Re: pgsql: Track LLVM 15 changes.

On Fri, Dec 26, 2025 at 6:05 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Thomas Munro <thomas.munro@gmail.com> writes:
> > Shortly I'll do the back-patch of LLVM 14 API changes (their final
> > release tag is scheduled for tomorrow, as I've been reminded by
> > package maintainers trying and failing to build).  But I figured I
> > should also follow up on this bandaid solution to the API deprecation
> > warnings, that is, silencing them for now, so we don't spew screeds of
> > warnings.  Does someone have a better idea than the attached?
>
> The bit added by commit a56e7b660 is still there in
> src/backend/jit/llvm/Makefile:
>
> +# LLVM 14 produces deprecation warnings.  We'll need to make some changes
> +# before the relevant functions are removed, but for now silence the warnings.
> +ifeq ($(GCC), yes)
> +LLVM_CFLAGS += -Wno-deprecated-declarations
> +endif
>
> Surely we don't need this anymore?  I tried removing it locally
> and didn't see any such warnings (with Red Hat's llvm 20.1.8).

Yeah.  We should just delete these obsolete lines in 18 and master.
For older branches, I think it should be enough to update the comment
in 14-17, as attached.  We could work harder and suppress the warnings
only for LLVM 14 and 15 specifically in PostgreSQL 14-17, but it seems
like the main point is surely to have *something* watching out for new
warnings that are added in future LLVM versions, and we'll get that
from the newer branches.