aboutsummaryrefslogtreecommitdiff
path: root/bfd/libbfd.c
blob: 6a9d4660ad95c81555c7fa0d2e2d2eb00bc59ff9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
/* Assorted BFD support routines, only used internally.
   Copyright 1990, 91, 92, 93, 94, 95, 96, 97, 98, 1999
   Free Software Foundation, Inc.
   Written by Cygnus Support.

This file is part of BFD, the Binary File Descriptor library.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#include "bfd.h"
#include "sysdep.h"
#include "libbfd.h"

#ifndef HAVE_GETPAGESIZE
#define getpagesize() 2048
#endif

static int real_read PARAMS ((PTR, size_t, size_t, FILE *));

/*
SECTION
	Internal functions

DESCRIPTION
	These routines are used within BFD.
	They are not intended for export, but are documented here for
	completeness.
*/

/* A routine which is used in target vectors for unsupported
   operations.  */

boolean
bfd_false (ignore)
     bfd *ignore ATTRIBUTE_UNUSED;
{
  bfd_set_error (bfd_error_invalid_operation);
  return false;
}

/* A routine which is used in target vectors for supported operations
   which do not actually do anything.  */

boolean
bfd_true (ignore)
     bfd *ignore ATTRIBUTE_UNUSED;
{
  return true;
}

/* A routine which is used in target vectors for unsupported
   operations which return a pointer value.  */

PTR
bfd_nullvoidptr (ignore)
     bfd *ignore ATTRIBUTE_UNUSED;
{
  bfd_set_error (bfd_error_invalid_operation);
  return NULL;
}

int
bfd_0 (ignore)
     bfd *ignore ATTRIBUTE_UNUSED;
{
  return 0;
}

unsigned int
bfd_0u (ignore)
     bfd *ignore ATTRIBUTE_UNUSED;
{
   return 0;
}

long
bfd_0l (ignore)
     bfd *ignore ATTRIBUTE_UNUSED;
{
  return 0;
}

/* A routine which is used in target vectors for unsupported
   operations which return -1 on error.  */

long
_bfd_n1 (ignore_abfd)
     bfd *ignore_abfd ATTRIBUTE_UNUSED;
{
  bfd_set_error (bfd_error_invalid_operation);
  return -1;
}

void
bfd_void (ignore)
     bfd *ignore ATTRIBUTE_UNUSED;
{
}

boolean
_bfd_nocore_core_file_matches_executable_p (ignore_core_bfd, ignore_exec_bfd)
     bfd *ignore_core_bfd ATTRIBUTE_UNUSED;
     bfd *ignore_exec_bfd ATTRIBUTE_UNUSED;
{
  bfd_set_error (bfd_error_invalid_operation);
  return false;
}

/* Routine to handle core_file_failing_command entry point for targets
   without core file support.  */

char *
_bfd_nocore_core_file_failing_command (ignore_abfd)
     bfd *ignore_abfd ATTRIBUTE_UNUSED;
{
  bfd_set_error (bfd_error_invalid_operation);
  return (char *)NULL;
}

/* Routine to handle core_file_failing_signal entry point for targets
   without core file support.  */

int
_bfd_nocore_core_file_failing_signal (ignore_abfd)
     bfd *ignore_abfd ATTRIBUTE_UNUSED;
{
  bfd_set_error (bfd_error_invalid_operation);
  return 0;
}

const bfd_target *
_bfd_dummy_target (ignore_abfd)
     bfd *ignore_abfd ATTRIBUTE_UNUSED;
{
  bfd_set_error (bfd_error_wrong_format);
  return 0;
}

/* Allocate memory using malloc.  */

PTR
bfd_malloc (size)
     size_t size;
{
  PTR ptr;

  ptr = (PTR) malloc (size);
  if (ptr == NULL && size != 0)
    bfd_set_error (bfd_error_no_memory);
  return ptr;
}

/* Reallocate memory using realloc.  */

PTR
bfd_realloc (ptr, size)
     PTR ptr;
     size_t size;
{
  PTR ret;

  if (ptr == NULL)
    ret = malloc (size);
  else
    ret = realloc (ptr, size);

  if (ret == NULL)
    bfd_set_error (bfd_error_no_memory);

  return ret;
}

/* Allocate memory using malloc and clear it.  */

PTR
bfd_zmalloc (size)
     size_t size;
{
  PTR ptr;

  ptr = (PTR) malloc (size);

  if (size != 0)
    {
      if (ptr == NULL)
	bfd_set_error (bfd_error_no_memory);
      else
	memset (ptr, 0, size);
    }

  return ptr;
}

/* Some IO code */

/* Note that archive entries don't have streams; they share their parent's.
   This allows someone to play with the iostream behind BFD's back.

   Also, note that the origin pointer points to the beginning of a file's
   contents (0 for non-archive elements).  For archive entries this is the
   first octet in the file, NOT the beginning of the archive header.  */

static int
real_read (where, a,b, file)
     PTR where;
     size_t a;
     size_t b;
     FILE *file;
{
  /* FIXME - this looks like an optimization, but it's really to cover
     up for a feature of some OSs (not solaris - sigh) that
     ld/pe-dll.c takes advantage of (apparently) when it creates BFDs
     internally and tries to link against them.  BFD seems to be smart
     enough to realize there are no symbol records in the "file" that
     doesn't exist but attempts to read them anyway.  On Solaris,
     attempting to read zero bytes from a NULL file results in a core
     dump, but on other platforms it just returns zero bytes read.
     This makes it to something reasonable. - DJ */
  if (a == 0 || b == 0)
    return 0;

#if defined (__VAX) && defined (VMS)
  /* Apparently fread on Vax VMS does not keep the record length
     information.  */
  return read (fileno (file), where, a * b);
#else
  return fread (where, a, b, file);
#endif
}

/* Return value is amount read (FIXME: how are errors and end of file dealt
   with?  We never call bfd_set_error, which is probably a mistake).  */

bfd_size_type
bfd_read (ptr, size, nitems, abfd)
     PTR ptr;
     bfd_size_type size;
     bfd_size_type nitems;
     bfd *abfd;
{
  int nread;

  if ((abfd->flags & BFD_IN_MEMORY) != 0)
    {
      struct bfd_in_memory *bim;
      bfd_size_type get;

      bim = (struct bfd_in_memory *) abfd->iostream;
      get = size * nitems;
      if (abfd->where + get > bim->size)
	{
	  if (bim->size < (bfd_size_type) abfd->where)
	    get = 0;
	  else
	    get = bim->size - abfd->where;
	  bfd_set_error (bfd_error_file_truncated);
	}
      memcpy (ptr, bim->buffer + abfd->where, get);
      abfd->where += get;
      return get;
    }

  nread = real_read (ptr, 1, (size_t) (size*nitems), bfd_cache_lookup(abfd));
  if (nread > 0)
    abfd->where += nread;

  /* Set bfd_error if we did not read as much data as we expected.

     If the read failed due to an error set the bfd_error_system_call,
     else set bfd_error_file_truncated.

     A BFD backend may wish to override bfd_error_file_truncated to
     provide something more useful (eg. no_symbols or wrong_format).  */
  if (nread != (int) (size * nitems))
    {
      if (ferror (bfd_cache_lookup (abfd)))
	bfd_set_error (bfd_error_system_call);
      else
	bfd_set_error (bfd_error_file_truncated);
    }

  return nread;
}

/* The window support stuff should probably be broken out into
   another file....  */
/* The idea behind the next and refcount fields is that one mapped
   region can suffice for multiple read-only windows or multiple
   non-overlapping read-write windows.  It's not implemented yet
   though.  */
struct _bfd_window_internal {
  struct _bfd_window_internal *next;
  PTR data;
  bfd_size_type size;
  int refcount : 31;		/* should be enough...  */
  unsigned mapped : 1;		/* 1 = mmap, 0 = malloc */
};

void
bfd_init_window (windowp)
     bfd_window *windowp;
{
  windowp->data = 0;
  windowp->i = 0;
  windowp->size = 0;
}

/* Currently, if USE_MMAP is undefined, none if the window stuff is
   used.  Okay, so it's mis-named.  At least the command-line option
   "--without-mmap" is more obvious than "--without-windows" or some
   such.  */
#ifdef USE_MMAP

#undef HAVE_MPROTECT /* code's not tested yet */

#if HAVE_MMAP || HAVE_MPROTECT || HAVE_MADVISE
#include <sys/mman.h>
#endif

#ifndef MAP_FILE
#define MAP_FILE 0
#endif

static int debug_windows;

void
bfd_free_window (windowp)
     bfd_window *windowp;
{
  bfd_window_internal *i = windowp->i;
  windowp->i = 0;
  windowp->data = 0;
  if (i == 0)
    return;
  i->refcount--;
  if (debug_windows)
    fprintf (stderr, "freeing window @%p<%p,%lx,%p>\n",
	     windowp, windowp->data, windowp->size, windowp->i);
  if (i->refcount != 0)
    return;

  if (i->mapped)
    {
#ifdef HAVE_MMAP
      munmap (i->data, i->size);
      goto no_free;
#else
      abort ();
#endif
    }
#ifdef HAVE_MPROTECT
  mprotect (i->data, i->size, PROT_READ | PROT_WRITE);
#endif
  free (i->data);
#ifdef HAVE_MMAP
 no_free:
#endif
  i->data = 0;
  /* There should be no more references to i at this point.  */
  free (i);
}

static int ok_to_map = 1;

boolean
bfd_get_file_window (abfd, offset, size, windowp, writable)
     bfd *abfd;
     file_ptr offset;
     bfd_size_type size;
     bfd_window *windowp;
     boolean writable;
{
  static size_t pagesize;
  bfd_window_internal *i = windowp->i;
  size_t size_to_alloc = size;

  if (debug_windows)
    fprintf (stderr, "bfd_get_file_window (%p, %6ld, %6ld, %p<%p,%lx,%p>, %d)",
	     abfd, (long) offset, (long) size,
	     windowp, windowp->data, (unsigned long) windowp->size,
	     windowp->i, writable);

