Re: [Qemu-arm] [Qemu-devel] QOM: best way for parents to pass information to children? (was Re: [PATCH RFC 07/16] qom/cpu: make nr-cores, nr-threads real properties)

[Paolo Bonzini]

On 19/07/2016 13:59, Eduardo Habkost wrote:
>>> > > If it's internal, do we have any reason to register a (writeable)
>>> > > property in the first place? Why not use a plain old
>>> > > "obj->field = value" C statement? Or, if a simple assignment
>>> > > isn't enough, why not a simple obj_set_field(value) C function?
>> > So that arch neutral code won't have to pull obj type definition
> 
> I don't get it. If arch neutral code uses it, it should be
> available in an arch-neutral header.

I agree.  If arch-neutral code uses it, the method should be in CPUClass.

Paolo

>> > and we would be able to reuse all machinery that uses properties
>> > instead of inventing yet another API or ad-hoc function calls.
> Why is adding a new C function or setting a struct field worse
> than adding a new property name? I actually prefer the former,
> because it makes code review easier and allows the compiler to
> detect more mistakes.