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

[Andreas Färber]

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.

So I still think this patch is correct. It could be accompanied by
further patches adding error handling in the remaining functions.

Andreas

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