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Date: Mon, 5 Mar 2012 13:49:38 +0000
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From: Peter Maydell <peter.maydell@linaro.org>
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Subject: Re: [Qemu-devel] [PATCH] osdep: Remove local definition of macro
	offsetof
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To: =?UTF-8?Q?Andreas_F=C3=A4rber?= <afaerber@suse.de>
Cc: qemu-trivial <qemu-trivial@nongnu.org>, Stefan Weil <sw@weilnetz.de>, qemu-devel@nongnu.org

On 5 March 2012 13:23, Andreas F=C3=A4rber <afaerber@suse.de> wrote:
> Am 05.03.2012 07:22, schrieb Stefan Weil:
>> The macro offsetof is defined in stddef.h. It is conforming to
>> the standards C89, C99 and POSIX.1-2001 (see man page), so it
>> is a sufficiently old standard.
>>
>> Therefore chances are very high that QEMU never needs a local
>> definition of this macro.

> Did you check when this was introduced and whether the commit message
> gave any explanation why?

It's been copied and moved around and rerationalised down to one
definition since then, but the first offsetof() definition was
added by Fabrice in fd6ce8f66 in May 2003, with no particular
comment about it. That is about as close as qemu gets to "it has
always been this way" :-)

Nearly a decade on, I think dropping it is probably reasonably
safe.

-- PMM