diff options
Diffstat (limited to 'clang/lib/Sema/SemaExprCXX.cpp')
| -rw-r--r-- | clang/lib/Sema/SemaExprCXX.cpp | 8092 |
1 files changed, 8092 insertions, 0 deletions
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp new file mode 100644 index 000000000000..9aae9289b514 --- /dev/null +++ b/clang/lib/Sema/SemaExprCXX.cpp @@ -0,0 +1,8092 @@ +//===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +/// +/// \file +/// Implements semantic analysis for C++ expressions. +/// +//===----------------------------------------------------------------------===// + +#include "clang/Sema/SemaInternal.h" +#include "TreeTransform.h" +#include "TypeLocBuilder.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/ASTLambda.h" +#include "clang/AST/CXXInheritance.h" +#include "clang/AST/CharUnits.h" +#include "clang/AST/DeclObjC.h" +#include "clang/AST/ExprCXX.h" +#include "clang/AST/ExprObjC.h" +#include "clang/AST/RecursiveASTVisitor.h" +#include "clang/AST/TypeLoc.h" +#include "clang/Basic/AlignedAllocation.h" +#include "clang/Basic/PartialDiagnostic.h" +#include "clang/Basic/TargetInfo.h" +#include "clang/Lex/Preprocessor.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/SemaLambda.h" +#include "clang/Sema/TemplateDeduction.h" +#include "llvm/ADT/APInt.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/Support/ErrorHandling.h" +using namespace clang; +using namespace sema; + +/// Handle the result of the special case name lookup for inheriting +/// constructor declarations. 'NS::X::X' and 'NS::X<...>::X' are treated as +/// constructor names in member using declarations, even if 'X' is not the +/// name of the corresponding type. +ParsedType Sema::getInheritingConstructorName(CXXScopeSpec &SS, + SourceLocation NameLoc, + IdentifierInfo &Name) { + NestedNameSpecifier *NNS = SS.getScopeRep(); + + // Convert the nested-name-specifier into a type. + QualType Type; + switch (NNS->getKind()) { + case NestedNameSpecifier::TypeSpec: + case NestedNameSpecifier::TypeSpecWithTemplate: + Type = QualType(NNS->getAsType(), 0); + break; + + case NestedNameSpecifier::Identifier: + // Strip off the last layer of the nested-name-specifier and build a + // typename type for it. + assert(NNS->getAsIdentifier() == &Name && "not a constructor name"); + Type = Context.getDependentNameType(ETK_None, NNS->getPrefix(), + NNS->getAsIdentifier()); + break; + + case NestedNameSpecifier::Global: + case NestedNameSpecifier::Super: + case NestedNameSpecifier::Namespace: + case NestedNameSpecifier::NamespaceAlias: + llvm_unreachable("Nested name specifier is not a type for inheriting ctor"); + } + + // This reference to the type is located entirely at the location of the + // final identifier in the qualified-id. + return CreateParsedType(Type, + Context.getTrivialTypeSourceInfo(Type, NameLoc)); +} + +ParsedType Sema::getConstructorName(IdentifierInfo &II, + SourceLocation NameLoc, + Scope *S, CXXScopeSpec &SS, + bool EnteringContext) { + CXXRecordDecl *CurClass = getCurrentClass(S, &SS); + assert(CurClass && &II == CurClass->getIdentifier() && + "not a constructor name"); + + // When naming a constructor as a member of a dependent context (eg, in a + // friend declaration or an inherited constructor declaration), form an + // unresolved "typename" type. + if (CurClass->isDependentContext() && !EnteringContext && SS.getScopeRep()) { + QualType T = Context.getDependentNameType(ETK_None, SS.getScopeRep(), &II); + return ParsedType::make(T); + } + + if (SS.isNotEmpty() && RequireCompleteDeclContext(SS, CurClass)) + return ParsedType(); + + // Find the injected-class-name declaration. Note that we make no attempt to + // diagnose cases where the injected-class-name is shadowed: the only + // declaration that can validly shadow the injected-class-name is a + // non-static data member, and if the class contains both a non-static data + // member and a constructor then it is ill-formed (we check that in + // CheckCompletedCXXClass). + CXXRecordDecl *InjectedClassName = nullptr; + for (NamedDecl *ND : CurClass->lookup(&II)) { + auto *RD = dyn_cast<CXXRecordDecl>(ND); + if (RD && RD->isInjectedClassName()) { + InjectedClassName = RD; + break; + } + } + if (!InjectedClassName) { + if (!CurClass->isInvalidDecl()) { + // FIXME: RequireCompleteDeclContext doesn't check dependent contexts + // properly. Work around it here for now. + Diag(SS.getLastQualifierNameLoc(), + diag::err_incomplete_nested_name_spec) << CurClass << SS.getRange(); + } + return ParsedType(); + } + + QualType T = Context.getTypeDeclType(InjectedClassName); + DiagnoseUseOfDecl(InjectedClassName, NameLoc); + MarkAnyDeclReferenced(NameLoc, InjectedClassName, /*OdrUse=*/false); + + return ParsedType::make(T); +} + +ParsedType Sema::getDestructorName(SourceLocation TildeLoc, + IdentifierInfo &II, + SourceLocation NameLoc, + Scope *S, CXXScopeSpec &SS, + ParsedType ObjectTypePtr, + bool EnteringContext) { + // Determine where to perform name lookup. + + // FIXME: This area of the standard is very messy, and the current + // wording is rather unclear about which scopes we search for the + // destructor name; see core issues 399 and 555. Issue 399 in + // particular shows where the current description of destructor name + // lookup is completely out of line with existing practice, e.g., + // this appears to be ill-formed: + // + // namespace N { + // template <typename T> struct S { + // ~S(); + // }; + // } + // + // void f(N::S<int>* s) { + // s->N::S<int>::~S(); + // } + // + // See also PR6358 and PR6359. + // For this reason, we're currently only doing the C++03 version of this + // code; the C++0x version has to wait until we get a proper spec. + QualType SearchType; + DeclContext *LookupCtx = nullptr; + bool isDependent = false; + bool LookInScope = false; + + if (SS.isInvalid()) + return nullptr; + + // If we have an object type, it's because we are in a + // pseudo-destructor-expression or a member access expression, and + // we know what type we're looking for. + if (ObjectTypePtr) + SearchType = GetTypeFromParser(ObjectTypePtr); + + if (SS.isSet()) { + NestedNameSpecifier *NNS = SS.getScopeRep(); + + bool AlreadySearched = false; + bool LookAtPrefix = true; + // C++11 [basic.lookup.qual]p6: + // If a pseudo-destructor-name (5.2.4) contains a nested-name-specifier, + // the type-names are looked up as types in the scope designated by the + // nested-name-specifier. Similarly, in a qualified-id of the form: + // + // nested-name-specifier[opt] class-name :: ~ class-name + // + // the second class-name is looked up in the same scope as the first. + // + // Here, we determine whether the code below is permitted to look at the + // prefix of the nested-name-specifier. + DeclContext *DC = computeDeclContext(SS, EnteringContext); + if (DC && DC->isFileContext()) { + AlreadySearched = true; + LookupCtx = DC; + isDependent = false; + } else if (DC && isa<CXXRecordDecl>(DC)) { + LookAtPrefix = false; + LookInScope = true; + } + + // The second case from the C++03 rules quoted further above. + NestedNameSpecifier *Prefix = nullptr; + if (AlreadySearched) { + // Nothing left to do. + } else if (LookAtPrefix && (Prefix = NNS->getPrefix())) { + CXXScopeSpec PrefixSS; + PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data())); + LookupCtx = computeDeclContext(PrefixSS, EnteringContext); + isDependent = isDependentScopeSpecifier(PrefixSS); + } else if (ObjectTypePtr) { + LookupCtx = computeDeclContext(SearchType); + isDependent = SearchType->isDependentType(); + } else { + LookupCtx = computeDeclContext(SS, EnteringContext); + isDependent = LookupCtx && LookupCtx->isDependentContext(); + } + } else if (ObjectTypePtr) { + // C++ [basic.lookup.classref]p3: + // If the unqualified-id is ~type-name, the type-name is looked up + // in the context of the entire postfix-expression. If the type T + // of the object expression is of a class type C, the type-name is + // also looked up in the scope of class C. At least one of the + // lookups shall find a name that refers to (possibly + // cv-qualified) T. + LookupCtx = computeDeclContext(SearchType); + isDependent = SearchType->isDependentType(); + assert((isDependent || !SearchType->isIncompleteType()) && + "Caller should have completed object type"); + + LookInScope = true; + } else { + // Perform lookup into the current scope (only). + LookInScope = true; + } + + TypeDecl *NonMatchingTypeDecl = nullptr; + LookupResult Found(*this, &II, NameLoc, LookupOrdinaryName); + for (unsigned Step = 0; Step != 2; ++Step) { + // Look for the name first in the computed lookup context (if we + // have one) and, if that fails to find a match, in the scope (if + // we're allowed to look there). + Found.clear(); + if (Step == 0 && LookupCtx) { + if (RequireCompleteDeclContext(SS, LookupCtx)) + return nullptr; + LookupQualifiedName(Found, LookupCtx); + } else if (Step == 1 && LookInScope && S) { + LookupName(Found, S); + } else { + continue; + } + + // FIXME: Should we be suppressing ambiguities here? + if (Found.isAmbiguous()) + return nullptr; + + if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) { + QualType T = Context.getTypeDeclType(Type); + MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false); + + if (SearchType.isNull() || SearchType->isDependentType() || + Context.hasSameUnqualifiedType(T, SearchType)) { + // We found our type! + + return CreateParsedType(T, + Context.getTrivialTypeSourceInfo(T, NameLoc)); + } + + if (!SearchType.isNull()) + NonMatchingTypeDecl = Type; + } + + // If the name that we found is a class template name, and it is + // the same name as the template name in the last part of the + // nested-name-specifier (if present) or the object type, then + // this is the destructor for that class. + // FIXME: This is a workaround until we get real drafting for core + // issue 399, for which there isn't even an obvious direction. + if (ClassTemplateDecl *Template = Found.getAsSingle<ClassTemplateDecl>()) { + QualType MemberOfType; + if (SS.isSet()) { + if (DeclContext *Ctx = computeDeclContext(SS, EnteringContext)) { + // Figure out the type of the context, if it has one. + if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx)) + MemberOfType = Context.getTypeDeclType(Record); + } + } + if (MemberOfType.isNull()) + MemberOfType = SearchType; + + if (MemberOfType.isNull()) + continue; + + // We're referring into a class template specialization. If the + // class template we found is the same as the template being + // specialized, we found what we are looking for. + if (const RecordType *Record = MemberOfType->getAs<RecordType>()) { + if (ClassTemplateSpecializationDecl *Spec + = dyn_cast<ClassTemplateSpecializationDecl>(Record->getDecl())) { + if (Spec->getSpecializedTemplate()->getCanonicalDecl() == + Template->getCanonicalDecl()) + return CreateParsedType( + MemberOfType, + Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc)); + } + + continue; + } + + // We're referring to an unresolved class template + // specialization. Determine whether we class template we found + // is the same as the template being specialized or, if we don't + // know which template is being specialized, that it at least + // has the same name. + if (const TemplateSpecializationType *SpecType + = MemberOfType->getAs<TemplateSpecializationType>()) { + TemplateName SpecName = SpecType->getTemplateName(); + + // The class template we found is the same template being + // specialized. + if (TemplateDecl *SpecTemplate = SpecName.getAsTemplateDecl()) { + if (SpecTemplate->getCanonicalDecl() == Template->getCanonicalDecl()) + return CreateParsedType( + MemberOfType, + Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc)); + + continue; + } + + // The class template we found has the same name as the + // (dependent) template name being specialized. + if (DependentTemplateName *DepTemplate + = SpecName.getAsDependentTemplateName()) { + if (DepTemplate->isIdentifier() && + DepTemplate->getIdentifier() == Template->getIdentifier()) + return CreateParsedType( + MemberOfType, + Context.getTrivialTypeSourceInfo(MemberOfType, NameLoc)); + + continue; + } + } + } + } + + if (isDependent) { + // We didn't find our type, but that's okay: it's dependent + // anyway. + + // FIXME: What if we have no nested-name-specifier? + QualType T = CheckTypenameType(ETK_None, SourceLocation(), + SS.getWithLocInContext(Context), + II, NameLoc); + return ParsedType::make(T); + } + + if (NonMatchingTypeDecl) { + QualType T = Context.getTypeDeclType(NonMatchingTypeDecl); + Diag(NameLoc, diag::err_destructor_expr_type_mismatch) + << T << SearchType; + Diag(NonMatchingTypeDecl->getLocation(), diag::note_destructor_type_here) + << T; + } else if (ObjectTypePtr) + Diag(NameLoc, diag::err_ident_in_dtor_not_a_type) + << &II; + else { + SemaDiagnosticBuilder DtorDiag = Diag(NameLoc, + diag::err_destructor_class_name); + if (S) { + const DeclContext *Ctx = S->getEntity(); + if (const CXXRecordDecl *Class = dyn_cast_or_null<CXXRecordDecl>(Ctx)) + DtorDiag << FixItHint::CreateReplacement(SourceRange(NameLoc), + Class->getNameAsString()); + } + } + + return nullptr; +} + +ParsedType Sema::getDestructorTypeForDecltype(const DeclSpec &DS, + ParsedType ObjectType) { + if (DS.getTypeSpecType() == DeclSpec::TST_error) + return nullptr; + + if (DS.getTypeSpecType() == DeclSpec::TST_decltype_auto) { + Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid); + return nullptr; + } + + assert(DS.getTypeSpecType() == DeclSpec::TST_decltype && + "unexpected type in getDestructorType"); + QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); + + // If we know the type of the object, check that the correct destructor + // type was named now; we can give better diagnostics this way. + QualType SearchType = GetTypeFromParser(ObjectType); + if (!SearchType.isNull() && !SearchType->isDependentType() && + !Context.hasSameUnqualifiedType(T, SearchType)) { + Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch) + << T << SearchType; + return nullptr; + } + + return ParsedType::make(T); +} + +bool Sema::checkLiteralOperatorId(const CXXScopeSpec &SS, + const UnqualifiedId &Name) { + assert(Name.getKind() == UnqualifiedIdKind::IK_LiteralOperatorId); + + if (!SS.isValid()) + return false; + + switch (SS.getScopeRep()->getKind()) { + case NestedNameSpecifier::Identifier: + case NestedNameSpecifier::TypeSpec: + case NestedNameSpecifier::TypeSpecWithTemplate: + // Per C++11 [over.literal]p2, literal operators can only be declared at + // namespace scope. Therefore, this unqualified-id cannot name anything. + // Reject it early, because we have no AST representation for this in the + // case where the scope is dependent. + Diag(Name.getBeginLoc(), diag::err_literal_operator_id_outside_namespace) + << SS.getScopeRep(); + return true; + + case NestedNameSpecifier::Global: + case NestedNameSpecifier::Super: + case NestedNameSpecifier::Namespace: + case NestedNameSpecifier::NamespaceAlias: + return false; + } + + llvm_unreachable("unknown nested name specifier kind"); +} + +/// Build a C++ typeid expression with a type operand. +ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType, + SourceLocation TypeidLoc, + TypeSourceInfo *Operand, + SourceLocation RParenLoc) { + // C++ [expr.typeid]p4: + // The top-level cv-qualifiers of the lvalue expression or the type-id + // that is the operand of typeid are always ignored. + // If the type of the type-id is a class type or a reference to a class + // type, the class shall be completely-defined. + Qualifiers Quals; + QualType T + = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(), + Quals); + if (T->getAs<RecordType>() && + RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid)) + return ExprError(); + + if (T->isVariablyModifiedType()) + return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << T); + + if (CheckQualifiedFunctionForTypeId(T, TypeidLoc)) + return ExprError(); + + return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand, + SourceRange(TypeidLoc, RParenLoc)); +} + +/// Build a C++ typeid expression with an expression operand. +ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType, + SourceLocation TypeidLoc, + Expr *E, + SourceLocation RParenLoc) { + bool WasEvaluated = false; + if (E && !E->isTypeDependent()) { + if (E->getType()->isPlaceholderType()) { + ExprResult result = CheckPlaceholderExpr(E); + if (result.isInvalid()) return ExprError(); + E = result.get(); + } + + QualType T = E->getType(); + if (const RecordType *RecordT = T->getAs<RecordType>()) { + CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl()); + // C++ [expr.typeid]p3: + // [...] If the type of the expression is a class type, the class + // shall be completely-defined. + if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid)) + return ExprError(); + + // C++ [expr.typeid]p3: + // When typeid is applied to an expression other than an glvalue of a + // polymorphic class type [...] [the] expression is an unevaluated + // operand. [...] + if (RecordD->isPolymorphic() && E->isGLValue()) { + // The subexpression is potentially evaluated; switch the context + // and recheck the subexpression. + ExprResult Result = TransformToPotentiallyEvaluated(E); + if (Result.isInvalid()) return ExprError(); + E = Result.get(); + + // We require a vtable to query the type at run time. + MarkVTableUsed(TypeidLoc, RecordD); + WasEvaluated = true; + } + } + + ExprResult Result = CheckUnevaluatedOperand(E); + if (Result.isInvalid()) + return ExprError(); + E = Result.get(); + + // C++ [expr.typeid]p4: + // [...] If the type of the type-id is a reference to a possibly + // cv-qualified type, the result of the typeid expression refers to a + // std::type_info object representing the cv-unqualified referenced + // type. + Qualifiers Quals; + QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals); + if (!Context.hasSameType(T, UnqualT)) { + T = UnqualT; + E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).get(); + } + } + + if (E->getType()->isVariablyModifiedType()) + return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) + << E->getType()); + else if (!inTemplateInstantiation() && + E->HasSideEffects(Context, WasEvaluated)) { + // The expression operand for typeid is in an unevaluated expression + // context, so side effects could result in unintended consequences. + Diag(E->getExprLoc(), WasEvaluated + ? diag::warn_side_effects_typeid + : diag::warn_side_effects_unevaluated_context); + } + + return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), E, + SourceRange(TypeidLoc, RParenLoc)); +} + +/// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression); +ExprResult +Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc, + bool isType, void *TyOrExpr, SourceLocation RParenLoc) { + // typeid is not supported in OpenCL. + if (getLangOpts().OpenCLCPlusPlus) { + return ExprError(Diag(OpLoc, diag::err_openclcxx_not_supported) + << "typeid"); + } + + // Find the std::type_info type. + if (!getStdNamespace()) + return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); + + if (!CXXTypeInfoDecl) { + IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info"); + LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName); + LookupQualifiedName(R, getStdNamespace()); + CXXTypeInfoDecl = R.getAsSingle<RecordDecl>(); + // Microsoft's typeinfo doesn't have type_info in std but in the global + // namespace if _HAS_EXCEPTIONS is defined to 0. See PR13153. + if (!CXXTypeInfoDecl && LangOpts.MSVCCompat) { + LookupQualifiedName(R, Context.getTranslationUnitDecl()); + CXXTypeInfoDecl = R.getAsSingle<RecordDecl>(); + } + if (!CXXTypeInfoDecl) + return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid)); + } + + if (!getLangOpts().RTTI) { + return ExprError(Diag(OpLoc, diag::err_no_typeid_with_fno_rtti)); + } + + QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl); + + if (isType) { + // The operand is a type; handle it as such. + TypeSourceInfo *TInfo = nullptr; + QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr), + &TInfo); + if (T.isNull()) + return ExprError(); + + if (!TInfo) + TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc); + + return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc); + } + + // The operand is an expression. + return BuildCXXTypeId(TypeInfoType, OpLoc, (Expr*)TyOrExpr, RParenLoc); +} + +/// Grabs __declspec(uuid()) off a type, or returns 0 if we cannot resolve to +/// a single GUID. +static void +getUuidAttrOfType(Sema &SemaRef, QualType QT, + llvm::SmallSetVector<const UuidAttr *, 1> &UuidAttrs) { + // Optionally remove one level of pointer, reference or array indirection. + const Type *Ty = QT.getTypePtr(); + if (QT->isPointerType() || QT->isReferenceType()) + Ty = QT->getPointeeType().getTypePtr(); + else if (QT->isArrayType()) + Ty = Ty->getBaseElementTypeUnsafe(); + + const auto *TD = Ty->getAsTagDecl(); + if (!TD) + return; + + if (const auto *Uuid = TD->getMostRecentDecl()->getAttr<UuidAttr>()) { + UuidAttrs.insert(Uuid); + return; + } + + // __uuidof can grab UUIDs from template arguments. + if (const auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(TD)) { + const TemplateArgumentList &TAL = CTSD->getTemplateArgs(); + for (const TemplateArgument &TA : TAL.asArray()) { + const UuidAttr *UuidForTA = nullptr; + if (TA.getKind() == TemplateArgument::Type) + getUuidAttrOfType(SemaRef, TA.getAsType(), UuidAttrs); + else if (TA.getKind() == TemplateArgument::Declaration) + getUuidAttrOfType(SemaRef, TA.getAsDecl()->getType(), UuidAttrs); + + if (UuidForTA) + UuidAttrs.insert(UuidForTA); + } + } +} + +/// Build a Microsoft __uuidof expression with a type operand. +ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType, + SourceLocation TypeidLoc, + TypeSourceInfo *Operand, + SourceLocation RParenLoc) { + StringRef UuidStr; + if (!Operand->getType()->isDependentType()) { + llvm::SmallSetVector<const UuidAttr *, 1> UuidAttrs; + getUuidAttrOfType(*this, Operand->getType(), UuidAttrs); + if (UuidAttrs.empty()) + return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid)); + if (UuidAttrs.size() > 1) + return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids)); + UuidStr = UuidAttrs.back()->getGuid(); + } + + return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), Operand, UuidStr, + SourceRange(TypeidLoc, RParenLoc)); +} + +/// Build a Microsoft __uuidof expression with an expression operand. +ExprResult Sema::BuildCXXUuidof(QualType TypeInfoType, + SourceLocation TypeidLoc, + Expr *E, + SourceLocation RParenLoc) { + StringRef UuidStr; + if (!E->getType()->isDependentType()) { + if (E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { + UuidStr = "00000000-0000-0000-0000-000000000000"; + } else { + llvm::SmallSetVector<const UuidAttr *, 1> UuidAttrs; + getUuidAttrOfType(*this, E->getType(), UuidAttrs); + if (UuidAttrs.empty()) + return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid)); + if (UuidAttrs.size() > 1) + return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids)); + UuidStr = UuidAttrs.back()->getGuid(); + } + } + + return new (Context) CXXUuidofExpr(TypeInfoType.withConst(), E, UuidStr, + SourceRange(TypeidLoc, RParenLoc)); +} + +/// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression); +ExprResult +Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc, + bool isType, void *TyOrExpr, SourceLocation RParenLoc) { + // If MSVCGuidDecl has not been cached, do the lookup. + if (!MSVCGuidDecl) { + IdentifierInfo *GuidII = &PP.getIdentifierTable().get("_GUID"); + LookupResult R(*this, GuidII, SourceLocation(), LookupTagName); + LookupQualifiedName(R, Context.getTranslationUnitDecl()); + MSVCGuidDecl = R.getAsSingle<RecordDecl>(); + if (!MSVCGuidDecl) + return ExprError(Diag(OpLoc, diag::err_need_header_before_ms_uuidof)); + } + + QualType GuidType = Context.getTypeDeclType(MSVCGuidDecl); + + if (isType) { + // The operand is a type; handle it as such. + TypeSourceInfo *TInfo = nullptr; + QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr), + &TInfo); + if (T.isNull()) + return ExprError(); + + if (!TInfo) + TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc); + + return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc); + } + + // The operand is an expression. + return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc); +} + +/// ActOnCXXBoolLiteral - Parse {true,false} literals. +ExprResult +Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) { + assert((Kind == tok::kw_true || Kind == tok::kw_false) && + "Unknown C++ Boolean value!"); + return new (Context) + CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc); +} + +/// ActOnCXXNullPtrLiteral - Parse 'nullptr'. +ExprResult +Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) { + return new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc); +} + +/// ActOnCXXThrow - Parse throw expressions. +ExprResult +Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) { + bool IsThrownVarInScope = false; + if (Ex) { + // C++0x [class.copymove]p31: + // When certain criteria are met, an implementation is allowed to omit the + // copy/move construction of a class object [...] + // + // - in a throw-expression, when the operand is the name of a + // non-volatile automatic object (other than a function or catch- + // clause parameter) whose scope does not extend beyond the end of the + // innermost enclosing try-block (if there is one), the copy/move + // operation from the operand to the exception object (15.1) can be + // omitted by constructing the automatic object directly into the + // exception object + if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens())) + if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) { + if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) { + for( ; S; S = S->getParent()) { + if (S->isDeclScope(Var)) { + IsThrownVarInScope = true; + break; + } + + if (S->getFlags() & + (Scope::FnScope | Scope::ClassScope | Scope::BlockScope | + Scope::FunctionPrototypeScope | Scope::ObjCMethodScope | + Scope::TryScope)) + break; + } + } + } + } + + return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope); +} + +ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex, + bool IsThrownVarInScope) { + // Don't report an error if 'throw' is used in system headers. + if (!getLangOpts().CXXExceptions && + !getSourceManager().isInSystemHeader(OpLoc) && !getLangOpts().CUDA) { + // Delay error emission for the OpenMP device code. + targetDiag(OpLoc, diag::err_exceptions_disabled) << "throw"; + } + + // Exceptions aren't allowed in CUDA device code. + if (getLangOpts().CUDA) + CUDADiagIfDeviceCode(OpLoc, diag::err_cuda_device_exceptions) + << "throw" << CurrentCUDATarget(); + + if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope()) + Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw"; + + if (Ex && !Ex->isTypeDependent()) { + QualType ExceptionObjectTy = Context.getExceptionObjectType(Ex->getType()); + if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex)) + return ExprError(); + + // Initialize the exception result. This implicitly weeds out + // abstract types or types with inaccessible copy constructors. + + // C++0x [class.copymove]p31: + // When certain criteria are met, an implementation is allowed to omit the + // copy/move construction of a class object [...] + // + // - in a throw-expression, when the operand is the name of a + // non-volatile automatic object (other than a function or + // catch-clause + // parameter) whose scope does not extend beyond the end of the + // innermost enclosing try-block (if there is one), the copy/move + // operation from the operand to the exception object (15.1) can be + // omitted by constructing the automatic object directly into the + // exception object + const VarDecl *NRVOVariable = nullptr; + if (IsThrownVarInScope) + NRVOVariable = getCopyElisionCandidate(QualType(), Ex, CES_Strict); + + InitializedEntity Entity = InitializedEntity::InitializeException( + OpLoc, ExceptionObjectTy, + /*NRVO=*/NRVOVariable != nullptr); + ExprResult Res = PerformMoveOrCopyInitialization( + Entity, NRVOVariable, QualType(), Ex, IsThrownVarInScope); + if (Res.isInvalid()) + return ExprError(); + Ex = Res.get(); + } + + return new (Context) + CXXThrowExpr(Ex, Context.VoidTy, OpLoc, IsThrownVarInScope); +} + +static void +collectPublicBases(CXXRecordDecl *RD, + llvm::DenseMap<CXXRecordDecl *, unsigned> &SubobjectsSeen, + llvm::SmallPtrSetImpl<CXXRecordDecl *> &VBases, + llvm::SetVector<CXXRecordDecl *> &PublicSubobjectsSeen, + bool ParentIsPublic) { + for (const CXXBaseSpecifier &BS : RD->bases()) { + CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl(); + bool NewSubobject; + // Virtual bases constitute the same subobject. Non-virtual bases are + // always distinct subobjects. + if (BS.isVirtual()) + NewSubobject = VBases.insert(BaseDecl).second; + else + NewSubobject = true; + + if (NewSubobject) + ++SubobjectsSeen[BaseDecl]; + + // Only add subobjects which have public access throughout the entire chain. + bool PublicPath = ParentIsPublic && BS.getAccessSpecifier() == AS_public; + if (PublicPath) + PublicSubobjectsSeen.insert(BaseDecl); + + // Recurse on to each base subobject. + collectPublicBases(BaseDecl, SubobjectsSeen, VBases, PublicSubobjectsSeen, + PublicPath); + } +} + +static void getUnambiguousPublicSubobjects( + CXXRecordDecl *RD, llvm::SmallVectorImpl<CXXRecordDecl *> &Objects) { + llvm::DenseMap<CXXRecordDecl *, unsigned> SubobjectsSeen; + llvm::SmallSet<CXXRecordDecl *, 2> VBases; + llvm::SetVector<CXXRecordDecl *> PublicSubobjectsSeen; + SubobjectsSeen[RD] = 1; + PublicSubobjectsSeen.insert(RD); + collectPublicBases(RD, SubobjectsSeen, VBases, PublicSubobjectsSeen, + /*ParentIsPublic=*/true); + + for (CXXRecordDecl *PublicSubobject : PublicSubobjectsSeen) { + // Skip ambiguous objects. + if (SubobjectsSeen[PublicSubobject] > 1) + continue; + + Objects.push_back(PublicSubobject); + } +} + +/// CheckCXXThrowOperand - Validate the operand of a throw. +bool Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc, + QualType ExceptionObjectTy, Expr *E) { + // If the type of the exception would be an incomplete type or a pointer + // to an incomplete type other than (cv) void the program is ill-formed. + QualType Ty = ExceptionObjectTy; + bool isPointer = false; + if (const PointerType* Ptr = Ty->getAs<PointerType>()) { + Ty = Ptr->getPointeeType(); + isPointer = true; + } + if (!isPointer || !Ty->isVoidType()) { + if (RequireCompleteType(ThrowLoc, Ty, + isPointer ? diag::err_throw_incomplete_ptr + : diag::err_throw_incomplete, + E->getSourceRange())) + return true; + + if (RequireNonAbstractType(ThrowLoc, ExceptionObjectTy, + diag::err_throw_abstract_type, E)) + return true; + } + + // If the exception has class type, we need additional handling. + CXXRecordDecl *RD = Ty->getAsCXXRecordDecl(); + if (!RD) + return false; + + // If we are throwing a polymorphic class type or pointer thereof, + // exception handling will make use of the vtable. + MarkVTableUsed(ThrowLoc, RD); + + // If a pointer is thrown, the referenced object will not be destroyed. + if (isPointer) + return false; + + // If the class has a destructor, we must be able to call it. + if (!RD->hasIrrelevantDestructor()) { + if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) { + MarkFunctionReferenced(E->getExprLoc(), Destructor); + CheckDestructorAccess(E->getExprLoc(), Destructor, + PDiag(diag::err_access_dtor_exception) << Ty); + if (DiagnoseUseOfDecl(Destructor, E->getExprLoc())) + return true; + } + } + + // The MSVC ABI creates a list of all types which can catch the exception + // object. This list also references the appropriate copy constructor to call + // if the object is caught by value and has a non-trivial copy constructor. + if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { + // We are only interested in the public, unambiguous bases contained within + // the exception object. Bases which are ambiguous or otherwise + // inaccessible are not catchable types. + llvm::SmallVector<CXXRecordDecl *, 2> UnambiguousPublicSubobjects; + getUnambiguousPublicSubobjects(RD, UnambiguousPublicSubobjects); + + for (CXXRecordDecl *Subobject : UnambiguousPublicSubobjects) { + // Attempt to lookup the copy constructor. Various pieces of machinery + // will spring into action, like template instantiation, which means this + // cannot be a simple walk of the class's decls. Instead, we must perform + // lookup and overload resolution. + CXXConstructorDecl *CD = LookupCopyingConstructor(Subobject, 0); + if (!CD) + continue; + + // Mark the constructor referenced as it is used by this throw expression. + MarkFunctionReferenced(E->getExprLoc(), CD); + + // Skip this copy constructor if it is trivial, we don't need to record it + // in the catchable type data. + if (CD->isTrivial()) + continue; + + // The copy constructor is non-trivial, create a mapping from this class + // type to this constructor. + // N.B. The selection of copy constructor is not sensitive to this + // particular throw-site. Lookup will be performed at the catch-site to + // ensure that the copy constructor is, in fact, accessible (via + // friendship or any other means). + Context.addCopyConstructorForExceptionObject(Subobject, CD); + + // We don't keep the instantiated default argument expressions around so + // we must rebuild them here. + for (unsigned I = 1, E = CD->getNumParams(); I != E; ++I) { + if (CheckCXXDefaultArgExpr(ThrowLoc, CD, CD->getParamDecl(I))) + return true; + } + } + } + + // Under the Itanium C++ ABI, memory for the exception object is allocated by + // the runtime with no ability for the compiler to request additional + // alignment. Warn if the exception type requires alignment beyond the minimum + // guaranteed by the target C++ runtime. + if (Context.getTargetInfo().getCXXABI().isItaniumFamily()) { + CharUnits TypeAlign = Context.getTypeAlignInChars(Ty); + CharUnits ExnObjAlign = Context.getExnObjectAlignment(); + if (ExnObjAlign < TypeAlign) { + Diag(ThrowLoc, diag::warn_throw_underaligned_obj); + Diag(ThrowLoc, diag::note_throw_underaligned_obj) + << Ty << (unsigned)TypeAlign.getQuantity() + << (unsigned)ExnObjAlign.getQuantity(); + } + } + + return false; +} + +static QualType adjustCVQualifiersForCXXThisWithinLambda( + ArrayRef<FunctionScopeInfo *> FunctionScopes, QualType ThisTy, + DeclContext *CurSemaContext, ASTContext &ASTCtx) { + + QualType ClassType = ThisTy->getPointeeType(); + LambdaScopeInfo *CurLSI = nullptr; + DeclContext *CurDC = CurSemaContext; + + // Iterate through the stack of lambdas starting from the innermost lambda to + // the outermost lambda, checking if '*this' is ever captured by copy - since + // that could change the cv-qualifiers of the '*this' object. + // The object referred to by '*this' starts out with the cv-qualifiers of its + // member function. We then start with the innermost lambda and iterate + // outward checking to see if any lambda performs a by-copy capture of '*this' + // - and if so, any nested lambda must respect the 'constness' of that + // capturing lamdbda's call operator. + // + + // Since the FunctionScopeInfo stack is representative of the lexical + // nesting of the lambda expressions during initial parsing (and is the best + // place for querying information about captures about lambdas that are + // partially processed) and perhaps during instantiation of function templates + // that contain lambda expressions that need to be transformed BUT not + // necessarily during instantiation of a nested generic lambda's function call + // operator (which might even be instantiated at the end of the TU) - at which + // time the DeclContext tree is mature enough to query capture information + // reliably - we use a two pronged approach to walk through all the lexically + // enclosing lambda expressions: + // + // 1) Climb down the FunctionScopeInfo stack as long as each item represents + // a Lambda (i.e. LambdaScopeInfo) AND each LSI's 'closure-type' is lexically + // enclosed by the call-operator of the LSI below it on the stack (while + // tracking the enclosing DC for step 2 if needed). Note the topmost LSI on + // the stack represents the innermost lambda. + // + // 2) If we run out of enclosing LSI's, check if the enclosing DeclContext + // represents a lambda's call operator. If it does, we must be instantiating + // a generic lambda's call operator (represented by the Current LSI, and + // should be the only scenario where an inconsistency between the LSI and