Author: adrian Date: Thu Jan 4 17:13:52 2018 New Revision: 321845 URL: http://llvm.org/viewvc/llvm-project?rev=321845&view=rev Log: Debug Info: Support DW_AT_calling_convention on composite types. This implements the DWARF 5 feature described at http://www.dwarfstd.org/ShowIssue.php?issue=141215.1
This allows a consumer to understand whether a composite data type is trivially copyable and thus should be passed by value instead of by reference. The canonical example is being able to distinguish the following two types: // S is not trivially copyable because of the explicit destructor. struct S { ~S() {} }; // T is a POD type. struct T { ~T() = default; }; <rdar://problem/36034993> Differential Revision: https://reviews.llvm.org/D41039 Added: cfe/trunk/test/CodeGenCXX/debug-info-composite-cc.cpp Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.cpp Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.cpp?rev=321845&r1=321844&r2=321845&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/CGDebugInfo.cpp (original) +++ cfe/trunk/lib/CodeGen/CGDebugInfo.cpp Thu Jan 4 17:13:52 2018 @@ -2803,9 +2803,18 @@ llvm::DICompositeType *CGDebugInfo::Crea SmallString<256> FullName = getUniqueTagTypeName(Ty, CGM, TheCU); + // Explicitly record the calling convention for C++ records. + auto Flags = llvm::DINode::FlagZero; + if (auto CXXRD = dyn_cast<CXXRecordDecl>(RD)) { + if (CGM.getCXXABI().getRecordArgABI(CXXRD) == CGCXXABI::RAA_Indirect) + Flags |= llvm::DINode::FlagTypePassByReference; + else + Flags |= llvm::DINode::FlagTypePassByValue; + } + llvm::DICompositeType *RealDecl = DBuilder.createReplaceableCompositeType( getTagForRecord(RD), RDName, RDContext, DefUnit, Line, 0, Size, Align, - llvm::DINode::FlagZero, FullName); + Flags, FullName); // Elements of composite types usually have back to the type, creating // uniquing cycles. Distinct nodes are more efficient. Added: cfe/trunk/test/CodeGenCXX/debug-info-composite-cc.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-composite-cc.cpp?rev=321845&view=auto ============================================================================== --- cfe/trunk/test/CodeGenCXX/debug-info-composite-cc.cpp (added) +++ cfe/trunk/test/CodeGenCXX/debug-info-composite-cc.cpp Thu Jan 4 17:13:52 2018 @@ -0,0 +1,48 @@ +// RUN: %clang_cc1 -emit-llvm -debug-info-kind=standalone -triple %itanium_abi_triple %s -o - | FileCheck %s + +// Not trivially copyable because of the explicit destructor. +// CHECK-DAG: !DICompositeType({{.*}}, name: "RefDtor",{{.*}}flags: DIFlagTypePassByReference +struct RefDtor { + int i; + ~RefDtor() {} +} refDtor; + +// Not trivially copyable because of the explicit copy constructor. +// CHECK-DAG: !DICompositeType({{.*}}, name: "RefCopy",{{.*}}flags: DIFlagTypePassByReference +struct RefCopy { + int i; + RefCopy() = default; + RefCopy(RefCopy &Copy) {} +} refCopy; + +// Not trivially copyable because of the explicit move constructor. +// CHECK-DAG: !DICompositeType({{.*}}, name: "RefMove",{{.*}}flags: DIFlagTypePassByReference +struct RefMove { + int i; + RefMove() = default; + RefMove(RefMove &&Move) {} +} refMove; + +// POD-like type even though it defines a destructor. +// CHECK-DAG: !DICompositeType({{.*}}, name: "Podlike", {{.*}}flags: DIFlagTypePassByValue +struct Podlike { + int i; + Podlike() = default; + Podlike(Podlike &&Move) = default; + ~Podlike() = default; +} podlike; + + +// This is a POD type. +// CHECK-DAG: !DICompositeType({{.*}}, name: "Pod",{{.*}}flags: DIFlagTypePassByValue +struct Pod { + int i; +} pod; + +// This is definitely not a POD type. +// CHECK-DAG: !DICompositeType({{.*}}, name: "Complex",{{.*}}flags: DIFlagTypePassByReference +struct Complex { + Complex() {} + Complex(Complex &Copy) : i(Copy.i) {}; + int i; +} complex; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits