kunit: tool: more descriptive metavars/--help output

Before, our help output contained lines like
  --kconfig_add KCONFIG_ADD
  --qemu_config qemu_config
  --jobs jobs

They're not very helpful.

The former kind come from the automatic 'metavar' we get from argparse,
the uppercase version of the flag name.
The latter are where we manually specified metavar as the flag name.

After:
  --build_dir DIR
  --make_options X=Y
  --kunitconfig PATH
  --kconfig_add CONFIG_X=Y
  --arch ARCH
  --cross_compile PREFIX
  --qemu_config FILE
  --jobs N
  --timeout SECONDS
  --raw_output [{all,kunit}]
  --json [FILE]

This patch tries to make the code more clear by specifying the _type_ of
input we expect, e.g. --build_dir is a DIR, --qemu_config is a FILE.
I also switched it to uppercase since it looked more clearly like
placeholder text that way.

This patch also changes --raw_output to specify `choices` to make it
more clear what the options are, and this way argparse can validate it
for us, as shown by the added test case.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/kunit/kunit.py

@@ -206,8 +206,6 @@ def parse_tests(request: KunitParseRequest, metadata: kunit_json.Metadata, input
 			pass
 		elif request.raw_output == 'kunit':
 			output = kunit_parser.extract_tap_lines(output)
-		else:
-			print(f'Unknown --raw_output option "{request.raw_output}"', file=sys.stderr)
 		for line in output:
 			print(line.rstrip())
 
@@ -284,30 +282,30 @@ def add_common_opts(parser) -> None:
 	parser.add_argument('--build_dir',
 			    help='As in the make command, it specifies the build '
 			    'directory.',
-			    type=str, default='.kunit', metavar='build_dir')
+			    type=str, default='.kunit', metavar='DIR')
 	parser.add_argument('--make_options',
 			    help='X=Y make option, can be repeated.',
-			    action='append')
+			    action='append', metavar='X=Y')
 	parser.add_argument('--alltests',
 			    help='Run all KUnit tests through allyesconfig',
 			    action='store_true')
 	parser.add_argument('--kunitconfig',
 			     help='Path to Kconfig fragment that enables KUnit tests.'
 			     ' If given a directory, (e.g. lib/kunit), "/.kunitconfig" '
 			     'will get  automatically appended.',
-			     metavar='kunitconfig')
+			     metavar='PATH')
 	parser.add_argument('--kconfig_add',
 			     help='Additional Kconfig options to append to the '
 			     '.kunitconfig, e.g. CONFIG_KASAN=y. Can be repeated.',
-			    action='append')
+			    action='append', metavar='CONFIG_X=Y')
 
 	parser.add_argument('--arch',
 			    help=('Specifies the architecture to run tests under. '
 				  'The architecture specified here must match the '
 				  'string passed to the ARCH make param, '
 				  'e.g. i386, x86_64, arm, um, etc. Non-UML '
 				  'architectures run on QEMU.'),
-			    type=str, default='um', metavar='arch')
+			    type=str, default='um', metavar='ARCH')
 
 	parser.add_argument('--cross_compile',
 			    help=('Sets make\'s CROSS_COMPILE variable; it should '
@@ -319,18 +317,18 @@ def add_common_opts(parser) -> None:
 				  'if you have downloaded the microblaze toolchain '
 				  'from the 0-day website to a directory in your '
 				  'home directory called `toolchains`).'),
-			    metavar='cross_compile')
+			    metavar='PREFIX')
 
 	parser.add_argument('--qemu_config',
 			    help=('Takes a path to a path to a file containing '
 				  'a QemuArchParams object.'),
-			    type=str, metavar='qemu_config')
+			    type=str, metavar='FILE')
 
 def add_build_opts(parser) -> None:
 	parser.add_argument('--jobs',
 			    help='As in the make command, "Specifies  the number of '
 			    'jobs (commands) to run simultaneously."',
-			    type=int, default=get_default_jobs(), metavar='jobs')
+			    type=int, default=get_default_jobs(), metavar='N')
 
 def add_exec_opts(parser) -> None:
 	parser.add_argument('--timeout',
@@ -339,7 +337,7 @@ def add_exec_opts(parser) -> None:
 			    'tests.',
 			    type=int,
 			    default=300,
-			    metavar='timeout')
+			    metavar='SECONDS')
 	parser.add_argument('filter_glob',
 			    help='Filter which KUnit test suites/tests run at '
 			    'boot-time, e.g. list* or list*.*del_test',
@@ -349,7 +347,7 @@ def add_exec_opts(parser) -> None:
 			    metavar='filter_glob')
 	parser.add_argument('--kernel_args',
 			    help='Kernel command-line parameters. Maybe be repeated',
-			     action='append')
+			     action='append', metavar='')
 	parser.add_argument('--run_isolated', help='If set, boot the kernel for each '
 			    'individual suite/test. This is can be useful for debugging '
 			    'a non-hermetic test, one that might pass/fail based on '
@@ -360,13 +358,13 @@ def add_exec_opts(parser) -> None:
 def add_parse_opts(parser) -> None:
 	parser.add_argument('--raw_output', help='If set don\'t format output from kernel. '
 			    'If set to --raw_output=kunit, filters to just KUnit output.',
-			    type=str, nargs='?', const='all', default=None)
+			     type=str, nargs='?', const='all', default=None, choices=['all', 'kunit'])
 	parser.add_argument('--json',
 			    nargs='?',
 			    help='Stores test results in a JSON, and either '
 			    'prints to stdout or saves to file if a '
 			    'filename is specified',
-			    type=str, const='stdout', default=None)
+			    type=str, const='stdout', default=None, metavar='FILE')
 
 def main(argv, linux=None):
 	parser = argparse.ArgumentParser(

tools/testing/kunit/kunit_tool_test.py

@@ -593,6 +593,11 @@ def test_run_raw_output_kunit(self):
 			self.assertNotEqual(call, mock.call(StrContains('Testing complete.')))
 			self.assertNotEqual(call, mock.call(StrContains(' 0 tests run')))
 
+	def test_run_raw_output_invalid(self):
+		self.linux_source_mock.run_kernel = mock.Mock(return_value=[])
+		with self.assertRaises(SystemExit) as e:
+			kunit.main(['run', '--raw_output=invalid'], self.linux_source_mock)
+
 	def test_run_raw_output_does_not_take_positional_args(self):
 		# --raw_output is a string flag, but we don't want it to consume
 		# any positional arguments, only ones after an '='