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
|
/* $OpenBSD: dfa.c,v 1.4 2001/06/17 07:30:42 deraadt Exp $ */
/* dfa - DFA construction routines */
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Vern Paxson.
*
* The United States Government has rights in this work pursuant
* to contract no. DE-AC03-76SF00098 between the United States
* Department of Energy and the University of California.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source distributions
* retain this entire copyright notice and comment, and (2) distributions
* including binaries display the following acknowledgement: ``This product
* includes software developed by the University of California, Berkeley
* and its contributors'' in the documentation or other materials provided
* with the distribution and in all advertising materials mentioning
* features or use of this software. Neither the name of the University 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
/* $Header: /cvs/OpenBSD/src/usr.bin/lex/dfa.c,v 1.4 2001/06/17 07:30:42 deraadt Exp $ */
#include "flexdef.h"
/* declare functions that have forward references */
void dump_associated_rules PROTO((FILE*, int));
void dump_transitions PROTO((FILE*, int[]));
void sympartition PROTO((int[], int, int[], int[]));
int symfollowset PROTO((int[], int, int, int[]));
/* check_for_backing_up - check a DFA state for backing up
*
* synopsis
* void check_for_backing_up( int ds, int state[numecs] );
*
* ds is the number of the state to check and state[] is its out-transitions,
* indexed by equivalence class.
*/
void check_for_backing_up( ds, state )
int ds;
int state[];
{
if ( (reject && ! dfaacc[ds].dfaacc_set) ||
(! reject && ! dfaacc[ds].dfaacc_state) )
{ /* state is non-accepting */
++num_backing_up;
if ( backing_up_report )
{
fprintf( backing_up_file,
_( "State #%d is non-accepting -\n" ), ds );
/* identify the state */
dump_associated_rules( backing_up_file, ds );
/* Now identify it further using the out- and
* jam-transitions.
*/
dump_transitions( backing_up_file, state );
putc( '\n', backing_up_file );
}
}
}
/* check_trailing_context - check to see if NFA state set constitutes
* "dangerous" trailing context
*
* synopsis
* void check_trailing_context( int nfa_states[num_states+1], int num_states,
* int accset[nacc+1], int nacc );
*
* NOTES
* Trailing context is "dangerous" if both the head and the trailing
* part are of variable size \and/ there's a DFA state which contains
* both an accepting state for the head part of the rule and NFA states
* which occur after the beginning of the trailing context.
*
* When such a rule is matched, it's impossible to tell if having been
* in the DFA state indicates the beginning of the trailing context or
* further-along scanning of the pattern. In these cases, a warning
* message is issued.
*
* nfa_states[1 .. num_states] is the list of NFA states in the DFA.
* accset[1 .. nacc] is the list of accepting numbers for the DFA state.
*/
void check_trailing_context( nfa_states, num_states, accset, nacc )
int *nfa_states, num_states;
int *accset;
int nacc;
{
register int i, j;
for ( i = 1; i <= num_states; ++i )
{
int ns = nfa_states[i];
register int type = state_type[ns];
register int ar = assoc_rule[ns];
if ( type == STATE_NORMAL || rule_type[ar] != RULE_VARIABLE )
{ /* do nothing */
}
else if ( type == STATE_TRAILING_CONTEXT )
{
/* Potential trouble. Scan set of accepting numbers
* for the one marking the end of the "head". We
* assume that this looping will be fairly cheap
* since it's rare that an accepting number set
* is large.
*/
for ( j = 1; j <= nacc; ++j )
if ( accset[j] & YY_TRAILING_HEAD_MASK )
{
line_warning(
_( "dangerous trailing context" ),
rule_linenum[ar] );
return;
}
}
}
}
/* dump_associated_rules - list the rules associated with a DFA state
*
* Goes through the set of NFA states associated with the DFA and
* extracts the first MAX_ASSOC_RULES unique rules, sorts them,
* and writes a report to the given file.
