Re: Possible false positive from checkpatch.pl

[Larry Finger <Larry.Finger@lwfinger.net>]

On 07/12/2010 01:28 PM, Joe Perches wrote:
> On Mon, 2010-07-12 at 12:52 -0500, Larry Finger wrote:
>> Andy,
>>
>> In preparing a vendor driver for submission to staging, I am getting the
>> following from checkpatch.pl:
>>
>> ERROR: Macros with multiple statements should be enclosed in a do - while loop
>> #377: FILE: staging/rtl8712/rtl871x_mp_ioctl.h:377:
>> +#define GEN_MP_IOCTL_HANDLER(sz, hdl, oid) {sz, hdl, oid},
>
> I think you should leave off the trailing comma from the macros
> and C99 might be better.  Maybe something like:
>
> (whatever the field names really are)
>
> #define GEN_MP_IOCTL_HANDLER(sz, hdl, oid)	\
> 	{.field1 = sz, .field2 = hdl, .field3 = oid}
>
>> ERROR: Macros with multiple statements should be enclosed in a do - while loop
>> #378: FILE: staging/rtl8712/rtl871x_mp_ioctl.h:378:
>> +#define EXT_MP_IOCTL_HANDLER(sz, subcode, oid) {sz,&mp_ioctl_ \
>> +       ## subcode ## _hdl, oid},
>
> The line continuation is rather ugly too.  Perhaps it's better as:
>
> #define EXT_MP_IOCTL_HANDLER(sz, subcode, oid)	\
> 	{.field1 = sz, .field2 =&mp_ioctl_##subcode##_hdl, .field3 = oid}
>
> They pass checkpatch without error.
>
> $ cat foo.h
> #define GEN_MP_IOCTL_HANDLER(sz, hdl, oid)	\
> 	{.field1 = sz, .field2 = hdl, .field3 = oid}
> #define EXT_MP_IOCTL_HANDLER(sz, subcode, oid)	\
> 	{.field1 = sz, .field2 =&mp_ioctl_##subcode##_hdl, .field3 = oid}
> $ ./scripts/checkpatch.pl -f foo.h
> total: 0 errors, 0 warnings, 4 lines checked
>
> foo.h has no obvious style problems and is ready for submission.

These are ugly macros that will be eliminated, but for the moment they are in 
the code. As I stated in my original email, removing the comma from the 
definition and adding it to the code does fix the checkpatch error, but it 
should not be necessary.

Larry