From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
cc: Michael Paquier <michael@paquier.xyz>, Stephen Frost <sfrost@snowman.net>,
        Andrew Gierth <andrew@tao11.riddles.org.uk>,
        pgsql-hackers@postgresql.org, Andres Freund <andres@anarazel.de>
Subject: Re: Should contrib modules install .h files?
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Comments: In-reply-to Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
	message dated "Mon, 23 Jul 2018 17:22:16 +0200"
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Date: Mon, 23 Jul 2018 12:12:30 -0400
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Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes:
> Also, let's recall that the point of this exercise is that you want to
> install the header files so that you can build things (another
> extension) that somehow interacts with those extensions.  Then, even if
> you put things in separate directories per extension, you still need to
> make sure that all the installed header files don't clash, since you'll
> be adding the -I options of several of them.  In a way, doing it this
> way will make things less robust, since it will appear to give extension
> authors license to use generic header names.

Personally, I'd recommend using *one* -I switch and having .c files
reference extension headers with #include "extensionname/headername.h".

As I said before, I think that we should change the existing contrib
modules to be coded likewise, all using a single -I switch that points
at SRCDIR/contrib.  That'd help give people the right coding model
to follow.

			regards, tom lane