8 files changed, 448 insertions, 0 deletions

diff --git a/Lib/test/test_generated_cases.py b/Lib/test/test_generated_cases.py
index 41eeb9c..71a5711 100644
--- a/Lib/test/test_generated_cases.py
+++ b/Lib/test/test_generated_cases.py
@@ -151,6 +151,7 @@ class TestGeneratedCases(unittest.TestCase):
             value = stack_pointer[-1];
             spam();
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
     """
@@ -171,6 +172,7 @@ class TestGeneratedCases(unittest.TestCase):
             spam();
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
     """
@@ -216,6 +218,7 @@ class TestGeneratedCases(unittest.TestCase):
             spam();
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
     """
@@ -337,6 +340,7 @@ class TestGeneratedCases(unittest.TestCase):
             if (cond) goto pop_2_label;
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
     """
@@ -360,6 +364,7 @@ class TestGeneratedCases(unittest.TestCase):
             uint32_t extra = read_u32(&this_instr[2].cache);
             (void)extra;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
     """
@@ -425,6 +430,7 @@ class TestGeneratedCases(unittest.TestCase):
             }
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -459,6 +465,7 @@ class TestGeneratedCases(unittest.TestCase):
             res = op3(arg2, left, right);
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
     """
@@ -540,6 +547,7 @@ class TestGeneratedCases(unittest.TestCase):
             below = stack_pointer[-2 - oparg*2];
             spam();
             stack_pointer += -2 - oparg*2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
     """
@@ -564,6 +572,7 @@ class TestGeneratedCases(unittest.TestCase):
             stack_pointer[-2] = below;
             stack_pointer[-1 + oparg*3] = above;
             stack_pointer += oparg*3;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
     """
@@ -586,6 +595,7 @@ class TestGeneratedCases(unittest.TestCase):
             spam(values, oparg);
             stack_pointer[0] = above;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
     """
@@ -608,6 +618,7 @@ class TestGeneratedCases(unittest.TestCase):
             extra = stack_pointer[-1 - oparg];
             if (oparg == 0) { stack_pointer += -1 - oparg; goto somewhere; }
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
     """
@@ -638,6 +649,7 @@ class TestGeneratedCases(unittest.TestCase):
             if (oparg & 2) stack_pointer[-1 - (((oparg & 1) == 1) ? 1 : 0)] = output;
             stack_pointer[-1 - (((oparg & 1) == 1) ? 1 : 0) + ((oparg & 2) ? 1 : 0)] = zz;
             stack_pointer += -(((oparg & 1) == 1) ? 1 : 0) + ((oparg & 2) ? 1 : 0);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
     """
@@ -679,6 +691,7 @@ class TestGeneratedCases(unittest.TestCase):
             if (oparg) stack_pointer[-2] = extra;
             stack_pointer[-2 + ((oparg) ? 1 : 0)] = res;
             stack_pointer += -1 + ((oparg) ? 1 : 0);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
     """
@@ -712,6 +725,7 @@ class TestGeneratedCases(unittest.TestCase):
             stack_pointer[0] = val1;
             stack_pointer[1] = val2;
             stack_pointer += 2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
         """
diff --git a/Python/ceval_macros.h b/Python/ceval_macros.h
index 50941e4..e924784 100644
--- a/Python/ceval_macros.h
+++ b/Python/ceval_macros.h
@@ -246,6 +246,8 @@ GETITEM(PyObject *v, Py_ssize_t i) {
 #define STACK_SHRINK(n)        BASIC_STACKADJ(-(n))
 #endif
 
+#define WITHIN_STACK_BOUNDS() \
+   (frame == &entry_frame || (STACK_LEVEL() >= 0 && STACK_LEVEL() <= STACK_SIZE()))
 
 /* Data access macros */
 #define FRAME_CO_CONSTS (_PyFrame_GetCode(frame)->co_consts)
diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h
index 8de0309..6bee9b0 100644
--- a/Python/executor_cases.c.h
+++ b/Python/executor_cases.c.h
@@ -46,6 +46,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -58,6 +59,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -70,6 +72,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -82,6 +85,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -94,6 +98,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -106,6 +111,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -118,6 +124,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -130,6 +137,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -142,6 +150,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -153,6 +162,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -164,6 +174,7 @@
             GETLOCAL(oparg) = NULL;
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -174,6 +185,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -184,6 +196,7 @@
             value = stack_pointer[-1];
             SETLOCAL(oparg, value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -194,6 +207,7 @@
             value = stack_pointer[-1];
             SETLOCAL(oparg, value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -204,6 +218,7 @@
             value = stack_pointer[-1];
             SETLOCAL(oparg, value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -214,6 +229,7 @@
             value = stack_pointer[-1];
             SETLOCAL(oparg, value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -224,6 +240,7 @@
             value = stack_pointer[-1];
             SETLOCAL(oparg, value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -234,6 +251,7 @@
             value = stack_pointer[-1];
             SETLOCAL(oparg, value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -244,6 +262,7 @@
             value = stack_pointer[-1];
             SETLOCAL(oparg, value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -254,6 +273,7 @@
             value = stack_pointer[-1];
             SETLOCAL(oparg, value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -263,6 +283,7 @@
             value = stack_pointer[-1];
             SETLOCAL(oparg, value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -271,6 +292,7 @@
             value = stack_pointer[-1];
             Py_DECREF(value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -279,6 +301,7 @@
             res = NULL;
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -290,6 +313,7 @@
             Py_DECREF(receiver);
             stack_pointer[-2] = value;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -480,6 +504,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -496,6 +521,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -512,6 +538,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -564,6 +591,7 @@
             DECREF_INPUTS_AND_REUSE_FLOAT(left, right, dres, res);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -580,6 +608,7 @@
             DECREF_INPUTS_AND_REUSE_FLOAT(left, right, dres, res);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -596,6 +625,7 @@
             DECREF_INPUTS_AND_REUSE_FLOAT(left, right, dres, res);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -628,6 +658,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -643,6 +674,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -668,6 +700,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -693,6 +726,7 @@
             Py_DECREF(container);
             if (err) JUMP_TO_ERROR();
             stack_pointer += -4;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -728,6 +762,7 @@
             Py_DECREF(list);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -766,6 +801,7 @@
             Py_DECREF(str);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -801,6 +837,7 @@
             Py_DECREF(tuple);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -825,6 +862,7 @@
             // not found or error
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -838,6 +876,7 @@
             list = stack_pointer[-2 - (oparg-1)];
             if (_PyList_AppendTakeRef((PyListObject *)list, v) < 0) JUMP_TO_ERROR();
