On Fri, Mar 15, 2019 at 10:12:45AM -0500, Eric Blake wrote:
Checking that the derived class is larger than the requested parent class saves us from some obvious mistakes, but as written, it does not catch all the cases; in particular, it is easy to forget to update a VIR_CLASS_NEW when changing the 'parent' member from virObject to virObjectLockabale, but where the size checks don't catch that. Add a parameter for one more layer of sanity checking.
Note that I did NOT change the fact that we require derived classes to be larger (as the difference in size makes it easy to tell classes apart), which means that even if a derived class has no functionality to add (but rather exists for compiler-enforced type-safety), it must still include a dummy member. But I did fix the wording of the error message to match the code.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> 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 :|