summaryrefslogtreecommitdiff
path: root/gcc/ada/init.c
blob: c4e260104adea710788017715882682033e00bad (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
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
/****************************************************************************
 *                                                                          *
 *                         GNAT COMPILER COMPONENTS                         *
 *                                                                          *
 *                                 I N I T                                  *
 *                                                                          *
 *                          C Implementation File                           *
 *                                                                          *
 *          Copyright (C) 1992-2008, Free Software Foundation, Inc.         *
 *                                                                          *
 * GNAT is free software;  you can  redistribute it  and/or modify it under *
 * terms of the  GNU General Public License as published  by the Free Soft- *
 * ware  Foundation;  either version 2,  or (at your option) any later ver- *
 * sion.  GNAT is distributed in the hope that it will be useful, but WITH- *
 * OUT 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  distributed with GNAT;  see file COPYING.  If not, write *
 * to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, *
 * Boston, MA 02110-1301, USA.                                              *
 *                                                                          *
 * As a  special  exception,  if you  link  this file  with other  files to *
 * produce an executable,  this file does not by itself cause the resulting *
 * executable to be covered by the GNU General Public License. This except- *
 * ion does not  however invalidate  any other reasons  why the  executable *
 * file might be covered by the  GNU Public License.                        *
 *                                                                          *
 * GNAT was originally developed  by the GNAT team at  New York University. *
 * Extensive contributions were provided by Ada Core Technologies Inc.      *
 *                                                                          *
 ****************************************************************************/

/*  This unit contains initialization circuits that are system dependent.
    A major part of the functionality involves stack overflow checking.
    The GCC backend generates probe instructions to test for stack overflow.
    For details on the exact approach used to generate these probes, see the
    "Using and Porting GCC" manual, in particular the "Stack Checking" section
    and the subsection "Specifying How Stack Checking is Done".  The handlers
    installed by this file are used to catch the resulting signals that come
    from these probes failing (i.e. touching protected pages).  */

/* This file should be kept synchronized with 2sinit.ads, 2sinit.adb,
   s-init-ae653-cert.adb and s-init-xi-sparc.adb.  All these files implement
   the required functionality for different targets.  */

/* The following include is here to meet the published VxWorks requirement
   that the __vxworks header appear before any other include.  */
#ifdef __vxworks
#include "vxWorks.h"
#endif

#ifdef IN_RTS
#include "tconfig.h"
#include "tsystem.h"
#include <sys/stat.h>

/* We don't have libiberty, so us malloc.  */
#define xmalloc(S) malloc (S)
#else
#include "config.h"
#include "system.h"
#endif

#include "adaint.h"
#include "raise.h"

extern void __gnat_raise_program_error (const char *, int);

/* Addresses of exception data blocks for predefined exceptions.  Tasking_Error
   is not used in this unit, and the abort signal is only used on IRIX.  */
extern struct Exception_Data constraint_error;
extern struct Exception_Data numeric_error;
extern struct Exception_Data program_error;
extern struct Exception_Data storage_error;

/* For the Cert run time we use the regular raise exception routine because
   Raise_From_Signal_Handler is not available.  */
#ifdef CERT
#define Raise_From_Signal_Handler \
                      __gnat_raise_exception
extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *);
#else
#define Raise_From_Signal_Handler \
                      ada__exceptions__raise_from_signal_handler
extern void Raise_From_Signal_Handler (struct Exception_Data *, const char *);
#endif

/* Global values computed by the binder.  */
int   __gl_main_priority                 = -1;
int   __gl_time_slice_val                = -1;
char  __gl_wc_encoding                   = 'n';
char  __gl_locking_policy                = ' ';
char  __gl_queuing_policy                = ' ';
char  __gl_task_dispatching_policy       = ' ';
char *__gl_priority_specific_dispatching = 0;
int   __gl_num_specific_dispatching      = 0;
char *__gl_interrupt_states              = 0;
int   __gl_num_interrupt_states          = 0;
int   __gl_unreserve_all_interrupts      = 0;
int   __gl_exception_tracebacks          = 0;
int   __gl_zero_cost_exceptions          = 0;
int   __gl_detect_blocking               = 0;
int   __gl_default_stack_size            = -1;
int   __gl_leap_seconds_support          = 0;
int   __gl_canonical_streams             = 0;

/* Indication of whether synchronous signal handler has already been
   installed by a previous call to adainit.  */
int  __gnat_handler_installed      = 0;

#ifndef IN_RTS
int __gnat_inside_elab_final_code = 0;
/* ??? This variable is obsolete since 2001-08-29 but is kept to allow
   bootstrap from old GNAT versions (< 3.15).  */
#endif

/* HAVE_GNAT_INIT_FLOAT must be set on every targets where a __gnat_init_float
   is defined.  If this is not set then a void implementation will be defined
   at the end of this unit.  */
#undef HAVE_GNAT_INIT_FLOAT

/******************************/
/* __gnat_get_interrupt_state */
/******************************/

char __gnat_get_interrupt_state (int);

/* This routine is called from the runtime as needed to determine the state
   of an interrupt, as set by an Interrupt_State pragma appearing anywhere
   in the current partition.  The input argument is the interrupt number,
   and the result is one of the following:

       'n'   this interrupt not set by any Interrupt_State pragma
       'u'   Interrupt_State pragma set state to User
       'r'   Interrupt_State pragma set state to Runtime
       's'   Interrupt_State pragma set state to System  */

char
__gnat_get_interrupt_state (int intrup)
{
  if (intrup >= __gl_num_interrupt_states)
    return 'n';
  else
    return __gl_interrupt_states [intrup];
}

/***********************************/
/* __gnat_get_specific_dispatching */
/***********************************/

char __gnat_get_specific_dispatching (int);

/* This routine is called from the runtime as needed to determine the
   priority specific dispatching policy, as set by a
   Priority_Specific_Dispatching pragma appearing anywhere in the current
   partition.  The input argument is the priority number, and the result
   is the upper case first character of the policy name, e.g. 'F' for
   FIFO_Within_Priorities. A space ' ' is returned if no
   Priority_Specific_Dispatching pragma is used in the partition.  */

char
__gnat_get_specific_dispatching (int priority)
{
  if (__gl_num_specific_dispatching == 0)
    return ' ';
  else if (priority >= __gl_num_specific_dispatching)
    return 'F';
  else
    return __gl_priority_specific_dispatching [priority];
}

#ifndef IN_RTS

/**********************/
/* __gnat_set_globals */
/**********************/

/* This routine is kept for bootstrapping purposes, since the binder generated
   file now sets the __gl_* variables directly.  */

void
__gnat_set_globals ()
{
}

#endif

/***************/
/* AIX Section */
/***************/

#if defined (_AIX)

#include <signal.h>
#include <sys/time.h>

/* Some versions of AIX don't define SA_NODEFER.  */

#ifndef SA_NODEFER
#define SA_NODEFER 0
#endif /* SA_NODEFER */

/* Versions of AIX before 4.3 don't have nanosleep but provide
   nsleep instead.  */

#ifndef _AIXVERSION_430

extern int nanosleep (struct timestruc_t *, struct timestruc_t *);

int
nanosleep (struct timestruc_t *Rqtp, struct timestruc_t *Rmtp)
{
  return nsleep (Rqtp, Rmtp);
}

#endif /* _AIXVERSION_430 */

static void __gnat_error_handler (int sig, siginfo_t * si, void * uc);

static void
__gnat_error_handler (int sig, siginfo_t * si, void * uc)
{
  struct Exception_Data *exception;
  const char *msg;

  switch (sig)
    {
    case SIGSEGV:
      /* FIXME: we need to detect the case of a *real* SIGSEGV.  */
      exception = &storage_error;
      msg = "stack overflow or erroneous memory access";
      break;

    case SIGBUS:
      exception = &constraint_error;
      msg = "SIGBUS";
      break;

    case SIGFPE:
      exception = &constraint_error;
      msg = "SIGFPE";
      break;

    default:
      exception = &program_error;
      msg = "unhandled signal";
    }

  Raise_From_Signal_Handler (exception, msg);
}

void
__gnat_install_handler (void)
{
  struct sigaction act;

  /* Set up signal handler to map synchronous signals to appropriate
     exceptions.  Make sure that the handler isn't interrupted by another
     signal that might cause a scheduling event!  */

  act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
  act.sa_sigaction = __gnat_error_handler;
  sigemptyset (&act.sa_mask);

