[PATCH] checkpatch: get CONFIG_ prefix from the environment

[Jerome Forissier <jerome@forissier.org>]

Kconfig allows to customize the CONFIG_ prefix via the $CONFIG_
environment variable. Out-of-tree projects may therefore use Kconfig
with a different prefix, or they may use a custom configuration tool
which does not use the CONFIG_ prefix at all. Such projects may still
want to adhere to the Linux kernel coding style and run checkpatch.pl.
To make this possible, update checkpatch to use the value of $CONFIG_
if defined or "CONFIG_" otherwise.

Signed-off-by: Jerome Forissier <jerome@forissier.org>
---
 scripts/checkpatch.pl | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 2cbeae6d9aee..2cf750175a71 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 $CONFIG_ = $ENV{"CONFIG_"} || "CONFIG_";
 
 sub help {
 	my ($exitcode) = @_;
@@ -6528,16 +6529,16 @@ sub process {
 		}
 
 # check for IS_ENABLED() without CONFIG_<FOO> ($rawline for comments too)
-		if ($rawline =~ /\bIS_ENABLED\s*\(\s*(\w+)\s*\)/ && $1 !~ /^CONFIG_/) {
+		if ($rawline =~ /\bIS_ENABLED\s*\(\s*(\w+)\s*\)/ && $1 !~ /^$CONFIG_/) {
 			WARN("IS_ENABLED_CONFIG",
-			     "IS_ENABLED($1) is normally used as IS_ENABLED(CONFIG_$1)\n" . $herecurr);
+			     "IS_ENABLED($1) is normally used as IS_ENABLED($CONFIG_$1)\n" . $herecurr);
 		}
 
 # check for #if defined CONFIG_<FOO> || defined CONFIG_<FOO>_MODULE
-		if ($line =~ /^\+\s*#\s*if\s+defined(?:\s*\(?\s*|\s+)(CONFIG_[A-Z_]+)\s*\)?\s*\|\|\s*defined(?:\s*\(?\s*|\s+)\1_MODULE\s*\)?\s*$/) {
+		if ($line =~ /^\+\s*#\s*if\s+defined(?:\s*\(?\s*|\s+)($CONFIG_[A-Z_]+)\s*\)?\s*\|\|\s*defined(?:\s*\(?\s*|\s+)\1_MODULE\s*\)?\s*$/) {
 			my $config = $1;
 			if (WARN("PREFER_IS_ENABLED",
-				 "Prefer IS_ENABLED(<FOO>) to CONFIG_<FOO> || CONFIG_<FOO>_MODULE\n" . $herecurr) &&
+				 "Prefer IS_ENABLED(<FOO>) to $CONFIG_<FOO> || $CONFIG_<FOO>_MODULE\n" . $herecurr) &&
 			    $fix) {
 				$fixed[$fixlinenr] = "\+#if IS_ENABLED($config)";
 			}
-- 
2.25.1