* src/symtab.h, src/symtab.c (symbol_t): destructor_location is a

[bison.git] / src / reduce.c

diff --git a/src/reduce.c b/src/reduce.c
index 87a2a1a977148c2e15eac43e99cd5d04f86f6960..35aab2e725e69edb73c81d6a9c40bf2b739eee24 100644 (file)
--- a/src/reduce.c
+++ b/src/reduce.c
@@ -1,5 +1,5 @@
 /* Grammar reduction for Bison.
 /* Grammar reduction for Bison.

-   Copyright 1988, 1989, 2000, 2001  Free Software Foundation, Inc.
+   Copyright (C) 1988, 1989, 2000, 2001, 2002  Free Software Foundation, Inc.

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


@@ -26,72 +26,35 @@
    user's parser.  */
 
 #include "system.h"
    user's parser.  */
 
 #include "system.h"

+#include "quotearg.h"

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

+#include "symtab.h"

 #include "gram.h"
 #include "complain.h"
 #include "reduce.h"
 #include "reader.h"
 #include "getargs.h"
 #include "gram.h"
 #include "complain.h"
 #include "reduce.h"
 #include "reader.h"
 #include "getargs.h"

-
-typedef unsigned *BSet;
-typedef short *rule;
-
+#include "bitset.h"

 
 /* Set of all nonterminals which are not useless.  */
 
 /* Set of all nonterminals which are not useless.  */

-static BSet N;
+static bitset N;

 
 /* Set of all rules which have no useless nonterminals in their RHS.  */
 
 /* Set of all rules which have no useless nonterminals in their RHS.  */

-static BSet P;
+static bitset P;

 
 /* Set of all accessible symbols.  */
 
 /* Set of all accessible symbols.  */

-static BSet V;
+static bitset V;

 
 /* Set of symbols used to define rule precedence (so they are
    `useless', but no warning should be issued).  */
 
 /* Set of symbols used to define rule precedence (so they are
    `useless', but no warning should be issued).  */

-static BSet V1;
+static bitset V1;

 
 static int nuseful_productions;
 
 static int nuseful_productions;

-static int nuseless_productions;
+int nuseless_productions;

 static int nuseful_nonterminals;
 int nuseless_nonterminals;
 \f
 static int nuseful_nonterminals;
 int nuseless_nonterminals;
 \f

-static bool
-bits_equal (BSet L, BSet R, int n)
-{
-  int i;
-
-  for (i = n - 1; i >= 0; i--)
-    if (L[i] != R[i])
-      return FALSE;
-  return TRUE;
-}
-
-
-static int
-nbits (unsigned i)
-{
-  int count = 0;
-
-  while (i != 0)
-    {
-      i ^= (i & ((unsigned) (-(int) i)));
-      ++count;
-    }
-  return count;
-}
-
-
-static int
-bits_size (BSet S, int n)
-{
-  int i, count = 0;
-
-  for (i = n - 1; i >= 0; i--)
-    count += nbits (S[i]);
-  return count;
-}
-\f

 /*-------------------------------------------------------------------.
 | Another way to do this would be with a set for each production and |
 | then do subset tests against N0, but even for the C grammar the    |
 /*-------------------------------------------------------------------.
 | Another way to do this would be with a set for each production and |
 | then do subset tests against N0, but even for the C grammar the    |


@@ -99,18 +62,17 @@ bits_size (BSet S, int n)
 `-------------------------------------------------------------------*/
 
 static bool
 `-------------------------------------------------------------------*/
 
 static bool

-useful_production (int i, BSet N0)
+useful_production (int i, bitset N0)

 {
 {

-  rule r;
+  item_number_t *r;

   short n;
 
   /* A production is useful if all of the nonterminals in its appear
      in the set of useful nonterminals.  */
 
   short n;
 
   /* A production is useful if all of the nonterminals in its appear
      in the set of useful nonterminals.  */
 

-  for (r = &ritem[rule_table[i].rhs]; *r > 0; r++)
-    if (ISVAR (n = *r))
-      if (!BITISSET (N0, n - ntokens))
-       return FALSE;
+  for (r = rules[i].rhs; *r >= 0; r++)
+    if (ISVAR (n = *r) && !bitset_test (N0, n - ntokens))
+      return FALSE;

   return TRUE;
 }
 
   return TRUE;
 }
 


@@ -122,13 +84,14 @@ useful_production (int i, BSet N0)
 static void
 useless_nonterminals (void)
 {
 static void
 useless_nonterminals (void)
 {

-  BSet Np, Ns;
+  bitset Np, Ns;

   int i;
 
   /* N is set as built.  Np is set being built this iteration. P is
      set of all productions which have a RHS all in N.  */
 
   int i;
 
   /* N is set as built.  Np is set being built this iteration. P is
      set of all productions which have a RHS all in N.  */
 

-  Np = XCALLOC (unsigned, WORDSIZE (nvars));
+  Np = bitset_create (nvars, BITSET_FIXED);
+

 
   /* The set being computed is a set of nonterminals which can derive
      the empty string or strings consisting of all terminals. At each
 
   /* The set being computed is a set of nonterminals which can derive
      the empty string or strings consisting of all terminals. At each


@@ -148,26 +111,21 @@ useless_nonterminals (void)
 
   while (1)
     {
 
   while (1)
     {

-      for (i = WORDSIZE (nvars) - 1; i >= 0; i--)
-       Np[i] = N[i];
-      for (i = 1; i <= nrules; i++)
-       {
-         if (!BITISSET (P, i))
-           {
-             if (useful_production (i, N))
-               {
-                 SETBIT (Np, rule_table[i].lhs - ntokens);
-                 SETBIT (P, i);
-               }
-           }
-       }
-      if (bits_equal (N, Np, WORDSIZE (nvars)))
+      bitset_copy (Np, N);
+      for (i = 1; i < nrules + 1; i++)
+       if (!bitset_test (P, i)
+           && useful_production (i, N))
+         {
+           bitset_set (Np, rules[i].lhs->number - ntokens);
+           bitset_set (P, i);
+         }
+      if (bitset_equal_p (N, Np))

        break;
       Ns = Np;
       Np = N;
       N = Ns;
     }
        break;
       Ns = Np;
       Np = N;
       N = Ns;
     }

-  XFREE (N);
+  bitset_free (N);

   N = Np;
 }
 
   N = Np;
 }
 


@@ -175,10 +133,10 @@ useless_nonterminals (void)
 static void
 inaccessable_symbols (void)
 {
 static void
 inaccessable_symbols (void)
 {

-  BSet Vp, Vs, Pp;
+  bitset Vp, Vs, Pp;

   int i;
   short t;
   int i;
   short t;

-  rule r;
+  item_number_t *r;

 
   /* Find out which productions are reachable and which symbols are
      used.  Starting with an empty set of productions and a set of
 
   /* Find out which productions are reachable and which symbols are
      used.  Starting with an empty set of productions and a set of


@@ -203,31 +161,30 @@ inaccessable_symbols (void)
      terminals are printed (if running in verbose mode) so that the
      user can know.  */
 
      terminals are printed (if running in verbose mode) so that the
      user can know.  */
 

-  Vp = XCALLOC (unsigned, WORDSIZE (nsyms));
-  Pp = XCALLOC (unsigned, WORDSIZE (nrules + 1));
+  Vp = bitset_create (nsyms, BITSET_FIXED);
+  Pp = bitset_create (nrules + 1, BITSET_FIXED);

 
   /* If the start symbol isn't useful, then nothing will be useful. */
 
   /* If the start symbol isn't useful, then nothing will be useful. */

-  if (BITISSET (N, start_symbol - ntokens))
+  if (bitset_test (N, axiom->number - ntokens))

     {
     {

-      SETBIT (V, start_symbol);
+      bitset_set (V, axiom->number);

 
       while (1)
        {
 
       while (1)
        {

-         for (i = WORDSIZE (nsyms) - 1; i >= 0; i--)
-           Vp[i] = V[i];
-         for (i = 1; i <= nrules; i++)
+         bitset_copy (Vp, V);
+         for (i = 1; i < nrules + 1; i++)

            {
            {

-             if (!BITISSET (Pp, i)
-                 && BITISSET (P, i)
-                 && BITISSET (V, rule_table[i].lhs))
+             if (!bitset_test (Pp, i)
+                 && bitset_test (P, i)
+                 && bitset_test (V, rules[i].lhs->number))

                {
                {

-                 for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)
-                   if (ISTOKEN (t = *r) || BITISSET (N, t - ntokens))
-                     SETBIT (Vp, t);
-                 SETBIT (Pp, i);
+                 for (r = rules[i].rhs; *r >= 0; r++)
+                   if (ISTOKEN (t = *r) || bitset_test (N, t - ntokens))
+                     bitset_set (Vp, t);
+                 bitset_set (Pp, i);

