aboutsummaryrefslogtreecommitdiff
path: root/bfd/nlmcode.h
blob: 63ac0c300f7632422d3d25e1d3969d87aec0efc6 (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
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
/* NLM (NetWare Loadable Module) executable support for BFD.
   Copyright (C) 1993, 94, 95, 1998 Free Software Foundation, Inc.

   Written by Fred Fish @ Cygnus Support, using ELF support as the
   template.

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"
#include "libnlm.h"

/* The functions in this file do not use the names they appear to use.
   This file is actually compiled multiple times, once for each size
   of NLM target we are using.  At each size we use a different name,
   constructed by the macro nlmNAME.  For example, the function which
   is named nlm_symbol_type below is actually named nlm32_symbol_type
   in the final executable.  */

#define Nlm_External_Fixed_Header	NlmNAME(External_Fixed_Header)
#define Nlm_External_Version_Header	NlmNAME(External_Version_Header)
#define Nlm_External_Copyright_Header	NlmNAME(External_Copyright_Header)
#define Nlm_External_Extended_Header	NlmNAME(External_Extended_Header)
#define Nlm_External_Custom_Header	NlmNAME(External_Custom_Header)
#define Nlm_External_Cygnus_Ext_Header	NlmNAME(External_Cygnus_Ext_Header)

#define nlm_symbol_type			nlmNAME(symbol_type)
#define nlm_get_symtab_upper_bound	nlmNAME(get_symtab_upper_bound)
#define nlm_get_symtab			nlmNAME(get_symtab)
#define nlm_make_empty_symbol		nlmNAME(make_empty_symbol)
#define nlm_print_symbol		nlmNAME(print_symbol)
#define nlm_get_symbol_info		nlmNAME(get_symbol_info)
#define nlm_get_reloc_upper_bound	nlmNAME(get_reloc_upper_bound)
#define nlm_canonicalize_reloc		nlmNAME(canonicalize_reloc)
#define nlm_object_p			nlmNAME(object_p)
#define nlm_set_section_contents	nlmNAME(set_section_contents)
#define nlm_write_object_contents	nlmNAME(write_object_contents)

#define nlm_swap_fixed_header_in(abfd,src,dst) \
  (nlm_swap_fixed_header_in_func(abfd))(abfd,src,dst)
#define nlm_swap_fixed_header_out(abfd,src,dst) \
  (nlm_swap_fixed_header_out_func(abfd))(abfd,src,dst)

/* Forward declarations of static functions */

static boolean add_bfd_section
  PARAMS ((bfd *, char *, file_ptr, bfd_size_type, flagword));
static boolean nlm_swap_variable_header_in
  PARAMS ((bfd *));
static boolean nlm_swap_variable_header_out
  PARAMS ((bfd *));
static boolean find_nonzero
  PARAMS ((PTR, size_t));
static boolean nlm_swap_auxiliary_headers_in
  PARAMS ((bfd *));
static boolean nlm_swap_auxiliary_headers_out
  PARAMS ((bfd *));
static boolean nlm_slurp_symbol_table
  PARAMS ((bfd *));
static boolean nlm_slurp_reloc_fixups
  PARAMS ((bfd *));
static boolean nlm_compute_section_file_positions
  PARAMS ((bfd *));
static int nlm_external_reloc_compare
  PARAMS ((const void *, const void *));

/* Should perhaps use put_offset, put_word, etc.  For now, the two versions
   can be handled by explicitly specifying 32 bits or "the long type".  */
#if ARCH_SIZE == 64
#define put_word	bfd_h_put_64
#define get_word	bfd_h_get_64
#endif
#if ARCH_SIZE == 32
#define put_word	bfd_h_put_32
#define get_word	bfd_h_get_32
#endif

const bfd_target *
nlm_object_p (abfd)
     bfd *abfd;
{
  struct nlm_obj_tdata *preserved_tdata = nlm_tdata (abfd);
  boolean (*backend_object_p) PARAMS ((bfd *));
  PTR x_fxdhdr = NULL;
  Nlm_Internal_Fixed_Header *i_fxdhdrp;
  struct nlm_obj_tdata *new_tdata = NULL;
  const char *signature;
  enum bfd_architecture arch;

  /* Some NLM formats have a prefix before the standard NLM fixed
     header.  */
  backend_object_p = nlm_backend_object_p_func (abfd);
  if (backend_object_p)
    {
      if (!(*backend_object_p) (abfd))
	goto got_wrong_format_error;
    }

  /* Read in the fixed length portion of the NLM header in external format.  */

  x_fxdhdr = (PTR) bfd_malloc ((size_t) nlm_fixed_header_size (abfd));
  if (x_fxdhdr == NULL)
    goto got_no_match;

  if (bfd_read ((PTR) x_fxdhdr, nlm_fixed_header_size (abfd), 1, abfd) !=
      nlm_fixed_header_size (abfd))
    {
      if (bfd_get_error () != bfd_error_system_call)
	goto got_wrong_format_error;
      else
	goto got_no_match;
    }

  /* Allocate an instance of the nlm_obj_tdata structure and hook it up to
     the tdata pointer in the bfd.  */

  new_tdata = ((struct nlm_obj_tdata *)
	       bfd_zalloc (abfd, sizeof (struct nlm_obj_tdata)));
  if (new_tdata == NULL)
    goto got_no_match;

  nlm_tdata (abfd) = new_tdata;

  i_fxdhdrp = nlm_fixed_header (abfd);
  nlm_swap_fixed_header_in (abfd, x_fxdhdr, i_fxdhdrp);
  free (x_fxdhdr);
  x_fxdhdr = NULL;

  /* Check to see if we have an NLM file for this backend by matching
     the NLM signature. */

  signature = nlm_signature (abfd);
  if (signature != NULL
      && *signature != '\0'
      && strncmp ((char *) i_fxdhdrp->signature, signature,
		  NLM_SIGNATURE_SIZE) != 0)
    goto got_wrong_format_error;

  /* There's no supported way to discover the endianess of an NLM, so test for
     a sane version number after doing byte swapping appropriate for this
     XVEC.  (Hack alert!) */

  if (i_fxdhdrp->version > 0xFFFF)
    goto got_wrong_format_error;

  /* There's no supported way to check for 32 bit versus 64 bit addresses,
     so ignore this distinction for now.  (FIXME) */

  /* Swap in the rest of the required header.  */
  if (!nlm_swap_variable_header_in (abfd))
    {
      if (bfd_get_error () != bfd_error_system_call)
	goto got_wrong_format_error;
      else
	goto got_no_match;
    }

  /* Add the sections supplied by all NLM's, and then read in the
     auxiliary headers.  Reading the auxiliary headers may create
     additional sections described in the cygnus_ext header.
     From this point on we assume that we have an NLM, and do not
     treat errors as indicating the wrong format.  */

  if (!add_bfd_section (abfd, NLM_CODE_NAME,
			i_fxdhdrp->codeImageOffset,
			i_fxdhdrp->codeImageSize,
			(SEC_CODE | SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
			 | SEC_RELOC))
      || !add_bfd_section (abfd, NLM_INITIALIZED_DATA_NAME,
			   i_fxdhdrp->dataImageOffset,
			   i_fxdhdrp->dataImageSize,
			   (SEC_DATA | SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
			    | SEC_RELOC))
      || !add_bfd_section (abfd, NLM_UNINITIALIZED_DATA_NAME,
			   (file_ptr) 0,
			   i_fxdhdrp->uninitializedDataSize,
			   SEC_ALLOC))
    goto got_no_match;

  if (!nlm_swap_auxiliary_headers_in (abfd))
    goto got_no_match;

  if (nlm_fixed_header (abfd)->numberOfRelocationFixups != 0
      || nlm_fixed_header (abfd)->numberOfExternalReferences != 0)
    abfd->flags |= HAS_RELOC;
  if (nlm_fixed_header (abfd)->numberOfPublics != 0
      || nlm_fixed_header (abfd)->numberOfDebugRecords != 0
      || nlm_fixed_header (abfd)->numberOfExternalReferences != 0)
    abfd->flags |= HAS_SYMS;

  arch = nlm_architecture (abfd);
  if (arch != bfd_arch_unknown)
    bfd_default_set_arch_mach (abfd, arch, (unsigned long) 0);

  abfd->flags |= EXEC_P;
  bfd_get_start_address (abfd) = nlm_fixed_header (abfd)->codeStartOffset;

  return (abfd->xvec);

got_wrong_format_error:
  bfd_set_error (bfd_error_wrong_format);
got_no_match:
  nlm_tdata (abfd) = preserved_tdata;
  if (new_tdata != NULL)
    bfd_release (abfd, new_tdata);
  if (x_fxdhdr != NULL)
    free (x_fxdhdr);
  return (NULL);
}

/* Add a section to the bfd. */

static boolean
add_bfd_section (abfd, name, offset, size, flags)
     bfd *abfd;
     char *name;
     file_ptr offset;
     bfd_size_type size;
     flagword flags;
{
  asection *newsect;

  newsect = bfd_make_section (abfd, name);
  if (newsect == NULL)
    {
      return (false);
    }
  newsect->vma = 0;		/* NLM's are relocatable. */
  newsect->_raw_size = size;
  newsect->filepos = offset;
  newsect->flags = flags;
  newsect->alignment_power = bfd_log2 (0);	/* FIXME */
  return (true);
}

/* Read and swap in the variable length header.  All the fields must
   exist in the NLM, and must exist in the order they are read here. */

static boolean
nlm_swap_variable_header_in (abfd)
     bfd *abfd;
{
  unsigned char temp[NLM_TARGET_LONG_SIZE];

