* src/conflicts.c (print_reductions): Improve variable locality.

[bison.git] / src / LR0.c

diff --git a/src/LR0.c b/src/LR0.c
index 340221951c47253746ad26d8a3443fa0749a6b74..94a2ed84e8845f7afaf9e9e323136d6abc922c61 100644 (file)
--- a/src/LR0.c
+++ b/src/LR0.c
@@ -1,114 +1,92 @@
 /* Generate the nondeterministic finite state machine for bison,
 /* Generate the nondeterministic finite state machine for bison,

-   Copyright (C) 1984, 1986, 1989 Free Software Foundation, Inc.
+   Copyright 1984, 1986, 1989, 2000, 2001  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
-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.
+   Bison is free software; you can redistribute it and/or modify
+   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.

 
 

-Bison 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.
+   Bison 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
-along with Bison; see the file COPYING.  If not, write to
-the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+   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.  */

 
 
 /* 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 <stdio.h>

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

-#include "machine.h"
-#include "alloc.h"
+#include "getargs.h"
+#include "reader.h"

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

-
-
-extern char *nullable;
-extern short *itemset;
-extern short *itemsetend;
-
+#include "complain.h"
+#include "closure.h"
+#include "LR0.h"
+#include "reduce.h"

 
 int nstates;
 int final_state;
 
 int nstates;
 int final_state;

-core *first_state;
-shifts *first_shift;
-reductions *first_reduction;
-
-int get_state();
-core *new_state();
-
-void new_itemsets();
-void append_states();
-void initialize_states();
-void save_shifts();
-void save_reductions();
-void augment_automaton();
-void insert_start_shift();
-extern void initialize_closure();
-extern void closure();
-extern void finalize_closure();
-extern void toomany();
-
-static core *this_state;
-static core *last_state;
-static shifts *last_shift;
-static reductions *last_reduction;
+core *first_state = NULL;
+shifts *first_shift = NULL;
+reductions *first_reduction = NULL;
+
+static core *this_state = NULL;
+static core *last_state = NULL;
+static shifts *last_shift = NULL;
+static reductions *last_reduction = NULL;

 
 static int nshifts;
 
 static int nshifts;

-static short *shift_symbol;
+static short *shift_symbol = NULL;

 
 

-static short *redset;
-static short *shiftset;
+static short *redset = NULL;
+static short *shiftset = NULL;

 
 

-static short **kernel_base;
-static short **kernel_end;
-static short *kernel_items;
+static short **kernel_base = NULL;
+static int *kernel_size = NULL;
+static short *kernel_items = NULL;

 
 /* hash table for states, to recognize equivalent ones.  */
 
 #define        STATE_TABLE_SIZE        1009
 
 /* hash table for states, to recognize equivalent ones.  */
 
 #define        STATE_TABLE_SIZE        1009

-static core **state_table;
+static core **state_table = NULL;

 
 

-
-
-void
-allocate_itemsets()
+\f
+static void
+allocate_itemsets (void)

 {
 {

-  register short *itemp;
-  register int symbol;
-  register int i;
-  register int count;
-  register short *symbol_count;
-
-  count = 0;
-  symbol_count = NEW2(nsyms, short);
-
-  itemp = ritem;
-  symbol = *itemp++;
-  while (symbol)
-    {
-      if (symbol > 0)
-       {
-         count++;
-         symbol_count[symbol]++;
-       }
-      symbol = *itemp++;
-    }
-
-  /* see comments before new_itemsets.  All the vectors of items
-     live inside kernel_items.  The number of active items after
+  int i;
+
+  /* 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);
+
+  for (i = 0; ritem[i]; ++i)
+    if (ritem[i] > 0)
+      {
+       count++;
+       symbol_count[ritem[i]]++;
+      }
+
+  /* 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].
      We allocate that much space for each symbol.  */
 
      some symbol cannot be more than the number of times that symbol
      appears as an item, which is symbol_count[symbol].
      We allocate that much space for each symbol.  */
 

-  kernel_base = NEW2(nsyms, short *);
-  kernel_items = NEW2(count, short);
+  kernel_base = XCALLOC (short *, nsyms);
+  if (count)
+    kernel_items = XCALLOC (short, count);

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


@@ -117,120 +95,77 @@ allocate_itemsets()
       count += symbol_count[i];
     }
 
       count += symbol_count[i];
     }
 

-  shift_symbol = symbol_count;
-  kernel_end = NEW2(nsyms, short *);
+  free (symbol_count);
+  kernel_size = XCALLOC (int, nsyms);

 }
 
 
 }
 
 

-void
-allocate_storage()
+static void
+allocate_storage (void)

 {
 {

-  allocate_itemsets();
+  allocate_itemsets ();

 
 

-  shiftset = NEW2(nsyms, short);
-  redset = NEW2(nrules + 1, short);
-  state_table = NEW2(STATE_TABLE_SIZE, core *);
+  shiftset = XCALLOC (short, nsyms);
+  redset = XCALLOC (short, nrules + 1);
+  state_table = XCALLOC (core *, STATE_TABLE_SIZE);

 }
 
 
 }
 
 

-void
-free_storage()
+static void
+free_storage (void)

 {
 {

-  FREE(shift_symbol);
-  FREE(redset);
-  FREE(shiftset);
-  FREE(kernel_base);
-  FREE(kernel_end);
-  FREE(kernel_items);
-  FREE(state_table);
+  free (shift_symbol);
+  free (redset);
+  free (shiftset);
+  free (kernel_base);
+  free (kernel_size);
+  XFREE (kernel_items);
+  free (state_table);

 }
 
 
 
 }
 
 
 

-/* compute the nondeterministic finite state machine (see state.h for details)
-from the grammar.  */
-void
-generate_states()
-{
-  allocate_storage();
-  initialize_closure(nitems);
-  initialize_states();
-
-  while (this_state)
-    {
-      /* 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 */
-      if (nshifts > 0)
-        save_shifts();
-
-      /* states are queued when they are created; process them all */
-      this_state = this_state->next;
-    }
-
-  /* discard various storage */
-  finalize_closure();
-  free_storage();
-
-  /* set up initial and final states as parser wants them */
-  augment_automaton();
-}

 
 

+/*----------------------------------------------------------------.
+| 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 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_end[symbol] points after the end of that vector.  */
-void
-new_itemsets()
+static void
+new_itemsets (void)

 {
 {

-  register int i;
-  register int shiftcount;
-  register short *isp;
-  register short *ksp;
-  register int symbol;
+  int i;
+  int shiftcount;

 
 

-#ifdef TRACE
-  fprintf(stderr, "Entering new_itemsets\n");
-#endif
+  if (trace_flag)
+    fprintf (stderr, "Entering new_itemsets, state = %d\n",
+            this_state->number);

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

-    kernel_end[i] = NULL;
+    kernel_size[i] = 0;

 
 

+  shift_symbol = XCALLOC (short, nsyms);

   shiftcount = 0;
 
   shiftcount = 0;
 

-  isp = itemset;
-
-  while (isp < itemsetend)
+  for (i = 0; i < itemsetsize; ++i)

     {
     {

-      i = *isp++;
-      symbol = ritem[i];
+      int symbol = ritem[itemset[i]];

       if (symbol > 0)
        {
       if (symbol > 0)
        {

-          ksp = kernel_end[symbol];
-
-          if (!ksp)
+         if (!kernel_size[symbol])

            {
            {

-             shift_symbol[shiftcount++] = symbol;
-             ksp = kernel_base[symbol];
+             shift_symbol[shiftcount] = symbol;
+             shiftcount++;

            }
 
            }
 

-          *ksp++ = i + 1;
-          kernel_end[symbol] = ksp;
+         kernel_base[symbol][kernel_size[symbol]] = itemset[i] + 1;
+         kernel_size[symbol]++;

        }
     }
 
        }
     }
 


@@ -239,95 +174,74 @@ new_itemsets()
 
 
 
 
 
 

-/* Use the information computed by new_itemsets to find the state numbers
-   reached by each shift transition from the current state.
+/*-----------------------------------------------------------------.
+| Subroutine of get_state.  Create a new state for those items, if |
+| necessary.                                                       |
+`-----------------------------------------------------------------*/

