From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
cc: Pavel Raiskup <praiskup@redhat.com>,
        PostgreSQL Hacker <pgsql-hackers@postgresql.org>, devrim@gunduz.org
Subject: Re: plruby: rb_iterate symbol clash with libruby.so
In-reply-to: <20181103183040.jj7gp2zszusnea2d@alap3.anarazel.de>
References: <4738198.8KVIIDhgEB@nb.usersys.redhat.com>
 <20461.1541269186@sss.pgh.pa.us>
 <20181103183040.jj7gp2zszusnea2d@alap3.anarazel.de>
Comments: In-reply-to Andres Freund <andres@anarazel.de>
	message dated "Sat, 03 Nov 2018 11:30:40 -0700"
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Content-ID: <21250.1541270385.1@sss.pgh.pa.us>
Date: Sat, 03 Nov 2018 14:39:45 -0400
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Andres Freund <andres@anarazel.de> writes:
>> Pavel Raiskup <praiskup@redhat.com> writes:
>>> Is it realistic we could rename red-black tree methods from 'rb_*' to e.g.
>>> 'rbt_*' to avoid this clash?

> ISTM this specific case we could solve the issue by opening plruby.so /
> extension sos with RTLD_DEEPBIND.  That doesn't work if ruby extensions
> that are loaded later use rb_iterate, but should work for the case above.

Doesn't work on non-glibc platforms, though.

> On 2018-11-03 14:19:46 -0400, Tom Lane wrote:
>> That's not terribly appetizing, because it essentially means we're giving
>> Ruby (and potentially every other library on the planet) veto power over
>> our function namespace.  That does not scale, especially not when the
>> feedback loop has a time constant measured in years :-(
>> I don't have a huge objection to renaming the rbtree functions, other
>> than the precedent it sets ...

> I don't mind the precedent that much, but isn't that also not unlikely
> to break other extensions that use those functions?

I rather doubt there are any.  Also, if there are, the RTLD_DEEPBIND
solution would break them too, no?

			regards, tom lane