* src/reader.c (grammar_end, grammar_symbol_append): New.

[bison.git] / src / reader.c

diff --git a/src/reader.c b/src/reader.c
index f2bc42e724db4bf926575c3939a92651d3c0a59d..d1a6b9aa7b6d67590d8d3f0d55b161aedec86fea 100644 (file)
--- 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"),