Re: JIT works only partially with meson build?

On Fri, 2025-06-27 at 16:19 +0900, Yugo Nagata wrote:
> On Mon, 26 May 2025 19:17:53 +1200
> David Rowley <dgrowleyml@gmail.com> wrote:
>
> > On Mon, 26 May 2025 at 18:08, Yugo Nagata <nagata@sraoss.co.jp> wrote:
> > > While building PostgreSQL 17 on Windows, I noticed bitcode files (.bc) are not
> > > generated with meson. Does this means that "inlining" of JIT doesn't
> > > work when PostgreSQL is build with meson?
> >
> > Yes.  I believe [1] aims to fix this.
> >
> > [1] https://commitfest.postgresql.org/patch/5671/
>
> Thank you for the clarification.
>
> I've attached a patch to update the documentation.
> I believe it's worth stating this explicitly, since the fix will not be
> applied until at the earliest PostgreSQL 19.

I think that it is a good idea to document this lack of functionality.

One thing stood out to me:

> --- a/doc/src/sgml/jit.sgml
> +++ b/doc/src/sgml/jit.sgml
> @@ -36,7 +36,8 @@
>     <acronym>JIT</acronym> compilation using <ulink
>     url="https://llvm.org/"><productname>LLVM</productname></ulink> when
>     <productname>PostgreSQL</productname> is built with
> -   <link linkend="configure-with-llvm"><literal>--with-llvm</literal></link>.
> +   <link linkend="configure-with-llvm"><literal>--with-llvm</literal></link>
> +   or <link linkend="configure-with-llvm-meson"><option>-Dllvm</option></link>.

You used the <option> tag, which I believe is correct, but the surrounding
code uses <literal>.  I don't think it renders differently, but I think it
would be good to use the same tag.  I suggest that you change the
surrounding code to use <option> as well.

v18 is already shipped, and we don't know if the patch to produce bitcode
with Meson will make v19 or not.  Consequently, I don't know if we should
apply the patch to git HEAD yet.  But I believe that it should be
backpatched to all older releases, since this is a shortcoming in the
documentation.

Yours,
Laurenz Albe