public OverrideWrapper(MethodInfo original, MethodInfo modified, OverrideAttribute attribute, object instance = null)
{
// Set the variables
Original = original;
Modified = modified;
Instance = instance;
Attribute = attribute;
Local = Modified.DeclaringType.Assembly == Assembly.GetExecutingAssembly();
RuntimeHelpers.PrepareMethod(original.MethodHandle);
RuntimeHelpers.PrepareMethod(modified.MethodHandle);
PtrOriginal = Original.MethodHandle.GetFunctionPointer();
PtrModified = Modified.MethodHandle.GetFunctionPointer();
OffsetBackup = new OverrideUtilities.OffsetBackup(PtrOriginal);
Detoured = false;
}
/// <summary>
/// Loads override information for method
/// </summary>
/// <param name="method">Method to override another</param>
public static void LoadOverride(MethodInfo method)
{
// Get attribute related variables
OverrideAttribute attribute =
(OverrideAttribute)Attribute.GetCustomAttribute(method, typeof(OverrideAttribute));
// Check if method has been overrided before
if (Overrides.Count(a => a.Key.Method == attribute.Method) > 0)
{
return;
}
// Create wrapper for override
OverrideWrapper wrapper = new OverrideWrapper(attribute.Method, method, attribute);
// Override
wrapper.Override();
// Add override to the list
Overrides.Add(attribute, wrapper);
}
/// <summary>
/// Calls the original method that was Overrideed
/// </summary>
/// <param name="instance">The instance for the method(null if static)</param>
/// <param name="args">The arguments for the method</param>
/// <returns>The value tahat the original function returns</returns>
public static object CallOriginal(object instance = null, params object[] args)
{
StackTrace trace = new StackTrace(false);
if (trace.FrameCount < 1)
{
throw new Exception("Invalid trace back to the original method! Please provide the methodinfo instead!");
}
MethodBase modded = trace.GetFrame(1).GetMethod();
MethodInfo original = null;
if (!Attribute.IsDefined(modded, typeof(OverrideAttribute)))
{
modded = trace.GetFrame(2).GetMethod();
}
OverrideAttribute att = (OverrideAttribute)Attribute.GetCustomAttribute(modded, typeof(OverrideAttribute));
if (att == null)
{
throw new Exception("This method can only be called from an overwritten method!");
}
if (!att.MethodFound)
{
throw new Exception("The original method was never found!");
}
original = att.Method;
if (OverrideManager.Overrides.All(o => o.Value.Original != original))
{
throw new Exception("The Override specified was not found!");
}
OverrideWrapper wrapper = OverrideManager.Overrides.First(a => a.Value.Original == original).Value;
return(wrapper.CallOriginal(args, instance));
}