1 files changed, 65 insertions, 0 deletions
diff --git a/src/test/mir-opt/retag.rs b/src/test/mir-opt/retag.rs
new file mode 100644
index 000000000..13568b822
--- /dev/null
+++ b/src/test/mir-opt/retag.rs
@@ -0,0 +1,65 @@
+// ignore-wasm32-bare compiled with panic=abort by default
+// ignore-tidy-linelength
+// compile-flags: -Z mir-emit-retag -Z mir-opt-level=0 -Z span_free_formats
+
+#![allow(unused)]
+
+struct Test(i32);
+
+// EMIT_MIR retag.{impl#0}-foo.SimplifyCfg-elaborate-drops.after.mir
+// EMIT_MIR retag.{impl#0}-foo_shr.SimplifyCfg-elaborate-drops.after.mir
+impl Test {
+    // Make sure we run the pass on a method, not just on bare functions.
+    fn foo<'x>(&self, x: &'x mut i32) -> &'x mut i32 {
+        x
+    }
+    fn foo_shr<'x>(&self, x: &'x i32) -> &'x i32 {
+        x
+    }
+}
+
+// EMIT_MIR core.ptr-drop_in_place.Test.SimplifyCfg-make_shim.after.mir
+
+impl Drop for Test {
+    fn drop(&mut self) {}
+}
+
+// EMIT_MIR retag.main.SimplifyCfg-elaborate-drops.after.mir
+// EMIT_MIR retag.main-{closure#0}.SimplifyCfg-elaborate-drops.after.mir
+fn main() {
+    let mut x = 0;
+    {
+        let v = Test(0).foo(&mut x); // just making sure we do not panic when there is a tuple struct ctor
+        let w = { v }; // assignment
+        let w = w; // reborrow
+        // escape-to-raw (mut)
+        let _w = w as *mut _;
+    }
+
+    // Also test closures
+    let c: fn(&i32) -> &i32 = |x: &i32| -> &i32 {
+        let _y = x;
+        x
+    };
+    let _w = c(&x);
+
+    // need to call `foo_shr` or it doesn't even get generated
+    Test(0).foo_shr(&0);
+
+    // escape-to-raw (shr)
+    let _w = _w as *const _;
+
+    array_casts();
+}
+
+/// Casting directly to an array should also go through `&raw` and thus add appropriate retags.
+// EMIT_MIR retag.array_casts.SimplifyCfg-elaborate-drops.after.mir
+fn array_casts() {
+    let mut x: [usize; 2] = [0, 0];
+    let p = &mut x as *mut usize;
+    unsafe { *p.add(1) = 1; }
+
+    let x: [usize; 2] = [0, 1];
+    let p = &x as *const usize;
+    assert_eq!(unsafe { *p.add(1) }, 1);
+}