Turn on %{source,header}_extension features.

[bison.git] / src / LR0.c

diff --git a/src/LR0.c b/src/LR0.c
index 8bdcd75fb5134a1729386d1ff205b04227b36557..b37594e6d47debe94a5a8e70ce88dd8c8638abd6 100644 (file)
--- a/src/LR0.c
+++ b/src/LR0.c
@@ -1,39 +1,34 @@
 /* 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 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, Inc., 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, 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 "xalloc.h"

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

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

 
 
 int nstates;
 
 
 int nstates;


@@ -42,24 +37,6 @@ core *first_state;
 shifts *first_shift;
 reductions *first_reduction;
 
 shifts *first_shift;
 reductions *first_reduction;
 

-int get_state PARAMS((int));
-core *new_state PARAMS((int));
-
-void allocate_itemsets PARAMS((void));
-void allocate_storage PARAMS((void));
-void free_storage PARAMS((void));
-void generate_states PARAMS((void));
-void new_itemsets PARAMS((void));
-void append_states PARAMS((void));
-void initialize_states PARAMS((void));
-void save_shifts PARAMS((void));
-void save_reductions PARAMS((void));
-void augment_automaton PARAMS((void));
-void insert_start_shift PARAMS((void));
-extern void initialize_closure PARAMS((int));
-extern void closure PARAMS((short *, int));
-extern void finalize_closure PARAMS((void));
-

 static core *this_state;
 static core *last_state;
 static shifts *last_shift;
 static core *this_state;
 static core *last_state;
 static shifts *last_shift;


@@ -80,19 +57,18 @@ static short *kernel_items;
 #define        STATE_TABLE_SIZE        1009
 static core **state_table;
 
 #define        STATE_TABLE_SIZE        1009
 static core **state_table;
 

-
-
-void
+\f
+static void

 allocate_itemsets (void)
 {
 allocate_itemsets (void)
 {

-  register short *itemp;
-  register int symbol;
-  register int i;
-  register int count;
-  register short *symbol_count;
+  short *itemp;
+  int symbol;
+  int i;
+  int count;
+  short *symbol_count;

 
   count = 0;
 
   count = 0;

-  symbol_count = NEW2(nsyms, short);
+  symbol_count = XCALLOC (short, nsyms);

 
   itemp = ritem;
   symbol = *itemp++;
 
   itemp = ritem;
   symbol = *itemp++;


@@ -106,14 +82,14 @@ allocate_itemsets (void)
       symbol = *itemp++;
     }
 
       symbol = *itemp++;
     }
 

-  /* 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].
      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);
+  kernel_items = XCALLOC (short, count);

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


@@ -123,94 +99,59 @@ allocate_itemsets (void)
     }
 
   shift_symbol = symbol_count;
     }
 
   shift_symbol = symbol_count;

-  kernel_end = NEW2(nsyms, short *);
+  kernel_end = XCALLOC (short *, nsyms);

 }
 
 
 }
 
 

-void
+static void

 allocate_storage (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
+static void

 free_storage (void)
 {
 free_storage (void)
 {

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

 }
 
 
 
 }
 
 
 

-/* compute the nondeterministic finite state machine (see state.h for details)
-from the grammar.  */
-void
-generate_states (void)
-{
-  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_end[symbol] points after the end of that    |
+| vector.                                                         |
+`----------------------------------------------------------------*/

 
 

-
-
-/* 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
+static void

 new_itemsets (void)
 {
 new_itemsets (void)
 {

-  register int i;
-  register int shiftcount;
-  register short *isp;
-  register short *ksp;
-  register int symbol;
-
-#ifdef TRACE
-  fprintf(stderr, "Entering new_itemsets\n");
+  int i;
+  int shiftcount;
+  short *isp;
+  short *ksp;
+  int symbol;
+
+#if TRACE
+  fprintf (stderr, "Entering new_itemsets\n");

