[PATCH 1/9] qapi: New special feature flag "unstable"

[Markus Armbruster]

John Snow <jsnow at redhat.com> writes:

> On Mon, Oct 25, 2021 at 1:26 AM Markus Armbruster <armbru at redhat.com> 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 of external interfaces so named may be withdrawn or changed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.
>>
>> 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.
>>
>> 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 at redhat.com>

[...]

> Feels odd to combine the doc update *and* test prep, but eh, whatever.

I admit this is what was left after patch splitting and reshuffling.

> Reviewed-by: John Snow <jsnow at redhat.com>

Thanks!