From f6d0f937fd3bdb0242285438eae43e06ae25a5f6 Mon Sep 17 00:00:00 2001
From: Akim Demaille <akim@epita.fr>
Date: Tue, 11 Jun 2002 08:07:36 +0000
Subject: [PATCH 1/1] * src/reader.c (grammar_end, grammar_symbol_append): New.
 (readgram): Use them. Make the use of `p' as local as possible.

---
 ChangeLog    |  6 +++++
 src/reader.c | 67 +++++++++++++++++++++++++++-------------------------
 2 files changed, 41 insertions(+), 32 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 02a5ac60..7fb5fcdc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2002-06-11  Akim Demaille  <akim@epita.fr>
+
+	* src/reader.c (grammar_end, grammar_symbol_append): New.
+	(readgram): Use them.
+	Make the use of `p' as local as possible.
+
 2002-06-10  Akim Demaille  <akim@epita.fr>
 
 	GCJ's parser requires the tokens to be defined before the prologue.
diff --git a/src/reader.c b/src/reader.c
index f2bc42e7..d1a6b9aa 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -1072,13 +1072,28 @@ gensym (void)
 | in the rules section.                                              |
 `-------------------------------------------------------------------*/
 
+/* The (currently) last symbol of GRAMMAR. */
+symbol_list *grammar_end = NULL;
+
+/* Append S to the GRAMMAR. */
+static void
+grammar_symbol_append (symbol_t *s)
+{
+  symbol_list *p = symbol_list_new (s);
+
+  if (grammar_end)
+    grammar_end->next = p;
+  else
+    grammar = p;
+
+  grammar_end = p;
+}
+
 static void
 readgram (void)
 {
   token_t t;
   symbol_t *lhs = NULL;
-  symbol_list *p = NULL;
-  symbol_list *p1 = NULL;
 
   /* Points to first symbol_list of current rule. its symbol is the
      lhs of the rule.  */
@@ -1125,16 +1140,9 @@ readgram (void)
 	++nrules;
 	++nritems;
 
-	p = symbol_list_new (lhs);
-
-	crule1 = p1;
-	if (p1)
-	  p1->next = p;
-	else
-	  grammar = p;
-
-	p1 = p;
-	crule = p;
+	crule1 = grammar_end;
+	grammar_symbol_append (lhs);
+	crule = grammar_end;
 
 	/* mark the rule's lhs as a nonterminal if not already so.  */
 
@@ -1196,13 +1204,13 @@ readgram (void)
 
 		/* Make a dummy nonterminal, a gensym.  */
 		symbol_t *sdummy = gensym ();
+		symbol_list *p = symbol_list_new (sdummy);
 
 		/* Make a new rule, whose body is empty, before the
 		   current one, so that the action just read can
 		   belong to it.  */
 		++nrules;
 		++nritems;
-		p = symbol_list_new (sdummy);
 		/* Attach its lineno to that of the host rule. */
 		p->line = crule->line;
 		/* Move the action from the host rule to this one. */
@@ -1223,19 +1231,14 @@ readgram (void)
 		/* Insert the dummy generated by that rule into this
 		   rule.  */
 		++nritems;
-		p = symbol_list_new (sdummy);
-		p1->next = p;
-		p1 = p;
-
+		grammar_symbol_append (sdummy);
 		action_flag = 0;
 	      }
 
 	    if (t == tok_identifier)
 	      {
 		++nritems;
-		p = symbol_list_new (symval);
-		p1->next = p;
-		p1 = p;
+		grammar_symbol_append (symval);
 	      }
 	    else		/* handle an action.  */
 	      {
@@ -1247,9 +1250,7 @@ readgram (void)
 	  }			/* end of  read rhs of rule */
 
 	/* Put an empty link in the list to mark the end of this rule  */
-	p = symbol_list_new (NULL);
-	p1->next = p;
-	p1 = p;
+	grammar_symbol_append (NULL);
 
 	if (t == tok_prec)
 	  {
@@ -1307,15 +1308,17 @@ readgram (void)
      (not that of the start symbol):
 
      axiom: %start EOF.  */
-  p = symbol_list_new (axiom);
-  p->line = grammar->line;
-  p->next = symbol_list_new (startsymbol);
-  p->next->next = symbol_list_new (eoftoken);
-  p->next->next->next = symbol_list_new (NULL);
-  p->next->next->next->next = grammar;
-  nrules += 1;
-  nritems += 3;
-  grammar = p;
+  {
+    symbol_list *p = symbol_list_new (axiom);
+    p->line = grammar->line;
+    p->next = symbol_list_new (startsymbol);
+    p->next->next = symbol_list_new (eoftoken);
+    p->next->next->next = symbol_list_new (NULL);
+    p->next->next->next->next = grammar;
+    nrules += 1;
+    nritems += 3;
+    grammar = p;
+  }
 
   if (nsyms > SHRT_MAX)
     fatal (_("too many symbols (tokens plus nonterminals); maximum %d"),
-- 
2.47.2