File: pcre_study.c

package info (click to toggle)
pcre3 2:8.39-3
  • links: PTS
  • area: main
  • in suites: stretch
  • size: 11,688 kB
  • ctags: 10,424
  • sloc: ansic: 70,010; sh: 5,747; cpp: 4,224; makefile: 797; pascal: 617; perl: 516
file content (1686 lines) | stat: -rw-r--r-- 48,586 bytes parent folder | download | duplicates (22)
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
/*************************************************
*      Perl-Compatible Regular Expressions       *
*************************************************/

/* PCRE is a library of functions to support regular expressions whose syntax
and semantics are as close as possible to those of the Perl 5 language.

                       Written by Philip Hazel
           Copyright (c) 1997-2012 University of Cambridge

-----------------------------------------------------------------------------
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.

    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.

    * Neither the name of the University of Cambridge nor the names of its
      contributors may be used to endorse or promote products derived from
      this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
-----------------------------------------------------------------------------
*/


/* This module contains the external function pcre_study(), along with local
supporting functions. */


#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "pcre_internal.h"

#define SET_BIT(c) start_bits[c/8] |= (1 << (c&7))

/* Returns from set_start_bits() */

enum { SSB_FAIL, SSB_DONE, SSB_CONTINUE, SSB_UNKNOWN };



/*************************************************
*   Find the minimum subject length for a group  *
*************************************************/

/* Scan a parenthesized group and compute the minimum length of subject that
is needed to match it. This is a lower bound; it does not mean there is a
string of that length that matches. In UTF8 mode, the result is in characters
rather than bytes.

Arguments:
  re              compiled pattern block
  code            pointer to start of group (the bracket)
  startcode       pointer to start of the whole pattern's code
  options         the compiling options
  recurses        chain of recurse_check to catch mutual recursion
  countptr        pointer to call count (to catch over complexity)

Returns:   the minimum length
           -1 if \C in UTF-8 mode or (*ACCEPT) was encountered
           -2 internal error (missing capturing bracket)
           -3 internal error (opcode not listed)
*/

static int
find_minlength(const REAL_PCRE *re, const pcre_uchar *code,
  const pcre_uchar *startcode, int options, recurse_check *recurses,
  int *countptr)
{
int length = -1;
/* PCRE_UTF16 has the same value as PCRE_UTF8. */
BOOL utf = (options & PCRE_UTF8) != 0;
BOOL had_recurse = FALSE;
recurse_check this_recurse;
register int branchlength = 0;
register pcre_uchar *cc = (pcre_uchar *)code + 1 + LINK_SIZE;

if ((*countptr)++ > 1000) return -1;   /* too complex */

if (*code == OP_CBRA || *code == OP_SCBRA ||
    *code == OP_CBRAPOS || *code == OP_SCBRAPOS) cc += IMM2_SIZE;

/* Scan along the opcodes for this branch. If we get to the end of the
branch, check the length against that of the other branches. */

for (;;)
  {
  int d, min;
  pcre_uchar *cs, *ce;
  register pcre_uchar op = *cc;

  switch (op)
    {
    case OP_COND:
    case OP_SCOND:

    /* If there is only one branch in a condition, the implied branch has zero
    length, so we don't add anything. This covers the DEFINE "condition"
    automatically. */

    cs = cc + GET(cc, 1);
    if (*cs != OP_ALT)
      {
      cc = cs + 1 + LINK_SIZE;
      break;
      }

    /* Otherwise we can fall through and treat it the same as any other
    subpattern. */

    case OP_CBRA:
    case OP_SCBRA:
    case OP_BRA:
    case OP_SBRA:
    case OP_CBRAPOS:
    case OP_SCBRAPOS:
    case OP_BRAPOS:
    case OP_SBRAPOS:
    case OP_ONCE:
    case OP_ONCE_NC:
    d = find_minlength(re, cc, startcode, options, recurses, countptr);
    if (d < 0) return d;
    branchlength += d;
    do cc += GET(cc, 1); while (*cc == OP_ALT);
    cc += 1 + LINK_SIZE;
    break;

    /* ACCEPT makes things far too complicated; we have to give up. */

    case OP_ACCEPT:
    case OP_ASSERT_ACCEPT:
    return -1;

    /* Reached end of a branch; if it's a ket it is the end of a nested
    call. If it's ALT it is an alternation in a nested call. If it is END it's
    the end of the outer call. All can be handled by the same code. If an
    ACCEPT was previously encountered, use the length that was in force at that
    time, and pass back the shortest ACCEPT length. */

    case OP_ALT:
    case OP_KET:
    case OP_KETRMAX:
    case OP_KETRMIN:
    case OP_KETRPOS:
    case OP_END:
    if (length < 0 || (!had_recurse && branchlength < length))
      length = branchlength;
    if (op != OP_ALT) return length;
    cc += 1 + LINK_SIZE;
    branchlength = 0;
    had_recurse = FALSE;
    break;

    /* Skip over assertive subpatterns */

    case OP_ASSERT:
    case OP_ASSERT_NOT:
    case OP_ASSERTBACK:
    case OP_ASSERTBACK_NOT:
    do cc += GET(cc, 1); while (*cc == OP_ALT);
    /* Fall through */

    /* Skip over things that don't match chars */

    case OP_REVERSE:
    case OP_CREF:
    case OP_DNCREF:
    case OP_RREF:
    case OP_DNRREF:
    case OP_DEF:
    case OP_CALLOUT:
    case OP_SOD:
    case OP_SOM:
    case OP_EOD:
    case OP_EODN:
    case OP_CIRC:
    case OP_CIRCM:
    case OP_DOLL:
    case OP_DOLLM:
    case OP_NOT_WORD_BOUNDARY:
    case OP_WORD_BOUNDARY:
    cc += PRIV(OP_lengths)[*cc];
    break;

    /* Skip over a subpattern that has a {0} or {0,x} quantifier */

    case OP_BRAZERO:
    case OP_BRAMINZERO:
    case OP_BRAPOSZERO:
    case OP_SKIPZERO:
    cc += PRIV(OP_lengths)[*cc];
    do cc += GET(cc, 1); while (*cc == OP_ALT);
    cc += 1 + LINK_SIZE;
    break;

