diff options
Diffstat (limited to 'lib/Sema')
-rw-r--r-- | lib/Sema/SemaDecl.cpp | 14 | ||||
-rw-r--r-- | lib/Sema/SemaDeclCXX.cpp | 408 | ||||
-rw-r--r-- | lib/Sema/SemaTemplateInstantiateDecl.cpp | 22 | ||||
-rw-r--r-- | lib/Sema/SemaType.cpp | 112 |
4 files changed, 541 insertions, 15 deletions
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp index 942c1bc5c2..f4b6ce92e5 100644 --- a/lib/Sema/SemaDecl.cpp +++ b/lib/Sema/SemaDecl.cpp @@ -4770,15 +4770,11 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC, // are implicitly inline. NewFD->setImplicitlyInline(); - // FIXME: If this is a redeclaration, check the original declaration was - // marked constepr. - // C++0x [dcl.constexpr]p3: functions declared constexpr are required to // be either constructors or to return a literal type. Therefore, // destructors cannot be declared constexpr. if (isa<CXXDestructorDecl>(NewFD)) - Diag(D.getDeclSpec().getConstexprSpecLoc(), - diag::err_constexpr_dtor); + Diag(D.getDeclSpec().getConstexprSpecLoc(), diag::err_constexpr_dtor); } // If __module_private__ was specified, mark the function accordingly. @@ -5050,6 +5046,10 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC, Previous.getResultKind() != LookupResult::FoundOverloaded) && "previous declaration set still overloaded"); + if (NewFD->isConstexpr() && !NewFD->isInvalidDecl() && + !CheckConstexprFunctionDecl(NewFD, CCK_Declaration)) + NewFD->setInvalidDecl(); + NamedDecl *PrincipalDecl = (FunctionTemplate ? cast<NamedDecl>(FunctionTemplate) : NewFD); @@ -6963,6 +6963,10 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body, ActivePolicy = &WP; } + if (FD && FD->isConstexpr() && !FD->isInvalidDecl() && + !CheckConstexprFunctionBody(FD, Body)) + FD->setInvalidDecl(); + assert(ExprTemporaries.empty() && "Leftover temporaries in function"); assert(!ExprNeedsCleanups && "Unaccounted cleanups in function"); } diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp index ae31e61c43..73fd18889e 100644 --- a/lib/Sema/SemaDeclCXX.cpp +++ b/lib/Sema/SemaDeclCXX.cpp @@ -502,6 +502,20 @@ bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old) { } } + // C++0x [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. [Note: An explicit specialization can + // differ from the template declaration with respect to the constexpr + // specifier. -- end note] + // + // FIXME: Don't reject changes in constexpr in explicit specializations. + 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; + } + if (CheckEquivalentExceptionSpec(Old, New)) Invalid = true; @@ -602,6 +616,359 @@ void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) { } } +// CheckConstexprParameterTypes - Check whether a function's parameter types +// are all literal types. If so, return true. If not, produce a suitable +// diagnostic depending on @p CCK and return false. +static bool CheckConstexprParameterTypes(Sema &SemaRef, const FunctionDecl *FD, + Sema::CheckConstexprKind CCK) { + unsigned ArgIndex = 0; + const FunctionProtoType *FT = FD->getType()->getAs<FunctionProtoType>(); + for (FunctionProtoType::arg_type_iterator i = FT->arg_type_begin(), + e = FT->arg_type_end(); i != e; ++i, ++ArgIndex) { + const ParmVarDecl *PD = FD->getParamDecl(ArgIndex); + SourceLocation ParamLoc = PD->getLocation(); + if (!(*i)->isDependentType() && + SemaRef.RequireLiteralType(ParamLoc, *i, CCK == Sema::CCK_Declaration ? + SemaRef.PDiag(diag::err_constexpr_non_literal_param) + << ArgIndex+1 << PD->getSourceRange() + << isa<CXXConstructorDecl>(FD) : + SemaRef.PDiag(), + /*AllowIncompleteType*/ true)) { + if (CCK == Sema::CCK_NoteNonConstexprInstantiation) + SemaRef.Diag(ParamLoc, diag::note_constexpr_tmpl_non_literal_param) + << ArgIndex+1 << PD->getSourceRange() + << isa<CXXConstructorDecl>(FD) << *i; + return false; + } + } + return true; +} + +// CheckConstexprFunctionDecl - Check whether a function declaration