* libbfd.c (real_read): don't call fread for zero bytes. This
[deliverable/binutils-gdb.git] / bfd / binary.c
CommitLineData
c768bd3f 1/* BFD back-end for binary objects.
a96acce3 2 Copyright 1994, 95, 96, 97, 98, 1999 Free Software Foundation, Inc.
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3 Written by Ian Lance Taylor, Cygnus Support, <ian@cygnus.com>
4
5This file is part of BFD, the Binary File Descriptor library.
6
7This program is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 2 of the License, or
10(at your option) any later version.
11
12This program is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with this program; if not, write to the Free Software
a5655244 19Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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20
21/* This is a BFD backend which may be used to write binary objects.
22 It may only be used for output, not input. The intention is that
23 this may be used as an output format for objcopy in order to
24 generate raw binary data.
25
26 This is very simple. The only complication is that the real data
27 will start at some address X, and in some cases we will not want to
28 include X zeroes just to get to that point. Since the start
29 address is not meaningful for this object file format, we use it
30 instead to indicate the number of zeroes to skip at the start of
31 the file. objcopy cooperates by specially setting the start
32 address to zero by default. */
33
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34#include <ctype.h>
35
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36#include "bfd.h"
37#include "sysdep.h"
38#include "libbfd.h"
39
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40/* Any bfd we create by reading a binary file has three symbols:
41 a start symbol, an end symbol, and an absolute length symbol. */
42#define BIN_SYMS 3
43
c768bd3f 44static boolean binary_mkobject PARAMS ((bfd *));
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45static const bfd_target *binary_object_p PARAMS ((bfd *));
46static boolean binary_get_section_contents
47 PARAMS ((bfd *, asection *, PTR, file_ptr, bfd_size_type));
48static long binary_get_symtab_upper_bound PARAMS ((bfd *));
49static char *mangle_name PARAMS ((bfd *, char *));
50static long binary_get_symtab PARAMS ((bfd *, asymbol **));
c768bd3f 51static asymbol *binary_make_empty_symbol PARAMS ((bfd *));
a5655244 52static void binary_get_symbol_info PARAMS ((bfd *, asymbol *, symbol_info *));
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53static boolean binary_set_section_contents
54 PARAMS ((bfd *, asection *, PTR, file_ptr, bfd_size_type));
a5655244 55static int binary_sizeof_headers PARAMS ((bfd *, boolean));
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56
57/* Create a binary object. Invoked via bfd_set_format. */
58
59static boolean
60binary_mkobject (abfd)
61 bfd *abfd;
62{
63 return true;
64}
65
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66/* Any file may be considered to be a binary file, provided the target
67 was not defaulted. That is, it must be explicitly specified as
68 being binary. */
69
70static const bfd_target *
71binary_object_p (abfd)
72 bfd *abfd;
73{
74 struct stat statbuf;
75 asection *sec;
76
77 if (abfd->target_defaulted)
78 {
79 bfd_set_error (bfd_error_wrong_format);
80 return NULL;
81 }
82
83 abfd->symcount = BIN_SYMS;
84
85 /* Find the file size. */
86 if (bfd_stat (abfd, &statbuf) < 0)
87 {
88 bfd_set_error (bfd_error_system_call);
89 return NULL;
90 }
91
92 /* One data section. */
93 sec = bfd_make_section (abfd, ".data");
94 if (sec == NULL)
95 return NULL;
96 sec->flags = SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_HAS_CONTENTS;
97 sec->vma = 0;
98 sec->_raw_size = statbuf.st_size;
99 sec->filepos = 0;
100
101 abfd->tdata.any = (PTR) sec;
102
103 return abfd->xvec;
104}
105
106#define binary_close_and_cleanup _bfd_generic_close_and_cleanup
107#define binary_bfd_free_cached_info _bfd_generic_bfd_free_cached_info
108#define binary_new_section_hook _bfd_generic_new_section_hook
109
110/* Get contents of the only section. */
111
112static boolean
113binary_get_section_contents (abfd, section, location, offset, count)
114 bfd *abfd;
115 asection *section;
116 PTR location;
117 file_ptr offset;
118 bfd_size_type count;
119{
120 if (bfd_seek (abfd, offset, SEEK_SET) != 0
121 || bfd_read (location, 1, count, abfd) != count)
122 return false;
123 return true;
124}
125
126/* Return the amount of memory needed to read the symbol table. */
