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| author | Xining Xu <mac.xxn@outlook.com> | 2024-05-07 05:27:57 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-05-12 00:51:44 +0200 |
| commit | b1be5844c1a0124a49a30a20a189d0a53aa10578 (patch) | |
| tree | 1a3d6ee7f85d13832d9aaa9574c94dcba8903521 /scripts | |
| parent | Documentation: coding-style: ask function-like macros to evaluate parameters (diff) | |
| download | linux-b1be5844c1a0124a49a30a20a189d0a53aa10578.tar.xz linux-b1be5844c1a0124a49a30a20a189d0a53aa10578.zip | |
scripts: checkpatch: check unused parameters for function-like macro
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.
WARNING: Argument 'a' is not used in function-like macro
#21: FILE: mm/init-mm.c:20:
+#define test(a) do { } while (0)
total: 0 errors, 1 warnings, 8 lines checked
Link: https://lkml.kernel.org/r/20240507032757.146386-3-21cnbao@gmail.com
Signed-off-by: Xining Xu <mac.xxn@outlook.com>
Tested-by: Barry Song <v-songbaohua@oppo.com>
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Huacai Chen <chenhuacai@loongson.cn>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mark Brown <broonie@kernel.org>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Jeff Johnson <quic_jjohnson@quicinc.com>
Cc: Charlemagne Lasse <charlemagnelasse@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'scripts')
| -rwxr-xr-x | scripts/checkpatch.pl | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 9c4c4a61bc83..2b812210b412 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 |