GNU bug report logs - #51380
29.0.50; The annotated example of a complete working Flymake backend leaves process buffers around

Previous Next

To add a comment to this bug, you must first unarchive it, by sending
a message to control AT debbugs.gnu.org, with unarchive 51380 in the body.
You can then email your comments to 51380 AT debbugs.gnu.org in the normal way.

Toggle the display of automated, internal messages from the tracker.

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

From: Rudolf Adamkovič <salutis <at> me.com>
To: bug-gnu-emacs <at> gnu.org
Subject: 29.0.50; The annotated example of a complete working Flymake
 backend leaves process buffers around
Date: Sun, 24 Oct 2021 22:01:38 +0200

I noticed that the "annotated example of a complete working Flymake backend" at

<https://www.gnu.org/software/emacs/manual/html_mono/flymake.html#Backend-functions>

leaves zombie buffers around. I traced the problem down to

┌────
│ (when (eq 'exit (process-status proc)) …
└────

The backend kills the process buffer on `'exit' but not on `'signal', which happens when Flymake kills an obsolete in-progress check. I fixed the problem locally by checking for both `(or (eq status 'exit) (eq status 'signal)'. Below, I include a macro that includes the fix.

┌────
│ (defmacro my-define-flymake-backend (name cmd regexp warning-p)
│   "Define a new Flymake backend named NAME.
│ 
│ CMD takes a buffer file name and returns a system command
│ to run to check the buffer. REGEXP matches the output of the system
│ command in three capture groups: (1) line, (2) column, and (3)
│ message. WARNING-P takes the message matched by REGEXP and decides if
│ the issue represents a warning or an error.
│ 
│ The macro defines a function called NAME representing the Flymake
│ backend and a variable called NAME that stores the current process."
│   `(defun ,name (report-fn &rest _args)
│      (defvar-local ,name nil)
│      (when (process-live-p ,name) (kill-process ,name))
│      (let ((src (current-buffer)))
│        (save-restriction
│          (widen)
│          (setq
│           ,name
│           (make-process
│            :name (symbol-name ',name)
│            :noquery t
│            :connection-type 'pipe
│            :buffer (generate-new-buffer
│                     (concat "*" (symbol-name ',name) "*"))
│            :command (with-current-buffer src
│                       (funcall ,cmd buffer-file-name))
│            :sentinel
│            (lambda (proc _event)
│              (let ((status (process-status proc)))
│                (when (or (eq status 'exit)
│                          (eq status 'signal))
│                  (unwind-protect
│                      (when (and (with-current-buffer src (eq proc ,name))
│                                 (eq status 'exit))
│                        (with-current-buffer (process-buffer proc)
│                          (goto-char (point-min))
│                          (cl-loop
│                           while (search-forward-regexp ,regexp nil t)
│                           for msg = (match-string 3)
│                           for line = (string-to-number (match-string 1))
│                           for col = (string-to-number (match-string 2))
│                           for (beg . end) = (flymake-diag-region src line col)
│                           for type = (if (funcall ,warning-p msg) :warning :error)
│                           collect (flymake-make-diagnostic src beg end type msg)
│                           into diags
│                           finally (funcall report-fn diags))))
│                    (kill-buffer (process-buffer proc))))))))
│          (process-send-region ,name (point-min) (point-max))
│          (process-send-eof ,name)))))
└────

For completeness, I call the macro above as follows:

┌────
│ (my-define-flymake-backend
│  my-flymake-vale
│  (lambda (source) (list "vale" "--output" "line" "--ext" ".md", "--no-wrap"))
│  "^stdin.md:\\([0-9]+\\):\\([0-9]+\\):\\(.*\\)$"
│  (lambda (msg) t))
└────

Rudy


In GNU Emacs 29.0.50 (build 6, x86_64-apple-darwin20.6.0, NS appkit-2022.60 Version 11.5.1 (Build 20G80))
 of 2021-10-24 built on Workstation.local
Repository revision: aea4af5119fdf130f1df7190478a23c6777f92a2
Repository branch: master
Windowing system distributor 'Apple', version 10.3.2022
System Description:  macOS 11.5.1

Configured using:
 'configure --with-json
 PKG_CONFIG_PATH=/usr/local/Cellar/zlib/1.2.11/lib/pkgconfig:/usr/local/lib/pkgconfig:/opt/X11/lib/pkgconfig'

Configured features:
ACL DBUS GIF GLIB GMP GNUTLS JPEG JSON LCMS2 LIBXML2 MODULES NOTIFY
KQUEUE NS PDUMPER PNG RSVG THREADS TIFF TOOLKIT_SCROLL_BARS WEBP XIM
ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Text

