vim-patch:9.1.0505: filetype: Faust files are not recognized (#29426)

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: vim/vim#14894

https://github.com/vim/vim/commit/aa61b8a9087e9cd999ef07e0d87b60f43d68f2c6

Co-authored-by: PowerUser64 <blake@blakenorth.net>

1 files changed, 35 insertions, 0 deletions

diff --git a/runtime/lua/vim/filetype/detect.lua b/runtime/lua/vim/filetype/detect.lua
index 997b53ba4b..b52dba7388 100644
--- a/runtime/lua/vim/filetype/detect.lua
+++ b/runtime/lua/vim/filetype/detect.lua
@@ -472,6 +472,41 @@ function M.def(_, bufnr)
 end
 
 --- @type vim.filetype.mapfn
+function M.dsp(path, bufnr)
+  if vim.g.filetype_dsp then
+    return vim.g.filetype_dsp
+  end
+
+  -- Test the filename
+  local file_name = fn.fnamemodify(path, ':t')
+  if file_name:find('^[mM]akefile.*$') then
+    return 'make'
+  end
+
+  -- Test the file contents
+  for _, line in ipairs(getlines(bufnr, 1, 200)) do
+    if
+      findany(line, {
+        -- Check for comment style
+        [[#.*]],
+        -- Check for common lines
+        [[^.*Microsoft Developer Studio Project File.*$]],
+        [[^!MESSAGE This is not a valid makefile\..+$]],
+        -- Check for keywords
+        [[^!(IF,ELSEIF,ENDIF).*$]],
+        -- Check for common assignments
+        [[^SOURCE=.*$]],
+      })
+    then
+      return 'make'
+    end
+  end
+
+  -- Otherwise, assume we have a Faust file
+  return 'faust'
+end
+
+--- @type vim.filetype.mapfn
 function M.e(_, bufnr)
   if vim.g.filetype_euphoria then
     return vim.g.filetype_euphoria