binutils-gdb/bfd/compress.c
H.J. Lu 0ce398f106 Add --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi]
This patch adds --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi]
to ld for ELF targets to support generating compressed DWARF debug
sections.  We always generate .zdebug_* section since section names have
been finalized and they can't be changed easily when compression is
being performed.

bfd/

	* bfd-in.h (compressed_debug_section_type): New.
	* compress.c (bfd_compress_section_contents): Add an argument
	for linker write compression and always generate .zdebug_*
	section when linking.
	(bfd_init_section_compress_status): Pass FALSE to
	bfd_compress_section_contents.
	(bfd_compress_section): New function.
	* elf.c (elf_fake_sections): For linking, set SEC_ELF_COMPRESS
	on DWARF debug sections if COMPRESS_DEBUG is set and rename
	section if COMPRESS_DEBUG_GABI_ZLIB isn't set.
	(assign_file_positions_for_non_load_sections): Set sh_offset
	to -1 if SEC_ELF_COMPRESS is set.
	(assign_file_positions_except_relocs): Likwise.
	(_bfd_elf_assign_file_positions_for_relocs): Renamed to ...
	(_bfd_elf_assign_file_positions_for_non_load): This.  Change
	return time to bfd_boolean.  Compress the section if
	SEC_ELF_COMPRESS is set.
	(_bfd_elf_write_object_contents): Updated.
	(_bfd_elf_set_section_contents): Write section contents to
	the buffer if SEC_ELF_COMPRESS is set.
	* merge.c: Include "elf-bfd.h".
	(sec_merge_emit): Add arguments for contents and offset.  Write
	to contents with offset if contents isn't NULL.
	(_bfd_write_merged_section): Write section contents to the
	buffer if SEC_ELF_COMPRESS is set.  Pass contents and
	output_offset to sec_merge_emit.
	* elflink.c (bfd_elf_final_link): Allocate the buffer for
	output section contents if SEC_ELF_COMPRESS is set.
	* section.c (SEC_ELF_COMPRESS): New.
	* bfd-in2.h: Regenerated.

gas/

	* as.h (compressed_debug_section_type): Removed.

include/

	* bfdlink.h (bfd_link_info): Add compress_debug.

ld/

	* ld.texinfo: Document --compress-debug-sections=.
	* ldmain.c (main): Set BFD_COMPRESS on output_bfd if
	COMPRESS_DEBUG is set.  Set BFD_COMPRESS_GABI on output_bfd
	for COMPRESS_DEBUG_GABI_ZLIB.
	* lexsup.c (elf_static_list_options): Add
	--compress-debug-sections=.
	* emultempl/elf32.em (OPTION_COMPRESS_DEBUG): New.
	(xtra_long): Add "compress-debug-sections".
	(gld${EMULATION_NAME}_handle_option): Handle
	OPTION_COMPRESS_DEBUG.

ld/testsuite/

	* ld-elf/compress.exp (build_tests): Add tests for
	--compress-debug-sections=.
	(run_tests): Likewise.
	Add additonal tests for --compress-debug-sections=.
	* ld-elf/gabiend.rt: New file.
	* ld-elf/gabinormal.rt: Likewise.
	* ld-elf/gnubegin.rS: Likewise.
	* ld-elf/gnunormal.rS: Likewise.
	* ld-elf/zlibbegin.rS: Likewise.
	* ld-elf/zlibnormal.rS: Likewise.
2015-04-14 22:01:38 -07:00

