Re: Bountysource campaign for gcc-vax

["Maciej W. Rozycki" <macro%orcam.me.uk@localhost>]

On Sun, 2 May 2021, Johnny Billquist wrote:

> > >   The change has been approved to backport and I have committed it now,
> > > so it will be included with upcoming GCC 11.2.
> > 
> > That's very great to hear. Will be curios whether a full bootstrap will work
> > on NetBSD/VAX in the foreseeable future again.
> 
> Agreed that it's great to hear. I'm also very keen on actually giving this a
> spin as soon as it is available. Which obviously leads to the question when it
> will be available (2-3 months I guess) and how to get it usable on a NetBSD
> build.

 I would suggest that you try GCC 11.1 right away (which has been already 
released, as from Apr 27th) to see how it performs, and shake out any 
issues that you can and report ones you cannot (I'd be glad to help with 
anything on the GCC side).  This may well take those 2-3 months as I 
predicted earlier on in this discussion.

 Once you're happy with the results you can switch to 11.2, which is going 
to be very similar to 11.1, as for the release branches only regression 
fixes and documentation updates are normally accepted (I have only got a 
backport of my improvement accepted on the basis of being contained in a 
non-mainstream backend, being useful for a compiler part scheduled for 
removal with version 12, and to make it easier for NetBSD to use it right 
away).  So whatever works for and with 11.1 is expected to continue doing 
so with 11.2 (and any unlikely regression can be easily bisected).

 Lizzie tells me she has GCC version 7.4.0, and if it doesn't work as the 
first-stage compiler for a native GCC 11 bootstrap, then you may have to 
use a non-VAX system (possibly a NetBSD one if you like) to build a VAX 
cross-compiler, use it to cross-build a native compiler, carry the native 
compiler over to your VAX system (or use NFS to access it; the GCC driver 
will use relative paths to access executables, headers and libraries, so 
it doesn't have to be installed/mounted in any particular directory as 
long as the subtree structure is consistent), and then use it to fully 
bootstrap a native compiler on the VAX machine.

 Remember to always match compiler versions across all stages of the 
build, except for native bootstraps, so you may find yourself in a need to 
natively bootstrap GCC 11 on your non-VAX system first!  (I actually have 
this step included in my VAX verification, although I stop at building a 
VAX cross-compiler.)

 You can use the `contrib/download_prerequisites' script included with GCC 
sources to automatically download and symlink auxiliary library sources 
needed to build GCC if any respective versions already installed in the 
system turn out too old (GCC's `configure' script will bail out in that 
case).  Run it from within the top-level GCC source directory and then the 
`configure' script will pick them up automatically.

 Let me know if you get stuck at any stage and I'll try to help.

  Maciej