Re: [PATCH v2] ip_tunnel: enclose a code block in macro IS_ENABLED(CONFIG_IPV6)

[David Miller]

From: äæå <yanhaishuang@xxxxxxxxxxxxxxxxxxxx>
Date: Tue, 24 May 2016 11:55:31 +0800

> 
>> On May 24, 2016, at 11:14 AM, Eric Dumazet <eric.dumazet@xxxxxxxxx> wrote:
>> 
>> On Tue, 2016-05-24 at 10:39 +0800, Haishuang Yan wrote:
>>> For ipv6 case, enclose the code block in macro IS_ENABLED(CONFIG_IPV6).
>>> 
>>> ---
>>> Changes in v2:
>>>  - Place the "#if IS_ENABLED" block before the "} else if
>>> (..) {" piece and the "#endif" before the closing brace and this
>>> becomes much easier to look at.
>> 
>> _Why_ is this patch needed ?
>> 
>> Please describe in the changelog what _actual_ problem you are trying to
>> address.
>> 
>> We have many points in the kernel using ipv6_get_dsfield() even if
>> CONFIG_IPV6=n, and it seems fine to me at least.
>> 
>> Thanks.
>> 
>> 
>> 
> 
> Yes, youâre right, but I think add this patch seems more reasonable in coding.

No, it isn't more reasonable at all.

We have the backup implementations when CONFIG_IPV6 is disabled
_EXACTLY_ to avoid ifdef crap like this in C files.