                }
            }
                }
            }

-         if (bits_equal (V, Vp, WORDSIZE (nsyms)))
+         if (bitset_equal_p (V, Vp))

            break;
          Vs = Vp;
          Vp = V;
            break;
          Vs = Vp;
          Vp = V;


@@ -235,88 +192,90 @@ inaccessable_symbols (void)
        }
     }
 
        }
     }
 

-  XFREE (V);
+  bitset_free (V);

   V = Vp;
 
   /* Tokens 0, 1, and 2 are internal to Bison.  Consider them useful. */
   V = Vp;
 
   /* Tokens 0, 1, and 2 are internal to Bison.  Consider them useful. */

-  SETBIT (V, 0);               /* end-of-input token */
-  SETBIT (V, 1);               /* error token */
-  SETBIT (V, 2);               /* some undefined token */
+  bitset_set (V, eoftoken->number);            /* end-of-input token */
+  bitset_set (V, errtoken->number);            /* error token */
+  bitset_set (V, undeftoken->number);          /* some undefined token */

 
 

-  XFREE (P);
+  bitset_free (P);

   P = Pp;
 
   P = Pp;
 

-  nuseful_productions = bits_size (P, WORDSIZE (nrules + 1));
+  nuseful_productions = bitset_count (P);

   nuseless_productions = nrules - nuseful_productions;
 
   nuseful_nonterminals = 0;
   for (i = ntokens; i < nsyms; i++)
   nuseless_productions = nrules - nuseful_productions;
 
   nuseful_nonterminals = 0;
   for (i = ntokens; i < nsyms; i++)

-    if (BITISSET (V, i))
+    if (bitset_test (V, i))

       nuseful_nonterminals++;
   nuseless_nonterminals = nvars - nuseful_nonterminals;
 
   /* A token that was used in %prec should not be warned about.  */
       nuseful_nonterminals++;
   nuseless_nonterminals = nvars - nuseful_nonterminals;
 
   /* A token that was used in %prec should not be warned about.  */

-  for (i = 1; i < nrules; i++)
-    if (rule_table[i].precsym != 0)
-      SETBIT (V1, rule_table[i].precsym);
+  for (i = 1; i < nrules + 1; i++)
+    if (rules[i].precsym != 0)
+      bitset_set (V1, rules[i].precsym->number);

 }
 
 }
 

+
+/*-------------------------------------------------------------------.
+| Put the useless productions at the end of RULES, and adjust NRULES |
+| accordingly.                                                       |
+`-------------------------------------------------------------------*/
+

 static void
 reduce_grammar_tables (void)
 {
 static void
 reduce_grammar_tables (void)
 {

-/* This is turned off because we would need to change the numbers
-   in the case statements in the actions file.  */
-#if 0
-  /* remove useless productions */
-  if (nuseless_productions > 0)
-    {
-      short np, pn, ni, pi;
+  /* Report and flag useless productions.  */
+  {
+    int r;
+    for (r = 1; r < nrules + 1; r++)
+      {
+       rules[r].useful = bitset_test (P, r);
+       if (!rules[r].useful)
+         {
+           LOCATION_PRINT (stderr, rules[r].location);
+           fprintf (stderr, ": %s: %s: ", _("warning"), _("useless rule"));
+           rule_print (&rules[r], stderr);
+         }
+      }
+  }

 
 

-      np = 0;
-      ni = 0;
-      for (pn = 1; pn <= nrules; pn++)
-       {
-         if (BITISSET (P, pn))
-           {
-             np++;
-             if (pn != np)
-               {
-                 rule_table[np].lhs = rule_table[pn].lhs;
-                 rline[np] = rline[pn];
-                 rule_table[np].prec = rule_table[pn].prec;
-                 rule_table[np].assoc = rule_table[pn].assoc;
-                 rule_table[np].rhs = rule_table[pn].rhs;
-                 if (rule_table[np].rhs != ni)
-                   {
-                     pi = rule_table[np].rhs;
-                     rule_table[np].rhs = ni;
-                     while (ritem[pi] >= 0)
-                       ritem[ni++] = ritem[pi++];
-                     ritem[ni++] = -np;
-                   }
-               }
-             else
-               {
-                 while (ritem[ni++] >= 0);
-               }
-           }
-       }
-      ritem[ni] = 0;
-      nrules -= nuseless_productions;
-      nitems = ni;
+  /* Map the nonterminals to their new index: useful first, useless
+     afterwards.  Kept for later report.  */
+  {
+    int useful = 1;
+    int useless = nrules + 1 - nuseless_productions;
+    rule_t *rules_sorted = XMALLOC (rule_t, nrules + 1) - 1;
+    int i;
+    for (i = 1; i < nrules + 1; ++i)
+      rules_sorted[rules[i].useful ? useful++ : useless++] = rules[i];
+    free (rules + 1);
+    rules = rules_sorted;

