[compiler-rt] r233215 - On OS X, explicitly use libc++

[Hans Wennborg]

On Thu, Apr 16, 2015 at 4:18 PM, Kuba Brecka <kuba.brecka at gmail.com> wrote:
> We do "MACOSX_DEPLOYMENT_TARGET=10.6 cmake" to configure compiler-rt.
> Does ASan ignore that and use current OS instead?
>
> Note that this should only apply to sanitizers - the parts of compiler-rt
> that are used for regular binaries are not dylibs, but .a files, and their
> required OS X version should be much lower.
>
>
> Do the non-sanitizer binaries not care about MACOSX_DEPLOYMENT_TARGET?
> What OS version are they built against? If they are always built
> against 10.6 or less, we could just stop setting the target
> specifically, and our problems would go away, I think.
>
>
> Wait, so is this issue about the non-sanitizer parts of compiler-rt, or
> about ASan not working/building on 10.6?  If it’s about ASan, then I’m not
> sure we want change the behavior, because ASan currently requires 10.7+.
>
> The required OS X version for ASan was bumped from 10.6 to 10.7 in r219302,
> see
> http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20141006/238850.html.
> If you think ASan should keep supporting 10.6, then let’s discuss that
> (Alexander probably knows more), but it seems to me that failing to build
> with "MACOSX_DEPLOYMENT_TARGET=10.6” is correct behavior now.

ASan requiring 10.7 is fine for us.

The problem is that we're only doing a single build of Clang and
compiler-rt, and we use that for both non-asan and asan builds of
Chrome. If I build compiler-rt with MACOSX_DEPLOYMENT_TARGET=10.7, are
you saying that the non-asan parts of compiler-rt will still work on
10.6 machines? Because that's all I need.

Apologies for the confusion here. I don't really know much about
compiler-rt or Mac.