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

[dag at cray.com]

David Tweed <david.tweed at gmail.com> writes:

> A personal question: is there any way we could modify some part of the
> build to do some of the "non-fatal but difficult to ignore"
> announcement if the building compiler can't handle the upcoming
> constructs? Eg, just thinking off the top of my head here, could we
> abuse the make check/lit mechanism to get a file with C++11 features
> that are going to be used in X months compiled with the building
> compiler, so that people running projects following ToT and who run
> "make check" regularly will get a new failure if they'll be facing
> problems ahead?

This wouldn't address the main issue as I see it.  I am not worried at
all about LLVM and whether I'll be able to build it with a new toolchain
on our machines.  I'm worried about everything *else* we have integrated
with LLVM that will also need to be built with the new toolchain.  It's
all that other stuff that we need to be able to test before LLVM forces
us to use a new toolchain.

When the LLVM 3.4 release is cut, I'm simply asking that we don't start
using stuff that requires a new toolchain right away.  If we could wait
3-4 months that would allow time for testing.  We can still require a
new toolchain for the 3.5 release, allow C++-11, etc..  We just
shouldn't require it on ToT right away.

                            -David