Author: Fangrui Song Date: 2020-08-03T15:12:01-07:00 New Revision: 7cf4603faee366a6e5860b6fdbedadd91872e231
URL: https://github.com/llvm/llvm-project/commit/7cf4603faee366a6e5860b6fdbedadd91872e231 DIFF: https://github.com/llvm/llvm-project/commit/7cf4603faee366a6e5860b6fdbedadd91872e231.diff LOG: Reland D61689 Change -gz and -Wa,--compress-debug-sections to use gABI compression (SHF_COMPRESSED) with integrated assembler This fixes an inconsistency: clang -c -gz -fno-integrated-as means SHF_COMPRESSED while clang -c -gz -fintegrated-as means zlib-gnu. --- Since July 15, 2015 (binutils-gdb commit 19a7fe52ae3d0971e67a134bcb1648899e21ae1c, included in 2.26), gas --compress-debug-sections=zlib (gcc -gz) means zlib-gabi: SHF_COMPRESSED. Before that GCC/binutils used zlib-gnu (.zdebug). clang's -gz was introduced in rC306115 (Jun 2017) to indicate zlib-gnu. It is 2020 now and it is not unreasonable to assume users of the new feature to have new linkers (ld.bfd/gold >= 2.26, lld >= rLLD273661). Change clang's default accordingly to improve standard conformance. zlib-gnu becomes out of fashion and gets poorer toolchain support. Its mangled names confuse tools and are more likely to cause problems. Reviewed By: compnerd Differential Revision: https://reviews.llvm.org/D61689 Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/Frontend/CompilerInvocation.cpp clang/tools/driver/cc1as_main.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 9274081c4d62..03eca8a26843 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -100,7 +100,10 @@ future versions of Clang. Modified Compiler Flags ----------------------- -- ... +- On ELF, ``-gz`` now defaults to ``-gz=zlib`` with the integrated assembler. + It produces ``SHF_COMPRESSED`` style compression of debug information. GNU + binutils 2.26 or newer, or lld is required to link produced object files. Use + ``-gz=zlib-gnu`` to get the old behavior. New Pragmas in Clang -------------------- diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp index 0b5f33541060..8e8bf9d9028e 100644 --- a/clang/lib/Frontend/CompilerInvocation.cpp +++ b/clang/lib/Frontend/CompilerInvocation.cpp @@ -1155,8 +1155,7 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK, if (const Arg *A = Args.getLastArg(OPT_compress_debug_sections, OPT_compress_debug_sections_EQ)) { if (A->getOption().getID() == OPT_compress_debug_sections) { - // TODO: be more clever about the compression type auto-detection - Opts.setCompressDebugSections(llvm::DebugCompressionType::GNU); + Opts.setCompressDebugSections(llvm::DebugCompressionType::Z); } else { auto DCT = llvm::StringSwitch<llvm::DebugCompressionType>(A->getValue()) .Case("none", llvm::DebugCompressionType::None) diff --git a/clang/tools/driver/cc1as_main.cpp b/clang/tools/driver/cc1as_main.cpp index 77b99b201364..87047be3c2bc 100644 --- a/clang/tools/driver/cc1as_main.cpp +++ b/clang/tools/driver/cc1as_main.cpp @@ -224,8 +224,7 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts, if (const Arg *A = Args.getLastArg(OPT_compress_debug_sections, OPT_compress_debug_sections_EQ)) { if (A->getOption().getID() == OPT_compress_debug_sections) { - // TODO: be more clever about the compression type auto-detection - Opts.CompressDebugSections = llvm::DebugCompressionType::GNU; + Opts.CompressDebugSections = llvm::DebugCompressionType::Z; } else { Opts.CompressDebugSections = llvm::StringSwitch<llvm::DebugCompressionType>(A->getValue()) _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits