This issue implements a proposal related to PEP-489 and PEP-630.

Decision:

• Add Py_tp_token slot and PyType_GetBaseByToken function capi-workgroup/decisions#34

TODO:

• Implement the feature
• Use it in _PyStgInfo_FromType_NoState() in _ctypes.c
• Ensure no performance regression in PyType_GetModuleByDef() and other functions affected by this feature on Windows PGO builds

TODO (optional):

• Replace PyType_GetModuleByDef() in defdict_or() (_collectionsmodule.c)
• Replace _PyType_GetModuleByDef2() in _decimal.c
• Remove _PyType_GetModuleByDef2()

Has this already been discussed elsewhere?

I have already discussed this feature proposal on Discourse

Links to previous discussion of this feature:

• Better support for type checking encukou/abi3#19
• https://discuss.python.org/t/55598

Linked PRs

• gh-124153: Introduce PyType_GetBaseByToken function (PoC) #121079
• gh-124153: Implement PyType_GetBaseByToken() and Py_tp_token slot #124163
• gh-124153: Remove _PyType_GetModuleByDef2 private function #124261
• gh-124153: Clean up workarounds for PyType_GetBaseByToken() performance #124323
• gh-124153: Fix unstable optimization of PyType_GetBaseByToken() and friends #124488
• gh-124153: Add Py_tp_token support to xxlimited module #141644