[LLVMdev] [RFC] Raise minimum required CMake version to 3.0

[Renato Golin]

On 11 March 2015 at 14:55, Hal Finkel <hfinkel at anl.gov> wrote:
> I think we should stop fighting about this and ship a version of CMake with LLVM.

We already manage other unstable dependencies like gcc, glibc,
binutils, ninja and python (2.7 vs. 3.0). This is even more true on
non x86 platforms.

We also have increased the development cost (when not using better
C++11 alternatives) because some compilers on some platforms were not
up to the task.

We have made incremental changes to CMake already (2.8 for now), and
bumping it again right now would be unwise, IMO.

Just like we waited MSVC to be mature enough to bump the minimum
requirement to version 13, I think we should wait for more Linux
distributions to pick up CMake 3.0 to bump the version up. We have
used a good pattern for that kind of issue before (with C++11) and it
worked well in the long run. We should continue the pattern.

Bundling CMake with LLVM would make builds more complex. It would
require a bootstrap script (for each platform), so that we can build
CMake, and we'd need it to be done for all projects. The complexity
added is not trivial.

cheers,
--renato