Implement ' separators in C++ integer literals.

* lisp/progmodes/cc-langs.el (c-get-state-before-change-functions): insert
c-before-after-change-digit-quote into the C++ value.
(c-before-font-lock-functions): Insert c-depropertize-new-text into the values
for all languages.  Insert c-before-after-change-digit-quote into the C++
value.

* lisp/progmodes/cc-mode.el (c-depropertize-CPP): Wrap the function in
c-save-buffer-state.
(c-depropertize-new-text, c-before-after-change-digit-quote): New functions.

2 files changed, 113 insertions, 22 deletions

diff --git a/lisp/progmodes/cc-langs.el b/lisp/progmodes/cc-langs.el
index ba05e81aba3..4d366848998 100644
--- a/lisp/progmodes/cc-langs.el
+++ b/lisp/progmodes/cc-langs.el
@@ -477,6 +477,7 @@ so that all identifiers are recognized as words.")
         c-before-change-check-raw-strings
         c-before-change-check-<>-operators
         c-depropertize-CPP
+        c-before-after-change-digit-quote
         c-invalidate-macro-cache)
   (c objc) '(c-extend-region-for-CPP
              c-depropertize-CPP
@@ -508,18 +509,24 @@ parameters \(point-min) and \(point-max).")
 (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-change-expand-fl-region
-  (c objc) '(c-extend-font-lock-region-for-macros
+  t '(c-depropertize-new-text
+      c-change-expand-fl-region)
+  (c objc) '(c-depropertize-new-text
+             c-extend-font-lock-region-for-macros
              c-neutralize-syntax-in-and-mark-CPP
              c-change-expand-fl-region)
-  c++ '(c-extend-font-lock-region-for-macros
+  c++ '(c-depropertize-new-text
+        c-extend-font-lock-region-for-macros
+        c-before-after-change-digit-quote
         c-after-change-re-mark-raw-strings
         c-neutralize-syntax-in-and-mark-CPP
         c-restore-<>-properties
         c-change-expand-fl-region)
-  java '(c-restore-<>-properties
+  java '(c-depropertize-new-text
+         c-restore-<>-properties
          c-change-expand-fl-region)
-  awk 'c-awk-extend-and-syntax-tablify-region)
+  awk '(c-depropertize-new-text
+        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)
diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el
index dd8d771a66f..80ac08fb9e0 100644
--- a/lisp/progmodes/cc-mode.el
+++ b/lisp/progmodes/cc-mode.el
@@ -892,23 +892,24 @@ Note that the style variables are always made local to the buffer."
   ;; This function is in the C/C++/ObjC values of
   ;; `c-get-state-before-change-functions' and is called exclusively as a
   ;; before change function.
-  (goto-char c-new-BEG)
-  (while (and (< (point) beg)
-              (search-forward-regexp c-anchored-cpp-prefix beg t))
-    (goto-char (match-beginning 1))
-    (let ((m-beg (point)))
-      (c-end-of-macro)
-      (c-clear-char-property-with-value
-       m-beg (min (point) beg) 'syntax-table '(1))))
-
-  (goto-char end)
-  (while (and (< (point) c-new-END)
-              (search-forward-regexp c-anchored-cpp-prefix c-new-END t))
-    (goto-char (match-beginning 1))
-    (let ((m-beg (point)))
-      (c-end-of-macro)
-      (c-clear-char-property-with-value
-       m-beg (min (point) c-new-END) 'syntax-table '(1)))))
+  (c-save-buffer-state ()
+    (goto-char c-new-BEG)
+    (while (and (< (point) beg)
+                (search-forward-regexp c-anchored-cpp-prefix beg t))
+      (goto-char (match-beginning 1))
+      (let ((m-beg (point)))
+        (c-end-of-macro)
+        (c-clear-char-property-with-value
+         m-beg (min (point) beg) 'syntax-table '(1))))
+
+    (goto-char end)
+    (while (and (< (point) c-new-END)
+                (search-forward-regexp c-anchored-cpp-prefix c-new-END t))
+      (goto-char (match-beginning 1))
+      (let ((m-beg (point)))
+        (c-end-of-macro)
+        (c-clear-char-property-with-value
+         m-beg (min (point) c-new-END) 'syntax-table '(1))))))
 
 (defun c-extend-region-for-CPP (beg end)
   ;; Adjust `c-new-BEG', `c-new-END' respectively to the beginning and end of
@@ -932,6 +933,25 @@ Note that the style variables are always made local to the buffer."
                                  ; with a c-cpp-delimiter category property
   (setq c-new-END (point)))
 
+(defun c-depropertize-new-text (beg end old-len)
+  ;; Remove from the new text in (BEG END) any and all text properties which
+  ;; might interfere with CC Mode's proper working.
+  ;;
+  ;; This function is called exclusively as an after-change function.  It
+  ;; appears in the value (for all languages) of
+  ;; `c-before-font-lock-functions'.  The value of point is undefined both on
+  ;; entry and exit, and the return value has no significance.  The parameters
+  ;; BEG, END, and OLD-LEN are the standard ones supplied to all after-change
+  ;; functions.
+  (c-save-buffer-state ()
+    (when (> end beg)
+      (c-clear-char-properties beg end 'syntax-table)
+      (c-clear-char-properties beg end 'category)
+      (c-clear-char-properties beg end 'c-is-sws)
+      (c-clear-char-properties beg end 'c-in-sws)
+      (c-clear-char-properties beg end 'c-type)
+      (c-clear-char-properties beg end 'c-awk-NL-prop))))
+
 (defun c-extend-font-lock-region-for-macros (begg endd old-len)
   ;; Extend the region (c-new-BEG c-new-END) to cover all (possibly changed)
   ;; preprocessor macros; The return value has no significance.
@@ -1042,6 +1062,70 @@ Note that the style variables are always made local to the buffer."
             (forward-line))           ; no infinite loop with, e.g., "#//"
           )))))
 
+(defun c-before-after-change-digit-quote (beg end &optional old-len)
+  ;; This function either removes or applies the punctuation value ('(1)) of
+  ;; the `syntax-table' text property on single quote marks which are
+  ;; separator characters in long integer literals, e.g. "4'294'967'295".  It
+  ;; applies to both decimal/octal and hex literals.  (FIXME (2016-06-10): it
+  ;; should also apply to binary literals.)
+  ;;
+  ;; In both uses of the function, the `syntax-table' properties are
+  ;; removed/applied only on quote marks which appear to be digit separators.
+  ;;
+  ;; Point is undefined on both entry and exit to this function, and the
+  ;; return value has no significance.  The function is called solely as a
+  ;; before-change function (see `c-get-state-before-change-functions') and as
+  ;; an after change function (see `c-before-font-lock-functions', with the
+  ;; parameters BEG, END, and (optionally) OLD-LEN being given the standard
+  ;; values for before/after-change functions.
+  (c-save-buffer-state ((num-begin c-new-BEG) digit-re try-end)
+    (goto-char c-new-END)
+    (when (looking-at "\\(x\\)?[0-9a-fA-F']+")
+      (setq c-new-END (match-end 0)))
+    (goto-char c-new-BEG)
+    (when (looking-at "\\(x?\\)[0-9a-fA-F']")
+      (if (re-search-backward "\\(0x\\)?[0-9a-fA-F]*\\=" nil t)
+          (setq c-new-BEG (point))))
+
+    (while
+        (re-search-forward "[0-9a-fA-F]'[0-9a-fA-F]" c-new-END t)
+      (setq try-end (1- (point)))
+      (re-search-backward "[^0-9a-fA-F']" num-begin t)
+      (setq digit-re
+            (cond
+             ((and (not (bobp)) (eq (char-before) ?0) (memq (char-after) '(?x ?X)))
+              "[0-9a-fA-F]")
+             ((and (eq (char-after (1+ (point))) ?0)
+                   (memq (char-after (+ 2 (point))) '(?b ?B)))
+              "[01]")
+             ((memq (char-after (1+ (point))) '(?0 ?1 ?2 ?3 ?4 ?5 ?6 ?7 ?8 ?9))
+              "[0-9]")
+             (t nil)))
+      (when digit-re
+        (cond ((eq (char-after) ?x) (forward-char))
+              ((looking-at ".?0[Bb]") (goto-char (match-end 0)))
+              ((looking-at digit-re))
+              (t (forward-char)))
+        (when (not (c-in-literal))
+          (let ((num-end             ; End of valid sequence of digits/quotes.
+                 (save-excursion
+                   (re-search-forward
+                    (concat "\\=\\(" digit-re "+'\\)*" digit-re "+") nil t)
+                   (point))))
+            (setq try-end               ; End of sequence of digits/quotes
+                  (save-excursion
+                    (re-search-forward
+                     (concat "\\=\\(" digit-re "\\|'\\)+") nil t)
+                    (point)))
+            (while (re-search-forward
+                    (concat digit-re "\\('\\)" digit-re) num-end t)
+              (if old-len           ; i.e. are we in an after-change function?
+                  (c-put-char-property (match-beginning 1) 'syntax-table '(1))
+                (c-clear-char-property (match-beginning 1) 'syntax-table))
+              (backward-char)))))
+      (goto-char try-end)
+      (setq num-begin (point)))))
+
 (defun c-before-change (beg end)
   ;; Function to be put on `before-change-functions'.  Primarily, this calls
   ;; the language dependent `c-get-state-before-change-functions'.  It is