Introduce PG_MODULE_MAGIC_EXT macro.
This macro allows dynamically loaded shared libraries (modules) to
provide a wired-in module name and version, and possibly other
compile-time-constant fields in future. This information can be
retrieved with the new pg_get_loaded_modules() function.
This feature is expected to be particularly useful for modules
that do not have any exposed SQL functionality and thus are
not associated with a SQL-level extension object. But even for
modules that do belong to extensions, being able to verify the
actual code version can be useful.
Author: Andrei Lepikhov <lepihov@gmail.com>
Reviewed-by: Yurii Rashkovskii <yrashk@omnigres.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/
dd4d1b59-d0fe-49d5-b28f-
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