  /* Read the description length and text members. */

  if (bfd_read ((PTR) & nlm_variable_header (abfd)->descriptionLength,
		sizeof (nlm_variable_header (abfd)->descriptionLength),
		1, abfd) !=
      sizeof (nlm_variable_header (abfd)->descriptionLength))
    return (false);
  if (bfd_read ((PTR) nlm_variable_header (abfd)->descriptionText,
		nlm_variable_header (abfd)->descriptionLength + 1,
		1, abfd) !=
      (bfd_size_type) nlm_variable_header (abfd)->descriptionLength + 1)
    return (false);

  /* Read and convert the stackSize field. */

  if (bfd_read ((PTR) temp, sizeof (temp), 1, abfd) != sizeof (temp))
    return (false);
  nlm_variable_header (abfd)->stackSize = get_word (abfd, (bfd_byte *) temp);

  /* Read and convert the reserved field. */

  if (bfd_read ((PTR) temp, sizeof (temp), 1, abfd) != sizeof (temp))
    return (false);
  nlm_variable_header (abfd)->reserved = get_word (abfd, (bfd_byte *) temp);

  /* Read the oldThreadName field.  This field is a fixed length string. */

  if (bfd_read ((PTR) nlm_variable_header (abfd)->oldThreadName,
		sizeof (nlm_variable_header (abfd)->oldThreadName),
		1, abfd) !=
      sizeof (nlm_variable_header (abfd)->oldThreadName))
    return (false);

  /* Read the screen name length and text members. */

  if (bfd_read ((PTR) & nlm_variable_header (abfd)->screenNameLength,
		sizeof (nlm_variable_header (abfd)->screenNameLength),
		1, abfd) !=
      sizeof (nlm_variable_header (abfd)->screenNameLength))
    return (false);
  if (bfd_read ((PTR) nlm_variable_header (abfd)->screenName,
		nlm_variable_header (abfd)->screenNameLength + 1,
		1, abfd) !=
      (bfd_size_type) nlm_variable_header (abfd)->screenNameLength + 1)
    return (false);

  /* Read the thread name length and text members. */

  if (bfd_read ((PTR) & nlm_variable_header (abfd)->threadNameLength,
		sizeof (nlm_variable_header (abfd)->threadNameLength),
		1, abfd) !=
      sizeof (nlm_variable_header (abfd)->threadNameLength))
    return (false);
  if (bfd_read ((PTR) nlm_variable_header (abfd)->threadName,
		nlm_variable_header (abfd)->threadNameLength + 1,
		1, abfd) !=
      (bfd_size_type) nlm_variable_header (abfd)->threadNameLength + 1)
    return (false);
  return (true);
}

/* Swap and write out the variable length header.  All the fields must
   exist in the NLM, and must exist in this order.  */

static boolean
nlm_swap_variable_header_out (abfd)
     bfd *abfd;
{
  unsigned char temp[NLM_TARGET_LONG_SIZE];

  /* Write the description length and text members. */

  if (bfd_write ((PTR) & nlm_variable_header (abfd)->descriptionLength,
		 sizeof (nlm_variable_header (abfd)->descriptionLength),
		 1, abfd) !=
      sizeof (nlm_variable_header (abfd)->descriptionLength))
    return (false);
  if (bfd_write ((PTR) nlm_variable_header (abfd)->descriptionText,
		 nlm_variable_header (abfd)->descriptionLength + 1,
		 1, abfd) !=
      (bfd_size_type) nlm_variable_header (abfd)->descriptionLength + 1)
    return (false);

  /* Convert and write the stackSize field. */

  put_word (abfd, (bfd_vma) nlm_variable_header (abfd)->stackSize,
	    (bfd_byte *) temp);
  if (bfd_write ((PTR) temp, sizeof (temp), 1, abfd) != sizeof (temp))
    return (false);

  /* Convert and write the reserved field. */

  put_word (abfd, (bfd_vma) nlm_variable_header (abfd)->reserved,
	    (bfd_byte *) temp);
  if (bfd_write ((PTR) temp, sizeof (temp), 1, abfd) != sizeof (temp))
    return (false);

  /* Write the oldThreadName field.  This field is a fixed length string. */

  if (bfd_write ((PTR) nlm_variable_header (abfd)->oldThreadName,
		 sizeof (nlm_variable_header (abfd)->oldThreadName),
		 1, abfd) !=
      sizeof (nlm_variable_header (abfd)->oldThreadName))
    return (false);

  /* Write the screen name length and text members. */

  if (bfd_write ((PTR) & nlm_variable_header (abfd)->screenNameLength,
		 sizeof (nlm_variable_header (abfd)->screenNameLength),
		 1, abfd) !=
      sizeof (nlm_variable_header (abfd)->screenNameLength))
    return (false);
  if (bfd_write ((PTR) nlm_variable_header (abfd)->screenName,
		 nlm_variable_header (abfd)->screenNameLength + 1,
		 1, abfd) !=
      (bfd_size_type) nlm_variable_header (abfd)->screenNameLength + 1)
    return (false);

  /* Write the thread name length and text members. */

  if (bfd_write ((PTR) & nlm_variable_header (abfd)->threadNameLength,
		 sizeof (nlm_variable_header (abfd)->threadNameLength),
		 1, abfd) !=
      sizeof (nlm_variable_header (abfd)->threadNameLength))
    return (false);
  if (bfd_write ((PTR) nlm_variable_header (abfd)->threadName,
		 nlm_variable_header (abfd)->threadNameLength + 1,
		 1, abfd) !=
      (bfd_size_type) nlm_variable_header (abfd)->threadNameLength + 1)
    return (false);
  return (true);
}

/* Read and swap in the contents of all the auxiliary headers.  Because of
   the braindead design, we have to do strcmps on strings of indeterminate
   length to figure out what each auxiliary header is.  Even worse, we have
   no way of knowing how many auxiliary headers there are or where the end
   of the auxiliary headers are, except by finding something that doesn't
   look like a known auxiliary header.  This means that the first new type
   of auxiliary header added will break all existing tools that don't
   recognize it. */

static boolean
nlm_swap_auxiliary_headers_in (abfd)
     bfd *abfd;
{
  char tempstr[16];
  long position;

