[Python-Dev] Preventing 1.5 extensions crashing under 1.6/2.0 Python (original) (raw)

Guido van Rossum guido@beopen.com
Wed, 02 Aug 2000 18🔞04 -0500

> But-I-doubt-anyone-will-release-extension-modules-for-1.6-anyway ly,

Yes indeed once the story of 1.6 and 2.0 is out I expect folks will skip 1.6. For example, if your win32 stuff is not ported then Python 1.6 is not usable on Windows/NT.

I expect to be releasing a 1.6 Windows installer -- but I can't control Mark Hammond. Yet, it shouldn't be hard for him to create a 1.6 version of win32all, should it?

Change the init function name to a new name PythonExtensionInit say. Pass in the API version for the extension writer to check. If the version is bad for this extension returns without calling any python functions. Add a return code that is true if compatible, false if not. If compatible the extension can use python functions and report and problems it wishes.

int PythonExtensionInitXXX( int invokingpythonapiversion ) { if( invokingpythonapiversion != PYTHONAPIVERSION ) { /* python will report that the module is incompatible */ return 0; } /* setup module for XXX ... */ /* say this extension is compatible with the invoking python */ return 1; } All 1.5 extensions fail to load on later python 2.0 and later. All 2.0 extensions fail to load on python 1.5. All new extensions work only with python of the same API version. Document that failure to setup a module could mean the extension is incompatible with this version of python. Small code change in python core. But need to tell extension writers what the new interface is and update all extensions within the python CVS tree.

I sort-of like this idea -- at least at the +0 level.

I would choose a shorter name: PyExtInit_XXX().

Could you (or someone else) prepare a patch that changes this? It would be great if the patch were relative to the 1.6 branch of the source tree; unfortunately this is different because of the ANSIfication.

Unfortunately we only have two days to get this done for 1.6 -- I plan to release 1.6b1 this Friday! If you don't get to it, prepare a patch for 2.0 would be the next best thing.

--Guido van Rossum (home page: http://www.pythonlabs.com/~guido/)