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@cloudwu /inject.lua
Last active Jul 24, 2017

What would you like to do?
Inject code with locals and upvalues
local FUNC_TEMP=[[
local $ARGS
return function(...)
$SOURCE
end,
function()
return {$LOCALS}
end
]]
local temp = {}
local function wrap_locals(source, level)
level = level + 3
local f = debug.getinfo(level,"f").func
if f == nil then
return
end
local uv = {}
local locals = {}
local uv_id = {}
local local_id = {}
local i = 1
while true do
local name, value = debug.getlocal(level, i)
if name == nil then
break
end
if name:byte() ~= 40 then -- '('
table.insert(uv, name)
table.insert(locals, ("[%d]=%s,"):format(i,name))
local_id[name] = value
end
i = i + 1
end
local i = 1
while true do
local name = debug.getupvalue(f, i)
if name == nil then
break
end
uv_id[name] = i
table.insert(uv, name)
i = i + 1
end
temp.ARGS = table.concat(uv, ",")
temp.SOURCE = source
temp.LOCALS = table.concat(locals)
local full_source = FUNC_TEMP:gsub("%$(%w+)",temp)
-- print(full_source)
local loader, err = load(full_source)
if loader == nil then
return nil, err
end
local func, update = loader()
-- join func's upvalues
local i = 1
while true do
local name = debug.getupvalue(func, i)
if name == nil then
break
end
local local_value = local_id[name]
if local_value then
debug.setupvalue(func, i, local_value)
end
local upvalue_id = uv_id[name]
if upvalue_id then
debug.upvaluejoin(func, i, f, upvalue_id)
end
i=i+1
end
local vararg, v = debug.getlocal(level, -1)
if vararg then
local vargs = { v }
local i = 2
while true do
local vararg,v = debug.getlocal(level, -i)
if vararg then
vargs[i] = v
else
break
end
i=i+1
end
return func, update, table.unpack(vargs)
else
return func, update
end
end
local function exec(level, func, update, ...)
if func == nil then
return update
end
local rets = table.pack(pcall(func, ...))
if rets[1] then
local needupdate = update()
for k,v in pairs(needupdate) do
debug.setlocal(level,k,v)
end
return table.unpack(rets, 2, rets.n)
else
return rets[2]
end
end
function run (source, level)
level = level or 0
return exec(level+2, wrap_locals(source, level))
end
----------------------------test-----------------
local uv = 2
function f(...)
local a,b = 1,uv
print("_ENV ===>", _ENV)
print("a,b ====>", a,b)
run[[
print "=== inject code ==="
print("\t_ENV ===>", _ENV)
print("\ta,b,uv ===>", a,b,uv)
print("\t... ", ...)
a,b = b,a
uv = 3
print "==== inject end ==="
]]
print("a,b ====>", a,b)
end
f("Hello","world")
print("uv=",uv)
--[[ output
_ENV ===> table: 0000000000266de0
a,b ====> 1 2
=== inject code ===
_ENV ===> table: 0000000000266de0
a,b,uv ===> 1 2 2
... Hello world
==== inject end ===
a,b ====> 2 1
uv= 3
]]
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