Reify the cc-mode-common into an actual parent mode

[Stefan Monnier]

IIRC last conversation, while you disagreed with introducing
a c-derivative-mode (for objc/c++/c), you said you were OK with the idea
of introducing a cc-mode-common.

Here's a corresponding patch.
Any objection?


        Stefan


diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el
index de903b8..bbb96f2 100644
--- a/lisp/progmodes/cc-mode.el
+++ b/lisp/progmodes/cc-mode.el
@@ -238,6 +238,8 @@ control).  See \"cc-mode.el\" for more info."
      ;; incompatible
      (t (error "CC Mode is incompatible with this version of Emacs")))
     map))
+(make-obsolete 'c-make-inherited-keymap
+              "Use make-sparse-keymap + (set-keymap-parent c-mode-base-map); 
or derive from c-mode-common" "26.1")
 
 (defun c-define-abbrev-table (name defs &optional doc)
   ;; Compatibility wrapper for `define-abbrev' which passes a non-nil
@@ -861,6 +863,7 @@ Note that the style variables are always made local to the 
buffer."
   (if (cc-bytecomp-fboundp 'run-mode-hooks)
       `(run-mode-hooks ,@hooks)
     `(progn ,@(mapcar (lambda (hook) `(run-hooks ,hook)) hooks))))
+(make-obsolete 'c-run-mode-hooks "derive your mode from c-common-mode" "26.1")
 
 
 ;;; Change hooks, linking with Font Lock and electric-indent-mode.
@@ -1431,6 +1434,17 @@ This function is called from `c-common-init', once per 
mode initialization."
     (c-update-modeline)))
 
 
+(defvar c-mode-common-map c-mode-base-map)
+
+(define-derived-mode c-mode-common prog-mode "CC-common"
+  "Pseudo major mode, parent of all modes using the CC engine."
+  ;; We want to update the mode-line but *after* the major mode's hooks
+  ;; have been run.
+  :after-hook (c-update-modeline)
+  (c-initialize-cc-mode t)
+  (setq abbrev-mode t)  ;; Used for c-electric-continued-statement!
+  )
+
 ;; Support for C
 
 (defvar c-mode-syntax-table
@@ -1443,7 +1457,7 @@ This function is called from `c-common-init', once per 
mode initialization."
   "Abbreviation table used in c-mode buffers.")
 
 (defvar c-mode-map
-  (let ((map (c-make-inherited-keymap)))
+  (let ((map (make-sparse-keymap)))
     ;; Add bindings which are only useful for C.
     (define-key map "\C-c\C-e"  'c-macro-expand)
     map)
@@ -1484,7 +1498,7 @@ This function is called from `c-common-init', once per 
mode initialization."
 (unless (fboundp 'prog-mode) (defalias 'prog-mode 'fundamental-mode))
 
 ;;;###autoload
-(define-derived-mode c-mode prog-mode "C"
+(define-derived-mode c-mode c-mode-common "C"
   "Major mode for editing C code.
 
 To submit a problem report, enter `\\[c-submit-bug-report]' from a
@@ -1500,15 +1514,11 @@ initialization, then `c-mode-hook'.
 Key bindings:
 \\{c-mode-map}"
   :after-hook (progn (c-make-noise-macro-regexps)
-                    (c-make-macro-with-semi-re)
-                    (c-update-modeline))
-  (c-initialize-cc-mode t)
-  (setq abbrev-mode t)
+                    (c-make-macro-with-semi-re))
   (c-init-language-vars-for 'c-mode)
   (c-common-init 'c-mode)
   (easy-menu-add c-c-menu)
-  (cc-imenu-init cc-imenu-c-generic-expression)
-  (c-run-mode-hooks 'c-mode-common-hook))
+  (cc-imenu-init cc-imenu-c-generic-expression))
 
 
 ;; Support for C++
@@ -1524,7 +1534,7 @@ Key bindings:
   "Abbreviation table used in c++-mode buffers.")
 
