Re: plpgsql_check_function - rebase for 9.3

"Petr Jelinek" <pjmodos@pjmodos.net> writes:
>> What exactly do you have in mind there?  The way we load extensions, they
>> can't (AFAIK) see each other's defined symbols, so you couldn't really make
>> an independent extension that would call functions in plpgsql.  This is not
>> really open for debate, either, as changing that would risk creating symbol
>> collisions between modules that never had to worry about polluting global
>> namespace before.

> I can call functions that are exported by plpgsql.so just fine from
> different extension now, I just have to preload the plpgsql.so (via LOAD or
> guc) first, so I don't see what is the problem here.

[ pokes around... ]  Hm, it appears that that does work on Linux,
because for some reason we're specifying RTLD_GLOBAL to dlopen().
TBH that seems like a truly horrid idea that we should reconsider.
Aside from the danger of unexpected symbol collisions between
independent loadable modules, I seriously doubt that it works like
that on every platform we support --- so I'd be very strongly against
accepting any code that depends on this working.
        regards, tom lane