unofficial mirror of emacs-devel@gnu.org 
 help / color / mirror / code / Atom feed
From: Alan Mackenzie <acm@muc.de>
To: Daniel Colascione <dancol@dancol.org>
Cc: emacs-devel@gnu.org
Subject: Re: cc-mode fontification feels random
Date: Sun, 6 Jun 2021 11:37:47 +0000	[thread overview]
Message-ID: <YLyzi1ABx84M62QJ@ACM> (raw)
In-Reply-To: <86a85d26-75c0-e4a3-e8d3-244c5346dd3a@dancol.org>

Hello, Daniel.

On Fri, Jun 04, 2021 at 11:30:09 -0700, Daniel Colascione wrote:
> On 6/4/21 8:54 AM, Alan Mackenzie wrote:
> >> Is there any *general* way that we can make fontification more robust
> >> and consistent?
> > Like other people have said on the thread, rewriting CC Mode to use an
> > LSP parser.

> > Less drastically, it would be possible to fix the specific bug you
> > allude to, by the user making a list of types and configuring CC Mode
> > with them, rather than attempting to recognise such types.  This feels
> > as though it would be tedious to use, though.

> I understand that cc-mode can't always get it right. It's only 
> asymptotically omniscient. :-) Some deficiencies in highlighting are 
> bound to happen.

> What's striking to me is the inconsistency in the highlighting. None of 
> the types in the std::variant declaration in my screenshot is special. 
> They're all declared in the same file as the std::variant typedef. So 
> why is PrimitiveType fontified while the others aren't?

Because of the order various jit-lock chunks are fontified.  If the
chunk which establishes foo as a type is fontified first, subsequent
fontifications of foo will use font-lock-type-face.  Otherwise, not.

> FWIW, fontification is correct and consistent when I set 
> font-lock-support-mode to nil, so this really does look like another 
> case of getting unlucky with jit-lock block divisions.

Maybe an improvement might come from scanning the buffer for occurrences
of foo after foo has been recognised as a type and entered into the CC
Mode table.  That way, the lack of fontification on foo would be
temporary, at least provided your Emacs is configured to fontify
non-displayed bits of the buffer in the background (which it is by
default).

This might need enhanced support from jit-lock, such as some sort of
signal indicating a buffer has been completly fontified.  I haven't
thought this through, yet.

> Yes, I'm sure that this particular problem is caused by some bug, and
> with the right repro, we can quickly isolate and fix it. But this kind
> of seemingly-inexplicable inconsistent highlighting has been happening
> for years and years now.  There's something fundamental about the way
> cc-mode is written that makes bugs like this keep popping up. Is there
> some internal abstraction we can add, some algorithmic test suite we
> can write, that would make this whole class of bug less likely?

Well, "seemingly-inexplicable inconsistent highlighting" isn't much to
go on.  If this means "problems with types not getting fontified", then
see above.  Otherwise, particulars help.  It may well be that the ad-hoc
parsing method which CC Mode uses is no longer appropriate for the
modern languages it supports; that's what a lot of this thread has been
discussing.  By "internal abstraction" I think you might mean getting
information from a compiler, or building a partial compiler into CC
Mode.  This is surely possible in theory, but in practice?

[ .... ]

-- 
Alan Mackenzie (Nuremberg, Germany).



  reply	other threads:[~2021-06-06 11:37 UTC|newest]

