constexpr.c (cxx_eval_call_expression): Don't talk about flowing off the end if…

constexpr.c (cxx_eval_call_expression): Don't talk about flowing off the end if we're already non-constant.

	* constexpr.c (cxx_eval_call_expression): Don't talk about
	flowing off the end if we're already non-constant.

From-SVN: r218092

gcc/cp/ChangeLog

+2014-11-26  Jason Merrill  <jason@redhat.com>
+
+	* constexpr.c (cxx_eval_call_expression): Don't talk about
+	flowing off the end if we're already non-constant.
+
 2014-11-26  Ville Voutilainen  <ville.voutilainen@gmail.com>
 
 	Diagnose string constant conversion to char* in c++11 and above

gcc/cp/constexpr.c

@@ -1344,7 +1344,7 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
 	      else
 		{
 		  result = *ctx->values->get (slot ? slot : res);
-		  if (result == NULL_TREE)
+		  if (result == NULL_TREE && !*non_constant_p)
 		    {
 		      if (!ctx->quiet)
 			error ("constexpr call flows off the end "