aboutsummaryrefslogtreecommitdiff
path: root/gas/config/obj-macho.c
blob: 77442810ca15803d8bffc28efb33c10734ba91ed (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
/* Mach-O object file format
   Copyright (C) 2009-2021 Free Software Foundation, Inc.

   This file is part of GAS, the GNU Assembler.

   GAS 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 3,
   or (at your option) any later version.

   GAS 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 GAS; see the file COPYING.  If not, write to the Free
   Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
   02110-1301, USA.  */

/* Here we handle the mach-o directives that are common to all architectures.

   Most significant are mach-o named sections and a variety of symbol type
   decorations.  */

/* Mach-O supports multiple, named segments each of which may contain
   multiple named sections.  Thus the concept of subsectioning is
   handled by (say) having a __TEXT segment with appropriate flags from
   which subsections are generated like __text, __const etc.

   The well-known as short-hand section switch directives like .text, .data
   etc. are mapped onto predefined segment/section pairs using facilities
   supplied by the mach-o port of bfd.

   A number of additional mach-o short-hand section switch directives are
   also defined.  */

#define OBJ_HEADER "obj-macho.h"

#include "as.h"
#include "subsegs.h"
#include "symbols.h"
#include "write.h"
#include "mach-o.h"
#include "mach-o/loader.h"
#include "obj-macho.h"

#include <string.h>

/* Forward decls.  */
static segT obj_mach_o_segT_from_bfd_name (const char *, int);

/* TODO: Implement "-dynamic"/"-static" command line options.  */

static int obj_mach_o_is_static;

/* TODO: Implement the "-n" command line option to suppress the initial
   switch to the text segment.  */

static int obj_mach_o_start_with_text_section = 1;

/* Allow for special re-ordering on output.  */

static int obj_mach_o_seen_objc_section;

/* Start-up: At present, just create the sections we want.  */
void
mach_o_begin (void)
{
  /* Mach-O only defines the .text section by default, and even this can
     be suppressed by a flag.  In the latter event, the first code MUST
     be a section definition.  */
  if (obj_mach_o_start_with_text_section)
    {
      text_section = obj_mach_o_segT_from_bfd_name (TEXT_SECTION_NAME, 1);
      subseg_set (text_section, 0);
      if (obj_mach_o_is_static)
	{
	  bfd_mach_o_section *mo_sec
			= bfd_mach_o_get_mach_o_section (text_section);
	  mo_sec->flags &= ~BFD_MACH_O_S_ATTR_PURE_INSTRUCTIONS;
	}
    }
}

/* Remember the subsections_by_symbols state in case we need to reset
   the file flags.  */

static int obj_mach_o_subsections_by_symbols;

/* This will put at most 16 characters (terminated by a ',' or newline) from
   the input stream into dest.  If there are more than 16 chars before the
   delimiter, a warning is given and the string is truncated.  On completion of
   this function, input_line_pointer will point to the char after the ',' or
   to the newline.

   It trims leading and trailing space.  */

static int
collect_16char_name (char *dest, const char *msg, int require_comma)
{
  char c, *namstart;

  SKIP_WHITESPACE ();
  namstart = input_line_pointer;

  while ( (c = *input_line_pointer) != ','
	 && !is_end_of_line[(unsigned char) c])
    input_line_pointer++;

  {
      int len = input_line_pointer - namstart; /* could be zero.  */
      /* lose any trailing space.  */
      while (len > 0 && namstart[len-1] == ' ')
        len--;
      if (len > 16)
        {
          *input_line_pointer = '\0'; /* make a temp string.  */
	  as_bad (_("the %s name '%s' is too long (maximum 16 characters)"),
		     msg, namstart);
	  *input_line_pointer = c; /* restore for printing.  */
	  len = 16;
	}
      if (len > 0)
        memcpy (dest, namstart, len);
  }

  if (c != ',' && require_comma)
    {
      as_bad (_("expected a %s name followed by a `,'"), msg);
      return 1;
    }

  return 0;
}

static int
obj_mach_o_get_section_names (char *seg, char *sec,
			      unsigned segl, unsigned secl)
{
  /* Zero-length segment and section names are allowed.  */
  /* Parse segment name.  */
  memset (seg, 0, segl);
  if (collect_16char_name (seg, "segment", 1))
    {
      ignore_rest_of_line ();
      return 0;
    }
  input_line_pointer++; /* Skip the terminating ',' */

  /* Parse section name, which can be empty.  */
  memset (sec, 0, secl);
  collect_16char_name (sec, "section", 0);
  return 1;
}

/* Build (or get) a section from the mach-o description - which includes
   optional definitions for type, attributes, alignment and stub size.

   BFD supplies default values for sections which have a canonical name.  */

#define SECT_TYPE_SPECIFIED 0x0001
#define SECT_ATTR_SPECIFIED 0x0002
#define SECT_ALGN_SPECIFIED 0x0004
#define SECT_STUB_SPECIFIED 0x0008

static segT
obj_mach_o_make_or_get_sect (char * segname, char * sectname,
			     unsigned int specified_mask,
			     unsigned int usectype, unsigned int usecattr,
			     unsigned int ualign, offsetT stub_size)
{
  unsigned int sectype, secattr, secalign;
  flagword oldflags, flags;
  const char *name;
  segT sec;
  bfd_mach_o_section *msect;
  const mach_o_section_name_xlat *xlat;

  /* This provides default bfd flags and default mach-o section type and
     attributes along with the canonical name.  */
  xlat = bfd_mach_o_section_data_for_mach_sect (stdoutput, segname, sectname);

  /* TODO: more checking of whether overrides are actually allowed.  */

  if (xlat != NULL)
    {
      name = xstrdup (xlat->bfd_name);
      sectype = xlat->macho_sectype;
      if (specified_mask & SECT_TYPE_SPECIFIED)
	{
	  if ((sectype == BFD_MACH_O_S_ZEROFILL
	       || sectype == BFD_MACH_O_S_GB_ZEROFILL)
	      && sectype != usectype)
	    as_bad (_("cannot override zerofill section type for `%s,%s'"),
		    segname, sectname);
	  else
	    sectype = usectype;
	}
      secattr = xlat->macho_secattr;
      secalign = xlat->sectalign;
      flags = xlat->bfd_flags;
    }
  else
    {
      /* There is no normal BFD section name for this section.  Create one.
         The name created doesn't really matter as it will never be written
         on disk.  */
      name = concat (segname, ".", sectname, (char *) NULL);
      if (specified_mask & SECT_TYPE_SPECIFIED)
	sectype = usectype;
      else
	sectype = BFD_MACH_O_S_REGULAR;
      secattr = BFD_MACH_O_S_ATTR_NONE;
      secalign = 0;
      flags = SEC_NO_FLAGS;
    }

  /* For now, just use what the user provided.  */

  if (specified_mask & SECT_ATTR_SPECIFIED)
    secattr = usecattr;

  if (specified_mask & SECT_ALGN_SPECIFIED)
    secalign = ualign;

  /* Sub-segments don't exists as is on Mach-O.  */
  sec = subseg_new (name, 0);

  oldflags = bfd_section_flags (sec);
  msect = bfd_mach_o_get_mach_o_section (sec);

  if (oldflags == SEC_NO_FLAGS)
    {
      /* In the absence of canonical information, try to determine CODE and
	 DEBUG section flags from the mach-o section data.  */
      if (flags == SEC_NO_FLAGS
	  && (specified_mask & SECT_ATTR_SPECIFIED)
	  && (secattr & BFD_MACH_O_S_ATTR_PURE_INSTRUCTIONS))
	flags |= SEC_CODE;

      if (flags == SEC_NO_FLAGS
	  && (specified_mask & SECT_ATTR_SPECIFIED)
	  && (secattr & BFD_MACH_O_S_ATTR_DEBUG))
	flags |= SEC_DEBUGGING;

      /* New, so just use the defaults or what's specified.  */
      if (!bfd_set_section_flags (sec, flags))
	as_warn (_("failed to set flags for \"%s\": %s"),
		 bfd_section_name (sec),
		 bfd_errmsg (bfd_get_error ()));

      strncpy (msect->segname, segname, BFD_MACH_O_SEGNAME_SIZE);
      msect->segname[BFD_MACH_O_SEGNAME_SIZE] = 0;
      strncpy (msect->sectname, sectname, BFD_MACH_O_SECTNAME_SIZE);
      msect->sectname[BFD_MACH_O_SECTNAME_SIZE] = 0;

      msect->align = secalign;
      msect->flags = sectype | secattr;

      if (sectype == BFD_MACH_O_S_ZEROFILL
	  || sectype == BFD_MACH_O_S_GB_ZEROFILL)
        seg_info (sec)->bss = 1;
    }
  else if (flags != SEC_NO_FLAGS)
    {
      if (flags != oldflags
	  || msect->flags != (secattr | sectype))
	as_warn (_("Ignoring changed section attributes for %s"), name);
    }

  if (specified_mask & SECT_STUB_SPECIFIED)
    /* At present, the stub size is not supplied from the BFD tables.  */
    msect->reserved2 = stub_size;

  return sec;
}

/* .section

   The '.section' specification syntax looks like:
   .section <segment> , <section> [, type [, attribs [, size]]]

   White space is allowed everywhere between elements.

