Register the local error codes with D-Bus to return a nice error message

src/Makefile.am

@@ -24,6 +24,8 @@ AM_CPPFLAGS =						\
 bin_PROGRAMS = fwupdmgr
 
 fwupdmgr_SOURCES =					\
+	fu-common.c					\
+	fu-common.h					\
 	fu-device.c					\
 	fu-device.h					\
 	fu-util.c
@@ -61,6 +63,7 @@ libexec_PROGRAMS =					\
 
 fwupd_SOURCES =						\
 	fu-cleanup.h					\
+	fu-common.c					\
 	fu-common.h					\
 	fu-debug.c					\
 	fu-debug.h					\

src/fu-common.c

@@ -0,0 +1,47 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
+ *
+ * Copyright (C) 2015 Richard Hughes <richard@hughsie.com>
+ *
+ * Licensed under the GNU General Public License Version 2
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+
+#include <glib-object.h>
+#include <gio/gio.h>
+
+#include "fu-common.h"
+
+/**
+ * fu_error_quark:
+ *
+ * Return value: An error quark.
+ *
+ * Since: 0.1.0
+ **/
+GQuark
+fu_error_quark (void)
+{
+	static GQuark quark = 0;
+	if (!quark) {
+		quark = g_quark_from_static_string ("FuError");
+		g_dbus_error_register_error (quark,
+					     FU_ERROR_INTERNAL,
+					     "org.freedesktop.fwupd.InternalError");
+	}
+	return quark;
+}

src/fu-common.h

@@ -26,12 +26,19 @@
 #define FWUPD_DBUS_SERVICE		"org.freedesktop.fwupd"
 #define FWUPD_DBUS_INTERFACE		"org.freedesktop.fwupd"
 
-#define FU_ERROR			1
+#define FU_ERROR			fu_error_quark()
-#define FU_ERROR_INTERNAL		0
 
 #define FU_DEVICE_KEY_VERSION		"Version"
 #define FU_DEVICE_KEY_PROVIDER		"Provider"
 #define FU_DEVICE_KEY_GUID		"Guid"
 #define FU_DEVICE_KEY_ONLY_OFFLINE	"OnlyOffline"
 
+typedef enum {
+	FU_ERROR_INTERNAL,
+	/* private */
+	FU_ERROR_LAST
+} FuError;
+
+GQuark		 fu_error_quark			(void);
+
 #endif /* __FU_COMMON_H */

src/fu-util.c

@@ -33,7 +33,6 @@
 #include "fu-common.h"
 #include "fu-provider.h"
 
-#define FU_ERROR			1
 #define FU_ERROR_INVALID_ARGUMENTS	0
 #define FU_ERROR_NO_SUCH_CMD		1