[LLVMdev] [cfe-dev] RFC: A proposal to move toward using C++11 features in LLVM & Clang / bounding support for old host compilers

[Eric Christopher]

On Tue, Nov 12, 2013 at 10:20 AM,  <dag at cray.com> wrote:
> Chris Lattner <clattner at apple.com> writes:
>
>>> If we say we support 4.7.x, then I don't think we should use c++11
>>> features that aren't supported and working on all 4.7.x versions.
>>
>> Why not just explicitly say 4.7.1 and later?  Are there any buildbots
>> that build with 4.7.1 yet?  If not, that should be a prerequisite to
>> making the move.
>
> Does that statement include 4.8.x and beyond?
>
> My main concern, as outlined in another message I just sent, is what
> "4.7.1 and later" means in terms of support from upstream.  Do the
> inevitable problems discovered get worked around in the LLVM project
> sources or are problematic compilers simply noted as such in the
> documentation, potentially forcing users to upgrade their toolchain
> again?
>
> I can see tradeoffs with each strategy.  It's important to be clear so
> we have proper expectations.
>
> I'm pushing on this because although most toolchain upgrades are simple,
> when they go bad they go REALLY bad.  It's a risk that has to be
> managed.
>

This is no different than you have to deal with today. Please stop
conflating these issues.

-eric