doc: clean up references to `Tracking Locations'.

[bison.git] / src / LR0.c

diff --git a/src/LR0.c b/src/LR0.c
index 3fa5ba5bda947b1bf76a52e0ece86e5d1126f681..b357e2db23bf499d00c874870dd8922ac9e346b6 100644 (file)
--- a/src/LR0.c
+++ b/src/LR0.c
@@ -1,92 +1,123 @@
-/* Generate the nondeterministic finite state machine for bison,
-   Copyright 1984, 1986, 1989, 2000, 2001  Free Software Foundation, Inc.
+/* Generate the LR(0) parser states for Bison.
+
+   Copyright (C) 1984, 1986, 1989, 2000-2002, 2004-2007, 2009-2011 Free
+   Software Foundation, Inc.

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

-   Bison is free software; you can redistribute it and/or modify
+   This program is free software: you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by
    it under the terms of the GNU General Public License as published by

-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.

 
 

-   Bison is distributed in the hope that it will be useful,
+   This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    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.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 
 
 /* See comments in state.h for the data structures that represent it.
    The entry point is generate_states.  */
 
 
 
 /* See comments in state.h for the data structures that represent it.
    The entry point is generate_states.  */
 

+#include <config.h>

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

+
+#include <bitset.h>
+#include <quotearg.h>
+
+#include "LR0.h"
+#include "closure.h"
+#include "complain.h"

 #include "getargs.h"
 #include "getargs.h"

-#include "reader.h"

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

-#include "state.h"
-#include "complain.h"
-#include "closure.h"
-#include "LR0.h"
+#include "gram.h"
+#include "lalr.h"
+#include "reader.h"

 #include "reduce.h"
 #include "reduce.h"

+#include "state.h"
+#include "symtab.h"

 
 

-int nstates;
-int final_state;
-core *first_state = NULL;
-shifts *first_shift = NULL;
-reductions *first_reduction = NULL;
+typedef struct state_list
+{
+  struct state_list *next;
+  state *state;
+} state_list;

 
 

-static core *this_state = NULL;
-static core *last_state = NULL;
-static shifts *last_shift = NULL;
-static reductions *last_reduction = NULL;
+static state_list *first_state = NULL;
+static state_list *last_state = NULL;

 
 

-static int nshifts;
-static short *shift_symbol = NULL;

 
 

-static short *redset = NULL;
-static short *shiftset = NULL;
+/*------------------------------------------------------------------.
+| A state was just discovered from another state.  Queue it for     |
+| later examination, in order to find its transitions.  Return it.  |
+`------------------------------------------------------------------*/
+
+static state *
+state_list_append (symbol_number sym, size_t core_size, item_number *core)
+{
+  state_list *node = xmalloc (sizeof *node);
+  state *s = state_new (sym, core_size, core);
+
+  if (trace_flag & trace_automaton)
+    fprintf (stderr, "state_list_append (state = %d, symbol = %d (%s))\n",
+            nstates, sym, symbols[sym]->tag);
+
+  node->next = NULL;
+  node->state = s;
+
+  if (!first_state)
+    first_state = node;
+  if (last_state)
+    last_state->next = node;
+  last_state = node;
+
+  return s;
+}

 
 

-static short **kernel_base = NULL;
-static int *kernel_size = NULL;
-static short *kernel_items = NULL;
+static int nshifts;
+static symbol_number *shift_symbol;

 
 

-/* hash table for states, to recognize equivalent ones.  */
+static rule **redset;
+static state **shiftset;

 
 

-#define        STATE_TABLE_SIZE        1009
-static core **state_table = NULL;
+static item_number **kernel_base;
+static int *kernel_size;
+static item_number *kernel_items;

 
 \f
 static void
 allocate_itemsets (void)
 {
 
 \f
 static void
 allocate_itemsets (void)
 {

-  int i;
+  symbol_number i;
+  rule_number r;
+  item_number *rhsp;

 
   /* Count the number of occurrences of all the symbols in RITEMS.
      Note that useless productions (hence useless nonterminals) are
      browsed too, hence we need to allocate room for _all_ the
      symbols.  */
 
   /* Count the number of occurrences of all the symbols in RITEMS.
      Note that useless productions (hence useless nonterminals) are
      browsed too, hence we need to allocate room for _all_ the
      symbols.  */

