Lua Notes

accessing hidden code

Consider this complete module, named hidden.nelua:

local function hidden() <nodce> print('how did you find me?') end

The <nodce> (no dead code elimination) keeps this function from getting optimized out entirely, but how can you use it without a global or the file's return having any reference to the function?

Option 1.) go through the C ABI

$ nelua -i 'require("hidden") ## cemit "hidden_hidden();"'
how did you find me?

With predictable names, this at least isn't crazy, right?

Option 2.) read the file with Lua

##[[
function expose(file)
  local f = io.open(file .. '.nelua', 'r')
  local src = f:read('*a')
  f:close()
  local ast, errlabel, errpos = aster.syntaxes.nelua.patt:match(src)
  assert(ast)
  assert(ast.tag == "Block")
  for i=1, #ast do inject_astnode(ast[i]) end
end
]]

## expose("hidden")
hidden()

contrast include files