diff --git a/runtime/syntax/cmacro.vim b/runtime/syntax/cmacro.vim
new file mode 100644
index 0000000..1d448f0
--- /dev/null
+++ b/runtime/syntax/cmacro.vim
@@ -0,0 +1,77 @@
+" Vim syntax file
+" Language:	C macro for C preprocessor
+" Maintainer:	Wu, Zhenyu <wuzhenyu@ustc.edu>
+" Last Change:	2024 Dec 31
+" modified from syntax/c.vim
+
+" C compiler has a preprocessor: `cpp -P test.txt`
+" test.txt doesn't need to be a C file
+if exists("b:current_syntax")
+  finish
+endif
+
+let s:cpo_save = &cpo
+set cpo&vim
+
+" Accept %: for # (C99)
+syn region	cmacroPreCondit	start="^\s*\zs\%(%:\|#\)\s*\%(if\|ifdef\|ifndef\|elif\)\>" skip="\\$" end="$" keepend contains=cmacroCppParen,cmacroNumbers
+syn match	cmacroPreConditMatch	display "^\s*\zs\%(%:\|#\)\s*\%(else\|endif\)\>"
+if !exists("c_no_if0")
+  syn cluster	cmacroCppOutInGroup	contains=cmacroCppInIf,cmacroCppInElse,cmacroCppInElse2,cmacroCppOutIf,cmacroCppOutIf2,cmacroCppOutElse,cmacroCppInSkip,cmacroCppOutSkip
+  syn region	cmacroCppOutWrapper	start="^\s*\zs\%(%:\|#\)\s*if\s\+0\+\s*\%($\|//\|/\*\|&\)" end=".\@=\|$" contains=cmacroCppOutIf,cmacroCppOutElse,@NoSpell fold
+  syn region	cmacroCppOutIf	contained start="0\+" matchgroup=cmacroCppOutWrapper end="^\s*\%(%:\|#\)\s*endif\>" contains=cmacroCppOutIf2,cmacroCppOutElse
+  if !exists("c_no_if0_fold")
+    syn region	cmacroCppOutIf2	contained matchgroup=cmacroCppOutWrapper start="0\+" end="^\s*\%(%:\|#\)\s*\%(else\>\|elif\s\+\%(0\+\s*\%($\|//\|/\*\|&\)\)\@!\|endif\>\)"me=s-1 contains=cmacroCppOutSkip,@Spell fold
+  else
+    syn region	cmacroCppOutIf2	contained matchgroup=cmacroCppOutWrapper start="0\+" end="^\s*\%(%:\|#\)\s*\%(else\>\|elif\s\+\%(0\+\s*\%($\|//\|/\*\|&\)\)\@!\|endif\>\)"me=s-1 contains=cmacroCppOutSkip,@Spell
+  endif
+  syn region	cmacroCppOutElse	contained matchgroup=cmacroCppOutWrapper start="^\s*\%(%:\|#\)\s*\%(else\|elif\)" end="^\s*\%(%:\|#\)\s*endif\>"me=s-1 contains=TOP,cmacroPreCondit
+  syn region	cmacroCppInWrapper	start="^\s*\zs\%(%:\|#\)\s*if\s\+0*[1-9]\d*\s*\%($\|//\|/\*\||\)" end=".\@=\|$" contains=cmacroCppInIf,cmacroCppInElse fold
+  syn region	cmacroCppInIf	contained matchgroup=cmacroCppInWrapper start="\d\+" end="^\s*\%(%:\|#\)\s*endif\>" contains=TOP,cmacroPreCondit
+  if !exists("c_no_if0_fold")
+    syn region	cmacroCppInElse	contained start="^\s*\%(%:\|#\)\s*\%(else\>\|elif\s\+\%(0*[1-9]\d*\s*\%($\|//\|/\*\||\)\)\@!\)" end=".\@=\|$" containedin=cmacroCppInIf contains=cmacroCppInElse2 fold
+  else
+    syn region	cmacroCppInElse	contained start="^\s*\%(%:\|#\)\s*\%(else\>\|elif\s\+\%(0*[1-9]\d*\s*\%($\|//\|/\*\||\)\)\@!\)" end=".\@=\|$" containedin=cmacroCppInIf contains=cmacroCppInElse2
+  endif