the + // DeclContext should occur), so climb out the DeclContexts if they + // represent lambdas, while querying the corresponding closure types + // regarding capture information. + + // 1) Climb down the function scope info stack. + for (int I = FunctionScopes.size(); + I-- && isa<LambdaScopeInfo>(FunctionScopes[I]) && + (!CurLSI || !CurLSI->Lambda || CurLSI->Lambda->getDeclContext() == + cast<LambdaScopeInfo>(FunctionScopes[I])->CallOperator); + CurDC = getLambdaAwareParentOfDeclContext(CurDC)) { + CurLSI = cast<LambdaScopeInfo>(FunctionScopes[I]); + + if (!CurLSI->isCXXThisCaptured()) + continue; + + auto C = CurLSI->getCXXThisCapture(); + + if (C.isCopyCapture()) { + ClassType.removeLocalCVRQualifiers(Qualifiers::CVRMask); + if (CurLSI->CallOperator->isConst()) + ClassType.addConst(); + return ASTCtx.getPointerType(ClassType); + } + } + + // 2) We've run out of ScopeInfos but check if CurDC is a lambda (which can + // happen during instantiation of its nested generic lambda call operator) + if (isLambdaCallOperator(CurDC)) { + assert(CurLSI && "While computing 'this' capture-type for a generic " + "lambda, we must have a corresponding LambdaScopeInfo"); + assert(isGenericLambdaCallOperatorSpecialization(CurLSI->CallOperator) && + "While computing 'this' capture-type for a generic lambda, when we " + "run out of enclosing LSI's, yet the enclosing DC is a " + "lambda-call-operator we must be (i.e. Current LSI) in a generic " + "lambda call oeprator"); + assert(CurDC == getLambdaAwareParentOfDeclContext(CurLSI->CallOperator)); + + auto IsThisCaptured = + [](CXXRecordDecl *Closure, bool &IsByCopy, bool &IsConst) { + IsConst = false; + IsByCopy = false; + for (auto &&C : Closure->captures()) { + if (C.capturesThis()) { + if (C.getCaptureKind() == LCK_StarThis) + IsByCopy = true; + if (Closure->getLambdaCallOperator()->isConst()) + IsConst = true; + return true; + } + } + return false; + }; + + bool IsByCopyCapture = false; + bool IsConstCapture = false; + CXXRecordDecl *Closure = cast<CXXRecordDecl>(CurDC->getParent()); + while (Closure && + IsThisCaptured(Closure, IsByCopyCapture, IsConstCapture)) { + if (IsByCopyCapture) { + ClassType.removeLocalCVRQualifiers(Qualifiers::CVRMask); + if (IsConstCapture) + ClassType.addConst(); + return ASTCtx.getPointerType(ClassType); + } + Closure = isLambdaCallOperator(Closure->getParent()) + ? cast<CXXRecordDecl>(Closure->getParent()->getParent()) + : nullptr; + } + } + return ASTCtx.getPointerType(ClassType); +} + +QualType Sema::getCurrentThisType() { + DeclContext *DC = getFunctionLevelDeclContext(); + QualType ThisTy = CXXThisTypeOverride; + + if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) { + if (method && method->isInstance()) + ThisTy = method->getThisType(); + } + + if (ThisTy.isNull() && isLambdaCallOperator(CurContext) && + inTemplateInstantiation()) { + + assert(isa<CXXRecordDecl>(DC) && + "Trying to get 'this' type from static method?"); + + // This is a lambda call operator that is being instantiated as a default + // initializer. DC must point to the enclosing class type, so we can recover + // the 'this' type from it. + + QualType ClassTy = Context.getTypeDeclType(cast<CXXRecordDecl>(DC)); + // There are no cv-qualifiers for 'this' within default initializers, + // per [expr.prim.general]p4. + ThisTy = Context.getPointerType(ClassTy); + } + + // If we are within a lambda's call operator, the cv-qualifiers of 'this' + // might need to be adjusted if the lambda or any of its enclosing lambda's + // captures '*this' by copy. + if (!ThisTy.isNull() && isLambdaCallOperator(CurContext)) + return adjustCVQualifiersForCXXThisWithinLambda(FunctionScopes, ThisTy, + CurContext, Context); + return ThisTy; +} + +Sema::CXXThisScopeRAII::CXXThisScopeRAII(Sema &S, + Decl *ContextDecl, + Qualifiers CXXThisTypeQuals, + bool Enabled) + : S(S), OldCXXThisTypeOverride(S.CXXThisTypeOverride), Enabled(false) +{ + if (!Enabled || !ContextDecl) + return; + + CXXRecordDecl *Record = nullptr; + if (ClassTemplateDecl *Template = dyn_cast<ClassTemplateDecl>(ContextDecl)) + Record = Template->getTemplatedDecl(); + else + Record = cast<CXXRecordDecl>(ContextDecl); + + QualType T = S.Context.getRecordType(Record); + T = S.getASTContext().getQualifiedType(T, CXXThisTypeQuals); + + S.CXXThisTypeOverride = S.Context.getPointerType(T); + + this->Enabled = true; +} + + +Sema::CXXThisScopeRAII::~CXXThisScopeRAII() { + if (Enabled) { + S.CXXThisTypeOverride = OldCXXThisTypeOverride; + } +} + +bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit, + bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt, + const bool ByCopy) { + // We don't need to capture this in an unevaluated context. + if (isUnevaluatedContext() && !Explicit) + return true; + + assert((!ByCopy || Explicit) && "cannot implicitly capture *this by value"); + + const int MaxFunctionScopesIndex = FunctionScopeIndexToStopAt + ? *FunctionScopeIndexToStopAt + : FunctionScopes.size() - 1; + + // Check that we can capture the *enclosing object* (referred to by '*this') + // by the capturing-entity/closure (lambda/block/etc) at + // MaxFunctionScopesIndex-deep on the FunctionScopes stack. + + // Note: The *enclosing object* can only be captured by-value by a + // closure that is a lambda, using the explicit notation: + // [*this] { ... }. + // Every other capture of the *enclosing object* results in its by-reference + // capture. + + // For a closure 'L' (at MaxFunctionScopesIndex in the FunctionScopes + // stack), we can capture the *enclosing object* only if: + // - 'L' has an explicit byref or byval capture of the *enclosing object* + // - or, 'L' has an implicit capture. + // AND + // -- there is no enclosing closure + // -- or, there is some enclosing closure 'E' that has already captured the + // *enclosing object*, and every intervening closure (if any) between 'E' + // and 'L' can implicitly capture the *enclosing object*. + // -- or, every enclosing closure can implicitly capture the + // *enclosing object* + + + unsigned NumCapturingClosures = 0; + for (int idx = MaxFunctionScopesIndex; idx >= 0; idx--) { + if (CapturingScopeInfo *CSI = + dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) { + if (CSI->CXXThisCaptureIndex != 0) { + // 'this' is already being captured; there isn't anything more to do. + CSI->Captures[CSI->CXXThisCaptureIndex - 1].markUsed(BuildAndDiagnose); + break; + } + LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI); + if (LSI && isGenericLambdaCallOperatorSpecialization(LSI->CallOperator)) { + // This context can't implicitly capture 'this'; fail out. + if (BuildAndDiagnose) + Diag(Loc, diag::err_this_capture) + << (Explicit && idx == MaxFunctionScopesIndex); + return true; + } + if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref || + CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval || + CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block || + CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_CapturedRegion || + (Explicit && idx == MaxFunctionScopesIndex)) { + // Regarding (Explicit && idx == MaxFunctionScopesIndex): only the first + // iteration through can be an explicit capture, all enclosing closures, + // if any, must perform implicit captures. + + // This closure can capture 'this'; continue looking upwards. + NumCapturingClosures++; + continue; + } + // This context can't implicitly capture 'this'; fail out. + if (BuildAndDiagnose) + Diag(Loc, diag::err_this_capture) + << (Explicit && idx == MaxFunctionScopesIndex); + return true; + } + break; + } + if (!BuildAndDiagnose) return false; + + // If we got here, then the closure at MaxFunctionScopesIndex on the + // FunctionScopes stack, can capture the *enclosing object*, so capture it + // (including implicit by-reference captures in any enclosing closures). + + // In the loop below, respect the ByCopy flag only for the closure requesting + // the capture (i.e. first iteration through the loop below). Ignore it for + // all enclosing closure's up to NumCapturingClosures (since they must be + // implicitly capturing the *enclosing object* by reference (see loop + // above)). + assert((!ByCopy || + dyn_cast<LambdaScopeInfo>(FunctionScopes[MaxFunctionScopesIndex])) && + "Only a lambda can capture the enclosing object (referred to by " + "*this) by copy"); + QualType ThisTy = getCurrentThisType(); + for (int idx = MaxFunctionScopesIndex; NumCapturingClosures; + --idx, --NumCapturingClosures) { + CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]); + + // The type of the corresponding data member (not a 'this' pointer if 'by + // copy'). + QualType CaptureType = ThisTy; + if (ByCopy) { + // If we are capturing the object referred to by '*this' by copy, ignore + // any cv qualifiers inherited from the type of the member function for + // the type of the closure-type's corresponding data member and any use + // of 'this'. + CaptureType = ThisTy->getPointeeType(); + CaptureType.removeLocalCVRQualifiers(Qualifiers::CVRMask); + } + + bool isNested = NumCapturingClosures > 1; + CSI->addThisCapture(isNested, Loc, CaptureType, ByCopy); + } + return false; +} + +ExprResult Sema::ActOnCXXThis(SourceLocation Loc) { + /// C++ 9.3.2: In the body of a non-static member function, the keyword this + /// is a non-lvalue expression whose value is the address of the object for + /// which the function is called. + + QualType ThisTy = getCurrentThisType(); + if (ThisTy.isNull()) + return Diag(Loc, diag::err_invalid_this_use); + return BuildCXXThisExpr(Loc, ThisTy, /*IsImplicit=*/false); +} + +Expr *Sema::BuildCXXThisExpr(SourceLocation Loc, QualType Type, + bool IsImplicit) { + auto *This = new (Context) CXXThisExpr(Loc, Type, IsImplicit); + MarkThisReferenced(This); + return This; +} + +void Sema::MarkThisReferenced(CXXThisExpr *This) { + CheckCXXThisCapture(This->getExprLoc()); +} + +bool Sema::isThisOutsideMemberFunctionBody(QualType BaseType) { + // If we're outside the body of a member function, then we'll have a specified + // type for 'this'. + if (CXXThisTypeOverride.isNull()) + return false; + + // Determine whether we're looking into a class that's currently being + // defined. + CXXRecordDecl *Class = BaseType->getAsCXXRecordDecl(); + return Class && Class->isBeingDefined(); +} + +/// Parse construction of a specified type. +/// Can be interpreted either as function-style casting ("int(x)") +/// or class type construction ("ClassType(x,y,z)") +/// or creation of a value-initialized type ("int()"). +ExprResult +Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep, + SourceLocation LParenOrBraceLoc, + MultiExprArg exprs, + SourceLocation RParenOrBraceLoc, + bool ListInitialization) { + if (!TypeRep) + return ExprError(); + + TypeSourceInfo *TInfo; + QualType Ty = GetTypeFromParser(TypeRep, &TInfo); + if (!TInfo) + TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation()); + + auto Result = BuildCXXTypeConstructExpr(TInfo, LParenOrBraceLoc, exprs, + RParenOrBraceLoc, ListInitialization); + // Avoid creating a non-type-dependent expression that contains typos. + // Non-type-dependent expressions are liable to be discarded without + // checking for embedded typos. + if (!Result.isInvalid() && Result.get()->isInstantiationDependent() && + !Result.get()->isTypeDependent()) + Result = CorrectDelayedTyposInExpr(Result.get()); + return Result; +} + +ExprResult +Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo, + SourceLocation LParenOrBraceLoc, + MultiExprArg Exprs, + SourceLocation RParenOrBraceLoc, + bool ListInitialization) { + QualType Ty = TInfo->getType(); + SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc(); + + if (Ty->isDependentType() || CallExpr::hasAnyTypeDependentArguments(Exprs)) { + // FIXME: CXXUnresolvedConstructExpr does not model list-initialization + // directly. We work around this by dropping the locations of the braces. + SourceRange Locs = ListInitialization + ? SourceRange() + : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc); + return CXXUnresolvedConstructExpr::Create(Context, TInfo, Locs.getBegin(), + Exprs, Locs.getEnd()); + } + + assert((!ListInitialization || + (Exprs.size() == 1 && isa<InitListExpr>(Exprs[0]))) && + "List initialization must have initializer list as expression."); + SourceRange FullRange = SourceRange(TyBeginLoc, RParenOrBraceLoc); + + InitializedEntity Entity = InitializedEntity::InitializeTemporary(TInfo); + InitializationKind Kind = + Exprs.size() + ? ListInitialization + ? InitializationKind::CreateDirectList( + TyBeginLoc, LParenOrBraceLoc, RParenOrBraceLoc) + : InitializationKind::CreateDirect(TyBeginLoc, LParenOrBraceLoc, + RParenOrBraceLoc) + : InitializationKind::CreateValue(TyBeginLoc, LParenOrBraceLoc, + RParenOrBraceLoc); + + // C++1z [expr.type.conv]p1: + // If the type is a placeholder for a deduced class type, [...perform class + // template argument deduction...] + DeducedType *Deduced = Ty->getContainedDeducedType(); + if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) { + Ty = DeduceTemplateSpecializationFromInitializer(TInfo, Entity, + Kind, Exprs); + if (Ty.isNull()) + return ExprError(); + Entity = InitializedEntity::InitializeTemporary(TInfo, Ty); + } + + // C++ [expr.type.conv]p1: + // If the expression list is a parenthesized single expression, the type + // conversion expression is equivalent (in definedness, and if defined in + // meaning) to the corresponding cast expression. + if (Exprs.size() == 1 && !ListInitialization && + !isa<InitListExpr>(Exprs[0])) { + Expr *Arg = Exprs[0]; + return BuildCXXFunctionalCastExpr(TInfo, Ty, LParenOrBraceLoc, Arg, + RParenOrBraceLoc); + } + + // For an expression of the form T(), T shall not be an array type. + QualType ElemTy = Ty; + if (Ty->isArrayType()) { + if (!ListInitialization) + return ExprError(Diag(TyBeginLoc, diag::err_value_init_for_array_type) + << FullRange); + ElemTy = Context.getBaseElementType(Ty); + } + + // There doesn't seem to be an explicit rule against this but sanity demands + // we only construct objects with object types. + if (Ty->isFunctionType()) + return ExprError(Diag(TyBeginLoc, diag::err_init_for_function_type) + << Ty << FullRange); + + // C++17 [expr.type.conv]p2: + // If the type is cv void and the initializer is (), the expression is a + // prvalue of the specified type that performs no initialization. + if (!Ty->isVoidType() && + RequireCompleteType(TyBeginLoc, ElemTy, + diag::err_invalid_incomplete_type_use, FullRange)) + return ExprError(); + + // Otherwise, the expression is a prvalue of the specified type whose + // result object is direct-initialized (11.6) with the initializer. + InitializationSequence InitSeq(*this, Entity, Kind, Exprs); + ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs); + + if (Result.isInvalid()) + return Result; + + Expr *Inner = Result.get(); + if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null<CXXBindTemporaryExpr>(Inner)) + Inner = BTE->getSubExpr(); + if (!isa<CXXTemporaryObjectExpr>(Inner) && + !isa<CXXScalarValueInitExpr>(Inner)) { + // If we created a CXXTemporaryObjectExpr, that node also represents the + // functional cast. Otherwise, create an explicit cast to represent + // the syntactic form of a functional-style cast that was used here. + // + // FIXME: Creating a CXXFunctionalCastExpr around a CXXConstructExpr + // would give a more consistent AST representation than using a + // CXXTemporaryObjectExpr. It's also weird that the functional cast + // is sometimes handled by initialization and sometimes not. + QualType ResultType = Result.get()->getType(); + SourceRange Locs = ListInitialization + ? SourceRange() + : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc); + Result = CXXFunctionalCastExpr::Create( + Context, ResultType, Expr::getValueKindForType(Ty), TInfo, CK_NoOp, + Result.get(), /*Path=*/nullptr, Locs.getBegin(), Locs.getEnd()); + } + + return Result; +} + +bool Sema::isUsualDeallocationFunction(const CXXMethodDecl *Method) { + // [CUDA] Ignore this function, if we can't call it. + const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext); + if (getLangOpts().CUDA && + IdentifyCUDAPreference(Caller, Method) <= CFP_WrongSide) + return false; + + SmallVector<const FunctionDecl*, 4> PreventedBy; + bool Result = Method->isUsualDeallocationFunction(PreventedBy); + + if (Result || !getLangOpts().CUDA || PreventedBy.empty()) + return Result; + + // In case of CUDA, return true if none of the 1-argument deallocator + // functions are actually callable. + return llvm::none_of(PreventedBy, [&](const FunctionDecl *FD) { + assert(FD->getNumParams() == 1 && + "Only single-operand functions should be in PreventedBy"); + return IdentifyCUDAPreference(Caller, FD) >= CFP_HostDevice; + }); +} + +/// Determine whether the given function is a non-placement +/// deallocation function. +static bool isNonPlacementDeallocationFunction(Sema &S, FunctionDecl *FD) { + if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) + return S.isUsualDeallocationFunction(Method); + + if (FD->getOverloadedOperator() != OO_Delete && + FD->getOverloadedOperator() != OO_Array_Delete) + return false; + + unsigned UsualParams = 1; + + if (S.getLangOpts().SizedDeallocation && UsualParams < FD->getNumParams() && + S.Context.hasSameUnqualifiedType( + FD->getParamDecl(UsualParams)->getType(), + S.Context.getSizeType())) + ++UsualParams; + + if (S.getLangOpts().AlignedAllocation && UsualParams < FD->getNumParams() && + S.Context.hasSameUnqualifiedType( + FD->getParamDecl(UsualParams)->getType(), + S.Context.getTypeDeclType(S.getStdAlignValT()))) + ++UsualParams; + + return UsualParams == FD->getNumParams(); +} + +namespace { + struct UsualDeallocFnInfo { + UsualDeallocFnInfo() : Found(), FD(nullptr) {} + UsualDeallocFnInfo(Sema &S, DeclAccessPair Found) + : Found(Found), FD(dyn_cast<FunctionDecl>(Found->getUnderlyingDecl())), + Destroying(false), HasSizeT(false), HasAlignValT(false), + CUDAPref(Sema::CFP_Native) { + // A function template declaration is never a usual deallocation function. + if (!FD) + return; + unsigned NumBaseParams = 1; + if (FD->isDestroyingOperatorDelete()) { + Destroying = true; + ++NumBaseParams; + } + + if (NumBaseParams < FD->getNumParams() && + S.Context.hasSameUnqualifiedType( + FD->getParamDecl(NumBaseParams)->getType(), + S.Context.getSizeType())) { + ++NumBaseParams; + HasSizeT = true; + } + + if (NumBaseParams < FD->getNumParams() && + FD->getParamDecl(NumBaseParams)->getType()->isAlignValT()) { + ++NumBaseParams; + HasAlignValT = true; + } + + // In CUDA, determine how much we'd like / dislike to call this. + if (S.getLangOpts().CUDA) + if (auto *Caller = dyn_cast<FunctionDecl>(S.CurContext)) + CUDAPref = S.IdentifyCUDAPreference(Caller, FD); + } + + explicit operator bool() const { return FD; } + + bool isBetterThan(const UsualDeallocFnInfo &Other, bool WantSize, + bool WantAlign) const { + // C++ P0722: + // A destroying operator delete is preferred over a non-destroying + // operator delete. + if (Destroying != Other.Destroying) + return Destroying; + + // C++17 [expr.delete]p10: + // If the type has new-extended alignment, a function with a parameter + // of type std::align_val_t is preferred; otherwise a function without + // such a parameter is preferred + if (HasAlignValT != Other.HasAlignValT) + return HasAlignValT == WantAlign; + + if (HasSizeT != Other.HasSizeT) + return HasSizeT == WantSize; + + // Use CUDA call preference as a tiebreaker. + return CUDAPref > Other.CUDAPref; + } + + DeclAccessPair Found; + FunctionDecl *FD; + bool Destroying, HasSizeT, HasAlignValT; + Sema::CUDAFunctionPreference CUDAPref; + }; +} + +/// Determine whether a type has new-extended alignment. This may be called when +/// the type is incomplete (for a delete-expression with an incomplete pointee +/// type), in which case it will conservatively return false if the alignment is +/// not known. +static bool hasNewExtendedAlignment(Sema &S, QualType AllocType) { + return S.getLangOpts().AlignedAllocation && + S.getASTContext().getTypeAlignIfKnown(AllocType) > + S.getASTContext().getTargetInfo().getNewAlign(); +} + +/// Select the correct "usual" deallocation function to use from a selection of +/// deallocation functions (either global or class-scope). +static UsualDeallocFnInfo resolveDeallocationOverload( + Sema &S, LookupResult &R, bool WantSize, bool WantAlign, + llvm::SmallVectorImpl<UsualDeallocFnInfo> *BestFns = nullptr) { + UsualDeallocFnInfo Best; + + for (auto I = R.begin(), E = R.end(); I != E; ++I) { + UsualDeallocFnInfo Info(S, I.getPair()); + if (!Info || !isNonPlacementDeallocationFunction(S, Info.FD) || + Info.CUDAPref == Sema::CFP_Never) + continue; + + if (!Best) { + Best = Info; + if (BestFns) + BestFns->push_back(Info); + continue; + } + + if (Best.isBetterThan(Info, WantSize, WantAlign)) + continue; + + // If more than one preferred function is found, all non-preferred + // functions are eliminated from further consideration. + if (BestFns && Info.isBetterThan(Best, WantSize, WantAlign)) + BestFns->clear(); + + Best = Info; + if (BestFns) + BestFns->push_back(Info); + } + + return Best; +} + +/// Determine whether a given type is a class for which 'delete[]' would call +/// a member 'operator delete[]' with a 'size_t' parameter. This implies that +/// we need to store the array size (even if the type is +/// trivially-destructible). +static bool doesUsualArrayDeleteWantSize(Sema &S, SourceLocation loc, + QualType allocType) { + const RecordType *record = + allocType->getBaseElementTypeUnsafe()->getAs<RecordType>(); + if (!record) return false; + + // Try to find an operator delete[] in class scope. + + DeclarationName deleteName = + S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete); + LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName); + S.LookupQualifiedName(ops, record->getDecl()); + + // We're just doing this for information. + ops.suppressDiagnostics(); + + // Very likely: there's no operator delete[]. + if (ops.empty()) return false; + + // If it's ambiguous, it should be illegal to call operator delete[] + // on this thing, so it doesn't matter if we allocate extra space or not. + if (ops.isAmbiguous()) return false; + + // C++17 [expr.delete]p10: + // If the deallocation functions have class scope, the one without a + // parameter of type std::size_t is selected. + auto Best = resolveDeallocationOverload( + S, ops, /*WantSize*/false, + /*WantAlign*/hasNewExtendedAlignment(S, allocType)); + return Best && Best.HasSizeT; +} + +/// Parsed a C++ 'new' expression (C++ 5.3.4). +/// +/// E.g.: +/// @code new (memory) int[size][4] @endcode +/// or +/// @code ::new Foo(23, "hello") @endcode +/// +/// \param StartLoc The first location of the expression. +/// \param UseGlobal True if 'new' was prefixed with '::'. +/// \param PlacementLParen Opening paren of the placement arguments. +/// \param PlacementArgs Placement new arguments. +/// \param PlacementRParen Closing paren of the placement arguments. +/// \param TypeIdParens If the type is in parens, the source range. +/// \param D The type to be allocated, as well as array dimensions. +/// \param Initializer The initializing expression or initializer-list, or null +/// if there is none. +ExprResult +Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal, + SourceLocation PlacementLParen, MultiExprArg PlacementArgs, + SourceLocation PlacementRParen, SourceRange TypeIdParens, + Declarator &D, Expr *Initializer) { + Optional<Expr *> ArraySize; + // If the specified type is an array, unwrap it and save the expression. + if (D.getNumTypeObjects() > 0 && + D.getTypeObject(0).Kind == DeclaratorChunk::Array) { + DeclaratorChunk &Chunk = D.getTypeObject(0); + if (D.getDeclSpec().hasAutoTypeSpec()) + return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto) + << D.getSourceRange()); + if (Chunk.Arr.hasStatic) + return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new) + << D.getSourceRange()); + if (!Chunk.Arr.NumElts && !Initializer) + return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size) + << D.getSourceRange()); + + ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts); + D.DropFirstTypeObject(); + } + + // Every dimension shall be of constant size. + if (ArraySize) { + for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) { + if (D.getTypeObject(I).Kind != DeclaratorChunk::Array) + break; + + DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr; + if (Expr *NumElts = (Expr *)Array.NumElts) { + if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) { + if (getLangOpts().CPlusPlus14) { + // C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator + // shall be a converted constant expression (5.19) of type std::size_t + // and shall evaluate to a strictly positive value. + unsigned IntWidth = Context.getTargetInfo().getIntWidth(); + assert(IntWidth && "Builtin type of size 0?"); + llvm::APSInt Value(IntWidth); + Array.NumElts + = CheckConvertedConstantExpression(NumElts, Context.getSizeType(), Value, + CCEK_NewExpr) + .get(); + } else { + Array.NumElts + = VerifyIntegerConstantExpression(NumElts, nullptr, + diag::err_new_array_nonconst) + .get(); + } + if (!Array.NumElts) + return ExprError(); + } + } + } + } + + TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr); + QualType AllocType = TInfo->getType(); + if (D.isInvalidType()) + return ExprError(); + + SourceRange DirectInitRange; + if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) + DirectInitRange = List->getSourceRange(); + + return BuildCXXNew(SourceRange(StartLoc, D.getEndLoc()), UseGlobal, + PlacementLParen, PlacementArgs, PlacementRParen, + TypeIdParens, AllocType, TInfo, ArraySize, DirectInitRange, + Initializer); +} + +static bool isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style, + Expr *Init) { + if (!Init) + return true; + if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init)) + return PLE->getNumExprs() == 0; + if (isa<ImplicitValueInitExpr>(Init)) + return true; + else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) + return !CCE->isListInitialization() && + CCE->getConstructor()->isDefaultConstructor(); + else if (Style == CXXNewExpr::ListInit) { + assert(isa<InitListExpr>(Init) && + "Shouldn't create list CXXConstructExprs for arrays."); + return true; + } + return false; +} + +bool +Sema::isUnavailableAlignedAllocationFunction(const FunctionDecl &FD) const { + if (!getLangOpts().AlignedAllocationUnavailable) + return false; + if (FD.isDefined()) + return false; + bool IsAligned = false; + if (FD.isReplaceableGlobalAllocationFunction(&IsAligned) && IsAligned) + return true; + return false; +} + +// Emit a diagnostic if an aligned allocation/deallocation function that is not +// implemented in the standard library is selected. +void Sema::diagnoseUnavailableAlignedAllocation(const FunctionDecl &FD, + SourceLocation Loc) { + if (isUnavailableAlignedAllocationFunction(FD)) { + const llvm::Triple &T = getASTContext().getTargetInfo().getTriple(); + StringRef OSName = AvailabilityAttr::getPlatformNameSourceSpelling( + getASTContext().getTargetInfo().getPlatformName()); + + OverloadedOperatorKind Kind = FD.getDeclName().getCXXOverloadedOperator(); + bool IsDelete = Kind == OO_Delete || Kind == OO_Array_Delete; + Diag(Loc, diag::err_aligned_allocation_unavailable) + << IsDelete << FD.getType().getAsString() << OSName + << alignedAllocMinVersion(T.getOS()).getAsString(); + Diag(Loc, diag::note_silence_aligned_allocation_unavailable); + } +} + +ExprResult +Sema::BuildCXXNew(SourceRange Range, bool UseGlobal, + SourceLocation PlacementLParen, + MultiExprArg PlacementArgs, + SourceLocation PlacementRParen, + SourceRange TypeIdParens, + QualType AllocType, + TypeSourceInfo *AllocTypeInfo, + Optional<Expr *> ArraySize, + SourceRange DirectInitRange, + Expr *Initializer) { + SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange(); + SourceLocation StartLoc = Range.getBegin(); + + CXXNewExpr::InitializationStyle initStyle; + if (DirectInitRange.isValid()) { + assert(Initializer && "Have parens but no initializer."); + initStyle = CXXNewExpr::CallInit; + } else if (Initializer && isa<InitListExpr>(Initializer)) + initStyle = CXXNewExpr::ListInit; + else { + assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) || + isa<CXXConstructExpr>(Initializer)) && + "Initializer expression that cannot have been implicitly created."); + initStyle = CXXNewExpr::NoInit; + } + + Expr **Inits = &Initializer; + unsigned NumInits = Initializer ? 1 : 0; + if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) { + assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init"); + Inits = List->getExprs(); + NumInits = List->getNumExprs(); + } + + // C++11 [expr.new]p15: + // A new-expression that creates an object of type T initializes that + // object as follows: + InitializationKind Kind + // - If the new-initializer is omitted, the object is default- + // initialized (8.5); if no initialization is performed, + // the object has indeterminate value + = initStyle == CXXNewExpr::NoInit + ? InitializationKind::CreateDefault(TypeRange.getBegin()) + // - Otherwise, the new-initializer is interpreted according to + // the + // initialization rules of 8.5 for direct-initialization. + : initStyle == CXXNewExpr::ListInit + ? InitializationKind::CreateDirectList( + TypeRange.getBegin(), Initializer->getBeginLoc(), + Initializer->getEndLoc()) + : InitializationKind::CreateDirect(TypeRange.getBegin(), + DirectInitRange.getBegin(), + DirectInitRange.getEnd()); + + // C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for. + auto *Deduced = AllocType->getContainedDeducedType(); + if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) { + if (ArraySize) + return ExprError( + Diag(ArraySize ? (*ArraySize)->getExprLoc() : TypeRange.getBegin(), + diag::err_deduced_class_template_compound_type) + << /*array*/ 2 + << (ArraySize ? (*ArraySize)->getSourceRange() : TypeRange)); + + InitializedEntity Entity + = InitializedEntity::InitializeNew(StartLoc, AllocType); + AllocType = DeduceTemplateSpecializationFromInitializer( + AllocTypeInfo, Entity, Kind, MultiExprArg(Inits, NumInits)); + if (AllocType.isNull()) + return ExprError(); + } else if (Deduced) { + bool Braced = (initStyle == CXXNewExpr::ListInit); + if (NumInits == 1) { + if (auto p = dyn_cast_or_null<InitListExpr>(Inits[0])) { + Inits = p->getInits(); + NumInits = p->getNumInits(); + Braced = true; + } + } + + if (initStyle == CXXNewExpr::NoInit || NumInits == 0) + return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg) + << AllocType << TypeRange); + if (NumInits > 1) { + Expr *FirstBad = Inits[1]; + return ExprError(Diag(FirstBad->getBeginLoc(), + diag::err_auto_new_ctor_multiple_expressions) + << AllocType << TypeRange); + } + if (Braced && !getLangOpts().CPlusPlus17) + Diag(Initializer->getBeginLoc(), diag::ext_auto_new_list_init) + << AllocType << TypeRange; + Expr *Deduce = Inits[0]; + QualType DeducedType; + if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == DAR_Failed) + return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure) + << AllocType << Deduce->getType() + << TypeRange << Deduce->getSourceRange()); + if (DeducedType.isNull()) + return ExprError(); + AllocType = DeducedType; + } + + // Per C++0x [expr.new]p5, the type being constructed may be a + // typedef of an array type. + if (!ArraySize) { + if (const ConstantArrayType *Array + = Context.getAsConstantArrayType(AllocType)) { + ArraySize = IntegerLiteral::Create(Context, Array->getSize(), + Context.getSizeType(), + TypeRange.getEnd()); + AllocType = Array->getElementType(); + } + } + + if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange)) + return ExprError(); + + // In ARC, infer 'retaining' for the allocated + if (getLangOpts().ObjCAutoRefCount && + AllocType.getObjCLifetime() == Qualifiers::OCL_None && + AllocType->isObjCLifetimeType()) { + AllocType = Context.getLifetimeQualifiedType(AllocType, + AllocType->getObjCARCImplicitLifetime()); + } + + QualType ResultType = Context.getPointerType(AllocType); + + if (ArraySize && *ArraySize && + (*ArraySize)->getType()->isNonOverloadPlaceholderType()) { + ExprResult result = CheckPlaceholderExpr(*ArraySize); + if (result.isInvalid()) return ExprError(); + ArraySize = result.get(); + } + // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have + // integral or enumeration type with a non-negative value." + // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped + // enumeration type, or a class type for which a single non-explicit + // conversion function to integral or unscoped enumeration type exists. + // C++1y [expr.new]p6: The expression [...] is implicitly converted to + // std::size_t. + llvm::Optional<uint64_t> KnownArraySize; + if (ArraySize && *ArraySize && !(*ArraySize)->isTypeDependent()) { + ExprResult ConvertedSize; + if (getLangOpts().CPlusPlus14) { + assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?"); + + ConvertedSize = PerformImplicitConversion(*ArraySize, Context.getSizeType(), + AA_Converting); + + if (!ConvertedSize.isInvalid() && + (*ArraySize)->getType()->getAs<RecordType>()) + // Diagnose the compatibility of this conversion. + Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion) + << (*ArraySize)->getType() << 0 << "'size_t'"; + } else { + class SizeConvertDiagnoser : public ICEConvertDiagnoser { + protected: + Expr *ArraySize; + + public: + SizeConvertDiagnoser(Expr *ArraySize) + : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false), + ArraySize(ArraySize) {} + + SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc, + QualType T) override { + return S.Diag(Loc, diag::err_array_size_not_integral) + << S.getLangOpts().CPlusPlus11 << T; + } + + SemaDiagnosticBuilder diagnoseIncomplete( + Sema &S, SourceLocation Loc, QualType T) override { + return S.Diag(Loc, diag::err_array_size_incomplete_type) + << T << ArraySize->getSourceRange(); + } + + SemaDiagnosticBuilder diagnoseExplicitConv( + Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { + return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy; + } + + SemaDiagnosticBuilder noteExplicitConv( + Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { + return S.Diag(Conv->getLocation(), diag::note_array_size_conversion) + << ConvTy->isEnumeralType() << ConvTy; + } + + SemaDiagnosticBuilder diagnoseAmbiguous( + Sema &S, SourceLocation Loc, QualType T) override { + return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T; + } + + SemaDiagnosticBuilder noteAmbiguous( + Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { + return S.Diag(Conv->getLocation(), diag::note_array_size_conversion) + << ConvTy->isEnumeralType() << ConvTy; + } + + SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc, + QualType T, + QualType ConvTy) override { + return S.Diag(Loc, + S.getLangOpts().CPlusPlus11 + ? diag::warn_cxx98_compat_array_size_conversion + : diag::ext_array_size_conversion) + << T << ConvTy->isEnumeralType() << ConvTy; + } + } SizeDiagnoser(*ArraySize); + + ConvertedSize = PerformContextualImplicitConversion(StartLoc, *ArraySize, + SizeDiagnoser); + } + if (ConvertedSize.isInvalid()) + return ExprError(); + + ArraySize = ConvertedSize.get(); + QualType SizeType = (*ArraySize)->getType(); + + if (!SizeType->isIntegralOrUnscopedEnumerationType()) + return ExprError(); + + // C++98 [expr.new]p7: + // The expression in a direct-new-declarator shall have integral type + // with a non-negative value. + // + // Let's see if this is a constant < 0. If so, we reject it out of hand, + // per CWG1464. Otherwise, if it's not a constant, we must have an + // unparenthesized array type. + if (!(*ArraySize)->isValueDependent()) { + llvm::APSInt Value; + // We've already performed any required implicit conversion to integer or + // unscoped enumeration type. + // FIXME: Per CWG1464, we are required to check the value prior to + // converting to size_t. This will never find a negative array size in + // C++14 onwards, because Value is always unsigned here! + if ((*ArraySize)->isIntegerConstantExpr(Value, Context)) { + if (Value.isSigned() && Value.isNegative()) { + return ExprError(Diag((*ArraySize)->getBeginLoc(), + diag::err_typecheck_negative_array_size) + << (*ArraySize)->getSourceRange()); + } + + if (!AllocType->isDependentType()) { + unsigned ActiveSizeBits = + ConstantArrayType::getNumAddressingBits(Context, AllocType, Value); + if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) + return ExprError( + Diag((*ArraySize)->getBeginLoc(), diag::err_array_too_large) + << Value.toString(10) << (*ArraySize)->getSourceRange()); + } + + KnownArraySize = Value.getZExtValue(); + } else if (TypeIdParens.isValid()) { + // Can't have dynamic array size when the type-id is in parentheses. + Diag((*ArraySize)->getBeginLoc(), diag::ext_new_paren_array_nonconst) + << (*ArraySize)->getSourceRange() + << FixItHint::CreateRemoval(TypeIdParens.getBegin()) + << FixItHint::CreateRemoval(TypeIdParens.getEnd()); + + TypeIdParens = SourceRange(); + } + } + + // Note that we do *not* convert the argument in any way. It can + // be signed, larger than size_t, whatever. + } + + FunctionDecl *OperatorNew = nullptr; + FunctionDecl *OperatorDelete = nullptr; + unsigned Alignment = + AllocType->isDependentType() ? 