[PyUP] Update cython to 3.2.0

[pyup-bot]

This PR updates Cython from 0.29.24 to 3.2.0.

Changelog

3.2.0

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

(Complete changelog for the 3.2.0 release, including pre-releases.)

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

* Builtin exception types are now inferred.
(Github issue :issue:`6908`)

* The list of known, inferred and optimised Python builtins was updated.
`range` is now considered a type. `ascii`, `bin`, `format`, `hex`, `oct` were added as functions.
(Github issue :issue:`6931`)

* The f-string syntax was extended according to PEP-701.
(Github issue :issue:`5452`)

* t-strings are implemented according to PEP-750.  The implementation backports the template classes
but prefers existing backports if installed separately.
(Github issue :issue:`6811`)

* Unknown return type annotations with `->` are no longer rejected but produce warnings.
This allows better integration with Python type hints that are not always usable for Cython.
``-> None``  is also allowed now.
Patch by jpe.  (Github issue :issue:`6946`)

* The runtime Python dispatch for fused functions is substantially faster.
(Github issues :issue:`1385`, :issue:`6996`)

* Freelists (via cdef class decorator and for internally used types such as ``async``)
are now also used in the Limited API and with extension type specs enabled.
(Github issue :issue:`7151`)

* Module imports now quickly check for an already imported module to speed up reimports.
Patch by Lysandros Nikolaou.  (Github issue :issue:`7035`)

* Type checks on PEP-604 union types (`int | None`) are optimised into separate checks.
(Github issue :issue:`6935`)

* Assignments to the PEP-604 union type `float | None` allow any suitable Python number as input
and convert it to a Python `float` automatically.
(Github issue :issue:`5750`)

* Item type inference was improved for looping over literals.
(Github issue :issue:`6912`)

* Looping over literal sequences and strings now uses efficient C array looping if possible.
(Github issue :issue:`6926`)

* Releasing the GIL from an unknown lock state is more efficient.
(Github issue :issue:`6847`)

* ``cython.critical_section(PyMutex)`` now works, as with Python objects.
(Github issue :issue:`6847`)

* ``bool(c_int/float/ptr)`` avoid passing through Python objects.
(Github issue :issue:`7015`)

* Variables assigned inside of ``prange`` loops can now be initialised outside of the loop.
(Github issue :issue:`7178`)

* Unused exceptions in ``except`` clauses are detected in some more cases to avoid their normalisation.
(Github issue :issue:`7021`)

* Mixed operations on C integers with Python ints use less code and are more streamlined for Py3.12+.
(Github issue :issue:`7244`)

* Some object constants are now marked as ``immortal`` to speed up their reference counting
in recent CPython versions.  This can be configured with the ``CYTHON_IMMORTAL_CONSTANTS`` C macro.
(Github issue :issue:`7118`)

* Further improvements were made to reduce the size of the resulting extension modules.
(Github issue :issue:`6983`, :issue:`7199`, :issue:`7220`, :issue:`7238`,
:issue:`7255`, :issue:`7265`)

* Several improvements were made in freethreaded Python code.
(Github issues :issue:`6936`, :issue:`6939`, :issue:`6949`, :issue:`6984`,
:issue:`7011`, :issue:`7066`, :issue:`7114`, :issue:`7200`)

* Several improvements were made for the Limited API.
(Github issues :issue:`6959`, :issue:`6991`)

* Several improvements were made for the GraalPython support.
Patch by Michael Šimáček.  (Github issue :issue:`7074`)

* Some GIL-safe C-API wrappers were added to the libc/libcpp declarations.
(Github issue :issue:`6829`, :issue:`6993`)

* String and number constants use less storage space in the module.
(Github issues :issue:`6971`, :issue:`6978`, :issue:`6986`)

* The managed dict/weakref support in CPython 3.12+ is used for internal types
to benefit from future CPython optimisations here.
(Github issue :issue:`6891`)

* Using ``NaN`` as exception return value is supported.
(Github issues :issue:`6900`, :issue:`6903`)

* Declarations for C++ condition variables were added.
(Github issue :issue:`6836`)

* The annotated source HTML page shows alternating +/− markers to open/close lines.
Patch by Kamil Monicz.  (Github issue :issue:`7099`)

* ``cython --embed`` gained a new option ``--embed-modules=…`` to list further extension modules
that will be statically linked into the generated extension module, to get them initialised
on application start.
(Github issue :issue:`2849`)

* The ``setup.py`` script of Cython now allows passing the desired Limited API version
like ``--cython-limited-api=3.11``.
(Github issue :issue:`7228`)

* Unicode 16.0.0 is used to parse identifiers.
(Github issue :issue:`6836`)

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

* Special float exception values could generate invalid C code.
(Github issues :issue:`6900`, :issue:`6903`)

* References to the Python ``bool`` type could generate invalid C code.
(Github issue :issue:`6902`)

* Using ``cython.pymutex`` in an extension type declared as ``public`` or ``api``
generated invalid C code missing the required ``PyMutex`` declarations.
(Github issues :issue:`6992`, :issue:`6995`)

* Cython's type sharing across modules suffered from race conditions if multiple modules
tried to initialise and share their types concurrently.  This is due to an underlying
CPython issue and cannot easily be worked around completely.  In the common case that
module dicts are plain Python dict objects, however, Cython now uses a ``.setdefault()``
equivalent for thread-safe type sharing.
See https://github.com/python/cpython/issues/137422
(Github issue :issue:`7076`)

* Cython incorrectly called ``PyList_GetItemRef()`` in PyPy and GraalPython before Py3.13.
(Github issue :issue:`7269`)

* Iterating over temporary memoryviews could crash Cython.
(Github issue :issue:`7005`)

* Type casts on constants as part of numeric expressions could crash Cython.
(Github issue :issue:`6779`)

* Long code bodies in ``with`` statements could crash Cython.
(Github issue :issue:`7122`)

* Vectorcalls could use needless temp assignments for ``self``.
(Github issue :issue:`6909`)

* Indexing ``bytes`` failed to optimise in some cases.
(Github issue :issue:`6997`)

* Optimised C integer formatting in f-strings failed to apply to typedef types.
(Github issue :issue:`7170`)

* In auto-pickling, trying to unpickle an object that has no ``__dict__`` from object pickle data
that includes instance dict state is now an error.
(Github issue :issue:`7222`)

* The type objects of heap types were not always correctly decrefed on deallocation.
(Github issue :issue:`7145`)

* Pure mode type aliases like ``p_int`` or ``ulong`` leaked into some C type contexts,
risking to conflict with user declarations.
(Github issues :issue:`6922`, :issue:`6339`)

* Boolean (emptyness) tests on builtin containers could fail to handle (unlikely) errors.
(Github issue :issue:`7090`)

* The return type of ``bytes.join()`` was sometimes inferred as plain ``object``.
(Github issue :issue:`6987`)

* Type inference could fail to understand ``prange()`` arguments.
(Github issue :issue:`6974`)

* ``embedsignatures`` failed if ``lambda`` was used in function default arguments.
(Github issue :issue:`6880`)

* An internal C function was not marked as ``static`` and leaked a linker symbol.
(Github issue :issue:`6957`)

* ``PyType_FromModuleAndSpec`` was incorrectly used in Limited API code before Py3.10.
(Github issue :issue:`7181`)

* Conversion code for memoryview dtypes from and to Python objects generated C warnings about
incorrect ``const`` / non-``const``  casting code.
(Github issue :issue:`7219`)

* Cython's tools and frontend scripts now use ``python3``  instead of just ``python``
in their shebang line.
Patch by Matti Picus.  (Github issue :issue:`7053`)

* Extension arguments defined for the shared code module were ignored in ``cythonize()``.
(Github issue :issue:`7251`)

* Failures while following package attributes in ``import pkg.module as …`` were not handled.

* Trying to instantiate internal types used by Cython is now prohibited.
(Github issue :issue:`7263`)

* The ``setup.py`` script in the ``Demos/`` subdirectory failed to build.
(Github issue :issue:`7228`)

* The ``cygdb`` program failed to work with virtualenvs on Windows.
Patch by Merlin.  (Github issue :issue:`7268`)

* Includes all fixes as of Cython 3.1.6.

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

* Some lesser used platforms (Windows ARM/i686, macOS x86_64, Linux i686, musllinux)
now use Py3.9 abi3 binary wheels instead of Python version specific wheels.
We also added an abi3 wheel for armv7l.
(Github issues :issue:`7227`, :issue:`7248`, :issue:`7250`)

* Usages of `Py_TPFLAGS_HAVE_FINALIZE` were removed.  The constant remains available as cimport from
``cpython.object`` for legacy reasons.
(Github issue :issue:`6423`)

3.2.0b3

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

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

* Using ``cython.pymutex`` in an extension type declared as ``public`` or ``api``
generated invalid C code missing the required ``PyMutex`` declarations.
(Github issues :issue:`6992`, :issue:`6995`)

* 3.2.0b2 generated incorrect pointer casts in the ``cimport`` importing code.
(Github issue :issue:`7268`)

* Cython's type sharing across modules suffered from race conditions if multiple modules
tried to initialise and share their types concurrently.  This is due to an underlying
CPython issue and cannot easily be worked around completely.  In the common case that
module dicts are plain Python dict objects, however, Cython now uses a ``.setdefault()``
equivalent for thread-safe type sharing.
See https://github.com/python/cpython/issues/137422
(Github issue :issue:`7076`)

* Cython incorrectly called ``PyList_GetItemRef()`` in PyPy and GraalPython before Py3.13.
(Github issue :issue:`7269`)

3.2.0b2

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

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

* The code generated for importing and exporting cimports across modules uses less space.
(Github issues :issue:`7255`, :issue:`7265`)

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

* Iteration over memoryviews could loop indefinitely in 3.2b1 when encountering a ``continue`` statement.
(Github issue :issue:`7259`)

* Extension arguments defined for the shared code module were ignored in ``cythonize()``.
(Github issue :issue:`7251`)

* Failures while following package attributes in ``import pkg.module as …`` were not handled.

* Trying to instantiate internal types used by Cython is now prohibited.
(Github issue :issue:`7263`)

* Includes all fixes as of Cython 3.1.6.

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

* The ``musllinux`` platform is now served with an abi3 Cython wheel instead of Python specific ones.
(Github issue :issue:`7250`)

3.2.0b1

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

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

* Builtin exception types are now inferred.
(Github issue :issue:`6908`)

* The list of known, inferred and optimised Python builtins was updated.
`range` is now considered a type. `ascii`, `bin`, `format`, `hex`, `oct` were added as functions.
(Github issue :issue:`6931`)

* The f-string syntax was extended according to PEP-701.
(Github issue :issue:`5452`)

* t-strings are implemented according to PEP-750.  The implementation backports the template classes
but prefers existing backports if installed separately.
(Github issue :issue:`6811`)

* Unknown return type annotations with `->` are no longer rejected but produce warnings.
This allows better integration with Python type hints that are not always usable for Cython.
``-> None``  is also allowed now.
Patch by jpe.  (Github issue :issue:`6946`)

* The runtime Python dispatch for fused functions is substantially faster.
(Github issues :issue:`1385`, :issue:`6996`)

* Freelists (via cdef class decorator and for internally used types such as ``async``)
are now also used in the Limited API and with extension type specs enabled.
(Github issue :issue:`7151`)

* Module imports now quickly check for an already imported module to speed up reimports.
Patch by Lysandros Nikolaou.  (Github issue :issue:`7035`)

* Type checks on PEP-604 union types (`int | None`) are optimised into separate checks.
(Github issue :issue:`6935`)

* Assignments to the PEP-604 union type `float | None` allow any suitable Python number as input
and convert it to a Python `float` automatically.
(Github issue :issue:`5750`)

* Item type inference was improved for looping over literals.
(Github issue :issue:`6912`)

* Looping over literal sequences and strings now uses efficient C array looping if possible.
(Github issue :issue:`6926`)

* Releasing the GIL from an unknown lock state is more efficient.
(Github issue :issue:`6847`)

* ``cython.critical_section(PyMutex)`` now works, as with Python objects.
(Github issue :issue:`6847`)

* ``bool(c_int/float/ptr)`` avoid passing through Python objects.
(Github issue :issue:`7015`)

* Variables assigned inside of ``prange`` loops can now be initialised outside of the loop.
(Github issue :issue:`7178`)

* Unused exceptions in ``except`` clauses are detected in some more cases to avoid their normalisation.
(Github issue :issue:`7021`)

* Mixed operations on C integers with Python ints use less code and are more streamlined for Py3.12+.
(Github issue :issue:`7244`)

* Some object constants are now marked as ``immortal`` to speed up their reference counting
in recent CPython versions.  This can be configured with the ``CYTHON_IMMORTAL_CONSTANTS`` C macro.
(Github issue :issue:`7118`)

* Further improvements were made to reduce the size of the resulting extension modules.
(Github issue :issue:`6983`, :issue:`7199`, :issue:`7220`, :issue:`7238`)

* Several improvements were made in freethreaded Python code.
(Github issues :issue:`6936`, :issue:`6939`, :issue:`6949`, :issue:`6984`,
:issue:`7011`, :issue:`7066`, :issue:`7114`, :issue:`7200`)

* Several improvements were made for the Limited API.
(Github issues :issue:`6959`, :issue:`6991`)

* Several improvements were made for the GraalPython support.
Patch by Michael Šimáček.  (Github issue :issue:`7074`)

* Some GIL-safe C-API wrappers were added to the libc/libcpp declarations.
(Github issue :issue:`6829`, :issue:`6993`)

* String and number constants use less storage space in the module.
(Github issues :issue:`6971`, :issue:`6978`, :issue:`6986`)

* The managed dict/weakref support in CPython 3.12+ is used for internal types
to benefit from future CPython optimisations here.
(Github issue :issue:`6891`)

* Using ``NaN`` as exception return value is supported.
(Github issues :issue:`6900`, :issue:`6903`)

* Declarations for C++ condition variables were added.
(Github issue :issue:`6836`)

* The annotated source HTML page shows alternating +/− markers to open/close lines.
Patch by Kamil Monicz.  (Github issue :issue:`7099`)

* ``cython --embed`` gained a new option ``--embed-modules=…`` to list further extension modules
that will be statically linked into the generated extension module, to get them initialised
on application start.
(Github issue :issue:`2849`)

* The ``setup.py`` script of Cython now allows passing the desired Limited API version
like ``--cython-limited-api=3.11``.
(Github issue :issue:`7228`)

* Unicode 16.0.0 is used to parse identifiers.
(Github issue :issue:`6836`)

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

* Special float exception values could generate invalid C code.
(Github issues :issue:`6900`, :issue:`6903`)

* References to the Python ``bool`` type could generate invalid C code.
(Github issue :issue:`6902`)

* Unicode characters formatted from C integers with ``f"{value:c}"`` could result in
invalid Python string objects since Cython 3.1.0.
(Github issue :issue:`7240`)

* Vectorcalls could use needless temp assignments for ``self``.
(Github issue :issue:`6909`)

* Iterating over temporary memoryviews could crash Cython.
(Github issue :issue:`7005`)

* Type casts on constants as part of numeric expressions could crash Cython.
(Github issue :issue:`6779`)

* Long code bodies in ``with`` statements could crash Cython.
(Github issue :issue:`7122`)

