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
* Move _PyObject_VectorcallTstate() and _PyObject_FastCallTstate() to
pycore_call.h (internal C API).
* Convert PyObject_CallOneArg(), PyObject_Vectorcall(),
_PyObject_FastCall() and PyVectorcall_Function() static inline
functions to regular functions.
* Add _PyVectorcall_FunctionInline() static inline function.
* PyObject_Vectorcall(), _PyObject_FastCall(), and
PyObject_CallOneArg() now call _PyThreadState_GET() rather
than PyThreadState_Get().
The constants `RESTRICTED` and `PY_WRITE_RESTRICTED` no longer have a meaning in Python 3. Therefore, CPython should not use them.
CC @matrixise
https://bugs.python.org/issue36347
The bulk of this patch was generated automatically with:
for name in \
PyObject_Vectorcall \
Py_TPFLAGS_HAVE_VECTORCALL \
PyObject_VectorcallMethod \
PyVectorcall_Function \
PyObject_CallOneArg \
PyObject_CallMethodNoArgs \
PyObject_CallMethodOneArg \
;
do
echo $name
git grep -lwz _$name | xargs -0 sed -i "s/\b_$name\b/$name/g"
done
old=_PyObject_FastCallDict
new=PyObject_VectorcallDict
git grep -lwz $old | xargs -0 sed -i "s/\b$old\b/$new/g"
and then cleaned up:
- Revert changes to in docs & news
- Revert changes to backcompat defines in headers
- Nudge misaligned comments
Remove PyMethod_ClearFreeList() and PyCFunction_ClearFreeList()
functions: the free lists of bound method objects have been removed.
Remove also _PyMethod_Fini() and _PyCFunction_Fini() functions.
* Add _PyObject_VectorcallTstate() function: similar to
_PyObject_Vectorcall(), but with tstate parameter
* Add tstate parameter to _PyObject_MakeTpCall()
Methods are always bound, and `__self__` can no longer be `NULL`
(`method_new()` and `PyMethod_New()` both explicitly check for this).
Moreover, once a bound method is bound, it *stays* bound and won't be re-bound
to something else, so the section in the datamodel that talks about accessing
an methods in a different descriptor-binding context doesn't apply any more in
Python 3.
* Convert PyObject_INIT() and PyObject_INIT_VAR() macros to static
inline functions.
* Fix usage of these functions: cast to PyObject* or PyVarObject*.
* The hash of BuiltinMethodType instances no longer depends on the hash
of __self__. It depends now on the hash of id(__self__).
* The hash and equality of ModuleType and MethodWrapperType instances no
longer depend on the hash and equality of __self__. They depend now on
the hash and equality of id(__self__).
* MethodWrapperType instances no longer support ordering.
METH_NOARGS functions need only a single argument but they are cast
into a PyCFunction, which takes two arguments. This triggers an
invalid function cast warning in gcc8 due to the argument mismatch.
Fix this by adding a dummy unused argument.
* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals
Other globals are excluded (see globals.txt and check-c-globals.py).
Issue #27841: Add _PyObject_Call_Prepend() helper function to prepend an
argument to existing arguments to call a function. This helper uses fast calls.
Modify method_call() and slot_tp_new() to use _PyObject_Call_Prepend().
Victor Stinner
Michael J. Sullivan
Oleg Iarygin
Eric Snow
Dong-hee Na
Jeroen Demeyer
Dong-hee Na
Petr Viktorin
Victor Stinner
Inada Naoki
Jeroen Demeyer
Hai Shi
Martijn Pieters
Serhiy Storchaka
Siddhesh Poyarekar
Victor Stinner
Benjamin Peterson
Christian Heimes
Antoine Pitrou
Andrew Svetlov
David Malcolm