GH-100719: Remove redundant `gi_code` field from generator object. (GH-100749)

1 files changed, 55 insertions, 17 deletions

diff --git a/Objects/genobject.c b/Objects/genobject.c
index aec64ca..4ab6581 100644
--- a/Objects/genobject.c
+++ b/Objects/genobject.c
@@ -24,6 +24,21 @@ static const char *NON_INIT_CORO_MSG = "can't send non-None value to a "
 static const char *ASYNC_GEN_IGNORED_EXIT_MSG =
                                  "async generator ignored GeneratorExit";
 
+/* Returns a borrowed reference */
+static inline PyCodeObject *
+_PyGen_GetCode(PyGenObject *gen) {
+    _PyInterpreterFrame *frame = (_PyInterpreterFrame *)(gen->gi_iframe);
+    return frame->f_code;
+}
+
+PyCodeObject *
+PyGen_GetCode(PyGenObject *gen) {
+    assert(PyGen_Check(gen));
+    PyCodeObject *res = _PyGen_GetCode(gen);
+    Py_INCREF(res);
+    return res;
+}
+
 static inline int
 exc_state_traverse(_PyErr_StackItem *exc_state, visitproc visit, void *arg)
 {
@@ -34,7 +49,6 @@ exc_state_traverse(_PyErr_StackItem *exc_state, visitproc visit, void *arg)
 static int
 gen_traverse(PyGenObject *gen, visitproc visit, void *arg)
 {
-    Py_VISIT(gen->gi_code);
     Py_VISIT(gen->gi_name);
     Py_VISIT(gen->gi_qualname);
     if (gen->gi_frame_state < FRAME_CLEARED) {
@@ -88,8 +102,8 @@ _PyGen_Finalize(PyObject *self)
 
     /* If `gen` is a coroutine, and if it was never awaited on,
        issue a RuntimeWarning. */
-    if (gen->gi_code != NULL &&
-        ((PyCodeObject *)gen->gi_code)->co_flags & CO_COROUTINE &&
+    assert(_PyGen_GetCode(gen) != NULL);
+    if (_PyGen_GetCode(gen)->co_flags & CO_COROUTINE &&
         gen->gi_frame_state == FRAME_CREATED)
     {
         _PyErr_WarnUnawaitedCoroutine((PyObject *)gen);
@@ -137,12 +151,12 @@ gen_dealloc(PyGenObject *gen)
         _PyInterpreterFrame *frame = (_PyInterpreterFrame *)gen->gi_iframe;
         gen->gi_frame_state = FRAME_CLEARED;
         frame->previous = NULL;
-        _PyFrame_Clear(frame);
+        _PyFrame_ClearExceptCode(frame);
     }
-    if (((PyCodeObject *)gen->gi_code)->co_flags & CO_COROUTINE) {
+    if (_PyGen_GetCode(gen)->co_flags & CO_COROUTINE) {
         Py_CLEAR(((PyCoroObject *)gen)->cr_origin_or_finalizer);
     }
-    Py_CLEAR(gen->gi_code);
+    Py_DECREF(_PyGen_GetCode(gen));
     Py_CLEAR(gen->gi_name);
     Py_CLEAR(gen->gi_qualname);
     _PyErr_ClearExcState(&gen->gi_exc_state);
@@ -332,7 +346,7 @@ _PyGen_yf(PyGenObject *gen)
             /* Return immediately if the frame didn't start yet. SEND
                always come after LOAD_CONST: a code object should not start
                with SEND */
-            assert(_PyCode_CODE(gen->gi_code)[0].op.code != SEND);
+            assert(_PyCode_CODE(_PyGen_GetCode(gen))[0].op.code != SEND);
             return NULL;
         }
         _Py_CODEUNIT next = frame->prev_instr[1];
@@ -767,6 +781,21 @@ gen_getframe(PyGenObject *gen, void *Py_UNUSED(ignored))
     return _gen_getframe(gen, "gi_frame");
 }
 
+static PyObject *
+_gen_getcode(PyGenObject *gen, const char *const name)
+{
+    if (PySys_Audit("object.__getattr__", "Os", gen, name) < 0) {
+        return NULL;
+    }
+    return Py_NewRef(_PyGen_GetCode(gen));
+}
+
+static PyObject *
+gen_getcode(PyGenObject *gen, void *Py_UNUSED(ignored))
+{
+    return _gen_getcode(gen, "gi_code");
+}
+
 static PyGetSetDef gen_getsetlist[] = {
     {"__name__", (getter)gen_get_name, (setter)gen_set_name,
      PyDoc_STR("name of the generator")},
@@ -777,11 +806,11 @@ static PyGetSetDef gen_getsetlist[] = {
     {"gi_running", (getter)gen_getrunning, NULL, NULL},
     {"gi_frame", (getter)gen_getframe,  NULL, NULL},
     {"gi_suspended", (getter)gen_getsuspended,  NULL, NULL},
+    {"gi_code", (getter)gen_getcode,  NULL, NULL},
     {NULL} /* Sentinel */
 };
 
 static PyMemberDef gen_memberlist[] = {
-    {"gi_code",      T_OBJECT, offsetof(PyGenObject, gi_code),     READONLY|PY_AUDIT_READ},
     {NULL}      /* Sentinel */
 };
 
@@ -790,7 +819,7 @@ gen_sizeof(PyGenObject *gen, PyObject *Py_UNUSED(ignored))
 {
     Py_ssize_t res;
     res = offsetof(PyGenObject, gi_iframe) + offsetof(_PyInterpreterFrame, localsplus);
-    PyCodeObject *code = gen->gi_code;
+    PyCodeObject *code = _PyGen_GetCode(gen);
     res += _PyFrame_NumSlotsForCodeObject(code) * sizeof(PyObject *);
     return PyLong_FromSsize_t(res);
 }
@@ -878,7 +907,6 @@ make_gen(PyTypeObject *type, PyFunctionObject *func)
         return NULL;
     }
     gen->gi_frame_state = FRAME_CLEARED;
-    gen->gi_code = (PyCodeObject *)Py_NewRef(func->func_code);
     gen->gi_weakreflist = NULL;
     gen->gi_exc_state.exc_value = NULL;
     gen->gi_exc_state.previous_item = NULL;
@@ -960,8 +988,6 @@ gen_new_with_qualname(PyTypeObject *type, PyFrameObject *f,
     f->f_frame = frame;
     frame->owner = FRAME_OWNED_BY_GENERATOR;
     assert(PyObject_GC_IsTracked((PyObject *)f));
-    gen->gi_code = PyFrame_GetCode(f);
-    Py_INCREF(gen->gi_code);
     Py_DECREF(f);
     gen->gi_weakreflist = NULL;
     gen->gi_exc_state.exc_value = NULL;
@@ -969,11 +995,11 @@ gen_new_with_qualname(PyTypeObject *type, PyFrameObject *f,
     if (name != NULL)
         gen->gi_name = Py_NewRef(name);
     else
-        gen->gi_name = Py_NewRef(gen->gi_code->co_name);
+        gen->gi_name = Py_NewRef(_PyGen_GetCode(gen)->co_name);
     if (qualname != NULL)
         gen->gi_qualname = Py_NewRef(qualname);
     else
-        gen->gi_qualname = Py_NewRef(gen->gi_code->co_qualname);
+        gen->gi_qualname = Py_NewRef(_PyGen_GetCode(gen)->co_qualname);
     _PyObject_GC_TRACK(gen);
     return (PyObject *)gen;
 }
@@ -1001,7 +1027,7 @@ static int
 gen_is_coroutine(PyObject *o)
 {
     if (PyGen_CheckExact(o)) {
-        PyCodeObject *code = (PyCodeObject *)((PyGenObject*)o)->gi_code;
+        PyCodeObject *code = _PyGen_GetCode((PyGenObject*)o);
         if (code->co_flags & CO_ITERABLE_COROUTINE) {
             return 1;
         }
@@ -1110,6 +1136,12 @@ cr_getframe(PyCoroObject *coro, void *Py_UNUSED(ignored))
     return _gen_getframe((PyGenObject *)coro, "cr_frame");
 }
 
+static PyObject *
+cr_getcode(PyCoroObject *coro, void *Py_UNUSED(ignored))
+{
+    return _gen_getcode((PyGenObject *)coro, "cr_code");
+}
+
 
 static PyGetSetDef coro_getsetlist[] = {
     {"__name__", (getter)gen_get_name, (setter)gen_set_name,
@@ -1120,12 +1152,12 @@ static PyGetSetDef coro_getsetlist[] = {
      PyDoc_STR("object being awaited on, or None")},
     {"cr_running", (getter)cr_getrunning, NULL, NULL},
     {"cr_frame", (getter)cr_getframe, NULL, NULL},
+    {"cr_code", (getter)cr_getcode, NULL, NULL},
     {"cr_suspended", (getter)cr_getsuspended, NULL, NULL},
     {NULL} /* Sentinel */
 };
 
 static PyMemberDef coro_memberlist[] = {
-    {"cr_code",      T_OBJECT, offsetof(PyCoroObject, cr_code),     READONLY|PY_AUDIT_READ},
     {"cr_origin",    T_OBJECT, offsetof(PyCoroObject, cr_origin_or_finalizer),   READONLY},
     {NULL}      /* Sentinel */
 };
@@ -1514,6 +1546,12 @@ ag_getframe(PyAsyncGenObject *ag, void *Py_UNUSED(ignored))
     return _gen_getframe((PyGenObject *)ag, "ag_frame");
 }
 
+static PyObject *
+ag_getcode(PyGenObject *gen, void *Py_UNUSED(ignored))
+{
+    return _gen_getcode(gen, "ag__code");
+}
+
 static PyGetSetDef async_gen_getsetlist[] = {
     {"__name__", (getter)gen_get_name, (setter)gen_set_name,
      PyDoc_STR("name of the async generator")},
@@ -1522,13 +1560,13 @@ static PyGetSetDef async_gen_getsetlist[] = {
     {"ag_await", (getter)coro_get_cr_await, NULL,
      PyDoc_STR("object being awaited on, or None")},
      {"ag_frame",  (getter)ag_getframe, NULL, NULL},
+     {"ag_code",  (getter)ag_getcode, NULL, NULL},
     {NULL} /* Sentinel */
 };
 
 static PyMemberDef async_gen_memberlist[] = {
     {"ag_running", T_BOOL,   offsetof(PyAsyncGenObject, ag_running_async),
         READONLY},
-    {"ag_code",    T_OBJECT, offsetof(PyAsyncGenObject, ag_code),    READONLY|PY_AUDIT_READ},
     {NULL}      /* Sentinel */
 };