From 8e02ed8f317fb8247700732244ea64af0eb4bb27 Mon Sep 17 00:00:00 2001
From: Mark Shannon <mark@hotpy.org>
Date: Wed, 21 Jun 2023 06:40:59 +0100
Subject: [PATCH 1/4] Check eval-breaker in ENTER_EXECUTOR.

---
 Python/bytecodes.c         |  15 +-
 Python/ceval_macros.h      |   4 +-
 Python/generated_cases.c.h | 343 +++++++++++++++++++------------------
 3 files changed, 183 insertions(+), 179 deletions(-)

diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index 02857104f5a4d5..c34dc568b646ed 100644
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -142,8 +142,8 @@ dummy_func(
                 ERROR_IF(err, error);
                 next_instr--;
             }
-            else if (_Py_atomic_load_relaxed_int32(&tstate->interp->ceval.eval_breaker) && oparg < 2) {
-                goto handle_eval_breaker;
+            else if (oparg < 2) {
+                CHECK_EVAL_BREAKER();
             }
         }
 
@@ -159,6 +159,9 @@ dummy_func(
                 next_instr--;
             }
             else {
+                if (oparg < 2) {
+                    CHECK_EVAL_BREAKER();
+                }
                 _PyFrame_SetStackPointer(frame, stack_pointer);
                 int err = _Py_call_instrumentation(
                         tstate, oparg > 0, frame, next_instr-1);
@@ -169,9 +172,6 @@ dummy_func(
                     next_instr = frame->prev_instr;
                     DISPATCH();
                 }
-                if (_Py_atomic_load_relaxed_int32(&tstate->interp->ceval.eval_breaker) && oparg < 2) {
-                    goto handle_eval_breaker;
-                }
             }
         }
 
@@ -2143,6 +2143,7 @@ dummy_func(
         }
 
         inst(JUMP_BACKWARD, (--)) {
+            CHECK_EVAL_BREAKER();
             _Py_CODEUNIT *here = next_instr - 1;
             assert(oparg <= INSTR_OFFSET());
             JUMPBY(1-oparg);
@@ -2160,7 +2161,6 @@ dummy_func(
                 goto resume_frame;
             }
             #endif  /* ENABLE_SPECIALIZATION */
-            CHECK_EVAL_BREAKER();
         }
 
         pseudo(JUMP) = {
@@ -2174,6 +2174,7 @@ dummy_func(
         };
 
         inst(ENTER_EXECUTOR, (--)) {
+            CHECK_EVAL_BREAKER();
             PyCodeObject *code = _PyFrame_GetCode(frame);
             _PyExecutorObject *executor = (_PyExecutorObject *)code->co_executors->executors[oparg&255];
             Py_INCREF(executor);
@@ -3512,8 +3513,8 @@ dummy_func(
         }
 
         inst(INSTRUMENTED_JUMP_BACKWARD, ( -- )) {
-            INSTRUMENTED_JUMP(next_instr-1, next_instr+1-oparg, PY_MONITORING_EVENT_JUMP);
             CHECK_EVAL_BREAKER();
+            INSTRUMENTED_JUMP(next_instr-1, next_instr+1-oparg, PY_MONITORING_EVENT_JUMP);
         }
 
         inst(INSTRUMENTED_POP_JUMP_IF_TRUE, ( -- )) {
diff --git a/Python/ceval_macros.h b/Python/ceval_macros.h
index 0d41ef5a14cef4..72800aaaaa2ac4 100644
--- a/Python/ceval_macros.h
+++ b/Python/ceval_macros.h
@@ -117,7 +117,9 @@
 #define CHECK_EVAL_BREAKER() \
     _Py_CHECK_EMSCRIPTEN_SIGNALS_PERIODICALLY(); \
     if (_Py_atomic_load_relaxed_int32(&tstate->interp->ceval.eval_breaker)) { \
-        goto handle_eval_breaker; \
+        if (_Py_HandlePending(tstate) != 0) { \
+            goto error; \
+        } \
     }
 
 
diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
index 43cfd4a882c73a..6005b153c1b631 100644
--- a/Python/generated_cases.c.h
+++ b/Python/generated_cases.c.h
@@ -17,8 +17,8 @@
                 if (err) goto error;
                 next_instr--;
             }
-            else if (_Py_atomic_load_relaxed_int32(&tstate->interp->ceval.eval_breaker) && oparg < 2) {
-                goto handle_eval_breaker;
+            else if (oparg < 2) {
+                CHECK_EVAL_BREAKER();
             }
             #line 24 "Python/generated_cases.c.h"
             DISPATCH();
@@ -37,6 +37,9 @@
                 next_instr--;
             }
             else {
+                if (oparg < 2) {
+                    CHECK_EVAL_BREAKER();
+                }
                 _PyFrame_SetStackPointer(frame, stack_pointer);
                 int err = _Py_call_instrumentation(
                         tstate, oparg > 0, frame, next_instr-1);
@@ -47,9 +50,6 @@
                     next_instr = frame->prev_instr;
                     DISPATCH();
                 }
-                if (_Py_atomic_load_relaxed_int32(&tstate->interp->ceval.eval_breaker) && oparg < 2) {
-                    goto handle_eval_breaker;
-                }
             }
             #line 55 "Python/generated_cases.c.h"
             DISPATCH();
@@ -3065,6 +3065,7 @@
 
         TARGET(JUMP_BACKWARD) {
             #line 2146 "Python/bytecodes.c"
+            CHECK_EVAL_BREAKER();
             _Py_CODEUNIT *here = next_instr - 1;
             assert(oparg <= INSTR_OFFSET());
             JUMPBY(1-oparg);
@@ -3082,13 +3083,13 @@
                 goto resume_frame;
             }
             #endif  /* ENABLE_SPECIALIZATION */
-            #line 3086 "Python/generated_cases.c.h"
-            CHECK_EVAL_BREAKER();
+            #line 3087 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(ENTER_EXECUTOR) {
             #line 2177 "Python/bytecodes.c"
+            CHECK_EVAL_BREAKER();
             PyCodeObject *code = _PyFrame_GetCode(frame);
             _PyExecutorObject *executor = (_PyExecutorObject *)code->co_executors->executors[oparg&255];
             Py_INCREF(executor);
@@ -3098,20 +3099,20 @@
                 goto resume_with_error;
             }
             goto resume_frame;
-            #line 3102 "Python/generated_cases.c.h"
+            #line 3103 "Python/generated_cases.c.h"
         }
 
         TARGET(POP_JUMP_IF_FALSE) {
             PyObject *cond = stack_pointer[-1];
-            #line 2189 "Python/bytecodes.c"
+            #line 2190 "Python/bytecodes.c"
             if (Py_IsFalse(cond)) {
                 JUMPBY(oparg);
             }
             else if (!Py_IsTrue(cond)) {
                 int err = PyObject_IsTrue(cond);
-            #line 3113 "Python/generated_cases.c.h"
+            #line 3114 "Python/generated_cases.c.h"
                 Py_DECREF(cond);
-            #line 2195 "Python/bytecodes.c"
+            #line 2196 "Python/bytecodes.c"
                 if (err == 0) {
                     JUMPBY(oparg);
                 }
@@ -3119,22 +3120,22 @@
                     if (err < 0) goto pop_1_error;
                 }
             }
-            #line 3123 "Python/generated_cases.c.h"
+            #line 3124 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
 
         TARGET(POP_JUMP_IF_TRUE) {
             PyObject *cond = stack_pointer[-1];
-            #line 2205 "Python/bytecodes.c"
+            #line 2206 "Python/bytecodes.c"
             if (Py_IsTrue(cond)) {
                 JUMPBY(oparg);
             }
             else if (!Py_IsFalse(cond)) {
                 int err = PyObject_IsTrue(cond);
-            #line 3136 "Python/generated_cases.c.h"
+            #line 3137 "Python/generated_cases.c.h"
                 Py_DECREF(cond);
-            #line 2211 "Python/bytecodes.c"
+            #line 2212 "Python/bytecodes.c"
                 if (err > 0) {
                     JUMPBY(oparg);
                 }
@@ -3142,63 +3143,63 @@
                     if (err < 0) goto pop_1_error;
                 }
             }
-            #line 3146 "Python/generated_cases.c.h"
+            #line 3147 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
 
         TARGET(POP_JUMP_IF_NOT_NONE) {
             PyObject *value = stack_pointer[-1];
-            #line 2221 "Python/bytecodes.c"
+            #line 2222 "Python/bytecodes.c"
             if (!Py_IsNone(value)) {
-            #line 3155 "Python/generated_cases.c.h"
+            #line 3156 "Python/generated_cases.c.h"
                 Py_DECREF(value);
-            #line 2223 "Python/bytecodes.c"
+            #line 2224 "Python/bytecodes.c"
                 JUMPBY(oparg);
             }
-            #line 3160 "Python/generated_cases.c.h"
+            #line 3161 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
 
         TARGET(POP_JUMP_IF_NONE) {
             PyObject *value = stack_pointer[-1];
-            #line 2228 "Python/bytecodes.c"
+            #line 2229 "Python/bytecodes.c"
             if (Py_IsNone(value)) {
                 JUMPBY(oparg);
             }
             else {
-            #line 3172 "Python/generated_cases.c.h"
+            #line 3173 "Python/generated_cases.c.h"
                 Py_DECREF(value);
-            #line 2233 "Python/bytecodes.c"
+            #line 2234 "Python/bytecodes.c"
             }
-            #line 3176 "Python/generated_cases.c.h"
+            #line 3177 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
 
