1 /* Type definitions for the finite state machine for Bison.
3 Copyright (C) 2001-2007, 2009-2012 Free Software Foundation, Inc.
5 This file is part of Bison, the GNU Compiler Compiler.
7 This program is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
28 #include "print-xml.h"
31 /*-------------------.
33 `-------------------*/
36 /*-----------------------------------------.
37 | Create a new array of NUM shifts/gotos. |
38 `-----------------------------------------*/
41 transitions_new (int num, state **the_states)
43 size_t states_size = num * sizeof *the_states;
44 transitions *res = xmalloc (offsetof (transitions, states) + states_size);
46 memcpy (res->states, the_states, states_size);
51 /*-------------------------------------------------------.
52 | Return the state such that SHIFTS contain a shift/goto |
53 | to it on SYM. Abort if none found. |
54 `-------------------------------------------------------*/
57 transitions_to (transitions *shifts, symbol_number sym)
62 aver (j < shifts->num);
63 if (TRANSITION_SYMBOL (shifts, j) == sym)
64 return shifts->states[j];
69 /*--------------------.
70 | Error transitions. |
71 `--------------------*/
74 /*---------------------------------.
75 | Create a new array of NUM errs. |
76 `---------------------------------*/
79 errs_new (int num, symbol **tokens)
81 size_t symbols_size = num * sizeof *tokens;
82 errs *res = xmalloc (offsetof (errs, symbols) + symbols_size);
84 memcpy (res->symbols, tokens, symbols_size);
96 /*---------------------------------------.
97 | Create a new array of NUM reductions. |
98 `---------------------------------------*/
101 reductions_new (int num, rule **reds)
103 size_t rules_size = num * sizeof *reds;
104 reductions *res = xmalloc (offsetof (reductions, rules) + rules_size);
106 res->lookahead_tokens = NULL;
107 memcpy (res->rules, reds, rules_size);
118 state_number nstates = 0;
119 /* FINAL_STATE is properly set by new_state when it recognizes its
120 accessing symbol: $end. */
121 state *final_state = NULL;
124 /*------------------------------------------------------------------.
125 | Create a new state with ACCESSING_SYMBOL, for those items. Store |
126 | it in the state hash table. |
127 `------------------------------------------------------------------*/
130 state_new (symbol_number accessing_symbol,
131 size_t nitems, item_number *core)
134 size_t items_size = nitems * sizeof *core;
136 aver (nstates < STATE_NUMBER_MAXIMUM);
138 res = xmalloc (offsetof (state, items) + items_size);
139 res->number = nstates++;
140 res->accessing_symbol = accessing_symbol;
141 res->transitions = NULL;
142 res->reductions = NULL;
144 res->state_list = NULL;
146 res->solved_conflicts = NULL;
147 res->solved_conflicts_xml = NULL;
149 res->nitems = nitems;
150 memcpy (res->items, core, items_size);
152 state_hash_insert (res);
158 state_new_isocore (state const *s)
161 size_t items_size = s->nitems * sizeof *s->items;
163 aver (nstates < STATE_NUMBER_MAXIMUM);
165 res = xmalloc (offsetof (state, items) + items_size);
166 res->number = nstates++;
167 res->accessing_symbol = s->accessing_symbol;
169 transitions_new (s->transitions->num, s->transitions->states);
170 res->reductions = reductions_new (s->reductions->num, s->reductions->rules);
172 res->state_list = NULL;
173 res->consistent = s->consistent;
174 res->solved_conflicts = NULL;
175 res->solved_conflicts_xml = NULL;
177 res->nitems = s->nitems;
178 memcpy (res->items, s->items, items_size);
189 state_free (state *s)
191 free (s->transitions);
192 free (s->reductions);
198 /*---------------------------.
199 | Set the transitions of S. |
200 `---------------------------*/
203 state_transitions_set (state *s, int num, state **trans)
205 aver (!s->transitions);
206 s->transitions = transitions_new (num, trans);
210 /*--------------------------.
211 | Set the reductions of S. |
212 `--------------------------*/
215 state_reductions_set (state *s, int num, rule **reds)
217 aver (!s->reductions);
218 s->reductions = reductions_new (num, reds);
223 state_reduction_find (state *s, rule *r)
226 reductions *reds = s->reductions;
227 for (i = 0; i < reds->num; ++i)
228 if (reds->rules[i] == r)
234 /*--------------------.
235 | Set the errs of S. |
236 `--------------------*/
239 state_errs_set (state *s, int num, symbol **tokens)
242 s->errs = errs_new (num, tokens);
247 /*--------------------------------------------------.
