[libcamera-devel] [PATCH v1 4/4] utils: checkstyle: Add trailers checker

[Kieran Bingham]

Quoting Naushir Patuck via libcamera-devel (2023-07-10 11:33:54)
> Hi Laurent,
> 
> I've updated my tree and this change now seems to break my pre-commit hook:

Yikes - You've gone pre-commit ;-)

I usually use post-commit - as pre-commit makes it harder to actually
work in my experience as it prevents the commits in the first place.

I think post-commit is a much better use of the hooks, as it tells you
of issues while not getting in the way.

Still - pre-commit is supposed to be supported - so I'll swap over and
see if I can debug this.

--
Kieran

> 
> naushir at work:~/libcamera/ $ git commit -a -s
> ---------------
>  Staged changes
> ---------------
> Traceback (most recent call last):
>   File "/home/naushir/projects/libcamera/./utils/checkstyle.py", line
> 1052, in <module>
>     sys.exit(main(sys.argv))
>   File "/home/naushir/projects/libcamera/./utils/checkstyle.py", line
> 1042, in main
>     issues += check_style(top_level, commit, args.checkers)
>   File "/home/naushir/projects/libcamera/./utils/checkstyle.py", line
> 935, in check_style
>     for issue in checker.check(commit, top_level):
>   File "/home/naushir/projects/libcamera/./utils/checkstyle.py", line
> 479, in check
>     for trailer in commit.trailers:
>   File "/home/naushir/projects/libcamera/./utils/checkstyle.py", line
> 239, in trailers
>     return self._trailers
> AttributeError: 'StagedChanges' object has no attribute '_trailers'.
> Did you mean: 'trailers'?
> 
> I'm using the same old hook found in ./utils/hooks/pre-commit. I've briefly
> tried debugging, but quickly found that I'm in way over my depth with the
> checkstyle.py script :-)
> 
> Regards,
> Naush
> 
> On Mon, 12 Jun 2023 at 23:48, Laurent Pinchart via libcamera-devel
> <libcamera-devel at lists.libcamera.org> wrote:
> >
> > The libcamera git history contains numerous examples of incorrect commit
> > message trailers due to invalid trailer types (e.g. Change-Id), typos
> > and other small issues. Those went unnoticed through reviews, which
> > shows that an automated checker is required.
> >
> > Add a trailers checker to checkstyle.py to catch invalid or malformed
> > trailers, with a set of supported trailers that match libcamera's commit
> > message practices. New trailer keys can easily be added later as new
> > needs arise.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > ---
> > This reports a total of 42 issues through the project's history. 37 of
> > them should not be controversial:
> >
> > - Trailer keys not valid for libcamera ('Cc', 'Change-Id', 'Inspired-by'
> >   and 'Reported-on')
> >
> > - Typos in trailer keys ('Fixed' instead of 'Fixes', 'Reviewed' instead
> >   of 'Reviewed-by' and 'Signed-off-By' instead of 'Signed-off-by')
> >
> > - Typos in e-mail address (missing display name, missing space before
> >   '<' and missing trailing '>')
> >
> > - Link in 'Fixes' trailer (should be a commit)
> >
> > - Too short commit ID in 'Fixes' trailer
> >
> > - Typos in 'Fixes' trailer (extra 'commit' before commit ID, missing
> >   space or extra ':' after commit ID, missing '"' around commit subject)
> >
> > The five remaining issues may benefit from discussions:
> >
> > - Invalid trailer key 'Co-developed-by' (one instance). This is a
> >   trailer key commonly used in the kernel, but git..b both recommend
> >   Co-authored-by. I'm sure which option would be best, so I haven't
> >   included either for now.
> >
> > - Typo in 'Reported-by' trailer for issues reported by Coverity (one
> >   instance). 'Reported-by' usually has an e-mail address value, but we
> >   have commonly used 'Coverity CID=<CID>' for issues reported by
> >   Coverity. I've tentatively added support for this (feedback is
> >   welcome), and one commit still got flagged as its 'Reported-by'
> >   trailer has a space instead of an '=' after 'CID'.
> >
> > - Usage of a github user URL in 'Reported-by' (one instance). Our policy
> >   is to be able to identify users by name and e-mail address for
> >   'Signed-off-by' trailers, and I would prefer covering 'Reported-by'
> >   trailers too. If someone *really* doesn't want their name included in
> >   the git log when reporting an issue, we can simply omit the
> >   'Reported-by' trailer.
> >
> > - Usage of URLs in 'Reported-by' to point to buildbot.libcamera.org (two
