aboutsummaryrefslogtreecommitdiff
blob: 93bb0a0538a1f010b263bc8bca108ad3e54afee0 (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
/* Extended regular expression matching and search library.
   Copyright (C) 2002-2020 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#ifdef _LIBC
# include <locale/weight.h>
#endif

static reg_errcode_t re_compile_internal (regex_t *preg, const char * pattern,
					  size_t length, reg_syntax_t syntax);
static void re_compile_fastmap_iter (regex_t *bufp,
				     const re_dfastate_t *init_state,
				     char *fastmap);
static reg_errcode_t init_dfa (re_dfa_t *dfa, size_t pat_len);
#ifdef RE_ENABLE_I18N
static void free_charset (re_charset_t *cset);
#endif /* RE_ENABLE_I18N */
static void free_workarea_compile (regex_t *preg);
static reg_errcode_t create_initial_state (re_dfa_t *dfa);
#ifdef RE_ENABLE_I18N
static void optimize_utf8 (re_dfa_t *dfa);
#endif
static reg_errcode_t analyze (regex_t *preg);
static reg_errcode_t preorder (bin_tree_t *root,
			       reg_errcode_t (fn (void *, bin_tree_t *)),
			       void *extra);
static reg_errcode_t postorder (bin_tree_t *root,
				reg_errcode_t (fn (void *, bin_tree_t *)),
				void *extra);
static reg_errcode_t optimize_subexps (void *extra, bin_tree_t *node);
static reg_errcode_t lower_subexps (void *extra, bin_tree_t *node);
static bin_tree_t *lower_subexp (reg_errcode_t *err, regex_t *preg,
				 bin_tree_t *node);
static reg_errcode_t calc_first (void *extra, bin_tree_t *node);
static reg_errcode_t calc_next (void *extra, bin_tree_t *node);
static reg_errcode_t link_nfa_nodes (void *extra, bin_tree_t *node);
static Idx duplicate_node (re_dfa_t *dfa, Idx org_idx, unsigned int constraint);
static Idx search_duplicated_node (const re_dfa_t *dfa, Idx org_node,
				   unsigned int constraint);
static reg_errcode_t calc_eclosure (re_dfa_t *dfa);
static reg_errcode_t calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa,
					 Idx node, bool root);
static reg_errcode_t calc_inveclosure (re_dfa_t *dfa);
static Idx fetch_number (re_string_t *input, re_token_t *token,
			 reg_syntax_t syntax);
static int peek_token (re_token_t *token, re_string_t *input,
			reg_syntax_t syntax);
static bin_tree_t *parse (re_string_t *regexp, regex_t *preg,
			  reg_syntax_t syntax, reg_errcode_t *err);
static bin_tree_t *parse_reg_exp (re_string_t *regexp, regex_t *preg,
				  re_token_t *token, reg_syntax_t syntax,
				  Idx nest, reg_errcode_t *err);
static bin_tree_t *parse_branch (re_string_t *regexp, regex_t *preg,
				 re_token_t *token, reg_syntax_t syntax,
				 Idx nest, reg_errcode_t *err);
static bin_tree_t *parse_expression (re_string_t *regexp, regex_t *preg,
				     re_token_t *token, reg_syntax_t syntax,
				     Idx nest, reg_errcode_t *err);
static bin_tree_t *parse_sub_exp (re_string_t *regexp, regex_t *preg,
				  re_token_t *token, reg_syntax_t syntax,
				  Idx nest, reg_errcode_t *err);
static bin_tree_t *parse_dup_op (bin_tree_t *dup_elem, re_string_t *regexp,
				 re_dfa_t *dfa, re_token_t *token,
				 reg_syntax_t syntax, reg_errcode_t *err);
static bin_tree_t *parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa,
				      re_token_t *token, reg_syntax_t syntax,
				      reg_errcode_t *err);
static reg_errcode_t parse_bracket_element (bracket_elem_t *elem,
					    re_string_t *regexp,
					    re_token_t *token, int token_len,
					    re_dfa_t *dfa,
					    reg_syntax_t syntax,
					    bool accept_hyphen);
static reg_errcode_t parse_bracket_symbol (bracket_elem_t *elem,
					  re_string_t *regexp,
					  re_token_t *token);
#ifdef RE_ENABLE_I18N
static reg_errcode_t build_equiv_class (bitset_t sbcset,
					re_charset_t *mbcset,
					Idx *equiv_class_alloc,
					const unsigned char *name);
static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans,
				      bitset_t sbcset,
				      re_charset_t *mbcset,
				      Idx *char_class_alloc,
				      const char *class_name,
				      reg_syntax_t syntax);
#else  /* not RE_ENABLE_I18N */
static reg_errcode_t build_equiv_class (bitset_t sbcset,
					const unsigned char *name);
static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans,
				      bitset_t sbcset,
				      const char *class_name,
				      reg_syntax_t syntax);
#endif /* not RE_ENABLE_I18N */
static bin_tree_t *build_charclass_op (re_dfa_t *dfa,
				       RE_TRANSLATE_TYPE trans,
				       const char *class_name,
				       const char *extra,
				       bool non_match, reg_errcode_t *err);
static bin_tree_t *create_tree (re_dfa_t *dfa,
				bin_tree_t *left, bin_tree_t *right,
				re_token_type_t type);
static bin_tree_t *create_token_tree (re_dfa_t *dfa,
				      bin_tree_t *left, bin_tree_t *right,
				      const re_token_t *token);
static bin_tree_t *duplicate_tree (const bin_tree_t *src, re_dfa_t *dfa);
static void free_token (re_token_t *node);
static reg_errcode_t free_tree (void *extra, bin_tree_t *node);
static reg_errcode_t mark_opt_subexp (void *extra, bin_tree_t *node);

/* This table gives an error message for each of the error codes listed
   in 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[] =
  {
#define REG_NOERROR_IDX	0
    gettext_noop ("Success")	/* REG_NOERROR */
    "\0"
#define REG_NOMATCH_IDX (REG_NOERROR_IDX + sizeof "Success")
    gettext_noop ("No match")	/* REG_NOMATCH */
    "\0"
#define REG_BADPAT_IDX	(REG_NOMATCH_IDX + sizeof "No match")
    gettext_noop ("Invalid regular expression") /* REG_BADPAT */
    "\0"
#define REG_ECOLLATE_IDX (REG_BADPAT_IDX + sizeof "Invalid regular expression")
    gettext_noop ("Invalid collation character") /* REG_ECOLLATE */
    "\0"
#define REG_ECTYPE_IDX	(REG_ECOLLATE_IDX + sizeof "Invalid collation character")
    gettext_noop ("Invalid character class name") /* REG_ECTYPE */
    "\0"
#define REG_EESCAPE_IDX	(REG_ECTYPE_IDX + sizeof "Invalid character class name")
    gettext_noop ("Trailing backslash") /* REG_EESCAPE */
    "\0"
#define REG_ESUBREG_IDX	(REG_EESCAPE_IDX + sizeof "Trailing backslash")
    gettext_noop ("Invalid back reference") /* REG_ESUBREG */
    "\0"
#define REG_EBRACK_IDX	(REG_ESUBREG_IDX + sizeof "Invalid back reference")
    gettext_noop ("Unmatched [, [^, [:, [., or [=")	/* REG_EBRACK */
    "\0"
#define REG_EPAREN_IDX	(REG_EBRACK_IDX + sizeof "Unmatched [, [^, [:, [., or [=")
    gettext_noop ("Unmatched ( or \\(") /* REG_EPAREN */
    "\0"
#define REG_EBRACE_IDX	(REG_EPAREN_IDX + sizeof "Unmatched ( or \\(")
    gettext_noop ("Unmatched \\{") /* REG_EBRACE */
    "\0"
#define REG_BADBR_IDX	(REG_EBRACE_IDX + sizeof "Unmatched \\{")
    gettext_noop ("Invalid content of \\{\\}") /* REG_BADBR */
    "\0"
#define REG_ERANGE_IDX	(REG_BADBR_IDX + sizeof "Invalid content of \\{\\}")
    gettext_noop ("Invalid range end")	/* REG_ERANGE */
    "\0"
#define REG_ESPACE_IDX	(REG_ERANGE_IDX + sizeof "Invalid range end")
    gettext_noop ("Memory exhausted") /* REG_ESPACE */
    "\0"
#define REG_BADRPT_IDX	(REG_ESPACE_IDX + sizeof "Memory exhausted")
    gettext_noop ("Invalid preceding regular expression") /* REG_BADRPT */
    "\0"
#define REG_EEND_IDX	(REG_BADRPT_IDX + sizeof "Invalid preceding regular expression")
    gettext_noop ("Premature end of regular expression") /* REG_EEND */
    "\0"
#define REG_ESIZE_IDX	(REG_EEND_IDX + sizeof "Premature end of regular expression")
    gettext_noop ("Regular expression too big") /* REG_ESIZE */
    "\0"
#define REG_ERPAREN_IDX	(REG_ESIZE_IDX + sizeof "Regular expression too big")
    gettext_noop ("Unmatched ) or \\)") /* REG_ERPAREN */
  };

static const size_t __re_error_msgid_idx[] =
  {
    REG_NOERROR_IDX,
    REG_NOMATCH_IDX,
    REG_BADPAT_IDX,
    REG_ECOLLATE_IDX,
    REG_ECTYPE_IDX,
    REG_EESCAPE_IDX,
    REG_ESUBREG_IDX,
    REG_EBRACK_IDX,
    REG_EPAREN_IDX,
    REG_EBRACE_IDX,
    REG_BADBR_IDX,
    REG_ERANGE_IDX,
    REG_ESPACE_IDX,
    REG_BADRPT_IDX,
    REG_EEND_IDX,
    REG_ESIZE_IDX,
    REG_ERPAREN_IDX
  };

/* Entry points for GNU code.  */

/* re_compile_pattern is the GNU regular expression compiler: it
   compiles PATTERN (of length LENGTH) and puts the result in BUFP.
   Returns 0 if the pattern was valid, otherwise an error string.

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

const char *
re_compile_pattern (const char *pattern, size_t length,
		    struct re_pattern_buffer *bufp)
{
  reg_errcode_t ret;

  /* And GNU code determines whether or not to get register information
     by passing null for the REGS argument to re_match, etc., not by
     setting no_sub, unless RE_NO_SUB is set.  */
  bufp->no_sub = !!(re_syntax_options & RE_NO_SUB);

  /* Match anchors at newline.  */
  bufp->newline_anchor = 1;

  ret = re_compile_internal (bufp, pattern, length, re_syntax_options);

  if (!ret)
    return NULL;
  return gettext (__re_error_msgid + __re_error_msgid_idx[(int) ret]);
}
weak_alias (__re_compile_pattern, re_compile_pattern)

/* 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 regex.h.  We return the old syntax.  */

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

  re_syntax_options = syntax;
  return ret;
}
weak_alias (__re_set_syntax, re_set_syntax)

int
re_compile_fastmap (struct re_pattern_buffer *bufp)
{
  re_dfa_t *dfa = bufp->buffer;
  char *fastmap = bufp->fastmap;

  memset (fastmap, '\0', sizeof (char) * SBC_MAX);
  re_compile_fastmap_iter (bufp, dfa->init_state, fastmap);
  if (dfa->init_state != dfa->init_state_word)
    re_compile_fastmap_iter (bufp, dfa->init_state_word, fastmap);
  if (dfa->init_state != dfa->init_state_nl)
    re_compile_fastmap_iter (bufp, dfa->init_state_nl, fastmap);
  if (dfa->init_state != dfa->init_state_begbuf)
    re_compile_fastmap_iter (bufp, dfa->init_state_begbuf, fastmap);
  bufp->fastmap_accurate = 1;
  return 0;
}
weak_alias (__re_compile_fastmap, re_compile_fastmap)

static inline void
__attribute__ ((always_inline))
re_set_fastmap (char *fastmap, bool icase, int ch)
{
  fastmap[ch] = 1;
  if (icase)
    fastmap[tolower (ch)] = 1;
}

/* Helper function for re_compile_fastmap.
   Compile fastmap for the initial_state INIT_STATE.  */

static void
re_compile_fastmap_iter (regex_t *bufp, const re_dfastate_t *init_state,
			 char *fastmap)
{
  re_dfa_t *dfa = bufp->buffer;
  Idx node_cnt;
  bool icase = (dfa->mb_cur_max == 1 && (bufp->syntax & RE_ICASE));
  for (node_cnt = 0; node_cnt < init_state->nodes.nelem; ++node_cnt)
    {
      Idx node = init_state->nodes.elems[node_cnt];
      re_token_type_t type = dfa->nodes[node].type;

      if (type == CHARACTER)
	{
	  re_set_fastmap (fastmap, icase, dfa->nodes[node].opr.c);
#ifdef RE_ENABLE_I18N
	  if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1)
	    {
	      unsigned char buf[MB_LEN_MAX];
	      unsigned char *p;
	      wchar_t wc;
	      mbstate_t state;

	      p = buf;
	      *p++ = dfa->nodes[node].opr.c;
	      while (++node < dfa->nodes_len
		     &&	dfa->nodes[node].type == CHARACTER
		     && dfa->nodes[node].mb_partial)
		*p++ = dfa->nodes[node].opr.c;
	      memset (&state, '\0', sizeof (state));
	      if (__mbrtowc (&wc, (const char *) buf, p - buf,
			     &state) == p - buf
		  && (__wcrtomb ((char *) buf, __towlower (wc), &state)
		      != (size_t) -1))
		re_set_fastmap (fastmap, false, buf[0]);
	    }
#endif
	}
      else if (type == SIMPLE_BRACKET)
	{
	  int i, ch;
	  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
	    {
	      int j;
	      bitset_word_t w = dfa->nodes[node].opr.sbcset[i];
	      for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
		if (w & ((bitset_word_t) 1 << j))
		  re_set_fastmap (fastmap, icase, ch);
	    }
	}
#ifdef RE_ENABLE_I18N
      else if (type == COMPLEX_BRACKET)
	{
	  re_charset_t *cset = dfa->nodes[node].opr.mbcset;
	  Idx i;

# ifdef _LIBC
	  /* See if we have to try all bytes which start multiple collation
	     elements.
	     e.g. In da_DK, we want to catch 'a' since "aa" is a valid
		  collation element, and don't catch 'b' since 'b' is
		  the only collation element which starts from 'b' (and
		  it is caught by SIMPLE_BRACKET).  */
	      if (_NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES) != 0
		  && (cset->ncoll_syms || cset->nranges))
		{
		  const int32_t *table = (const int32_t *)
		    _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
		  for (i = 0; i < SBC_MAX; ++i)
		    if (table[i] < 0)
		      re_set_fastmap (fastmap, icase, i);
		}
# endif /* _LIBC */

	  /* See if we have to start the match at all multibyte characters,
	     i.e. where we would not find an invalid sequence.  This only
	     applies to multibyte character sets; for single byte character
	     sets, the SIMPLE_BRACKET again suffices.  */
	  if (dfa->mb_cur_max > 1
	      && (cset->nchar_classes || cset->non_match || cset->nranges
# ifdef _LIBC
		  || cset->nequiv_classes
# endif /* _LIBC */
		 ))
	    {
	      unsigned char c = 0;
	      do
		{
		  mbstate_t mbs;
		  memset (&mbs, 0, sizeof (mbs));
		  if (__mbrtowc (NULL, (char *) &c, 1, &mbs) == (size_t) -2)
		    re_set_fastmap (fastmap, false, (int) c);
		}
	      while (++c != 0);
	    }

	  else
	    {
	      /* ... Else catch all bytes which can start the mbchars.  */
	      for (i = 0; i < cset->nmbchars; ++i)
		{
		  char buf[256];
		  mbstate_t state;
		  memset (&state, '\0', sizeof (state));
		  if (__wcrtomb (buf, cset->mbchars[i], &state) != (size_t) -1)
		    re_set_fastmap (fastmap, icase, *(unsigned char *) buf);
		  if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1)
		    {
		      if (__wcrtomb (buf, __towlower (cset->mbchars[i]), &state)
			  != (size_t) -1)
			re_set_fastmap (fastmap, false, *(unsigned char *) buf);
		    }
		}
	    }
	}
#endif /* RE_ENABLE_I18N */
      else if (type == OP_PERIOD
#ifdef RE_ENABLE_I18N
	       || type == OP_UTF8_PERIOD
#endif /* RE_ENABLE_I18N */
	       || type == END_OF_RE)
	{
	  memset (fastmap, '\1', sizeof (char) * SBC_MAX);
	  if (type == END_OF_RE)
	    bufp->can_be_null = 1;
	  return;
	}
    }
}

/* Entry point for POSIX code.  */
/* regcomp takes a regular expression as a string and compiles it.