    /* Handle literal characters and + repetitions */

    case OP_CHAR:
    case OP_CHARI:
    case OP_NOT:
    case OP_NOTI:
    case OP_PLUS:
    case OP_PLUSI:
    case OP_MINPLUS:
    case OP_MINPLUSI:
    case OP_POSPLUS:
    case OP_POSPLUSI:
    case OP_NOTPLUS:
    case OP_NOTPLUSI:
    case OP_NOTMINPLUS:
    case OP_NOTMINPLUSI:
    case OP_NOTPOSPLUS:
    case OP_NOTPOSPLUSI:
    branchlength++;
    cc += 2;
#ifdef SUPPORT_UTF
    if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
#endif
    break;

    case OP_TYPEPLUS:
    case OP_TYPEMINPLUS:
    case OP_TYPEPOSPLUS:
    branchlength++;
    cc += (cc[1] == OP_PROP || cc[1] == OP_NOTPROP)? 4 : 2;
    break;

    /* Handle exact repetitions. The count is already in characters, but we
    need to skip over a multibyte character in UTF8 mode.  */

    case OP_EXACT:
    case OP_EXACTI:
    case OP_NOTEXACT:
    case OP_NOTEXACTI:
    branchlength += GET2(cc,1);
    cc += 2 + IMM2_SIZE;
#ifdef SUPPORT_UTF
    if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
#endif
    break;

    case OP_TYPEEXACT:
    branchlength += GET2(cc,1);
    cc += 2 + IMM2_SIZE + ((cc[1 + IMM2_SIZE] == OP_PROP
      || cc[1 + IMM2_SIZE] == OP_NOTPROP)? 2 : 0);
    break;

    /* Handle single-char non-literal matchers */

    case OP_PROP:
    case OP_NOTPROP:
    cc += 2;
    /* Fall through */

    case OP_NOT_DIGIT:
    case OP_DIGIT:
    case OP_NOT_WHITESPACE:
    case OP_WHITESPACE:
    case OP_NOT_WORDCHAR:
    case OP_WORDCHAR:
    case OP_ANY:
    case OP_ALLANY:
    case OP_EXTUNI:
    case OP_HSPACE:
    case OP_NOT_HSPACE:
    case OP_VSPACE:
    case OP_NOT_VSPACE:
    branchlength++;
    cc++;
    break;

    /* "Any newline" might match two characters, but it also might match just
    one. */

    case OP_ANYNL:
    branchlength += 1;
    cc++;
    break;

    /* The single-byte matcher means we can't proceed in UTF-8 mode. (In
    non-UTF-8 mode \C will actually be turned into OP_ALLANY, so won't ever
    appear, but leave the code, just in case.) */

    case OP_ANYBYTE:
#ifdef SUPPORT_UTF
    if (utf) return -1;
#endif
    branchlength++;
    cc++;
    break;

    /* For repeated character types, we have to test for \p and \P, which have
    an extra two bytes of parameters. */

    case OP_TYPESTAR:
    case OP_TYPEMINSTAR:
    case OP_TYPEQUERY:
    case OP_TYPEMINQUERY:
    case OP_TYPEPOSSTAR:
    case OP_TYPEPOSQUERY:
    if (cc[1] == OP_PROP || cc[1] == OP_NOTPROP) cc += 2;
    cc += PRIV(OP_lengths)[op];
    break;

    case OP_TYPEUPTO:
    case OP_TYPEMINUPTO:
    case OP_TYPEPOSUPTO:
    if (cc[1 + IMM2_SIZE] == OP_PROP
      || cc[1 + IMM2_SIZE] == OP_NOTPROP) cc += 2;
    cc += PRIV(OP_lengths)[op];
    break;

    /* Check a class for variable quantification */

    case OP_CLASS:
    case OP_NCLASS:
#if defined SUPPORT_UTF || defined COMPILE_PCRE16 || defined COMPILE_PCRE32
    case OP_XCLASS:
    /* The original code caused an unsigned overflow in 64 bit systems,
    so now we use a conditional statement. */
    if (op == OP_XCLASS)
      cc += GET(cc, 1);
    else
      cc += PRIV(OP_lengths)[OP_CLASS];
#else
    cc += PRIV(OP_lengths)[OP_CLASS];
#endif

    switch (*cc)
      {
      case OP_CRPLUS:
      case OP_CRMINPLUS:
      case OP_CRPOSPLUS:
      branchlength++;
      /* Fall through */

      case OP_CRSTAR:
      case OP_CRMINSTAR:
      case OP_CRQUERY:
      case OP_CRMINQUERY:
      case OP_CRPOSSTAR:
      case OP_CRPOSQUERY:
      cc++;
      break;

      case OP_CRRANGE:
      case OP_CRMINRANGE:
      case OP_CRPOSRANGE:
      branchlength += GET2(cc,1);
      cc += 1 + 2 * IMM2_SIZE;
      break;

      default:
      branchlength++;
      break;
      }
    break;

    /* Backreferences and subroutine calls are treated in the same way: we find
    the minimum length for the subpattern. A recursion, however, causes an
    a flag to be set that causes the length of this branch to be ignored. The
    logic is that a recursion can only make sense if there is another
    alternation that stops the recursing. That will provide the minimum length
    (when no recursion happens). A backreference within the group that it is
    referencing behaves in the same way.

    If PCRE_JAVASCRIPT_COMPAT is set, a backreference to an unset bracket
    matches an empty string (by default it causes a matching failure), so in
    that case we must set the minimum length to zero. */

    case OP_DNREF:     /* Duplicate named pattern back reference */
    case OP_DNREFI:
    if ((options & PCRE_JAVASCRIPT_COMPAT) == 0)
      {
      int count = GET2(cc, 1+IMM2_SIZE);
      pcre_uchar *slot = (pcre_uchar *)re +
        re->name_table_offset + GET2(cc, 1) * re->name_entry_size;
      d = INT_MAX;
      while (count-- > 0)
        {
        ce = cs = (pcre_uchar *)PRIV(find_bracket)(startcode, utf, GET2(slot, 0));
        if (cs == NULL) return -2;
        do ce += GET(ce, 1); while (*ce == OP_ALT);
        if (cc > cs && cc < ce)     /* Simple recursion */
          {
          d = 0;
          had_recurse = TRUE;
          break;
          }
        else
          {
          recurse_check *r = recurses;
          for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break;
          if (r != NULL)           /* Mutual recursion */
            {
            d = 0;
            had_recurse = TRUE;
            break;
            }
          else
            {
            int dd;
            this_recurse.prev = recurses;
            this_recurse.group = cs;
            dd = find_minlength(re, cs, startcode, options, &this_recurse,
              countptr);
            if (dd < d) d = dd;
            }
          }
        slot += re->name_entry_size;
        }
      }
    else d = 0;
    cc += 1 + 2*IMM2_SIZE;
    goto REPEAT_BACK_REFERENCE;

    case OP_REF:      /* Single back reference */
    case OP_REFI:
    if ((options & PCRE_JAVASCRIPT_COMPAT) == 0)
      {
      ce = cs = (pcre_uchar *)PRIV(find_bracket)(startcode, utf, GET2(cc, 1));
      if (cs == NULL) return -2;
      do ce += GET(ce, 1); while (*ce == OP_ALT);
      if (cc > cs && cc < ce)    /* Simple recursion */
        {
        d = 0;
        had_recurse = TRUE;
        }
      else
        {
        recurse_check *r = recurses;
        for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break;
        if (r != NULL)           /* Mutual recursion */
          {
          d = 0;
          had_recurse = TRUE;
          }
        else
          {
          this_recurse.prev = recurses;
          this_recurse.group = cs;
          d = find_minlength(re, cs, startcode, options, &this_recurse,
            countptr);
          }
        }
      }
    else d = 0;
    cc += 1 + IMM2_SIZE;

