1 files changed, 30 insertions, 0 deletions
diff --git a/tests/ui/async-await/async-is-unwindsafe.rs b/tests/ui/async-await/async-is-unwindsafe.rs
new file mode 100644
index 00000000000..56ed2847292
--- /dev/null
+++ b/tests/ui/async-await/async-is-unwindsafe.rs
@@ -0,0 +1,30 @@
+// edition:2018
+
+fn is_unwindsafe(_: impl std::panic::UnwindSafe) {}
+
+fn main() {
+    // A normal future created by an async block takes a `&mut Context<'_>` argument.
+    // That should not leak through to the whole async block.
+    is_unwindsafe(async {
+        async {}.await; // this needs an inner await point
+    });
+
+    is_unwindsafe(async {
+        //~^ ERROR the type `&mut Context<'_>` may not be safely transferred across an unwind boundary
+        use std::ptr::null;
+        use std::task::{Context, RawWaker, RawWakerVTable, Waker};
+        let waker = unsafe {
+            Waker::from_raw(RawWaker::new(
+                null(),
+                &RawWakerVTable::new(|_| todo!(), |_| todo!(), |_| todo!(), |_| todo!()),
+            ))
+        };
+        let mut cx = Context::from_waker(&waker);
+        let cx_ref = &mut cx;
+
+        async {}.await; // this needs an inner await point
+
+        // in this case, `&mut Context<'_>` is *truly* alive across an await point
+        drop(cx_ref);
+    });
+}