kunit: tool: add subscripts for type annotations where appropriate

E.g. for subprocess.Popen, it can be opened in `text=True` mode where it
returns strings, or `text=False` where it returns bytes.
To differentiate, you can annotate types as `Popen[str]` or
`Popen[bytes]`.

This patch should add subscripts in all the places we were missing them.

Reported-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/linux-kselftest/20230315105055.9b2be0153625.I7a2cb99b95dff216c0feed4604255275e0b156a7@changeid/
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/kunit/kunit_kernel.py

@@ -92,7 +92,7 @@ def make(self, jobs, build_dir: str, make_options) -> None:
 		if stderr:  # likely only due to build warnings
 			print(stderr.decode())
 
-	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
+	def start(self, params: List[str], build_dir: str) -> subprocess.Popen[str]:
 		raise RuntimeError('not implemented!')
 
 
@@ -112,7 +112,7 @@ def make_arch_config(self, base_kunitconfig: kunit_config.Kconfig) -> kunit_conf
 		kconfig.merge_in_entries(base_kunitconfig)
 		return kconfig
 
-	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
+	def start(self, params: List[str], build_dir: str) -> subprocess.Popen[str]:
 		kernel_path = os.path.join(build_dir, self._kernel_path)
 		qemu_command = ['qemu-system-' + self._qemu_arch,
 				'-nodefaults',
@@ -141,7 +141,7 @@ def make_arch_config(self, base_kunitconfig: kunit_config.Kconfig) -> kunit_conf
 		kconfig.merge_in_entries(base_kunitconfig)
 		return kconfig
 
-	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
+	def start(self, params: List[str], build_dir: str) -> subprocess.Popen[str]:
 		"""Runs the Linux UML binary. Must be named 'linux'."""
 		linux_bin = os.path.join(build_dir, 'linux')
 		params.extend(['mem=1G', 'console=tty', 'kunit_shutdown=halt'])

tools/testing/kunit/kunit_printer.py

@@ -15,7 +15,7 @@
 class Printer:
 	"""Wraps a file object, providing utilities for coloring output, etc."""
 
-	def __init__(self, output: typing.IO):
+	def __init__(self, output: typing.IO[str]):
 		self._output = output
 		self._use_color = output.isatty()
 

tools/testing/kunit/run_checks.py

@@ -37,7 +37,7 @@ def main(argv: Sequence[str]) -> None:
 	if argv:
 		raise RuntimeError('This script takes no arguments')
 
-	future_to_name: Dict[futures.Future, str] = {}
+	future_to_name: Dict[futures.Future[None], str] = {}
 	executor = futures.ThreadPoolExecutor(max_workers=len(commands))
 	for name, argv in commands.items():
 		if name in necessary_deps and shutil.which(necessary_deps[name]) is None: