From: Alan Mackenzie <acm@muc.de>
To: Dmitry Gutov <dgutov@yandex.ru>
Cc: 22983@debbugs.gnu.org
Subject: bug#22983: syntax-ppss returns wrong result.
Date: Sat, 19 Mar 2016 12:27:59 +0000 [thread overview]
Message-ID: <20160319122759.GA2644@acm.fritz.box> (raw)
In-Reply-To: <44b4fa9e-ec8e-98a4-d8ad-e799fffa7959@yandex.ru>
Hello, Dmitry.
On Fri, Mar 18, 2016 at 02:49:34AM +0200, Dmitry Gutov wrote:
> On 03/11/2016 05:15 PM, Alan Mackenzie wrote:
> This patch should make ppss-0 and ppss-1 match:
OK, no bad thing!
But seeing that the function is a new function (its specification has
changed), it will need new test cases, fresh new attempts to break it.
> diff --git a/lisp/emacs-lisp/syntax.el b/lisp/emacs-lisp/syntax.el
> index e20a210..c1b9d84 100644
> --- a/lisp/emacs-lisp/syntax.el
> +++ b/lisp/emacs-lisp/syntax.el
> @@ -371,6 +371,11 @@ syntax-ppss-max-span
> We try to make sure that cache entries are at least this far apart
> from each other, to avoid keeping too much useless info.")
> +(defvar syntax-ppss-dont-widen nil
> + "If non-nil, `syntax-ppss' will work on the non-widened buffer.
> +The code that uses this should create local bindings for
> +`syntax-ppss-cache' and `syntax-ppss-last' too.")
> +
I'm against this bit. If syntax-ppss-dont-widen is non-nil, the buffer
is narrowed, and the local cache variables are correctly bound and
filled, then something at a low level is going to widen the buffer (and
call back_comment) without knowing to restore the global bindings for
those cache variables. This could easily give the wrong result and
corrupt the locally bound cache.
I think the only sensible functionality for syntax-ppss is to be
equivalent to (parse-partial-sexp 1 pos). Then everybody knows where
they stand. Those pieces of code which actually need a ppss cache with
origin other than 1 could then use a more appropriate specialized
function whose cache wouldn't get mixed up with syntax-ppss's. (It
could share a lot of code with syntax-ppss).
> (defvar syntax-begin-function nil
> "Function to move back outside of any comment/string/paren.
> This function should move the cursor back to some syntactically safe
> @@ -423,12 +428,21 @@ syntax-ppss
> in the returned list (counting from 0) cannot be relied upon.
> Point is at POS when this function returns.
> +IF `syntax-ppss-dont-widen' is nil, the buffer is temporarily
> +widened.
> +
> It is necessary to call `syntax-ppss-flush-cache' explicitly if
> this function is called while `before-change-functions' is
> temporarily let-bound, or if the buffer is modified without
> running the hook."
> ;; Default values.
> (unless pos (setq pos (point)))
> + (save-restriction
> + (unless syntax-ppss-dont-widen
> + (widen))
> + (syntax-pps--at pos)))
> +
> +(defun syntax-ppss--at (pos)
> (syntax-propertize pos)
> ;;
> (let ((old-ppss (cdr syntax-ppss-last))
--
Alan Mackenzie (Nuremberg, Germany).
