[3.11] GH-97779: Ensure that *all* frame objects are backed by "complete" frames (GH-97886)

(cherry picked from commit 0ff8fd65838f9f9ed90d7a055d26a2ce9fc0ce85)

Co-authored-by: Brandt Bucher <brandtbucher@microsoft.com>

1 files changed, 15 insertions, 1 deletions

diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 1ddfec2..f77f5ed 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -590,6 +590,7 @@ first_line_not_before(int *lines, int len, int line)
 static PyFrameState
 _PyFrame_GetState(PyFrameObject *frame)
 {
+    assert(!_PyFrame_IsIncomplete(frame->f_frame));
     if (frame->f_frame->stacktop == 0) {
         return FRAME_CLEARED;
     }
@@ -1063,6 +1064,9 @@ PyFrame_New(PyThreadState *tstate, PyCodeObject *code,
     init_frame((_PyInterpreterFrame *)f->_f_frame_data, func, locals);
     f->f_frame = (_PyInterpreterFrame *)f->_f_frame_data;
     f->f_frame->owner = FRAME_OWNED_BY_FRAME_OBJECT;
+    // This frame needs to be "complete", so pretend that the first RESUME ran:
+    f->f_frame->prev_instr = _PyCode_CODE(code) + code->_co_firsttraceable;
+    assert(!_PyFrame_IsIncomplete(f->f_frame));
     Py_DECREF(func);
     _PyObject_GC_TRACK(f);
     return f;
@@ -1189,6 +1193,7 @@ _PyFrame_FastToLocalsWithError(_PyInterpreterFrame *frame) {
 int
 PyFrame_FastToLocalsWithError(PyFrameObject *f)
 {
+    assert(!_PyFrame_IsIncomplete(f->f_frame));
     if (f == NULL) {
         PyErr_BadInternalCall();
         return -1;
@@ -1204,7 +1209,7 @@ void
 PyFrame_FastToLocals(PyFrameObject *f)
 {
     int res;
-
+    assert(!_PyFrame_IsIncomplete(f->f_frame));
     assert(!PyErr_Occurred());
 
     res = PyFrame_FastToLocalsWithError(f);
@@ -1282,6 +1287,7 @@ _PyFrame_LocalsToFast(_PyInterpreterFrame *frame, int clear)
 void
 PyFrame_LocalsToFast(PyFrameObject *f, int clear)
 {
+    assert(!_PyFrame_IsIncomplete(f->f_frame));
     if (f && f->f_fast_as_locals && _PyFrame_GetState(f) != FRAME_CLEARED) {
         _PyFrame_LocalsToFast(f->f_frame, clear);
         f->f_fast_as_locals = 0;
@@ -1292,6 +1298,7 @@ PyFrame_LocalsToFast(PyFrameObject *f, int clear)
 int _PyFrame_IsEntryFrame(PyFrameObject *frame)
 {
     assert(frame != NULL);
+    assert(!_PyFrame_IsIncomplete(frame->f_frame));
     return frame->f_frame->is_entry;
 }
 
@@ -1300,6 +1307,7 @@ PyCodeObject *
 PyFrame_GetCode(PyFrameObject *frame)
 {
     assert(frame != NULL);
+    assert(!_PyFrame_IsIncomplete(frame->f_frame));
     PyCodeObject *code = frame->f_frame->f_code;
     assert(code != NULL);
     Py_INCREF(code);
@@ -1311,6 +1319,7 @@ PyFrameObject*
 PyFrame_GetBack(PyFrameObject *frame)
 {
     assert(frame != NULL);
+    assert(!_PyFrame_IsIncomplete(frame->f_frame));
     PyFrameObject *back = frame->f_back;
     if (back == NULL) {
         _PyInterpreterFrame *prev = frame->f_frame->previous;
@@ -1328,24 +1337,28 @@ PyFrame_GetBack(PyFrameObject *frame)
 PyObject*
 PyFrame_GetLocals(PyFrameObject *frame)
 {
+    assert(!_PyFrame_IsIncomplete(frame->f_frame));
     return frame_getlocals(frame, NULL);
 }
 
 PyObject*
 PyFrame_GetGlobals(PyFrameObject *frame)
 {
+    assert(!_PyFrame_IsIncomplete(frame->f_frame));
     return frame_getglobals(frame, NULL);
 }
 
 PyObject*
 PyFrame_GetBuiltins(PyFrameObject *frame)
 {
+    assert(!_PyFrame_IsIncomplete(frame->f_frame));
     return frame_getbuiltins(frame, NULL);
 }
 
 int
 PyFrame_GetLasti(PyFrameObject *frame)
 {
+    assert(!_PyFrame_IsIncomplete(frame->f_frame));
     int lasti = _PyInterpreterFrame_LASTI(frame->f_frame);
     if (lasti < 0) {
         return -1;
@@ -1356,6 +1369,7 @@ PyFrame_GetLasti(PyFrameObject *frame)
 PyObject *
 PyFrame_GetGenerator(PyFrameObject *frame)
 {
+    assert(!_PyFrame_IsIncomplete(frame->f_frame));
     if (frame->f_frame->owner != FRAME_OWNED_BY_GENERATOR) {
         return NULL;
     }