  for (;;)
    {
      position = bfd_tell (abfd);
      if (bfd_read ((PTR) tempstr, sizeof (tempstr), 1, abfd) !=
	  sizeof (tempstr))
	return (false);
      if (bfd_seek (abfd, position, SEEK_SET) == -1)
	return (false);
      if (strncmp (tempstr, "VeRsIoN#", 8) == 0)
	{
	  Nlm_External_Version_Header thdr;
	  if (bfd_read ((PTR) & thdr, sizeof (thdr), 1, abfd) != sizeof (thdr))
	    return (false);
	  memcpy (nlm_version_header (abfd)->stamp, thdr.stamp,
		  sizeof (thdr.stamp));
	  nlm_version_header (abfd)->majorVersion =
	    get_word (abfd, (bfd_byte *) thdr.majorVersion);
	  nlm_version_header (abfd)->minorVersion =
	    get_word (abfd, (bfd_byte *) thdr.minorVersion);
	  nlm_version_header (abfd)->revision =
	    get_word (abfd, (bfd_byte *) thdr.revision);
	  nlm_version_header (abfd)->year =
	    get_word (abfd, (bfd_byte *) thdr.year);
	  nlm_version_header (abfd)->month =
	    get_word (abfd, (bfd_byte *) thdr.month);
	  nlm_version_header (abfd)->day =
	    get_word (abfd, (bfd_byte *) thdr.day);
	}
      else if (strncmp (tempstr, "MeSsAgEs", 8) == 0)
	{
	  Nlm_External_Extended_Header thdr;
	  if (bfd_read ((PTR) & thdr, sizeof (thdr), 1, abfd) != sizeof (thdr))
	    return (false);
	  memcpy (nlm_extended_header (abfd)->stamp, thdr.stamp,
		  sizeof (thdr.stamp));
	  nlm_extended_header (abfd)->languageID =
	    get_word (abfd, (bfd_byte *) thdr.languageID);
	  nlm_extended_header (abfd)->messageFileOffset =
	    get_word (abfd, (bfd_byte *) thdr.messageFileOffset);
	  nlm_extended_header (abfd)->messageFileLength =
	    get_word (abfd, (bfd_byte *) thdr.messageFileLength);
	  nlm_extended_header (abfd)->messageCount =
	    get_word (abfd, (bfd_byte *) thdr.messageCount);
	  nlm_extended_header (abfd)->helpFileOffset =
	    get_word (abfd, (bfd_byte *) thdr.helpFileOffset);
	  nlm_extended_header (abfd)->helpFileLength =
	    get_word (abfd, (bfd_byte *) thdr.helpFileLength);
	  nlm_extended_header (abfd)->RPCDataOffset =
	    get_word (abfd, (bfd_byte *) thdr.RPCDataOffset);
	  nlm_extended_header (abfd)->RPCDataLength =
	    get_word (abfd, (bfd_byte *) thdr.RPCDataLength);
	  nlm_extended_header (abfd)->sharedCodeOffset =
	    get_word (abfd, (bfd_byte *) thdr.sharedCodeOffset);
	  nlm_extended_header (abfd)->sharedCodeLength =
	    get_word (abfd, (bfd_byte *) thdr.sharedCodeLength);
	  nlm_extended_header (abfd)->sharedDataOffset =
	    get_word (abfd, (bfd_byte *) thdr.sharedDataOffset);
	  nlm_extended_header (abfd)->sharedDataLength =
	    get_word (abfd, (bfd_byte *) thdr.sharedDataLength);
	  nlm_extended_header (abfd)->sharedRelocationFixupOffset =
	    get_word (abfd, (bfd_byte *) thdr.sharedRelocationFixupOffset);
	  nlm_extended_header (abfd)->sharedRelocationFixupCount =
	    get_word (abfd, (bfd_byte *) thdr.sharedRelocationFixupCount);
	  nlm_extended_header (abfd)->sharedExternalReferenceOffset =
	    get_word (abfd, (bfd_byte *) thdr.sharedExternalReferenceOffset);
	  nlm_extended_header (abfd)->sharedExternalReferenceCount =
	    get_word (abfd, (bfd_byte *) thdr.sharedExternalReferenceCount);
	  nlm_extended_header (abfd)->sharedPublicsOffset =
	    get_word (abfd, (bfd_byte *) thdr.sharedPublicsOffset);
	  nlm_extended_header (abfd)->sharedPublicsCount =
	    get_word (abfd, (bfd_byte *) thdr.sharedPublicsCount);
	  nlm_extended_header (abfd)->sharedDebugRecordOffset =
	    get_word (abfd, (bfd_byte *) thdr.sharedDebugRecordOffset);
	  nlm_extended_header (abfd)->sharedDebugRecordCount =
	    get_word (abfd, (bfd_byte *) thdr.sharedDebugRecordCount);
	  nlm_extended_header (abfd)->SharedInitializationOffset =
	    get_word (abfd, (bfd_byte *) thdr.sharedInitializationOffset);
	  nlm_extended_header (abfd)->SharedExitProcedureOffset =
	    get_word (abfd, (bfd_byte *) thdr.SharedExitProcedureOffset);
	  nlm_extended_header (abfd)->productID =
	    get_word (abfd, (bfd_byte *) thdr.productID);
	  nlm_extended_header (abfd)->reserved0 =
	    get_word (abfd, (bfd_byte *) thdr.reserved0);
	  nlm_extended_header (abfd)->reserved1 =
	    get_word (abfd, (bfd_byte *) thdr.reserved1);
	  nlm_extended_header (abfd)->reserved2 =
	    get_word (abfd, (bfd_byte *) thdr.reserved2);
	  nlm_extended_header (abfd)->reserved3 =
	    get_word (abfd, (bfd_byte *) thdr.reserved3);
	  nlm_extended_header (abfd)->reserved4 =
	    get_word (abfd, (bfd_byte *) thdr.reserved4);
	  nlm_extended_header (abfd)->reserved5 =
	    get_word (abfd, (bfd_byte *) thdr.reserved5);
	}
      else if (strncmp (tempstr, "CoPyRiGhT=", 10) == 0)
	{
	  if (bfd_read ((PTR) nlm_copyright_header (abfd)->stamp,
			sizeof (nlm_copyright_header (abfd)->stamp),
			1, abfd)
	      != sizeof (nlm_copyright_header (abfd)->stamp))
	    return (false);
	  if (bfd_read ((PTR) & (nlm_copyright_header (abfd)
				 ->copyrightMessageLength),
			1, 1, abfd) != 1)
	    return (false);
	  /* The copyright message is a variable length string. */
	  if (bfd_read ((PTR) nlm_copyright_header (abfd)->copyrightMessage,
		    nlm_copyright_header (abfd)->copyrightMessageLength + 1,
			1, abfd) !=
	      ((bfd_size_type)
	       nlm_copyright_header (abfd)->copyrightMessageLength + 1))
	    return (false);
	}
      else if (strncmp (tempstr, "CuStHeAd", 8) == 0)
	{
	  Nlm_External_Custom_Header thdr;
	  bfd_size_type hdrLength;
	  file_ptr dataOffset;
	  bfd_size_type dataLength;
	  char dataStamp[8];
	  PTR hdr;

	  /* Read the stamp ("CuStHeAd").  */
	  if (bfd_read ((PTR) thdr.stamp, 1, sizeof (thdr.stamp), abfd)
	      != sizeof (thdr.stamp))
	    return false;
	  /* Read the length of this custom header.  */
	  if (bfd_read ((PTR) thdr.length, 1, sizeof (thdr.length), abfd)
	      != sizeof (thdr.length))
	    return false;
	  hdrLength = get_word (abfd, (bfd_byte *) thdr.length);
	  /* Read further fields if we have them.  */
	  if (hdrLength < NLM_TARGET_LONG_SIZE)
	    dataOffset = 0;
	  else
	    {
	      if (bfd_read ((PTR) thdr.dataOffset, 1,
			    sizeof (thdr.dataOffset), abfd)
		  != sizeof (thdr.dataOffset))
		return false;
	      dataOffset = get_word (abfd, (bfd_byte *) thdr.dataOffset);
	    }
	  if (hdrLength < 2 * NLM_TARGET_LONG_SIZE)
	    dataLength = 0;
	  else
	    {
	      if (bfd_read ((PTR) thdr.dataLength, 1,
			    sizeof (thdr.dataLength), abfd)
		  != sizeof (thdr.dataLength))
		return false;
	      dataLength = get_word (abfd, (bfd_byte *) thdr.dataLength);
	    }
	  if (hdrLength < 2 * NLM_TARGET_LONG_SIZE + 8)
	    memset (dataStamp, 0, sizeof (dataStamp));
	  else
	    {
	      if (bfd_read ((PTR) dataStamp, 1, sizeof (dataStamp), abfd)
		  != sizeof (dataStamp))
		return false;
	    }

	  /* Read the rest of the header, if any.  */
	  if (hdrLength <= 2 * NLM_TARGET_LONG_SIZE + 8)
	    {
	      hdr = NULL;
	      hdrLength = 0;
	    }
	  else
	    {
	      hdrLength -= 2 * NLM_TARGET_LONG_SIZE + 8;
	      hdr = bfd_alloc (abfd, hdrLength);
	      if (hdr == NULL)
		return false;
	      if (bfd_read (hdr, 1, hdrLength, abfd) != hdrLength)
		return false;
	    }

	  /* If we have found a Cygnus header, process it.  Otherwise,
	     just save the associated data without trying to interpret
	     it.  */
	  if (strncmp (dataStamp, "CyGnUsEx", 8) == 0)
	    {
	      file_ptr pos;
	      bfd_byte *contents;
	      bfd_byte *p, *pend;

	      BFD_ASSERT (hdrLength == 0 && hdr == NULL);

	      pos = bfd_tell (abfd);
	      if (bfd_seek (abfd, dataOffset, SEEK_SET) != 0)
		return false;
	      contents = (bfd_byte *) bfd_alloc (abfd, dataLength);
	      if (contents == NULL)
		return false;
	      if (bfd_read (contents, 1, dataLength, abfd) != dataLength)
		return false;
	      if (bfd_seek (abfd, pos, SEEK_SET) != 0)
		return false;

	      memcpy (nlm_cygnus_ext_header (abfd), "CyGnUsEx", 8);
	      nlm_cygnus_ext_header (abfd)->offset = dataOffset;
	      nlm_cygnus_ext_header (abfd)->length = dataLength;

	      /* This data this header points to provides a list of
		 the sections which were in the original object file
		 which was converted to become an NLM.  We locate
		 those sections and add them to the BFD.  Note that
		 this is likely to create a second .text, .data and
		 .bss section; retrieving the sections by name will
		 get the actual NLM sections, which is what we want to
		 happen.  The sections from the original file, which
		 may be subsets of the NLM section, can only be found
		 using bfd_map_over_sections.  */
	      p = contents;
	      pend = p + dataLength;
	      while (p < pend)
		{
		  char *name;
		  size_t l;
		  file_ptr filepos;
		  bfd_size_type size;
		  asection *newsec;

		  /* The format of this information is
		     null terminated section name
		     zeroes to adjust to 4 byte boundary
		     4 byte section data file pointer
		     4 byte section size
		     */

		  name = (char *) p;
		  l = strlen (name) + 1;
		  l = (l + 3) &~ 3;
		  p += l;
		  filepos = bfd_h_get_32 (abfd, p);
		  p += 4;
		  size = bfd_h_get_32 (abfd, p);
		  p += 4;

		  newsec = bfd_make_section_anyway (abfd, name);
		  if (newsec == (asection *) NULL)
		    return false;
		  newsec->_raw_size = size;
		  if (filepos != 0)
		    {
		      newsec->filepos = filepos;
		      newsec->flags |= SEC_HAS_CONTENTS;
		    }
		}
	    }
	  else
	    {
	      memcpy (nlm_custom_header (abfd)->stamp, thdr.stamp,
		      sizeof (thdr.stamp));
	      nlm_custom_header (abfd)->hdrLength = hdrLength;
	      nlm_custom_header (abfd)->dataOffset = dataOffset;
	      nlm_custom_header (abfd)->dataLength = dataLength;
	      memcpy (nlm_custom_header (abfd)->dataStamp, dataStamp,
		      sizeof (dataStamp));
	      nlm_custom_header (abfd)->hdr = hdr;
	    }
	}
      else
	{
	  break;
	}
    }
  return (true);
}

