diff --git a/lib/libc/regex/data/att/README b/lib/libc/regex/data/att/README
index e2ee6f6ef705..86b72eb0479f 100644
--- a/lib/libc/regex/data/att/README
+++ b/lib/libc/regex/data/att/README
@@ -1,8 +1,12 @@
-AT&T test data from: http://www2.research.att.com/~gsf/testregex/
+AT&T test data from:
+    http://www2.research.att.com/~gsf/testregex/
+
+The above link does not exist anymore; a copy of it is maintained at:
+    https://github.com/gburd/testregex
 
 Quoting from the page:
     testregex.c 2004-05-31 is the latest source for the AT&T Research
     regression test harness for the X/Open regex pattern match interface.
     See testregex(1) for option and test input details. The source and
     test data posted here are license free.
 
diff --git a/usr.bin/xlint/lint1/check-expect.lua b/usr.bin/xlint/lint1/check-expect.lua
index dde258973d4f..95ba60267cc8 100644
--- a/usr.bin/xlint/lint1/check-expect.lua
+++ b/usr.bin/xlint/lint1/check-expect.lua
@@ -1,277 +1,277 @@
 #!  /usr/bin/lua
--- $NetBSD: check-expect.lua,v 1.7 2023/07/08 11:03:00 rillig Exp $
+-- $NetBSD: check-expect.lua,v 1.8 2023/08/11 04:27:49 rillig Exp $
 
 --[[
 
 usage: lua ./check-expect.lua *.c
 
 Check that the /* expect+-n: ... */ comments in the .c source files match the
 actual messages found in the corresponding .exp files.  The .exp files are
 expected in the current working directory.
 
 The .exp files are generated on the fly during the ATF tests, see
 t_integration.sh.  During development, they can be generated using
 lint1/accept.sh.
 ]]
 
 
 local function test(func)
   func()
 end
 
 local function assert_equals(got, expected)
   if got ~= expected then
     assert(false, string.format("got %q, expected %q", got, expected))
   end
 end
 
 
 local had_errors = false
 ---@param fmt string
 function print_error(fmt, ...)
   print(fmt:format(...))
   had_errors = true
 end
 
 
 local function load_lines(fname)
   local lines = {}
 
   local f, err, errno = io.open(fname, "r")
   if f == nil then return nil, err, errno end
 
   for line in f:lines() do
     table.insert(lines, line)
   end
   f:close()
 
   return lines
 end
 
 
 local function save_lines(fname, lines)
   local f = io.open(fname, "w")
   for _, line in ipairs(lines) do
     f:write(line .. "\n")
   end
   f:close()
 end
 
 
 -- Load the 'expect:' comments from a C source file.
 --
 -- example return values:
 --   {
---     ["file.c(18)"] = {"invalid argument 'a'", "invalid argument 'b'"},
+--     ["file.c(18)"] = {"syntax error 'a' [249]", "syntax error 'b' [249]"},
 --     ["file.c(23)"] = {"not a constant expression [123]"},
 --   },
 --   { "file.c(18)", "file.c(23)" }
 local function load_c(fname)
   local basename = fname:match("([^/]+)$")
   local lines = load_lines(fname)
   if lines == nil then return nil, nil end
 
   local pp_fname = fname
   local pp_lineno = 0
   local comment_locations = {}
   local comments_by_location = {}
 
   local function add_expectation(offset, message)
     local location = ("%s(%d)"):format(pp_fname, pp_lineno + offset)
     if comments_by_location[location] == nil then
       table.insert(comment_locations, location)
       comments_by_location[location] = {}
     end
     local trimmed_msg = message:match("^%s*(.-)%s*$")
     table.insert(comments_by_location[location], trimmed_msg)
   end
 
   for phys_lineno, line in ipairs(lines) do
 
     for offset, comment in line:gmatch("/%* expect([+%-]%d+): (.-) %*/") do
       add_expectation(tonumber(offset), comment)
     end
 
     pp_lineno = pp_lineno + 1
 
     local ppl_lineno, ppl_fname = line:match("^#%s*(%d+)%s+\"([^\"]+)\"")
     if ppl_lineno ~= nil then
       if ppl_fname == basename and tonumber(ppl_lineno) ~= phys_lineno + 1 then
         print_error("error: %s:%d: preprocessor line number must be %d",
           fname, phys_lineno, phys_lineno + 1)
       end
       if ppl_fname:match("%.c$") and ppl_fname ~= basename then
         print_error("error: %s:%d: preprocessor filename must be '%s'",
           fname, phys_lineno, basename)
       end
       pp_fname = ppl_fname
       pp_lineno = ppl_lineno
     end
   end
 
   return comment_locations, comments_by_location
 end
 
 
 -- Load the expected raw lint output from a .exp file.
 --
 -- example return value: {
 --   {
 --     exp_lineno = 18,
 --     location = "file.c(18)",
 --     message = "not a constant expression [123]",
 --   }
 -- }
 local function load_exp(exp_fname)
 
   local lines = load_lines(exp_fname)
   if lines == nil then
     print_error("check-expect.lua: error: file " .. exp_fname .. " not found")
     return
   end
 
   local messages = {}
   for exp_lineno, line in ipairs(lines) do
-    for location, message in line:gmatch("(%S+%(%d+%)): (.+)$") do
+    for location, message in line:gmatch("(.+%(%d+%)): (.+)$") do
       table.insert(messages, {
         exp_lineno = exp_lineno,
         location = location,
         message = message
       })
     end
   end
 
   return messages
 end
 
 
 local function matches(comment, pattern)
   if comment == "" then return false end
 
   local any_prefix = pattern:sub(1, 3) == "..."
   if any_prefix then pattern = pattern:sub(4) end
   local any_suffix = pattern:sub(-3) == "..."
   if any_suffix then pattern = pattern:sub(1, -4) end
 
   if any_prefix and any_suffix then
     return comment:find(pattern, 1, true) ~= nil
   elseif any_prefix then
     return pattern ~= "" and comment:sub(-#pattern) == pattern
   elseif any_suffix then
     return comment:sub(1, #pattern) == pattern
   else
     return comment == pattern
   end
 end
 
 test(function()
   assert_equals(matches("a", "a"), true)
   assert_equals(matches("a", "b"), false)
   assert_equals(matches("a", "aaa"), false)
 
   assert_equals(matches("abc", "a..."), true)
   assert_equals(matches("abc", "c..."), false)
 
   assert_equals(matches("abc", "...c"), true)
   assert_equals(matches("abc", "...a"), false)
 
   assert_equals(matches("abc123xyz", "...a..."), true)
   assert_equals(matches("abc123xyz", "...b..."), true)
   assert_equals(matches("abc123xyz", "...c..."), true)
   assert_equals(matches("abc123xyz", "...1..."), true)
   assert_equals(matches("abc123xyz", "...2..."), true)
   assert_equals(matches("abc123xyz", "...3..."), true)
   assert_equals(matches("abc123xyz", "...x..."), true)
   assert_equals(matches("abc123xyz", "...y..."), true)
   assert_equals(matches("abc123xyz", "...z..."), true)
   assert_equals(matches("pattern", "...pattern..."), true)
 end)
 
