef(SemaRef), Derived(Derived) { // Mark the constructors that we already have in the derived class. // // C++11 [class.inhctor]p3: [...] a constructor is implicitly declared [...] // unless there is a user-declared constructor with the same signature in // the class where the using-declaration appears. visitAll(Derived, &InheritingConstructorInfo::noteDeclaredInDerived); } void inheritAll(CXXRecordDecl *RD) { visitAll(RD, &InheritingConstructorInfo::inherit); } private: /// Information about an inheriting constructor. struct InheritingConstructor { InheritingConstructor() : DeclaredInDerived(false), BaseCtor(nullptr), DerivedCtor(nullptr) {} /// If \c true, a constructor with this signature is already declared /// in the derived class. bool DeclaredInDerived; /// The constructor which is inherited. const CXXConstructorDecl *BaseCtor; /// The derived constructor we declared. CXXConstructorDecl *DerivedCtor; }; /// Inheriting constructors with a given canonical type. There can be at /// most one such non-template constructor, and any number of templated /// constructors. struct InheritingConstructorsForType { InheritingConstructor NonTemplate; SmallVector<std::pair<TemplateParameterList *, InheritingConstructor>, 4> Templates; InheritingConstructor &getEntry(Sema &S, const CXXConstructorDecl *Ctor) { if (FunctionTemplateDecl *FTD = Ctor->getDescribedFunctionTemplate()) { TemplateParameterList *ParamList = FTD->getTemplateParameters(); for (unsigned I = 0, N = Templates.size(); I != N; ++I) if (S.TemplateParameterListsAreEqual(ParamList, Templates[I].first, false, S.TPL_TemplateMatch)) return Templates[I].second; Templates.push_back(std::make_pair(ParamList, InheritingConstructor())); return Templates.back().second; } return NonTemplate; } }; /// Get or create the inheriting constructor record for a constructor. InheritingConstructor &getEntry(const CXXConstructorDecl *Ctor, QualType CtorType) { return Map[CtorType.getCanonicalType()->castAs<FunctionProtoType>()] .getEntry(SemaRef, Ctor); } typedef void (InheritingConstructorInfo::*VisitFn)(const CXXConstructorDecl*); /// Process all constructors for a class. void visitAll(const CXXRecordDecl *RD, VisitFn Callback) { for (const auto *Ctor : RD->ctors()) (this->*Callback)(Ctor); for (CXXRecordDecl::specific_decl_iterator<FunctionTemplateDecl> I(RD->decls_begin()), E(RD->decls_end()); I != E; ++I) { const FunctionDecl *FD = (*I)->getTemplatedDecl(); if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) (this->*Callback)(CD); } } /// Note that a constructor (or constructor template) was declared in Derived. void noteDeclaredInDerived(const CXXConstructorDecl *Ctor) { getEntry(Ctor, Ctor->getType()).DeclaredInDerived = true; } /// Inherit a single constructor. void inherit(const CXXConstructorDecl *Ctor) { const FunctionProtoType *CtorType = Ctor->getType()->castAs<FunctionProtoType>(); ArrayRef<QualType> ArgTypes = CtorType->getParamTypes(); FunctionProtoType::ExtProtoInfo EPI = CtorType->getExtProtoInfo(); SourceLocation UsingLoc = getUsingLoc(Ctor->getParent()); // Core issue (no number yet): the ellipsis is always discarded. if (EPI.Variadic) { SemaRef.Diag(UsingLoc, diag::warn_using_decl_constructor_ellipsis); SemaRef.Diag(Ctor->getLocation(), diag::note_using_decl_constructor_ellipsis); EPI.Variadic = false; } // Declare a constructor for each number of parameters. // // C++11 [class.inhctor]p1: // The candidate set of inherited constructors from the class X named in // the using-declaration consists of [... modulo defects ...] for each // constructor or constructor template of X, the set of constructors or // constructor templates that results from omitting any ellipsis parameter // specification and successively omitting parameters with a default // argument from the end of the parameter-type-list unsigned MinParams = minParamsToInherit(Ctor); unsigned Params = Ctor->getNumParams(); if (Params >= MinParams) { do declareCtor(UsingLoc, Ctor, SemaRef.Context.getFunctionType( Ctor->getReturnType(), ArgTypes.slice(0, Params), EPI)); while (Params > MinParams && Ctor->getParamDecl(--Params)->hasDefaultArg()); } } /// Find the using-declaration which specified that we should inherit the /// constructors of \p Base. SourceLocation getUsingLoc(const CXXRecordDecl *Base) { // No fancy lookup required; just look for the base constructor name // directly within the derived class. ASTContext &Context = SemaRef.Context; DeclarationName Name = Context.DeclarationNames.getCXXConstructorName( Context.getCanonicalType(Context.getRecordType(Base))); DeclContext::lookup_result Decls = Derived->lookup(Name); return Decls.empty() ? Derived->getLocation() : Decls[0]->getLocation(); } unsigned minParamsToInherit(const CXXConstructorDecl *Ctor) { // C++11 [class.inhctor]p3: // [F]or each constructor template in the candidate set of inherited // constructors, a constructor template is implicitly declared if (Ctor->getDescribedFunctionTemplate()) return 0; // For each non-template constructor in the candidate set of inherited // constructors other than a constructor having no parameters or a // copy/move constructor having a single parameter, a constructor is // implicitly declared [...] if (Ctor->getNumParams() == 0) return 1; if (Ctor->isCopyOrMoveConstructor()) return 2; // Per discussion on core reflector, never inherit a constructor which // would become a default, copy, or move constructor of Derived either. const ParmVarDecl *PD = Ctor->getParamDecl(0); const ReferenceType *RT = PD->getType()->getAs<ReferenceType>(); return (RT && RT->getPointeeCXXRecordDecl() == Derived) ? 2 : 1; } /// Declare a single inheriting constructor, inheriting the specified /// constructor, with the given type. void declareCtor(SourceLocation UsingLoc, const CXXConstructorDecl *BaseCtor, QualType DerivedType) { InheritingConstructor &Entry = getEntry(BaseCtor, DerivedType); // C++11 [class.inhctor]p3: // ... a constructor is implicitly declared with the same constructor // characteristics unless there is a user-declared constructor with // the same signature in the class where the using-declaration appears if (Entry.DeclaredInDerived) return; // C++11 [class.inhctor]p7: // If two using-declarations declare inheriting constructors with the // same signature, the program is ill-formed if (Entry.DerivedCtor) { if (BaseCtor->getParent() != Entry.BaseCtor->getParent()) { // Only diagnose this once per constructor. if (Entry.DerivedCtor->isInvalidDecl()) return; Entry.DerivedCtor->setInvalidDecl(); SemaRef.Diag(UsingLoc, diag::err_using_decl_constructor_conflict); SemaRef.Diag(BaseCtor->getLocation(), diag::note_using_decl_constructor_conflict_current_ctor); SemaRef.Diag(Entry.BaseCtor->getLocation(), diag::note_using_decl_constructor_conflict_previous_ctor); SemaRef.Diag(Entry.DerivedCtor->getLocation(), diag::note_using_decl_constructor_conflict_previous_using); } else { // Core issue (no number): if the same inheriting constructor is // produced by multiple base class constructors from the same base // class, the inheriting constructor is defined as deleted. SemaRef.SetDeclDeleted(Entry.DerivedCtor, UsingLoc); } return; } ASTContext &Context = SemaRef.Context; DeclarationName Name = Context.DeclarationNames.getCXXConstructorName( Context.getCanonicalType(Context.getRecordType(Derived))); DeclarationNameInfo NameInfo(Name, UsingLoc); TemplateParameterList *TemplateParams = nullptr; if (const FunctionTemplateDecl *FTD = BaseCtor->getDescribedFunctionTemplate()) { TemplateParams = FTD->getTemplateParameters(); // We're reusing template parameters from a different DeclContext. This // is questionable at best, but works out because the template depth in // both places is guaranteed to be 0. // FIXME: Rebuild the template parameters in the new context, and // transform the function type to refer to them. } // Build type source info pointing at the using-declaration. This is // required by template instantiation. TypeSourceInfo *TInfo = Context.getTrivialTypeSourceInfo(DerivedType, UsingLoc); FunctionProtoTypeLoc ProtoLoc = TInfo->getTypeLoc().IgnoreParens().castAs<FunctionProtoTypeLoc>(); CXXConstructorDecl *DerivedCtor = CXXConstructorDecl::Create( Context, Derived, UsingLoc, NameInfo, DerivedType, TInfo, BaseCtor->isExplicit(), /*Inline=*/true, /*ImplicitlyDeclared=*/true, /*Constexpr=*/BaseCtor->isConstexpr()); // Build an unevaluated exception specification for this constructor. const FunctionProtoType *FPT = DerivedType->castAs<FunctionProtoType>(); FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); EPI.ExceptionSpec.Type = EST_Unevaluated; EPI.ExceptionSpec.SourceDecl = DerivedCtor; DerivedCtor->setType(Context.getFunctionType(FPT->getReturnType(), FPT->getParamTypes(), EPI)); // Build the parameter declarations. SmallVector<ParmVarDecl *, 16> ParamDecls; for (unsigned I = 0, N = FPT->getNumParams(); I != N; ++I) { TypeSourceInfo *TInfo = Context.getTrivialTypeSourceInfo(FPT->getParamType(I), UsingLoc); ParmVarDecl *PD = ParmVarDecl::Create( Context, DerivedCtor, UsingLoc, UsingLoc, /*IdentifierInfo=*/nullptr, FPT->getParamType(I), TInfo, SC_None, /*DefaultArg=*/nullptr); PD->setScopeInfo(0, I); PD->setImplicit(); ParamDecls.push_back(PD); ProtoLoc.setParam(I, PD); } // Set up the new constructor. DerivedCtor->setAccess(BaseCtor->getAccess()); DerivedCtor->setParams(ParamDecls); DerivedCtor->setInheritedConstructor(BaseCtor); if (BaseCtor->isDeleted()) SemaRef.SetDeclDeleted(DerivedCtor, UsingLoc); // If this is a constructor template, build the template declaration. if (TemplateParams) { FunctionTemplateDecl *DerivedTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Derived, UsingLoc, Name, TemplateParams, DerivedCtor); DerivedTemplate->setAccess(BaseCtor->getAccess()); DerivedCtor->setDescribedFunctionTemplate(DerivedTemplate); Derived->addDecl(DerivedTemplate); } else { Derived->addDecl(DerivedCtor); } Entry.BaseCtor = BaseCtor; Entry.DerivedCtor = DerivedCtor; } Sema &SemaRef; CXXRecordDecl *Derived; typedef llvm::DenseMap<const Type *, InheritingConstructorsForType> MapType; MapType Map; }; } void Sema::DeclareInheritingConstructors(CXXRecordDecl *ClassDecl) { // Defer declaring the inheriting constructors until the class is // instantiated. if (ClassDecl->isDependentContext()) return; // Find base classes from which we might inherit constructors. SmallVector<CXXRecordDecl*, 4> InheritedBases; for (const auto &BaseIt : ClassDecl->bases()) if (BaseIt.getInheritConstructors()) InheritedBases.push_back(BaseIt.getType()->getAsCXXRecordDecl()); // Go no further if we're not inheriting any constructors. if (InheritedBases.empty()) return; // Declare the inherited constructors. InheritingConstructorInfo ICI(*this, ClassDecl); for (unsigned I = 0, N = InheritedBases.size(); I != N; ++I) ICI.inheritAll(InheritedBases[I]); } void Sema::DefineInheritingConstructor(SourceLocation CurrentLocation, CXXConstructorDecl *Constructor) { CXXRecordDecl *ClassDecl = Constructor->getParent(); assert(Constructor->getInheritedConstructor() && !Constructor->doesThisDeclarationHaveABody() && !Constructor->isDeleted()); SynthesizedFunctionScope Scope(*this, Constructor); DiagnosticErrorTrap Trap(Diags); if (SetCtorInitializers(Constructor, /*AnyErrors=*/false) || Trap.hasErrorOccurred()) { Diag(CurrentLocation, diag::note_inhctor_synthesized_at) << Context.getTagDeclType(ClassDecl); Constructor->setInvalidDecl(); return; } SourceLocation Loc = Constructor->getLocation(); Constructor->setBody(new (Context) CompoundStmt(Loc)); Constructor->markUsed(Context); MarkVTableUsed(CurrentLocation, ClassDecl); if (ASTMutationListener *L = getASTMutationListener()) { L->CompletedImplicitDefinition(Constructor); } } Sema::ImplicitExceptionSpecification Sema::ComputeDefaultedDtorExceptionSpec(CXXMethodDecl *MD) { CXXRecordDecl *ClassDecl = MD->getParent(); // C++ [except.spec]p14: // An implicitly declared special member function (Clause 12) shall have // an exception-specification. ImplicitExceptionSpecification ExceptSpec(*this); if (ClassDecl->isInvalidDecl()) return ExceptSpec; // Direct base-class destructors. for (const auto &B : ClassDecl->bases()) { if (B.isVirtual()) // Handled below. continue; if (const RecordType *BaseType = B.getType()->getAs<RecordType>()) ExceptSpec.CalledDecl(B.getLocStart(), LookupDestructor(cast<CXXRecordDecl>(BaseType->getDecl()))); } // Virtual base-class destructors. for (const auto &B : ClassDecl->vbases()) { if (const RecordType *BaseType = B.getType()->getAs<RecordType>()) ExceptSpec.CalledDecl(B.getLocStart(), LookupDestructor(cast<CXXRecordDecl>(BaseType->getDecl()))); } // Field destructors. for (const auto *F : ClassDecl->fields()) { if (const RecordType *RecordTy = Context.getBaseElementType(F->getType())->getAs<RecordType>()) ExceptSpec.CalledDecl(F->getLocation(), LookupDestructor(cast<CXXRecordDecl>(RecordTy->getDecl()))); } return ExceptSpec; } CXXDestructorDecl *Sema::DeclareImplicitDestructor(CXXRecordDecl *ClassDecl) { // C++ [class.dtor]p2: // If a class has no user-declared destructor, a destructor is // declared implicitly. An implicitly-declared destructor is an // inline public member of its class. assert(ClassDecl->needsImplicitDestructor()); DeclaringSpecialMember DSM(*this, ClassDecl, CXXDestructor); if (DSM.isAlreadyBeingDeclared()) return nullptr; // Create the actual destructor declaration. CanQualType ClassType = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl)); SourceLocation ClassLoc = ClassDecl->getLocation(); DeclarationName Name = Context.DeclarationNames.getCXXDestructorName(ClassType); DeclarationNameInfo NameInfo(Name, ClassLoc); CXXDestructorDecl *Destructor = CXXDestructorDecl::Create(Context, ClassDecl, ClassLoc, NameInfo, QualType(), nullptr, /*isInline=*/true, /*isImplicitlyDeclared=*/true); Destructor->setAccess(AS_public); Destructor->setDefaulted(); if (getLangOpts().CUDA) { inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDestructor, Destructor, /* ConstRHS */ false, /* Diagnose */ false); } // Build an exception specification pointing back at this destructor. FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, Destructor); Destructor->setType(Context.getFunctionType(Context.VoidTy, None, EPI)); AddOverriddenMethods(ClassDecl, Destructor); // We don't need to use SpecialMemberIsTrivial here; triviality for // destructors is easy to compute. Destructor->setTrivial(ClassDecl->hasTrivialDestructor()); if (ShouldDeleteSpecialMember(Destructor, CXXDestructor)) SetDeclDeleted(Destructor, ClassLoc); // Note that we have declared this destructor. ++ASTContext::NumImplicitDestructorsDeclared; // Introduce this destructor into its scope. if (Scope *S = getScopeForContext(ClassDecl)) PushOnScopeChains(Destructor, S, false); ClassDecl->addDecl(Destructor); return Destructor; } void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation, CXXDestructorDecl *Destructor) { assert((Destructor->isDefaulted() && !Destructor->doesThisDeclarationHaveABody() && !Destructor->isDeleted()) && "DefineImplicitDestructor - call it for implicit default dtor"); CXXRecordDecl *ClassDecl = Destructor->getParent(); assert(ClassDecl && "DefineImplicitDestructor - invalid destructor"); if (Destructor->isInvalidDecl()) return; SynthesizedFunctionScope Scope(*this, Destructor); DiagnosticErrorTrap Trap(Diags); MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(), Destructor->getParent()); if (CheckDestructor(Destructor) || Trap.hasErrorOccurred()) { Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXDestructor << Context.getTagDeclType(ClassDecl); Destructor->setInvalidDecl(); return; } // The exception specification is needed because we are defining the // function. ResolveExceptionSpec(CurrentLocation, Destructor->getType()->castAs<FunctionProtoType>()); SourceLocation Loc = Destructor->getLocEnd().isValid() ? Destructor->getLocEnd() : Destructor->getLocation(); Destructor->setBody(new (Context) CompoundStmt(Loc)); Destructor->markUsed(Context); MarkVTableUsed(CurrentLocation, ClassDecl); if (ASTMutationListener *L = getASTMutationListener()) { L->CompletedImplicitDefinition(Destructor); } } /// \brief Perform any semantic analysis which needs to be delayed until all /// pending class member declarations have been parsed. void Sema::ActOnFinishCXXMemberDecls() { // If the context is an invalid C++ class, just suppress these checks. if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(CurContext)) { if (Record->isInvalidDecl()) { DelayedDefaultedMemberExceptionSpecs.clear(); DelayedExceptionSpecChecks.clear(); return; } } } static void getDefaultArgExprsForConstructors(Sema &S, CXXRecordDecl *Class) { // Don't do anything for template patterns. if (Class->getDescribedClassTemplate()) return; for (Decl *Member : Class->decls()) { auto *CD = dyn_cast<CXXConstructorDecl>(Member); if (!CD) { // Recurse on nested classes. if (auto *NestedRD = dyn_cast<CXXRecordDecl>(Member)) getDefaultArgExprsForConstructors(S, NestedRD); continue; } else if (!CD->isDefaultConstructor() || !CD->hasAttr<DLLExportAttr>()) { continue; } for (unsigned I = 0, E = CD->getNumParams(); I != E; ++I) { // Skip any default arguments that we've already instantiated. if (S.Context.getDefaultArgExprForConstructor(CD, I)) continue; Expr *DefaultArg = S.BuildCXXDefaultArgExpr(Class->getLocation(), CD, CD->getParamDecl(I)).get(); S.DiscardCleanupsInEvaluationContext(); S.Context.addDefaultArgExprForConstructor(CD, I, DefaultArg); } } } void Sema::ActOnFinishCXXNonNestedClass(Decl *D) { auto *RD = dyn_cast<CXXRecordDecl>(D); // Default constructors that are annotated with __declspec(dllexport) which // have default arguments or don't use the standard calling convention are // wrapped with a thunk called the default constructor closure. if (RD && Context.getTargetInfo().getCXXABI().isMicrosoft()) getDefaultArgExprsForConstructors(*this, RD); if (!DelayedDllExportClasses.empty()) { // Calling ReferenceDllExportedMethods might cause the current function to // be called again, so use a local copy of DelayedDllExportClasses. SmallVector<CXXRecordDecl *, 4> WorkList; std::swap(DelayedDllExportClasses, WorkList); for (CXXRecordDecl *Class : WorkList) ReferenceDllExportedMethods(*this, Class); } } void Sema::AdjustDestructorExceptionSpec(CXXRecordDecl *ClassDecl, CXXDestructorDecl *Destructor) { assert(getLangOpts().CPlusPlus11 && "adjusting dtor exception specs was introduced in c++11"); // C++11 [class.dtor]p3: // A declaration of a destructor that does not have an exception- // specification is implicitly considered to have the same exception- // specification as an implicit declaration. const FunctionProtoType *DtorType = Destructor->getType()-> getAs<FunctionProtoType>(); if (DtorType->hasExceptionSpec()) return; // Replace the destructor's type, building off the existing one. Fortunately, // the only thing of interest in the destructor type is its extended info. // The return and arguments are fixed. FunctionProtoType::ExtProtoInfo EPI = DtorType->getExtProtoInfo(); EPI.ExceptionSpec.Type = EST_Unevaluated; EPI.ExceptionSpec.SourceDecl = Destructor; Destructor->setType(Context.getFunctionType(Context.VoidTy, None, EPI)); // FIXME: If the destructor has a body that could throw, and the newly created // spec doesn't allow exceptions, we should emit a warning, because this // change in behavior can break conforming C++03 programs at runtime. // However, we don't have a body or an exception specification yet, so it // needs to be done somewhere else. } namespace { /// \brief An abstract base class for all helper classes used in building the // copy/move operators. These classes serve as factory functions and help us // avoid using the same Expr* in the AST twice. class ExprBuilder { ExprBuilder(const ExprBuilder&) = delete; ExprBuilder &operator=(const ExprBuilder&) = delete; protected: static Expr *assertNotNull(Expr *E) { assert(E && "Expression construction must not fail."); return E; } public: ExprBuilder() {} virtual ~ExprBuilder() {} virtual Expr *build(Sema &S, SourceLocation Loc) const = 0; }; class RefBuilder: public