On Tue, Jun 28, 2005 at 02:52:10PM -0400, Robert Dewar wrote: > Olivier Galibert wrote: > >On Tue, Jun 28, 2005 at 06:36:26PM +0100, Dave Korn wrote: > > > >> It certainly wasn't meant to be. It was meant to be a dispassionate > >>description of the state of facts. Software that violates the C standard > >>just *is* "buggy" or "incorrect", and your personal pride has absolutely > >>nothing to do with it. > > > > > >Then your definition of "incorrect" is uninteresting. Per your > >definition, "use of implementation-defined behaviour is incorrect", > >essentially no non-trivial program is correct. Including gcc for a > >start, which can't be correct, ever. > > Nope, there is nothing in the C standard that suggests that a program > relying on implementation-defined behavior is incorrect of buggy, and that > has nothing to do with what Dave Korn wrote. There is a world of > difference between undefined and implementation-defined.
Dave Korn wrote, in answer to a list of assumptions I wrote, that "There is a vast amount of bad software in the world, some blatantly buggy, some subtly-incorrect. To attempt to fix it all in the compiler rather than the source seems a bit bass-ackwards to me!" These assumptions were: - signed and unsigned types are modulo, except in loop induction variables where it's bad taste (to rely on the overflow doing anything specific) - sizeof(int) == 4, sizeof(long long) == 8 - sizeof(long) == sizeof(void *) == sizeof(void (*)()) Please tell me which of these assumptions are not implementation-defined but instead undefined. OG.
