Add SHF_COMPRESSED support to gas and objcopy

This patch adds --compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}
options to gas and objcopy for ELF files. They control how DWARF debug
sections are compressed.  --compress-debug-sections=none is equivalent to
--nocompress-debug-sections.  --compress-debug-sections=zlib and
--compress-debug-sections=zlib-gnu are equivalent to
--compress-debug-sections.  --compress-debug-sections=zlib-gabi compresses
DWARF debug sections with SHF_COMPRESSED from the ELF ABI.  No linker
changes are required to support SHF_COMPRESSED.

bfd/

	* archive.c (_bfd_get_elt_at_filepos): Also copy BFD_COMPRESS_GABI
	bit.
	* bfd.c (bfd::flags): Increase size to 18 bits.
	(BFD_COMPRESS_GABI): New.
	(BFD_FLAGS_SAVED): Add BFD_COMPRESS_GABI.
	(BFD_FLAGS_FOR_BFD_USE_MASK): Likewise.
	(bfd_update_compression_header): New fuction.
	(bfd_check_compression_header): Likewise.
	(bfd_get_compression_header_size): Likewise.
	(bfd_is_section_compressed_with_header): Likewise.
	* compress.c (MAX_COMPRESSION_HEADER_SIZE): New.
	(bfd_compress_section_contents): Return the uncompressed size if
	the full section contents is compressed successfully.  Support
	converting from/to .zdebug* sections.
	(bfd_get_full_section_contents): Call
	bfd_get_compression_header_size to get compression header size.
	(bfd_is_section_compressed): Renamed to ...
	(bfd_is_section_compressed_with_header): This.  Add a pointer
	argument to return compression header size.
	(bfd_is_section_compressed): Use it.
	(bfd_init_section_decompress_status): Call
	bfd_get_compression_header_size to get compression header size.
	Return FALSE if uncompressed section size is 0.
	* elf.c (_bfd_elf_make_section_from_shdr): Support converting
	from/to .zdebug* sections.
	* bfd-in2.h: Regenerated.

binutils/

	* objcopy.c (do_debug_sections): Add compress_zlib,
	compress_gnu_zlib and compress_gabi_zlib.
	(copy_options): Use optional_argument on compress-debug-sections.
	(copy_usage): Update --compress-debug-sections.
	(copy_file): Handle compress_zlib, compress_gnu_zlib and
	compress_gabi_zlib.
	(copy_main): Handle
	--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
	* doc/binutils.texi: Document
	--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.

binutils/testsuite/

	* compress.exp: Add tests for
	--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
	* binutils-all/dw2-3.rS: New file.
	* binutils-all/dw2-3.rt: Likewise.
	* binutils-all/libdw2-compressedgabi.out: Likewise.

gas/

	* as.c (show_usage): Update --compress-debug-sections.
	(std_longopts): Use optional_argument on compress-debug-sections.
	(parse_args): Handle
	--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
	* as.h (compressed_debug_section_type): New.
	(flag_compress_debug): Change type to compressed_debug_section_type.
	--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.
	* write.c (compress_debug): Set BFD_COMPRESS_GABI for
	--compress-debug-sections=zlib-gabi.  Call
	bfd_get_compression_header_size to get compression header size.
	Don't rename section name for --compress-debug-sections=zlib-gabi.
	* config/tc-i386.c (compressed_debug_section_type): Set to
	COMPRESS_DEBUG_ZLIB.
	* doc/as.texinfo: Document
	--compress-debug-sections={none|zlib|zlib-gnu|zlib-gabi}.

gas/testsuite/

	* gas/i386/dw2-compressed-1.d: New file.
	* gas/i386/dw2-compressed-2.d: Likewise.
	* gas/i386/dw2-compressed-3.d: Likewise.
	* gas/i386/x86-64-dw2-compressed-2.d: Likewise.
	* gas/i386/i386.exp: Run dw2-compressed-2, dw2-compressed-1,
	dw2-compressed-3 and x86-64-dw2-compressed-2.

ld/testsuite/

	* ld-elf/compress.exp: Add a test for
	--compress-debug-sections=zlib-gabi.
	(build_tests): Add 2 tests for --compress-debug-sections=zlib-gabi.
	(run_tests): Likewise.
	Verify linker output with zlib-gabi compressed debug input.
	* ld-elf/compressed1a.d: New file.
	* ld-elf/compressed1b.d: Likewise.
	* ld-elf/compressed1c.d: Likewise.

1 files changed, 21 insertions, 3 deletions

diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h
index 81def3f..679595e 100644
--- a/bfd/bfd-in2.h
+++ b/bfd/bfd-in2.h
@@ -6323,7 +6323,7 @@ struct bfd
   ENUM_BITFIELD (bfd_direction) direction : 2;
 
   /* Format_specific flags.  */
-  flagword flags : 17;
+  flagword flags : 18;
 
   /* Values that may appear in the flags field of a BFD.  These also
      appear in the object_flags field of the bfd_target structure, where
@@ -6400,14 +6400,19 @@ struct bfd
   /* BFD is a dummy, for plugins.  */
 #define BFD_PLUGIN 0x10000
 
+  /* Compress sections in this BFD with SHF_COMPRESSED from gABI.  */
+#define BFD_COMPRESS_GABI 0x20000
+
   /* Flags bits to be saved in bfd_preserve_save.  */
 #define BFD_FLAGS_SAVED \
-  (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_PLUGIN)
+  (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_PLUGIN \
+   | BFD_COMPRESS_GABI)
 
   /* Flags bits which are for BFD use only.  */
 #define BFD_FLAGS_FOR_BFD_USE_MASK \
   (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_LINKER_CREATED \
-   | BFD_PLUGIN | BFD_TRADITIONAL_FORMAT | BFD_DETERMINISTIC_OUTPUT)
+   | BFD_PLUGIN | BFD_TRADITIONAL_FORMAT | BFD_DETERMINISTIC_OUTPUT \
+   | BFD_COMPRESS_GABI)
 
   /* Is the file descriptor being cached?  That is, can it be closed as
      needed, and re-opened when accessed later?  */
@@ -6777,6 +6782,15 @@ void bfd_emul_set_commonpagesize (const char *, bfd_vma);
 
 char *bfd_demangle (bfd *, const char *, int);
 
+void bfd_update_compression_header
+   (bfd *abfd, bfd_byte *contents, asection *sec);
+
+bfd_boolean bfd_check_compression_header
+   (bfd *abfd, bfd_byte *contents, asection *sec,
+    bfd_size_type uncompressed_size);
+
+int bfd_get_compression_header_size (bfd *abfd, asection *sec);
+
 /* Extracted from archive.c.  */
 symindex bfd_get_next_mapent
    (bfd *abfd, symindex previous, carsym **sym);
@@ -7289,6 +7303,10 @@ bfd_boolean bfd_get_full_section_contents
 void bfd_cache_section_contents
    (asection *sec, void *contents);
 
+bfd_boolean bfd_is_section_compressed_with_header
+   (bfd *abfd, asection *section,
+    int *compression_header_size_p);
+
 bfd_boolean bfd_is_section_compressed
    (bfd *abfd, asection *section);