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -851,6 +890,7 @@
             Py_DECREF(v);
             if (err) JUMP_TO_ERROR();
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -868,6 +908,7 @@
             Py_DECREF(sub);
             if (err) JUMP_TO_ERROR();
             stack_pointer += -3;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -905,6 +946,7 @@
             _Py_DECREF_SPECIALIZED(sub, (destructor)PyObject_Free);
             Py_DECREF(list);
             stack_pointer += -3;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -924,6 +966,7 @@
             Py_DECREF(dict);
             if (err) JUMP_TO_ERROR();
             stack_pointer += -3;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -938,6 +981,7 @@
             Py_DECREF(sub);
             if (err) JUMP_TO_ERROR();
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -968,6 +1012,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -979,6 +1024,7 @@
             assert(frame != &entry_frame);
             #endif
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             _PyFrame_SetStackPointer(frame, stack_pointer);
             assert(EMPTY());
             _Py_LeaveRecursiveCallPy(tstate);
@@ -992,6 +1038,7 @@
             LLTRACE_RESUME_FRAME();
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1076,6 +1123,7 @@
             }
             stack_pointer[0] = awaitable;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1130,6 +1178,7 @@
             assert(oparg == 0 || oparg == 1);
             gen->gi_frame_state = FRAME_SUSPENDED + oparg;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             _PyFrame_SetStackPointer(frame, stack_pointer);
             tstate->exc_info = gen->gi_exc_state.previous_item;
             gen->gi_exc_state.previous_item = NULL;
@@ -1153,6 +1202,7 @@
             LLTRACE_RESUME_FRAME();
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1162,6 +1212,7 @@
             _PyErr_StackItem *exc_info = tstate->exc_info;
             Py_XSETREF(exc_info->exc_value, exc_value == Py_None ? NULL : exc_value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1181,6 +1232,7 @@
             }
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1194,6 +1246,7 @@
             }
             stack_pointer[0] = bc;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1217,6 +1270,7 @@
             Py_DECREF(v);
             if (err) JUMP_TO_ERROR();
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1250,6 +1304,7 @@
             Py_DECREF(seq);
             if (res == 0) JUMP_TO_ERROR();
             stack_pointer += -1 + oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1275,6 +1330,7 @@
             stack_pointer[-1] = val1;
             stack_pointer[0] = val0;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1299,6 +1355,7 @@
             }
             Py_DECREF(seq);
             stack_pointer += -1 + oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1323,6 +1380,7 @@
             }
             Py_DECREF(seq);
             stack_pointer += -1 + oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1336,6 +1394,7 @@
             Py_DECREF(seq);
             if (res == 0) JUMP_TO_ERROR();
             stack_pointer += (oparg >> 8) + (oparg & 0xFF);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1351,6 +1410,7 @@
             Py_DECREF(owner);
             if (err) JUMP_TO_ERROR();
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1363,6 +1423,7 @@
             Py_DECREF(owner);
             if (err) JUMP_TO_ERROR();
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1375,6 +1436,7 @@
             Py_DECREF(v);
             if (err) JUMP_TO_ERROR();
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1405,6 +1467,7 @@
             Py_INCREF(locals);
             stack_pointer[0] = locals;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1452,6 +1515,7 @@
             stack_pointer[0] = res;
             if (oparg & 1) stack_pointer[1] = null;
             stack_pointer += 1 + (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1503,6 +1567,7 @@
             stack_pointer[0] = res;
             if (oparg & 1) stack_pointer[1] = null;
             stack_pointer += 1 + (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1524,6 +1589,7 @@
             stack_pointer[0] = res;
             if (oparg & 1) stack_pointer[1] = null;
             stack_pointer += 1 + (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1604,6 +1670,7 @@
             }
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1614,6 +1681,7 @@
             PyCellObject *cell = (PyCellObject *)GETLOCAL(oparg);
             PyCell_SetTakeRef(cell, v);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1644,6 +1712,7 @@
             if (str == NULL) JUMP_TO_ERROR();
             stack_pointer[-oparg] = str;
             stack_pointer += 1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1656,6 +1725,7 @@
             if (tup == NULL) JUMP_TO_ERROR();
             stack_pointer[-oparg] = tup;
             stack_pointer += 1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1668,6 +1738,7 @@
             if (list == NULL) JUMP_TO_ERROR();
             stack_pointer[-oparg] = list;
             stack_pointer += 1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1693,6 +1764,7 @@
             assert(Py_IsNone(none_val));
             Py_DECREF(iterable);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1706,6 +1778,7 @@
             Py_DECREF(iterable);
             if (err < 0) JUMP_TO_ERROR();
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1726,6 +1799,7 @@
             if (map == NULL) JUMP_TO_ERROR();
             stack_pointer[-oparg*2] = map;
             stack_pointer += 1 - oparg*2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1772,6 +1846,7 @@
             if (map == NULL) JUMP_TO_ERROR();
             stack_pointer[-1 - oparg] = map;
             stack_pointer += -oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1792,6 +1867,7 @@
             }
             Py_DECREF(update);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1810,6 +1886,7 @@
             }
             Py_DECREF(update);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1826,6 +1903,7 @@
             // Do not DECREF INPUTS because the function steals the references
             if (_PyDict_SetItem_Take2((PyDictObject *)dict, key, value) != 0) JUMP_TO_ERROR();
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1858,6 +1936,7 @@
             if (attr == NULL) JUMP_TO_ERROR();
             stack_pointer[-3] = attr;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1901,6 +1980,7 @@
             stack_pointer[-3] = attr;
             stack_pointer[-2] = self_or_null;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1943,6 +2023,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = self_or_null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2010,6 +2091,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = null;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2055,6 +2137,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2111,6 +2194,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2155,6 +2239,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = null;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2207,6 +2292,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = null;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2251,6 +2337,7 @@
             }
             Py_DECREF(owner);
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2313,6 +2400,7 @@
             dict->ma_version_tag = new_version;
             Py_DECREF(owner);
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2329,6 +2417,7 @@
             Py_XDECREF(old_value);
             Py_DECREF(owner);
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2352,6 +2441,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2373,6 +2463,7 @@
             // It's always a bool, so we don't care about oparg & 16.