   PREG is a regex_t *.  We do not expect any fields to be initialized,
   since POSIX says we shouldn't.  Thus, we set

     'buffer' to the compiled pattern;
     'used' to the length of the compiled pattern;
     'syntax' to RE_SYNTAX_POSIX_EXTENDED if the
       REG_EXTENDED bit in CFLAGS is set; otherwise, to
       RE_SYNTAX_POSIX_BASIC;
     'newline_anchor' to REG_NEWLINE being set in CFLAGS;
     'fastmap' to an allocated space for the fastmap;
     'fastmap_accurate' to zero;
     're_nsub' to the number of subexpressions in PATTERN.

   PATTERN is the address of the pattern string.

   CFLAGS is a series of bits which affect compilation.

     If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
     use POSIX basic syntax.

     If REG_NEWLINE is set, then . and [^...] don't match newline.
     Also, regexec will try a match beginning after every newline.

     If REG_ICASE is set, then we considers upper- and lowercase
     versions of letters to be equivalent when matching.

     If REG_NOSUB is set, then when PREG is passed to regexec, that
     routine will report only success or failure, and nothing about the
     registers.

   It returns 0 if it succeeds, nonzero if it doesn't.  (See regex.h for
   the return codes and their meanings.)  */

int
regcomp (regex_t *__restrict preg, const char *__restrict pattern, int cflags)
{
  reg_errcode_t ret;
  reg_syntax_t syntax = ((cflags & REG_EXTENDED) ? RE_SYNTAX_POSIX_EXTENDED
			 : RE_SYNTAX_POSIX_BASIC);

  preg->buffer = NULL;
  preg->allocated = 0;
  preg->used = 0;

  /* Try to allocate space for the fastmap.  */
  preg->fastmap = re_malloc (char, SBC_MAX);
  if (__glibc_unlikely (preg->fastmap == NULL))
    return REG_ESPACE;

  syntax |= (cflags & REG_ICASE) ? RE_ICASE : 0;

  /* If REG_NEWLINE is set, newlines are treated differently.  */
  if (cflags & REG_NEWLINE)
    { /* REG_NEWLINE implies neither . nor [^...] match newline.  */
      syntax &= ~RE_DOT_NEWLINE;
      syntax |= RE_HAT_LISTS_NOT_NEWLINE;
      /* It also changes the matching behavior.  */
      preg->newline_anchor = 1;
    }
  else
    preg->newline_anchor = 0;
  preg->no_sub = !!(cflags & REG_NOSUB);
  preg->translate = NULL;

  ret = re_compile_internal (preg, pattern, strlen (pattern), syntax);

  /* POSIX doesn't distinguish between an unmatched open-group and an
     unmatched close-group: both are REG_EPAREN.  */
  if (ret == REG_ERPAREN)
    ret = REG_EPAREN;

  /* We have already checked preg->fastmap != NULL.  */
  if (__glibc_likely (ret == REG_NOERROR))
    /* Compute the fastmap now, since regexec cannot modify the pattern
       buffer.  This function never fails in this implementation.  */
    (void) re_compile_fastmap (preg);
  else
    {
      /* Some error occurred while compiling the expression.  */
      re_free (preg->fastmap);
      preg->fastmap = NULL;
    }

  return (int) ret;
}
libc_hidden_def (__regcomp)
weak_alias (__regcomp, regcomp)

/* Returns a message corresponding to an error code, ERRCODE, returned
   from either regcomp or regexec.   We don't use PREG here.  */

size_t
regerror (int errcode, const regex_t *__restrict preg, char *__restrict errbuf,
	  size_t errbuf_size)
{
  const char *msg;
  size_t msg_size;
  int nerrcodes = sizeof __re_error_msgid_idx / sizeof __re_error_msgid_idx[0];

  if (__glibc_unlikely (errcode < 0 || errcode >= nerrcodes))
    /* Only error codes returned by the rest of the code should be passed
       to this routine.  If we are given anything else, or if other regex
       code generates an invalid error code, then the program has a bug.
       Dump core so we can fix it.  */
    abort ();

  msg = gettext (__re_error_msgid + __re_error_msgid_idx[errcode]);

  msg_size = strlen (msg) + 1; /* Includes the null.  */

  if (__glibc_likely (errbuf_size != 0))
    {
      size_t cpy_size = msg_size;
      if (__glibc_unlikely (msg_size > errbuf_size))
	{
	  cpy_size = errbuf_size - 1;
	  errbuf[cpy_size] = '\0';
	}
      memcpy (errbuf, msg, cpy_size);
    }

  return msg_size;
}
weak_alias (__regerror, regerror)


#ifdef RE_ENABLE_I18N
/* This static array is used for the map to single-byte characters when
   UTF-8 is used.  Otherwise we would allocate memory just to initialize
   it the same all the time.  UTF-8 is the preferred encoding so this is
   a worthwhile optimization.  */
static const bitset_t utf8_sb_map =
{
  /* Set the first 128 bits.  */
# if defined __GNUC__ && !defined __STRICT_ANSI__
  [0 ... 0x80 / BITSET_WORD_BITS - 1] = BITSET_WORD_MAX
# else
#  if 4 * BITSET_WORD_BITS < ASCII_CHARS
#   error "bitset_word_t is narrower than 32 bits"
#  elif 3 * BITSET_WORD_BITS < ASCII_CHARS
  BITSET_WORD_MAX, BITSET_WORD_MAX, BITSET_WORD_MAX,
#  elif 2 * BITSET_WORD_BITS < ASCII_CHARS
  BITSET_WORD_MAX, BITSET_WORD_MAX,
#  elif 1 * BITSET_WORD_BITS < ASCII_CHARS
  BITSET_WORD_MAX,
#  endif
  (BITSET_WORD_MAX
   >> (SBC_MAX % BITSET_WORD_BITS == 0
       ? 0
       : BITSET_WORD_BITS - SBC_MAX % BITSET_WORD_BITS))
# endif
};
#endif


static void
free_dfa_content (re_dfa_t *dfa)
{
  Idx i, j;

  if (dfa->nodes)
    for (i = 0; i < dfa->nodes_len; ++i)
      free_token (dfa->nodes + i);
  re_free (dfa->nexts);
  for (i = 0; i < dfa->nodes_len; ++i)
    {
      if (dfa->eclosures != NULL)
	re_node_set_free (dfa->eclosures + i);
      if (dfa->inveclosures != NULL)
	re_node_set_free (dfa->inveclosures + i);
      if (dfa->edests != NULL)
	re_node_set_free (dfa->edests + i);
    }
  re_free (dfa->edests);
  re_free (dfa->eclosures);
  re_free (dfa->inveclosures);
  re_free (dfa->nodes);

  if (dfa->state_table)
    for (i = 0; i <= dfa->state_hash_mask; ++i)
      {
	struct re_state_table_entry *entry = dfa->state_table + i;
	for (j = 0; j < entry->num; ++j)
	  {
	    re_dfastate_t *state = entry->array[j];
	    free_state (state);
	  }
	re_free (entry->array);
      }
  re_free (dfa->state_table);
#ifdef RE_ENABLE_I18N
  if (dfa->sb_char != utf8_sb_map)
    re_free (dfa->sb_char);
#endif
  re_free (dfa->subexp_map);
#ifdef DEBUG
  re_free (dfa->re_str);
#endif

  re_free (dfa);
}


/* Free dynamically allocated space used by PREG.  */

void
regfree (regex_t *preg)
{
  re_dfa_t *dfa = preg->buffer;
  if (__glibc_likely (dfa != NULL))
    {
      lock_fini (dfa->lock);
      free_dfa_content (dfa);
    }
  preg->buffer = NULL;
  preg->allocated = 0;

  re_free (preg->fastmap);
  preg->fastmap = NULL;

  re_free (preg->translate);
  preg->translate = NULL;
}
libc_hidden_def (__regfree)
weak_alias (__regfree, regfree)

/* Entry points compatible with 4.2 BSD regex library.  We don't define
   them unless specifically requested.  */

#if defined _REGEX_RE_COMP || defined _LIBC

/* BSD has one and only one pattern buffer.  */
static struct re_pattern_buffer re_comp_buf;

char *
# ifdef _LIBC
/* Make these definitions weak in libc, so POSIX programs can redefine
   these names if they don't use our functions, and still use
   regcomp/regexec above without link errors.  */
weak_function
# endif
re_comp (const char *s)
{
  reg_errcode_t ret;
  char *fastmap;

  if (!s)
    {
      if (!re_comp_buf.buffer)
	return gettext ("No previous regular expression");
      return 0;
    }

  if (re_comp_buf.buffer)
    {
      fastmap = re_comp_buf.fastmap;
      re_comp_buf.fastmap = NULL;
      __regfree (&re_comp_buf);
      memset (&re_comp_buf, '\0', sizeof (re_comp_buf));
      re_comp_buf.fastmap = fastmap;
    }

  if (re_comp_buf.fastmap == NULL)
    {
      re_comp_buf.fastmap = re_malloc (char, SBC_MAX);
      if (re_comp_buf.fastmap == NULL)
	return (char *) gettext (__re_error_msgid
				 + __re_error_msgid_idx[(int) REG_ESPACE]);
    }

  /* Since 're_exec' always passes NULL for the 'regs' argument, we
     don't need to initialize the pattern buffer fields which affect it.  */

  /* Match anchors at newlines.  */
  re_comp_buf.newline_anchor = 1;

  ret = re_compile_internal (&re_comp_buf, s, strlen (s), re_syntax_options);

  if (!ret)
    return NULL;

  /* Yes, we're discarding 'const' here if !HAVE_LIBINTL.  */
  return (char *) gettext (__re_error_msgid + __re_error_msgid_idx[(int) ret]);
}

#ifdef _LIBC
libc_freeres_fn (free_mem)
{
  __regfree (&re_comp_buf);
}
#endif

#endif /* _REGEX_RE_COMP */

/* Internal entry point.
   Compile the regular expression PATTERN, whose length is LENGTH.
   SYNTAX indicate regular expression's syntax.  */

static reg_errcode_t
re_compile_internal (regex_t *preg, const char * pattern, size_t length,
		     reg_syntax_t syntax)
{
  reg_errcode_t err = REG_NOERROR;
  re_dfa_t *dfa;
  re_string_t regexp;

  /* Initialize the pattern buffer.  */
  preg->fastmap_accurate = 0;
  preg->syntax = syntax;
  preg->not_bol = preg->not_eol = 0;
  preg->used = 0;
  preg->re_nsub = 0;
  preg->can_be_null = 0;
  preg->regs_allocated = REGS_UNALLOCATED;

  /* Initialize the dfa.  */
  dfa = preg->buffer;
  if (__glibc_unlikely (preg->allocated < sizeof (re_dfa_t)))
    {
      /* 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.  If ->buffer is NULL this
	 is a simple allocation.  */
      dfa = re_realloc (preg->buffer, re_dfa_t, 1);
      if (dfa == NULL)
	return REG_ESPACE;
      preg->allocated = sizeof (re_dfa_t);
      preg->buffer = dfa;
    }
  preg->used = sizeof (re_dfa_t);

  err = init_dfa (dfa, length);
  if (__glibc_unlikely (err == REG_NOERROR && lock_init (dfa->lock) != 0))
    err = REG_ESPACE;
  if (__glibc_unlikely (err != REG_NOERROR))
    {
      free_dfa_content (dfa);
      preg->buffer = NULL;
      preg->allocated = 0;
      return err;
    }
#ifdef DEBUG
  /* Note: length+1 will not overflow since it is checked in init_dfa.  */
  dfa->re_str = re_malloc (char, length + 1);
  strncpy (dfa->re_str, pattern, length + 1);
#endif

  err = re_string_construct (&regexp, pattern, length, preg->translate,
			     (syntax & RE_ICASE) != 0, dfa);
  if (__glibc_unlikely (err != REG_NOERROR))
    {
    re_compile_internal_free_return:
      free_workarea_compile (preg);
      re_string_destruct (&regexp);
      lock_fini (dfa->lock);
      free_dfa_content (dfa);
      preg->buffer = NULL;
      preg->allocated = 0;
      return err;
    }

  /* Parse the regular expression, and build a structure tree.  */
  preg->re_nsub = 0;
  dfa->str_tree = parse (&regexp, preg, syntax, &err);
  if (__glibc_unlikely (dfa->str_tree == NULL))
    goto re_compile_internal_free_return;

  /* Analyze the tree and create the nfa.  */
  err = analyze (preg);
  if (__glibc_unlikely (err != REG_NOERROR))
    goto re_compile_internal_free_return;

#ifdef RE_ENABLE_I18N
  /* If possible, do searching in single byte encoding to speed things up.  */
  if (dfa->is_utf8 && !(syntax & RE_ICASE) && preg->translate == NULL)
    optimize_utf8 (dfa);
#endif

  /* Then create the initial state of the dfa.  */
  err = create_initial_state (dfa);

  /* Release work areas.  */
  free_workarea_compile (preg);
  re_string_destruct (&regexp);

  if (__glibc_unlikely (err != REG_NOERROR))
    {
      lock_fini (dfa->lock);
      free_dfa_content (dfa);
      preg->buffer = NULL;
      preg->allocated = 0;
    }

  return err;
}

/* Initialize DFA.  We use the length of the regular expression PAT_LEN
   as the initial length of some arrays.  */

static reg_errcode_t
init_dfa (re_dfa_t *dfa, size_t pat_len)
{
  __re_size_t table_size;
#ifndef _LIBC
  const char *codeset_name;
#endif
#ifdef RE_ENABLE_I18N
  size_t max_i18n_object_size = MAX (sizeof (wchar_t), sizeof (wctype_t));
#else
  size_t max_i18n_object_size = 0;
#endif
  size_t max_object_size =
    MAX (sizeof (struct re_state_table_entry),
	 MAX (sizeof (re_token_t),
	      MAX (sizeof (re_node_set),
		   MAX (sizeof (regmatch_t),
			max_i18n_object_size))));

  memset (dfa, '\0', sizeof (re_dfa_t));

  /* Force allocation of str_tree_storage the first time.  */
  dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE;

  /* Avoid overflows.  The extra "/ 2" is for the table_size doubling
     calculation below, and for similar doubling calculations
     elsewhere.  And it's <= rather than <, because some of the
     doubling calculations add 1 afterwards.  */
  if (__glibc_unlikely (MIN (IDX_MAX, SIZE_MAX / max_object_size) / 2
			<= pat_len))
    return REG_ESPACE;

  dfa->nodes_alloc = pat_len + 1;
  dfa->nodes = re_malloc (re_token_t, dfa->nodes_alloc);

  /*  table_size = 2 ^ ceil(log pat_len) */
  for (table_size = 1; ; table_size <<= 1)
    if (table_size > pat_len)
      break;

  dfa->state_table = calloc (sizeof (struct re_state_table_entry), table_size);
  dfa->state_hash_mask = table_size - 1;

  dfa->mb_cur_max = MB_CUR_MAX;
#ifdef _LIBC
  if (dfa->mb_cur_max == 6
      && strcmp (_NL_CURRENT (LC_CTYPE, _NL_CTYPE_CODESET_NAME), "UTF-8") == 0)
    dfa->is_utf8 = 1;
  dfa->map_notascii = (_NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_MAP_TO_NONASCII)
		       != 0);
#else
  codeset_name = nl_langinfo (CODESET);
  if ((codeset_name[0] == 'U' || codeset_name[0] == 'u')
      && (codeset_name[1] == 'T' || codeset_name[1] == 't')
      && (codeset_name[2] == 'F' || codeset_name[2] == 'f')
      && strcmp (codeset_name + 3 + (codeset_name[3] == '-'), "8") == 0)
    dfa->is_utf8 = 1;

  /* We check exhaustively in the loop below if this charset is a
     superset of ASCII.  */
  dfa->map_notascii = 0;
#endif

#ifdef RE_ENABLE_I18N
  if (dfa->mb_cur_max > 1)
    {
      if (dfa->is_utf8)
	dfa->sb_char = (re_bitset_ptr_t) utf8_sb_map;
      else
	{
	  int i, j, ch;

	  dfa->sb_char = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
	  if (__glibc_unlikely (dfa->sb_char == NULL))
	    return REG_ESPACE;

	  /* Set the bits corresponding to single byte chars.  */
	  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
	    for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
	      {
		wint_t wch = __btowc (ch);
		if (wch != WEOF)
		  dfa->sb_char[i] |= (bitset_word_t) 1 << j;
# ifndef _LIBC
		if (isascii (ch) && wch != ch)
		  dfa->map_notascii = 1;
# endif
	      }
	}
    }
#endif

  if (__glibc_unlikely (dfa->nodes == NULL || dfa->state_table == NULL))
    return REG_ESPACE;
  return REG_NOERROR;
}

