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1 /* Output the generated parsing program for bison,
2 Copyright (C) 1984, 1986, 1989, 1992, 2000, 2001, 2002
3 Free Software Foundation, Inc.
4
5 This file is part of Bison, the GNU Compiler Compiler.
6
7 Bison is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
10 any later version.
11
12 Bison is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with Bison; see the file COPYING. If not, write to the Free
19 Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
21
22
23 /* The parser tables consist of these tables.
24
25 YYTRANSLATE = vector mapping yylex's token numbers into bison's
26 token numbers.
27
28 YYTNAME = vector of string-names indexed by bison token number.
29
30 YYTOKNUM = vector of yylex token numbers corresponding to entries
31 in YYTNAME.
32
33 YYRLINE = vector of line-numbers of all rules. For yydebug
34 printouts.
35
36 YYRHS = vector of items of all rules. This is exactly what RITEMS
37 contains. For yydebug and for semantic parser.
38
39 YYPRHS[R] = index in YYRHS of first item for rule R.
40
41 YYR1[R] = symbol number of symbol that rule R derives.
42
43 YYR2[R] = number of symbols composing right hand side of rule R.
44
45 YYSTOS[S] = the symbol number of the symbol that leads to state S.
46
47 YYDEFACT[S] = default rule to reduce with in state s, when YYTABLE
48 doesn't specify something else to do. Zero means the default is an
49 error.
50
51 YYDEFGOTO[I] = default state to go to after a reduction of a rule
52 that generates variable NTOKENS + I, except when YYTABLE specifies
53 something else to do.
54
55 YYPACT[S] = index in YYTABLE of the portion describing state S.
56 The lookahead token's type is used to index that portion to find
57 out what to do.
58
59 If the value in YYTABLE is positive, we shift the token and go to
60 that state.
61
62 If the value is negative, it is minus a rule number to reduce by.
63
64 If the value is zero, the default action from YYDEFACT[S] is used.
65
66 YYPGOTO[I] = the index in YYTABLE of the portion describing what to
67 do after reducing a rule that derives variable I + NTOKENS. This
68 portion is indexed by the parser state number, S, as of before the
69 text for this nonterminal was read. The value from YYTABLE is the
70 state to go to if the corresponding value in YYCHECK is S.
71
72 YYTABLE = a vector filled with portions for different uses, found
73 via YYPACT and YYPGOTO.
74
75 YYCHECK = a vector indexed in parallel with YYTABLE. It indicates,
76 in a roundabout way, the bounds of the portion you are trying to
77 examine.
78
79 Suppose that the portion of YYTABLE starts at index P and the index
80 to be examined within the portion is I. Then if YYCHECK[P+I] != I,
81 I is outside the bounds of what is actually allocated, and the
82 default (from YYDEFACT or YYDEFGOTO) should be used. Otherwise,
83 YYTABLE[P+I] should be used.
84
85 YYFINAL = the state number of the termination state. YYFLAG = most
86 negative short int. Used to flag ?? */
87
88 #include "system.h"
89 #include "bitsetv.h"
90 #include "quotearg.h"
91 #include "getargs.h"
92 #include "files.h"
93 #include "gram.h"
94 #include "complain.h"
95 #include "lalr.h"
96 #include "reader.h"
97 #include "symtab.h"
98 #include "conflicts.h"
99 #include "tables.h"
100
101 /* Several tables will be indexed both by state and nonterminal
102 numbers. We call `vector' such a thing (= either a state or a
103 symbol number.
104
105 Of course vector_number_t ought to be wide enough to contain
106 state_number_t and symbol_number_t. */
107 typedef short vector_number_t;
108 #define VECTOR_NUMBER_MAX ((vector_number_t) SHRT_MAX)
109 #define VECTOR_NUMBER_MIN ((vector_number_t) SHRT_MIN)
110 #define state_number_to_vector_number(State) \
111 ((vector_number_t) State)
112 #define symbol_number_to_vector_number(Symbol) \
113 ((vector_number_t) (state_number_as_int (nstates) + Symbol - ntokens))
114
115 int nvectors;
116
117
118 /* FROMS and TOS are indexed by vector_number_t.
