Subject: bug#23818: closed (Re: bug#23818: 25.0.95.3: c-beginning-of-defun misbehaviour)

From: [email-masked] (GNU bug Tracking System)
Date: Sun, 13 Aug 2017 13:19:02 +0000

Your bug report

#23818: 25.0.95.3: c-beginning-of-defun misbehaviour

which was filed against the emacs,cc-mode package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
23818: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=23818
GNU Bug Tracking System
Contact [email-masked] with problems

Subject: Re: bug#23818: 25.0.95.3: c-beginning-of-defun misbehaviour
From: Alan Mackenzie <[email-masked]>
To: Rolf Ade <[email-masked]>
Cc: [email-masked]
Date: Sun, 13 Aug 2017 13:17:18 +0000
List-Id: <debbugs-submit.debbugs.gnu.org>

Hello, Rolf

On Tue, Aug 08, 2017 at 23:42:36 +0200, Rolf Ade wrote:

> Hi Alan,

> while searching for something else I saw it bug is still open. It's
> fixed and good, but just not closed. (Somehow, the following exchanges
> about this bug landed in bug#23775.) Clean up and mark as done.

Yes, there was a bit of confusion back then.  Sorry about that.

With this Email, I'm closing bug #23818.  Thanks for the reminder.

> rolf

-- 
Alan Mackenzie (Nuremberg, Germany).

Subject: 25.0.95.3: c-beginning-of-defun misbehaviour
From: Rolf Ade <[email-masked]>
To: [email-masked]
Date: Wed, 22 Jun 2016 02:19:21 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

The same in 24.5 and 25.0.95.3:

emacs -Q

Open some random emtpy buffer foo.c, put it in c-mode (M-x c-mode) and
insert the following C code:

#define DBG(x) x

DBG(
static void __dbgAttr () {
    /* something */
}
)

int main (void) 
{
    int i;
    i++;
    i++;
    return i;
}

int foo () 
{
    int i;
    i++;
    i++;
    return 1;
}

Put the point inside function main and C-M-home (or M-x
c-beginning-of-defun). Instead of the beginning of main() the point is
here:

_P_DBG(
...

Far away from

_P_int main(void)
...

This isn't "unbalanced braces in preprocessor statements are
horrendously difficult to parse" as in bug #23775, there are no
unbalanced braces everywhere. It's that some code above the code of a
syntactical correct function disturbs c-beginning-of-defun in finding
the beginning of the function.

Put the point into or at the end of function foo, do C-M-home and you
are at the beginning of function foo. Do C-M-home again, and you are not
at the beginning of main, but of the beginning of DBG.

Remove the DBG(). Now C-M-home works, even if the point is inside or the
end of main().