* Indexing ``bytes`` failed to optimise in some cases.
(Github issue :issue:`6997`)

* Optimised C integer formatting in f-strings failed to apply to typedef types.
(Github issue :issue:`7170`)

* In auto-pickling, trying to unpickle an object that has no ``__dict__`` from object pickle data
that includes instance dict state is now an error.
(Github issue :issue:`7222`)

* The type objects of heap types were not always correctly decrefed on deallocation.
(Github issue :issue:`7145`)

* Pure mode type aliases like ``p_int`` or ``ulong`` leaked into some C type contexts,
risking to conflict with user declarations.
(Github issues :issue:`6922`, :issue:`6339`)

* Boolean (emptyness) tests on builtin containers could fail to handle (unlikely) errors.
(Github issue :issue:`7090`)

* The return type of ``bytes.join()`` was sometimes inferred as plain ``object``.
(Github issue :issue:`6987`)

* Type inference could fail to understand ``prange()`` arguments.
(Github issue :issue:`6974`)

* ``embedsignatures`` failed if ``lambda`` was used in function default arguments.
(Github issue :issue:`6880`)

* An internal C function was not marked as ``static`` and leaked a linker symbol.
(Github issue :issue:`6957`)

* ``PyType_FromModuleAndSpec`` was incorrectly used in Limited API code before Py3.10.
(Github issue :issue:`7181`)

* Conversion code for memoryview dtypes from and to Python objects generated C warnings about
incorrect ``const`` / non-``const``  casting code.
(Github issue :issue:`7219`)

* ``cythonize`` (program and function) now uses ``concurrent.futures.ProcessPoolExecutor``
instead of ``multiprocessing.Pool`` to fix a hang on build failures in parallel builds.
A possible work-around is to disable parallel builds.
Patch by Sviatoslav Sydorenko.  (Github issue :issue:`7183`)

* Cython's tools and frontend scripts now use ``python3``  instead of just ``python``
in their shebang line.
Patch by Matti Picus.  (Github issue :issue:`7053`)

* The ``setup.py`` script in the ``Demos/`` subdirectory failed to build.
(Github issue :issue:`7228`)

* Includes all fixes as of Cython 3.1.5.

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

* Some lesser used platforms (Windows ARM/i686, macOS x86_64, Linux i686) now use Py3.9 abi3 binary wheels
instead of Python version specific wheels.  We also added a abi3 wheel for armv7l.
(Github issues :issue:`7227`, :issue:`7248`)

* Usages of `Py_TPFLAGS_HAVE_FINALIZE` were removed.  The constant remains available as cimport from
``cpython.object`` for legacy reasons.
(Github issue :issue:`6423`)

3.1.7

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

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

* Cython incorrectly called ``PyList_GetItemRef()`` in PyPy and GraalPython before Py3.13.
(Github issue :issue:`7269`)

* Trying to instantiate internal types used by Cython is now prohibited.
(Github issue :issue:`7263`)

3.1.6

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

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

* Unicode characters formatted from C integers with ``f"{value:c}"`` could result in
invalid Python string objects since Cython 3.1.0.
(Github issue :issue:`7240`)

* ``cythonize`` (program and function) now uses ``concurrent.futures.ProcessPoolExecutor``
instead of ``multiprocessing.Pool`` to fix a hang on build failures in parallel builds.
A possible work-around is to disable parallel builds.
Patch by Sviatoslav Sydorenko.  (Github issue :issue:`7183`)

3.1.5

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

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

* Conversion from C++ strings longer than ``PY_SSIZE_T_MAX`` did not validate the length.

* Some non-Limited API code was incorrectly used in generated header files.
(Github issue :issue:`7157`)

* Optimised unpacking of Python integers in expressions uses a slightly safer scheme.
(Github issue :issue:`7134`)

* Empty return statements were not always reported when tracing.
(Github issue :issue:`7022`)

* Value conversion errors when tracing C return statements no longer fail the trace
but fall back to reporting ``None`` returns instead.
(Github issue :issue:`6503`)

3.1.4

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

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

* Declarations for the new ``PyUnstable_*()`` refcounting C-API functions in Py3.14 were added.
(Github issue :issue:`6836`)

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

* The monitoring code could crash on tracing.
(Github issue :issue:`7050`)

* Initialising the monitoring code could fail with a CPython exception.
See https://github.com/nedbat/coveragepy/issues/1790#issuecomment-3257410149

* Optimised integer shifting triggered undefined behaviour in C.
(Github issue :issue:`7089`)

* Deallocating objects that inherit from external types defined in pxd files
could run into an infinite loop.
(Github issue :issue:`7143`)

* A reference to metaclasses could be leaked on instantiation.
(Github issue :issue:`7130`)

* (Unlikely) error handling during empty builtin container tests was ineffective.
(Github issue :issue:`7190`)

* Generated ``*_api.h`` files used potentially unknown Cython configuration macros.
(Github issue :issue:`7108`)

* ``cythonize()`` avoids parallel compiler runs on systems using ``spawn()`` in multiprocessing.
Patch by Marcel Bargull.  (Github issue :issue:`3262`)

* The ``cython.ufunc``  decorator was missing in type checker stubs.
Patch by jayClean.  (Github issue :issue:`7109`)

3.1.3

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

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

* Some method calls with 0 or 1 argument failed to use ``PyObject_VectorCallMethod()``.

* Walrus assignments of literal Python integers could generate invalid C code.
(Github issue :issue:`6989`)

* ``cython.pythread_type_lock`` (also used as fallback for ``cython.pymutex``)
could stall on heavily contended locks.
(Github issue :issue:`6999`)

* C string arrays (not pointers) always coerced to the Python default string type,
even on explicit casts to other string types.
(Github issue :issue:`7020`)

* Unterminated ``\N{}`` character escapes in strings could unrail the parser.
(Github issue :issue:`7056`)

* An internal C function was not marked as ``static`` and leaked a linker symbol.
(Github issue :issue:`6957`)

* Some Unicode letters were not recognised as lexically valid name parts.
(Github issue :issue:`7059`)

* Compatibility with PyPy3.8 was lost by accident.

* The Linux binary wheels of 3.1.2 used SSSE3 CPU instructions which are not available on some CPUs.
(Github issue :issue:`7038`)

3.1.2

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

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

* Attribute lookups failed on the ``bool`` builtin type.
(Github issue :issue:`6905`)

* Type checks on or-ed union types could incorrectly return false.
(Github issue :issue:`6420`)

* Negative list indexing could accidentally wrap around twice in PyPy and the Limited API.

* Iterating over literal sequences with starred (unpacked) items could infer a wrong
type for the loop variable and fail to assign the values.
(Github issue :issue:`6924`)

* Calls to C functions taking exception types failed to check for a `None` argument.
(Github issue :issue:`6420`)

* Fused functions had an incorrect ``__module__`` attribute.
(Github issue :issue:`6897`)

* The type of Cython implemented functions had an incorrect ``__module__`` attribute.
(Github issue :issue:`6841`)

* Errors while indexing into ``bytearray`` or ``str`` in ``nogil`` sections could crash.
(Github issue :issue:`6947`)

* ``bytearray.append()`` could silently accept some invalid character numbers.