119
120 If VECTOR is a nonterminal, (FROMS[VECTOR], TOS[VECTOR]) form an
121 array of state numbers of the non defaulted GOTO on VECTOR.
122
123 If VECTOR is a state, TOS[VECTOR] is the array of actions to do on
124 the (array of) symbols FROMS[VECTOR].
125
126 In both cases, TALLY[VECTOR] is the size of the arrays
127 FROMS[VECTOR], TOS[VECTOR]; and WIDTH[VECTOR] =
128 (FROMS[VECTOR][SIZE] - FROMS[VECTOR][0] + 1) where SIZE =
129 TALLY[VECTOR].
130
131 FROMS therefore contains symbol_number_t and action_number_t,
132 TOS state_number_t and action_number_t,
133 TALLY sizes,
134 WIDTH differences of FROMS.
135
136 Let base_t be the type of FROMS, TOS, and WIDTH. */
137 #define BASE_MAX ((base_t) INT_MAX)
138 #define BASE_MIN ((base_t) INT_MIN)
139
140 static base_t **froms = NULL;
141 static base_t **tos = NULL;
142 static unsigned int **conflict_tos = NULL;
143 static short *tally = NULL;
144 static base_t *width = NULL;
145
146
147 /* For a given state, N = ACTROW[SYMBOL]:
148
149 If N = 0, stands for `run the default action'.
150 If N = MIN, stands for `raise a parse error'.
151 If N > 0, stands for `shift SYMBOL and go to n'.
152 If N < 0, stands for `reduce -N'. */
153 typedef short action_t;
154 #define ACTION_MAX ((action_t) SHRT_MAX)
155 #define ACTION_MIN ((action_t) SHRT_MIN)
156
157 static action_t *actrow = NULL;
158
159 /* FROMS and TOS are reordered to be compressed. ORDER[VECTOR] is the
160 new vector number of VECTOR. We skip `empty' vectors (i.e.,
161 TALLY[VECTOR] = 0), and call these `entries'. */
162 static vector_number_t *order = NULL;
163 static int nentries;
164
165 base_t *base = NULL;
166 /* A distinguished value of BASE, negative infinite. During the
167 computation equals to BASE_MIN, later mapped to BASE_NINF to
168 keep parser tables small. */
169 base_t base_ninf = 0;
170 static base_t *pos = NULL;
171
172 static unsigned int *conflrow = NULL;
173 unsigned int *conflict_table = NULL;
174 unsigned int *conflict_list = NULL;
175 int conflict_list_cnt;
176 static int conflict_list_free;
177
178 /* TABLE_SIZE is the allocated size of both TABLE and CHECK. We start
179 with more or less the original hard-coded value (which was
180 SHRT_MAX). */
181 static size_t table_size = 32768;
182 base_t *table = NULL;
183 base_t *check = NULL;
184 /* The value used in TABLE to denote explicit parse errors
185 (%nonassoc), a negative infinite. First defaults to ACTION_MIN,
186 but in order to keep small tables, renumbered as TABLE_ERROR, which
187 is the smallest (non error) value minus 1. */
188 base_t table_ninf = 0;
189 static int lowzero;
190 int high;
191
192 state_number_t *yydefgoto;
193 rule_number_t *yydefact;
194
195 /*----------------------------------------------------------------.
196 | If TABLE (and CHECK) appear to be small to be addressed at |
197 | DESIRED, grow them. Note that TABLE[DESIRED] is to be used, so |
198 | the desired size is at least DESIRED + 1. |
199 `----------------------------------------------------------------*/
200
201 static void
202 table_grow (size_t desired)
203 {
204 size_t old_size = table_size;
205
206 while (table_size <= desired)
207 table_size *= 2;
208
209 if (trace_flag & trace_resource)
210 fprintf (stderr, "growing table and check from: %d to %d\n",
211 old_size, table_size);
212
213 table = XREALLOC (table, base_t, table_size);
214 check = XREALLOC (check, base_t, table_size);
215 if (glr_parser)
216 conflict_table = XREALLOC (conflict_table, unsigned int, table_size);
217
218 for (/* Nothing. */; old_size < table_size; ++old_size)
219 {
220 table[old_size] = 0;
221 check[old_size] = -1;
222 }
223 }
224
225
226
227
228 /*-------------------------------------------------------------------.
