From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from [140.186.70.92] (port=50793 helo=eggs.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1Oyr59-00018R-8E
	for qemu-devel@nongnu.org; Thu, 23 Sep 2010 15:03:48 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69)
	(envelope-from <weil@mail.berlios.de>) id 1Oyr57-0000bj-M8
	for qemu-devel@nongnu.org; Thu, 23 Sep 2010 15:03:47 -0400
Received: from moutng.kundenserver.de ([212.227.126.186]:64459)
	by eggs.gnu.org with esmtp (Exim 4.69)
	(envelope-from <weil@mail.berlios.de>) id 1Oyr57-0000aO-9h
	for qemu-devel@nongnu.org; Thu, 23 Sep 2010 15:03:45 -0400
Message-ID: <4C9BA48A.1090600@mail.berlios.de>
Date: Thu, 23 Sep 2010 21:03:38 +0200
From: Stefan Weil <weil@mail.berlios.de>
MIME-Version: 1.0
References: <1285267031-22966-1-git-send-email-weil@mail.berlios.de>
	<AANLkTikQJsfT4Xz_7yVF3suSoxZ+Rsz9RpADB0gT0Owc@mail.gmail.com>
In-Reply-To: <AANLkTikQJsfT4Xz_7yVF3suSoxZ+Rsz9RpADB0gT0Owc@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Subject: [Qemu-devel] Re: [PATCH] block: Use GCC_FMT_ATTR and fix a format
	error
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Blue Swirl <blauwirbel@gmail.com>
Cc: Kevin Wolf <kwolf@redhat.com>, QEMU Developers <qemu-devel@nongnu.org>

Am 23.09.2010 20:53, schrieb Blue Swirl:
> On Thu, Sep 23, 2010 at 6:37 PM, Stefan Weil<weil@mail.berlios.de>  wrote:
>    
>> Adding the gcc format attribute detects a format bug
>> which is fixed here.
>>
>> Cc: Blue Swirl<blauwirbel@gmail.com>
>> Cc: Kevin Wolf<kwolf@redhat.com>
>> Signed-off-by: Stefan Weil<weil@mail.berlios.de>
>> ---
>>   block/blkverify.c |    5 +++--
>>   1 files changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/block/blkverify.c b/block/blkverify.c
>> index 8083464..b39fb67 100644
>> --- a/block/blkverify.c
>> +++ b/block/blkverify.c
>> @@ -53,7 +53,8 @@ static AIOPool blkverify_aio_pool = {
>>      .cancel             = blkverify_aio_cancel,
>>   };
>>
>> -static void blkverify_err(BlkverifyAIOCB *acb, const char *fmt, ...)
>> +static void GCC_FMT_ATTR(2, 3) blkverify_err(BlkverifyAIOCB *acb,
>> +                                             const char *fmt, ...)
>>   {
>>      va_list ap;
>>
>> @@ -300,7 +301,7 @@ static void blkverify_verify_readv(BlkverifyAIOCB *acb)
>>      ssize_t offset = blkverify_iovec_compare(acb->qiov,&acb->raw_qiov);
>>      if (offset != -1) {
>>          blkverify_err(acb, "contents mismatch in sector %ld",
>> -                      acb->sector_num + (offset / BDRV_SECTOR_SIZE));
>> +                      (long)(acb->sector_num + (offset / BDRV_SECTOR_SIZE)));
>>      
> sector_num is int64_t, so the correct fix is to change '%ld' to '%" PRId64'.
>
>    

I noticed that, too. But offset is ssize_t.
Can you always be sure that (int64_t + ssize_t) results in a int64_t?
I don't think it's so easy.