*/
void dump_associated_rules( file, ds )
FILE *file;
int ds;
{
register int i, j;
register int num_associated_rules = 0;
int rule_set[MAX_ASSOC_RULES + 1];
int *dset = dss[ds];
int size = dfasiz[ds];
for ( i = 1; i <= size; ++i )
{
register int rule_num = rule_linenum[assoc_rule[dset[i]]];
for ( j = 1; j <= num_associated_rules; ++j )
if ( rule_num == rule_set[j] )
break;
if ( j > num_associated_rules )
{ /* new rule */
if ( num_associated_rules < MAX_ASSOC_RULES )
rule_set[++num_associated_rules] = rule_num;
}
}
bubble( rule_set, num_associated_rules );
fprintf( file, _( " associated rule line numbers:" ) );
for ( i = 1; i <= num_associated_rules; ++i )
{
if ( i % 8 == 1 )
putc( '\n', file );
fprintf( file, "\t%d", rule_set[i] );
}
putc( '\n', file );
}
/* dump_transitions - list the transitions associated with a DFA state
*
* synopsis
* dump_transitions( FILE *file, int state[numecs] );
*
* Goes through the set of out-transitions and lists them in human-readable
* form (i.e., not as equivalence classes); also lists jam transitions
* (i.e., all those which are not out-transitions, plus EOF). The dump
* is done to the given file.
*/
void dump_transitions( file, state )
FILE *file;
int state[];
{
register int i, ec;
int out_char_set[CSIZE];
for ( i = 0; i < csize; ++i )
{
ec = ABS( ecgroup[i] );
out_char_set[i] = state[ec];
}
fprintf( file, _( " out-transitions: " ) );
list_character_set( file, out_char_set );
/* now invert the members of the set to get the jam transitions */
for ( i = 0; i < csize; ++i )
out_char_set[i] = ! out_char_set[i];
fprintf( file, _( "\n jam-transitions: EOF " ) );
list_character_set( file, out_char_set );
putc( '\n', file );
}
/* epsclosure - construct the epsilon closure of a set of ndfa states
*
* synopsis
* int *epsclosure( int t[num_states], int *numstates_addr,
* int accset[num_rules+1], int *nacc_addr,
* int *hashval_addr );
*
* NOTES
* The epsilon closure is the set of all states reachable by an arbitrary
* number of epsilon transitions, which themselves do not have epsilon
* transitions going out, unioned with the set of states which have non-null
* accepting numbers. t is an array of size numstates of nfa state numbers.
* Upon return, t holds the epsilon closure and *numstates_addr is updated.
* accset holds a list of the accepting numbers, and the size of accset is
* given by *nacc_addr. t may be subjected to reallocation if it is not
* large enough to hold the epsilon closure.
*
* hashval is the hash value for the dfa corresponding to the state set.
*/
int *epsclosure( t, ns_addr, accset, nacc_addr, hv_addr )
int *t, *ns_addr, accset[], *nacc_addr, *hv_addr;
{
register int stkpos, ns, tsp;
int numstates = *ns_addr, nacc, hashval, transsym, nfaccnum;
int stkend, nstate;
static int did_stk_init = false, *stk;
#define MARK_STATE(state) \
trans1[state] = trans1[state] - MARKER_DIFFERENCE;
#define IS_MARKED(state) (trans1[state] < 0)
#define UNMARK_STATE(state) \
trans1[state] = trans1[state] + MARKER_DIFFERENCE;
#define CHECK_ACCEPT(state) \
{ \
nfaccnum = accptnum[state]; \
if ( nfaccnum != NIL ) \
accset[++nacc] = nfaccnum; \
}
#define DO_REALLOCATION \
{ \
current_max_dfa_size += MAX_DFA_SIZE_INCREMENT; \
++num_reallocs; \
t = reallocate_integer_array( t, current_max_dfa_size ); \
stk = reallocate_integer_array( stk, current_max_dfa_size ); \
} \
#define PUT_ON_STACK(state) \
{ \
if ( ++stkend >= current_max_dfa_size ) \
DO_REALLOCATION \
stk[stkend] = state; \
MARK_STATE(state) \
}
#define ADD_STATE(state) \
{ \
if ( ++numstates >= current_max_dfa_size ) \
DO_REALLOCATION \
t[numstates] = state; \
hashval += state; \
}
#define STACK_STATE(state) \
{ \
PUT_ON_STACK(state) \
CHECK_ACCEPT(state) \
if ( nfaccnum != NIL || transchar[state] != SYM_EPSILON ) \
ADD_STATE(state) \
}
if ( ! did_stk_init )
{
stk = allocate_integer_array( current_max_dfa_size );
did_stk_init = true;
}
nacc = stkend = hashval = 0;
for ( nstate = 1; nstate <= numstates; ++nstate )
{
ns = t[nstate];
/* The state could be marked if we've already pushed it onto
* the stack.
