Use Py_SET_SIZE() function

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Replace "Py_TYPE(obj)=type;" with "Py_SET_SIZE(obj, type);". The
Py_SET_SIZE() was added to Python 3.9: copy pythoncapi_compat.h
header to src/object/. The file comes from the project:
https://github.com/pythoncapi/pythoncapi_compat

On Python 3.10, Py_SET_SIZE() should now be used rather than using
Py_TYPE() as an l-value:
https://docs.python.org/dev/c-api/structures.html#c.Py_TYPE

Context: https://bugs.python.org/issue39573

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See also #329

[stefanseefeld]

This looks like a duplicate of #328, doesn't it ?

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This looks like a duplicate of #328, doesn't it ?

PR #328 replaces obj->ob_type with Py_TYPE(). It doesn't need pythoncapi_compat.h, since Py_TYPE() exists since Python 2.6.

[stefanseefeld]

Aren't you referring to #329 instead ?

[vstinner]

This looks like a duplicate of #328, doesn't it ?

Oh wait, ignore my previous comment. I wrote 2 PRs and I didn't notice that you're a talking about a 3rd PR.

Yes, #328 is the same fix, but it doesn't use pythoncapi_compat.h. I propose to use it to avoid having to reimplemented the compatibility layer for old Python versions:

#if PY_VERSION_HEX < 0x030900A4
#  define Py_SET_TYPE(obj, type) ((Py_TYPE(obj) = (type)), (void)0)
#  define Py_SET_SIZE(obj, size) ((Py_SIZE(obj) = (size)), (void)0)
#endif

pythoncapi_compat.h uses static inline functions rather than macros.

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Fedora uses a downstream patch to fix issue: https://src.fedoraproject.org/rpms/boost/blob/master/f/boost-1.73-python3.10.patch Copy of the boost specfile:

# https://bugzilla.redhat.com/show_bug.cgi?id=1896382
# https://github.com/boostorg/python/issues/325
Patch93: boost-1.73-python3.10.patch

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APPVEYOR_BUILD_WORKER_IMAGE=Visual Studio 2019

This job failed because it failed to locate the C++ compiler, whereas the two other AppVeyor jobs passed:

set FARGS=--log=summary --log=output --log=actions --log=commands --with-boost-include=%BOOST_PREFIX% target.arch=%ARCH% cxx.name=msvc cxx.version=%MSVC%
faber %FARGS% config || type config.log
Error: C:\Python36-x64\lib\site-packages\faber\tools\cxx.py:64: no C++ compiler found matching <set cxx.name=msvc cxx.version=16.7.4 target.arch=x86_64>.
faber %FARGS% -j8
Error: C:\Python36-x64\lib\site-packages\faber\tools\cxx.py:64: no C++ compiler found matching <set cxx.name=msvc cxx.version=16.7.4 target.arch=x86_64>.
Command exited with code 1

[stefanseefeld]

Closed as obsolete.