John Snow <js...@redhat.com> writes:
> I'm actually not too sure about this one, it seems to hold up at runtime
> but instead of lying and coming up with an elaborate ruse as a commit
> message I'm just going to admit I just cribbed my own notes from the
> last time I typed schema.py and I no longer remember why or if this is
> correct.
>
> Cool!
>
> With more seriousness, variants are only guaranteed to house a
> QAPISchemaType as per the definition of QAPISchemaObjectTypeMember but
> the only classes/types that have a check_clash method are descendents of
> QAPISchemaMember and the QAPISchemaVariants class itself.
>
> Signed-off-by: John Snow <js...@redhat.com>
> ---
> scripts/qapi/schema.py | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
> index 476b19aed61..ce5b01b3182 100644
> --- a/scripts/qapi/schema.py
> +++ b/scripts/qapi/schema.py
> @@ -717,6 +717,7 @@ def check_clash(self, info, seen):
> for v in self.variants:
> # Reset seen map for each variant, since qapi names from one
> # branch do not affect another branch
> + assert isinstance(v.type, QAPISchemaObjectType) # I think,
> anyway?
> v.type.check_clash(info, dict(seen))
Have a look at .check() right above:
def check(
self, schema: QAPISchema, seen: Dict[str, QAPISchemaMember]
) -> None:
[...]
if not self.variants:
raise QAPISemError(self.info, "union has no branches")
for v in self.variants:
v.check(schema)
# Union names must match enum values; alternate names are
# checked separately. Use 'seen' to tell the two apart.
if seen:
if v.name not in self.tag_member.type.member_names():
raise QAPISemError(
self.info,
"branch '%s' is not a value of %s"
% (v.name, self.tag_member.type.describe()))
---> if not isinstance(v.type, QAPISchemaObjectType):
---> raise QAPISemError(
self.info,
"%s cannot use %s"
% (v.describe(self.info), v.type.describe()))
v.type.check(schema)
Since .check() runs before .check_clash(), your assertion holds.
Clearer now?
