/* Type definitions for nondeterministic finite state machine for bison,
- Copyright 2001 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
#include "system.h"
+#include "hash.h"
+#include "complain.h"
+#include "gram.h"
#include "state.h"
-/*---------------------------------.
-| Create a new array of N shitfs. |
-`---------------------------------*/
+
+ /*-------------------.
+ | Shifts and Gotos. |
+ `-------------------*/
+
+
+/*---------------------------------------.
+| Create a new array of N shifts/gotos. |
+`---------------------------------------*/
#define SHIFTS_ALLOC(Nshifts) \
- (shifts *) xcalloc ((unsigned) (sizeof (shifts) \
- + (Nshifts - 1) * sizeof (short)), 1)
+ (shifts_t *) xcalloc ((unsigned) (sizeof (shifts_t) \
+ + (Nshifts - 1) * sizeof (state_number_t)), 1)
-shifts *
-shifts_new (int n)
+static shifts_t *
+shifts_new (int nshifts, state_number_t *shifts)
{
- shifts *res = SHIFTS_ALLOC (n);
- res->nshifts = n;
+ shifts_t *res = SHIFTS_ALLOC (nshifts);
+ res->nshifts = nshifts;
+ memcpy (res->shifts, shifts, nshifts * sizeof (shifts[0]));
return res;
}
+/*-----------------------------------------------------------------.
+| Return the state such these SHIFTS contain a shift/goto to it on |
+| SYMBOL. Aborts if none found. |
+`-----------------------------------------------------------------*/
+
+state_t *
+shifts_to (shifts_t *shifts, symbol_number_t s)
+{
+ int j;
+ for (j = 0; j < shifts->nshifts; j++)
+ if (SHIFT_SYMBOL (shifts, j) == s)
+ return states[shifts->shifts[j]];
+ abort ();
+}
+
+
+ /*--------------------.
+ | Error transitions. |
+ `--------------------*/
+
+
/*-------------------------------.
| Create a new array of N errs. |
`-------------------------------*/
#define ERRS_ALLOC(Nerrs) \
- (errs *) xcalloc ((unsigned) (sizeof (errs) \
+ (errs_t *) xcalloc ((unsigned) (sizeof (errs_t) \
+ (Nerrs - 1) * sizeof (short)), 1)
-errs *
+errs_t *
errs_new (int n)
{
- errs *res = ERRS_ALLOC (n);
+ errs_t *res = ERRS_ALLOC (n);
res->nerrs = n;
return res;
}
-errs *
-errs_dup (errs *src)
+errs_t *
+errs_dup (errs_t *src)
{
- errs *res = errs_new (src->nerrs);
- memcpy (res->errs, src->errs, src->nerrs);
+ errs_t *res = errs_new (src->nerrs);
+ memcpy (res->errs, src->errs, src->nerrs * sizeof (src->errs[0]));
return res;
}
+
+
+
+ /*-------------.
+ | Reductions. |
+ `-------------*/
+
+
/*-------------------------------------.
| Create a new array of N reductions. |
`-------------------------------------*/
#define REDUCTIONS_ALLOC(Nreductions) \
- (reductions *) xcalloc ((unsigned) (sizeof (reductions) \
+ (reductions_t *) xcalloc ((unsigned) (sizeof (reductions_t) \
+ (Nreductions - 1) * sizeof (short)), 1)
-reductions *
-reductions_new (int n)
+static reductions_t *
+reductions_new (int nreductions, short *reductions)
{
- reductions *res = REDUCTIONS_ALLOC (n);
- res->nreds = n;
+ reductions_t *res = REDUCTIONS_ALLOC (nreductions);
+ res->nreds = nreductions;
+ memcpy (res->rules, reductions, nreductions * sizeof (reductions[0]));
return res;
}
+
+
+
+ /*---------.
+ | States. |
+ `---------*/
+
+
+state_number_t nstates = 0;
+/* FINAL_STATE is properly set by new_state when it recognizes its
+ accessing symbol: EOF. */
+state_t *final_state = NULL;
+
+#define STATE_ALLOC(Nitems) \
+ (state_t *) xcalloc ((unsigned) (sizeof (state_t) \
+ + (Nitems - 1) * sizeof (item_number_t)), 1)
+
+/*------------------------------------------------------------.
+| Create a new state with ACCESSING_SYMBOL, for those items. |
+`------------------------------------------------------------*/
+
+state_t *
+state_new (symbol_number_t accessing_symbol,
+ size_t core_size, item_number_t *core)
+{
+ state_t *res;
+
+ if (nstates >= STATE_NUMBER_MAX)
+ fatal (_("too many states (max %d)"), STATE_NUMBER_MAX);
+
+ res = STATE_ALLOC (core_size);
+ res->accessing_symbol = accessing_symbol;
+ res->number = nstates;
+ ++nstates;
+ res->solved_conflicts = NULL;
+
+ res->nitems = core_size;
+ memcpy (res->items, core, core_size * sizeof (core[0]));
+
+ return res;
+}
+
+
+/*--------------------------.
