Re: [PATCH] C undefined behavior fix

[Richard Henderson <rth at redhat dot com>]

On Fri, Jan 04, 2002 at 03:30:39PM -0800, Linus Torvalds wrote:
> Ie an implementation can NOT just say "our implementation-defined
> behaviour for X is undefined behaviour". That's not documenting anything.

Why not?  It documents that You Can't Do That.

> I realize that gcc internally doesn't know about the distinction after a
> certain point, but if gcc doesn't know, then gcc has to assume the worst.

You will _not_ like the code you'll get out of gcc if we turn off
looking through PLUS.  Which I don't even know how to do -- that
sort of thing is scattered all over the compiler.

I will at this point give up on this disagreement.  On a practical
level, even if I were to concede your point (which I don't) there
is absolutely nothing that can be done without starting over from
scratch with another compiler.


r~