 
 

-   shiftset is set up as a vector of state numbers of those states.  */
-void
-append_states()
+static core *
+new_state (int symbol)

 {
 {

-  register int i;
-  register int j;
-  register int symbol;
+  core *p;

 
 

-#ifdef TRACE
-  fprintf(stderr, "Entering append_states\n");
-#endif
+  if (trace_flag)
+    fprintf (stderr, "Entering new_state, state = %d, symbol = %d (%s)\n",
+            this_state->number, symbol, tags[symbol]);

 
 

-  /* first sort shift_symbol into increasing order */
-
-  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;
-    }
+  if (nstates >= MAXSHORT)
+    fatal (_("too many states (max %d)"), MAXSHORT);

 
 

-  for (i = 0; i < nshifts; i++)
-    {
-      symbol = shift_symbol[i];
-      shiftset[i] = get_state(symbol);
-    }
-}
+  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++;

 
 

-/* 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  */
+  return p;
+}

 
 

-int
-get_state(symbol)
-int symbol;
-{
-  register int key;
-  register short *isp1;
-  register short *isp2;
-  register short *iend;
-  register core *sp;
-  register int found;

 
 

-  int n;
+/*--------------------------------------------------------------.
+| 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.        |
+`--------------------------------------------------------------*/

 
 

-#ifdef TRACE
-  fprintf(stderr, "Entering get_state, symbol = %d\n", symbol);
-#endif
+static int
+get_state (int symbol)
+{
+  int key;
+  int i;
+  core *sp;

 
 

-  isp1 = kernel_base[symbol];
-  iend = kernel_end[symbol];
-  n = iend - isp1;
+  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 */
+  /* Add up the target state's active item numbers to get a hash key.
+     */

   key = 0;
   key = 0;

-  while (isp1 < iend)
-    key += *isp1++;
-
+  for (i = 0; i < kernel_size[symbol]; ++i)
+    key += kernel_base[symbol][i];

   key = key % STATE_TABLE_SIZE;
   key = key % STATE_TABLE_SIZE;

-

   sp = state_table[key];
 
   if (sp)
     {
   sp = state_table[key];
 
   if (sp)
     {

-      found = 0;
+      int found = 0;

       while (!found)
        {
       while (!found)
        {

-         if (sp->nitems == n)
+         if (sp->nitems == kernel_size[symbol])

            {
              found = 1;
            {
              found = 1;

-             isp1 = kernel_base[symbol];
-             isp2 = sp->items;
-
-             while (found && isp1 < iend)
-               {
-                 if (*isp1++ != *isp2++)
-                   found = 0;
-               }
+             for (i = 0; i < kernel_size[symbol]; ++i)
+               if (kernel_base[symbol][i] != sp->items[i])
+                 found = 0;

            }
 
          if (!found)
            }
 
          if (!found)


@@ -336,331 +250,280 @@ int symbol;
                {
                  sp = sp->link;
                }
                {
                  sp = sp->link;
                }

-             else   /* bucket exhausted and no match */
+             else              /* bucket exhausted and no match */

                {
                {

-                 sp = sp->link = new_state(symbol);
+                 sp = sp->link = new_state (symbol);

                  found = 1;
                }
            }
        }
     }
                  found = 1;
                }
            }
        }
     }

-  else      /* bucket is empty */
+  else                         /* bucket is empty */

     {
     {

-      state_table[key] = sp = new_state(symbol);
+      state_table[key] = sp = new_state (symbol);

     }
 
     }
 

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

 
 

+  return sp->number;
+}

 
 

-/* subroutine of get_state.  create a new state for those items, if necessary.  */
+/*------------------------------------------------------------------.
+| 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.  |
+`------------------------------------------------------------------*/

 
 

-core *
-new_state(symbol)
-int symbol;
+static void
+append_states (void)

 {
 {

-  register int n;
-  register core *p;
-  register short *isp1;
-  register short *isp2;
-  register short *iend;
-
-#ifdef TRACE
-  fprintf(stderr, "Entering new_state, symbol = %d\n", symbol);
-#endif
-
-  if (nstates >= MAXSHORT)
-    toomany("states");
+  int i;
+  int j;
+  int symbol;

