Author: dgregor Date: Wed Feb 15 16:08:38 2012 New Revision: 150620 URL: http://llvm.org/viewvc/llvm-project?rev=150620&view=rev Log: Lambda closure types have a conversion function to a block pointer with the same parameter types and return type as the function call operator. This is the real answer to
http://stackoverflow.com/questions/4148242/is-it-possible-to-convert-a-c0x-lambda-to-a-clang-block :) Modified: cfe/trunk/lib/Sema/SemaLambda.cpp cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/blocks.cpp Modified: cfe/trunk/lib/Sema/SemaLambda.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaLambda.cpp?rev=150620&r1=150619&r2=150620&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaLambda.cpp (original) +++ cfe/trunk/lib/Sema/SemaLambda.cpp Wed Feb 15 16:08:38 2012 @@ -411,6 +411,48 @@ Class->addDecl(Conversion); } +/// \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) { // Leave the expression-evaluation context. @@ -543,6 +585,14 @@ 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 (getLangOptions().Blocks) + addBlockPointerConversion(*this, IntroducerRange, Class, CallOperator); + // Finalize the lambda class. SmallVector<Decl*, 4> Fields(Class->field_begin(), Class->field_end()); ActOnFields(0, Class->getLocation(), Class, Fields, Modified: cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/blocks.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/blocks.cpp?rev=150620&r1=150619&r2=150620&view=diff ============================================================================== --- cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/blocks.cpp (original) +++ cfe/trunk/test/CXX/expr/expr.prim/expr.prim.lambda/blocks.cpp Wed Feb 15 16:08:38 2012 @@ -6,3 +6,10 @@ (void)[=] { var = 17; }; // expected-error{{__block variable 'var' cannot be captured in a lambda}} } + +void conversion_to_block(int captured) { + int (^b1)(int) = [=](int x) { return x + captured; }; + + const auto lambda = [=](int x) { return x + captured; }; + int (^b2)(int) = lambda; +} _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
