Package: emacs;
Reported by: Alan Mackenzie <acm <at> muc.de>
Date: Sat, 30 Jul 2022 13:06:01 UTC
Severity: minor
Done: Alan Mackenzie <acm <at> muc.de>
Bug is archived. No further changes may be made.
Message #17 received at 56841 <at> debbugs.gnu.org (full text, mbox):
From: Alan Mackenzie <acm <at> muc.de> To: Eli Zaretskii <eliz <at> gnu.org>, sacks <at> ucar.edu Cc: 56841 <at> debbugs.gnu.org, acm <at> muc.de Subject: Re: bug#56841: Emacs-28 C Mode: Fontification errors when arglist closing ) is on next line Date: Sun, 31 Jul 2022 15:48:56 +0000
Hello, Eli and Bill.
On Sat, Jul 30, 2022 at 18:10:12 +0300, Eli Zaretskii wrote:
> > Date: Sat, 30 Jul 2022 14:27:53 +0000
> > Cc: 56841 <at> debbugs.gnu.org, sacks <at> ucar.edu, acm <at> muc.de
> > From: Alan Mackenzie <acm <at> muc.de>
> > > Are you saying this is not a bug in CC mode but somewhere else? Or
> > > are you saying that you don't yet know what is the culprit and will
> > > investigate?
> > It is most definitely a bug in CC Mode, and I'm looking at it at the
> > moment.
> Thanks.
> > My feeling right now is that the fix will be too involved to go into the
> > release branch.
> Let's talk when you have a fix. But generally, this doesn't sound
> like a too grave problem to me, especially since there's an easy way
> of asking Emacs to fontify correctly.
Here's a proposed version of the fix, which seems to work. The diff is
probably best perused with diff -b. The patch will apply to both the master
branch and Emacs-28.1.
CC Mode: Fontify args correctly when arglist closing ) is not on the same line
This should fix bug #56841.
* lisp/progmodes/cc-engine.el (c-forward-declarator): Fix an off-by-one
comparing the position after a c-forward-name with a limit.
* lisp/progmodes/cc-mode.el (c-fl-decl-end): Handle correctly point starting
inside a literal. Insert a missing c-backward-syntactic-ws in the handling of
C++ attributes. Better handle point starting inside a [ or (. Tidy up the
handling of syntactic whitespace at the end of the buffer.
diff -r e4e62074b8a6 cc-engine.el
--- a/cc-engine.el Sat Jul 30 09:15:53 2022 +0000
+++ b/cc-engine.el Sun Jul 31 15:39:26 2022 +0000
@@ -9576,7 +9576,7 @@
(or (= paren-depth 0)
(c-safe (goto-char (scan-lists (point) 1 paren-depth))))
- (<= (point) limit)
+ (< (point) limit)
;; Skip over any trailing bit, such as "__attribute__".
(progn
diff -r e4e62074b8a6 cc-mode.el
--- a/cc-mode.el Sat Jul 30 09:15:53 2022 +0000
+++ b/cc-mode.el Sun Jul 31 15:39:26 2022 +0000
@@ -2412,49 +2412,59 @@
(and (/= new-pos pos) new-pos))))
(defun c-fl-decl-end (pos)
- ;; If POS is inside a declarator, return the end of the token that follows
- ;; the declarator, otherwise return nil. POS being in a literal does not
- ;; count as being in a declarator (on pragmatic grounds). POINT is not
- ;; preserved.
+ ;; If POS is inside a declarator, return the end of the paren pair that
+ ;; terminates it, or the token that follows the declarator, otherwise return
+ ;; nil. If there is no such token, the end of the last token in the buffer
+ ;; is used. POS being in a literal is now (2022-07) handled correctly.
+ ;; POINT is not preserved.
(goto-char pos)
(let ((lit-start (c-literal-start))
(lim (c-determine-limit 1000))
enclosing-attribute pos1)
- (unless lit-start
- (c-backward-syntactic-ws
- lim)
- (when (setq enclosing-attribute (c-enclosing-c++-attribute))
- (goto-char (car enclosing-attribute))) ; Only happens in C++ Mode.
- (when (setq pos1 (c-on-identifier))
- (goto-char pos1)
- (let ((lim (save-excursion
- (and (c-beginning-of-macro)
- (progn (c-end-of-macro) (point))))))
- (and (c-forward-declarator lim)
- (if (eq (char-after) ?\()
- (and
- (c-go-list-forward nil lim)
- (progn (c-forward-syntactic-ws lim)
- (not (eobp)))
- (progn
- (if (looking-at c-symbol-char-key)
- ;; Deal with baz (foo((bar)) type var), where
- ;; foo((bar)) is not semantically valid. The result
- ;; must be after var).
- (and
- (goto-char pos)
- (setq pos1 (c-on-identifier))
- (goto-char pos1)
- (progn
- (c-backward-syntactic-ws lim)
- (eq (char-before) ?\())
- (c-fl-decl-end (1- (point))))
- (c-backward-syntactic-ws lim)
- (point))))
- (and (progn (c-forward-syntactic-ws lim)
- (not (eobp)))
+ (if lit-start
+ (goto-char lit-start))
+ (c-backward-syntactic-ws lim)
+ (when (setq enclosing-attribute (c-enclosing-c++-attribute))
+ (goto-char (car enclosing-attribute)) ; Only happens in C++ Mode.
+ (c-backward-syntactic-ws lim))
+ (while (and (> (point) lim)
+ (memq (char-before) '(?\[ ?\()))
+ (backward-char)
+ (c-backward-syntactic-ws lim))
+ (when (setq pos1 (c-on-identifier))
+ (goto-char pos1)
+ (let ((lim (save-excursion
+ (and (c-beginning-of-macro)
+ (progn (c-end-of-macro) (point))))))
+ (and (c-forward-declarator lim)
+ (if (eq (char-after) ?\()
+ (and
+ (c-go-list-forward nil lim)
+ (progn (c-forward-syntactic-ws lim)
+ (not (eobp)))
+ (progn
+ (if (looking-at c-symbol-char-key)
+ ;; Deal with baz (foo((bar)) type var), where
+ ;; foo((bar)) is not semantically valid. The result
+ ;; must be after var).
+ (and
+ (goto-char pos)
+ (setq pos1 (c-on-identifier))
+ (goto-char pos1)
+ (progn
+ (c-backward-syntactic-ws lim)
+ (eq (char-before) ?\())
+ (c-fl-decl-end (1- (point))))
(c-backward-syntactic-ws lim)
- (point)))))))))
+ (point))))
+ (if (progn (c-forward-syntactic-ws lim)
+ (not (eobp)))
+ (c-forward-over-token)
+ (let ((lit-start (c-literal-start)))
+ (when lit-start
+ (goto-char lit-start))
+ (c-backward-syntactic-ws)))
+ (and (>= (point) pos) (point))))))))
(defun c-change-expand-fl-region (_beg _end _old-len)
;; Expand the region (c-new-BEG c-new-END) to an after-change font-lock
--
Alan Mackenzie (Nuremberg, Germany).
GNU bug tracking system
Copyright (C) 1999 Darren O. Benham,
1997,2003 nCipher Corporation Ltd,
1994-97 Ian Jackson.