From 07604150db8403abb19c9a14c94614ba81b6094f Mon Sep 17 00:00:00 2001
From: Ken Jin <kenjin4096@gmail.com>
Date: Tue, 2 Dec 2025 21:10:11 +0000
Subject: [PATCH 1/8] Check stack bounds in JIT optimizer

---
 Lib/test/test_generated_cases.py             |   8 +-
 Python/optimizer_analysis.c                  |  11 +-
 Python/optimizer_cases.c.h                   | 346 +++++++++----------
 Tools/cases_generator/optimizer_generator.py |  24 +-
 Tools/cases_generator/stack.py               |  15 +-
 5 files changed, 213 insertions(+), 191 deletions(-)

diff --git a/Lib/test/test_generated_cases.py b/Lib/test/test_generated_cases.py
index 09ce329bdcd14d..b51c8bd07cd2a4 100644
--- a/Lib/test/test_generated_cases.py
+++ b/Lib/test/test_generated_cases.py
@@ -2116,7 +2116,7 @@ def test_validate_uop_unused_input(self):
         output = """
         case OP: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
         """
@@ -2133,7 +2133,7 @@ def test_validate_uop_unused_input(self):
         output = """
         case OP: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
         """
@@ -2155,7 +2155,7 @@ def test_validate_uop_unused_output(self):
             foo = NULL;
             stack_pointer[0] = foo;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
         """
@@ -2173,7 +2173,7 @@ def test_validate_uop_unused_output(self):
         output = """
         case OP: {
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
         """
diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index 8d7b734e17cb0b..84a847a4ae4eb0 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -144,10 +144,6 @@ incorrect_keys(PyObject *obj, uint32_t version)
 
 #define CURRENT_FRAME_IS_INIT_SHIM() (ctx->frame->code == ((PyCodeObject *)&_Py_InitCleanup))
 
-#define WITHIN_STACK_BOUNDS() \
-    (CURRENT_FRAME_IS_INIT_SHIM() || (STACK_LEVEL() >= 0 && STACK_LEVEL() <= STACK_SIZE()))
-
-
 #define GETLOCAL(idx)          ((ctx->frame->locals[idx]))
 
 #define REPLACE_OP(INST, OP, ARG, OPERAND)    \
@@ -191,6 +187,13 @@ incorrect_keys(PyObject *obj, uint32_t version)
 #define sym_new_truthiness _Py_uop_sym_new_truthiness
 
 #define JUMP_TO_LABEL(label) goto label;
+#define CHECK_STACK_BOUNDS() do { \
+    if (!CURRENT_FRAME_IS_INIT_SHIM() && (STACK_LEVEL() < 0 || STACK_LEVEL() > STACK_SIZE())) { \
+        ctx->contradiction = true; \
+        ctx->done = true; \
+        break; \
+    } \
+} while (0);
 
 static int
 optimize_to_bool(
diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h
index 9ebd113df2dabf..98c094ac15b0fd 100644
--- a/Python/optimizer_cases.c.h
+++ b/Python/optimizer_cases.c.h
@@ -35,7 +35,7 @@
             }
             stack_pointer[0] = value;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -44,7 +44,7 @@
             value = GETLOCAL(oparg);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -53,7 +53,7 @@
             value = PyJitRef_Borrow(GETLOCAL(oparg));
             stack_pointer[0] = value;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -64,7 +64,7 @@
             GETLOCAL(oparg) = temp;
             stack_pointer[0] = value;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -76,7 +76,7 @@
             value = PyJitRef_Borrow(sym_new_const(ctx, val));
             stack_pointer[0] = value;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -89,7 +89,7 @@
             value = PyJitRef_Borrow(sym_new_const(ctx, val));
             stack_pointer[0] = value;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -98,7 +98,7 @@
             value = stack_pointer[-1];
             GETLOCAL(oparg) = value;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -121,37 +121,37 @@
                 REPLACE_OP(this_instr, _POP_TOP_UNICODE, 0, 0);
             }
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _POP_TOP_NOP: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _POP_TOP_INT: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _POP_TOP_FLOAT: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _POP_TOP_UNICODE: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _POP_TWO: {
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -160,19 +160,19 @@
             res = sym_new_null(ctx);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _END_FOR: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _POP_ITER: {
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -181,7 +181,7 @@
             val = sym_new_not_null(ctx);
             stack_pointer[-2] = val;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -506,13 +506,13 @@
                 }
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             res = sym_new_compact_int(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -556,13 +556,13 @@
                 }
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             res = sym_new_compact_int(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -606,13 +606,13 @@
                 }
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             res = sym_new_compact_int(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -675,7 +675,7 @@
                 }
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             res = sym_new_type(ctx, &PyFloat_Type);
@@ -684,7 +684,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -727,7 +727,7 @@
                 }
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             res = sym_new_type(ctx, &PyFloat_Type);
@@ -736,7 +736,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -779,7 +779,7 @@
                 }
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             res = sym_new_type(ctx, &PyFloat_Type);
@@ -788,7 +788,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -797,7 +797,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -806,7 +806,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -815,7 +815,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -858,13 +858,13 @@
                 }
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             res = sym_new_type(ctx, &PyUnicode_Type);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -889,7 +889,7 @@
             }
             GETLOCAL(this_instr->operand0) = res;
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -902,7 +902,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -922,13 +922,13 @@
             }
             stack_pointer[-3] = res;
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _STORE_SLICE: {
             stack_pointer += -4;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -937,7 +937,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -946,7 +946,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -955,7 +955,7 @@
             res = sym_new_type(ctx, &PyUnicode_Type);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1004,7 +1004,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1033,7 +1033,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1042,7 +1042,7 @@
             getitem = sym_new_not_null(ctx);
             stack_pointer[0] = getitem;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1052,43 +1052,43 @@
             ctx->done = true;
             stack_pointer[-3] = new_frame;
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _LIST_APPEND: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _SET_ADD: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _STORE_SUBSCR: {
             stack_pointer += -3;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _STORE_SUBSCR_LIST_INT: {
             stack_pointer += -3;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _STORE_SUBSCR_DICT: {
             stack_pointer += -3;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _DELETE_SUBSCR: {
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1104,7 +1104,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1114,7 +1114,7 @@
             retval = stack_pointer[-1];
             JitOptRef temp = PyJitRef_StripReferenceInfo(retval);
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             ctx->frame->stack_pointer = stack_pointer;
             PyCodeObject *returning_code = get_code_with_logging(this_instr);
             if (returning_code == NULL) {
@@ -1136,7 +1136,7 @@
             res = temp;
             stack_pointer[0] = res;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1152,7 +1152,7 @@
             awaitable = sym_new_not_null(ctx);
             stack_pointer[0] = awaitable;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1179,7 +1179,7 @@
             retval = stack_pointer[-1];
             JitOptRef temp = PyJitRef_StripReferenceInfo(retval);
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             ctx->frame->stack_pointer = stack_pointer;
             PyCodeObject *returning_code = get_code_with_logging(this_instr);
             if (returning_code == NULL) {
@@ -1195,13 +1195,13 @@
             value = temp;
             stack_pointer[0] = value;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _POP_EXCEPT: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1210,7 +1210,7 @@
             value = sym_new_not_null(ctx);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1219,13 +1219,13 @@
             bc = sym_new_not_null(ctx);
             stack_pointer[0] = bc;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _STORE_NAME: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1243,7 +1243,7 @@
                 values[i] = sym_new_unknown(ctx);
             }
             stack_pointer += -1 + oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1257,7 +1257,7 @@
             stack_pointer[-1] = val1;
             stack_pointer[0] = val0;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1270,7 +1270,7 @@
                 values[i] = sym_tuple_getitem(ctx, seq, oparg - i - 1);
             }
             stack_pointer += -1 + oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1281,7 +1281,7 @@
                 values[_i] = sym_new_not_null(ctx);
             }
             stack_pointer += -1 + oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1296,25 +1296,25 @@
                 values[i] = sym_new_unknown(ctx);
             }
             stack_pointer += (oparg & 0xFF) + (oparg >> 8);
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _STORE_ATTR: {
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _DELETE_ATTR: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _STORE_GLOBAL: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1327,7 +1327,7 @@
             locals = sym_new_not_null(ctx);
             stack_pointer[0] = locals;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1338,7 +1338,7 @@
             v = sym_new_not_null(ctx);
             stack_pointer[0] = v;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1347,7 +1347,7 @@
             res = &stack_pointer[0];
             res[0] = sym_new_not_null(ctx);
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1362,7 +1362,7 @@
                 REPLACE_OP(this_instr, _NOP, 0, 0);
             }
             stack_pointer += (oparg & 1);
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1428,7 +1428,7 @@
             }
             stack_pointer[0] = res;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1464,7 +1464,7 @@
             }
             stack_pointer[0] = res;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1492,13 +1492,13 @@
             value = sym_new_not_null(ctx);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _STORE_DEREF: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1511,7 +1511,7 @@
             str = sym_new_type(ctx, &PyUnicode_Type);
             stack_pointer[-oparg] = str;
             stack_pointer += 1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1520,7 +1520,7 @@
             interpolation = sym_new_not_null(ctx);
             stack_pointer[-2 - (oparg & 1)] = interpolation;
             stack_pointer += -1 - (oparg & 1);
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1529,7 +1529,7 @@
             template = sym_new_not_null(ctx);
             stack_pointer[-2] = template;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1540,7 +1540,7 @@
             tup = sym_new_tuple(ctx, oparg, values);
             stack_pointer[-oparg] = tup;
             stack_pointer += 1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1549,19 +1549,19 @@
             list = sym_new_type(ctx, &PyList_Type);
             stack_pointer[-oparg] = list;
             stack_pointer += 1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _LIST_EXTEND: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _SET_UPDATE: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1570,7 +1570,7 @@
             set = sym_new_type(ctx, &PySet_Type);
             stack_pointer[-oparg] = set;
             stack_pointer += 1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1579,7 +1579,7 @@
             map = sym_new_type(ctx, &PyDict_Type);
             stack_pointer[-oparg*2] = map;
             stack_pointer += 1 - oparg*2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1589,19 +1589,19 @@
 
