Python headers are being reorganized to clarify what's public, specific to CPython or "internal". See issues bpo-35134 (Add a new Include/cpython/ subdirectory) and bpo-35081 (Move internal headers to Include/internal/).

Problem: the _testcapi module designed to only test the *public* API. Functions tested by _testcapi cannot be made internal.

I propose to add a new _testinternalcapi module reserved to test internal APIs.

Attached PR implements this idea: it makes _Py_GetConfigsAsDict() private and moves _testcapi.get_configs() to _testinternalcapi.get_configs().

I listed DLL exports in the Visual Studio Command Prompt:

dumpbin /exports \vstinner\python\master\PCbuild\amd64\python38_d.dll > \vstinner\python\exports.txt

To make sure that I don't mess with commands, I started with a fresh Git checkout using:

git clean -fdx
PCbuild\build.bat -d -p x64 -e

Good news: using PR 12853, exports.txt is exactly the same file (I expected memory address to change, but nope, they are the same). My change doesn't introduce any new symbol. See attached exports.txt file. By the way, there is no symbol which contains "PyInit" nor "Py_pickle_init" in DLL exports.

New changeset 5c75f37d473140f0e0b7d9bf3a8c08343447ded1 by Victor Stinner in branch 'master':
bpo-36635: Change pyport.h for Py_BUILD_CORE_MODULE define (GH-12853)
https://github.com/python/cpython/commit/5c75f37d473140f0e0b7d9bf3a8c08343447ded1

New changeset 23bace26ec265557697cf3b578b361c178070cd5 by Victor Stinner in branch 'master':
bpo-36635: Add _testinternalcapi module (GH-12841)
https://github.com/python/cpython/commit/23bace26ec265557697cf3b578b361c178070cd5

New changeset 574913479f26b5ff48827861bce68281be01d16e by Victor Stinner in branch 'master':
bpo-36635, bpo-36696: Fix setup.py on AIX (GH-12922)
https://github.com/python/cpython/commit/574913479f26b5ff48827861bce68281be01d16e