satisfies +// the requirements of a constexpr function declaration or a constexpr +// constructor declaration. Return true if it does, false if not. +// +// This implements C++0x [dcl.constexpr]p3,4, as amended by N3308. +// +// \param CCK Specifies whether to produce diagnostics if the function does not +// satisfy the requirements. +bool Sema::CheckConstexprFunctionDecl(const FunctionDecl *NewFD, + CheckConstexprKind CCK) { + assert((CCK != CCK_NoteNonConstexprInstantiation || + (NewFD->getTemplateInstantiationPattern() && + NewFD->getTemplateInstantiationPattern()->isConstexpr())) && + "only constexpr templates can be instantiated non-constexpr"); + + if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(NewFD)) { + // C++0x [dcl.constexpr]p4: + // In the definition of a constexpr constructor, each of the parameter + // types shall be a literal type. + if (!CheckConstexprParameterTypes(*this, NewFD, CCK)) + return false; + + // In addition, either its function-body shall be = delete or = default or + // it shall satisfy the following constraints: + // - the class shall not have any virtual base classes; + const CXXRecordDecl *RD = CD->getParent(); + if (RD->getNumVBases()) { + // Note, this is still illegal if the body is = default, since the + // implicit body does not satisfy the requirements of a constexpr + // constructor. We also reject cases where the body is = delete, as + // required by N3308. + if (CCK != CCK_Instantiation) { + Diag(NewFD->getLocation(), + CCK == CCK_Declaration ? diag::err_constexpr_virtual_base + : diag::note_constexpr_tmpl_virtual_base) + << RD->isStruct() << RD->getNumVBases(); + for (CXXRecordDecl::base_class_const_iterator I = RD->vbases_begin(), + E = RD->vbases_end(); I != E; ++I) + Diag(I->getSourceRange().getBegin(), + diag::note_constexpr_virtual_base_here) << I->getSourceRange(); + } + return false; + } + } else { + // C++0x [dcl.constexpr]p3: + // The definition of a constexpr function shall satisfy the following + // constraints: + // - it shall not be virtual; + const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD); + if (Method && Method->isVirtual()) { + if (CCK != CCK_Instantiation) { + Diag(NewFD->getLocation(), + CCK == CCK_Declaration ? diag::err_constexpr_virtual + : diag::note_constexpr_tmpl_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->getResultType(); + if (!RT->isDependentType() && + RequireLiteralType(NewFD->getLocation(), RT, CCK == CCK_Declaration ? + PDiag(diag::err_constexpr_non_literal_return) : + PDiag(), + /*AllowIncompleteType*/ true)) { + if (CCK == CCK_NoteNonConstexprInstantiation) + Diag(NewFD->getLocation(), + diag::note_constexpr_tmpl_non_literal_return) << RT; + return false; + } + + // - each of its parameter types shall be a literal type; + if (!CheckConstexprParameterTypes(*this, NewFD, CCK)) + return false; + } + + return true; +} + +/// Check the given declaration statement is legal within a constexpr function +/// body. C++0x [dcl.constexpr]p3,p4. +/// +/// \return true if the body is OK, false if we have diagnosed a problem. +static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl, + DeclStmt *DS) { + // C++0x [dcl.constexpr]p3 and p4: + // The definition of a constexpr function(p3) or constructor(p4) [...] shall + // contain only + for (DeclStmt::decl_iterator DclIt = DS->decl_begin(), + DclEnd = DS->decl_end(); DclIt != DclEnd; ++DclIt) { + switch ((*DclIt)->getKind()) { + case Decl::StaticAssert: + case Decl::Using: + case Decl::UsingShadow: + case Decl::UsingDirective: + case Decl::UnresolvedUsingTypename: + // - 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, + TypedefNameDecl *TN = cast<TypedefNameDecl>(*DclIt); + if (TN->getUnderlyingType()->isVariablyModifiedType()) { + // Don't allow variably-modified types in constexpr