Fix FindGetTypeInfoFromTypeDefinitionIndex for Unity games built with IL2CPP Master (#60)

Author: nitrog0d

Il2CppInterop.Runtime/Injection/InjectorHelpers.cs

@@ -276,16 +276,32 @@ private static d_GetTypeInfoFromTypeDefinitionIndex FindGetTypeInfoFromTypeDefin
                 if (imageGetTypeXrefs.Count() > 1 && UnityVersionHandler.IsMetadataV29OrHigher)
                 {
                     // (Kasuromi): metadata v29 introduces handles and adds extra calls, a check for unity versions might be necessary in the future
-
-                    // Second call after obtaining handle, if there are any more calls in the future - correctly index into it if issues occur
-                    var getTypeInfoFromHandle = XrefScannerLowLevel.JumpTargets(imageGetType).Last();
-                    // Two calls, second one (GetIndexForTypeDefinitionInternal) is inlined
-                    getTypeInfoFromTypeDefinitionIndex = XrefScannerLowLevel.JumpTargets(getTypeInfoFromHandle).Single();
-
-                    // Xref scanner is sometimes confused about getTypeInfoFromHandle so we walk all the thunks until we hit the big method we need
-                    while (XrefScannerLowLevel.JumpTargets(getTypeInfoFromTypeDefinitionIndex).Count() == 1)
+                    
+                    Logger.Instance.LogTrace($"imageGetTypeXrefs.Length: {imageGetTypeXrefs.Length}");
+                    
+                    // If the game is built as IL2CPP Master, GetAssemblyTypeHandle is inlined, xrefs length is 3 and it's the first function call,
+                    // if not, it's the last call.
+                    var getTypeInfoFromHandle = imageGetTypeXrefs.Length == 2 ? imageGetTypeXrefs.Last() : imageGetTypeXrefs.First();
+                    
+                    Logger.Instance.LogTrace($"getTypeInfoFromHandle: {getTypeInfoFromHandle:X2}");
+
+                    var getTypeInfoFromHandleXrefs = XrefScannerLowLevel.JumpTargets(getTypeInfoFromHandle).ToArray();
+                    
+                    // If getTypeInfoFromHandle xrefs is not a single call, it's the function we want, if not, we keep xrefing until we find it
+                    if (getTypeInfoFromHandleXrefs.Length != 1)
+                    {
+                        getTypeInfoFromTypeDefinitionIndex = getTypeInfoFromHandle;
+                        Logger.Instance.LogTrace($"Xrefs length was not 1, getTypeInfoFromTypeDefinitionIndex: {getTypeInfoFromTypeDefinitionIndex:X2}");
+                    }
+                    else
                     {
-                        getTypeInfoFromTypeDefinitionIndex = XrefScannerLowLevel.JumpTargets(getTypeInfoFromTypeDefinitionIndex).Single();
+                        // Two calls, second one (GetIndexForTypeDefinitionInternal) is inlined
+                        getTypeInfoFromTypeDefinitionIndex = getTypeInfoFromHandleXrefs.Single();
+                        // Xref scanner is sometimes confused about getTypeInfoFromHandle so we walk all the thunks until we hit the big method we need
+                        while (XrefScannerLowLevel.JumpTargets(getTypeInfoFromTypeDefinitionIndex).ToArray().Length == 1)
+                        {
+                            getTypeInfoFromTypeDefinitionIndex = XrefScannerLowLevel.JumpTargets(getTypeInfoFromTypeDefinitionIndex).Single();
+                        }
                     }
                 }
             }