c-electric-star is an interactive compiled Lisp function in `cc-cmds.el'.

(c-electric-star ARG)

Insert a star character.
If `c-electric-flag' and `c-syntactic-indentation' are both non-nil, and
the star is the second character of a C style comment starter on a
comment-only-line, indent the line as a comment. If a numeric ARG is
supplied, point is inside a literal, or `c-syntactic-indentation' is nil,
this indentation is inhibited.