Remove 4 C API private trashcan functions which were only kept for
the backward compatibility of the stable ABI with Python 3.8 and
older, since the trashcan API was not usable with the limited C API
on Python 3.8 and older. The trashcan API was excluded from the
limited C API in Python 3.9.
Removed functions:
* _PyTrash_deposit_object()
* _PyTrash_destroy_chain()
* _PyTrash_thread_deposit_object()
* _PyTrash_thread_destroy_chain()
The trashcan C API was never usable with the limited C API, since old
trashcan macros accessed directly PyThreadState members like
"_tstate->trash_delete_nesting", whereas the PyThreadState structure
is opaque in the limited C API.
Exclude also the PyTrash_UNWIND_LEVEL constant from the C API.
The trashcan C API was modified in Python 3.9 by commit
38965ec541 and in Python 3.10 by commit
ed1a5a5bac to hide implementation
details.
* Remove struct _node from the stable ABI list
This struct was removed along with the old parser in Python 3.9 (PEP 617)
* Stable ABI list: Use the public name "PyFrameObject" rather than "_frame"
* Ensure limited API doesn't contain private names
Names prefixed by an underscore are private by definition.
* Add a blurb
Py_FrozenMain was added to the Limited C API in [bpo-42591]() (3.10.0a4);
but to fix that issue it would be enough to add it to the regular C API.
The function is undocumented, tests were added very recently ([bpo-44131]()),
and most importantly, it is not present in all builds of Python, as
the linker sometimes omits it as unused.
It should be added back when these issues are fixed.
Note that this does not affect Python's regular C API.