scripts: zephyr_flash_debug: add 'runners' command

from runner.core import ZephyrBinaryRunner

def print_runners_handler(args):

    for cls in ZephyrBinaryRunner.get_runners():

        print(cls.name())

def runner_handler(cls, args):

    runner = cls.create_from_args(args)

    # This relies on ZephyrBinaryRunner.add_parser() having command as

    # $ZEPHYR_BASE/.../SCRIPT.py [-v|--verbose] RUNNER [--runner-options]

    #

    # Note that --verbose comes *before* RUNNER, not after!

    #

    # Other commands (for now just the "runners" command, which prints

    # the available runners) are handled the same way:

    #

    # $ZEPHYR_BASE/.../SCRIPT.py runners

    top_parser = argparse.ArgumentParser()

    top_parser.add_argument('-v', '--verbose',

                            default=False, action='store_true',

                            help='If set, enable verbose output.')

    sub_parsers = top_parser.add_subparsers(dest='runner')

    sub_parsers = top_parser.add_subparsers(dest='top_command')

    # Handlers for each subcommand.

    handlers = {}

    # The 'runners' command just prints the runners. It takes no arguments.

    sub_parsers.add_parser('runners')

    handlers['runners'] = print_runners_handler

    # Add a sub-command for each runner. (It's a bit hackish for runners

    # to know about argparse, but it's good enough for now.)

    handlers = {}

    for cls in ZephyrBinaryRunner.get_runners():

        if cls.name() in handlers:

            print('Runner {} name is already a sub-command'.format(cls.name()),

            print('Runner {} name is already a top-level command'.format(

                      cls.name()),

                  file=sys.sterr)

            sys.exit(1)

        sub_parser = sub_parsers.add_parser(cls.name())

        handlers[cls.name()] = functools.partial(runner_handler, cls)

    args = top_parser.parse_args()

    if args.runner is None:

        runners = ', '.join(handlers.keys())

        print('Missing runner; choices: {}'.format(runners), file=sys.stderr)

    if args.top_command is None:

        choices = ', '.join(handlers.keys())

        print('Missing command or runner; choices: {}'.format(choices),

              file=sys.stderr)

        sys.exit(1)

    try:

        handlers[args.runner](args)

        handlers[args.top_command](args)

    except Exception as e:

        print('Error: {}'.format(e), file=sys.stderr)

        raise