Re: [PATCH 00/10] qom: Constify class_data

[Paolo Bonzini]

On 2/10/25 11:25, Philippe Mathieu-Daudé wrote:
> Following Richard's suggestion [*], make QOM class data *const*.
>
> Note, rust code not modified...

Untested but it should be something like

diff --git a/rust/qemu-api/src/qom.rs b/rust/qemu-api/src/qom.rs
index f36be2831eb..8603f7cc657 100644
--- a/rust/qemu-api/src/qom.rs
+++ b/rust/qemu-api/src/qom.rs
@@ -180,7 +180,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), 
fmt::Error> {
 
 unsafe extern "C" fn rust_class_init<T: ObjectType + ClassInitImpl<T::Class>>(
     klass: *mut ObjectClass,
-    _data: *mut c_void,
+    _data: *const c_void,
 ) {
     let mut klass = NonNull::new(klass)
         .unwrap()
@@ -523,7 +523,7 @@ pub trait ObjectImpl: ObjectType + 
ClassInitImpl<Self::Class> {
     /// the effects of copying the contents of the parent's class struct
     /// to the descendants.
     const CLASS_BASE_INIT: Option<
-        unsafe extern "C" fn(klass: *mut ObjectClass, data: *mut c_void),
+        unsafe extern "C" fn(klass: *mut ObjectClass, data: *const c_void),
     > = None;
 
     const TYPE_INFO: TypeInfo = TypeInfo {
@@ -544,7 +544,7 @@ pub trait ObjectImpl: ObjectType + 
ClassInitImpl<Self::Class> {
         class_size: core::mem::size_of::<Self::Class>(),
         class_init: Some(rust_class_init::<Self>),
         class_base_init: Self::CLASS_BASE_INIT,
-        class_data: core::ptr::null_mut(),
+        class_data: core::ptr::null(),
         interfaces: core::ptr::null_mut(),
     };


to be split across patches 8-10.

Paolo