Returns the callers of a function.
who-calls dspec => callers
who-calls returns a list of dspecs naming the definitions which call the function named by dspec.
See also the editor commands
List Callers and
Show Paths To.
The cross-referencing information used by
who-calls is generated when code is compiled with source-level debugging switched on.
LispWorks User Guide and Reference Manual - 20 Sep 2017