From 7f18811668708e7d0505596c0cdb7a15ba3a5fcf Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Thu, 10 Jul 2025 20:30:39 +0800
Subject: [PATCH] vim-patch:32a1b26: runtime(filetype): improve asm heuristics
 and move into FTasmsyntax() (#34863)

fixes: vim/vim#17474
closes: vim/vim#17683

https://github.com/vim/vim/commit/32a1b26ef3e821de9b5c518829b08002e933fa5a

vim-patch:41ee98c: runtime(filetype): fix incorrect pattern and break early

- Using `\n` is incorrect, as result of getline() does not contain line
  breaks and only uses `\n` for NUL bytes.
- Return when b:asmsyntax is set, like many other filetypes.

closes: vim/vim#17706

https://github.com/vim/vim/commit/41ee98c3c5342867cb99dfcddbe8d53caeda22db

Co-authored-by: Wu Yongwei <wuyongwei@gmail.com>
---
 runtime/lua/vim/filetype/detect.lua | 55 ++++++++++++++++++-----------
 1 file changed, 35 insertions(+), 20 deletions(-)

diff --git a/runtime/lua/vim/filetype/detect.lua b/runtime/lua/vim/filetype/detect.lua
index 07bb02029b..10ecefc7d2 100644
--- a/runtime/lua/vim/filetype/detect.lua
+++ b/runtime/lua/vim/filetype/detect.lua
@@ -31,15 +31,9 @@ local matchregex = vim.filetype._matchregex
 -- luacheck: push ignore 122
 
 -- This function checks for the kind of assembly that is wanted by the user, or
--- can be detected from the first five lines of the file.
+-- can be detected from the beginning of the file.
 --- @type vim.filetype.mapfn
 function M.asm(path, bufnr)
-  -- tiasm uses `* comment`
-  local lines = table.concat(getlines(bufnr, 1, 10), '\n')
-  if findany(lines, { '^%*', '\n%*', 'Texas Instruments Incorporated' }) then
-    return 'tiasm'
-  end
-
   local syntax = vim.b[bufnr].asmsyntax
   if not syntax or syntax == '' then
     syntax = M.asm_syntax(path, bufnr)
@@ -58,6 +52,40 @@ function M.asm(path, bufnr)
   end
 end
 
+-- Checks the first lines for a asmsyntax=foo override.
+-- Only whitespace characters can be present immediately before or after this statement.
+--- @type vim.filetype.mapfn
+function M.asm_syntax(_, bufnr)
+  local lines = ' ' .. table.concat(getlines(bufnr, 1, 5), ' '):lower() .. ' '
+  local match = lines:match('%sasmsyntax=([a-zA-Z0-9]+)%s')
+  if match then
+    return match
+  end
+  local is_slash_star_encountered = false
+  for _, line in ipairs(getlines(bufnr, 1, 50)) do
+    if line:find('^/%*') then
+      is_slash_star_encountered = true
+    end
+    if
+      line:find('^; Listing generated by Microsoft')
+      or matchregex(
+        line,
+        [[\c^\%(\%(CONST\|_BSS\|_DATA\|_TEXT\)\s\+SEGMENT\>\)\|\s*\.[2-6]86P\?\>\|\s*\.XMM\>]]
+      )
+    then
+      return 'masm'
+    elseif
+      line:find('Texas Instruments Incorporated')
+      -- tiasm uses `* commment`, but detection is unreliable if '/*' is seen
+      or (line:find('^%*') and not is_slash_star_encountered)
+    then
+      return 'tiasm'
+    elseif matchregex(line, [[\c\.title\>\|\.ident\>\|\.macro\>\|\.subtitle\>\|\.library\>]]) then
+      return 'vmasm'
+    end
+  end
+end
+
 --- Active Server Pages (with Perl or Visual Basic Script)
 --- @type vim.filetype.mapfn
 function M.asp(_, bufnr)
@@ -69,19 +97,6 @@ function M.asp(_, bufnr)
   return 'aspvbs'
 end
 
--- Checks the first 5 lines for a asmsyntax=foo override.
--- Only whitespace characters can be present immediately before or after this statement.
---- @type vim.filetype.mapfn
-function M.asm_syntax(_, bufnr)
-  local lines = ' ' .. table.concat(getlines(bufnr, 1, 5), ' '):lower() .. ' '
-  local match = lines:match('%sasmsyntax=([a-zA-Z0-9]+)%s')
-  if match then
-    return match
-  elseif findany(lines, { '%.title', '%.ident', '%.macro', '%.subtitle', '%.library' }) then
-    return 'vmasm'
-  end
-end
-
 local visual_basic_content =
   [[\c^\s*\%(Attribute\s\+VB_Name\|Begin\s\+\%(VB\.\|{\%(\x\+-\)\+\x\+}\)\)]]