/* Generate the nondeterministic finite state machine for bison,
- Copyright 1984, 1986, 1989, 2000, 2001, 2002 Free Software Foundation, Inc.
+
+ Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002 Free Software
+ Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
static state_list_t *first_state = NULL;
static state_list_t *last_state = NULL;
-static void
-state_list_append (state_t *state)
+
+/*------------------------------------------------------------------.
+| A state was just discovered from another state. Queue it for |
+| later examination, in order to find its transitions. Return it. |
+`------------------------------------------------------------------*/
+
+static state_t *
+state_list_append (symbol_number_t symbol,
+ size_t core_size, item_number_t *core)
{
state_list_t *node = XMALLOC (state_list_t, 1);
+ state_t *state = state_new (symbol, core_size, core);
+
+ if (trace_flag & trace_automaton)
+ fprintf (stderr, "state_list_append (state = %d, symbol = %d (%s))\n",
+ nstates, symbol, symbols[symbol]->tag);
+
+ /* If this is the endtoken, and this is not the initial state, then
+ this is the final state. */
+ if (symbol == 0 && first_state)
+ final_state = state;
+
node->next = NULL;
node->state = state;
if (last_state)
last_state->next = node;
last_state = node;
+
+ return state;
}
static int nshifts;
static symbol_number_t *shift_symbol = NULL;
-static short *redset = NULL;
-static state_number_t *shiftset = NULL;
+static rule_t **redset = NULL;
+static state_t **shiftset = NULL;
static item_number_t **kernel_base = NULL;
static int *kernel_size = NULL;
int count = 0;
short *symbol_count = XCALLOC (short, nsyms + nuseless_nonterminals);
- for (r = 1; r < nrules + 1; ++r)
+ for (r = 0; r < nrules; ++r)
for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)
{
count++;
{
allocate_itemsets ();
- shiftset = XCALLOC (state_number_t, nsyms);
- redset = XCALLOC (short, nrules + 1);
+ shiftset = XCALLOC (state_t *, nsyms);
+ redset = XCALLOC (rule_t *, nrules);
state_hash_new ();
shift_symbol = XCALLOC (symbol_number_t, nsyms);
}
{
int i;
- if (trace_flag)
+ if (trace_flag & trace_automaton)
fprintf (stderr, "Entering new_itemsets, state = %d\n",
state->number);
/*-----------------------------------------------------------------.
-| Subroutine of get_state. Create a new state for those items, if |
-| necessary. |
+| Find the state we would get to (from the current state) by |
+| shifting SYMBOL. Create a new state if no equivalent one exists |
+| already. Used by append_states. |
`-----------------------------------------------------------------*/
static state_t *
-new_state (symbol_number_t symbol, size_t core_size, item_number_t *core)
-{
- state_t *res;
-
- if (trace_flag)
- fprintf (stderr, "Entering new_state, state = %d, symbol = %d (%s)\n",
- nstates, symbol, symbol_tag_get (symbols[symbol]));
-
- 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 = res;
-
- state_list_append (res);
- return res;
-}
-
-
-/*--------------------------------------------------------------.
-| Find the state number for the state we would get to (from the |
-| current state) by shifting symbol. Create a new state if no |
-| equivalent one exists already. Used by append_states. |
-`--------------------------------------------------------------*/
-
-static state_number_t
get_state (symbol_number_t symbol, size_t core_size, item_number_t *core)
{
state_t *sp;
- if (trace_flag)
+ if (trace_flag & trace_automaton)
fprintf (stderr, "Entering get_state, symbol = %d (%s)\n",
- symbol, symbol_tag_get (symbols[symbol]));
+ symbol, symbols[symbol]->tag);
sp = state_hash_lookup (core_size, core);
if (!sp)
- sp = new_state (symbol, core_size, core);
+ sp = state_list_append (symbol, core_size, core);
- if (trace_flag)
+ if (trace_flag & trace_automaton)
fprintf (stderr, "Exiting get_state => %d\n", sp->number);
- return sp->number;
+ return sp;
}
-/*------------------------------------------------------------------.
-| Use the information computed by new_itemsets to find the state |
-| numbers reached by each shift transition from STATE. |
-| |
-| TRANSITIONSET is set up as a vector of state numbers of those states. |
-`------------------------------------------------------------------*/
+/*---------------------------------------------------------------.
+| Use the information computed by new_itemsets to find the state |
+| numbers reached by each shift transition from STATE. |
+| |
+| SHIFTSET is set up as a vector of those states. |
+`---------------------------------------------------------------*/
static void
append_states (state_t *state)
int j;
symbol_number_t symbol;
- if (trace_flag)
+ if (trace_flag & trace_automaton)
fprintf (stderr, "Entering append_states, state = %d\n",
state->number);
}
-static void
-new_states (void)
-{
- /* The 0 at the lhs is the index of the item of this initial rule. */
- kernel_base[0][0] = 0;
- kernel_size[0] = 1;
- state_list_append (new_state (0, kernel_size[0], kernel_base[0]));
-}
-
-
-
/*----------------------------------------------------------------.
| Find which rules can be used for reduction transitions from the |
| current state and make a reductions structure for the state to |
int count = 0;
int i;
- /* If this is the final state, we want it to have no reductions at
- all, although it has one for `START_SYMBOL EOF .'. */
- if (final_state && state->number == final_state->number)
- return;
-
/* Find and count the active items that represent ends of rules. */
for (i = 0; i < nritemset; ++i)
{
int item = ritem[itemset[i]];
if (item < 0)
- redset[count++] = -item;
+ redset[count++] = &rules[item_number_as_rule_number (item)];
}
/* Make a reductions structure and copy the data into it. */
state_list_t *this = first_state;
/* Pessimization, but simplification of the code: make sure all
- the states have a shifts, errs, and reductions, even if
- reduced to 0. */
+ the states have valid transitions and reductions members,
+ even if reduced to 0. It is too soon for errs, which are
+ computed later, but set_conflicts. */
state_t *state = this->state;
- if (!state->shifts)
+ if (!state->transitions)
state_transitions_set (state, 0, 0);
- if (!state->errs)
- state->errs = errs_new (0);
if (!state->reductions)
state_reductions_set (state, 0, 0);
state_list_t *list = NULL;
allocate_storage ();
new_closure (nritems);
- new_states ();
+
+ /* Create the initial state. The 0 at the lhs is the index of the
+ item of this initial rule. */
+ kernel_base[0][0] = 0;
+ kernel_size[0] = 1;
+ state_list_append (0, kernel_size[0], kernel_base[0]);
+
list = first_state;
while (list)
{
state_t *state = list->state;
- if (trace_flag)
+ if (trace_flag & trace_automaton)
fprintf (stderr, "Processing state %d (reached by %s)\n",
state->number,
- symbol_tag_get (symbols[state->accessing_symbol]));
+ symbols[state->accessing_symbol]->tag);
/* 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
projects / bison.git / blobdiff