/* Return whether there is a non-zero byte in a memory block.  */

static boolean
find_nonzero (buf, size)
     PTR buf;
     size_t size;
{
  char *p = (char *) buf;

  while (size-- != 0)
    if (*p++ != 0)
      return true;
  return false;
}

/* Swap out the contents of the auxiliary headers.  We create those
   auxiliary headers which have been set non-zero.  We do not require
   the caller to set up the stamp fields.  */

static boolean
nlm_swap_auxiliary_headers_out (abfd)
     bfd *abfd;
{
  /* Write out the version header if there is one.  */
  if (find_nonzero ((PTR) nlm_version_header (abfd),
		    sizeof (Nlm_Internal_Version_Header)))
    {
      Nlm_External_Version_Header thdr;

      memcpy (thdr.stamp, "VeRsIoN#", 8);
      put_word (abfd, (bfd_vma) nlm_version_header (abfd)->majorVersion,
		(bfd_byte *) thdr.majorVersion);
      put_word (abfd, (bfd_vma) nlm_version_header (abfd)->minorVersion,
		(bfd_byte *) thdr.minorVersion);
      put_word (abfd, (bfd_vma) nlm_version_header (abfd)->revision,
		(bfd_byte *) thdr.revision);
      put_word (abfd, (bfd_vma) nlm_version_header (abfd)->year,
		(bfd_byte *) thdr.year);
      put_word (abfd, (bfd_vma) nlm_version_header (abfd)->month,
		(bfd_byte *) thdr.month);
      put_word (abfd, (bfd_vma) nlm_version_header (abfd)->day,
		(bfd_byte *) thdr.day);
      if (bfd_write ((PTR) & thdr, sizeof (thdr), 1, abfd) != sizeof (thdr))
	return false;
    }

  /* Write out the extended header if there is one.  */
  if (find_nonzero ((PTR) nlm_extended_header (abfd),
		    sizeof (Nlm_Internal_Extended_Header)))
    {
      Nlm_External_Extended_Header thdr;

      memcpy (thdr.stamp, "MeSsAgEs", 8);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->languageID,
		(bfd_byte *) thdr.languageID);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->messageFileOffset,
		(bfd_byte *) thdr.messageFileOffset);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->messageFileLength,
		(bfd_byte *) thdr.messageFileLength);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->messageCount,
		(bfd_byte *) thdr.messageCount);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->helpFileOffset,
		(bfd_byte *) thdr.helpFileOffset);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->helpFileLength,
		(bfd_byte *) thdr.helpFileLength);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->RPCDataOffset,
		(bfd_byte *) thdr.RPCDataOffset);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->RPCDataLength,
		(bfd_byte *) thdr.RPCDataLength);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->sharedCodeOffset,
		(bfd_byte *) thdr.sharedCodeOffset);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->sharedCodeLength,
		(bfd_byte *) thdr.sharedCodeLength);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->sharedDataOffset,
		(bfd_byte *) thdr.sharedDataOffset);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->sharedDataLength,
		(bfd_byte *) thdr.sharedDataLength);
      put_word (abfd,
	  (bfd_vma) nlm_extended_header (abfd)->sharedRelocationFixupOffset,
		(bfd_byte *) thdr.sharedRelocationFixupOffset);
      put_word (abfd,
	   (bfd_vma) nlm_extended_header (abfd)->sharedRelocationFixupCount,
		(bfd_byte *) thdr.sharedRelocationFixupCount);
      put_word (abfd,
	(bfd_vma) nlm_extended_header (abfd)->sharedExternalReferenceOffset,
		(bfd_byte *) thdr.sharedExternalReferenceOffset);
      put_word (abfd,
	 (bfd_vma) nlm_extended_header (abfd)->sharedExternalReferenceCount,
		(bfd_byte *) thdr.sharedExternalReferenceCount);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->sharedPublicsOffset,
		(bfd_byte *) thdr.sharedPublicsOffset);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->sharedPublicsCount,
		(bfd_byte *) thdr.sharedPublicsCount);
      put_word (abfd,
	      (bfd_vma) nlm_extended_header (abfd)->sharedDebugRecordOffset,
		(bfd_byte *) thdr.sharedDebugRecordOffset);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->sharedDebugRecordCount,
		(bfd_byte *) thdr.sharedDebugRecordCount);
      put_word (abfd,
	   (bfd_vma) nlm_extended_header (abfd)->SharedInitializationOffset,
		(bfd_byte *) thdr.sharedInitializationOffset);
      put_word (abfd,
	    (bfd_vma) nlm_extended_header (abfd)->SharedExitProcedureOffset,
		(bfd_byte *) thdr.SharedExitProcedureOffset);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->productID,
		(bfd_byte *) thdr.productID);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->reserved0,
		(bfd_byte *) thdr.reserved0);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->reserved1,
		(bfd_byte *) thdr.reserved1);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->reserved2,
		(bfd_byte *) thdr.reserved2);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->reserved3,
		(bfd_byte *) thdr.reserved3);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->reserved4,
		(bfd_byte *) thdr.reserved4);
      put_word (abfd,
		(bfd_vma) nlm_extended_header (abfd)->reserved5,
		(bfd_byte *) thdr.reserved5);
      if (bfd_write ((PTR) & thdr, sizeof (thdr), 1, abfd) != sizeof (thdr))
	return false;
    }


  /* Write out the copyright header if there is one.  */
  if (find_nonzero ((PTR) nlm_copyright_header (abfd),
		    sizeof (Nlm_Internal_Copyright_Header)))
    {
      Nlm_External_Copyright_Header thdr;

      memcpy (thdr.stamp, "CoPyRiGhT=", 10);
      if (bfd_write ((PTR) thdr.stamp, sizeof (thdr.stamp), 1, abfd)
	  != sizeof (thdr.stamp))
	return false;
      thdr.copyrightMessageLength[0] =
	nlm_copyright_header (abfd)->copyrightMessageLength;
      if (bfd_write ((PTR) thdr.copyrightMessageLength, 1, 1, abfd) != 1)
	return false;
      /* The copyright message is a variable length string. */
      if (bfd_write ((PTR) nlm_copyright_header (abfd)->copyrightMessage,
		     nlm_copyright_header (abfd)->copyrightMessageLength + 1,
		     1, abfd) !=
	  ((bfd_size_type)
	   nlm_copyright_header (abfd)->copyrightMessageLength + 1))
	return false;
    }

  /* Write out the custom header if there is one.   */
  if (find_nonzero ((PTR) nlm_custom_header (abfd),
		    sizeof (Nlm_Internal_Custom_Header)))
    {
      Nlm_External_Custom_Header thdr;
      boolean ds;
      bfd_size_type hdrLength;

      ds = find_nonzero ((PTR) nlm_custom_header (abfd)->dataStamp,
			 sizeof (nlm_custom_header (abfd)->dataStamp));
      memcpy (thdr.stamp, "CuStHeAd", 8);
      hdrLength = (2 * NLM_TARGET_LONG_SIZE + (ds ? 8 : 0)
		   + nlm_custom_header (abfd)->hdrLength);
      put_word (abfd, hdrLength, thdr.length);
      put_word (abfd, (bfd_vma) nlm_custom_header (abfd)->dataOffset,
		thdr.dataOffset);
      put_word (abfd, (bfd_vma) nlm_custom_header (abfd)->dataLength,
		thdr.dataLength);
      if (! ds)
	{
	  BFD_ASSERT (nlm_custom_header (abfd)->hdrLength == 0);
	  if (bfd_write ((PTR) &thdr, 1,
			 sizeof (thdr) - sizeof (thdr.dataStamp), abfd)
	      != sizeof (thdr) - sizeof (thdr.dataStamp))
	    return false;
	}
      else
	{
	  memcpy (thdr.dataStamp, nlm_custom_header (abfd)->dataStamp,
		  sizeof (thdr.dataStamp));
	  if (bfd_write ((PTR) &thdr, sizeof (thdr), 1, abfd) != sizeof (thdr))
	    return false;
	  if (bfd_write (nlm_custom_header (abfd)->hdr, 1,
			 nlm_custom_header (abfd)->hdrLength, abfd)
	      != nlm_custom_header (abfd)->hdrLength)
	    return false;
	}
    }

  /* Write out the Cygnus debugging header if there is one.  */
  if (find_nonzero ((PTR) nlm_cygnus_ext_header (abfd),
		    sizeof (Nlm_Internal_Cygnus_Ext_Header)))
    {
      Nlm_External_Custom_Header thdr;

      memcpy (thdr.stamp, "CuStHeAd", 8);
      put_word (abfd, (bfd_vma) 2 * NLM_TARGET_LONG_SIZE + 8,
		(bfd_byte *) thdr.length);
      put_word (abfd, (bfd_vma) nlm_cygnus_ext_header (abfd)->offset,
		(bfd_byte *) thdr.dataOffset);
      put_word (abfd, (bfd_vma) nlm_cygnus_ext_header (abfd)->length,
		(bfd_byte *) thdr.dataLength);
      memcpy (thdr.dataStamp, "CyGnUsEx", 8);
      if (bfd_write ((PTR) &thdr, sizeof (thdr), 1, abfd) != sizeof (thdr))
	return false;
    }

  return true;
}

/* We read the NLM's public symbols and use it to generate a bfd symbol
   table (hey, it's better than nothing) on a one-for-one basis.  Thus
   use the number of public symbols as the number of bfd symbols we will
   have once we actually get around to reading them in.

