re PR c++/13683 (bogus warning about passing non-PODs through ellipsis)

	PR c++/13683
	* call.c (convert_arg_to_ellipsis): Don't emit a warning if within
	a sizeof expression.block

From-SVN: r76963

gcc/cp/ChangeLog

+2004-01-30  Giovanni Bajo  <giovannibajo@gcc.gnu.org>
+
+	PR c++/13683
+	* call.c (convert_arg_to_ellipsis): Don't emit a warning if within
+	a sizeof expression.block
+
 2004-01-29  Mark Mitchell  <mark@codesourcery.com>
 
 	PR c++/13883

gcc/cp/call.c

@@ -4127,14 +4127,18 @@ convert_arg_to_ellipsis (tree arg)
 
   arg = require_complete_type (arg);
   
-  if (arg != error_mark_node && ! pod_type_p (TREE_TYPE (arg)))
+  if (arg != error_mark_node
+      && !pod_type_p (TREE_TYPE (arg)))
     {
       /* Undefined behavior [expr.call] 5.2.2/7.  We used to just warn
 	 here and do a bitwise copy, but now cp_expr_size will abort if we
-	 try to do that.  */
-      warning ("cannot pass objects of non-POD type `%#T' through `...'; \
-call will abort at runtime",
-	       TREE_TYPE (arg));
+	 try to do that. 
+	 If the call appears in the context of a sizeof expression, 
+	 there is no need to emit a warning, since the expression won't be 
+	 evaluated. We keep the builtin_trap just as a safety check.  */
+      if (!skip_evaluation)
+	warning ("cannot pass objects of non-POD type `%#T' through `...'; "
+	         "call will abort at runtime", TREE_TYPE (arg));
       arg = call_builtin_trap (TREE_TYPE (arg));
     }