1 /* Low-level I/O routines for BFDs.
3 Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
6 Written by Cygnus Support.
8 This file is part of BFD, the Binary File Descriptor library.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
32 #define S_IXUSR 0100 /* Execute by owner. */
35 #define S_IXGRP 0010 /* Execute by group. */
38 #define S_IXOTH 0001 /* Execute by others. */
42 real_ftell (FILE *file)
44 #if defined (HAVE_FTELLO64)
45 return ftello64 (file);
46 #elif defined (HAVE_FTELLO)
54 real_fseek (FILE *file, file_ptr offset, int whence)
56 #if defined (HAVE_FSEEKO64)
57 return fseeko64 (file, offset, whence);
58 #elif defined (HAVE_FSEEKO)
59 return fseeko (file, offset, whence);
61 return fseek (file, offset, whence);
71 The <<struct bfd_iovec>> contains the internal file I/O class.
72 Each <<BFD>> has an instance of this class and all file I/O is
73 routed through it (it is assumed that the instance implements
74 all methods listed below).
78 . {* To avoid problems with macros, a "b" rather than "f"
79 . prefix is prepended to each method name. *}
80 . {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching
81 . bytes starting at PTR. Return the number of bytes actually
82 . transfered (a read past end-of-file returns less than NBYTES),
83 . or -1 (setting <<bfd_error>>) if an error occurs. *}
84 . file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes);
85 . file_ptr (*bwrite) (struct bfd *abfd, const void *ptr,
87 . {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>>
88 . if an error occurs. *}
89 . file_ptr (*btell) (struct bfd *abfd);
90 . {* For the following, on successful completion a value of 0 is returned.
91 . Otherwise, a value of -1 is returned (and <<bfd_error>> is set). *}
92 . int (*bseek) (struct bfd *abfd, file_ptr offset, int whence);
93 . int (*bclose) (struct bfd *abfd);
94 . int (*bflush) (struct bfd *abfd);
95 . int (*bstat) (struct bfd *abfd, struct stat *sb);
101 /* Return value is amount read. */
104 bfd_bread (void *ptr, bfd_size_type size, bfd *abfd)
108 if ((abfd->flags & BFD_IN_MEMORY) != 0)
110 struct bfd_in_memory *bim;
113 bim = abfd->iostream;
115 if (abfd->where + get > bim->size)
117 if (bim->size < (bfd_size_type) abfd->where)
120 get = bim->size - abfd->where;
121 bfd_set_error (bfd_error_file_truncated);
123 memcpy (ptr, bim->buffer + abfd->where, (size_t) get);
128 nread = abfd->iovec->bread (abfd, ptr, size);
129 if (nread != (size_t) -1)
130 abfd->where += nread;
136 bfd_bwrite (const void *ptr, bfd_size_type size, bfd *abfd)
140 if ((abfd->flags & BFD_IN_MEMORY) != 0)
142 struct bfd_in_memory *bim = abfd->iostream;
143 size = (size_t) size;
144 if (abfd->where + size > bim->size)
146 bfd_size_type newsize, oldsize;
148 oldsize = (bim->size + 127) & ~(bfd_size_type) 127;
149 bim->size = abfd->where + size;
150 /* Round up to cut down on memory fragmentation */
151 newsize = (bim->size + 127) & ~(bfd_size_type) 127;
152 if (newsize > oldsize)
154 bim->buffer = bfd_realloc (bim->buffer, newsize);
155 if (bim->buffer == 0)
162 memcpy (bim->buffer + abfd->where, ptr, (size_t) size);
167 nwrote = abfd->iovec->bwrite (abfd, ptr, size);
168 if (nwrote != (size_t) -1)
169 abfd->where += nwrote;
175 bfd_set_error (bfd_error_system_call);
185 if ((abfd->flags & BFD_IN_MEMORY) != 0)
188 ptr = abfd->iovec->btell (abfd);
190 if (abfd->my_archive)
197 bfd_flush (bfd *abfd)
199 if ((abfd->flags & BFD_IN_MEMORY) != 0)
201 return abfd->iovec->bflush (abfd);
204 /* Returns 0 for success, negative value for failure (in which case
205 bfd_get_error can retrieve the error code). */
207 bfd_stat (bfd *abfd, struct stat *statbuf)
211 if ((abfd->flags & BFD_IN_MEMORY) != 0)
214 result = abfd->iovec->bstat (abfd, statbuf);
216 bfd_set_error (bfd_error_system_call);
220 /* Returns 0 for success, nonzero for failure (in which case bfd_get_error
221 can retrieve the error code). */
224 bfd_seek (bfd *abfd, file_ptr position, int direction)
227 file_ptr file_position;
228 /* For the time being, a BFD may not seek to it's end. The problem
229 is that we don't easily have a way to recognize the end of an
230 element in an archive. */
232 BFD_ASSERT (direction == SEEK_SET || direction == SEEK_CUR);
234 if (direction == SEEK_CUR && position == 0)
237 if ((abfd->flags & BFD_IN_MEMORY) != 0)
