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Android 10
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10.0.0_r6
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external
clang
lib
Sema
SemaDeclCXX.cpp
//===------ 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
#include
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
{ 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
(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
(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
(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
(); 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
(); 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
(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
(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
(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
(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 the right previous declaration. 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
(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
(New->getDeclContext())) { if (Record->getDescribedClassTemplate()) WhichKind = 0; else if (isa
(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
(New) && New->getMinRequiredArguments() < Old->getMinRequiredArguments()) { CXXSpecialMember NewSM = getSpecialMember(cast
(New)), OldSM = getSpecialMember(cast
(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
()) { NewType = R->getPointeeType(); OldType = OldType->getAs
()->getPointeeType(); } else if (const PointerType *P = NewType->getAs
()) { NewType = P->getPointeeType(); OldType = OldType->getAs
()->getPointeeType(); } else if (const MemberPointerType *M = NewType->getAs
()) { NewType = M->getPointeeType(); OldType = OldType->getAs
()->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
(), Old->getLocation(), NewType->getAs
(), 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
(); 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
(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
(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
(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
(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
(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
(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
(Dcl); return false; } continue; } case Decl::Enum: case Decl::CXXRecord: // C++1y allows types to be defined, not just declared. if (cast
(DclIt)->isThisDeclarationADefinition()) SemaRef.Diag(DS->getLocStart(), SemaRef.getLangOpts().CPlusPlus14 ? diag::warn_cxx11_compat_constexpr_type_definition : diag::ext_constexpr_type_definition) << isa
(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
(DclIt); if (VD->isThisDeclarationADefinition()) { if (VD->isStaticLocal()) { SemaRef.Diag(VD->getLocation(), diag::err_constexpr_local_var_static) << isa
(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
(Dcl))) return false; if (!VD->getType()->isDependentType() && !VD->hasInit() && !VD->isCXXForRangeDecl()) { SemaRef.Diag(VD->getLocation(), diag::err_constexpr_local_var_no_init) << isa
(Dcl); return false; } } SemaRef.Diag(VD->getLocation(), SemaRef.getLangOpts().CPlusPlus14 ? diag::warn_cxx11_compat_constexpr_local_var : diag::ext_constexpr_local_var) << isa
(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
(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
&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
()->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
&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
(S), Cxx1yLoc)) return false; return true; case Stmt::ReturnStmtClass: // - and exactly one return statement; if (isa
(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
(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
(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
(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
(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
(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
(Dcl); return false; } SmallVector
ReturnStmts; // - its function-body shall be [...] a compound-statement that contains only // [... list of cases ...] CompoundStmt *CompBody = cast
(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
(Dcl); if (const CXXConstructorDecl *Constructor = dyn_cast
(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
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
Diags; if (!Expr::isPotentialConstantExpr(Dcl, Diags)) { Diag(Dcl->getLocation(), diag::ext_constexpr_function_never_constant_expr) << isa
(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
(DC); } else CurDecl = dyn_cast_or_null
(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
(DC); } else CurDecl = dyn_cast_or_null
(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
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
( 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
()->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
(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
()) { 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
(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
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
()) { 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, MutableArrayRef
Bases) { if (Bases.empty()) 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
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 < Bases.size(); ++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 (Bases.size() > 1) NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType); if (const RecordType *Record = NewBaseType->getAs
()) { const CXXRecordDecl *RD = cast
(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
()) Class->addAttr(WeakAttr::CreateImplicit(Context)); } } } // Attach the remaining base class specifiers to the derived class. Class->setBases(Bases.data(), 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, MutableArrayRef
Bases) { if (!ClassDecl || Bases.empty()) return; AdjustDeclIfTemplate(ClassDecl); AttachBaseSpecifiers(cast
(ClassDecl), Bases); } /// \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
(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. /// /// If either InaccessibleBaseID or AmbigiousBaseConvID are 0, then the /// diagnostic for the respective type of error will be suppressed, but the /// check for ill-formed code will still be performed. bool Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base, unsigned InaccessibleBaseID, unsigned AmbigiousBaseConvID, SourceLocation Loc, SourceRange Range, DeclarationName Name, CXXCastPath *BasePath, bool IgnoreAccess) { // 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 (!IgnoreAccess) { // 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, diag::err_upcast_to_inaccessible_base, diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(), BasePath, IgnoreAccess); } /// @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
