bug#71012: 30.0.50; tree-sitter crash

bug#71012: 30.0.50; tree-sitter crash

[Helmut Eller]

[-- Attachment #1: Type: text/plain, Size: 124 bytes --]

The code in the attached file tries to parse src/lisp.h but crashes
while printing the result:  emacs --batch -l ts-bug.el


[-- Attachment #2: ts-bug.el --]
[-- Type: application/emacs-lisp, Size: 145 bytes --]

[-- Attachment #3: Type: text/plain, Size: 2183 bytes --]



Program received signal SIGSEGV, Segmentation fault.
0x000055555575c33a in buf_bytepos_to_charpos (b=0x555556074c60, bytepos=1)
    at marker.c:343
343       eassert (bytepos >= BUF_Z_BYTE (b)
(gdb) ba 10
#0  0x000055555575c33a in buf_bytepos_to_charpos (b=0x555556074c60, bytepos=1)
    at marker.c:343
#1  0x0000555555853509 in Ftreesit_node_start
    (node=node@entry=XIL(0x55555605b225)) at treesit.c:1927
#2  0x00005555557f3f8a in print_vectorlike_unreadable
    (obj=XIL(0x55555605b225), printcharfun=XIL(0), escapeflag=<optimized out>, buf=0x7fffffff7ef0 "dd\aVUU") at print.c:2051
#3  0x00005555557f1b85 in print_object
    (obj=<optimized out>, printcharfun=<optimized out>, escapeflag=false)
    at print.c:2642
#4  0x00005555557f2cf0 in Fprin1_to_string
    (object=object@entry=XIL(0x55555605b225), noescape=XIL(0x30), overrides=overrides@entry=XIL(0)) at print.c:814
#5  0x00005555557b7c30 in styled_format
    (nargs=2, args=args@entry=0x7fffffffda30, message=message@entry=true)
    at editfns.c:3635
#6  0x00005555557b933f in Fformat_message
    (args=0x7fffffffda30, nargs=<optimized out>) at editfns.c:3388
#7  Fmessage (args=0x7fffffffda30, nargs=<optimized out>) at editfns.c:3185
#8  Fmessage (nargs=<optimized out>, args=0x7fffffffda30) at editfns.c:3154
#9  0x00005555557c6b75 in eval_sub (form=<optimized out>)
    at /scratch/emacs/emacs-git/src/lisp.h:2243
(More stack frames follow...)



In GNU Emacs 30.0.50 (build 6, x86_64-pc-linux-gnu, GTK+ Version
 3.24.38, cairo version 1.16.0) of 2024-05-17 built on caladan
Repository revision: 6ca3a60db3427bc6aef08144c1524920ff3d9c4d
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101007
System Description: Debian GNU/Linux 12 (bookworm)

Configured using:
 'configure --enable-checking --without-native-compiler
 --with-xpm=ifavailable --with-gif=ifavailable
 --with-native-compilation=no --with-tree-sitter'

Configured features:
CAIRO DBUS FREETYPE GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG LIBSELINUX
LIBSYSTEMD LIBXML2 MODULES NOTIFY INOTIFY PDUMPER PNG SECCOMP SOUND
SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS TREE_SITTER WEBP X11 XDBE XIM
XINPUT2 GTK3 ZLIB

bug#71012: 30.0.50; tree-sitter crash

[Eli Zaretskii]

> From: Helmut Eller <eller.helmut@gmail.com>
> Date: Fri, 17 May 2024 15:39:27 +0200
> 
> The code in the attached file tries to parse src/lisp.h but crashes
> while printing the result:  emacs --batch -l ts-bug.el

Yuan, can you help, please?

Btw, why do you use treesit-parse-string?  The Emacs integration with
tree-sitter can parse a buffer without making a string from its
contents.

bug#71012: 30.0.50; tree-sitter crash

[Helmut Eller]

> Btw, why do you use treesit-parse-string?  The Emacs integration with
> tree-sitter can parse a buffer without making a string from its
> contents.

It's the first time that I use treesit.  I just tried a few things.

bug#71012: 30.0.50; tree-sitter crash

[Eli Zaretskii]

> From: Helmut Eller <eller.helmut@gmail.com>
> Cc: Yuan Fu <casouri@gmail.com>,  71012@debbugs.gnu.org
> Date: Fri, 17 May 2024 17:34:04 +0200
> 
> > Btw, why do you use treesit-parse-string?  The Emacs integration with
> > tree-sitter can parse a buffer without making a string from its
> > contents.
> 
> It's the first time that I use treesit.  I just tried a few things.

