Eric Blake <ebl...@redhat.com> writes:
> On 08/05/2015 12:23 AM, Markus Armbruster wrote:
>> Eric Blake <ebl...@redhat.com> writes:
>>
>>> On 08/04/2015 09:57 AM, Markus Armbruster wrote:
>>>> The QAPI code generators work with a syntax tree (nested dictionaries)
>>>> plus a few symbol tables (also dictionaries) on the side.
>>>>
>
>>>> +class QAPISchemaArrayType(QAPISchemaType):
>>>> + def __init__(self, name, info, element_type):
>>>> + QAPISchemaType.__init__(self, name, info)
>>>> + assert isinstance(element_type, str)
>>>> + self.element_type_name = element_type
>>>> + self.element_type = None
>>>> + def check(self, schema):
>>>> + self.element_type = schema.lookup_type(self.element_type_name)
>>>> + assert self.element_type
>>>
>>> Is it worth adding:
>>>
>>> assert not isinstance(self.element_type, QAPISchemaArrayType)
>>>
>>> since we don't allow 2D arrays?
>>
>> If the generators actually rely on it, yes.
>
> Hmm. What happens if you do
> { 'command': 'Foo', 'returns': [ 'intList' ] }
>
>>
>> If it's just an arbitrary schema language restriction, probably no.
>
> That's a tough judgment call. We don't currently allow [ [ 'int' ] ],
> and the [ 'intList' ] hack is gross. On the other hand, I'm having a
> tough time coming up with technical reasons why we can't do it (arrays
> as a parameter or return type should work, and 2D arrays just add
> another layer of '*' to the C code).
Perhaps a quick experiment can decide the nature of the restriction.
>>>> + def _make_array_type(self, element_type):
>>>> + name = element_type + 'List'
>>>> + if not self.lookup_type(name):
>>>> + self._def_entity(QAPISchemaArrayType(name, None,
>>>> element_type))
>>>> + return name
>>>
>>> Hmm - we probably have collisions if a user tries to explicitly name a
>>> 'struct' or other type with a 'List' suffix. Not made worse by this
>>> patch and not an actual problem with any of our existing .json files, so
>>> we can save it for another day.
>>
>> qapi-code-gen.txt reserves the 'Kind' suffix.
>>
>> We should either adopt a sane, non-colliding scheme for generated names,
>> or prevent collisions by rejecting reserved names with a sane error
>> message (documenting them is then optional), or document reserved names.
>> The latter two require us to figure out what names we reserve. But as
>> you say, it's a task for another day.
>
> And that cleanup can worry about [ 'intList' ].
Yes.