  /* Make sure we know the page size, so we can be friendly to mmap.  */
  if (pagesize == 0)
    pagesize = getpagesize ();
  if (pagesize == 0)
    abort ();

  if (i == 0)
    {
      windowp->i = i = (bfd_window_internal *) bfd_zmalloc (sizeof (bfd_window_internal));
      if (i == 0)
	return false;
      i->data = 0;
    }
#ifdef HAVE_MMAP
  if (ok_to_map
      && (i->data == 0 || i->mapped == 1)
      && (abfd->flags & BFD_IN_MEMORY) == 0)
    {
      file_ptr file_offset, offset2;
      size_t real_size;
      int fd;
      FILE *f;

      /* Find the real file and the real offset into it.  */
      while (abfd->my_archive != NULL)
	{
	  offset += abfd->origin;
	  abfd = abfd->my_archive;
	}
      f = bfd_cache_lookup (abfd);
      fd = fileno (f);

      /* Compute offsets and size for mmap and for the user's data.  */
      offset2 = offset % pagesize;
      if (offset2 < 0)
	abort ();
      file_offset = offset - offset2;
      real_size = offset + size - file_offset;
      real_size = real_size + pagesize - 1;
      real_size -= real_size % pagesize;

      /* If we're re-using a memory region, make sure it's big enough.  */
      if (i->data && i->size < size)
	{
	  munmap (i->data, i->size);
	  i->data = 0;
	}
      i->data = mmap (i->data, real_size,
		      writable ? PROT_WRITE | PROT_READ : PROT_READ,
		      (writable
		       ? MAP_FILE | MAP_PRIVATE
		       : MAP_FILE | MAP_SHARED),
		      fd, file_offset);
      if (i->data == (PTR) -1)
	{
	  /* An error happened.  Report it, or try using malloc, or
	     something.  */
	  bfd_set_error (bfd_error_system_call);
	  i->data = 0;
	  windowp->data = 0;
	  if (debug_windows)
	    fprintf (stderr, "\t\tmmap failed!\n");
	  return false;
	}
      if (debug_windows)
	fprintf (stderr, "\n\tmapped %ld at %p, offset is %ld\n",
		 (long) real_size, i->data, (long) offset2);
      i->size = real_size;
      windowp->data = (PTR) ((bfd_byte *) i->data + offset2);
      windowp->size = size;
      i->mapped = 1;
      return true;
    }
  else if (debug_windows)
    {
      if (ok_to_map)
	fprintf (stderr, _("not mapping: data=%lx mapped=%d\n"),
		 (unsigned long) i->data, (int) i->mapped);
      else
	fprintf (stderr, _("not mapping: env var not set\n"));
    }
#else
  ok_to_map = 0;
#endif

#ifdef HAVE_MPROTECT
  if (!writable)
    {
      size_to_alloc += pagesize - 1;
      size_to_alloc -= size_to_alloc % pagesize;
    }
#endif
  if (debug_windows)
    fprintf (stderr, "\n\t%s(%6ld)",
	     i->data ? "realloc" : " malloc", (long) size_to_alloc);
  i->data = (PTR) bfd_realloc (i->data, size_to_alloc);
  if (debug_windows)
    fprintf (stderr, "\t-> %p\n", i->data);
  i->refcount = 1;
  if (i->data == NULL)
    {
      if (size_to_alloc == 0)
	return true;
      bfd_set_error (bfd_error_no_memory);
      return false;
    }
  if (bfd_seek (abfd, offset, SEEK_SET) != 0)
    return false;
  i->size = bfd_read (i->data, size, 1, abfd);
  if (i->size != size)
    return false;
  i->mapped = 0;
#ifdef HAVE_MPROTECT
  if (!writable)
    {
      if (debug_windows)
	fprintf (stderr, "\tmprotect (%p, %ld, PROT_READ)\n", i->data,
		 (long) i->size);
      mprotect (i->data, i->size, PROT_READ);
    }
#endif
  windowp->data = i->data;
  windowp->size = i->size;
  return true;
}

#endif /* USE_MMAP */

bfd_size_type
bfd_write (ptr, size, nitems, abfd)
     CONST PTR ptr;
     bfd_size_type size;
     bfd_size_type nitems;
     bfd *abfd;
{
  long nwrote;

  if ((abfd->flags & BFD_IN_MEMORY) != 0)
    {
      struct bfd_in_memory *bim = (struct bfd_in_memory *) (abfd->iostream);
      size *= nitems;
      if (abfd->where + size > bim->size)
	{
	  long newsize, oldsize = (bim->size + 127) & ~127;
	  bim->size = abfd->where + size;
	  /* Round up to cut down on memory fragmentation */
	  newsize = (bim->size + 127) & ~127;
	  if (newsize > oldsize)
	    {
	      bim->buffer = bfd_realloc (bim->buffer, newsize);
	      if (bim->buffer == 0)
		{
		  bim->size = 0;
		  return 0;
		}
	    }
	}
      memcpy (bim->buffer + abfd->where, ptr, size);
      abfd->where += size;
      return size;
    }

  nwrote = fwrite (ptr, 1, (size_t) (size * nitems),
		   bfd_cache_lookup (abfd));
  if (nwrote > 0)
    abfd->where += nwrote;
  if ((bfd_size_type) nwrote != size * nitems)
    {
#ifdef ENOSPC
      if (nwrote >= 0)
	errno = ENOSPC;
#endif
      bfd_set_error (bfd_error_system_call);
    }
  return nwrote;
}

/*
INTERNAL_FUNCTION
	bfd_write_bigendian_4byte_int

SYNOPSIS
	void bfd_write_bigendian_4byte_int(bfd *abfd,  int i);

DESCRIPTION
	Write a 4 byte integer @var{i} to the output BFD @var{abfd}, in big
	endian order regardless of what else is going on.  This is useful in
	archives.