/* Initialize WORD_CHAR table, which indicate which character is
   "word".  In this case "word" means that it is the word construction
   character used by some operators like "\<", "\>", etc.  */

static void
init_word_char (re_dfa_t *dfa)
{
  int i = 0;
  int j;
  int ch = 0;
  dfa->word_ops_used = 1;
  if (__glibc_likely (dfa->map_notascii == 0))
    {
      /* Avoid uint32_t and uint64_t as some non-GCC platforms lack
	 them, an issue when this code is used in Gnulib.  */
      bitset_word_t bits0 = 0x00000000;
      bitset_word_t bits1 = 0x03ff0000;
      bitset_word_t bits2 = 0x87fffffe;
      bitset_word_t bits3 = 0x07fffffe;
      if (BITSET_WORD_BITS == 64)
	{
	  /* Pacify gcc -Woverflow on 32-bit platformns.  */
	  dfa->word_char[0] = bits1 << 31 << 1 | bits0;
	  dfa->word_char[1] = bits3 << 31 << 1 | bits2;
	  i = 2;
	}
      else if (BITSET_WORD_BITS == 32)
	{
	  dfa->word_char[0] = bits0;
	  dfa->word_char[1] = bits1;
	  dfa->word_char[2] = bits2;
	  dfa->word_char[3] = bits3;
	  i = 4;
	}
      else
        goto general_case;
      ch = 128;

      if (__glibc_likely (dfa->is_utf8))
	{
	  memset (&dfa->word_char[i], '\0', (SBC_MAX - ch) / 8);
	  return;
	}
    }

 general_case:
  for (; i < BITSET_WORDS; ++i)
    for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
      if (isalnum (ch) || ch == '_')
	dfa->word_char[i] |= (bitset_word_t) 1 << j;
}

/* Free the work area which are only used while compiling.  */

static void
free_workarea_compile (regex_t *preg)
{
  re_dfa_t *dfa = preg->buffer;
  bin_tree_storage_t *storage, *next;
  for (storage = dfa->str_tree_storage; storage; storage = next)
    {
      next = storage->next;
      re_free (storage);
    }
  dfa->str_tree_storage = NULL;
  dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE;
  dfa->str_tree = NULL;
  re_free (dfa->org_indices);
  dfa->org_indices = NULL;
}

/* Create initial states for all contexts.  */

static reg_errcode_t
create_initial_state (re_dfa_t *dfa)
{
  Idx first, i;
  reg_errcode_t err;
  re_node_set init_nodes;

  /* Initial states have the epsilon closure of the node which is
     the first node of the regular expression.  */
  first = dfa->str_tree->first->node_idx;
  dfa->init_node = first;
  err = re_node_set_init_copy (&init_nodes, dfa->eclosures + first);
  if (__glibc_unlikely (err != REG_NOERROR))
    return err;

  /* The back-references which are in initial states can epsilon transit,
     since in this case all of the subexpressions can be null.
     Then we add epsilon closures of the nodes which are the next nodes of
     the back-references.  */
  if (dfa->nbackref > 0)
    for (i = 0; i < init_nodes.nelem; ++i)
      {
	Idx node_idx = init_nodes.elems[i];
	re_token_type_t type = dfa->nodes[node_idx].type;

	Idx clexp_idx;
	if (type != OP_BACK_REF)
	  continue;
	for (clexp_idx = 0; clexp_idx < init_nodes.nelem; ++clexp_idx)
	  {
	    re_token_t *clexp_node;
	    clexp_node = dfa->nodes + init_nodes.elems[clexp_idx];
	    if (clexp_node->type == OP_CLOSE_SUBEXP
		&& clexp_node->opr.idx == dfa->nodes[node_idx].opr.idx)
	      break;
	  }
	if (clexp_idx == init_nodes.nelem)
	  continue;

	if (type == OP_BACK_REF)
	  {
	    Idx dest_idx = dfa->edests[node_idx].elems[0];
	    if (!re_node_set_contains (&init_nodes, dest_idx))
	      {
		reg_errcode_t merge_err
                  = re_node_set_merge (&init_nodes, dfa->eclosures + dest_idx);
		if (merge_err != REG_NOERROR)
		  return merge_err;
		i = 0;
	      }
	  }
      }

  /* It must be the first time to invoke acquire_state.  */
  dfa->init_state = re_acquire_state_context (&err, dfa, &init_nodes, 0);
  /* We don't check ERR here, since the initial state must not be NULL.  */
  if (__glibc_unlikely (dfa->init_state == NULL))
    return err;
  if (dfa->init_state->has_constraint)
    {
      dfa->init_state_word = re_acquire_state_context (&err, dfa, &init_nodes,
						       CONTEXT_WORD);
      dfa->init_state_nl = re_acquire_state_context (&err, dfa, &init_nodes,
						     CONTEXT_NEWLINE);
      dfa->init_state_begbuf = re_acquire_state_context (&err, dfa,
							 &init_nodes,
							 CONTEXT_NEWLINE
							 | CONTEXT_BEGBUF);
      if (__glibc_unlikely (dfa->init_state_word == NULL
			    || dfa->init_state_nl == NULL
			    || dfa->init_state_begbuf == NULL))
	return err;
    }
  else
    dfa->init_state_word = dfa->init_state_nl
      = dfa->init_state_begbuf = dfa->init_state;

  re_node_set_free (&init_nodes);
  return REG_NOERROR;
}

#ifdef RE_ENABLE_I18N
/* If it is possible to do searching in single byte encoding instead of UTF-8
   to speed things up, set dfa->mb_cur_max to 1, clear is_utf8 and change
   DFA nodes where needed.  */

static void
optimize_utf8 (re_dfa_t *dfa)
{
  Idx node;
  int i;
  bool mb_chars = false;
  bool has_period = false;

  for (node = 0; node < dfa->nodes_len; ++node)
    switch (dfa->nodes[node].type)
      {
      case CHARACTER:
	if (dfa->nodes[node].opr.c >= ASCII_CHARS)
	  mb_chars = true;
	break;
      case ANCHOR:
	switch (dfa->nodes[node].opr.ctx_type)
	  {
	  case LINE_FIRST:
	  case LINE_LAST:
	  case BUF_FIRST:
	  case BUF_LAST:
	    break;
	  default:
	    /* Word anchors etc. cannot be handled.  It's okay to test
	       opr.ctx_type since constraints (for all DFA nodes) are
	       created by ORing one or more opr.ctx_type values.  */
	    return;
	  }
	break;
      case OP_PERIOD:
	has_period = true;
	break;
      case OP_BACK_REF:
      case OP_ALT:
      case END_OF_RE:
      case OP_DUP_ASTERISK:
      case OP_OPEN_SUBEXP:
      case OP_CLOSE_SUBEXP:
	break;
      case COMPLEX_BRACKET:
	return;
      case SIMPLE_BRACKET:
	/* Just double check.  */
	{
	  int rshift = (ASCII_CHARS % BITSET_WORD_BITS == 0
			? 0
			: BITSET_WORD_BITS - ASCII_CHARS % BITSET_WORD_BITS);
	  for (i = ASCII_CHARS / BITSET_WORD_BITS; i < BITSET_WORDS; ++i)
	    {
	      if (dfa->nodes[node].opr.sbcset[i] >> rshift != 0)
		return;
	      rshift = 0;
	    }
	}
	break;
      default:
	abort ();
      }

  if (mb_chars || has_period)
    for (node = 0; node < dfa->nodes_len; ++node)
      {
	if (dfa->nodes[node].type == CHARACTER
	    && dfa->nodes[node].opr.c >= ASCII_CHARS)
	  dfa->nodes[node].mb_partial = 0;
	else if (dfa->nodes[node].type == OP_PERIOD)
	  dfa->nodes[node].type = OP_UTF8_PERIOD;
      }

  /* The search can be in single byte locale.  */
  dfa->mb_cur_max = 1;
  dfa->is_utf8 = 0;
  dfa->has_mb_node = dfa->nbackref > 0 || has_period;
}
#endif

/* Analyze the structure tree, and calculate "first", "next", "edest",
   "eclosure", and "inveclosure".  */

static reg_errcode_t
analyze (regex_t *preg)
{
  re_dfa_t *dfa = preg->buffer;
  reg_errcode_t ret;

  /* Allocate arrays.  */
  dfa->nexts = re_malloc (Idx, dfa->nodes_alloc);
  dfa->org_indices = re_malloc (Idx, dfa->nodes_alloc);
  dfa->edests = re_malloc (re_node_set, dfa->nodes_alloc);
  dfa->eclosures = re_malloc (re_node_set, dfa->nodes_alloc);
  if (__glibc_unlikely (dfa->nexts == NULL || dfa->org_indices == NULL
			|| dfa->edests == NULL || dfa->eclosures == NULL))
    return REG_ESPACE;

  dfa->subexp_map = re_malloc (Idx, preg->re_nsub);
  if (dfa->subexp_map != NULL)
    {
      Idx i;
      for (i = 0; i < preg->re_nsub; i++)
	dfa->subexp_map[i] = i;
      preorder (dfa->str_tree, optimize_subexps, dfa);
      for (i = 0; i < preg->re_nsub; i++)
	if (dfa->subexp_map[i] != i)
	  break;
      if (i == preg->re_nsub)
	{
	  re_free (dfa->subexp_map);
	  dfa->subexp_map = NULL;
	}
    }

  ret = postorder (dfa->str_tree, lower_subexps, preg);
  if (__glibc_unlikely (ret != REG_NOERROR))
    return ret;
  ret = postorder (dfa->str_tree, calc_first, dfa);
  if (__glibc_unlikely (ret != REG_NOERROR))
    return ret;
  preorder (dfa->str_tree, calc_next, dfa);
  ret = preorder (dfa->str_tree, link_nfa_nodes, dfa);
  if (__glibc_unlikely (ret != REG_NOERROR))
    return ret;
  ret = calc_eclosure (dfa);
  if (__glibc_unlikely (ret != REG_NOERROR))
    return ret;

  /* We only need this during the prune_impossible_nodes pass in regexec.c;
     skip it if p_i_n will not run, as calc_inveclosure can be quadratic.  */
  if ((!preg->no_sub && preg->re_nsub > 0 && dfa->has_plural_match)
      || dfa->nbackref)
    {
      dfa->inveclosures = re_malloc (re_node_set, dfa->nodes_len);
      if (__glibc_unlikely (dfa->inveclosures == NULL))
	return REG_ESPACE;
      ret = calc_inveclosure (dfa);
    }

  return ret;
}

/* Our parse trees are very unbalanced, so we cannot use a stack to
   implement parse tree visits.  Instead, we use parent pointers and
   some hairy code in these two functions.  */
static reg_errcode_t
postorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)),
	   void *extra)
{
  bin_tree_t *node, *prev;

  for (node = root; ; )
    {
      /* Descend down the tree, preferably to the left (or to the right
	 if that's the only child).  */
      while (node->left || node->right)
	if (node->left)
	  node = node->left;
	else
	  node = node->right;

      do
	{
	  reg_errcode_t err = fn (extra, node);
	  if (__glibc_unlikely (err != REG_NOERROR))
	    return err;
	  if (node->parent == NULL)
	    return REG_NOERROR;
	  prev = node;
	  node = node->parent;
	}
      /* Go up while we have a node that is reached from the right.  */
      while (node->right == prev || node->right == NULL);
      node = node->right;
    }
}

static reg_errcode_t
preorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)),
	  void *extra)
{
  bin_tree_t *node;

  for (node = root; ; )
    {
      reg_errcode_t err = fn (extra, node);
      if (__glibc_unlikely (err != REG_NOERROR))
	return err;

      /* Go to the left node, or up and to the right.  */
      if (node->left)
	node = node->left;
      else
	{
	  bin_tree_t *prev = NULL;
	  while (node->right == prev || node->right == NULL)
	    {
	      prev = node;
	      node = node->parent;
	      if (!node)
		return REG_NOERROR;
	    }
	  node = node->right;
	}
    }
}

/* Optimization pass: if a SUBEXP is entirely contained, strip it and tell
   re_search_internal to map the inner one's opr.idx to this one's.  Adjust
   backreferences as well.  Requires a preorder visit.  */
static reg_errcode_t
optimize_subexps (void *extra, bin_tree_t *node)
{
  re_dfa_t *dfa = (re_dfa_t *) extra;

  if (node->token.type == OP_BACK_REF && dfa->subexp_map)
    {
      int idx = node->token.opr.idx;
      node->token.opr.idx = dfa->subexp_map[idx];
      dfa->used_bkref_map |= 1 << node->token.opr.idx;
    }

  else if (node->token.type == SUBEXP
	   && node->left && node->left->token.type == SUBEXP)
    {
      Idx other_idx = node->left->token.opr.idx;

      node->left = node->left->left;
      if (node->left)
	node->left->parent = node;

      dfa->subexp_map[other_idx] = dfa->subexp_map[node->token.opr.idx];
      if (other_idx < BITSET_WORD_BITS)
	dfa->used_bkref_map &= ~((bitset_word_t) 1 << other_idx);
    }

  return REG_NOERROR;
}

/* Lowering pass: Turn each SUBEXP node into the appropriate concatenation
   of OP_OPEN_SUBEXP, the body of the SUBEXP (if any) and OP_CLOSE_SUBEXP.  */
static reg_errcode_t
lower_subexps (void *extra, bin_tree_t *node)
{
  regex_t *preg = (regex_t *) extra;
  reg_errcode_t err = REG_NOERROR;

  if (node->left && node->left->token.type == SUBEXP)
    {
      node->left = lower_subexp (&err, preg, node->left);
      if (node->left)
	node->left->parent = node;
    }
  if (node->right && node->right->token.type == SUBEXP)
    {
      node->right = lower_subexp (&err, preg, node->right);
      if (node->right)
	node->right->parent = node;
    }

  return err;
}

static bin_tree_t *
lower_subexp (reg_errcode_t *err, regex_t *preg, bin_tree_t *node)
{
  re_dfa_t *dfa = preg->buffer;
  bin_tree_t *body = node->left;
  bin_tree_t *op, *cls, *tree1, *tree;

  if (preg->no_sub
      /* We do not optimize empty subexpressions, because otherwise we may
	 have bad CONCAT nodes with NULL children.  This is obviously not
	 very common, so we do not lose much.  An example that triggers
	 this case is the sed "script" /\(\)/x.  */
      && node->left != NULL
      && (node->token.opr.idx >= BITSET_WORD_BITS
	  || !(dfa->used_bkref_map
	       & ((bitset_word_t) 1 << node->token.opr.idx))))
    return node->left;

  /* Convert the SUBEXP node to the concatenation of an
     OP_OPEN_SUBEXP, the contents, and an OP_CLOSE_SUBEXP.  */
  op = create_tree (dfa, NULL, NULL, OP_OPEN_SUBEXP);
  cls = create_tree (dfa, NULL, NULL, OP_CLOSE_SUBEXP);
  tree1 = body ? create_tree (dfa, body, cls, CONCAT) : cls;
  tree = create_tree (dfa, op, tree1, CONCAT);
  if (__glibc_unlikely (tree == NULL || tree1 == NULL
			|| op == NULL || cls == NULL))
    {
      *err = REG_ESPACE;
      return NULL;
    }

  op->token.opr.idx = cls->token.opr.idx = node->token.opr.idx;
  op->token.opt_subexp = cls->token.opt_subexp = node->token.opt_subexp;
  return tree;
}

/* Pass 1 in building the NFA: compute FIRST and create unlinked automaton
   nodes.  Requires a postorder visit.  */
static reg_errcode_t
calc_first (void *extra, bin_tree_t *node)
{
  re_dfa_t *dfa = (re_dfa_t *) extra;
  if (node->token.type == CONCAT)
    {
      node->first = node->left->first;
      node->node_idx = node->left->node_idx;
    }
  else
    {
      node->first = node;
      node->node_idx = re_dfa_add_node (dfa, node->token);
      if (__glibc_unlikely (node->node_idx == -1))
	return REG_ESPACE;
      if (node->token.type == ANCHOR)
	dfa->nodes[node->node_idx].constraint = node->token.opr.ctx_type;
    }
  return REG_NOERROR;
}

/* Pass 2: compute NEXT on the tree.  Preorder visit.  */
static reg_errcode_t
calc_next (void *extra, bin_tree_t *node)
{
  switch (node->token.type)
    {
    case OP_DUP_ASTERISK:
      node->left->next = node;
      break;
    case CONCAT:
      node->left->next = node->right->first;
      node->right->next = node->next;
      break;
    default:
      if (node->left)
	node->left->next = node->next;
      if (node->right)
	node->right->next = node->next;
      break;
    }
  return REG_NOERROR;
}

