diff options
Diffstat (limited to 'lisp/progmodes/cc-engine.el')
| -rw-r--r-- | lisp/progmodes/cc-engine.el | 44 |
1 files changed, 35 insertions, 9 deletions
diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el index 65e28c11e21..82aee7bdbb9 100644 --- a/lisp/progmodes/cc-engine.el +++ b/lisp/progmodes/cc-engine.el @@ -2612,13 +2612,24 @@ comment at the start of cc-engine.el for more info." (setq c-state-point-min (point-min))) (defun c-append-lower-brace-pair-to-state-cache (from &optional upper-lim) - ;; If there is a brace pair preceding FROM in the buffer (not necessarily - ;; immediately preceding), push a cons onto `c-state-cache' to represent it. - ;; FROM must not be inside a literal. If UPPER-LIM is non-nil, we append - ;; the highest brace pair whose "}" is below UPPER-LIM. + ;; If there is a brace pair preceding FROM in the buffer, at the same level + ;; of nesting (not necessarily immediately preceding), push a cons onto + ;; `c-state-cache' to represent it. FROM must not be inside a literal. If + ;; UPPER-LIM is non-nil, we append the highest brace pair whose "}" is below + ;; UPPER-LIM. ;; ;; Return non-nil when this has been done. ;; + ;; The situation it copes with is this transformation: + ;; + ;; OLD: { (.) {...........} + ;; ^ ^ + ;; FROM HERE + ;; + ;; NEW: { {....} (.) {......... + ;; ^ ^ ^ + ;; LOWER BRACE PAIR HERE or HERE + ;; ;; This routine should be fast. Since it can get called a LOT, we maintain ;; `c-state-brace-pair-desert', a small cache of "failures", such that we ;; reduce the time wasted in repeated fruitless searches in brace deserts. @@ -2637,10 +2648,25 @@ comment at the start of cc-engine.el for more info." (unless (and c-state-brace-pair-desert (eq cache-pos (car c-state-brace-pair-desert)) (<= from (cdr c-state-brace-pair-desert))) - ;; Only search what we absolutely need to: - (if (and c-state-brace-pair-desert - (eq cache-pos (car c-state-brace-pair-desert))) - (narrow-to-region (cdr c-state-brace-pair-desert) (point-max))) + ;; DESERT-LIM. Only search what we absolutely need to, + (let ((desert-lim + (and c-state-brace-pair-desert + (eq cache-pos (car c-state-brace-pair-desert)) + (cdr c-state-brace-pair-desert))) + ;; CACHE-LIM. This limit will be necessary when an opening + ;; paren at `cache-pos' has just had its matching close paren + ;; inserted. `cache-pos' continues to be a search bound, even + ;; though the algorithm below would skip over the new paren + ;; pair. + (cache-lim (and cache-pos (< cache-pos from) cache-pos))) + (narrow-to-region + (cond + ((and desert-lim cache-lim) + (max desert-lim cache-lim)) + (desert-lim) + (cache-lim) + ((point-min))) + (point-max))) ;; In the next pair of nested loops, the inner one moves back past a ;; pair of (mis-)matching parens or brackets; the outer one moves @@ -2674,7 +2700,7 @@ comment at the start of cc-engine.el for more info." (cons new-cons (cdr c-state-cache)))) (t (setq c-state-cache (cons new-cons c-state-cache))))) - ;; We haven't found a brace pair. Record this. + ;; We haven't found a brace pair. Record this in the cache. (setq c-state-brace-pair-desert (cons cache-pos from)))))))) (defsubst c-state-push-any-brace-pair (bra+1 macro-start-or-here) |