Re: Suspicious QOM types without instance/class size

[Eduardo Habkost <ehabkost@redhat.com>]

On Fri, Aug 21, 2020 at 11:43:35AM +0200, Cornelia Huck wrote:
> On Thu, 20 Aug 2020 17:55:29 -0400
> Eduardo Habkost <ehabkost@redhat.com> wrote:
> 
> > While trying to convert TypeInfo declarations to the new
> > OBJECT_DECLARE* macros, I've stumbled on a few suspicious cases
> > where instance_size or class_size is not set, despite having type
> > checker macros that use a specific type.
> > 
> > The ones with "WARNING" are abstract types (maybe not serious if
> > subclasses set the appropriate sizes).  The ones with "ERROR"
> > don't seem to be abstract types.
> > 
> > ERROR: hw/s390x/virtio-ccw.c:1237:1: class_size should be set to sizeof(VirtioCcwBusClass)?
> > ERROR: hw/virtio/virtio-pci.c:2101:1: class_size should be set to sizeof(VirtioPCIBusClass)?
> 
> VirtioCcwBusClass and VirtioPCIBusClass are both simple typedefs of
> VirtioBusClass (it's likely that I copied the ccw definition from the
> pci one). virtio-mmio instead uses VirtioBusClass directly in its
> checker macros.
> 
> I don't see a real reason for the typedefs, maybe ccw and pci should
> use the mmio approach as well?

I think it's OK to keep the typedefs if the code is consistent
(i.e. we set instance_size and class_size just in case the
typedefs are replaced by a real struct one day).

I'm not sure about the TYPE_VIRTIO_MMIO_BUS approach.  If the
code just needs VirtioBusState or VirtioBusClass pointers, it can
already use the VIRTIO_BUS* macros.

The OBJECT_DECLARE_TYPE macro Daniel sent expects each QOM type
to have a separate struct being defined, which isn't true in many
cases.  I'm considering removing the "typedef struct Foo Foo"
lines from OBJECT_DECLARE_TYPE(), to make initial conversion
easier.

-- 
Eduardo