41 lines
1014 B
Lua
41 lines
1014 B
Lua
--- Checks uses of undeclared global variables.
|
|
-- All global variables must be 'declared' through a regular
|
|
-- assignment (even assigning <code>nil</code> will do) in a top-level
|
|
-- chunk before being used anywhere or assigned to inside a function.
|
|
-- From Lua distribution (<code>etc/strict.lua</code>).
|
|
-- @class module
|
|
-- @name strict
|
|
|
|
local getinfo, error, rawset, rawget = debug.getinfo, error, rawset, rawget
|
|
|
|
local mt = getmetatable(_G)
|
|
if mt == nil then
|
|
mt = {}
|
|
setmetatable(_G, mt)
|
|
end
|
|
|
|
mt.__declared = {}
|
|
|
|
local function what ()
|
|
local d = getinfo(3, "S")
|
|
return d and d.what or "C"
|
|
end
|
|
|
|
mt.__newindex = function (t, n, v)
|
|
if not mt.__declared[n] then
|
|
local w = what()
|
|
if w ~= "main" and w ~= "C" then
|
|
error("assign to undeclared variable '"..n.."'", 2)
|
|
end
|
|
mt.__declared[n] = true
|
|
end
|
|
rawset(t, n, v)
|
|
end
|
|
|
|
mt.__index = function (t, n)
|
|
if not mt.__declared[n] and what() ~= "C" then
|
|
error("variable '"..n.."' is not declared", 2)
|
|
end
|
|
return rawget(t, n)
|
|
end
|