 
 

-      /* Is it worth it to reduce the amount of memory for the
-         grammar? Probably not.  */
+    /* Renumber the rules markers in RITEMS.  */
+    for (i = 1; i < nrules + 1; ++i)
+      {
+       item_number_t *rhsp = rules[i].rhs;
+       for (/* Nothing. */; *rhsp >= 0; ++rhsp)
+         /* Nothing. */;
+       *rhsp = -i;
+       rules[i].number = i;
+      }
+    nrules -= nuseless_productions;
+  }

 
 

-    }
-#endif /* 0 */
-  /* Disable useless productions. */
-  if (nuseless_productions > 0)
-    {
-      int pn;
-      for (pn = 1; pn <= nrules; pn++)
-       rule_table[pn].useful = BITISSET (P, pn);
-    }
+  /* Adjust NRITEMS.  */
+  {
+    int r;
+    int length;
+    for (r = nrules + 1; r < nrules + 1 + nuseless_productions; ++r)
+      {
+       length = rule_rhs_length (&rules[r]);
+       nritems -= length + 1;
+      }
+  }

 }
 
 
 }
 
 


@@ -327,62 +286,52 @@ reduce_grammar_tables (void)
 static void
 nonterminals_reduce (void)
 {
 static void
 nonterminals_reduce (void)
 {

-  int i, n;
-  rule r;
+  symbol_number_t i, n;

 
   /* Map the nonterminals to their new index: useful first, useless
      afterwards.  Kept for later report.  */
 
 
   /* Map the nonterminals to their new index: useful first, useless
      afterwards.  Kept for later report.  */
 

-  short *nontermmap = XCALLOC (short, nvars) - ntokens;
+  symbol_number_t *nontermmap = XCALLOC (symbol_number_t, nvars) - ntokens;

   n = ntokens;
   for (i = ntokens; i < nsyms; i++)
   n = ntokens;
   for (i = ntokens; i < nsyms; i++)

-    if (BITISSET (V, i))
+    if (bitset_test (V, i))

       nontermmap[i] = n++;
   for (i = ntokens; i < nsyms; i++)
       nontermmap[i] = n++;
   for (i = ntokens; i < nsyms; i++)

-    if (!BITISSET (V, i))
-      nontermmap[i] = n++;
+    if (!bitset_test (V, i))
+      {
+       nontermmap[i] = n++;
+       LOCATION_PRINT (stderr, symbols[i]->location);
+       fprintf (stderr, ": %s: %s: %s\n",
+                _("warning"), _("useless nonterminal"),
+                symbol_tag_get (symbols[i]));
+      }

 
 
   /* Shuffle elements of tables indexed by symbol number.  */
   {
 
 
   /* Shuffle elements of tables indexed by symbol number.  */
   {

-    short *sassoc_sorted = XMALLOC (short, nvars) - ntokens;
-    short *sprec_sorted  = XMALLOC (short, nvars) - ntokens;
-    char **tags_sorted   = XMALLOC (char *, nvars) - ntokens;
+    symbol_t **symbols_sorted = XMALLOC (symbol_t *, nvars) - ntokens;

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

-      {
-       n = nontermmap[i];
-       sassoc_sorted[n] = sassoc[i];
-       sprec_sorted[n]  = sprec[i];
-       tags_sorted[n]   = tags[i];
-      }
+      symbols[i]->number = nontermmap[i];

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

+      symbols_sorted[nontermmap[i]] = symbols[i];
+    for (i = ntokens; i < nsyms; i++)
+      symbols[i] = symbols_sorted[i];
+    free (symbols_sorted + ntokens);
+  }
+
+  {
+    int r;
+    for (r = 1; r < nrules + 1; ++r)

       {
       {

-       sassoc[i] = sassoc_sorted[i];
-       sprec[i]  = sprec_sorted[i];
-       tags[i]   = tags_sorted[i];
+       item_number_t *rhsp;
+       for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)
+         if (ISVAR (*rhsp))
+           *rhsp =  symbol_number_as_item_number (nontermmap[*rhsp]);