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


@@ -226,16 +167,16 @@ new_itemsets (void)
       symbol = ritem[i];
       if (symbol > 0)
        {
       symbol = ritem[i];
       if (symbol > 0)
        {

-          ksp = kernel_end[symbol];
+         ksp = kernel_end[symbol];

 
 

-          if (!ksp)
+         if (!ksp)

            {
              shift_symbol[shiftcount++] = symbol;
              ksp = kernel_base[symbol];
            }
 
            {
              shift_symbol[shiftcount++] = symbol;
              ksp = kernel_base[symbol];
            }
 

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

        }
     }
 
        }
     }
 


@@ -244,63 +185,70 @@ new_itemsets (void)
 
 
 
 
 
 

-/* 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 (void)
+static core *
+new_state (int symbol)

 {
 {

-  register int i;
-  register int j;
-  register int symbol;
+  int n;
+  core *p;
+  short *isp1;
+  short *isp2;
+  short *iend;

 
 

-#ifdef TRACE
-  fprintf(stderr, "Entering append_states\n");
+#if TRACE
+  fprintf (stderr, "Entering new_state, symbol = %d\n", symbol);

 #endif
 
 #endif
 

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

 
 

-  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;
-    }
+  isp1 = kernel_base[symbol];
+  iend = kernel_end[symbol];
+  n = iend - isp1;

 
 

-  for (i = 0; i < nshifts; i++)
-    {
-      symbol = shift_symbol[i];
-      shiftset[i] = get_state(symbol);
-    }
-}
+  p =
+    (core *) xcalloc ((unsigned) (sizeof (core) + (n - 1) * sizeof (short)), 1);
+  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;

 
 

+  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 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.         |
+`--------------------------------------------------------------*/

 
 

-int
+static int

 get_state (int symbol)
 {
 get_state (int symbol)
 {

-  register int key;
-  register short *isp1;
-  register short *isp2;
-  register short *iend;
-  register core *sp;
-  register int found;
+  int key;
+  short *isp1;
+  short *isp2;
+  short *iend;
+  core *sp;
+  int found;

 
   int n;
 
 
   int n;
 

-#ifdef TRACE
-  fprintf(stderr, "Entering get_state, symbol = %d\n", symbol);
+#if TRACE
+  fprintf (stderr, "Entering get_state, symbol = %d\n", symbol);

 #endif
 
   isp1 = kernel_base[symbol];
 #endif
 
   isp1 = kernel_base[symbol];


@@ -340,88 +288,83 @@ get_state (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;
 }
 
     }
 
   return sp->number;
 }
 

+/*------------------------------------------------------------------.
+| 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.  |
+`------------------------------------------------------------------*/

 
 

-
-/* subroutine of get_state.  create a new state for those items, if necessary.  */
-
-core *
-new_state (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)
-    fatal (_("too many states (max %d)"), MAXSHORT);
-
-  isp1 = kernel_base[symbol];
-  iend = kernel_end[symbol];
-  n = iend - isp1;
-
-  p = (core *) xmalloc((unsigned) (sizeof(core) + (n - 1) * sizeof(short)));
-  p->accessing_symbol = symbol;
-  p->number = nstates;
-  p->nitems = n;
+  int i;
+  int j;
+  int symbol;

 
 

-  isp2 = p->items;
-  while (isp1 < iend)
-    *isp2++ = *isp1++;
+#if TRACE
+  fprintf (stderr, "Entering append_states\n");
+#endif

 
 

-  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++)
+    {
+      symbol = shift_symbol[i];
+      shiftset[i] = get_state (symbol);
+    }

 }
 
 
 }
 
 

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

 {
 {

-  register core *p;
-/*  register unsigned *rp1; JF unused */
-/*  register unsigned *rp2; JF unused */
-/*  register unsigned *rend; JF unused */
+  core *p;

 
 