Thread overview: 274+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-04  3:16 cc-mode fontification feels random Daniel Colascione
2021-06-04  6:10 ` Eli Zaretskii
2021-06-04  7:10   ` Theodor Thornhill
2021-06-04 10:08     ` João Távora
2021-06-04 10:39       ` Eli Zaretskii
2021-06-04 10:59         ` Philipp
2021-06-04 11:05           ` João Távora
2021-06-04 11:22             ` Eli Zaretskii
2021-06-04 12:44               ` Dmitry Gutov
2021-06-04 13:46               ` João Távora
2021-06-04 14:11                 ` Eli Zaretskii
2021-06-04 11:18           ` Eli Zaretskii
2021-06-04 16:43       ` Jim Porter
     [not found]         ` <83k0n9l9pv.fsf@gnu.org>
2021-06-04 19:41           ` Jim Porter
2021-06-04 19:53             ` Eli Zaretskii
2021-06-04 20:05               ` Jim Porter
2021-06-04 20:11                 ` Joost Kremers
2021-06-05  6:51                   ` Eli Zaretskii
2021-06-05 10:14                     ` Joost Kremers
2021-06-05 11:31                       ` Eli Zaretskii
2021-06-05 12:12                         ` Joost Kremers
2021-06-05 13:23                     ` Stefan Monnier
2021-06-05 17:08                       ` Óscar Fuentes
2021-06-05 17:31                         ` Stefan Monnier
2021-06-05 17:32                         ` Eli Zaretskii
2021-06-05 18:46                     ` João Távora
2021-06-05  6:41                 ` Eli Zaretskii
2021-06-05  9:32                   ` João Távora
2021-06-05  9:59                     ` Ergus
2021-06-05 11:29                       ` Eli Zaretskii
2021-06-05 11:55                         ` Daniel Colascione
2021-06-05 12:27                           ` Eli Zaretskii
2021-06-05 17:59                             ` Jim Porter
2021-06-05 18:56                               ` Daniel Martín
2021-06-05 12:43                         ` Ergus
2021-06-05 13:59                       ` Remote GUI Emacs really works (was: cc-mode fontification feels random) Óscar Fuentes
2021-06-05 11:25                     ` cc-mode fontification feels random Eli Zaretskii
2021-06-05  9:46                   ` Ergus
2021-06-05 11:27                     ` Eli Zaretskii
2021-06-04 20:14               ` Yuri Khan
2021-06-04 10:25     ` Eli Zaretskii
2021-06-04 10:05   ` Daniel Colascione
2021-06-04 10:22     ` Eli Zaretskii
2021-06-04 10:34       ` João Távora
2021-06-04 10:43         ` Eli Zaretskii
2021-06-04 18:25         ` Stefan Monnier
2021-06-04 18:36           ` Daniel Colascione
2021-06-04 19:11             ` Eli Zaretskii
2021-06-04 19:16               ` Daniel Colascione
2021-06-04 19:26                 ` Eli Zaretskii
2021-06-04 19:33                   ` Daniel Colascione
2021-06-04 19:51                     ` Eli Zaretskii
2021-06-05  0:29             ` Stefan Monnier
2021-06-05  6:32               ` Eli Zaretskii
2021-06-04 19:07           ` Eli Zaretskii
2021-06-04 19:26             ` Daniel Colascione
2021-06-04 19:32               ` Eli Zaretskii
2021-06-04 10:41       ` Eli Zaretskii
2021-06-04 10:42 ` Ergus
2021-06-04 15:54 ` Alan Mackenzie
2021-06-04 18:30   ` Daniel Colascione
2021-06-06 11:37     ` Alan Mackenzie [this message]
2021-06-06 11:57       ` Eli Zaretskii
2021-06-06 12:27         ` Alan Mackenzie
2021-06-06 12:44           ` Eli Zaretskii
2021-06-06 14:19             ` Alan Mackenzie
2021-06-06 17:06               ` Eli Zaretskii
2021-06-06 17:44       ` Stefan Monnier
2021-06-06 18:00         ` Eli Zaretskii
2021-06-06 18:18           ` Stefan Monnier
2021-06-06 18:33             ` Daniel Colascione
2021-06-06 20:24               ` Stefan Monnier
2021-06-06 20:27                 ` Daniel Colascione
2021-06-06 20:38                   ` Stefan Monnier
2021-06-06 19:03             ` Eli Zaretskii
2021-06-06 20:28               ` Stefan Monnier
2021-06-07  7:35                 ` martin rudalics
2021-06-07 13:20                   ` Stefan Monnier
2021-06-07 13:37                     ` Eli Zaretskii
2021-06-08  0:06                       ` Daniel Colascione
2021-06-08 15:16                       ` Stefan Monnier
2021-06-07 15:58                     ` martin rudalics
2021-06-08  4:01                     ` Richard Stallman
2021-06-08 15:29                       ` Stefan Monnier
2021-06-08 15:52                         ` Eli Zaretskii
2021-06-08 16:36                           ` Stefan Monnier
2021-06-08 18:11                             ` Daniel Colascione
2021-06-08 18:25                               ` Eli Zaretskii
2021-06-08 18:28                                 ` Daniel Colascione
2021-06-08 18:54                                   ` Eli Zaretskii
2021-06-09 18:22                                 ` Alan Mackenzie
2021-06-09 18:36                                   ` Eli Zaretskii
2021-06-09 18:51                                     ` Daniel Colascione
2021-06-09 19:04                                       ` Eli Zaretskii
2021-06-09 20:07                                       ` chad
