1 files changed, 32 insertions, 0 deletions
diff --git a/tests/ui/closures/2229_closure_analysis/diagnostics/repr_packed.rs b/tests/ui/closures/2229_closure_analysis/diagnostics/repr_packed.rs
new file mode 100644
index 000000000..1488f3296
--- /dev/null
+++ b/tests/ui/closures/2229_closure_analysis/diagnostics/repr_packed.rs
@@ -0,0 +1,32 @@
+// edition:2021
+
+// Given how the closure desugaring is implemented (at least at the time of writing this test),
+// we don't need to truncate the captured path to a reference into a packed-struct if the field
+// being referenced will be moved into the closure, since it's safe to move out a field from a
+// packed-struct.
+//
+// However to avoid surprises for the user, or issues when the closure is
+// inlined we will truncate the capture to access just the struct regardless of if the field
+// might get moved into the closure.
+//
+// It is possible for someone to try writing the code that relies on the desugaring to create a ref
+// into a packed-struct. Here we test that the compiler still detects that case.
+fn test_missing_unsafe_warning_on_repr_packed() {
+    #[repr(packed)]
+    struct Foo { x: String }
+
+    let foo = Foo { x: String::new() };
+
+    let c = || {
+        println!("{}", foo.x);
+        //~^ ERROR: reference to packed field is unaligned
+        //~| WARNING: this was previously accepted by the compiler but is being phased out
+        let _z = foo.x;
+    };
+
+    c();
+}
+
+fn main() {
+    test_missing_unsafe_warning_on_repr_packed();
+}