Author: Michael Buch Date: 2024-10-02T19:38:51+01:00 New Revision: 52a9ba7ca4fb9427706c28bb3ca15f7a56eecf3f
URL: https://github.com/llvm/llvm-project/commit/52a9ba7ca4fb9427706c28bb3ca15f7a56eecf3f DIFF: https://github.com/llvm/llvm-project/commit/52a9ba7ca4fb9427706c28bb3ca15f7a56eecf3f.diff LOG: [clang][DebugInfo] Revert to printing canonical typenames for template aliases (#110767) This was originally added in https://reviews.llvm.org/D142268 to have LLDB display variable typenames that benefit from suppressing defaulted template arguments. We currently represent template aliases as `DW_AT_typedef`s instead of `DW_TAG_template_alias`. This means for types like: ``` template <class _Tp> using __remove_cv_t = __remove_cv(_Tp); template <class _Tp> using remove_cv_t = __remove_cv_t<_Tp>; template<typename T> class optional { using value_type = T; remove_cv_t<value_type> __val_; } ``` we would generate DWARF like: ``` 0x0000274f: DW_TAG_typedef DW_AT_type (0x0000000000002758 "__remove_cv_t<value_type>") DW_AT_name ("remove_cv_t<value_type>") ``` This is an actual libc++ type layout introduced in https://github.com/llvm/llvm-project/pull/110355, and uncovered a shortcoming of LLDB's data-formatter infrastructure, where we cache formatters on the contents of `DW_AT_name` (which currently wouldn't be a fully resolved typename for template specializations). To unblock the libc++ change, I think we can revert this without much fallout. Then we have two options for follow-up (or do both): 1. reland this but adjust the LLDB formatter cache so it doesn't cache formatters for template specializations 2. implement support for `DW_TAG_template_alias` in LLDB (and make Clang generate them by default). Added: Modified: clang/lib/CodeGen/CGDebugInfo.cpp clang/test/CodeGenCXX/debug-info-alias.cpp Removed: ################################################################################ diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp index 8887c4de7c4c81..609957b75d6e7e 100644 --- a/clang/lib/CodeGen/CGDebugInfo.cpp +++ b/clang/lib/CodeGen/CGDebugInfo.cpp @@ -1472,15 +1472,6 @@ llvm::DIType *CGDebugInfo::CreateType(const TemplateSpecializationType *Ty, return AliasTy; } - // Disable PrintCanonicalTypes here because we want - // the DW_AT_name to benefit from the TypePrinter's ability - // to skip defaulted template arguments. - // - // FIXME: Once -gsimple-template-names is enabled by default - // and we attach template parameters to alias template DIEs - // we don't need to worry about customizing the PrintingPolicy - // here anymore. - PP.PrintCanonicalTypes = false; printTemplateArgumentList(OS, Ty->template_arguments(), PP, TD->getTemplateParameters()); return DBuilder.createTypedef(Src, OS.str(), getOrCreateFile(Loc), diff --git a/clang/test/CodeGenCXX/debug-info-alias.cpp b/clang/test/CodeGenCXX/debug-info-alias.cpp index bf2dbee4659592..fbb2ad6e5ff089 100644 --- a/clang/test/CodeGenCXX/debug-info-alias.cpp +++ b/clang/test/CodeGenCXX/debug-info-alias.cpp @@ -24,7 +24,7 @@ x::bar<int> bi; // CHECK: [[BFLOAT]] = !DIDerivedType(tag: DW_TAG_typedef, name: "bar<float>" x::bar<float> bf; // CHECK: !DIGlobalVariable(name: "bz",{{.*}} type: [[BBAZ:![0-9]+]] -// CHECK: [[BBAZ]] = !DIDerivedType(tag: DW_TAG_typedef, name: "bar<baz<int> >" +// CHECK: [[BBAZ]] = !DIDerivedType(tag: DW_TAG_typedef, name: "bar<baz<int,{{ *}}int> >" x::bar<baz<int>> bz; using _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