/* Pass 3: link all DFA nodes to their NEXT node (any order will do).  */
static reg_errcode_t
link_nfa_nodes (void *extra, bin_tree_t *node)
{
  re_dfa_t *dfa = (re_dfa_t *) extra;
  Idx idx = node->node_idx;
  reg_errcode_t err = REG_NOERROR;

  switch (node->token.type)
    {
    case CONCAT:
      break;

    case END_OF_RE:
      DEBUG_ASSERT (node->next == NULL);
      break;

    case OP_DUP_ASTERISK:
    case OP_ALT:
      {
	Idx left, right;
	dfa->has_plural_match = 1;
	if (node->left != NULL)
	  left = node->left->first->node_idx;
	else
	  left = node->next->node_idx;
	if (node->right != NULL)
	  right = node->right->first->node_idx;
	else
	  right = node->next->node_idx;
	DEBUG_ASSERT (left > -1);
	DEBUG_ASSERT (right > -1);
	err = re_node_set_init_2 (dfa->edests + idx, left, right);
      }
      break;

    case ANCHOR:
    case OP_OPEN_SUBEXP:
    case OP_CLOSE_SUBEXP:
      err = re_node_set_init_1 (dfa->edests + idx, node->next->node_idx);
      break;

    case OP_BACK_REF:
      dfa->nexts[idx] = node->next->node_idx;
      if (node->token.type == OP_BACK_REF)
	err = re_node_set_init_1 (dfa->edests + idx, dfa->nexts[idx]);
      break;

    default:
      DEBUG_ASSERT (!IS_EPSILON_NODE (node->token.type));
      dfa->nexts[idx] = node->next->node_idx;
      break;
    }

  return err;
}

/* Duplicate the epsilon closure of the node ROOT_NODE.
   Note that duplicated nodes have constraint INIT_CONSTRAINT in addition
   to their own constraint.  */

static reg_errcode_t
duplicate_node_closure (re_dfa_t *dfa, Idx top_org_node, Idx top_clone_node,
			Idx root_node, unsigned int init_constraint)
{
  Idx org_node, clone_node;
  bool ok;
  unsigned int constraint = init_constraint;
  for (org_node = top_org_node, clone_node = top_clone_node;;)
    {
      Idx org_dest, clone_dest;
      if (dfa->nodes[org_node].type == OP_BACK_REF)
	{
	  /* If the back reference epsilon-transit, its destination must
	     also have the constraint.  Then duplicate the epsilon closure
	     of the destination of the back reference, and store it in
	     edests of the back reference.  */
	  org_dest = dfa->nexts[org_node];
	  re_node_set_empty (dfa->edests + clone_node);
	  clone_dest = duplicate_node (dfa, org_dest, constraint);
	  if (__glibc_unlikely (clone_dest == -1))
	    return REG_ESPACE;
	  dfa->nexts[clone_node] = dfa->nexts[org_node];
	  ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
	  if (__glibc_unlikely (! ok))
	    return REG_ESPACE;
	}
      else if (dfa->edests[org_node].nelem == 0)
	{
	  /* In case of the node can't epsilon-transit, don't duplicate the
	     destination and store the original destination as the
	     destination of the node.  */
	  dfa->nexts[clone_node] = dfa->nexts[org_node];
	  break;
	}
      else if (dfa->edests[org_node].nelem == 1)
	{
	  /* In case of the node can epsilon-transit, and it has only one
	     destination.  */
	  org_dest = dfa->edests[org_node].elems[0];
	  re_node_set_empty (dfa->edests + clone_node);
	  /* If the node is root_node itself, it means the epsilon closure
	     has a loop.  Then tie it to the destination of the root_node.  */
	  if (org_node == root_node && clone_node != org_node)
	    {
	      ok = re_node_set_insert (dfa->edests + clone_node, org_dest);
	      if (__glibc_unlikely (! ok))
	        return REG_ESPACE;
	      break;
	    }
	  /* In case the node has another constraint, append it.  */
	  constraint |= dfa->nodes[org_node].constraint;
	  clone_dest = duplicate_node (dfa, org_dest, constraint);
	  if (__glibc_unlikely (clone_dest == -1))
	    return REG_ESPACE;
	  ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
	  if (__glibc_unlikely (! ok))
	    return REG_ESPACE;
	}
      else /* dfa->edests[org_node].nelem == 2 */
	{
	  /* In case of the node can epsilon-transit, and it has two
	     destinations. In the bin_tree_t and DFA, that's '|' and '*'.   */
	  org_dest = dfa->edests[org_node].elems[0];
	  re_node_set_empty (dfa->edests + clone_node);
	  /* Search for a duplicated node which satisfies the constraint.  */
	  clone_dest = search_duplicated_node (dfa, org_dest, constraint);
	  if (clone_dest == -1)
	    {
	      /* There is no such duplicated node, create a new one.  */
	      reg_errcode_t err;
	      clone_dest = duplicate_node (dfa, org_dest, constraint);
	      if (__glibc_unlikely (clone_dest == -1))
		return REG_ESPACE;
	      ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
	      if (__glibc_unlikely (! ok))
		return REG_ESPACE;
	      err = duplicate_node_closure (dfa, org_dest, clone_dest,
					    root_node, constraint);
	      if (__glibc_unlikely (err != REG_NOERROR))
		return err;
	    }
	  else
	    {
	      /* There is a duplicated node which satisfies the constraint,
		 use it to avoid infinite loop.  */
	      ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
	      if (__glibc_unlikely (! ok))
		return REG_ESPACE;
	    }

	  org_dest = dfa->edests[org_node].elems[1];
	  clone_dest = duplicate_node (dfa, org_dest, constraint);
	  if (__glibc_unlikely (clone_dest == -1))
	    return REG_ESPACE;
	  ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
	  if (__glibc_unlikely (! ok))
	    return REG_ESPACE;
	}
      org_node = org_dest;
      clone_node = clone_dest;
    }
  return REG_NOERROR;
}

/* Search for a node which is duplicated from the node ORG_NODE, and
   satisfies the constraint CONSTRAINT.  */

static Idx
search_duplicated_node (const re_dfa_t *dfa, Idx org_node,
			unsigned int constraint)
{
  Idx idx;
  for (idx = dfa->nodes_len - 1; dfa->nodes[idx].duplicated && idx > 0; --idx)
    {
      if (org_node == dfa->org_indices[idx]
	  && constraint == dfa->nodes[idx].constraint)
	return idx; /* Found.  */
    }
  return -1; /* Not found.  */
}

/* Duplicate the node whose index is ORG_IDX and set the constraint CONSTRAINT.
   Return the index of the new node, or -1 if insufficient storage is
   available.  */

static Idx
duplicate_node (re_dfa_t *dfa, Idx org_idx, unsigned int constraint)
{
  Idx dup_idx = re_dfa_add_node (dfa, dfa->nodes[org_idx]);
  if (__glibc_likely (dup_idx != -1))
    {
      dfa->nodes[dup_idx].constraint = constraint;
      dfa->nodes[dup_idx].constraint |= dfa->nodes[org_idx].constraint;
      dfa->nodes[dup_idx].duplicated = 1;

      /* Store the index of the original node.  */
      dfa->org_indices[dup_idx] = org_idx;
    }
  return dup_idx;
}

static reg_errcode_t
calc_inveclosure (re_dfa_t *dfa)
{
  Idx src, idx;
  bool ok;
  for (idx = 0; idx < dfa->nodes_len; ++idx)
    re_node_set_init_empty (dfa->inveclosures + idx);

  for (src = 0; src < dfa->nodes_len; ++src)
    {
      Idx *elems = dfa->eclosures[src].elems;
      for (idx = 0; idx < dfa->eclosures[src].nelem; ++idx)
	{
	  ok = re_node_set_insert_last (dfa->inveclosures + elems[idx], src);
	  if (__glibc_unlikely (! ok))
	    return REG_ESPACE;
	}
    }

  return REG_NOERROR;
}

/* Calculate "eclosure" for all the node in DFA.  */

static reg_errcode_t
calc_eclosure (re_dfa_t *dfa)
{
  Idx node_idx;
  bool incomplete;
  DEBUG_ASSERT (dfa->nodes_len > 0);
  incomplete = false;
  /* For each nodes, calculate epsilon closure.  */
  for (node_idx = 0; ; ++node_idx)
    {
      reg_errcode_t err;
      re_node_set eclosure_elem;
      if (node_idx == dfa->nodes_len)
	{
	  if (!incomplete)
	    break;
	  incomplete = false;
	  node_idx = 0;
	}

      DEBUG_ASSERT (dfa->eclosures[node_idx].nelem != -1);

      /* If we have already calculated, skip it.  */
      if (dfa->eclosures[node_idx].nelem != 0)
	continue;
      /* Calculate epsilon closure of 'node_idx'.  */
      err = calc_eclosure_iter (&eclosure_elem, dfa, node_idx, true);
      if (__glibc_unlikely (err != REG_NOERROR))
	return err;

      if (dfa->eclosures[node_idx].nelem == 0)
	{
	  incomplete = true;
	  re_node_set_free (&eclosure_elem);
	}
    }
  return REG_NOERROR;
}

/* Calculate epsilon closure of NODE.  */

static reg_errcode_t
calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, Idx node, bool root)
{
  reg_errcode_t err;
  Idx i;
  re_node_set eclosure;
  bool ok;
  bool incomplete = false;
  err = re_node_set_alloc (&eclosure, dfa->edests[node].nelem + 1);
  if (__glibc_unlikely (err != REG_NOERROR))
    return err;

  /* This indicates that we are calculating this node now.
     We reference this value to avoid infinite loop.  */
  dfa->eclosures[node].nelem = -1;

  /* If the current node has constraints, duplicate all nodes
     since they must inherit the constraints.  */
  if (dfa->nodes[node].constraint
      && dfa->edests[node].nelem
      && !dfa->nodes[dfa->edests[node].elems[0]].duplicated)
    {
      err = duplicate_node_closure (dfa, node, node, node,
				    dfa->nodes[node].constraint);
      if (__glibc_unlikely (err != REG_NOERROR))
	return err;
    }

  /* Expand each epsilon destination nodes.  */
  if (IS_EPSILON_NODE(dfa->nodes[node].type))
    for (i = 0; i < dfa->edests[node].nelem; ++i)
      {
	re_node_set eclosure_elem;
	Idx edest = dfa->edests[node].elems[i];
	/* If calculating the epsilon closure of 'edest' is in progress,
	   return intermediate result.  */
	if (dfa->eclosures[edest].nelem == -1)
	  {
	    incomplete = true;
	    continue;
	  }
	/* If we haven't calculated the epsilon closure of 'edest' yet,
	   calculate now. Otherwise use calculated epsilon closure.  */
	if (dfa->eclosures[edest].nelem == 0)
	  {
	    err = calc_eclosure_iter (&eclosure_elem, dfa, edest, false);
	    if (__glibc_unlikely (err != REG_NOERROR))
	      return err;
	  }
	else
	  eclosure_elem = dfa->eclosures[edest];
	/* Merge the epsilon closure of 'edest'.  */
	err = re_node_set_merge (&eclosure, &eclosure_elem);
	if (__glibc_unlikely (err != REG_NOERROR))
	  return err;
	/* If the epsilon closure of 'edest' is incomplete,
	   the epsilon closure of this node is also incomplete.  */
	if (dfa->eclosures[edest].nelem == 0)
	  {
	    incomplete = true;
	    re_node_set_free (&eclosure_elem);
	  }
      }

  /* An epsilon closure includes itself.  */
  ok = re_node_set_insert (&eclosure, node);
  if (__glibc_unlikely (! ok))
    return REG_ESPACE;
  if (incomplete && !root)
    dfa->eclosures[node].nelem = 0;
  else
    dfa->eclosures[node] = eclosure;
  *new_set = eclosure;
  return REG_NOERROR;
}

/* Functions for token which are used in the parser.  */

/* Fetch a token from INPUT.
   We must not use this function inside bracket expressions.  */

static void
fetch_token (re_token_t *result, re_string_t *input, reg_syntax_t syntax)
{
  re_string_skip_bytes (input, peek_token (result, input, syntax));
}

/* Peek a token from INPUT, and return the length of the token.
   We must not use this function inside bracket expressions.  */

static int
peek_token (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
{
  unsigned char c;

  if (re_string_eoi (input))
    {
      token->type = END_OF_RE;
      return 0;
    }

  c = re_string_peek_byte (input, 0);
  token->opr.c = c;

  token->word_char = 0;
#ifdef RE_ENABLE_I18N
  token->mb_partial = 0;
  if (input->mb_cur_max > 1
      && !re_string_first_byte (input, re_string_cur_idx (input)))
    {
      token->type = CHARACTER;
      token->mb_partial = 1;
      return 1;
    }
#endif
  if (c == '\\')
    {
      unsigned char c2;
      if (re_string_cur_idx (input) + 1 >= re_string_length (input))
	{
	  token->type = BACK_SLASH;
	  return 1;
	}

      c2 = re_string_peek_byte_case (input, 1);
      token->opr.c = c2;
      token->type = CHARACTER;
#ifdef RE_ENABLE_I18N
      if (input->mb_cur_max > 1)
	{
	  wint_t wc = re_string_wchar_at (input,
					  re_string_cur_idx (input) + 1);
	  token->word_char = IS_WIDE_WORD_CHAR (wc) != 0;
	}
      else
#endif
	token->word_char = IS_WORD_CHAR (c2) != 0;

      switch (c2)
	{
	case '|':
	  if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_NO_BK_VBAR))
	    token->type = OP_ALT;
	  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))
	    {
	      token->type = OP_BACK_REF;
	      token->opr.idx = c2 - '1';
	    }
	  break;
	case '<':
	  if (!(syntax & RE_NO_GNU_OPS))
	    {
	      token->type = ANCHOR;
	      token->opr.ctx_type = WORD_FIRST;
	    }
	  break;
	case '>':
	  if (!(syntax & RE_NO_GNU_OPS))
	    {
	      token->type = ANCHOR;
	      token->opr.ctx_type = WORD_LAST;
	    }
	  break;
	case 'b':
	  if (!(syntax & RE_NO_GNU_OPS))
	    {
	      token->type = ANCHOR;
	      token->opr.ctx_type = WORD_DELIM;
	    }
	  break;
	case 'B':
	  if (!(syntax & RE_NO_GNU_OPS))
	    {
	      token->type = ANCHOR;
	      token->opr.ctx_type = NOT_WORD_DELIM;
	    }
	  break;
	case 'w':
	  if (!(syntax & RE_NO_GNU_OPS))
	    token->type = OP_WORD;
	  break;
	case 'W':
	  if (!(syntax & RE_NO_GNU_OPS))
	    token->type = OP_NOTWORD;
	  break;
	case 's':
	  if (!(syntax & RE_NO_GNU_OPS))
	    token->type = OP_SPACE;
	  break;
	case 'S':
	  if (!(syntax & RE_NO_GNU_OPS))
	    token->type = OP_NOTSPACE;
	  break;
	case '`':
	  if (!(syntax & RE_NO_GNU_OPS))
	    {
	      token->type = ANCHOR;
	      token->opr.ctx_type = BUF_FIRST;
	    }
	  break;
	case '\'':
	  if (!(syntax & RE_NO_GNU_OPS))
	    {
	      token->type = ANCHOR;
	      token->opr.ctx_type = BUF_LAST;
	    }
	  break;
	case '(':
	  if (!(syntax & RE_NO_BK_PARENS))
	    token->type = OP_OPEN_SUBEXP;
	  break;
	case ')':
	  if (!(syntax & RE_NO_BK_PARENS))
	    token->type = OP_CLOSE_SUBEXP;
	  break;
	case '+':
	  if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_BK_PLUS_QM))
	    token->type = OP_DUP_PLUS;
	  break;
	case '?':
	  if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_BK_PLUS_QM))
	    token->type = OP_DUP_QUESTION;
	  break;
	case '{':
	  if ((syntax & RE_INTERVALS) && (!(syntax & RE_NO_BK_BRACES)))
	    token->type = OP_OPEN_DUP_NUM;
	  break;
	case '}':
	  if ((syntax & RE_INTERVALS) && (!(syntax & RE_NO_BK_BRACES)))
	    token->type = OP_CLOSE_DUP_NUM;
	  break;
	default:
	  break;
	}
      return 2;
    }

  token->type = CHARACTER;
#ifdef RE_ENABLE_I18N
  if (input->mb_cur_max > 1)
    {
      wint_t wc = re_string_wchar_at (input, re_string_cur_idx (input));
      token->word_char = IS_WIDE_WORD_CHAR (wc) != 0;
    }
  else
#endif
    token->word_char = IS_WORD_CHAR (token->opr.c);

  switch (c)
    {
    case '\n':
      if (syntax & RE_NEWLINE_ALT)
	token->type = OP_ALT;
      break;
    case '|':
      if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_NO_BK_VBAR))
	token->type = OP_ALT;
      break;
    case '*':
      token->type = OP_DUP_ASTERISK;
      break;
    case '+':
      if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_BK_PLUS_QM))
	token->type = OP_DUP_PLUS;
      break;
    case '?':
      if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_BK_PLUS_QM))
	token->type = OP_DUP_QUESTION;
      break;
    case '{':
      if ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
	token->type = OP_OPEN_DUP_NUM;
      break;
    case '}':
      if ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
	token->type = OP_CLOSE_DUP_NUM;
      break;
    case '(':
      if (syntax & RE_NO_BK_PARENS)
	token->type = OP_OPEN_SUBEXP;
      break;
    case ')':
      if (syntax & RE_NO_BK_PARENS)
	token->type = OP_CLOSE_SUBEXP;
      break;
    case '[':
      token->type = OP_OPEN_BRACKET;
      break;
    case '.':
      token->type = OP_PERIOD;
      break;
    case '^':
      if (!(syntax & (RE_CONTEXT_INDEP_ANCHORS | RE_CARET_ANCHORS_HERE))
	  && re_string_cur_idx (input) != 0)
	{
	  char prev = re_string_peek_byte (input, -1);
	  if (!(syntax & RE_NEWLINE_ALT) || prev != '\n')
	    break;
	}
      token->type = ANCHOR;
      token->opr.ctx_type = LINE_FIRST;
      break;
    case '$':
      if (!(syntax & RE_CONTEXT_INDEP_ANCHORS)
	  && re_string_cur_idx (input) + 1 != re_string_length (input))
	{
	  re_token_t next;
	  re_string_skip_bytes (input, 1);
	  peek_token (&next, input, syntax);
	  re_string_skip_bytes (input, -1);
	  if (next.type != OP_ALT && next.type != OP_CLOSE_SUBEXP)
	    break;
	}
      token->type = ANCHOR;
      token->opr.ctx_type = LINE_LAST;
      break;
    default:
      break;
    }
  return 1;
}

