GNU bug report logs - #63285
30.0.50; CC Mode: K&R argument declaration misdetection after parenthesized type

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Olivier Certner <ocert.dev <at> free.fr>
To: bug-gnu-emacs <at> gnu.org
Subject: 30.0.50;
 CC Mode: K&R argument declaration misdetection after parenthesized type
Date: Thu, 04 May 2023 23:54:49 +0200

[Message part 1 (text/plain, inline)]

Hello,

See attached 2-line reproducer.  E.g., type `C-c C-s' on the second line.

Fix to be attached as soon as the bug is created.

Regards.

-- 
Olivier Certner

[test.c (text/x-csrc, attachment)]

Message #8 received at 63285 <at> debbugs.gnu.org (full text, mbox):

From: Olivier Certner <ocert.dev <at> free.fr>
To: 63285 <at> debbugs.gnu.org
Subject: Re: bug#63285: Acknowledgement (30.0.50;
 CC Mode: K&R argument declaration misdetection after parenthesized type)
Date: Thu, 04 May 2023 23:57:14 +0200

[Message part 1 (text/plain, inline)]

Proposed fix.  Applies on master (b28d44d4226497c4b258).

-- 
Olivier Certner

[0001-CC-Mode-Fix-K-R-argument-declaration-misdetection-af.patch (text/x-patch, attachment)]

Message #11 received at 63285 <at> debbugs.gnu.org (full text, mbox):

From: Olivier Certner <ocert.dev <at> free.fr>
To: 63285 <at> debbugs.gnu.org
Subject: Re: 30.0.50;
 CC Mode: K&R argument declaration misdetection after parenthesized type
Date: Fri, 05 May 2023 00:14:48 +0200

[Message part 1 (text/plain, inline)]

Sorry, I had clobbered the "(+ (point) 1000)" part in the previous patch.

Please use this one instead.

-- 
Olivier Certner

[0001-CC-Mode-Fix-K-R-argument-declaration-misdetection-af.patch (text/x-patch, attachment)]

Message #14 received at 63285 <at> debbugs.gnu.org (full text, mbox):

From: Stefan Kangas <stefankangas <at> gmail.com>
To: Alan Mackenzie <acm <at> muc.de>
Cc: 63285 <at> debbugs.gnu.org, Olivier Certner <ocert.dev <at> free.fr>
Subject: Re: bug#63285: 30.0.50; CC Mode: K&R argument declaration
 misdetection after parenthesized type
Date: Thu, 5 Oct 2023 20:43:24 +0000

Olivier Certner <ocert.dev <at> free.fr> writes:

> Sorry, I had clobbered the "(+ (point) 1000)" part in the previous patch.
>
> Please use this one instead.

Alan, could you please take a look at the below patch?

Thanks in advance.

> From 0515de23d84a48c57b456c6730f826c5d783b965 Mon Sep 17 00:00:00 2001
> From: Olivier Certner <olce.emacs <at> certner.fr>
> Date: Wed, 3 May 2023 11:44:43 +0200
> Subject: [PATCH] CC Mode: Fix K&R argument declaration misdetection after
>  parenthesized type
>
> * lisp/progmodes/cc-engine.el (c-in-knr-argdecl): When trying to loop
> over candidate declarations (between the function declaration's
> identifier list's end and point) to check whether the names of their
> identifiers correspond with that of the identifier list, actually fail
> as soon as stumbling on something other than a declaration instead of
> silently succeeding, which causes some constructs to be erroneously
> recognized as K&R argument declarations.
>
> (Bug#63285)
> ---
>  lisp/progmodes/cc-engine.el | 29 ++++++++++++++++++-----------
>  1 file changed, 18 insertions(+), 11 deletions(-)
>
> diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
> index 8b34daf03c2..27740b4903c 100644
> --- a/lisp/progmodes/cc-engine.el
> +++ b/lisp/progmodes/cc-engine.el
> @@ -12039,17 +12039,24 @@ c-in-knr-argdecl
>  		       ;; Each time around the following checks one
>  		       ;; declaration (which may contain several identifiers).
>  		       (while (and
> -			       (consp (setq decl-or-cast
> -					    (c-forward-decl-or-cast-1
> -					     after-prec-token
> -					     nil ; Or 'arglist ???
> -					     nil)))
> -			       (memq (char-after) '(?\; ?\,))
> -			       (goto-char (car decl-or-cast))
> -			       (save-excursion
> -				 (setq semi-position+1
> -				       (c-syntactic-re-search-forward
> -					";" (+ (point) 1000) t)))
> +			       (or
> +				(and
> +				 (consp (setq decl-or-cast
> +					      (c-forward-decl-or-cast-1
> +					       after-prec-token
> +					       nil ; Or 'arglist ???
> +					       nil)))
> +				 (memq (char-after) '(?\; ?\,))
> +				 (goto-char (car decl-or-cast))
> +				 (save-excursion
> +				   (setq semi-position+1
> +					 (1+ (or
> +					      (c-syntactic-re-search-forward
> +					       ";" (+ (point) 1000) t)
> +					      (1- (point-max)))))))
> +				;; Can't parse declarations correctly,
> +				;; bail out.
> +				(throw 'knr nil))
>  			       (c-do-declarators
>  				semi-position+1 t nil nil
>  				(lambda (id-start id-end _next _not-top
> --
> 2.39.2

