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From: Warner Losh <imp@bsdimp.com>
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To: Rui Paulo <rpaulo@FreeBSD.org>
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Cc: Alexander Best <arundel@FreeBSD.org>, freebsd-toolchain@FreeBSD.org,
	Dimitry Andric <dim@FreeBSD.org>
Subject: Re: [poc] buildkernel + clang + -Werror
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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.

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.

Warner