On 08/06/2013 06:33 PM, Andreas Färber wrote: > Am 06.08.2013 07:54, schrieb Alexey Kardashevskiy: >> On 08/01/2013 12:17 PM, Andreas Färber wrote: >>> The object argument is currently unused and may be used to optimize the >>> class lookup when needed. >>> >>> Inspired-by: Peter Crosthwaite <peter.crosthwa...@xilinx.com> >>> Signed-off-by: Andreas Färber <afaer...@suse.de> >>> --- >>> include/qom/object.h | 10 ++++++++++ >>> 1 file changed, 10 insertions(+) >>> >>> diff --git a/include/qom/object.h b/include/qom/object.h >>> index 23fc048..a8e71dc 100644 >>> --- a/include/qom/object.h >>> +++ b/include/qom/object.h >>> @@ -511,6 +511,16 @@ struct TypeInfo >>> OBJECT_CLASS_CHECK(class, object_get_class(OBJECT(obj)), name) >>> >>> /** >>> + * OBJECT_GET_PARENT_CLASS: >>> + * @obj: The object to obtain the parent class for. >>> + * @name: The QOM typename of @obj. >>> + * >>> + * Returns the parent class for a given object of a specific class. >>> + */ >>> +#define OBJECT_GET_PARENT_CLASS(obj, name) \ >>> + object_class_get_parent(object_class_by_name(name)) >>> + >>> +/** >>> * InterfaceInfo: >>> * @type: The name of the interface. >>> * >>> >> >> Has anyone ever tried to use this macro? > > Since you're asking me, obviously later in this virtio series it's used > and in the IndustryPack series as well. > > I'm not aware of anyone else having used it yet - I'm still waiting for > review feedback from Peter Cr. and/or Anthony (or you!) before I put it > on qom-next.
Still do not understand what "obj" is doing here. This what I would suggest: #define OBJECT_GET_PARENT_CLASS(obj, name) \ object_class_get_parent(OBJECT_GET_CLASS(ObjectClass, (obj), (name))) @name here is just to make sure we are at the right level of the class hierarchy. And use it like this: static void xics_kvm_cpu_setup(XICSState *icp, PowerPCCPU *cpu) { XICSStateClass *xsc = XICS_COMMON_CLASS( OBJECT_GET_PARENT_CLASS(OBJECT(icp), TYPE_KVM_XICS)); ... Here both source and destination classes are checked, everyone must be happy :) -- Alexey