229 | For GLR parsers, for each conflicted token in STATE, as indicated |
230 | by non-zero entries in CONFLROW, create a list of possible |
231 | reductions that are alternatives to the shift or reduction |
232 | currently recorded for that token in STATE. Store the alternative |
233 | reductions followed by a 0 in CONFLICT_LIST, updating |
234 | CONFLICT_LIST_CNT, and storing an index to the start of the list |
235 | back into CONFLROW. |
236 `-------------------------------------------------------------------*/
237
238 static void
239 conflict_row (state_t *state)
240 {
241 int i, j;
242 reductions_t *reds = state->reductions;
243
244 if (! glr_parser)
245 return;
246
247 for (j = 0; j < ntokens; j += 1)
248 if (conflrow[j])
249 {
250 conflrow[j] = conflict_list_cnt;
251
252 /* Find all reductions for token J, and record all that do not
253 match ACTROW[J]. */
254 for (i = 0; i < reds->num; i += 1)
255 if (bitset_test (reds->lookaheads[i], j)
256 && (actrow[j]
257 != rule_number_as_item_number (reds->rules[i]->number)))
258 {
259 assert (conflict_list_free > 0);
260 conflict_list[conflict_list_cnt] = reds->rules[i]->number + 1;
261 conflict_list_cnt += 1;
262 conflict_list_free -= 1;
263 }
264
265 /* Leave a 0 at the end. */
266 assert (conflict_list_free > 0);
267 conflict_list_cnt += 1;
268 conflict_list_free -= 1;
269 }
270 }
271
272
273 /*------------------------------------------------------------------.
274 | Decide what to do for each type of token if seen as the lookahead |
275 | token in specified state. The value returned is used as the |
276 | default action (yydefact) for the state. In addition, ACTROW is |
277 | filled with what to do for each kind of token, index by symbol |
278 | number, with zero meaning do the default action. The value |
279 | ACTION_MIN, a very negative number, means this situation is an |
280 | error. The parser recognizes this value specially. |
281 | |
282 | This is where conflicts are resolved. The loop over lookahead |
283 | rules considered lower-numbered rules last, and the last rule |
284 | considered that likes a token gets to handle it. |
285 | |
286 | For GLR parsers, also sets CONFLROW[SYM] to an index into |
287 | CONFLICT_LIST iff there is an unresolved conflict (s/r or r/r) |
288 | with symbol SYM. The default reduction is not used for a symbol |
289 | that has any such conflicts. |
290 `------------------------------------------------------------------*/
291
292 static rule_t *
293 action_row (state_t *state)
294 {
295 int i;
296 rule_t *default_rule = NULL;
297 reductions_t *redp = state->reductions;
298 transitions_t *transitions = state->transitions;
299 errs_t *errp = state->errs;
300 /* Set to nonzero to inhibit having any default reduction. */
301 int nodefault = 0;
302 int conflicted = 0;
303
304 for (i = 0; i < ntokens; i++)
305 actrow[i] = conflrow[i] = 0;
306
307 if (redp->lookaheads)
308 {
309 int j;
310 bitset_iterator biter;
311 /* loop over all the rules available here which require
312 lookahead (in reverse order to give precedence to the first
313 rule) */
314 for (i = redp->num - 1; i >= 0; --i)
315 /* and find each token which the rule finds acceptable
316 to come next */
317 BITSET_FOR_EACH (biter, redp->lookaheads[i], j, 0)
318 {
319 /* and record this rule as the rule to use if that
320 token follows. */
321 if (actrow[j] != 0)
322 conflicted = conflrow[j] = 1;
323 actrow[j] = rule_number_as_item_number (redp->rules[i]->number);