127
128static long
129binary_get_symtab_upper_bound (abfd)
130 bfd *abfd;
131{
132 return (BIN_SYMS + 1) * sizeof (asymbol *);
133}
134
135/* Create a symbol name based on the bfd's filename. */
136
137static char *
138mangle_name (abfd, suffix)
139 bfd *abfd;
140 char *suffix;
141{
142 int size;
143 char *buf;
144 char *p;
145
146 size = (strlen (bfd_get_filename (abfd))
147 + strlen (suffix)
148 + sizeof "_binary__");
149
150 buf = (char *) bfd_alloc (abfd, size);
151 if (buf == NULL)
a9713b91 152 return "";
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153
154 sprintf (buf, "_binary_%s_%s", bfd_get_filename (abfd), suffix);
155
156 /* Change any non-alphanumeric characters to underscores. */
157 for (p = buf; *p; p++)
223fff66 158 if (! isalnum ((unsigned char) *p))
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159 *p = '_';
160
161 return buf;
162}
c768bd3f 163
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164/* Return the symbol table. */
165
166static long
167binary_get_symtab (abfd, alocation)
168 bfd *abfd;
169 asymbol **alocation;
170{
171 asection *sec = (asection *) abfd->tdata.any;
172 asymbol *syms;
173 unsigned int i;
174
175 syms = (asymbol *) bfd_alloc (abfd, BIN_SYMS * sizeof (asymbol));
176 if (syms == NULL)
a9713b91 177 return false;
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178
179 /* Start symbol. */
180 syms[0].the_bfd = abfd;
181 syms[0].name = mangle_name (abfd, "start");
182 syms[0].value = 0;
183 syms[0].flags = BSF_GLOBAL;
184 syms[0].section = sec;
185 syms[0].udata.p = NULL;
186
187 /* End symbol. */
188 syms[1].the_bfd = abfd;
189 syms[1].name = mangle_name (abfd, "end");
190 syms[1].value = sec->_raw_size;
191 syms[1].flags = BSF_GLOBAL;
192 syms[1].section = sec;
193 syms[1].udata.p = NULL;
194
195 /* Size symbol. */
196 syms[2].the_bfd = abfd;
197 syms[2].name = mangle_name (abfd, "size");
198 syms[2].value = sec->_raw_size;
199 syms[2].flags = BSF_GLOBAL;
200 syms[2].section = bfd_abs_section_ptr;
201 syms[2].udata.p = NULL;
202
203 for (i = 0; i < BIN_SYMS; i++)
204 *alocation++ = syms++;
205 *alocation = NULL;
206
207 return BIN_SYMS;
208}
209
210/* Make an empty symbol. */
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211
212static asymbol *
213binary_make_empty_symbol (abfd)
214 bfd *abfd;
215{
a9713b91 216 return (asymbol *) bfd_alloc (abfd, sizeof (asymbol));
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217}
218
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219#define binary_print_symbol _bfd_nosymbols_print_symbol
220
221/* Get information about a symbol. */
222
223static void
224binary_get_symbol_info (ignore_abfd, symbol, ret)
225 bfd *ignore_abfd;
226 asymbol *symbol;
227 symbol_info *ret;
228{
229 bfd_symbol_info (symbol, ret);
230}
231
223fff66 232#define binary_bfd_is_local_label_name bfd_generic_is_local_label_name
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233#define binary_get_lineno _bfd_nosymbols_get_lineno
234#define binary_find_nearest_line _bfd_nosymbols_find_nearest_line
235#define binary_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol
236#define binary_read_minisymbols _bfd_generic_read_minisymbols
237#define binary_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol
238
239#define binary_get_reloc_upper_bound \
240 ((long (*) PARAMS ((bfd *, asection *))) bfd_0l)
241#define binary_canonicalize_reloc \
242 ((long (*) PARAMS ((bfd *, asection *, arelent **, asymbol **))) bfd_0l)
243#define binary_bfd_reloc_type_lookup _bfd_norelocs_bfd_reloc_type_lookup
244
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245/* Set the architecture of a binary file. */
246#define binary_set_arch_mach _bfd_generic_set_arch_mach
247
248/* Write section contents of a binary file. */
249
250static boolean
251binary_set_section_contents (abfd, sec, data, offset, size)
252 bfd *abfd;
253 asection *sec;
254 PTR data;
255 file_ptr offset;
256 bfd_size_type size;
257{
a5655244 258 if (! abfd->output_has_begun)
c768bd3f 259 {
223fff66 260 boolean found_low;
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261 bfd_vma low;
262 asection *s;
263
223fff66
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264 /* The lowest section LMA sets the virtual address of the start
265 of the file. We use this to set the file position of all the
a5655244 266 sections. */
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267 found_low = false;
268 low = 0;
269 for (s = abfd->sections; s != NULL; s = s->next)
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270 if (((s->flags
