gh-76785: Clean Up Interpreter ID Conversions (gh-117048)

Mostly we unify the two different implementations of the conversion code (from PyObject * to int64_t.  We also drop the PyArg_ParseTuple()-style converter function, as well as rename and move PyInterpreterID_LookUp().

Modules/_testcapimodule.c

@@ -1455,30 +1455,6 @@ get_interpreterid_type(PyObject *self, PyObject *Py_UNUSED(ignored))
     return Py_NewRef(&PyInterpreterID_Type);
 }
 
-static PyObject *
-link_interpreter_refcount(PyObject *self, PyObject *idobj)
-{
-    PyInterpreterState *interp = PyInterpreterID_LookUp(idobj);
-    if (interp == NULL) {
-        assert(PyErr_Occurred());
-        return NULL;
-    }
-    _PyInterpreterState_RequireIDRef(interp, 1);
-    Py_RETURN_NONE;
-}
-
-static PyObject *
-unlink_interpreter_refcount(PyObject *self, PyObject *idobj)
-{
-    PyInterpreterState *interp = PyInterpreterID_LookUp(idobj);
-    if (interp == NULL) {
-        assert(PyErr_Occurred());
-        return NULL;
-    }
-    _PyInterpreterState_RequireIDRef(interp, 0);
-    Py_RETURN_NONE;
-}
-
 static PyMethodDef ml;
 
 static PyObject *
@@ -3324,8 +3300,6 @@ static PyMethodDef TestMethods[] = {
     {"test_current_tstate_matches", test_current_tstate_matches, METH_NOARGS},
     {"run_in_subinterp",        run_in_subinterp,                METH_VARARGS},
     {"get_interpreterid_type",  get_interpreterid_type,          METH_NOARGS},
-    {"link_interpreter_refcount", link_interpreter_refcount,     METH_O},
-    {"unlink_interpreter_refcount", unlink_interpreter_refcount, METH_O},
     {"create_cfunction",        create_cfunction,                METH_NOARGS},
     {"call_in_temporary_c_thread", call_in_temporary_c_thread, METH_VARARGS,
      PyDoc_STR("set_error_class(error_class) -> None")},

Modules/_testinternalcapi.c

@@ -29,8 +29,6 @@
 #include "pycore_pyerrors.h"      // _PyErr_ChainExceptions1()
 #include "pycore_pystate.h"       // _PyThreadState_GET()
 
-#include "interpreteridobject.h"  // PyInterpreterID_LookUp()
-
 #include "clinic/_testinternalcapi.c.h"
 
 // Include test definitions from _testinternalcapi/
@@ -1112,7 +1110,7 @@ pending_identify(PyObject *self, PyObject *args)
     if (!PyArg_ParseTuple(args, "O:pending_identify", &interpid)) {
         return NULL;
     }
-    PyInterpreterState *interp = PyInterpreterID_LookUp(interpid);
+    PyInterpreterState *interp = _PyInterpreterState_LookUpIDObject(interpid);
     if (interp == NULL) {
         if (!PyErr_Occurred()) {
             PyErr_SetString(PyExc_ValueError, "interpreter not found");
@@ -1480,13 +1478,37 @@ run_in_subinterp_with_config(PyObject *self, PyObject *args, PyObject *kwargs)
 static PyObject *
 get_interpreter_refcount(PyObject *self, PyObject *idobj)
 {
-    PyInterpreterState *interp = PyInterpreterID_LookUp(idobj);
+    PyInterpreterState *interp = _PyInterpreterState_LookUpIDObject(idobj);
     if (interp == NULL) {
         return NULL;
     }
     return PyLong_FromLongLong(interp->id_refcount);
 }
 