-  p = (core *) xmalloc((unsigned) (sizeof(core) - sizeof(short)));
+  p = (core *) xcalloc ((unsigned) (sizeof (core) - sizeof (short)), 1);

   first_state = last_state = this_state = p;
   nstates = 1;
 }
 
 
   first_state = last_state = this_state = p;
   nstates = 1;
 }
 
 

-void
+static void

 save_shifts (void)
 {
 save_shifts (void)
 {

-  register shifts *p;
-  register short *sp1;
-  register short *sp2;
-  register short *send;
+  shifts *p;
+  short *sp1;
+  short *sp2;
+  short *send;

 
 

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

 
   p->number = this_state->number;
   p->nshifts = nshifts;
 
   p->number = this_state->number;
   p->nshifts = nshifts;


@@ -446,80 +389,52 @@ save_shifts (void)
 }
 
 
 }
 
 

+/*------------------------------------------------------------------.
+| 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 (void)
+static void
+insert_start_shift (void)

 {
 {

-  register short *isp;
-  register short *rp1;
-  register short *rp2;
-  register int item;
-  register int count;
-  register reductions *p;
+  core *statep;
+  shifts *sp;

 
 

-  short *rend;
-
-  /* find and count the active items that represent ends of rules */
-
-  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 *) xcalloc ((unsigned) (sizeof (core) - sizeof (short)), 1);
+  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 = XCALLOC (shifts, 1);
+  sp->number = nstates++;
+  sp->nshifts = 1;
+  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
+static void

 augment_automaton (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 = NULL;
+  int i;
+  int k;
+  core *statep;
+  shifts *sp;
+  shifts *sp2;
+  shifts *sp1 = NULL;

 
   sp = first_shift;
 
 
   sp = first_shift;
 


@@ -533,13 +448,13 @@ augment_automaton (void)
          /* 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
          /* 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->number < k)

            statep = statep->next;
 
          if (statep->accessing_symbol == start_symbol)
            {
              /* We already have a next-to-final state.
            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.  */
+                Make sure it has a shift to what will be the final state.  */

              k = statep->number;
 
              while (sp && sp->number < k)
              k = statep->number;
 
              while (sp && sp->number < k)


@@ -550,8 +465,10 @@ augment_automaton (void)
 
              if (sp && sp->number == k)
                {
 
              if (sp && sp->number == k)
                {

-                 sp2 = (shifts *) xmalloc((unsigned) (sizeof(shifts)
-                                                      + sp->nshifts * sizeof(short)));
+                 sp2 = (shifts *) xcalloc ((unsigned) (sizeof (shifts)
+                                                       +
+                                                       sp->nshifts *
+                                                       sizeof (short)), 1);

                  sp2->number = k;
                  sp2->nshifts = sp->nshifts + 1;
                  sp2->shifts[0] = nstates;
                  sp2->number = k;
                  sp2->nshifts = sp->nshifts + 1;
                  sp2->shifts[0] = nstates;


@@ -564,11 +481,11 @@ augment_automaton (void)
                  sp1->next = sp2;
                  if (sp == last_shift)
                    last_shift = sp2;
                  sp1->next = sp2;
                  if (sp == last_shift)
                    last_shift = sp2;

-                 FREE(sp);
+                 XFREE (sp);

                }
              else
                {
                }
              else
                {

-                 sp2 = NEW(shifts);
+                 sp2 = XCALLOC (shifts, 1);

                  sp2->number = k;
                  sp2->nshifts = 1;
                  sp2->shifts[0] = nstates;
                  sp2->number = k;
                  sp2->nshifts = 1;
                  sp2->shifts[0] = nstates;


@@ -584,11 +501,11 @@ augment_automaton (void)
            {
              /* There is no next-to-final state as yet.  */
              /* Add one more shift in first_shift,
            {
              /* 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).  */
+                going to the next-to-final state (yet to be made).  */

              sp = first_shift;
 
              sp = first_shift;
 

