diff options
Diffstat (limited to 'rust/qemu-api/src/definitions.rs')
| -rw-r--r-- | rust/qemu-api/src/definitions.rs | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/rust/qemu-api/src/definitions.rs b/rust/qemu-api/src/definitions.rs index 92b3c6f911..3291f4242c 100644 --- a/rust/qemu-api/src/definitions.rs +++ b/rust/qemu-api/src/definitions.rs @@ -20,8 +20,27 @@ pub trait ObjectImpl { const INSTANCE_FINALIZE: Option<unsafe extern "C" fn(obj: *mut Object)> = None; } -pub trait Class { +/// Trait used to fill in a class struct. +/// +/// Each QOM class that has virtual methods describes them in a +/// _class struct_. Class structs include a parent field corresponding +/// to the vtable of the parent class, all the way up to [`ObjectClass`]. +/// Each QOM type has one such class struct. +/// +/// The Rust implementation of methods will usually come from a trait +/// like [`ObjectImpl`]. +pub trait ClassInitImpl { + /// Function that is called after all parent class initialization + /// has occurred. 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. const CLASS_INIT: Option<unsafe extern "C" fn(klass: *mut ObjectClass, data: *mut c_void)>; + + /// Called on descendent classes after all parent class initialization + /// has occurred, but before the class itself is initialized. This + /// is only useful if a class is not a leaf, and can be used to undo + /// 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), >; @@ -82,8 +101,8 @@ macro_rules! type_info { instance_finalize: <$t as $crate::definitions::ObjectImpl>::INSTANCE_FINALIZE, abstract_: <$t as $crate::definitions::ObjectImpl>::ABSTRACT, class_size: ::core::mem::size_of::<<$t as $crate::definitions::ObjectImpl>::Class>(), - class_init: <<$t as $crate::definitions::ObjectImpl>::Class as $crate::definitions::Class>::CLASS_INIT, - class_base_init: <<$t as $crate::definitions::ObjectImpl>::Class as $crate::definitions::Class>::CLASS_BASE_INIT, + class_init: <<$t as $crate::definitions::ObjectImpl>::Class as $crate::definitions::ClassInitImpl>::CLASS_INIT, + class_base_init: <<$t as $crate::definitions::ObjectImpl>::Class as $crate::definitions::ClassInitImpl>::CLASS_BASE_INIT, class_data: ::core::ptr::null_mut(), interfaces: ::core::ptr::null_mut(), }; |