+static PyObject *
+link_interpreter_refcount(PyObject *self, PyObject *idobj)
+{
+    PyInterpreterState *interp = _PyInterpreterState_LookUpIDObject(idobj);
+    if (interp == NULL) {
+        assert(PyErr_Occurred());
+        return NULL;
+    }
+    _PyInterpreterState_RequireIDRef(interp, 1);
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+unlink_interpreter_refcount(PyObject *self, PyObject *idobj)
+{
+    PyInterpreterState *interp = _PyInterpreterState_LookUpIDObject(idobj);
+    if (interp == NULL) {
+        assert(PyErr_Occurred());
+        return NULL;
+    }
+    _PyInterpreterState_RequireIDRef(interp, 0);
+    Py_RETURN_NONE;
+}
+
 
 static void
 _xid_capsule_destructor(PyObject *capsule)
@@ -1728,6 +1750,8 @@ static PyMethodDef module_functions[] = {
      _PyCFunction_CAST(run_in_subinterp_with_config),
      METH_VARARGS | METH_KEYWORDS},
     {"get_interpreter_refcount", get_interpreter_refcount, METH_O},
+    {"link_interpreter_refcount", link_interpreter_refcount,     METH_O},
+    {"unlink_interpreter_refcount", unlink_interpreter_refcount, METH_O},
     {"compile_perf_trampoline_entry", compile_perf_trampoline_entry, METH_VARARGS},
     {"perf_trampoline_set_persist_after_fork", perf_trampoline_set_persist_after_fork, METH_VARARGS},
     {"get_crossinterp_data",    get_crossinterp_data,            METH_VARARGS},

Modules/_xxsubinterpretersmodule.c

@@ -35,83 +35,8 @@ _get_current_interp(void)
     return PyInterpreterState_Get();
 }
 
-static int64_t
-pylong_to_interpid(PyObject *idobj)
-{
-    assert(PyLong_CheckExact(idobj));
+#define look_up_interp _PyInterpreterState_LookUpIDObject
 
-    if (_PyLong_IsNegative((PyLongObject *)idobj)) {
-        PyErr_Format(PyExc_ValueError,
-                     "interpreter ID must be a non-negative int, got %R",
-                     idobj);
-        return -1;
-    }
-
-    int overflow;
-    long long id = PyLong_AsLongLongAndOverflow(idobj, &overflow);
-    if (id == -1) {
-        if (!overflow) {
-            assert(PyErr_Occurred());
-            return -1;
-        }
-        assert(!PyErr_Occurred());
-        // For now, we don't worry about if LLONG_MAX < INT64_MAX.
-        goto bad_id;
-    }
-#if LLONG_MAX > INT64_MAX
-    if (id > INT64_MAX) {
-        goto bad_id;
-    }
-#endif
-    return (int64_t)id;
-
-bad_id:
-    PyErr_Format(PyExc_RuntimeError,
-                 "unrecognized interpreter ID %O", idobj);
-    return -1;
-}
-
-static int64_t
-convert_interpid_obj(PyObject *arg)
-{
-    int64_t id = -1;
-    if (_PyIndex_Check(arg)) {
-        PyObject *idobj = PyNumber_Long(arg);
-        if (idobj == NULL) {
-            return -1;
-        }
-        id = pylong_to_interpid(idobj);
-        Py_DECREF(idobj);
-        if (id < 0) {
-            return -1;
-        }
-    }
-    else {
-        PyErr_Format(PyExc_TypeError,
-                     "interpreter ID must be an int, got %.100s",
-                     Py_TYPE(arg)->tp_name);
-        return -1;
-    }
-    return id;
-}
-
-static PyInterpreterState *
-look_up_interp(PyObject *arg)
-{
-    int64_t id = convert_interpid_obj(arg);
-    if (id < 0) {
-        return NULL;
-    }
-    return _PyInterpreterState_LookUpID(id);
-}
-
-
-static PyObject *
-interpid_to_pylong(int64_t id)
-{
-    assert(id < LLONG_MAX);
-    return PyLong_FromLongLong(id);
-}
 
 static PyObject *
 get_interpid_obj(PyInterpreterState *interp)
@@ -123,7 +48,8 @@ get_interpid_obj(PyInterpreterState *interp)
     if (id < 0) {
         return NULL;
     }
-    return interpid_to_pylong(id);
+    assert(id < LLONG_MAX);
+    return PyLong_FromLongLong(id);
 }
 
 static PyObject *
@@ -699,7 +625,7 @@ interp_set___main___attrs(PyObject *self, PyObject *args)
     }
 
     // Look up the interpreter.
-    PyInterpreterState *interp = PyInterpreterID_LookUp(id);
+    PyInterpreterState *interp = look_up_interp(id);
     if (interp == NULL) {
         return NULL;
     }