Re: LLVM 16 (opaque pointers)

On Sun, Oct 22, 2023 at 2:44 PM Thomas Munro <thomas.munro@gmail.com> wrote:
> On Sat, Oct 21, 2023 at 2:45 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> > Thomas Munro <thomas.munro@gmail.com> writes:
> > > (It'd be nice if the
> > > build farm logged "$LLVM_CONFIG --version" somewhere.)
> >
> > It's not really the buildfarm script's responsibility to do that,
> > but feel free to make configure do so.
>
> Done, copying the example of how we do it for perl and various other things.

Build farm measles update:

With that we can see that nicator (LLVM 15 on POWER) is green.  We can
see that cavefish (LLVM 6 on POWER) is red as expected.  We can also
see that bonito (LLVM 7 on POWER) is red, so my earlier theory that
this might be due to the known bug we got fixed in LLVM 7 is not
enough.  Maybe there are other things fixed on POWER somewhere between
those LLVM versions?  I suspect it'll be hard to figure out without
debug builds and backtraces.

One thing is definitely our fault, though.  xenodermus shows failures
on REL_12_STABLE and REL_13_STABLE, using debug LLVM 6 on x86.  I
couldn't reproduce this locally on (newer) debug LLVM, so I bugged
Andres for access to the host/libraries and chased it down.  There is
some type punning for a function parameter REL_13_STABLE and earlier,
removed by Andres in REL_14_STABLE, and when I back-patched my
refactoring I effectively back-patched a few changes from his commit
df99ddc70b97 that removed the type punning, but I should have brought
one more line from that commit to remove another trace of it.  See
attached.