There's a chapter about it in the ELisp manual (the node "Parsing
Program Source"), in case you haven't read it.

bug#71012: 30.0.50; tree-sitter crash

[Yuan Fu]

> On May 17, 2024, at 8:29 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> From: Helmut Eller <eller.helmut@gmail.com>
>> Date: Fri, 17 May 2024 15:39:27 +0200
>> 
>> The code in the attached file tries to parse src/lisp.h but crashes
>> while printing the result:  emacs --batch -l ts-bug.el
> 
> Yuan, can you help, please?
> 
> Btw, why do you use treesit-parse-string?  The Emacs integration with
> tree-sitter can parse a buffer without making a string from its
> contents.

Yep, I’ll look into it.

Yuan

bug#71012: 30.0.50; tree-sitter crash

[Yuan Fu]

> On May 17, 2024, at 11:07 PM, Yuan Fu <casouri@gmail.com> wrote:
> 
> 
> 
>> On May 17, 2024, at 8:29 AM, Eli Zaretskii <eliz@gnu.org> wrote:
>> 
>>> From: Helmut Eller <eller.helmut@gmail.com>
>>> Date: Fri, 17 May 2024 15:39:27 +0200
>>> 
>>> The code in the attached file tries to parse src/lisp.h but crashes
>>> while printing the result:  emacs --batch -l ts-bug.el
>> 
>> Yuan, can you help, please?
>> 
>> Btw, why do you use treesit-parse-string?  The Emacs integration with
>> tree-sitter can parse a buffer without making a string from its
>> contents.
> 
> Yep, I’ll look into it.
> 
> Yuan

Just an update, I didn’t forget about this. If I didn’t reply back today, I will in a few days :-)

Yuan

bug#71012: 30.0.50; tree-sitter crash

[Yuan Fu]

> On May 27, 2024, at 3:10 PM, Yuan Fu <casouri@gmail.com> wrote:
> 
> 
> 
>> On May 17, 2024, at 11:07 PM, Yuan Fu <casouri@gmail.com> wrote:
>> 
>> 
>> 
>>> On May 17, 2024, at 8:29 AM, Eli Zaretskii <eliz@gnu.org> wrote:
>>> 
>>>> From: Helmut Eller <eller.helmut@gmail.com>
>>>> Date: Fri, 17 May 2024 15:39:27 +0200
>>>> 
>>>> The code in the attached file tries to parse src/lisp.h but crashes
>>>> while printing the result:  emacs --batch -l ts-bug.el
>>> 
>>> Yuan, can you help, please?
>>> 
>>> Btw, why do you use treesit-parse-string?  The Emacs integration with
>>> tree-sitter can parse a buffer without making a string from its
>>> contents.
>> 
>> Yep, I’ll look into it.
>> 
>> Yuan
> 
> Just an update, I didn’t forget about this. If I didn’t reply back today, I will in a few days :-)
> 
> Yuan

From what I can gather, the crash seems to be because the temp buffer is garbage collected—the inserted lisp.h is a large file, so the temp buffer is probably immediately collected, before Emacs tries to print the node in the next line. I replaced the insert-file-content with some smaller file and it didn’t crash.

But that theory has critical flaws: a) Emacs certainly doesn't collect the temp buffer before the with-temp-buffer form returns; b) I can’t crash Emacs in my non-debug build by inserting (garbage-collect) in front of the message line in the example; c) debug build Emacs still crashes even if I enlarge gc-cons-threshold.

Eli, is there anything different regarding temp buffers in debug builds?

Yuan

bug#71012: 30.0.50; tree-sitter crash

[Eli Zaretskii]

> From: Yuan Fu <casouri@gmail.com>
> Date: Tue, 28 May 2024 22:15:05 -0700
> Cc: Helmut Eller <eller.helmut@gmail.com>,
>  71012@debbugs.gnu.org
> 
> From what I can gather, the crash seems to be because the temp buffer is garbage collected—the inserted lisp.h is a large file, so the temp buffer is probably immediately collected, before Emacs tries to print the node in the next line. I replaced the insert-file-content with some smaller file and it didn’t crash.

