[alsa-devel] [PATCH] ALSA: have snd_BUG_ON() always refer to arguments

[Mike Frysinger]

On Fri, Nov 7, 2008 at 02:15, Takashi Iwai wrote:
> At Fri, 7 Nov 2008 02:09:04 -0500,
> Mike Frysinger wrote:
>> On Fri, Nov 7, 2008 at 01:22, Takashi Iwai wrote:
>> > At Thu,  6 Nov 2008 21:05:21 -0500,
>> > Mike Frysinger wrote:
>> >> The snd_BUG_ON() macro should always expand its argument even if we're
>> >> forcing it to false.  This kills off unused warnings that did not exist
>> >> before the snd_assert() -> snd_BUG_ON() conversion.
>> >
>> > Andrew already change this differently.  Check with the latest version.
>>
>> what are you defining as "latest version" ?  i'm looking in torvalds
>> linux-2.6.git.
>
> git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6.git
>
>> > And which warning did you get actually?
>>
>> a few codecs define local vars which only get used in snd_BUG_ON() ...
>> so if snd_BUG_ON() doesnt utilize cond, gcc whines that the var is
>> unused.
>
> I know it.  But I thought all these were removed in the actual codes.
> I'd like to see the real warning messages.

seems the warnings where in codec drivers we havent pushed into
mainline yet.  regardless, i dont think auditing code and changing it
just to avoid (cond) references is the way to go.  it also breaks
valid C code if there were side effects in the (cond) as any other
macro which does not properly utilize every argument exactly once.
-mike