1 files changed, 173 insertions, 0 deletions
diff --git a/tests/ui/union/union-packed.rs b/tests/ui/union/union-packed.rs
new file mode 100644
index 00000000000..9c6398bf5aa
--- /dev/null
+++ b/tests/ui/union/union-packed.rs
@@ -0,0 +1,173 @@
+// run-pass
+// revisions: mirunsafeck thirunsafeck
+// [thirunsafeck]compile-flags: -Z thir-unsafeck
+
+#![allow(dead_code)]
+#![allow(non_snake_case)]
+
+use std::mem::{size_of, size_of_val, align_of, align_of_val};
+
+struct S {
+    a: u16,
+    b: [u8; 3],
+}
+
+#[repr(packed)]
+struct Sp1 {
+    a: u16,
+    b: [u8; 3],
+}
+
+#[repr(packed(2))]
+struct Sp2 {
+    a: u16,
+    b: [u8; 3],
+}
+
+union U {
+    a: u16,
+    b: [u8; 3],
+}
+
+#[repr(packed)]
+union Up1 {
+    a: u16,
+    b: [u8; 3],
+}
+
+#[repr(packed(2))]
+union Up2 {
+    a: u16,
+    b: [u8; 3],
+}
+
+#[repr(C, packed(4))]
+union Up4c {
+    a: u16,
+    b: [u8; 3],
+}
+
+const CS: S = S { a: 0, b: [0, 0, 0] };
+const CSP1: Sp1 = Sp1 { a: 0, b: [0, 0, 0] };
+const CSP2: Sp2 = Sp2 { a: 0, b: [0, 0, 0] };
+const CU: U = U { b: [0, 0, 0] };
+const CUP1: Up1 = Up1 { b: [0, 0, 0] };
+const CUP2: Up2 = Up2 { b: [0, 0, 0] };
+const CUP4C: Up4c = Up4c { b: [0, 0, 0] };
+
+fn main() {
+    let s = S { a: 0, b: [0, 0, 0] };
+    assert_eq!(size_of::<S>(), 6);
+    assert_eq!(size_of_val(&s), 6);
+    assert_eq!(size_of_val(&CS), 6);
+    assert_eq!(align_of::<S>(), 2);
+    assert_eq!(align_of_val(&s), 2);
+    assert_eq!(align_of_val(&CS), 2);
+
+    let sp1 = Sp1 { a: 0, b: [0, 0, 0] };
+    assert_eq!(size_of::<Sp1>(), 5);
+    assert_eq!(size_of_val(&sp1), 5);
+    assert_eq!(size_of_val(&CSP1), 5);
+    assert_eq!(align_of::<Sp1>(), 1);
+    assert_eq!(align_of_val(&sp1), 1);
+    assert_eq!(align_of_val(&CSP1), 1);
+
+    let sp2 = Sp2 { a: 0, b: [0, 0, 0] };
+    assert_eq!(size_of::<Sp2>(), 6);
+    assert_eq!(size_of_val(&sp2), 6);
+    assert_eq!(size_of_val(&CSP2), 6);
+    assert_eq!(align_of::<Sp2>(), 2);
+    assert_eq!(align_of_val(&sp2), 2);
+    assert_eq!(align_of_val(&CSP2), 2);
+
+    let u = U { b: [0, 0, 0] };
+    assert_eq!(size_of::<U>(), 4);
+    assert_eq!(size_of_val(&u), 4);
+    assert_eq!(size_of_val(&CU), 4);
+    assert_eq!(align_of::<U>(), 2);
+    assert_eq!(align_of_val(&u), 2);
+    assert_eq!(align_of_val(&CU), 2);
+
+    let Up1 = Up1 { b: [0, 0, 0] };
+    assert_eq!(size_of::<Up1>(), 3);
+    assert_eq!(size_of_val(&Up1), 3);
+    assert_eq!(size_of_val(&CUP1), 3);
+    assert_eq!(align_of::<Up1>(), 1);
+    assert_eq!(align_of_val(&Up1), 1);
+    assert_eq!(align_of_val(&CUP1), 1);
+
+    let up2 = Up2 { b: [0, 0, 0] };
+    assert_eq!(size_of::<Up2>(), 4);
+    assert_eq!(size_of_val(&up2), 4);
+    assert_eq!(size_of_val(&CUP2), 4);
+    assert_eq!(align_of::<Up2>(), 2);
+    assert_eq!(align_of_val(&up2), 2);
+    assert_eq!(align_of_val(&CUP2), 2);
+
+    let up4c = Up4c { b: [0, 0, 0] };
+    assert_eq!(size_of::<Up4c>(), 4);
+    assert_eq!(size_of_val(&up4c), 4);
+    assert_eq!(size_of_val(&CUP4C), 4);
+    assert_eq!(align_of::<Up4c>(), 2);
+    assert_eq!(align_of_val(&up4c), 2);
+    assert_eq!(align_of_val(&CUP4C), 2);
+
+    hybrid::check_hybrid();
+}
+
+mod hybrid {
+    use std::mem::{size_of, align_of};
+
+    #[repr(packed)]
+    #[derive(Copy, Clone)]
+    struct S1 {
+        a: u16,
+        b: u8,
+    }
+
+    #[repr(packed)]
+    union U {
+        s: S1,
+        c: u16,
+    }
+
+    #[repr(packed)]
+    struct S2 {
+        d: u8,
+        u: U,
+    }
+
+    #[repr(C, packed(2))]
+    struct S1C {
+        a: u16,
+        b: u8,
+    }
+
+    #[repr(C, packed(2))]
+    union UC {
+        s: S1,
+        c: u16,
+    }
+
+    #[repr(C, packed(2))]
+    struct S2C {
+        d: u8,
+        u: UC,
+    }
+
+    pub fn check_hybrid() {
+        assert_eq!(align_of::<S1>(), 1);
+        assert_eq!(size_of::<S1>(), 3);
+        assert_eq!(align_of::<U>(), 1);
+        assert_eq!(size_of::<U>(), 3);
+        assert_eq!(align_of::<S2>(), 1);
+        assert_eq!(size_of::<S2>(), 4);
+
+        assert_eq!(align_of::<S1C>(), 2);
+        assert_eq!(size_of::<S1C>(), 4);
+        assert_eq!(align_of::<UC>(), 2);
+        assert_eq!(size_of::<UC>(), 4);
+        assert_eq!(align_of::<S2C>(), 2);
+        assert_eq!(size_of::<S2C>(), 6);
+    }
+}