Add lint rule.

OpenRA.Mods.Common/Lint/CheckDefaultVisibility.cs

@@ -0,0 +1,36 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2015 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. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using System;
+using System.Linq;
+using OpenRA.GameRules;
+using OpenRA.Traits;
+
+namespace OpenRA.Mods.Common.Lint
+{
+	class CheckDefaultVisibility : ILintPass
+	{
+		public void Run(Action<string> emitError, Action<string> emitWarning, Map map)
+		{
+			foreach (var actorInfo in map.Rules.Actors)
+			{
+				if (actorInfo.Key.StartsWith("^"))
+					continue;
+
+				var count = actorInfo.Value.Traits.WithInterface<IDefaultVisibilityInfo>().Count();
+
+				if (count == 0)
+					emitError("Actor type `{0}` does not define a default visibility type!".F(actorInfo.Key));
+				else if (count > 1)
+					emitError("Actor type `{0}` defines multiple default visibility types!".F(actorInfo.Key));
+			}
+		}
+	}
+}

OpenRA.Mods.Common/OpenRA.Mods.Common.csproj

@@ -677,6 +677,7 @@
     <Compile Include="Traits\World\PaletteFromPaletteWithAlpha.cs" />
     <Compile Include="Traits\World\PaletteFromPlayerPaletteWithAlpha.cs" />
     <Compile Include="Traits\Modifiers\HiddenUnderShroud.cs" />
+    <Compile Include="Lint\CheckDefaultVisibility.cs" />
     <Compile Include="Traits\Modifiers\AlwaysVisible.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />