aboutsummaryrefslogtreecommitdiff
path: root/mach/mig_strncpy.c
blob: b0c001d7756f0a5df55983ac7cb4b2d16cf38331 (plain) 
1
2
3
4
5
6
7
8
9
10
11

/* Silly pointless function MiG needs.  */

#include <mach.h>
#include <string.h>

vm_size_t
__mig_strncpy (char *dst, const char *src, vm_size_t len)
{
  return __stpncpy (dst, src, len) - dst;
}
weak_alias (__mig_strncpy, mig_strncpy)
generated by cgit v1.1 at 2024-12-21 00:34:45 +0000
s/ppalka/readline-6.3-update'>users/ppalka/readline-6.3-update Unnamed repository; edit this file 'description' to name the repository.root
aboutsummaryrefslogtreecommitdiff
path: root/gdb/gnu-regex.c
blob: f7faa8c864730a4e27cf6a7dca276626984be5c3 (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
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803

/* *INDENT-OFF* */ /* keep in sync with glibc */
/* Extended regular expression matching and search library,
   version 0.12.
   (Implements POSIX draft P1003.2/D11.2, except for some of the
   internationalization features.)
   Copyright (C) 1993, 94, 95, 96, 97, 98 Free Software Foundation, Inc.

   NOTE: The canonical source of this file is maintained with the 
   GNU C Library.  Bugs can be reported to bug-glibc@gnu.org.

   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, or (at your option) any
   later version.

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

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

/* AIX requires this to be the first thing in the file. */
#if defined _AIX && !defined REGEX_MALLOC
  #pragma alloca
#endif

#undef	_GNU_SOURCE
#define _GNU_SOURCE

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#ifndef PARAMS
# if defined __GNUC__ || (defined __STDC__ && __STDC__)
#  define PARAMS(args) args
# else
#  define PARAMS(args) ()
# endif  /* GCC.  */
#endif  /* Not PARAMS.  */

#if defined STDC_HEADERS && !defined emacs
# include <stddef.h>
#else
/* We need this for `gnu-regex.h', and perhaps for the Emacs include files.  */
# include <sys/types.h>
#endif

/* For platform which support the ISO C amendement 1 functionality we
   support user defined character classes.  */
#if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H)
 /* Solaris 2.5 has a bug: <wchar.h> must be included before <wctype.h>.  */
# include <wchar.h>
# include <wctype.h>
#endif

/* This is for other GNU distributions with internationalized messages.  */
/* CYGNUS LOCAL: ../intl will handle this for us */
#ifdef ENABLE_NLS
# include <libintl.h>
#else
# define gettext(msgid) (msgid)
#endif

#ifndef gettext_noop
/* This define is so xgettext can find the internationalizable
   strings.  */
# define gettext_noop(String) String
#endif

/* The `emacs' switch turns on certain matching commands
   that make sense only in Emacs. */
#ifdef emacs

# include "lisp.h"
# include "buffer.h"
# include "syntax.h"

#else  /* not emacs */

/* If we are not linking with Emacs proper,
   we can't use the relocating allocator
   even if config.h says that we can.  */
# undef REL_ALLOC

# if defined STDC_HEADERS || defined _LIBC
#  include <stdlib.h>
# else
char *malloc ();
char *realloc ();
# endif

/* When used in Emacs's lib-src, we need to get bzero and bcopy somehow.
   If nothing else has been done, use the method below.  */
# ifdef INHIBIT_STRING_HEADER
#  if !(defined HAVE_BZERO && defined HAVE_BCOPY)
#   if !defined bzero && !defined bcopy
#    undef INHIBIT_STRING_HEADER
#   endif
#  endif
# endif

/* This is the normal way of making sure we have a bcopy and a bzero.
   This is used in most programs--a few other programs avoid this
   by defining INHIBIT_STRING_HEADER.  */
# ifndef INHIBIT_STRING_HEADER
#  if defined HAVE_STRING_H || defined STDC_HEADERS || defined _LIBC
#   include <string.h>
#   ifndef bzero
#    ifndef _LIBC
#     define bzero(s, n)	(memset (s, '\0', n), (s))
#    else
#     define bzero(s, n)	__bzero (s, n)
#    endif
#   endif
#  else
#   include <strings.h>
#   ifndef memcmp
#    define memcmp(s1, s2, n)	bcmp (s1, s2, n)
#   endif
#   ifndef memcpy
#    define memcpy(d, s, n)	(bcopy (s, d, n), (d))
#   endif
#  endif
# endif

/* Define the syntax stuff for \<, \>, etc.  */

/* This must be nonzero for the wordchar and notwordchar pattern
   commands in re_match_2.  */
# ifndef Sword
#  define Sword 1
# endif

# ifdef SWITCH_ENUM_BUG
#  define SWITCH_ENUM_CAST(x) ((int)(x))
# else
#  define SWITCH_ENUM_CAST(x) (x)
# endif

/* How many characters in the character set.  */
# define CHAR_SET_SIZE 256

/* GDB LOCAL: define _REGEX_RE_COMP to get BSD style re_comp and re_exec */
#ifndef _REGEX_RE_COMP
#define _REGEX_RE_COMP
#endif

# ifdef SYNTAX_TABLE

extern char *re_syntax_table;

# else /* not SYNTAX_TABLE */

static char re_syntax_table[CHAR_SET_SIZE];

static void
init_syntax_once ()
{
   register int c;
   static int done = 0;

   if (done)
     return;

   bzero (re_syntax_table, sizeof re_syntax_table);

   for (c = 'a'; c <= 'z'; c++)
     re_syntax_table[c] = Sword;

   for (c = 'A'; c <= 'Z'; c++)
     re_syntax_table[c] = Sword;

   for (c = '0'; c <= '9'; c++)
     re_syntax_table[c] = Sword;

   re_syntax_table['_'] = Sword;

   done = 1;
}

# endif /* not SYNTAX_TABLE */

# define SYNTAX(c) re_syntax_table[c]

#endif /* not emacs */

/* Get the interface, including the syntax bits.  */
/* CYGNUS LOCAL: call it gnu-regex.h, not regex.h, to avoid name conflicts */
#include "gnu-regex.h"

/* isalpha etc. are used for the character classes.  */
#include <ctype.h>

/* Jim Meyering writes:

   "... Some ctype macros are valid only for character codes that
   isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
   using /bin/cc or gcc but without giving an ansi option).  So, all
   ctype uses should be through macros like ISPRINT...  If
   STDC_HEADERS is defined, then autoconf has verified that the ctype
   macros don't need to be guarded with references to isascii. ...
   Defining isascii to 1 should let any compiler worth its salt
   eliminate the && through constant folding."
   Solaris defines some of these symbols so we must undefine them first.  */

#undef ISASCII
#if defined STDC_HEADERS || (!defined isascii && !defined HAVE_ISASCII)
# define ISASCII(c) 1
#else
# define ISASCII(c) isascii(c)
#endif

#ifdef isblank
# define ISBLANK(c) (ISASCII (c) && isblank (c))
#else
# define ISBLANK(c) ((c) == ' ' || (c) == '\t')
#endif
#ifdef isgraph
# define ISGRAPH(c) (ISASCII (c) && isgraph (c))
#else
# define ISGRAPH(c) (ISASCII (c) && isprint (c) && !isspace (c))
#endif

#undef ISPRINT
#define ISPRINT(c) (ISASCII (c) && isprint (c))
#define ISDIGIT(c) (ISASCII (c) && isdigit (c))
#define ISALNUM(c) (ISASCII (c) && isalnum (c))
#define ISALPHA(c) (ISASCII (c) && isalpha (c))
#define ISCNTRL(c) (ISASCII (c) && iscntrl (c))
#define ISLOWER(c) (ISASCII (c) && islower (c))
#define ISPUNCT(c) (ISASCII (c) && ispunct (c))
#define ISSPACE(c) (ISASCII (c) && isspace (c))
#define ISUPPER(c) (ISASCII (c) && isupper (c))
#define ISXDIGIT(c) (ISASCII (c) && isxdigit (c))

#ifndef NULL
# define NULL (void *)0
#endif

/* We remove any previous definition of `SIGN_EXTEND_CHAR',
   since ours (we hope) works properly with all combinations of
   machines, compilers, `char' and `unsigned char' argument types.
   (Per Bothner suggested the basic approach.)  */
#undef SIGN_EXTEND_CHAR
#if __STDC__
# define SIGN_EXTEND_CHAR(c) ((signed char) (c))
#else  /* not __STDC__ */
/* As in Harbison and Steele.  */
# define SIGN_EXTEND_CHAR(c) ((((unsigned char) (c)) ^ 128) - 128)
#endif

/* Should we use malloc or alloca?  If REGEX_MALLOC is not defined, we
   use `alloca' instead of `malloc'.  This is because using malloc in
   re_search* or re_match* could cause memory leaks when C-g is used in
   Emacs; also, malloc is slower and causes storage fragmentation.  On
   the other hand, malloc is more portable, and easier to debug.

   Because we sometimes use alloca, some routines have to be macros,
   not functions -- `alloca'-allocated space disappears at the end of the
   function it is called in.  */

#ifdef REGEX_MALLOC

# define REGEX_ALLOCATE malloc
# define REGEX_REALLOCATE(source, osize, nsize) realloc (source, nsize)
# define REGEX_FREE free

#else /* not REGEX_MALLOC  */

/* Emacs already defines alloca, sometimes.  */
# ifndef alloca

/* Make alloca work the best possible way.  */
#  ifdef __GNUC__
#   define alloca __builtin_alloca
#  else /* not __GNUC__ */
#   if HAVE_ALLOCA_H
#    include <alloca.h>
#   endif /* HAVE_ALLOCA_H */
#  endif /* not __GNUC__ */

# endif /* not alloca */

# define REGEX_ALLOCATE alloca

/* Assumes a `char *destination' variable.  */
# define REGEX_REALLOCATE(source, osize, nsize)				\
  (destination = (char *) alloca (nsize),				\
   memcpy (destination, source, osize))

/* No need to do anything to free, after alloca.  */
# define REGEX_FREE(arg) ((void)0) /* Do nothing!  But inhibit gcc warning.  */

#endif /* not REGEX_MALLOC */

/* Define how to allocate the failure stack.  */

#if defined REL_ALLOC && defined REGEX_MALLOC

# define REGEX_ALLOCATE_STACK(size)				\
  r_alloc (&failure_stack_ptr, (size))
# define REGEX_REALLOCATE_STACK(source, osize, nsize)		\
  r_re_alloc (&failure_stack_ptr, (nsize))
# define REGEX_FREE_STACK(ptr)					\
  r_alloc_free (&failure_stack_ptr)

#else /* not using relocating allocator */

# ifdef REGEX_MALLOC

#  define REGEX_ALLOCATE_STACK malloc
#  define REGEX_REALLOCATE_STACK(source, osize, nsize) realloc (source, nsize)
#  define REGEX_FREE_STACK free

# else /* not REGEX_MALLOC */

#  define REGEX_ALLOCATE_STACK alloca

#  define REGEX_REALLOCATE_STACK(source, osize, nsize)			\
   REGEX_REALLOCATE (source, osize, nsize)
/* No need to explicitly free anything.  */
#  define REGEX_FREE_STACK(arg)

# endif /* not REGEX_MALLOC */
#endif /* not using relocating allocator */


/* True if `size1' is non-NULL and PTR is pointing anywhere inside
   `string1' or just past its end.  This works if PTR is NULL, which is
   a good thing.  */
#define FIRST_STRING_P(ptr) 					\
  (size1 && string1 <= (ptr) && (ptr) <= string1 + size1)

/* (Re)Allocate N items of type T using malloc, or fail.  */
#define TALLOC(n, t) ((t *) malloc ((n) * sizeof (t)))
#define RETALLOC(addr, n, t) ((addr) = (t *) realloc (addr, (n) * sizeof (t)))
#define RETALLOC_IF(addr, n, t) \
  if (addr) RETALLOC((addr), (n), t); else (addr) = TALLOC ((n), t)
#define REGEX_TALLOC(n, t) ((t *) REGEX_ALLOCATE ((n) * sizeof (t)))

#define BYTEWIDTH 8 /* In bits.  */

#define STREQ(s1, s2) ((strcmp (s1, s2) == 0))

#undef MAX
#undef MIN
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#define MIN(a, b) ((a) < (b) ? (a) : (b))

typedef char boolean;
#define false 0
#define true 1

static int re_match_2_internal PARAMS ((struct re_pattern_buffer *bufp,
					const char *string1, int size1,
					const char *string2, int size2,
					int pos,
					struct re_registers *regs,
					int stop));

/* These are the command codes that appear in compiled regular
   expressions.  Some opcodes are followed by argument bytes.  A
   command code can specify any interpretation whatsoever for its
   arguments.  Zero bytes may appear in the compiled regular expression.  */

typedef enum
{
  no_op = 0,

  /* Succeed right away--no more backtracking.  */
  succeed,

        /* Followed by one byte giving n, then by n literal bytes.  */
  exactn,

        /* Matches any (more or less) character.  */
  anychar,

        /* Matches any one char belonging to specified set.  First
           following byte is number of bitmap bytes.  Then come bytes
           for a bitmap saying which chars are in.  Bits in each byte
           are ordered low-bit-first.  A character is in the set if its
           bit is 1.  A character too large to have a bit in the map is
           automatically not in the set.  */
  charset,

        /* Same parameters as charset, but match any character that is
           not one of those specified.  */
  charset_not,

        /* Start remembering the text that is matched, for storing in a
           register.  Followed by one byte with the register number, in
           the range 0 to one less than the pattern buffer's re_nsub
           field.  Then followed by one byte with the number of groups
           inner to this one.  (This last has to be part of the
           start_memory only because we need it in the on_failure_jump
           of re_match_2.)  */
  start_memory,

        /* Stop remembering the text that is matched and store it in a
           memory register.  Followed by one byte with the register
           number, in the range 0 to one less than `re_nsub' in the
           pattern buffer, and one byte with the number of inner groups,
           just like `start_memory'.  (We need the number of inner
           groups here because we don't have any easy way of finding the
           corresponding start_memory when we're at a stop_memory.)  */
  stop_memory,

        /* Match a duplicate of something remembered. Followed by one
           byte containing the register number.  */
  duplicate,

        /* Fail unless at beginning of line.  */
  begline,

        /* Fail unless at end of line.  */
  endline,

        /* Succeeds if at beginning of buffer (if emacs) or at beginning
           of string to be matched (if not).  */
  begbuf,

        /* Analogously, for end of buffer/string.  */
  endbuf,

        /* Followed by two byte relative address to which to jump.  */
  jump,

	/* Same as jump, but marks the end of an alternative.  */
  jump_past_alt,

        /* Followed by two-byte relative address of place to resume at
           in case of failure.  */
  on_failure_jump,

        /* Like on_failure_jump, but pushes a placeholder instead of the
           current string position when executed.  */
  on_failure_keep_string_jump,

        /* Throw away latest failure point and then jump to following
           two-byte relative address.  */
  pop_failure_jump,

        /* Change to pop_failure_jump if know won't have to backtrack to
           match; otherwise change to jump.  This is used to jump
           back to the beginning of a repeat.  If what follows this jump
           clearly won't match what the repeat does, such that we can be
           sure that there is no use backtracking out of repetitions
           already matched, then we change it to a pop_failure_jump.
           Followed by two-byte address.  */
  maybe_pop_jump,

        /* Jump to following two-byte address, and push a dummy failure
           point. This failure point will be thrown away if an attempt
           is made to use it for a failure.  A `+' construct makes this
           before the first repeat.  Also used as an intermediary kind
           of jump when compiling an alternative.  */
  dummy_failure_jump,

	/* Push a dummy failure point and continue.  Used at the end of
	   alternatives.  */
  push_dummy_failure,

        /* Followed by two-byte relative address and two-byte number n.
           After matching N times, jump to the address upon failure.  */
  succeed_n,

        /* Followed by two-byte relative address, and two-byte number n.
           Jump to the address N times, then fail.  */
  jump_n,

        /* Set the following two-byte relative address to the
           subsequent two-byte number.  The address *includes* the two
           bytes of number.  */
  set_number_at,

  wordchar,	/* Matches any word-constituent character.  */
  notwordchar,	/* Matches any char that is not a word-constituent.  */

  wordbeg,	/* Succeeds if at word beginning.  */
  wordend,	/* Succeeds if at word end.  */

  wordbound,	/* Succeeds if at a word boundary.  */
  notwordbound	/* Succeeds if not at a word boundary.  */

#ifdef emacs
  ,before_dot,	/* Succeeds if before point.  */
  at_dot,	/* Succeeds if at point.  */
  after_dot,	/* Succeeds if after point.  */

	/* Matches any character whose syntax is specified.  Followed by
           a byte which contains a syntax code, e.g., Sword.  */
  syntaxspec,

	/* Matches any character whose syntax is not that specified.  */
  notsyntaxspec
#endif /* emacs */
} re_opcode_t;

/* Common operations on the compiled pattern.  */

/* Store NUMBER in two contiguous bytes starting at DESTINATION.  */

#define STORE_NUMBER(destination, number)				\
  do {									\
    (destination)[0] = (number) & 0377;					\
    (destination)[1] = (number) >> 8;					\
  } while (0)

/* Same as STORE_NUMBER, except increment DESTINATION to
   the byte after where the number is stored.  Therefore, DESTINATION
   must be an lvalue.  */

#define STORE_NUMBER_AND_INCR(destination, number)			\
  do {									\
    STORE_NUMBER (destination, number);					\
    (destination) += 2;							\
  } while (0)

/* Put into DESTINATION a number stored in two contiguous bytes starting
   at SOURCE.  */

#define EXTRACT_NUMBER(destination, source)				\
  do {									\
    (destination) = *(source) & 0377;					\
    (destination) += SIGN_EXTEND_CHAR (*((source) + 1)) << 8;		\
  } while (0)

#ifdef DEBUG
static void extract_number _RE_ARGS ((int *dest, unsigned char *source));
static void
extract_number (dest, source)
    int *dest;
    unsigned char *source;
{
  int temp = SIGN_EXTEND_CHAR (*(source + 1));
  *dest = *source & 0377;
  *dest += temp << 8;
}

# ifndef EXTRACT_MACROS /* To debug the macros.  */
#  undef EXTRACT_NUMBER
#  define EXTRACT_NUMBER(dest, src) extract_number (&dest, src)
# endif /* not EXTRACT_MACROS */

#endif /* DEBUG */

/* Same as EXTRACT_NUMBER, except increment SOURCE to after the number.
   SOURCE must be an lvalue.  */

#define EXTRACT_NUMBER_AND_INCR(destination, source)			\
  do {									\
    EXTRACT_NUMBER (destination, source);				\
    (source) += 2; 							\
  } while (0)

#ifdef DEBUG
static void extract_number_and_incr _RE_ARGS ((int *destination,
					       unsigned char **source));
static void
extract_number_and_incr (destination, source)
    int *destination;
    unsigned char **source;
{
  extract_number (destination, *source);
  *source += 2;
}

# ifndef EXTRACT_MACROS
#  undef EXTRACT_NUMBER_AND_INCR
#  define EXTRACT_NUMBER_AND_INCR(dest, src) \
  extract_number_and_incr (&dest, &src)
# endif /* not EXTRACT_MACROS */

#endif /* DEBUG */

/* If DEBUG is defined, Regex prints many voluminous messages about what
   it is doing (if the variable `debug' is nonzero).  If linked with the
   main program in `iregex.c', you can enter patterns and strings
   interactively.  And if linked with the main program in `main.c' and
   the other test files, you can run the already-written tests.  */

#ifdef DEBUG

/* We use standard I/O for debugging.  */
# include <stdio.h>

/* It is useful to test things that ``must'' be true when debugging.  */
# include <assert.h>

static int debug = 0;

# define DEBUG_STATEMENT(e) e
# define DEBUG_PRINT1(x) if (debug) printf (x)
# define DEBUG_PRINT2(x1, x2) if (debug) printf (x1, x2)
# define DEBUG_PRINT3(x1, x2, x3) if (debug) printf (x1, x2, x3)
# define DEBUG_PRINT4(x1, x2, x3, x4) if (debug) printf (x1, x2, x3, x4)
# define DEBUG_PRINT_COMPILED_PATTERN(p, s, e) 				\
  if (debug) print_partial_compiled_pattern (s, e)
# define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)			\
  if (debug) print_double_string (w, s1, sz1, s2, sz2)


/* Print the fastmap in human-readable form.  */

void
print_fastmap (fastmap)
    char *fastmap;
{
  unsigned was_a_range = 0;
  unsigned i = 0;

  while (i < (1 << BYTEWIDTH))
    {
      if (fastmap[i++])
	{
	  was_a_range = 0;
          putchar (i - 1);
          while (i < (1 << BYTEWIDTH)  &&  fastmap[i])
            {
              was_a_range = 1;
              i++;
            }
	  if (was_a_range)
            {
              printf ("-");
              putchar (i - 1);
            }
        }
    }
  putchar ('\n');
}


