Re: Mark all GUC variable as PGDLLIMPORT

On Fri, Aug 27, 2021 at 3:42 AM Magnus Hagander <magnus@hagander.net> wrote:
>
> Yeah, but that does move the problem to the other side doesn't it? So
> if you (as a pure test of course) were to remove the variable
> completely from the included header and just declare it manually with
> PGDLLSPEC in your file, it should work?
>
> Ugly as it is, I wonder if there's a chance we could just process all
> the headers at install times and inject the PGDLLIMPORT. We know which
> symvols it is on account of what we're getting in the DEF file.
>
> Not saying that's not a very ugly solution, but it might work?

It's apparently not enough.  I tried with autovacuum_max_workers GUC,
and it still errors out.
If I add a PGDLLIMPORT, there's a link error when trying to access the variable:
error LNK2019: unresolved external symbol __imp_autovacuum_max_workers
referenced in function...

I think that it means that msvc tries to link that to a DLL while it's
expected to be in postgres.lib as the __imp_ prefix is added in that
case.

If I use PGDLLEXPORT I simply get:
error LNK2001: unresolved external symbol aytovacuum_max_workers