   <segment> and <section> may be from 0 to 16 chars in length - they may
   contain spaces but leading and trailing space will be trimmed.  It is
   mandatory that they be present (or that zero-length names are indicated
   by ",,").

   There is only a single section type for any entry.

   There may be multiple attributes, they are delimited by `+'.

   Not all section types and attributes are accepted by the Darwin system
   assemblers as user-specifiable - although, at present, we do here.  */

static void
obj_mach_o_section (int ignore ATTRIBUTE_UNUSED)
{
  unsigned int sectype = BFD_MACH_O_S_REGULAR;
  unsigned int specified_mask = 0;
  unsigned int secattr = 0;
  offsetT sizeof_stub = 0;
  segT new_seg;
  char segname[17];
  char sectname[17];

#ifdef md_flush_pending_output
  md_flush_pending_output ();
#endif

  /* Get the User's segment and section names.  */
  if (! obj_mach_o_get_section_names (segname, sectname, 17, 17))
    return;

  /* Parse section type, if present.  */
  if (*input_line_pointer == ',')
    {
      char *p;
      char c;
      char tmpc;
      int len;
      input_line_pointer++;
      SKIP_WHITESPACE ();
      p = input_line_pointer;
      while ((c = *input_line_pointer) != ','
	      && !is_end_of_line[(unsigned char) c])
	input_line_pointer++;

      len = input_line_pointer - p;
      /* strip trailing spaces.  */
      while (len > 0 && p[len-1] == ' ')
	len--;
      tmpc = p[len];

      /* Temporarily make a string from the token.  */
      p[len] = 0;
      sectype = bfd_mach_o_get_section_type_from_name (stdoutput, p);
      if (sectype > 255) /* Max Section ID == 255.  */
        {
          as_bad (_("unknown or invalid section type '%s'"), p);
	  p[len] = tmpc;
	  ignore_rest_of_line ();
	  return;
        }
      else
	specified_mask |= SECT_TYPE_SPECIFIED;
      /* Restore.  */
      p[len] = tmpc;

      /* Parse attributes.
	 TODO: check validity of attributes for section type.  */
      if ((specified_mask & SECT_TYPE_SPECIFIED)
	  && c == ',')
        {
          do
            {
              int attr;

	      /* Skip initial `,' and subsequent `+'.  */
              input_line_pointer++;
	      SKIP_WHITESPACE ();
	      p = input_line_pointer;
	      while ((c = *input_line_pointer) != '+'
		      && c != ','
		      && !is_end_of_line[(unsigned char) c])
		input_line_pointer++;

	      len = input_line_pointer - p;
	      /* strip trailing spaces.  */
	      while (len > 0 && p[len-1] == ' ')
		len--;
	      tmpc = p[len];

	      /* Temporarily make a string from the token.  */
	      p[len] ='\0';
              attr = bfd_mach_o_get_section_attribute_from_name (p);
	      if (attr == -1)
		{
                  as_bad (_("unknown or invalid section attribute '%s'"), p);
		  p[len] = tmpc;
		  ignore_rest_of_line ();
		  return;
                }
              else
		{
		  specified_mask |= SECT_ATTR_SPECIFIED;
                  secattr |= attr;
		}
	      /* Restore.  */
	      p[len] = tmpc;
            }
          while (*input_line_pointer == '+');

          /* Parse sizeof_stub.  */
          if ((specified_mask & SECT_ATTR_SPECIFIED)
	      && *input_line_pointer == ',')
            {
              if (sectype != BFD_MACH_O_S_SYMBOL_STUBS)
                {
		  as_bad (_("unexpected section size information"));
		  ignore_rest_of_line ();
		  return;
		}

	      input_line_pointer++;
              sizeof_stub = get_absolute_expression ();
              specified_mask |= SECT_STUB_SPECIFIED;
            }
          else if ((specified_mask & SECT_ATTR_SPECIFIED)
		   && sectype == BFD_MACH_O_S_SYMBOL_STUBS)
            {
              as_bad (_("missing sizeof_stub expression"));
	      ignore_rest_of_line ();
	      return;
            }
        }
    }

  new_seg = obj_mach_o_make_or_get_sect (segname, sectname, specified_mask,
					 sectype, secattr, 0 /*align */,
					 sizeof_stub);
  if (new_seg != NULL)
    {
      subseg_set (new_seg, 0);
      demand_empty_rest_of_line ();
    }
}

/* .zerofill segname, sectname [, symbolname, size [, align]]

   Zerofill switches, temporarily, to a sect of type 'zerofill'.

   If a variable name is given, it defines that in the section.
   Otherwise it just creates the section if it doesn't exist.  */

static void
obj_mach_o_zerofill (int ignore ATTRIBUTE_UNUSED)
{
  char segname[17];
  char sectname[17];
  segT old_seg = now_seg;
  segT new_seg;
  symbolS *sym = NULL;
  unsigned int align = 0;
  unsigned int specified_mask = 0;
  offsetT size = 0;

#ifdef md_flush_pending_output
  md_flush_pending_output ();
#endif

  /* Get the User's segment and section names.  */
  if (! obj_mach_o_get_section_names (segname, sectname, 17, 17))
    return;

  /* Parse variable definition, if present.  */
  if (*input_line_pointer == ',')
    {
      /* Parse symbol, size [.align]
         We follow the method of s_common_internal, with the difference
         that the symbol cannot be a duplicate-common.  */
      char *name;
      char c;
      char *p;
      expressionS exp;

      input_line_pointer++; /* Skip ',' */
      SKIP_WHITESPACE ();
      c = get_symbol_name (&name);
      /* Just after name is now '\0'.  */
      p = input_line_pointer;
      *p = c;

      if (name == p)
	{
	  as_bad (_("expected symbol name"));
	  ignore_rest_of_line ();
	  goto done;
	}

      SKIP_WHITESPACE_AFTER_NAME ();
      if (*input_line_pointer == ',')
	input_line_pointer++;

      expression_and_evaluate (&exp);
      if (exp.X_op != O_constant
	  && exp.X_op != O_absent)
	{
	    as_bad (_("bad or irreducible absolute expression"));
	  ignore_rest_of_line ();
	  goto done;
	}
      else if (exp.X_op == O_absent)
	{
	  as_bad (_("missing size expression"));
	  ignore_rest_of_line ();
	  goto done;
	}

      size = exp.X_add_number;
      size &= ((valueT) 2 << (stdoutput->arch_info->bits_per_address - 1)) - 1;
      if (exp.X_add_number != size || !exp.X_unsigned)
	{
	  as_warn (_("size (%ld) out of range, ignored"),
		   (long) exp.X_add_number);
	  ignore_rest_of_line ();
	  goto done;
	}

     *p = 0; /* Make the name into a c string for err messages.  */
     sym = symbol_find_or_make (name);
     if (S_IS_DEFINED (sym) || symbol_equated_p (sym))
	{
	  as_bad (_("symbol `%s' is already defined"), name);
	  *p = c;
	  ignore_rest_of_line ();
	   goto done;
	}

      size = S_GET_VALUE (sym);
      if (size == 0)
	size = exp.X_add_number;
      else if (size != exp.X_add_number)
	as_warn (_("size of \"%s\" is already %ld; not changing to %ld"),
		   name, (long) size, (long) exp.X_add_number);

      *p = c;  /* Restore the termination char.  */

      SKIP_WHITESPACE ();
      if (*input_line_pointer == ',')
	{
	  align = (unsigned int) parse_align (0);
	  if (align == (unsigned int) -1)
	    {
	      as_warn (_("align value not recognized, using size"));
	      align = size;
	    }
	  if (align > 15)
	    {
	      as_warn (_("Alignment (%lu) too large: 15 assumed."),
			(unsigned long)align);
	      align = 15;
	    }
	  specified_mask |= SECT_ALGN_SPECIFIED;
	}
    }
 /* else just a section definition.  */

  specified_mask |= SECT_TYPE_SPECIFIED;
  new_seg = obj_mach_o_make_or_get_sect (segname, sectname, specified_mask,
					 BFD_MACH_O_S_ZEROFILL,
					 BFD_MACH_O_S_ATTR_NONE,
					 align, (offsetT) 0 /*stub size*/);
  if (new_seg == NULL)
    return;

