/// <summary>
/// Write a DynamicMethod call by creating and injecting a custom delegate in the proxyType
/// </summary>
/// <param name="il">LazyILGenerator instance</param>
/// <param name="dynamicMethod">Dynamic method to get called</param>
/// <param name="proxyType">ProxyType builder</param>
internal static void WriteDynamicMethodCall(this LazyILGenerator il, DynamicMethod dynamicMethod, TypeBuilder proxyType)
{
// We create a custom delegate inside the module builder
CreateDelegateTypeFor(proxyType, dynamicMethod, out var delegateType, out var invokeMethod);
int index;
lock (_dynamicMethods)
{
_dynamicMethods.Add(dynamicMethod);
index = _dynamicMethods.Count - 1;
}
// We fill the DelegateCache<> for that custom type with the delegate instance
var fillDelegateMethodInfo = typeof(Elastic.Apm.Profiler.Managed.DuckTyping.DuckType.DelegateCache <>).MakeGenericType(delegateType).GetMethod("FillDelegate", BindingFlags.NonPublic | BindingFlags.Static);
fillDelegateMethodInfo.Invoke(null, new object[] { index });
// We get the delegate instance and load it in to the stack before the parameters (at the begining of the IL body)
il.SetOffset(0);
il.EmitCall(OpCodes.Call, typeof(DuckType.DelegateCache <>).MakeGenericType(delegateType).GetMethod("GetDelegate"), null);
il.ResetOffset();
// We emit the call to the delegate invoke method.
il.EmitCall(OpCodes.Callvirt, invokeMethod, null);
}
