semantics.c (cxx_eval_call_expression): Handle trivial value-initialization.

	* semantics.c (cxx_eval_call_expression): Handle trivial
	value-initialization.
	* typeck2.c (store_init_value): Call maybe_constant_init after
	cxx_constant_value.

From-SVN: r204266

gcc/cp/ChangeLog

 2013-10-31  Jason Merrill  <jason@redhat.com>
 
+	* semantics.c (cxx_eval_call_expression): Handle trivial
+	value-initialization.
+	* typeck2.c (store_init_value): Call maybe_constant_init after
+	cxx_constant_value.
+
 	* decl.c (cxx_maybe_build_cleanup): Always set LOOKUP_NONVIRTUAL.
 	* decl2.c (build_cleanup): Just call cxx_maybe_build_cleanup.
 

gcc/cp/semantics.c

@@ -8289,12 +8289,18 @@ cxx_eval_call_expression (const constexpr_call *old_call, tree t,
       return t;
     }
 
-  /* Shortcut trivial copy constructor/op=.  */
-  if (call_expr_nargs (t) == 2 && trivial_fn_p (fun))
+  /* Shortcut trivial constructor/op=.  */
+  if (trivial_fn_p (fun))
     {
-      tree arg = convert_from_reference (get_nth_callarg (t, 1));
-      return cxx_eval_constant_expression (old_call, arg, allow_non_constant,
-					   addr, non_constant_p, overflow_p);
+      if (call_expr_nargs (t) == 2)
+	{
+	  tree arg = convert_from_reference (get_nth_callarg (t, 1));
+	  return cxx_eval_constant_expression (old_call, arg, allow_non_constant,
+					       addr, non_constant_p, overflow_p);
+	}
+      else if (TREE_CODE (t) == AGGR_INIT_EXPR
+	       && AGGR_INIT_ZERO_FIRST (t))
+	return build_zero_init (DECL_CONTEXT (fun), NULL_TREE, false);
     }
 
   /* If in direct recursive call, optimize definition search.  */

gcc/cp/typeck2.c

@@ -775,7 +775,6 @@ store_init_value (tree decl, tree init, vec<tree, va_gc>** cleanups, int flags)
     {
       bool const_init;
       value = fold_non_dependent_expr (value);
-      value = maybe_constant_init (value);
       if (DECL_DECLARED_CONSTEXPR_P (decl)
 	  || DECL_IN_AGGR_P (decl))
 	{
@@ -786,6 +785,7 @@ store_init_value (tree decl, tree init, vec<tree, va_gc>** cleanups, int flags)
 	  else
 	    value = cxx_constant_value (value);
 	}
+      value = maybe_constant_init (value);
       const_init = (reduced_constant_expression_p (value)
 		    || error_operand_p (value));
       DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = const_init;