[Python-Dev] What do PyAPI_FUNC & PyAPI_DATA mean? (original) (raw)

"Martin v. Löwis" martin at v.loewis.de
Tue Apr 24 09:31:20 CEST 2012

Am 23.04.2012 15:05, schrieb Kristján Valur Jónsson:

IMHO, we are much too generous at applying this to almost whatever gets exposed between .c files. I have created something called the "restricted" api for our custom python27.dll where I use different macros (PyAPIRFUNC, pyAPIRDATA) to mean that things aren't exported for "restricted" builds. We use it to remove some of the easier access points to the dll for hackers to exploit.

Also, once declared exported this way, things become more bothersome to remove again, since once could always argue that someone out there is using these thigns.

For this, PyAPI_FUNC doesn't really matter. A symbol that is listed in the header file is available on Unix even without such a declaration, so listing it in the public header file is already the step that makes it public, not specifying it as PyAPI_FUNC.

I agree that too much API is public, but the right approach is to rename such API to _Py*, indicating to users that we don't want them to use it. For existing API, that's tricky; for new API, I think it should be private by default.

See also PEP 384.

Regards, Martin

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