         TARGET(JUMP_BACKWARD_NO_INTERRUPT) {
-            #line 2237 "Python/bytecodes.c"
+            #line 2238 "Python/bytecodes.c"
             /* This bytecode is used in the `yield from` or `await` loop.
              * If there is an interrupt, we want it handled in the innermost
              * generator or coroutine, so we deliberately do not check it here.
              * (see bpo-30039).
              */
             JUMPBY(-oparg);
-            #line 3189 "Python/generated_cases.c.h"
+            #line 3190 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(GET_LEN) {
             PyObject *obj = stack_pointer[-1];
             PyObject *len_o;
-            #line 2246 "Python/bytecodes.c"
+            #line 2247 "Python/bytecodes.c"
             // PUSH(len(TOS))
             Py_ssize_t len_i = PyObject_Length(obj);
             if (len_i < 0) goto error;
             len_o = PyLong_FromSsize_t(len_i);
             if (len_o == NULL) goto error;
-            #line 3202 "Python/generated_cases.c.h"
+            #line 3203 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = len_o;
             DISPATCH();
@@ -3209,16 +3210,16 @@
             PyObject *type = stack_pointer[-2];
             PyObject *subject = stack_pointer[-3];
             PyObject *attrs;
-            #line 2254 "Python/bytecodes.c"
+            #line 2255 "Python/bytecodes.c"
             // Pop TOS and TOS1. Set TOS to a tuple of attributes on success, or
             // None on failure.
             assert(PyTuple_CheckExact(names));
             attrs = match_class(tstate, subject, type, oparg, names);
-            #line 3218 "Python/generated_cases.c.h"
+            #line 3219 "Python/generated_cases.c.h"
             Py_DECREF(subject);
             Py_DECREF(type);
             Py_DECREF(names);
-            #line 2259 "Python/bytecodes.c"
+            #line 2260 "Python/bytecodes.c"
             if (attrs) {
                 assert(PyTuple_CheckExact(attrs));  // Success!
             }
@@ -3226,7 +3227,7 @@
                 if (_PyErr_Occurred(tstate)) goto pop_3_error;
                 attrs = Py_None;  // Failure!
             }
-            #line 3230 "Python/generated_cases.c.h"
+            #line 3231 "Python/generated_cases.c.h"
             STACK_SHRINK(2);
             stack_pointer[-1] = attrs;
             DISPATCH();
@@ -3235,10 +3236,10 @@
         TARGET(MATCH_MAPPING) {
             PyObject *subject = stack_pointer[-1];
             PyObject *res;
-            #line 2269 "Python/bytecodes.c"
+            #line 2270 "Python/bytecodes.c"
             int match = Py_TYPE(subject)->tp_flags & Py_TPFLAGS_MAPPING;
             res = match ? Py_True : Py_False;
-            #line 3242 "Python/generated_cases.c.h"
+            #line 3243 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             DISPATCH();
@@ -3247,10 +3248,10 @@
         TARGET(MATCH_SEQUENCE) {
             PyObject *subject = stack_pointer[-1];
             PyObject *res;
-            #line 2274 "Python/bytecodes.c"
+            #line 2275 "Python/bytecodes.c"
             int match = Py_TYPE(subject)->tp_flags & Py_TPFLAGS_SEQUENCE;
             res = match ? Py_True : Py_False;
-            #line 3254 "Python/generated_cases.c.h"
+            #line 3255 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             DISPATCH();
@@ -3260,11 +3261,11 @@
             PyObject *keys = stack_pointer[-1];
             PyObject *subject = stack_pointer[-2];
             PyObject *values_or_none;
-            #line 2279 "Python/bytecodes.c"
+            #line 2280 "Python/bytecodes.c"
             // On successful match, PUSH(values). Otherwise, PUSH(None).
             values_or_none = match_keys(tstate, subject, keys);
             if (values_or_none == NULL) goto error;
-            #line 3268 "Python/generated_cases.c.h"
+            #line 3269 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = values_or_none;
             DISPATCH();
@@ -3273,14 +3274,14 @@
         TARGET(GET_ITER) {
             PyObject *iterable = stack_pointer[-1];
             PyObject *iter;
-            #line 2285 "Python/bytecodes.c"
+            #line 2286 "Python/bytecodes.c"
             /* before: [obj]; after [getiter(obj)] */
             iter = PyObject_GetIter(iterable);
-            #line 3280 "Python/generated_cases.c.h"
+            #line 3281 "Python/generated_cases.c.h"
             Py_DECREF(iterable);
-            #line 2288 "Python/bytecodes.c"
+            #line 2289 "Python/bytecodes.c"
             if (iter == NULL) goto pop_1_error;
-            #line 3284 "Python/generated_cases.c.h"
+            #line 3285 "Python/generated_cases.c.h"
             stack_pointer[-1] = iter;
             DISPATCH();
         }
@@ -3288,7 +3289,7 @@
         TARGET(GET_YIELD_FROM_ITER) {
             PyObject *iterable = stack_pointer[-1];
             PyObject *iter;
-            #line 2292 "Python/bytecodes.c"
+            #line 2293 "Python/bytecodes.c"
             /* before: [obj]; after [getiter(obj)] */
             if (PyCoro_CheckExact(iterable)) {
                 /* `iterable` is a coroutine */
@@ -3311,11 +3312,11 @@
                 if (iter == NULL) {
                     goto error;
                 }
-            #line 3315 "Python/generated_cases.c.h"
+            #line 3316 "Python/generated_cases.c.h"
                 Py_DECREF(iterable);
-            #line 2315 "Python/bytecodes.c"
+            #line 2316 "Python/bytecodes.c"
             }
-            #line 3319 "Python/generated_cases.c.h"
+            #line 3320 "Python/generated_cases.c.h"
             stack_pointer[-1] = iter;
             DISPATCH();
         }
@@ -3325,7 +3326,7 @@
             static_assert(INLINE_CACHE_ENTRIES_FOR_ITER == 1, "incorrect cache size");
             PyObject *iter = stack_pointer[-1];
             PyObject *next;
-            #line 2333 "Python/bytecodes.c"
+            #line 2334 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             _PyForIterCache *cache = (_PyForIterCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
@@ -3357,7 +3358,7 @@
                 DISPATCH();
             }
             // Common case: no jump, leave it to the code generator
-            #line 3361 "Python/generated_cases.c.h"
+            #line 3362 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = next;
             next_instr += 1;
@@ -3365,7 +3366,7 @@
         }
 
         TARGET(INSTRUMENTED_FOR_ITER) {
-            #line 2367 "Python/bytecodes.c"
+            #line 2368 "Python/bytecodes.c"
             _Py_CODEUNIT *here = next_instr-1;
             _Py_CODEUNIT *target;
             PyObject *iter = TOP();
@@ -3391,14 +3392,14 @@
                 target = next_instr + INLINE_CACHE_ENTRIES_FOR_ITER + oparg + 1;
             }
             INSTRUMENTED_JUMP(here, target, PY_MONITORING_EVENT_BRANCH);
-            #line 3395 "Python/generated_cases.c.h"
+            #line 3396 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(FOR_ITER_LIST) {
             PyObject *iter = stack_pointer[-1];
             PyObject *next;
-            #line 2395 "Python/bytecodes.c"
+            #line 2396 "Python/bytecodes.c"
             DEOPT_IF(Py_TYPE(iter) != &PyListIter_Type, FOR_ITER);
             _PyListIterObject *it = (_PyListIterObject *)iter;
             STAT_INC(FOR_ITER, hit);
@@ -3419,7 +3420,7 @@
             DISPATCH();
         end_for_iter_list:
             // Common case: no jump, leave it to the code generator
-            #line 3423 "Python/generated_cases.c.h"
+            #line 3424 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = next;
             next_instr += 1;
@@ -3429,7 +3430,7 @@
         TARGET(FOR_ITER_TUPLE) {
             PyObject *iter = stack_pointer[-1];
             PyObject *next;
-            #line 2418 "Python/bytecodes.c"
+            #line 2419 "Python/bytecodes.c"
             _PyTupleIterObject *it = (_PyTupleIterObject *)iter;
             DEOPT_IF(Py_TYPE(it) != &PyTupleIter_Type, FOR_ITER);
             STAT_INC(FOR_ITER, hit);
@@ -3450,7 +3451,7 @@
             DISPATCH();
         end_for_iter_tuple:
             // Common case: no jump, leave it to the code generator
-            #line 3454 "Python/generated_cases.c.h"
+            #line 3455 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = next;
             next_instr += 1;
@@ -3460,7 +3461,7 @@
         TARGET(FOR_ITER_RANGE) {
             PyObject *iter = stack_pointer[-1];
             PyObject *next;
-            #line 2441 "Python/bytecodes.c"
+            #line 2442 "Python/bytecodes.c"
             _PyRangeIterObject *r = (_PyRangeIterObject *)iter;
             DEOPT_IF(Py_TYPE(r) != &PyRangeIter_Type, FOR_ITER);
             STAT_INC(FOR_ITER, hit);
@@ -3479,7 +3480,7 @@
             if (next == NULL) {
                 goto error;
             }
-            #line 3483 "Python/generated_cases.c.h"
+            #line 3484 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = next;
             next_instr += 1;
@@ -3488,7 +3489,7 @@
 
         TARGET(FOR_ITER_GEN) {
             PyObject *iter = stack_pointer[-1];
-            #line 2462 "Python/bytecodes.c"
+            #line 2463 "Python/bytecodes.c"
             DEOPT_IF(tstate->interp->eval_frame, FOR_ITER);
             PyGenObject *gen = (PyGenObject *)iter;
             DEOPT_IF(Py_TYPE(gen) != &PyGen_Type, FOR_ITER);
@@ -3504,14 +3505,14 @@
             assert(next_instr[oparg].op.code == END_FOR ||
                    next_instr[oparg].op.code == INSTRUMENTED_END_FOR);
             DISPATCH_INLINED(gen_frame);
-            #line 3508 "Python/generated_cases.c.h"
+            #line 3509 "Python/generated_cases.c.h"
         }
 
         TARGET(BEFORE_ASYNC_WITH) {
             PyObject *mgr = stack_pointer[-1];
             PyObject *exit;
             PyObject *res;
-            #line 2480 "Python/bytecodes.c"
+            #line 2481 "Python/bytecodes.c"
             PyObject *enter = _PyObject_LookupSpecial(mgr, &_Py_ID(__aenter__));
             if (enter == NULL) {
                 if (!_PyErr_Occurred(tstate)) {
@@ -3534,16 +3535,16 @@
                 Py_DECREF(enter);
                 goto error;
             }
-            #line 3538 "Python/generated_cases.c.h"
+            #line 3539 "Python/generated_cases.c.h"
             Py_DECREF(mgr);
-            #line 2503 "Python/bytecodes.c"
+            #line 2504 "Python/bytecodes.c"
             res = _PyObject_CallNoArgs(enter);
             Py_DECREF(enter);
             if (res == NULL) {
                 Py_DECREF(exit);
                 if (true) goto pop_1_error;
             }
-            #line 3547 "Python/generated_cases.c.h"
+            #line 3548 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             stack_pointer[-2] = exit;
@@ -3554,7 +3555,7 @@
             PyObject *mgr = stack_pointer[-1];
             PyObject *exit;
             PyObject *res;
-            #line 2512 "Python/bytecodes.c"
+            #line 2513 "Python/bytecodes.c"
             /* pop the context manager, push its __exit__ and the
              * value returned from calling its __enter__
              */
@@ -3580,16 +3581,16 @@
                 Py_DECREF(enter);
                 goto error;
             }
-            #line 3584 "Python/generated_cases.c.h"
+            #line 3585 "Python/generated_cases.c.h"
             Py_DECREF(mgr);
-            #line 2538 "Python/bytecodes.c"
+            #line 2539 "Python/bytecodes.c"
             res = _PyObject_CallNoArgs(enter);
             Py_DECREF(enter);
             if (res == NULL) {
                 Py_DECREF(exit);
                 if (true) goto pop_1_error;
             }
-            #line 3593 "Python/generated_cases.c.h"
+            #line 3594 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             stack_pointer[-2] = exit;
@@ -3601,7 +3602,7 @@
             PyObject *lasti = stack_pointer[-3];
             PyObject *exit_func = stack_pointer[-4];
             PyObject *res;
-            #line 2547 "Python/bytecodes.c"
+            #line 2548 "Python/bytecodes.c"
             /* At the top of the stack are 4 values:
                - val: TOP = exc_info()
                - unused: SECOND = previous exception
@@ -3622,7 +3623,7 @@
             res = PyObject_Vectorcall(exit_func, stack + 1,
                     3 | PY_VECTORCALL_ARGUMENTS_OFFSET, NULL);
             if (res == NULL) goto error;
-            #line 3626 "Python/generated_cases.c.h"
+            #line 3627 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             DISPATCH();
@@ -3631,7 +3632,7 @@
         TARGET(PUSH_EXC_INFO) {
             PyObject *new_exc = stack_pointer[-1];
             PyObject *prev_exc;
-            #line 2586 "Python/bytecodes.c"
+            #line 2587 "Python/bytecodes.c"
             _PyErr_StackItem *exc_info = tstate->exc_info;
             if (exc_info->exc_value != NULL) {
                 prev_exc = exc_info->exc_value;
@@ -3641,7 +3642,7 @@
             }
             assert(PyExceptionInstance_Check(new_exc));
             exc_info->exc_value = Py_NewRef(new_exc);
-            #line 3645 "Python/generated_cases.c.h"
+            #line 3646 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = new_exc;
             stack_pointer[-2] = prev_exc;
@@ -3655,7 +3656,7 @@
             uint32_t type_version = read_u32(&next_instr[1].cache);
             uint32_t keys_version = read_u32(&next_instr[3].cache);
             PyObject *descr = read_obj(&next_instr[5].cache);
-            #line 2598 "Python/bytecodes.c"
+            #line 2599 "Python/bytecodes.c"
             /* Cached method object */
             PyTypeObject *self_cls = Py_TYPE(self);
             assert(type_version != 0);
@@ -3672,7 +3673,7 @@
             assert(_PyType_HasFeature(Py_TYPE(res2), Py_TPFLAGS_METHOD_DESCRIPTOR));
             res = self;
             assert(oparg & 1);
-            #line 3676 "Python/generated_cases.c.h"
+            #line 3677 "Python/generated_cases.c.h"
             STACK_GROW(((oparg & 1) ? 1 : 0));
             stack_pointer[-1] = res;
             if (oparg & 1) { stack_pointer[-(1 + ((oparg & 1) ? 1 : 0))] = res2; }
@@ -3686,7 +3687,7 @@
             PyObject *res;
             uint32_t type_version = read_u32(&next_instr[1].cache);
             PyObject *descr = read_obj(&next_instr[5].cache);
-            #line 2617 "Python/bytecodes.c"
+            #line 2618 "Python/bytecodes.c"
             PyTypeObject *self_cls = Py_TYPE(self);
             DEOPT_IF(self_cls->tp_version_tag != type_version, LOAD_ATTR);
             assert(self_cls->tp_dictoffset == 0);
@@ -3696,7 +3697,7 @@
             res2 = Py_NewRef(descr);
             res = self;
             assert(oparg & 1);
-            #line 3700 "Python/generated_cases.c.h"
+            #line 3701 "Python/generated_cases.c.h"
             STACK_GROW(((oparg & 1) ? 1 : 0));
             stack_pointer[-1] = res;
             if (oparg & 1) { stack_pointer[-(1 + ((oparg & 1) ? 1 : 0))] = res2; }
@@ -3710,7 +3711,7 @@
             PyObject *res;
             uint32_t type_version = read_u32(&next_instr[1].cache);
             PyObject *descr = read_obj(&next_instr[5].cache);
-            #line 2629 "Python/bytecodes.c"
+            #line 2630 "Python/bytecodes.c"
             PyTypeObject *self_cls = Py_TYPE(self);
             DEOPT_IF(self_cls->tp_version_tag != type_version, LOAD_ATTR);
             Py_ssize_t dictoffset = self_cls->tp_dictoffset;
@@ -3724,7 +3725,7 @@
             res2 = Py_NewRef(descr);
             res = self;
             assert(oparg & 1);
-            #line 3728 "Python/generated_cases.c.h"
+            #line 3729 "Python/generated_cases.c.h"
             STACK_GROW(((oparg & 1) ? 1 : 0));
             stack_pointer[-1] = res;
             if (oparg & 1) { stack_pointer[-(1 + ((oparg & 1) ? 1 : 0))] = res2; }
@@ -3733,16 +3734,16 @@
         }
 
         TARGET(KW_NAMES) {
-            #line 2645 "Python/bytecodes.c"
+            #line 2646 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg < PyTuple_GET_SIZE(FRAME_CO_CONSTS));
             kwnames = GETITEM(FRAME_CO_CONSTS, oparg);
-            #line 3741 "Python/generated_cases.c.h"
+            #line 3742 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_CALL) {
-            #line 2651 "Python/bytecodes.c"
+            #line 2652 "Python/bytecodes.c"
             int is_meth = PEEK(oparg+2) != NULL;
             int total_args = oparg + is_meth;
             PyObject *function = PEEK(total_args + 1);
@@ -3755,7 +3756,7 @@
             _PyCallCache *cache = (_PyCallCache *)next_instr;
             INCREMENT_ADAPTIVE_COUNTER(cache->counter);
             GO_TO_INSTRUCTION(CALL);
-            #line 3759 "Python/generated_cases.c.h"
+            #line 3760 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL) {
@@ -3765,7 +3766,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2697 "Python/bytecodes.c"
+            #line 2698 "Python/bytecodes.c"
             int is_meth = method != NULL;
             int total_args = oparg;
             if (is_meth) {
@@ -3847,7 +3848,7 @@
                 Py_DECREF(args[i]);
             }
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 3851 "Python/generated_cases.c.h"
+            #line 3852 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -3859,7 +3860,7 @@
         TARGET(CALL_BOUND_METHOD_EXACT_ARGS) {
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
-            #line 2785 "Python/bytecodes.c"
+            #line 2786 "Python/bytecodes.c"
             DEOPT_IF(method != NULL, CALL);
             DEOPT_IF(Py_TYPE(callable) != &PyMethod_Type, CALL);
             STAT_INC(CALL, hit);
@@ -3869,7 +3870,7 @@
             PEEK(oparg + 2) = Py_NewRef(meth);  // method
             Py_DECREF(callable);
             GO_TO_INSTRUCTION(CALL_PY_EXACT_ARGS);
-            #line 3873 "Python/generated_cases.c.h"
+            #line 3874 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_PY_EXACT_ARGS) {
@@ -3878,7 +3879,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             uint32_t func_version = read_u32(&next_instr[1].cache);
-            #line 2797 "Python/bytecodes.c"
+            #line 2798 "Python/bytecodes.c"
             assert(kwnames == NULL);
             DEOPT_IF(tstate->interp->eval_frame, CALL);
             int is_meth = method != NULL;
@@ -3904,7 +3905,7 @@
             SKIP_OVER(INLINE_CACHE_ENTRIES_CALL);
             frame->return_offset = 0;
             DISPATCH_INLINED(new_frame);
-            #line 3908 "Python/generated_cases.c.h"
+            #line 3909 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_PY_WITH_DEFAULTS) {
@@ -3912,7 +3913,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             uint32_t func_version = read_u32(&next_instr[1].cache);
-            #line 2825 "Python/bytecodes.c"
+            #line 2826 "Python/bytecodes.c"
             assert(kwnames == NULL);
             DEOPT_IF(tstate->interp->eval_frame, CALL);
             int is_meth = method != NULL;
@@ -3948,7 +3949,7 @@
             SKIP_OVER(INLINE_CACHE_ENTRIES_CALL);
             frame->return_offset = 0;
             DISPATCH_INLINED(new_frame);
-            #line 3952 "Python/generated_cases.c.h"
+            #line 3953 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_NO_KW_TYPE_1) {
@@ -3956,7 +3957,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *null = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2863 "Python/bytecodes.c"
+            #line 2864 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 1);
             DEOPT_IF(null != NULL, CALL);
@@ -3966,7 +3967,7 @@
             res = Py_NewRef(Py_TYPE(obj));
             Py_DECREF(obj);
             Py_DECREF(&PyType_Type);  // I.e., callable
-            #line 3970 "Python/generated_cases.c.h"
+            #line 3971 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -3979,7 +3980,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *null = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2875 "Python/bytecodes.c"
+            #line 2876 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 1);
             DEOPT_IF(null != NULL, CALL);
@@ -3990,7 +3991,7 @@
             Py_DECREF(arg);
             Py_DECREF(&PyUnicode_Type);  // I.e., callable
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 3994 "Python/generated_cases.c.h"
+            #line 3995 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4004,7 +4005,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *null = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2889 "Python/bytecodes.c"
+            #line 2890 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 1);
             DEOPT_IF(null != NULL, CALL);
@@ -4015,7 +4016,7 @@
             Py_DECREF(arg);
             Py_DECREF(&PyTuple_Type);  // I.e., tuple
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4019 "Python/generated_cases.c.h"
+            #line 4020 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4028,7 +4029,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *null = stack_pointer[-(2 + oparg)];
-            #line 2903 "Python/bytecodes.c"
+            #line 2904 "Python/bytecodes.c"
             /* This instruction does the following:
              * 1. Creates the object (by calling ``object.__new__``)
              * 2. Pushes a shim frame to the frame stack (to cleanup after ``__init__``)
@@ -4078,12 +4079,12 @@
             frame = cframe.current_frame = init_frame;
             CALL_STAT_INC(inlined_py_calls);
             goto start_frame;
-            #line 4082 "Python/generated_cases.c.h"
+            #line 4083 "Python/generated_cases.c.h"
         }
 
         TARGET(EXIT_INIT_CHECK) {
             PyObject *should_be_none = stack_pointer[-1];
-            #line 2955 "Python/bytecodes.c"
+            #line 2956 "Python/bytecodes.c"
             assert(STACK_LEVEL() == 2);
             if (should_be_none != Py_None) {
                 PyErr_Format(PyExc_TypeError,
@@ -4091,7 +4092,7 @@
                     Py_TYPE(should_be_none)->tp_name);
                 goto error;
             }
-            #line 4095 "Python/generated_cases.c.h"
+            #line 4096 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
@@ -4101,7 +4102,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2965 "Python/bytecodes.c"
+            #line 2966 "Python/bytecodes.c"
             int is_meth = method != NULL;
             int total_args = oparg;
             if (is_meth) {
@@ -4123,7 +4124,7 @@
             }
             Py_DECREF(tp);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4127 "Python/generated_cases.c.h"
+            #line 4128 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4137,7 +4138,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2990 "Python/bytecodes.c"
+            #line 2991 "Python/bytecodes.c"
             /* Builtin METH_O functions */
             assert(kwnames == NULL);
             int is_meth = method != NULL;
@@ -4165,7 +4166,7 @@
             Py_DECREF(arg);
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4169 "Python/generated_cases.c.h"
+            #line 4170 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4179,7 +4180,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3021 "Python/bytecodes.c"
+            #line 3022 "Python/bytecodes.c"
             /* Builtin METH_FASTCALL functions, without keywords */
             assert(kwnames == NULL);
             int is_meth = method != NULL;
@@ -4211,7 +4212,7 @@
                    'invalid'). In those cases an exception is set, so we must
                    handle it.
                 */
-            #line 4215 "Python/generated_cases.c.h"
+            #line 4216 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4225,7 +4226,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3056 "Python/bytecodes.c"
+            #line 3057 "Python/bytecodes.c"
             /* Builtin METH_FASTCALL | METH_KEYWORDS functions */
             int is_meth = method != NULL;
             int total_args = oparg;
@@ -4257,7 +4258,7 @@
             }
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4261 "Python/generated_cases.c.h"
+            #line 4262 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4271,7 +4272,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3091 "Python/bytecodes.c"
+            #line 3092 "Python/bytecodes.c"
             assert(kwnames == NULL);
             /* len(o) */
             int is_meth = method != NULL;
@@ -4296,7 +4297,7 @@
             Py_DECREF(callable);
             Py_DECREF(arg);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4300 "Python/generated_cases.c.h"
+            #line 4301 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4309,7 +4310,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3118 "Python/bytecodes.c"
+            #line 3119 "Python/bytecodes.c"
             assert(kwnames == NULL);
             /* isinstance(o, o2) */
             int is_meth = method != NULL;
@@ -4336,7 +4337,7 @@
             Py_DECREF(cls);
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4340 "Python/generated_cases.c.h"
+            #line 4341 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4348,7 +4349,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *self = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
-            #line 3148 "Python/bytecodes.c"
+            #line 3149 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 1);
             assert(method != NULL);
@@ -4366,14 +4367,14 @@
             SKIP_OVER(INLINE_CACHE_ENTRIES_CALL + 1);
             assert(next_instr[-1].op.code == POP_TOP);
             DISPATCH();
-            #line 4370 "Python/generated_cases.c.h"
+            #line 4371 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_NO_KW_METHOD_DESCRIPTOR_O) {
             PyObject **args = (stack_pointer - oparg);
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3168 "Python/bytecodes.c"
+            #line 3169 "Python/bytecodes.c"
             assert(kwnames == NULL);
             int is_meth = method != NULL;
             int total_args = oparg;
@@ -4404,7 +4405,7 @@
             Py_DECREF(arg);
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4408 "Python/generated_cases.c.h"
+            #line 4409 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4417,7 +4418,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3202 "Python/bytecodes.c"
+            #line 3203 "Python/bytecodes.c"
             int is_meth = method != NULL;
             int total_args = oparg;
             if (is_meth) {
@@ -4446,7 +4447,7 @@
             }
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4450 "Python/generated_cases.c.h"
+            #line 4451 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4459,7 +4460,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3234 "Python/bytecodes.c"
+            #line 3235 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 0 || oparg == 1);
             int is_meth = method != NULL;
@@ -4488,7 +4489,7 @@
             Py_DECREF(self);
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4492 "Python/generated_cases.c.h"
+            #line 4493 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4501,7 +4502,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3266 "Python/bytecodes.c"
+            #line 3267 "Python/bytecodes.c"
             assert(kwnames == NULL);
             int is_meth = method != NULL;
             int total_args = oparg;
@@ -4529,7 +4530,7 @@
             }
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4533 "Python/generated_cases.c.h"
+            #line 4534 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4539,9 +4540,9 @@
         }
 
         TARGET(INSTRUMENTED_CALL_FUNCTION_EX) {
-            #line 3297 "Python/bytecodes.c"
+            #line 3298 "Python/bytecodes.c"
             GO_TO_INSTRUCTION(CALL_FUNCTION_EX);
-            #line 4545 "Python/generated_cases.c.h"
+            #line 4546 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_FUNCTION_EX) {
@@ -4550,7 +4551,7 @@
             PyObject *callargs = stack_pointer[-(1 + ((oparg & 1) ? 1 : 0))];
             PyObject *func = stack_pointer[-(2 + ((oparg & 1) ? 1 : 0))];
             PyObject *result;
-            #line 3301 "Python/bytecodes.c"
+            #line 3302 "Python/bytecodes.c"
             // DICT_MERGE is called before this opcode if there are kwargs.
             // It converts all dict subtypes in kwargs into regular dicts.
             assert(kwargs == NULL || PyDict_CheckExact(kwargs));
@@ -4612,14 +4613,14 @@
                 }
                 result = PyObject_Call(func, callargs, kwargs);
             }
-            #line 4616 "Python/generated_cases.c.h"
+            #line 4617 "Python/generated_cases.c.h"
             Py_DECREF(func);
             Py_DECREF(callargs);
             Py_XDECREF(kwargs);
-            #line 3363 "Python/bytecodes.c"
+            #line 3364 "Python/bytecodes.c"
             assert(PEEK(3 + (oparg & 1)) == NULL);
             if (result == NULL) { STACK_SHRINK(((oparg & 1) ? 1 : 0)); goto pop_3_error; }
-            #line 4623 "Python/generated_cases.c.h"
+            #line 4624 "Python/generated_cases.c.h"
             STACK_SHRINK(((oparg & 1) ? 1 : 0));
             STACK_SHRINK(2);
             stack_pointer[-1] = result;
@@ -4630,7 +4631,7 @@
         TARGET(MAKE_FUNCTION) {
             PyObject *codeobj = stack_pointer[-1];
             PyObject *func;
-            #line 3369 "Python/bytecodes.c"
+            #line 3370 "Python/bytecodes.c"
 
             PyFunctionObject *func_obj = (PyFunctionObject *)
                 PyFunction_New(codeobj, GLOBALS());
@@ -4642,7 +4643,7 @@
 
             func_obj->func_version = ((PyCodeObject *)codeobj)->co_version;
             func = (PyObject *)func_obj;
-            #line 4646 "Python/generated_cases.c.h"
+            #line 4647 "Python/generated_cases.c.h"
             stack_pointer[-1] = func;
             DISPATCH();
         }
@@ -4650,7 +4651,7 @@
         TARGET(SET_FUNCTION_ATTRIBUTE) {
             PyObject *func = stack_pointer[-1];
             PyObject *attr = stack_pointer[-2];
-            #line 3383 "Python/bytecodes.c"
+            #line 3384 "Python/bytecodes.c"
             assert(PyFunction_Check(func));
             PyFunctionObject *func_obj = (PyFunctionObject *)func;
             switch(oparg) {
@@ -4675,14 +4676,14 @@
                 default:
                     Py_UNREACHABLE();
             }
-            #line 4679 "Python/generated_cases.c.h"
+            #line 4680 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             stack_pointer[-1] = func;
             DISPATCH();
         }
 
         TARGET(RETURN_GENERATOR) {
-            #line 3410 "Python/bytecodes.c"
+            #line 3411 "Python/bytecodes.c"
             assert(PyFunction_Check(frame->f_funcobj));
             PyFunctionObject *func = (PyFunctionObject *)frame->f_funcobj;
             PyGenObject *gen = (PyGenObject *)_Py_MakeCoro(func);
@@ -4703,7 +4704,7 @@
             frame = cframe.current_frame = prev;
             _PyFrame_StackPush(frame, (PyObject *)gen);
             goto resume_frame;
-            #line 4707 "Python/generated_cases.c.h"
+            #line 4708 "Python/generated_cases.c.h"
         }
 
         TARGET(BUILD_SLICE) {
@@ -4711,15 +4712,15 @@
             PyObject *stop = stack_pointer[-(1 + ((oparg == 3) ? 1 : 0))];
             PyObject *start = stack_pointer[-(2 + ((oparg == 3) ? 1 : 0))];
             PyObject *slice;
-            #line 3433 "Python/bytecodes.c"
+            #line 3434 "Python/bytecodes.c"
             slice = PySlice_New(start, stop, step);
-            #line 4717 "Python/generated_cases.c.h"
+            #line 4718 "Python/generated_cases.c.h"
             Py_DECREF(start);
             Py_DECREF(stop);
             Py_XDECREF(step);
-            #line 3435 "Python/bytecodes.c"
+            #line 3436 "Python/bytecodes.c"
             if (slice == NULL) { STACK_SHRINK(((oparg == 3) ? 1 : 0)); goto pop_2_error; }
-            #line 4723 "Python/generated_cases.c.h"
+            #line 4724 "Python/generated_cases.c.h"
             STACK_SHRINK(((oparg == 3) ? 1 : 0));
             STACK_SHRINK(1);
             stack_pointer[-1] = slice;
@@ -4729,14 +4730,14 @@
         TARGET(CONVERT_VALUE) {
             PyObject *value = stack_pointer[-1];
             PyObject *result;
-            #line 3439 "Python/bytecodes.c"
+            #line 3440 "Python/bytecodes.c"
             convertion_func_ptr  conv_fn;
             assert(oparg >= FVC_STR && oparg <= FVC_ASCII);
             conv_fn = CONVERSION_FUNCTIONS[oparg];
             result = conv_fn(value);
             Py_DECREF(value);
             if (result == NULL) goto pop_1_error;
-            #line 4740 "Python/generated_cases.c.h"
+            #line 4741 "Python/generated_cases.c.h"
             stack_pointer[-1] = result;
             DISPATCH();
         }
@@ -4744,7 +4745,7 @@
         TARGET(FORMAT_SIMPLE) {
             PyObject *value = stack_pointer[-1];
             PyObject *res;
-            #line 3448 "Python/bytecodes.c"
+            #line 3449 "Python/bytecodes.c"
             /* If value is a unicode object, then we know the result
              * of format(value) is value itself. */
             if (!PyUnicode_CheckExact(value)) {
@@ -4755,7 +4756,7 @@
             else {
                 res = value;
             }
-            #line 4759 "Python/generated_cases.c.h"
+            #line 4760 "Python/generated_cases.c.h"
             stack_pointer[-1] = res;
             DISPATCH();
         }
@@ -4764,12 +4765,12 @@
             PyObject *fmt_spec = stack_pointer[-1];
             PyObject *value = stack_pointer[-2];
             PyObject *res;
-            #line 3461 "Python/bytecodes.c"
+            #line 3462 "Python/bytecodes.c"
             res = PyObject_Format(value, fmt_spec);
             Py_DECREF(value);
             Py_DECREF(fmt_spec);
             if (res == NULL) goto pop_2_error;
-            #line 4773 "Python/generated_cases.c.h"
+            #line 4774 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
             DISPATCH();
@@ -4778,10 +4779,10 @@
         TARGET(COPY) {
             PyObject *bottom = stack_pointer[-(1 + (oparg-1))];
             PyObject *top;
-            #line 3468 "Python/bytecodes.c"
+            #line 3469 "Python/bytecodes.c"
             assert(oparg > 0);
             top = Py_NewRef(bottom);
-            #line 4785 "Python/generated_cases.c.h"
+            #line 4786 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = top;
             DISPATCH();
@@ -4793,7 +4794,7 @@
             PyObject *rhs = stack_pointer[-1];
             PyObject *lhs = stack_pointer[-2];
             PyObject *res;
-            #line 3473 "Python/bytecodes.c"
+            #line 3474 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             _PyBinaryOpCache *cache = (_PyBinaryOpCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
@@ -4808,12 +4809,12 @@
             assert((unsigned)oparg < Py_ARRAY_LENGTH(binary_ops));
             assert(binary_ops[oparg]);
             res = binary_ops[oparg](lhs, rhs);
-            #line 4812 "Python/generated_cases.c.h"
+            #line 4813 "Python/generated_cases.c.h"
             Py_DECREF(lhs);
             Py_DECREF(rhs);
-            #line 3488 "Python/bytecodes.c"
+            #line 3489 "Python/bytecodes.c"
             if (res == NULL) goto pop_2_error;
-            #line 4817 "Python/generated_cases.c.h"
+            #line 4818 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
             next_instr += 1;
@@ -4823,16 +4824,16 @@
         TARGET(SWAP) {
             PyObject *top = stack_pointer[-1];
             PyObject *bottom = stack_pointer[-(2 + (oparg-2))];
-            #line 3493 "Python/bytecodes.c"
+            #line 3494 "Python/bytecodes.c"
             assert(oparg >= 2);
-            #line 4829 "Python/generated_cases.c.h"
+            #line 4830 "Python/generated_cases.c.h"
             stack_pointer[-1] = bottom;
             stack_pointer[-(2 + (oparg-2))] = top;
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_INSTRUCTION) {
-            #line 3497 "Python/bytecodes.c"
+            #line 3498 "Python/bytecodes.c"
             int next_opcode = _Py_call_instrumentation_instruction(
                 tstate, frame, next_instr-1);
             if (next_opcode < 0) goto error;
@@ -4844,26 +4845,26 @@
             assert(next_opcode > 0 && next_opcode < 256);
             opcode = next_opcode;
             DISPATCH_GOTO();
-            #line 4848 "Python/generated_cases.c.h"
+            #line 4849 "Python/generated_cases.c.h"
         }
 
         TARGET(INSTRUMENTED_JUMP_FORWARD) {
-            #line 3511 "Python/bytecodes.c"
+            #line 3512 "Python/bytecodes.c"
             INSTRUMENTED_JUMP(next_instr-1, next_instr+oparg, PY_MONITORING_EVENT_JUMP);
-            #line 4854 "Python/generated_cases.c.h"
+            #line 4855 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_JUMP_BACKWARD) {
-            #line 3515 "Python/bytecodes.c"
-            INSTRUMENTED_JUMP(next_instr-1, next_instr+1-oparg, PY_MONITORING_EVENT_JUMP);
-            #line 4861 "Python/generated_cases.c.h"
+            #line 3516 "Python/bytecodes.c"
             CHECK_EVAL_BREAKER();
+            INSTRUMENTED_JUMP(next_instr-1, next_instr+1-oparg, PY_MONITORING_EVENT_JUMP);
+            #line 4863 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_POP_JUMP_IF_TRUE) {
-            #line 3520 "Python/bytecodes.c"
+            #line 3521 "Python/bytecodes.c"
             PyObject *cond = POP();
             int err = PyObject_IsTrue(cond);
             Py_DECREF(cond);
@@ -4872,12 +4873,12 @@
             assert(err == 0 || err == 1);
             int offset = err*oparg;
             INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
-            #line 4876 "Python/generated_cases.c.h"
+            #line 4877 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_POP_JUMP_IF_FALSE) {
-            #line 3531 "Python/bytecodes.c"
+            #line 3532 "Python/bytecodes.c"
             PyObject *cond = POP();
             int err = PyObject_IsTrue(cond);
             Py_DECREF(cond);
@@ -4886,12 +4887,12 @@
             assert(err == 0 || err == 1);
             int offset = (1-err)*oparg;
             INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
-            #line 4890 "Python/generated_cases.c.h"
+            #line 4891 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_POP_JUMP_IF_NONE) {
-            #line 3542 "Python/bytecodes.c"
+            #line 3543 "Python/bytecodes.c"
             PyObject *value = POP();
             _Py_CODEUNIT *here = next_instr-1;
             int offset;
@@ -4903,12 +4904,12 @@
                 offset = 0;
             }
             INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
-            #line 4907 "Python/generated_cases.c.h"
+            #line 4908 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_POP_JUMP_IF_NOT_NONE) {
-            #line 3556 "Python/bytecodes.c"
+            #line 3557 "Python/bytecodes.c"
             PyObject *value = POP();
             _Py_CODEUNIT *here = next_instr-1;
             int offset;
@@ -4920,30 +4921,30 @@
                  offset = oparg;
             }
             INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
-            #line 4924 "Python/generated_cases.c.h"
+            #line 4925 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(EXTENDED_ARG) {
-            #line 3570 "Python/bytecodes.c"
+            #line 3571 "Python/bytecodes.c"
             assert(oparg);
             opcode = next_instr->op.code;
             oparg = oparg << 8 | next_instr->op.arg;
             PRE_DISPATCH_GOTO();
             DISPATCH_GOTO();
-            #line 4935 "Python/generated_cases.c.h"
+            #line 4936 "Python/generated_cases.c.h"
         }
 
         TARGET(CACHE) {
-            #line 3578 "Python/bytecodes.c"
+            #line 3579 "Python/bytecodes.c"
             assert(0 && "Executing a cache.");
             Py_UNREACHABLE();
-            #line 4942 "Python/generated_cases.c.h"
+            #line 4943 "Python/generated_cases.c.h"
         }
 
         TARGET(RESERVED) {
-            #line 3583 "Python/bytecodes.c"
+            #line 3584 "Python/bytecodes.c"
             assert(0 && "Executing RESERVED instruction.");
             Py_UNREACHABLE();
-            #line 4949 "Python/generated_cases.c.h"
+            #line 4950 "Python/generated_cases.c.h"
         }

From f2cf146451a6a4cd0e3e846286b1451d13b67ecb Mon Sep 17 00:00:00 2001
From: Mark Shannon <mark@hotpy.org>
Date: Wed, 21 Jun 2023 06:51:10 +0100
Subject: [PATCH 2/4] Make sure that frame->prev_instr is set before entering
 executor.

