rust: qom: remove operations on &mut

The dubious casts of mutable references to objects are not used
anymore: the wrappers for qdev_init_clock_in and for IRQ and MMIO
initialization can be called directly on the subclasses, without
casts, plus they take a shared reference so they can just use
"upcast()" instead of "upcast_mut()".  Remove them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

3 files changed, 0 insertions, 89 deletions

diff --git a/rust/qemu-api/src/memory.rs b/rust/qemu-api/src/memory.rs
index eff9f09..fdb1ea1 100644
--- a/rust/qemu-api/src/memory.rs
+++ b/rust/qemu-api/src/memory.rs
@@ -175,11 +175,6 @@ impl MemoryRegion {
     ) {
         unsafe {
             Self::do_init_io(
-                // self.0.as_mut_ptr() needed because Rust tries to call
-                // ObjectDeref::as_mut_ptr() on "&mut Self", instead of coercing
-                // to "&Self" and then calling MemoryRegion::as_mut_ptr().
-                // Revisit if/when ObjectCastMut is not needed anymore; it is
-                // only used in a couple places for initialization.
                 self.0.as_mut_ptr(),
                 owner.cast::<Object>(),
                 &ops.0,
diff --git a/rust/qemu-api/src/prelude.rs b/rust/qemu-api/src/prelude.rs
index 634acf3..43bfcd5 100644
--- a/rust/qemu-api/src/prelude.rs
+++ b/rust/qemu-api/src/prelude.rs
@@ -17,7 +17,6 @@ pub use crate::qom::InterfaceType;
 pub use crate::qom::IsA;
 pub use crate::qom::Object;
 pub use crate::qom::ObjectCast;
-pub use crate::qom::ObjectCastMut;
 pub use crate::qom::ObjectDeref;
 pub use crate::qom::ObjectClassMethods;
 pub use crate::qom::ObjectMethods;
diff --git a/rust/qemu-api/src/qom.rs b/rust/qemu-api/src/qom.rs
index 2defbd2..34d7bc0 100644
--- a/rust/qemu-api/src/qom.rs
+++ b/rust/qemu-api/src/qom.rs
@@ -463,90 +463,7 @@ where
 impl<T: ObjectType> ObjectDeref for &T {}
 impl<T: ObjectType> ObjectCast for &T {}
 
-/// Trait for mutable type casting operations in the QOM hierarchy.
-///
-/// This trait provides the mutable counterparts to [`ObjectCast`]'s conversion
-/// functions. Unlike `ObjectCast`, this trait returns `Result` for fallible
-/// conversions to preserve the original smart pointer if the cast fails. This
-/// is necessary because mutable references cannot be copied, so a failed cast
-/// must return ownership of the original reference. For example:
-///
-/// ```ignore
-/// let mut dev = get_device();
-/// // If this fails, we need the original `dev` back to try something else
-/// match dev.dynamic_cast_mut::<FooDevice>() {
-///    Ok(foodev) => /* use foodev */,
-///    Err(dev) => /* still have ownership of dev */
-/// }
-/// ```
-pub trait ObjectCastMut: Sized + ObjectDeref + DerefMut
-where
-    Self::Target: ObjectType,
-{
-    /// Safely convert from a derived type to one of its parent types.
-    ///
-    /// This is always safe; the [`IsA`] trait provides static verification
-    /// that `Self` dereferences to `U` or a child of `U`.
-    fn upcast_mut<'a, U: ObjectType>(self) -> &'a mut U
-    where
-        Self::Target: IsA<U>,
-        Self: 'a,
-    {
-        // SAFETY: soundness is declared via IsA<U>, which is an unsafe trait
-        unsafe { self.unsafe_cast_mut::<U>() }
-    }
-
-    /// Attempt to convert to a derived type.
-    ///
-    /// Returns `Ok(..)` if the object is of type `U`, or `Err(self)` if the
-    /// object if the conversion failed. This is verified at runtime by
-    /// checking the object's type information.
-    fn downcast_mut<'a, U: IsA<Self::Target>>(self) -> Result<&'a mut U, Self>
-    where
-        Self: 'a,
-    {
-        self.dynamic_cast_mut::<U>()
-    }
-
-    /// Attempt to convert between any two types in the QOM hierarchy.
-    ///
-    /// Returns `Ok(..)` if the object is of type `U`, or `Err(self)` if the
-    /// object if the conversion failed. This is verified at runtime by
-    /// checking the object's type information.
-    fn dynamic_cast_mut<'a, U: ObjectType>(self) -> Result<&'a mut U, Self>
-    where
-        Self: 'a,
-    {
-        unsafe {
-            // SAFETY: upcasting to Object is always valid, and the
-            // return type is either NULL or the argument itself
-            let result: *mut U =
-                object_dynamic_cast(self.as_object_mut_ptr(), U::TYPE_NAME.as_ptr()).cast();
-
-            result.as_mut().ok_or(self)
-        }
-    }
-
-    /// Convert to any QOM type without verification.
-    ///
-    /// # Safety
-    ///
-    /// What safety? You need to know yourself that the cast is correct; only
-    /// use when performance is paramount.  It is still better than a raw
-    /// pointer `cast()`, which does not even check that you remain in the
-    /// realm of QOM `ObjectType`s.
-    ///
-    /// `unsafe_cast::<Object>()` is always safe.
-    unsafe fn unsafe_cast_mut<'a, U: ObjectType>(self) -> &'a mut U
-    where
-        Self: 'a,
-    {
-        unsafe { &mut *self.as_mut_ptr::<Self::Target>().cast::<U>() }
-    }
-}
-
 impl<T: ObjectType> ObjectDeref for &mut T {}
-impl<T: ObjectType> ObjectCastMut for &mut T {}
 
 /// Trait a type must implement to be registered with QEMU.
 pub trait ObjectImpl: ObjectType + IsA<Object> {