https://github.com/python/cpython/commit/2e0d445364f6d9832e81263c1c68440654924fc4 commit: 2e0d445364f6d9832e81263c1c68440654924fc4 branch: main author: Jelle Zijlstra <[email protected]> committer: JelleZijlstra <[email protected]> date: 2024-09-23T19:06:19Z summary:
gh-119180: Fix annotationlib.ForwardRef.evaluate with no globals (#124326) We were sometimes passing None as the globals argument to eval(), which makes it inherit the globals from the calling scope. Instead, ensure that globals is always non-None. The test was passing accidentally because I passed "annotationlib" as a module object; fix that. Also document the parameters to ForwardRef() and remove two unused private ones. Co-authored-by: Alex Waygood <[email protected]> files: M Lib/annotationlib.py M Lib/test/test_annotationlib.py diff --git a/Lib/annotationlib.py b/Lib/annotationlib.py index 09a844ddb56f06..0a67742a2b3081 100644 --- a/Lib/annotationlib.py +++ b/Lib/annotationlib.py @@ -45,7 +45,17 @@ class Format(enum.IntEnum): class ForwardRef: - """Wrapper that holds a forward reference.""" + """Wrapper that holds a forward reference. + + Constructor arguments: + * arg: a string representing the code to be evaluated. + * module: the module where the forward reference was created. + Must be a string, not a module object. + * owner: The owning object (module, class, or function). + * is_argument: Does nothing, retained for compatibility. + * is_class: True if the forward reference was created in class scope. + + """ __slots__ = _SLOTS @@ -57,8 +67,6 @@ def __init__( owner=None, is_argument=True, is_class=False, - _globals=None, - _cell=None, ): if not isinstance(arg, str): raise TypeError(f"Forward reference must be a string -- got {arg!r}") @@ -71,8 +79,8 @@ def __init__( self.__forward_module__ = module self.__code__ = None self.__ast_node__ = None - self.__globals__ = _globals - self.__cell__ = _cell + self.__globals__ = None + self.__cell__ = None self.__owner__ = owner def __init_subclass__(cls, /, *args, **kwds): @@ -115,6 +123,10 @@ def evaluate(self, *, globals=None, locals=None, type_params=None, owner=None): elif callable(owner): globals = getattr(owner, "__globals__", None) + # If we pass None to eval() below, the globals of this module are used. + if globals is None: + globals = {} + if locals is None: locals = {} if isinstance(owner, type): @@ -134,14 +146,8 @@ def evaluate(self, *, globals=None, locals=None, type_params=None, owner=None): # but should in turn be overridden by names in the class scope # (which here are called `globalns`!) if type_params is not None: - if globals is None: - globals = {} - else: - globals = dict(globals) - if locals is None: - locals = {} - else: - locals = dict(locals) + globals = dict(globals) + locals = dict(locals) for param in type_params: param_name = param.__name__ if not self.__forward_is_class__ or param_name not in globals: diff --git a/Lib/test/test_annotationlib.py b/Lib/test/test_annotationlib.py index 309f6d2120109a..dd8ceb55a411fb 100644 --- a/Lib/test/test_annotationlib.py +++ b/Lib/test/test_annotationlib.py @@ -1,6 +1,7 @@ """Tests for the annotations module.""" import annotationlib +import collections import functools import itertools import pickle @@ -278,11 +279,24 @@ class Gen[T]: ) def test_fwdref_with_module(self): - self.assertIs(ForwardRef("Format", module=annotationlib).evaluate(), Format) + self.assertIs(ForwardRef("Format", module="annotationlib").evaluate(), Format) + self.assertIs(ForwardRef("Counter", module="collections").evaluate(), collections.Counter) with self.assertRaises(NameError): # If globals are passed explicitly, we don't look at the module dict - ForwardRef("Format", module=annotationlib).evaluate(globals={}) + ForwardRef("Format", module="annotationlib").evaluate(globals={}) + + def test_fwdref_to_builtin(self): + self.assertIs(ForwardRef("int").evaluate(), int) + self.assertIs(ForwardRef("int", module="collections").evaluate(), int) + self.assertIs(ForwardRef("int", owner=str).evaluate(), int) + + # builtins are still searched with explicit globals + self.assertIs(ForwardRef("int").evaluate(globals={}), int) + + # explicit values in globals have precedence + obj = object() + self.assertIs(ForwardRef("int").evaluate(globals={"int": obj}), obj) def test_fwdref_value_is_cached(self): fr = ForwardRef("hello") _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-checkins.python.org/ Member address: [email protected]
