| //===--- SemaLambda.cpp - Semantic Analysis for C++11 Lambdas -------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements semantic analysis for C++ lambda expressions. |
| // |
| //===----------------------------------------------------------------------===// |
| #include "clang/Sema/DeclSpec.h" |
| #include "clang/AST/ExprCXX.h" |
| #include "clang/Lex/Preprocessor.h" |
| #include "clang/Sema/Initialization.h" |
| #include "clang/Sema/Lookup.h" |
| #include "clang/Sema/Scope.h" |
| #include "clang/Sema/ScopeInfo.h" |
| #include "clang/Sema/SemaInternal.h" |
| using namespace clang; |
| using namespace sema; |
| |
| CXXRecordDecl *Sema::createLambdaClosureType(SourceRange IntroducerRange, |
| TypeSourceInfo *Info, |
| bool KnownDependent) { |
| DeclContext *DC = CurContext; |
| while (!(DC->isFunctionOrMethod() || DC->isRecord() || DC->isFileContext())) |
| DC = DC->getParent(); |
| |
| // Start constructing the lambda class. |
| CXXRecordDecl *Class = CXXRecordDecl::CreateLambda(Context, DC, Info, |
| IntroducerRange.getBegin(), |
| KnownDependent); |
| DC->addDecl(Class); |
| |
| return Class; |
| } |
| |
| /// \brief Determine whether the given context is or is enclosed in an inline |
| /// function. |
| static bool isInInlineFunction(const DeclContext *DC) { |
| while (!DC->isFileContext()) { |
| if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) |
| if (FD->isInlined()) |
| return true; |
| |
| DC = DC->getLexicalParent(); |
| } |
| |
| return false; |
| } |
| |
| CXXMethodDecl *Sema::startLambdaDefinition(CXXRecordDecl *Class, |
| SourceRange IntroducerRange, |
| TypeSourceInfo *MethodType, |
| SourceLocation EndLoc, |
| ArrayRef<ParmVarDecl *> Params) { |
| // C++11 [expr.prim.lambda]p5: |
| // The closure type for a lambda-expression has a public inline function |
| // call operator (13.5.4) whose parameters and return type are described by |
| // the lambda-expression's parameter-declaration-clause and |
| // trailing-return-type respectively. |
| DeclarationName MethodName |
| = Context.DeclarationNames.getCXXOperatorName(OO_Call); |
| DeclarationNameLoc MethodNameLoc; |
| MethodNameLoc.CXXOperatorName.BeginOpNameLoc |
| = IntroducerRange.getBegin().getRawEncoding(); |
| MethodNameLoc.CXXOperatorName.EndOpNameLoc |
| = IntroducerRange.getEnd().getRawEncoding(); |
| CXXMethodDecl *Method |
| = CXXMethodDecl::Create(Context, Class, EndLoc, |
| DeclarationNameInfo(MethodName, |
| IntroducerRange.getBegin(), |
| MethodNameLoc), |
| MethodType->getType(), MethodType, |
| /*isStatic=*/false, |
| SC_None, |
| /*isInline=*/true, |
| /*isConstExpr=*/false, |
| EndLoc); |
| Method->setAccess(AS_public); |
| |
| // Temporarily set the lexical declaration context to the current |
| // context, so that the Scope stack matches the lexical nesting. |
| Method->setLexicalDeclContext(CurContext); |
| |
| // Add parameters. |
| if (!Params.empty()) { |
| Method->setParams(Params); |
| CheckParmsForFunctionDef(const_cast<ParmVarDecl **>(Params.begin()), |
| const_cast<ParmVarDecl **>(Params.end()), |
| /*CheckParameterNames=*/false); |
| |
| for (CXXMethodDecl::param_iterator P = Method->param_begin(), |
| PEnd = Method->param_end(); |
| P != PEnd; ++P) |
| (*P)->setOwningFunction(Method); |
| } |
| |
| // Allocate a mangling number for this lambda expression, if the ABI |
| // requires one. |
| Decl *ContextDecl = ExprEvalContexts.back().LambdaContextDecl; |
| |
| enum ContextKind { |
| Normal, |
| DefaultArgument, |
| DataMember, |
| StaticDataMember |
| } Kind = Normal; |
| |
| // Default arguments of member function parameters that appear in a class |
| // definition, as well as the initializers of data members, receive special |
| // treatment. Identify them. |
| if (ContextDecl) { |
| if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(ContextDecl)) { |
| if (const DeclContext *LexicalDC |
| = Param->getDeclContext()->getLexicalParent()) |
| if (LexicalDC->isRecord()) |
| Kind = DefaultArgument; |
| } else if (VarDecl *Var = dyn_cast<VarDecl>(ContextDecl)) { |
| if (Var->getDeclContext()->isRecord()) |
| Kind = StaticDataMember; |
| } else if (isa<FieldDecl>(ContextDecl)) { |
| Kind = DataMember; |
| } |
| } |
| |
| // Itanium ABI [5.1.7]: |
| // In the following contexts [...] the one-definition rule requires closure |
| // types in different translation units to "correspond": |