  /* Do not install handlers if interrupt state is "System".  */
  if (__gnat_get_interrupt_state (SIGABRT) != 's')
    sigaction (SIGABRT, &act, NULL);
  if (__gnat_get_interrupt_state (SIGFPE) != 's')
    sigaction (SIGFPE,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGILL) != 's')
    sigaction (SIGILL,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGSEGV) != 's')
    sigaction (SIGSEGV, &act, NULL);
  if (__gnat_get_interrupt_state (SIGBUS) != 's')
    sigaction (SIGBUS,  &act, NULL);

  __gnat_handler_installed = 1;
}

/*****************/
/* Tru64 section */
/*****************/

#elif defined(__alpha__) && defined(__osf__)

#include <signal.h>
#include <sys/siginfo.h>

static void __gnat_error_handler (int, siginfo_t *, struct sigcontext *);
extern char *__gnat_get_code_loc (struct sigcontext *);
extern void __gnat_set_code_loc (struct sigcontext *, char *);
extern size_t __gnat_machine_state_length (void);

/* __gnat_adjust_context_for_raise - see comments along with the default
   version later in this file.  */

#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE

void
__gnat_adjust_context_for_raise (int signo, void *context)
{
  struct sigcontext * sigcontext = (struct sigcontext *) context;

  /* The fallback code fetches the faulting insn address from sc_pc, so
     adjust that when need be.  For SIGFPE, the required adjustment depends
     on the trap shadow situation (see man ieee).  */
  if (signo == SIGFPE)
    {
      /* ??? We never adjust here, considering that sc_pc always
	 designates the instruction following the one which trapped.
	 This is not necessarily true but corresponds to what we have
	 always observed.  */
    }
  else
    sigcontext->sc_pc ++;
}

static void
__gnat_error_handler
  (int sig, siginfo_t *sip, struct sigcontext *context)
{
  struct Exception_Data *exception;
  static int recurse = 0;
  const char *msg;

  /* Adjusting is required for every fault context, so adjust for this one
     now, before we possibly trigger a recursive fault below.  */
  __gnat_adjust_context_for_raise (sig, context);

  /* If this was an explicit signal from a "kill", just resignal it.  */
  if (SI_FROMUSER (sip))
    {
      signal (sig, SIG_DFL);
      kill (getpid(), sig);
    }

  /* Otherwise, treat it as something we handle.  */
  switch (sig)
    {
    case SIGSEGV:
      /* If the problem was permissions, this is a constraint error.
	 Likewise if the failing address isn't maximally aligned or if
	 we've recursed.

	 ??? Using a static variable here isn't task-safe, but it's
	 much too hard to do anything else and we're just determining
	 which exception to raise.  */
      if (sip->si_code == SEGV_ACCERR
	  || (((long) sip->si_addr) & 3) != 0
	  || recurse)
	{
	  exception = &constraint_error;
	  msg = "SIGSEGV";
	}
      else
	{
	  /* See if the page before the faulting page is accessible.  Do that
	     by trying to access it.  We'd like to simply try to access
	     4096 + the faulting address, but it's not guaranteed to be
	     the actual address, just to be on the same page.  */
	  recurse++;
	  ((volatile char *)
	   ((long) sip->si_addr & - getpagesize ()))[getpagesize ()];
	  msg = "stack overflow (or erroneous memory access)";
	  exception = &storage_error;
	}
      break;

    case SIGBUS:
      exception = &program_error;
      msg = "SIGBUS";
      break;

    case SIGFPE:
      exception = &constraint_error;
      msg = "SIGFPE";
      break;

    default:
      exception = &program_error;
      msg = "unhandled signal";
    }

  recurse = 0;
  Raise_From_Signal_Handler (exception, (char *) msg);
}

void
__gnat_install_handler (void)
{
  struct sigaction act;

  /* Setup signal handler to map synchronous signals to appropriate
     exceptions. Make sure that the handler isn't interrupted by another
     signal that might cause a scheduling event!  */

  act.sa_handler = (void (*) (int)) __gnat_error_handler;
  act.sa_flags = SA_RESTART | SA_NODEFER | SA_SIGINFO;
  sigemptyset (&act.sa_mask);

  /* Do not install handlers if interrupt state is "System".  */
  if (__gnat_get_interrupt_state (SIGABRT) != 's')
    sigaction (SIGABRT, &act, NULL);
  if (__gnat_get_interrupt_state (SIGFPE) != 's')
    sigaction (SIGFPE,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGILL) != 's')
    sigaction (SIGILL,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGSEGV) != 's')
    sigaction (SIGSEGV, &act, NULL);
  if (__gnat_get_interrupt_state (SIGBUS) != 's')
    sigaction (SIGBUS,  &act, NULL);

  __gnat_handler_installed = 1;
}

/* Routines called by s-mastop-tru64.adb.  */

#define SC_GP 29

char *
__gnat_get_code_loc (struct sigcontext *context)
{
  return (char *) context->sc_pc;
}

void
__gnat_set_code_loc (struct sigcontext *context, char *pc)
{
  context->sc_pc = (long) pc;
}

size_t
__gnat_machine_state_length (void)
{
  return sizeof (struct sigcontext);
}

/*****************/
/* HP-UX section */
/*****************/

#elif defined (__hpux__)

#include <signal.h>
#include <sys/ucontext.h>

static void
__gnat_error_handler (int sig, siginfo_t *siginfo, void *ucontext);

static void
__gnat_error_handler
  (int sig, siginfo_t *siginfo ATTRIBUTE_UNUSED, void *ucontext)
{
  struct Exception_Data *exception;
  const char *msg;

  switch (sig)
    {
    case SIGSEGV:
      /* FIXME: we need to detect the case of a *real* SIGSEGV.  */
      exception = &storage_error;
      msg = "stack overflow or erroneous memory access";
      break;

    case SIGBUS:
      exception = &constraint_error;
      msg = "SIGBUS";
      break;

    case SIGFPE:
      exception = &constraint_error;
      msg = "SIGFPE";
      break;

    default:
      exception = &program_error;
      msg = "unhandled signal";
    }

  Raise_From_Signal_Handler (exception, msg);
}

/* This must be in keeping with System.OS_Interface.Alternate_Stack_Size.  */
#if defined (__hppa__)
char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
#else
char __gnat_alternate_stack[128 * 1024]; /* MINSIGSTKSZ */
#endif

void
__gnat_install_handler (void)
{
  struct sigaction act;

  /* Set up signal handler to map synchronous signals to appropriate
     exceptions.  Make sure that the handler isn't interrupted by another
     signal that might cause a scheduling event!  Also setup an alternate
     stack region for the handler execution so that stack overflows can be
     handled properly, avoiding a SEGV generation from stack usage by the
     handler itself.  */

  stack_t stack;
  stack.ss_sp = __gnat_alternate_stack;
  stack.ss_size = sizeof (__gnat_alternate_stack);
  stack.ss_flags = 0;
  sigaltstack (&stack, NULL);

  act.sa_sigaction = __gnat_error_handler;
  act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
  sigemptyset (&act.sa_mask);

  /* Do not install handlers if interrupt state is "System".  */
  if (__gnat_get_interrupt_state (SIGABRT) != 's')
    sigaction (SIGABRT, &act, NULL);
  if (__gnat_get_interrupt_state (SIGFPE) != 's')
    sigaction (SIGFPE,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGILL) != 's')
    sigaction (SIGILL,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGBUS) != 's')
    sigaction (SIGBUS,  &act, NULL);
  act.sa_flags |= SA_ONSTACK;
  if (__gnat_get_interrupt_state (SIGSEGV) != 's')
    sigaction (SIGSEGV, &act, NULL);

  __gnat_handler_installed = 1;
}

/*********************/
/* GNU/Linux Section */
/*********************/

#elif defined (linux) && (defined (i386) || defined (__x86_64__) \
                          || defined (__ia64__) || defined (__powerpc__))

#include <signal.h>

#define __USE_GNU 1 /* required to get REG_EIP/RIP from glibc's ucontext.h */
#include <sys/ucontext.h>

/* GNU/Linux, which uses glibc, does not define NULL in included
   header files.  */

#if !defined (NULL)
#define NULL ((void *) 0)
#endif

#if defined (MaRTE)

