On 2013-01-11 15:52:19 -0500, Tom Lane wrote: > Andres Freund <and...@2ndquadrant.com> writes: > > On 2013-01-11 15:05:54 -0500, Tom Lane wrote: > >> And another thing: what if the elevel argument isn't safe for multiple > >> evaluation? No such hazard ever existed before these patches, so I'm > >> not very comfortable with adding one. (Even if all our own code is > >> safe, there's third-party code to worry about.) > > > Hm. I am not really too scared about those dangers I have to admit. > > I agree the scenario doesn't seem all that probable, but what scares me > here is that if we use "__builtin_constant_p(elevel) && (elevel) >= ERROR" > in some builds, and just "(elevel) >= ERROR" in others, then if there is > any code with a multiple-evaluation hazard, it is only buggy in the > latter builds. That's sufficiently nasty that I'm willing to give up > an optimization that we never had before 9.3 anyway.
Well, why use it at all then and not just rely on __builtin_unreachable() in any recent gcc (and llvm fwiw) and abort() otherwise? Then the code is small for anything recent (gcc 4.4 afair) and always consistently buggy. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