| bool IsInNonspecializedTemplate = |
| !ActiveTemplateInstantiations.empty() || CurContext->isDependentContext(); |
| unsigned ManglingNumber; |
| switch (Kind) { |
| case Normal: |
| // -- the bodies of non-exported nonspecialized template functions |
| // -- the bodies of inline functions |
| if ((IsInNonspecializedTemplate && |
| !(ContextDecl && isa<ParmVarDecl>(ContextDecl))) || |
| isInInlineFunction(CurContext)) |
| ManglingNumber = Context.getLambdaManglingNumber(Method); |
| else |
| ManglingNumber = 0; |
| |
| // There is no special context for this lambda. |
| ContextDecl = 0; |
| break; |
| |
| case StaticDataMember: |
| // -- the initializers of nonspecialized static members of template classes |
| if (!IsInNonspecializedTemplate) { |
| ManglingNumber = 0; |
| ContextDecl = 0; |
| break; |
| } |
| // Fall through to assign a mangling number. |
| |
| case DataMember: |
| // -- the in-class initializers of class members |
| case DefaultArgument: |
| // -- default arguments appearing in class definitions |
| ManglingNumber = ExprEvalContexts.back().getLambdaMangleContext() |
| .getManglingNumber(Method); |
| break; |
| } |
| |
| Class->setLambdaMangling(ManglingNumber, ContextDecl); |
| |
| return Method; |
| } |
| |
| LambdaScopeInfo *Sema::enterLambdaScope(CXXMethodDecl *CallOperator, |
| SourceRange IntroducerRange, |
| LambdaCaptureDefault CaptureDefault, |
| bool ExplicitParams, |
| bool ExplicitResultType, |
| bool Mutable) { |
| PushLambdaScope(CallOperator->getParent(), CallOperator); |
| LambdaScopeInfo *LSI = getCurLambda(); |
| if (CaptureDefault == LCD_ByCopy) |
| LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByval; |
| else if (CaptureDefault == LCD_ByRef) |
| LSI->ImpCaptureStyle = LambdaScopeInfo::ImpCap_LambdaByref; |
| LSI->IntroducerRange = IntroducerRange; |
| LSI->ExplicitParams = ExplicitParams; |
| LSI->Mutable = Mutable; |
| |
| if (ExplicitResultType) { |
| LSI->ReturnType = CallOperator->getResultType(); |
| |
| if (!LSI->ReturnType->isDependentType() && |
| !LSI->ReturnType->isVoidType()) { |
| if (RequireCompleteType(CallOperator->getLocStart(), LSI->ReturnType, |
| diag::err_lambda_incomplete_result)) { |
| // Do nothing. |
| } else if (LSI->ReturnType->isObjCObjectOrInterfaceType()) { |
| Diag(CallOperator->getLocStart(), diag::err_lambda_objc_object_result) |
| << LSI->ReturnType; |
| } |
| } |
| } else { |
| LSI->HasImplicitReturnType = true; |
| } |
| |
| return LSI; |
| } |
| |
| void Sema::finishLambdaExplicitCaptures(LambdaScopeInfo *LSI) { |
| LSI->finishedExplicitCaptures(); |
| } |
| |
| void Sema::addLambdaParameters(CXXMethodDecl *CallOperator, Scope *CurScope) { |
| // Introduce our parameters into the function scope |
| for (unsigned p = 0, NumParams = CallOperator->getNumParams(); |
| p < NumParams; ++p) { |
| ParmVarDecl *Param = CallOperator->getParamDecl(p); |
| |
| // If this has an identifier, add it to the scope stack. |
| if (CurScope && Param->getIdentifier()) { |
| CheckShadow(CurScope, Param); |
| |
| PushOnScopeChains(Param, CurScope); |
| } |
| } |
| } |
| |
| static bool checkReturnValueType(const ASTContext &Ctx, const Expr *E, |
| QualType &DeducedType, |
| QualType &AlternateType) { |
| // Handle ReturnStmts with no expressions. |
| if (!E) { |
| if (AlternateType.isNull()) |
| AlternateType = Ctx.VoidTy; |
| |
| return Ctx.hasSameType(DeducedType, Ctx.VoidTy); |
| } |
| |
| QualType StrictType = E->getType(); |
| QualType LooseType = StrictType; |
| |
| // In C, enum constants have the type of their underlying integer type, |
| // not the enum. When inferring block return types, we should allow |
| // the enum type if an enum constant is used, unless the enum is |
| // anonymous (in which case there can be no variables of its type). |
| if (!Ctx.getLangOpts().CPlusPlus) { |
| const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()); |
| if (DRE) { |
| const Decl *D = DRE->getDecl(); |
| if (const EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(D)) { |
| const EnumDecl *Enum = cast<EnumDecl>(ECD->getDeclContext()); |
| if (Enum->getDeclName() || Enum->getTypedefNameForAnonDecl()) |
| LooseType = Ctx.getTypeDeclType(Enum); |
| } |
| } |
| } |
| |
| // Special case for the first return statement we find. |
| // The return type has already been tentatively set, but we might still |
