4 files changed, 46 insertions, 0 deletions
diff --git a/tests/run-make-fulldeps/extern-fn-with-union/Makefile b/tests/run-make-fulldeps/extern-fn-with-union/Makefile
new file mode 100644
index 000000000..40bae923e
--- /dev/null
+++ b/tests/run-make-fulldeps/extern-fn-with-union/Makefile
@@ -0,0 +1,6 @@
+include ../tools.mk
+
+all: $(call NATIVE_STATICLIB,ctest)
+	$(RUSTC) testcrate.rs
+	$(RUSTC) test.rs
+	$(call RUN,test) || exit 1
diff --git a/tests/run-make-fulldeps/extern-fn-with-union/ctest.c b/tests/run-make-fulldeps/extern-fn-with-union/ctest.c
new file mode 100644
index 000000000..86cb64537
--- /dev/null
+++ b/tests/run-make-fulldeps/extern-fn-with-union/ctest.c
@@ -0,0 +1,10 @@
+#include <stdio.h>
+#include <stdint.h>
+
+typedef union TestUnion {
+    uint64_t bits;
+} TestUnion;
+
+uint64_t give_back(TestUnion tu) {
+    return tu.bits;
+}
diff --git a/tests/run-make-fulldeps/extern-fn-with-union/test.rs b/tests/run-make-fulldeps/extern-fn-with-union/test.rs
new file mode 100644
index 000000000..438fbddf3
--- /dev/null
+++ b/tests/run-make-fulldeps/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);
+}
diff --git a/tests/run-make-fulldeps/extern-fn-with-union/testcrate.rs b/tests/run-make-fulldeps/extern-fn-with-union/testcrate.rs
new file mode 100644
index 000000000..28d91ff37
--- /dev/null
+++ b/tests/run-make-fulldeps/extern-fn-with-union/testcrate.rs
@@ -0,0 +1,11 @@
+#![crate_type = "lib"]
+
+#[repr(C)]
+pub struct TestUnion {
+    _val: u64,
+}
+
+#[link(name = "ctest", kind = "static")]
+extern "C" {
+    pub fn give_back(tu: TestUnion) -> u64;
+}