[PATCH 40/63] checkpatch: dont warn about unused macro arg on empty body

[Jim Cromie]

we currently get:
  WARNING: Argument 'name' is not used in function-like macro
on:
  #define DRM_CLASSMAP_USE(name)  /* nothing here */

Following this advice is wrong here, and shouldn't be fixed by
ignoring args altogether; the macro should properly fail if invoked
with 0 or 2+ args.

cc: Andy Whitcroft <apw@xxxxxxxxxxxxx>
cc: Joe Perches <joe@xxxxxxxxxxx>
cc: Dwaipayan Ray <dwaipayanray1@xxxxxxxxx>
cc: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>
Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
 scripts/checkpatch.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 4a93b2ede8cd..8933bd30317c 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6046,7 +6046,7 @@ sub process {
 				}
 
 # check if this is an unused argument
-				if ($define_stmt !~ /\b$arg\b/) {
+				if ($define_stmt !~ /\b$arg\b/ && $define_stmt) {
 					WARN("MACRO_ARG_UNUSED",
 					     "Argument '$arg' is not used in function-like macro\n" . "$herectx");
 				}
-- 
2.48.1