Re: [PATCH v1] checkpatch: Add context-analysis attributes

[Vincent Donnefort <vdonnefort@google.com>]

On Sat, Nov 14, 2026 at 06:57:39AM -0800, Joe Perches wrote:
> On Sat, 2026-11-14 at 06:26 -0800, Joe Perches wrote:
> > > How about matching one internal () pair?
> > > 
> > > __guarded_by\s*\(
> > > 	(?:
> > > 		[^()]++ |
> > > 		\([^()]*+\)
> > > 	)*+
> > > \)
> > 
> > Sure.
> > Please add and use another variable so it's not repeated everywhere.
> 
> Reading a bit about balanced parentheses in perl '(?R)'
> non capturing recursion works since 5.10.0
> 
> Maybe instead use
> 
> /\((?:[^()]++|(?R))*\)/

Somehow it doesn't work. I have tried the following:

  my $p = qr/\((?:[^()]++|(?R))*\)/;
  my $a = qr/__guarded_by\s*$p/;
  for my $s ("__guarded_by(&mutex)", "__guarded_by(foobar())") {
  	print "$s:", ($s =~ /^$a$/ ? "ok" : "nope"), "\n";
  }'

  __guarded_by(&mutex): ok
  __guarded_by(foobar()): nope

Did I miss something?

-- 
Vincent

> 
> and I should probably rework all of checkpatch's uses of
> $balanced_parens to avoid all those weird capture group uses
> as it was originally written for perl 5.8 (thanks akpm)