Fix unstable fontification inside templates.

lisp/ChangeLog

+2011-12-23  Alan Mackenzie  <acm@muc.de>
+
+	Fix unstable fontification inside templates.
+
+	* progmodes/cc-langs.el (c-before-font-lock-functions): newly
+	created from the singular version.  The (c c++ objc) entry now
+	additionally has c-set-fl-decl-start.  The other languages (apart
+	from AWK) have that as a single entry.
+
+	* progmodes/cc-fonts.el (c-font-lock-enclosing-decls): The
+	functionality for "local" declarations has been extracted to
+	c-set-fl-decl-start.
+
+	* progmodes/cc-mode.el: (c-common-init, c-after-change): Changes
+	due to pluralisation of c-before-font-lock-functions.
+	(c-set-fl-decl-start): New function, extracted from
+	c-font-lock-enclosing-decls and enhanced.
+
 2011-12-23  Juanma Barranquero  <lekktu@gmail.com>
 
 	* desktop.el (desktop-internal-v2s): Fix typos in docstring (bug#10353).

lisp/progmodes/cc-fonts.el

@@ -1538,25 +1538,8 @@ casts and declarations are fontified.  Used on level 2 and higher."
   ;; prevent a repeat invocation.  See elisp/lispref page "Search-based
   ;; Fontification".
   (let* ((paren-state (c-parse-state))
-	 (start (point))
-	 (bod-lim (max (- (point) 500) (point-min)))
-	 decl-context bo-decl in-typedef type-type ps-elt)
-
-    ;; First, are we actually in a "local" declaration?
-    (setq decl-context (c-beginning-of-decl-1 bod-lim)
-	  bo-decl (point)
-	  in-typedef (looking-at c-typedef-key))
-    (if in-typedef (c-forward-token-2))
-    (when (and (eq (car decl-context) 'same)
-	       (< bo-decl start))
-      ;; Are we genuinely at a type?
-      (setq type-type (c-forward-type t))
-      (if (and type-type
-	       (or (not (eq type-type 'maybe))
-		   (looking-at c-symbol-key)))
-	  (c-font-lock-declarators limit t in-typedef)))
-
-    ;; Secondly, are we in any nested struct/union/class/etc. braces?
+	 decl-context in-typedef ps-elt)
+    ;; Are we in any nested struct/union/class/etc. braces?
     (while paren-state
       (setq ps-elt (car paren-state)
 	    paren-state (cdr paren-state))

lisp/progmodes/cc-langs.el

@@ -485,28 +485,34 @@ The functions are called even when font locking isn't enabled.
 When the mode is initialized, the functions are called with
 parameters \(point-min) and \(point-max).")
 
-(c-lang-defconst c-before-font-lock-function
-  "If non-nil, a function called just before font locking.
-Typically it will extend the region about to be fontified \(see
+(c-lang-defconst c-before-font-lock-functions
+  ;; For documentation see the following c-lang-defvar of the same name.
+  ;; The value here may be a list of functions or a single function.
+  t 'c-set-fl-decl-start
+  (c c++ objc) '(c-neutralize-syntax-in-and-mark-CPP c-set-fl-decl-start)
+  awk 'c-awk-extend-and-syntax-tablify-region)
+(c-lang-defvar c-before-font-lock-functions
+	       (let ((fs (c-lang-const c-before-font-lock-functions)))
+		 (if (listp fs)
+		     fs
+		   (list fs)))
+  "If non-nil, a list of functions called just before font locking.
+Typically they will extend the region about to be fontified \(see
 below) and will set `syntax-table' text properties on the region.
 
-It takes 3 parameters, the BEG, END, and OLD-LEN supplied to
-every after-change function; point is undefined on both entry and
-exit; on entry, the buffer will have been widened and match-data
-will have been saved; the return value is ignored.
+These functions will be run in the order given.  Each of them
+takes 3 parameters, the BEG, END, and OLD-LEN supplied to every
+after-change function; point is undefined on both entry and exit;
+on entry, the buffer will have been widened and match-data will
+have been saved; the return value is ignored.
 
-The function may extend the region to be fontified by setting the
+The functions may extend the region to be fontified by setting the
 buffer local variables c-new-BEG and c-new-END.
 
-The function is called even when font locking is disabled.
+The functions are called even when font locking is disabled.
 
-When the mode is initialized, this function is called with
-parameters \(point-min), \(point-max) and <buffer size>."
-  t nil
-  (c c++ objc) 'c-neutralize-syntax-in-and-mark-CPP
-  awk 'c-awk-extend-and-syntax-tablify-region)
-(c-lang-defvar c-before-font-lock-function
-	       (c-lang-const c-before-font-lock-function))
+When the mode is initialized, these functions are called with
+parameters \(point-min), \(point-max) and <buffer size>.")
 
