-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathregular.c
2007 lines (1890 loc) · 78.4 KB
/
regular.c
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
/*
Copyright (C) 1997-2016 Vladimir Makarov.
Written by Vladimir Makarov <[email protected]>
This file is part of the tool MSTA.
This is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This software is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.
*/
/* Make equivalent reduces???? Case ouput regular arc action which
corresponds shift and reducing by empty rule???? Additional
criteria of regular arcs equivalence is absence of $n when n
<=0???? */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* #ifdef HAVE_CONFIG_H */
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "position.h"
#include "vlobject.h"
#include "ticker.h"
#include "common.h"
#include "ird.h"
#include "gen-comm.h"
#include "output.h"
#include "contexts.h"
#include "lr-sets.h"
#include "regular.h"
#include <assert.h>
/* The following function returns TRUE iff given LR-set has only one
action which is reduce. */
static int
LR_set_has_only_one_action_reduce (IR_node_t LR_set,
IR_node_t *fold_LR_situation)
{
IR_node_t current_LR_situation;
int reduce_situations_number;
assert (IR_reachable_flag (LR_set));
reduce_situations_number = 0;
for (current_LR_situation = IR_LR_situation_list (LR_set);
current_LR_situation != NULL;
current_LR_situation = IR_next_LR_situation (current_LR_situation))
if (IR_IS_OF_TYPE (IR_element_after_dot (current_LR_situation),
IR_NM_canonical_rule_end))
{
/* Except for axiom rule. */
if (IR_canonical_rule (IR_element_after_dot (current_LR_situation))
== IR_canonical_rule_list (description)
|| reduce_situations_number != 0)
return FALSE;
*fold_LR_situation = current_LR_situation;
reduce_situations_number++;
}
else if (IR_IS_OF_TYPE
(IR_element_itself (IR_element_after_dot (current_LR_situation)),
IR_NM_single_term_definition))
return FALSE;
return TRUE;
}
/* The following variable value is TRUE iff look ahead context being
checked contains token strings of one length. */
static int one_length_token_strings_flag;
static void
check_token_string_length (token_string_t token_string)
{
if (one_length_token_strings_flag)
one_length_token_strings_flag = token_string_length (token_string) <= 1;
}
/* The following function returns TRUE iff given LR-situation has
look-ahead contexts of no more one length. */
static int
look_ahead_contexts_contain_only_tokens (IR_node_t LR_situation)
{
one_length_token_strings_flag = TRUE;
/* See comments in file `ird.sprut'. */
assert (IR_first_symbol_LR_situation (LR_situation));
if (IR_look_ahead_context (LR_situation) != NULL)
process_context_token_strings
(IR_look_ahead_context (LR_situation), check_token_string_length);
return one_length_token_strings_flag;
}
/* The following variable is used for counting number of LR-set
predecessors (see function `count_LR_set_predecessors'). */
static int LR_set_predecessors_number;
/* The following function is used through function
`traverse_all_LR_set_predecessors' for counting number of LR-set
predecessors of a LR-set. */
static int
count_LR_set_predecessors (IR_node_t LR_set)
{
LR_set_predecessors_number++;
return TRUE;
}
/* The following function is used through function
`traverse_all_LR_set_predecessors' for marking LR-sets which
will be in the state stack. */
static int
mark_LR_set_as_pushed (IR_node_t LR_set)
{
IR_set_it_is_pushed_LR_set (LR_set, TRUE);
assert (IR_reachable_flag (LR_set));
return TRUE;
}
/* The following function is used for creation and adding rule list
element with given canonical rule to given regular arc. */
static void
add_rule_list_element (IR_node_t regular_arc,