/* Peek a token from INPUT, and return the length of the token.
   We must not use this function out of bracket expressions.  */

static int
peek_token_bracket (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
{
  unsigned char c;
  if (re_string_eoi (input))
    {
      token->type = END_OF_RE;
      return 0;
    }
  c = re_string_peek_byte (input, 0);
  token->opr.c = c;

#ifdef RE_ENABLE_I18N
  if (input->mb_cur_max > 1
      && !re_string_first_byte (input, re_string_cur_idx (input)))
    {
      token->type = CHARACTER;
      return 1;
    }
#endif /* RE_ENABLE_I18N */

  if (c == '\\' && (syntax & RE_BACKSLASH_ESCAPE_IN_LISTS)
      && re_string_cur_idx (input) + 1 < re_string_length (input))
    {
      /* In this case, '\' escape a character.  */
      unsigned char c2;
      re_string_skip_bytes (input, 1);
      c2 = re_string_peek_byte (input, 0);
      token->opr.c = c2;
      token->type = CHARACTER;
      return 1;
    }
  if (c == '[') /* '[' is a special char in a bracket exps.  */
    {
      unsigned char c2;
      int token_len;
      if (re_string_cur_idx (input) + 1 < re_string_length (input))
	c2 = re_string_peek_byte (input, 1);
      else
	c2 = 0;
      token->opr.c = c2;
      token_len = 2;
      switch (c2)
	{
	case '.':
	  token->type = OP_OPEN_COLL_ELEM;
	  break;

	case '=':
	  token->type = OP_OPEN_EQUIV_CLASS;
	  break;

	case ':':
	  if (syntax & RE_CHAR_CLASSES)
	    {
	      token->type = OP_OPEN_CHAR_CLASS;
	      break;
	    }
	  FALLTHROUGH;
	default:
	  token->type = CHARACTER;
	  token->opr.c = c;
	  token_len = 1;
	  break;
	}
      return token_len;
    }
  switch (c)
    {
    case '-':
      token->type = OP_CHARSET_RANGE;
      break;
    case ']':
      token->type = OP_CLOSE_BRACKET;
      break;
    case '^':
      token->type = OP_NON_MATCH_LIST;
      break;
    default:
      token->type = CHARACTER;
    }
  return 1;
}

/* Functions for parser.  */

/* Entry point of the parser.
   Parse the regular expression REGEXP and return the structure tree.
   If an error occurs, ERR is set by error code, and return NULL.
   This function build the following tree, from regular expression <reg_exp>:
	   CAT
	   / \
	  /   \
   <reg_exp>  EOR

   CAT means concatenation.
   EOR means end of regular expression.  */

static bin_tree_t *
parse (re_string_t *regexp, regex_t *preg, reg_syntax_t syntax,
       reg_errcode_t *err)
{
  re_dfa_t *dfa = preg->buffer;
  bin_tree_t *tree, *eor, *root;
  re_token_t current_token;
  dfa->syntax = syntax;
  fetch_token (&current_token, regexp, syntax | RE_CARET_ANCHORS_HERE);
  tree = parse_reg_exp (regexp, preg, &current_token, syntax, 0, err);
  if (__glibc_unlikely (*err != REG_NOERROR && tree == NULL))
    return NULL;
  eor = create_tree (dfa, NULL, NULL, END_OF_RE);
  if (tree != NULL)
    root = create_tree (dfa, tree, eor, CONCAT);
  else
    root = eor;
  if (__glibc_unlikely (eor == NULL || root == NULL))
    {
      *err = REG_ESPACE;
      return NULL;
    }
  return root;
}

/* This function build the following tree, from regular expression
   <branch1>|<branch2>:
	   ALT
	   / \
	  /   \
   <branch1> <branch2>

   ALT means alternative, which represents the operator '|'.  */

static bin_tree_t *
parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
	       reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
{
  re_dfa_t *dfa = preg->buffer;
  bin_tree_t *tree, *branch = NULL;
  bitset_word_t initial_bkref_map = dfa->completed_bkref_map;
  tree = parse_branch (regexp, preg, token, syntax, nest, err);
  if (__glibc_unlikely (*err != REG_NOERROR && tree == NULL))
    return NULL;

  while (token->type == OP_ALT)
    {
      fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE);
      if (token->type != OP_ALT && token->type != END_OF_RE
	  && (nest == 0 || token->type != OP_CLOSE_SUBEXP))
	{
	  bitset_word_t accumulated_bkref_map = dfa->completed_bkref_map;
	  dfa->completed_bkref_map = initial_bkref_map;
	  branch = parse_branch (regexp, preg, token, syntax, nest, err);
	  if (__glibc_unlikely (*err != REG_NOERROR && branch == NULL))
	    {
	      if (tree != NULL)
		postorder (tree, free_tree, NULL);
	      return NULL;
	    }
	  dfa->completed_bkref_map |= accumulated_bkref_map;
	}
      else
	branch = NULL;
      tree = create_tree (dfa, tree, branch, OP_ALT);
      if (__glibc_unlikely (tree == NULL))
	{
	  *err = REG_ESPACE;
	  return NULL;
	}
    }
  return tree;
}

/* This function build the following tree, from regular expression
   <exp1><exp2>:
	CAT
	/ \
       /   \
   <exp1> <exp2>

   CAT means concatenation.  */

static bin_tree_t *
parse_branch (re_string_t *regexp, regex_t *preg, re_token_t *token,
	      reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
{
  bin_tree_t *tree, *expr;
  re_dfa_t *dfa = preg->buffer;
  tree = parse_expression (regexp, preg, token, syntax, nest, err);
  if (__glibc_unlikely (*err != REG_NOERROR && tree == NULL))
    return NULL;

  while (token->type != OP_ALT && token->type != END_OF_RE
	 && (nest == 0 || token->type != OP_CLOSE_SUBEXP))
    {
      expr = parse_expression (regexp, preg, token, syntax, nest, err);
      if (__glibc_unlikely (*err != REG_NOERROR && expr == NULL))
	{
	  if (tree != NULL)
	    postorder (tree, free_tree, NULL);
	  return NULL;
	}
      if (tree != NULL && expr != NULL)
	{
	  bin_tree_t *newtree = create_tree (dfa, tree, expr, CONCAT);
	  if (newtree == NULL)
	    {
	      postorder (expr, free_tree, NULL);
	      postorder (tree, free_tree, NULL);
	      *err = REG_ESPACE;
	      return NULL;
	    }
	  tree = newtree;
	}
      else if (tree == NULL)
	tree = expr;
      /* Otherwise expr == NULL, we don't need to create new tree.  */
    }
  return tree;
}

/* This function build the following tree, from regular expression a*:
	 *
	 |
	 a
*/

static bin_tree_t *
parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
		  reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
{
  re_dfa_t *dfa = preg->buffer;
  bin_tree_t *tree;
  switch (token->type)
    {
    case CHARACTER:
      tree = create_token_tree (dfa, NULL, NULL, token);
      if (__glibc_unlikely (tree == NULL))
	{
	  *err = REG_ESPACE;
	  return NULL;
	}
#ifdef RE_ENABLE_I18N
      if (dfa->mb_cur_max > 1)
	{
	  while (!re_string_eoi (regexp)
		 && !re_string_first_byte (regexp, re_string_cur_idx (regexp)))
	    {
	      bin_tree_t *mbc_remain;
	      fetch_token (token, regexp, syntax);
	      mbc_remain = create_token_tree (dfa, NULL, NULL, token);
	      tree = create_tree (dfa, tree, mbc_remain, CONCAT);
	      if (__glibc_unlikely (mbc_remain == NULL || tree == NULL))
		{
		  *err = REG_ESPACE;
		  return NULL;
		}
	    }
	}
#endif
      break;

    case OP_OPEN_SUBEXP:
      tree = parse_sub_exp (regexp, preg, token, syntax, nest + 1, err);
      if (__glibc_unlikely (*err != REG_NOERROR && tree == NULL))
	return NULL;
      break;

    case OP_OPEN_BRACKET:
      tree = parse_bracket_exp (regexp, dfa, token, syntax, err);
      if (__glibc_unlikely (*err != REG_NOERROR && tree == NULL))
	return NULL;
      break;

    case OP_BACK_REF:
      if (!__glibc_likely (dfa->completed_bkref_map & (1 << token->opr.idx)))
	{
	  *err = REG_ESUBREG;
	  return NULL;
	}
      dfa->used_bkref_map |= 1 << token->opr.idx;
      tree = create_token_tree (dfa, NULL, NULL, token);
      if (__glibc_unlikely (tree == NULL))
	{
	  *err = REG_ESPACE;
	  return NULL;
	}
      ++dfa->nbackref;
      dfa->has_mb_node = 1;
      break;

    case OP_OPEN_DUP_NUM:
      if (syntax & RE_CONTEXT_INVALID_DUP)
	{
	  *err = REG_BADRPT;
	  return NULL;
	}
      FALLTHROUGH;
    case OP_DUP_ASTERISK:
    case OP_DUP_PLUS:
    case OP_DUP_QUESTION:
      if (syntax & RE_CONTEXT_INVALID_OPS)
	{
	  *err = REG_BADRPT;
	  return NULL;
	}
      else if (syntax & RE_CONTEXT_INDEP_OPS)
	{
	  fetch_token (token, regexp, syntax);
	  return parse_expression (regexp, preg, token, syntax, nest, err);
	}
      FALLTHROUGH;
    case OP_CLOSE_SUBEXP:
      if ((token->type == OP_CLOSE_SUBEXP)
	  && !(syntax & RE_UNMATCHED_RIGHT_PAREN_ORD))
	{
	  *err = REG_ERPAREN;
	  return NULL;
	}
      FALLTHROUGH;
    case OP_CLOSE_DUP_NUM:
      /* We treat it as a normal character.  */

      /* Then we can these characters as normal characters.  */
      token->type = CHARACTER;
      /* mb_partial and word_char bits should be initialized already
	 by peek_token.  */
      tree = create_token_tree (dfa, NULL, NULL, token);
      if (__glibc_unlikely (tree == NULL))
	{
	  *err = REG_ESPACE;
	  return NULL;
	}
      break;

    case ANCHOR:
      if ((token->opr.ctx_type
	   & (WORD_DELIM | NOT_WORD_DELIM | WORD_FIRST | WORD_LAST))
	  && dfa->word_ops_used == 0)
	init_word_char (dfa);
      if (token->opr.ctx_type == WORD_DELIM
	  || token->opr.ctx_type == NOT_WORD_DELIM)
	{
	  bin_tree_t *tree_first, *tree_last;
	  if (token->opr.ctx_type == WORD_DELIM)
	    {
	      token->opr.ctx_type = WORD_FIRST;
	      tree_first = create_token_tree (dfa, NULL, NULL, token);
	      token->opr.ctx_type = WORD_LAST;
	    }
	  else
	    {
	      token->opr.ctx_type = INSIDE_WORD;
	      tree_first = create_token_tree (dfa, NULL, NULL, token);
	      token->opr.ctx_type = INSIDE_NOTWORD;
	    }
	  tree_last = create_token_tree (dfa, NULL, NULL, token);
	  tree = create_tree (dfa, tree_first, tree_last, OP_ALT);
	  if (__glibc_unlikely (tree_first == NULL || tree_last == NULL
				|| tree == NULL))
	    {
	      *err = REG_ESPACE;
	      return NULL;
	    }
	}
      else
	{
	  tree = create_token_tree (dfa, NULL, NULL, token);
	  if (__glibc_unlikely (tree == NULL))
	    {
	      *err = REG_ESPACE;
	      return NULL;
	    }
	}
      /* We must return here, since ANCHORs can't be followed
	 by repetition operators.
	 eg. RE"^*" is invalid or "<ANCHOR(^)><CHAR(*)>",
	     it must not be "<ANCHOR(^)><REPEAT(*)>".  */
      fetch_token (token, regexp, syntax);
      return tree;

    case OP_PERIOD:
      tree = create_token_tree (dfa, NULL, NULL, token);
      if (__glibc_unlikely (tree == NULL))
	{
	  *err = REG_ESPACE;
	  return NULL;
	}
      if (dfa->mb_cur_max > 1)
	dfa->has_mb_node = 1;
      break;

    case OP_WORD:
    case OP_NOTWORD:
      tree = build_charclass_op (dfa, regexp->trans,
				 "alnum",
				 "_",
				 token->type == OP_NOTWORD, err);
      if (__glibc_unlikely (*err != REG_NOERROR && tree == NULL))
	return NULL;
      break;

    case OP_SPACE:
    case OP_NOTSPACE:
      tree = build_charclass_op (dfa, regexp->trans,
				 "space",
				 "",
				 token->type == OP_NOTSPACE, err);
      if (__glibc_unlikely (*err != REG_NOERROR && tree == NULL))
	return NULL;
      break;

    case OP_ALT:
    case END_OF_RE:
      return NULL;

    case BACK_SLASH:
      *err = REG_EESCAPE;
      return NULL;

    default:
      /* Must not happen?  */
      DEBUG_ASSERT (false);
      return NULL;
    }
  fetch_token (token, regexp, syntax);

  while (token->type == OP_DUP_ASTERISK || token->type == OP_DUP_PLUS
	 || token->type == OP_DUP_QUESTION || token->type == OP_OPEN_DUP_NUM)
    {
      bin_tree_t *dup_tree = parse_dup_op (tree, regexp, dfa, token,
					   syntax, err);
      if (__glibc_unlikely (*err != REG_NOERROR && dup_tree == NULL))
	{
	  if (tree != NULL)
	    postorder (tree, free_tree, NULL);
	  return NULL;
	}
      tree = dup_tree;
      /* In BRE consecutive duplications are not allowed.  */
      if ((syntax & RE_CONTEXT_INVALID_DUP)
	  && (token->type == OP_DUP_ASTERISK
	      || token->type == OP_OPEN_DUP_NUM))
	{
	  if (tree != NULL)
	    postorder (tree, free_tree, NULL);
	  *err = REG_BADRPT;
	  return NULL;
	}
    }

  return tree;
}

/* This function build the following tree, from regular expression
   (<reg_exp>):
	 SUBEXP
	    |
	<reg_exp>
*/

static bin_tree_t *
parse_sub_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
	       reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
{
  re_dfa_t *dfa = preg->buffer;
  bin_tree_t *tree;
  size_t cur_nsub;
  cur_nsub = preg->re_nsub++;

  fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE);