Message #19 received at 63285 <at> debbugs.gnu.org (full text, mbox):

From: Alan Mackenzie <acm <at> muc.de>
To: Stefan Kangas <stefankangas <at> gmail.com>
Cc: 63285 <at> debbugs.gnu.org, Olivier Certner <ocert.dev <at> free.fr>
Subject: Re: bug#63285: 30.0.50; CC Mode: K&R argument declaration
 misdetection after parenthesized type
Date: Fri, 6 Oct 2023 09:09:57 +0000

Hello, Stefan.

On Thu, Oct 05, 2023 at 20:43:24 +0000, Stefan Kangas wrote:
> Olivier Certner <ocert.dev <at> free.fr> writes:

> > Sorry, I had clobbered the "(+ (point) 1000)" part in the previous patch.
> >
> > Please use this one instead.

> Alan, could you please take a look at the below patch?

I'm looking at the bug, now.  I'll get back again once I think I
understand it.  ;-)

> Thanks in advance.

[ .... ]

-- 
Alan Mackenzie (Nuremberg, Germany).

Message #22 received at 63285 <at> debbugs.gnu.org (full text, mbox):

From: Alan Mackenzie <acm <at> muc.de>
To: Olivier Certner <ocert.dev <at> free.fr>, Stefan Kangas <stefankangas <at> gmail.com>
Cc: acm <at> muc.de, 63285 <at> debbugs.gnu.org
Subject: Re: bug#63285: 30.0.50; CC Mode: K&R argument declaration
 misdetection after parenthesized type
Date: Fri, 6 Oct 2023 13:18:01 +0000

Hello, Olivier and Stefan.

On Thu, Oct 05, 2023 at 20:43:24 +0000, Stefan Kangas wrote:
> Olivier Certner <ocert.dev <at> free.fr> writes:

> > Sorry, I had clobbered the "(+ (point) 1000)" part in the previous patch.
> >
> > Please use this one instead.

Olivier, thanks for taking the trouble to submit this bug report.  Sorry
it's taken me so long to getting around to looking at it.

> Alan, could you please take a look at the below patch?

> Thanks in advance.

> > From 0515de23d84a48c57b456c6730f826c5d783b965 Mon Sep 17 00:00:00 2001
> > From: Olivier Certner <olce.emacs <at> certner.fr>
> > Date: Wed, 3 May 2023 11:44:43 +0200
> > Subject: [PATCH] CC Mode: Fix K&R argument declaration misdetection after
> >  parenthesized type
> >
> > * lisp/progmodes/cc-engine.el (c-in-knr-argdecl): When trying to loop
> > over candidate declarations (between the function declaration's
> > identifier list's end and point) to check whether the names of their
> > identifiers correspond with that of the identifier list, actually fail
> > as soon as stumbling on something other than a declaration instead of
> > silently succeeding, which causes some constructs to be erroneously
> > recognized as K&R argument declarations.

I don't think this would be quite the right way to go.  It would be too
rigorous in rejecting partially written K&R constructs which might cause
them to be excessively reindented as commas and or semicolons get typed.

It seems that (throw 'knr nil) when the c-forward-decl-or-cast-1 form
fails is sufficient to prevent the wrong recognition of your test file's
line 2 as a K&R declaration.  Please feel free to try out my (simpler)
patch below on your real C code.

