On Mon, Oct 25, 2021 at 07:25:24AM +0200, Markus Armbruster wrote: > By convention, names starting with "x-" are experimental. The parts > of external interfaces so named may be withdrawn or changed > incompatibly in future releases. > > Drawback: promoting something from experimental to stable involves a > name change. Client code needs to be updated. > > Moreover, the convention is not universally observed: > > * QOM type "input-barrier" has properties "x-origin", "y-origin". > Looks accidental, but it's ABI since 4.2. > > * QOM types "memory-backend-file", "memory-backend-memfd", > "memory-backend-ram", and "memory-backend-epc" have a property > "x-use-canonical-path-for-ramblock-id" that is documented to be > stable despite its name. Looks like there's another stable property with an "x-" prefix: "x-remote-object", part of QOM type @RemoteObjectProperties. Given the above "x-" properties are now stable, I take it that they cannot be renamed now, as they might break any tools using them? My guess is the tedious way is not worth it: deprecate them, and add the non-x variants as "synonyms". > We could document these exceptions, but documentation helps only > humans. We want to recognize "unstable" in code, like "deprecated". > > Replace the convention by a new special feature flag "unstable". It > will be recognized by the QAPI generator, like the existing feature > flag "deprecated", and unlike regular feature flags. FWIW, sounds good to me. > This commit updates documentation and prepares tests. The next commit > updates the QAPI schema. The remaining patches update the QAPI > generator and wire up -compat policy checking. > > Signed-off-by: Markus Armbruster <armbru@xxxxxxxxxx> > --- > docs/devel/qapi-code-gen.rst | 9 ++++++--- > tests/qapi-schema/qapi-schema-test.json | 7 +++++-- > tests/qapi-schema/qapi-schema-test.out | 5 +++++ > 3 files changed, 16 insertions(+), 5 deletions(-) [...] -- /kashyap
