Support logging direct to journald, if enabled.

Instead of merely intercepting logging output from stdout/stderr from the
journal side of started processes, this has the advantage of meaning that the
origin process name will be correct.

fprintf won't work, because if a process starts children (like e.g. a
homescreen does), then their stdout/stderr are merged into their parent, and
journal has no way of differentiating the origin.

We are also able to store information about the context of logging, which might
be useful in post-mortem cases.

[ChangeLog][Platform Specific Changes][Linux] Systems with systemd may now pass
-journald to configure to send logging output to journald. Logging will still be
sent to stderr for interactive applications (run from a tty) or with
QT_NO_JOURNALD_LOG set to a non-empty value.

Change-Id: Ib260cec1ea87390bf44f267d217d795583407d00
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 54 insertions, 0 deletions

diff --git a/config.tests/unix/journald/journald.c b/config.tests/unix/journald/journald.c
new file mode 100644
index 0000000000..470d526e68
--- /dev/null
+++ b/config.tests/unix/journald/journald.c
@@ -0,0 +1,48 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Jolla Ltd, author: <robin.burchell@jollamobile.com>
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the config.tests of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <systemd/sd-journal.h>
+
+int main(int argc, char **argv)
+{
+    sd_journal_print_with_location(LOG_INFO, "CODE_FILE=foo.c", "CODE_LINE=0", "unknown_function", "test message");
+    return 0;
+}
diff --git a/config.tests/unix/journald/journald.pro b/config.tests/unix/journald/journald.pro
new file mode 100644
index 0000000000..2bb50ceb71
--- /dev/null
+++ b/config.tests/unix/journald/journald.pro
@@ -0,0 +1,6 @@
+SOURCES = journald.c
+
+CONFIG += link_pkgconfig
+PKGCONFIG_PRIVATE += libsystemd-journal
+
+CONFIG -= qt