* The C++11 ``<type_traits>`` header was included regardless of the C++ version.
(Github issue :issue:`6896`)

* ``PyDict_GetItemStringRef()`` was accidentally used in older Limited API versions.
(Github issue :issue:`6914`)

* ``abort()`` was used but not always available in the Limited API.
(Github issue :issue:`6918`)

* Some dependencies were missing from the ``depfile``.
(Github issue :issue:`6938`)

* Embedded function signatures were not always separated from the existing docstring.
(Github issue :issue:`6904`)

* ``numpy.math`` was missing from ``Cython/Includes/`` and could not be cimported.
(Github issue :issue:`6859`)

* Some tests were adapted for NumPy 2.x.
(Github issue :issue:`6898`)

* Some C compiler warnings were fixed.
(Github issue :issue:`6870`)

* ``Cython.Build`` was not officially exposing the ``cythonize`` function.
(Github issue :issue:`6934`)

3.1.1

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

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

* A reference leak in the async delegation code was fixed.
(Github issues :issue:`6850`, :issue:`6878`)

* Conditional if-else expressions mixing Python and C (numeric) types could end up
inferring an overly tight result type, thus leading to unexpected type conversions,
runtime exceptions on assignment, or incorrect "temporary assignment" compile errors.
(Github issue :issue:`6854`)

* Some Limited API issues were resolved.
(Github issue :issue:`6862`)

* Large C ``long long`` values could be truncated when passed into PyPy.
(Github issue :issue:`6890`)

* ``callable()`` incorrectly reported ``False`` in PyPy for classes with metaclasses.
Patch by Anatolii Aniskovych. (Github issue :issue:`6892`)

* The signature of fused functions was no longer introspectable in Cython 3.1.0.
(Github issue :issue:`6855`)

* Coroutines could generate invalid C with line tracing enabled.
(Github issue :issue:`6865`)

* Code using ``complex()`` could generate invalid C code missing type declarations.
(Github issue :issue:`6860`)

* Code using e.g. ``list[int | None]``  outside of variable/argument annotations failed to compile.
(Github issue :issue:`6856`)

* Code using ctuples in a ``const`` context could generate invalid C.
(Github issue :issue:`6864`)

* Accessing special methods on cpdef enums failed to compile.

* Some C compiler warnings were resolved.
Patches by Daniel Larraz.  (Github issues :issue:`6876`, :issue:`3172`, :issue:`6873`, :issue:`6877`)

* Re-establish support for PyPy 3.8.
(Github issue :issue:`6867`)

3.1.0

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

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

* Support for freethreading builds of CPython 3.13 was added.
It comes with a new directive ``freethreading_compatible=True`` to mark modules as
free-threading compatible (``Py_mod_gil``).

https://github.com/cython/cython/issues?q=label%3A%22nogil+CPython%22

Patches by Lysandros Nikolaou and Nathan Goldbaum.  (Github issue :issue:`6162`)

* Support for monitoring Cython modules via `sys.monitoring` in CPython 3.13+ was added.
For coverage reporting, this needs to be disabled with `-DCYTHON_USE_SYS_MONITORING=0`
as long as `coverage.py` does not support `sys.monitoring` for coverage plugins.
(Github issue :issue:`6144`)

* Many issues with the Limited C-API were resolved.
It is now sufficient to define the macro ``Py_LIMITED_API`` to activate the support.

https://github.com/cython/cython/issues?q=label%3A%22limited+api%22

* Support for GraalPython was improved (but is still incomplete).

* Several issues with the gdb support were resolved.
Patches by Kent Slaney.  (Github issues :issue:`5955`, :issue:`5948`)

* ``typing.Union[SomeType, None]`` and ``SomeType | None`` are now understood and mean
the same as ``typing.Optional[SomeType]``, allowing ``None`` in type checks.
(Github issue :issue:`6254`)

* ``cython.const[]`` and ``cython.volatile[]`` are now available as type modifiers in Python code.
(Github issue :issue:`5728`)

* ``cython.pointer[SomeCType]`` can now be used to define pointer types in Python type annotations.
(Github issue :issue:`5071`)

* Several improvements were made to reduce the size of the resulting extension modules.
(Github issue :issue:`4425`)

* Function calls now use the PEP-590 Vectorcall protocol, even when passing keyword arguments.
(Github issues :issue:`5804`)

* Coroutines now use the ``am_send`` slot function instead of going through a Python ``.send()`` call.
This has been backported for Python 3.7 - 3.9.
(Github issues :issue:`4585`)

* ``__set_name__`` is called when assigning to class attributes.
(Github issue :issue:`6179`)

* Most builtin methods now provide their return type for type inference.
(Github issues :issue:`4829`, :issue:`5865`, :issue:`6412`)

* Method calls on builtin literal values are evaluated at compile time, if applicable.
(Github issue :issue:`6383`)

* The Python ``int`` type now maps directly to ``PyLong`` and is inferred accordingly.
(Github issue :issue:`4237`)

* Integer operations on known ``int`` types are faster.
(Github issue :issue:`5785`)

* f-strings are faster in some cases.
(Github issues :issue:`5866`, :issue:`6342`, :issue:`6383`)

* ``divmod()`` is faster on C ``int``.
Patch by Tong He.  (Github issue :issue:`6073`)

* ``dict.pop()`` is faster in some cases.
(Github issue :issue:`5911`)

* ``.isprintable()`` is optimised for Unicode characters.
(Github issue :issue:`3277`)

* ``x in ()`` and similar tests against empty constant sequences (e.g. in generated code)
are now discarded if they have no side-effects.
(Github issue :issue:`6288`)

* Constant (non-GC) Python objects are no longer traversed with ``Py_VISIT()`` during GC runs.
(Github issue :issue:`6277`)

* C++ classes implemented in Cython can now use method overloading.
Patch by samaingw.  (Github issue :issue:`3235`)

* Assigning a Python container to a C++ vector now makes use of ``__length_hint__``
to avoid reallocations.
Patch by Denis Lukianov.  (Github issue :issue:`6077`)

* The C++11 ``emplace*`` methods were added to ``libcpp.deque``.
Patch by Somin An.  (Github issue :issue:`6159`)

* ``cpython.time`` was updated and extended for Python 3.13.
(Github issue :issue:`6187`)

* Dataclasses support the ``match_args`` option.
(Github issue :issue:`5381`)

* Threading in parallel sections can now be disabled with a new ``use_threads_if`` condition.
(Github issue :issue:`5919`)

* New options ``warn.deprecated.DEF`` and ``warn.deprecated.IF`` can silence the deprecation warnings.
Patch by Eric Larson.  (Github issue :issue:`6243`)

* ``cygdb`` shows more helpful output for some objects.
Patch by Kent Slaney.  (Github issue :issue:`5958`)

* Bazel build support for improved.
Patch by mering.  (Github issue :issue:`6452`)

* The parser was updated for Unicode 15.1 (as provided by CPython 3.13b4).

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

* C functions used different start lines and columns for error reporting and tracing
than Python functions.  They now use the line and column of their first decorator
or (if none) their definition line, as in Python.
(Github issue :issue:`6366`)

* Dataclasses did not handle default fields without init value correctly.
(Github issue :issue:`5858`)

* Implementing a special method based on another could lead to infinite recursion.
(Github issue :issue:`5863`)

* The ``__class__`` cell variable in methods was not always working as in Python.
Initial patch by Tom Keefe.  (Github issue :issue:`2912`)

* Lambda functions had no code objects. Their signature can now be introspected.
(Github issue :issue:`2983`)

* Subtyping `complex` as extension type could fail.
(Github issue :issue:`6346`)

* ``hasattr()`` now propagates exceptions that occur during lookup.
(Github issue :issue:`6269`)

* The base type of extension heap types is now traversed during GC runs in Py3.9+.
(Github issue :issue:`4193`)

* The Python ``&`` operator could touch invalid memory with certain ``0`` values in Python <= 3.10.
Patch by Michael J. Sullivan.  (Github issue :issue:`4193`)

* Exception values were not always recognised as equal at compile time.
(Github issue :issue:`5709`)

* Running Cython in different Python versions could generate slightly different C code
due to differences in the builtins.
(Github issue :issue:`5591`)

* The `common_include_dir` feature used different file paths in the C code on Windows and Posix.
It now uses forward slashes as directory separator consistently.
(Github issue :issue:`6355`)

* File paths in the C code are now relative to the build directory.
Patch by Oscar Benjamin.  (Github issue :issue:`6341`)

* depfiles now use relative paths whenever possible.
Patch by Loïc Estève.  (Github issue :issue:`6345`)

* The ``-a`` option in the IPython magic no longer copies the complete HTML document
into the notebook but only a more reasonable content snippet.
Patch by Min RK.  (Github issue :issue:`5760`)

* Uselessly referring to C enums (not enum values) as Python objects is now rejected.
Patch by Vyas Ramasubramani.  (Github issue :issue:`5638`)

* Cython no longer acquires the GIL during in-place assignments to C attributes in nogil sections.
Patch by Mads Ynddal.  (Github issue :issue:`6407`)

* Several C++ warnings about ``char*`` casts were resolved.
(Github issues :issue:`5515`, :issue:`5847`)

* C++ undefined behaviour was fixed in an error handling case.
(Github issue :issue:`5278`)

* Dict assignments to struct members with reserved C/C++ names could generate invalid C code.

* The PEP-479 implementation could raise a visible ``RuntimeError`` without
a trace of the original ``StopIteration``.
(Github issue :issue:`5953`)

* A crash was fixed when assigning a zero-length slice to a memoryview.
Patch by Michael Man.  (Github issue :issue:`6227`)

* Conditionally assigning to variables with the walrus operator could crash.
(Github issue :issue:`6094`)

* Unterminated string literals could lock up the build in an infinite loop.
(Github issue :issue:`5977`)

* Exporting C functions uses better platform compatible code.
(Github issue :issue:`4683`)

* The shebang in ``libpython.py`` was incorrect.
Patch by Luke Hamburg.  (Github issue :issue:`6439`)

* Cython now uses `SHA-256` instead of `SHA-1` for caching etc. as the latter may not be
available on all Python installations.
(Github issue :issue:`6354`)

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

* Support for Python 2.7 - 3.7 was removed, along with large chunks of legacy code.
(Github issue :issue:`2800`)

* The pxd files ``cpython.int``, ``cpython.cobject``, ``cpython.oldbuffer`` and ``cpython.string``
were removed as they refer to C-API declarations that are only in Python 2.x.
(Github issue :issue:`5870`)

* The generated C code now requires a C99 compatible C compiler.

* ``language_level=3`` is now the default.
``language_level=3str`` has become a legacy alias.
(Github issue :issue:`5827`)

* The Py2 types ``unicode`` and ``basestring`` are now deprecated and have become aliases
of the ``str`` type.
(Github issue :issue:`6374`)

* Docstrings now strip their leading whitespace according to PEP-257.
Patch by Lawrence Mitchell.  (Github issue :issue:`6241`)

* Type checkers should have it easier to find and validate Cython types in .py files.
(Github issue :issue:`4327`)

* The previously shipped NumPy C-API declarations (``cimport numpy``) were removed.
NumPy has been providing version specific declarations for several versions now.
(Github issue :issue:`5842`)

* Usages of the outdated ``WITH_THREAD`` macro guard were removed.
(Github issue :issue:`5812`)

* The options for showing the C code line in Python exception stack traces were cleaned up.
Previously, disabling the option with the ``CYTHON_CLINE_IN_TRACEBACK`` macro did not
reduce the code overhead of the feature, and the ``c_line_in_traceback`` compile option
was partly redundant with the C macro switches and lead to warnings about unused code.
Since this is considered mostly a debug feature, the new default is that it is _disabled_
to avoid code and runtime overhead.  It can be enabled by setting the C macro to 1, and
a new macro ``CYTHON_CLINE_IN_TRACEBACK_RUNTIME`` was added that controls the runtime
configurable setting if the feature is enabled, which was previously only available
through the compile option.  The compile option is now deprecated (but still available),
and users should migrate to using the two C macros only.
(Github issue :issue:`6036`)

* Includes all fixes as of Cython 3.0.11 (but generates C99 code in some places).

3.0.12

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

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

* Release 3.0.11 introduced some incorrect ``noexcept`` warnings.
(Github issue :issue:`6335`)

* Conditional assignments to variables using the walrus operator could crash.
(Github issue :issue:`6094`)

* Dict assignments to struct members with reserved C names could generate invalid C code.

* Fused ctuples with the same entry types but different sizes could fail to compile.
(Github issue :issue:`6328`)

* In Py3, `pyximport` was not searching `sys.path` when looking for importable source files.
(Github issue :issue:`5615`)

* Using `& 0` on integers produced with `int.from_bytes()` could read invalid memory on Python 3.10.
(Github issue :issue:`6480`)

* Modules could fail to compile in PyPy 3.11 due to missing CPython specific header files.
Patch by Matti Picus.  (Github issue :issue:`6482`)

* Minor fix in C++ ``partial_sum()`` declaration.

3.0.11

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

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

* The C++11 ``emplace*`` methods were added to ``libcpp.deque``.
Patch by Somin An.  (Github issue :issue:`6159`)

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

* The exception check value of functions declared in pxd files was not always applied in 3.0.10.
(Github issue :issue:`6122`)

* A crash on exception deallocations was fixed.
(Github issue :issue:`6022`)

* A crash was fixed when assigning a zero-length slice to a memoryview.
Patch by Michael Man.  (Github issue :issue:`6227`)

* ``libcpp.optional.value()`` could crash if it raised a C++ exception.
Patch by Alexander Condello.  (Github issue :issue:`6190`)

* The return type of ``str()`` was mishandled, leading to crashes with ``language_level=3``.
(Github issue :issue:`6166`)

* ``bytes.startswith/endswith()`` failed for non-bytes substrings (e.g. ``bytearray``).
(Github issue :issue:`6168`)

* Fused ctuples crashed Cython.
(Github issue :issue:`6068`)

* A compiler crash was fixed when using extension types in fused types.
(Github issue :issue:`6204`)

* The module cleanup code was incorrect for globally defined memory view slices.
(Github issue :issue:`6276`)

* Some adaptations were made to enable compilation in Python 3.13.
(Github issues :issue:`5997`, :issue:`6182`, :issue:`6251`)

3.0.10

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

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

* Cython generated incorrect self-casts when directly calling final methods of subtypes.
Patch by Lisandro Dalcin.  (Github issue :issue:`2747`)

* Internal C names generated from C function signatures could become too long for MSVC.
(Github issue :issue:`6052`)

* The ``noexcept`` warnings could be misleading in some cases.
Patch by Gonzalo Tornaría.  (Github issue :issue:`6087`)

* The ``cython.ufunc`` implementation could generate incomplete C code.
(Github issue :issue:`6064`)

* The ``libcpp.complex`` declarations could result in incorrect C++ code.
Patch by Raffi Enficiaud.  (Github issue :issue:`6037`)

* Several tests were adapted to work with both NumPy 1.x and 2.0.
Patch by Matti Picus.  (Github issues :issue:`6076`, :issue:`6100`)

* C compiler warnings when the freelist implementation is disabled (e.g. on PyPy) were fixed.
It can now be disabled explicitly with the C macro guard ``CYTHON_USE_FREELISTS=0``.
(Github issue :issue:`6099`)

* Some C macro guards for feature flags were missing from the NOGIL Python configuration.

* Some recently added builtins were unconditionally looked up at module import time
(if used by user code) that weren't available on all Python versions and could thus
fail the import.

