Improved error messages

sys/apps/shell.lua

@@ -52,8 +52,8 @@ local function run(...)
 		loadFn = loadfile
 	end
 
-	local fn, err = loadFn(path, env)
-	if not fn then
+	local bill, err = loadFn(path, env)
+	if not bill then
 		error(err, -1)
 	end
 
@@ -68,7 +68,7 @@ local function run(...)
 	}
 
 	env[ "arg" ] = { [0] = path, table.unpack(args) }
-	local r = { fn(table.unpack(args)) }
+	local r = { bill(table.unpack(args)) }
 
 	tProgramStack[#tProgramStack] = nil
 

sys/init/7.multishell.lua

@@ -106,17 +106,34 @@ function multishell.openTab(env, tab)
 	end
 	tab.title = tab.title or 'untitled'
 	tab.window = tab.window or window.create(parentTerm, 1, 2, w, h - 1, false)
-	tab.onExit = tab.onExit or function(self, result, err)
-		if not result and err and err ~= 'Terminated' or (err and err ~= 0) then
-			self.terminal.setBackgroundColor(colors.black)
+	tab.onExit = tab.onExit or function(self, result, err, stack)
+		if not result and err and err ~= 'Terminated' then
+			self.terminal.setTextColor(colors.white)
+			self.terminal.setCursorBlink(false)
+			print('\nThe program terminated with an error.\n')
 			if tonumber(err) then
-				self.terminal.setTextColor(colors.orange)
-				print('Process exited with error code: ' .. err)
+				printError('Process exited with error code: ' .. err)
 			elseif err then
 				printError(tostring(err))
 			end
-			self.terminal.setTextColor(colors.white)
-			print('\nPress enter to close')
+			if type(stack) == 'table' and #stack > 0 then
+				local _, cy = self.terminal.getCursorPos()
+				local _, th = self.terminal.getSize()
+				self.terminal.setTextColor(colors.white)
+				if cy < th - 4 then
+					print('\nstack traceback:')
+					for _, v in ipairs(stack or { }) do
+						_, cy = self.terminal.getCursorPos()
+						if cy > th - 3 then
+							print(' ...')
+							break
+						end
+						print(v)
+					end
+				end
+			end
+			self.terminal.setTextColor(parentTerm.isColor() and colors.yellow or colors.white)
+			_G.write('\nPress enter to close')
 			self.isDead = true
 			self.hidden = false
 			redrawMenu()

sys/kernel.lua

@@ -110,7 +110,7 @@ end
 
 function Routine:run()
 	self.co = self.co or coroutine.create(function()
-		local result, err, fn
+		local result, err, fn, stack
 
 		if self.fn then
 			fn = self.fn
@@ -122,12 +122,12 @@ function Routine:run()
 		end
 
 		if fn then
-			result, err = trace(fn, table.unpack(self.args or { } ))
+			result, err, stack = trace(fn, table.unpack(self.args or { } ))
 		else
 			err = err or 'kernel: invalid routine'
 		end
 
-		pcall(self.onExit, self, result, err)
+		pcall(self.onExit, self, result, err, stack)
 		self:cleanup()
 
 		if not result then

sys/modules/opus/trace.lua

@@ -32,15 +32,28 @@ local function traceback(x)
 	end
 end
 
-local function trim_traceback(target)
-	local t = { }
+local function trim_traceback(stack)
+	local trace = { }
 	local filters = {
 		"%[C%]: in function 'xpcall'",
 		"(...tail calls...)",
 		"xpcall: $",
 		"trace.lua:%d+:",
+		"stack traceback:",
 	}
 
+	for line in stack:gmatch("([^\n]*)\n?") do table.insert(trace, line) end
+
+	local err = { }
+	while true do
+		local line = table.remove(trace, 1)
+		if not line or line == 'stack traceback:' then
+			break
+		end
+		table.insert(err, line)
+	end
+	err = table.concat(err, '\n')
+
 	local function matchesFilter(line)
 		for _, filter in pairs(filters) do
 			if line:match(filter) then
@@ -49,13 +62,15 @@ local function trim_traceback(target)
 		end
 	end
 
-	for line in target:gmatch("([^\n]*)\n?") do
+	local t = { }
+	for _, line in pairs(trace) do
 		if not matchesFilter(line) then
+			line = line:gsub("in function", "in")
 			table.insert(t, line)
 		end
 	end
 
-	return t
+	return err, t
 end
 
 return function (fn, ...)
@@ -66,29 +81,15 @@ return function (fn, ...)
 		return fn(table.unpack(args))
 	end, traceback))
 
-	local ok, err = res[1], res[2]
-
-	if not ok and err ~= nil then
-		local trace = trim_traceback(err)
-
-		err = { }
-		while true do
-			local line = table.remove(trace, 1)
-			if not line or line == 'stack traceback:' then
-				break
-			end
-			table.insert(err, line)
-		end
-		err = table.concat(err, '\n')
+	if not res[1] and res[2] ~= nil then
+		local err, trace = trim_traceback(res[2])
 
 		_G._syslog('\n' .. err .. '\n' .. 'stack traceback:')
 		for _, v in ipairs(trace) do
-			if v ~= 'stack traceback:' then
-				_G._syslog(v:gsub("in function", "in"))
-			end
+			_G._syslog(v)
 		end
 
-		return ok, err
+		return res[1], err, trace
 	end
 
 	return table.unpack(res, 1, res.n)