Re: RISC-V animals sporadically produce weird memory-related failures

On Tue, Dec 3, 2024 at 7:00 AM Alexander Lakhin <exclusion@gmail.com> wrote:
> A build made with clang-19 without llvm passed `make check` successfully.

We heard in another thread[1] that we'd need to use the JITLink API
for RISCV, instead of the RuntimeDyld API we're using.  I have a newer
patch to use JITLink on all architectures, starting at some LLVM
version, but it needs a bit more polish and research before sharing.
I'm surprised it's segfaulting instead of producing an error of some
sort, though.  I wonder why.  It would be nice if we could fail
gracefully instead.

Hmm, from a quick look in the LLVM main branch, it looks like a bunch
of RISCV stuff just landed in recent months under
llvm/lib/ExecutionEngine/RuntimeDyld, so maybe that's not true anymore
on bleeding-edge LLVM (20-devel), I have no idea what state that's in,
but IIUC there is no way RuntimeDyld could work on LLVM 16 or 19.

[1] https://www.postgresql.org/message-id/flat/20220829074622.2474104-1-alex.fan.q%40gmail.com