Also, I propose adopting your 2-line test file, reindented, as a new
test in the CC Mode test suite.  Please let me know if you'd prefer that
not to happen.

> > (Bug#63285)
> > ---
> >  lisp/progmodes/cc-engine.el | 29 ++++++++++++++++++-----------
> >  1 file changed, 18 insertions(+), 11 deletions(-)
> >
> > diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
> > index 8b34daf03c2..27740b4903c 100644
> > --- a/lisp/progmodes/cc-engine.el
> > +++ b/lisp/progmodes/cc-engine.el
> > @@ -12039,17 +12039,24 @@ c-in-knr-argdecl
> >  		       ;; Each time around the following checks one
> >  		       ;; declaration (which may contain several identifiers).
> >  		       (while (and
> > -			       (consp (setq decl-or-cast
> > -					    (c-forward-decl-or-cast-1
> > -					     after-prec-token
> > -					     nil ; Or 'arglist ???
> > -					     nil)))
> > -			       (memq (char-after) '(?\; ?\,))
> > -			       (goto-char (car decl-or-cast))
> > -			       (save-excursion
> > -				 (setq semi-position+1
> > -				       (c-syntactic-re-search-forward
> > -					";" (+ (point) 1000) t)))
> > +			       (or
> > +				(and
> > +				 (consp (setq decl-or-cast
> > +					      (c-forward-decl-or-cast-1
> > +					       after-prec-token
> > +					       nil ; Or 'arglist ???
> > +					       nil)))
> > +				 (memq (char-after) '(?\; ?\,))
> > +				 (goto-char (car decl-or-cast))
> > +				 (save-excursion
> > +				   (setq semi-position+1
> > +					 (1+ (or
> > +					      (c-syntactic-re-search-forward
> > +					       ";" (+ (point) 1000) t)
> > +					      (1- (point-max)))))))
> > +				;; Can't parse declarations correctly,
> > +				;; bail out.
> > +				(throw 'knr nil))
> >  			       (c-do-declarators
> >  				semi-position+1 t nil nil
> >  				(lambda (id-start id-end _next _not-top
> > --
> > 2.39.2

Here's my amended patch:



diff -r b680bbba3141 cc-engine.el
--- a/cc-engine.el	Fri Sep 29 11:15:58 2023 +0000
+++ b/cc-engine.el	Fri Oct 06 11:22:31 2023 +0000
@@ -12285,11 +12285,14 @@
 		       ;; Each time around the following checks one
 		       ;; declaration (which may contain several identifiers).
 		       (while (and
-			       (consp (setq decl-or-cast
-					    (c-forward-decl-or-cast-1
-					     after-prec-token
-					     nil ; Or 'arglist ???
-					     nil)))
+			       (not (eq (char-after) ?{))
+			       (or
+				(consp (setq decl-or-cast
+					     (c-forward-decl-or-cast-1
+					      after-prec-token
+					      nil ; Or 'arglist ???
+					      nil)))
+				(throw 'knr nil))
 			       (memq (char-after) '(?\; ?\,))
 			       (goto-char (car decl-or-cast))
 			       (save-excursion


-- 
Alan Mackenzie (Nuremberg, Germany).

Message #27 received at 63285-done <at> debbugs.gnu.org (full text, mbox):

From: Alan Mackenzie <acm <at> muc.de>
To: Stefan Kangas <stefankangas <at> gmail.com>
Cc: acm <at> muc.de, 63285-done <at> debbugs.gnu.org
Subject: Re: bug#63285: 30.0.50; CC Mode: K&R argument declaration
 misdetection after parenthesized type
Date: Fri, 13 Oct 2023 14:38:56 +0000

Hello, Stefan.

I've committed a patch which fixes this bug.  I'm now closing it.

-- 
Alan Mackenzie (Nuremberg, Germany).

Message #30 received at 63285-done <at> debbugs.gnu.org (full text, mbox):

From: Stefan Kangas <stefankangas <at> gmail.com>
To: Alan Mackenzie <acm <at> muc.de>
Cc: 63285-done <at> debbugs.gnu.org
Subject: Re: bug#63285: 30.0.50; CC Mode: K&R argument declaration
 misdetection after parenthesized type
Date: Fri, 13 Oct 2023 15:04:37 +0000

Alan Mackenzie <acm <at> muc.de> writes:

> I've committed a patch which fixes this bug.  I'm now closing it.

Thanks!

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