Instead of manually enumerating the global strings in generate_global_objects.py, we extrapolate the list from usage of _Py_ID() and _Py_STR() in the source files.
This is partly inspired by gh-31261.
https://bugs.python.org/issue46541
Ensure strong references are acquired whenever using `set_next()`. Added randomized test cases for `__eq__` methods that sometimes mutate sets when called.
We're no longer using _Py_IDENTIFIER() (or _Py_static_string()) in any core CPython code. It is still used in a number of non-builtin stdlib modules.
The replacement is: PyUnicodeObject (not pointer) fields under _PyRuntimeState, statically initialized as part of _PyRuntime. A new _Py_GET_GLOBAL_IDENTIFIER() macro facilitates lookup of the fields (along with _Py_GET_GLOBAL_STRING() for non-identifier strings).
https://bugs.python.org/issue46541#msg411799 explains the rationale for this change.
The core of the change is in:
* (new) Include/internal/pycore_global_strings.h - the declarations for the global strings, along with the macros
* Include/internal/pycore_runtime_init.h - added the static initializers for the global strings
* Include/internal/pycore_global_objects.h - where the struct in pycore_global_strings.h is hooked into _PyRuntimeState
* Tools/scripts/generate_global_objects.py - added generation of the global string declarations and static initializers
I've also added a --check flag to generate_global_objects.py (along with make check-global-objects) to check for unused global strings. That check is added to the PR CI config.
The remainder of this change updates the core code to use _Py_GET_GLOBAL_IDENTIFIER() instead of _Py_IDENTIFIER() and the related _Py*Id functions (likewise for _Py_GET_GLOBAL_STRING() instead of _Py_static_string()). This includes adding a few functions where there wasn't already an alternative to _Py*Id(), replacing the _Py_Identifier * parameter with PyObject *.
The following are not changed (yet):
* stop using _Py_IDENTIFIER() in the stdlib modules
* (maybe) get rid of _Py_IDENTIFIER(), etc. entirely -- this may not be doable as at least one package on PyPI using this (private) API
* (maybe) intern the strings during runtime init
https://bugs.python.org/issue46541
bytesobject.c, bytearrayobject.c and unicodeobject.c now define all
macros used by stringlib, to avoid using undefined macros.
Fix "gcc -Wundef" warnings.
Added new internal functions to compute mod without also computing the quotient.
The loops can be leaner then, which leads to modestly but reliably faster execution in contexts that know they don't need the quotient.
Code by Jeremiah Vivian (Pascual).
Remove the PyHeapType_GET_MEMBERS() macro. It was exposed in the
public C API by mistake, it must only be used by Python internally.
Use the PyTypeObject.tp_members member instead.
Rename PyHeapType_GET_MEMBERS() to _PyHeapType_GET_MEMBERS() and move
it to the internal C API.
Move _Py_GetAllocatedBlocks() and _PyObject_DebugMallocStats()
declarations to pycore_pymem.h. These functions are related to memory
allocators, not to the PyObject structure.
Convert the PyType_SUPPORTS_WEAKREFS() macro to a regular function.
It no longer access the PyTypeObject.tp_weaklistoffset member
directly.
Add _PyType_SUPPORTS_WEAKREFS() static inline functions, used
internally by Python for best performance.
* bpo-46504: faster code for trial quotient in x_divrem()
This brings x_divrem() back into synch with x_divrem1(), which was changed
in bpo-46406 to generate faster code to find machine-word division
quotients and remainders. Modern processors compute both with a single
machine instruction, but convincing C to exploit that requires writing
_less_ "clever" C code.
Add _PyUnicode_FiniTypes() function, called by
finalize_interp_types(). It clears these static types:
* EncodingMapType
* PyFieldNameIter_Type
* PyFormatterIter_Type
_PyStaticType_Dealloc() now does nothing if tp_subclasses
is not NULL.
Add 'static_exceptions' list to factorize code between
_PyExc_InitTypes() and _PyBuiltins_AddExceptions().
_PyExc_InitTypes() does nothing if it's not the main interpreter.
Sort exceptions in Lib/test/exception_hierarchy.txt.
* Add comment to recurse_down_subclasses() explaining why it's safe
to use a borrowed reference to tp_subclasses.
* remove_all_subclasses() no longer accept NULL cases
* type_set_bases() now relies on the fact that new_bases is not NULL.
* type_dealloc_common() avoids PyErr_Fetch/PyErr_Restore if tp_bases
is NULL.
* remove_all_subclasses() makes sure that no exception is raised.
* Don't test at runtime if tp_mro only contains types: rely on
_PyType_CAST() assertion for that.
* _PyStaticType_Dealloc() no longer clears tp_subclasses which is
already NULL.
* mro_hierarchy() avoids calling _PyType_GetSubclasses() if
tp_subclasses is NULL.
Coding style:
* Use Py_NewRef().
* Add braces and move variable declarations to the first variable
assignement.
* Rename a few variables and parameters to use better names.
* Move PyContext static types into object.c static_types list.
* Rename PyContextTokenMissing_Type to _PyContextTokenMissing_Type
and declare it in pycore_context.h.
* _PyHamtItems types are no long exported: replace PyAPI_DATA() with
extern.
The remove_subclass() function now deletes the dictionary when
removing the last subclass (if the dictionary becomes empty) to save
memory: set PyTypeObject.tp_subclasses to NULL. remove_subclass() is
called when a type is deallocated.
_PyType_GetSubclasses() no longer holds a reference to tp_subclasses:
its loop cannot modify tp_subclasses.
Fix a race condition on setting a type __bases__ attribute: the
internal function add_subclass() now gets the
PyTypeObject.tp_subclasses member after calling PyWeakref_NewRef()
which can trigger a garbage collection which can indirectly modify
PyTypeObject.tp_subclasses.
Add a new _PyType_GetSubclasses() function to get type's subclasses.
_PyType_GetSubclasses(type) returns a list which holds strong
refererences to subclasses. It is safer than iterating on
type->tp_subclasses which yields weak references and can be modified
in the loop.
_PyType_GetSubclasses(type) now holds a reference to the tp_subclasses
dict while creating the list of subclasses.
set_collection_flag_recursive() of _abc.c now uses
_PyType_GetSubclasses().
Add types removed by mistake by the commit adding
_PyTypes_FiniTypes().
Move also PyBool_Type at the end, since it depends on PyLong_Type.
PyBytes_Type and PyUnicode_Type no longer depend explicitly on
PyBaseObject_Type: it's the default of PyType_Ready().
Christian Heimes
Robert-André Mauchin
Alex-Blade
Eric Snow
Raymond Hettinger
Dennis Sweeney
Petr Viktorin
Kumar Aditya
Mark Shannon
Victor Stinner
Zackery Spytz
Ken Jin
Crowthebird
Jelle Zijlstra
Tim Peters
Irit Katriel
Dong-hee Na
Gregory P. Smith