Re: [Qemu-devel] [PATCH v2 5/6] qapi: generate list struct and visit_list for enum

[Amos Kong <akong@redhat.com>]

On 07/06/12 08:26, Michael Roth wrote:
> On Wed, Jun 06, 2012 at 03:40:37PM -0300, Luiz Capitulino wrote:
>> On Sat,  2 Jun 2012 06:54:27 +0800
>> Amos Kong<akong@redhat.com>  wrote:
>>
>>> Currently, if define an 'enum' and use it in one command's data,
>>> List struct for enum could not be generated, but it's used in
>>> qmp function.
>>>
>>> For example: KeyCodesList could not be generated.
>>>>>> qapi-schema.json:
>>> { 'enum': 'KeyCodes',
>>>    'data': [ 'shift', 'alt' ... ] }
>>> { 'command': 'sendkey',
>>>    'data': { 'keys': ['KeyCodes'], '*hold-time': 'int' } }
>>>
>>>>>> qmp-command.h:
>>> void qmp_sendkey(KeyCodesList * keys, bool has_hold_time, int64_t
>>> hold_time, Error **errp);
>>>
>>> This patch makes qapi can generate List struct for enum.
>>
>> This patch does it the simple way, just like any type. It generates a enum list
>> type and the functions qapi_free_yourenum() and qapi_free_yourenumlist().
>
> Had a couple suggestions, but approach/patch seems reasonable to me.
>
>>
>> The qapi_free_yourenum() list ends up doing nothing, so it could be a good
>> idea to generate an empty body (also note that we're copying the argument's
>> value, this could bite us in the future).
>
> I think we can omit qapi_free_yourenum() completely. Humans will know
> not to free non-allocated types, and the generated marshallers
> don't use these interfaces.
>
>>
>> Another point I was wondering is that, all enums will end up having the
>> exact same code. So maybe we could generate a default int list and use it
>> for all enums. Not sure it's worth it though.
>
> Since it's generated code I don't think it's worth it, personally.
>
>>
>> Michael, Paolo, ideas?
>>
>> More review comments below.


Thanks for your review!

>>> Signed-off-by: Amos Kong<akong@redhat.com>
>>> ---
>>>   scripts/qapi-types.py |   33 +++++++++++++++++++++++++++++----
>>>   scripts/qapi-visit.py |   14 +++++++++-----
>>>   2 files changed, 38 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
>>> index 4a734f5..c9641fb 100644
>>> --- a/scripts/qapi-types.py
>>> +++ b/scripts/qapi-types.py
>>> @@ -16,17 +16,36 @@ import os
>>>   import getopt
>>>   import errno
>>>
>>> -def generate_fwd_struct(name, members):
>>> -    return mcgen('''
>>> +def generate_fwd_struct(name, members, enum=False):
>>
>> I think it's better to have generate_fwd_enum_struct().

I tried this before, too many duplicate codes would be introduced,
but it's more clear.

two functions need to be added
   qapi-types.py: def generate_fwd_enum_struct(name, members):
   qapi-visit.py: def generate_enum_declaration(name, members, 
genlist=True):

>>> +    ret = ""
>>> +    if not enum:
>>> +        ret += mcgen('''
>>>   typedef struct %(name)s %(name)s;
>>>
>>> +''',
>>> +                     name=name)
>>> +    ret += mcgen('''
>>>   typedef struct %(name)sList
>>>   {
>>> -    %(name)s *value;
>>> +''',
>>> +                     name=name)
>>> +    if enum:
>>> +        ret += mcgen('''
>>> +         %(name)s value;
>>> +''',
>>> +                     name=name)
>>> +    else:
>>> +        ret += mcgen('''
>>> +         %(name)s * value;
>>> +''',
>>> +                     name=name)
>>> +
>>> +    ret += mcgen('''
>>>       struct %(name)sList *next;
>>>   } %(name)sList;
>>>   ''',
>>>                    name=name)
>>> +    return ret
>>>
>>>   def generate_struct(structname, fieldname, members):
>>>       ret = mcgen('''
>>> @@ -265,7 +284,8 @@ for expr in exprs:
>>>       if expr.has_key('type'):
>>>           ret += generate_fwd_struct(expr['type'], expr['data'])
>>>       elif expr.has_key('enum'):
>>> -        ret += generate_enum(expr['enum'], expr['data'])
>>> +        ret += generate_enum(expr['enum'], expr['data']) + "\n"
>>
>> The new-line should be returned by generate_enum(). Same applies for the
>> occurrences below.


"\n" is used to add a blank line here.

>>> +        ret += generate_fwd_struct(expr['enum'], expr['data'], True)
>>>           fdef.write(generate_enum_lookup(expr['enum'], expr['data']))
>>>       elif expr.has_key('union'):
>>>           ret += generate_fwd_struct(expr['union'], expr['data']) + "\n"
>>> @@ -289,6 +309,11 @@ for expr in exprs:
>>>           fdef.write(generate_type_cleanup(expr['union'] + "List") + "\n")
>>>           ret += generate_type_cleanup_decl(expr['union'])
>>>           fdef.write(generate_type_cleanup(expr['union']) + "\n")
>>> +    elif expr.has_key('enum'):
>>> +        ret += generate_type_cleanup_decl(expr['enum'] + "List")
>>> +        fdef.write(generate_type_cleanup(expr['enum'] + "List") + "\n")
>>> +        ret += generate_type_cleanup_decl(expr['enum'])
>>> +        fdef.write(generate_type_cleanup(expr['enum']) + "\n")
>>>       else:
>>>           continue
>>>       fdecl.write(ret)
>>> diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
>>> index 8d4e94a..e44edfa 100644
>>> --- a/scripts/qapi-visit.py
>>> +++ b/scripts/qapi-visit.py
>>> @@ -81,7 +81,7 @@ end:
>>>   ''')
>>>       return ret
>>>
>>> -def generate_visit_list(name, members):
>>> +def generate_visit_list(name, members, enum=False):
>>>       return mcgen('''
>>>
>>>   void visit_type_%(name)sList(Visitor *m, %(name)sList ** obj, const char *name, Error **errp)
>>> @@ -160,12 +160,14 @@ end:
>>>
>>>       return ret
>>>
>>> -def generate_declaration(name, members, genlist=True):
>>> -    ret = mcgen('''
>>> +def generate_declaration(name, members, genlist=True, enum=False):
>>> +    ret = ""
>>> +    if not enum:
>>> +        ret = mcgen('''

>>>   void visit_type_%(name)s(Visitor *m, %(name)s ** obj, const char *name, Error **errp);
>>>   ''',
>>> -                name=name)
>>> +                    name=name)
>>
>> Why this change?


Indent of above "mcgen(" changes, make them aligned.

>>>
>>>       if genlist:
>>>           ret += mcgen('''
>>> @@ -293,10 +295,12 @@ for expr in exprs:
>>>           ret += generate_declaration(expr['union'], expr['data'])
>>>           fdecl.write(ret)
>>>       elif expr.has_key('enum'):
>>> -        ret = generate_visit_enum(expr['enum'], expr['data'])
>>> +        ret = generate_visit_list(expr['enum'], expr['data'], True)
>>> +        ret += generate_visit_enum(expr['enum'], expr['data'])
>>>           fdef.write(ret)
>>>
>>>           ret = generate_decl_enum(expr['enum'], expr['data'])
>>> +        ret += generate_declaration(expr['enum'], expr['data'], enum=True)
>>>           fdecl.write(ret)
>>>
>>>   fdecl.write('''
>>
>>

-- 
			Amos.