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

[Duncan Exon Smith via cfe-commits]

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?
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> 
> 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
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>