Re: [PATCH can-utils v2 1/3] headers: use include/linux only for Linux kernel headers

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

Hello Oliver,

On Mon, Jan 13, 2014 at 10:18:04PM +0100, Oliver Hartkopp wrote:
> On 13.01.2014 21:45, Uwe Kleine-König wrote:
> > On Mon, Jan 13, 2014 at 07:25:20PM +0100, Oliver Hartkopp wrote:
> >> On 13.01.2014 08:20, Uwe Kleine-König wrote:
> >>> On Mon, Jan 13, 2014 at 07:23:55AM +0100, Oliver Hartkopp wrote:
> >>>> And e.g. this
> >>>>
> >>>>>  #include <linux/can.h>
> >>>>> -#include <linux/can/isotp.h>
> >>>>> +#include "isotp.h"
> >>>>>  #include <linux/if_tun.h>
> >>>>
> >>>> should be avoided too.
> >>> Why?
> >>
> >> When isotp hits the kernel, there's no need to adapt all userland programs.
To be honest, it's not that hard to update all userland programs. I did
it with:

	perl -p -i -e 's,^#include <whatever/can/isotp.h>$,#include "isotp.h",' isotp*

(well, plus some reformatting, but meh).

> > ah, didn't know that isotp targets the kernel. There is nothing in next
> > yet. I wonder if it's sensible to put it into can-utils' copy of the
> > kernel headers then. If you ask me keep isotp.h in / until it hits the
> > kernel, then sync the headers and switch the programs explicitly. Only
> > my 0.02 €.
> 
> What's the benefit of moving it to root and then moving it back to the includes?
The benefit is that there is less chance for surprises. Updating the
kernel header copy still has a manual component when there are files in
can-utils that are not existing in the kernel. Also I like changes to be
explicit. When isotp.h is now kept in can-utils/include/linux and later
hits the kernel there is no explicit commit that marks the start of
using the kernel header and changing the procedure how to sync kernel
headers. YMMV

> Please let it stay in the current place.
To late for v3, only read your mail when I sent it out.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |