Can i load multiple libraries with ffi.load in LuaJIT?

Question

Is it possible to load more than one library at same time with LuaJIT's ffi.load?

Can something like this works?

local ffi = require("ffi")
local bor = require("bit").bor
ffi.cdef([[
   // C bindings from each library!
]])
return ffi.load(bor("lib1", "lib2", "lib3"))

Answer 1

You can't really import multiples libraries to a single userdata due to the way LuaJIT FFI library works. The only thing you can easily do is to call userdata getter in a protected call as LuaJIT FFI throw an error on undefined symbol, and loop each library you want to fetch.

local function get(t, k)
  return t[k]
end

local superlib = setmetatable({
  ffi.load "a",
  ffi.load "b",
  ffi.load "c"
}, {
  __index = function (self, k, v)
    for _,l in ipairs(self) do
      local status, val = pcall(get, l, k)
      if status then
        return val
      end
    end
  end
})