patch 9.1.0616: filetype: Make syntax highlighting off for MS Makefiles

Problem:  filetype: Make syntax highlighting off for MS Makefiles
Solution: Try to detect MS Makefiles and adjust syntax rules to it.
          (Ken Takata)

Highlighting of variable expansion in Microsoft Makefile can be broken.
E.g.:
2979cfc262/src/Make_mvc.mak (L1331)

Don't use backslash as escape characters if `make_microsoft` is set.
Also fix that `make_no_comments` was not considered if `make_microsoft`
was set.

Also add description for `make_microsoft` and `make_no_comments` to the
documentation and include a very simple filetype test

closes: #15341

Signed-off-by: Christian Brabandt <cb@256bit.org>
Signed-off-by: Ken Takata <kentkt@csc.jp>

runtime/autoload/dist/ft.vim

@@ -532,6 +532,25 @@ export def FTm()
   endif
 enddef
 
+export def FTmake()
+  # Check if it is a Microsoft Makefile
+  unlet! b:make_microsoft
+  var n = 1
+  while n < 1000 && n <= line('$')
+    var line = getline(n)
+    if line =~? '^\s*!\s*\(ifn\=\(def\)\=\|include\|message\|error\)\>'
+      b:make_microsoft = 1
+      break
+    elseif line =~ '^ *ifn\=\(eq\|def\)\>' || line =~ '^ *[-s]\=include\s'
+      break
+    elseif line =~ '^ *\w\+\s*[!?:+]='
+      break
+    endif
+    n += 1
+  endwhile
+  setf make
+enddef
+
 export def FTmms()
   var n = 1
   while n < 20

runtime/doc/syntax.txt

@@ -1,4 +1,4 @@
-*syntax.txt*	For Vim version 9.1.  Last change: 2024 Jul 23
+*syntax.txt*	For Vim version 9.1.  Last change: 2024 Jul 25
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -2289,6 +2289,16 @@ feature off by using: >
 
 	:let make_no_commands = 1
 
+Comments are also highlighted by default.  You can turn this off by using: >
+
+	:let make_no_comments = 1
+
+Microsoft Makefile handles variable expansion and comments differently
+(backslashes are not used for escape).  If you see any wrong highlights
+because of this, you can try this: >
+
+	:let make_microsoft = 1
+
 
 MAPLE						*maple.vim* *ft-maple-syntax*
 

runtime/filetype.vim

@@ -1387,7 +1387,7 @@ au BufNewFile,BufRead */etc/mail/aliases,*/etc/aliases	setf mailaliases
 au BufNewFile,BufRead .mailcap,mailcap		setf mailcap
 
 " Makefile
-au BufNewFile,BufRead *[mM]akefile,*.mk,*.mak	setf make
+au BufNewFile,BufRead *[mM]akefile,*.mk,*.mak	call dist#ft#FTmake()
 au BufNewFile,BufRead Kbuild			setf make
 
 " MakeIndex

runtime/syntax/make.vim

@@ -28,8 +28,13 @@ syn match makePreCondit "^!\s*\(cmdswitches\|error\|message\|include\|if\|ifdef\
 syn case match
 
 " identifiers
+if exists("b:make_microsoft") || exists("make_microsoft")
+  syn region makeIdent	start="\$(" end=")" contains=makeStatement,makeIdent
+  syn region makeIdent	start="\${" end="}" contains=makeStatement,makeIdent
+else
   syn region makeIdent	start="\$(" skip="\\)\|\\\\" end=")" contains=makeStatement,makeIdent
   syn region makeIdent	start="\${" skip="\\}\|\\\\" end="}" contains=makeStatement,makeIdent
+endif
 syn match makeIdent	"\$\$\w*"
 syn match makeIdent	"\$[^({]"
 syn match makeIdent	"^ *[^:#= \t]*\s*[:+?!*]="me=e-2
@@ -78,12 +83,14 @@ syn match makeOverride	"^ *override\>"
 syn match makeStatement contained "(\(abspath\|addprefix\|addsuffix\|and\|basename\|call\|dir\|error\|eval\|file\|filter-out\|filter\|findstring\|firstword\|flavor\|foreach\|guile\|if\|info\|join\|lastword\|notdir\|or\|origin\|patsubst\|realpath\|shell\|sort\|strip\|subst\|suffix\|value\|warning\|wildcard\|word\|wordlist\|words\)\>"ms=s+1
 
 " Comment
-if exists("make_microsoft")
+if !exists("make_no_comments")
+  if exists("b:make_microsoft") || exists("make_microsoft")
     syn match   makeComment	"#.*" contains=@Spell,makeTodo
-elseif !exists("make_no_comments")
+  else
     syn region  makeComment	start="#" end="^$" end="[^\\]$" keepend contains=@Spell,makeTodo
     syn match   makeComment	"#$" contains=@Spell
   endif
+endif
 syn keyword makeTodo TODO FIXME XXX contained
 
 " match escaped quotes and any other escaped character

src/testdir/test_filetype.vim

@@ -2646,4 +2646,21 @@ func Test_pl_file()
   filetype off
 endfunc
 
+func Test_make_file()
+  filetype on
+
+  " Microsoft Makefile
+  call writefile(['# Makefile for Windows', '!if "$(VIMDLL)" == "yes"'], 'XMakefile.mak', 'D')
+  split XMakefile.mak
+  call assert_equal(1, get(b:, 'make_microsoft', 0))
+  bwipe!
+
+  call writefile(['# get the list of tests', 'include testdir/Make_all.mak'], 'XMakefile.mak', 'D')
+  split XMakefile.mak
+  call assert_equal(0, get(b:, 'make_microsoft', 0))
+  bwipe!
+
+  filetype off
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    616,
 /**/
     615,
 /**/