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2404,6 +2495,7 @@
             // It's always a bool, so we don't care about oparg & 16.
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2426,6 +2518,7 @@
             // It's always a bool, so we don't care about oparg & 16.
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2442,6 +2535,7 @@
             b = res ? Py_True : Py_False;
             stack_pointer[-2] = b;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2459,6 +2553,7 @@
             b = (res ^ oparg) ? Py_True : Py_False;
             stack_pointer[-2] = b;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2482,6 +2577,7 @@
             b = (res ^ oparg) ? Py_True : Py_False;
             stack_pointer[-2] = b;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2504,6 +2600,7 @@
             b = (res ^ oparg) ? Py_True : Py_False;
             stack_pointer[-2] = b;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2584,6 +2681,7 @@
             if (len_o == NULL) JUMP_TO_ERROR();
             stack_pointer[0] = len_o;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2613,6 +2711,7 @@
             }
             stack_pointer[-3] = attrs;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2624,6 +2723,7 @@
             res = match ? Py_True : Py_False;
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2635,6 +2735,7 @@
             res = match ? Py_True : Py_False;
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2649,6 +2750,7 @@
             if (values_or_none == NULL) JUMP_TO_ERROR();
             stack_pointer[0] = values_or_none;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2721,6 +2823,7 @@
             // Common case: no jump, leave it to the code generator
             stack_pointer[0] = next;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2767,6 +2870,7 @@
             next = Py_NewRef(PyList_GET_ITEM(seq, it->it_index++));
             stack_pointer[0] = next;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2811,6 +2915,7 @@
             next = Py_NewRef(PyTuple_GET_ITEM(seq, it->it_index++));
             stack_pointer[0] = next;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2853,6 +2958,7 @@
             if (next == NULL) JUMP_TO_ERROR();
             stack_pointer[0] = next;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2880,6 +2986,7 @@
             frame->return_offset = (uint16_t)(1 + INLINE_CACHE_ENTRIES_FOR_ITER + oparg);
             stack_pointer[0] = (PyObject *)gen_frame;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2903,6 +3010,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self_or_null;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2944,6 +3052,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2963,6 +3072,7 @@
             stack_pointer[-1] = prev_exc;
             stack_pointer[0] = new_exc;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3007,6 +3117,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3027,6 +3138,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3091,6 +3203,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3128,11 +3241,13 @@
             // The frame has stolen all the arguments from the stack,
             // so there is no need to clean them up.
             stack_pointer += -2 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             if (new_frame == NULL) {
                 JUMP_TO_ERROR();
             }
             stack_pointer[0] = (PyObject *)new_frame;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3247,6 +3362,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3346,6 +3462,7 @@
             }
             stack_pointer[-2 - oparg] = (PyObject *)new_frame;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3370,6 +3487,7 @@
             }
             stack_pointer[-2 - oparg] = (PyObject *)new_frame;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3394,6 +3512,7 @@
             }
             stack_pointer[-2 - oparg] = (PyObject *)new_frame;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3418,6 +3537,7 @@
             }
             stack_pointer[-2 - oparg] = (PyObject *)new_frame;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3442,6 +3562,7 @@
             }
             stack_pointer[-2 - oparg] = (PyObject *)new_frame;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3465,6 +3586,7 @@
             }
             stack_pointer[-2 - oparg] = (PyObject *)new_frame;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3475,6 +3597,7 @@
             // Eventually this should be the only occurrence of this code.