324 }
325 }
326
327 /* Now see which tokens are allowed for shifts in this state. For
328 them, record the shift as the thing to do. So shift is preferred
329 to reduce. */
330 FOR_EACH_SHIFT (transitions, i)
331 {
332 symbol_number_t symbol = TRANSITION_SYMBOL (transitions, i);
333 state_t *shift_state = transitions->states[i];
334
335 if (actrow[symbol] != 0)
336 conflicted = conflrow[symbol] = 1;
337 actrow[symbol] = state_number_as_int (shift_state->number);
338
339 /* Do not use any default reduction if there is a shift for
340 error */
341 if (symbol == errtoken->number)
342 nodefault = 1;
343 }
344
345 /* See which tokens are an explicit error in this state (due to
346 %nonassoc). For them, record ACTION_MIN as the action. */
347 for (i = 0; i < errp->num; i++)
348 {
349 symbol_t *symbol = errp->symbols[i];
350 actrow[symbol->number] = ACTION_MIN;
351 }
352
353 /* Now find the most common reduction and make it the default action
354 for this state. */
355
356 if (redp->num >= 1 && !nodefault)
357 {
358 if (state->consistent)
359 default_rule = redp->rules[0];
360 else
361 {
362 int max = 0;
363 for (i = 0; i < redp->num; i++)
364 {
365 int count = 0;
366 rule_t *rule = redp->rules[i];
367 symbol_number_t j;
368
369 for (j = 0; j < ntokens; j++)
370 if (actrow[j] == rule_number_as_item_number (rule->number))
371 count++;
372
373 if (count > max)
374 {
375 max = count;
376 default_rule = rule;
377 }
378 }
379
380 /* GLR parsers need space for conflict lists, so we can't
381 default conflicted entries. For non-conflicted entries
382 or as long as we are not building a GLR parser,
383 actions that match the default are replaced with zero,
384 which means "use the default". */
385
386 if (max > 0)
387 {
388 int j;
389 for (j = 0; j < ntokens; j++)
390 if (actrow[j] == rule_number_as_item_number (default_rule->number)
391 && ! (glr_parser && conflrow[j]))
392 actrow[j] = 0;
393 }
394 }
395 }
396
397 /* If have no default rule, the default is an error.
398 So replace any action which says "error" with "use default". */
399
400 if (!default_rule)
401 for (i = 0; i < ntokens; i++)
402 if (actrow[i] == ACTION_MIN)
403 actrow[i] = 0;
404
405 if (conflicted)
406 conflict_row (state);
407
408 return default_rule;
409 }
410
411
412 /*--------------------------------------------.
413 | Set FROMS, TOS, TALLY and WIDTH for STATE. |
414 `--------------------------------------------*/
415
416 static void
417 save_row (state_number_t state)
418 {
419 symbol_number_t i;
420 int count;
421 base_t *sp = NULL;
422 base_t *sp1 = NULL;
423 base_t *sp2 = NULL;
424 unsigned int *sp3 = NULL;
425
426 /* Number of non default actions in STATE. */
427 count = 0;
428 for (i = 0; i < ntokens; i++)
429 if (actrow[i] != 0)
430 count++;
431
432 if (count == 0)
433 return;
434
435 /* Allocate non defaulted actions. */
436 froms[state] = sp1 = sp = XCALLOC (base_t, count);
437 tos[state] = sp2 = XCALLOC (base_t, count);
438 if (glr_parser)
439 conflict_tos[state] = sp3 = XCALLOC (unsigned int, count);
440 else
441 conflict_tos[state] = NULL;
442
443 /* Store non defaulted actions. */
444 for (i = 0; i < ntokens; i++)
445 if (actrow[i] != 0)
446 {
447 *sp1++ = i;
448 *sp2++ = actrow[i];
449 if (glr_parser)
450 *sp3++ = conflrow[i];
451 }
452
453 tally[state] = count;
454 width[state] = sp1[-1] - sp[0] + 1;
455 }
456
457
458 /*------------------------------------------------------------------.