595 lines
16 KiB
C

/* Compressed section support (intended for debug sections).
Copyright (C) 2008-2015 Free Software Foundation, Inc.
This file is part of BFD, the Binary File Descriptor library.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "sysdep.h"
#include <zlib.h>
#include "bfd.h"
#include "libbfd.h"
#include "safe-ctype.h"
#define MAX_COMPRESSION_HEADER_SIZE 24
static bfd_boolean
decompress_contents (bfd_byte *compressed_buffer,
bfd_size_type compressed_size,
bfd_byte *uncompressed_buffer,
bfd_size_type uncompressed_size)
{
z_stream strm;
int rc;
/* It is possible the section consists of several compressed
buffers concatenated together, so we uncompress in a loop. */
strm.zalloc = NULL;
strm.zfree = NULL;
strm.opaque = NULL;
strm.avail_in = compressed_size - 12;
strm.next_in = (Bytef*) compressed_buffer + 12;
strm.avail_out = uncompressed_size;
BFD_ASSERT (Z_OK == 0);
rc = inflateInit (&strm);
while (strm.avail_in > 0 && strm.avail_out > 0)
{
if (rc != Z_OK)
break;
strm.next_out = ((Bytef*) uncompressed_buffer
+ (uncompressed_size - strm.avail_out));
rc = inflate (&strm, Z_FINISH);
if (rc != Z_STREAM_END)
break;
rc = inflateReset (&strm);
}
rc |= inflateEnd (&strm);
return rc == Z_OK && strm.avail_out == 0;
}
/* Compress data of the size specified in @var{uncompressed_size}
and pointed to by @var{uncompressed_buffer} using zlib and store
as the contents field. This function assumes the contents
field was allocated using bfd_malloc() or equivalent.
Return the uncompressed size if the full section contents is
compressed successfully. Otherwise return 0. */
static bfd_size_type
bfd_compress_section_contents (bfd *abfd, sec_ptr sec,
bfd_byte *uncompressed_buffer,
bfd_size_type uncompressed_size,
bfd_boolean write_compress)
{
uLong compressed_size;
bfd_byte *buffer;
bfd_size_type buffer_size;
bfd_boolean decompress;
#if defined(__GNUC__) && GCC_VERSION < 4007
/* Work around a GCC uninitialized warning bug fixed in GCC 4.7. */
int zlib_size = 0;
#else
int zlib_size;
#endif
int orig_compression_header_size;
int compression_header_size
= bfd_get_compression_header_size (abfd, NULL);
bfd_boolean compressed
= bfd_is_section_compressed_with_header (abfd, sec,
&orig_compression_header_size);
if (compressed)
{
/* We shouldn't decompress unsupported compressed section. */
if (orig_compression_header_size < 0)
abort ();
/* Different compression schemes. Just move the compressed section
contents to the right position. */
if (orig_compression_header_size == 0)
{
/* Convert it from .zdebug* section. Get the uncompressed
size first. */
zlib_size = uncompressed_size;
compressed_size = zlib_size + compression_header_size;
uncompressed_size = bfd_getb64 (uncompressed_buffer + 4);
}
else
{
/* Convert it to .zdebug* section. */
zlib_size = uncompressed_size - orig_compression_header_size;
compressed_size = zlib_size;
}
}
else
compressed_size = compressBound (uncompressed_size) + 12;
/* When converting from .zdebug* section, uncompress if it leads to
smaller size. */
if (compressed
&& orig_compression_header_size == 0
&& compressed_size > uncompressed_size)
{
decompress = TRUE;
buffer_size = uncompressed_size;
}
else
{
decompress = FALSE;
buffer_size = compressed_size + compression_header_size;
}
buffer = (bfd_byte *) bfd_alloc (abfd, buffer_size);
if (buffer == NULL)
return 0;
if (compressed)
{
sec->size = uncompressed_size;
if (decompress)
{
if (!decompress_contents (uncompressed_buffer, zlib_size,
buffer, uncompressed_size))
{
bfd_set_error (bfd_error_bad_value);
bfd_release (abfd, buffer);
return 0;
}
free (uncompressed_buffer);
