--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/coroutines/co-yield-syntax-08-needs-expr.C	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,37 @@
+//  { dg-additional-options "-fsyntax-only -w" }
+
+// Check syntax for missing expr in a coroutine context.
+
+#include "coro.h"
+
+struct DummyYield {
+  coro::coroutine_handle<> handle;
+  DummyYield () : handle (nullptr) {}
+  DummyYield (coro::coroutine_handle<> handle) : handle (handle) {}
+  struct dummy_yield {
+    coro::suspend_never initial_suspend() { return {}; }
+    coro::suspend_never final_suspend() { return {}; }
+    DummyYield get_return_object() {
+      return DummyYield (coro::coroutine_handle<dummy_yield>::from_promise (*this));
+    }
+    void yield_value (int v) {}
+    void return_value (int v) {}
+    void unhandled_exception() { /*std::terminate();*/ };
+  };
+};
+
+template<> struct coro::coroutine_traits<DummyYield> {
+    using promise_type = DummyYield::dummy_yield;
+};
+
+DummyYield
+bar ()
+{
+  co_yield; // { dg-error {expected primary-expression before} }
+  co_return 0;
+}
+
+int main (int ac, char *av[]) {
+  DummyYield x = bar ();
+  return 0;
+}