(state_compare): Now inline. Return bool, not int.

[bison.git] / src / state.c

diff --git a/src/state.c b/src/state.c
index dd8c3b6ecc159263e0439db2875c6a0c4caff039..3afe46cfd004efe850c71d75fb8f672d9949bda6 100644 (file)
--- 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 Free Software Foundation, Inc.

 
    This file is part of Bison, the GNU Compiler Compiler.
 
 
    This file is part of Bison, the GNU Compiler Compiler.
 


@@ -20,64 +21,350 @@
 
 
 #include "system.h"
 
 
 #include "system.h"

+
+#include <hash.h>
+
+#include "complain.h"

 #include "gram.h"
 #include "state.h"
 
 #include "gram.h"
 #include "state.h"
 

-/*---------------------------------.
-| Create a new array of N shitfs.  |
-`---------------------------------*/

 
 

-#define SHIFTS_ALLOC(Nshifts)                                          \
-  (shifts *) xcalloc ((unsigned) (sizeof (shifts)                      \
-                                  + (Nshifts - 1) * sizeof (short)), 1)
+                       /*-------------------.
+                       | Shifts and Gotos.  |
+                       `-------------------*/
+
+
+/*-----------------------------------------.
+| 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 res;
 }
 
 

-/*-------------------------------.
-| Create a new array of N errs.  |
-`-------------------------------*/
+/*-------------------------------------------------------------------.
+| Return the state such these TRANSITIONS contain a shift/goto to it |
+| on S.  Abort if none found.                                        |
+`-------------------------------------------------------------------*/
+
+state *
+transitions_to (transitions *shifts, symbol_number s)
+{
+  int j;
+  for (j = 0; j < shifts->num; j++)
+    if (TRANSITION_SYMBOL (shifts, j) == s)
+      return shifts->states[j];
+  abort ();
+}
+
+
+                       /*--------------------.
+                       | Error transitions.  |
+                       `--------------------*/

 
 

-#define ERRS_ALLOC(Nerrs)                                              \
-  (errs *) xcalloc ((unsigned) (sizeof (errs)                          \
-                                  + (Nerrs - 1) * sizeof (short)), 1)

 
 

+/*---------------------------------.
+| Create a new array of NUM errs.  |
+`---------------------------------*/

 
 errs *
 
 errs *

-errs_new (int n)
+errs_new (int num, symbol **tokens)

 {
 {

-  errs *res = ERRS_ALLOC (n);
-  res->nerrs = n;
+  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;
 }
 
 
   return res;
 }
 
 

-errs *
-errs_dup (errs *src)
+
+
+                       /*-------------.
+                       | Reductions.  |
+                       `-------------*/
+
+
+/*---------------------------------------.
+| Create a new array of NUM reductions.  |
+`---------------------------------------*/
+
+static reductions *
+reductions_new (int num, rule **reds)

 {
 {

-  errs *res = errs_new (src->nerrs);
-  memcpy (res->errs, src->errs, src->nerrs * sizeof (src->errs[0]));
+  size_t rules_size = num * sizeof *reds;
+  reductions *res = xmalloc (offsetof (reductions, rules) + rules_size);
+  res->num = num;
+  res->lookaheads = NULL;
+  memcpy (res->rules, reds, rules_size);

   return res;
 }
 
   return res;
 }
 

-/*-------------------------------------.
-| Create a new array of N reductions.  |
-`-------------------------------------*/

 
 

-#define REDUCTIONS_ALLOC(Nreductions)                                  \
-  (reductions *) xcalloc ((unsigned) (sizeof (reductions)              \
-                                  + (Nreductions - 1) * sizeof (short)), 1)

 
 

-reductions *
-reductions_new (int n)
+                       /*---------.
+                       | States.  |
+                       `---------*/
+
+
+state_number nstates = 0;
+/* FINAL_STATE is properly set by new_state when it recognizes its
+   accessing symbol: $end.  */
+state *final_state = NULL;
+
+
+/*------------------------------------------------------------------.
+| Create a new state with ACCESSING_SYMBOL, for those items.  Store |
+| it in the state hash table.                                       |
+`------------------------------------------------------------------*/
+
+state *
+state_new (symbol_number accessing_symbol,
+          size_t nitems, item_number *core)

 {
 {

-  reductions *res = REDUCTIONS_ALLOC (n);
-  res->nreds = n;
+  state *res;
+  size_t items_size = nitems * sizeof *core;
+
+  if (STATE_NUMBER_MAXIMUM <= nstates)
+    abort ();
+
+  res = xmalloc (offsetof (state, items) + items_size);
+  res->number = nstates++;
+  res->accessing_symbol = accessing_symbol;
+  res->transitions = NULL;
+  res->reductions = NULL;
+  res->errs = NULL;
+  res->consistent = 0;
+  res->solved_conflicts = NULL;
+
+  res->nitems = nitems;
+  memcpy (res->items, core, items_size);
+
+  state_hash_insert (res);
+

   return res;
 }
   return res;
 }

+
+
+/*---------.
+| 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 lookaheads such that S wants to |
+| reduce R.                                            |
+`-----------------------------------------------------*/
+
+void
+state_rule_lookaheads_print (state *s, rule *r, FILE *out)
+{
+  /* Find the reduction we are handling.  */
+  reductions *reds = s->reductions;
+  int red = state_reduction_find (s, r);
+
+  /* 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 inline bool
+state_compare (state const *s1, state const *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 bool
+state_comparator (void const *s1, void const *s2)
+{
+  return state_compare (s1, s2);
+}
+
+static inline unsigned int
+state_hash (state const *s, unsigned int tablesize)
+{
+  /* Add up the state's item numbers to get a hash key.  */
+  unsigned int key = 0;
+  int i;
+  for (i = 0; i < s->nitems; ++i)
+    key += s->items[i];
+  return key % tablesize;
+}
+
+static unsigned int
+state_hasher (void const *s, unsigned int 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);
+}