--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/c11-anon-struct-1.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,72 @@
+/* Test for anonymous structures and unions in C11.  */
+/* { dg-do compile } */
+/* { dg-options "-std=c11 -pedantic-errors" } */
+
+#include <stddef.h>
+
+struct s1
+{
+  int a;
+  union
+  {
+    int i;
+  };
+  struct
+  {
+    int b;
+  };
+};
+
+union u1
+{
+  int b;
+  struct
+  {
+    int i;
+  };
+  union
+  {
+    int c;
+  };
+};
+
+struct s2
+{
+  struct
+  {
+    int a;
+  };
+};
+
+struct s3
+{
+  union
+  {
+    int i;
+  };
+};
+
+struct s4
+{
+  struct
+  {
+    int i;
+  };
+  int a[];
+};
+
+struct s1 x =
+  {
+    .b = 1,
+    .i = 2,
+    .a = 3
+  };
+
+int o = offsetof (struct s1, i);
+
+void
+f (void)
+{
+  x.i = 3;
+  (&x)->i = 4;
+}