inspect.signature should use FORWARDREF annotation_format for python 3.14+

[93578237]

On python 3.14 it fails at least here:
​https://github.com/django/django/blob/13299a6203f4bc3e5b2552c96a51ff2b15da3c43/django/contrib/auth/__init__.py#L43

import typing as t

from django.contrib.auth.backends import ModelBackend

if t.TYPE_CHECKING:
    from django.http import HttpRequest

    from testproject.models import User as UserModel


class AuthenticationBackend(ModelBackend):
    def authenticate(
        self,
        request: HttpRequest | None = None,
        username: str | None = None,
        password: str | None = None,
        **kwargs: t.Any,
    ) -> UserModel | None: ...

Maybe a new function signature should be added to utils/inspect.py

[Jacob Walls]

Thanks, looks like we missed a few in #36696 and #36712.

We need to audit uses of inspect.signature with the possible exception of cases where we are only inspecting Django's own signatures e.g. deprecate_posargs(), but even that is debatable since there is ​motion toward making gradual explorations of incremental type annotations in Django.

[93578237]

Would it be possible to backport it to 5.x? I encountered that on 5.2.x.

My proposal is to add the inspect function that passes an additional annotation_format kwarg if its PY_314

[Jacob Walls]

That decision will be made during review, but I'll note that prior related tickets were backported to 5.2.x.

[93578237]

I can work on it. Should it be fixed in-place or by reusing a separate function?

[Jacob Walls]

A new function is appealing, since the last time we touched this, we ended up with bloat like this:

    # As the annotations are not used in any case, inspect the signature with
    # FORWARDREF to leave any deferred annotations unevaluated.
    if PY314:
        signature = inspect.signature(
            func, annotation_format=annotationlib.Format.FORWARDREF
        )
    else:
        signature = inspect.signature(func)

Now that we're aware of the multiple call sites that matter, DRY-ing this out makes sense to me.

Thanks for volunteering.

[Jacob Walls <jacobtylerwalls@…>]

In 56ed37e1:

Fixed #36903 -- Fixed further NameErrors when inspecting functions with deferred annotations.

Provide a wrapper for safe introspection of user functions on Python 3.14+.

Follow-up to 601914722956cc41f1f2c53972d669ddee6ffc04.

[Jacob Walls <jacobtylerwalls@…>]

In deac58e:

[6.0.x] Fixed #36903 -- Fixed further NameErrors when inspecting functions with deferred annotations.

Provide a wrapper for safe introspection of user functions on Python 3.14+.

Follow-up to 601914722956cc41f1f2c53972d669ddee6ffc04.
Backport of 56ed37e17e5b1a509aa68a0c797dcff34fcc1366 from main.

[Jacob Walls <jacobtylerwalls@…>]

In a4999ef:

[5.2.x] Fixed #36903 -- Fixed further NameErrors when inspecting functions with deferred annotations.

Provide a wrapper for safe introspection of user functions on Python 3.14+.

Follow-up to 601914722956cc41f1f2c53972d669ddee6ffc04.
Backport of 56ed37e17e5b1a509aa68a0c797dcff34fcc1366 from main.