unofficial mirror of bug-gnu-emacs@gnu.org 
 help / color / mirror / code / Atom feed
From: defun.foo--- via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
To: 56643@debbugs.gnu.org
Subject: bug#56643: 29.0.50; Help-mode bookmarks not loading with native compilation
Date: Tue, 19 Jul 2022 13:45:19 +0000	[thread overview]
Message-ID: <mwm19QUBOCK9jDlMUc4jtyHFCGIUduFARvm89uVMQ-9HNe5SpaZzzjtHIa6XbNBcD2NUL7sqmr-TL71gB0ss4cuDhCMnzxJ-b-SaIHYafoE=@proton.me> (raw)

Overview:

With native compilation enabled, adding a bookmark in a help buffer seems to work normally for the duration of the Emacs session, but when Emacs is restarted an "Invalid read syntax: '#'" error is thrown and the entire bookmark list fails to load. This appears to be caused by a compiled lambda being serialized to the bookmark file in a way that is unreadable to the reader.

Emacs version:

29.0.5, compiled from latest master branch on 7-18-2022, and started with emacs -Q for both scenarios below.

Steps to reproduce:

1. Ensure that native compilation is enabled by running M-x native-comp-available-p
2. Run M-x describe-function {{any-function}} and move to the resulting *Help* buffer
3. Create a bookmark with C-x r m
4. Without quitting Emacs, kill the *Help* buffer, then run C-x r b to jump back to the bookmark (this works as expected)
5. Quit Emacs (C-x C-c), and restart
6. Attempt to jump to the same bookmark again (running C-x r b), and observe that the bookmark list fails to load and throws an "Invalid read syntax: '#'" error

Here is an example of a help bookmark as it was serialized to the bookmarks file (note the "help-fn" value):

("native-comp-bookmark"
 (position . 1)
 (last-modified 25301 49750 590832 312000)
 (help-fn . #<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_9>)
 (help-args switch-to-buffer "*scratch*")
 (position . 1)
 (handler . help-bookmark-jump))

For comparison, I compiled Emacs without the native compilation flag (and verified that native-comp-available-p returned nil), and went through the same steps above, creating a new bookmark. Jumping back to the bookmark after restarting works as expected, and here is an example of that bookmark serialized without native comp:

("vanilla-bookmark"
 (position . 1)
 (last-modified 25301 49238 861856 736000)
 (help-fn .
          #[514 "\301\x01!\205\a\0\211\x18\302\x02!)\207"
                [describe-function-orig-buffer buffer-live-p describe-function]
                4 "\n\n(fn FUNCTION BUFFER)"])
 (help-args switch-to-buffer "*scratch*")
 (position . 1)
 (handler . help-bookmark-jump))

I did find an older similar bug (#24573 https://lists.gnu.org/archive/html/bug-gnu-emacs/2016-09/msg00971.html) which was causing the same error due to a buffer object being serialized. This was fixed by saving just the buffer name, but I'm not sure there's any comparable way to save a reference to a compiled lambda. Any advice would be much appreciated though!





             reply	other threads:[~2022-07-19 13:45 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-19 13:45 defun.foo--- via Bug reports for GNU Emacs, the Swiss army knife of text editors [this message]
2022-07-19 16:49 ` bug#56643: 29.0.50; Help-mode bookmarks not loading with native compilation Eli Zaretskii
2022-07-19 22:22   ` defun.foo--- via Bug reports for GNU Emacs, the Swiss army knife of text editors
2022-07-20  9:51     ` Andrea Corallo
2022-07-20 11:21     ` Andrea Corallo
2022-07-20 11:45       ` Eli Zaretskii
2022-07-20 18:31         ` Andrea Corallo
2022-07-20 19:16           ` Eli Zaretskii
2022-07-20 22:47             ` Michael Heerdegen
2022-07-21  5:13               ` Eli Zaretskii
2022-07-21 10:01                 ` defun.foo--- via Bug reports for GNU Emacs, the Swiss army knife of text editors
2022-07-21 12:33                   ` Eli Zaretskii
2022-07-22 13:40                     ` Eli Zaretskii
2022-07-22 13:41                     ` Andrea Corallo
2022-07-22 14:40                       ` Eli Zaretskii
2022-07-23  9:57                         ` 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='mwm19QUBOCK9jDlMUc4jtyHFCGIUduFARvm89uVMQ-9HNe5SpaZzzjtHIa6XbNBcD2NUL7sqmr-TL71gB0ss4cuDhCMnzxJ-b-SaIHYafoE=@proton.me' \
    --to=bug-gnu-emacs@gnu.org \
    --cc=56643@debbugs.gnu.org \
    --cc=defun.foo@proton.me \
    /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).