[BE] Prefer dash over underscore in command-line options (#94505)

Preferring dash over underscore in command-line options. Add `--command-arg-name` to the argument parser. The old arguments with underscores `--command_arg_name` are kept for backward compatibility.

Both dashes and underscores are used in the PyTorch codebase. Some argument parsers only have dashes or only have underscores in arguments. For example, the `torchrun` utility for distributed training only accepts underscore arguments (e.g., `--master_port`). The dashes are more common in other command-line tools. And it looks to be the default choice in the Python standard library:

`argparse.BooleanOptionalAction`: 4a9dff0e5a/Lib/argparse.py (L893-L895)

```python
class BooleanOptionalAction(Action):
    def __init__(...):
            if option_string.startswith('--'):
                option_string = '--no-' + option_string[2:]
                _option_strings.append(option_string)
```

It adds `--no-argname`, not `--no_argname`. Also typing `_` need to press the shift or the caps-lock key than `-`.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/94505
Approved by: https://github.com/ezyang, https://github.com/seemethere

tools/jit/gen_unboxing.py

@@ -204,7 +204,11 @@ def main(args: List[str]) -> None:
         default="aten/src/ATen",
     )
     parser.add_argument(
-        "-d", "--install_dir", help="output directory", default="build/aten/src/ATen"
+        "-d",
+        "--install-dir",
+        "--install_dir",
+        help="output directory",
+        default="build/aten/src/ATen",
     )
     parser.add_argument(
         "-o",
@@ -217,6 +221,7 @@ def main(args: List[str]) -> None:
         help="run without writing any files (still updates outputs)",
     )
     parser.add_argument(
+        "--op-selection-yaml-path",
         "--op_selection_yaml_path",
         help="Provide a path to the operator selection (for custom build) YAML "
         "that contains the information about the set of selected operators "
@@ -225,6 +230,7 @@ def main(args: List[str]) -> None:
         "The operator names also contain the namespace prefix (e.g. aten::)",
     )
     parser.add_argument(
+        "--op-registration-allowlist",
         "--op_registration_allowlist",
         nargs="*",
         help="filter op registrations by the allowlist (if set); "
@@ -232,6 +238,7 @@ def main(args: List[str]) -> None:
         "e.g.: aten::empty aten::conv2d ...",
     )
     parser.add_argument(
+        "--TEST-ONLY-op-registration-allowlist-yaml-path",
         "--TEST_ONLY_op_registration_allowlist_yaml_path",
         help="Provide a path to the operator selection (for custom build) YAML "
         "which contains a list of operators. It is to serve testing purpose and "

tools/jit/test/test_gen_unboxing.py

@@ -17,7 +17,7 @@ class TestGenUnboxing(unittest.TestCase):
         mock_parse_native_yaml: NonCallableMock,
         mock_get_custom_build_selector: NonCallableMock,
     ) -> None:
-        args = ["--op_registration_allowlist=op1", "--op_selection_yaml_path=path2"]
+        args = ["--op-registration-allowlist=op1", "--op-selection-yaml-path=path2"]
         gen_unboxing.main(args)
         mock_get_custom_build_selector.assert_called_once_with(["op1"], "path2")
 
@@ -32,8 +32,8 @@ class TestGenUnboxing(unittest.TestCase):
         temp_file.write(b"- aten::add.Tensor")
         temp_file.seek(0)
         args = [
-            f"--TEST_ONLY_op_registration_allowlist_yaml_path={temp_file.name}",
-            "--op_selection_yaml_path=path2",
+            f"--TEST-ONLY-op-registration-allowlist-yaml-path={temp_file.name}",
+            "--op-selection-yaml-path=path2",
         ]
         gen_unboxing.main(args)
         mock_get_custom_build_selector.assert_called_once_with(
@@ -52,9 +52,9 @@ class TestGenUnboxing(unittest.TestCase):
         temp_file.write(b"- aten::add.Tensor")
         temp_file.seek(0)
         args = [
-            "--op_registration_allowlist=op1",
-            "--TEST_ONLY_op_registration_allowlist_yaml_path={temp_file.name}",
-            "--op_selection_yaml_path=path2",
+            "--op-registration-allowlist=op1",
+            "--TEST-ONLY-op-registration-allowlist-yaml-path={temp_file.name}",
+            "--op-selection-yaml-path=path2",
         ]
         gen_unboxing.main(args)
         mock_get_custom_build_selector.assert_called_once_with(["op1"], "path2")