From 5c04151c6cea29398b786b3fa781ec2f8f5ed1da Mon Sep 17 00:00:00 2001
From: Kevin Reid <kpreid@switchb.org>
Date: Sat, 21 Dec 2024 17:13:52 -0800
Subject: Implement `PointerLike` for `isize`, `NonNull`, `Cell`, `UnsafeCell`,
 and `SyncUnsafeCell`.

Implementing `PointerLike` for `UnsafeCell` enables the possibility of
interior mutable `dyn*` values. Since this means potentially exercising
new codegen behavior, I added a test for it in `tests/ui/dyn-star/cell.rs`.

Also updated UI tests to account for the `isize` implementation changing
error messages.
---
 tests/ui/dyn-star/cell.rs                  | 34 ++++++++++++++++++++++++++++++
 tests/ui/dyn-star/error.rs                 |  2 +-
 tests/ui/dyn-star/float-as-dyn-star.stderr |  4 +++-
 3 files changed, 38 insertions(+), 2 deletions(-)
 create mode 100644 tests/ui/dyn-star/cell.rs

(limited to 'tests')

diff --git a/tests/ui/dyn-star/cell.rs b/tests/ui/dyn-star/cell.rs
new file mode 100644
index 00000000000..f4c7927a39d
--- /dev/null
+++ b/tests/ui/dyn-star/cell.rs
@@ -0,0 +1,34 @@
+// This test with Cell also indirectly exercises UnsafeCell in dyn*.
+//
+//@ run-pass
+
+#![feature(dyn_star)]
+#![allow(incomplete_features)]
+
+use std::cell::Cell;
+
+trait Rw<T> {
+    fn read(&self) -> T;
+    fn write(&self, v: T);
+}
+
+impl<T: Copy> Rw<T> for Cell<T> {
+    fn read(&self) -> T {
+        self.get()
+    }
+    fn write(&self, v: T) {
+        self.set(v)
+    }
+}
+
+fn make_dyn_star() -> dyn* Rw<usize> {
+    Cell::new(42usize) as dyn* Rw<usize>
+}
+
+fn main() {
+    let x = make_dyn_star();
+
+    assert_eq!(x.read(), 42);
+    x.write(24);
+    assert_eq!(x.read(), 24);
+}
diff --git a/tests/ui/dyn-star/error.rs b/tests/ui/dyn-star/error.rs
index 7288596f3fa..1d252d2ce42 100644
--- a/tests/ui/dyn-star/error.rs
+++ b/tests/ui/dyn-star/error.rs
@@ -6,7 +6,7 @@ use std::fmt::Debug;
 trait Foo {}
 
 fn make_dyn_star() {
-    let i = 42;
+    let i = 42usize;
     let dyn_i: dyn* Foo = i; //~ ERROR trait bound `usize: Foo` is not satisfied
 }
 
diff --git a/tests/ui/dyn-star/float-as-dyn-star.stderr b/tests/ui/dyn-star/float-as-dyn-star.stderr
index 9caba512e5f..06071a27afc 100644
--- a/tests/ui/dyn-star/float-as-dyn-star.stderr
+++ b/tests/ui/dyn-star/float-as-dyn-star.stderr
@@ -14,7 +14,9 @@ LL |     f32::from_bits(0x1) as f64
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ `f64` needs to be a pointer-like type
    |
    = help: the trait `PointerLike` is not implemented for `f64`
-   = help: the trait `PointerLike` is implemented for `usize`
+   = help: the following other types implement trait `PointerLike`:
+             isize
+             usize
 
 error: aborting due to 1 previous error; 1 warning emitted
 
-- 
cgit 1.4.1-3-g733a5