    /* Handle repeated back references */

    REPEAT_BACK_REFERENCE:
    switch (*cc)
      {
      case OP_CRSTAR:
      case OP_CRMINSTAR:
      case OP_CRQUERY:
      case OP_CRMINQUERY:
      case OP_CRPOSSTAR:
      case OP_CRPOSQUERY:
      min = 0;
      cc++;
      break;

      case OP_CRPLUS:
      case OP_CRMINPLUS:
      case OP_CRPOSPLUS:
      min = 1;
      cc++;
      break;

      case OP_CRRANGE:
      case OP_CRMINRANGE:
      case OP_CRPOSRANGE:
      min = GET2(cc, 1);
      cc += 1 + 2 * IMM2_SIZE;
      break;

      default:
      min = 1;
      break;
      }

    branchlength += min * d;
    break;

    /* We can easily detect direct recursion, but not mutual recursion. This is
    caught by a recursion depth count. */

    case OP_RECURSE:
    cs = ce = (pcre_uchar *)startcode + GET(cc, 1);
    do ce += GET(ce, 1); while (*ce == OP_ALT);
    if (cc > cs && cc < ce)    /* Simple recursion */
      had_recurse = TRUE;
    else
      {
      recurse_check *r = recurses;
      for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break;
      if (r != NULL)           /* Mutual recursion */
        had_recurse = TRUE;
      else
        {
        this_recurse.prev = recurses;
        this_recurse.group = cs;
        branchlength += find_minlength(re, cs, startcode, options,
          &this_recurse, countptr);
        }
      }
    cc += 1 + LINK_SIZE;
    break;

    /* Anything else does not or need not match a character. We can get the
    item's length from the table, but for those that can match zero occurrences
    of a character, we must take special action for UTF-8 characters. As it
    happens, the "NOT" versions of these opcodes are used at present only for
    ASCII characters, so they could be omitted from this list. However, in
    future that may change, so we include them here so as not to leave a
    gotcha for a future maintainer. */

    case OP_UPTO:
    case OP_UPTOI:
    case OP_NOTUPTO:
    case OP_NOTUPTOI:
    case OP_MINUPTO:
    case OP_MINUPTOI:
    case OP_NOTMINUPTO:
    case OP_NOTMINUPTOI:
    case OP_POSUPTO:
    case OP_POSUPTOI:
    case OP_NOTPOSUPTO:
    case OP_NOTPOSUPTOI:

    case OP_STAR:
    case OP_STARI:
    case OP_NOTSTAR:
    case OP_NOTSTARI:
    case OP_MINSTAR:
    case OP_MINSTARI:
    case OP_NOTMINSTAR:
    case OP_NOTMINSTARI:
    case OP_POSSTAR:
    case OP_POSSTARI:
    case OP_NOTPOSSTAR:
    case OP_NOTPOSSTARI:

    case OP_QUERY:
    case OP_QUERYI:
    case OP_NOTQUERY:
    case OP_NOTQUERYI:
    case OP_MINQUERY:
    case OP_MINQUERYI:
    case OP_NOTMINQUERY:
    case OP_NOTMINQUERYI:
    case OP_POSQUERY:
    case OP_POSQUERYI:
    case OP_NOTPOSQUERY:
    case OP_NOTPOSQUERYI:

    cc += PRIV(OP_lengths)[op];
#ifdef SUPPORT_UTF
    if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
#endif
    break;

    /* Skip these, but we need to add in the name length. */

    case OP_MARK:
    case OP_PRUNE_ARG:
    case OP_SKIP_ARG:
    case OP_THEN_ARG:
    cc += PRIV(OP_lengths)[op] + cc[1];
    break;

    /* The remaining opcodes are just skipped over. */

    case OP_CLOSE:
    case OP_COMMIT:
    case OP_FAIL:
    case OP_PRUNE:
    case OP_SET_SOM:
    case OP_SKIP:
    case OP_THEN:
    cc += PRIV(OP_lengths)[op];
    break;

    /* This should not occur: we list all opcodes explicitly so that when
    new ones get added they are properly considered. */

    default:
    return -3;
    }
  }
/* Control never gets here */
}



/*************************************************
*      Set a bit and maybe its alternate case    *
*************************************************/

/* Given a character, set its first byte's bit in the table, and also the
corresponding bit for the other version of a letter if we are caseless. In
UTF-8 mode, for characters greater than 127, we can only do the caseless thing
when Unicode property support is available.

Arguments:
  start_bits    points to the bit map
  p             points to the character
  caseless      the caseless flag
  cd            the block with char table pointers
  utf           TRUE for UTF-8 / UTF-16 / UTF-32 mode

Returns:        pointer after the character
*/

static const pcre_uchar *
set_table_bit(pcre_uint8 *start_bits, const pcre_uchar *p, BOOL caseless,
  compile_data *cd, BOOL utf)
{
pcre_uint32 c = *p;

#ifdef COMPILE_PCRE8
SET_BIT(c);

#ifdef SUPPORT_UTF
if (utf && c > 127)
  {
  GETCHARINC(c, p);
#ifdef SUPPORT_UCP
  if (caseless)
    {
    pcre_uchar buff[6];
    c = UCD_OTHERCASE(c);
    (void)PRIV(ord2utf)(c, buff);
    SET_BIT(buff[0]);
    }
#endif  /* Not SUPPORT_UCP */
  return p;
  }
#else   /* Not SUPPORT_UTF */
(void)(utf);   /* Stops warning for unused parameter */
#endif  /* SUPPORT_UTF */

/* Not UTF-8 mode, or character is less than 127. */

if (caseless && (cd->ctypes[c] & ctype_letter) != 0) SET_BIT(cd->fcc[c]);
return p + 1;
#endif  /* COMPILE_PCRE8 */

#if defined COMPILE_PCRE16 || defined COMPILE_PCRE32
if (c > 0xff)
  {
  c = 0xff;
  caseless = FALSE;
  }
SET_BIT(c);

#ifdef SUPPORT_UTF
if (utf && c > 127)
  {
  GETCHARINC(c, p);
#ifdef SUPPORT_UCP
  if (caseless)
    {
    c = UCD_OTHERCASE(c);
    if (c > 0xff)
      c = 0xff;
    SET_BIT(c);
    }
#endif  /* SUPPORT_UCP */
  return p;
  }
#else   /* Not SUPPORT_UTF */
(void)(utf);   /* Stops warning for unused parameter */
#endif  /* SUPPORT_UTF */

if (caseless && (cd->ctypes[c] & ctype_letter) != 0) SET_BIT(cd->fcc[c]);
return p + 1;
#endif
}



/*************************************************
*     Set bits for a positive character type     *
*************************************************/

/* This function sets starting bits for a character type. In UTF-8 mode, we can
only do a direct setting for bytes less than 128, as otherwise there can be
confusion with bytes in the middle of UTF-8 characters. In a "traditional"
environment, the tables will only recognize ASCII characters anyway, but in at
least one Windows environment, some higher bytes bits were set in the tables.
So we deal with that case by considering the UTF-8 encoding.

Arguments:
  start_bits     the starting bitmap
  cbit type      the type of character wanted
  table_limit    32 for non-UTF-8; 16 for UTF-8
  cd             the block with char table pointers

Returns:         nothing
*/

static void
set_type_bits(pcre_uint8 *start_bits, int cbit_type, unsigned int table_limit,
  compile_data *cd)
{
register pcre_uint32 c;
for (c = 0; c < table_limit; c++) start_bits[c] |= cd->cbits[c+cbit_type];
#if defined SUPPORT_UTF && defined COMPILE_PCRE8
if (table_limit == 32) return;
for (c = 128; c < 256; c++)
  {
  if ((cd->cbits[c/8] & (1 << (c&7))) != 0)
    {
    pcre_uchar buff[6];
    (void)PRIV(ord2utf)(c, buff);
    SET_BIT(buff[0]);
    }
  }
#endif
}


/*************************************************
*     Set bits for a negative character type     *
*************************************************/

/* This function sets starting bits for a negative character type such as \D.
In UTF-8 mode, we can only do a direct setting for bytes less than 128, as
otherwise there can be confusion with bytes in the middle of UTF-8 characters.
Unlike in the positive case, where we can set appropriate starting bits for
specific high-valued UTF-8 characters, in this case we have to set the bits for
all high-valued characters. The lowest is 0xc2, but we overkill by starting at
0xc0 (192) for simplicity.

Arguments:
  start_bits     the starting bitmap
  cbit type      the type of character wanted
  table_limit    32 for non-UTF-8; 16 for UTF-8
  cd             the block with char table pointers

Returns:         nothing
*/

static void
set_nottype_bits(pcre_uint8 *start_bits, int cbit_type, unsigned int table_limit,
  compile_data *cd)
{
register pcre_uint32 c;
for (c = 0; c < table_limit; c++) start_bits[c] |= ~cd->cbits[c+cbit_type];
#if defined SUPPORT_UTF && defined COMPILE_PCRE8
if (table_limit != 32) for (c = 24; c < 32; c++) start_bits[c] = 0xff;
#endif
}



/*************************************************
*          Create bitmap of starting bytes       *
*************************************************/

/* This function scans a compiled unanchored expression recursively and
attempts to build a bitmap of the set of possible starting bytes. As time goes
by, we may be able to get more clever at doing this. The SSB_CONTINUE return is
useful for parenthesized groups in patterns such as (a*)b where the group
provides some optional starting bytes but scanning must continue at the outer
level to find at least one mandatory byte. At the outermost level, this
function fails unless the result is SSB_DONE.

Arguments:
  code         points to an expression
  start_bits   points to a 32-byte table, initialized to 0
  utf          TRUE if in UTF-8 / UTF-16 / UTF-32 mode
  cd           the block with char table pointers

Returns:       SSB_FAIL     => Failed to find any starting bytes
               SSB_DONE     => Found mandatory starting bytes
               SSB_CONTINUE => Found optional starting bytes
               SSB_UNKNOWN  => Hit an unrecognized opcode
*/

static int
set_start_bits(const pcre_uchar *code, pcre_uint8 *start_bits, BOOL utf,
  compile_data *cd)
{
register pcre_uint32 c;
int yield = SSB_DONE;
#if defined SUPPORT_UTF && defined COMPILE_PCRE8
int table_limit = utf? 16:32;
#else
int table_limit = 32;
#endif

#if 0
/* ========================================================================= */
/* The following comment and code was inserted in January 1999. In May 2006,
when it was observed to cause compiler warnings about unused values, I took it
out again. If anybody is still using OS/2, they will have to put it back
manually. */

/* This next statement and the later reference to dummy are here in order to
trick the optimizer of the IBM C compiler for OS/2 into generating correct
code. Apparently IBM isn't going to fix the problem, and we would rather not
disable optimization (in this module it actually makes a big difference, and
the pcre module can use all the optimization it can get). */

volatile int dummy;
/* ========================================================================= */
#endif

do
  {
  BOOL try_next = TRUE;
  const pcre_uchar *tcode = code + 1 + LINK_SIZE;

  if (*code == OP_CBRA || *code == OP_SCBRA ||
      *code == OP_CBRAPOS || *code == OP_SCBRAPOS) tcode += IMM2_SIZE;

  while (try_next)    /* Loop for items in this branch */
    {
    int rc;

    switch(*tcode)
      {
      /* If we reach something we don't understand, it means a new opcode has
      been created that hasn't been added to this code. Hopefully this problem
      will be discovered during testing. */

      default:
      return SSB_UNKNOWN;

