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119 lines
2.4 KiB
Lua

local si = require "snax.interface"
local function envid(f)
local i = 1
while true do
local name, value = debug.getupvalue(f, i)
if name == nil then
return
end
if name == "_ENV" then
return debug.upvalueid(f, i)
end
i = i + 1
end
end
local function collect_uv(f , uv, env)
local i = 1
while true do
local name, value = debug.getupvalue(f, i)
if name == nil then
break
end
local id = debug.upvalueid(f, i)
if uv[name] then
assert(uv[name].id == id, string.format("ambiguity local value %s", name))
else
uv[name] = { func = f, index = i, id = id }
if type(value) == "function" then
if envid(value) == env then
collect_uv(value, uv, env)
end
end
end
i = i + 1
end
end
local function collect_all_uv(funcs)
local global = {}
for _, v in pairs(funcs) do
if v[4] then
collect_uv(v[4], global, envid(v[4]))
end
end
if not global["_ENV"] then
global["_ENV"] = {func = collect_uv, index = 1}
end
return global
end
local function loader(source)
return function (path, name, G)
return load(source, "=patch", "bt", G)
end
end
local function find_func(funcs, group , name)
for _, desc in pairs(funcs) do
local _, g, n = table.unpack(desc)
if group == g and name == n then
return desc
end
end
end
local dummy_env = {}
for k,v in pairs(_ENV) do dummy_env[k] = v end
local function _patch(global, f)
local i = 1
while true do
local name, value = debug.getupvalue(f, i)
if name == nil then
break
elseif value == nil or value == dummy_env then
local old_uv = global[name]
if old_uv then
debug.upvaluejoin(f, i, old_uv.func, old_uv.index)
end
else
if type(value) == "function" then
_patch(global, value)
end
end
i = i + 1
end
end
local function patch_func(funcs, global, group, name, f)
local desc = assert(find_func(funcs, group, name) , string.format("Patch mismatch %s.%s", group, name))
_patch(global, f)
desc[4] = f
end
local function inject(funcs, source, ...)
local patch = si("patch", dummy_env, loader(source))
local global = collect_all_uv(funcs)
for _, v in pairs(patch) do
local _, group, name, f = table.unpack(v)
if f then
patch_func(funcs, global, group, name, f)
end
end
local hf = find_func(patch, "system", "hotfix")
if hf and hf[4] then
return hf[4](...)
end
end
return function (funcs, source, ...)
return pcall(inject, funcs, source, ...)
end