[PATCH] checkpatch: Allow users to specify the python command to use

[Palmer Dabbelt]

From: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>

checkpatch.pl invokes spdxcheck.py using "python".  On my system that's
Python 2, but I only have a git package for Python 3.  This patch adds a
"--python=..." argument to checkpatch.pl that allows users to specify a
command to invoke Python.  I've just given this a little smoke test:
running it without any arguments still works, and running with
--python=python3 finds the git module.

Signed-off-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>

---
I'd considered reading some sort of environment variable, but searching
for "getenv" in checkpatch.pl didn't reveal any other enviornment
variables so I figured it'd be cleaner to avoid adding one.  I only
invoke checkpatch.pl from wrapper scripts anyway, so it's the same for
me.
---
 scripts/checkpatch.pl | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index d64c67b67e3c..05ce52a2aaa9 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -65,6 +65,7 @@ my $allow_c99_comments = 1; # Can be overridden by --ignore C99_COMMENT_TOLERANC
 # git output parsing needs US English output, so first set backtick child process LANGUAGE
 my $git_command ='export LANGUAGE=en_US.UTF-8; git';
 my $tabsize = 8;
+my $python = "python";
 
 sub help {
 	my ($exitcode) = @_;
@@ -125,6 +126,7 @@ Options:
   --typedefsfile             Read additional types from this file
   --color[=WHEN]             Use colors 'always', 'never', or only when output
                              is a terminal ('auto'). Default is 'auto'.
+  --python=COMMAND           Use the give command to invoke python.
   -h, --help, --version      display this help and exit
 
 When FILE is - read standard input.
@@ -233,6 +235,7 @@ GetOptions(
 	'color=s'	=> \$color,
 	'no-color'	=> \$color,	#keep old behaviors of -nocolor
 	'nocolor'	=> \$color,	#keep old behaviors of -nocolor
+	'python=s'      => \$python,
 	'h|help'	=> \$help,
 	'version'	=> \$help
 ) or help(1);
@@ -897,10 +900,10 @@ sub is_maintained_obsolete {
 sub is_SPDX_License_valid {
 	my ($license) = @_;
 
-	return 1 if (!$tree || which("python") eq "" || !(-e "$root/scripts/spdxcheck.py") || !(-e "$root/.git"));
+	return 1 if (!$tree || which($python) eq "" || !(-e "$root/scripts/spdxcheck.py") || !(-e "$root/.git"));
 
 	my $root_path = abs_path($root);
-	my $status = `cd "$root_path"; echo "$license" | python scripts/spdxcheck.py -`;
+	my $status = `cd "$root_path"; echo "$license" | $python scripts/spdxcheck.py -`;
 	return 0 if ($status ne "");
 	return 1;
 }
-- 
2.26.1.301.g55bc3eb7cb9-goog