clang plugin registry

Hi all,
I am trying to write the call graph plugin for clang. initially i just write code according to callgraph.cpp and callgraph.h files in clang. but i cant registry my callgraph plugin in clang registry. Is it suitable to just copy my callgraph code into the PrintFunctionNames.cpp file in clang /examples . is pluginASTAction will execute it.

thnks.