sec->contents = buffer;
sec->compress_status = COMPRESS_SECTION_DONE;
return uncompressed_size;
}
else
{
bfd_update_compression_header (abfd, buffer, sec);
memmove (buffer + compression_header_size,
uncompressed_buffer + orig_compression_header_size,
zlib_size);
}
}
else
{
bfd_size_type size = uncompressed_size;
int header_size = 12 + compression_header_size;
if (compress ((Bytef*) buffer + header_size,
&compressed_size,
(const Bytef*) uncompressed_buffer,
uncompressed_size) != Z_OK)
{
bfd_release (abfd, buffer);
bfd_set_error (bfd_error_bad_value);
return 0;
}
compressed_size += header_size;
/* PR binutils/18087: If compression didn't make the section smaller,
just keep it uncompressed. We always generate .zdebug_* section
when linking since section names have been finalized and they
can't be changed easily. */
if ((write_compress && compression_header_size == 0)
|| compressed_size < uncompressed_size)
{
bfd_update_compression_header (abfd, buffer, sec);
/* Write the zlib header. In this case, it should be "ZLIB"
followed by the uncompressed section size, 8 bytes in
big-endian order. */
memcpy (buffer + compression_header_size, "ZLIB", 4);
bfd_putb64 (size, buffer + compression_header_size + 4);
}
else
{
/* NOTE: There is a small memory leak here since
uncompressed_buffer is malloced and won't be freed. */
bfd_release (abfd, buffer);
sec->contents = uncompressed_buffer;
sec->compress_status = COMPRESS_SECTION_NONE;
return uncompressed_size;
}
}
free (uncompressed_buffer);
sec->contents = buffer;
sec->size = compressed_size;
sec->compress_status = COMPRESS_SECTION_DONE;
return uncompressed_size;
}
/*
FUNCTION
bfd_get_full_section_contents
SYNOPSIS
bfd_boolean bfd_get_full_section_contents
(bfd *abfd, asection *section, bfd_byte **ptr);
DESCRIPTION
Read all data from @var{section} in BFD @var{abfd}, decompress
if needed, and store in @var{*ptr}. If @var{*ptr} is NULL,
return @var{*ptr} with memory malloc'd by this function.
Return @code{TRUE} if the full section contents is retrieved
successfully. If the section has no contents then this function
returns @code{TRUE} but @var{*ptr} is set to NULL.
*/
bfd_boolean
bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr)
{
bfd_size_type sz;
bfd_byte *p = *ptr;
bfd_boolean ret;
bfd_size_type save_size;
bfd_size_type save_rawsize;
bfd_byte *compressed_buffer;
unsigned int compression_header_size;
if (abfd->direction != write_direction && sec->rawsize != 0)
sz = sec->rawsize;
else
sz = sec->size;
if (sz == 0)
{
*ptr = NULL;
return TRUE;
}
switch (sec->compress_status)
{
case COMPRESS_SECTION_NONE:
if (p == NULL)
{
p = (bfd_byte *) bfd_malloc (sz);
if (p == NULL)
return FALSE;
}
if (!bfd_get_section_contents (abfd, sec, p, 0, sz))
{
if (*ptr != p)
free (p);
return FALSE;
}
*ptr = p;
return TRUE;
case DECOMPRESS_SECTION_SIZED:
/* Read in the full compressed section contents. */
compressed_buffer = (bfd_byte *) bfd_malloc (sec->compressed_size);
if (compressed_buffer == NULL)
return FALSE;
save_rawsize = sec->rawsize;
save_size = sec->size;
/* Clear rawsize, set size to compressed size and set compress_status
to COMPRESS_SECTION_NONE. If the compressed size is bigger than
the uncompressed size, bfd_get_section_contents will fail. */
sec->rawsize = 0;
sec->size = sec->compressed_size;
sec->compress_status = COMPRESS_SECTION_NONE;
ret = bfd_get_section_contents (abfd, sec, compressed_buffer,
0, sec->compressed_size);
/* Restore rawsize and size. */
sec->rawsize = save_rawsize;
sec->size = save_size;
sec->compress_status = DECOMPRESS_SECTION_SIZED;
if (!ret)
goto fail_compressed;
if (p == NULL)