      /* Fail for a valid opcode that implies no starting bits. */

      case OP_ACCEPT:
      case OP_ASSERT_ACCEPT:
      case OP_ALLANY:
      case OP_ANY:
      case OP_ANYBYTE:
      case OP_CIRC:
      case OP_CIRCM:
      case OP_CLOSE:
      case OP_COMMIT:
      case OP_COND:
      case OP_CREF:
      case OP_DEF:
      case OP_DNCREF:
      case OP_DNREF:
      case OP_DNREFI:
      case OP_DNRREF:
      case OP_DOLL:
      case OP_DOLLM:
      case OP_END:
      case OP_EOD:
      case OP_EODN:
      case OP_EXTUNI:
      case OP_FAIL:
      case OP_MARK:
      case OP_NOT:
      case OP_NOTEXACT:
      case OP_NOTEXACTI:
      case OP_NOTI:
      case OP_NOTMINPLUS:
      case OP_NOTMINPLUSI:
      case OP_NOTMINQUERY:
      case OP_NOTMINQUERYI:
      case OP_NOTMINSTAR:
      case OP_NOTMINSTARI:
      case OP_NOTMINUPTO:
      case OP_NOTMINUPTOI:
      case OP_NOTPLUS:
      case OP_NOTPLUSI:
      case OP_NOTPOSPLUS:
      case OP_NOTPOSPLUSI:
      case OP_NOTPOSQUERY:
      case OP_NOTPOSQUERYI:
      case OP_NOTPOSSTAR:
      case OP_NOTPOSSTARI:
      case OP_NOTPOSUPTO:
      case OP_NOTPOSUPTOI:
      case OP_NOTPROP:
      case OP_NOTQUERY:
      case OP_NOTQUERYI:
      case OP_NOTSTAR:
      case OP_NOTSTARI:
      case OP_NOTUPTO:
      case OP_NOTUPTOI:
      case OP_NOT_HSPACE:
      case OP_NOT_VSPACE:
      case OP_PRUNE:
      case OP_PRUNE_ARG:
      case OP_RECURSE:
      case OP_REF:
      case OP_REFI:
      case OP_REVERSE:
      case OP_RREF:
      case OP_SCOND:
      case OP_SET_SOM:
      case OP_SKIP:
      case OP_SKIP_ARG:
      case OP_SOD:
      case OP_SOM:
      case OP_THEN:
      case OP_THEN_ARG:
      return SSB_FAIL;

      /* A "real" property test implies no starting bits, but the fake property
      PT_CLIST identifies a list of characters. These lists are short, as they
      are used for characters with more than one "other case", so there is no
      point in recognizing them for OP_NOTPROP. */

      case OP_PROP:
      if (tcode[1] != PT_CLIST) return SSB_FAIL;
        {
        const pcre_uint32 *p = PRIV(ucd_caseless_sets) + tcode[2];
        while ((c = *p++) < NOTACHAR)
          {
#if defined SUPPORT_UTF && defined COMPILE_PCRE8
          if (utf)
            {
            pcre_uchar buff[6];
            (void)PRIV(ord2utf)(c, buff);
            c = buff[0];
            }
#endif
          if (c > 0xff) SET_BIT(0xff); else SET_BIT(c);
          }
        }
      try_next = FALSE;
      break;

      /* We can ignore word boundary tests. */

      case OP_WORD_BOUNDARY:
      case OP_NOT_WORD_BOUNDARY:
      tcode++;
      break;

      /* If we hit a bracket or a positive lookahead assertion, recurse to set
      bits from within the subpattern. If it can't find anything, we have to
      give up. If it finds some mandatory character(s), we are done for this
      branch. Otherwise, carry on scanning after the subpattern. */

      case OP_BRA:
      case OP_SBRA:
      case OP_CBRA:
      case OP_SCBRA:
      case OP_BRAPOS:
      case OP_SBRAPOS:
      case OP_CBRAPOS:
      case OP_SCBRAPOS:
      case OP_ONCE:
      case OP_ONCE_NC:
      case OP_ASSERT:
      rc = set_start_bits(tcode, start_bits, utf, cd);
      if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc;
      if (rc == SSB_DONE) try_next = FALSE; else
        {
        do tcode += GET(tcode, 1); while (*tcode == OP_ALT);
        tcode += 1 + LINK_SIZE;
        }
      break;

      /* If we hit ALT or KET, it means we haven't found anything mandatory in
      this branch, though we might have found something optional. For ALT, we
      continue with the next alternative, but we have to arrange that the final
      result from subpattern is SSB_CONTINUE rather than SSB_DONE. For KET,
      return SSB_CONTINUE: if this is the top level, that indicates failure,
      but after a nested subpattern, it causes scanning to continue. */

      case OP_ALT:
      yield = SSB_CONTINUE;
      try_next = FALSE;
      break;

      case OP_KET:
      case OP_KETRMAX:
      case OP_KETRMIN:
      case OP_KETRPOS:
      return SSB_CONTINUE;

      /* Skip over callout */

      case OP_CALLOUT:
      tcode += 2 + 2*LINK_SIZE;
      break;

      /* Skip over lookbehind and negative lookahead assertions */

      case OP_ASSERT_NOT:
      case OP_ASSERTBACK:
      case OP_ASSERTBACK_NOT:
      do tcode += GET(tcode, 1); while (*tcode == OP_ALT);
      tcode += 1 + LINK_SIZE;
      break;

      /* BRAZERO does the bracket, but carries on. */

      case OP_BRAZERO:
      case OP_BRAMINZERO:
      case OP_BRAPOSZERO:
      rc = set_start_bits(++tcode, start_bits, utf, cd);
      if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc;
/* =========================================================================
      See the comment at the head of this function concerning the next line,
      which was an old fudge for the benefit of OS/2.
      dummy = 1;
  ========================================================================= */
      do tcode += GET(tcode,1); while (*tcode == OP_ALT);
      tcode += 1 + LINK_SIZE;
      break;

      /* SKIPZERO skips the bracket. */

      case OP_SKIPZERO:
      tcode++;
      do tcode += GET(tcode,1); while (*tcode == OP_ALT);
      tcode += 1 + LINK_SIZE;
      break;

      /* Single-char * or ? sets the bit and tries the next item */

      case OP_STAR:
      case OP_MINSTAR:
      case OP_POSSTAR:
      case OP_QUERY:
      case OP_MINQUERY:
      case OP_POSQUERY:
      tcode = set_table_bit(start_bits, tcode + 1, FALSE, cd, utf);
      break;

      case OP_STARI:
      case OP_MINSTARI:
      case OP_POSSTARI:
      case OP_QUERYI:
      case OP_MINQUERYI:
      case OP_POSQUERYI:
      tcode = set_table_bit(start_bits, tcode + 1, TRUE, cd, utf);
      break;

      /* Single-char upto sets the bit and tries the next */

      case OP_UPTO:
      case OP_MINUPTO:
      case OP_POSUPTO:
      tcode = set_table_bit(start_bits, tcode + 1 + IMM2_SIZE, FALSE, cd, utf);
      break;

      case OP_UPTOI:
      case OP_MINUPTOI:
      case OP_POSUPTOI:
      tcode = set_table_bit(start_bits, tcode + 1 + IMM2_SIZE, TRUE, cd, utf);
      break;