2021-06-10  6:43                                         ` Eli Zaretskii
2021-06-09 20:17                                       ` Dmitry Gutov
2021-06-09 21:03                                     ` Alan Mackenzie
2021-06-10  2:21                                       ` Daniel Colascione
2021-06-10  6:55                                         ` Eli Zaretskii
2021-06-10  6:58                                           ` Daniel Colascione
2021-06-10  7:19                                             ` Eli Zaretskii
2021-06-10  6:39                                       ` Eli Zaretskii
2021-06-10 16:46                                         ` Alan Mackenzie
2021-06-10 17:01                                           ` Eli Zaretskii
2021-06-10 17:07                                             ` Daniel Colascione
2021-06-10 17:22                                               ` Eli Zaretskii
2021-06-10 17:33                                                 ` Daniel Colascione
2021-06-10 17:39                                                   ` Eli Zaretskii
2021-06-10 17:40                                                 ` Óscar Fuentes
2021-06-10 17:44                                                   ` Eli Zaretskii
2021-06-11 16:11                                                 ` Alan Mackenzie
2021-06-11 17:53                                                   ` Eli Zaretskii
2021-06-11 18:02                                                     ` Daniel Colascione
2021-06-11 18:22                                                       ` Eli Zaretskii
2021-06-11 18:28                                                         ` Daniel Colascione
2021-06-11 19:12                                                           ` Alan Mackenzie
2021-06-11 19:23                                                           ` Eli Zaretskii
2021-06-11 18:47                                                         ` Alan Mackenzie
2021-06-11 19:32                                                           ` Eli Zaretskii
2021-06-11 19:46                                                             ` Alan Mackenzie
2021-06-11 19:50                                                               ` Eli Zaretskii
2021-06-11 18:42                                                       ` Stefan Monnier
2021-06-11 19:31                                                         ` Eli Zaretskii
2021-06-11 19:57                                                           ` Stefan Monnier
2021-06-11 23:25                                                             ` Ergus
2021-06-11 23:52                                                               ` Óscar Fuentes
2021-06-12  1:08                                                                 ` Ergus
2021-06-12  3:20                                                                   ` Stefan Monnier
2021-06-12 11:07                                                                     ` Ergus
2021-06-12  6:58                                                                   ` Eli Zaretskii
2021-06-12 11:01                                                                     ` Ergus
2021-06-12 11:25                                                                       ` Eli Zaretskii
2021-06-12 15:04                                                                         ` Ergus
2021-06-12 15:16                                                                           ` Eli Zaretskii
2021-06-12 15:23                                                                             ` Ergus
2021-06-12 15:35                                                                               ` Eli Zaretskii
2021-06-12 14:00                                                                     ` Stefan Monnier
2021-06-12 14:20                                                                       ` Eli Zaretskii
2021-06-12 14:33                                                                         ` Stefan Monnier
2021-06-12 15:06                                                                           ` Eli Zaretskii
2021-06-12 15:46                                                                             ` Stefan Monnier
2021-06-12  6:50                                                                 ` Eli Zaretskii
2021-06-12  5:20                                                               ` Theodor Thornhill
2021-06-12 13:40                                                                 ` Stefan Monnier
2021-06-12 15:56                                                                   ` Theodor Thornhill
2021-06-12 16:59                                                                     ` Ergus
2021-06-12 17:51                                                                       ` Theodor Thornhill
2021-06-12 17:25                                                                     ` Stefan Monnier
2021-06-12 17:53                                                                       ` Theodor Thornhill