* A performance hint regarding exported pxd declarations was improved.
(Github issue :issue:`6001`)

3.0.9

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

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

* Assigning ``const`` values to non-const variables now issues a warning.
(Github issue :issue:`5639`)

* Using ``noexcept`` on a function returning Python objects now issues a warning.
(Github issue :issue:`5661`)

* Some C-API usage was updated for the upcoming CPython 3.13.
Patches by Victor Stinner et al.  (Github issues :issue:`6003`, :issue:`6020`)

* The deprecated ``Py_UNICODE`` type is no longer used, unless required by user code.
(Github issue :issue:`5982`)

* ``std::string.replace()`` declarations were added to libcpp.string.
Patch by Kieran Geary.  (Github issue :issue:`6037`)

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

* Cython generates incorrect (but harmless) self-casts when directly calling
final methods of subtypes.  Lacking a better solution, the errors that recent
gcc versions produce have been silenced for the time being.
Original patch by Michał Górny.  (Github issue :issue:`2747`)

* Unused variable warnings about clineno were fixed when C lines in tracebacks are disabled.
(Github issue :issue:`6035`)

* Subclass deallocation of extern classes could crash if the base class uses GC.
Original patch by Jason Fried.  (Github issue :issue:`5971`)

* Type checks for Python ``memoryview`` could use an invalid C function.
Patch by Xenia Lu.  (Github issue :issue:`5988`)

* Calling final fused functions could generate invalid C code.
(Github issue :issue:`5989`)

* Declaring extern enums multiple times could generate invalid C code.
(Github issue :issue:`5905`)

* ``pyximport`` used relative paths incorrectly.
Patch by Stefano Rivera.  (Github issue :issue:`5957`)

* Running Cython with globbing characters (``[]*?``) in the module search path could fail.
Patch by eewanco.  (Github issue :issue:`5942`)

* Literal strings that include braces could change the C code indentation.

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

* The "enum class not importable" warning is now only issued once per enum type.
(Github issue :issue:`5941`)

3.0.8

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

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

* Using ``const`` together with defined fused types could fail to compile.
(Github issue :issue:`5230`)

* A "use after free" bug was fixed in parallel sections.
(Github issue :issue:`5922`)

* Several types were not available as ``cython.*`` types in pure Python code.

* The generated code is now correct C89 again, removing some C++ style ``//`` comments
and C99-style declaration-after-code code ordering.  This is still relevant for some
ols C compilers, specifically ones that match old Python 2.7 installations.

3.0.7

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

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

* In the iterator of generator expressions, ``await`` and ``yield`` were not correctly analysed.
(Github issue :issue:`5851`)

* ``cpdef`` enums with the same name cimported from different modules could lead to
invalid C code.
(Github issue :issue:`5887`)

* Some declarations in ``cpython.unicode`` were fixed and extended.
(Github issue :issue:`5902`)

* Compiling fused types used in pxd files could crash Cython in Python 3.11+.
(Github issues :issue:`5894`,  :issue:`5588`)

* Source files with non-ASCII file names could crash Cython.
(Github issue :issue:`5873`)

* Includes all bug-fixes and features from the 0.29 maintenance branch
up to the :ref:`0.29.37` release.

3.0.6

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

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

* Fused def function dispatch is a bit faster.

* Declarations for the ``wchar`` PyUnicode API were added.
(Github issue :issue:`5836`)

* The Python "nogil" fork is now also detected with the new ``Py_GIL_DISABLED`` macro.
Patch by Hugo van Kemenade.  (Github issue :issue:`5852`)

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

* Comparing dataclasses could give different results than Python.
(Github issue :issue:`5857`)

* ``float(std::string)`` generated invalid C code.
(Github issue :issue:`5818`)

* Using ``cpdef`` functions with ``cimport_from_pyx`` failed.
(Github issue :issue:`5795`)

* A crash was fixed when string-formatting a Python value fails.
(Github issue :issue:`5787`)

* On item access, Cython could try the sequence protocol before the mapping protocol
in some cases if an object supports both.
(Github issue :issue:`5776`)

* A C compiler warning was resolved.
(Github issue :issue:`5794`)

* Complex numbers failed to compile in MSVC with C11.
Patch by Lysandros Nikolaou.  (Github issue :issue:`5809`)

* Some issues with the Limited API and with PyPy were resolved.
(Github issues :issue:`5695`, :issue:`5696`)

* A C++ issue in Python 3.13 was resolved.
(Github issue :issue:`5790`)

* Several directives are now also available (as no-ops) in Python code.
(Github issue :issue:`5803`)

* An error message was corrected.
Patch by Mads Ynddal.  (Github issue :issue:`5805`)

3.0.5

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

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

* Preliminary support for CPython 3.13a1 was added to allow early testing.
(Github issue :issue:`5767`)

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

* A compiler crash was fixed.
(Github issue :issue:`5771`)

* A typo in the ``always_allow_keywords`` directive for Python code was fixed.
Patch by lk-1984.  (Github issue :issue:`5772`)

* Some C compiler warnings were resolved.
Patch by Pierre Jolivet.  (Github issue :issue:`5780`)

3.0.4

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

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

* A new compiler directive ``show_performance_hints`` was added to disable the
newly added performance hint output.
(Github issue :issue:`5748`)

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

* cythonize` required ``distutils`` even for operations that did not build binaries.
(Github issue :issue:`5751`)

* A regression in 3.0.3 was fixed that prevented calling inline functions
from another inline function in ``.pxd`` files.
(Github issue :issue:`5748`)

* Some C compiler warnings were resolved.
Patch by Pierre Jolivet.  (Github issue :issue:`5756`)

3.0.3

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

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

* More warnings were added to help users migrate and avoid bugs.
(Github issue :issue:`5650`)

* A warning-like category for performance hints was added that bypasses ``-Werror``.
(Github issue :issue:`5673`)

* FastGIL now uses standard ``thread_local`` in C++.
(Github issue :issue:`5640`)

* ``reference_wrapper`` was added to ``libcpp.functional``.
Patch by Vyas Ramasubramani.  (Github issue :issue:`5671`)

* The ``cythonize`` command now supports the ``--cplus`` option known from the ``cython`` command.
(Github issue :issue:`5736`)

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

* Performance regressions where the GIL was needlessly acquired were fixed.
(Github issues :issue:`5670`, :issue:`5700`)

* A reference leak for exceptions in Python 3.12 was resolved.
Patch by Eric Johnson.  (Github issue :issue:`5724`)

* ``fastcall`` calls with keyword arguments generated incorrect C code.
(Github issue :issue:`5665`)

* Assigning the type converted result of a conditional (if-else) expression
to ``int`` or ``bool`` variables could lead to incorrect C code.
(Github issue :issue:`5731`)

* Early (unlikely) failures in Python function wrappers no longer set a
traceback in order to simplify the C code flow.  Being mostly memory
allocation errors, they probably would never have created a traceback anyway.
(Github issue :issue:`5681`)

* Relative cimports from packages with ``__init__.py`` files could fail.
(Github issue :issue:`5715`)

* Several issues with the Limited API support were resolved.
(Github issues :issue:`5641`, :issue:`5648`, :issue:`5689`)

* The code generated for special-casing both Cython functions and PyCFunctions was cleaned up
to avoid calling C-API functions that were not meant for the other type respectively.
This could previously trigger assertions in CPython debug builds and now also plays better
with the Limited API.
(Github issues :issue:`4804`, :issue:`5739`)

* Fix some C compiler warnings.
Patches by Ralf Gommers, Oleksandr Pavlyk, Sebastian Koslowski et al.
(Github issues :issue:`5651`, :issue:`5663`, :issue:`5668`, :issue:`5717`, :issue:`5726`, :issue:`5734`)

* Generating gdb debugging information failed when using generator expressions.
Patch by Oleksandr Pavlyk.  (Github issue :issue:`5552`)

* Passing a ``setuptools.Extension`` into ``cythonize()`` instead of a
``distutils.Extension`` could make it miss the matching extensions.

