1 /* Compressed section support (intended for debug sections).
2 Copyright (C) 2008-2015 Free Software Foundation, Inc.
4 This file is part of BFD, the Binary File Descriptor library.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19 MA 02110-1301, USA. */
27 #include "safe-ctype.h"
31 decompress_contents (bfd_byte *compressed_buffer,
32 bfd_size_type compressed_size,
33 bfd_byte *uncompressed_buffer,
34 bfd_size_type uncompressed_size)
39 /* It is possible the section consists of several compressed
40 buffers concatenated together, so we uncompress in a loop. */
44 strm.avail_in = compressed_size - 12;
45 strm.next_in = (Bytef*) compressed_buffer + 12;
46 strm.avail_out = uncompressed_size;
48 BFD_ASSERT (Z_OK == 0);
49 rc = inflateInit (&strm);
50 while (strm.avail_in > 0 && strm.avail_out > 0)
54 strm.next_out = ((Bytef*) uncompressed_buffer
55 + (uncompressed_size - strm.avail_out));
56 rc = inflate (&strm, Z_FINISH);
57 if (rc != Z_STREAM_END)
59 rc = inflateReset (&strm);
61 rc |= inflateEnd (&strm);
62 return rc == Z_OK && strm.avail_out == 0;
65 /* Compress data of the size specified in @var{uncompressed_size}
66 and pointed to by @var{uncompressed_buffer} using zlib and store
67 as the contents field. This function assumes the contents
68 field was allocated using bfd_malloc() or equivalent. If zlib
69 is not installed on this machine, the input is unmodified.
71 Return @code{TRUE} if the full section contents is compressed
75 bfd_compress_section_contents (bfd *abfd ATTRIBUTE_UNUSED,
76 sec_ptr sec ATTRIBUTE_UNUSED,
77 bfd_byte *uncompressed_buffer ATTRIBUTE_UNUSED,
78 bfd_size_type uncompressed_size ATTRIBUTE_UNUSED)
80 uLong compressed_size;
81 bfd_byte *compressed_buffer;
83 compressed_size = compressBound (uncompressed_size) + 12;
84 compressed_buffer = (bfd_byte *) bfd_malloc (compressed_size);
86 if (compressed_buffer == NULL)
89 if (compress ((Bytef*) compressed_buffer + 12,
91 (const Bytef*) uncompressed_buffer,
92 uncompressed_size) != Z_OK)
94 free (compressed_buffer);
95 bfd_set_error (bfd_error_bad_value);
99 compressed_size += 12;
101 /* PR binutils/18087: If compression didn't make the section smaller,
102 just keep it uncompressed. */
103 if (compressed_size < uncompressed_size)
105 /* Write the zlib header. In this case, it should be "ZLIB" followed
106 by the uncompressed section size, 8 bytes in big-endian order. */
107 memcpy (compressed_buffer, "ZLIB", 4);
108 compressed_buffer[11] = uncompressed_size; uncompressed_size >>= 8;
109 compressed_buffer[10] = uncompressed_size; uncompressed_size >>= 8;
110 compressed_buffer[9] = uncompressed_size; uncompressed_size >>= 8;
111 compressed_buffer[8] = uncompressed_size; uncompressed_size >>= 8;
112 compressed_buffer[7] = uncompressed_size; uncompressed_size >>= 8;
113 compressed_buffer[6] = uncompressed_size; uncompressed_size >>= 8;
114 compressed_buffer[5] = uncompressed_size; uncompressed_size >>= 8;
115 compressed_buffer[4] = uncompressed_size;
117 free (uncompressed_buffer);
118 sec->contents = compressed_buffer;
119 sec->size = compressed_size;
120 sec->compress_status = COMPRESS_SECTION_DONE;
124 sec->contents = uncompressed_buffer;
125 sec->compress_status = COMPRESS_SECTION_NONE;
130 #endif /* HAVE_ZLIB_H */
134 bfd_get_full_section_contents
137 bfd_boolean bfd_get_full_section_contents
138 (bfd *abfd, asection *section, bfd_byte **ptr);
141 Read all data from @var{section} in BFD @var{abfd}, decompress
142 if needed, and store in @var{*ptr}. If @var{*ptr} is NULL,
143 return @var{*ptr} with memory malloc'd by this function.
145 Return @code{TRUE} if the full section contents is retrieved
146 successfully. If the section has no contents then this function
147 returns @code{TRUE} but @var{*ptr} is set to NULL.
