Author: faisalv Date: Mon Oct 7 23:15:04 2013 New Revision: 192166 URL: http://llvm.org/viewvc/llvm-project?rev=192166&view=rev Log: Fix linkage calculation of auto member functions returning lambdas
As described by Richard in https://groups.google.com/a/isocpp.org/d/msg/std-discussion/S1kmj0wF5-g/fb6agEYoL2IJ we should allow: template<typename S> struct A { template<typename T> static auto default_lambda() { return [](const T&) { return 42; }; } template<class U = decltype(default_lambda<S>())> U func(U u = default_lambda<S>()) { return u; } }; int run2 = A<double>{}.func()(3.14); int run3 = A<char>{}.func()('a'); This patch allows the code using the same trickery that was used to allow the code in non-member functions at namespace scope. Please see http://llvm-reviews.chandlerc.com/D1844 for richard's approval. Added: cfe/trunk/test/CodeGenCXX/lambda-expressions-inside-auto-functions.cpp Modified: cfe/trunk/lib/AST/Decl.cpp Modified: cfe/trunk/lib/AST/Decl.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Decl.cpp?rev=192166&r1=192165&r2=192166&view=diff ============================================================================== --- cfe/trunk/lib/AST/Decl.cpp (original) +++ cfe/trunk/lib/AST/Decl.cpp Mon Oct 7 23:15:04 2013 @@ -702,8 +702,8 @@ static LinkageInfo getLVForNamespaceScop // require looking at the linkage of this function, and we don't need this // for correctness because the type is not part of the function's // signature. - // FIXME: This is a hack. We should be able to solve this circularity some - // other way. + // FIXME: This is a hack. We should be able to solve this circularity and + // the one in getLVForClassMember for Functions some other way. QualType TypeAsWritten = Function->getType(); if (TypeSourceInfo *TSI = Function->getTypeSourceInfo()) TypeAsWritten = TSI->getType(); @@ -830,9 +830,20 @@ static LinkageInfo getLVForClassMember(c if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) { // If the type of the function uses a type with unique-external // linkage, it's not legally usable from outside this translation unit. - if (MD->getType()->getLinkage() == UniqueExternalLinkage) - return LinkageInfo::uniqueExternal(); - + // But only look at the type-as-written. If this function has an auto-deduced + // return type, we can't compute the linkage of that type because it could + // require looking at the linkage of this function, and we don't need this + // for correctness because the type is not part of the function's + // signature. + // FIXME: This is a hack. We should be able to solve this circularity and the + // one in getLVForNamespaceScopeDecl for Functions some other way. + { + QualType TypeAsWritten = MD->getType(); + if (TypeSourceInfo *TSI = MD->getTypeSourceInfo()) + TypeAsWritten = TSI->getType(); + if (TypeAsWritten->getLinkage() == UniqueExternalLinkage) + return LinkageInfo::uniqueExternal(); + } // If this is a method template specialization, use the linkage for // the template parameters and arguments. if (FunctionTemplateSpecializationInfo *spec Added: cfe/trunk/test/CodeGenCXX/lambda-expressions-inside-auto-functions.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/lambda-expressions-inside-auto-functions.cpp?rev=192166&view=auto ============================================================================== --- cfe/trunk/test/CodeGenCXX/lambda-expressions-inside-auto-functions.cpp (added) +++ cfe/trunk/test/CodeGenCXX/lambda-expressions-inside-auto-functions.cpp Mon Oct 7 23:15:04 2013 @@ -0,0 +1,77 @@ +// RUN: %clang_cc1 -triple x86_64-apple-darwin10.0.0 -fblocks -emit-llvm -o - %s -fexceptions -std=c++1y | FileCheck %s + +// CHECK-LABEL: define void @_ZN19non_inline_function3fooEv +// CHECK-LABEL: define internal void @"_ZZN19non_inline_function3fooEvENK3$_0clEi"(%class.anon +// CHECK-LABEL: define internal signext i8 @"_ZZZN19non_inline_function3fooEvENK3$_0clEiENKUlcE_clEc"(%class.anon +// CHECK-LABEL: define linkonce_odr void @_ZN19non_inline_function4foo2IiEEDav() +namespace non_inline_function { +auto foo() { + auto L = [](int a) { + return [](char b) { + return b; + }; + }; + L(3)('a'); + return L; +} + +template<typename T> +auto foo2() { + return [](const T&) { return 42; }; +} + +auto use = foo2<int>(); + +} +//CHECK-LABEL: define linkonce_odr void @_ZN22inline_member_function1X3fooEv(%"struct.inline_member_function::X"* %this) +//CHECK-LABEL: define linkonce_odr void @_ZZN22inline_member_function1X3fooEvENKUliE_clEi(%class.anon +//CHECK-LABEL: define linkonce_odr signext i8 @_ZZZN22inline_member_function1X3fooEvENKUliE_clEiENKUlcE_clEc(%class.anon + +namespace inline_member_function { +struct X { +auto foo() { + auto L = [](int a) { + return [](char b) { + return b; + }; + }; + return L; +} +}; + +auto run1 = X{}.foo()(3)('a'); + +template<typename S> +struct A { + template<typename T> static auto default_lambda() { + return [](const T&) { return 42; }; + } + + template<class U = decltype(default_lambda<S>())> + U func(U u = default_lambda<S>()) { return u; } + + template<class T> auto foo() { return [](const T&) { return 42; }; } +}; +//CHECK-LABEL: define linkonce_odr i32 @_ZZN22inline_member_function1AIdE14default_lambdaIdEEDavENKUlRKdE_clES5_(%class.anon +int run2 = A<double>{}.func()(3.14); + +//CHECK-LABEL: define linkonce_odr i32 @_ZZN22inline_member_function1AIcE14default_lambdaIcEEDavENKUlRKcE_clES5_(%class.anon +int run3 = A<char>{}.func()('a'); +} // end inline_member_function + + +// CHECK-LABEL: define linkonce_odr void @_ZN15inline_function3fooEv() +// CHECK: define linkonce_odr void @_ZZN15inline_function3fooEvENKUliE_clEi(%class.anon +// CHECK: define linkonce_odr signext i8 @_ZZZN15inline_function3fooEvENKUliE_clEiENKUlcE_clEc(%class.anon +namespace inline_function { +inline auto foo() { + auto L = [](int a) { + return [](char b) { + return b; + }; + }; + return L; +} +auto use = foo()(3)('a'); +} + _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