       }
       }

-    free (sassoc_sorted + ntokens);
-    free (sprec_sorted + ntokens);
-    free (tags_sorted + ntokens);
+    axiom->number = nontermmap[axiom->number];

   }
 
   }
 

-  /* Replace all symbol numbers in valid data structures.  */
-
-  for (i = 1; i <= nrules; i++)
-    {
-      rule_table[i].lhs = nontermmap[rule_table[i].lhs];
-      if (ISVAR (rule_table[i].precsym))
-       /* Can this happen?  */
-       rule_table[i].precsym = nontermmap[rule_table[i].precsym];
-    }
-
-  for (r = ritem; *r; r++)
-    if (ISVAR (*r))
-      *r = nontermmap[*r];
-
-  start_symbol = nontermmap[start_symbol];
-

   nsyms -= nuseless_nonterminals;
   nvars -= nuseless_nonterminals;
 
   nsyms -= nuseless_nonterminals;
   nvars -= nuseless_nonterminals;
 


@@ -402,7 +351,7 @@ reduce_output (FILE *out)
       int i;
       fprintf (out, "%s\n\n", _("Useless nonterminals:"));
       for (i = 0; i < nuseless_nonterminals; ++i)
       int i;
       fprintf (out, "%s\n\n", _("Useless nonterminals:"));
       for (i = 0; i < nuseless_nonterminals; ++i)

-       fprintf (out, "   %s\n", tags[nsyms + i]);
+       fprintf (out, "   %s\n", symbol_tag_get (symbols[nsyms + i]));

       fputs ("\n\n", out);
     }
 
       fputs ("\n\n", out);
     }
 


@@ -410,79 +359,24 @@ reduce_output (FILE *out)
     bool b = FALSE;
     int i;
     for (i = 0; i < ntokens; i++)
     bool b = FALSE;
     int i;
     for (i = 0; i < ntokens; i++)

-      if (!BITISSET (V, i) && !BITISSET (V1, i))
+      if (!bitset_test (V, i) && !bitset_test (V1, i))

        {
          if (!b)
            fprintf (out, "%s\n\n", _("Terminals which are not used:"));
          b = TRUE;
        {
          if (!b)
            fprintf (out, "%s\n\n", _("Terminals which are not used:"));
          b = TRUE;

-         fprintf (out, "   %s\n", tags[i]);
+         fprintf (out, "   %s\n", symbol_tag_get (symbols[i]));

        }
     if (b)
       fputs ("\n\n", out);
   }
 
   if (nuseless_productions > 0)
        }
     if (b)
       fputs ("\n\n", out);
   }
 
   if (nuseless_productions > 0)

-    {
-      int i;
-      fprintf (out, "%s\n\n", _("Useless rules:"));
-      for (i = 1; i <= nrules; i++)
-       if (!rule_table[i].useful)
-         {
-           rule r;
-           fprintf (out, "#%-4d  ", i);
-           fprintf (out, "%s:", tags[rule_table[i].lhs]);
-           for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)
-             fprintf (out, " %s", tags[*r]);
-           fputs (";\n", out);
-         }
-      fputs ("\n\n", out);
-    }
+    grammar_rules_partial_print (out, _("Useless rules"),
+                                nrules + 1,
+                                nuseless_productions + nrules + 1);

 }
 \f
 }
 \f

-static void
-dump_grammar (FILE *out)
-{
-  int i;
-  rule r;
-
-  fprintf (out, "REDUCED GRAMMAR\n\n");
-  fprintf (out,
-          "ntokens = %d, nvars = %d, nsyms = %d, nrules = %d, nitems = %d\n\n",
-          ntokens, nvars, nsyms, nrules, nitems);
-  fprintf (out, "Variables\n---------\n\n");
-  fprintf (out, "Value  Sprec  Sassoc  Tag\n");
-  for (i = ntokens; i < nsyms; i++)
-    fprintf (out, "%5d  %5d   %5d  %s\n", i, sprec[i], sassoc[i], tags[i]);
-  fprintf (out, "\n\n");
-  fprintf (out, "Rules\n-----\n\n");
-  fprintf (out, "Num (Prec, Assoc, Useful, Ritem Range) Lhs -> Rhs (Ritem range) [Num]\n");
-  for (i = 1; i <= nrules; i++)
-    {
-      int rhs_count = 0;
-      /* Find the last RHS index in ritems. */
-      for (r = &ritem[rule_table[i].rhs]; *r > 0; ++r)
-       ++rhs_count;
-      fprintf (out, "%3d (%2d, %2d, %2d, %2d-%2d)   %2d ->",
-              i,
-              rule_table[i].prec, rule_table[i].assoc, rule_table[i].useful,
-              rule_table[i].rhs, rule_table[i].rhs + rhs_count - 1,
-              rule_table[i].lhs);
-      /* Dumped the RHS. */
-      for (r = &ritem[rule_table[i].rhs]; *r > 0; r++)
-       fprintf (out, "%3d", *r);
-      fprintf (out, "  [%d]\n", -(*r));
-    }
-  fprintf (out, "\n\n");
-  fprintf (out, "Rules interpreted\n-----------------\n\n");
-  for (i = 1; i <= nrules; i++)
-    {
-      fprintf (out, "%-5d  %s :", i, tags[rule_table[i].lhs]);
-      for (r = &ritem[rule_table[i].rhs]; *r > 0; r++)
-       fprintf (out, " %s", tags[*r]);
-      fputc ('\n', out);
-    }
-  fprintf (out, "\n\n");
-}
+

