m4-program

m4-program is a variable defined in `m4-mode.el'.
Its value is

"m4"

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

Documentation:
File name of the m4 executable.
If m4 is not in your PATH, set this to an absolute file name.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.4 of Emacs.