* src/derives.c (print_derives): Be sure to use `>= 0', not `> 0',

[bison.git] / src / reduce.c

diff --git a/src/reduce.c b/src/reduce.c
index b4b8dc34cfd4ee120707c6ebbde486cb2658e024..430e5b0809b04710d936f6ad6a092551bfbee23a 100644 (file)
--- a/src/reduce.c
+++ b/src/reduce.c
@@ -38,16 +38,23 @@ typedef unsigned *BSet;
 typedef short *rule;
 
 
 typedef short *rule;
 
 

-/* N is set of all nonterminals which are not useless.  P is set of
-   all rules which have no useless nonterminals in their RHS.  V is
-   the set of all accessible symbols.  */
+/* Set of all nonterminals which are not useless.  */
+static BSet N;

 
 

-static BSet N, P, V, V1;
+/* Set of all rules which have no useless nonterminals in their RHS.  */
+static BSet P;
+
+/* Set of all accessible symbols.  */
+static BSet V;
+
+/* Set of symbols used to define rule precedence (so they are
+   `useless', but no warning should be issued).  */
+static BSet V1;

 
 static int nuseful_productions;
 static int nuseless_productions;
 static int nuseful_nonterminals;
 
 static int nuseful_productions;
 static int nuseless_productions;
 static int nuseful_nonterminals;

-static int nuseless_nonterminals;
+int nuseless_nonterminals;

 \f
 static bool
 bits_equal (BSet L, BSet R, int n)
 \f
 static bool
 bits_equal (BSet L, BSet R, int n)


@@ -100,7 +107,7 @@ useful_production (int i, BSet N0)
   /* A production is useful if all of the nonterminals in its appear
      in the set of useful nonterminals.  */
 
   /* 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++)
+  for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)

     if (ISVAR (n = *r))
       if (!BITISSET (N0, n - ntokens))
        return FALSE;
     if (ISVAR (n = *r))
       if (!BITISSET (N0, n - ntokens))
        return FALSE;


@@ -257,28 +264,35 @@ inaccessable_symbols (void)
 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;
+  /* This is turned off because we would need to change the numbers in
+     the case statements in the actions file.

 
 

-      np = 0;
-      ni = 0;
-      for (pn = 1; pn <= nrules; pn++)
-       {
+     We don't disable it via CPP so that it is still checked with the
+     rest of the code, to avoid its becoming completely obsolete.
+
+     FIXME: I think the comment above demonstrates this code must be
+     turned off for *semantic* parser, not in the general case.  Try
+     to understand this better --akim.  */
+
+  if (0)
+    /* remove useless productions */
+    if (nuseless_productions > 0)
+      {
+       short np, pn, ni, pi;
+
+       np = 0;
+       ni = 0;
+       for (pn = 1; pn <= nrules; pn++)

          if (BITISSET (P, pn))
            {
              np++;
              if (pn != np)
                {
          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].lhs   = rule_table[pn].lhs;
+                 rule_table[np].line  = rule_table[pn].line;
+                 rule_table[np].prec  = rule_table[pn].prec;

                  rule_table[np].assoc = rule_table[pn].assoc;
                  rule_table[np].assoc = rule_table[pn].assoc;

-                 rule_table[np].rhs = rule_table[pn].rhs;
+                 rule_table[np].rhs   = rule_table[pn].rhs;

                  if (rule_table[np].rhs != ni)
                    {
                      pi = rule_table[np].rhs;
                  if (rule_table[np].rhs != ni)
                    {
                      pi = rule_table[np].rhs;


@@ -290,148 +304,147 @@ reduce_grammar_tables (void)
                }
              else
                {
                }
              else
                {

-                 while (ritem[ni++] >= 0);
+                 while (ritem[ni++] >= 0)
+                   /* Nothing. */;

                }
            }
                }
            }

-       }
-      ritem[ni] = 0;
-      nrules -= nuseless_productions;
-      nitems = ni;

 
 

-      /* Is it worth it to reduce the amount of memory for the
-         grammar? Probably not.  */
+       ritem[ni] = 0;
+       nrules -= nuseless_productions;
+       nitems = ni;
+       nritems = ni;

 
 

-    }
-#endif /* 0 */
-  /* Disable useless productions,
-     since they may contain useless nonterms
-     that would get mapped below to -1 and confuse everyone.  */
+       /* Is it worth it to reduce the amount of memory for the
+          grammar? Probably not.  */
+      }
+
+  /* Disable useless productions. */

   if (nuseless_productions > 0)
     {
       int pn;
   if (nuseless_productions > 0)
     {
       int pn;

-

       for (pn = 1; pn <= nrules; pn++)
       for (pn = 1; pn <= nrules; pn++)

