Add a lint check for trait placement on hardcoded actor names.

OpenRA.Game/Traits/DebugPauseState.cs

@@ -11,6 +11,7 @@
 
 namespace OpenRA.Traits
 {
+	[TraitLocation(SystemActors.World)]
 	[Desc("Checks for pause related desyncs. Attach this to the world actor.")]
 	public class DebugPauseStateInfo : TraitInfo
 	{

OpenRA.Game/Traits/LintAttributes.cs

@@ -105,4 +105,14 @@ namespace OpenRA.Traits
 			PlayerPaletteReferenceSwitch = playerPaletteReferenceSwitch;
 		}
 	}
+
+	[AttributeUsage(AttributeTargets.Class)]
+	public sealed class TraitLocationAttribute : Attribute
+	{
+		public readonly SystemActors SystemActors;
+		public TraitLocationAttribute(SystemActors systemActors)
+		{
+			SystemActors = systemActors;
+		}
+	}
 }

OpenRA.Game/Traits/Player/FrozenActorLayer.cs

@@ -22,6 +22,7 @@ namespace OpenRA.Traits
 		void OnVisibilityChanged(FrozenActor frozen);
 	}
 
+	[TraitLocation(SystemActors.Player)]
 	[Desc("Required for FrozenUnderFog to work. Attach this to the player actor.")]
 	public class FrozenActorLayerInfo : TraitInfo, Requires<ShroudInfo>
 	{

OpenRA.Game/Traits/Player/PlayerColorPalette.cs

@@ -14,7 +14,8 @@ using OpenRA.Primitives;
 
 namespace OpenRA.Traits
 {
-	[Desc("Add this to the Player actor definition.")]
+	[TraitLocation(SystemActors.World | SystemActors.EditorWorld)]
+	[Desc("Add this to the World actor definition.")]
 	public class PlayerColorPaletteInfo : TraitInfo
 	{
 		[PaletteReference]

OpenRA.Game/Traits/Player/Shroud.cs

@@ -14,6 +14,7 @@ using System.Collections.Generic;
 
 namespace OpenRA.Traits
 {
+	[TraitLocation(SystemActors.Player | SystemActors.EditorPlayer)]
 	[Desc("Required for shroud and fog visibility checks. Add this to the player actor.")]
 	public class ShroudInfo : TraitInfo, ILobbyOptions
 	{

OpenRA.Game/Traits/World/DebugVisualizations.cs

@@ -11,6 +11,7 @@
 
 namespace OpenRA.Traits
 {
+	[TraitLocation(SystemActors.World | SystemActors.EditorWorld)]
 	[Desc("Enables visualization commands. Attach this to the world actor.")]
 	public class DebugVisualizationsInfo : TraitInfo<DebugVisualizations> { }
 

OpenRA.Game/Traits/World/Faction.cs

@@ -14,6 +14,7 @@ using System.Collections.Generic;
 namespace OpenRA.Traits
 {
 	[Desc("Attach this to the `World` actor.")]
+	[TraitLocation(SystemActors.World | SystemActors.EditorWorld)]
 	public class FactionInfo : TraitInfo<Faction>
 	{
 		[Desc("This is the name exposed to the players.")]

OpenRA.Game/Traits/World/ScreenMap.cs

@@ -30,6 +30,7 @@ namespace OpenRA.Traits
 		public override string ToString() { return "{0}->{1}".F(Actor.Info.Name, Bounds.GetType().Name); }
 	}
 
+	[TraitLocation(SystemActors.World | SystemActors.EditorWorld)]
 	public class ScreenMapInfo : TraitInfo
 	{
 		[Desc("Size of partition bins (world pixels)")]

OpenRA.Game/Traits/World/ScreenShaker.cs

@@ -16,6 +16,7 @@ using OpenRA.Graphics;
 
 namespace OpenRA.Traits
 {
+	[TraitLocation(SystemActors.World)]
 	public class ScreenShakerInfo : TraitInfo
 	{
 		public readonly float2 MinMultiplier = new float2(-3, -3);