Add a bunch more type annotations

mypy --check-untyped-defs -p virtme passes now

Signed-off-by: Andy Lutomirski <luto@kernel.org>

5 files changed, 25 insertions, 16 deletions

diff --git a/virtme/commands/configkernel.py b/virtme/commands/configkernel.py
index bd3d42f..489d6a7 100644
--- a/virtme/commands/configkernel.py
+++ b/virtme/commands/configkernel.py
@@ -5,6 +5,8 @@
 # as a file called LICENSE with SHA-256 hash:
 # 8177f97513213526df2cf6184d8ff986c675afb514d4e68a404010521b880643
 
+from typing import Optional
+
 import argparse
 import tempfile
 import os
@@ -103,6 +105,8 @@ def main():
     if shutil.which('%s-linux-gnu-gcc' % arch.gccname):
         conf.append('CONFIG_CROSS_COMPILE="%s-linux-gnu-"' % arch.gccname)
 
+    maketarget: Optional[str]
+
     if args.allnoconfig:
         maketarget = 'allnoconfig'
         updatetarget = 'silentoldconfig'
diff --git a/virtme/commands/run.py b/virtme/commands/run.py
index 16422d1..263bdd2 100644
--- a/virtme/commands/run.py
+++ b/virtme/commands/run.py
@@ -475,11 +475,12 @@ def do_it():
         if args.busybox is not None:
             config.busybox = args.busybox
         else:
-            config.busybox = mkinitramfs.find_busybox(args.root, is_native)
-            if config.busybox is None:
+            busybox = mkinitramfs.find_busybox(args.root, is_native)
+            if busybox is None:
                 print('virtme-run: initramfs is needed, and no busybox was found',
                       file=sys.stderr)
                 return 1
+            config.busybox = busybox
 
         if args.rw:
             config.access = 'rw'
diff --git a/virtme/guest_tools.py b/virtme/guest_tools.py
index b84f761..2505b49 100644
--- a/virtme/guest_tools.py
+++ b/virtme/guest_tools.py
@@ -22,7 +22,7 @@ def find_guest_tools():
     # No luck.  This is somewhat surprising.
     return None
 
-def find_script(name):
+def find_script(name) -> str:
     # If we're running out of a source checkout, we can find scripts through
     # the 'virtme/scripts' symlink.
     fn = pkg_resources.resource_filename(__name__, 'scripts/%s' % name)
@@ -30,13 +30,13 @@ def find_script(name):
         return fn
 
     # Otherwise assume we're actually installed and in PATH.
-    fn = shutil.which(name)
-    if fn is not None:
-        return fn
+    guess = shutil.which(name)
+    if guess is not None:
+        return guess
 
     # No luck.  This is somewhat surprising.
     raise Exception('could not find script %s' % name)
 
-def run_script(name):
+def run_script(name) -> None:
     fn = find_script(name)
     subprocess.check_call(executable=fn, args=[fn])
diff --git a/virtme/mkinitramfs.py b/virtme/mkinitramfs.py
index dde504d..797fbfe 100644
--- a/virtme/mkinitramfs.py
+++ b/virtme/mkinitramfs.py
@@ -5,6 +5,8 @@
 # as a file called LICENSE with SHA-256 hash:
 # 8177f97513213526df2cf6184d8ff986c675afb514d4e68a404010521b880643
 
+from typing import List, Dict, Optional
+
 import shutil
 import io
 import os.path
@@ -136,7 +138,7 @@ exec /bin/switch_root /newroot "$init" "$@"
 """
 
 
-def generate_init(config):
+def generate_init(config) -> bytes:
     out = io.StringIO()
     out.write(_INIT.format(
         logfunc=_LOGFUNC,
@@ -146,13 +148,13 @@ def generate_init(config):
 class Config:
     __slots__ = ['modfiles', 'virtme_data', 'virtme_init_path', 'busybox', 'access']
     def __init__(self):
-        self.modfiles = []
-        self.virtme_data = {}
-        self.virtme_init_path = None
-        self.busybox = None
+        self.modfiles: List[str] = []
+        self.virtme_data: Dict[bytes, bytes] = {}
+        self.virtme_init_path: Optional[str] = None
+        self.busybox: Optional[str] = None
         self.access = 'ro'
 
-def mkinitramfs(out, config):
+def mkinitramfs(out, config) -> None:
     cw = cpiowriter.CpioWriter(out)
     make_base_layout(cw)
     make_dev_nodes(cw)
@@ -166,7 +168,7 @@ def mkinitramfs(out, config):
                   mode=0o755)
     cw.write_trailer()
 
-def find_busybox(root, is_native):
+def find_busybox(root, is_native) -> Optional[str]:
     for p in itertools.product(['usr/local', 'usr', ''],
                                ['bin', 'sbin'],
                                ['', '-static', '.static']):
diff --git a/virtme/modfinder.py b/virtme/modfinder.py
index f0a0601..d0269b0 100644
--- a/virtme/modfinder.py
+++ b/virtme/modfinder.py
@@ -11,6 +11,8 @@ sort of hotplug.  Instead it generates a topological order and loads
 everything.  The idea is to require very few modules.
 """
 
+from typing import List
+
 import re
 import shutil
 import subprocess
@@ -49,8 +51,8 @@ def resolve_dep(modalias, root=None, kver=None, moddir=None):
 
     return deps
 
-def merge_mods(lists):
-    found = set()
+def merge_mods(lists) -> List[str]:
+    found: set = set()
     mods = []
     for mod in itertools.chain(*lists):
         if mod not in found: