X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/db8837cbe1210e9df3da80472abee9b9896fd152..60491a948b9339a6f68fafb63b51e9899d4e6aad:/src/reduce.c

diff --git a/src/reduce.c b/src/reduce.c
index ba605df4..35aab2e7 100644
--- a/src/reduce.c
+++ b/src/reduce.c
@@ -37,9 +37,6 @@
 #include "getargs.h"
 #include "bitset.h"
 
-typedef short *rule;
-
-
 /* Set of all nonterminals which are not useless.  */
 static bitset N;
 
@@ -54,7 +51,7 @@ static bitset V;
 static bitset V1;
 
 static int nuseful_productions;
-static int nuseless_productions;
+int nuseless_productions;
 static int nuseful_nonterminals;
 int nuseless_nonterminals;
 
@@ -67,7 +64,7 @@ int nuseless_nonterminals;
 static bool
 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
@@ -139,7 +136,7 @@ inaccessable_symbols (void)
   bitset Vp, Vs, Pp;
   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
@@ -168,9 +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)
 	{
@@ -230,11 +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
@@ -252,7 +257,7 @@ reduce_grammar_tables (void)
     /* Renumber the rules markers in RITEMS.  */
     for (i = 1; i < nrules + 1; ++i)
       {
-	short *rhsp = rules[i].rhs;
+	item_number_t *rhsp = rules[i].rhs;
 	for (/* Nothing. */; *rhsp >= 0; ++rhsp)
 	  /* Nothing. */;
 	*rhsp = -i;
@@ -261,7 +266,7 @@ reduce_grammar_tables (void)
     nrules -= nuseless_productions;
   }
 
-  /* Adjust NRITEMS and NITEMS.  */
+  /* Adjust NRITEMS.  */
   {
     int r;
     int length;
@@ -269,7 +274,6 @@ reduce_grammar_tables (void)
       {
 	length = rule_rhs_length (&rules[r]);
 	nritems -= length + 1;
-	nitems -= length + 1;
       }
   }
 }
@@ -282,19 +286,25 @@ reduce_grammar_tables (void)
 static void
 nonterminals_reduce (void)
 {
-  int i, n;
+  symbol_number_t i, n;
 
   /* 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++)
     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.  */
@@ -310,11 +320,17 @@ nonterminals_reduce (void)
     free (symbols_sorted + ntokens);
   }
 
-  for (i = 0; i < nritems; ++i)
-    if (ISVAR (ritem[i]))
-      ritem[i] = nontermmap[ritem[i]];
-
-  start_symbol = nontermmap[start_symbol];
+  {
+    int r;
+    for (r = 1; r < nrules + 1; ++r)
+      {
+	item_number_t *rhsp;
+	for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)
+	  if (ISVAR (*rhsp))
+	    *rhsp =  symbol_number_as_item_number (nontermmap[*rhsp]);
+      }
+    axiom->number = nontermmap[axiom->number];
+  }
 
   nsyms -= nuseless_nonterminals;
   nvars -= nuseless_nonterminals;
@@ -335,8 +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);
     }
 
@@ -349,84 +364,19 @@ 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);
   }
 
   if (nuseless_productions > 0)
-    {
-      int i;
-      fprintf (out, "%s\n\n", _("Useless rules:"));
-      for (i = nrules + 1; i < nuseless_productions + nrules + 1; i++)
-	{
-	  rule r;
-	  fprintf (out, "#%-4d  ", rules[i].user_number - 1);
-	  fprintf (out, "%s:", quotearg_style (escape_quoting_style,
-					       rules[i].lhs->tag));
-	  for (r = rules[i].rhs; *r >= 0; r++)
-	    fprintf (out, " %s", quotearg_style (escape_quoting_style,
-						 symbols[*r]->tag));
-	  fputs (";\n", out);
-	}
-      fputs ("\n\n", out);
-    }
+    grammar_rules_partial_print (out, _("Useless rules"),
+				 nrules + 1,
+				 nuseless_productions + nrules + 1);
 }
 
-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,
-	     symbols[i]->prec, symbols[i]->assoc,
-	     quotearg_style (escape_quoting_style, symbols[i]->tag));
-  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 + nuseless_productions + 1; i++)
-    {
-      int rhs_count = 0;
-      /* Find the last RHS index in ritems. */
-      for (r = rules[i].rhs; *r >= 0; ++r)
-	++rhs_count;
-      fprintf (out, "%3d (%2d, %2d, %2d, %2d-%2d)   %2d ->",
-	       i - 1,
-	       rules[i].prec->prec,
-	       rules[i].prec->assoc,
-	       rules[i].useful,
-	       rules[i].rhs - ritem,
-	       rules[i].rhs - ritem + rhs_count - 1,
-	       rules[i].lhs->number);
-      /* Dumped the RHS. */
-      for (r = rules[i].rhs; *r >= 0; r++)
-	fprintf (out, "%3d", *r);
-      fprintf (out, "  [%d]\n", -(*r) - 1);
-    }
-  fprintf (out, "\n\n");
-  fprintf (out, "Rules interpreted\n-----------------\n\n");
-  for (i = 1; i < nrules + nuseless_productions + 1; i++)
-    {
-      fprintf (out, "%-5d  %s :",
-	       i, quotearg_style (escape_quoting_style, rules[i].lhs->tag));
-      for (r = rules[i].rhs; *r >= 0; r++)
-	fprintf (out, " %s",
-		 quotearg_style (escape_quoting_style, symbols[*r]->tag));
-      fputc ('\n', out);
-    }
-  fprintf (out, "\n\n");
-}
+
 
 
 
@@ -443,7 +393,7 @@ 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",
@@ -484,18 +434,21 @@ 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]));
 
-  if (nuseless_productions > 0)
-    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_productions > 0)
+    reduce_grammar_tables ();
 
   if (trace_flag)
     {
-      dump_grammar (stderr);
+      grammar_dump (stderr, "Reduced Grammar");
 
       fprintf (stderr, "reduced %s defines %d terminals, %d nonterminals\
 , and %d productions.\n",