X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/95612cfa608188fc323ed3f8560cc6aea953ff32..0f664b89d4aa86146015acd87a770db878d7e5d4:/src/reduce.c?ds=inline

diff --git a/src/reduce.c b/src/reduce.c
index 699f45a4..1306374a 100644
--- a/src/reduce.c
+++ b/src/reduce.c
@@ -1,22 +1,22 @@
 /* Grammar reduction for Bison.
-   Copyright (C) 1988, 1989, 2000, 2001, 2002  Free Software Foundation, Inc.
+
+   Copyright (C) 1988, 1989, 2000, 2001, 2002, 2003, 2005, 2006,
+   2007 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
-   Bison is free software; you can redistribute it and/or modify
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
 
-   Bison is distributed in the hope that it will be useful,
+   This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with Bison; see the file COPYING.  If not, write to
-   the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-   Boston, MA 02111-1307, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 
 /* Reduce the grammar: Find and eliminate unreachable terminals,
@@ -25,17 +25,20 @@
 /* Don't eliminate unreachable terminals: They may be used by the
    user's parser.  */
 
+#include <config.h>
 #include "system.h"
-#include "quotearg.h"
-#include "getargs.h"
+
+#include <bitset.h>
+#include <quotearg.h>
+
+#include "complain.h"
 #include "files.h"
-#include "symtab.h"
+#include "getargs.h"
 #include "gram.h"
-#include "complain.h"
-#include "reduce.h"
+#include "print-xml.h"
 #include "reader.h"
-#include "getargs.h"
-#include "bitset.h"
+#include "reduce.h"
+#include "symtab.h"
 
 /* Set of all nonterminals which are not useless.  */
 static bitset N;
@@ -50,10 +53,10 @@ static bitset V;
    `useless', but no warning should be issued).  */
 static bitset V1;
 
-static rule_number_t nuseful_productions;
-rule_number_t nuseless_productions;
+static rule_number nuseful_productions;
+rule_number nuseless_productions;
 static int nuseful_nonterminals;
-symbol_number_t nuseless_nonterminals;
+symbol_number nuseless_nonterminals;
 
 /*-------------------------------------------------------------------.
 | Another way to do this would be with a set for each production and |
@@ -62,9 +65,9 @@ symbol_number_t nuseless_nonterminals;
 `-------------------------------------------------------------------*/
 
 static bool
-useful_production (rule_number_t r, bitset N0)
+useful_production (rule_number r, bitset N0)
 {
-  item_number_t *rhsp;
+  item_number *rhsp;
 
   /* A production is useful if all of the nonterminals in its appear
      in the set of useful nonterminals.  */
@@ -84,7 +87,7 @@ static void
 useless_nonterminals (void)
 {
   bitset Np, Ns;
-  rule_number_t r;
+  rule_number r;
 
   /* N is set as built.  Np is set being built this iteration. P is
      set of all productions which have a RHS all in N.  */
@@ -167,7 +170,7 @@ inaccessable_symbols (void)
 
       while (1)
 	{
-	  rule_number_t r;
+	  rule_number r;
 	  bitset_copy (Vp, V);
 	  for (r = 0; r < nrules; r++)
 	    {
@@ -175,7 +178,7 @@ inaccessable_symbols (void)
 		  && bitset_test (P, r)
 		  && bitset_test (V, rules[r].lhs->number))
 		{
-		  item_number_t *rhsp;
+		  item_number *rhsp;
 		  for (rhsp = rules[r].rhs; *rhsp >= 0; rhsp++)
 		    if (ISTOKEN (*rhsp) || bitset_test (N, *rhsp - ntokens))
 		      bitset_set (Vp, *rhsp);
@@ -206,7 +209,7 @@ inaccessable_symbols (void)
 
   nuseful_nonterminals = 0;
   {
-    symbol_number_t i;
+    symbol_number i;
     for (i = ntokens; i < nsyms; i++)
       if (bitset_test (V, i))
 	nuseful_nonterminals++;
@@ -215,7 +218,7 @@ inaccessable_symbols (void)
 