         case _DICT_UPDATE: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _DICT_MERGE: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _MAP_ADD: {
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1610,7 +1610,7 @@
             attr_st = sym_new_not_null(ctx);
             stack_pointer[-3] = attr_st;
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1622,7 +1622,7 @@
             stack_pointer[-3] = attr;
             stack_pointer[-2] = self_or_null;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1639,7 +1639,7 @@
                 self_or_null[0] = sym_new_unknown(ctx);
             }
             stack_pointer += (oparg&1);
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1781,19 +1781,19 @@
 
         case _STORE_ATTR_INSTANCE_VALUE: {
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _STORE_ATTR_WITH_HINT: {
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _STORE_ATTR_SLOT: {
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1842,7 +1842,7 @@
                 }
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             if (oparg & 16) {
@@ -1853,7 +1853,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1893,13 +1893,13 @@
                 }
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             res = sym_new_type(ctx, &PyBool_Type);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1943,13 +1943,13 @@
                 }
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             res = sym_new_type(ctx, &PyBool_Type);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -1991,13 +1991,13 @@
                 }
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             res = sym_new_type(ctx, &PyBool_Type);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2006,7 +2006,7 @@
             b = sym_new_type(ctx, &PyBool_Type);
             stack_pointer[-2] = b;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2044,13 +2044,13 @@
                 }
                 stack_pointer[-2] = b;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             b = sym_new_type(ctx, &PyBool_Type);
             stack_pointer[-2] = b;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2070,7 +2070,7 @@
             b = sym_new_type(ctx, &PyBool_Type);
             stack_pointer[-2] = b;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2079,7 +2079,7 @@
             b = sym_new_type(ctx, &PyBool_Type);
             stack_pointer[-2] = b;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2105,7 +2105,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2114,7 +2114,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2151,13 +2151,13 @@
                 len = sym_new_const(ctx, temp);
                 stack_pointer[0] = len;
                 stack_pointer += 1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 Py_DECREF(temp);
                 stack_pointer += -1;
             }
             stack_pointer[0] = len;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2166,7 +2166,7 @@
             attrs = sym_new_not_null(ctx);
             stack_pointer[-3] = attrs;
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2175,7 +2175,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2184,7 +2184,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2193,7 +2193,7 @@
             values_or_none = sym_new_not_null(ctx);
             stack_pointer[0] = values_or_none;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2213,7 +2213,7 @@
             stack_pointer[-1] = iter;
             stack_pointer[0] = index_or_null;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2231,7 +2231,7 @@
             next = sym_new_not_null(ctx);
             stack_pointer[0] = next;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2254,7 +2254,7 @@
             next = sym_new_not_null(ctx);
             stack_pointer[0] = next;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2279,7 +2279,7 @@
             next = sym_new_not_null(ctx);
             stack_pointer[0] = next;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2298,7 +2298,7 @@
             next = sym_new_type(ctx, &PyLong_Type);
             stack_pointer[0] = next;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2308,7 +2308,7 @@
             ctx->done = true;
             stack_pointer[0] = gen_frame;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2320,7 +2320,7 @@
             method_and_self[0] = sym_new_null(ctx);
             method_and_self[1] = self;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2337,7 +2337,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2349,7 +2349,7 @@
             stack_pointer[-1] = prev_exc;
             stack_pointer[0] = new_exc;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2377,7 +2377,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2397,7 +2397,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2451,7 +2451,7 @@
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2485,7 +2485,7 @@
             new_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, NULL, 0));
             stack_pointer[-2 - oparg] = new_frame;
             stack_pointer += -1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2533,7 +2533,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2618,7 +2618,7 @@
             }
             stack_pointer[-2 - oparg] = new_frame;
             stack_pointer += -1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2626,7 +2626,7 @@
             JitOptRef new_frame;
             new_frame = stack_pointer[-1];
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             if (!CURRENT_FRAME_IS_INIT_SHIM()) {
                 ctx->frame->stack_pointer = stack_pointer;
             }
@@ -2705,7 +2705,7 @@
             }
             stack_pointer[-3] = res;
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2731,7 +2731,7 @@
             }
             stack_pointer[-3] = res;
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2757,7 +2757,7 @@
             }
             stack_pointer[-3] = res;
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2799,13 +2799,13 @@
             init_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, args-1, oparg+1));
             stack_pointer[-2 - oparg] = init_frame;
             stack_pointer += -1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _EXIT_INIT_CHECK: {
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2814,7 +2814,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2823,7 +2823,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2832,7 +2832,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2841,7 +2841,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2874,13 +2874,13 @@
                 res = sym_new_const(ctx, temp);
                 stack_pointer[-3] = res;
                 stack_pointer += -2;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 Py_DECREF(temp);
                 stack_pointer += 2;
             }
             stack_pointer[-3] = res;
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2914,7 +2914,7 @@
             }
             stack_pointer[-4] = res;
             stack_pointer += -3;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2931,7 +2931,7 @@
 