/* MaRTE OS provides its own version of sigaction, sigfillset, and
   sigemptyset (overriding these symbol names).  We want to make sure that
   the versions provided by the underlying C library are used here (these
   versions are renamed by MaRTE to linux_sigaction, fake_linux_sigfillset,
   and fake_linux_sigemptyset, respectively).  The MaRTE library will not
   always be present (it will not be linked if no tasking constructs are
   used), so we use the weak symbol mechanism to point always to the symbols
   defined within the C library.  */

#pragma weak linux_sigaction
int linux_sigaction (int signum, const struct sigaction *act,
		     struct sigaction *oldact) {
  return sigaction (signum, act, oldact);
}
#define sigaction(signum, act, oldact) linux_sigaction (signum, act, oldact)

#pragma weak fake_linux_sigfillset
void fake_linux_sigfillset (sigset_t *set) {
  sigfillset (set);
}
#define sigfillset(set) fake_linux_sigfillset (set)

#pragma weak fake_linux_sigemptyset
void fake_linux_sigemptyset (sigset_t *set) {
  sigemptyset (set);
}
#define sigemptyset(set) fake_linux_sigemptyset (set)

#endif

static void __gnat_error_handler (int, siginfo_t *siginfo, void *ucontext);

#if defined (i386) || defined (__x86_64__) || defined (__ia64__)

#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE

void
__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
{
  mcontext_t *mcontext = &((ucontext_t *) ucontext)->uc_mcontext;

  /* On the i386 and x86-64 architectures, stack checking is performed by
     means of probes with moving stack pointer, that is to say the probed
     address is always the value of the stack pointer.  Upon hitting the
     guard page, the stack pointer therefore points to an inaccessible
     address and an alternate signal stack is needed to run the handler.
     But there is an additional twist: on these architectures, the EH
     return code writes the address of the handler at the target CFA's
     value on the stack before doing the jump.  As a consequence, if
     there is an active handler in the frame whose stack has overflowed,
     the stack pointer must nevertheless point to an accessible address
     by the time the EH return is executed.

     We therefore adjust the saved value of the stack pointer by the size
     of one page, in order to make sure that it points to an accessible
     address in case it's used as the target CFA.  The stack checking code
     guarantees that this page is unused by the time this happens.  */

#if defined (i386)
  unsigned long pattern = *(unsigned long *)mcontext->gregs[REG_EIP];
  /* The pattern is "orl $0x0,(%esp)" for a probe in 32-bit mode.  */
  if (signo == SIGSEGV && pattern == 0x00240c83)
    mcontext->gregs[REG_ESP] += 4096;
#elif defined (__x86_64__)
  unsigned long pattern = *(unsigned long *)mcontext->gregs[REG_RIP];
  /* The pattern is "orq $0x0,(%rsp)" for a probe in 64-bit mode.  */
  if (signo == SIGSEGV && (pattern & 0xffffffffff) == 0x00240c8348)
    mcontext->gregs[REG_RSP] += 4096;
#elif defined (__ia64__)
  /* ??? The IA-64 unwinder doesn't compensate for signals.  */
  mcontext->sc_ip++;
#endif
}

#endif

static void
__gnat_error_handler (int sig,
                      siginfo_t *siginfo ATTRIBUTE_UNUSED,
                      void *ucontext)
{
  struct Exception_Data *exception;
  const char *msg;
  static int recurse = 0;

  switch (sig)
    {
    case SIGSEGV:
      /* If the problem was permissions, this is a constraint error.
       Likewise if the failing address isn't maximally aligned or if
       we've recursed.

       ??? Using a static variable here isn't task-safe, but it's
       much too hard to do anything else and we're just determining
       which exception to raise.  */
      if (recurse)
      {
        exception = &constraint_error;
        msg = "SIGSEGV";
      }
      else
      {
        /* Here we would like a discrimination test to see whether the
           page before the faulting address is accessible. Unfortunately
           Linux seems to have no way of giving us the faulting address.

           In versions of a-init.c before 1.95, we had a test of the page
           before the stack pointer using:

            recurse++;
             ((volatile char *)
              ((long) info->esp_at_signal & - getpagesize ()))[getpagesize ()];

           but that's wrong, since it tests the stack pointer location, and
           the current stack probe code does not move the stack pointer
           until all probes succeed.

           For now we simply do not attempt any discrimination at all. Note
           that this is quite acceptable, since a "real" SIGSEGV can only
           occur as the result of an erroneous program.  */

        msg = "stack overflow (or erroneous memory access)";
        exception = &storage_error;
      }
      break;

    case SIGBUS:
      exception = &constraint_error;
      msg = "SIGBUS";
      break;

    case SIGFPE:
      exception = &constraint_error;
      msg = "SIGFPE";
      break;

    default:
      exception = &program_error;
      msg = "unhandled signal";
    }
  recurse = 0;

  /* We adjust the interrupted context here (and not in the fallback
     unwinding routine) because recent versions of the Native POSIX
     Thread Library (NPTL) are compiled with unwind information, so
     the fallback routine is never executed for signal frames.  */
  __gnat_adjust_context_for_raise (sig, ucontext);

  Raise_From_Signal_Handler (exception, msg);
}

#if defined (i386) || defined (__x86_64__)
/* This must be in keeping with System.OS_Interface.Alternate_Stack_Size.  */
char __gnat_alternate_stack[16 * 1024]; /* 2 * SIGSTKSZ */
#endif

#ifdef __XENO__
#include <sys/mman.h>
#include <native/task.h>

RT_TASK main_task;
#endif

void
__gnat_install_handler (void)
{
  struct sigaction act;

#ifdef __XENO__
  int prio;

  if (__gl_main_priority == -1)
    prio = 49;
  else
    prio = __gl_main_priority;

  /* Avoid memory swapping for this program */

  mlockall (MCL_CURRENT|MCL_FUTURE);

  /* Turn the current Linux task into a native Xenomai task */

  rt_task_shadow(&main_task, "environment_task", prio, T_FPU);
#endif

  /* Set up signal handler to map synchronous signals to appropriate
     exceptions.  Make sure that the handler isn't interrupted by another
     signal that might cause a scheduling event!  Also setup an alternate
     stack region for the handler execution so that stack overflows can be
     handled properly, avoiding a SEGV generation from stack usage by the
     handler itself.  */

#if defined (i386) || defined (__x86_64__)
  stack_t stack;
  stack.ss_sp = __gnat_alternate_stack;
  stack.ss_size = sizeof (__gnat_alternate_stack);
  stack.ss_flags = 0;
  sigaltstack (&stack, NULL);
#endif

  act.sa_sigaction = __gnat_error_handler;
  act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
  sigemptyset (&act.sa_mask);

  /* Do not install handlers if interrupt state is "System".  */
  if (__gnat_get_interrupt_state (SIGABRT) != 's')
    sigaction (SIGABRT, &act, NULL);
  if (__gnat_get_interrupt_state (SIGFPE) != 's')
    sigaction (SIGFPE,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGILL) != 's')
    sigaction (SIGILL,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGBUS) != 's')
    sigaction (SIGBUS,  &act, NULL);
#if defined (i386) || defined (__x86_64__)
  act.sa_flags |= SA_ONSTACK;
#endif
  if (__gnat_get_interrupt_state (SIGSEGV) != 's')
    sigaction (SIGSEGV, &act, NULL);

  __gnat_handler_installed = 1;
}

/****************/
/* IRIX Section */
/****************/

#elif defined (sgi)

#include <signal.h>
#include <siginfo.h>

#ifndef NULL
#define NULL 0
#endif

#define SIGADAABORT 48
#define SIGNAL_STACK_SIZE 4096
#define SIGNAL_STACK_ALIGNMENT 64

#define Check_Abort_Status     \
                      system__soft_links__check_abort_status
extern int (*Check_Abort_Status) (void);

extern struct Exception_Data _abort_signal;

static void __gnat_error_handler (int, int, sigcontext_t *);

/* We are not setting the SA_SIGINFO bit in the sigaction flags when
   connecting that handler, with the effects described in the sigaction
   man page:

