Getting message list being processed in ProcessMessage()

I am debugging a crash that occurs in the ProcessMessage() method. I have checked other parts from my code to try to find where could a message be sent that would cause this without success. So the option I'm left with is to try to see what are the messages that ProcessMessage() is processing.

Does anyone know if there is a way to get the message list that ProcessMessage() will iterate? Or, if it is not possible, how to capture every message sent using the SendMessage() function?