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Revert CallContext change since it caused a RecursionError regression (
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cdce8p committed Jan 31, 2023
1 parent 943cd49 commit 72f5afb
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Showing 8 changed files with 51 additions and 17 deletions.
2 changes: 2 additions & 0 deletions ChangeLog
Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,8 @@ What's New in astroid 2.14.1?
=============================
Release date: TBA

* Revert ``CallContext`` change as it caused a ``RecursionError`` regression.



What's New in astroid 2.14.0?
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34 changes: 34 additions & 0 deletions astroid/brain/brain_typing.py
Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,7 @@
Const,
JoinedStr,
Name,
NodeNG,
Subscript,
Tuple,
)
Expand Down Expand Up @@ -379,6 +380,36 @@ def infer_special_alias(
return iter([class_def])


def _looks_like_typing_cast(node: Call) -> bool:
return isinstance(node, Call) and (
isinstance(node.func, Name)
and node.func.name == "cast"
or isinstance(node.func, Attribute)
and node.func.attrname == "cast"
)


def infer_typing_cast(
node: Call, ctx: context.InferenceContext | None = None
) -> Iterator[NodeNG]:
"""Infer call to cast() returning same type as casted-from var."""
if not isinstance(node.func, (Name, Attribute)):
raise UseInferenceDefault

try:
func = next(node.func.infer(context=ctx))
except (InferenceError, StopIteration) as exc:
raise UseInferenceDefault from exc
if (
not isinstance(func, FunctionDef)
or func.qname() != "typing.cast"
or len(node.args) != 2
):
raise UseInferenceDefault

return node.args[1].infer(context=ctx)


AstroidManager().register_transform(
Call,
inference_tip(infer_typing_typevar_or_newtype),
Expand All @@ -387,6 +418,9 @@ def infer_special_alias(
AstroidManager().register_transform(
Subscript, inference_tip(infer_typing_attr), _looks_like_typing_subscript
)
AstroidManager().register_transform(
Call, inference_tip(infer_typing_cast), _looks_like_typing_cast
)

if PY39_PLUS:
AstroidManager().register_transform(
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6 changes: 1 addition & 5 deletions astroid/context.py
Original file line number Diff line number Diff line change
Expand Up @@ -161,14 +161,13 @@ def __str__(self) -> str:
class CallContext:
"""Holds information for a call site."""

__slots__ = ("args", "keywords", "callee", "parent_call_context")
__slots__ = ("args", "keywords", "callee")

def __init__(
self,
args: list[NodeNG],
keywords: list[Keyword] | None = None,
callee: NodeNG | None = None,
parent_call_context: CallContext | None = None,
):
self.args = args # Call positional arguments
if keywords:
Expand All @@ -177,9 +176,6 @@ def __init__(
arg_value_pairs = []
self.keywords = arg_value_pairs # Call keyword arguments
self.callee = callee # Function being called
self.parent_call_context = (
parent_call_context # Parent CallContext for nested calls
)


def copy_context(context: InferenceContext | None) -> InferenceContext:
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5 changes: 1 addition & 4 deletions astroid/inference.py
Original file line number Diff line number Diff line change
Expand Up @@ -274,10 +274,7 @@ def infer_call(
try:
if hasattr(callee, "infer_call_result"):
callcontext.callcontext = CallContext(
args=self.args,
keywords=self.keywords,
callee=callee,
parent_call_context=callcontext.callcontext,
args=self.args, keywords=self.keywords, callee=callee
)
yield from callee.infer_call_result(caller=self, context=callcontext)
except InferenceError:
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2 changes: 1 addition & 1 deletion astroid/protocols.py
Original file line number Diff line number Diff line change
Expand Up @@ -470,7 +470,7 @@ def arguments_assigned_stmts(
# reset call context/name
callcontext = context.callcontext
context = copy_context(context)
context.callcontext = callcontext.parent_call_context
context.callcontext = None
args = arguments.CallSite(callcontext, context=context)
return args.infer_argument(self.parent, node_name, context)
return _arguments_infer_argname(self, node_name, context)
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9 changes: 8 additions & 1 deletion tests/unittest_brain.py
Original file line number Diff line number Diff line change
Expand Up @@ -2160,6 +2160,13 @@ class A:
assert inferred.value == 42

def test_typing_cast_multiple_inference_calls(self) -> None:
"""Inference of an outer function should not store the result for cast.
https://github.com/PyCQA/pylint/issues/8074
Possible solution caused RecursionErrors with Python 3.8 and CPython + PyPy.
https://github.com/PyCQA/astroid/pull/1982
"""
ast_nodes = builder.extract_node(
"""
from typing import TypeVar, cast
Expand All @@ -2177,7 +2184,7 @@ def ident(var: T) -> T:

i1 = next(ast_nodes[1].infer())
assert isinstance(i1, nodes.Const)
assert i1.value == "Hello"
assert i1.value == 2 # should be "Hello"!


@pytest.mark.skipif(
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5 changes: 1 addition & 4 deletions tests/unittest_inference.py
Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@
from astroid.arguments import CallSite
from astroid.bases import BoundMethod, Instance, UnboundMethod, UnionType
from astroid.builder import AstroidBuilder, _extract_single_node, extract_node, parse
from astroid.const import IS_PYPY, PY38_PLUS, PY39_PLUS, PY310_PLUS
from astroid.const import PY38_PLUS, PY39_PLUS, PY310_PLUS
from astroid.context import InferenceContext
from astroid.exceptions import (
AstroidTypeError,
Expand Down Expand Up @@ -6934,9 +6934,6 @@ def test_imported_module_var_inferable3() -> None:
assert i_w_val.as_string() == "['w', 'v']"


@pytest.mark.skipif(
IS_PYPY, reason="Test run with coverage on PyPy sometimes raises a RecursionError"
)
def test_recursion_on_inference_tip() -> None:
"""Regression test for recursion in inference tip.
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5 changes: 3 additions & 2 deletions tests/unittest_inference_calls.py
Original file line number Diff line number Diff line change
Expand Up @@ -146,6 +146,8 @@ def g(y):
def test_inner_call_with_dynamic_argument() -> None:
"""Test function where return value is the result of a separate function call,
with a dynamic value passed to the inner function.
Currently, this is Uninferable.
"""
node = builder.extract_node(
"""
Expand All @@ -161,8 +163,7 @@ def g(y):
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == 3
assert inferred[0] is Uninferable


def test_method_const_instance_attr() -> None:
Expand Down

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