aboutsummaryrefslogtreecommitdiff
path: root/gdb/main.c
blob: deaf6240ef980497271acb6eebd1aab6a1da12d3 (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
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
/* Top level `main' program for GDB, the GNU debugger.
   Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992
   Free Software Foundation, Inc.

This file is part of GDB.

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

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

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "defs.h"
#include "gdbcmd.h"
#include "call-cmds.h"
#include "symtab.h"
#include "inferior.h"
#include "signals.h"
#include "target.h"
#include "breakpoint.h"
#include "gdbtypes.h"
#include "expression.h"
#include "language.h"
#include "terminal.h" /* For job_control.  */

#include "getopt.h"

/* readline include files */
#include "readline.h"
#include "history.h"

/* readline defines this.  */
#undef savestring

#ifdef USG
#include <sys/types.h>
#include <unistd.h>
#endif

#include <string.h>
#ifndef	NO_SYS_FILE
#include <sys/file.h>
#endif
#include <setjmp.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <ctype.h>

#ifdef SET_STACK_LIMIT_HUGE
#include <sys/time.h>
#include <sys/resource.h>

int original_stack_limit;
#endif

/* Prototypes for local functions */

static char *
symbol_completion_function PARAMS ((char *, int));

static void
command_loop PARAMS ((void));

static void
command_loop_marker PARAMS ((int));

static void
print_gdb_version PARAMS ((FILE *));

static void
quit_command PARAMS ((char *, int));

static void
init_main PARAMS ((void));

static void
init_history PARAMS ((void));

static void
init_cmd_lists PARAMS ((void));

static void
float_handler PARAMS ((int));

static void
source_command PARAMS ((char *, int));

static void cd_command PARAMS ((char *, int));

static void
print_gnu_advertisement PARAMS ((void));

static void
init_signals PARAMS ((void));

static void
read_command_file PARAMS ((FILE *));

static void 
set_verbose PARAMS ((char *, int, struct cmd_list_element *));

static void
show_history PARAMS ((char *, int));

static void
set_history PARAMS ((char *, int));

static void
set_history_size_command PARAMS ((char *, int, struct cmd_list_element *));

static void
show_commands PARAMS ((char *, int));

static void
echo_command PARAMS ((char *, int));

static void
pwd_command PARAMS ((char *, int));

static void
show_version PARAMS ((char *, int));

static void
document_command PARAMS ((char *, int));

static void
define_command PARAMS ((char *, int));

static void
validate_comname PARAMS ((char *));

static void
help_command PARAMS ((char *, int));

static void
show_command PARAMS ((char *, int));

static void
info_command PARAMS ((char *, int));

static void
do_nothing PARAMS ((int));

static int
quit_cover PARAMS ((char *));

static void
disconnect PARAMS ((int));

static void
source_cleanup PARAMS ((FILE *));

/* If this definition isn't overridden by the header files, assume
   that isatty and fileno exist on this system.  */
#ifndef ISATTY
#define ISATTY(FP)	(isatty (fileno (FP)))
#endif

/* Initialization file name for gdb.  This is overridden in some configs.  */

#ifndef	GDBINIT_FILENAME
#define	GDBINIT_FILENAME	".gdbinit"
#endif
static char gdbinit[] = GDBINIT_FILENAME;
static int inhibit_gdbinit = 0;

#define	ALL_CLEANUPS	((struct cleanup *)0)

/* Version number of GDB, as a string.  */

extern char *version;

/* Canonical host name as a string. */

extern char *host_canonical;

/* Canonical target name as a string. */

extern char *target_canonical;

/* Message to be printed before the error message, when an error occurs.  */

extern char *error_pre_print;

/* Message to be printed before the warning message, when a warning occurs.  */

extern char *warning_pre_print;

extern char lang_frame_mismatch_warn[];		/* language.c */

/* Flag for whether we want all the "from_tty" gubbish printed.  */

int caution = 1;			/* Default is yes, sigh. */

/*
 * Define all cmd_list_element's
 */

/* Chain containing all defined commands.  */

struct cmd_list_element *cmdlist;

/* Chain containing all defined info subcommands.  */

struct cmd_list_element *infolist;

/* Chain containing all defined enable subcommands. */

struct cmd_list_element *enablelist;

/* Chain containing all defined disable subcommands. */

struct cmd_list_element *disablelist;

/* Chain containing all defined delete subcommands. */

struct cmd_list_element *deletelist;

/* Chain containing all defined "enable breakpoint" subcommands. */

struct cmd_list_element *enablebreaklist;

/* Chain containing all defined set subcommands */

struct cmd_list_element *setlist;

/* Chain containing all defined unset subcommands */

struct cmd_list_element *unsetlist;

/* Chain containing all defined show subcommands.  */

struct cmd_list_element *showlist;

/* Chain containing all defined \"set history\".  */

struct cmd_list_element *sethistlist;

/* Chain containing all defined \"show history\".  */

struct cmd_list_element *showhistlist;

/* Chain containing all defined \"unset history\".  */

struct cmd_list_element *unsethistlist;

/* Chain containing all defined maintenance subcommands. */

#if MAINTENANCE_CMDS
struct cmd_list_element *maintenancelist;
#endif

/* Chain containing all defined "maintenance info" subcommands. */

#if MAINTENANCE_CMDS
struct cmd_list_element *maintenanceinfolist;
#endif

/* Chain containing all defined "maintenance print" subcommands. */

#if MAINTENANCE_CMDS
struct cmd_list_element *maintenanceprintlist;
#endif

struct cmd_list_element *setprintlist;

struct cmd_list_element *showprintlist;

struct cmd_list_element *setchecklist;

struct cmd_list_element *showchecklist;

/* stdio stream that command input is being read from.  Set to stdin normally.
   Set by source_command to the file we are sourcing.  Set to NULL if we are
   executing a user-defined command.  */

FILE *instream;

/* Current working directory.  */

char *current_directory;

/* The directory name is actually stored here (usually).  */
static char dirbuf[1024];

/* Function to call before reading a command, if nonzero.
   The function receives two args: an input stream,
   and a prompt string.  */

void (*window_hook) PARAMS ((FILE *, char *));

extern int mapped_symbol_files;
extern int readnow_symbol_files;

int epoch_interface;
int xgdb_verbose;

/* gdb prints this when reading a command interactively */
static char *prompt;

/* Buffer used for reading command lines, and the size
   allocated for it so far.  */

char *line;
int linesize = 100;

/* Baud rate specified for talking to serial target systems.  Default
   is left as -1, so targets can choose their own defaults.  */

int baud_rate = -1;

/* Non-zero tells remote* modules to output debugging info.  */

int remote_debug = 0;

/* Signal to catch ^Z typed while reading a command: SIGTSTP or SIGCONT.  */

#ifndef STOP_SIGNAL
#ifdef SIGTSTP
#define STOP_SIGNAL SIGTSTP
static void stop_sig PARAMS ((int));
#endif
#endif

/* Some System V have job control but not sigsetmask(). */
#if !defined (HAVE_SIGSETMASK)
#define HAVE_SIGSETMASK !defined (USG)
#endif

#if 0 == (HAVE_SIGSETMASK)
#define sigsetmask(n)
#endif

/* Where to go for return_to_top_level (RETURN_ERROR).  */
static jmp_buf error_return;
/* Where to go for return_to_top_level (RETURN_QUIT).  */
static jmp_buf quit_return;

/* Temporary variable for SET_TOP_LEVEL.  */
static int top_level_val;

/* Do a setjmp on error_return and quit_return.  catch_errors is
   generally a cleaner way to do this, but main() would look pretty
   ugly if it had to use catch_errors each time.  */

#define SET_TOP_LEVEL() \
  (((top_level_val = setjmp (error_return)) \
    ? (PTR) 0 : (PTR) memcpy (quit_return, error_return, sizeof (jmp_buf))) \
   , top_level_val)

/* Return for reason REASON.  This generally gets back to the command
   loop, but can be caught via catch_errors.  */

NORETURN void
return_to_top_level (reason)
     enum return_reason reason;
{
  quit_flag = 0;
  immediate_quit = 0;

  /* Perhaps it would be cleaner to do this via the cleanup chain (not sure
     I can think of a reason why that is vital, though).  */
  bpstat_clear_actions(stop_bpstat);	/* Clear queued breakpoint commands */

  disable_current_display ();
  do_cleanups (ALL_CLEANUPS);
  (NORETURN void) longjmp
    (reason == RETURN_ERROR ? error_return : quit_return, 1);
}

/* Call FUNC with arg ARGS, catching any errors.  If there is no
   error, return the value returned by FUNC.  If there is an error,
   print ERRSTRING, print the specific error message, then return
   zero.

   Must not be called with immediate_quit in effect (bad things might
   happen, say we got a signal in the middle of a memcpy to quit_return).
   This is an OK restriction; with very few exceptions immediate_quit can
   be replaced by judicious use of QUIT.

