Re: [PATCH] Skip llvm bytecode generation if LLVM is missing

At Wed, 11 Mar 2020 12:43:22 -0700, Andres Freund <andres(at)anarazel(dot)de> wrote in
> Hi,
>
> On 2020-03-11 11:25:28 +0800, Craig Ringer wrote:
> > I propose that per the attached patch PGXS should simply skip adding
> > the automatic dependency for .bc files if clang cannot be found.
> > Extensions may still choose to explicitly declare the rule in their
> > own Makefile if they want to force bitcode generation.
>
> Hm, that seems like it could also cause silent failures (e.g. after a
> package upgrade or such).
>
> How about erroring out, but with an instruction that llvm can be
> disabled with make NO_LLVM=1 or such?

+1 for requiring such options for the same reason. The current patch
disables LLVM for the enviroment where clang is installed but ccache
is not, while building an extension based on postgresql-devel package.
(ccache is in EPEL on RHEL/CentOS.)

A bit aside from LLVM itself, I'd like CC/CPP/CLANG to fall back to
them in the PATH on the running environment if they don't exist.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center