c-end-of-defun is an interactive compiled Lisp function in `cc-cmds.el'.

(c-end-of-defun &optional ARG)

Move forward to the end of a top level declaration.
With argument, do it that many times. Negative argument -N means move
back to Nth preceding end. Returns t unless search stops due to
beginning or end of buffer.

An end of a defun occurs right after the close-parenthesis that matches
the open-parenthesis that starts a defun; see `beginning-of-defun'.