Re: [PATCH v8 1/2] checkpatch: Allow passing config directory
From: Joe Perches
Date: Tue Apr 21 2026 - 20:00:41 EST
On Tue, 2026-04-21 at 23:14 +0200, Petr Vorel wrote:
> checkpatch.pl searches for .checkpatch.conf in $CWD, $HOME and
> $CWD/.scripts. Allow passing a single directory via
> CHECKPATCH_CONFIG_DIR environment variable (empty value is ignored).
> This allows to directly use project configuration file for projects
> which vendored checkpatch.pl (e.g. LTP or u-boot).
>
> Although it'd be more convenient for user to have --conf-dir option
> (instead of using environment variable), code would get ugly because
> options from the configuration file needs to be read before processing
> command line options with Getopt::Long.
>
> While at it, document directories and environment variable in -h help
> and HTML doc.
>
> Signed-off-by: Petr Vorel <[pvorel@xxxxxxx](mailto:pvorel@xxxxxxx)>
Acked-by: Joe Perches <joe@xxxxxxxxxxx>
> ---
> Changes in v8 (sashiko):
> * Remove unintentional trailing space in regexp.
>
> Link to v7:
> [https://lore.kernel.org/lkml/20260421103851.508142-1-pvorel@xxxxxxx/](https://lore.kernel.org/lkml/20260421103851.508142-1-pvorel@xxxxxxx/)
>
> Link to v6:
> [https://lore.kernel.org/lkml/20260420133014.484162-1-pvorel@xxxxxxx/](https://lore.kernel.org/lkml/20260420133014.484162-1-pvorel@xxxxxxx/)
>
> Link to v5:
> [https://lore.kernel.org/lkml/20260417170346.448758-1-pvorel@xxxxxxx/](https://lore.kernel.org/lkml/20260417170346.448758-1-pvorel@xxxxxxx/)
>
> Link to v4:
> [https://lore.kernel.org/lkml/20260415143636.272605-1-pvorel@xxxxxxx/](https://lore.kernel.org/lkml/20260415143636.272605-1-pvorel@xxxxxxx/)
>
> Link to v3:
> [https://lore.kernel.org/lkml/20260408120603.54351-1-pvorel@xxxxxxx/](https://lore.kernel.org/lkml/20260408120603.54351-1-pvorel@xxxxxxx/)
>
> Link to v2:
> [https://lore.kernel.org/lkml/20260224181623.89904-1-pvorel@xxxxxxx/](https://lore.kernel.org/lkml/20260224181623.89904-1-pvorel@xxxxxxx/)
>
> Link to v1:
> [https://lore.kernel.org/lkml/20260202144221.76765-2-pvorel@xxxxxxx/](https://lore.kernel.org/lkml/20260202144221.76765-2-pvorel@xxxxxxx/)
>
> Documentation/dev-tools/checkpatch.rst | 7 +++++++
> scripts/checkpatch.pl | 20 +++++++++++++++++---
> 2 files changed, 24 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/dev-tools/checkpatch.rst b/Documentation/dev-tools/checkpatch.rst
> index dccede68698ca..010dfcd615afc 100644
> --- a/Documentation/dev-tools/checkpatch.rst
> +++ b/Documentation/dev-tools/checkpatch.rst
> @@ -210,6 +210,13 @@ Available options:
>
> Display the help text.
>
> +Configuration file
> +==================
> +
> +Default configuration options can be stored in ``.checkpatch.conf``, search
> +path: ``.:$HOME:.scripts`` or in a directory specified by ``$CHECKPATCH_CONFIG_DIR``
> +environment variable (falling back to the default search path).
> +
> Message Levels
> ==============
>
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 0492d6afc9a1f..8b44b3a6a4dd3 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -57,6 +57,9 @@ my %ignore_type = ();
> my @ignore = ();
> my $help = 0;
> my $configuration_file = ".checkpatch.conf";
> +my $def_configuration_dirs_help = '.:$HOME:.scripts';
> +(my $def_configuration_dirs = $def_configuration_dirs_help) =~ s/\$(\w+)/$ENV{$1}/g;
> +my $env_config_dir = 'CHECKPATCH_CONFIG_DIR';
> my $max_line_length = 100;
> my $ignore_perl_version = 0;
> my $minimum_perl_version = 5.10.0;
> @@ -146,6 +149,11 @@ Options:
> -h, --help, --version display this help and exit
>
> When FILE is - read standard input.
> +
> +CONFIGURATION FILE
> +Default configuration options can be stored in $configuration_file,
> +search path: '$def_configuration_dirs_help' or in a directory specified by
> +\$$env_config_dir environment variable (fallback to the default search path).
> EOM
>
> exit($exitcode);
> @@ -237,7 +245,7 @@ sub list_types {
> exit($exitcode);
> }
>
> -my $conf = which_conf($configuration_file);
> +my $conf = which_conf($configuration_file, $env_config_dir, $def_configuration_dirs);
> if (-f $conf) {
> my @conf_args;
> open(my $conffile, '<', "$conf")
> @@ -1531,9 +1539,15 @@ sub which {
> }
>
> sub which_conf {
> - my ($conf) = @_;
> + my ($conf, $env_key, $paths) = @_;
> + my $env_dir = $ENV{$env_key};
> +
> + if (defined($env_dir) && $env_dir ne "") {
> + return "$env_dir/$conf" if (-e "$env_dir/$conf");
> + warn "$P: Can't find a readable $conf in '$env_dir', falling back to default search paths\n";
> + }
>
> - foreach my $path (split(/:/, ".:$ENV{HOME}:.scripts")) {
> + foreach my $path (split(/:/, $paths)) {
> if (-e "$path/$conf") {
> return "$path/$conf";
> }
>