Re: [PATCH v2 2/2] checkpatch: 3 use-cases for --debug rx=1 option

From: Joe Perches

Date: Sun Oct 26 2025 - 19:41:08 EST


On Sun, 2025-10-26 at 14:21 -0600, Jim Cromie wrote:
> Use the drx_print() helper in 3 cases inside code which counts macro
> arg expansions.
[]
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> @@ -6078,9 +6078,17 @@ sub process {
> next if ($arg =~ /\.\.\./);
> next if ($arg =~ /^type$/i);
> my $tmp_stmt = $define_stmt;
> - $tmp_stmt =~ s/\b(__must_be_array|offsetof|sizeof|sizeof_field|__stringify|typeof|__typeof__|__builtin\w+|typecheck\s*\(\s*$Type\s*,|\#+)\s*\(*\s*$arg\s*\)*\b//g;
> - $tmp_stmt =~ s/\#+\s*$arg\b//g;
> - $tmp_stmt =~ s/\b$arg\s*\#\#//g;
> +
> + $tmp_stmt =~ s/\#+\s*$arg\b/drx_print("'#|## arg' catenations")/ge;
> + $tmp_stmt =~ s/\b$arg\s*\#\#/drx_print("'arg ##' catenations");/ge;

stray trailing ; in the replacement ?

> + $tmp_stmt =~ s{
> + \b(__must_be_array|offsetof|sizeof|sizeof_field|
> + __stringify|typeof|__typeof__|__builtin\w+|
> + typecheck\s*\(\s*$Type\s*,|\#+)\s*\(*\s*$arg\s*\)*\b }

This might be easier to read using a qr but I'm not sure the
embedded capture groups and their use in drx_print is sensible
as it doesn't seem extensible.

our $stmt_stripper = qr{\b(
__must_be_array |
offsetof | typeof | __typeof__ |
sizeof | sizeof_field |
__builtin\w+
typecheck\s*\(\s*$Type\s*,|\#+)\s*\(*\s*$arg\s*\)\(*\s*$arg\s*\)*

> + {
> + drx_print("-arg-inspections-");
> + }xge;
> +
> my $use_cnt = () = $tmp_stmt =~ /\b$arg\b/g;
> if ($use_cnt > 1) {
> CHK("MACRO_ARG_REUSE",

Back with I suggested this a dozen years ago I thought it was overkill.
Maybe it is and the whole test should be offed.

https://lore.kernel.org/lkml/1352198139.16194.21.camel@joe-AO722/