# Re: \[PATCH 1/3\] checkpatch.pl: add missing memory barriers

- From: Joe Perches \<joe@perches.com\>
- Date: 2016-01-04 16:15:27 
- List: linux-arch
- Page: https://ratatoskr.run/linux-arch/2016/01/4652178
- Thread: https://ratatoskr.run/linux-arch/2016/01/4651968/t.md

```text
On Mon, 2016-01-04 at 16:11 +0000, Russell King - ARM Linux wrote:
> On Mon, Jan 04, 2016 at 08:07:40AM -0800, Joe Perches wrote:
> > On Mon, 2016-01-04 at 13:36 +0200, Michael S. Tsirkin wrote:
> > > +		my $all_barriers = join('|', (@barriers, @smp_barriers));
> > > +
> > > +		if ($line =~ /\b($all_barriers)\(/) {
> > 
> > It would be better to use /\b$all_barriers\s*\(/
> > as there's no reason for the capture and there
> > could be a space between the function and the
> > open parenthesis.
> 
> I think you mean
> 
> 	/\b(?:$all_barriers)\s*\(/
> 
> as 'all_barriers' will be:
> 
> 	mb|wmb|rmb|smp_mb|smp_wmb|smp_rmb
> 
> and putting that into your suggestion results in:
> 
> 	/\bmb|wmb|rmb|smp_mb|smp_wmb|smp_rmb\s*\(/
> 
> which is clearly wrong - the \b only applies to 'mb' and the \s*\( only
> applies to smp_rmb.

right, thanks.
```