1 files changed, 54 insertions, 0 deletions
diff --git a/src/test/ui/regions/regions-mock-codegen.rs b/src/test/ui/regions/regions-mock-codegen.rs
new file mode 100644
index 000000000..9d0ca76e4
--- /dev/null
+++ b/src/test/ui/regions/regions-mock-codegen.rs
@@ -0,0 +1,54 @@
+// run-pass
+#![allow(dead_code)]
+#![allow(non_camel_case_types)]
+// pretty-expanded FIXME #23616
+#![feature(allocator_api)]
+
+use std::alloc::{handle_alloc_error, Allocator, Global, Layout};
+use std::ptr::NonNull;
+
+struct arena(());
+
+struct Bcx<'a> {
+    fcx: &'a Fcx<'a>,
+}
+
+struct Fcx<'a> {
+    arena: &'a arena,
+    ccx: &'a Ccx,
+}
+
+struct Ccx {
+    x: isize,
+}
+
+fn allocate(_bcx: &arena) -> &Bcx<'_> {
+    unsafe {
+        let layout = Layout::new::<Bcx>();
+        let ptr = Global.allocate(layout).unwrap_or_else(|_| handle_alloc_error(layout));
+        &*(ptr.as_ptr() as *const _)
+    }
+}
+
+fn h<'a>(bcx: &'a Bcx<'a>) -> &'a Bcx<'a> {
+    return allocate(bcx.fcx.arena);
+}
+
+fn g(fcx: &Fcx) {
+    let bcx = Bcx { fcx };
+    let bcx2 = h(&bcx);
+    unsafe {
+        Global.deallocate(NonNull::new_unchecked(bcx2 as *const _ as *mut _), Layout::new::<Bcx>());
+    }
+}
+
+fn f(ccx: &Ccx) {
+    let a = arena(());
+    let fcx = Fcx { arena: &a, ccx };
+    return g(&fcx);
+}
+
+pub fn main() {
+    let ccx = Ccx { x: 0 };
+    f(&ccx);
+}