After gh-130704, the interpreter replaces some uses of `LOAD_FAST` with
`LOAD_FAST_BORROW` which avoid incref/decrefs by "borrowing" references
on the interpreter stack when the bytecode compiler can determine that
it's safe.
This change broke some checks in C API extensions that relied on
`Py_REFCNT()` of `1` to determine if it's safe to modify an object
in-place. Objects may have a reference count of one, but still be
referenced further up the interpreter stack due to borrowing of
references.
This provides a replacement function for those checks.
`PyUnstable_Object_IsUniqueReferencedTemporary` is more conservative:
it checks that the object has a reference count of one and that it exists as a
unique strong reference in the interpreter's stack of temporary
variables in the top most frame.
See also:
* https://github.com/numpy/numpy/issues/28681
Co-authored-by: Pieter Eendebak <pieter.eendebak@gmail.com>
Co-authored-by: T. Wouters <thomas@python.org>
Co-authored-by: mpage <mpage@cs.stanford.edu>
Co-authored-by: Mark Shannon <mark@hotpy.org>
Co-authored-by: Victor Stinner <vstinner@python.org>
This exposes `_Py_TryIncref` as `PyUnstable_TryIncref()` and the helper
function `_PyObject_SetMaybeWeakref` as `PyUnstable_EnableTryIncRef`.
These are helpers for dealing with unowned references in a safe way,
particularly in the free threading build.
Co-authored-by: Petr Viktorin <encukou@gmail.com>
* Switch PyUnicode_InternInPlace to _PyUnicode_InternMortal, clarify docs
* Document immortality in some functions that take `const char *`
This is PyUnicode_InternFromString;
PyDict_SetItemString, PyObject_SetAttrString;
PyObject_DelAttrString; PyUnicode_InternFromString;
and the PyModule_Add convenience functions.
Always point out a non-immortalizing alternative.
* Don't immortalize user-provided attr names in _ctypes
Add Py_GetConstant() and Py_GetConstantBorrowed() functions.
In the limited C API version 3.13, getting Py_None, Py_False,
Py_True, Py_Ellipsis and Py_NotImplemented singletons is now
implemented as function calls at the stable ABI level to hide
implementation details. Getting these constants still return borrowed
references.
Add _testlimitedcapi/object.c and test_capi/test_object.py to test
Py_GetConstant() and Py_GetConstantBorrowed() functions.
Make PyObject_VisitManagedDict() and PyObject_ClearManagedDict()
functions public in Python 3.13 C API.
* Rename _PyObject_VisitManagedDict() to PyObject_VisitManagedDict().
* Rename _PyObject_ClearManagedDict() to PyObject_ClearManagedDict().
* Document these functions.
* Express functions which take argument as a C string in terms of
functions which take Python object.
* Use "note" directive for PyMapping_HasKey() and
PyMapping_HasKeyString() notes.
PEP 683 (immortal objects) revealed some ways in which the Python documentation has been unnecessarily coupled to the implementation details of reference counts. In the end users should focus on reference ownership, including taking references and releasing them, rather than on how many reference counts an object has.
This change updates the documentation to reflect that perspective. It also updates the docs relative to immortal objects in a handful of places.
Use a note:: tag so that these dict and object API deficiencies show up clearly.
A caution:: tag was considered, but our current python docs rendering doesn't do much with that (no box or color change). warning:: seemed too extreme. note looks good.
* Uncomment builtin removal in pairindextypes
* Use new-style index directive ('builtin') - C API
* Use new-style index directive ('builtin') - Extending
* Use new-style index directive ('builtin') - Library
* Use new-style index directive ('builtin') - Reference
* Use new-style index directive ('builtin') - Tutorial
Fix PyAiter_Check to only check for the `__anext__` presense (not for
`__aiter__`). Rename `PyAiter_Check()` to `PyAIter_Check()`,
`PyObject_GetAiter()` -> `PyObject_GetAIter()`.
Co-authored-by: Pablo Galindo Salgado <Pablogsal@gmail.com>
For example, fix the following Sphinx 3 errors:
Doc/c-api/buffer.rst:102: WARNING: Error in declarator or parameters
Invalid C declaration: Expected identifier in nested name. [error at 5]
void \*obj
-----^
Doc/c-api/arg.rst:130: WARNING: Unparseable C cross-reference: 'PyObject*'
Invalid C declaration: Expected end of definition. [error at 8]
PyObject*
--------^
The modified documentation is compatible with Sphinx 2 and Sphinx 3.
Some of the *SetItem methods in the C API steal a reference to the
given value. This annotates the better behaved ones to assure the
reader that these are not the ones with the inconsistent behaviour.
* 📜🤖 Added by blurb_it.
* make docs consistent with signature
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
CC @encukou
I'm also adding Petr Viktorin as contributor for vectorcall in the "what's new" section.
https://bugs.python.org/issue36974
Automerge-Triggered-By: @encukou
Automerge-Triggered-By: @encukou
Additional note: the `method_check_args` function in `Objects/descrobject.c` is written in such a way that it applies to all kinds of descriptors. In particular, a future re-implementation of `wrapper_descriptor` could use that code.
CC @vstinner @encukou
https://bugs.python.org/issue37645
Automerge-Triggered-By: @encukou
The fact that keyword names are strings is now part of the vectorcall and `METH_FASTCALL` protocols. The biggest concrete change is that `_PyStack_UnpackDict` now checks that and raises `TypeError` if not.
CC @markshannon @vstinner
https://bugs.python.org/issue37540
Peter Bierma