kunit: tool: move Kconfig read_from_file/parse_from_string to package-level

read_from_file() clears its `self` Kconfig object and parses a config
file.

It is a way to construct Kconfig objects more so than an operation on
Kconfig objects. This is reflected in the fact its only ever used as:
  kconfig = kunit_config.Kconfig()
  kconfig.read_from_file(path)

So clean this up and simplify callers by replacing it with
  kconfig = kunit_config.parse_file(path)

Do the same thing for the related parse_from_string() function as well.
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_config.py

@@ -62,33 +62,34 @@ class Kconfig(object):
 			for entry in self.entries():
 				f.write(str(entry) + '\n')
 
-	def parse_from_string(self, blob: str) -> None:
-		"""Parses a string containing KconfigEntrys and populates this Kconfig."""
-		self._entries = []
-		is_not_set_matcher = re.compile(CONFIG_IS_NOT_SET_PATTERN)
-		config_matcher = re.compile(CONFIG_PATTERN)
-		for line in blob.split('\n'):
-			line = line.strip()
-			if not line:
-				continue
-
-			match = config_matcher.match(line)
-			if match:
-				entry = KconfigEntry(match.group(1), match.group(2))
-				self.add_entry(entry)
-				continue
-
-			empty_match = is_not_set_matcher.match(line)
-			if empty_match:
-				entry = KconfigEntry(empty_match.group(1), 'n')
-				self.add_entry(entry)
-				continue
-
-			if line[0] == '#':
-				continue
-			else:
-				raise KconfigParseError('Failed to parse: ' + line)
-
-	def read_from_file(self, path: str) -> None:
-		with open(path, 'r') as f:
-			self.parse_from_string(f.read())
+def parse_file(path: str) -> Kconfig:
+	with open(path, 'r') as f:
+		return parse_from_string(f.read())
+
+def parse_from_string(blob: str) -> Kconfig:
+	"""Parses a string containing Kconfig entries."""
+	kconfig = Kconfig()
+	is_not_set_matcher = re.compile(CONFIG_IS_NOT_SET_PATTERN)
+	config_matcher = re.compile(CONFIG_PATTERN)
+	for line in blob.split('\n'):
+		line = line.strip()
+		if not line:
+			continue
+
+		match = config_matcher.match(line)
+		if match:
+			entry = KconfigEntry(match.group(1), match.group(2))
+			kconfig.add_entry(entry)
+			continue
+
+		empty_match = is_not_set_matcher.match(line)
+		if empty_match:
+			entry = KconfigEntry(empty_match.group(1), 'n')
+			kconfig.add_entry(entry)
+			continue
+
+		if line[0] == '#':
+			continue
+		else:
+			raise KconfigParseError('Failed to parse: ' + line)
+	return kconfig

tools/testing/kunit/kunit_kernel.py

@@ -116,8 +116,7 @@ class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):
 		self._extra_qemu_params = qemu_arch_params.extra_qemu_params
 
 	def make_arch_qemuconfig(self, base_kunitconfig: kunit_config.Kconfig) -> None:
-		kconfig = kunit_config.Kconfig()
-		kconfig.parse_from_string(self._kconfig)
+		kconfig = kunit_config.parse_from_string(self._kconfig)
 		base_kunitconfig.merge_in_entries(kconfig)
 
 	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
@@ -249,8 +248,7 @@ class LinuxSourceTree(object):
 			if not os.path.exists(kunitconfig_path):
 				shutil.copyfile(DEFAULT_KUNITCONFIG_PATH, kunitconfig_path)
 
-		self._kconfig = kunit_config.Kconfig()
-		self._kconfig.read_from_file(kunitconfig_path)
+		self._kconfig = kunit_config.parse_file(kunitconfig_path)
 
 	def clean(self) -> bool:
 		try:
@@ -262,8 +260,7 @@ class LinuxSourceTree(object):
 
 	def validate_config(self, build_dir) -> bool:
 		kconfig_path = get_kconfig_path(build_dir)
-		validated_kconfig = kunit_config.Kconfig()
-		validated_kconfig.read_from_file(kconfig_path)
+		validated_kconfig = kunit_config.parse_file(kconfig_path)
 		if not self._kconfig.is_subset_of(validated_kconfig):
 			invalid = self._kconfig.entries() - validated_kconfig.entries()
 			message = 'Provided Kconfig is not contained in validated .config. Following fields found in kunitconfig, ' \
@@ -291,8 +288,7 @@ class LinuxSourceTree(object):
 		"""Creates a new .config if it is not a subset of the .kunitconfig."""
 		kconfig_path = get_kconfig_path(build_dir)
 		if os.path.exists(kconfig_path):
-			existing_kconfig = kunit_config.Kconfig()
-			existing_kconfig.read_from_file(kconfig_path)
+			existing_kconfig = kunit_config.parse_file(kconfig_path)
 			self._ops.make_arch_qemuconfig(self._kconfig)
 			if not self._kconfig.is_subset_of(existing_kconfig):
 				print('Regenerating .config ...')

tools/testing/kunit/kunit_tool_test.py

@@ -51,10 +51,9 @@ class KconfigTest(unittest.TestCase):
 		self.assertFalse(kconfig1.is_subset_of(kconfig0))
 
 	def test_read_from_file(self):
-		kconfig = kunit_config.Kconfig()
 		kconfig_path = test_data_path('test_read_from_file.kconfig')
 
-		kconfig.read_from_file(kconfig_path)
+		kconfig = kunit_config.parse_file(kconfig_path)
 
 		expected_kconfig = kunit_config.Kconfig()
 		expected_kconfig.add_entry(
@@ -87,8 +86,7 @@ class KconfigTest(unittest.TestCase):
 
 		expected_kconfig.write_to_file(kconfig_path)
 
-		actual_kconfig = kunit_config.Kconfig()
-		actual_kconfig.read_from_file(kconfig_path)
+		actual_kconfig = kunit_config.parse_file(kconfig_path)
 
 		self.assertEqual(actual_kconfig.entries(),
 				 expected_kconfig.entries())