         case _CALL_LIST_APPEND: {
             stack_pointer += -3;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2940,7 +2940,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2949,7 +2949,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2958,7 +2958,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2967,7 +2967,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -2990,7 +2990,7 @@
             new_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, NULL, 0));
             stack_pointer[-3 - oparg] = new_frame;
             stack_pointer += -2 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3015,7 +3015,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-3 - oparg] = res;
             stack_pointer += -2 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3037,7 +3037,7 @@
             func_out = sym_new_not_null(ctx);
             stack_pointer[-2] = func_out;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3058,7 +3058,7 @@
             res = sym_new_unknown(ctx);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3067,7 +3067,7 @@
             slice = sym_new_type(ctx, &PySlice_Type);
             stack_pointer[-oparg] = slice;
             stack_pointer += 1 - oparg;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3090,7 +3090,7 @@
             res = sym_new_not_null(ctx);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3102,7 +3102,7 @@
             top = bottom;
             stack_pointer[0] = top;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3141,7 +3141,7 @@
                 }
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                assert(WITHIN_STACK_BOUNDS());
+                CHECK_STACK_BOUNDS();
                 break;
             }
             bool lhs_int = sym_matches_type(lhs, &PyLong_Type);
@@ -3179,7 +3179,7 @@
             }
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3225,7 +3225,7 @@
             }
             sym_set_const(flag, Py_True);
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3239,7 +3239,7 @@
             }
             sym_set_const(flag, Py_False);
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3257,7 +3257,7 @@
             }
             sym_set_const(val, Py_None);
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3274,7 +3274,7 @@
                 eliminate_pop_guard(this_instr, false);
             }
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3319,7 +3319,7 @@
             value = sym_new_const(ctx, ptr);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3337,25 +3337,25 @@
             value = PyJitRef_Borrow(sym_new_const(ctx, ptr));
             stack_pointer[0] = value;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _POP_CALL: {
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _POP_CALL_ONE: {
             stack_pointer += -3;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
         case _POP_CALL_TWO: {
             stack_pointer += -4;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3372,7 +3372,7 @@
             value = sym_new_not_null(ctx);
             stack_pointer[-2] = value;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3382,7 +3382,7 @@
             value = PyJitRef_Borrow(sym_new_const(ctx, ptr));
             stack_pointer[-2] = value;
             stack_pointer += -1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3392,7 +3392,7 @@
             value = PyJitRef_Borrow(sym_new_const(ctx, ptr));
             stack_pointer[-3] = value;
             stack_pointer += -2;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3402,7 +3402,7 @@
             value = PyJitRef_Borrow(sym_new_const(ctx, ptr));
             stack_pointer[-4] = value;
             stack_pointer += -3;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3414,7 +3414,7 @@
             stack_pointer[-1] = value;
             stack_pointer[0] = new;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
@@ -3426,7 +3426,7 @@
             stack_pointer[-1] = value;
             stack_pointer[0] = new;
             stack_pointer += 1;
-            assert(WITHIN_STACK_BOUNDS());
+            CHECK_STACK_BOUNDS();
             break;
         }
 
diff --git a/Tools/cases_generator/optimizer_generator.py b/Tools/cases_generator/optimizer_generator.py
index 41df073cf6df23..ea3dff69c663ba 100644
--- a/Tools/cases_generator/optimizer_generator.py
+++ b/Tools/cases_generator/optimizer_generator.py
@@ -148,7 +148,23 @@ def __init__(self, out: CWriter, labels: dict[str, Label], original_uop: Uop, st
         self.stack = stack
 
     def emit_save(self, storage: Storage) -> None:
-        storage.flush(self.out)
+        storage.flush(self.out, check_stack_bounds=True)
+
+    def sync_sp(
+        self,
+        tkn: Token,
+        tkn_iter: TokenIterator,
+        uop: CodeSection,
+        storage: Storage,
+        inst: Instruction | None,
+    ) -> bool:
+        next(tkn_iter)
+        next(tkn_iter)
+        next(tkn_iter)
+        storage.clear_inputs("when syncing stack")
+        storage.flush(self.out, check_stack_bounds=True)
+        storage.stack.clear(self.out)
+        return True
 
     def emit_reload(self, storage: Storage) -> None:
         pass
@@ -256,7 +272,7 @@ def replace_opcode_if_evaluates_pure(
                         emitter.emit("}\n")
                         emitter.emit("}\n")
 
-        storage.flush(self.out)
+        storage.flush(self.out, check_stack_bounds=True)
         emitter.emit("break;\n")
         emitter.emit("}\n")
         return True
@@ -397,12 +413,12 @@ def write_uop(
                 var.in_local = False
             _, storage = emitter.emit_tokens(override, storage, None, False)
             out.start_line()
-            storage.flush(out)
+            storage.flush(out, check_stack_bounds=True)
             out.start_line()
         else:
             emit_default(out, uop, stack)
             out.start_line()
-            stack.flush(out)
+            stack.flush(out, check_stack_bounds=True)
     except StackError as ex:
         raise analysis_error(ex.args[0], prototype.body.open) # from None
 
diff --git a/Tools/cases_generator/stack.py b/Tools/cases_generator/stack.py
index 3a0e7e5d0d5636..8e74538f218069 100644
--- a/Tools/cases_generator/stack.py
+++ b/Tools/cases_generator/stack.py
@@ -291,12 +291,15 @@ def _do_emit(
     ) -> None:
         out.emit(f"stack_pointer[{stack_offset.to_c()}] = {var.name};\n")
 
-    def _save_physical_sp(self, out: CWriter) -> None:
+    def _save_physical_sp(self, out: CWriter, check_stack_bounds: bool) -> None:
         if self.physical_sp != self.logical_sp:
             diff = self.logical_sp - self.physical_sp
             out.start_line()
             out.emit(f"stack_pointer += {diff.to_c()};\n")
-            out.emit(f"assert(WITHIN_STACK_BOUNDS());\n")
+            if check_stack_bounds:
+                out.emit("CHECK_STACK_BOUNDS();\n")
+            else:
+                out.emit(f"assert(WITHIN_STACK_BOUNDS());\n")
             self.physical_sp = self.logical_sp
             self._print(out)
 
@@ -316,10 +319,10 @@ def save_variables(self, out: CWriter) -> None:
                 self._print(out)
             var_offset = var_offset.push(var.item)
 
-    def flush(self, out: CWriter) -> None:
+    def flush(self, out: CWriter, check_stack_bounds: bool = False) -> None:
         self._print(out)
         self.save_variables(out)
-        self._save_physical_sp(out)
+        self._save_physical_sp(out, check_stack_bounds)
         out.start_line()
 
     def is_flushed(self) -> bool:
@@ -498,10 +501,10 @@ def locals_cached(self) -> bool:
                 return True
         return False
 
-    def flush(self, out: CWriter) -> None:
+    def flush(self, out: CWriter, check_stack_bounds: bool = False) -> None:
         self.clear_dead_inputs()
         self._push_defined_outputs()
-        self.stack.flush(out)
+        self.stack.flush(out, check_stack_bounds=check_stack_bounds)
 
     def save(self, out: CWriter) -> None:
         assert self.spilled >= 0

From 3c22cb5456574ea3d7b8dc70b8321a9f07a5d8c5 Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Tue, 2 Dec 2025 21:11:54 +0000
Subject: [PATCH 2/8] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?=
 =?UTF-8?q?rb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../2025-12-02-21-11-46.gh-issue-141976.yu7pDV.rst               | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2025-12-02-21-11-46.gh-issue-141976.yu7pDV.rst

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-12-02-21-11-46.gh-issue-141976.yu7pDV.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-12-02-21-11-46.gh-issue-141976.yu7pDV.rst
new file mode 100644
index 00000000000000..f77315b7c37d80
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-12-02-21-11-46.gh-issue-141976.yu7pDV.rst
@@ -0,0 +1 @@
+Check against abstract stack overflow in the JIT optimizer.

From 63f6fc04b41dd8563d6f05d3eb13b3711d91276a Mon Sep 17 00:00:00 2001
From: Ken Jin <kenjin4096@gmail.com>
Date: Wed, 3 Dec 2025 19:27:33 +0000
Subject: [PATCH 3/8] apply review suggestions

---
 Python/optimizer_analysis.c                  |  3 ++-
 Tools/cases_generator/optimizer_generator.py | 12 ++++++------
 Tools/cases_generator/stack.py               | 16 +++++++++-------
 3 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index 84a847a4ae4eb0..2427360b5718ef 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -187,7 +187,8 @@ incorrect_keys(PyObject *obj, uint32_t version)
 #define sym_new_truthiness _Py_uop_sym_new_truthiness
 
