Re: [Qemu-devel] [PATCH] Add assignment operation to config file parser..

john cooper
2010-02-08T16:09:44Z

Gerd Hoffmann wrote:
> On 02/07/10 17:24, Anthony Liguori wrote:
>> On 02/06/2010 12:59 PM, john cooper wrote:
>>> This patch reworks support for both assignment and
>>> append in the config file parser. It was motivated
>>> by comments received on the cpu model config file
>>> format.
>>>
>>> Commit dc9ca4ba27be4fe6a0284061b8f056c4364fb0d9
>>> changed the behavior of "=" from assign to append.
>>> This patch preserves the ability to append to an
>>> option (however now via "+="), reverts "=" to its
>>> previous behavior, and allows both to interoperate.
>>>
>>> Signed-off-by: john cooper<john.cooper@redhat.com>
>>
>> This deviates from standard ini syntax which makes me a big
>> uncomfortable with it. Gerd, do you have an opinion?
>
> Also it the syntax change will break existing users of the append
> feature (host/guestfwd for slirp networking).
>
> Any reason why you can't use the current append to avoid the overlong
> feature flag lines?

Impacting existing usage was my primary concern as well.
I'd run this by Mark who created the patch changing the
disposition of "=" to append and I didn't find any alarms
there.

The proposed scheme supports both semantics and arguably
seems more intuitive. If that is the general consensus
and it won't unduly perturb existing usage the above
would be opportune before the current behavior becomes
more entrenched (e.g. by further dependencies such as the
proposed cpu model configuration).

But to answer the question, my prior patch can work with
either.

Thanks,

-john