             assert(tstate->interp->eval_frame == NULL);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             _PyFrame_SetStackPointer(frame, stack_pointer);
             new_frame->previous = frame;
             CALL_STAT_INC(inlined_py_calls);
@@ -3509,6 +3632,7 @@
             Py_DECREF(arg);
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3536,6 +3660,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3563,6 +3688,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3579,6 +3705,7 @@
                 JUMP_TO_ERROR();
             }
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3615,6 +3742,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3662,6 +3790,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3704,6 +3833,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3745,6 +3875,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3787,6 +3918,7 @@
             Py_DECREF(arg);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3831,6 +3963,7 @@
             Py_DECREF(callable);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3885,6 +4018,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3932,6 +4066,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -3985,6 +4120,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4032,6 +4168,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4097,6 +4234,7 @@
             }
             stack_pointer[-2] = func;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4126,6 +4264,7 @@
             LLTRACE_RESUME_FRAME();
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4145,6 +4284,7 @@
             if (slice == NULL) JUMP_TO_ERROR();
             stack_pointer[-2 - ((oparg == 3) ? 1 : 0)] = slice;
             stack_pointer += -1 - ((oparg == 3) ? 1 : 0);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4193,6 +4333,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4205,6 +4346,7 @@
             top = Py_NewRef(bottom);
             stack_pointer[0] = top;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4222,6 +4364,7 @@
             if (res == NULL) JUMP_TO_ERROR();
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4255,6 +4398,7 @@
             PyObject *flag;
             flag = stack_pointer[-1];
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             if (!Py_IsTrue(flag)) {
                 UOP_STAT_INC(uopcode, miss);
                 JUMP_TO_JUMP_TARGET();
@@ -4267,6 +4411,7 @@
             PyObject *flag;
             flag = stack_pointer[-1];
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             if (!Py_IsFalse(flag)) {
                 UOP_STAT_INC(uopcode, miss);
                 JUMP_TO_JUMP_TARGET();
@@ -4279,6 +4424,7 @@
             PyObject *val;
             val = stack_pointer[-1];
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             if (!Py_IsNone(val)) {
                 Py_DECREF(val);
                 if (1) {
@@ -4293,6 +4439,7 @@
             PyObject *val;
             val = stack_pointer[-1];
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             if (Py_IsNone(val)) {
                 UOP_STAT_INC(uopcode, miss);
                 JUMP_TO_JUMP_TARGET();
@@ -4356,6 +4503,7 @@
             value = Py_NewRef(ptr);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4365,6 +4513,7 @@
             value = ptr;
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4388,6 +4537,7 @@
             stack_pointer[0] = value;
             stack_pointer[1] = null;
             stack_pointer += 2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4400,6 +4550,7 @@
             stack_pointer[0] = value;
             stack_pointer[1] = null;
             stack_pointer += 2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4419,6 +4570,7 @@
             _PyCounterOptimizerObject *exe = (_PyCounterOptimizerObject *)opt;
             exe->count++;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -4532,6 +4684,7 @@
             uint32_t target = (uint32_t)CURRENT_OPERAND();
             frame->instr_ptr = ((_Py_CODEUNIT *)_PyFrame_GetCode(frame)->co_code_adaptive) + target;
             stack_pointer += -oparg;
+            assert(WITHIN_STACK_BOUNDS());
             GOTO_UNWIND();
             break;
         }
diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
index 327a704..2d23b43 100644
--- a/Python/generated_cases.c.h
+++ b/Python/generated_cases.c.h
@@ -47,6 +47,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -76,6 +77,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -105,6 +107,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -134,6 +137,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -179,6 +183,7 @@
                 SKIP_OVER(1);
             }
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -208,6 +213,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -237,6 +243,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -266,6 +273,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -295,6 +303,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -323,6 +332,7 @@
             if (res == NULL) goto pop_3_error;
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -361,6 +371,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -387,6 +398,7 @@
             // not found or error
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -448,6 +460,7 @@
             Py_DECREF(list);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -476,6 +489,7 @@
             Py_DECREF(str);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -504,6 +518,7 @@
             Py_DECREF(tuple);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -528,6 +543,7 @@
             if (map == NULL) { stack_pointer += -1 - oparg; goto error; }
             stack_pointer[-1 - oparg] = map;
             stack_pointer += -oparg;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -542,6 +558,7 @@
             if (list == NULL) { stack_pointer += -oparg; goto error; }
             stack_pointer[-oparg] = list;
             stack_pointer += 1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -562,6 +579,7 @@
             if (map == NULL) { stack_pointer += -oparg*2; goto error; }
             stack_pointer[-oparg*2] = map;
             stack_pointer += 1 - oparg*2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -588,6 +606,7 @@
             }
             stack_pointer[-oparg] = set;
             stack_pointer += 1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -609,6 +628,7 @@
             if (slice == NULL) { stack_pointer += -2 - ((oparg == 3) ? 1 : 0); goto error; }
             stack_pointer[-2 - ((oparg == 3) ? 1 : 0)] = slice;
             stack_pointer += -1 - ((oparg == 3) ? 1 : 0);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -626,6 +646,7 @@
             if (str == NULL) { stack_pointer += -oparg; goto error; }
             stack_pointer[-oparg] = str;
             stack_pointer += 1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -640,6 +661,7 @@
             if (tup == NULL) { stack_pointer += -oparg; goto error; }
             stack_pointer[-oparg] = tup;
             stack_pointer += 1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -754,6 +776,7 @@
             }
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -906,6 +929,7 @@
                 // Eventually this should be the only occurrence of this code.
                 assert(tstate->interp->eval_frame == NULL);
                 stack_pointer += -2 - oparg;
+                assert(WITHIN_STACK_BOUNDS());
                 _PyFrame_SetStackPointer(frame, stack_pointer);
                 new_frame->previous = frame;
                 CALL_STAT_INC(inlined_py_calls);
@@ -979,6 +1003,7 @@
                 // The frame has stolen all the arguments from the stack,
                 // so there is no need to clean them up.
                 stack_pointer += -2 - oparg;
+                assert(WITHIN_STACK_BOUNDS());
                 if (new_frame == NULL) {
                     goto error;
                 }
@@ -1047,6 +1072,7 @@
             }
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -1095,6 +1121,7 @@
             }
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -1142,6 +1169,7 @@
             }
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -1189,6 +1217,7 @@
             }
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -1275,6 +1304,7 @@
             if (result == NULL) { stack_pointer += -3 - (oparg & 1); goto error; }
             stack_pointer[-3 - (oparg & 1)] = result;
             stack_pointer += -2 - (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -1310,6 +1340,7 @@
             if (res == NULL) goto pop_2_error;
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -1353,6 +1384,7 @@
             Py_DECREF(callable);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -1443,6 +1475,7 @@
             if (res == NULL) { stack_pointer += -3 - oparg; goto error; }
             stack_pointer[-3 - oparg] = res;
             stack_pointer += -2 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -1485,6 +1518,7 @@
             Py_DECREF(arg);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -1565,6 +1599,7 @@
             }
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -1615,6 +1650,7 @@
             }
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -1665,6 +1701,7 @@
             }
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -1716,6 +1753,7 @@
             }
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -1766,6 +1804,7 @@
             }
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -1836,6 +1875,7 @@
                 // Eventually this should be the only occurrence of this code.
                 assert(tstate->interp->eval_frame == NULL);
                 stack_pointer += -2 - oparg;
+                assert(WITHIN_STACK_BOUNDS());
                 _PyFrame_SetStackPointer(frame, stack_pointer);
                 new_frame->previous = frame;
                 CALL_STAT_INC(inlined_py_calls);
@@ -1890,6 +1930,7 @@
                 // The frame has stolen all the arguments from the stack,
                 // so there is no need to clean them up.
                 stack_pointer += -2 - oparg;
+                assert(WITHIN_STACK_BOUNDS());
                 if (new_frame == NULL) {
                     goto error;
                 }
@@ -1949,6 +1990,7 @@
             }
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -1982,6 +2024,7 @@
             }
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             CHECK_EVAL_BREAKER();
             DISPATCH();
         }
@@ -2008,6 +2051,7 @@
             Py_DECREF(arg);
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2094,6 +2138,7 @@
             stack_pointer[-3] = none;
             stack_pointer[-2] = value;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2139,6 +2184,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2172,6 +2218,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2209,6 +2256,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2243,6 +2291,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2282,6 +2331,7 @@
             }
             stack_pointer[-2] = b;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2305,6 +2355,7 @@
             b = (res ^ oparg) ? Py_True : Py_False;
             stack_pointer[-2] = b;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2329,6 +2380,7 @@
             b = (res ^ oparg) ? Py_True : Py_False;
             stack_pointer[-2] = b;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2360,6 +2412,7 @@
             top = Py_NewRef(bottom);
             stack_pointer[0] = top;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2391,6 +2444,7 @@
             Py_DECREF(owner);
             if (err) goto pop_1_error;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2481,6 +2535,7 @@
             Py_DECREF(sub);
             if (err) goto pop_2_error;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2501,6 +2556,7 @@
             }
             Py_DECREF(update);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2523,6 +2579,7 @@
             }
             Py_DECREF(update);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2547,6 +2604,7 @@
                 goto exception_unwind;
             }
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2558,6 +2616,7 @@
             value = stack_pointer[-1];
             Py_DECREF(value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2572,6 +2631,7 @@
             Py_DECREF(receiver);
             stack_pointer[-2] = value;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2622,6 +2682,7 @@
                 goto error;
             }
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2672,6 +2733,7 @@
             if (res == NULL) goto pop_2_error;
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2724,6 +2786,7 @@
             }
             stack_pointer[0] = next;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2818,6 +2881,7 @@
             }
             stack_pointer[0] = next;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2861,6 +2925,7 @@
             }
             stack_pointer[0] = next;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2906,6 +2971,7 @@
             }
             stack_pointer[0] = next;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -2992,6 +3058,7 @@
             }
             stack_pointer[0] = awaitable;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3054,6 +3121,7 @@
             if (len_o == NULL) goto error;
             stack_pointer[0] = len_o;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3104,6 +3172,7 @@
             if (res == NULL) goto error;
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3123,6 +3192,7 @@
             if (res == NULL) goto pop_2_error;
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3187,6 +3257,7 @@
             }
             Py_DECREF(value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3207,6 +3278,7 @@
             Py_DECREF(receiver);
             stack_pointer[-2] = value;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3513,6 +3585,7 @@
             b = res ? Py_True : Py_False;
             stack_pointer[-2] = b;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3586,6 +3659,7 @@
             list = stack_pointer[-2 - (oparg-1)];
             if (_PyList_AppendTakeRef((PyListObject *)list, v) < 0) goto pop_1_error;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3613,6 +3687,7 @@
             assert(Py_IsNone(none_val));
             Py_DECREF(iterable);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3679,6 +3754,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = self_or_null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3712,6 +3788,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3787,6 +3864,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3829,6 +3907,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3864,6 +3943,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3910,6 +3990,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -3949,6 +4030,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4089,6 +4171,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4142,6 +4225,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4158,6 +4242,7 @@
             }
             stack_pointer[0] = bc;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4179,6 +4264,7 @@
             }
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4191,6 +4277,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4207,6 +4294,7 @@
             }
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4220,6 +4308,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4233,6 +4322,7 @@
             GETLOCAL(oparg) = NULL;
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4252,6 +4342,7 @@
             Py_INCREF(value);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4270,6 +4361,7 @@
             stack_pointer[0] = value1;
             stack_pointer[1] = value2;
             stack_pointer += 2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4415,6 +4507,7 @@
             stack_pointer[0] = res;
             if (oparg & 1) stack_pointer[1] = null;
             stack_pointer += 1 + (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4456,6 +4549,7 @@
             stack_pointer[0] = res;
             if (oparg & 1) stack_pointer[1] = null;
             stack_pointer += 1 + (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4490,6 +4584,7 @@
             stack_pointer[0] = res;
             if (oparg & 1) stack_pointer[1] = null;
             stack_pointer += 1 + (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4507,6 +4602,7 @@
             Py_INCREF(locals);
             stack_pointer[0] = locals;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4543,6 +4639,7 @@
             }
             stack_pointer[0] = v;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4568,6 +4665,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self_or_null;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4643,6 +4741,7 @@
             stack_pointer[-3] = attr;
             if (oparg & 1) stack_pointer[-2] = null;
             stack_pointer += -2 + (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4671,6 +4770,7 @@
             if (attr == NULL) goto pop_3_error;
             stack_pointer[-3] = attr;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4712,6 +4812,7 @@
             stack_pointer[-3] = attr;
             stack_pointer[-2] = self_or_null;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4765,6 +4866,7 @@
             // Do not DECREF INPUTS because the function steals the references
             if (_PyDict_SetItem_Take2((PyDictObject *)dict, key, value) != 0) goto pop_2_error;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4796,6 +4898,7 @@
             }
             stack_pointer[-3] = attrs;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4813,6 +4916,7 @@
             if (values_or_none == NULL) goto error;
             stack_pointer[0] = values_or_none;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4827,6 +4931,7 @@
             res = match ? Py_True : Py_False;
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4841,6 +4946,7 @@
             res = match ? Py_True : Py_False;
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4860,6 +4966,7 @@
             _PyErr_StackItem *exc_info = tstate->exc_info;
             Py_XSETREF(exc_info->exc_value, exc_value == Py_None ? NULL : exc_value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4878,6 +4985,7 @@
             #endif
             JUMPBY(oparg * flag);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4912,6 +5020,7 @@
                 JUMPBY(oparg * flag);
             }
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4946,6 +5055,7 @@
                 JUMPBY(oparg * flag);
             }
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4964,6 +5074,7 @@
             #endif
             JUMPBY(oparg * flag);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4975,6 +5086,7 @@
             value = stack_pointer[-1];
             Py_DECREF(value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -4997,6 +5109,7 @@
             stack_pointer[-1] = prev_exc;
             stack_pointer[0] = new_exc;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5008,6 +5121,7 @@
             res = NULL;
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5164,6 +5278,7 @@
             }
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5196,6 +5311,7 @@
             LLTRACE_RESUME_FRAME();
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5210,6 +5326,7 @@
             assert(frame != &entry_frame);
             #endif
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             _PyFrame_SetStackPointer(frame, stack_pointer);
             assert(EMPTY());
             _Py_LeaveRecursiveCallPy(tstate);
@@ -5223,6 +5340,7 @@
             LLTRACE_RESUME_FRAME();
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5360,6 +5478,7 @@
             Py_DECREF(v);
             if (err) goto pop_1_error;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5402,6 +5521,7 @@
             }
             stack_pointer[-2] = func;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5417,6 +5537,7 @@
             Py_DECREF(iterable);
             if (err < 0) goto pop_1_error;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5456,6 +5577,7 @@
                 if (err) goto pop_2_error;
             }
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5500,6 +5622,7 @@
                 Py_DECREF(owner);
             }
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5531,6 +5654,7 @@
                 Py_DECREF(owner);
             }
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5589,6 +5713,7 @@
                 Py_DECREF(owner);
             }
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5601,6 +5726,7 @@
             PyCellObject *cell = (PyCellObject *)GETLOCAL(oparg);
             PyCell_SetTakeRef(cell, v);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5612,6 +5738,7 @@
             value = stack_pointer[-1];
             SETLOCAL(oparg, value);
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5644,6 +5771,7 @@
             SETLOCAL(oparg1, value1);
             SETLOCAL(oparg2, value2);
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5658,6 +5786,7 @@
             Py_DECREF(v);
             if (err) goto pop_1_error;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5683,6 +5812,7 @@
             Py_DECREF(v);
             if (err) goto pop_1_error;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5711,6 +5841,7 @@
             Py_DECREF(container);
             if (err) goto pop_4_error;
             stack_pointer += -4;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5751,6 +5882,7 @@
                 if (err) goto pop_3_error;
             }
             stack_pointer += -3;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5772,6 +5904,7 @@
             Py_DECREF(dict);
             if (err) goto pop_3_error;
             stack_pointer += -3;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -5802,6 +5935,7 @@
             _Py_DECREF_SPECIALIZED(sub, (destructor)PyObject_Free);
             Py_DECREF(list);
             stack_pointer += -3;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -6034,6 +6168,7 @@
             Py_DECREF(seq);
             if (res == 0) goto pop_1_error;
             stack_pointer += (oparg >> 8) + (oparg & 0xFF);
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -6070,6 +6205,7 @@
                 if (res == 0) goto pop_1_error;
             }
             stack_pointer += -1 + oparg;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -6092,6 +6228,7 @@
             }
             Py_DECREF(seq);
             stack_pointer += -1 + oparg;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -6114,6 +6251,7 @@
             }
             Py_DECREF(seq);
             stack_pointer += -1 + oparg;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -6137,6 +6275,7 @@
             stack_pointer[-1] = val1;
             stack_pointer[0] = val0;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -6181,6 +6320,7 @@
             if (res == NULL) goto error;
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 
@@ -6203,6 +6343,7 @@
             assert(oparg == 0 || oparg == 1);
             gen->gi_frame_state = FRAME_SUSPENDED + oparg;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             _PyFrame_SetStackPointer(frame, stack_pointer);
             tstate->exc_info = gen->gi_exc_state.previous_item;
             gen->gi_exc_state.previous_item = NULL;
@@ -6226,6 +6367,7 @@
             LLTRACE_RESUME_FRAME();
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             DISPATCH();
         }
 #undef TIER_ONE
diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index 0e45bd8..bbddbc8 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -301,6 +301,11 @@ remove_globals(_PyInterpreterFrame *frame, _PyUOpInstruction *buffer,
 
 
 #define STACK_LEVEL()     ((int)(stack_pointer - ctx->frame->stack))
+#define STACK_SIZE()      ((int)(ctx->frame->stack_len))
+
+#define WITHIN_STACK_BOUNDS() \
+    (STACK_LEVEL() >= 0 && STACK_LEVEL() <= STACK_SIZE())
+
 
 #define GETLOCAL(idx)          ((ctx->frame->locals[idx]))
 
diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h
index 7274bd2..c4f310d 100644
--- a/Python/optimizer_cases.c.h
+++ b/Python/optimizer_cases.c.h
@@ -22,6 +22,7 @@
             }
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -30,6 +31,7 @@
             value = GETLOCAL(oparg);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -40,6 +42,7 @@
             GETLOCAL(oparg) = temp;
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -51,6 +54,7 @@
             value = sym_new_const(ctx, val);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -59,11 +63,13 @@
             value = stack_pointer[-1];
             GETLOCAL(oparg) = value;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _POP_TOP: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -72,6 +78,7 @@
             res = sym_new_null(ctx);
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -80,6 +87,7 @@
             value = sym_new_not_null(ctx);
             stack_pointer[-2] = value;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -239,6 +247,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -268,6 +277,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -297,6 +307,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -358,6 +369,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -388,6 +400,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -418,6 +431,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -455,6 +469,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -463,6 +478,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -471,11 +487,13 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _STORE_SLICE: {
             stack_pointer += -4;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -484,6 +502,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -492,6 +511,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -500,6 +520,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -508,6 +529,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -515,31 +537,37 @@
 
         case _LIST_APPEND: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _SET_ADD: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _STORE_SUBSCR: {
             stack_pointer += -3;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _STORE_SUBSCR_LIST_INT: {
             stack_pointer += -3;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _STORE_SUBSCR_DICT: {
             stack_pointer += -3;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _DELETE_SUBSCR: {
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -555,6 +583,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -563,6 +592,7 @@
             _Py_UopsSymbol *res;
             retval = stack_pointer[-1];
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             ctx->frame->stack_pointer = stack_pointer;
             frame_pop(ctx);
             stack_pointer = ctx->frame->stack_pointer;
@@ -581,6 +611,7 @@
             }
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -600,6 +631,7 @@
             awaitable = sym_new_not_null(ctx);
             stack_pointer[0] = awaitable;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -625,6 +657,7 @@
 
         case _POP_EXCEPT: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -633,6 +666,7 @@
             value = sym_new_not_null(ctx);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -641,11 +675,13 @@
             bc = sym_new_not_null(ctx);
             stack_pointer[0] = bc;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _STORE_NAME: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -664,6 +700,7 @@
                 values[i] = sym_new_unknown(ctx);
             }
             stack_pointer += -1 + oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -675,6 +712,7 @@
             stack_pointer[-1] = val1;
             stack_pointer[0] = val0;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -685,6 +723,7 @@
                 values[_i] = sym_new_not_null(ctx);
             }
             stack_pointer += -1 + oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -695,6 +734,7 @@
                 values[_i] = sym_new_not_null(ctx);
             }
             stack_pointer += -1 + oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -710,21 +750,25 @@
                 values[i] = sym_new_unknown(ctx);
             }
             stack_pointer += (oparg >> 8) + (oparg & 0xFF);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _STORE_ATTR: {
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _DELETE_ATTR: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _STORE_GLOBAL: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -737,6 +781,7 @@
             locals = sym_new_not_null(ctx);
             stack_pointer[0] = locals;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -752,6 +797,7 @@
             stack_pointer[0] = res;
             if (oparg & 1) stack_pointer[1] = null;
             stack_pointer += 1 + (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -771,6 +817,7 @@
             stack_pointer[0] = res;
             if (oparg & 1) stack_pointer[1] = null;
             stack_pointer += 1 + (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -782,6 +829,7 @@
             stack_pointer[0] = res;
             if (oparg & 1) stack_pointer[1] = null;
             stack_pointer += 1 + (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -809,11 +857,13 @@
             value = sym_new_not_null(ctx);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _STORE_DEREF: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -826,6 +876,7 @@
             str = sym_new_not_null(ctx);
             stack_pointer[-oparg] = str;
             stack_pointer += 1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -834,6 +885,7 @@
             tup = sym_new_not_null(ctx);
             stack_pointer[-oparg] = tup;
             stack_pointer += 1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -842,16 +894,19 @@
             list = sym_new_not_null(ctx);
             stack_pointer[-oparg] = list;
             stack_pointer += 1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _LIST_EXTEND: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _SET_UPDATE: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -862,6 +917,7 @@
             map = sym_new_not_null(ctx);
             stack_pointer[-oparg*2] = map;
             stack_pointer += 1 - oparg*2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -874,21 +930,25 @@
             map = sym_new_not_null(ctx);
             stack_pointer[-1 - oparg] = map;
             stack_pointer += -oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _DICT_UPDATE: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _DICT_MERGE: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _MAP_ADD: {
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -899,6 +959,7 @@
             attr = sym_new_not_null(ctx);
             stack_pointer[-3] = attr;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -910,6 +971,7 @@
             stack_pointer[-3] = attr;
             stack_pointer[-2] = self_or_null;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -926,6 +988,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = self_or_null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -972,6 +1035,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1024,6 +1088,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1044,6 +1109,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1060,6 +1126,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1080,6 +1147,7 @@
             stack_pointer[-1] = attr;
             if (oparg & 1) stack_pointer[0] = null;
             stack_pointer += (oparg & 1);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1093,16 +1161,19 @@
 
         case _STORE_ATTR_INSTANCE_VALUE: {
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _STORE_ATTR_WITH_HINT: {
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
         case _STORE_ATTR_SLOT: {
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1122,6 +1193,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1136,6 +1208,7 @@
             res = sym_new_type(ctx, &PyBool_Type);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1150,6 +1223,7 @@