+| Set the shifts of STATE. |
+`--------------------------*/
+
+void
+state_shifts_set (state_t *state, int nshifts, state_number_t *shifts)
+{
+ state->shifts = shifts_new (nshifts, shifts);
+}
+
+
+/*------------------------------.
+| Set the reductions of STATE. |
+`------------------------------*/
+
+void
+state_reductions_set (state_t *state, int nreductions, short *reductions)
+{
+ state->reductions = reductions_new (nreductions, reductions);
+}
+
+
+
+/*--------------------------------------------------------------.
+| Print on OUT all the lookaheads such that this STATE wants to |
+| reduce this RULE. |
+`--------------------------------------------------------------*/
+
+void
+state_rule_lookaheads_print (state_t *state, rule_t *rule, FILE *out)
+{
+ int j, k;
+ int nlookaheads = 0;
+ /* Count the number of lookaheads corresponding to this rule. */
+ for (j = 0; j < state->nlookaheads; ++j)
+ for (k = 0; k < ntokens; ++k)
+ if (bitset_test (state->lookaheads[j], k)
+ && state->lookaheads_rule[j]->number == rule->number)
+ nlookaheads++;
+
+ /* Print them if there are. */
+ if (nlookaheads)
+ {
+ fprintf (out, " [");
+ for (j = 0; j < state->nlookaheads; ++j)
+ for (k = 0; k < ntokens; ++k)
+ if (bitset_test (state->lookaheads[j], k)
+ && state->lookaheads_rule[j]->number == rule->number)
+ fprintf (out, "%s%s",
+ symbol_tag_get (symbols[k]),
+ --nlookaheads ? ", " : "");
+ fprintf (out, "]");
+ }
+}
+
+
+/*----------------------.
+| A state hash table. |
+`----------------------*/
+
+/* Initial capacity of states hash table. */
+#define HT_INITIAL_CAPACITY 257
+
+static struct hash_table *state_table = NULL;
+
+/* Two states are equal if they have the same core items. */
+static bool
+state_compare (const state_t *s1, const state_t *s2)
+{
+ int i;
+
+ if (s1->nitems != s2->nitems)
+ return FALSE;
+
+ for (i = 0; i < s1->nitems; ++i)
+ if (s1->items[i] != s2->items[i])
+ return FALSE;
+
+ return TRUE;
+}
+
+static unsigned int
+state_hash (const state_t *state, unsigned int tablesize)
+{
+ /* Add up the state's item numbers to get a hash key. */
+ int key = 0;
+ int i;
+ for (i = 0; i < state->nitems; ++i)
+ key += state->items[i];
+ return key % tablesize;
+}
+
+
+/*-------------------------------.
+| Create the states hash table. |
+`-------------------------------*/
+
+void
+state_hash_new (void)
+{
+ state_table = hash_initialize (HT_INITIAL_CAPACITY,
+ NULL,
+ (Hash_hasher) state_hash,
+ (Hash_comparator) state_compare,
+ (Hash_data_freer) NULL);
+}
+
+
+/*---------------------------------------------.
+| Free the states hash table, not the states. |
+`---------------------------------------------*/
+
+void
+state_hash_free (void)
+{
+ hash_free (state_table);
+}
+
+
+/*---------------------------------------.
+| Insert STATE in the state hash table. |
+`---------------------------------------*/
+
+void
+state_hash_insert (state_t *state)
+{
+ hash_insert (state_table, state);
+}
+
+
+/*------------------------------------------------------------------.
+| Find the state associated to the CORE, and return it. If it does |
+| not exist yet, return NULL. |
+`------------------------------------------------------------------*/
+
+state_t *
+state_hash_lookup (size_t core_size, item_number_t *core)
+{
+ state_t *probe = STATE_ALLOC (core_size);
+ state_t *entry;
+
+ probe->nitems = core_size;
+ memcpy (probe->items, core, core_size * sizeof (core[0]));
+ entry = hash_lookup (state_table, probe);
+ free (probe);
+ return entry;
+}
+
+/* All the decorated states, indexed by the state number. */
+state_t **states = NULL;
+
+
+/*----------------------.
+| Free all the states. |
+`----------------------*/
+
+void
+states_free (void)
+{
+ state_number_t i;
+
+ for (i = 0; i < nstates; ++i)
+ {
+ free (states[i]->shifts);
+ XFREE (states[i]->reductions);
+ free (states[i]->errs);
+ free (states[i]);
+ }
+ XFREE (states);
+}
projects / bison.git / blobdiff