Re: [Qemu-devel] [PATCH 01/17] qidl: add QEMU IDL processor

[Anthony Liguori]

On 06/11/2012 02:20 AM, Paolo Bonzini wrote:
> Il 11/06/2012 09:13, Andreas Färber ha scritto:
> > > > > > +The first step is to move your device struct definition to a header file.  This
> > > > > > +header file should only contain the struct definition and any preprocessor
> > > > > > +declarations you need to define the structure.  This header file will act as
> > > > > > +the source for the QC IDL compiler.
> > > >
> > > > I don't think this is a fantastic idea -- the device struct should be
> > > > private to the device, and having it in a standalone header file is
> > > > asking for users of the device to illicitly include it and access
> > > > internals that they shouldn't.
> > But that is exactly where realize is headed. PCIBus, a9mp_priv etc.
> > structs will need to be made public so that they can be embedded.
>
> I thought that was just a convenience choice, not a necessity.  The
> children objects could just as well be heap-allocated.

Objects need some sort of type signature publicly.  The question is whether 
that's a forward reference, a structure using PIMPL, or the full blown structure.

I really don't see the overwhelming need to keep structures private.  Being able 
to directly reference public members is extremely handy.

I'd rather we focus on modeling more devices in a proper fashion such that we 
better understand their interactions and then make a decision about whether 
devices ought to be fully private or not.

Regards,

Anthony Liguori

> Paolo