Re: [Qemu-devel] [PATCH qom-next] qom: make object cast assert if NULL object is passed as argument

[Markus Armbruster <armbru@redhat.com>]

Andreas Färber <afaerber@suse.de> writes:

> Am 01.06.2012 13:18, schrieb Markus Armbruster:
>> Andreas Färber <afaerber@suse.de> writes:
>> 
>>> Am 31.05.2012 13:17, schrieb Igor Mammedov:
>>>> On 05/31/2012 12:16 PM, Paolo Bonzini wrote:
>>>>> Il 31/05/2012 10:30, Markus Armbruster ha scritto:
>>>>>>>> Makes much sense, but maybe it should be done in OBJECT() cast? Assert
>>>>>>>> when we do OBJECT(NULL).
>>>>>> In my opinion, OBJECT(p) where p is a null pointer is perfectly valid
>>>>>> and should yield a null pointer.
>>>>>
>>>>> Perhaps object_dynamic_cast and object_dynamic_cast_assert should do the
>>>>> same?
>>>>>
>>>>
>>>> or better object_dynamic_cast should return NULL if obj is NULL,
>>>> after all it's expected that it may return NULL
>>>
>>> That's what I was suggesting: I think that we should define "NULL is not
>>> of type TYPE_FOO" and thus have the ..._is_... functions return false,
>>> and have the ..._cast_assert assert.
>> 
>> Is it?
>
> See http://www.mail-archive.com/qemu-devel@nongnu.org/msg113922.html
>
>> Igor: object_dynamic_cast should return NULL if obj is NULL,
>> 
>> You: have the ..._cast_assert assert [on null argument, I presume]
>> 
>> Doesn't sound like the same suggestion to me :)
>
> I'll let you to your opinion. :) However, my opinion is that

My question isn't about a difference of opinions between us two.  It's
about Igor writing "X should do Y", and you replying "Yes, that's what I
was suggesting, X should do !Y".  There's a misunderstanding there, and
it could well be mine.  So I ask.

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