459 | Figure out the actions for the specified state, indexed by |
460 | lookahead token type. |
461 | |
462 | The YYDEFACT table is output now. The detailed info is saved for |
463 | putting into YYTABLE later. |
464 `------------------------------------------------------------------*/
465
466 static void
467 token_actions (void)
468 {
469 state_number_t i;
470 symbol_number_t j;
471 rule_number_t r;
472
473 int nconflict = conflicts_total_count ();
474
475 yydefact = XCALLOC (rule_number_t, nstates);
476
477 actrow = XCALLOC (action_t, ntokens);
478 conflrow = XCALLOC (unsigned int, ntokens);
479
480 /* Find the rules which are reduced. */
481 if (!glr_parser)
482 for (r = 0; r < nrules; ++r)
483 rules[r].useful = FALSE;
484
485 if (glr_parser)
486 {
487 conflict_list = XCALLOC (unsigned int, 1 + 2 * nconflict);
488 conflict_list_free = 2 * nconflict;
489 conflict_list_cnt = 1;
490 }
491 else
492 conflict_list_free = conflict_list_cnt = 0;
493
494 for (i = 0; i < nstates; ++i)
495 {
496 rule_t *default_rule = action_row (states[i]);
497 yydefact[i] = default_rule ? default_rule->number + 1 : 0;
498 save_row (i);
499
500 /* Now that the parser was computed, we can find which rules are
501 really reduced, and which are not because of SR or RR
502 conflicts. */
503 if (!glr_parser)
504 {
505 for (j = 0; j < ntokens; ++j)
506 if (actrow[j] < 0 && actrow[j] != ACTION_MIN)
507 rules[item_number_as_rule_number (actrow[j])].useful = TRUE;
508 if (yydefact[i])
509 rules[yydefact[i] - 1].useful = TRUE;
510 }
511 }
512
513 free (actrow);
514 free (conflrow);
515 }
516
517
518 /*------------------------------------------------------------------.
519 | Compute FROMS[VECTOR], TOS[VECTOR], TALLY[VECTOR], WIDTH[VECTOR], |
520 | i.e., the information related to non defaulted GOTO on the nterm |
521 | SYMBOL. |
522 | |
523 | DEFAULT_STATE is the principal destination on SYMBOL, i.e., the |
524 | default GOTO destination on SYMBOL. |
525 `------------------------------------------------------------------*/
526
527 static void
528 save_column (symbol_number_t symbol, state_number_t default_state)
529 {
530 int i;
531 base_t *sp;
532 base_t *sp1;
533 base_t *sp2;
534 int count;
535 vector_number_t symno = symbol_number_to_vector_number (symbol);
536
537 goto_number_t begin = goto_map[symbol];
538 goto_number_t end = goto_map[symbol + 1];
539
540 /* Number of non default GOTO. */
541 count = 0;
542 for (i = begin; i < end; i++)
543 if (to_state[i] != default_state)
544 count++;
545
546 if (count == 0)
547 return;
548
549 /* Allocate room for non defaulted gotos. */
550 froms[symno] = sp1 = sp = XCALLOC (base_t, count);
551 tos[symno] = sp2 = XCALLOC (base_t, count);
552
553 /* Store the state numbers of the non defaulted gotos. */
554 for (i = begin; i < end; i++)
555 if (to_state[i] != default_state)
556 {
557 *sp1++ = from_state[i];
558 *sp2++ = to_state[i];
559 }
560
561 tally[symno] = count;
562 width[symno] = sp1[-1] - sp[0] + 1;
563 }
564
565
566 /*----------------------------------------------------------------.
567 | Return `the' most common destination GOTO on SYMBOL (a nterm). |
568 `----------------------------------------------------------------*/
569
570 static state_number_t
571 default_goto (symbol_number_t symbol, short state_count[])
572 {
573 state_number_t s;
574 int i;
575 goto_number_t m = goto_map[symbol];
576 goto_number_t n = goto_map[symbol + 1];
577 state_number_t default_state = (state_number_t) -1;
578 int max = 0;
579
580 if (m == n)
581 return (state_number_t) -1;
582
583 for (s = 0; s < nstates; s++)
584 state_count[s] = 0;
585
586 for (i = m; i < n; i++)
587 state_count[to_state[i]]++;
588
589 for (s = 0; s < nstates; s++)
590 if (state_count[s] > max)
591 {
592 max = state_count[s];
593 default_state = s;
594 }
595
596 return default_state;
597 }
598
599
600 /*-------------------------------------------------------------------.
