Re: [PATCH] kconfig: add kconfig-sym-check static checker

[Nathan Chancellor <nathan@kernel.org>]

On Sun, May 17, 2026 at 09:14:47AM +0300, Andy Shevchenko wrote:
> On Sun, May 17, 2026 at 01:26:07PM +0900, Nathan Chancellor wrote:
> > On Fri, May 15, 2026 at 09:08:07PM +0200, Nicolas Schier wrote:
> > > On Thu, May 14, 2026 at 10:32:12PM +0900, Nathan Chancellor wrote:
> > > > On Wed, 13 May 2026 16:03:29 -0500, Andrew Jones <andrew.jones@linux.dev> wrote:
> 
> [...]
> 
> > > > > diff --git a/scripts/kconfig/kconfig-sym-check.pl b/scripts/kconfig/kconfig-sym-check.pl
> > > > > new file mode 100755
> > > > > index 000000000000..a6907e585962
> > > > > --- /dev/null
> > > > > +++ b/scripts/kconfig/kconfig-sym-check.pl
> > > > > @@ -0,0 +1,93 @@
> > > > > +#!/usr/bin/env perl
> > > > > +# SPDX-License-Identifier: GPL-2.0
> > > > > +
> > > > > +use warnings;
> > > > > +use strict;
> > > > > +
> > > > > +my $kconfig_sym_check_excludes = undef;
> > > > > +$kconfig_sym_check_excludes = $ARGV[0] if (defined $ARGV[0]);
> > > > > +
> > > > > +my @files = `git ls-files '*Kconfig*'`;
> > > > 
> > > > What happens if you run this command on a release tarball? We should
> > > > probably use something like
> > > > 
> > > >   find $(srctree) -name '*Kconfig*'
> > > 
> > > not fully related, but that reminds me to this thread:
> > > https://lore.kernel.org/linux-kbuild/CAK7LNATJ-3JQ0QQGQ5R+R8aBJEq-tmBL8iBZrbM_4t0zeoYTaw@mail.gmail.com/#r
> > 
> > Ah yeah, that is definitely worth keeping in mind for the future. I feel
> > like 'find' is not "more complicated" than 'git ls-files' in this case,
> > so I will assume that such an objection would not really hold here
> > (especially since it would help people with development of fresh Kconfig
> > files that have not been committed yet). If we did want to rely on 'git
> > ls-files', we should at least error gracefully if we are not in a git
> > checkout.
> 
> Can we do both depending on the environment (if we are in Git, do that,
> otherwise fallback to `find`)? `find` uses FS, while Git uses index, which
> is much faster.

It feels like that starts to get into the complicated territory for
little gain, considering there is indeed a performance difference but I
am not sure that it is an obvious one in the grand scheme of things.

  $ hyperfine 'git ls-files "*Kconfig*"' 'find . -name "*Kconfig*"'
  Benchmark 1: git ls-files "*Kconfig*"
    Time (mean ± σ):      24.6 ms ±   1.0 ms    [User: 18.0 ms, System: 6.1 ms]
    Range (min … max):    20.5 ms …  28.7 ms    120 runs

  Benchmark 2: find . -name "*Kconfig*"
    Time (mean ± σ):     222.9 ms ±   4.5 ms    [User: 80.6 ms, System: 140.1 ms]
    Range (min … max):   216.0 ms … 227.6 ms    13 runs

  Summary
    git ls-files "*Kconfig*" ran
      9.06 ± 0.43 times faster than find . -name "*Kconfig*"

But I don't know how complicated such checking is in Perl, so I would be
willing to see what it looks like.

-- 
Cheers,
Nathan