From 98a5b24ef7eb05ae52d63ce9e050d6ac144ba345 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Tue, 14 Aug 2018 20:09:07 +0200
Subject: [PATCH] test some more things around packed structs

---
 tests/run-pass/dst-struct.rs    |  4 ++--
 tests/run-pass/packed_struct.rs | 39 +++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/tests/run-pass/dst-struct.rs b/tests/run-pass/dst-struct.rs
index 932b571eccdb..0820614ab5c8 100644
--- a/tests/run-pass/dst-struct.rs
+++ b/tests/run-pass/dst-struct.rs
@@ -65,9 +65,9 @@ impl ToBar for Bar {
 
 pub fn main() {
     // With a vec of ints.
-    let f1 = Fat { f1: 5, f2: "some str", ptr: [1, 2, 3] };
+    let f1 : Fat<[isize; 3]> = Fat { f1: 5, f2: "some str", ptr: [1, 2, 3] };
     foo(&f1);
-    let f2 = &f1;
+    let f2 : &Fat<[isize; 3]> = &f1;
     foo(f2);
     let f3: &Fat<[isize]> = f2;
     foo(f3);
diff --git a/tests/run-pass/packed_struct.rs b/tests/run-pass/packed_struct.rs
index 7bd04c44438c..e10781e65605 100644
--- a/tests/run-pass/packed_struct.rs
+++ b/tests/run-pass/packed_struct.rs
@@ -45,6 +45,43 @@ fn test_unsizing() {
     let _unused = &arr_unaligned; // forcing an allocation, which could also yield "unaligned write"-errors
 }
 
+fn test_drop() {
+    struct Wrap(u32);
+    impl Drop for Wrap {
+        fn drop(&mut self) {
+            // Do an (aligned) load
+            let _test = self.0;
+            // For the fun of it, test alignment
+            assert_eq!(&self.0 as *const _ as usize % std::mem::align_of::<u32>(), 0);
+        }
+    }
+
+    #[repr(packed,C)]
+    struct Packed<T> {
+        f1: u8, // this should move the second field to something not very aligned
+        f2: T,
+    }
+
+    let p = Packed { f1: 42, f2: Wrap(23) };
+    drop(p);
+}
+
+fn test_inner_packed() {
+    // Even if just the inner struct is packed, accesses to the outer field can get unaligned.
+    // Make sure that works.
+    #[repr(packed)]
+    #[derive(Clone,Copy)]
+    struct Inner(u32);
+
+    #[derive(Clone,Copy)]
+    struct Outer(u8, Inner);
+
+    let o = Outer(0, Inner(42));
+    let _x = o.1;
+    let _y = (o.1).0;
+    let _o2 = o.clone();
+}
+
 fn main() {
     let mut x = S {
         a: 42,
@@ -64,4 +101,6 @@ fn main() {
     test(Test2 { x: 0, other: &Test1 { x: 0, other: &42 }});
 
     test_unsizing();
+    test_drop();
+    test_inner_packed();
 }