Re: [PATCH] x86/raid6: correctly check for assembler capabilities

Valentin Rothberg
2015-02-03T21:24:52Z

On Tue, Feb 3, 2015 at 10:09 PM, NeilBrown <neilb@suse.de> wrote:
> On Tue, 03 Feb 2015 22:03:35 +0100 Paul Bolle <pebolle@tiscali.nl> wrote:
>
>> On Wed, 2015-02-04 at 07:50 +1100, NeilBrown wrote:
>> > Actually the prefix of this macro is "CONFIG_AS_", not "CONFIG_" :-)
>> > CONFIG_AS_ is reserved for assembly magic, and is never used by the the
>> > kconfig system.
>> >
>> > (Well..... I might have made bits of that up, but "git grep 'config AS_'"
>> > doesn't find anything).
>>
>> That's correct, there are no Kconfig symbols starting with AS_. But
>> still, I would like to hear whether there's a reasonable chance I might
>> convince other people to adopt my peeve.
>>
>> The thinking behind that peeve is, basically, that where people
>> encounter a CONFIG_* macro they should only have to check the .config
>> file to see how that macro was evaluated in the build that was used.
>>
>
> Personally, I don't care.

A problem with those identifiers is that the CONFIG_ prefix is
reserved for Kconfig features in Make and CPP syntax. The _MODULE
suffix for CPP alone. Sadly, this convention is only documented in
the Kconfig C code itself. Nonetheless, such cases give hard times to
static analysis tools that then have to deal with such false
positives.

Kind regards,
Valentin

> But I find that developers in general are more responsive to code than to
> peeves.
>
> So if you post a patch which makes the change that you want, then you are
> more likely to get a useful response than if you just post a peeve.
> It may not be the response you want of course....
>
> NeilBrown