PR c++/80605 - __is_standard_layout and zero-length array

	* class.c (check_bases): Use DECL_FIELD_IS_BASE.

From-SVN: r248470

gcc/cp/ChangeLog

+2017-05-25  Jason Merrill  <jason@redhat.com>
+
+	PR c++/80605 - __is_standard_layout and zero-length array
+	* class.c (check_bases): Use DECL_FIELD_IS_BASE.
+
 2017-05-25  Nathan Sidwell  <nathan@acm.org>
 
 	Kill OVL_CURRENT, OVL_NEXT.
@@ -727,6 +732,7 @@
 
 2017-05-09  Jason Merrill  <jason@redhat.com>
 
+	PR c++/80605 - __is_standard_layout and empty base
 	* class.c (check_bases): Ignore empty bases.
 
 	PR c++/70979 - literal class and closure types

gcc/cp/class.c

@@ -1842,8 +1842,8 @@ check_bases (tree t,
 	    for (basefield = TYPE_FIELDS (basetype); basefield;
 		 basefield = DECL_CHAIN (basefield))
 	      if (TREE_CODE (basefield) == FIELD_DECL
-		  && DECL_SIZE (basefield)
-		  && !integer_zerop (DECL_SIZE (basefield)))
+		  && !(DECL_FIELD_IS_BASE (basefield)
+		       && integer_zerop (DECL_SIZE (basefield))))
 		{
 		  if (field)
 		    CLASSTYPE_NON_STD_LAYOUT (t) = 1;

gcc/testsuite/g++.dg/ext/is_std_layout2.C

+// { dg-do compile { target c++11 } }
+// { dg-options "" }
+
+struct S { int a[0]; };
+struct T : public S { int b[0]; int c; };
+static_assert(!__is_standard_layout (T), "");