If the macro is deprecated, please provide an detailed explanation how to port existing C code to the new C API, in What's New In Python 3.X (version where the macro is deprecated, Python 3.11 if I understood correctly).
Also, is there a way to write a single code base working on Python 3.6-Python 3.11? It seems like mypy uses macros to support Python < 3.8 and Python >= 3.8: #if PY_MAJOR_VERSION >= 3 && PY_MINOR_VERSION >= 8 #define CPy_TRASHCAN_BEGIN(op, dealloc) Py_TRASHCAN_BEGIN(op, dealloc) #define CPy_TRASHCAN_END(op) Py_TRASHCAN_END #else #define CPy_TRASHCAN_BEGIN(op, dealloc) Py_TRASHCAN_SAFE_BEGIN(op) #define CPy_TRASHCAN_END(op) Py_TRASHCAN_SAFE_END(op) A search in PyPI top 1000 project gives me 8 projects (I was too lazy to check the full top 5000). It would be great to help these projects (propose pull requests) to migrate to the new C API. (*) pyrsistent-0.18.0.tar.gz > ./pvectorcmodule.c: Py_TRASHCAN_SAFE_BEGIN(self); > ./pvectorcmodule.c: Py_TRASHCAN_SAFE_BEGIN(self); (*) PyGObject-3.40.1.tar.gz > ./gi/pygi-resulttuple.c: Py_TRASHCAN_SAFE_BEGIN (self) (*) pycurl-7.44.1.tar.gz > ./src/easy.c: Py_TRASHCAN_SAFE_BEGIN(self); > ./src/multi.c: Py_TRASHCAN_SAFE_BEGIN(self); > ./src/share.c: Py_TRASHCAN_SAFE_BEGIN(self); (*) mypy-0.910.tar.gz > ./mypyc/lib-rt/CPy.h: --- #if PY_MAJOR_VERSION >= 3 && PY_MINOR_VERSION >= 8 #define CPy_TRASHCAN_BEGIN(op, dealloc) Py_TRASHCAN_BEGIN(op, dealloc) #define CPy_TRASHCAN_END(op) Py_TRASHCAN_END #else #define CPy_TRASHCAN_BEGIN(op, dealloc) Py_TRASHCAN_SAFE_BEGIN(op) #define CPy_TRASHCAN_END(op) Py_TRASHCAN_SAFE_END(op) #endif --- (*) pypi-top-1000_2021-08-17/multidict-5.1.0.tar.gz > ./multidict/_multidict.c: Py_TRASHCAN_SAFE_BEGIN(self); (*) pypi-top-1000_2021-08-17/immutables-0.16.tar.gz > ./immutables/_map.c: Py_TRASHCAN_SAFE_BEGIN(self) > ./immutables/_map.c: Py_TRASHCAN_SAFE_BEGIN(self) > ./immutables/_map.c: Py_TRASHCAN_SAFE_BEGIN(self) (*) guppy3-3.1.1.tar.gz > ./src/sets/nodeset.c: Py_TRASHCAN_SAFE_BEGIN(v) > ./src/sets/immnodeset.c: Py_TRASHCAN_SAFE_BEGIN(it) > ./src/sets/immnodeset.c: Py_TRASHCAN_SAFE_BEGIN(v) > ./src/heapy/hv.c: Py_TRASHCAN_SAFE_BEGIN(v) > ./src/heapy/classifier.c: Py_TRASHCAN_SAFE_BEGIN(op) > ./src/heapy/nodegraph.c: Py_TRASHCAN_SAFE_BEGIN(v) > ./src/heapy/hv_cli_rel.c: Py_TRASHCAN_SAFE_BEGIN(op) (*) frozendict-2.0.6.tar.gz > <many files using the macro> Victor On Tue, Aug 17, 2021 at 12:02 PM Łukasz Langa <luk...@langa.pl> wrote: > > Hi everybody, > I'd like to revive this thread as I feel like we have to do something here > but some consensus is needed first. > > To recap, the current state of things is as follows: > - in March 2000 (d724b23420f) Christian Tismer contributed the "trashcan" > patch that added Py_TRASHCAN_SAFE_BEGIN and Py_TRASHCAN_SAFE_END macros which > allow destroying nested objects non-recursively. > - in May 2019 (GH-11841 of BPO-35983) Antoine Pitrou merged a change by > Jeroen Demeyer which made Py_TRASHCAN_SAFE_BEGIN/END (unintentionally?) > backwards incompatible; this was released in Python 3.8.0. > - by the way, GH-11841 introduced a new pair of macros (because they have > different signatures) called simply Py_TRASHCAN_BEGIN and Py_TRASHCAN_END. > - by that time