Re: Xen Coding style

[Tamas K Lengyel <tamas.k.lengyel@gmail.com>]

On Fri, May 8, 2020 at 8:18 AM Jürgen Groß <jgross@suse.com> wrote:
>
> On 08.05.20 14:55, Tamas K Lengyel wrote:
> > On Fri, May 8, 2020 at 6:21 AM Julien Grall <julien@xen.org> wrote:
> >>
> >> Hi Jan,
> >>
> >> On 08/05/2020 12:20, Jan Beulich wrote:
> >>> On 08.05.2020 12:00, Julien Grall wrote:
> >>>> You seem to be the maintainer with the most unwritten rules. Would
> >>>> you mind to have a try at writing a coding style based on it?
> >>>
> >>> On the basis that even small, single aspect patches to CODING_STYLE
> >>> have been ignored [1],
> >>
> >> Your thread is one of the example why I started this thread. Agreeing on
> >> specific rule doesn't work because it either result to bikesheding or
> >> there is not enough interest to review rule by rule.
> >>
> >>> I don't think this would be a good use of my
> >>> time.
> >>
> >> I would have assumed that the current situation (i.e
> >> nitpicking/bikeshedding on the ML) is not a good use of your time :).
> >>
> >> I would be happy to put some effort to help getting the coding style
> >> right, however I believe focusing on an overall coding style would value
> >> everyone's time better than a rule by rule discussion.
> >>
> >>> If I was promised (reasonable) feedback, I could take what I
> >>> have and try to add at least a few more things based on what I find
> >>> myself commenting on more frequently. But really I'd prefer it to
> >>> be done the other way around - for people to look at the patches
> >>> already sent, and for me to only subsequently send more. After all,
> >>> if already those adjustments are controversial, I don't think we
> >>> could settle on others.
> >> While I understand this requires another investment from your part, I am
> >> afraid it is going to be painful for someone else to go through all the
> >> existing coding style bikeshedding and infer your unwritten rules.
> >>
> >> It might be more beneficial for that person to pursue the work done by
> >> Tamas and Viktor in the past (see my previous e-mail). This may mean to
> >> adopt an existing coding style (BSD) and then tweak it.
> >
> > Thanks Julien for restarting this discussion. IMHO agreeing on a set
> > of style rules ahead and then applying universally all at once is not
> > going to be productive since we are so all over the place. Instead, I
> > would recommend we start piece-by-piece. We introduce a baseline style
> > checker, then maintainers can decide when and if they want to move
> > their code-base to be under the automated style checker. That way we
> > have a baseline and each maintainer can decide on their own term when
> > they want to have their files be also style checked and in what form.
> > The upside of this route I think is pretty clear: we can have at least
> > partial automation even while we figure out what to do with some of
> > the more problematic files and quirks that are in our code-base. I
> > would highly prefer this route since I would immediately bring all
> > files I maintain over to the automated checker just so I never ever
> > have to deal with this again manually. What style is in use to me
> > really doesn't matter, BSD was very close with some minor tweaks, or
> > even what we use to check the style just as long as we have
> > _something_.
>
> Wouldn't it make more sense to have a patch checker instead and accept
> only patches which change code according to the style guide? This
> wouldn't require to change complete files at a time.

In theory, yes. But in practice this would require that we can agree
on a style that applies to all patches that touch any file within Xen.
We can't seem to do that because there are too many exceptions and
corner-cases and personal-preferences of maintainers that apply only
to a subset of the codebase. So AFAICT what you propose doesn't seem
to be a viable way to start.

Tamas