  /* The subexpression may be a null string.  */
  if (token->type == OP_CLOSE_SUBEXP)
    tree = NULL;
  else
    {
      tree = parse_reg_exp (regexp, preg, token, syntax, nest, err);
      if (__glibc_unlikely (*err == REG_NOERROR
			    && token->type != OP_CLOSE_SUBEXP))
	{
	  if (tree != NULL)
	    postorder (tree, free_tree, NULL);
	  *err = REG_EPAREN;
	}
      if (__glibc_unlikely (*err != REG_NOERROR))
	return NULL;
    }

  if (cur_nsub <= '9' - '1')
    dfa->completed_bkref_map |= 1 << cur_nsub;

  tree = create_tree (dfa, tree, NULL, SUBEXP);
  if (__glibc_unlikely (tree == NULL))
    {
      *err = REG_ESPACE;
      return NULL;
    }
  tree->token.opr.idx = cur_nsub;
  return tree;
}

/* This function parse repetition operators like "*", "+", "{1,3}" etc.  */

static bin_tree_t *
parse_dup_op (bin_tree_t *elem, re_string_t *regexp, re_dfa_t *dfa,
	      re_token_t *token, reg_syntax_t syntax, reg_errcode_t *err)
{
  bin_tree_t *tree = NULL, *old_tree = NULL;
  Idx i, start, end, start_idx = re_string_cur_idx (regexp);
  re_token_t start_token = *token;

  if (token->type == OP_OPEN_DUP_NUM)
    {
      end = 0;
      start = fetch_number (regexp, token, syntax);
      if (start == -1)
	{
	  if (token->type == CHARACTER && token->opr.c == ',')
	    start = 0; /* We treat "{,m}" as "{0,m}".  */
	  else
	    {
	      *err = REG_BADBR; /* <re>{} is invalid.  */
	      return NULL;
	    }
	}
      if (__glibc_likely (start != -2))
	{
	  /* We treat "{n}" as "{n,n}".  */
	  end = ((token->type == OP_CLOSE_DUP_NUM) ? start
		 : ((token->type == CHARACTER && token->opr.c == ',')
		    ? fetch_number (regexp, token, syntax) : -2));
	}
      if (__glibc_unlikely (start == -2 || end == -2))
	{
	  /* Invalid sequence.  */
	  if (__glibc_unlikely (!(syntax & RE_INVALID_INTERVAL_ORD)))
	    {
	      if (token->type == END_OF_RE)
		*err = REG_EBRACE;
	      else
		*err = REG_BADBR;

	      return NULL;
	    }

	  /* If the syntax bit is set, rollback.  */
	  re_string_set_index (regexp, start_idx);
	  *token = start_token;
	  token->type = CHARACTER;
	  /* mb_partial and word_char bits should be already initialized by
	     peek_token.  */
	  return elem;
	}

      if (__glibc_unlikely ((end != -1 && start > end)
			    || token->type != OP_CLOSE_DUP_NUM))
	{
	  /* First number greater than second.  */
	  *err = REG_BADBR;
	  return NULL;
	}

      if (__glibc_unlikely (RE_DUP_MAX < (end == -1 ? start : end)))
	{
	  *err = REG_ESIZE;
	  return NULL;
	}
    }
  else
    {
      start = (token->type == OP_DUP_PLUS) ? 1 : 0;
      end = (token->type == OP_DUP_QUESTION) ? 1 : -1;
    }

  fetch_token (token, regexp, syntax);

  if (__glibc_unlikely (elem == NULL))
    return NULL;
  if (__glibc_unlikely (start == 0 && end == 0))
    {
      postorder (elem, free_tree, NULL);
      return NULL;
    }

  /* Extract "<re>{n,m}" to "<re><re>...<re><re>{0,<m-n>}".  */
  if (__glibc_unlikely (start > 0))
    {
      tree = elem;
      for (i = 2; i <= start; ++i)
	{
	  elem = duplicate_tree (elem, dfa);
	  tree = create_tree (dfa, tree, elem, CONCAT);
	  if (__glibc_unlikely (elem == NULL || tree == NULL))
	    goto parse_dup_op_espace;
	}

      if (start == end)
	return tree;

      /* Duplicate ELEM before it is marked optional.  */
      elem = duplicate_tree (elem, dfa);
      if (__glibc_unlikely (elem == NULL))
        goto parse_dup_op_espace;
      old_tree = tree;
    }
  else
    old_tree = NULL;

  if (elem->token.type == SUBEXP)
    {
      uintptr_t subidx = elem->token.opr.idx;
      postorder (elem, mark_opt_subexp, (void *) subidx);
    }

  tree = create_tree (dfa, elem, NULL,
		      (end == -1 ? OP_DUP_ASTERISK : OP_ALT));
  if (__glibc_unlikely (tree == NULL))
    goto parse_dup_op_espace;

  /* This loop is actually executed only when end != -1,
     to rewrite <re>{0,n} as (<re>(<re>...<re>?)?)?...  We have
     already created the start+1-th copy.  */
  if (TYPE_SIGNED (Idx) || end != -1)
    for (i = start + 2; i <= end; ++i)
      {
	elem = duplicate_tree (elem, dfa);
	tree = create_tree (dfa, tree, elem, CONCAT);
	if (__glibc_unlikely (elem == NULL || tree == NULL))
	  goto parse_dup_op_espace;

	tree = create_tree (dfa, tree, NULL, OP_ALT);
	if (__glibc_unlikely (tree == NULL))
	  goto parse_dup_op_espace;
      }

  if (old_tree)
    tree = create_tree (dfa, old_tree, tree, CONCAT);

  return tree;

 parse_dup_op_espace:
  *err = REG_ESPACE;
  return NULL;
}

/* Size of the names for collating symbol/equivalence_class/character_class.
   I'm not sure, but maybe enough.  */
#define BRACKET_NAME_BUF_SIZE 32

#ifndef _LIBC

# ifdef RE_ENABLE_I18N
/* Convert the byte B to the corresponding wide character.  In a
   unibyte locale, treat B as itself.  In a multibyte locale, return
   WEOF if B is an encoding error.  */
static wint_t
parse_byte (unsigned char b, re_charset_t *mbcset)
{
  return mbcset == NULL ? b : __btowc (b);
}
# endif

  /* Local function for parse_bracket_exp only used in case of NOT _LIBC.
     Build the range expression which starts from START_ELEM, and ends
     at END_ELEM.  The result are written to MBCSET and SBCSET.
     RANGE_ALLOC is the allocated size of mbcset->range_starts, and
     mbcset->range_ends, is a pointer argument since we may
     update it.  */

static reg_errcode_t
# ifdef RE_ENABLE_I18N
build_range_exp (const reg_syntax_t syntax,
                 bitset_t sbcset,
                 re_charset_t *mbcset,
                 Idx *range_alloc,
                 const bracket_elem_t *start_elem,
                 const bracket_elem_t *end_elem)
# else /* not RE_ENABLE_I18N */
build_range_exp (const reg_syntax_t syntax,
                 bitset_t sbcset,
                 const bracket_elem_t *start_elem,
                 const bracket_elem_t *end_elem)
# endif /* not RE_ENABLE_I18N */
{
  unsigned int start_ch, end_ch;
  /* Equivalence Classes and Character Classes can't be a range start/end.  */
  if (__glibc_unlikely (start_elem->type == EQUIV_CLASS
			|| start_elem->type == CHAR_CLASS
			|| end_elem->type == EQUIV_CLASS
			|| end_elem->type == CHAR_CLASS))
    return REG_ERANGE;

  /* We can handle no multi character collating elements without libc
     support.  */
  if (__glibc_unlikely ((start_elem->type == COLL_SYM
			 && strlen ((char *) start_elem->opr.name) > 1)
			|| (end_elem->type == COLL_SYM
			    && strlen ((char *) end_elem->opr.name) > 1)))
    return REG_ECOLLATE;

# ifdef RE_ENABLE_I18N
  {
    wchar_t wc;
    wint_t start_wc;
    wint_t end_wc;

    start_ch = ((start_elem->type == SB_CHAR) ? start_elem->opr.ch
		: ((start_elem->type == COLL_SYM) ? start_elem->opr.name[0]
		   : 0));
    end_ch = ((end_elem->type == SB_CHAR) ? end_elem->opr.ch
	      : ((end_elem->type == COLL_SYM) ? end_elem->opr.name[0]
		 : 0));
    start_wc = ((start_elem->type == SB_CHAR || start_elem->type == COLL_SYM)
		? parse_byte (start_ch, mbcset) : start_elem->opr.wch);
    end_wc = ((end_elem->type == SB_CHAR || end_elem->type == COLL_SYM)
	      ? parse_byte (end_ch, mbcset) : end_elem->opr.wch);
    if (start_wc == WEOF || end_wc == WEOF)
      return REG_ECOLLATE;
    else if (__glibc_unlikely ((syntax & RE_NO_EMPTY_RANGES)
			       && start_wc > end_wc))
      return REG_ERANGE;

    /* Got valid collation sequence values, add them as a new entry.
       However, for !_LIBC we have no collation elements: if the
       character set is single byte, the single byte character set
       that we build below suffices.  parse_bracket_exp passes
       no MBCSET if dfa->mb_cur_max == 1.  */
    if (mbcset)
      {
	/* Check the space of the arrays.  */
	if (__glibc_unlikely (*range_alloc == mbcset->nranges))
	  {
	    /* There is not enough space, need realloc.  */
	    wchar_t *new_array_start, *new_array_end;
	    Idx new_nranges;

	    /* +1 in case of mbcset->nranges is 0.  */
	    new_nranges = 2 * mbcset->nranges + 1;
	    /* Use realloc since mbcset->range_starts and mbcset->range_ends
	       are NULL if *range_alloc == 0.  */
	    new_array_start = re_realloc (mbcset->range_starts, wchar_t,
					  new_nranges);
	    new_array_end = re_realloc (mbcset->range_ends, wchar_t,
					new_nranges);

	    if (__glibc_unlikely (new_array_start == NULL
				  || new_array_end == NULL))
	      {
		re_free (new_array_start);
		re_free (new_array_end);
		return REG_ESPACE;
	      }

	    mbcset->range_starts = new_array_start;
	    mbcset->range_ends = new_array_end;
	    *range_alloc = new_nranges;
	  }

	mbcset->range_starts[mbcset->nranges] = start_wc;
	mbcset->range_ends[mbcset->nranges++] = end_wc;
      }

    /* Build the table for single byte characters.  */
    for (wc = 0; wc < SBC_MAX; ++wc)
      {
	if (start_wc <= wc && wc <= end_wc)
	  bitset_set (sbcset, wc);
      }
  }
# else /* not RE_ENABLE_I18N */
  {
    unsigned int ch;
    start_ch = ((start_elem->type == SB_CHAR ) ? start_elem->opr.ch
		: ((start_elem->type == COLL_SYM) ? start_elem->opr.name[0]
		   : 0));
    end_ch = ((end_elem->type == SB_CHAR ) ? end_elem->opr.ch
	      : ((end_elem->type == COLL_SYM) ? end_elem->opr.name[0]
		 : 0));
    if (start_ch > end_ch)
      return REG_ERANGE;
    /* Build the table for single byte characters.  */
    for (ch = 0; ch < SBC_MAX; ++ch)
      if (start_ch <= ch  && ch <= end_ch)
	bitset_set (sbcset, ch);
  }
# endif /* not RE_ENABLE_I18N */
  return REG_NOERROR;
}
#endif /* not _LIBC */

#ifndef _LIBC
/* Helper function for parse_bracket_exp only used in case of NOT _LIBC..
   Build the collating element which is represented by NAME.
   The result are written to MBCSET and SBCSET.
   COLL_SYM_ALLOC is the allocated size of mbcset->coll_sym, is a
   pointer argument since we may update it.  */

static reg_errcode_t
# ifdef RE_ENABLE_I18N
build_collating_symbol (bitset_t sbcset, re_charset_t *mbcset,
			Idx *coll_sym_alloc, const unsigned char *name)
# else /* not RE_ENABLE_I18N */
build_collating_symbol (bitset_t sbcset, const unsigned char *name)
# endif /* not RE_ENABLE_I18N */
{
  size_t name_len = strlen ((const char *) name);
  if (__glibc_unlikely (name_len != 1))
    return REG_ECOLLATE;
  else
    {
      bitset_set (sbcset, name[0]);
      return REG_NOERROR;
    }
}
#endif /* not _LIBC */

/* This function parse bracket expression like "[abc]", "[a-c]",
   "[[.a-a.]]" etc.  */

static bin_tree_t *
parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
		   reg_syntax_t syntax, reg_errcode_t *err)
{
#ifdef _LIBC
  const unsigned char *collseqmb;
  const char *collseqwc;
  uint32_t nrules;
  int32_t table_size;
  const int32_t *symb_table;
  const unsigned char *extra;

  /* Local function for parse_bracket_exp used in _LIBC environment.
     Seek the collating symbol entry corresponding to NAME.
     Return the index of the symbol in the SYMB_TABLE,
     or -1 if not found.  */

  auto inline int32_t
  __attribute__ ((always_inline))
  seek_collating_symbol_entry (const unsigned char *name, size_t name_len)
    {
      int32_t elem;

      for (elem = 0; elem < table_size; elem++)
	if (symb_table[2 * elem] != 0)
	  {
	    int32_t idx = symb_table[2 * elem + 1];
	    /* Skip the name of collating element name.  */
	    idx += 1 + extra[idx];
	    if (/* Compare the length of the name.  */
		name_len == extra[idx]
		/* Compare the name.  */
		&& memcmp (name, &extra[idx + 1], name_len) == 0)
	      /* Yep, this is the entry.  */
	      return elem;
	  }
      return -1;
    }

  /* Local function for parse_bracket_exp used in _LIBC environment.
     Look up the collation sequence value of BR_ELEM.
     Return the value if succeeded, UINT_MAX otherwise.  */

  auto inline unsigned int
  __attribute__ ((always_inline))
  lookup_collation_sequence_value (bracket_elem_t *br_elem)
    {
      if (br_elem->type == SB_CHAR)
	{
	  /*
	  if (MB_CUR_MAX == 1)
	  */
	  if (nrules == 0)
	    return collseqmb[br_elem->opr.ch];
	  else
	    {
	      wint_t wc = __btowc (br_elem->opr.ch);
	      return __collseq_table_lookup (collseqwc, wc);
	    }
	}
      else if (br_elem->type == MB_CHAR)
	{
	  if (nrules != 0)
	    return __collseq_table_lookup (collseqwc, br_elem->opr.wch);
	}
      else if (br_elem->type == COLL_SYM)
	{
	  size_t sym_name_len = strlen ((char *) br_elem->opr.name);
	  if (nrules != 0)
	    {
	      int32_t elem, idx;
	      elem = seek_collating_symbol_entry (br_elem->opr.name,
						  sym_name_len);
	      if (elem != -1)
		{
		  /* We found the entry.  */
		  idx = symb_table[2 * elem + 1];
		  /* Skip the name of collating element name.  */
		  idx += 1 + extra[idx];
		  /* Skip the byte sequence of the collating element.  */
		  idx += 1 + extra[idx];
		  /* Adjust for the alignment.  */
		  idx = (idx + 3) & ~3;
		  /* Skip the multibyte collation sequence value.  */
		  idx += sizeof (unsigned int);
		  /* Skip the wide char sequence of the collating element.  */
		  idx += sizeof (unsigned int) *
		    (1 + *(unsigned int *) (extra + idx));
		  /* Return the collation sequence value.  */
		  return *(unsigned int *) (extra + idx);
		}
	      else if (sym_name_len == 1)
		{
		  /* No valid character.  Match it as a single byte
		     character.  */
		  return collseqmb[br_elem->opr.name[0]];
		}
	    }
	  else if (sym_name_len == 1)
	    return collseqmb[br_elem->opr.name[0]];
	}
      return UINT_MAX;
    }

  /* Local function for parse_bracket_exp used in _LIBC environment.
     Build the range expression which starts from START_ELEM, and ends
     at END_ELEM.  The result are written to MBCSET and SBCSET.
     RANGE_ALLOC is the allocated size of mbcset->range_starts, and
     mbcset->range_ends, is a pointer argument since we may
     update it.  */

  auto inline reg_errcode_t
  __attribute__ ((always_inline))
  build_range_exp (bitset_t sbcset, re_charset_t *mbcset, int *range_alloc,
		   bracket_elem_t *start_elem, bracket_elem_t *end_elem)
    {
      unsigned int ch;
      uint32_t start_collseq;
      uint32_t end_collseq;

      /* Equivalence Classes and Character Classes can't be a range
	 start/end.  */
      if (__glibc_unlikely (start_elem->type == EQUIV_CLASS
			    || start_elem->type == CHAR_CLASS
			    || end_elem->type == EQUIV_CLASS
			    || end_elem->type == CHAR_CLASS))
	return REG_ERANGE;

