On Mon, Jun 22, 2015 at 2:55 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Piotr Stefaniak <postg...@piotr-stefaniak.me> writes: >> There are two places in parse_func.c where memcmp() conditionally gets a >> NULL as its first argument, which invokes undefined behavior. I guess >> gcc -O2 will make some assumptions based on memcpy's __nonnull attribute. > > If I recall that code correctly, the assumption was that if the third > argument is zero then memcmp() must not fetch any bytes (not should not, > but MUST not) and therefore it doesn't matter if we pass a NULL. Are > you seeing any observable problem here, and if so what is it?
I dunno, this seems like playing with fire to me. A null-test would be pretty cheap insurance. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