 (defvar c++-mode-map
-  (let ((map (c-make-inherited-keymap)))
+  (let ((map (make-sparse-keymap)))
     ;; Add bindings which are only useful for C++.
     (define-key map "\C-c\C-e" 'c-macro-expand)
     (define-key map "\C-c:"    'c-scope-operator)
@@ -1537,7 +1547,7 @@ Key bindings:
                  (cons "C++" (c-lang-const c-mode-menu c++)))
 
 ;;;###autoload
-(define-derived-mode c++-mode prog-mode "C++"
+(define-derived-mode c++-mode c-mode-common "C++"
   "Major mode for editing C++ code.
 To submit a problem report, enter `\\[c-submit-bug-report]' from a
 c++-mode buffer.  This automatically sets up a mail buffer with
@@ -1553,15 +1563,11 @@ initialization, then `c++-mode-hook'.
 Key bindings:
 \\{c++-mode-map}"
   :after-hook (progn (c-make-noise-macro-regexps)
-                    (c-make-macro-with-semi-re)
-                    (c-update-modeline))
-  (c-initialize-cc-mode t)
-  (setq abbrev-mode t)
+                    (c-make-macro-with-semi-re))
   (c-init-language-vars-for 'c++-mode)
   (c-common-init 'c++-mode)
   (easy-menu-add c-c++-menu)
-  (cc-imenu-init cc-imenu-c++-generic-expression)
-  (c-run-mode-hooks 'c-mode-common-hook))
+  (cc-imenu-init cc-imenu-c++-generic-expression))
 
 
 ;; Support for Objective-C
@@ -1576,7 +1582,7 @@ Key bindings:
   "Abbreviation table used in objc-mode buffers.")
 
 (defvar objc-mode-map
-  (let ((map (c-make-inherited-keymap)))
+  (let ((map (make-sparse-keymap)))
     ;; Add bindings which are only useful for Objective-C.
     (define-key map "\C-c\C-e" 'c-macro-expand)
     map)
@@ -1588,7 +1594,7 @@ Key bindings:
 ;;;###autoload (add-to-list 'auto-mode-alist '("\\.m\\'" . objc-mode))
 
 ;;;###autoload
-(define-derived-mode objc-mode prog-mode "ObjC"
+(define-derived-mode objc-mode c-mode-common "ObjC"
   "Major mode for editing Objective C code.
 To submit a problem report, enter `\\[c-submit-bug-report]' from an
 objc-mode buffer.  This automatically sets up a mail buffer with
@@ -1604,15 +1610,11 @@ initialization, then `objc-mode-hook'.
 Key bindings:
 \\{objc-mode-map}"
   :after-hook (progn (c-make-noise-macro-regexps)
-                    (c-make-macro-with-semi-re)
-                    (c-update-modeline))
-  (c-initialize-cc-mode t)
-  (setq abbrev-mode t)
+                    (c-make-macro-with-semi-re))
   (c-init-language-vars-for 'objc-mode)
   (c-common-init 'objc-mode)
   (easy-menu-add c-objc-menu)
-  (cc-imenu-init nil 'cc-imenu-objc-function)
-  (c-run-mode-hooks 'c-mode-common-hook))
+  (cc-imenu-init nil 'cc-imenu-objc-function))
 
 
 ;; Support for Java
@@ -1629,7 +1631,7 @@ Key bindings:
   "Abbreviation table used in java-mode buffers.")
 
 (defvar java-mode-map
-  (let ((map (c-make-inherited-keymap)))
+  (let ((map (make-sparse-keymap)))
     ;; Add bindings which are only useful for Java.
     map)
   "Keymap used in java-mode buffers.")
@@ -1647,7 +1649,7 @@ Key bindings:
 ;;;###autoload (add-to-list 'auto-mode-alist '("\\.java\\'" . java-mode))
 
 ;;;###autoload
-(define-derived-mode java-mode prog-mode "Java"
+(define-derived-mode java-mode c-mode-common "Java"
   "Major mode for editing Java code.
 To submit a problem report, enter `\\[c-submit-bug-report]' from a
 java-mode buffer.  This automatically sets up a mail buffer with
@@ -1662,14 +1664,10 @@ initialization, then `java-mode-hook'.
 
 Key bindings:
 \\{java-mode-map}"
-  :after-hook (c-update-modeline)
-  (c-initialize-cc-mode t)
-  (setq abbrev-mode t)
   (c-init-language-vars-for 'java-mode)
   (c-common-init 'java-mode)
   (easy-menu-add c-java-menu)
-  (cc-imenu-init cc-imenu-java-generic-expression)
-  (c-run-mode-hooks 'c-mode-common-hook))
+  (cc-imenu-init cc-imenu-java-generic-expression))
 
 
 ;; Support for CORBA's IDL language
@@ -1682,7 +1680,7 @@ Key bindings:
   "Abbreviation table used in idl-mode buffers.")
 
