Re: [Qemu-devel] [PATCH v6 1/5] qobject: ensure base is at offset 0

[Eric Blake <eblake@redhat.com>]

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On 04/19/2018 10:01 AM, Marc-André Lureau wrote:
> All QObject types have the base QObject as their first field. This
> allows the simplification of qobject_to().
> 
> This explicitly guarantees that existing casts work correctly (even
> though we'd prefer to get rid of such casts in any location except the
> qobject.h macros)
> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>

My R-b stands that this is correct from a coding point of view.  But if
I read Markus' review correctly, we could omit this patch, fix the one
broken client in tests/check-qdict.c to use qobject_to() (why didn't you
fix that in v6)?, and then just apply patches 2-5 without this patch,
with no change in behavior and where we are no longer dependent on using
offset 0 (even though all current instances do).  So, I'll leave that to
maintainer discretion.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


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