CC Mode: Remove annoying background fontification. Should fix bug #52298

Partially revert the commits from 2021-10-24 - 2021-10-26, "CC Mode: Fontify
"found types" which are recognized after being first scanned".

This removes the background fontification which ran off of a 0.1s timer, but
leaves the facility of normal fontification causing the fontification
throughout the buffer of newly found types.

* lisp/progmodes/cc-fonts.el (c-find-types-background)
(c-type-finder-timer-func): Remove.

* lisp/progmodes/cc-mode.el (c-type-finder-timer, c-inhibit-type-finder)
(c-type-finder-pos, c-post-gc-hook): Remove.
(c-leave-cc-mode-mode): Remove the manipulations of c-type-finder-timer and
c-post-gc-hook.
(c-basic-common-init): Remove the manipulations of c-type-finder-pos,
c-type-finder-timer, and c-post-gc-hook.

* lisp/progmodes/cc-vars.el (c-type-finder-time-slot)
(c-type-finder-repeat-time, c-type-finder-chunk-size): Remove.

* doc/misc/cc-mode.texi (Found Types): Remove.  Amend some menu entries.

1 files changed, 1 insertions, 34 deletions

diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el
index f9435c9ceee..ae2ca397661 100644
--- a/lisp/progmodes/cc-mode.el
+++ b/lisp/progmodes/cc-mode.el
@@ -129,16 +129,6 @@
 ;   '
 (require 'cc-fonts) ;)
 
-(defvar c-type-finder-timer nil)
-;; The variable which holds the repeating idle timer which triggers off the
-;; background type finding search.
-
-(defvar c-inhibit-type-finder nil)
-;; When non-nil (set by `c-post-gc-hook') don't perform the type finding
-;; activities the next time `c-type-finder-timer' triggers.  This ensures
-;; keyboard/mouse input will be dealt with when garbage collection is taking a
-;; large portion of CPU time.
-
 ;; The following three really belong to cc-fonts.el, but they are required
 ;; even when cc-fonts.el hasn't been loaded (this happens in XEmacs when
 ;; font-lock-mode is nil).
@@ -197,10 +187,7 @@
 		       c-buffer-is-cc-mode))
 		(throw 'found nil)))
 	  (remove-hook 'post-command-hook 'c-post-command)
-	  (remove-hook 'post-gc-hook 'c-post-gc-hook)
-	  (and c-type-finder-timer
-	       (progn (cancel-timer c-type-finder-timer)
-		      (setq c-type-finder-timer nil)))))
+	  (remove-hook 'post-gc-hook 'c-post-gc-hook)))
       (c-save-buffer-state ()
 	(c-clear-char-properties (point-min) (point-max) 'category)
 	(c-clear-char-properties (point-min) (point-max) 'syntax-table)
@@ -596,12 +583,6 @@ preferably use the `c-mode-menu' language constant directly."
 ;; currently no such text property.
 (make-variable-buffer-local 'c-max-syn-tab-mkr)
 
-;; `c-type-finder-pos' is a marker marking the current place in a CC Mode
-;; buffer which is due to be searched next for "found types", or nil if the
-;; searching is complete.
-(defvar c-type-finder-pos nil)
-(make-variable-buffer-local 'c-type-finder-pos)
-
 (defun c-basic-common-init (mode default-style)
   "Initialize the syntax handling routines and the line breaking/filling code.
 Intended to be used by other packages that embed CC Mode.
@@ -774,17 +755,6 @@ that requires a literal mode spec at compile time."
   ;; c-after-font-lock-init.
   (add-hook 'after-change-functions 'c-after-change nil t)
   (add-hook 'post-command-hook 'c-post-command)
-  (setq c-type-finder-pos
-	(save-restriction
-	  (widen)
-	  (move-marker (make-marker) (point-min))))
-
-  ;; Install the functionality for seeking "found types" at mode startup:
-  (or c-type-finder-timer
-      (setq c-type-finder-timer
-	    (run-at-time
-	     c-type-finder-repeat-time nil #'c-type-finder-timer-func)))
-  (add-hook 'post-gc-hook #'c-post-gc-hook)
 
   (when (boundp 'font-lock-extend-after-change-region-function)
     (set (make-local-variable 'font-lock-extend-after-change-region-function)
@@ -2028,9 +1998,6 @@ Note that this is a strict tail, so won't match, e.g. \"0x....\".")
 	  c-new-id-end nil
 	  c-new-id-is-type nil)))
 
-(defun c-post-gc-hook (&optional _stats) ; For XEmacs.
-  (setq c-inhibit-type-finder t))
-
 (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