Redirect edges leaving an exception handler to handler blocks through abnormal edges

[Washi1337]

Summary:
The handler region is often a region that is considered unreachable through normal execution paths. They therefore look very similar to orphan jumps in the resulting control flow graph, whereas in fact nodes within a protected region might transfer control to one of the handlers. Furthermore, for constructs like the try-finally, the actual "exception-less" flow might not be correctly encoded in the graph.

The suggestion is:

• To add an option to add abnormal edges from every node within the protected region to the handler blocks.
• To add an option to redirect edges that leave an exception handler to the handler block when necessary (for finally blocks), and add abnormal edges at the leaves of such a finally block to the original destination addresses.

A try-catch with orphan handler blocks

Try-catch after enabling option 1

Try-finally with orphan handler and inaccurate flow control

Try-finally after enabling option 2