2021-06-12 17:54                                                                       ` Ergus
2021-06-12 18:02                                                                       ` Daniel Colascione
2021-06-12 18:39                                                                         ` Ergus
2021-06-12  6:38                                                             ` Eli Zaretskii
2021-06-12 13:44                                                               ` Stefan Monnier
2021-06-12 14:14                                                                 ` Eli Zaretskii
2021-06-11 20:06                                                           ` Alan Mackenzie
2021-06-12  6:44                                                             ` Eli Zaretskii
2021-06-12  8:00                                                               ` Daniel Colascione
2021-06-12  8:08                                                                 ` Eli Zaretskii
2021-06-12  9:31                                                                   ` Alan Mackenzie
2021-06-11 19:48                                                         ` Eli Zaretskii
2021-06-11 18:34                                                     ` Alan Mackenzie
2021-06-10 17:26                                               ` Óscar Fuentes
2021-06-10 17:39                                               ` andrés ramírez
2021-06-10 21:06                                           ` Stefan Monnier
2021-06-11  6:14                                             ` Eli Zaretskii
2021-06-10 15:16                                       ` Ergus
2021-06-10 15:34                                         ` Óscar Fuentes
2021-06-10 19:06                                           ` Ergus
2021-06-10 19:28                                             ` Eli Zaretskii
2021-06-10 21:56                                               ` Ergus
2021-06-10 15:59                                         ` Jim Porter
2021-06-10 21:02                                         ` Stefan Monnier
2021-06-11 20:21                                           ` Ergus
2021-06-11 20:27                                             ` Stefan Monnier
2021-06-11 20:37                                               ` Daniel Colascione
2021-06-11 20:52                                                 ` Stefan Monnier
2021-06-12  6:46                                                   ` Eli Zaretskii
2021-06-12  8:03                                                     ` Daniel Colascione
2021-06-12  8:13                                                       ` Eli Zaretskii
2021-06-12 13:51                                                       ` Stefan Monnier
2021-06-12  8:47                                                   ` Daniele Nicolodi
2021-06-12  8:57                                                     ` tomas
2021-06-12 14:04                                                     ` Stefan Monnier
2021-06-09 19:05                                   ` Daniel Colascione
2021-06-09 19:11                                     ` Eli Zaretskii
2021-06-09 20:20                                     ` Alan Mackenzie
2021-06-09 20:36                                       ` Stefan Monnier
2021-06-10  7:01                                         ` Daniel Colascione
2021-06-10  7:21                                           ` Eli Zaretskii
2021-06-10  2:21                                       ` Daniel Colascione
2021-06-19  9:25                                         ` Alan Mackenzie
2021-06-19 15:24                                           ` Alan Mackenzie
2021-07-09 14:06                                             ` Daniel Colascione
2021-07-11 18:12                                               ` Stephen Leake
2021-07-15 18:13                                                 ` Perry E. Metzger
2021-07-15 22:43                                                   ` Tree Sitter (was Re: cc-mode fontification feels random) Perry E. Metzger
2021-07-19 23:49                                                     ` Stephen Leake
2021-07-20 14:53                                                       ` Perry E. Metzger
2021-07-21  0:04                                                         ` Stephen Leake
2021-07-21  1:28                                                           ` Stefan Monnier
2021-07-21 14:43                                                             ` Perry E. Metzger
2021-07-21 16:21                                                               ` Daniel Colascione
2021-07-21 19:15                                                                 ` Perry E. Metzger
2021-07-22  1:16                                                                   ` Daniel Colascione
2021-07-22 13:18                                                                     ` Perry E. Metzger
2021-07-22 13:49                                                                     ` Yuan Fu
2021-07-24 20:05                                                                     ` [SPAM UNSURE] " Stephen Leake
2021-07-25  0:41                                                                       ` Daniel Colascione
2021-07-26  4:24                                                                         ` [SPAM UNSURE] " Stephen Leake
2021-07-25 18:01                                                                       ` Perry E. Metzger
2021-07-22 14:00                                                           ` Perry E. Metzger
2021-07-24  1:17                                                             ` Richard Stallman
2021-07-25 16:13                                                               ` Stephen Leake
2021-07-25 19:52                                                                 ` Ada (was Re: Tree Sitter) Perry E. Metzger
2021-07-26  5:05                                                                   ` Stephen Leake
2021-07-26  9:42                                                                     ` Stephen Leake
2021-07-26 14:01                                                                       ` Perry E. Metzger
2021-07-26 13:45                                                                     ` Perry E. Metzger
2021-07-27  0:26                                                                   ` Richard Stallman
2021-07-27 12:38                                                                     ` Perry E. Metzger
2021-07-26  2:23                                                                 ` Tree Sitter (was Re: cc-mode fontification feels random) John Yates
2021-07-24 19:59                                                             ` Stephen Leake
2021-07-24 21:21                                                               ` OFF-TOPIC: Ada availability (was: Tree Sitter) Óscar Fuentes
2021-07-25  7:31                                                                 ` tomas
2021-06-08 18:11                             ` cc-mode fontification feels random Eli Zaretskii
2021-06-08 21:25                               ` Stefan Monnier
2021-06-09  3:39                         ` Richard Stallman
2021-06-09  8:34                         ` martin rudalics
2021-06-09 13:14                           ` `open-paren-in-column-0-is-defun-start` (was: cc-mode fontification feels random) Stefan Monnier
2021-06-09 15:15                             ` Yuri Khan
2021-06-09 15:16                               ` Yuri Khan
2021-06-12 17:29                           ` cc-mode fontification feels random João Távora
2021-06-13  8:50                             ` martin rudalics
2021-06-13  9:05                               ` João Távora
2021-06-13  9:39                                 ` martin rudalics
2021-06-13 10:06                                   ` João Távora
2021-06-13 14:52                                     ` martin rudalics
2021-06-13 15:25                                       ` João Távora
2021-06-14  8:29                                         ` martin rudalics
2021-06-14  8:40                                           ` João Távora
2021-06-14  9:00                                             ` martin rudalics
2021-06-14  9:14                                               ` João Távora
2021-06-14 11:28                                           ` Eli Zaretskii
2021-06-14 14:39                                           ` Stefan Monnier
2021-06-15 22:38                                             ` Ergus
2021-06-07 12:08                 ` Eli Zaretskii
2021-06-08 15:22                   ` Stefan Monnier
2021-06-08 15:46                     ` Eli Zaretskii
2021-06-05 20:25   ` Dmitry Gutov
2021-06-06 11:53     ` Alan Mackenzie
2021-06-06 17:08       ` Dmitry Gutov
2021-08-30 18:50 ` [PATCH] " Alan Mackenzie
2021-08-30 19:03   ` Perry E. Metzger
2021-08-30 19:18     ` Alan Mackenzie
2021-08-30 19:25   ` Eli Zaretskii
2021-08-30 19:28     ` Daniel Colascione
2021-08-30 19:37       ` Eli Zaretskii
2021-08-30 20:11       ` Stefan Monnier
2021-08-31 10:54         ` Alan Mackenzie
2021-08-31 13:23           ` Eli Zaretskii
2021-08-31 16:02             ` Alan Mackenzie
2021-08-31 16:21               ` Eli Zaretskii
2021-08-31 16:46                 ` Alan Mackenzie
2021-08-31 17:02                   ` Eli Zaretskii
2021-08-31 18:56           ` Stefan Monnier
2021-08-31 21:17             ` Alan Mackenzie
2021-08-31 21:47               ` Stefan Monnier
2021-10-22 20:13               ` [Committed PATCH] " Alan Mackenzie
2021-10-24 20:18                 ` Alan Mackenzie
2021-08-31 13:18         ` [PATCH] " Eli Zaretskii
2021-08-30 20:03     ` Alan Mackenzie
2021-08-31 11:53       ` Eli Zaretskii

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.gnu.org/software/emacs/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YLyzi1ABx84M62QJ@ACM \
    --to=acm@muc.de \
    --cc=dancol@dancol.org \
    --cc=emacs-devel@gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).