Re: Cannot find a working 64-bit integer type on Illumos

On Thu, Dec 5, 2024 at 12:16 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Now you already snuck the camel's nose under the
> tent by including stdint.h there, and maybe these additional headers
> wouldn't do any further damage.

Even though we fixed the immediate issue (thanks), this comment stayed
with me. I did that because I didn't want to change any interfaces at
the same time as the <stdint.h> retrofit, but I agree that it feels a
bit odd hidden in there, and doesn't appear to conform to
postgres_ext.h's self-description. Stepping back, and I realise it's
difficult to answer with certainty, I wonder why anyone would ever
want to use postgres_ext.h directly for the definition of pg_int64
*without* being a user of libpq-fe.h. I can't find any references to
pg_int64 (excluding forks of our code) on github; there are a few
things like proxies and suchlike that include postgres_ext.h for other
things, mostly bogusly (they also include libpq-fe.h, or they say they
want NAMEDATALEN, which isn't there anymore).

We have just three lo_*64() functions using that type and then
pg_usec_time_t. Seems like a very narrow usage that hasn't spread,
likely only used to receive arguments, and really quite specific to
libpq-fe.h and not one of the "fundamental Postgres declarations".
Maybe we should consider moving #include <stdint.h> into libpq-fe.h?

And if we included <stdint.h> overtly, rather than covertly in
postgres_ext.h, why would we still want a third name for int64_t? We
could change the three lo_*64() declarations to use the standard type
directly, but keep the historical typedef marked deprecated.

> But I don't see a strong argument to
> change long-standing external APIs any more than we absolutely must.

So perhaps you'll hate that idea then. I wonder if you'll hate it
more than keeping the #include in postgres_ext.h, hence putting the
idea forward!