248 | Print on OUT all the lookahead tokens such that S |
249 | wants to reduce R. |
250 `--------------------------------------------------*/
253 state_rule_lookahead_tokens_print (state *s, rule *r, FILE *out)
255 /* Find the reduction we are handling. */
256 reductions *reds = s->reductions;
257 int red = state_reduction_find (s, r);
259 /* Print them if there are. */
260 if (reds->lookahead_tokens && red != -1)
262 bitset_iterator biter;
264 char const *sep = "";
266 BITSET_FOR_EACH (biter, reds->lookahead_tokens[red], k, 0)
268 fprintf (out, "%s%s", sep, symbols[k]->tag);
276 state_rule_lookahead_tokens_print_xml (state *s, rule *r,
277 FILE *out, int level)
279 /* Find the reduction we are handling. */
280 reductions *reds = s->reductions;
281 int red = state_reduction_find (s, r);
283 /* Print them if there are. */
284 if (reds->lookahead_tokens && red != -1)
286 bitset_iterator biter;
288 xml_puts (out, level, "<lookaheads>");
289 BITSET_FOR_EACH (biter, reds->lookahead_tokens[red], k, 0)
291 xml_printf (out, level + 1, "<symbol>%s</symbol>",
292 xml_escape (symbols[k]->tag));
294 xml_puts (out, level, "</lookaheads>");
299 /*---------------------.
300 | A state hash table. |
301 `---------------------*/
303 /* Initial capacity of states hash table. */
304 #define HT_INITIAL_CAPACITY 257
306 static struct hash_table *state_table = NULL;
308 /* Two states are equal if they have the same core items. */
310 state_compare (state const *s1, state const *s2)
314 if (s1->nitems != s2->nitems)
317 for (i = 0; i < s1->nitems; ++i)
318 if (s1->items[i] != s2->items[i])
325 state_comparator (void const *s1, void const *s2)
327 return state_compare (s1, s2);
331 state_hash (state const *s, size_t tablesize)
333 /* Add up the state's item numbers to get a hash key. */
336 for (i = 0; i < s->nitems; ++i)
338 return key % tablesize;
342 state_hasher (void const *s, size_t tablesize)
344 return state_hash (s, tablesize);
348 /*-------------------------------.
349 | Create the states hash table. |
350 `-------------------------------*/
353 state_hash_new (void)
355 state_table = hash_initialize (HT_INITIAL_CAPACITY,
363 /*---------------------------------------------.
364 | Free the states hash table, not the states. |
365 `---------------------------------------------*/
368 state_hash_free (void)
370 hash_free (state_table);
374 /*-----------------------------------.
375 | Insert S in the state hash table. |
376 `-----------------------------------*/
379 state_hash_insert (state *s)
381 if (!hash_insert (state_table, s))
386 /*------------------------------------------------------------------.
387 | Find the state associated to the CORE, and return it. If it does |
388 | not exist yet, return NULL. |
389 `------------------------------------------------------------------*/
392 state_hash_lookup (size_t nitems, item_number *core)
394 size_t items_size = nitems * sizeof *core;
395 state *probe = xmalloc (offsetof (state, items) + items_size);
398 probe->nitems = nitems;
399 memcpy (probe->items, core, items_size);
400 entry = hash_lookup (state_table, probe);
406 /*--------------------------------------------------------.
407 | Record S and all states reachable from S in REACHABLE. |
408 `--------------------------------------------------------*/
411 state_record_reachable_states (state *s, bitset reachable)
413 if (bitset_test (reachable, s->number))
415 bitset_set (reachable, s->number);
418 for (i = 0; i < s->transitions->num; ++i)
419 if (!TRANSITION_IS_DISABLED (s->transitions, i))
420 state_record_reachable_states (s->transitions->states[i], reachable);
425 state_remove_unreachable_states (state_number old_to_new[])
427 state_number nstates_reachable = 0;
428 bitset reachable = bitset_create (nstates, BITSET_FIXED);
429 state_record_reachable_states (states[0], reachable);
432 for (i = 0; i < nstates; ++i)
434 if (bitset_test (reachable, states[i]->number))
436 states[nstates_reachable] = states[i];
437 states[nstates_reachable]->number = nstates_reachable;
438 old_to_new[i] = nstates_reachable++;
442 state_free (states[i]);
443 old_to_new[i] = nstates;
447 nstates = nstates_reachable;
448 bitset_free (reachable);
451 /* All the decorated states, indexed by the state number. */
452 state **states = NULL;
455 /*----------------------.
456 | Free all the states. |
457 `----------------------*/
463 for (i = 0; i < nstates; ++i)
464 state_free (states[i]);