-  int count = 0;
-  short *symbol_count = XCALLOC (short, nsyms + nuseless_nonterminals);
+  size_t count = 0;
+  size_t *symbol_count = xcalloc (nsyms + nuseless_nonterminals,
+                                 sizeof *symbol_count);

 
 

-  for (i = 0; ritem[i]; ++i)
-    if (ritem[i] > 0)
+  for (r = 0; r < nrules; ++r)
+    for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)

       {
        count++;
       {
        count++;

-       symbol_count[ritem[i]]++;
+       symbol_count[*rhsp]++;

       }
 
   /* See comments before new_itemsets.  All the vectors of items
      live inside KERNEL_ITEMS.  The number of active items after
       }
 
   /* See comments before new_itemsets.  All the vectors of items
      live inside KERNEL_ITEMS.  The number of active items after

-     some symbol cannot be more than the number of times that symbol
-     appears as an item, which is symbol_count[symbol].
+     some symbol S cannot be more than the number of times that S
+     appears as an item, which is SYMBOL_COUNT[S].

      We allocate that much space for each symbol.  */
 
      We allocate that much space for each symbol.  */
 

-  kernel_base = XCALLOC (short *, nsyms);
-  if (count)
-    kernel_items = XCALLOC (short, count);
+  kernel_base = xnmalloc (nsyms, sizeof *kernel_base);
+  kernel_items = xnmalloc (count, sizeof *kernel_items);

 
   count = 0;
   for (i = 0; i < nsyms; i++)
 
   count = 0;
   for (i = 0; i < nsyms; i++)


@@ -96,7 +127,7 @@ allocate_itemsets (void)
     }
 
   free (symbol_count);
     }
 
   free (symbol_count);

-  kernel_size = XCALLOC (int, nsyms);
+  kernel_size = xnmalloc (nsyms, sizeof *kernel_size);

 }
 
 
 }
 
 


@@ -105,9 +136,10 @@ allocate_storage (void)
 {
   allocate_itemsets ();
 
 {
   allocate_itemsets ();
 

-  shiftset = XCALLOC (short, nsyms);
-  redset = XCALLOC (short, nrules + 1);
-  state_table = XCALLOC (core *, STATE_TABLE_SIZE);
+  shiftset = xnmalloc (nsyms, sizeof *shiftset);
+  redset = xnmalloc (nrules, sizeof *redset);
+  state_hash_new ();
+  shift_symbol = xnmalloc (nsyms, sizeof *shift_symbol);

 }
 
 
 }
 
 


@@ -119,408 +151,113 @@ free_storage (void)
   free (shiftset);
   free (kernel_base);
   free (kernel_size);
   free (shiftset);
   free (kernel_base);
   free (kernel_size);

-  XFREE (kernel_items);
-  free (state_table);
+  free (kernel_items);
+  state_hash_free ();

 }
 
 
 
 
 }
 
 
 
 

-/*----------------------------------------------------------------.
-| Find which symbols can be shifted in the current state, and for |
-| each one record which items would be active after that shift.   |
-| Uses the contents of itemset.                                   |
-|                                                                 |
-| shift_symbol is set to a vector of the symbols that can be      |
-| shifted.  For each symbol in the grammar, kernel_base[symbol]   |
-| points to a vector of item numbers activated if that symbol is  |
-| shifted, and kernel_size[symbol] is their numbers.              |
-`----------------------------------------------------------------*/
+/*---------------------------------------------------------------.
+| Find which symbols can be shifted in S, and for each one       |
+| record which items would be active after that shift.  Uses the |
+| contents of itemset.                                           |
+|                                                                |
+| shift_symbol is set to a vector of the symbols that can be     |
+| shifted.  For each symbol in the grammar, kernel_base[symbol]  |
+| points to a vector of item numbers activated if that symbol is |
+| shifted, and kernel_size[symbol] is their numbers.             |
+|                                                                |
+| itemset is sorted on item index in ritem, which is sorted on   |
+| rule number.  Compute each kernel_base[symbol] with the same   |
+| sort.                                                          |
+`---------------------------------------------------------------*/

 
 static void
 
 static void

-new_itemsets (void)
+new_itemsets (state *s)

 {
 {

-  int i;
+  size_t i;

 
 

-  if (trace_flag)
-    fprintf (stderr, "Entering new_itemsets, state = %d\n",
-            this_state->number);
+  if (trace_flag & trace_automaton)
+    fprintf (stderr, "Entering new_itemsets, state = %d\n", s->number);