 
 ;;; Syntactic analysis ("virtual semicolons") for line-oriented languages (AWK).

lisp/progmodes/cc-mode.el

@@ -633,13 +633,13 @@ compatible with old code; callers should always specify it."
     (setq c-new-BEG (point-min))
     (setq c-new-END (point-max))
     (save-excursion
-      (if c-get-state-before-change-functions
-	  (mapc (lambda (fn)
-		  (funcall fn (point-min) (point-max)))
-		c-get-state-before-change-functions))
-      (if c-before-font-lock-function
-	  (funcall c-before-font-lock-function (point-min) (point-max)
-		   (- (point-max) (point-min))))))
+      (mapc (lambda (fn)
+	      (funcall fn (point-min) (point-max)))
+	    c-get-state-before-change-functions)
+      (mapc (lambda (fn)
+	      (funcall fn (point-min) (point-max)
+		       (- (point-max) (point-min))))
+	    c-before-font-lock-functions)))
 
   (set (make-local-variable 'outline-regexp) "[^#\n\^M]")
   (set (make-local-variable 'outline-level) 'c-outline-level)
@@ -881,7 +881,7 @@ Note that the style variables are always made local to the buffer."
   ;; Point is undefined both before and after this function call, the buffer
   ;; has been widened, and match-data saved.  The return value is ignored.
   ;;
-  ;; This function is the C/C++/ObjC value of `c-before-font-lock-function'.
+  ;; This function is in the C/C++/ObjC value of `c-before-font-lock-functions'.
   ;;
   ;; Note: SPEED _MATTERS_ IN THIS FUNCTION!!!
   ;;
@@ -1026,7 +1026,7 @@ Note that the style variables are always made local to the buffer."
   ;; these caches from inside them, and we must thus be sure that this
   ;; has already been executed.
   ;;
-  ;; This calls the language variable c-before-font-lock-function, if non nil.
+  ;; This calls the language variable c-before-font-lock-functions, if non nil.
   ;; This typically sets `syntax-table' properties.
 
   (c-save-buffer-state ()
@@ -1066,9 +1066,53 @@ Note that the style variables are always made local to the buffer."
 	;; larger than (beg end).
 	(setq c-new-BEG beg
 	      c-new-END end)
-	(if c-before-font-lock-function
-	    (save-excursion
-	      (funcall c-before-font-lock-function beg end old-len)))))))
+	(save-excursion
+	  (mapc (lambda (fn)
+		  (funcall fn beg end old-len))
+		c-before-font-lock-functions))))))
+
+(defun c-set-fl-decl-start (beg end old-len)
+  ;; If the beginning of line containing c-new-BEG is in the middle of a
+  ;; "local" declaration (i.e. one which does not start outside of braces
+  ;; enclosing this pos, such as a struct), set c-new-BEG to (at most) the
+  ;; beginning of that declaration.  Note that declarations, in this sense,
+  ;; can be nested.  c-new-BEG will be used later by c-font-lock-declarations.
+  ;;
+  ;; This function is an element of c-before-font-lock-functions, being called
+  ;; (indirectly) from an after-change function.  The after-change-functions'
+  ;; parameters BEG, OLD and OLD-LEN are ignored here.
+  (when font-lock-mode
+    (goto-char (c-point 'bol c-new-BEG))
+    (let ((lit-limits (c-literal-limits))
+	   bod-lim bo-decl)
+
+      (when lit-limits			; Comment or string.
+	(goto-char (car lit-limits)))
+      (setq bod-lim (max (- (point) 500) (point-min)))
+
+      (while
+	  ;; Go to a less nested declaration each time round this loop.
+	  (and
+	   (eq (car (c-beginning-of-decl-1 bod-lim)) 'same)
+	   (progn (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)
+			    (c-forward-type t))
+		    ;; We've found another candidate position.
+		    (setq c-new-BEG (min c-new-BEG bo-decl))
+		    (goto-char bo-decl))
+		  t)
+	   ;; Try and go out a level to search again.
+	   (progn
+	     (c-backward-syntactic-ws bod-lim)
+	     (or (memq (char-before) '(?\( ?\[))
+		 (and (eq (char-before) ?\<)
+		      (eq (c-get-char-property
+			   (1- (point)) 'syntax-table)
+			  c-<-as-paren-syntax))))
+	   (not (bobp)))
+	(backward-char)))))		; back over (, [, <.
 
 (defun c-after-font-lock-init ()
   ;; Put on `font-lock-mode-hook'.