[PATCH] C undefined behavior fix

[Joe Buck]

VANDROVE@vc.cvut.cz said:
> > (and for CONSTANT < 5 it of course generated correct code to fill dst
> > with string contents; and yes, I know that code will sigsegv on run
> > because of dst is not initialized - but it should die at runtime, not
> > at compile time). 
> 
> An ICE, while it's not quite what was expected and it'll probably get fixed,
> is nonetheless a perfectly valid implementation of 'undefined behaviour'.

Not for GCC it isn't.  Our standards say that a compiler crash, for any
input whatsoever, no matter how invalid (even if you feed in line noise),
is a bug.  Other than that we shouldn't make promises, though the old gcc1
behavior of trying to launch a game of rogue or hack when encountering a
#pragma was cute.