-             sp2 = (shifts *) xmalloc(sizeof(shifts)
-                                        + sp->nshifts * sizeof(short));
+             sp2 = (shifts *) xcalloc (sizeof (shifts)
+                                       + sp->nshifts * sizeof (short), 1);

              sp2->nshifts = sp->nshifts + 1;
 
              /* Stick this shift into the vector at the proper place.  */
              sp2->nshifts = sp->nshifts + 1;
 
              /* Stick this shift into the vector at the proper place.  */


@@ -604,24 +521,24 @@ augment_automaton (void)
                sp2->shifts[k++] = nstates;
 
              /* Patch sp2 into the chain of shifts
                sp2->shifts[k++] = nstates;
 
              /* Patch sp2 into the chain of shifts

-                in place of sp, at the beginning.  */
+                in place of sp, at the beginning.  */

              sp2->next = sp->next;
              first_shift = sp2;
              if (last_shift == sp)
                last_shift = sp2;
 
              sp2->next = sp->next;
              first_shift = sp2;
              if (last_shift == sp)
                last_shift = sp2;
 

-             FREE(sp);
+             XFREE (sp);

 
              /* Create the next-to-final state, with shift to
 
              /* Create the next-to-final state, with shift to

-                what will be the final state.  */
-             insert_start_shift();
+                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.  */
            }
        }
       else
        {
          /* The initial state didn't even have any shifts.
             Give it one shift, to the next-to-final state.  */

-         sp = NEW(shifts);
+         sp = XCALLOC (shifts, 1);

          sp->nshifts = 1;
          sp->shifts[0] = nstates;
 
          sp->nshifts = 1;
          sp->shifts[0] = nstates;
 


@@ -631,15 +548,15 @@ augment_automaton (void)
 
          /* 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
     {
       /* There are no shifts for any state.
        }
     }
   else
     {
       /* There are no shifts for any state.

-        Make one shift, from the initial state to the next-to-final state.  */
+         Make one shift, from the initial state to the next-to-final state.  */

 
 

-      sp = NEW(shifts);
+      sp = XCALLOC (shifts, 1);

       sp->nshifts = 1;
       sp->shifts[0] = nstates;
 
       sp->nshifts = 1;
       sp->shifts[0] = nstates;
 


@@ -648,20 +565,20 @@ augment_automaton (void)
       last_shift = sp;
 
       /* Create the next-to-final state, with shift to
       last_shift = sp;
 
       /* Create the next-to-final state, with shift to

-        what will be the final state.  */
-      insert_start_shift();
+         what will be the final state.  */
+      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 *) xcalloc ((unsigned) (sizeof (core) - sizeof (short)), 1);

   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 = XCALLOC (shifts, 1);

   sp->number = nstates++;
   sp->nshifts = 1;
   sp->shifts[0] = nstates;
   sp->number = nstates++;
   sp->nshifts = 1;
   sp->shifts[0] = nstates;


@@ -673,35 +590,111 @@ augment_automaton (void)
   final_state = nstates;
 
   /* Make the termination state.  */
   final_state = nstates;
 
   /* Make the termination state.  */

-  statep = (core *) xmalloc((unsigned) (sizeof(core) - sizeof(short)));
+  statep = (core *) xcalloc ((unsigned) (sizeof (core) - sizeof (short)), 1);

   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)
+{
+  short *isp;
+  short *rp1;
+  short *rp2;
+  int item;
+  int count;
+  reductions *p;
+
+  short *rend;
+
+  /* Find and count the active items that represent ends of rules. */
+
+  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 *) xcalloc ((unsigned) (sizeof (reductions) +
+                                             (count - 1) * sizeof (short)), 1);
+
+      p->number = this_state->number;
+      p->nreds = count;
+
+      rp1 = redset;
+      rp2 = p->rules;
+      rend = rp1 + count;
+
+      for (/* nothing */; rp1 < rend; ++rp1, ++rp2)
+       *rp2 = *rp1;
+
+      if (last_reduction)
+       {
+         last_reduction->next = p;
+         last_reduction = 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 (void)
+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 ();

 }
 }