def builtin_adb_path():
        """
        Return built-in adb executable path

        Returns:
            adb executable path

        """
        system = platform.system()
        machine = platform.machine()
        adb_path = DEFAULT_ADB_PATH.get('{}-{}'.format(system, machine))
        if not adb_path:
            adb_path = DEFAULT_ADB_PATH.get(system)
        if not adb_path:
            raise RuntimeError("No adb executable supports this platform({}-{}).".format(system, machine))

        if system != "Windows":
            # chmod +x adb
            make_file_executable(adb_path)
        return adb_path

        Return built-in adb executable path

        Returns:
            adb executable path

        
airtest/core/android/adb.py