-       {
-         if (!BITISSET (P, pn))
-           {
-             rule_table[pn].lhs = -1;
-           }
-       }
+       rule_table[pn].useful = BITISSET (P, pn);

     }
     }

+}

 
 

-  /* remove useless symbols */
-  if (nuseless_nonterminals > 0)
-    {
-
-      int i, n;
-/*      short  j; JF unused */
-      short *nontermmap;
-      rule r;
-
-      /* Create a map of nonterminal number to new nonterminal
-        number. -1 in the map means it was useless and is being
-        eliminated.  */

 
 

-      nontermmap = XCALLOC (short, nvars) - ntokens;
-      for (i = ntokens; i < nsyms; i++)
-       nontermmap[i] = -1;
+/*------------------------------.
+| Remove useless nonterminals.  |
+`------------------------------*/

 
 

-      n = ntokens;
-      for (i = ntokens; i < nsyms; i++)
-       if (BITISSET (V, i))
-         nontermmap[i] = n++;
+static void
+nonterminals_reduce (void)
+{
+  int i, n;
+  rule r;

 
 

-      /* Shuffle elements of tables indexed by symbol number.  */
+  /* Map the nonterminals to their new index: useful first, useless
+     afterwards.  Kept for later report.  */

 
 

-      for (i = ntokens; i < nsyms; i++)
-       {
-         n = nontermmap[i];
-         if (n >= 0)
-           {
-             sassoc[n] = sassoc[i];
-             sprec[n] = sprec[i];
-             tags[n] = tags[i];
-           }
-       }
-
-      /* Replace all symbol numbers in valid data structures.  */
+  short *nontermmap = XCALLOC (short, nvars) - ntokens;
+  n = ntokens;
+  for (i = ntokens; i < nsyms; i++)
+    if (BITISSET (V, i))
+      nontermmap[i] = n++;
+  for (i = ntokens; i < nsyms; i++)
+    if (!BITISSET (V, i))
+      nontermmap[i] = n++;
+
+
+  /* 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;
+
+    for (i = ntokens; i < nsyms; i++)
+      {
+       n = nontermmap[i];
+       sassoc_sorted[n] = sassoc[i];
+       sprec_sorted[n]  = sprec[i];
+       tags_sorted[n]   = tags[i];
+      }
+    for (i = ntokens; i < nsyms; i++)
+      {
+       sassoc[i] = sassoc_sorted[i];
+       sprec[i]  = sprec_sorted[i];
+       tags[i]   = tags_sorted[i];
+      }
+    free (sassoc_sorted + ntokens);
+    free (sprec_sorted + ntokens);
+    free (tags_sorted + ntokens);
+  }
+
+  /* Replace all symbol numbers in valid data structures.  */

 
 

-      for (i = 1; i <= nrules; i++)
-       {
-         /* Ignore the rules disabled above.  */
-         if (rule_table[i].lhs >= 0)
-           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 (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];
+  for (i = 0; i < nritems; ++i)
+    if (ISVAR (ritem[i]))
+      ritem[i] = nontermmap[ritem[i]];

 
 

-      start_symbol = nontermmap[start_symbol];
+  start_symbol = nontermmap[start_symbol];

 
 

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

 
 

-      free (&nontermmap[ntokens]);
-    }
+  free (nontermmap + ntokens);

 }
 
 
 }
 
 

-/*-----------------------------------------------------------------.
-| Ouput the detailed results of the reductions.  For FILE.output.  |
-`-----------------------------------------------------------------*/
+/*------------------------------------------------------------------.
+| Output the detailed results of the reductions.  For FILE.output.  |
+`------------------------------------------------------------------*/

 
 void
 reduce_output (FILE *out)
 {
 
 void
 reduce_output (FILE *out)
 {

-  int i;
-  rule r;
-  bool b;
-

   if (nuseless_nonterminals > 0)
     {
   if (nuseless_nonterminals > 0)
     {

-      fprintf (out, _("Useless nonterminals:"));
-      fprintf (out, "\n\n");
-      for (i = ntokens; i < nsyms; i++)
-       if (!BITISSET (V, i))
-         fprintf (out, "   %s\n", tags[i]);
+      int i;
+      fprintf (out, "%s\n\n", _("Useless nonterminals:"));
+      for (i = 0; i < nuseless_nonterminals; ++i)
+       fprintf (out, "   %s\n", tags[nsyms + i]);
+      fputs ("\n\n", out);

     }
     }

-  b = FALSE;
-  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 (!b)
       if (!BITISSET (V, i) && !BITISSET (V1, i))
        {
          if (!b)

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

          fprintf (out, "   %s\n", tags[i]);
        }
          fprintf (out, "   %s\n", tags[i]);
        }

