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

[dag at cray.com]

Renato Golin <renato.golin at linaro.org> writes:

> But what Chandler said is more than enough for all changes: 4.7.x is
> the minimal GCC version (with x = 1 being the oldest most stable, but
> if you really need x = 0, who cares?), 2012 for VisualStudio, 3.1 for
> Clang. Any release or trunk version after that, with any patches that
> you might want to include, is really up to you. I would recommend you
> to use the newest version of any compiler you want, as that would
> avoid the same painful process next time, but that's not always
> possible and I appreciate it.
>
> I don't think it's possible to be more precise than that.

I get what you're saying.  What I'm worried about is "4.7.x" not being
fully supported by upstream.  Let's say we pick 4.7.4.  We do all of our
testing against that and ensure everything works.  What happens if later
on we (the LLVM community) discover that 4.7.4 is buggy compiling LLVM?
Will upstream work around the problem in the sources or will we be
forced to change toolsets again?

We're likely going to go with gcc 4.8.1 due to some other internal
requirements and in hopes that it will avoid another forced change when
LLVM allows more C++11 (which can't happen soon enough IMHO :)).

I realize it's impossible to pick one compiler for everyone and I
apologize if I was unclear about that.  But I think it is important to
have a set of "blessed" compilers so people have certainty things won't
change out from under them.  If we pick something outside the blessed
set, that's on us.

                             -David