[PATCH] C undefined behavior fix
Florian Weimer
fw@deneb.enyo.de
Fri Jan 4 01:07:00 GMT 2002
Tom Rini <trini@kernel.crashing.org> writes:
> 1) Change this particular strcpy to a memcpy
That doesn't fix the undefined behavior.
> 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?)
That doesn't fix the undefined behavior.
> 3) Modify the RELOC() marco in such a way that GCC won't attempt to
> optimize anything which touches it [1]. (Franz, again by Jakub)
That *does* fix the undefined behavior, and it seems that GCC is going
to stay the same in the future, so this is a feasible workaround.
> 4) Introduce a function to do the calculations [2]. (Corey Minyard)
That doesn't fix the undefined behavior.
> 5) 'Properly' set things up so that we don't need the RELOC() macros
> (-mrelocatable or so?), and forget this mess altogether.
This is the clean approach, and thus preferable in the long term. (3)
seems to be the best short-time solution.
More information about the Gcc
mailing list