601 | Figure out what to do after reducing with each rule, depending on |
602 | the saved state from before the beginning of parsing the data that |
603 | matched this rule. |
604 | |
605 | The YYDEFGOTO table is output now. The detailed info is saved for |
606 | putting into YYTABLE later. |
607 `-------------------------------------------------------------------*/
608
609 static void
610 goto_actions (void)
611 {
612 symbol_number_t i;
613 short *state_count = XCALLOC (short, nstates);
614 yydefgoto = XMALLOC (state_number_t, nvars);
615
616 /* For a given nterm I, STATE_COUNT[S] is the number of times there
617 is a GOTO to S on I. */
618 for (i = ntokens; i < nsyms; ++i)
619 {
620 state_number_t default_state = default_goto (i, state_count);
621 save_column (i, default_state);
622 yydefgoto[i - ntokens] = default_state;
623 }
624 free (state_count);
625 }
626
627
628 /*------------------------------------------------------------------.
629 | Compute ORDER, a reordering of vectors, in order to decide how to |
630 | pack the actions and gotos information into yytable. |
631 `------------------------------------------------------------------*/
632
633 static void
634 sort_actions (void)
635 {
636 int i;
637
638 nentries = 0;
639
640 for (i = 0; i < nvectors; i++)
641 if (tally[i] > 0)
642 {
643 int k;
644 int t = tally[i];
645 int w = width[i];
646 int j = nentries - 1;
647
648 while (j >= 0 && (width[order[j]] < w))
649 j--;
650
651 while (j >= 0 && (width[order[j]] == w) && (tally[order[j]] < t))
652 j--;
653
654 for (k = nentries - 1; k > j; k--)
655 order[k + 1] = order[k];
656
657 order[j + 1] = i;
658 nentries++;
659 }
660 }
661
662
663 /* If VECTOR is a state which actions (reflected by FROMS, TOS, TALLY
664 and WIDTH of VECTOR) are common to a previous state, return this
665 state number.
666
667 In any other case, return -1. */
668
669 static state_number_t
670 matching_state (vector_number_t vector)
671 {
672 vector_number_t i = order[vector];
673 int t;
674 int w;
675 int prev;
676
677 /* If VECTOR is a nterm, return -1. */
678 if (i >= (int) nstates)
679 return -1;
680
681 t = tally[i];
682 w = width[i];
683
684 for (prev = vector - 1; prev >= 0; prev--)
685 {
686 vector_number_t j = order[prev];
687 int k;
688 int match = 1;
689
690 /* Given how ORDER was computed, if the WIDTH or TALLY is
691 different, there cannot be a matching state. */
692 if (width[j] != w || tally[j] != t)
693 return -1;
694
695 for (k = 0; match && k < t; k++)
696 if (tos[j][k] != tos[i][k] || froms[j][k] != froms[i][k])
697 match = 0;
698
699 if (match)
700 return j;
701 }
702
703 return -1;
704 }
705
706
707 static base_t
708 pack_vector (vector_number_t vector)
709 {
710 vector_number_t i = order[vector];
711 int j;
712 int t = tally[i];
713 int loc = 0;
714 base_t *from = froms[i];
715 base_t *to = tos[i];
716 unsigned int *conflict_to = conflict_tos[i];
717
718 assert (t);
719
720 for (j = lowzero - from[0]; j < (int) table_size; j++)
721 {
722 int k;
723 int ok = 1;
724
725 for (k = 0; ok && k < t; k++)
726 {
727 loc = j + state_number_as_int (from[k]);
728 if (loc >= (int) table_size)
729 table_grow (loc);
730
731 if (table[loc] != 0)
732 ok = 0;
733 }
734
735 for (k = 0; ok && k < vector; k++)
736 if (pos[k] == j)
737 ok = 0;
738
739 if (ok)
740 {
741 for (k = 0; k < t; k++)
742 {
743 loc = j + from[k];
744 table[loc] = to[k];
745 if (glr_parser && conflict_to != NULL)
746 conflict_table[loc] = conflict_to[k];
747 check[loc] = from[k];
748 }
749
750 while (table[lowzero] != 0)
751 lowzero++;
752
753 if (loc > high)
754 high = loc;
755
756 if (j < BASE_MIN || BASE_MAX < j)
757 fatal ("base_t too small to hold %d\n", j);
758 return j;
759 }
760 }
761 #define pack_vector_succeeded 0
762 assert (pack_vector_succeeded);
763 return 0;
764 }
765
766
767 /*-------------------------------------------------------------.