Minor modes in effect:
  TeX-PDF-mode: t
  shell-dirtrack-mode: t
  flymake-mode: t
  which-key-mode: t
  corfu-global-mode: t
  corfu-mode: t
  vertico-mode: t
  marginalia-mode: t
  global-diff-hl-mode: t
  yas-global-mode: t
  yas-minor-mode: t
  global-hl-todo-mode: t
  hl-todo-mode: t
  savehist-mode: t
  global-subword-mode: t
  subword-mode: t
  save-place-mode: t
  global-auto-revert-mode: t
  delete-selection-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  size-indication-mode: t
  column-number-mode: t
  line-number-mode: t
  global-visual-line-mode: t
  visual-line-mode: t
  transient-mark-mode: t

Load-path shadows:
/Users/salutis/.emacs.d/elpa/transient-20211023.2151/transient hides /Users/salutis/src/emacs/nextstep/Emacs.app/Contents/Resources/lisp/transient

Features:
(shadow sort bbdb-message fortune mail-extr emacsbug sendmail ox-md
ox-odt rng-loc rng-uri rng-parse rng-match rng-dt rng-util rng-pttrn
nxml-parse nxml-ns nxml-enc xmltok nxml-util ox-latex ox-icalendar
org-agenda org-refile ox-html table ox-ascii ox-publish ox bug-reference
helpful imenu trace edebug backtrace info-look help-fns radix-tree
elisp-refs vc-mtn vc-hg vc-bzr vc-src vc-sccs vc-svn vc-cvs vc-rcs
preview tex-buf font-latex latex edmacro latex-flymake tex-ispell
tex-style tex crm texmathp tex-mode shell flymake-proc flymake project
warnings org-indent image-file image-converter disp-table char-fold
cursor-sensor bbdb bbdb-site timezone modus-vivendi-theme
modus-operandi-theme modus-themes which-key corfu orderless
consult-vertico vertico marginalia consult recentf tree-widget kmacro
pdf-loader diff-hl log-view pcvs-util vc-dir ewoc vc diminish yasnippet
hl-todo finder-inf org-clock oc-csl citeproc citeproc-itemgetters
citeproc-biblatex citeproc-bibtex parsebib citeproc-cite
citeproc-subbibs citeproc-sort citeproc-name citeproc-formatters
citeproc-number rst compile citeproc-proc citeproc-disamb
citeproc-itemdata citeproc-generic-elements citeproc-macro
citeproc-choose citeproc-date citeproc-context citeproc-prange
citeproc-style citeproc-locale citeproc-term f citeproc-rt citeproc-lib
citeproc-s s let-alist queue dash savehist ls-lisp cap-words superword
subword saveplace autorevert filenotify delsel elfeed-link elfeed-show
elfeed-search elfeed-csv elfeed elfeed-curl elfeed-log xml-query
bookmark pp elfeed-db elfeed-lib vc-git diff-mode vc-dispatcher
org-element avl-tree generator ol-eww eww xdg url-queue thingatpt mm-url
ol-rmail ol-mhe ol-irc ol-info ol-gnus nnselect gnus-search eieio-opt
speedbar ezimage dframe gnus-art mm-uu mml2015 mm-view mml-smime smime
dig gnus-sum shr kinsoku svg dom gnus-group gnus-undo gnus-start
gnus-dbus dbus xml gnus-cloud nnimap nnmail mail-source utf7 netrc nnoo
parse-time gnus-spec gnus-int gnus-range message rmc puny rfc822 mml
mml-sec epa derived epg rfc6068 epg-config mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader gnus-win gnus
nnheader gnus-util rmail rmail-loaddefs rfc2047 rfc2045 ietf-drums
text-property-search mail-utils mm-util mail-prsvr wid-edit ol-docview
doc-view jka-compr image-mode exif dired dired-loaddefs ol-bibtex
ol-bbdb ol-w3m ol-doi org-link-doi cl-extra help-mode org ob ob-tangle
ob-ref ob-lob ob-table ob-exp org-macro org-footnote org-src ob-comint
org-pcomplete pcomplete comint ansi-color ring org-list org-faces
org-entities noutline outline easy-mmode org-version ob-emacs-lisp
ob-core ob-eval org-table oc-basic bibtex iso8601 time-date ol rx
org-keys oc org-compat advice org-macs org-loaddefs format-spec
find-func cal-menu calendar cal-loaddefs tex-site info package
browse-url url url-proxy url-privacy url-expand url-methods url-history
url-cookie url-domsuf url-util mailcap url-handlers url-parse
auth-source cl-seq eieio eieio-core cl-macs eieio-loaddefs
password-cache json map url-vars seq gv subr-x byte-opt bytecomp
byte-compile cconv cl-loaddefs cl-lib iso-transl tooltip eldoc paren
electric uniquify ediff-hook vc-hooks lisp-float-type elisp-mode mwheel
term/ns-win ns-win ucs-normalize mule-util term/common-win tool-bar dnd
fontset image regexp-opt fringe tabulated-list replace newcomment
text-mode lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow
isearch easymenu timer select scroll-bar mouse jit-lock font-lock syntax
font-core term/tty-colors frame minibuffer cl-generic cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese composite emoji-zwj charscript charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray
cl-preloaded nadvice button loaddefs faces cus-face macroexp files
window text-properties overlay sha1 md5 base64 format env code-pages
mule custom widget hashtable-print-readable backquote threads dbusbind
kqueue cocoa ns lcms2 multi-tty make-network-process emacs)

