On 2013-01-11 16:16:58 -0500, Tom Lane wrote: > Andres Freund <and...@2ndquadrant.com> writes: > > On 2013-01-11 15:52:19 -0500, Tom Lane wrote: > >> 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. > > Uh ... because it's *not* unreachable if elevel < ERROR. Otherwise we'd > just mark errfinish as __attribute((noreturn)) and be done. Of course, > that's a gcc-ism too.
Well, I mean with the double evaluation risk. 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
