Linux on VAX - Dead ?

[Maciej W. Rozycki]

On Sat, 14 Jan 2023, David Brownlee wrote:

> >  You are welcome.  Bugs in the compiler hindered progress with the
> > userland.  Chances are this updated GCC would work better.
> 
> The VAX gcc work is very much appreciated, and has kept NetBSD/vax
> from falling into non-viability. Hopefully NetBSD can continue to keep
> a light on in the back of *nix on VAX until someone has time to bring
> VAXlinux back up :)

 In principle I haven't abandoned the VAX/Linux effort, but reality may 
disagree.  We shall see.  My biggest obstacle has been the distraction 
coming from PSU failures (electrolytic capacitor leaks caused by improper 
chemistry) forcing me to focus on hardware repairs rather than software 
work.

> (On that note do you know if your latest work would be viable to back
> port to gcc-10 (NetBSD has yet to pull in later gcc :( )

 I'm not sure if backporting would be worth the effort, but anyone is free 
to of course.

 Coincidentally I have literally just ported `gdbserver' to VAX/NetBSD (in 
the course of handling GDB PR tdep/29804) and it has revealed what G++ 
testing has also shown, and specifically that GCC has broken exception 
handling with the VAX target, e.g.:

terminate called after throwing an instance of 'gdb_exception_quit'
terminate called recursively
Abort (core dumped)

It seems a preexisting problem given that I have observed similar traps 
with native VAX/NetBSD GDB 8.3 shipped with the distribution.  I think 
this has to be sorted before VAX/NetBSD switches to a newer version of GCC 
even if technically it's not a regression.

 I'll see what I can do to get this sorted with GCC 13 (and possibly 
backported), but note that Stage 3 ends literally today, so it may not be 
possible after all.

  Maciej