From: Akim Demaille <akim@epita.fr>
Date: Wed, 5 Dec 2001 09:27:35 +0000 (+0000)
Subject: * src/nullable.c (set_nullable): Use a for loop to de-obfuscate
X-Git-Tag: before-m4-back-end~213
X-Git-Url: https://git.saurik.com/bison.git/commitdiff_plain/e3e4e81446edb4e92e21cde1fc873f517b9402ea

* src/nullable.c (set_nullable): Use a for loop to de-obfuscate
the handling of squeue.
`symbol >= 0' is wrong now, use `rule_table[ruleno].useful'.
---

diff --git a/ChangeLog b/ChangeLog
index d08aba9f..f59d0292 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2001-12-05  Akim Demaille  <akim@epita.fr>
+
+	* src/nullable.c (set_nullable): Use a for loop to de-obfuscate
+	the handling of squeue.
+	`symbol >= 0' is wrong now, use `rule_table[ruleno].useful'.
+
+	
 2001-12-05  Akim Demaille  <akim@epita.fr>
 
 	Because useless nonterminals are now kept alive (instead of being
diff --git a/src/nullable.c b/src/nullable.c
index 2797180c..8e8809e2 100644
--- a/src/nullable.c
+++ b/src/nullable.c
@@ -107,23 +107,16 @@ set_nullable (void)
     }
 
   while (s1 < s2)
-    {
-      p = rsets[*s1++];
-      while (p)
-	{
-	  int ruleno = p->value;
-	  p = p->next;
-	  if (--rcount[ruleno] == 0)
+    for (p = rsets[*s1++]; p; p = p->next)
+      {
+	int ruleno = p->value;
+	if (--rcount[ruleno] == 0)
+	  if (rule_table[ruleno].useful && !nullable[rule_table[ruleno].lhs])
 	    {
-	      int symbol = rule_table[ruleno].lhs;
-	      if (symbol >= 0 && !nullable[symbol])
-		{
-		  nullable[symbol] = 1;
-		  *s2++ = symbol;
-		}
+	      nullable[rule_table[ruleno].lhs] = 1;
+	      *s2++ = rule_table[ruleno].lhs;
 	    }
-	}
-    }
+      }
 
   XFREE (squeue);
   XFREE (rcount);