  /* In case the user specifies the bss section by mach-o name.
     Create it on demand */
  if (strcmp (new_seg->name, BSS_SECTION_NAME) == 0
      && bss_section == NULL)
    bss_section = new_seg;

  subseg_set (new_seg, 0);

  if (sym != NULL)
    {
      char *pfrag;

      if (align)
	{
	  record_alignment (new_seg, align);
	  frag_align (align, 0, 0);
	}

      /* Detach from old frag.  */
      if (S_GET_SEGMENT (sym) == new_seg)
	symbol_get_frag (sym)->fr_symbol = NULL;

      symbol_set_frag (sym, frag_now);
      pfrag = frag_var (rs_org, 1, 1, 0, sym, size, NULL);
      *pfrag = 0;

      S_SET_SEGMENT (sym, new_seg);
      if (new_seg == bss_section)
	S_CLEAR_EXTERNAL (sym);
    }

 done:
  /* switch back to the section that was current before the .zerofill.  */
  subseg_set (old_seg, 0);
}

static segT
obj_mach_o_segT_from_bfd_name (const char *nam, int must_succeed)
{
  const mach_o_section_name_xlat *xlat;
  const char *segn;
  segT sec;

  /* BFD has tables of flags and default attributes for all the sections that
     have a 'canonical' name.  */
  xlat = bfd_mach_o_section_data_for_bfd_name (stdoutput, nam, &segn);
  if (xlat == NULL)
    {
      if (must_succeed)
	as_fatal (_("BFD is out of sync with GAS, "
		     "unhandled well-known section type `%s'"), nam);
      return NULL;
    }

  sec = bfd_get_section_by_name (stdoutput, nam);
  if (sec == NULL)
    {
      bfd_mach_o_section *msect;

      sec = subseg_force_new (xlat->bfd_name, 0);

      /* Set default type, attributes and alignment.  */
      msect = bfd_mach_o_get_mach_o_section (sec);
      msect->flags = xlat->macho_sectype | xlat->macho_secattr;
      msect->align = xlat->sectalign;

      if ((msect->flags & BFD_MACH_O_SECTION_TYPE_MASK)
	  == BFD_MACH_O_S_ZEROFILL)
	seg_info (sec)->bss = 1;
    }

  return sec;
}

static const char * const known_sections[] =
{
  /*  0 */ NULL,
  /* __TEXT */
  /*  1 */ ".const",
  /*  2 */ ".static_const",
  /*  3 */ ".cstring",
  /*  4 */ ".literal4",
  /*  5 */ ".literal8",
  /*  6 */ ".literal16",
  /*  7 */ ".constructor",
  /*  8 */ ".destructor",
  /*  9 */ ".eh_frame",
  /* __DATA */
  /* 10 */ ".const_data",
  /* 11 */ ".static_data",
  /* 12 */ ".mod_init_func",
  /* 13 */ ".mod_term_func",
  /* 14 */ ".dyld",
  /* 15 */ ".cfstring"
};

/* Interface for a known non-optional section directive.  */

static void
obj_mach_o_known_section (int sect_index)
{
  segT section;

#ifdef md_flush_pending_output
  md_flush_pending_output ();
#endif

  section = obj_mach_o_segT_from_bfd_name (known_sections[sect_index], 1);
  if (section != NULL)
    subseg_set (section, 0);

  /* else, we leave the section as it was; there was a fatal error anyway.  */
}

static const char * const objc_sections[] =
{
  /*  0 */ NULL,
  /*  1 */ ".objc_class",
  /*  2 */ ".objc_meta_class",
  /*  3 */ ".objc_cat_cls_meth",
  /*  4 */ ".objc_cat_inst_meth",
  /*  5 */ ".objc_protocol",
  /*  6 */ ".objc_string_object",
  /*  7 */ ".objc_cls_meth",
  /*  8 */ ".objc_inst_meth",
  /*  9 */ ".objc_cls_refs",
  /* 10 */ ".objc_message_refs",
  /* 11 */ ".objc_symbols",
  /* 12 */ ".objc_category",
  /* 13 */ ".objc_class_vars",
  /* 14 */ ".objc_instance_vars",
  /* 15 */ ".objc_module_info",
  /* 16 */ ".cstring", /* objc_class_names Alias for .cstring */
  /* 17 */ ".cstring", /* Alias objc_meth_var_types for .cstring */
  /* 18 */ ".cstring", /* objc_meth_var_names Alias for .cstring */
  /* 19 */ ".objc_selector_strs",
  /* 20 */ ".objc_image_info", /* extension.  */
  /* 21 */ ".objc_selector_fixup", /* extension.  */
  /* 22 */ ".objc1_class_ext", /* ObjC-1 extension.  */
  /* 23 */ ".objc1_property_list", /* ObjC-1 extension.  */
  /* 24 */ ".objc1_protocol_ext" /* ObjC-1 extension.  */
};

/* This currently does the same as known_sections, but kept separate for
   ease of maintenance.  */

static void
obj_mach_o_objc_section (int sect_index)
{
  segT section;

#ifdef md_flush_pending_output
  md_flush_pending_output ();
#endif

  section = obj_mach_o_segT_from_bfd_name (objc_sections[sect_index], 1);
  if (section != NULL)
    {
      obj_mach_o_seen_objc_section = 1; /* We need to ensure that certain
					   sections are present and in the
					   right order.  */
      subseg_set (section, 0);
    }

  /* else, we leave the section as it was; there was a fatal error anyway.  */
}

/* Debug section directives.  */

static const char * const debug_sections[] =
{
  /*  0 */ NULL,
  /* __DWARF */
  /*  1 */ ".debug_frame",
  /*  2 */ ".debug_info",
  /*  3 */ ".debug_abbrev",
  /*  4 */ ".debug_aranges",
  /*  5 */ ".debug_macinfo",
  /*  6 */ ".debug_line",
  /*  7 */ ".debug_loc",
  /*  8 */ ".debug_pubnames",
  /*  9 */ ".debug_pubtypes",
  /* 10 */ ".debug_str",
  /* 11 */ ".debug_ranges",
  /* 12 */ ".debug_macro"
};

/* ??? Maybe these should be conditional on gdwarf-*.
   It`s also likely that we will need to be able to set them from the cfi
   code.  */

static void
obj_mach_o_debug_section (int sect_index)
{
  segT section;

#ifdef md_flush_pending_output
  md_flush_pending_output ();
#endif

  section = obj_mach_o_segT_from_bfd_name (debug_sections[sect_index], 1);
  if (section != NULL)
    subseg_set (section, 0);

  /* else, we leave the section as it was; there was a fatal error anyway.  */
}

/* This could be moved to the tc-xx files, but there is so little dependency
   there, that the code might as well be shared.  */

struct opt_tgt_sect
{
 const char *name;
 unsigned x86_val;
 unsigned ppc_val;
};

/* The extensions here are for specific sections that are generated by GCC
   and Darwin system tools, but don't have directives in the `system as'.  */

static const struct opt_tgt_sect tgt_sections[] =
{
  /*  0 */ { NULL, 0, 0},
  /*  1 */ { ".lazy_symbol_pointer", 0, 0},
  /*  2 */ { ".lazy_symbol_pointer2", 0, 0}, /* X86 - extension */
  /*  3 */ { ".lazy_symbol_pointer3", 0, 0}, /* X86 - extension */
  /*  4 */ { ".non_lazy_symbol_pointer", 0, 0},
  /*  5 */ { ".non_lazy_symbol_pointer_x86", 0, 0}, /* X86 - extension */
  /*  6 */ { ".symbol_stub", 16, 20},
  /*  7 */ { ".symbol_stub1", 0, 16}, /* PPC - extension */
  /*  8 */ { ".picsymbol_stub", 26, 36},
  /*  9 */ { ".picsymbol_stub1", 0, 32}, /* PPC - extension */
  /* 10 */ { ".picsymbol_stub2", 25, 0}, /* X86 - extension */
  /* 11 */ { ".picsymbol_stub3", 5, 0}, /* X86 - extension  */
};

/* Interface for an optional section directive.  */

static void
obj_mach_o_opt_tgt_section (int sect_index)
{
  const struct opt_tgt_sect *tgtsct = &tgt_sections[sect_index];
  segT section;

#ifdef md_flush_pending_output
  md_flush_pending_output ();
#endif

  section = obj_mach_o_segT_from_bfd_name (tgtsct->name, 0);
  if (section == NULL)
    {
      as_bad (_("%s is not used for the selected target"), tgtsct->name);
      /* Leave the section as it is.  */
    }
  else
    {
      bfd_mach_o_section *mo_sec = bfd_mach_o_get_mach_o_section (section);
      subseg_set (section, 0);
#if defined (TC_I386)
      mo_sec->reserved2 = tgtsct->x86_val;
#elif defined (TC_PPC)
      mo_sec->reserved2 = tgtsct->ppc_val;
#else
      mo_sec->reserved2 = 0;
#endif
    }
}