   Return the number of bytes required to hold the symtab vector, based on
   the count plus 1, since we will NULL terminate the vector allocated based
   on this size. */

long
nlm_get_symtab_upper_bound (abfd)
     bfd *abfd;
{
  Nlm_Internal_Fixed_Header *i_fxdhdrp;	/* Nlm file header, internal form */
  long symcount;
  long symtab_size = 0;

  i_fxdhdrp = nlm_fixed_header (abfd);
  symcount = (i_fxdhdrp->numberOfPublics
	      + i_fxdhdrp->numberOfDebugRecords
	      + i_fxdhdrp->numberOfExternalReferences);
  symtab_size = (symcount + 1) * (sizeof (asymbol));
  return (symtab_size);
}

/* Note that bfd_get_symcount is guaranteed to be zero if slurping the
   symbol table fails. */

long
nlm_get_symtab (abfd, alocation)
     bfd *abfd;
     asymbol **alocation;
{
  nlm_symbol_type *symbase;
  bfd_size_type counter = 0;

  if (nlm_slurp_symbol_table (abfd) == false)
    return -1;
  symbase = nlm_get_symbols (abfd);
  while (counter < bfd_get_symcount (abfd))
    {
      *alocation++ = &symbase->symbol;
      symbase++;
      counter++;
    }
  *alocation = (asymbol *) NULL;
  return bfd_get_symcount (abfd);
}

/* Make an NLM symbol.  There is nothing special to do here.  */

asymbol *
nlm_make_empty_symbol (abfd)
     bfd *abfd;
{
  nlm_symbol_type *new;

  new = (nlm_symbol_type *) bfd_zalloc (abfd, sizeof (nlm_symbol_type));
  if (new)
    new->symbol.the_bfd = abfd;
  return &new->symbol;
}

/* Get symbol information.  */

void
nlm_get_symbol_info (ignore_abfd, symbol, ret)
     bfd *ignore_abfd;
     asymbol *symbol;
     symbol_info *ret;
{
  bfd_symbol_info (symbol, ret);
}

/* Print symbol information.  */

void
nlm_print_symbol (abfd, afile, symbol, how)
     bfd *abfd;
     PTR afile;
     asymbol *symbol;
     bfd_print_symbol_type how;
{
  FILE *file = (FILE *) afile;

  switch (how)
    {
    case bfd_print_symbol_name:
    case bfd_print_symbol_more:
      if (symbol->name)
	fprintf (file, "%s", symbol->name);
      break;
    case bfd_print_symbol_all:
      bfd_print_symbol_vandf ((PTR) file, symbol);
      fprintf (file, " %-5s", symbol->section->name);
      if (symbol->name)
	fprintf (file, " %s", symbol->name);
      break;
    }
}

/* Slurp in nlm symbol table.

   In the external (in-file) form, NLM export records are variable length,
   with the following form:

	1 byte		length of the symbol name (N)
	N bytes		the symbol name
	4 bytes		the symbol offset from start of it's section

   We also read in the debugging symbols and import records.  Import
   records are treated as undefined symbols.  As we read the import
   records we also read in the associated reloc information, which is
   attached to the symbol.

   The bfd symbols are copied to SYMPTRS.

   When we return, the bfd symcount is either zero or contains the correct
   number of symbols.
*/

static boolean
nlm_slurp_symbol_table (abfd)
     bfd *abfd;
{
  Nlm_Internal_Fixed_Header *i_fxdhdrp;	/* Nlm file header, internal form */
  bfd_size_type totsymcount;	/* Number of NLM symbols */
  bfd_size_type symcount;	/* Counter of NLM symbols */
  nlm_symbol_type *sym;		/* Pointer to current bfd symbol */
  unsigned char symlength;	/* Symbol length read into here */
  unsigned char symtype;	/* Type of debugging symbol */
  bfd_byte temp[NLM_TARGET_LONG_SIZE];	/* Symbol offsets read into here */
  boolean (*read_import_func) PARAMS ((bfd *, nlm_symbol_type *));
  boolean (*set_public_section_func) PARAMS ((bfd *, nlm_symbol_type *));

  if (nlm_get_symbols (abfd) != NULL)
    return (true);

  /* Read each raw NLM symbol, using the information to create a canonical bfd
     symbol table entry.

     Note that we allocate the initial bfd canonical symbol buffer based on a
     one-to-one mapping of the NLM symbols to canonical symbols.  We actually
     use all the NLM symbols, so there will be no space left over at the end.
     When we have all the symbols, we build the caller's pointer vector. */

  abfd->symcount = 0;
  i_fxdhdrp = nlm_fixed_header (abfd);
  totsymcount = (i_fxdhdrp->numberOfPublics
		 + i_fxdhdrp->numberOfDebugRecords
		 + i_fxdhdrp->numberOfExternalReferences);
  if (totsymcount == 0)
    {
      return (true);
    }

  if (bfd_seek (abfd, i_fxdhdrp->publicsOffset, SEEK_SET) == -1)
    return (false);

  sym = ((nlm_symbol_type *)
	 bfd_zalloc (abfd, totsymcount * sizeof (nlm_symbol_type)));
  if (!sym)
    return false;
  nlm_set_symbols (abfd, sym);

  /* We use the bfd's symcount directly as the control count, so that early
     termination of the loop leaves the symcount correct for the symbols that
     were read. */

  set_public_section_func = nlm_set_public_section_func (abfd);
  symcount = i_fxdhdrp->numberOfPublics;
  while (abfd->symcount < symcount)
    {
      if (bfd_read ((PTR) & symlength, sizeof (symlength), 1, abfd)
	  != sizeof (symlength))
	return (false);
      sym->symbol.the_bfd = abfd;
      sym->symbol.name = bfd_alloc (abfd, symlength + 1);
      if (!sym->symbol.name)
	return false;
      if (bfd_read ((PTR) sym->symbol.name, symlength, 1, abfd)
	  != symlength)
	return (false);
      /* Cast away const.  */
      ((char *) (sym->symbol.name))[symlength] = '\0';
      if (bfd_read ((PTR) temp, sizeof (temp), 1, abfd) != sizeof (temp))
	return (false);
      sym->symbol.flags = BSF_GLOBAL | BSF_EXPORT;
      sym->symbol.value = get_word (abfd, temp);
      if (set_public_section_func)
	{
	  /* Most backends can use the code below, but unfortunately
	     some use a different scheme.  */
	  if ((*set_public_section_func) (abfd, sym) == false)
	    return false;
	}
      else
	{
	  if (sym->symbol.value & NLM_HIBIT)
	    {
	      sym->symbol.value &= ~NLM_HIBIT;
	      sym->symbol.flags |= BSF_FUNCTION;
	      sym->symbol.section =
		bfd_get_section_by_name (abfd, NLM_CODE_NAME);
	    }
	  else
	    {
	      sym->symbol.section =
		bfd_get_section_by_name (abfd, NLM_INITIALIZED_DATA_NAME);
	    }
	}
      sym->rcnt = 0;
      abfd->symcount++;
      sym++;
    }

  /* Read the debugging records.  */

  if (i_fxdhdrp->numberOfDebugRecords > 0)
    {
      if (bfd_seek (abfd, i_fxdhdrp->debugInfoOffset, SEEK_SET) == -1)
	return (false);

      symcount += i_fxdhdrp->numberOfDebugRecords;
      while (abfd->symcount < symcount)
	{
	  if ((bfd_read ((PTR) & symtype, sizeof (symtype), 1, abfd)
	       != sizeof (symtype))
	   || bfd_read ((PTR) temp, sizeof (temp), 1, abfd) != sizeof (temp)
	      || (bfd_read ((PTR) & symlength, sizeof (symlength), 1, abfd)
		  != sizeof (symlength)))
	    return false;
	  sym->symbol.the_bfd = abfd;
	  sym->symbol.name = bfd_alloc (abfd, symlength + 1);
	  if (!sym->symbol.name)
	    return false;
	  if (bfd_read ((PTR) sym->symbol.name, symlength, 1, abfd)
	      != symlength)
	    return (false);
	  /* Cast away const.  */
	  ((char *) (sym->symbol.name))[symlength] = '\0';
	  sym->symbol.flags = BSF_LOCAL;
	  sym->symbol.value = get_word (abfd, temp);
	  if (symtype == 0)
	    {
	      sym->symbol.section =
		bfd_get_section_by_name (abfd, NLM_INITIALIZED_DATA_NAME);
	    }
	  else if (symtype == 1)
	    {
	      sym->symbol.flags |= BSF_FUNCTION;
	      sym->symbol.section =
		bfd_get_section_by_name (abfd, NLM_CODE_NAME);
	    }
	  else
	    {
	      sym->symbol.section = bfd_abs_section_ptr;
	    }
	  sym->rcnt = 0;
	  abfd->symcount++;
	  sym++;
	}
    }

  /* Read in the import records.  We can only do this if we know how
     to read relocs for this target.  */

  read_import_func = nlm_read_import_func (abfd);
  if (read_import_func != NULL)
    {
      if (bfd_seek (abfd, i_fxdhdrp->externalReferencesOffset, SEEK_SET)
	  == -1)
	return (false);

      symcount += i_fxdhdrp->numberOfExternalReferences;
      while (abfd->symcount < symcount)
	{
	  if ((*read_import_func) (abfd, sym) == false)
	    return false;
	  sym++;
	  abfd->symcount++;
	}
    }

  return (true);
}

/* Get the relocs for an NLM file.  There are two types of relocs.
   Imports are relocs against symbols defined in other NLM files.  We
   treat these as relocs against global symbols.  Relocation fixups
   are internal relocs.