   MASK specifies what to catch; it is normally set to
   RETURN_MASK_ALL, if for no other reason than that the code which
   calls catch_errors might not be set up to deal with a quit which
   isn't caught.  But if the code can deal with it, it generally
   should be RETURN_MASK_ERROR, unless for some reason it is more
   useful to abort only the portion of the operation inside the
   catch_errors.  Note that quit should return to the command line
   fairly quickly, even if some further processing is being done.  */

int
catch_errors (func, args, errstring, mask)
     int (*func) PARAMS ((char *));
     PTR args;
     char *errstring;
     return_mask mask;
{
  jmp_buf saved_error;
  jmp_buf saved_quit;
  jmp_buf tmp_jmp;
  int val;
  struct cleanup *saved_cleanup_chain;
  char *saved_error_pre_print;

  saved_cleanup_chain = save_cleanups ();
  saved_error_pre_print = error_pre_print;

  if (mask & RETURN_MASK_ERROR)
    memcpy ((char *)saved_error, (char *)error_return, sizeof (jmp_buf));
  if (mask & RETURN_MASK_QUIT)
    memcpy (saved_quit, quit_return, sizeof (jmp_buf));
  error_pre_print = errstring;

  if (setjmp (tmp_jmp) == 0)
    {
      if (mask & RETURN_MASK_ERROR)
	memcpy (error_return, tmp_jmp, sizeof (jmp_buf));
      if (mask & RETURN_MASK_QUIT)
	memcpy (quit_return, tmp_jmp, sizeof (jmp_buf));
      val = (*func) (args);
    }
  else
    val = 0;

  restore_cleanups (saved_cleanup_chain);

  error_pre_print = saved_error_pre_print;
  if (mask & RETURN_MASK_ERROR)
    memcpy (error_return, saved_error, sizeof (jmp_buf));
  if (mask & RETURN_MASK_QUIT)
    memcpy (quit_return, saved_quit, sizeof (jmp_buf));
  return val;
}

/* Handler for SIGHUP.  */

static void
disconnect (signo)
int signo;
{
  catch_errors (quit_cover, NULL,
		"Could not kill the program being debugged", RETURN_MASK_ALL);
  signal (SIGHUP, SIG_DFL);
  kill (getpid (), SIGHUP);
}

/* Just a little helper function for disconnect().  */

static int
quit_cover (s)
char *s;
{
  caution = 0;		/* Throw caution to the wind -- we're exiting.
			   This prevents asking the user dumb questions.  */
  quit_command((char *)0, 0);
  return 0;
}

/* Clean up on error during a "source" command (or execution of a
   user-defined command).  */

static void
source_cleanup (stream)
     FILE *stream;
{
  /* Restore the previous input stream.  */
  instream = stream;
}

/* Read commands from STREAM.  */
static void
read_command_file (stream)
     FILE *stream;
{
  struct cleanup *cleanups;

  cleanups = make_cleanup (source_cleanup, instream);
  instream = stream;
  command_loop ();
  do_cleanups (cleanups);
}

int
main (argc, argv)
     int argc;
     char **argv;
{
  int count;
  static int quiet = 0;
  static int batch = 0;

  /* Pointers to various arguments from command line.  */
  char *symarg = NULL;
  char *execarg = NULL;
  char *corearg = NULL;
  char *cdarg = NULL;
  char *ttyarg = NULL;

  /* These are static so that we can take their address in an initializer.  */
  static int print_help;
  static int print_version;

  /* Pointers to all arguments of --command option.  */
  char **cmdarg;
  /* Allocated size of cmdarg.  */
  int cmdsize;
  /* Number of elements of cmdarg used.  */
  int ncmd;

  /* Indices of all arguments of --directory option.  */
  char **dirarg;
  /* Allocated size.  */
  int dirsize;
  /* Number of elements used.  */
  int ndir;
  
  struct stat homebuf, cwdbuf;
  char *homedir, *homeinit;

  register int i;

  /* This needs to happen before the first use of malloc.  */
  init_malloc ((PTR) NULL);

#if defined (ALIGN_STACK_ON_STARTUP)
  i = (int) &count & 0x3;
  if (i != 0)
    alloca (4 - i);
#endif

  /* If error() is called from initialization code, just exit */
  if (SET_TOP_LEVEL ()) {
    exit(1);
  }

  cmdsize = 1;
  cmdarg = (char **) xmalloc (cmdsize * sizeof (*cmdarg));
  ncmd = 0;
  dirsize = 1;
  dirarg = (char **) xmalloc (dirsize * sizeof (*dirarg));
  ndir = 0;

  quit_flag = 0;
  line = (char *) xmalloc (linesize);
  line[0] = '\0';		/* Terminate saved (now empty) cmd line */
  instream = stdin;

  getcwd (dirbuf, sizeof (dirbuf));
  current_directory = dirbuf;

#ifdef SET_STACK_LIMIT_HUGE
  {
    struct rlimit rlim;

    /* Set the stack limit huge so that alloca (particularly stringtab
     * in dbxread.c) does not fail. */
    getrlimit (RLIMIT_STACK, &rlim);
    original_stack_limit = rlim.rlim_cur;
    rlim.rlim_cur = rlim.rlim_max;
    setrlimit (RLIMIT_STACK, &rlim);
  }
#endif /* SET_STACK_LIMIT_HUGE */

  /* Parse arguments and options.  */
  {
    int c;
    /* When var field is 0, use flag field to record the equivalent
       short option (or arbitrary numbers starting at 10 for those
       with no equivalent).  */
    static struct option long_options[] =
      {
	{"readnow", no_argument, &readnow_symbol_files, 1},
	{"r", no_argument, &readnow_symbol_files, 1},
	{"mapped", no_argument, &mapped_symbol_files, 1},
	{"m", no_argument, &mapped_symbol_files, 1},
	{"quiet", no_argument, &quiet, 1},
	{"q", no_argument, &quiet, 1},
	{"silent", no_argument, &quiet, 1},
	{"nx", no_argument, &inhibit_gdbinit, 1},
	{"n", no_argument, &inhibit_gdbinit, 1},
	{"batch", no_argument, &batch, 1},
	{"epoch", no_argument, &epoch_interface, 1},
	{"fullname", no_argument, &frame_file_full_name, 1},
	{"f", no_argument, &frame_file_full_name, 1},
	{"help", no_argument, &print_help, 1},
	{"se", required_argument, 0, 10},
	{"symbols", required_argument, 0, 's'},
	{"s", required_argument, 0, 's'},
	{"exec", required_argument, 0, 'e'},
	{"e", required_argument, 0, 'e'},
	{"core", required_argument, 0, 'c'},
	{"c", required_argument, 0, 'c'},
	{"command", required_argument, 0, 'x'},
	{"version", no_argument, &print_version, 1},
	{"x", required_argument, 0, 'x'},
	{"directory", required_argument, 0, 'd'},
	{"cd", required_argument, 0, 11},
	{"tty", required_argument, 0, 't'},
	{"baud", required_argument, 0, 'b'},
	{"b", required_argument, 0, 'b'},
/* Allow machine descriptions to add more options... */
#ifdef ADDITIONAL_OPTIONS
	ADDITIONAL_OPTIONS
#endif
	{0, no_argument, 0, 0},
      };

    while (1)
      {
	int option_index;

	c = getopt_long_only (argc, argv, "",
			      long_options, &option_index);
	if (c == EOF)
	  break;

	/* Long option that takes an argument.  */
	if (c == 0 && long_options[option_index].flag == 0)
	  c = long_options[option_index].val;

	switch (c)
	  {
	  case 0:
	    /* Long option that just sets a flag.  */
	    break;
	  case 10:
	    symarg = optarg;
	    execarg = optarg;
	    break;
	  case 11:
	    cdarg = optarg;
	    break;
	  case 's':
	    symarg = optarg;
	    break;
	  case 'e':
	    execarg = optarg;
	    break;
	  case 'c':
	    corearg = optarg;
	    break;
	  case 'x':
	    cmdarg[ncmd++] = optarg;
	    if (ncmd >= cmdsize)
	      {
		cmdsize *= 2;
		cmdarg = (char **) xrealloc ((char *)cmdarg,
					     cmdsize * sizeof (*cmdarg));
	      }
	    break;
	  case 'd':
	    dirarg[ndir++] = optarg;
	    if (ndir >= dirsize)
	      {
		dirsize *= 2;
		dirarg = (char **) xrealloc ((char *)dirarg,
					     dirsize * sizeof (*dirarg));
	      }
	    break;
	  case 't':
	    ttyarg = optarg;
	    break;
	  case 'q':
	    quiet = 1;
	    break;
	  case 'b':
	    {
	      int i;
	      char *p;

	      i = strtol (optarg, &p, 0);
	      if (i == 0 && p == optarg)
		warning ("Could not set baud rate to `%s'.\n", optarg);
	      else
		baud_rate = i;
	    }
	    break;

#ifdef ADDITIONAL_OPTION_CASES
	  ADDITIONAL_OPTION_CASES
#endif
	  case '?':
	    fprintf (stderr,
		     "Use `%s --help' for a complete list of options.\n",
		     argv[0]);
	    exit (1);
	  }
      }

    /* OK, that's all the options.  The other arguments are filenames.  */
    count = 0;
    for (; optind < argc; optind++)
      switch (++count)
	{
	case 1:
	  symarg = argv[optind];
	  execarg = argv[optind];
	  break;
	case 2:
	  corearg = argv[optind];
	  break;
	case 3:
	  fprintf (stderr,
		   "Excess command line arguments ignored. (%s%s)\n",
		   argv[optind], (optind == argc - 1) ? "" : " ...");
	  break;
	}
    if (batch)
      quiet = 1;
  }

  /* Run the init function of each source file */

  init_cmd_lists ();	/* This needs to be done first */
  initialize_all_files ();
  init_main ();		/* But that omits this file!  Do it now */
  init_signals ();

  /* Do these (and anything which might call wrap_here or *_filtered)
     after initialize_all_files.  */
  if (print_version)
    {
      print_gdb_version (stdout);
      wrap_here ("");
      printf_filtered ("\n");
      exit (0);
    }

  if (print_help)
    {
      /* --version is intentionally not documented here, because we
	 are printing the version here, and the help is long enough
	 already.  */

      print_gdb_version (stdout);
      /* Make sure the output gets printed.  */
      wrap_here ("");
      printf_filtered ("\n");

