X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/c3b407f430a6c4bab6f0ef5160bb0c34290f3abb..e91ff6ce3d2653b41265591dafd4bdb32ae114c2:/src/reduce.c

diff --git a/src/reduce.c b/src/reduce.c
index b7a7f456..61ad2b2e 100644
--- a/src/reduce.c
+++ b/src/reduce.c
@@ -1,5 +1,5 @@
 /* Grammar reduction for Bison.
-   Copyright 1988, 1989, 2000, 2001  Free Software Foundation, Inc.
+   Copyright (C) 1988, 1989, 2000, 2001, 2002  Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -26,6 +26,7 @@
    user's parser.  */
 
 #include "system.h"
+#include "quotearg.h"
 #include "getargs.h"
 #include "files.h"
 #include "symtab.h"
@@ -36,9 +37,6 @@
 #include "getargs.h"
 #include "bitset.h"
 
-typedef short *rule;
-
-
 /* Set of all nonterminals which are not useless.  */
 static bitset N;
 
@@ -53,7 +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;
 
@@ -66,7 +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
@@ -118,7 +116,7 @@ useless_nonterminals (void)
 	if (!bitset_test (P, i)
 	    && useful_production (i, N))
 	  {
-	    bitset_set (Np, rules[i].lhs - ntokens);
+	    bitset_set (Np, rules[i].lhs->number - ntokens);
 	    bitset_set (P, i);
 	  }
       if (bitset_equal_p (N, Np))
@@ -138,7 +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
@@ -178,7 +176,7 @@ inaccessable_symbols (void)
 	    {
 	      if (!bitset_test (Pp, i)
 		  && bitset_test (P, i)
-		  && bitset_test (V, rules[i].lhs))
+		  && bitset_test (V, rules[i].lhs->number))
 		{
 		  for (r = rules[i].rhs; *r >= 0; r++)
 		    if (ISTOKEN (t = *r) || bitset_test (N, t - ntokens))
@@ -198,9 +196,9 @@ inaccessable_symbols (void)
   V = Vp;
 
   /* Tokens 0, 1, and 2 are internal to Bison.  Consider them useful. */
-  bitset_set (V, 0);		/* end-of-input token */
-  bitset_set (V, 1);		/* error token */
-  bitset_set (V, 2);		/* some undefined token */
+  bitset_set (V, eoftoken->number);		/* end-of-input token */
+  bitset_set (V, errtoken->number);		/* error token */
+  bitset_set (V, undeftoken->number);		/* some undefined token */
 
   bitset_free (P);
   P = Pp;
@@ -217,7 +215,7 @@ inaccessable_symbols (void)
   /* A token that was used in %prec should not be warned about.  */
   for (i = 1; i < nrules + 1; i++)
     if (rules[i].precsym != 0)
-      bitset_set (V1, rules[i].precsym);
+      bitset_set (V1, rules[i].precsym->number);
 }
 
 
@@ -248,22 +246,15 @@ reduce_grammar_tables (void)
     free (rules + 1);
     rules = rules_sorted;
 
-    /* Also reorder ritems. */
-    {
-      short *ritems_sorted = XCALLOC (short, nitems + 1);
-      short *ritemsp = ritems_sorted;
-      for (i = 1; i < nrules + 1; ++i)
-	{
-	  short *rhsp = rules[i].rhs;
-	  rules[i].rhs = ritemsp;
-	  for (/* Nothing. */; *rhsp >= 0; ++rhsp)
-	    *ritemsp++ = *rhsp;
-	  *ritemsp++ = -i;
-	}
-      *ritemsp++ = 0;
-      free (ritem);
-      ritem = ritems_sorted;
-    }
+    /* Renumber the rules markers in RITEMS.  */
+    for (i = 1; i < nrules + 1; ++i)
+      {
+	item_number_t *rhsp = rules[i].rhs;
+	for (/* Nothing. */; *rhsp >= 0; ++rhsp)
+	  /* Nothing. */;
+	*rhsp = -i;
+	rules[i].number = i;
+      }
     nrules -= nuseless_productions;
   }
 