          SA_SIGINFO [...]
          If cleared and the signal is caught, the first argument is
          also the signal number but the second argument is the signal
          code identifying the cause of the signal. The third argument
          points to a sigcontext_t structure containing the receiving
          process's context when the signal was delivered.  */

static void
__gnat_error_handler (int sig, int code, sigcontext_t *sc ATTRIBUTE_UNUSED)
{
  struct Exception_Data *exception;
  const char *msg;

  switch (sig)
    {
    case SIGSEGV:
      if (code == EFAULT)
	{
	  exception = &program_error;
	  msg = "SIGSEGV: (Invalid virtual address)";
	}
      else if (code == ENXIO)
	{
	  exception = &program_error;
	  msg = "SIGSEGV: (Read beyond mapped object)";
	}
      else if (code == ENOSPC)
	{
	  exception = &program_error; /* ??? storage_error ??? */
	  msg = "SIGSEGV: (Autogrow for file failed)";
	}
      else if (code == EACCES || code == EEXIST)
	{
	  /* ??? We handle stack overflows here, some of which do trigger
	         SIGSEGV + EEXIST on Irix 6.5 although EEXIST is not part of
	         the documented valid codes for SEGV in the signal(5) man
	         page.  */

	  /* ??? Re-add smarts to further verify that we launched
		 the stack into a guard page, not an attempt to
		 write to .text or something.  */
	  exception = &storage_error;
	  msg = "SIGSEGV: (stack overflow or erroneous memory access)";
	}
      else
	{
	  /* Just in case the OS guys did it to us again.  Sometimes
	     they fail to document all of the valid codes that are
	     passed to signal handlers, just in case someone depends
	     on knowing all the codes.  */
	  exception = &program_error;
	  msg = "SIGSEGV: (Undocumented reason)";
	}
      break;

    case SIGBUS:
      /* Map all bus errors to Program_Error.  */
      exception = &program_error;
      msg = "SIGBUS";
      break;

    case SIGFPE:
      /* Map all fpe errors to Constraint_Error.  */
      exception = &constraint_error;
      msg = "SIGFPE";
      break;

    case SIGADAABORT:
      if ((*Check_Abort_Status) ())
	{
	  exception = &_abort_signal;
	  msg = "";
	}
      else
	return;

      break;

    default:
      /* Everything else is a Program_Error.  */
      exception = &program_error;
      msg = "unhandled signal";
    }

  Raise_From_Signal_Handler (exception, msg);
}

void
__gnat_install_handler (void)
{
  struct sigaction act;

  /* Setup signal handler to map synchronous signals to appropriate
     exceptions.  Make sure that the handler isn't interrupted by another
     signal that might cause a scheduling event!  */

  act.sa_handler = __gnat_error_handler;
  act.sa_flags = SA_NODEFER + SA_RESTART;
  sigfillset (&act.sa_mask);
  sigemptyset (&act.sa_mask);

  /* Do not install handlers if interrupt state is "System".  */
  if (__gnat_get_interrupt_state (SIGABRT) != 's')
    sigaction (SIGABRT, &act, NULL);
  if (__gnat_get_interrupt_state (SIGFPE) != 's')
    sigaction (SIGFPE,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGILL) != 's')
    sigaction (SIGILL,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGSEGV) != 's')
    sigaction (SIGSEGV, &act, NULL);
  if (__gnat_get_interrupt_state (SIGBUS) != 's')
    sigaction (SIGBUS,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGADAABORT) != 's')
    sigaction (SIGADAABORT,  &act, NULL);

  __gnat_handler_installed = 1;
}

/*******************/
/* LynxOS Section */
/*******************/

#elif defined (__Lynx__)

#include <signal.h>
#include <unistd.h>

static void
__gnat_error_handler (int sig)
{
  struct Exception_Data *exception;
  const char *msg;

  switch(sig)
  {
    case SIGFPE:
      exception = &constraint_error;
      msg = "SIGFPE";
      break;
    case SIGILL:
      exception = &constraint_error;
      msg = "SIGILL";
      break;
    case SIGSEGV:
      exception = &storage_error;
      msg = "stack overflow or erroneous memory access";
      break;
    case SIGBUS:
      exception = &constraint_error;
      msg = "SIGBUS";
      break;
    default:
      exception = &program_error;
      msg = "unhandled signal";
    }

    Raise_From_Signal_Handler(exception, msg);
}

void
__gnat_install_handler(void)
{
  struct sigaction act;

  act.sa_handler = __gnat_error_handler;
  act.sa_flags = 0x0;
  sigemptyset (&act.sa_mask);

  /* Do not install handlers if interrupt state is "System".  */
  if (__gnat_get_interrupt_state (SIGFPE) != 's')
    sigaction (SIGFPE,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGILL) != 's')
    sigaction (SIGILL,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGSEGV) != 's')
    sigaction (SIGSEGV, &act, NULL);
  if (__gnat_get_interrupt_state (SIGBUS) != 's')
    sigaction (SIGBUS,  &act, NULL);

  __gnat_handler_installed = 1;
}

/*******************/
/* Solaris Section */
/*******************/

#elif defined (sun) && defined (__SVR4) && !defined (__vxworks)

#include <signal.h>
#include <siginfo.h>
#include <sys/ucontext.h>
#include <sys/regset.h>

/* The code below is common to SPARC and x86.  Beware of the delay slot
   differences for signal context adjustments.  */

#if defined (__sparc)
#define RETURN_ADDR_OFFSET 8
#else
#define RETURN_ADDR_OFFSET 0
#endif

/* Likewise regarding how the "instruction pointer" register slot can
   be identified in signal machine contexts.  We have either "REG_PC"
   or "PC" at hand, depending on the target CPU and Solaris version.  */

#if !defined (REG_PC)
#define REG_PC PC
#endif

static void __gnat_error_handler (int, siginfo_t *, ucontext_t *);

static void
__gnat_error_handler (int sig, siginfo_t *sip, ucontext_t *uctx)
{
  struct Exception_Data *exception;
  static int recurse = 0;
  const char *msg;

  /* If this was an explicit signal from a "kill", just resignal it.  */
  if (SI_FROMUSER (sip))
    {
      signal (sig, SIG_DFL);
      kill (getpid(), sig);
    }

  /* Otherwise, treat it as something we handle.  */
  switch (sig)
    {
    case SIGSEGV:
      /* If the problem was permissions, this is a constraint error.
	 Likewise if the failing address isn't maximally aligned or if
	 we've recursed.

	 ??? Using a static variable here isn't task-safe, but it's
	 much too hard to do anything else and we're just determining
	 which exception to raise.  */
      if (sip->si_code == SEGV_ACCERR
	  || (((long) sip->si_addr) & 3) != 0
	  || recurse)
	{
	  exception = &constraint_error;
	  msg = "SIGSEGV";
	}
      else
	{
	  /* See if the page before the faulting page is accessible.  Do that
	     by trying to access it.  We'd like to simply try to access
	     4096 + the faulting address, but it's not guaranteed to be
	     the actual address, just to be on the same page.  */
	  recurse++;
	  ((volatile char *)
	   ((long) sip->si_addr & - getpagesize ()))[getpagesize ()];
	  exception = &storage_error;
	  msg = "stack overflow (or erroneous memory access)";
	}
      break;

    case SIGBUS:
      exception = &program_error;
      msg = "SIGBUS";
      break;

    case SIGFPE:
      exception = &constraint_error;
      msg = "SIGFPE";
      break;

    default:
      exception = &program_error;
      msg = "unhandled signal";
    }

  recurse = 0;

  Raise_From_Signal_Handler (exception, msg);
}

void
__gnat_install_handler (void)
{
  struct sigaction act;

  /* Set up signal handler to map synchronous signals to appropriate
     exceptions.  Make sure that the handler isn't interrupted by another
     signal that might cause a scheduling event!  */

  act.sa_handler = __gnat_error_handler;
  act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
  sigemptyset (&act.sa_mask);

  /* Do not install handlers if interrupt state is "System".  */
  if (__gnat_get_interrupt_state (SIGABRT) != 's')
    sigaction (SIGABRT, &act, NULL);
  if (__gnat_get_interrupt_state (SIGFPE) != 's')
    sigaction (SIGFPE,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGSEGV) != 's')
    sigaction (SIGSEGV, &act, NULL);
  if (__gnat_get_interrupt_state (SIGBUS) != 's')
    sigaction (SIGBUS,  &act, NULL);

  __gnat_handler_installed = 1;
}

/***************/
/* VMS Section */
/***************/

#elif defined (VMS)

/* Routine called from binder to override default feature values. */
void __gnat_set_features ();
int __gnat_features_set = 0;

long __gnat_error_handler (int *, void *);

