clean: Move argument parsing to separate file

stm32loader/args.py

@@ -0,0 +1,223 @@
+"""Parse command-line arguments."""
+
+import argparse
+import atexit
+import copy
+import os
+import sys
+
+from stm32loader import __version__
+
+
+DEFAULT_VERBOSITY = 5
+
+
+class HelpFormatter(argparse.RawDescriptionHelpFormatter, argparse.ArgumentDefaultsHelpFormatter):
+    """Custom help formatter -- don't print confusing default values."""
+
+    def _get_help_string(self, action):
+        action = copy.copy(action)
+        # Don't show "(default: None)" for arguments without defaults,
+        # or "(default: False)" for boolean flags, and hide the
+        # (default: 5) from --verbose's help because it's confusing.
+        if not action.default or action.dest == "verbosity":
+            action.default = argparse.SUPPRESS
+        return super()._get_help_string(action)
+
+    def _format_actions_usage(self, actions, groups):
+        # Always treat -p/--port as required. See the note about the
+        # argparse hack in Stm32Loader.parse_arguments for why.
+        def tweak_action(action):
+            action = copy.copy(action)
+            if action.dest == "port":
+                action.required = True
+            return action
+
+        return super()._format_actions_usage(map(tweak_action, actions), groups)
+
+
+def _auto_int(x):
+    """Convert to int with automatic base detection."""
+    # This supports 0x10 == 16 and 10 == 10
+    return int(x, 0)
+
+
+def parse_arguments(arguments):
+    """Parse the given command-line arguments and return the configuration."""
+
+    parser = argparse.ArgumentParser(
+        prog="stm32loader",
+        description="Flash firmware to STM32 microcontrollers.",
+        epilog="\n".join(
+            [
+                "examples:",
+                "  %(prog)s -p COM7 -f F1",
+                "  %(prog)s -e -w -v example/main.bin",
+            ]
+        ),
+        formatter_class=HelpFormatter,
+    )
+
+    data_file_arg = parser.add_argument(
+        "data_file",
+        metavar="FILE.BIN",
+        type=str,
+        nargs="?",
+        help="File to read from or store to flash.",
+    )
+
+    parser.add_argument(
+        "-e",
+        "--erase",
+        action="store_true",
+        help="Erase (note: this is required on previously written memory).",
+    )
+
+    parser.add_argument(
+        "-u", "--unprotect", action="store_true", help="Unprotect in case erase fails."
+    )
+
+    parser.add_argument("-w", "--write", action="store_true", help="Write file content to flash.")
+
+    parser.add_argument(
+        "-v",
+        "--verify",
+        action="store_true",
+        help="Verify flash content versus local file (recommended).",
+    )
+
+    parser.add_argument(
+        "-r", "--read", action="store_true", help="Read from flash and store in local file."
+    )
+
+    length_arg = parser.add_argument(
+        "-l", "--length", action="store", type=_auto_int, help="Length of read."
+    )
+
+    default_port = os.environ.get("STM32LOADER_SERIAL_PORT")
+    port_arg = parser.add_argument(
+        "-p",
+        "--port",
+        action="store",
+        type=str,  # morally required=True
+        default=default_port,
+        help=("Serial port" + ("." if default_port else " (default: $STM32LOADER_SERIAL_PORT).")),
+    )
+
+    parser.add_argument(
+        "-b", "--baud", action="store", type=int, default=115200, help="Baudrate."
+    )
+
+    address_arg = parser.add_argument(
+        "-a",
+        "--address",
+        action="store",
+        type=_auto_int,
+        default=0x08000000,
+        help="Target address.",
+    )
+
+    parser.add_argument(
+        "-g",
+        "--go-address",
+        action="store",
+        type=_auto_int,
+        metavar="ADDRESS",
+        help="Start executing from address (0x08000000, usually).",
+    )
+
+    default_family = os.environ.get("STM32LOADER_FAMILY")
+    parser.add_argument(
+        "-f",
+        "--family",
+        action="store",
+        type=str,
+        default=default_family,
+        help=(
+            "Device family to read out device UID and flash size; "
+            "e.g F1 for STM32F1xx. Possible values: F0, F1, F3, F4, F7, H7, L4, L0, G0, NRG."
+            + ("." if default_family else " (default: $STM32LOADER_FAMILY).")
+        ),
+    )
+
+    parser.add_argument(
+        "-V",
+        "--verbose",
+        dest="verbosity",
+        action="store_const",
+        const=10,
+        default=DEFAULT_VERBOSITY,
+        help="Verbose mode.",
+    )
+
+    parser.add_argument(
+        "-q", "--quiet", dest="verbosity", action="store_const", const=0, help="Quiet mode."
+    )
+
+    parser.add_argument(
+        "-s",
+        "--swap-rts-dtr",
+        action="store_true",
+        help="Swap RTS and DTR: use RTS for reset and DTR for boot0.",
+    )
+
+    parser.add_argument(
+        "-R", "--reset-active-high", action="store_true", help="Make RESET active high."
+    )
+
+    parser.add_argument(
+        "-B", "--boot0-active-low", action="store_true", help="Make BOOT0 active low."
+    )
+
+    parser.add_argument(
+        "-n", "--no-progress", action="store_true", help="Don't show progress bar."
+    )
+
+    parser.add_argument(
+        "-P",
+        "--parity",
+        action="store",
+        type=str,
+        default="even",
+        choices=["event", "none"],
+        help='Parity: "even" for STM32, "none" for BlueNRG.',
+    )
+
+    parser.add_argument("--version", action="version", version=__version__)
+
+    # Hack: We want certain arguments to be required when one
+    # of -rwv is specified, but argparse doesn't support
+    # conditional dependencies like that. Instead, we add the
+    # requirements post-facto and re-run the parse to get the error
+    # messages we want. A better solution would be to use
+    # subcommands instead of options for -rwv, but this would
+    # change the command-line interface.
+    #
+    # We also use this gross hack to provide a hint about the
+    # STM32LOADER_SERIAL_PORT environment variable when -p
+    # is omitted; we only set --port as required after the first
+    # parse so we can hook in a custom error message.
+
+    configuration = parser.parse_args(arguments)
+
+    if not configuration.port:
+        port_arg.required = True
+        atexit.register(
+            lambda: print(
+                "{}: note: you can also set the environment "
+                "variable STM32LOADER_SERIAL_PORT".format(parser.prog),
+                file=sys.stderr,
+            )
+        )
+
+    if configuration.read or configuration.write or configuration.verify:
+        data_file_arg.nargs = None
+        data_file_arg.required = True
+
+    if configuration.read:
+        length_arg.required = True
+        address_arg.required = True
+
+    parser.parse_args(arguments)
+
+    return configuration