[llvm-dev] Using C++14 code in LLVM

[David Chisnall via llvm-dev]

On 3 Oct 2016, at 20:06, Reid Kleckner via llvm-dev <llvm-dev at lists.llvm.org> wrote:
> 
> I'm not in favor of dropping GCC 4.8 support yet. It's the default compiler for Ubuntu Trusty, which is from 2014, which isn't that old. I think it's important that LLVM build out of the box with the commonly installed system compiler.

We are currently using Trusty (14.04) on our teaching machines - it’s an LTS release that’s still supported.  We upgraded two years ago because we couldn’t build LLVM with the previous LTO release without my needing to build gcc, libstdc++, and CMake from source and install them with futzed rpaths.  This was a very fragile environment for teaching.

We’re likely to keep 14.04 for another year, because 16.04 breaks various things used in other courses.  Building the latest LLVM release wasn’t too bad this time, but it did require that I built a new CMake, because apparently some time between 3.7 and 3.9 we bumped the minimum CMake requirement to one that doesn’t ship with 14.04.

If anyone is looking to hire students with LLVM experience, please remember that most university lab systems are using some form of long-term support release of their institution's favourite OS and it’s hard to persuade people to teach using LLVM if they can’t even build it on their lab machines.

David