   The actual format used to store the relocs is machine specific.  */

/* Read in the relocation fixup information.  This is stored in
   nlm_relocation_fixups, an array of arelent structures, and
   nlm_relocation_fixup_secs, an array of section pointers.  The
   section pointers are needed because the relocs are not sorted by
   section.  */

static boolean
nlm_slurp_reloc_fixups (abfd)
     bfd *abfd;
{
  boolean (*read_func) PARAMS ((bfd *, nlm_symbol_type *, asection **,
				arelent *));
  bfd_size_type count;
  arelent *rels;
  asection **secs;

  if (nlm_relocation_fixups (abfd) != NULL)
    return true;
  read_func = nlm_read_reloc_func (abfd);
  if (read_func == NULL)
    return true;

  if (bfd_seek (abfd, nlm_fixed_header (abfd)->relocationFixupOffset,
		SEEK_SET) != 0)
    return false;

  count = nlm_fixed_header (abfd)->numberOfRelocationFixups;
  rels = (arelent *) bfd_alloc (abfd, count * sizeof (arelent));
  secs = (asection **) bfd_alloc (abfd, count * sizeof (asection *));
  if ((rels == NULL || secs == NULL) && count != 0)
    return false;
  nlm_relocation_fixups (abfd) = rels;
  nlm_relocation_fixup_secs (abfd) = secs;

  /* We have to read piece by piece, because we don't know how large
     the machine specific reloc information is.  */
  while (count-- != 0)
    {
      if ((*read_func) (abfd, (nlm_symbol_type *) NULL, secs, rels) == false)
	{
	  nlm_relocation_fixups (abfd) = NULL;
	  nlm_relocation_fixup_secs (abfd) = NULL;
	  return false;
	}
      ++secs;
      ++rels;
    }

  return true;
}

/* Get the number of relocs.  This really just returns an upper bound,
   since it does not attempt to distinguish them based on the section.
   That will be handled when they are actually read.  */

long
nlm_get_reloc_upper_bound (abfd, sec)
     bfd *abfd;
     asection *sec;
{
  nlm_symbol_type *syms;
  bfd_size_type count;
  unsigned int ret;

  /* If we don't know how to read relocs, just return 0.  */
  if (nlm_read_reloc_func (abfd) == NULL)
    return -1;
  /* Make sure we have either the code or the data section.  */
  if ((bfd_get_section_flags (abfd, sec) & (SEC_CODE | SEC_DATA)) == 0)
    return 0;

  syms = nlm_get_symbols (abfd);
  if (syms == NULL)
    {
      if (nlm_slurp_symbol_table (abfd) == false)
	return -1;
      syms = nlm_get_symbols (abfd);
    }

  ret = nlm_fixed_header (abfd)->numberOfRelocationFixups;

  count = bfd_get_symcount (abfd);
  while (count-- != 0)
    {
      ret += syms->rcnt;
      ++syms;
    }

  return (ret + 1) * sizeof (arelent *);
}

/* Get the relocs themselves.  */

long
nlm_canonicalize_reloc (abfd, sec, relptr, symbols)
     bfd *abfd;
     asection *sec;
     arelent **relptr;
     asymbol **symbols;
{
  arelent *rels;
  asection **secs;
  bfd_size_type count, i;
  unsigned int ret;

  /* Get the relocation fixups.  */
  rels = nlm_relocation_fixups (abfd);
  if (rels == NULL)
    {
      if (nlm_slurp_reloc_fixups (abfd) == false)
	return -1;
      rels = nlm_relocation_fixups (abfd);
    }
  secs = nlm_relocation_fixup_secs (abfd);

  ret = 0;
  count = nlm_fixed_header (abfd)->numberOfRelocationFixups;
  for (i = 0; i < count; i++, rels++, secs++)
    {
      if (*secs == sec)
	{
	  *relptr++ = rels;
	  ++ret;
	}
    }

  /* Get the import symbols.  */
  count = bfd_get_symcount (abfd);
  for (i = 0; i < count; i++, symbols++)
    {
      asymbol *sym;

      sym = *symbols;
      if (bfd_asymbol_flavour (sym) == bfd_target_nlm_flavour)
	{
	  nlm_symbol_type *nlm_sym;
	  bfd_size_type j;

	  nlm_sym = (nlm_symbol_type *) sym;
	  for (j = 0; j < nlm_sym->rcnt; j++)
	    {
	      if (nlm_sym->relocs[j].section == sec)
		{
		  *relptr = &nlm_sym->relocs[j].reloc;
		  (*relptr)->sym_ptr_ptr = symbols;
		  ++relptr;
		  ++ret;
		}
	    }
	}
    }

  *relptr = NULL;

  return ret;
}

/* Compute the section file positions for an NLM file.  All variable
   length data in the file headers must be set before this function is
   called.  If the variable length data is changed later, the
   resulting object file will be incorrect.  Unfortunately, there is
   no way to check this.

   This routine also sets the Size and Offset fields in the fixed
   header.

   It also looks over the symbols and moves any common symbols into
   the .bss section; NLM has no way to represent a common symbol.
   This approach means that either the symbols must already have been
   set at this point, or there must be no common symbols.  We need to
   move the symbols at this point so that mangle_relocs can see the
   final values.  */

static boolean
nlm_compute_section_file_positions (abfd)
     bfd *abfd;
{
  file_ptr sofar;
  asection *sec;
  bfd_vma text, data, bss;
  bfd_vma text_low, data_low;
  unsigned int text_align, data_align, other_align;
  file_ptr text_ptr, data_ptr, other_ptr;
  asection *bss_sec;
  asymbol **sym_ptr_ptr;

  if (abfd->output_has_begun == true)
    return true;

  /* Make sure we have a section to hold uninitialized data.  */
  bss_sec = bfd_get_section_by_name (abfd, NLM_UNINITIALIZED_DATA_NAME);
  if (bss_sec == NULL)
    {
      if (!add_bfd_section (abfd, NLM_UNINITIALIZED_DATA_NAME,
			    (file_ptr) 0, (bfd_size_type) 0,
			    SEC_ALLOC))
	return false;
      bss_sec = bfd_get_section_by_name (abfd, NLM_UNINITIALIZED_DATA_NAME);
    }

  abfd->output_has_begun = true;

  /* The fixed header.  */
  sofar = nlm_optional_prefix_size (abfd) + nlm_fixed_header_size (abfd);

  /* The variable header.  */
  sofar += (sizeof (nlm_variable_header (abfd)->descriptionLength)
	    + nlm_variable_header (abfd)->descriptionLength + 1
	    + NLM_TARGET_LONG_SIZE	/* stackSize */
	    + NLM_TARGET_LONG_SIZE	/* reserved */
	    + sizeof (nlm_variable_header (abfd)->oldThreadName)
	    + sizeof (nlm_variable_header (abfd)->screenNameLength)
	    + nlm_variable_header (abfd)->screenNameLength + 1
	    + sizeof (nlm_variable_header (abfd)->threadNameLength)
	    + nlm_variable_header (abfd)->threadNameLength + 1);

  /* The auxiliary headers.  */
  if (find_nonzero ((PTR) nlm_version_header (abfd),
		    sizeof (Nlm_Internal_Version_Header)))
    sofar += sizeof (Nlm_External_Version_Header);
  if (find_nonzero ((PTR) nlm_extended_header (abfd),
		    sizeof (Nlm_Internal_Extended_Header)))
    sofar += sizeof (Nlm_External_Extended_Header);
  if (find_nonzero ((PTR) nlm_copyright_header (abfd),
		    sizeof (Nlm_Internal_Copyright_Header)))
    sofar += (sizeof (Nlm_External_Copyright_Header)
	      + nlm_copyright_header (abfd)->copyrightMessageLength + 1);
  if (find_nonzero ((PTR) nlm_custom_header (abfd),
		    sizeof (Nlm_Internal_Custom_Header)))
    sofar += (sizeof (Nlm_External_Custom_Header)
	      + nlm_custom_header (abfd)->hdrLength);
  if (find_nonzero ((PTR) nlm_cygnus_ext_header (abfd),
		    sizeof (Nlm_Internal_Cygnus_Ext_Header)))
    sofar += sizeof (Nlm_External_Custom_Header);

  /* Compute the section file positions in two passes.  First get the
     sizes of the text and data sections, and then set the file
     positions.  This code aligns the sections in the file using the
     same alignment restrictions that apply to the sections in memory;
     this may not be necessary.  */
  text = 0;
  text_low = (bfd_vma) - 1;
  text_align = 0;
  data = 0;
  data_low = (bfd_vma) - 1;
  data_align = 0;
  bss = 0;
  other_align = 0;
  for (sec = abfd->sections; sec != (asection *) NULL; sec = sec->next)
    {
      flagword f;

      sec->_raw_size = BFD_ALIGN (sec->_raw_size, 1 << sec->alignment_power);

      f = bfd_get_section_flags (abfd, sec);
      if (f & SEC_CODE)
	{
	  text += sec->_raw_size;
	  if (bfd_get_section_vma (abfd, sec) < text_low)
	    text_low = bfd_get_section_vma (abfd, sec);
	  if (sec->alignment_power > text_align)
	    text_align = sec->alignment_power;
	}
      else if (f & SEC_DATA)
	{
	  data += sec->_raw_size;
	  if (bfd_get_section_vma (abfd, sec) < data_low)
	    data_low = bfd_get_section_vma (abfd, sec);
	  if (sec->alignment_power > data_align)
	    data_align = sec->alignment_power;
	}
      else if (f & SEC_HAS_CONTENTS)
	{
	  if (sec->alignment_power > other_align)
	    other_align = sec->alignment_power;
	}
      else if (f & SEC_ALLOC)
	bss += sec->_raw_size;
    }

  nlm_set_text_low (abfd, text_low);
  nlm_set_data_low (abfd, data_low);

  if (nlm_no_uninitialized_data (abfd))
    {
      /* This NetWare format does not use uninitialized data.  We must
	 increase the size of the data section.  We will never wind up
	 writing those file locations, so they will remain zero.  */
      data += bss;
      bss = 0;
    }

  text_ptr = BFD_ALIGN (sofar, 1 << text_align);
  data_ptr = BFD_ALIGN (text_ptr + text, 1 << data_align);
  other_ptr = BFD_ALIGN (data_ptr + data, 1 << other_align);

