On Tue, Oct 26, 2021 at 09:15:30AM +0200, Markus Armbruster wrote:
> Kashyap Chamarthy <kchamart@xxxxxxxxxx> writes:
>
> > On Mon, Oct 25, 2021 at 07:25:24AM +0200, Markus Armbruster wrote:
[...]
> > Looks like there's another stable property with an "x-" prefix:
> > "x-remote-object", part of QOM type @RemoteObjectProperties.
>
> The union branch 'x-remote-object' isn't flagged 'unstable' (because
> union branches can't have feature flags), but the enumeration value
> 'x-remote-object' is. Sufficient, because you can't use the branch
> without using the enumeration value. Admittedly subtle.
Ah, thanks for the explanation. I missed the union branch part, which
I now notice in your "[PATCH 2/9] qapi: Mark unstable QMP parts
with feature 'unstable'".
> I wrote a bit of code (appended) to make sure I don't miss names.
Thanks; looks good to me.
> > 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".
>
> "x-use-canonical-path-for-ramblock-id" goes back to commit fa0cb34d22
> "hostmem: use object id for memory region name with >= 4.0" (v4.0). It
> may have been intended to be internal back then. It wasn't anymore when
> commit 8db0b20415 "machine: add missing doc for memory-backend option"
> (v6.0) documented it:
>
> And document that x-use-canonical-path-for-ramblock-id,
> is considered to be stable to make sure it won't go away by accident.
>
> x- was intended for unstable/iternal properties, and not supposed to
> be stable option. However it's too late to rename (drop x-)
> it as it would mean that users will have to mantain both
> x-use-canonical-path-for-ramblock-id (for QEMU 5.0-5.2) versions
> and prefix-less for later versions.
>
> Igor's reasoning still applies.
>
> "x-origin" has always been stable. Same argument.
Yep, fair enough.
[...]
> commit 415b71a9f6e5bc37e84895d2e767cf4cfacd279b (HEAD)
> Author: Markus Armbruster <armbru@xxxxxxxxxx>
> Date: Sat Oct 9 09:01:21 2021 +0200
>
> qapi: Find x- without feature unstable DBG
>
> diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
> index b7b3fc0ce4..f2af1d7eea 100644
> --- a/scripts/qapi/schema.py
> +++ b/scripts/qapi/schema.py
> @@ -14,6 +14,8 @@
>
> # TODO catching name collisions in generated code would be nice
>
> +import sys
> +
> from collections import OrderedDict
> import os
> import re
> @@ -118,6 +120,11 @@ def describe(self):
> return "%s '%s'" % (self.meta, self.name)
>
>
> +def check_have_feature_unstable(name, info, features):
> + if name.startswith('x-') and 'unstable' not in (f.name for f in features):
> + print(QAPISemError(info, f"XXX %{name} %{features}"), file=sys.stderr)
> +
> +
> class QAPISchemaVisitor:
> def visit_begin(self, schema):
> pass
> @@ -718,6 +725,7 @@ def __init__(self, name, info, ifcond=None, features=None):
> self.features = features or []
>
> def connect_doc(self, doc):
> + check_have_feature_unstable(self.name, self.info, self.features)
> super().connect_doc(doc)
> if doc:
> for f in self.features:
> @@ -745,6 +753,7 @@ def __init__(self, name, info, typ, optional, ifcond=None, features=None):
> self.features = features or []
>
> def check(self, schema):
> + check_have_feature_unstable(self.name, self.info, self.features)
> assert self.defined_in
> self.type = schema.resolve_type(self._type_name, self.info,
> self.describe)
> @@ -789,6 +798,7 @@ def __init__(self, name, info, doc, ifcond, features,
>
> def check(self, schema):
> super().check(schema)
> + check_have_feature_unstable(self.name, self.info, self.features)
> if self._arg_type_name:
> self.arg_type = schema.resolve_type(
> self._arg_type_name, self.info, "command's 'data'")
> @@ -844,6 +854,7 @@ def __init__(self, name, info, doc, ifcond, features, arg_type, boxed):
>
> def check(self, schema):
> super().check(schema)
> + check_have_feature_unstable(self.name, self.info, self.features)
> if self._arg_type_name:
> self.arg_type = schema.resolve_type(
> self._arg_type_name, self.info, "event's 'data'")
TIL: the error class QAPISemError()
Reviewed-by: Kashyap Chamarthy <kchamart@xxxxxxxxxx>
--
/kashyap
