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| author | Joe Perches <joe@perches.com> | 2014-12-10 15:51:46 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-10 17:41:11 -0800 |
| commit | abb08a53883ed7afbe3f0ac9444805042f473a63 (patch) | |
| tree | eed4ba0882422e17763c65ceef9ce66d11bf79bc | |
| parent | 36061e380618201a558e01d2c2ac6217ea331523 (diff) | |
| download | linux-abb08a53883ed7afbe3f0ac9444805042f473a63.tar.gz linux-abb08a53883ed7afbe3f0ac9444805042f473a63.tar.bz2 linux-abb08a53883ed7afbe3f0ac9444805042f473a63.zip | |
checkpatch: try to avoid mask and shift errors
Shift has a higher precedence that mask so warn when a mask then shift
operation is done without parentheses around the mask.
This test works well for a right shift, but the left shift is pretty
commonly done correctly so only warn on the right shift.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rwxr-xr-x | scripts/checkpatch.pl | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 853dc7f9f751..24d6702a95c2 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -4482,6 +4482,14 @@ sub process { } } +# check for mask then right shift without a parentheses + if ($^V && $^V ge 5.10.0 && + $line =~ /$LvalOrFunc\s*\&\s*($LvalOrFunc)\s*>>/ && + $4 !~ /^\&/) { # $LvalOrFunc may be &foo, ignore if so + WARN("MASK_THEN_SHIFT", + "Possible precedence defect with mask then right shift - may need parentheses\n" . $herecurr); + } + # check for bad placement of section $InitAttribute (e.g.: __initdata) if ($line =~ /(\b$InitAttribute\b)/) { my $attr = $1; |