0 : Context.getTypeAlign(AllocType); + unsigned NewAlignment = Context.getTargetInfo().getNewAlign(); + bool PassAlignment = getLangOpts().AlignedAllocation && + Alignment > NewAlignment; + + AllocationFunctionScope Scope = UseGlobal ? AFS_Global : AFS_Both; + if (!AllocType->isDependentType() && + !Expr::hasAnyTypeDependentArguments(PlacementArgs) && + FindAllocationFunctions( + StartLoc, SourceRange(PlacementLParen, PlacementRParen), Scope, Scope, + AllocType, ArraySize.hasValue(), PassAlignment, PlacementArgs, + OperatorNew, OperatorDelete)) + return ExprError(); + + // If this is an array allocation, compute whether the usual array + // deallocation function for the type has a size_t parameter. + bool UsualArrayDeleteWantsSize = false; + if (ArraySize && !AllocType->isDependentType()) + UsualArrayDeleteWantsSize = + doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType); + + SmallVector<Expr *, 8> AllPlaceArgs; + if (OperatorNew) { + const FunctionProtoType *Proto = + OperatorNew->getType()->getAs<FunctionProtoType>(); + VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction + : VariadicDoesNotApply; + + // We've already converted the placement args, just fill in any default + // arguments. Skip the first parameter because we don't have a corresponding + // argument. Skip the second parameter too if we're passing in the + // alignment; we've already filled it in. + if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto, + PassAlignment ? 2 : 1, PlacementArgs, + AllPlaceArgs, CallType)) + return ExprError(); + + if (!AllPlaceArgs.empty()) + PlacementArgs = AllPlaceArgs; + + // FIXME: This is wrong: PlacementArgs misses out the first (size) argument. + DiagnoseSentinelCalls(OperatorNew, PlacementLParen, PlacementArgs); + + // FIXME: Missing call to CheckFunctionCall or equivalent + + // Warn if the type is over-aligned and is being allocated by (unaligned) + // global operator new. + if (PlacementArgs.empty() && !PassAlignment && + (OperatorNew->isImplicit() || + (OperatorNew->getBeginLoc().isValid() && + getSourceManager().isInSystemHeader(OperatorNew->getBeginLoc())))) { + if (Alignment > NewAlignment) + Diag(StartLoc, diag::warn_overaligned_type) + << AllocType + << unsigned(Alignment / Context.getCharWidth()) + << unsigned(NewAlignment / Context.getCharWidth()); + } + } + + // Array 'new' can't have any initializers except empty parentheses. + // Initializer lists are also allowed, in C++11. Rely on the parser for the + // dialect distinction. + if (ArraySize && !isLegalArrayNewInitializer(initStyle, Initializer)) { + SourceRange InitRange(Inits[0]->getBeginLoc(), + Inits[NumInits - 1]->getEndLoc()); + Diag(StartLoc, diag::err_new_array_init_args) << InitRange; + return ExprError(); + } + + // If we can perform the initialization, and we've not already done so, + // do it now. + if (!AllocType->isDependentType() && + !Expr::hasAnyTypeDependentArguments( + llvm::makeArrayRef(Inits, NumInits))) { + // The type we initialize is the complete type, including the array bound. + QualType InitType; + if (KnownArraySize) + InitType = Context.getConstantArrayType( + AllocType, + llvm::APInt(Context.getTypeSize(Context.getSizeType()), + *KnownArraySize), + *ArraySize, ArrayType::Normal, 0); + else if (ArraySize) + InitType = + Context.getIncompleteArrayType(AllocType, ArrayType::Normal, 0); + else + InitType = AllocType; + + InitializedEntity Entity + = InitializedEntity::InitializeNew(StartLoc, InitType); + InitializationSequence InitSeq(*this, Entity, Kind, + MultiExprArg(Inits, NumInits)); + ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind, + MultiExprArg(Inits, NumInits)); + if (FullInit.isInvalid()) + return ExprError(); + + // FullInit is our initializer; strip off CXXBindTemporaryExprs, because + // we don't want the initialized object to be destructed. + // FIXME: We should not create these in the first place. + if (CXXBindTemporaryExpr *Binder = + dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get())) + FullInit = Binder->getSubExpr(); + + Initializer = FullInit.get(); + + // FIXME: If we have a KnownArraySize, check that the array bound of the + // initializer is no greater than that constant value. + + if (ArraySize && !*ArraySize) { + auto *CAT = Context.getAsConstantArrayType(Initializer->getType()); + if (CAT) { + // FIXME: Track that the array size was inferred rather than explicitly + // specified. + ArraySize = IntegerLiteral::Create( + Context, CAT->getSize(), Context.getSizeType(), TypeRange.getEnd()); + } else { + Diag(TypeRange.getEnd(), diag::err_new_array_size_unknown_from_init) + << Initializer->getSourceRange(); + } + } + } + + // Mark the new and delete operators as referenced. + if (OperatorNew) { + if (DiagnoseUseOfDecl(OperatorNew, StartLoc)) + return ExprError(); + MarkFunctionReferenced(StartLoc, OperatorNew); + } + if (OperatorDelete) { + if (DiagnoseUseOfDecl(OperatorDelete, StartLoc)) + return ExprError(); + MarkFunctionReferenced(StartLoc, OperatorDelete); + } + + return CXXNewExpr::Create(Context, UseGlobal, OperatorNew, OperatorDelete, + PassAlignment, UsualArrayDeleteWantsSize, + PlacementArgs, TypeIdParens, ArraySize, initStyle, + Initializer, ResultType, AllocTypeInfo, Range, + DirectInitRange); +} + +/// Checks that a type is suitable as the allocated type +/// in a new-expression. +bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc, + SourceRange R) { + // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an + // abstract class type or array thereof. + if (AllocType->isFunctionType()) + return Diag(Loc, diag::err_bad_new_type) + << AllocType << 0 << R; + else if (AllocType->isReferenceType()) + return Diag(Loc, diag::err_bad_new_type) + << AllocType << 1 << R; + else if (!AllocType->isDependentType() && + RequireCompleteType(Loc, AllocType, diag::err_new_incomplete_type,R)) + return true; + else if (RequireNonAbstractType(Loc, AllocType, + diag::err_allocation_of_abstract_type)) + return true; + else if (AllocType->isVariablyModifiedType()) + return Diag(Loc, diag::err_variably_modified_new_type) + << AllocType; + else if (AllocType.getAddressSpace() != LangAS::Default && + !getLangOpts().OpenCLCPlusPlus) + return Diag(Loc, diag::err_address_space_qualified_new) + << AllocType.getUnqualifiedType() + << AllocType.getQualifiers().getAddressSpaceAttributePrintValue(); + else if (getLangOpts().ObjCAutoRefCount) { + if (const ArrayType *AT = Context.getAsArrayType(AllocType)) { + QualType BaseAllocType = Context.getBaseElementType(AT); + if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None && + BaseAllocType->isObjCLifetimeType()) + return Diag(Loc, diag::err_arc_new_array_without_ownership) + << BaseAllocType; + } + } + + return false; +} + +static bool resolveAllocationOverload( + Sema &S, LookupResult &R, SourceRange Range, SmallVectorImpl<Expr *> &Args, + bool &PassAlignment, FunctionDecl *&Operator, + OverloadCandidateSet *AlignedCandidates, Expr *AlignArg, bool Diagnose) { + OverloadCandidateSet Candidates(R.getNameLoc(), + OverloadCandidateSet::CSK_Normal); + for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end(); + Alloc != AllocEnd; ++Alloc) { + // Even member operator new/delete are implicitly treated as + // static, so don't use AddMemberCandidate. + NamedDecl *D = (*Alloc)->getUnderlyingDecl(); + + if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) { + S.AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(), + /*ExplicitTemplateArgs=*/nullptr, Args, + Candidates, + /*SuppressUserConversions=*/false); + continue; + } + + FunctionDecl *Fn = cast<FunctionDecl>(D); + S.AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates, + /*SuppressUserConversions=*/false); + } + + // Do the resolution. + OverloadCandidateSet::iterator Best; + switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) { + case OR_Success: { + // Got one! + FunctionDecl *FnDecl = Best->Function; + if (S.CheckAllocationAccess(R.getNameLoc(), Range, R.getNamingClass(), + Best->FoundDecl) == Sema::AR_inaccessible) + return true; + + Operator = FnDecl; + return false; + } + + case OR_No_Viable_Function: + // C++17 [expr.new]p13: + // If no matching function is found and the allocated object type has + // new-extended alignment, the alignment argument is removed from the + // argument list, and overload resolution is performed again. + if (PassAlignment) { + PassAlignment = false; + AlignArg = Args[1]; + Args.erase(Args.begin() + 1); + return resolveAllocationOverload(S, R, Range, Args, PassAlignment, + Operator, &Candidates, AlignArg, + Diagnose); + } + + // MSVC will fall back on trying to find a matching global operator new + // if operator new[] cannot be found. Also, MSVC will leak by not + // generating a call to operator delete or operator delete[], but we + // will not replicate that bug. + // FIXME: Find out how this interacts with the std::align_val_t fallback + // once MSVC implements it. + if (R.getLookupName().getCXXOverloadedOperator() == OO_Array_New && + S.Context.getLangOpts().MSVCCompat) { + R.clear(); + R.setLookupName(S.Context.DeclarationNames.getCXXOperatorName(OO_New)); + S.LookupQualifiedName(R, S.Context.getTranslationUnitDecl()); + // FIXME: This will give bad diagnostics pointing at the wrong functions. + return resolveAllocationOverload(S, R, Range, Args, PassAlignment, + Operator, /*Candidates=*/nullptr, + /*AlignArg=*/nullptr, Diagnose); + } + + if (Diagnose) { + PartialDiagnosticAt PD(R.getNameLoc(), S.PDiag(diag::err_ovl_no_viable_function_in_call) + << R.getLookupName() << Range); + + // If we have aligned candidates, only note the align_val_t candidates + // from AlignedCandidates and the non-align_val_t candidates from + // Candidates. + if (AlignedCandidates) { + auto IsAligned = [](OverloadCandidate &C) { + return C.Function->getNumParams() > 1 && + C.Function->getParamDecl(1)->getType()->isAlignValT(); + }; + auto IsUnaligned = [&](OverloadCandidate &C) { return !IsAligned(C); }; + + // This was an overaligned allocation, so list the aligned candidates + // first. + Args.insert(Args.begin() + 1, AlignArg); + AlignedCandidates->NoteCandidates(PD, S, OCD_AllCandidates, Args, "", + R.getNameLoc(), IsAligned); + Args.erase(Args.begin() + 1); + Candidates.NoteCandidates(PD, S, OCD_AllCandidates, Args, "", R.getNameLoc(), + IsUnaligned); + } else { + Candidates.NoteCandidates(PD, S, OCD_AllCandidates, Args); + } + } + return true; + + case OR_Ambiguous: + if (Diagnose) { + Candidates.NoteCandidates( + PartialDiagnosticAt(R.getNameLoc(), + S.PDiag(diag::err_ovl_ambiguous_call) + << R.getLookupName() << Range), + S, OCD_ViableCandidates, Args); + } + return true; + + case OR_Deleted: { + if (Diagnose) { + Candidates.NoteCandidates( + PartialDiagnosticAt(R.getNameLoc(), + S.PDiag(diag::err_ovl_deleted_call) + << R.getLookupName() << Range), + S, OCD_AllCandidates, Args); + } + return true; + } + } + llvm_unreachable("Unreachable, bad result from BestViableFunction"); +} + +bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range, + AllocationFunctionScope NewScope, + AllocationFunctionScope DeleteScope, + QualType AllocType, bool IsArray, + bool &PassAlignment, MultiExprArg PlaceArgs, + FunctionDecl *&OperatorNew, + FunctionDecl *&OperatorDelete, + bool Diagnose) { + // --- Choosing an allocation function --- + // C++ 5.3.4p8 - 14 & 18 + // 1) If looking in AFS_Global scope for allocation functions, only look in + // the global scope. Else, if AFS_Class, only look in the scope of the + // allocated class. If AFS_Both, look in both. + // 2) If an array size is given, look for operator new[], else look for + // operator new. + // 3) The first argument is always size_t. Append the arguments from the + // placement form. + + SmallVector<Expr*, 8> AllocArgs; + AllocArgs.reserve((PassAlignment ? 2 : 1) + PlaceArgs.size()); + + // We don't care about the actual value of these arguments. + // FIXME: Should the Sema create the expression and embed it in the syntax + // tree? Or should the consumer just recalculate the value? + // FIXME: Using a dummy value will interact poorly with attribute enable_if. + IntegerLiteral Size(Context, llvm::APInt::getNullValue( + Context.getTargetInfo().getPointerWidth(0)), + Context.getSizeType(), + SourceLocation()); + AllocArgs.push_back(&Size); + + QualType AlignValT = Context.VoidTy; + if (PassAlignment) { + DeclareGlobalNewDelete(); + AlignValT = Context.getTypeDeclType(getStdAlignValT()); + } + CXXScalarValueInitExpr Align(AlignValT, nullptr, SourceLocation()); + if (PassAlignment) + AllocArgs.push_back(&Align); + + AllocArgs.insert(AllocArgs.end(), PlaceArgs.begin(), PlaceArgs.end()); + + // C++ [expr.new]p8: + // If the allocated type is a non-array type, the allocation + // function's name is operator new and the deallocation function's + // name is operator delete. If the allocated type is an array + // type, the allocation function's name is operator new[] and the + // deallocation function's name is operator delete[]. + DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName( + IsArray ? OO_Array_New : OO_New); + + QualType AllocElemType = Context.getBaseElementType(AllocType); + + // Find the allocation function. + { + LookupResult R(*this, NewName, StartLoc, LookupOrdinaryName); + + // C++1z [expr.new]p9: + // If the new-expression begins with a unary :: operator, the allocation + // function's name is looked up in the global scope. Otherwise, if the + // allocated type is a class type T or array thereof, the allocation + // function's name is looked up in the scope of T. + if (AllocElemType->isRecordType() && NewScope != AFS_Global) + LookupQualifiedName(R, AllocElemType->getAsCXXRecordDecl()); + + // We can see ambiguity here if the allocation function is found in + // multiple base classes. + if (R.isAmbiguous()) + return true; + + // If this lookup fails to find the name, or if the allocated type is not + // a class type, the allocation function's name is looked up in the + // global scope. + if (R.empty()) { + if (NewScope == AFS_Class) + return true; + + LookupQualifiedName(R, Context.getTranslationUnitDecl()); + } + + if (getLangOpts().OpenCLCPlusPlus && R.empty()) { + if (PlaceArgs.empty()) { + Diag(StartLoc, diag::err_openclcxx_not_supported) << "default new"; + } else { + Diag(StartLoc, diag::err_openclcxx_placement_new); + } + return true; + } + + assert(!R.empty() && "implicitly declared allocation functions not found"); + assert(!R.isAmbiguous() && "global allocation functions are ambiguous"); + + // We do our own custom access checks below. + R.suppressDiagnostics(); + + if (resolveAllocationOverload(*this, R, Range, AllocArgs, PassAlignment, + OperatorNew, /*Candidates=*/nullptr, + /*AlignArg=*/nullptr, Diagnose)) + return true; + } + + // We don't need an operator delete if we're running under -fno-exceptions. + if (!getLangOpts().Exceptions) { + OperatorDelete = nullptr; + return false; + } + + // Note, the name of OperatorNew might have been changed from array to + // non-array by resolveAllocationOverload. + DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( + OperatorNew->getDeclName().getCXXOverloadedOperator() == OO_Array_New + ? OO_Array_Delete + : OO_Delete); + + // C++ [expr.new]p19: + // + // If the new-expression begins with a unary :: operator, the + // deallocation function's name is looked up in the global + // scope. Otherwise, if the allocated type is a class type T or an + // array thereof, the deallocation function's name is looked up in + // the scope of T. If this lookup fails to find the name, or if + // the allocated type is not a class type or array thereof, the + // deallocation function's name is looked up in the global scope. + LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName); + if (AllocElemType->isRecordType() && DeleteScope != AFS_Global) { + auto *RD = + cast<CXXRecordDecl>(AllocElemType->castAs<RecordType>()->getDecl()); + LookupQualifiedName(FoundDelete, RD); + } + if (FoundDelete.isAmbiguous()) + return true; // FIXME: clean up expressions? + + bool FoundGlobalDelete = FoundDelete.empty(); + if (FoundDelete.empty()) { + if (DeleteScope == AFS_Class) + return true; + + DeclareGlobalNewDelete(); + LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); + } + + FoundDelete.suppressDiagnostics(); + + SmallVector<std::pair<DeclAccessPair,FunctionDecl*>, 2> Matches; + + // Whether we're looking for a placement operator delete is dictated + // by whether we selected a placement operator new, not by whether + // we had explicit placement arguments. This matters for things like + // struct A { void *operator new(size_t, int = 0); ... }; + // A *a = new A() + // + // We don't have any definition for what a "placement allocation function" + // is, but we assume it's any allocation function whose + // parameter-declaration-clause is anything other than (size_t). + // + // FIXME: Should (size_t, std::align_val_t) also be considered non-placement? + // This affects whether an exception from the constructor of an overaligned + // type uses the sized or non-sized form of aligned operator delete. + bool isPlacementNew = !PlaceArgs.empty() || OperatorNew->param_size() != 1 || + OperatorNew->isVariadic(); + + if (isPlacementNew) { + // C++ [expr.new]p20: + // A declaration of a placement deallocation function matches the + // declaration of a placement allocation function if it has the + // same number of parameters and, after parameter transformations + // (8.3.5), all parameter types except the first are + // identical. [...] + // + // To perform this comparison, we compute the function type that + // the deallocation function should have, and use that type both + // for template argument deduction and for comparison purposes. + QualType ExpectedFunctionType; + { + const FunctionProtoType *Proto + = OperatorNew->getType()->getAs<FunctionProtoType>(); + + SmallVector<QualType, 4> ArgTypes; + ArgTypes.push_back(Context.VoidPtrTy); + for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I) + ArgTypes.push_back(Proto->getParamType(I)); + + FunctionProtoType::ExtProtoInfo EPI; + // FIXME: This is not part of the standard's rule. + EPI.Variadic = Proto->isVariadic(); + + ExpectedFunctionType + = Context.getFunctionType(Context.VoidTy, ArgTypes, EPI); + } + + for (LookupResult::iterator D = FoundDelete.begin(), + DEnd = FoundDelete.end(); + D != DEnd; ++D) { + FunctionDecl *Fn = nullptr; + if (FunctionTemplateDecl *FnTmpl = + dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) { + // Perform template argument deduction to try to match the + // expected function type. + TemplateDeductionInfo Info(StartLoc); + if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn, + Info)) + continue; + } else + Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl()); + + if (Context.hasSameType(adjustCCAndNoReturn(Fn->getType(), + ExpectedFunctionType, + /*AdjustExcpetionSpec*/true), + ExpectedFunctionType)) + Matches.push_back(std::make_pair(D.getPair(), Fn)); + } + + if (getLangOpts().CUDA) + EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(CurContext), Matches); + } else { + // C++1y [expr.new]p22: + // For a non-placement allocation function, the normal deallocation + // function lookup is used + // + // Per [expr.delete]p10, this lookup prefers a member operator delete + // without a size_t argument, but prefers a non-member operator delete + // with a size_t where possible (which it always is in this case). + llvm::SmallVector<UsualDeallocFnInfo, 4> BestDeallocFns; + UsualDeallocFnInfo Selected = resolveDeallocationOverload( + *this, FoundDelete, /*WantSize*/ FoundGlobalDelete, + /*WantAlign*/ hasNewExtendedAlignment(*this, AllocElemType), + &BestDeallocFns); + if (Selected) + Matches.push_back(std::make_pair(Selected.Found, Selected.FD)); + else { + // If we failed to select an operator, all remaining functions are viable + // but ambiguous. + for (auto Fn : BestDeallocFns) + Matches.push_back(std::make_pair(Fn.Found, Fn.FD)); + } + } + + // C++ [expr.new]p20: + // [...] If the lookup finds a single matching deallocation + // function, that function will be called; otherwise, no + // deallocation function will be called. + if (Matches.size() == 1) { + OperatorDelete = Matches[0].second; + + // C++1z [expr.new]p23: + // If the lookup finds a usual deallocation function (3.7.4.2) + // with a parameter of type std::size_t and that function, considered + // as a placement deallocation function, would have been + // selected as a match for the allocation function, the program + // is ill-formed. + if (getLangOpts().CPlusPlus11 && isPlacementNew && + isNonPlacementDeallocationFunction(*this, OperatorDelete)) { + UsualDeallocFnInfo Info(*this, + DeclAccessPair::make(OperatorDelete, AS_public)); + // Core issue, per mail to core reflector, 2016-10-09: + // If this is a member operator delete, and there is a corresponding + // non-sized member operator delete, this isn't /really/ a sized + // deallocation function, it just happens to have a size_t parameter. + bool IsSizedDelete = Info.HasSizeT; + if (IsSizedDelete && !FoundGlobalDelete) { + auto NonSizedDelete = + resolveDeallocationOverload(*this, FoundDelete, /*WantSize*/false, + /*WantAlign*/Info.HasAlignValT); + if (NonSizedDelete && !NonSizedDelete.HasSizeT && + NonSizedDelete.HasAlignValT == Info.HasAlignValT) + IsSizedDelete = false; + } + + if (IsSizedDelete) { + SourceRange R = PlaceArgs.empty() + ? SourceRange() + : SourceRange(PlaceArgs.front()->getBeginLoc(), + PlaceArgs.back()->getEndLoc()); + Diag(StartLoc, diag::err_placement_new_non_placement_delete) << R; + if (!OperatorDelete->isImplicit()) + Diag(OperatorDelete->getLocation(), diag::note_previous_decl) + << DeleteName; + } + } + + CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(), + Matches[0].first); + } else if (!Matches.empty()) { + // We found multiple suitable operators. Per [expr.new]p20, that means we + // call no 'operator delete' function, but we should at least warn the user. + // FIXME: Suppress this warning if the construction cannot throw. + Diag(StartLoc, diag::warn_ambiguous_suitable_delete_function_found) + << DeleteName << AllocElemType; + + for (auto &Match : Matches) + Diag(Match.second->getLocation(), + diag::note_member_declared_here) << DeleteName; + } + + return false; +} + +/// DeclareGlobalNewDelete - Declare the global forms of operator new and +/// delete. These are: +/// @code +/// // C++03: +/// void* operator new(std::size_t) throw(std::bad_alloc); +/// void* operator new[](std::size_t) throw(std::bad_alloc); +/// void operator delete(void *) throw(); +/// void operator delete[](void *) throw(); +/// // C++11: +/// void* operator new(std::size_t); +/// void* operator new[](std::size_t); +/// void operator delete(void *) noexcept; +/// void operator delete[](void *) noexcept; +/// // C++1y: +/// void* operator new(std::size_t); +/// void* operator new[](std::size_t); +/// void operator delete(void *) noexcept; +/// void operator delete[](void *) noexcept; +/// void operator delete(void *, std::size_t) noexcept; +/// void operator delete[](void *, std::size_t) noexcept; +/// @endcode +/// Note that the placement and nothrow forms of new are *not* implicitly +/// declared. Their use requires including \<new\>. +void Sema::DeclareGlobalNewDelete() { + if (GlobalNewDeleteDeclared) + return; + + // The implicitly declared new and delete operators + // are not supported in OpenCL. + if (getLangOpts().OpenCLCPlusPlus) + return; + + // C++ [basic.std.dynamic]p2: + // [...] The following allocation and deallocation functions (18.4) are + // implicitly declared in global scope in each translation unit of a + // program + // + // C++03: + // void* operator new(std::size_t) throw(std::bad_alloc); + // void* operator new[](std::size_t) throw(std::bad_alloc); + // void operator delete(void*) throw(); + // void operator delete[](void*) throw(); + // C++11: + // void* operator new(std::size_t); + // void* operator new[](std::size_t); + // void operator delete(void*) noexcept; + // void operator delete[](void*) noexcept; + // C++1y: + // void* operator new(std::size_t); + // void* operator new[](std::size_t); + // void operator delete(void*) noexcept; + // void operator delete[](void*) noexcept; + // void operator delete(void*, std::size_t) noexcept; + // void operator delete[](void*, std::size_t) noexcept; + // + // These implicit declarations introduce only the function names operator + // new, operator new[], operator delete, operator delete[]. + // + // Here, we need to refer to std::bad_alloc, so we will implicitly declare + // "std" or "bad_alloc" as necessary to form the exception specification. + // However, we do not make these implicit declarations visible to name + // lookup. + if (!StdBadAlloc && !getLangOpts().CPlusPlus11) { + // The "std::bad_alloc" class has not yet been declared, so build it + // implicitly. + StdBadAlloc = CXXRecordDecl::Create(Context, TTK_Class, + getOrCreateStdNamespace(), + SourceLocation(), SourceLocation(), + &PP.getIdentifierTable().get("bad_alloc"), + nullptr); + getStdBadAlloc()->setImplicit(true); + } + if (!StdAlignValT && getLangOpts().AlignedAllocation) { + // The "std::align_val_t" enum class has not yet been declared, so build it + // implicitly. + auto *AlignValT = EnumDecl::Create( + Context, getOrCreateStdNamespace(), SourceLocation(), SourceLocation(), + &PP.getIdentifierTable().get("align_val_t"), nullptr, true, true, true); + AlignValT->setIntegerType(Context.getSizeType()); + AlignValT->setPromotionType(Context.getSizeType()); + AlignValT->setImplicit(true); + StdAlignValT = AlignValT; + } + + GlobalNewDeleteDeclared = true; + + QualType VoidPtr = Context.getPointerType(Context.VoidTy); + QualType SizeT = Context.getSizeType(); + + auto DeclareGlobalAllocationFunctions = [&](OverloadedOperatorKind Kind, + QualType Return, QualType Param) { + llvm::SmallVector<QualType, 3> Params; + Params.push_back(Param); + + // Create up to four variants of the function (sized/aligned). + bool HasSizedVariant = getLangOpts().SizedDeallocation && + (Kind == OO_Delete || Kind == OO_Array_Delete); + bool HasAlignedVariant = getLangOpts().AlignedAllocation; + + int NumSizeVariants = (HasSizedVariant ? 2 : 1); + int NumAlignVariants = (HasAlignedVariant ? 2 : 1); + for (int Sized = 0; Sized < NumSizeVariants; ++Sized) { + if (Sized) + Params.push_back(SizeT); + + for (int Aligned = 0; Aligned < NumAlignVariants; ++Aligned) { + if (Aligned) + Params.push_back(Context.getTypeDeclType(getStdAlignValT())); + + DeclareGlobalAllocationFunction( + Context.DeclarationNames.getCXXOperatorName(Kind), Return, Params); + + if (Aligned) + Params.pop_back(); + } + } + }; + + DeclareGlobalAllocationFunctions(OO_New, VoidPtr, SizeT); + DeclareGlobalAllocationFunctions(OO_Array_New, VoidPtr, SizeT); + DeclareGlobalAllocationFunctions(OO_Delete, Context.VoidTy, VoidPtr); + DeclareGlobalAllocationFunctions(OO_Array_Delete, Context.VoidTy, VoidPtr); +} + +/// DeclareGlobalAllocationFunction - Declares a single implicit global +/// allocation function if it doesn't already exist. +void Sema::DeclareGlobalAllocationFunction(DeclarationName Name, + QualType Return, + ArrayRef<QualType> Params) { + DeclContext *GlobalCtx = Context.getTranslationUnitDecl(); + + // Check if this function is already declared. + DeclContext::lookup_result R = GlobalCtx->lookup(Name); + for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end(); + Alloc != AllocEnd; ++Alloc) { + // Only look at non-template functions, as it is the predefined, + // non-templated allocation function we are trying to declare here. + if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) { + if (Func->getNumParams() == Params.size()) { + llvm::SmallVector<QualType, 3> FuncParams; + for (auto *P : Func->parameters()) + FuncParams.push_back( + Context.getCanonicalType(P->getType().getUnqualifiedType())); + if (llvm::makeArrayRef(FuncParams) == Params) { + // Make the function visible to name lookup, even if we found it in + // an unimported module. It either is an implicitly-declared global + // allocation function, or is suppressing that function. + Func->setVisibleDespiteOwningModule(); + return; + } + } + } + } + + FunctionProtoType::ExtProtoInfo EPI(Context.getDefaultCallingConvention( + /*IsVariadic=*/false, /*IsCXXMethod=*/false, /*IsBuiltin=*/true)); + + QualType BadAllocType; + bool HasBadAllocExceptionSpec + = (Name.getCXXOverloadedOperator() == OO_New || + Name.getCXXOverloadedOperator() == OO_Array_New); + if (HasBadAllocExceptionSpec) { + if (!getLangOpts().CPlusPlus11) { + BadAllocType = Context.getTypeDeclType(getStdBadAlloc()); + assert(StdBadAlloc && "Must have std::bad_alloc declared"); + EPI.ExceptionSpec.Type = EST_Dynamic; + EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType); + } + } else { + EPI.ExceptionSpec = + getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone; + } + + auto CreateAllocationFunctionDecl = [&](Attr *ExtraAttr) { + QualType FnType = Context.getFunctionType(Return, Params, EPI); + FunctionDecl *Alloc = FunctionDecl::Create( + Context, GlobalCtx, SourceLocation(), SourceLocation(), Name, + FnType, /*TInfo=*/nullptr, SC_None, false, true); + Alloc->setImplicit(); + // Global allocation functions should always be visible. + Alloc->setVisibleDespiteOwningModule(); + + Alloc->addAttr(VisibilityAttr::CreateImplicit( + Context, LangOpts.GlobalAllocationFunctionVisibilityHidden + ? VisibilityAttr::Hidden + : VisibilityAttr::Default)); + + llvm::SmallVector<ParmVarDecl *, 3> ParamDecls; + for (QualType T : Params) { + ParamDecls.push_back(ParmVarDecl::Create( + Context, Alloc, SourceLocation(), SourceLocation(), nullptr, T, + /*TInfo=*/nullptr, SC_None, nullptr)); + ParamDecls.back()->setImplicit(); + } + Alloc->setParams(ParamDecls); + if (ExtraAttr) + Alloc->addAttr(ExtraAttr); + Context.getTranslationUnitDecl()->addDecl(Alloc); + IdResolver.tryAddTopLevelDecl(Alloc, Name); + }; + + if (!LangOpts.CUDA) + CreateAllocationFunctionDecl(nullptr); + else { + // Host and device get their own declaration so each can be + // defined or re-declared independently. + CreateAllocationFunctionDecl(CUDAHostAttr::CreateImplicit(Context)); + CreateAllocationFunctionDecl(CUDADeviceAttr::CreateImplicit(Context)); + } +} + +FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc, + bool CanProvideSize, + bool Overaligned, + DeclarationName Name) { + DeclareGlobalNewDelete(); + + LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName); + LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); + + // FIXME: It's possible for this to result in ambiguity, through a + // user-declared variadic operator delete or the enable_if attribute. We + // should probably not consider those cases to be usual deallocation + // functions. But for now we just make an arbitrary choice in that case. + auto Result = resolveDeallocationOverload(*this, FoundDelete, CanProvideSize, + Overaligned); + assert(Result.FD && "operator delete missing from global scope?"); + return Result.FD; +} + +FunctionDecl *Sema::FindDeallocationFunctionForDestructor(SourceLocation Loc, + CXXRecordDecl *RD) { + DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Delete); + + FunctionDecl *OperatorDelete = nullptr; + if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete)) + return nullptr; + if (OperatorDelete) + return OperatorDelete; + + // If there's no class-specific operator delete, look up the global + // non-array delete. + return FindUsualDeallocationFunction( + Loc, true, hasNewExtendedAlignment(*this, Context.getRecordType(RD)), + Name); +} + +bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD, + DeclarationName Name, + FunctionDecl *&Operator, bool Diagnose) { + LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName); + // Try to find operator delete/operator delete[] in class scope. + LookupQualifiedName(Found, RD); + + if (Found.isAmbiguous()) + return true; + + Found.suppressDiagnostics(); + + bool Overaligned = hasNewExtendedAlignment(*this, Context.getRecordType(RD)); + + // C++17 [expr.delete]p10: + // If the deallocation functions have class scope, the one without a + // parameter of type std::size_t is selected. + llvm::SmallVector<UsualDeallocFnInfo, 4> Matches; + resolveDeallocationOverload(*this, Found, /*WantSize*/ false, + /*WantAlign*/ Overaligned, &Matches); + + // If we could find an overload, use it. + if (Matches.size() == 1) { + Operator = cast<CXXMethodDecl>(Matches[0].FD); + + // FIXME: DiagnoseUseOfDecl? + if (Operator->isDeleted()) { + if (Diagnose) { + Diag(StartLoc, diag::err_deleted_function_use); + NoteDeletedFunction(Operator); + } + return true; + } + + if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(), + Matches[0].Found, Diagnose) == AR_inaccessible) + return true; + + return false; + } + + // We found multiple suitable operators; complain about the ambiguity. + // FIXME: The standard doesn't say to do this; it appears that the intent + // is that this should never happen. + if (!Matches.empty()) { + if (Diagnose) { + Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found) + << Name << RD; + for (auto &Match : Matches) + Diag(Match.FD->getLocation(), diag::note_member_declared_here) << Name; + } + return true; + } + + // We did find operator delete/operator delete[] declarations, but + // none of them were suitable. + if (!Found.empty()) { + if (Diagnose) { + Diag(StartLoc, diag::err_no_suitable_delete_member_function_found) + << Name << RD; + + for (NamedDecl *D : Found) + Diag(D->getUnderlyingDecl()->getLocation(), + diag::note_member_declared_here) << Name; + } + return true; + } + + Operator = nullptr; + return false; +} + +namespace { +/// Checks whether delete-expression, and new-expression used for +/// initializing deletee have the same array form. +class MismatchingNewDeleteDetector { +public: + enum MismatchResult { + /// Indicates that there is no mismatch or a mismatch cannot be proven. + NoMismatch, + /// Indicates that variable is initialized with mismatching form of \a new. + VarInitMismatches, + /// Indicates that member is initialized with mismatching form of \a new. + MemberInitMismatches, + /// Indicates that 1 or more constructors' definitions could not been + /// analyzed, and they will be checked again at the end of translation unit. + AnalyzeLater + }; + + /// \param EndOfTU True, if this is the final analysis at the end of + /// translation unit. False, if this is the initial analysis at the point + /// delete-expression was encountered. + explicit MismatchingNewDeleteDetector(bool EndOfTU) + : Field(nullptr), IsArrayForm(false), EndOfTU(EndOfTU), + HasUndefinedConstructors(false) {} + + /// Checks whether pointee of a delete-expression is initialized with + /// matching form of new-expression. + /// + /// If return value is \c VarInitMismatches or \c MemberInitMismatches at the + /// point where delete-expression is encountered, then a warning will be + /// issued immediately. If return value is \c AnalyzeLater at the point where + /// delete-expression is seen, then member will be analyzed at the end of + /// translation unit. \c AnalyzeLater is returned iff at least one constructor + /// couldn't be analyzed. If at least one constructor initializes the member + /// with matching type of new, the return value is \c NoMismatch. + MismatchResult analyzeDeleteExpr(const CXXDeleteExpr *DE); + /// Analyzes a class member. + /// \param Field Class member to analyze. + /// \param DeleteWasArrayForm Array form-ness of the delete-expression used + /// for deleting the \p Field. + MismatchResult analyzeField(FieldDecl *Field, bool DeleteWasArrayForm); + FieldDecl *Field; + /// List of mismatching new-expressions used for initialization of the pointee + llvm::SmallVector<const CXXNewExpr *, 4> NewExprs; + /// Indicates