1 /* Generic BFD support for file formats.
2 Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1999, 2000, 2001, 2002, 2003
3 Free Software Foundation, Inc.
4 Written by Cygnus Support.
6 This file is part of BFD, the Binary File Descriptor library.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
26 A format is a BFD concept of high level file contents type. The
27 formats supported by BFD are:
31 The BFD may contain data, symbols, relocations and debug info.
35 The BFD contains other BFDs and an optional index.
39 The BFD contains the result of an executable core dump.
47 /* IMPORT from targets.c. */
48 extern const size_t _bfd_target_vector_entries
;
55 bfd_boolean bfd_check_format (bfd *abfd, bfd_format format);
58 Verify if the file attached to the BFD @var{abfd} is compatible
59 with the format @var{format} (i.e., one of <<bfd_object>>,
60 <<bfd_archive>> or <<bfd_core>>).
62 If the BFD has been set to a specific target before the
63 call, only the named target and format combination is
64 checked. If the target has not been set, or has been set to
65 <<default>>, then all the known target backends is
66 interrogated to determine a match. If the default target
67 matches, it is used. If not, exactly one target must recognize
68 the file, or an error results.
70 The function returns <<TRUE>> on success, otherwise <<FALSE>>
71 with one of the following error codes:
73 o <<bfd_error_invalid_operation>> -
74 if <<format>> is not one of <<bfd_object>>, <<bfd_archive>> or
77 o <<bfd_error_system_call>> -
78 if an error occured during a read - even some file mismatches
79 can cause bfd_error_system_calls.
81 o <<file_not_recognised>> -
82 none of the backends recognised the file format.
84 o <<bfd_error_file_ambiguously_recognized>> -
85 more than one backend recognised the file format.
89 bfd_check_format (abfd
, format
)
93 return bfd_check_format_matches (abfd
, format
, NULL
);
98 bfd_check_format_matches
101 bfd_boolean bfd_check_format_matches (bfd *abfd, bfd_format format,
105 Like <<bfd_check_format>>, except when it returns FALSE with
106 <<bfd_errno>> set to <<bfd_error_file_ambiguously_recognized>>. In that
107 case, if @var{matching} is not NULL, it will be filled in with
108 a NULL-terminated list of the names of the formats that matched,
109 allocated with <<malloc>>.
110 Then the user may choose a format and try again.
112 When done with the list that @var{matching} points to, the caller
117 bfd_check_format_matches (abfd
, format
, matching
)
122 extern const bfd_target binary_vec
;
123 const bfd_target
* const *target
;
124 const bfd_target
**matching_vector
= NULL
;
125 const bfd_target
*save_targ
, *right_targ
, *ar_right_targ
;
129 if (!bfd_read_p (abfd
)
130 || (unsigned int) abfd
->format
>= (unsigned int) bfd_type_end
)
132 bfd_set_error (bfd_error_invalid_operation
);
136 if (abfd
->format
!= bfd_unknown
)
137 return abfd
->format
== format
;
139 /* Since the target type was defaulted, check them
140 all in the hope that one will be uniquely recognized. */
141 save_targ
= abfd
->xvec
;
143 ar_match_index
= _bfd_target_vector_entries
;
150 amt
= sizeof (*matching_vector
) * 2 * _bfd_target_vector_entries
;
151 matching_vector
= (const bfd_target
**) bfd_malloc (amt
);
152 if (!matching_vector
)
159 /* Presume the answer is yes. */
160 abfd
->format
= format
;
162 /* If the target type was explicitly specified, just check that target. */
163 if (!abfd
->target_defaulted
)
165 if (bfd_seek (abfd
, (file_ptr
) 0, SEEK_SET
) != 0) /* rewind! */
168 right_targ
= BFD_SEND_FMT (abfd
, _bfd_check_format
, (abfd
));
172 abfd
->xvec
= right_targ
; /* Set the target as returned. */
175 free ((PTR
) matching_vector
);
177 return TRUE
; /* File position has moved, BTW. */
180 /* For a long time the code has dropped through to check all
181 targets if the specified target was wrong. I don't know why,
182 and I'm reluctant to change it. However, in the case of an
183 archive, it can cause problems. If the specified target does
184 not permit archives (e.g., the binary target), then we should
185 not allow some other target to recognize it as an archive, but
186 should instead allow the specified target to recognize it as an
187 object. When I first made this change, it broke the PE target,
188 because the specified pei-i386 target did not recognize the
189 actual pe-i386 archive. Since there may be other problems of
190 this sort, I changed this test to check only for the binary
192 if (format
== bfd_archive
&& save_targ
== &binary_vec