next prev parent reply other threads:[~2016-03-19 12:27 UTC|newest]
Thread overview: 155+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-11 15:15 bug#22983: syntax-ppss returns wrong result Alan Mackenzie
2016-03-11 20:31 ` Dmitry Gutov
2016-03-11 21:24 ` Alan Mackenzie
2016-03-11 21:35 ` Dmitry Gutov
2016-03-11 22:15 ` Alan Mackenzie
2016-03-11 22:38 ` Dmitry Gutov
2016-03-13 17:37 ` Stefan Monnier
2016-03-13 18:57 ` Alan Mackenzie
2016-03-14 0:47 ` Dmitry Gutov
2016-03-14 1:04 ` Drew Adams
2016-04-03 22:55 ` John Wiegley
2016-03-14 1:49 ` Stefan Monnier
2016-03-14 15:16 ` Syntax tables for multiple modes [was: bug#22983: syntax-ppss returns wrong result.] Alan Mackenzie
2016-03-14 17:34 ` Andreas Röhler
2016-03-14 20:06 ` Dmitry Gutov
2016-03-19 22:51 ` Vitalie Spinu
2016-03-20 2:19 ` Dmitry Gutov
2016-03-20 12:15 ` Vitalie Spinu
2016-03-20 15:58 ` Dmitry Gutov
2016-03-21 1:05 ` Vitalie Spinu
2016-03-21 3:11 ` Stefan Monnier
2016-03-21 5:05 ` Vitalie Spinu
2016-03-21 7:13 ` Andreas Röhler
2016-03-21 12:26 ` Stefan Monnier
2016-03-21 14:13 ` Vitalie Spinu
2016-03-21 14:43 ` Stefan Monnier
2016-03-21 16:42 ` Vitalie Spinu
2016-03-21 18:31 ` Stefan Monnier
2016-03-21 19:16 ` Vitalie Spinu
2016-03-21 20:47 ` Stefan Monnier
2016-03-21 20:33 ` Alan Mackenzie
2016-03-21 20:49 ` Stefan Monnier
2016-03-21 21:03 ` Drew Adams
2016-03-21 21:12 ` Dmitry Gutov
2016-03-21 16:45 ` Vitalie Spinu
2016-03-21 22:55 ` Dmitry Gutov
2016-03-22 14:51 ` Stefan Monnier
2016-03-22 18:17 ` Vitalie Spinu
2016-03-23 1:18 ` Dmitry Gutov
2016-03-23 13:18 ` Stefan Monnier
2016-03-22 18:26 ` Vitalie Spinu
2016-03-23 2:07 ` Stefan Monnier
2016-03-23 10:56 ` Vitalie Spinu
2016-03-23 11:41 ` Stefan Monnier
2016-03-23 12:39 ` Vitalie Spinu
2016-03-23 13:23 ` Stefan Monnier
2016-03-23 15:28 ` Dmitry Gutov
2016-03-23 21:51 ` Vitalie Spinu
2016-03-24 7:30 ` Andreas Röhler
2016-03-21 11:56 ` Dmitry Gutov
2016-03-21 5:08 ` [Patch] hard-widen-limits [was Re: Syntax tables for multiple modes [was: bug#22983: syntax-ppss returns wrong result.]] Vitalie Spinu
2016-03-21 12:39 ` Stefan Monnier
2016-03-21 12:54 ` Vitalie Spinu
2016-03-21 14:07 ` Stefan Monnier
2016-03-21 14:14 ` Vitalie Spinu
2016-03-21 14:04 ` Stefan Monnier
2016-03-21 14:33 ` Vitalie Spinu
2016-03-21 14:54 ` Stefan Monnier
2016-03-21 17:16 ` Vitalie Spinu
2016-03-21 18:36 ` Stefan Monnier
2016-03-21 19:18 ` Vitalie Spinu
2016-03-22 3:17 ` Vitalie Spinu
2016-03-22 9:57 ` Vitalie Spinu
2016-03-22 10:05 ` Vitalie Spinu
2016-03-22 11:57 ` Stefan Monnier
2016-03-22 16:28 ` Vitalie Spinu
2016-03-22 16:44 ` Stefan Monnier
2016-03-22 19:36 ` Vitalie Spinu
2016-03-23 2:22 ` Stefan Monnier
2016-03-23 11:41 ` Vitalie Spinu
2016-03-23 12:34 ` Stefan Monnier
2016-03-23 12:41 ` Vitalie Spinu
2016-03-29 21:43 ` Vitalie Spinu
2016-04-22 14:34 ` Dmitry Gutov
2016-04-24 7:22 ` Vitalie Spinu
2016-04-24 7:28 ` Achim Gratz