It is unthinkable that a buffer is GC'ed while it is being used.

> But that theory has critical flaws: a) Emacs certainly doesn't collect the temp buffer before the with-temp-buffer form returns; b) I can’t crash Emacs in my non-debug build by inserting (garbage-collect) in front of the message line in the example; c) debug build Emacs still crashes even if I enlarge gc-cons-threshold.
> 
> Eli, is there anything different regarding temp buffers in debug builds?

No.

But note that there are _two_ temporary buffers involved here: one is
created in ts-bug.el, and it remains intact and valid; the other is
the temporary buffer created by treesit-parse-string.  That one is
killed by the time treesit-parse-string returns, so treesit-node-start
attempts to access positions of a killed buffer!

So I think this is a bug in treesit-parse-string: it cannot use
with-temp-buffer; instead, it should make the buffer into which it
inserts the string part of the parser, so that the buffer is killed
and GC'ed only when the parser is no longer referenced.  Otherwise the
syntax tree returned by treesit-parse-string is unsafe to use.

bug#71012: 30.0.50; tree-sitter crash

[Yuan Fu]

> On May 29, 2024, at 5:28 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> From: Yuan Fu <casouri@gmail.com>
>> Date: Tue, 28 May 2024 22:15:05 -0700
>> Cc: Helmut Eller <eller.helmut@gmail.com>,
>> 71012@debbugs.gnu.org
>> 
>> From what I can gather, the crash seems to be because the temp buffer is garbage collected—the inserted lisp.h is a large file, so the temp buffer is probably immediately collected, before Emacs tries to print the node in the next line. I replaced the insert-file-content with some smaller file and it didn’t crash.
> 
> It is unthinkable that a buffer is GC'ed while it is being used.
> 
>> But that theory has critical flaws: a) Emacs certainly doesn't collect the temp buffer before the with-temp-buffer form returns; b) I can’t crash Emacs in my non-debug build by inserting (garbage-collect) in front of the message line in the example; c) debug build Emacs still crashes even if I enlarge gc-cons-threshold.
>> 
>> Eli, is there anything different regarding temp buffers in debug builds?
> 
> No.
> 
> But note that there are _two_ temporary buffers involved here: one is
> created in ts-bug.el, and it remains intact and valid; the other is
> the temporary buffer created by treesit-parse-string.  That one is
> killed by the time treesit-parse-string returns, so treesit-node-start
> attempts to access positions of a killed buffer!
> 
> So I think this is a bug in treesit-parse-string: it cannot use
> with-temp-buffer; instead, it should make the buffer into which it
> inserts the string part of the parser, so that the buffer is killed
> and GC'ed only when the parser is no longer referenced.  Otherwise the
> syntax tree returned by treesit-parse-string is unsafe to use.

I see, you’re absolutely right, thanks for the analysis! On top of that I need to make sure all the treesit function checks for buffer liveness before accessing the buffer. I was under the impression that a killed buffer would keep its content around until it’s collected. Turns out that wasn’t the case.

Yuan

bug#71012: 30.0.50; tree-sitter crash

[Yuan Fu]

> On Jun 1, 2024, at 10:15 AM, Yuan Fu <casouri@gmail.com> wrote:
> 
> 
> 
>> On May 29, 2024, at 5:28 AM, Eli Zaretskii <eliz@gnu.org> wrote:
>> 
>>> From: Yuan Fu <casouri@gmail.com>
>>> Date: Tue, 28 May 2024 22:15:05 -0700
>>> Cc: Helmut Eller <eller.helmut@gmail.com>,
>>> 71012@debbugs.gnu.org
>>> 
>>> From what I can gather, the crash seems to be because the temp buffer is garbage collected—the inserted lisp.h is a large file, so the temp buffer is probably immediately collected, before Emacs tries to print the node in the next line. I replaced the insert-file-content with some smaller file and it didn’t crash.
>> 
>> It is unthinkable that a buffer is GC'ed while it is being used.
>> 
>>> But that theory has critical flaws: a) Emacs certainly doesn't collect the temp buffer before the with-temp-buffer form returns; b) I can’t crash Emacs in my non-debug build by inserting (garbage-collect) in front of the message line in the example; c) debug build Emacs still crashes even if I enlarge gc-cons-threshold.
>>> 
>>> Eli, is there anything different regarding temp buffers in debug builds?
>> 
>> No.
>> 
>> But note that there are _two_ temporary buffers involved here: one is
>> created in ts-bug.el, and it remains intact and valid; the other is
>> the temporary buffer created by treesit-parse-string.  That one is
>> killed by the time treesit-parse-string returns, so treesit-node-start
>> attempts to access positions of a killed buffer!
>> 
>> So I think this is a bug in treesit-parse-string: it cannot use
>> with-temp-buffer; instead, it should make the buffer into which it
>> inserts the string part of the parser, so that the buffer is killed
>> and GC'ed only when the parser is no longer referenced.  Otherwise the
>> syntax tree returned by treesit-parse-string is unsafe to use.
> 
> I see, you’re absolutely right, thanks for the analysis! On top of that I need to make sure all the treesit function checks for buffer liveness before accessing the buffer. I was under the impression that a killed buffer would keep its content around until it’s collected. Turns out that wasn’t the case.
> 
> Yuan