there was already a follow-up PR open (GH-12607) to improve > backwards compatibility of the macros, as well as introduce tests for them; > this was never merged. > - in Feb 2020 (0fa4f43db08) Victor Stinner removed the trashcan mechanism > from the limited C API (note: not ABI, those are macros) since it accesses > fields of structs not exposed in the limited C API; this was released in > Python 3.9.0. > - in May 2020 Irit noticed that the backwards incompatibility (BPO-40608) > causes segfaults for C API code that worked fine with Python 3.7. Using the > new macros requires code changes but doesn't crash. > > Now, there are a couple of things we can do here: > Option 1: Finish GH-12607 to fix the old macros, keeping in mind this will > restore compatibility lost with Python 3.8 - 3.10 only for users of 3.11+ > Option 2: Review and merge GH-20104 that reverts the macro changes that make > old client code segfault -- unclear what else this needs and again, that > would only fix it for users of 3.11+ > Option 3: Abandon GH-12607 and GH-20104, instead declaring the old macros > deprecated for 3.11 and remove them in 3.13 > > I personally agree with Irit, voting +1 for Option 3 since the old macros > were soft-deprecated already by introducing new macros in 3.8, and more > importantly made incompatible with pre-3.8 usage. > > Let's talk on how to proceed. > > - Ł > > > > On 26 Apr 2021, at 23:55, Irit Katriel via Python-Dev <python-dev@python.org> > wrote: > > > Re https://bugs.python.org/issue40608. > > I think it will be an act of kindness to deprecate Py_TRASHCAN_SAFE_BEGIN/END > in 3.10 and tell people to use Py_TRASHCAN_BEGIN/END instead. > > TL;DR: There was a change in 3.8 that introduced the latter while leaving the > former for backwards compatibility, but also inadvertently breaking them. > This is not an easy bug to deal with in the wild, we found it because we have > a unit test in our codebase referencing https://bugs.python.org/issue16602. > A deprecation note pointing to the new macros would have made it easier. > > Is there any reason not to deprecate the old macros? > > Irit > _______________________________________________ > Python-Dev mailing list -- python-dev@python.org > To unsubscribe send an email to python-dev-le...@python.org > https://mail.python.org/mailman3/lists/python-dev.python.org/ > Message archived at > https://mail.python.org/archives/list/python-dev@python.org/message/LWP6MOLP5UW2TH3MROZQK4N64SX35N2B/ > Code of Conduct: http://python.org/psf/codeofconduct/ > > > _______________________________________________ > Python-Dev mailing list -- python-dev@python.org > To unsubscribe send an email to python-dev-le...@python.org > https://mail.python.org/mailman3/lists/python-dev.python.org/ > Message archived at > https://mail.python.org/archives/list/python-dev@python.org/message/TH4NILYOG3ZJO7SCCF6ECBLXJDDFJKS4/ > Code of Conduct: http://python.org/psf/codeofconduct/ -- Night gathers, and now my watch begins. It shall not end until my death. _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-le...@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/7Z75RFQUEGE6AAGVQSEWGWOA5TFA64UQ/ Code of Conduct: http://python.org/psf/codeofconduct/