IR_node_t reduced_canonical_rule)
{
if (IR_first_rule_list_element (regular_arc) == NULL)
{
IR_set_first_rule_list_element
(regular_arc,
IR_new_rule_list_element (reduced_canonical_rule, NULL));
IR_set_last_rule_list_element
(regular_arc, IR_first_rule_list_element (regular_arc));
}
else
{
IR_set_next_rule_list_element
(IR_last_rule_list_element (regular_arc),
IR_new_rule_list_element (reduced_canonical_rule, NULL));
IR_set_last_rule_list_element
(regular_arc,
IR_next_rule_list_element (IR_last_rule_list_element
(regular_arc)));
}
}
/* The function is called from traverse function. The function clears
visit_flag of given LR-state. */
static int
clear_visit_flag (IR_node_t LR_set)
{
IR_set_visit_flag (LR_set, FALSE);
return TRUE;
}
/* The following variable is set up when a loop is recognized on
traversed paths. */
static int path_loop_has_been_recognized;
/* The function is called from traverse function in order to recognize
loop on traversed path. */
static int
visit_LR_set_for_loop_recognition (IR_node_t LR_set)
{
if (IR_visit_flag (LR_set))
{
path_loop_has_been_recognized = TRUE;
return FALSE;
}
IR_set_visit_flag (LR_set, TRUE);
return TRUE;
}
/* The following variable value is LR set in which we check a reduce
for loop in chain of reduces. */
static IR_node_t start_reduce_loop_recognition_LR_set;
/* The following variable value is LHS of current reduce in checked
chain of reduces. */
static IR_node_t current_lhs_nonterminal_of_reduce_loop_recognition;
/* The following variable contains LR-sets whose visit_flag has been
set up during checking loop in a chain reduces. It may contain
duplicate values for LR-sets containg reduce with empty rhs. */
static vlo_t visited_LR_sets_for_reduce_loop_recognition;
/* The following recursive function is used for recognition of loops
in chain of reduces. */
static int
visit_LR_set_for_reduce_loop_recognition (IR_node_t LR_set)
{
IR_node_t saved_current_lhs_nonterminal_of_reduce_loop_recognition;
IR_node_t current_LR_situation;
IR_node_t canonical_rule;
int canonical_rule_right_hand_side_length;
LR_set
= goto_by_nonterminal (LR_set,
current_lhs_nonterminal_of_reduce_loop_recognition);
path_loop_has_been_recognized
= LR_set == start_reduce_loop_recognition_LR_set;
if (path_loop_has_been_recognized)
return FALSE;
if (IR_visit_flag (LR_set))
return TRUE;
IR_set_visit_flag (LR_set, TRUE);
VLO_ADD_MEMORY (visited_LR_sets_for_reduce_loop_recognition,
&LR_set, sizeof (LR_set));
saved_current_lhs_nonterminal_of_reduce_loop_recognition
= current_lhs_nonterminal_of_reduce_loop_recognition;
for (current_LR_situation = IR_LR_situation_list (LR_set);
current_LR_situation != NULL;
current_LR_situation = IR_next_LR_situation (current_LR_situation))
if (IR_IS_OF_TYPE (IR_element_after_dot (current_LR_situation),
IR_NM_canonical_rule_end)
/* Except for axiom rule. */
&& (IR_canonical_rule (IR_element_after_dot (current_LR_situation))
!= IR_canonical_rule_list (description)))
{
canonical_rule
= IR_canonical_rule (IR_element_after_dot (current_LR_situation));
canonical_rule_right_hand_side_length
= canonical_rule_right_hand_side_prefix_length (canonical_rule,
NULL);
current_lhs_nonterminal_of_reduce_loop_recognition
= IR_left_hand_side (canonical_rule);
if (canonical_rule_right_hand_side_length != 0)
traverse_all_LR_set_predecessors
(LR_set, canonical_rule_right_hand_side_length,
visit_LR_set_for_reduce_loop_recognition);
else
{
IR_set_visit_flag (LR_set, FALSE);
visit_LR_set_for_reduce_loop_recognition (LR_set);
}
if (path_loop_has_been_recognized)
break;
}
current_lhs_nonterminal_of_reduce_loop_recognition
= saved_current_lhs_nonterminal_of_reduce_loop_recognition;
return !path_loop_has_been_recognized;
}
