c-backward-comments

c-backward-comments is a compiled Lisp function in `cc-engine.el'.

(c-backward-comments)

Move backward past all preceding whitespace and comments.
Line continuations, i.e. a backslashes followed by line breaks, are
treated as whitespace. The line breaks that end line comments are
considered to be the comment enders, so the point cannot be at the end
of the same line to move over a line comment. Unlike
c-backward-syntactic-ws, this function doesn't move back over
preprocessor directives.

Note that this function might do hidden buffer changes. See the
comment at the start of cc-engine.el for more info.