#ifdef __IA64
#define lib_get_curr_invo_context LIB$I64_GET_CURR_INVO_CONTEXT
#define lib_get_prev_invo_context LIB$I64_GET_PREV_INVO_CONTEXT
#define lib_get_invo_handle LIB$I64_GET_INVO_HANDLE
#else
#define lib_get_curr_invo_context LIB$GET_CURR_INVO_CONTEXT
#define lib_get_prev_invo_context LIB$GET_PREV_INVO_CONTEXT
#define lib_get_invo_handle LIB$GET_INVO_HANDLE
#endif

#if defined (IN_RTS) && !defined (__IA64)

/* The prehandler actually gets control first on a condition.  It swaps the
   stack pointer and calls the handler (__gnat_error_handler).  */
extern long __gnat_error_prehandler (void);

extern char *__gnat_error_prehandler_stack;   /* Alternate signal stack */
#endif

/* Define macro symbols for the VMS conditions that become Ada exceptions.
   Most of these are also defined in the header file ssdef.h which has not
   yet been converted to be recognized by GNU C.  */

/* Defining these as macros, as opposed to external addresses, allows
   them to be used in a case statement below.  */
#define SS$_ACCVIO            12
#define SS$_HPARITH         1284
#define SS$_STKOVF          1364
#define SS$_RESIGNAL        2328

/* These codes are in standard message libraries.  */
extern int CMA$_EXIT_THREAD;
extern int SS$_DEBUG;
extern int SS$_INTDIV;
extern int LIB$_KEYNOTFOU;
extern int LIB$_ACTIMAGE;
extern int MTH$_FLOOVEMAT;       /* Some ACVC_21 CXA tests */

/* These codes are non standard, which is to say the author is
   not sure if they are defined in the standard message libraries
   so keep them as macros for now.  */
#define RDB$_STREAM_EOF 20480426
#define FDL$_UNPRIKW 11829410

struct cond_except {
  const int *cond;
  const struct Exception_Data *except;
};

struct descriptor_s {unsigned short len, mbz; __char_ptr32 adr; };

/* Conditions that don't have an Ada exception counterpart must raise
   Non_Ada_Error.  Since this is defined in s-auxdec, it should only be
   referenced by user programs, not the compiler or tools.  Hence the
   #ifdef IN_RTS.  */

#ifdef IN_RTS

#define Status_Error ada__io_exceptions__status_error
extern struct Exception_Data Status_Error;

#define Mode_Error ada__io_exceptions__mode_error
extern struct Exception_Data Mode_Error;

#define Name_Error ada__io_exceptions__name_error
extern struct Exception_Data Name_Error;

#define Use_Error ada__io_exceptions__use_error
extern struct Exception_Data Use_Error;

#define Device_Error ada__io_exceptions__device_error
extern struct Exception_Data Device_Error;

#define End_Error ada__io_exceptions__end_error
extern struct Exception_Data End_Error;

#define Data_Error ada__io_exceptions__data_error
extern struct Exception_Data Data_Error;

#define Layout_Error ada__io_exceptions__layout_error
extern struct Exception_Data Layout_Error;

#define Non_Ada_Error system__aux_dec__non_ada_error
extern struct Exception_Data Non_Ada_Error;

#define Coded_Exception system__vms_exception_table__coded_exception
extern struct Exception_Data *Coded_Exception (Exception_Code);

#define Base_Code_In system__vms_exception_table__base_code_in
extern Exception_Code Base_Code_In (Exception_Code);

/* DEC Ada exceptions are not defined in a header file, so they
   must be declared as external addresses.  */

extern int ADA$_PROGRAM_ERROR;
extern int ADA$_LOCK_ERROR;
extern int ADA$_EXISTENCE_ERROR;
extern int ADA$_KEY_ERROR;
extern int ADA$_KEYSIZERR;
extern int ADA$_STAOVF;
extern int ADA$_CONSTRAINT_ERRO;
extern int ADA$_IOSYSFAILED;
extern int ADA$_LAYOUT_ERROR;
extern int ADA$_STORAGE_ERROR;
extern int ADA$_DATA_ERROR;
extern int ADA$_DEVICE_ERROR;
extern int ADA$_END_ERROR;
extern int ADA$_MODE_ERROR;
extern int ADA$_NAME_ERROR;
extern int ADA$_STATUS_ERROR;
extern int ADA$_NOT_OPEN;
extern int ADA$_ALREADY_OPEN;
extern int ADA$_USE_ERROR;
extern int ADA$_UNSUPPORTED;
extern int ADA$_FAC_MODE_MISMAT;
extern int ADA$_ORG_MISMATCH;
extern int ADA$_RFM_MISMATCH;
extern int ADA$_RAT_MISMATCH;
extern int ADA$_MRS_MISMATCH;
extern int ADA$_MRN_MISMATCH;
extern int ADA$_KEY_MISMATCH;
extern int ADA$_MAXLINEXC;
extern int ADA$_LINEXCMRS;

/* DEC Ada specific conditions.  */
static const struct cond_except dec_ada_cond_except_table [] = {
  {&ADA$_PROGRAM_ERROR,   &program_error},
  {&ADA$_USE_ERROR,       &Use_Error},
  {&ADA$_KEYSIZERR,       &program_error},
  {&ADA$_STAOVF,          &storage_error},
  {&ADA$_CONSTRAINT_ERRO, &constraint_error},
  {&ADA$_IOSYSFAILED,     &Device_Error},
  {&ADA$_LAYOUT_ERROR,    &Layout_Error},
  {&ADA$_STORAGE_ERROR,   &storage_error},
  {&ADA$_DATA_ERROR,      &Data_Error},
  {&ADA$_DEVICE_ERROR,    &Device_Error},
  {&ADA$_END_ERROR,       &End_Error},
  {&ADA$_MODE_ERROR,      &Mode_Error},
  {&ADA$_NAME_ERROR,      &Name_Error},
  {&ADA$_STATUS_ERROR,    &Status_Error},
  {&ADA$_NOT_OPEN,        &Use_Error},
  {&ADA$_ALREADY_OPEN,    &Use_Error},
  {&ADA$_USE_ERROR,       &Use_Error},
  {&ADA$_UNSUPPORTED,     &Use_Error},
  {&ADA$_FAC_MODE_MISMAT, &Use_Error},
  {&ADA$_ORG_MISMATCH,    &Use_Error},
  {&ADA$_RFM_MISMATCH,    &Use_Error},
  {&ADA$_RAT_MISMATCH,    &Use_Error},
  {&ADA$_MRS_MISMATCH,    &Use_Error},
  {&ADA$_MRN_MISMATCH,    &Use_Error},
  {&ADA$_KEY_MISMATCH,    &Use_Error},
  {&ADA$_MAXLINEXC,       &constraint_error},
  {&ADA$_LINEXCMRS,       &constraint_error},
  {0,                     0}
};

#if 0
   /* Already handled by a pragma Import_Exception
      in Aux_IO_Exceptions */
  {&ADA$_LOCK_ERROR,      &Lock_Error},
  {&ADA$_EXISTENCE_ERROR, &Existence_Error},
  {&ADA$_KEY_ERROR,       &Key_Error},
#endif

#endif /* IN_RTS */

/* Non-DEC Ada specific conditions.  We could probably also put
   SS$_HPARITH here and possibly SS$_ACCVIO, SS$_STKOVF.  */
static const struct cond_except cond_except_table [] = {
  {&MTH$_FLOOVEMAT, &constraint_error},
  {&SS$_INTDIV,     &constraint_error},
  {0,               0}
};

/* To deal with VMS conditions and their mapping to Ada exceptions,
   the __gnat_error_handler routine below is installed as an exception
   vector having precedence over DEC frame handlers.  Some conditions
   still need to be handled by such handlers, however, in which case
   __gnat_error_handler needs to return SS$_RESIGNAL.  Consider for
   instance the use of a third party library compiled with DECAda and
   performing its own exception handling internally.

   To allow some user-level flexibility, which conditions should be
   resignaled is controlled by a predicate function, provided with the
   condition value and returning a boolean indication stating whether
   this condition should be resignaled or not.

   That predicate function is called indirectly, via a function pointer,
   by __gnat_error_handler, and changing that pointer is allowed to the
   the user code by way of the __gnat_set_resignal_predicate interface.

   The user level function may then implement what it likes, including
   for instance the maintenance of a dynamic data structure if the set
   of to be resignalled conditions has to change over the program's
   lifetime.

