On Thu, Aug 06, 2020 at 07:58:06AM +0200, Markus Armbruster wrote: > Eduardo Habkost <[email protected]> writes: > > > On Wed, Aug 05, 2020 at 09:41:25PM +0100, Peter Maydell wrote: > >> On Wed, 5 Aug 2020 at 20:49, Eduardo Habkost <[email protected]> wrote: > >> > > >> > The struct had a single field (IDEDevice dev), and is only used > >> > in the QOM type declarations and property lists. We can simply > >> > use the IDEDevice struct directly instead. > >> > > >> > Signed-off-by: Eduardo Habkost <[email protected]> > >> > @@ -327,7 +323,6 @@ static void ide_hd_class_init(ObjectClass *klass, > >> > void *data) > >> > static const TypeInfo ide_hd_info = { > >> > .name = "ide-hd", > >> > .parent = TYPE_IDE_DEVICE, > >> > - .instance_size = sizeof(IDEDrive), > >> > .class_init = ide_hd_class_init, > >> > }; > >> > >> This is one of those areas where this change works and reduces > >> amount of code, but on the other hand it means the QOM type > >> doesn't follow the common pattern for a leaf type of: > >> * it has a struct > >> * it has cast macros that cast to that struct > >> * the typeinfo instance_size is the size of that struct > >> (it wasn't exactly following this pattern before, of course). > > > > Is this really a pattern that exists and we want to follow? > > I don't see why that pattern would be useful for simple leaf > > types. > > I think the pattern exists, but we deviate from it in quite a few > places, probably just because it's so much boilerplate. > > Related: Daniel's "[PATCH 0/4] qom: reduce boilerplate required for > declaring and defining objects". Perhaps Daniel has an opinion on > taking shortcuts with leaf types.
I think following a consistent pattern everywhere is important, because people look at existing code to guide their new code. The boilerplate pain is very real, but I think my patch series you point to will reduce the burden sufficiently that the kind of optimization proposed here is not required. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
