[Emacs-diffs] master e6fb9a4: CC Mode: Remedy recent loss in performance

[Alan Mackenzie]

branch: master
commit e6fb9a443f48d7bcf1f56ce2ea526c3fa5b732b0
Author: Alan Mackenzie <address@hidden>
Commit: Alan Mackenzie <address@hidden>

    CC Mode: Remedy recent loss in performance
    
    * lisp/progmodes/cc-engine.el (c-back-over-member-initializers): call
    c-parse-state outside of the narrowing operation.
    
    * lisp/progmodes/cc-fonts.el (c-get-fontification-context)
    (c-font-lock-cut-off-declarators): Replace calls to c-determine-limit with
    crude position calculations for speed.
---
 lisp/progmodes/cc-engine.el | 8 +++++---
 lisp/progmodes/cc-fonts.el  | 8 ++++++--
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index 6598cc6..d3d7a1c 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -8611,10 +8611,11 @@ comment at the start of cc-engine.el for more info."
   ;; the function's arglist.  Otherwise return nil, leaving point unchanged.
   ;; LIMIT, if non-nil, is a limit for the backward search.
   (save-restriction
-    (if limit (narrow-to-region limit (point)))
     (let ((here (point))
-         (paren-state (c-parse-state))
+         (paren-state (c-parse-state)) ; Do this outside the narrowing for
+                                       ; performance reasons.
          pos level-plausible at-top-level res)
+      (if limit (narrow-to-region limit (point)))
       ;; Assume tentatively that we're at the top level.  Try to go back to the
       ;; colon we seek.
       (setq res
@@ -8637,7 +8638,8 @@ comment at the start of cc-engine.el for more info."
 
              (while (and (not (and level-plausible
                                    (setq at-top-level (c-at-toplevel-p))))
-                         (setq pos (c-pull-open-brace paren-state))) ; might 
be a paren.
+                         (setq pos (c-pull-open-brace paren-state)) ; might be 
a paren.
+                         (or (null limit) (>= pos limit)))
                (setq level-plausible
                      (catch 'level
                        (goto-char pos)
diff --git a/lisp/progmodes/cc-fonts.el b/lisp/progmodes/cc-fonts.el
index cef2015..269d2c9 100644
--- a/lisp/progmodes/cc-fonts.el
+++ b/lisp/progmodes/cc-fonts.el
@@ -1204,7 +1204,9 @@ casts and declarations are fontified.  Used on level 2 
and higher."
          ((save-excursion
             (goto-char match-pos)
             (and (memq (char-before match-pos) '(?\( ?\,))
-                 (c-go-up-list-backward match-pos (c-determine-limit 500))
+                 (c-go-up-list-backward match-pos
+                                         ; c-determine-limit is too slow, here.
+                                        (max (- (point) 2000) (point-min)))
                  (eq (char-after) ?\()
                  (let ((type (c-get-char-property (point) 'c-type)))
                    (or (memq type '(c-decl-arg-start c-decl-type-start))
@@ -1605,7 +1607,9 @@ casts and declarations are fontified.  Used on level 2 
and higher."
          c-recognize-knr-p)            ; Strictly speaking, bogus, but it
                                        ; speeds up lisp.h tremendously.
       (save-excursion
-       (when (not (c-back-over-member-initializers (c-determine-limit 2000)))
+       (when (not (c-back-over-member-initializers
+                   (max (- (point) 2000) (point-min)))) ; c-determine-limit
+                                                        ; is too slow, here.
          (unless (or (eobp)
                      (looking-at "\\s(\\|\\s)"))
            (forward-char))