From patchwork Mon Jan 6 22:03:09 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luiz Capitulino X-Patchwork-Id: 307455 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 0F1A52C00C9 for ; Tue, 7 Jan 2014 09:07:17 +1100 (EST) Received: from localhost ([::1]:37809 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W0IKI-0002iu-S4 for incoming@patchwork.ozlabs.org; Mon, 06 Jan 2014 17:07:14 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51731) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W0IGi-0008OB-LJ for qemu-devel@nongnu.org; Mon, 06 Jan 2014 17:03:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W0IGd-0000z5-Et for qemu-devel@nongnu.org; Mon, 06 Jan 2014 17:03:32 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41290) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W0IGd-0000yp-77 for qemu-devel@nongnu.org; Mon, 06 Jan 2014 17:03:27 -0500 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s06M3Pip025842 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 6 Jan 2014 17:03:25 -0500 Received: from localhost (ovpn-113-124.phx2.redhat.com [10.3.113.124]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id s06M3OtU030660; Mon, 6 Jan 2014 17:03:25 -0500 From: Luiz Capitulino To: anthony@codemonkey.ws Date: Mon, 6 Jan 2014 17:03:09 -0500 Message-Id: <1389045795-18706-9-git-send-email-lcapitulino@redhat.com> In-Reply-To: <1389045795-18706-1-git-send-email-lcapitulino@redhat.com> References: <1389045795-18706-1-git-send-email-lcapitulino@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: qemu-devel@nongnu.org Subject: [Qemu-devel] [PULL 08/14] error: Add error_abort X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Peter Crosthwaite Add a special Error * that can be passed to error handling APIs to signal that any errors are fatal and should abort QEMU. There are two advantages to this: - allows for brevity when wishing to assert success of Error ** accepting APIs. No need for this pattern: Error * local_err = NULL; api_call(foo, bar, &local_err); assert_no_error(local_err); This also removes the need for _nofail variants of APIs with asserting call sites now reduced to 1LOC. - SIGABRT happens from within the offending API. When a fatal error occurs in an API call (when the caller is asserting sucess) failure often means the API itself is broken. With the abort happening in the API call now, the stack frames into the call are available at debug time. In the assert_no_error scheme the abort happens after the fact. The exact semantic is that when an error is raised, if the argument Error ** matches &error_abort, then the abort occurs immediately. The error messaged is reported. For error_propagate, if the destination error is &error_abort, then the abort happens at propagation time. Signed-off-by: Peter Crosthwaite Reviewed-by: Markus Armbruster Signed-off-by: Luiz Capitulino --- include/qapi/error.h | 6 ++++++ util/error.c | 22 +++++++++++++++++++++- 2 files changed, 27 insertions(+), 1 deletion(-) diff --git a/include/qapi/error.h b/include/qapi/error.h index 7d4c696..c0f0c3b 100644 --- a/include/qapi/error.h +++ b/include/qapi/error.h @@ -95,4 +95,10 @@ void error_propagate(Error **dst_err, Error *local_err); */ void error_free(Error *err); +/** + * If passed to error_set and friends, abort(). + */ + +extern Error *error_abort; + #endif diff --git a/util/error.c b/util/error.c index 3ee362a..f11f1d5 100644 --- a/util/error.c +++ b/util/error.c @@ -23,6 +23,8 @@ struct Error ErrorClass err_class; }; +Error *error_abort; + void error_set(Error **errp, ErrorClass err_class, const char *fmt, ...) { Error *err; @@ -41,6 +43,11 @@ void error_set(Error **errp, ErrorClass err_class, const char *fmt, ...) va_end(ap); err->err_class = err_class; + if (errp == &error_abort) { + error_report("%s", error_get_pretty(err)); + abort(); + } + *errp = err; errno = saved_errno; @@ -72,6 +79,11 @@ void error_set_errno(Error **errp, int os_errno, ErrorClass err_class, va_end(ap); err->err_class = err_class; + if (errp == &error_abort) { + error_report("%s", error_get_pretty(err)); + abort(); + } + *errp = err; errno = saved_errno; @@ -112,6 +124,11 @@ void error_set_win32(Error **errp, int win32_err, ErrorClass err_class, va_end(ap); err->err_class = err_class; + if (errp == &error_abort) { + error_report("%s", error_get_pretty(err)); + abort(); + } + *errp = err; } @@ -153,7 +170,10 @@ void error_free(Error *err) void error_propagate(Error **dst_err, Error *local_err) { - if (dst_err && !*dst_err) { + if (local_err && dst_err == &error_abort) { + error_report("%s", error_get_pretty(local_err)); + abort(); + } else if (dst_err && !*dst_err) { *dst_err = local_err; } else if (local_err) { error_free(local_err);