 
 

-  isp1 = kernel_base[symbol];
-  iend = kernel_end[symbol];
-  n = iend - isp1;
+  if (trace_flag)
+    fprintf (stderr, "Entering append_states, state = %d\n",
+            this_state->number);

 
 

-  p = (core *) xmalloc((unsigned) (sizeof(core) + (n - 1) * sizeof(short)));
-  p->accessing_symbol = symbol;
-  p->number = nstates;
-  p->nitems = n;
-
-  isp2 = p->items;
-  while (isp1 < iend)
-    *isp2++ = *isp1++;
-
-  last_state->next = p;
-  last_state = p;
+  /* first sort shift_symbol into increasing order */

 
 

-  nstates++;
+  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;
+    }

 
 

-  return (p);
+  for (i = 0; i < nshifts; i++)
+    shiftset[i] = get_state (shift_symbol[i]);

 }
 
 
 }
 
 

-void
-initialize_states()
+static void
+new_states (void)

 {
 {

-  register core *p;
-/*  register unsigned *rp1; JF unused */
-/*  register unsigned *rp2; JF unused */
-/*  register unsigned *rend; JF unused */
-
-  p = (core *) xmalloc((unsigned) (sizeof(core) - sizeof(short)));
-  first_state = last_state = this_state = p;
+  first_state = last_state = this_state = CORE_ALLOC (0);

   nstates = 1;
 }
 
 
   nstates = 1;
 }
 
 

-void
-save_shifts()
+/*---------------------------------.
+| Create a new array of N shitfs.  |
+`---------------------------------*/
+
+static shifts *
+shifts_new (int n)

 {
 {

-  register shifts *p;
-  register short *sp1;
-  register short *sp2;
-  register short *send;
+  shifts *res = SHIFTS_ALLOC (n);
+  res->nshifts = n;
+  return res;
+}

 
 

-  p = (shifts *) xmalloc((unsigned) (sizeof(shifts) +
-                                      (nshifts - 1) * sizeof(short)));

 
 

-  p->number = this_state->number;
-  p->nshifts = nshifts;
+/*------------------------------------------------------------.
+| Save the NSHIFTS of SHIFTSET into the current linked list.  |
+`------------------------------------------------------------*/

 
 

-  sp1 = shiftset;
-  sp2 = p->shifts;
-  send = shiftset + nshifts;
+static void
+save_shifts (void)
+{
+  shifts *p = shifts_new (nshifts);
+
+  p->number = this_state->number;

 
 

-  while (sp1 < send)
-    *sp2++ = *sp1++;
+  shortcpy (p->shifts, shiftset, nshifts);

 
   if (last_shift)
 
   if (last_shift)

-    {
-      last_shift->next = p;
-      last_shift = p;
-    }
+    last_shift->next = p;

   else
   else

-    {
-      first_shift = p;
-      last_shift = p;
-    }
+    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.      |
+`------------------------------------------------------------------*/

 
 

-/* find which rules can be used for reduction transitions from the current state
-   and make a reductions structure for the state to record their rule numbers.  */
-void
-save_reductions()
+static void
+insert_start_shift (void)

 {
 {

-  register short *isp;
-  register short *rp1;
-  register short *rp2;
-  register int item;
-  register int count;
-  register reductions *p;
-
-  short *rend;
-
-  /* find and count the active items that represent ends of rules */
+  core *statep;
+  shifts *sp;

 
 

-  count = 0;
-  for (isp = itemset; isp < itemsetend; isp++)
-    {
-      item = ritem[*isp];
-      if (item < 0)
-       {
-         redset[count++] = -item;
-       }
-    }
-
-  /* make a reductions structure and copy the data into it.  */
-
-  if (count)
-    {
-      p = (reductions *) xmalloc((unsigned) (sizeof(reductions) +
-                                              (count - 1) * sizeof(short)));
-
-      p->number = this_state->number;
-      p->nreds = count;
+  statep = CORE_ALLOC (0);
+  statep->number = nstates;
+  statep->accessing_symbol = start_symbol;