)
194 abfd
->xvec
= save_targ
;
195 abfd
->format
= bfd_unknown
;
198 free ((PTR
) matching_vector
);
200 bfd_set_error (bfd_error_file_not_recognized
);
206 for (target
= bfd_target_vector
; *target
!= NULL
; target
++)
208 const bfd_target
*temp
;
211 if (*target
== &binary_vec
)
214 abfd
->xvec
= *target
; /* Change BFD's target temporarily. */
216 if (bfd_seek (abfd
, (file_ptr
) 0, SEEK_SET
) != 0)
219 /* If _bfd_check_format neglects to set bfd_error, assume
220 bfd_error_wrong_format. We didn't used to even pay any
221 attention to bfd_error, so I suspect that some
222 _bfd_check_format might have this problem. */
223 bfd_set_error (bfd_error_wrong_format
);
225 temp
= BFD_SEND_FMT (abfd
, _bfd_check_format
, (abfd
));
229 /* This format checks out as ok! */
232 /* If this is the default target, accept it, even if other
233 targets might match. People who want those other targets
234 have to set the GNUTARGET variable. */
235 if (temp
== bfd_default_vector
[0])
242 matching_vector
[match_count
] = temp
;
247 /* Big- and little-endian b.out archives look the same, but it
248 doesn't matter: there is no difference in their headers, and
249 member file byte orders will (I hope) be handled appropriately
250 by bfd. Ditto for big and little coff archives. And the 4
251 coff/b.out object formats are unambiguous. So accept the
252 first match we find. */
256 else if ((err
= bfd_get_error ()) == bfd_error_wrong_object_format
257 || err
== bfd_error_file_ambiguously_recognized
)
259 /* An archive with objects of the wrong type, or an
260 ambiguous match. We want this target to match if we get
261 no better matches. */
262 if (ar_right_targ
!= bfd_default_vector
[0])
263 ar_right_targ
= *target
;
265 matching_vector
[ar_match_index
] = *target
;
268 else if (err
!= bfd_error_wrong_format
)
270 abfd
->xvec
= save_targ
;
271 abfd
->format
= bfd_unknown
;
274 free ((PTR
) matching_vector
);
280 if (match_count
== 0)
282 /* Try partial matches. */
283 right_targ
= ar_right_targ
;
285 if (right_targ
== bfd_default_vector
[0])
291 match_count
= ar_match_index
- _bfd_target_vector_entries
;
293 if (matching
&& match_count
> 1)
294 memcpy (matching_vector
,
295 matching_vector
+ _bfd_target_vector_entries
,
296 sizeof (*matching_vector
) * match_count
);
300 if (match_count
> 1 && bfd_associated_vector
!= NULL
)
302 const bfd_target
* const *assoc
= bfd_associated_vector
;
304 while ((right_targ
= *assoc
++) != NULL
)
309 if (matching_vector
[i
] == right_targ
)
320 if (match_count
== 1)
322 abfd
->xvec
= right_targ
; /* Change BFD's target permanently. */
325 free ((PTR
) matching_vector
);
327 return TRUE
; /* File position has moved, BTW. */
330 abfd
->xvec
= save_targ
; /* Restore original target type. */
331 abfd
->format
= bfd_unknown
; /* Restore original format. */
333 if (match_count
== 0)
335 bfd_set_error (bfd_error_file_not_recognized
);
338 free ((PTR
) matching_vector
);
342 bfd_set_error (bfd_error_file_ambiguously_recognized
);
346 *matching
= (char **) matching_vector
;
347 matching_vector
[match_count
] = NULL
;
348 /* Return target names. This is a little nasty. Maybe we
349 should do another bfd_malloc? */
350 while (--match_count
>= 0)
352 const char *name
= matching_vector
[match_count
]->name
;
353 *(const char **) &matching_vector
[match_count
] = name
;
366 bfd_boolean bfd_set_format (bfd *abfd, bfd_format format);
369 This function sets the file format of the BFD @var{abfd} to the
370 format @var{format}. If the target set in the BFD does not
371 support the format requested, the format is invalid, or the BFD
372 is not open for writing, then an error occurs.
376 bfd_set_format (abfd
, format
)
380 if (bfd_read_p (abfd
)
381 || (unsigned int) abfd
->format
>= (unsigned int) bfd_type_end
)
383 bfd_set_error (bfd_error_invalid_operation
);
387 if (abfd
->format
!= bfd_unknown
)
388 return abfd
->format
== format
;
390 /* Presume the answer is yes. */
391 abfd
->format
= format
;
393 if (!BFD_SEND_FMT (abfd
, _bfd_set_format
, (abfd
)))
395 abfd
->format
= bfd_unknown
;
407 const char *bfd_format_string (bfd_format format);
410 Return a pointer to a const string
411 <<invalid>>, <<object>>, <<archive>>, <<core>>, or <<unknown>>,
412 depending upon the value of @var{format}.
416 bfd_format_string (format
)
419 if (((int)format
<(int) bfd_unknown
)
420 || ((int)format
>=(int) bfd_type_end
))
426 return "object"; /* Linker/assember/compiler output. */
428 return "archive"; /* Object archive file. */
430 return "core"; /* Core dump. */