1 files changed, 17 insertions, 0 deletions
diff --git a/src/test/ui/lint/lint-ctypes-66202.rs b/src/test/ui/lint/lint-ctypes-66202.rs
new file mode 100644
index 000000000..ebab41d14
--- /dev/null
+++ b/src/test/ui/lint/lint-ctypes-66202.rs
@@ -0,0 +1,17 @@
+// check-pass
+
+#![deny(improper_ctypes)]
+
+// This test checks that return types are normalized before being checked for FFI-safety, and that
+// transparent newtype wrappers are FFI-safe if the type being wrapped is FFI-safe.
+
+#[repr(transparent)]
+pub struct W<T>(T);
+
+extern "C" {
+    pub fn bare() -> ();
+    pub fn normalize() -> <() as ToOwned>::Owned;
+    pub fn transparent() -> W<()>;
+}
+
+fn main() {}