Re: [Qemu-devel] [RFC 00/14]: add printf-like human msg to error_set()

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

Kevin Wolf <kwolf@redhat.com> writes:

> Am 26.07.2012 04:43, schrieb Anthony Liguori:
>> Luiz Capitulino <lcapitulino@redhat.com> writes:
>> 
>>> Basically, this series changes a call like:
>>>
>>>  error_set(errp, QERR_DEVICE_NOT_FOUND, device);
>>>
>>> to:
>>>
>>>  error_set(errp, QERR_DEVICE_NOT_FOUND,
>>>            "Device 'device=%s' not found", device);
>>>
>>> In the first call, QERR_DEVICE_NOT_FOUND is a string containing a json dict:
>>>
>>>     "{ 'class': 'DeviceNotFound', 'data': { 'device': %s } }"
>> 
>> This is the wrong direction.  Looking through the patch, this makes the
>> code much more redundant overall.  You have dozens of calls that are
>> duplicating the same error message.  This is not progress.
>
> I believe this is mostly because it's a mechanical conversion. Once this
> is done, we can change error messages to better fit the individual
> cases.

We don't gain anything by touching every user of error and the code gets
more verbose.  If we want to modify an existing error for some good
reason, we can do so my changing error types.

>> We should just stick with a simple QERR_GENERIC and call it a day.
>> Let's not needlessly complicate existing code.
>
> Why even have error codes when everything should become QERR_GENERIC? Or
> am I misunderstanding?

If we want to add an error code, we can do:

   error_set(QERR_GENERIC, "domain", "My free form text")

And then yes, we can change this to:

   error_setf(errp, "domain", "My free form text")

Or pick your favorite short name.

Regards,

Anthony Liguori

>
> Kevin