/* Print a compiled pattern string in human-readable form, starting at
   the START pointer into it and ending just before the pointer END.  */

void
print_partial_compiled_pattern (start, end)
    unsigned char *start;
    unsigned char *end;
{
  int mcnt, mcnt2;
  unsigned char *p1;
  unsigned char *p = start;
  unsigned char *pend = end;

  if (start == NULL)
    {
      printf ("(null)\n");
      return;
    }

  /* Loop over pattern commands.  */
  while (p < pend)
    {
      printf ("%d:\t", p - start);

      switch ((re_opcode_t) *p++)
	{
        case no_op:
          printf ("/no_op");
          break;

	case exactn:
	  mcnt = *p++;
          printf ("/exactn/%d", mcnt);
          do
	    {
              putchar ('/');
	      putchar (*p++);
            }
          while (--mcnt);
          break;

	case start_memory:
          mcnt = *p++;
          printf ("/start_memory/%d/%d", mcnt, *p++);
          break;

	case stop_memory:
          mcnt = *p++;
	  printf ("/stop_memory/%d/%d", mcnt, *p++);
          break;

	case duplicate:
	  printf ("/duplicate/%d", *p++);
	  break;

	case anychar:
	  printf ("/anychar");
	  break;

	case charset:
        case charset_not:
          {
            register int c, last = -100;
	    register int in_range = 0;

	    printf ("/charset [%s",
	            (re_opcode_t) *(p - 1) == charset_not ? "^" : "");

            assert (p + *p < pend);

            for (c = 0; c < 256; c++)
	      if (c / 8 < *p
		  && (p[1 + (c/8)] & (1 << (c % 8))))
		{
		  /* Are we starting a range?  */
		  if (last + 1 == c && ! in_range)
		    {
		      putchar ('-');
		      in_range = 1;
		    }
		  /* Have we broken a range?  */
		  else if (last + 1 != c && in_range)
              {
		      putchar (last);
		      in_range = 0;
		    }

		  if (! in_range)
		    putchar (c);

		  last = c;
              }

	    if (in_range)
	      putchar (last);

	    putchar (']');

	    p += 1 + *p;
	  }
	  break;

	case begline:
	  printf ("/begline");
          break;

	case endline:
          printf ("/endline");
          break;

	case on_failure_jump:
          extract_number_and_incr (&mcnt, &p);
  	  printf ("/on_failure_jump to %d", p + mcnt - start);
          break;

	case on_failure_keep_string_jump:
          extract_number_and_incr (&mcnt, &p);
  	  printf ("/on_failure_keep_string_jump to %d", p + mcnt - start);
          break;

	case dummy_failure_jump:
          extract_number_and_incr (&mcnt, &p);
  	  printf ("/dummy_failure_jump to %d", p + mcnt - start);
          break;

	case push_dummy_failure:
          printf ("/push_dummy_failure");
          break;

        case maybe_pop_jump:
          extract_number_and_incr (&mcnt, &p);
  	  printf ("/maybe_pop_jump to %d", p + mcnt - start);
	  break;

        case pop_failure_jump:
	  extract_number_and_incr (&mcnt, &p);
  	  printf ("/pop_failure_jump to %d", p + mcnt - start);
	  break;

        case jump_past_alt:
	  extract_number_and_incr (&mcnt, &p);
  	  printf ("/jump_past_alt to %d", p + mcnt - start);
	  break;

        case jump:
	  extract_number_and_incr (&mcnt, &p);
  	  printf ("/jump to %d", p + mcnt - start);
	  break;

        case succeed_n:
          extract_number_and_incr (&mcnt, &p);
	  p1 = p + mcnt;
          extract_number_and_incr (&mcnt2, &p);
	  printf ("/succeed_n to %d, %d times", p1 - start, mcnt2);
          break;

        case jump_n:
          extract_number_and_incr (&mcnt, &p);
	  p1 = p + mcnt;
          extract_number_and_incr (&mcnt2, &p);
	  printf ("/jump_n to %d, %d times", p1 - start, mcnt2);
          break;

        case set_number_at:
          extract_number_and_incr (&mcnt, &p);
	  p1 = p + mcnt;
          extract_number_and_incr (&mcnt2, &p);
	  printf ("/set_number_at location %d to %d", p1 - start, mcnt2);
          break;

        case wordbound:
	  printf ("/wordbound");
	  break;

	case notwordbound:
	  printf ("/notwordbound");
          break;

	case wordbeg:
	  printf ("/wordbeg");
	  break;

	case wordend:
	  printf ("/wordend");

# ifdef emacs
	case before_dot:
	  printf ("/before_dot");
          break;

	case at_dot:
	  printf ("/at_dot");
          break;

	case after_dot:
	  printf ("/after_dot");
          break;

	case syntaxspec:
          printf ("/syntaxspec");
	  mcnt = *p++;
	  printf ("/%d", mcnt);
          break;

	case notsyntaxspec:
          printf ("/notsyntaxspec");
	  mcnt = *p++;
	  printf ("/%d", mcnt);
	  break;
# endif /* emacs */

	case wordchar:
	  printf ("/wordchar");
          break;

	case notwordchar:
	  printf ("/notwordchar");
          break;

	case begbuf:
	  printf ("/begbuf");
          break;

	case endbuf:
	  printf ("/endbuf");
          break;

        default:
          printf ("?%d", *(p-1));
	}

      putchar ('\n');
    }

  printf ("%d:\tend of pattern.\n", p - start);
}


void
print_compiled_pattern (bufp)
    struct re_pattern_buffer *bufp;
{
  unsigned char *buffer = bufp->buffer;

  print_partial_compiled_pattern (buffer, buffer + bufp->used);
  printf ("%ld bytes used/%ld bytes allocated.\n",
	  bufp->used, bufp->allocated);

  if (bufp->fastmap_accurate && bufp->fastmap)
    {
      printf ("fastmap: ");
      print_fastmap (bufp->fastmap);
    }

  printf ("re_nsub: %d\t", bufp->re_nsub);
  printf ("regs_alloc: %d\t", bufp->regs_allocated);
  printf ("can_be_null: %d\t", bufp->can_be_null);
  printf ("newline_anchor: %d\n", bufp->newline_anchor);
  printf ("no_sub: %d\t", bufp->no_sub);
  printf ("not_bol: %d\t", bufp->not_bol);
  printf ("not_eol: %d\t", bufp->not_eol);
  printf ("syntax: %lx\n", bufp->syntax);
  /* Perhaps we should print the translate table?  */
}


void
print_double_string (where, string1, size1, string2, size2)
    const char *where;
    const char *string1;
    const char *string2;
    int size1;
    int size2;
{
  int this_char;

  if (where == NULL)
    printf ("(null)");
  else
    {
      if (FIRST_STRING_P (where))
        {
          for (this_char = where - string1; this_char < size1; this_char++)
            putchar (string1[this_char]);

          where = string2;
        }

      for (this_char = where - string2; this_char < size2; this_char++)
        putchar (string2[this_char]);
    }
}

void
printchar (c)
     int c;
{
  putc (c, stderr);
}

#else /* not DEBUG */

# undef assert
# define assert(e)

# define DEBUG_STATEMENT(e)
# define DEBUG_PRINT1(x)
# define DEBUG_PRINT2(x1, x2)
# define DEBUG_PRINT3(x1, x2, x3)
# define DEBUG_PRINT4(x1, x2, x3, x4)
# define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
# define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)

#endif /* not DEBUG */

/* Set by `re_set_syntax' to the current regexp syntax to recognize.  Can
   also be assigned to arbitrarily: each pattern buffer stores its own
   syntax, so it can be changed between regex compilations.  */
/* This has no initializer because initialized variables in Emacs
   become read-only after dumping.  */
reg_syntax_t re_syntax_options;


/* Specify the precise syntax of regexps for compilation.  This provides
   for compatibility for various utilities which historically have
   different, incompatible syntaxes.

   The argument SYNTAX is a bit mask comprised of the various bits
   defined in gnu-regex.h.  We return the old syntax.  */

reg_syntax_t
re_set_syntax (syntax)
    reg_syntax_t syntax;
{
  reg_syntax_t ret = re_syntax_options;

  re_syntax_options = syntax;
#ifdef DEBUG
  if (syntax & RE_DEBUG)
    debug = 1;
  else if (debug) /* was on but now is not */
    debug = 0;
#endif /* DEBUG */
  return ret;
}
#ifdef _LIBC
weak_alias (__re_set_syntax, re_set_syntax)
#endif

/* This table gives an error message for each of the error codes listed
   in gnu-regex.h.  Obviously the order here has to be same as there.
   POSIX doesn't require that we do anything for REG_NOERROR,
   but why not be nice?  */

static const char *re_error_msgid[] =
  {
    gettext_noop ("Success"),	/* REG_NOERROR */
    gettext_noop ("No match"),	/* REG_NOMATCH */
    gettext_noop ("Invalid regular expression"), /* REG_BADPAT */
    gettext_noop ("Invalid collation character"), /* REG_ECOLLATE */
    gettext_noop ("Invalid character class name"), /* REG_ECTYPE */
    gettext_noop ("Trailing backslash"), /* REG_EESCAPE */
    gettext_noop ("Invalid back reference"), /* REG_ESUBREG */
    gettext_noop ("Unmatched [ or [^"),	/* REG_EBRACK */
    gettext_noop ("Unmatched ( or \\("), /* REG_EPAREN */
    gettext_noop ("Unmatched \\{"), /* REG_EBRACE */
    gettext_noop ("Invalid content of \\{\\}"), /* REG_BADBR */
    gettext_noop ("Invalid range end"),	/* REG_ERANGE */
    gettext_noop ("Memory exhausted"), /* REG_ESPACE */
    gettext_noop ("Invalid preceding regular expression"), /* REG_BADRPT */
    gettext_noop ("Premature end of regular expression"), /* REG_EEND */
    gettext_noop ("Regular expression too big"), /* REG_ESIZE */
    gettext_noop ("Unmatched ) or \\)"), /* REG_ERPAREN */
  };

/* Avoiding alloca during matching, to placate r_alloc.  */

/* Define MATCH_MAY_ALLOCATE unless we need to make sure that the
   searching and matching functions should not call alloca.  On some
   systems, alloca is implemented in terms of malloc, and if we're
   using the relocating allocator routines, then malloc could cause a
   relocation, which might (if the strings being searched are in the
   ralloc heap) shift the data out from underneath the regexp
   routines.

   Here's another reason to avoid allocation: Emacs
   processes input from X in a signal handler; processing X input may
   call malloc; if input arrives while a matching routine is calling
   malloc, then we're scrod.  But Emacs can't just block input while
   calling matching routines; then we don't notice interrupts when
   they come in.  So, Emacs blocks input around all regexp calls
   except the matching calls, which it leaves unprotected, in the
   faith that they will not malloc.  */

/* Normally, this is fine.  */
#define MATCH_MAY_ALLOCATE

/* When using GNU C, we are not REALLY using the C alloca, no matter
   what config.h may say.  So don't take precautions for it.  */
#ifdef __GNUC__
# undef C_ALLOCA
#endif

/* The match routines may not allocate if (1) they would do it with malloc
   and (2) it's not safe for them to use malloc.
   Note that if REL_ALLOC is defined, matching would not use malloc for the
   failure stack, but we would still use it for the register vectors;
   so REL_ALLOC should not affect this.  */
#if (defined C_ALLOCA || defined REGEX_MALLOC) && defined emacs
# undef MATCH_MAY_ALLOCATE
#endif


/* Failure stack declarations and macros; both re_compile_fastmap and
   re_match_2 use a failure stack.  These have to be macros because of
   REGEX_ALLOCATE_STACK.  */


/* Number of failure points for which to initially allocate space
   when matching.  If this number is exceeded, we allocate more
   space, so it is not a hard limit.  */
#ifndef INIT_FAILURE_ALLOC
# define INIT_FAILURE_ALLOC 5
#endif

/* Roughly the maximum number of failure points on the stack.  Would be
   exactly that if always used MAX_FAILURE_ITEMS items each time we failed.
   This is a variable only so users of regex can assign to it; we never
   change it ourselves.  */

#ifdef INT_IS_16BIT

# if defined MATCH_MAY_ALLOCATE
/* 4400 was enough to cause a crash on Alpha OSF/1,
   whose default stack limit is 2mb.  */
long int re_max_failures = 4000;
# else
long int re_max_failures = 2000;
# endif

union fail_stack_elt
{
  unsigned char *pointer;
  long int integer;
};

typedef union fail_stack_elt fail_stack_elt_t;

typedef struct
{
  fail_stack_elt_t *stack;
  unsigned long int size;
  unsigned long int avail;		/* Offset of next open position.  */
} fail_stack_type;

#else /* not INT_IS_16BIT */

# if defined MATCH_MAY_ALLOCATE
/* 4400 was enough to cause a crash on Alpha OSF/1,
   whose default stack limit is 2mb.  */
int re_max_failures = 20000;
# else
int re_max_failures = 2000;
# endif

union fail_stack_elt
{
  unsigned char *pointer;
  int integer;
};

typedef union fail_stack_elt fail_stack_elt_t;

typedef struct
{
  fail_stack_elt_t *stack;
  unsigned size;
  unsigned avail;			/* Offset of next open position.  */
} fail_stack_type;

#endif /* INT_IS_16BIT */

#define FAIL_STACK_EMPTY()     (fail_stack.avail == 0)
#define FAIL_STACK_PTR_EMPTY() (fail_stack_ptr->avail == 0)
#define FAIL_STACK_FULL()      (fail_stack.avail == fail_stack.size)


/* Define macros to initialize and free the failure stack.
   Do `return -2' if the alloc fails.  */

#ifdef MATCH_MAY_ALLOCATE
# define INIT_FAIL_STACK()						\
  do {									\
    fail_stack.stack = (fail_stack_elt_t *)				\
      REGEX_ALLOCATE_STACK (INIT_FAILURE_ALLOC * sizeof (fail_stack_elt_t)); \
									\
    if (fail_stack.stack == NULL)					\
      return -2;							\
									\
    fail_stack.size = INIT_FAILURE_ALLOC;				\
    fail_stack.avail = 0;						\
  } while (0)

# define RESET_FAIL_STACK()  REGEX_FREE_STACK (fail_stack.stack)
#else
# define INIT_FAIL_STACK()						\
  do {									\
    fail_stack.avail = 0;						\
  } while (0)

# define RESET_FAIL_STACK()
#endif


/* Double the size of FAIL_STACK, up to approximately `re_max_failures' items.

   Return 1 if succeeds, and 0 if either ran out of memory
   allocating space for it or it was already too large.

   REGEX_REALLOCATE_STACK requires `destination' be declared.   */

#define DOUBLE_FAIL_STACK(fail_stack)					\
  ((fail_stack).size > (unsigned) (re_max_failures * MAX_FAILURE_ITEMS)	\
   ? 0									\
   : ((fail_stack).stack = (fail_stack_elt_t *)				\
        REGEX_REALLOCATE_STACK ((fail_stack).stack, 			\
          (fail_stack).size * sizeof (fail_stack_elt_t),		\
          ((fail_stack).size << 1) * sizeof (fail_stack_elt_t)),	\
									\
      (fail_stack).stack == NULL					\
      ? 0								\
      : ((fail_stack).size <<= 1, 					\
         1)))


/* Push pointer POINTER on FAIL_STACK.
   Return 1 if was able to do so and 0 if ran out of memory allocating
   space to do so.  */
#define PUSH_PATTERN_OP(POINTER, FAIL_STACK)				\
  ((FAIL_STACK_FULL ()							\
    && !DOUBLE_FAIL_STACK (FAIL_STACK))					\
   ? 0									\
   : ((FAIL_STACK).stack[(FAIL_STACK).avail++].pointer = POINTER,	\
      1))

/* Push a pointer value onto the failure stack.
   Assumes the variable `fail_stack'.  Probably should only
   be called from within `PUSH_FAILURE_POINT'.  */
#define PUSH_FAILURE_POINTER(item)					\
  fail_stack.stack[fail_stack.avail++].pointer = (unsigned char *) (item)

/* This pushes an integer-valued item onto the failure stack.
   Assumes the variable `fail_stack'.  Probably should only
   be called from within `PUSH_FAILURE_POINT'.  */
#define PUSH_FAILURE_INT(item)					\
  fail_stack.stack[fail_stack.avail++].integer = (item)

/* Push a fail_stack_elt_t value onto the failure stack.
   Assumes the variable `fail_stack'.  Probably should only
   be called from within `PUSH_FAILURE_POINT'.  */
#define PUSH_FAILURE_ELT(item)					\
  fail_stack.stack[fail_stack.avail++] =  (item)

/* These three POP... operations complement the three PUSH... operations.
   All assume that `fail_stack' is nonempty.  */
#define POP_FAILURE_POINTER() fail_stack.stack[--fail_stack.avail].pointer
#define POP_FAILURE_INT() fail_stack.stack[--fail_stack.avail].integer
#define POP_FAILURE_ELT() fail_stack.stack[--fail_stack.avail]

/* Used to omit pushing failure point id's when we're not debugging.  */
#ifdef DEBUG
# define DEBUG_PUSH PUSH_FAILURE_INT
# define DEBUG_POP(item_addr) *(item_addr) = POP_FAILURE_INT ()
#else
# define DEBUG_PUSH(item)
# define DEBUG_POP(item_addr)
#endif


/* Push the information about the state we will need
   if we ever fail back to it.

   Requires variables fail_stack, regstart, regend, reg_info, and
   num_regs_pushed be declared.  DOUBLE_FAIL_STACK requires `destination'
   be declared.

   Does `return FAILURE_CODE' if runs out of memory.  */

#define PUSH_FAILURE_POINT(pattern_place, string_place, failure_code)	\
  do {									\
    char *destination;							\
    /* Must be int, so when we don't save any registers, the arithmetic	\
       of 0 + -1 isn't done as unsigned.  */				\
    /* Can't be int, since there is not a shred of a guarantee that int	\
       is wide enough to hold a value of something to which pointer can	\
       be assigned */							\
    active_reg_t this_reg;						\
    									\
    DEBUG_STATEMENT (failure_id++);					\
    DEBUG_STATEMENT (nfailure_points_pushed++);				\
    DEBUG_PRINT2 ("\nPUSH_FAILURE_POINT #%u:\n", failure_id);		\
    DEBUG_PRINT2 ("  Before push, next avail: %d\n", (fail_stack).avail);\
    DEBUG_PRINT2 ("                     size: %d\n", (fail_stack).size);\
									\
    DEBUG_PRINT2 ("  slots needed: %ld\n", NUM_FAILURE_ITEMS);		\
    DEBUG_PRINT2 ("     available: %d\n", REMAINING_AVAIL_SLOTS);	\
									\
    /* Ensure we have enough space allocated for what we will push.  */	\
    while (REMAINING_AVAIL_SLOTS < NUM_FAILURE_ITEMS)			\
      {									\
        if (!DOUBLE_FAIL_STACK (fail_stack))				\
          return failure_code;						\
									\
        DEBUG_PRINT2 ("\n  Doubled stack; size now: %d\n",		\
		       (fail_stack).size);				\
        DEBUG_PRINT2 ("  slots available: %d\n", REMAINING_AVAIL_SLOTS);\
      }									\
									\
    /* Push the info, starting with the registers.  */			\
    DEBUG_PRINT1 ("\n");						\
									\
    if (1)								\
      for (this_reg = lowest_active_reg; this_reg <= highest_active_reg; \
	   this_reg++)							\
	{								\
	  DEBUG_PRINT2 ("  Pushing reg: %lu\n", this_reg);		\
	  DEBUG_STATEMENT (num_regs_pushed++);				\
									\
	  DEBUG_PRINT2 ("    start: %p\n", regstart[this_reg]);		\
	  PUSH_FAILURE_POINTER (regstart[this_reg]);			\
									\
	  DEBUG_PRINT2 ("    end: %p\n", regend[this_reg]);		\
	  PUSH_FAILURE_POINTER (regend[this_reg]);			\
									\
	  DEBUG_PRINT2 ("    info: %p\n      ",				\
			reg_info[this_reg].word.pointer);		\
	  DEBUG_PRINT2 (" match_null=%d",				\
			REG_MATCH_NULL_STRING_P (reg_info[this_reg]));	\
	  DEBUG_PRINT2 (" active=%d", IS_ACTIVE (reg_info[this_reg]));	\
	  DEBUG_PRINT2 (" matched_something=%d",			\
			MATCHED_SOMETHING (reg_info[this_reg]));	\
	  DEBUG_PRINT2 (" ever_matched=%d",				\
			EVER_MATCHED_SOMETHING (reg_info[this_reg]));	\
	  DEBUG_PRINT1 ("\n");						\
	  PUSH_FAILURE_ELT (reg_info[this_reg].word);			\
	}								\
									\
    DEBUG_PRINT2 ("  Pushing  low active reg: %ld\n", lowest_active_reg);\
    PUSH_FAILURE_INT (lowest_active_reg);				\
									\
    DEBUG_PRINT2 ("  Pushing high active reg: %ld\n", highest_active_reg);\
    PUSH_FAILURE_INT (highest_active_reg);				\
									\
    DEBUG_PRINT2 ("  Pushing pattern %p:\n", pattern_place);		\
    DEBUG_PRINT_COMPILED_PATTERN (bufp, pattern_place, pend);		\
    PUSH_FAILURE_POINTER (pattern_place);				\
									\
    DEBUG_PRINT2 ("  Pushing string %p: `", string_place);		\
    DEBUG_PRINT_DOUBLE_STRING (string_place, string1, size1, string2,   \
				 size2);				\
    DEBUG_PRINT1 ("'\n");						\
    PUSH_FAILURE_POINTER (string_place);				\
									\
    DEBUG_PRINT2 ("  Pushing failure id: %u\n", failure_id);		\
    DEBUG_PUSH (failure_id);						\
  } while (0)

/* This is the number of items that are pushed and popped on the stack
   for each register.  */
#define NUM_REG_ITEMS  3

/* Individual items aside from the registers.  */
#ifdef DEBUG
# define NUM_NONREG_ITEMS 5 /* Includes failure point id.  */
#else
# define NUM_NONREG_ITEMS 4
#endif

/* We push at most this many items on the stack.  */
/* We used to use (num_regs - 1), which is the number of registers
   this regexp will save; but that was changed to 5
   to avoid stack overflow for a regexp with lots of parens.  */
#define MAX_FAILURE_ITEMS (5 * NUM_REG_ITEMS + NUM_NONREG_ITEMS)

/* We actually push this many items.  */
#define NUM_FAILURE_ITEMS				\
  (((0							\
     ? 0 : highest_active_reg - lowest_active_reg + 1)	\
    * NUM_REG_ITEMS)					\
   + NUM_NONREG_ITEMS)

/* How many items can still be added to the stack without overflowing it.  */
#define REMAINING_AVAIL_SLOTS ((fail_stack).size - (fail_stack).avail)


/* Pops what PUSH_FAIL_STACK pushes.

   We restore into the parameters, all of which should be lvalues:
     STR -- the saved data position.
     PAT -- the saved pattern position.
     LOW_REG, HIGH_REG -- the highest and lowest active registers.
     REGSTART, REGEND -- arrays of string positions.
     REG_INFO -- array of information about each subexpression.

   Also assumes the variables `fail_stack' and (if debugging), `bufp',
   `pend', `string1', `size1', `string2', and `size2'.  */

#define POP_FAILURE_POINT(str, pat, low_reg, high_reg, regstart, regend, reg_info)\
{									\
  DEBUG_STATEMENT (unsigned failure_id;)				\
  active_reg_t this_reg;						\
  const unsigned char *string_temp;					\
									\
  assert (!FAIL_STACK_EMPTY ());					\
									\
  /* Remove failure points and point to how many regs pushed.  */	\
  DEBUG_PRINT1 ("POP_FAILURE_POINT:\n");				\
  DEBUG_PRINT2 ("  Before pop, next avail: %d\n", fail_stack.avail);	\
  DEBUG_PRINT2 ("                    size: %d\n", fail_stack.size);	\
									\
  assert (fail_stack.avail >= NUM_NONREG_ITEMS);			\
									\
  DEBUG_POP (&failure_id);						\
  DEBUG_PRINT2 ("  Popping failure id: %u\n", failure_id);		\
									\
  /* If the saved string location is NULL, it came from an		\
     on_failure_keep_string_jump opcode, and we want to throw away the	\
     saved NULL, thus retaining our current position in the string.  */	\
  string_temp = POP_FAILURE_POINTER ();					\
  if (string_temp != NULL)						\
    str = (const char *) string_temp;					\
									\
  DEBUG_PRINT2 ("  Popping string %p: `", str);				\
  DEBUG_PRINT_DOUBLE_STRING (str, string1, size1, string2, size2);	\
  DEBUG_PRINT1 ("'\n");							\
									\
  pat = (unsigned char *) POP_FAILURE_POINTER ();			\
  DEBUG_PRINT2 ("  Popping pattern %p:\n", pat);			\
  DEBUG_PRINT_COMPILED_PATTERN (bufp, pat, pend);			\
									\
  /* Restore register info.  */						\
  high_reg = (active_reg_t) POP_FAILURE_INT ();				\
  DEBUG_PRINT2 ("  Popping high active reg: %ld\n", high_reg);		\
									\
  low_reg = (active_reg_t) POP_FAILURE_INT ();				\
  DEBUG_PRINT2 ("  Popping  low active reg: %ld\n", low_reg);		\
									\
  if (1)								\
    for (this_reg = high_reg; this_reg >= low_reg; this_reg--)		\
      {									\
	DEBUG_PRINT2 ("    Popping reg: %ld\n", this_reg);		\
									\
	reg_info[this_reg].word = POP_FAILURE_ELT ();			\
	DEBUG_PRINT2 ("      info: %p\n",				\
		      reg_info[this_reg].word.pointer);			\
									\
	regend[this_reg] = (const char *) POP_FAILURE_POINTER ();	\
	DEBUG_PRINT2 ("      end: %p\n", regend[this_reg]);		\
									\
	regstart[this_reg] = (const char *) POP_FAILURE_POINTER ();	\
	DEBUG_PRINT2 ("      start: %p\n", regstart[this_reg]);		\
      }									\
  else									\
    {									\
      for (this_reg = highest_active_reg; this_reg > high_reg; this_reg--) \
	{								\
	  reg_info[this_reg].word.integer = 0;				\
	  regend[this_reg] = 0;						\
	  regstart[this_reg] = 0;					\
	}								\
      highest_active_reg = high_reg;					\
    }									\
									\
  set_regs_matched_done = 0;						\
  DEBUG_STATEMENT (nfailure_points_popped++);				\
} /* POP_FAILURE_POINT */



/* Structure for per-register (a.k.a. per-group) information.
   Other register information, such as the
   starting and ending positions (which are addresses), and the list of
   inner groups (which is a bits list) are maintained in separate
   variables.

   We are making a (strictly speaking) nonportable assumption here: that
   the compiler will pack our bit fields into something that fits into
   the type of `word', i.e., is something that fits into one item on the
   failure stack.  */


/* Declarations and macros for re_match_2.  */

typedef union
{
  fail_stack_elt_t word;
  struct
  {
      /* This field is one if this group can match the empty string,
         zero if not.  If not yet determined,  `MATCH_NULL_UNSET_VALUE'.  */
#define MATCH_NULL_UNSET_VALUE 3
    unsigned match_null_string_p : 2;
    unsigned is_active : 1;
    unsigned matched_something : 1;
    unsigned ever_matched_something : 1;
  } bits;
} register_info_type;

#define REG_MATCH_NULL_STRING_P(R)  ((R).bits.match_null_string_p)
#define IS_ACTIVE(R)  ((R).bits.is_active)
#define MATCHED_SOMETHING(R)  ((R).bits.matched_something)
#define EVER_MATCHED_SOMETHING(R)  ((R).bits.ever_matched_something)


/* Call this when have matched a real character; it sets `matched' flags
   for the subexpressions which we are currently inside.  Also records
   that those subexprs have matched.  */
#define SET_REGS_MATCHED()						\
  do									\
    {									\
      if (!set_regs_matched_done)					\
	{								\
	  active_reg_t r;						\
	  set_regs_matched_done = 1;					\
	  for (r = lowest_active_reg; r <= highest_active_reg; r++)	\
	    {								\
	      MATCHED_SOMETHING (reg_info[r])				\
		= EVER_MATCHED_SOMETHING (reg_info[r])			\
		= 1;							\
	    }								\
	}								\
    }									\
  while (0)

/* Registers are set to a sentinel when they haven't yet matched.  */
static char reg_unset_dummy;
#define REG_UNSET_VALUE (&reg_unset_dummy)
#define REG_UNSET(e) ((e) == REG_UNSET_VALUE)

/* Subroutine declarations and macros for regex_compile.  */

static reg_errcode_t regex_compile _RE_ARGS ((const char *pattern, size_t size,
					      reg_syntax_t syntax,
					      struct re_pattern_buffer *bufp));
static void store_op1 _RE_ARGS ((re_opcode_t op, unsigned char *loc, int arg));
static void store_op2 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
				 int arg1, int arg2));
static void insert_op1 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
				  int arg, unsigned char *end));
static void insert_op2 _RE_ARGS ((re_opcode_t op, unsigned char *loc,
				  int arg1, int arg2, unsigned char *end));
static boolean at_begline_loc_p _RE_ARGS ((const char *pattern, const char *p,
					   reg_syntax_t syntax));
static boolean at_endline_loc_p _RE_ARGS ((const char *p, const char *pend,
					   reg_syntax_t syntax));
static reg_errcode_t compile_range _RE_ARGS ((const char **p_ptr,
					      const char *pend,
					      char *translate,
					      reg_syntax_t syntax,
					      unsigned char *b));

/* Fetch the next character in the uncompiled pattern---translating it
   if necessary.  Also cast from a signed character in the constant
   string passed to us by the user to an unsigned char that we can use
   as an array index (in, e.g., `translate').  */
#ifndef PATFETCH
# define PATFETCH(c)							\
  do {if (p == pend) return REG_EEND;					\
    c = (unsigned char) *p++;						\
    if (translate) c = (unsigned char) translate[c];			\
  } while (0)
#endif

/* Fetch the next character in the uncompiled pattern, with no
   translation.  */
#define PATFETCH_RAW(c)							\
  do {if (p == pend) return REG_EEND;					\
    c = (unsigned char) *p++; 						\
  } while (0)

/* Go backwards one character in the pattern.  */
#define PATUNFETCH p--


/* If `translate' is non-null, return translate[D], else just D.  We
   cast the subscript to translate because some data is declared as
   `char *', to avoid warnings when a string constant is passed.  But
   when we use a character as a subscript we must make it unsigned.  */
#ifndef TRANSLATE
# define TRANSLATE(d) \
  (translate ? (char) translate[(unsigned char) (d)] : (d))
#endif


/* Macros for outputting the compiled pattern into `buffer'.  */

/* If the buffer isn't allocated when it comes in, use this.  */
#define INIT_BUF_SIZE  32

/* Make sure we have at least N more bytes of space in buffer.  */
#define GET_BUFFER_SPACE(n)						\
    while ((unsigned long) (b - bufp->buffer + (n)) > bufp->allocated)	\
      EXTEND_BUFFER ()

/* Make sure we have one more byte of buffer space and then add C to it.  */
#define BUF_PUSH(c)							\
  do {									\
    GET_BUFFER_SPACE (1);						\
    *b++ = (unsigned char) (c);						\
  } while (0)


/* Ensure we have two more bytes of buffer space and then append C1 and C2.  */
#define BUF_PUSH_2(c1, c2)						\
  do {									\
    GET_BUFFER_SPACE (2);						\
    *b++ = (unsigned char) (c1);					\
    *b++ = (unsigned char) (c2);					\
  } while (0)


/* As with BUF_PUSH_2, except for three bytes.  */
#define BUF_PUSH_3(c1, c2, c3)						\
  do {									\
    GET_BUFFER_SPACE (3);						\
    *b++ = (unsigned char) (c1);					\
    *b++ = (unsigned char) (c2);					\
    *b++ = (unsigned char) (c3);					\
  } while (0)


/* Store a jump with opcode OP at LOC to location TO.  We store a
   relative address offset by the three bytes the jump itself occupies.  */
#define STORE_JUMP(op, loc, to) \
  store_op1 (op, loc, (int) ((to) - (loc) - 3))

/* Likewise, for a two-argument jump.  */
#define STORE_JUMP2(op, loc, to, arg) \
  store_op2 (op, loc, (int) ((to) - (loc) - 3), arg)

/* Like `STORE_JUMP', but for inserting.  Assume `b' is the buffer end.  */
#define INSERT_JUMP(op, loc, to) \
  insert_op1 (op, loc, (int) ((to) - (loc) - 3), b)

/* Like `STORE_JUMP2', but for inserting.  Assume `b' is the buffer end.  */
#define INSERT_JUMP2(op, loc, to, arg) \
  insert_op2 (op, loc, (int) ((to) - (loc) - 3), arg, b)


/* This is not an arbitrary limit: the arguments which represent offsets
   into the pattern are two bytes long.  So if 2^16 bytes turns out to
   be too small, many things would have to change.  */
/* Any other compiler which, like MSC, has allocation limit below 2^16
   bytes will have to use approach similar to what was done below for
   MSC and drop MAX_BUF_SIZE a bit.  Otherwise you may end up
   reallocating to 0 bytes.  Such thing is not going to work too well.
   You have been warned!!  */
#if defined _MSC_VER  && !defined WIN32
/* Microsoft C 16-bit versions limit malloc to approx 65512 bytes.
   The REALLOC define eliminates a flurry of conversion warnings,
   but is not required. */
# define MAX_BUF_SIZE  65500L
# define REALLOC(p,s) realloc ((p), (size_t) (s))
#else
# define MAX_BUF_SIZE (1L << 16)
# define REALLOC(p,s) realloc ((p), (s))
#endif

/* Extend the buffer by twice its current size via realloc and
   reset the pointers that pointed into the old block to point to the
   correct places in the new one.  If extending the buffer results in it
   being larger than MAX_BUF_SIZE, then flag memory exhausted.  */
#define EXTEND_BUFFER()							\
  do { 									\
    unsigned char *old_buffer = bufp->buffer;				\
    if (bufp->allocated == MAX_BUF_SIZE) 				\
      return REG_ESIZE;							\
    bufp->allocated <<= 1;						\
    if (bufp->allocated > MAX_BUF_SIZE)					\
      bufp->allocated = MAX_BUF_SIZE; 					\
    bufp->buffer = (unsigned char *) REALLOC (bufp->buffer, bufp->allocated);\
    if (bufp->buffer == NULL)						\
      return REG_ESPACE;						\
    /* If the buffer moved, move all the pointers into it.  */		\
    if (old_buffer != bufp->buffer)					\
      {									\
        b = (b - old_buffer) + bufp->buffer;				\
        begalt = (begalt - old_buffer) + bufp->buffer;			\
        if (fixup_alt_jump)						\
          fixup_alt_jump = (fixup_alt_jump - old_buffer) + bufp->buffer;\
        if (laststart)							\
          laststart = (laststart - old_buffer) + bufp->buffer;		\
        if (pending_exact)						\
          pending_exact = (pending_exact - old_buffer) + bufp->buffer;	\
      }									\
  } while (0)


/* Since we have one byte reserved for the register number argument to
   {start,stop}_memory, the maximum number of groups we can report
   things about is what fits in that byte.  */
#define MAX_REGNUM 255

/* But patterns can have more than `MAX_REGNUM' registers.  We just
   ignore the excess.  */
typedef unsigned regnum_t;


/* Macros for the compile stack.  */

/* Since offsets can go either forwards or backwards, this type needs to
   be able to hold values from -(MAX_BUF_SIZE - 1) to MAX_BUF_SIZE - 1.  */
/* int may be not enough when sizeof(int) == 2.  */
typedef long pattern_offset_t;

typedef struct
{
  pattern_offset_t begalt_offset;
  pattern_offset_t fixup_alt_jump;
  pattern_offset_t inner_group_offset;
  pattern_offset_t laststart_offset;
  regnum_t regnum;
} compile_stack_elt_t;


typedef struct
{
  compile_stack_elt_t *stack;
  unsigned size;
  unsigned avail;			/* Offset of next open position.  */
} compile_stack_type;


#define INIT_COMPILE_STACK_SIZE 32

#define COMPILE_STACK_EMPTY  (compile_stack.avail == 0)
#define COMPILE_STACK_FULL  (compile_stack.avail == compile_stack.size)

/* The next available element.  */
#define COMPILE_STACK_TOP (compile_stack.stack[compile_stack.avail])


/* Set the bit for character C in a list.  */
#define SET_LIST_BIT(c)                               \
  (b[((unsigned char) (c)) / BYTEWIDTH]               \
   |= 1 << (((unsigned char) c) % BYTEWIDTH))


/* Get the next unsigned number in the uncompiled pattern.  */
#define GET_UNSIGNED_NUMBER(num) 					\
  { if (p != pend)							\
     {									\
       PATFETCH (c); 							\
       while (ISDIGIT (c)) 						\
         { 								\
           if (num < 0)							\
              num = 0;							\
           num = num * 10 + c - '0'; 					\
           if (p == pend) 						\
              break; 							\
           PATFETCH (c);						\
         } 								\
       } 								\
    }

/* Use this only if they have btowc(), since wctype() is used below
   together with btowc().  btowc() is defined in the 1994 Amendment 1
   to ISO C and may not be present on systems where we have wchar.h
   and wctype.h.  */
#if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H && defined HAVE_BTOWC)
/* The GNU C library provides support for user-defined character classes
   and the functions from ISO C amendement 1.  */
# ifdef CHARCLASS_NAME_MAX
#  define CHAR_CLASS_MAX_LENGTH CHARCLASS_NAME_MAX
# else
/* This shouldn't happen but some implementation might still have this
   problem.  Use a reasonable default value.  */
#  define CHAR_CLASS_MAX_LENGTH 256
# endif

# ifdef _LIBC
#  define IS_CHAR_CLASS(string) __wctype (string)
# else
#  define IS_CHAR_CLASS(string) wctype (string)
# endif
#else
# define CHAR_CLASS_MAX_LENGTH  6 /* Namely, `xdigit'.  */

# define IS_CHAR_CLASS(string)						\
   (STREQ (string, "alpha") || STREQ (string, "upper")			\
    || STREQ (string, "lower") || STREQ (string, "digit")		\
    || STREQ (string, "alnum") || STREQ (string, "xdigit")		\
    || STREQ (string, "space") || STREQ (string, "print")		\
    || STREQ (string, "punct") || STREQ (string, "graph")		\
    || STREQ (string, "cntrl") || STREQ (string, "blank"))
#endif

#ifndef MATCH_MAY_ALLOCATE

/* If we cannot allocate large objects within re_match_2_internal,
   we make the fail stack and register vectors global.
   The fail stack, we grow to the maximum size when a regexp
   is compiled.
   The register vectors, we adjust in size each time we
   compile a regexp, according to the number of registers it needs.  */

static fail_stack_type fail_stack;

/* Size with which the following vectors are currently allocated.
   That is so we can make them bigger as needed,
   but never make them smaller.  */
static int regs_allocated_size;

static const char **     regstart, **     regend;
static const char ** old_regstart, ** old_regend;
static const char **best_regstart, **best_regend;
static register_info_type *reg_info;
static const char **reg_dummy;
static register_info_type *reg_info_dummy;

/* Make the register vectors big enough for NUM_REGS registers,
   but don't make them smaller.  */

static
regex_grow_registers (num_regs)
     int num_regs;
{
  if (num_regs > regs_allocated_size)
    {
      RETALLOC_IF (regstart,	 num_regs, const char *);
      RETALLOC_IF (regend,	 num_regs, const char *);
      RETALLOC_IF (old_regstart, num_regs, const char *);
      RETALLOC_IF (old_regend,	 num_regs, const char *);
      RETALLOC_IF (best_regstart, num_regs, const char *);
      RETALLOC_IF (best_regend,	 num_regs, const char *);
      RETALLOC_IF (reg_info,	 num_regs, register_info_type);
      RETALLOC_IF (reg_dummy,	 num_regs, const char *);
      RETALLOC_IF (reg_info_dummy, num_regs, register_info_type);

      regs_allocated_size = num_regs;
    }
}

#endif /* not MATCH_MAY_ALLOCATE */

static boolean group_in_compile_stack _RE_ARGS ((compile_stack_type
						 compile_stack,
						 regnum_t regnum));

/* `regex_compile' compiles PATTERN (of length SIZE) according to SYNTAX.
   Returns one of error codes defined in `gnu-regex.h', or zero for success.

   Assumes the `allocated' (and perhaps `buffer') and `translate'
   fields are set in BUFP on entry.

   If it succeeds, results are put in BUFP (if it returns an error, the
   contents of BUFP are undefined):
     `buffer' is the compiled pattern;
     `syntax' is set to SYNTAX;
     `used' is set to the length of the compiled pattern;
     `fastmap_accurate' is zero;
     `re_nsub' is the number of subexpressions in PATTERN;
     `not_bol' and `not_eol' are zero;

   The `fastmap' and `newline_anchor' fields are neither
   examined nor set.  */

/* Return, freeing storage we allocated.  */
#define FREE_STACK_RETURN(value)		\
  return (free (compile_stack.stack), value)

static reg_errcode_t
regex_compile (pattern, size, syntax, bufp)
     const char *pattern;
     size_t size;
     reg_syntax_t syntax;
     struct re_pattern_buffer *bufp;
{
  /* We fetch characters from PATTERN here.  Even though PATTERN is
     `char *' (i.e., signed), we declare these variables as unsigned, so
     they can be reliably used as array indices.  */
  register unsigned char c, c1;

  /* A random temporary spot in PATTERN.  */
  const char *p1;

  /* Points to the end of the buffer, where we should append.  */
  register unsigned char *b;

  /* Keeps track of unclosed groups.  */
  compile_stack_type compile_stack;

  /* Points to the current (ending) position in the pattern.  */
  const char *p = pattern;
  const char *pend = pattern + size;

  /* How to translate the characters in the pattern.  */
  RE_TRANSLATE_TYPE translate = bufp->translate;

  /* Address of the count-byte of the most recently inserted `exactn'
     command.  This makes it possible to tell if a new exact-match
     character can be added to that command or if the character requires
     a new `exactn' command.  */
  unsigned char *pending_exact = 0;

  /* Address of start of the most recently finished expression.
     This tells, e.g., postfix * where to find the start of its
     operand.  Reset at the beginning of groups and alternatives.  */
  unsigned char *laststart = 0;

  /* Address of beginning of regexp, or inside of last group.  */
  unsigned char *begalt;

  /* Place in the uncompiled pattern (i.e., the {) to
     which to go back if the interval is invalid.  */
  const char *beg_interval;

  /* Address of the place where a forward jump should go to the end of
     the containing expression.  Each alternative of an `or' -- except the
     last -- ends with a forward jump of this sort.  */
  unsigned char *fixup_alt_jump = 0;

  /* Counts open-groups as they are encountered.  Remembered for the
     matching close-group on the compile stack, so the same register
     number is put in the stop_memory as the start_memory.  */
  regnum_t regnum = 0;

#ifdef DEBUG
  DEBUG_PRINT1 ("\nCompiling pattern: ");
  if (debug)
    {
      unsigned debug_count;

      for (debug_count = 0; debug_count < size; debug_count++)
        putchar (pattern[debug_count]);
      putchar ('\n');
    }
#endif /* DEBUG */

  /* Initialize the compile stack.  */
  compile_stack.stack = TALLOC (INIT_COMPILE_STACK_SIZE, compile_stack_elt_t);
  if (compile_stack.stack == NULL)
    return REG_ESPACE;

  compile_stack.size = INIT_COMPILE_STACK_SIZE;
  compile_stack.avail = 0;

  /* Initialize the pattern buffer.  */
  bufp->syntax = syntax;
  bufp->fastmap_accurate = 0;
  bufp->not_bol = bufp->not_eol = 0;

  /* Set `used' to zero, so that if we return an error, the pattern
     printer (for debugging) will think there's no pattern.  We reset it
     at the end.  */
  bufp->used = 0;

  /* Always count groups, whether or not bufp->no_sub is set.  */
  bufp->re_nsub = 0;

#if !defined emacs && !defined SYNTAX_TABLE
  /* Initialize the syntax table.  */
   init_syntax_once ();
#endif

  if (bufp->allocated == 0)
    {
      if (bufp->buffer)
	{ /* If zero allocated, but buffer is non-null, try to realloc
             enough space.  This loses if buffer's address is bogus, but
             that is the user's responsibility.  */
          RETALLOC (bufp->buffer, INIT_BUF_SIZE, unsigned char);
        }
      else
        { /* Caller did not allocate a buffer.  Do it for them.  */
          bufp->buffer = TALLOC (INIT_BUF_SIZE, unsigned char);
        }
      if (!bufp->buffer) FREE_STACK_RETURN (REG_ESPACE);

      bufp->allocated = INIT_BUF_SIZE;
    }

  begalt = b = bufp->buffer;

  /* Loop through the uncompiled pattern until we're at the end.  */
  while (p != pend)
    {
      PATFETCH (c);

      switch (c)
        {
        case '^':
          {
            if (   /* If at start of pattern, it's an operator.  */
                   p == pattern + 1
                   /* If context independent, it's an operator.  */
                || syntax & RE_CONTEXT_INDEP_ANCHORS
                   /* Otherwise, depends on what's come before.  */
                || at_begline_loc_p (pattern, p, syntax))
              BUF_PUSH (begline);
            else
              goto normal_char;
          }
          break;


        case '$':
          {
            if (   /* If at end of pattern, it's an operator.  */
                   p == pend
                   /* If context independent, it's an operator.  */
                || syntax & RE_CONTEXT_INDEP_ANCHORS
                   /* Otherwise, depends on what's next.  */
                || at_endline_loc_p (p, pend, syntax))
               BUF_PUSH (endline);
             else
               goto normal_char;
           }
           break;


	case '+':
        case '?':
          if ((syntax & RE_BK_PLUS_QM)
              || (syntax & RE_LIMITED_OPS))
            goto normal_char;
        handle_plus:
        case '*':
          /* If there is no previous pattern... */
          if (!laststart)
            {
              if (syntax & RE_CONTEXT_INVALID_OPS)
                FREE_STACK_RETURN (REG_BADRPT);
              else if (!(syntax & RE_CONTEXT_INDEP_OPS))
                goto normal_char;
            }

          {
            /* Are we optimizing this jump?  */
            boolean keep_string_p = false;

            /* 1 means zero (many) matches is allowed.  */
            char zero_times_ok = 0, many_times_ok = 0;

            /* If there is a sequence of repetition chars, collapse it
               down to just one (the right one).  We can't combine
               interval operators with these because of, e.g., `a{2}*',
               which should only match an even number of `a's.  */

            for (;;)
              {
                zero_times_ok |= c != '+';
                many_times_ok |= c != '?';

                if (p == pend)
                  break;

                PATFETCH (c);

                if (c == '*'
                    || (!(syntax & RE_BK_PLUS_QM) && (c == '+' || c == '?')))
                  ;

                else if (syntax & RE_BK_PLUS_QM  &&  c == '\\')
                  {
                    if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);

                    PATFETCH (c1);
                    if (!(c1 == '+' || c1 == '?'))
                      {
                        PATUNFETCH;
                        PATUNFETCH;
                        break;
                      }

                    c = c1;
                  }
                else
                  {
                    PATUNFETCH;
                    break;
                  }

                /* If we get here, we found another repeat character.  */
               }

            /* Star, etc. applied to an empty pattern is equivalent
               to an empty pattern.  */
            if (!laststart)
              break;

            /* Now we know whether or not zero matches is allowed
               and also whether or not two or more matches is allowed.  */
            if (many_times_ok)
              { /* More than one repetition is allowed, so put in at the
                   end a backward relative jump from `b' to before the next
                   jump we're going to put in below (which jumps from
                   laststart to after this jump).

