Stop storing rules from 1 to nrules + 1.

[bison.git] / src / nullable.c

diff --git a/src/nullable.c b/src/nullable.c
index abeefdde6121c46701fcb9e55f6f20412dad1560..6a70fa572be96a66dd3aa90c4b8dc6374234408f 100644 (file)
--- a/src/nullable.c
+++ b/src/nullable.c
@@ -1,5 +1,5 @@
 /* Part of the bison parser generator,
-   Copyright 1984, 1989, 2000, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989, 2000, 2001, 2002 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -26,11 +26,17 @@
 #include "system.h"
 #include "getargs.h"
 #include "symtab.h"
-#include "types.h"
 #include "gram.h"
 #include "reduce.h"
 #include "nullable.h"
 
+/* Linked list of rule numbers.  */
+typedef struct rule_list_s
+{
+  struct rule_list_s *next;
+  rule_number_t value;
+} rule_list_t;
+
 char *nullable = NULL;
 
 static void
@@ -46,19 +52,19 @@ nullable_print (FILE *out)
 void
 set_nullable (void)
 {
-  int ruleno;
-  short *s1;
-  short *s2;
-  shorts *p;
+  rule_number_t ruleno;
+  symbol_number_t *s1;
+  symbol_number_t *s2;
+  rule_list_t *p;
 
-  short *squeue = XCALLOC (short, nvars);
-  short *rcount = XCALLOC (short, nrules + 1);
+  symbol_number_t *squeue = XCALLOC (symbol_number_t, nvars);
+  short *rcount = XCALLOC (short, nrules);
   /* RITEM contains all the rules, including useless productions.
      Hence we must allocate room for useless nonterminals too.  */
-  shorts **rsets = XCALLOC (shorts *, nvars) - ntokens;
+  rule_list_t **rsets = XCALLOC (rule_list_t *, nvars) - ntokens;
   /* This is said to be more elements than we actually use.
      Supposedly NRITEMS - NRULES is enough.  But why take the risk?  */
-  shorts *relts = XCALLOC (shorts, nritems + nvars + 1);
+  rule_list_t *relts = XCALLOC (rule_list_t, nritems + nvars + 1);
 
   if (trace_flag)
     fprintf (stderr, "Entering set_nullable\n");
@@ -68,22 +74,23 @@ set_nullable (void)
   s1 = s2 = squeue;
   p = relts;
 
-  for (ruleno = 1; ruleno < nrules + 1; ++ruleno)
+  for (ruleno = 0; ruleno < nrules; ++ruleno)
     if (rules[ruleno].useful)
       {
-       if (rules[ruleno].rhs[0] >= 0)
+       rule_t *rule = &rules[ruleno];
+       if (rule->rhs[0] >= 0)
          {
            /* This rule has a non empty RHS. */
-           short *r;
+           item_number_t *r = NULL;
            int any_tokens = 0;
-           for (r = rules[ruleno].rhs; *r >= 0; ++r)
+           for (r = rule->rhs; *r >= 0; ++r)
              if (ISTOKEN (*r))
                any_tokens = 1;
 
            /* This rule has only nonterminals: schedule it for the second
               pass.  */
            if (!any_tokens)
-             for (r = rules[ruleno].rhs; *r >= 0; ++r)
+             for (r = rule->rhs; *r >= 0; ++r)
                {
                  rcount[ruleno]++;
                  p->next = rsets[*r];
@@ -95,11 +102,11 @@ set_nullable (void)
        else
          {
            /* This rule has an empty RHS. */
-           assert (rules[ruleno].rhs[0] == -ruleno);
-           if (rules[ruleno].useful && !nullable[rules[ruleno].lhs])
+           assert (item_number_as_rule_number (rule->rhs[0]) == ruleno);
+           if (rule->useful && !nullable[rule->lhs->number])
              {
-               nullable[rules[ruleno].lhs] = 1;
-               *s2++ = rules[ruleno].lhs;
+               nullable[rule->lhs->number] = 1;
+               *s2++ = rule->lhs->number;
              }
          }
       }
@@ -109,10 +116,10 @@ set_nullable (void)
       {
        ruleno = p->value;
        if (--rcount[ruleno] == 0)
-         if (rules[ruleno].useful && !nullable[rules[ruleno].lhs])
+         if (rules[ruleno].useful && !nullable[rules[ruleno].lhs->number])
            {
-             nullable[rules[ruleno].lhs] = 1;
-             *s2++ = rules[ruleno].lhs;
+             nullable[rules[ruleno].lhs->number] = 1;
+             *s2++ = rules[ruleno].lhs->number;
            }
       }