Re: [RFC PATCH] checkpatch: Make the 80-character limit a --strict check only

[Josh Triplett <josh@joshtriplett.org>]

On Mon, Oct 07, 2013 at 12:28:26PM -0700, Joe Perches wrote:
> On Mon, 2013-10-07 at 12:18 -0700, Josh Triplett wrote:
> > The 80-character limit is not a hard-and-fast rule, nor should it be
> > applied blindly by people running checkpatch and fixing its warnings.
> > Sometimes it's better to violate the 80-character "limit" in the name of
> > readability, and when it isn't, it's often better to refactor into a
> > function or otherwise restructure the code rather than just finding
> > increasingly awkward places to break lines.
> > 
> > Thus, change checkpatch's LONG_LINE warning to a --strict CHK instead.
> > Anyone wanting to use checkpatch to check for this can easily enough
> > enable --strict or turn on LONG_LINE explicitly, but it shouldn't be
> > part of the default warnings.
> 
> I don't agree with this.
> 
> CodingStyle says:
> ----------------------
> The limit on the length of lines is 80 columns and this is a strongly
> preferred limit.
> ----------------------

Which is the subject of much controversy and extensive discussion, and
the consensus on the list (including by many maintainers) frequently
differs from that.

> People should be encouraged to use 80 column lines and as well
> should learn to ignore messages they don't agree with.

I've seen far more examples of the 80-column limit making code less
readable rather than more.  It's only really helpful when it forces code
restructuring, *not* when it just forces an arbitrary line break.

> If people are using checkpatch prior to any scripted git am,
> then just as easily they could add --ignore=LONG_LINE.

Which random folks running checkpatch on staging drivers and trying to
help don't necessarily know to do.  The defaults should cater to the
primary use case, and the 80-column limit is not something to apply
blindly.  It falls in the same category as some of the warnings the
kernel emits with W=2 or so: sometimes helpful, often noise.

- Josh Triplett