From: Alan Mackenzie <acm@muc.de>
Date: Sun, 3 Jul 2016 13:11:28 +0000 (+0000)
Subject: Speed up CC Mode fontification with less accurate functions extending region
X-Git-Tag: emacs-26.0.90~1840^2~127
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=4b9ac23960d2998f899287ffcf696ad33b63a69a;p=emacs.git

Speed up CC Mode fontification with less accurate functions extending region

* lisp/progmodes/cc-fonts.el (c-font-lock-cut-off-declarators)
(c-font-lock-enclosing-decls)
* lisp/progmodes/cc-mode.el (c-fl-decl-start): Replace invocations of
c-beginning-of-decl-1 with less accurate invocations of
c-syntactic-skip-backwards to speed up fontification.
---

diff --git a/lisp/progmodes/cc-fonts.el b/lisp/progmodes/cc-fonts.el
index 52f0b0d8696..f122a95feb5 100644
--- a/lisp/progmodes/cc-fonts.el
+++ b/lisp/progmodes/cc-fonts.el
@@ -1522,28 +1522,28 @@ casts and declarations are fontified.  Used on level 2 and higher."
 	(unless (or (eobp)
 		    (looking-at "\\s(\\|\\s)"))
 	  (forward-char))
-	(setq bod-res (car (c-beginning-of-decl-1 decl-search-lim)))
-	(if (and (eq bod-res 'same)
-		 (save-excursion
-		   (c-backward-syntactic-ws)
-		   (eq (char-before) ?\})))
-	    (c-beginning-of-decl-1 decl-search-lim))
-
-	;; We're now putatively at the declaration.
-	(setq paren-state (c-parse-state))
-	;; At top level or inside a "{"?
-	(if (or (not (setq encl-pos
-			   (c-most-enclosing-brace paren-state)))
-		(eq (char-after encl-pos) ?\{))
-	    (progn
-	      (when (looking-at c-typedef-key) ; "typedef"
-		(setq is-typedef t)
-		(goto-char (match-end 0))
-		(c-forward-syntactic-ws))
-	      ;; At a real declaration?
-	      (if (memq (c-forward-type t) '(t known found decltype))
-		  (c-font-lock-declarators limit t is-typedef)))
-	  nil)))))
+	(c-syntactic-skip-backward "^;{}" decl-search-lim t)
+	(when (eq (char-before) ?})
+	  (c-go-list-backward)	; brace block of struct, etc.?
+	  (c-syntactic-skip-backward "^;{}" decl-search-lim t))
+	(when (or (bobp)
+		  (memq (char-before) '(?\; ?{ ?})))
+	  (c-forward-syntactic-ws)
+	  ;; We're now putatively at the declaration.
+	  (setq paren-state (c-parse-state))
+	  ;; At top level or inside a "{"?
+	  (if (or (not (setq encl-pos
+			     (c-most-enclosing-brace paren-state)))
+		  (eq (char-after encl-pos) ?\{))
+	      (progn
+		(when (looking-at c-typedef-key) ; "typedef"
+		  (setq is-typedef t)
+		  (goto-char (match-end 0))
+		  (c-forward-syntactic-ws))
+		;; At a real declaration?
+		(if (memq (c-forward-type t) '(t known found decltype))
+		    (c-font-lock-declarators limit t is-typedef)))))))
+    nil))
 
 (defun c-font-lock-enclosing-decls (limit)
   ;; Fontify the declarators of (nested) declarations we're in the middle of.
@@ -1557,7 +1557,7 @@ casts and declarations are fontified.  Used on level 2 and higher."
   ;; Fontification".
   (let* ((paren-state (c-parse-state))
 	 (decl-search-lim (c-determine-limit 1000))
-	 decl-context in-typedef ps-elt)
+	 in-typedef ps-elt)
     ;; Are we in any nested struct/union/class/etc. braces?
     (while paren-state
       (setq ps-elt (car paren-state)
@@ -1565,15 +1565,18 @@ casts and declarations are fontified.  Used on level 2 and higher."
       (when (and (atom ps-elt)
 		 (eq (char-after ps-elt) ?\{))
 	(goto-char ps-elt)
-	(setq decl-context (c-beginning-of-decl-1 decl-search-lim)
-	      in-typedef (looking-at c-typedef-key))
-	(if in-typedef (c-forward-token-2))
-	(when (and c-opt-block-decls-with-vars-key
-		   (looking-at c-opt-block-decls-with-vars-key))
-	  (goto-char ps-elt)
-	  (when (c-safe (c-forward-sexp))
-	    (c-forward-syntactic-ws)
-	    (c-font-lock-declarators limit t in-typedef)))))))
+	(c-syntactic-skip-backward "^;{}" decl-search-lim)
+	(when (or (bobp)
+		  (memq (char-before) '(?\; ?})))
+	  (c-forward-syntactic-ws)
+	  (setq in-typedef (looking-at c-typedef-key))
+	  (if in-typedef (c-forward-token-2))
+	  (when (and c-opt-block-decls-with-vars-key
+		     (looking-at c-opt-block-decls-with-vars-key))
+	    (goto-char ps-elt)
+	    (when (c-safe (c-forward-sexp))
+	      (c-forward-syntactic-ws)
+	      (c-font-lock-declarators limit t in-typedef))))))))
 
 (defun c-font-lock-raw-strings (limit)
   ;; Fontify C++ raw strings.
diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el
index 5ad7a010641..6711a02c93a 100644
--- a/lisp/progmodes/cc-mode.el
+++ b/lisp/progmodes/cc-mode.el
@@ -1310,9 +1310,10 @@ Note that the style variables are always made local to the buffer."
     (while
 	;; Go to a less nested declaration each time round this loop.
 	(and
-	 (eq (car (c-beginning-of-decl-1 bod-lim)) 'same)
+	 (c-syntactic-skip-backward "^;{}" bod-lim t)
 	 (> (point) bod-lim)
-	 (progn (setq bo-decl (point))
+	 (progn (c-forward-syntactic-ws)
+		(setq bo-decl (point))
 		;; Are we looking at a keyword such as "template" or
 		;; "typedef" which can decorate a type, or the type itself?
 		(when (or (looking-at c-prefix-spec-kwds-re)