ExprBuilder { VarDecl *Var; QualType VarType; public: Expr *build(Sema &S, SourceLocation Loc) const override { return assertNotNull(S.BuildDeclRefExpr(Var, VarType, VK_LValue, Loc).get()); } RefBuilder(VarDecl *Var, QualType VarType) : Var(Var), VarType(VarType) {} }; class ThisBuilder: public ExprBuilder { public: Expr *build(Sema &S, SourceLocation Loc) const override { return assertNotNull(S.ActOnCXXThis(Loc).getAs<Expr>()); } }; class CastBuilder: public ExprBuilder { const ExprBuilder &Builder; QualType Type; ExprValueKind Kind; const CXXCastPath &Path; public: Expr *build(Sema &S, SourceLocation Loc) const override { return assertNotNull(S.ImpCastExprToType(Builder.build(S, Loc), Type, CK_UncheckedDerivedToBase, Kind, &Path).get()); } CastBuilder(const ExprBuilder &Builder, QualType Type, ExprValueKind Kind, const CXXCastPath &Path) : Builder(Builder), Type(Type), Kind(Kind), Path(Path) {} }; class DerefBuilder: public ExprBuilder { const ExprBuilder &Builder; public: Expr *build(Sema &S, SourceLocation Loc) const override { return assertNotNull( S.CreateBuiltinUnaryOp(Loc, UO_Deref, Builder.build(S, Loc)).get()); } DerefBuilder(const ExprBuilder &Builder) : Builder(Builder) {} }; class MemberBuilder: public ExprBuilder { const ExprBuilder &Builder; QualType Type; CXXScopeSpec SS; bool IsArrow; LookupResult &MemberLookup; public: Expr *build(Sema &S, SourceLocation Loc) const override { return assertNotNull(S.BuildMemberReferenceExpr( Builder.build(S, Loc), Type, Loc, IsArrow, SS, SourceLocation(), nullptr, MemberLookup, nullptr, nullptr).get()); } MemberBuilder(const ExprBuilder &Builder, QualType Type, bool IsArrow, LookupResult &MemberLookup) : Builder(Builder), Type(Type), IsArrow(IsArrow), MemberLookup(MemberLookup) {} }; class MoveCastBuilder: public ExprBuilder { const ExprBuilder &Builder; public: Expr *build(Sema &S, SourceLocation Loc) const override { return assertNotNull(CastForMoving(S, Builder.build(S, Loc))); } MoveCastBuilder(const ExprBuilder &Builder) : Builder(Builder) {} }; class LvalueConvBuilder: public ExprBuilder { const ExprBuilder &Builder; public: Expr *build(Sema &S, SourceLocation Loc) const override { return assertNotNull( S.DefaultLvalueConversion(Builder.build(S, Loc)).get()); } LvalueConvBuilder(const ExprBuilder &Builder) : Builder(Builder) {} }; class SubscriptBuilder: public ExprBuilder { const ExprBuilder &Base; const ExprBuilder &Index; public: Expr *build(Sema &S, SourceLocation Loc) const override { return assertNotNull(S.CreateBuiltinArraySubscriptExpr( Base.build(S, Loc), Loc, Index.build(S, Loc), Loc).get()); } SubscriptBuilder(const ExprBuilder &Base, const ExprBuilder &Index) : Base(Base), Index(Index) {} }; } // end anonymous namespace /// When generating a defaulted copy or move assignment operator, if a field /// should be copied with __builtin_memcpy rather than via explicit assignments, /// do so. This optimization only applies for arrays of scalars, and for arrays /// of class type where the selected copy/move-assignment operator is trivial. static StmtResult buildMemcpyForAssignmentOp(Sema &S, SourceLocation Loc, QualType T, const ExprBuilder &ToB, const ExprBuilder &FromB) { // Compute the size of the memory buffer to be copied. QualType SizeType = S.Context.getSizeType(); llvm::APInt Size(S.Context.getTypeSize(SizeType), S.Context.getTypeSizeInChars(T).getQuantity()); // Take the address of the field references for "from" and "to". We // directly construct UnaryOperators here because semantic analysis // does not permit us to take the address of an xvalue. Expr *From = FromB.build(S, Loc); From = new (S.Context) UnaryOperator(From, UO_AddrOf, S.Context.getPointerType(From->getType()), VK_RValue, OK_Ordinary, Loc); Expr *To = ToB.build(S, Loc); To = new (S.Context) UnaryOperator(To, UO_AddrOf, S.Context.getPointerType(To->getType()), VK_RValue, OK_Ordinary, Loc); const Type *E = T->getBaseElementTypeUnsafe(); bool NeedsCollectableMemCpy = E->isRecordType() && E->getAs<RecordType>()->getDecl()->hasObjectMember(); // Create a reference to the __builtin_objc_memmove_collectable function StringRef MemCpyName = NeedsCollectableMemCpy ? "__builtin_objc_memmove_collectable" : "__builtin_memcpy"; LookupResult R(S, &S.Context.Idents.get(MemCpyName), Loc, Sema::LookupOrdinaryName); S.LookupName(R, S.TUScope, true); FunctionDecl *MemCpy = R.getAsSingle<FunctionDecl>(); if (!MemCpy) // Something went horribly wrong earlier, and we will have complained // about it. return StmtError(); ExprResult MemCpyRef = S.BuildDeclRefExpr(MemCpy, S.Context.BuiltinFnTy, VK_RValue, Loc, nullptr); assert(MemCpyRef.isUsable() && "Builtin reference cannot fail"); Expr *CallArgs[] = { To, From, IntegerLiteral::Create(S.Context, Size, SizeType, Loc) }; ExprResult Call = S.ActOnCallExpr(/*Scope=*/nullptr, MemCpyRef.get(), Loc, CallArgs, Loc); assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!"); return Call.getAs<Stmt>(); } /// \brief Builds a statement that copies/moves the given entity from \p From to /// \c To. /// /// This routine is used to copy/move the members of a class with an /// implicitly-declared copy/move assignment operator. When the entities being /// copied are arrays, this routine builds for loops to copy them. /// /// \param S The Sema object used for type-checking. /// /// \param Loc The location where the implicit copy/move is being generated. /// /// \param T The type of the expressions being copied/moved. Both expressions /// must have this type. /// /// \param To The expression we are copying/moving to. /// /// \param From The expression we are copying/moving from. /// /// \param CopyingBaseSubobject Whether we're copying/moving a base subobject. /// Otherwise, it's a non-static member subobject. /// /// \param Copying Whether we're copying or moving. /// /// \param Depth Internal parameter recording the depth of the recursion. /// /// \returns A statement or a loop that copies the expressions, or StmtResult(0) /// if a memcpy should be used instead. static StmtResult buildSingleCopyAssignRecursively(Sema &S, SourceLocation Loc, QualType T, const ExprBuilder &To, const ExprBuilder &From, bool CopyingBaseSubobject, bool Copying, unsigned Depth = 0) { // C++11 [class.copy]p28: // Each subobject is assigned in the manner appropriate to its type: // // - if the subobject is of class type, as if by a call to operator= with // the subobject as the object expression and the corresponding // subobject of x as a single function argument (as if by explicit // qualification; that is, ignoring any possible virtual overriding // functions in more derived classes); // // C++03 [class.copy]p13: // - if the subobject is of class type, the copy assignment operator for // the class is used (as if by explicit qualification; that is, // ignoring any possible virtual overriding functions in more derived // classes); if (const RecordType *RecordTy = T->getAs<RecordType>()) { CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RecordTy->getDecl()); // Look for operator=. DeclarationName Name = S.Context.DeclarationNames.getCXXOperatorName(OO_Equal); LookupResult OpLookup(S, Name, Loc, Sema::LookupOrdinaryName); S.LookupQualifiedName(OpLookup, ClassDecl, false); // Prior to C++11, filter out any result that isn't a copy/move-assignment // operator. if (!S.getLangOpts().CPlusPlus11) { LookupResult::Filter F = OpLookup.makeFilter(); while (F.hasNext()) { NamedDecl *D = F.next(); if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) if (Method->isCopyAssignmentOperator() || (!Copying && Method->isMoveAssignmentOperator())) continue; F.erase(); } F.done(); } // Suppress the protected check (C++ [class.protected]) for each of the // assignment operators we found. This strange dance is required when // we're assigning via a base classes's copy-assignment operator. To // ensure that we're getting the right base class subobject (without // ambiguities), we need to cast "this" to that subobject type; to // ensure that we don't go through the virtual call mechanism, we need // to qualify the operator= name with the base class (see below). However, // this means that if the base class has a protected copy assignment // operator, the protected member access check will fail. So, we // rewrite "protected" access to "public" access in this case, since we // know by construction that we're calling from a derived class. if (CopyingBaseSubobject) { for (LookupResult::iterator L = OpLookup.begin(), LEnd = OpLookup.end(); L != LEnd; ++L) { if (L.getAccess() == AS_protected) L.setAccess(AS_public); } } // Create the nested-name-specifier that will be used to qualify the // reference to operator=; this is required to suppress the virtual // call mechanism. CXXScopeSpec SS; const Type *CanonicalT = S.Context.getCanonicalType(T.getTypePtr()); SS.MakeTrivial(S.Context, NestedNameSpecifier::Create(S.Context, nullptr, false, CanonicalT), Loc); // Create the reference to operator=. ExprResult OpEqualRef = S.BuildMemberReferenceExpr(To.build(S, Loc), T, Loc, /*isArrow=*/false, SS, /*TemplateKWLoc=*/SourceLocation(), /*FirstQualifierInScope=*/nullptr, OpLookup, /*TemplateArgs=*/nullptr, /*S*/nullptr, /*SuppressQualifierCheck=*/true); if (OpEqualRef.isInvalid()) return StmtError(); // Build the call to the assignment operator. Expr *FromInst = From.build(S, Loc); ExprResult Call = S.BuildCallToMemberFunction(/*Scope=*/nullptr, OpEqualRef.getAs<Expr>(), Loc, FromInst, Loc); if (Call.isInvalid()) return StmtError(); // If we built a call to a trivial 'operator=' while copying an array, // bail out. We'll replace the whole shebang with a memcpy. CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(Call.get()); if (CE && CE->getMethodDecl()->isTrivial() && Depth) return StmtResult((Stmt*)nullptr); // Convert to an expression-statement, and clean up any produced // temporaries. return S.ActOnExprStmt(Call); } // - if the subobject is of scalar type, the built-in assignment // operator is used. const ConstantArrayType *ArrayTy = S.Context.getAsConstantArrayType(T); if (!ArrayTy) { ExprResult Assignment = S.CreateBuiltinBinOp( Loc, BO_Assign, To.build(S, Loc), From.build(S, Loc)); if (Assignment.isInvalid()) return StmtError(); return S.ActOnExprStmt(Assignment); } // - if the subobject is an array, each element is assigned, in the // manner appropriate to the element type; // Construct a loop over the array bounds, e.g., // // for (__SIZE_TYPE__ i0 = 0; i0 != array-size; ++i0) // // that will copy each of the array elements. QualType SizeType = S.Context.getSizeType(); // Create the iteration variable. IdentifierInfo *IterationVarName = nullptr; { SmallString<8> Str; llvm::raw_svector_ostream OS(Str); OS << "__i" << Depth; IterationVarName = &S.Context.Idents.get(OS.str()); } VarDecl *IterationVar = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, IterationVarName, SizeType, S.Context.getTrivialTypeSourceInfo(SizeType, Loc), SC_None); // Initialize the iteration variable to zero. llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0); IterationVar->setInit(IntegerLiteral::Create(S.Context, Zero, SizeType, Loc)); // Creates a reference to the iteration variable. RefBuilder IterationVarRef(IterationVar, SizeType); LvalueConvBuilder IterationVarRefRVal(IterationVarRef); // Create the DeclStmt that holds the iteration variable. Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(IterationVar),Loc,Loc); // Subscript the "from" and "to" expressions with the iteration variable. SubscriptBuilder FromIndexCopy(From, IterationVarRefRVal); MoveCastBuilder FromIndexMove(FromIndexCopy); const ExprBuilder *FromIndex; if (Copying) FromIndex = &FromIndexCopy; else FromIndex = &FromIndexMove; SubscriptBuilder ToIndex(To, IterationVarRefRVal); // Build the copy/move for an individual element of the array. StmtResult Copy = buildSingleCopyAssignRecursively(S, Loc, ArrayTy->getElementType(), ToIndex, *FromIndex, CopyingBaseSubobject, Copying, Depth + 1); // Bail out if copying fails or if we determined that we should use memcpy. if (Copy.isInvalid() || !Copy.get()) return Copy; // Create the comparison against the array bound. llvm::APInt Upper = ArrayTy->getSize().zextOrTrunc(S.Context.getTypeSize(SizeType)); Expr *Comparison = new (S.Context) BinaryOperator(IterationVarRefRVal.build(S, Loc), IntegerLiteral::Create(S.Context, Upper, SizeType, Loc), BO_NE, S.Context.BoolTy, VK_RValue, OK_Ordinary, Loc, false); // Create the pre-increment of the iteration variable. Expr *Increment = new (S.Context) UnaryOperator(IterationVarRef.build(S, Loc), UO_PreInc, SizeType, VK_LValue, OK_Ordinary, Loc); // Construct the loop that copies all elements of this array. return S.ActOnForStmt(Loc, Loc, InitStmt, S.MakeFullExpr(Comparison), nullptr, S.MakeFullDiscardedValueExpr(Increment), Loc, Copy.get()); } static StmtResult buildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T, const ExprBuilder &To, const ExprBuilder &From, bool CopyingBaseSubobject, bool Copying) { // Maybe we should use a memcpy? if (T->isArrayType() && !T.isConstQualified() && !T.isVolatileQualified() && T.isTriviallyCopyableType(S.Context)) return buildMemcpyForAssignmentOp(S, Loc, T, To, From); StmtResult Result(buildSingleCopyAssignRecursively(S, Loc, T, To, From, CopyingBaseSubobject, Copying, 0)); // If we ended up picking a trivial assignment operator for an array of a // non-trivially-copyable class type, just emit a memcpy. if (!Result.isInvalid() && !Result.get()) return buildMemcpyForAssignmentOp(S, Loc, T, To, From); return Result; } Sema::ImplicitExceptionSpecification Sema::ComputeDefaultedCopyAssignmentExceptionSpec(CXXMethodDecl *MD) { CXXRecordDecl *ClassDecl = MD->getParent(); ImplicitExceptionSpecification ExceptSpec(*this); if (ClassDecl->isInvalidDecl()) return ExceptSpec; const FunctionProtoType *T = MD->getType()->castAs<FunctionProtoType>(); assert(T->getNumParams() == 1 && "not a copy assignment op"); unsigned ArgQuals = T->getParamType(0).getNonReferenceType().getCVRQualifiers(); // C++ [except.spec]p14: // An implicitly declared special member function (Clause 12) shall have an // exception-specification. [...] // It is unspecified whether or not an implicit copy assignment operator // attempts to deduplicate calls to assignment operators of virtual bases are // made. As such, this exception specification is effectively unspecified. // Based on a similar decision made for constness in C++0x, we're erring on // the side of assuming such calls to be made regardless of whether they // actually happen. for (const auto &Base : ClassDecl->bases()) { if (Base.isVirtual()) continue; CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(Base.getType()->getAs<RecordType>()->getDecl()); if (CXXMethodDecl *CopyAssign = LookupCopyingAssignment(BaseClassDecl, ArgQuals, false, 0)) ExceptSpec.CalledDecl(Base.getLocStart(), CopyAssign); } for (const auto &Base : ClassDecl->vbases()) { CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(Base.getType()->getAs<RecordType>()->getDecl()); if (CXXMethodDecl *CopyAssign = LookupCopyingAssignment(BaseClassDecl, ArgQuals, false, 0)) ExceptSpec.CalledDecl(Base.getLocStart(), CopyAssign); } for (const auto *Field : ClassDecl->fields()) { QualType FieldType = Context.getBaseElementType(Field->getType()); if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) { if (CXXMethodDecl *CopyAssign = LookupCopyingAssignment(FieldClassDecl, ArgQuals | FieldType.getCVRQualifiers(), false, 0)) ExceptSpec.CalledDecl(Field->getLocation(), CopyAssign); } } return ExceptSpec; } CXXMethodDecl *Sema::DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl) { // Note: The following rules are largely analoguous to the copy // constructor rules. Note that virtual bases are not taken into account // for determining the argument type of the operator. Note also that // operators taking an object instead of a reference are allowed. assert(ClassDecl->needsImplicitCopyAssignment()); DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyAssignment); if (DSM.isAlreadyBeingDeclared()) return nullptr; QualType ArgType = Context.getTypeDeclType(ClassDecl); QualType RetType = Context.getLValueReferenceType(ArgType); bool Const = ClassDecl->implicitCopyAssignmentHasConstParam(); if (Const) ArgType = ArgType.withConst(); ArgType = Context.getLValueReferenceType(ArgType); bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, CXXCopyAssignment, Const); // An implicitly-declared copy assignment operator is an inline public // member of its class. DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); SourceLocation ClassLoc = ClassDecl->getLocation(); DeclarationNameInfo NameInfo(Name, ClassLoc); CXXMethodDecl *CopyAssignment = CXXMethodDecl::Create(Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr, /*StorageClass=*/SC_None, /*isInline=*/true, Constexpr, SourceLocation()); CopyAssignment->setAccess(AS_public); CopyAssignment->setDefaulted(); CopyAssignment->setImplicit(); if (getLangOpts().CUDA) { inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyAssignment, CopyAssignment, /* ConstRHS */ Const, /* Diagnose */ false); } // Build an exception specification pointing back at this member. FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, CopyAssignment); CopyAssignment->setType(Context.getFunctionType(RetType, ArgType, EPI)); // Add the parameter to the operator. ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment, ClassLoc, ClassLoc, /*Id=*/nullptr, ArgType, /*TInfo=*/nullptr, SC_None, nullptr); CopyAssignment->setParams(FromParam); AddOverriddenMethods(ClassDecl, CopyAssignment); CopyAssignment->setTrivial( ClassDecl->needsOverloadResolutionForCopyAssignment() ? SpecialMemberIsTrivial(CopyAssignment, CXXCopyAssignment) : ClassDecl->hasTrivialCopyAssignment()); if (ShouldDeleteSpecialMember(CopyAssignment, CXXCopyAssignment)) SetDeclDeleted(CopyAssignment, ClassLoc); // Note that we have added this copy-assignment operator. ++ASTContext::NumImplicitCopyAssignmentOperatorsDeclared; if (Scope *S = getScopeForContext(ClassDecl)) PushOnScopeChains(CopyAssignment, S, false); ClassDecl->addDecl(CopyAssignment); return CopyAssignment; } /// Diagnose an implicit copy operation for a class which is odr-used, but /// which is deprecated because the class has a user-declared copy constructor, /// copy assignment operator, or destructor. static void diagnoseDeprecatedCopyOperation(Sema &S, CXXMethodDecl *CopyOp, SourceLocation UseLoc) { assert(CopyOp->isImplicit()); CXXRecordDecl *RD = CopyOp->getParent(); CXXMethodDecl *UserDeclaredOperation = nullptr; // In Microsoft mode, assignment operations don't affect constructors and // vice versa. if (RD->hasUserDeclaredDestructor()) { UserDeclaredOperation = RD->getDestructor(); } else if (!isa<CXXConstructorDecl>(CopyOp) && RD->hasUserDeclaredCopyConstructor() && !S.getLangOpts().MSVCCompat) { // Find any user-declared copy constructor. for (auto *I : RD->ctors()) { if (I->isCopyConstructor()) { UserDeclaredOperation = I; break; } } assert(UserDeclaredOperation); } else if (isa<CXXConstructorDecl>(CopyOp) && RD->hasUserDeclaredCopyAssignment() && !S.getLangOpts().MSVCCompat) { // Find any user-declared move assignment operator. for (auto *I : RD->methods()) { if (I->isCopyAssignmentOperator()) { UserDeclaredOperation = I; break; } } assert(UserDeclaredOperation); } if (UserDeclaredOperation) { S.Diag(UserDeclaredOperation->getLocation(), diag::warn_deprecated_copy_operation) << RD << /*copy assignment*/!isa<CXXConstructorDecl>(CopyOp) << /*destructor*/isa<CXXDestructorDecl>(UserDeclaredOperation); S.Diag(UseLoc, diag::note_member_synthesized_at) << (isa<CXXConstructorDecl>(CopyOp) ? Sema::CXXCopyConstructor : Sema::CXXCopyAssignment) << RD; } } void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation, CXXMethodDecl *CopyAssignOperator) { assert((CopyAssignOperator->isDefaulted() && CopyAssignOperator->isOverloadedOperator() && CopyAssignOperator->getOverloadedOperator() == OO_Equal && !CopyAssignOperator->doesThisDeclarationHaveABody() && !CopyAssignOperator->isDeleted()) && "DefineImplicitCopyAssignment called for wrong function"); CXXRecordDecl *ClassDecl = CopyAssignOperator->getParent(); if (ClassDecl->isInvalidDecl() || CopyAssignOperator->isInvalidDecl()) { CopyAssignOperator->setInvalidDecl(); return; } // C++11 [class.copy]p18: // The [definition of an implicitly declared copy assignment operator] is // deprecated if the class has a user-declared copy constructor or a // user-declared destructor. if (getLangOpts().CPlusPlus11 && CopyAssignOperator->isImplicit()) diagnoseDeprecatedCopyOperation(*this, CopyAssignOperator, CurrentLocation); CopyAssignOperator->markUsed(Context); SynthesizedFunctionScope Scope(*this, CopyAssignOperator); DiagnosticErrorTrap Trap(Diags); // C++0x [class.copy]p30: // The implicitly-defined or explicitly-defaulted copy assignment operator // for a non-union class X performs memberwise copy assignment of its // subobjects. The direct base classes of X are assigned first, in the // order of their declaration in the base-specifier-list, and then the // immediate non-static data members of X are assigned, in the order in // which they were declared in the class definition. // The statements that form the synthesized function body. SmallVector<Stmt*, 8> Statements; // The parameter for the "other" object, which we are copying from. ParmVarDecl *Other = CopyAssignOperator->getParamDecl(0); Qualifiers OtherQuals = Other->getType().getQualifiers(); QualType OtherRefType = Other->getType(); if (const LValueReferenceType *OtherRef = OtherRefType->getAs<LValueReferenceType>()) { OtherRefType = OtherRef->getPointeeType(); OtherQuals = OtherRefType.getQualifiers(); } // Our location for everything implicitly-generated. SourceLocation Loc = CopyAssignOperator->getLocEnd().isValid() ? CopyAssignOperator->getLocEnd() : CopyAssignOperator->getLocation(); // Builds a DeclRefExpr for the "other" object. RefBuilder OtherRef(Other, OtherRefType); // Builds the "this" pointer. ThisBuilder This; // Assign base classes. bool Invalid = false; for (auto &Base : ClassDecl->bases()) { // Form the assignment: // static_cast<Base*>(this)->Base::operator=(static_cast<Base&>(other)); QualType BaseType = Base.getType().getUnqualifiedType(); if (!BaseType->isRecordType()) { Invalid = true; continue; } CXXCastPath BasePath; BasePath.push_back(&Base); // Construct the "from" expression, which is an implicit cast to the // appropriately-qualified base type. CastBuilder From(OtherRef, Context.getQualifiedType(BaseType, OtherQuals), VK_LValue, BasePath); // Dereference "this". DerefBuilder DerefThis(This); CastBuilder To(DerefThis, Context.getCVRQualifiedType( BaseType, CopyAssignOperator->getTypeQualifiers()), VK_LValue, BasePath); // Build the copy. StmtResult Copy = buildSingleCopyAssign(*this, Loc, BaseType, To, From, /*CopyingBaseSubobject=*/true, /*Copying=*/true); if (Copy.isInvalid()) { Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXCopyAssignment << Context.getTagDeclType(ClassDecl); CopyAssignOperator->setInvalidDecl(); return; } // Success! Record the copy. Statements.push_back(Copy.getAs<Expr>()); } // Assign non-static members. for (auto *Field : ClassDecl->fields()) { // FIXME: We should form some kind of AST representation for the implied // memcpy in a union copy operation. if (Field->isUnnamedBitfield() || Field->getParent()->isUnion()) continue; if (Field->isInvalidDecl()) { Invalid = true; continue; } // Check for members of reference type; we can't copy those. if (Field->getType()->isReferenceType()) { Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign) << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName(); Diag(Field->getLocation(), diag::note_declared_at); Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXCopyAssignment << Context.getTagDeclType(ClassDecl); Invalid = true; continue; } // Check for members of const-qualified, non-class type. QualType BaseType = Context.getBaseElementType(Field->getType()); if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) { Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign) << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName(); Diag(Field->getLocation(), diag::note_declared_at); Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXCopyAssignment << Context.getTagDeclType(ClassDecl); Invalid = true; continue; } // Suppress assigning zero-width bitfields. if (Field->isBitField() && Field->getBitWidthValue(Context) == 0) continue; QualType FieldType = Field->getType().getNonReferenceType(); if (FieldType->isIncompleteArrayType()) { assert(ClassDecl->hasFlexibleArrayMember() && "Incomplete array type is not valid"); continue; } // Build references to the field in the object we're copying from and to. CXXScopeSpec SS; // Intentionally empty LookupResult MemberLookup(*this, Field->getDeclName(), Loc, LookupMemberName); MemberLookup.addDecl(Field); MemberLookup.resolveKind(); MemberBuilder From(OtherRef, OtherRefType, /*IsArrow=*/false, MemberLookup); MemberBuilder To(This, getCurrentThisType(), /*IsArrow=*/true, MemberLookup); // Build the copy of this field. StmtResult Copy = buildSingleCopyAssign(*this, Loc, FieldType, To, From, /*CopyingBaseSubobject=*/false, /*Copying=*/true); if (Copy.isInvalid()) { Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXCopyAssignment << Context.getTagDeclType(ClassDecl); CopyAssignOperator->setInvalidDecl(); return; } // Success! Record the copy. Statements.push_back(Copy.getAs<Stmt>()); } if (!Invalid) { // Add a "return *this;" ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc)); StmtResult Return = BuildReturnStmt(Loc, ThisObj.get()); if (Return.isInvalid()) Invalid = true; else { Statements.push_back(Return.getAs<Stmt>()); if (Trap.hasErrorOccurred()) { Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXCopyAssignment << Context.getTagDeclType(ClassDecl); Invalid = true; } } } // The exception specification is needed because we are defining the // function. ResolveExceptionSpec(CurrentLocation, CopyAssignOperator->getType()->castAs<FunctionProtoType>()); if (Invalid) { CopyAssignOperator->setInvalidDecl(); return; } StmtResult Body; { CompoundScopeRAII CompoundScope(*this); Body = ActOnCompoundStmt(Loc, Loc, Statements, /*isStmtExpr=*/false); assert(!Body.isInvalid() && "Compound statement creation cannot fail"); } CopyAssignOperator->setBody(Body.getAs<Stmt>()); if (ASTMutationListener *L = getASTMutationListener()) { L->CompletedImplicitDefinition(CopyAssignOperator); } } Sema::ImplicitExceptionSpecification Sema::ComputeDefaultedMoveAssignmentExceptionSpec(CXXMethodDecl *MD) { CXXRecordDecl *ClassDecl = MD->getParent(); ImplicitExceptionSpecification ExceptSpec(*this); if (ClassDecl->isInvalidDecl()) return ExceptSpec; // C++0x [except.spec]p14: // An implicitly declared special member function (Clause 12) shall have an // exception-specification. [...] // It is unspecified whether or not an implicit move assignment operator // attempts to deduplicate calls to assignment operators of virtual bases are // made. As such, this exception specification is effectively unspecified. // Based on a similar decision made for constness in C++0x, we're erring on // the side of assuming such calls to be made regardless of whether they // actually happen. // Note that a move constructor is not implicitly declared when there are // virtual bases, but it can still be user-declared and explicitly defaulted. for (const auto &Base : ClassDecl->bases()) { if (Base.isVirtual()) continue; CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(Base.getType()->getAs<RecordType>()->getDecl()); if (CXXMethodDecl *MoveAssign = LookupMovingAssignment(BaseClassDecl, 0, false, 0)) ExceptSpec.CalledDecl(Base.getLocStart(), MoveAssign); } for (const auto &Base : ClassDecl->vbases()) { CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(Base.getType()->getAs<RecordType>()->getDecl()); if (CXXMethodDecl *MoveAssign = LookupMovingAssignment(BaseClassDecl, 0, false, 0)) ExceptSpec.CalledDecl(Base.getLocStart(), MoveAssign); } for (const auto *Field : ClassDecl->fields()) { QualType FieldType = Context.getBaseElementType(Field->getType()); if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) { if (CXXMethodDecl *MoveAssign = LookupMovingAssignment(FieldClassDecl, FieldType.getCVRQualifiers(), false, 0)) ExceptSpec.CalledDecl(Field->getLocation(), MoveAssign); } } return ExceptSpec; } CXXMethodDecl *Sema::DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl) { assert(ClassDecl->needsImplicitMoveAssignment()); DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveAssignment); if (DSM.isAlreadyBeingDeclared()) return nullptr; // Note: The following rules are largely analoguous to the move // constructor rules. QualType ArgType = Context.getTypeDeclType(ClassDecl); QualType RetType = Context.getLValueReferenceType(ArgType); ArgType = Context.getRValueReferenceType(ArgType); bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, CXXMoveAssignment, false); // An implicitly-declared move assignment operator is an inline public // member of its class. DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); SourceLocation ClassLoc = ClassDecl->getLocation(); DeclarationNameInfo NameInfo(Name, ClassLoc); CXXMethodDecl *MoveAssignment = CXXMethodDecl::Create(Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr, /*StorageClass=*/SC_None, /*isInline=*/true, Constexpr, SourceLocation()); MoveAssignment->setAccess(AS_public); MoveAssignment->setDefaulted(); MoveAssignment->setImplicit(); if (getLangOpts().CUDA) { inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveAssignment, MoveAssignment, /* ConstRHS */ false, /* Diagnose */ false); } // Build an exception specification pointing back at this member. FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, MoveAssignment); MoveAssignment->setType(Context.getFunctionType(RetType, ArgType, EPI)); // Add the parameter to the operator. ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveAssignment, ClassLoc, ClassLoc, /*Id=*/nullptr, ArgType, /*TInfo=*/nullptr, SC_None, nullptr); MoveAssignment->setParams(FromParam); AddOverriddenMethods(ClassDecl, MoveAssignment); MoveAssignment->setTrivial( ClassDecl->needsOverloadResolutionForMoveAssignment() ? SpecialMemberIsTrivial(MoveAssignment, CXXMoveAssignment) : ClassDecl->hasTrivialMoveAssignment()); if (ShouldDeleteSpecialMember(MoveAssignment, CXXMoveAssignment)) { ClassDecl->setImplicitMoveAssignmentIsDeleted(); SetDeclDeleted(MoveAssignment, ClassLoc); } // Note that we have added this copy-assignment operator. ++ASTContext::NumImplicitMoveAssignmentOperatorsDeclared; if (Scope *S = getScopeForContext(ClassDecl)) PushOnScopeChains(MoveAssignment, S, false); ClassDecl->addDecl(MoveAssignment); return MoveAssignment; } /// Check if we're implicitly defining a move assignment operator for a class /// with virtual bases. Such a move assignment might move-assign the virtual /// base multiple times. static void checkMoveAssignmentForRepeatedMove(Sema &S, CXXRecordDecl *Class, SourceLocation CurrentLocation) { assert(!Class->isDependentContext() && "should not define dependent move"); // Only a virtual base could get implicitly move-assigned multiple times. // Only a non-trivial move assignment can observe this. We only want to // diagnose if we implicitly define an assignment operator that assigns // two base classes, both of which move-assign the same virtual base. if (Class->getNumVBases() == 0 || Class->hasTrivialMoveAssignment() || Class->getNumBases() < 2) return; llvm::SmallVector<CXXBaseSpecifier *, 16> Worklist; typedef llvm::DenseMap<CXXRecordDecl*, CXXBaseSpecifier*> VBaseMap; VBaseMap VBases; for (auto &BI : Class->bases()) { Worklist.push_back(&BI); while (!Worklist.empty()) { CXXBaseSpecifier *BaseSpec = Worklist.pop_back_val(); CXXRecordDecl *Base = BaseSpec->getType()->getAsCXXRecordDecl(); // If the base has no non-trivial move assignment operators, // we don't care about moves from it. if (!Base->hasNonTrivialMoveAssignment()) continue; // If there's nothing virtual here, skip it. if (!BaseSpec->isVirtual() && !Base->getNumVBases()) continue; // If we're not actually going to call a move assignment for this base, // or the selected move assignment is trivial, skip it. Sema::SpecialMemberOverloadResult *SMOR = S.LookupSpecialMember(Base, Sema::CXXMoveAssignment, /*ConstArg*/false, /*VolatileArg*/false, /*RValueThis*/true, /*ConstThis*/false, /*VolatileThis*/false); if (!SMOR->getMethod() || SMOR->getMethod()->isTrivial() || !SMOR->getMethod()->isMoveAssignmentOperator()) continue; if (BaseSpec->isVirtual()) { // We're going to move-assign this virtual base, and its move // assignment operator is not trivial. If this can happen for // multiple distinct direct bases of Class, diagnose it. (If it // only happens in one base, we'll diagnose it when synthesizing // that base class's move assignment operator.) CXXBaseSpecifier *&Existing = VBases.insert(std::make_pair(Base->getCanonicalDecl(), &BI)) .first->second; if (Existing && Existing != &BI) { S.Diag(CurrentLocation, diag::warn_vbase_moved_multiple_times) << Class << Base; S.Diag(Existing->getLocStart(), diag::note_vbase_moved_here) << (Base->getCanonicalDecl() == Existing->getType()->getAsCXXRecordDecl()->getCanonicalDecl()) << Base << Existing->getType() << Existing->getSourceRange(); S.Diag(BI.getLocStart(), diag::note_vbase_moved_here) << (Base->getCanonicalDecl() == BI.getType()->getAsCXXRecordDecl()->getCanonicalDecl()) << Base << BI.getType() << BaseSpec->getSourceRange(); // Only diagnose each vbase once. Existing = nullptr; } } else { // Only walk over bases that have defaulted move assignment operators. // We assume that any user-provided move assignment operator handles // the multiple-moves-of-vbase case itself somehow. if (!SMOR->getMethod()->isDefaulted()) continue; // We're going to move the base classes of Base. Add them to the list. for (auto &BI : Base->bases()) Worklist.push_back(&BI); } } } } void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation, CXXMethodDecl *MoveAssignOperator) { assert((MoveAssignOperator->isDefaulted() && MoveAssignOperator->isOverloadedOperator() && MoveAssignOperator->getOverloadedOperator() == OO_Equal && !MoveAssignOperator->doesThisDeclarationHaveABody() && !MoveAssignOperator->isDeleted()) && "DefineImplicitMoveAssignment called for wrong function"); CXXRecordDecl *ClassDecl = MoveAssignOperator->getParent(); if (ClassDecl->isInvalidDecl() || MoveAssignOperator->isInvalidDecl()) { MoveAssignOperator->setInvalidDecl(); return; } MoveAssignOperator->markUsed(Context); SynthesizedFunctionScope Scope(*this, MoveAssignOperator); DiagnosticErrorTrap Trap(Diags); // C++0x [class.copy]p28: // The implicitly-defined or move assignment operator for a non-union class // X performs memberwise move assignment of its subobjects. The direct base // classes of X are assigned first, in the order of their declaration in the // base-specifier-list, and then the immediate non-static data members of X // are assigned, in the order in which they were declared in the class // definition. // Issue a warning if our implicit move assignment operator will move // from a virtual base more than once. checkMoveAssignmentForRepeatedMove(*this, ClassDecl, CurrentLocation); // The statements that form the synthesized function body. SmallVector<Stmt*, 8> Statements; // The parameter for the "other" object, which we are move from. ParmVarDecl *Other = MoveAssignOperator->getParamDecl(0); QualType OtherRefType = Other->getType()-> getAs<RValueReferenceType>()->getPointeeType(); assert(!OtherRefType.getQualifiers() && "Bad argument type of defaulted move assignment"); // Our location for everything implicitly-generated. SourceLocation Loc = MoveAssignOperator->getLocEnd().isValid() ? MoveAssignOperator->getLocEnd() : MoveAssignOperator->getLocation(); // Builds a reference to the "other" object. RefBuilder OtherRef(Other, OtherRefType); // Cast to rvalue. MoveCastBuilder MoveOther(OtherRef); // Builds the "this" pointer. ThisBuilder This; // Assign base classes. bool Invalid = false; for (auto &Base : ClassDecl->bases()) { // C++11 [class.copy]p28: // It is unspecified whether subobjects representing virtual base classes // are assigned more than once by the implicitly-defined copy assignment // operator. // FIXME: Do not assign to a vbase that will be assigned by some other base // class. For a move-assignment, this can result in the vbase being moved // multiple times. // Form the assignment: // static_cast<Base*>(this)->Base::operator=(static_cast<Base&&>(other)); QualType BaseType = Base.getType().getUnqualifiedType(); if (!BaseType->isRecordType()) { Invalid = true; continue; } CXXCastPath BasePath; BasePath.push_back(&Base); // Construct the "from" expression, which is an implicit cast to the // appropriately-qualified base type. CastBuilder From(OtherRef, BaseType, VK_XValue, BasePath); // Dereference "this". DerefBuilder DerefThis(This); // Implicitly cast "this" to the appropriately-qualified base type. CastBuilder To(DerefThis, Context.getCVRQualifiedType( BaseType, MoveAssignOperator->getTypeQualifiers()), VK_LValue, BasePath); // Build the move. StmtResult Move = buildSingleCopyAssign(*this, Loc, BaseType, To, From, /*CopyingBaseSubobject=*/true, /*Copying=*/false); if (Move.isInvalid()) { Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXMoveAssignment << Context.getTagDeclType(ClassDecl); MoveAssignOperator->setInvalidDecl(); return; } // Success! Record the move. Statements.push_back(Move.getAs<Expr>()); } // Assign non-static members. for (auto *Field : ClassDecl->fields()) { // FIXME: We should form some kind of AST representation for the implied // memcpy in a union copy operation. if (Field->isUnnamedBitfield() || Field->getParent()->isUnion()) continue; if (Field->isInvalidDecl()) { Invalid = true; continue; } // Check for members of reference type; we can't move those. if (Field->getType()->isReferenceType()) { Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign) << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName(); Diag(Field->getLocation(), diag::note_declared_at); Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXMoveAssignment << Context.getTagDeclType(ClassDecl); Invalid = true; continue; } // Check for members of const-qualified, non-class type. QualType BaseType = Context.getBaseElementType(Field->getType()); if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) { Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign) << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName(); Diag(Field->getLocation(), diag::note_declared_at); Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXMoveAssignment << Context.getTagDeclType(ClassDecl); Invalid = true; continue; } // Suppress assigning zero-width bitfields. if (Field->isBitField() && Field->getBitWidthValue(Context) == 0) continue; QualType FieldType = Field->getType().getNonReferenceType(); if (FieldType->isIncompleteArrayType()) { assert(ClassDecl->hasFlexibleArrayMember() && "Incomplete array type is not valid"); continue; } // Build references to the field in the object we're copying from and to. LookupResult MemberLookup(*this, Field->getDeclName(), Loc, LookupMemberName); MemberLookup.addDecl(Field); MemberLookup.resolveKind(); MemberBuilder From(MoveOther, OtherRefType, /*IsArrow=*/false, MemberLookup); MemberBuilder To(This, getCurrentThisType(), /*IsArrow=*/true, MemberLookup); assert(!From.build(*this, Loc)->isLValue() && // could be xvalue or prvalue "Member reference with rvalue base must be rvalue except for reference " "members, which aren't allowed for move assignment."); // Build the move of this field. StmtResult Move = buildSingleCopyAssign(*this, Loc, FieldType, To, From, /*CopyingBaseSubobject=*/false, /*Copying=*/false); if (Move.isInvalid()) { Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXMoveAssignment << Context.getTagDeclType(ClassDecl); MoveAssignOperator->setInvalidDecl(); return; } // Success! Record the copy. Statements.push_back(Move.getAs<Stmt>()); } if (!Invalid) { // Add a "return *this;" ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc)); StmtResult