Re: plruby: rb_iterate symbol clash with libruby.so

Pavel Raiskup <praiskup(at)redhat(dot)com> writes:
> On Monday, November 5, 2018 9:06:41 PM CET Robert Haas wrote:
>> On Sat, Nov 3, 2018 at 2:20 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>>> Is it realistic we could rename red-black tree methods from 'rb_*' to e.g.
>>>> 'rbt_*' to avoid this clash?

>>> I don't have a huge objection to renaming the rbtree functions, other
>>> than the precedent it sets ...

>> Maybe prefixing with pg_ would better than rb_ to rbt_. ...
>> It's certainly not very surprising that Ruby has symbols starting with
>> rb_...

> I now realized that there's rb_block_call() alternative for rb_iterate()
> Ruby call -- which fortunately doesn't collide with PostgreSQL internals.
> It means that for sufficiently new Ruby there exists some solution (not
> that something similar can not re-appear elsewhere).

Yeah. The long and short of this is that we're trampling on namespace
that reasonably belongs to Ruby --- if they had some functions named
"pg_something" and complained about a collision with libpq, would we
change? Nope. So really we should rename these.

After looking at the code a bit I like the idea of s/rb/rbt/g
better than s/rb/pg_rb/g. The latter seems verbose, and it would
also open the question of whether we need to rename rbtree.h/.c,
which would be an additional level of complication I don't want.
The rbt approach will allow skipping some other renamings that
would be needed for consistency if we use pg_rb.

Barring objections I'll go make this happen shortly.

It's too late for this week's releases, but Pavel could pick up the commit
once it happens and carry it as a Fedora patch until the next releases.

regards, tom lane