Building clang/cling 3.5 for ROOT on Lion

[Mojca Miklavec]

Hi,

I would like to ask for advice about how to properly support building
ROOT 6 (which builds clang/cling 3.5 as part of the installation) on
Lion.

I'm aware of http://trac.macports.org/wiki/FAQ#libcpp. But it's not
clear to me if dependency on clang 3.5 means that one will be unable
to to run ROOT 6 on 10.7 and earlier. Or if we just need to blacklist
certain compilers.

The first response from upstream was:

> ROOT6 requires C++11, which is supported (using libc++) on 10.8
> and 10.9 e.g. with XCode 5.1.
>
> For 10.7 you can get GCC 4.7 or 4.8 from the usual Mac packagers,
> or build clang with libc++ yourself; either one should work but the
> former might be simpler.

Mojca