 
 

-  for (i = 0; i < nsyms; i++)
-    kernel_size[i] = 0;
+  memset (kernel_size, 0, nsyms * sizeof *kernel_size);

 
 

-  shift_symbol = XCALLOC (short, nsyms);

   nshifts = 0;
 
   for (i = 0; i < nitemset; ++i)
   nshifts = 0;
 
   for (i = 0; i < nitemset; ++i)

-    {
-      int symbol = ritem[itemset[i]];
-      if (symbol > 0)
-       {
-         if (!kernel_size[symbol])
-           {
-             shift_symbol[nshifts] = symbol;
-             nshifts++;
-           }
-
-         kernel_base[symbol][kernel_size[symbol]] = itemset[i] + 1;
-         kernel_size[symbol]++;
-       }
-    }
+    if (item_number_is_symbol_number (ritem[itemset[i]]))
+      {
+       symbol_number sym = item_number_as_symbol_number (ritem[itemset[i]]);
+       if (!kernel_size[sym])
+         {
+           shift_symbol[nshifts] = sym;
+           nshifts++;
+         }
+
+       kernel_base[sym][kernel_size[sym]] = itemset[i] + 1;
+       kernel_size[sym]++;
+      }

 }
 
 
 
 }
 
 
 

-/*-----------------------------------------------------------------.
-| Subroutine of get_state.  Create a new state for those items, if |
-| necessary.                                                       |
-`-----------------------------------------------------------------*/
-
-static core *
-new_state (int symbol)
-{
-  core *p;
-
-  if (trace_flag)
-    fprintf (stderr, "Entering new_state, state = %d, symbol = %d (%s)\n",
-            this_state->number, symbol, tags[symbol]);
-
-  if (nstates >= MAXSHORT)
-    fatal (_("too many states (max %d)"), MAXSHORT);
-
-  p = CORE_ALLOC (kernel_size[symbol]);
-  p->accessing_symbol = symbol;
-  p->number = nstates;
-  p->nitems = kernel_size[symbol];
-
-  shortcpy (p->items, kernel_base[symbol], kernel_size[symbol]);
-
-  last_state->next = p;
-  last_state = p;
-  nstates++;
-
-  return p;
-}
-
-

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

-| 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.        |
+| Find the state we would get to (from the current state) by    |
+| shifting SYM.  Create a new state if no equivalent one exists |
+| already.  Used by append_states.                              |

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

-static int
-get_state (int symbol)
+static state *
+get_state (symbol_number sym, size_t core_size, item_number *core)

 {
 {

-  int key;
-  int i;
-  core *sp;
+  state *s;

 
 

-  if (trace_flag)
-    fprintf (stderr, "Entering get_state, state = %d, symbol = %d (%s)\n",
-            this_state->number, symbol, tags[symbol]);
-
-  /* Add up the target state's active item numbers to get a hash key.
-     */
-  key = 0;
-  for (i = 0; i < kernel_size[symbol]; ++i)
-    key += kernel_base[symbol][i];
-  key = key % STATE_TABLE_SIZE;
-  sp = state_table[key];
-
-  if (sp)
-    {
-      int found = 0;
-      while (!found)
-       {
-         if (sp->nitems == kernel_size[symbol])
-           {
-             found = 1;
-             for (i = 0; i < kernel_size[symbol]; ++i)
-               if (kernel_base[symbol][i] != sp->items[i])
-                 found = 0;
-           }
+  if (trace_flag & trace_automaton)
+    fprintf (stderr, "Entering get_state, symbol = %d (%s)\n",
+            sym, symbols[sym]->tag);

 
 

-         if (!found)
-           {
-             if (sp->link)
-               {
-                 sp = sp->link;
-               }
-             else              /* bucket exhausted and no match */
-               {
-                 sp = sp->link = new_state (symbol);
-                 found = 1;
-               }
-           }
-       }
-    }
-  else                         /* bucket is empty */
-    {
-      state_table[key] = sp = new_state (symbol);
-    }
+  s = state_hash_lookup (core_size, core);
+  if (!s)
+    s = state_list_append (sym, core_size, core);

 
 

-  if (trace_flag)
-    fprintf (stderr, "Exiting get_state => %d\n", sp->number);
+  if (trace_flag & trace_automaton)
+    fprintf (stderr, "Exiting get_state => %d\n", s->number);

 
 

-  return sp->number;
+  return s;