p = (bfd_byte *) bfd_malloc (sz);
if (p == NULL)
goto fail_compressed;
compression_header_size = bfd_get_compression_header_size (abfd, sec);
if (!decompress_contents (compressed_buffer + compression_header_size,
sec->compressed_size, p, sz))
{
bfd_set_error (bfd_error_bad_value);
if (p != *ptr)
free (p);
fail_compressed:
free (compressed_buffer);
return FALSE;
}
free (compressed_buffer);
*ptr = p;
return TRUE;
case COMPRESS_SECTION_DONE:
if (sec->contents == NULL)
return FALSE;
if (p == NULL)
{
p = (bfd_byte *) bfd_malloc (sz);
if (p == NULL)
return FALSE;
*ptr = p;
}
/* PR 17512; file: 5bc29788. */
if (p != sec->contents)
memcpy (p, sec->contents, sz);
return TRUE;
default:
abort ();
}
}
/*
FUNCTION
bfd_cache_section_contents
SYNOPSIS
void bfd_cache_section_contents
(asection *sec, void *contents);
DESCRIPTION
Stash @var(contents) so any following reads of @var(sec) do
not need to decompress again.
*/
void
bfd_cache_section_contents (asection *sec, void *contents)
{
if (sec->compress_status == DECOMPRESS_SECTION_SIZED)
sec->compress_status = COMPRESS_SECTION_DONE;
sec->contents = contents;
sec->flags |= SEC_IN_MEMORY;
}
/*
FUNCTION
bfd_is_section_compressed_with_header
SYNOPSIS
bfd_boolean bfd_is_section_compressed_with_header
(bfd *abfd, asection *section,
int *compression_header_size_p);
DESCRIPTION
Return @code{TRUE} if @var{section} is compressed. Compression
header size is returned in @var{compression_header_size_p}. If
compression is unsupported, compression header size is returned
with -1.
*/
bfd_boolean
bfd_is_section_compressed_with_header (bfd *abfd, sec_ptr sec,
int *compression_header_size_p)
{
bfd_byte header[MAX_COMPRESSION_HEADER_SIZE + 12];
int compression_header_size;
int header_size = 12;
unsigned int saved = sec->compress_status;
bfd_boolean compressed;
compression_header_size = bfd_get_compression_header_size (abfd, sec);
if (compression_header_size > MAX_COMPRESSION_HEADER_SIZE)
abort ();
header_size += compression_header_size;
/* Don't decompress the section. */
sec->compress_status = COMPRESS_SECTION_NONE;
/* Read the zlib header. In this case, it should be "ZLIB" followed
by the uncompressed section size, 8 bytes in big-endian order. */
compressed = bfd_get_section_contents (abfd, sec, header, 0,
header_size)
&& CONST_STRNEQ ((char*) header + compression_header_size,
"ZLIB");
if (compressed)
{
if (compression_header_size != 0)
{
bfd_size_type uncompressed_size
= bfd_getb64 ((bfd_byte *) header
+ compression_header_size + 4);
if (!bfd_check_compression_header (abfd, header, sec,
uncompressed_size))
compression_header_size = -1;
}
/* Check for the pathalogical case of a debug string section that
contains the string ZLIB.... as the first entry. We assume that
no uncompressed .debug_str section would ever be big enough to
have the first byte of its (big-endian) size be non-zero. */
else if (strcmp (sec->name, ".debug_str") == 0
&& ISPRINT (header[compression_header_size + 4]))
compressed = FALSE;
}
/* Restore compress_status. */
sec->compress_status = saved;
*compression_header_size_p = compression_header_size;
return compressed;
}
/*
FUNCTION
bfd_is_section_compressed
SYNOPSIS
bfd_boolean bfd_is_section_compressed
(bfd *abfd, asection *section);
DESCRIPTION
Return @code{TRUE} if @var{section} is compressed.
*/
bfd_boolean
bfd_is_section_compressed (bfd *abfd, sec_ptr sec)
{
int compression_header_size;
return (bfd_is_section_compressed_with_header (abfd, sec,
&compression_header_size)
&& compression_header_size >= 0);
}
/*
FUNCTION
bfd_init_section_decompress_status
SYNOPSIS
bfd_boolean bfd_init_section_decompress_status
