CC Mode: On removal of "typedef", remove pertinent types from c-found-types

For this purpose, record the type names declared by typedef in a text
property, c-typedef, on the typedef.  On any change to that "typedef" or a
type, remove the old identifier(s) from c-found-types.

This should fix bug #59671.

* lisp/progmodes/cc-defs.el (c-search-forward-non-nil-char-property): New
macro.

* lisp/progmodes/cc-engine.el (c-forward-decl-or-cast-1): Move the scope of
identifier-start from the "inner" let form to the outer one.  Amend the
return value such that the middle element of the second element is now the
position of the "typedef", not merely non-nil.

* lisp/progmodes/cc-fonts.el (c-font-lock-declarators): Disregard the LIMIT
parameter when fontifying the declarators of a typedef construct.  Also in
this case, set the c-typedef text property on the "typedef" to the list of
declared types.  Amend this list when these declared types change.
(c-font-lock-single-decl): Massage the `types' argument given to
c-font-lock-declarators.
(c-font-lock-cut-off-declarators): Amend to work when the starting point of
the fontification is inside a brace block.

* lisp/progmodes/cc-mode.el (c-before-change-de-typedef)
(c-after-change-de-typedef): New functions.
(c-update-new-id): Replace the erroneous c-end-of-current-token with a clause
containing c-forward-token-2.
(c-before-change): Call c-before-change-de-typedef.
(c-after-change): Call c-after-change-de-typedef.

1 files changed, 39 insertions, 1 deletions

diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el
index b04ed7584c4..330202bb5f9 100644
--- a/lisp/progmodes/cc-mode.el
+++ b/lisp/progmodes/cc-mode.el
@@ -2077,6 +2077,37 @@ with // and /*, not more generic line and block comments."
 		 (not (eobp))))
 	(forward-char))))))
 
+(defun c-before-change-de-typedef (beg end)
+  ;; For each "typedef" starting in (BEG END), remove the defined types from
+  ;; c-found-types
+  (let (prop)
+    (save-excursion
+      (goto-char beg)
+      (while (and (< (point) end)
+		  (setq prop (c-search-forward-non-nil-char-property
+			      'c-typedef)))
+	(dolist (type prop)
+	  (c-unfind-type type))))))
+
+(defun c-after-change-de-typedef (beg end _old-len)
+  ;; For each former "typedef" in (BEG END), remove the defined types from
+  ;; those which are no longer typedefs.
+  (let (prop)
+    (save-excursion
+      (goto-char beg)
+      (c-backward-token-2
+       1 nil (- (point) 20))
+      (while (and (< (point) end)
+		  (setq prop (c-search-forward-non-nil-char-property
+			      'c-typedef end)))
+	(backward-char)
+	(when (or (not (looking-at c-typedef-key))
+		  (<= (match-end 1) beg))
+	  (dolist (type prop)
+	    (c-unfind-type type))
+	  (c-clear-char-property (point) 'c-typedef))
+	(forward-char)))))
+
 (defun c-update-new-id (end)
   ;; Note the bounds of any identifier that END is in or just after, in
   ;; `c-new-id-start' and `c-new-id-end'.  Otherwise set these variables to
@@ -2086,7 +2117,9 @@ with // and /*, not more generic line and block comments."
     (let ((id-beg (c-on-identifier)))
       (setq c-new-id-start id-beg
 	    c-new-id-end (and id-beg
-			      (progn (c-end-of-current-token) (point)))
+			      (progn (goto-char id-beg)
+				     (c-forward-token-2)
+				     (point)))
 	    c-new-id-is-type nil))))
 
 (defun c-post-command ()
@@ -2215,6 +2248,10 @@ with // and /*, not more generic line and block comments."
 							       term-pos)
 			       (buffer-substring-no-properties beg end)))))))
 
+	   ;; If we're about to delete "typedef"s, clear the identifiers from
+	   ;; `c-found-types'.
+	   (c-before-change-de-typedef beg end)
+
 	   (if c-get-state-before-change-functions
 	       (mapc (lambda (fn)
 		       (funcall fn beg end))
@@ -2306,6 +2343,7 @@ with // and /*, not more generic line and block comments."
 	   (c-update-new-id end)
 	   (c-trim-found-types beg end old-len) ; maybe we don't
 					; need all of these.
+	   (c-after-change-de-typedef beg end old-len)
 	   (c-invalidate-sws-region-after beg end old-len)
 	   ;; (c-invalidate-state-cache beg) ; moved to
 	   ;; `c-before-change'.