functions. + TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc(); + SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla) + << TL.getSourceRange() << TL.getType() + << isa<CXXConstructorDecl>(Dcl); + return false; + } + continue; + } + + case Decl::Enum: + case Decl::CXXRecord: + // As an extension, we allow the declaration (but not the definition) of + // classes and enumerations in all declarations, not just in typedef and + // alias declarations. + if (cast<TagDecl>(*DclIt)->isThisDeclarationADefinition()) { + SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_type_definition) + << isa<CXXConstructorDecl>(Dcl); + return false; + } + continue; + + case Decl::Var: + SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_var_declaration) + << isa<CXXConstructorDecl>(Dcl); + return false; + + default: + SemaRef.Diag(DS->getLocStart(), diag::err_constexpr_body_invalid_stmt) + << isa<CXXConstructorDecl>(Dcl); + return false; + } + } + + return true; +} + +/// Check that the given field is initialized within a constexpr constructor. +/// +/// \param Dcl The constexpr constructor being checked. +/// \param Field The field being checked. This may be a member of an anonymous +/// struct or union nested within the class being checked. +/// \param Inits All declarations, including anonymous struct/union members and +/// indirect members, for which any initialization was provided. +/// \param Diagnosed Set to true if an error is produced. +static void CheckConstexprCtorInitializer(Sema &SemaRef, + const FunctionDecl *Dcl, + FieldDecl *Field, + llvm::SmallSet<Decl*, 16> &Inits, + bool &Diagnosed) { + if (!Inits.count(Field)) { + if (!Diagnosed) { + SemaRef.Diag(Dcl->getLocation(), diag::err_constexpr_ctor_missing_init); + Diagnosed = true; + } + SemaRef.Diag(Field->getLocation(), diag::note_constexpr_ctor_missing_init); + } else if (Field->isAnonymousStructOrUnion()) { + const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl(); + for (RecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end(); + I != E; ++I) + // 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 body for the given constexpr function declaration only contains +/// the permitted types of statement. C++11 [dcl.constexpr]p3,p4. +/// +/// \return true if the body is OK, false if we have diagnosed a problem. +bool Sema::CheckConstexprFunctionBody(const FunctionDecl *Dcl, Stmt *Body) { + if (isa<CXXTryStmt>(Body)) { + // C++0x [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++0x [dcl.constexpr]p4: + // In the definition of a constexpr constructor, [...] + // - its function-body shall not be a function-try-block; + Diag(Body->getLocStart(), diag::err_constexpr_function_try_block) + << isa<CXXConstructorDecl>(Dcl); + return false; + } + + // - its function-body shall be [...] a compound-statement that contains only + CompoundStmt *CompBody = cast<CompoundStmt>(Body); + + llvm::SmallVector<SourceLocation, 4> ReturnStmts; + for (CompoundStmt::body_iterator BodyIt = CompBody->body_begin(), + BodyEnd = CompBody->body_end(); BodyIt != BodyEnd; ++BodyIt) { + switch ((*BodyIt)->getStmtClass()) { + case Stmt::NullStmtClass: + // - null statements, + continue; + + case Stmt::DeclStmtClass: + // - static_assert-declarations + // - using-declarations, + // - using-directives, + // - typedef declarations and alias-declarations that do not define + // classes or enumerations, + if (!CheckConstexprDeclStmt(*this, Dcl, cast<DeclStmt>(*BodyIt))) + return false; + continue; + + case Stmt::ReturnStmtClass: + // - and exactly one return statement; + if (isa<CXXConstructorDecl>(Dcl)) + break; + + ReturnStmts.push_back((*BodyIt)->getLocStart()); + // FIXME + // - every constructor call and implicit conversion used in initializing + // the return value shall be one of those allowed in a constant + // expression. + // Deal with this as part of a general check that the function can produce + // a constant expression (for [dcl.constexpr]p5). + continue; + + default: + break; + } + + Diag((*BodyIt)->getLocStart(), diag::err_constexpr_body_invalid_stmt) + << isa<CXXConstructorDecl>(Dcl); + return false; + } + + if (const CXXConstructorDecl *Constructor + = dyn_cast<CXXConstructorDecl>(Dcl)) { + const CXXRecordDecl *RD = Constructor->getParent(); + // - every non-static data member and base class sub-object shall be + // initialized; + if (RD->isUnion()) { + // DR1359: Exactly one member of a union shall be initialized. + if (Constructor->getNumCtorInitializers() == 0) { + Diag(Dcl->getLocation(), diag::err_constexpr_union_ctor_no_init); + return false; + } + } else if (!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; + } + } + if (AnyAnonStructUnionMembers || + Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) { + // Check initialization of non-static data members. Base classes are + // always initialized so do not need to be checked. Dependent bases + // might not have initializers in the member initializer list. + llvm::SmallSet<Decl*, 16> Inits; + for (CXXConstructorDecl::init_const_iterator + I = Constructor->init_begin(), E = Constructor->init_end(); + I != E; ++I) { + 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 (CXXRecordDecl::field_iterator I = RD->field_begin(), + E = RD->field_end(); I != E; ++I) + CheckConstexprCtorInitializer(*this, Dcl, *I, Inits, Diagnosed); + if (Diagnosed) + return false; + } + } + + // FIXME + // - every constructor involved in initializing non-static data members + // and base class sub-objects shall be a constexpr constructor; + // - every assignment-expression that is an initializer-clause appearing + // directly or indirectly within a brace-or-equal-initializer for + // a non-static data member that is not named by a mem-initializer-id + // shall be a constant expression; and + // - every implicit conversion used in converting a constructor argument + // to the corresponding parameter type and converting + // a full-expression to the corresponding member type shall be one of + // those allowed in a constant expression. + // Deal with these as part of a general check that the function can produce + // a constant expression (for [dcl.constexpr]p5). + } else { + if (ReturnStmts.empty()) { + Diag(Dcl->getLocation(), diag::err_constexpr_body_no_return); + return false; + } + if (ReturnStmts.size() > 1) { + Diag(ReturnStmts.back(), diag::err_constexpr_body_multiple_return); + for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I) + Diag(ReturnStmts[I], diag::note_constexpr_body_previous_return); + return false; + } + } + + 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 @@ -3226,6 +3593,47 @@ void Sema::CheckCompletedCXXClass(CXXRecordDecl *Record) { } } + // C++0x [dcl.constexpr]p8: A constexpr specifier for a non-static member + // function that is not a constructor declares that member function to be + // const. [...] The class of which that function is a member shall be + // a literal type. + // + // It's fine to diagnose constructors here too: such constructors cannot + // produce a constant expression, so are ill-formed (no diagnostic required). + // + // If the class has virtual bases, any constexpr members will already have + // been diagnosed by the checks performed on the member declaration, so + // suppress this (less useful) diagnostic. + if (LangOpts.CPlusPlus0x && !Record->isDependentType() && + !Record->isLiteral() && !Record->getNumVBases()) { + for (CXXRecordDecl::method_iterator M = Record->method_begin(), + MEnd = Record->method_end(); + M != MEnd; ++M) { + if ((*M)->isConstexpr()) { + switch (Record->getTemplateSpecializationKind()) { + case TSK_ImplicitInstantiation: + case TSK_ExplicitInstantiationDeclaration: + case TSK_ExplicitInstantiationDefinition: + // If a template instantiates to a non-literal type, but its members + // instantiate to constexpr functions, the