                   But if we are at the `*' in the exact sequence `.*\n',
                   insert an unconditional jump backwards to the .,
                   instead of the beginning of the loop.  This way we only
                   push a failure point once, instead of every time
                   through the loop.  */
                assert (p - 1 > pattern);

                /* Allocate the space for the jump.  */
                GET_BUFFER_SPACE (3);

                /* We know we are not at the first character of the pattern,
                   because laststart was nonzero.  And we've already
                   incremented `p', by the way, to be the character after
                   the `*'.  Do we have to do something analogous here
                   for null bytes, because of RE_DOT_NOT_NULL?  */
                if (TRANSLATE (*(p - 2)) == TRANSLATE ('.')
		    && zero_times_ok
                    && p < pend && TRANSLATE (*p) == TRANSLATE ('\n')
                    && !(syntax & RE_DOT_NEWLINE))
                  { /* We have .*\n.  */
                    STORE_JUMP (jump, b, laststart);
                    keep_string_p = true;
                  }
                else
                  /* Anything else.  */
                  STORE_JUMP (maybe_pop_jump, b, laststart - 3);

                /* We've added more stuff to the buffer.  */
                b += 3;
              }

            /* On failure, jump from laststart to b + 3, which will be the
               end of the buffer after this jump is inserted.  */
            GET_BUFFER_SPACE (3);
            INSERT_JUMP (keep_string_p ? on_failure_keep_string_jump
                                       : on_failure_jump,
                         laststart, b + 3);
            pending_exact = 0;
            b += 3;

            if (!zero_times_ok)
              {
                /* At least one repetition is required, so insert a
                   `dummy_failure_jump' before the initial
                   `on_failure_jump' instruction of the loop. This
                   effects a skip over that instruction the first time
                   we hit that loop.  */
                GET_BUFFER_SPACE (3);
                INSERT_JUMP (dummy_failure_jump, laststart, laststart + 6);
                b += 3;
              }
            }
	  break;


	case '.':
          laststart = b;
          BUF_PUSH (anychar);
          break;


        case '[':
          {
            boolean had_char_class = false;

            if (p == pend) FREE_STACK_RETURN (REG_EBRACK);

            /* Ensure that we have enough space to push a charset: the
               opcode, the length count, and the bitset; 34 bytes in all.  */
	    GET_BUFFER_SPACE (34);

            laststart = b;

            /* We test `*p == '^' twice, instead of using an if
               statement, so we only need one BUF_PUSH.  */
            BUF_PUSH (*p == '^' ? charset_not : charset);
            if (*p == '^')
              p++;

            /* Remember the first position in the bracket expression.  */
            p1 = p;

            /* Push the number of bytes in the bitmap.  */
            BUF_PUSH ((1 << BYTEWIDTH) / BYTEWIDTH);

            /* Clear the whole map.  */
            bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH);

            /* charset_not matches newline according to a syntax bit.  */
            if ((re_opcode_t) b[-2] == charset_not
                && (syntax & RE_HAT_LISTS_NOT_NEWLINE))
              SET_LIST_BIT ('\n');

            /* Read in characters and ranges, setting map bits.  */
            for (;;)
              {
                if (p == pend) FREE_STACK_RETURN (REG_EBRACK);

                PATFETCH (c);

                /* \ might escape characters inside [...] and [^...].  */
                if ((syntax & RE_BACKSLASH_ESCAPE_IN_LISTS) && c == '\\')
                  {
                    if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);

                    PATFETCH (c1);
                    SET_LIST_BIT (c1);
                    continue;
                  }

                /* Could be the end of the bracket expression.  If it's
                   not (i.e., when the bracket expression is `[]' so
                   far), the ']' character bit gets set way below.  */
                if (c == ']' && p != p1 + 1)
                  break;

                /* Look ahead to see if it's a range when the last thing
                   was a character class.  */
                if (had_char_class && c == '-' && *p != ']')
                  FREE_STACK_RETURN (REG_ERANGE);

                /* Look ahead to see if it's a range when the last thing
                   was a character: if this is a hyphen not at the
                   beginning or the end of a list, then it's the range
                   operator.  */
                if (c == '-'
                    && !(p - 2 >= pattern && p[-2] == '[')
                    && !(p - 3 >= pattern && p[-3] == '[' && p[-2] == '^')
                    && *p != ']')
                  {
                    reg_errcode_t ret
                      = compile_range (&p, pend, translate, syntax, b);
                    if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
                  }

                else if (p[0] == '-' && p[1] != ']')
                  { /* This handles ranges made up of characters only.  */
                    reg_errcode_t ret;

		    /* Move past the `-'.  */
                    PATFETCH (c1);

                    ret = compile_range (&p, pend, translate, syntax, b);
                    if (ret != REG_NOERROR) FREE_STACK_RETURN (ret);
                  }

                /* See if we're at the beginning of a possible character
                   class.  */

                else if (syntax & RE_CHAR_CLASSES && c == '[' && *p == ':')
                  { /* Leave room for the null.  */
                    char str[CHAR_CLASS_MAX_LENGTH + 1];

                    PATFETCH (c);
                    c1 = 0;

                    /* If pattern is `[[:'.  */
                    if (p == pend) FREE_STACK_RETURN (REG_EBRACK);

                    for (;;)
                      {
                        PATFETCH (c);
                        if ((c == ':' && *p == ']') || p == pend
                            || c1 == CHAR_CLASS_MAX_LENGTH)
                          break;
                        str[c1++] = c;
                      }
                    str[c1] = '\0';

                    /* If isn't a word bracketed by `[:' and `:]':
                       undo the ending character, the letters, and leave
                       the leading `:' and `[' (but set bits for them).  */
                    if (c == ':' && *p == ']')
                      {
/* CYGNUS LOCAL: Skip this code if we don't have btowc().  btowc() is */
/* defined in the 1994 Amendment 1 to ISO C and may not be present on */
/* systems where we have wchar.h and wctype.h.   */
#if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H && defined HAVE_BTOWC)
                        boolean is_lower = STREQ (str, "lower");
                        boolean is_upper = STREQ (str, "upper");
			wctype_t wt;
                        int ch;

			wt = IS_CHAR_CLASS (str);
			if (wt == 0)
			  FREE_STACK_RETURN (REG_ECTYPE);

                        /* Throw away the ] at the end of the character
                           class.  */
                        PATFETCH (c);

                        if (p == pend) FREE_STACK_RETURN (REG_EBRACK);

                        for (ch = 0; ch < 1 << BYTEWIDTH; ++ch)
			  {
# ifdef _LIBC
			    if (__iswctype (__btowc (ch), wt))
			      SET_LIST_BIT (ch);
#else
			    if (iswctype (btowc (ch), wt))
			      SET_LIST_BIT (ch);
#endif

			    if (translate && (is_upper || is_lower)
				&& (ISUPPER (ch) || ISLOWER (ch)))
			      SET_LIST_BIT (ch);
			  }

                        had_char_class = true;
#else
                        int ch;
                        boolean is_alnum = STREQ (str, "alnum");
                        boolean is_alpha = STREQ (str, "alpha");
                        boolean is_blank = STREQ (str, "blank");
                        boolean is_cntrl = STREQ (str, "cntrl");
                        boolean is_digit = STREQ (str, "digit");
                        boolean is_graph = STREQ (str, "graph");
                        boolean is_lower = STREQ (str, "lower");
                        boolean is_print = STREQ (str, "print");
                        boolean is_punct = STREQ (str, "punct");
                        boolean is_space = STREQ (str, "space");
                        boolean is_upper = STREQ (str, "upper");
                        boolean is_xdigit = STREQ (str, "xdigit");

                        if (!IS_CHAR_CLASS (str))
			  FREE_STACK_RETURN (REG_ECTYPE);

                        /* Throw away the ] at the end of the character
                           class.  */
                        PATFETCH (c);

                        if (p == pend) FREE_STACK_RETURN (REG_EBRACK);

                        for (ch = 0; ch < 1 << BYTEWIDTH; ch++)
                          {
			    /* This was split into 3 if's to
			       avoid an arbitrary limit in some compiler.  */
                            if (   (is_alnum  && ISALNUM (ch))
                                || (is_alpha  && ISALPHA (ch))
                                || (is_blank  && ISBLANK (ch))
                                || (is_cntrl  && ISCNTRL (ch)))
			      SET_LIST_BIT (ch);
			    if (   (is_digit  && ISDIGIT (ch))
                                || (is_graph  && ISGRAPH (ch))
                                || (is_lower  && ISLOWER (ch))
                                || (is_print  && ISPRINT (ch)))
			      SET_LIST_BIT (ch);
			    if (   (is_punct  && ISPUNCT (ch))
                                || (is_space  && ISSPACE (ch))
                                || (is_upper  && ISUPPER (ch))
                                || (is_xdigit && ISXDIGIT (ch)))
			      SET_LIST_BIT (ch);
			    if (   translate && (is_upper || is_lower)
				&& (ISUPPER (ch) || ISLOWER (ch)))
			      SET_LIST_BIT (ch);
                          }
                        had_char_class = true;
#endif	/* libc || wctype.h */
                      }
                    else
                      {
                        c1++;
                        while (c1--)
                          PATUNFETCH;
                        SET_LIST_BIT ('[');
                        SET_LIST_BIT (':');
                        had_char_class = false;
                      }
                  }
                else
                  {
                    had_char_class = false;
                    SET_LIST_BIT (c);
                  }
              }

            /* Discard any (non)matching list bytes that are all 0 at the
               end of the map.  Decrease the map-length byte too.  */
            while ((int) b[-1] > 0 && b[b[-1] - 1] == 0)
              b[-1]--;
            b += b[-1];
          }
          break;


	case '(':
          if (syntax & RE_NO_BK_PARENS)
            goto handle_open;
          else
            goto normal_char;


        case ')':
          if (syntax & RE_NO_BK_PARENS)
            goto handle_close;
          else
            goto normal_char;


        case '\n':
          if (syntax & RE_NEWLINE_ALT)
            goto handle_alt;
          else
            goto normal_char;


	case '|':
          if (syntax & RE_NO_BK_VBAR)
            goto handle_alt;
          else
            goto normal_char;


        case '{':
           if (syntax & RE_INTERVALS && syntax & RE_NO_BK_BRACES)
             goto handle_interval;
           else
             goto normal_char;


        case '\\':
          if (p == pend) FREE_STACK_RETURN (REG_EESCAPE);

          /* Do not translate the character after the \, so that we can
             distinguish, e.g., \B from \b, even if we normally would
             translate, e.g., B to b.  */
          PATFETCH_RAW (c);

          switch (c)
            {
            case '(':
              if (syntax & RE_NO_BK_PARENS)
                goto normal_backslash;

            handle_open:
              bufp->re_nsub++;
              regnum++;

              if (COMPILE_STACK_FULL)
                {
                  RETALLOC (compile_stack.stack, compile_stack.size << 1,
                            compile_stack_elt_t);
                  if (compile_stack.stack == NULL) return REG_ESPACE;

                  compile_stack.size <<= 1;
                }

              /* These are the values to restore when we hit end of this
                 group.  They are all relative offsets, so that if the
                 whole pattern moves because of realloc, they will still
                 be valid.  */
              COMPILE_STACK_TOP.begalt_offset = begalt - bufp->buffer;
              COMPILE_STACK_TOP.fixup_alt_jump
                = fixup_alt_jump ? fixup_alt_jump - bufp->buffer + 1 : 0;
              COMPILE_STACK_TOP.laststart_offset = b - bufp->buffer;
              COMPILE_STACK_TOP.regnum = regnum;

              /* We will eventually replace the 0 with the number of
                 groups inner to this one.  But do not push a
                 start_memory for groups beyond the last one we can
                 represent in the compiled pattern.  */
              if (regnum <= MAX_REGNUM)
                {
                  COMPILE_STACK_TOP.inner_group_offset = b - bufp->buffer + 2;
                  BUF_PUSH_3 (start_memory, regnum, 0);
                }

              compile_stack.avail++;

              fixup_alt_jump = 0;
              laststart = 0;
              begalt = b;
	      /* If we've reached MAX_REGNUM groups, then this open
		 won't actually generate any code, so we'll have to
		 clear pending_exact explicitly.  */
	      pending_exact = 0;
              break;


            case ')':
              if (syntax & RE_NO_BK_PARENS) goto normal_backslash;

              if (COMPILE_STACK_EMPTY)
		{
		  if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
		    goto normal_backslash;
		  else
		    FREE_STACK_RETURN (REG_ERPAREN);
		}

            handle_close:
              if (fixup_alt_jump)
                { /* Push a dummy failure point at the end of the
                     alternative for a possible future
                     `pop_failure_jump' to pop.  See comments at
                     `push_dummy_failure' in `re_match_2'.  */
                  BUF_PUSH (push_dummy_failure);

                  /* We allocated space for this jump when we assigned
                     to `fixup_alt_jump', in the `handle_alt' case below.  */
                  STORE_JUMP (jump_past_alt, fixup_alt_jump, b - 1);
                }

              /* See similar code for backslashed left paren above.  */
              if (COMPILE_STACK_EMPTY)
		{
		  if (syntax & RE_UNMATCHED_RIGHT_PAREN_ORD)
		    goto normal_char;
		  else
		    FREE_STACK_RETURN (REG_ERPAREN);
		}

              /* Since we just checked for an empty stack above, this
                 ``can't happen''.  */
              assert (compile_stack.avail != 0);
              {
                /* We don't just want to restore into `regnum', because
                   later groups should continue to be numbered higher,
                   as in `(ab)c(de)' -- the second group is #2.  */
                regnum_t this_group_regnum;

                compile_stack.avail--;
                begalt = bufp->buffer + COMPILE_STACK_TOP.begalt_offset;
                fixup_alt_jump
                  = COMPILE_STACK_TOP.fixup_alt_jump
                    ? bufp->buffer + COMPILE_STACK_TOP.fixup_alt_jump - 1
                    : 0;
                laststart = bufp->buffer + COMPILE_STACK_TOP.laststart_offset;
                this_group_regnum = COMPILE_STACK_TOP.regnum;
		/* If we've reached MAX_REGNUM groups, then this open
		   won't actually generate any code, so we'll have to
		   clear pending_exact explicitly.  */
		pending_exact = 0;

                /* We're at the end of the group, so now we know how many
                   groups were inside this one.  */
                if (this_group_regnum <= MAX_REGNUM)
                  {
                    unsigned char *inner_group_loc
                      = bufp->buffer + COMPILE_STACK_TOP.inner_group_offset;

                    *inner_group_loc = regnum - this_group_regnum;
                    BUF_PUSH_3 (stop_memory, this_group_regnum,
                                regnum - this_group_regnum);
                  }
              }
              break;


            case '|':					/* `\|'.  */
              if (syntax & RE_LIMITED_OPS || syntax & RE_NO_BK_VBAR)
                goto normal_backslash;
            handle_alt:
              if (syntax & RE_LIMITED_OPS)
                goto normal_char;

              /* Insert before the previous alternative a jump which
                 jumps to this alternative if the former fails.  */
              GET_BUFFER_SPACE (3);
              INSERT_JUMP (on_failure_jump, begalt, b + 6);
              pending_exact = 0;
              b += 3;

              /* The alternative before this one has a jump after it
                 which gets executed if it gets matched.  Adjust that
                 jump so it will jump to this alternative's analogous
                 jump (put in below, which in turn will jump to the next
                 (if any) alternative's such jump, etc.).  The last such
                 jump jumps to the correct final destination.  A picture:
                          _____ _____
                          |   | |   |
                          |   v |   v
                         a | b   | c

                 If we are at `b', then fixup_alt_jump right now points to a
                 three-byte space after `a'.  We'll put in the jump, set
                 fixup_alt_jump to right after `b', and leave behind three
                 bytes which we'll fill in when we get to after `c'.  */

              if (fixup_alt_jump)
                STORE_JUMP (jump_past_alt, fixup_alt_jump, b);

              /* Mark and leave space for a jump after this alternative,
                 to be filled in later either by next alternative or
                 when know we're at the end of a series of alternatives.  */
              fixup_alt_jump = b;
              GET_BUFFER_SPACE (3);
              b += 3;

              laststart = 0;
              begalt = b;
              break;


            case '{':
              /* If \{ is a literal.  */
              if (!(syntax & RE_INTERVALS)
                     /* If we're at `\{' and it's not the open-interval
                        operator.  */
                  || ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
                  || (p - 2 == pattern  &&  p == pend))
                goto normal_backslash;

            handle_interval:
              {
                /* If got here, then the syntax allows intervals.  */

                /* At least (most) this many matches must be made.  */
                int lower_bound = -1, upper_bound = -1;

                beg_interval = p - 1;

                if (p == pend)
                  {
                    if (syntax & RE_NO_BK_BRACES)
                      goto unfetch_interval;
                    else
                      FREE_STACK_RETURN (REG_EBRACE);
                  }

                GET_UNSIGNED_NUMBER (lower_bound);

                if (c == ',')
                  {
                    GET_UNSIGNED_NUMBER (upper_bound);
                    if (upper_bound < 0) upper_bound = RE_DUP_MAX;
                  }
                else
                  /* Interval such as `{1}' => match exactly once. */
                  upper_bound = lower_bound;

                if (lower_bound < 0 || upper_bound > RE_DUP_MAX
                    || lower_bound > upper_bound)
                  {
                    if (syntax & RE_NO_BK_BRACES)
                      goto unfetch_interval;
                    else
                      FREE_STACK_RETURN (REG_BADBR);
                  }

                if (!(syntax & RE_NO_BK_BRACES))
                  {
                    if (c != '\\') FREE_STACK_RETURN (REG_EBRACE);

                    PATFETCH (c);
                  }

                if (c != '}')
                  {
                    if (syntax & RE_NO_BK_BRACES)
                      goto unfetch_interval;
                    else
                      FREE_STACK_RETURN (REG_BADBR);
                  }

                /* We just parsed a valid interval.  */

                /* If it's invalid to have no preceding re.  */
                if (!laststart)
                  {
                    if (syntax & RE_CONTEXT_INVALID_OPS)
                      FREE_STACK_RETURN (REG_BADRPT);
                    else if (syntax & RE_CONTEXT_INDEP_OPS)
                      laststart = b;
                    else
                      goto unfetch_interval;
                  }

                /* If the upper bound is zero, don't want to succeed at
                   all; jump from `laststart' to `b + 3', which will be
                   the end of the buffer after we insert the jump.  */
                 if (upper_bound == 0)
                   {
                     GET_BUFFER_SPACE (3);
                     INSERT_JUMP (jump, laststart, b + 3);
                     b += 3;
                   }

                 /* Otherwise, we have a nontrivial interval.  When
                    we're all done, the pattern will look like:
                      set_number_at <jump count> <upper bound>
                      set_number_at <succeed_n count> <lower bound>
                      succeed_n <after jump addr> <succeed_n count>
                      <body of loop>
                      jump_n <succeed_n addr> <jump count>
                    (The upper bound and `jump_n' are omitted if
                    `upper_bound' is 1, though.)  */
                 else
                   { /* If the upper bound is > 1, we need to insert
                        more at the end of the loop.  */
                     unsigned nbytes = 10 + (upper_bound > 1) * 10;

                     GET_BUFFER_SPACE (nbytes);

                     /* Initialize lower bound of the `succeed_n', even
                        though it will be set during matching by its
                        attendant `set_number_at' (inserted next),
                        because `re_compile_fastmap' needs to know.
                        Jump to the `jump_n' we might insert below.  */
                     INSERT_JUMP2 (succeed_n, laststart,
                                   b + 5 + (upper_bound > 1) * 5,
                                   lower_bound);
                     b += 5;

                     /* Code to initialize the lower bound.  Insert
                        before the `succeed_n'.  The `5' is the last two
                        bytes of this `set_number_at', plus 3 bytes of
                        the following `succeed_n'.  */
                     insert_op2 (set_number_at, laststart, 5, lower_bound, b);
                     b += 5;

                     if (upper_bound > 1)
                       { /* More than one repetition is allowed, so
                            append a backward jump to the `succeed_n'
                            that starts this interval.

