Re: [PATCH] Use __BSD_VISIBLE for RTEMS <sys/_termios.h>

[Yaakov Selkowitz <yselkowitz@cygwin.com>]

On 2017-05-23 10:16, Craig Howland wrote:
> On 05/23/2017 04:23 AM, Sebastian Huber wrote:
>> The Termios header <sys/_termios.h> used _POSIX_SOURCE directly to
>> determine if a thing should be exposed to the user.  This circumvented
>> the feature mechanisms of <sys/cdefs.h>.
> Would you please explain why !_POSIX_SOURCE being replaced with
> __BSD_VISIBLE rather than, for example, !__POSIX_VISIBLE?  That is, you
> seem to not only be updating to sys/features.h macro names, but also
> shifting exactly how the gate is done.  (I'm not saying it is
> necessarily incorrect, just that the explanation does not mention the
> logic change.  The two are not logical opposites, so an implication is
> that the original gate of POSIX is not really the right one.)

LGTM.  This goes along with last year's feature test macros overhaul. 
Feature test macros are meant to be inclusive, not exclusive (with a few 
exceptions not relevant here), and so the original guards weren't really 
correct to start with.

-- 
Yaakov