      /* At least one single char sets the bit and stops */

      case OP_EXACT:
      tcode += IMM2_SIZE;
      /* Fall through */
      case OP_CHAR:
      case OP_PLUS:
      case OP_MINPLUS:
      case OP_POSPLUS:
      (void)set_table_bit(start_bits, tcode + 1, FALSE, cd, utf);
      try_next = FALSE;
      break;

      case OP_EXACTI:
      tcode += IMM2_SIZE;
      /* Fall through */
      case OP_CHARI:
      case OP_PLUSI:
      case OP_MINPLUSI:
      case OP_POSPLUSI:
      (void)set_table_bit(start_bits, tcode + 1, TRUE, cd, utf);
      try_next = FALSE;
      break;

      /* Special spacing and line-terminating items. These recognize specific
      lists of characters. The difference between VSPACE and ANYNL is that the
      latter can match the two-character CRLF sequence, but that is not
      relevant for finding the first character, so their code here is
      identical. */

      case OP_HSPACE:
      SET_BIT(CHAR_HT);
      SET_BIT(CHAR_SPACE);
#ifdef SUPPORT_UTF
      if (utf)
        {
#ifdef COMPILE_PCRE8
        SET_BIT(0xC2);  /* For U+00A0 */
        SET_BIT(0xE1);  /* For U+1680, U+180E */
        SET_BIT(0xE2);  /* For U+2000 - U+200A, U+202F, U+205F */
        SET_BIT(0xE3);  /* For U+3000 */
#elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32
        SET_BIT(0xA0);
        SET_BIT(0xFF);  /* For characters > 255 */
#endif  /* COMPILE_PCRE[8|16|32] */
        }
      else
#endif /* SUPPORT_UTF */
        {
#ifndef EBCDIC
        SET_BIT(0xA0);
#endif  /* Not EBCDIC */
#if defined COMPILE_PCRE16 || defined COMPILE_PCRE32
        SET_BIT(0xFF);  /* For characters > 255 */
#endif  /* COMPILE_PCRE[16|32] */
        }
      try_next = FALSE;
      break;

      case OP_ANYNL:
      case OP_VSPACE:
      SET_BIT(CHAR_LF);
      SET_BIT(CHAR_VT);
      SET_BIT(CHAR_FF);
      SET_BIT(CHAR_CR);
#ifdef SUPPORT_UTF
      if (utf)
        {
#ifdef COMPILE_PCRE8
        SET_BIT(0xC2);  /* For U+0085 */
        SET_BIT(0xE2);  /* For U+2028, U+2029 */
#elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32
        SET_BIT(CHAR_NEL);
        SET_BIT(0xFF);  /* For characters > 255 */
#endif  /* COMPILE_PCRE[8|16|32] */
        }
      else
#endif /* SUPPORT_UTF */
        {
        SET_BIT(CHAR_NEL);
#if defined COMPILE_PCRE16 || defined COMPILE_PCRE32
        SET_BIT(0xFF);  /* For characters > 255 */
#endif
        }
      try_next = FALSE;
      break;

      /* Single character types set the bits and stop. Note that if PCRE_UCP
      is set, we do not see these op codes because \d etc are converted to
      properties. Therefore, these apply in the case when only characters less
      than 256 are recognized to match the types. */

      case OP_NOT_DIGIT:
      set_nottype_bits(start_bits, cbit_digit, table_limit, cd);
      try_next = FALSE;
      break;

      case OP_DIGIT:
      set_type_bits(start_bits, cbit_digit, table_limit, cd);
      try_next = FALSE;
      break;

      /* The cbit_space table has vertical tab as whitespace; we no longer
      have to play fancy tricks because Perl added VT to its whitespace at
      release 5.18. PCRE added it at release 8.34. */

      case OP_NOT_WHITESPACE:
      set_nottype_bits(start_bits, cbit_space, table_limit, cd);
      try_next = FALSE;
      break;

      case OP_WHITESPACE:
      set_type_bits(start_bits, cbit_space, table_limit, cd);
      try_next = FALSE;
      break;

      case OP_NOT_WORDCHAR:
      set_nottype_bits(start_bits, cbit_word, table_limit, cd);
      try_next = FALSE;
      break;

      case OP_WORDCHAR:
      set_type_bits(start_bits, cbit_word, table_limit, cd);
      try_next = FALSE;
      break;

      /* One or more character type fudges the pointer and restarts, knowing
      it will hit a single character type and stop there. */

      case OP_TYPEPLUS:
      case OP_TYPEMINPLUS:
      case OP_TYPEPOSPLUS:
      tcode++;
      break;

      case OP_TYPEEXACT:
      tcode += 1 + IMM2_SIZE;
      break;

      /* Zero or more repeats of character types set the bits and then
      try again. */

      case OP_TYPEUPTO:
      case OP_TYPEMINUPTO:
      case OP_TYPEPOSUPTO:
      tcode += IMM2_SIZE;  /* Fall through */

      case OP_TYPESTAR:
      case OP_TYPEMINSTAR:
      case OP_TYPEPOSSTAR:
      case OP_TYPEQUERY:
      case OP_TYPEMINQUERY:
      case OP_TYPEPOSQUERY:
      switch(tcode[1])
        {
        default:
        case OP_ANY:
        case OP_ALLANY:
        return SSB_FAIL;

        case OP_HSPACE:
        SET_BIT(CHAR_HT);
        SET_BIT(CHAR_SPACE);
#ifdef SUPPORT_UTF
        if (utf)
          {
#ifdef COMPILE_PCRE8
          SET_BIT(0xC2);  /* For U+00A0 */
          SET_BIT(0xE1);  /* For U+1680, U+180E */
          SET_BIT(0xE2);  /* For U+2000 - U+200A, U+202F, U+205F */
          SET_BIT(0xE3);  /* For U+3000 */
#elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32
          SET_BIT(0xA0);
          SET_BIT(0xFF);  /* For characters > 255 */
#endif  /* COMPILE_PCRE[8|16|32] */
          }
        else
#endif /* SUPPORT_UTF */
#ifndef EBCDIC
          SET_BIT(0xA0);
#endif  /* Not EBCDIC */
        break;

        case OP_ANYNL:
        case OP_VSPACE:
        SET_BIT(CHAR_LF);
        SET_BIT(CHAR_VT);
        SET_BIT(CHAR_FF);
        SET_BIT(CHAR_CR);
#ifdef SUPPORT_UTF
        if (utf)
          {
#ifdef COMPILE_PCRE8
          SET_BIT(0xC2);  /* For U+0085 */
          SET_BIT(0xE2);  /* For U+2028, U+2029 */
#elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32
          SET_BIT(CHAR_NEL);
          SET_BIT(0xFF);  /* For characters > 255 */
#endif  /* COMPILE_PCRE16 */
          }
        else
#endif /* SUPPORT_UTF */
          SET_BIT(CHAR_NEL);
        break;

        case OP_NOT_DIGIT:
        set_nottype_bits(start_bits, cbit_digit, table_limit, cd);
        break;

        case OP_DIGIT:
        set_type_bits(start_bits, cbit_digit, table_limit, cd);
        break;

