--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/Wcxx-compat-8.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,67 @@
+/* { dg-do compile } */
+/* { dg-options "-Wc++-compat" } */
+
+struct s1
+{
+  enum e1	/* { dg-message "note: enum type defined here" } */
+  {
+    A = sizeof (struct s2 { int i; }),	/* { dg-warning "invalid in C\[+\]\[+\]" } */
+    B
+  } f1;
+};
+struct s2 v1;	/* Don't issue another warning about s2.  */
+enum e1 v2;	/* { dg-warning "not visible in C\[+\]\[+\]" } */
+
+enum e2
+{
+  C = sizeof (struct s3 { int i; }),	/* { dg-warning "invalid in C\[+\]\[+\]" } */
+  D = __alignof__ (struct s4 { int i; }), /* { dg-warning "invalid in C\[+\]\[+\]" } */
+  E
+};
+
+struct s3 v3;
+int v4 = C;
+
+enum e3
+{
+  F = sizeof (struct t3),	/* { dg-bogus "invalid in C\[+\]\[+\]" } */
+  /* { dg-error "invalid application of 'sizeof'" "" { target *-*-* } .-1 } */
+  G = __alignof__ (struct t4), /* { dg-bogus "invalid in C\[+\]\[+\]" } */
+  /* { dg-error "invalid application of '__alignof__'" "" { target *-*-* } .-1 } */
+  H
+};
+
+__typeof__ (struct s5 { int i; }) v5; /* { dg-warning "invalid in C\[+\]\[+\]" } */
+__typeof__ (struct t5) w5; /* { dg-bogus "invalid in C\[+\]\[+\]" } */
+  /* { dg-error "storage size of 'w5' isn't known" "" { target *-*-* } .-1 } */
+
+int
+f1 (struct s1 *p)
+{
+  return ((struct s6 { int j; } *) p)->j;  /* { dg-warning "invalid in C\[+\]\[+\]" } */
+}
+
+void *
+f2 (struct s1 *p)
+{
+  return ((struct t6 *) p);  /* { dg-bogus "invalid in C\[+\]\[+\]" } */
+}
+
+int
+f3 (struct s1 *p)
+{
+  return (__extension__ (struct s7 { int j; } *)p)->j;
+}
+
+int
+f4 ()
+{
+  return (struct s8 { int i; }) { 0 }.i;  /* { dg-warning "invalid in C\[+\]\[+\]" } */
+}
+
+void *
+f5 ()
+{
+  return &((struct t8) { });  /* { dg-warning "invalid in C\[+\]\[+\]" } */
+  /* { dg-error "invalid use of undefined type" "" { target *-*-* } .-1 } */
+}