Make typing into incomplete C++ raw strings work, and make it work fast enough

* lisp/progmodes/cc-engine.el (c-beginning-of-macro, c-state-pp-to-literal):
Put `save-match-data' around calls to `looking-at' to enable the use of the
match data in higher level functions.

* lisp/progmodes/cc-fonts.el (c-font-lock-declarations)
(c-font-lock-cut-off-declarators): Use `limit' rather than `(point-max)' as a
limit to speed up handling of C++ raw strings.

2 files changed, 30 insertions, 29 deletions

diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index 595d57756eb..5fa04034585 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -305,7 +305,7 @@ comment at the start of cc-engine.el for more info."
             (forward-line -1))
           (back-to-indentation)
           (if (and (<= (point) here)
-                   (looking-at c-opt-cpp-start)
+                   (save-match-data (looking-at c-opt-cpp-start))
                    (c-macro-is-genuine-p))
               (progn
                 (setq c-macro-cache (cons (point) nil)
@@ -2304,32 +2304,33 @@ comment at the start of cc-engine.el for more info."
   ;; 7 (comment type) and 8 (start of comment/string) (and possibly 9) of
   ;; STATE are valid.
   (save-excursion
-    (let ((s (parse-partial-sexp from to))
-          ty co-st)
-      (cond
-       ((or (nth 3 s) (nth 4 s))        ; in a string or comment
-        (setq ty (cond
-                  ((nth 3 s) 'string)
-                  ((nth 7 s) 'c++)
-                  (t 'c)))
-        (parse-partial-sexp (point) (point-max)
-                            nil            ; TARGETDEPTH
-                            nil            ; STOPBEFORE
-                            s              ; OLDSTATE
-                            'syntax-table) ; stop at end of literal
-        `(,s ,ty (,(nth 8 s) . ,(point))))
-
-       ((and (not not-in-delimiter)     ; inside a comment starter
-             (not (bobp))
-             (progn (backward-char)
-                    (and (not (looking-at "\\s!"))
-                         (looking-at c-comment-start-regexp))))
-        (setq ty (if (looking-at c-block-comment-start-regexp) 'c 'c++)
-              co-st (point))
-        (forward-comment 1)
-        `(,s ,ty (,co-st . ,(point))))
-
-       (t `(,s))))))
+    (save-match-data
+      (let ((s (parse-partial-sexp from to))
+            ty co-st)
+        (cond
+         ((or (nth 3 s) (nth 4 s))      ; in a string or comment
+          (setq ty (cond
+                    ((nth 3 s) 'string)
+                    ((nth 7 s) 'c++)
+                    (t 'c)))
+          (parse-partial-sexp (point) (point-max)
+                              nil          ; TARGETDEPTH
+                              nil          ; STOPBEFORE
+                              s            ; OLDSTATE
+                              'syntax-table) ; stop at end of literal
+          `(,s ,ty (,(nth 8 s) . ,(point))))
+
+         ((and (not not-in-delimiter)   ; inside a comment starter
+               (not (bobp))
+               (progn (backward-char)
+                      (and (not (looking-at "\\s!"))
+                           (looking-at c-comment-start-regexp))))
+          (setq ty (if (looking-at c-block-comment-start-regexp) 'c 'c++)
+                co-st (point))
+          (forward-comment 1)
+          `(,s ,ty (,co-st . ,(point))))
+
+         (t `(,s)))))))
 
 (defun c-state-safe-place (here)
   ;; Return a buffer position before HERE which is "safe", i.e. outside any
diff --git a/lisp/progmodes/cc-fonts.el b/lisp/progmodes/cc-fonts.el
index 65ec5c3f044..3a8c9ec0ec4 100644
--- a/lisp/progmodes/cc-fonts.el
+++ b/lisp/progmodes/cc-fonts.el
@@ -1396,7 +1396,7 @@ casts and declarations are fontified.  Used on level 2 and higher."
                                              'c-decl-id-start)))))
 
                 (c-font-lock-declarators
-                 (point-max) decl-list (cadr decl-or-cast)))
+                 (min limit (point-max)) decl-list (cadr decl-or-cast)))
 
               ;; A declaration has been successfully identified, so do all the
               ;; fontification of types and refs that've been recorded.
@@ -1542,7 +1542,7 @@ casts and declarations are fontified.  Used on level 2 and higher."
                 (c-forward-syntactic-ws))
               ;; At a real declaration?
               (if (memq (c-forward-type t) '(t known found decltype))
-                  (c-font-lock-declarators (point-max) t is-typedef)))
+                  (c-font-lock-declarators limit t is-typedef)))
           nil)))))
 
 (defun c-font-lock-enclosing-decls (limit)