---
 Python/bytecodes.c         |   2 +
 Python/generated_cases.c.h | 328 +++++++++++++++++++------------------
 Python/opcode_metadata.h   |   2 +-
 3 files changed, 168 insertions(+), 164 deletions(-)

diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index c34dc568b646ed..7eb4cd66da8146 100644
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -2175,6 +2175,8 @@ dummy_func(
 
         inst(ENTER_EXECUTOR, (--)) {
             CHECK_EVAL_BREAKER();
+            JUMPBY(1-oparg);
+            frame->prev_instr = next_instr - 1;
             PyCodeObject *code = _PyFrame_GetCode(frame);
             _PyExecutorObject *executor = (_PyExecutorObject *)code->co_executors->executors[oparg&255];
             Py_INCREF(executor);
diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
index 6005b153c1b631..528ff19dc95064 100644
--- a/Python/generated_cases.c.h
+++ b/Python/generated_cases.c.h
@@ -3090,6 +3090,8 @@
         TARGET(ENTER_EXECUTOR) {
             #line 2177 "Python/bytecodes.c"
             CHECK_EVAL_BREAKER();
+            JUMPBY(1-oparg);
+            frame->prev_instr = next_instr - 1;
             PyCodeObject *code = _PyFrame_GetCode(frame);
             _PyExecutorObject *executor = (_PyExecutorObject *)code->co_executors->executors[oparg&255];
             Py_INCREF(executor);
@@ -3099,20 +3101,20 @@
                 goto resume_with_error;
             }
             goto resume_frame;
-            #line 3103 "Python/generated_cases.c.h"
+            #line 3105 "Python/generated_cases.c.h"
         }
 
         TARGET(POP_JUMP_IF_FALSE) {
             PyObject *cond = stack_pointer[-1];
-            #line 2190 "Python/bytecodes.c"
+            #line 2192 "Python/bytecodes.c"
             if (Py_IsFalse(cond)) {
                 JUMPBY(oparg);
             }
             else if (!Py_IsTrue(cond)) {
                 int err = PyObject_IsTrue(cond);
-            #line 3114 "Python/generated_cases.c.h"
+            #line 3116 "Python/generated_cases.c.h"
                 Py_DECREF(cond);
-            #line 2196 "Python/bytecodes.c"
+            #line 2198 "Python/bytecodes.c"
                 if (err == 0) {
                     JUMPBY(oparg);
                 }
@@ -3120,22 +3122,22 @@
                     if (err < 0) goto pop_1_error;
                 }
             }
-            #line 3124 "Python/generated_cases.c.h"
+            #line 3126 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
 
         TARGET(POP_JUMP_IF_TRUE) {
             PyObject *cond = stack_pointer[-1];
-            #line 2206 "Python/bytecodes.c"
+            #line 2208 "Python/bytecodes.c"
             if (Py_IsTrue(cond)) {
                 JUMPBY(oparg);
             }
             else if (!Py_IsFalse(cond)) {
                 int err = PyObject_IsTrue(cond);
-            #line 3137 "Python/generated_cases.c.h"
+            #line 3139 "Python/generated_cases.c.h"
                 Py_DECREF(cond);
-            #line 2212 "Python/bytecodes.c"
+            #line 2214 "Python/bytecodes.c"
                 if (err > 0) {
                     JUMPBY(oparg);
                 }
@@ -3143,63 +3145,63 @@
                     if (err < 0) goto pop_1_error;
                 }
             }
-            #line 3147 "Python/generated_cases.c.h"
+            #line 3149 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
 
         TARGET(POP_JUMP_IF_NOT_NONE) {
             PyObject *value = stack_pointer[-1];
-            #line 2222 "Python/bytecodes.c"
+            #line 2224 "Python/bytecodes.c"
             if (!Py_IsNone(value)) {
-            #line 3156 "Python/generated_cases.c.h"
+            #line 3158 "Python/generated_cases.c.h"
                 Py_DECREF(value);
-            #line 2224 "Python/bytecodes.c"
+            #line 2226 "Python/bytecodes.c"
                 JUMPBY(oparg);
             }
-            #line 3161 "Python/generated_cases.c.h"
+            #line 3163 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
 
         TARGET(POP_JUMP_IF_NONE) {
             PyObject *value = stack_pointer[-1];
-            #line 2229 "Python/bytecodes.c"
+            #line 2231 "Python/bytecodes.c"
             if (Py_IsNone(value)) {
                 JUMPBY(oparg);
             }
             else {
-            #line 3173 "Python/generated_cases.c.h"
+            #line 3175 "Python/generated_cases.c.h"
                 Py_DECREF(value);
-            #line 2234 "Python/bytecodes.c"
+            #line 2236 "Python/bytecodes.c"
             }
-            #line 3177 "Python/generated_cases.c.h"
+            #line 3179 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
 
         TARGET(JUMP_BACKWARD_NO_INTERRUPT) {
-            #line 2238 "Python/bytecodes.c"
+            #line 2240 "Python/bytecodes.c"
             /* This bytecode is used in the `yield from` or `await` loop.
              * If there is an interrupt, we want it handled in the innermost
              * generator or coroutine, so we deliberately do not check it here.
              * (see bpo-30039).
              */
             JUMPBY(-oparg);
-            #line 3190 "Python/generated_cases.c.h"
+            #line 3192 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(GET_LEN) {
             PyObject *obj = stack_pointer[-1];
             PyObject *len_o;
-            #line 2247 "Python/bytecodes.c"
+            #line 2249 "Python/bytecodes.c"
             // PUSH(len(TOS))
             Py_ssize_t len_i = PyObject_Length(obj);
             if (len_i < 0) goto error;
             len_o = PyLong_FromSsize_t(len_i);
             if (len_o == NULL) goto error;
-            #line 3203 "Python/generated_cases.c.h"
+            #line 3205 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = len_o;
             DISPATCH();
@@ -3210,16 +3212,16 @@
             PyObject *type = stack_pointer[-2];
             PyObject *subject = stack_pointer[-3];
             PyObject *attrs;
-            #line 2255 "Python/bytecodes.c"
+            #line 2257 "Python/bytecodes.c"
             // Pop TOS and TOS1. Set TOS to a tuple of attributes on success, or
             // None on failure.
             assert(PyTuple_CheckExact(names));
             attrs = match_class(tstate, subject, type, oparg, names);
-            #line 3219 "Python/generated_cases.c.h"
+            #line 3221 "Python/generated_cases.c.h"
             Py_DECREF(subject);
             Py_DECREF(type);
             Py_DECREF(names);
-            #line 2260 "Python/bytecodes.c"
+            #line 2262 "Python/bytecodes.c"
             if (attrs) {
                 assert(PyTuple_CheckExact(attrs));  // Success!
             }
@@ -3227,7 +3229,7 @@
                 if (_PyErr_Occurred(tstate)) goto pop_3_error;
                 attrs = Py_None;  // Failure!
             }
-            #line 3231 "Python/generated_cases.c.h"
+            #line 3233 "Python/generated_cases.c.h"
             STACK_SHRINK(2);
             stack_pointer[-1] = attrs;
             DISPATCH();
@@ -3236,10 +3238,10 @@
         TARGET(MATCH_MAPPING) {
             PyObject *subject = stack_pointer[-1];
             PyObject *res;
-            #line 2270 "Python/bytecodes.c"
+            #line 2272 "Python/bytecodes.c"
             int match = Py_TYPE(subject)->tp_flags & Py_TPFLAGS_MAPPING;
             res = match ? Py_True : Py_False;
-            #line 3243 "Python/generated_cases.c.h"
+            #line 3245 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             DISPATCH();
@@ -3248,10 +3250,10 @@
         TARGET(MATCH_SEQUENCE) {
             PyObject *subject = stack_pointer[-1];
             PyObject *res;
-            #line 2275 "Python/bytecodes.c"
+            #line 2277 "Python/bytecodes.c"
             int match = Py_TYPE(subject)->tp_flags & Py_TPFLAGS_SEQUENCE;
             res = match ? Py_True : Py_False;
-            #line 3255 "Python/generated_cases.c.h"
+            #line 3257 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             DISPATCH();
@@ -3261,11 +3263,11 @@
             PyObject *keys = stack_pointer[-1];
             PyObject *subject = stack_pointer[-2];
             PyObject *values_or_none;
-            #line 2280 "Python/bytecodes.c"
+            #line 2282 "Python/bytecodes.c"
             // On successful match, PUSH(values). Otherwise, PUSH(None).
             values_or_none = match_keys(tstate, subject, keys);
             if (values_or_none == NULL) goto error;
-            #line 3269 "Python/generated_cases.c.h"
+            #line 3271 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = values_or_none;
             DISPATCH();
@@ -3274,14 +3276,14 @@
         TARGET(GET_ITER) {
             PyObject *iterable = stack_pointer[-1];
             PyObject *iter;
-            #line 2286 "Python/bytecodes.c"
+            #line 2288 "Python/bytecodes.c"
             /* before: [obj]; after [getiter(obj)] */
             iter = PyObject_GetIter(iterable);
-            #line 3281 "Python/generated_cases.c.h"
+            #line 3283 "Python/generated_cases.c.h"
             Py_DECREF(iterable);
-            #line 2289 "Python/bytecodes.c"
+            #line 2291 "Python/bytecodes.c"
             if (iter == NULL) goto pop_1_error;
-            #line 3285 "Python/generated_cases.c.h"
+            #line 3287 "Python/generated_cases.c.h"
             stack_pointer[-1] = iter;
             DISPATCH();
         }
@@ -3289,7 +3291,7 @@
         TARGET(GET_YIELD_FROM_ITER) {
             PyObject *iterable = stack_pointer[-1];
             PyObject *iter;
-            #line 2293 "Python/bytecodes.c"
+            #line 2295 "Python/bytecodes.c"
             /* before: [obj]; after [getiter(obj)] */
             if (PyCoro_CheckExact(iterable)) {
                 /* `iterable` is a coroutine */
@@ -3312,11 +3314,11 @@
                 if (iter == NULL) {
                     goto error;
                 }
-            #line 3316 "Python/generated_cases.c.h"
+            #line 3318 "Python/generated_cases.c.h"
                 Py_DECREF(iterable);
-            #line 2316 "Python/bytecodes.c"
+            #line 2318 "Python/bytecodes.c"
             }
-            #line 3320 "Python/generated_cases.c.h"
+            #line 3322 "Python/generated_cases.c.h"
             stack_pointer[-1] = iter;
             DISPATCH();
         }
@@ -3326,7 +3328,7 @@
             static_assert(INLINE_CACHE_ENTRIES_FOR_ITER == 1, "incorrect cache size");
             PyObject *iter = stack_pointer[-1];
             PyObject *next;
-            #line 2334 "Python/bytecodes.c"
+            #line 2336 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             _PyForIterCache *cache = (_PyForIterCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
@@ -3358,7 +3360,7 @@
                 DISPATCH();
             }
             // Common case: no jump, leave it to the code generator
-            #line 3362 "Python/generated_cases.c.h"
+            #line 3364 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = next;
             next_instr += 1;
@@ -3366,7 +3368,7 @@
         }
 
