Allow static method injection

Author: limoka

Il2CppInterop.Runtime/Injection/ClassInjector.cs

@@ -526,7 +526,6 @@ private static bool IsFieldEligible(FieldInfo field)
     private static bool IsMethodEligible(MethodInfo method)
     {
         if (method.Name == "Finalize") return false;
-        if (method.IsStatic) return false;
         if (method.CustomAttributes.Any(it => typeof(HideFromIl2CppAttribute).IsAssignableFrom(it.AttributeType)))
             return false;
 
@@ -559,10 +558,12 @@ private static bool IsMethodEligible(MethodInfo method)
         foreach (var parameter in method.GetParameters())
         {
             var parameterType = parameter.ParameterType;
-            if (!IsTypeSupported(parameterType))
+            if (!IsTypeSupported(parameterType) ||
+                method.IsStatic && parameterType.IsGenericType && parameterType.ContainsGenericParameters)
             {
                 Logger.Instance.LogWarning(
-                    "Method {Method} on type {DeclaringType} has unsupported parameter {Parameter} of type {ParameterType}", method.ToString(), method.DeclaringType, parameter, parameterType);
+                    "Method {Method} on type {DeclaringType} has unsupported parameter {Parameter} of type {ParameterType}", method.ToString(),
+                    method.DeclaringType, parameter, parameterType);
                 return false;
             }
         }
@@ -702,6 +703,11 @@ private static bool IsMethodEligible(MethodInfo method)
         converted.Flags = Il2CppMethodFlags.METHOD_ATTRIBUTE_PUBLIC |
                           Il2CppMethodFlags.METHOD_ATTRIBUTE_HIDE_BY_SIG;
 
+        if (monoMethod.IsStatic)
+        {
+            converted.Flags |= Il2CppMethodFlags.METHOD_ATTRIBUTE_STATIC;
+        }
+
         if (monoMethod.IsAbstract)
         {
             converted.Flags |= Il2CppMethodFlags.METHOD_ATTRIBUTE_ABSTRACT;
@@ -810,7 +816,8 @@ private static Delegate CreateInvoker(MethodInfo monoMethod)
 
         var body = method.GetILGenerator();
 
-        body.Emit(OpCodes.Ldarg_2);
+        if (!monoMethod.IsStatic)
+            body.Emit(OpCodes.Ldarg_2);
         for (var i = 0; i < monoMethod.GetParameters().Length; i++)
         {
             var parameterInfo = monoMethod.GetParameters()[i];
@@ -892,33 +899,41 @@ private static void StaticVoidIntPtrInvoker_MetadataV29(IntPtr methodPointer, Il
 
     private static Delegate CreateTrampoline(MethodInfo monoMethod)
     {
-        var nativeParameterTypes = new[] { typeof(IntPtr) }.Concat(monoMethod.GetParameters()
-            .Select(it => it.ParameterType.NativeType()).Concat(new[] { typeof(Il2CppMethodInfo*) })).ToArray();
+        var nativeParameterTypes = new List<Type>();
+        if (!monoMethod.IsStatic)
+            nativeParameterTypes.Add(typeof(IntPtr));
+        nativeParameterTypes.AddRange(monoMethod.GetParameters().Select(it => it.ParameterType.NativeType()));
+        nativeParameterTypes.Add(typeof(Il2CppMethodInfo*));
 
-        var managedParameters = new[] { monoMethod.DeclaringType }
-            .Concat(monoMethod.GetParameters().Select(it => it.ParameterType)).ToArray();
+        var managedParameters = new List<Type>();
+        if (!monoMethod.IsStatic)
+            managedParameters.Add(monoMethod.DeclaringType);
+        managedParameters.AddRange(monoMethod.GetParameters().Select(it => it.ParameterType));
 
         var method = new DynamicMethod(
             "Trampoline_" + ExtractSignature(monoMethod) + monoMethod.DeclaringType + monoMethod.Name,
             MethodAttributes.Static | MethodAttributes.Public, CallingConventions.Standard,
-            monoMethod.ReturnType.NativeType(), nativeParameterTypes,
+            monoMethod.ReturnType.NativeType(), nativeParameterTypes.ToArray(),
             monoMethod.DeclaringType, true);
 
-        var signature = new DelegateSupport.MethodSignature(monoMethod, true);
+        var signature = new DelegateSupport.MethodSignature(monoMethod, !monoMethod.IsStatic);
         var delegateType = DelegateSupport.GetOrCreateDelegateType(signature, monoMethod);
 
         var body = method.GetILGenerator();
 
         body.BeginExceptionBlock();
 
-        body.Emit(OpCodes.Ldarg_0);
-        body.Emit(OpCodes.Call,
-            typeof(ClassInjectorBase).GetMethod(nameof(ClassInjectorBase.GetMonoObjectFromIl2CppPointer))!);
-        body.Emit(OpCodes.Castclass, monoMethod.DeclaringType);
+        if (!monoMethod.IsStatic)
+        {
+            body.Emit(OpCodes.Ldarg_0);
+            body.Emit(OpCodes.Call,
+                typeof(ClassInjectorBase).GetMethod(nameof(ClassInjectorBase.GetMonoObjectFromIl2CppPointer))!);
+            body.Emit(OpCodes.Castclass, monoMethod.DeclaringType);
+        }
 
-        var indirectVariables = new LocalBuilder[managedParameters.Length];
+        var indirectVariables = new LocalBuilder[managedParameters.Count];
 
-        for (var i = 1; i < managedParameters.Length; i++)
+        for (var i = 1; i < managedParameters.Count; i++)
         {
             var parameter = managedParameters[i];
             if (parameter.IsSubclassOf(typeof(ValueType)))
@@ -988,7 +1003,7 @@ void HandleTypeConversion(Type type)
             body.Emit(OpCodes.Stloc, managedReturnVariable);
         }
 
-        for (var i = 1; i < managedParameters.Length; i++)
+        for (var i = 1; i < managedParameters.Count; i++)
         {
             var variable = indirectVariables[i];
             if (variable == null)