/* The following function returns TRUE if the all states on the given
length paths from the predecessors of given state can be splitted
in order to make unambigous target LR-set from each predecessor of
given LR-state. Criterium of posibility of splitting is the loop
absence on the paths and absence of loop in a chain of reduces
without shifts starting with given LR-set. */
static int
splitting_is_possible (IR_node_t reduce_LR_set, IR_node_t lhs_nonterminal,
int right_hand_side_length)
{
IR_node_t *current_LR_set_ptr;
assert (right_hand_side_length >= 1);
traverse_all_LR_set_predecessor_paths
(reduce_LR_set, right_hand_side_length,
clear_visit_flag, right_hand_side_length);
path_loop_has_been_recognized = FALSE;
traverse_all_LR_set_predecessor_paths
(reduce_LR_set, right_hand_side_length,
visit_LR_set_for_loop_recognition, right_hand_side_length);
if (!path_loop_has_been_recognized)
{
traverse_all_LR_set_predecessor_paths
(reduce_LR_set, right_hand_side_length,
clear_visit_flag, right_hand_side_length);
start_reduce_loop_recognition_LR_set = reduce_LR_set;
current_lhs_nonterminal_of_reduce_loop_recognition = lhs_nonterminal;
VLO_NULLIFY (visited_LR_sets_for_reduce_loop_recognition);
traverse_all_LR_set_predecessors
(reduce_LR_set, right_hand_side_length,
visit_LR_set_for_reduce_loop_recognition);
for (current_LR_set_ptr
= VLO_BEGIN (visited_LR_sets_for_reduce_loop_recognition);
(char *) current_LR_set_ptr
<= (char *) VLO_END (visited_LR_sets_for_reduce_loop_recognition);
current_LR_set_ptr++)
IR_set_visit_flag (*current_LR_set_ptr, FALSE);
}
return !path_loop_has_been_recognized;
}
/* The following function splits given LR-set in order to given LR-set
have only one immediate LR-set predecessor. Of course, it is
possible because check it early by function
`splitting_is_possible'. The function is called by function
`split_states_on_the_path' through function
`reverse_traverse_all_LR_set_predecessor_paths'. */
static void
split_LR_set (IR_node_t LR_set)
{
IR_node_t LR_situation_of_immediate_LR_set_predecessor;
IR_node_t new_LR_set_node;
IR_node_t current_LR_situation;
IR_node_t previous_LR_situation;
IR_double_link_t LR_situation_reference;
vlo_t predecessors;
int predecessors_number;
int current_predecessor_number;
VLO_CREATE (predecessors, 100);
predecessors_number = 0;
/* Collect predecessors (more accurately LR-situations) of given
LR-set. */
for (LR_situation_reference = IR__first_double_link (LR_set);
LR_situation_reference != NULL;
LR_situation_reference
= IR__next_double_link (LR_situation_reference))
{
LR_situation_of_immediate_LR_set_predecessor
= IR__owner (LR_situation_reference);
if (IR_IS_OF_TYPE (LR_situation_of_immediate_LR_set_predecessor,
IR_NM_LR_situation))
{
/* See comments in file `ird.sprut'. */
assert (IR_first_symbol_LR_situation
(LR_situation_of_immediate_LR_set_predecessor));
VLO_ADD_MEMORY (predecessors,
&LR_situation_of_immediate_LR_set_predecessor,
sizeof (IR_node_t));
predecessors_number++;
}
}
/* Split given LR-set so that copies of the LR-set have only one
predecessor. */
#ifndef NDEBUG
if (debug_level >= 2 && predecessors_number > 1)
{
fprintf (stderr,
"splitting LR-set %d times:\n", predecessors_number - 1);
output_LR_set_situations (stderr, LR_set, "\t");
}
#endif
if (predecessors_number > 1 && IR_first_splitted_LR_set (LR_set) == NULL)
{
IR_set_first_splitted_LR_set (LR_set, LR_set);
IR_set_next_splitted_LR_set (LR_set, LR_set);
}
for (current_predecessor_number = 1;
current_predecessor_number < predecessors_number;
current_predecessor_number++)
{
IR_set_splitted_LR_sets_number
(description, IR_splitted_LR_sets_number (description) + 1);
new_LR_set_node = IR_copy_node (LR_set);
IR_set_next_splitted_LR_set (LR_set, new_LR_set_node);
