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
);
129 nread
= abfd
->iovec
->bread (abfd
, ptr
, size
);
132 if (nread
!= (size_t) -1)
133 abfd
->where
+= nread
;
139 bfd_bwrite (const void *ptr
, bfd_size_type size
, bfd
*abfd
)
143 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
145 struct bfd_in_memory
*bim
= abfd
->iostream
;
147 size
= (size_t) size
;
148 if (abfd
->where
+ size
> bim
->size
)
150 bfd_size_type newsize
, oldsize
;
152 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
153 bim
->size
= abfd
->where
+ size
;
154 /* Round up to cut down on memory fragmentation */
155 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
156 if (newsize
> oldsize
)
158 bim
->buffer
= bfd_realloc (bim
->buffer
, newsize
);
159 if (bim
->buffer
== 0)
166 memcpy (bim
->buffer
+ abfd
->where
, ptr
, (size_t) size
);
172 nwrote
= abfd
->iovec
->bwrite (abfd
, ptr
, size
);
176 if (nwrote
!= (size_t) -1)
177 abfd
->where
+= nwrote
;
183 bfd_set_error (bfd_error_system_call
);
193 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
198 ptr
= abfd
->iovec
->btell (abfd
);
200 if (abfd
->my_archive
)
211 bfd_flush (bfd
*abfd
)
213 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
217 return abfd
->iovec
->bflush (abfd
);
221 /* Returns 0 for success, negative value for failure (in which case
222 bfd_get_error can retrieve the error code). */
224 bfd_stat (bfd
*abfd
, struct stat
*statbuf
)
228 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
232 result
= abfd
->iovec
->bstat (abfd
, statbuf
);
237 bfd_set_error (bfd_error_system_call
);
241 /* Returns 0 for success, nonzero for failure (in which case bfd_get_error
242 can retrieve the error code). */
245 bfd_seek (bfd
*abfd
, file_ptr position
, int direction
)
248 file_ptr file_position
;
249 /* For the time being, a BFD may not seek to it's end. The problem
250 is that we don't easily have a way to recognize the end of an
251 element in an archive. */
253 BFD_ASSERT (direction
== SEEK_SET
|| direction
== SEEK_CUR
);
255 if (direction
== SEEK_CUR
&& position
== 0)
258 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
260 struct bfd_in_memory
*bim
;
262 bim
= abfd
->iostream
;
264 if (direction
== SEEK_SET
)
265 abfd
->where
= position
;
267 abfd
->where
+= position
;
269 if (abfd
->where
> bim
->size
)
271 if ((abfd
->direction
== write_direction
) ||
272 (abfd
->direction
== both_direction
))
274 bfd_size_type newsize
, oldsize
;
276 oldsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
277 bim
->size
= abfd
->where
;
278 /* Round up to cut down on memory fragmentation */
279 newsize
= (bim
->size
+ 127) & ~(bfd_size_type
) 127;
280 if (newsize
> oldsize
)
282 bim
->buffer
= bfd_realloc (bim
->buffer
, newsize
);
283 if (bim
->buffer
== 0)
292 abfd
->where
= bim
->size
;
293 bfd_set_error (bfd_error_file_truncated
);
300 if (abfd
->format
!= bfd_archive
&& abfd
->my_archive
== 0)
302 if (direction
== SEEK_SET
&& (bfd_vma
) position
== abfd
->where
)
307 /* We need something smarter to optimize access to archives.
308 Currently, anything inside an archive is read via the file
309 handle for the archive. Which means that a bfd_seek on one
310 component affects the `current position' in the archive, as
311 well as in any other component.
313 It might be sufficient to put a spike through the cache
314 abstraction, and look to the archive for the file position,
315 but I think we should try for something cleaner.
317 In the meantime, no optimization for archives. */
320 file_position
= position
;
321 if (direction
== SEEK_SET
&& abfd
->my_archive
!= NULL
)
322 file_position
+= abfd
->origin
;
325 result
= abfd
->iovec
->bseek (abfd
, file_position
, direction
);
331 int hold_errno
= errno
;
333 /* Force redetermination of `where' field. */
336 /* An EINVAL error probably means that the file offset was
338 if (hold_errno
== EINVAL
)
339 bfd_set_error (bfd_error_file_truncated
);
342 bfd_set_error (bfd_error_system_call
);
348 /* Adjust `where' field. */
349 if (direction
== SEEK_SET
)
350 abfd
->where
= position
;
352 abfd
->where
+= position
;
362 long bfd_get_mtime (bfd *abfd);
365 Return the file modification time (as read from the file system, or
366 from the archive header for archive members).
371 bfd_get_mtime (bfd
*abfd
)
378 if (abfd
->iovec
== NULL
)
381 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
384 abfd
->mtime
= buf
.st_mtime
; /* Save value in case anyone wants it */
393 long bfd_get_size (bfd *abfd);
396 Return the file size (as read from file system) for the file
397 associated with BFD @var{abfd}.
399 The initial motivation for, and use of, this routine is not
400 so we can get the exact size of the object the BFD applies to, since
401 that might not be generally possible (archive members for example).
402 It would be ideal if someone could eventually modify
403 it so that such results were guaranteed.
405 Instead, we want to ask questions like "is this NNN byte sized
406 object I'm about to try read from file offset YYY reasonable?"
407 As as example of where we might do this, some object formats
408 use string tables for which the first <<sizeof (long)>> bytes of the
409 table contain the size of the table itself, including the size bytes.
410 If an application tries to read what it thinks is one of these
411 string tables, without some way to validate the size, and for
412 some reason the size is wrong (byte swapping error, wrong location
413 for the string table, etc.), the only clue is likely to be a read
414 error when it tries to read the table, or a "virtual memory
415 exhausted" error when it tries to allocate 15 bazillon bytes
416 of space for the 15 bazillon byte table it is about to read.
417 This function at least allows us to answer the question, "is the
422 bfd_get_size (bfd
*abfd
)
426 if ((abfd
->flags
& BFD_IN_MEMORY
) != 0)
427 return ((struct bfd_in_memory
*) abfd
->iostream
)->size
;
429 if (abfd
->iovec
== NULL
)
432 if (abfd
->iovec
->bstat (abfd
, &buf
) != 0)
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