Amend CC Mode to handle big C++ raw strings correctly.

Problems were caused by such a string spanning jit-lock chunks, and by a flaw
in the +-500 bytes boundaries imposed for macros.

* lisp/progmodes/cc-mode.el (c-extend-region-for-CPP): Check the +-500 byte
macro boundaries here.
(c-extend-font-lock-region-for-macros): Remove the check on the +-500 byte
lower boundary.  Fix the check on the upper boundary.

* lisp/progmodes/cc-fonts.el (c-font-lock-raw-strings): Handle the starting
point already being within a raw string.

* lisp/progmodes/cc-engine.el (c-raw-string-pos)
(c-depropertize-raw-strings-in-region, c-after-change-re-mark-raw-strings):
Modify regexp element "\\{,16\\}" to "\\{0,16\\}" for greater compatibility
with other Emacsen.

3 files changed, 57 insertions, 41 deletions

diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index 48b9e5ebbcd..8648bece70a 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -6039,7 +6039,7 @@ comment at the start of cc-engine.el for more info."
                       (search-backward "\"" (max (- (point) 17) (point-min)) t))
                   (not (bobp)))))
            (eq (char-before) ?R)
-           (looking-at "\"\\([^ ()\\\n\r\t]\\{,16\\}\\)("))
+           (looking-at "\"\\([^ ()\\\n\r\t]\\{0,16\\}\\)("))
         (setq open-quote-pos (point)
               open-paren-pos (match-end 1)
               id (match-string-no-properties 1))
@@ -6121,7 +6121,7 @@ comment at the start of cc-engine.el for more info."
                (concat "\\("                                 ; 1
                        c-anchored-cpp-prefix                 ; 2
                        "\\)\\|\\("                           ; 3
-                       "R\"\\([^ ()\\\n\r\t]\\{,16\\}\\)("   ; 4
+                       "R\"\\([^ ()\\\n\r\t]\\{0,16\\}\\)("  ; 4
                        "\\)")
                finish t))
     (when (save-excursion
@@ -6140,7 +6140,7 @@ comment at the start of cc-engine.el for more info."
           (goto-char (match-end 2))     ; after the "#".
           (while (and (< (point) eom)
                       (c-syntactic-re-search-forward
-                       "R\"\\([^ ()\\\n\r\t]\\{,16\\}\\)(" eom t))
+                       "R\"\\([^ ()\\\n\r\t]\\{0,16\\}\\)(" eom t))
             (c-depropertize-raw-string
              (match-string-no-properties 1) ; id
              (1+ (match-beginning 0))       ; open quote
@@ -6275,7 +6275,7 @@ comment at the start of cc-engine.el for more info."
                  (concat "\\("                                 ; 1
                          c-anchored-cpp-prefix                 ; 2
                          "\\)\\|\\("                           ; 3
-                         "R\"\\([^ ()\\\n\r\t]\\{,16\\}\\)("   ; 4
+                         "R\"\\([^ ()\\\n\r\t]\\{0,16\\}\\)("  ; 4
                          "\\)")
                  c-new-END t))
       (when (save-excursion
@@ -6294,7 +6294,7 @@ comment at the start of cc-engine.el for more info."
             (goto-char (match-end 2))   ; after the "#".
             (while (and (< (point) eom)
                         (c-syntactic-re-search-forward
-                         "R\"\\([^ ()\\\n\r\t]\\{,16\\}\\)(" eom t))
+                         "R\"\\([^ ()\\\n\r\t]\\{0,16\\}\\)(" eom t))
               (c-propertize-raw-string-opener
                (match-string-no-properties 1) ; id
                (1+ (match-beginning 0))       ; open quote
diff --git a/lisp/progmodes/cc-fonts.el b/lisp/progmodes/cc-fonts.el
index dfc2c061217..b45686c81b0 100644
--- a/lisp/progmodes/cc-fonts.el
+++ b/lisp/progmodes/cc-fonts.el
@@ -1542,33 +1542,45 @@ casts and declarations are fontified.  Used on level 2 and higher."
   ;; font-lock-keyword-face.  It always returns NIL to inhibit this and
   ;; prevent a repeat invocation.  See elisp/lispref page "Search-based
   ;; Fontification".
-  (while (search-forward-regexp
-          "R\\(\"\\)\\([^ ()\\\n\r\t]\\{,16\\}\\)(" limit t)
-    (when
-        (or (and (eobp)
-                 (eq (c-get-char-property (1- (point)) 'face)
-                     'font-lock-warning-face))
-            (eq (c-get-char-property (point) 'face) 'font-lock-string-face)
-            (and (equal (c-get-char-property (match-end 2) 'syntax-table) '(1))
-                 (equal (c-get-char-property (match-beginning 1) 'syntax-table)
-                        '(1))))
-      (let ((paren-prop (c-get-char-property (1- (point)) 'syntax-table)))
-        (if paren-prop
-            (progn
-              (c-put-font-lock-face (match-beginning 0) (match-end 0)
-                                    'font-lock-warning-face)
-              (when
-                  (and
-                   (equal paren-prop '(15))
-                   (not (c-search-forward-char-property 'syntax-table '(15) limit)))
-                (goto-char limit)))
-          (c-put-font-lock-face (match-beginning 1) (match-end 2) 'default)
-          (when (search-forward-regexp
-                 (concat ")\\(" (regexp-quote (match-string-no-properties 2))
-                         "\\)\"")
-                 limit t)
-            (c-put-font-lock-face (match-beginning 1) (point)
-                                  'default))))))
+  (let* ((state (c-state-semi-pp-to-literal (point)))
+         (string-start (and (eq (cadr state) 'string)
+                            (car (cddr state))))
+         (raw-id (and string-start
+                      (save-excursion
+                        (goto-char string-start)
+                        (and (eq (char-before) ?R)
+                             (looking-at "\"\\([^ ()\\\n\r\t]\\{0,16\\}\\)(")
+                             (match-string-no-properties 1))))))
+    (while (< (point) limit)
+      (if raw-id
+          (progn
+            (if (search-forward-regexp (concat ")\\(" (regexp-quote raw-id) "\\)\"")
+                                       limit 'limit)
+                (c-put-font-lock-face (match-beginning 1) (point) 'default))
+            (setq raw-id nil))
+
+        (when (search-forward-regexp
+               "R\\(\"\\)\\([^ ()\\\n\r\t]\\{0,16\\}\\)(" limit 'limit)
+          (when
+              (or (and (eobp)
+                       (eq (c-get-char-property (1- (point)) 'face)
+                           'font-lock-warning-face))
+                  (eq (c-get-char-property (point) 'face) 'font-lock-string-face)
+                  (and (equal (c-get-char-property (match-end 2) 'syntax-table) '(1))
+                       (equal (c-get-char-property (match-beginning 1) 'syntax-table)
+                              '(1))))
+            (let ((paren-prop (c-get-char-property (1- (point)) 'syntax-table)))
+              (if paren-prop
+                  (progn
+                    (c-put-font-lock-face (match-beginning 0) (match-end 0)
+                                          'font-lock-warning-face)
+                    (when
+                        (and
+                         (equal paren-prop '(15))
+                         (not (c-search-forward-char-property 'syntax-table '(15) limit)))
+                      (goto-char limit)))
+                (c-put-font-lock-face (match-beginning 1) (match-end 2) 'default)
+                (setq raw-id (match-string-no-properties 2)))))))))
   nil)
 
 (c-lang-defconst c-simple-decl-matchers
diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el
index 6711a02c93a..04d2ed6e8d5 100644
--- a/lisp/progmodes/cc-mode.el
+++ b/lisp/progmodes/cc-mode.el
@@ -924,14 +924,16 @@ Note that the style variables are always made local to the buffer."
   ;; before change function.
   (goto-char c-new-BEG)
   (c-beginning-of-macro)
-  (setq c-new-BEG (point))
+  (when (< (point) c-new-BEG)
+    (setq c-new-BEG (max (point) (c-determine-limit 500 c-new-BEG))))
 
   (goto-char c-new-END)
   (when (c-beginning-of-macro)
     (c-end-of-macro)
     (or (eobp) (forward-char)))  ; Over the terminating NL which may be marked
                                  ; with a c-cpp-delimiter category property
-  (setq c-new-END (point)))
+  (when (> (point) c-new-END)
+    (setq c-new-END (min (point) (c-determine-+ve-limit 500 c-new-END)))))
 
 (defun c-depropertize-new-text (beg end old-len)
   ;; Remove from the new text in (BEG END) any and all text properties which
@@ -959,15 +961,17 @@ Note that the style variables are always made local to the buffer."
   ;; Point is undefined on both entry and exit to this function.  The buffer
   ;; will have been widened on entry.
   ;;
+  ;; c-new-BEG has already been extended in `c-extend-region-for-CPP' so we
+  ;; don't need to repeat the exercise here.
+  ;;
   ;; This function is in the C/C++/ObjC value of `c-before-font-lock-functions'.
   (goto-char endd)
-  (if (c-beginning-of-macro)
-      (c-end-of-macro))
-  (setq c-new-END (max endd c-new-END (point)))
-  ;; Determine the region, (c-new-BEG c-new-END), which will get font
-  ;; locked.  This restricts the region should there be long macros.
-  (setq c-new-BEG (max c-new-BEG (c-determine-limit 500 begg))
-        c-new-END (min c-new-END (c-determine-+ve-limit 500 endd))))
+  (when (c-beginning-of-macro)
+    (c-end-of-macro)
+    ;; Determine the region, (c-new-BEG c-new-END), which will get font
+    ;; locked.  This restricts the region should there be long macros.
+    (setq c-new-END (min (max c-new-END (point))
+                         (c-determine-+ve-limit 500 c-new-END)))))
 
 (defun c-neutralize-CPP-line (beg end)
   ;; BEG and END bound a region, typically a preprocessor line.  Put a