neovim/runtime/syntax/config.vim

" Vim syntax file
" Language:		configure.in script: M4 with sh
" Maintainer:	Christian Hammesr <ch@lathspell.westend.com>
" Last Change:	2015 Jan 14
" 				(patch from Yngve Inntjore Levinsen to detect AC_MSG)
" 				(patch from Khym Chanur to add @Spell)

" Well, I actually even do not know much about m4. This explains why there
" is probably very much missing here, yet !
" But I missed good highlighting when editing my GNU autoconf/automake
" script, so I wrote this quick and dirty patch.


" For version 5.x: Clear all syntax items
" For version 6.x: Quit when a syntax file was already loaded
if version < 600
  syntax clear
elseif exists("b:current_syntax")
  finish
endif

" define the config syntax
syn match   configdelimiter "[()\[\];,]"
syn match   configoperator  "[=|&\*\+\<\>]"
syn match   configcomment   "\(dnl.*\)\|\(#.*\)" contains=configDnl,@Spell
syn match   configfunction  "\<[A-Z_][A-Z0-9_]*\>"
syn match   confignumber    "[-+]\=\<\d\+\(\.\d*\)\=\>"
syn keyword configDnl   	dnl contained
syn keyword configkeyword   if then else fi test for in do done
syn keyword configspecial   cat rm eval

" This shortens the script, see syn-ext-match..
syn region  configstring    start=+\z(["'`]\)+ skip=+\\\z1+ end=+\z1+ contains=@Spell

" Anything inside AC_MSG_TYPE([...])  and AC_MSG_TYPE(...) is a string.
syn region  configstring matchgroup=configfunction start="AC_MSG_[A-Z]*\ze(\[" matchgroup=configdelimiter end="\])" contains=configdelimiter,@Spell
syn region  configstring matchgroup=configfunction start="AC_MSG_[A-Z]*\ze([^[]" matchgroup=configdelimiter end=")" contains=configdelimiter,@Spell

" Define the default highlighting.
" For version 5.7 and earlier: only when not done already
" For version 5.8 and later: only when an item doesn't have highlighting yet
if version >= 508 || !exists("did_config_syntax_inits")
  if version < 508
    let did_config_syntax_inits = 1
    command -nargs=+ HiLink hi link <args>
  else
    command -nargs=+ HiLink hi def link <args>
  endif

  HiLink configdelimiter Delimiter
  HiLink configoperator  Operator
  HiLink configcomment   Comment
  HiLink configDnl  	 Comment
  HiLink configfunction  Function
  HiLink confignumber    Number
  HiLink configkeyword   Keyword
  HiLink configspecial   Special
  HiLink configstring    String

  delcommand HiLink
endif

let b:current_syntax = "config"

" vim: ts=4