      /* But don't use *_filtered here.  We don't want to prompt for continue
	 no matter how small the screen or how much we're going to print.  */
      fputs ("\
This is the GNU debugger.  Usage:\n\
    gdb [options] [executable-file [core-file or process-id]]\n\
Options:\n\
  --help             Print this message.\n\
  --quiet            Do not print version number on startup.\n\
  --fullname         Output information used by emacs-GDB interface.\n\
  --epoch            Output information used by epoch emacs-GDB interface.\n\
  --batch            Exit after processing options.\n\
  --nx               Do not read .gdbinit file.\n\
  --tty=TTY          Use TTY for input/output by the program being debugged.\n\
  --cd=DIR           Change current directory to DIR.\n\
  --directory=DIR    Search for source files in DIR.\n\
  --command=FILE     Execute GDB commands from FILE.\n\
  --symbols=SYMFILE  Read symbols from SYMFILE.\n\
  --exec=EXECFILE    Use EXECFILE as the executable.\n\
  --se=FILE          Use FILE as symbol file and executable file.\n\
  --core=COREFILE    Analyze the core dump COREFILE.\n\
  -b BAUDRATE        Set serial port baud rate used for remote debugging.\n\
  --mapped           Use mapped symbol files if supported on this system.\n\
  --readnow          Fully read symbol files on first access.\n\
", stdout);
#ifdef ADDITIONAL_OPTION_HELP
      fputs (ADDITIONAL_OPTION_HELP, stdout);
#endif
      fputs ("\n\
For more information, type \"help\" from within GDB, or consult the\n\
GDB manual (available as on-line info or a printed manual).\n", stdout);
      exit (0);
    }
    
  if (!quiet)
    {
      /* Print all the junk at the top, with trailing "..." if we are about
	 to read a symbol file (possibly slowly).  */
      print_gnu_advertisement ();
      print_gdb_version (stdout);
      if (symarg)
	printf_filtered ("..");
      wrap_here("");
      fflush (stdout);		/* Force to screen during slow operations */
    }

  error_pre_print = "\n\n";
  /* We may get more than one warning, don't double space all of them... */
  warning_pre_print = "\nwarning: ";

  /* We need a default language for parsing expressions, so simple things like
     "set width 0" won't fail if no language is explicitly set in a config file
     or implicitly set by reading an executable during startup. */
  set_language (language_c);
  expected_language = current_language;	/* don't warn about the change.  */

  /* Read and execute $HOME/.gdbinit file, if it exists.  This is done
     *before* all the command line arguments are processed; it sets
     global parameters, which are independent of what file you are
     debugging or what directory you are in.  */
  homedir = getenv ("HOME");
  if (homedir)
    {
      homeinit = (char *) alloca (strlen (getenv ("HOME")) +
				  strlen (gdbinit) + 10);
      strcpy (homeinit, getenv ("HOME"));
      strcat (homeinit, "/");
      strcat (homeinit, gdbinit);
      if (!inhibit_gdbinit && access (homeinit, R_OK) == 0)
	{
	  if (!SET_TOP_LEVEL ())
	    source_command (homeinit, 0);
	}
      do_cleanups (ALL_CLEANUPS);

      /* Do stats; no need to do them elsewhere since we'll only
	 need them if homedir is set.  Make sure that they are
	 zero in case one of them fails (this guarantees that they
	 won't match if either exists).  */
      
      memset (&homebuf, 0, sizeof (struct stat));
      memset (&cwdbuf, 0, sizeof (struct stat));
      
      stat (homeinit, &homebuf);
      stat (gdbinit, &cwdbuf); /* We'll only need this if
				       homedir was set.  */
    }
  
  /* Now perform all the actions indicated by the arguments.  */
  if (cdarg != NULL)
    {
      if (!SET_TOP_LEVEL ())
	{
	  cd_command (cdarg, 0);
	  init_source_path ();
	}
    }
  do_cleanups (ALL_CLEANUPS);

  for (i = 0; i < ndir; i++)
    if (!SET_TOP_LEVEL ())
      directory_command (dirarg[i], 0);
  free ((PTR)dirarg);
  do_cleanups (ALL_CLEANUPS);

  if (execarg != NULL
      && symarg != NULL
      && STREQ (execarg, symarg))
    {
      /* The exec file and the symbol-file are the same.  If we can't open
	 it, better only print one error message.  */
      if (!SET_TOP_LEVEL ())
	{
	  exec_file_command (execarg, !batch);
	  symbol_file_command (symarg, 0);
	}
    }
  else
    {
      if (execarg != NULL)
	if (!SET_TOP_LEVEL ())
	  exec_file_command (execarg, !batch);
      if (symarg != NULL)
	if (!SET_TOP_LEVEL ())
	  symbol_file_command (symarg, 0);
    }
  do_cleanups (ALL_CLEANUPS);

  /* After the symbol file has been read, print a newline to get us
     beyond the copyright line...  But errors should still set off
     the error message with a (single) blank line.  */
  if (!quiet)
    printf_filtered ("\n");
  error_pre_print = "\n";
  warning_pre_print = "\nwarning: ";

  if (corearg != NULL)
    if (!SET_TOP_LEVEL ())
      core_file_command (corearg, !batch);
    else if (isdigit (corearg[0]) && !SET_TOP_LEVEL ())
      attach_command (corearg, !batch);
  do_cleanups (ALL_CLEANUPS);

  if (ttyarg != NULL)
    if (!SET_TOP_LEVEL ())
      tty_command (ttyarg, !batch);
  do_cleanups (ALL_CLEANUPS);

#ifdef ADDITIONAL_OPTION_HANDLER
  ADDITIONAL_OPTION_HANDLER;
#endif

  /* Error messages should no longer be distinguished with extra output. */
  error_pre_print = 0;
  warning_pre_print = "warning: ";

  /* Read the .gdbinit file in the current directory, *if* it isn't
     the same as the $HOME/.gdbinit file (it should exist, also).  */
  
  if (!homedir
      || memcmp ((char *) &homebuf, (char *) &cwdbuf, sizeof (struct stat)))
    if (!inhibit_gdbinit && access (gdbinit, R_OK) == 0)
      {
	if (!SET_TOP_LEVEL ())
	  source_command (gdbinit, 0);
      }
  do_cleanups (ALL_CLEANUPS);

  for (i = 0; i < ncmd; i++)
    {
      if (!SET_TOP_LEVEL ())
	{
	  if (cmdarg[i][0] == '-' && cmdarg[i][1] == '\0')
	    read_command_file (stdin);
	  else
	    source_command (cmdarg[i], !batch);
	  do_cleanups (ALL_CLEANUPS);
	}
    }
  free ((PTR)cmdarg);

  /* Read in the old history after all the command files have been read. */
  init_history();

  if (batch)
    {
      /* We have hit the end of the batch file.  */
      exit (0);
    }

  /* Do any host- or target-specific hacks.  This is used for i960 targets
     to force the user to set a nindy target and spec its parameters.  */

#ifdef BEFORE_MAIN_LOOP_HOOK
  BEFORE_MAIN_LOOP_HOOK;
#endif

  /* The command loop.  */

  while (1)
    {
      if (!SET_TOP_LEVEL ())
	{
	  do_cleanups (ALL_CLEANUPS);		/* Do complete cleanup */
	  command_loop ();
          quit_command ((char *)0, instream == stdin);
	}
    }
  /* No exit -- exit is through quit_command.  */
}

void
execute_user_command (c, args)
     struct cmd_list_element *c;
     char *args;
{
  register struct command_line *cmdlines;
  struct cleanup *old_chain;
  
  if (args)
    error ("User-defined commands cannot take arguments.");

  cmdlines = c->user_commands;
  if (cmdlines == 0)
    /* Null command */
    return;

  /* Set the instream to 0, indicating execution of a
     user-defined function.  */
  old_chain = make_cleanup (source_cleanup, instream);
  instream = (FILE *) 0;
  while (cmdlines)
    {
      execute_command (cmdlines->line, 0);
      cmdlines = cmdlines->next;
    }
  do_cleanups (old_chain);
}

/* Execute the line P as a command.
   Pass FROM_TTY as second argument to the defining function.  */

void
execute_command (p, from_tty)
     char *p;
     int from_tty;
{
  register struct cmd_list_element *c;
  register enum language flang;
  static int warned = 0;

  free_all_values ();

  /* This can happen when command_line_input hits end of file.  */
  if (p == NULL)
      return;
  
  while (*p == ' ' || *p == '\t') p++;
  if (*p)
    {
      char *arg;
      
      c = lookup_cmd (&p, cmdlist, "", 0, 1);
      /* Pass null arg rather than an empty one.  */
      arg = *p ? p : 0;

      /* If this command has been hooked, run the hook first. */
      if (c->hook)
	execute_user_command (c->hook, (char *)0);

      if (c->class == class_user)
	execute_user_command (c, arg);
      else if (c->type == set_cmd || c->type == show_cmd)
	do_setshow_command (arg, from_tty & caution, c);
      else if (c->function.cfunc == NO_FUNCTION)
	error ("That is not a command, just a help topic.");
      else
	(*c->function.cfunc) (arg, from_tty & caution);
   }

  /* Tell the user if the language has changed (except first time).  */
  if (current_language != expected_language)
  {
    if (language_mode == language_mode_auto) {
      language_info (1);	/* Print what changed.  */
    }
    warned = 0;
  }

  /* Warn the user if the working language does not match the
     language of the current frame.  Only warn the user if we are
     actually running the program, i.e. there is a stack. */
  /* FIXME:  This should be cacheing the frame and only running when
     the frame changes.  */
  if (target_has_stack)
  {
    flang = get_frame_language ();
    if (!warned
        && flang != language_unknown
	&& flang != current_language->la_language)
    {
      printf_filtered ("%s\n", lang_frame_mismatch_warn);
      warned = 1;
    }
  }
}

/* ARGSUSED */
static void
command_loop_marker (foo)
     int foo;
{
}

/* Read commands from `instream' and execute them
   until end of file or error reading instream.  */
static void
command_loop ()
{
  struct cleanup *old_chain;
  char *command;
  int stdin_is_tty = ISATTY (stdin);

  while (!feof (instream))
    {
      if (window_hook && instream == stdin)
	(*window_hook) (instream, prompt);

      quit_flag = 0;
      if (instream == stdin && stdin_is_tty)
	reinitialize_more_filter ();
      old_chain = make_cleanup (command_loop_marker, 0);
      command = command_line_input (instream == stdin ? prompt : (char *) NULL,
				      instream == stdin);
      if (command == 0)
	return;
      execute_command (command, instream == stdin);
      /* Do any commands attached to breakpoint we stopped at.  */
      bpstat_do_actions (&stop_bpstat);
      do_cleanups (old_chain);
    }
}

/* Commands call this if they do not want to be repeated by null lines.  */

void
dont_repeat ()
{
  /* If we aren't reading from standard input, we are saving the last
     thing read from stdin in line and don't want to delete it.  Null lines
     won't repeat here in any case.  */
  if (instream == stdin)
    *line = 0;
}

/* Read a line from the stream "instream" without command line editing.

