Commit 831242ab authored by Aditya Srivastava's avatar Aditya Srivastava Committed by Linus Torvalds
Browse files

checkpatch: add fix and improve warning msg for non-standard signature 

Currently checkpatch warns for BAD_SIGN_OFF on non-standard signature
styles.

A large number of these warnings occur because of typo mistakes in
signature tags.  An evaluation over v4.13..v5.8 showed that out of 539
warnings due to non-standard signatures, 87 are due to typo mistakes.

Following are the standard signature tags which are often incorrectly
used, along with their individual counts of incorrect use (over
v4.13..v5.8):

 Reviewed-by: 42
 Signed-off-by: 25
 Reported-by: 6
 Acked-by: 4
 Tested-by: 4
 Suggested-by: 4

Provide a fix by calculating levenshtein distance for the signature tag
with all the standard signatures and suggest a fix with a signature, whose
edit distance is less than or equal to 2 with the misspelled signature.

Out of the 86 mispelled signatures fixed with this approach, 85 were found
to be good corrections and 1 was bad correction.

Following was found to be a bad correction:
 Tweeted-by (count: 1) => Tested-by

Link: https://lkml.kernel.org/r/20201128204333.7054-1-yashsri421@gmail.com


Signed-off-by: default avatarAditya Srivastava <yashsri421@gmail.com>
Acked-by: default avatarJoe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8e08f076

scripts/checkpatch.pl

+69 −2
Original line number Diff line number Diff line
@@ -506,6 +506,64 @@ our $signature_tags = qr{(?xi: 
	Cc:

)};



sub edit_distance_min {

	my (@arr) = @_;

	my $len = scalar @arr;

	if ((scalar @arr) < 1) {

		# if underflow, return

		return;

	}

	my $min = $arr[0];

	for my $i (0 .. ($len-1)) {

		if ($arr[$i] < $min) {

			$min = $arr[$i];

		}

	}

	return $min;

}



sub get_edit_distance {

	my ($str1, $str2) = @_;

	$str1 = lc($str1);

	$str2 = lc($str2);

	$str1 =~ s/-//g;

	$str2 =~ s/-//g;

	my $len1 = length($str1);

	my $len2 = length($str2);

	# two dimensional array storing minimum edit distance

	my @distance;

	for my $i (0 .. $len1) {

		for my $j (0 .. $len2) {

			if ($i == 0) {

				$distance[$i][$j] = $j;

			} elsif ($j == 0) {

				$distance[$i][$j] = $i;

			} elsif (substr($str1, $i-1, 1) eq substr($str2, $j-1, 1)) {

				$distance[$i][$j] = $distance[$i - 1][$j - 1];

			} else {

				my $dist1 = $distance[$i][$j - 1]; #insert distance

				my $dist2 = $distance[$i - 1][$j]; # remove

				my $dist3 = $distance[$i - 1][$j - 1]; #replace

				$distance[$i][$j] = 1 + edit_distance_min($dist1, $dist2, $dist3);

			}

		}

	}

	return $distance[$len1][$len2];

}



sub find_standard_signature {

	my ($sign_off) = @_;

	my @standard_signature_tags = (

		'Signed-off-by:', 'Co-developed-by:', 'Acked-by:', 'Tested-by:',

		'Reviewed-by:', 'Reported-by:', 'Suggested-by:'

	);

	foreach my $signature (@standard_signature_tags) {

		return $signature if (get_edit_distance($sign_off, $signature) <= 2);

	}



	return "";

}



our @typeListMisordered = (

	qr{char\s+(?:un)?signed},

	qr{int\s+(?:(?:un)?signed\s+)?short\s},
@@ -2773,8 +2831,17 @@ sub process { 
			my $ucfirst_sign_off = ucfirst(lc($sign_off));



			if ($sign_off !~ /$signature_tags/) {

				my $suggested_signature = find_standard_signature($sign_off);

				if ($suggested_signature eq "") {

					WARN("BAD_SIGN_OFF",

					     "Non-standard signature: $sign_off\n" . $herecurr);

				} else {

					if (WARN("BAD_SIGN_OFF",

						 "Non-standard signature: '$sign_off' - perhaps '$suggested_signature'?\n" . $herecurr) &&

					    $fix) {

						$fixed[$fixlinenr] =~ s/$sign_off/$suggested_signature/;

					}

				}

			}

			if (defined $space_before && $space_before ne "") {

				if (WARN("BAD_SIGN_OFF",