Markus Armbruster <arm...@redhat.com> writes:
> Markus Armbruster <arm...@redhat.com> writes:
>
>> Eric Blake <ebl...@redhat.com> writes:
>>
>>> Now that we elide unnecessary visits of empty types, we can
>>> start using the special ':empty' type in more places. By using
>>> the empty type as the base class of every explicit struct or
>>> union, and as the default data for any command or event, we can
>>> simplify later logic in qapi-{visit,commands,event} by merely
>>> checking whether the type is empty, without also having to worry
>>> whether a type was even supplied.
You rewrite a command's arg_type from None to ':empty', bit not its
ret_type. Deepens the assymmetry between the two.
>>> Note that gen_object() in qapi-types still has to check for a
>>> base, because it is also called for alternates (which have no
>>> base).
>>
>> What about the one in gen_visit_struct()?
>>
>> if (base and not base.is_empty()) or members:
>> ret += mcgen('''
>> visit_type_%(c_name)s_fields(v, obj, &err);
>> ''',
>> c_name=c_name(name))
>>
>>> No change to generated code.
>>>
>>> Signed-off-by: Eric Blake <ebl...@redhat.com>
>>>
>>> ---
>>> v9: squash in more related changes
>>> v8: rebase to earlier changes
>>> v7: rebase to earlier changes
>>> v6: new patch
>>> ---
>>> scripts/qapi-commands.py | 17 +++++++------
>>> scripts/qapi-event.py | 5 ++--
>>> scripts/qapi-types.py | 4 +--
>>> scripts/qapi-visit.py | 12 +++++----
>>> scripts/qapi.py | 25 +++++++++---------
>>> tests/qapi-schema/event-case.out | 2 +-
>>> tests/qapi-schema/flat-union-empty.out | 1 +
>>> tests/qapi-schema/ident-with-escape.out | 1 +
>>> tests/qapi-schema/indented-expr.out | 4 +--
>>> tests/qapi-schema/qapi-schema-test.out | 45
>>> ++++++++++++++++++++++++++++++---
>>> tests/qapi-schema/union-clash-data.out | 2 ++
>>> tests/qapi-schema/union-empty.out | 1 +
>>> 12 files changed, 83 insertions(+), 36 deletions(-)
>
> Missing: update to qapi-introspect.py. At least the expressions like
>
> arg_type or self._schema.the_empty_object_type
>
> need updating.
But so far not the ret_type or self._schema.the_empty_object_type.
[...]