template is technically + // ill-formed, but we allow it for sanity. Such members are treated as + // non-constexpr. + (*M)->setConstexpr(false); + continue; + + case TSK_Undeclared: + case TSK_ExplicitSpecialization: + RequireLiteralType((*M)->getLocation(), Context.getRecordType(Record), + PDiag(diag::err_constexpr_method_non_literal)); + break; + } + + // Only produce one error per class. + break; + } + } + } + // Declare inherited constructors. We do this eagerly here because: // - The standard requires an eager diagnostic for conflicting inherited // constructors from different classes. diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp index e29b75a2c2..694d94432f 100644 --- a/lib/Sema/SemaTemplateInstantiateDecl.cpp +++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp @@ -1067,15 +1067,12 @@ Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D, TemplateArgs); } - bool isConstexpr = D->isConstexpr(); - // FIXME: check whether the instantiation produces a constexpr function. - FunctionDecl *Function = FunctionDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(), D->getLocation(), D->getDeclName(), T, TInfo, D->getStorageClass(), D->getStorageClassAsWritten(), D->isInlineSpecified(), D->hasWrittenPrototype(), - isConstexpr); + /*isConstexpr*/ false); if (QualifierLoc) Function->setQualifierInfo(QualifierLoc); @@ -1388,9 +1385,6 @@ TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D, if (!DC) return 0; } - bool isConstexpr = D->isConstexpr(); - // FIXME: check whether the instantiation produces a constexpr function. - // Build the instantiated method declaration. CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); CXXMethodDecl *Method = 0; @@ -1403,7 +1397,7 @@ TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D, StartLoc, NameInfo, T, TInfo, Constructor->isExplicit(), Constructor->isInlineSpecified(), - false, isConstexpr); + false, /*isConstexpr*/ false); } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) { Method = CXXDestructorDecl::Create(SemaRef.Context, Record, StartLoc, NameInfo, T, TInfo, @@ -1414,14 +1408,15 @@ TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D, StartLoc, NameInfo, T, TInfo, Conversion->isInlineSpecified(), Conversion->isExplicit(), - isConstexpr, Conversion->getLocEnd()); + /*isConstexpr*/ false, + Conversion->getLocEnd()); } else { Method = CXXMethodDecl::Create(SemaRef.Context, Record, StartLoc, NameInfo, T, TInfo, D->isStatic(), D->getStorageClassAsWritten(), D->isInlineSpecified(), - isConstexpr, D->getLocEnd()); + /*isConstexpr*/ false, D->getLocEnd()); } if (QualifierLoc) @@ -2312,6 +2307,13 @@ TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New, EPI)); } + // C++0x [dcl.constexpr]p6: If the instantiated template specialization of + // a constexpr function template satisfies the requirements for a constexpr + // function, then it is a constexpr function. + if (Tmpl->isConstexpr() && + SemaRef.CheckConstexprFunctionDecl(New, Sema::CCK_Instantiation)) + New->setConstexpr(true); + const FunctionDecl* Definition = Tmpl; // Get the definition. Leaves the variable unchanged if undefined. diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp index 480dd3b85a..25ec0b1477 100644 --- a/lib/Sema/SemaType.cpp +++ b/lib/Sema/SemaType.cpp @@ -3992,6 +3992,118 @@ bool Sema::RequireCompleteType(SourceLocation Loc, QualType T, std::make_pair(SourceLocation(), PDiag(0))); } +/// @brief Ensure that the type T is a literal type. +/// +/// This routine checks whether the type @p T is a literal type. If @p T is an +/// incomplete type, an attempt is made to complete it. If @p T is a literal +/// type, or @p AllowIncompleteType is true and @p T is an incomplete type, +/// returns false. Otherwise, this routine issues the diagnostic @p PD (giving +/// it the type @p T), along with notes explaining why the type is not a +/// literal type, and returns