The patch titled
checkpatch: suggest using min_t or max_t
has been added to the -mm tree. Its filename is
checkpatch-suggest-using-min_t-or-max_t-v2.patch
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/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: checkpatch: suggest using min_t or max_t
From: Joe Perches <joe@xxxxxxxxxxx>
A common issue with min() or max() is using a cast on one or both of the
arguments when using min_t/max_t could be better.
Add cast detection to uses of min/max and suggest an appropriate use of
min_t or max_t instead.
Caveat: This only works for min() or max() on a single line.
It does not find min() or max() split across multiple lines.
This does find:
min((u32)foo, bar);
But it does not find:
max((unsigned long)foo,
bar);
Suggested-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
scripts/checkpatch.pl | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
diff -puN scripts/checkpatch.pl~checkpatch-suggest-using-min_t-or-max_t-v2 scripts/checkpatch.pl
--- a/scripts/checkpatch.pl~checkpatch-suggest-using-min_t-or-max_t-v2
+++ a/scripts/checkpatch.pl
@@ -268,6 +268,20 @@ sub build_types {
}
build_types();
+our $match_balanced_parentheses = qr/(\((?:[^\(\)]+|(-1))*\))/;
+
+our $Typecast = qr{\s*(\(\s*$NonptrType\s*\)){0,1}\s*};
+our $LvalOrFunc = qr{($Lval)\s*($match_balanced_parentheses{0,1})\s*};
+
+sub deparenthesize {
+ my ($string) = @_;
+ return "" if (!defined($string));
+ $string =~ s@^\s*\(\s*@@g;
+ $string =~ s@\s*\)\s*$@@g;
+ $string =~ s@\s+@ @g;
+ return $string;
+}
+
$chk_signoff = 0 if ($file);
my @dep_includes = ();
@@ -2285,6 +2299,27 @@ sub process {
}
}
+# typecasts on min/max could be min_t/max_t
+ if ($line =~ /^\+(?:.*?)\b(min|max)\s*\($Typecast{0,1}($LvalOrFunc)\s*,\s*$Typecast{0,1}($LvalOrFunc)\s*\)/) {
+ if (defined $2 || defined $8) {
+ my $call = $1;
+ my $cast1 = deparenthesize($2);
+ my $arg1 = $3;
+ my $cast2 = deparenthesize($8);
+ my $arg2 = $9;
+ my $cast;
+
+ if ($cast1 ne "" && $cast2 ne "") {
+ $cast = "$cast1 or $cast2";
+ } elsif ($cast1 ne "") {
+ $cast = $cast1;
+ } else {
+ $cast = $cast2;
+ }
+ WARN("$call() should probably be ${call}_t($cast, $arg1, $arg2)\n" . $herecurr);
+ }
+ }
+
# Need a space before open parenthesis after if, while etc
if ($line=~/\b(if|while|for|switch)\(/) {
ERROR("space required before the open parenthesis '('\n" . $herecurr);
_
Patches currently in -mm which might be from joe@xxxxxxxxxxx are
origin.patch
linux-next.patch
checkpatch-suggest-using-min_t-or-max_t-v2.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
