From: Andrew Morton <akpm@linux-foundation.org>
To: mm-commits@vger.kernel.org,v-songbaohua@oppo.com,sfr@canb.auug.org.au,quic_jjohnson@quicinc.com,lukas.bulwahn@gmail.com,linux@roeck-us.net,joe@perches.com,jcmvbkbc@gmail.com,herbert@gondor.apana.org.au,dwaipayanray1@gmail.com,corbet@lwn.net,chris@zankel.net,chenhuacai@loongson.cn,charlemagnelasse@gmail.com,broonie@kernel.org,apw@canonical.com,mac.xxn@outlook.com,akpm@linux-foundation.org
Subject: + scripts-checkpatch-check-unused-parameters-for-function-like-macro.patch added to mm-nonmm-unstable branch
Date: Tue, 07 May 2024 10:24:29 -0700 [thread overview]
Message-ID: <20240507172430.33195C4AF67@smtp.kernel.org> (raw)
The patch titled
Subject: scripts: checkpatch: check unused parameters for function-like macro
has been added to the -mm mm-nonmm-unstable branch. Its filename is
scripts-checkpatch-check-unused-parameters-for-function-like-macro.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/scripts-checkpatch-check-unused-parameters-for-function-like-macro.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Xining Xu <mac.xxn@outlook.com>
Subject: scripts: checkpatch: check unused parameters for function-like macro
Date: Tue, 7 May 2024 15:27:57 +1200
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>
---
Documentation/dev-tools/checkpatch.rst | 14 ++++++++++++++
scripts/checkpatch.pl | 6 ++++++
2 files changed, 20 insertions(+)
--- a/Documentation/dev-tools/checkpatch.rst~scripts-checkpatch-check-unused-parameters-for-function-like-macro
+++ a/Documentation/dev-tools/checkpatch.rst
@@ -906,6 +906,20 @@ Macros, Attributes and Symbols
See: https://lore.kernel.org/lkml/1399671106.2912.21.camel@joe-AO725/
+ **MACRO_ARG_UNUSED**
+ If function-like macros do not utilize a parameter, it might result
+ in a build warning. We advocate for utilizing static inline functions
+ to replace such macros.
+ For example, for a macro such as the one below::
+
+ #define test(a) do { } while (0)
+
+ there would be a warning like below::
+
+ WARNING: Argument 'a' is not used in function-like macro.
+
+ See: https://www.kernel.org/doc/html/latest/process/coding-style.html#macros-enums-and-rtl
+
**SINGLE_STATEMENT_DO_WHILE_MACRO**
For the multi-statement macros, it is necessary to use the do-while
loop to avoid unpredictable code paths. The do-while loop helps to
--- a/scripts/checkpatch.pl~scripts-checkpatch-check-unused-parameters-for-function-like-macro
+++ a/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
_
Patches currently in -mm which might be from mac.xxn@outlook.com are
scripts-checkpatch-check-unused-parameters-for-function-like-macro.patch
next reply other threads:[~2024-05-07 17:24 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 17:24 Andrew Morton [this message]
-- strict thread matches above, loose matches on Subject: below --
2024-03-22 19:06 + scripts-checkpatch-check-unused-parameters-for-function-like-macro.patch added to mm-nonmm-unstable branch Andrew Morton
2024-03-23 0:30 ` Joe Perches
2024-03-23 4:14 ` Barry Song
2024-03-23 6:16 ` Joe Perches
2024-03-23 22:40 ` Barry Song
2024-03-23 22:59 ` Joe Perches
2024-03-25 6:12 ` Barry Song
2024-03-25 9:43 ` Mac Xu
2024-03-25 10:16 ` Joe Perches
2024-03-26 0:38 ` Mac Xu
2024-03-24 0:32 ` Joe Perches
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240507172430.33195C4AF67@smtp.kernel.org \
--to=akpm@linux-foundation.org \
--cc=apw@canonical.com \
--cc=broonie@kernel.org \
--cc=charlemagnelasse@gmail.com \
--cc=chenhuacai@loongson.cn \
--cc=chris@zankel.net \
--cc=corbet@lwn.net \
--cc=dwaipayanray1@gmail.com \
--cc=herbert@gondor.apana.org.au \
--cc=jcmvbkbc@gmail.com \
--cc=joe@perches.com \
--cc=linux@roeck-us.net \
--cc=lukas.bulwahn@gmail.com \
--cc=mac.xxn@outlook.com \
--cc=mm-commits@vger.kernel.org \
--cc=quic_jjohnson@quicinc.com \
--cc=sfr@canb.auug.org.au \
--cc=v-songbaohua@oppo.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).