   /* A token that was used in %prec should not be warned about.  */
   {
-    rule_number_t r;
+    rule_number r;
     for (r = 0; r < nrules; ++r)
       if (rules[r].precsym != 0)
 	bitset_set (V1, rules[r].precsym->number);
@@ -233,10 +236,10 @@ reduce_grammar_tables (void)
 {
   /* Report and flag useless productions.  */
   {
-    rule_number_t r;
+    rule_number r;
     for (r = 0; r < nrules; r++)
       rules[r].useful = bitset_test (P, r);
-    grammar_rules_never_reduced_report (_("useless rule"));
+    grammar_rules_useless_report (_("rule useless in grammar"));
   }
 
   /* Map the nonterminals to their new index: useful first, useless
@@ -244,8 +247,8 @@ reduce_grammar_tables (void)
   {
     int useful = 0;
     int useless = nrules - nuseless_productions;
-    rule_t *rules_sorted = XMALLOC (rule_t, nrules);
-    rule_number_t r;
+    rule *rules_sorted = xnmalloc (nrules, sizeof *rules_sorted);
+    rule_number r;
     for (r = 0; r < nrules; ++r)
       rules_sorted[rules[r].useful ? useful++ : useless++] = rules[r];
     free (rules);
@@ -254,7 +257,7 @@ reduce_grammar_tables (void)
     /* Renumber the rules markers in RITEMS.  */
     for (r = 0; r < nrules; ++r)
       {
-	item_number_t *rhsp = rules[r].rhs;
+	item_number *rhsp = rules[r].rhs;
 	for (/* Nothing. */; *rhsp >= 0; ++rhsp)
 	  /* Nothing. */;
 	*rhsp = rule_number_as_item_number (r);
@@ -265,7 +268,7 @@ reduce_grammar_tables (void)
 
   /* Adjust NRITEMS.  */
   {
-    int r;
+    rule_number r;
     int length;
     for (r = nrules; r < nrules + nuseless_productions; ++r)
       {
@@ -283,56 +286,55 @@ reduce_grammar_tables (void)
 static void
 nonterminals_reduce (void)
 {
-  symbol_number_t i, n;
+  symbol_number i, n;
 
   /* Map the nonterminals to their new index: useful first, useless
      afterwards.  Kept for later report.  */
 
-  symbol_number_t *nontermmap = XCALLOC (symbol_number_t, nvars) - ntokens;
+  symbol_number *nontermmap = xnmalloc (nvars, sizeof *nontermmap);
   n = ntokens;
   for (i = ntokens; i < nsyms; i++)
     if (bitset_test (V, i))
-      nontermmap[i] = n++;
+      nontermmap[i - ntokens] = n++;
   for (i = ntokens; i < nsyms; i++)
     if (!bitset_test (V, i))
       {
-	nontermmap[i] = n++;
-	LOCATION_PRINT (stderr, symbols[i]->location);
-	fprintf (stderr, ": %s: %s: %s\n",
-		 _("warning"), _("useless nonterminal"),
+	nontermmap[i - ntokens] = n++;
+	warn_at (symbols[i]->location, _("nonterminal useless in grammar: %s"),
 		 symbols[i]->tag);
       }
 
 
   /* Shuffle elements of tables indexed by symbol number.  */
   {
-    symbol_t **symbols_sorted = XMALLOC (symbol_t *, nvars) - ntokens;
+    symbol **symbols_sorted = xnmalloc (nvars, sizeof *symbols_sorted);
 
     for (i = ntokens; i < nsyms; i++)
-      symbols[i]->number = nontermmap[i];
+      symbols[i]->number = nontermmap[i - ntokens];
     for (i = ntokens; i < nsyms; i++)
-      symbols_sorted[nontermmap[i]] = symbols[i];
+      symbols_sorted[nontermmap[i - ntokens] - ntokens] = symbols[i];
     for (i = ntokens; i < nsyms; i++)
-      symbols[i] = symbols_sorted[i];
-    free (symbols_sorted + ntokens);
+      symbols[i] = symbols_sorted[i - ntokens];
+    free (symbols_sorted);
   }
 
   {
-    rule_number_t r;
+    rule_number r;
     for (r = 0; r < nrules; ++r)
       {
-	item_number_t *rhsp;
+	item_number *rhsp;
 	for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)
 	  if (ISVAR (*rhsp))
-	    *rhsp =  symbol_number_as_item_number (nontermmap[*rhsp]);
+	    *rhsp =  symbol_number_as_item_number (nontermmap[*rhsp
+							      - ntokens]);
       }
-    accept->number = nontermmap[accept->number];
+    accept->number = nontermmap[accept->number - ntokens];
   }
 
   nsyms -= nuseless_nonterminals;
   nvars -= nuseless_nonterminals;
 
-  free (nontermmap + ntokens);
+  free (nontermmap);
 }
 
 
@@ -346,7 +348,7 @@ reduce_output (FILE *out)
   if (nuseless_nonterminals > 0)
     {
       int i;
-      fprintf (out, "%s\n\n", _("Useless nonterminals"));
+      fprintf (out, "%s\n\n", _("Nonterminals useless in grammar"));
       for (i = 0; i < nuseless_nonterminals; ++i)
 	fprintf (out, "   %s\n", symbols[nsyms + i]->tag);
       fputs ("\n\n", out);
@@ -356,10 +358,10 @@ reduce_output (FILE *out)
     bool b = false;
     int i;
     for (i = 0; i < ntokens; i++)
-      if (!bitset_test (V, i) && !bitset_test (V1, i))
+      if (reduce_token_unused_in_grammar (i))
 	{
 	  if (!b)
-	    fprintf (out, "%s\n\n", _("Terminals which are not used"));
+	    fprintf (out, "%s\n\n", _("Terminals unused in grammar"));
 	  b = true;
 	  fprintf (out, "   %s\n", symbols[i]->tag);
 	}
@@ -368,14 +370,11 @@ reduce_output (FILE *out)
   }
 
   if (nuseless_productions > 0)
-    grammar_rules_partial_print (out, _("Useless rules"),
-				 rule_useless_p);
+    grammar_rules_partial_print (out, _("Rules useless in grammar"),
+				 rule_useless_in_grammar_p);
 }
 
 
-
-
-
 /*-------------------------------.
 | Report the results to STDERR.  |
 `-------------------------------*/
@@ -383,17 +382,11 @@ reduce_output (FILE *out)
 static void
 reduce_print (void)
 {
-  if (yacc_flag && nuseless_productions)
-    fprintf (stderr, ngettext ("%d rule never reduced\n",
-			       "%d rules never reduced\n",
-			       nuseless_productions),
-	     nuseless_productions);
-
   fprintf (stderr, "%s: %s: ", grammar_file, _("warning"));
 
   if (nuseless_nonterminals > 0)
-    fprintf (stderr, ngettext ("%d useless nonterminal",
-			       "%d useless nonterminals",
+    fprintf (stderr, ngettext ("%d nonterminal",
+			       "%d nonterminals",
 			       nuseless_nonterminals),
 	     nuseless_nonterminals);
 
@@ -401,12 +394,14 @@ reduce_print (void)
     fprintf (stderr, _(" and "));
 
   if (nuseless_productions > 0)
-    fprintf (stderr, ngettext ("%d useless rule",
-			       "%d useless rules",
+    fprintf (stderr, ngettext ("%d rule",
+			       "%d rules",
 			       nuseless_productions),
 	     nuseless_productions);
+
+  if (nuseless_nonterminals > 0 || nuseless_productions > 0)
+    fprintf (stderr, _(" useless in grammar"));
   fprintf (stderr, "\n");
-  fflush (stderr);
 }
 
 void
@@ -424,7 +419,7 @@ reduce_grammar (void)
   useless_nonterminals ();
   inaccessable_symbols ();
 
-  reduced = (bool) (nuseless_nonterminals + nuseless_productions > 0);
+  reduced = (nuseless_nonterminals + nuseless_productions > 0);
   if (!reduced)
     return;
 
@@ -453,6 +448,19 @@ reduce_grammar (void)
     }
 }
 
+bool
+reduce_token_unused_in_grammar (symbol_number i)
+{
+  aver (i < ntokens);
+  return !bitset_test (V, i) && !bitset_test (V1, i);
+}
+
+bool
+reduce_nonterminal_useless_in_grammar (symbol_number i)
+{
+  aver (ntokens <= i && i < nsyms + nuseless_nonterminals);
+  return nsyms <= i;
+}
 
 /*-----------------------------------------------------------.
 | Free the global sets used to compute the reduced grammar.  |