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
() && !D->hasAttr
()) return; CXXMethodDecl *MD = dyn_cast
(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
OverloadedMethods; FindHiddenVirtualMethods(MD, OverloadedMethods); if (!OverloadedMethods.empty()) { if (OverrideAttr *OA = D->getAttr
()) { Diag(OA->getLocation(), diag::override_keyword_hides_virtual_member_function) << "override" << (OverloadedMethods.size() > 1); } else if (FinalAttr *FA = D->getAttr
()) { 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
()) { Diag(OA->getLocation(), diag::override_keyword_only_allowed_on_virtual_member_functions) << "override" << FixItHint::CreateRemoval(OA->getLocation()); D->dropAttr
(); } if (FinalAttr *FA = D->getAttr
()) { Diag(FA->getLocation(), diag::override_keyword_only_allowed_on_virtual_member_functions) << (FA->isSpelledAsSealed() ? "sealed" : "final") << FixItHint::CreateRemoval(FA->getLocation()); D->dropAttr
(); } 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
() && !HasOverriddenMethods) Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding) << MD->getDeclName(); } void Sema::DiagnoseAbsenceOfOverrideControl(NamedDecl *D) { if (D->isInvalidDecl() || D->hasAttr
()) return; CXXMethodDecl *MD = dyn_cast
(D); if (!MD || MD->isImplicit() || MD->hasAttr
() || isa
(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
(); 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
(BW); assert(isa
(CurContext)); assert(!DS.isFriendSpecified()); bool isFunc = D.isDeclarationOfFunction(); if (cast
(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
(CurContext), Loc, D, BitWidth, InitStyle, AS, MSPropertyAttr); if (!Member) return nullptr; isInstField = false; } else { Member = HandleField(S, cast
(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
(Member) || isa
(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
(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
(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
(Member)) FunTmpl->getTemplatedDecl()->setAccess(AS); else if (VarTemplateDecl *VarTmpl = dyn_cast
(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
(Member)) MD->setRangeEnd(VS.getLastLocation()); } CheckOverrideControl(Member); assert((Name || isInstField) && "No identifier for non-field ?"); if (isInstField) { FieldDecl *FD = cast
(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
() && !FD->getParent()->isDependentContext() && !InitializationHasSideEffects(*FD)) UnusedPrivateFields.insert(FD); } } return Member; } namespace { class UninitializedFieldVisitor : public EvaluatedExprVisitor
{ Sema &S; // List of Decls to generate a warning on. Also remove Decls that become // initialized. llvm::SmallPtrSetImpl
&Decls; // List of base classes of the record. Classes are removed after their // initializers. llvm::SmallPtrSetImpl
&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
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
InitFieldIndex; public: typedef EvaluatedExprVisitor
Inherited; UninitializedFieldVisitor(Sema &S, llvm::SmallPtrSetImpl
&Decls, llvm::SmallPtrSetImpl
&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
Fields; bool ReferenceField = false; while (ME) { FieldDecl *FD = dyn_cast
(ME->getMemberDecl()); if (!FD) return false; Fields.push_back(FD); if (FD->getType()->isReferenceType()) ReferenceField = true; ME = dyn_cast
(ME->getBase()->IgnoreParenImpCasts()); } // Binding a reference to an unintialized field is not an // uninitialized use. if (CheckReferenceOnly && !ReferenceField) return true; llvm::SmallVector
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
(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
(Base->IgnoreParenImpCasts())) { if (isa
(SubME->getMemberDecl())) return; if (FieldDecl *FD = dyn_cast
(SubME->getMemberDecl())) if (!FD->isAnonymousStructOrUnion()) FieldME = SubME; if (!FieldME->getType().isPODType(S.Context)) AllPODFields = false; Base = SubME->getBase(); } if (!isa
(Base->IgnoreParenImpCasts())) return; if (AddressOf && AllPODFields) return; ValueDecl* FoundVD = FieldME->getMemberDecl(); if (ImplicitCastExpr *BaseCast = dyn_cast
(Base)) { while (isa
(BaseCast->getSubExpr())) { BaseCast = cast
(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
(E)) { HandleMemberExpr(ME, false /*CheckReferenceOnly*/, AddressOf /*AddressOf*/); return; } if (ConditionalOperator *CO = dyn_cast
(E)) { Visit(CO->getCond()); HandleValue(CO->getTrueExpr(), AddressOf); HandleValue(CO->getFalseExpr(), AddressOf); return; } if (BinaryConditionalOperator *BCO = dyn_cast
(E)) { Visit(BCO->getCond()); HandleValue(BCO->getFalseExpr(), AddressOf); return; } if (OpaqueValueExpr *OVE = dyn_cast
(E)) { HandleValue(OVE->getSourceExpr(), AddressOf); return; } if (BinaryOperator *BO = dyn_cast
(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
(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
(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
(ArgExpr)) if (ILE->getNumInits() == 1) ArgExpr = ILE->getInit(0); if (ImplicitCastExpr *ICE = dyn_cast
(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
(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
(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
(E->getLHS())) if (FieldDecl *FD = dyn_cast
(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
(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
UninitializedFields; // At the beginning, all fields are uninitialized. for (auto *I : RD->decls()) { if (auto *FD = dyn_cast
(I)) { UninitializedFields.insert(FD); } else if (auto *IFD = dyn_cast
(I)) { UninitializedFields.insert(IFD->getAnonField()); } } llvm::SmallPtrSet
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
(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
(D); assert((isa
(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
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
(ND)) return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl); return isa
(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
(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
(Result.front())) || (Member = dyn_cast
(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
(); 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
(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
(ClassDecl), CTK_ErrorRecovery, ClassDecl))) { if (FieldDecl *Member = Corr.getCorrectionDeclAs
()) { // 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
()) { 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
(); TL.getNamedTypeLoc().castAs
().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
(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
(Init->IgnoreParens())) { // We only warn when referring to a non-reference parameter declaration. const ParmVarDecl *Parameter = dyn_cast
(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
