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.
8 -- From Lua distribution (etc/strict.lua)
11 local getinfo, error, rawset, rawget = debug.getinfo, error, rawset, rawget
13 local mt = getmetatable(_G)
21 local function what ()
22 local d = getinfo(3, "S")
23 return d and d.what or "C"
26 mt.__newindex = function (t, n, v)
27 if not mt.__declared[n] then
29 if w ~= "main" and w ~= "C" then
30 print("assign to undeclared variable '"..n.."'")
32 mt.__declared[n] = true
37 mt.__index = function (t, n)
38 if not mt.__declared[n] and what() ~= "C" then
39 print("variable '"..n.."' is not declared")