From: "Harald Jörg" <haj@posteo.de>
To: Stefan Kangas <stefankangas@gmail.com>, 16368@debbugs.gnu.org
Subject: bug#16368: [PATCH] cperl-mode: don't freeze over a cool regexp
Date: Thu, 3 Sep 2020 22:27:12 +0200 [thread overview]
Message-ID: <cd801d41-5cb8-e620-e997-11142e7fbbb2@posteo.de> (raw)
In-Reply-To: <CADwFkmmsYYPZgibTWSPJVRLkvce3tdK-HO42BWiBDZMqc6OkrQ@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 1874 bytes --]
On 9/3/20 11:58 AM, Stefan Kangas wrote:
> Harald Jörg <haj@posteo.de> writes:
>
>> I'd say this is desired behavior.
>
> OK, thanks. Your explanation sounds good to me.
It wasn't quite accurate, though. My explanation assumed that the
regex as a whole wasn't terminated, but in fact it was. In fact, the
message comes from the fact that (?{...}) introduces a block of code
into the regexp. So, by removing the colon from (?:{...}), the
semantics changed from "just another shy group" to "code", and for
code cperl-mode applies stricter rules than for the contents of a
capture group.
I'd still say the message is ok.
>> I can only guess that the first part of the message (which starts with
>> "cperl-forward-group-in-re") was added out of frustration: The bug
>> prevented the second part of the message (without
>> "cperl-forward-group-in-re") from ever appearing. Only this wasn't
>> fatal unless... there was this closing brace two characters before.
>> I'll check that, and prepare an updated patch if that's true.
>
> Sounds good.
...And done. Now you get only one message, without the unnecessary
"cperl-forward-group-in-re" prefix.
>> No problem, I'll do so. I thought I was supposed to create the commit
>> messages with C-x 4 a, but probably I misunderstood and should have
>> post-processed that text in the first place.
>
> I always use C-x 4 a, and then delete the spacing to the left.
Ok, adapted. I have also used your recommendation for the commit
summary.
>> Hm. That should rather be _moving_ that line to the top?
>
> Ah, right. Yup, that sounds good.
When I did this, I stumbled over the purpose of Stefan Monniers change
to the tests - this has been taken to emacs-devel. For now, moving
the line to the top and skipping the test if called in a perl-mode
environment, should do the trick.
Patch, mark2, is attached!
--
Cheers,
haj
[-- Attachment #2: 0001-Fix-freeze-in-cperl-mode-when-editing-a-regexp.patch --]
[-- Type: text/x-patch, Size: 3363 bytes --]
From 2ae8d341de4cb9782241348b28e4f713c317925c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Harald=20J=C3=B6rg?= <haj@posteo.de>
Date: Thu, 3 Sep 2020 22:11:47 +0200
Subject: [PATCH] Fix freeze in cperl-mode when editing a regexp
* lisp/progmodes/cperl-mode.el (cperl-forward-group-in-re): Make
sure that an error is reported back to the caller (Bug#16368).
* test/lisp/progmodes/cperl-mode-tests.el (cperl-mode-test-bug-16368):
Tests for balanced (no error) and unbalanced (caught exception)
cases of `cperl-forward-group-in-re'.
---
lisp/progmodes/cperl-mode.el | 9 ++++-----
test/lisp/progmodes/cperl-mode-tests.el | 23 +++++++++++++++++++++++
2 files changed, 27 insertions(+), 5 deletions(-)
diff --git a/lisp/progmodes/cperl-mode.el b/lisp/progmodes/cperl-mode.el
index 44579cfd38..e2628c834c 100644
--- a/lisp/progmodes/cperl-mode.el
+++ b/lisp/progmodes/cperl-mode.el
@@ -3241,8 +3241,8 @@ cperl-forward-group-in-re
Works before syntax recognition is done."
;; Works *before* syntax recognition is done
(or st-l (setq st-l (list nil))) ; Avoid overwriting '()
- (let (st b reset-st)
- (condition-case b
+ (let (st result reset-st)
+ (condition-case err
(progn
(setq st (cperl-cached-syntax-table st-l))
(modify-syntax-entry ?\( "()" st)
@@ -3250,8 +3250,7 @@ cperl-forward-group-in-re
(setq reset-st (syntax-table))
(set-syntax-table st)
(forward-sexp 1))
- (error (message
- "cperl-forward-group-in-re: error %s" b)))
+ (error (setq result err)))
;; now restore the initial state
(if st
(progn
@@ -3259,7 +3258,7 @@ cperl-forward-group-in-re
(modify-syntax-entry ?\) "." st)))
(if reset-st
(set-syntax-table reset-st))
- b))
+ result))
(defvar font-lock-string-face)
diff --git a/test/lisp/progmodes/cperl-mode-tests.el b/test/lisp/progmodes/cperl-mode-tests.el
index be8b42d99a..e14ff98e3f 100644
--- a/test/lisp/progmodes/cperl-mode-tests.el
+++ b/test/lisp/progmodes/cperl-mode-tests.el
@@ -18,6 +18,8 @@
(defvar cperl-test-mode #'cperl-mode)
+(require 'cperl-mode)
+
(defun cperl-test-ppss (text regexp)
"Return the `syntax-ppss' of the first character matched by REGEXP in TEXT."
(interactive)
@@ -48,4 +50,25 @@ cperl-mode-test-bug-42168
(let ((code "{ $a- / $b } # /"))
(should (equal (nth 8 (cperl-test-ppss code "/")) 7))))
+(ert-deftest cperl-mode-test-bug-16368 ()
+ "Verify that `cperl-forward-group-in-re' doesn't hide errors."
+ (skip-unless (eq cperl-test-mode #'cperl-mode))
+ (let ((code "/(\\d{4})(?{2}/;") ; the regex from the bug report
+ (result))
+ (with-temp-buffer
+ (insert code)
+ (goto-char 9)
+ (setq result (cperl-forward-group-in-re))
+ (should (equal (car result) 'scan-error))
+ (should (equal (nth 1 result) "Unbalanced parentheses"))
+ (should (= (point) 9)))) ; point remains unchanged on error
+ (let ((code "/(\\d{4})(?{2})/;") ; here all parens are balanced
+ (result))
+ (with-temp-buffer
+ (insert code)
+ (goto-char 9)
+ (setq result (cperl-forward-group-in-re))
+ (should (equal result nil))
+ (should (= (point) 15))))) ; point has skipped the group
+
;;; cperl-mode-tests.el ends here
--
2.20.1
next prev parent reply other threads:[~2020-09-03 20:27 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-06 1:28 bug#16368: 24.3; freeze in cperl mode when editing a regexp Vincent Lefevre
2019-09-20 23:33 ` Stefan Kangas
2020-09-02 20:06 ` bug#16368: [PATCH] cperl-mode: don't freeze over a cool regexp Harald Jörg
2020-09-02 22:19 ` Stefan Kangas
2020-09-02 23:40 ` Harald Jörg
2020-09-03 9:58 ` Stefan Kangas
2020-09-03 20:27 ` Harald Jörg [this message]
2020-09-03 21:12 ` Stefan Kangas
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
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=cd801d41-5cb8-e620-e997-11142e7fbbb2@posteo.de \
--to=haj@posteo.de \
--cc=16368@debbugs.gnu.org \
--cc=stefankangas@gmail.com \
/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 external index
https://git.savannah.gnu.org/cgit/emacs.git
https://git.savannah.gnu.org/cgit/emacs/org-mode.git
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.