Copy BYacc's nice way to report the grammar.

[bison.git] / src / reduce.c

diff --git a/src/reduce.c b/src/reduce.c
index fd6f9e15c1921b6fa2ffabf6da7d1f9bdbafbbf0..2319b60bf192104f672ff22b0617b62015217824 100644 (file)
--- a/src/reduce.c
+++ b/src/reduce.c
@@ -165,9 +165,9 @@ inaccessable_symbols (void)
   Pp = bitset_create (nrules + 1, BITSET_FIXED);
 
   /* If the start symbol isn't useful, then nothing will be useful. */
-  if (bitset_test (N, start_symbol - ntokens))
+  if (bitset_test (N, axiom->number - ntokens))
     {
-      bitset_set (V, start_symbol);
+      bitset_set (V, axiom->number);
 
       while (1)
        {
@@ -227,11 +227,19 @@ inaccessable_symbols (void)
 static void
 reduce_grammar_tables (void)
 {
-  /* Flag useless productions.  */
+  /* Report and flag useless productions.  */
   {
-    int pn;
-    for (pn = 1; pn < nrules + 1; pn++)
-      rules[pn].useful = bitset_test (P, pn);
+    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);
+         }
+      }
   }
 
   /* Map the nonterminals to their new index: useful first, useless
@@ -278,19 +286,25 @@ reduce_grammar_tables (void)
 static void
 nonterminals_reduce (void)
 {
-  token_number_t i, n;
+  symbol_number_t i, n;
 
   /* Map the nonterminals to their new index: useful first, useless
      afterwards.  Kept for later report.  */
 
-  token_number_t *nontermmap = XCALLOC (token_number_t, nvars) - ntokens;
+  symbol_number_t *nontermmap = XCALLOC (symbol_number_t, nvars) - ntokens;
   n = ntokens;
   for (i = ntokens; i < nsyms; i++)
     if (bitset_test (V, i))
       nontermmap[i] = n++;
   for (i = ntokens; i < nsyms; i++)
     if (!bitset_test (V, i))
-      nontermmap[i] = n++;
+      {
+       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.  */
@@ -313,9 +327,9 @@ nonterminals_reduce (void)
        item_number_t *rhsp;
        for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)
          if (ISVAR (*rhsp))
-           *rhsp =  token_number_as_item_number (nontermmap[*rhsp]);
+           *rhsp =  symbol_number_as_item_number (nontermmap[*rhsp]);
       }
-    start_symbol = nontermmap[start_symbol];
+    axiom->number = nontermmap[axiom->number];
   }
 
   nsyms -= nuseless_nonterminals;
@@ -337,8 +351,7 @@ reduce_output (FILE *out)
       int i;
       fprintf (out, "%s\n\n", _("Useless nonterminals:"));
       for (i = 0; i < nuseless_nonterminals; ++i)
-       fprintf (out, "   %s\n", quotearg_style (escape_quoting_style,
-                                                symbols[nsyms + i]->tag));
+       fprintf (out, "   %s\n", symbol_tag_get (symbols[nsyms + i]));
       fputs ("\n\n", out);
     }
 
@@ -351,8 +364,7 @@ reduce_output (FILE *out)
          if (!b)
            fprintf (out, "%s\n\n", _("Terminals which are not used:"));
          b = TRUE;
-         fprintf (out, "   %s\n", quotearg_style (escape_quoting_style,
-                                                  symbols[i]->tag));
+         fprintf (out, "   %s\n", symbol_tag_get (symbols[i]));
        }
     if (b)
       fputs ("\n\n", out);
@@ -366,11 +378,9 @@ reduce_output (FILE *out)
        {
          item_number_t *r;
          fprintf (out, "#%-4d  ", rules[i].user_number - 1);
-         fprintf (out, "%s:", quotearg_style (escape_quoting_style,
-                                              rules[i].lhs->tag));
+         fprintf (out, "%s:", symbol_tag_get (rules[i].lhs));
          for (r = rules[i].rhs; *r >= 0; r++)
-           fprintf (out, " %s", quotearg_style (escape_quoting_style,
-                                                symbols[*r]->tag));
+           fprintf (out, " %s", symbol_tag_get (symbols[*r]));
          fputs (";\n", out);
        }
       fputs ("\n\n", out);
@@ -394,7 +404,7 @@ reduce_print (void)
                               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",
@@ -435,9 +445,9 @@ reduce_grammar (void)
 
   reduce_print ();
 
-  if (!bitset_test (N, start_symbol - ntokens))
+  if (!bitset_test (N, axiom->number - ntokens))
     fatal (_("Start symbol %s does not derive any sentence"),
-          quotearg_style (escape_quoting_style, symbols[start_symbol]->tag));
+          symbol_tag_get (symbols[axiom->number]));
 
   /* First reduce the nonterminals, as they renumber themselves in the
      whole grammar.  If you change the order, nonterms would be