                            When we've reached this during matching,
                            we'll have matched the interval once, so
                            jump back only `upper_bound - 1' times.  */
                         STORE_JUMP2 (jump_n, b, laststart + 5,
                                      upper_bound - 1);
                         b += 5;

                         /* The location we want to set is the second
                            parameter of the `jump_n'; that is `b-2' as
                            an absolute address.  `laststart' will be
                            the `set_number_at' we're about to insert;
                            `laststart+3' the number to set, the source
                            for the relative address.  But we are
                            inserting into the middle of the pattern --
                            so everything is getting moved up by 5.
                            Conclusion: (b - 2) - (laststart + 3) + 5,
                            i.e., b - laststart.

                            We insert this at the beginning of the loop
                            so that if we fail during matching, we'll
                            reinitialize the bounds.  */
                         insert_op2 (set_number_at, laststart, b - laststart,
                                     upper_bound - 1, b);
                         b += 5;
                       }
                   }
                pending_exact = 0;
                beg_interval = NULL;
              }
              break;

            unfetch_interval:
              /* If an invalid interval, match the characters as literals.  */
               assert (beg_interval);
               p = beg_interval;
               beg_interval = NULL;

               /* normal_char and normal_backslash need `c'.  */
               PATFETCH (c);

               if (!(syntax & RE_NO_BK_BRACES))
                 {
                   if (p > pattern  &&  p[-1] == '\\')
                     goto normal_backslash;
                 }
               goto normal_char;

#ifdef emacs
            /* There is no way to specify the before_dot and after_dot
               operators.  rms says this is ok.  --karl  */
            case '=':
              BUF_PUSH (at_dot);
              break;

            case 's':
              laststart = b;
              PATFETCH (c);
              BUF_PUSH_2 (syntaxspec, syntax_spec_code[c]);
              break;

            case 'S':
              laststart = b;
              PATFETCH (c);
              BUF_PUSH_2 (notsyntaxspec, syntax_spec_code[c]);
              break;
#endif /* emacs */


            case 'w':
	      if (syntax & RE_NO_GNU_OPS)
		goto normal_char;
              laststart = b;
              BUF_PUSH (wordchar);
              break;


            case 'W':
	      if (syntax & RE_NO_GNU_OPS)
		goto normal_char;
              laststart = b;
              BUF_PUSH (notwordchar);
              break;


            case '<':
	      if (syntax & RE_NO_GNU_OPS)
		goto normal_char;
              BUF_PUSH (wordbeg);
              break;

            case '>':
	      if (syntax & RE_NO_GNU_OPS)
		goto normal_char;
              BUF_PUSH (wordend);
              break;

            case 'b':
	      if (syntax & RE_NO_GNU_OPS)
		goto normal_char;
              BUF_PUSH (wordbound);
              break;

            case 'B':
	      if (syntax & RE_NO_GNU_OPS)
		goto normal_char;
              BUF_PUSH (notwordbound);
              break;

            case '`':
	      if (syntax & RE_NO_GNU_OPS)
		goto normal_char;
              BUF_PUSH (begbuf);
              break;

            case '\'':
	      if (syntax & RE_NO_GNU_OPS)
		goto normal_char;
              BUF_PUSH (endbuf);
              break;

            case '1': case '2': case '3': case '4': case '5':
            case '6': case '7': case '8': case '9':
              if (syntax & RE_NO_BK_REFS)
                goto normal_char;

              c1 = c - '0';

              if (c1 > regnum)
                FREE_STACK_RETURN (REG_ESUBREG);

              /* Can't back reference to a subexpression if inside of it.  */
              if (group_in_compile_stack (compile_stack, (regnum_t) c1))
                goto normal_char;

              laststart = b;
              BUF_PUSH_2 (duplicate, c1);
              break;


            case '+':
            case '?':
              if (syntax & RE_BK_PLUS_QM)
                goto handle_plus;
              else
                goto normal_backslash;

            default:
            normal_backslash:
              /* You might think it would be useful for \ to mean
                 not to translate; but if we don't translate it
                 it will never match anything.  */
              c = TRANSLATE (c);
              goto normal_char;
            }
          break;


	default:
        /* Expects the character in `c'.  */
	normal_char:
	      /* If no exactn currently being built.  */
          if (!pending_exact

              /* If last exactn not at current position.  */
              || pending_exact + *pending_exact + 1 != b

              /* We have only one byte following the exactn for the count.  */
	      || *pending_exact == (1 << BYTEWIDTH) - 1

              /* If followed by a repetition operator.  */
              || *p == '*' || *p == '^'
	      || ((syntax & RE_BK_PLUS_QM)
		  ? *p == '\\' && (p[1] == '+' || p[1] == '?')
		  : (*p == '+' || *p == '?'))
	      || ((syntax & RE_INTERVALS)
                  && ((syntax & RE_NO_BK_BRACES)
		      ? *p == '{'
                      : (p[0] == '\\' && p[1] == '{'))))
	    {
	      /* Start building a new exactn.  */

              laststart = b;

	      BUF_PUSH_2 (exactn, 0);
	      pending_exact = b - 1;
            }

	  BUF_PUSH (c);
          (*pending_exact)++;
	  break;
        } /* switch (c) */
    } /* while p != pend */


  /* Through the pattern now.  */

  if (fixup_alt_jump)
    STORE_JUMP (jump_past_alt, fixup_alt_jump, b);

  if (!COMPILE_STACK_EMPTY)
    FREE_STACK_RETURN (REG_EPAREN);

  /* If we don't want backtracking, force success
     the first time we reach the end of the compiled pattern.  */
  if (syntax & RE_NO_POSIX_BACKTRACKING)
    BUF_PUSH (succeed);

  free (compile_stack.stack);

  /* We have succeeded; set the length of the buffer.  */
  bufp->used = b - bufp->buffer;

#ifdef DEBUG
  if (debug)
    {
      DEBUG_PRINT1 ("\nCompiled pattern: \n");
      print_compiled_pattern (bufp);
    }
#endif /* DEBUG */

#ifndef MATCH_MAY_ALLOCATE
  /* Initialize the failure stack to the largest possible stack.  This
     isn't necessary unless we're trying to avoid calling alloca in
     the search and match routines.  */
  {
    int num_regs = bufp->re_nsub + 1;

    /* Since DOUBLE_FAIL_STACK refuses to double only if the current size
       is strictly greater than re_max_failures, the largest possible stack
       is 2 * re_max_failures failure points.  */
    if (fail_stack.size < (2 * re_max_failures * MAX_FAILURE_ITEMS))
      {
	fail_stack.size = (2 * re_max_failures * MAX_FAILURE_ITEMS);

# ifdef emacs
	if (! fail_stack.stack)
	  fail_stack.stack
	    = (fail_stack_elt_t *) xmalloc (fail_stack.size
					    * sizeof (fail_stack_elt_t));
	else
	  fail_stack.stack
	    = (fail_stack_elt_t *) xrealloc (fail_stack.stack,
					     (fail_stack.size
					      * sizeof (fail_stack_elt_t)));
# else /* not emacs */
	if (! fail_stack.stack)
	  fail_stack.stack
	    = (fail_stack_elt_t *) malloc (fail_stack.size
					   * sizeof (fail_stack_elt_t));
	else
	  fail_stack.stack
	    = (fail_stack_elt_t *) realloc (fail_stack.stack,
					    (fail_stack.size
					     * sizeof (fail_stack_elt_t)));
# endif /* not emacs */
      }

    regex_grow_registers (num_regs);
  }
#endif /* not MATCH_MAY_ALLOCATE */

  return REG_NOERROR;
} /* regex_compile */

/* Subroutines for `regex_compile'.  */

/* Store OP at LOC followed by two-byte integer parameter ARG.  */

static void
store_op1 (op, loc, arg)
    re_opcode_t op;
    unsigned char *loc;
    int arg;
{
  *loc = (unsigned char) op;
  STORE_NUMBER (loc + 1, arg);
}


/* Like `store_op1', but for two two-byte parameters ARG1 and ARG2.  */

static void
store_op2 (op, loc, arg1, arg2)
    re_opcode_t op;
    unsigned char *loc;
    int arg1, arg2;
{
  *loc = (unsigned char) op;
  STORE_NUMBER (loc + 1, arg1);
  STORE_NUMBER (loc + 3, arg2);
}


/* Copy the bytes from LOC to END to open up three bytes of space at LOC
   for OP followed by two-byte integer parameter ARG.  */

static void
insert_op1 (op, loc, arg, end)
    re_opcode_t op;
    unsigned char *loc;
    int arg;
    unsigned char *end;
{
  register unsigned char *pfrom = end;
  register unsigned char *pto = end + 3;

  while (pfrom != loc)
    *--pto = *--pfrom;

  store_op1 (op, loc, arg);
}


/* Like `insert_op1', but for two two-byte parameters ARG1 and ARG2.  */

static void
insert_op2 (op, loc, arg1, arg2, end)
    re_opcode_t op;
    unsigned char *loc;
    int arg1, arg2;
    unsigned char *end;
{
  register unsigned char *pfrom = end;
  register unsigned char *pto = end + 5;

  while (pfrom != loc)
    *--pto = *--pfrom;

  store_op2 (op, loc, arg1, arg2);
}


/* P points to just after a ^ in PATTERN.  Return true if that ^ comes
   after an alternative or a begin-subexpression.  We assume there is at
   least one character before the ^.  */

static boolean
at_begline_loc_p (pattern, p, syntax)
    const char *pattern, *p;
    reg_syntax_t syntax;
{
  const char *prev = p - 2;
  boolean prev_prev_backslash = prev > pattern && prev[-1] == '\\';

  return
       /* After a subexpression?  */
       (*prev == '(' && (syntax & RE_NO_BK_PARENS || prev_prev_backslash))
       /* After an alternative?  */
    || (*prev == '|' && (syntax & RE_NO_BK_VBAR || prev_prev_backslash));
}


/* The dual of at_begline_loc_p.  This one is for $.  We assume there is
   at least one character after the $, i.e., `P < PEND'.  */

static boolean
at_endline_loc_p (p, pend, syntax)
    const char *p, *pend;
    reg_syntax_t syntax;
{
  const char *next = p;
  boolean next_backslash = *next == '\\';
  const char *next_next = p + 1 < pend ? p + 1 : 0;

  return
       /* Before a subexpression?  */
       (syntax & RE_NO_BK_PARENS ? *next == ')'
        : next_backslash && next_next && *next_next == ')')
       /* Before an alternative?  */
    || (syntax & RE_NO_BK_VBAR ? *next == '|'
        : next_backslash && next_next && *next_next == '|');
}


/* Returns true if REGNUM is in one of COMPILE_STACK's elements and
   false if it's not.  */

static boolean
group_in_compile_stack (compile_stack, regnum)
    compile_stack_type compile_stack;
    regnum_t regnum;
{
  int this_element;

  for (this_element = compile_stack.avail - 1;
       this_element >= 0;
       this_element--)
    if (compile_stack.stack[this_element].regnum == regnum)
      return true;

  return false;
}


/* Read the ending character of a range (in a bracket expression) from the
   uncompiled pattern *P_PTR (which ends at PEND).  We assume the
   starting character is in `P[-2]'.  (`P[-1]' is the character `-'.)
   Then we set the translation of all bits between the starting and
   ending characters (inclusive) in the compiled pattern B.

   Return an error code.

   We use these short variable names so we can use the same macros as
   `regex_compile' itself.  */

static reg_errcode_t
compile_range (p_ptr, pend, translate, syntax, b)
    const char **p_ptr, *pend;
    RE_TRANSLATE_TYPE translate;
    reg_syntax_t syntax;
    unsigned char *b;
{
  unsigned this_char;

  const char *p = *p_ptr;
  unsigned int range_start, range_end;

  if (p == pend)
    return REG_ERANGE;

  /* Even though the pattern is a signed `char *', we need to fetch
     with unsigned char *'s; if the high bit of the pattern character
     is set, the range endpoints will be negative if we fetch using a
     signed char *.

     We also want to fetch the endpoints without translating them; the
     appropriate translation is done in the bit-setting loop below.  */
  /* The SVR4 compiler on the 3B2 had trouble with unsigned const char *.  */
  range_start = ((const unsigned char *) p)[-2];
  range_end   = ((const unsigned char *) p)[0];

  /* Have to increment the pointer into the pattern string, so the
     caller isn't still at the ending character.  */
  (*p_ptr)++;

  /* If the start is after the end, the range is empty.  */
  if (range_start > range_end)
    return syntax & RE_NO_EMPTY_RANGES ? REG_ERANGE : REG_NOERROR;

  /* Here we see why `this_char' has to be larger than an `unsigned
     char' -- the range is inclusive, so if `range_end' == 0xff
     (assuming 8-bit characters), we would otherwise go into an infinite
     loop, since all characters <= 0xff.  */
  for (this_char = range_start; this_char <= range_end; this_char++)
    {
      SET_LIST_BIT (TRANSLATE (this_char));
    }

  return REG_NOERROR;
}

/* re_compile_fastmap computes a ``fastmap'' for the compiled pattern in
   BUFP.  A fastmap records which of the (1 << BYTEWIDTH) possible
   characters can start a string that matches the pattern.  This fastmap
   is used by re_search to skip quickly over impossible starting points.

   The caller must supply the address of a (1 << BYTEWIDTH)-byte data
   area as BUFP->fastmap.

   We set the `fastmap', `fastmap_accurate', and `can_be_null' fields in
   the pattern buffer.

   Returns 0 if we succeed, -2 if an internal error.   */

int
re_compile_fastmap (bufp)
     struct re_pattern_buffer *bufp;
{
  int j, k;
#ifdef MATCH_MAY_ALLOCATE
  fail_stack_type fail_stack;
#endif
#ifndef REGEX_MALLOC
  char *destination;
#endif

  register char *fastmap = bufp->fastmap;
  unsigned char *pattern = bufp->buffer;
  unsigned char *p = pattern;
  register unsigned char *pend = pattern + bufp->used;

#ifdef REL_ALLOC
  /* This holds the pointer to the failure stack, when
     it is allocated relocatably.  */
  fail_stack_elt_t *failure_stack_ptr;
#endif

  /* Assume that each path through the pattern can be null until
     proven otherwise.  We set this false at the bottom of switch
     statement, to which we get only if a particular path doesn't
     match the empty string.  */
  boolean path_can_be_null = true;

  /* We aren't doing a `succeed_n' to begin with.  */
  boolean succeed_n_p = false;

  assert (fastmap != NULL && p != NULL);

  INIT_FAIL_STACK ();
  bzero (fastmap, 1 << BYTEWIDTH);  /* Assume nothing's valid.  */
  bufp->fastmap_accurate = 1;	    /* It will be when we're done.  */
  bufp->can_be_null = 0;

  while (1)
    {
      if (p == pend || *p == succeed)
	{
	  /* We have reached the (effective) end of pattern.  */
	  if (!FAIL_STACK_EMPTY ())
	    {
	      bufp->can_be_null |= path_can_be_null;

	      /* Reset for next path.  */
	      path_can_be_null = true;

	      p = fail_stack.stack[--fail_stack.avail].pointer;

	      continue;
	    }
	  else
	    break;
	}

      /* We should never be about to go beyond the end of the pattern.  */
      assert (p < pend);

      switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
	{

        /* I guess the idea here is to simply not bother with a fastmap
           if a backreference is used, since it's too hard to figure out
           the fastmap for the corresponding group.  Setting
           `can_be_null' stops `re_search_2' from using the fastmap, so
           that is all we do.  */
	case duplicate:
	  bufp->can_be_null = 1;
          goto done;


      /* Following are the cases which match a character.  These end
         with `break'.  */

	case exactn:
          fastmap[p[1]] = 1;
	  break;


        case charset:
          for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
	    if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))
              fastmap[j] = 1;
	  break;


	case charset_not:
	  /* Chars beyond end of map must be allowed.  */
	  for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++)
            fastmap[j] = 1;

	  for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--)
	    if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))))
              fastmap[j] = 1;
          break;


	case wordchar:
	  for (j = 0; j < (1 << BYTEWIDTH); j++)
	    if (SYNTAX (j) == Sword)
	      fastmap[j] = 1;
	  break;


	case notwordchar:
	  for (j = 0; j < (1 << BYTEWIDTH); j++)
	    if (SYNTAX (j) != Sword)
	      fastmap[j] = 1;
	  break;


        case anychar:
	  {
	    int fastmap_newline = fastmap['\n'];

	    /* `.' matches anything ...  */
	    for (j = 0; j < (1 << BYTEWIDTH); j++)
	      fastmap[j] = 1;

	    /* ... except perhaps newline.  */
	    if (!(bufp->syntax & RE_DOT_NEWLINE))
	      fastmap['\n'] = fastmap_newline;

	    /* Return if we have already set `can_be_null'; if we have,
	       then the fastmap is irrelevant.  Something's wrong here.  */
	    else if (bufp->can_be_null)
	      goto done;

	    /* Otherwise, have to check alternative paths.  */
	    break;
	  }

#ifdef emacs
        case syntaxspec:
	  k = *p++;
	  for (j = 0; j < (1 << BYTEWIDTH); j++)
	    if (SYNTAX (j) == (enum syntaxcode) k)
	      fastmap[j] = 1;
	  break;


	case notsyntaxspec:
	  k = *p++;
	  for (j = 0; j < (1 << BYTEWIDTH); j++)
	    if (SYNTAX (j) != (enum syntaxcode) k)
	      fastmap[j] = 1;
	  break;


      /* All cases after this match the empty string.  These end with
         `continue'.  */


	case before_dot:
	case at_dot:
	case after_dot:
          continue;
#endif /* emacs */


        case no_op:
        case begline:
        case endline:
	case begbuf:
	case endbuf:
	case wordbound:
	case notwordbound:
	case wordbeg:
	case wordend:
        case push_dummy_failure:
          continue;


	case jump_n:
        case pop_failure_jump:
	case maybe_pop_jump:
	case jump:
        case jump_past_alt:
	case dummy_failure_jump:
          EXTRACT_NUMBER_AND_INCR (j, p);
	  p += j;
	  if (j > 0)
	    continue;

          /* Jump backward implies we just went through the body of a
             loop and matched nothing.  Opcode jumped to should be
             `on_failure_jump' or `succeed_n'.  Just treat it like an
             ordinary jump.  For a * loop, it has pushed its failure
             point already; if so, discard that as redundant.  */
          if ((re_opcode_t) *p != on_failure_jump
	      && (re_opcode_t) *p != succeed_n)
	    continue;

          p++;
          EXTRACT_NUMBER_AND_INCR (j, p);
          p += j;

          /* If what's on the stack is where we are now, pop it.  */
          if (!FAIL_STACK_EMPTY ()
	      && fail_stack.stack[fail_stack.avail - 1].pointer == p)
            fail_stack.avail--;

          continue;


        case on_failure_jump:
        case on_failure_keep_string_jump:
	handle_on_failure_jump:
          EXTRACT_NUMBER_AND_INCR (j, p);

          /* For some patterns, e.g., `(a?)?', `p+j' here points to the
             end of the pattern.  We don't want to push such a point,
             since when we restore it above, entering the switch will
             increment `p' past the end of the pattern.  We don't need
             to push such a point since we obviously won't find any more
             fastmap entries beyond `pend'.  Such a pattern can match
             the null string, though.  */
          if (p + j < pend)
            {
              if (!PUSH_PATTERN_OP (p + j, fail_stack))
		{
		  RESET_FAIL_STACK ();
		  return -2;
		}
            }
          else
            bufp->can_be_null = 1;

          if (succeed_n_p)
            {
              EXTRACT_NUMBER_AND_INCR (k, p);	/* Skip the n.  */
              succeed_n_p = false;
	    }

          continue;


	case succeed_n:
          /* Get to the number of times to succeed.  */
          p += 2;

          /* Increment p past the n for when k != 0.  */
          EXTRACT_NUMBER_AND_INCR (k, p);
          if (k == 0)
	    {
              p -= 4;
  	      succeed_n_p = true;  /* Spaghetti code alert.  */
              goto handle_on_failure_jump;
            }
          continue;


	case set_number_at:
          p += 4;
          continue;


	case start_memory:
        case stop_memory:
	  p += 2;
	  continue;


	default:
          abort (); /* We have listed all the cases.  */
        } /* switch *p++ */

      /* Getting here means we have found the possible starting
         characters for one path of the pattern -- and that the empty
         string does not match.  We need not follow this path further.
         Instead, look at the next alternative (remembered on the
         stack), or quit if no more.  The test at the top of the loop
         does these things.  */
      path_can_be_null = false;
      p = pend;
    } /* while p */

  /* Set `can_be_null' for the last path (also the first path, if the
     pattern is empty).  */
  bufp->can_be_null |= path_can_be_null;

 done:
  RESET_FAIL_STACK ();
  return 0;
} /* re_compile_fastmap */
#ifdef _LIBC
weak_alias (__re_compile_fastmap, re_compile_fastmap)
#endif

/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
   ENDS.  Subsequent matches using PATTERN_BUFFER and REGS will use
   this memory for recording register information.  STARTS and ENDS
   must be allocated using the malloc library routine, and must each
   be at least NUM_REGS * sizeof (regoff_t) bytes long.