*/
void
bfd_write_bigendian_4byte_int (abfd, i)
     bfd *abfd;
     int i;
{
  bfd_byte buffer[4];
  bfd_putb32(i, buffer);
  if (bfd_write((PTR)buffer, 4, 1, abfd) != 4)
    abort ();
}

long
bfd_tell (abfd)
     bfd *abfd;
{
  file_ptr ptr;

  if ((abfd->flags & BFD_IN_MEMORY) != 0)
    return abfd->where;

  ptr = ftell (bfd_cache_lookup(abfd));

  if (abfd->my_archive)
    ptr -= abfd->origin;
  abfd->where = ptr;
  return ptr;
}

int
bfd_flush (abfd)
     bfd *abfd;
{
  if ((abfd->flags & BFD_IN_MEMORY) != 0)
    return 0;
  return fflush (bfd_cache_lookup(abfd));
}

/* Returns 0 for success, negative value for failure (in which case
   bfd_get_error can retrieve the error code).  */
int
bfd_stat (abfd, statbuf)
     bfd *abfd;
     struct stat *statbuf;
{
  FILE *f;
  int result;

  if ((abfd->flags & BFD_IN_MEMORY) != 0)
    abort ();

  f = bfd_cache_lookup (abfd);
  if (f == NULL)
    {
      bfd_set_error (bfd_error_system_call);
      return -1;
    }
  result = fstat (fileno (f), statbuf);
  if (result < 0)
    bfd_set_error (bfd_error_system_call);
  return result;
}

/* Returns 0 for success, nonzero for failure (in which case bfd_get_error
   can retrieve the error code).  */

int
bfd_seek (abfd, position, direction)
     bfd *abfd;
     file_ptr position;
     int direction;
{
  int result;
  FILE *f;
  file_ptr file_position;
  /* For the time being, a BFD may not seek to it's end.  The problem
     is that we don't easily have a way to recognize the end of an
     element in an archive.  */

  BFD_ASSERT (direction == SEEK_SET || direction == SEEK_CUR);

  if (direction == SEEK_CUR && position == 0)
    return 0;

  if ((abfd->flags & BFD_IN_MEMORY) != 0)
    {
      struct bfd_in_memory *bim;

      bim = (struct bfd_in_memory *) abfd->iostream;

      if (direction == SEEK_SET)
	abfd->where = position;
      else
	abfd->where += position;

      if ((bfd_size_type) abfd->where > bim->size)
	{
	  if ((abfd->direction == write_direction) ||
	      (abfd->direction == both_direction))
	    {
	      long newsize, oldsize = (bim->size + 127) & ~127;
	      bim->size = abfd->where;
	      /* Round up to cut down on memory fragmentation */
	      newsize = (bim->size + 127) & ~127;
	      if (newsize > oldsize)
	        {
		  bim->buffer = bfd_realloc (bim->buffer, newsize);
		  if (bim->buffer == 0)
		    {
		      bim->size = 0;
		      bfd_set_error (bfd_error_no_memory);
		      return -1;
		    }
	        }
	    }
	  else
	    {
	      abfd->where = bim->size;
	      bfd_set_error (bfd_error_file_truncated);
	      return -1;
	    }
	}
      return 0;
    }

  if (abfd->format != bfd_archive && abfd->my_archive == 0)
    {
#if 0
      /* Explanation for this code: I'm only about 95+% sure that the above
	 conditions are sufficient and that all i/o calls are properly
	 adjusting the `where' field.  So this is sort of an `assert'
	 that the `where' field is correct.  If we can go a while without
	 tripping the abort, we can probably safely disable this code,
	 so that the real optimizations happen.  */
      file_ptr where_am_i_now;
      where_am_i_now = ftell (bfd_cache_lookup (abfd));
      if (abfd->my_archive)
	where_am_i_now -= abfd->origin;
      if (where_am_i_now != abfd->where)
	abort ();
#endif
      if (direction == SEEK_SET && position == abfd->where)
	return 0;
    }
  else
    {
      /* We need something smarter to optimize access to archives.
	 Currently, anything inside an archive is read via the file
	 handle for the archive.  Which means that a bfd_seek on one
	 component affects the `current position' in the archive, as
	 well as in any other component.

	 It might be sufficient to put a spike through the cache
	 abstraction, and look to the archive for the file position,
	 but I think we should try for something cleaner.

