Function: c-remove-stale-state-cache
c-remove-stale-state-cache is a byte-compiled function defined in
cc-engine.el.gz.
Signature
(c-remove-stale-state-cache START-POINT HERE PPS-POINT)
Source Code
;; Defined in /usr/src/emacs/lisp/progmodes/cc-engine.el.gz
(defun c-remove-stale-state-cache (start-point here pps-point)
;; Remove stale entries from the `c-state-cache', i.e. those which will
;; not be in it when it is amended for position HERE. This may involve
;; replacing a CONS element for a brace pair containing HERE with its car.
;; Additionally, the "outermost" open-brace entry before HERE will be
;; converted to a cons if the matching close-brace is below HERE.
;;
;; START-POINT is a "maximal" "safe position" - there must be no open
;; parens/braces/brackets between START-POINT and HERE.
;;
;; As a second thing, calculate the result of parse-partial-sexp at
;; PPS-POINT, w.r.t. START-POINT. The motivation here is that
;; `c-state-cache-good-pos' may become PPS-POINT, but the caller may need to
;; adjust it to get outside a string/comment. (Sorry about this! The code
;; needs to be FAST).
;;
;; Return a list (GOOD-POS SCAN-BACK-POS CONS-SEPARATED PPS-STATE), where
;; o - GOOD-POS is a position where the new value `c-state-cache' is known
;; to be good (we aim for this to be as high as possible);
;; o - SCAN-BACK-POS, if not nil, indicates there may be a brace pair
;; preceding POS which needs to be recorded in `c-state-cache'. It is a
;; position to scan backwards from. It is the position of the "{" of the
;; last element to be removed from `c-state-cache', when that elt is a
;; cons, otherwise nil.
;; o - CONS-SEPARATED is t when a cons element in `c-state-cache' has been
;; replaced by its car because HERE lies inside the brace pair represented
;; by the cons.
;; o - PPS-STATE is the parse-partial-sexp state at PPS-POINT.
(save-excursion
(save-restriction
(narrow-to-region 1 (point-max))
(let* ((in-macro-start ; start of macro containing HERE or nil.
(save-excursion
(goto-char here)
(and (c-beginning-of-macro)
(point))))
(start-point-actual-macro-start ; Start of macro containing
; start-point or nil
(and (< start-point here)
(save-excursion
(goto-char start-point)
(and (c-beginning-of-macro)
(point)))))
(start-point-actual-macro-end ; End of this macro, (maybe
; HERE), or nil.
(and start-point-actual-macro-start
(save-excursion
(goto-char start-point-actual-macro-start)
(c-end-of-macro)
(point))))
pps-state ; Will be 9 or 10 elements long.
pos
upper-lim ; ,beyond which `c-state-cache' entries are removed
scan-back-pos
cons-separated
pair-beg target-depth)
;; Remove entries beyond HERE. Also remove any entries inside
;; a macro, unless HERE is in the same macro.
(setq upper-lim
(if (or (null c-state-old-cpp-beg)
(and (> here c-state-old-cpp-beg)
(< here c-state-old-cpp-end)))
here
(min here c-state-old-cpp-beg)))
(while (and c-state-cache (>= (c-state-cache-top-lparen) upper-lim))
(setq scan-back-pos (car-safe (car c-state-cache)))
(setq c-state-cache (cdr c-state-cache)))
;; If `upper-lim' is inside the last recorded brace pair, remove its
;; RBrace and indicate we'll need to search backwards for a previous
;; brace pair.
(when (and c-state-cache
(consp (car c-state-cache))
(> (cdar c-state-cache) upper-lim))
(setq c-state-cache (cons (caar c-state-cache) (cdr c-state-cache)))
(setq scan-back-pos (car c-state-cache)
cons-separated t))
;; The next loop jumps forward out of a nested level of parens each
;; time round; the corresponding elements in `c-state-cache' are
;; removed. `pos' is just after the brace-pair or the open paren at
;; (car c-state-cache). There can be no open parens/braces/brackets
;; between `start-point'/`start-point-actual-macro-start' and HERE,
;; due to the interface spec to this function.
(setq pos (if (and start-point-actual-macro-end
(not (eq start-point-actual-macro-start
in-macro-start)))
(1+ start-point-actual-macro-end) ; get outside the macro as
; marked by a `category' text property.
start-point))
(goto-char pos)
(while (and c-state-cache
(or (numberp (car c-state-cache)) ; Have we a { at all?
(cdr c-state-cache))
(< (point) here))
(cond
((null pps-state) ; first time through
(setq target-depth -1))
((eq (car pps-state) target-depth) ; found closing ),},]
(setq target-depth (1- (car pps-state))))
;; Do nothing when we've merely reached pps-point.
)
;; Scan!
(setq pps-state
(c-sc-parse-partial-sexp
(point) (if (< (point) pps-point) pps-point here)
target-depth
nil pps-state))
(when (eq (car pps-state) target-depth)
(setq pos (point)) ; POS is now just after an R-paren/brace.
(cond
((and (consp (car c-state-cache))
(eq (point) (cdar c-state-cache)))
;; We've just moved out of the paren pair containing the brace-pair
;; at (car c-state-cache). `pair-beg' is where the open paren is,
;; and is potentially where the open brace of a cons in
;; c-state-cache will be.
(setq pair-beg (car-safe (cdr c-state-cache))
c-state-cache (cdr-safe (cdr c-state-cache)))) ; remove {}pair + containing Lparen.
((numberp (car c-state-cache))
(setq pair-beg (car c-state-cache)
c-state-cache (cdr c-state-cache))) ; remove this
; containing Lparen
((numberp (cadr c-state-cache))
(setq pair-beg (cadr c-state-cache)
c-state-cache (cddr c-state-cache))) ; Remove a paren pair
; together with enclosed brace pair.
;; (t nil) ; Ignore an unmated Rparen.
)))
(if (< (point) pps-point)
(setq pps-state (c-sc-parse-partial-sexp
(point) pps-point
nil nil ; TARGETDEPTH, STOPBEFORE
pps-state)))
;; If the last paren pair we moved out of was actually a brace pair,
;; insert it into `c-state-cache'.
(when (and pair-beg (eq (char-after pair-beg) ?{))
(if (consp (car-safe c-state-cache))
(setq c-state-cache (cdr c-state-cache)))
(setq c-state-cache (cons (cons pair-beg pos)
c-state-cache)))
(list pos scan-back-pos cons-separated pps-state)))))