[Linux-kernel-mentees] [PATCH v2] checkpatch: improve email parsing

[Joe Perches]

On Tue, 2020-11-03 at 09:10 +0100, Lukas Bulwahn wrote:
> Maybe you can coordinate among each other who would want to create
> suitable fix rules here?

Yes please.

> Also, start with the class of the most frequent mistakes for
> unexpected content after email addresses.
> 
> I imagine that a maintainer can simply run a tag sanitizing script
> which just cleans up those stupid mistakes before creating their git
> trees or sending git pulls to Linus.

Does anyone really do that?
It generally requires rebasing or post processing each commit after
being committed before another commit occurs.

> Let us try to add these
> sanitizing rules to checkpatch.pl with fix options for now; if that
> sanitizing feature becomes a monster script of its own within
> checkpatch.pl, we can refactor that into an independent script for
> cleaning up.

I rather doubt an independent script is going to be worthwhile
as these rules shouldn't be all that complex.

The only prefixes acceptable for a stable address should be
CC:|Cc:|cc:.  There are 2 uses in the last 100k commits for
Signed-off-by: and Acked-by: with stable addresses, those should have a
message/warning emitted in the future.

The forms used with those cc: stable addresses:

2777	stable without comment
1381	stable # comment
74	stable [ comment ]

So I suggest standardizing on no comment and # comment with any other
style getting a warning.

For non-stable <foo>-by: and cc: addresses and other signatures:

Likely any content after a email address other than a parenthesized
block should have some checkpatch message emitted.

This should be OK:

Signed-off-by: Full Name (comment) <address at domain.tld> (maintainer:...)

But perhaps this should not be OK:

Signed-off-by: Full Name (comment) <address at domain.tld> # comment

There are 316 uses of this # comment style in the last 100k commits
and 103 with (comment) after the address.
Maybe the # use should be ok, maybe not.

And anyone that uses a multiple comments in a name or a even
a single comment in the email address should also get warned.

The below should not be OK even if actually valid address forms:

Signed-off-by: Full (comment1) Name (comment2) <address at domain.tld>
Signed-off-by: Full Name <address@(comment)domain.tld>