Author: Orlando Cazalet-Hyams Date: 2024-04-25T10:34:32+01:00 New Revision: 87ec4ab72cb3ae27ac08d040b2825ee01214fe75
URL: https://github.com/llvm/llvm-project/commit/87ec4ab72cb3ae27ac08d040b2825ee01214fe75 DIFF: https://github.com/llvm/llvm-project/commit/87ec4ab72cb3ae27ac08d040b2825ee01214fe75.diff LOG: [Clang] Fall back to DW_TAG_typedef for instantiation dependent template aliases (#90032) Workaround for issue #89774 until it can be properly fixed. When `-gtemplate-alias` is specified Clang emits a DW_TAG_template_alias for template aliases. This patch avoids an assertion failure by falling back to the `-gno-template-alias` (default) behaviour, emitting a DW_TAG_typedef, if the alias is instantiation dependent. Added: clang/test/CodeGenCXX/dependent-template-alias.cpp Modified: clang/lib/CodeGen/CGDebugInfo.cpp Removed: ################################################################################ diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp index 539ded5cca5e1b..787db350487417 100644 --- a/clang/lib/CodeGen/CGDebugInfo.cpp +++ b/clang/lib/CodeGen/CGDebugInfo.cpp @@ -1372,7 +1372,26 @@ llvm::DIType *CGDebugInfo::CreateType(const TemplateSpecializationType *Ty, SourceLocation Loc = AliasDecl->getLocation(); - if (CGM.getCodeGenOpts().DebugTemplateAlias) { + if (CGM.getCodeGenOpts().DebugTemplateAlias && + // The TemplateSpecializationType doesn't contain any instantiation + // information; dependent template arguments can't be resolved. For now, + // fall back to DW_TAG_typedefs for template aliases that are + // instantiation dependent, e.g.: + // ``` + // template <int> + // using A = int; + // + // template<int I> + // struct S { + // using AA = A<I>; // Instantiation dependent. + // AA aa; + // }; + // + // S<0> s; + // ``` + // S::AA's underlying type A<I> is dependent on I so will be emitted as a + // DW_TAG_typedef. + !Ty->isInstantiationDependentType()) { auto ArgVector = ::GetTemplateArgs(TD, Ty); TemplateArgs Args = {TD->getTemplateParameters(), ArgVector}; diff --git a/clang/test/CodeGenCXX/dependent-template-alias.cpp b/clang/test/CodeGenCXX/dependent-template-alias.cpp new file mode 100644 index 00000000000000..deb243f9fc88d0 --- /dev/null +++ b/clang/test/CodeGenCXX/dependent-template-alias.cpp @@ -0,0 +1,21 @@ +// RUN: %clang_cc1 -triple x86_64-unk-unk -o - -emit-llvm -debug-info-kind=standalone -gtemplate-alias %s -gsimple-template-names=simple \ +// RUN: | FileCheck %s + +//// Check that -gtemplate-alias falls back to DW_TAG_typedef emission +//// for instantiation dependent type aliases. + +template <int> +using A = int; + +template<int I> +struct S { + using AA = A<I>; + AA aa; +}; + +S<0> s; + +// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "aa", scope: ![[#]], file: ![[#]], line: [[#]], baseType: ![[AA:[0-9]+]], size: 32) +// CHECK: [[AA]] = !DIDerivedType(tag: DW_TAG_typedef, name: "AA", file: ![[#]], line: [[#]], baseType: ![[A:[0-9]+]]) +// CHECK: [[A]] = !DIDerivedType(tag: DW_TAG_typedef, name: "A<I>", file: ![[#]], line: [[#]], baseType: ![[int:[0-9]+]]) +// CHECK: [[int]] = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
