If you don't follow the standard, gcc -O2 can introduce bugs to your code that you never even wrote. Skipping null checks, executing both branches of a conditional, and so on.

▲

jstimpfle an hour ago | parent [-]

Where did I say I'm not following the standard?

▲

Xirdus an hour ago | parent [-]

I interpreted these words:

> If you want to be standards correct, yes you have to know the standard well.

to mean that being standards-correct is optional. It's not. Every C programmer needs to know every possible UB by heart and never introduce any of it to their code, or else they'll be constantly introducing subtle, hard to debug bugs that contradict the actual code they wrote.

Maybe you meant something different by those words, but then I'm confused what the "if" was supposed to mean.

	▲	jstimpfle 3 minutes ago \| parent [-]
		Of course it's optional (although I didn't mean to imply that). Even using computers at all is optional. I never said that I don't aim to follow the standard, have a clean compiling program without warnings and without UB, etc. I do strive to achieve all of that. But it's not entirely black and white, either. In practice I'm fine accepting that some bugs are technically UB but whatever, we've found a bug by whatever manifestation (like NULL derference most likely leading to segfault in practice). I just fix the bug as a bug, and life goes on.