https://github.com/ayermolo created https://github.com/llvm/llvm-project/pull/83331
When -gsplit-dwarf is passed in clang emmmits -ggnu-pubnames which results in .debug_gnu_pubnames/..debug_gnu_pubtypes being generated. This is used by GDB, but not by LLDB. Changed so that these sections are not emitted for LLDB tuning. >From 668819ef921ecb4d0ef704c2269ea07acd1b5334 Mon Sep 17 00:00:00 2001 From: Alexander Yermolovich <ayerm...@meta.com> Date: Fri, 23 Feb 2024 14:52:04 -0800 Subject: [PATCH 1/2] [CLANG][DWARF] Do not emit -ggnu-pubnames for split dwarf version 5. When -gsplit-dwarf is passed in clang emmmits -ggnu-pubnames which results in .debug_gnu_pubnames/..debug_gnu_pubtypes being generated. For DWARF5 we have functional .debug_names. TBH not sure what the right behavior should be. Should we not generate anything at all by default or generate .debug_names? Doing some archeological digging initially -gnu-pubnames was always generated to be in line with what gcc does.. It was then changed so that it was generated when split-dwarf was enabled: https://github.com/llvm/llvm-project/commit/658645241bf0c624d4b7a67c195c239bbc193e3f#diff-bac41c71569f27df21a843bcd74d2e604ed508afbdf141777761dfb545c5d228 For LLDB these gnu sections are not useful and just waste space. Maybe a better check is to be based on tunning? --- clang/lib/Driver/ToolChains/Clang.cpp | 7 ++++--- clang/test/Driver/split-debug.c | 1 - 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index 66c3a237c12117..da3930c1c9697b 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -4479,9 +4479,10 @@ renderDebugOptions(const ToolChain &TC, const Driver &D, const llvm::Triple &T, options::OPT_gpubnames, options::OPT_gno_pubnames); if (DwarfFission != DwarfFissionKind::None || (PubnamesArg && checkDebugInfoOption(PubnamesArg, Args, D, TC))) - if (!PubnamesArg || - (!PubnamesArg->getOption().matches(options::OPT_gno_gnu_pubnames) && - !PubnamesArg->getOption().matches(options::OPT_gno_pubnames))) + if (EffectiveDWARFVersion < 5 && + (!PubnamesArg || + (!PubnamesArg->getOption().matches(options::OPT_gno_gnu_pubnames) && + !PubnamesArg->getOption().matches(options::OPT_gno_pubnames)))) CmdArgs.push_back(PubnamesArg && PubnamesArg->getOption().matches( options::OPT_gpubnames) ? "-gpubnames" diff --git a/clang/test/Driver/split-debug.c b/clang/test/Driver/split-debug.c index 968f33b4cc035c..1d5f0fa42fdeea 100644 --- a/clang/test/Driver/split-debug.c +++ b/clang/test/Driver/split-debug.c @@ -11,7 +11,6 @@ // NOINLINE-NOT: "-fsplit-dwarf-inlining" // SPLIT-NOT: "-dumpdir" // SPLIT: "-debug-info-kind=constructor" -// SPLIT-SAME: "-ggnu-pubnames" // SPLIT-SAME: "-split-dwarf-file" "split-debug.dwo" "-split-dwarf-output" "split-debug.dwo" // RUN: %clang -### -c -target wasm32 -gsplit-dwarf -g %s 2>&1 | FileCheck %s --check-prefix=SPLIT >From b458d52dbaa3589b728969f6cb630c4602cf1216 Mon Sep 17 00:00:00 2001 From: Alexander Yermolovich <ayerm...@meta.com> Date: Wed, 28 Feb 2024 13:01:02 -0800 Subject: [PATCH 2/2] [CLANG][DWARF] Do not emit -ggnu-pubnames for split dwarf version 5 When -gsplit-dwarf is passed in clang emmmits -ggnu-pubnames which results in .debug_gnu_pubnames/..debug_gnu_pubtypes being generated. This is used by GDB, but not by LLDB. Changed so that these sections are not emitted for LLDB tuning, unless flag is passed explicitly. --- clang/lib/Driver/ToolChains/Clang.cpp | 9 +++++++-- clang/test/Driver/split-debug.c | 10 ++++++++++ 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index da3930c1c9697b..2dc42119973caf 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -4478,8 +4478,12 @@ renderDebugOptions(const ToolChain &TC, const Driver &D, const llvm::Triple &T, Args.getLastArg(options::OPT_ggnu_pubnames, options::OPT_gno_gnu_pubnames, options::OPT_gpubnames, options::OPT_gno_pubnames); if (DwarfFission != DwarfFissionKind::None || - (PubnamesArg && checkDebugInfoOption(PubnamesArg, Args, D, TC))) - if (EffectiveDWARFVersion < 5 && + (PubnamesArg && checkDebugInfoOption(PubnamesArg, Args, D, TC))) { + const bool OptionSet = + (PubnamesArg && + (PubnamesArg->getOption().matches(options::OPT_gpubnames) || + PubnamesArg->getOption().matches(options::OPT_ggnu_pubnames))); + if ((DebuggerTuning != llvm::DebuggerKind::LLDB || OptionSet) && (!PubnamesArg || (!PubnamesArg->getOption().matches(options::OPT_gno_gnu_pubnames) && !PubnamesArg->getOption().matches(options::OPT_gno_pubnames)))) @@ -4487,6 +4491,7 @@ renderDebugOptions(const ToolChain &TC, const Driver &D, const llvm::Triple &T, options::OPT_gpubnames) ? "-gpubnames" : "-ggnu-pubnames"); + } const auto *SimpleTemplateNamesArg = Args.getLastArg(options::OPT_gsimple_template_names, options::OPT_gno_simple_template_names); diff --git a/clang/test/Driver/split-debug.c b/clang/test/Driver/split-debug.c index 1d5f0fa42fdeea..e297724931045c 100644 --- a/clang/test/Driver/split-debug.c +++ b/clang/test/Driver/split-debug.c @@ -123,3 +123,13 @@ // G1_NOSPLIT: "-debug-info-kind=line-tables-only" // G1_NOSPLIT-NOT: "-split-dwarf-file" // G1_NOSPLIT-NOT: "-split-dwarf-output" + +/// Do not generate -ggnu-pubnames for -glldb +// RUN: %clang -### -c -target x86_64 -gsplit-dwarf -g -glldb %s 2>&1 | FileCheck %s --check-prefixes=GLLDBSPLIT + +// GLLDBSPLIT-NOT: "-ggnu-pubnames" + +/// Generate -ggnu-pubnames for -glldb when it is explicitly enabled +// RUN: %clang -### -c -target x86_64 -gsplit-dwarf -g -glldb -ggnu-pubnames %s 2>&1 | FileCheck %s --check-prefixes=GLLDBSPLIT2 + +// GLLDBSPLIT2: "-ggnu-pubnames" _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