| // have an alternate type we should prefer. |
| if (AlternateType.isNull()) |
| AlternateType = LooseType; |
| |
| if (Ctx.hasSameType(DeducedType, StrictType)) { |
| // FIXME: The loose type is different when there are constants from two |
| // different enums. We could consider warning here. |
| if (AlternateType != Ctx.DependentTy) |
| if (!Ctx.hasSameType(AlternateType, LooseType)) |
| AlternateType = Ctx.VoidTy; |
| return true; |
| } |
| |
| if (Ctx.hasSameType(DeducedType, LooseType)) { |
| // Use DependentTy to signal that we're using an alternate type and may |
| // need to add casts somewhere. |
| AlternateType = Ctx.DependentTy; |
| return true; |
| } |
| |
| if (Ctx.hasSameType(AlternateType, StrictType) || |
| Ctx.hasSameType(AlternateType, LooseType)) { |
| DeducedType = AlternateType; |
| // Use DependentTy to signal that we're using an alternate type and may |
| // need to add casts somewhere. |
| AlternateType = Ctx.DependentTy; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| void Sema::deduceClosureReturnType(CapturingScopeInfo &CSI) { |
| assert(CSI.HasImplicitReturnType); |
| |
| // First case: no return statements, implicit void return type. |
| ASTContext &Ctx = getASTContext(); |
| if (CSI.Returns.empty()) { |
| // It's possible there were simply no /valid/ return statements. |
| // In this case, the first one we found may have at least given us a type. |
| if (CSI.ReturnType.isNull()) |
| CSI.ReturnType = Ctx.VoidTy; |
| return; |
| } |
| |
| // Second case: at least one return statement has dependent type. |
| // Delay type checking until instantiation. |
| assert(!CSI.ReturnType.isNull() && "We should have a tentative return type."); |
| if (CSI.ReturnType->isDependentType()) |
| return; |
| |
| // Third case: only one return statement. Don't bother doing extra work! |
| SmallVectorImpl<ReturnStmt*>::iterator I = CSI.Returns.begin(), |
| E = CSI.Returns.end(); |
| if (I+1 == E) |
| return; |
| |
| // General case: many return statements. |
| // Check that they all have compatible return types. |
| // For now, that means "identical", with an exception for enum constants. |
| // (In C, enum constants have the type of their underlying integer type, |
| // not the type of the enum. C++ uses the type of the enum.) |
| QualType AlternateType; |
| |
| // We require the return types to strictly match here. |
| for (; I != E; ++I) { |
| const ReturnStmt *RS = *I; |
| const Expr *RetE = RS->getRetValue(); |
| if (!checkReturnValueType(Ctx, RetE, CSI.ReturnType, AlternateType)) { |
| // FIXME: This is a poor diagnostic for ReturnStmts without expressions. |
| Diag(RS->getLocStart(), |
| diag::err_typecheck_missing_return_type_incompatible) |
| << (RetE ? RetE->getType() : Ctx.VoidTy) << CSI.ReturnType |
| << isa<LambdaScopeInfo>(CSI); |
| // Don't bother fixing up the return statements in the block if some of |
| // them are unfixable anyway. |
| AlternateType = Ctx.VoidTy; |
| // Continue iterating so that we keep emitting diagnostics. |
| } |
| } |
| |
| // If our return statements turned out to be compatible, but we needed to |
| // pick a different return type, go through and fix the ones that need it. |
| if (AlternateType == Ctx.DependentTy) { |
| for (SmallVectorImpl<ReturnStmt*>::iterator I = CSI.Returns.begin(), |
| E = CSI.Returns.end(); |
| I != E; ++I) { |
| ReturnStmt *RS = *I; |
| Expr *RetE = RS->getRetValue(); |
| if (RetE->getType() == CSI.ReturnType) |
| continue; |
| |
| // Right now we only support integral fixup casts. |
| assert(CSI.ReturnType->isIntegralOrUnscopedEnumerationType()); |
| assert(RetE->getType()->isIntegralOrUnscopedEnumerationType()); |
| ExprResult Casted = ImpCastExprToType(RetE, CSI.ReturnType, |
| CK_IntegralCast); |
| assert(Casted.isUsable()); |
| RS->setRetValue(Casted.take()); |
| } |
| } |
| } |
| |
| void Sema::ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro, |
| Declarator &ParamInfo, |
| Scope *CurScope) { |
| // Determine if we're within a context where we know that the lambda will |
| // be dependent, because there are template parameters in scope. |
| bool KnownDependent = false; |
| if (Scope *TmplScope = CurScope->getTemplateParamParent()) |
| if (!TmplScope->decl_empty()) |
| KnownDependent = true; |
| |
| // Determine the signature of the call operator. |
| TypeSourceInfo *MethodTyInfo; |
