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252b5132 RH |
1 | /* Generic BFD support for file formats. |
2 | Copyright (C) 1990, 91, 92, 93, 94, 95, 1999 Free Software Foundation, Inc. | |
3 | Written by Cygnus Support. | |
4 | ||
5 | This file is part of BFD, the Binary File Descriptor library. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program; if not, write to the Free Software | |
19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | /* | |
22 | SECTION | |
23 | File formats | |
24 | ||
25 | A format is a BFD concept of high level file contents type. The | |
26 | formats supported by BFD are: | |
27 | ||
28 | o <<bfd_object>> | |
29 | ||
30 | The BFD may contain data, symbols, relocations and debug info. | |
31 | ||
32 | o <<bfd_archive>> | |
33 | ||
34 | The BFD contains other BFDs and an optional index. | |
35 | ||
36 | o <<bfd_core>> | |
37 | ||
38 | The BFD contains the result of an executable core dump. | |
39 | ||
40 | ||
41 | */ | |
42 | ||
43 | #include "bfd.h" | |
44 | #include "sysdep.h" | |
45 | #include "libbfd.h" | |
46 | ||
47 | /* IMPORT from targets.c. */ | |
48 | extern const size_t _bfd_target_vector_entries; | |
49 | ||
50 | /* | |
51 | FUNCTION | |
52 | bfd_check_format | |
53 | ||
54 | SYNOPSIS | |
55 | boolean bfd_check_format(bfd *abfd, bfd_format format); | |
56 | ||
57 | DESCRIPTION | |
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>>). | |
61 | ||
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. | |
69 | ||
70 | The function returns <<true>> on success, otherwise <<false>> | |
71 | with one of the following error codes: | |
72 | ||
73 | o <<bfd_error_invalid_operation>> - | |
74 | if <<format>> is not one of <<bfd_object>>, <<bfd_archive>> or | |
75 | <<bfd_core>>. | |
76 | ||
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. | |
80 | ||
81 | o <<file_not_recognised>> - | |
82 | none of the backends recognised the file format. | |
83 | ||
84 | o <<bfd_error_file_ambiguously_recognized>> - | |
85 | more than one backend recognised the file format. | |
86 | */ | |
87 | ||
88 | boolean | |
89 | bfd_check_format (abfd, format) | |
90 | bfd *abfd; | |
91 | bfd_format format; | |
92 | { | |
93 | return bfd_check_format_matches (abfd, format, NULL); | |
94 | } | |
95 | ||
96 | /* | |
97 | FUNCTION | |
98 | bfd_check_format_matches | |
99 | ||
100 | SYNOPSIS | |
101 | boolean bfd_check_format_matches(bfd *abfd, bfd_format format, char ***matching); | |
102 | ||
103 | DESCRIPTION | |
104 | Like <<bfd_check_format>>, except when it returns false with | |
105 | <<bfd_errno>> set to <<bfd_error_file_ambiguously_recognized>>. In that | |
106 | case, if @var{matching} is not NULL, it will be filled in with | |
107 | a NULL-terminated list of the names of the formats that matched, | |
108 | allocated with <<malloc>>. | |
109 | Then the user may choose a format and try again. | |
110 | ||
111 | When done with the list that @var{matching} points to, the caller | |
112 | should free it. | |
113 | */ | |
114 | ||
115 | boolean | |
116 | bfd_check_format_matches (abfd, format, matching) | |
117 | bfd *abfd; | |
118 | bfd_format format; | |
119 | char ***matching; | |
120 | { | |
121 | extern const bfd_target binary_vec; | |
122 | const bfd_target * const *target, *save_targ, *right_targ; | |
123 | char **matching_vector = NULL; | |
124 | int match_count; | |
125 | ||
126 | if (!bfd_read_p (abfd) || | |
127 | ((int)(abfd->format) < (int)bfd_unknown) || | |
1d713d9e NC |
128 | ((int)(abfd->format) >= (int)bfd_type_end)) |
129 | { | |
130 | bfd_set_error (bfd_error_invalid_operation); | |
131 | return false; | |
132 | } | |
252b5132 RH |
133 | |
134 | if (abfd->format != bfd_unknown) | |
135 | return (abfd->format == format)? true: false; | |
136 | ||
252b5132 RH |
137 | /* Since the target type was defaulted, check them |
138 | all in the hope that one will be uniquely recognized. */ | |
252b5132 RH |
139 | save_targ = abfd->xvec; |