768 | Remap the negative infinite in TAB from NINF to the greatest |
769 | possible smallest value. Return it. |
770 | |
771 | In most case this allows us to use shorts instead of ints in |
772 | parsers. |
773 `-------------------------------------------------------------*/
774
775 static base_t
776 table_ninf_remap (base_t tab[], size_t size, base_t ninf)
777 {
778 base_t res = 0;
779 size_t i;
780
781 for (i = 0; i < size; i++)
782 if (tab[i] < res && tab[i] != ninf)
783 res = base[i];
784
785 --res;
786
787 for (i = 0; i < size; i++)
788 if (tab[i] == ninf)
789 tab[i] = res;
790
791 return res;
792 }
793
794 static void
795 pack_table (void)
796 {
797 int i;
798
799 base = XCALLOC (base_t, nvectors);
800 pos = XCALLOC (base_t, nentries);
801 table = XCALLOC (base_t, table_size);
802 if (glr_parser)
803 conflict_table = XCALLOC (unsigned int, table_size);
804 check = XCALLOC (base_t, table_size);
805
806 lowzero = 0;
807 high = 0;
808
809 for (i = 0; i < nvectors; i++)
810 base[i] = BASE_MIN;
811
812 for (i = 0; i < (int) table_size; i++)
813 check[i] = -1;
814
815 for (i = 0; i < nentries; i++)
816 {
817 state_number_t state = matching_state (i);
818 base_t place;
819
820 if (state < 0)
821 /* A new set of state actions, or a nonterminal. */
822 place = pack_vector (i);
823 else
824 /* Action of I were already coded for STATE. */
825 place = base[state];
826
827 pos[i] = place;
828 base[order[i]] = place;
829 }
830
831 /* Use the greatest possible negative infinites. */
832 base_ninf = table_ninf_remap (base, nvectors, BASE_MIN);
833 table_ninf = table_ninf_remap (table, high + 1, ACTION_MIN);
834
835 free (pos);
836 }
837
838 \f
839
840 /*-----------------------------------------------------------------.
841 | Compute and output yydefact, yydefgoto, yypact, yypgoto, yytable |
842 | and yycheck. |
843 `-----------------------------------------------------------------*/
844
845 void
846 tables_generate (void)
847 {
848 int i;
849
850 /* That's a poor way to make sure the sizes are properly corelated,
851 in particular the signedness is not taking into account, but it's
852 not useless. */
853 assert (sizeof (nvectors) >= sizeof (nstates));
854 assert (sizeof (nvectors) >= sizeof (nvars));
855
856 nvectors = state_number_as_int (nstates) + nvars;
857
858 froms = XCALLOC (base_t *, nvectors);
859 tos = XCALLOC (base_t *, nvectors);
860 conflict_tos = XCALLOC (unsigned int *, nvectors);
861 tally = XCALLOC (short, nvectors);
862 width = XCALLOC (base_t, nvectors);
863
864 token_actions ();
865
866 goto_actions ();
867 XFREE (goto_map + ntokens);
868 XFREE (from_state);
869 XFREE (to_state);
870
871 order = XCALLOC (vector_number_t, nvectors);
872 sort_actions ();
873 pack_table ();
874 free (order);
875
876 free (tally);
877 free (width);
878
879 for (i = 0; i < nvectors; i++)
880 {
881 XFREE (froms[i]);
882 XFREE (tos[i]);
883 XFREE (conflict_tos[i]);
884 }
885
886 free (froms);
887 free (tos);
888 free (conflict_tos);
889 }
890
891
892 /*-------------------------.
893 | Free the parser tables. |
894 `-------------------------*/
895
896 void
897 tables_free (void)
898 {
899 free (base);
900 free (conflict_table);
901 free (conflict_list);
902 free (table);
903 free (check);
904 free (yydefgoto);
905 free (yydefact);
906 }