Pushed the fix to emacs-29.

Yuan

bug#71012: 30.0.50; tree-sitter crash

[Yuan Fu]

> On Jun 1, 2024, at 10:43 AM, Yuan Fu <casouri@gmail.com> wrote:
> 
> 
> 
>> On Jun 1, 2024, at 10:15 AM, Yuan Fu <casouri@gmail.com> wrote:
>> 
>> 
>> 
>>> On May 29, 2024, at 5:28 AM, Eli Zaretskii <eliz@gnu.org> wrote:
>>> 
>>>> From: Yuan Fu <casouri@gmail.com>
>>>> Date: Tue, 28 May 2024 22:15:05 -0700
>>>> Cc: Helmut Eller <eller.helmut@gmail.com>,
>>>> 71012@debbugs.gnu.org
>>>> 
>>>> From what I can gather, the crash seems to be because the temp buffer is garbage collected—the inserted lisp.h is a large file, so the temp buffer is probably immediately collected, before Emacs tries to print the node in the next line. I replaced the insert-file-content with some smaller file and it didn’t crash.
>>> 
>>> It is unthinkable that a buffer is GC'ed while it is being used.
>>> 
>>>> But that theory has critical flaws: a) Emacs certainly doesn't collect the temp buffer before the with-temp-buffer form returns; b) I can’t crash Emacs in my non-debug build by inserting (garbage-collect) in front of the message line in the example; c) debug build Emacs still crashes even if I enlarge gc-cons-threshold.
>>>> 
>>>> Eli, is there anything different regarding temp buffers in debug builds?
>>> 
>>> No.
>>> 
>>> But note that there are _two_ temporary buffers involved here: one is
>>> created in ts-bug.el, and it remains intact and valid; the other is
>>> the temporary buffer created by treesit-parse-string.  That one is
>>> killed by the time treesit-parse-string returns, so treesit-node-start
>>> attempts to access positions of a killed buffer!
>>> 
>>> So I think this is a bug in treesit-parse-string: it cannot use
>>> with-temp-buffer; instead, it should make the buffer into which it
>>> inserts the string part of the parser, so that the buffer is killed
>>> and GC'ed only when the parser is no longer referenced.  Otherwise the
>>> syntax tree returned by treesit-parse-string is unsafe to use.
>> 
>> I see, you’re absolutely right, thanks for the analysis! On top of that I need to make sure all the treesit function checks for buffer liveness before accessing the buffer. I was under the impression that a killed buffer would keep its content around until it’s collected. Turns out that wasn’t the case.
>> 
>> Yuan
> 
> Pushed the fix to emacs-29.
> 
> Yuan
> 

The fix works for me so I’m closing this report. Feel free to followup if new problems occur :-)

Yuan

bug#71012: 30.0.50; tree-sitter crash

[Basil L. Contovounesios]

Just curious: since generate-new-buffer creates a new buffer each time
it is called, is it guaranteed that this buffer will eventually be GCed,
once the caller of treesit-parse-string is done with it?

