Function set_env

depends/lua/src/loadlib.c:634–643

** changes the environment variable of calling function */

** changes the environment variable of calling function
*/
static void set_env (lua_State *L) {
  lua_Debug ar;
  if (lua_getstack(L, 1, &ar) == 0 ||
      lua_getinfo(L, "f", &ar) == 0 ||  /* get calling function */
      lua_iscfunction(L, -1))
    luaL_error(L, "'module' not called from a Lua function");
  lua_pushvalue(L, -2);  /* copy new environment table to top */
  lua_setupvalue(L, -2, 1);
  lua_pop(L, 1);  /* remove function */
}


static void dooptions (lua_State *L, int n) {