Re: Should contrib modules install .h files?

On 2 July 2018 at 02:23, Andrew Gierth <andrew@tao11.riddles.org.uk> wrote:

So I have this immediate problem: a PGXS build of a module, specifically
an hstore transform for a non-core PL, is much harder than it should be
because it has no way to get at hstore.h since that file is never
installed anywhere.

Should that be changed?

I think there's agreement in the thread that it should, and strong +1 from me.

I just wanted to pipe up with something Petr pointed out during pglogical development, which is that Pg offers a handy tool to help extensions link up with each other - find_rendezvous_variable(...) from dfmgr.c / fmgr.h . 

It's a real shame it's not more visible in contrib/ examples and the docs. Any suggestions on where it should appear in the docs? Somewhere in extend.sgml, presumably.

You still need a header from the other extension to *use* it, but it provides a massively easier way to find a struct of API function pointers. Prior to using it, I had a hack where I dlopen()ed the other shared library directly, and I'd also trialled using the fmgr to call a 'returns internal' function to get the API pointers struct that way.

--

 Craig Ringer                   http://www.2ndQuadrant.com/
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