Thanks,
-- 
Basil

bug#71012: 30.0.50; tree-sitter crash

[Basil L. Contovounesios]

BTW, not sure if this is the right bug report, but currently on master I
see the following test failure:

  make TEST_LOAD_EL=no test/treesit-tests
  make -C test treesit-tests
  make[1]: Entering directory '/home/blc/.local/src/emacs/test'
  make[2]: Entering directory '/home/blc/.local/src/emacs/test'
    GEN      src/treesit-tests.log
  Running 28 tests (2024-06-10 10:11:18+0200, selector `(not (or (tag :unstable) (tag :nativecomp)))')
     passed   1/28  treesit-basic-parsing (0.000398 sec)
     passed   2/28  treesit-cross-boundary (0.000307 sec)
     passed   3/28  treesit-cursor-helper-with-missing-node (0.000217 sec)
  Can't guess python-indent-offset, using defaults: 4
     passed   4/28  treesit-defun-navigation-nested-1 (0.038371 sec)
     passed   5/28  treesit-defun-navigation-nested-2 (0.058591 sec)
     passed   6/28  treesit-defun-navigation-nested-3 (0.002775 sec)
     passed   7/28  treesit-defun-navigation-nested-4 (0.003478 sec)
  Can't guess python-indent-offset, using defaults: 4
     passed   8/28  treesit-defun-navigation-top-level (0.003415 sec)
     passed   9/28  treesit-indirect-buffer (0.000249 sec)
     passed  10/28  treesit-multi-lang (0.000739 sec)
     passed  11/28  treesit-narrow (0.000216 sec)
  Test treesit-node-api backtrace:
  make[2]: *** [Makefile:185: src/treesit-tests.log] Aborted (core dumped)
  make[2]: Leaving directory '/home/blc/.local/src/emacs/test'
  make[1]: *** [Makefile:251: src/treesit-tests] Error 2
  make[1]: Leaving directory '/home/blc/.local/src/emacs/test'
  make: *** [Makefile:1133: test/treesit-tests] Error 2

And no treesit-tests.log file is generated.

-- 
Basil

bug#71012: 30.0.50; tree-sitter crash

[Eli Zaretskii]

> Cc: 71012@debbugs.gnu.org, eller.helmut@gmail.com
> From: "Basil L. Contovounesios" <basil@contovou.net>
> Date: Mon, 10 Jun 2024 10:12:51 +0200
> 
> BTW, not sure if this is the right bug report, but currently on master I
> see the following test failure:
> 
>   make TEST_LOAD_EL=no test/treesit-tests
>   make -C test treesit-tests
>   make[1]: Entering directory '/home/blc/.local/src/emacs/test'
>   make[2]: Entering directory '/home/blc/.local/src/emacs/test'
>     GEN      src/treesit-tests.log
>   Running 28 tests (2024-06-10 10:11:18+0200, selector `(not (or (tag :unstable) (tag :nativecomp)))')
>      passed   1/28  treesit-basic-parsing (0.000398 sec)
>      passed   2/28  treesit-cross-boundary (0.000307 sec)
>      passed   3/28  treesit-cursor-helper-with-missing-node (0.000217 sec)
>   Can't guess python-indent-offset, using defaults: 4
>      passed   4/28  treesit-defun-navigation-nested-1 (0.038371 sec)
>      passed   5/28  treesit-defun-navigation-nested-2 (0.058591 sec)
>      passed   6/28  treesit-defun-navigation-nested-3 (0.002775 sec)
>      passed   7/28  treesit-defun-navigation-nested-4 (0.003478 sec)
>   Can't guess python-indent-offset, using defaults: 4
>      passed   8/28  treesit-defun-navigation-top-level (0.003415 sec)
>      passed   9/28  treesit-indirect-buffer (0.000249 sec)
>      passed  10/28  treesit-multi-lang (0.000739 sec)
>      passed  11/28  treesit-narrow (0.000216 sec)
>   Test treesit-node-api backtrace:
>   make[2]: *** [Makefile:185: src/treesit-tests.log] Aborted (core dumped)
>   make[2]: Leaving directory '/home/blc/.local/src/emacs/test'
>   make[1]: *** [Makefile:251: src/treesit-tests] Error 2
>   make[1]: Leaving directory '/home/blc/.local/src/emacs/test'
>   make: *** [Makefile:1133: test/treesit-tests] Error 2
> 
> And no treesit-tests.log file is generated.

Mattias fixed the crash, and I then fixed the test not to fail.