 
 -- Inserts the '/* expect */' lines to the .c file, so that the .c file matches
 -- the .exp file.  Multiple 'expect' comments for a single line of code are not
 -- handled correctly, but it's still better than doing the same work manually.
 local function insert_missing(missing)
   for fname, items in pairs(missing) do
     table.sort(items, function(a, b) return a.lineno > b.lineno end)
     local lines = assert(load_lines(fname))
     for _, item in ipairs(items) do
       local lineno, message = item.lineno, item.message
       local indent = (lines[lineno] or ""):match("^([ \t]*)")
       local line = ("%s/* expect+1: %s */"):format(indent, message)
       table.insert(lines, lineno, line)
     end
     save_lines(fname, lines)
   end
 end
 
 
 local function check_test(c_fname, update)
   local exp_fname = c_fname:gsub("%.c$", ".exp"):gsub(".+/", "")
 
   local c_comment_locations, c_comments_by_location = load_c(c_fname)
   if c_comment_locations == nil then return end
 
   local exp_messages = load_exp(exp_fname) or {}
   local missing = {}
 
   for _, exp_message in ipairs(exp_messages) do
     local c_comments = c_comments_by_location[exp_message.location] or {}
     local expected_message =
       exp_message.message:gsub("/%*", "**"):gsub("%*/", "**")
 
     local found = false
     for i, c_comment in ipairs(c_comments) do
       if c_comment ~= "" and matches(expected_message, c_comment) then
         c_comments[i] = ""
         found = true
         break
       end
     end
 
     if not found then
       print_error("error: %s: missing /* expect+1: %s */",
         exp_message.location, expected_message)
 
       if update then
         local fname = exp_message.location:match("^([^(]+)")
         local lineno = tonumber(exp_message.location:match("%((%d+)%)$"))
         if not missing[fname] then missing[fname] = {} end
         table.insert(missing[fname], {
           lineno = lineno,
           message = expected_message,
         })
       end
     end
   end
 
   for _, c_comment_location in ipairs(c_comment_locations) do
     for _, c_comment in ipairs(c_comments_by_location[c_comment_location]) do
       if c_comment ~= "" then
         print_error(
           "error: %s: declared message \"%s\" is not in the actual output",
           c_comment_location, c_comment)
       end
     end
   end
 
   if missing then
     insert_missing(missing)
   end
 end
 
 
 local function main(args)
   local update = args[1] == "-u"
   if update then
     table.remove(args, 1)
   end
 
   for _, name in ipairs(args) do
     check_test(name, update)
   end
 end
 
 
 main(arg)
 os.exit(not had_errors)
diff --git a/usr.bin/xlint/lint1/msg_255.c b/usr.bin/xlint/lint1/msg_255.c
index bde80cc97e3c..1a7f60f8d7b0 100644
--- a/usr.bin/xlint/lint1/msg_255.c
+++ b/usr.bin/xlint/lint1/msg_255.c
@@ -1,13 +1,45 @@
-/*	$NetBSD: msg_255.c,v 1.5 2023/07/09 11:01:27 rillig Exp $	*/
+/*	$NetBSD: msg_255.c,v 1.6 2023/08/11 04:27:49 rillig Exp $	*/
 # 3 "msg_255.c"
 
 // Test for message: undefined or invalid '#' directive [255]
 
 /* lint1-extra-flags: -X 351 */
 
+/* expect+1: warning: undefined or invalid '#' directive [255] */
+#
+
+/* expect+1: warning: undefined or invalid '#' directive [255] */
+#pragma
+
 #pragma once
 
 /* expect+1: warning: undefined or invalid '#' directive [255] */
 #fatal_error
 
+/* expect+1: warning: undefined or invalid '#' directive [255] */
+#    ident "obsolete"
+
+/* expect+1: warning: undefined or invalid '#' directive [255] */
+#1
+
+// Sets the line number of the current file.
+# 2
+
+// Switch back to the main file.
+# 30 "msg_255.c"
+
+/* expect+1: warning: undefined or invalid '#' directive [255] */
+# 3/
+
+/* expect+1: warning: undefined or invalid '#' directive [255] */
+# 4 /
+
+/* expect+1: warning: undefined or invalid '#' directive [255] */
+# 5 "unfinished
+
+// An empty string means standard input; tabs may be used for spacing.
+#	6	""
+
+# 44 "msg_255.c"
+
 int dummy;