@@ -160,6 +160,7 @@ impl ObjectImpl for PL011State {
const INSTANCE_INIT: Option<unsafe fn(&mut Self)> = Some(Self::init);
const INSTANCE_POST_INIT: Option<fn(&Self)> = Some(Self::post_init);
+ const CLASS_INIT: fn(&mut Self::Class) = <Self as ClassInitImpl<Self::Class>>::class_init;
}
impl DeviceImpl for PL011State {
@@ -744,6 +745,8 @@ unsafe impl ObjectType for PL011Luminary {
impl ObjectImpl for PL011Luminary {
type ParentType = PL011State;
+
+ const CLASS_INIT: fn(&mut Self::Class) = <Self as ClassInitImpl<Self::Class>>::class_init;
}
impl DeviceImpl for PL011Luminary {}
@@ -21,7 +21,7 @@
},
prelude::*,
qdev::{DeviceImpl, DeviceMethods, DeviceState, Property, ResetType, ResettablePhasesImpl},
- qom::{ObjectImpl, ObjectType, ParentField},
+ qom::{ClassInitImpl, ObjectImpl, ObjectType, ParentField},
qom_isa,
sysbus::{SysBusDevice, SysBusDeviceImpl},
timer::{Timer, CLOCK_VIRTUAL},
@@ -836,6 +836,7 @@ impl ObjectImpl for HPETState {
const INSTANCE_INIT: Option<unsafe fn(&mut Self)> = Some(Self::init);
const INSTANCE_POST_INIT: Option<fn(&Self)> = Some(Self::post_init);
+ const CLASS_INIT: fn(&mut Self::Class) = <Self as ClassInitImpl<Self::Class>>::class_init;
}
// TODO: Make these properties user-configurable!
@@ -180,7 +180,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
T::INSTANCE_POST_INIT.unwrap()(unsafe { state.as_ref() });
}
-unsafe extern "C" fn rust_class_init<T: ObjectType + ClassInitImpl<T::Class>>(
+unsafe extern "C" fn rust_class_init<T: ObjectType + ObjectImpl>(
klass: *mut ObjectClass,
_data: *mut c_void,
) {
@@ -190,7 +190,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
// SAFETY: klass is a T::Class, since rust_class_init<T>
// is called from QOM core as the class_init function
// for class T
- T::class_init(unsafe { klass.as_mut() })
+ <T as ObjectImpl>::CLASS_INIT(unsafe { klass.as_mut() })
}
unsafe extern "C" fn drop_object<T: ObjectImpl>(obj: *mut Object) {
@@ -499,7 +499,7 @@ 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 + ClassInitImpl<Self::Class> + IsA<Object> {
+pub trait ObjectImpl: ObjectType + IsA<Object> {
/// The parent of the type. This should match the first field of the
/// struct that implements `ObjectImpl`, minus the `ParentField<_>` wrapper.
type ParentType: ObjectType;
@@ -552,6 +552,14 @@ pub trait ObjectImpl: ObjectType + ClassInitImpl<Self::Class> + IsA<Object> {
// methods on ObjectClass
const UNPARENT: Option<fn(&Self)> = None;
+
+ /// Store into the argument the virtual method implementations
+ /// for `Self`. On entry, the virtual method pointers are set to
+ /// the default values coming from the parent classes; the function
+ /// can change them to override virtual methods of a parent class.
+ ///
+ /// Usually defined as `<Self as ClassInitImpl<Self::Class>::class_init`.
+ const CLASS_INIT: fn(&mut Self::Class);
}
/// Internal trait used to automatically fill in a class struct.
@@ -60,6 +60,7 @@ unsafe impl ObjectType for DummyState {
impl ObjectImpl for DummyState {
type ParentType = DeviceState;
const ABSTRACT: bool = false;
+ const CLASS_INIT: fn(&mut DummyClass) = <Self as ClassInitImpl<DummyClass>>::class_init;
}
impl ResettablePhasesImpl for DummyState {}
@@ -102,6 +103,8 @@ unsafe impl ObjectType for DummyChildState {
impl ObjectImpl for DummyChildState {
type ParentType = DummyState;
const ABSTRACT: bool = false;
+ const CLASS_INIT: fn(&mut DummyChildClass) =
+ <Self as ClassInitImpl<DummyChildClass>>::class_init;
}
impl ResettablePhasesImpl for DummyChildState {}
As shown in the PL011 device, the orphan rules required a manual implementation of ClassInitImpl for anything not in the qemu_api crate; this gets in the way of moving system emulation-specific code (including DeviceClass, which as a blanket ClassInitImpl<DeviceClass> implementation) into its own crate. Make ClassInitImpl optional, at the cost of having to specify the CLASS_INIT member by hand in every implementation of ObjectImpl. The next commits will get rid of it, replacing all the "impl<T> ClassInitImpl<Class> for T" blocks with a generic class_init<T> method on Class. Right now the definition is always the same, but do not provide a default as that will not be true once ClassInitImpl goes away. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- rust/hw/char/pl011/src/device.rs | 3 +++ rust/hw/timer/hpet/src/hpet.rs | 3 ++- rust/qemu-api/src/qom.rs | 14 +++++++++++--- rust/qemu-api/tests/tests.rs | 3 +++ 4 files changed, 19 insertions(+), 4 deletions(-)