239 struct bfd_in_memory *bim;
241 bim = abfd->iostream;
243 if (direction == SEEK_SET)
244 abfd->where = position;
246 abfd->where += position;
248 if (abfd->where > bim->size)
250 if ((abfd->direction == write_direction) ||
251 (abfd->direction == both_direction))
253 bfd_size_type newsize, oldsize;
254 oldsize = (bim->size + 127) & ~(bfd_size_type) 127;
255 bim->size = abfd->where;
256 /* Round up to cut down on memory fragmentation */
257 newsize = (bim->size + 127) & ~(bfd_size_type) 127;
258 if (newsize > oldsize)
260 bim->buffer = bfd_realloc (bim->buffer, newsize);
261 if (bim->buffer == 0)
270 abfd->where = bim->size;
271 bfd_set_error (bfd_error_file_truncated);
278 if (abfd->format != bfd_archive && abfd->my_archive == 0)
281 /* Explanation for this code: I'm only about 95+% sure that the above
282 conditions are sufficient and that all i/o calls are properly
283 adjusting the `where' field. So this is sort of an `assert'
284 that the `where' field is correct. If we can go a while without
285 tripping the abort, we can probably safely disable this code,
286 so that the real optimizations happen. */
287 file_ptr where_am_i_now;
288 where_am_i_now = real_ftell (bfd_cache_lookup (abfd));
289 if (abfd->my_archive)
290 where_am_i_now -= abfd->origin;
291 if (where_am_i_now != abfd->where)
294 if (direction == SEEK_SET && (bfd_vma) position == abfd->where)
299 /* We need something smarter to optimize access to archives.
300 Currently, anything inside an archive is read via the file
301 handle for the archive. Which means that a bfd_seek on one
302 component affects the `current position' in the archive, as
303 well as in any other component.
305 It might be sufficient to put a spike through the cache
306 abstraction, and look to the archive for the file position,
307 but I think we should try for something cleaner.
309 In the meantime, no optimization for archives. */
312 file_position = position;
313 if (direction == SEEK_SET && abfd->my_archive != NULL)
314 file_position += abfd->origin;
316 result = abfd->iovec->bseek (abfd, file_position, direction);
319 int hold_errno = errno;
321 /* Force redetermination of `where' field. */
324 /* An EINVAL error probably means that the file offset was
326 if (hold_errno == EINVAL)
327 bfd_set_error (bfd_error_file_truncated);
330 bfd_set_error (bfd_error_system_call);
336 /* Adjust `where' field. */
337 if (direction == SEEK_SET)
338 abfd->where = position;
340 abfd->where += position;
350 long bfd_get_mtime (bfd *abfd);
353 Return the file modification time (as read from the file system, or
354 from the archive header for archive members).
359 bfd_get_mtime (bfd *abfd)
366 if (abfd->iovec->bstat (abfd, &buf) != 0)
369 abfd->mtime = buf.st_mtime; /* Save value in case anyone wants it */
378 long bfd_get_size (bfd *abfd);
381 Return the file size (as read from file system) for the file
382 associated with BFD @var{abfd}.
384 The initial motivation for, and use of, this routine is not
385 so we can get the exact size of the object the BFD applies to, since
386 that might not be generally possible (archive members for example).
387 It would be ideal if someone could eventually modify
388 it so that such results were guaranteed.
390 Instead, we want to ask questions like "is this NNN byte sized
391 object I'm about to try read from file offset YYY reasonable?"
392 As as example of where we might do this, some object formats
393 use string tables for which the first <<sizeof (long)>> bytes of the
394 table contain the size of the table itself, including the size bytes.
395 If an application tries to read what it thinks is one of these
396 string tables, without some way to validate the size, and for
397 some reason the size is wrong (byte swapping error, wrong location
398 for the string table, etc.), the only clue is likely to be a read
399 error when it tries to read the table, or a "virtual memory
400 exhausted" error when it tries to allocate 15 bazillon bytes
401 of space for the 15 bazillon byte table it is about to read.
402 This function at least allows us to answer the question, "is the
407 bfd_get_size (bfd *abfd)
411 if ((abfd->flags & BFD_IN_MEMORY) != 0)
412 return ((struct bfd_in_memory *) abfd->iostream)->size;
414 if (abfd->iovec->bstat (abfd, &buf) != 0)