/* We don't necessarily have the three 'base' sections on mach-o.
   Normally, we would start up with only the 'text' section defined.
   However, even that can be suppressed with (TODO) c/l option "-n".
   Thus, we have to be able to create all three sections on-demand.  */

static void
obj_mach_o_base_section (int sect_index)
{
  segT section;

#ifdef md_flush_pending_output
  md_flush_pending_output ();
#endif

  /* We don't support numeric (or any other) qualifications on the
     well-known section shorthands.  */
  demand_empty_rest_of_line ();

  switch (sect_index)
    {
      /* Handle the three sections that are globally known within GAS.
	 For Mach-O, these are created on demand rather than at startup.  */
      case 1:
	if (text_section == NULL)
	  text_section = obj_mach_o_segT_from_bfd_name (TEXT_SECTION_NAME, 1);
	if (obj_mach_o_is_static)
	  {
	    bfd_mach_o_section *mo_sec
		= bfd_mach_o_get_mach_o_section (text_section);
	    mo_sec->flags &= ~BFD_MACH_O_S_ATTR_PURE_INSTRUCTIONS;
	  }
	section = text_section;
	break;
      case 2:
	if (data_section == NULL)
	  data_section = obj_mach_o_segT_from_bfd_name (DATA_SECTION_NAME, 1);
	section = data_section;
	break;
      case 3:
        /* ??? maybe this achieves very little, as an addition.  */
	if (bss_section == NULL)
	  {
	    bss_section = obj_mach_o_segT_from_bfd_name (BSS_SECTION_NAME, 1);
	    seg_info (bss_section)->bss = 1;
	  }
	section = bss_section;
	break;
      default:
        as_fatal (_("internal error: base section index out of range"));
        return;
	break;
    }
  subseg_set (section, 0);
}

/* This finishes off parsing a .comm or .lcomm statement, which both can have
   an (optional) alignment field.  It also allows us to create the bss section
   on demand.  */

static symbolS *
obj_mach_o_common_parse (int is_local, symbolS *symbolP,
			 addressT size)
{
  addressT align = 0;
  bfd_mach_o_asymbol *s;

  SKIP_WHITESPACE ();

  /* Both comm and lcomm take an optional alignment, as a power
     of two between 1 and 15.  */
  if (*input_line_pointer == ',')
    {
      /* We expect a power of 2.  */
      align = parse_align (0);
      if (align == (addressT) -1)
	return NULL;
      if (align > 15)
	{
	  as_warn (_("Alignment (%lu) too large: 15 assumed."),
		  (unsigned long)align);
	  align = 15;
	}
    }

  s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (symbolP);
  if (is_local)
    {
      /* Create the BSS section on demand.  */
      if (bss_section == NULL)
	{
	  bss_section = obj_mach_o_segT_from_bfd_name (BSS_SECTION_NAME, 1);
	  seg_info (bss_section)->bss = 1;
	}
      bss_alloc (symbolP, size, align);
      s->n_type = BFD_MACH_O_N_SECT;
      S_CLEAR_EXTERNAL (symbolP);
    }
  else
    {
      S_SET_VALUE (symbolP, size);
      S_SET_ALIGN (symbolP, align);
      S_SET_EXTERNAL (symbolP);
      S_SET_SEGMENT (symbolP, bfd_com_section_ptr);
      s->n_type = BFD_MACH_O_N_UNDF | BFD_MACH_O_N_EXT;
    }

  /* This is a data object (whatever we choose that to mean).  */
  s->symbol.flags |= BSF_OBJECT;

  /* We've set symbol qualifiers, so validate if you can.  */
  s->symbol.udata.i = SYM_MACHO_FIELDS_NOT_VALIDATED;

  return symbolP;
}

static void
obj_mach_o_comm (int is_local)
{
  s_comm_internal (is_local, obj_mach_o_common_parse);
}

/* Set properties that apply to the whole file.  At present, the only
   one defined, is subsections_via_symbols.  */

typedef enum obj_mach_o_file_properties {
  OBJ_MACH_O_FILE_PROP_NONE = 0,
  OBJ_MACH_O_FILE_PROP_SUBSECTS_VIA_SYMS,
  OBJ_MACH_O_FILE_PROP_MAX
} obj_mach_o_file_properties;

static void
obj_mach_o_fileprop (int prop)
{
  if (prop < 0 || prop >= OBJ_MACH_O_FILE_PROP_MAX)
    as_fatal (_("internal error: bad file property ID %d"), prop);

  switch ((obj_mach_o_file_properties) prop)
    {
      case OBJ_MACH_O_FILE_PROP_SUBSECTS_VIA_SYMS:
        obj_mach_o_subsections_by_symbols = 1;
	if (!bfd_set_private_flags (stdoutput,
				    BFD_MACH_O_MH_SUBSECTIONS_VIA_SYMBOLS))
	  as_bad (_("failed to set subsections by symbols"));
	demand_empty_rest_of_line ();
	break;
      default:
	break;
    }
}

/* Temporary markers for symbol reference data.
   Lazy will remain in place.  */
#define LAZY 0x01
#define REFE 0x02

/* We have a bunch of qualifiers that may be applied to symbols.
   .globl is handled here so that we might make sure that conflicting qualifiers
   are caught where possible.  */

typedef enum obj_mach_o_symbol_type {
  OBJ_MACH_O_SYM_UNK = 0,
  OBJ_MACH_O_SYM_LOCAL = 1,
  OBJ_MACH_O_SYM_GLOBL = 2,
  OBJ_MACH_O_SYM_REFERENCE = 3,
  OBJ_MACH_O_SYM_WEAK_REF = 4,
  OBJ_MACH_O_SYM_LAZY_REF = 5,
  OBJ_MACH_O_SYM_WEAK_DEF = 6,
  OBJ_MACH_O_SYM_PRIV_EXT = 7,
  OBJ_MACH_O_SYM_NO_DEAD_STRIP = 8,
  OBJ_MACH_O_SYM_WEAK = 9
} obj_mach_o_symbol_type;

/* Set Mach-O-specific symbol qualifiers. */

static int
obj_mach_o_set_symbol_qualifier (symbolS *sym, int type)
{
  int is_defined;
  bfd_mach_o_asymbol *s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (sym);
  bfd_mach_o_section *sec;
  int sectype = -1;

  /* If the symbol is defined, then we can do more rigorous checking on
     the validity of the qualifiers.  Otherwise, we are stuck with waiting
     until it's defined - or until write the file.

     In certain cases (e.g. when a symbol qualifier is intended to introduce
     an undefined symbol in a stubs section) we should check that the current
     section is appropriate to the qualifier.  */

  is_defined = s->symbol.section != bfd_und_section_ptr;
  if (is_defined)
    sec = bfd_mach_o_get_mach_o_section (s->symbol.section) ;
  else
    sec = bfd_mach_o_get_mach_o_section (now_seg) ;

  if (sec != NULL)
    sectype = sec->flags & BFD_MACH_O_SECTION_TYPE_MASK;

  switch ((obj_mach_o_symbol_type) type)
    {
      case OBJ_MACH_O_SYM_LOCAL:
	/* This is an extension over the system tools.  */
        if (s->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT))
	  {
	    as_bad (_("'%s' previously declared as '%s'."), s->symbol.name,
		      (s->n_type & BFD_MACH_O_N_PEXT) ? "private extern"
						      : "global" );
	    s->symbol.udata.i = SYM_MACHO_FIELDS_UNSET;
	    return 1;
	  }
	else
	  {
	    s->n_type &= ~BFD_MACH_O_N_EXT;
	    S_CLEAR_EXTERNAL (sym);
	  }
	break;

      case OBJ_MACH_O_SYM_PRIV_EXT:
	s->n_type |= BFD_MACH_O_N_PEXT ;
	s->n_desc &= ~LAZY; /* The native tool switches this off too.  */
	/* We follow the system tools in marking PEXT as also global.  */
	/* Fall through.  */

      case OBJ_MACH_O_SYM_GLOBL:
	/* It's not an error to define a symbol and then make it global.  */
	s->n_type |= BFD_MACH_O_N_EXT;
	S_SET_EXTERNAL (sym);
	break;

      case OBJ_MACH_O_SYM_REFERENCE:
        if (is_defined)
          s->n_desc |= BFD_MACH_O_N_NO_DEAD_STRIP;
        else
          s->n_desc |= (REFE | BFD_MACH_O_N_NO_DEAD_STRIP);
	break;

      case OBJ_MACH_O_SYM_LAZY_REF:
        if (is_defined)
          s->n_desc |= BFD_MACH_O_N_NO_DEAD_STRIP;
        else
          s->n_desc |= (REFE | LAZY | BFD_MACH_O_N_NO_DEAD_STRIP);
	break;

