From: Xining Xu <[email protected]>
If function-like macros do not utilize a parameter, it might result in a
build warning. In our coding style guidelines, we advocate for utilizing
static inline functions to replace such macros. This patch verifies
compliance with the new rule.
For a macro such as the one below,
#define test(a) do { } while (0)
The test result is as follows.
ERROR: Parameter 'a' is not used in function-like macro, please use static
inline instead
#21: FILE: mm/init-mm.c:20:
+#define test(a) do { } while (0)
total: 1 errors, 0 warnings, 8 lines checked
Signed-off-by: Xining Xu <[email protected]>
Tested-by: Barry Song <[email protected]>
Signed-off-by: Barry Song <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: Huacai Chen <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Andy Whitcroft <[email protected]>
Cc: Dwaipayan Ray <[email protected]>
Cc: Joe Perches <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Lukas Bulwahn <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Jeff Johnson <[email protected]>
Cc: Charlemagne Lasse <[email protected]>
---
scripts/checkpatch.pl | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 9c4c4a61bc83..9895d7e38a9f 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6040,6 +6040,12 @@ sub process {
CHK("MACRO_ARG_PRECEDENCE",
"Macro argument '$arg' may be
better as '($arg)' to avoid precedence issues\n" . "$herectx");
}
+
+# check if this is an unused argument
+ if ($define_stmt !~ /\b$arg\b/) {
+ WARN("MACRO_ARG_UNUSED",
+ "Argument '$arg' is not used in
function-like macro\n" . "$herectx");
+ }
}
# check for macros with flow control, but without ## concatenation
--
2.34.1
