From 7afbac7ddd7299491a88341149bc72b38173447a Mon Sep 17 00:00:00 2001 From: Martin Liska Date: Thu, 29 Sep 2022 14:10:30 +0200 Subject: [PATCH] compress .gnu.debuglto_.debug_* sections if requested Right now, when using LTO, the intermediate object files do contain debug info in sections starting with .gnu.debuglto_ prefix and are not compressed when --compress-debug-sections is used. It's a mistake and we can save quite some disk space. The following example comes from tramp3d when the corresponding LTO sections are compressed with zlib: $ bloaty tramp3d-v4-v2.o -- tramp3d-v4.o FILE SIZE VM SIZE -------------- -------------- +83% +10 [ = ] 0 [Unmapped] -68.0% -441 [ = ] 0 .gnu.debuglto_.debug_line -52.3% -759 [ = ] 0 .gnu.debuglto_.debug_line_str -62.4% -3.24Ki [ = ] 0 .gnu.debuglto_.debug_abbrev -64.8% -1.12Mi [ = ] 0 .gnu.debuglto_.debug_info -88.8% -4.58Mi [ = ] 0 .gnu.debuglto_.debug_str -27.7% -5.70Mi [ = ] 0 TOTAL bfd/ChangeLog: * elf.c (_bfd_elf_make_section_from_shdr): Compress all debug info sections. gas/ChangeLog: * write.c (compress_debug): Compress also ".gnu.debuglto_.debug_" if the compression algorithm is different from zlib-gnu. --- bfd/elf.c | 7 +++---- gas/write.c | 4 +++- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/bfd/elf.c b/bfd/elf.c index d496c1b2983..8cd257fc65c 100644 --- a/bfd/elf.c +++ b/bfd/elf.c @@ -1199,12 +1199,11 @@ _bfd_elf_make_section_from_shdr (bfd *abfd, } } - /* Compress/decompress DWARF debug sections with names: .debug_* and - .zdebug_*, after the section flags is set. */ + /* Compress/decompress DWARF debug sections with names: .debug_*, + .zdebug_*, .gnu.debuglto_.debug_, after the section flags is set. */ if ((newsect->flags & SEC_DEBUGGING) != 0 && (newsect->flags & SEC_HAS_CONTENTS) != 0 - && ((name[1] == 'd' && name[6] == '_') - || (name[1] == 'z' && name[7] == '_'))) + && (newsect->flags & SEC_ELF_OCTETS) != 0) { enum { nothing, compress, decompress } action = nothing; int compression_header_size; diff --git a/gas/write.c b/gas/write.c index 0e49df7c03f..b8d5253006c 100644 --- a/gas/write.c +++ b/gas/write.c @@ -1481,7 +1481,9 @@ compress_debug (bfd *abfd, asection *sec, void *xxx ATTRIBUTE_UNUSED) return; section_name = bfd_section_name (sec); - if (!startswith (section_name, ".debug_")) + if (!startswith (section_name, ".debug_") + && (!startswith (section_name, ".gnu.debuglto_.debug_") + || flag_compress_debug == COMPRESS_DEBUG_GNU_ZLIB)) return; bool use_zstd = abfd->flags & BFD_COMPRESS_ZSTD; -- 2.30.2