1 files changed, 33 insertions, 0 deletions
diff --git a/tests/codegen-llvm/addr-of-mutate.rs b/tests/codegen-llvm/addr-of-mutate.rs
new file mode 100644
index 00000000000..14bc4b8ab28
--- /dev/null
+++ b/tests/codegen-llvm/addr-of-mutate.rs
@@ -0,0 +1,33 @@
+//@ compile-flags: -C opt-level=3 -C no-prepopulate-passes
+
+#![crate_type = "lib"]
+
+// Test for the absence of `readonly` on the argument when it is mutated via `&raw const`.
+// See <https://github.com/rust-lang/rust/issues/111502>.
+
+// CHECK: i8 @foo(ptr noalias{{( nocapture)?}} noundef align 1{{( captures\(none\))?}} dereferenceable(128) %x)
+#[no_mangle]
+pub fn foo(x: [u8; 128]) -> u8 {
+    let ptr = core::ptr::addr_of!(x).cast_mut();
+    unsafe {
+        (*ptr)[0] = 1;
+    }
+    x[0]
+}
+
+// CHECK: i1 @second(ptr noalias{{( nocapture)?}} noundef align {{[0-9]+}}{{( captures\(none\))?}} dereferenceable({{[0-9]+}}) %a_ptr_and_b)
+#[no_mangle]
+pub unsafe fn second(a_ptr_and_b: (*mut (i32, bool), (i64, bool))) -> bool {
+    let b_bool_ptr = core::ptr::addr_of!(a_ptr_and_b.1.1).cast_mut();
+    (*b_bool_ptr) = true;
+    a_ptr_and_b.1.1
+}
+
+// If going through a deref (and there are no other mutating accesses), then `readonly` is fine.
+// CHECK: i1 @third(ptr noalias{{( nocapture)?}} noundef readonly align {{[0-9]+}}{{( captures\(none\))?}} dereferenceable({{[0-9]+}}) %a_ptr_and_b)
+#[no_mangle]
+pub unsafe fn third(a_ptr_and_b: (*mut (i32, bool), (i64, bool))) -> bool {
+    let b_bool_ptr = core::ptr::addr_of!((*a_ptr_and_b.0).1).cast_mut();
+    (*b_bool_ptr) = true;
+    a_ptr_and_b.1.1
+}