/* Copy LR-situations. */
previous_LR_situation = NULL;
assert (IR_LR_situation_list (LR_set) != NULL);
for (current_LR_situation = IR_LR_situation_list (LR_set);
current_LR_situation != NULL;
current_LR_situation = IR_next_LR_situation (current_LR_situation))
{
if (previous_LR_situation != NULL)
{
IR_set_next_LR_situation
(previous_LR_situation, IR_copy_node (current_LR_situation));
previous_LR_situation
= IR_next_LR_situation (previous_LR_situation);
}
else
{
previous_LR_situation = IR_copy_node (current_LR_situation);
IR_set_LR_situation_list (new_LR_set_node,
previous_LR_situation);
}
IR_set_LR_set (previous_LR_situation, new_LR_set_node);
}
LR_situation_of_immediate_LR_set_predecessor
= (((IR_node_t *) VLO_BEGIN (predecessors))
[current_predecessor_number]);
IR_set_goto_LR_set (LR_situation_of_immediate_LR_set_predecessor,
new_LR_set_node);
IR_set_next_LR_set (new_LR_set_node, IR_next_LR_set (LR_set));
IR_set_next_LR_set (LR_set, new_LR_set_node);
}
VLO_DELETE (predecessors);
return;
}
/* The following function splits LR-sets on given path so that each
LR-set on the path will have only one predecessor. */
static void
split_states_on_the_path (IR_node_t reduce_LR_set, int right_hand_side_length)
{
assert (right_hand_side_length >= 1);
reverse_traverse_all_LR_set_predecessor_paths
(reduce_LR_set, right_hand_side_length - 1,
split_LR_set, right_hand_side_length - 1);
}
/* The following function aims to split LR-sets in order to maximum
number of LR-sets which has reduce LR-situations have only one
LR-set predecessor achieved as the result of reducing by reduce
LR-situations. */
static void
split_LR_sets (void)
{
IR_node_t current_LR_set;
IR_node_t current_LR_core;
IR_node_t current_LR_situation;
IR_node_t reduced_canonical_rule;
int reduce_canonical_rule_right_hand_side_length;
int split_flag;
int iteration_number;
iteration_number = 0;
VLO_CREATE (visited_LR_sets_for_reduce_loop_recognition, 0);
do
{
iteration_number++;
#ifndef NDEBUG
if (debug_level >= 1)
fprintf (stderr, "split iteration %d\n", iteration_number);
#endif
split_flag = FALSE;
for (current_LR_core = IR_LR_core_list (description);
current_LR_core != NULL;
current_LR_core = IR_next_LR_core (current_LR_core))
for (current_LR_set = IR_LR_set_list (current_LR_core);
current_LR_set != NULL;
current_LR_set = IR_next_LR_set (current_LR_set))
if (IR_reachable_flag (current_LR_set))
for (current_LR_situation = IR_LR_situation_list (current_LR_set);
current_LR_situation != NULL;
current_LR_situation
= IR_next_LR_situation (current_LR_situation))
if (IR_IS_OF_TYPE (IR_element_after_dot (current_LR_situation),
IR_NM_canonical_rule_end)
/* Except for axiom rule. */
&& (IR_canonical_rule (IR_element_after_dot
(current_LR_situation))
!= IR_canonical_rule_list (description)))
{
reduced_canonical_rule
= IR_canonical_rule (IR_element_after_dot
(current_LR_situation));
reduce_canonical_rule_right_hand_side_length
= canonical_rule_right_hand_side_prefix_length
(reduced_canonical_rule, NULL);
if (reduce_canonical_rule_right_hand_side_length != 0)
{
/* Count the number of LR-states into which we can
achieve after reducing by given rule. */
LR_set_predecessors_number = 0;
traverse_all_LR_set_predecessors
(current_LR_set,
reduce_canonical_rule_right_hand_side_length,
count_LR_set_predecessors);
if (LR_set_predecessors_number != 1)
{
assert (LR_set_predecessors_number != 0);
if (splitting_is_possible
(current_LR_set,
IR_left_hand_side (reduced_canonical_rule),
reduce_canonical_rule_right_hand_side_length))
{
split_states_on_the_path
(current_LR_set,
reduce_canonical_rule_right_hand_side_length);
split_flag = TRUE;
}
}
}
}
}
while (split_flag);
VLO_DELETE (visited_LR_sets_for_reduce_loop_recognition);
}
