master e43fa98a71: CC Mode: Optimize font-locking stanzas for long raw strings.

[Alan Mackenzie]

branch: master
commit e43fa98a71d228475877a4b8d44b96e10c507ffa
Author: Alan Mackenzie <acm@muc.de>
Commit: Alan Mackenzie <acm@muc.de>

    CC Mode: Optimize font-locking stanzas for long raw strings.
    
    Also replace some regexp searches which had caused regexp engine stack
    overflows with simple end-of-line calls.
    
    * lisp/progmodes/cc-fonts.el (c-make-syntactic-matcher)
    (c-make-font-lock-search-form): Start the generated functions with a 
skipping
    of comments and strings.
    (c-make-font-lock-BO-decl-search-function): Start the generated function 
with
    a (fast) movement to the start of any literal.
    
    * lisp/progmodes/cc-mode.el (c-before-change-check-unbalanced-strings)
    (c-after-change-mark-abnormal-strings): Replace complicated regexp searches
    for end of logical line with basic Lisp functions.
---
 lisp/progmodes/cc-fonts.el | 77 ++++++++++++++++++++++++----------------------
 lisp/progmodes/cc-mode.el  | 11 +++++--
 2 files changed, 49 insertions(+), 39 deletions(-)

diff --git a/lisp/progmodes/cc-fonts.el b/lisp/progmodes/cc-fonts.el
index 625010b04b..2495d21a10 100644
--- a/lisp/progmodes/cc-fonts.el
+++ b/lisp/progmodes/cc-fonts.el
@@ -285,6 +285,7 @@
     (byte-compile
      `(lambda (limit)
        (let (res)
+         (c-skip-comments-and-strings limit)
          (while (and (setq res (re-search-forward ,regexp limit t))
                      (progn
                        (goto-char (match-beginning 0))
@@ -300,43 +301,45 @@
     ;; with HIGHLIGHTS, a list of highlighters as specified on page
     ;; "Search-based Fontification" in the elisp manual.  If CHECK-POINT
     ;; is non-nil, we will check (< (point) limit) in the main loop.
-    `(while
-        ,(if check-point
-             `(and (< (point) limit)
-                   (re-search-forward ,regexp limit t))
-           `(re-search-forward ,regexp limit t))
-       (unless (progn
-                (goto-char (match-beginning 0))
-                (c-skip-comments-and-strings limit))
-        (goto-char (match-end 0))
-        ,@(mapcar
-           (lambda (highlight)
-             (if (integerp (car highlight))
-                 ;; e.g. highlight is (1 font-lock-type-face t)
-                 (progn
-                   (unless (eq (nth 2 highlight) t)
-                     (error
-                      "The override flag must currently be t in %s"
-                      highlight))
-                   (when (nth 3 highlight)
-                     (error
-                      "The laxmatch flag may currently not be set in %s"
-                      highlight))
-                   `(save-match-data
-                      (c-put-font-lock-face
-                       (match-beginning ,(car highlight))
-                       (match-end ,(car highlight))
-                       ,(elt highlight 1))))
-               ;; highlight is an "ANCHORED HIGHLIGHTER" of the form
-               ;; (ANCHORED-MATCHER PRE-FORM POST-FORM SUBEXP-HIGHLIGHTERS...)
-               (when (nth 3 highlight)
-                 (error "Match highlights currently not supported in %s"
+    `(progn
+       (c-skip-comments-and-strings limit)
+       (while
+          ,(if check-point
+               `(and (< (point) limit)
+                     (re-search-forward ,regexp limit t))
+             `(re-search-forward ,regexp limit t))
+        (unless (progn
+                  (goto-char (match-beginning 0))
+                  (c-skip-comments-and-strings limit))
+          (goto-char (match-end 0))
+          ,@(mapcar
+             (lambda (highlight)
+               (if (integerp (car highlight))
+                   ;; e.g. highlight is (1 font-lock-type-face t)
+                   (progn
+                     (unless (eq (nth 2 highlight) t)
+                       (error
+                        "The override flag must currently be t in %s"
+                        highlight))
+                     (when (nth 3 highlight)
+                       (error
+                        "The laxmatch flag may currently not be set in %s"
                         highlight))
-               `(progn
-                  ,(nth 1 highlight)
-                  (save-match-data ,(car highlight))
-                  ,(nth 2 highlight))))
-           highlights))))
+                     `(save-match-data
+                        (c-put-font-lock-face
+                         (match-beginning ,(car highlight))
+                         (match-end ,(car highlight))
+                         ,(elt highlight 1))))
+                 ;; highlight is an "ANCHORED HIGHLIGHTER" of the form
+                 ;; (ANCHORED-MATCHER PRE-FORM POST-FORM 
SUBEXP-HIGHLIGHTERS...)
+                 (when (nth 3 highlight)
+                   (error "Match highlights currently not supported in %s"
+                          highlight))
+                 `(progn
+                    ,(nth 1 highlight)
+                    (save-match-data ,(car highlight))
+                    ,(nth 2 highlight))))
+             highlights)))))
 
   (defun c-make-font-lock-search-function (regexp &rest highlights)
     ;; This function makes a byte compiled function that works much like
@@ -416,6 +419,8 @@
     ;; lambda more easily.
     (byte-compile
      `(lambda (limit)
+       (let ((lit-start (c-literal-start)))
+         (when lit-start (goto-char lit-start)))
        (let ( ;; The font-lock package in Emacs is known to clobber
              ;; `parse-sexp-lookup-properties' (when it exists).
              (parse-sexp-lookup-properties
diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el
index 70fc1cb73a..ca4df2d1c7 100644
--- a/lisp/progmodes/cc-mode.el
+++ b/lisp/progmodes/cc-mode.el
@@ -1518,7 +1518,10 @@ Note that the style variables are always made local to 
the buffer."
 
       ;; Move to end of logical line (as it will be after the change, or as it
       ;; was before unescaping a NL.)
-      (re-search-forward "\\(?:\\\\\\(?:.\\|\n\\)\\|[^\\\n\r]\\)*" nil t)
+      (while
+         (progn (end-of-line)
+                (eq (char-before) ?\\))
+       (forward-line))
       ;; We're at an EOLL or point-max.
       (if (equal (c-get-char-property (point) 'syntax-table) '(15))
          (if (memq (char-after) '(?\n ?\r))
@@ -1636,8 +1639,10 @@ Note that the style variables are always made local to 
the buffer."
                  (min (1+ end) ; 1+, if we're inside an escaped NL.
                       (point-max))
                end))
-            (re-search-forward "\\(?:\\\\\\(?:.\\|\n\\)\\|[^\\\n\r]\\)*"
-                               nil t)
+            (while
+                (progn (end-of-line)
+                       (eq (char-before) ?\\))
+              (forward-line))
             (point))
           c-new-END))
         s)