   ??? This is not a perfect solution to deal with the possible
   interactions between the GNAT and the DECAda exception handling
   models and better (more general) schemes are studied.  This is so
   just provided as a convenient workaround in the meantime, and
   should be use with caution since the implementation has been kept
   very simple.  */

typedef int
resignal_predicate (int code);

const int *cond_resignal_table [] = {
  &CMA$_EXIT_THREAD,
  &SS$_DEBUG,
  &LIB$_KEYNOTFOU,
  &LIB$_ACTIMAGE,
  (int *) RDB$_STREAM_EOF,
  (int *) FDL$_UNPRIKW,
  0
};

const int facility_resignal_table [] = {
  0x1380000, /* RDB */
  0x2220000, /* SQL */
  0
};

/* Default GNAT predicate for resignaling conditions.  */

static int
__gnat_default_resignal_p (int code)
{
  int i, iexcept;

  for (i = 0; facility_resignal_table [i]; i++)
    if ((code & 0xfff0000) == facility_resignal_table [i])
      return 1;

  for (i = 0, iexcept = 0;
       cond_resignal_table [i] &&
       !(iexcept = LIB$MATCH_COND (&code, &cond_resignal_table [i]));
       i++);

  return iexcept;
}

/* Static pointer to predicate that the __gnat_error_handler exception
   vector invokes to determine if it should resignal a condition.  */

static resignal_predicate * __gnat_resignal_p = __gnat_default_resignal_p;

/* User interface to change the predicate pointer to PREDICATE. Reset to
   the default if PREDICATE is null.  */

void
__gnat_set_resignal_predicate (resignal_predicate * predicate)
{
  if (predicate == 0)
    __gnat_resignal_p = __gnat_default_resignal_p;
  else
    __gnat_resignal_p = predicate;
}

/* Should match System.Parameters.Default_Exception_Msg_Max_Length.  */
#define Default_Exception_Msg_Max_Length 512

/* Action routine for SYS$PUTMSG. There may be multiple
   conditions, each with text to be appended to MESSAGE
   and separated by line termination.  */

static int
copy_msg (msgdesc, message)
     struct descriptor_s *msgdesc;
     char *message;
{
  int len = strlen (message);
  int copy_len;

  /* Check for buffer overflow and skip.  */
  if (len > 0 && len <= Default_Exception_Msg_Max_Length - 3)
    {
      strcat (message, "\r\n");
      len += 2;
    }

  /* Check for buffer overflow and truncate if necessary.  */
  copy_len = (len + msgdesc->len <= Default_Exception_Msg_Max_Length - 1 ?
	      msgdesc->len :
	      Default_Exception_Msg_Max_Length - 1 - len);
  strncpy (&message [len], msgdesc->adr, copy_len);
  message [len + copy_len] = 0;

  return 0;
}

long
__gnat_handle_vms_condition (int *sigargs, void *mechargs)
{
  struct Exception_Data *exception = 0;
  Exception_Code base_code;
  struct descriptor_s gnat_facility = {4,0,"GNAT"};
  char message [Default_Exception_Msg_Max_Length];

  const char *msg = "";

  /* Check for conditions to resignal which aren't effected by pragma
     Import_Exception.  */
  if (__gnat_resignal_p (sigargs [1]))
    return SS$_RESIGNAL;

#ifdef IN_RTS
  /* See if it's an imported exception.  Beware that registered exceptions
     are bound to their base code, with the severity bits masked off.  */
  base_code = Base_Code_In ((Exception_Code) sigargs [1]);
  exception = Coded_Exception (base_code);

  if (exception)
    {
      message [0] = 0;

      /* Subtract PC & PSL fields which messes with PUTMSG.  */
      sigargs [0] -= 2;
      SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
      sigargs [0] += 2;
      msg = message;

      exception->Name_Length = 19;
      /* ??? The full name really should be get sys$getmsg returns.  */
      exception->Full_Name = "IMPORTED_EXCEPTION";
      exception->Import_Code = base_code;

#ifdef __IA64
      /* Do not adjust the program counter as already points to the next
	 instruction (just after the call to LIB$STOP).  */
      Raise_From_Signal_Handler (exception, msg);
#endif
    }
#endif

  if (exception == 0)
    switch (sigargs[1])
      {
      case SS$_ACCVIO:
        if (sigargs[3] == 0)
	  {
	    exception = &constraint_error;
	    msg = "access zero";
	  }
	else
	  {
	    exception = &storage_error;
	    msg = "stack overflow (or erroneous memory access)";
	  }
	__gnat_adjust_context_for_raise (0, (void *)mechargs);
	break;

      case SS$_STKOVF:
	exception = &storage_error;
	msg = "stack overflow";
	__gnat_adjust_context_for_raise (0, (void *)mechargs);
	break;

      case SS$_HPARITH:
#ifndef IN_RTS
	return SS$_RESIGNAL; /* toplev.c handles for compiler */
#else
	exception = &constraint_error;
	msg = "arithmetic error";
#ifndef __alpha__
	/* No need to adjust pc on Alpha: the pc is already on the instruction
	   after the trapping one.  */
	__gnat_adjust_context_for_raise (0, (void *)mechargs);
#endif
#endif
	break;

      default:
#ifdef IN_RTS
	{
	  int i;

	  /* Scan the DEC Ada exception condition table for a match and fetch
	     the associated GNAT exception pointer.  */
	  for (i = 0;
	       dec_ada_cond_except_table [i].cond &&
	       !LIB$MATCH_COND (&sigargs [1],
			        &dec_ada_cond_except_table [i].cond);
	       i++);
	  exception = (struct Exception_Data *)
	    dec_ada_cond_except_table [i].except;

	  if (!exception)
	    {
	      /* Scan the VMS standard condition table for a match and fetch
		 the associated GNAT exception pointer.  */
	      for (i = 0;
		   cond_except_table [i].cond &&
		   !LIB$MATCH_COND (&sigargs [1], &cond_except_table [i].cond);
		   i++);
	      exception = (struct Exception_Data *)
		cond_except_table [i].except;

	      if (!exception)
		/* User programs expect Non_Ada_Error to be raised, reference
		   DEC Ada test CXCONDHAN.  */
		exception = &Non_Ada_Error;
	    }
	}
#else
	exception = &program_error;
#endif
	message [0] = 0;
	/* Subtract PC & PSL fields which messes with PUTMSG.  */
	sigargs [0] -= 2;
	SYS$PUTMSG (sigargs, copy_msg, &gnat_facility, message);
	sigargs [0] += 2;
	msg = message;
	break;
      }

  Raise_From_Signal_Handler (exception, msg);
}

long
__gnat_error_handler (int *sigargs, void *mechargs)
{
  return __gnat_handle_vms_condition (sigargs, mechargs);
}

void
__gnat_install_handler (void)
{
  long prvhnd ATTRIBUTE_UNUSED;

#if !defined (IN_RTS)
  SYS$SETEXV (1, __gnat_error_handler, 3, &prvhnd);
#endif

  /* On alpha-vms, we avoid the global vector annoyance thanks to frame based
     handlers to turn conditions into exceptions since GCC 3.4.  The global
     vector is still required for earlier GCC versions.  We're resorting to
     the __gnat_error_prehandler assembly function in this case.  */

#if defined (IN_RTS) && defined (__alpha__)
  if ((__GNUC__ * 10 + __GNUC_MINOR__) < 34)
    {
      char * c = (char *) xmalloc (2049);

      __gnat_error_prehandler_stack = &c[2048];
      SYS$SETEXV (1, __gnat_error_prehandler, 3, &prvhnd);
    }
#endif

  __gnat_handler_installed = 1;
}

/* __gnat_adjust_context_for_raise for Alpha - see comments along with the
   default version later in this file.  */

#if defined (IN_RTS) && defined (__alpha__)

#include <vms/chfctxdef.h>
#include <vms/chfdef.h>

#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE

void
__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
{
  /* Add one to the address of the instruction signaling the condition,
     located in the sigargs array.  */

  CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;
  CHF$SIGNAL_ARRAY * sigargs
    = (CHF$SIGNAL_ARRAY *) mechargs->chf$q_mch_sig_addr;

  int vcount = sigargs->chf$is_sig_args;
  int * pc_slot = & (&sigargs->chf$l_sig_name)[vcount-2];

  (*pc_slot) ++;
}

#endif

/* __gnat_adjust_context_for_raise for ia64.  */

#if defined (IN_RTS) && defined (__IA64)

