------- Comment #15 from mark at codesourcery dot com 2010-04-20 22:18 -------
Subject: Re: [DR 1022] G++ is too aggressive in optimizing
away bounds checking with enums
jason at gcc dot gnu dot org wrote:
> Certainly optimizing away bounds checking is good when it is provably
> redundant, but that clearly doesn't apply to this case.
Do you think this is different from signed integer overflow in loops?
To me, it seems quite similar. That's a situation where the compiler
will now optimize away the check in something like "for (int i = 0; i >=
0; ++i)", leaving us with an infinite loop.
And, of course, that can hit you in a security context too.
/* Here we know that "i" is positive. */
...
if (i + 100 <= 0)
abort();
/* The check above will make sure this never overflows ...
<scaryvoice>or will it?</scaryvoice> */
i += 100;
> That said, I'll go ahead and add the option.
Thanks,
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43680
