svn commit: r247710 - projects/calloutng/sys/kern

[John Baldwin]

On Monday, March 04, 2013 3:41:05 pm Attilio Rao wrote:
> On Mon, Mar 4, 2013 at 9:21 PM, John Baldwin <jhb at freebsd.org> wrote:
> > On Monday, March 04, 2013 3:17:30 pm Davide Italiano wrote:
> >> On Mon, Mar 4, 2013 at 4:40 PM, John Baldwin <jhb at freebsd.org> wrote:
> >> > On Sunday, March 03, 2013 8:39:54 am Davide Italiano wrote:
> >> >> Author: davide
> >> >> Date: Sun Mar  3 13:39:54 2013
> >> >> New Revision: 247710
> >> >> URL: http://svnweb.freebsd.org/changeset/base/247710
> >> >>
> >> >> Log:
> >> >>   - Use TRUE/FALSE in lieu of 0/1 for boolean_t variables.
> >> >
> >> > We have stdbool in the kernel.  Why not use that instead of the Machish
> >> > boolean_t?
> >> >
> >> > --
> >> > John Baldwin
> >>
> >> It was originally int, and a couple of days ago Attilio suggested to
> >> move to 'boolean_t'.
> >> Honestly, I didn't argue due to the relative little relevance of the
> >> change, but actually I find the type change more explicative.
> >> I have no strong objections to change it again (in particular because
> >> I think you're suggesting to use bool to be C99 compliant, feel free
> >> to correct me if I'm wrong).
> >>
> >> While here. After closer looking I realized boolean_t is widely used
> >> in the kernel (e.g. sys/kern/). Is this just a common error or is
> >> there something I'm missing?
> >
> > No, it's just older and bool is C99 as you noticed.  I had thought that
> > boolean_t was largely regulated to code from Mach (i.e. sys/vm) and that
> > we should use bool for new code.
> 
> Actually boolean_t is much more widespread in our kernel than the C99
> variant. Moreover style(9) doesn't advertise it either, neither the
> necessity to conform to library defined C99 features (even if present
> in the C99 standard, _Bool is still defined in stdbool.h which is an
> header not present in our kernel).

Err, I thought that mdf@ had proposed importing stdbool.h into our kernel
already?  Ah, yes, the requisite bits are in <sys/types.h>, so 'bool' works
fine.

I think for new code we should prefer C99's bool to boolean_t.

-- 
John Baldwin