[PATCH 3/4] dts: show help when DTS is ran without args

[Luca Vizzarro <luca.vizzarro@arm.com>]

This commit changes the default behaviour of DTS, making it so that the
user automatically sees the help and usage page when running it without
any arguments set. Instead of being welcomed by an error message.

Reviewed-by: Paul Szczepanek <paul.szczepanek@arm.com>
Signed-off-by: Luca Vizzarro <luca.vizzarro@arm.com>
---
 dts/framework/settings.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/dts/framework/settings.py b/dts/framework/settings.py
index acfe5cad44..5809fd4e91 100644
--- a/dts/framework/settings.py
+++ b/dts/framework/settings.py
@@ -71,6 +71,7 @@
 
 import argparse
 import os
+import sys
 from collections.abc import Callable, Iterable, Sequence
 from dataclasses import dataclass, field
 from pathlib import Path
@@ -315,6 +316,11 @@ def get_settings() -> Settings:
 
     The inputs are taken from the command line and from environment variables.
     """
+
+    if len(sys.argv) == 1:
+        _get_parser().print_help()
+        sys.exit(1)
+
     parsed_args = _get_parser().parse_args()
     return Settings(
         config_file_path=parsed_args.config_file,
-- 
2.34.1