 #define JUMP_TO_LABEL(label) goto label;
-#define CHECK_STACK_BOUNDS() do { \
+#define CHECK_STACK_BOUNDS() \
+do { \
     if (!CURRENT_FRAME_IS_INIT_SHIM() && (STACK_LEVEL() < 0 || STACK_LEVEL() > STACK_SIZE())) { \
         ctx->contradiction = true; \
         ctx->done = true; \
diff --git a/Tools/cases_generator/optimizer_generator.py b/Tools/cases_generator/optimizer_generator.py
index ea3dff69c663ba..c008679a9354b7 100644
--- a/Tools/cases_generator/optimizer_generator.py
+++ b/Tools/cases_generator/optimizer_generator.py
@@ -148,7 +148,7 @@ def __init__(self, out: CWriter, labels: dict[str, Label], original_uop: Uop, st
         self.stack = stack
 
     def emit_save(self, storage: Storage) -> None:
-        storage.flush(self.out, check_stack_bounds=True)
+        storage.flush(self.out)
 
     def sync_sp(
         self,
@@ -162,7 +162,7 @@ def sync_sp(
         next(tkn_iter)
         next(tkn_iter)
         storage.clear_inputs("when syncing stack")
-        storage.flush(self.out, check_stack_bounds=True)
+        storage.flush(self.out)
         storage.stack.clear(self.out)
         return True
 
@@ -272,7 +272,7 @@ def replace_opcode_if_evaluates_pure(
                         emitter.emit("}\n")
                         emitter.emit("}\n")
 
-        storage.flush(self.out, check_stack_bounds=True)
+        storage.flush(self.out)
         emitter.emit("break;\n")
         emitter.emit("}\n")
         return True
@@ -413,12 +413,12 @@ def write_uop(
                 var.in_local = False
             _, storage = emitter.emit_tokens(override, storage, None, False)
             out.start_line()
-            storage.flush(out, check_stack_bounds=True)
+            storage.flush(out)
             out.start_line()
         else:
             emit_default(out, uop, stack)
             out.start_line()
-            stack.flush(out, check_stack_bounds=True)
+            stack.flush(out)
     except StackError as ex:
         raise analysis_error(ex.args[0], prototype.body.open) # from None
 
@@ -461,7 +461,7 @@ def generate_abstract_interpreter(
             declare_variables(override, out, skip_inputs=False)
         else:
             declare_variables(uop, out, skip_inputs=True)
-        stack = Stack()
+        stack = Stack(check_stack_bounds=True)
         write_uop(override, uop, out, stack, debug, skip_inputs=(override is None))
         out.start_line()
         out.emit("break;\n")
diff --git a/Tools/cases_generator/stack.py b/Tools/cases_generator/stack.py
index 8e74538f218069..9febe800efbe5e 100644
--- a/Tools/cases_generator/stack.py
+++ b/Tools/cases_generator/stack.py
@@ -216,11 +216,12 @@ def array_or_scalar(var: StackItem | Local) -> str:
     return "array" if var.is_array() else "scalar"
 
 class Stack:
-    def __init__(self) -> None:
+    def __init__(self, check_stack_bounds: bool = False) -> None:
         self.base_offset = PointerOffset.zero()
         self.physical_sp = PointerOffset.zero()
         self.logical_sp = PointerOffset.zero()
         self.variables: list[Local] = []
+        self.check_stack_bounds = check_stack_bounds
 
     def drop(self, var: StackItem, check_liveness: bool) -> None:
         self.logical_sp = self.logical_sp.pop(var)
@@ -291,12 +292,12 @@ def _do_emit(
     ) -> None:
         out.emit(f"stack_pointer[{stack_offset.to_c()}] = {var.name};\n")
 
-    def _save_physical_sp(self, out: CWriter, check_stack_bounds: bool) -> None:
+    def _save_physical_sp(self, out: CWriter) -> None:
         if self.physical_sp != self.logical_sp:
             diff = self.logical_sp - self.physical_sp
             out.start_line()
             out.emit(f"stack_pointer += {diff.to_c()};\n")
-            if check_stack_bounds:
+            if self.check_stack_bounds:
                 out.emit("CHECK_STACK_BOUNDS();\n")
             else:
                 out.emit(f"assert(WITHIN_STACK_BOUNDS());\n")
@@ -319,10 +320,10 @@ def save_variables(self, out: CWriter) -> None:
                 self._print(out)
             var_offset = var_offset.push(var.item)
 
-    def flush(self, out: CWriter, check_stack_bounds: bool = False) -> None:
+    def flush(self, out: CWriter) -> None:
         self._print(out)
         self.save_variables(out)
-        self._save_physical_sp(out, check_stack_bounds)
+        self._save_physical_sp(out)
         out.start_line()
 
     def is_flushed(self) -> bool:
@@ -350,6 +351,7 @@ def copy(self) -> "Stack":
         other.physical_sp = self.physical_sp
         other.logical_sp = self.logical_sp
         other.variables = [var.copy() for var in self.variables]
+        other.check_stack_bounds = self.check_stack_bounds
         return other
 
     def __eq__(self, other: object) -> bool:
@@ -501,10 +503,10 @@ def locals_cached(self) -> bool:
                 return True
         return False
 
-    def flush(self, out: CWriter, check_stack_bounds: bool = False) -> None:
+    def flush(self, out: CWriter) -> None:
         self.clear_dead_inputs()
         self._push_defined_outputs()
-        self.stack.flush(out, check_stack_bounds=check_stack_bounds)
+        self.stack.flush(out)
 
     def save(self, out: CWriter) -> None:
         assert self.spilled >= 0

From 08d6c79bee21424820040a0786df93c7ddacc52a Mon Sep 17 00:00:00 2001
From: Ken Jin <kenjin4096@gmail.com>
Date: Thu, 4 Dec 2025 12:51:00 +0000
Subject: [PATCH 4/8] address review

---
 Tools/cases_generator/optimizer_generator.py | 16 ----------------
 1 file changed, 16 deletions(-)

diff --git a/Tools/cases_generator/optimizer_generator.py b/Tools/cases_generator/optimizer_generator.py
index c008679a9354b7..ab0a90e234b124 100644
--- a/Tools/cases_generator/optimizer_generator.py
+++ b/Tools/cases_generator/optimizer_generator.py
@@ -150,22 +150,6 @@ def __init__(self, out: CWriter, labels: dict[str, Label], original_uop: Uop, st
     def emit_save(self, storage: Storage) -> None:
         storage.flush(self.out)
 
-    def sync_sp(
-        self,
-        tkn: Token,
-        tkn_iter: TokenIterator,
-        uop: CodeSection,
-        storage: Storage,
-        inst: Instruction | None,
-    ) -> bool:
-        next(tkn_iter)
-        next(tkn_iter)
-        next(tkn_iter)
-        storage.clear_inputs("when syncing stack")
-        storage.flush(self.out)
-        storage.stack.clear(self.out)
-        return True
-
     def emit_reload(self, storage: Storage) -> None:
         pass
 

From ac6c21ac952d2ca82588e38882759d6f83f10cee Mon Sep 17 00:00:00 2001
From: Ken Jin <kenjin4096@gmail.com>
Date: Thu, 4 Dec 2025 13:15:49 +0000
Subject: [PATCH 5/8] check before not after

---
 Python/optimizer_analysis.c    |   5 +-
 Python/optimizer_cases.c.h     | 523 ++++++++++++++++++++++-----------
 Tools/cases_generator/stack.py |  13 +-
 3 files changed, 358 insertions(+), 183 deletions(-)

diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index 03f73b383fe943..22eb937b8ea1df 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -187,9 +187,10 @@ incorrect_keys(PyObject *obj, uint32_t version)
 #define sym_new_truthiness _Py_uop_sym_new_truthiness
 
