gh-106320: Remove _PyInterpreterState_Get() alias (#106321)

Replace calls to the (removed) slow _PyInterpreterState_Get() with
fast inlined _PyInterpreterState_GET() function.

Author: vstinner

Doc/whatsnew/3.13.rst

@@ -605,3 +605,10 @@ Removed
 
 * Remove ``cpython/pytime.h`` header file: it only contained private functions.
   (Contributed by Victor Stinner in :gh:`106316`.)
+
+* Remove ``_PyInterpreterState_Get()`` alias to
+  :c:func:`PyInterpreterState_Get()` which was kept for backward compatibility
+  with Python 3.8. The `pythoncapi-compat project
+  <https://github.com/python/pythoncapi-compat/>`__ can be used to get
+  :c:func:`PyInterpreterState_Get()` on Python 3.8 and older.
+  (Contributed by Victor Stinner in :gh:`106320`.)

Include/cpython/pystate.h

@@ -261,9 +261,6 @@ struct _ts {
 
 /* other API */
 
-// Alias for backward compatibility with Python 3.8
-#define _PyInterpreterState_Get PyInterpreterState_Get
-
 /* An alias for the internal _PyThreadState_New(),
    kept for stable ABI compatibility. */
 PyAPI_FUNC(PyThreadState *) _PyThreadState_Prealloc(PyInterpreterState *);
@@ -295,7 +292,7 @@ PyAPI_FUNC(int) PyGILState_Check(void);
    This function doesn't check for error. Return NULL before _PyGILState_Init()
    is called and after _PyGILState_Fini() is called.
 
-   See also _PyInterpreterState_Get() and _PyInterpreterState_GET(). */
+   See also PyInterpreterState_Get() and _PyInterpreterState_GET(). */
 PyAPI_FUNC(PyInterpreterState *) _PyGILState_GetInterpreterStateUnsafe(void);
 
 /* The implementation of sys._current_frames()  Returns a dict mapping

Include/internal/pycore_pystate.h

@@ -108,7 +108,7 @@ _Py_EnsureFuncTstateNotNULL(const char *func, PyThreadState *tstate)
 
    The caller must hold the GIL.
 
-   See also _PyInterpreterState_Get()
+   See also PyInterpreterState_Get()
    and _PyGILState_GetInterpreterStateUnsafe(). */
 static inline PyInterpreterState* _PyInterpreterState_GET(void) {
     PyThreadState *tstate = _PyThreadState_GET();

Misc/NEWS.d/next/C API/2023-07-02-00-00-20.gh-issue-106320.tZWcvG.rst

@@ -0,0 +1,3 @@
+Remove ``_PyInterpreterState_Get()`` alias to
+:c:func:`PyInterpreterState_Get()` which was kept for backward compatibility
+with Python 3.8. Patch by Victor Stinner.

Modules/_threadmodule.c

@@ -1104,7 +1104,7 @@ thread_run(void *boot_raw)
 static PyObject *
 thread_daemon_threads_allowed(PyObject *module, PyObject *Py_UNUSED(ignored))
 {
-    PyInterpreterState *interp = _PyInterpreterState_Get();
+    PyInterpreterState *interp = _PyInterpreterState_GET();
     if (interp->feature_flags & Py_RTFLAGS_DAEMON_THREADS) {
         Py_RETURN_TRUE;
     }

Objects/typeobject.c

@@ -6362,7 +6362,7 @@ object___reduce_ex___impl(PyObject *self, int protocol)
 /*[clinic end generated code: output=2e157766f6b50094 input=f326b43fb8a4c5ff]*/
 {
 #define objreduce \
-    (_Py_INTERP_CACHED_OBJECT(_PyInterpreterState_Get(), objreduce))
+    (_Py_INTERP_CACHED_OBJECT(_PyInterpreterState_GET(), objreduce))
     PyObject *reduce, *res;
 
     if (objreduce == NULL) {
@@ -9688,7 +9688,7 @@ resolve_slotdups(PyTypeObject *type, PyObject *name)
     /* XXX Maybe this could be optimized more -- but is it worth it? */
 
     /* pname and ptrs act as a little cache */
-    PyInterpreterState *interp = _PyInterpreterState_Get();
+    PyInterpreterState *interp = _PyInterpreterState_GET();
 #define pname _Py_INTERP_CACHED_OBJECT(interp, type_slots_pname)
 #define ptrs _Py_INTERP_CACHED_OBJECT(interp, type_slots_ptrs)
     pytype_slotdef *p, **pp;

Objects/unicodeobject.c

@@ -5831,7 +5831,7 @@ _PyUnicode_DecodeUnicodeEscapeInternal(const char *s,
     PyObject *errorHandler = NULL;
     PyObject *exc = NULL;
     _PyUnicode_Name_CAPI *ucnhash_capi;
-    PyInterpreterState *interp = _PyInterpreterState_Get();
+    PyInterpreterState *interp = _PyInterpreterState_GET();
 
     // so we can remember if we've seen an invalid escape char or not
     *first_invalid_escape = NULL;

Python/ceval_gil.c

@@ -491,15 +491,15 @@ take_gil(PyThreadState *tstate)
 
 void _PyEval_SetSwitchInterval(unsigned long microseconds)
 {
-    PyInterpreterState *interp = _PyInterpreterState_Get();
+    PyInterpreterState *interp = _PyInterpreterState_GET();
     struct _gil_runtime_state *gil = interp->ceval.gil;
     assert(gil != NULL);
     gil->interval = microseconds;
 }
 
 unsigned long _PyEval_GetSwitchInterval(void)
 {
-    PyInterpreterState *interp = _PyInterpreterState_Get();
+    PyInterpreterState *interp = _PyInterpreterState_GET();
     struct _gil_runtime_state *gil = interp->ceval.gil;
     assert(gil != NULL);
     return gil->interval;

Python/hamt.c

@@ -2425,7 +2425,7 @@ hamt_alloc(void)
 }
 
 #define _empty_hamt \
-    (&_Py_INTERP_SINGLETON(_PyInterpreterState_Get(), hamt_empty))
+    (&_Py_INTERP_SINGLETON(_PyInterpreterState_GET(), hamt_empty))
 
 PyHamtObject *
 _PyHamt_New(void)

Python/import.c

@@ -1123,7 +1123,7 @@ check_multi_interp_extensions(PyInterpreterState *interp)
 int
 _PyImport_CheckSubinterpIncompatibleExtensionAllowed(const char *name)
 {
-    PyInterpreterState *interp = _PyInterpreterState_Get();
+    PyInterpreterState *interp = _PyInterpreterState_GET();
     if (check_multi_interp_extensions(interp)) {
         assert(!_Py_IsMainInterpreter(interp));
         PyErr_Format(PyExc_ImportError,