diff --git a/hgext/remotefilelog/debugcommands.py b/hgext/remotefilelog/debugcommands.py
--- a/hgext/remotefilelog/debugcommands.py
+++ b/hgext/remotefilelog/debugcommands.py
@@ -62,7 +62,7 @@ def debugremotefilelog(ui, path, **opts)
             queue.append(p2)
 
 
-def buildtemprevlog(repo, file):
+def buildtemprevlog(repo, file) -> filelog.FileLog:
     # get filename key
     filekey = hex(hashutil.sha1(file).digest())
     filedir = os.path.join(repo.path, b'store/data', filekey)
diff --git a/hgext/remotefilelog/remotefilelog.py b/hgext/remotefilelog/remotefilelog.py
--- a/hgext/remotefilelog/remotefilelog.py
+++ b/hgext/remotefilelog/remotefilelog.py
@@ -8,6 +8,10 @@
 
 import collections
 
+from typing import (
+    Iterator,
+)
+
 from mercurial.node import bin
 from mercurial.i18n import _
 from mercurial import (
@@ -296,7 +300,7 @@ class remotefilelog:
         deltamode=None,
         sidedata_helpers=None,
         debug_info=None,
-    ):
+    ) -> Iterator[revlog.RevLogRevisionDelta]:
         # we don't use any of these parameters here
         del nodesorder, revisiondata, assumehaveparentrevisions, deltaprevious
         del deltamode
diff --git a/mercurial/filelog.py b/mercurial/filelog.py
--- a/mercurial/filelog.py
+++ b/mercurial/filelog.py
@@ -8,6 +8,11 @@
 
 import typing
 
+from typing import (
+    Iterable,
+    Iterator,
+)
+
 from .i18n import _
 from .node import nullrev
 from . import (
@@ -26,6 +31,10 @@ from .revlogutils import (
 
 
 class FileLog:
+    _revlog: revlog.revlog
+    nullid: bytes
+    _fix_issue6528: bool
+
     def __init__(self, opener, path, try_split=False):
         self._revlog = revlog.revlog(
             opener,
@@ -43,7 +52,7 @@ class FileLog:
         opts = opener.options
         self._fix_issue6528 = opts.get(b'issue6528.fix-incoming', True)
 
-    def get_revlog(self):
+    def get_revlog(self) -> revlog.revlog:
         """return an actual revlog instance if any
 
         This exist because a lot of code leverage the fact the underlying
@@ -52,10 +61,10 @@ class FileLog:
         """
         return self._revlog
 
-    def __len__(self):
+    def __len__(self) -> int:
         return len(self._revlog)
 
-    def __iter__(self):
+    def __iter__(self) -> Iterator[int]:
         return self._revlog.__iter__()
 
     def hasnode(self, node):
@@ -234,7 +243,7 @@ class FileLog:
         """
         return not storageutil.filedataequivalent(self, node, text)
 
-    def verifyintegrity(self, state):
+    def verifyintegrity(self, state) -> Iterable[revlog.RevLogProblem]:
         return self._revlog.verifyintegrity(state)
 
     def storageinfo(
diff --git a/mercurial/manifest.py b/mercurial/manifest.py
--- a/mercurial/manifest.py
+++ b/mercurial/manifest.py
@@ -850,6 +850,12 @@ def _splittopdir(f: bytes) -> Tuple[byte
 
 
 class TreeManifest:
+    _dir: bytes
+    _dirs: Dict[bytes, 'TreeManifest']
+    _dirty: bool
+    _files: Dict[bytes, bytes]
+    _flags: Dict[bytes, bytes]
+
     def __init__(self, nodeconstants, dir: bytes = b'', text: bytes = b''):
         self._dir = dir
         self.nodeconstants = nodeconstants
@@ -858,13 +864,13 @@ class TreeManifest:
         self._loadfunc = _noop
         self._copyfunc = _noop
         self._dirty = False
-        self._dirs: Dict[bytes, 'TreeManifest'] = {}
+        self._dirs = {}
         self._lazydirs: Dict[
             bytes,
             Tuple[bytes, Callable[[bytes, bytes], 'TreeManifest'], bool],
         ] = {}
         # Using _lazymanifest here is a little slower than plain old dicts
-        self._files: Dict[bytes, bytes] = {}
+        self._files = {}
         self._flags = {}
         if text:
 
