c-up-list-backwardc-up-list-backward is a Lisp macro in `
cc-defs.el'. (c-up-list-backward &optional POS LIMIT) Return the position of the start of the list sexp containing POS, or nil if no such position exists. The point is used if POS is left out. A limit for the search may be given. The start position is assumed to be after it.