patch 9.1.0505: filetype: Faust files are not recognized

Problem:  filetype: Faust files are not recognized
Solution: Detect '*.lib' files as Faust filetype, add detection for
          '*.dsp' files (Faust or Make), remove '*.lib' from Cobol
          filetype (PowerUser64)

closes: #14894

Signed-off-by: PowerUser64 <blake@blakenorth.net>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/autoload/dist/ft.vim

@@ -1265,6 +1265,56 @@ export def FTtyp()
   setf typst
 enddef
 
+# Detect Microsoft Developer Studio Project files (Makefile) or Faust DSP
+# files.
+export def FTdsp()
+  if exists("g:filetype_dsp")
+    exe "setf " .. g:filetype_dsp
+    return
+  endif
+
+  # Test the filename
+  if expand('%:t') =~ '^[mM]akefile.*$'
+    setf make
+    return
+  endif
+
+  # Test the file contents
+  for line in getline(1, 200)
+    # Chech for comment style
+    if line =~ '^#.*'
+      setf make
+      return
+    endif
+
+    # Check for common lines
+    if line =~ '^.*Microsoft Developer Studio Project File.*$'
+      setf make
+      return
+    endif
+
+    if line =~ '^!MESSAGE This is not a valid makefile\..+$'
+      setf make
+      return
+    endif
+
+    # Check for keywords
+    if line =~ '^!(IF,ELSEIF,ENDIF).*$'
+      setf make
+      return
+    endif
+
+    # Check for common assignments
+    if line =~ '^SOURCE=.*$'
+      setf make
+      return
+    endif
+  endfor
+
+  # Otherwise, assume we have a Faust file
+  setf faust
+enddef
+
 # Set the filetype of a *.v file to Verilog, V or Cog based on the first 200
 # lines.
 export def FTv()

runtime/doc/filetype.txt

@@ -149,6 +149,7 @@ variables can be used to overrule the filetype used for certain extensions:
 	*.csh		g:filetype_csh		|ft-csh-syntax|
 	*.dat		g:filetype_dat
 	*.def		g:filetype_def
+	*.dsp		g:filetype_dsp
 	*.f		g:filetype_f		|ft-forth-syntax|
 	*.frm		g:filetype_frm		|ft-form-syntax|
 	*.fs		g:filetype_fs		|ft-forth-syntax|

runtime/filetype.vim

@@ -457,7 +457,7 @@ au BufNewFile,BufRead */.cmus/{autosave,rc,command-history,*.theme} setf cmusrc
 au BufNewFile,BufRead */cmus/{rc,*.theme}			setf cmusrc
 
 " Cobol
-au BufNewFile,BufRead *.cbl,*.cob,*.lib	setf cobol
+au BufNewFile,BufRead *.cbl,*.cob	setf cobol
 "   cobol or zope form controller python script? (heuristic)
 au BufNewFile,BufRead *.cpy
 	\ if getline(1) =~ '^##' |
@@ -532,6 +532,10 @@ au BufNewFile,BufRead s6-*                              setf execline
 " Fontconfig config files
 au BufNewFile,BufRead fonts.conf			setf xml
 
+" Faust
+au BufNewFile,BufRead *.lib				setf faust
+au BufNewFile,BufRead *.dsp				call dist#ft#FTdsp()
+
 " Libreoffice config files
 au BufNewFile,BufRead *.xcu,*.xlb,*.xlc,*.xba		setf xml
 au BufNewFile,BufRead psprint.conf,sofficerc		setf dosini
@@ -1365,8 +1369,8 @@ 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,*.dsp setf make
-au BufNewFile,BufRead Kbuild setf make
+au BufNewFile,BufRead *[mM]akefile,*.mk,*.mak	setf make
+au BufNewFile,BufRead Kbuild			setf make
 
 " MakeIndex
 au BufNewFile,BufRead *.ist,*.mst		setf ist