 }
 
 }
 

-/*------------------------------------------------------------------.
-| Use the information computed by new_itemsets to find the state    |
-| numbers reached by each shift transition from the current state.  |
-|                                                                   |
-| shiftset 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 S.              |
+|                                                                |
+| SHIFTSET is set up as a vector of those states.                |
+`---------------------------------------------------------------*/

 
 static void
 
 static void

-append_states (void)
+append_states (state *s)

 {
   int i;
 {
   int i;

-  int j;
-  int symbol;

 
 

-  if (trace_flag)
-    fprintf (stderr, "Entering append_states, state = %d\n",
-            this_state->number);
+  if (trace_flag & trace_automaton)
+    fprintf (stderr, "Entering append_states, state = %d\n", s->number);

 
 

-  /* first sort shift_symbol into increasing order */
+  /* First sort shift_symbol into increasing order.  */

 
   for (i = 1; i < nshifts; i++)
     {
 
   for (i = 1; i < nshifts; i++)
     {

-      symbol = shift_symbol[i];
-      j = i;
-      while (j > 0 && shift_symbol[j - 1] > symbol)
-       {
-         shift_symbol[j] = shift_symbol[j - 1];
-         j--;
-       }
-      shift_symbol[j] = symbol;
+      symbol_number sym = shift_symbol[i];
+      int j;
+      for (j = i; 0 < j && sym < shift_symbol[j - 1]; j--)
+       shift_symbol[j] = shift_symbol[j - 1];
+      shift_symbol[j] = sym;

     }
 
   for (i = 0; i < nshifts; i++)
     }
 
   for (i = 0; i < nshifts; i++)

-    shiftset[i] = get_state (shift_symbol[i]);
-}
-
-
-static void
-new_states (void)
-{
-  first_state = last_state = this_state = CORE_ALLOC (0);
-  nstates = 1;
-}
-
-
-/*------------------------------------------------------------.
-| Save the NSHIFTS of SHIFTSET into the current linked list.  |
-`------------------------------------------------------------*/
-
-static void
-save_shifts (void)
-{
-  shifts *p = shifts_new (nshifts);
-
-  p->number = this_state->number;
-
-  shortcpy (p->shifts, shiftset, nshifts);
-
-  if (last_shift)
-    last_shift->next = p;
-  else
-    first_shift = p;
-  last_shift = p;
-}
-
-
-/*------------------------------------------------------------------.
-| Subroutine of augment_automaton.  Create the next-to-final state, |
-| to which a shift has already been made in the initial state.      |
-`------------------------------------------------------------------*/
-
-static void
-insert_start_shift (void)
-{
-  core *statep;
-  shifts *sp;
-
-  statep = CORE_ALLOC (0);
-  statep->number = nstates;
-  statep->accessing_symbol = start_symbol;
-
-  last_state->next = statep;
-  last_state = statep;
-
-  /* Make a shift from this state to (what will be) the final state.  */
-  sp = shifts_new (1);
-  sp->number = nstates++;
-  sp->shifts[0] = nstates;
-
-  last_shift->next = sp;
-  last_shift = sp;
-}
-
-
-/*------------------------------------------------------------------.
-| Make sure that the initial state has a shift that accepts the     |
-| grammar's start symbol and goes to the next-to-final state, which |
-| has a shift going to the final state, which has a shift to the    |
-| termination state.  Create such states and shifts if they don't   |
-| happen to exist already.                                          |
-`------------------------------------------------------------------*/
-
-static void
-augment_automaton (void)
-{
-  core *statep;
-  shifts *sp;
-  shifts *sp1 = NULL;
-
-  sp = first_shift;
-
-  if (!sp->nshifts)
-    {
-      /* There are no shifts for any state.  Make one shift, from the
-        initial state to the next-to-final state.  */
-
-      sp = shifts_new (1);
-      sp->shifts[0] = nstates;
-
-      /* Initialize the chain of shifts with sp.  */
-      first_shift = sp;
-      last_shift = sp;
-
-      /* Create the next-to-final state, with shift to
-         what will be the final state.  */
-      insert_start_shift ();
-    }
-  else if (sp->number == 0)
-    {
-      statep = first_state->next;
-
-      /* The states reached by shifts from FIRST_STATE are numbered
-        1..(SP->NSHIFTS).  Look for one reached by START_SYMBOL.  */
-      while (statep->accessing_symbol < start_symbol
-            && statep->number < sp->nshifts)
-       statep = statep->next;
-
-      if (statep->accessing_symbol == start_symbol)
-       {
-         /* We already have a next-to-final state.
-            Make sure it has a shift to what will be the final state.  */
-         while (sp && sp->number < statep->number)
-           {
-             sp1 = sp;
-             sp = sp->next;
-           }
-
-         if (sp && sp->number == statep->number)
-           {
-             int i;
-             shifts *sp2 = shifts_new (sp->nshifts + 1);
-             sp2->number = statep->number;
-             sp2->shifts[0] = nstates;
-             for (i = sp->nshifts; i > 0; i--)
-               sp2->shifts[i] = sp->shifts[i - 1];
-
-             /* Patch sp2 into the chain of shifts in place of sp,
-                following sp1.  */
-             sp2->next = sp->next;
-             sp1->next = sp2;
-             if (sp == last_shift)
-               last_shift = sp2;
-             XFREE (sp);
-           }
-         else
-           {
-             shifts *sp2 = shifts_new (1);
-             sp2->number = statep->number;
-             sp2->shifts[0] = nstates;
-
-             /* Patch sp2 into the chain of shifts between sp1 and sp.  */
-             sp2->next = sp;
-             sp1->next = sp2;
-             if (sp == 0)
-               last_shift = sp2;
-           }
-       }
-      else
-       {
-         int i, k;
-         shifts *sp2;
-
-         /* There is no next-to-final state as yet.  */
-         /* Add one more shift in first_shift,
-            going to the next-to-final state (yet to be made).  */
-         sp = first_shift;
-
-         sp2 = shifts_new (sp->nshifts + 1);
-
-         /* Stick this shift into the vector at the proper place.  */
-         statep = first_state->next;
-         for (k = 0, i = 0; i < sp->nshifts; k++, i++)
-           {
-             if (statep->accessing_symbol > start_symbol && i == k)
-               sp2->shifts[k++] = nstates;
-             sp2->shifts[k] = sp->shifts[i];
-             statep = statep->next;
-           }
-         if (i == k)
-           sp2->shifts[k++] = nstates;
-
-         /* Patch sp2 into the chain of shifts
-            in place of sp, at the beginning.  */
-         sp2->next = sp->next;
-         first_shift = sp2;
-         if (last_shift == sp)
-           last_shift = sp2;
-
-         XFREE (sp);
-
-         /* Create the next-to-final state, with shift to
-            what will be the final state.  */
-         insert_start_shift ();
-       }
-    }
-  else