         TARGET(INSTRUMENTED_FOR_ITER) {
-            #line 2368 "Python/bytecodes.c"
+            #line 2370 "Python/bytecodes.c"
             _Py_CODEUNIT *here = next_instr-1;
             _Py_CODEUNIT *target;
             PyObject *iter = TOP();
@@ -3392,14 +3394,14 @@
                 target = next_instr + INLINE_CACHE_ENTRIES_FOR_ITER + oparg + 1;
             }
             INSTRUMENTED_JUMP(here, target, PY_MONITORING_EVENT_BRANCH);
-            #line 3396 "Python/generated_cases.c.h"
+            #line 3398 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(FOR_ITER_LIST) {
             PyObject *iter = stack_pointer[-1];
             PyObject *next;
-            #line 2396 "Python/bytecodes.c"
+            #line 2398 "Python/bytecodes.c"
             DEOPT_IF(Py_TYPE(iter) != &PyListIter_Type, FOR_ITER);
             _PyListIterObject *it = (_PyListIterObject *)iter;
             STAT_INC(FOR_ITER, hit);
@@ -3420,7 +3422,7 @@
             DISPATCH();
         end_for_iter_list:
             // Common case: no jump, leave it to the code generator
-            #line 3424 "Python/generated_cases.c.h"
+            #line 3426 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = next;
             next_instr += 1;
@@ -3430,7 +3432,7 @@
         TARGET(FOR_ITER_TUPLE) {
             PyObject *iter = stack_pointer[-1];
             PyObject *next;
-            #line 2419 "Python/bytecodes.c"
+            #line 2421 "Python/bytecodes.c"
             _PyTupleIterObject *it = (_PyTupleIterObject *)iter;
             DEOPT_IF(Py_TYPE(it) != &PyTupleIter_Type, FOR_ITER);
             STAT_INC(FOR_ITER, hit);
@@ -3451,7 +3453,7 @@
             DISPATCH();
         end_for_iter_tuple:
             // Common case: no jump, leave it to the code generator
-            #line 3455 "Python/generated_cases.c.h"
+            #line 3457 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = next;
             next_instr += 1;
@@ -3461,7 +3463,7 @@
         TARGET(FOR_ITER_RANGE) {
             PyObject *iter = stack_pointer[-1];
             PyObject *next;
-            #line 2442 "Python/bytecodes.c"
+            #line 2444 "Python/bytecodes.c"
             _PyRangeIterObject *r = (_PyRangeIterObject *)iter;
             DEOPT_IF(Py_TYPE(r) != &PyRangeIter_Type, FOR_ITER);
             STAT_INC(FOR_ITER, hit);
@@ -3480,7 +3482,7 @@
             if (next == NULL) {
                 goto error;
             }
-            #line 3484 "Python/generated_cases.c.h"
+            #line 3486 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = next;
             next_instr += 1;
@@ -3489,7 +3491,7 @@
 
         TARGET(FOR_ITER_GEN) {
             PyObject *iter = stack_pointer[-1];
-            #line 2463 "Python/bytecodes.c"
+            #line 2465 "Python/bytecodes.c"
             DEOPT_IF(tstate->interp->eval_frame, FOR_ITER);
             PyGenObject *gen = (PyGenObject *)iter;
             DEOPT_IF(Py_TYPE(gen) != &PyGen_Type, FOR_ITER);
@@ -3505,14 +3507,14 @@
             assert(next_instr[oparg].op.code == END_FOR ||
                    next_instr[oparg].op.code == INSTRUMENTED_END_FOR);
             DISPATCH_INLINED(gen_frame);
-            #line 3509 "Python/generated_cases.c.h"
+            #line 3511 "Python/generated_cases.c.h"
         }
 
         TARGET(BEFORE_ASYNC_WITH) {
             PyObject *mgr = stack_pointer[-1];
             PyObject *exit;
             PyObject *res;
-            #line 2481 "Python/bytecodes.c"
+            #line 2483 "Python/bytecodes.c"
             PyObject *enter = _PyObject_LookupSpecial(mgr, &_Py_ID(__aenter__));
             if (enter == NULL) {
                 if (!_PyErr_Occurred(tstate)) {
@@ -3535,16 +3537,16 @@
                 Py_DECREF(enter);
                 goto error;
             }
-            #line 3539 "Python/generated_cases.c.h"
+            #line 3541 "Python/generated_cases.c.h"
             Py_DECREF(mgr);
-            #line 2504 "Python/bytecodes.c"
+            #line 2506 "Python/bytecodes.c"
             res = _PyObject_CallNoArgs(enter);
             Py_DECREF(enter);
             if (res == NULL) {
                 Py_DECREF(exit);
                 if (true) goto pop_1_error;
             }
-            #line 3548 "Python/generated_cases.c.h"
+            #line 3550 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             stack_pointer[-2] = exit;
@@ -3555,7 +3557,7 @@
             PyObject *mgr = stack_pointer[-1];
             PyObject *exit;
             PyObject *res;
-            #line 2513 "Python/bytecodes.c"
+            #line 2515 "Python/bytecodes.c"
             /* pop the context manager, push its __exit__ and the
              * value returned from calling its __enter__
              */
@@ -3581,16 +3583,16 @@
                 Py_DECREF(enter);
                 goto error;
             }
-            #line 3585 "Python/generated_cases.c.h"
+            #line 3587 "Python/generated_cases.c.h"
             Py_DECREF(mgr);
-            #line 2539 "Python/bytecodes.c"
+            #line 2541 "Python/bytecodes.c"
             res = _PyObject_CallNoArgs(enter);
             Py_DECREF(enter);
             if (res == NULL) {
                 Py_DECREF(exit);
                 if (true) goto pop_1_error;
             }
-            #line 3594 "Python/generated_cases.c.h"
+            #line 3596 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             stack_pointer[-2] = exit;
@@ -3602,7 +3604,7 @@
             PyObject *lasti = stack_pointer[-3];
             PyObject *exit_func = stack_pointer[-4];
             PyObject *res;
-            #line 2548 "Python/bytecodes.c"
+            #line 2550 "Python/bytecodes.c"
             /* At the top of the stack are 4 values:
                - val: TOP = exc_info()
                - unused: SECOND = previous exception
@@ -3623,7 +3625,7 @@
             res = PyObject_Vectorcall(exit_func, stack + 1,
                     3 | PY_VECTORCALL_ARGUMENTS_OFFSET, NULL);
             if (res == NULL) goto error;
-            #line 3627 "Python/generated_cases.c.h"
+            #line 3629 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = res;
             DISPATCH();
@@ -3632,7 +3634,7 @@
         TARGET(PUSH_EXC_INFO) {
             PyObject *new_exc = stack_pointer[-1];
             PyObject *prev_exc;
-            #line 2587 "Python/bytecodes.c"
+            #line 2589 "Python/bytecodes.c"
             _PyErr_StackItem *exc_info = tstate->exc_info;
             if (exc_info->exc_value != NULL) {
                 prev_exc = exc_info->exc_value;
@@ -3642,7 +3644,7 @@
             }
             assert(PyExceptionInstance_Check(new_exc));
             exc_info->exc_value = Py_NewRef(new_exc);
-            #line 3646 "Python/generated_cases.c.h"
+            #line 3648 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = new_exc;
             stack_pointer[-2] = prev_exc;
@@ -3656,7 +3658,7 @@
             uint32_t type_version = read_u32(&next_instr[1].cache);
             uint32_t keys_version = read_u32(&next_instr[3].cache);
             PyObject *descr = read_obj(&next_instr[5].cache);
-            #line 2599 "Python/bytecodes.c"
+            #line 2601 "Python/bytecodes.c"
             /* Cached method object */
             PyTypeObject *self_cls = Py_TYPE(self);
             assert(type_version != 0);
@@ -3673,7 +3675,7 @@
             assert(_PyType_HasFeature(Py_TYPE(res2), Py_TPFLAGS_METHOD_DESCRIPTOR));
             res = self;
             assert(oparg & 1);
-            #line 3677 "Python/generated_cases.c.h"
+            #line 3679 "Python/generated_cases.c.h"
             STACK_GROW(((oparg & 1) ? 1 : 0));
             stack_pointer[-1] = res;
             if (oparg & 1) { stack_pointer[-(1 + ((oparg & 1) ? 1 : 0))] = res2; }
@@ -3687,7 +3689,7 @@
             PyObject *res;
             uint32_t type_version = read_u32(&next_instr[1].cache);
             PyObject *descr = read_obj(&next_instr[5].cache);
-            #line 2618 "Python/bytecodes.c"
+            #line 2620 "Python/bytecodes.c"
             PyTypeObject *self_cls = Py_TYPE(self);
             DEOPT_IF(self_cls->tp_version_tag != type_version, LOAD_ATTR);
             assert(self_cls->tp_dictoffset == 0);
@@ -3697,7 +3699,7 @@
             res2 = Py_NewRef(descr);
             res = self;
             assert(oparg & 1);
-            #line 3701 "Python/generated_cases.c.h"
+            #line 3703 "Python/generated_cases.c.h"
             STACK_GROW(((oparg & 1) ? 1 : 0));
             stack_pointer[-1] = res;
             if (oparg & 1) { stack_pointer[-(1 + ((oparg & 1) ? 1 : 0))] = res2; }
@@ -3711,7 +3713,7 @@
             PyObject *res;
             uint32_t type_version = read_u32(&next_instr[1].cache);
             PyObject *descr = read_obj(&next_instr[5].cache);
-            #line 2630 "Python/bytecodes.c"
+            #line 2632 "Python/bytecodes.c"
             PyTypeObject *self_cls = Py_TYPE(self);
             DEOPT_IF(self_cls->tp_version_tag != type_version, LOAD_ATTR);
             Py_ssize_t dictoffset = self_cls->tp_dictoffset;
@@ -3725,7 +3727,7 @@
             res2 = Py_NewRef(descr);
             res = self;
             assert(oparg & 1);
-            #line 3729 "Python/generated_cases.c.h"
+            #line 3731 "Python/generated_cases.c.h"
             STACK_GROW(((oparg & 1) ? 1 : 0));
             stack_pointer[-1] = res;
             if (oparg & 1) { stack_pointer[-(1 + ((oparg & 1) ? 1 : 0))] = res2; }
@@ -3734,16 +3736,16 @@
         }
 