whether delete-expression was in array form. + bool IsArrayForm; + +private: + const bool EndOfTU; + /// Indicates that there is at least one constructor without body. + bool HasUndefinedConstructors; + /// Returns \c CXXNewExpr from given initialization expression. + /// \param E Expression used for initializing pointee in delete-expression. + /// E can be a single-element \c InitListExpr consisting of new-expression. + const CXXNewExpr *getNewExprFromInitListOrExpr(const Expr *E); + /// Returns whether member is initialized with mismatching form of + /// \c new either by the member initializer or in-class initialization. + /// + /// If bodies of all constructors are not visible at the end of translation + /// unit or at least one constructor initializes member with the matching + /// form of \c new, mismatch cannot be proven, and this function will return + /// \c NoMismatch. + MismatchResult analyzeMemberExpr(const MemberExpr *ME); + /// Returns whether variable is initialized with mismatching form of + /// \c new. + /// + /// If variable is initialized with matching form of \c new or variable is not + /// initialized with a \c new expression, this function will return true. + /// If variable is initialized with mismatching form of \c new, returns false. + /// \param D Variable to analyze. + bool hasMatchingVarInit(const DeclRefExpr *D); + /// Checks whether the constructor initializes pointee with mismatching + /// form of \c new. + /// + /// Returns true, if member is initialized with matching form of \c new in + /// member initializer list. Returns false, if member is initialized with the + /// matching form of \c new in this constructor's initializer or given + /// constructor isn't defined at the point where delete-expression is seen, or + /// member isn't initialized by the constructor. + bool hasMatchingNewInCtor(const CXXConstructorDecl *CD); + /// Checks whether member is initialized with matching form of + /// \c new in member initializer list. + bool hasMatchingNewInCtorInit(const CXXCtorInitializer *CI); + /// Checks whether member is initialized with mismatching form of \c new by + /// in-class initializer. + MismatchResult analyzeInClassInitializer(); +}; +} + +MismatchingNewDeleteDetector::MismatchResult +MismatchingNewDeleteDetector::analyzeDeleteExpr(const CXXDeleteExpr *DE) { + NewExprs.clear(); + assert(DE && "Expected delete-expression"); + IsArrayForm = DE->isArrayForm(); + const Expr *E = DE->getArgument()->IgnoreParenImpCasts(); + if (const MemberExpr *ME = dyn_cast<const MemberExpr>(E)) { + return analyzeMemberExpr(ME); + } else if (const DeclRefExpr *D = dyn_cast<const DeclRefExpr>(E)) { + if (!hasMatchingVarInit(D)) + return VarInitMismatches; + } + return NoMismatch; +} + +const CXXNewExpr * +MismatchingNewDeleteDetector::getNewExprFromInitListOrExpr(const Expr *E) { + assert(E != nullptr && "Expected a valid initializer expression"); + E = E->IgnoreParenImpCasts(); + if (const InitListExpr *ILE = dyn_cast<const InitListExpr>(E)) { + if (ILE->getNumInits() == 1) + E = dyn_cast<const CXXNewExpr>(ILE->getInit(0)->IgnoreParenImpCasts()); + } + + return dyn_cast_or_null<const CXXNewExpr>(E); +} + +bool MismatchingNewDeleteDetector::hasMatchingNewInCtorInit( + const CXXCtorInitializer *CI) { + const CXXNewExpr *NE = nullptr; + if (Field == CI->getMember() && + (NE = getNewExprFromInitListOrExpr(CI->getInit()))) { + if (NE->isArray() == IsArrayForm) + return true; + else + NewExprs.push_back(NE); + } + return false; +} + +bool MismatchingNewDeleteDetector::hasMatchingNewInCtor( + const CXXConstructorDecl *CD) { + if (CD->isImplicit()) + return false; + const FunctionDecl *Definition = CD; + if (!CD->isThisDeclarationADefinition() && !CD->isDefined(Definition)) { + HasUndefinedConstructors = true; + return EndOfTU; + } + for (const auto *CI : cast<const CXXConstructorDecl>(Definition)->inits()) { + if (hasMatchingNewInCtorInit(CI)) + return true; + } + return false; +} + +MismatchingNewDeleteDetector::MismatchResult +MismatchingNewDeleteDetector::analyzeInClassInitializer() { + assert(Field != nullptr && "This should be called only for members"); + const Expr *InitExpr = Field->getInClassInitializer(); + if (!InitExpr) + return EndOfTU ? NoMismatch : AnalyzeLater; + if (const CXXNewExpr *NE = getNewExprFromInitListOrExpr(InitExpr)) { + if (NE->isArray() != IsArrayForm) { + NewExprs.push_back(NE); + return MemberInitMismatches; + } + } + return NoMismatch; +} + +MismatchingNewDeleteDetector::MismatchResult +MismatchingNewDeleteDetector::analyzeField(FieldDecl *Field, + bool DeleteWasArrayForm) { + assert(Field != nullptr && "Analysis requires a valid class member."); + this->Field = Field; + IsArrayForm = DeleteWasArrayForm; + const CXXRecordDecl *RD = cast<const CXXRecordDecl>(Field->getParent()); + for (const auto *CD : RD->ctors()) { + if (hasMatchingNewInCtor(CD)) + return NoMismatch; + } + if (HasUndefinedConstructors) + return EndOfTU ? NoMismatch : AnalyzeLater; + if (!NewExprs.empty()) + return MemberInitMismatches; + return Field->hasInClassInitializer() ? analyzeInClassInitializer() + : NoMismatch; +} + +MismatchingNewDeleteDetector::MismatchResult +MismatchingNewDeleteDetector::analyzeMemberExpr(const MemberExpr *ME) { + assert(ME != nullptr && "Expected a member expression"); + if (FieldDecl *F = dyn_cast<FieldDecl>(ME->getMemberDecl())) + return analyzeField(F, IsArrayForm); + return NoMismatch; +} + +bool MismatchingNewDeleteDetector::hasMatchingVarInit(const DeclRefExpr *D) { + const CXXNewExpr *NE = nullptr; + if (const VarDecl *VD = dyn_cast<const VarDecl>(D->getDecl())) { + if (VD->hasInit() && (NE = getNewExprFromInitListOrExpr(VD->getInit())) && + NE->isArray() != IsArrayForm) { + NewExprs.push_back(NE); + } + } + return NewExprs.empty(); +} + +static void +DiagnoseMismatchedNewDelete(Sema &SemaRef, SourceLocation DeleteLoc, + const MismatchingNewDeleteDetector &Detector) { + SourceLocation EndOfDelete = SemaRef.getLocForEndOfToken(DeleteLoc); + FixItHint H; + if (!Detector.IsArrayForm) + H = FixItHint::CreateInsertion(EndOfDelete, "[]"); + else { + SourceLocation RSquare = Lexer::findLocationAfterToken( + DeleteLoc, tok::l_square, SemaRef.getSourceManager(), + SemaRef.getLangOpts(), true); + if (RSquare.isValid()) + H = FixItHint::CreateRemoval(SourceRange(EndOfDelete, RSquare)); + } + SemaRef.Diag(DeleteLoc, diag::warn_mismatched_delete_new) + << Detector.IsArrayForm << H; + + for (const auto *NE : Detector.NewExprs) + SemaRef.Diag(NE->getExprLoc(), diag::note_allocated_here) + << Detector.IsArrayForm; +} + +void Sema::AnalyzeDeleteExprMismatch(const CXXDeleteExpr *DE) { + if (Diags.isIgnored(diag::warn_mismatched_delete_new, SourceLocation())) + return; + MismatchingNewDeleteDetector Detector(/*EndOfTU=*/false); + switch (Detector.analyzeDeleteExpr(DE)) { + case MismatchingNewDeleteDetector::VarInitMismatches: + case MismatchingNewDeleteDetector::MemberInitMismatches: { + DiagnoseMismatchedNewDelete(*this, DE->getBeginLoc(), Detector); + break; + } + case MismatchingNewDeleteDetector::AnalyzeLater: { + DeleteExprs[Detector.Field].push_back( + std::make_pair(DE->getBeginLoc(), DE->isArrayForm())); + break; + } + case MismatchingNewDeleteDetector::NoMismatch: + break; + } +} + +void Sema::AnalyzeDeleteExprMismatch(FieldDecl *Field, SourceLocation DeleteLoc, + bool DeleteWasArrayForm) { + MismatchingNewDeleteDetector Detector(/*EndOfTU=*/true); + switch (Detector.analyzeField(Field, DeleteWasArrayForm)) { + case MismatchingNewDeleteDetector::VarInitMismatches: + llvm_unreachable("This analysis should have been done for class members."); + case MismatchingNewDeleteDetector::AnalyzeLater: + llvm_unreachable("Analysis cannot be postponed any point beyond end of " + "translation unit."); + case MismatchingNewDeleteDetector::MemberInitMismatches: + DiagnoseMismatchedNewDelete(*this, DeleteLoc, Detector); + break; + case MismatchingNewDeleteDetector::NoMismatch: + break; + } +} + +/// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in: +/// @code ::delete ptr; @endcode +/// or +/// @code delete [] ptr; @endcode +ExprResult +Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal, + bool ArrayForm, Expr *ExE) { + // C++ [expr.delete]p1: + // The operand shall have a pointer type, or a class type having a single + // non-explicit conversion function to a pointer type. The result has type + // void. + // + // DR599 amends "pointer type" to "pointer to object type" in both cases. + + ExprResult Ex = ExE; + FunctionDecl *OperatorDelete = nullptr; + bool ArrayFormAsWritten = ArrayForm; + bool UsualArrayDeleteWantsSize = false; + + if (!Ex.get()->isTypeDependent()) { + // Perform lvalue-to-rvalue cast, if needed. + Ex = DefaultLvalueConversion(Ex.get()); + if (Ex.isInvalid()) + return ExprError(); + + QualType Type = Ex.get()->getType(); + + class DeleteConverter : public ContextualImplicitConverter { + public: + DeleteConverter() : ContextualImplicitConverter(false, true) {} + + bool match(QualType ConvType) override { + // FIXME: If we have an operator T* and an operator void*, we must pick + // the operator T*. + if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) + if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType()) + return true; + return false; + } + + SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc, + QualType T) override { + return S.Diag(Loc, diag::err_delete_operand) << T; + } + + SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc, + QualType T) override { + return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T; + } + + SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc, + QualType T, + QualType ConvTy) override { + return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy; + } + + SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv, + QualType ConvTy) override { + return S.Diag(Conv->getLocation(), diag::note_delete_conversion) + << ConvTy; + } + + SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc, + QualType T) override { + return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T; + } + + SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv, + QualType ConvTy) override { + return S.Diag(Conv->getLocation(), diag::note_delete_conversion) + << ConvTy; + } + + SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc, + QualType T, + QualType ConvTy) override { + llvm_unreachable("conversion functions are permitted"); + } + } Converter; + + Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter); + if (Ex.isInvalid()) + return ExprError(); + Type = Ex.get()->getType(); + if (!Converter.match(Type)) + // FIXME: PerformContextualImplicitConversion should return ExprError + // itself in this case. + return ExprError(); + + QualType Pointee = Type->castAs<PointerType>()->getPointeeType(); + QualType PointeeElem = Context.getBaseElementType(Pointee); + + if (Pointee.getAddressSpace() != LangAS::Default && + !getLangOpts().OpenCLCPlusPlus) + return Diag(Ex.get()->getBeginLoc(), + diag::err_address_space_qualified_delete) + << Pointee.getUnqualifiedType() + << Pointee.getQualifiers().getAddressSpaceAttributePrintValue(); + + CXXRecordDecl *PointeeRD = nullptr; + if (Pointee->isVoidType() && !isSFINAEContext()) { + // The C++ standard bans deleting a pointer to a non-object type, which + // effectively bans deletion of "void*". However, most compilers support + // this, so we treat it as a warning unless we're in a SFINAE context. + Diag(StartLoc, diag::ext_delete_void_ptr_operand) + << Type << Ex.get()->getSourceRange(); + } else if (Pointee->isFunctionType() || Pointee->isVoidType()) { + return ExprError(Diag(StartLoc, diag::err_delete_operand) + << Type << Ex.get()->getSourceRange()); + } else if (!Pointee->isDependentType()) { + // FIXME: This can result in errors if the definition was imported from a + // module but is hidden. + if (!RequireCompleteType(StartLoc, Pointee, + diag::warn_delete_incomplete, Ex.get())) { + if (const RecordType *RT = PointeeElem->getAs<RecordType>()) + PointeeRD = cast<CXXRecordDecl>(RT->getDecl()); + } + } + + if (Pointee->isArrayType() && !ArrayForm) { + Diag(StartLoc, diag::warn_delete_array_type) + << Type << Ex.get()->getSourceRange() + << FixItHint::CreateInsertion(getLocForEndOfToken(StartLoc), "[]"); + ArrayForm = true; + } + + DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( + ArrayForm ? OO_Array_Delete : OO_Delete); + + if (PointeeRD) { + if (!UseGlobal && + FindDeallocationFunction(StartLoc, PointeeRD, DeleteName, + OperatorDelete)) + return ExprError(); + + // If we're allocating an array of records, check whether the + // usual operator delete[] has a size_t parameter. + if (ArrayForm) { + // If the user specifically asked to use the global allocator, + // we'll need to do the lookup into the class. + if (UseGlobal) + UsualArrayDeleteWantsSize = + doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem); + + // Otherwise, the usual operator delete[] should be the + // function we just found. + else if (OperatorDelete && isa<CXXMethodDecl>(OperatorDelete)) + UsualArrayDeleteWantsSize = + UsualDeallocFnInfo(*this, + DeclAccessPair::make(OperatorDelete, AS_public)) + .HasSizeT; + } + + if (!PointeeRD->hasIrrelevantDestructor()) + if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { + MarkFunctionReferenced(StartLoc, + const_cast<CXXDestructorDecl*>(Dtor)); + if (DiagnoseUseOfDecl(Dtor, StartLoc)) + return ExprError(); + } + + CheckVirtualDtorCall(PointeeRD->getDestructor(), StartLoc, + /*IsDelete=*/true, /*CallCanBeVirtual=*/true, + /*WarnOnNonAbstractTypes=*/!ArrayForm, + SourceLocation()); + } + + if (!OperatorDelete) { + if (getLangOpts().OpenCLCPlusPlus) { + Diag(StartLoc, diag::err_openclcxx_not_supported) << "default delete"; + return ExprError(); + } + + bool IsComplete = isCompleteType(StartLoc, Pointee); + bool CanProvideSize = + IsComplete && (!ArrayForm || UsualArrayDeleteWantsSize || + Pointee.isDestructedType()); + bool Overaligned = hasNewExtendedAlignment(*this, Pointee); + + // Look for a global declaration. + OperatorDelete = FindUsualDeallocationFunction(StartLoc, CanProvideSize, + Overaligned, DeleteName); + } + + MarkFunctionReferenced(StartLoc, OperatorDelete); + + // Check access and ambiguity of destructor if we're going to call it. + // Note that this is required even for a virtual delete. + bool IsVirtualDelete = false; + if (PointeeRD) { + if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { + CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor, + PDiag(diag::err_access_dtor) << PointeeElem); + IsVirtualDelete = Dtor->isVirtual(); + } + } + + DiagnoseUseOfDecl(OperatorDelete, StartLoc); + + // Convert the operand to the type of the first parameter of operator + // delete. This is only necessary if we selected a destroying operator + // delete that we are going to call (non-virtually); converting to void* + // is trivial and left to AST consumers to handle. + QualType ParamType = OperatorDelete->getParamDecl(0)->getType(); + if (!IsVirtualDelete && !ParamType->getPointeeType()->isVoidType()) { + Qualifiers Qs = Pointee.getQualifiers(); + if (Qs.hasCVRQualifiers()) { + // Qualifiers are irrelevant to this conversion; we're only looking + // for access and ambiguity. + Qs.removeCVRQualifiers(); + QualType Unqual = Context.getPointerType( + Context.getQualifiedType(Pointee.getUnqualifiedType(), Qs)); + Ex = ImpCastExprToType(Ex.get(), Unqual, CK_NoOp); + } + Ex = PerformImplicitConversion(Ex.get(), ParamType, AA_Passing); + if (Ex.isInvalid()) + return ExprError(); + } + } + + CXXDeleteExpr *Result = new (Context) CXXDeleteExpr( + Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten, + UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc); + AnalyzeDeleteExprMismatch(Result); + return Result; +} + +static bool resolveBuiltinNewDeleteOverload(Sema &S, CallExpr *TheCall, + bool IsDelete, + FunctionDecl *&Operator) { + + DeclarationName NewName = S.Context.DeclarationNames.getCXXOperatorName( + IsDelete ? OO_Delete : OO_New); + + LookupResult R(S, NewName, TheCall->getBeginLoc(), Sema::LookupOrdinaryName); + S.LookupQualifiedName(R, S.Context.getTranslationUnitDecl()); + assert(!R.empty() && "implicitly declared allocation functions not found"); + assert(!R.isAmbiguous() && "global allocation functions are ambiguous"); + + // We do our own custom access checks below. + R.suppressDiagnostics(); + + SmallVector<Expr *, 8> Args(TheCall->arg_begin(), TheCall->arg_end()); + OverloadCandidateSet Candidates(R.getNameLoc(), + OverloadCandidateSet::CSK_Normal); + for (LookupResult::iterator FnOvl = R.begin(), FnOvlEnd = R.end(); + FnOvl != FnOvlEnd; ++FnOvl) { + // Even member operator new/delete are implicitly treated as + // static, so don't use AddMemberCandidate. + NamedDecl *D = (*FnOvl)->getUnderlyingDecl(); + + if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) { + S.AddTemplateOverloadCandidate(FnTemplate, FnOvl.getPair(), + /*ExplicitTemplateArgs=*/nullptr, Args, + Candidates, + /*SuppressUserConversions=*/false); + continue; + } + + FunctionDecl *Fn = cast<FunctionDecl>(D); + S.AddOverloadCandidate(Fn, FnOvl.getPair(), Args, Candidates, + /*SuppressUserConversions=*/false); + } + + SourceRange Range = TheCall->getSourceRange(); + + // Do the resolution. + OverloadCandidateSet::iterator Best; + switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) { + case OR_Success: { + // Got one! + FunctionDecl *FnDecl = Best->Function; + assert(R.getNamingClass() == nullptr && + "class members should not be considered"); + + if (!FnDecl->isReplaceableGlobalAllocationFunction()) { + S.Diag(R.getNameLoc(), diag::err_builtin_operator_new_delete_not_usual) + << (IsDelete ? 1 : 0) << Range; + S.Diag(FnDecl->getLocation(), diag::note_non_usual_function_declared_here) + << R.getLookupName() << FnDecl->getSourceRange(); + return true; + } + + Operator = FnDecl; + return false; + } + + case OR_No_Viable_Function: + Candidates.NoteCandidates( + PartialDiagnosticAt(R.getNameLoc(), + S.PDiag(diag::err_ovl_no_viable_function_in_call) + << R.getLookupName() << Range), + S, OCD_AllCandidates, Args); + return true; + + case OR_Ambiguous: + Candidates.NoteCandidates( + PartialDiagnosticAt(R.getNameLoc(), + S.PDiag(diag::err_ovl_ambiguous_call) + << R.getLookupName() << Range), + S, OCD_ViableCandidates, Args); + return true; + + case OR_Deleted: { + Candidates.NoteCandidates( + PartialDiagnosticAt(R.getNameLoc(), S.PDiag(diag::err_ovl_deleted_call) + << R.getLookupName() << Range), + S, OCD_AllCandidates, Args); + return true; + } + } + llvm_unreachable("Unreachable, bad result from BestViableFunction"); +} + +ExprResult +Sema::SemaBuiltinOperatorNewDeleteOverloaded(ExprResult TheCallResult, + bool IsDelete) { + CallExpr *TheCall = cast<CallExpr>(TheCallResult.get()); + if (!getLangOpts().CPlusPlus) { + Diag(TheCall->getExprLoc(), diag::err_builtin_requires_language) + << (IsDelete ? "__builtin_operator_delete" : "__builtin_operator_new") + << "C++"; + return ExprError(); + } + // CodeGen assumes it can find the global new and delete to call, + // so ensure that they are declared. + DeclareGlobalNewDelete(); + + FunctionDecl *OperatorNewOrDelete = nullptr; + if (resolveBuiltinNewDeleteOverload(*this, TheCall, IsDelete, + OperatorNewOrDelete)) + return ExprError(); + assert(OperatorNewOrDelete && "should be found"); + + DiagnoseUseOfDecl(OperatorNewOrDelete, TheCall->getExprLoc()); + MarkFunctionReferenced(TheCall->getExprLoc(), OperatorNewOrDelete); + + TheCall->setType(OperatorNewOrDelete->getReturnType()); + for (unsigned i = 0; i != TheCall->getNumArgs(); ++i) { + QualType ParamTy = OperatorNewOrDelete->getParamDecl(i)->getType(); + InitializedEntity Entity = + InitializedEntity::InitializeParameter(Context, ParamTy, false); + ExprResult Arg = PerformCopyInitialization( + Entity, TheCall->getArg(i)->getBeginLoc(), TheCall->getArg(i)); + if (Arg.isInvalid()) + return ExprError(); + TheCall->setArg(i, Arg.get()); + } + auto Callee = dyn_cast<ImplicitCastExpr>(TheCall->getCallee()); + assert(Callee && Callee->getCastKind() == CK_BuiltinFnToFnPtr && + "Callee expected to be implicit cast to a builtin function pointer"); + Callee->setType(OperatorNewOrDelete->getType()); + + return TheCallResult; +} + +void Sema::CheckVirtualDtorCall(CXXDestructorDecl *dtor, SourceLocation Loc, + bool IsDelete, bool CallCanBeVirtual, + bool WarnOnNonAbstractTypes, + SourceLocation DtorLoc) { + if (!dtor || dtor->isVirtual() || !CallCanBeVirtual || isUnevaluatedContext()) + return; + + // C++ [expr.delete]p3: + // In the first alternative (delete object), if the static type of the + // object to be deleted is different from its dynamic type, the static + // type shall be a base class of the dynamic type of the object to be + // deleted and the static type shall have a virtual destructor or the + // behavior is undefined. + // + const CXXRecordDecl *PointeeRD = dtor->getParent(); + // Note: a final class cannot be derived from, no issue there + if (!PointeeRD->isPolymorphic() || PointeeRD->hasAttr<FinalAttr>()) + return; + + // If the superclass is in a system header, there's nothing that can be done. + // The `delete` (where we emit the warning) can be in a system header, + // what matters for this warning is where the deleted type is defined. + if (getSourceManager().isInSystemHeader(PointeeRD->getLocation())) + return; + + QualType ClassType = dtor->getThisType()->getPointeeType(); + if (PointeeRD->isAbstract()) { + // If the class is abstract, we warn by default, because we're + // sure the code has undefined behavior. + Diag(Loc, diag::warn_delete_abstract_non_virtual_dtor) << (IsDelete ? 0 : 1) + << ClassType; + } else if (WarnOnNonAbstractTypes) { + // Otherwise, if this is not an array delete, it's a bit suspect, + // but not necessarily wrong. + Diag(Loc, diag::warn_delete_non_virtual_dtor) << (IsDelete ? 0 : 1) + << ClassType; + } + if (!IsDelete) { + std::string TypeStr; + ClassType.getAsStringInternal(TypeStr, getPrintingPolicy()); + Diag(DtorLoc, diag::note_delete_non_virtual) + << FixItHint::CreateInsertion(DtorLoc, TypeStr + "::"); + } +} + +Sema::ConditionResult Sema::ActOnConditionVariable(Decl *ConditionVar, + SourceLocation StmtLoc, + ConditionKind CK) { + ExprResult E = + CheckConditionVariable(cast<VarDecl>(ConditionVar), StmtLoc, CK); + if (E.isInvalid()) + return ConditionError(); + return ConditionResult(*this, ConditionVar, MakeFullExpr(E.get(), StmtLoc), + CK == ConditionKind::ConstexprIf); +} + +/// Check the use of the given variable as a C++ condition in an if, +/// while, do-while, or switch statement. +ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar, + SourceLocation StmtLoc, + ConditionKind CK) { + if (ConditionVar->isInvalidDecl()) + return ExprError(); + + QualType T = ConditionVar->getType(); + + // C++ [stmt.select]p2: + // The declarator shall not specify a function or an array. + if (T->isFunctionType()) + return ExprError(Diag(ConditionVar->getLocation(), + diag::err_invalid_use_of_function_type) + << ConditionVar->getSourceRange()); + else if (T->isArrayType()) + return ExprError(Diag(ConditionVar->getLocation(), + diag::err_invalid_use_of_array_type) + << ConditionVar->getSourceRange()); + + ExprResult Condition = BuildDeclRefExpr( + ConditionVar, ConditionVar->getType().getNonReferenceType(), VK_LValue, + ConditionVar->getLocation()); + + switch (CK) { + case ConditionKind::Boolean: + return CheckBooleanCondition(StmtLoc, Condition.get()); + + case ConditionKind::ConstexprIf: + return CheckBooleanCondition(StmtLoc, Condition.get(), true); + + case ConditionKind::Switch: + return CheckSwitchCondition(StmtLoc, Condition.get()); + } + + llvm_unreachable("unexpected condition kind"); +} + +/// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid. +ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr, bool IsConstexpr) { + // C++ 6.4p4: + // The value of a condition that is an initialized declaration in a statement + // other than a switch statement is the value of the declared variable + // implicitly converted to type bool. If that conversion is ill-formed, the + // program is ill-formed. + // The value of a condition that is an expression is the value of the + // expression, implicitly converted to bool. + // + // FIXME: Return this value to the caller so they don't need to recompute it. + llvm::APSInt Value(/*BitWidth*/1); + return (IsConstexpr && !CondExpr->isValueDependent()) + ? CheckConvertedConstantExpression(CondExpr, Context.BoolTy, Value, + CCEK_ConstexprIf) + : PerformContextuallyConvertToBool(CondExpr); +} + +/// Helper function to determine whether this is the (deprecated) C++ +/// conversion from a string literal to a pointer to non-const char or +/// non-const wchar_t (for narrow and wide string literals, +/// respectively). +bool +Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) { + // Look inside the implicit cast, if it exists. + if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From)) + From = Cast->getSubExpr(); + + // A string literal (2.13.4) that is not a wide string literal can + // be converted to an rvalue of type "pointer to char"; a wide + // string literal can be converted to an rvalue of type "pointer + // to wchar_t" (C++ 4.2p2). + if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens())) + if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) + if (const BuiltinType *ToPointeeType + = ToPtrType->getPointeeType()->getAs<BuiltinType>()) { + // This conversion is considered only when there is an + // explicit appropriate pointer target type (C++ 4.2p2). + if (!ToPtrType->getPointeeType().hasQualifiers()) { + switch (StrLit->getKind()) { + case StringLiteral::UTF8: + case StringLiteral::UTF16: + case StringLiteral::UTF32: + // We don't allow UTF literals to be implicitly converted + break; + case StringLiteral::Ascii: + return (ToPointeeType->getKind() == BuiltinType::Char_U || + ToPointeeType->getKind() == BuiltinType::Char_S); + case StringLiteral::Wide: + return Context.typesAreCompatible(Context.getWideCharType(), + QualType(ToPointeeType, 0)); + } + } + } + + return false; +} + +static ExprResult BuildCXXCastArgument(Sema &S, + SourceLocation CastLoc, + QualType Ty, + CastKind Kind, + CXXMethodDecl *Method, + DeclAccessPair FoundDecl, + bool HadMultipleCandidates, + Expr *From) { + switch (Kind) { + default: llvm_unreachable("Unhandled cast kind!"); + case CK_ConstructorConversion: { + CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method); + SmallVector<Expr*, 8> ConstructorArgs; + + if (S.RequireNonAbstractType(CastLoc, Ty, + diag::err_allocation_of_abstract_type)) + return ExprError(); + + if (S.CompleteConstructorCall(Constructor, From, CastLoc, ConstructorArgs)) + return ExprError(); + + S.CheckConstructorAccess(CastLoc, Constructor, FoundDecl, + InitializedEntity::InitializeTemporary(Ty)); + if (S.DiagnoseUseOfDecl(Method, CastLoc)) + return ExprError(); + + ExprResult Result = S.BuildCXXConstructExpr( + CastLoc, Ty, FoundDecl, cast<CXXConstructorDecl>(Method), + ConstructorArgs, HadMultipleCandidates, + /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, + CXXConstructExpr::CK_Complete, SourceRange()); + if (Result.isInvalid()) + return ExprError(); + + return S.MaybeBindToTemporary(Result.getAs<Expr>()); + } + + case CK_UserDefinedConversion: { + assert(!From->getType()->isPointerType() && "Arg can't have pointer type!"); + + S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl); + if (S.DiagnoseUseOfDecl(Method, CastLoc)) + return ExprError(); + + // Create an implicit call expr that calls it. + CXXConversionDecl *Conv = cast<CXXConversionDecl>(Method); + ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv, + HadMultipleCandidates); + if (Result.isInvalid()) + return ExprError(); + // Record usage of conversion in an implicit cast. + Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(), + CK_UserDefinedConversion, Result.get(), + nullptr, Result.get()->getValueKind()); + + return S.MaybeBindToTemporary(Result.get()); + } + } +} + +/// PerformImplicitConversion - Perform an implicit conversion of the +/// expression From to the type ToType using the pre-computed implicit +/// conversion sequence ICS. Returns the converted +/// expression. Action is the kind of conversion we're performing, +/// used in the error message. +ExprResult +Sema::PerformImplicitConversion(Expr *From, QualType ToType, + const ImplicitConversionSequence &ICS, + AssignmentAction Action, + CheckedConversionKind CCK) { + // C++ [over.match.oper]p7: [...] operands of class type are converted [...] + if (CCK == CCK_ForBuiltinOverloadedOp && !From->getType()->isRecordType()) + return From; + + switch (ICS.getKind()) { + case ImplicitConversionSequence::StandardConversion: { + ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard, + Action, CCK); + if (Res.isInvalid()) + return ExprError(); + From = Res.get(); + break; + } + + case ImplicitConversionSequence::UserDefinedConversion: { + + FunctionDecl *FD = ICS.UserDefined.ConversionFunction; + CastKind CastKind; + QualType BeforeToType; + assert(FD && "no conversion function for user-defined conversion seq"); + if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) { + CastKind = CK_UserDefinedConversion; + + // If the user-defined conversion is specified by a conversion function, + // the initial standard conversion sequence converts the source type to + // the implicit object parameter of the conversion function. + BeforeToType = Context.getTagDeclType(Conv->getParent()); + } else { + const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD); + CastKind = CK_ConstructorConversion; + // Do no conversion if dealing with ... for the first conversion. + if (!ICS.UserDefined.EllipsisConversion) { + // If the user-defined conversion is specified by a constructor, the + // initial standard conversion sequence converts the source type to + // the type required by the argument of the constructor + BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType(); + } + } + // Watch out for ellipsis conversion. + if (!ICS.UserDefined.EllipsisConversion) { + ExprResult Res = + PerformImplicitConversion(From, BeforeToType, + ICS.UserDefined.Before, AA_Converting, + CCK); + if (Res.isInvalid()) + return ExprError(); + From = Res.get(); + } + + ExprResult CastArg = BuildCXXCastArgument( + *this, From->getBeginLoc(), ToType.getNonReferenceType(), CastKind, + cast<CXXMethodDecl>(FD), ICS.UserDefined.FoundConversionFunction, + ICS.UserDefined.HadMultipleCandidates, From); + + if (CastArg.isInvalid()) + return ExprError(); + + From = CastArg.get(); + + // C++ [over.match.oper]p7: + // [...] the second standard conversion sequence of a user-defined + // conversion sequence is not applied. + if (CCK == CCK_ForBuiltinOverloadedOp) + return From; + + return PerformImplicitConversion(From, ToType, ICS.UserDefined.After, + AA_Converting, CCK); + } + + case ImplicitConversionSequence::AmbiguousConversion: + ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(), + PDiag(diag::err_typecheck_ambiguous_condition) + << From->getSourceRange()); + return ExprError(); + + case ImplicitConversionSequence::EllipsisConversion: + llvm_unreachable("Cannot perform an ellipsis conversion"); + + case ImplicitConversionSequence::BadConversion: + bool Diagnosed = + DiagnoseAssignmentResult(Incompatible, From->getExprLoc(), ToType, + From->getType(), From, Action); + assert(Diagnosed && "failed to diagnose bad conversion"); (void)Diagnosed; + return ExprError(); + } + + // Everything went well. + return From; +} + +/// PerformImplicitConversion - Perform an implicit conversion of the +/// expression From to the type ToType by following the standard +/// conversion sequence SCS. Returns the converted +/// expression. Flavor is the context in which we're performing this +/// conversion, for use in error messages. +ExprResult +Sema::PerformImplicitConversion(Expr *From, QualType ToType, + const StandardConversionSequence& SCS, + AssignmentAction Action, + CheckedConversionKind CCK) { + bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast); + + // Overall FIXME: we are recomputing too many types here and doing far too + // much extra work. What this means is that we need to keep track of more + // information that is computed when we try the implicit conversion initially, + // so that we don't need to recompute anything here. + QualType FromType = From->getType(); + + if (SCS.CopyConstructor) { + // FIXME: When can ToType be a reference type? + assert(!ToType->isReferenceType()); + if (SCS.Second == ICK_Derived_To_Base) { + SmallVector<Expr*, 8> ConstructorArgs; + if (CompleteConstructorCall(cast<CXXConstructorDecl>(SCS.CopyConstructor), + From, /*FIXME:ConstructLoc*/SourceLocation(), + ConstructorArgs)) + return ExprError(); + return BuildCXXConstructExpr( + /*FIXME:ConstructLoc*/ SourceLocation(), ToType, + SCS.FoundCopyConstructor, SCS.CopyConstructor, + ConstructorArgs, /*HadMultipleCandidates*/ false, + /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, + CXXConstructExpr::CK_Complete, SourceRange()); + } + return BuildCXXConstructExpr( + /*FIXME:ConstructLoc*/ SourceLocation(), ToType, + SCS.FoundCopyConstructor, SCS.CopyConstructor, + From, /*HadMultipleCandidates*/ false, + /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, + CXXConstructExpr::CK_Complete, SourceRange()); + } + + // Resolve overloaded function references. + if (Context.hasSameType(FromType, Context.OverloadTy)) { + DeclAccessPair Found; + FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, + true, Found); + if (!Fn) + return ExprError(); + + if (DiagnoseUseOfDecl(Fn, From->getBeginLoc())) + return ExprError(); + + From = FixOverloadedFunctionReference(From, Found, Fn); + FromType = From->getType(); + } + + // If we're converting to an atomic type, first convert to the corresponding + // non-atomic type. + QualType ToAtomicType; + if (const AtomicType *ToAtomic = ToType->getAs<AtomicType>()) { + ToAtomicType = ToType; + ToType = ToAtomic->getValueType(); + } + + QualType InitialFromType = FromType; + // Perform the first implicit conversion. + switch (SCS.First) { + case ICK_Identity: + if (const AtomicType *FromAtomic = FromType->getAs<AtomicType>()) { + FromType = FromAtomic->getValueType().getUnqualifiedType(); + From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic, + From, /*BasePath=*/nullptr, VK_RValue); + } + break; + + case ICK_Lvalue_To_Rvalue: { + assert(From->getObjectKind() != OK_ObjCProperty); + ExprResult FromRes = DefaultLvalueConversion(From); + assert(!FromRes.isInvalid() && "Can't perform deduced conversion?!"); + From = FromRes.get(); + FromType = From->getType(); + break; + } + + case ICK_Array_To_Pointer: + FromType = Context.getArrayDecayedType(FromType); + From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + break; + + case ICK_Function_To_Pointer: + FromType = Context.getPointerType(FromType); + From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + break; + + default: + llvm_unreachable("Improper first standard conversion"); + } + + // Perform the second implicit conversion + switch (SCS.Second) { + case ICK_Identity: + // C++ [except.spec]p5: + // [For] assignment to and initialization of pointers to functions, + // pointers to member functions, and references to functions: the + // target entity shall allow at least the exceptions allowed by the + // source value in the assignment or initialization. + switch (Action) { + case AA_Assigning: + case AA_Initializing: + // Note, function argument passing and returning are initialization. + case AA_Passing: + case AA_Returning: + case AA_Sending: + case AA_Passing_CFAudited: + if (CheckExceptionSpecCompatibility(From, ToType)) + return ExprError(); + break; + + case AA_Casting: + case AA_Converting: + // Casts and implicit conversions are not initialization, so are not + // checked for exception specification mismatches. + break; + } + // Nothing else to do. + break; + + case ICK_Integral_Promotion: + case ICK_Integral_Conversion: + if (ToType->isBooleanType()) { + assert(FromType->castAs<EnumType>()->getDecl()->isFixed() && + SCS.Second == ICK_Integral_Promotion && + "only enums with fixed underlying type can promote to bool"); + From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + } else { + From = ImpCastExprToType(From, ToType, CK_IntegralCast, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + } + break; + + case ICK_Floating_Promotion: + case ICK_Floating_Conversion: + From = ImpCastExprToType(From, ToType, CK_FloatingCast, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + break; + + case ICK_Complex_Promotion: + case ICK_Complex_Conversion: { + QualType FromEl = From->getType()->castAs<ComplexType>()->getElementType(); + QualType ToEl = ToType->castAs<ComplexType>()->getElementType(); + CastKind CK; + if (FromEl->isRealFloatingType()) { + if (ToEl->isRealFloatingType()) + CK = CK_FloatingComplexCast; + else + CK = CK_FloatingComplexToIntegralComplex; + } else if (ToEl->isRealFloatingType()) { + CK = CK_IntegralComplexToFloatingComplex; + } else { + CK = CK_IntegralComplexCast; + } + From = ImpCastExprToType(From, ToType, CK, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + break; + } + + case ICK_Floating_Integral: + if (ToType->isRealFloatingType()) + From = ImpCastExprToType(From, ToType, CK_IntegralToFloating, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + else + From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + break; + + case ICK_Compatible_Conversion: + From = ImpCastExprToType(From, ToType, CK_NoOp, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + break; + + case ICK_Writeback_Conversion: + case ICK_Pointer_Conversion: { + if (SCS.IncompatibleObjC && Action != AA_Casting) { + // Diagnose incompatible Objective-C conversions + if (Action == AA_Initializing || Action == AA_Assigning) + Diag(From->getBeginLoc(), + diag::ext_typecheck_convert_incompatible_pointer) + << ToType << From->getType() << Action << From->getSourceRange() + << 0; + else + Diag(From->getBeginLoc(), + diag::ext_typecheck_convert_incompatible_pointer) + << From->getType() << ToType << Action << From->getSourceRange() + << 0; + + if (From->getType()->isObjCObjectPointerType() && + ToType->isObjCObjectPointerType()) + EmitRelatedResultTypeNote(From); + } else if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers() && + !CheckObjCARCUnavailableWeakConversion(ToType, + From->getType())) { + if (Action == AA_Initializing) + Diag(From->getBeginLoc(), diag::err_arc_weak_unavailable_assign); + else + Diag(From->getBeginLoc(), diag::err_arc_convesion_of_weak_unavailable) + << (Action == AA_Casting) << From->getType() << ToType + << From->getSourceRange(); + } + + CastKind Kind; + CXXCastPath BasePath; + if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle)) + return ExprError(); + + // Make sure we extend blocks if necessary. + // FIXME: doing this here is really ugly. + if (Kind == CK_BlockPointerToObjCPointerCast) { + ExprResult E = From; + (void) PrepareCastToObjCObjectPointer(E); + From = E.get(); + } + if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers()) + CheckObjCConversion(SourceRange(), ToType, From, CCK); + From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK) + .get(); + break; + } + + case ICK_Pointer_Member: { + CastKind Kind; + CXXCastPath BasePath; + if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle)) + return ExprError(); + if (CheckExceptionSpecCompatibility(From, ToType)) + return ExprError(); + + // We may not have been able to figure out what this member pointer resolved + // to up until this exact point. Attempt to lock-in it's inheritance model. + if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { + (void)isCompleteType(From->getExprLoc(), From->getType()); + (void)isCompleteType(From->getExprLoc(), ToType); + } + + From = ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath, CCK) + .get(); + break; + } + + case ICK_Boolean_Conversion: + // Perform half-to-boolean conversion via float. + if (From->getType()->isHalfType()) { + From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get(); + FromType = Context.FloatTy; + } + + From = ImpCastExprToType(From, Context.BoolTy, + ScalarTypeToBooleanCastKind(FromType), + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + break; + + case ICK_Derived_To_Base: { + CXXCastPath BasePath; + if (CheckDerivedToBaseConversion( + From->getType(), ToType.getNonReferenceType(), From->getBeginLoc(), + From->getSourceRange(), &BasePath, CStyle)) + return ExprError(); + + From = ImpCastExprToType(From, ToType.getNonReferenceType(), + CK_DerivedToBase, From->getValueKind(), + &BasePath, CCK).get(); + break; + } + + case ICK_Vector_Conversion: + From = ImpCastExprToType(From, ToType, CK_BitCast, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + break; + + case ICK_Vector_Splat: { + // Vector splat from any arithmetic type to a vector. + Expr *Elem = prepareVectorSplat(ToType, From).get(); + From = ImpCastExprToType(Elem, ToType, CK_VectorSplat, VK_RValue, + /*BasePath=*/nullptr, CCK).get(); + break; + } + + case ICK_Complex_Real: + // Case 1. x -> _Complex y + if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) { + QualType ElType = ToComplex->getElementType(); + bool isFloatingComplex = ElType->isRealFloatingType(); + + // x -> y + if (Context.hasSameUnqualifiedType(ElType, From->getType())) { + // do nothing + } else if (From->getType()->isRealFloatingType()) { + From = ImpCastExprToType(From, ElType, + isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get(); + } else { + assert(From->getType()->isIntegerType()); + From = ImpCastExprToType(From, ElType, + isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get(); + } + // y -> _Complex y + From = ImpCastExprToType(From, ToType, + isFloatingComplex ? CK_FloatingRealToComplex + : CK_IntegralRealToComplex).get(); + + // Case 2. _Complex x -> y + } else { + const ComplexType *FromComplex = From->getType()->getAs<ComplexType>(); + assert(FromComplex); + + QualType ElType = FromComplex->getElementType(); + bool isFloatingComplex = ElType->isRealFloatingType(); + + // _Complex x -> x + From = ImpCastExprToType(From, ElType, + isFloatingComplex ? CK_FloatingComplexToReal + : CK_IntegralComplexToReal, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + + // x -> y + if (Context.hasSameUnqualifiedType(ElType, ToType)) { + // do nothing + } else if (ToType->isRealFloatingType()) { + From = ImpCastExprToType(From, ToType, + isFloatingComplex ? CK_FloatingCast : CK_IntegralToFloating, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + } else { + assert(ToType->isIntegerType()); + From = ImpCastExprToType(From, ToType, + isFloatingComplex ? CK_FloatingToIntegral : CK_IntegralCast, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + } + } + break; + + case ICK_Block_Pointer_Conversion: { + LangAS AddrSpaceL = + ToType->castAs<BlockPointerType>()->getPointeeType().getAddressSpace(); + LangAS AddrSpaceR = + FromType->castAs<BlockPointerType>()->getPointeeType().getAddressSpace(); + assert(Qualifiers::isAddressSpaceSupersetOf(AddrSpaceL, AddrSpaceR) && + "Invalid cast"); + CastKind Kind = + AddrSpaceL != AddrSpaceR ? CK_AddressSpaceConversion : CK_BitCast; + From = ImpCastExprToType(From, ToType.getUnqualifiedType(), Kind, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + break; + } + + case ICK_TransparentUnionConversion: { + ExprResult FromRes = From; + Sema::AssignConvertType ConvTy = + CheckTransparentUnionArgumentConstraints(ToType, FromRes); + if (FromRes.isInvalid()) + return ExprError(); + From = FromRes.get(); + assert ((ConvTy == Sema::Compatible) && + "Improper transparent union conversion"); + (void)ConvTy; + break; + } + + case ICK_Zero_Event_Conversion: + case ICK_Zero_Queue_Conversion: + From = ImpCastExprToType(From, ToType, + CK_ZeroToOCLOpaqueType, + From->getValueKind()).get(); + break; + + case ICK_Lvalue_To_Rvalue: + case ICK_Array_To_Pointer: + case ICK_Function_To_Pointer: + case ICK_Function_Conversion: + case ICK_Qualification: + case ICK_Num_Conversion_Kinds: + case ICK_C_Only_Conversion: + case ICK_Incompatible_Pointer_Conversion: + llvm_unreachable("Improper second standard conversion"); + } + + switch (SCS.Third) { + case ICK_Identity: + // Nothing to do. + break; + + case ICK_Function_Conversion: + // If both sides are functions (or pointers/references to them), there could + // be incompatible exception declarations. + if (CheckExceptionSpecCompatibility(From, ToType)) + return ExprError(); + + From = ImpCastExprToType(From, ToType, CK_NoOp, + VK_RValue, /*BasePath=*/nullptr, CCK).get(); + break; + + case ICK_Qualification: { + // The qualification keeps the category of the inner expression, unless the + // target type isn't a reference. + ExprValueKind VK = + ToType->isReferenceType() ? From->getValueKind() : VK_RValue; + + CastKind CK = CK_NoOp; + + if (ToType->isReferenceType() && + ToType->getPointeeType().getAddressSpace() != + From->getType().getAddressSpace()) + CK = CK_AddressSpaceConversion; + + if (ToType->isPointerType() && + ToType->getPointeeType().getAddressSpace() != + From->getType()->getPointeeType().getAddressSpace()) + CK = CK_AddressSpaceConversion; + + From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context), CK, VK, + /*BasePath=*/nullptr, CCK) + .get(); + + if (SCS.DeprecatedStringLiteralToCharPtr && + !getLangOpts().WritableStrings) { + Diag(From->getBeginLoc(), + getLangOpts().CPlusPlus11 + ? diag::ext_deprecated_string_literal_conversion + : diag::warn_deprecated_string_literal_conversion) + << ToType.getNonReferenceType(); + } + + break; + } + + default: + llvm_unreachable("Improper third standard conversion"); + } + + // If this conversion sequence involved a scalar -> atomic conversion, perform + // that conversion now. + if (!ToAtomicType.isNull()) { + assert(Context.hasSameType( + ToAtomicType->castAs<AtomicType>()->getValueType(), From->getType())); + From = ImpCastExprToType(From, ToAtomicType, CK_NonAtomicToAtomic, + VK_RValue, nullptr, CCK).get(); + } + + // If this conversion sequence succeeded and involved implicitly converting a + // _Nullable type to a _Nonnull one, complain. + if (!isCast(CCK)) + diagnoseNullableToNonnullConversion(ToType, InitialFromType, + From->getBeginLoc()); + + return From; +} + +/// Check the completeness of a type in a unary type trait. +/// +/// If the particular type trait requires a complete type, tries to complete +/// it. If completing the type fails, a diagnostic is emitted and false +/// returned. If completing the type succeeds or no completion was required, +/// returns true. +static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT, + SourceLocation Loc, + QualType ArgTy) { + // C++0x [meta.unary.prop]p3: + // For all of the class templates X declared in this Clause, instantiating + // that template with a template argument that is a class template + // specialization may result in the implicit instantiation of the template + // argument if and only if the semantics of X require that the argument + // must be a complete type. + // We apply this rule to all the type trait expressions used to implement + // these class templates. We also try to follow any GCC documented behavior + // in these expressions to ensure portability of standard libraries. + switch (UTT) { + default: llvm_unreachable("not a UTT"); + // is_complete_type somewhat obviously cannot require a complete type. + case UTT_IsCompleteType: + // Fall-through + + // These traits are modeled on the type predicates in C++0x + // [meta.unary.cat] and [meta.unary.comp]. They are not specified as + // requiring a complete type, as whether or not they return true cannot be + // impacted by the completeness of the type. + case UTT_IsVoid: + case UTT_IsIntegral: + case UTT_IsFloatingPoint: + case UTT_IsArray: + case UTT_IsPointer: + case UTT_IsLvalueReference: + case UTT_IsRvalueReference: + case UTT_IsMemberFunctionPointer: + case UTT_IsMemberObjectPointer: + case UTT_IsEnum: + case UTT_IsUnion: + case UTT_IsClass: + case UTT_IsFunction: + case UTT_IsReference: + case UTT_IsArithmetic: + case UTT_IsFundamental: + case UTT_IsObject: + case UTT_IsScalar: + case UTT_IsCompound: + case UTT_IsMemberPointer: + // Fall-through + + // These traits are modeled on type predicates in C++0x [meta.unary.prop] + // which requires some of its traits to have the complete type. However, + // the completeness of the type cannot impact these traits' semantics, and + // so they don't require it. This matches the comments on these traits in + // Table 49. + case UTT_IsConst: + case UTT_IsVolatile: + case UTT_IsSigned: + case UTT_IsUnsigned: + + // This type trait always returns false, checking the type is moot. + case UTT_IsInterfaceClass: + return true; + + // C++14 [meta.unary.prop]: + // If T is a non-union class type, T shall be a complete type. + case UTT_IsEmpty: + case UTT_IsPolymorphic: + case UTT_IsAbstract: + if (const auto *RD = ArgTy->getAsCXXRecordDecl()) + if (!RD->isUnion()) + return !S.RequireCompleteType( + Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr); + return true; + + // C++14 [meta.unary.prop]: + // If T is a class type, T shall be a complete type. + case UTT_IsFinal: + case UTT_IsSealed: + if (ArgTy->getAsCXXRecordDecl()) + return !S.RequireCompleteType( + Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr); + return true; + + // C++1z [meta.unary.prop]: + // remove_all_extents_t<T> shall be a complete type or cv void. + case UTT_IsAggregate: + case UTT_IsTrivial: + case UTT_IsTriviallyCopyable: + case UTT_IsStandardLayout: + case UTT_IsPOD: + case UTT_IsLiteral: + // Per the GCC type traits documentation, T shall be a complete type, cv void, + // or an array of unknown bound. But GCC actually imposes the same constraints + // as above. + case UTT_HasNothrowAssign: + case UTT_HasNothrowMoveAssign: + case UTT_HasNothrowConstructor: + case UTT_HasNothrowCopy: + case UTT_HasTrivialAssign: + case UTT_HasTrivialMoveAssign: + case UTT_HasTrivialDefaultConstructor: + case UTT_HasTrivialMoveConstructor: + case UTT_HasTrivialCopy: + case UTT_HasTrivialDestructor: + case UTT_HasVirtualDestructor: + ArgTy = QualType(ArgTy->getBaseElementTypeUnsafe(), 0); + LLVM_FALLTHROUGH; + + // C++1z [meta.unary.prop]: + // T shall be a complete type, cv void, or an array of unknown bound. + case UTT_IsDestructible: + case UTT_IsNothrowDestructible: + case UTT_IsTriviallyDestructible: + case UTT_HasUniqueObjectRepresentations: + if (ArgTy->isIncompleteArrayType() || ArgTy->isVoidType()) + return true; + + return !S.RequireCompleteType( + Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr); + } +} + +static bool HasNoThrowOperator(const RecordType *RT, OverloadedOperatorKind Op, + Sema &Self, SourceLocation KeyLoc, ASTContext &C, + bool (CXXRecordDecl::*HasTrivial)() const, + bool (CXXRecordDecl::*HasNonTrivial)() const, + bool (CXXMethodDecl::*IsDesiredOp)() const) +{ + CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); + if ((RD->*HasTrivial)() && !(RD->*HasNonTrivial)()) + return true; + + DeclarationName Name = C.DeclarationNames.getCXXOperatorName(Op); + DeclarationNameInfo NameInfo(Name, KeyLoc); + LookupResult Res(Self, NameInfo, Sema::LookupOrdinaryName); + if (Self.LookupQualifiedName(Res, RD)) { + bool FoundOperator = false; + Res.suppressDiagnostics(); + for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end(); + Op != OpEnd; ++Op) { + if (isa<FunctionTemplateDecl>(*Op)) + continue; + + CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op); + if((Operator->*IsDesiredOp)()) { + FoundOperator = true; + const FunctionProtoType *CPT = + Operator->getType()->getAs<FunctionProtoType>(); + CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); + if (!CPT || !CPT->isNothrow()) + return false; + } + } + return FoundOperator; + } + return false; +} + +static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT, + SourceLocation KeyLoc, QualType T) { + assert(!T->isDependentType() && "Cannot evaluate traits of dependent type"); + + ASTContext &C = Self.Context; + switch(UTT) { + default: llvm_unreachable("not a UTT"); + // Type trait expressions corresponding to the primary type category + // predicates in C++0x [meta.unary.cat]. + case UTT_IsVoid: + return T->isVoidType(); + case UTT_IsIntegral: + return T->isIntegralType(C); + case UTT_IsFloatingPoint: + return T->isFloatingType(); + case UTT_IsArray: + return T->isArrayType(); + case UTT_IsPointer: + return T->isPointerType(); + case UTT_IsLvalueReference: + return T->isLValueReferenceType(); + case UTT_IsRvalueReference: + return T->isRValueReferenceType(); + case UTT_IsMemberFunctionPointer: + return T->isMemberFunctionPointerType(); + case UTT_IsMemberObjectPointer: + return T->isMemberDataPointerType(); + case UTT_IsEnum: + return T->isEnumeralType(); + case UTT_IsUnion: + return T->isUnionType(); + case UTT_IsClass: + return T->isClassType() || T->isStructureType() || T->isInterfaceType(); + case UTT_IsFunction: + return T->isFunctionType(); + + // Type trait expressions which correspond to the convenient composition + // predicates in C++0x [meta.unary.comp]. + case UTT_IsReference: + return T->isReferenceType(); + case UTT_IsArithmetic: + return T->isArithmeticType() && !T->isEnumeralType(); + case UTT_IsFundamental: + return T->isFundamentalType(); + case UTT_IsObject: + return T->isObjectType(); + case UTT_IsScalar: + // Note: semantic analysis depends on Objective-C lifetime types to be + // considered scalar types. However, such types do not actually behave + // like scalar types at run time (since they may require retain/release + // operations), so we report them as non-scalar. + if (T->isObjCLifetimeType()) { + switch (T.getObjCLifetime()) { + case Qualifiers::OCL_None: + case Qualifiers::OCL_ExplicitNone: + return true; + + case Qualifiers::OCL_Strong: + case Qualifiers::OCL_Weak: + case Qualifiers::OCL_Autoreleasing: + return false; + } + } + + return T->isScalarType(); + case UTT_IsCompound: + return T->isCompoundType(); + case UTT_IsMemberPointer: + return T->isMemberPointerType(); + + // Type trait expressions which correspond to the type property predicates + // in C++0x [meta.unary.prop]. + case UTT_IsConst: + return T.isConstQualified(); + case UTT_IsVolatile: + return T.isVolatileQualified(); + case UTT_IsTrivial: + return T.isTrivialType(C); + case UTT_IsTriviallyCopyable: + return T.isTriviallyCopyableType(C); + case UTT_IsStandardLayout: + return T->isStandardLayoutType(); + case UTT_IsPOD: + return T.isPODType(C); + case UTT_IsLiteral: + return T->isLiteralType(C); + case UTT_IsEmpty: + if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) + return !RD->isUnion() && RD->isEmpty(); + return false; + case UTT_IsPolymorphic: + if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) + return !RD->isUnion() && RD->isPolymorphic(); + return false; + case UTT_IsAbstract: + if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) + return !RD->isUnion() && RD->isAbstract(); + return false; + case UTT_IsAggregate: + // Report vector extensions and complex types as aggregates because they + // support aggregate initialization. GCC mirrors this behavior for vectors + // but not _Complex. + return T->isAggregateType() || T->isVectorType() || T->isExtVectorType() || + T->isAnyComplexType(); + // __is_interface_class only returns true when CL is invoked in /CLR mode and + // even then only when it is used with the 'interface struct ...' syntax + // Clang doesn't support /CLR which makes this type trait moot. + case UTT_IsInterfaceClass: + return false; + case UTT_IsFinal: + case UTT_IsSealed: + if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) + return RD->hasAttr<FinalAttr>(); + return false; + case UTT_IsSigned: + // Enum types should always return false. + // Floating points should always return true. + return !T->isEnumeralType() && (T->isFloatingType() || T->isSignedIntegerType()); + case UTT_IsUnsigned: + return T->isUnsignedIntegerType(); + + // Type trait expressions which query classes regarding their construction, + // destruction, and copying. Rather than being based directly on the + // related type predicates in the standard, they are specified by both + // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those + // specifications. + // + // 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html + // 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index + // + // Note that these builtins do not behave as documented in g++: if a class + // has both a trivial and a non-trivial special member of a particular kind, + // they return false! For now, we emulate this behavior. + // FIXME: This appears to be a g++ bug: more complex cases reveal that it + // does not correctly compute triviality in the presence of multiple special + // members of the same kind. Revisit this once the g++ bug is fixed. + case UTT_HasTrivialDefaultConstructor: + // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: + // If __is_pod (type) is true then the trait is true, else if type is + // a cv class or union type (or array thereof) with a trivial default + // constructor ([class.ctor]) then the trait is true, else it is false. + if (T.isPODType(C)) + return true; + if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) + return RD->hasTrivialDefaultConstructor() && + !RD->hasNonTrivialDefaultConstructor(); + return false; + case UTT_HasTrivialMoveConstructor: + // This trait is implemented by MSVC 2012 and needed to parse the + // standard library headers. Specifically this is used as the logic + // behind std::is_trivially_move_constructible (20.9.4.3). + if (T.isPODType(C)) + return true; + if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) + return RD->hasTrivialMoveConstructor() && !RD->hasNonTrivialMoveConstructor(); + return false; + case UTT_HasTrivialCopy: + // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: + // If __is_pod (type) is true or type is a reference type then + // the trait is true, else if type is a cv class or union type + // with a trivial copy constructor ([class.copy]) then the trait + // is true, else it is false. + if (T.isPODType(C) || T->isReferenceType()) + return true; + if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) + return RD->hasTrivialCopyConstructor() && + !RD->hasNonTrivialCopyConstructor(); + return false; + case UTT_HasTrivialMoveAssign: + // This trait is implemented by MSVC 2012 and needed to parse the + // standard library headers. Specifically it is used as the logic + // behind std::is_trivially_move_assignable (20.9.4.3) + if (T.isPODType(C)) + return true; + if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) + return RD->hasTrivialMoveAssignment() && !RD->hasNonTrivialMoveAssignment(); + return false; + case UTT_HasTrivialAssign: + // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: + // If type is const qualified or is a reference type then the + // trait is false. Otherwise if __is_pod (type) is true then the + // trait is true, else if type is a cv class or union type with + // a trivial copy assignment ([class.copy]) then the trait is + // true, else it is false. + // Note: the const and reference restrictions are interesting, + // given that const and reference members don't prevent a class + // from having a trivial copy assignment operator (but do cause + // errors if the copy assignment operator is actually used, q.v. + // [class.copy]p12). + + if (T.isConstQualified()) + return false; + if (T.isPODType(C)) + return true; + if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) + return RD->hasTrivialCopyAssignment() && + !RD->hasNonTrivialCopyAssignment(); + return false; + case UTT_IsDestructible: + case UTT_IsTriviallyDestructible: + case UTT_IsNothrowDestructible: + // C++14 [meta.unary.prop]: + // For reference types, is_destructible<T>::value is true. + if (T->isReferenceType()) + return true; + + // Objective-C++ ARC: autorelease types don't require destruction. + if (T->isObjCLifetimeType() && + T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing) + return true; + + // C++14 [meta.unary.prop]: + // For incomplete types and function types, is_destructible<T>::value is + // false. + if (T->isIncompleteType() || T->isFunctionType()) + return false; + + // A type that requires destruction (via a non-trivial destructor or ARC + // lifetime semantics) is not trivially-destructible. + if (UTT == UTT_IsTriviallyDestructible && T.isDestructedType()) + return false; + + // C++14 [meta.unary.prop]: + // For object types and given U equal to remove_all_extents_t<T>, if the + // expression std::declval<U&>().~U() is well-formed when treated as an + // unevaluated operand (Clause 5), then is_destructible<T>::value is true + if (auto *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) { + CXXDestructorDecl *Destructor = Self.LookupDestructor(RD); + if (!Destructor) + return false; + // C++14 [dcl.fct.def.delete]p2: + // A program that refers to a deleted function implicitly or + // explicitly, other than to declare it, is ill-formed. + if (Destructor->isDeleted()) + return false; + if (C.getLangOpts().AccessControl && Destructor->getAccess() != AS_public) + return false; + if (UTT == UTT_IsNothrowDestructible) { + const FunctionProtoType *CPT = + Destructor->getType()->getAs<FunctionProtoType>(); + CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); + if (!CPT || !CPT->isNothrow()) + return false; + } + } + return true; + + case UTT_HasTrivialDestructor: + // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html + // If __is_pod (type) is true or type is a reference type + // then the trait is true, else if type is a cv class or union + // type (or array thereof) with a trivial destructor + // ([class.dtor]) then the trait is true, else it is + // false. + if (T.isPODType(C) || T->isReferenceType()) + return true; + + // Objective-C++ ARC: autorelease types don't require destruction. + if (T->isObjCLifetimeType() && + T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing) + return true; + + if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) + return RD->hasTrivialDestructor(); + return false; + // TODO: Propagate nothrowness for implicitly declared special members. + case UTT_HasNothrowAssign: + // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: + // If type is const qualified or is a reference type then the + // trait is false. Otherwise if __has_trivial_assign (type) + // is true then the trait is true, else if type is a cv class + // or union type with copy assignment operators that are known + // not to throw an exception then the trait is true, else it is + // false. + if (C.getBaseElementType(T).isConstQualified()) + return false; + if (T->isReferenceType()) + return false; + if (T.isPODType(C) || T->isObjCLifetimeType()) + return true; + + if (const RecordType *RT = T->getAs<RecordType>()) + return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C, + &CXXRecordDecl::hasTrivialCopyAssignment, + &CXXRecordDecl::hasNonTrivialCopyAssignment, + &CXXMethodDecl::isCopyAssignmentOperator); + return false; + case UTT_HasNothrowMoveAssign: + // This trait is implemented by MSVC 2012 and needed to parse the + // standard library headers. Specifically this is used as the logic + // behind std::is_nothrow_move_assignable (20.9.4.3). + if (T.isPODType(C)) + return true; + + if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>()) + return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C, + &CXXRecordDecl::hasTrivialMoveAssignment, + &CXXRecordDecl::hasNonTrivialMoveAssignment, + &CXXMethodDecl::isMoveAssignmentOperator); + return false; + case UTT_HasNothrowCopy: + // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: + // If __has_trivial_copy (type) is true then the trait is true, else + // if type is a cv class or union type with copy constructors that are + // known not to throw an exception then the trait is true, else it is + // false. + if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType()) + return true; + if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) { + if (RD->hasTrivialCopyConstructor() && + !RD->hasNonTrivialCopyConstructor()) + return true; + + bool FoundConstructor = false; + unsigned FoundTQs; + for (const auto *ND : Self.LookupConstructors(RD)) { + // A template constructor is never a copy constructor. + // FIXME: However, it may actually be selected at the actual overload + // resolution point. + if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl())) + continue; + // UsingDecl itself is not a constructor + if (isa<UsingDecl>(ND)) + continue; + auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl()); + if (Constructor->isCopyConstructor(FoundTQs)) { + FoundConstructor = true; + const FunctionProtoType *CPT + = Constructor->getType()->getAs<FunctionProtoType>(); + CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); + if (!CPT) + return false; + // TODO: check whether evaluating default arguments can throw. + // For now, we'll be conservative and assume that they can throw. + if (!CPT->isNothrow() || CPT->getNumParams() > 1) + return false; + } + } + + return FoundConstructor; + } + return false; + case UTT_HasNothrowConstructor: + // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html + // If __has_trivial_constructor (type) is true then the trait is + // true, else if type is a cv class or union type (or array + // thereof) with a default constructor that is known not to + // throw an exception then the trait is true, else it is false. + if (T.isPODType(C) || T->isObjCLifetimeType()) + return true; + if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) { + if (RD->hasTrivialDefaultConstructor() && + !RD->hasNonTrivialDefaultConstructor()) + return true; + + bool FoundConstructor = false; + for (const auto *ND : Self.LookupConstructors(RD)) { + // FIXME: In C++0x, a constructor template can be a default constructor. + if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl())) + continue; + // UsingDecl itself is not a constructor + if (isa<UsingDecl>(ND)) + continue; + auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl()); + if (Constructor->isDefaultConstructor()) { + FoundConstructor = true; + const FunctionProtoType *CPT + = Constructor->getType()->getAs<FunctionProtoType>(); + CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); + if (!CPT) + return false; + // FIXME: check whether evaluating default arguments can throw. + // For now, we'll be conservative and assume that they can throw. + if (!CPT->isNothrow() || CPT->getNumParams() > 0) + return false; + } + } + return FoundConstructor; + } + return false; + case UTT_HasVirtualDestructor: + // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: + // If type is a class type with a virtual destructor ([class.dtor]) + // then the trait is true, else it is false. + if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) + if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD)) + return Destructor->isVirtual(); + return false; + + // These type trait expressions are modeled on the specifications for the + // Embarcadero C++0x type trait functions: + // http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index + case UTT_IsCompleteType: + // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_): + // Returns True if and only if T is a complete type at the point of the + // function call. + return !T->isIncompleteType(); + case UTT_HasUniqueObjectRepresentations: + return C.hasUniqueObjectRepresentations(T); + } +} + +static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT, + QualType RhsT, SourceLocation KeyLoc); + +static bool evaluateTypeTrait(Sema &S, TypeTrait Kind, SourceLocation KWLoc, + ArrayRef<TypeSourceInfo *> Args, + SourceLocation RParenLoc) { + if (Kind <= UTT_Last) + return EvaluateUnaryTypeTrait(S, Kind, KWLoc, Args[0]->getType()); + + // Evaluate BTT_ReferenceBindsToTemporary alongside the IsConstructible + // traits to avoid duplication. + if (Kind <= BTT_Last && Kind != BTT_ReferenceBindsToTemporary) + return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(), + Args[1]->getType(), RParenLoc); + + switch (Kind) { + case clang::BTT_ReferenceBindsToTemporary: + case clang::TT_IsConstructible: + case clang::TT_IsNothrowConstructible: + case clang::TT_IsTriviallyConstructible: { + // C++11 [meta.unary.prop]: + // is_trivially_constructible is defined as: + // + // is_constructible<T, Args...>::value is true and the variable + // definition for is_constructible, as defined below, is known to call + // no operation that is not trivial. + // + // The predicate condition for a template specialization + // is_constructible<T, Args...