From 4f6e8bf8d184f3064d0d038f0439bf036f6a597b Mon Sep 17 00:00:00 2001
From: Garry Newman <garrynewman@users.noreply.github.com>
Date: Thu, 8 Aug 2019 11:00:34 +0100
Subject: [PATCH] Trying PreserveAttribute instead

---
 Facepunch.Steamworks/Utility/Helpers.cs        |  6 ++++++
 Facepunch.Steamworks/Utility/SteamInterface.cs | 11 -----------
 Facepunch.Steamworks/Utility/Utf8String.cs     |  1 +
 3 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/Facepunch.Steamworks/Utility/Helpers.cs b/Facepunch.Steamworks/Utility/Helpers.cs
index 26917a3..91dfe5e 100644
--- a/Facepunch.Steamworks/Utility/Helpers.cs
+++ b/Facepunch.Steamworks/Utility/Helpers.cs
@@ -73,4 +73,10 @@ internal class MonoPInvokeCallbackAttribute : Attribute
 	{
 		public MonoPInvokeCallbackAttribute() { }
 	}
+
+	/// <summary>
+	/// Prevent unity from stripping shit we depend on
+	/// https://docs.unity3d.com/Manual/ManagedCodeStripping.html
+	/// </summary>
+	internal class PreserveAttribute : System.Attribute { }
 }
diff --git a/Facepunch.Steamworks/Utility/SteamInterface.cs b/Facepunch.Steamworks/Utility/SteamInterface.cs
index 2ead970..d9d10ba 100644
--- a/Facepunch.Steamworks/Utility/SteamInterface.cs
+++ b/Facepunch.Steamworks/Utility/SteamInterface.cs
@@ -31,7 +31,6 @@ public void Init()
 				return;
 			}
 
-			PreservationHack();
 			throw new System.Exception( "Trying to initialize Steam Interface but Steam not initialized" );
 		}
 
@@ -110,15 +109,5 @@ internal virtual void Shutdown()
 		}
 
 		public abstract void InitInternals();
-
-		internal void PreservationHack()
-		{
-			//
-			// Stop Utf8StringToNative.GetInstance getting culled by stuff like Unity's
-			// asselmbly optimization stuff. Here we just call it so it can't not exist.
-			//
-			var i = Utf8StringToNative.GetInstance( "don't cull this function" );
-			i.GetNativeDataSize();
-		}
 	}
 }
\ No newline at end of file
diff --git a/Facepunch.Steamworks/Utility/Utf8String.cs b/Facepunch.Steamworks/Utility/Utf8String.cs
index 062847d..ac73835 100644
--- a/Facepunch.Steamworks/Utility/Utf8String.cs
+++ b/Facepunch.Steamworks/Utility/Utf8String.cs
@@ -38,6 +38,7 @@ public IntPtr MarshalManagedToNative(object managedObj)
 		public void CleanUpManagedData(object managedObj) => throw new System.NotImplementedException();
 		public int GetNativeDataSize() => -1;
 
+		[Preserve]
 		public static ICustomMarshaler GetInstance(string cookie) => new Utf8StringToNative();
 	}