2016-04-24 11:33 ` Vitalie Spinu
2016-04-24 13:20 ` Andreas Schwab
2016-04-24 16:11 ` Vitalie Spinu
2016-04-24 16:19 ` Andreas Schwab
2016-04-24 16:41 ` Vitalie Spinu
2016-04-24 16:48 ` Andreas Schwab
2016-04-24 18:01 ` Vitalie Spinu
2016-04-24 19:05 ` Andreas Schwab
2016-04-28 13:29 ` Vitalie Spinu
2016-04-30 14:06 ` Stefan Monnier
2016-03-22 20:08 ` Richard Stallman
2016-03-22 22:45 ` Vitalie Spinu
2016-03-21 11:47 ` Syntax tables for multiple modes [was: bug#22983: syntax-ppss returns wrong result.] Dmitry Gutov
2016-03-21 12:40 ` Vitalie Spinu
2016-03-21 13:07 ` Dmitry Gutov
2016-03-21 14:20 ` Vitalie Spinu
2016-03-21 14:29 ` Dmitry Gutov
2016-03-21 14:42 ` Vitalie Spinu
2016-03-21 14:56 ` Dmitry Gutov
2016-03-21 16:52 ` Vitalie Spinu
2016-03-21 21:30 ` Dmitry Gutov
2016-04-03 23:34 ` John Wiegley
2016-03-21 14:02 ` Stefan Monnier
2016-03-21 14:31 ` Vitalie Spinu
2016-03-21 15:06 ` Stefan Monnier
2016-03-21 17:15 ` Andreas Röhler
2016-03-13 17:32 ` bug#22983: syntax-ppss returns wrong result Stefan Monnier
2016-03-13 18:52 ` Andreas Röhler
2016-03-13 18:56 ` Dmitry Gutov
2016-03-18 0:49 ` Dmitry Gutov
2016-03-19 12:27 ` Alan Mackenzie [this message]
2016-03-19 18:47 ` Dmitry Gutov
2016-03-27 0:51 ` John Wiegley
2016-03-27 1:14 ` Dmitry Gutov
2016-04-03 22:58 ` John Wiegley
2016-04-03 23:15 ` Dmitry Gutov
2017-09-02 13:12 ` Eli Zaretskii
2017-09-02 17:40 ` Alan Mackenzie
2017-09-02 17:53 ` Eli Zaretskii
2017-09-03 20:44 ` John Wiegley
2017-09-04 23:34 ` Dmitry Gutov
2017-09-05 6:57 ` Andreas Röhler
2017-09-05 12:28 ` John Wiegley
2017-09-07 20:45 ` Alan Mackenzie
2017-09-08 16:04 ` Andreas Röhler
2017-09-10 18:26 ` Alan Mackenzie
2017-09-09 9:44 ` Dmitry Gutov
2017-09-09 10:20 ` Alan Mackenzie
2017-09-09 12:18 ` Dmitry Gutov
2017-09-10 11:42 ` Alan Mackenzie
2017-09-10 11:36 ` bug#22983: [ Patch ] " Alan Mackenzie
2017-09-10 22:53 ` Stefan Monnier
2017-09-10 23:36 ` Dmitry Gutov
2017-09-11 11:10 ` Stefan Monnier
2017-09-12 0:11 ` Dmitry Gutov
2017-09-12 22:12 ` Richard Stallman
2017-09-11 19:42 ` Alan Mackenzie
2017-09-11 20:20 ` Stefan Monnier
2017-09-11 0:11 ` Dmitry Gutov
2017-09-11 20:12 ` Alan Mackenzie
2017-09-12 0:24 ` Dmitry Gutov
2017-09-17 10:29 ` Alan Mackenzie
2017-09-17 23:43 ` Dmitry Gutov
2017-09-18 19:08 ` Alan Mackenzie
2017-09-19 0:02 ` Dmitry Gutov
2017-09-19 20:47 ` Alan Mackenzie
2017-09-22 14:09 ` Dmitry Gutov
2017-09-24 11:26 ` Alan Mackenzie
2017-09-25 23:53 ` Dmitry Gutov
2017-10-01 16:36 ` Alan Mackenzie
2017-10-04 20:07 ` Johan Bockgård
2017-09-17 11:12 ` Philipp Stephani
2017-09-19 20:50 ` Alan Mackenzie
2017-09-07 17:56 ` Alan Mackenzie
2017-09-07 20:36 ` Dmitry Gutov
2016-03-19 23:16 ` Vitalie Spinu
2016-03-19 23:00 ` Vitalie Spinu
2016-03-19 23:20 ` Dmitry Gutov
[not found] ` <mailman.7307.1457709188.843.bug-gnu-emacs@gnu.org>
2017-10-01 16:31 ` Alan Mackenzie
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