	 In the meantime, no optimization for archives.  */
    }

  f = bfd_cache_lookup (abfd);
  file_position = position;
  if (direction == SEEK_SET && abfd->my_archive != NULL)
    file_position += abfd->origin;

  result = fseek (f, file_position, direction);

  if (result != 0)
    {
      int hold_errno = errno;

      /* Force redetermination of `where' field.  */
      bfd_tell (abfd);

      /* An EINVAL error probably means that the file offset was
         absurd.  */
      if (hold_errno == EINVAL)
	bfd_set_error (bfd_error_file_truncated);
      else
	{
	  bfd_set_error (bfd_error_system_call);
	  errno = hold_errno;
	}
    }
  else
    {
      /* Adjust `where' field.  */
      if (direction == SEEK_SET)
	abfd->where = position;
      else
	abfd->where += position;
    }
  return result;
}

/** The do-it-yourself (byte) sex-change kit */

/* The middle letter e.g. get<b>short indicates Big or Little endian
   target machine.  It doesn't matter what the byte order of the host
   machine is; these routines work for either.  */

/* FIXME: Should these take a count argument?
   Answer (gnu@cygnus.com):  No, but perhaps they should be inline
                             functions in swap.h #ifdef __GNUC__.
                             Gprof them later and find out.  */

/*
FUNCTION
	bfd_put_size
FUNCTION
	bfd_get_size

DESCRIPTION
	These macros as used for reading and writing raw data in
	sections; each access (except for bytes) is vectored through
	the target format of the BFD and mangled accordingly. The
	mangling performs any necessary endian translations and
	removes alignment restrictions.  Note that types accepted and
	returned by these macros are identical so they can be swapped
	around in macros---for example, @file{libaout.h} defines <<GET_WORD>>
	to either <<bfd_get_32>> or <<bfd_get_64>>.

	In the put routines, @var{val} must be a <<bfd_vma>>.  If we are on a
	system without prototypes, the caller is responsible for making
	sure that is true, with a cast if necessary.  We don't cast
	them in the macro definitions because that would prevent <<lint>>
	or <<gcc -Wall>> from detecting sins such as passing a pointer.
	To detect calling these with less than a <<bfd_vma>>, use
	<<gcc -Wconversion>> on a host with 64 bit <<bfd_vma>>'s.

.
.{* Byte swapping macros for user section data.  *}
.
.#define bfd_put_8(abfd, val, ptr) \
.                ((void) (*((unsigned char *) (ptr)) = (unsigned char) (val)))
.#define bfd_put_signed_8 \
.		bfd_put_8
.#define bfd_get_8(abfd, ptr) \
.                (*(unsigned char *) (ptr))
.#define bfd_get_signed_8(abfd, ptr) \
.		((*(unsigned char *) (ptr) ^ 0x80) - 0x80)
.
.#define bfd_put_16(abfd, val, ptr) \
.                BFD_SEND(abfd, bfd_putx16, ((val),(ptr)))
.#define bfd_put_signed_16 \
.		 bfd_put_16
.#define bfd_get_16(abfd, ptr) \
.                BFD_SEND(abfd, bfd_getx16, (ptr))
.#define bfd_get_signed_16(abfd, ptr) \
.         	 BFD_SEND (abfd, bfd_getx_signed_16, (ptr))
.
.#define bfd_put_32(abfd, val, ptr) \
.                BFD_SEND(abfd, bfd_putx32, ((val),(ptr)))
.#define bfd_put_signed_32 \
.		 bfd_put_32
.#define bfd_get_32(abfd, ptr) \
.                BFD_SEND(abfd, bfd_getx32, (ptr))
.#define bfd_get_signed_32(abfd, ptr) \
.		 BFD_SEND(abfd, bfd_getx_signed_32, (ptr))
.
.#define bfd_put_64(abfd, val, ptr) \
.                BFD_SEND(abfd, bfd_putx64, ((val), (ptr)))
.#define bfd_put_signed_64 \
.		 bfd_put_64
.#define bfd_get_64(abfd, ptr) \
.                BFD_SEND(abfd, bfd_getx64, (ptr))
.#define bfd_get_signed_64(abfd, ptr) \
.		 BFD_SEND(abfd, bfd_getx_signed_64, (ptr))
.
.#define bfd_get(bits, abfd, ptr)				\
.                ((bits) == 8 ? bfd_get_8 (abfd, ptr)		\
.		 : (bits) == 16 ? bfd_get_16 (abfd, ptr)	\
.		 : (bits) == 32 ? bfd_get_32 (abfd, ptr)	\
.		 : (bits) == 64 ? bfd_get_64 (abfd, ptr)	\
.		 : (abort (), (bfd_vma) - 1))
.
.#define bfd_put(bits, abfd, val, ptr)				\
.                ((bits) == 8 ? bfd_put_8 (abfd, val, ptr)	\
.		 : (bits) == 16 ? bfd_put_16 (abfd, val, ptr)	\
.		 : (bits) == 32 ? bfd_put_32 (abfd, val, ptr)	\
.		 : (bits) == 64 ? bfd_put_64 (abfd, val, ptr)	\
.		 : (abort (), (void) 0))
.
*/

