In general, reflection built into programming languages provides no access to the content of functions. So you pretty much can't do this with reflection.
You might be able to do it if you have access to the byte-code equivalent, but byte code can't really answer questions about the syntax of the method, e.g., "how many return statements exists returning the same expression".
If you want to reason about code, your need to reason about the source code. This means you need access to a parser, and often other useful facts ("what the declaration of X?", "Is the type of X and Y compatible?", "Does data flow from X to Y?"), etc.
Roslyn provides some of this information. There are also commercial solutions (I have one).