* lib/hash.h (__P): Added definition for this macro.

[bison.git] / src / reduce.c

diff --git a/src/reduce.c b/src/reduce.c
index 991034d138300b7a8f71bd3457a6f8193f360ee4..0beff91a90f76abd4bc196ecdba7796302cd0196 100644 (file)
--- a/src/reduce.c
+++ b/src/reduce.c
@@ -28,6 +28,7 @@
 #include "system.h"
 #include "getargs.h"
 #include "files.h"
 #include "system.h"
 #include "getargs.h"
 #include "files.h"

+#include "symtab.h"

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


@@ -38,16 +39,23 @@ 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 +108,7 @@ 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[rrhs[i]]; *r > 0; r++)
+  for (r = &ritem[rules[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;


@@ -149,7 +157,7 @@ useless_nonterminals (void)
            {
              if (useful_production (i, N))
                {
            {
              if (useful_production (i, N))
                {

-                 SETBIT (Np, rlhs[i] - ntokens);
+                 SETBIT (Np, rules[i].lhs - ntokens);

                  SETBIT (P, i);
                }
            }
                  SETBIT (P, i);
                }
            }


@@ -200,38 +208,33 @@ inaccessable_symbols (void)
   Pp = XCALLOC (unsigned, WORDSIZE (nrules + 1));
 
   /* If the start symbol isn't useful, then nothing will be useful. */
   Pp = XCALLOC (unsigned, WORDSIZE (nrules + 1));
 
   /* If the start symbol isn't useful, then nothing will be useful. */

-  if (!BITISSET (N, start_symbol - ntokens))
-    goto end_iteration;
-
-  SETBIT (V, start_symbol);
-
-  while (1)
+  if (BITISSET (N, start_symbol - ntokens))

     {
     {

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

        {
        {

-         if (!BITISSET (Pp, i) && BITISSET (P, i) && BITISSET (V, rlhs[i]))
+         for (i = WORDSIZE (nsyms) - 1; i >= 0; i--)
+           Vp[i] = V[i];
+         for (i = 1; i <= nrules; i++)

            {
            {

-             for (r = &ritem[rrhs[i]]; *r >= 0; r++)
+             if (!BITISSET (Pp, i)
+                 && BITISSET (P, i)
+                 && BITISSET (V, rules[i].lhs))

                {
                {

-                 if (ISTOKEN (t = *r) || BITISSET (N, t - ntokens))
-                   {
+                 for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
+                   if (ISTOKEN (t = *r) || BITISSET (N, t - ntokens))

                      SETBIT (Vp, t);
                      SETBIT (Vp, t);

-                   }
+                 SETBIT (Pp, i);

                }
                }

-             SETBIT (Pp, i);

            }
            }

+         if (bits_equal (V, Vp, WORDSIZE (nsyms)))
+           break;
+         Vs = Vp;
+         Vp = V;
+         V = Vs;

        }
        }

-      if (bits_equal (V, Vp, WORDSIZE (nsyms)))
-       {
-         break;
-       }
-      Vs = Vp;
-      Vp = V;
-      V = Vs;

     }
     }

-end_iteration:

 
   XFREE (V);
   V = Vp;
 
   XFREE (V);
   V = Vp;


@@ -255,39 +258,46 @@ end_iteration:
 
   /* A token that was used in %prec should not be warned about.  */
   for (i = 1; i < nrules; i++)
 
   /* A token that was used in %prec should not be warned about.  */
   for (i = 1; i < nrules; i++)

-    if (rprecsym[i] != 0)
-      SETBIT (V1, rprecsym[i]);
+    if (rules[i].precsym != 0)
+      SETBIT (V1, rules[i].precsym);

 }
 
 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)
                {

-                 rlhs[np] = rlhs[pn];
-                 rline[np] = rline[pn];
-                 rprec[np] = rprec[pn];
-                 rassoc[np] = rassoc[pn];
-                 rrhs[np] = rrhs[pn];
-                 if (rrhs[np] != ni)
+                 rules[np].lhs   = rules[pn].lhs;
+                 rules[np].line  = rules[pn].line;
+                 rules[np].prec  = rules[pn].prec;
+                 rules[np].assoc = rules[pn].assoc;
+                 rules[np].rhs   = rules[pn].rhs;
+                 if (rules[np].rhs != ni)

                    {
                    {

-                     pi = rrhs[np];
-                     rrhs[np] = ni;
+                     pi = rules[np].rhs;
+                     rules[np].rhs = ni;

                      while (ritem[pi] >= 0)
                        ritem[ni++] = ritem[pi++];
                      ritem[ni++] = -np;
                      while (ritem[pi] >= 0)
                        ritem[ni++] = ritem[pi++];
                      ritem[ni++] = -np;


@@ -295,192 +305,181 @@ 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))
-           {
-             rlhs[pn] = -1;
-           }
-       }
+       rules[pn].useful = BITISSET (P, pn);

     }
     }

+}

 
 

-  /* remove useless symbols */
-  if (nuseless_nonterminals > 0)
-    {

 
 

-      int i, n;
-/*      short  j; JF unused */
-      short *nontermmap;
-      rule r;
+/*------------------------------.
+| Remove useless nonterminals.  |
+`------------------------------*/
+
+static void
+nonterminals_reduce (void)
+{
+  int i, n;

 
 

-      /* 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.  */

 
 

-      nontermmap = XCALLOC (short, nvars) - ntokens;
-      for (i = ntokens; i < nsyms; i++)
-       nontermmap[i] = -1;
+  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++;

 
 

