Use ASCII for Sebastien Fricker's name.

[bison.git] / src / state.c

diff --git a/src/state.c b/src/state.c
index 7c3b69210e463e3166538a97fd01b3ac7c1358bb..280a2f4134654241fc29e18ca5aedf3c0d64310a 100644 (file)
--- a/src/state.c
+++ b/src/state.c
@@ -1,5 +1,7 @@
-/* Type definitions for nondeterministic finite state machine for bison,
-   Copyright 2001 Free Software Foundation, Inc.
+/* Type definitions for nondeterministic finite state machine for Bison.
+
+   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 Free Software
+   Foundation, Inc.

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


@@ -15,21 +17,354 @@
 
    You should have received a copy of the GNU General Public License
    along with Bison; see the file COPYING.  If not, write to
 
    You should have received a copy of the GNU General Public License
    along with Bison; see the file COPYING.  If not, write to

-   the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-   Boston, MA 02111-1307, USA.  */
-
+   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.  */

 
 

+#include <config.h>

 #include "system.h"
 #include "system.h"

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

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

+
+                       /*-------------------.
+                       | Shifts and Gotos.  |
+                       `-------------------*/
+
+
+/*-----------------------------------------.
+| Create a new array of NUM shifts/gotos.  |
+`-----------------------------------------*/
+
+static transitions *
+transitions_new (int num, state **the_states)
+{
+  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++)
+    {
+      aver (j < shifts->num);
+      if (TRANSITION_SYMBOL (shifts, j) == sym)
+       return shifts->states[j];
+    }
+}
+
+
+                       /*--------------------.
+                       | Error transitions.  |
+                       `--------------------*/
+
+

 /*---------------------------------.
 /*---------------------------------.

-| Create a new array of N shitfs.  |
+| Create a new array of NUM errs.  |

 `---------------------------------*/
 
 `---------------------------------*/
 

-shifts *
-shifts_new (int n)
+errs *
+errs_new (int num, symbol **tokens)
+{
+  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;
+}
+
+
+
+
+                       /*-------------.
+                       | Reductions.  |
+                       `-------------*/
+
+
+/*---------------------------------------.
+| Create a new array of NUM reductions.  |
+`---------------------------------------*/
+
+static reductions *
+reductions_new (int num, rule **reds)
+{
+  size_t rules_size = num * sizeof *reds;
+  reductions *res = xmalloc (offsetof (reductions, rules) + rules_size);
+  res->num = num;
+  res->lookahead_tokens = NULL;
+  memcpy (res->rules, reds, rules_size);
+  return res;
+}
+
+
+
+                       /*---------.
+                       | 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)

 {
 {

-  shifts *res = SHIFTS_ALLOC (n);
-  res->nshifts = n;
+  state *res;
+  size_t items_size = nitems * sizeof *core;
+
+  aver (nstates < STATE_NUMBER_MAXIMUM);
+
+  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)
+{
+  aver (!s->transitions);
+  s->transitions = transitions_new (num, trans);
+}
+
+
+/*--------------------------.
+| Set the reductions of S.  |
+`--------------------------*/
+
+void
+state_reductions_set (state *s, int num, rule **reds)
+{
+  aver (!s->reductions);
+  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)
+{
+  aver (!s->errs);
+  s->errs = errs_new (num, tokens);
+}
+
+
+
+/*--------------------------------------------------.
+| Print on OUT all the lookahead tokens such that S |
+| wants to reduce R.                                |
+`--------------------------------------------------*/
+
+void
+state_rule_lookahead_tokens_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->lookahead_tokens && red != -1)
+    {
+      bitset_iterator biter;
+      int k;
+      char const *sep = "";
+      fprintf (out, "  [");
+      BITSET_FOR_EACH (biter, reds->lookahead_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);
+}