 #define JUMP_TO_LABEL(label) goto label;
-#define CHECK_STACK_BOUNDS() \
+#define CHECK_STACK_BOUNDS(offset) \
 do { \
-    if (!CURRENT_FRAME_IS_INIT_SHIM() && (STACK_LEVEL() < 0 || STACK_LEVEL() > STACK_SIZE())) { \
+    int stack_level = (int)(stack_pointer + (offset) - ctx->frame->stack); \
+    if (!CURRENT_FRAME_IS_INIT_SHIM() && (stack_level < 0 || stack_level > STACK_SIZE())) { \
         ctx->contradiction = true; \
         ctx->done = true; \
         break; \
diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h
index 98c094ac15b0fd..5a01169fa26f42 100644
--- a/Python/optimizer_cases.c.h
+++ b/Python/optimizer_cases.c.h
@@ -33,27 +33,30 @@
             if (sym_is_null(value)) {
                 ctx->done = true;
             }
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _LOAD_FAST: {
             JitOptRef value;
             value = GETLOCAL(oparg);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _LOAD_FAST_BORROW: {
             JitOptRef value;
             value = PyJitRef_Borrow(GETLOCAL(oparg));
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -62,9 +65,10 @@
             value = GETLOCAL(oparg);
             JitOptRef temp = sym_new_null(ctx);
             GETLOCAL(oparg) = temp;
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -74,9 +78,10 @@
             PyObject *val = PyTuple_GET_ITEM(co->co_consts, oparg);
             REPLACE_OP(this_instr, _LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)val);
             value = PyJitRef_Borrow(sym_new_const(ctx, val));
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -87,9 +92,10 @@
             assert(_Py_IsImmortal(val));
             REPLACE_OP(this_instr, _LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)val);
             value = PyJitRef_Borrow(sym_new_const(ctx, val));
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -97,8 +103,9 @@
             JitOptRef value;
             value = stack_pointer[-1];
             GETLOCAL(oparg) = value;
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -120,68 +127,78 @@
             else if (typ == &PyUnicode_Type) {
                 REPLACE_OP(this_instr, _POP_TOP_UNICODE, 0, 0);
             }
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _POP_TOP_NOP: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _POP_TOP_INT: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _POP_TOP_FLOAT: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _POP_TOP_UNICODE: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _POP_TWO: {
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _PUSH_NULL: {
             JitOptRef res;
             res = sym_new_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _END_FOR: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _POP_ITER: {
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _END_SEND: {
             JitOptRef val;
             val = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = val;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -504,15 +521,17 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             res = sym_new_compact_int(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -554,15 +573,17 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             res = sym_new_compact_int(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -604,15 +625,17 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             res = sym_new_compact_int(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -673,18 +696,20 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             res = sym_new_type(ctx, &PyFloat_Type);
             if (PyJitRef_IsBorrowed(left) && PyJitRef_IsBorrowed(right)) {
                 REPLACE_OP(this_instr, op_without_decref_inputs[opcode], oparg, 0);
             }
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -725,18 +750,20 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             res = sym_new_type(ctx, &PyFloat_Type);
             if (PyJitRef_IsBorrowed(left) && PyJitRef_IsBorrowed(right)) {
                 REPLACE_OP(this_instr, op_without_decref_inputs[opcode], oparg, 0);
             }
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -777,45 +804,50 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             res = sym_new_type(ctx, &PyFloat_Type);
             if (PyJitRef_IsBorrowed(left) && PyJitRef_IsBorrowed(right)) {
                 REPLACE_OP(this_instr, op_without_decref_inputs[opcode], oparg, 0);
             }
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BINARY_OP_MULTIPLY_FLOAT__NO_DECREF_INPUTS: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BINARY_OP_ADD_FLOAT__NO_DECREF_INPUTS: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BINARY_OP_SUBTRACT_FLOAT__NO_DECREF_INPUTS: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -856,15 +888,17 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             res = sym_new_type(ctx, &PyUnicode_Type);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -888,8 +922,9 @@
                 res = sym_new_type(ctx, &PyUnicode_Type);
             }
             GETLOCAL(this_instr->operand0) = res;
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -900,9 +935,10 @@
         case _BINARY_OP_EXTEND: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -920,42 +956,47 @@
             else {
                 res = sym_new_not_null(ctx);
             }
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer[-3] = res;
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _STORE_SLICE: {
+            CHECK_STACK_BOUNDS(-4);
             stack_pointer += -4;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BINARY_OP_SUBSCR_LIST_INT: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BINARY_OP_SUBSCR_LIST_SLICE: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BINARY_OP_SUBSCR_STR_INT: {
             JitOptRef res;
             res = sym_new_type(ctx, &PyUnicode_Type);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1002,9 +1043,10 @@
             else {
                 res = sym_new_not_null(ctx);
             }
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1031,18 +1073,20 @@
         case _BINARY_OP_SUBSCR_DICT: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BINARY_OP_SUBSCR_CHECK_FUNC: {
             JitOptRef getitem;
             getitem = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = getitem;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1050,45 +1094,52 @@
             JitOptRef new_frame;
             new_frame = PyJitRef_NULL;
             ctx->done = true;
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer[-3] = new_frame;
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _LIST_APPEND: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _SET_ADD: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _STORE_SUBSCR: {
+            CHECK_STACK_BOUNDS(-3);
             stack_pointer += -3;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _STORE_SUBSCR_LIST_INT: {
+            CHECK_STACK_BOUNDS(-3);
             stack_pointer += -3;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _STORE_SUBSCR_DICT: {
+            CHECK_STACK_BOUNDS(-3);
             stack_pointer += -3;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _DELETE_SUBSCR: {
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1102,9 +1153,10 @@
         case _CALL_INTRINSIC_2: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1112,9 +1164,9 @@
             JitOptRef retval;
             JitOptRef res;
             retval = stack_pointer[-1];
-            JitOptRef temp = PyJitRef_StripReferenceInfo(retval);
+            JitOptRef temp = PyJitRef_StripReferenceInfo(retval);CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             ctx->frame->stack_pointer = stack_pointer;
             PyCodeObject *returning_code = get_code_with_logging(this_instr);
             if (returning_code == NULL) {
@@ -1134,9 +1186,10 @@
             }
             stack_pointer = ctx->frame->stack_pointer;
             res = temp;
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1150,9 +1203,10 @@
         case _GET_ANEXT: {
             JitOptRef awaitable;
             awaitable = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = awaitable;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1177,9 +1231,9 @@
             JitOptRef retval;
             JitOptRef value;
             retval = stack_pointer[-1];
-            JitOptRef temp = PyJitRef_StripReferenceInfo(retval);
+            JitOptRef temp = PyJitRef_StripReferenceInfo(retval);CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             ctx->frame->stack_pointer = stack_pointer;
             PyCodeObject *returning_code = get_code_with_logging(this_instr);
             if (returning_code == NULL) {
@@ -1193,39 +1247,44 @@
             }
             stack_pointer = ctx->frame->stack_pointer;
             value = temp;
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _POP_EXCEPT: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _LOAD_COMMON_CONSTANT: {
             JitOptRef value;
             value = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _LOAD_BUILD_CLASS: {
             JitOptRef bc;
             bc = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = bc;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _STORE_NAME: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1242,8 +1301,9 @@
             for (int i = 0; i < oparg; i++) {
                 values[i] = sym_new_unknown(ctx);
             }
+            CHECK_STACK_BOUNDS(-1 + oparg);
             stack_pointer += -1 + oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1254,10 +1314,11 @@
             seq = stack_pointer[-1];
             val0 = sym_tuple_getitem(ctx, seq, 0);
             val1 = sym_tuple_getitem(ctx, seq, 1);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[-1] = val1;
             stack_pointer[0] = val0;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1269,8 +1330,9 @@
             for (int i = 0; i < oparg; i++) {
                 values[i] = sym_tuple_getitem(ctx, seq, oparg - i - 1);
             }
+            CHECK_STACK_BOUNDS(-1 + oparg);
             stack_pointer += -1 + oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1280,8 +1342,9 @@
             for (int _i = oparg; --_i >= 0;) {
                 values[_i] = sym_new_not_null(ctx);
             }
+            CHECK_STACK_BOUNDS(-1 + oparg);
             stack_pointer += -1 + oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1295,26 +1358,30 @@
             for (int i = 0; i < totalargs; i++) {
                 values[i] = sym_new_unknown(ctx);
             }
+            CHECK_STACK_BOUNDS((oparg & 0xFF) + (oparg >> 8));
             stack_pointer += (oparg & 0xFF) + (oparg >> 8);
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _STORE_ATTR: {
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _DELETE_ATTR: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _STORE_GLOBAL: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1325,9 +1392,10 @@
         case _LOAD_LOCALS: {
             JitOptRef locals;
             locals = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = locals;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1336,9 +1404,10 @@
         case _LOAD_NAME: {
             JitOptRef v;
             v = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = v;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1346,8 +1415,9 @@
             JitOptRef *res;
             res = &stack_pointer[0];
             res[0] = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1361,8 +1431,9 @@
             else {
                 REPLACE_OP(this_instr, _NOP, 0, 0);
             }
+            CHECK_STACK_BOUNDS((oparg & 1));
             stack_pointer += (oparg & 1);
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1426,9 +1497,10 @@
             else {
                 res = sym_new_const(ctx, cnst);
             }
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1462,9 +1534,10 @@
             else {
                 res = sym_new_const(ctx, cnst);
             }
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1490,15 +1563,17 @@
         case _LOAD_DEREF: {
             JitOptRef value;
             value = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _STORE_DEREF: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1509,27 +1584,30 @@
         case _BUILD_STRING: {
             JitOptRef str;
             str = sym_new_type(ctx, &PyUnicode_Type);
+            CHECK_STACK_BOUNDS(1 - oparg);
             stack_pointer[-oparg] = str;
             stack_pointer += 1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BUILD_INTERPOLATION: {
             JitOptRef interpolation;
             interpolation = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1 - (oparg & 1));
             stack_pointer[-2 - (oparg & 1)] = interpolation;
             stack_pointer += -1 - (oparg & 1);
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BUILD_TEMPLATE: {
             JitOptRef template;
             template = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = template;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1538,48 +1616,54 @@
             JitOptRef tup;
             values = &stack_pointer[-oparg];
             tup = sym_new_tuple(ctx, oparg, values);
+            CHECK_STACK_BOUNDS(1 - oparg);
             stack_pointer[-oparg] = tup;
             stack_pointer += 1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BUILD_LIST: {
             JitOptRef list;
             list = sym_new_type(ctx, &PyList_Type);
+            CHECK_STACK_BOUNDS(1 - oparg);
             stack_pointer[-oparg] = list;
             stack_pointer += 1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _LIST_EXTEND: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _SET_UPDATE: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BUILD_SET: {
             JitOptRef set;
             set = sym_new_type(ctx, &PySet_Type);
+            CHECK_STACK_BOUNDS(1 - oparg);
             stack_pointer[-oparg] = set;
             stack_pointer += 1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BUILD_MAP: {
             JitOptRef map;
             map = sym_new_type(ctx, &PyDict_Type);
+            CHECK_STACK_BOUNDS(1 - oparg*2);
             stack_pointer[-oparg*2] = map;
             stack_pointer += 1 - oparg*2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1588,29 +1672,33 @@
         }
 