@@ -275,7 +266,6 @@ reduce_grammar_tables (void)
       {
 	length = rule_rhs_length (&rules[r]);
 	nritems -= length + 1;
-	nitems -= length + 1;
       }
   }
 }
@@ -288,12 +278,12 @@ reduce_grammar_tables (void)
 static void
 nonterminals_reduce (void)
 {
-  int i, n;
+  token_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;
+  token_number_t *nontermmap = XCALLOC (token_number_t, nvars) - ntokens;
   n = ntokens;
   for (i = ntokens; i < nsyms; i++)
     if (bitset_test (V, i))
@@ -305,8 +295,10 @@ nonterminals_reduce (void)
 
   /* Shuffle elements of tables indexed by symbol number.  */
   {
-    bucket **symbols_sorted = XMALLOC (bucket *, nvars) - ntokens;
+    symbol_t **symbols_sorted = XMALLOC (symbol_t *, nvars) - ntokens;
 
+    for (i = ntokens; i < nsyms; i++)
+      symbols[i]->number = nontermmap[i];
     for (i = ntokens; i < nsyms; i++)
       symbols_sorted[nontermmap[i]] = symbols[i];
     for (i = ntokens; i < nsyms; i++)
@@ -314,19 +306,9 @@ nonterminals_reduce (void)
     free (symbols_sorted + ntokens);
   }
 
-  /* Replace all symbol numbers in valid data structures.  */
-
-  for (i = 1; i < nrules + 1; i++)
-    {
-      rules[i].lhs = nontermmap[rules[i].lhs];
-      if (ISVAR (rules[i].precsym))
-	/* Can this happen?  */
-	rules[i].precsym = nontermmap[rules[i].precsym];
-    }
-
   for (i = 0; i < nritems; ++i)
     if (ISVAR (ritem[i]))
-      ritem[i] = nontermmap[ritem[i]];
+      ritem[i] = token_number_as_item_number (nontermmap[ritem[i]]);
 
   start_symbol = nontermmap[start_symbol];
 
@@ -349,7 +331,8 @@ reduce_output (FILE *out)
       int i;
       fprintf (out, "%s\n\n", _("Useless nonterminals:"));
       for (i = 0; i < nuseless_nonterminals; ++i)
-	fprintf (out, "   %s\n", symbols[nsyms + i]->tag);
+	fprintf (out, "   %s\n", quotearg_style (escape_quoting_style,
+						 symbols[nsyms + i]->tag));
       fputs ("\n\n", out);
     }
 
@@ -362,7 +345,8 @@ reduce_output (FILE *out)
 	  if (!b)
 	    fprintf (out, "%s\n\n", _("Terminals which are not used:"));
 	  b = TRUE;
-	  fprintf (out, "   %s\n", symbols[i]->tag);
+	  fprintf (out, "   %s\n", quotearg_style (escape_quoting_style,
+						   symbols[i]->tag));
 	}
     if (b)
       fputs ("\n\n", out);
@@ -374,63 +358,20 @@ reduce_output (FILE *out)
       fprintf (out, "%s\n\n", _("Useless rules:"));
       for (i = nrules + 1; i < nuseless_productions + nrules + 1; i++)
 	{
-	  rule r;
-	  fprintf (out, "#%-4d  ", rules[i].number - 1);
-	  fprintf (out, "%s:", symbols[rules[i].lhs]->tag);
+	  item_number_t *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", symbols[*r]->tag);
+	    fprintf (out, " %s", quotearg_style (escape_quoting_style,
+						 symbols[*r]->tag));
 	  fputs (";\n", out);
 	}
       fputs ("\n\n", out);
     }
 }
 
-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, 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, rules[i].assoc, rules[i].useful,
-	       rules[i].rhs - ritem, rules[i].rhs - ritem + rhs_count - 1,
-	       rules[i].lhs);
-      /* 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, symbols[rules[i].lhs]->tag);
-      for (r = rules[i].rhs; *r >= 0; r++)
-	fprintf (out, " %s", symbols[*r]->tag);
-      fputc ('\n', out);
-    }
-  fprintf (out, "\n\n");
-}
+
 
 
 
@@ -490,16 +431,19 @@ reduce_grammar (void)
 
   if (!bitset_test (N, start_symbol - ntokens))
     fatal (_("Start symbol %s does not derive any sentence"),
-	   symbols[start_symbol]->tag);
+	   quotearg_style (escape_quoting_style, symbols[start_symbol]->tag));
 
-  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",