 (defvar idl-mode-map
-  (let ((map (c-make-inherited-keymap)))
+  (let ((map (make-sparse-keymap)))
     ;; Add bindings which are only useful for IDL.
     map)
   "Keymap used in idl-mode buffers.")
@@ -1693,7 +1691,7 @@ Key bindings:
 ;;;###autoload (add-to-list 'auto-mode-alist '("\\.idl\\'" . idl-mode))
 
 ;;;###autoload
-(define-derived-mode idl-mode prog-mode "IDL"
+(define-derived-mode idl-mode c-mode-common "IDL"
   "Major mode for editing CORBA's IDL, PSDL and CIDL code.
 To submit a problem report, enter `\\[c-submit-bug-report]' from an
 idl-mode buffer.  This automatically sets up a mail buffer with
@@ -1708,13 +1706,13 @@ initialization, then `idl-mode-hook'.
 
 Key bindings:
 \\{idl-mode-map}"
-  :after-hook (c-update-modeline)
-  (c-initialize-cc-mode t)
+  ;; No c-electric-continued-statement here, so we don't need abbrev-mode.
+  (kill-local-variable 'abbrev-mode)
   (c-init-language-vars-for 'idl-mode)
   (c-common-init 'idl-mode)
   (easy-menu-add c-idl-menu)
   ;;(cc-imenu-init cc-imenu-idl-generic-expression) ;TODO
-  (c-run-mode-hooks 'c-mode-common-hook))
+  )
 
 
 ;; Support for Pike
@@ -1729,7 +1727,7 @@ Key bindings:
   "Abbreviation table used in pike-mode buffers.")
 
 (defvar pike-mode-map
-  (let ((map (c-make-inherited-keymap)))
+  (let ((map (make-sparse-keymap)))
     ;; Additional bindings.
     (define-key map "\C-c\C-e" 'c-macro-expand)
     map)
@@ -1742,7 +1740,7 @@ Key bindings:
 ;;;###autoload (add-to-list 'interpreter-mode-alist '("pike" . pike-mode))
 
 ;;;###autoload
-(define-derived-mode pike-mode prog-mode "Pike"
+(define-derived-mode pike-mode c-mode-common "Pike"
   "Major mode for editing Pike code.
 To submit a problem report, enter `\\[c-submit-bug-report]' from a
 pike-mode buffer.  This automatically sets up a mail buffer with
@@ -1757,14 +1755,11 @@ initialization, then `pike-mode-hook'.
 
 Key bindings:
 \\{pike-mode-map}"
-  :after-hook (c-update-modeline)
-  (c-initialize-cc-mode t)
-  (setq        abbrev-mode t)
   (c-init-language-vars-for 'pike-mode)
   (c-common-init 'pike-mode)
   (easy-menu-add c-pike-menu)
   ;;(cc-imenu-init cc-imenu-pike-generic-expression) ;TODO
-  (c-run-mode-hooks 'c-mode-common-hook))
+  )
 
 
 ;; Support for AWK
@@ -1781,7 +1776,7 @@ Key bindings:
   "Abbreviation table used in awk-mode buffers.")
 
 (defvar awk-mode-map
-  (let ((map (c-make-inherited-keymap)))
+  (let ((map (make-sparse-keymap)))
     ;; Add bindings which are only useful for awk.
     (define-key map "#" 'self-insert-command);Overrides electric parent 
binding.
     (define-key map "/" 'self-insert-command);Overrides electric parent 
binding.
@@ -1804,7 +1799,7 @@ Key bindings:
 (declare-function c-awk-unstick-NL-prop "cc-awk" ())
 
 ;;;###autoload
-(define-derived-mode awk-mode prog-mode "AWK"
+(define-derived-mode awk-mode c-mode-common "AWK"
   "Major mode for editing AWK code.
 To submit a problem report, enter `\\[c-submit-bug-report]' from an
 awk-mode buffer.  This automatically sets up a mail buffer with version
@@ -1818,18 +1813,14 @@ initialization, then `awk-mode-hook'.
 
 Key bindings:
 \\{awk-mode-map}"
-  :after-hook (c-update-modeline)
   ;; We need the next line to stop the macro defining
   ;; `awk-mode-syntax-table'.  This would mask the real table which is
   ;; declared in cc-awk.el and hasn't yet been loaded.
   :syntax-table nil
   (require 'cc-awk)                    ; Added 2003/6/10.
-  (c-initialize-cc-mode t)
-  (setq        abbrev-mode t)
   (c-init-language-vars-for 'awk-mode)
   (c-common-init 'awk-mode)
-  (c-awk-unstick-NL-prop)
-  (c-run-mode-hooks 'c-mode-common-hook))
+  (c-awk-unstick-NL-prop))
 
 
 ;; bug reporting