* ``cython -M`` needlessly required ``distutils``, which made it fail in Python 3.12.
(Github issue :issue:`5681`)

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

* The visible deprecation warning for ``DEF`` was removed again since it proved
difficult for some users to migrate away from it.  The statement is still
meant to be removed at some point (and thus, like ``IF``, should not be
used in new code), but the time for sunset is probably not around the corner.
(Github issue :issue:`4310`)

* The ``np_pythran`` option raise a ``DeprecationWarning`` if it receives other values
than ``True`` and ``False``.  This will eventually be disallowed (in line with all
other boolean options).

3.0.2

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

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

* Using ``None`` as default value for arguments annotated as ``int`` could crash Cython.
(Github issue :issue:`5643`)

* Default values of fused types that include ``complex`` could generate invalid C code
with ``-DCYTHON_CCOMPLEX=0``.
(Github issue :issue:`5644`)

* Using C++ enum class types in extension type method signatures could generate invalid C code.
(Github issue :issue:`5637`)

3.0.1

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

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

* The error messages regarding exception declarations were improved in order to give
better help about possible reasons and fixes.
(Github issue :issue:`5547`)

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

* Memory view types in Python argument annotations no longer accept ``None``.  They now
require an explicit ``Optional[]`` or a ``None`` default value in order to allow ``None``
to be passed.  This was an oversight in the 3.0.0 release and is a BACKWARDS INCOMPATIBLE
change.  However, since it only applies to code using Python syntax, it probably only
applies to newly written code that was written for Cython 3.0 and can easily be adapted.
In most cases, we expect that this change will avoid bugs in user code rather than
produce problems.
(Github issue :issue:`5612`)

* ``nogil`` functions using parallel code could freeze when called with the GIL held.
(Github issues :issue:`5564`, :issue:`5573`)

* Relative cimports could end up searching globally and find the same package installed
elsewhere, potentially in another version.
(Github issue :issue:`5511`)

* Attribute lookups on known standard library modules could accidentally search
in the module namespace instead.
(Github issue :issue:`5536`)

* Using constructed C++ default arguments could generate invalid C++ code.
(Github issue :issue:`5553`)

* ``libcpp.memory.make_unique()`` was lacking C++ exception handling.
(Github issue :issue:`5560`)

* Some non-public and deprecated CAPI usages were replaced by public
(and thus more future proof) API code.

* Many issues with the Limited API support were resolved.
Patches by Lisandro Dalcin et al.
(Github issues :issue:`5549`, :issue:`5550`, :issue:`5556`, :issue:`5605`, :issue:`5617`)

* Some C compiler warnings were resolved.
Patches by Matti Picus et al.  (Github issues :issue:`5557`, :issue:`5555`)

* Large Python integers are now stored in hex instead of decimal strings to work around
security limits in Python and generally speed up their Python object creation.

* ``NULL`` could not be used as default for fused type pointer arguments.
(Github issue :issue:`5554`)

* C functions that return pointer types now return ``NULL`` as default exception value.
Previously, calling code wasn't aware of this and always tested for raised exceptions.
(Github issue :issue:`5554`)

* Untyped literal default arguments in fused functions could generate invalid C code.
(Github issue :issue:`5614`)

* C variables declared as ``const`` could generate invalid C code when used in closures,
generator expressions, ctuples, etc.
(Github issues :issue:`5558`,  :issue:`5333`)

* Enums could not refer to previously defined enums in their definition.
(Github issue :issue:`5602`)

* The Python conversion code for anonymous C enums conflicted with regular int conversion.
(Github issue :issue:`5623`)

* Using memory views for property methods (and other special methods) could lead to
refcounting problems.
(Github issue :issue:`5571`)

* Star-imports could generate code that tried to assign to constant C macros like
``PY_SSIZE_T_MAX`` and ``PY_SSIZE_T_MIN``.
Patch by Philipp Wagner.  (Github issue :issue:`5562`)

* ``CYTHON_USE_TYPE_SPECS`` can now be (explicitly) enabled in PyPy.

* The template parameter "delimeters" in the Tempita ``Template`` class was corrected
to "delimiters".  The old spelling is still available in the main template API but
now issues a ``DeprecationWarning``.
(Github issue :issue:`5608`)

* The ``cython --version`` output is now  less likely to reach both stdout and stderr.
Patch by Eli Schwartz.  (Github issue :issue:`5504`)

* The sdist was missing the `Shadow.pyi` stub file.

3.0.0

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

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

* Cython functions now use the `PEP-590`_ vectorcall protocol in Py3.7+.
Patch by Jeroen Demeyer.  (Github issue :issue:`2263`)

* Unicode identifiers are supported in Cython code (`PEP-3131`_).
Patch by David Woods.  (Github issue :issue:`2601`)

* Unicode module names and imports are supported.
Patch by David Woods.  (Github issue :issue:`3119`)

* Annotations are no longer parsed, keeping them as strings following `PEP-563`_.
Patch by David Woods.  (Github issue :issue:`3285`)

* Preliminary support for the CPython's ``Py_LIMITED_API`` (stable ABI) is
available by setting the  ``CYTHON_LIMITED_API`` C macro.  Note that the
support is currently in an early stage and many features do not yet work.
You currently still have to define ``Py_LIMITED_API`` externally in order
to restrict the API usage.  This will change when the feature stabilises.
Patches by Eddie Elizondo and David Woods.  (Github issues :issue:`3223`,
:issue:`3311`, :issue:`3501`)

* The dispatch to fused functions is now linear in the number of arguments,
which makes it much faster, often 2x or more, and several times faster for
larger fused types with many specialisations.
Patch by will-ca.  (Github issue :issue:`1385`)

* ``with gil/nogil`` statements can be conditional based on compile-time
constants, e.g. fused type checks.
Patch by Noam Hershtig.  (Github issue :issue:`2579`)

* ``const`` can be used together with fused types.
Patch by Thomas Vincent.  (Github issue :issue:`1772`)

* Reimports of already imported modules are substantially faster.
(Github issue :issue:`2854`)

* Positional-only arguments are supported in Python functions (`PEP-570`_).
Patch by Josh Tobin.  (Github issue :issue:`2915`)

* The ``volatile`` C modifier is supported in Cython code.
Patch by Jeroen Demeyer.  (Github issue :issue:`1667`)

* ``cython.trashcan(True)`` can be used on an extension type to enable the
CPython :ref:`trashcan`. This allows deallocating deeply recursive objects
without overflowing the stack. Patch by Jeroen Demeyer.  (Github issue :issue:`2842`)

* Inlined properties can be defined for external extension types.
Patch by Matti Picus. (Github issue :issue:`2640`, redone later in :issue:`3571`)

* The ``str()`` builtin now calls ``PyObject_Str()`` instead of going
through a Python call.
Patch by William Ayd.  (Github issue :issue:`3279`)

* String concatenation can now happen in place if possible, by extending the
existing string rather than always creating a new one.
Patch by David Woods.  (Github issue :issue:`3453`)

* Multiplication of Python numbers with small constant integers is faster.
(Github issue :issue:`2808`)

* Some list copying is avoided internally when a new list needs to be created
but we already have a fresh one.
(Github issue :issue:`3494`)

* Extension types that do not need their own ``tp_new`` implementation (because
they have no object attributes etc.) directly inherit the implementation of
their parent type if possible.
(Github issue :issue:`1555`)

* The attributes ``gen.gi_frame`` and ``coro.cr_frame`` of Cython compiled
generators and coroutines now return an actual frame object for introspection.
(Github issue :issue:`2306`)

* Several declarations in ``cpython.*``, ``libc.*`` and ``libcpp.*`` were added.
Patches by Jeroen Demeyer, Matthew Edwards, Chris Gyurgyik, Jerome Kieffer
and Zackery Spytz.
(Github issues :issue:`3468`, :issue:`3332`, :issue:`3202`, :issue:`3188`,
:issue:`3179`, :issue:`2891`, :issue:`2826`, :issue:`2713`)

* Deprecated NumPy API usages were removed from ``numpy.pxd``.
Patch by Matti Picus.  (Github issue :issue:`3365`)

* ``cython.inline()`` now sets the ``NPY_NO_DEPRECATED_API=NPY_1_7_API_VERSION``
C macro automatically when ``numpy`` is imported in the code, to avoid C compiler
warnings about deprecated NumPy C-API usage.