         case _DICT_UPDATE: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _DICT_MERGE: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _MAP_ADD: {
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _LOAD_SUPER_ATTR_ATTR: {
             JitOptRef attr_st;
             attr_st = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer[-3] = attr_st;
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1619,10 +1707,11 @@
             JitOptRef self_or_null;
             attr = sym_new_not_null(ctx);
             self_or_null = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-3] = attr;
             stack_pointer[-2] = self_or_null;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1638,8 +1727,9 @@
             if (oparg & 1) {
                 self_or_null[0] = sym_new_unknown(ctx);
             }
+            CHECK_STACK_BOUNDS((oparg&1));
             stack_pointer += (oparg&1);
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1780,20 +1870,23 @@
         }
 
         case _STORE_ATTR_INSTANCE_VALUE: {
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _STORE_ATTR_WITH_HINT: {
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _STORE_ATTR_SLOT: {
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1840,9 +1933,10 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             if (oparg & 16) {
@@ -1851,9 +1945,10 @@
             else {
                 res = _Py_uop_sym_new_not_null(ctx);
             }
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1891,15 +1986,17 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             res = sym_new_type(ctx, &PyBool_Type);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1941,15 +2038,17 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             res = sym_new_type(ctx, &PyBool_Type);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -1989,24 +2088,27 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             res = sym_new_type(ctx, &PyBool_Type);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _IS_OP: {
             JitOptRef b;
             b = sym_new_type(ctx, &PyBool_Type);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = b;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2042,15 +2144,17 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = b;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             b = sym_new_type(ctx, &PyBool_Type);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = b;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2068,18 +2172,20 @@
         case _CONTAINS_OP_SET: {
             JitOptRef b;
             b = sym_new_type(ctx, &PyBool_Type);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = b;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _CONTAINS_OP_DICT: {
             JitOptRef b;
             b = sym_new_type(ctx, &PyBool_Type);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = b;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2103,18 +2209,20 @@
         case _IMPORT_NAME: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _IMPORT_FROM: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2148,52 +2256,57 @@
                 if (_Py_IsImmortal(temp)) {
                     REPLACE_OP(this_instr, _LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)temp);
                 }
-                len = sym_new_const(ctx, temp);
+                len = sym_new_const(ctx, temp);CHECK_STACK_BOUNDS(1);
                 stack_pointer[0] = len;
                 stack_pointer += 1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 Py_DECREF(temp);
                 stack_pointer += -1;
             }
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = len;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _MATCH_CLASS: {
             JitOptRef attrs;
             attrs = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer[-3] = attrs;
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _MATCH_MAPPING: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _MATCH_SEQUENCE: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _MATCH_KEYS: {
             JitOptRef values_or_none;
             values_or_none = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = values_or_none;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2210,10 +2323,11 @@
                 iter = sym_new_not_null(ctx);
                 index_or_null = sym_new_unknown(ctx);
             }
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[-1] = iter;
             stack_pointer[0] = index_or_null;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2229,9 +2343,10 @@
         case _FOR_ITER_TIER_TWO: {
             JitOptRef next;
             next = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = next;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2252,9 +2367,10 @@
         case _ITER_NEXT_LIST_TIER_TWO: {
             JitOptRef next;
             next = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = next;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2277,9 +2393,10 @@
         case _ITER_NEXT_TUPLE: {
             JitOptRef next;
             next = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = next;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2296,9 +2413,10 @@
         case _ITER_NEXT_RANGE: {
             JitOptRef next;
             next = sym_new_type(ctx, &PyLong_Type);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = next;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2306,9 +2424,10 @@
             JitOptRef gen_frame;
             gen_frame = PyJitRef_NULL;
             ctx->done = true;
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = gen_frame;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2319,8 +2438,9 @@
             method_and_self = &stack_pointer[-1];
             method_and_self[0] = sym_new_null(ctx);
             method_and_self[1] = self;
+            CHECK_STACK_BOUNDS(1);
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2335,9 +2455,10 @@
         case _WITH_EXCEPT_START: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2346,10 +2467,11 @@
             JitOptRef new_exc;
             prev_exc = sym_new_not_null(ctx);
             new_exc = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[-1] = prev_exc;
             stack_pointer[0] = new_exc;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2374,10 +2496,11 @@
                            _LOAD_CONST_UNDER_INLINE_BORROW,
                            _LOAD_CONST_UNDER_INLINE);
             self = owner;
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2394,10 +2517,11 @@
                            _LOAD_CONST_UNDER_INLINE_BORROW,
                            _LOAD_CONST_UNDER_INLINE);
             self = owner;
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2448,10 +2572,11 @@
                            _LOAD_CONST_UNDER_INLINE_BORROW,
                            _LOAD_CONST_UNDER_INLINE);
             self = owner;
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[-1] = attr;
             stack_pointer[0] = self;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2483,9 +2608,10 @@
                 break;
             }
             new_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, NULL, 0));
+            CHECK_STACK_BOUNDS(-1 - oparg);
             stack_pointer[-2 - oparg] = new_frame;
             stack_pointer += -1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2531,9 +2657,10 @@
         case _CALL_NON_PY_GENERAL: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1 - oparg);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2616,17 +2743,19 @@
             } else {
                 new_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, NULL, 0));
             }
+            CHECK_STACK_BOUNDS(-1 - oparg);
             stack_pointer[-2 - oparg] = new_frame;
             stack_pointer += -1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _PUSH_FRAME: {
             JitOptRef new_frame;
             new_frame = stack_pointer[-1];
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             if (!CURRENT_FRAME_IS_INIT_SHIM()) {
                 ctx->frame->stack_pointer = stack_pointer;
             }
@@ -2703,9 +2832,10 @@
             else {
                 res = sym_new_not_null(ctx);
             }
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer[-3] = res;
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2729,9 +2859,10 @@
             else {
                 res = sym_new_type(ctx, &PyUnicode_Type);
             }
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer[-3] = res;
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2755,9 +2886,10 @@
             else {
                 res = sym_new_type(ctx, &PyTuple_Type);
             }
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer[-3] = res;
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2797,51 +2929,57 @@
             assert((this_instr + 1)->opcode == _PUSH_FRAME);
             PyCodeObject *co = get_code_with_logging((this_instr + 1));
             init_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, args-1, oparg+1));
+            CHECK_STACK_BOUNDS(-1 - oparg);
             stack_pointer[-2 - oparg] = init_frame;
             stack_pointer += -1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _EXIT_INIT_CHECK: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _CALL_BUILTIN_CLASS: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1 - oparg);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _CALL_BUILTIN_O: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1 - oparg);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _CALL_BUILTIN_FAST: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1 - oparg);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _CALL_BUILTIN_FAST_WITH_KEYWORDS: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1 - oparg);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2871,16 +3009,17 @@
                     REPLACE_OP(this_instr, _POP_CALL_ONE_LOAD_CONST_INLINE_BORROW,
                            0, (uintptr_t)temp);
                 }
-                res = sym_new_const(ctx, temp);
+                res = sym_new_const(ctx, temp);CHECK_STACK_BOUNDS(-2);
                 stack_pointer[-3] = res;
                 stack_pointer += -2;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 Py_DECREF(temp);
                 stack_pointer += 2;
             }
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer[-3] = res;
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2912,9 +3051,10 @@
                 sym_set_const(res, out);
                 REPLACE_OP(this_instr, _POP_CALL_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)out);
             }
+            CHECK_STACK_BOUNDS(-3);
             stack_pointer[-4] = res;
             stack_pointer += -3;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2930,44 +3070,49 @@
         }
 