Return = BuildReturnStmt(Loc, ThisObj.get()); if (Return.isInvalid()) Invalid = true; else { Statements.push_back(Return.getAs<Stmt>()); if (Trap.hasErrorOccurred()) { Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXMoveAssignment << Context.getTagDeclType(ClassDecl); Invalid = true; } } } // The exception specification is needed because we are defining the // function. ResolveExceptionSpec(CurrentLocation, MoveAssignOperator->getType()->castAs<FunctionProtoType>()); if (Invalid) { MoveAssignOperator->setInvalidDecl(); return; } StmtResult Body; { CompoundScopeRAII CompoundScope(*this); Body = ActOnCompoundStmt(Loc, Loc, Statements, /*isStmtExpr=*/false); assert(!Body.isInvalid() && "Compound statement creation cannot fail"); } MoveAssignOperator->setBody(Body.getAs<Stmt>()); if (ASTMutationListener *L = getASTMutationListener()) { L->CompletedImplicitDefinition(MoveAssignOperator); } } Sema::ImplicitExceptionSpecification Sema::ComputeDefaultedCopyCtorExceptionSpec(CXXMethodDecl *MD) { CXXRecordDecl *ClassDecl = MD->getParent(); ImplicitExceptionSpecification ExceptSpec(*this); if (ClassDecl->isInvalidDecl()) return ExceptSpec; const FunctionProtoType *T = MD->getType()->castAs<FunctionProtoType>(); assert(T->getNumParams() >= 1 && "not a copy ctor"); unsigned Quals = T->getParamType(0).getNonReferenceType().getCVRQualifiers(); // C++ [except.spec]p14: // An implicitly declared special member function (Clause 12) shall have an // exception-specification. [...] for (const auto &Base : ClassDecl->bases()) { // Virtual bases are handled below. if (Base.isVirtual()) continue; CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(Base.getType()->getAs<RecordType>()->getDecl()); if (CXXConstructorDecl *CopyConstructor = LookupCopyingConstructor(BaseClassDecl, Quals)) ExceptSpec.CalledDecl(Base.getLocStart(), CopyConstructor); } for (const auto &Base : ClassDecl->vbases()) { CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(Base.getType()->getAs<RecordType>()->getDecl()); if (CXXConstructorDecl *CopyConstructor = LookupCopyingConstructor(BaseClassDecl, Quals)) ExceptSpec.CalledDecl(Base.getLocStart(), CopyConstructor); } for (const auto *Field : ClassDecl->fields()) { QualType FieldType = Context.getBaseElementType(Field->getType()); if (CXXRecordDecl *FieldClassDecl = FieldType->getAsCXXRecordDecl()) { if (CXXConstructorDecl *CopyConstructor = LookupCopyingConstructor(FieldClassDecl, Quals | FieldType.getCVRQualifiers())) ExceptSpec.CalledDecl(Field->getLocation(), CopyConstructor); } } return ExceptSpec; } CXXConstructorDecl *Sema::DeclareImplicitCopyConstructor( CXXRecordDecl *ClassDecl) { // C++ [class.copy]p4: // If the class definition does not explicitly declare a copy // constructor, one is declared implicitly. assert(ClassDecl->needsImplicitCopyConstructor()); DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyConstructor); if (DSM.isAlreadyBeingDeclared()) return nullptr; QualType ClassType = Context.getTypeDeclType(ClassDecl); QualType ArgType = ClassType; bool Const = ClassDecl->implicitCopyConstructorHasConstParam(); if (Const) ArgType = ArgType.withConst(); ArgType = Context.getLValueReferenceType(ArgType); bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, CXXCopyConstructor, Const); DeclarationName Name = Context.DeclarationNames.getCXXConstructorName( Context.getCanonicalType(ClassType)); SourceLocation ClassLoc = ClassDecl->getLocation(); DeclarationNameInfo NameInfo(Name, ClassLoc); // An implicitly-declared copy constructor is an inline public // member of its class. CXXConstructorDecl *CopyConstructor = CXXConstructorDecl::Create( Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr, /*isExplicit=*/false, /*isInline=*/true, /*isImplicitlyDeclared=*/true, Constexpr); CopyConstructor->setAccess(AS_public); CopyConstructor->setDefaulted(); if (getLangOpts().CUDA) { inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyConstructor, CopyConstructor, /* ConstRHS */ Const, /* Diagnose */ false); } // Build an exception specification pointing back at this member. FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, CopyConstructor); CopyConstructor->setType( Context.getFunctionType(Context.VoidTy, ArgType, EPI)); // Add the parameter to the constructor. ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor, ClassLoc, ClassLoc, /*IdentifierInfo=*/nullptr, ArgType, /*TInfo=*/nullptr, SC_None, nullptr); CopyConstructor->setParams(FromParam); CopyConstructor->setTrivial( ClassDecl->needsOverloadResolutionForCopyConstructor() ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor) : ClassDecl->hasTrivialCopyConstructor()); if (ShouldDeleteSpecialMember(CopyConstructor, CXXCopyConstructor)) SetDeclDeleted(CopyConstructor, ClassLoc); // Note that we have declared this constructor. ++ASTContext::NumImplicitCopyConstructorsDeclared; if (Scope *S = getScopeForContext(ClassDecl)) PushOnScopeChains(CopyConstructor, S, false); ClassDecl->addDecl(CopyConstructor); return CopyConstructor; } void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation, CXXConstructorDecl *CopyConstructor) { assert((CopyConstructor->isDefaulted() && CopyConstructor->isCopyConstructor() && !CopyConstructor->doesThisDeclarationHaveABody() && !CopyConstructor->isDeleted()) && "DefineImplicitCopyConstructor - call it for implicit copy ctor"); CXXRecordDecl *ClassDecl = CopyConstructor->getParent(); assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor"); // C++11 [class.copy]p7: // The [definition of an implicitly declared copy constructor] is // deprecated if the class has a user-declared copy assignment operator // or a user-declared destructor. if (getLangOpts().CPlusPlus11 && CopyConstructor->isImplicit()) diagnoseDeprecatedCopyOperation(*this, CopyConstructor, CurrentLocation); SynthesizedFunctionScope Scope(*this, CopyConstructor); DiagnosticErrorTrap Trap(Diags); if (SetCtorInitializers(CopyConstructor, /*AnyErrors=*/false) || Trap.hasErrorOccurred()) { Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXCopyConstructor << Context.getTagDeclType(ClassDecl); CopyConstructor->setInvalidDecl(); } else { SourceLocation Loc = CopyConstructor->getLocEnd().isValid() ? CopyConstructor->getLocEnd() : CopyConstructor->getLocation(); Sema::CompoundScopeRAII CompoundScope(*this); CopyConstructor->setBody( ActOnCompoundStmt(Loc, Loc, None, /*isStmtExpr=*/false).getAs<Stmt>()); } // The exception specification is needed because we are defining the // function. ResolveExceptionSpec(CurrentLocation, CopyConstructor->getType()->castAs<FunctionProtoType>()); CopyConstructor->markUsed(Context); MarkVTableUsed(CurrentLocation, ClassDecl); if (ASTMutationListener *L = getASTMutationListener()) { L->CompletedImplicitDefinition(CopyConstructor); } } Sema::ImplicitExceptionSpecification Sema::ComputeDefaultedMoveCtorExceptionSpec(CXXMethodDecl *MD) { CXXRecordDecl *ClassDecl = MD->getParent(); // C++ [except.spec]p14: // An implicitly declared special member function (Clause 12) shall have an // exception-specification. [...] ImplicitExceptionSpecification ExceptSpec(*this); if (ClassDecl->isInvalidDecl()) return ExceptSpec; // Direct base-class constructors. for (const auto &B : ClassDecl->bases()) { if (B.isVirtual()) // Handled below. continue; if (const RecordType *BaseType = B.getType()->getAs<RecordType>()) { CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl()); CXXConstructorDecl *Constructor = LookupMovingConstructor(BaseClassDecl, 0); // If this is a deleted function, add it anyway. This might be conformant // with the standard. This might not. I'm not sure. It might not matter. if (Constructor) ExceptSpec.CalledDecl(B.getLocStart(), Constructor); } } // Virtual base-class constructors. for (const auto &B : ClassDecl->vbases()) { if (const RecordType *BaseType = B.getType()->getAs<RecordType>()) { CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl()); CXXConstructorDecl *Constructor = LookupMovingConstructor(BaseClassDecl, 0); // If this is a deleted function, add it anyway. This might be conformant // with the standard. This might not. I'm not sure. It might not matter. if (Constructor) ExceptSpec.CalledDecl(B.getLocStart(), Constructor); } } // Field constructors. for (const auto *F : ClassDecl->fields()) { QualType FieldType = Context.getBaseElementType(F->getType()); if (CXXRecordDecl *FieldRecDecl = FieldType->getAsCXXRecordDecl()) { CXXConstructorDecl *Constructor = LookupMovingConstructor(FieldRecDecl, FieldType.getCVRQualifiers()); // If this is a deleted function, add it anyway. This might be conformant // with the standard. This might not. I'm not sure. It might not matter. // In particular, the problem is that this function never gets called. It // might just be ill-formed because this function attempts to refer to // a deleted function here. if (Constructor) ExceptSpec.CalledDecl(F->getLocation(), Constructor); } } return ExceptSpec; } CXXConstructorDecl *Sema::DeclareImplicitMoveConstructor( CXXRecordDecl *ClassDecl) { assert(ClassDecl->needsImplicitMoveConstructor()); DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveConstructor); if (DSM.isAlreadyBeingDeclared()) return nullptr; QualType ClassType = Context.getTypeDeclType(ClassDecl); QualType ArgType = Context.getRValueReferenceType(ClassType); bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, CXXMoveConstructor, false); DeclarationName Name = Context.DeclarationNames.getCXXConstructorName( Context.getCanonicalType(ClassType)); SourceLocation ClassLoc = ClassDecl->getLocation(); DeclarationNameInfo NameInfo(Name, ClassLoc); // C++11 [class.copy]p11: // An implicitly-declared copy/move constructor is an inline public // member of its class. CXXConstructorDecl *MoveConstructor = CXXConstructorDecl::Create( Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr, /*isExplicit=*/false, /*isInline=*/true, /*isImplicitlyDeclared=*/true, Constexpr); MoveConstructor->setAccess(AS_public); MoveConstructor->setDefaulted(); if (getLangOpts().CUDA) { inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveConstructor, MoveConstructor, /* ConstRHS */ false, /* Diagnose */ false); } // Build an exception specification pointing back at this member. FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, MoveConstructor); MoveConstructor->setType( Context.getFunctionType(Context.VoidTy, ArgType, EPI)); // Add the parameter to the constructor. ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveConstructor, ClassLoc, ClassLoc, /*IdentifierInfo=*/nullptr, ArgType, /*TInfo=*/nullptr, SC_None, nullptr); MoveConstructor->setParams(FromParam); MoveConstructor->setTrivial( ClassDecl->needsOverloadResolutionForMoveConstructor() ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor) : ClassDecl->hasTrivialMoveConstructor()); if (ShouldDeleteSpecialMember(MoveConstructor, CXXMoveConstructor)) { ClassDecl->setImplicitMoveConstructorIsDeleted(); SetDeclDeleted(MoveConstructor, ClassLoc); } // Note that we have declared this constructor. ++ASTContext::NumImplicitMoveConstructorsDeclared; if (Scope *S = getScopeForContext(ClassDecl)) PushOnScopeChains(MoveConstructor, S, false); ClassDecl->addDecl(MoveConstructor); return MoveConstructor; } void Sema::DefineImplicitMoveConstructor(SourceLocation CurrentLocation, CXXConstructorDecl *MoveConstructor) { assert((MoveConstructor->isDefaulted() && MoveConstructor->isMoveConstructor() && !MoveConstructor->doesThisDeclarationHaveABody() && !MoveConstructor->isDeleted()) && "DefineImplicitMoveConstructor - call it for implicit move ctor"); CXXRecordDecl *ClassDecl = MoveConstructor->getParent(); assert(ClassDecl && "DefineImplicitMoveConstructor - invalid constructor"); SynthesizedFunctionScope Scope(*this, MoveConstructor); DiagnosticErrorTrap Trap(Diags); if (SetCtorInitializers(MoveConstructor, /*AnyErrors=*/false) || Trap.hasErrorOccurred()) { Diag(CurrentLocation, diag::note_member_synthesized_at) << CXXMoveConstructor << Context.getTagDeclType(ClassDecl); MoveConstructor->setInvalidDecl(); } else { SourceLocation Loc = MoveConstructor->getLocEnd().isValid() ? MoveConstructor->getLocEnd() : MoveConstructor->getLocation(); Sema::CompoundScopeRAII CompoundScope(*this); MoveConstructor->setBody(ActOnCompoundStmt( Loc, Loc, None, /*isStmtExpr=*/ false).getAs<Stmt>()); } // The exception specification is needed because we are defining the // function. ResolveExceptionSpec(CurrentLocation, MoveConstructor->getType()->castAs<FunctionProtoType>()); MoveConstructor->markUsed(Context); MarkVTableUsed(CurrentLocation, ClassDecl); if (ASTMutationListener *L = getASTMutationListener()) { L->CompletedImplicitDefinition(MoveConstructor); } } bool Sema::isImplicitlyDeleted(FunctionDecl *FD) { return FD->isDeleted() && FD->isDefaulted() && isa<CXXMethodDecl>(FD); } void Sema::DefineImplicitLambdaToFunctionPointerConversion( SourceLocation CurrentLocation, CXXConversionDecl *Conv) { CXXRecordDecl *Lambda = Conv->getParent(); CXXMethodDecl *CallOp = Lambda->getLambdaCallOperator(); // If we are defining a specialization of a conversion to function-ptr // cache the deduced template arguments for this specialization // so that we can use them to retrieve the corresponding call-operator // and static-invoker. const TemplateArgumentList *DeducedTemplateArgs = nullptr; // Retrieve the corresponding call-operator specialization. if (Lambda->isGenericLambda()) { assert(Conv->isFunctionTemplateSpecialization()); FunctionTemplateDecl *CallOpTemplate = CallOp->getDescribedFunctionTemplate(); DeducedTemplateArgs = Conv->getTemplateSpecializationArgs(); void *InsertPos = nullptr; FunctionDecl *CallOpSpec = CallOpTemplate->findSpecialization( DeducedTemplateArgs->asArray(), InsertPos); assert(CallOpSpec && "Conversion operator must have a corresponding call operator"); CallOp = cast<CXXMethodDecl>(CallOpSpec); } // Mark the call operator referenced (and add to pending instantiations // if necessary). // For both the conversion and static-invoker template specializations // we construct their body's in this function, so no need to add them // to the PendingInstantiations. MarkFunctionReferenced(CurrentLocation, CallOp); SynthesizedFunctionScope Scope(*this, Conv); DiagnosticErrorTrap Trap(Diags); // Retrieve the static invoker... CXXMethodDecl *Invoker = Lambda->getLambdaStaticInvoker(); // ... and get the corresponding specialization for a generic lambda. if (Lambda->isGenericLambda()) { assert(DeducedTemplateArgs && "Must have deduced template arguments from Conversion Operator"); FunctionTemplateDecl *InvokeTemplate = Invoker->getDescribedFunctionTemplate(); void *InsertPos = nullptr; FunctionDecl *InvokeSpec = InvokeTemplate->findSpecialization( DeducedTemplateArgs->asArray(), InsertPos); assert(InvokeSpec && "Must have a corresponding static invoker specialization"); Invoker = cast<CXXMethodDecl>(InvokeSpec); } // Construct the body of the conversion function { return __invoke; }. Expr *FunctionRef = BuildDeclRefExpr(Invoker, Invoker->getType(), VK_LValue, Conv->getLocation()).get(); assert(FunctionRef && "Can't refer to __invoke function?"); Stmt *Return = BuildReturnStmt(Conv->getLocation(), FunctionRef).get(); Conv->setBody(new (Context) CompoundStmt(Context, Return, Conv->getLocation(), Conv->getLocation())); Conv->markUsed(Context); Conv->setReferenced(); // Fill in the __invoke function with a dummy implementation. IR generation // will fill in the actual details. Invoker->markUsed(Context); Invoker->setReferenced(); Invoker->setBody(new (Context) CompoundStmt(Conv->getLocation())); if (ASTMutationListener *L = getASTMutationListener()) { L->CompletedImplicitDefinition(Conv); L->CompletedImplicitDefinition(Invoker); } } void Sema::DefineImplicitLambdaToBlockPointerConversion( SourceLocation CurrentLocation, CXXConversionDecl *Conv) { assert(!Conv->getParent()->isGenericLambda()); Conv->markUsed(Context); SynthesizedFunctionScope Scope(*this, Conv); DiagnosticErrorTrap Trap(Diags); // Copy-initialize the lambda object as needed to capture it. Expr *This = ActOnCXXThis(CurrentLocation).get(); Expr *DerefThis =CreateBuiltinUnaryOp(CurrentLocation, UO_Deref, This).get(); ExprResult BuildBlock = BuildBlockForLambdaConversion(CurrentLocation, Conv->getLocation(), Conv, DerefThis); // If we're not under ARC, make sure we still get the _Block_copy/autorelease // behavior. Note that only the general conversion function does this // (since it's unusable otherwise); in the case where we inline the // block literal, it has block literal lifetime semantics. if (!BuildBlock.isInvalid() && !getLangOpts().ObjCAutoRefCount) BuildBlock = ImplicitCastExpr::Create(Context, BuildBlock.get()->getType(), CK_CopyAndAutoreleaseBlockObject, BuildBlock.get(), nullptr, VK_RValue); if (BuildBlock.isInvalid()) { Diag(CurrentLocation, diag::note_lambda_to_block_conv); Conv->setInvalidDecl(); return; } // Create the return statement that returns the block from the conversion // function. StmtResult Return = BuildReturnStmt(Conv->getLocation(), BuildBlock.get()); if (Return.isInvalid()) { Diag(CurrentLocation, diag::note_lambda_to_block_conv); Conv->setInvalidDecl(); return; } // Set the body of the conversion function. Stmt *ReturnS = Return.get(); Conv->setBody(new (Context) CompoundStmt(Context, ReturnS, Conv->getLocation(), Conv->getLocation())); // We're done; notify the mutation listener, if any. if (ASTMutationListener *L = getASTMutationListener()) { L->CompletedImplicitDefinition(Conv); } } /// \brief Determine whether the given list arguments contains exactly one /// "real" (non-default) argument. static bool hasOneRealArgument(MultiExprArg Args) { switch (Args.size()) { case 0: return false; default: if (!Args[1]->isDefaultArgument()) return false; // fall through case 1: return !Args[0]->isDefaultArgument(); } return false; } ExprResult Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType, CXXConstructorDecl *Constructor, MultiExprArg ExprArgs, bool HadMultipleCandidates, bool IsListInitialization, bool IsStdInitListInitialization, bool RequiresZeroInit, unsigned ConstructKind, SourceRange ParenRange) { bool Elidable = false; // C++0x [class.copy]p34: // When certain criteria are met, an implementation is allowed to // omit the copy/move construction of a class object, even if the // copy/move constructor and/or destructor for the object have // side effects. [...] // - when a temporary class object that has not been bound to a // reference (12.2) would be copied/moved to a class object // with the same cv-unqualified type, the copy/move operation // can be omitted by constructing the temporary object // directly into the target of the omitted copy/move if (ConstructKind == CXXConstructExpr::CK_Complete && Constructor->isCopyOrMoveConstructor() && hasOneRealArgument(ExprArgs)) { Expr *SubExpr = ExprArgs[0]; Elidable = SubExpr->isTemporaryObject(Context, Constructor->getParent()); } return BuildCXXConstructExpr(ConstructLoc, DeclInitType, Constructor, Elidable, ExprArgs, HadMultipleCandidates, IsListInitialization, IsStdInitListInitialization, RequiresZeroInit, ConstructKind, ParenRange); } /// BuildCXXConstructExpr - Creates a complete call to a constructor, /// including handling of its default argument expressions. ExprResult Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType, CXXConstructorDecl *Constructor, bool Elidable, MultiExprArg ExprArgs, bool HadMultipleCandidates, bool IsListInitialization, bool IsStdInitListInitialization, bool RequiresZeroInit, unsigned ConstructKind, SourceRange ParenRange) { MarkFunctionReferenced(ConstructLoc, Constructor); return CXXConstructExpr::Create( Context, DeclInitType, ConstructLoc, Constructor, Elidable, ExprArgs, HadMultipleCandidates, IsListInitialization, IsStdInitListInitialization, RequiresZeroInit, static_cast<CXXConstructExpr::ConstructionKind>(ConstructKind), ParenRange); } ExprResult Sema::BuildCXXDefaultInitExpr(SourceLocation Loc, FieldDecl *Field) { assert(Field->hasInClassInitializer()); // If we already have the in-class initializer nothing needs to be done. if (Field->getInClassInitializer()) return