-    }
+    if (b)
+      fputs ("\n\n", out);
+  }

 
   if (nuseless_productions > 0)
     {
 
   if (nuseless_productions > 0)
     {

-      fprintf (out, "\n\n");
-      fprintf (out, _("Useless rules:"));
-      fprintf (out, "\n\n");
+      int i;
+      fprintf (out, "%s\n\n", _("Useless rules:"));

       for (i = 1; i <= nrules; i++)
       for (i = 1; i <= nrules; i++)

-       if (!BITISSET (P, i))
+       if (!rule_table[i].useful)

          {
          {

-           fprintf (out, "#%-4d  ", i);
-           fprintf (out, "%s :\t", tags[rule_table[i].lhs]);
+           rule r;
+           fprintf (out, "#%-4d  ", i - 1);
+           fprintf (out, "%s:", tags[rule_table[i].lhs]);

            for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)
              fprintf (out, " %s", tags[*r]);
            for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)
              fprintf (out, " %s", tags[*r]);

-           fprintf (out, ";\n");
+           fputs (";\n", out);

          }
          }

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

     }
     }

-  if (nuseless_nonterminals > 0 || nuseless_productions > 0 || b)
-    fprintf (out, "\n\n");

 }
 \f
 static void
 }
 \f
 static void


@@ -442,32 +455,37 @@ dump_grammar (FILE *out)
 
   fprintf (out, "REDUCED GRAMMAR\n\n");
   fprintf (out,
 
   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"));
+          "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++)
   for (i = ntokens; i < nsyms; i++)

-    fprintf (out, "%5d  %5d  %5d  %s\n", i, sprec[i], sassoc[i], tags[i]);
+    fprintf (out, "%5d  %5d   %5d  %s\n", i, sprec[i], sassoc[i], tags[i]);

   fprintf (out, "\n\n");
   fprintf (out, "\n\n");

-  fprintf (out, _("Rules\n-----\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++)
     {
   for (i = 1; i <= nrules; i++)
     {

-      fprintf (out, "%-5d(%5d%5d)%5d : (@%-5d)",
-              i,
-              rule_table[i].prec,
-              rule_table[i].assoc,
-              rule_table[i].lhs,
-              rule_table[i].rhs);
-      for (r = &ritem[rule_table[i].rhs]; *r > 0; r++)
-       fprintf (out, "%5d", *r);
-      fprintf (out, " [%d]\n", -(*r));
+      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 - 1,
+              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) - 1);

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

-  fprintf (out, _("Rules interpreted\n-----------------\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 (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++)
+      for (r = &ritem[rule_table[i].rhs]; *r >= 0; r++)

        fprintf (out, " %s", tags[*r]);
       fputc ('\n', out);
     }
        fprintf (out, " %s", tags[*r]);
       fputc ('\n', out);
     }


@@ -484,24 +502,27 @@ static void
 reduce_print (void)
 {
   if (yacc_flag && nuseless_productions)
 reduce_print (void)
 {
   if (yacc_flag && nuseless_productions)

-    fprintf (stderr, _("%d rules never reduced\n"), nuseless_productions);
+    fprintf (stderr, ngettext ("%d rule never reduced\n",
+                              "%d rules never reduced\n",
+                              nuseless_productions),
+            nuseless_productions);

 
   fprintf (stderr, _("%s contains "), infile);
 
   if (nuseless_nonterminals > 0)
 
   fprintf (stderr, _("%s contains "), infile);
 
   if (nuseless_nonterminals > 0)

-    {
-      fprintf (stderr, _("%d useless nonterminal%s"),
-              nuseless_nonterminals,
-              (nuseless_nonterminals == 1 ? "" : "s"));
-    }
+    fprintf (stderr, ngettext ("%d useless nonterminal",
+                              "%d useless nonterminals",
+                              nuseless_nonterminals),
+            nuseless_nonterminals);
+

   if (nuseless_nonterminals > 0 && nuseless_productions > 0)
     fprintf (stderr, _(" and "));
 
   if (nuseless_productions > 0)
   if (nuseless_nonterminals > 0 && nuseless_productions > 0)
     fprintf (stderr, _(" and "));
 
   if (nuseless_productions > 0)

-    {
-      fprintf (stderr, _("%d useless rule%s"),
-              nuseless_productions, (nuseless_productions == 1 ? "" : "s"));
-    }
+    fprintf (stderr, ngettext ("%d useless rule",
+                              "%d useless rules",
+                              nuseless_productions),
+            nuseless_productions);

   fprintf (stderr, "\n");
   fflush (stderr);
 }
   fprintf (stderr, "\n");
   fflush (stderr);
 }


@@ -533,6 +554,8 @@ reduce_grammar (void)
           tags[start_symbol]);
 
   reduce_grammar_tables ();
           tags[start_symbol]);
 
   reduce_grammar_tables ();

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

 
   if (trace_flag)
     {
 
   if (trace_flag)
     {