         case _CALL_LIST_APPEND: {
+            CHECK_STACK_BOUNDS(-3);
             stack_pointer += -3;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _CALL_METHOD_DESCRIPTOR_O: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1 - oparg);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _CALL_METHOD_DESCRIPTOR_FAST_WITH_KEYWORDS: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1 - oparg);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _CALL_METHOD_DESCRIPTOR_NOARGS: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1 - oparg);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _CALL_METHOD_DESCRIPTOR_FAST: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1 - oparg);
             stack_pointer[-2 - oparg] = res;
             stack_pointer += -1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -2988,9 +3133,10 @@
                 break;
             }
             new_frame = PyJitRef_Wrap((JitOptSymbol *)frame_new(ctx, co, 0, NULL, 0));
+            CHECK_STACK_BOUNDS(-2 - oparg);
             stack_pointer[-3 - oparg] = new_frame;
             stack_pointer += -2 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3013,9 +3159,10 @@
         case _CALL_KW_NON_PY: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-2 - oparg);
             stack_pointer[-3 - oparg] = res;
             stack_pointer += -2 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3035,9 +3182,10 @@
         case _SET_FUNCTION_ATTRIBUTE: {
             JitOptRef func_out;
             func_out = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = func_out;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3056,18 +3204,20 @@
             }
             stack_pointer = ctx->frame->stack_pointer;
             res = sym_new_unknown(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = res;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _BUILD_SLICE: {
             JitOptRef slice;
             slice = sym_new_type(ctx, &PySlice_Type);
+            CHECK_STACK_BOUNDS(1 - oparg);
             stack_pointer[-oparg] = slice;
             stack_pointer += 1 - oparg;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3088,9 +3238,10 @@
         case _FORMAT_WITH_SPEC: {
             JitOptRef res;
             res = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3100,9 +3251,10 @@
             bottom = stack_pointer[-1 - (oparg-1)];
             assert(oparg > 0);
             top = bottom;
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = top;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3139,9 +3291,10 @@
                         REPLACE_OP(this_instr, _POP_TWO_LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)result);
                     }
                 }
+                CHECK_STACK_BOUNDS(-1);
                 stack_pointer[-2] = res;
                 stack_pointer += -1;
-                CHECK_STACK_BOUNDS();
+                ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
                 break;
             }
             bool lhs_int = sym_matches_type(lhs, &PyLong_Type);
@@ -3177,9 +3330,10 @@
             else {
                 res = sym_new_type(ctx, &PyFloat_Type);
             }
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = res;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3224,8 +3378,9 @@
                 eliminate_pop_guard(this_instr, value != Py_True);
             }
             sym_set_const(flag, Py_True);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3238,8 +3393,9 @@
                 eliminate_pop_guard(this_instr, value != Py_False);
             }
             sym_set_const(flag, Py_False);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3256,8 +3412,9 @@
                 eliminate_pop_guard(this_instr, true);
             }
             sym_set_const(val, Py_None);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3273,8 +3430,9 @@
                 assert(!sym_matches_type(val, &_PyNone_Type));
                 eliminate_pop_guard(this_instr, false);
             }
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3317,9 +3475,10 @@
             JitOptRef value;
             PyObject *ptr = (PyObject *)this_instr->operand0;
             value = sym_new_const(ctx, ptr);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3335,27 +3494,31 @@
             JitOptRef value;
             PyObject *ptr = (PyObject *)this_instr->operand0;
             value = PyJitRef_Borrow(sym_new_const(ctx, ptr));
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = value;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _POP_CALL: {
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _POP_CALL_ONE: {
+            CHECK_STACK_BOUNDS(-3);
             stack_pointer += -3;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
         case _POP_CALL_TWO: {
+            CHECK_STACK_BOUNDS(-4);
             stack_pointer += -4;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3370,9 +3533,10 @@
         case _POP_TWO_LOAD_CONST_INLINE_BORROW: {
             JitOptRef value;
             value = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = value;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3380,9 +3544,10 @@
             JitOptRef value;
             PyObject *ptr = (PyObject *)this_instr->operand0;
             value = PyJitRef_Borrow(sym_new_const(ctx, ptr));
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer[-2] = value;
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3390,9 +3555,10 @@
             JitOptRef value;
             PyObject *ptr = (PyObject *)this_instr->operand0;
             value = PyJitRef_Borrow(sym_new_const(ctx, ptr));
+            CHECK_STACK_BOUNDS(-2);
             stack_pointer[-3] = value;
             stack_pointer += -2;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3400,9 +3566,10 @@
             JitOptRef value;
             PyObject *ptr = (PyObject *)this_instr->operand0;
             value = PyJitRef_Borrow(sym_new_const(ctx, ptr));
+            CHECK_STACK_BOUNDS(-3);
             stack_pointer[-4] = value;
             stack_pointer += -3;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3411,10 +3578,11 @@
             JitOptRef new;
             value = sym_new_not_null(ctx);
             new = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[-1] = value;
             stack_pointer[0] = new;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
@@ -3423,10 +3591,11 @@
             JitOptRef new;
             value = sym_new_not_null(ctx);
             new = sym_new_not_null(ctx);
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[-1] = value;
             stack_pointer[0] = new;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
 
diff --git a/Tools/cases_generator/stack.py b/Tools/cases_generator/stack.py
index f416e40b329466..71dbd6cddbd5db 100644
--- a/Tools/cases_generator/stack.py
+++ b/Tools/cases_generator/stack.py
@@ -297,10 +297,7 @@ def _save_physical_sp(self, out: CWriter) -> None:
             diff = self.logical_sp - self.physical_sp
             out.start_line()
             out.emit(f"stack_pointer += {diff.to_c()};\n")
-            if self.check_stack_bounds:
-                out.emit("CHECK_STACK_BOUNDS();\n")
-            else:
-                out.emit(f"ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);\n")
+            out.emit(f"ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);\n")
             self.physical_sp = self.logical_sp
             self._print(out)
 
@@ -320,8 +317,16 @@ def save_variables(self, out: CWriter) -> None:
                 self._print(out)
             var_offset = var_offset.push(var.item)
 