> shall be satisfied if and only if the + // following variable definition would be well-formed for some invented + // variable t: + // + // T t(create<Args>()...); + assert(!Args.empty()); + + // Precondition: T and all types in the parameter pack Args shall be + // complete types, (possibly cv-qualified) void, or arrays of + // unknown bound. + for (const auto *TSI : Args) { + QualType ArgTy = TSI->getType(); + if (ArgTy->isVoidType() || ArgTy->isIncompleteArrayType()) + continue; + + if (S.RequireCompleteType(KWLoc, ArgTy, + diag::err_incomplete_type_used_in_type_trait_expr)) + return false; + } + + // Make sure the first argument is not incomplete nor a function type. + QualType T = Args[0]->getType(); + if (T->isIncompleteType() || T->isFunctionType()) + return false; + + // Make sure the first argument is not an abstract type. + CXXRecordDecl *RD = T->getAsCXXRecordDecl(); + if (RD && RD->isAbstract()) + return false; + + SmallVector<OpaqueValueExpr, 2> OpaqueArgExprs; + SmallVector<Expr *, 2> ArgExprs; + ArgExprs.reserve(Args.size() - 1); + for (unsigned I = 1, N = Args.size(); I != N; ++I) { + QualType ArgTy = Args[I]->getType(); + if (ArgTy->isObjectType() || ArgTy->isFunctionType()) + ArgTy = S.Context.getRValueReferenceType(ArgTy); + OpaqueArgExprs.push_back( + OpaqueValueExpr(Args[I]->getTypeLoc().getBeginLoc(), + ArgTy.getNonLValueExprType(S.Context), + Expr::getValueKindForType(ArgTy))); + } + for (Expr &E : OpaqueArgExprs) + ArgExprs.push_back(&E); + + // Perform the initialization in an unevaluated context within a SFINAE + // trap at translation unit scope. + EnterExpressionEvaluationContext Unevaluated( + S, Sema::ExpressionEvaluationContext::Unevaluated); + Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true); + Sema::ContextRAII TUContext(S, S.Context.getTranslationUnitDecl()); + InitializedEntity To(InitializedEntity::InitializeTemporary(Args[0])); + InitializationKind InitKind(InitializationKind::CreateDirect(KWLoc, KWLoc, + RParenLoc)); + InitializationSequence Init(S, To, InitKind, ArgExprs); + if (Init.Failed()) + return false; + + ExprResult Result = Init.Perform(S, To, InitKind, ArgExprs); + if (Result.isInvalid() || SFINAE.hasErrorOccurred()) + return false; + + if (Kind == clang::TT_IsConstructible) + return true; + + if (Kind == clang::BTT_ReferenceBindsToTemporary) { + if (!T->isReferenceType()) + return false; + + return !Init.isDirectReferenceBinding(); + } + + if (Kind == clang::TT_IsNothrowConstructible) + return S.canThrow(Result.get()) == CT_Cannot; + + if (Kind == clang::TT_IsTriviallyConstructible) { + // Under Objective-C ARC and Weak, if the destination has non-trivial + // Objective-C lifetime, this is a non-trivial construction. + if (T.getNonReferenceType().hasNonTrivialObjCLifetime()) + return false; + + // The initialization succeeded; now make sure there are no non-trivial + // calls. + return !Result.get()->hasNonTrivialCall(S.Context); + } + + llvm_unreachable("unhandled type trait"); + return false; + } + default: llvm_unreachable("not a TT"); + } + + return false; +} + +ExprResult Sema::BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc, + ArrayRef<TypeSourceInfo *> Args, + SourceLocation RParenLoc) { + QualType ResultType = Context.getLogicalOperationType(); + + if (Kind <= UTT_Last && !CheckUnaryTypeTraitTypeCompleteness( + *this, Kind, KWLoc, Args[0]->getType())) + return ExprError(); + + bool Dependent = false; + for (unsigned I = 0, N = Args.size(); I != N; ++I) { + if (Args[I]->getType()->isDependentType()) { + Dependent = true; + break; + } + } + + bool Result = false; + if (!Dependent) + Result = evaluateTypeTrait(*this, Kind, KWLoc, Args, RParenLoc); + + return TypeTraitExpr::Create(Context, ResultType, KWLoc, Kind, Args, + RParenLoc, Result); +} + +ExprResult Sema::ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc, + ArrayRef<ParsedType> Args, + SourceLocation RParenLoc) { + SmallVector<TypeSourceInfo *, 4> ConvertedArgs; + ConvertedArgs.reserve(Args.size()); + + for (unsigned I = 0, N = Args.size(); I != N; ++I) { + TypeSourceInfo *TInfo; + QualType T = GetTypeFromParser(Args[I], &TInfo); + if (!TInfo) + TInfo = Context.getTrivialTypeSourceInfo(T, KWLoc); + + ConvertedArgs.push_back(TInfo); + } + + return BuildTypeTrait(Kind, KWLoc, ConvertedArgs, RParenLoc); +} + +static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT, + QualType RhsT, SourceLocation KeyLoc) { + assert(!LhsT->isDependentType() && !RhsT->isDependentType() && + "Cannot evaluate traits of dependent types"); + + switch(BTT) { + case BTT_IsBaseOf: { + // C++0x [meta.rel]p2 + // Base is a base class of Derived without regard to cv-qualifiers or + // Base and Derived are not unions and name the same class type without + // regard to cv-qualifiers. + + const RecordType *lhsRecord = LhsT->getAs<RecordType>(); + const RecordType *rhsRecord = RhsT->getAs<RecordType>(); + if (!rhsRecord || !lhsRecord) { + const ObjCObjectType *LHSObjTy = LhsT->getAs<ObjCObjectType>(); + const ObjCObjectType *RHSObjTy = RhsT->getAs<ObjCObjectType>(); + if (!LHSObjTy || !RHSObjTy) + return false; + + ObjCInterfaceDecl *BaseInterface = LHSObjTy->getInterface(); + ObjCInterfaceDecl *DerivedInterface = RHSObjTy->getInterface(); + if (!BaseInterface || !DerivedInterface) + return false; + + if (Self.RequireCompleteType( + KeyLoc, RhsT, diag::err_incomplete_type_used_in_type_trait_expr)) + return false; + + return BaseInterface->isSuperClassOf(DerivedInterface); + } + + assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT) + == (lhsRecord == rhsRecord)); + + // Unions are never base classes, and never have base classes. + // It doesn't matter if they are complete or not. See PR#41843 + if (lhsRecord && lhsRecord->getDecl()->isUnion()) + return false; + if (rhsRecord && rhsRecord->getDecl()->isUnion()) + return false; + + if (lhsRecord == rhsRecord) + return true; + + // C++0x [meta.rel]p2: + // If Base and Derived are class types and are different types + // (ignoring possible cv-qualifiers) then Derived shall be a + // complete type. + if (Self.RequireCompleteType(KeyLoc, RhsT, + diag::err_incomplete_type_used_in_type_trait_expr)) + return false; + + return cast<CXXRecordDecl>(rhsRecord->getDecl()) + ->isDerivedFrom(cast<CXXRecordDecl>(lhsRecord->getDecl())); + } + case BTT_IsSame: + return Self.Context.hasSameType(LhsT, RhsT); + case BTT_TypeCompatible: { + // GCC ignores cv-qualifiers on arrays for this builtin. + Qualifiers LhsQuals, RhsQuals; + QualType Lhs = Self.getASTContext().getUnqualifiedArrayType(LhsT, LhsQuals); + QualType Rhs = Self.getASTContext().getUnqualifiedArrayType(RhsT, RhsQuals); + return Self.Context.typesAreCompatible(Lhs, Rhs); + } + case BTT_IsConvertible: + case BTT_IsConvertibleTo: { + // C++0x [meta.rel]p4: + // Given the following function prototype: + // + // template <class T> + // typename add_rvalue_reference<T>::type create(); + // + // the predicate condition for a template specialization + // is_convertible<From, To> shall be satisfied if and only if + // the return expression in the following code would be + // well-formed, including any implicit conversions to the return + // type of the function: + // + // To test() { + // return create<From>(); + // } + // + // Access checking is performed as if in a context unrelated to To and + // From. Only the validity of the immediate context of the expression + // of the return-statement (including conversions to the return type) + // is considered. + // + // We model the initialization as a copy-initialization of a temporary + // of the appropriate type, which for this expression is identical to the + // return statement (since NRVO doesn't apply). + + // Functions aren't allowed to return function or array types. + if (RhsT->isFunctionType() || RhsT->isArrayType()) + return false; + + // A return statement in a void function must have void type. + if (RhsT->isVoidType()) + return LhsT->isVoidType(); + + // A function definition requires a complete, non-abstract return type. + if (!Self.isCompleteType(KeyLoc, RhsT) || Self.isAbstractType(KeyLoc, RhsT)) + return false; + + // Compute the result of add_rvalue_reference. + if (LhsT->isObjectType() || LhsT->isFunctionType()) + LhsT = Self.Context.getRValueReferenceType(LhsT); + + // Build a fake source and destination for initialization. + InitializedEntity To(InitializedEntity::InitializeTemporary(RhsT)); + OpaqueValueExpr From(KeyLoc, LhsT.getNonLValueExprType(Self.Context), + Expr::getValueKindForType(LhsT)); + Expr *FromPtr = &From; + InitializationKind Kind(InitializationKind::CreateCopy(KeyLoc, + SourceLocation())); + + // Perform the initialization in an unevaluated context within a SFINAE + // trap at translation unit scope. + EnterExpressionEvaluationContext Unevaluated( + Self, Sema::ExpressionEvaluationContext::Unevaluated); + Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); + Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); + InitializationSequence Init(Self, To, Kind, FromPtr); + if (Init.Failed()) + return false; + + ExprResult Result = Init.Perform(Self, To, Kind, FromPtr); + return !Result.isInvalid() && !SFINAE.hasErrorOccurred(); + } + + case BTT_IsAssignable: + case BTT_IsNothrowAssignable: + case BTT_IsTriviallyAssignable: { + // C++11 [meta.unary.prop]p3: + // is_trivially_assignable is defined as: + // is_assignable<T, U>::value is true and the assignment, as defined by + // is_assignable, is known to call no operation that is not trivial + // + // is_assignable is defined as: + // The expression declval<T>() = declval<U>() is well-formed when + // treated as an unevaluated operand (Clause 5). + // + // For both, T and U shall be complete types, (possibly cv-qualified) + // void, or arrays of unknown bound. + if (!LhsT->isVoidType() && !LhsT->isIncompleteArrayType() && + Self.RequireCompleteType(KeyLoc, LhsT, + diag::err_incomplete_type_used_in_type_trait_expr)) + return false; + if (!RhsT->isVoidType() && !RhsT->isIncompleteArrayType() && + Self.RequireCompleteType(KeyLoc, RhsT, + diag::err_incomplete_type_used_in_type_trait_expr)) + return false; + + // cv void is never assignable. + if (LhsT->isVoidType() || RhsT->isVoidType()) + return false; + + // Build expressions that emulate the effect of declval<T>() and + // declval<U>(). + if (LhsT->isObjectType() || LhsT->isFunctionType()) + LhsT = Self.Context.getRValueReferenceType(LhsT); + if (RhsT->isObjectType() || RhsT->isFunctionType()) + RhsT = Self.Context.getRValueReferenceType(RhsT); + OpaqueValueExpr Lhs(KeyLoc, LhsT.getNonLValueExprType(Self.Context), + Expr::getValueKindForType(LhsT)); + OpaqueValueExpr Rhs(KeyLoc, RhsT.getNonLValueExprType(Self.Context), + Expr::getValueKindForType(RhsT)); + + // Attempt the assignment in an unevaluated context within a SFINAE + // trap at translation unit scope. + EnterExpressionEvaluationContext Unevaluated( + Self, Sema::ExpressionEvaluationContext::Unevaluated); + Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); + Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); + ExprResult Result = Self.BuildBinOp(/*S=*/nullptr, KeyLoc, BO_Assign, &Lhs, + &Rhs); + if (Result.isInvalid()) + return false; + + // Treat the assignment as unused for the purpose of -Wdeprecated-volatile. + Self.CheckUnusedVolatileAssignment(Result.get()); + + if (SFINAE.hasErrorOccurred()) + return false; + + if (BTT == BTT_IsAssignable) + return true; + + if (BTT == BTT_IsNothrowAssignable) + return Self.canThrow(Result.get()) == CT_Cannot; + + if (BTT == BTT_IsTriviallyAssignable) { + // Under Objective-C ARC and Weak, if the destination has non-trivial + // Objective-C lifetime, this is a non-trivial assignment. + if (LhsT.getNonReferenceType().hasNonTrivialObjCLifetime()) + return false; + + return !Result.get()->hasNonTrivialCall(Self.Context); + } + + llvm_unreachable("unhandled type trait"); + return false; + } + default: llvm_unreachable("not a BTT"); + } + llvm_unreachable("Unknown type trait or not implemented"); +} + +ExprResult Sema::ActOnArrayTypeTrait(ArrayTypeTrait ATT, + SourceLocation KWLoc, + ParsedType Ty, + Expr* DimExpr, + SourceLocation RParen) { + TypeSourceInfo *TSInfo; + QualType T = GetTypeFromParser(Ty, &TSInfo); + if (!TSInfo) + TSInfo = Context.getTrivialTypeSourceInfo(T); + + return BuildArrayTypeTrait(ATT, KWLoc, TSInfo, DimExpr, RParen); +} + +static uint64_t EvaluateArrayTypeTrait(Sema &Self, ArrayTypeTrait ATT, + QualType T, Expr *DimExpr, + SourceLocation KeyLoc) { + assert(!T->isDependentType() && "Cannot evaluate traits of dependent type"); + + switch(ATT) { + case ATT_ArrayRank: + if (T->isArrayType()) { + unsigned Dim = 0; + while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { + ++Dim; + T = AT->getElementType(); + } + return Dim; + } + return 0; + + case ATT_ArrayExtent: { + llvm::APSInt Value; + uint64_t Dim; + if (Self.VerifyIntegerConstantExpression(DimExpr, &Value, + diag::err_dimension_expr_not_constant_integer, + false).isInvalid()) + return 0; + if (Value.isSigned() && Value.isNegative()) { + Self.Diag(KeyLoc, diag::err_dimension_expr_not_constant_integer) + << DimExpr->getSourceRange(); + return 0; + } + Dim = Value.getLimitedValue(); + + if (T->isArrayType()) { + unsigned D = 0; + bool Matched = false; + while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { + if (Dim == D) { + Matched = true; + break; + } + ++D; + T = AT->getElementType(); + } + + if (Matched && T->isArrayType()) { + if (const ConstantArrayType *CAT = Self.Context.getAsConstantArrayType(T)) + return CAT->getSize().getLimitedValue(); + } + } + return 0; + } + } + llvm_unreachable("Unknown type trait or not implemented"); +} + +ExprResult Sema::BuildArrayTypeTrait(ArrayTypeTrait ATT, + SourceLocation KWLoc, + TypeSourceInfo *TSInfo, + Expr* DimExpr, + SourceLocation RParen) { + QualType T = TSInfo->getType(); + + // FIXME: This should likely be tracked as an APInt to remove any host + // assumptions about the width of size_t on the target. + uint64_t Value = 0; + if (!T->isDependentType()) + Value = EvaluateArrayTypeTrait(*this, ATT, T, DimExpr, KWLoc); + + // While the specification for these traits from the Embarcadero C++ + // compiler's documentation says the return type is 'unsigned int', Clang + // returns 'size_t'. On Windows, the primary platform for the Embarcadero + // compiler, there is no difference. On several other platforms this is an + // important distinction. + return new (Context) ArrayTypeTraitExpr(KWLoc, ATT, TSInfo, Value, DimExpr, + RParen, Context.getSizeType()); +} + +ExprResult Sema::ActOnExpressionTrait(ExpressionTrait ET, + SourceLocation KWLoc, + Expr *Queried, + SourceLocation RParen) { + // If error parsing the expression, ignore. + if (!Queried) + return ExprError(); + + ExprResult Result = BuildExpressionTrait(ET, KWLoc, Queried, RParen); + + return Result; +} + +static bool EvaluateExpressionTrait(ExpressionTrait ET, Expr *E) { + switch (ET) { + case ET_IsLValueExpr: return E->isLValue(); + case ET_IsRValueExpr: return E->isRValue(); + } + llvm_unreachable("Expression trait not covered by switch"); +} + +ExprResult Sema::BuildExpressionTrait(ExpressionTrait ET, + SourceLocation KWLoc, + Expr *Queried, + SourceLocation RParen) { + if (Queried->isTypeDependent()) { + // Delay type-checking for type-dependent expressions. + } else if (Queried->getType()->isPlaceholderType()) { + ExprResult PE = CheckPlaceholderExpr(Queried); + if (PE.isInvalid()) return ExprError(); + return BuildExpressionTrait(ET, KWLoc, PE.get(), RParen); + } + + bool Value = EvaluateExpressionTrait(ET, Queried); + + return new (Context) + ExpressionTraitExpr(KWLoc, ET, Queried, Value, RParen, Context.BoolTy); +} + +QualType Sema::CheckPointerToMemberOperands(ExprResult &LHS, ExprResult &RHS, + ExprValueKind &VK, + SourceLocation Loc, + bool isIndirect) { + assert(!LHS.get()->getType()->isPlaceholderType() && + !RHS.get()->getType()->isPlaceholderType() && + "placeholders should have been weeded out by now"); + + // The LHS undergoes lvalue conversions if this is ->*, and undergoes the + // temporary materialization conversion otherwise. + if (isIndirect) + LHS = DefaultLvalueConversion(LHS.get()); + else if (LHS.get()->isRValue()) + LHS = TemporaryMaterializationConversion(LHS.get()); + if (LHS.isInvalid()) + return QualType(); + + // The RHS always undergoes lvalue conversions. + RHS = DefaultLvalueConversion(RHS.get()); + if (RHS.isInvalid()) return QualType(); + + const char *OpSpelling = isIndirect ? "->*" : ".*"; + // C++ 5.5p2 + // The binary operator .* [p3: ->*] binds its second operand, which shall + // be of type "pointer to member of T" (where T is a completely-defined + // class type) [...] + QualType RHSType = RHS.get()->getType(); + const MemberPointerType *MemPtr = RHSType->getAs<MemberPointerType>(); + if (!MemPtr) { + Diag(Loc, diag::err_bad_memptr_rhs) + << OpSpelling << RHSType << RHS.get()->getSourceRange(); + return QualType(); + } + + QualType Class(MemPtr->getClass(), 0); + + // Note: C++ [expr.mptr.oper]p2-3 says that the class type into which the + // member pointer points must be completely-defined. However, there is no + // reason for this semantic distinction, and the rule is not enforced by + // other compilers. Therefore, we do not check this property, as it is + // likely to be considered a defect. + + // C++ 5.5p2 + // [...] to its first operand, which shall be of class T or of a class of + // which T is an unambiguous and accessible base class. [p3: a pointer to + // such a class] + QualType LHSType = LHS.get()->getType(); + if (isIndirect) { + if (const PointerType *Ptr = LHSType->getAs<PointerType>()) + LHSType = Ptr->getPointeeType(); + else { + Diag(Loc, diag::err_bad_memptr_lhs) + << OpSpelling << 1 << LHSType + << FixItHint::CreateReplacement(SourceRange(Loc), ".*"); + return QualType(); + } + } + + if (!Context.hasSameUnqualifiedType(Class, LHSType)) { + // If we want to check the hierarchy, we need a complete type. + if (RequireCompleteType(Loc, LHSType, diag::err_bad_memptr_lhs, + OpSpelling, (int)isIndirect)) { + return QualType(); + } + + if (!IsDerivedFrom(Loc, LHSType, Class)) { + Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling + << (int)isIndirect << LHS.get()->getType(); + return QualType(); + } + + CXXCastPath BasePath; + if (CheckDerivedToBaseConversion( + LHSType, Class, Loc, + SourceRange(LHS.get()->getBeginLoc(), RHS.get()->getEndLoc()), + &BasePath)) + return QualType(); + + // Cast LHS to type of use. + QualType UseType = Context.getQualifiedType(Class, LHSType.getQualifiers()); + if (isIndirect) + UseType = Context.getPointerType(UseType); + ExprValueKind VK = isIndirect ? VK_RValue : LHS.get()->getValueKind(); + LHS = ImpCastExprToType(LHS.get(), UseType, CK_DerivedToBase, VK, + &BasePath); + } + + if (isa<CXXScalarValueInitExpr>(RHS.get()->IgnoreParens())) { + // Diagnose use of pointer-to-member type which when used as + // the functional cast in a pointer-to-member expression. + Diag(Loc, diag::err_pointer_to_member_type) << isIndirect; + return QualType(); + } + + // C++ 5.5p2 + // The result is an object or a function of the type specified by the + // second operand. + // The cv qualifiers are the union of those in the pointer and the left side, + // in accordance with 5.5p5 and 5.2.5. + QualType Result = MemPtr->getPointeeType(); + Result = Context.getCVRQualifiedType(Result, LHSType.getCVRQualifiers()); + + // C++0x [expr.mptr.oper]p6: + // In a .* expression whose object expression is an rvalue, the program is + // ill-formed if the second operand is a pointer to member function with + // ref-qualifier &. In a ->* expression or in a .* expression whose object + // expression is an lvalue, the program is ill-formed if the second operand + // is a pointer to member function with ref-qualifier &&. + if (const FunctionProtoType *Proto = Result->getAs<FunctionProtoType>()) { + switch (Proto->getRefQualifier()) { + case RQ_None: + // Do nothing + break; + + case RQ_LValue: + if (!isIndirect && !LHS.get()->Classify(Context).isLValue()) { + // C++2a allows functions with ref-qualifier & if their cv-qualifier-seq + // is (exactly) 'const'. + if (Proto->isConst() && !Proto->isVolatile()) + Diag(Loc, getLangOpts().CPlusPlus2a + ? diag::warn_cxx17_compat_pointer_to_const_ref_member_on_rvalue + : diag::ext_pointer_to_const_ref_member_on_rvalue); + else + Diag(Loc, diag::err_pointer_to_member_oper_value_classify) + << RHSType << 1 << LHS.get()->getSourceRange(); + } + break; + + case RQ_RValue: + if (isIndirect || !LHS.get()->Classify(Context).isRValue()) + Diag(Loc, diag::err_pointer_to_member_oper_value_classify) + << RHSType << 0 << LHS.get()->getSourceRange(); + break; + } + } + + // C++ [expr.mptr.oper]p6: + // The result of a .* expression whose second operand is a pointer + // to a data member is of the same value category as its + // first operand. The result of a .* expression whose second + // operand is a pointer to a member function is a prvalue. The + // result of an ->* expression is an lvalue if its second operand + // is a pointer to data member and a prvalue otherwise. + if (Result->isFunctionType()) { + VK = VK_RValue; + return Context.BoundMemberTy; + } else if (isIndirect) { + VK = VK_LValue; + } else { + VK = LHS.get()->getValueKind(); + } + + return Result; +} + +/// Try to convert a type to another according to C++11 5.16p3. +/// +/// This is part of the parameter validation for the ? operator. If either +/// value operand is a class type, the two operands are attempted to be +/// converted to each other. This function does the conversion in one direction. +/// It returns true if the program is ill-formed and has already been diagnosed +/// as such. +static bool TryClassUnification(Sema &Self, Expr *From, Expr *To, + SourceLocation QuestionLoc, + bool &HaveConversion, + QualType &ToType) { + HaveConversion = false; + ToType = To->getType(); + + InitializationKind Kind = + InitializationKind::CreateCopy(To->getBeginLoc(), SourceLocation()); + // C++11 5.16p3 + // The process for determining whether an operand expression E1 of type T1 + // can be converted to match an operand expression E2 of type T2 is defined + // as follows: + // -- If E2 is an lvalue: E1 can be converted to match E2 if E1 can be + // implicitly converted to type "lvalue reference to T2", subject to the + // constraint that in the conversion the reference must bind directly to + // an lvalue. + // -- If E2 is an xvalue: E1 can be converted to match E2 if E1 can be + // implicitly converted to the type "rvalue reference to R2", subject to + // the constraint that the reference must bind directly. + if (To->isLValue() || To->isXValue()) { + QualType T = To->isLValue() ? Self.Context.getLValueReferenceType(ToType) + : Self.Context.getRValueReferenceType(ToType); + + InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); + + InitializationSequence InitSeq(Self, Entity, Kind, From); + if (InitSeq.isDirectReferenceBinding()) { + ToType = T; + HaveConversion = true; + return false; + } + + if (InitSeq.isAmbiguous()) + return InitSeq.Diagnose(Self, Entity, Kind, From); + } + + // -- If E2 is an rvalue, or if the conversion above cannot be done: + // -- if E1 and E2 have class type, and the underlying class types are + // the same or one is a base class of the other: + QualType FTy = From->getType(); + QualType TTy = To->getType(); + const RecordType *FRec = FTy->getAs<RecordType>(); + const RecordType *TRec = TTy->getAs<RecordType>(); + bool FDerivedFromT = FRec && TRec && FRec != TRec && + Self.IsDerivedFrom(QuestionLoc, FTy, TTy); + if (FRec && TRec && (FRec == TRec || FDerivedFromT || + Self.IsDerivedFrom(QuestionLoc, TTy, FTy))) { + // E1 can be converted to match E2 if the class of T2 is the + // same type as, or a base class of, the class of T1, and + // [cv2 > cv1]. + if (FRec == TRec || FDerivedFromT) { + if (TTy.isAtLeastAsQualifiedAs(FTy)) { + InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); + InitializationSequence InitSeq(Self, Entity, Kind, From); + if (InitSeq) { + HaveConversion = true; + return false; + } + + if (InitSeq.isAmbiguous()) + return InitSeq.Diagnose(Self, Entity, Kind, From); + } + } + + return false; + } + + // -- Otherwise: E1 can be converted to match E2 if E1 can be + // implicitly converted to the type that expression E2 would have + // if E2 were converted to an rvalue (or the type it has, if E2 is + // an rvalue). + // + // This actually refers very narrowly to the lvalue-to-rvalue conversion, not + // to the array-to-pointer or function-to-pointer conversions. + TTy = TTy.getNonLValueExprType(Self.Context); + + InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); + InitializationSequence InitSeq(Self, Entity, Kind, From); + HaveConversion = !InitSeq.Failed(); + ToType = TTy; + if (InitSeq.isAmbiguous()) + return InitSeq.Diagnose(Self, Entity, Kind, From); + + return false; +} + +/// Try to find a common type for two according to C++0x 5.16p5. +/// +/// This is part of the parameter validation for the ? operator. If either +/// value operand is a class type, overload resolution is used to find a +/// conversion to a common type. +static bool FindConditionalOverload(Sema &Self, ExprResult &LHS, ExprResult &RHS, + SourceLocation QuestionLoc) { + Expr *Args[2] = { LHS.get(), RHS.get() }; + OverloadCandidateSet CandidateSet(QuestionLoc, + OverloadCandidateSet::CSK_Operator); + Self.AddBuiltinOperatorCandidates(OO_Conditional, QuestionLoc, Args, + CandidateSet); + + OverloadCandidateSet::iterator Best; + switch (CandidateSet.BestViableFunction(Self, QuestionLoc, Best)) { + case OR_Success: { + // We found a match. Perform the conversions on the arguments and move on. + ExprResult LHSRes = Self.PerformImplicitConversion( + LHS.get(), Best->BuiltinParamTypes[0], Best->Conversions[0], + Sema::AA_Converting); + if (LHSRes.isInvalid()) + break; + LHS = LHSRes; + + ExprResult RHSRes = Self.PerformImplicitConversion( + RHS.get(), Best->BuiltinParamTypes[1], Best->Conversions[1], + Sema::AA_Converting); + if (RHSRes.isInvalid()) + break; + RHS = RHSRes; + if (Best->Function) + Self.MarkFunctionReferenced(QuestionLoc, Best->Function); + return false; + } + + case OR_No_Viable_Function: + + // Emit a better diagnostic if one of the expressions is a null pointer + // constant and the other is a pointer type. In this case, the user most + // likely forgot to take the address of the other expression. + if (Self.DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) + return true; + + Self.Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) + << LHS.get()->getType() << RHS.get()->getType() + << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + return true; + + case OR_Ambiguous: + Self.Diag(QuestionLoc, diag::err_conditional_ambiguous_ovl) + << LHS.get()->getType() << RHS.get()->getType() + << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + // FIXME: Print the possible common types by printing the return types of + // the viable candidates. + break; + + case OR_Deleted: + llvm_unreachable("Conditional operator has only built-in overloads"); + } + return true; +} + +/// Perform an "extended" implicit conversion as returned by +/// TryClassUnification. +static bool ConvertForConditional(Sema &Self, ExprResult &E, QualType T) { + InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); + InitializationKind Kind = + InitializationKind::CreateCopy(E.get()->getBeginLoc(), SourceLocation()); + Expr *Arg = E.get(); + InitializationSequence InitSeq(Self, Entity, Kind, Arg); + ExprResult Result = InitSeq.Perform(Self, Entity, Kind, Arg); + if (Result.isInvalid()) + return true; + + E = Result; + return false; +} + +/// Check the operands of ?: under C++ semantics. +/// +/// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y +/// extension. In this case, LHS == Cond. (But they're not aliases.) +QualType Sema::CXXCheckConditionalOperands(ExprResult &Cond, ExprResult &LHS, + ExprResult &RHS, ExprValueKind &VK, + ExprObjectKind &OK, + SourceLocation QuestionLoc) { + // FIXME: Handle C99's complex types, vector types, block pointers and Obj-C++ + // interface pointers. + + // C++11 [expr.cond]p1 + // The first expression is contextually converted to bool. + // + // FIXME; GCC's vector extension permits the use of a?b:c where the type of + // a is that of a integer vector with the same number of elements and + // size as the vectors of b and c. If one of either b or c is a scalar + // it is implicitly converted to match the type of the vector. + // Otherwise the expression is ill-formed. If both b and c are scalars, + // then b and c are checked and converted to the type of a if possible. + // Unlike the OpenCL ?: operator, the expression is evaluated as + // (a[0] != 0 ? b[0] : c[0], .. , a[n] != 0 ? b[n] : c[n]). + if (!Cond.get()->isTypeDependent()) { + ExprResult CondRes = CheckCXXBooleanCondition(Cond.get()); + if (CondRes.isInvalid()) + return QualType(); + Cond = CondRes; + } + + // Assume r-value. + VK = VK_RValue; + OK = OK_Ordinary; + + // Either of the arguments dependent? + if (LHS.get()->isTypeDependent() || RHS.get()->isTypeDependent()) + return Context.DependentTy; + + // C++11 [expr.cond]p2 + // If either the second or the third operand has type (cv) void, ... + QualType LTy = LHS.get()->getType(); + QualType RTy = RHS.get()->getType(); + bool LVoid = LTy->isVoidType(); + bool RVoid = RTy->isVoidType(); + if (LVoid || RVoid) { + // ... one of the following shall hold: + // -- The second or the third operand (but not both) is a (possibly + // parenthesized) throw-expression; the result is of the type + // and value category of the other. + bool LThrow = isa<CXXThrowExpr>(LHS.get()->IgnoreParenImpCasts()); + bool RThrow = isa<CXXThrowExpr>(RHS.get()->IgnoreParenImpCasts()); + if (LThrow != RThrow) { + Expr *NonThrow = LThrow ? RHS.get() : LHS.get(); + VK = NonThrow->getValueKind(); + // DR (no number yet): the result is a bit-field if the + // non-throw-expression operand is a bit-field. + OK = NonThrow->getObjectKind(); + return NonThrow->getType(); + } + + // -- Both the second and third operands have type void; the result is of + // type void and is a prvalue. + if (LVoid && RVoid) + return Context.VoidTy; + + // Neither holds, error. + Diag(QuestionLoc, diag::err_conditional_void_nonvoid) + << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1) + << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + return QualType(); + } + + // Neither is void. + + // C++11 [expr.cond]p3 + // Otherwise, if the second and third operand have different types, and + // either has (cv) class type [...] an attempt is made to convert each of + // those operands to the type of the other. + if (!Context.hasSameType(LTy, RTy) && + (LTy->isRecordType() || RTy->isRecordType())) { + // These return true if a single direction is already ambiguous. + QualType L2RType, R2LType; + bool HaveL2R, HaveR2L; + if (TryClassUnification(*this, LHS.get(), RHS.get(), QuestionLoc, HaveL2R, L2RType)) + return QualType(); + if (TryClassUnification(*this, RHS.get(), LHS.get(), QuestionLoc, HaveR2L, R2LType)) + return QualType(); + + // If both can be converted, [...] the program is ill-formed. + if (HaveL2R && HaveR2L) { + Diag(QuestionLoc, diag::err_conditional_ambiguous) + << LTy << RTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + return QualType(); + } + + // If exactly one conversion is possible, that conversion is applied to + // the chosen operand and the converted operands are used in place of the + // original operands for the remainder of this section. + if (HaveL2R) { + if (ConvertForConditional(*this, LHS, L2RType) || LHS.isInvalid()) + return QualType(); + LTy = LHS.get()->getType(); + } else if (HaveR2L) { + if (ConvertForConditional(*this, RHS, R2LType) || RHS.isInvalid()) + return QualType(); + RTy = RHS.get()->getType(); + } + } + + // C++11 [expr.cond]p3 + // if both are glvalues of the same value category and the same type except + // for cv-qualification, an attempt is made to convert each of those + // operands to the type of the other. + // FIXME: + // Resolving a defect in P0012R1: we extend this to cover all cases where + // one of the operands is reference-compatible with the other, in order + // to support conditionals between functions differing in noexcept. + ExprValueKind LVK = LHS.get()->getValueKind(); + ExprValueKind RVK = RHS.get()->getValueKind(); + if (!Context.hasSameType(LTy, RTy) && + LVK == RVK && LVK != VK_RValue) { + // DerivedToBase was already handled by the class-specific case above. + // FIXME: Should we allow ObjC conversions here? + bool DerivedToBase, ObjCConversion, ObjCLifetimeConversion, + FunctionConversion; + if (CompareReferenceRelationship(QuestionLoc, LTy, RTy, DerivedToBase, + ObjCConversion, ObjCLifetimeConversion, + FunctionConversion) == Ref_Compatible && + !DerivedToBase && !ObjCConversion && !ObjCLifetimeConversion && + // [...] subject to the constraint that the reference must bind + // directly [...] + !RHS.get()->refersToBitField() && !RHS.get()->refersToVectorElement()) { + RHS = ImpCastExprToType(RHS.get(), LTy, CK_NoOp, RVK); + RTy = RHS.get()->getType(); + } else if (CompareReferenceRelationship( + QuestionLoc, RTy, LTy, DerivedToBase, ObjCConversion, + ObjCLifetimeConversion, + FunctionConversion) == Ref_Compatible && + !DerivedToBase && !ObjCConversion && !ObjCLifetimeConversion && + !LHS.get()->refersToBitField() && + !LHS.get()->refersToVectorElement()) { + LHS = ImpCastExprToType(LHS.get(), RTy, CK_NoOp, LVK); + LTy = LHS.get()->getType(); + } + } + + // C++11 [expr.cond]p4 + // If the second and third operands are glvalues of the same value + // category and have the same type, the result is of that type and + // value category and it is a bit-field if the second or the third + // operand is a bit-field, or if both are bit-fields. + // We only extend this to bitfields, not to the crazy other kinds of + // l-values. + bool Same = Context.hasSameType(LTy, RTy); + if (Same && LVK == RVK && LVK != VK_RValue && + LHS.get()->isOrdinaryOrBitFieldObject() && + RHS.get()->isOrdinaryOrBitFieldObject()) { + VK = LHS.get()->getValueKind(); + if (LHS.get()->getObjectKind() == OK_BitField || + RHS.get()->getObjectKind() == OK_BitField) + OK = OK_BitField; + + // If we have function pointer types, unify them anyway to unify their + // exception specifications, if any. + if (LTy->isFunctionPointerType() || LTy->isMemberFunctionPointerType()) { + Qualifiers Qs = LTy.getQualifiers(); + LTy = FindCompositePointerType(QuestionLoc, LHS, RHS, + /*ConvertArgs*/false); + LTy = Context.getQualifiedType(LTy, Qs); + + assert(!LTy.isNull() && "failed to find composite pointer type for " + "canonically equivalent function ptr types"); + assert(Context.hasSameType(LTy, RTy) && "bad composite pointer type"); + } + + return LTy; + } + + // C++11 [expr.cond]p5 + // Otherwise, the result is a prvalue. If the second and third operands + // do not have the same type, and either has (cv) class type, ... + if (!Same && (LTy->isRecordType() || RTy->isRecordType())) { + // ... overload resolution is used to determine the conversions (if any) + // to be applied to the operands. If the overload resolution fails, the + // program is ill-formed. + if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc)) + return QualType(); + } + + // C++11 [expr.cond]p6 + // Lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard + // conversions are performed on the second and third operands. + LHS = DefaultFunctionArrayLvalueConversion(LHS.get()); + RHS = DefaultFunctionArrayLvalueConversion(RHS.get()); + if (LHS.isInvalid() || RHS.isInvalid()) + return QualType(); + LTy = LHS.get()->getType(); + RTy = RHS.get()->getType(); + + // After those conversions, one of the following shall hold: + // -- The second and third operands have the same type; the result + // is of that type. If the operands have class type, the result + // is a prvalue temporary of the result type, which is + // copy-initialized from either the second operand or the third + // operand depending on the value of the first operand. + if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) { + if (LTy->isRecordType()) { + // The operands have class type. Make a temporary copy. + InitializedEntity Entity = InitializedEntity::InitializeTemporary(LTy); + + ExprResult LHSCopy = PerformCopyInitialization(Entity, + SourceLocation(), + LHS); + if (LHSCopy.isInvalid()) + return QualType(); + + ExprResult RHSCopy = PerformCopyInitialization(Entity, + SourceLocation(), + RHS); + if (RHSCopy.isInvalid()) + return QualType(); + + LHS = LHSCopy; + RHS = RHSCopy; + } + + // If we have function pointer types, unify them anyway to unify their + // exception specifications, if any. + if (LTy->isFunctionPointerType() || LTy->isMemberFunctionPointerType()) { + LTy = FindCompositePointerType(QuestionLoc, LHS, RHS); + assert(!LTy.isNull() && "failed to find composite pointer type for " + "canonically equivalent function ptr types"); + } + + return LTy; + } + + // Extension: conditional operator involving vector types. + if (LTy->isVectorType() || RTy->isVectorType()) + return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false, + /*AllowBothBool*/true, + /*AllowBoolConversions*/false); + + // -- The second and third operands have arithmetic or enumeration type; + // the usual arithmetic conversions are performed to bring them to a + // common type, and the result is of that type. + if (LTy->isArithmeticType() && RTy->isArithmeticType()) { + QualType ResTy = UsualArithmeticConversions(LHS, RHS); + if (LHS.isInvalid() || RHS.isInvalid()) + return QualType(); + if (ResTy.isNull()) { + Diag(QuestionLoc, + diag::err_typecheck_cond_incompatible_operands) << LTy << RTy + << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + return QualType(); + } + + LHS = ImpCastExprToType(LHS.get(), ResTy, PrepareScalarCast(LHS, ResTy)); + RHS = ImpCastExprToType(RHS.get(), ResTy, PrepareScalarCast(RHS, ResTy)); + + return ResTy; + } + + // -- The second and third operands have pointer type, or one has pointer + // type and the other is a null pointer constant, or both are null + // pointer constants, at least one of which is non-integral; pointer + // conversions and qualification conversions are performed to bring them + // to their composite pointer type. The result is of the composite + // pointer type. + // -- The second and third operands have pointer to member type, or one has + // pointer to member type and the other is a null pointer constant; + // pointer to member conversions and qualification conversions are + // performed to bring them to a common type, whose cv-qualification + // shall match the cv-qualification of either the second or the third + // operand. The result is of the common type. + QualType Composite = FindCompositePointerType(QuestionLoc, LHS, RHS); + if (!Composite.isNull()) + return Composite; + + // Similarly, attempt to find composite type of two objective-c pointers. + Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc); + if (!Composite.isNull()) + return Composite; + + // Check if we are using a null with a non-pointer type. + if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) + return QualType(); + + Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) + << LHS.get()->getType() << RHS.get()->getType() + << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + return QualType(); +} + +static FunctionProtoType::ExceptionSpecInfo +mergeExceptionSpecs(Sema &S, FunctionProtoType::ExceptionSpecInfo ESI1, + FunctionProtoType::ExceptionSpecInfo ESI2, + SmallVectorImpl<QualType> &ExceptionTypeStorage) { + ExceptionSpecificationType EST1 = ESI1.Type; + ExceptionSpecificationType EST2 = ESI2.Type; + + // If either of them can throw anything, that is the result. + if (EST1 == EST_None) return ESI1; + if (EST2 == EST_None) return ESI2; + if (EST1 == EST_MSAny) return ESI1; + if (EST2 == EST_MSAny) return ESI2; + if (EST1 == EST_NoexceptFalse) return ESI1; + if (EST2 == EST_NoexceptFalse) return ESI2; + + // If either of them is non-throwing, the result is the other. + if (EST1 == EST_NoThrow) return ESI2; + if (EST2 == EST_NoThrow) return ESI1; + if (EST1 == EST_DynamicNone) return ESI2; + if (EST2 == EST_DynamicNone) return ESI1; + if (EST1 == EST_BasicNoexcept) return ESI2; + if (EST2 == EST_BasicNoexcept) return ESI1; + if (EST1 == EST_NoexceptTrue) return ESI2; + if (EST2 == EST_NoexceptTrue) return ESI1; + + // If we're left with value-dependent computed noexcept expressions, we're + // stuck. Before C++17, we can just drop the exception specification entirely, + // since it's not actually part of the canonical type. And this should never + // happen in C++17, because it would mean we were computing the composite + // pointer type of dependent types, which should never happen. + if (EST1 == EST_DependentNoexcept || EST2 == EST_DependentNoexcept) { + assert(!S.getLangOpts().CPlusPlus17 && + "computing composite pointer type of dependent types"); + return FunctionProtoType::ExceptionSpecInfo(); + } + + // Switch over the possibilities so that people adding new values know to + // update this function. + switch (EST1) { + case EST_None: + case EST_DynamicNone: + case EST_MSAny: + case EST_BasicNoexcept: + case EST_DependentNoexcept: + case EST_NoexceptFalse: + case EST_NoexceptTrue: + case EST_NoThrow: + llvm_unreachable("handled above"); + + case EST_Dynamic: { + // This is the fun case: both exception specifications are dynamic. Form + // the union of the two lists. + assert(EST2 == EST_Dynamic && "other cases should already be handled"); + llvm::SmallPtrSet<QualType, 8> Found; + for (auto &Exceptions : {ESI1.Exceptions, ESI2.Exceptions}) + for (QualType E : Exceptions) + if (Found.insert(S.Context.getCanonicalType(E)).second) + ExceptionTypeStorage.push_back(E); + + FunctionProtoType::ExceptionSpecInfo Result(EST_Dynamic); + Result.Exceptions = ExceptionTypeStorage; + return Result; + } + + case EST_Unevaluated: + case EST_Uninstantiated: + case EST_Unparsed: + llvm_unreachable("shouldn't see unresolved exception specifications here"); + } + + llvm_unreachable("invalid ExceptionSpecificationType"); +} + +/// Find a merged pointer type and convert the two expressions to it. +/// +/// This finds the composite pointer type (or member pointer type) for @p E1 +/// and @p E2 according to C++1z 5p14. It converts both expressions to this +/// type and returns it. +/// It does not emit diagnostics. +/// +/// \param Loc The location of the operator requiring these two expressions to +/// be converted to the composite pointer type. +/// +/// \param ConvertArgs If \c false, do not convert E1 and E2 to the target type. +QualType Sema::FindCompositePointerType(SourceLocation Loc, + Expr *&E1, Expr *&E2, + bool ConvertArgs) { + assert(getLangOpts().CPlusPlus && "This function assumes C++"); + + // C++1z [expr]p14: + // The composite pointer type of two operands p1 and p2 having types T1 + // and T2 + QualType T1 = E1->getType(), T2 = E2->getType(); + + // where at least one is a pointer or pointer to member type or + // std::nullptr_t is: + bool T1IsPointerLike = T1->isAnyPointerType() || T1->isMemberPointerType() || + T1->isNullPtrType(); + bool T2IsPointerLike = T2->isAnyPointerType() || T2->isMemberPointerType() || + T2->isNullPtrType(); + if (!T1IsPointerLike && !T2IsPointerLike) + return QualType(); + + // - if both p1 and p2 are null pointer constants, std::nullptr_t; + // This can't actually happen, following the standard, but we also use this + // to implement the end of [expr.conv], which hits this case. + // + // - if either p1 or p2 is a null pointer constant, T2 or T1, respectively; + if (T1IsPointerLike && + E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { + if (ConvertArgs) + E2 = ImpCastExprToType(E2, T1, T1->isMemberPointerType() + ? CK_NullToMemberPointer + : CK_NullToPointer).get(); + return T1; + } + if (T2IsPointerLike && + E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { + if (ConvertArgs) + E1 = ImpCastExprToType(E1, T2, T2->isMemberPointerType() + ? CK_NullToMemberPointer + : CK_NullToPointer).get(); + return T2; + } + + // Now both have to be pointers or member pointers. + if (!T1IsPointerLike || !T2IsPointerLike) + return QualType(); + assert(!T1->isNullPtrType() && !T2->isNullPtrType() && + "nullptr_t should be a null pointer constant"); + + // - if T1 or T2 is "pointer to cv1 void" and the other type is + // "pointer to cv2 T", "pointer to cv12 void", where cv12 is + // the union of cv1 and cv2; + // - if T1 or T2 is "pointer to noexcept function" and the other type is + // "pointer to function", where the function types are otherwise the same, + // "pointer to function"; + // FIXME: This rule is defective: it should also permit removing noexcept + // from a pointer to member function. As a Clang extension, we also + // permit removing 'noreturn', so we generalize this rule to; + // - [Clang] If T1 and T2 are both of type "pointer to function" or + // "pointer to member function" and the pointee types can be unified + // by a function pointer conversion, that conversion is applied + // before checking the following rules. + // - if T1 is "pointer to cv1 C1" and T2 is "pointer to cv2 C2", where C1 + // is reference-related to C2 or C2 is reference-related to C1 (8.6.3), + // the cv-combined type of T1 and T2 or the cv-combined type of T2 and T1, + // respectively; + // - if T1 is "pointer to member of C1 of type cv1 U1" and T2 is "pointer + // to member of C2 of type cv2 U2" where C1 is reference-related to C2 or + // C2 is reference-related to C1 (8.6.3), the cv-combined type of T2 and + // T1 or the cv-combined type of T1 and T2, respectively; + // - if T1 and T2 are similar types (4.5), the cv-combined type of T1 and + // T2; + // + // If looked at in the right way, these bullets all do the same thing. + // What we do here is, we build the two possible cv-combined types, and try + // the conversions in both directions. If only one works, or if the two + // composite types are the same, we have succeeded. + // FIXME: extended qualifiers? + // + // Note that this will fail to find a composite pointer type for "pointer + // to void" and "pointer to function". We can't actually perform the final + // conversion in this case, even though a composite pointer type formally + // exists. + SmallVector<unsigned, 4> QualifierUnion; + SmallVector<std::pair<const Type *, const Type *>, 4> MemberOfClass; + QualType Composite1 = T1; + QualType Composite2 = T2; + unsigned NeedConstBefore = 0; + while (true) { + const PointerType *Ptr1, *Ptr2; + if ((Ptr1 = Composite1->getAs<PointerType>()) && + (Ptr2 = Composite2->getAs<PointerType>())) { + Composite1 = Ptr1->getPointeeType(); + Composite2 = Ptr2->getPointeeType(); + + // If we're allowed to create a non-standard composite type, keep track + // of where we need to fill in additional 'const' qualifiers. + if (Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers()) + NeedConstBefore = QualifierUnion.size(); + + QualifierUnion.push_back( + Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); + MemberOfClass.push_back(std::make_pair(nullptr, nullptr)); + continue; + } + + const MemberPointerType *MemPtr1, *MemPtr2; + if ((MemPtr1 = Composite1->getAs<MemberPointerType>()) && + (MemPtr2 = Composite2->getAs<MemberPointerType>())) { + Composite1 = MemPtr1->getPointeeType(); + Composite2 = MemPtr2->getPointeeType(); + + // If we're allowed to create a non-standard composite type, keep track + // of where we need to fill in additional 'const' qualifiers. + if (Composite1.getCVRQualifiers() != Composite2.getCVRQualifiers()) + NeedConstBefore = QualifierUnion.size(); + + QualifierUnion.push_back( + Composite1.getCVRQualifiers() | Composite2.getCVRQualifiers()); + MemberOfClass.push_back(std::make_pair(MemPtr1->getClass(), + MemPtr2->getClass())); + continue; + } + + // FIXME: block pointer types? + + // Cannot unwrap any more types. + break; + } + + // Apply the function pointer conversion to unify the types. We've already + // unwrapped down to the function types, and we want to merge rather than + // just convert, so do this ourselves rather than calling + // IsFunctionConversion. + // + // FIXME: In order to match the standard wording as closely as possible, we + // currently only do this under a single level of pointers. Ideally, we would + // allow this in general, and set NeedConstBefore to the relevant depth on + // the side(s) where we changed anything. + if (QualifierUnion.size() == 1) { + if (auto *FPT1 = Composite1->getAs<FunctionProtoType>()) { + if (auto *FPT2 = Composite2->getAs<FunctionProtoType>()) { + FunctionProtoType::ExtProtoInfo EPI1 = FPT1->getExtProtoInfo(); + FunctionProtoType::ExtProtoInfo EPI2 = FPT2->getExtProtoInfo(); + + // The result is noreturn if both operands are. + bool Noreturn = + EPI1.ExtInfo.getNoReturn() && EPI2.ExtInfo.getNoReturn(); + EPI1.ExtInfo = EPI1.ExtInfo.withNoReturn(Noreturn); + EPI2.ExtInfo = EPI2.ExtInfo.withNoReturn(Noreturn); + + // The result is nothrow if both operands are. + SmallVector<QualType, 8> ExceptionTypeStorage; + EPI1.ExceptionSpec = EPI2.ExceptionSpec = + mergeExceptionSpecs(*this, EPI1.ExceptionSpec, EPI2.ExceptionSpec, + ExceptionTypeStorage); + + Composite1 = Context.getFunctionType(FPT1->getReturnType(), + FPT1->getParamTypes(), EPI1); + Composite2 = Context.getFunctionType(FPT2->getReturnType(), + FPT2->getParamTypes(), EPI2); + } + } + } + + if (NeedConstBefore) { + // Extension: Add 'const' to qualifiers that come before the first qualifier + // mismatch, so that our (non-standard!) composite type meets the + // requirements of C++ [conv.qual]p4 bullet 3. + for (unsigned I = 0; I != NeedConstBefore; ++I) + if ((QualifierUnion[I] & Qualifiers::Const) == 0) + QualifierUnion[I] = QualifierUnion[I] | Qualifiers::Const; + } + + // Rewrap the composites as pointers or member pointers with the union CVRs. + auto MOC = MemberOfClass.rbegin(); + for (unsigned CVR : llvm::reverse(QualifierUnion)) { + Qualifiers Quals = Qualifiers::fromCVRMask(CVR); + auto Classes = *MOC++; + if (Classes.first && Classes.second) { + // Rebuild member pointer type + Composite1 = Context.getMemberPointerType( + Context.getQualifiedType(Composite1, Quals), Classes.first); + Composite2 = Context.getMemberPointerType( + Context.getQualifiedType(Composite2, Quals), Classes.second); + } else { + // Rebuild pointer type + Composite1 = + Context.getPointerType(Context.getQualifiedType(Composite1, Quals)); + Composite2 = + Context.getPointerType(Context.getQualifiedType(Composite2, Quals)); + } + } + + struct Conversion { + Sema &S; + Expr *&E1, *&E2; + QualType Composite; + InitializedEntity Entity; + InitializationKind Kind; + InitializationSequence E1ToC, E2ToC; + bool Viable; + + Conversion(Sema &S, SourceLocation Loc, Expr *&E1, Expr *&E2, + QualType Composite) + : S(S), E1(E1), E2(E2), Composite(Composite), + Entity(InitializedEntity::InitializeTemporary(Composite)), + Kind(InitializationKind::CreateCopy(Loc, SourceLocation())), + E1ToC(S, Entity, Kind, E1), E2ToC(S, Entity, Kind, E2), + Viable(E1ToC && E2ToC) {} + + bool perform() { + ExprResult E1Result = E1ToC.Perform(S, Entity, Kind, E1); + if (E1Result.isInvalid()) + return true; + E1 = E1Result.getAs<Expr>(); + + ExprResult E2Result = E2ToC.Perform(S, Entity, Kind, E2); + if (E2Result.isInvalid()) + return true; + E2 = E2Result.getAs<Expr>(); + + return false; + } + }; + + // Try to convert to each composite pointer type. + Conversion C1(*this, Loc, E1, E2, Composite1); + if (C1.Viable && Context.hasSameType(Composite1, Composite2)) { + if (ConvertArgs && C1.perform()) + return QualType(); + return C1.Composite; + } + Conversion C2(*this, Loc, E1, E2, Composite2); + + if (C1.Viable == C2.Viable) { + // Either Composite1 and Composite2 are viable and are different, or + // neither is viable. + // FIXME: How both be viable and different? + return QualType(); + } + + // Convert to the chosen type. + if (ConvertArgs && (C1.Viable ? C1 : C2).perform()) + return QualType(); + + return C1.Viable ? C1.Composite : C2.Composite; +} + +ExprResult Sema::MaybeBindToTemporary(Expr *E) { + if (!E) + return ExprError(); + + assert(!isa<CXXBindTemporaryExpr>(E) && "Double-bound temporary?"); + + // If the result is a glvalue, we shouldn't bind it. + if (!E->isRValue()) + return E; + + // In ARC, calls that return a retainable type can return retained, + // in which case we have to insert a consuming cast. + if (getLangOpts().ObjCAutoRefCount && + E->getType()->isObjCRetainableType()) { + + bool ReturnsRetained; + + // For actual calls, we compute this by examining the type of the + // called value. + if (CallExpr *Call = dyn_cast<CallExpr>(E)) { + Expr *Callee = Call->getCallee()->IgnoreParens(); + QualType T = Callee->getType(); + + if (T == Context.BoundMemberTy) { + // Handle pointer-to-members. + if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Callee)) + T = BinOp->getRHS()->getType(); + else if (MemberExpr *Mem = dyn_cast<MemberExpr>(Callee)) + T = Mem->getMemberDecl()->getType(); + } + + if (const PointerType *Ptr = T->getAs<PointerType>()) + T = Ptr->getPointeeType(); + else if (const BlockPointerType *Ptr = T->getAs<BlockPointerType>()) + T = Ptr->getPointeeType(); + else if (const MemberPointerType *MemPtr = T->getAs<MemberPointerType>()) + T = MemPtr->getPointeeType(); + + const FunctionType *FTy = T->getAs<FunctionType>(); + assert(FTy && "call to value not of function type?"); + ReturnsRetained = FTy->getExtInfo().getProducesResult(); + + // ActOnStmtExpr arranges things so that StmtExprs of retainable + // type always produce a +1 object. + } else if (isa<StmtExpr>(E)) { + ReturnsRetained = true; + + // We hit this case with the lambda conversion-to-block optimization; + // we don't want any extra casts here. + } else if (isa<CastExpr>(E) && + isa<BlockExpr>(cast<CastExpr>(E)->getSubExpr())) { + return E; + + // For message sends and property references, we try to find an + // actual method. FIXME: we should infer retention by selector in + // cases where we don't have an actual method. + } else { + ObjCMethodDecl *D = nullptr; + if (ObjCMessageExpr *Send = dyn_cast<ObjCMessageExpr>(E)) { + D = Send->getMethodDecl(); + } else if (ObjCBoxedExpr *BoxedExpr = dyn_cast<ObjCBoxedExpr>(E)) { + D = BoxedExpr->getBoxingMethod(); + } else if (ObjCArrayLiteral *ArrayLit = dyn_cast<ObjCArrayLiteral>(E)) { + // Don't do reclaims if we're using the zero-element array + // constant. + if (ArrayLit->getNumElements() == 0 && + Context.getLangOpts().ObjCRuntime.hasEmptyCollections()) + return E; + + D = ArrayLit->getArrayWithObjectsMethod(); + } else if (ObjCDictionaryLiteral *DictLit + = dyn_cast<ObjCDictionaryLiteral>(E)) { + // Don't do reclaims if we're using the zero-element dictionary + // constant. + if (DictLit->getNumElements() == 0 && + Context.getLangOpts().ObjCRuntime.hasEmptyCollections()) + return E; + + D = DictLit->getDictWithObjectsMethod(); + } + + ReturnsRetained = (D && D->hasAttr<NSReturnsRetainedAttr>()); + + // Don't do reclaims on performSelector calls; despite their + // return type, the invoked method doesn't necessarily actually + // return an object. + if (!ReturnsRetained && + D && D->getMethodFamily() == OMF_performSelector) + return E; + } + + // Don't reclaim an object of Class type. + if (!ReturnsRetained && E->getType()->isObjCARCImplicitlyUnretainedType()) + return E; + + Cleanup.setExprNeedsCleanups(true); + + CastKind ck = (ReturnsRetained ? CK_ARCConsumeObject + : CK_ARCReclaimReturnedObject); + return ImplicitCastExpr::Create(Context, E->getType(), ck, E, nullptr, + VK_RValue); + } + + if (!getLangOpts().CPlusPlus) + return E; + + // Search for the base element type (cf. ASTContext::getBaseElementType) with + // a fast path for the common case that the type is directly a RecordType. + const Type *T = Context.getCanonicalType(E->getType().getTypePtr()); + const RecordType *RT = nullptr; + while (!RT) { + switch (T->getTypeClass()) { + case Type::Record: + RT = cast<RecordType>(T); + break; + case Type::ConstantArray: + case Type::IncompleteArray: + case Type::VariableArray: + case Type::DependentSizedArray: + T = cast<ArrayType>(T)->getElementType().getTypePtr(); + break; + default: + return E; + } + } + + // That should be enough to guarantee that this type is complete, if we're + // not processing a decltype expression. + CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); + if (RD->isInvalidDecl() || RD->isDependentContext()) + return E; + + bool IsDecltype = ExprEvalContexts.back().ExprContext == + ExpressionEvaluationContextRecord::EK_Decltype; + CXXDestructorDecl *Destructor = IsDecltype ? nullptr : LookupDestructor(RD); + + if (Destructor) { + MarkFunctionReferenced(E->getExprLoc(), Destructor); + CheckDestructorAccess(E->getExprLoc(), Destructor, + PDiag(diag::err_access_dtor_temp) + << E->getType()); + if (DiagnoseUseOfDecl(Destructor, E->getExprLoc())) + return ExprError(); + + // If destructor is trivial, we can avoid the extra copy. + if (Destructor->isTrivial()) + return E; + + // We need a cleanup, but we don't need to remember the temporary. + Cleanup.setExprNeedsCleanups(true); + } + + CXXTemporary *Temp = CXXTemporary::Create(Context, Destructor); + CXXBindTemporaryExpr *Bind = CXXBindTemporaryExpr::Create(Context, Temp, E); + + if (IsDecltype) + ExprEvalContexts.back().DelayedDecltypeBinds.push_back(Bind); + + return Bind; +} + +ExprResult +Sema::MaybeCreateExprWithCleanups(ExprResult SubExpr) { + if (SubExpr.isInvalid()) + return ExprError(); + + return MaybeCreateExprWithCleanups(SubExpr.get()); +} + +Expr *Sema::MaybeCreateExprWithCleanups(Expr *SubExpr) { + assert(SubExpr && "subexpression can't be null!"); + + CleanupVarDeclMarking(); + + unsigned FirstCleanup = ExprEvalContexts.back().NumCleanupObjects; + assert(ExprCleanupObjects.size() >= FirstCleanup); + assert(Cleanup.exprNeedsCleanups() || + ExprCleanupObjects.size() == FirstCleanup); + if (!Cleanup.exprNeedsCleanups()) + return SubExpr; + + auto Cleanups = llvm::makeArrayRef(ExprCleanupObjects.begin() + FirstCleanup, + ExprCleanupObjects.size() - FirstCleanup); + + auto *E = ExprWithCleanups::Create( + Context, SubExpr, Cleanup.cleanupsHaveSideEffects(), Cleanups); + DiscardCleanupsInEvaluationContext(); + + return E; +} + +Stmt *Sema::MaybeCreateStmtWithCleanups(Stmt *SubStmt) { + assert(SubStmt && "sub-statement can't be null!"); + + CleanupVarDeclMarking(); + + if (!Cleanup.exprNeedsCleanups()) + return SubStmt; + + // FIXME: In order to attach the temporaries, wrap the statement into + // a StmtExpr; currently this is only used for asm statements. + // This is hacky, either create a new CXXStmtWithTemporaries statement or + // a new AsmStmtWithTemporaries. + CompoundStmt *CompStmt = CompoundStmt::Create( + Context, SubStmt, SourceLocation(), SourceLocation()); + Expr *E = new (Context) StmtExpr(CompStmt, Context.VoidTy, SourceLocation(), + SourceLocation()); + return MaybeCreateExprWithCleanups(E); +} + +/// Process the expression contained within a decltype. For such expressions, +/// certain semantic checks on temporaries are delayed until this point, and +/// are omitted for the 'topmost' call in the decltype expression. If the +/// topmost call bound a temporary, strip that temporary off the expression. +ExprResult Sema::ActOnDecltypeExpression(Expr *E) { + assert(ExprEvalContexts.back().ExprContext == + ExpressionEvaluationContextRecord::EK_Decltype && + "not in a decltype expression"); + + ExprResult Result = CheckPlaceholderExpr(E); + if (Result.isInvalid()) + return ExprError(); + E = Result.get(); + + // C++11 [expr.call]p11: + // If a function call is a prvalue of object type, + // -- if the function call is either + // -- the operand of a decltype-specifier, or + // -- the right operand of a comma operator that is the operand of a + // decltype-specifier, + // a temporary object is not introduced for the prvalue. + + // Recursively rebuild ParenExprs and comma expressions to strip out the + // outermost CXXBindTemporaryExpr, if any. + if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { + ExprResult SubExpr = ActOnDecltypeExpression(PE->getSubExpr()); + if (SubExpr.isInvalid()) + return ExprError(); + if (SubExpr.get() == PE->getSubExpr()) + return E; + return ActOnParenExpr(PE->getLParen(), PE->getRParen(), SubExpr.get()); + } + if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { + if (BO->getOpcode() == BO_Comma) { + ExprResult RHS = ActOnDecltypeExpression(BO->getRHS()); + if (RHS.isInvalid()) + return ExprError(); + if (RHS.get() == BO->getRHS()) + return E; + return new (Context) BinaryOperator( + BO->getLHS(), RHS.get(), BO_Comma, BO->getType(), BO->getValueKind(), + BO->getObjectKind(), BO->getOperatorLoc(), BO->getFPFeatures()); + } + } + + CXXBindTemporaryExpr *TopBind = dyn_cast<CXXBindTemporaryExpr>(E); + CallExpr *TopCall = TopBind ? dyn_cast<CallExpr>(TopBind->getSubExpr()) + : nullptr; + if (TopCall) + E = TopCall; + else + TopBind = nullptr; + + // Disable the special decltype handling now. + ExprEvalContexts.back().ExprContext = + ExpressionEvaluationContextRecord::EK_Other; + + Result = CheckUnevaluatedOperand(E); + if (Result.isInvalid()) + return ExprError(); + E = Result.get(); + + // In MS mode, don't perform any extra checking of call return types within a + // decltype expression. + if (getLangOpts().MSVCCompat) + return E; + + // Perform the semantic checks we delayed until this point. + for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeCalls.size(); + I != N; ++I) { + CallExpr *Call = ExprEvalContexts.back().DelayedDecltypeCalls[I]; + if (Call == TopCall) + continue; + + if (CheckCallReturnType(Call->getCallReturnType(Context), + Call->getBeginLoc(), Call, Call->getDirectCallee())) + return ExprError(); + } + + // Now all relevant types are complete, check the destructors are accessible + // and non-deleted, and annotate them on the temporaries. + for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeBinds.size(); + I != N; ++I) { + CXXBindTemporaryExpr *Bind = + ExprEvalContexts.back().DelayedDecltypeBinds[I]; + if (Bind == TopBind) + continue; + + CXXTemporary *Temp = Bind->getTemporary(); + + CXXRecordDecl *RD = + Bind->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); + CXXDestructorDecl *Destructor = LookupDestructor(RD); + Temp->setDestructor(Destructor); + + MarkFunctionReferenced(Bind->getExprLoc(), Destructor); + CheckDestructorAccess(Bind->getExprLoc(), Destructor, + PDiag(diag::err_access_dtor_temp) + << Bind->getType()); + if (DiagnoseUseOfDecl(Destructor, Bind->getExprLoc())) + return ExprError(); + + // We need a cleanup, but we don't need to remember the temporary. + Cleanup.setExprNeedsCleanups(true); + } + + // Possibly strip off the top CXXBindTemporaryExpr. + return E; +} + +/// Note a set of 'operator->' functions that were used for a member access. +static void noteOperatorArrows(Sema &S, + ArrayRef<FunctionDecl *> OperatorArrows) { + unsigned SkipStart = OperatorArrows.size(), SkipCount = 0; + // FIXME: Make this configurable? + unsigned Limit = 9; + if (OperatorArrows.size() > Limit) { + // Produce Limit-1 normal notes and one 'skipping' note. + SkipStart = (Limit - 1) / 2 + (Limit - 1) % 2; + SkipCount = OperatorArrows.size() - (Limit - 1); + } + + for (unsigned I = 0; I < OperatorArrows.size(); /**/) { + if (I == SkipStart) { + S.Diag(OperatorArrows[I]->getLocation(), + diag::note_operator_arrows_suppressed) + << SkipCount; + I += SkipCount; + } else { + S.Diag(OperatorArrows[I]->getLocation(), diag::note_operator_arrow_here) + << OperatorArrows[I]->getCallResultType(); + ++I; + } + } +} + +ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base, + SourceLocation OpLoc, + tok::TokenKind OpKind, + ParsedType &ObjectType, + bool &MayBePseudoDestructor) { + // Since this might be a postfix expression, get rid of ParenListExprs. + ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); + if (Result.isInvalid()) return ExprError(); + Base = Result.get(); + + Result = CheckPlaceholderExpr(Base); + if (Result.isInvalid()) return ExprError(); + Base = Result.get(); + + QualType BaseType = Base->getType(); + MayBePseudoDestructor = false; + if (BaseType->isDependentType()) { + // If we have a pointer to a dependent type and are using the -> operator, + // the object type is the type that the pointer points to. We might still + // have enough information about that type to do something useful. + if (OpKind == tok::arrow) + if (const PointerType *Ptr = BaseType->getAs<PointerType>()) + BaseType = Ptr->getPointeeType(); + + ObjectType = ParsedType::make(BaseType); + MayBePseudoDestructor = true; + return Base; + } + + // C++ [over.match.oper]p8: + // [...] When operator->returns, the operator-> is applied to the value + // returned, with the original second operand. + if (OpKind == tok::arrow) { + QualType StartingType = BaseType; + bool NoArrowOperatorFound = false; + bool FirstIteration = true; + FunctionDecl *CurFD = dyn_cast<FunctionDecl>(CurContext); + // The set of types we've considered so far. + llvm::SmallPtrSet<CanQualType,8> CTypes; + SmallVector<FunctionDecl*, 8> OperatorArrows; + CTypes.insert(Context.getCanonicalType(BaseType)); + + while (BaseType->isRecordType()) { + if (OperatorArrows.size() >= getLangOpts().ArrowDepth) { + Diag(OpLoc, diag::err_operator_arrow_depth_exceeded) + << StartingType << getLangOpts().ArrowDepth << Base->getSourceRange(); + noteOperatorArrows(*this, OperatorArrows); + Diag(OpLoc, diag::note_operator_arrow_depth) + << getLangOpts().ArrowDepth; + return ExprError(); + } + + Result = BuildOverloadedArrowExpr( + S, Base, OpLoc, + // When in a template specialization and on the first loop iteration, + // potentially give the default diagnostic (with the fixit in a + // separate note) instead of having the error reported back to here + // and giving a diagnostic with a fixit attached to the error itself. + (FirstIteration && CurFD && CurFD->isFunctionTemplateSpecialization()) + ? nullptr + : &NoArrowOperatorFound); + if (Result.isInvalid()) { + if (NoArrowOperatorFound) { + if (FirstIteration) { + Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) + << BaseType << 1 << Base->getSourceRange() + << FixItHint::CreateReplacement(OpLoc, "."); + OpKind = tok::period; + break; + } + Diag(OpLoc, diag::err_typecheck_member_reference_arrow) + << BaseType << Base->getSourceRange(); + CallExpr *CE = dyn_cast<CallExpr>(Base); + if (Decl *CD = (CE ? CE->getCalleeDecl() : nullptr)) { + Diag(CD->getBeginLoc(), + diag::note_member_reference_arrow_from_operator_arrow); + } + } + return ExprError(); + } + Base = Result.get(); + if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(Base)) + OperatorArrows.push_back(OpCall->getDirectCallee()); + BaseType = Base->getType(); + CanQualType CBaseType = Context.getCanonicalType(BaseType); + if (!CTypes.insert(CBaseType).second) { + Diag(OpLoc, diag::err_operator_arrow_circular) << StartingType; + noteOperatorArrows(*this, OperatorArrows); + return ExprError(); + } + FirstIteration = false; + } + + if (OpKind == tok::arrow) { + if (BaseType->isPointerType()) + BaseType = BaseType->getPointeeType(); + else if (auto *AT = Context.getAsArrayType(BaseType)) + BaseType = AT->getElementType(); + } + } + + // Objective-C properties allow "." access on Objective-C pointer types, + // so adjust the base type to the object type itself. + if (BaseType->isObjCObjectPointerType()) + BaseType = BaseType->getPointeeType(); + + // C++ [basic.lookup.classref]p2: + // [...] If the type of the object expression is of pointer to scalar + // type, the unqualified-id is looked up in the context of the complete + // postfix-expression. + // + // This also indicates that we could be parsing a pseudo-destructor-name. + // Note that Objective-C class and object types can be pseudo-destructor + // expressions or normal member (ivar or property) access expressions, and + // it's legal for the type to be incomplete if this is a pseudo-destructor + // call. We'll do more incomplete-type checks later in the lookup process, + // so just skip this check for ObjC types. + if (!BaseType->isRecordType()) { + ObjectType = ParsedType::make(BaseType); + MayBePseudoDestructor = true; + return Base; + } + + // The object type must be complete (or dependent), or + // C++11 [expr.prim.general]p3: + // Unlike the object expression in other contexts, *this is not required to + // be of complete type for purposes of class member access (5.2.5) outside + // the member function body. + if (!BaseType->isDependentType() && + !isThisOutsideMemberFunctionBody(BaseType) && + RequireCompleteType(OpLoc, BaseType, diag::err_incomplete_member_access)) + return ExprError(); + + // C++ [basic.lookup.classref]p2: + // If the id-expression in a class member access (5.2.5) is an + // unqualified-id, and the type of the object expression is of a class + // type C (or of pointer to a class type C), the unqualified-id is looked + // up in the scope of class C. [...] + ObjectType = ParsedType::make(BaseType); + return Base; +} + +static bool CheckArrow(Sema& S, QualType& ObjectType, Expr *&Base, + tok::TokenKind& OpKind, SourceLocation OpLoc) { + if (Base->hasPlaceholderType()) { + ExprResult result = S.CheckPlaceholderExpr(Base); + if (result.isInvalid()) return true; + Base = result.get(); + } + ObjectType = Base->getType(); + + // C++ [expr.pseudo]p2: + // The left-hand side of the dot operator shall be of scalar type. The + // left-hand side of the arrow operator shall be of pointer to scalar type. + // This scalar type is the object type. + // Note that this is rather different from the normal handling for the + // arrow operator. + if (OpKind == tok::arrow) { + if (const PointerType *Ptr = ObjectType->getAs<PointerType>()) { + ObjectType = Ptr->getPointeeType(); + } else if (!Base->isTypeDependent()) { + // The user wrote "p->" when they probably meant "p."; fix it. + S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) + << ObjectType << true + << FixItHint::CreateReplacement(OpLoc, "."); + if (S.isSFINAEContext()) + return true; + + OpKind = tok::period; + } + } + + return false; +} + +/// Check if it's ok to try and recover dot pseudo destructor calls on +/// pointer objects. +static bool +canRecoverDotPseudoDestructorCallsOnPointerObjects(Sema &SemaRef, + QualType DestructedType) { + // If this is a record type, check if its destructor is callable. + if (auto *RD = DestructedType->getAsCXXRecordDecl()) { + if (RD->hasDefinition()) + if (CXXDestructorDecl *D = SemaRef.LookupDestructor(RD)) + return SemaRef.CanUseDecl(D, /*TreatUnavailableAsInvalid=*/false); + return false; + } + + // Otherwise, check if it's a type for which it's valid to use a pseudo-dtor. + return DestructedType->isDependentType() || DestructedType->isScalarType() || + DestructedType->isVectorType(); +} + +ExprResult Sema::BuildPseudoDestructorExpr(Expr *Base, + SourceLocation OpLoc, + tok::TokenKind OpKind, + const CXXScopeSpec &SS, + TypeSourceInfo *ScopeTypeInfo, + SourceLocation CCLoc, + SourceLocation TildeLoc, + PseudoDestructorTypeStorage Destructed) { + TypeSourceInfo *DestructedTypeInfo = Destructed.getTypeSourceInfo(); + + QualType ObjectType; + if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) + return ExprError(); + + if (!ObjectType->isDependentType() && !ObjectType->isScalarType() && + !ObjectType->isVectorType()) { + if (getLangOpts().MSVCCompat && ObjectType->isVoidType()) + Diag(OpLoc, diag::ext_pseudo_dtor_on_void) << Base->getSourceRange(); + else { + Diag(OpLoc, diag::err_pseudo_dtor_base_not_scalar) + << ObjectType << Base->getSourceRange(); + return ExprError(); + } + } + + // C++ [expr.pseudo]p2: + // [...] The cv-unqualified versions of the object type and of the type + // designated by the pseudo-destructor-name shall be the same type. + if (DestructedTypeInfo) { + QualType DestructedType = DestructedTypeInfo->getType(); + SourceLocation DestructedTypeStart + = DestructedTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(); + if (!DestructedType->isDependentType() && !ObjectType->isDependentType()) { + if (!Context.hasSameUnqualifiedType(DestructedType, ObjectType)) { + // Detect dot pseudo destructor calls on pointer objects, e.g.: + // Foo *foo; + // foo.