             res = sym_new_type(ctx, &PyBool_Type);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1164,6 +1238,7 @@
             res = sym_new_type(ctx, &PyBool_Type);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1178,6 +1253,7 @@
             res = sym_new_type(ctx, &PyBool_Type);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1192,6 +1268,7 @@
             res = sym_new_type(ctx, &PyBool_Type);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1200,6 +1277,7 @@
             b = sym_new_not_null(ctx);
             stack_pointer[-2] = b;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1208,6 +1286,7 @@
             b = sym_new_not_null(ctx);
             stack_pointer[-2] = b;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1244,6 +1323,7 @@
             len_o = sym_new_not_null(ctx);
             stack_pointer[0] = len_o;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1252,6 +1332,7 @@
             attrs = sym_new_not_null(ctx);
             stack_pointer[-3] = attrs;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1260,6 +1341,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1268,6 +1350,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1276,6 +1359,7 @@
             values_or_none = sym_new_not_null(ctx);
             stack_pointer[0] = values_or_none;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1300,6 +1384,7 @@
             next = sym_new_not_null(ctx);
             stack_pointer[0] = next;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1320,6 +1405,7 @@
             next = sym_new_not_null(ctx);
             stack_pointer[0] = next;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1338,6 +1424,7 @@
             next = sym_new_not_null(ctx);
             stack_pointer[0] = next;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1359,6 +1446,7 @@
             (void)iter;
             stack_pointer[0] = next;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1379,6 +1467,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self_or_null;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1387,6 +1476,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1398,6 +1488,7 @@
             stack_pointer[-1] = prev_exc;
             stack_pointer[0] = new_exc;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1421,6 +1512,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1436,6 +1528,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1469,6 +1562,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1496,6 +1590,7 @@
             ctx->done = true;
             stack_pointer[-2 - oparg] = (_Py_UopsSymbol *)new_frame;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1526,6 +1621,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1621,6 +1717,7 @@
             }
             stack_pointer[-2 - oparg] = (_Py_UopsSymbol *)new_frame;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1628,6 +1725,7 @@
             _Py_UOpsAbstractFrame *new_frame;
             new_frame = (_Py_UOpsAbstractFrame *)stack_pointer[-1];
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             ctx->frame->stack_pointer = stack_pointer;
             ctx->frame = new_frame;
             ctx->curr_frame_depth++;
@@ -1664,6 +1762,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1672,6 +1771,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1680,6 +1780,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-3] = res;
             stack_pointer += -2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1687,6 +1788,7 @@
 
         case _EXIT_INIT_CHECK: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1695,6 +1797,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1703,6 +1806,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1711,6 +1815,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1719,6 +1824,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1727,6 +1833,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1735,6 +1842,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1743,6 +1851,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1751,6 +1860,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1759,6 +1869,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1767,6 +1878,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1790,6 +1902,7 @@
             func = sym_new_not_null(ctx);
             stack_pointer[-2] = func;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1813,6 +1926,7 @@
             }
             stack_pointer[0] = res;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1821,6 +1935,7 @@
             slice = sym_new_not_null(ctx);
             stack_pointer[-2 - ((oparg == 3) ? 1 : 0)] = slice;
             stack_pointer += -1 - ((oparg == 3) ? 1 : 0);
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1843,6 +1958,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1854,6 +1970,7 @@
             top = bottom;
             stack_pointer[0] = top;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1881,6 +1998,7 @@
             res = sym_new_unknown(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1917,6 +2035,7 @@
                 eliminate_pop_guard(this_instr, value != Py_True);
             }
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1929,6 +2048,7 @@
                 eliminate_pop_guard(this_instr, value != Py_False);
             }
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1945,6 +2065,7 @@
                 eliminate_pop_guard(this_instr, true);
             }
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -1961,6 +2082,7 @@
                 eliminate_pop_guard(this_instr, false);
             }
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2001,6 +2123,7 @@
             value = sym_new_const(ctx, ptr);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2010,6 +2133,7 @@
             value = sym_new_const(ctx, ptr);
             stack_pointer[0] = value;
             stack_pointer += 1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2029,6 +2153,7 @@
             stack_pointer[0] = value;
             stack_pointer[1] = null;
             stack_pointer += 2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2041,6 +2166,7 @@
             stack_pointer[0] = value;
             stack_pointer[1] = null;
             stack_pointer += 2;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2050,6 +2176,7 @@
 
         case _INTERNAL_INCREMENT_OPT_COUNTER: {
             stack_pointer += -1;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
@@ -2079,6 +2206,7 @@
 
         case _ERROR_POP_N: {
             stack_pointer += -oparg;
+            assert(WITHIN_STACK_BOUNDS());
             break;
         }
 
diff --git a/Tools/cases_generator/stack.py b/Tools/cases_generator/stack.py
index 7f07a68..7325f2f 100644
--- a/Tools/cases_generator/stack.py
+++ b/Tools/cases_generator/stack.py
@@ -199,6 +199,7 @@ class Stack:
         number = self.base_offset.to_c()
         if number != "0":
             out.emit(f"stack_pointer += {number};\n")
+            out.emit("assert(WITHIN_STACK_BOUNDS());\n")
         self.variables = []
         self.base_offset.clear()
         self.top_offset.clear()
diff --git a/Tools/jit/template.c b/Tools/jit/template.c
index 813e586..39ce236 100644
--- a/Tools/jit/template.c
+++ b/Tools/jit/template.c
@@ -80,6 +80,9 @@ do {                                                         \
 #undef JUMP_TO_ERROR
 #define JUMP_TO_ERROR() PATCH_JUMP(_JIT_ERROR_TARGET)
 
+#undef WITHIN_STACK_BOUNDS
+#define WITHIN_STACK_BOUNDS() 1
+
 _Py_CODEUNIT *
 _JIT_ENTRY(_PyInterpreterFrame *frame, PyObject **stack_pointer, PyThreadState *tstate)
 {