X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/a49aecd528ab271f49fa76a482abbd84ce216b46..e5fb6710321bf3b412e34028ba0b934ab123970b:/src/LR0.c diff --git a/src/LR0.c b/src/LR0.c index 269a8b87..72780632 100644 --- a/src/LR0.c +++ b/src/LR0.c @@ -37,15 +37,6 @@ #include "lalr.h" #include "reduce.h" -unsigned int nstates = 0; -/* Initialize the final state to -1, otherwise, it might be set to 0 - by default, and since we don't compute the reductions of the final - state, we end up not computing the reductions of the initial state, - which is of course needed. - - FINAL_STATE is properly set by new_state when it recognizes the - accessing symbol: EOF. */ -int final_state = -1; static state_t *first_state = NULL; static state_t *this_state = NULL; @@ -55,17 +46,12 @@ static int nshifts; static symbol_number_t *shift_symbol = NULL; static short *redset = NULL; -static short *shiftset = NULL; +static state_number_t *shiftset = NULL; static item_number_t **kernel_base = NULL; static int *kernel_size = NULL; static item_number_t *kernel_items = NULL; -/* hash table for states, to recognize equivalent ones. */ - -#define STATE_HASH_SIZE 1009 -static state_t **state_hash = NULL; - static void allocate_itemsets (void) @@ -114,9 +100,9 @@ allocate_storage (void) { allocate_itemsets (); - shiftset = XCALLOC (short, nsyms); + shiftset = XCALLOC (state_number_t, nsyms); redset = XCALLOC (short, nrules + 1); - state_hash = XCALLOC (state_t *, STATE_HASH_SIZE); + state_hash_new (); shift_symbol = XCALLOC (symbol_number_t, nsyms); } @@ -130,7 +116,7 @@ free_storage (void) free (kernel_base); free (kernel_size); XFREE (kernel_items); - free (state_hash); + state_hash_free (); } @@ -187,37 +173,27 @@ new_itemsets (void) static state_t * new_state (symbol_number_t symbol, size_t core_size, item_number_t *core) { - state_t *p; + state_t *res; if (trace_flag) fprintf (stderr, "Entering new_state, state = %d, symbol = %d (%s)\n", - nstates, symbol, quotearg_style (escape_quoting_style, - symbols[symbol]->tag)); - - if (nstates >= SHRT_MAX) - fatal (_("too many states (max %d)"), SHRT_MAX); - - p = STATE_ALLOC (core_size); - p->accessing_symbol = symbol; - p->number = nstates; - p->nitems = core_size; + nstates, symbol, symbol_tag_get (symbols[symbol])); - memcpy (p->items, core, core_size * sizeof (core[0])); + res = state_new (symbol, core_size, core); + state_hash_insert (res); /* If this is the eoftoken, and this is not the initial state, then this is the final state. */ if (symbol == 0 && first_state) - final_state = p->number; + final_state = res; if (!first_state) - first_state = p; + first_state = res; if (last_state) - last_state->next = p; - last_state = p; + last_state->next = res; + last_state = res; - nstates++; - - return p; + return res; } @@ -227,57 +203,19 @@ new_state (symbol_number_t symbol, size_t core_size, item_number_t *core) | equivalent one exists already. Used by append_states. | `--------------------------------------------------------------*/ -static int +static state_number_t get_state (symbol_number_t symbol, size_t core_size, item_number_t *core) { - int key; - size_t i; state_t *sp; if (trace_flag) fprintf (stderr, "Entering get_state, state = %d, symbol = %d (%s)\n", - this_state->number, symbol, quotearg_style (escape_quoting_style, - symbols[symbol]->tag)); - - /* Add up the target state's active item numbers to get a hash key. - */ - key = 0; - for (i = 0; i < core_size; ++i) - key += core[i]; - key = key % STATE_HASH_SIZE; - sp = state_hash[key]; - - if (sp) - { - int found = 0; - while (!found) - { - if (sp->nitems == core_size) - { - found = 1; - for (i = 0; i < core_size; ++i) - if (core[i] != sp->items[i]) - found = 0; - } - - if (!found) - { - if (sp->link) - { - sp = sp->link; - } - else /* bucket exhausted and no match */ - { - sp = sp->link = new_state (symbol, core_size, core); - found = 1; - } - } - } - } - else /* bucket is empty */ - { - state_hash[key] = sp = new_state (symbol, core_size, core); - } + this_state->number, symbol, + symbol_tag_get (symbols[symbol])); + + sp = state_hash_lookup (core_size, core); + if (!sp) + sp = new_state (symbol, core_size, core); if (trace_flag) fprintf (stderr, "Exiting get_state => %d\n", sp->number); @@ -363,7 +301,7 @@ save_reductions (void) /* If this is the final state, we want it to have no reductions at all, although it has one for `START_SYMBOL EOF .'. */ - if (this_state->number == final_state) + if (final_state && this_state->number == final_state->number) return; /* Find and count the active items that represent ends of rules. */ @@ -406,6 +344,7 @@ set_states (void) } } + /*-------------------------------------------------------------------. | Compute the nondeterministic finite state machine (see state.h for | | details) from the grammar. | @@ -423,8 +362,7 @@ generate_states (void) if (trace_flag) fprintf (stderr, "Processing state %d (reached by %s)\n", this_state->number, - quotearg_style (escape_quoting_style, - symbols[this_state->accessing_symbol]->tag)); + symbol_tag_get (symbols[this_state->accessing_symbol])); /* Set up ruleset and itemset for the transitions out of this state. ruleset gets a 1 bit for each rule that could reduce now. itemset gets a vector of all the items that could be