Add a lint test for audio notifications.

Only traits are linted - the UI still hardcodes
too many audio references for this to be worthwhile.

OpenRA.Mods.Common/Lint/CheckNotifications.cs

@@ -0,0 +1,57 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2018 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+using System.Linq;
+using OpenRA.GameRules;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Lint
+{
+	class CheckNotifications : ILintRulesPass
+	{
+		public void Run(Action<string> emitError, Action<string> emitWarning, Ruleset rules)
+		{
+			foreach (var actorInfo in rules.Actors)
+			{
+				foreach (var traitInfo in actorInfo.Value.TraitInfos<ITraitInfo>())
+				{
+					var fields = traitInfo.GetType().GetFields();
+					foreach (var field in fields.Where(x => x.HasAttribute<NotificationReferenceAttribute>()))
+					{
+						string type = null;
+						var notificationReference = field.GetCustomAttributes<NotificationReferenceAttribute>(true).First();
+						if (!string.IsNullOrEmpty(notificationReference.NotificationTypeFieldName))
+						{
+							var fieldInfo = fields.First(f => f.Name == notificationReference.NotificationTypeFieldName);
+							type = (string)fieldInfo.GetValue(traitInfo);
+						}
+						else
+							type = notificationReference.NotificationType;
+
+						var notifications = LintExts.GetFieldValues(traitInfo, field, emitError);
+						foreach (var notification in notifications)
+						{
+							if (string.IsNullOrEmpty(notification))
+								continue;
+
+							SoundInfo soundInfo;
+							if (string.IsNullOrEmpty(type) || !rules.Notifications.TryGetValue(type.ToLowerInvariant(), out soundInfo) ||
+									!soundInfo.Notifications.ContainsKey(notification))
+								emitError("Undefined notification reference {0}.{1} detected at {2} for {3}".F(
+									type ?? "(null)", notification, traitInfo.GetType().Name, actorInfo.Key));
+						}
+					}
+				}
+			}
+		}
+	}
+}