~Foo(); + if (OpKind == tok::period && ObjectType->isPointerType() && + Context.hasSameUnqualifiedType(DestructedType, + ObjectType->getPointeeType())) { + auto Diagnostic = + Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) + << ObjectType << /*IsArrow=*/0 << Base->getSourceRange(); + + // Issue a fixit only when the destructor is valid. + if (canRecoverDotPseudoDestructorCallsOnPointerObjects( + *this, DestructedType)) + Diagnostic << FixItHint::CreateReplacement(OpLoc, "->"); + + // Recover by setting the object type to the destructed type and the + // operator to '->'. + ObjectType = DestructedType; + OpKind = tok::arrow; + } else { + Diag(DestructedTypeStart, diag::err_pseudo_dtor_type_mismatch) + << ObjectType << DestructedType << Base->getSourceRange() + << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); + + // Recover by setting the destructed type to the object type. + DestructedType = ObjectType; + DestructedTypeInfo = + Context.getTrivialTypeSourceInfo(ObjectType, DestructedTypeStart); + Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); + } + } else if (DestructedType.getObjCLifetime() != + ObjectType.getObjCLifetime()) { + + if (DestructedType.getObjCLifetime() == Qualifiers::OCL_None) { + // Okay: just pretend that the user provided the correctly-qualified + // type. + } else { + Diag(DestructedTypeStart, diag::err_arc_pseudo_dtor_inconstant_quals) + << ObjectType << DestructedType << Base->getSourceRange() + << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); + } + + // Recover by setting the destructed type to the object type. + DestructedType = ObjectType; + DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType, + DestructedTypeStart); + Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); + } + } + } + + // C++ [expr.pseudo]p2: + // [...] Furthermore, the two type-names in a pseudo-destructor-name of the + // form + // + // ::[opt] nested-name-specifier[opt] type-name :: ~ type-name + // + // shall designate the same scalar type. + if (ScopeTypeInfo) { + QualType ScopeType = ScopeTypeInfo->getType(); + if (!ScopeType->isDependentType() && !ObjectType->isDependentType() && + !Context.hasSameUnqualifiedType(ScopeType, ObjectType)) { + + Diag(ScopeTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(), + diag::err_pseudo_dtor_type_mismatch) + << ObjectType << ScopeType << Base->getSourceRange() + << ScopeTypeInfo->getTypeLoc().getLocalSourceRange(); + + ScopeType = QualType(); + ScopeTypeInfo = nullptr; + } + } + + Expr *Result + = new (Context) CXXPseudoDestructorExpr(Context, Base, + OpKind == tok::arrow, OpLoc, + SS.getWithLocInContext(Context), + ScopeTypeInfo, + CCLoc, + TildeLoc, + Destructed); + + return Result; +} + +ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, + SourceLocation OpLoc, + tok::TokenKind OpKind, + CXXScopeSpec &SS, + UnqualifiedId &FirstTypeName, + SourceLocation CCLoc, + SourceLocation TildeLoc, + UnqualifiedId &SecondTypeName) { + assert((FirstTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId || + FirstTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) && + "Invalid first type name in pseudo-destructor"); + assert((SecondTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId || + SecondTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) && + "Invalid second type name in pseudo-destructor"); + + QualType ObjectType; + if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) + return ExprError(); + + // Compute the object type that we should use for name lookup purposes. Only + // record types and dependent types matter. + ParsedType ObjectTypePtrForLookup; + if (!SS.isSet()) { + if (ObjectType->isRecordType()) + ObjectTypePtrForLookup = ParsedType::make(ObjectType); + else if (ObjectType->isDependentType()) + ObjectTypePtrForLookup = ParsedType::make(Context.DependentTy); + } + + // Convert the name of the type being destructed (following the ~) into a + // type (with source-location information). + QualType DestructedType; + TypeSourceInfo *DestructedTypeInfo = nullptr; + PseudoDestructorTypeStorage Destructed; + if (SecondTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) { + ParsedType T = getTypeName(*SecondTypeName.Identifier, + SecondTypeName.StartLocation, + S, &SS, true, false, ObjectTypePtrForLookup, + /*IsCtorOrDtorName*/true); + if (!T && + ((SS.isSet() && !computeDeclContext(SS, false)) || + (!SS.isSet() && ObjectType->isDependentType()))) { + // The name of the type being destroyed is a dependent name, and we + // couldn't find anything useful in scope. Just store the identifier and + // it's location, and we'll perform (qualified) name lookup again at + // template instantiation time. + Destructed = PseudoDestructorTypeStorage(SecondTypeName.Identifier, + SecondTypeName.StartLocation); + } else if (!T) { + Diag(SecondTypeName.StartLocation, + diag::err_pseudo_dtor_destructor_non_type) + << SecondTypeName.Identifier << ObjectType; + if (isSFINAEContext()) + return ExprError(); + + // Recover by assuming we had the right type all along. + DestructedType = ObjectType; + } else + DestructedType = GetTypeFromParser(T, &DestructedTypeInfo); + } else { + // Resolve the template-id to a type. + TemplateIdAnnotation *TemplateId = SecondTypeName.TemplateId; + ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), + TemplateId->NumArgs); + TypeResult T = ActOnTemplateIdType(S, + TemplateId->SS, + TemplateId->TemplateKWLoc, + TemplateId->Template, + TemplateId->Name, + TemplateId->TemplateNameLoc, + TemplateId->LAngleLoc, + TemplateArgsPtr, + TemplateId->RAngleLoc, + /*IsCtorOrDtorName*/true); + if (T.isInvalid() || !T.get()) { + // Recover by assuming we had the right type all along. + DestructedType = ObjectType; + } else + DestructedType = GetTypeFromParser(T.get(), &DestructedTypeInfo); + } + + // If we've performed some kind of recovery, (re-)build the type source + // information. + if (!DestructedType.isNull()) { + if (!DestructedTypeInfo) + DestructedTypeInfo = Context.getTrivialTypeSourceInfo(DestructedType, + SecondTypeName.StartLocation); + Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); + } + + // Convert the name of the scope type (the type prior to '::') into a type. + TypeSourceInfo *ScopeTypeInfo = nullptr; + QualType ScopeType; + if (FirstTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId || + FirstTypeName.Identifier) { + if (FirstTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) { + ParsedType T = getTypeName(*FirstTypeName.Identifier, + FirstTypeName.StartLocation, + S, &SS, true, false, ObjectTypePtrForLookup, + /*IsCtorOrDtorName*/true); + if (!T) { + Diag(FirstTypeName.StartLocation, + diag::err_pseudo_dtor_destructor_non_type) + << FirstTypeName.Identifier << ObjectType; + + if (isSFINAEContext()) + return ExprError(); + + // Just drop this type. It's unnecessary anyway. + ScopeType = QualType(); + } else + ScopeType = GetTypeFromParser(T, &ScopeTypeInfo); + } else { + // Resolve the template-id to a type. + TemplateIdAnnotation *TemplateId = FirstTypeName.TemplateId; + ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), + TemplateId->NumArgs); + TypeResult T = ActOnTemplateIdType(S, + TemplateId->SS, + TemplateId->TemplateKWLoc, + TemplateId->Template, + TemplateId->Name, + TemplateId->TemplateNameLoc, + TemplateId->LAngleLoc, + TemplateArgsPtr, + TemplateId->RAngleLoc, + /*IsCtorOrDtorName*/true); + if (T.isInvalid() || !T.get()) { + // Recover by dropping this type. + ScopeType = QualType(); + } else + ScopeType = GetTypeFromParser(T.get(), &ScopeTypeInfo); + } + } + + if (!ScopeType.isNull() && !ScopeTypeInfo) + ScopeTypeInfo = Context.getTrivialTypeSourceInfo(ScopeType, + FirstTypeName.StartLocation); + + + return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, SS, + ScopeTypeInfo, CCLoc, TildeLoc, + Destructed); +} + +ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, + SourceLocation OpLoc, + tok::TokenKind OpKind, + SourceLocation TildeLoc, + const DeclSpec& DS) { + QualType ObjectType; + if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) + return ExprError(); + + QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc(), + false); + + TypeLocBuilder TLB; + DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T); + DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc()); + TypeSourceInfo *DestructedTypeInfo = TLB.getTypeSourceInfo(Context, T); + PseudoDestructorTypeStorage Destructed(DestructedTypeInfo); + + return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, CXXScopeSpec(), + nullptr, SourceLocation(), TildeLoc, + Destructed); +} + +ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl, + CXXConversionDecl *Method, + bool HadMultipleCandidates) { + // Convert the expression to match the conversion function's implicit object + // parameter. + ExprResult Exp = PerformObjectArgumentInitialization(E, /*Qualifier=*/nullptr, + FoundDecl, Method); + if (Exp.isInvalid()) + return true; + + if (Method->getParent()->isLambda() && + Method->getConversionType()->isBlockPointerType()) { + // This is a lambda conversion to block pointer; check if the argument + // was a LambdaExpr. + Expr *SubE = E; + CastExpr *CE = dyn_cast<CastExpr>(SubE); + if (CE && CE->getCastKind() == CK_NoOp) + SubE = CE->getSubExpr(); + SubE = SubE->IgnoreParens(); + if (CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(SubE)) + SubE = BE->getSubExpr(); + if (isa<LambdaExpr>(SubE)) { + // For the conversion to block pointer on a lambda expression, we + // construct a special BlockLiteral instead; this doesn't really make + // a difference in ARC, but outside of ARC the resulting block literal + // follows the normal lifetime rules for block literals instead of being + // autoreleased. + DiagnosticErrorTrap Trap(Diags); + PushExpressionEvaluationContext( + ExpressionEvaluationContext::PotentiallyEvaluated); + ExprResult BlockExp = BuildBlockForLambdaConversion( + Exp.get()->getExprLoc(), Exp.get()->getExprLoc(), Method, Exp.get()); + PopExpressionEvaluationContext(); + + if (BlockExp.isInvalid()) + Diag(Exp.get()->getExprLoc(), diag::note_lambda_to_block_conv); + return BlockExp; + } + } + + MemberExpr *ME = + BuildMemberExpr(Exp.get(), /*IsArrow=*/false, SourceLocation(), + NestedNameSpecifierLoc(), SourceLocation(), Method, + DeclAccessPair::make(FoundDecl, FoundDecl->getAccess()), + HadMultipleCandidates, DeclarationNameInfo(), + Context.BoundMemberTy, VK_RValue, OK_Ordinary); + + QualType ResultType = Method->getReturnType(); + ExprValueKind VK = Expr::getValueKindForType(ResultType); + ResultType = ResultType.getNonLValueExprType(Context); + + CXXMemberCallExpr *CE = CXXMemberCallExpr::Create( + Context, ME, /*Args=*/{}, ResultType, VK, Exp.get()->getEndLoc()); + + if (CheckFunctionCall(Method, CE, + Method->getType()->castAs<FunctionProtoType>())) + return ExprError(); + + return CE; +} + +ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand, + SourceLocation RParen) { + // If the operand is an unresolved lookup expression, the expression is ill- + // formed per [over.over]p1, because overloaded function names cannot be used + // without arguments except in explicit contexts. + ExprResult R = CheckPlaceholderExpr(Operand); + if (R.isInvalid()) + return R; + + R = CheckUnevaluatedOperand(R.get()); + if (R.isInvalid()) + return ExprError(); + + Operand = R.get(); + + if (!inTemplateInstantiation() && Operand->HasSideEffects(Context, false)) { + // The expression operand for noexcept is in an unevaluated expression + // context, so side effects could result in unintended consequences. + Diag(Operand->getExprLoc(), diag::warn_side_effects_unevaluated_context); + } + + CanThrowResult CanThrow = canThrow(Operand); + return new (Context) + CXXNoexceptExpr(Context.BoolTy, Operand, CanThrow, KeyLoc, RParen); +} + +ExprResult Sema::ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation, + Expr *Operand, SourceLocation RParen) { + return BuildCXXNoexceptExpr(KeyLoc, Operand, RParen); +} + +static bool IsSpecialDiscardedValue(Expr *E) { + // In C++11, discarded-value expressions of a certain form are special, + // according to [expr]p10: + // The lvalue-to-rvalue conversion (4.1) is applied only if the + // expression is an lvalue of volatile-qualified type and it has + // one of the following forms: + E = E->IgnoreParens(); + + // - id-expression (5.1.1), + if (isa<DeclRefExpr>(E)) + return true; + + // - subscripting (5.2.1), + if (isa<ArraySubscriptExpr>(E)) + return true; + + // - class member access (5.2.5), + if (isa<MemberExpr>(E)) + return true; + + // - indirection (5.3.1), + if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) + if (UO->getOpcode() == UO_Deref) + return true; + + if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { + // - pointer-to-member operation (5.5), + if (BO->isPtrMemOp()) + return true; + + // - comma expression (5.18) where the right operand is one of the above. + if (BO->getOpcode() == BO_Comma) + return IsSpecialDiscardedValue(BO->getRHS()); + } + + // - conditional expression (5.16) where both the second and the third + // operands are one of the above, or + if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) + return IsSpecialDiscardedValue(CO->getTrueExpr()) && + IsSpecialDiscardedValue(CO->getFalseExpr()); + // The related edge case of "*x ?: *x". + if (BinaryConditionalOperator *BCO = + dyn_cast<BinaryConditionalOperator>(E)) { + if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(BCO->getTrueExpr())) + return IsSpecialDiscardedValue(OVE->getSourceExpr()) && + IsSpecialDiscardedValue(BCO->getFalseExpr()); + } + + // Objective-C++ extensions to the rule. + if (isa<PseudoObjectExpr>(E) || isa<ObjCIvarRefExpr>(E)) + return true; + + return false; +} + +/// Perform the conversions required for an expression used in a +/// context that ignores the result. +ExprResult Sema::IgnoredValueConversions(Expr *E) { + if (E->hasPlaceholderType()) { + ExprResult result = CheckPlaceholderExpr(E); + if (result.isInvalid()) return E; + E = result.get(); + } + + // C99 6.3.2.1: + // [Except in specific positions,] an lvalue that does not have + // array type is converted to the value stored in the + // designated object (and is no longer an lvalue). + if (E->isRValue()) { + // In C, function designators (i.e. expressions of function type) + // are r-values, but we still want to do function-to-pointer decay + // on them. This is both technically correct and convenient for + // some clients. + if (!getLangOpts().CPlusPlus && E->getType()->isFunctionType()) + return DefaultFunctionArrayConversion(E); + + return E; + } + + if (getLangOpts().CPlusPlus) { + // The C++11 standard defines the notion of a discarded-value expression; + // normally, we don't need to do anything to handle it, but if it is a + // volatile lvalue with a special form, we perform an lvalue-to-rvalue + // conversion. + if (getLangOpts().CPlusPlus11 && E->isGLValue() && + E->getType().isVolatileQualified()) { + if (IsSpecialDiscardedValue(E)) { + ExprResult Res = DefaultLvalueConversion(E); + if (Res.isInvalid()) + return E; + E = Res.get(); + } else { + // Per C++2a [expr.ass]p5, a volatile assignment is not deprecated if + // it occurs as a discarded-value expression. + CheckUnusedVolatileAssignment(E); + } + } + + // C++1z: + // If the expression is a prvalue after this optional conversion, the + // temporary materialization conversion is applied. + // + // We skip this step: IR generation is able to synthesize the storage for + // itself in the aggregate case, and adding the extra node to the AST is + // just clutter. + // FIXME: We don't emit lifetime markers for the temporaries due to this. + // FIXME: Do any other AST consumers care about this? + return E; + } + + // GCC seems to also exclude expressions of incomplete enum type. + if (const EnumType *T = E->getType()->getAs<EnumType>()) { + if (!T->getDecl()->isComplete()) { + // FIXME: stupid workaround for a codegen bug! + E = ImpCastExprToType(E, Context.VoidTy, CK_ToVoid).get(); + return E; + } + } + + ExprResult Res = DefaultFunctionArrayLvalueConversion(E); + if (Res.isInvalid()) + return E; + E = Res.get(); + + if (!E->getType()->isVoidType()) + RequireCompleteType(E->getExprLoc(), E->getType(), + diag::err_incomplete_type); + return E; +} + +ExprResult Sema::CheckUnevaluatedOperand(Expr *E) { + // Per C++2a [expr.ass]p5, a volatile assignment is not deprecated if + // it occurs as an unevaluated operand. + CheckUnusedVolatileAssignment(E); + + return E; +} + +// If we can unambiguously determine whether Var can never be used +// in a constant expression, return true. +// - if the variable and its initializer are non-dependent, then +// we can unambiguously check if the variable is a constant expression. +// - if the initializer is not value dependent - we can determine whether +// it can be used to initialize a constant expression. If Init can not +// be used to initialize a constant expression we conclude that Var can +// never be a constant expression. +// - FXIME: if the initializer is dependent, we can still do some analysis and +// identify certain cases unambiguously as non-const by using a Visitor: +// - such as those that involve odr-use of a ParmVarDecl, involve a new +// delete, lambda-expr, dynamic-cast, reinterpret-cast etc... +static inline bool VariableCanNeverBeAConstantExpression(VarDecl *Var, + ASTContext &Context) { + if (isa<ParmVarDecl>(Var)) return true; + const VarDecl *DefVD = nullptr; + + // If there is no initializer - this can not be a constant expression. + if (!Var->getAnyInitializer(DefVD)) return true; + assert(DefVD); + if (DefVD->isWeak()) return false; + EvaluatedStmt *Eval = DefVD->ensureEvaluatedStmt(); + + Expr *Init = cast<Expr>(Eval->Value); + + if (Var->getType()->isDependentType() || Init->isValueDependent()) { + // FIXME: Teach the constant evaluator to deal with the non-dependent parts + // of value-dependent expressions, and use it here to determine whether the + // initializer is a potential constant expression. + return false; + } + + return !Var->isUsableInConstantExpressions(Context); +} + +/// Check if the current lambda has any potential captures +/// that must be captured by any of its enclosing lambdas that are ready to +/// capture. If there is a lambda that can capture a nested +/// potential-capture, go ahead and do so. Also, check to see if any +/// variables are uncaptureable or do not involve an odr-use so do not +/// need to be captured. + +static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures( + Expr *const FE, LambdaScopeInfo *const CurrentLSI, Sema &S) { + + assert(!S.isUnevaluatedContext()); + assert(S.CurContext->isDependentContext()); +#ifndef NDEBUG + DeclContext *DC = S.CurContext; + while (DC && isa<CapturedDecl>(DC)) + DC = DC->getParent(); + assert( + CurrentLSI->CallOperator == DC && + "The current call operator must be synchronized with Sema's CurContext"); +#endif // NDEBUG + + const bool IsFullExprInstantiationDependent = FE->isInstantiationDependent(); + + // All the potentially captureable variables in the current nested + // lambda (within a generic outer lambda), must be captured by an + // outer lambda that is enclosed within a non-dependent context. + CurrentLSI->visitPotentialCaptures([&] (VarDecl *Var, Expr *VarExpr) { + // If the variable is clearly identified as non-odr-used and the full + // expression is not instantiation dependent, only then do we not + // need to check enclosing lambda's for speculative captures. + // For e.g.: + // Even though 'x' is not odr-used, it should be captured. + // int test() { + // const int x = 10; + // auto L = [=](auto a) { + // (void) +x + a; + // }; + // } + if (CurrentLSI->isVariableExprMarkedAsNonODRUsed(VarExpr) && + !IsFullExprInstantiationDependent) + return; + + // If we have a capture-capable lambda for the variable, go ahead and + // capture the variable in that lambda (and all its enclosing lambdas). + if (const Optional<unsigned> Index = + getStackIndexOfNearestEnclosingCaptureCapableLambda( + S.FunctionScopes, Var, S)) + S.MarkCaptureUsedInEnclosingContext(Var, VarExpr->getExprLoc(), + Index.getValue()); + const bool IsVarNeverAConstantExpression = + VariableCanNeverBeAConstantExpression(Var, S.Context); + if (!IsFullExprInstantiationDependent || IsVarNeverAConstantExpression) { + // This full expression is not instantiation dependent or the variable + // can not be used in a constant expression - which means + // this variable must be odr-used here, so diagnose a + // capture violation early, if the variable is un-captureable. + // This is purely for diagnosing errors early. Otherwise, this + // error would get diagnosed when the lambda becomes capture ready. + QualType CaptureType, DeclRefType; + SourceLocation ExprLoc = VarExpr->getExprLoc(); + if (S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit, + /*EllipsisLoc*/ SourceLocation(), + /*BuildAndDiagnose*/false, CaptureType, + DeclRefType, nullptr)) { + // We will never be able to capture this variable, and we need + // to be able to in any and all instantiations, so diagnose it. + S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit, + /*EllipsisLoc*/ SourceLocation(), + /*BuildAndDiagnose*/true, CaptureType, + DeclRefType, nullptr); + } + } + }); + + // Check if 'this' needs to be captured. + if (CurrentLSI->hasPotentialThisCapture()) { + // If we have a capture-capable lambda for 'this', go ahead and capture + // 'this' in that lambda (and all its enclosing lambdas). + if (const Optional<unsigned> Index = + getStackIndexOfNearestEnclosingCaptureCapableLambda( + S.FunctionScopes, /*0 is 'this'*/ nullptr, S)) { + const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue(); + S.CheckCXXThisCapture(CurrentLSI->PotentialThisCaptureLocation, + /*Explicit*/ false, /*BuildAndDiagnose*/ true, + &FunctionScopeIndexOfCapturableLambda); + } + } + + // Reset all the potential captures at the end of each full-expression. + CurrentLSI->clearPotentialCaptures(); +} + +static ExprResult attemptRecovery(Sema &SemaRef, + const TypoCorrectionConsumer &Consumer, + const TypoCorrection &TC) { + LookupResult R(SemaRef, Consumer.getLookupResult().getLookupNameInfo(), + Consumer.getLookupResult().getLookupKind()); + const CXXScopeSpec *SS = Consumer.getSS(); + CXXScopeSpec NewSS; + + // Use an approprate CXXScopeSpec for building the expr. + if (auto *NNS = TC.getCorrectionSpecifier()) + NewSS.MakeTrivial(SemaRef.Context, NNS, TC.getCorrectionRange()); + else if (SS && !TC.WillReplaceSpecifier()) + NewSS = *SS; + + if (auto *ND = TC.getFoundDecl()) { + R.setLookupName(ND->getDeclName()); + R.addDecl(ND); + if (ND->isCXXClassMember()) { + // Figure out the correct naming class to add to the LookupResult. + CXXRecordDecl *Record = nullptr; + if (auto *NNS = TC.getCorrectionSpecifier()) + Record = NNS->getAsType()->getAsCXXRecordDecl(); + if (!Record) + Record = + dyn_cast<CXXRecordDecl>(ND->getDeclContext()->getRedeclContext()); + if (Record) + R.setNamingClass(Record); + + // Detect and handle the case where the decl might be an implicit + // member. + bool MightBeImplicitMember; + if (!Consumer.isAddressOfOperand()) + MightBeImplicitMember = true; + else if (!NewSS.isEmpty()) + MightBeImplicitMember = false; + else if (R.isOverloadedResult()) + MightBeImplicitMember = false; + else if (R.isUnresolvableResult()) + MightBeImplicitMember = true; + else + MightBeImplicitMember = isa<FieldDecl>(ND) || + isa<IndirectFieldDecl>(ND) || + isa<MSPropertyDecl>(ND); + + if (MightBeImplicitMember) + return SemaRef.BuildPossibleImplicitMemberExpr( + NewSS, /*TemplateKWLoc*/ SourceLocation(), R, + /*TemplateArgs*/ nullptr, /*S*/ nullptr); + } else if (auto *Ivar = dyn_cast<ObjCIvarDecl>(ND)) { + return SemaRef.LookupInObjCMethod(R, Consumer.getScope(), + Ivar->getIdentifier()); + } + } + + return SemaRef.BuildDeclarationNameExpr(NewSS, R, /*NeedsADL*/ false, + /*AcceptInvalidDecl*/ true); +} + +namespace { +class FindTypoExprs : public RecursiveASTVisitor<FindTypoExprs> { + llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs; + +public: + explicit FindTypoExprs(llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs) + : TypoExprs(TypoExprs) {} + bool VisitTypoExpr(TypoExpr *TE) { + TypoExprs.insert(TE); + return true; + } +}; + +class TransformTypos : public TreeTransform<TransformTypos> { + typedef TreeTransform<TransformTypos> BaseTransform; + + VarDecl *InitDecl; // A decl to avoid as a correction because it is in the + // process of being initialized. + llvm::function_ref<ExprResult(Expr *)> ExprFilter; + llvm::SmallSetVector<TypoExpr *, 2> TypoExprs, AmbiguousTypoExprs; + llvm::SmallDenseMap<TypoExpr *, ExprResult, 2> TransformCache; + llvm::SmallDenseMap<OverloadExpr *, Expr *, 4> OverloadResolution; + + /// Emit diagnostics for all of the TypoExprs encountered. + /// + /// If the TypoExprs were successfully corrected, then the diagnostics should + /// suggest the corrections. Otherwise the diagnostics will not suggest + /// anything (having been passed an empty TypoCorrection). + /// + /// If we've failed to correct due to ambiguous corrections, we need to + /// be sure to pass empty corrections and replacements. Otherwise it's + /// possible that the Consumer has a TypoCorrection that failed to ambiguity + /// and we don't want to report those diagnostics. + void EmitAllDiagnostics(bool IsAmbiguous) { + for (TypoExpr *TE : TypoExprs) { + auto &State = SemaRef.getTypoExprState(TE); + if (State.DiagHandler) { + TypoCorrection TC = IsAmbiguous + ? TypoCorrection() : State.Consumer->getCurrentCorrection(); + ExprResult Replacement = IsAmbiguous ? ExprError() : TransformCache[TE]; + + // Extract the NamedDecl from the transformed TypoExpr and add it to the + // TypoCorrection, replacing the existing decls. This ensures the right + // NamedDecl is used in diagnostics e.g. in the case where overload + // resolution was used to select one from several possible decls that + // had been stored in the TypoCorrection. + if (auto *ND = getDeclFromExpr( + Replacement.isInvalid() ? nullptr : Replacement.get())) + TC.setCorrectionDecl(ND); + + State.DiagHandler(TC); + } + SemaRef.clearDelayedTypo(TE); + } + } + + /// If corrections for the first TypoExpr have been exhausted for a + /// given combination of the other TypoExprs, retry those corrections against + /// the next combination of substitutions for the other TypoExprs by advancing + /// to the next potential correction of the second TypoExpr. For the second + /// and subsequent TypoExprs, if its stream of corrections has been exhausted, + /// the stream is reset and the next TypoExpr's stream is advanced by one (a + /// TypoExpr's correction stream is advanced by removing the TypoExpr from the + /// TransformCache). Returns true if there is still any untried combinations + /// of corrections. + bool CheckAndAdvanceTypoExprCorrectionStreams() { + for (auto TE : TypoExprs) { + auto &State = SemaRef.getTypoExprState(TE); + TransformCache.erase(TE); + if (!State.Consumer->finished()) + return true; + State.Consumer->resetCorrectionStream(); + } + return false; + } + + NamedDecl *getDeclFromExpr(Expr *E) { + if (auto *OE = dyn_cast_or_null<OverloadExpr>(E)) + E = OverloadResolution[OE]; + + if (!E) + return nullptr; + if (auto *DRE = dyn_cast<DeclRefExpr>(E)) + return DRE->getFoundDecl(); + if (auto *ME = dyn_cast<MemberExpr>(E)) + return ME->getFoundDecl(); + // FIXME: Add any other expr types that could be be seen by the delayed typo + // correction TreeTransform for which the corresponding TypoCorrection could + // contain multiple decls. + return nullptr; + } + + ExprResult TryTransform(Expr *E) { + Sema::SFINAETrap Trap(SemaRef); + ExprResult Res = TransformExpr(E); + if (Trap.hasErrorOccurred() || Res.isInvalid()) + return ExprError(); + + return ExprFilter(Res.get()); + } + + // Since correcting typos may intoduce new TypoExprs, this function + // checks for new TypoExprs and recurses if it finds any. Note that it will + // only succeed if it is able to correct all typos in the given expression. + ExprResult CheckForRecursiveTypos(ExprResult Res, bool &IsAmbiguous) { + if (Res.isInvalid()) { + return Res; + } + // Check to see if any new TypoExprs were created. If so, we need to recurse + // to check their validity. + Expr *FixedExpr = Res.get(); + + auto SavedTypoExprs = std::move(TypoExprs); + auto SavedAmbiguousTypoExprs = std::move(AmbiguousTypoExprs); + TypoExprs.clear(); + AmbiguousTypoExprs.clear(); + + FindTypoExprs(TypoExprs).TraverseStmt(FixedExpr); + if (!TypoExprs.empty()) { + // Recurse to handle newly created TypoExprs. If we're not able to + // handle them, discard these TypoExprs. + ExprResult RecurResult = + RecursiveTransformLoop(FixedExpr, IsAmbiguous); + if (RecurResult.isInvalid()) { + Res = ExprError(); + // Recursive corrections didn't work, wipe them away and don't add + // them to the TypoExprs set. Remove them from Sema's TypoExpr list + // since we don't want to clear them twice. Note: it's possible the + // TypoExprs were created recursively and thus won't be in our + // Sema's TypoExprs - they were created in our `RecursiveTransformLoop`. + auto &SemaTypoExprs = SemaRef.TypoExprs; + for (auto TE : TypoExprs) { + TransformCache.erase(TE); + SemaRef.clearDelayedTypo(TE); + + auto SI = find(SemaTypoExprs, TE); + if (SI != SemaTypoExprs.end()) { + SemaTypoExprs.erase(SI); + } + } + } else { + // TypoExpr is valid: add newly created TypoExprs since we were + // able to correct them. + Res = RecurResult; + SavedTypoExprs.set_union(TypoExprs); + } + } + + TypoExprs = std::move(SavedTypoExprs); + AmbiguousTypoExprs = std::move(SavedAmbiguousTypoExprs); + + return Res; + } + + // Try to transform the given expression, looping through the correction + // candidates with `CheckAndAdvanceTypoExprCorrectionStreams`. + // + // If valid ambiguous typo corrections are seen, `IsAmbiguous` is set to + // true and this method immediately will return an `ExprError`. + ExprResult RecursiveTransformLoop(Expr *E, bool &IsAmbiguous) { + ExprResult Res; + auto SavedTypoExprs = std::move(SemaRef.TypoExprs); + SemaRef.TypoExprs.clear(); + + while (true) { + Res = CheckForRecursiveTypos(TryTransform(E), IsAmbiguous); + + // Recursion encountered an ambiguous correction. This means that our + // correction itself is ambiguous, so stop now. + if (IsAmbiguous) + break; + + // If the transform is still valid after checking for any new typos, + // it's good to go. + if (!Res.isInvalid()) + break; + + // The transform was invalid, see if we have any TypoExprs with untried + // correction candidates. + if (!CheckAndAdvanceTypoExprCorrectionStreams()) + break; + } + + // If we found a valid result, double check to make sure it's not ambiguous. + if (!IsAmbiguous && !Res.isInvalid() && !AmbiguousTypoExprs.empty()) { + auto SavedTransformCache = std::move(TransformCache); + TransformCache.clear(); + // Ensure none of the TypoExprs have multiple typo correction candidates + // with the same edit length that pass all the checks and filters. + while (!AmbiguousTypoExprs.empty()) { + auto TE = AmbiguousTypoExprs.back(); + + // TryTransform itself can create new Typos, adding them to the TypoExpr map + // and invalidating our TypoExprState, so always fetch it instead of storing. + SemaRef.getTypoExprState(TE).Consumer->saveCurrentPosition(); + + TypoCorrection TC = SemaRef.getTypoExprState(TE).Consumer->peekNextCorrection(); + TypoCorrection Next; + do { + // Fetch the next correction by erasing the typo from the cache and calling + // `TryTransform` which will iterate through corrections in + // `TransformTypoExpr`. + TransformCache.erase(TE); + ExprResult AmbigRes = CheckForRecursiveTypos(TryTransform(E), IsAmbiguous); + + if (!AmbigRes.isInvalid() || IsAmbiguous) { + SemaRef.getTypoExprState(TE).Consumer->resetCorrectionStream(); + SavedTransformCache.erase(TE); + Res = ExprError(); + IsAmbiguous = true; + break; + } + } while ((Next = SemaRef.getTypoExprState(TE).Consumer->peekNextCorrection()) && + Next.getEditDistance(false) == TC.getEditDistance(false)); + + if (IsAmbiguous) + break; + + AmbiguousTypoExprs.remove(TE); + SemaRef.getTypoExprState(TE).Consumer->restoreSavedPosition(); + } + TransformCache = std::move(SavedTransformCache); + } + + // Wipe away any newly created TypoExprs that we don't know about. Since we + // clear any invalid TypoExprs in `CheckForRecursiveTypos`, this is only + // possible if a `TypoExpr` is created during a transformation but then + // fails before we can discover it. + auto &SemaTypoExprs = SemaRef.TypoExprs; + for (auto Iterator = SemaTypoExprs.begin(); Iterator != SemaTypoExprs.end();) { + auto TE = *Iterator; + auto FI = find(TypoExprs, TE); + if (FI != TypoExprs.end()) { + Iterator++; + continue; + } + SemaRef.clearDelayedTypo(TE); + Iterator = SemaTypoExprs.erase(Iterator); + } + SemaRef.TypoExprs = std::move(SavedTypoExprs); + + return Res; + } + +public: + TransformTypos(Sema &SemaRef, VarDecl *InitDecl, llvm::function_ref<ExprResult(Expr *)> Filter) + : BaseTransform(SemaRef), InitDecl(InitDecl), ExprFilter(Filter) {} + + ExprResult RebuildCallExpr(Expr *Callee, SourceLocation LParenLoc, + MultiExprArg Args, + SourceLocation RParenLoc, + Expr *ExecConfig = nullptr) { + auto Result = BaseTransform::RebuildCallExpr(Callee, LParenLoc, Args, + RParenLoc, ExecConfig); + if (auto *OE = dyn_cast<OverloadExpr>(Callee)) { + if (Result.isUsable()) { + Expr *ResultCall = Result.get(); + if (auto *BE = dyn_cast<CXXBindTemporaryExpr>(ResultCall)) + ResultCall = BE->getSubExpr(); + if (auto *CE = dyn_cast<CallExpr>(ResultCall)) + OverloadResolution[OE] = CE->getCallee(); + } + } + return Result; + } + + ExprResult TransformLambdaExpr(LambdaExpr *E) { return Owned(E); } + + ExprResult TransformBlockExpr(BlockExpr *E) { return Owned(E); } + + ExprResult Transform(Expr *E) { + bool IsAmbiguous = false; + ExprResult Res = RecursiveTransformLoop(E, IsAmbiguous); + + if (!Res.isUsable()) + FindTypoExprs(TypoExprs).TraverseStmt(E); + + EmitAllDiagnostics(IsAmbiguous); + + return Res; + } + + ExprResult TransformTypoExpr(TypoExpr *E) { + // If the TypoExpr hasn't been seen before, record it. Otherwise, return the + // cached transformation result if there is one and the TypoExpr isn't the + // first one that was encountered. + auto &CacheEntry = TransformCache[E]; + if (!TypoExprs.insert(E) && !CacheEntry.isUnset()) { + return CacheEntry; + } + + auto &State = SemaRef.getTypoExprState(E); + assert(State.Consumer && "Cannot transform a cleared TypoExpr"); + + // For the first TypoExpr and an uncached TypoExpr, find the next likely + // typo correction and return it. + while (TypoCorrection TC = State.Consumer->getNextCorrection()) { + if (InitDecl && TC.getFoundDecl() == InitDecl) + continue; + // FIXME: If we would typo-correct to an invalid declaration, it's + // probably best to just suppress all errors from this typo correction. + ExprResult NE = State.RecoveryHandler ? + State.RecoveryHandler(SemaRef, E, TC) : + attemptRecovery(SemaRef, *State.Consumer, TC); + if (!NE.isInvalid()) { + // Check whether there may be a second viable correction with the same + // edit distance; if so, remember this TypoExpr may have an ambiguous + // correction so it can be more thoroughly vetted later. + TypoCorrection Next; + if ((Next = State.Consumer->peekNextCorrection()) && + Next.getEditDistance(false) == TC.getEditDistance(false)) { + AmbiguousTypoExprs.insert(E); + } else { + AmbiguousTypoExprs.remove(E); + } + assert(!NE.isUnset() && + "Typo was transformed into a valid-but-null ExprResult"); + return CacheEntry = NE; + } + } + return CacheEntry = ExprError(); + } +}; +} + +ExprResult +Sema::CorrectDelayedTyposInExpr(Expr *E, VarDecl *InitDecl, + llvm::function_ref<ExprResult(Expr *)> Filter) { + // If the current evaluation context indicates there are uncorrected typos + // and the current expression isn't guaranteed to not have typos, try to + // resolve any TypoExpr nodes that might be in the expression. + if (E && !ExprEvalContexts.empty() && ExprEvalContexts.back().NumTypos && + (E->isTypeDependent() || E->isValueDependent() || + E->isInstantiationDependent())) { + auto TyposResolved = DelayedTypos.size(); + auto Result = TransformTypos(*this, InitDecl, Filter).Transform(E); + TyposResolved -= DelayedTypos.size(); + if (Result.isInvalid() || Result.get() != E) { + ExprEvalContexts.back().NumTypos -= TyposResolved; + return Result; + } + assert(TyposResolved == 0 && "Corrected typo but got same Expr back?"); + } + return E; +} + +ExprResult Sema::ActOnFinishFullExpr(Expr *FE, SourceLocation CC, + bool DiscardedValue, + bool IsConstexpr) { + ExprResult FullExpr = FE; + + if (!FullExpr.get()) + return ExprError(); + + if (DiagnoseUnexpandedParameterPack(FullExpr.get())) + return ExprError(); + + if (DiscardedValue) { + // Top-level expressions default to 'id' when we're in a debugger. + if (getLangOpts().DebuggerCastResultToId && + FullExpr.get()->getType() == Context.UnknownAnyTy) { + FullExpr = forceUnknownAnyToType(FullExpr.get(), Context.getObjCIdType()); + if (FullExpr.isInvalid()) + return ExprError(); + } + + FullExpr = CheckPlaceholderExpr(FullExpr.get()); + if (FullExpr.isInvalid()) + return ExprError(); + + FullExpr = IgnoredValueConversions(FullExpr.get()); + if (FullExpr.isInvalid()) + return ExprError(); + + DiagnoseUnusedExprResult(FullExpr.get()); + } + + FullExpr = CorrectDelayedTyposInExpr(FullExpr.get()); + if (FullExpr.isInvalid()) + return ExprError(); + + CheckCompletedExpr(FullExpr.get(), CC, IsConstexpr); + + // At the end of this full expression (which could be a deeply nested + // lambda), if there is a potential capture within the nested lambda, + // have the outer capture-able lambda try and capture it. + // Consider the following code: + // void f(int, int); + // void f(const int&, double); + // void foo() { + // const int x = 10, y = 20; + // auto L = [=](auto a) { + // auto M = [=](auto b) { + // f(x, b); <-- requires x to be captured by L and M + // f(y, a); <-- requires y to be captured by L, but not all Ms + // }; + // }; + // } + + // FIXME: Also consider what happens for something like this that involves + // the gnu-extension statement-expressions or even lambda-init-captures: + // void f() { + // const int n = 0; + // auto L = [&](auto a) { + // +n + ({ 0; a; }); + // }; + // } + // + // Here, we see +n, and then the full-expression 0; ends, so we don't + // capture n (and instead remove it from our list of potential captures), + // and then the full-expression +n + ({ 0; }); ends, but it's too late + // for us to see that we need to capture n after all. + + LambdaScopeInfo *const CurrentLSI = + getCurLambda(/*IgnoreCapturedRegions=*/true); + // FIXME: PR 17877 showed that getCurLambda() can return a valid pointer + // even if CurContext is not a lambda call operator. Refer to that Bug Report + // for an example of the code that might cause this asynchrony. + // By ensuring we are in the context of a lambda's call operator + // we can fix the bug (we only need to check whether we need to capture + // if we are within a lambda's body); but per the comments in that + // PR, a proper fix would entail : + // "Alternative suggestion: + // - Add to Sema an integer holding the smallest (outermost) scope + // index that we are *lexically* within, and save/restore/set to + // FunctionScopes.size() in InstantiatingTemplate's + // constructor/destructor. + // - Teach the handful of places that iterate over FunctionScopes to + // stop at the outermost enclosing lexical scope." + DeclContext *DC = CurContext; + while (DC && isa<CapturedDecl>(DC)) + DC = DC->getParent(); + const bool IsInLambdaDeclContext = isLambdaCallOperator(DC); + if (IsInLambdaDeclContext && CurrentLSI && + CurrentLSI->hasPotentialCaptures() && !FullExpr.isInvalid()) + CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(FE, CurrentLSI, + *this); + return MaybeCreateExprWithCleanups(FullExpr); +} + +StmtResult Sema::ActOnFinishFullStmt(Stmt *FullStmt) { + if (!FullStmt) return StmtError(); + + return MaybeCreateStmtWithCleanups(FullStmt); +} + +Sema::IfExistsResult +Sema::CheckMicrosoftIfExistsSymbol(Scope *S, + CXXScopeSpec &SS, + const DeclarationNameInfo &TargetNameInfo) { + DeclarationName TargetName = TargetNameInfo.getName(); + if (!TargetName) + return IER_DoesNotExist; + + // If the name itself is dependent, then the result is dependent. + if (TargetName.isDependentName()) + return IER_Dependent; + + // Do the redeclaration lookup in the current scope. + LookupResult R(*this, TargetNameInfo, Sema::LookupAnyName, + Sema::NotForRedeclaration); + LookupParsedName(R, S, &SS); + R.suppressDiagnostics(); + + switch (R.getResultKind()) { + case LookupResult::Found: + case LookupResult::FoundOverloaded: + case LookupResult::FoundUnresolvedValue: + case LookupResult::Ambiguous: + return IER_Exists; + + case LookupResult::NotFound: + return IER_DoesNotExist; + + case LookupResult::NotFoundInCurrentInstantiation: + return IER_Dependent; + } + + llvm_unreachable("Invalid LookupResult Kind!"); +} + +Sema::IfExistsResult +Sema::CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc, + bool IsIfExists, CXXScopeSpec &SS, + UnqualifiedId &Name) { + DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name); + + // Check for an unexpanded parameter pack. + auto UPPC = IsIfExists ? UPPC_IfExists : UPPC_IfNotExists; + if (DiagnoseUnexpandedParameterPack(SS, UPPC) || + DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC)) + return IER_Error; + + return CheckMicrosoftIfExistsSymbol(S, SS, TargetNameInfo); +} |