1 files changed, 19 insertions, 0 deletions
diff --git a/tests/run-make/extern-fn-with-union/test.rs b/tests/run-make/extern-fn-with-union/test.rs
new file mode 100644
index 000000000..438fbddf3
--- /dev/null
+++ b/tests/run-make/extern-fn-with-union/test.rs
@@ -0,0 +1,19 @@
+extern crate testcrate;
+
+use std::mem;
+
+extern "C" {
+    fn give_back(tu: testcrate::TestUnion) -> u64;
+}
+
+fn main() {
+    let magic: u64 = 0xDEADBEEF;
+
+    // Let's test calling it cross crate
+    let back = unsafe { testcrate::give_back(mem::transmute(magic)) };
+    assert_eq!(magic, back);
+
+    // And just within this crate
+    let back = unsafe { give_back(mem::transmute(magic)) };
+    assert_eq!(magic, back);
+}