Reported by: Óscar Fuentes <ofv <at> wanadoo.es>
Date: Sun, 14 Jul 2019 14:50:02 UTC
Severity: normal
Found in version 27.0.50
Done: Alan Mackenzie <acm <at> muc.de>
Bug is archived. No further changes may be made.
Message #14 received at 36650 <at> debbugs.gnu.org (full text, mbox):
From: Alan Mackenzie <acm <at> muc.de> To: Óscar Fuentes <ofv <at> wanadoo.es> Cc: 36650 <at> debbugs.gnu.org Subject: Re: bug#36650: 27.0.50; CC Mode: Support C++ attributes Date: Sat, 20 Jul 2019 18:02:30 +0000
Hello, Óscar.
On Mon, Jul 15, 2019 at 17:17:27 +0200, Óscar Fuentes wrote:
> Alan Mackenzie <acm <at> muc.de> writes:
> > Yes. I'll have a look at this.
> Thanks.
> >> In general, considering them part of the following token for indentation
> >> purposes and fontifying with some existing or new face should be enough.
> > I will probably end up treating attributes as syntactic whitespace.
> > They have no syntactic connection with the code they are embedded in,
> > any more than macros do.
The patch below (which should apply cleanly to the master branch) is a
first attempt at handling C++ attributes.
> I don't know how syntactic whitespace works on CC Mode, so just in case
> I'll mention that this code
> int foo([[maybe_unused]] int a,
> int b);
> should not be formatted as
> int foo([[maybe_unused]] int a,
> int b);
Understood. Happily, the code appears to do the right thing anyway,
without needing tedious fixing. :-)
Could you please try out this patch, and let me know how well it works.
Thanks!
diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index cb88fc3e58..7963ab0d43 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -1827,45 +1827,122 @@ c-remove-is-and-in-sws
(def-edebug-spec c-remove-is-and-in-sws t)
;; The type of literal position `end' is in a `before-change-functions'
-;; function - one of `c', `c++', `pound', or nil (but NOT `string').
+;; function - one of `c', `c++', `pound', `attribute', or nil (but NOT
+;; `string').
(defvar c-sws-lit-type nil)
-;; A cons (START . STOP) of the bounds of the comment or CPP construct
+;; A cons (START . STOP) of the bounds of the comment or CPP construct, etc.,
;; enclosing END, if any, else nil.
(defvar c-sws-lit-limits nil)
+(defmacro c-looking-at-c++-attribute ()
+ ;; If we're in C++ Mode, and point is at the [[ introducing an attribute,
+ ;; return the position of the end of the attribute, otherwise return nil.
+ ;; The match data are NOT preserved over this macro.
+ `(and
+ (c-major-mode-is 'c++-mode)
+ (looking-at "\\[\\[")
+ (save-excursion
+ (and
+ (c-go-list-forward)
+ (eq (char-before) ?\])
+ (eq (char-before (1- (point))) ?\])
+ (point)))))
+
+;; (defmacro c-enclosing-c++-attribute ()
+(defun c-enclosing-c++-attribute ()
+ ;; If we're in C++ Mode, and point is within a correctly balanced [[ ... ]]
+ ;; attribute structure, return a cons of its starting and ending positions.
+ ;; Otherwise, return nil. We use the c-{in,is}-sws-face text properties for
+ ;; this determination, this macro being intended only for use in the *-sws-*
+ ;; functions and macros. The match data are NOT preserved over this macro.
+ (let (attr-end pos-is-sws)
+ (and
+ (c-major-mode-is 'c++-mode)
+ (> (point) (point-min))
+ (setq pos-is-sws
+ (if (get-text-property (1- (point)) 'c-is-sws)
+ (1- (point))
+ (1- (previous-single-property-change
+ (point) 'c-is-sws nil (point-min)))))
+ (save-excursion
+ (goto-char pos-is-sws)
+ (setq attr-end (c-looking-at-c++-attribute)))
+ (> attr-end (point))
+ (cons pos-is-sws attr-end))))
+
+(defun c-slow-enclosing-c++-attribute ()
+ ;; Like `c-enclosing-c++-attribute', but does not depend on the c-i[ns]-sws
+ ;; properties being set.
