kunit: tool: make build subcommand also reconfigure if needed

If I created a kunitconfig file that was incomplete, then
$ ./tools/testing/kunit/kunit.py build --kunitconfig=my_kunitconfig
would silently drop all the options with unmet dependencies!

This is because it doesn't do the config check that `kunit.py config`
does.

So if I want to safely build a kernel for testing, I have to do
$ ./tools/testing/kunit/kunit.py config <flags>
$ ./tools/testing/kunit/kunit.py build <flags, again>

It seems unlikely that any user of kunit.py would want the current
`build` semantics.
So make it effectively do `kunit.py config` + `kunit.py build`.

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

tools/testing/kunit/kunit.py

@@ -110,6 +110,14 @@ def build_tests(linux: kunit_kernel.LinuxSourceTree,
 			   'built kernel successfully',
 			   build_end - build_start)
 
+def config_and_build_tests(linux: kunit_kernel.LinuxSourceTree,
+			   request: KunitBuildRequest) -> KunitResult:
+	config_result = config_tests(linux, request)
+	if config_result.status != KunitStatus.SUCCESS:
+		return config_result
+
+	return build_tests(linux, request)
+
 def _list_tests(linux: kunit_kernel.LinuxSourceTree, request: KunitExecRequest) -> List[str]:
 	args = ['kunit.action=list']
 	if request.kernel_args:
@@ -464,7 +472,7 @@ def main(argv, linux=None):
 					    make_options=cli_args.make_options,
 					    jobs=cli_args.jobs,
 					    alltests=cli_args.alltests)
-		result = build_tests(linux, request)
+		result = config_and_build_tests(linux, request)
 		kunit_parser.print_with_timestamp((
 			'Elapsed time: %.3fs\n') % (
 				result.elapsed_time))

tools/testing/kunit/kunit_tool_test.py

@@ -526,7 +526,7 @@ def test_config_passes_args_pass(self):
 
 	def test_build_passes_args_pass(self):
 		kunit.main(['build'], self.linux_source_mock)
-		self.assertEqual(self.linux_source_mock.build_reconfig.call_count, 0)
+		self.assertEqual(self.linux_source_mock.build_reconfig.call_count, 1)
 		self.linux_source_mock.build_kernel.assert_called_once_with(False, 8, '.kunit', None)
 		self.assertEqual(self.linux_source_mock.run_kernel.call_count, 0)