mirror of
https://github.com/nmap/nmap.git
synced 2025-12-09 14:11:29 +00:00
86 lines
2.3 KiB
Lua
86 lines
2.3 KiB
Lua
---
|
|
-- Strict declared global library. Checks for undeclared global variables
|
|
-- during runtime execution.
|
|
--
|
|
-- This module places the <code>strict</code> function in the global
|
|
-- environment. The strict function allows a script to add runtime checking so
|
|
-- that undeclared globals cause an error to be raised. This is useful for
|
|
-- finding accidental use of globals when local was intended.
|
|
--
|
|
-- A global variable is considered "declared" if the script makes an assignment
|
|
-- to the global name (even <code>nil</code>) in the file scope.
|
|
--
|
|
-- @class module
|
|
-- @name strict
|
|
-- @copyright Copyright© Same as Nmap--See http://nmap.org/book/man-legal.html
|
|
|
|
local error = error;
|
|
local getfenv = getfenv;
|
|
local lmodule = module;
|
|
local rawset = rawset;
|
|
local rawget = rawget;
|
|
local setfenv = setfenv;
|
|
local type = type;
|
|
|
|
local getinfo = debug.getinfo;
|
|
|
|
local function what ()
|
|
local d = getinfo(3, "S");
|
|
return d and d.what or "C";
|
|
end
|
|
|
|
--- The strict function.
|
|
--
|
|
-- This function adds runtime checking to the global environment for use of
|
|
-- undeclared globals. A global is 'undeclared' if not assigned in the file
|
|
-- (script) scope previously. An error will be raised on use of an undeclared
|
|
-- global.
|
|
function strict ()
|
|
local _G = getfenv(2);
|
|
|
|
local mt = getmetatable(_G) or setmetatable(_G, {}) and getmetatable(_G);
|
|
local _newindex, _index = mt.__newindex, mt.__index;
|
|
|
|
mt.__declared = {};
|
|
|
|
function mt.__newindex (t, n, v)
|
|
if type(_newindex) == "function" then
|
|
_newindex(t, n, v); -- hook it
|
|
end
|
|
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
|
|
|
|
function mt.__index (t, n)
|
|
if type(_index) == "function" then
|
|
local v = _index(t, n); -- hook it
|
|
if v ~= nil then return v end
|
|
elseif _index ~= nil then
|
|
local v = _index[n];
|
|
if v ~= nil then return v end
|
|
end
|
|
if not mt.__declared[n] and what() ~= "C" then
|
|
error("variable '"..n.."' is not declared", 2);
|
|
end
|
|
return rawget(t, n);
|
|
end
|
|
end
|
|
|
|
local strict = strict;
|
|
|
|
function module (...)
|
|
local myenv = getfenv(1);
|
|
lmodule(...);
|
|
strict();
|
|
setfenv(2, getfenv(1));
|
|
setfenv(1, myenv);
|
|
end
|
|
|
|
return strict;
|