bpo-46541: Replace core use of _Py_IDENTIFIER() with statically initialized global objects. (gh-30928)

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
This commit is contained in:
Eric Snow 2022-02-08 13:39:07 -07:00 committed by GitHub
parent c018d3037b
commit 81c72044a1
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
108 changed files with 2282 additions and 1573 deletions

View file

@ -163,7 +163,6 @@ static PyObject *
weakref_repr(PyWeakReference *self)
{
PyObject *name, *repr;
_Py_IDENTIFIER(__name__);
PyObject* obj = PyWeakref_GET_OBJECT(self);
if (obj == Py_None) {
@ -171,7 +170,7 @@ weakref_repr(PyWeakReference *self)
}
Py_INCREF(obj);
if (_PyObject_LookupAttrId(obj, &PyId___name__, &name) < 0) {
if (_PyObject_LookupAttr(obj, &_Py_ID(__name__), &name) < 0) {
Py_DECREF(obj);
return NULL;
}
@ -462,10 +461,9 @@ proxy_checkref(PyWeakReference *proxy)
#define WRAP_METHOD(method, special) \
static PyObject * \
method(PyObject *proxy, PyObject *Py_UNUSED(ignored)) { \
_Py_IDENTIFIER(special); \
UNWRAP(proxy); \
Py_INCREF(proxy); \
PyObject* res = _PyObject_CallMethodIdNoArgs(proxy, &PyId_##special); \
PyObject* res = PyObject_CallMethodNoArgs(proxy, &_Py_ID(special)); \
Py_DECREF(proxy); \
return res; \
}