On Mon, 24 Oct 2022 at 14:20, Markus Armbruster <arm...@redhat.com> wrote: > > Peter Maydell <peter.mayd...@linaro.org> writes: > > > On Mon, 24 Oct 2022 at 13:28, Markus Armbruster <arm...@redhat.com> wrote: > >> > >> Peter Maydell <peter.mayd...@linaro.org> writes: > >> > Markus: if we add a new value to the ShutdownCause enumeration, > >> > how annoying is it if we decide we don't want it later? I guess > >> > we can just leave it in the enum unused... (In this case we're > >> > using it for purely internal purposes and it won't ever actually > >> > wind up in any QMP events.) > >> > >> Deleting enumeration values is a compatibility issue only if the value > >> is usable in QMP input. > >> > >> "Purely internal" means it cannot occur in QMP output, and any attempt > >> to use it in input fails. Aside: feels a bit fragile. > > > > In this case there are as far as I can see no QMP input commands > > which use the enum at all -- it's only used in events, which are > > always output, I think. > > They are. > > Ascertaining "not used in QMP input" is pretty easy, and "not used in > CLI" isn't hard. My point is that uses could creep in later. This is > what makes "purely internal" fragile.
True. But otoh if there's a meaningful use of the enum constant in input in future we'll want to keep it around anyway. I guess what I'm asking is: do you specifically want this patch done some other way, or to require that "mark some values as internal-only" feature in the QAPI generator, or are you OK with it as-is? QMP/QAPI is your area, so your call... -- PMM