     {
     {

-      /* The initial state didn't even have any shifts.
-        Give it one shift, to the next-to-final state.  */
-      sp = shifts_new (1);
-      sp->shifts[0] = nstates;
-
-      /* Patch sp into the chain of shifts at the beginning.  */
-      sp->next = first_shift;
-      first_shift = sp;
-
-      /* Create the next-to-final state, with shift to
-        what will be the final state.  */
-      insert_start_shift ();
+      symbol_number sym = shift_symbol[i];
+      shiftset[i] = get_state (sym, kernel_size[sym], kernel_base[sym]);

     }
     }

-
-  /* Make the final state--the one that follows a shift from the
-     next-to-final state.
-     The symbol for that shift is 0 (end-of-file).  */
-  statep = CORE_ALLOC (0);
-  statep->number = nstates;
-  last_state->next = statep;
-  last_state = statep;
-
-  /* Make the shift from the final state to the termination state.  */
-  sp = shifts_new (1);
-  sp->number = nstates++;
-  sp->shifts[0] = nstates;
-  last_shift->next = sp;
-  last_shift = sp;
-
-  /* Note that the variable `final_state' refers to what we sometimes call
-     the termination state.  */
-  final_state = nstates;
-
-  /* Make the termination state.  */
-  statep = CORE_ALLOC (0);
-  statep->number = nstates++;
-  last_state->next = statep;
-  last_state = statep;

 }
 
 
 }
 
 


@@ -531,82 +268,110 @@ augment_automaton (void)
 `----------------------------------------------------------------*/
 
 static void
 `----------------------------------------------------------------*/
 
 static void

-save_reductions (void)
+save_reductions (state *s)

 {
 {

-  int count;
-  int i;
+  int count = 0;
+  size_t i;

