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From: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: QEMU Developers <qemu-devel@nongnu.org>,
	Richard Henderson <rth@twiddle.net>,
	Knut Omang <knut.omang@oracle.com>
Subject: Re: [Qemu-devel] packed structures and unaligned accesses (sparc)
Date: Tue, 28 Mar 2017 12:19:55 +0200	[thread overview]
Message-ID: <1b4e550d-2a0a-e155-c78e-d6fd0a87cc08@physik.fu-berlin.de> (raw)
In-Reply-To: <CAFEAcA-t7xRo-2CkipmYKE_vUxp8oUBML8ss7G8U_pVhM79H6w@mail.gmail.com>

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:~#

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz@debian.org
`. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

  parent reply	other threads:[~2017-03-28 10:20 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-27 17:34 [Qemu-devel] packed structures and unaligned accesses (sparc) Peter Maydell
2017-03-27 21:43 ` Richard Henderson
2017-03-27 22:13 ` John Paul Adrian Glaubitz
2017-03-28 10:19 ` John Paul Adrian Glaubitz [this message]
2017-03-28 10:23   ` Peter Maydell

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