Cygwin sysconf.cc

[Corinna Vinschen]

On Mar  2 21:35, Corinna Vinschen wrote:
> On Mar  2 12:45, Brian Inglis wrote:
> > On 2022-03-02 01:25, Corinna Vinschen wrote:
> > > Hi Brian,
> > > 
> > > On Mar  1 13:20, Brian Inglis wrote:
> > > > Interested in a patch for sysconf.cc to return:
> > > > 
> > > >       _SC_TZNAME_MAX => TZNAME_MAX and
> > > > _SC_MONOTONIC_CLOCK => _POSIX_MONOTONIC_CLOCK?
> > > 
> > > not sure I understand the question.  Both are already implemented.
> > > 
> > >    $ getconf -a | egrep '(TZNAME_MAX|MONOTONIC_CLOCK)'
> > >    _POSIX_TZNAME_MAX                   6
> > >    TZNAME_MAX                          undefined
> > >    _POSIX_MONOTONIC_CLOCK              200809
> > 
> > Sorry, must have been looking at very *OLD* version online, as
> > _SC_CLOCK_SELECTION and _SC_MONOTONIC_CLOCK were not defined.
> > 
> > Why did you not define _SC_TZNAME_MAX => _POSIX_TZNAME_MAX when you tweaked
> > it?
> 
> Because it's wrong.  _POSIX_TZNAME_MAX is just a minimum value required
> by POSIX, not the correct value to return for TZNAME_MAX.
> 
> > My rereading of the man and POSIX pages leads me to believe that for all
> > known values of _SC_... the entries now showing {nsup, {c:0}} should be
> > {cons, {c:-1L}} supported but undefined, and only out of range values for
> > the parameter should be treated as {nsup, {c:-1L}}?
> 
> These are really not undefined, but not supported on Cygwin.  That's
> why they return with EINVAL.  I see what you mean, though, let me think
> about it.

Yep, I guess you're right.  I compared this with what Linux returns
for the unsupported tracing options.  See commits cf00bba99a61 and
fcec4830abf0.


Thanks,
Corinna