areusch review: As per the API, options shouldn't always be required

As an API-level concept, it shouldn't always be required to specify an
option. This commit changes TVMC behavior to only make options mandatory
to be specified when one or more options returned by the API are
required.

This also fixes some nits in some docstrings.

python/tvm/driver/tvmc/common.py

@@ -641,7 +641,7 @@ def get_options(options):
     Returns
     -------
     opts: dict
-        dict indexed by option name of option name and associated value.
+        dict indexed by option names and associated values.
     """
 
     opts = {}
@@ -714,6 +714,40 @@ def check_options_choices(options, valid_options):
         if option in valid_options_choices:
             if options[option] not in valid_options_choices[option]:
                 raise TVMCException(
-                    f"Choice '{options[option]} for option '{option}' is invalid. "
+                    f"Choice '{options[option]}' for option '{option}' is invalid. "
                     "Use --list-options to see all available choices for that option."
                 )
+
+def get_and_check_options(passed_options, valid_options):
+    """Get options and check if they are valid.  If choices exist for them, check values against it.
+
+    Parameters
+    ----------
+    passed_options: list of str
+        list of strings in the "key=value" form as captured by argparse.
+
+    valid_option: list
+        list with all options available for a given API method / project as returned by
+        get_project_options().
+
+    Returns
+    -------
+    opts: dict
+        dict indexed by option names and associated values.
+
+    Or None if passed_options is None.
+
+    """
+
+    if passed_options is None:
+        # No options to check
+        return None
+
+    # From a list of k=v strings, make a dict options[k]=v
+    opts = get_options(passed_options)
+    # Check if passed options are valid
+    check_options(opts, valid_options)
+    # Check (when a list of choices exists) if the passed values are valid
+    check_options_choices(opts, valid_options)
+
+    return opts

python/tvm/driver/tvmc/micro.py

@@ -30,9 +30,7 @@
 from .common import (
     TVMCException,
     get_project_options,
-    get_options,
-    check_options,
-    check_options_choices,
+    get_and_check_options,
 )
 
 
@@ -204,9 +202,8 @@ def _add_parser(parser, platform):
     help_text_by_option = [opt["help_text"] for opt in options_by_method[method]]
     help_text = "\n\n".join(help_text_by_option) + "\n\n"
 
-    # TODO(gromero): Experiment with required=required below
     parser_by_subcmd_n_platform.add_argument(
-        "--project-option", required=True, metavar="OPTION=VALUE", nargs=nargs, help=help_text
+        "--project-option", required=required, metavar="OPTION=VALUE", nargs=nargs, help=help_text
     )
 
     parser_by_subcmd_n_platform.add_argument(
@@ -239,9 +236,7 @@ def create_project_handler(args):
     if not os.path.exists(mlf_path):
         raise TVMCException(f"MLF file {mlf_path} does not exist!")
 
-    options = get_options(args.project_option)
-    check_options(options, args.valid_options)
-    check_options_choices(options, args.valid_options)
+    options = get_and_check_options(args.project_option, args.valid_options)
 
     try:
         project.generate_project_from_mlf(template_dir, project_dir, mlf_path, options)
@@ -267,9 +262,7 @@ def build_handler(args):
 
     project_dir = args.project_dir
 
-    options = get_options(args.project_option)
-    check_options(options, args.valid_options)
-    check_options_choices(options, args.valid_options)
+    options = get_and_check_options(args.project_option, args.valid_options)
 
     try:
         prj = project.GeneratedProject.from_directory(project_dir, options=options)
@@ -286,9 +279,7 @@ def flash_handler(args):
 
     project_dir = args.project_dir
 
-    options = get_options(args.project_option)
-    check_options(options, args.valid_options)
-    check_options_choices(options, args.valid_options)
+    options = get_and_check_options(args.project_option, args.valid_options)
 
     try:
         prj = project.GeneratedProject.from_directory(project_dir, options=options)

python/tvm/driver/tvmc/runner.py

@@ -42,9 +42,7 @@
     TVMCException,
     TVMCSilentArgumentParser,
     get_project_options,
-    get_options,
-    check_options,
-    check_options_choices,
+    get_and_check_options,
 )
 from .main import register_parser
 from .model import TVMCPackage, TVMCResult
@@ -153,7 +151,7 @@ def add_run_parser(subparsers, main_parser):
     help_text_by_option = [opt["help_text"] for opt in options_by_method["open_transport"]]
     help_text = "\n\n".join(help_text_by_option) + "\n\n"
     parser.add_argument(
-        "--project-option", required=True, metavar="OPTION=VALUE", nargs=nargs, help=help_text
+        "--project-option", required=required, metavar="OPTION=VALUE", nargs=nargs, help=help_text
     )
 
 
@@ -192,10 +190,7 @@ def drive_run(args):
             raise TVMCException("--profile is not supported for micro targets.")
 
         # Get and check options for micro targets.
-
-        options = get_options(args.project_option)
-        check_options(options, args.valid_options)
-        check_options_choices(options, args.valid_options)
+        options = get_and_check_options(args.project_option, args.valid_options)
 
     try:
         tvmc_package = TVMCPackage(package_path=path)