gh-106023: Remove _PyObject_FastCallTstate() function (#106273)

Doc/c-api/call.rst

@@ -113,19 +113,6 @@ function as with any other callable.
 :c:func:`PyObject_Vectorcall` will usually be most efficient.
 
 
-.. note::
-
-   In CPython 3.8, the vectorcall API and related functions were available
-   provisionally under names with a leading underscore:
-   ``_PyObject_Vectorcall``, ``_Py_TPFLAGS_HAVE_VECTORCALL``,
-   ``_PyObject_VectorcallMethod``, ``_PyVectorcall_Function``,
-   ``_PyObject_CallOneArg``, ``_PyObject_CallMethodNoArgs``,
-   ``_PyObject_CallMethodOneArg``.
-   Additionally, ``PyObject_VectorcallDict`` was available as
-   ``_PyObject_FastCallDict``.
-   The old names are still defined as aliases of the new, non-underscored names.
-
-
 Recursion Control
 .................
 

Include/internal/pycore_call.h

@@ -117,8 +117,7 @@ _PyObject_CallMethodIdOneArg(PyObject *self, _Py_Identifier *name, PyObject *arg
 
 /* === Vectorcall protocol (PEP 590) ============================= */
 
-// Call callable using tp_call. Arguments are like PyObject_Vectorcall()
+// Call callable using tp_call. Arguments are like PyObject_Vectorcall(),
-// or PyObject_FastCallDict() (both forms are supported),
 // except that nargs is plainly the number of arguments without flags.
 //
 // Export for shared stdlib extensions like the math extension,
@@ -204,14 +203,6 @@ _PyObject_CallNoArgs(PyObject *func) {
 }
 
 
-static inline PyObject *
-_PyObject_FastCallTstate(PyThreadState *tstate, PyObject *func,
-                         PyObject *const *args, Py_ssize_t nargs)
-{
-    EVAL_CALL_STAT_INC_IF_FUNCTION(EVAL_CALL_API, func);
-    return _PyObject_VectorcallTstate(tstate, func, args, (size_t)nargs, NULL);
-}
-
 extern PyObject *const *
 _PyStack_UnpackDict(PyThreadState *tstate,
     PyObject *const *args, Py_ssize_t nargs,

Python/sysmodule.c

@@ -979,12 +979,6 @@ static PyObject *
 call_trampoline(PyThreadState *tstate, PyObject* callback,
                 PyFrameObject *frame, int what, PyObject *arg)
 {
-
-    PyObject *stack[3];
-    stack[0] = (PyObject *)frame;
-    stack[1] = whatstrings[what];
-    stack[2] = (arg != NULL) ? arg : Py_None;
-
     /* Discard any previous modifications the frame's fast locals */
     if (frame->f_fast_as_locals) {
         if (PyFrame_FastToLocalsWithError(frame) < 0) {
@@ -993,7 +987,11 @@ call_trampoline(PyThreadState *tstate, PyObject* callback,
     }
 
     /* call the Python-level function */
-    PyObject *result = _PyObject_FastCallTstate(tstate, callback, stack, 3);
+    if (arg == NULL) {
+        arg = Py_None;
+    }
+    PyObject *args[3] = {(PyObject *)frame, whatstrings[what], arg};
+    PyObject *result = _PyObject_VectorcallTstate(tstate, callback, args, 3, NULL);
 
     PyFrame_LocalsToFast(frame, 1);
     return result;