--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/diag-aka-1.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+/* { dg-options "-Wc++-compat" } */
+
+typedef struct A { int i; } B;
+typedef struct T { int i; } T;
+typedef const float TFA;
+typedef TFA TFB;
+typedef TFB TFC;
+typedef int IA[];
+typedef IA *IAP;
+extern IAP arr[];
+
+void fn1 (B *); /* { dg-message "expected .B \\* {aka struct A \\*}. but argument is of type .struct B \\*." } */
+void fn2 (TFC *);
+
+void 
+bar (B *b, int *i)
+{
+  fn1 ((struct B *) b); /* { dg-warning "passing argument" } */
+  fn2 (i); /* { dg-warning "passing argument" } */
+  sizeof (arr); /* { dg-error "invalid application of .sizeof. to incomplete type .int \\(\\*\\\[\\\]\\)\\\[\\\]." } */
+}
+
+int
+foo (void *a)
+{
+  T *t = a; /* { dg-warning "request for implicit conversion from .void \\*. to .T \\* {aka struct T \\*}. not" } */
+  return t->i;
+}