 
   /* Find and count the active items that represent ends of rules. */
 
   /* Find and count the active items that represent ends of rules. */

-
-  count = 0;

   for (i = 0; i < nitemset; ++i)
     {
   for (i = 0; i < nitemset; ++i)
     {

-      int item = ritem[itemset[i]];
-      if (item < 0)
-       redset[count++] = -item;
+      item_number item = ritem[itemset[i]];
+      if (item_number_is_rule_number (item))
+       {
+         rule_number r = item_number_as_rule_number (item);
+         redset[count++] = &rules[r];
+         if (r == 0)
+           {
+             /* This is "reduce 0", i.e., accept. */
+             aver (!final_state);
+             final_state = s;
+           }
+       }

     }
 
   /* Make a reductions structure and copy the data into it.  */
     }
 
   /* Make a reductions structure and copy the data into it.  */

+  state_reductions_set (s, count, redset);
+}

 
 

-  if (count)
-    {
-      reductions *p = REDUCTIONS_ALLOC (count);
-
-      p->number = this_state->number;
-      p->nreds = count;
+\f
+/*---------------.
+| Build STATES.  |
+`---------------*/

 
 

-      shortcpy (p->rules, redset, count);
+static void
+set_states (void)
+{
+  states = xcalloc (nstates, sizeof *states);

 
 

-      if (last_reduction)
-       last_reduction->next = p;
-      else
-       first_reduction = p;
-      last_reduction = p;
+  while (first_state)
+    {
+      state_list *this = first_state;
+
+      /* Pessimization, but simplification of the code: make sure all
+        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 *s = this->state;
+      if (!s->transitions)
+       state_transitions_set (s, 0, 0);
+      if (!s->reductions)
+       state_reductions_set (s, 0, 0);
+
+      states[s->number] = s;
+
+      first_state = this->next;
+      free (this);

     }
     }

+  first_state = NULL;
+  last_state = NULL;

 }
 
 }
 

-\f
+

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

-| Compute the nondeterministic finite state machine (see state.h for |
-| details) from the grammar.                                         |
+| Compute the LR(0) parser states (see state.h for details) from the |
+| grammar.                                                           |

 `-------------------------------------------------------------------*/
 
 void
 generate_states (void)
 {
 `-------------------------------------------------------------------*/
 
 void
 generate_states (void)
 {

+  item_number initial_core = 0;
+  state_list *list = NULL;

   allocate_storage ();
   allocate_storage ();

-  new_closure (nitems);
-  new_states ();
+  new_closure (nritems);
+
+  /* Create the initial state.  The 0 at the lhs is the index of the
+     item of this initial rule.  */
+  state_list_append (0, 1, &initial_core);

 
 

-  while (this_state)
+  /* States are queued when they are created; process them all.  */
+  for (list = first_state; list; list = list->next)

     {
     {

-      if (trace_flag)
+      state *s = list->state;
+      if (trace_flag & trace_automaton)

        fprintf (stderr, "Processing state %d (reached by %s)\n",
        fprintf (stderr, "Processing state %d (reached by %s)\n",

-                this_state->number, tags[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
-         accepted next.  */
-      closure (this_state->items, this_state->nitems);
-      /* record the reductions allowed out of this state */
-      save_reductions ();
-      /* find the itemsets of the states that shifts can reach */
-      new_itemsets ();
-      /* find or create the core structures for those states */
-      append_states ();
-
-      /* create the shifts structures for the shifts to those states,
-         now that the state numbers transitioning to are known */
-      save_shifts ();
-
-      /* states are queued when they are created; process them all */
-      this_state = this_state->next;
+                s->number,
+                symbols[s->accessing_symbol]->tag);
+      /* Set up itemset for the transitions out of this state.  itemset gets a
+         vector of all the items that could be accepted next.  */
+      closure (s->items, s->nitems);
+      /* Record the reductions allowed out of this state.  */
+      save_reductions (s);
+      /* Find the itemsets of the states that shifts can reach.  */
+      new_itemsets (s);
+      /* Find or create the core structures for those states.  */
+      append_states (s);
+
+      /* Create the shifts structures for the shifts to those states,
+        now that the state numbers transitioning to are known.  */
+      state_transitions_set (s, nshifts, shiftset);

     }
 
   /* discard various storage */
   free_closure ();
   free_storage ();
 
     }
 
   /* discard various storage */
   free_closure ();
   free_storage ();
 

-  /* set up initial and final states as parser wants them */
-  augment_automaton ();
+  /* Set up STATES. */
+  set_states ();

 }
 }