So I'm now closing this bug.

bug#71012: 30.0.50; tree-sitter crash

[Yuan Fu]

> On Jun 10, 2024, at 11:25 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> Cc: 71012@debbugs.gnu.org, eller.helmut@gmail.com
>> From: "Basil L. Contovounesios" <basil@contovou.net>
>> Date: Mon, 10 Jun 2024 10:12:51 +0200
>> 
>> BTW, not sure if this is the right bug report, but currently on master I
>> see the following test failure:
>> 
>>  make TEST_LOAD_EL=no test/treesit-tests
>>  make -C test treesit-tests
>>  make[1]: Entering directory '/home/blc/.local/src/emacs/test'
>>  make[2]: Entering directory '/home/blc/.local/src/emacs/test'
>>    GEN      src/treesit-tests.log
>>  Running 28 tests (2024-06-10 10:11:18+0200, selector `(not (or (tag :unstable) (tag :nativecomp)))')
>>     passed   1/28  treesit-basic-parsing (0.000398 sec)
>>     passed   2/28  treesit-cross-boundary (0.000307 sec)
>>     passed   3/28  treesit-cursor-helper-with-missing-node (0.000217 sec)
>>  Can't guess python-indent-offset, using defaults: 4
>>     passed   4/28  treesit-defun-navigation-nested-1 (0.038371 sec)
>>     passed   5/28  treesit-defun-navigation-nested-2 (0.058591 sec)
>>     passed   6/28  treesit-defun-navigation-nested-3 (0.002775 sec)
>>     passed   7/28  treesit-defun-navigation-nested-4 (0.003478 sec)
>>  Can't guess python-indent-offset, using defaults: 4
>>     passed   8/28  treesit-defun-navigation-top-level (0.003415 sec)
>>     passed   9/28  treesit-indirect-buffer (0.000249 sec)
>>     passed  10/28  treesit-multi-lang (0.000739 sec)
>>     passed  11/28  treesit-narrow (0.000216 sec)
>>  Test treesit-node-api backtrace:
>>  make[2]: *** [Makefile:185: src/treesit-tests.log] Aborted (core dumped)
>>  make[2]: Leaving directory '/home/blc/.local/src/emacs/test'
>>  make[1]: *** [Makefile:251: src/treesit-tests] Error 2
>>  make[1]: Leaving directory '/home/blc/.local/src/emacs/test'
>>  make: *** [Makefile:1133: test/treesit-tests] Error 2
>> 
>> And no treesit-tests.log file is generated.
> 
> Mattias fixed the crash, and I then fixed the test not to fail.
> 
> So I'm now closing this bug.

Thank you!

Yuan

bug#71012: 30.0.50; tree-sitter crash

[Yuan Fu]

> On Jun 7, 2024, at 1:39 AM, Basil L. Contovounesios <basil@contovou.net> wrote:
> 
> Just curious: since generate-new-buffer creates a new buffer each time
> it is called, is it guaranteed that this buffer will eventually be GCed,
> once the caller of treesit-parse-string is done with it?

Yeah, from my testing that seems to be the case.

Yuan

bug#71012: 30.0.50; tree-sitter crash

[Basil L. Contovounesios]

Yuan Fu [2024-06-11 22:38 -0700] wrote:

>> On Jun 7, 2024, at 1:39 AM, Basil L. Contovounesios <basil@contovou.net> wrote:
>> 
>> Just curious: since generate-new-buffer creates a new buffer each time
>> it is called, is it guaranteed that this buffer will eventually be GCed,
>> once the caller of treesit-parse-string is done with it?
>
> Yeah, from my testing that seems to be the case.

What did you try?
I'm putting the following in an emacs -Q *scratch* buffer:

  (require 'treesit)
  (message "# of buffers before : %d" (length (buffer-list)))
  (dotimes-with-progress-reporter (i 10000) "Parsing"
    (treesit-parse-string "int c = 0;" 'c))
  (garbage-collect)
  (message "# of buffers after  : %d" (length (buffer-list)))

Each time I M-x eval-buffer:
- the list of buffers grows
- the memory usage grows
- loop iterations slow down noticeably

Am I missing something?

-- 
Basil

bug#71012: 30.0.50; tree-sitter crash

[Basil L. Contovounesios]

By the way, this shouldn't make a big difference by default, but did you
consider calling generate-new-buffer with a non-nil optional argument (à
la with-temp-buffer) in treesit-parse-string?

-- 
Basil