        /* The cbit_space table has vertical tab as whitespace; we no longer
        have to play fancy tricks because Perl added VT to its whitespace at
        release 5.18. PCRE added it at release 8.34. */

        case OP_NOT_WHITESPACE:
        set_nottype_bits(start_bits, cbit_space, table_limit, cd);
        break;

        case OP_WHITESPACE:
        set_type_bits(start_bits, cbit_space, table_limit, cd);
        break;

        case OP_NOT_WORDCHAR:
        set_nottype_bits(start_bits, cbit_word, table_limit, cd);
        break;

        case OP_WORDCHAR:
        set_type_bits(start_bits, cbit_word, table_limit, cd);
        break;
        }

      tcode += 2;
      break;

      /* Character class where all the information is in a bit map: set the
      bits and either carry on or not, according to the repeat count. If it was
      a negative class, and we are operating with UTF-8 characters, any byte
      with a value >= 0xc4 is a potentially valid starter because it starts a
      character with a value > 255. */

#if defined SUPPORT_UTF || !defined COMPILE_PCRE8
      case OP_XCLASS:
      if ((tcode[1 + LINK_SIZE] & XCL_HASPROP) != 0)
        return SSB_FAIL;
      /* All bits are set. */
      if ((tcode[1 + LINK_SIZE] & XCL_MAP) == 0 && (tcode[1 + LINK_SIZE] & XCL_NOT) != 0)
        return SSB_FAIL;
#endif
      /* Fall through */

      case OP_NCLASS:
#if defined SUPPORT_UTF && defined COMPILE_PCRE8
      if (utf)
        {
        start_bits[24] |= 0xf0;              /* Bits for 0xc4 - 0xc8 */
        memset(start_bits+25, 0xff, 7);      /* Bits for 0xc9 - 0xff */
        }
#endif
#if defined COMPILE_PCRE16 || defined COMPILE_PCRE32
      SET_BIT(0xFF);                         /* For characters > 255 */
#endif
      /* Fall through */

      case OP_CLASS:
        {
        pcre_uint8 *map;
#if defined SUPPORT_UTF || !defined COMPILE_PCRE8
        map = NULL;
        if (*tcode == OP_XCLASS)
          {
          if ((tcode[1 + LINK_SIZE] & XCL_MAP) != 0)
            map = (pcre_uint8 *)(tcode + 1 + LINK_SIZE + 1);
          tcode += GET(tcode, 1);
          }
        else
#endif
          {
          tcode++;
          map = (pcre_uint8 *)tcode;
          tcode += 32 / sizeof(pcre_uchar);
          }

        /* In UTF-8 mode, the bits in a bit map correspond to character
        values, not to byte values. However, the bit map we are constructing is
        for byte values. So we have to do a conversion for characters whose
        value is > 127. In fact, there are only two possible starting bytes for
        characters in the range 128 - 255. */

#if defined SUPPORT_UTF || !defined COMPILE_PCRE8
        if (map != NULL)
#endif
          {
#if defined SUPPORT_UTF && defined COMPILE_PCRE8
          if (utf)
            {
            for (c = 0; c < 16; c++) start_bits[c] |= map[c];
            for (c = 128; c < 256; c++)
              {
              if ((map[c/8] & (1 << (c&7))) != 0)
                {
                int d = (c >> 6) | 0xc0;            /* Set bit for this starter */
                start_bits[d/8] |= (1 << (d&7));    /* and then skip on to the */
                c = (c & 0xc0) + 0x40 - 1;          /* next relevant character. */
                }
              }
            }
          else
#endif
            {
            /* In non-UTF-8 mode, the two bit maps are completely compatible. */
            for (c = 0; c < 32; c++) start_bits[c] |= map[c];
            }
          }

        /* Advance past the bit map, and act on what follows. For a zero
        minimum repeat, continue; otherwise stop processing. */

        switch (*tcode)
          {
          case OP_CRSTAR:
          case OP_CRMINSTAR:
          case OP_CRQUERY:
          case OP_CRMINQUERY:
          case OP_CRPOSSTAR:
          case OP_CRPOSQUERY:
          tcode++;
          break;

          case OP_CRRANGE:
          case OP_CRMINRANGE:
          case OP_CRPOSRANGE:
          if (GET2(tcode, 1) == 0) tcode += 1 + 2 * IMM2_SIZE;
            else try_next = FALSE;
          break;

          default:
          try_next = FALSE;
          break;
          }
        }
      break; /* End of bitmap class handling */

      }      /* End of switch */
    }        /* End of try_next loop */

  code += GET(code, 1);   /* Advance to next branch */
  }
while (*code == OP_ALT);
return yield;
}





/*************************************************
*          Study a compiled expression           *
*************************************************/

/* This function is handed a compiled expression that it must study to produce
information that will speed up the matching. It returns a pcre[16]_extra block
which then gets handed back to pcre_exec().

Arguments:
  re        points to the compiled expression
  options   contains option bits
  errorptr  points to where to place error messages;
            set NULL unless error

Returns:    pointer to a pcre[16]_extra block, with study_data filled in and
              the appropriate flags set;
            NULL on error or if no optimization possible
*/

#if defined COMPILE_PCRE8
PCRE_EXP_DEFN pcre_extra * PCRE_CALL_CONVENTION
pcre_study(const pcre *external_re, int options, const char **errorptr)
#elif defined COMPILE_PCRE16
PCRE_EXP_DEFN pcre16_extra * PCRE_CALL_CONVENTION
pcre16_study(const pcre16 *external_re, int options, const char **errorptr)
#elif defined COMPILE_PCRE32
PCRE_EXP_DEFN pcre32_extra * PCRE_CALL_CONVENTION
pcre32_study(const pcre32 *external_re, int options, const char **errorptr)
#endif
{
int min;
int count = 0;
BOOL bits_set = FALSE;
pcre_uint8 start_bits[32];
PUBL(extra) *extra = NULL;
pcre_study_data *study;
const pcre_uint8 *tables;
pcre_uchar *code;
compile_data compile_block;
const REAL_PCRE *re = (const REAL_PCRE *)external_re;


*errorptr = NULL;

if (re == NULL || re->magic_number != MAGIC_NUMBER)
  {
  *errorptr = "argument is not a compiled regular expression";
  return NULL;
  }

if ((re->flags & PCRE_MODE) == 0)
  {
#if defined COMPILE_PCRE8
  *errorptr = "argument not compiled in 8 bit mode";
#elif defined COMPILE_PCRE16
  *errorptr = "argument not compiled in 16 bit mode";
#elif defined COMPILE_PCRE32
  *errorptr = "argument not compiled in 32 bit mode";
#endif
  return NULL;
  }

if ((options & ~PUBLIC_STUDY_OPTIONS) != 0)
  {
  *errorptr = "unknown or incorrect option bit(s) set";
  return NULL;
  }

code = (pcre_uchar *)re + re->name_table_offset +
  (re->name_count * re->name_entry_size);

