* src/output.c (output, prepare): Make sure the values of the

[bison.git] / src / reduce.c

diff --git a/src/reduce.c b/src/reduce.c
index 7e164c50633e0eef306fa7472db69b83248434a7..d8ea5ed60ba1f95327219cdc8cf51db90e6f10a1 100644 (file)
--- a/src/reduce.c
+++ b/src/reduce.c
@@ -54,7 +54,7 @@ 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)


@@ -264,28 +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;


@@ -300,30 +307,21 @@ reduce_grammar_tables (void)
                  while (ritem[ni++] >= 0);
                }
            }
                  while (ritem[ni++] >= 0);
                }
            }

-       }
-      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;

 
 

-    }
-#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);

     }
 }
 
     }
 }
 


@@ -338,8 +336,8 @@ nonterminals_reduce (void)
   int i, n;
   rule r;
 
   int i, n;
   rule r;
 

-  /* Create a map of nonterminal number to new nonterminal number. -1
-     in the map means it was useless and is being eliminated.  */
+  /* Map the nonterminals to their new index: useful first, useless
+     afterwards.  Kept for later report.  */

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


@@ -379,9 +377,7 @@ nonterminals_reduce (void)
 
   for (i = 1; i <= nrules; i++)
     {
 
   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];
+      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];
       if (ISVAR (rule_table[i].precsym))
        /* Can this happen?  */
        rule_table[i].precsym = nontermmap[rule_table[i].precsym];


@@ -396,7 +392,7 @@ nonterminals_reduce (void)
   nsyms -= nuseless_nonterminals;
   nvars -= nuseless_nonterminals;
 
   nsyms -= nuseless_nonterminals;
   nvars -= nuseless_nonterminals;
 

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

 }
 
 
 }
 
 


@@ -407,50 +403,46 @@ nonterminals_reduce (void)
 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");
+      int i;
+      fprintf (out, "%s\n\n", _("Useless nonterminals:"));

       for (i = 0; i < nuseless_nonterminals; ++i)
        fprintf (out, "   %s\n", tags[nsyms + i]);
       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)

          {
          {

+           rule r;

            fprintf (out, "#%-4d  ", i);
            fprintf (out, "#%-4d  ", i);

-           fprintf (out, "%s :\t", tags[rule_table[i].lhs]);
+           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


@@ -469,18 +461,22 @@ dump_grammar (FILE *out)
     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, "%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) Lhs : (@Rhs) Ritems [Num?]\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)",
+      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,
               i,

-              rule_table[i].prec,
-              rule_table[i].assoc,
-              rule_table[i].lhs,
-              rule_table[i].rhs);
+              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++)
       for (r = &ritem[rule_table[i].rhs]; *r > 0; r++)

-       fprintf (out, "%5d", *r);
-      fprintf (out, " [%d]\n", -(*r));
+       fprintf (out, "%3d", *r);
+      fprintf (out, "  [%d]\n", -(*r));

     }
   fprintf (out, "\n\n");
   fprintf (out, "Rules interpreted\n-----------------\n\n");
     }
   fprintf (out, "\n\n");
   fprintf (out, "Rules interpreted\n-----------------\n\n");