From: Xining Xu <ma.xxn@xxxxxxxxxxx>
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
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Chris Zankel <chris@xxxxxxxxxx>
Cc: Huacai Chen <chenhuacai@xxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Xining Xu <ma.xxn@xxxxxxxxxxx>
Tested-by: Barry Song <v-songbaohua@xxxxxxxx>
---
scripts/checkpatch.pl | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 9c4c4a61bc83..6f778f3403b5 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -6109,6 +6109,30 @@ sub process {
WARN("TRAILING_SEMICOLON",
"macros should not use a trailing semicolon\n" . "$herectx");
}
+
+ if ($dstat =~ /^\+\s*#\s*define\s+$Ident\s*(\((?:[^\(\)]++|(?-1))*\))\s+(\S+.*)(\/\/.*)?/) {
+ my $params = $1 || "";
+ my $body = $2 || "";
+
+ # get the individual params
+ $params =~ tr/()//d;
+ # remove leading and trailing whitespace
+ $params =~ s/^\s+|\s+$//g;
+
+ $ctx =~ s/\n*$//;
+ my $cnt = statement_rawlines($ctx);
+ my $herectx = get_stat_here($linenr, $cnt, $here);
+
+ if ($params ne "") {
+ my @paramList = split /,\s*/, $params;
+ foreach my $param(@paramList) {
+ if ($body !~ /\b$param\b/) {
+ ERROR("UNUSED_PARAM_IN_MACRO",
+ "Parameter '$param' is not used in function-like macro, please use static inline instead\n" . "$herectx");
+ }
+ }
+ }
+ }
}
# check for redundant bracing round if etc
--
2.34.1
