bug#62825: 29.0.90; c-ts-mode doesn't recognize DEFUN functions

bug#62825: 29.0.90; c-ts-mode doesn't recognize DEFUN functions

[Eli Zaretskii]

Evaluating '(treesit-defun-at-point)' inside a function defined via
the DEFUN macro yields nil, when the buffer is under c-ts-mode.  This
gets in the way of significant functionalities, like
c-ts-mode-indent-defun and generating ChangeLog-style log entries
using "C-x 4 a" and the likes.

To reproduce, visit any of the Emacs C source files, like treesit.c,
with c-ts-mode, move point to a function defined via DEFUN, and type
"C-x 4 a".  The resulting ChangeLog entry will have the file name, but
not the expected function name in parentheses.

Please fix this ASAP, this is a bad regression for those, like myself,
who want to use c-ts-mode.

In GNU Emacs 29.0.90 (build 2, i686-pc-mingw32) of 2023-04-10 built on
 HOME-C4E4A596F7
Windowing system distributor 'Microsoft Corp.', version 5.1.2600
System Description: Microsoft Windows XP Service Pack 3 (v5.1.0.2600)

Configured using:
 'configure --prefix=/d/usr --with-wide-int --with-native-compilation
 'CFLAGS=-O2 -gdwarf-4 -g3''

Configured features:
ACL GIF GMP GNUTLS HARFBUZZ JPEG JSON LCMS2 LIBXML2 MODULES NATIVE_COMP
NOTIFY W32NOTIFY PDUMPER PNG RSVG SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER WEBP XPM ZLIB

Important settings:
  value of $LANG: ENU
  locale-coding-system: cp1255

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
None found.

Features:
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ietf-drums mm-util mail-prsvr mail-utils rmc iso-transl tooltip cconv
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elisp-mode mwheel dos-w32 ls-lisp disp-table term/w32-win w32-win
w32-vars 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
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threads w32notify w32 lcms2 multi-tty make-network-process
native-compile emacs)

Memory information:
((conses 16 83196 14093)
 (symbols 48 8277 0)
 (strings 16 22852 2978)
 (string-bytes 1 598231)
 (vectors 16 16223)
 (vector-slots 8 320282 14191)
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 (intervals 40 293 0)
 (buffers 888 12))

bug#62825: 29.0.90; c-ts-mode doesn't recognize DEFUN functions

[Eli Zaretskii]

> Date: Fri, 14 Apr 2023 09:44:22 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> 
> Evaluating '(treesit-defun-at-point)' inside a function defined via
> the DEFUN macro yields nil, when the buffer is under c-ts-mode.  This
> gets in the way of significant functionalities, like
> c-ts-mode-indent-defun and generating ChangeLog-style log entries
> using "C-x 4 a" and the likes.
> 
> To reproduce, visit any of the Emacs C source files, like treesit.c,
> with c-ts-mode, move point to a function defined via DEFUN, and type
> "C-x 4 a".  The resulting ChangeLog entry will have the file name, but
> not the expected function name in parentheses.
> 
> Please fix this ASAP, this is a bad regression for those, like myself,
> who want to use c-ts-mode.

Using treesit-explore-mode I see that c-ts-mode regards DEFUN
functions as a sequence of 2 expression_statement nodes.  Here's the
tree corresponding to the DEFUN macro call:

  (expression_statement
   (call_expression
    function: 
     (call_expression function: (identifier) <<<<<<<<<<<<<<<<<<<
      arguments: 
       (argument_list (
	(string_literal " ")
	, (identifier) , (identifier) , (number_literal) , (number_literal) ,
		      (number_literal)
	, (identifier)
	(ERROR :)
	(comment) )))
    arguments: 
     (argument_list ( (identifier)
      (ERROR (identifier))
      , (identifier)
      (ERROR (identifier))
      )))
   ;)

The identifier node on the line indicated with "<<<<<" is "DEFUN", so
maybe we can recognize this.  The body of the DEFUN is another
compound_statement node, following the DEFUN's node.

bug#62825: 29.0.90; c-ts-mode doesn't recognize DEFUN functions

[Yuan Fu]

> On Apr 13, 2023, at 11:59 PM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> Date: Fri, 14 Apr 2023 09:44:22 +0300
>> From: Eli Zaretskii <eliz@gnu.org>
>> 
>> Evaluating '(treesit-defun-at-point)' inside a function defined via
>> the DEFUN macro yields nil, when the buffer is under c-ts-mode.  This
>> gets in the way of significant functionalities, like
>> c-ts-mode-indent-defun and generating ChangeLog-style log entries
>> using "C-x 4 a" and the likes.
>> 
>> To reproduce, visit any of the Emacs C source files, like treesit.c,
>> with c-ts-mode, move point to a function defined via DEFUN, and type
>> "C-x 4 a".  The resulting ChangeLog entry will have the file name, but
>> not the expected function name in parentheses.
>> 
>> Please fix this ASAP, this is a bad regression for those, like myself,
>> who want to use c-ts-mode.
> 
> Using treesit-explore-mode I see that c-ts-mode regards DEFUN
> functions as a sequence of 2 expression_statement nodes.  Here's the
> tree corresponding to the DEFUN macro call:
> 
>  (expression_statement
>   (call_expression
>    function: 
>     (call_expression function: (identifier) <<<<<<<<<<<<<<<<<<<
>      arguments: 
>       (argument_list (
> (string_literal " ")
> , (identifier) , (identifier) , (number_literal) , (number_literal) ,
>      (number_literal)
> , (identifier)
> (ERROR :)
> (comment) )))
>    arguments: 
>     (argument_list ( (identifier)
>      (ERROR (identifier))
>      , (identifier)
>      (ERROR (identifier))
>      )))
>   ;)
> 
> The identifier node on the line indicated with "<<<<<" is "DEFUN", so
> maybe we can recognize this.  The body of the DEFUN is another
> compound_statement node, following the DEFUN's node.

