I am such a pedant.

So

I decided to rid my world of warnings.

Never more will a NULL and a 0 be used incorrectly!

Actually, I did this ages ago for the VSTs and AUs. Leave warnings ALL on, tidy the thing up.
That's another reason to like VST... there's nothing implicitly wrong with the code; it doesn't throw up many errors... and, yes, I did fix the handful that it did.
AU- same deal; nice clean code.

AUs and VSTs have been building clean for ever.

RTAS is a different story. RTAS was throwing up ~1200 warnings. Mostly (almost all) warnings of nonvirtual destructors in classes with virtual functions. This is a violation of the "effective C++" rules. However, it's meant to be that way. It's correct, for a variety of reasons, for the digi classes to have nonvirtual destructors alongside virtual functions. So.. just disable the warning for that file, right? GCC doesn't do that yet. Ugh.
Disable the destructor warning? You know the code is otherwise clean... No. -Wmost switches it back on somehow. I've never really understood XCode's build system. Well; I think I do, it's an inherited overridable system, and as such it's pretty straightforward. But, it IS magic when things start to interact within the compiler. Or just plain lie to you.

Anyway. I switched off -Wmost, and was suddenly left with a sensible set of warnings!
Entire build is now warning free.

I'm a pedant, but I do rock ;)