   It prints PRROMPT once at the start.
   Action is compatible with "readline", e.g. space for the result is 
   malloc'd and should be freed by the caller.

   A NULL return means end of file.  */
char *
gdb_readline (prrompt)
     char *prrompt;
{
  int c;
  char *result;
  int input_index = 0;
  int result_size = 80;

  if (prrompt)
    {
      /* Don't use a _filtered function here.  It causes the assumed
	 character position to be off, since the newline we read from
	 the user is not accounted for.  */
      fputs (prrompt, stdout);
      fflush (stdout);
    }
  
  result = (char *) xmalloc (result_size);

  while (1)
    {
      /* Read from stdin if we are executing a user defined command.
	 This is the right thing for prompt_for_continue, at least.  */
      c = fgetc (instream ? instream : stdin);

      if (c == EOF)
	{
	  if (input_index > 0)
	    /* The last line does not end with a newline.  Return it, and
	       if we are called again fgetc will still return EOF and
	       we'll return NULL then.  */
	    break;
	  free (result);
	  return NULL;
	}

      if (c == '\n')
	break;

      result[input_index++] = c;
      while (input_index >= result_size)
	{
	  result_size *= 2;
	  result = (char *) xrealloc (result, result_size);
	}
    }

  result[input_index++] = '\0';
  return result;
}

/* Variables which control command line editing and history
   substitution.  These variables are given default values at the end
   of this file.  */
static int command_editing_p;
static int history_expansion_p;
static int write_history_p;
static int history_size;
static char *history_filename;

/* readline uses the word breaks for two things:
   (1) In figuring out where to point the TEXT parameter to the
   rl_completion_entry_function.  Since we don't use TEXT for much,
   it doesn't matter a lot what the word breaks are for this purpose, but
   it does affect how much stuff M-? lists.
   (2) If one of the matches contains a word break character, readline
   will quote it.  That's why we switch between
   gdb_completer_word_break_characters and
   gdb_completer_command_word_break_characters.  I'm not sure when
   we need this behavior (perhaps for funky characters in C++ symbols?).  */

/* Variables which are necessary for fancy command line editing.  */
char *gdb_completer_word_break_characters =
  " \t\n!@#$%^&*()+=|~`}{[]\"';:?/>.<,-";

/* When completing on command names, we remove '-' from the list of
   word break characters, since we use it in command names.  If the
   readline library sees one in any of the current completion strings,
   it thinks that the string needs to be quoted and automatically supplies
   a leading quote. */
char *gdb_completer_command_word_break_characters =
  " \t\n!@#$%^&*()+=|~`}{[]\"';:?/>.<,";

/* Characters that can be used to quote completion strings.  Note that we
   can't include '"' because the gdb C parser treats such quoted sequences
   as strings. */
char *gdb_completer_quote_characters =
  "'";

/* Functions that are used as part of the fancy command line editing.  */

/* This can be used for functions which don't want to complete on symbols
   but don't want to complete on anything else either.  */
/* ARGSUSED */
char **
noop_completer (text, prefix)
     char *text;
     char *prefix;
{
  return NULL;
}

/* Complete on filenames.  */
char **
filename_completer (text, word)
     char *text;
     char *word;
{
  /* From readline.  */
  extern char *filename_completion_function ();
  int subsequent_name;
  char **return_val;
  int return_val_used;
  int return_val_alloced;

  return_val_used = 0;
  /* Small for testing.  */
  return_val_alloced = 1;
  return_val = (char **) xmalloc (return_val_alloced * sizeof (char *));

  subsequent_name = 0;
  while (1)
    {
      char *p;
      p = filename_completion_function (text, subsequent_name);
      if (return_val_used >= return_val_alloced)
	{
	  return_val_alloced *= 2;
	  return_val =
	    (char **) xrealloc (return_val,
				return_val_alloced * sizeof (char *));
	}
      if (p == NULL)
	{
	  return_val[return_val_used++] = p;
	  break;
	}
      /* Like emacs, don't complete on old versions.  Especially useful
	 in the "source" command.  */
      if (p[strlen (p) - 1] == '~')
	continue;

      {
	char *q;
	if (word == text)
	  /* Return exactly p.  */
	  return_val[return_val_used++] = p;
	else if (word > text)
	  {
	    /* Return some portion of p.  */
	    q = xmalloc (strlen (p) + 5);
	    strcpy (q, p + (word - text));
	    return_val[return_val_used++] = q;
	    free (p);
	  }
	else
	  {
	    /* Return some of TEXT plus p.  */
	    q = xmalloc (strlen (p) + (text - word) + 5);
	    strncpy (q, word, text - word);
	    q[text - word] = '\0';
	    strcat (q, p);
	    return_val[return_val_used++] = q;
	    free (p);
	  }
      }
      subsequent_name = 1;
    }
#if 0
  /* There is no way to do this just long enough to affect quote inserting
     without also affecting the next completion.  This should be fixed in
     readline.  FIXME.  */
  /* Insure that readline does the right thing
     with respect to inserting quotes.  */
  rl_completer_word_break_characters = "";
#endif
  return return_val;
}

/* Here are some useful test cases for completion.  FIXME: These should
   be put in the test suite.  They should be tested with both M-? and TAB.

   "show output-" "radix"
   "show output" "-radix"
   "p" ambiguous (commands starting with p--path, print, printf, etc.)
   "p "  ambiguous (all symbols)
   "info t foo" no completions
   "info t " no completions
   "info t" ambiguous ("info target", "info terminal", etc.)
   "info ajksdlfk" no completions
   "info ajksdlfk " no completions
   "info" " "
   "info " ambiguous (all info commands)
   "p \"a" no completions (string constant)
   "p 'a" ambiguous (all symbols starting with a)
   "p b-a" ambiguous (all symbols starting with a)
   "p b-" ambiguous (all symbols)
   "file Make" "file" (word break hard to screw up here)
   "file ../gdb.stabs/wi" "erd" (needs to not break word at slash)
   */

/* Generate completions one by one for the completer.  Each time we are
   called return another potential completion to the caller.  The function
   is misnamed; it just completes on commands or passes the buck to the
   command's completer function; the stuff specific to symbol completion
   is in make_symbol_completion_list.

   TEXT is readline's idea of the "word" we are looking at; we don't really
   like readline's ideas about word breaking so we ignore it.

   MATCHES is the number of matches that have currently been collected from
   calling this completion function.  When zero, then we need to initialize,
   otherwise the initialization has already taken place and we can just
   return the next potential completion string.

   Returns NULL if there are no more completions, else a pointer to a string
   which is a possible completion.

   RL_LINE_BUFFER is available to be looked at; it contains the entire text
   of the line.  RL_POINT is the offset in that line of the cursor.  You
   should pretend that the line ends at RL_POINT. */

static char *
symbol_completion_function (text, matches)
     char *text;
     int matches;
{
  static char **list = (char **)NULL;		/* Cache of completions */
  static int index;				/* Next cached completion */
  char *output = NULL;
  char *tmp_command, *p;
  /* Pointer within tmp_command which corresponds to text.  */
  char *word;
  struct cmd_list_element *c, *result_list;
  extern char *rl_line_buffer;
  extern int rl_point;

  if (matches == 0)
    {
      /* The caller is beginning to accumulate a new set of completions, so
	 we need to find all of them now, and cache them for returning one at
	 a time on future calls. */

      if (list)
	{
	  /* Free the storage used by LIST, but not by the strings inside.
	     This is because rl_complete_internal () frees the strings. */
	  free ((PTR)list);
	}
      list = 0;
      index = 0;

      /* Choose the default set of word break characters to break completions.
	 If we later find out that we are doing completions on command strings
	 (as opposed to strings supplied by the individual command completer
	 functions, which can be any string) then we will switch to the
	 special word break set for command strings, which leaves out the
	 '-' character used in some commands.  */

      rl_completer_word_break_characters =
	  gdb_completer_word_break_characters;

      /* Decide whether to complete on a list of gdb commands or on symbols. */
      tmp_command = (char *) alloca (rl_point + 1);
      p = tmp_command;

      strncpy (tmp_command, rl_line_buffer, rl_point);
      tmp_command[rl_point] = '\0';
      /* Since text always contains some number of characters leading up
	 to rl_point, we can find the equivalent position in tmp_command
	 by subtracting that many characters from the end of tmp_command.  */
      word = tmp_command + rl_point - strlen (text);

      if (rl_point == 0)
	{
	  /* An empty line we want to consider ambiguous; that is, it
	     could be any command.  */
	  c = (struct cmd_list_element *) -1;
	  result_list = 0;
	}
      else
	{
	  c = lookup_cmd_1 (&p, cmdlist, &result_list, 1);
	}

