The CLR Profiling API allows you to hook managed functions so that your profiler is called when a function is entered, returns, or exits via tailcall. We refer to these as Enter/Leave/Tailcall hooks, or “ELT” hooks. In this special multi-part investigative...

A frequent topic of discussion between those of us on the CLR Profiling API team at Microsoft and our customers is how to write a profiler that rewrites IL to do cool stuff. Unfortunately, there still is very little documentation on how to do this, and...