+  syn region	cmacroCppInElse2	contained matchgroup=cmacroCppInWrapper start="^\s*\%(%:\|#\)\s*\%(else\|elif\)\%([^/]\|/[^/*]\)*" end="^\s*\%(%:\|#\)\s*endif\>"me=s-1 contains=cmacroCppOutSkip,@Spell
+  syn region	cmacroCppOutSkip	contained start="^\s*\%(%:\|#\)\s*\%(if\>\|ifdef\>\|ifndef\>\)" skip="\\$" end="^\s*\%(%:\|#\)\s*endif\>" contains=cmacroCppOutSkip
+  syn region	cmacroCppInSkip	contained matchgroup=cmacroCppInWrapper start="^\s*\%(%:\|#\)\s*\%(if\s\+\%(\d\+\s*\%($\|//\|/\*\||\|&\)\)\@!\|ifdef\>\|ifndef\>\)" skip="\\$" end="^\s*\%(%:\|#\)\s*endif\>" containedin=cmacroCppOutElse,cmacroCppInIf,cmacroCppInSkip contains=TOP,cmacroPreProc
+endif
+syn region	cmacroIncluded	display contained start=+"+ skip=+\\\\\|\\"+ end=+"+
+syn match	cmacroIncluded	display contained "<[^>]*>"
+syn match	cmacroInclude	display "^\s*\zs\%(%:\|#\)\s*include\>\s*["<]" contains=cmacroIncluded
+"syn match cmacroLineSkip	"\\$"
+syn cluster	cmacroPreProcmacroGroup	contains=cmacroPreCondit,cmacroIncluded,cmacroInclude,cmacroDefine,cmacroCppOutWrapper,cmacroCppInWrapper,@cmacroCppOutInGroup,cmacroNumbersCom,@cmacroCommentGroup,cmacroParen,cmacroBracket,cmacroMulti,cmacroBadBlock
+syn region	cmacroDefine		start="^\s*\zs\%(%:\|#\)\s*\%(define\|undef\)\>" skip="\\$" end="$" keepend contains=ALLBUT,@cmacroPreProcmacroGroup,@Spell
+syn region	cmacroPreProc	start="^\s*\zs\%(%:\|#\)\s*\%(pragma\>\|line\>\|warning\>\|warn\>\|error\>\)" skip="\\$" end="$" keepend contains=ALLBUT,@cmacroPreProcmacroGroup,@Spell
+
+" be able to fold #pragma regions
+syn region	cmacroPragma		start="^\s*#pragma\s\+region\>" end="^\s*#pragma\s\+endregion\>" transparent keepend extend fold
+
+syn keyword cmacroTodo			contained TODO FIXME XXX NOTE
+syn region  cmacroComment		start='/\*' end='\*/' contains=cmacroTodo,@Spell
+syn match   cmacroCommentError "\*/"
+syn region  cmacroComment		start='//' end='$' contains=cmacroTodo,@Spell
+
+" Define the default highlighting.
+" Only used when an item doesn't have highlighting yet
+hi def link cmacroInclude		Include
+hi def link cmacroPreProc		PreProc
+hi def link cmacroDefine		Macro
+hi def link cmacroIncluded		cmacroString
+hi def link cmacroCppInWrapper	cmacroCppOutWrapper
+hi def link cmacroCppOutWrapper	cmacroPreCondit
+hi def link cmacroPreConditMatch	cmacroPreCondit
+hi def link cmacroPreCondit		PreCondit
+hi def link cmacroCppOutSkip		cmacroCppOutIf2
+hi def link cmacroCppInElse2		cmacroCppOutIf2
+hi def link cmacroCppOutIf2		cmacroCppOut
+hi def link cmacroCppOut		Comment
+hi def link cmacroTodo			Todo
+hi def link cmacroComment		Comment
+hi def link cmacroCommentError		Error
+
+let b:current_syntax = "cmacro"
+
+let &cpo = s:cpo_save
+unlet s:cpo_save