Pass in delegate instead of function pointer

BepInEx.IL2CPP/Hook/BaseNativeDetour.cs

@@ -10,14 +10,16 @@ internal abstract class BaseNativeDetour<T> : INativeDetour where T : BaseNative
 {
     protected static readonly ManualLogSource Logger = BepInEx.Logging.Logger.CreateLogSource(typeof(T).Name);
 
-    protected BaseNativeDetour(nint originalMethodPtr, nint detourMethodPtr)
+    protected BaseNativeDetour(nint originalMethodPtr, Delegate detourMethod)
     {
         OriginalMethodPtr = originalMethodPtr;
-        DetourMethodPtr = detourMethodPtr;
+        DetourMethod = detourMethod;
+        DetourMethodPtr = Marshal.GetFunctionPointerForDelegate(detourMethod);
     }
 
     public bool IsPrepared { get; protected set; }
     protected MethodInfo TrampolineMethod { get; set; }
+    protected Delegate DetourMethod { get; set; }
 
     public nint OriginalMethodPtr { get; }
     public nint DetourMethodPtr { get; }

BepInEx.IL2CPP/Hook/Dobby/DobbyDetour.cs

@@ -1,8 +1,10 @@
+using System;
+
 namespace BepInEx.IL2CPP.Hook.Dobby;
 
 internal class DobbyDetour : BaseNativeDetour<DobbyDetour>
 {
-    public DobbyDetour(nint originalMethodPtr, nint detourMethodPtr) : base(originalMethodPtr, detourMethodPtr) { }
+    public DobbyDetour(nint originalMethodPtr, Delegate detourMethod) : base(originalMethodPtr, detourMethod) { }
 
     protected override void ApplyImpl() => DobbyLib.Commit(OriginalMethodPtr);
 

BepInEx.IL2CPP/Hook/Funchook/FunchookDetour.cs

@@ -7,7 +7,7 @@ internal class FunchookDetour : BaseNativeDetour<FunchookDetour>
 {
     private readonly nint funchookInstance;
 
-    public FunchookDetour(nint originalMethodPtr, nint detourMethodPtr) : base(originalMethodPtr, detourMethodPtr)
+    public FunchookDetour(nint originalMethodPtr, Delegate detourMethod) : base(originalMethodPtr, detourMethod)
     {
         funchookInstance = FunchookLib.Create();
     }

BepInEx.IL2CPP/Hook/INativeDetour.cs

@@ -22,11 +22,11 @@ public interface INativeDetour : IDetour
     public nint DetourMethodPtr { get; }
     public nint TrampolinePtr { get; }
 
-    private static INativeDetour CreateDefault(nint original, nint target) =>
+    private static INativeDetour CreateDefault<T>(nint original, T target) where T : Delegate =>
         // TODO: check and provide an OS accurate provider
         new DobbyDetour(original, target);
 
-    public static INativeDetour Create(nint original, nint target)
+    public static INativeDetour Create<T>(nint original, T target) where T : Delegate
     {
         var detour = DetourProviderType.Value switch
         {
@@ -36,7 +36,7 @@ public interface INativeDetour : IDetour
         };
         if (!ReflectionHelper.IsMono)
         {
-            return new CacheDetourWrapper(detour);
+            return new CacheDetourWrapper(detour, target);
         }
         return detour;
     }
@@ -44,8 +44,7 @@ public interface INativeDetour : IDetour
     public static INativeDetour CreateAndApply<T>(nint from, T to, out T original)
         where T : Delegate
     {
-        var toPtr = Marshal.GetFunctionPointerForDelegate(to);
-        var detour = Create(from, toPtr);
+        var detour = Create(from, to);
         original = detour.GenerateTrampoline<T>();
         detour.Apply();
 
@@ -59,9 +58,10 @@ public interface INativeDetour : IDetour
 
         private List<object> _cache = new();
 
-        public CacheDetourWrapper(INativeDetour wrapped)
+        public CacheDetourWrapper(INativeDetour wrapped, Delegate target)
         {
             _wrapped = wrapped;
+            _cache.Add(target);
         }
 
         public void Dispose()

BepInEx.IL2CPP/Hook/Il2CppInteropDetourProvider.cs

@@ -1,10 +1,11 @@
 using Il2CppInterop.Runtime.Injection;
+using System;
 
 namespace BepInEx.IL2CPP.Hook;
 
 internal class Il2CppInteropDetourProvider : IDetourProvider
 {
-    public IDetour Create(nint original, nint target) =>
+    public IDetour Create<TDelegate>(nint original, TDelegate target) where TDelegate : Delegate =>
         new Il2CppInteropDetour(INativeDetour.Create(original, target));
 }