  /* Fill in some fields in the header for which we now have the
     information.  */
  nlm_fixed_header (abfd)->codeImageOffset = text_ptr;
  nlm_fixed_header (abfd)->codeImageSize = text;
  nlm_fixed_header (abfd)->dataImageOffset = data_ptr;
  nlm_fixed_header (abfd)->dataImageSize = data;
  nlm_fixed_header (abfd)->uninitializedDataSize = bss;

  for (sec = abfd->sections; sec != (asection *) NULL; sec = sec->next)
    {
      flagword f;

      f = bfd_get_section_flags (abfd, sec);

      if (f & SEC_CODE)
	{
	  sec->filepos = text_ptr;
	  text_ptr += sec->_raw_size;
	}
      else if (f & SEC_DATA)
	{
	  sec->filepos = data_ptr;
	  data_ptr += sec->_raw_size;
	}
      else if (f & SEC_HAS_CONTENTS)
	{
	  sec->filepos = other_ptr;
	  other_ptr += sec->_raw_size;
	}
    }

  nlm_fixed_header (abfd)->relocationFixupOffset = other_ptr;

  /* Move all common symbols into the .bss section.  */

  sym_ptr_ptr = bfd_get_outsymbols (abfd);
  if (sym_ptr_ptr != NULL)
    {
      asymbol **sym_end;
      bfd_vma add;

      sym_end = sym_ptr_ptr + bfd_get_symcount (abfd);
      add = 0;
      for (; sym_ptr_ptr < sym_end; sym_ptr_ptr++)
	{
	  asymbol *sym;
	  bfd_vma size;

	  sym = *sym_ptr_ptr;

	  if (!bfd_is_com_section (bfd_get_section (sym)))
	    continue;

	  /* Put the common symbol in the .bss section, and increase
	     the size of the .bss section by the size of the common
	     symbol (which is the old value of the symbol).  */
	  sym->section = bss_sec;
	  size = sym->value;
	  sym->value = bss_sec->_raw_size + add;
	  add += size;
	  add = BFD_ALIGN (add, 1 << bss_sec->alignment_power);
	}
      if (add != 0)
	{
	  if (nlm_no_uninitialized_data (abfd))
	    {
	      /* We could handle this case, but so far it hasn't been
		 necessary.  */
	      abort ();
	    }
	  nlm_fixed_header (abfd)->uninitializedDataSize += add;
	  bss_sec->_raw_size += add;
	}
    }

  return true;
}

/* Set the contents of a section.  To do this we need to know where
   the section is going to be located in the output file.  That means
   that the sizes of all the sections must be set, and all the
   variable size header information must be known.  */

boolean
nlm_set_section_contents (abfd, section, location, offset, count)
     bfd *abfd;
     asection *section;
     PTR location;
     file_ptr offset;
     bfd_size_type count;
{
  if (abfd->output_has_begun == false
      && nlm_compute_section_file_positions (abfd) == false)
    return false;

  if (count == 0)
    return true;

  /* i386 NetWare has a very restricted set of relocs.  In order for
     objcopy to work, the NLM i386 backend needs a chance to rework
     the section contents so that its set of relocs will work.  If all
     the relocs are already acceptable, this will not do anything.  */
  if (section->reloc_count != 0)
    {
      boolean (*mangle_relocs_func) PARAMS ((bfd *, asection *, PTR,
					     bfd_vma, bfd_size_type));

      mangle_relocs_func = nlm_mangle_relocs_func (abfd);
      if (mangle_relocs_func != NULL)
	{
	  if (!(*mangle_relocs_func) (abfd, section, location,
				      (bfd_vma) offset, count))
	    return false;
	}
    }

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

  return true;
}

/* We need to sort a list of relocs associated with sections when we
   write out the external relocs.  */

static int
nlm_external_reloc_compare (p1, p2)
     const void *p1;
     const void *p2;
{
  const struct reloc_and_sec *r1 = (const struct reloc_and_sec *) p1;
  const struct reloc_and_sec *r2 = (const struct reloc_and_sec *) p2;
  int cmp;

  cmp = strcmp ((*r1->rel->sym_ptr_ptr)->name,
		(*r2->rel->sym_ptr_ptr)->name);
  if (cmp != 0)
    return cmp;

  /* We sort by address within symbol to make the sort more stable and
     increase the chances that different hosts will generate bit for
     bit equivalent results.  */
  return (int) (r1->rel->address - r2->rel->address);
}

/* Write out an NLM file.  We write out the information in this order:
     fixed header
     variable header
     auxiliary headers
     code sections
     data sections
     other sections (custom data, messages, help, shared NLM, RPC,
     		     module dependencies)
     relocation fixups
     external references (imports)
     public symbols (exports)
     debugging records
   This is similar to the order used by the NetWare tools; the
   difference is that NetWare puts the sections other than code, data
   and custom data at the end of the NLM.  It is convenient for us to
   know where the sections are going to be before worrying about the
   size of the other information.

   By the time this function is called, all the section data should
   have been output using set_section_contents.  Note that custom
   data, the message file, the help file, the shared NLM file, the RPC
   data, and the module dependencies are all considered to be
   sections; the caller is responsible for filling in the offset and
   length fields in the NLM headers.  The relocation fixups and
   imports are both obtained from the list of relocs attached to each
   section.  The exports and debugging records are obtained from the
   list of outsymbols.  */

boolean
nlm_write_object_contents (abfd)
     bfd *abfd;
{
  asection *sec;
  boolean (*write_import_func) PARAMS ((bfd *, asection *, arelent *));
  bfd_size_type external_reloc_count, internal_reloc_count, i, c;
  struct reloc_and_sec *external_relocs;
  asymbol **sym_ptr_ptr;
  file_ptr last;
  boolean (*write_prefix_func) PARAMS ((bfd *));
  unsigned char *fixed_header = NULL;

  fixed_header = ((unsigned char *)
		  bfd_malloc ((size_t) nlm_fixed_header_size (abfd)));
  if (fixed_header == NULL)
    goto error_return;

  if (abfd->output_has_begun == false
      && nlm_compute_section_file_positions (abfd) == false)
    goto error_return;

  /* Write out the variable length headers.  */
  if (bfd_seek (abfd,
	     nlm_optional_prefix_size (abfd) + nlm_fixed_header_size (abfd),
		SEEK_SET) != 0)
    goto error_return;
  if (nlm_swap_variable_header_out (abfd) == false
      || nlm_swap_auxiliary_headers_out (abfd) == false)
    {
      bfd_set_error (bfd_error_system_call);
      goto error_return;
    }

  /* A weak check on whether the section file positions were
     reasonable.  */
  if (bfd_tell (abfd) > nlm_fixed_header (abfd)->codeImageOffset)
    {
      bfd_set_error (bfd_error_invalid_operation);
      goto error_return;
    }

  /* Advance to the relocs.  */
  if (bfd_seek (abfd, nlm_fixed_header (abfd)->relocationFixupOffset,
		SEEK_SET) != 0)
    goto error_return;

  /* The format of the relocation entries is dependent upon the
     particular target.  We use an external routine to write the reloc
     out.  */
  write_import_func = nlm_write_import_func (abfd);

  /* Write out the internal relocation fixups.  While we're looping
     over the relocs, we also count the external relocs, which is
     needed when they are written out below.  */
  internal_reloc_count = 0;
  external_reloc_count = 0;
  for (sec = abfd->sections; sec != (asection *) NULL; sec = sec->next)
    {
      arelent **rel_ptr_ptr, **rel_end;

      if (sec->reloc_count == 0)
	continue;

      /* We can only represent relocs within a code or data
	 section.  We ignore them for a debugging section.  */
      if ((bfd_get_section_flags (abfd, sec) & (SEC_CODE | SEC_DATA)) == 0)
	continue;

      /* We need to know how to write out imports */
      if (write_import_func == NULL)
	{
	  bfd_set_error (bfd_error_invalid_operation);
	  goto error_return;
	}

      rel_ptr_ptr = sec->orelocation;
      rel_end = rel_ptr_ptr + sec->reloc_count;
      for (; rel_ptr_ptr < rel_end; rel_ptr_ptr++)
	{
	  arelent *rel;
	  asymbol *sym;

	  rel = *rel_ptr_ptr;
	  sym = *rel->sym_ptr_ptr;

	  if (! bfd_is_und_section (bfd_get_section (sym)))
	    {
	      ++internal_reloc_count;
	      if ((*write_import_func) (abfd, sec, rel) == false)
		goto error_return;
	    }
	  else
	    ++external_reloc_count;
	}
    }
  nlm_fixed_header (abfd)->numberOfRelocationFixups = internal_reloc_count;

  /* Write out the imports (relocs against external symbols).  These
     are output as a symbol name followed by all the relocs for that
     symbol, so we must first gather together all the relocs against
     external symbols and sort them.  */
  external_relocs =
    (struct reloc_and_sec *) bfd_alloc (abfd,
					(external_reloc_count
					 * sizeof (struct reloc_and_sec)));
  if (external_relocs == (struct reloc_and_sec *) NULL)
    goto error_return;
  i = 0;
  for (sec = abfd->sections; sec != (asection *) NULL; sec = sec->next)
    {
      arelent **rel_ptr_ptr, **rel_end;

      if (sec->reloc_count == 0)
	continue;

      rel_ptr_ptr = sec->orelocation;
      rel_end = rel_ptr_ptr + sec->reloc_count;
      for (; rel_ptr_ptr < rel_end; rel_ptr_ptr++)
	{
	  arelent *rel;
	  asymbol *sym;

	  rel = *rel_ptr_ptr;
	  sym = *rel->sym_ptr_ptr;

	  if (! bfd_is_und_section (bfd_get_section (sym)))
	    continue;

	  external_relocs[i].rel = rel;
	  external_relocs[i].sec = sec;
	  ++i;
	}
    }

  BFD_ASSERT (i == external_reloc_count);

  /* Sort the external relocs by name.  */
  qsort ((PTR) external_relocs, (size_t) external_reloc_count,
	 sizeof (struct reloc_and_sec), nlm_external_reloc_compare);

  /* Write out the external relocs.  */
  nlm_fixed_header (abfd)->externalReferencesOffset = bfd_tell (abfd);
  c = 0;
  i = 0;
  while (i < external_reloc_count)
    {
      arelent *rel;
      asymbol *sym;
      bfd_size_type j, cnt;

      ++c;

      rel = external_relocs[i].rel;
      sym = *rel->sym_ptr_ptr;

      cnt = 0;
      for (j = i;
	   (j < external_reloc_count
	    && *external_relocs[j].rel->sym_ptr_ptr == sym);
	   j++)
	++cnt;

      if ((*nlm_write_external_func (abfd)) (abfd, cnt, sym,
					     &external_relocs[i])
	  == false)
	goto error_return;

      i += cnt;
    }

  nlm_fixed_header (abfd)->numberOfExternalReferences = c;

  /* Write out the public symbols (exports).  */
  sym_ptr_ptr = bfd_get_outsymbols (abfd);
  if (sym_ptr_ptr != (asymbol **) NULL)
    {
      bfd_vma (*get_public_offset_func) PARAMS ((bfd *, asymbol *));
      boolean (*write_export_func) PARAMS ((bfd *, asymbol *, bfd_vma));

      asymbol **sym_end;

      nlm_fixed_header (abfd)->publicsOffset = bfd_tell (abfd);
      get_public_offset_func = nlm_get_public_offset_func (abfd);
      write_export_func = nlm_write_export_func (abfd);
      c = 0;
      sym_end = sym_ptr_ptr + bfd_get_symcount (abfd);
      for (; sym_ptr_ptr < sym_end; sym_ptr_ptr++)
	{
	  asymbol *sym;
	  bfd_byte len;
	  bfd_vma offset;
	  bfd_byte temp[NLM_TARGET_LONG_SIZE];

	  sym = *sym_ptr_ptr;

	  if ((sym->flags & (BSF_EXPORT | BSF_GLOBAL)) == 0
	      || bfd_is_und_section (bfd_get_section (sym)))
	    continue;

	  ++c;

	  if (get_public_offset_func)
	    {
	      /* Most backends can use the code below, but
		 unfortunately some use a different scheme.  */
	      offset = (*get_public_offset_func) (abfd, sym);
	    }
	  else
	    {
	      offset = bfd_asymbol_value (sym);
	      sec = sym->section;
	      if (sec->flags & SEC_CODE)
		{
		  offset -= nlm_get_text_low (abfd);
		  offset |= NLM_HIBIT;
		}
	      else if (sec->flags & (SEC_DATA | SEC_ALLOC))
		{
		  /* SEC_ALLOC is for the .bss section.  */
		  offset -= nlm_get_data_low (abfd);
		}
	      else
		{
		  /* We can't handle an exported symbol that is not in
		     the code or data segment.  */
		  bfd_set_error (bfd_error_invalid_operation);
		  goto error_return;
		}
	    }

	  if (write_export_func)
	    {
	      if ((*write_export_func) (abfd, sym, offset) == false)
		goto error_return;
	    }
	  else
	    {
	      len = strlen (sym->name);
	      if ((bfd_write (&len, sizeof (bfd_byte), 1, abfd)
		   != sizeof (bfd_byte))
		  || bfd_write (sym->name, len, 1, abfd) != len)
		goto error_return;

	      put_word (abfd, offset, temp);
	      if (bfd_write (temp, sizeof (temp), 1, abfd) != sizeof (temp))
		goto error_return;
	    }
	}
      nlm_fixed_header (abfd)->numberOfPublics = c;

      /* Write out the debugging records.  The NLM conversion program
	 wants to be able to inhibit this, so as a special hack if
	 debugInfoOffset is set to -1 we don't write any debugging
	 information.  This can not be handled by fiddling with the
	 symbol table, because exported symbols appear in both the
	 exported symbol list and the debugging information.  */
      if (nlm_fixed_header (abfd)->debugInfoOffset == (file_ptr) - 1)
	{
	  nlm_fixed_header (abfd)->debugInfoOffset = 0;
	  nlm_fixed_header (abfd)->numberOfDebugRecords = 0;
	}
      else
	{
	  nlm_fixed_header (abfd)->debugInfoOffset = bfd_tell (abfd);
	  c = 0;
	  sym_ptr_ptr = bfd_get_outsymbols (abfd);
	  sym_end = sym_ptr_ptr + bfd_get_symcount (abfd);
	  for (; sym_ptr_ptr < sym_end; sym_ptr_ptr++)
	    {
	      asymbol *sym;
	      bfd_byte type, len;
	      bfd_vma offset;
	      bfd_byte temp[NLM_TARGET_LONG_SIZE];

	      sym = *sym_ptr_ptr;

	      /* The NLM notion of a debugging symbol is actually what
		 BFD calls a local or global symbol.  What BFD calls a
		 debugging symbol NLM does not understand at all.  */
	      if ((sym->flags & (BSF_LOCAL | BSF_GLOBAL | BSF_EXPORT)) == 0
		  || (sym->flags & BSF_DEBUGGING) != 0
		  || bfd_is_und_section (bfd_get_section (sym)))
		continue;

	      ++c;

	      offset = bfd_asymbol_value (sym);
	      sec = sym->section;
	      if (sec->flags & SEC_CODE)
		{
		  offset -= nlm_get_text_low (abfd);
		  type = 1;
		}
	      else if (sec->flags & (SEC_DATA | SEC_ALLOC))
		{
		  /* SEC_ALLOC is for the .bss section.  */
		  offset -= nlm_get_data_low (abfd);
		  type = 0;
		}
	      else
		type = 2;

	      /* The type is 0 for data, 1 for code, 2 for absolute.  */
	      if (bfd_write (&type, sizeof (bfd_byte), 1, abfd)
		  != sizeof (bfd_byte))
		goto error_return;

	      put_word (abfd, offset, temp);
	      if (bfd_write (temp, sizeof (temp), 1, abfd) != sizeof (temp))
		goto error_return;

	      len = strlen (sym->name);
	      if ((bfd_write (&len, sizeof (bfd_byte), 1, abfd)
		   != sizeof (bfd_byte))
		  || bfd_write (sym->name, len, 1, abfd) != len)
		goto error_return;
	    }
	  nlm_fixed_header (abfd)->numberOfDebugRecords = c;
	}
    }

  /* NLMLINK fills in offset values even if there is no data, so we do
     the same.  */
  last = bfd_tell (abfd);
  if (nlm_fixed_header (abfd)->codeImageOffset == 0)
    nlm_fixed_header (abfd)->codeImageOffset = last;
  if (nlm_fixed_header (abfd)->dataImageOffset == 0)
    nlm_fixed_header (abfd)->dataImageOffset = last;
  if (nlm_fixed_header (abfd)->customDataOffset == 0)
    nlm_fixed_header (abfd)->customDataOffset = last;
  if (nlm_fixed_header (abfd)->moduleDependencyOffset == 0)
    nlm_fixed_header (abfd)->moduleDependencyOffset = last;
  if (nlm_fixed_header (abfd)->relocationFixupOffset == 0)
    nlm_fixed_header (abfd)->relocationFixupOffset = last;
  if (nlm_fixed_header (abfd)->externalReferencesOffset == 0)
    nlm_fixed_header (abfd)->externalReferencesOffset = last;
  if (nlm_fixed_header (abfd)->publicsOffset == 0)
    nlm_fixed_header (abfd)->publicsOffset = last;
  if (nlm_fixed_header (abfd)->debugInfoOffset == 0)
    nlm_fixed_header (abfd)->debugInfoOffset = last;

  /* At this point everything has been written out except the fixed
     header.  */
  memcpy (nlm_fixed_header (abfd)->signature, nlm_signature (abfd),
	  NLM_SIGNATURE_SIZE);
  nlm_fixed_header (abfd)->version = NLM_HEADER_VERSION;
  nlm_fixed_header (abfd)->codeStartOffset =
    (bfd_get_start_address (abfd)
     - nlm_get_text_low (abfd));

  /* We have no convenient way for the caller to pass in the exit
     procedure or the check unload procedure, so the caller must set
     the values in the header to the values of the symbols.  */
  nlm_fixed_header (abfd)->exitProcedureOffset -= nlm_get_text_low (abfd);
  if (nlm_fixed_header (abfd)->checkUnloadProcedureOffset != 0)
    nlm_fixed_header (abfd)->checkUnloadProcedureOffset -=
      nlm_get_text_low (abfd);

  if (bfd_seek (abfd, 0, SEEK_SET) != 0)
    goto error_return;

  write_prefix_func = nlm_write_prefix_func (abfd);
  if (write_prefix_func)
    {
      if ((*write_prefix_func) (abfd) == false)
	goto error_return;
    }

  BFD_ASSERT ((bfd_size_type) bfd_tell (abfd)
	      == nlm_optional_prefix_size (abfd));

  nlm_swap_fixed_header_out (abfd, nlm_fixed_header (abfd), fixed_header);
  if (bfd_write (fixed_header, nlm_fixed_header_size (abfd), 1, abfd)
      != nlm_fixed_header_size (abfd))
    goto error_return;

  if (fixed_header != NULL)
    free (fixed_header);
  return true;

error_return:
  if (fixed_header != NULL)
    free (fixed_header);
  return false;
}