      /* Move p up to the next interesting thing.  */
      while (*p == ' ' || *p == '\t')
	{
	  p++;
	}

      if (!c)
	{
	  /* It is an unrecognized command.  So there are no
	     possible completions.  */
	  list = NULL;
	}
      else if (c == (struct cmd_list_element *) -1)
	{
	  char *q;

	  /* lookup_cmd_1 advances p up to the first ambiguous thing, but
	     doesn't advance over that thing itself.  Do so now.  */
	  q = p;
	  while (*q && (isalnum (*q) || *q == '-' || *q == '_'))
	    ++q;
	  if (q != tmp_command + rl_point)
	    {
	      /* There is something beyond the ambiguous
		 command, so there are no possible completions.  For
		 example, "info t " or "info t foo" does not complete
		 to anything, because "info t" can be "info target" or
		 "info terminal".  */
	      list = NULL;
	    }
	  else
	    {
	      /* We're trying to complete on the command which was ambiguous.
		 This we can deal with.  */
	      if (result_list)
		{
		  list = complete_on_cmdlist (*result_list->prefixlist, p,
					      word);
		}
	      else
		{
		  list = complete_on_cmdlist (cmdlist, p, word);
		}
	      /* Insure that readline does the right thing with respect to
		 inserting quotes.  */
	      rl_completer_word_break_characters =
		gdb_completer_command_word_break_characters;
	    }
	}
      else
	{
	  /* We've recognized a full command.  */

	  if (p == tmp_command + rl_point)
	    {
	      /* There is no non-whitespace in the line beyond the command.  */

	      if (p[-1] == ' ' || p[-1] == '\t')
		{
		  /* The command is followed by whitespace; we need to complete
		     on whatever comes after command.  */
		  if (c->prefixlist)
		    {
		      /* It is a prefix command; what comes after it is
			 a subcommand (e.g. "info ").  */
		      list = complete_on_cmdlist (*c->prefixlist, p, word);

		      /* Insure that readline does the right thing
			 with respect to inserting quotes.  */
		      rl_completer_word_break_characters =
			gdb_completer_command_word_break_characters;
		    }
		  else
		    {
		      /* It is a normal command; what comes after it is
			 completed by the command's completer function.  */
		      list = (*c->completer) (p, word);
		    }
		}
	      else
		{
		  /* The command is not followed by whitespace; we need to
		     complete on the command itself.  e.g. "p" which is a
		     command itself but also can complete to "print", "ptype"
		     etc.  */
		  char *q;

		  /* Find the command we are completing on.  */
		  q = p;
		  while (q > tmp_command)
		    {
		      if (isalnum (q[-1]) || q[-1] == '-' || q[-1] == '_')
			--q;
		      else
			break;
		    }

		  list = complete_on_cmdlist (result_list, q, word);

		  /* Insure that readline does the right thing
		     with respect to inserting quotes.  */
		  rl_completer_word_break_characters =
		    gdb_completer_command_word_break_characters;
		}
	    }
	  else
	    {
	      /* There is non-whitespace beyond the command.  */

	      if (c->prefixlist && !c->allow_unknown)
		{
		  /* It is an unrecognized subcommand of a prefix command,
		     e.g. "info adsfkdj".  */
		  list = NULL;
		}
	      else
		{
		  /* It is a normal command.  */
		  list = (*c->completer) (p, word);
		}
	    }
	}
    }

  /* If we found a list of potential completions during initialization then
     dole them out one at a time.  The vector of completions is NULL
     terminated, so after returning the last one, return NULL (and continue
     to do so) each time we are called after that, until a new list is
     available. */

  if (list)
    {
      output = list[index];
      if (output)
	{
	  index++;
	}
    }

#if 0
  /* Can't do this because readline hasn't yet checked the word breaks
     for figuring out whether to insert a quote.  */
  if (output == NULL)
    /* Make sure the word break characters are set back to normal for the
       next time that readline tries to complete something.  */
    rl_completer_word_break_characters =
      gdb_completer_word_break_characters;
#endif

  return (output);
}

/* Skip over a possibly quoted word (as defined by the quote characters
   and word break characters the completer uses).  Returns pointer to the
   location after the "word". */

char *
skip_quoted (str)
     char *str;
{
  char quote_char = '\0';
  char *scan;

  for (scan = str; *scan != '\0'; scan++)
    {
      if (quote_char != '\0')
	{
	  /* Ignore everything until the matching close quote char */
	  if (*scan == quote_char)
	    {
	      /* Found matching close quote. */
	      scan++;
	      break;
	    }
	}
      else if (strchr (gdb_completer_quote_characters, *scan))
	{
	  /* Found start of a quoted string. */
	  quote_char = *scan;
	}
      else if (strchr (gdb_completer_word_break_characters, *scan))
	{
	  break;
	}
    }
  return (scan);
}


#ifdef STOP_SIGNAL
static void
stop_sig (signo)
int signo;
{
#if STOP_SIGNAL == SIGTSTP
  signal (SIGTSTP, SIG_DFL);
  sigsetmask (0);
  kill (getpid (), SIGTSTP);
  signal (SIGTSTP, stop_sig);
#else
  signal (STOP_SIGNAL, stop_sig);
#endif
  printf ("%s", prompt);
  fflush (stdout);

  /* Forget about any previous command -- null line now will do nothing.  */
  dont_repeat ();
}
#endif /* STOP_SIGNAL */

/* Initialize signal handlers. */
static void
do_nothing (signo)
int signo;
{
}

static void
init_signals ()
{
  signal (SIGINT, request_quit);

  /* If we initialize SIGQUIT to SIG_IGN, then the SIG_IGN will get
     passed to the inferior, which we don't want.  It would be
     possible to do a "signal (SIGQUIT, SIG_DFL)" after we fork, but
     on BSD4.3 systems using vfork, that can affect the
     GDB process as well as the inferior (the signal handling tables
     might be in memory, shared between the two).  Since we establish
     a handler for SIGQUIT, when we call exec it will set the signal
     to SIG_DFL for us.  */
  signal (SIGQUIT, do_nothing);
  if (signal (SIGHUP, do_nothing) != SIG_IGN)
    signal (SIGHUP, disconnect);
  signal (SIGFPE, float_handler);

#if defined(SIGWINCH) && defined(SIGWINCH_HANDLER)
  signal (SIGWINCH, SIGWINCH_HANDLER);
#endif
}

/* Read one line from the command input stream `instream'
   into the local static buffer `linebuffer' (whose current length
   is `linelength').
   The buffer is made bigger as necessary.
   Returns the address of the start of the line.

   NULL is returned for end of file.

   *If* the instream == stdin & stdin is a terminal, the line read
   is copied into the file line saver (global var char *line,
   length linesize) so that it can be duplicated.

   This routine either uses fancy command line editing or
   simple input as the user has requested.  */

char *
command_line_input (prrompt, repeat)
     char *prrompt;
     int repeat;
{
  static char *linebuffer = 0;
  static unsigned linelength = 0;
  register char *p;
  char *p1;
  char *rl;
  char *local_prompt = prrompt;
  register int c;
  char *nline;
  char got_eof = 0;

  if (linebuffer == 0)
    {
      linelength = 80;
      linebuffer = (char *) xmalloc (linelength);
    }

  p = linebuffer;

  /* Control-C quits instantly if typed while in this loop
     since it should not wait until the user types a newline.  */
  immediate_quit++;
#ifdef STOP_SIGNAL
  if (job_control)
    signal (STOP_SIGNAL, stop_sig);
#endif

  while (1)
    {
      /* Reports are that some Sys V's don't flush stdout/err on reads
	 from stdin, when stdin/out are sockets rather than ttys.  So we
	 have to do it ourselves, to make emacs-gdb and xxgdb work.
	 On other machines, doing this once per input should be a cheap nop.  */
      fflush (stdout);
      fflush (stderr);

      /* Don't use fancy stuff if not talking to stdin.  */
      if (command_editing_p && instream == stdin
	  && ISATTY (instream))
	rl = readline (local_prompt);
      else
	rl = gdb_readline (local_prompt);

      if (!rl || rl == (char *) EOF)
	{
	  got_eof = 1;
	  break;
	}
      if (strlen(rl) + 1 + (p - linebuffer) > linelength)
	{
	  linelength = strlen(rl) + 1 + (p - linebuffer);
	  nline = (char *) xrealloc (linebuffer, linelength);
	  p += nline - linebuffer;
	  linebuffer = nline;
	}
      p1 = rl;
      /* Copy line.  Don't copy null at end.  (Leaves line alone
         if this was just a newline)  */
      while (*p1)
	*p++ = *p1++;

      free (rl);			/* Allocated in readline.  */

      if (p == linebuffer || *(p - 1) != '\\')
	break;

      p--;			/* Put on top of '\'.  */
      local_prompt = (char *) 0;
  }

#ifdef STOP_SIGNAL
  if (job_control)
    signal (STOP_SIGNAL, SIG_DFL);
#endif
  immediate_quit--;

  if (got_eof)
    return NULL;

  /* Do history expansion if that is wished.  */
  if (history_expansion_p && instream == stdin
      && ISATTY (instream))
    {
      char *history_value;
      int expanded;

      *p = '\0';		/* Insert null now.  */
      expanded = history_expand (linebuffer, &history_value);
      if (expanded)
	{
	  /* Print the changes.  */
	  printf ("%s\n", history_value);

