Make CC Mode and electric-pair-mode work together. This fixes bug #33794

* lisp/progmodes/cc-cmds.el (c-electric-pound, c-electric-slash)
(c-electric-star, c-electric-semi&comma, c-electric-colon, c-electric-lt-gt):
Bind post-self-insert-hook to nil around calls to self-insert-command to
protect against arbitrary functionality confusing CC Mode.
(c-do-brace-electrics): New function, extracted from c-electric-brace and
enhanced.
(c-electric-brace): Bind post-self-insert-hook to nil around the call to
self-insert-command.  When electric-pair-mode is configured, call
electric-pair-post-self-insert-function.  Handle any deletion done by this
function.  Call c-do-brace-electrics for the inserted brace, and perhaps for a
brace inserted by electric-pair-self-insert-function.
(c-electric-paren): Bind post-self-insert-hook to nil around the call to
self-insert-command.  When electric-pair-mode is configured, call
electric-pair-post-self-insert-function.

1 files changed, 183 insertions, 129 deletions

diff --git a/lisp/progmodes/cc-cmds.el b/lisp/progmodes/cc-cmds.el
index a07527e4b8b..78677fefadb 100644
--- a/lisp/progmodes/cc-cmds.el
+++ b/lisp/progmodes/cc-cmds.el
@@ -47,6 +47,7 @@
 ;; Silence the compiler.
 (cc-bytecomp-defvar filladapt-mode)     ; c-fill-paragraph contains a kludge
                                         ; which looks at this.
+(cc-bytecomp-defun electric-pair-post-self-insert-function)
 
 ;; Indentation / Display syntax functions
 (defvar c-fix-backslashes t)
@@ -503,7 +504,8 @@ inside a literal or a macro, nothing special happens."
                           (eq (char-before) ?\\))))
             (c-in-literal)))
       ;; do nothing special
-      (self-insert-command (prefix-numeric-value arg))
+      (let (post-self-insert-hook)      ; Disable random functionality.
+        (self-insert-command (prefix-numeric-value arg)))
     ;; place the pound character at the left edge
     (let ((pos (- (point-max) (point)))
           (bolp (bolp)))
@@ -694,6 +696,134 @@ inside a literal or a macro, nothing special happens."
                             t))))
           (goto-char (- (point-max) pos))))))
 