CXXDefaultInitExpr::Create(Context, Loc, Field); // Maybe we haven't instantiated the in-class initializer. Go check the // pattern FieldDecl to see if it has one. CXXRecordDecl *ParentRD = cast<CXXRecordDecl>(Field->getParent()); if (isTemplateInstantiation(ParentRD->getTemplateSpecializationKind())) { CXXRecordDecl *ClassPattern = ParentRD->getTemplateInstantiationPattern(); DeclContext::lookup_result Lookup = ClassPattern->lookup(Field->getDeclName()); assert(Lookup.size() == 1); FieldDecl *Pattern = cast<FieldDecl>(Lookup[0]); if (InstantiateInClassInitializer(Loc, Field, Pattern, getTemplateInstantiationArgs(Field))) return ExprError(); return CXXDefaultInitExpr::Create(Context, Loc, Field); } // DR1351: // If the brace-or-equal-initializer of a non-static data member // invokes a defaulted default constructor of its class or of an // enclosing class in a potentially evaluated subexpression, the // program is ill-formed. // // This resolution is unworkable: the exception specification of the // default constructor can be needed in an unevaluated context, in // particular, in the operand of a noexcept-expression, and we can be // unable to compute an exception specification for an enclosed class. // // Any attempt to resolve the exception specification of a defaulted default // constructor before the initializer is lexically complete will ultimately // come here at which point we can diagnose it. RecordDecl *OutermostClass = ParentRD->getOuterLexicalRecordContext(); if (OutermostClass == ParentRD) { Diag(Field->getLocEnd(), diag::err_in_class_initializer_not_yet_parsed) << ParentRD << Field; } else { Diag(Field->getLocEnd(), diag::err_in_class_initializer_not_yet_parsed_outer_class) << ParentRD << OutermostClass << Field; } return ExprError(); } void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) { if (VD->isInvalidDecl()) return; CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Record->getDecl()); if (ClassDecl->isInvalidDecl()) return; if (ClassDecl->hasIrrelevantDestructor()) return; if (ClassDecl->isDependentContext()) return; CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl); MarkFunctionReferenced(VD->getLocation(), Destructor); CheckDestructorAccess(VD->getLocation(), Destructor, PDiag(diag::err_access_dtor_var) << VD->getDeclName() << VD->getType()); DiagnoseUseOfDecl(Destructor, VD->getLocation()); if (Destructor->isTrivial()) return; if (!VD->hasGlobalStorage()) return; // Emit warning for non-trivial dtor in global scope (a real global, // class-static, function-static). Diag(VD->getLocation(), diag::warn_exit_time_destructor); // TODO: this should be re-enabled for static locals by !CXAAtExit if (!VD->isStaticLocal()) Diag(VD->getLocation(), diag::warn_global_destructor); } /// \brief Given a constructor and the set of arguments provided for the /// constructor, convert the arguments and add any required default arguments /// to form a proper call to this constructor. /// /// \returns true if an error occurred, false otherwise. bool Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor, MultiExprArg ArgsPtr, SourceLocation Loc, SmallVectorImpl<Expr*> &ConvertedArgs, bool AllowExplicit, bool IsListInitialization) { // FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall. unsigned NumArgs = ArgsPtr.size(); Expr **Args = ArgsPtr.data(); const FunctionProtoType *Proto = Constructor->getType()->getAs<FunctionProtoType>(); assert(Proto && "Constructor without a prototype?"); unsigned NumParams = Proto->getNumParams(); // If too few arguments are available, we'll fill in the rest with defaults. if (NumArgs < NumParams) ConvertedArgs.reserve(NumParams); else ConvertedArgs.reserve(NumArgs); VariadicCallType CallType = Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply; SmallVector<Expr *, 8> AllArgs; bool Invalid = GatherArgumentsForCall(Loc, Constructor, Proto, 0, llvm::makeArrayRef(Args, NumArgs), AllArgs, CallType, AllowExplicit, IsListInitialization); ConvertedArgs.append(AllArgs.begin(), AllArgs.end()); DiagnoseSentinelCalls(Constructor, Loc, AllArgs); CheckConstructorCall(Constructor, llvm::makeArrayRef(AllArgs.data(), AllArgs.size()), Proto, Loc); return Invalid; } static inline bool CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef, const FunctionDecl *FnDecl) { const DeclContext *DC = FnDecl->getDeclContext()->getRedeclContext(); if (isa<NamespaceDecl>(DC)) { return SemaRef.Diag(FnDecl->getLocation(), diag::err_operator_new_delete_declared_in_namespace) << FnDecl->getDeclName(); } if (isa<TranslationUnitDecl>(DC) && FnDecl->getStorageClass() == SC_Static) { return SemaRef.Diag(FnDecl->getLocation(), diag::err_operator_new_delete_declared_static) << FnDecl->getDeclName(); } return false; } static inline bool CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl, CanQualType ExpectedResultType, CanQualType ExpectedFirstParamType, unsigned DependentParamTypeDiag, unsigned InvalidParamTypeDiag) { QualType ResultType = FnDecl->getType()->getAs<FunctionType>()->getReturnType(); // Check that the result type is not dependent. if (ResultType->isDependentType()) return SemaRef.Diag(FnDecl->getLocation(), diag::err_operator_new_delete_dependent_result_type) << FnDecl->getDeclName() << ExpectedResultType; // Check that the result type is what we expect. if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType) return SemaRef.Diag(FnDecl->getLocation(), diag::err_operator_new_delete_invalid_result_type) << FnDecl->getDeclName() << ExpectedResultType; // A function template must have at least 2 parameters. if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2) return SemaRef.Diag(FnDecl->getLocation(), diag::err_operator_new_delete_template_too_few_parameters) << FnDecl->getDeclName(); // The function decl must have at least 1 parameter. if (FnDecl->getNumParams() == 0) return SemaRef.Diag(FnDecl->getLocation(), diag::err_operator_new_delete_too_few_parameters) << FnDecl->getDeclName(); // Check the first parameter type is not dependent. QualType FirstParamType = FnDecl->getParamDecl(0)->getType(); if (FirstParamType->isDependentType()) return SemaRef.Diag(FnDecl->getLocation(), DependentParamTypeDiag) << FnDecl->getDeclName() << ExpectedFirstParamType; // Check that the first parameter type is what we expect. if (SemaRef.Context.getCanonicalType(FirstParamType).getUnqualifiedType() != ExpectedFirstParamType) return SemaRef.Diag(FnDecl->getLocation(), InvalidParamTypeDiag) << FnDecl->getDeclName() << ExpectedFirstParamType; return false; } static bool CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) { // C++ [basic.stc.dynamic.allocation]p1: // A program is ill-formed if an allocation function is declared in a // namespace scope other than global scope or declared static in global // scope. if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl)) return true; CanQualType SizeTy = SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType()); // C++ [basic.stc.dynamic.allocation]p1: // The return type shall be void*. The first parameter shall have type // std::size_t. if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy, SizeTy, diag::err_operator_new_dependent_param_type, diag::err_operator_new_param_type)) return true; // C++ [basic.stc.dynamic.allocation]p1: // The first parameter shall not have an associated default argument. if (FnDecl->getParamDecl(0)->hasDefaultArg()) return SemaRef.Diag(FnDecl->getLocation(), diag::err_operator_new_default_arg) << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange(); return false; } static bool CheckOperatorDeleteDeclaration(Sema &SemaRef, FunctionDecl *FnDecl) { // C++ [basic.stc.dynamic.deallocation]p1: // A program is ill-formed if deallocation functions are declared in a // namespace scope other than global scope or declared static in global // scope. if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl)) return true; // C++ [basic.stc.dynamic.deallocation]p2: // Each deallocation function shall return void and its first parameter // shall be void*. if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidTy, SemaRef.Context.VoidPtrTy, diag::err_operator_delete_dependent_param_type, diag::err_operator_delete_param_type)) return true; return false; } /// CheckOverloadedOperatorDeclaration - Check whether the declaration /// of this overloaded operator is well-formed. If so, returns false; /// otherwise, emits appropriate diagnostics and returns true. bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) { assert(FnDecl && FnDecl->isOverloadedOperator() && "Expected an overloaded operator declaration"); OverloadedOperatorKind Op = FnDecl->getOverloadedOperator(); // C++ [over.oper]p5: // The allocation and deallocation functions, operator new, // operator new[], operator delete and operator delete[], are // described completely in 3.7.3. The attributes and restrictions // found in the rest of this subclause do not apply to them unless // explicitly stated in 3.7.3. if (Op == OO_Delete || Op == OO_Array_Delete) return CheckOperatorDeleteDeclaration(*this, FnDecl); if (Op == OO_New || Op == OO_Array_New) return CheckOperatorNewDeclaration(*this, FnDecl); // C++ [over.oper]p6: // An operator function shall either be a non-static member // function or be a non-member function and have at least one // parameter whose type is a class, a reference to a class, an // enumeration, or a reference to an enumeration. if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) { if (MethodDecl->isStatic()) return Diag(FnDecl->getLocation(), diag::err_operator_overload_static) << FnDecl->getDeclName(); } else { bool ClassOrEnumParam = false; for (auto Param : FnDecl->params()) { QualType ParamType = Param->getType().getNonReferenceType(); if (ParamType->isDependentType() || ParamType->isRecordType() || ParamType->isEnumeralType()) { ClassOrEnumParam = true; break; } } if (!ClassOrEnumParam) return Diag(FnDecl->getLocation(), diag::err_operator_overload_needs_class_or_enum) << FnDecl->getDeclName(); } // C++ [over.oper]p8: // An operator function cannot have default arguments (8.3.6), // except where explicitly stated below. // // Only the function-call operator allows default arguments // (C++ [over.call]p1). if (Op != OO_Call) { for (auto Param : FnDecl->params()) { if (Param->hasDefaultArg()) return Diag(Param->getLocation(), diag::err_operator_overload_default_arg) << FnDecl->getDeclName() << Param->getDefaultArgRange(); } } static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = { { false, false, false } #define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \ , { Unary, Binary, MemberOnly } #include "clang/Basic/OperatorKinds.def" }; bool CanBeUnaryOperator = OperatorUses[Op][0]; bool CanBeBinaryOperator = OperatorUses[Op][1]; bool MustBeMemberOperator = OperatorUses[Op][2]; // C++ [over.oper]p8: // [...] Operator functions cannot have more or fewer parameters // than the number required for the corresponding operator, as // described in the rest of this subclause. unsigned NumParams = FnDecl->getNumParams() + (isa<CXXMethodDecl>(FnDecl)? 1 : 0); if (Op != OO_Call && ((NumParams == 1 && !CanBeUnaryOperator) || (NumParams == 2 && !CanBeBinaryOperator) || (NumParams < 1) || (NumParams > 2))) { // We have the wrong number of parameters. unsigned ErrorKind; if (CanBeUnaryOperator && CanBeBinaryOperator) { ErrorKind = 2; // 2 -> unary or binary. } else if (CanBeUnaryOperator) { ErrorKind = 0; // 0 -> unary } else { assert(CanBeBinaryOperator && "All non-call overloaded operators are unary or binary!"); ErrorKind = 1; // 1 -> binary } return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be) << FnDecl->getDeclName() << NumParams << ErrorKind; } // Overloaded operators other than operator() cannot be variadic. if (Op != OO_Call && FnDecl->getType()->getAs<FunctionProtoType>()->isVariadic()) { return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic) << FnDecl->getDeclName(); } // Some operators must be non-static member functions. if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) { return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be_member) << FnDecl->getDeclName(); } // C++ [over.inc]p1: // The user-defined function called operator++ implements the // prefix and postfix ++ operator. If this function is a member // function with no parameters, or a non-member function with one // parameter of class or enumeration type, it defines the prefix // increment operator ++ for objects of that type. If the function // is a member function with one parameter (which shall be of type // int) or a non-member function with two parameters (the second // of which shall be of type int), it defines the postfix // increment operator ++ for objects of that type. if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) { ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1); QualType ParamType = LastParam->getType(); if (!ParamType->isSpecificBuiltinType(BuiltinType::Int) && !ParamType->isDependentType()) return Diag(LastParam->getLocation(), diag::err_operator_overload_post_incdec_must_be_int) << LastParam->getType() << (Op == OO_MinusMinus); } return false; } /// CheckLiteralOperatorDeclaration - Check whether the declaration /// of this literal operator function is well-formed. If so, returns /// false; otherwise, emits appropriate diagnostics and returns true. bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) { if (isa<CXXMethodDecl>(FnDecl)) { Diag(FnDecl->getLocation(), diag::err_literal_operator_outside_namespace) << FnDecl->getDeclName(); return true; } if (FnDecl->isExternC()) { Diag(FnDecl->getLocation(), diag::err_literal_operator_extern_c); return true; } bool Valid = false; // This might be the definition of a literal operator template. FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate(); // This might be a specialization of a literal operator template. if (!TpDecl) TpDecl = FnDecl->getPrimaryTemplate(); // template <char...> type operator "" name() and // template <class T, T...> type operator "" name() are the only valid // template signatures, and the only valid signatures with no parameters. if (TpDecl) { if (FnDecl->param_size() == 0) { // Must have one or two template parameters TemplateParameterList *Params = TpDecl->getTemplateParameters(); if (Params->size() == 1) { NonTypeTemplateParmDecl *PmDecl = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(0)); // The template parameter must be a char parameter pack. if (PmDecl && PmDecl->isTemplateParameterPack() && Context.hasSameType(PmDecl->getType(), Context.CharTy)) Valid = true; } else if (Params->size() == 2) { TemplateTypeParmDecl *PmType = dyn_cast<TemplateTypeParmDecl>(Params->getParam(0)); NonTypeTemplateParmDecl *PmArgs = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(1)); // The second template parameter must be a parameter pack with the // first template parameter as its type. if (PmType && PmArgs && !PmType->isTemplateParameterPack() && PmArgs->isTemplateParameterPack()) { const TemplateTypeParmType *TArgs = PmArgs->getType()->getAs<TemplateTypeParmType>(); if (TArgs && TArgs->getDepth() == PmType->getDepth() && TArgs->getIndex() == PmType->getIndex()) { Valid = true; if (ActiveTemplateInstantiations.empty()) Diag(FnDecl->getLocation(), diag::ext_string_literal_operator_template); } } } } } else if (FnDecl->param_size()) { // Check the first parameter FunctionDecl::param_iterator Param = FnDecl->param_begin(); QualType T = (*Param)->getType().getUnqualifiedType(); // unsigned long long int, long double, and any character type are allowed // as the only parameters. if (Context.hasSameType(T, Context.UnsignedLongLongTy) || Context.hasSameType(T, Context.LongDoubleTy) || Context.hasSameType(T, Context.CharTy) || Context.hasSameType(T, Context.WideCharTy) || Context.hasSameType(T, Context.Char16Ty) || Context.hasSameType(T, Context.Char32Ty)) { if (++Param == FnDecl->param_end()) Valid = true; goto FinishedParams; } // Otherwise it must be a pointer to const; let's strip those qualifiers. const PointerType *PT = T->getAs<PointerType>(); if (!PT) goto FinishedParams; T = PT->getPointeeType(); if (!T.isConstQualified() || T.isVolatileQualified()) goto FinishedParams; T = T.getUnqualifiedType(); // Move on to the second parameter; ++Param; // If there is no second parameter, the first must be a const char * if (Param == FnDecl->param_end()) { if (Context.hasSameType(T, Context.CharTy)) Valid = true; goto FinishedParams; } // const char *, const wchar_t*, const char16_t*, and const char32_t* // are allowed as the first parameter to a two-parameter function if (!(Context.hasSameType(T, Context.CharTy) || Context.hasSameType(T, Context.WideCharTy) || Context.hasSameType(T, Context.Char16Ty) || Context.hasSameType(T, Context.Char32Ty))) goto FinishedParams; // The second and final parameter must be an std::size_t T = (*Param)->getType().getUnqualifiedType(); if (Context.hasSameType(T, Context.getSizeType()) && ++Param == FnDecl->param_end()) Valid = true; } // FIXME: This diagnostic is absolutely terrible. FinishedParams: if (!Valid) { Diag(FnDecl->getLocation(), diag::err_literal_operator_params) << FnDecl->getDeclName(); return true; } // A parameter-declaration-clause containing a default argument is not // equivalent to any of the permitted forms. for (auto Param : FnDecl->params()) { if (Param->hasDefaultArg()) { Diag(Param->getDefaultArgRange().getBegin(), diag::err_literal_operator_default_argument) << Param->getDefaultArgRange(); break; } } StringRef LiteralName = FnDecl->getDeclName().getCXXLiteralIdentifier()->getName(); if (LiteralName[0] != '_') { // C++11 [usrlit.suffix]p1: // Literal suffix identifiers that do not start with an underscore // are reserved for future standardization. Diag(FnDecl->getLocation(), diag::warn_user_literal_reserved) << NumericLiteralParser::isValidUDSuffix(getLangOpts(), LiteralName); } return false; } /// ActOnStartLinkageSpecification - Parsed the beginning of a C++ /// linkage specification, including the language and (if present) /// the '{'. ExternLoc is the location of the 'extern', Lang is the /// language string literal. LBraceLoc, if valid, provides the location of /// the '{' brace. Otherwise, this linkage specification does not /// have any braces. Decl *Sema::ActOnStartLinkageSpecification(Scope *S, SourceLocation ExternLoc, Expr *LangStr, SourceLocation LBraceLoc) { StringLiteral *Lit = cast<StringLiteral>(LangStr); if (!Lit->isAscii()) { Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_not_ascii) << LangStr->getSourceRange(); return nullptr; } StringRef Lang = Lit->getString(); LinkageSpecDecl::LanguageIDs Language; if (Lang == "C") Language = LinkageSpecDecl::lang_c; else if (Lang == "C++") Language = LinkageSpecDecl::lang_cxx; else { Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_unknown) << LangStr->getSourceRange(); return nullptr; } // FIXME: Add all the various semantics of linkage specifications LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext, ExternLoc, LangStr->getExprLoc(), Language, LBraceLoc.isValid()); CurContext->addDecl(D); PushDeclContext(S, D); return D; } /// ActOnFinishLinkageSpecification - Complete the definition of /// the C++ linkage specification LinkageSpec. If RBraceLoc is /// valid, it's the position of the closing '}' brace in a linkage /// specification that uses braces. Decl *Sema::ActOnFinishLinkageSpecification(Scope *S, Decl *LinkageSpec, SourceLocation RBraceLoc) { if (RBraceLoc.isValid()) { LinkageSpecDecl* LSDecl = cast<LinkageSpecDecl>(LinkageSpec); LSDecl->setRBraceLoc(RBraceLoc); } PopDeclContext(); return LinkageSpec; } Decl *Sema::ActOnEmptyDeclaration(Scope *S, AttributeList *AttrList, SourceLocation SemiLoc) { Decl *ED = EmptyDecl::Create(Context, CurContext, SemiLoc); // Attribute declarations appertain to empty declaration so we handle // them here. if (AttrList) ProcessDeclAttributeList(S, ED, AttrList); CurContext->addDecl(ED); return ED; } /// \brief Perform semantic analysis for the variable declaration that /// occurs within a C++ catch clause, returning the newly-created /// variable. VarDecl *Sema::BuildExceptionDeclaration(Scope *S, TypeSourceInfo *TInfo, SourceLocation StartLoc, SourceLocation Loc, IdentifierInfo *Name) { bool Invalid = false; QualType ExDeclType = TInfo->getType(); // Arrays and functions decay. if (ExDeclType->isArrayType()) ExDeclType = Context.getArrayDecayedType(ExDeclType); else if (ExDeclType->isFunctionType()) ExDeclType = Context.getPointerType(ExDeclType); // C++ 15.3p1: The exception-declaration shall not denote an incomplete type. // The exception-declaration shall not denote a pointer or reference to an // incomplete type, other than [cv] void*. // N2844 forbids rvalue references. if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) { Diag(Loc, diag::err_catch_rvalue_ref); Invalid = true; } QualType BaseType = ExDeclType; int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference unsigned DK = diag::err_catch_incomplete; if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { BaseType = Ptr->getPointeeType(); Mode = 1; DK = diag::err_catch_incomplete_ptr; } else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) { // For the purpose of error recovery, we treat rvalue refs like lvalue refs. BaseType = Ref->getPointeeType(); Mode = 2; DK = diag::err_catch_incomplete_ref; } if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) && !