/* For an anchored pattern, or an unanchored pattern that has a first char, or
a multiline pattern that matches only at "line starts", there is no point in
seeking a list of starting bytes. */

if ((re->options & PCRE_ANCHORED) == 0 &&
    (re->flags & (PCRE_FIRSTSET|PCRE_STARTLINE)) == 0)
  {
  int rc;

  /* Set the character tables in the block that is passed around */

  tables = re->tables;

#if defined COMPILE_PCRE8
  if (tables == NULL)
    (void)pcre_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,
    (void *)(&tables));
#elif defined COMPILE_PCRE16
  if (tables == NULL)
    (void)pcre16_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,
    (void *)(&tables));
#elif defined COMPILE_PCRE32
  if (tables == NULL)
    (void)pcre32_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,
    (void *)(&tables));
#endif

  compile_block.lcc = tables + lcc_offset;
  compile_block.fcc = tables + fcc_offset;
  compile_block.cbits = tables + cbits_offset;
  compile_block.ctypes = tables + ctypes_offset;

  /* See if we can find a fixed set of initial characters for the pattern. */

  memset(start_bits, 0, 32 * sizeof(pcre_uint8));
  rc = set_start_bits(code, start_bits, (re->options & PCRE_UTF8) != 0,
    &compile_block);
  bits_set = rc == SSB_DONE;
  if (rc == SSB_UNKNOWN)
    {
    *errorptr = "internal error: opcode not recognized";
    return NULL;
    }
  }

/* Find the minimum length of subject string. */

switch(min = find_minlength(re, code, code, re->options, NULL, &count))
  {
  case -2: *errorptr = "internal error: missing capturing bracket"; return NULL;
  case -3: *errorptr = "internal error: opcode not recognized"; return NULL;
  default: break;
  }

/* If a set of starting bytes has been identified, or if the minimum length is
greater than zero, or if JIT optimization has been requested, or if
PCRE_STUDY_EXTRA_NEEDED is set, get a pcre[16]_extra block and a
pcre_study_data block. The study data is put in the latter, which is pointed to
by the former, which may also get additional data set later by the calling
program. At the moment, the size of pcre_study_data is fixed. We nevertheless
save it in a field for returning via the pcre_fullinfo() function so that if it
becomes variable in the future, we don't have to change that code. */

if (bits_set || min > 0 || (options & (
#ifdef SUPPORT_JIT
    PCRE_STUDY_JIT_COMPILE | PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE |
    PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE |
#endif
    PCRE_STUDY_EXTRA_NEEDED)) != 0)
  {
  extra = (PUBL(extra) *)(PUBL(malloc))
    (sizeof(PUBL(extra)) + sizeof(pcre_study_data));
  if (extra == NULL)
    {
    *errorptr = "failed to get memory";
    return NULL;
    }

  study = (pcre_study_data *)((char *)extra + sizeof(PUBL(extra)));
  extra->flags = PCRE_EXTRA_STUDY_DATA;
  extra->study_data = study;

  study->size = sizeof(pcre_study_data);
  study->flags = 0;

  /* Set the start bits always, to avoid unset memory errors if the
  study data is written to a file, but set the flag only if any of the bits
  are set, to save time looking when none are. */

  if (bits_set)
    {
    study->flags |= PCRE_STUDY_MAPPED;
    memcpy(study->start_bits, start_bits, sizeof(start_bits));
    }
  else memset(study->start_bits, 0, 32 * sizeof(pcre_uint8));

#ifdef PCRE_DEBUG
  if (bits_set)
    {
    pcre_uint8 *ptr = start_bits;
    int i;

    printf("Start bits:\n");
    for (i = 0; i < 32; i++)
      printf("%3d: %02x%s", i * 8, *ptr++, ((i + 1) & 0x7) != 0? " " : "\n");
    }
#endif

  /* Always set the minlength value in the block, because the JIT compiler
  makes use of it. However, don't set the bit unless the length is greater than
  zero - the interpretive pcre_exec() and pcre_dfa_exec() needn't waste time
  checking the zero case. */

  if (min > 0)
    {
    study->flags |= PCRE_STUDY_MINLEN;
    study->minlength = min;
    }
  else study->minlength = 0;

  /* If JIT support was compiled and requested, attempt the JIT compilation.
  If no starting bytes were found, and the minimum length is zero, and JIT
  compilation fails, abandon the extra block and return NULL, unless
  PCRE_STUDY_EXTRA_NEEDED is set. */

#ifdef SUPPORT_JIT
  extra->executable_jit = NULL;
  if ((options & PCRE_STUDY_JIT_COMPILE) != 0)
    PRIV(jit_compile)(re, extra, JIT_COMPILE);
  if ((options & PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE) != 0)
    PRIV(jit_compile)(re, extra, JIT_PARTIAL_SOFT_COMPILE);
  if ((options & PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE) != 0)
    PRIV(jit_compile)(re, extra, JIT_PARTIAL_HARD_COMPILE);

  if (study->flags == 0 && (extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) == 0 &&
      (options & PCRE_STUDY_EXTRA_NEEDED) == 0)
    {
#if defined COMPILE_PCRE8
    pcre_free_study(extra);
#elif defined COMPILE_PCRE16
    pcre16_free_study(extra);
#elif defined COMPILE_PCRE32
    pcre32_free_study(extra);
#endif
    extra = NULL;
    }
#endif
  }

return extra;
}


/*************************************************
*          Free the study data                   *
*************************************************/

/* This function frees the memory that was obtained by pcre_study().

Argument:   a pointer to the pcre[16]_extra block
Returns:    nothing
*/

#if defined COMPILE_PCRE8
PCRE_EXP_DEFN void
pcre_free_study(pcre_extra *extra)
#elif defined COMPILE_PCRE16
PCRE_EXP_DEFN void
pcre16_free_study(pcre16_extra *extra)
#elif defined COMPILE_PCRE32
PCRE_EXP_DEFN void
pcre32_free_study(pcre32_extra *extra)
#endif
{
if (extra == NULL)
  return;
#ifdef SUPPORT_JIT
if ((extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) != 0 &&
     extra->executable_jit != NULL)
  PRIV(jit_free)(extra->executable_jit);
#endif
PUBL(free)(extra);
}

/* End of pcre_study.c */