(Member); IndirectFieldDecl *IndirectMember = dyn_cast
(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
(Init)) { Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs()); } else if (InitListExpr *InitList = dyn_cast
(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
(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
(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
(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
(), 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
(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
(), InitRange.getEnd(), EllipsisLoc); } // Create a static_cast\
(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: 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
(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
(), SourceLocation(), SourceLocation()); return false; } static bool RefersToRValueRef(Expr *MemRef) { ValueDecl *Referenced = cast
(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
(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
(Indirect) : cast
(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
(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
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
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
(); 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
(), Loc); } else CXXMemberInit = CXXCtorInitializer::Create(SemaRef.Context, Field, Loc, Loc, MemberInit.getAs
(), 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
AllBaseFields; SmallVector
AllToInit; llvm::DenseMap
ActiveUnionMember; BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits) : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) { bool Generated = Ctor->isImplicit() || Ctor->isDefaulted(); if (Ctor->getInheritedConstructor()) IIK = IIK_Inherit; else if (Generated && Ctor->isCopyConstructor()) IIK = IIK_Copy; else if (Generated && Ctor->isMoveConstructor()) IIK = IIK_Move; 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
(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
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
()] = Member; else { Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member; if (IndirectFieldDecl *F = Member->getIndirectMember()) { for (auto *C : F->chain()) { FieldDecl *FD = dyn_cast
(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
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
())) { // [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
())) { 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
(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
(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
&IdealInits) { if (const RecordType *RT = Field->getType()->getAs
()) { 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
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
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
UnionEntry; typedef llvm::DenseMap
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
(Parent->getDeclContext()); } return false; } } /// ActOnMemInitializers - Handle the member initializers for a constructor. void Sema::ActOnMemInitializers(Decl *ConstructorDecl, SourceLocation ColonLoc, ArrayRef
MemInits, bool AnyErrors) { if (!ConstructorDecl) return; AdjustDeclIfTemplate(ConstructorDecl); CXXConstructorDecl *Constructor = dyn_cast
(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
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
(); if (!RT) continue; CXXRecordDecl *FieldClassDecl = cast
(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
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
(); // Remember direct virtual bases. if (Base.isVirtual()) DirectVirtualBases.insert(RT); CXXRecordDecl *BaseClassDecl = cast
(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
(); // Ignore direct virtual bases. if (DirectVirtualBases.count(RT)) continue; CXXRecordDecl *BaseClassDecl = cast
(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
(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
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
(), 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
(D)) { CheckAbstractClassUsage(Info, cast
(D)); } else if (isa
(D)) { FunctionDecl *FD = cast
(D)->getTemplatedDecl(); CheckAbstractClassUsage(Info, cast
(FD)); // Fields and static variables. } else if (isa
(D)) { FieldDecl *FD = cast
(D); if (TypeSourceInfo *TSI = FD->getTypeSourceInfo()) Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType); } else if (isa
(D)) { VarDecl *VD = cast
(D); if (TypeSourceInfo *TSI = VD->getTypeSourceInfo()) Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType); // Nested classes and class templates. } else if (isa
(D)) { CheckAbstractClassUsage(Info, cast
(D)); } else if (isa
(D)) { CheckAbstractClassUsage(Info, cast
(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
(Member); if (!MD) continue; if (Member->getAttr
()) { 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
(Class)) { if (Attr *TemplateAttr = getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) { auto *A = cast
(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
(Member) && !isa
(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; TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind(); // Ignore explicit dllexport on explicit class template instantiation declarations. if (ClassExported && !ClassAttr->isInherited() && TSK == TSK_ExplicitInstantiationDeclaration) { Class->dropAttr
(); 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
(Member); CXXMethodDecl *MD = dyn_cast
(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 // and move constructor, so don't attempt to import/export them if // we have a definition. auto *Ctor = dyn_cast
(MD); if ((MD->isMoveAssignmentOperator() || (Ctor && Ctor->isMoveConstructor())) && !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015)) continue; // MSVC2015 doesn't export trivial defaulted x-tor but copy assign // operator is exported anyway. if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) && (Ctor || isa
(MD)) && MD->isTrivial()) continue; } } if (!cast
(Member)->isExternallyVisible()) continue; if (!getDLLAttr(Member)) { auto *NewAttr = cast
(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
(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; } } static void DefineImplicitSpecialMember(Sema &S, CXXMethodDecl *MD, SourceLocation DefaultLoc) { switch (S.getSpecialMember(MD)) { case Sema::CXXDefaultConstructor: S.DefineImplicitDefaultConstructor(DefaultLoc, cast
(MD)); break; case Sema::CXXCopyConstructor: S.DefineImplicitCopyConstructor(DefaultLoc, cast
(MD)); break; case Sema::CXXCopyAssignment: S.DefineImplicitCopyAssignment(DefaultLoc, MD); break; case Sema::CXXDestructor: S.DefineImplicitDestructor(DefaultLoc, cast
(MD)); break; case Sema::CXXMoveConstructor: S.DefineImplicitMoveConstructor(DefaultLoc, cast