Re: [Qemu-devel] [PATCH v2] qom: Reject attempts to add a property that already exists

[Anthony Liguori <aliguori@us.ibm.com>]

Peter Maydell <peter.maydell@linaro.org> writes:

> Ping!

This is wrong.

Container properties are added by the user.  You will turn a gracefully
failure (during hotplug) into an abort().

Please limit this to static properties as they are not added by a user.

Regards,

Anthony Liguori

>
> -- PMM
>
> On 7 September 2012 14:55, Peter Maydell <peter.maydell@linaro.org> wrote:
>> Reject attempts to add a property to an object if one of
>> that name already exists. This is always a bug in the caller;
>> this is merely diagnosing it gracefully rather than behaving
>> oddly later.
>>
>> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
>> ---
>> Changes v1->v2:
>>  * use abort() rather than assert(0), as suggested by Paolo
>>  * make the diagnostic message a little more helpful by
>>    including the type name, and adding '' around names
>>  * the patches fixing bugs which this patch makes fatal errors
>>    have both now been committed to master, so there's no
>>    barrier to committing it now
>>
>>  qom/object.c |   13 ++++++++++++-
>>  1 file changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/qom/object.c b/qom/object.c
>> index e3e9242..3da4c0e 100644
>> --- a/qom/object.c
>> +++ b/qom/object.c
>> @@ -620,7 +620,18 @@ void object_property_add(Object *obj, const char *name, const char *type,
>>                           ObjectPropertyRelease *release,
>>                           void *opaque, Error **errp)
>>  {
>> -    ObjectProperty *prop = g_malloc0(sizeof(*prop));
>> +    ObjectProperty *prop;
>> +
>> +    QTAILQ_FOREACH(prop, &obj->properties, node) {
>> +        if (strcmp(prop->name, name) == 0) {
>> +            /* This is always a bug in the caller */
>> +            fprintf(stderr, "attempt to add duplicate property '%s'"
>> +                    " to object (type '%s')\n", name, object_get_typename(obj));
>> +            abort();
>> +        }
>> +    }
>> +
>> +    prop = g_malloc0(sizeof(*prop));
>>
>>      prop->name = g_strdup(name);
>>      prop->type = g_strdup(type);
>> --
>> 1.7.9.5
>>
>>