[PATCH] D27387: [libc++] Add a key function for bad_function_call

[Duncan P. N. Exon Smith via cfe-commits]

Yes, they are:
--
$ clang -dM -x c /dev/null -E -mmacosx-version-min=10.10.0 | grep VERSION_MIN
#define __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ 101000
--

However, they're somewhat awkward, extremely vendor-specific, and unrelated to libc++ version numbers.  I think a separate ABI flag would be easiest to manage.

> On 2016-Dec-05, at 06:44, Eric Fiselier <eric at efcs.ca> wrote:
> 
> s/processor/preprocessor
> 
> On Mon, Dec 5, 2016 at 7:43 AM, Eric Fiselier <eric at efcs.ca> wrote:
> Are the minimum versions detectable in the processor? If so it seems like we could safely configure this change that way.
> 
> /Eric
> 
> On Mon, Dec 5, 2016 at 7:37 AM, Duncan Exon Smith <dexonsmith at apple.com> wrote:
> I haven't looked at the patch, but yes, many developers on our platform back-deploy to older OS versions (and we support that via Clang flags, e.g., -miphoneos-version-min=8.0).  They always build against the newest SDK/headers.
> 
> -- dpnes
> 
> > On Dec 5, 2016, at 00:35, Eric Fiselier via Phabricator <reviews at reviews.llvm.org> wrote:
> >
> > EricWF added a reviewer: dexonsmith.
> > EricWF added a subscriber: dexonsmith.
> > EricWF added a comment.
> >
> > In https://reviews.llvm.org/D27387#613071, @smeenai wrote:
> >
> >> In https://reviews.llvm.org/D27387#612975, @EricWF wrote:
> >>
> >>> I wonder if we should consider this a breaking ABI change and control it using a `_LIBCPP_ABI` macro. @mclow.lists thoughts?
> >>
> >>
> >> This is forward-compatible (as in clients built against an older libc++ would be happy with this version) but not backwards-compatible (as in clients built against this version would not be able to run against an older libc++). Has libc++ been aiming to maintain compatibility in both directions?
> >
> >
> > Hmm, I'm not exactly sure. We don't make backward incompatible changes to existing code often. I wonder if vendors like Apple require such backwards compatibility. Maybe @dexonsmith  can weigh in?
> >
> >
> > https://reviews.llvm.org/D27387
> >
> >
> >
> 
>