Cython

====================

Features added
--------------

* The ``cythonize`` and ``cython`` commands have a new option ``-M`` / ``--depfile``
to generate ``.dep`` dependency files for the compilation unit. This can be used
by external build tools to track these dependencies.
The ``cythonize`` option was already available in Cython :ref:`0.29.27`.
Patches by Evgeni Burovski and Eli Schwartz. (Github issue :issue:`1214`)

Bugs fixed
----------

* ``const`` fused types could not be used with memory views.
Patch by Thomas Vincent. (Github issue :issue:`1772`)

* ``wstr`` usage was removed in Python 3.12 and later (PEP-623).
(Github issue :issue:`5145`)

* A type check assertion for Cython functions failed in debug Python builds.
(Github issue :issue:`5031`)

* Fixed various compiler warnings.
Patches by Lisandro Dalcin et al. (Github issues :issue:`4948`, :issue:`5086`)

* Fixed error when calculating complex powers of negative numbers.
(Github issue :issue:`5014`)

* Corrected a small mis-formatting of exception messages on Python 2.
(Github issue :issue:`5018`)

* The ``PyUnicode_AsUTF8AndSize()`` C-API function was missing from the CPython declarations.
(Github issue :issue:`5163`)

* A performance problem in the compiler was resolved when nesting conditional expressions.
(Github issue :issue:`5197`)

* Test suite problems with recent NumPy and CPython versions were resolved.
(Github issues :issue:`5183`, :issue:`5190`)

Other changes
-------------

* The undocumented, untested and apparently useless syntax
``from somemodule cimport class/struct/union somename`` was deprecated
in anticipation of its removal in Cython 3. The type
modifier is not needed here and a plain ``cimport`` of the name will do.
(Github issue :issue:`4905`)

* Properly disable generation of descriptor docstrings on PyPy since they cause crashes.
It was previously disabled, but only accidentally via a typo.
Patch by Matti Picus. (Github issue :issue:`5083`)

* The ``cpow`` directive of Cython 3.0 is available as a no-op.
(Github issue :issue:`5016`)

====================

Bugs fixed
----------

* Revert "Using memoryview typed arguments in inner functions is now rejected as unsupported."
Patch by David Woods. (Github issue :issue:`4798`)

* ``from module import *`` failed in 0.29.31 when using memoryviews.
Patch by David Woods. (Github issue :issue:`4927`)

====================

Features added
--------------

* A new argument ``--module-name`` was added to the ``cython`` command to
provide the (one) exact target module name from the command line.
Patch by Matthew Brett and h-vetinari. (Github issue :issue:`4906`)

* A new keyword ``noexcept`` was added for forward compatibility with Cython 3.
Patch by David Woods. (Github issue :issue:`4903`)

Bugs fixed
----------

* Use ``importlib.util.find_spec()`` instead of the deprecated ``importlib.find_loader()``
function when setting up the package path at import-time.
Patch by Matti Picus. (Github issue :issue:`4764`)

* Require the C compiler to support the two-arg form of ``va_start``
on Python 3.10 and higher.
Patch by Thomas Caswell. (Github issue :issue:`4820`)

* Make ``fused_type`` subscriptable in Shadow.py.
Patch by Pfebrer. (Github issue :issue:`4842`)

* Fix the incorrect code generation of the target type in ``bytearray`` loops.
Patch by Kenrick Everett. (Github issue :issue:`4108`)

* Atomic refcounts for memoryviews were not used on some GCC versions by accident.
Patch by Sam Gross. (Github issue :issue:`4915`)

* Silence some GCC ``-Wconversion`` warnings in C utility code.
Patch by Lisandro Dalcin. (Github issue :issue:`4854`)

* Tuple multiplication was ignored in expressions such as ``[*(1,) * 2]``.
Patch by David Woods. (Github issue :issue:`4864`)

* Calling ``append`` methods on extension types could fail to find the method
in some cases.
Patch by David Woods. (Github issue :issue:`4828`)

* Ensure that object buffers (e.g. ``ndarray[object, ndim=1]``) containing
``NULL`` pointers are safe to use, returning ``None`` instead of the ``NULL``
pointer.
Patch by Sebastian Berg. (Github issue :issue:`4859`)

* Using memoryview typed arguments in inner functions is now rejected as unsupported.
Patch by David Woods. (Github issue :issue:`4798`)

* Compilation could fail on systems (e.g. FIPS) that block MD5 checksums at runtime.
(Github issue :issue:`4909`)

* Experimental adaptations for the CPython "nogil" fork was added.
Note that there is no official support for this in Cython 0.x.
Patch by Sam Gross. (Github issue :issue:`4912`)

====================

Bugs fixed
----------

* The GIL handling changes in 0.29.29 introduced a regression where
objects could be deallocated without holding the GIL.
(Github issue :issue:`4796`)

====================

Features added
--------------

* Avoid acquiring the GIL at the end of nogil functions.
This change was backported in order to avoid generating wrong C code
that would trigger C compiler warnings with tracing support enabled.
Backport by Oleksandr Pavlyk. (Github issue :issue:`4637`)

Bugs fixed
----------

* Function definitions in ``finally:`` clauses were not correctly generated.
Patch by David Woods. (Github issue :issue:`4651`)

* A case where C-API functions could be called with a live exception set was fixed.
Patch by Jakub Kulík. (Github issue :issue:`4722`)

* Pickles can now be exchanged again with those generated from Cython 3.0 modules.
(Github issue :issue:`4680`)

* Cython now correctly generates Python methods for both the provided regular and
reversed special numeric methods of extension types.
Patch by David Woods. (Github issue :issue:`4750`)

* Calling unbound extension type methods without arguments could raise an
``IndexError`` instead of a ``TypeError``.
Patch by David Woods. (Github issue :issue:`4779`)

* Calling unbound ``.__contains__()`` super class methods on some builtin base
types could trigger an infinite recursion.
Patch by David Woods. (Github issue :issue:`4785`)

* The C union type in pure Python mode mishandled some field names.
Patch by Jordan Brière. (Github issue :issue:`4727`)

* Allow users to overwrite the C macro ``_USE_MATH_DEFINES``.
Patch by Yuriy Chernyshov. (Github issue :issue:`4690`)

* Improved compatibility with CPython 3.10/11.
Patches by Thomas Caswell, David Woods.
(Github issues :issue:`4609`, :issue:`4667`, :issue:`4721`, :issue:`4730`, :issue:`4777`)

* Docstrings of descriptors are now provided in PyPy 7.3.9.
Patch by Matti Picus. (Github issue :issue:`4701`)

====================

Bugs fixed
----------

* Due to backwards incompatible changes in CPython 3.11a4, the feature flags
``CYTHON_FAST_THREAD_STATE`` and ``CYTHON_USE_EXC_INFO_STACK`` are now disabled
in Python 3.11 and later. They are enabled again in Cython 3.0.
Patch by David Woods. (Github issue :issue:`4610`)

* A C compiler warning in older PyPy versions was resolved.
Patch by Matti Picus. (Github issue :issue:`4236`)