true. +/// +/// @param Loc The location in the source that the non-literal type +/// diagnostic should refer to. +/// +/// @param T The type that this routine is examining for literalness. +/// +/// @param PD The partial diagnostic that will be printed out if T is not a +/// literal type. +/// +/// @param AllowIncompleteType If true, an incomplete type will be considered +/// acceptable. +/// +/// @returns @c true if @p T is not a literal type and a diagnostic was emitted, +/// @c false otherwise. +bool Sema::RequireLiteralType(SourceLocation Loc, QualType T, + const PartialDiagnostic &PD, + bool AllowIncompleteType) { + assert(!T->isDependentType() && "type should not be dependent"); + + bool Incomplete = RequireCompleteType(Loc, T, 0); + if (T->isLiteralType() || (AllowIncompleteType && Incomplete)) + return false; + + if (PD.getDiagID() == 0) + return true; + + Diag(Loc, PD) << T; + + if (T->isVariableArrayType()) + return true; + + const RecordType *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>(); + if (!RT) + return true; + + const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); + + // If the class has virtual base classes, then it's not an aggregate, and + // cannot have any constexpr constructors, so is non-literal. This is better + // to diagnose than the resulting absence of constexpr constructors. + if (RD->getNumVBases()) { + Diag(RD->getLocation(), diag::note_non_literal_virtual_base) + << RD->isStruct() << RD->getNumVBases(); + for (CXXRecordDecl::base_class_const_iterator I = RD->vbases_begin(), + E = RD->vbases_end(); I != E; ++I) + Diag(I->getSourceRange().getBegin(), + diag::note_constexpr_virtual_base_here) << I->getSourceRange(); + } else if (!RD->isAggregate() && !RD->hasConstexprNonCopyMoveConstructor()) { + Diag(RD->getLocation(), diag::note_non_literal_no_constexpr_ctors) << RD; + + switch (RD->getTemplateSpecializationKind()) { + case TSK_Undeclared: + case TSK_ExplicitSpecialization: + break; + + case TSK_ImplicitInstantiation: + case TSK_ExplicitInstantiationDeclaration: + case TSK_ExplicitInstantiationDefinition: + // If the base template had constexpr constructors which were + // instantiated as non-constexpr constructors, explain why. + for (CXXRecordDecl::ctor_iterator I = RD->ctor_begin(), + E = RD->ctor_end(); I != E; ++I) { + if ((*I)->isCopyConstructor() || (*I)->isMoveConstructor()) + continue; + + FunctionDecl *Base = (*I)->getInstantiatedFromMemberFunction(); + if (Base && Base->isConstexpr()) + CheckConstexprFunctionDecl(*I, CCK_NoteNonConstexprInstantiation); + } + } + } else if (RD->hasNonLiteralTypeFieldsOrBases()) { + for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(), + E = RD->bases_end(); I != E; ++I) { + if (!I->getType()->isLiteralType()) { + Diag(I->getSourceRange().getBegin(), + diag::note_non_literal_base_class) + << RD << I->getType() << I->getSourceRange(); + return true; + } + } + for (CXXRecordDecl::field_iterator I = RD->field_begin(), + E = RD->field_end(); I != E; ++I) { + if (!(*I)->getType()->isLiteralType()) { + Diag((*I)->getLocation(), diag::note_non_literal_field) + << RD << (*I) << (*I)->getType(); + return true; + } + } + } else if (!RD->hasTrivialDestructor()) { + // All fields and bases are of literal types, so have trivial destructors. + // If this class's destructor is non-trivial it must be user-declared. + CXXDestructorDecl *Dtor = RD->getDestructor(); + assert(Dtor && "class has literal fields and bases but no dtor?"); + if (!Dtor) + return true; + + Diag(Dtor->getLocation(), Dtor->isUserProvided() ? + diag::note_non_literal_user_provided_dtor : + diag::note_non_literal_nontrivial_dtor) << RD; + } + + return true; +} + /// \brief Retrieve a version of the type 'T' that is elaborated by Keyword /// and qualified by the nested-name-specifier contained in SS. QualType Sema::getElaboratedType(ElaboratedTypeKeyword Keyword, |