   If NUM_REGS == 0, then subsequent matches should allocate their own
   register data.

   Unless this function is called, the first search or match using
   PATTERN_BUFFER will allocate its own register data, without
   freeing the old data.  */

void
re_set_registers (bufp, regs, num_regs, starts, ends)
    struct re_pattern_buffer *bufp;
    struct re_registers *regs;
    unsigned num_regs;
    regoff_t *starts, *ends;
{
  if (num_regs)
    {
      bufp->regs_allocated = REGS_REALLOCATE;
      regs->num_regs = num_regs;
      regs->start = starts;
      regs->end = ends;
    }
  else
    {
      bufp->regs_allocated = REGS_UNALLOCATED;
      regs->num_regs = 0;
      regs->start = regs->end = (regoff_t *) 0;
    }
}
#ifdef _LIBC
weak_alias (__re_set_registers, re_set_registers)
#endif

/* Searching routines.  */

/* Like re_search_2, below, but only one string is specified, and
   doesn't let you say where to stop matching. */

int
re_search (bufp, string, size, startpos, range, regs)
     struct re_pattern_buffer *bufp;
     const char *string;
     int size, startpos, range;
     struct re_registers *regs;
{
  return re_search_2 (bufp, NULL, 0, string, size, startpos, range,
		      regs, size);
}
#ifdef _LIBC
weak_alias (__re_search, re_search)
#endif


/* Using the compiled pattern in BUFP->buffer, first tries to match the
   virtual concatenation of STRING1 and STRING2, starting first at index
   STARTPOS, then at STARTPOS + 1, and so on.

   STRING1 and STRING2 have length SIZE1 and SIZE2, respectively.

   RANGE is how far to scan while trying to match.  RANGE = 0 means try
   only at STARTPOS; in general, the last start tried is STARTPOS +
   RANGE.

   In REGS, return the indices of the virtual concatenation of STRING1
   and STRING2 that matched the entire BUFP->buffer and its contained
   subexpressions.

   Do not consider matching one past the index STOP in the virtual
   concatenation of STRING1 and STRING2.

   We return either the position in the strings at which the match was
   found, -1 if no match, or -2 if error (such as failure
   stack overflow).  */

int
re_search_2 (bufp, string1, size1, string2, size2, startpos, range, regs, stop)
     struct re_pattern_buffer *bufp;
     const char *string1, *string2;
     int size1, size2;
     int startpos;
     int range;
     struct re_registers *regs;
     int stop;
{
  int val;
  register char *fastmap = bufp->fastmap;
  register RE_TRANSLATE_TYPE translate = bufp->translate;
  int total_size = size1 + size2;
  int endpos = startpos + range;

  /* Check for out-of-range STARTPOS.  */
  if (startpos < 0 || startpos > total_size)
    return -1;

  /* Fix up RANGE if it might eventually take us outside
     the virtual concatenation of STRING1 and STRING2.
     Make sure we won't move STARTPOS below 0 or above TOTAL_SIZE.  */
  if (endpos < 0)
    range = 0 - startpos;
  else if (endpos > total_size)
    range = total_size - startpos;

  /* If the search isn't to be a backwards one, don't waste time in a
     search for a pattern that must be anchored.  */
  if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == begbuf && range > 0)
    {
      if (startpos > 0)
	return -1;
      else
	range = 1;
    }

#ifdef emacs
  /* In a forward search for something that starts with \=.
     don't keep searching past point.  */
  if (bufp->used > 0 && (re_opcode_t) bufp->buffer[0] == at_dot && range > 0)
    {
      range = PT - startpos;
      if (range <= 0)
	return -1;
    }
#endif /* emacs */

  /* Update the fastmap now if not correct already.  */
  if (fastmap && !bufp->fastmap_accurate)
    if (re_compile_fastmap (bufp) == -2)
      return -2;

  /* Loop through the string, looking for a place to start matching.  */
  for (;;)
    {
      /* If a fastmap is supplied, skip quickly over characters that
         cannot be the start of a match.  If the pattern can match the
         null string, however, we don't need to skip characters; we want
         the first null string.  */
      if (fastmap && startpos < total_size && !bufp->can_be_null)
	{
	  if (range > 0)	/* Searching forwards.  */
	    {
	      register const char *d;
	      register int lim = 0;
	      int irange = range;

              if (startpos < size1 && startpos + range >= size1)
                lim = range - (size1 - startpos);

	      d = (startpos >= size1 ? string2 - size1 : string1) + startpos;

              /* Written out as an if-else to avoid testing `translate'
                 inside the loop.  */
	      if (translate)
                while (range > lim
                       && !fastmap[(unsigned char)
				   translate[(unsigned char) *d++]])
                  range--;
	      else
                while (range > lim && !fastmap[(unsigned char) *d++])
                  range--;

	      startpos += irange - range;
	    }
	  else				/* Searching backwards.  */
	    {
	      register char c = (size1 == 0 || startpos >= size1
                                 ? string2[startpos - size1]
                                 : string1[startpos]);

	      if (!fastmap[(unsigned char) TRANSLATE (c)])
		goto advance;
	    }
	}

      /* If can't match the null string, and that's all we have left, fail.  */
      if (range >= 0 && startpos == total_size && fastmap
          && !bufp->can_be_null)
	return -1;

      val = re_match_2_internal (bufp, string1, size1, string2, size2,
				 startpos, regs, stop);
#ifndef REGEX_MALLOC
# ifdef C_ALLOCA
      alloca (0);
# endif
#endif

      if (val >= 0)
	return startpos;

      if (val == -2)
	return -2;

    advance:
      if (!range)
        break;
      else if (range > 0)
        {
          range--;
          startpos++;
        }
      else
        {
          range++;
          startpos--;
        }
    }
  return -1;
} /* re_search_2 */
#ifdef _LIBC
weak_alias (__re_search_2, re_search_2)
#endif

/* This converts PTR, a pointer into one of the search strings `string1'
   and `string2' into an offset from the beginning of that string.  */
#define POINTER_TO_OFFSET(ptr)			\
  (FIRST_STRING_P (ptr)				\
   ? ((regoff_t) ((ptr) - string1))		\
   : ((regoff_t) ((ptr) - string2 + size1)))

/* Macros for dealing with the split strings in re_match_2.  */

#define MATCHING_IN_FIRST_STRING  (dend == end_match_1)

/* Call before fetching a character with *d.  This switches over to
   string2 if necessary.  */
#define PREFETCH()							\
  while (d == dend)						    	\
    {									\
      /* End of string2 => fail.  */					\
      if (dend == end_match_2) 						\
        goto fail;							\
      /* End of string1 => advance to string2.  */ 			\
      d = string2;						        \
      dend = end_match_2;						\
    }


/* Test if at very beginning or at very end of the virtual concatenation
   of `string1' and `string2'.  If only one string, it's `string2'.  */
#define AT_STRINGS_BEG(d) ((d) == (size1 ? string1 : string2) || !size2)
#define AT_STRINGS_END(d) ((d) == end2)


/* Test if D points to a character which is word-constituent.  We have
   two special cases to check for: if past the end of string1, look at
   the first character in string2; and if before the beginning of
   string2, look at the last character in string1.  */
#define WORDCHAR_P(d)							\
  (SYNTAX ((d) == end1 ? *string2					\
           : (d) == string2 - 1 ? *(end1 - 1) : *(d))			\
   == Sword)

/* Disabled due to a compiler bug -- see comment at case wordbound */
#if 0
/* Test if the character before D and the one at D differ with respect
   to being word-constituent.  */
#define AT_WORD_BOUNDARY(d)						\
  (AT_STRINGS_BEG (d) || AT_STRINGS_END (d)				\
   || WORDCHAR_P (d - 1) != WORDCHAR_P (d))
#endif

/* Free everything we malloc.  */
#ifdef MATCH_MAY_ALLOCATE
# define FREE_VAR(var) if (var) REGEX_FREE (var); var = NULL
# define FREE_VARIABLES()						\
  do {									\
    REGEX_FREE_STACK (fail_stack.stack);				\
    FREE_VAR (regstart);						\
    FREE_VAR (regend);							\
    FREE_VAR (old_regstart);						\
    FREE_VAR (old_regend);						\
    FREE_VAR (best_regstart);						\
    FREE_VAR (best_regend);						\
    FREE_VAR (reg_info);						\
    FREE_VAR (reg_dummy);						\
    FREE_VAR (reg_info_dummy);						\
  } while (0)
#else
# define FREE_VARIABLES() ((void)0) /* Do nothing!  But inhibit gcc warning. */
#endif /* not MATCH_MAY_ALLOCATE */

/* These values must meet several constraints.  They must not be valid
   register values; since we have a limit of 255 registers (because
   we use only one byte in the pattern for the register number), we can
   use numbers larger than 255.  They must differ by 1, because of
   NUM_FAILURE_ITEMS above.  And the value for the lowest register must
   be larger than the value for the highest register, so we do not try
   to actually save any registers when none are active.  */
#define NO_HIGHEST_ACTIVE_REG (1 << BYTEWIDTH)
#define NO_LOWEST_ACTIVE_REG (NO_HIGHEST_ACTIVE_REG + 1)

/* Matching routines.  */

#ifndef emacs   /* Emacs never uses this.  */
/* re_match is like re_match_2 except it takes only a single string.  */

int
re_match (bufp, string, size, pos, regs)
     struct re_pattern_buffer *bufp;
     const char *string;
     int size, pos;
     struct re_registers *regs;
{
  int result = re_match_2_internal (bufp, NULL, 0, string, size,
				    pos, regs, size);
# ifndef REGEX_MALLOC
#  ifdef C_ALLOCA
  alloca (0);
#  endif
# endif
  return result;
}
# ifdef _LIBC
weak_alias (__re_match, re_match)
# endif
#endif /* not emacs */

static boolean group_match_null_string_p _RE_ARGS ((unsigned char **p,
						    unsigned char *end,
						register_info_type *reg_info));
static boolean alt_match_null_string_p _RE_ARGS ((unsigned char *p,
						  unsigned char *end,
						register_info_type *reg_info));
static boolean common_op_match_null_string_p _RE_ARGS ((unsigned char **p,
							unsigned char *end,
						register_info_type *reg_info));
static int bcmp_translate _RE_ARGS ((const char *s1, const char *s2,
				     int len, char *translate));

/* re_match_2 matches the compiled pattern in BUFP against the
   the (virtual) concatenation of STRING1 and STRING2 (of length SIZE1
   and SIZE2, respectively).  We start matching at POS, and stop
   matching at STOP.

   If REGS is non-null and the `no_sub' field of BUFP is nonzero, we
   store offsets for the substring each group matched in REGS.  See the
   documentation for exactly how many groups we fill.

   We return -1 if no match, -2 if an internal error (such as the
   failure stack overflowing).  Otherwise, we return the length of the
   matched substring.  */

int
re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
     struct re_pattern_buffer *bufp;
     const char *string1, *string2;
     int size1, size2;
     int pos;
     struct re_registers *regs;
     int stop;
{
  int result = re_match_2_internal (bufp, string1, size1, string2, size2,
				    pos, regs, stop);
#ifndef REGEX_MALLOC
# ifdef C_ALLOCA
  alloca (0);
# endif
#endif
  return result;
}
#ifdef _LIBC
weak_alias (__re_match_2, re_match_2)
#endif

/* This is a separate function so that we can force an alloca cleanup
   afterwards.  */
static int
re_match_2_internal (bufp, string1, size1, string2, size2, pos, regs, stop)
     struct re_pattern_buffer *bufp;
     const char *string1, *string2;
     int size1, size2;
     int pos;
     struct re_registers *regs;
     int stop;
{
  /* General temporaries.  */
  int mcnt;
  unsigned char *p1;

  /* Just past the end of the corresponding string.  */
  const char *end1, *end2;

  /* Pointers into string1 and string2, just past the last characters in
     each to consider matching.  */
  const char *end_match_1, *end_match_2;

  /* Where we are in the data, and the end of the current string.  */
  const char *d, *dend;

  /* Where we are in the pattern, and the end of the pattern.  */
  unsigned char *p = bufp->buffer;
  register unsigned char *pend = p + bufp->used;

  /* Mark the opcode just after a start_memory, so we can test for an
     empty subpattern when we get to the stop_memory.  */
  unsigned char *just_past_start_mem = 0;

  /* We use this to map every character in the string.  */
  RE_TRANSLATE_TYPE translate = bufp->translate;

  /* Failure point stack.  Each place that can handle a failure further
     down the line pushes a failure point on this stack.  It consists of
     restart, regend, and reg_info for all registers corresponding to
     the subexpressions we're currently inside, plus the number of such
     registers, and, finally, two char *'s.  The first char * is where
     to resume scanning the pattern; the second one is where to resume
     scanning the strings.  If the latter is zero, the failure point is
     a ``dummy''; if a failure happens and the failure point is a dummy,
     it gets discarded and the next next one is tried.  */
#ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global.  */
  fail_stack_type fail_stack;
#endif
#ifdef DEBUG
  static unsigned failure_id = 0;
  unsigned nfailure_points_pushed = 0, nfailure_points_popped = 0;
#endif

#ifdef REL_ALLOC
  /* This holds the pointer to the failure stack, when
     it is allocated relocatably.  */
  fail_stack_elt_t *failure_stack_ptr;
#endif

  /* We fill all the registers internally, independent of what we
     return, for use in backreferences.  The number here includes
     an element for register zero.  */
  size_t num_regs = bufp->re_nsub + 1;

  /* The currently active registers.  */
  active_reg_t lowest_active_reg = NO_LOWEST_ACTIVE_REG;
  active_reg_t highest_active_reg = NO_HIGHEST_ACTIVE_REG;

  /* Information on the contents of registers. These are pointers into
     the input strings; they record just what was matched (on this
     attempt) by a subexpression part of the pattern, that is, the
     regnum-th regstart pointer points to where in the pattern we began
     matching and the regnum-th regend points to right after where we
     stopped matching the regnum-th subexpression.  (The zeroth register
     keeps track of what the whole pattern matches.)  */
#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
  const char **regstart, **regend;
#endif

  /* If a group that's operated upon by a repetition operator fails to
     match anything, then the register for its start will need to be
     restored because it will have been set to wherever in the string we
     are when we last see its open-group operator.  Similarly for a
     register's end.  */
#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
  const char **old_regstart, **old_regend;
#endif

  /* The is_active field of reg_info helps us keep track of which (possibly
     nested) subexpressions we are currently in. The matched_something
     field of reg_info[reg_num] helps us tell whether or not we have
     matched any of the pattern so far this time through the reg_num-th
     subexpression.  These two fields get reset each time through any
     loop their register is in.  */
#ifdef MATCH_MAY_ALLOCATE /* otherwise, this is global.  */
  register_info_type *reg_info;
#endif

  /* The following record the register info as found in the above
     variables when we find a match better than any we've seen before.
     This happens as we backtrack through the failure points, which in
     turn happens only if we have not yet matched the entire string. */
  unsigned best_regs_set = false;
#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
  const char **best_regstart, **best_regend;
#endif

  /* Logically, this is `best_regend[0]'.  But we don't want to have to
     allocate space for that if we're not allocating space for anything
     else (see below).  Also, we never need info about register 0 for
     any of the other register vectors, and it seems rather a kludge to
     treat `best_regend' differently than the rest.  So we keep track of
     the end of the best match so far in a separate variable.  We
     initialize this to NULL so that when we backtrack the first time
     and need to test it, it's not garbage.  */
  const char *match_end = NULL;

  /* This helps SET_REGS_MATCHED avoid doing redundant work.  */
  int set_regs_matched_done = 0;

  /* Used when we pop values we don't care about.  */
#ifdef MATCH_MAY_ALLOCATE /* otherwise, these are global.  */
  const char **reg_dummy;
  register_info_type *reg_info_dummy;
#endif

#ifdef DEBUG
  /* Counts the total number of registers pushed.  */
  unsigned num_regs_pushed = 0;
#endif

  DEBUG_PRINT1 ("\n\nEntering re_match_2.\n");

  INIT_FAIL_STACK ();

#ifdef MATCH_MAY_ALLOCATE
  /* Do not bother to initialize all the register variables if there are
     no groups in the pattern, as it takes a fair amount of time.  If
     there are groups, we include space for register 0 (the whole
     pattern), even though we never use it, since it simplifies the
     array indexing.  We should fix this.  */
  if (bufp->re_nsub)
    {
      regstart = REGEX_TALLOC (num_regs, const char *);
      regend = REGEX_TALLOC (num_regs, const char *);
      old_regstart = REGEX_TALLOC (num_regs, const char *);
      old_regend = REGEX_TALLOC (num_regs, const char *);
      best_regstart = REGEX_TALLOC (num_regs, const char *);
      best_regend = REGEX_TALLOC (num_regs, const char *);
      reg_info = REGEX_TALLOC (num_regs, register_info_type);
      reg_dummy = REGEX_TALLOC (num_regs, const char *);
      reg_info_dummy = REGEX_TALLOC (num_regs, register_info_type);

      if (!(regstart && regend && old_regstart && old_regend && reg_info
            && best_regstart && best_regend && reg_dummy && reg_info_dummy))
        {
          FREE_VARIABLES ();
          return -2;
        }
    }
  else
    {
      /* We must initialize all our variables to NULL, so that
         `FREE_VARIABLES' doesn't try to free them.  */
      regstart = regend = old_regstart = old_regend = best_regstart
        = best_regend = reg_dummy = NULL;
      reg_info = reg_info_dummy = (register_info_type *) NULL;
    }
#endif /* MATCH_MAY_ALLOCATE */

  /* The starting position is bogus.  */
  if (pos < 0 || pos > size1 + size2)
    {
      FREE_VARIABLES ();
      return -1;
    }

  /* Initialize subexpression text positions to -1 to mark ones that no
     start_memory/stop_memory has been seen for. Also initialize the
     register information struct.  */
  for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
    {
      regstart[mcnt] = regend[mcnt]
        = old_regstart[mcnt] = old_regend[mcnt] = REG_UNSET_VALUE;

      REG_MATCH_NULL_STRING_P (reg_info[mcnt]) = MATCH_NULL_UNSET_VALUE;
      IS_ACTIVE (reg_info[mcnt]) = 0;
      MATCHED_SOMETHING (reg_info[mcnt]) = 0;
      EVER_MATCHED_SOMETHING (reg_info[mcnt]) = 0;
    }

  /* We move `string1' into `string2' if the latter's empty -- but not if
     `string1' is null.  */
  if (size2 == 0 && string1 != NULL)
    {
      string2 = string1;
      size2 = size1;
      string1 = 0;
      size1 = 0;
    }
  end1 = string1 + size1;
  end2 = string2 + size2;

  /* Compute where to stop matching, within the two strings.  */
  if (stop <= size1)
    {
      end_match_1 = string1 + stop;
      end_match_2 = string2;
    }
  else
    {
      end_match_1 = end1;
      end_match_2 = string2 + stop - size1;
    }

  /* `p' scans through the pattern as `d' scans through the data.
     `dend' is the end of the input string that `d' points within.  `d'
     is advanced into the following input string whenever necessary, but
     this happens before fetching; therefore, at the beginning of the
     loop, `d' can be pointing at the end of a string, but it cannot
     equal `string2'.  */
  if (size1 > 0 && pos <= size1)
    {
      d = string1 + pos;
      dend = end_match_1;
    }
  else
    {
      d = string2 + pos - size1;
      dend = end_match_2;
    }

  DEBUG_PRINT1 ("The compiled pattern is:\n");
  DEBUG_PRINT_COMPILED_PATTERN (bufp, p, pend);
  DEBUG_PRINT1 ("The string to match is: `");
  DEBUG_PRINT_DOUBLE_STRING (d, string1, size1, string2, size2);
  DEBUG_PRINT1 ("'\n");

  /* This loops over pattern commands.  It exits by returning from the
     function if the match is complete, or it drops through if the match
     fails at this starting point in the input data.  */
  for (;;)
    {
#ifdef _LIBC
      DEBUG_PRINT2 ("\n%p: ", p);
#else
      DEBUG_PRINT2 ("\n0x%x: ", p);
#endif

      if (p == pend)
	{ /* End of pattern means we might have succeeded.  */
          DEBUG_PRINT1 ("end of pattern ... ");

	  /* If we haven't matched the entire string, and we want the
             longest match, try backtracking.  */
          if (d != end_match_2)
	    {
	      /* 1 if this match ends in the same string (string1 or string2)
		 as the best previous match.  */
	      boolean same_str_p = (FIRST_STRING_P (match_end)
				    == MATCHING_IN_FIRST_STRING);
	      /* 1 if this match is the best seen so far.  */
	      boolean best_match_p;

	      /* AIX compiler got confused when this was combined
		 with the previous declaration.  */
	      if (same_str_p)
		best_match_p = d > match_end;
	      else
		best_match_p = !MATCHING_IN_FIRST_STRING;

              DEBUG_PRINT1 ("backtracking.\n");

              if (!FAIL_STACK_EMPTY ())
                { /* More failure points to try.  */

                  /* If exceeds best match so far, save it.  */
                  if (!best_regs_set || best_match_p)
                    {
                      best_regs_set = true;
                      match_end = d;

                      DEBUG_PRINT1 ("\nSAVING match as best so far.\n");

                      for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
                        {
                          best_regstart[mcnt] = regstart[mcnt];
                          best_regend[mcnt] = regend[mcnt];
                        }
                    }
                  goto fail;
                }