+(defun c-do-brace-electrics (before after)
+  ;; Point is just after a brace.  Indent the various lines, add any required
+  ;; auto newlines, and apply pertinent clean ups.  It is assumed that the
+  ;; caller has checked that point is at EOL if need be, and that the brace is
+  ;; not in a comment or string, and suchlike.
+  ;;
+  ;; BEFORE and AFTER qualify the newlines required before and after the
+  ;; brace as follows:
+  ;; If
+  ;;  o - nil: insert a newline or not according to `c-hanging-braces-alist'.
+  ;;  o - 'ignore: don't insert a newline.
+  ;;  o - 'assume: insert a newline.
+  ;;
+  ;; The return value has no significance.
+  (let (;; shut this up too
+        (c-echo-syntactic-information-p nil)
+        newlines
+        ln-syntax br-syntax syntax)  ; Syntactic context of the original line,
+                                        ; of the brace itself, of the line the
+                                        ; brace ends up on.
+    (c-save-buffer-state ((c-syntactic-indentation-in-macros t)
+                          (c-auto-newline-analysis t))
+      (setq ln-syntax (c-guess-basic-syntax)))
+    (if c-syntactic-indentation
+        (c-indent-line ln-syntax))
+
+    (when c-auto-newline
+      (backward-char)
+      (setq br-syntax (c-point-syntax)
+            newlines (c-brace-newlines br-syntax))
+
+      ;; Insert the BEFORE newline, if wanted, and reindent the newline.
+      (if (or (and (null before) (memq 'before newlines)
+                   (> (current-column) (current-indentation)))
+              (eq before 'assume))
+          (if c-syntactic-indentation
+              ;; Only a plain newline for now - it's indented
+              ;; after the cleanups when the line has its final
+              ;; appearance.
+              (newline)
+            (c-newline-and-indent)))
+      (forward-char)
+
+      ;; `syntax' is the syntactic context of the line which ends up
+      ;; with the brace on it.
+      (setq syntax (if (memq 'before newlines) br-syntax ln-syntax))
+
+      ;; Do all appropriate clean ups
+      (let ((here (point))
+            (pos (- (point-max) (point)))
+            mbeg mend
+            )
+
+        ;; `}': clean up empty defun braces
+        (when (c-save-buffer-state ()
+                (and (memq 'empty-defun-braces c-cleanup-list)
+                     (eq (c-last-command-char) ?\})
+                     (c-intersect-lists '(defun-close class-close inline-close)
+                                        syntax)
+                     (progn
+                       (forward-char -1)
+                       (c-skip-ws-backward)
+                       (eq (char-before) ?\{))
+                     ;; make sure matching open brace isn't in a comment
+                     (not (c-in-literal))))
+          (delete-region (point) (1- here))
+          (setq here (- (point-max) pos)))
+        (goto-char here)
+
+        ;; `}': compact to a one-liner defun?
+        (save-match-data
+          (when
+              (and (eq (c-last-command-char) ?\})
+                   (memq 'one-liner-defun c-cleanup-list)
+                   (c-intersect-lists '(defun-close) syntax)
+                   (c-try-one-liner))
+            (setq here (- (point-max) pos))))
+
+        ;; `{': clean up brace-else-brace and brace-elseif-brace
+        (when (eq (c-last-command-char) ?\{)
+          (cond
+           ((and (memq 'brace-else-brace c-cleanup-list)
+                 (re-search-backward
+                  (concat "}"
+                          "\\([ \t\n]\\|\\\\\n\\)*"
+                          "else"
+                          "\\([ \t\n]\\|\\\\\n\\)*"
+                          "{"
+                          "\\=")
+                  nil t))
+            (delete-region (match-beginning 0) (match-end 0))
+            (insert-and-inherit "} else {"))
+           ((and (memq 'brace-elseif-brace c-cleanup-list)
+                 (progn
+                   (goto-char (1- here))
+                   (setq mend (point))
+                   (c-skip-ws-backward)
+                   (setq mbeg (point))
+                   (eq (char-before) ?\)))
+                 (zerop (c-save-buffer-state nil (c-backward-token-2 1 t)))
+                 (eq (char-after) ?\()
+                 (re-search-backward
+                  (concat "}"
+                          "\\([ \t\n]\\|\\\\\n\\)*"
+                          "else"
+                          "\\([ \t\n]\\|\\\\\n\\)+"
+                          "if"
+                          "\\([ \t\n]\\|\\\\\n\\)*"
+                          "\\=")
+                  nil t))
+            (delete-region mbeg mend)
+            (goto-char mbeg)
+            (insert ?\ ))))
+
+        (goto-char (- (point-max) pos))
+
+        ;; Indent the line after the cleanups since it might
+        ;; very well indent differently due to them, e.g. if
+        ;; c-indent-one-line-block is used together with the
+        ;; one-liner-defun cleanup.
+        (when c-syntactic-indentation
+          (c-indent-line)))
+
+      ;; does a newline go after the brace?
+      (if (or (and (null after) (memq 'after newlines))
+              (eq after 'assume))
+          (c-newline-and-indent)))))
+
 (defun c-electric-brace (arg)
   "Insert a brace.
 
@@ -716,7 +846,10 @@ settings of `c-cleanup-list' are done."
         ;; We want to inhibit blinking the paren since this would be
         ;; most disruptive.  We'll blink it ourselves later on.
         (old-blink-paren blink-paren-function)
-        blink-paren-function case-fold-search)
+        blink-paren-function case-fold-search
+        (at-eol (looking-at "[ \t]*\\\\?$"))
+        (active-region (and (fboundp 'use-region-p) (use-region-p)))
+        got-pair-} electric-pair-deletion)
 
     (c-save-buffer-state ()
       (setq safepos (c-safe-position (point) (c-parse-state))
@@ -724,128 +857,36 @@ settings of `c-cleanup-list' are done."
 
