Re: LLVM 16 (opaque pointers)

On Thu, Oct 19, 2023 at 1:06 AM Thomas Munro <thomas(dot)munro(at)gmail(dot)com> wrote:
> On Thu, Oct 19, 2023 at 12:02 AM Thomas Munro <thomas(dot)munro(at)gmail(dot)com> wrote:
> > I pushed the first patch, for LLVM 16, and the build farm told me that
> > some old LLVM versions don't like it. The problem seems to be the
> > function LLVMGlobalGetValueType(). I can see that that was only added
> > to the C API in 2018, so it looks like I may need to back-port that
> > (trivial) wrapper into our own llvmjit_wrap.cpp for LLVM < 8.
>
> Concretely something like the attached should probably fix it, but
> it'll take me a little while to confirm that...

Pushed, after digging up some old LLVM skeletons to test, and those
"old LLVM" animals are turning green now. I went ahead and pushed the
much smaller and simpler patch for LLVM 17.

Interestingly, a new problem just showed up on the the RHEL9 s390x
machine "lora", where a previously reported problem [1] apparently
re-appeared. It complains about incompatible layout, previously
blamed on mismatch between clang and LLVM versions. I can see that
its clang is v15 from clues in the conflig log, but I don't know which
version of LLVM is being used. However, I see now that --with-llvm
was literally just turned on, so there is no reason to think that this
would have worked before or this work is relevant. Strange though --
we must be able to JIT further than that on s390x because we have
crash reports in other threads (ie we made it past this and into other
more advanced brokenness).

[1] https://www.postgresql.org/message-id/flat/20210319190047.7o4bwhbp5dzkqif3%40alap3.anarazel.de#ec51b488ca8eac8c603d91c0439d38b2