/* The following function aims to create regular arcs for maximum
number of reduce LR-situations. The function also mark all
LR-states achieved by the reduce as pushed when it is not
possible. */
static void
make_regular_arcs (void)
{
IR_node_t current_LR_set;
IR_node_t current_LR_core;
IR_node_t current_LR_situation;
IR_node_t reduced_canonical_rule;
IR_node_t regular_arc;
IR_node_t to_LR_set;
int reduced_canonical_rule_right_hand_side_length;
for (current_LR_core = IR_LR_core_list (description);
current_LR_core != NULL;
current_LR_core = IR_next_LR_core (current_LR_core))
for (current_LR_set = IR_LR_set_list (current_LR_core);
current_LR_set != NULL;
current_LR_set = IR_next_LR_set (current_LR_set))
if (IR_reachable_flag (current_LR_set))
for (current_LR_situation = IR_LR_situation_list (current_LR_set);
current_LR_situation != NULL;
current_LR_situation
= IR_next_LR_situation (current_LR_situation))
if (IR_IS_OF_TYPE (IR_element_after_dot (current_LR_situation),
IR_NM_canonical_rule_end)
/* Except for axiom rule. */
&& (IR_canonical_rule (IR_element_after_dot
(current_LR_situation))
!= IR_canonical_rule_list (description)))
{
reduced_canonical_rule
= IR_canonical_rule (IR_element_after_dot
(current_LR_situation));
reduced_canonical_rule_right_hand_side_length
= canonical_rule_right_hand_side_prefix_length
(reduced_canonical_rule, NULL);
LR_set_predecessors_number = 0;
traverse_all_LR_set_predecessors
(current_LR_set,
reduced_canonical_rule_right_hand_side_length,
count_LR_set_predecessors);
if (LR_set_predecessors_number == 1)
{
to_LR_set
= goto_by_nonterminal
(get_the_single_LR_set_predecessor
(current_LR_set,
reduced_canonical_rule_right_hand_side_length),
IR_left_hand_side (reduced_canonical_rule));
#ifndef NDEBUG
if (debug_level >= 2)
{
fprintf (stderr, "make regular arc. from:\n");
output_LR_set_situations (stderr, current_LR_set, "\t");
fprintf (stderr, "to:\n");
output_LR_set_situations (stderr, to_LR_set, "\t");
}
#endif
regular_arc
= IR_new_regular_arc (current_LR_situation, to_LR_set,
NULL);
add_rule_list_element (regular_arc,
reduced_canonical_rule);
IR_set_corresponding_regular_arc (current_LR_situation,
regular_arc);
}
}
}
/* The following function changes arcs to reflect unconditional
transition by sequential regular arcs. */
static void
merge_regular_arcs (void)
{
IR_node_t current_LR_set;
IR_node_t current_LR_core;
IR_node_t current_LR_situation;
IR_node_t LR_situation;
IR_node_t to_LR_set;
IR_node_t fold_LR_situation;
IR_node_t current_regular_arc;
IR_node_t next_regular_arc;
IR_node_t current_rule_list_element;
for (current_LR_core = IR_LR_core_list (description);
current_LR_core != NULL;
current_LR_core = IR_next_LR_core (current_LR_core))
for (current_LR_set = IR_LR_set_list (current_LR_core);
current_LR_set != NULL;
current_LR_set = IR_next_LR_set (current_LR_set))
if (IR_reachable_flag (current_LR_set))
for (current_LR_situation = IR_LR_situation_list (current_LR_set);
current_LR_situation != NULL;
current_LR_situation
= IR_next_LR_situation (current_LR_situation))
{
assert
(IR_corresponding_regular_arc (current_LR_situation) == NULL
|| IR_IS_OF_TYPE (IR_element_after_dot
(current_LR_situation),
IR_NM_canonical_rule_end)
|| (IR_first_symbol_LR_situation (current_LR_situation)
&& IR_goto_arc_has_been_removed (current_LR_situation)));
if (IR_IS_OF_TYPE (IR_element_after_dot (current_LR_situation),
IR_NM_canonical_rule_end)
/* Except for axiom rule. */
&& (IR_canonical_rule (IR_element_after_dot
(current_LR_situation))
!= IR_canonical_rule_list (description)))
for (current_regular_arc
= IR_corresponding_regular_arc (current_LR_situation),
fold_LR_situation = current_LR_situation;
IR_corresponding_regular_arc (fold_LR_situation) != NULL;)
