Subject: bug#32808: 25.2; Indentation after initializer list C++

From: Alan Mackenzie <[email-masked]>
Date: Sun, 23 Sep 2018 13:27:45 +0000

Hello again, Richard.

On Sat, Sep 22, 2018 at 15:00:02 -0500, Richard Case wrote:
> Hello Alan,

> It is the position of the closing brace on the third line.

OK.  Thanks for reporting this bug!

The problem is a low level CC Mode routine, c-beginning-of-statement-1
(which does what it says) starting at the last open brace on line 2 was
only going back as far as the d of d{""}, being confused by the
initialiser list's brace blocks into thinking that a new statement began
there.

Would you please apply the following patch to your Emacs-25.2 (Note: this
patch likely won't apply cleanly to later versions of Emacs), to the file
...../emacs/lisp/progmodes/cc-engine.el.  Then please byte compile that
file and try it out with your real source code.  (If you want any help
applying the patch or byte compiling, feel free to send me private
email.)  Finally, please confirm to me that the bug is fixed, or tell me
what's still wrong.

The plan is then to install the fix into the Emacs master and emacs-26
branch.

Thanks!

--- cc-engine.el~	2017-02-03 10:25:44.000000000 +0000
+++ cc-engine.el	2018-09-23 13:01:07.642868851 +0000
@@ -1012,12 +1012,15 @@
 		(let ((before-sws-pos (point))
 		      ;; The end position of the area to search for statement
 		      ;; barriers in this round.
-		      (maybe-after-boundary-pos pos))
+		      (maybe-after-boundary-pos pos)
+		      comma-delimited)
 
 		  ;; Go back over exactly one logical sexp, taking proper
 		  ;; account of macros and escaped EOLs.
 		  (while
 		      (progn
+			(setq comma-delimited (and (not comma-delim)
+						   (eq (char-before) ?\,)))
 			(unless (c-safe (c-backward-sexp) t)
 			  ;; Give up if we hit an unbalanced block.  Since the
 			  ;; stack won't be empty the code below will report a
@@ -1053,10 +1056,23 @@
 			 ;; Just gone back over a brace block?
 			 ((and
 			   (eq (char-after) ?{)
+			   (not comma-delimited)
 			   (not (c-looking-at-inexpr-block lim nil t))
 			   (save-excursion
 			     (c-backward-token-2 1 t nil)
-			     (not (looking-at "=\\([^=]\\|$\\)"))))
+			     (not (looking-at "=\\([^=]\\|$\\)")))
+			   (or
+			    (not c-opt-block-decls-with-vars-key)
+			    (save-excursion
+			      (c-backward-token-2 1 t nil)
+			      (if (and (looking-at c-symbol-start)
+				       (not (looking-at c-keywords-regexp)))
+				  (c-backward-token-2 1 t nil))
+			      (and
+			       (not (looking-at
+				     c-opt-block-decls-with-vars-key))
+			       (or comma-delim
+				   (not (eq (char-after) ?\,)))))))
 			  (save-excursion
 			    (c-forward-sexp) (point)))
 			 ;; Just gone back over some paren block?
@@ -10987,7 +11003,7 @@
 	    (if (eq (point) (c-point 'boi))
 		(c-add-syntax 'brace-list-intro (point))
 	      (setq lim (c-most-enclosing-brace c-state-cache (point)))
-	      (c-beginning-of-statement-1 lim)
+	      (c-beginning-of-statement-1 lim nil nil t)
 	      (c-add-stmt-syntax 'brace-list-intro nil t lim paren-state)))
 
 	   ;; CASE 9D: this is just a later brace-list-entry or

> Thank you.

> On Sat, Sep 22, 2018, 2:51 PM Alan Mackenzie <[email-masked]> wrote:

> > Hello, Richard.

> > In article <[email-masked]> you wrote:

> > > While creating a constructor for my class, I have a multiline
> > > initializer list. For the constructor, the indentation matches that of
> > > the list. Here's an example:

> > > Test::Test(const std::string &a) : a{a}, b{0},
> > >                                    c{"..."}, d{""} {
> > >                 /*notice the indentation*/
> > >          }

[ .... ]

-- 
Alan Mackenzie (Nuremberg, Germany).