3 -- checks uses of undeclared global variables
4 -- All global variables must be 'declared' through a regular assignment
5 -- (even assigning nil will do) in a main chunk before being used
6 -- anywhere or assigned to inside a function.
9 local getinfo, error, rawset, rawget = debug.getinfo, error, rawset, rawget
11 local mt = getmetatable(_G)
20 local function what ()
21 local d = getinfo(3, "S")
22 return d and d.what or "C"
25 mt.__newindex = function (t, n, v)
26 if __strict and not mt.__declared[n] then
28 if w ~= "main" and w ~= "C" then
29 error("assign to undeclared variable '"..n.."'", 2)
31 mt.__declared[n] = true
36 mt.__index = function (t, n)
37 if __strict and not mt.__declared[n] and what() ~= "C" then
38 error("variable '"..n.."' is not declared", 2)
44 for _, v in ipairs{...} do mt.__declared[v] = true end