From: Eric Blake <eblake@redhat.com>
To: "Daniel P. Berrangé" <berrange@redhat.com>,
"Vladimir Sementsov-Ogievskiy" <vsementsov@virtuozzo.com>
Cc: kwolf@redhat.com, fam@euphon.net, qemu-block@nongnu.org,
qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com
Subject: Re: [RFC (fix for 5.0?)] block/io: do not do pointer arithmetic on void *
Date: Wed, 18 Mar 2020 09:39:01 -0500 [thread overview]
Message-ID: <bd88b8eb-d4d2-cd53-f61a-7fab95f28812@redhat.com> (raw)
In-Reply-To: <20200318142654.GH2173309@redhat.com>
On 3/18/20 9:26 AM, Daniel P. Berrangé wrote:
> On Wed, Mar 18, 2020 at 05:22:53PM +0300, Vladimir Sementsov-Ogievskiy wrote:
>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>> ---
>>
>> Hi all!
>>
>> C standard doesn't allow pointer arithmetic on void *.
>> Still, gcc allows it as an extension:
>> https://gcc.gnu.org/onlinedocs/gcc-4.8.0/gcc/Pointer-Arith.html
>>
>> I can create a series of patches like this. Do we need it?
>
> I don't think so, we only care about gcc & clang.
Still, if all supported compilers support the extension, then our
CODING_STYLE.rst should mention that it is safe to rely on the extension.
>
>> Also, where is documented which compilers are supported by Qemu?
>
> It is checked in configure - gcc 4.8 or clang 3.4 or xcode clang 5.1
>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
next prev parent reply other threads:[~2020-03-18 14:44 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-18 14:22 [RFC (fix for 5.0?)] block/io: do not do pointer arithmetic on void * Vladimir Sementsov-Ogievskiy
2020-03-18 14:26 ` Daniel P. Berrangé
2020-03-18 14:39 ` Eric Blake [this message]
2020-03-20 16:08 ` Stefan Hajnoczi
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