Function lookup_field

library/LuaTypes.cpp:419–426

* Resolve the field name in UPVAL_FIELDTABLE, die if not found. */

 * Resolve the field name in UPVAL_FIELDTABLE, die if not found.
 */
static void lookup_field(lua_State *state, int index, const char *mode)
{
    lua_pushvalue(state, index);
    lua_gettable(state, UPVAL_FIELDTABLE); // uses metatable with enum keys

    if (lua_isnil(state, -1))
        field_error(state, index, "not found", mode);
}

// Resolve the field in the metatable and return
static int get_metafield(lua_State *state)