Re: [Qemu-devel] [PATCH 27/28] sysbus: apic: ioapic: convert to QEMU Object Model

[Paolo Bonzini <pbonzini@redhat.com>]

On 01/25/2012 09:37 AM, Jan Kiszka wrote:
>> >  They're exactly the same size (16 lines).  If you embed TypeInfo into
>> >  DeviceTypeInfo, and introduce a Device specific type registration
>> >  function, then you could do:
>> >
>> >  static DeviceTypeInfo my_device_type_info = {
>> >       .type.name = TYPE_MY_DEVICE,
>> >       .type.parent = TYPE_PARENT_DEVICE,
>> >       .reset = my_device_reset,
> And if you introduce some
>
> #define TYPE_UNIMPLEMENTED (void *)&dummy_variable
>
> you can easily express
>
> [.field = NULL]         =>  use parent
>   .field = UNIMPLEMENTED =>  don't run any handler
>

I agree with Anthony, this would get really ugly where you are calling 
the functions and doing the class initialization.  It's a different 
style from what we're used to, granted, but the difference in code size 
is not relevant (not enough to introduce a level of macro magic, at 
least) and the diffstat in this series is misleading because qdev is 
left with temporary duplication for now.

(I also complained with him about this a month ago or so).

Paolo