              /* If no failure points, don't restore garbage.  And if
                 last match is real best match, don't restore second
                 best one. */
              else if (best_regs_set && !best_match_p)
                {
  	        restore_best_regs:
                  /* Restore best match.  It may happen that `dend ==
                     end_match_1' while the restored d is in string2.
                     For example, the pattern `x.*y.*z' against the
                     strings `x-' and `y-z-', if the two strings are
                     not consecutive in memory.  */
                  DEBUG_PRINT1 ("Restoring best registers.\n");

                  d = match_end;
                  dend = ((d >= string1 && d <= end1)
		           ? end_match_1 : end_match_2);

		  for (mcnt = 1; (unsigned) mcnt < num_regs; mcnt++)
		    {
		      regstart[mcnt] = best_regstart[mcnt];
		      regend[mcnt] = best_regend[mcnt];
		    }
                }
            } /* d != end_match_2 */

	succeed_label:
          DEBUG_PRINT1 ("Accepting match.\n");

          /* If caller wants register contents data back, do it.  */
          if (regs && !bufp->no_sub)
	    {
              /* Have the register data arrays been allocated?  */
              if (bufp->regs_allocated == REGS_UNALLOCATED)
                { /* No.  So allocate them with malloc.  We need one
                     extra element beyond `num_regs' for the `-1' marker
                     GNU code uses.  */
                  regs->num_regs = MAX (RE_NREGS, num_regs + 1);
                  regs->start = TALLOC (regs->num_regs, regoff_t);
                  regs->end = TALLOC (regs->num_regs, regoff_t);
                  if (regs->start == NULL || regs->end == NULL)
		    {
		      FREE_VARIABLES ();
		      return -2;
		    }
                  bufp->regs_allocated = REGS_REALLOCATE;
                }
              else if (bufp->regs_allocated == REGS_REALLOCATE)
                { /* Yes.  If we need more elements than were already
                     allocated, reallocate them.  If we need fewer, just
                     leave it alone.  */
                  if (regs->num_regs < num_regs + 1)
                    {
                      regs->num_regs = num_regs + 1;
                      RETALLOC (regs->start, regs->num_regs, regoff_t);
                      RETALLOC (regs->end, regs->num_regs, regoff_t);
                      if (regs->start == NULL || regs->end == NULL)
			{
			  FREE_VARIABLES ();
			  return -2;
			}
                    }
                }
              else
		{
		  /* These braces fend off a "empty body in an else-statement"
		     warning under GCC when assert expands to nothing.  */
		  assert (bufp->regs_allocated == REGS_FIXED);
		}

              /* Convert the pointer data in `regstart' and `regend' to
                 indices.  Register zero has to be set differently,
                 since we haven't kept track of any info for it.  */
              if (regs->num_regs > 0)
                {
                  regs->start[0] = pos;
                  regs->end[0] = (MATCHING_IN_FIRST_STRING
				  ? ((regoff_t) (d - string1))
			          : ((regoff_t) (d - string2 + size1)));
                }

              /* Go through the first `min (num_regs, regs->num_regs)'
                 registers, since that is all we initialized.  */
	      for (mcnt = 1; (unsigned) mcnt < MIN (num_regs, regs->num_regs);
		   mcnt++)
		{
                  if (REG_UNSET (regstart[mcnt]) || REG_UNSET (regend[mcnt]))
                    regs->start[mcnt] = regs->end[mcnt] = -1;
                  else
                    {
		      regs->start[mcnt]
			= (regoff_t) POINTER_TO_OFFSET (regstart[mcnt]);
                      regs->end[mcnt]
			= (regoff_t) POINTER_TO_OFFSET (regend[mcnt]);
                    }
		}

              /* If the regs structure we return has more elements than
                 were in the pattern, set the extra elements to -1.  If
                 we (re)allocated the registers, this is the case,
                 because we always allocate enough to have at least one
                 -1 at the end.  */
              for (mcnt = num_regs; (unsigned) mcnt < regs->num_regs; mcnt++)
                regs->start[mcnt] = regs->end[mcnt] = -1;
	    } /* regs && !bufp->no_sub */

          DEBUG_PRINT4 ("%u failure points pushed, %u popped (%u remain).\n",
                        nfailure_points_pushed, nfailure_points_popped,
                        nfailure_points_pushed - nfailure_points_popped);
          DEBUG_PRINT2 ("%u registers pushed.\n", num_regs_pushed);

          mcnt = d - pos - (MATCHING_IN_FIRST_STRING
			    ? string1
			    : string2 - size1);

          DEBUG_PRINT2 ("Returning %d from re_match_2.\n", mcnt);

          FREE_VARIABLES ();
          return mcnt;
        }

      /* Otherwise match next pattern command.  */
      switch (SWITCH_ENUM_CAST ((re_opcode_t) *p++))
	{
        /* Ignore these.  Used to ignore the n of succeed_n's which
           currently have n == 0.  */
        case no_op:
          DEBUG_PRINT1 ("EXECUTING no_op.\n");
          break;

	case succeed:
          DEBUG_PRINT1 ("EXECUTING succeed.\n");
	  goto succeed_label;

        /* Match the next n pattern characters exactly.  The following
           byte in the pattern defines n, and the n bytes after that
           are the characters to match.  */
	case exactn:
	  mcnt = *p++;
          DEBUG_PRINT2 ("EXECUTING exactn %d.\n", mcnt);

          /* This is written out as an if-else so we don't waste time
             testing `translate' inside the loop.  */
          if (translate)
	    {
	      do
		{
		  PREFETCH ();
		  if ((unsigned char) translate[(unsigned char) *d++]
		      != (unsigned char) *p++)
                    goto fail;
		}
	      while (--mcnt);
	    }
	  else
	    {
	      do
		{
		  PREFETCH ();
		  if (*d++ != (char) *p++) goto fail;
		}
	      while (--mcnt);
	    }
	  SET_REGS_MATCHED ();
          break;


        /* Match any character except possibly a newline or a null.  */
	case anychar:
          DEBUG_PRINT1 ("EXECUTING anychar.\n");

          PREFETCH ();

          if ((!(bufp->syntax & RE_DOT_NEWLINE) && TRANSLATE (*d) == '\n')
              || (bufp->syntax & RE_DOT_NOT_NULL && TRANSLATE (*d) == '\000'))
	    goto fail;

          SET_REGS_MATCHED ();
          DEBUG_PRINT2 ("  Matched `%d'.\n", *d);
          d++;
	  break;


	case charset:
	case charset_not:
	  {
	    register unsigned char c;
	    boolean not = (re_opcode_t) *(p - 1) == charset_not;

            DEBUG_PRINT2 ("EXECUTING charset%s.\n", not ? "_not" : "");

	    PREFETCH ();
	    c = TRANSLATE (*d); /* The character to match.  */

            /* Cast to `unsigned' instead of `unsigned char' in case the
               bit list is a full 32 bytes long.  */
	    if (c < (unsigned) (*p * BYTEWIDTH)
		&& p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
	      not = !not;

	    p += 1 + *p;

	    if (!not) goto fail;

	    SET_REGS_MATCHED ();
            d++;
	    break;
	  }


        /* The beginning of a group is represented by start_memory.
           The arguments are the register number in the next byte, and the
           number of groups inner to this one in the next.  The text
           matched within the group is recorded (in the internal
           registers data structure) under the register number.  */
        case start_memory:
	  DEBUG_PRINT3 ("EXECUTING start_memory %d (%d):\n", *p, p[1]);

          /* Find out if this group can match the empty string.  */
	  p1 = p;		/* To send to group_match_null_string_p.  */

          if (REG_MATCH_NULL_STRING_P (reg_info[*p]) == MATCH_NULL_UNSET_VALUE)
            REG_MATCH_NULL_STRING_P (reg_info[*p])
              = group_match_null_string_p (&p1, pend, reg_info);

          /* Save the position in the string where we were the last time
             we were at this open-group operator in case the group is
             operated upon by a repetition operator, e.g., with `(a*)*b'
             against `ab'; then we want to ignore where we are now in
             the string in case this attempt to match fails.  */
          old_regstart[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
                             ? REG_UNSET (regstart[*p]) ? d : regstart[*p]
                             : regstart[*p];
	  DEBUG_PRINT2 ("  old_regstart: %d\n",
			 POINTER_TO_OFFSET (old_regstart[*p]));

          regstart[*p] = d;
	  DEBUG_PRINT2 ("  regstart: %d\n", POINTER_TO_OFFSET (regstart[*p]));

          IS_ACTIVE (reg_info[*p]) = 1;
          MATCHED_SOMETHING (reg_info[*p]) = 0;

	  /* Clear this whenever we change the register activity status.  */
	  set_regs_matched_done = 0;

          /* This is the new highest active register.  */
          highest_active_reg = *p;

          /* If nothing was active before, this is the new lowest active
             register.  */
          if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
            lowest_active_reg = *p;

          /* Move past the register number and inner group count.  */
          p += 2;
	  just_past_start_mem = p;

          break;


        /* The stop_memory opcode represents the end of a group.  Its
           arguments are the same as start_memory's: the register
           number, and the number of inner groups.  */
	case stop_memory:
	  DEBUG_PRINT3 ("EXECUTING stop_memory %d (%d):\n", *p, p[1]);

          /* We need to save the string position the last time we were at
             this close-group operator in case the group is operated
             upon by a repetition operator, e.g., with `((a*)*(b*)*)*'
             against `aba'; then we want to ignore where we are now in
             the string in case this attempt to match fails.  */
          old_regend[*p] = REG_MATCH_NULL_STRING_P (reg_info[*p])
                           ? REG_UNSET (regend[*p]) ? d : regend[*p]
			   : regend[*p];
	  DEBUG_PRINT2 ("      old_regend: %d\n",
			 POINTER_TO_OFFSET (old_regend[*p]));

          regend[*p] = d;
	  DEBUG_PRINT2 ("      regend: %d\n", POINTER_TO_OFFSET (regend[*p]));

          /* This register isn't active anymore.  */
          IS_ACTIVE (reg_info[*p]) = 0;

	  /* Clear this whenever we change the register activity status.  */
	  set_regs_matched_done = 0;

          /* If this was the only register active, nothing is active
             anymore.  */
          if (lowest_active_reg == highest_active_reg)
            {
              lowest_active_reg = NO_LOWEST_ACTIVE_REG;
              highest_active_reg = NO_HIGHEST_ACTIVE_REG;
            }
          else
            { /* We must scan for the new highest active register, since
                 it isn't necessarily one less than now: consider
                 (a(b)c(d(e)f)g).  When group 3 ends, after the f), the
                 new highest active register is 1.  */
              unsigned char r = *p - 1;
              while (r > 0 && !IS_ACTIVE (reg_info[r]))
                r--;

              /* If we end up at register zero, that means that we saved
                 the registers as the result of an `on_failure_jump', not
                 a `start_memory', and we jumped to past the innermost
                 `stop_memory'.  For example, in ((.)*) we save
                 registers 1 and 2 as a result of the *, but when we pop
                 back to the second ), we are at the stop_memory 1.
                 Thus, nothing is active.  */
	      if (r == 0)
                {
                  lowest_active_reg = NO_LOWEST_ACTIVE_REG;
                  highest_active_reg = NO_HIGHEST_ACTIVE_REG;
                }
              else
                highest_active_reg = r;
            }

          /* If just failed to match something this time around with a
             group that's operated on by a repetition operator, try to
             force exit from the ``loop'', and restore the register
             information for this group that we had before trying this
             last match.  */
          if ((!MATCHED_SOMETHING (reg_info[*p])
               || just_past_start_mem == p - 1)
	      && (p + 2) < pend)
            {
              boolean is_a_jump_n = false;

              p1 = p + 2;
              mcnt = 0;
              switch ((re_opcode_t) *p1++)
                {
                  case jump_n:
		    is_a_jump_n = true;
                  case pop_failure_jump:
		  case maybe_pop_jump:
		  case jump:
		  case dummy_failure_jump:
                    EXTRACT_NUMBER_AND_INCR (mcnt, p1);
		    if (is_a_jump_n)
		      p1 += 2;
                    break;

                  default:
                    /* do nothing */ ;
                }
	      p1 += mcnt;

              /* If the next operation is a jump backwards in the pattern
	         to an on_failure_jump right before the start_memory
                 corresponding to this stop_memory, exit from the loop
                 by forcing a failure after pushing on the stack the
                 on_failure_jump's jump in the pattern, and d.  */
              if (mcnt < 0 && (re_opcode_t) *p1 == on_failure_jump
                  && (re_opcode_t) p1[3] == start_memory && p1[4] == *p)
		{
                  /* If this group ever matched anything, then restore
                     what its registers were before trying this last
                     failed match, e.g., with `(a*)*b' against `ab' for
                     regstart[1], and, e.g., with `((a*)*(b*)*)*'
                     against `aba' for regend[3].

                     Also restore the registers for inner groups for,
                     e.g., `((a*)(b*))*' against `aba' (register 3 would
                     otherwise get trashed).  */

                  if (EVER_MATCHED_SOMETHING (reg_info[*p]))
		    {
		      unsigned r;

                      EVER_MATCHED_SOMETHING (reg_info[*p]) = 0;

		      /* Restore this and inner groups' (if any) registers.  */
                      for (r = *p; r < (unsigned) *p + (unsigned) *(p + 1);
			   r++)
                        {
                          regstart[r] = old_regstart[r];

                          /* xx why this test?  */
                          if (old_regend[r] >= regstart[r])
                            regend[r] = old_regend[r];
                        }
                    }
		  p1++;
                  EXTRACT_NUMBER_AND_INCR (mcnt, p1);
                  PUSH_FAILURE_POINT (p1 + mcnt, d, -2);

                  goto fail;
                }
            }

          /* Move past the register number and the inner group count.  */
          p += 2;
          break;


	/* \<digit> has been turned into a `duplicate' command which is
           followed by the numeric value of <digit> as the register number.  */
        case duplicate:
	  {
	    register const char *d2, *dend2;
	    int regno = *p++;   /* Get which register to match against.  */
	    DEBUG_PRINT2 ("EXECUTING duplicate %d.\n", regno);

	    /* Can't back reference a group which we've never matched.  */
            if (REG_UNSET (regstart[regno]) || REG_UNSET (regend[regno]))
              goto fail;

            /* Where in input to try to start matching.  */
            d2 = regstart[regno];

            /* Where to stop matching; if both the place to start and
               the place to stop matching are in the same string, then
               set to the place to stop, otherwise, for now have to use
               the end of the first string.  */

            dend2 = ((FIRST_STRING_P (regstart[regno])
		      == FIRST_STRING_P (regend[regno]))
		     ? regend[regno] : end_match_1);
	    for (;;)
	      {
		/* If necessary, advance to next segment in register
                   contents.  */
		while (d2 == dend2)
		  {
		    if (dend2 == end_match_2) break;
		    if (dend2 == regend[regno]) break;

                    /* End of string1 => advance to string2. */
                    d2 = string2;
                    dend2 = regend[regno];
		  }
		/* At end of register contents => success */
		if (d2 == dend2) break;

		/* If necessary, advance to next segment in data.  */
		PREFETCH ();

		/* How many characters left in this segment to match.  */
		mcnt = dend - d;

		/* Want how many consecutive characters we can match in
                   one shot, so, if necessary, adjust the count.  */
                if (mcnt > dend2 - d2)
		  mcnt = dend2 - d2;

		/* Compare that many; failure if mismatch, else move
                   past them.  */
		if (translate
                    ? bcmp_translate (d, d2, mcnt, translate)
                    : memcmp (d, d2, mcnt))
		  goto fail;
		d += mcnt, d2 += mcnt;

		/* Do this because we've match some characters.  */
		SET_REGS_MATCHED ();
	      }
	  }
	  break;


        /* begline matches the empty string at the beginning of the string
           (unless `not_bol' is set in `bufp'), and, if
           `newline_anchor' is set, after newlines.  */
	case begline:
          DEBUG_PRINT1 ("EXECUTING begline.\n");

          if (AT_STRINGS_BEG (d))
            {
              if (!bufp->not_bol) break;
            }
          else if (d[-1] == '\n' && bufp->newline_anchor)
            {
              break;
            }
          /* In all other cases, we fail.  */
          goto fail;


        /* endline is the dual of begline.  */
	case endline:
          DEBUG_PRINT1 ("EXECUTING endline.\n");

          if (AT_STRINGS_END (d))
            {
              if (!bufp->not_eol) break;
            }

          /* We have to ``prefetch'' the next character.  */
          else if ((d == end1 ? *string2 : *d) == '\n'
                   && bufp->newline_anchor)
            {
              break;
            }
          goto fail;


	/* Match at the very beginning of the data.  */
        case begbuf:
          DEBUG_PRINT1 ("EXECUTING begbuf.\n");
          if (AT_STRINGS_BEG (d))
            break;
          goto fail;


	/* Match at the very end of the data.  */
        case endbuf:
          DEBUG_PRINT1 ("EXECUTING endbuf.\n");
	  if (AT_STRINGS_END (d))
	    break;
          goto fail;


        /* on_failure_keep_string_jump is used to optimize `.*\n'.  It
           pushes NULL as the value for the string on the stack.  Then
           `pop_failure_point' will keep the current value for the
           string, instead of restoring it.  To see why, consider
           matching `foo\nbar' against `.*\n'.  The .* matches the foo;
           then the . fails against the \n.  But the next thing we want
           to do is match the \n against the \n; if we restored the
           string value, we would be back at the foo.

           Because this is used only in specific cases, we don't need to
           check all the things that `on_failure_jump' does, to make
           sure the right things get saved on the stack.  Hence we don't
           share its code.  The only reason to push anything on the
           stack at all is that otherwise we would have to change
           `anychar's code to do something besides goto fail in this
           case; that seems worse than this.  */
        case on_failure_keep_string_jump:
          DEBUG_PRINT1 ("EXECUTING on_failure_keep_string_jump");

          EXTRACT_NUMBER_AND_INCR (mcnt, p);
#ifdef _LIBC
          DEBUG_PRINT3 (" %d (to %p):\n", mcnt, p + mcnt);
#else
          DEBUG_PRINT3 (" %d (to 0x%x):\n", mcnt, p + mcnt);
#endif

          PUSH_FAILURE_POINT (p + mcnt, NULL, -2);
          break;


	/* Uses of on_failure_jump:

           Each alternative starts with an on_failure_jump that points
           to the beginning of the next alternative.  Each alternative
           except the last ends with a jump that in effect jumps past
           the rest of the alternatives.  (They really jump to the
           ending jump of the following alternative, because tensioning
           these jumps is a hassle.)

           Repeats start with an on_failure_jump that points past both
           the repetition text and either the following jump or
           pop_failure_jump back to this on_failure_jump.  */
	case on_failure_jump:
        on_failure:
          DEBUG_PRINT1 ("EXECUTING on_failure_jump");

          EXTRACT_NUMBER_AND_INCR (mcnt, p);
#ifdef _LIBC
          DEBUG_PRINT3 (" %d (to %p)", mcnt, p + mcnt);
#else
          DEBUG_PRINT3 (" %d (to 0x%x)", mcnt, p + mcnt);
#endif

          /* If this on_failure_jump comes right before a group (i.e.,
             the original * applied to a group), save the information
             for that group and all inner ones, so that if we fail back
             to this point, the group's information will be correct.
             For example, in \(a*\)*\1, we need the preceding group,
             and in \(zz\(a*\)b*\)\2, we need the inner group.  */

          /* We can't use `p' to check ahead because we push
             a failure point to `p + mcnt' after we do this.  */
          p1 = p;

          /* We need to skip no_op's before we look for the
             start_memory in case this on_failure_jump is happening as
             the result of a completed succeed_n, as in \(a\)\{1,3\}b\1
             against aba.  */
          while (p1 < pend && (re_opcode_t) *p1 == no_op)
            p1++;

          if (p1 < pend && (re_opcode_t) *p1 == start_memory)
            {
              /* We have a new highest active register now.  This will
                 get reset at the start_memory we are about to get to,
                 but we will have saved all the registers relevant to
                 this repetition op, as described above.  */
              highest_active_reg = *(p1 + 1) + *(p1 + 2);
              if (lowest_active_reg == NO_LOWEST_ACTIVE_REG)
                lowest_active_reg = *(p1 + 1);
            }

          DEBUG_PRINT1 (":\n");
          PUSH_FAILURE_POINT (p + mcnt, d, -2);
          break;


        /* A smart repeat ends with `maybe_pop_jump'.
	   We change it to either `pop_failure_jump' or `jump'.  */
        case maybe_pop_jump:
          EXTRACT_NUMBER_AND_INCR (mcnt, p);
          DEBUG_PRINT2 ("EXECUTING maybe_pop_jump %d.\n", mcnt);
          {
	    register unsigned char *p2 = p;

            /* Compare the beginning of the repeat with what in the
               pattern follows its end. If we can establish that there
               is nothing that they would both match, i.e., that we
               would have to backtrack because of (as in, e.g., `a*a')
               then we can change to pop_failure_jump, because we'll
               never have to backtrack.