-      n = ntokens;
-      for (i = ntokens; i < nsyms; i++)
-       if (BITISSET (V, i))
-         nontermmap[i] = n++;

 
 

-      /* Shuffle elements of tables indexed by symbol number.  */
+  /* Shuffle elements of tables indexed by symbol number.  */
+  {
+    bucket **symbols_sorted = XMALLOC (bucket *, nvars) - ntokens;

 
 

-      for (i = ntokens; i < nsyms; i++)
-       {
-         n = nontermmap[i];
-         if (n >= 0)
-           {
-             sassoc[n] = sassoc[i];
-             sprec[n] = sprec[i];
-             tags[n] = tags[i];
-           }
-         else
-           {
-             free (tags[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);
+  }

 
 

-      /* Replace all symbol numbers in valid data structures.  */
+  /* Replace all symbol numbers in valid data structures.  */

 
 

-      for (i = 1; i <= nrules; i++)
-       {
-         /* Ignore the rules disabled above.  */
-         if (rlhs[i] >= 0)
-           rlhs[i] = nontermmap[rlhs[i]];
-         if (ISVAR (rprecsym[i]))
-           /* Can this happen?  */
-           rprecsym[i] = nontermmap[rprecsym[i]];
-       }
+  for (i = 1; i <= nrules; i++)
+    {
+      rules[i].lhs = nontermmap[rules[i].lhs];
+      if (ISVAR (rules[i].precsym))
+       /* Can this happen?  */
+       rules[i].precsym = nontermmap[rules[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", symbols[nsyms + i]->tag);
+      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", tags[i]);
+           fprintf (out, "%s\n\n", _("Terminals which are not used:"));
+         b = TRUE;
+         fprintf (out, "   %s\n", symbols[i]->tag);

        }
        }

-    }
+    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))
-           {
-             fprintf (out, "#%-4d  ", i);
-             fprintf (out, "%s :\t", tags[rlhs[i]]);
-             for (r = &ritem[rrhs[i]]; *r >= 0; r++)
-               fprintf (out, " %s", tags[*r]);
-             fprintf (out, ";\n");
-           }
-       }
+       if (!rules[i].useful)
+         {
+           rule r;
+           fprintf (out, "#%-4d  ", i - 1);
+           fprintf (out, "%s:", symbols[rules[i].lhs]->tag);
+           for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
+             fprintf (out, " %s", symbols[*r]->tag);
+           fputs (";\n", out);
+         }
+      fputs ("\n\n", out);

     }
     }

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

 }
 \f
 }
 \f

-#if 0                          /* XXX currently unused.  */

 static void
 dump_grammar (FILE *out)
 {
   int i;
   rule r;
 
 static void
 dump_grammar (FILE *out)
 {
   int i;
   rule r;
 

+  fprintf (out, "REDUCED GRAMMAR\n\n");

   fprintf (out,
   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,
+            symbols[i]->prec, symbols[i]->assoc, symbols[i]->tag);

   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, rprec[i], rassoc[i], rlhs[i], rrhs[i]);
-      for (r = &ritem[rrhs[i]]; *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[rules[i].rhs]; *r >= 0; ++r)
+       ++rhs_count;
+      fprintf (out, "%3d (%2d, %2d, %2d, %2d-%2d)   %2d ->",
+              i - 1,
+              rules[i].prec, rules[i].assoc, rules[i].useful,
+              rules[i].rhs, rules[i].rhs + rhs_count - 1,
+              rules[i].lhs);
+      /* Dumped the RHS. */
+      for (r = &ritem[rules[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++)
     {
   for (i = 1; i <= nrules; i++)
     {

-      fprintf (out, "%-5d  %s :", i, tags[rlhs[i]]);
-      for (r = &ritem[rrhs[i]]; *r > 0; r++)
-       fprintf (out, " %s", tags[*r]);
+      fprintf (out, "%-5d  %s :", i, symbols[rules[i].lhs]->tag);
+      for (r = &ritem[rules[i].rhs]; *r >= 0; r++)
+       fprintf (out, " %s", symbols[*r]->tag);

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

-#endif

 
 
 
 
 
 


@@ -492,24 +491,27 @@ 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);
 }


@@ -538,27 +540,20 @@ reduce_grammar (void)
 
   if (!BITISSET (N, start_symbol - ntokens))
     fatal (_("Start symbol %s does not derive any sentence"),
 
   if (!BITISSET (N, start_symbol - ntokens))
     fatal (_("Start symbol %s does not derive any sentence"),

-          tags[start_symbol]);
+          symbols[start_symbol]->tag);

 
   reduce_grammar_tables ();
 
   reduce_grammar_tables ();

-#if 0
-  if (verbose_flag)
+  if (nuseless_nonterminals > 0)
+    nonterminals_reduce ();
+
+  if (trace_flag)

     {
     {

-      fprintf (out, "REDUCED GRAMMAR\n\n");
-      dump_grammar ();
+      dump_grammar (stderr);
+
+      fprintf (stderr, "reduced %s defines %d terminals, %d nonterminals\
+, and %d productions.\n",
+              infile, ntokens, nvars, nrules);

     }
     }

-#endif
-
-  if (statistics_flag)
-    fprintf (stderr, _("reduced %s defines %d terminal%s, %d nonterminal%s\
-, and %d production%s.\n"),
-            infile,
-            ntokens,
-            (ntokens == 1 ? "" : "s"),
-            nvars,
-            (nvars == 1 ? "" : "s"),
-            nrules,
-            (nrules == 1 ? "" : "s"));

 }
 
 
 }