Re: [PATCH] C undefined behavior fix

Richard Henderson
2002-01-02T21:38:04Z

On Wed, Jan 02, 2002 at 12:09:10PM -0700, Tom Rini wrote:
> 2) Add -ffreestanding to the CFLAGS of arch/ppc/kernel/prom.o (If this
> optimization comes back on with this flag later on, it would be a
> compiler bug, yes?)

No. You still have the problem of using pointer arithmetic past
one past the end of the object.

C99 6.5.6/8:

If both the pointer operand and the result point to elements of the
same array object, or one past the last element of the array object,
the evaluation shall not produce an overflow; otherwise, the behavior
is undefined.

r~