1 /* Generic BFD support for file formats.
2 Copyright (C) 1990-1991 Free Software Foundation, Inc.
3 Written by Cygnus Support.
5 This file is part of BFD, the Binary File Descriptor library.
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.
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.
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., 675 Mass Ave, Cambridge, MA 02139, USA. */
25 A format is a BFD concept of high level file contents type. The
26 formats supported by BFD are:
30 The BFD may contain data, symbols, relocations and debug info.
34 The BFD contains other BFDs and an optional index.
38 The BFD contains the result of an executable core dump.
47 extern bfd_target
*target_vector
[];
48 extern bfd_target
*default_vector
[];
56 boolean bfd_check_format(bfd *abfd, bfd_format format);
59 Verify if the file attached to the BFD @var{abfd} is compatible
60 with the format @var{format} (i.e., one of <<bfd_object>>,
61 <<bfd_archive>> or <<bfd_core>>).
63 If the BFD has been set to a specific target before the
64 call, only the named target and format combination is
65 checked. If the target has not been set, or has been set to
66 <<default>>, then all the known target backends is
67 interrogated to determine a match. If the default target
68 matches, it is used. If not, exactly one target must recognize
69 the file, or an error results.
71 The function returns <<true>> on success, otherwise <<false>>
72 with one of the following error codes:
75 if <<format>> is not one of <<bfd_object>>, <<bfd_archive>> or
79 if an error occured during a read - even some file mismatches
80 can cause system_call_errors.
82 o file_not_recognised -
83 none of the backends recognised the file format.
85 o file_ambiguously_recognized -
86 more than one backend recognised the file format.
91 DEFUN(bfd_check_format
,(abfd
, format
),
95 bfd_target
**target
, *save_targ
, *right_targ
;
98 if (!bfd_read_p (abfd
) ||
99 ((int)(abfd
->format
) < (int)bfd_unknown
) ||
100 ((int)(abfd
->format
) >= (int)bfd_type_end
)) {
101 bfd_error
= invalid_operation
;
105 if (abfd
->format
!= bfd_unknown
)
106 return (abfd
->format
== format
)? true: false;
109 /* Since the target type was defaulted, check them
110 all in the hope that one will be uniquely recognized. */
112 save_targ
= abfd
->xvec
;
117 /* presume the answer is yes */
118 abfd
->format
= format
;
120 /* If the target type was explicitly specified, just check that target. */
122 if (!abfd
->target_defaulted
) {
123 bfd_seek (abfd
, (file_ptr
)0, SEEK_SET
); /* rewind! */
125 right_targ
= BFD_SEND_FMT (abfd
, _bfd_check_format
, (abfd
));
127 abfd
->xvec
= right_targ
; /* Set the target as returned */
128 return true; /* File position has moved, BTW */
132 for (target
= target_vector
; *target
!= NULL
; target
++) {
135 abfd
->xvec
= *target
; /* Change BFD's target temporarily */
136 bfd_seek (abfd
, (file_ptr
)0, SEEK_SET
);
137 /* If _bfd_check_format neglects to set bfd_error, assume wrong_format.
138 We didn't used to even pay any attention to bfd_error, so I suspect
139 that some _bfd_check_format might have this problem. */
140 bfd_error
= wrong_format
;
141 temp
= BFD_SEND_FMT (abfd
, _bfd_check_format
, (abfd
));
142 if (temp
) { /* This format checks out as ok! */
145 /* If this is the default target, accept it, even if other targets
146 might match. People who want those other targets have to set
147 the GNUTARGET variable. */
148 if (temp
== default_vector
[0])
154 /* Big- and little-endian b.out archives look the same, but it doesn't
155 * matter: there is no difference in their headers, and member file byte
156 * orders will (I hope) be handled appropriately by bfd. Ditto for big
157 * and little coff archives. And the 4 coff/b.out object formats are
158 * unambiguous. So accept the first match we find.
162 } else if (bfd_error
!= wrong_format
) {
163 abfd
->xvec
= save_targ
;
164 abfd
->format
= bfd_unknown
;
169 if (match_count
== 1) {
170 abfd
->xvec
= right_targ
; /* Change BFD's target permanently */
171 return true; /* File position has moved, BTW */
174 abfd
->xvec
= save_targ
; /* Restore original target type */
175 abfd
->format
= bfd_unknown
; /* Restore original format */
176 bfd_error
= ((match_count
== 0) ? file_not_recognized
:
177 file_ambiguously_recognized
);
187 boolean bfd_set_format(bfd *abfd, bfd_format format);
190 This function sets the file format of the BFD @var{abfd} to the
191 format @var{format}. If the target set in the BFD does not
192 support the format requested, the format is invalid, or the BFD
193 is not open for writing, then an error occurs.
198 DEFUN(bfd_set_format
,(abfd
, format
),
203 if (bfd_read_p (abfd
) ||
204 ((int)abfd
->format
< (int)bfd_unknown
) ||
205 ((int)abfd
->format
>= (int)bfd_type_end
)) {
206 bfd_error
= invalid_operation
;
210 if (abfd
->format
!= bfd_unknown
)
211 return (abfd
->format
== format
) ? true:false;
213 /* presume the answer is yes */
214 abfd
->format
= format
;
216 if (!BFD_SEND_FMT (abfd
, _bfd_set_format
, (abfd
))) {
217 abfd
->format
= bfd_unknown
;
230 CONST char *bfd_format_string(bfd_format format);
233 Return a pointer to a const string
234 <<invalid>>, <<object>>, <<archive>>, <<core>>, or <<unknown>>,
235 depending upon the value of @var{format}.
239 DEFUN(bfd_format_string
,(format
),
242 if (((int)format
<(int) bfd_unknown
)
243 || ((int)format
>=(int) bfd_type_end
))
248 return "object"; /* linker/assember/compiler output */
250 return "archive"; /* object archive file */
252 return "core"; /* core dump */