140 | match_count = 0; | |
1d713d9e | 141 | |
252b5132 RH |
142 | if (matching) |
143 | { | |
144 | matching_vector = | |
145 | (char **) bfd_malloc (sizeof (char *) * | |
146 | (_bfd_target_vector_entries + 1)); | |
147 | if (!matching_vector) | |
148 | return false; | |
149 | matching_vector[0] = NULL; | |
150 | *matching = matching_vector; | |
151 | } | |
1d713d9e | 152 | |
252b5132 RH |
153 | right_targ = 0; |
154 | ||
1d713d9e | 155 | /* Presume the answer is yes. */ |
252b5132 RH |
156 | abfd->format = format; |
157 | ||
158 | /* If the target type was explicitly specified, just check that target. */ | |
1d713d9e NC |
159 | if (!abfd->target_defaulted) |
160 | { | |
161 | if (bfd_seek (abfd, (file_ptr)0, SEEK_SET) != 0) /* rewind! */ | |
252b5132 | 162 | return false; |
1d713d9e NC |
163 | |
164 | right_targ = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd)); | |
165 | ||
166 | if (right_targ) | |
252b5132 | 167 | { |
1d713d9e NC |
168 | abfd->xvec = right_targ; /* Set the target as returned. */ |
169 | ||
170 | if (matching) | |
171 | free (matching_vector); | |
172 | ||
173 | return true; /* File position has moved, BTW. */ | |
252b5132 | 174 | } |
1d713d9e NC |
175 | |
176 | /* For a long time the code has dropped through to check all | |
177 | targets if the specified target was wrong. I don't know why, | |
178 | and I'm reluctant to change it. However, in the case of an | |
179 | archive, it can cause problems. If the specified target does | |
180 | not permit archives (e.g., the binary target), then we should | |
181 | not allow some other target to recognize it as an archive, but | |
182 | should instead allow the specified target to recognize it as an | |
183 | object. When I first made this change, it broke the PE target, | |
184 | because the specified pei-i386 target did not recognize the | |
185 | actual pe-i386 archive. Since there may be other problems of | |
186 | this sort, I changed this test to check only for the binary | |
187 | target. */ | |
188 | if (format == bfd_archive && save_targ == &binary_vec) | |
252b5132 | 189 | { |
1d713d9e NC |
190 | abfd->xvec = save_targ; |
191 | abfd->format = bfd_unknown; | |
192 | ||
193 | if (matching) | |
194 | free (matching_vector); | |
195 | ||
196 | bfd_set_error (bfd_error_file_not_recognized); | |
197 | ||
198 | return false; | |
199 | } | |
200 | } | |
201 | ||
202 | for (target = bfd_target_vector; *target != NULL; target++) | |
203 | { | |
204 | const bfd_target *temp; | |
205 | ||
206 | if (*target == &binary_vec) | |
207 | continue; | |
208 | ||
209 | abfd->xvec = *target; /* Change BFD's target temporarily */ | |
210 | ||
211 | if (bfd_seek (abfd, (file_ptr)0, SEEK_SET) != 0) | |
212 | return false; | |
213 | ||
214 | /* If _bfd_check_format neglects to set bfd_error, assume | |
215 | bfd_error_wrong_format. We didn't used to even pay any | |
216 | attention to bfd_error, so I suspect that some | |
217 | _bfd_check_format might have this problem. */ | |
218 | bfd_set_error (bfd_error_wrong_format); | |
219 | ||
220 | temp = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd)); | |
221 | ||
222 | if (temp) | |
223 | { /* This format checks out as ok! */ | |
224 | right_targ = temp; | |
225 | ||
252b5132 RH |
226 | if (matching) |
227 | { | |
1d713d9e NC |
228 | matching_vector[match_count] = temp->name; |
229 | matching_vector[match_count + 1] = NULL; | |
230 | } | |
231 | ||
232 | match_count++; | |
233 | ||
234 | /* If this is the default target, accept it, even if other | |
235 | targets might match. People who want those other targets | |
236 | have to set the GNUTARGET variable. */ | |
237 | if (temp == bfd_default_vector[0]) | |
238 | { | |
239 | if (matching) | |
240 | { | |
241 | matching_vector[0] = temp->name; | |
242 | matching_vector[1] = NULL; | |
243 | } | |
244 | match_count = 1; | |
245 | break; | |
252b5132 | 246 | } |
252b5132 | 247 | #ifdef GNU960 |
1d713d9e NC |
