private static unsafe IntPtr FindOriginalVTableOwner(IntPtr baseMostClass, IntPtr ownerClass, IntPtr functionAddress, int vtableIndex)
{
// Don't search lower than the target base
if (ownerClass == baseMostClass)
{
return(ownerClass);
}
IntPtr originalOwner = ownerClass;
while ((ownerClass = Native_UClass.GetSuperClass(ownerClass)) != IntPtr.Zero)
{
IntPtr obj = Native_UClass.GetDefaultObject(ownerClass, true);
IntPtr *vtable = *(IntPtr **)obj;
if (vtable[vtableIndex] == functionAddress)
{
originalOwner = ownerClass;
}
// Don't search lower than the target base
if (ownerClass == baseMostClass)
{
return(ownerClass);
}
}
return(originalOwner);
}
private void MoveToTransientPackage(IntPtr obj)
{
// Copy of UObjectBase.cpp UClassCompiledInDefer
// Check if rooted?
Native_UObjectBaseUtility.RemoveFromRoot(obj);
Native_UObjectBaseUtility.ClearFlags(obj, EObjectFlags.Standalone | EObjectFlags.Public);
IntPtr defaultObject = Native_UClass.GetDefaultObject(obj, false);
if (defaultObject != IntPtr.Zero)
{
// Check if rooted?
Native_UObjectBaseUtility.RemoveFromRoot(defaultObject);
Native_UObjectBaseUtility.ClearFlags(defaultObject, EObjectFlags.Standalone | EObjectFlags.Public);
}
FName oldClassRename = NativeReflection.MakeUniqueObjectName(NativeReflection.GetTransientPackage(),
Native_UObjectBase.GetClass(obj), new FName("USharpHotReload_" + Native_UObjectBase.GetFName(obj)));
using (FStringUnsafe oldClassRenameUnsafe = new FStringUnsafe(oldClassRename.ToString()))
{
Native_UObject.Rename(obj, ref oldClassRenameUnsafe.Array, NativeReflection.GetTransientPackage(), ERenameFlags.None);
}
Native_UObjectBaseUtility.SetFlags(obj, EObjectFlags.Transient);
Native_UObjectBaseUtility.AddToRoot(obj);
}
public static unsafe void Load()
{
vtableRedirects = new List <FunctionRedirect>();
AddVTableRedirects();
// We have three classes UDummyObject3 : UDummyObject2 : UDummyObject1 : UObject
//
// UDummyObject1 overrides function "X"
// UDummyObject2 doesn't function "X"
// UDummyObject3 overrides function "X"
//
// Scan the vtable for each dummy object, search for an entry where vtable entry 1==2 && 1!=3
// - We can assume this entry is our desired vtable index
// - This may break down in situations where there is multiple inheritance
// - If this fails to complete properly this will result in a crash (or worse)
foreach (FunctionRedirect redirect in vtableRedirects)
{
IntPtr dummyClass1 = NativeReflection.GetClass("/Script/USharp." + redirect.DummyName + "1");
IntPtr dummyClass2 = NativeReflection.GetClass("/Script/USharp." + redirect.DummyName + "2");
IntPtr dummyClass3 = NativeReflection.GetClass("/Script/USharp." + redirect.DummyName + "3");
IntPtr dummyObject1 = Native_UClass.GetDefaultObject(dummyClass1, true);
IntPtr dummyObject2 = Native_UClass.GetDefaultObject(dummyClass2, true);
IntPtr dummyObject3 = Native_UClass.GetDefaultObject(dummyClass3, true);
IntPtr *dummyVTable1 = *(IntPtr **)dummyObject1;
IntPtr *dummyVTable2 = *(IntPtr **)dummyObject2;
IntPtr *dummyVTable3 = *(IntPtr **)dummyObject3;
for (int i = 0; i < int.MaxValue; i++)
{
IntPtr dummyFunc1 = dummyVTable1[i];
IntPtr dummyFunc2 = dummyVTable2[i];
IntPtr dummyFunc3 = dummyVTable3[i];
if (dummyFunc1 == dummyFunc2 && dummyFunc1 != dummyFunc3)
{
redirect.NativeCallback = dummyFunc1;
redirect.VTableIndex = i;
break;
}
}
}
}
/// <summary>
/// Get the default object from the class
/// </summary>
/// <param name="createIfNeeded">if true (default) then the CDO is created if it is NULL.</param>
/// <returns>the CDO for this class</returns>
public UObject GetDefaultObject(bool createIfNeeded = true)
{
return(GCHelper.Find(Native_UClass.GetDefaultObject(Address, createIfNeeded)));
}
