[llvm-dev] wasteful cmake defaults

[David Chisnall via llvm-dev]

On 18/11/2020 18:40, Michael Kruse wrote:
> First, it is not rare that you are working on an LTS release, but need
> a newer compiler. I myself am still working on a remote machine using
> Red Hat EL7 with gcc 4.8 and no clang pre-installed. 

We build nightly packages for Ubuntu LTS releases, what do we need to do 
to add the same support for Red Hat?

> Since I am not
> the admin of that machine, I have to compile clang (and gcc) with a
> prefix in my home directory.

As I recall, nothing in the LLVM install hard codes the install 
location.  Deb packages are just ar archives, RPMs are just cpio 
archives, so users without admin access could just grab the latest 
nightly package for their distro and extract it into their home 
directory.  We could provide a script for that (or, to be more friendly, 
build a .txz from the same directory tree).

> Second, for OpenMP target offloading, we recommend users to compile
> the latest trunk because it is under heavy development. In practice,
> if you are using target offloading, you have to compile it yourself
> because it needs to match the installed version of CUDA (or ROCm) and
> I have yet to see a distribution where OpenMP target offloading works
> out of the box.

That sounds unfortunate.  I presume that there is a long-term plan for 
fixing this?

David