Memory information:
((conses 16 887550 54338)
 (symbols 48 45003 4)
 (strings 32 241995 11585)
 (string-bytes 1 6618139)
 (vectors 16 86621)
 (vector-slots 8 1813636 54587)
 (floats 8 435 550)
 (intervals 56 24349 524)
 (buffers 992 23))

-- 
"I love deadlines. I love the whooshing noise they make as they go by." -- Douglas Adams, The Salmon of Doubt

Rudolf Adamkovič <salutis <at> me.com>
Studenohorská 25
84103 Bratislava
Slovakia

[he/him]

Message #8 received at 51380 <at> debbugs.gnu.org (full text, mbox):

From: Lars Ingebrigtsen <larsi <at> gnus.org>
To: Rudolf Adamkovič <salutis <at> me.com>
Cc: 51380 <at> debbugs.gnu.org
Subject: Re: bug#51380: 29.0.50; The annotated example of a complete working
 Flymake backend leaves process buffers around
Date: Mon, 25 Oct 2021 01:26:01 +0200

Rudolf Adamkovič <salutis <at> me.com> writes:

> leaves zombie buffers around. I traced the problem down to
>
> ┌────
> │ (when (eq 'exit (process-status proc)) …
> └────
>
> The backend kills the process buffer on `'exit' but not on `'signal', which happens when Flymake kills an obsolete in-progress check. I fixed the problem locally by checking for both `(or (eq status 'exit) (eq status 'signal)'. 

Yup.  I've now fixed this in emacs-28 (which will be merged into
master in a few days).

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Message #13 received at 51380 <at> debbugs.gnu.org (full text, mbox):

From: Rudolf Adamkovič <salutis <at> me.com>
To: Lars Ingebrigtsen <larsi <at> gnus.org>
Cc: Stefan Kangas <stefankangas <at> gmail.com>, 51380 <at> debbugs.gnu.org
Subject: Re: bug#51380: 29.0.50; The annotated example of a complete working
 Flymake backend leaves process buffers around
Date: Wed, 27 Oct 2021 14:25:06 +0200

Lars Ingebrigtsen <larsi <at> gnus.org> writes:

> Yup.  I've now fixed this in emacs-28 …

Thank you!

P.S. CC'ing Stefan per his request (via emacs-devel).

-- 
"Logic is a science of the necessary laws of thought, without which no employment of the understanding and the reason takes place." -- Immanuel Kant, 1785

Rudolf Adamkovič <salutis <at> me.com>
Studenohorská 25
84103 Bratislava
Slovakia

[he/him]

Message #16 received at 51380 <at> debbugs.gnu.org (full text, mbox):

From: Rudolf Adamkovič <salutis <at> me.com>
To: 51380 <at> debbugs.gnu.org
Cc: Lars Ingebrigtsen <larsi <at> gnus.org>, Stefan Kangas <stefankangas <at> gmail.com>,
 joaotavora <at> gmail.com
Subject: Re: bug#51380: 29.0.50; The annotated example of a complete working
 Flymake backend leaves process buffers around
Date: Wed, 27 Oct 2021 15:19:30 +0200

Lars Ingebrigtsen <larsi <at> gnus.org> writes:

> Yup.  I've now fixed this in emacs-28 …

Note, I opened bug#51437 for yet another problem with the Flymake backend example.

> P.S. CC'ing Stefan per his request (via emacs-devel).

I CC'd a wrong person. *facepalm* My apologies to Stefan and CC goes to João!

Rudy

-- 
"Programming reliably --- must be an activity of an undeniably mathematical nature […] You see, mathematics is about thinking, and doing mathematics is always trying to think as well as possible." -- Edsger W. Dijkstra (1981)

Rudolf Adamkovič <salutis <at> me.com>
Studenohorská 25
84103 Bratislava
Slovakia

[he/him]

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.