Re: Mark all GUC variable as PGDLLIMPORT

On Sun, Aug 22, 2021 at 09:29:01PM +0800, Julien Rouhaud wrote:
> On Sun, Aug 22, 2021 at 09:19:42AM -0400, Tom Lane wrote:
> > 
> > Uh, no, it's exactly *not* clear.  There are a lot of GUCs that are only
> > of interest to particular subsystems.  I do not see why being a GUC makes
> > something automatically more interesting than any other global variable.
> > Usually, the fact that one is global is only so the GUC machinery itself
> > can get at it, otherwise it'd be static in the owning module.
> > 
> > As for "extensions should be able to get at the values", the GUC machinery
> > already provides uniform mechanisms for doing that safely.  Direct access
> > to the variable's internal value would be unsafe in many cases.
> 
> Then shouldn't we try to prevent direct access on all platforms rather than
> only one?

Agreed.  If Julian says 99% of the non-export problems are GUCs, and we
can just export them all, why not do it?  We already export every global
variable on Unix-like systems, and we have seen no downsides.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  If only the physical world exists, free will is an illusion.