+    def stack_bound_check(self, out: CWriter):
+        if not self.check_stack_bounds:
+            return
+        if self.physical_sp != self.logical_sp:
+            diff =  self.logical_sp - self.physical_sp
+            out.emit(f"CHECK_STACK_BOUNDS({diff});\n")
+
     def flush(self, out: CWriter) -> None:
         self._print(out)
+        self.stack_bound_check(out)
         self.save_variables(out)
         self._save_physical_sp(out)
         out.start_line()

From 558c2cf6f190fc79fdbf15e640e1377d2e0ca258 Mon Sep 17 00:00:00 2001
From: Ken Jin <kenjin4096@gmail.com>
Date: Thu, 4 Dec 2025 13:26:42 +0000
Subject: [PATCH 6/8] fix tests

---
 Lib/test/test_generated_cases.py | 12 ++++++++----
 Python/optimizer_analysis.c      |  2 +-
 Python/optimizer_cases.c.h       | 12 ++++++++----
 Tools/cases_generator/stack.py   |  3 ++-
 4 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/Lib/test/test_generated_cases.py b/Lib/test/test_generated_cases.py
index e6d0493cd46855..de0dbab480f5e5 100644
--- a/Lib/test/test_generated_cases.py
+++ b/Lib/test/test_generated_cases.py
@@ -2115,8 +2115,9 @@ def test_validate_uop_unused_input(self):
         """
         output = """
         case OP: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
         """
@@ -2132,8 +2133,9 @@ def test_validate_uop_unused_input(self):
         """
         output = """
         case OP: {
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
         """
@@ -2153,9 +2155,10 @@ def test_validate_uop_unused_output(self):
         case OP: {
             JitOptRef foo;
             foo = NULL;
+            CHECK_STACK_BOUNDS(1);
             stack_pointer[0] = foo;
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
         """
@@ -2172,8 +2175,9 @@ def test_validate_uop_unused_output(self):
         """
         output = """
         case OP: {
+            CHECK_STACK_BOUNDS(1);
             stack_pointer += 1;
-            CHECK_STACK_BOUNDS();
+            ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             break;
         }
         """
diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index 22eb937b8ea1df..5f466a6c961db6 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -190,7 +190,7 @@ incorrect_keys(PyObject *obj, uint32_t version)
 #define CHECK_STACK_BOUNDS(offset) \
 do { \
     int stack_level = (int)(stack_pointer + (offset) - ctx->frame->stack); \
-    if (!CURRENT_FRAME_IS_INIT_SHIM() && (stack_level < 0 || stack_level > STACK_SIZE())) { \
+    if (stack_level < 0 || stack_level > STACK_SIZE()) { \
         ctx->contradiction = true; \
         ctx->done = true; \
         break; \
diff --git a/Python/optimizer_cases.c.h b/Python/optimizer_cases.c.h
index 5a01169fa26f42..85bebed58677ed 100644
--- a/Python/optimizer_cases.c.h
+++ b/Python/optimizer_cases.c.h
@@ -1164,7 +1164,8 @@
             JitOptRef retval;
             JitOptRef res;
             retval = stack_pointer[-1];
-            JitOptRef temp = PyJitRef_StripReferenceInfo(retval);CHECK_STACK_BOUNDS(-1);
+            JitOptRef temp = PyJitRef_StripReferenceInfo(retval);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
             ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             ctx->frame->stack_pointer = stack_pointer;
@@ -1231,7 +1232,8 @@
             JitOptRef retval;
             JitOptRef value;
             retval = stack_pointer[-1];
-            JitOptRef temp = PyJitRef_StripReferenceInfo(retval);CHECK_STACK_BOUNDS(-1);
+            JitOptRef temp = PyJitRef_StripReferenceInfo(retval);
+            CHECK_STACK_BOUNDS(-1);
             stack_pointer += -1;
             ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
             ctx->frame->stack_pointer = stack_pointer;
@@ -2256,7 +2258,8 @@
                 if (_Py_IsImmortal(temp)) {
                     REPLACE_OP(this_instr, _LOAD_CONST_INLINE_BORROW, 0, (uintptr_t)temp);
                 }
-                len = sym_new_const(ctx, temp);CHECK_STACK_BOUNDS(1);
+                len = sym_new_const(ctx, temp);
+                CHECK_STACK_BOUNDS(1);
                 stack_pointer[0] = len;
                 stack_pointer += 1;
                 ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
@@ -3009,7 +3012,8 @@
                     REPLACE_OP(this_instr, _POP_CALL_ONE_LOAD_CONST_INLINE_BORROW,
                            0, (uintptr_t)temp);
                 }
-                res = sym_new_const(ctx, temp);CHECK_STACK_BOUNDS(-2);
+                res = sym_new_const(ctx, temp);
+                CHECK_STACK_BOUNDS(-2);
                 stack_pointer[-3] = res;
                 stack_pointer += -2;
                 ASSERT_WITHIN_STACK_BOUNDS(__FILE__, __LINE__);
diff --git a/Tools/cases_generator/stack.py b/Tools/cases_generator/stack.py
index 71dbd6cddbd5db..d20f852eefe405 100644
--- a/Tools/cases_generator/stack.py
+++ b/Tools/cases_generator/stack.py
@@ -321,7 +321,8 @@ def stack_bound_check(self, out: CWriter):
         if not self.check_stack_bounds:
             return
         if self.physical_sp != self.logical_sp:
-            diff =  self.logical_sp - self.physical_sp
+            diff = self.logical_sp - self.physical_sp
+            out.start_line()
             out.emit(f"CHECK_STACK_BOUNDS({diff});\n")
 
     def flush(self, out: CWriter) -> None:

From a1b0ff1db3f3d0fe5a5803131f0724e787b811b9 Mon Sep 17 00:00:00 2001
From: Ken Jin <kenjin4096@gmail.com>
Date: Thu, 4 Dec 2025 13:32:25 +0000
Subject: [PATCH 7/8] fix mypy

---
 Tools/cases_generator/stack.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Tools/cases_generator/stack.py b/Tools/cases_generator/stack.py
index d20f852eefe405..53499558aed876 100644
--- a/Tools/cases_generator/stack.py
+++ b/Tools/cases_generator/stack.py
@@ -317,7 +317,7 @@ def save_variables(self, out: CWriter) -> None:
                 self._print(out)
             var_offset = var_offset.push(var.item)
 
-    def stack_bound_check(self, out: CWriter):
+    def stack_bound_check(self, out: CWriter) -> None:
         if not self.check_stack_bounds:
             return
         if self.physical_sp != self.logical_sp:

From 32631e809aed92f6e5d48be03f9b6b283e743498 Mon Sep 17 00:00:00 2001
From: Ken Jin <kenjin4096@gmail.com>
Date: Thu, 4 Dec 2025 13:54:14 +0000
Subject: [PATCH 8/8] refactor into own function

---
 Python/optimizer_analysis.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index 5f466a6c961db6..51722556554609 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -187,15 +187,27 @@ incorrect_keys(PyObject *obj, uint32_t version)
 #define sym_new_truthiness _Py_uop_sym_new_truthiness
 
 #define JUMP_TO_LABEL(label) goto label;
+
+static int
+check_stack_bounds(JitOptContext *ctx, JitOptRef *stack_pointer, int offset, int opcode)
+{
+    int stack_level = (int)(stack_pointer + (offset) - ctx->frame->stack);
+    int should_check = !CURRENT_FRAME_IS_INIT_SHIM() ||
+        (opcode == _RETURN_VALUE) ||
+        (opcode == _RETURN_GENERATOR) ||
+        (opcode == _YIELD_VALUE);
+    if (should_check && (stack_level < 0 || stack_level > STACK_SIZE())) {
+        ctx->contradiction = true;
+        ctx->done = true;
+        return 1;
+    }
+    return 0;
+}
+
 #define CHECK_STACK_BOUNDS(offset) \
-do { \
-    int stack_level = (int)(stack_pointer + (offset) - ctx->frame->stack); \
-    if (stack_level < 0 || stack_level > STACK_SIZE()) { \
-        ctx->contradiction = true; \
-        ctx->done = true; \
+    if (check_stack_bounds(ctx, stack_pointer, offset, opcode)) { \
         break; \
     } \
-} while (0);
 
 static int
 optimize_to_bool(