1 files changed, 190 insertions, 0 deletions
diff --git a/unit-tests/check-expect.lua b/unit-tests/check-expect.lua
new file mode 100644
index 000000000000..218056fbc021
--- /dev/null
+++ b/unit-tests/check-expect.lua
@@ -0,0 +1,190 @@
+#!  /usr/bin/lua
+-- $NetBSD: check-expect.lua,v 1.13 2025/04/13 09:29:32 rillig Exp $
+
+--[[
+
+usage: lua ./check-expect.lua *.mk
+
+Check that the various 'expect' comments in the .mk files produce the
+expected text in the corresponding .exp file.
+
+# expect: <line>
+        All of these lines must occur in the .exp file, in the same order as
+        in the .mk file.
+
+# expect-reset
+        Search the following 'expect:' comments from the top of the .exp
+        file again.
+
+# expect[+-]offset: <message>
+        Each message must occur in the .exp file and refer back to the
+        source line in the .mk file.
+
+# expect-not: <substring>
+        The substring must not occur as part of any line of the .exp file.
+
+# expect-not-matches: <pattern>
+        The pattern (see https://lua.org/manual/5.4/manual.html#6.4.1)
+        must not occur as part of any line of the .exp file.
+]]
+
+
+local had_errors = false
+---@param fmt string
+function print_error(fmt, ...)
+  print(fmt:format(...))
+  had_errors = true
+end
+
+
+---@return nil | string[]
+local function load_lines(fname)
+  local lines = {}
+
+  local f = io.open(fname, "r")
+  if f == nil then return nil end
+
+  for line in f:lines() do
+    table.insert(lines, line)
+  end
+  f:close()
+
+  return lines
+end
+
+
+---@param exp_lines string[]
+local function collect_lineno_diagnostics(exp_lines)
+  ---@type table<string, string[]>
+  local by_location = {}
+
+  for _, line in ipairs(exp_lines) do
+    ---@type string | nil, string, string
+    local l_fname, l_lineno, l_msg =
+      line:match('^make: ([^:]+):(%d+): (.*)')
+    if l_fname ~= nil then
+      local location = ("%s:%d"):format(l_fname, l_lineno)
+      if by_location[location] == nil then
+        by_location[location] = {}
+      end
+      table.insert(by_location[location], l_msg)
+    end
+  end
+
+  return by_location
+end
+
+
+local function missing(by_location)
+  ---@type {filename: string, lineno: number, location: string, message: string}[]
+  local missing_expectations = {}
+
+  for location, messages in pairs(by_location) do
+    for _, message in ipairs(messages) do
+      if message ~= "" and location:find(".mk:") then
+        local filename, lineno = location:match("^(%S+):(%d+)$")
+        table.insert(missing_expectations, {
+          filename = filename,
+          lineno = tonumber(lineno),
+          location = location,
+          message = message
+        })
+      end
+    end
+  end
+  table.sort(missing_expectations, function(a, b)
+    if a.filename ~= b.filename then
+      return a.filename < b.filename
+    end
+    return a.lineno < b.lineno
+  end)
+  return missing_expectations
+end
+
+
+local function check_mk(mk_fname)
+  local exp_fname = mk_fname:gsub("%.mk$", ".exp")
+  local mk_lines = load_lines(mk_fname)
+  local exp_lines = load_lines(exp_fname)
+  if exp_lines == nil then return end
+  local by_location = collect_lineno_diagnostics(exp_lines)
+  local prev_expect_line = 0
+
+  for mk_lineno, mk_line in ipairs(mk_lines) do
+
+    for text in mk_line:gmatch("#%s*expect%-not:%s*(.*)") do
+      local i = 1
+      while i <= #exp_lines and not exp_lines[i]:find(text, 1, true) do
+        i = i + 1
+      end
+      if i <= #exp_lines then
+        print_error("error: %s:%d: %s must not contain '%s'",
+          mk_fname, mk_lineno, exp_fname, text)
+      end
+    end
+
+    for text in mk_line:gmatch("#%s*expect%-not%-matches:%s*(.*)") do
+      local i = 1
+      while i <= #exp_lines and not exp_lines[i]:find(text) do
+        i = i + 1
+      end
+      if i <= #exp_lines then
+        print_error("error: %s:%d: %s must not match '%s'",
+          mk_fname, mk_lineno, exp_fname, text)
+      end
+    end
+
+    for text in mk_line:gmatch("#%s*expect:%s*(.*)") do
+      local i = prev_expect_line
+      -- As of 2022-04-15, some lines in the .exp files contain trailing
+      -- whitespace.  If possible, this should be avoided by rewriting the
+      -- debug logging.  When done, the trailing gsub can be removed.
+      -- See deptgt-phony.exp lines 14 and 15.
+      while i < #exp_lines and text ~= exp_lines[i + 1]:gsub("^%s*", ""):gsub("%s*$", "") do
+        i = i + 1
+      end
+      if i < #exp_lines then
+        prev_expect_line = i + 1
+      else
+        print_error("error: %s:%d: '%s:%d+' must contain '%s'",
+          mk_fname, mk_lineno, exp_fname, prev_expect_line + 1, text)
+      end
+    end
+    if mk_line:match("^#%s*expect%-reset$") then
+      prev_expect_line = 0
+    end
+
+    ---@param text string
+    for offset, text in mk_line:gmatch("#%s*expect([+%-]%d+):%s*(.*)") do
+      local location = ("%s:%d"):format(mk_fname, mk_lineno + tonumber(offset))
+
+      local found = false
+      if by_location[location] ~= nil then
+        for i, message in ipairs(by_location[location]) do
+          if message == text then
+            by_location[location][i] = ""
+            found = true
+            break
+          elseif message ~= "" then
+            print_error("error: %s:%d: out-of-order '%s'",
+              mk_fname, mk_lineno, message)
+          end
+        end
+      end
+
+      if not found then
+        print_error("error: %s:%d: %s must contain '%s'",
+          mk_fname, mk_lineno, exp_fname, text)
+      end
+    end
+  end
+
+  for _, m in ipairs(missing(by_location)) do
+    print_error("missing: %s: # expect+1: %s", m.location, m.message)
+  end
+end
+
+for _, fname in ipairs(arg) do
+  check_mk(fname)
+end
+os.exit(not had_errors)