[PATCH] checkpatch: Add test for possible misuse of IS_ENABLED() without CONFIG_

[Joe Perches <joe@perches.com>]

IS_ENABLED is almost always used with CONFIG_<FOO> defines.

Add a test to verify that the #define being tested starts with CONFIG_.

Signed-off-by: Joe Perches <joe@perches.com>
---
 scripts/checkpatch.pl | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 5f00df2c3f59..83be88b16166 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6480,6 +6480,12 @@ sub process {
 			}
 		}
 
+# check for IS_ENABLED() without CONFIG_<FOO> ($rawline for comments too)
+		if ($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" . $herecurr);
+		}
+
 # check for #if defined CONFIG_<FOO> || defined CONFIG_<FOO>_MODULE
 		if ($line =~ /^\+\s*#\s*if\s+defined(?:\s*\(?\s*|\s+)(CONFIG_[A-Z_]+)\s*\)?\s*\|\|\s*defined(?:\s*\(?\s*|\s+)\1_MODULE\s*\)?\s*$/) {
 			my $config = $1;