Re: [Qemu-devel] [PATCH for-4.0 v7 15/27] qapi: add an error in case a discriminator is conditional

[Markus Armbruster]

Two more nits...

Markus Armbruster <address@hidden> writes:

> Marc-André Lureau <address@hidden> writes:
>
>> Making a discriminator conditional doesn't make much sense.
>
> Good point (so easy to overlook!), but why first add the 'if' feature
> broken that way in PATCH 13, then fix it up in PATCH 15?
>
>>                                                             Instead,
>> the union could be made conditional.
>
> What do you mean by that?
>
>> Signed-off-by: Marc-André Lureau <address@hidden>
>> ---
>>  scripts/qapi/common.py                          |  8 ++++++++
>>  tests/Makefile.include                          |  1 +
>>  .../flat-union-invalid-if-discriminator.err     |  1 +
>>  .../flat-union-invalid-if-discriminator.exit    |  1 +
>>  .../flat-union-invalid-if-discriminator.json    | 17 +++++++++++++++++
>>  .../flat-union-invalid-if-discriminator.out     |  0
>>  6 files changed, 28 insertions(+)
>>  create mode 100644 tests/qapi-schema/flat-union-invalid-if-discriminator.err
>>  create mode 100644 
>> tests/qapi-schema/flat-union-invalid-if-discriminator.exit
>>  create mode 100644 
>> tests/qapi-schema/flat-union-invalid-if-discriminator.json
>>  create mode 100644 tests/qapi-schema/flat-union-invalid-if-discriminator.out
>>
>> diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py
>> index aec51acb07..f79b3fad54 100644
>> --- a/scripts/qapi/common.py
>> +++ b/scripts/qapi/common.py
>> @@ -578,6 +578,7 @@ def find_alternate_member_qtype(qapi_type):
>>  # Return the discriminator enum define if discriminator is specified as an
>>  # enum type, otherwise return None.
>>  def discriminator_find_enum_define(expr):
>> +    name = expr['union']

Dead assignment.

>>      base = expr.get('base')
>>      discriminator = expr.get('discriminator')
>>  
>> @@ -594,6 +595,7 @@ def discriminator_find_enum_define(expr):
>>  
>>      if isinstance(discriminator_value, dict):
>>          discriminator_value = discriminator_value['type']
>> +
>>      return enum_types.get(discriminator_value)
>>  
>>  
>
> These two hunks are leftovers, please drop.
>
>> @@ -800,7 +802,12 @@ def check_union(expr, info):
>>                                 "struct '%s'"
>>                                 % (discriminator, base))
>>          if isinstance(discriminator_value, dict):
>> +            if discriminator_value.get('if'):
>> +                raise QAPISemError(info, 'The discriminator %s.%s for union 
>> %s '

pycodestyle complains

    scripts/qapi/common.py:806:80: E501 line too long (80 > 79 characters)

>> +                                   'must not be conditional' %
>> +                                   (base, discriminator, name))
>>              discriminator_value = discriminator_value['type']
>> +
>>          enum_define = enum_types.get(discriminator_value)
>>          allow_metas = ['struct']
>>          # Do not allow string discriminator
>> @@ -1023,6 +1030,7 @@ def check_exprs(exprs):
>>  
>>          if 'include' in expr:
>>              continue
>> +        info = expr_elem['info']
>>          if 'union' in expr and not discriminator_find_enum_define(expr):
>>              name = '%sKind' % expr['union']
>>          elif 'alternate' in expr:
>> diff --git a/tests/Makefile.include b/tests/Makefile.include
>> index ea5d1e8787..3f5a1d0c30 100644
>> --- a/tests/Makefile.include
>> +++ b/tests/Makefile.include
>> @@ -409,6 +409,7 @@ qapi-schema += flat-union-inline-invalid-dict.json
>>  qapi-schema += flat-union-int-branch.json
>>  qapi-schema += flat-union-invalid-branch-key.json
>>  qapi-schema += flat-union-invalid-discriminator.json
>> +qapi-schema += flat-union-invalid-if-discriminator.json
>>  qapi-schema += flat-union-no-base.json
>>  qapi-schema += flat-union-optional-discriminator.json
>>  qapi-schema += flat-union-string-discriminator.json
>> diff --git a/tests/qapi-schema/flat-union-invalid-if-discriminator.err 
>> b/tests/qapi-schema/flat-union-invalid-if-discriminator.err
>> new file mode 100644
>> index 0000000000..0c94c9860d
>> --- /dev/null
>> +++ b/tests/qapi-schema/flat-union-invalid-if-discriminator.err
>> @@ -0,0 +1 @@
>> +tests/qapi-schema/flat-union-invalid-if-discriminator.json:13: The 
>> discriminator TestBase.enum1 for union TestUnion must not be conditional
>> diff --git a/tests/qapi-schema/flat-union-invalid-if-discriminator.exit 
>> b/tests/qapi-schema/flat-union-invalid-if-discriminator.exit
>> new file mode 100644
>> index 0000000000..d00491fd7e
>> --- /dev/null
>> +++ b/tests/qapi-schema/flat-union-invalid-if-discriminator.exit
>> @@ -0,0 +1 @@
>> +1
>> diff --git a/tests/qapi-schema/flat-union-invalid-if-discriminator.json 
>> b/tests/qapi-schema/flat-union-invalid-if-discriminator.json
>> new file mode 100644
>> index 0000000000..618ec36396
>> --- /dev/null
>> +++ b/tests/qapi-schema/flat-union-invalid-if-discriminator.json
>> @@ -0,0 +1,17 @@
>> +{ 'enum': 'TestEnum',
>> +  'data': [ 'value1', 'value2' ] }
>> +
>> +{ 'struct': 'TestBase',
>> +  'data': { 'enum1': { 'type': 'TestEnum', 'if': 'FOO' } } }
>> +
>> +{ 'struct': 'TestTypeA',
>> +  'data': { 'string': 'str' } }
>> +
>> +{ 'struct': 'TestTypeB',
>> +  'data': { 'integer': 'int' } }
>> +
>> +{ 'union': 'TestUnion',
>> +  'base': 'TestBase',
>> +  'discriminator': 'enum1',
>> +  'data': { 'value1': 'TestTypeA',
>> +            'value2': 'TestTypeB' } }
>> diff --git a/tests/qapi-schema/flat-union-invalid-if-discriminator.out 
>> b/tests/qapi-schema/flat-union-invalid-if-discriminator.out
>> new file mode 100644
>> index 0000000000..e69de29bb2
>
> Patch looks good otherwise.