      /* Force ld to retain the symbol - even if it appears unused.  */
      case OBJ_MACH_O_SYM_NO_DEAD_STRIP:
	s->n_desc |= BFD_MACH_O_N_NO_DEAD_STRIP ;
	break;

      /* Mach-O's idea of weak ...  */
      case OBJ_MACH_O_SYM_WEAK_REF:
	s->n_desc |= BFD_MACH_O_N_WEAK_REF ;
	break;

      case OBJ_MACH_O_SYM_WEAK_DEF:
	if (is_defined && sectype != BFD_MACH_O_S_COALESCED)
	  {
	    as_bad (_("'%s' can't be a weak_definition (currently only"
		      " supported in sections of type coalesced)"),
		      s->symbol.name);
	    s->symbol.udata.i = SYM_MACHO_FIELDS_UNSET;
	    return 1;
	  }
	else
	  s->n_desc |= BFD_MACH_O_N_WEAK_DEF;
	break;

      case OBJ_MACH_O_SYM_WEAK:
        /* A generic 'weak' - we try to figure out what it means at
	   symbol frob time.  */
	S_SET_WEAK (sym);
	break;

      default:
	break;
    }

    /* We've seen some kind of qualifier - check validity if or when the entity
     is defined.  */
  s->symbol.udata.i = SYM_MACHO_FIELDS_NOT_VALIDATED;
  return 0;
}

/* Respond to symbol qualifiers.
   All of the form:
   .<qualifier> symbol [, symbol]*
   a list of symbols is an extension over the Darwin system as.  */

static void
obj_mach_o_sym_qual (int ntype)
{
  char *name;
  char c;
  symbolS *symbolP;

#ifdef md_flush_pending_output
  md_flush_pending_output ();
#endif

  do
    {
      c = get_symbol_name (&name);
      symbolP = symbol_find_or_make (name);
      obj_mach_o_set_symbol_qualifier (symbolP, ntype);
      *input_line_pointer = c;
      SKIP_WHITESPACE_AFTER_NAME ();
      c = *input_line_pointer;
      if (c == ',')
	{
	  input_line_pointer++;
	  SKIP_WHITESPACE ();
	  if (is_end_of_line[(unsigned char) *input_line_pointer])
	    c = '\n';
	}
    }
  while (c == ',');

  demand_empty_rest_of_line ();
}

typedef struct obj_mach_o_indirect_sym
{
  symbolS *sym;
  segT sect;
  struct obj_mach_o_indirect_sym *next;
} obj_mach_o_indirect_sym;

/* We store in order an maintain a pointer to the last one - to save reversing
   later.  */
obj_mach_o_indirect_sym *indirect_syms;
obj_mach_o_indirect_sym *indirect_syms_tail;

static void
obj_mach_o_indirect_symbol (int arg ATTRIBUTE_UNUSED)
{
  bfd_mach_o_section *sec = bfd_mach_o_get_mach_o_section (now_seg);

#ifdef md_flush_pending_output
  md_flush_pending_output ();
#endif

  if (obj_mach_o_is_static)
    as_bad (_("use of .indirect_symbols requires `-dynamic'"));

  switch (sec->flags & BFD_MACH_O_SECTION_TYPE_MASK)
    {
      case BFD_MACH_O_S_SYMBOL_STUBS:
      case BFD_MACH_O_S_LAZY_SYMBOL_POINTERS:
      case BFD_MACH_O_S_NON_LAZY_SYMBOL_POINTERS:
        {
          obj_mach_o_indirect_sym *isym;
	  char *name;
	  char c = get_symbol_name (&name);
	  symbolS *sym = symbol_find_or_make (name);
	  unsigned int elsize =
			bfd_mach_o_section_get_entry_size (stdoutput, sec);

	  if (elsize == 0)
	    {
	      as_bad (_("attempt to add an indirect_symbol to a stub or"
			" reference section with a zero-sized element at %s"),
			name);
	      (void) restore_line_pointer (c);
	      ignore_rest_of_line ();
	      return;
	    }
	  (void) restore_line_pointer (c);

	  /* The indirect symbols are validated after the symbol table is
	     frozen, we must make sure that if a local symbol is used as an
	     indirect, it is promoted to a 'real' one.  Fetching the bfd sym
	     achieves this.  */
	  symbol_get_bfdsym (sym);
	  isym = XNEW (obj_mach_o_indirect_sym);

	  /* Just record the data for now, we will validate it when we
	     compute the output in obj_mach_o_set_indirect_symbols.  */
	  isym->sym = sym;
	  isym->sect = now_seg;
	  isym->next = NULL;
	  if (indirect_syms == NULL)
	    indirect_syms = isym;
	  else
	    indirect_syms_tail->next = isym;
	  indirect_syms_tail = isym;
	}
        break;

      default:
	as_bad (_("an .indirect_symbol must be in a symbol pointer"
		  " or stub section."));
	ignore_rest_of_line ();
	return;
    }
  demand_empty_rest_of_line ();
}

const pseudo_typeS mach_o_pseudo_table[] =
{
  /* Section directives.  */
  { "comm", obj_mach_o_comm, 0 },
  { "lcomm", obj_mach_o_comm, 1 },

  { "text", obj_mach_o_base_section, 1},
  { "data", obj_mach_o_base_section, 2},
  { "bss", obj_mach_o_base_section, 3},   /* extension */

  { "const", obj_mach_o_known_section, 1},
  { "static_const", obj_mach_o_known_section, 2},
  { "cstring", obj_mach_o_known_section, 3},
  { "literal4", obj_mach_o_known_section, 4},
  { "literal8", obj_mach_o_known_section, 5},
  { "literal16", obj_mach_o_known_section, 6},
  { "constructor", obj_mach_o_known_section, 7},
  { "destructor", obj_mach_o_known_section, 8},
  { "eh_frame", obj_mach_o_known_section, 9},

  { "const_data", obj_mach_o_known_section, 10},
  { "static_data", obj_mach_o_known_section, 11},
  { "mod_init_func", obj_mach_o_known_section, 12},
  { "mod_term_func", obj_mach_o_known_section, 13},
  { "dyld", obj_mach_o_known_section, 14},
  { "cfstring", obj_mach_o_known_section, 15},

  { "objc_class", obj_mach_o_objc_section, 1},
  { "objc_meta_class", obj_mach_o_objc_section, 2},
  { "objc_cat_cls_meth", obj_mach_o_objc_section, 3},
  { "objc_cat_inst_meth", obj_mach_o_objc_section, 4},
  { "objc_protocol", obj_mach_o_objc_section, 5},
  { "objc_string_object", obj_mach_o_objc_section, 6},
  { "objc_cls_meth", obj_mach_o_objc_section, 7},
  { "objc_inst_meth", obj_mach_o_objc_section, 8},
  { "objc_cls_refs", obj_mach_o_objc_section, 9},
  { "objc_message_refs", obj_mach_o_objc_section, 10},
  { "objc_symbols", obj_mach_o_objc_section, 11},
  { "objc_category", obj_mach_o_objc_section, 12},
  { "objc_class_vars", obj_mach_o_objc_section, 13},
  { "objc_instance_vars", obj_mach_o_objc_section, 14},
  { "objc_module_info", obj_mach_o_objc_section, 15},
  { "objc_class_names", obj_mach_o_objc_section, 16}, /* Alias for .cstring */
  { "objc_meth_var_types", obj_mach_o_objc_section, 17}, /* Alias for .cstring */
  { "objc_meth_var_names", obj_mach_o_objc_section, 18}, /* Alias for .cstring */
  { "objc_selector_strs", obj_mach_o_objc_section, 19},
  { "objc_image_info", obj_mach_o_objc_section, 20}, /* extension.  */
  { "objc_selector_fixup", obj_mach_o_objc_section, 21}, /* extension.  */
  { "objc1_class_ext", obj_mach_o_objc_section, 22}, /* ObjC-1 extension.  */
  { "objc1_property_list", obj_mach_o_objc_section, 23}, /* ObjC-1 extension.  */
  { "objc1_protocol_ext", obj_mach_o_objc_section, 24}, /* ObjC-1 extension.  */

  { "debug_frame", obj_mach_o_debug_section, 1}, /* extension.  */
  { "debug_info", obj_mach_o_debug_section, 2}, /* extension.  */
  { "debug_abbrev", obj_mach_o_debug_section, 3}, /* extension.  */
  { "debug_aranges", obj_mach_o_debug_section, 4}, /* extension.  */
  { "debug_macinfo", obj_mach_o_debug_section, 5}, /* extension.  */
  { "debug_line", obj_mach_o_debug_section, 6}, /* extension.  */
  { "debug_loc", obj_mach_o_debug_section, 7}, /* extension.  */
  { "debug_pubnames", obj_mach_o_debug_section, 8}, /* extension.  */
  { "debug_pubtypes", obj_mach_o_debug_section, 9}, /* extension.  */
  { "debug_str", obj_mach_o_debug_section, 10}, /* extension.  */
  { "debug_ranges", obj_mach_o_debug_section, 11}, /* extension.  */
  { "debug_macro", obj_mach_o_debug_section, 12}, /* extension.  */