| bool ExplicitParams = true; |
| bool ExplicitResultType = true; |
| bool ContainsUnexpandedParameterPack = false; |
| SourceLocation EndLoc; |
| SmallVector<ParmVarDecl *, 8> Params; |
| if (ParamInfo.getNumTypeObjects() == 0) { |
| // C++11 [expr.prim.lambda]p4: |
| // If a lambda-expression does not include a lambda-declarator, it is as |
| // if the lambda-declarator were (). |
| FunctionProtoType::ExtProtoInfo EPI; |
| EPI.HasTrailingReturn = true; |
| EPI.TypeQuals |= DeclSpec::TQ_const; |
| QualType MethodTy = Context.getFunctionType(Context.DependentTy, |
| /*Args=*/0, /*NumArgs=*/0, EPI); |
| MethodTyInfo = Context.getTrivialTypeSourceInfo(MethodTy); |
| ExplicitParams = false; |
| ExplicitResultType = false; |
| EndLoc = Intro.Range.getEnd(); |
| } else { |
| assert(ParamInfo.isFunctionDeclarator() && |
| "lambda-declarator is a function"); |
| DeclaratorChunk::FunctionTypeInfo &FTI = ParamInfo.getFunctionTypeInfo(); |
| |
| // C++11 [expr.prim.lambda]p5: |
| // This function call operator is declared const (9.3.1) if and only if |
| // the lambda-expression's parameter-declaration-clause is not followed |
| // by mutable. It is neither virtual nor declared volatile. [...] |
| if (!FTI.hasMutableQualifier()) |
| FTI.TypeQuals |= DeclSpec::TQ_const; |
| |
| MethodTyInfo = GetTypeForDeclarator(ParamInfo, CurScope); |
| assert(MethodTyInfo && "no type from lambda-declarator"); |
| EndLoc = ParamInfo.getSourceRange().getEnd(); |
| |
| ExplicitResultType |
| = MethodTyInfo->getType()->getAs<FunctionType>()->getResultType() |
| != Context.DependentTy; |
| |
| if (FTI.NumArgs == 1 && !FTI.isVariadic && FTI.ArgInfo[0].Ident == 0 && |
| cast<ParmVarDecl>(FTI.ArgInfo[0].Param)->getType()->isVoidType()) { |
| // Empty arg list, don't push any params. |
| checkVoidParamDecl(cast<ParmVarDecl>(FTI.ArgInfo[0].Param)); |
| } else { |
| Params.reserve(FTI.NumArgs); |
| for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) |
| Params.push_back(cast<ParmVarDecl>(FTI.ArgInfo[i].Param)); |
| } |
| |
| // Check for unexpanded parameter packs in the method type. |
| if (MethodTyInfo->getType()->containsUnexpandedParameterPack()) |
| ContainsUnexpandedParameterPack = true; |
| } |
| |
| CXXRecordDecl *Class = createLambdaClosureType(Intro.Range, MethodTyInfo, |
| KnownDependent); |
| |
| CXXMethodDecl *Method = startLambdaDefinition(Class, Intro.Range, |
| MethodTyInfo, EndLoc, Params); |
| |
| if (ExplicitParams) |
| CheckCXXDefaultArguments(Method); |
| |
| // Attributes on the lambda apply to the method. |
| ProcessDeclAttributes(CurScope, Method, ParamInfo); |
| |
| // Introduce the function call operator as the current declaration context. |
| PushDeclContext(CurScope, Method); |
| |
| // Introduce the lambda scope. |
| LambdaScopeInfo *LSI |
| = enterLambdaScope(Method, Intro.Range, Intro.Default, ExplicitParams, |
| ExplicitResultType, |
| !Method->isConst()); |
| |
| // Handle explicit captures. |
| SourceLocation PrevCaptureLoc |
| = Intro.Default == LCD_None? Intro.Range.getBegin() : Intro.DefaultLoc; |
| for (SmallVector<LambdaCapture, 4>::const_iterator |
| C = Intro.Captures.begin(), |
| E = Intro.Captures.end(); |
| C != E; |
| PrevCaptureLoc = C->Loc, ++C) { |
| if (C->Kind == LCK_This) { |
| // C++11 [expr.prim.lambda]p8: |
| // An identifier or this shall not appear more than once in a |
| // lambda-capture. |
| if (LSI->isCXXThisCaptured()) { |
| Diag(C->Loc, diag::err_capture_more_than_once) |
| << "'this'" |
| << SourceRange(LSI->getCXXThisCapture().getLocation()) |
| << FixItHint::CreateRemoval( |
| SourceRange(PP.getLocForEndOfToken(PrevCaptureLoc), C->Loc)); |
| continue; |
| } |
| |
| // C++11 [expr.prim.lambda]p8: |
| // If a lambda-capture includes a capture-default that is =, the |
| // lambda-capture shall not contain this [...]. |
| if (Intro.Default == LCD_ByCopy) { |
| Diag(C->Loc, diag::err_this_capture_with_copy_default) |
| << FixItHint::CreateRemoval( |
| SourceRange(PP.getLocForEndOfToken(PrevCaptureLoc), C->Loc)); |
| continue; |
| } |
| |
| // C++11 [expr.prim.lambda]p12: |
| // If this is captured by a local lambda expression, its nearest |
| // enclosing function shall be a non-static member function. |
| QualType ThisCaptureType = getCurrentThisType(); |
| if (ThisCaptureType.isNull()) { |
| Diag(C->Loc, diag::err_this_capture) << true; |
