diff options
author | Mike Pall <mike> | 2009-12-08 19:46:35 +0100 |
---|---|---|
committer | Mike Pall <mike> | 2009-12-08 19:46:35 +0100 |
commit | 55b16959717084884fd4a0cbae6d19e3786c20c7 (patch) | |
tree | c8a07a43c13679751ed25a9d06796e9e7b2134a6 /etc | |
download | luajit2-55b16959717084884fd4a0cbae6d19e3786c20c7.tar.gz |
RELEASE LuaJIT-2.0.0-beta1v2.0.0-beta1
Diffstat (limited to 'etc')
-rw-r--r-- | etc/strict.lua | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/etc/strict.lua b/etc/strict.lua new file mode 100644 index 00000000..604619dd --- /dev/null +++ b/etc/strict.lua @@ -0,0 +1,41 @@ +-- +-- strict.lua +-- checks uses of undeclared global variables +-- All global variables must be 'declared' through a regular assignment +-- (even assigning nil will do) in a main chunk before being used +-- anywhere or assigned to inside a function. +-- + +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 + |