+ (and
+ (c-major-mode-is 'c++-mode)
+ (save-excursion
+ (let ((paren-state (c-parse-state))
+ cand)
+ (while
+ (progn
+ (setq cand
+ (catch 'found-cand
+ (while (cdr paren-state)
+ (when (and (numberp (car paren-state))
+ (numberp (cadr paren-state))
+ (eq (car paren-state)
+ (1+ (cadr paren-state)))
+ (eq (char-after (car paren-state)) ?\[)
+ (eq (char-after (cadr paren-state)) ?\[))
+ (throw 'found-cand (cadr paren-state)))
+ (setq paren-state (cdr paren-state)))))
+ (and cand
+ (not
+ (and (c-go-list-forward cand)
+ (eq (char-before) ?\])
+ (eq (char-before (1- (point))) ?\])))))
+ (setq paren-state (cdr paren-state)))
+ (and cand (cons cand (point)))))))
+
(defun c-invalidate-sws-region-before (beg end)
;; Called from c-before-change. BEG and END are the bounds of the change
;; region, the standard parameters given to all before-change-functions.
;;
- ;; Note whether END is inside a comment, CPP construct, or noise macro, and
- ;; if so note its bounds in `c-sws-lit-limits' and type in `c-sws-lit-type'.
+ ;; Note whether END is inside a comment, CPP construct, C++ attribute, or
+ ;; noise macro, and if so note its bounds in `c-sws-lit-limits' and type in
+ ;; `c-sws-lit-type'.
(setq c-sws-lit-type nil
c-sws-lit-limits nil)
- (save-excursion
- (goto-char end)
- (let* ((limits (c-literal-limits))
- (lit-type (c-literal-type limits)))
- (cond
- ((memq lit-type '(c c++))
- (setq c-sws-lit-type lit-type
- c-sws-lit-limits limits))
- ((c-beginning-of-macro)
- (setq c-sws-lit-type 'pound
- c-sws-lit-limits (cons (point)
- (progn (c-end-of-macro) (point)))))
- ((progn (skip-syntax-backward "w_")
- (looking-at c-noise-macro-name-re))
- (setq c-sws-lit-type 'noise
- c-sws-lit-limits (cons (match-beginning 1) (match-end 1))))
- (t))))
- (save-excursion
- (goto-char beg)
- (skip-syntax-backward "w_")
- (when (looking-at c-noise-macro-name-re)
- (setq c-sws-lit-type 'noise)
- (if (consp c-sws-lit-limits)
- (setcar c-sws-lit-limits (match-beginning 1))
- (setq c-sws-lit-limits (cons (match-beginning 1) (match-end 1)))))))
+ (save-match-data
+ (save-excursion
+ (goto-char end)
+ (let* ((limits (c-literal-limits))
+ (lit-type (c-literal-type limits)))
+ (cond
+ ((memq lit-type '(c c++))
+ (setq c-sws-lit-type lit-type
+ c-sws-lit-limits limits))
+ ((c-beginning-of-macro)
+ (setq c-sws-lit-type 'pound
+ c-sws-lit-limits (cons (point)
+ (progn (c-end-of-macro) (point)))))
+ ((eq lit-type 'string))
+ ((setq c-sws-lit-limits (c-enclosing-c++-attribute))
+ (setq c-sws-lit-type 'attribute))
+ ((progn (skip-syntax-backward "w_")
+ (looking-at c-noise-macro-name-re))
+ (setq c-sws-lit-type 'noise
+ c-sws-lit-limits (cons (match-beginning 1) (match-end 1))))
+ (t))))
+ (save-excursion
+ (goto-char beg)
+ (let ((attr-limits (c-enclosing-c++-attribute)))
+ (if attr-limits
+ (if (consp c-sws-lit-limits)
+ (setcar c-sws-lit-limits (car attr-limits))
+ (setq c-sws-lit-limits attr-limits))
+ (skip-syntax-backward "w_")
+ (when (looking-at c-noise-macro-name-re)
+ (setq c-sws-lit-type 'noise)
+ (if (consp c-sws-lit-limits)
+ (setcar c-sws-lit-limits (match-beginning 1))
+ (setq c-sws-lit-limits (cons (match-beginning 1)
+ (match-end 1))))))))))
(defun c-invalidate-sws-region-after-del (beg end _old-len)
;; Text has been deleted, OLD-LEN characters of it starting from position
@@ -1940,7 +2017,7 @@ c-invalidate-sws-region-after
(when (and (eolp) (not (eobp)))
(setq end (1+ (point)))))
- (when (eq c-sws-lit-type 'noise)
+ (when (memq c-sws-lit-type '(noise attribute))
(setq beg (car c-sws-lit-limits)
end (cdr c-sws-lit-limits))) ; This last setting may be redundant.