248 | /* Big- and little-endian b.out archives look the same, but it |
249 | doesn't matter: there is no difference in their headers, and | |
250 | member file byte orders will (I hope) be handled appropriately | |
251 | by bfd. Ditto for big and little coff archives. And the 4 | |
252 | coff/b.out object formats are unambiguous. So accept the | |
253 | first match we find. */ | |
254 | break; | |
252b5132 | 255 | #endif |
1d713d9e NC |
256 | } |
257 | else if (bfd_get_error () != bfd_error_wrong_format) | |
258 | { | |
259 | abfd->xvec = save_targ; | |
260 | abfd->format = bfd_unknown; | |
261 | ||
262 | if (matching && bfd_get_error () | |
263 | != bfd_error_file_ambiguously_recognized) | |
264 | free (matching_vector); | |
265 | ||
266 | return false; | |
267 | } | |
268 | } | |
269 | ||
270 | if (match_count == 1) | |
271 | { | |
272 | abfd->xvec = right_targ; /* Change BFD's target permanently. */ | |
273 | ||
274 | if (matching) | |
252b5132 | 275 | free (matching_vector); |
1d713d9e NC |
276 | |
277 | return true; /* File position has moved, BTW. */ | |
252b5132 | 278 | } |
252b5132 | 279 | |
1d713d9e NC |
280 | abfd->xvec = save_targ; /* Restore original target type. */ |
281 | abfd->format = bfd_unknown; /* Restore original format. */ | |
282 | ||
252b5132 RH |
283 | if (match_count == 0) |
284 | { | |
285 | bfd_set_error (bfd_error_file_not_recognized); | |
1d713d9e | 286 | |
252b5132 RH |
287 | if (matching) |
288 | free (matching_vector); | |
289 | } | |
290 | else | |
291 | bfd_set_error (bfd_error_file_ambiguously_recognized); | |
1d713d9e | 292 | |
252b5132 RH |
293 | return false; |
294 | } | |
295 | ||
296 | /* | |
297 | FUNCTION | |
298 | bfd_set_format | |
299 | ||
300 | SYNOPSIS | |
301 | boolean bfd_set_format(bfd *abfd, bfd_format format); | |
302 | ||
303 | DESCRIPTION | |
304 | This function sets the file format of the BFD @var{abfd} to the | |
305 | format @var{format}. If the target set in the BFD does not | |
306 | support the format requested, the format is invalid, or the BFD | |
307 | is not open for writing, then an error occurs. | |
252b5132 RH |
308 | */ |
309 | ||
310 | boolean | |
311 | bfd_set_format (abfd, format) | |
312 | bfd *abfd; | |
313 | bfd_format format; | |
314 | { | |
252b5132 RH |
315 | if (bfd_read_p (abfd) || |
316 | ((int)abfd->format < (int)bfd_unknown) || | |
1d713d9e NC |
317 | ((int)abfd->format >= (int)bfd_type_end)) |
318 | { | |
319 | bfd_set_error (bfd_error_invalid_operation); | |
320 | return false; | |
321 | } | |
252b5132 RH |
322 | |
323 | if (abfd->format != bfd_unknown) | |
1d713d9e | 324 | return (abfd->format == format) ? true : false; |
252b5132 | 325 | |
1d713d9e | 326 | /* Presume the answer is yes. */ |
252b5132 RH |
327 | abfd->format = format; |
328 | ||
1d713d9e NC |
329 | if (!BFD_SEND_FMT (abfd, _bfd_set_format, (abfd))) |
330 | { | |
331 | abfd->format = bfd_unknown; | |
332 | return false; | |
333 | } | |
252b5132 RH |
334 | |
335 | return true; | |
336 | } | |
337 | ||
338 | ||
339 | /* | |
340 | FUNCTION | |
341 | bfd_format_string | |
342 | ||
343 | SYNOPSIS | |
344 | CONST char *bfd_format_string(bfd_format format); | |
345 | ||
346 | DESCRIPTION | |
347 | Return a pointer to a const string | |
348 | <<invalid>>, <<object>>, <<archive>>, <<core>>, or <<unknown>>, | |
349 | depending upon the value of @var{format}. | |
350 | */ | |
351 | ||
352 | CONST char * | |
353 | bfd_format_string (format) | |
354 | bfd_format format; | |
355 | { | |
356 | if (((int)format <(int) bfd_unknown) | |
357 | || ((int)format >=(int) bfd_type_end)) | |
358 | return "invalid"; | |
359 | ||
1d713d9e NC |
360 | switch (format) |
361 | { | |
362 | case bfd_object: | |
363 | return "object"; /* Linker/assember/compiler output. */ | |
364 | case bfd_archive: | |
365 | return "archive"; /* Object archive file. */ | |
366 | case bfd_core: | |
367 | return "core"; /* Core dump. */ | |
368 | default: | |
369 | return "unknown"; | |
370 | } | |
252b5132 | 371 | } |