Re: [Qemu-devel] [PATCH for-2.9 v2] qom: Make all interface types abstract

[Eduardo Habkost]

On Wed, Dec 14, 2016 at 06:07:48PM +0100, Paolo Bonzini wrote:
> 
> 
> On 14/12/2016 14:48, Eduardo Habkost wrote:
> >> How do you find all abstract TypeInfo in the source?  The uninitiated
> >> might grep for .abstract = true, and be misled.  The initiated will be
> >> annoyed instead, because grepping for *absence* of .instance_size = is
> >> bothersome.
> >>
> >> I suspect life could be easier going forward if we instead required
> >> .abstract = true for interfaces, and enforced it with
> >> assert(ti->instance_size || ti->abstract) here.
> > I was doing that before deciding to change type_initialize(). I
> > think I still have the commit in my git reflog, I will recover it
> > and submit it as v3.
> 
> I think it's worse.
> 
> Interfaces are abstract by definition.  Requiring ".abstract = true"
> makes things less intuitive.  v2 seems good.

I don't think that making the type declaration more explicit
would cause any real problems, and it would help people grepping
the code. Anybody forgetting to add .abstract=true to new
interfaces would immediatly see an assertion error and would just
be annoyed for 1 minute.

I will submit v3 and let the maintainers decide.

-- 
Eduardo