Re: adding 'zstd' as a compression algorithm

Hi,

On 2022-02-17 13:34:08 +0900, Michael Paquier wrote:
> %define needs to include HAVE_LIBZSTD, HAVE_ZSTD_H and USE_ZSTD, so
> this version fails the sanity check between pg_config.h.in and the
> MSVC scripts checking that all flags exist.

Do we really need all three defines? How about using AC_CHECK_HEADER() instead
of AC_CHECK_HEADERS()? That wouldn't define HAVE_ZSTD_H. Cases where we error
out if a header isn't found make it a bit pointless to then still define
HAVE_*_H.  Plenty other cases in configure.ac just use AC_CHECK_HEADER.

Greetings,

Andres Freund