*/
if ( ! IS_MARKED(ns) )
{
PUT_ON_STACK(ns)
CHECK_ACCEPT(ns)
hashval += ns;
}
}
for ( stkpos = 1; stkpos <= stkend; ++stkpos )
{
ns = stk[stkpos];
transsym = transchar[ns];
if ( transsym == SYM_EPSILON )
{
tsp = trans1[ns] + MARKER_DIFFERENCE;
if ( tsp != NO_TRANSITION )
{
if ( ! IS_MARKED(tsp) )
STACK_STATE(tsp)
tsp = trans2[ns];
if ( tsp != NO_TRANSITION && ! IS_MARKED(tsp) )
STACK_STATE(tsp)
}
}
}
/* Clear out "visit" markers. */
for ( stkpos = 1; stkpos <= stkend; ++stkpos )
{
if ( IS_MARKED(stk[stkpos]) )
UNMARK_STATE(stk[stkpos])
else
flexfatal(
_( "consistency check failed in epsclosure()" ) );
}
*ns_addr = numstates;
*hv_addr = hashval;
*nacc_addr = nacc;
return t;
}
/* increase_max_dfas - increase the maximum number of DFAs */
void increase_max_dfas()
{
current_max_dfas += MAX_DFAS_INCREMENT;
++num_reallocs;
base = reallocate_integer_array( base, current_max_dfas );
def = reallocate_integer_array( def, current_max_dfas );
dfasiz = reallocate_integer_array( dfasiz, current_max_dfas );
accsiz = reallocate_integer_array( accsiz, current_max_dfas );
dhash = reallocate_integer_array( dhash, current_max_dfas );
dss = reallocate_int_ptr_array( dss, current_max_dfas );
dfaacc = reallocate_dfaacc_union( dfaacc, current_max_dfas );
if ( nultrans )
nultrans =
reallocate_integer_array( nultrans, current_max_dfas );
}
/* ntod - convert an ndfa to a dfa
*
* Creates the dfa corresponding to the ndfa we've constructed. The
* dfa starts out in state #1.
*/
void ntod()
{
int *accset, ds, nacc, newds;
int sym, hashval, numstates, dsize;
int num_full_table_rows; /* used only for -f */
int *nset, *dset;
int targptr, totaltrans, i, comstate, comfreq, targ;
int symlist[CSIZE + 1];
int num_start_states;
int todo_head, todo_next;
/* Note that the following are indexed by *equivalence classes*
* and not by characters. Since equivalence classes are indexed
* beginning with 1, even if the scanner accepts NUL's, this
* means that (since every character is potentially in its own
* equivalence class) these arrays must have room for indices
* from 1 to CSIZE, so their size must be CSIZE + 1.
