build/fbcode_builder/parse_args.py

#!/usr/bin/env python
# Copyright (c) Facebook, Inc. and its affiliates.

"Argument parsing logic shared by all fbcode_builder CLI tools."

import argparse
import logging

from shell_quoting import raw_shell, ShellQuoted


def parse_args_to_fbcode_builder_opts(add_args_fn, top_level_opts, opts, help):
    """

    Provides some standard arguments: --debug, --option, --shell-quoted-option

    Then, calls `add_args_fn(parser)` to add application-specific arguments.

    `opts` are first used as defaults for the various command-line
    arguments.  Then, the parsed arguments are mapped back into `opts`,
    which then become the values for `FBCodeBuilder.option()`, to be used
    both by the builder and by `get_steps_fn()`.

    `help` is printed in response to the `--help` argument.

    """
    top_level_opts = set(top_level_opts)

    parser = argparse.ArgumentParser(
        description=help, formatter_class=argparse.RawDescriptionHelpFormatter
    )

    add_args_fn(parser)

    parser.add_argument(
        "--option",
        nargs=2,
        metavar=("KEY", "VALUE"),
        action="append",
        default=[
            (k, v)
            for k, v in opts.items()
            if k not in top_level_opts and not isinstance(v, ShellQuoted)
        ],
        help="Set project-specific options. These are assumed to be raw "
        "strings, to be shell-escaped as needed. Default: %(default)s.",
    )
    parser.add_argument(
        "--shell-quoted-option",
        nargs=2,
        metavar=("KEY", "VALUE"),
        action="append",
        default=[
            (k, raw_shell(v))
            for k, v in opts.items()
            if k not in top_level_opts and isinstance(v, ShellQuoted)
        ],
        help="Set project-specific options. These are assumed to be shell-"
        "quoted, and may be used in commands as-is. Default: %(default)s.",
    )

    parser.add_argument("--debug", action="store_true", help="Log more")
    args = parser.parse_args()

    logging.basicConfig(
        level=logging.DEBUG if args.debug else logging.INFO,
        format="%(levelname)s: %(message)s",
    )

    # Map command-line args back into opts.
    logging.debug("opts before command-line arguments: {0}".format(opts))

    new_opts = {}
    for key in top_level_opts:
        val = getattr(args, key)
        # Allow clients to unset a default by passing a value of None in opts
        if val is not None:
            new_opts[key] = val
    for key, val in args.option:
        new_opts[key] = val
    for key, val in args.shell_quoted_option:
        new_opts[key] = ShellQuoted(val)

    logging.debug("opts after command-line arguments: {0}".format(new_opts))

    return new_opts