 
 

-      rp1 = redset;
-      rp2 = p->rules;
-      rend = rp1 + count;
+  last_state->next = statep;
+  last_state = statep;

 
 

-      while (rp1 < rend)
-       *rp2++ = *rp1++;
+  /* Make a shift from this state to (what will be) the final state.  */
+  sp = shifts_new (1);
+  sp->number = nstates++;
+  sp->shifts[0] = nstates;

 
 

-      if (last_reduction)
-       {
-         last_reduction->next = p;
-         last_reduction = p;
-       }
-      else
-       {
-         first_reduction = p;
-         last_reduction = p;
-       }
-    }
+  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.                                          |
+`------------------------------------------------------------------*/

 
 

-/* 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.  */
-void
-augment_automaton()
+static void
+augment_automaton (void)

 {
 {

-  register int i;
-  register int k;
-/*  register int found; JF unused */
-  register core *statep;
-  register shifts *sp;
-  register shifts *sp2;
-  register shifts *sp1;
+  core *statep;
+  shifts *sp;
+  shifts *sp1 = NULL;

 
   sp = first_shift;
 
 
   sp = first_shift;
 

-  if (sp)
+  if (!sp)

     {
     {

-      if (sp->number == 0)
-       {
-         k = sp->nshifts;
-         statep = first_state->next;
+      /* There are no shifts for any state.  Make one shift, from the
+        initial state to the next-to-final state.  */

 
 

-         /* The states reached by shifts from first_state are numbered 1...K.
-            Look for one reached by start_symbol.  */
-         while (statep->accessing_symbol < start_symbol
-                 && statep->number < k)
-           statep = statep->next;
+      sp = shifts_new (1);
+      sp->shifts[0] = nstates;

 
 

-         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.  */
-             k = statep->number;
+      /* Initialize the chain of shifts with sp.  */
+      first_shift = sp;
+      last_shift = sp;

 
 

-             while (sp && sp->number < k)
-               {
-                 sp1 = sp;
-                 sp = sp->next;
-               }
+      /* 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;

 
 

-             if (sp && sp->number == k)
-               {
-                 sp2 = (shifts *) xmalloc((unsigned) (sizeof(shifts)
-                                                        + sp->nshifts * sizeof(short)));
-                 sp2->number = k;
-                 sp2->nshifts = sp->nshifts + 1;
-                 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;
-                 FREE(sp);
-               }
-             else
-               {
-                 sp2 = NEW(shifts);
-                 sp2->number = k;
-                 sp2->nshifts = 1;
-                 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
+      /* 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)

            {
            {

-             /* 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 *) xmalloc(sizeof(shifts)
-                                        + sp->nshifts * sizeof(short));
-             sp2->nshifts = 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;
+             sp1 = sp;
+             sp = sp->next;
+           }

 
 

-             /* Patch sp2 into the chain of shifts
-                in place of sp, at the beginning.  */
+         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;
              sp2->next = sp->next;

-             first_shift = sp2;
-             if (last_shift == sp)
+             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;
                last_shift = sp2;

-
-             FREE(sp);
-
-             /* Create the next-to-final state, with shift to
-                what will be the final state.  */
-             insert_start_shift();

            }
        }
       else
        {
            }
        }
       else
        {

-         /* The initial state didn't even have any shifts.
-            Give it one shift, to the next-to-final state.  */
-         sp = NEW(shifts);
-         sp->nshifts = 1;
-         sp->shifts[0] = nstates;
+         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);

 
 

-         /* Patch sp into the chain of shifts at the beginning.  */
-         sp->next = first_shift;
-         first_shift = sp;
+         /* 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.  */
 
          /* Create the next-to-final state, with shift to
             what will be the final state.  */

-         insert_start_shift();
+         insert_start_shift ();

        }
     }
   else
     {
        }
     }
   else
     {

-      /* There are no shifts for any state.
-        Make one shift, from the initial state to the next-to-final state.  */
-
-      sp = NEW(shifts);
-      sp->nshifts = 1;
+      /* 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;
 
       sp->shifts[0] = nstates;
 