	  /* If there was an error, call this function again.  */
	  if (expanded < 0)
	    {
	      free (history_value);
	      return command_line_input (prrompt, repeat);
	    }
	  if (strlen (history_value) > linelength)
	    {
	      linelength = strlen (history_value) + 1;
	      linebuffer = (char *) xrealloc (linebuffer, linelength);
	    }
	  strcpy (linebuffer, history_value);
	  p = linebuffer + strlen(linebuffer);
	  free (history_value);
	}
    }

  /* If we just got an empty line, and that is supposed
     to repeat the previous command, return the value in the
     global buffer.  */
  if (repeat)
    {
      if (p == linebuffer)
	return line;
      p1 = linebuffer;
      while (*p1 == ' ' || *p1 == '\t')
	p1++;
      if (!*p1)
	return line;
    }

  *p = 0;

  /* Add line to history if appropriate.  */
  if (instream == stdin
      && ISATTY (stdin) && *linebuffer)
    add_history (linebuffer);

  /* Note: lines consisting soley of comments are added to the command
     history.  This is useful when you type a command, and then
     realize you don't want to execute it quite yet.  You can comment
     out the command and then later fetch it from the value history
     and remove the '#'.  The kill ring is probably better, but some
     people are in the habit of commenting things out.  */
  p1 = linebuffer;
  while ((c = *p1++) != '\0')
    {
      if (c == '"')
	while ((c = *p1++) != '"')
	  {
	    /* Make sure an escaped '"' doesn't make us think the string
	       is ended.  */
	    if (c == '\\')
	      parse_escape (&p1);
	    if (c == '\0')
	      break;
	  }
      else if (c == '\'')
	while ((c = *p1++) != '\'')
	  {
	    /* Make sure an escaped '\'' doesn't make us think the string
	       is ended.  */
	    if (c == '\\')
	      parse_escape (&p1);
	    if (c == '\0')
	      break;
	  }
      else if (c == '#')
	{
	  /* Found a comment.  */
	  p1[-1] = '\0';
	  break;
	}
    }

  /* Save into global buffer if appropriate.  */
  if (repeat)
    {
      if (linelength > linesize)
	{
	  line = xrealloc (line, linelength);
	  linesize = linelength;
	}
      strcpy (line, linebuffer);
      return line;
    }

  return linebuffer;
}

/* Read lines from the input stream
   and accumulate them in a chain of struct command_line's
   which is then returned.  */

struct command_line *
read_command_lines ()
{
  struct command_line *first = 0;
  register struct command_line *next, *tail = 0;
  register char *p, *p1;
  struct cleanup *old_chain = 0;

  while (1)
    {
      dont_repeat ();
      p = command_line_input ((char *) NULL, instream == stdin);
      if (p == NULL)
	/* Treat end of file like "end".  */
	break;
      
      /* Remove leading and trailing blanks.  */
      while (*p == ' ' || *p == '\t') p++;
      p1 = p + strlen (p);
      while (p1 != p && (p1[-1] == ' ' || p1[-1] == '\t')) p1--;

      /* Is this "end"?  */
      if (p1 - p == 3 && !strncmp (p, "end", 3))
	break;

      /* No => add this line to the chain of command lines.  */
      next = (struct command_line *) xmalloc (sizeof (struct command_line));
      next->line = savestring (p, p1 - p);
      next->next = 0;
      if (tail)
	{
	  tail->next = next;
	}
      else
	{
	  /* We just read the first line.
	     From now on, arrange to throw away the lines we have
	     if we quit or get an error while inside this function.  */
	  first = next;
	  old_chain = make_cleanup (free_command_lines, &first);
	}
      tail = next;
    }

  dont_repeat ();

  /* Now we are about to return the chain to our caller,
     so freeing it becomes his responsibility.  */
  if (first)
    discard_cleanups (old_chain);
  return first;
}

/* Free a chain of struct command_line's.  */

void
free_command_lines (lptr)
      struct command_line **lptr;
{
  register struct command_line *l = *lptr;
  register struct command_line *next;

  while (l)
    {
      next = l->next;
      free (l->line);
      free ((PTR)l);
      l = next;
    }
}

/* Add an element to the list of info subcommands.  */

void
add_info (name, fun, doc)
     char *name;
     void (*fun) PARAMS ((char *, int));
     char *doc;
{
  add_cmd (name, no_class, fun, doc, &infolist);
}

/* Add an alias to the list of info subcommands.  */

void
add_info_alias (name, oldname, abbrev_flag)
     char *name;
     char *oldname;
     int abbrev_flag;
{
  add_alias_cmd (name, oldname, 0, abbrev_flag, &infolist);
}

/* The "info" command is defined as a prefix, with allow_unknown = 0.
   Therefore, its own definition is called only for "info" with no args.  */

/* ARGSUSED */
static void
info_command (arg, from_tty)
     char *arg;
     int from_tty;
{
  printf ("\"info\" must be followed by the name of an info command.\n");
  help_list (infolist, "info ", -1, stdout);
}

/* The "show" command with no arguments shows all the settings.  */

/* ARGSUSED */
static void
show_command (arg, from_tty)
     char *arg;
     int from_tty;
{
  cmd_show_list (showlist, from_tty, "");
}

/* Add an element to the list of commands.  */

void
add_com (name, class, fun, doc)
     char *name;
     enum command_class class;
     void (*fun) PARAMS ((char *, int));
     char *doc;
{
  add_cmd (name, class, fun, doc, &cmdlist);
}

/* Add an alias or abbreviation command to the list of commands.  */

void
add_com_alias (name, oldname, class, abbrev_flag)
     char *name;
     char *oldname;
     enum command_class class;
     int abbrev_flag;
{
  add_alias_cmd (name, oldname, class, abbrev_flag, &cmdlist);
}

void
error_no_arg (why)
     char *why;
{
  error ("Argument required (%s).", why);
}

/* ARGSUSED */
static void
help_command (command, from_tty)
     char *command;
     int from_tty; /* Ignored */
{
  help_cmd (command, stdout);
}

static void
validate_comname (comname)
     char *comname;
{
  register char *p;

  if (comname == 0)
    error_no_arg ("name of command to define");

  p = comname;
  while (*p)
    {
      if (!isalnum(*p) && *p != '-')
	error ("Junk in argument list: \"%s\"", p);
      p++;
    }
}

/* This is just a placeholder in the command data structures.  */
static void
user_defined_command (ignore, from_tty)
     char *ignore;
     int from_tty;
{
}

static void
define_command (comname, from_tty)
     char *comname;
     int from_tty;
{
  register struct command_line *cmds;
  register struct cmd_list_element *c, *newc, *hookc = 0;
  char *tem = comname;
#define	HOOK_STRING	"hook-"
#define	HOOK_LEN 5

  validate_comname (comname);

  /* Look it up, and verify that we got an exact match.  */
  c = lookup_cmd (&tem, cmdlist, "", -1, 1);
  if (c && !STREQ (comname, c->name))
    c = 0;
    
  if (c)
    {
      if (c->class == class_user || c->class == class_alias)
	tem = "Redefine command \"%s\"? ";
      else
	tem = "Really redefine built-in command \"%s\"? ";
      if (!query (tem, c->name))
	error ("Command \"%s\" not redefined.", c->name);
    }

  /* If this new command is a hook, then mark the command which it
     is hooking.  Note that we allow hooking `help' commands, so that
     we can hook the `stop' pseudo-command.  */

  if (!strncmp (comname, HOOK_STRING, HOOK_LEN))
    {
      /* Look up cmd it hooks, and verify that we got an exact match.  */
      tem = comname+HOOK_LEN;
      hookc = lookup_cmd (&tem, cmdlist, "", -1, 0);
      if (hookc && !STREQ (comname+HOOK_LEN, hookc->name))
	hookc = 0;
      if (!hookc)
	{
	  warning ("Your new `%s' command does not hook any existing command.",
		   comname);
	  if (!query ("Proceed? ", (char *)0))
	    error ("Not confirmed.");
	}
    }

  comname = savestring (comname, strlen (comname));

  /* If the rest of the commands will be case insensitive, this one 
     should behave in the same manner. */
  for (tem = comname; *tem; tem++)
    if (isupper(*tem)) *tem = tolower(*tem);

  if (from_tty)
    {
      printf ("Type commands for definition of \"%s\".\n\
End with a line saying just \"end\".\n", comname);
      fflush (stdout);
    }

  cmds = read_command_lines ();

  if (c && c->class == class_user)
    free_command_lines (&c->user_commands);

  newc = add_cmd (comname, class_user, user_defined_command,
	   (c && c->class == class_user)
	   ? c->doc : savestring ("User-defined.", 13), &cmdlist);
  newc->user_commands = cmds;

  /* If this new command is a hook, then mark both commands as being
     tied.  */
  if (hookc)
    {
      hookc->hook = newc;	/* Target gets hooked.  */
      newc->hookee = hookc;	/* We are marked as hooking target cmd.  */
    }
}

static void
document_command (comname, from_tty)
     char *comname;
     int from_tty;
{
  struct command_line *doclines;
  register struct cmd_list_element *c;
  char *tem = comname;

  validate_comname (comname);

  c = lookup_cmd (&tem, cmdlist, "", 0, 1);

  if (c->class != class_user)
    error ("Command \"%s\" is built-in.", comname);

  if (from_tty)
    printf ("Type documentation for \"%s\".\n\
End with a line saying just \"end\".\n", comname);

  doclines = read_command_lines ();

  if (c->doc) free (c->doc);