     ;; Insert the brace.  Note that expand-abbrev might reindent
     ;; the line here if there's a preceding "else" or something.
-    (self-insert-command (prefix-numeric-value arg))
-
-    (when (and c-electric-flag (not literal) (not arg))
-      (if (not (looking-at "[ \t]*\\\\?$"))
-          (if c-syntactic-indentation
-              (indent-according-to-mode))
-
-        (let ( ;; shut this up too
-              (c-echo-syntactic-information-p nil)
-              newlines
-              ln-syntax br-syntax syntax) ; Syntactic context of the original line,
-                        ; of the brace itself, of the line the brace ends up on.
-          (c-save-buffer-state ((c-syntactic-indentation-in-macros t)
-                                (c-auto-newline-analysis t))
-            (setq ln-syntax (c-guess-basic-syntax)))
-          (if c-syntactic-indentation
-              (c-indent-line ln-syntax))
-
-          (when c-auto-newline
-            (backward-char)
-            (setq br-syntax (c-point-syntax)
-                  newlines (c-brace-newlines br-syntax))
-
-            ;; Insert the BEFORE newline, if wanted, and reindent the newline.
-            (if (and (memq 'before newlines)
-                     (> (current-column) (current-indentation)))
-                (if c-syntactic-indentation
-                    ;; Only a plain newline for now - it's indented
-                    ;; after the cleanups when the line has its final
-                    ;; appearance.
-                    (newline)
-                  (c-newline-and-indent)))
+    (let (post-self-insert-hook) ; the only way to get defined functionality
+                                 ; from `self-insert-command'.
+      (self-insert-command (prefix-numeric-value arg)))
+
+    ;; Emulate `electric-pair-mode'.
+    (when (and (boundp 'electric-pair-mode)
+               electric-pair-mode)
+      (let ((size (buffer-size))
+            (c-in-electric-pair-functionality t)
+            post-self-insert-hook)
+        (electric-pair-post-self-insert-function)
+        (setq got-pair-} (and at-eol
+                              (eq (c-last-command-char) ?{)
+                              (eq (char-after) ?}))
+              electric-pair-deletion (< (buffer-size) size))))
+
+    ;; Perform any required CC Mode electric actions.
+    (cond
+     ((or literal arg (not c-electric-flag) active-region))
+     ((not at-eol)
+      (c-indent-line))
+     (electric-pair-deletion
+      (c-indent-line)
+      (c-do-brace-electrics 'ignore nil))
+     (t (c-do-brace-electrics nil nil)
+        (when got-pair-}
+          (save-excursion
             (forward-char)
-
-            ;; `syntax' is the syntactic context of the line which ends up
-            ;; with the brace on it.
-            (setq syntax (if (memq 'before newlines) br-syntax ln-syntax))
-
-            ;; Do all appropriate clean ups
-            (let ((here (point))
-                  (pos (- (point-max) (point)))
-                  mbeg mend
-                  )
-
-              ;; `}': clean up empty defun braces
-              (when (c-save-buffer-state ()
-                      (and (memq 'empty-defun-braces c-cleanup-list)
-                           (eq (c-last-command-char) ?\})
-                           (c-intersect-lists '(defun-close class-close inline-close)
-                                              syntax)
-                           (progn
-                             (forward-char -1)
-                             (c-skip-ws-backward)
-                             (eq (char-before) ?\{))
-                           ;; make sure matching open brace isn't in a comment
-                           (not (c-in-literal))))
-                (delete-region (point) (1- here))
-                (setq here (- (point-max) pos)))
-              (goto-char here)
-
-              ;; `}': compact to a one-liner defun?
-              (save-match-data
-                (when
-                    (and (eq (c-last-command-char) ?\})
-                         (memq 'one-liner-defun c-cleanup-list)
-                         (c-intersect-lists '(defun-close) syntax)
-                         (c-try-one-liner))
-                  (setq here (- (point-max) pos))))
-
-              ;; `{': clean up brace-else-brace and brace-elseif-brace
-              (when (eq (c-last-command-char) ?\{)
-                (cond
-                 ((and (memq 'brace-else-brace c-cleanup-list)
-                       (re-search-backward
-                        (concat "}"
-                                "\\([ \t\n]\\|\\\\\n\\)*"
-                                "else"
-                                "\\([ \t\n]\\|\\\\\n\\)*"
-                                "{"
-                                "\\=")
-                        nil t))
-                  (delete-region (match-beginning 0) (match-end 0))
-                  (insert-and-inherit "} else {"))
-                 ((and (memq 'brace-elseif-brace c-cleanup-list)
-                       (progn
-                         (goto-char (1- here))
-                         (setq mend (point))
-                         (c-skip-ws-backward)
-                         (setq mbeg (point))
-                         (eq (char-before) ?\)))
-                       (zerop (c-save-buffer-state nil (c-backward-token-2 1 t)))
-                       (eq (char-after) ?\()
-                      ; (progn
-                        ; (setq tmp (point))
-                         (re-search-backward
-                          (concat "}"
-                                  "\\([ \t\n]\\|\\\\\n\\)*"
-                                  "else"
-                                  "\\([ \t\n]\\|\\\\\n\\)+"
-                                  "if"
-                                  "\\([ \t\n]\\|\\\\\n\\)*"
-                                  "\\=")
-                          nil t);)
-                       ;(eq (match-end 0) tmp);
-                         )
-                  (delete-region mbeg mend)
-                  (goto-char mbeg)
-                  (insert ?\ ))))
-
-              (goto-char (- (point-max) pos))
-
-              ;; Indent the line after the cleanups since it might
-              ;; very well indent differently due to them, e.g. if
-              ;; c-indent-one-line-block is used together with the
-              ;; one-liner-defun cleanup.
-              (when c-syntactic-indentation
-                (c-indent-line)))
-
-            ;; does a newline go after the brace?
-            (if (memq 'after newlines)
-                (c-newline-and-indent))
-            ))))
+            (c-do-brace-electrics 'assume 'ignore))
+          (c-indent-line))))
 