/*
FUNCTION
	bfd_h_put_size
	bfd_h_get_size

DESCRIPTION
	These macros have the same function as their <<bfd_get_x>>
	bretheren, except that they are used for removing information
	for the header records of object files. Believe it or not,
	some object files keep their header records in big endian
	order and their data in little endian order.
.
.{* Byte swapping macros for file header data.  *}
.
.#define bfd_h_put_8(abfd, val, ptr) \
.		bfd_put_8 (abfd, val, ptr)
.#define bfd_h_put_signed_8(abfd, val, ptr) \
.		bfd_put_8 (abfd, val, ptr)
.#define bfd_h_get_8(abfd, ptr) \
.		bfd_get_8 (abfd, ptr)
.#define bfd_h_get_signed_8(abfd, ptr) \
.		bfd_get_signed_8 (abfd, ptr)
.
.#define bfd_h_put_16(abfd, val, ptr) \
.                BFD_SEND(abfd, bfd_h_putx16,(val,ptr))
.#define bfd_h_put_signed_16 \
.		 bfd_h_put_16
.#define bfd_h_get_16(abfd, ptr) \
.                BFD_SEND(abfd, bfd_h_getx16,(ptr))
.#define bfd_h_get_signed_16(abfd, ptr) \
.		 BFD_SEND(abfd, bfd_h_getx_signed_16, (ptr))
.
.#define bfd_h_put_32(abfd, val, ptr) \
.                BFD_SEND(abfd, bfd_h_putx32,(val,ptr))
.#define bfd_h_put_signed_32 \
.		 bfd_h_put_32
.#define bfd_h_get_32(abfd, ptr) \
.                BFD_SEND(abfd, bfd_h_getx32,(ptr))
.#define bfd_h_get_signed_32(abfd, ptr) \
.		 BFD_SEND(abfd, bfd_h_getx_signed_32, (ptr))
.
.#define bfd_h_put_64(abfd, val, ptr) \
.                BFD_SEND(abfd, bfd_h_putx64,(val, ptr))
.#define bfd_h_put_signed_64 \
.		 bfd_h_put_64
.#define bfd_h_get_64(abfd, ptr) \
.                BFD_SEND(abfd, bfd_h_getx64,(ptr))
.#define bfd_h_get_signed_64(abfd, ptr) \
.		 BFD_SEND(abfd, bfd_h_getx_signed_64, (ptr))
.
*/

/* Sign extension to bfd_signed_vma.  */
#define COERCE16(x) (((bfd_signed_vma) (x) ^ 0x8000) - 0x8000)
#define COERCE32(x) \
  ((bfd_signed_vma) (long) (((unsigned long) (x) ^ 0x80000000) - 0x80000000))
#define EIGHT_GAZILLION (((BFD_HOST_64_BIT)0x80000000) << 32)
#define COERCE64(x) \
  (((bfd_signed_vma) (x) ^ EIGHT_GAZILLION) - EIGHT_GAZILLION)

bfd_vma
bfd_getb16 (addr)
     register const bfd_byte *addr;
{
  return (addr[0] << 8) | addr[1];
}

bfd_vma
bfd_getl16 (addr)
     register const bfd_byte *addr;
{
  return (addr[1] << 8) | addr[0];
}

bfd_signed_vma
bfd_getb_signed_16 (addr)
     register const bfd_byte *addr;
{
  return COERCE16((addr[0] << 8) | addr[1]);
}

bfd_signed_vma
bfd_getl_signed_16 (addr)
     register const bfd_byte *addr;
{
  return COERCE16((addr[1] << 8) | addr[0]);
}

void
bfd_putb16 (data, addr)
     bfd_vma data;
     register bfd_byte *addr;
{
  addr[0] = (bfd_byte) (data >> 8);
  addr[1] = (bfd_byte) data;
}

void
bfd_putl16 (data, addr)
     bfd_vma data;
     register bfd_byte *addr;
{
  addr[0] = (bfd_byte) data;
  addr[1] = (bfd_byte) (data >> 8);
}

bfd_vma
bfd_getb32 (addr)
     register const bfd_byte *addr;
{
  unsigned long v;

  v = (unsigned long) addr[0] << 24;
  v |= (unsigned long) addr[1] << 16;
  v |= (unsigned long) addr[2] << 8;
  v |= (unsigned long) addr[3];
  return (bfd_vma) v;
}

bfd_vma
bfd_getl32 (addr)
     register const bfd_byte *addr;
{
  unsigned long v;

  v = (unsigned long) addr[0];
  v |= (unsigned long) addr[1] << 8;
  v |= (unsigned long) addr[2] << 16;
  v |= (unsigned long) addr[3] << 24;
  return (bfd_vma) v;
}

bfd_signed_vma
bfd_getb_signed_32 (addr)
     register const bfd_byte *addr;
{
  unsigned long v;

  v = (unsigned long) addr[0] << 24;
  v |= (unsigned long) addr[1] << 16;
  v |= (unsigned long) addr[2] << 8;
  v |= (unsigned long) addr[3];
  return COERCE32 (v);
}

bfd_signed_vma
bfd_getl_signed_32 (addr)
     register const bfd_byte *addr;
{
  unsigned long v;