| continue; |
| } |
| |
| CheckCXXThisCapture(C->Loc, /*Explicit=*/true); |
| continue; |
| } |
| |
| assert(C->Id && "missing identifier for capture"); |
| |
| // C++11 [expr.prim.lambda]p8: |
| // If a lambda-capture includes a capture-default that is &, the |
| // identifiers in the lambda-capture shall not be preceded by &. |
| // If a lambda-capture includes a capture-default that is =, [...] |
| // each identifier it contains shall be preceded by &. |
| if (C->Kind == LCK_ByRef && Intro.Default == LCD_ByRef) { |
| Diag(C->Loc, diag::err_reference_capture_with_reference_default) |
| << FixItHint::CreateRemoval( |
| SourceRange(PP.getLocForEndOfToken(PrevCaptureLoc), C->Loc)); |
| continue; |
| } else if (C->Kind == LCK_ByCopy && Intro.Default == LCD_ByCopy) { |
| Diag(C->Loc, diag::err_copy_capture_with_copy_default) |
| << FixItHint::CreateRemoval( |
| SourceRange(PP.getLocForEndOfToken(PrevCaptureLoc), C->Loc)); |
| continue; |
| } |
| |
| DeclarationNameInfo Name(C->Id, C->Loc); |
| LookupResult R(*this, Name, LookupOrdinaryName); |
| LookupName(R, CurScope); |
| if (R.isAmbiguous()) |
| continue; |
| if (R.empty()) { |
| // FIXME: Disable corrections that would add qualification? |
| CXXScopeSpec ScopeSpec; |
| DeclFilterCCC<VarDecl> Validator; |
| if (DiagnoseEmptyLookup(CurScope, ScopeSpec, R, Validator)) |
| continue; |
| } |
| |
| // C++11 [expr.prim.lambda]p10: |
| // The identifiers in a capture-list are looked up using the usual rules |
| // for unqualified name lookup (3.4.1); each such lookup shall find a |
| // variable with automatic storage duration declared in the reaching |
| // scope of the local lambda expression. |
| // |
| // Note that the 'reaching scope' check happens in tryCaptureVariable(). |
| VarDecl *Var = R.getAsSingle<VarDecl>(); |
| if (!Var) { |
| Diag(C->Loc, diag::err_capture_does_not_name_variable) << C->Id; |
| continue; |
| } |
| |
| // Ignore invalid decls; they'll just confuse the code later. |
| if (Var->isInvalidDecl()) |
| continue; |
| |
| if (!Var->hasLocalStorage()) { |
| Diag(C->Loc, diag::err_capture_non_automatic_variable) << C->Id; |
| Diag(Var->getLocation(), diag::note_previous_decl) << C->Id; |
| continue; |
| } |
| |
| // C++11 [expr.prim.lambda]p8: |
| // An identifier or this shall not appear more than once in a |
| // lambda-capture. |
| if (LSI->isCaptured(Var)) { |
| Diag(C->Loc, diag::err_capture_more_than_once) |
| << C->Id |
| << SourceRange(LSI->getCapture(Var).getLocation()) |
| << FixItHint::CreateRemoval( |
| SourceRange(PP.getLocForEndOfToken(PrevCaptureLoc), C->Loc)); |
| continue; |
| } |
| |
| // C++11 [expr.prim.lambda]p23: |
| // A capture followed by an ellipsis is a pack expansion (14.5.3). |
| SourceLocation EllipsisLoc; |
| if (C->EllipsisLoc.isValid()) { |
| if (Var->isParameterPack()) { |
| EllipsisLoc = C->EllipsisLoc; |
| } else { |
| Diag(C->EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) |
| << SourceRange(C->Loc); |
| |
| // Just ignore the ellipsis. |
| } |
| } else if (Var->isParameterPack()) { |
| ContainsUnexpandedParameterPack = true; |
| } |
| |
| TryCaptureKind Kind = C->Kind == LCK_ByRef ? TryCapture_ExplicitByRef : |
| TryCapture_ExplicitByVal; |
| tryCaptureVariable(Var, C->Loc, Kind, EllipsisLoc); |
| } |
| finishLambdaExplicitCaptures(LSI); |
| |
| LSI->ContainsUnexpandedParameterPack = ContainsUnexpandedParameterPack; |
| |
| // Add lambda parameters into scope. |
| addLambdaParameters(Method, CurScope); |
| |
| // Enter a new evaluation context to insulate the lambda from any |
| // cleanups from the enclosing full-expression. |
| PushExpressionEvaluationContext(PotentiallyEvaluated); |
| } |
| |
| void Sema::ActOnLambdaError(SourceLocation StartLoc, Scope *CurScope, |
| bool IsInstantiation) { |
| // Leave the expression-evaluation context. |
| DiscardCleanupsInEvaluationContext(); |
| PopExpressionEvaluationContext(); |
| |
| // Leave the context of the lambda. |
| if (!IsInstantiation) |
| PopDeclContext(); |
| |
| // Finalize the lambda. |
| LambdaScopeInfo *LSI = getCurLambda(); |
| CXXRecordDecl *Class = LSI->Lambda; |
| Class->setInvalidDecl(); |
| SmallVector<Decl*, 4> Fields; |
| for (RecordDecl::field_iterator i = Class->field_begin(), |
| e = Class->field_end(); i != e; ++i) |
| Fields.push_back(*i); |
| ActOnFields(0, Class->getLocation(), Class, Fields, |
