bug#63390: 29.0.90; c-ts-mode fails to recognize functions in xterm.c

[Eli Zaretskii <eliz@gnu.org>]

Yuan, could you please look into this?

> Date: Tue, 09 May 2023 15:03:08 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> 
> To reproduce:
> 
>   emacs -Q
>   M-x load-library RET c-ts-mode RET
>   C-x C-f src/xterm.c
>   C-u 8290 M-g g
> 
> Observe that the name of the function x_draw_glyph_string_foreground
> is not fontified in font-lock-function-name-face, but in the default
> face.
> 
> Starting treesit-explore-mode seems to indicate that tree-sitter
> interprets this as a function declaration, not a function definition:
> 
>   (function_declarator declarator: (identifier)
>    parameters: 
>     (parameter_list (
>      (parameter_declaration
>       type: (struct_specifier struct name: (type_identifier))
>       declarator: (pointer_declarator * declarator: (identifier)))
>      )))
> 
> Same with the next function, x_draw_composite_glyph_string_foreground.
> But the function after that, x_draw_glyphless_glyph_string_foreground,
> is again recognized as function definition.  I wonder if the
> preprocessor conditionals around there have something to do with that.
> 
> Btw, function declarations in a header file are recognized as such,
> but the names of the functions there are still correctly fontified.
> 
> In GNU Emacs 29.0.90 (build 88, i686-pc-mingw32) of 2023-05-09 built on
>  HOME-C4E4A596F7
> Repository revision: 387ddc0ccc1b21f612b9106bafec63170ede30e6
> Repository branch: emacs-29
> Windowing system distributor 'Microsoft Corp.', version 5.1.2600
> System Description: Microsoft Windows XP Service Pack 3 (v5.1.0.2600)
> 
> Configured using:
>  'configure -C --prefix=/d/usr --with-wide-int
>  --enable-checking=yes,glyphs 'CFLAGS=-O0 -gdwarf-4 -g3''
> 
> Configured features:
> ACL GIF GMP GNUTLS HARFBUZZ JPEG JSON LCMS2 LIBXML2 MODULES 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: C/*
> 
> Minor modes in effect:
>   bug-reference-prog-mode: t
>   treesit-explore-mode: t
>   tooltip-mode: t
>   global-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:
> (shadow sort mail-extr emacsbug message mailcap yank-media puny dired
> dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg rfc6068
> epg-config gnus-util text-property-search time-date subr-x mm-decode
> mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
> sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils vc-git
> diff-mode easy-mmode vc-dispatcher bug-reference byte-opt gv bytecomp
> byte-compile c-ts-mode c-ts-common treesit cl-seq thingatpt cl-loaddefs
> cl-lib find-func rmc iso-transl tooltip cconv eldoc paren electric
> uniquify ediff-hook vc-hooks lisp-float-type 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 scroll-bar mouse jit-lock
> font-lock syntax font-core term/tty-colors frame minibuffer nadvice seq
> simple cl-generic indonesian philippine 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 abbrev obarray oclosure cl-preloaded button
> loaddefs theme-loaddefs faces cus-face macroexp files window
> text-properties overlay sha1 md5 base64 format env code-pages mule
> custom widget keymap hashtable-print-readable backquote threads
> w32notify w32 lcms2 multi-tty make-network-process emacs)
> 
> Memory information:
> ((conses 16 97345 9002)
>  (symbols 48 7923 0)
>  (strings 16 22587 2046)
>  (string-bytes 1 609997)
>  (vectors 16 12738)
>  (vector-slots 8 179418 12186)
>  (floats 8 31 52)
>  (intervals 40 6159 809)
>  (buffers 888 12))
> 
> 
> 
>