271 & (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC | SEC_NEVER_LOAD))
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272 == (SEC_HAS_CONTENTS | SEC_LOAD | SEC_ALLOC))
273 && (! found_low || s->lma < low))
274 {
275 low = s->lma;
276 found_low = true;
277 }
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278
279 for (s = abfd->sections; s != NULL; s = s->next)
223fff66
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280 {
281 s->filepos = s->lma - low;
282
283 /* If attempting to generate a binary file from a bfd with
284 LMA's all over the place, huge (sparse?) binary files may
285 result. This condition attempts to detect this situation
286 and print a warning. Better heuristics would be nice to
287 have. */
288
289 if (s->filepos < 0)
290 (*_bfd_error_handler)
291 (_("Warning: Writing section `%s' to huge offset %lu."),
292 bfd_get_section_name (abfd, s),
293 (unsigned long) s->filepos);
294 }
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295
296 abfd->output_has_begun = true;
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297 }
298
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299 /* We don't want to output anything for a section that is neither
300 loaded nor allocated. The contents of such a section are not
301 meaningful in the binary format. */
302 if ((sec->flags & (SEC_LOAD | SEC_ALLOC)) == 0)
303 return true;
304 if ((sec->flags & SEC_NEVER_LOAD) != 0)
305 return true;
306
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307 return _bfd_generic_set_section_contents (abfd, sec, data, offset, size);
308}
309
a5655244
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310/* No space is required for header information. */
311
312static int
313binary_sizeof_headers (abfd, exec)
314 bfd *abfd;
315 boolean exec;
316{
317 return 0;
318}
319
320#define binary_bfd_get_relocated_section_contents \
321 bfd_generic_get_relocated_section_contents
322#define binary_bfd_relax_section bfd_generic_relax_section
223fff66 323#define binary_bfd_gc_sections bfd_generic_gc_sections
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324#define binary_bfd_link_hash_table_create _bfd_generic_link_hash_table_create
325#define binary_bfd_link_add_symbols _bfd_generic_link_add_symbols
326#define binary_bfd_final_link _bfd_generic_final_link
327#define binary_bfd_link_split_section _bfd_generic_link_split_section
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328#define binary_get_section_contents_in_window \
329 _bfd_generic_get_section_contents_in_window
a5655244 330
c768bd3f
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331const bfd_target binary_vec =
332{
333 "binary", /* name */
334 bfd_target_unknown_flavour, /* flavour */
223fff66
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335 BFD_ENDIAN_UNKNOWN, /* byteorder */
336 BFD_ENDIAN_UNKNOWN, /* header_byteorder */
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337 EXEC_P, /* object_flags */
338 (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE | SEC_DATA
339 | SEC_ROM | SEC_HAS_CONTENTS), /* section_flags */
340 0, /* symbol_leading_char */
341 ' ', /* ar_pad_char */
342 16, /* ar_max_namelen */
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343 bfd_getb64, bfd_getb_signed_64, bfd_putb64,
344 bfd_getb32, bfd_getb_signed_32, bfd_putb32,
345 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* data */
346 bfd_getb64, bfd_getb_signed_64, bfd_putb64,
347 bfd_getb32, bfd_getb_signed_32, bfd_putb32,
348 bfd_getb16, bfd_getb_signed_16, bfd_putb16, /* hdrs */
349 { /* bfd_check_format */
350 _bfd_dummy_target,
a5655244 351 binary_object_p, /* bfd_check_format */
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352 _bfd_dummy_target,
353 _bfd_dummy_target,
354 },
355 { /* bfd_set_format */
356 bfd_false,
357 binary_mkobject,
358 bfd_false,
359 bfd_false,
360 },
361 { /* bfd_write_contents */
362 bfd_false,
363 bfd_true,
364 bfd_false,
365 bfd_false,
366 },
367
a5655244 368 BFD_JUMP_TABLE_GENERIC (binary),
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369 BFD_JUMP_TABLE_COPY (_bfd_generic),
370 BFD_JUMP_TABLE_CORE (_bfd_nocore),
371 BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
372 BFD_JUMP_TABLE_SYMBOLS (binary),
a5655244 373 BFD_JUMP_TABLE_RELOCS (binary),
c768bd3f 374 BFD_JUMP_TABLE_WRITE (binary),
a5655244 375 BFD_JUMP_TABLE_LINK (binary),
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376 BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
377
378 NULL
379};
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