binutils-gdb/bfd/compress.c

123 lines
4.0 KiB
C

/* ELF attributes support (based on ARM EABI attributes).
Copyright 2008
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 "config.h"
#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
#ifdef HAVE_ZLIB_H
#include <zlib.h>
#endif
/*
FUNCTION
bfd_uncompress_section_contents
SYNOPSIS
bfd_boolean bfd_uncompress_section_contents
(bfd_byte **buffer, bfd_size_type *size);
DESCRIPTION
Uncompresses a section that was compressed using zlib, in place. At
the call to this function, *@var{buffer} and *@var{size} should point
to the section contents to be uncompressed. At the end of the
function, *@var{buffer} and *@var{size} will point to the uncompressed
contents. This function assumes *BUFFER was allocated using
bfd_malloc() or equivalent. If the section is not a valid compressed
section, or zlib is not installed on this machine, the input is
unmodified.
Returns @code{FALSE} if unable to uncompress successfully; in that case
the input is unmodified. Otherwise, returns @code{TRUE}.
*/
bfd_boolean
bfd_uncompress_section_contents (bfd_byte **buffer, bfd_size_type *size)
{
#ifndef HAVE_ZLIB_H
/* These are just to quiet gcc. */
buffer = 0;
size = 0;
return FALSE;
#else
bfd_size_type compressed_size = *size;
bfd_byte *compressed_buffer = *buffer;
bfd_size_type uncompressed_size;
bfd_byte *uncompressed_buffer;
z_stream strm;
int rc;
bfd_size_type header_size = 12;
/* Read the zlib header. In this case, it should be "ZLIB" followed
by the uncompressed section size, 8 bytes in big-endian order. */
if (compressed_size < header_size
|| ! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"))
return FALSE;
uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8;
uncompressed_size += compressed_buffer[11];
/* 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 - header_size;
strm.next_in = (Bytef*) compressed_buffer + header_size;
strm.avail_out = uncompressed_size;
uncompressed_buffer = bfd_malloc (uncompressed_size);
if (! uncompressed_buffer)
return FALSE;
rc = inflateInit (&strm);
while (strm.avail_in > 0)
{
if (rc != Z_OK)
goto fail;
strm.next_out = ((Bytef*) uncompressed_buffer
+ (uncompressed_size - strm.avail_out));
rc = inflate (&strm, Z_FINISH);
if (rc != Z_STREAM_END)
goto fail;
rc = inflateReset (&strm);
}
rc = inflateEnd (&strm);
if (rc != Z_OK
|| strm.avail_out != 0)
goto fail;
free (compressed_buffer);
*buffer = uncompressed_buffer;
*size = uncompressed_size;
return TRUE;
fail:
free (uncompressed_buffer);
return FALSE;
#endif /* HAVE_ZLIB_H */
}