[Q] figuring out a system / source file

Hello, starting from a file currently being processed (as per either *compile-file-truename* or *load-truename*), how can I retrieve the ASDF system currently being processed, and ultimately, the corresponding source file component (when *load-truename* returns a fasl) ? Thanks. -- My new Jazz CD entitled "Roots and Leaves" is out! Check it out: http://didierverna.com/records/roots-and-leaves.php Lisp, Jazz, Aïkido: http://www.didierverna.info