#include <vms/chfctxdef.h>
#include <vms/chfdef.h>

#define HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE

typedef unsigned long long u64;

void
__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED, void *ucontext)
{
  /* Add one to the address of the instruction signaling the condition,
     located in the 64bits sigargs array.  */

  CHF$MECH_ARRAY * mechargs = (CHF$MECH_ARRAY *) ucontext;

  CHF64$SIGNAL_ARRAY *chfsig64
    = (CHF64$SIGNAL_ARRAY *) mechargs->chf$ph_mch_sig64_addr;

  u64 * post_sigarray
    = (u64 *)chfsig64 + 1 + chfsig64->chf64$l_sig_args;

  u64 * ih_pc_loc = post_sigarray - 2;

  (*ih_pc_loc) ++;
}

#endif

/* Feature logical name and global variable address pair */
struct feature {char *name; int* gl_addr;};

/* Default values for GNAT features set by environment. */
int __gl_no_malloc_64 = 0;

/* Array feature logical names and global variable addresses */
static struct feature features[] = {
  {"GNAT$NO_MALLOC_64", &__gl_no_malloc_64},
  {0, 0}
};

void __gnat_set_features ()
{
  struct descriptor_s name_desc, result_desc;
  int i, status;
  unsigned short rlen;

#define MAXEQUIV 10
  char buff [MAXEQUIV];

  /* Loop through features array and test name for enable/disable */
  for (i=0; features [i].name; i++)
    {
       name_desc.len = strlen (features [i].name);
       name_desc.mbz = 0;
       name_desc.adr = features [i].name;

       result_desc.len = MAXEQUIV - 1;
       result_desc.mbz = 0;
       result_desc.adr = buff;

       status = LIB$GET_LOGICAL (&name_desc, &result_desc, &rlen);

       if (((status & 1) == 1) && (rlen < MAXEQUIV))
         buff [rlen] = 0;
       else
         strcpy (buff, "");

       if (strcmp (buff, "ENABLE") == 0)
          *features [i].gl_addr = 1;
       else if (strcmp (buff, "DISABLE") == 0)
          *features [i].gl_addr = 0;
    }

    __gnat_features_set = 1;
}

/*******************/
/* FreeBSD Section */
/*******************/

#elif defined (__FreeBSD__)

#include <signal.h>
#include <sys/ucontext.h>
#include <unistd.h>

static void __gnat_error_handler (int, siginfo_t *, ucontext_t *);

static void
__gnat_error_handler (int sig, siginfo_t *info __attribute__ ((unused)),
		      ucontext_t *ucontext)
{
  struct Exception_Data *exception;
  const char *msg;

  switch (sig)
    {
    case SIGFPE:
      exception = &constraint_error;
      msg = "SIGFPE";
      break;

    case SIGILL:
      exception = &constraint_error;
      msg = "SIGILL";
      break;

    case SIGSEGV:
      exception = &storage_error;
      msg = "stack overflow or erroneous memory access";
      break;

    case SIGBUS:
      exception = &constraint_error;
      msg = "SIGBUS";
      break;

    default:
      exception = &program_error;
      msg = "unhandled signal";
    }

  Raise_From_Signal_Handler (exception, msg);
}

void
__gnat_install_handler ()
{
  struct sigaction act;

  /* Set up signal handler to map synchronous signals to appropriate
     exceptions.  Make sure that the handler isn't interrupted by another
     signal that might cause a scheduling event!  */

  act.sa_sigaction
    = (void (*)(int, struct __siginfo *, void*)) __gnat_error_handler;
  act.sa_flags = SA_NODEFER | SA_RESTART | SA_SIGINFO;
  (void) sigemptyset (&act.sa_mask);

  (void) sigaction (SIGILL,  &act, NULL);
  (void) sigaction (SIGFPE,  &act, NULL);
  (void) sigaction (SIGSEGV, &act, NULL);
  (void) sigaction (SIGBUS,  &act, NULL);

  __gnat_handler_installed = 1;
}

/*******************/
/* VxWorks Section */
/*******************/

#elif defined(__vxworks)

#include <signal.h>
#include <taskLib.h>

#ifndef __RTP__
#include <intLib.h>
#include <iv.h>
#endif

#ifdef VTHREADS
#include "private/vThreadsP.h"
#endif

void __gnat_error_handler (int, void *, struct sigcontext *);

#ifndef __RTP__

/* Directly vectored Interrupt routines are not supported when using RTPs.  */

extern int __gnat_inum_to_ivec (int);

/* This is needed by the GNAT run time to handle Vxworks interrupts.  */
int
__gnat_inum_to_ivec (int num)
{
  return INUM_TO_IVEC (num);
}
#endif

#if !defined(__alpha_vxworks) && (_WRS_VXWORKS_MAJOR != 6) && !defined(__RTP__)

/* getpid is used by s-parint.adb, but is not defined by VxWorks, except
   on Alpha VxWorks and VxWorks 6.x (including RTPs).  */

extern long getpid (void);

long
getpid (void)
{
  return taskIdSelf ();
}
#endif

/* VxWorks expects the field excCnt to be zeroed when a signal is handled.
   The VxWorks version of longjmp does this; GCC's builtin_longjmp doesn't.  */
void
__gnat_clear_exception_count (void)
{
#ifdef VTHREADS
  WIND_TCB *currentTask = (WIND_TCB *) taskIdSelf();

  currentTask->vThreads.excCnt = 0;
#endif
}

/* Handle different SIGnal to exception mappings in different VxWorks
   versions.   */
static void
__gnat_map_signal (int sig)
{
  struct Exception_Data *exception;
  const char *msg;

  switch (sig)
    {
    case SIGFPE:
      exception = &constraint_error;
      msg = "SIGFPE";
      break;
#ifdef VTHREADS
    case SIGILL:
      exception = &constraint_error;
      msg = "Floating point exception or SIGILL";
      break;
    case SIGSEGV:
      exception = &storage_error;
      msg = "SIGSEGV: possible stack overflow";
      break;
    case SIGBUS:
      exception = &storage_error;
      msg = "SIGBUS: possible stack overflow";
      break;
#else
#ifdef __RTP__
    /* In RTP mode a SIGSEGV is most likely due to a stack overflow,
       since stack checking uses the probing mechanism.  */
    case SIGILL:
      exception = &constraint_error;
      msg = "SIGILL";
      break;
    case SIGSEGV:
      exception = &storage_error;
      msg = "SIGSEGV: possible stack overflow";
      break;
#else
    /* In kernel mode a SIGILL is most likely due to a stack overflow,
       since stack checking uses the stack limit mechanism.  */
    case SIGILL:
      exception = &storage_error;
      msg = "SIGILL: possible stack overflow";
      break;
    case SIGSEGV:
      exception = &program_error;
      msg = "SIGSEGV";
      break;
#endif
    case SIGBUS:
      exception = &program_error;
      msg = "SIGBUS";
      break;
#endif
    default:
      exception = &program_error;
      msg = "unhandled signal";
    }

  __gnat_clear_exception_count ();
  Raise_From_Signal_Handler (exception, msg);
}

/* Tasking and Non-tasking signal handler.  Map SIGnal to Ada exception
   propagation after the required low level adjustments.  */

void
__gnat_error_handler (int sig, void * si ATTRIBUTE_UNUSED,
		      struct sigcontext * sc)
{
  sigset_t mask;

  /* VxWorks will always mask out the signal during the signal handler and
     will reenable it on a longjmp.  GNAT does not generate a longjmp to
     return from a signal handler so the signal will still be masked unless
     we unmask it.  */
  sigprocmask (SIG_SETMASK, NULL, &mask);
  sigdelset (&mask, sig);
  sigprocmask (SIG_SETMASK, &mask, NULL);

  __gnat_map_signal (sig);
}

void
__gnat_install_handler (void)
{
  struct sigaction act;

  /* Setup signal handler to map synchronous signals to appropriate
     exceptions.  Make sure that the handler isn't interrupted by another
     signal that might cause a scheduling event!  */

  act.sa_handler = __gnat_error_handler;
  act.sa_flags = SA_SIGINFO | SA_ONSTACK;
  sigemptyset (&act.sa_mask);

  /* For VxWorks, install all signal handlers, since pragma Interrupt_State
     applies to vectored hardware interrupts, not signals.  */
  sigaction (SIGFPE,  &act, NULL);
  sigaction (SIGILL,  &act, NULL);
  sigaction (SIGSEGV, &act, NULL);
  sigaction (SIGBUS,  &act, NULL);

