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

[Hal Finkel]

[this is not in reply to anyone in particular]

I don't understand why we don't ship CMake with LLVM. We seem to think of CMake as a stable system dependency (in the same way that we think of make and the shell), and it's not. It is an actively developed project, like LLVM itself, and, frankly, it is not mature enough to be considered part of the base system. Furthermore, it is not clear that it ever will be: CMake's goal of building an abstraction layer over many different build systems, on many different operating systems, combined with our tendency of being on the leading edge of these features, is not likely to lead to a situation where we can rely for long periods of time on the 'stable subset' of the functionality provided. I think we should stop fighting about this and ship a version of CMake with LLVM. We already have imported dependencies on gtest, etc., and while I understand this is different, I think it will likely be worthwhile in the long run. We can always use a suitable system version, if we find one, instead of rebuilding a version we ship.

 -Hal

----- Original Message -----
> From: "David Chisnall" <David.Chisnall at cl.cam.ac.uk>
> To: "Renato Golin" <renato.golin at linaro.org>
> Cc: "jroelofs" <jonathan at codesourcery.com>, "Tobias Grosser" <tobias at grosser.es>, "LLVM Dev" <llvmdev at cs.uiuc.edu>
> Sent: Wednesday, March 11, 2015 8:22:09 AM
> Subject: Re: [LLVMdev] [RFC] Raise minimum required CMake version to 3.0
> 
> On 11 Mar 2015, at 12:45, Renato Golin <renato.golin at linaro.org>
> wrote:
> > 
> > A. LTS Linux users (by far, the biggest constituency among Linux
> > users) are stuck old versions of CMake in their packages.
> 
> To put this in perspective, until the latest Ubuntu LTS release it
> had been impossible to build LLVM without building some dependencies
> manually on Ubuntu LTS.  This didn't seem to be a problem for the
> project then and I don't really see why it would become one now.  It
> was slightly annoying (our Jenkins server had to build a load of
> stuff from source), but RHEL and Ubuntu LTS generally seem to be
> aimed at people who think old software with known security holes is
> better than new software with undiscovered bugs, so there's less
> reason to expect that they'd want to run the very latest LLVM.
> 
> David
> 
> 
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> 

-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory