Auto merge of #152632 - JonathanBrouwer:rollup-hVWecYA, r=JonathanBrouwer

Rollup of 7 pull requests

Successful merges:

 - rust-lang/rust#152622 (Update GCC subtree)
 - rust-lang/rust#145024 (Optimize indexing slices and strs with inclusive ranges)
 - rust-lang/rust#151365 (UnsafePinned: implement opsem effects of UnsafeUnpin)
 - rust-lang/rust#152381 (Do not require `'static` for obtaining reflection information.)
 - rust-lang/rust#143575 (Remove named lifetimes in some `PartialOrd` & `PartialEq` `impl`s)
 - rust-lang/rust#152404 (tests: adapt align-offset.rs for InstCombine improvements in LLVM 23)
 - rust-lang/rust#152582 (rustc_query_impl: Use `ControlFlow` in `visit_waiters` instead of nested options)

Author: bors

src/borrow_tracker/stacked_borrows/mod.rs

@@ -71,7 +71,9 @@ impl NewPermission {
                         access: None,
                         protector: None,
                     }
-                } else if pointee.is_unpin(*cx.tcx, cx.typing_env()) {
+                } else if pointee.is_unpin(*cx.tcx, cx.typing_env())
+                    && pointee.is_unsafe_unpin(*cx.tcx, cx.typing_env())
+                {
                     // A regular full mutable reference. On `FnEntry` this is `noalias` and `dereferenceable`.
                     NewPermission::Uniform {
                         perm: Permission::Unique,
@@ -129,7 +131,9 @@ impl NewPermission {
     fn from_box_ty<'tcx>(ty: Ty<'tcx>, kind: RetagKind, cx: &crate::MiriInterpCx<'tcx>) -> Self {
         // `ty` is not the `Box` but the field of the Box with this pointer (due to allocator handling).
         let pointee = ty.builtin_deref(true).unwrap();
-        if pointee.is_unpin(*cx.tcx, cx.typing_env()) {
+        if pointee.is_unpin(*cx.tcx, cx.typing_env())
+            && pointee.is_unsafe_unpin(*cx.tcx, cx.typing_env())
+        {
             // A regular box. On `FnEntry` this is `noalias`, but not `dereferenceable` (hence only
             // a weak protector).
             NewPermission::Uniform {

src/borrow_tracker/tree_borrows/mod.rs

@@ -133,7 +133,8 @@ impl<'tcx> NewPermission {
         retag_kind: RetagKind,
         cx: &crate::MiriInterpCx<'tcx>,
     ) -> Option<Self> {
-        let ty_is_unpin = pointee.is_unpin(*cx.tcx, cx.typing_env());
+        let ty_is_unpin = pointee.is_unpin(*cx.tcx, cx.typing_env())
+            && pointee.is_unsafe_unpin(*cx.tcx, cx.typing_env());
         let ty_is_freeze = pointee.is_freeze(*cx.tcx, cx.typing_env());
         let is_protected = retag_kind == RetagKind::FnEntry;
 

tests/pass/both_borrows/unsafe_pinned.rs

@@ -9,8 +9,36 @@ fn mutate(x: &UnsafePinned<i32>) {
     unsafe { ptr.write(42) };
 }
 
+fn mut_alias(x: &mut UnsafePinned<i32>, y: &mut UnsafePinned<i32>) {
+    unsafe {
+        x.get().write(0);
+        y.get().write(0);
+        x.get().write(0);
+        y.get().write(0);
+    }
+}
+
+// Also try this with a type for which we implement `Unpin`, just to be extra mean.
+struct MyUnsafePinned<T>(UnsafePinned<T>);
+impl<T> Unpin for MyUnsafePinned<T> {}
+
+fn my_mut_alias(x: &mut MyUnsafePinned<i32>, y: &mut MyUnsafePinned<i32>) {
+    unsafe {
+        x.0.get().write(0);
+        y.0.get().write(0);
+        x.0.get().write(0);
+        y.0.get().write(0);
+    }
+}
+
 fn main() {
-    let x = UnsafePinned::new(0);
+    let mut x = UnsafePinned::new(0i32);
     mutate(&x);
-    assert_eq!(x.into_inner(), 42);
+    assert_eq!(unsafe { x.get().read() }, 42);
+
+    let ptr = &raw mut x;
+    unsafe { mut_alias(&mut *ptr, &mut *ptr) };
+
+    let ptr = ptr.cast::<MyUnsafePinned<i32>>();
+    unsafe { my_mut_alias(&mut *ptr, &mut *ptr) };
 }