 
 
 
 
 
 


@@ -499,7 +393,7 @@ reduce_print (void)
                               nuseless_productions),
             nuseless_productions);
 
                               nuseless_productions),
             nuseless_productions);
 

-  fprintf (stderr, _("%s contains "), infile);
+  fprintf (stderr, "%s: %s: ", infile, _("warning"));

 
   if (nuseless_nonterminals > 0)
     fprintf (stderr, ngettext ("%d useless nonterminal",
 
   if (nuseless_nonterminals > 0)
     fprintf (stderr, ngettext ("%d useless nonterminal",


@@ -526,32 +420,35 @@ reduce_grammar (void)
 
   /* Allocate the global sets used to compute the reduced grammar */
 
 
   /* Allocate the global sets used to compute the reduced grammar */
 

-  N = XCALLOC (unsigned, WORDSIZE (nvars));
-  P = XCALLOC (unsigned, WORDSIZE (nrules + 1));
-  V = XCALLOC (unsigned, WORDSIZE (nsyms));
-  V1 = XCALLOC (unsigned, WORDSIZE (nsyms));
+  N = bitset_create (nvars, BITSET_FIXED);
+  P =  bitset_create (nrules + 1, BITSET_FIXED);
+  V = bitset_create (nsyms, BITSET_FIXED);
+  V1 = bitset_create (nsyms, BITSET_FIXED);

 
   useless_nonterminals ();
   inaccessable_symbols ();
 
   reduced = (bool) (nuseless_nonterminals + nuseless_productions > 0);
 
   useless_nonterminals ();
   inaccessable_symbols ();
 
   reduced = (bool) (nuseless_nonterminals + nuseless_productions > 0);

-

   if (!reduced)
     return;
 
   reduce_print ();
 
   if (!reduced)
     return;
 
   reduce_print ();
 

-  if (!BITISSET (N, start_symbol - ntokens))
+  if (!bitset_test (N, axiom->number - ntokens))

     fatal (_("Start symbol %s does not derive any sentence"),
     fatal (_("Start symbol %s does not derive any sentence"),

-          tags[start_symbol]);
+          symbol_tag_get (symbols[axiom->number]));

 
 

-  reduce_grammar_tables ();
+  /* First reduce the nonterminals, as they renumber themselves in the
+     whole grammar.  If you change the order, nonterms would be
+     renumbered only in the reduced grammar.  */

   if (nuseless_nonterminals > 0)
     nonterminals_reduce ();
   if (nuseless_nonterminals > 0)
     nonterminals_reduce ();

+  if (nuseless_productions > 0)
+    reduce_grammar_tables ();

 
   if (trace_flag)
     {
 
   if (trace_flag)
     {

-      dump_grammar (stderr);
+      grammar_dump (stderr, "Reduced Grammar");

 
       fprintf (stderr, "reduced %s defines %d terminals, %d nonterminals\
 , and %d productions.\n",
 
       fprintf (stderr, "reduced %s defines %d terminals, %d nonterminals\
 , and %d productions.\n",


@@ -567,8 +464,8 @@ reduce_grammar (void)
 void
 reduce_free (void)
 {
 void
 reduce_free (void)
 {

-  XFREE (N);
-  XFREE (V);
-  XFREE (V1);
-  XFREE (P);
+  bitset_free (N);
+  bitset_free (V);
+  bitset_free (V1);
+  bitset_free (P);

 }
 }