The function calling function cross reference creates a file in the
     output directory which contians a complete cross reference for
     every function call in your source code. If Click! cannot resolve
     the function reference in your source code, it goes to your library
     files and finds the functions in your libraries!

     You can control the name of the file with the following CLICK.INI
     directive.

     SOURCE_XREF_FILE=SRC_CROS.TXT