-      /* Initialize the chain of shifts with sp.  */
+      /* Patch sp into the chain of shifts at the beginning.  */
+      sp->next = first_shift;

       first_shift = sp;
       first_shift = sp;

-      last_shift = sp;

 
       /* Create the next-to-final state, with shift to
         what will be the final state.  */
 
       /* Create the next-to-final state, with shift to
         what will be the final state.  */

-      insert_start_shift();
+      insert_start_shift ();

     }
 
   /* 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).  */
     }
 
   /* 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 *) xmalloc((unsigned) (sizeof(core) - sizeof(short)));
+  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.  */
   statep->number = nstates;
   last_state->next = statep;
   last_state = statep;
 
   /* Make the shift from the final state to the termination state.  */

-  sp = NEW(shifts);
+  sp = shifts_new (1);

   sp->number = nstates++;
   sp->number = nstates++;

-  sp->nshifts = 1;

   sp->shifts[0] = nstates;
   last_shift->next = sp;
   last_shift = sp;
   sp->shifts[0] = nstates;
   last_shift->next = sp;
   last_shift = sp;


@@ -670,35 +533,94 @@ augment_automaton()
   final_state = nstates;
 
   /* Make the termination state.  */
   final_state = nstates;
 
   /* Make the termination state.  */

-  statep = (core *) xmalloc((unsigned) (sizeof(core) - sizeof(short)));
+  statep = CORE_ALLOC (0);

   statep->number = nstates++;
   last_state->next = statep;
   last_state = statep;
 }
 
 
   statep->number = nstates++;
   last_state->next = statep;
   last_state = statep;
 }
 
 

-/* subroutine of augment_automaton.
-   Create the next-to-final state, to which a shift has already been made in
-   the initial state.  */
+/*----------------------------------------------------------------.
+| Find which rules can be used for reduction transitions from the |
+| current state and make a reductions structure for the state to  |
+| record their rule numbers.                                      |
+`----------------------------------------------------------------*/
+
+static void
+save_reductions (void)
+{
+  int count;
+  int i;
+
+  /* Find and count the active items that represent ends of rules. */
+
+  count = 0;
+  for (i = 0; i < itemsetsize; ++i)
+    {
+      int item = ritem[itemset[i]];
+      if (item < 0)
+       redset[count++] = -item;
+    }
+
+  /* Make a reductions structure and copy the data into it.  */
+
+  if (count)
+    {
+      reductions *p = REDUCTIONS_ALLOC (count);
+
+      p->number = this_state->number;
+      p->nreds = count;
+
+      shortcpy (p->rules, redset, count);
+
+      if (last_reduction)
+       last_reduction->next = p;
+      else
+       first_reduction = p;
+      last_reduction = p;
+    }
+}
+
+\f
+/*-------------------------------------------------------------------.
+| Compute the nondeterministic finite state machine (see state.h for |
+| details) from the grammar.                                         |
+`-------------------------------------------------------------------*/
+

 void
 void

-insert_start_shift()
+generate_states (void)

 {
 {

-  register core *statep;
-  register shifts *sp;
+  allocate_storage ();
+  new_closure (nitems);
+  new_states ();

 
 

-  statep = (core *) xmalloc((unsigned) (sizeof(core) - sizeof(short)));
-  statep->number = nstates;
-  statep->accessing_symbol = start_symbol;
+  while (this_state)
+    {
+      /* 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 ();

 
 

-  last_state->next = statep;
-  last_state = statep;
+      /* create the shifts structures for the shifts to those states,
+         now that the state numbers transitioning to are known */
+      if (nshifts > 0)
+       save_shifts ();

 
 

-  /* Make a shift from this state to (what will be) the final state.  */
-  sp = NEW(shifts);
-  sp->number = nstates++;
-  sp->nshifts = 1;
-  sp->shifts[0] = nstates;
+      /* states are queued when they are created; process them all */
+      this_state = this_state->next;
+    }

 
 

-  last_shift->next = sp;
-  last_shift = sp;
+  /* discard various storage */
+  free_closure ();
+  free_storage ();
+
+  /* set up initial and final states as parser wants them */
+  augment_automaton ();

 }
 }