Fix CA1018

.editorconfig

@@ -616,6 +616,9 @@ dotnet_code_quality.api_surface = all
 #dotnet_code_quality.CA1010.additional_required_generic_interfaces =
 dotnet_diagnostic.CA1010.severity = warning
 
+# Mark attributes with 'AttributeUsageAttribute'.
+dotnet_diagnostic.CA1018.severity = warning
+
 # Provide ObsoleteAttribute message.
 dotnet_diagnostic.CA1041.severity = warning
 

OpenRA.Game/Scripting/ScriptContext.cs

@@ -33,6 +33,7 @@ namespace OpenRA.Scripting
 	}
 
 	// For traitinfos that provide actor / player commands
+	[AttributeUsage(AttributeTargets.Class)]
 	public sealed class ScriptPropertyGroupAttribute : Attribute
 	{
 		public readonly string Category;
@@ -40,8 +41,10 @@ namespace OpenRA.Scripting
 	}
 
 	// For property groups that are safe to initialize invoke on destroyed actors
+	[AttributeUsage(AttributeTargets.Class)]
 	public sealed class ExposedForDestroyedActors : Attribute { }
 
+	[AttributeUsage(AttributeTargets.Property | AttributeTargets.Method)]
 	public sealed class ScriptActorPropertyActivityAttribute : Attribute { }
 
 	public abstract class ScriptActorProperties
@@ -115,6 +118,7 @@ namespace OpenRA.Scripting
 		}
 	}
 
+	[AttributeUsage(AttributeTargets.Class)]
 	public sealed class ScriptGlobalAttribute : Attribute
 	{
 		public readonly string Name;

OpenRA.Game/Traits/TraitsInterfaces.cs

@@ -23,6 +23,7 @@ using OpenRA.Support;
 
 namespace OpenRA.Traits
 {
+	[AttributeUsage(AttributeTargets.Interface)]
 	public sealed class RequireExplicitImplementationAttribute : Attribute { }
 
 	[Flags]