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK)) Invalid = true; if (!Invalid && !ExDeclType->isDependentType() && RequireNonAbstractType(Loc, ExDeclType, diag::err_abstract_type_in_decl, AbstractVariableType)) Invalid = true; // Only the non-fragile NeXT runtime currently supports C++ catches // of ObjC types, and no runtime supports catching ObjC types by value. if (!Invalid && getLangOpts().ObjC1) { QualType T = ExDeclType; if (const ReferenceType *RT = T->getAs<ReferenceType>()) T = RT->getPointeeType(); if (T->isObjCObjectType()) { Diag(Loc, diag::err_objc_object_catch); Invalid = true; } else if (T->isObjCObjectPointerType()) { // FIXME: should this be a test for macosx-fragile specifically? if (getLangOpts().ObjCRuntime.isFragile()) Diag(Loc, diag::warn_objc_pointer_cxx_catch_fragile); } } VarDecl *ExDecl = VarDecl::Create(Context, CurContext, StartLoc, Loc, Name, ExDeclType, TInfo, SC_None); ExDecl->setExceptionVariable(true); // In ARC, infer 'retaining' for variables of retainable type. if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(ExDecl)) Invalid = true; if (!Invalid && !ExDeclType->isDependentType()) { if (const RecordType *recordType = ExDeclType->getAs<RecordType>()) { // Insulate this from anything else we might currently be parsing. EnterExpressionEvaluationContext scope(*this, PotentiallyEvaluated); // C++ [except.handle]p16: // The object declared in an exception-declaration or, if the // exception-declaration does not specify a name, a temporary (12.2) is // copy-initialized (8.5) from the exception object. [...] // The object is destroyed when the handler exits, after the destruction // of any automatic objects initialized within the handler. // // We just pretend to initialize the object with itself, then make sure // it can be destroyed later. QualType initType = Context.getExceptionObjectType(ExDeclType); InitializedEntity entity = InitializedEntity::InitializeVariable(ExDecl); InitializationKind initKind = InitializationKind::CreateCopy(Loc, SourceLocation()); Expr *opaqueValue = new (Context) OpaqueValueExpr(Loc, initType, VK_LValue, OK_Ordinary); InitializationSequence sequence(*this, entity, initKind, opaqueValue); ExprResult result = sequence.Perform(*this, entity, initKind, opaqueValue); if (result.isInvalid()) Invalid = true; else { // If the constructor used was non-trivial, set this as the // "initializer". CXXConstructExpr *construct = result.getAs<CXXConstructExpr>(); if (!construct->getConstructor()->isTrivial()) { Expr *init = MaybeCreateExprWithCleanups(construct); ExDecl->setInit(init); } // And make sure it's destructable. FinalizeVarWithDestructor(ExDecl, recordType); } } } if (Invalid) ExDecl->setInvalidDecl(); return ExDecl; } /// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch /// handler. Decl *Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) { TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); bool Invalid = D.isInvalidType(); // Check for unexpanded parameter packs. if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo, UPPC_ExceptionType)) { TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy, D.getIdentifierLoc()); Invalid = true; } IdentifierInfo *II = D.getIdentifier(); if (NamedDecl *PrevDecl = LookupSingleName(S, II, D.getIdentifierLoc(), LookupOrdinaryName, ForRedeclaration)) { // The scope should be freshly made just for us. There is just no way // it contains any previous declaration, except for function parameters in // a function-try-block's catch statement. assert(!S->isDeclScope(PrevDecl)); if (isDeclInScope(PrevDecl, CurContext, S)) { Diag(D.getIdentifierLoc(), diag::err_redefinition) << D.getIdentifier(); Diag(PrevDecl->getLocation(), diag::note_previous_definition); Invalid = true; } else if (PrevDecl->isTemplateParameter()) // Maybe we will complain about the shadowed template parameter. DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); } if (D.getCXXScopeSpec().isSet() && !Invalid) { Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator) << D.getCXXScopeSpec().getRange(); Invalid = true; } VarDecl *ExDecl = BuildExceptionDeclaration(S, TInfo, D.getLocStart(), D.getIdentifierLoc(), D.getIdentifier()); if (Invalid) ExDecl->setInvalidDecl(); // Add the exception declaration into this scope. if (II) PushOnScopeChains(ExDecl, S); else CurContext->addDecl(ExDecl); ProcessDeclAttributes(S, ExDecl, D); return ExDecl; } Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc, Expr *AssertExpr, Expr *AssertMessageExpr, SourceLocation RParenLoc) { StringLiteral *AssertMessage = AssertMessageExpr ? cast<StringLiteral>(AssertMessageExpr) : nullptr; if (DiagnoseUnexpandedParameterPack(AssertExpr, UPPC_StaticAssertExpression)) return nullptr; return BuildStaticAssertDeclaration(StaticAssertLoc, AssertExpr, AssertMessage, RParenLoc, false); } Decl *Sema::BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc, Expr *AssertExpr, StringLiteral *AssertMessage, SourceLocation RParenLoc, bool Failed) { assert(AssertExpr != nullptr && "Expected non-null condition"); if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent() && !Failed) { // In a static_assert-declaration, the constant-expression shall be a // constant expression that can be contextually converted to bool. ExprResult Converted = PerformContextuallyConvertToBool(AssertExpr); if (Converted.isInvalid()) Failed = true; llvm::APSInt Cond; if (!Failed && VerifyIntegerConstantExpression(Converted.get(), &Cond, diag::err_static_assert_expression_is_not_constant, /*AllowFold=*/false).isInvalid()) Failed = true; if (!Failed && !Cond) { SmallString<256> MsgBuffer; llvm::raw_svector_ostream Msg(MsgBuffer); if (AssertMessage) AssertMessage->printPretty(Msg, nullptr, getPrintingPolicy()); Diag(StaticAssertLoc, diag::err_static_assert_failed) << !AssertMessage << Msg.str() << AssertExpr->getSourceRange(); Failed = true; } } Decl *Decl = StaticAssertDecl::Create(Context, CurContext, StaticAssertLoc, AssertExpr, AssertMessage, RParenLoc, Failed); CurContext->addDecl(Decl); return Decl; } /// \brief Perform semantic analysis of the given friend type declaration. /// /// \returns A friend declaration that. FriendDecl *Sema::CheckFriendTypeDecl(SourceLocation LocStart, SourceLocation FriendLoc, TypeSourceInfo *TSInfo) { assert(TSInfo && "NULL TypeSourceInfo for friend type declaration"); QualType T = TSInfo->getType(); SourceRange TypeRange = TSInfo->getTypeLoc().getLocalSourceRange(); // C++03 [class.friend]p2: // An elaborated-type-specifier shall be used in a friend declaration // for a class.* // // * The class-key of the elaborated-type-specifier is required. if (!ActiveTemplateInstantiations.empty()) { // Do not complain about the form of friend template types during // template instantiation; we will already have complained when the // template was declared. } else { if (!T->isElaboratedTypeSpecifier()) { // If we evaluated the type to a record type, suggest putting // a tag in front. if (const RecordType *RT = T->getAs<RecordType>()) { RecordDecl *RD = RT->getDecl(); SmallString<16> InsertionText(" "); InsertionText += RD->getKindName(); Diag(TypeRange.getBegin(), getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_unelaborated_friend_type : diag::ext_unelaborated_friend_type) << (unsigned) RD->getTagKind() << T << FixItHint::CreateInsertion(getLocForEndOfToken(FriendLoc), InsertionText); } else { Diag(FriendLoc, getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_nonclass_type_friend : diag::ext_nonclass_type_friend) << T << TypeRange; } } else if (T->getAs<EnumType>()) { Diag(FriendLoc, getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_enum_friend : diag::ext_enum_friend) << T << TypeRange; } // C++11 [class.friend]p3: // A friend declaration that does not declare a function shall have one // of the following forms: // friend elaborated-type-specifier ; // friend simple-type-specifier ; // friend typename-specifier ; if (getLangOpts().CPlusPlus11 && LocStart != FriendLoc) Diag(FriendLoc, diag::err_friend_not_first_in_declaration) << T; } // If the type specifier in a friend declaration designates a (possibly // cv-qualified) class type, that class is declared as a friend; otherwise, // the friend declaration is ignored. return FriendDecl::Create(Context, CurContext, TSInfo->getTypeLoc().getLocStart(), TSInfo, FriendLoc); } /// Handle a friend tag declaration where the scope specifier was /// templated. Decl *Sema::ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc, unsigned TagSpec, SourceLocation TagLoc, CXXScopeSpec &SS, IdentifierInfo *Name, SourceLocation NameLoc, AttributeList *Attr, MultiTemplateParamsArg TempParamLists) { TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); bool isExplicitSpecialization = false; bool Invalid = false; if (TemplateParameterList *TemplateParams = MatchTemplateParametersToScopeSpecifier( TagLoc, NameLoc, SS, nullptr, TempParamLists, /*friend*/ true, isExplicitSpecialization, Invalid)) { if (TemplateParams->size() > 0) { // This is a declaration of a class template. if (Invalid) return nullptr; return CheckClassTemplate(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc, Attr, TemplateParams, AS_public, /*ModulePrivateLoc=*/SourceLocation(), FriendLoc, TempParamLists.size() - 1, TempParamLists.data()).get(); } else { // The "template<>" header is extraneous. Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams) << TypeWithKeyword::getTagTypeKindName(Kind) << Name; isExplicitSpecialization = true; } } if (Invalid) return nullptr; bool isAllExplicitSpecializations = true; for (unsigned I = TempParamLists.size(); I-- > 0; ) { if (TempParamLists[I]->size()) { isAllExplicitSpecializations = false; break; } } // FIXME: don't ignore attributes. // If it's explicit specializations all the way down, just forget // about the template header and build an appropriate non-templated // friend. TODO: for source fidelity, remember the headers. if (isAllExplicitSpecializations) { if (SS.isEmpty()) { bool Owned = false; bool IsDependent = false; return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc, Attr, AS_public, /*ModulePrivateLoc=*/SourceLocation(), MultiTemplateParamsArg(), Owned, IsDependent, /*ScopedEnumKWLoc=*/SourceLocation(), /*ScopedEnumUsesClassTag=*/false, /*UnderlyingType=*/TypeResult(), /*IsTypeSpecifier=*/false); } NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context); ElaboratedTypeKeyword Keyword = TypeWithKeyword::getKeywordForTagTypeKind(Kind); QualType T = CheckTypenameType(Keyword, TagLoc, QualifierLoc, *Name, NameLoc); if (T.isNull()) return nullptr; TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); if (isa<DependentNameType>(T)) { DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>(); TL.setElaboratedKeywordLoc(TagLoc); TL.setQualifierLoc(QualifierLoc); TL.setNameLoc(NameLoc); } else { ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>(); TL.setElaboratedKeywordLoc(TagLoc); TL.setQualifierLoc(QualifierLoc); TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(NameLoc); } FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc, TSI, FriendLoc, TempParamLists); Friend->setAccess(AS_public); CurContext->addDecl(Friend); return Friend; } assert(SS.isNotEmpty() && "valid templated tag with no SS and no direct?"); // Handle the case of a templated-scope friend class. e.g. // template <class T> class A<T>::B; // FIXME: we don't support these right now. Diag(NameLoc, diag::warn_template_qualified_friend_unsupported) << SS.getScopeRep() << SS.getRange() << cast<CXXRecordDecl>(CurContext); ElaboratedTypeKeyword ETK = TypeWithKeyword::getKeywordForTagTypeKind(Kind); QualType T = Context.getDependentNameType(ETK, SS.getScopeRep(), Name); TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>(); TL.setElaboratedKeywordLoc(TagLoc); TL.setQualifierLoc(SS.getWithLocInContext(Context)); TL.setNameLoc(NameLoc); FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc, TSI, FriendLoc, TempParamLists); Friend->setAccess(AS_public); Friend->setUnsupportedFriend(true); CurContext->addDecl(Friend); return Friend; } /// Handle a friend type declaration. This works in tandem with /// ActOnTag. /// /// Notes on friend class templates: /// /// We generally treat friend class declarations as if they were /// declaring a class. So, for example, the elaborated type specifier /// in a friend declaration is required to obey the restrictions of a /// class-head (i.e. no typedefs in the scope chain), template /// parameters are required to match up with simple template-ids, &c. /// However, unlike when declaring a template specialization, it's /// okay to refer to a template specialization without an empty /// template parameter declaration, e.g. /// friend class A<T>::B<unsigned>; /// We permit this as a special case; if there are any template /// parameters present at all, require proper matching, i.e. /// template <> template \<class T> friend class A<int>::B; Decl *Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS, MultiTemplateParamsArg TempParams) { SourceLocation Loc = DS.getLocStart(); assert(DS.isFriendSpecified()); assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified); // Try to convert the decl specifier to a type. This works for // friend templates because ActOnTag never produces a ClassTemplateDecl // for a TUK_Friend. Declarator TheDeclarator(DS, Declarator::MemberContext); TypeSourceInfo *TSI = GetTypeForDeclarator(TheDeclarator, S); QualType T = TSI->getType(); if (TheDeclarator.isInvalidType()) return nullptr; if (DiagnoseUnexpandedParameterPack(Loc, TSI, UPPC_FriendDeclaration)) return nullptr; // This is definitely an error in C++98. It's probably meant to // be forbidden in C++0x, too, but the specification is just // poorly written. // // The problem is with declarations like the following: // template <T> friend A<T>::foo; // where deciding whether a class C is a friend or not now hinges // on whether there exists an instantiation of A that causes // 'foo' to equal C. There are restrictions on class-heads // (which we declare (by fiat) elaborated friend declarations to // be) that makes this tractable. // // FIXME: handle "template <> friend class A<T>;", which // is possibly well-formed? Who even knows? if (TempParams.size() && !T->isElaboratedTypeSpecifier()) { Diag(Loc, diag::err_tagless_friend_type_template) << DS.getSourceRange(); return nullptr; } // C++98 [class.friend]p1: A friend of a class is a function // or class that is not a member of the class . . . // This is fixed in DR77, which just barely didn't make the C++03 // deadline. It's also a very silly restriction that seriously // affects inner classes and which nobody else seems to implement; // thus we never diagnose it, not even in -pedantic. // // But note that we could warn about it: it's always useless to // friend one of your own members (it's not, however, worthless to // friend a member of an arbitrary specialization of your template). Decl *D; if (unsigned NumTempParamLists = TempParams.size()) D = FriendTemplateDecl::Create(Context, CurContext, Loc, NumTempParamLists, TempParams.data(), TSI, DS.getFriendSpecLoc()); else D = CheckFriendTypeDecl(Loc, DS.getFriendSpecLoc(), TSI); if (!D) return nullptr; D->setAccess(AS_public); CurContext->addDecl(D); return D; } NamedDecl *Sema::ActOnFriendFunctionDecl(Scope *S, Declarator &D, MultiTemplateParamsArg TemplateParams) { const DeclSpec &DS = D.getDeclSpec(); assert(DS.isFriendSpecified()); assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified); SourceLocation Loc = D.getIdentifierLoc(); TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); // C++ [class.friend]p1 // A friend of a class is a function or class.... // Note that this sees through typedefs, which is intended. // It *doesn't* see through dependent types, which is correct // according to [temp.arg.type]p3: // If a declaration acquires a function type through a // type dependent on a template-parameter and this causes // a declaration that does not use the syntactic form of a // function declarator to have a function type, the program // is ill-formed. if (!TInfo->getType()->isFunctionType()) { Diag(Loc, diag::err_unexpected_friend); // It might be worthwhile to try to recover by creating an // appropriate declaration. return nullptr; } // C++ [namespace.memdef]p3 // - If a friend declaration in a non-local class first declares a // class or function, the friend class or function is a member // of the innermost enclosing namespace. // - The name of the friend is not found by simple name lookup // until a matching declaration is provided in that namespace // scope (either before or after the class declaration granting // friendship). // - If a friend function is called, its name may be found by the // name lookup that considers functions from namespaces and // classes associated with the types of the function arguments. // - When looking for a prior declaration of a class or a function // declared as a friend, scopes outside the innermost enclosing // namespace scope are not considered. CXXScopeSpec &SS = D.getCXXScopeSpec(); DeclarationNameInfo NameInfo = GetNameForDeclarator(D); DeclarationName Name = NameInfo.getName(); assert(Name); // Check for unexpanded parameter packs. if (DiagnoseUnexpandedParameterPack(Loc, TInfo, UPPC_FriendDeclaration) || DiagnoseUnexpandedParameterPack(NameInfo, UPPC_FriendDeclaration) || DiagnoseUnexpandedParameterPack(SS, UPPC_FriendDeclaration)) return nullptr; // The context we found the declaration in, or in which we should // create the declaration. DeclContext *DC; Scope *DCScope = S; LookupResult Previous(*this, NameInfo, LookupOrdinaryName, ForRedeclaration); // There are five cases here. // - There's no scope specifier and we're in a local class. Only look // for functions declared in the immediately-enclosing block scope. // We recover from invalid scope qualifiers as if they just weren't there. FunctionDecl *FunctionContainingLocalClass = nullptr; if ((SS.isInvalid() || !SS.isSet()) && (FunctionContainingLocalClass = cast<CXXRecordDecl>(CurContext)->isLocalClass())) { // 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. For a friend function // declaration, if there is no prior declaration, the program is // ill-formed. // Find the innermost enclosing non-class scope. This is the block // scope containing the local class definition (or for a nested class, // the outer local class). DCScope = S->getFnParent(); // Look up the function name in the scope. Previous.clear(LookupLocalFriendName); LookupName(Previous, S, /*AllowBuiltinCreation*/false); if (!Previous.empty()) { // All possible previous declarations must have the same context: // either they were declared at block scope or they are members of // one of the enclosing local classes. DC = Previous.getRepresentativeDecl()->getDeclContext(); } else { // This is ill-formed, but provide the context that we would have // declared the function in, if we were permitted to, for error recovery. DC = FunctionContainingLocalClass; } adjustContextForLocalExternDecl(DC); // C++ [class.friend]p6: // A function can be defined in a friend declaration of a class if and // only if the class is a non-local class (9.8), the function name is // unqualified, and the function has namespace scope. if (D.isFunctionDefinition()) { Diag(NameInfo.getBeginLoc(), diag::err_friend_def_in_local_class); } // - There's no scope specifier, in which case we just go to the // appropriate scope and look for a function or function template // there as appropriate. } else if (SS.isInvalid() || !SS.isSet()) { // C++11 [namespace.memdef]p3: // If the name in a friend declaration is neither qualified nor // a template-id and the declaration is a function or an // elaborated-type-specifier, the lookup to determine whether // the entity has been previously declared shall not consider // any scopes outside the innermost enclosing namespace. bool isTemplateId = D.getName().getKind() == UnqualifiedId::IK_TemplateId; // Find the appropriate context according to the above. DC = CurContext; // Skip class contexts. If someone can cite chapter and verse // for this behavior, that would be nice --- it's what GCC and // EDG do, and it seems like a reasonable intent, but the spec // really only says that checks for unqualified existing // declarations should stop at the nearest enclosing namespace, // not that they should only consider the nearest enclosing // namespace. while (DC->isRecord()) DC = DC->getParent(); DeclContext *LookupDC = DC; while (LookupDC->isTransparentContext()) LookupDC = LookupDC->getParent(); while (true) { LookupQualifiedName(Previous, LookupDC); if (!Previous.empty()) { DC = LookupDC; break; } if (isTemplateId) { if (isa<TranslationUnitDecl>(LookupDC)) break; } else { if (LookupDC->isFileContext()) break; } LookupDC = LookupDC->getParent(); } DCScope = getScopeForDeclContext(S, DC); // - There's a non-dependent scope specifier, in which case we // compute it and do a previous lookup there for a function // or function template. } else if (!SS.getScopeRep()->isDependent()) { DC = computeDeclContext(SS); if (!DC) return nullptr; if (RequireCompleteDeclContext(SS, DC)) return nullptr; LookupQualifiedName(Previous, DC); // Ignore things found implicitly in the wrong scope. // TODO: better diagnostics for this case. Suggesting the right // qualified scope would be nice... LookupResult::Filter F = Previous.makeFilter(); while (F.hasNext()) { NamedDecl *D = F.next(); if (!DC->InEnclosingNamespaceSetOf( D->getDeclContext()->getRedeclContext())) F.erase(); } F.done(); if (Previous.empty()) { D.setInvalidType(); Diag(Loc, diag::err_qualified_friend_not_found) << Name << TInfo->getType(); return nullptr; } // C++ [class.friend]p1: A friend of a class is a function or // class that is not a member of the class . . . if (DC->Equals(CurContext)) Diag(DS.getFriendSpecLoc(), getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_friend_is_member : diag::err_friend_is_member); if (D.isFunctionDefinition()) { // C++ [class.friend]p6: // A function can be defined in a friend declaration of a class if and // only if the class is a non-local class (9.8), the function name is // unqualified, and the function has namespace scope. SemaDiagnosticBuilder DB = Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def); DB << SS.getScopeRep(); if (DC->isFileContext()) DB << FixItHint::CreateRemoval(SS.getRange()); SS.clear(); } // - There's a scope specifier that does not match any template // parameter lists, in which case we use some arbitrary context, // create a method or method template, and wait for instantiation. // - There's a scope specifier that does match some template // parameter lists, which we don't handle right now. } else { if (D.isFunctionDefinition()) { // C++ [class.friend]p6: // A function can be defined in a friend declaration of a class if and // only if the class is a non-local class (9.8), the function name is // unqualified, and the function has namespace scope. Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def) << SS.getScopeRep(); } DC = CurContext; assert(isa<CXXRecordDecl>(DC) && "friend declaration not in class?"); } if (!DC->isRecord()) { int DiagArg = -1; switch (D.getName().getKind()) { case UnqualifiedId::IK_ConstructorTemplateId: case UnqualifiedId::IK_ConstructorName: DiagArg = 0; break; case UnqualifiedId::IK_DestructorName: DiagArg = 1; break; case UnqualifiedId::IK_ConversionFunctionId: DiagArg = 2; break; case UnqualifiedId::IK_Identifier: case UnqualifiedId::IK_ImplicitSelfParam: case UnqualifiedId::IK_LiteralOperatorId: case UnqualifiedId::IK_OperatorFunctionId: case UnqualifiedId::IK_TemplateId: break; } // This implies that it has to be an operator or function. if (DiagArg >= 0) { Diag(Loc, diag::err_introducing_special_friend) << DiagArg; return nullptr; } } // FIXME: This is an egregious hack to cope with cases where the scope stack // does not contain the declaration context, i.e., in an out-of-line // definition of a class. Scope FakeDCScope(S, Scope::DeclScope, Diags); if (!DCScope) { FakeDCScope.setEntity(DC); DCScope = &FakeDCScope; } bool AddToScope = true; NamedDecl *ND = ActOnFunctionDeclarator(DCScope, D, DC, TInfo, Previous, TemplateParams, AddToScope); if (!ND) return nullptr; assert(ND->getLexicalDeclContext() == CurContext); // If we performed typo correction, we might have added a scope specifier // and changed the decl context. DC = ND->getDeclContext(); // Add the function declaration to the appropriate lookup tables, // adjusting the redeclarations list as necessary. We don't // want to do this yet if the friending class is dependent. // // Also update the scope-based lookup if the target context's // lookup context is in lexical scope. if (!CurContext->isDependentContext()) { DC = DC->getRedeclContext(); DC->makeDeclVisibleInContext(ND); if (Scope *EnclosingScope = getScopeForDeclContext(S, DC)) PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false); } FriendDecl *FrD = FriendDecl::Create(Context, CurContext, D.getIdentifierLoc(), ND, DS.getFriendSpecLoc()); FrD->setAccess(AS_public); CurContext->addDecl(FrD); if (ND->isInvalidDecl()) { FrD->setInvalidDecl(); } else { if (DC->isRecord()) CheckFriendAccess(ND); FunctionDecl *FD; if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) FD = FTD->getTemplatedDecl(); else FD = cast<FunctionDecl>(ND); // C++11 [dcl.fct.default]p4: If a friend declaration specifies a // default argument expression, that declaration shall be a definition // and shall be the only declaration of the function or function // template in the translation unit. if (functionDeclHasDefaultArgument(FD)) { if (FunctionDecl *OldFD = FD->getPreviousDecl()) { Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_redeclared); Diag(OldFD->getLocation(), diag::note_previous_declaration); } else if (!D.isFunctionDefinition()) Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_must_be_def); } // Mark templated-scope function declarations as unsupported. if (FD->getNumTemplateParameterLists() && SS.isValid()) { Diag(FD->getLocation(), diag::warn_template_qualified_friend_unsupported) << SS.getScopeRep() << SS.getRange() << cast<CXXRecordDecl>(CurContext); FrD->setUnsupportedFriend(true); } } return ND; } void Sema::SetDeclDeleted(Decl *Dcl, SourceLocation DelLoc) { AdjustDeclIfTemplate(Dcl); FunctionDecl *Fn = dyn_cast_or_null<FunctionDecl>(Dcl); if (!Fn) { Diag(DelLoc, diag::err_deleted_non_function); return; } if (const FunctionDecl *Prev = Fn->getPreviousDecl()) { // Don't consider the implicit declaration we generate for explicit // specializations. FIXME: Do not generate these implicit declarations. if ((Prev->getTemplateSpecializationKind() != TSK_ExplicitSpecialization || Prev->getPreviousDecl()) && !Prev->isDefined()) { Diag(DelLoc, diag::err_deleted_decl_not_first); Diag(Prev->getLocation().isInvalid() ? DelLoc : Prev->getLocation(), Prev->isImplicit() ? diag::note_previous_implicit_declaration : diag::note_previous_declaration); } // If the declaration wasn't the first, we delete the function anyway for // recovery. Fn = Fn->getCanonicalDecl(); } // dllimport/dllexport cannot be deleted. if (const InheritableAttr *DLLAttr = getDLLAttr(Fn)) { Diag(Fn->getLocation(), diag::err_attribute_dll_deleted) << DLLAttr; Fn->setInvalidDecl(); } if (Fn->isDeleted()) return; // See if we're deleting a function which is already known to override a // non-deleted virtual function. if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Fn)) { bool IssuedDiagnostic = false; for (CXXMethodDecl::method_iterator I = MD->begin_overridden_methods(), E = MD->end_overridden_methods(); I != E; ++I) { if (!(*MD->begin_overridden_methods())->isDeleted()) { if (!IssuedDiagnostic) { Diag(DelLoc, diag::err_deleted_override) << MD->getDeclName(); IssuedDiagnostic = true; } Diag((*I)->getLocation(), diag::note_overridden_virtual_function); } } } // C++11 [basic.start.main]p3: // A program that defines main as deleted [...] is ill-formed. if (Fn->isMain()) Diag(DelLoc, diag::err_deleted_main); Fn->setDeletedAsWritten(); } void Sema::SetDeclDefaulted(Decl *Dcl, SourceLocation DefaultLoc) { CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Dcl); if (MD) { if (MD->getParent()->isDependentType()) { MD->setDefaulted(); MD->setExplicitlyDefaulted(); return; } CXXSpecialMember Member = getSpecialMember(MD); if (Member == CXXInvalid) { if (!MD->isInvalidDecl()) Diag(DefaultLoc, diag::err_default_special_members); return; } MD->setDefaulted(); MD->setExplicitlyDefaulted(); // If this definition appears within the record, do the checking when // the record is complete. const FunctionDecl *Primary = MD; if (const FunctionDecl *Pattern = MD->getTemplateInstantiationPattern()) // Find the uninstantiated declaration that actually had the '= default' // on it. Pattern->isDefined(Primary); // If the method was defaulted on its first declaration, we will have // already performed the checking in CheckCompletedCXXClass. Such a // declaration doesn't trigger an implicit definition. if (Primary == Primary->getCanonicalDecl()) return; CheckExplicitlyDefaultedSpecialMember(MD); if (MD->isInvalidDecl()) return; switch (Member) { case CXXDefaultConstructor: DefineImplicitDefaultConstructor(DefaultLoc, cast<CXXConstructorDecl>(MD)); break; case CXXCopyConstructor: DefineImplicitCopyConstructor(DefaultLoc, cast<CXXConstructorDecl>(MD)); break; case CXXCopyAssignment: DefineImplicitCopyAssignment(DefaultLoc, MD); break; case CXXDestructor: DefineImplicitDestructor(DefaultLoc, cast<CXXDestructorDecl>(MD)); break; case CXXMoveConstructor: DefineImplicitMoveConstructor(DefaultLoc, cast<CXXConstructorDecl>(MD)); break; case CXXMoveAssignment: DefineImplicitMoveAssignment(DefaultLoc, MD); break; case CXXInvalid: llvm_unreachable("Invalid special member."); } } else { Diag(DefaultLoc, diag::err_default_special_members); } } static void SearchForReturnInStmt(Sema &Self, Stmt *S) { for (Stmt *SubStmt : S->children()) { if (!SubStmt) continue; if (isa<ReturnStmt>(SubStmt)) Self.Diag(SubStmt->getLocStart(), diag::err_return_in_constructor_handler); if (!isa<Expr>(SubStmt)) SearchForReturnInStmt(Self, SubStmt); } } void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) { for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) { CXXCatchStmt *Handler = TryBlock->getHandler(I); SearchForReturnInStmt(*this, Handler); } } bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New, const CXXMethodDecl *Old) { const FunctionType *NewFT = New->getType()->getAs<FunctionType>(); const FunctionType *OldFT = Old->getType()->getAs<FunctionType>(); CallingConv NewCC = NewFT->getCallConv(), OldCC = OldFT->getCallConv(); // If the calling conventions match, everything is fine if (NewCC == OldCC) return false; // If the calling conventions mismatch because the new function is static, // suppress the calling convention mismatch error; the error about static // function override (err_static_overrides_virtual from // Sema::CheckFunctionDeclaration) is more clear. if (New->getStorageClass() == SC_Static) return false; Diag(New->getLocation(), diag::err_conflicting_overriding_cc_attributes) << New->getDeclName() << New->getType() << Old->getType(); Diag(Old->getLocation(), diag::note_overridden_virtual_function); return true; } bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New, const CXXMethodDecl *Old) { QualType NewTy = New->getType()->getAs<FunctionType>()->getReturnType(); QualType OldTy = Old->getType()->getAs<FunctionType>()->getReturnType(); if (Context.hasSameType(NewTy, OldTy) || NewTy->isDependentType() || OldTy->isDependentType()) return false; // Check if the return types are covariant QualType NewClassTy, OldClassTy; /// Both types must be pointers or references to classes. if (const PointerType *NewPT = NewTy->getAs<PointerType>()) { if (const PointerType *OldPT = OldTy->getAs<PointerType>()) { NewClassTy = NewPT->getPointeeType(); OldClassTy = OldPT->getPointeeType(); } } else if (const ReferenceType *NewRT = NewTy->getAs<ReferenceType>()) { if (const ReferenceType *OldRT = OldTy->getAs<ReferenceType>()) { if (NewRT->getTypeClass() == OldRT->getTypeClass()) { NewClassTy = NewRT->getPointeeType(); OldClassTy = OldRT->getPointeeType(); } } } // The return types aren't either both pointers or references to a class type. if (NewClassTy.isNull()) { Diag(New->getLocation(), diag::err_different_return_type_for_overriding_virtual_function) << New->getDeclName() << NewTy << OldTy << New->getReturnTypeSourceRange(); Diag(Old->getLocation(), diag::note_overridden_virtual_function) << Old->getReturnTypeSourceRange(); return true; } // C++ [class.virtual]p6: // If the return type of D::f differs from the return type of B::f, the // class type in the return type of D::f shall be complete at the point of // declaration of D::f or shall be the class type D. if (const RecordType *RT = NewClassTy->getAs<RecordType>()) { if (!RT->isBeingDefined() && RequireCompleteType(New->getLocation(), NewClassTy, diag::err_covariant_return_incomplete, New->getDeclName())) return true; } if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) { // Check if the new class derives from the old class. if (!IsDerivedFrom(New->getLocation(), NewClassTy, OldClassTy)) { Diag(New->getLocation(), diag::err_covariant_return_not_derived) << New->getDeclName() << NewTy << OldTy << New->getReturnTypeSourceRange(); Diag(Old->getLocation(), diag::note_overridden_virtual_function) << Old->getReturnTypeSourceRange(); return true; } // Check if we the conversion from derived to base is valid. if (CheckDerivedToBaseConversion( NewClassTy, OldClassTy, diag::err_covariant_return_inaccessible_base, diag::err_covariant_return_ambiguous_derived_to_base_conv, New->getLocation(), New->getReturnTypeSourceRange(), New->getDeclName(), nullptr)) { // FIXME: this note won't trigger for delayed access control // diagnostics, and it's impossible to get an undelayed error // here from access control during the original parse because // the ParsingDeclSpec/ParsingDeclarator are still in scope. Diag(Old->getLocation(), diag::note_overridden_virtual_function) << Old->getReturnTypeSourceRange(); return true; } } // The qualifiers of the return types must be the same. if (NewTy.getLocalCVRQualifiers() != OldTy.getLocalCVRQualifiers()) { Diag(New->getLocation(), diag::err_covariant_return_type_different_qualifications) << New->getDeclName() << NewTy << OldTy << New->getReturnTypeSourceRange(); Diag(Old->getLocation(), diag::note_overridden_virtual_function) << Old->getReturnTypeSourceRange(); return true; }; // The new class type must have the same or less qualifiers as the old type. if (NewClassTy.isMoreQualifiedThan(OldClassTy)) { Diag(New->getLocation(), diag::err_covariant_return_type_class_type_more_qualified) << New->getDeclName() << NewTy << OldTy << New->getReturnTypeSourceRange(); Diag(Old->getLocation(), diag::note_overridden_virtual_function) << Old->getReturnTypeSourceRange(); return true; }; return false; } /// \brief Mark the given method pure. /// /// \param Method the method to be marked pure. /// /// \param InitRange the source range that covers the "0" initializer. bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) { SourceLocation EndLoc = InitRange.getEnd(); if (EndLoc.isValid()) Method->setRangeEnd(EndLoc); if (Method->isVirtual() || Method->getParent()->isDependentContext()) { Method->setPure(); return false; } if (!Method->isInvalidDecl()) Diag(Method->getLocation(), diag::err_non_virtual_pure) << Method->getDeclName() << InitRange; return true; } void Sema::ActOnPureSpecifier(Decl *D, SourceLocation ZeroLoc) { if (D->getFriendObjectKind()) Diag(D->getLocation(), diag::err_pure_friend); else if (auto *M = dyn_cast<CXXMethodDecl>(D)) CheckPureMethod(M, ZeroLoc); else Diag(D->getLocation(), diag::err_illegal_initializer); } /// \brief Determine whether the given declaration is a static data member. static bool isStaticDataMember(const Decl *D) { if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(D)) return Var->isStaticDataMember(); return false; } /// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse /// an initializer for the out-of-line declaration 'Dcl'. The scope /// is a fresh scope pushed for just this purpose. /// /// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a /// static data member of class X, names should be looked up in the scope of /// class X. void Sema::ActOnCXXEnterDeclInitializer(Scope *S, Decl *D) { // If there is no declaration, there was an error parsing it. if (!D || D->isInvalidDecl()) return; // We will always have a nested name specifier here, but this declaration // might not be out of line if the specifier names the current namespace: // extern int n; // int ::n = 0; if (D->isOutOfLine()) EnterDeclaratorContext(S, D->getDeclContext()); // If we are parsing the initializer for a static data member, push a // new expression evaluation context that is associated with this static // data member. if (isStaticDataMember(D)) PushExpressionEvaluationContext(PotentiallyEvaluated, D); } /// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an /// initializer for the out-of-line declaration 'D'. void Sema::ActOnCXXExitDeclInitializer(Scope *S, Decl *D) { // If there is no declaration, there was an error parsing it. if (!D || D->isInvalidDecl()) return; if (isStaticDataMember(D)) PopExpressionEvaluationContext(); if (D->isOutOfLine()) ExitDeclaratorContext(S); } /// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a /// C++ if/switch/while/for statement. /// e.g: "if (int x = f()) {...