1 files changed, 53 insertions, 0 deletions
diff --git a/tests/ui/attributes/may_dangle.rs b/tests/ui/attributes/may_dangle.rs
new file mode 100644
index 00000000000..209ba0e88ad
--- /dev/null
+++ b/tests/ui/attributes/may_dangle.rs
@@ -0,0 +1,53 @@
+#![feature(dropck_eyepatch)]
+
+struct Implee1<'a, T, const N: usize>(&'a T);
+struct Implee2<'a, T, const N: usize>(&'a T);
+struct Implee3<'a, T, const N: usize>(&'a T);
+trait NotDrop {}
+
+unsafe impl<#[may_dangle] 'a, T, const N: usize> NotDrop for Implee1<'a, T, N> {}
+//~^ ERROR must be applied to a lifetime or type generic parameter in `Drop` impl
+
+unsafe impl<'a, #[may_dangle] T, const N: usize> NotDrop for Implee2<'a, T, N> {}
+//~^ ERROR must be applied to a lifetime or type generic parameter in `Drop` impl
+
+unsafe impl<'a, T, #[may_dangle] const N: usize> Drop for Implee1<'a, T, N> {
+    //~^ ERROR must be applied to a lifetime or type generic parameter in `Drop` impl
+    fn drop(&mut self) {}
+}
+
+// Ok, lifetime param in a `Drop` impl.
+unsafe impl<#[may_dangle] 'a, T, const N: usize> Drop for Implee2<'a, T, N> {
+    fn drop(&mut self) {}
+}
+
+// Ok, type param in a `Drop` impl.
+unsafe impl<'a, #[may_dangle] T, const N: usize> Drop for Implee3<'a, T, N> {
+    fn drop(&mut self) {}
+}
+
+// Check that this check is not textual.
+mod fake {
+    trait Drop {
+        fn drop(&mut self);
+    }
+    struct Implee<T>(T);
+
+    unsafe impl<#[may_dangle] T> Drop for Implee<T> {
+        //~^ ERROR must be applied to a lifetime or type generic parameter in `Drop` impl
+        fn drop(&mut self) {}
+    }
+}
+
+#[may_dangle] //~ ERROR must be applied to a lifetime or type generic parameter in `Drop` impl
+struct Dangling;
+
+#[may_dangle] //~ ERROR must be applied to a lifetime or type generic parameter in `Drop` impl
+impl NotDrop for () {
+}
+
+#[may_dangle] //~ ERROR must be applied to a lifetime or type generic parameter in `Drop` impl
+fn main() {
+    #[may_dangle] //~ ERROR must be applied to a lifetime or type generic parameter in `Drop` impl
+    let () = ();
+}