*/
int duplist[CSIZE + 1], state[CSIZE + 1];
int targfreq[CSIZE + 1], targstate[CSIZE + 1];
accset = allocate_integer_array( num_rules + 1 );
nset = allocate_integer_array( current_max_dfa_size );
/* The "todo" queue is represented by the head, which is the DFA
* state currently being processed, and the "next", which is the
* next DFA state number available (not in use). We depend on the
* fact that snstods() returns DFA's \in increasing order/, and thus
* need only know the bounds of the dfas to be processed.
*/
todo_head = todo_next = 0;
for ( i = 0; i <= csize; ++i )
{
duplist[i] = NIL;
symlist[i] = false;
}
for ( i = 0; i <= num_rules; ++i )
accset[i] = NIL;
if ( trace )
{
dumpnfa( scset[1] );
fputs( _( "\n\nDFA Dump:\n\n" ), stderr );
}
inittbl();
/* Check to see whether we should build a separate table for
* transitions on NUL characters. We don't do this for full-speed
* (-F) scanners, since for them we don't have a simple state
* number lying around with which to index the table. We also
* don't bother doing it for scanners unless (1) NUL is in its own
* equivalence class (indicated by a positive value of
* ecgroup[NUL]), (2) NUL's equivalence class is the last
* equivalence class, and (3) the number of equivalence classes is
* the same as the number of characters. This latter case comes
* about when useecs is false or when it's true but every character
* still manages to land in its own class (unlikely, but it's
* cheap to check for). If all these things are true then the
* character code needed to represent NUL's equivalence class for
* indexing the tables is going to take one more bit than the
* number of characters, and therefore we won't be assured of
* being able to fit it into a YY_CHAR variable. This rules out
* storing the transitions in a compressed table, since the code
* for interpreting them uses a YY_CHAR variable (perhaps it
* should just use an integer, though; this is worth pondering ...
* ###).
*
* Finally, for full tables, we want the number of entries in the
* table to be a power of two so the array references go fast (it
* will just take a shift to compute the major index). If
* encoding NUL's transitions in the table will spoil this, we
* give it its own table (note that this will be the case if we're
* not using equivalence classes).
*/
/* Note that the test for ecgroup[0] == numecs below accomplishes
* both (1) and (2) above
*/
if ( ! fullspd && ecgroup[0] == numecs )
{
/* NUL is alone in its equivalence class, which is the
* last one.
*/
int use_NUL_table = (numecs == csize);
if ( fulltbl && ! use_NUL_table )
{
/* We still may want to use the table if numecs
* is a power of 2.
*/
int power_of_two;
for ( power_of_two = 1; power_of_two <= csize;
power_of_two *= 2 )
if ( numecs == power_of_two )
{
use_NUL_table = true;
break;
}
}
if ( use_NUL_table )
nultrans = allocate_integer_array( current_max_dfas );
/* From now on, nultrans != nil indicates that we're
* saving null transitions for later, separate encoding.
*/
}
if ( fullspd )
{
for ( i = 0; i <= numecs; ++i )
state[i] = 0;
place_state( state, 0, 0 );
dfaacc[0].dfaacc_state = 0;
}
else if ( fulltbl )
{
if ( nultrans )
/* We won't be including NUL's transitions in the
* table, so build it for entries from 0 .. numecs - 1.
*/
num_full_table_rows = numecs;
else
/* Take into account the fact that we'll be including
* the NUL entries in the transition table. Build it
* from 0 .. numecs.
*/
num_full_table_rows = numecs + 1;
/* Unless -Ca, declare it "short" because it's a real
* long-shot that that won't be large enough.
*/
out_str_dec( "static yyconst %s yy_nxt[][%d] =\n {\n",
/* '}' so vi doesn't get too confused */
long_align ? "long" : "short", num_full_table_rows );
outn( " {" );
/* Generate 0 entries for state #0. */
for ( i = 0; i < num_full_table_rows; ++i )
mk2data( 0 );
dataflush();
outn( " },\n" );
}
/* Create the first states. */
num_start_states = lastsc * 2;
for ( i = 1; i <= num_start_states; ++i )
{
numstates = 1;
/* For each start condition, make one state for the case when
* we're at the beginning of the line (the '^' operator) and
* one for the case when we're not.
*/
if ( i % 2 == 1 )
nset[numstates] = scset[(i / 2) + 1];
else
nset[numstates] =
mkbranch( scbol[i / 2], scset[i / 2] );
nset = epsclosure( nset, &numstates, accset, &nacc, &hashval );
if ( snstods( nset, numstates, accset, nacc, hashval, &ds ) )
{
numas += nacc;
totnst += numstates;
++todo_next;
if ( variable_trailing_context_rules && nacc > 0 )
check_trailing_context( nset, numstates,
accset, nacc );
}
}
if ( ! fullspd )
{
if ( ! snstods( nset, 0, accset, 0, 0, &end_of_buffer_state ) )
flexfatal(
_( "could not create unique end-of-buffer state" ) );
++numas;
++num_start_states;
++todo_next;
}
while ( todo_head < todo_next )
{
targptr = 0;
totaltrans = 0;
for ( i = 1; i <= numecs; ++i )
state[i] = 0;
ds = ++todo_head;
dset = dss[ds];
dsize = dfasiz[ds];
if ( trace )
fprintf( stderr, _( "state # %d:\n" ), ds );
sympartition( dset, dsize, symlist, duplist );
for ( sym = 1; sym <= numecs; ++sym )
{
if ( symlist[sym] )
{
symlist[sym] = 0;
if ( duplist[sym] == NIL )
{
/* Symbol has unique out-transitions. */
numstates = symfollowset( dset, dsize,
sym, nset );
nset = epsclosure( nset, &numstates,
accset, &nacc, &hashval );
if ( snstods( nset, numstates, accset,
nacc, hashval, &newds ) )
{
totnst = totnst + numstates;
++todo_next;
numas += nacc;
if (
variable_trailing_context_rules &&
nacc > 0 )
check_trailing_context(
nset, numstates,
accset, nacc );
}
state[sym] = newds;
if ( trace )
fprintf( stderr, "\t%d\t%d\n",
sym, newds );
targfreq[++targptr] = 1;
targstate[targptr] = newds;
++numuniq;
}
else
{
/* sym's equivalence class has the same
* transitions as duplist(sym)'s
* equivalence class.
*/
targ = state[duplist[sym]];
state[sym] = targ;
if ( trace )
fprintf( stderr, "\t%d\t%d\n",
sym, targ );
/* Update frequency count for
* destination state.
*/
i = 0;
while ( targstate[++i] != targ )
;
++targfreq[i];
++numdup;
}
++totaltrans;
duplist[sym] = NIL;
}
}
if ( caseins && ! useecs )
{
register int j;
for ( i = 'A', j = 'a'; i <= 'Z'; ++i, ++j )
{
if ( state[i] == 0 && state[j] != 0 )
/* We're adding a transition. */
++totaltrans;
else if ( state[i] != 0 && state[j] == 0 )
/* We're taking away a transition. */
--totaltrans;
state[i] = state[j];
}
}
numsnpairs += totaltrans;
if ( ds > num_start_states )
check_for_backing_up( ds, state );
if ( nultrans )
{
nultrans[ds] = state[NUL_ec];
state[NUL_ec] = 0; /* remove transition */
}
if ( fulltbl )
{
outn( " {" );
/* Supply array's 0-element. */
if ( ds == end_of_buffer_state )
mk2data( -end_of_buffer_state );
else
mk2data( end_of_buffer_state );
for ( i = 1; i < num_full_table_rows; ++i )
/* Jams are marked by negative of state
* number.
*/
mk2data( state[i] ? state[i] : -ds );
dataflush();
outn( " },\n" );
}
else if ( fullspd )
place_state( state, ds, totaltrans );
else if ( ds == end_of_buffer_state )
/* Special case this state to make sure it does what
* it's supposed to, i.e., jam on end-of-buffer.
