Fix minor white space and indentation problems.

[bison.git] / src / reader.c

diff --git a/src/reader.c b/src/reader.c
index 877e2c71460941115310367f502a8fc9f79ddaa4..f2370a989b7d164e813230097a052bd5633377d3 100644 (file)
--- a/src/reader.c
+++ b/src/reader.c
@@ -1,7 +1,7 @@
 /* Input parser for Bison
 
    Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002, 2003,
-   2005 Free Software Foundation, Inc.
+   2005, 2006 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -210,6 +210,20 @@ grammar_current_rule_begin (symbol *lhs, location loc)
 }
 
 
+/*-----------------------------------------------------------------.
+| A symbol is typed if it has a declared %type, or if it is a      |
+| mid-rule symbol (i.e., the generated LHS replacing a mid-rule    |
+| action) that was assigned to, as in `exp: { $$ = 1; } { $$ = $1; |
+| }'.                                                              |
+`-----------------------------------------------------------------*/
+
+static bool
+symbol_typed_p (const symbol_list *s)
+{
+  return (s->sym->type_name
+         || s->midrule && s->midrule->used);
+}
+
 /*----------------------------------------------------------------.
 | Check that the rule R is properly defined.  For instance, there |
 | should be no type clash on the default action.                  |
@@ -247,17 +261,19 @@ grammar_rule_check (const symbol_list *r)
 
   /* Check that typed symbol values are used.  */
   {
-    symbol_list *l = r;
+    symbol_list const *l = r;
     int n = 0;
     for (; l && l->sym; l = l->next, ++n)
       if (! (l->used
-            || !l->sym->type_name
+            || !symbol_typed_p (l)
             /* The default action, $$ = $1, `uses' both.  */
-            || !r->action && (n == 0 || n == 1)))
-       if (n)
-         warn_at (r->location, _("unused value: $%d"), n);
-       else
-         warn_at (r->location, _("unset value: $$"));
+            || (!r->action && (n == 0 || n == 1))))
+       {
+         if (n)
+           warn_at (r->location, _("unused value: $%d"), n);
+         else
+           warn_at (r->location, _("unset value: $$"));
+       }
   }
 }
 
@@ -305,6 +321,10 @@ grammar_midrule_action (void)
   midrule->action = current_rule->action;
   midrule->action_location = dummy_location;
   current_rule->action = NULL;
+  /* If $$ was used in the action, the LHS of the enclosing rule was
+     incorrectly flagged as used.  */
+  midrule->used = current_rule->used;
+  current_rule->used = false;
 
   if (previous_rule_end)
     previous_rule_end->next = midrule;
@@ -312,14 +332,16 @@ grammar_midrule_action (void)
     grammar = midrule;
 
   /* End the dummy's rule.  */
-  previous_rule_end = symbol_list_new (NULL, dummy_location);
-  previous_rule_end->next = current_rule;
+  midrule->next = symbol_list_new (NULL, dummy_location);
+  grammar_rule_check (midrule);
+  midrule->next->next = current_rule;
 
-  midrule->next = previous_rule_end;
+  previous_rule_end = midrule->next;
 
   /* Insert the dummy nonterminal replacing the midrule action into
-     the current rule.  */
+     the current rule.  Bind it to its dedicated rule.  */
   grammar_current_rule_symbol_append (dummy, dummy_location);
+  grammar_end->midrule = midrule;
 }
 
 /* Set the precedence symbol of the current rule to PRECSYM. */