| SourceLocation(), SourceLocation(), 0); |
| CheckCompletedCXXClass(Class); |
| |
| PopFunctionScopeInfo(); |
| } |
| |
| /// \brief Add a lambda's conversion to function pointer, as described in |
| /// C++11 [expr.prim.lambda]p6. |
| static void addFunctionPointerConversion(Sema &S, |
| SourceRange IntroducerRange, |
| CXXRecordDecl *Class, |
| CXXMethodDecl *CallOperator) { |
| // Add the conversion to function pointer. |
| const FunctionProtoType *Proto |
| = CallOperator->getType()->getAs<FunctionProtoType>(); |
| QualType FunctionPtrTy; |
| QualType FunctionTy; |
| { |
| FunctionProtoType::ExtProtoInfo ExtInfo = Proto->getExtProtoInfo(); |
| ExtInfo.TypeQuals = 0; |
| FunctionTy = S.Context.getFunctionType(Proto->getResultType(), |
| Proto->arg_type_begin(), |
| Proto->getNumArgs(), |
| ExtInfo); |
| FunctionPtrTy = S.Context.getPointerType(FunctionTy); |
| } |
| |
| FunctionProtoType::ExtProtoInfo ExtInfo; |
| ExtInfo.TypeQuals = Qualifiers::Const; |
| QualType ConvTy = S.Context.getFunctionType(FunctionPtrTy, 0, 0, ExtInfo); |
| |
| SourceLocation Loc = IntroducerRange.getBegin(); |
| DeclarationName Name |
| = S.Context.DeclarationNames.getCXXConversionFunctionName( |
| S.Context.getCanonicalType(FunctionPtrTy)); |
| DeclarationNameLoc NameLoc; |
| NameLoc.NamedType.TInfo = S.Context.getTrivialTypeSourceInfo(FunctionPtrTy, |
| Loc); |
| CXXConversionDecl *Conversion |
| = CXXConversionDecl::Create(S.Context, Class, Loc, |
| DeclarationNameInfo(Name, Loc, NameLoc), |
| ConvTy, |
| S.Context.getTrivialTypeSourceInfo(ConvTy, |
| Loc), |
| /*isInline=*/false, /*isExplicit=*/false, |
| /*isConstexpr=*/false, |
| CallOperator->getBody()->getLocEnd()); |
| Conversion->setAccess(AS_public); |
| Conversion->setImplicit(true); |
| Class->addDecl(Conversion); |
| |
| // Add a non-static member function "__invoke" that will be the result of |
| // the conversion. |
| Name = &S.Context.Idents.get("__invoke"); |
| CXXMethodDecl *Invoke |
| = CXXMethodDecl::Create(S.Context, Class, Loc, |
| DeclarationNameInfo(Name, Loc), FunctionTy, |
| CallOperator->getTypeSourceInfo(), |
| /*IsStatic=*/true, SC_Static, /*IsInline=*/true, |
| /*IsConstexpr=*/false, |
| CallOperator->getBody()->getLocEnd()); |
| SmallVector<ParmVarDecl *, 4> InvokeParams; |
| for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) { |
| ParmVarDecl *From = CallOperator->getParamDecl(I); |
| InvokeParams.push_back(ParmVarDecl::Create(S.Context, Invoke, |
| From->getLocStart(), |
| From->getLocation(), |
| From->getIdentifier(), |
| From->getType(), |
| From->getTypeSourceInfo(), |
| From->getStorageClass(), |
| From->getStorageClassAsWritten(), |
| /*DefaultArg=*/0)); |
| } |
| Invoke->setParams(InvokeParams); |
| Invoke->setAccess(AS_private); |
| Invoke->setImplicit(true); |
| Class->addDecl(Invoke); |
| } |
| |
| /// \brief Add a lambda's conversion to block pointer. |
| static void addBlockPointerConversion(Sema &S, |
| SourceRange IntroducerRange, |
| CXXRecordDecl *Class, |
| CXXMethodDecl *CallOperator) { |
| const FunctionProtoType *Proto |
| = CallOperator->getType()->getAs<FunctionProtoType>(); |
| QualType BlockPtrTy; |
| { |
| FunctionProtoType::ExtProtoInfo ExtInfo = Proto->getExtProtoInfo(); |
| ExtInfo.TypeQuals = 0; |
| QualType FunctionTy |
| = S.Context.getFunctionType(Proto->getResultType(), |
| Proto->arg_type_begin(), |
| Proto->getNumArgs(), |
| ExtInfo); |
| BlockPtrTy = S.Context.getBlockPointerType(FunctionTy); |
| } |
| |
| FunctionProtoType::ExtProtoInfo ExtInfo; |
| ExtInfo.TypeQuals = Qualifiers::Const; |
| QualType ConvTy = S.Context.getFunctionType(BlockPtrTy, 0, 0, ExtInfo); |
| |
| SourceLocation Loc = IntroducerRange.getBegin(); |
| DeclarationName Name |
| = S.Context.DeclarationNames.getCXXConversionFunctionName( |
| S.Context.getCanonicalType(BlockPtrTy)); |
| DeclarationNameLoc NameLoc; |
| NameLoc.NamedType.TInfo = S.Context.getTrivialTypeSourceInfo(BlockPtrTy, Loc); |
| CXXConversionDecl *Conversion |
| = CXXConversionDecl::Create(S.Context, Class, Loc, |
| DeclarationNameInfo(Name, Loc, NameLoc), |
| ConvTy, |
| S.Context.getTrivialTypeSourceInfo(ConvTy, Loc), |
| /*isInline=*/false, /*isExplicit=*/false, |
| /*isConstexpr=*/false, |
| CallOperator->getBody()->getLocEnd()); |
| Conversion->setAccess(AS_public); |
| Conversion->setImplicit(true); |
