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From: Rui Paulo <rpaulo@FreeBSD.org>
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Date: Sun, 6 Nov 2011 16:47:38 -0800
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To: Warner Losh <imp@bsdimp.com>
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Cc: Alexander Best <arundel@FreeBSD.org>, freebsd-toolchain@FreeBSD.org,
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Subject: Re: [poc] buildkernel + clang + -Werror
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On Nov 6, 2011, at 4:36 PM, Warner Losh wrote:

> On Nov 6, 2011, at 2:13 PM, Rui Paulo wrote:
>> The only argument against this tautological check that I agree with =
is when the code is explicitly trying to be safe. If the developer =
checks for "i < 0" when indexing an array he/she is trying to guard =
against possible pitfalls in the future when someone suddenly decides to =
change the variable type to become signed. One possible security =
vulnerability was avoided because that developer checked for negative =
values.
>> I'm against turning this off by default, but it should not cause an =
error.
>=20
> Except when you pass args back and forth between signed and unsigned =
and back again.  If you check < 0 in the middle, that's one more =
security bug you thought you had fixed, but really you've done nothing =
with.


Of course, but in the context of the compiler checks this argument =
doesn't apply.

Regards,
--
Rui Paulo