  v = (unsigned long) addr[0];
  v |= (unsigned long) addr[1] << 8;
  v |= (unsigned long) addr[2] << 16;
  v |= (unsigned long) addr[3] << 24;
  return COERCE32 (v);
}

bfd_vma
bfd_getb64 (addr)
     register const bfd_byte *addr ATTRIBUTE_UNUSED;
{
#ifdef BFD64
  bfd_vma low, high;

  high= ((((((((addr[0]) << 8) |
              addr[1]) << 8) |
            addr[2]) << 8) |
          addr[3]) );

  low = (((((((((bfd_vma)addr[4]) << 8) |
              addr[5]) << 8) |
            addr[6]) << 8) |
          addr[7]));

  return high << 32 | low;
#else
  BFD_FAIL();
  return 0;
#endif
}

bfd_vma
bfd_getl64 (addr)
     register const bfd_byte *addr ATTRIBUTE_UNUSED;
{
#ifdef BFD64
  bfd_vma low, high;
  high= (((((((addr[7] << 8) |
              addr[6]) << 8) |
            addr[5]) << 8) |
          addr[4]));

  low = ((((((((bfd_vma)addr[3] << 8) |
              addr[2]) << 8) |
            addr[1]) << 8) |
          addr[0]) );

  return high << 32 | low;
#else
  BFD_FAIL();
  return 0;
#endif

}

bfd_signed_vma
bfd_getb_signed_64 (addr)
     register const bfd_byte *addr ATTRIBUTE_UNUSED;
{
#ifdef BFD64
  bfd_vma low, high;

  high= ((((((((addr[0]) << 8) |
              addr[1]) << 8) |
            addr[2]) << 8) |
          addr[3]) );

  low = (((((((((bfd_vma)addr[4]) << 8) |
              addr[5]) << 8) |
            addr[6]) << 8) |
          addr[7]));

  return COERCE64(high << 32 | low);
#else
  BFD_FAIL();
  return 0;
#endif
}

bfd_signed_vma
bfd_getl_signed_64 (addr)
     register const bfd_byte *addr ATTRIBUTE_UNUSED;
{
#ifdef BFD64
  bfd_vma low, high;
  high= (((((((addr[7] << 8) |
              addr[6]) << 8) |
            addr[5]) << 8) |
          addr[4]));

  low = ((((((((bfd_vma)addr[3] << 8) |
              addr[2]) << 8) |
            addr[1]) << 8) |
          addr[0]) );

  return COERCE64(high << 32 | low);
#else
  BFD_FAIL();
  return 0;
#endif
}

void
bfd_putb32 (data, addr)
     bfd_vma data;
     register bfd_byte *addr;
{
        addr[0] = (bfd_byte) (data >> 24);
        addr[1] = (bfd_byte) (data >> 16);
        addr[2] = (bfd_byte) (data >>  8);
        addr[3] = (bfd_byte) data;
}

void
bfd_putl32 (data, addr)
     bfd_vma data;
     register bfd_byte *addr;
{
        addr[0] = (bfd_byte) data;
        addr[1] = (bfd_byte) (data >>  8);
        addr[2] = (bfd_byte) (data >> 16);
        addr[3] = (bfd_byte) (data >> 24);
}

void
bfd_putb64 (data, addr)
     bfd_vma data ATTRIBUTE_UNUSED;
     register bfd_byte *addr ATTRIBUTE_UNUSED;
{
#ifdef BFD64
  addr[0] = (bfd_byte) (data >> (7*8));
  addr[1] = (bfd_byte) (data >> (6*8));
  addr[2] = (bfd_byte) (data >> (5*8));
  addr[3] = (bfd_byte) (data >> (4*8));
  addr[4] = (bfd_byte) (data >> (3*8));
  addr[5] = (bfd_byte) (data >> (2*8));
  addr[6] = (bfd_byte) (data >> (1*8));
  addr[7] = (bfd_byte) (data >> (0*8));
#else
  BFD_FAIL();
#endif
}

void
bfd_putl64 (data, addr)
     bfd_vma data ATTRIBUTE_UNUSED;
     register bfd_byte *addr ATTRIBUTE_UNUSED;
{
#ifdef BFD64
  addr[7] = (bfd_byte) (data >> (7*8));
  addr[6] = (bfd_byte) (data >> (6*8));
  addr[5] = (bfd_byte) (data >> (5*8));
  addr[4] = (bfd_byte) (data >> (4*8));
  addr[3] = (bfd_byte) (data >> (3*8));
  addr[2] = (bfd_byte) (data >> (2*8));
  addr[1] = (bfd_byte) (data >> (1*8));
  addr[0] = (bfd_byte) (data >> (0*8));
#else
  BFD_FAIL();
#endif
}

void
bfd_put_bits (data, addr, bits, big_p)
     bfd_vma data;
     bfd_byte *addr;
     int bits;
     boolean big_p;
{
  int i;
  int bytes;

  if (bits % 8 != 0)
    abort ();

  bytes = bits / 8;
  for (i = 0; i < bytes; i++)
    {
      int index = big_p ? bytes - i - 1 : i;

