1 files changed, 28 insertions, 0 deletions
diff --git a/tests/ui/codegen/sret-aliasing-rules.rs b/tests/ui/codegen/sret-aliasing-rules.rs
new file mode 100644
index 00000000000..f35e722f764
--- /dev/null
+++ b/tests/ui/codegen/sret-aliasing-rules.rs
@@ -0,0 +1,28 @@
+//! Check that functions with sret results don't violate aliasing rules.
+//!
+//! When `foo = func(&mut foo)` is called, the compiler must avoid creating
+//! two mutable references to the same variable simultaneously (one for the
+//! parameter and one for the hidden sret out-pointer).
+//!
+//! Regression test for <https://github.com/rust-lang/rust/pull/18250>.
+
+//@ run-pass
+
+#[derive(Copy, Clone)]
+pub struct Foo {
+    f1: isize,
+    _f2: isize,
+}
+
+#[inline(never)]
+pub fn foo(f: &mut Foo) -> Foo {
+    let ret = *f;
+    f.f1 = 0;
+    ret
+}
+
+pub fn main() {
+    let mut f = Foo { f1: 8, _f2: 9 };
+    f = foo(&mut f);
+    assert_eq!(f.f1, 8);
+}