{
to_LR_set = IR_to_LR_set (current_regular_arc);
if (LR_set_has_only_one_action_reduce (to_LR_set,
&LR_situation)
&& IR_corresponding_regular_arc (LR_situation) != NULL)
{
next_regular_arc
= IR_corresponding_regular_arc (LR_situation);
#ifndef NDEBUG
if (debug_level >= 2)
{
fprintf (stderr, "merging regular arc. source: ");
output_LR_situation (stderr, current_LR_situation,
"\t", TRUE);
fprintf (stderr, " its target LR-set:\n");
output_LR_set_situations
(stderr, IR_to_LR_set (current_regular_arc), "\t");
fprintf (stderr, " new targer LR-set:\n");
output_LR_set_situations
(stderr, IR_to_LR_set (next_regular_arc), "\t");
}
#endif
IR_set_to_LR_set (current_regular_arc,
IR_to_LR_set (next_regular_arc));
for (current_rule_list_element
= IR_first_rule_list_element (next_regular_arc);
current_rule_list_element != NULL;
current_rule_list_element
= IR_next_rule_list_element
(current_rule_list_element))
add_rule_list_element
(current_regular_arc,
IR_canonical_rule (current_rule_list_element));
fold_LR_situation = LR_situation;
}
else
break;
}
}
}
/* The following function creates regular arcs which reflect shifting
by terminal and subsequent transition by regular arcs. */
static void
merge_shifts_and_regular_arcs (void)
{
IR_node_t current_LR_set;
IR_node_t current_LR_core;
IR_node_t current_LR_situation;
IR_node_t LR_situation;
IR_node_t goto_LR_set;
IR_node_t regular_arc;
IR_node_t new_regular_arc;
for (current_LR_core = IR_LR_core_list (description);
current_LR_core != NULL;
current_LR_core = IR_next_LR_core (current_LR_core))
for (current_LR_set = IR_LR_set_list (current_LR_core);
current_LR_set != NULL;
current_LR_set = IR_next_LR_set (current_LR_set))
if (IR_reachable_flag (current_LR_set))
for (current_LR_situation = IR_LR_situation_list (current_LR_set);
current_LR_situation != NULL;
current_LR_situation
= IR_next_LR_situation (current_LR_situation))
if (IR_first_symbol_LR_situation (current_LR_situation)
&& !IR_IS_OF_TYPE (IR_element_after_dot (current_LR_situation),
IR_NM_canonical_rule_end)
&& !IR_goto_arc_has_been_removed (current_LR_situation)
&& IR_IS_OF_TYPE (IR_element_itself (IR_element_after_dot
(current_LR_situation)),
IR_NM_single_term_definition)
/* Except for axiom rule. */
&& (IR_canonical_rule (IR_element_after_dot
(current_LR_situation))
!= IR_canonical_rule_list (description))
/* Except for shift on error. */
&& (IR_element_itself (IR_element_after_dot
(current_LR_situation))
!= error_single_definition)
&&
look_ahead_contexts_contain_only_tokens (current_LR_situation))
{
goto_LR_set = IR_goto_LR_set (current_LR_situation);
if (LR_set_has_only_one_action_reduce (goto_LR_set,
&LR_situation)
&& IR_corresponding_regular_arc (LR_situation) != NULL)
{
#ifndef NDEBUG
if (debug_level >= 2)
{
fprintf (stderr, "merging shift: ");
output_LR_situation (stderr, current_LR_situation,
"\t", TRUE);
fprintf (stderr, " with reduce: ");
output_LR_situation (stderr, LR_situation, "\t", TRUE);
}
#endif
regular_arc = IR_corresponding_regular_arc (LR_situation);
IR_set_goto_arc_has_been_removed (current_LR_situation,
TRUE);
new_regular_arc
= IR_new_regular_arc
(current_LR_situation, IR_to_LR_set (regular_arc),
IR_element_itself (IR_element_after_dot
(current_LR_situation)));
IR_set_corresponding_regular_arc (current_LR_situation,
new_regular_arc);
IR_set_first_rule_list_element
(new_regular_arc,
IR_first_rule_list_element (regular_arc));
IR_set_last_rule_list_element
(new_regular_arc, IR_last_rule_list_element (regular_arc));
}
}
}
/* This is the major function which transforms LR-graph (creates
regular arc). */
static void
transform_LR_graph (void)
{
ticker_t temp_ticker;
temp_ticker = create_ticker ();
if (split_lr_sets_flag)