151 bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr)
157 bfd_size_type save_size;
158 bfd_size_type save_rawsize;
159 bfd_byte *compressed_buffer;
162 if (abfd->direction != write_direction && sec->rawsize != 0)
172 switch (sec->compress_status)
174 case COMPRESS_SECTION_NONE:
177 p = (bfd_byte *) bfd_malloc (sz);
182 if (!bfd_get_section_contents (abfd, sec, p, 0, sz))
191 case DECOMPRESS_SECTION_SIZED:
193 bfd_set_error (bfd_error_invalid_operation);
196 /* Read in the full compressed section contents. */
197 compressed_buffer = (bfd_byte *) bfd_malloc (sec->compressed_size);
198 if (compressed_buffer == NULL)
200 save_rawsize = sec->rawsize;
201 save_size = sec->size;
202 /* Clear rawsize, set size to compressed size and set compress_status
203 to COMPRESS_SECTION_NONE. If the compressed size is bigger than
204 the uncompressed size, bfd_get_section_contents will fail. */
206 sec->size = sec->compressed_size;
207 sec->compress_status = COMPRESS_SECTION_NONE;
208 ret = bfd_get_section_contents (abfd, sec, compressed_buffer,
209 0, sec->compressed_size);
210 /* Restore rawsize and size. */
211 sec->rawsize = save_rawsize;
212 sec->size = save_size;
213 sec->compress_status = DECOMPRESS_SECTION_SIZED;
215 goto fail_compressed;
218 p = (bfd_byte *) bfd_malloc (sz);
220 goto fail_compressed;
222 if (!decompress_contents (compressed_buffer, sec->compressed_size, p, sz))
224 bfd_set_error (bfd_error_bad_value);
228 free (compressed_buffer);
232 free (compressed_buffer);
237 case COMPRESS_SECTION_DONE:
238 if (sec->contents == NULL)
242 p = (bfd_byte *) bfd_malloc (sz);
247 /* PR 17512; file: 5bc29788. */
248 if (p != sec->contents)
249 memcpy (p, sec->contents, sz);
259 bfd_cache_section_contents
262 void bfd_cache_section_contents
263 (asection *sec, void *contents);
266 Stash @var(contents) so any following reads of @var(sec) do
267 not need to decompress again.
271 bfd_cache_section_contents (asection *sec, void *contents)
273 if (sec->compress_status == DECOMPRESS_SECTION_SIZED)
274 sec->compress_status = COMPRESS_SECTION_DONE;
275 sec->contents = contents;
276 sec->flags |= SEC_IN_MEMORY;
282 bfd_is_section_compressed
285 bfd_boolean bfd_is_section_compressed
286 (bfd *abfd, asection *section);
289 Return @code{TRUE} if @var{section} is compressed.
293 bfd_is_section_compressed (bfd *abfd, sec_ptr sec)
295 bfd_byte compressed_buffer [12];
296 unsigned int saved = sec->compress_status;
297 bfd_boolean compressed;
299 /* Don't decompress the section. */
300 sec->compress_status = COMPRESS_SECTION_NONE;
302 /* Read the zlib header. In this case, it should be "ZLIB" followed
303 by the uncompressed section size, 8 bytes in big-endian order. */
304 compressed = (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)
305 && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"));
307 /* Check for the pathalogical case of a debug string section that
308 contains the string ZLIB.... as the first entry. We assume that
309 no uncompressed .debug_str section would ever be big enough to
310 have the first byte of its (big-endian) size be non-zero. */
312 && strcmp (sec->name, ".debug_str") == 0
313 && ISPRINT (compressed_buffer[4]))
316 /* Restore compress_status. */
317 sec->compress_status = saved;
323 bfd_init_section_decompress_status
326 bfd_boolean bfd_init_section_decompress_status
327 (bfd *abfd, asection *section);
330 Record compressed section size, update section size with
331 decompressed size and set compress_status to
332 DECOMPRESS_SECTION_SIZED.
334 Return @code{FALSE} if the section is not a valid compressed
335 section or zlib is not installed on this machine. Otherwise,
340 bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED,
341 sec_ptr sec ATTRIBUTE_UNUSED)
344 bfd_set_error (bfd_error_invalid_operation);
347 bfd_byte compressed_buffer [12];
348 bfd_size_type uncompressed_size;
350 if (sec->rawsize != 0
351 || sec->contents != NULL
352 || sec->compress_status != COMPRESS_SECTION_NONE
353 || !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12))
355 bfd_set_error (bfd_error_invalid_operation);
359 /* Read the zlib header. In this case, it should be "ZLIB" followed
360 by the uncompressed section size, 8 bytes in big-endian order. */
361 if (! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"))
363 bfd_set_error (bfd_error_wrong_format);
367 uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8;
368 uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8;
369 uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8;
370 uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8;
371 uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8;
372 uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8;
373 uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8;
374 uncompressed_size += compressed_buffer[11];
376 sec->compressed_size = sec->size;
377 sec->size = uncompressed_size;
378 sec->compress_status = DECOMPRESS_SECTION_SIZED;
386 bfd_init_section_compress_status
389 bfd_boolean bfd_init_section_compress_status
390 (bfd *abfd, asection *section);
393 If open for read, compress section, update section size with
394 compressed size and set compress_status to COMPRESS_SECTION_DONE.
396 Return @code{FALSE} if the section is not a valid compressed
397 section or zlib is not installed on this machine. Otherwise,
402 bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED,
403 sec_ptr sec ATTRIBUTE_UNUSED)
406 bfd_set_error (bfd_error_invalid_operation);
409 bfd_size_type uncompressed_size;
410 bfd_byte *uncompressed_buffer;
413 /* Error if not opened for read. */
414 if (abfd->direction != read_direction
417 || sec->contents != NULL
418 || sec->compress_status != COMPRESS_SECTION_NONE)
420 bfd_set_error (bfd_error_invalid_operation);
424 /* Read in the full section contents and compress it. */
425 uncompressed_size = sec->size;
426 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size);
427 if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer,
428 0, uncompressed_size))
431 ret = bfd_compress_section_contents (abfd, sec,