[llvm-dev] RFC: LLVM Build System Future Direction

Neil Nelson via llvm-dev llvm-dev at lists.llvm.org
Tue Oct 29 20:58:20 PDT 2019

This page will show which cmake versions install with the different 
Ubuntu releases.

xenial 16.04 cmake 3.5.1

bionic 18.04 cmake 3.10.2

cosmic 18.10 cmake 3.12.1

disco 19.04 cmake 3.13.4

eoan 19.10 cmake 3.13.4

19.10 is a new release as of 10/20. And it is common to use the LTS 
releases with the last one being 18.04, cmake 3.10.2.

For around the last decade or so it has been bad form to override the 
standard release packages, a rule I expect is well known to those on the 
LTS releases. Of course those on different OS's will have different 
standards but as with all these software package dependencies there is 
likely some release level that does not overly burden a primary number 
of users, while still burdening the remainder, but where nevertheless a 
reasonable line has to be drawn.

Drawing the line at everyone, which could well be the case here, may be 
more than what is required.

Neil Nelson

On 10/29/19 11:09 AM, Chris Bieneman via llvm-dev wrote:
> ...
> TL;DR: We should move to CMake 3.15 (RFC incoming). We should make 
> `all` really `all`. We should strive to reduce complexity and remove 
> options, specifically options that aren't relevant to the monorepo. We 
> should work to standardize workflows. We need to keep thinking about 
> how to build runtime projects.
> ...
> We had a brief discussion around raising the minimum required CMake 
> version. The general consensus was that since CMake provides binary 
> packages for most common OSs, and building CMake from source has lower 
> system requirements than LLVM and is very simple, nobody saw any 
> barrier to adopting new versions. Initially I suggested moving to 
> CMake 3.11 or 3.12, I believe it was James Knight who said the actual 
> cost of updating the bots is the hard part in raising the version, so 
> maybe we should just take the newest. That reasoning made sense to 
> everyone at the roundtable and there were no objections at the 
> roundtable to moving to CMake 3.15. Look for an RFC from me shortly 
> that will propose that and lay out a timeline.
> ...
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20191029/4b8e3787/attachment.html>

More information about the llvm-dev mailing list