{
traverse_cache_off ();
split_LR_sets ();
traverse_cache_on ();
if (time_flag)
fprintf (stderr,
" splitting LR-sets for regular optimization -- %ssec\n",
active_time_string (temp_ticker));
}
make_regular_arcs ();
merge_regular_arcs ();
merge_shifts_and_regular_arcs ();
}
static int
mark_LR_set_with_used_attribute (IR_node_t LR_set)
{
IR_set_attribute_is_used (LR_set, TRUE);
return TRUE;
}
static int
mark_all_target_as_pushed (IR_node_t LR_set, IR_node_t canonical_rule,
int attribute_flag);
/* The following variable value is LR-set which contains folding
canonical rule being processed in function
`mark_LR_set_corresponding_to_attribute'. */
static IR_node_t current_LR_set_containing_canonical_rule_folding;
/* Remember that correctness of attributes has been already
checked. */
static void
mark_LR_set_corresponding_to_attribute
(IR_node_t canonical_rule, position_t attribute_position,
const char *tag_name, const char *attribute_name)
{
IR_node_t current_right_hand_side_element;
int attribute_number;
IR_node_t original_canonical_rule;
IR_node_t bound_right_hand_side_element;
int predecessors_number;
if (strcmp (attribute_name, "$") == 0)
mark_all_target_as_pushed
(current_LR_set_containing_canonical_rule_folding, canonical_rule, TRUE);
else
{
bound_right_hand_side_element
= IR_original_code_insertion_place (canonical_rule);
if (bound_right_hand_side_element != NULL)
original_canonical_rule
= IR_canonical_rule (bound_right_hand_side_element);
else
original_canonical_rule = canonical_rule;
predecessors_number = 0;
for (current_right_hand_side_element
= IR_right_hand_side (original_canonical_rule);
!IR_IS_OF_TYPE (current_right_hand_side_element,
IR_NM_canonical_rule_end)
&& current_right_hand_side_element != bound_right_hand_side_element;
current_right_hand_side_element
= IR_next_right_hand_side_element
(current_right_hand_side_element))
predecessors_number++;
if (isdigit (*attribute_name) || *attribute_name == '-')
attribute_number = atoi (attribute_name);
else
attribute_number
= attribute_name_to_attribute_number (attribute_name,
original_canonical_rule,
bound_right_hand_side_element);
traverse_all_LR_set_predecessors
(current_LR_set_containing_canonical_rule_folding,
predecessors_number - attribute_number,
mark_LR_set_with_used_attribute);
}
}
static void
dummy_processing_char (char ch)
{
}
/* The usage means any occurence (except as `$$') of attribute in a
action. */
static void
mark_LR_sets_with_used_attribute (void)
{
IR_node_t current_LR_situation;
IR_node_t current_LR_set;
IR_node_t current_LR_core;
for (current_LR_core = IR_LR_core_list (description);
current_LR_core != NULL;
current_LR_core = IR_next_LR_core (current_LR_core))
for (current_LR_set = IR_LR_set_list (current_LR_core);
current_LR_set != NULL;
current_LR_set = IR_next_LR_set (current_LR_set))
if (IR_reachable_flag (current_LR_set))
for (current_LR_situation = IR_LR_situation_list (current_LR_set);
current_LR_situation != NULL;
current_LR_situation
= IR_next_LR_situation (current_LR_situation))
/* For given processing, We can ignore presence regular arc
for the fold LR-situation here. */
if (IR_IS_OF_TYPE (IR_element_after_dot (current_LR_situation),
IR_NM_canonical_rule_end)
/* Except for axiom rule. */
&& (IR_canonical_rule (IR_element_after_dot
(current_LR_situation))
!= IR_canonical_rule_list (description))
&& (IR_look_ahead_context (current_LR_situation) == NULL
|| !it_is_zero_context (IR_look_ahead_context
(current_LR_situation))))
{
current_LR_set_containing_canonical_rule_folding
= current_LR_set;
process_canonical_rule_action
(IR_canonical_rule (IR_element_after_dot
(current_LR_situation)),
dummy_processing_char,
mark_LR_set_corresponding_to_attribute);
}
}