> >   instances). This should use a 'Link' trailer instead.
> > ---
> >  utils/checkstyle.py | 80 +++++++++++++++++++++++++++++++++++++++++++--
> >  1 file changed, 78 insertions(+), 2 deletions(-)
> >
> > diff --git a/utils/checkstyle.py b/utils/checkstyle.py
> > index e68c874609bc..3558740d389d 100755
> > --- a/utils/checkstyle.py
> > +++ b/utils/checkstyle.py
> > @@ -210,13 +210,23 @@ class Commit:
> >
> >      def _parse(self):
> >          # Get the commit title and list of files.
> > -        ret = subprocess.run(['git', 'show', '--format=%s', '--name-status',
> > +        ret = subprocess.run(['git', 'show', '--format=%s%n%(trailers:only,unfold)', '--name-status',
> >                                self.commit],
> >                               stdout=subprocess.PIPE).stdout.decode('utf-8')
> >          lines = ret.splitlines()
> > -        self._files = [CommitFile(f) for f in lines[1:] if f]
> > +
> >          self._title = lines[0]
> >
> > +        self._trailers = []
> > +        for index in range(1, len(lines)):
> > +            line = lines[index]
> > +            if not line:
> > +                break
> > +
> > +            self._trailers.append(line)
> > +
> > +        self._files = [CommitFile(f) for f in lines[index:] if f]
> > +
> >      def files(self, filter='AMR'):
> >          return [f.filename for f in self._files if f.status in filter]
> >
> > @@ -224,6 +234,10 @@ class Commit:
> >      def title(self):
> >          return self._title
> >
> > +    @property
> > +    def trailers(self):
> > +        return self._trailers
> > +
> >      def get_diff(self, top_level, filename):
> >          diff = subprocess.run(['git', 'diff', '%s~..%s' % (self.commit, self.commit),
> >                                 '--', '%s/%s' % (top_level, filename)],
> > @@ -424,6 +438,68 @@ class TitleChecker(CommitChecker):
> >                              'possible candidates are ' + candidates)]
> >
> >
> > +class TrailersChecker(CommitChecker):
> > +    commit_regex = re.compile(r'[0-9a-f]{12}[0-9a-f]* \(".*"\)')
> > +
> > +    coverity_regex = re.compile(r'Coverity CID=.*')
> > +
> > +    # Simple e-mail address validator regex, with an additional trailing
> > +    # comment. The complexity of a full RFC6531 validator isn't worth the
> > +    # additional invalid addresses it would reject.
> > +    email_regex = re.compile(r'[^<]+ <[^@>]+@[^>]+>( # .*)?')
> > +
> > +    link_regex = re.compile(r'https?://.*')
> > +
> > +    @staticmethod
> > +    def validate_reported_by(value):
> > +        if TrailersChecker.email_regex.fullmatch(value):
> > +            return True
> > +        if TrailersChecker.coverity_regex.fullmatch(value):
> > +            return True
> > +        return False
> > +
> > +    known_trailers = {
> > +        'Acked-by': email_regex,
> > +        'Bug': link_regex,
> > +        'Fixes': commit_regex,
> > +        'Link': link_regex,
> > +        'Reported-by': validate_reported_by,
> > +        'Reviewed-by': email_regex,
> > +        'Signed-off-by': email_regex,
> > +        'Suggested-by': email_regex,
> > +        'Tested-by': email_regex,
> > +    }
> > +
> > +    trailer_regex = re.compile(r'([A-Z][a-zA-Z-]*)\s*:\s*(.*)')
> > +
> > +    @classmethod
> > +    def check(cls, commit, top_level):
> > +        issues = []
> > +
> > +        for trailer in commit.trailers:
> > +            match = TrailersChecker.trailer_regex.fullmatch(trailer)
> > +            if not match:
> > +                raise RuntimeError(f"Malformed commit trailer '{trailer}'")
> > +
> > +            key, value = match.groups()
> > +
> > +            validator = TrailersChecker.known_trailers.get(key)
> > +            if not validator:
> > +                issues.append(CommitIssue(f"Invalid commit trailer key '{key}'"))
> > +                continue
> > +
> > +            if isinstance(validator, re.Pattern):
> > +                valid = bool(validator.fullmatch(value))
> > +            else:
> > +                valid = validator(value)
> > +
> > +            if not valid:
> > +                issues.append(CommitIssue(f"Malformed value '{value}' for commit trailer '{key}'"))
> > +                continue
> > +
> > +        return issues
> > +
> > +
> >  # ------------------------------------------------------------------------------
> >  # Style Checkers
> >  #
> > --
> > Regards,
> >
> > Laurent Pinchart
> >