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From: Peter Maydell <peter.maydell@linaro.org>
Date: Tue, 28 Mar 2017 11:23:14 +0100
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Subject: Re: [Qemu-devel] packed structures and unaligned accesses (sparc)
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To: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: QEMU Developers <qemu-devel@nongnu.org>, Richard Henderson <rth@twiddle.net>, Knut Omang <knut.omang@oracle.com>

On 28 March 2017 at 11:19, John Paul Adrian Glaubitz
<glaubitz@physik.fu-berlin.de> wrote:
> On 03/27/2017 07:34 PM, Peter Maydell wrote:
>> That all makes sense in isolation, but shouldn't something have
>> at least warned that "&h.size" isn't actually a uint32_t* in
>> the sense of being something you can validly pass to a
>> function that takes a uint32_t* ?
>
> It turns out that clang actually emits a warning in this case:
>
> root@deb4g:~# clang-4.0 packed.c -o packed
> packed.c:18:18: warning: taking address of packed member 'size' of class or structure 'hdr' may result in an unaligned pointer value
>       [-Waddress-of-packed-member]
>   return getval(&h.size);
>                  ^~~~~~
> 1 warning generated.
> root@deb4g:~#

Ah, good. (Unfortunately my clang isn't new enough for that,
being 3.8.)

thanks
-- PMM