/* 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 *
-shifts_new (int n)
+ /*-------------------.
+ | Shifts and Gotos. |
+ `-------------------*/
+
+
+/*---------------------------------------.
+| Create a new array of N shifts/gotos. |
+`---------------------------------------*/
+
+#define TRANSITIONS_ALLOC(Num) \
+ (transitions_t *) xcalloc ((sizeof (transitions_t) \
+ + (Num - 1) * sizeof (state_t *)), 1)
+
+static transitions_t *
+transitions_new (int num, state_t **the_states)
+{
+ transitions_t *res = TRANSITIONS_ALLOC (num);
+ res->num = num;
+ memcpy (res->states, the_states, num * sizeof (the_states[0]));
+ return res;
+}
+
+
+/*-------------------------------------------------------------------.
+| Return the state such these TRANSITIONS contain a shift/goto to it |
+| on SYMBOL. Aborts if none found. |
+`-------------------------------------------------------------------*/
+
+state_t *
+transitions_to (transitions_t *shifts, symbol_number_t s)
+{
+ int j;
+ for (j = 0; j < shifts->num; j++)
+ if (TRANSITION_SYMBOL (shifts, j) == s)
+ return shifts->states[j];
+ abort ();
+}
+
+
+ /*--------------------.
+ | Error transitions. |
+ `--------------------*/
+
+
+/*-------------------------------.
+| Create a new array of N errs. |
+`-------------------------------*/
+
+#define ERRS_ALLOC(Nerrs) \
+ (errs_t *) xcalloc ((sizeof (errs_t) \
+ + (Nerrs - 1) * sizeof (symbol_t *)), 1)
+
+
+errs_t *
+errs_new (int num, symbol_t **tokens)
+{
+ errs_t *res = ERRS_ALLOC (num);
+ res->num = num;
+ memcpy (res->symbols, tokens, num * sizeof (tokens[0]));
+ return res;
+}
+
+
+
+
+ /*-------------.
+ | Reductions. |
+ `-------------*/
+
+
+/*-------------------------------------.
+| Create a new array of N reductions. |
+`-------------------------------------*/
+
+#define REDUCTIONS_ALLOC(Nreductions) \
+ (reductions_t *) xcalloc ((sizeof (reductions_t) \
+ + (Nreductions - 1) * sizeof (rule_t *)), 1)
+
+static reductions_t *
+reductions_new (int num, rule_t **reductions)
{
- shifts *res = SHIFTS_ALLOC (n);
- res->nshifts = n;
+ reductions_t *res = REDUCTIONS_ALLOC (num);
+ res->num = num;
+ memcpy (res->rules, reductions, num * sizeof (reductions[0]));
+ res->lookaheads = NULL;
return res;
}
+
+
+
+ /*---------.
+ | States. |
+ `---------*/
+
+
+state_number_t nstates = 0;
+/* FINAL_STATE is properly set by new_state when it recognizes its
+ accessing symbol: $end. */
+state_t *final_state = NULL;
+
+#define STATE_ALLOC(Nitems) \
+ (state_t *) xcalloc ((sizeof (state_t) \
+ + (Nitems - 1) * sizeof (item_number_t)), 1)
+
+/*------------------------------------------------------------------.
+| Create a new state with ACCESSING_SYMBOL, for those items. Store |
+| it in the state hash table. |
+`------------------------------------------------------------------*/
+
+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]));
+
+ state_hash_insert (res);
+
+ return res;
+}
+
+
+/*-------------.
+| Free STATE. |
+`-------------*/
+
+static void
+state_free (state_t *state)
+{
+ free (state->transitions);
+ free (state->reductions);
+ free (state->errs);
+ free (state);
+}
+
+
+/*-------------------------------.
+| Set the transitions of STATE. |
+`-------------------------------*/
+
+void
+state_transitions_set (state_t *state, int num, state_t **transitions)
+{
+ assert (!state->transitions);
+ state->transitions = transitions_new (num, transitions);
+}
+
+
+/*------------------------------.
+| Set the reductions of STATE. |
+`------------------------------*/
+
+void
+state_reductions_set (state_t *state, int num, rule_t **reductions)
+{
+ assert (!state->reductions);
+ state->reductions = reductions_new (num, reductions);
+}
+
+
+int
+state_reduction_find (state_t *state, rule_t *rule)
+{
+ int i;
+ reductions_t *reds = state->reductions;
+ for (i = 0; i < reds->num; ++i)
+ if (reds->rules[i] == rule)
+ return i;
+ return -1;
+}
+
+
+/*------------------------.
+| Set the errs of STATE. |
+`------------------------*/
+
+void
+state_errs_set (state_t *state, int num, symbol_t **tokens)
+{
+ assert (!state->errs);
+ state->errs = errs_new (num, tokens);
+}
+
+
+
+/*--------------------------------------------------------------.
+| 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)
+{
+ /* Find the reduction we are handling. */
+ reductions_t *reds = state->reductions;
+ int red = state_reduction_find (state, rule);
+
+ /* Print them if there are. */
+ if (reds->lookaheads && red != -1)
+ {
+ bitset_iterator biter;
+ int k;
+ int not_first = 0;
+ fprintf (out, " [");
+ BITSET_FOR_EACH (biter, reds->lookaheads[red], k, 0)
+ fprintf (out, "%s%s",
+ not_first++ ? ", " : "",
+ symbols[k]->tag);
+ 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)
+ state_free (states[i]);
+ free (states);
+}
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