Am 23.11.2012 17:25, schrieb Paolo Bonzini:
> Il 23/11/2012 17:16, Andreas Färber ha scritto:
>>>> @@ -430,7 +430,7 @@ Object *object_dynamic_cast_assert(Object *obj, const
>>>> char *typename)
>>>>
>>>> inst = object_dynamic_cast(obj, typename);
>>>>
>>>> - if (!inst) {
>>>> + if (!inst && obj) {
>>>> fprintf(stderr, "Object %p is not an instance of type %s\n",
>>>> obj, typename);
>>>> abort();
>> This is followed by return inst;
>>
>> Since this function clearly has assert in the name I don't think this is
>> right. I would expect %p to print 0x0 and the function to abort.
>
> I think it's okay to segfault in this case.
>
> Otherwise you need to replace this simple cast+check pair:
>
> SCSIDevice *s = SCSI_DEVICE(some->long.expressio[n]);
> if (!s) {
> return;
> }
>
> with something that is more complex:
>
> DeviceState *d = some->long.expressio[n];
> SCSIDevice *s;
>
> if (!d) {
> return;
> }
> s = SCSI_DEVICE(d);
Right now our use of those macros guarantees that the result is never
NULL, so there are no such checks! That expectation is broken by your
patch - I'm guessing without reviewing all derived macros.
If having SCSI_BUS() return NULL was your intent you would not have
needed to switch to object_dynamic_cast in your second patch. :)
But let's leave it for Anthony to decide how he wants his macros to work. ;)
Andreas
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