  { "lazy_symbol_pointer", obj_mach_o_opt_tgt_section, 1},
  { "lazy_symbol_pointer2", obj_mach_o_opt_tgt_section, 2}, /* extension.  */
  { "lazy_symbol_pointer3", obj_mach_o_opt_tgt_section, 3}, /* extension.  */
  { "non_lazy_symbol_pointer", obj_mach_o_opt_tgt_section, 4},
  { "non_lazy_symbol_pointer_x86", obj_mach_o_opt_tgt_section, 5}, /* extension.  */
  { "symbol_stub", obj_mach_o_opt_tgt_section, 6},
  { "symbol_stub1", obj_mach_o_opt_tgt_section, 7}, /* extension.  */
  { "picsymbol_stub", obj_mach_o_opt_tgt_section, 8}, /* extension.  */
  { "picsymbol_stub1", obj_mach_o_opt_tgt_section, 9}, /* extension.  */
  { "picsymbol_stub2", obj_mach_o_opt_tgt_section, 4}, /* extension.  */
  { "picsymbol_stub3", obj_mach_o_opt_tgt_section, 4}, /* extension.  */

  { "section", obj_mach_o_section, 0},
  { "zerofill", obj_mach_o_zerofill, 0},

  /* Symbol qualifiers.  */
  {"local",		obj_mach_o_sym_qual, OBJ_MACH_O_SYM_LOCAL},
  {"globl",		obj_mach_o_sym_qual, OBJ_MACH_O_SYM_GLOBL},
  {"reference",		obj_mach_o_sym_qual, OBJ_MACH_O_SYM_REFERENCE},
  {"weak_reference",	obj_mach_o_sym_qual, OBJ_MACH_O_SYM_WEAK_REF},
  {"lazy_reference",	obj_mach_o_sym_qual, OBJ_MACH_O_SYM_LAZY_REF},
  {"weak_definition",	obj_mach_o_sym_qual, OBJ_MACH_O_SYM_WEAK_DEF},
  {"private_extern",	obj_mach_o_sym_qual, OBJ_MACH_O_SYM_PRIV_EXT},
  {"no_dead_strip",	obj_mach_o_sym_qual, OBJ_MACH_O_SYM_NO_DEAD_STRIP},
  {"weak",		obj_mach_o_sym_qual, OBJ_MACH_O_SYM_WEAK}, /* ext */

  { "indirect_symbol",	obj_mach_o_indirect_symbol, 0},

  /* File flags.  */
  { "subsections_via_symbols", obj_mach_o_fileprop,
			       OBJ_MACH_O_FILE_PROP_SUBSECTS_VIA_SYMS},

  {NULL, NULL, 0}
};

/* Determine the default n_type value for a symbol from its section.  */

static unsigned
obj_mach_o_type_for_symbol (bfd_mach_o_asymbol *s)
{
  if (s->symbol.section == bfd_abs_section_ptr)
    return BFD_MACH_O_N_ABS;
  else if (s->symbol.section == bfd_com_section_ptr
	   || s->symbol.section == bfd_und_section_ptr)
    return BFD_MACH_O_N_UNDF;
  else
    return BFD_MACH_O_N_SECT;
}

void
obj_mach_o_frob_colon (const char *name)
{
  if (!bfd_is_local_label_name (stdoutput, name))
    {
      /* A non-local label will create a new subsection, so start a new
         frag.  */
      frag_wane (frag_now);
      frag_new (0);
    }
}

/* We need to check the correspondence between some kinds of symbols and their
   sections.  Common and BSS vars will seen via the obj_macho_comm() function.

   The earlier we can pick up a problem, the better the diagnostics will be.

   However, when symbol type information is attached, the symbol section will
   quite possibly be unknown.  So we are stuck with checking (most of the)
   validity at the time the file is written (unfortunately, then one doesn't
   get line number information in the diagnostic).  */

/* Here we pick up the case where symbol qualifiers have been applied that
   are possibly incompatible with the section etc. that the symbol is defined
   in.  */

void obj_mach_o_frob_label (struct symbol *sp)
{
  bfd_mach_o_asymbol *s;
  unsigned base_type;
  bfd_mach_o_section *sec;
  int sectype = -1;

  if (!bfd_is_local_label_name (stdoutput, S_GET_NAME (sp)))
    {
      /* If this is a non-local label, it should have started a new sub-
	 section.  */
      gas_assert (frag_now->obj_frag_data.subsection == NULL);
      frag_now->obj_frag_data.subsection = sp;
    }

  /* Leave local symbols alone.  */

  if (S_IS_LOCAL (sp))
    return;

  s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (sp);
  /* Leave debug symbols alone.  */
  if ((s->n_type & BFD_MACH_O_N_STAB) != 0)
    return;

  /* This is the base symbol type, that we mask in.  */
  base_type = obj_mach_o_type_for_symbol (s);

  sec = bfd_mach_o_get_mach_o_section (s->symbol.section);
  if (sec != NULL)
    sectype = sec->flags & BFD_MACH_O_SECTION_TYPE_MASK;

  /* If there is a pre-existing qualifier, we can make some checks about
     validity now.  */

  if(s->symbol.udata.i == SYM_MACHO_FIELDS_NOT_VALIDATED)
    {
      if ((s->n_desc & BFD_MACH_O_N_WEAK_DEF)
	  && sectype != BFD_MACH_O_S_COALESCED)
	{
	  as_bad (_("'%s' can't be a weak_definition (currently only supported"
		    " in sections of type coalesced)"), s->symbol.name);
	  /* Don't cascade errors.  */
	  s->symbol.udata.i = SYM_MACHO_FIELDS_UNSET;
	}

      /* Have we changed from an undefined to defined ref? */
      s->n_desc &= ~(REFE | LAZY);
    }

  s->n_type &= ~BFD_MACH_O_N_TYPE;
  s->n_type |= base_type;
}

/* This is the fall-back, we come here when we get to the end of the file and
   the symbol is not defined - or there are combinations of qualifiers required
   (e.g. global + weak_def).  */

int
obj_mach_o_frob_symbol (struct symbol *sp)
{
  bfd_mach_o_asymbol *s;
  unsigned base_type;
  bfd_mach_o_section *sec;
  int sectype = -1;

  /* Leave local symbols alone.  */
  if (S_IS_LOCAL (sp))
    return 0;

  s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (sp);
  /* Leave debug symbols alone.  */
  if ((s->n_type & BFD_MACH_O_N_STAB) != 0)
    return 0;

  base_type = obj_mach_o_type_for_symbol (s);
  sec = bfd_mach_o_get_mach_o_section (s->symbol.section);
  if (sec != NULL)
    sectype = sec->flags & BFD_MACH_O_SECTION_TYPE_MASK;

  if (s->symbol.section == bfd_und_section_ptr)
    {
      /* ??? Do we really gain much from implementing this as well as the
	 mach-o specific ones?  */
      if (s->symbol.flags & BSF_WEAK)
	s->n_desc |= BFD_MACH_O_N_WEAK_REF;

      /* Undefined syms, become extern.  */
      s->n_type |= BFD_MACH_O_N_EXT;
      S_SET_EXTERNAL (sp);
    }
  else if (s->symbol.section == bfd_com_section_ptr)
    {
      /* ... so do comm.  */
      s->n_type |= BFD_MACH_O_N_EXT;
      S_SET_EXTERNAL (sp);
    }
  else
    {
      if ((s->symbol.flags & BSF_WEAK)
	   && (sectype == BFD_MACH_O_S_COALESCED)
	   && (s->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT)))
	s->n_desc |= BFD_MACH_O_N_WEAK_DEF;
/* ??? we should do this - but then that reveals that the semantics of weak
       are different from what's supported in mach-o object files.
      else
	as_bad (_("'%s' can't be a weak_definition."),
		s->symbol.name); */
    }

  if (s->symbol.udata.i == SYM_MACHO_FIELDS_UNSET)
    {
      /* Anything here that should be added that is non-standard.  */
      s->n_desc &= ~BFD_MACH_O_REFERENCE_MASK;
    }
  else if (s->symbol.udata.i == SYM_MACHO_FIELDS_NOT_VALIDATED)
    {
      /* Try to validate any combinations.  */
      if (s->n_desc & BFD_MACH_O_N_WEAK_DEF)
	{
	  if (s->symbol.section == bfd_und_section_ptr)
	    as_bad (_("'%s' can't be a weak_definition (since it is"
		      " undefined)"), s->symbol.name);
	  else if (sectype != BFD_MACH_O_S_COALESCED)
	    as_bad (_("'%s' can't be a weak_definition (currently only supported"
		      " in sections of type coalesced)"), s->symbol.name);
	  else if (! (s->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT)))
	    as_bad (_("Non-global symbol: '%s' can't be a weak_definition."),
		    s->symbol.name);
	}

