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Diffstat (limited to 'binutils-2.25/bfd/compress.c')
| -rw-r--r-- | binutils-2.25/bfd/compress.c | 429 |
1 files changed, 429 insertions, 0 deletions
diff --git a/binutils-2.25/bfd/compress.c b/binutils-2.25/bfd/compress.c new file mode 100644 index 00000000..46c2bcba --- /dev/null +++ b/binutils-2.25/bfd/compress.c @@ -0,0 +1,429 @@ +/* Compressed section support (intended for debug sections). + Copyright 2008, 2010, 2011, 2012 + 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 "bfd.h" +#include "libbfd.h" +#ifdef HAVE_ZLIB_H +#include <zlib.h> +#endif + +#ifdef HAVE_ZLIB_H +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; +} +#endif + +/* +FUNCTION + bfd_compress_section_contents + +SYNOPSIS + bfd_boolean bfd_compress_section_contents + (bfd *abfd, asection *section, bfd_byte *uncompressed_buffer, + bfd_size_type uncompressed_size); + +DESCRIPTION + + 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. If zlib + is not installed on this machine, the input is unmodified. + + Return @code{TRUE} if the full section contents is compressed + successfully. +*/ + +bfd_boolean +bfd_compress_section_contents (bfd *abfd ATTRIBUTE_UNUSED, + sec_ptr sec ATTRIBUTE_UNUSED, + bfd_byte *uncompressed_buffer ATTRIBUTE_UNUSED, + bfd_size_type uncompressed_size ATTRIBUTE_UNUSED) +{ +#ifndef HAVE_ZLIB_H + bfd_set_error (bfd_error_invalid_operation); + return FALSE; +#else + uLong compressed_size; + bfd_byte *compressed_buffer; + + compressed_size = compressBound (uncompressed_size) + 12; + compressed_buffer = (bfd_byte *) bfd_malloc (compressed_size); + + if (compressed_buffer == NULL) + return FALSE; + + if (compress ((Bytef*) compressed_buffer + 12, + &compressed_size, + (const Bytef*) uncompressed_buffer, + uncompressed_size) != Z_OK) + { + free (compressed_buffer); + bfd_set_error (bfd_error_bad_value); + return FALSE; + } + + /* Write the zlib header. In this case, it should be "ZLIB" followed + by the uncompressed section size, 8 bytes in big-endian order. */ + memcpy (compressed_buffer, "ZLIB", 4); + compressed_buffer[11] = uncompressed_size; uncompressed_size >>= 8; + compressed_buffer[10] = uncompressed_size; uncompressed_size >>= 8; + compressed_buffer[9] = uncompressed_size; uncompressed_size >>= 8; + compressed_buffer[8] = uncompressed_size; uncompressed_size >>= 8; + compressed_buffer[7] = uncompressed_size; uncompressed_size >>= 8; + compressed_buffer[6] = uncompressed_size; uncompressed_size >>= 8; + compressed_buffer[5] = uncompressed_size; uncompressed_size >>= 8; + compressed_buffer[4] = uncompressed_size; + compressed_size += 12; + + /* Free the uncompressed contents if we compress in place. */ + if (uncompressed_buffer == sec->contents) + free (uncompressed_buffer); + + sec->contents = compressed_buffer; + sec->size = compressed_size; + sec->compress_status = COMPRESS_SECTION_DONE; + + return TRUE; +#endif /* HAVE_ZLIB_H */ +} + +/* +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. +*/ + +bfd_boolean +bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr) +{ + bfd_size_type sz; + bfd_byte *p = *ptr; +#ifdef HAVE_ZLIB_H + bfd_boolean ret; + bfd_size_type save_size; + bfd_size_type save_rawsize; + bfd_byte *compressed_buffer; +#endif + + if (abfd->direction != write_direction && sec->rawsize != 0) + sz = sec->rawsize; + else + sz = sec->size; + if (sz == 0) + 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: +#ifndef HAVE_ZLIB_H + bfd_set_error (bfd_error_invalid_operation); + return FALSE; +#else + /* 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; + + if (!decompress_contents (compressed_buffer, 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; +#endif + + case COMPRESS_SECTION_DONE: + if (p == NULL) + { + p = (bfd_byte *) bfd_malloc (sz); + if (p == NULL) + return FALSE; + *ptr = p; + } + 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 + +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) +{ + bfd_byte compressed_buffer [12]; + unsigned int saved = sec->compress_status; + bfd_boolean compressed; + + /* 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, compressed_buffer, 0, 12) + && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB")); + + /* Restore compress_status. */ + sec->compress_status = saved; + return compressed; +} + +/* +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 or zlib is not installed on this machine. Otherwise, + return @code{TRUE}. +*/ + +bfd_boolean +bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED, + sec_ptr sec ATTRIBUTE_UNUSED) +{ +#ifndef HAVE_ZLIB_H + bfd_set_error (bfd_error_invalid_operation); + return FALSE; +#else + bfd_byte compressed_buffer [12]; + bfd_size_type uncompressed_size; + + if (sec->rawsize != 0 + || sec->contents != NULL + || sec->compress_status != COMPRESS_SECTION_NONE + || !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)) + { + 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*) compressed_buffer, "ZLIB")) + { + bfd_set_error (bfd_error_wrong_format); + 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]; + + sec->compressed_size = sec->size; + sec->size = uncompressed_size; + sec->compress_status = DECOMPRESS_SECTION_SIZED; + + return TRUE; +#endif +} + +/* +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 or zlib is not installed on this machine. Otherwise, + return @code{TRUE}. +*/ + +bfd_boolean +bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED, + sec_ptr sec ATTRIBUTE_UNUSED) +{ +#ifndef HAVE_ZLIB_H + bfd_set_error (bfd_error_invalid_operation); + return FALSE; +#else + 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 + ret = bfd_compress_section_contents (abfd, sec, + uncompressed_buffer, + uncompressed_size); + + free (uncompressed_buffer); + return ret; +#endif +} |