Re: Add PGDLLIMPORT lines to some variables

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On Mon, Dec 4, 2017 at 5:41 PM, Noah Misch <noah(at)leadboat(dot)com> wrote:
>> I don't think we quite have an established protocol for this. I
>> personally, but I'm biased in this specific case, is that we should
>> adopt a position that PGDLLIMPORTs should basically backpatched whenever
>> a credible extension even halfway reasonably requires it. There's no
>> easy way to get this done by default, and we're so far unwilling to just
>> slap this onto every variable. So to not further disadvantage people
>> force dto live in the MS environment, that seems the sanest
>> solution. It's not like these are high risk.
>
> +1

If that's going to be the policy, then I have some requests of my own.
I would like to add some PGDLLIMPORTs to suit the external version of
amcheck (the version that targets earlier versions of Postgres). These
are:

RecentGlobalXmin -- This is only PGDLLIMPORT on Postgres 10+,
following commit 56018bf2. I'd like to get that back to 9.4, although
there is no reason to not include 9.3.

TransactionXmin -- This is needed for the newer heap-matches-index
verification check. Again, I would like this on 9.4+, but 9.3+ works
too.

Note that somebody asked about running it on Windows recently, and on
one other occasion in the past. It does come up.

--
Peter Geoghegan