Re: [PATCH] kobject: Suppress compiler warning with gcc 3.x

["Américo Wang" <xiyou.wangcong@gmail.com>]

On Wed, Jun 02, 2010 at 11:02:28PM -0700, Eric W. Biederman wrote:
>Américo Wang <xiyou.wangcong@gmail.com> writes:
>
>> On Thu, Jun 03, 2010 at 07:31:41AM +0200, Eric Dumazet wrote:
>>>Le jeudi 03 juin 2010 à 14:23 +0900, Tetsuo Handa a écrit :
>>>> Gcc 3.x generates a warning
>>>> 
>>>>   include/linux/sysfs.h:183: warning: parameter has incomplete type
>>>> 
>>>> on each file.
>>>> Suppress the warning by moving the definition of "enum kobj_ns_type"
>>>> to before "#include <linux/sysfs.h>".
>>>> 
>>>> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
>>>
>>>
>>>I was about to submit same patch, but I was also reverting 27eabc7cb4b3
>>>(sysfs: Don't use enums in inline function declaration.)
>>>
>>>So that sysfs_exit_ns() prototype is consistent regardless of
>>>CONFIG_SYSFS
>>>
>>>What do you think ?
>>>
>>
>> This looks odd, in sysfs.h we do have a forward declaration of
>> enum kobj_ns_type... I am wondering why gcc 3.x doesn't recognize it.
>
>Because the replacement is an inline, and we are passing the enum by value
>gcc wants to see the full definition, at the point where the inline function
>is declared.
>

But sysfs_exit_ns() is not inlined if CONFIG_SYSFS here.