Commit: runtime(m4): Remove m4Function

[Christian Brabandt]

runtime(m4): Remove m4Function

Commit: https://github.com/vim/vim/commit/efb913a4f5d2ff07807fd40bda651571174a9589
Author: Damien Lejay <dam...@lejay.be>
Date: Sat Sep 6 15:16:06 2025 +0200

runtime(m4): Remove m4Function

closes: https://github.com/vim/vim/issues/18211

Signed-off-by: Damien Lejay <dam...@lejay.be>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/runtime/syntax/m4.vim b/runtime/syntax/m4.vim
index 9d5116087..8d28ab3a9 100644
--- a/runtime/syntax/m4.vim
+++ b/runtime/syntax/m4.vim
@@ -4,10 +4,7 @@
" Last Change: 2022 Jun 12
" 2025 Sep 2 by Vim project: fix a few syntax issues #18192
" 2025 Sep 5 by Vim project: introduce m4Disabled region #18200
-
-" This file will highlight user function calls if they use only
-" capital letters and have at least one argument (i.e. the '('
-" must be there). Let me know if this is a problem.
+" 2025 Sep 6 by Vim project: remove m4Function heuristics #18211

" quit when a syntax file was already loaded
if !exists("main_syntax")
@@ -45,6 +42,13 @@ syn region m4Quoted
" – Comments themselves are disabled when quoted.
syn region m4Disabled start=+#+ end=+$+ containedin=ALLBUT,m4Quoted

+" Macros in M4:
+" – Name tokens consist of the longest possible sequence of letters, digits,
+" and underscores, where the first character is not a digit.
+" – In GNU M4, this can be altered with changeword().
+" – Any name token may be defined as a macro and quoting prevents expansion.
+" Thus correct highlighting requires running M4.
+
" define the m4 syntax
syn match m4Variable contained "\$\d\+"
syn match m4Special contained "$[@*#]"
@@ -59,15 +63,13 @@ syn region m4Command matchgroup=m4Statement start="\<\(m4_\)\=\(syscmd\|esyscmd
syn region m4Command matchgroup=m4Builtin start="\<\(m4_\)\=\(len\|index\|regexp\|substr\|translit\|patsubst\|format\|incr\|decr\|eval\|maketemp\)("he=e-1 end=")" contains=@m4Top
syn keyword m4Statement divert undivert
syn region m4Command matchgroup=m4Type start="\<\(m4_\)\=\(undefine\|popdef\)("he=e-1 end=")" contains=@m4Top
-syn region m4Function matchgroup=m4Type start="\<[_A-Z][_A-Z0-9]*("he=e-1 end=")" contains=@m4Top
-syn cluster m4Top contains=m4Comment,m4Constants,m4Special,m4Variable,m4Paren,m4Command,m4Statement,m4Function,m4Quoted
+syn cluster m4Top contains=m4Comment,m4Constants,m4Special,m4Variable,m4Paren,m4Command,m4Statement,m4Quoted

" Define the default highlighting.
" Only when an item doesn't have highlighting yet
hi def link m4QuoteDelim Delimiter
hi def link m4Delimiter Delimiter
hi def link m4Comment Comment
-hi def link m4Function Function
hi def link m4Keyword Keyword
hi def link m4Special Special
hi def link m4Statement Statement