      addr[index] = (bfd_byte) data;
      data >>= 8;
    }
}

bfd_vma
bfd_get_bits (addr, bits, big_p)
     bfd_byte *addr;
     int bits;
     boolean big_p;
{
  bfd_vma data;
  int i;
  int bytes;

  if (bits % 8 != 0)
    abort ();

  data = 0;
  bytes = bits / 8;
  for (i = 0; i < bytes; i++)
    {
      int index = big_p ? i : bytes - i - 1;

      data = (data << 8) | addr[index];
    }

  return data;
}

/* Default implementation */

boolean
_bfd_generic_get_section_contents (abfd, section, location, offset, count)
     bfd *abfd;
     sec_ptr section;
     PTR location;
     file_ptr offset;
     bfd_size_type count;
{
  if (count == 0)
    return true;

  if ((bfd_size_type) (offset + count) > section->_raw_size)
    {
      bfd_set_error (bfd_error_invalid_operation);
      return false;
    }

  if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0
      || bfd_read (location, (bfd_size_type) 1, count, abfd) != count)
    return false;

  return true;
}

boolean
_bfd_generic_get_section_contents_in_window (abfd, section, w, offset, count)
     bfd *abfd ATTRIBUTE_UNUSED;
     sec_ptr section ATTRIBUTE_UNUSED;
     bfd_window *w ATTRIBUTE_UNUSED;
     file_ptr offset ATTRIBUTE_UNUSED;
     bfd_size_type count ATTRIBUTE_UNUSED;
{
#ifdef USE_MMAP
  if (count == 0)
    return true;
  if (abfd->xvec->_bfd_get_section_contents != _bfd_generic_get_section_contents)
    {
      /* We don't know what changes the bfd's get_section_contents
	 method may have to make.  So punt trying to map the file
	 window, and let get_section_contents do its thing.  */
      /* @@ FIXME : If the internal window has a refcount of 1 and was
	 allocated with malloc instead of mmap, just reuse it.  */
      bfd_free_window (w);
      w->i = (bfd_window_internal *) bfd_zmalloc (sizeof (bfd_window_internal));
      if (w->i == NULL)
	return false;
      w->i->data = (PTR) bfd_malloc ((size_t) count);
      if (w->i->data == NULL)
	{
	  free (w->i);
	  w->i = NULL;
	  return false;
	}
      w->i->mapped = 0;
      w->i->refcount = 1;
      w->size = w->i->size = count;
      w->data = w->i->data;
      return bfd_get_section_contents (abfd, section, w->data, offset, count);
    }
  if ((bfd_size_type) (offset+count) > section->_raw_size
      || (bfd_get_file_window (abfd, section->filepos + offset, count, w, true)
	  == false))
    return false;
  return true;
#else
  abort ();
#endif
}

/* This generic function can only be used in implementations where creating
   NEW sections is disallowed.  It is useful in patching existing sections
   in read-write files, though.  See other set_section_contents functions
   to see why it doesn't work for new sections.  */
boolean
_bfd_generic_set_section_contents (abfd, section, location, offset, count)
     bfd *abfd;
     sec_ptr section;
     PTR location;
     file_ptr offset;
     bfd_size_type count;
{
  if (count == 0)
    return true;

  if (bfd_seek (abfd, (file_ptr) (section->filepos + offset), SEEK_SET) == -1
      || bfd_write (location, (bfd_size_type) 1, count, abfd) != count)
    return false;

  return true;
}

/*
INTERNAL_FUNCTION
	bfd_log2

SYNOPSIS
	unsigned int bfd_log2(bfd_vma x);

DESCRIPTION
	Return the log base 2 of the value supplied, rounded up.  E.g., an
	@var{x} of 1025 returns 11.
*/

unsigned int
bfd_log2 (x)
     bfd_vma x;
{
  unsigned int result = 0;

  while ((x = (x >> 1)) != 0)
    ++result;
  return result;
}

boolean
bfd_generic_is_local_label_name (abfd, name)
     bfd *abfd;
     const char *name;
{
  char locals_prefix = (bfd_get_symbol_leading_char (abfd) == '_') ? 'L' : '.';

  return (name[0] == locals_prefix);
}

/*  Can be used from / for bfd_merge_private_bfd_data to check that
    endianness matches between input and output file.  Returns
    true for a match, otherwise returns false and emits an error.  */
boolean
_bfd_generic_verify_endian_match (ibfd, obfd)
     bfd *ibfd;
     bfd *obfd;
{
  if (ibfd->xvec->byteorder != obfd->xvec->byteorder
      && ibfd->xvec->byteorder != BFD_ENDIAN_UNKNOWN
      && obfd->xvec->byteorder != BFD_ENDIAN_UNKNOWN)
    {
      const char *msg;

      if (bfd_big_endian (ibfd))
	msg = _("%s: compiled for a big endian system and target is little endian");
      else
	msg = _("%s: compiled for a little endian system and target is big endian");

      (*_bfd_error_handler) (msg, bfd_get_filename (ibfd));

      bfd_set_error (bfd_error_wrong_format);
      return false;
    }

  return true;
}