which-func-cleanup-function

which-func-cleanup-function is a variable defined in `which-func.el'.
Its value is

nil

• This variable may be risky if used as a file-local variable.

Documentation:
Function to transform a string before displaying it in the mode line.
The function is called with one argument, the string to display.
Its return value is displayed in the mode line.
If nil, no function is called. The default value is nil.

This feature can be useful if Imenu is set up to make more
detailed entries (e.g., containing the argument list of a function),
and you want to simplify them for the mode line
(e.g., removing the parameter list to just have the function name.)