static void mark_used_LR_sets_and_nonterm_goto_arc (IR_node_t LR_set);
/* ??? */
static IR_node_t reduced_single_nonterm_definition;
static int
process_nonterm_goto_arc (IR_node_t LR_set)
{
IR_node_t current_LR_situation;
#ifndef NDEBUG
if (debug_level >= 2)
{
fprintf (stderr, "mark used nonterm `");
output_single_definition (stderr, reduced_single_nonterm_definition);
fprintf (stderr, "' goto arcs in LR-set:\n");
output_LR_set_situations (stderr, LR_set, "\t");
}
#endif
mark_used_LR_sets_and_nonterm_goto_arc (LR_set);
current_LR_situation
= find_goto_LR_situation (LR_set, reduced_single_nonterm_definition);
assert (current_LR_situation != NULL);
IR_set_goto_arc_has_been_removed (current_LR_situation, FALSE);
mark_used_LR_sets_and_nonterm_goto_arc
(IR_goto_LR_set (current_LR_situation));
return TRUE;
}
static void
mark_used_LR_sets_and_nonterm_goto_arc (IR_node_t LR_set)
{
IR_node_t current_LR_situation;
IR_node_t canonical_rule;
IR_node_t saved_reduced_single_nonterm_definition;
if (IR_reachable_flag (LR_set))
return;
#ifndef NDEBUG
if (debug_level >= 2)
{
fprintf (stderr, "mark LR set as reachable\n");
output_LR_set_situations (stderr, LR_set, "\t");
}
#endif
IR_set_reachable_flag (LR_set, TRUE);
/* Process basic LR-arcs. */
for (current_LR_situation = IR_LR_situation_list (LR_set);
current_LR_situation != NULL;
current_LR_situation = IR_next_LR_situation (current_LR_situation))
{
if (IR_corresponding_regular_arc (current_LR_situation) != NULL)
mark_used_LR_sets_and_nonterm_goto_arc
(IR_to_LR_set (IR_corresponding_regular_arc (current_LR_situation)));
if (IR_first_symbol_LR_situation (current_LR_situation)
&& !IR_IS_OF_TYPE (IR_element_after_dot (current_LR_situation),
IR_NM_canonical_rule_end)
&& !IR_goto_arc_has_been_removed (current_LR_situation)
&& IR_IS_OF_TYPE (IR_element_itself (IR_element_after_dot
(current_LR_situation)),
IR_NM_single_term_definition))
mark_used_LR_sets_and_nonterm_goto_arc (IR_goto_LR_set
(current_LR_situation));
}
for (current_LR_situation = IR_LR_situation_list (LR_set);
current_LR_situation != NULL;
current_LR_situation = IR_next_LR_situation (current_LR_situation))
if (IR_IS_OF_TYPE (IR_element_after_dot (current_LR_situation),
IR_NM_canonical_rule_end)
/* Except for axiom rule. */
&& (IR_canonical_rule (IR_element_after_dot (current_LR_situation))
!= IR_canonical_rule_list (description))
&& IR_corresponding_regular_arc (current_LR_situation) == NULL
&& (IR_look_ahead_context (current_LR_situation) == NULL
|| !it_is_zero_context (IR_look_ahead_context
(current_LR_situation))))
{
/* This is reduce. */
canonical_rule
= IR_canonical_rule (IR_element_after_dot (current_LR_situation));
saved_reduced_single_nonterm_definition
= reduced_single_nonterm_definition;
reduced_single_nonterm_definition
= IR_left_hand_side (canonical_rule);
#ifndef NDEBUG
if (debug_level >= 2)
{
fprintf
(stderr,
" process reduce LR-set for marking used nonterm goto arc:\n");
output_LR_set_situations (stderr, LR_set, "\t");
}
#endif
traverse_all_LR_set_predecessors
(LR_set,
canonical_rule_right_hand_side_prefix_length (canonical_rule, NULL),
process_nonterm_goto_arc);
reduced_single_nonterm_definition
= saved_reduced_single_nonterm_definition;
}
}
static void
remove_unused_nonterminal_LR_arcs_and_mark_unreachable_LR_sets (void)
{
IR_node_t current_LR_core;
IR_node_t current_LR_set;
IR_node_t current_LR_situation;
/* Mark all LR-set as ureachable and all nonterminal arcs as removed. */
for (current_LR_core = IR_LR_core_list (description);
current_LR_core != NULL;
current_LR_core = IR_next_LR_core (current_LR_core))
for (current_LR_set = IR_LR_set_list (current_LR_core);
current_LR_set != NULL;
current_LR_set = IR_next_LR_set (current_LR_set))
{