*/
stack1( ds, 0, 0, JAMSTATE );
else /* normal, compressed state */
{
/* Determine which destination state is the most
* common, and how many transitions to it there are.
*/
comfreq = 0;
comstate = 0;
for ( i = 1; i <= targptr; ++i )
if ( targfreq[i] > comfreq )
{
comfreq = targfreq[i];
comstate = targstate[i];
}
bldtbl( state, ds, totaltrans, comstate, comfreq );
}
}
if ( fulltbl )
dataend();
else if ( ! fullspd )
{
cmptmps(); /* create compressed template entries */
/* Create tables for all the states with only one
* out-transition.
*/
while ( onesp > 0 )
{
mk1tbl( onestate[onesp], onesym[onesp], onenext[onesp],
onedef[onesp] );
--onesp;
}
mkdeftbl();
}
flex_free( (void *) accset );
flex_free( (void *) nset );
}
/* snstods - converts a set of ndfa states into a dfa state
*
* synopsis
* is_new_state = snstods( int sns[numstates], int numstates,
* int accset[num_rules+1], int nacc,
* int hashval, int *newds_addr );
*
* On return, the dfa state number is in newds.
*/
int snstods( sns, numstates, accset, nacc, hashval, newds_addr )
int sns[], numstates, accset[], nacc, hashval, *newds_addr;
{
int didsort = 0;
register int i, j;
int newds, *oldsns;
for ( i = 1; i <= lastdfa; ++i )
if ( hashval == dhash[i] )
{
if ( numstates == dfasiz[i] )
{
oldsns = dss[i];
if ( ! didsort )
{
/* We sort the states in sns so we
* can compare it to oldsns quickly.
* We use bubble because there probably
* aren't very many states.
*/
bubble( sns, numstates );
didsort = 1;
}
for ( j = 1; j <= numstates; ++j )
if ( sns[j] != oldsns[j] )
break;
if ( j > numstates )
{
++dfaeql;
*newds_addr = i;
return 0;
}
++hshcol;
}
else
++hshsave;
}
/* Make a new dfa. */
if ( ++lastdfa >= current_max_dfas )
increase_max_dfas();
newds = lastdfa;
dss[newds] = allocate_integer_array( numstates + 1 );
/* If we haven't already sorted the states in sns, we do so now,
* so that future comparisons with it can be made quickly.
*/
if ( ! didsort )
bubble( sns, numstates );
for ( i = 1; i <= numstates; ++i )
dss[newds][i] = sns[i];
dfasiz[newds] = numstates;
dhash[newds] = hashval;
if ( nacc == 0 )
{
if ( reject )
dfaacc[newds].dfaacc_set = (int *) 0;
else
dfaacc[newds].dfaacc_state = 0;
accsiz[newds] = 0;
}
else if ( reject )
{
/* We sort the accepting set in increasing order so the
* disambiguating rule that the first rule listed is considered
* match in the event of ties will work. We use a bubble
* sort since the list is probably quite small.
*/
bubble( accset, nacc );
dfaacc[newds].dfaacc_set = allocate_integer_array( nacc + 1 );
/* Save the accepting set for later */
for ( i = 1; i <= nacc; ++i )
{
dfaacc[newds].dfaacc_set[i] = accset[i];
if ( accset[i] <= num_rules )
/* Who knows, perhaps a REJECT can yield
* this rule.
*/
rule_useful[accset[i]] = true;
}
accsiz[newds] = nacc;
}
else
{
/* Find lowest numbered rule so the disambiguating rule
* will work.