| Class->addDecl(Conversion); |
| } |
| |
| ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body, |
| Scope *CurScope, |
| bool IsInstantiation) { |
| // Collect information from the lambda scope. |
| SmallVector<LambdaExpr::Capture, 4> Captures; |
| SmallVector<Expr *, 4> CaptureInits; |
| LambdaCaptureDefault CaptureDefault; |
| CXXRecordDecl *Class; |
| CXXMethodDecl *CallOperator; |
| SourceRange IntroducerRange; |
| bool ExplicitParams; |
| bool ExplicitResultType; |
| bool LambdaExprNeedsCleanups; |
| bool ContainsUnexpandedParameterPack; |
| SmallVector<VarDecl *, 4> ArrayIndexVars; |
| SmallVector<unsigned, 4> ArrayIndexStarts; |
| { |
| LambdaScopeInfo *LSI = getCurLambda(); |
| CallOperator = LSI->CallOperator; |
| Class = LSI->Lambda; |
| IntroducerRange = LSI->IntroducerRange; |
| ExplicitParams = LSI->ExplicitParams; |
| ExplicitResultType = !LSI->HasImplicitReturnType; |
| LambdaExprNeedsCleanups = LSI->ExprNeedsCleanups; |
| ContainsUnexpandedParameterPack = LSI->ContainsUnexpandedParameterPack; |
| ArrayIndexVars.swap(LSI->ArrayIndexVars); |
| ArrayIndexStarts.swap(LSI->ArrayIndexStarts); |
| |
| // Translate captures. |
| for (unsigned I = 0, N = LSI->Captures.size(); I != N; ++I) { |
| LambdaScopeInfo::Capture From = LSI->Captures[I]; |
| assert(!From.isBlockCapture() && "Cannot capture __block variables"); |
| bool IsImplicit = I >= LSI->NumExplicitCaptures; |
| |
| // Handle 'this' capture. |
| if (From.isThisCapture()) { |
| Captures.push_back(LambdaExpr::Capture(From.getLocation(), |
| IsImplicit, |
| LCK_This)); |
| CaptureInits.push_back(new (Context) CXXThisExpr(From.getLocation(), |
| getCurrentThisType(), |
| /*isImplicit=*/true)); |
| continue; |
| } |
| |
| VarDecl *Var = From.getVariable(); |
| LambdaCaptureKind Kind = From.isCopyCapture()? LCK_ByCopy : LCK_ByRef; |
| Captures.push_back(LambdaExpr::Capture(From.getLocation(), IsImplicit, |
| Kind, Var, From.getEllipsisLoc())); |
| CaptureInits.push_back(From.getCopyExpr()); |
| } |
| |
| switch (LSI->ImpCaptureStyle) { |
| case CapturingScopeInfo::ImpCap_None: |
| CaptureDefault = LCD_None; |
| break; |
| |
| case CapturingScopeInfo::ImpCap_LambdaByval: |
| CaptureDefault = LCD_ByCopy; |
| break; |
| |
| case CapturingScopeInfo::ImpCap_LambdaByref: |
| CaptureDefault = LCD_ByRef; |
| break; |
| |
| case CapturingScopeInfo::ImpCap_Block: |
| llvm_unreachable("block capture in lambda"); |
| break; |
| } |
| |
| // C++11 [expr.prim.lambda]p4: |
| // If a lambda-expression does not include a |
| // trailing-return-type, it is as if the trailing-return-type |
| // denotes the following type: |
| // FIXME: Assumes current resolution to core issue 975. |
| if (LSI->HasImplicitReturnType) { |
| deduceClosureReturnType(*LSI); |
| |
| // - if there are no return statements in the |
| // compound-statement, or all return statements return |
| // either an expression of type void or no expression or |
| // braced-init-list, the type void; |
| if (LSI->ReturnType.isNull()) { |
| LSI->ReturnType = Context.VoidTy; |
| } |
| |
| // Create a function type with the inferred return type. |
| const FunctionProtoType *Proto |
| = CallOperator->getType()->getAs<FunctionProtoType>(); |
| QualType FunctionTy |
| = Context.getFunctionType(LSI->ReturnType, |
| Proto->arg_type_begin(), |
| Proto->getNumArgs(), |
| Proto->getExtProtoInfo()); |
| CallOperator->setType(FunctionTy); |
| } |
| |
| // C++ [expr.prim.lambda]p7: |
| // The lambda-expression's compound-statement yields the |
| // function-body (8.4) of the function call operator [...]. |
| ActOnFinishFunctionBody(CallOperator, Body, IsInstantiation); |
| CallOperator->setLexicalDeclContext(Class); |
| Class->addDecl(CallOperator); |
| PopExpressionEvaluationContext(); |
| |
| // C++11 [expr.prim.lambda]p6: |
| // The closure type for a lambda-expression with no lambda-capture |
| // has a public non-virtual non-explicit const conversion function |
| // to pointer to function having the same parameter and return |
| // types as the closure type's function call operator. |
| if (Captures.empty() && CaptureDefault == LCD_None) |
| addFunctionPointerConversion(*this, IntroducerRange, Class, |
| CallOperator); |
| |
| // Objective-C++: |
| // The closure type for a lambda-expression has a public non-virtual |
| // non-explicit const conversion function to a block pointer having the |
