linux-kernel - Re: [PATCH v5] checkpatch: add fix and improve warning msg for non-standard signature

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Message-ID: <c2087e41b85c3d45f1d224373b36ecff88d80298.camel@perches.com>
Date:   Sat, 28 Nov 2020 11:12:59 -0800
From:   Joe Perches <joe@...ches.com>
To:     Aditya Srivastava <yashsri421@...il.com>
Cc:     lukas.bulwahn@...il.com, linux-kernel@...r.kernel.org,
        linux-kernel-mentees@...ts.linuxfoundation.org
Subject: Re: [PATCH v5] checkpatch: add fix and improve warning msg for
 non-standard signature

On Sun, 2020-11-29 at 00:05 +0530, Aditya Srivastava wrote:
> Currently checkpatch warns for BAD_SIGN_OFF on non-standard signature
> styles.

Seems OK, but here are some last trivial notes:

> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
[]
> +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:'

I would change this to the normal signatures:

	my @standard_signature_tags = (
		'Signed-off-by:', 'Co-developed-by:', 'Acked-by:', 'Tested-by:',
		'Reviewed-by:', 'Reported-by:', 'Suggested-by:'

> +	);
> +	my $standard_signature;
> +	my $min_edit_distance = 20; # setting default value

20 seems arbitrary, maybe (~0 << 1) ?

> +	my $edit_distance;

move this into the foreach (or maybe not use this at all)

> +	foreach (@standard_signature_tags) {

foreach style in this code uses foreach my $<something> and not $_

	foreach my $standard (@standard_signature_tags) {

> +		$edit_distance = get_edit_distance($sign_off, $_);

So:

		my $edit_distance = get_edit_distance($sign_off, $standard);

> +		if ($edit_distance < $min_edit_distance) {
> +			$min_edit_distance = $edit_distance;
> +			$standard_signature = $_;
> +		}
> +	}
> +        if ($min_edit_distance <= 2) {
> +		return ucfirst($standard_signature);

	return $standard;

Though maybe it's simpler to test in the loop if it's <= 2 as
the lowercase and dash strip is done inside get_edit_distance
so this seems rather simpler:

	foreach my $standard (@standard_signature_tags) {
		return $standard if (get_edit_distance($sign_off, $standard) <= 2);
	}

	return "";

> @@ -2773,8 +2839,17 @@ sub process {
>  			my $ucfirst_sign_off = ucfirst(lc($sign_off));
>  
> 
>  			if ($sign_off !~ /$signature_tags/) {
> -				WARN("BAD_SIGN_OFF",
> -				     "Non-standard signature: $sign_off\n" . $herecurr);
> +				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) &&

Please use consistent '' or nothing around signatures:

						"Non-standard signature: '$sign_off' - likely typo of '$suggested_signature'\n" . $herecurr) &&

> +					    $fix) {
> +						$fixed[$fixlinenr] =~ s/$sign_off/$suggested_signature/;
> +					}
> +				}
>  			}
>  			if (defined $space_before && $space_before ne "") {
>  				if (WARN("BAD_SIGN_OFF",