StackTracePlus

StackTracePlus provides enhaced stack traces for Lua.

StackTracePlus can be used as a replacement for debug.traceback. It gives detailed information about locals, tries to guess function names when they're not available, etc, so, instead of

lua5.1.exe: D:\trunk_git\sources\stacktraceplus\test\test.lua:10: attempt to concatenate a nil value
stack traceback:
	D:\trunk_git\sources\stacktraceplus\test\test.lua:10: in function <D:\trunk_git\sources\stacktraceplus\test\test.lua:7>
	(tail call): ?
	D:\trunk_git\sources\stacktraceplus\test\test.lua:15: in main chunk
	[C]: ?

you'll get

lua5.1.exe: D:\trunk_git\sources\stacktraceplus\test\test.lua:10: attempt to concatenate a nil value
Stack Traceback
===============
(2)  C function 'function: 00A8F418'
(3) Lua function 'g' at file 'D:\trunk_git\sources\stacktraceplus\test\test.lua:10' (best guess)
	Local variables:
	 fun = table module
	 str = string: "hey"
	 tb = table: 027DCBE0  {dummy:1, blah:true, foo:bar}
	 (*temporary) = nil
	 (*temporary) = string: "text"
	 (*temporary) = string: "attempt to concatenate a nil value"
(4) tail call
(5) main chunk of file 'D:\trunk_git\sources\stacktraceplus\test\test.lua' at line 15
(6)  C function 'function: 002CA480'

Usage

StackTracePlus can be used as a replacement for debug.traceback, as an xpcall error handler or even from C code.

local STP = require "StackTracePlus"

debug.traceback = STP.stacktrace
function test()
	local s = "this is a string"
	local n = 42
	local t = { foo = "bar" }
	local co = coroutine
	local cr = coroutine.create
	
	error("an error")
end
test()

That script will output:

lua5.1: example.lua:11: an error
Stack Traceback
===============
(2)  C function 'function: 006B5758'
(3) global C function 'error'
(4) Lua global 'test' at file 'example.lua:11'
        Local variables:
         s = string: "this is a string"
         n = number: 42
         t = table: 006E5220  {foo:bar}
         co = coroutine table
         cr = C function: 003C7080
(5) main chunk of file 'example.lua' at line 14
(6)  C function 'function: 00637B30'

StackTracePlus is aware of the usual Lua libraries, like coroutine, table, string, io, etc and functions like print, pcall, assert, and so on.

You can also make STP aware of your own tables and functions by calling add_known_function and add_known_table.

local STP = require "StackTracePlus"

debug.traceback = STP.stacktrace
local my_table = {
	f = function() end
}
function my_function()
end

function test(data, func)
	local s = "this is a string"
	
	error("an error")
end

STP.add_known_table(my_table, "A description for my_table")
STP.add_known_function(my_function, "A description for my_function")

test( my_table, my_function )

Will output:

lua5.1: ..\test\example2.lua:13: an error
Stack Traceback
===============
(2)  C function 'function: 0073AAA8'
(3) global C function 'error'
(4) Lua global 'test' at file '..\test\example2.lua:13'
        Local variables:
         data = A description for my_table
         func = Lua function 'A description for my_function' (defined at line 7 of chunk ..\test\example2.lua)
         s = string: "this is a string"
(5) main chunk of file '..\test\example2.lua' at line 19
(6)  C function 'function: 00317B30'