| // same parameter and return types as the closure type's function call |
| // operator. |
| if (getLangOpts().Blocks && getLangOpts().ObjC1) |
| addBlockPointerConversion(*this, IntroducerRange, Class, CallOperator); |
| |
| // Finalize the lambda class. |
| SmallVector<Decl*, 4> Fields; |
| for (RecordDecl::field_iterator i = Class->field_begin(), |
| e = Class->field_end(); i != e; ++i) |
| Fields.push_back(*i); |
| ActOnFields(0, Class->getLocation(), Class, Fields, |
| SourceLocation(), SourceLocation(), 0); |
| CheckCompletedCXXClass(Class); |
| } |
| |
| if (LambdaExprNeedsCleanups) |
| ExprNeedsCleanups = true; |
| |
| LambdaExpr *Lambda = LambdaExpr::Create(Context, Class, IntroducerRange, |
| CaptureDefault, Captures, |
| ExplicitParams, ExplicitResultType, |
| CaptureInits, ArrayIndexVars, |
| ArrayIndexStarts, Body->getLocEnd(), |
| ContainsUnexpandedParameterPack); |
| |
| // C++11 [expr.prim.lambda]p2: |
| // A lambda-expression shall not appear in an unevaluated operand |
| // (Clause 5). |
| if (!CurContext->isDependentContext()) { |
| switch (ExprEvalContexts.back().Context) { |
| case Unevaluated: |
| // We don't actually diagnose this case immediately, because we |
| // could be within a context where we might find out later that |
| // the expression is potentially evaluated (e.g., for typeid). |
| ExprEvalContexts.back().Lambdas.push_back(Lambda); |
| break; |
| |
| case ConstantEvaluated: |
| case PotentiallyEvaluated: |
| case PotentiallyEvaluatedIfUsed: |
| break; |
| } |
| } |
| |
| return MaybeBindToTemporary(Lambda); |
| } |
| |
| ExprResult Sema::BuildBlockForLambdaConversion(SourceLocation CurrentLocation, |
| SourceLocation ConvLocation, |
| CXXConversionDecl *Conv, |
| Expr *Src) { |
| // Make sure that the lambda call operator is marked used. |
| CXXRecordDecl *Lambda = Conv->getParent(); |
| CXXMethodDecl *CallOperator |
| = cast<CXXMethodDecl>( |
| Lambda->lookup( |
| Context.DeclarationNames.getCXXOperatorName(OO_Call)).front()); |
| CallOperator->setReferenced(); |
| CallOperator->setUsed(); |
| |
| ExprResult Init = PerformCopyInitialization( |
| InitializedEntity::InitializeBlock(ConvLocation, |
| Src->getType(), |
| /*NRVO=*/false), |
| CurrentLocation, Src); |
| if (!Init.isInvalid()) |
| Init = ActOnFinishFullExpr(Init.take()); |
| |
| if (Init.isInvalid()) |
| return ExprError(); |
| |
| // Create the new block to be returned. |
| BlockDecl *Block = BlockDecl::Create(Context, CurContext, ConvLocation); |
| |
| // Set the type information. |
| Block->setSignatureAsWritten(CallOperator->getTypeSourceInfo()); |
| Block->setIsVariadic(CallOperator->isVariadic()); |
| Block->setBlockMissingReturnType(false); |
| |
| // Add parameters. |
| SmallVector<ParmVarDecl *, 4> BlockParams; |
| for (unsigned I = 0, N = CallOperator->getNumParams(); I != N; ++I) { |
| ParmVarDecl *From = CallOperator->getParamDecl(I); |
| BlockParams.push_back(ParmVarDecl::Create(Context, Block, |
| From->getLocStart(), |
| From->getLocation(), |
| From->getIdentifier(), |
| From->getType(), |
| From->getTypeSourceInfo(), |
| From->getStorageClass(), |
| From->getStorageClassAsWritten(), |
| /*DefaultArg=*/0)); |
| } |
| Block->setParams(BlockParams); |
| |
| Block->setIsConversionFromLambda(true); |
| |
| // Add capture. The capture uses a fake variable, which doesn't correspond |
| // to any actual memory location. However, the initializer copy-initializes |
| // the lambda object. |
| TypeSourceInfo *CapVarTSI = |
| Context.getTrivialTypeSourceInfo(Src->getType()); |
| VarDecl *CapVar = VarDecl::Create(Context, Block, ConvLocation, |
| ConvLocation, 0, |
| Src->getType(), CapVarTSI, |
| SC_None, SC_None); |
| BlockDecl::Capture Capture(/*Variable=*/CapVar, /*ByRef=*/false, |
| /*Nested=*/false, /*Copy=*/Init.take()); |
| Block->setCaptures(Context, &Capture, &Capture + 1, |
| /*CapturesCXXThis=*/false); |
| |
| // Add a fake function body to the block. IR generation is responsible |
| // for filling in the actual body, which cannot be expressed as an AST. |
| Block->setBody(new (Context) CompoundStmt(ConvLocation)); |
| |
| // Create the block literal expression. |
| Expr *BuildBlock = new (Context) BlockExpr(Block, Conv->getConversionType()); |
| ExprCleanupObjects.push_back(Block); |
| ExprNeedsCleanups = true; |
| |
| return BuildBlock; |
| } |
