Am 07.08.2013 05:36, schrieb Alexey Kardashevskiy:
> This what I would suggest:
>
> #define OBJECT_GET_PARENT_CLASS(obj, name) \
> object_class_get_parent(OBJECT_GET_CLASS(ObjectClass, (obj), (name)))
>
> @name here is just to make sure we are at the right level of the class
> hierarchy.
>
> And use it like this:
>
> static void xics_kvm_cpu_setup(XICSState *icp, PowerPCCPU *cpu)
> {
> XICSStateClass *xsc = XICS_COMMON_CLASS(
> OBJECT_GET_PARENT_CLASS(OBJECT(icp), TYPE_KVM_XICS));
> ...
>
> Here both source and destination classes are checked, everyone must be happy
> :)
In addition to what Peter has explained, I recommend against using my
macro inline, just like we don't use OBJECT_CHECK() inline. Doing so
keeps the uses of TYPE_KVM_XICS together and lets us exchange the
implementation more easily should the need arise.
Btw COMMON_XICS_CLASS() would be a more specific name. (Yes, ARM GIC is
a counter-example.)
Andreas
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