[llvm-dev] RFC: Import of Integer Set Library into LLVM source tree

[Tobias Grosser via llvm-dev]

On Fri, Jan 19, 2018, at 05:47, Chris Lattner via llvm-dev wrote:
> 
> 
> > On Jan 18, 2018, at 6:02 AM, Michael Kruse <llvmdev at meinersbur.de> wrote:
> > 
> > 2018-01-18 6:40 GMT+01:00 Chris Lattner <clattner at nondot.org>:
> >> Great, I think that that would be a fine approach: you can have the cmake logic detect which version of isl is installed and fail if it is the wrong version.  This would address my concern.
> > 
> >> The motivation explained in the original email seemed to hinge around the fact that Polly’s unit tests depend on accidental details of ISL that change across releases.  If you can fix that, then it seems more plausible to unbundle it.
> >> 
> >> If you can’t fix that, and can’t replace ISL, then the best approach seems to have CMake detect and reject incompatible versions.
> > 
> > This would require buildbot admins to regularly install new versions of isl.
> 
> It seems like you can choose how frequently to update.  Updating every 6 
> to 12 months doesn’t seem overly onerous, and still gives the benefit of 
> updates from the upstream project.

We tend to update isl at certain times more often and prefer to have a fast turnaround in updates. The reason is that if a new LLVM change exposes a bug we  would like to fix the bug in isl immediately and want to get this fix out as fast as possible.  Should we in this case ask all buildbot admins to update? What about the debian/ubuntu builds?

Best,
Tobias