*/
j = num_rules + 1;
for ( i = 1; i <= nacc; ++i )
if ( accset[i] < j )
j = accset[i];
dfaacc[newds].dfaacc_state = j;
if ( j <= num_rules )
rule_useful[j] = true;
}
*newds_addr = newds;
return 1;
}
/* symfollowset - follow the symbol transitions one step
*
* synopsis
* numstates = symfollowset( int ds[current_max_dfa_size], int dsize,
* int transsym, int nset[current_max_dfa_size] );
*/
int symfollowset( ds, dsize, transsym, nset )
int ds[], dsize, transsym, nset[];
{
int ns, tsp, sym, i, j, lenccl, ch, numstates, ccllist;
numstates = 0;
for ( i = 1; i <= dsize; ++i )
{ /* for each nfa state ns in the state set of ds */
ns = ds[i];
sym = transchar[ns];
tsp = trans1[ns];
if ( sym < 0 )
{ /* it's a character class */
sym = -sym;
ccllist = cclmap[sym];
lenccl = ccllen[sym];
if ( cclng[sym] )
{
for ( j = 0; j < lenccl; ++j )
{
/* Loop through negated character
* class.
*/
ch = ccltbl[ccllist + j];
if ( ch == 0 )
ch = NUL_ec;
if ( ch > transsym )
/* Transsym isn't in negated
* ccl.
*/
break;
else if ( ch == transsym )
/* next 2 */ goto bottom;
}
/* Didn't find transsym in ccl. */
nset[++numstates] = tsp;
}
else
for ( j = 0; j < lenccl; ++j )
{
ch = ccltbl[ccllist + j];
if ( ch == 0 )
ch = NUL_ec;
if ( ch > transsym )
break;
else if ( ch == transsym )
{
nset[++numstates] = tsp;
break;
}
}
}
else if ( sym >= 'A' && sym <= 'Z' && caseins )
flexfatal(
_( "consistency check failed in symfollowset" ) );
else if ( sym == SYM_EPSILON )
{ /* do nothing */
}
else if ( ABS( ecgroup[sym] ) == transsym )
nset[++numstates] = tsp;
bottom: ;
}
return numstates;
}
/* sympartition - partition characters with same out-transitions
*
* synopsis
* sympartition( int ds[current_max_dfa_size], int numstates,
* int symlist[numecs], int duplist[numecs] );
*/
void sympartition( ds, numstates, symlist, duplist )
int ds[], numstates;
int symlist[], duplist[];
{
int tch, i, j, k, ns, dupfwd[CSIZE + 1], lenccl, cclp, ich;
/* Partitioning is done by creating equivalence classes for those
* characters which have out-transitions from the given state. Thus
* we are really creating equivalence classes of equivalence classes.
*/
for ( i = 1; i <= numecs; ++i )
{ /* initialize equivalence class list */
duplist[i] = i - 1;
dupfwd[i] = i + 1;
}
duplist[1] = NIL;
dupfwd[numecs] = NIL;
for ( i = 1; i <= numstates; ++i )
{
ns = ds[i];
tch = transchar[ns];
if ( tch != SYM_EPSILON )
{
if ( tch < -lastccl || tch >= csize )
{
flexfatal(
_( "bad transition character detected in sympartition()" ) );
}
if ( tch >= 0 )
{ /* character transition */
int ec = ecgroup[tch];
mkechar( ec, dupfwd, duplist );
symlist[ec] = 1;
}
else
{ /* character class */
tch = -tch;
lenccl = ccllen[tch];
cclp = cclmap[tch];
mkeccl( ccltbl + cclp, lenccl, dupfwd,
duplist, numecs, NUL_ec );
if ( cclng[tch] )
{
j = 0;
for ( k = 0; k < lenccl; ++k )
{
ich = ccltbl[cclp + k];
if ( ich == 0 )
ich = NUL_ec;
for ( ++j; j < ich; ++j )
symlist[j] = 1;
}
for ( ++j; j <= numecs; ++j )
symlist[j] = 1;
}
else
for ( k = 0; k < lenccl; ++k )
{
ich = ccltbl[cclp + k];
if ( ich == 0 )
ich = NUL_ec;
symlist[ich] = 1;
}
}
}
}
}
|