From: John Keeping <john@keeping.me.uk>
Date: Wed, 16 Jan 2013 23:08:00 GMT
Subject: Re: [PATCH 1/2] fix clang -Wconstant-conversion with bit fields
Message-ID: <20130116230800.GB4574@serenity.lan>
In-Reply-To: <1358376443-7404-1-git-send-email-apelisse@gmail.com>

On Wed, Jan 16, 2013 at 11:47:22PM +0100, Antoine Pelisse wrote:
> clang incorrectly reports a constant conversion warning (implicit
> truncation to bit field) when using the "flag &= ~FLAG" form, because
> ~FLAG needs to be truncated.
> 
> Convert this form to "flag = flag & ~FLAG" fixes the issue as
> the right operand now fits into the bit field.
> 
> Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
> ---
> I'm sorry about this fix, it really seems bad, yet it's one step closer
> to warning-free clang compilation.
> 
> It seems quite clear to me that it's a bug in clang.

Which version of clang did you see this with?  I don't get these
warnings with clang 3.2.


John