@@ -2172,6 +2178,8 @@ if typing.TYPE_CHECKING:
 
 
 class MemManifestCtx:
+    _manifestdict: ManifestDict
+
     def __init__(self, manifestlog):
         self._manifestlog = manifestlog
         self._manifestdict = manifestdict(manifestlog.nodeconstants.nodelen)
@@ -2213,6 +2221,8 @@ class ManifestCtx:
     contents, its parent revs, and its linkrev.
     """
 
+    _data: Optional[ManifestDict]
+
     def __init__(self, manifestlog, node):
         self._manifestlog = manifestlog
         self._data = None
@@ -2375,6 +2385,8 @@ if typing.TYPE_CHECKING:
 
 
 class MemTreeManifestCtx:
+    _treemanifest: TreeManifest
+
     def __init__(self, manifestlog, dir=b''):
         self._manifestlog = manifestlog
         self._dir = dir
@@ -2417,6 +2429,8 @@ if typing.TYPE_CHECKING:
 
 
 class TreeManifestCtx:
+    _data: Optional[TreeManifest]
+
     def __init__(self, manifestlog, dir, node):
         self._manifestlog = manifestlog
         self._dir = dir
@@ -2699,6 +2713,9 @@ class excludeddir(treemanifest):
     whose contents are unknown.
     """
 
+    _files: Dict[bytes, bytes]
+    _flags: Dict[bytes, bytes]
+
     def __init__(self, nodeconstants, dir, node):
         super(excludeddir, self).__init__(nodeconstants, dir)
         self._node = node
diff --git a/mercurial/revlog.py b/mercurial/revlog.py
--- a/mercurial/revlog.py
+++ b/mercurial/revlog.py
@@ -25,6 +25,8 @@ import weakref
 import zlib
 
 from typing import (
+    Iterable,
+    Iterator,
     Optional,
     Tuple,
 )
@@ -1826,7 +1828,7 @@ class revlog:
     def __len__(self):
         return len(self.index)
 
-    def __iter__(self):
+    def __iter__(self) -> Iterator[int]:
         return iter(range(len(self)))
 
     def revs(self, start=0, stop=None):
@@ -3902,7 +3904,7 @@ class revlog:
         else:
             rewrite.v2_censor(self, tr, censor_nodes, tombstone)
 
-    def verifyintegrity(self, state):
+    def verifyintegrity(self, state) -> Iterable[RevLogProblem]:
         """Verifies the integrity of the revlog.
 
         Yields ``revlogproblem`` instances describing problems that are
diff --git a/mercurial/statichttprepo.py b/mercurial/statichttprepo.py
--- a/mercurial/statichttprepo.py
+++ b/mercurial/statichttprepo.py
@@ -160,6 +160,8 @@ class statichttprepository(
 ):
     supported = localrepo.localrepository._basesupported
 
+    manifestlog: manifest.ManifestLog
+
     def __init__(self, ui, path):
         self._url = path
         self.ui = ui
diff --git a/mercurial/store.py b/mercurial/store.py
--- a/mercurial/store.py
+++ b/mercurial/store.py
@@ -817,7 +817,7 @@ class basicstore:
             concurrencychecker=concurrencychecker,
         )
 
-    def manifestlog(self, repo, storenarrowmatch):
+    def manifestlog(self, repo, storenarrowmatch) -> manifest.ManifestLog:
         rootstore = manifest.manifestrevlog(repo.nodeconstants, self.vfs)
         return manifest.manifestlog(self.vfs, repo, rootstore, storenarrowmatch)
 
diff --git a/mercurial/unionrepo.py b/mercurial/unionrepo.py
--- a/mercurial/unionrepo.py
+++ b/mercurial/unionrepo.py
@@ -204,6 +204,9 @@ class unionchangelog(unionrevlog, change
 
 
 class unionmanifest(unionrevlog, manifest.manifestrevlog):
+    repotiprev: int
+    revlog2: manifest.ManifestRevlog
+
     def __init__(self, nodeconstants, opener, opener2, linkmapper):
         # XXX manifestrevlog is not actually a revlog , so mixing it with
         # bundlerevlog is not a good idea.
@@ -215,6 +218,10 @@ class unionmanifest(unionrevlog, manifes
 
 
 class unionfilelog(filelog.filelog):
+    _revlog: unionrevlog
+    repotiprev: int
+    revlog2: revlog.revlog
+
     def __init__(self, opener, path, opener2, linkmapper, repo):
         filelog.filelog.__init__(self, opener, path)
         filelog2 = filelog.filelog(opener2, path)