     ;; blink the paren
     (and (eq (c-last-command-char) ?\})
@@ -903,7 +944,8 @@ is inhibited."
                        c-electric-flag
                        (eq (c-last-command-char) ?/)
                        (eq (char-before) (if literal ?* ?/))))
-    (self-insert-command (prefix-numeric-value arg))
+    (let (post-self-insert-hook)        ; Disable random functionality.
+      (self-insert-command (prefix-numeric-value arg)))
     (if indentp
         (indent-according-to-mode))))
 
@@ -916,7 +958,8 @@ supplied, point is inside a literal, or `c-syntactic-indentation' is nil,
 this indentation is inhibited."
 
   (interactive "*P")
-  (self-insert-command (prefix-numeric-value arg))
+  (let (post-self-insert-hook)          ; Disable random functionality.
+    (self-insert-command (prefix-numeric-value arg)))
   ;; if we are in a literal, or if arg is given do not reindent the
   ;; current line, unless this star introduces a comment-only line.
   (if (c-save-buffer-state ()
@@ -963,7 +1006,8 @@ settings of `c-cleanup-list'."
       (setq lim (c-most-enclosing-brace (c-parse-state))
             literal (c-in-literal lim)))
 
-    (self-insert-command (prefix-numeric-value arg))
+    (let (post-self-insert-hook)        ; Disable random functionality.
+      (self-insert-command (prefix-numeric-value arg)))
 
     (if (and c-electric-flag (not literal) (not arg))
         ;; do all cleanups and newline insertions if c-auto-newline is on.
@@ -1032,7 +1076,8 @@ reindented unless `c-syntactic-indentation' is nil.
          newlines is-scope-op
          ;; shut this up
          (c-echo-syntactic-information-p nil))
-    (self-insert-command (prefix-numeric-value arg))
+    (let (post-self-insert-hook)        ; Disable random functionality.
+      (self-insert-command (prefix-numeric-value arg)))
     ;; Any electric action?
     (if (and c-electric-flag (not literal) (not arg))
         ;; Unless we're at EOL, only re-indentation happens.
@@ -1125,7 +1170,8 @@ numeric argument is supplied, or the point is inside a literal."
   (let ((c-echo-syntactic-information-p nil)
         final-pos found-delim case-fold-search)
 
-    (self-insert-command (prefix-numeric-value arg))
+    (let (post-self-insert-hook)        ; Disable random functionality.
+      (self-insert-command (prefix-numeric-value arg)))
     (setq final-pos (point))
 
 ;;;; 2010-01-31: There used to be code here to put a syntax-table text
@@ -1190,7 +1236,9 @@ newline cleanups are done if appropriate; see the variable `c-cleanup-list'."
         ;; shut this up
         (c-echo-syntactic-information-p nil)
         case-fold-search)
-    (self-insert-command (prefix-numeric-value arg))
+    (let (post-self-insert-hook) ; The only way to get defined functionality
+                                 ; from `self-insert-command'.
+      (self-insert-command (prefix-numeric-value arg)))
 
     (if (and (not arg) (not literal))
         (let* ( ;; We want to inhibit blinking the paren since this will
@@ -1239,6 +1287,12 @@ newline cleanups are done if appropriate; see the variable `c-cleanup-list'."
               (delete-region (match-beginning 0) (match-end 0))
               (insert-and-inherit "} catch (")))
 
+          ;; Apply `electric-pair-mode' stuff.
+          (when (and (boundp 'electric-pair-mode)
+                     electric-pair-mode)
+            (let (post-self-insert-hook)
+              (electric-pair-post-self-insert-function)))
+
           ;; Check for clean-ups at function calls.  These two DON'T need
           ;; `c-electric-flag' or `c-syntactic-indentation' set.
           ;; Point is currently just after the inserted paren.