               This is not true in the case of alternatives: in
               `(a|ab)*' we do need to backtrack to the `ab' alternative
               (e.g., if the string was `ab').  But instead of trying to
               detect that here, the alternative has put on a dummy
               failure point which is what we will end up popping.  */

	    /* Skip over open/close-group commands.
	       If what follows this loop is a ...+ construct,
	       look at what begins its body, since we will have to
	       match at least one of that.  */
	    while (1)
	      {
		if (p2 + 2 < pend
		    && ((re_opcode_t) *p2 == stop_memory
			|| (re_opcode_t) *p2 == start_memory))
		  p2 += 3;
		else if (p2 + 6 < pend
			 && (re_opcode_t) *p2 == dummy_failure_jump)
		  p2 += 6;
		else
		  break;
	      }

	    p1 = p + mcnt;
	    /* p1[0] ... p1[2] are the `on_failure_jump' corresponding
	       to the `maybe_finalize_jump' of this case.  Examine what
	       follows.  */

            /* If we're at the end of the pattern, we can change.  */
            if (p2 == pend)
	      {
		/* Consider what happens when matching ":\(.*\)"
		   against ":/".  I don't really understand this code
		   yet.  */
  	        p[-3] = (unsigned char) pop_failure_jump;
                DEBUG_PRINT1
                  ("  End of pattern: change to `pop_failure_jump'.\n");
              }

            else if ((re_opcode_t) *p2 == exactn
		     || (bufp->newline_anchor && (re_opcode_t) *p2 == endline))
	      {
		register unsigned char c
                  = *p2 == (unsigned char) endline ? '\n' : p2[2];

                if ((re_opcode_t) p1[3] == exactn && p1[5] != c)
                  {
  		    p[-3] = (unsigned char) pop_failure_jump;
                    DEBUG_PRINT3 ("  %c != %c => pop_failure_jump.\n",
                                  c, p1[5]);
                  }

		else if ((re_opcode_t) p1[3] == charset
			 || (re_opcode_t) p1[3] == charset_not)
		  {
		    int not = (re_opcode_t) p1[3] == charset_not;

		    if (c < (unsigned char) (p1[4] * BYTEWIDTH)
			&& p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH)))
		      not = !not;

                    /* `not' is equal to 1 if c would match, which means
                        that we can't change to pop_failure_jump.  */
		    if (!not)
                      {
  		        p[-3] = (unsigned char) pop_failure_jump;
                        DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
                      }
		  }
	      }
            else if ((re_opcode_t) *p2 == charset)
	      {
#ifdef DEBUG
		register unsigned char c
                  = *p2 == (unsigned char) endline ? '\n' : p2[2];
#endif

#if 0
                if ((re_opcode_t) p1[3] == exactn
		    && ! ((int) p2[1] * BYTEWIDTH > (int) p1[5]
			  && (p2[2 + p1[5] / BYTEWIDTH]
			      & (1 << (p1[5] % BYTEWIDTH)))))
#else
                if ((re_opcode_t) p1[3] == exactn
		    && ! ((int) p2[1] * BYTEWIDTH > (int) p1[4]
			  && (p2[2 + p1[4] / BYTEWIDTH]
			      & (1 << (p1[4] % BYTEWIDTH)))))
#endif
                  {
  		    p[-3] = (unsigned char) pop_failure_jump;
                    DEBUG_PRINT3 ("  %c != %c => pop_failure_jump.\n",
                                  c, p1[5]);
                  }

		else if ((re_opcode_t) p1[3] == charset_not)
		  {
		    int idx;
		    /* We win if the charset_not inside the loop
		       lists every character listed in the charset after.  */
		    for (idx = 0; idx < (int) p2[1]; idx++)
		      if (! (p2[2 + idx] == 0
			     || (idx < (int) p1[4]
				 && ((p2[2 + idx] & ~ p1[5 + idx]) == 0))))
			break;

		    if (idx == p2[1])
                      {
  		        p[-3] = (unsigned char) pop_failure_jump;
                        DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
                      }
		  }
		else if ((re_opcode_t) p1[3] == charset)
		  {
		    int idx;
		    /* We win if the charset inside the loop
		       has no overlap with the one after the loop.  */
		    for (idx = 0;
			 idx < (int) p2[1] && idx < (int) p1[4];
			 idx++)
		      if ((p2[2 + idx] & p1[5 + idx]) != 0)
			break;

		    if (idx == p2[1] || idx == p1[4])
                      {
  		        p[-3] = (unsigned char) pop_failure_jump;
                        DEBUG_PRINT1 ("  No match => pop_failure_jump.\n");
                      }
		  }
	      }
	  }
	  p -= 2;		/* Point at relative address again.  */
	  if ((re_opcode_t) p[-1] != pop_failure_jump)
	    {
	      p[-1] = (unsigned char) jump;
              DEBUG_PRINT1 ("  Match => jump.\n");
	      goto unconditional_jump;
	    }
        /* Note fall through.  */


	/* The end of a simple repeat has a pop_failure_jump back to
           its matching on_failure_jump, where the latter will push a
           failure point.  The pop_failure_jump takes off failure
           points put on by this pop_failure_jump's matching
           on_failure_jump; we got through the pattern to here from the
           matching on_failure_jump, so didn't fail.  */
        case pop_failure_jump:
          {
            /* We need to pass separate storage for the lowest and
               highest registers, even though we don't care about the
               actual values.  Otherwise, we will restore only one
               register from the stack, since lowest will == highest in
               `pop_failure_point'.  */
            active_reg_t dummy_low_reg, dummy_high_reg;
            unsigned char *pdummy;
            const char *sdummy;

            DEBUG_PRINT1 ("EXECUTING pop_failure_jump.\n");
            POP_FAILURE_POINT (sdummy, pdummy,
                               dummy_low_reg, dummy_high_reg,
                               reg_dummy, reg_dummy, reg_info_dummy);
          }
	  /* Note fall through.  */

	unconditional_jump:
#ifdef _LIBC
	  DEBUG_PRINT2 ("\n%p: ", p);
#else
	  DEBUG_PRINT2 ("\n0x%x: ", p);
#endif
          /* Note fall through.  */

        /* Unconditionally jump (without popping any failure points).  */
        case jump:
	  EXTRACT_NUMBER_AND_INCR (mcnt, p);	/* Get the amount to jump.  */
          DEBUG_PRINT2 ("EXECUTING jump %d ", mcnt);
	  p += mcnt;				/* Do the jump.  */
#ifdef _LIBC
          DEBUG_PRINT2 ("(to %p).\n", p);
#else
          DEBUG_PRINT2 ("(to 0x%x).\n", p);
#endif
	  break;


        /* We need this opcode so we can detect where alternatives end
           in `group_match_null_string_p' et al.  */
        case jump_past_alt:
          DEBUG_PRINT1 ("EXECUTING jump_past_alt.\n");
          goto unconditional_jump;


        /* Normally, the on_failure_jump pushes a failure point, which
           then gets popped at pop_failure_jump.  We will end up at
           pop_failure_jump, also, and with a pattern of, say, `a+', we
           are skipping over the on_failure_jump, so we have to push
           something meaningless for pop_failure_jump to pop.  */
        case dummy_failure_jump:
          DEBUG_PRINT1 ("EXECUTING dummy_failure_jump.\n");
          /* It doesn't matter what we push for the string here.  What
             the code at `fail' tests is the value for the pattern.  */
          PUSH_FAILURE_POINT (NULL, NULL, -2);
          goto unconditional_jump;


        /* At the end of an alternative, we need to push a dummy failure
           point in case we are followed by a `pop_failure_jump', because
           we don't want the failure point for the alternative to be
           popped.  For example, matching `(a|ab)*' against `aab'
           requires that we match the `ab' alternative.  */
        case push_dummy_failure:
          DEBUG_PRINT1 ("EXECUTING push_dummy_failure.\n");
          /* See comments just above at `dummy_failure_jump' about the
             two zeroes.  */
          PUSH_FAILURE_POINT (NULL, NULL, -2);
          break;

        /* Have to succeed matching what follows at least n times.
           After that, handle like `on_failure_jump'.  */
        case succeed_n:
          EXTRACT_NUMBER (mcnt, p + 2);
          DEBUG_PRINT2 ("EXECUTING succeed_n %d.\n", mcnt);

          assert (mcnt >= 0);
          /* Originally, this is how many times we HAVE to succeed.  */
          if (mcnt > 0)
            {
               mcnt--;
	       p += 2;
               STORE_NUMBER_AND_INCR (p, mcnt);
#ifdef _LIBC
               DEBUG_PRINT3 ("  Setting %p to %d.\n", p - 2, mcnt);
#else
               DEBUG_PRINT3 ("  Setting 0x%x to %d.\n", p - 2, mcnt);
#endif
            }
	  else if (mcnt == 0)
            {
#ifdef _LIBC
              DEBUG_PRINT2 ("  Setting two bytes from %p to no_op.\n", p+2);
#else
              DEBUG_PRINT2 ("  Setting two bytes from 0x%x to no_op.\n", p+2);
#endif
	      p[2] = (unsigned char) no_op;
              p[3] = (unsigned char) no_op;
              goto on_failure;
            }
          break;

        case jump_n:
          EXTRACT_NUMBER (mcnt, p + 2);
          DEBUG_PRINT2 ("EXECUTING jump_n %d.\n", mcnt);

          /* Originally, this is how many times we CAN jump.  */
          if (mcnt)
            {
               mcnt--;
               STORE_NUMBER (p + 2, mcnt);
#ifdef _LIBC
               DEBUG_PRINT3 ("  Setting %p to %d.\n", p + 2, mcnt);
#else
               DEBUG_PRINT3 ("  Setting 0x%x to %d.\n", p + 2, mcnt);
#endif
	       goto unconditional_jump;
            }
          /* If don't have to jump any more, skip over the rest of command.  */
	  else
	    p += 4;
          break;

	case set_number_at:
	  {
            DEBUG_PRINT1 ("EXECUTING set_number_at.\n");

            EXTRACT_NUMBER_AND_INCR (mcnt, p);
            p1 = p + mcnt;
            EXTRACT_NUMBER_AND_INCR (mcnt, p);
#ifdef _LIBC
            DEBUG_PRINT3 ("  Setting %p to %d.\n", p1, mcnt);
#else
            DEBUG_PRINT3 ("  Setting 0x%x to %d.\n", p1, mcnt);
#endif
	    STORE_NUMBER (p1, mcnt);
            break;
          }

#if 0
	/* The DEC Alpha C compiler 3.x generates incorrect code for the
	   test  WORDCHAR_P (d - 1) != WORDCHAR_P (d)  in the expansion of
	   AT_WORD_BOUNDARY, so this code is disabled.  Expanding the
	   macro and introducing temporary variables works around the bug.  */

	case wordbound:
	  DEBUG_PRINT1 ("EXECUTING wordbound.\n");
	  if (AT_WORD_BOUNDARY (d))
	    break;
	  goto fail;

	case notwordbound:
	  DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
	  if (AT_WORD_BOUNDARY (d))
	    goto fail;
	  break;
#else
	case wordbound:
	{
	  boolean prevchar, thischar;

	  DEBUG_PRINT1 ("EXECUTING wordbound.\n");
	  if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
	    break;

	  prevchar = WORDCHAR_P (d - 1);
	  thischar = WORDCHAR_P (d);
	  if (prevchar != thischar)
	    break;
	  goto fail;
	}

      case notwordbound:
	{
	  boolean prevchar, thischar;

	  DEBUG_PRINT1 ("EXECUTING notwordbound.\n");
	  if (AT_STRINGS_BEG (d) || AT_STRINGS_END (d))
	    goto fail;

	  prevchar = WORDCHAR_P (d - 1);
	  thischar = WORDCHAR_P (d);
	  if (prevchar != thischar)
	    goto fail;
	  break;
	}
#endif

	case wordbeg:
          DEBUG_PRINT1 ("EXECUTING wordbeg.\n");
	  if (WORDCHAR_P (d) && (AT_STRINGS_BEG (d) || !WORDCHAR_P (d - 1)))
	    break;
          goto fail;

	case wordend:
          DEBUG_PRINT1 ("EXECUTING wordend.\n");
	  if (!AT_STRINGS_BEG (d) && WORDCHAR_P (d - 1)
              && (!WORDCHAR_P (d) || AT_STRINGS_END (d)))
	    break;
          goto fail;

#ifdef emacs
  	case before_dot:
          DEBUG_PRINT1 ("EXECUTING before_dot.\n");
 	  if (PTR_CHAR_POS ((unsigned char *) d) >= point)
  	    goto fail;
  	  break;

  	case at_dot:
          DEBUG_PRINT1 ("EXECUTING at_dot.\n");
 	  if (PTR_CHAR_POS ((unsigned char *) d) != point)
  	    goto fail;
  	  break;

  	case after_dot:
          DEBUG_PRINT1 ("EXECUTING after_dot.\n");
          if (PTR_CHAR_POS ((unsigned char *) d) <= point)
  	    goto fail;
  	  break;

	case syntaxspec:
          DEBUG_PRINT2 ("EXECUTING syntaxspec %d.\n", mcnt);
	  mcnt = *p++;
	  goto matchsyntax;

        case wordchar:
          DEBUG_PRINT1 ("EXECUTING Emacs wordchar.\n");
	  mcnt = (int) Sword;
        matchsyntax:
	  PREFETCH ();
	  /* Can't use *d++ here; SYNTAX may be an unsafe macro.  */
	  d++;
	  if (SYNTAX (d[-1]) != (enum syntaxcode) mcnt)
	    goto fail;
          SET_REGS_MATCHED ();
	  break;

	case notsyntaxspec:
          DEBUG_PRINT2 ("EXECUTING notsyntaxspec %d.\n", mcnt);
	  mcnt = *p++;
	  goto matchnotsyntax;

        case notwordchar:
          DEBUG_PRINT1 ("EXECUTING Emacs notwordchar.\n");
	  mcnt = (int) Sword;
        matchnotsyntax:
	  PREFETCH ();
	  /* Can't use *d++ here; SYNTAX may be an unsafe macro.  */
	  d++;
	  if (SYNTAX (d[-1]) == (enum syntaxcode) mcnt)
	    goto fail;
	  SET_REGS_MATCHED ();
          break;

#else /* not emacs */
	case wordchar:
          DEBUG_PRINT1 ("EXECUTING non-Emacs wordchar.\n");
	  PREFETCH ();
          if (!WORDCHAR_P (d))
            goto fail;
	  SET_REGS_MATCHED ();
          d++;
	  break;

	case notwordchar:
          DEBUG_PRINT1 ("EXECUTING non-Emacs notwordchar.\n");
	  PREFETCH ();
	  if (WORDCHAR_P (d))
            goto fail;
          SET_REGS_MATCHED ();
          d++;
	  break;
#endif /* not emacs */

        default:
          abort ();
	}
      continue;  /* Successfully executed one pattern command; keep going.  */


    /* We goto here if a matching operation fails. */
    fail:
      if (!FAIL_STACK_EMPTY ())
	{ /* A restart point is known.  Restore to that state.  */
          DEBUG_PRINT1 ("\nFAIL:\n");
          POP_FAILURE_POINT (d, p,
                             lowest_active_reg, highest_active_reg,
                             regstart, regend, reg_info);

          /* If this failure point is a dummy, try the next one.  */
          if (!p)
	    goto fail;

          /* If we failed to the end of the pattern, don't examine *p.  */
	  assert (p <= pend);
          if (p < pend)
            {
              boolean is_a_jump_n = false;

              /* If failed to a backwards jump that's part of a repetition
                 loop, need to pop this failure point and use the next one.  */
              switch ((re_opcode_t) *p)
                {
                case jump_n:
                  is_a_jump_n = true;
                case maybe_pop_jump:
                case pop_failure_jump:
                case jump:
                  p1 = p + 1;
                  EXTRACT_NUMBER_AND_INCR (mcnt, p1);
                  p1 += mcnt;

                  if ((is_a_jump_n && (re_opcode_t) *p1 == succeed_n)
                      || (!is_a_jump_n
                          && (re_opcode_t) *p1 == on_failure_jump))
                    goto fail;
                  break;
                default:
                  /* do nothing */ ;
                }
            }

          if (d >= string1 && d <= end1)
	    dend = end_match_1;
        }
      else
        break;   /* Matching at this starting point really fails.  */
    } /* for (;;) */

  if (best_regs_set)
    goto restore_best_regs;

  FREE_VARIABLES ();

  return -1;         			/* Failure to match.  */
} /* re_match_2 */

/* Subroutine definitions for re_match_2.  */


/* We are passed P pointing to a register number after a start_memory.

   Return true if the pattern up to the corresponding stop_memory can
   match the empty string, and false otherwise.

   If we find the matching stop_memory, sets P to point to one past its number.
   Otherwise, sets P to an undefined byte less than or equal to END.

   We don't handle duplicates properly (yet).  */

static boolean
group_match_null_string_p (p, end, reg_info)
    unsigned char **p, *end;
    register_info_type *reg_info;
{
  int mcnt;
  /* Point to after the args to the start_memory.  */
  unsigned char *p1 = *p + 2;

  while (p1 < end)
    {
      /* Skip over opcodes that can match nothing, and return true or
	 false, as appropriate, when we get to one that can't, or to the
         matching stop_memory.  */

      switch ((re_opcode_t) *p1)
        {
        /* Could be either a loop or a series of alternatives.  */
        case on_failure_jump:
          p1++;
          EXTRACT_NUMBER_AND_INCR (mcnt, p1);

          /* If the next operation is not a jump backwards in the
	     pattern.  */

	  if (mcnt >= 0)
	    {
              /* Go through the on_failure_jumps of the alternatives,
                 seeing if any of the alternatives cannot match nothing.
                 The last alternative starts with only a jump,
                 whereas the rest start with on_failure_jump and end
                 with a jump, e.g., here is the pattern for `a|b|c':

                 /on_failure_jump/0/6/exactn/1/a/jump_past_alt/0/6
                 /on_failure_jump/0/6/exactn/1/b/jump_past_alt/0/3
                 /exactn/1/c

                 So, we have to first go through the first (n-1)
                 alternatives and then deal with the last one separately.  */


              /* Deal with the first (n-1) alternatives, which start
                 with an on_failure_jump (see above) that jumps to right
                 past a jump_past_alt.  */

              while ((re_opcode_t) p1[mcnt-3] == jump_past_alt)
                {
                  /* `mcnt' holds how many bytes long the alternative
                     is, including the ending `jump_past_alt' and
                     its number.  */

                  if (!alt_match_null_string_p (p1, p1 + mcnt - 3,
				                      reg_info))
                    return false;

                  /* Move to right after this alternative, including the
		     jump_past_alt.  */
                  p1 += mcnt;

                  /* Break if it's the beginning of an n-th alternative
                     that doesn't begin with an on_failure_jump.  */
                  if ((re_opcode_t) *p1 != on_failure_jump)
                    break;

		  /* Still have to check that it's not an n-th
		     alternative that starts with an on_failure_jump.  */
		  p1++;
                  EXTRACT_NUMBER_AND_INCR (mcnt, p1);
                  if ((re_opcode_t) p1[mcnt-3] != jump_past_alt)
                    {
		      /* Get to the beginning of the n-th alternative.  */
                      p1 -= 3;
                      break;
                    }
                }

              /* Deal with the last alternative: go back and get number
                 of the `jump_past_alt' just before it.  `mcnt' contains
                 the length of the alternative.  */
              EXTRACT_NUMBER (mcnt, p1 - 2);

              if (!alt_match_null_string_p (p1, p1 + mcnt, reg_info))
                return false;

              p1 += mcnt;	/* Get past the n-th alternative.  */
            } /* if mcnt > 0 */
          break;


        case stop_memory:
	  assert (p1[1] == **p);
          *p = p1 + 2;
          return true;


        default:
          if (!common_op_match_null_string_p (&p1, end, reg_info))
            return false;
        }
    } /* while p1 < end */

  return false;
} /* group_match_null_string_p */


/* Similar to group_match_null_string_p, but doesn't deal with alternatives:
   It expects P to be the first byte of a single alternative and END one
   byte past the last. The alternative can contain groups.  */

static boolean
alt_match_null_string_p (p, end, reg_info)
    unsigned char *p, *end;
    register_info_type *reg_info;
{
  int mcnt;
  unsigned char *p1 = p;

  while (p1 < end)
    {
      /* Skip over opcodes that can match nothing, and break when we get
         to one that can't.  */

      switch ((re_opcode_t) *p1)
        {
	/* It's a loop.  */
        case on_failure_jump:
          p1++;
          EXTRACT_NUMBER_AND_INCR (mcnt, p1);
          p1 += mcnt;
          break;

	default:
          if (!common_op_match_null_string_p (&p1, end, reg_info))
            return false;
        }
    }  /* while p1 < end */

  return true;
} /* alt_match_null_string_p */


/* Deals with the ops common to group_match_null_string_p and
   alt_match_null_string_p.

   Sets P to one after the op and its arguments, if any.  */

static boolean
common_op_match_null_string_p (p, end, reg_info)
    unsigned char **p, *end;
    register_info_type *reg_info;
{
  int mcnt;
  boolean ret;
  int reg_no;
  unsigned char *p1 = *p;

  switch ((re_opcode_t) *p1++)
    {
    case no_op:
    case begline:
    case endline:
    case begbuf:
    case endbuf:
    case wordbeg:
    case wordend:
    case wordbound:
    case notwordbound:
#ifdef emacs
    case before_dot:
    case at_dot:
    case after_dot:
#endif
      break;

    case start_memory:
      reg_no = *p1;
      assert (reg_no > 0 && reg_no <= MAX_REGNUM);
      ret = group_match_null_string_p (&p1, end, reg_info);

      /* Have to set this here in case we're checking a group which
         contains a group and a back reference to it.  */

      if (REG_MATCH_NULL_STRING_P (reg_info[reg_no]) == MATCH_NULL_UNSET_VALUE)
        REG_MATCH_NULL_STRING_P (reg_info[reg_no]) = ret;

      if (!ret)
        return false;
      break;

    /* If this is an optimized succeed_n for zero times, make the jump.  */
    case jump:
      EXTRACT_NUMBER_AND_INCR (mcnt, p1);
      if (mcnt >= 0)
        p1 += mcnt;
      else
        return false;
      break;

    case succeed_n:
      /* Get to the number of times to succeed.  */
      p1 += 2;
      EXTRACT_NUMBER_AND_INCR (mcnt, p1);

      if (mcnt == 0)
        {
          p1 -= 4;
          EXTRACT_NUMBER_AND_INCR (mcnt, p1);
          p1 += mcnt;
        }
      else
        return false;
      break;

    case duplicate:
      if (!REG_MATCH_NULL_STRING_P (reg_info[*p1]))
        return false;
      break;

    case set_number_at:
      p1 += 4;

    default:
      /* All other opcodes mean we cannot match the empty string.  */
      return false;
  }

  *p = p1;
  return true;
} /* common_op_match_null_string_p */


/* Return zero if TRANSLATE[S1] and TRANSLATE[S2] are identical for LEN
   bytes; nonzero otherwise.  */

static int