      /* FIXME: Implement rational ranges here, too.  */
      start_collseq = lookup_collation_sequence_value (start_elem);
      end_collseq = lookup_collation_sequence_value (end_elem);
      /* Check start/end collation sequence values.  */
      if (__glibc_unlikely (start_collseq == UINT_MAX
			    || end_collseq == UINT_MAX))
	return REG_ECOLLATE;
      if (__glibc_unlikely ((syntax & RE_NO_EMPTY_RANGES)
			    && start_collseq > end_collseq))
	return REG_ERANGE;

      /* Got valid collation sequence values, add them as a new entry.
	 However, if we have no collation elements, and the character set
	 is single byte, the single byte character set that we
	 build below suffices. */
      if (nrules > 0 || dfa->mb_cur_max > 1)
	{
	  /* Check the space of the arrays.  */
	  if (__glibc_unlikely (*range_alloc == mbcset->nranges))
	    {
	      /* There is not enough space, need realloc.  */
	      uint32_t *new_array_start;
	      uint32_t *new_array_end;
	      Idx new_nranges;

	      /* +1 in case of mbcset->nranges is 0.  */
	      new_nranges = 2 * mbcset->nranges + 1;
	      new_array_start = re_realloc (mbcset->range_starts, uint32_t,
					    new_nranges);
	      new_array_end = re_realloc (mbcset->range_ends, uint32_t,
					  new_nranges);

	      if (__glibc_unlikely (new_array_start == NULL
				    || new_array_end == NULL))
		return REG_ESPACE;

	      mbcset->range_starts = new_array_start;
	      mbcset->range_ends = new_array_end;
	      *range_alloc = new_nranges;
	    }

	  mbcset->range_starts[mbcset->nranges] = start_collseq;
	  mbcset->range_ends[mbcset->nranges++] = end_collseq;
	}

      /* Build the table for single byte characters.  */
      for (ch = 0; ch < SBC_MAX; ch++)
	{
	  uint32_t ch_collseq;
	  /*
	  if (MB_CUR_MAX == 1)
	  */
	  if (nrules == 0)
	    ch_collseq = collseqmb[ch];
	  else
	    ch_collseq = __collseq_table_lookup (collseqwc, __btowc (ch));
	  if (start_collseq <= ch_collseq && ch_collseq <= end_collseq)
	    bitset_set (sbcset, ch);
	}
      return REG_NOERROR;
    }

  /* Local function for parse_bracket_exp used in _LIBC environment.
     Build the collating element which is represented by NAME.
     The result are written to MBCSET and SBCSET.
     COLL_SYM_ALLOC is the allocated size of mbcset->coll_sym, is a
     pointer argument since we may update it.  */

  auto inline reg_errcode_t
  __attribute__ ((always_inline))
  build_collating_symbol (bitset_t sbcset, re_charset_t *mbcset,
			  Idx *coll_sym_alloc, const unsigned char *name)
    {
      int32_t elem, idx;
      size_t name_len = strlen ((const char *) name);
      if (nrules != 0)
	{
	  elem = seek_collating_symbol_entry (name, name_len);
	  if (elem != -1)
	    {
	      /* We found the entry.  */
	      idx = symb_table[2 * elem + 1];
	      /* Skip the name of collating element name.  */
	      idx += 1 + extra[idx];
	    }
	  else if (name_len == 1)
	    {
	      /* No valid character, treat it as a normal
		 character.  */
	      bitset_set (sbcset, name[0]);
	      return REG_NOERROR;
	    }
	  else
	    return REG_ECOLLATE;

	  /* Got valid collation sequence, add it as a new entry.  */
	  /* Check the space of the arrays.  */
	  if (__glibc_unlikely (*coll_sym_alloc == mbcset->ncoll_syms))
	    {
	      /* Not enough, realloc it.  */
	      /* +1 in case of mbcset->ncoll_syms is 0.  */
	      Idx new_coll_sym_alloc = 2 * mbcset->ncoll_syms + 1;
	      /* Use realloc since mbcset->coll_syms is NULL
		 if *alloc == 0.  */
	      int32_t *new_coll_syms = re_realloc (mbcset->coll_syms, int32_t,
						   new_coll_sym_alloc);
	      if (__glibc_unlikely (new_coll_syms == NULL))
		return REG_ESPACE;
	      mbcset->coll_syms = new_coll_syms;
	      *coll_sym_alloc = new_coll_sym_alloc;
	    }
	  mbcset->coll_syms[mbcset->ncoll_syms++] = idx;
	  return REG_NOERROR;
	}
      else
	{
	  if (__glibc_unlikely (name_len != 1))
	    return REG_ECOLLATE;
	  else
	    {
	      bitset_set (sbcset, name[0]);
	      return REG_NOERROR;
	    }
	}
    }
#endif

  re_token_t br_token;
  re_bitset_ptr_t sbcset;
#ifdef RE_ENABLE_I18N
  re_charset_t *mbcset;
  Idx coll_sym_alloc = 0, range_alloc = 0, mbchar_alloc = 0;
  Idx equiv_class_alloc = 0, char_class_alloc = 0;
#endif /* not RE_ENABLE_I18N */
  bool non_match = false;
  bin_tree_t *work_tree;
  int token_len;
  bool first_round = true;
#ifdef _LIBC
  collseqmb = (const unsigned char *)
    _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQMB);
  nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
  if (nrules)
    {
      /*
      if (MB_CUR_MAX > 1)
      */
      collseqwc = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQWC);
      table_size = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_SYMB_HASH_SIZEMB);
      symb_table = (const int32_t *) _NL_CURRENT (LC_COLLATE,
						  _NL_COLLATE_SYMB_TABLEMB);
      extra = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
						   _NL_COLLATE_SYMB_EXTRAMB);
    }
#endif
  sbcset = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
#ifdef RE_ENABLE_I18N
  mbcset = (re_charset_t *) calloc (sizeof (re_charset_t), 1);
#endif /* RE_ENABLE_I18N */
#ifdef RE_ENABLE_I18N
  if (__glibc_unlikely (sbcset == NULL || mbcset == NULL))
#else
  if (__glibc_unlikely (sbcset == NULL))
#endif /* RE_ENABLE_I18N */
    {
      re_free (sbcset);
#ifdef RE_ENABLE_I18N
      re_free (mbcset);
#endif
      *err = REG_ESPACE;
      return NULL;
    }

  token_len = peek_token_bracket (token, regexp, syntax);
  if (__glibc_unlikely (token->type == END_OF_RE))
    {
      *err = REG_BADPAT;
      goto parse_bracket_exp_free_return;
    }
  if (token->type == OP_NON_MATCH_LIST)
    {
#ifdef RE_ENABLE_I18N
      mbcset->non_match = 1;
#endif /* not RE_ENABLE_I18N */
      non_match = true;
      if (syntax & RE_HAT_LISTS_NOT_NEWLINE)
	bitset_set (sbcset, '\n');
      re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
      token_len = peek_token_bracket (token, regexp, syntax);
      if (__glibc_unlikely (token->type == END_OF_RE))
	{
	  *err = REG_BADPAT;
	  goto parse_bracket_exp_free_return;
	}
    }

  /* We treat the first ']' as a normal character.  */
  if (token->type == OP_CLOSE_BRACKET)
    token->type = CHARACTER;

  while (1)
    {
      bracket_elem_t start_elem, end_elem;
      unsigned char start_name_buf[BRACKET_NAME_BUF_SIZE];
      unsigned char end_name_buf[BRACKET_NAME_BUF_SIZE];
      reg_errcode_t ret;
      int token_len2 = 0;
      bool is_range_exp = false;
      re_token_t token2;

      start_elem.opr.name = start_name_buf;
      start_elem.type = COLL_SYM;
      ret = parse_bracket_element (&start_elem, regexp, token, token_len, dfa,
				   syntax, first_round);
      if (__glibc_unlikely (ret != REG_NOERROR))
	{
	  *err = ret;
	  goto parse_bracket_exp_free_return;
	}
      first_round = false;

      /* Get information about the next token.  We need it in any case.  */
      token_len = peek_token_bracket (token, regexp, syntax);

      /* Do not check for ranges if we know they are not allowed.  */
      if (start_elem.type != CHAR_CLASS && start_elem.type != EQUIV_CLASS)
	{
	  if (__glibc_unlikely (token->type == END_OF_RE))
	    {
	      *err = REG_EBRACK;
	      goto parse_bracket_exp_free_return;
	    }
	  if (token->type == OP_CHARSET_RANGE)
	    {
	      re_string_skip_bytes (regexp, token_len); /* Skip '-'.  */
	      token_len2 = peek_token_bracket (&token2, regexp, syntax);
	      if (__glibc_unlikely (token2.type == END_OF_RE))
		{
		  *err = REG_EBRACK;
		  goto parse_bracket_exp_free_return;
		}
	      if (token2.type == OP_CLOSE_BRACKET)
		{
		  /* We treat the last '-' as a normal character.  */
		  re_string_skip_bytes (regexp, -token_len);
		  token->type = CHARACTER;
		}
	      else
		is_range_exp = true;
	    }
	}

      if (is_range_exp == true)
	{
	  end_elem.opr.name = end_name_buf;
	  end_elem.type = COLL_SYM;
	  ret = parse_bracket_element (&end_elem, regexp, &token2, token_len2,
				       dfa, syntax, true);
	  if (__glibc_unlikely (ret != REG_NOERROR))
	    {
	      *err = ret;
	      goto parse_bracket_exp_free_return;
	    }

	  token_len = peek_token_bracket (token, regexp, syntax);

#ifdef _LIBC
	  *err = build_range_exp (sbcset, mbcset, &range_alloc,
				  &start_elem, &end_elem);
#else
# ifdef RE_ENABLE_I18N
	  *err = build_range_exp (syntax, sbcset,
				  dfa->mb_cur_max > 1 ? mbcset : NULL,
				  &range_alloc, &start_elem, &end_elem);
# else
	  *err = build_range_exp (syntax, sbcset, &start_elem, &end_elem);
# endif
#endif /* RE_ENABLE_I18N */
	  if (__glibc_unlikely (*err != REG_NOERROR))
	    goto parse_bracket_exp_free_return;
	}
      else
	{
	  switch (start_elem.type)
	    {
	    case SB_CHAR:
	      bitset_set (sbcset, start_elem.opr.ch);
	      break;
#ifdef RE_ENABLE_I18N
	    case MB_CHAR:
	      /* Check whether the array has enough space.  */
	      if (__glibc_unlikely (mbchar_alloc == mbcset->nmbchars))
		{
		  wchar_t *new_mbchars;
		  /* Not enough, realloc it.  */
		  /* +1 in case of mbcset->nmbchars is 0.  */
		  mbchar_alloc = 2 * mbcset->nmbchars + 1;
		  /* Use realloc since array is NULL if *alloc == 0.  */
		  new_mbchars = re_realloc (mbcset->mbchars, wchar_t,
					    mbchar_alloc);
		  if (__glibc_unlikely (new_mbchars == NULL))
		    goto parse_bracket_exp_espace;
		  mbcset->mbchars = new_mbchars;
		}
	      mbcset->mbchars[mbcset->nmbchars++] = start_elem.opr.wch;
	      break;
#endif /* RE_ENABLE_I18N */
	    case EQUIV_CLASS:
	      *err = build_equiv_class (sbcset,
#ifdef RE_ENABLE_I18N
					mbcset, &equiv_class_alloc,
#endif /* RE_ENABLE_I18N */
					start_elem.opr.name);
	      if (__glibc_unlikely (*err != REG_NOERROR))
		goto parse_bracket_exp_free_return;
	      break;
	    case COLL_SYM:
	      *err = build_collating_symbol (sbcset,
#ifdef RE_ENABLE_I18N
					     mbcset, &coll_sym_alloc,
#endif /* RE_ENABLE_I18N */
					     start_elem.opr.name);
	      if (__glibc_unlikely (*err != REG_NOERROR))
		goto parse_bracket_exp_free_return;
	      break;
	    case CHAR_CLASS:
	      *err = build_charclass (regexp->trans, sbcset,
#ifdef RE_ENABLE_I18N
				      mbcset, &char_class_alloc,
#endif /* RE_ENABLE_I18N */
				      (const char *) start_elem.opr.name,
				      syntax);
	      if (__glibc_unlikely (*err != REG_NOERROR))
	       goto parse_bracket_exp_free_return;
	      break;
	    default:
	      DEBUG_ASSERT (false);
	      break;
	    }
	}
      if (__glibc_unlikely (token->type == END_OF_RE))
	{
	  *err = REG_EBRACK;
	  goto parse_bracket_exp_free_return;
	}
      if (token->type == OP_CLOSE_BRACKET)
	break;
    }

  re_string_skip_bytes (regexp, token_len); /* Skip a token.  */

  /* If it is non-matching list.  */
  if (non_match)
    bitset_not (sbcset);

#ifdef RE_ENABLE_I18N
  /* Ensure only single byte characters are set.  */
  if (dfa->mb_cur_max > 1)
    bitset_mask (sbcset, dfa->sb_char);

  if (mbcset->nmbchars || mbcset->ncoll_syms || mbcset->nequiv_classes
      || mbcset->nranges || (dfa->mb_cur_max > 1 && (mbcset->nchar_classes
						     || mbcset->non_match)))
    {
      bin_tree_t *mbc_tree;
      int sbc_idx;
      /* Build a tree for complex bracket.  */
      dfa->has_mb_node = 1;
      br_token.type = COMPLEX_BRACKET;
      br_token.opr.mbcset = mbcset;
      mbc_tree = create_token_tree (dfa, NULL, NULL, &br_token);
      if (__glibc_unlikely (mbc_tree == NULL))
	goto parse_bracket_exp_espace;
      for (sbc_idx = 0; sbc_idx < BITSET_WORDS; ++sbc_idx)
	if (sbcset[sbc_idx])
	  break;
      /* If there are no bits set in sbcset, there is no point
	 of having both SIMPLE_BRACKET and COMPLEX_BRACKET.  */
      if (sbc_idx < BITSET_WORDS)
	{
	  /* Build a tree for simple bracket.  */
	  br_token.type = SIMPLE_BRACKET;
	  br_token.opr.sbcset = sbcset;
	  work_tree = create_token_tree (dfa, NULL, NULL, &br_token);
	  if (__glibc_unlikely (work_tree == NULL))
	    goto parse_bracket_exp_espace;

	  /* Then join them by ALT node.  */
	  work_tree = create_tree (dfa, work_tree, mbc_tree, OP_ALT);
	  if (__glibc_unlikely (work_tree == NULL))
	    goto parse_bracket_exp_espace;
	}
      else
	{
	  re_free (sbcset);
	  work_tree = mbc_tree;
	}
    }
  else
#endif /* not RE_ENABLE_I18N */
    {
#ifdef RE_ENABLE_I18N
      free_charset (mbcset);
#endif
      /* Build a tree for simple bracket.  */
      br_token.type = SIMPLE_BRACKET;
      br_token.opr.sbcset = sbcset;
      work_tree = create_token_tree (dfa, NULL, NULL, &br_token);
      if (__glibc_unlikely (work_tree == NULL))
	goto parse_bracket_exp_espace;
    }
  return work_tree;

 parse_bracket_exp_espace:
  *err = REG_ESPACE;
 parse_bracket_exp_free_return:
  re_free (sbcset);
#ifdef RE_ENABLE_I18N
  free_charset (mbcset);
#endif /* RE_ENABLE_I18N */
  return NULL;
}

/* Parse an element in the bracket expression.  */

static reg_errcode_t
parse_bracket_element (bracket_elem_t *elem, re_string_t *regexp,
		       re_token_t *token, int token_len, re_dfa_t *dfa,
		       reg_syntax_t syntax, bool accept_hyphen)
{
#ifdef RE_ENABLE_I18N
  int cur_char_size;
  cur_char_size = re_string_char_size_at (regexp, re_string_cur_idx (regexp));
  if (cur_char_size > 1)
    {
      elem->type = MB_CHAR;
      elem->opr.wch = re_string_wchar_at (regexp, re_string_cur_idx (regexp));
      re_string_skip_bytes (regexp, cur_char_size);
      return REG_NOERROR;
    }
#endif /* RE_ENABLE_I18N */
  re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
  if (token->type == OP_OPEN_COLL_ELEM || token->type == OP_OPEN_CHAR_CLASS
      || token->type == OP_OPEN_EQUIV_CLASS)
    return parse_bracket_symbol (elem, regexp, token);
  if (__glibc_unlikely (token->type == OP_CHARSET_RANGE) && !accept_hyphen)
    {
      /* A '-' must only appear as anything but a range indicator before
	 the closing bracket.  Everything else is an error.  */
      re_token_t token2;
      (void) peek_token_bracket (&token2, regexp, syntax);
      if (token2.type != OP_CLOSE_BRACKET)
	/* The actual error value is not standardized since this whole
	   case is undefined.  But ERANGE makes good sense.  */
	return REG_ERANGE;
    }
  elem->type = SB_CHAR;
  elem->opr.ch = token->opr.c;
  return REG_NOERROR;
}

