Merge pull request #2319 from RossBrunton/ross/cts_exe

[NFC] Improve documentation of cts_exe.py

Author: RossBrunton

scripts/core/CONTRIB.rst

@@ -401,6 +401,13 @@ failure) for the given adapter. However this can be disabled by prepending
 ``{{OPT}}`` to the match line. This can be used if the test is flaky or
 depends on a particular environment.
 
+This matching is done via ``test/conformance/cts_exe.py``, which is designed to be
+called from ctest. However, it can be run manually as follows:
+
+.. code-block:: console
+
+    test/conformance/cts_exe.py --test_command build/bin/test-adapter --failslist test/conformance/adapter/adapter_adapter_mytarget.match -- --backend=BACKEND
+
 Experimental Features
 =====================
 

test/conformance/cts_exe.py

@@ -122,6 +122,10 @@ def _run_cmd(cmd, comment, filter):
     parser.add_argument("rest", nargs=argparse.REMAINDER)
     args = parser.parse_args()
 
+    if args.test_command is None or args.failslist is None:
+        print("Usage: cts_exe.py --test_command (test binary) --failslist (match file) -- (test arguments)")
+        sys.exit(1)
+
     base_invocation = [args.test_command] + args.rest
 
     if os.environ.get("GTEST_OUTPUT") is not None: