On Thu, Jun 09, 2016 at 04:43:35PM +0200, Markus Armbruster wrote: > "Daniel P. Berrange" <berra...@redhat.com> writes: > > > The current -object command line syntax only allows for > > creation of objects with scalar properties, or a list > > with a fixed scalar element type. Objects which have > > properties that are represented as structs in the QAPI > > schema cannot be created using -object. > > > > This is a design limitation of the way the OptsVisitor > > is written. It simply iterates over the QemuOpts values > > as a flat list. The support for lists is enabled by > > allowing the same key to be repeated in the opts string. > > > > It is not practical to extend the OptsVisitor to support > > more complex data structures while also maintaining > > the existing list handling behaviour that is relied upon > > by other areas of QEMU. > > It should be practical to create a new option input visitor that parses > command line syntax straight into a QAPI visit, without the list magic, > and with fewer or no restrictions. Then we could start defining complex > command line arguments as QAPI types, parse them straight into generated > QAPI types, and dispense with the QDict wrangling.
Funnily enough I did actually start out trying to implement pretty much exactly that. I found that in my new opts visitor, I was essentially parsing the QemuOpts into QDict/QLists to handle the recursion from the visitor. At this point I was starting to duplicate much code from QDict and QmpInputVisitor, so it abandoned that approach and went for the more general QemuOpts -> QDict crumping instead, since it the goal to be achieved with simpler code overall. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