/* Parse a bracket symbol in the bracket expression.  Bracket symbols are
   such as [:<character_class>:], [.<collating_element>.], and
   [=<equivalent_class>=].  */

static reg_errcode_t
parse_bracket_symbol (bracket_elem_t *elem, re_string_t *regexp,
		      re_token_t *token)
{
  unsigned char ch, delim = token->opr.c;
  int i = 0;
  if (re_string_eoi(regexp))
    return REG_EBRACK;
  for (;; ++i)
    {
      if (i >= BRACKET_NAME_BUF_SIZE)
	return REG_EBRACK;
      if (token->type == OP_OPEN_CHAR_CLASS)
	ch = re_string_fetch_byte_case (regexp);
      else
	ch = re_string_fetch_byte (regexp);
      if (re_string_eoi(regexp))
	return REG_EBRACK;
      if (ch == delim && re_string_peek_byte (regexp, 0) == ']')
	break;
      elem->opr.name[i] = ch;
    }
  re_string_skip_bytes (regexp, 1);
  elem->opr.name[i] = '\0';
  switch (token->type)
    {
    case OP_OPEN_COLL_ELEM:
      elem->type = COLL_SYM;
      break;
    case OP_OPEN_EQUIV_CLASS:
      elem->type = EQUIV_CLASS;
      break;
    case OP_OPEN_CHAR_CLASS:
      elem->type = CHAR_CLASS;
      break;
    default:
      break;
    }
  return REG_NOERROR;
}

  /* Helper function for parse_bracket_exp.
     Build the equivalence class which is represented by NAME.
     The result are written to MBCSET and SBCSET.
     EQUIV_CLASS_ALLOC is the allocated size of mbcset->equiv_classes,
     is a pointer argument since we may update it.  */

static reg_errcode_t
#ifdef RE_ENABLE_I18N
build_equiv_class (bitset_t sbcset, re_charset_t *mbcset,
		   Idx *equiv_class_alloc, const unsigned char *name)
#else /* not RE_ENABLE_I18N */
build_equiv_class (bitset_t sbcset, const unsigned char *name)
#endif /* not RE_ENABLE_I18N */
{
#ifdef _LIBC
  uint32_t nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
  if (nrules != 0)
    {
      const int32_t *table, *indirect;
      const unsigned char *weights, *extra, *cp;
      unsigned char char_buf[2];
      int32_t idx1, idx2;
      unsigned int ch;
      size_t len;
      /* Calculate the index for equivalence class.  */
      cp = name;
      table = (const int32_t *) _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
      weights = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
					       _NL_COLLATE_WEIGHTMB);
      extra = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
						   _NL_COLLATE_EXTRAMB);
      indirect = (const int32_t *) _NL_CURRENT (LC_COLLATE,
						_NL_COLLATE_INDIRECTMB);
      idx1 = findidx (table, indirect, extra, &cp, -1);
      if (__glibc_unlikely (idx1 == 0 || *cp != '\0'))
	/* This isn't a valid character.  */
	return REG_ECOLLATE;

      /* Build single byte matching table for this equivalence class.  */
      len = weights[idx1 & 0xffffff];
      for (ch = 0; ch < SBC_MAX; ++ch)
	{
	  char_buf[0] = ch;
	  cp = char_buf;
	  idx2 = findidx (table, indirect, extra, &cp, 1);
/*
	  idx2 = table[ch];
*/
	  if (idx2 == 0)
	    /* This isn't a valid character.  */
	    continue;
	  /* Compare only if the length matches and the collation rule
	     index is the same.  */
	  if (len == weights[idx2 & 0xffffff] && (idx1 >> 24) == (idx2 >> 24)
	      && memcmp (weights + (idx1 & 0xffffff) + 1,
			 weights + (idx2 & 0xffffff) + 1, len) == 0)
	    bitset_set (sbcset, ch);
	}
      /* Check whether the array has enough space.  */
      if (__glibc_unlikely (*equiv_class_alloc == mbcset->nequiv_classes))
	{
	  /* Not enough, realloc it.  */
	  /* +1 in case of mbcset->nequiv_classes is 0.  */
	  Idx new_equiv_class_alloc = 2 * mbcset->nequiv_classes + 1;
	  /* Use realloc since the array is NULL if *alloc == 0.  */
	  int32_t *new_equiv_classes = re_realloc (mbcset->equiv_classes,
						   int32_t,
						   new_equiv_class_alloc);
	  if (__glibc_unlikely (new_equiv_classes == NULL))
	    return REG_ESPACE;
	  mbcset->equiv_classes = new_equiv_classes;
	  *equiv_class_alloc = new_equiv_class_alloc;
	}
      mbcset->equiv_classes[mbcset->nequiv_classes++] = idx1;
    }
  else
#endif /* _LIBC */
    {
      if (__glibc_unlikely (strlen ((const char *) name) != 1))
	return REG_ECOLLATE;
      bitset_set (sbcset, *name);
    }
  return REG_NOERROR;
}

  /* Helper function for parse_bracket_exp.
     Build the character class which is represented by NAME.
     The result are written to MBCSET and SBCSET.
     CHAR_CLASS_ALLOC is the allocated size of mbcset->char_classes,
     is a pointer argument since we may update it.  */

static reg_errcode_t
#ifdef RE_ENABLE_I18N
build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
		 re_charset_t *mbcset, Idx *char_class_alloc,
		 const char *class_name, reg_syntax_t syntax)
#else /* not RE_ENABLE_I18N */
build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
		 const char *class_name, reg_syntax_t syntax)
#endif /* not RE_ENABLE_I18N */
{
  int i;
  const char *name = class_name;

  /* In case of REG_ICASE "upper" and "lower" match the both of
     upper and lower cases.  */
  if ((syntax & RE_ICASE)
      && (strcmp (name, "upper") == 0 || strcmp (name, "lower") == 0))
    name = "alpha";

#ifdef RE_ENABLE_I18N
  /* Check the space of the arrays.  */
  if (__glibc_unlikely (*char_class_alloc == mbcset->nchar_classes))
    {
      /* Not enough, realloc it.  */
      /* +1 in case of mbcset->nchar_classes is 0.  */
      Idx new_char_class_alloc = 2 * mbcset->nchar_classes + 1;
      /* Use realloc since array is NULL if *alloc == 0.  */
      wctype_t *new_char_classes = re_realloc (mbcset->char_classes, wctype_t,
					       new_char_class_alloc);
      if (__glibc_unlikely (new_char_classes == NULL))
	return REG_ESPACE;
      mbcset->char_classes = new_char_classes;
      *char_class_alloc = new_char_class_alloc;
    }
  mbcset->char_classes[mbcset->nchar_classes++] = __wctype (name);
#endif /* RE_ENABLE_I18N */

#define BUILD_CHARCLASS_LOOP(ctype_func)	\
  do {						\
    if (__glibc_unlikely (trans != NULL))			\
      {						\
	for (i = 0; i < SBC_MAX; ++i)		\
	  if (ctype_func (i))			\
	    bitset_set (sbcset, trans[i]);	\
      }						\
    else					\
      {						\
	for (i = 0; i < SBC_MAX; ++i)		\
	  if (ctype_func (i))			\
	    bitset_set (sbcset, i);		\
      }						\
  } while (0)

  if (strcmp (name, "alnum") == 0)
    BUILD_CHARCLASS_LOOP (isalnum);
  else if (strcmp (name, "cntrl") == 0)
    BUILD_CHARCLASS_LOOP (iscntrl);
  else if (strcmp (name, "lower") == 0)
    BUILD_CHARCLASS_LOOP (islower);
  else if (strcmp (name, "space") == 0)
    BUILD_CHARCLASS_LOOP (isspace);
  else if (strcmp (name, "alpha") == 0)
    BUILD_CHARCLASS_LOOP (isalpha);
  else if (strcmp (name, "digit") == 0)
    BUILD_CHARCLASS_LOOP (isdigit);
  else if (strcmp (name, "print") == 0)
    BUILD_CHARCLASS_LOOP (isprint);
  else if (strcmp (name, "upper") == 0)
    BUILD_CHARCLASS_LOOP (isupper);
  else if (strcmp (name, "blank") == 0)
    BUILD_CHARCLASS_LOOP (isblank);
  else if (strcmp (name, "graph") == 0)
    BUILD_CHARCLASS_LOOP (isgraph);
  else if (strcmp (name, "punct") == 0)
    BUILD_CHARCLASS_LOOP (ispunct);
  else if (strcmp (name, "xdigit") == 0)
    BUILD_CHARCLASS_LOOP (isxdigit);
  else
    return REG_ECTYPE;

  return REG_NOERROR;
}

static bin_tree_t *
build_charclass_op (re_dfa_t *dfa, RE_TRANSLATE_TYPE trans,
		    const char *class_name,
		    const char *extra, bool non_match,
		    reg_errcode_t *err)
{
  re_bitset_ptr_t sbcset;
#ifdef RE_ENABLE_I18N
  re_charset_t *mbcset;
  Idx alloc = 0;
#endif /* not RE_ENABLE_I18N */
  reg_errcode_t ret;
  bin_tree_t *tree;

  sbcset = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
  if (__glibc_unlikely (sbcset == NULL))
    {
      *err = REG_ESPACE;
      return NULL;
    }
#ifdef RE_ENABLE_I18N
  mbcset = (re_charset_t *) calloc (sizeof (re_charset_t), 1);
  if (__glibc_unlikely (mbcset == NULL))
    {
      re_free (sbcset);
      *err = REG_ESPACE;
      return NULL;
    }
  mbcset->non_match = non_match;
#endif /* RE_ENABLE_I18N */

  /* We don't care the syntax in this case.  */
  ret = build_charclass (trans, sbcset,
#ifdef RE_ENABLE_I18N
			 mbcset, &alloc,
#endif /* RE_ENABLE_I18N */
			 class_name, 0);

  if (__glibc_unlikely (ret != REG_NOERROR))
    {
      re_free (sbcset);
#ifdef RE_ENABLE_I18N
      free_charset (mbcset);
#endif /* RE_ENABLE_I18N */
      *err = ret;
      return NULL;
    }
  /* \w match '_' also.  */
  for (; *extra; extra++)
    bitset_set (sbcset, *extra);

  /* If it is non-matching list.  */
  if (non_match)
    bitset_not (sbcset);

#ifdef RE_ENABLE_I18N
  /* Ensure only single byte characters are set.  */
  if (dfa->mb_cur_max > 1)
    bitset_mask (sbcset, dfa->sb_char);
#endif

  /* Build a tree for simple bracket.  */
  re_token_t br_token = { .type = SIMPLE_BRACKET, .opr.sbcset = sbcset };
  tree = create_token_tree (dfa, NULL, NULL, &br_token);
  if (__glibc_unlikely (tree == NULL))
    goto build_word_op_espace;

#ifdef RE_ENABLE_I18N
  if (dfa->mb_cur_max > 1)
    {
      bin_tree_t *mbc_tree;
      /* Build a tree for complex bracket.  */
      br_token.type = COMPLEX_BRACKET;
      br_token.opr.mbcset = mbcset;
      dfa->has_mb_node = 1;
      mbc_tree = create_token_tree (dfa, NULL, NULL, &br_token);
      if (__glibc_unlikely (mbc_tree == NULL))
	goto build_word_op_espace;
      /* Then join them by ALT node.  */
      tree = create_tree (dfa, tree, mbc_tree, OP_ALT);
      if (__glibc_likely (mbc_tree != NULL))
	return tree;
    }
  else
    {
      free_charset (mbcset);
      return tree;
    }
#else /* not RE_ENABLE_I18N */
  return tree;
#endif /* not RE_ENABLE_I18N */

 build_word_op_espace:
  re_free (sbcset);
#ifdef RE_ENABLE_I18N
  free_charset (mbcset);
#endif /* RE_ENABLE_I18N */
  *err = REG_ESPACE;
  return NULL;
}

/* This is intended for the expressions like "a{1,3}".
   Fetch a number from 'input', and return the number.
   Return -1 if the number field is empty like "{,1}".
   Return RE_DUP_MAX + 1 if the number field is too large.
   Return -2 if an error occurred.  */

static Idx
fetch_number (re_string_t *input, re_token_t *token, reg_syntax_t syntax)
{
  Idx num = -1;
  unsigned char c;
  while (1)
    {
      fetch_token (token, input, syntax);
      c = token->opr.c;
      if (__glibc_unlikely (token->type == END_OF_RE))
	return -2;
      if (token->type == OP_CLOSE_DUP_NUM || c == ',')
	break;
      num = ((token->type != CHARACTER || c < '0' || '9' < c || num == -2)
	     ? -2
	     : num == -1
	     ? c - '0'
	     : MIN (RE_DUP_MAX + 1, num * 10 + c - '0'));
    }
  return num;
}

#ifdef RE_ENABLE_I18N
static void
free_charset (re_charset_t *cset)
{
  re_free (cset->mbchars);
# ifdef _LIBC
  re_free (cset->coll_syms);
  re_free (cset->equiv_classes);
# endif
  re_free (cset->range_starts);
  re_free (cset->range_ends);
  re_free (cset->char_classes);
  re_free (cset);
}
#endif /* RE_ENABLE_I18N */

/* Functions for binary tree operation.  */

/* Create a tree node.  */

static bin_tree_t *
create_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
	     re_token_type_t type)
{
  re_token_t t = { .type = type };
  return create_token_tree (dfa, left, right, &t);
}

static bin_tree_t *
create_token_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
		   const re_token_t *token)
{
  bin_tree_t *tree;
  if (__glibc_unlikely (dfa->str_tree_storage_idx == BIN_TREE_STORAGE_SIZE))
    {
      bin_tree_storage_t *storage = re_malloc (bin_tree_storage_t, 1);

      if (storage == NULL)
	return NULL;
      storage->next = dfa->str_tree_storage;
      dfa->str_tree_storage = storage;
      dfa->str_tree_storage_idx = 0;
    }
  tree = &dfa->str_tree_storage->data[dfa->str_tree_storage_idx++];

  tree->parent = NULL;
  tree->left = left;
  tree->right = right;
  tree->token = *token;
  tree->token.duplicated = 0;
  tree->token.opt_subexp = 0;
  tree->first = NULL;
  tree->next = NULL;
  tree->node_idx = -1;

  if (left != NULL)
    left->parent = tree;
  if (right != NULL)
    right->parent = tree;
  return tree;
}

/* Mark the tree SRC as an optional subexpression.
   To be called from preorder or postorder.  */

static reg_errcode_t
mark_opt_subexp (void *extra, bin_tree_t *node)
{
  Idx idx = (uintptr_t) extra;
  if (node->token.type == SUBEXP && node->token.opr.idx == idx)
    node->token.opt_subexp = 1;

  return REG_NOERROR;
}

/* Free the allocated memory inside NODE. */

static void
free_token (re_token_t *node)
{
#ifdef RE_ENABLE_I18N
  if (node->type == COMPLEX_BRACKET && node->duplicated == 0)
    free_charset (node->opr.mbcset);
  else
#endif /* RE_ENABLE_I18N */
    if (node->type == SIMPLE_BRACKET && node->duplicated == 0)
      re_free (node->opr.sbcset);
}

/* Worker function for tree walking.  Free the allocated memory inside NODE
   and its children. */

static reg_errcode_t
free_tree (void *extra, bin_tree_t *node)
{
  free_token (&node->token);
  return REG_NOERROR;
}


/* Duplicate the node SRC, and return new node.  This is a preorder
   visit similar to the one implemented by the generic visitor, but
   we need more infrastructure to maintain two parallel trees --- so,
   it's easier to duplicate.  */

static bin_tree_t *
duplicate_tree (const bin_tree_t *root, re_dfa_t *dfa)
{
  const bin_tree_t *node;
  bin_tree_t *dup_root;
  bin_tree_t **p_new = &dup_root, *dup_node = root->parent;

  for (node = root; ; )
    {
      /* Create a new tree and link it back to the current parent.  */
      *p_new = create_token_tree (dfa, NULL, NULL, &node->token);
      if (*p_new == NULL)
	return NULL;
      (*p_new)->parent = dup_node;
      (*p_new)->token.duplicated = 1;
      dup_node = *p_new;

      /* Go to the left node, or up and to the right.  */
      if (node->left)
	{
	  node = node->left;
	  p_new = &dup_node->left;
	}
      else
	{
	  const bin_tree_t *prev = NULL;
	  while (node->right == prev || node->right == NULL)
	    {
	      prev = node;
	      node = node->parent;
	      dup_node = dup_node->parent;
	      if (!node)
		return dup_root;
	    }
	  node = node->right;
	  p_new = &dup_node->right;
	}
    }
}