(bfd *abfd, asection *section);
DESCRIPTION
Record compressed section size, update section size with
decompressed size and set compress_status to
DECOMPRESS_SECTION_SIZED.
Return @code{FALSE} if the section is not a valid compressed
section. Otherwise, return @code{TRUE}.
*/
bfd_boolean
bfd_init_section_decompress_status (bfd *abfd, sec_ptr sec)
{
bfd_byte header[MAX_COMPRESSION_HEADER_SIZE + 12];
int compression_header_size;
int header_size = 12;
bfd_size_type uncompressed_size;
compression_header_size = bfd_get_compression_header_size (abfd, sec);
if (compression_header_size > MAX_COMPRESSION_HEADER_SIZE)
abort ();
header_size += compression_header_size;
if (sec->rawsize != 0
|| sec->contents != NULL
|| sec->compress_status != COMPRESS_SECTION_NONE
|| !bfd_get_section_contents (abfd, sec, header, 0, header_size))
{
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
}
/* Read the zlib header. In this case, it should be "ZLIB" followed
by the uncompressed section size, 8 bytes in big-endian order. */
if (! CONST_STRNEQ ((char*) header + compression_header_size, "ZLIB"))
{
bfd_set_error (bfd_error_wrong_format);
return FALSE;
}
uncompressed_size = bfd_getb64 (header + compression_header_size + 4);
if (compression_header_size != 0
&& !bfd_check_compression_header (abfd, header, sec,
uncompressed_size))
{
bfd_set_error (bfd_error_wrong_format);
return FALSE;
}
sec->compressed_size = sec->size;
sec->size = uncompressed_size;
sec->compress_status = DECOMPRESS_SECTION_SIZED;
return TRUE;
}
/*
FUNCTION
bfd_init_section_compress_status
SYNOPSIS
bfd_boolean bfd_init_section_compress_status
(bfd *abfd, asection *section);
DESCRIPTION
If open for read, compress section, update section size with
compressed size and set compress_status to COMPRESS_SECTION_DONE.
Return @code{FALSE} if the section is not a valid compressed
section. Otherwise, return @code{TRUE}.
*/
bfd_boolean
bfd_init_section_compress_status (bfd *abfd, sec_ptr sec)
{
bfd_size_type uncompressed_size;
bfd_byte *uncompressed_buffer;
bfd_boolean ret;
/* Error if not opened for read. */
if (abfd->direction != read_direction
|| sec->size == 0
|| sec->rawsize != 0
|| sec->contents != NULL
|| sec->compress_status != COMPRESS_SECTION_NONE)
{
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
}
/* Read in the full section contents and compress it. */
uncompressed_size = sec->size;
uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size);
if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer,
0, uncompressed_size))
ret = FALSE;
else
{
uncompressed_size = bfd_compress_section_contents (abfd, sec,
uncompressed_buffer,
uncompressed_size,
FALSE);
ret = uncompressed_size != 0;
}
return ret;
}
/*
FUNCTION
bfd_compress_section
SYNOPSIS
bfd_boolean bfd_compress_section
(bfd *abfd, asection *section, bfd_byte *uncompressed_buffer);
DESCRIPTION
If open for write, compress section, update section size with
compressed size and set compress_status to COMPRESS_SECTION_DONE.
Return @code{FALSE} if compression fail. Otherwise, return
@code{TRUE}.
*/
bfd_boolean
bfd_compress_section (bfd *abfd, sec_ptr sec, bfd_byte *uncompressed_buffer)
{
bfd_size_type uncompressed_size = sec->size;
/* Error if not opened for write. */
if (abfd->direction != write_direction
|| uncompressed_size == 0
|| uncompressed_buffer == NULL
|| sec->contents != NULL
|| sec->compressed_size != 0
|| sec->compress_status != COMPRESS_SECTION_NONE)
{
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
}
/* Compress it. */
return bfd_compress_section_contents (abfd, sec, uncompressed_buffer,
uncompressed_size, TRUE) != 0;
}