* class.c (check_bases): Ignore empty bases.

From-SVN: r247816

gcc/cp/ChangeLog

 2017-05-09  Jason Merrill  <jason@redhat.com>
 
+	* class.c (check_bases): Ignore empty bases.
+
 	PR c++/70979 - literal class and closure types
 	* class.c (finalize_literal_type_property): Handle closures
 	specifically.

gcc/cp/class.c

@@ -1860,7 +1860,9 @@ check_bases (tree t,
 	       members */
 	    for (basefield = TYPE_FIELDS (basetype); basefield;
 		 basefield = DECL_CHAIN (basefield))
-	      if (TREE_CODE (basefield) == FIELD_DECL)
+	      if (TREE_CODE (basefield) == FIELD_DECL
+		  && DECL_SIZE (basefield)
+		  && !integer_zerop (DECL_SIZE (basefield)))
 		{
 		  if (field)
 		    CLASSTYPE_NON_STD_LAYOUT (t) = 1;

gcc/testsuite/g++.dg/ext/is_std_layout1.C

+// { dg-do compile { target c++11 } }
+
+template <int> struct E { };
+
+struct E1: E<0>, E<1> { };
+struct E2: E<2>, E<3> { };
+
+struct A1x { int n; };
+struct D2: A1x, E1, E2 { };
+
+#define SA(X) static_assert((X),#X)
+SA(__is_standard_layout (D2));