  {
    register struct command_line *cl1;
    register int len = 0;

    for (cl1 = doclines; cl1; cl1 = cl1->next)
      len += strlen (cl1->line) + 1;

    c->doc = (char *) xmalloc (len + 1);
    *c->doc = 0;

    for (cl1 = doclines; cl1; cl1 = cl1->next)
      {
	strcat (c->doc, cl1->line);
	if (cl1->next)
	  strcat (c->doc, "\n");
      }
  }

  free_command_lines (&doclines);
}

static void
print_gnu_advertisement()
{
    printf ("\
GDB is free software and you are welcome to distribute copies of it\n\
 under certain conditions; type \"show copying\" to see the conditions.\n\
There is absolutely no warranty for GDB; type \"show warranty\" for details.\n\
");
}

static void
print_gdb_version (stream)
  FILE *stream;
{
  fprintf_filtered (stream, "\
GDB %s (%s", version, host_canonical);

  if (strcmp(host_canonical, target_canonical))
    fprintf_filtered (stream, " --target %s", target_canonical);

  fprintf_filtered (stream, "), ");
  wrap_here("");
  fprintf_filtered (stream, "Copyright 1993 Free Software Foundation, Inc.");
}

/* ARGSUSED */
static void
show_version (args, from_tty)
     char *args;
     int from_tty;
{
  immediate_quit++;
  print_gnu_advertisement ();
  print_gdb_version (stdout);
  printf_filtered ("\n");
  immediate_quit--;
}

/* xgdb calls this to reprint the usual GDB prompt.  */

void
print_prompt ()
{
  printf ("%s", prompt);
  fflush (stdout);
}

static void
quit_command (args, from_tty)
     char *args;
     int from_tty;
{
  if (inferior_pid != 0 && target_has_execution)
    {
      if (attach_flag)
	{
	  if (query ("The program is running.  Quit anyway (and detach it)? "))
	    target_detach (args, from_tty);
	  else
	    error ("Not confirmed.");
	}
      else
	{
	  if (query ("The program is running.  Quit anyway (and kill it)? "))
	    target_kill ();
	  else
	    error ("Not confirmed.");
	}
    }
  /* Save the history information if it is appropriate to do so.  */
  if (write_history_p && history_filename)
    write_history (history_filename);
  exit (0);
}

/* Returns whether GDB is running on a terminal and whether the user
   desires that questions be asked of them on that terminal.  */

int
input_from_terminal_p ()
{
  return gdb_has_a_terminal () && (instream == stdin) & caution;
}

/* ARGSUSED */
static void
pwd_command (args, from_tty)
     char *args;
     int from_tty;
{
  if (args) error ("The \"pwd\" command does not take an argument: %s", args);
  getcwd (dirbuf, sizeof (dirbuf));

  if (!STREQ (dirbuf, current_directory))
    printf ("Working directory %s\n (canonically %s).\n",
	    current_directory, dirbuf);
  else
    printf ("Working directory %s.\n", current_directory);
}

static void
cd_command (dir, from_tty)
     char *dir;
     int from_tty;
{
  int len;
  /* Found something other than leading repetitions of "/..".  */
  int found_real_path;
  char *p;

  /* If the new directory is absolute, repeat is a no-op; if relative,
     repeat might be useful but is more likely to be a mistake.  */
  dont_repeat ();

  if (dir == 0)
    error_no_arg ("new working directory");

  dir = tilde_expand (dir);
  make_cleanup (free, dir);

  if (chdir (dir) < 0)
    perror_with_name (dir);

  len = strlen (dir);
  dir = savestring (dir, len - (len > 1 && dir[len-1] == '/'));
  if (dir[0] == '/')
    current_directory = dir;
  else
    {
      if (current_directory[0] == '/' && current_directory[1] == '\0')
	current_directory = concat (current_directory, dir, NULL);
      else
	current_directory = concat (current_directory, "/", dir, NULL);
      free (dir);
    }

  /* Now simplify any occurrences of `.' and `..' in the pathname.  */

  found_real_path = 0;
  for (p = current_directory; *p;)
    {
      if (p[0] == '/' && p[1] == '.' && (p[2] == 0 || p[2] == '/'))
	strcpy (p, p + 2);
      else if (p[0] == '/' && p[1] == '.' && p[2] == '.'
	       && (p[3] == 0 || p[3] == '/'))
	{
	  if (found_real_path)
	    {
	      /* Search backwards for the directory just before the "/.."
		 and obliterate it and the "/..".  */
	      char *q = p;
	      while (q != current_directory && q[-1] != '/')
		--q;

	      if (q == current_directory)
		/* current_directory is
		   a relative pathname ("can't happen"--leave it alone).  */
		++p;
	      else
		{
		  strcpy (q - 1, p + 3);
		  p = q - 1;
		}
	    }
	  else
	    /* We are dealing with leading repetitions of "/..", for example
	       "/../..", which is the Mach super-root.  */
	    p += 3;
	}
      else
	{
	  found_real_path = 1;
	  ++p;
	}
    }

  forget_cached_source_info ();

  if (from_tty)
    pwd_command ((char *) 0, 1);
}

/* ARGSUSED */
static void
source_command (args, from_tty)
     char *args;
     int from_tty;
{
  FILE *stream;
  struct cleanup *cleanups;
  char *file = args;

  if (file == NULL)
    {
      error ("source command requires pathname of file to source.");
    }

  file = tilde_expand (file);
  make_cleanup (free, file);

  stream = fopen (file, FOPEN_RT);
  if (stream == 0)
    perror_with_name (file);

  cleanups = make_cleanup (fclose, stream);

  read_command_file (stream);

  do_cleanups (cleanups);
}

/* ARGSUSED */
static void
echo_command (text, from_tty)
     char *text;
     int from_tty;
{
  char *p = text;
  register int c;

  if (text)
    while ((c = *p++) != '\0')
      {
	if (c == '\\')
	  {
	    /* \ at end of argument is used after spaces
	       so they won't be lost.  */
	    if (*p == 0)
	      return;

	    c = parse_escape (&p);
	    if (c >= 0)
	      printf_filtered ("%c", c);
	  }
	else
	  printf_filtered ("%c", c);
      }

  /* Force this output to appear now.  */
  wrap_here ("");
  fflush (stdout);
}


/* Functions to manipulate command line editing control variables.  */

/* Number of commands to print in each call to show_commands.  */
#define Hist_print 10
static void
show_commands (args, from_tty)
     char *args;
     int from_tty;
{
  /* Index for history commands.  Relative to history_base.  */
  int offset;

  /* Number of the history entry which we are planning to display next.
     Relative to history_base.  */
  static int num = 0;

  /* The first command in the history which doesn't exist (i.e. one more
     than the number of the last command).  Relative to history_base.  */
  int hist_len;

  extern struct _hist_entry *history_get PARAMS ((int));
  extern int history_base;

  /* Print out some of the commands from the command history.  */
  /* First determine the length of the history list.  */
  hist_len = history_size;
  for (offset = 0; offset < history_size; offset++)
    {
      if (!history_get (history_base + offset))
	{
	  hist_len = offset;
	  break;
	}
    }

  if (args)
    {
      if (args[0] == '+' && args[1] == '\0')
	/* "info editing +" should print from the stored position.  */
	;
      else
	/* "info editing <exp>" should print around command number <exp>.  */
	num = (parse_and_eval_address (args) - history_base) - Hist_print / 2;
    }
  /* "show commands" means print the last Hist_print commands.  */
  else
    {
      num = hist_len - Hist_print;
    }

  if (num < 0)
    num = 0;

  /* If there are at least Hist_print commands, we want to display the last
     Hist_print rather than, say, the last 6.  */
  if (hist_len - num < Hist_print)
    {
      num = hist_len - Hist_print;
      if (num < 0)
	num = 0;
    }

  for (offset = num; offset < num + Hist_print && offset < hist_len; offset++)
    {
      printf_filtered ("%5d  %s\n", history_base + offset,
	      (history_get (history_base + offset))->line);
    }

  /* The next command we want to display is the next one that we haven't
     displayed yet.  */
  num += Hist_print;
  
  /* If the user repeats this command with return, it should do what
     "show commands +" does.  This is unnecessary if arg is null,
     because "show commands +" is not useful after "show commands".  */
  if (from_tty && args)
    {
      args[0] = '+';
      args[1] = '\0';
    }
}

/* Called by do_setshow_command.  */
/* ARGSUSED */
static void
set_history_size_command (args, from_tty, c)
     char *args;
     int from_tty;
     struct cmd_list_element *c;
{
  if (history_size == INT_MAX)
    unstifle_history ();
  else if (history_size >= 0)
    stifle_history (history_size);
  else
    {
      history_size = INT_MAX;
      error ("History size must be non-negative");
    }
}

/* ARGSUSED */
static void
set_history (args, from_tty)
     char *args;
     int from_tty;
{
  printf ("\"set history\" must be followed by the name of a history subcommand.\n");
  help_list (sethistlist, "set history ", -1, stdout);
}

/* ARGSUSED */
static void
show_history (args, from_tty)
     char *args;
     int from_tty;
{
  cmd_show_list (showhistlist, from_tty, "");
}

int info_verbose = 0;		/* Default verbose msgs off */

/* Called by do_setshow_command.  An elaborate joke.  */
/* ARGSUSED */
static void 
set_verbose (args, from_tty, c)
     char *args;
     int from_tty;
     struct cmd_list_element *c;
{
  char *cmdname = "verbose";
  struct cmd_list_element *showcmd;
  
  showcmd = lookup_cmd_1 (&cmdname, showlist, NULL, 1);

  if (info_verbose)
    {
      c->doc = "Set verbose printing of informational messages.";
      showcmd->doc = "Show verbose printing of informational messages.";
    }
  else
    {
      c->doc = "Set verbosity.";
      showcmd->doc = "Show verbosity.";
    }
}

static void
float_handler (signo)
int signo;
{
  /* This message is based on ANSI C, section 4.7.  Note that integer
     divide by zero causes this, so "float" is a misnomer.  */
  signal (SIGFPE, float_handler);
  error ("Erroneous arithmetic operation.");
}

