libbacktrace: support zstd decompression

Support decompressing --compress-debug-sections=zstd.
	* configure.ac: Check for zstd library and
	--compress-debug-sections=zstd linker option.
	* Makefile.am (zstdtest_*): New targets.
	(zstdtest_alloc_*, ctestzstd_*): New targets.
	(BUILDTESTS): Add zstdtest, zstdtest_alloc, ctestzstd as
	appropriate.
	* elf.c (ELFCOMPRESS_ZSTD): Define.
	(elf_fetch_bits): Rename from elf_zlib_fetch.  Update uses.
	(elf_fetch_bits_backward): New static function.
	(ZLIB_HUFFMAN_*): Rename from HUFFMAN_*.  Update uses.
	(ZLIB_TABLE_*): Rename from ZDEBUG_TABLE_*.  Update uses.
	(ZSTD_TABLE_*): Define.
	(struct elf_zstd_fse_entry): Define.
	(elf_zstd_read_fse): New static function.
	(elf_zstd_build_fse): Likewise.
	(lit): Define if BACKTRACE_GENERATE_ZSTD_FSE_TABLES.
	(match, offset, next, print_table, main): Likewise.
	(elf_zstd_lit_table): New static const array.
	(elf_zstd_match_table, elf_zstd_offset_table): Likewise.
	(elf_zstd_read_huff): New static function.
	(struct elf_zstd_seq_decode): Define.
	(elf_zstd_unpack_seq_decode): New static function.
	(ZSTD_LIT_*): Define.
	(struct elf_zstd_literals): Define.
	(elf_zstd_literal_output): New static function.
	(ZSTD_LITERAL_LENGTH_BASELINE_OFFSET): Define.
	(elf_zstd_literal_length_baseline): New static const array.
	(elf_zstd_literal_length_bits): Likewise.
	(ZSTD_MATCH_LENGTH_BASELINE_OFFSET): Define.
	(elf_zstd_match_length_baseline): New static const array.
	(elf_zstd_match_length_bits): Likewise.
	(elf_zstd_decompress): New static function.
	(ZDEBUG_TABLE_SIZE): New definition.
	(elf_uncompress_chdr): Support ELF_COMPRESS_ZSTD.
	(backtrace_uncompress_zstd): New function.
	(elf_add): Use ZLIB_TABLE_SIZE for zlib-gnu sections.
	* internal.h (backtrace_uncompress_zstd): Declare.
	* zstdtest.c: New file.
	* configure, config.h.in, Makefile.in: Regenerate.
This commit is contained in:
Ian Lance Taylor
2022-12-07 16:21:26 -08:00
parent 8602fda64e
commit c992dd8a9b
8 changed files with 3165 additions and 110 deletions

View File

@@ -492,6 +492,21 @@ AC_LINK_IFELSE([AC_LANG_PROGRAM(,)],
LDFLAGS=$LDFLAGS_hold])
AM_CONDITIONAL(HAVE_COMPRESSED_DEBUG, test "$libgo_cv_ld_compress" = yes)
AC_CHECK_LIB([zstd], [ZSTD_compress],
[AC_DEFINE(HAVE_ZSTD, 1, [Define if -lzstd is available.])])
AM_CONDITIONAL(HAVE_ZSTD, test "$ac_cv_lib_zstd_ZSTD_compress" = yes)
dnl Test whether the linker supports --compress-debug-sections=zstd option.
AC_CACHE_CHECK([whether --compress-debug-sections=zstd is supported],
[libgo_cv_ld_compress_zstd],
[LDFLAGS_hold=$LDFLAGS
LDFLAGS="$LDFLAGS -Wl,--compress-debug-sections=zstd"
AC_LINK_IFELSE([AC_LANG_PROGRAM(,)],
[libgo_cv_ld_compress_zstd=yes],
[libgo_cv_ld_compress_zstd=no])
LDFLAGS=$LDFLAGS_hold])
AM_CONDITIONAL(HAVE_COMPRESSED_DEBUG_ZSTD, test "$libgo_cv_ld_compress_zstd" = yes)
AC_ARG_VAR(OBJCOPY, [location of objcopy])
AC_CHECK_PROG(OBJCOPY, objcopy, objcopy,)
AC_CHECK_PROG(READELF, readelf, readelf)