Re: [PATCH] xen: Update minimum toolchain requirements

[Jan Beulich <jbeulich@xxxxxxxx>]

On 07.03.2025 18:54, Andrew Cooper wrote:
> GCC 4.1.2 is from 2007, and Binutils 2.16 is a similar vintage.  Clang 3.5 is
> from 2014.  Supporting toolchains this old is a massive development and
> testing burden.
> 
> Set a minimum baseline of GCC 5.1 across the board, along with Binutils 2.25
> which is the same age.  These were chosen *3 years ago* as Linux's minimum
> requirements because even back then, they were ubiquitous in distros.

I'm certainly fine with this bump, but my main earlier request remains: I'd
like it to be clear up front what the criteria are going to be for future
bumps. Imo what Linux does is at best a data point; we don't need to follow
what they do.

>  Choose
> Clang/LLVM 11 as a baseline for similar reasons; the Linux commit making this
> change two years ago cites a laudry list of code generation bugs.

I'm less happy about this one. It'll mean I now also need to arrange for
building Clang on my own, which so far I was quite happy to be able to avoid.

Tangentially, as also mentioned during earlier discussions, it would also be
nice to have an understanding what other basic platform components (e.g.
coreutils) are required to fulfill certain minimal requirements. While
putting in place a custom toolchain is (to me at least) relatively easy,
doing the same for other base platform software isn't. For some of the very
old systems I try to keep testing Xen on, extra requirements there may mean
that building Xen there isn't going to be possible anymore. Which in turn
may mean running the toolstack (built on a newer distro) there may also not
be possible anymore. Which would, perhaps severely, limit the usefulness of
such testing attempts.

Jan