Re: [PATCH v6] checkpatch: warn for non-standard fixes tag style

[Lukas Bulwahn]

On Sat, Sep 10, 2022 at 10:38 AM Niklas Söderlund
<niklas.soderlund@xxxxxxxxxxxx> wrote:
>
> Add a warning for fixes tags that does not fall in line with the
> standards specified by the community.
>
> Signed-off-by: Niklas Söderlund <niklas.soderlund@xxxxxxxxxxxx>
> Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
> Reviewed-by: Louis Peens <louis.peens@xxxxxxxxxxxx>
> ---
> * Changes since v5
> - Add support for --fix option for checkpatch.pl.
>
> * Changes since v4
> - Extend test to cover lines with whitespace before the fixes: tag, e.g.
>   match check on /^\s*fixes:?/i.
>
> * Changes since v3
> - Add test that title in tag match title of commit referenced by sha1.
>
> * Changes since v2
> - Change the pattern to match on 'fixes:?' to catch more malformed
>   tags.
>
> * Changes since v1
> - Update the documentation wording and add mention one cause of the
>   message can be that email program splits the tag over multiple lines.
> ---
>  Documentation/dev-tools/checkpatch.rst |  8 +++++
>  scripts/checkpatch.pl                  | 43 ++++++++++++++++++++++++++
>  2 files changed, 51 insertions(+)
>
> diff --git a/Documentation/dev-tools/checkpatch.rst b/Documentation/dev-tools/checkpatch.rst
> index b52452bc2963..8c8456a3bd18 100644
> --- a/Documentation/dev-tools/checkpatch.rst
> +++ b/Documentation/dev-tools/checkpatch.rst
> @@ -612,6 +612,14 @@ Commit message
>
>      See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes
>
> +  **BAD_FIXES_TAG**
> +    The Fixes: tag is malformed or does not fall in line with the standards
> +    specified by the community. This can occur if the tag have been split into
> +    multiple lines (e.g., when pasted in email program with word wrapping
> +    enabled).
> +
> +    See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes
> +

Thanks for all the work on checkpatch here!

Just three nits:

does not fall in line with ~~> how about "is not aligned with" or
"does not follow"?

"specified" and "standards" is a "big" word. Let us be more brief and
avoid "specification" and "standard".

"standards specified by the community" ~> "community standards", maybe
even "community conventions"?

"when pasted in email program" ~> "when pasted in an email program"

Maybe you also add a sentence on word wrapping of Fixes: tags, such as:

Note that the Fixes: tag line shall not be wrapped.

Nevertheless, for the documentation part:
Reviewed-by: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>
Acked-by: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>

Lukas

>
>  Comparison style
>  ----------------
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 79e759aac543..77f577535fc3 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -3140,6 +3140,49 @@ sub process {
>                         }
>                 }
>
> +# Check Fixes: styles is correct
> +               if (!$in_header_lines && $line =~ /^\s*fixes:?/i) {
> +                       my $orig_commit = "";
> +                       my $id = "0123456789ab";
> +                       my $title = "commit title";
> +                       my $tag_case = 1;
> +                       my $tag_space = 1;
> +                       my $id_length = 1;
> +                       my $id_case = 1;
> +                       my $title_has_quotes = 0;
> +
> +                       if ($line =~ /(\s*fixes:?)\s+([0-9a-f]{5,})\s+($balanced_parens)/i) {
> +                               my $tag = $1;
> +                               $orig_commit = $2;
> +                               $title = $3;
> +
> +                               $tag_case = 0 if $tag eq "Fixes:";
> +                               $tag_space = 0 if ($line =~ /^fixes:? [0-9a-f]{5,} ($balanced_parens)/i);
> +
> +                               $id_length = 0 if ($orig_commit =~ /^[0-9a-f]{12}$/i);
> +                               $id_case = 0 if ($orig_commit !~ /[A-F]/);
> +
> +                               # Always strip leading/trailing parens then double quotes if existing
> +                               $title = substr($title, 1, -1);
> +                               if ($title =~ /^".*"$/) {
> +                                       $title = substr($title, 1, -1);
> +                                       $title_has_quotes = 1;
> +                               }
> +                       }
> +
> +                       my ($cid, $ctitle) = git_commit_info($orig_commit, $id,
> +                                                            $title);
> +
> +                       if ($ctitle ne $title || $tag_case || $tag_space ||
> +                           $id_length || $id_case || !$title_has_quotes) {
> +                               if (WARN("BAD_FIXES_TAG",
> +                                    "Please use correct Fixes: style 'Fixes: <12 chars of sha1> (\"<title line>\")' - ie: 'Fixes: $cid (\"$ctitle\")'\n" . $herecurr) &&
> +                                   $fix) {
> +                                       $fixed[$fixlinenr] = "Fixes: $cid (\"$ctitle\")";
> +                               }
> +                       }
> +               }
> +
>  # Check email subject for common tools that don't need to be mentioned
>                 if ($in_header_lines &&
>                     $line =~ /^Subject:.*\b(?:checkpatch|sparse|smatch)\b[^:]/i) {
> --
> 2.37.3
>