Issue 21354: PyCFunction_New no longer exposed by python DLL breaking bdist_wininst installers

Python 3.3 and earlier have in methodobject.c:

/* PyCFunction_New() is now just a macro that calls PyCFunction_NewEx(),
   but it's part of the API so we need to keep a function around that
   existing C extensions can call.
*/

#undef PyCFunction_New
PyAPI_FUNC(PyObject *) PyCFunction_New(PyMethodDef *, PyObject *);

which means PyCFunction_New is exported from the DLL.  Python 3.4 does not have this (which seems a bug in its own right given the comment in 3.3 and earlier) but PC/bdist_wininst/install.c has code that attempts to dynamically load this function from the DLL and fails, causing 3rd party installers to fail.

Assuming the removal of this API was intentional so the problem is that install.c needs to be updated, the following patch fixes the issue.

This is apparently because mismanagement of issue #15422.

Andrew, you did the commits, can you restore the PyAPI_FUNC declaration?

(while none of PyCFunction_New and PyCFunction_NewEx are documented, they are part of the stable ABI - the python3.def file -, so removing the API is presumably a bug, not a feature)

Ok, I'll take a look. Sorry, probably I've missed python3.def file.

This is still not fixed.

Sorry for the "mismanagement", I probably didn't check again after the final resolution.

Still not fixed!  This has been marked as "release blocker" for most of a year.  Should I just apply the patch?

Perhaps Steve can confirm that the patch is right.

I'm sorry.
The patch is correct from my perspective if we want to make bdist_install just working.
Or as an option I can restore PyCFunction_New function declaration.

What do you prefer?

As Andrew says, the patch is fine for the bug, but the PyCFunction_New function is certainly part of the stable ABI and needs to be restored.

Steve, Andrew, does either of you want to take care of this or shall I give it a shot?  I'm figuring on using the patch here and re-adding PyCFunction_New as it had been.

Will do up to weekend.

—
Sent from Mailbox

On Mon, Apr 13, 2015 at 4:58 PM, Zachary Ware <report@bugs.python.org>
wrote:

> Zachary Ware added the comment:
> Steve, Andrew, does either of you want to take care of this or shall I give it a shot?  I'm figuring on using the patch here and re-adding PyCFunction_New as it had been.
> ----------
> _______________________________________
> Python tracker <report@bugs.python.org>
> <http://bugs.python.org/issue21354>
> _______________________________________

New changeset 69951573cb0e by Andrew Svetlov in branch '3.4':
Issue #21354: PyCFunction_New function is exposed by python DLL again.
https://hg.python.org/cpython/rev/69951573cb0e

Fixed. Sorry for long delay.

assignee: asvetlov
versions: + Python 3.4, Python 3.5
nosy: + asvetlov, larry, pitrou

messages: + msg217194
stage: needs patch