bug#27810: NS runtime feature detection

[Alan Third]

On Tue, Sep 12, 2017 at 01:01:56PM -0700, David Caldwell wrote:
> On 8/12/17 8:51 AM, Alan Third wrote:
> > Basically, instead of detecting all macOS features at compile‐time,
> > we’ve stuck in some code to detect them at run‐time. It causes
> > compiler warnings, so by default it still limits features to those
> > available at build‐time, but if you do something like:
> > 
> >     ./configure --with-ns CFLAGS="-DMAC_OS_X_VERSION_MIN_REQUIRED=1060 -O3 
> > -g"
> > 
> > when building on macOS Sierra, you should, in theory, end up with an
> > executable that will work correctly on every version of macOS back to
> > 10.6, inclusive. We haven’t been able to properly test portability yet
> > as it requires including dynamic libraries.
> 
> I would love that. As far as I know, that's the way Apple recommends
> doing feature detection.

Well, the good news is that the patch was committed to master a wee
while ago and the above command should build the dynamic version. It
builds here on 10.12 with just a few deprecation warnings.

We’ve still not been able to confirm whether it works properly, so if
you’d be willing to help us test it that would be great.

-- 
Alan Third