Crash due to decorator and generator interaction #18780
Description
Crash Report
This crash likely arises due to a combination of decorators and generators. I created a minimal example below (it is derived from a more complex project and might make no sense in the shown context but the crash still occurs).
Traceback
Traceback (most recent call last):
File "mypy/checker.py", line 576, in accept
File "mypy/nodes.py", line 923, in accept
File "mypy/checker.py", line 5136, in visit_decorator
File "mypy/checker.py", line 5163, in visit_decorator_inner
File "mypy/checkexpr.py", line 1572, in check_call
File "mypy/checkexpr.py", line 1757, in check_callable_call
File "mypy/checkexpr.py", line 2100, in infer_function_type_arguments
File "mypy/checkexpr.py", line 2235, in infer_function_type_arguments_pass2
File "mypy/infer.py", line 57, in infer_function_type_arguments
File "mypy/constraints.py", line 251, in infer_constraints_for_callable
File "mypy/constraints.py", line 319, in infer_constraints
File "mypy/constraints.py", line 427, in _infer_constraints
File "mypy/types.py", line 2009, in accept
File "mypy/constraints.py", line 1182, in visit_callable_type
File "mypy/constraints.py", line 1349, in infer_against_any
To Reproduce
# example.py
from enum import Enum
from typing import Callable, Generator, TypeVar, TypeVarTuple
Arg = TypeVarTuple("Arg")
Ret = TypeVar("Ret")
task = TypeVar("task")
def dec1(e: str):
def decorator(func: Callable[[*Arg], Ret]) -> Callable[[*Arg], Ret]:
def fn(*args: *Arg) -> Ret:
return func(*args)
return fn
return decorator
def to_coro(func: Callable[[*Arg, task], Ret | task]):
def coro(*args: *Arg) -> Generator[Ret | None | task, task, None]:
t: None | task | Ret = None
while True:
t = yield t
t = func(*(args + (t,)))
return coro
@to_coro
@dec1("asd")
def example_function(a: int, b: int) -> int:
return a + bmypy ./exampe.pyIf I remove the dec1 the crash disappears.
My Environment
- Mypy version used: mypy 1.15.0 (compiled: yes)
- Mypy command-line flags: none
- Mypy configuration options from
mypy.ini(and other config files): none - Python version used: 3.11.11
I reproduced this with mypy version 1.14