[PATCH] Clarify error on directive in macro arguments (Re: [PATCH] jffs2: fix sparse errors: directive in argument list)

[Al Viro]

On Sun, Nov 17, 2013 at 06:15:32PM -0800, Joe Perches wrote:
> > > sparse matches gcc behaviour (I hope), but it warns about such abuses.
> > > It's a defect, all right - one being reported by sparse.
> > 
> > Perhaps the following tweak to the error message would make this
> > subtlety clearer?
> 
> Maybe, but this case isn't a macro.  It's a function.
> Dunno if differentiating when it's a macro or a
> function is difficult though.

In which case?  With printk() it's perfectly fine and sparse
will not complain at all.  With pr_info(), OTOH, we have
#define pr_info(fmt, ...) \
        printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
and when you start playing that kind of games with it, you get warnings.