[PATCH] Documentation: checkpatch: Tweak BIT() macro include

[Dwaipayan Ray]

On Thu, May 20, 2021 at 3:15 PM Andrew Jeffery <andrew at aj.id.au> wrote:
>
>
>
> On Thu, 20 May 2021, at 18:47, Dwaipayan Ray wrote:
> > On Thu, May 20, 2021 at 12:55 PM Andrew Jeffery <andrew at aj.id.au> wrote:
> > >
> > >
> > >
> > > On Thu, 20 May 2021, at 16:28, Lukas Bulwahn wrote:
> > > > On Thu, May 20, 2021 at 3:57 AM Andrew Jeffery <andrew at aj.id.au> wrote:
> > > > >
> > > > > While include/linux/bitops.h brings in the BIT() macro, it was moved to
> > > > > include/linux/bits.h in [1]. Since [1] BIT() has moved again into
> > > > > include/vdso/bits.h via [2].
> > > > >
> > > > > I think the move to the vDSO header can be considered a implementation
> > > > > detail, so for now update the checkpatch documentation to recommend use
> > > > > of include/linux/bits.h.
> > > > >
> > > > > [1] commit 8bd9cb51daac ("locking/atomics, asm-generic: Move some macros from <linux/bitops.h> to a new <linux/bits.h> file")
> > > > > [2] commit 3945ff37d2f4 ("linux/bits.h: Extract common header for vDSO")
> > > > >
> > > > > Cc: Jiri Slaby <jirislaby at kernel.org>
> > > > > Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
> > > >
> > > > Looks sound to me.
> > > >
> > > > I would prefer a bit of word-smithing the commit message by just
> > > > removing the references:
> > > >
> > > > So:
> > > >
> > > > > While include/linux/bitops.h brings in the BIT() macro, it was moved to
> > > > > include/linux/bits.h in commit 8bd9cb51daac ("locking/atomics, asm-generic: Move some macros from <linux/bitops.h> to a new <linux/bits.h> file"). Since that commit, BIT() has moved again into
> > > > > include/vdso/bits.h via commit 3945ff37d2f4 ("linux/bits.h: Extract common header for vDSO").
> > > > >
> > > > > I think the move to the vDSO header can be considered a implementation
> > > > > detail, so for now update the checkpatch documentation to recommend use
> > > > > of include/linux/bits.h.
> > > > >
> > > >
> > > > And then drop references [1] and [2].
> > > >
> > > > Andrew, what do you think?
> > >
> > > I mostly did this because initially I wrapped the commit message and
> > > checkpatch spat out errors when it failed to properly identify the
> > > commit description for [1]. But, leaving the description unwrapped
> > > inline in the text feels untidy as it's just a work-around to dodge a
> > > shortcoming of checkpatch.
> > >
> > > With the reference style the long line moves out of the way and
> > > checkpatch can identify the commit descriptions, at the expense of
> > > complaints about line length instead. But the line length issue was
> > > only a warning and so didn't seem quite so critical.
> > >
> > > While the referencing style is terse I felt it was a reasonable
> > > compromise that didn't involve fixing checkpatch to fix the checkpatch
> > > documentation :/
> > >
> >
> > Hey,
> > Can you share which wrap around caused the checkpatch errors
> > to be emitted? We can try to fix that.
> >
> > I was able to wrap it without checkpatch complaining. You might consider
> > replacing it with this if you wish?
> >
> > While include/linux/bitops.h brings in the BIT() macro, it was moved to
> > include/linux/bits.h in commit 8bd9cb51daac ("locking/atomics, asm-generic:
> > Move some macros from <linux/bitops.h> to a new <linux/bits.h> file").
>
> This wording works because the commit description is only split across
> two lines. With the wording I had it was split across three, and this
> caused checkpatch to barf. If we do this:
>

Yes it won't work for 3 lines. We are checking only for an additional line
for split commit descriptions. Might be a thing to improve in the future.

> While include/linux/bitops.h brings in the BIT() macro, it was moved to
> include/linux/bits.h in commit 8bd9cb51daac ("locking/atomics, asm-generic:
> Move some macros from <linux/bitops.h> to a new <linux/bits.h>
> file").
>
> we get:
>
> ERROR: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit 8bd9cb51daac ("locking/atomics, asm-generic: Move some macros from <linux/bitops.h> to a new <linux/bits.h> file")'
> #7:
> include/linux/bits.h in commit 8bd9cb51daac ("locking/atomics, asm-generic:
>
> total: 1 errors, 0 warnings, 8 lines checked
>
> Anyway, I've replaced the commit message with your suggestion:
>
> https://lore.kernel.org/linux-doc/20210520093949.511471-1-andrew@aj.id.au/
>
> Thanks for work-shopping it :)
>

Thanks for the patch :)

Dwaipayan.