}" DeclResult Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) { // C++ 6.4p2: // The declarator shall not specify a function or an array. // The type-specifier-seq shall not contain typedef and shall not declare a // new class or enumeration. assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef && "Parser allowed 'typedef' as storage class of condition decl."); Decl *Dcl = ActOnDeclarator(S, D); if (!Dcl) return true; if (isa<FunctionDecl>(Dcl)) { // The declarator shall not specify a function. Diag(Dcl->getLocation(), diag::err_invalid_use_of_function_type) << D.getSourceRange(); return true; } return Dcl; } void Sema::LoadExternalVTableUses() { if (!ExternalSource) return; SmallVector<ExternalVTableUse, 4> VTables; ExternalSource->ReadUsedVTables(VTables); SmallVector<VTableUse, 4> NewUses; for (unsigned I = 0, N = VTables.size(); I != N; ++I) { llvm::DenseMap<CXXRecordDecl *, bool>::iterator Pos = VTablesUsed.find(VTables[I].Record); // Even if a definition wasn't required before, it may be required now. if (Pos != VTablesUsed.end()) { if (!Pos->second && VTables[I].DefinitionRequired) Pos->second = true; continue; } VTablesUsed[VTables[I].Record] = VTables[I].DefinitionRequired; NewUses.push_back(VTableUse(VTables[I].Record, VTables[I].Location)); } VTableUses.insert(VTableUses.begin(), NewUses.begin(), NewUses.end()); } void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class, bool DefinitionRequired) { // Ignore any vtable uses in unevaluated operands or for classes that do // not have a vtable. if (!Class->isDynamicClass() || Class->isDependentContext() || CurContext->isDependentContext() || isUnevaluatedContext()) return; // Try to insert this class into the map. LoadExternalVTableUses(); Class = cast<CXXRecordDecl>(Class->getCanonicalDecl()); std::pair<llvm::DenseMap<CXXRecordDecl *, bool>::iterator, bool> Pos = VTablesUsed.insert(std::make_pair(Class, DefinitionRequired)); if (!Pos.second) { // If we already had an entry, check to see if we are promoting this vtable // to require a definition. If so, we need to reappend to the VTableUses // list, since we may have already processed the first entry. if (DefinitionRequired && !Pos.first->second) { Pos.first->second = true; } else { // Otherwise, we can early exit. return; } } else { // The Microsoft ABI requires that we perform the destructor body // checks (i.e. operator delete() lookup) when the vtable is marked used, as // the deleting destructor is emitted with the vtable, not with the // destructor definition as in the Itanium ABI. // If it has a definition, we do the check at that point instead. if (Context.getTargetInfo().getCXXABI().isMicrosoft() && Class->hasUserDeclaredDestructor() && !Class->getDestructor()->isDefined() && !Class->getDestructor()->isDeleted()) { CXXDestructorDecl *DD = Class->getDestructor(); ContextRAII SavedContext(*this, DD); CheckDestructor(DD); } } // Local classes need to have their virtual members marked // immediately. For all other classes, we mark their virtual members // at the end of the translation unit. if (Class->isLocalClass()) MarkVirtualMembersReferenced(Loc, Class); else VTableUses.push_back(std::make_pair(Class, Loc)); } bool Sema::DefineUsedVTables() { LoadExternalVTableUses(); if (VTableUses.empty()) return false; // Note: The VTableUses vector could grow as a result of marking // the members of a class as "used", so we check the size each // time through the loop and prefer indices (which are stable) to // iterators (which are not). bool DefinedAnything = false; for (unsigned I = 0; I != VTableUses.size(); ++I) { CXXRecordDecl *Class = VTableUses[I].first->getDefinition(); if (!Class) continue; SourceLocation Loc = VTableUses[I].second; bool DefineVTable = true; // If this class has a key function, but that key function is // defined in another translation unit, we don't need to emit the // vtable even though we're using it. const CXXMethodDecl *KeyFunction = Context.getCurrentKeyFunction(Class); if (KeyFunction && !KeyFunction->hasBody()) { // The key function is in another translation unit. DefineVTable = false; TemplateSpecializationKind TSK = KeyFunction->getTemplateSpecializationKind(); assert(TSK != TSK_ExplicitInstantiationDefinition && TSK != TSK_ImplicitInstantiation && "Instantiations don't have key functions"); (void)TSK; } else if (!KeyFunction) { // If we have a class with no key function that is the subject // of an explicit instantiation declaration, suppress the // vtable; it will live with the explicit instantiation // definition. bool IsExplicitInstantiationDeclaration = Class->getTemplateSpecializationKind() == TSK_ExplicitInstantiationDeclaration; for (auto R : Class->redecls()) { TemplateSpecializationKind TSK = cast<CXXRecordDecl>(R)->getTemplateSpecializationKind(); if (TSK == TSK_ExplicitInstantiationDeclaration) IsExplicitInstantiationDeclaration = true; else if (TSK == TSK_ExplicitInstantiationDefinition) { IsExplicitInstantiationDeclaration = false; break; } } if (IsExplicitInstantiationDeclaration) DefineVTable = false; } // The exception specifications for all virtual members may be needed even // if we are not providing an authoritative form of the vtable in this TU. // We may choose to emit it available_externally anyway. if (!DefineVTable) { MarkVirtualMemberExceptionSpecsNeeded(Loc, Class); continue; } // Mark all of the virtual members of this class as referenced, so // that we can build a vtable. Then, tell the AST consumer that a // vtable for this class is required. DefinedAnything = true; MarkVirtualMembersReferenced(Loc, Class); CXXRecordDecl *Canonical = cast<CXXRecordDecl>(Class->getCanonicalDecl()); if (VTablesUsed[Canonical]) Consumer.HandleVTable(Class); // Optionally warn if we're emitting a weak vtable. if (Class->isExternallyVisible() && Class->getTemplateSpecializationKind() != TSK_ImplicitInstantiation) { const FunctionDecl *KeyFunctionDef = nullptr; if (!KeyFunction || (KeyFunction->hasBody(KeyFunctionDef) && KeyFunctionDef->isInlined())) Diag(Class->getLocation(), Class->getTemplateSpecializationKind() == TSK_ExplicitInstantiationDefinition ? diag::warn_weak_template_vtable : diag::warn_weak_vtable) << Class; } } VTableUses.clear(); return DefinedAnything; } void Sema::MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc, const CXXRecordDecl *RD) { for (const auto *I : RD->methods()) if (I->isVirtual() && !I->isPure()) ResolveExceptionSpec(Loc, I->getType()->castAs<FunctionProtoType>()); } void Sema::MarkVirtualMembersReferenced(SourceLocation Loc, const CXXRecordDecl *RD) { // Mark all functions which will appear in RD's vtable as used. CXXFinalOverriderMap FinalOverriders; RD->getFinalOverriders(FinalOverriders); for (CXXFinalOverriderMap::const_iterator I = FinalOverriders.begin(), E = FinalOverriders.end(); I != E; ++I) { for (OverridingMethods::const_iterator OI = I->second.begin(), OE = I->second.end(); OI != OE; ++OI) { assert(OI->second.size() > 0 && "no final overrider"); CXXMethodDecl *Overrider = OI->second.front().Method; // C++ [basic.def.odr]p2: // [...] A virtual member function is used if it is not pure. [...] if (!Overrider->isPure()) MarkFunctionReferenced(Loc, Overrider); } } // Only classes that have virtual bases need a VTT. if (RD->getNumVBases() == 0) return; for (const auto &I : RD->bases()) { const CXXRecordDecl *Base = cast<CXXRecordDecl>(I.getType()->getAs<RecordType>()->getDecl()); if (Base->getNumVBases() == 0) continue; MarkVirtualMembersReferenced(Loc, Base); } } /// SetIvarInitializers - This routine builds initialization ASTs for the /// Objective-C implementation whose ivars need be initialized. void Sema::SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation) { if (!getLangOpts().CPlusPlus) return; if (ObjCInterfaceDecl *OID = ObjCImplementation->getClassInterface()) { SmallVector<ObjCIvarDecl*, 8> ivars; CollectIvarsToConstructOrDestruct(OID, ivars); if (ivars.empty()) return; SmallVector<CXXCtorInitializer*, 32> AllToInit; for (unsigned i = 0; i < ivars.size(); i++) { FieldDecl *Field = ivars[i]; if (Field->isInvalidDecl()) continue; CXXCtorInitializer *Member; InitializedEntity InitEntity = InitializedEntity::InitializeMember(Field); InitializationKind InitKind = InitializationKind::CreateDefault(ObjCImplementation->getLocation()); InitializationSequence InitSeq(*this, InitEntity, InitKind, None); ExprResult MemberInit = InitSeq.Perform(*this, InitEntity, InitKind, None); MemberInit = MaybeCreateExprWithCleanups(MemberInit); // Note, MemberInit could actually come back empty if no initialization // is required (e.g., because it would call a trivial default constructor) if (!MemberInit.get() || MemberInit.isInvalid()) continue; Member = new (Context) CXXCtorInitializer(Context, Field, SourceLocation(), SourceLocation(), MemberInit.getAs<Expr>(), SourceLocation()); AllToInit.push_back(Member); // Be sure that the destructor is accessible and is marked as referenced. if (const RecordType *RecordTy = Context.getBaseElementType(Field->getType()) ->getAs<RecordType>()) { CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl()); if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) { MarkFunctionReferenced(Field->getLocation(), Destructor); CheckDestructorAccess(Field->getLocation(), Destructor, PDiag(diag::err_access_dtor_ivar) << Context.getBaseElementType(Field->getType())); } } } ObjCImplementation->setIvarInitializers(Context, AllToInit.data(), AllToInit.size()); } } static void DelegatingCycleHelper(CXXConstructorDecl* Ctor, llvm::SmallSet<CXXConstructorDecl*, 4> &Valid, llvm::SmallSet<CXXConstructorDecl*, 4> &Invalid, llvm::SmallSet<CXXConstructorDecl*, 4> &Current, Sema &S) { if (Ctor->isInvalidDecl()) return; CXXConstructorDecl *Target = Ctor->getTargetConstructor(); // Target may not be determinable yet, for instance if this is a dependent // call in an uninstantiated template. if (Target) { const FunctionDecl *FNTarget = nullptr; (void)Target->hasBody(FNTarget); Target = const_cast<CXXConstructorDecl*>( cast_or_null<CXXConstructorDecl>(FNTarget)); } CXXConstructorDecl *Canonical = Ctor->getCanonicalDecl(), // Avoid dereferencing a null pointer here. *TCanonical = Target? Target->getCanonicalDecl() : nullptr; if (!Current.insert(Canonical).second) return; // We know that beyond here, we aren't chaining into a cycle. if (!Target || !Target->isDelegatingConstructor() || Target->isInvalidDecl() || Valid.count(TCanonical)) { Valid.insert(Current.begin(), Current.end()); Current.clear(); // We've hit a cycle. } else if (TCanonical == Canonical || Invalid.count(TCanonical) || Current.count(TCanonical)) { // If we haven't diagnosed this cycle yet, do so now. if (!Invalid.count(TCanonical)) { S.Diag((*Ctor->init_begin())->getSourceLocation(), diag::warn_delegating_ctor_cycle) << Ctor; // Don't add a note for a function delegating directly to itself. if (TCanonical != Canonical) S.Diag(Target->getLocation(), diag::note_it_delegates_to); CXXConstructorDecl *C = Target; while (C->getCanonicalDecl() != Canonical) { const FunctionDecl *FNTarget = nullptr; (void)C->getTargetConstructor()->hasBody(FNTarget); assert(FNTarget && "Ctor cycle through bodiless function"); C = const_cast<CXXConstructorDecl*>( cast<CXXConstructorDecl>(FNTarget)); S.Diag(C->getLocation(), diag::note_which_delegates_to); } } Invalid.insert(Current.begin(), Current.end()); Current.clear(); } else { DelegatingCycleHelper(Target, Valid, Invalid, Current, S); } } void Sema::CheckDelegatingCtorCycles() { llvm::SmallSet<CXXConstructorDecl*, 4> Valid, Invalid, Current; for (DelegatingCtorDeclsType::iterator I = DelegatingCtorDecls.begin(ExternalSource), E = DelegatingCtorDecls.end(); I != E; ++I) DelegatingCycleHelper(*I, Valid, Invalid, Current, *this); for (llvm::SmallSet<CXXConstructorDecl *, 4>::iterator CI = Invalid.begin(), CE = Invalid.end(); CI != CE; ++CI) (*CI)->setInvalidDecl(); } namespace { /// \brief AST visitor that finds references to the 'this' expression. class FindCXXThisExpr : public RecursiveASTVisitor<FindCXXThisExpr> { Sema &S; public: explicit FindCXXThisExpr(Sema &S) : S(S) { } bool VisitCXXThisExpr(CXXThisExpr *E) { S.Diag(E->getLocation(), diag::err_this_static_member_func) << E->isImplicit(); return false; } }; } bool Sema::checkThisInStaticMemberFunctionType(CXXMethodDecl *Method) { TypeSourceInfo *TSInfo = Method->getTypeSourceInfo(); if (!TSInfo) return false; TypeLoc TL = TSInfo->getTypeLoc(); FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>(); if (!ProtoTL) return false; // C++11 [expr.prim.general]p3: // [The expression this] shall not appear before the optional // cv-qualifier-seq and it shall not appear within the declaration of a // static member function (although its type and value category are defined // within a static member function as they are within a non-static member // function). [ Note: this is because declaration matching does not occur // until the complete declarator is known. - end note ] const FunctionProtoType *Proto = ProtoTL.getTypePtr(); FindCXXThisExpr Finder(*this); // If the return type came after the cv-qualifier-seq, check it now. if (Proto->hasTrailingReturn() && !Finder.TraverseTypeLoc(ProtoTL.getReturnLoc())) return true; // Check the exception specification. if (checkThisInStaticMemberFunctionExceptionSpec(Method)) return true; return checkThisInStaticMemberFunctionAttributes(Method); } bool Sema::checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method) { TypeSourceInfo *TSInfo = Method->getTypeSourceInfo(); if (!TSInfo) return false; TypeLoc TL = TSInfo->getTypeLoc(); FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>(); if (!ProtoTL) return false; const FunctionProtoType *Proto = ProtoTL.getTypePtr(); FindCXXThisExpr Finder(*this); switch (Proto->getExceptionSpecType()) { case EST_Unparsed: case EST_Uninstantiated: case EST_Unevaluated: case EST_BasicNoexcept: case EST_DynamicNone: case EST_MSAny: case EST_None: break; case EST_ComputedNoexcept: if (!Finder.TraverseStmt(Proto->getNoexceptExpr())) return true; case EST_Dynamic: for (const auto &E : Proto->exceptions()) { if (!Finder.TraverseType(E)) return true; } break; } return false; } bool Sema::checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method) { FindCXXThisExpr Finder(*this); // Check attributes. for (const auto *A : Method->attrs()) { // FIXME: This should be emitted by tblgen. Expr *Arg = nullptr; ArrayRef<Expr *> Args; if (const auto *G = dyn_cast<GuardedByAttr>(A)) Arg = G->getArg(); else if (const auto *G = dyn_cast<PtGuardedByAttr>(A)) Arg = G->getArg(); else if (const auto *AA = dyn_cast<AcquiredAfterAttr>(A)) Args = llvm::makeArrayRef(AA->args_begin(), AA->args_size()); else if (const auto *AB = dyn_cast<AcquiredBeforeAttr>(A)) Args = llvm::makeArrayRef(AB->args_begin(), AB->args_size()); else if (const auto *ETLF = dyn_cast<ExclusiveTrylockFunctionAttr>(A)) { Arg = ETLF->getSuccessValue(); Args = llvm::makeArrayRef(ETLF->args_begin(), ETLF->args_size()); } else if (const auto *STLF = dyn_cast<SharedTrylockFunctionAttr>(A)) { Arg = STLF->getSuccessValue(); Args = llvm::makeArrayRef(STLF->args_begin(), STLF->args_size()); } else if (const auto *LR = dyn_cast<LockReturnedAttr>(A)) Arg = LR->getArg(); else if (const auto *LE = dyn_cast<LocksExcludedAttr>(A)) Args = llvm::makeArrayRef(LE->args_begin(), LE->args_size()); else if (const auto *RC = dyn_cast<RequiresCapabilityAttr>(A)) Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size()); else if (const auto *AC = dyn_cast<AcquireCapabilityAttr>(A)) Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size()); else if (const auto *AC = dyn_cast<TryAcquireCapabilityAttr>(A)) Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size()); else if (const auto *RC = dyn_cast<ReleaseCapabilityAttr>(A)) Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size()); if (Arg && !Finder.TraverseStmt(Arg)) return true; for (unsigned I = 0, N = Args.size(); I != N; ++I) { if (!Finder.TraverseStmt(Args[I])) return true; } } return false; } void Sema::checkExceptionSpecification( bool IsTopLevel, ExceptionSpecificationType EST, ArrayRef<ParsedType> DynamicExceptions, ArrayRef<SourceRange> DynamicExceptionRanges, Expr *NoexceptExpr, SmallVectorImpl<QualType> &Exceptions, FunctionProtoType::ExceptionSpecInfo &ESI) { Exceptions.clear(); ESI.Type = EST; if (EST == EST_Dynamic) { Exceptions.reserve(DynamicExceptions.size()); for (unsigned ei = 0, ee = DynamicExceptions.size(); ei != ee; ++ei) { // FIXME: Preserve type source info. QualType ET = GetTypeFromParser(DynamicExceptions[ei]); if (IsTopLevel) { SmallVector<UnexpandedParameterPack, 2> Unexpanded; collectUnexpandedParameterPacks(ET, Unexpanded); if (!Unexpanded.empty()) { DiagnoseUnexpandedParameterPacks( DynamicExceptionRanges[ei].getBegin(), UPPC_ExceptionType, Unexpanded); continue; } } // Check that the type is valid for an exception spec, and // drop it if not. if (!CheckSpecifiedExceptionType(ET, DynamicExceptionRanges[ei])) Exceptions.push_back(ET); } ESI.Exceptions = Exceptions; return; } if (EST == EST_ComputedNoexcept) { // If an error occurred, there's no expression here. if (NoexceptExpr) { assert((NoexceptExpr->isTypeDependent() || NoexceptExpr->getType()->getCanonicalTypeUnqualified() == Context.BoolTy) && "Parser should have made sure that the expression is boolean"); if (IsTopLevel && NoexceptExpr && DiagnoseUnexpandedParameterPack(NoexceptExpr)) { ESI.Type = EST_BasicNoexcept; return; } if (!NoexceptExpr->isValueDependent()) NoexceptExpr = VerifyIntegerConstantExpression(NoexceptExpr, nullptr, diag::err_noexcept_needs_constant_expression, /*AllowFold*/ false).get(); ESI.NoexceptExpr = NoexceptExpr; } return; } } void Sema::actOnDelayedExceptionSpecification(Decl *MethodD, ExceptionSpecificationType EST, SourceRange SpecificationRange, ArrayRef<ParsedType> DynamicExceptions, ArrayRef<SourceRange> DynamicExceptionRanges, Expr *NoexceptExpr) { if (!MethodD) return; // Dig out the method we're referring to. if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(MethodD)) MethodD = FunTmpl->getTemplatedDecl(); CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(MethodD); if (!Method) return; // Check the exception specification. llvm::SmallVector<QualType, 4> Exceptions; FunctionProtoType::ExceptionSpecInfo ESI; checkExceptionSpecification(/*IsTopLevel*/true, EST, DynamicExceptions, DynamicExceptionRanges, NoexceptExpr, Exceptions, ESI); // Update the exception specification on the function type. Context.adjustExceptionSpec(Method, ESI, /*AsWritten*/true); if (Method->isStatic()) checkThisInStaticMemberFunctionExceptionSpec(Method); if (Method->isVirtual()) { // Check overrides, which we previously had to delay. for (CXXMethodDecl::method_iterator O = Method->begin_overridden_methods(), OEnd = Method->end_overridden_methods(); O != OEnd; ++O) CheckOverridingFunctionExceptionSpec(Method, *O); } } /// HandleMSProperty - Analyze a __delcspec(property) field of a C++ class. /// MSPropertyDecl *Sema::HandleMSProperty(Scope *S, RecordDecl *Record, SourceLocation DeclStart, Declarator &D, Expr *BitWidth, InClassInitStyle InitStyle, AccessSpecifier AS, AttributeList *MSPropertyAttr) { IdentifierInfo *II = D.getIdentifier(); if (!II) { Diag(DeclStart, diag::err_anonymous_property); return nullptr; } SourceLocation Loc = D.getIdentifierLoc(); TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); QualType T = TInfo->getType(); if (getLangOpts().CPlusPlus) { CheckExtraCXXDefaultArguments(D); if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo, UPPC_DataMemberType)) { D.setInvalidType(); T = Context.IntTy; TInfo = Context.getTrivialTypeSourceInfo(T, Loc); } } DiagnoseFunctionSpecifiers(D.getDeclSpec()); if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec()) Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(), diag::err_invalid_thread) << DeclSpec::getSpecifierName(TSCS); // Check to see if this name was declared as a member previously NamedDecl *PrevDecl = nullptr; LookupResult Previous(*this, II, Loc, LookupMemberName, ForRedeclaration); LookupName(Previous, S); switch (Previous.getResultKind()) { case LookupResult::Found: case LookupResult::FoundUnresolvedValue: PrevDecl = Previous.getAsSingle<NamedDecl>(); break; case LookupResult::FoundOverloaded: PrevDecl = Previous.getRepresentativeDecl(); break; case LookupResult::NotFound: case LookupResult::NotFoundInCurrentInstantiation: case LookupResult::Ambiguous: break; } if (PrevDecl && PrevDecl->isTemplateParameter()) { // Maybe we will complain about the shadowed template parameter. DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); // Just pretend that we didn't see the previous declaration. PrevDecl = nullptr; } if (PrevDecl && !isDeclInScope(PrevDecl, Record, S)) PrevDecl = nullptr; SourceLocation TSSL = D.getLocStart(); const AttributeList::PropertyData &Data = MSPropertyAttr->getPropertyData(); MSPropertyDecl *NewPD = MSPropertyDecl::Create( Context, Record, Loc, II, T, TInfo, TSSL, Data.GetterId, Data.SetterId); ProcessDeclAttributes(TUScope, NewPD, D); NewPD->setAccess(AS); if (NewPD->isInvalidDecl()) Record->setInvalidDecl(); if (D.getDeclSpec().isModulePrivateSpecified()) NewPD->setModulePrivate(); if (NewPD->isInvalidDecl() && PrevDecl) { // Don't introduce NewFD into scope; there's already something // with the same name in the same scope. } else if (II) { PushOnScopeChains(NewPD, S); } else Record->addDecl(NewPD); return NewPD; }