    }
  else
    as_bad (_("internal error: [%s] unexpected code [%lx] in frob symbol"),
	    s->symbol.name, (unsigned long)s->symbol.udata.i);

  s->n_type &= ~BFD_MACH_O_N_TYPE;
  s->n_type |= base_type;

  if (s->symbol.flags & BSF_GLOBAL)
    s->n_type |= BFD_MACH_O_N_EXT;

  /* This cuts both ways - we promote some things to external above.  */
  if (s->n_type & (BFD_MACH_O_N_PEXT | BFD_MACH_O_N_EXT))
    S_SET_EXTERNAL (sp);

  return 0;
}

/* Support stabs for mach-o.  */

void
obj_mach_o_process_stab (int what, const char *string,
			 int type, int other, int desc)
{
  symbolS *symbolP;
  bfd_mach_o_asymbol *s;

  switch (what)
    {
      case 'd':
	symbolP = symbol_new ("", now_seg, frag_now, frag_now_fix ());
	/* Special stabd NULL name indicator.  */
	S_SET_NAME (symbolP, NULL);
	break;

      case 'n':
      case 's':
	symbolP = symbol_new (string, undefined_section,
			      &zero_address_frag, 0);
	pseudo_set (symbolP);
	break;

      default:
	as_bad(_("unrecognized stab type '%c'"), (char)what);
	abort ();
	break;
    }

  s = (bfd_mach_o_asymbol *) symbol_get_bfdsym (symbolP);
  s->n_type = type;
  s->n_desc = desc;
  /* For stabd, this will eventually get overwritten by the section number.  */
  s->n_sect = other;

  /* It's a debug symbol.  */
  s->symbol.flags |= BSF_DEBUGGING;

  /* We've set it - so check it, if you can, but don't try to create the
     flags.  */
  s->symbol.udata.i = SYM_MACHO_FIELDS_NOT_VALIDATED;
}

/* This is a place to check for any errors that we can't detect until we know
   what remains undefined at the end of assembly.  */

static void
obj_mach_o_check_before_writing (bfd *abfd ATTRIBUTE_UNUSED,
				 asection *sec,
				 void *unused ATTRIBUTE_UNUSED)
{
  fixS *fixP;
  struct frchain *frchp;
  segment_info_type *seginfo = seg_info (sec);

  if (seginfo == NULL)
    return;

  /* We are not allowed subtractions where either of the operands is
     undefined.  So look through the frags for any fixes to check.  */
  for (frchp = seginfo->frchainP; frchp != NULL; frchp = frchp->frch_next)
   for (fixP = frchp->fix_root; fixP != NULL; fixP = fixP->fx_next)
    {
      if (fixP->fx_addsy != NULL
	  && fixP->fx_subsy != NULL
	  && (! S_IS_DEFINED (fixP->fx_addsy)
	      || ! S_IS_DEFINED (fixP->fx_subsy)))
	{
	  segT add_symbol_segment = S_GET_SEGMENT (fixP->fx_addsy);
	  segT sub_symbol_segment = S_GET_SEGMENT (fixP->fx_subsy);

	  if (! S_IS_DEFINED (fixP->fx_addsy)
	      && S_IS_DEFINED (fixP->fx_subsy))
	    {
	      as_bad_where (fixP->fx_file, fixP->fx_line,
		_("`%s' can't be undefined in `%s' - `%s' {%s section}"),
		S_GET_NAME (fixP->fx_addsy), S_GET_NAME (fixP->fx_addsy),
		S_GET_NAME (fixP->fx_subsy), segment_name (sub_symbol_segment));
	    }
	  else if (! S_IS_DEFINED (fixP->fx_subsy)
		   && S_IS_DEFINED (fixP->fx_addsy))
	    {
	      as_bad_where (fixP->fx_file, fixP->fx_line,
		_("`%s' can't be undefined in `%s' {%s section} - `%s'"),
		S_GET_NAME (fixP->fx_subsy), S_GET_NAME (fixP->fx_addsy),
		segment_name (add_symbol_segment), S_GET_NAME (fixP->fx_subsy));
	    }
	  else
	    {
	      as_bad_where (fixP->fx_file, fixP->fx_line,
		_("`%s' and `%s' can't be undefined in `%s' - `%s'"),
		S_GET_NAME (fixP->fx_addsy), S_GET_NAME (fixP->fx_subsy),
		S_GET_NAME (fixP->fx_addsy), S_GET_NAME (fixP->fx_subsy));
	    }
	}
    }
}

/* Do any checks that we can't complete without knowing what's undefined.  */
void
obj_mach_o_pre_output_hook (void)
{
  bfd_map_over_sections (stdoutput, obj_mach_o_check_before_writing, (char *) 0);
}

/* Here we count up frags in each subsection (where a sub-section is defined
   as starting with a non-local symbol).
   Note that, if there are no non-local symbols in a section, all the frags will
   be attached as one anonymous subsection.  */

static void
obj_mach_o_set_subsections (bfd *abfd ATTRIBUTE_UNUSED,
                            asection *sec,
                            void *unused ATTRIBUTE_UNUSED)
{
  segment_info_type *seginfo = seg_info (sec);
  symbolS *cur_subsection = NULL;
  struct obj_mach_o_symbol_data *cur_subsection_data = NULL;
  fragS *frag;
  frchainS *chain;

  /* Protect against sections not created by gas.  */
  if (seginfo == NULL)
    return;

  /* Attach every frag to a subsection.  */
  for (chain = seginfo->frchainP; chain != NULL; chain = chain->frch_next)
    for (frag = chain->frch_root; frag != NULL; frag = frag->fr_next)
      {
        if (frag->obj_frag_data.subsection == NULL)
          frag->obj_frag_data.subsection = cur_subsection;
        else
          {
            cur_subsection = frag->obj_frag_data.subsection;
            cur_subsection_data = symbol_get_obj (cur_subsection);
            cur_subsection_data->subsection_size = 0;
          }
        if (cur_subsection_data != NULL)
          {
            /* Update subsection size.  */
            cur_subsection_data->subsection_size += frag->fr_fix;
          }
      }
}

/* Handle mach-o subsections-via-symbols counting up frags belonging to each
   sub-section.  */

void
obj_mach_o_pre_relax_hook (void)
{
  bfd_map_over_sections (stdoutput, obj_mach_o_set_subsections, (char *) 0);
}

/* Zerofill and GB Zerofill sections must be sorted to follow all other
   sections in their segments.

   The native 'as' leaves the sections physically in the order they appear in
   the source, and adjusts the section VMAs to meet the constraint.

   We follow this for now - if nothing else, it makes comparison easier.

   An alternative implementation would be to sort the sections as ld requires.
   It might be advantageous to implement such a scheme in the future (or even
   to make the style of section ordering user-selectable).  */

typedef struct obj_mach_o_set_vma_data
{
  bfd_vma vma;
  unsigned vma_pass;
  unsigned zerofill_seen;
  unsigned gb_zerofill_seen;
} obj_mach_o_set_vma_data;

/* We do (possibly) three passes through to set the vma, so that:

   zerofill sections get VMAs after all others in their segment
   GB zerofill get VMAs last.

   As we go, we notice if we see any Zerofill or GB Zerofill sections, so that
   we can skip the additional passes if there's nothing to do.  */

static void
obj_mach_o_set_section_vma (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *v_p)
{
  bfd_mach_o_section *ms = bfd_mach_o_get_mach_o_section (sec);
  unsigned bfd_align = bfd_section_alignment (sec);
  obj_mach_o_set_vma_data *p = (struct obj_mach_o_set_vma_data *)v_p;
  unsigned sectype = (ms->flags & BFD_MACH_O_SECTION_TYPE_MASK);
  unsigned zf;

  zf = 0;
  if (sectype == BFD_MACH_O_S_ZEROFILL)
    {
      zf = 1;
      p->zerofill_seen = zf;
    }
  else if (sectype == BFD_MACH_O_S_GB_ZEROFILL)
    {
      zf = 2;
      p->gb_zerofill_seen = zf;
    }

  if (p->vma_pass != zf)
    return;

  /* We know the section size now - so make a vma for the section just
     based on order.  */
  ms->size = bfd_section_size (sec);

  /* Make sure that the align agrees, and set to the largest value chosen.  */
  ms->align = ms->align > bfd_align ? ms->align : bfd_align;
  bfd_set_section_alignment (sec, ms->align);

  p->vma += (1 << ms->align) - 1;
  p->vma &= ~((1 << ms->align) - 1);
  ms->addr = p->vma;
  bfd_set_section_vma (sec, p->vma);
  p->vma += ms->size;
}

/* (potentially) three passes over the sections, setting VMA.  We skip the
  {gb}zerofill passes if we didn't see any of the relevant sections.  */

void obj_mach_o_post_relax_hook (void)
{
  obj_mach_o_set_vma_data d;

  memset (&d, 0, sizeof (d));

  bfd_map_over_sections (stdoutput, obj_mach_o_set_section_vma, (char *) &d);
  if ((d.vma_pass = d.zerofill_seen) != 0)
    bfd_map_over_sections (stdoutput, obj_mach_o_set_section_vma, (char *) &d);
  if ((d.vma_pass = d.gb_zerofill_seen) != 0)
    bfd_map_over_sections (stdoutput, obj_mach_o_set_section_vma, (char *) &d);
}

static void
obj_mach_o_set_indirect_symbols (bfd *abfd, asection *sec,
				 void *xxx ATTRIBUTE_UNUSED)
{
  bfd_vma sect_size = bfd_section_size (sec);
  bfd_mach_o_section *ms = bfd_mach_o_get_mach_o_section (sec);
  unsigned lazy = 0;

  /* See if we have any indirect syms to consider.  */
  if (indirect_syms == NULL)
    return;

  /* Process indirect symbols.
     Check for errors, if OK attach them as a flat array to the section
     for which they are defined.  */

  switch (ms->flags & BFD_MACH_O_SECTION_TYPE_MASK)
    {
      case BFD_MACH_O_S_SYMBOL_STUBS:
      case BFD_MACH_O_S_LAZY_SYMBOL_POINTERS:
	lazy = LAZY;
	/* Fall through.  */
      case BFD_MACH_O_S_NON_LAZY_SYMBOL_POINTERS:
	{
	  unsigned int nactual = 0;
	  unsigned int ncalc;
	  obj_mach_o_indirect_sym *isym;
	  obj_mach_o_indirect_sym *list = NULL;
	  obj_mach_o_indirect_sym *list_tail = NULL;
	  unsigned long eltsiz =
			bfd_mach_o_section_get_entry_size (abfd, ms);

	  for (isym = indirect_syms; isym != NULL; isym = isym->next)
	    {
	      if (isym->sect == sec)
		{
		  nactual++;
		  if (list == NULL)
		    list = isym;
		  else
		    list_tail->next = isym;
		  list_tail = isym;
		}
	    }

	  /* If none are in this section, stop here.  */
	  if (nactual == 0)
	    break;

	  /* If we somehow added indirect symbols to a section with a zero
	     entry size, we're dead ... */
	  gas_assert (eltsiz != 0);

	  ncalc = (unsigned int) (sect_size / eltsiz);
	  if (nactual != ncalc)
	    as_bad (_("the number of .indirect_symbols defined in section %s"
		      " does not match the number expected (%d defined, %d"
		      " expected)"), sec->name, nactual, ncalc);
	  else
	    {
	      unsigned n;
	      bfd_mach_o_asymbol *sym;

	      /* FIXME: It seems that there can be more indirect symbols
		 than is computed by the loop above.  So be paranoid and
		 allocate enough space for every symbol to be indirect.
		 See PR 21939 for an example of where this is needed.  */
	      if (nactual < bfd_get_symcount (abfd))
		nactual = bfd_get_symcount (abfd);

	      ms->indirect_syms =
			bfd_zalloc (abfd,
				    nactual * sizeof (bfd_mach_o_asymbol *));

	      if (ms->indirect_syms == NULL)
		as_fatal (_("internal error: failed to allocate %d indirect"
			    "symbol pointers"), nactual);

	      for (isym = list, n = 0; isym != NULL; isym = isym->next, n++)
		{
		  sym = (bfd_mach_o_asymbol *)symbol_get_bfdsym (isym->sym);
		  /* Array is init to NULL & NULL signals a local symbol
		     If the section is lazy-bound, we need to keep the
		     reference to the symbol, since dyld can override.

		     Absolute symbols are handled specially.  */
		  if (sym->symbol.section == bfd_abs_section_ptr)
		    {
		      if (n >= nactual)
			as_fatal (_("internal error: more indirect mach-o symbols than expected"));
		      ms->indirect_syms[n] = sym;
		    }
		  else if (S_IS_LOCAL (isym->sym) && ! lazy)
		    ;
		  else
		    {
		      if (sym == NULL)
		        ;
		      /* If the symbols is external ...  */
		      else if (S_IS_EXTERNAL (isym->sym)
			       || (sym->n_type & BFD_MACH_O_N_EXT)
			       || ! S_IS_DEFINED (isym->sym)
			       || lazy)
			{
			  sym->n_desc &= ~LAZY;
			  /* ... it can be lazy, if not defined or hidden.  */
			  if ((sym->n_type & BFD_MACH_O_N_TYPE)
			       == BFD_MACH_O_N_UNDF
			      && ! (sym->n_type & BFD_MACH_O_N_PEXT)
			      && (sym->n_type & BFD_MACH_O_N_EXT))
			    sym->n_desc |= lazy;
			  if (n >= nactual)
			    as_fatal (_("internal error: more indirect mach-o symbols than expected"));
			  ms->indirect_syms[n] = sym;
		        }
		    }
		}
	    }
	}
	break;

      default:
	break;
    }
}

/* The process of relocation could alter what's externally visible, thus we
   leave setting the indirect symbols until last.  */

void
obj_mach_o_frob_file_after_relocs (void)
{
  bfd_map_over_sections (stdoutput, obj_mach_o_set_indirect_symbols, (char *) 0);
}

/* Reverse relocations order to make ld happy.  */

void
obj_mach_o_reorder_section_relocs (asection *sec, arelent **rels, unsigned int n)
{
  unsigned int i;
  unsigned int max = n / 2;

  for (i = 0; i < max; i++)
    {
      arelent *r = rels[i];
      rels[i] = rels[n - i - 1];
      rels[n - i - 1] = r;
    }
  bfd_set_reloc (stdoutput, sec, rels, n);
}

/* Relocation rules are different in frame sections.  */

static int
obj_mach_o_is_frame_section (segT sec)
{
  int l;
  l = strlen (segment_name (sec));
  if ((l == 9 && startswith (segment_name (sec), ".eh_frame"))
       || (l == 12 && startswith (segment_name (sec), ".debug_frame")))
    return 1;
  return 0;
}

/* Unless we're in a frame section, we need to force relocs to be generated for
   local subtractions.  We might eliminate them later (if they are within the
   same sub-section) but we don't know that at the point that this decision is
   being made.  */

int
obj_mach_o_allow_local_subtract (expressionS * left ATTRIBUTE_UNUSED,
				 expressionS * right ATTRIBUTE_UNUSED,
				 segT seg)
{
  /* Don't interfere if it's one of the GAS internal sections.  */
  if (! SEG_NORMAL (seg))
    return 1;

  /* Allow in frame sections, otherwise emit a reloc.  */
  return obj_mach_o_is_frame_section (seg);
}

int
obj_mach_o_in_different_subsection (symbolS *a, symbolS *b)
{
  fragS *fa;
  fragS *fb;

  if (S_GET_SEGMENT (a) != S_GET_SEGMENT (b)
      || !S_IS_DEFINED (a)
      || !S_IS_DEFINED (b))
    {
      /* Not in the same segment, or undefined symbol.  */
      return 1;
    }

  fa = symbol_get_frag (a);
  fb = symbol_get_frag (b);
  if (fa == NULL || fb == NULL)
    {
      /* One of the symbols is not in a subsection.  */
      return 1;
    }

  return fa->obj_frag_data.subsection != fb->obj_frag_data.subsection;
}

int
obj_mach_o_force_reloc_sub_same (fixS *fix, segT seg)
{
  if (! SEG_NORMAL (seg))
    return 1;
  return obj_mach_o_in_different_subsection (fix->fx_addsy, fix->fx_subsy);
}

int
obj_mach_o_force_reloc_sub_local (fixS *fix, segT seg ATTRIBUTE_UNUSED)
{
  return obj_mach_o_in_different_subsection (fix->fx_addsy, fix->fx_subsy);
}

int
obj_mach_o_force_reloc (fixS *fix)
{
  if (generic_force_reloc (fix))
    return 1;

  /* Force a reloc if the target is not in the same subsection.
     FIXME: handle (a - b) where a and b belongs to the same subsection ?  */
  if (fix->fx_addsy != NULL)
    {
      symbolS *subsec = fix->fx_frag->obj_frag_data.subsection;
      symbolS *targ = fix->fx_addsy;

      /* There might be no subsections at all.  */
      if (subsec == NULL)
        return 0;

      if (S_GET_SEGMENT (targ) == absolute_section)
        return 0;

      return obj_mach_o_in_different_subsection (targ, subsec);
    }
  return 0;
}