  __gnat_handler_installed = 1;
}

#define HAVE_GNAT_INIT_FLOAT

void
__gnat_init_float (void)
{
  /* Disable overflow/underflow exceptions on the PPC processor, needed
     to get correct Ada semantics.  Note that for AE653 vThreads, the HW
     overflow settings are an OS configuration issue.  The instructions
     below have no effect.  */
#if defined (_ARCH_PPC) && !defined (_SOFT_FLOAT) && !defined (VTHREADS)
  asm ("mtfsb0 25");
  asm ("mtfsb0 26");
#endif

#if (defined (__i386__) || defined (i386)) && !defined (VTHREADS)
  /* This is used to properly initialize the FPU on an x86 for each
     process thread.  */
  asm ("finit");
#endif

  /* Similarly for SPARC64.  Achieved by masking bits in the Trap Enable Mask
     field of the Floating-point Status Register (see the SPARC Architecture
     Manual Version 9, p 48).  */
#if defined (sparc64)

#define FSR_TEM_NVM (1 << 27)  /* Invalid operand  */
#define FSR_TEM_OFM (1 << 26)  /* Overflow  */
#define FSR_TEM_UFM (1 << 25)  /* Underflow  */
#define FSR_TEM_DZM (1 << 24)  /* Division by Zero  */
#define FSR_TEM_NXM (1 << 23)  /* Inexact result  */
  {
    unsigned int fsr;

    __asm__("st %%fsr, %0" : "=m" (fsr));
    fsr &= ~(FSR_TEM_OFM | FSR_TEM_UFM);
    __asm__("ld %0, %%fsr" : : "m" (fsr));
  }
#endif
}

/* This subprogram is called by System.Task_Primitives.Operations.Enter_Task
   (if not null) when a new task is created.  It is initialized by
   System.Stack_Checking.Operations.Initialize_Stack_Limit.
   The use of a hook avoids to drag stack checking subprograms if stack
   checking is not used.  */
void (*__gnat_set_stack_limit_hook)(void) = (void (*)(void))0;


/******************/
/* NetBSD Section */
/******************/

#elif defined(__NetBSD__)

#include <signal.h>
#include <unistd.h>

static void
__gnat_error_handler (int sig)
{
  struct Exception_Data *exception;
  const char *msg;

  switch(sig)
  {
    case SIGFPE:
      exception = &constraint_error;
      msg = "SIGFPE";
      break;
    case SIGILL:
      exception = &constraint_error;
      msg = "SIGILL";
      break;
    case SIGSEGV:
      exception = &storage_error;
      msg = "stack overflow or erroneous memory access";
      break;
    case SIGBUS:
      exception = &constraint_error;
      msg = "SIGBUS";
      break;
    default:
      exception = &program_error;
      msg = "unhandled signal";
    }

    Raise_From_Signal_Handler(exception, msg);
}

void
__gnat_install_handler(void)
{
  struct sigaction act;

  act.sa_handler = __gnat_error_handler;
  act.sa_flags = SA_NODEFER | SA_RESTART;
  sigemptyset (&act.sa_mask);

  /* Do not install handlers if interrupt state is "System".  */
  if (__gnat_get_interrupt_state (SIGFPE) != 's')
    sigaction (SIGFPE,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGILL) != 's')
    sigaction (SIGILL,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGSEGV) != 's')
    sigaction (SIGSEGV, &act, NULL);
  if (__gnat_get_interrupt_state (SIGBUS) != 's')
    sigaction (SIGBUS,  &act, NULL);

  __gnat_handler_installed = 1;
}

/*******************/
/* OpenBSD Section */
/*******************/

#elif defined(__OpenBSD__)

#include <signal.h>
#include <unistd.h>

static void
__gnat_error_handler (int sig)
{
  struct Exception_Data *exception;
  const char *msg;

  switch(sig)
  {
    case SIGFPE:
      exception = &constraint_error;
      msg = "SIGFPE";
      break;
    case SIGILL:
      exception = &constraint_error;
      msg = "SIGILL";
      break;
    case SIGSEGV:
      exception = &storage_error;
      msg = "stack overflow or erroneous memory access";
      break;
    case SIGBUS:
      exception = &constraint_error;
      msg = "SIGBUS";
      break;
    default:
      exception = &program_error;
      msg = "unhandled signal";
    }

    Raise_From_Signal_Handler(exception, msg);
}

void
__gnat_install_handler(void)
{
  struct sigaction act;

  act.sa_handler = __gnat_error_handler;
  act.sa_flags = SA_NODEFER | SA_RESTART;
  sigemptyset (&act.sa_mask);

  /* Do not install handlers if interrupt state is "System" */
  if (__gnat_get_interrupt_state (SIGFPE) != 's')
    sigaction (SIGFPE,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGILL) != 's')
    sigaction (SIGILL,  &act, NULL);
  if (__gnat_get_interrupt_state (SIGSEGV) != 's')
    sigaction (SIGSEGV, &act, NULL);
  if (__gnat_get_interrupt_state (SIGBUS) != 's')
    sigaction (SIGBUS,  &act, NULL);

  __gnat_handler_installed = 1;
}

#else

/* For all other versions of GNAT, the handler does nothing.  */

/*******************/
/* Default Section */
/*******************/

void
__gnat_install_handler (void)
{
  __gnat_handler_installed = 1;
}

#endif

/*********************/
/* __gnat_init_float */
/*********************/

/* This routine is called as each process thread is created, for possible
   initialization of the FP processor.  This version is used under INTERIX,
   WIN32 and could be used under OS/2.  */

#if defined (_WIN32) || defined (__INTERIX) || defined (__EMX__) \
  || defined (__Lynx__) || defined(__NetBSD__) || defined(__FreeBSD__) \
  || defined (__OpenBSD__)

#define HAVE_GNAT_INIT_FLOAT

void
__gnat_init_float (void)
{
#if defined (__i386__) || defined (i386)

  /* This is used to properly initialize the FPU on an x86 for each
     process thread.  */

  asm ("finit");

#endif  /* Defined __i386__ */
}
#endif

#ifndef HAVE_GNAT_INIT_FLOAT

/* All targets without a specific __gnat_init_float will use an empty one.  */
void
__gnat_init_float (void)
{
}
#endif

/***********************************/
/* __gnat_adjust_context_for_raise */
/***********************************/

#ifndef HAVE_GNAT_ADJUST_CONTEXT_FOR_RAISE

/* All targets without a specific version will use an empty one.  */

/* Given UCONTEXT a pointer to a context structure received by a signal
   handler for SIGNO, perform the necessary adjustments to let the handler
   raise an exception.  Calls to this routine are not conditioned by the
   propagation scheme in use.  */

void
__gnat_adjust_context_for_raise (int signo ATTRIBUTE_UNUSED,
				 void *ucontext ATTRIBUTE_UNUSED)
{
  /* We used to compensate here for the raised from call vs raised from signal
     exception discrepancy with the GCC ZCX scheme, but this is now dealt with
     generically (except for the Alpha and IA-64), see GCC PR other/26208.

     *** Call vs signal exception discrepancy with GCC ZCX scheme ***

     The GCC unwinder expects to be dealing with call return addresses, since
     this is the "nominal" case of what we retrieve while unwinding a regular
     call chain.

     To evaluate if a handler applies at some point identified by a return
     address, the propagation engine needs to determine what region the
     corresponding call instruction pertains to.  Because the return address
     may not be attached to the same region as the call, the unwinder always
     subtracts "some" amount from a return address to search the region
     tables, amount chosen to ensure that the resulting address is inside the
     call instruction.

     When we raise an exception from a signal handler, e.g. to transform a
     SIGSEGV into Storage_Error, things need to appear as if the signal
     handler had been "called" by the instruction which triggered the signal,
     so that exception handlers that apply there are considered.  What the
     unwinder will retrieve as the return address from the signal handler is
     what it will find as the faulting instruction address in the signal
     context pushed by the kernel.  Leaving this address untouched looses, if
     the triggering instruction happens to be the very first of a region, as
     the later adjustments performed by the unwinder would yield an address
     outside that region.  We need to compensate for the unwinder adjustments
     at some point, and this is what this routine is expected to do.

     signo is passed because on some targets for some signals the PC in
     context points to the instruction after the faulting one, in which case
     the unwinder adjustment is still desired.  */
}

#endif