From: Paul Brook <paul@codesourcery.com>
To: qemu-devel@nongnu.org
Cc: Markus Armbruster <armbru@redhat.com>
Subject: Re: [Qemu-devel] container_of() vs DO_UPCAST() (was: [PATCH 2/3] Clean up upcast from PCIDevice to I6300State)
Date: Mon, 24 Aug 2009 12:55:13 +0100 [thread overview]
Message-ID: <200908241255.14045.paul@codesourcery.com> (raw)
In-Reply-To: <87ab1pvbov.fsf_-_@pike.pond.sub.org>
On Monday 24 August 2009, Markus Armbruster wrote:
> We got container_of() in osdep.h.
>
> We also got DO_UPCAST() in qdev.h. Odd place, as it's not really
> specific to qdev (except for the naming of the last parameter). It
> takes the same parameters as container_of(), but in a different order,
> which I find needlessly confusing. The last parameter is insufficiently
> parenthesized in the macro expansion. Finally, I don't really like the
> name --- I find container_of() much clearer --- but that's just me.
>
> Why do we have two macros to do essentially the same thing?
>
> When should container_of() be used, and when DO_UPCAST()?
DO_UPCAST requires that the child object be at offset zero.
Paul
next prev parent reply other threads:[~2009-08-24 11:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-21 8:31 [Qemu-devel] [PATCH 0/3] qdev: clean up & convert watchdogs Markus Armbruster
2009-08-21 8:31 ` [Qemu-devel] [PATCH 1/3] Move watchdog, watchdog_action, give them internal linkage Markus Armbruster
2009-08-21 8:31 ` [Qemu-devel] [PATCH 2/3] Clean up upcast from PCIDevice to I6300State Markus Armbruster
[not found] ` <m3ws4xt7up.fsf@neno.mitica>
2009-08-24 8:49 ` [Qemu-devel] container_of() vs DO_UPCAST() (was: [PATCH 2/3] Clean up upcast from PCIDevice to I6300State) Markus Armbruster
2009-08-24 11:55 ` Paul Brook [this message]
2009-08-24 11:59 ` [Qemu-devel] [PATCH 2/3] Clean up upcast from PCIDevice to I6300State Paul Brook
2009-08-24 13:44 ` Markus Armbruster
2009-08-24 15:07 ` Gerd Hoffmann
2009-08-21 8:31 ` [Qemu-devel] [PATCH 3/3] qdev: convert watchdogs Markus Armbruster
2009-08-21 13:07 ` Gerd Hoffmann
2009-08-24 9:05 ` Immutable qdev properties (was: [Qemu-devel] [PATCH 3/3] qdev: convert watchdogs) Markus Armbruster
2009-08-24 12:25 ` [Qemu-devel] Re: Immutable qdev properties Gerd Hoffmann
2009-08-24 13:04 ` Markus Armbruster
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