Fix Use of cache on methods can lead to memory leaks

Author: Pierre-Sassoulas

astroid/interpreter/objectmodel.py

@@ -25,8 +25,7 @@
 import os
 import pprint
 import types
-from functools import lru_cache
-from typing import TYPE_CHECKING, Optional
+from typing import TYPE_CHECKING, List, Optional
 
 import astroid
 from astroid import util
@@ -41,6 +40,7 @@
     from astroid.objects import Property
 
 IMPL_PREFIX = "attr_"
+LEN_OF_IMPL_PREFIX = len(IMPL_PREFIX)
 
 
 def _dunder_dict(instance, attributes):
@@ -100,20 +100,16 @@ def __get__(self, instance, cls=None):
     def __contains__(self, name):
         return name in self.attributes()
 
-    @lru_cache(maxsize=None)
-    def attributes(self):
+    def attributes(self) -> List[str]:
         """Get the attributes which are exported by this object model."""
-        return [
-            obj[len(IMPL_PREFIX) :] for obj in dir(self) if obj.startswith(IMPL_PREFIX)
-        ]
+        return [o[LEN_OF_IMPL_PREFIX:] for o in dir(self) if o.startswith(IMPL_PREFIX)]
 
     def lookup(self, name):
         """Look up the given *name* in the current model
 
         It should return an AST or an interpreter object,
         but if the name is not found, then an AttributeInferenceError will be raised.
         """
-
         if name in self.attributes():
             return getattr(self, IMPL_PREFIX + name)
         raise AttributeInferenceError(target=self._instance, attribute=name)

astroid/nodes/node_classes.py

@@ -367,21 +367,19 @@ def get_children(self):
 class LookupMixIn:
     """Mixin to look up a name in the right scope."""
 
-    @lru_cache(maxsize=None)
-    def lookup(self, name):
+    @lru_cache(maxsize=None)  # pylint: disable=cache-max-size-none  # noqa
+    def lookup(self, name: str) -> typing.Tuple[str, typing.List[NodeNG]]:
         """Lookup where the given variable is assigned.
 
         The lookup starts from self's scope. If self is not a frame itself
         and the name is found in the inner frame locals, statements will be
         filtered to remove ignorable statements according to self's location.
 
         :param name: The name of the variable to find assignments for.
-        :type name: str
 
         :returns: The scope node and the list of assignments associated to the
             given name according to the scope where it has been found (locals,
             globals or builtin).
-        :rtype: tuple(str, list(NodeNG))
         """
         return self.scope().scope_lookup(self, name)
 

astroid/transforms.py

@@ -3,10 +3,13 @@
 # Copyright (c) https://github.com/PyCQA/astroid/blob/main/CONTRIBUTORS.txt
 
 import collections
-from functools import lru_cache
+from typing import TYPE_CHECKING
 
 from astroid.context import _invalidate_cache
 
+if TYPE_CHECKING:
+    from astroid import NodeNG
+
 
 class TransformVisitor:
     """A visitor for handling transforms.
@@ -17,13 +20,10 @@ class TransformVisitor:
     transforms for each encountered node.
     """
 
-    TRANSFORM_MAX_CACHE_SIZE = 10000
-
     def __init__(self):
         self.transforms = collections.defaultdict(list)
 
-    @lru_cache(maxsize=TRANSFORM_MAX_CACHE_SIZE)
-    def _transform(self, node):
+    def _transform(self, node: "NodeNG") -> "NodeNG":
         """Call matching transforms for the given node if any and return the
         transformed node.
         """