From owner-freebsd-arch@FreeBSD.ORG  Wed May  9 09:59:40 2007
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Date: Wed, 9 May 2007 19:59:37 +1000 (EST)
From: Bruce Evans <bde@zeta.org.au>
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To: Julian Elischer <julian@elischer.org>
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Cc: Kostik Belousov <kostikbel@gmail.com>,
	Hans Petter Selasky <hselasky@c2i.net>,
	Giorgos Keramidas <keramida@FreeBSD.org>, freebsd-arch@FreeBSD.org
Subject: Re: Missing LIST_PREV() ?
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On Tue, 8 May 2007, Julian Elischer wrote:

> Kostik Belousov wrote:
>> On Tue, May 08, 2007 at 11:28:25AM -0400, John Baldwin wrote:

>>> I'm not sure how portable offsetof() would be though.  In general if you 
>>> want 
>> 
>> offsetof() itself is defined by C standard to be present both in
>> freestanding and hosted environment (and be available by stddef.h).
>
> You learn something every day! interesting (but still scary)..

Quite a lot of standard headers are required to be present in freestanding
environments: float.h, iso646.h, limits.h, stdarg.g, stdbool.h, stddef.h
and stdint.h.  Of course, these aren't required to have their usual
extensions and pollution (e.g., POSIX limits in limits.h), but just things
like INT_MAX which don't depend on the library.

offsetof() isn't usable in sys/queue.h, but sys/queue.h already uses
the equivalent __offsetof() for similar purposes.

Bruce