Variable: c-indent-comments-syntactically-p
c-indent-comments-syntactically-p is a customizable and buffer-local
variable defined in cc-vars.el.gz.
Documentation
Specifies how M-x indent-for-comment (indent-for-comment) should handle comment-only lines.
When this variable is non-nil, comment-only lines are indented
according to syntactic analysis via c-offsets-alist. Otherwise, the
comment is indented as if it was preceded by code. Note that this
variable does not affect how the normal line indentation treats
comment-only lines.
This is a style variable. Apart from the valid values described
above, it can be set to the symbol set-from-style. In that case,
it takes its value from the style system (see c-default-style and
c-style-alist) when a CC Mode buffer is initialized. Otherwise,
the value set here overrides the style system (there is a variable
c-old-style-variable-behavior that changes this, though).
Source Code
;; Defined in /usr/src/emacs/lisp/progmodes/cc-vars.el.gz
(defcustom-c-stylevar c-indent-comments-syntactically-p nil
"Specifies how \\[indent-for-comment] should handle comment-only lines.
When this variable is non-nil, comment-only lines are indented
according to syntactic analysis via `c-offsets-alist'. Otherwise, the
comment is indented as if it was preceded by code. Note that this
variable does not affect how the normal line indentation treats
comment-only lines."
:type 'boolean
:group 'c)