Re: [gpsd-dev] featuretest macros

[Gary E. Miller]

Yo Greg!

On Fri, 21 Jun 2019 18:37:45 -0400
Greg Troxel <address@hidden> wrote:

> > Which function?  I would like to document that in the SConstruct
> > file.  
> 
> I don't remember the name, and it came up in some other program,
> nothing to do with gpsd.

Hard facts are useful.

>  gpsd compiles on netbsd-8 without defines,
> so therefore I am 99.99% sure gpsd does not use it.

And Fre just proved that earlier NetBSD requires some defines.

> > Before glibc 2.10 and 2.19 things were ugly.  So testing older
> > stuff, like the newest RHEL, is important.  
> 
> You say older/newest, and I am guessing that translates to "current
> stable releases of any LTS distribution still under support".

I specifically mentioned RHEL.  With RHEL, the latest release contains
very old libraries.  At a minimum :old glibc that requires defines.

> > I'd love to test, after 3.19.  But recent experience does not make
> > me feel confident that the defines can all go.  They can likely
> > be made better.  
> 
> Definitely; I don't really think we can get rid of them.  But as an
> example, defining _XOPEN_SOURCE to something and then defining
> _NETBSD_SOURCE is basically a noop, at least on NetBSD.   So if we can
> prune, that would be good.

Something for Fred to test, when he gets back.  After 3.19.  That is
exaxctly why I split the defines in SConstruct up by distro.

> 
> > Tested on Gentoo stable.  It fails.  
> 
> Interesting.  I guess the question is (for post 3.19) which function,
> what standard defines that function, and if that result is
> expected.

Check out SConstruct.  I have already done so.

>  I am really unclear on strlcpy; it's normal now in
> BSD-land, and I expect most places, but Gentoo might need some
> _BSD_SOURCE define to see it.

Nothing to do with Gentoo.  Gentoo can use many different C libs.  This
is specific to glibc, and is documented in the glibc man pages.  As
noted in SConstruct.

RGDS
GARY
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Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
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