From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1O904V-0001VK-M7 for qemu-devel@nongnu.org; Mon, 03 May 2010 14:08:47 -0400 Received: from [140.186.70.92] (port=33143 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O904Q-0000tu-7R for qemu-devel@nongnu.org; Mon, 03 May 2010 14:08:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1O8zxn-0008P9-Bc for qemu-devel@nongnu.org; Mon, 03 May 2010 14:01:53 -0400 Received: from mail-qy0-f188.google.com ([209.85.221.188]:39947) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1O8zxn-0008Gn-8q for qemu-devel@nongnu.org; Mon, 03 May 2010 14:01:51 -0400 Received: by qyk26 with SMTP id 26so4208956qyk.19 for ; Mon, 03 May 2010 11:00:50 -0700 (PDT) Message-ID: <4BDF0F4E.6050901@codemonkey.ws> Date: Mon, 03 May 2010 13:00:46 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 07/22] qemu-error: Introduce get_errno_string() References: <1271797792-24571-1-git-send-email-lcapitulino@redhat.com> <1271797792-24571-8-git-send-email-lcapitulino@redhat.com> <20100421082855.GB12843@redhat.com> In-Reply-To: <20100421082855.GB12843@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: kwolf@redhat.com, armbru@redhat.com, quintela@redhat.com, qemu-devel@nongnu.org, Luiz Capitulino On 04/21/2010 03:28 AM, Daniel P. Berrange wrote: > On Tue, Apr 20, 2010 at 06:09:37PM -0300, Luiz Capitulino wrote: > >> There are error handling functions in QEMU which print errno codes >> to the user. While it's debatable if this is good from a user >> perspective, sometimes it's the best you can do because it's what >> system calls return and this is also useful for debugging. >> >> So, we need a way to expose those codes in QMP. We can't use the >> codes themselfs because they may vary between systems. >> >> The best solution I can think of is returning the string >> representation of the name. For example, EIO becomes "EIO". >> >> This is what get_errno_string() does. >> >> Signed-off-by: Luiz Capitulino >> --- >> qemu-error.c | 25 +++++++++++++++++++++++++ >> qemu-error.h | 1 + >> 2 files changed, 26 insertions(+), 0 deletions(-) >> >> diff --git a/qemu-error.c b/qemu-error.c >> index 5a35e7c..55ce133 100644 >> --- a/qemu-error.c >> +++ b/qemu-error.c >> @@ -207,3 +207,28 @@ void error_report(const char *fmt, ...) >> va_end(ap); >> error_printf("\n"); >> } >> + >> +/* >> + * This is probably only useful for QMP >> + */ >> +const char *get_errno_string(int err) >> +{ >> + assert(err< 0); >> + >> + switch (err) { >> + case -EINVAL: >> + return "EINVAL"; >> + case -EIO: >> + return "EIO"; >> + case -ENOENT: >> + return "ENOENT"; >> + case -ENOMEDIUM: >> + return "ENOMEDIUM"; >> + case -ENOTSUP: >> + return "ENOTSUP"; >> + default: >> + return "unknown"; >> + } >> + >> + abort(); >> +} >> > Wouldn't it be nicer to return strerror_r() output instead of errno > names ? > Both are equally wrong :-) QMP should insult users from underlying platform quirks. We should translate errnos to appropriate QMP error types. Regards, Anthony Liguori > Daniel >