From: Sverre Rabbelier <srabbelier@gmail.com>
Date: Thu, 10 Feb 2011 12:11:17 GMT
Subject: Re: [PATCH] compat: helper for detecting unsigned overflow
Message-ID: <AANLkTinqkSxj0C+GyMVR4a7d=yy_mh+oDuar0moZjZ8_@mail.gmail.com>
In-Reply-To: <20110210093536.GB365@elie>

Heya,

On Thu, Feb 10, 2011 at 10:35, Jonathan Nieder <jrnieder@gmail.com> wrote:
>        unsigned_add_overflows(a, b)

> Define such a macro, expanding roughly to ((a) < UINT_MAX - (b)).
> Because the expansion uses each argument only once outside of sizeof()
> expressions, it is safe to use with arguments that have side effects.

> +#define unsigned_add_overflows(a, b) \
> +    ((b) > maximum_unsigned_value_of_type(a) - (a))

I'm confused, you say you won't use it twice, and then you do use it twice?

-- 
Cheers,

Sverre Rabbelier