Ok, I fixed indent-defund and add-log. Because a DEFUN is made of two nodes in the parse tree rather than one, it’s a bit hard to incorporate it into the normal treesit-defun-at-point, etc, functions. And we probably have to fix DEFUN case-by-case.

Yuan

bug#62825: 29.0.90; c-ts-mode doesn't recognize DEFUN functions

[Eli Zaretskii]

> From: Yuan Fu <casouri@gmail.com>
> Date: Fri, 14 Apr 2023 13:19:41 -0700
> Cc: Theodor Thornhill <theo@thornhill.no>,
>  62825@debbugs.gnu.org
> 
> Ok, I fixed indent-defund and add-log. Because a DEFUN is made of two nodes in the parse tree rather than one, it’s a bit hard to incorporate it into the normal treesit-defun-at-point, etc, functions. And we probably have to fix DEFUN case-by-case.

Thanks.  But I wonder why do we need the c-ts-mode-emacs-devel knob.
Why not recognize DEFUN by default everywhere?  CC Mode does that,
AFAIK, so why shouldn't c-ts-mode do the same?

bug#62825: 29.0.90; c-ts-mode doesn't recognize DEFUN functions

[Yuan Fu]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Yuan Fu <casouri@gmail.com>
>> Date: Fri, 14 Apr 2023 13:19:41 -0700
>> Cc: Theodor Thornhill <theo@thornhill.no>,
>>  62825@debbugs.gnu.org
>> 
>> Ok, I fixed indent-defund and add-log. Because a DEFUN is made of
>> two nodes in the parse tree rather than one, it’s a bit hard to
>> incorporate it into the normal treesit-defun-at-point, etc,
>> functions. And we probably have to fix DEFUN case-by-case.
>
> Thanks.  But I wonder why do we need the c-ts-mode-emacs-devel knob.
> Why not recognize DEFUN by default everywhere?  CC Mode does that,
> AFAIK, so why shouldn't c-ts-mode do the same?

I just thought the fix is a bit hacky, and does add some overhead, so
people who don’t need it might not be happy to know that they can’t turn
it off.

Yuan

bug#62825: 29.0.90; c-ts-mode doesn't recognize DEFUN functions

[Eli Zaretskii]

> From: Yuan Fu <casouri@gmail.com>
> Date: Sat, 15 Apr 2023 22:37:02 -0700
> Cc: 62825@debbugs.gnu.org,
>  theo@thornhill.no
> 
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Thanks.  But I wonder why do we need the c-ts-mode-emacs-devel knob.
> > Why not recognize DEFUN by default everywhere?  CC Mode does that,
> > AFAIK, so why shouldn't c-ts-mode do the same?
> 
> I just thought the fix is a bit hacky, and does add some overhead, so
> people who don’t need it might not be happy to know that they can’t turn
> it off.

OK, but I made it into a defcustom and turned this on by default.  I
also renamed a few symbols, please take a look.

Btw, should the code you added to c-ts-mode--defun-name recognize
DEFUN nodes only when this variable is non-nil?

bug#62825: 29.0.90; c-ts-mode doesn't recognize DEFUN functions

[Yuan Fu]

> On Apr 16, 2023, at 1:14 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
>> From: Yuan Fu <casouri@gmail.com>
>> Date: Sat, 15 Apr 2023 22:37:02 -0700
>> Cc: 62825@debbugs.gnu.org,
>> theo@thornhill.no
>> 
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>>> Thanks.  But I wonder why do we need the c-ts-mode-emacs-devel knob.
>>> Why not recognize DEFUN by default everywhere?  CC Mode does that,
>>> AFAIK, so why shouldn't c-ts-mode do the same?
>> 
>> I just thought the fix is a bit hacky, and does add some overhead, so
>> people who don’t need it might not be happy to know that they can’t turn
>> it off.
> 
> OK, but I made it into a defcustom and turned this on by default.  I
> also renamed a few symbols, please take a look.

Thanks.

> 
> Btw, should the code you added to c-ts-mode--defun-name recognize
> DEFUN nodes only when this variable is non-nil?

I don’t think it’s necessary, we only need to inhibit creating DEFUN nodes when the feature is turned-off, ie, we only need to control the entry points. 

Yuan