5 files changed, 94 insertions, 10 deletions
diff --git a/src/test/ui/lint/must_not_suspend/ref-drop-tracking.rs b/src/test/ui/lint/must_not_suspend/ref-drop-tracking.rs
new file mode 100644
index 000000000..1bc4a3812
--- /dev/null
+++ b/src/test/ui/lint/must_not_suspend/ref-drop-tracking.rs
@@ -0,0 +1,30 @@
+// edition:2018
+// compile-flags: -Zdrop-tracking
+#![feature(must_not_suspend)]
+#![deny(must_not_suspend)]
+
+#[must_not_suspend = "You gotta use Umm's, ya know?"]
+struct Umm {
+    i: i64
+}
+
+struct Bar {
+    u: Umm,
+}
+
+async fn other() {}
+
+impl Bar {
+    async fn uhoh(&mut self) {
+        let guard = &mut self.u; //~ ERROR `Umm` held across
+
+        other().await;
+
+        *guard = Umm {
+            i: 2
+        }
+    }
+}
+
+fn main() {
+}
diff --git a/src/test/ui/lint/must_not_suspend/ref-drop-tracking.stderr b/src/test/ui/lint/must_not_suspend/ref-drop-tracking.stderr
new file mode 100644
index 000000000..c49d27128
--- /dev/null
+++ b/src/test/ui/lint/must_not_suspend/ref-drop-tracking.stderr
@@ -0,0 +1,27 @@
+error: reference to `Umm` held across a suspend point, but should not be
+  --> $DIR/ref-drop-tracking.rs:19:13
+   |
+LL |         let guard = &mut self.u;
+   |             ^^^^^
+LL |
+LL |         other().await;
+   |                ------ the value is held across this suspend point
+   |
+note: the lint level is defined here
+  --> $DIR/ref-drop-tracking.rs:4:9
+   |
+LL | #![deny(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+note: You gotta use Umm's, ya know?
+  --> $DIR/ref-drop-tracking.rs:19:13
+   |
+LL |         let guard = &mut self.u;
+   |             ^^^^^
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/ref-drop-tracking.rs:19:13
+   |
+LL |         let guard = &mut self.u;
+   |             ^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/lint/must_not_suspend/ref.drop_tracking.stderr b/src/test/ui/lint/must_not_suspend/ref.drop_tracking.stderr
new file mode 100644
index 000000000..0157c8b7f
--- /dev/null
+++ b/src/test/ui/lint/must_not_suspend/ref.drop_tracking.stderr
@@ -0,0 +1,27 @@
+error: reference to `Umm` held across a suspend point, but should not be
+  --> $DIR/ref.rs:21:13
+   |
+LL |         let guard = &mut self.u;
+   |             ^^^^^
+LL |
+LL |         other().await;
+   |                ------ the value is held across this suspend point
+   |
+note: the lint level is defined here
+  --> $DIR/ref.rs:6:9
+   |
+LL | #![deny(must_not_suspend)]
+   |         ^^^^^^^^^^^^^^^^
+note: You gotta use Umm's, ya know?
+  --> $DIR/ref.rs:21:13
+   |
+LL |         let guard = &mut self.u;
+   |             ^^^^^
+help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
+  --> $DIR/ref.rs:21:13
+   |
+LL |         let guard = &mut self.u;
+   |             ^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/lint/must_not_suspend/ref.stderr b/src/test/ui/lint/must_not_suspend/ref.no_drop_tracking.stderr
index 5f000014c..438e6489e 100644
--- a/src/test/ui/lint/must_not_suspend/ref.stderr
+++ b/src/test/ui/lint/must_not_suspend/ref.no_drop_tracking.stderr
@@ -1,5 +1,5 @@
 error: `Umm` held across a suspend point, but should not be
-  --> $DIR/ref.rs:18:26
+  --> $DIR/ref.rs:21:26
    |
 LL |         let guard = &mut self.u;
    |                          ^^^^^^
@@ -8,17 +8,17 @@ LL |         other().await;
    |                ------ the value is held across this suspend point
    |
 note: the lint level is defined here
-  --> $DIR/ref.rs:3:9
+  --> $DIR/ref.rs:6:9
    |
 LL | #![deny(must_not_suspend)]
    |         ^^^^^^^^^^^^^^^^
 note: You gotta use Umm's, ya know?
-  --> $DIR/ref.rs:18:26
+  --> $DIR/ref.rs:21:26
    |
 LL |         let guard = &mut self.u;
    |                          ^^^^^^
 help: consider using a block (`{ ... }`) to shrink the value's scope, ending before the suspend point
-  --> $DIR/ref.rs:18:26
+  --> $DIR/ref.rs:21:26
    |
 LL |         let guard = &mut self.u;
    |                          ^^^^^^
diff --git a/src/test/ui/lint/must_not_suspend/ref.rs b/src/test/ui/lint/must_not_suspend/ref.rs
index 738dd9e04..f6b23746f 100644
--- a/src/test/ui/lint/must_not_suspend/ref.rs
+++ b/src/test/ui/lint/must_not_suspend/ref.rs
@@ -1,10 +1,13 @@
 // edition:2018
+// revisions: no_drop_tracking drop_tracking
+// [drop_tracking] compile-flags: -Zdrop-tracking=yes
+// [no_drop_tracking] compile-flags: -Zdrop-tracking=no
 #![feature(must_not_suspend)]
 #![deny(must_not_suspend)]
 
 #[must_not_suspend = "You gotta use Umm's, ya know?"]
 struct Umm {
-    i: i64
+    i: i64,
 }
 
 struct Bar {
@@ -19,11 +22,8 @@ impl Bar {
 
         other().await;
 
-        *guard = Umm {
-            i: 2
-        }
+        *guard = Umm { i: 2 }
     }
 }
 
-fn main() {
-}
+fn main() {}