* The builtin ``abs()`` function can now be used on C numbers in nogil code.
Patch by Elliott Sales de Andrade.  (Github issue :issue:`2748`)

* `PEP-479`_ (``generator_stop``) is now enabled by default with language level 3.
(Github issue :issue:`2580`)

* The ``cython.view.array`` type supports inheritance.
Patch by David Woods.  (Github issue :issue:`3413`)

* Code annotation accepts a new debugging argument ``--annotate-fullc`` that
will include the complete syntax highlighted C file in the HTML output.
(Github issue :issue:`2855`)

* ``--no-capture`` added to ``runtests.py`` to prevent stdout/stderr capturing
during srctree tests.
Patch by Matti Picus.  (Github issue :issue:`2701`)

* ``--no-docstrings`` option added to ``cythonize`` script.
Original patch by mo-han.  (Github issue :issue:`2889`)

* ``cygdb`` gives better error messages when it fails to initialise the
Python runtime support in gdb.
Patch by Volker Weissmann.  (Github issue :issue:`3489`)

* The Pythran ``shape`` attribute is supported.
Patch by Serge Guelton.  (Github issue :issue:`3307`)

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

* The unicode methods ``.upper()``, ``.lower()`` and ``.title()`` were
incorrectly optimised for single character input values and only returned
the first character if multiple characters should have been returned.
They now use the original Python methods again.

* Fused argument types were not correctly handled in type annotations and
``cython.locals()``.
Patch by David Woods.  (Github issues :issue:`3391`, :issue:`3142`)

* Diverging from the usual behaviour, ``len(memoryview)``, ``len(char*)``
and ``len(Py_UNICODE*)`` returned an unsigned ``size_t`` value.  They now
return a signed ``Py_ssize_t``, like other usages of ``len()``.

* Nested dict literals in function call kwargs could incorrectly raise an
error about duplicate keyword arguments, which are allowed when passing
them from dict literals.
(Github issue :issue:`2963`)

* Item access (subscripting) with integer indices/keys always tried the
Sequence protocol before the Mapping protocol, which diverged from Python
semantics.  It now passes through the Mapping protocol first when supported.
(Github issue :issue:`1807`)

* Name lookups in class bodies no longer go through an attribute lookup.
Patch by Jeroen Demeyer.  (Github issue :issue:`3100`)

* Broadcast assignments to a multi-dimensional memory view slice could end
up in the wrong places when the underlying memory view is known to be
contiguous but the slice is not.
(Github issue :issue:`2941`)

* Pickling unbound methods of Python classes failed.
Patch by Pierre Glaser.  (Github issue :issue:`2972`)

* The ``Py_hash_t`` type failed to accept arbitrary "index" values.
(Github issue :issue:`2752`)

* The first function line number of functions with decorators pointed to the
signature line and not the first decorator line, as in Python.
Patch by Felix Kohlgrüber.  (Github issue :issue:`2536`)

* Constant integer expressions that used a negative exponent were evaluated
as integer 0 instead of the expected float value.
Patch by Kryštof Pilnáček.  (Github issue :issue:`2133`)

* The ``cython.declare()`` and ``cython.cast()`` functions could fail in pure mode.
Patch by Dmitry Shesterkin.  (Github issue :issue:`3244`)

* ``__doc__`` was not available inside of the class body during class creation.
(Github issue :issue:`1635`)

* Setting ``language_level=2`` in a file did not work if ``language_level=3``
was enabled globally before.
Patch by Jeroen Demeyer.  (Github issue :issue:`2791`)

* ``__init__.pyx`` files were not always considered as package indicators.
(Github issue :issue:`2665`)

* Compiling package ``__init__`` files could fail under Windows due to an
undefined export symbol.  (Github issue :issue:`2968`)

* A C compiler cast warning was resolved.
Patch by Michael Buesch.  (Github issue :issue:`2775`)

* Binding staticmethods of Cython functions were not behaving like Python methods.
Patch by Jeroen Demeyer.  (Github issue :issue:`3106`, :issue:`3102`)

* Memoryviews failed to compile when the ``cache_builtins`` feature was disabled.
Patch by David Woods.  (Github issue :issue:`3406`)

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

* The default language level was changed to ``3str``, i.e. Python 3 semantics,
but with ``str`` literals (also in Python 2.7).  This is a backwards incompatible
change from the previous default of Python 2 semantics.  The previous behaviour
is available through the directive ``language_level=2``.
(Github issue :issue:`2565`)

* Cython no longer generates ``__qualname__`` attributes for classes in Python
2.x since they are problematic there and not correctly maintained for subclasses.
Patch by Jeroen Demeyer.  (Github issue :issue:`2772`)

* Source file fingerprinting now uses SHA-1 instead of MD5 since the latter
tends to be slower and less widely supported these days.
(Github issue :issue:`2790`)

* The long deprecated include files ``python_*``, ``stdio``, ``stdlib`` and
``stl`` in ``Cython/Includes/Deprecated/`` were removed.  Use the ``libc.*``
and ``cpython.*`` pxd modules instead.
Patch by Jeroen Demeyer.  (Github issue :issue:`2904`)

* The search order for include files was changed. Previously it was
``include_directories``, ``Cython/Includes``, ``sys.path``. Now it is
``include_directories``, ``sys.path``, ``Cython/Includes``. This was done to
allow third-party ``*.pxd`` files to override the ones in Cython.
Patch by Matti Picus.  (Github issue :issue:`2905`)

* The command line parser was rewritten and modernised using ``argparse``.
Patch by Egor Dranischnikow.  (Github issue :issue:`2952`, :issue:`3001`)

* Dotted filenames for qualified module names (``pkg.mod.pyx``) are deprecated.
Use the normal Python package directory layout instead.
(Github issue :issue:`2686`)

* Binary Linux wheels now follow the manylinux2010 standard.
Patch by Alexey Stepanov.  (Github issue :issue:`3355`)

* Support for Python 2.6 was removed.

.. _`PEP-560`: https://www.python.org/dev/peps/pep-0560
.. _`PEP-570`: https://www.python.org/dev/peps/pep-0570
.. _`PEP-487`: https://www.python.org/dev/peps/pep-0487
.. _`PEP-590`: https://www.python.org/dev/peps/pep-0590
.. _`PEP-3131`: https://www.python.org/dev/peps/pep-3131
.. _`PEP-563`: https://www.python.org/dev/peps/pep-0563
.. _`PEP-479`: https://www.python.org/dev/peps/pep-0479

0.29.37

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

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

* Fix a potential crash while cleaning up subtypes of externally imported extension
types when terminating Python.  This was introduced in Cython 0.29.35.

* Fix a ``complex`` related compile error on Windows.
(Github issue :issue:`5512`)

* Compiling fused types used in pxd files could crash Cython in Python 3.11+.
(Github issues :issue:`5894`, :issue:`5588`)

* ``cythonize`` failed to consider the ``CYTHON_FORCE_REGEN`` env variable.
Patch by Harmen Stoppels.  (Github issue :issue:`5712`)

0.29.36

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

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

* Async generators lost their return value in PyPy.
(Github issue :issue:`5465`)

* The outdated C macro ``_PyGC_F