From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58964) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZIY7w-0002Kz-1b for qemu-devel@nongnu.org; Fri, 24 Jul 2015 04:14:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZIY7r-0004rc-1W for qemu-devel@nongnu.org; Fri, 24 Jul 2015 04:14:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35450) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZIY7q-0004rS-PR for qemu-devel@nongnu.org; Fri, 24 Jul 2015 04:14:38 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id 80DC796FE for ; Fri, 24 Jul 2015 08:14:38 +0000 (UTC) References: <1437660098-4584-1-git-send-email-armbru@redhat.com> <1437660098-4584-8-git-send-email-armbru@redhat.com> <55B0FE7A.8070100@redhat.com> From: Laszlo Ersek Message-ID: <55B1F3EB.8050805@redhat.com> Date: Fri, 24 Jul 2015 10:14:35 +0200 MIME-Version: 1.0 In-Reply-To: <55B0FE7A.8070100@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 7/7] error: On abort, report where the error was created List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake , Markus Armbruster , qemu-devel@nongnu.org Cc: pbonzini@redhat.com, dgilbert@redhat.com, mst@redhat.com On 07/23/15 16:47, Eric Blake wrote: > On 07/23/2015 08:01 AM, Markus Armbruster wrote: >> This is particularly useful when we abort in error_propagate(), >> because there the stack backtrace doesn't lead to where the error was >> created. Looks like this: >> >> Unexpected error in parse_block_error_action() at /work/armbru/qemu/blockdev.c:322: >> qemu-system-x86_64: -drive if=none,werror=foo: 'foo' invalid write error action >> Aborted (core dumped) >> >> Note: to get this example output, I monkey-patched drive_new() to pass >> &error_abort to blockdev_init(). >> >> To keep the error handling boiler plate from growing even more, all >> error_setFOO() become macros expanding into error_setFOO_internal() >> with additional __FILE__, __LINE__, __func__ arguments. Not exactly >> pretty, but it works. >> >> The macro trickery breaks down when you take the address of an >> error_setFOO(). Fortunately, we do that in just one place: qemu-ga's >> Windows VSS provider and requester DLL wants to call >> error_setg_win32() through a function pointer "to avoid linking glib >> to the DLL". Use error_setg_win32_internal() there. The use of the >> function pointer is already wrapped in a macro, so the churn isn't >> bad. >> >> Code size increases by some 35KiB for me (0.7%). Tolerable. Could be >> less if we passed relative rather than absolute source file names to >> the compiler, or forwent reporting __func__. >> >> Signed-off-by: Markus Armbruster >> --- >> include/qapi/error.h | 43 +++++++++++++++++++++++++++-------- >> qga/vss-win32.c | 2 +- >> qga/vss-win32/requester.cpp | 5 +++-- >> qga/vss-win32/requester.h | 6 +++-- >> util/error.c | 55 ++++++++++++++++++++++++++++++++------------- >> 5 files changed, 81 insertions(+), 30 deletions(-) >> > >> +++ b/qga/vss-win32/requester.cpp >> @@ -23,8 +23,9 @@ >> /* Call QueryStatus every 10 ms while waiting for frozen event */ >> #define VSS_TIMEOUT_EVENT_MSEC 10 >> >> -#define err_set(e, err, fmt, ...) \ >> - ((e)->error_setg_win32((e)->errp, err, fmt, ## __VA_ARGS__)) >> +#define err_set(e, err, fmt, ...) \ >> + ((e)->error_setg_win32((e)->errp, __FILE__, __LINE__, __func__, \ >> + err, fmt, ## __VA_ARGS__)) > > Indentation looks odd here, but not fatal. > >> -void error_setg_errno(Error **errp, int os_errno, const char *fmt, ...) >> +void error_setg_errno_internal(Error **errp, >> + const char *src, int line, const char *func, >> + int os_errno, const char *fmt, ...) > > Indentation off again. > > Those are minor, and could be fixed by maintainer. > Reviewed-by: Eric Blake > I'm going to freeload in the wake of Eric's review, and just say "thank you" for including __func__. Acked-by: Laszlo Ersek