@@ -1990,6 +2067,8 @@ c-forward-sws
(when (or (looking-at c-syntactic-ws-start)
(and c-opt-cpp-prefix
(looking-at c-noise-macro-name-re))
+ (and (c-major-mode-is 'c++-mode)
+ (looking-at "\\[\\["))
(looking-at c-doc-line-join-re))
(setq rung-end-pos (min (1+ (point)) (point-max)))
@@ -2126,6 +2205,16 @@ c-forward-sws
(goto-char (match-end 1))
(not (eobp)))
+ ((and (c-major-mode-is 'c++-mode)
+ (looking-at "\\[\\[")
+ (save-excursion
+ (and (c-go-list-forward)
+ (eq (char-before) ?\])
+ (eq (char-before (1- (point))) ?\])
+ (setq next-rung-pos (point))))
+ (goto-char next-rung-pos))
+ (not (eobp)))
+
((looking-at c-doc-line-join-re)
;; Skip over a line join in (e.g.) Pike autodoc.
(goto-char (match-end 0))
@@ -2240,6 +2329,13 @@ c-backward-sws
(memq (char-before) c-doc-line-join-end-ch) ; For speed.
(re-search-backward doc-line-join-here
(c-point 'bopl) t))
+ (and
+ (c-major-mode-is 'c++-mode)
+ (eq (char-before) ?\])
+ (eq (char-before (1- (point))) ?\])
+ (save-excursion
+ (and (c-go-list-backward)
+ (looking-at "\\(\\)\\[\\["))))
(progn
(backward-char)
(or (looking-at c-syntactic-ws-end)
@@ -2250,7 +2346,7 @@ c-backward-sws
;; Try to find a rung position in the simple ws preceding point, so that
;; we can get a cache hit even if the last bit of the simple ws has
;; changed recently.
- (setq simple-ws-beg (or (match-end 1) ; Noise macro
+ (setq simple-ws-beg (or (match-end 1) ; Noise macro, etc.
(match-end 0))) ; c-syntactic-ws-end
(skip-chars-backward " \t\n\r\f\v")
(if (setq rung-is-marked (text-property-any
@@ -2388,6 +2484,16 @@ c-backward-sws
(goto-char next-rung-pos)
t)
+ ((and (c-major-mode-is 'c++-mode)
+ (eq (char-before) ?\])
+ (eq (char-before (1- (point))) ?\])
+ (save-excursion
+ (and (c-go-list-backward)
+ (setq next-rung-pos (point))
+ (looking-at "\\[\\["))))
+ (goto-char next-rung-pos)
+ t)
+
((and
(memq (char-before) c-doc-line-join-end-ch) ; For speed.
(re-search-backward doc-line-join-here (c-point 'bopl) t)))))
diff --git a/lisp/progmodes/cc-mode.el b/lisp/progmodes/cc-mode.el
index 5ae7e0f09d..a5e158933b 100644
--- a/lisp/progmodes/cc-mode.el
+++ b/lisp/progmodes/cc-mode.el
@@ -2158,9 +2158,11 @@ c-fl-decl-end
;; count as being in a declarator (on pragmatic grounds).
(goto-char pos)
(let ((lit-start (c-literal-start))
- pos1)
+ enclosing-attribute pos1)
(unless lit-start
(c-backward-syntactic-ws)
+ (when (setq enclosing-attribute (c-slow-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
--
Alan Mackenzie (Nuremberg, Germany).
GNU bug tracking system
Copyright (C) 1999 Darren O. Benham,
1997,2003 nCipher Corporation Ltd,
1994-97 Ian Jackson.