/* Return whether we are running a batch file or from terminal.  */
int
batch_mode ()
{
  return !(instream == stdin && ISATTY (stdin));
}


static void
init_cmd_lists ()
{
  cmdlist = NULL;
  infolist = NULL;
  enablelist = NULL;
  disablelist = NULL;
  deletelist = NULL;
  enablebreaklist = NULL;
  setlist = NULL;
  unsetlist = NULL;
  showlist = NULL;
  sethistlist = NULL;
  showhistlist = NULL;
  unsethistlist = NULL;
#if MAINTENANCE_CMDS
  maintenancelist = NULL;
  maintenanceinfolist = NULL;
  maintenanceprintlist = NULL;
#endif
  setprintlist = NULL;
  showprintlist = NULL;
  setchecklist = NULL;
  showchecklist = NULL;
}

/* Init the history buffer.  Note that we are called after the init file(s)
 * have been read so that the user can change the history file via his
 * .gdbinit file (for instance).  The GDBHISTFILE environment variable
 * overrides all of this.
 */

static void
init_history()
{
  char *tmpenv;

  tmpenv = getenv ("HISTSIZE");
  if (tmpenv)
    history_size = atoi (tmpenv);
  else if (!history_size)
    history_size = 256;

  stifle_history (history_size);

  tmpenv = getenv ("GDBHISTFILE");
  if (tmpenv)
    history_filename = savestring (tmpenv, strlen(tmpenv));
  else if (!history_filename) {
    /* We include the current directory so that if the user changes
       directories the file written will be the same as the one
       that was read.  */
    history_filename = concat (current_directory, "/.gdb_history", NULL);
  }
  read_history (history_filename);
}

static void
init_main ()
{
  struct cmd_list_element *c;
  
#ifdef DEFAULT_PROMPT
  prompt = savestring (DEFAULT_PROMPT, strlen(DEFAULT_PROMPT));
#else
  prompt = savestring ("(gdb) ", 6);
#endif

  /* Set the important stuff up for command editing.  */
  command_editing_p = 1;
  history_expansion_p = 0;
  write_history_p = 0;
  
  /* Setup important stuff for command line editing.  */
  rl_completion_entry_function = (int (*)()) symbol_completion_function;
  rl_completer_word_break_characters = gdb_completer_word_break_characters;
  rl_completer_quote_characters = gdb_completer_quote_characters;
  rl_readline_name = "gdb";

  /* Define the classes of commands.
     They will appear in the help list in the reverse of this order.  */

  add_cmd ("internals", class_maintenance, NO_FUNCTION,
	   "Maintenance commands.\n\
Some gdb commands are provided just for use by gdb maintainers.\n\
These commands are subject to frequent change, and may not be as\n\
well documented as user commands.",
	   &cmdlist);
  add_cmd ("obscure", class_obscure, NO_FUNCTION, "Obscure features.", &cmdlist);
  add_cmd ("aliases", class_alias, NO_FUNCTION, "Aliases of other commands.", &cmdlist);
  add_cmd ("user-defined", class_user, NO_FUNCTION, "User-defined commands.\n\
The commands in this class are those defined by the user.\n\
Use the \"define\" command to define a command.", &cmdlist);
  add_cmd ("support", class_support, NO_FUNCTION, "Support facilities.", &cmdlist);
  add_cmd ("status", class_info, NO_FUNCTION, "Status inquiries.", &cmdlist);
  add_cmd ("files", class_files, NO_FUNCTION, "Specifying and examining files.", &cmdlist);
  add_cmd ("breakpoints", class_breakpoint, NO_FUNCTION, "Making program stop at certain points.", &cmdlist);
  add_cmd ("data", class_vars, NO_FUNCTION, "Examining data.", &cmdlist);
  add_cmd ("stack", class_stack, NO_FUNCTION, "Examining the stack.\n\
The stack is made up of stack frames.  Gdb assigns numbers to stack frames\n\
counting from zero for the innermost (currently executing) frame.\n\n\
At any time gdb identifies one frame as the \"selected\" frame.\n\
Variable lookups are done with respect to the selected frame.\n\
When the program being debugged stops, gdb selects the innermost frame.\n\
The commands below can be used to select other frames by number or address.",
	   &cmdlist);
  add_cmd ("running", class_run, NO_FUNCTION, "Running the program.", &cmdlist);

  add_com ("pwd", class_files, pwd_command,
	   "Print working directory.  This is used for your program as well.");
  c = add_cmd ("cd", class_files, cd_command,
	   "Set working directory to DIR for debugger and program being debugged.\n\
The change does not take effect for the program being debugged\n\
until the next time it is started.", &cmdlist);
  c->completer = filename_completer;

  add_show_from_set
    (add_set_cmd ("prompt", class_support, var_string, (char *)&prompt,
	   "Set gdb's prompt",
	   &setlist),
     &showlist);
  
  add_com ("echo", class_support, echo_command,
	   "Print a constant string.  Give string as argument.\n\
C escape sequences may be used in the argument.\n\
No newline is added at the end of the argument;\n\
use \"\\n\" if you want a newline to be printed.\n\
Since leading and trailing whitespace are ignored in command arguments,\n\
if you want to print some you must use \"\\\" before leading whitespace\n\
to be printed or after trailing whitespace.");
  add_com ("document", class_support, document_command,
	   "Document a user-defined command.\n\
Give command name as argument.  Give documentation on following lines.\n\
End with a line of just \"end\".");
  add_com ("define", class_support, define_command,
	   "Define a new command name.  Command name is argument.\n\
Definition appears on following lines, one command per line.\n\
End with a line of just \"end\".\n\
Use the \"document\" command to give documentation for the new command.\n\
Commands defined in this way do not take arguments.");

#ifdef __STDC__
  c = add_cmd ("source", class_support, source_command,
	   "Read commands from a file named FILE.\n\
Note that the file \"" GDBINIT_FILENAME "\" is read automatically in this way\n\
when gdb is started.", &cmdlist);
#else
  /* Punt file name, we can't help it easily.  */
  c = add_cmd ("source", class_support, source_command,
	   "Read commands from a file named FILE.\n\
Note that the file \".gdbinit\" is read automatically in this way\n\
when gdb is started.", &cmdlist);
#endif
  c->completer = filename_completer;

  add_com ("quit", class_support, quit_command, "Exit gdb.");
  add_com ("help", class_support, help_command, "Print list of commands.");
  add_com_alias ("q", "quit", class_support, 1);
  add_com_alias ("h", "help", class_support, 1);


  c = add_set_cmd ("verbose", class_support, var_boolean, (char *)&info_verbose,
		   "Set ",
		   &setlist),
  add_show_from_set (c, &showlist);
  c->function.sfunc = set_verbose;
  set_verbose (NULL, 0, c);
  
  add_show_from_set
    (add_set_cmd ("editing", class_support, var_boolean, (char *)&command_editing_p,
	   "Set editing of command lines as they are typed.\n\
Use \"on\" to enable to enable the editing, and \"off\" to disable it.\n\
Without an argument, command line editing is enabled.  To edit, use\n\
EMACS-like or VI-like commands like control-P or ESC.", &setlist),
     &showlist);

  add_prefix_cmd ("history", class_support, set_history,
		  "Generic command for setting command history parameters.",
		  &sethistlist, "set history ", 0, &setlist);
  add_prefix_cmd ("history", class_support, show_history,
		  "Generic command for showing command history parameters.",
		  &showhistlist, "show history ", 0, &showlist);

  add_show_from_set
    (add_set_cmd ("expansion", no_class, var_boolean, (char *)&history_expansion_p,
	   "Set history expansion on command input.\n\
Without an argument, history expansion is enabled.", &sethistlist),
     &showhistlist);

  add_show_from_set
    (add_set_cmd ("save", no_class, var_boolean, (char *)&write_history_p,
	   "Set saving of the history record on exit.\n\
Use \"on\" to enable to enable the saving, and \"off\" to disable it.\n\
Without an argument, saving is enabled.", &sethistlist),
     &showhistlist);

  c = add_set_cmd ("size", no_class, var_integer, (char *)&history_size,
		   "Set the size of the command history, \n\
ie. the number of previous commands to keep a record of.", &sethistlist);
  add_show_from_set (c, &showhistlist);
  c->function.sfunc = set_history_size_command;

  add_show_from_set
    (add_set_cmd ("filename", no_class, var_filename, (char *)&history_filename,
	   "Set the filename in which to record the command history\n\
 (the list of previous commands of which a record is kept).", &sethistlist),
     &showhistlist);

  add_show_from_set
    (add_set_cmd ("confirm", class_support, var_boolean,
		  (char *)&caution,
		  "Set whether to confirm potentially dangerous operations.",
		  &setlist),
     &showlist);

  add_prefix_cmd ("info", class_info, info_command,
        "Generic command for showing things about the program being debugged.",
		  &infolist, "info ", 0, &cmdlist);
  add_com_alias ("i", "info", class_info, 1);

  add_prefix_cmd ("show", class_info, show_command,
		  "Generic command for showing things about the debugger.",
		  &showlist, "show ", 0, &cmdlist);
  /* Another way to get at the same thing.  */
  add_info ("set", show_command, "Show all GDB settings.");

  add_cmd ("commands", no_class, show_commands,
	   "Show the the history of commands you typed.\n\
You can supply a command number to start with, or a `+' to start after\n\
the previous command number shown.",
	   &showlist);

  add_cmd ("version", no_class, show_version,
	   "Show what version of GDB this is.", &showlist);

  add_show_from_set (
    add_set_cmd ("remotedebug", no_class, var_boolean, (char *)&remote_debug,
		   "Set debugging of remote protocol.\n\
When enabled, each packet sent or received with the remote target\n\
is displayed.", &setlist),
		     &showlist);
}