X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/df0e7316a9b91827e01a9de2643a73baaa6382b4..95f22ad2a777be59535616142910f8914dac6f26:/src/state.c diff --git a/src/state.c b/src/state.c index 3000f9dc..6ced8e5a 100644 --- a/src/state.c +++ b/src/state.c @@ -1,5 +1,6 @@ -/* Type definitions for nondeterministic finite state machine for bison, - Copyright (C) 2001, 2002 Free Software Foundation, Inc. +/* Type definitions for nondeterministic finite state machine for Bison. + + Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. @@ -20,6 +21,9 @@ #include "system.h" + +#include + #include "complain.h" #include "gram.h" #include "state.h" @@ -30,23 +34,35 @@ `-------------------*/ -/*---------------------------------. -| Create a new array of N shitfs. | -`---------------------------------*/ - -#define SHIFTS_ALLOC(Nshifts) \ - (shifts *) xcalloc ((unsigned) (sizeof (shifts) \ - + (Nshifts - 1) * sizeof (short)), 1) +/*-----------------------------------------. +| Create a new array of NUM shifts/gotos. | +`-----------------------------------------*/ -shifts * -shifts_new (int n) +static transitions * +transitions_new (int num, state **the_states) { - shifts *res = SHIFTS_ALLOC (n); - res->nshifts = n; + size_t states_size = num * sizeof *the_states; + transitions *res = xmalloc (offsetof (transitions, states) + states_size); + res->num = num; + memcpy (res->states, the_states, states_size); return res; } +/*-------------------------------------------------------. +| Return the state such that SHIFTS contain a shift/goto | +| to it on SYM. Abort if none found. | +`-------------------------------------------------------*/ + +state * +transitions_to (transitions *shifts, symbol_number sym) +{ + int j; + for (j = 0; j < shifts->num; j++) + if (TRANSITION_SYMBOL (shifts, j) == sym) + return shifts->states[j]; + abort (); +} /*--------------------. @@ -54,29 +70,17 @@ shifts_new (int n) `--------------------*/ -/*-------------------------------. -| Create a new array of N errs. | -`-------------------------------*/ - -#define ERRS_ALLOC(Nerrs) \ - (errs *) xcalloc ((unsigned) (sizeof (errs) \ - + (Nerrs - 1) * sizeof (short)), 1) - - -errs * -errs_new (int n) -{ - errs *res = ERRS_ALLOC (n); - res->nerrs = n; - return res; -} - +/*---------------------------------. +| Create a new array of NUM errs. | +`---------------------------------*/ errs * -errs_dup (errs *src) +errs_new (int num, symbol **tokens) { - errs *res = errs_new (src->nerrs); - memcpy (res->errs, src->errs, src->nerrs * sizeof (src->errs[0])); + size_t symbols_size = num * sizeof *tokens; + errs *res = xmalloc (offsetof (errs, symbols) + symbols_size); + res->num = num; + memcpy (res->symbols, tokens, symbols_size); return res; } @@ -88,19 +92,18 @@ errs_dup (errs *src) `-------------*/ -/*-------------------------------------. -| Create a new array of N reductions. | -`-------------------------------------*/ - -#define REDUCTIONS_ALLOC(Nreductions) \ - (reductions *) xcalloc ((unsigned) (sizeof (reductions) \ - + (Nreductions - 1) * sizeof (short)), 1) +/*---------------------------------------. +| Create a new array of NUM reductions. | +`---------------------------------------*/ -reductions * -reductions_new (int n) +static reductions * +reductions_new (int num, rule **reds) { - reductions *res = REDUCTIONS_ALLOC (n); - res->nreds = n; + size_t rules_size = num * sizeof *reds; + reductions *res = xmalloc (offsetof (reductions, rules) + rules_size); + res->num = num; + res->look_ahead_tokens = NULL; + memcpy (res->rules, reds, rules_size); return res; } @@ -111,69 +114,258 @@ reductions_new (int n) `---------*/ -state_number_t nstates = 0; +state_number nstates = 0; /* FINAL_STATE is properly set by new_state when it recognizes its - accessing symbol: EOF. */ -state_t *final_state = NULL; + accessing symbol: $end. */ +state *final_state = NULL; -/*------------------------------------------------------------. -| 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; +/*------------------------------------------------------------------. +| Create a new state with ACCESSING_SYMBOL, for those items. Store | +| it in the state hash table. | +`------------------------------------------------------------------*/ - if (nstates >= STATE_NUMBER_MAX) - fatal (_("too many states (max %d)"), STATE_NUMBER_MAX); +state * +state_new (symbol_number accessing_symbol, + size_t nitems, item_number *core) +{ + state *res; + size_t items_size = nitems * sizeof *core; -#define STATE_ALLOC(Nitems) \ - (state_t *) xcalloc ((unsigned) (sizeof (state_t) \ - + (Nitems - 1) * sizeof (item_number_t)), 1) + if (STATE_NUMBER_MAXIMUM <= nstates) + abort (); - res = STATE_ALLOC (core_size); + res = xmalloc (offsetof (state, items) + items_size); + res->number = nstates++; res->accessing_symbol = accessing_symbol; - res->number = nstates; - ++nstates; + res->transitions = NULL; + res->reductions = NULL; + res->errs = NULL; + res->consistent = 0; res->solved_conflicts = NULL; - res->nitems = core_size; - memcpy (res->items, core, core_size * sizeof (core[0])); + res->nitems = nitems; + memcpy (res->items, core, items_size); + + state_hash_insert (res); return res; } -/*--------------------------------------------------------------. -| Print on OUT all the lookaheads such that this STATE wants to | -| reduce this RULE. | -`--------------------------------------------------------------*/ +/*---------. +| Free S. | +`---------*/ + +static void +state_free (state *s) +{ + free (s->transitions); + free (s->reductions); + free (s->errs); + free (s); +} + + +/*---------------------------. +| Set the transitions of S. | +`---------------------------*/ + +void +state_transitions_set (state *s, int num, state **trans) +{ + if (s->transitions) + abort (); + s->transitions = transitions_new (num, trans); +} + + +/*--------------------------. +| Set the reductions of S. | +`--------------------------*/ + +void +state_reductions_set (state *s, int num, rule **reds) +{ + if (s->reductions) + abort (); + s->reductions = reductions_new (num, reds); +} + + +int +state_reduction_find (state *s, rule *r) +{ + int i; + reductions *reds = s->reductions; + for (i = 0; i < reds->num; ++i) + if (reds->rules[i] == r) + return i; + return -1; +} + + +/*--------------------. +| Set the errs of S. | +`--------------------*/ + +void +state_errs_set (state *s, int num, symbol **tokens) +{ + if (s->errs) + abort (); + s->errs = errs_new (num, tokens); +} + + + +/*---------------------------------------------------. +| Print on OUT all the look-ahead tokens such that S | +| wants to reduce R. | +`---------------------------------------------------*/ void -state_rule_lookaheads_print (state_t *state, rule_t *rule, FILE *out) +state_rule_look_ahead_tokens_print (state *s, rule *r, 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++; + /* Find the reduction we are handling. */ + reductions *reds = s->reductions; + int red = state_reduction_find (s, r); /* Print them if there are. */ - if (nlookaheads) + if (reds->look_ahead_tokens && red != -1) { + bitset_iterator biter; + int k; + char const *sep = ""; 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 ? ", " : ""); + BITSET_FOR_EACH (biter, reds->look_ahead_tokens[red], k, 0) + { + fprintf (out, "%s%s", sep, symbols[k]->tag); + sep = ", "; + } 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 inline bool +state_compare (state const *s1, state const *s2) +{ + size_t 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 bool +state_comparator (void const *s1, void const *s2) +{ + return state_compare (s1, s2); +} + +static inline size_t +state_hash (state const *s, size_t tablesize) +{ + /* Add up the state's item numbers to get a hash key. */ + size_t key = 0; + size_t i; + for (i = 0; i < s->nitems; ++i) + key += s->items[i]; + return key % tablesize; +} + +static size_t +state_hasher (void const *s, size_t tablesize) +{ + return state_hash (s, tablesize); +} + + +/*-------------------------------. +| Create the states hash table. | +`-------------------------------*/ + +void +state_hash_new (void) +{ + state_table = hash_initialize (HT_INITIAL_CAPACITY, + NULL, + state_hasher, + state_comparator, + NULL); +} + + +/*---------------------------------------------. +| Free the states hash table, not the states. | +`---------------------------------------------*/ + +void +state_hash_free (void) +{ + hash_free (state_table); +} + + +/*-----------------------------------. +| Insert S in the state hash table. | +`-----------------------------------*/ + +void +state_hash_insert (state *s) +{ + hash_insert (state_table, s); +} + + +/*------------------------------------------------------------------. +| Find the state associated to the CORE, and return it. If it does | +| not exist yet, return NULL. | +`------------------------------------------------------------------*/ + +state * +state_hash_lookup (size_t nitems, item_number *core) +{ + size_t items_size = nitems * sizeof *core; + state *probe = xmalloc (offsetof (state, items) + items_size); + state *entry; + + probe->nitems = nitems; + memcpy (probe->items, core, items_size); + entry = hash_lookup (state_table, probe); + free (probe); + return entry; +} + +/* All the decorated states, indexed by the state number. */ +state **states = NULL; + + +/*----------------------. +| Free all the states. | +`----------------------*/ + +void +states_free (void) +{ + state_number i; + for (i = 0; i < nstates; ++i) + state_free (states[i]); + free (states); +}