         TARGET(KW_NAMES) {
-            #line 2646 "Python/bytecodes.c"
+            #line 2648 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg < PyTuple_GET_SIZE(FRAME_CO_CONSTS));
             kwnames = GETITEM(FRAME_CO_CONSTS, oparg);
-            #line 3742 "Python/generated_cases.c.h"
+            #line 3744 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_CALL) {
-            #line 2652 "Python/bytecodes.c"
+            #line 2654 "Python/bytecodes.c"
             int is_meth = PEEK(oparg+2) != NULL;
             int total_args = oparg + is_meth;
             PyObject *function = PEEK(total_args + 1);
@@ -3756,7 +3758,7 @@
             _PyCallCache *cache = (_PyCallCache *)next_instr;
             INCREMENT_ADAPTIVE_COUNTER(cache->counter);
             GO_TO_INSTRUCTION(CALL);
-            #line 3760 "Python/generated_cases.c.h"
+            #line 3762 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL) {
@@ -3766,7 +3768,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2698 "Python/bytecodes.c"
+            #line 2700 "Python/bytecodes.c"
             int is_meth = method != NULL;
             int total_args = oparg;
             if (is_meth) {
@@ -3848,7 +3850,7 @@
                 Py_DECREF(args[i]);
             }
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 3852 "Python/generated_cases.c.h"
+            #line 3854 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -3860,7 +3862,7 @@
         TARGET(CALL_BOUND_METHOD_EXACT_ARGS) {
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
-            #line 2786 "Python/bytecodes.c"
+            #line 2788 "Python/bytecodes.c"
             DEOPT_IF(method != NULL, CALL);
             DEOPT_IF(Py_TYPE(callable) != &PyMethod_Type, CALL);
             STAT_INC(CALL, hit);
@@ -3870,7 +3872,7 @@
             PEEK(oparg + 2) = Py_NewRef(meth);  // method
             Py_DECREF(callable);
             GO_TO_INSTRUCTION(CALL_PY_EXACT_ARGS);
-            #line 3874 "Python/generated_cases.c.h"
+            #line 3876 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_PY_EXACT_ARGS) {
@@ -3879,7 +3881,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             uint32_t func_version = read_u32(&next_instr[1].cache);
-            #line 2798 "Python/bytecodes.c"
+            #line 2800 "Python/bytecodes.c"
             assert(kwnames == NULL);
             DEOPT_IF(tstate->interp->eval_frame, CALL);
             int is_meth = method != NULL;
@@ -3905,7 +3907,7 @@
             SKIP_OVER(INLINE_CACHE_ENTRIES_CALL);
             frame->return_offset = 0;
             DISPATCH_INLINED(new_frame);
-            #line 3909 "Python/generated_cases.c.h"
+            #line 3911 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_PY_WITH_DEFAULTS) {
@@ -3913,7 +3915,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             uint32_t func_version = read_u32(&next_instr[1].cache);
-            #line 2826 "Python/bytecodes.c"
+            #line 2828 "Python/bytecodes.c"
             assert(kwnames == NULL);
             DEOPT_IF(tstate->interp->eval_frame, CALL);
             int is_meth = method != NULL;
@@ -3949,7 +3951,7 @@
             SKIP_OVER(INLINE_CACHE_ENTRIES_CALL);
             frame->return_offset = 0;
             DISPATCH_INLINED(new_frame);
-            #line 3953 "Python/generated_cases.c.h"
+            #line 3955 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_NO_KW_TYPE_1) {
@@ -3957,7 +3959,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *null = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2864 "Python/bytecodes.c"
+            #line 2866 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 1);
             DEOPT_IF(null != NULL, CALL);
@@ -3967,7 +3969,7 @@
             res = Py_NewRef(Py_TYPE(obj));
             Py_DECREF(obj);
             Py_DECREF(&PyType_Type);  // I.e., callable
-            #line 3971 "Python/generated_cases.c.h"
+            #line 3973 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -3980,7 +3982,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *null = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2876 "Python/bytecodes.c"
+            #line 2878 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 1);
             DEOPT_IF(null != NULL, CALL);
@@ -3991,7 +3993,7 @@
             Py_DECREF(arg);
             Py_DECREF(&PyUnicode_Type);  // I.e., callable
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 3995 "Python/generated_cases.c.h"
+            #line 3997 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4005,7 +4007,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *null = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2890 "Python/bytecodes.c"
+            #line 2892 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 1);
             DEOPT_IF(null != NULL, CALL);
@@ -4016,7 +4018,7 @@
             Py_DECREF(arg);
             Py_DECREF(&PyTuple_Type);  // I.e., tuple
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4020 "Python/generated_cases.c.h"
+            #line 4022 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4029,7 +4031,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *null = stack_pointer[-(2 + oparg)];
-            #line 2904 "Python/bytecodes.c"
+            #line 2906 "Python/bytecodes.c"
             /* This instruction does the following:
              * 1. Creates the object (by calling ``object.__new__``)
              * 2. Pushes a shim frame to the frame stack (to cleanup after ``__init__``)
@@ -4079,12 +4081,12 @@
             frame = cframe.current_frame = init_frame;
             CALL_STAT_INC(inlined_py_calls);
             goto start_frame;
-            #line 4083 "Python/generated_cases.c.h"
+            #line 4085 "Python/generated_cases.c.h"
         }
 
         TARGET(EXIT_INIT_CHECK) {
             PyObject *should_be_none = stack_pointer[-1];
-            #line 2956 "Python/bytecodes.c"
+            #line 2958 "Python/bytecodes.c"
             assert(STACK_LEVEL() == 2);
             if (should_be_none != Py_None) {
                 PyErr_Format(PyExc_TypeError,
@@ -4092,7 +4094,7 @@
                     Py_TYPE(should_be_none)->tp_name);
                 goto error;
             }
-            #line 4096 "Python/generated_cases.c.h"
+            #line 4098 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             DISPATCH();
         }
@@ -4102,7 +4104,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2966 "Python/bytecodes.c"
+            #line 2968 "Python/bytecodes.c"
             int is_meth = method != NULL;
             int total_args = oparg;
             if (is_meth) {
@@ -4124,7 +4126,7 @@
             }
             Py_DECREF(tp);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4128 "Python/generated_cases.c.h"
+            #line 4130 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4138,7 +4140,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 2991 "Python/bytecodes.c"
+            #line 2993 "Python/bytecodes.c"
             /* Builtin METH_O functions */
             assert(kwnames == NULL);
             int is_meth = method != NULL;
@@ -4166,7 +4168,7 @@
             Py_DECREF(arg);
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4170 "Python/generated_cases.c.h"
+            #line 4172 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4180,7 +4182,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3022 "Python/bytecodes.c"
+            #line 3024 "Python/bytecodes.c"
             /* Builtin METH_FASTCALL functions, without keywords */
             assert(kwnames == NULL);
             int is_meth = method != NULL;
@@ -4212,7 +4214,7 @@
                    'invalid'). In those cases an exception is set, so we must
                    handle it.
                 */
-            #line 4216 "Python/generated_cases.c.h"
+            #line 4218 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4226,7 +4228,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3057 "Python/bytecodes.c"
+            #line 3059 "Python/bytecodes.c"
             /* Builtin METH_FASTCALL | METH_KEYWORDS functions */
             int is_meth = method != NULL;
             int total_args = oparg;
@@ -4258,7 +4260,7 @@
             }
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4262 "Python/generated_cases.c.h"
+            #line 4264 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4272,7 +4274,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3092 "Python/bytecodes.c"
+            #line 3094 "Python/bytecodes.c"
             assert(kwnames == NULL);
             /* len(o) */
             int is_meth = method != NULL;
@@ -4297,7 +4299,7 @@
             Py_DECREF(callable);
             Py_DECREF(arg);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4301 "Python/generated_cases.c.h"
+            #line 4303 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4310,7 +4312,7 @@
             PyObject *callable = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3119 "Python/bytecodes.c"
+            #line 3121 "Python/bytecodes.c"
             assert(kwnames == NULL);
             /* isinstance(o, o2) */
             int is_meth = method != NULL;
@@ -4337,7 +4339,7 @@
             Py_DECREF(cls);
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4341 "Python/generated_cases.c.h"
+            #line 4343 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4349,7 +4351,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *self = stack_pointer[-(1 + oparg)];
             PyObject *method = stack_pointer[-(2 + oparg)];
-            #line 3149 "Python/bytecodes.c"
+            #line 3151 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 1);
             assert(method != NULL);
@@ -4367,14 +4369,14 @@
             SKIP_OVER(INLINE_CACHE_ENTRIES_CALL + 1);
             assert(next_instr[-1].op.code == POP_TOP);
             DISPATCH();
-            #line 4371 "Python/generated_cases.c.h"
+            #line 4373 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_NO_KW_METHOD_DESCRIPTOR_O) {
             PyObject **args = (stack_pointer - oparg);
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3169 "Python/bytecodes.c"
+            #line 3171 "Python/bytecodes.c"
             assert(kwnames == NULL);
             int is_meth = method != NULL;
             int total_args = oparg;
@@ -4405,7 +4407,7 @@
             Py_DECREF(arg);
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4409 "Python/generated_cases.c.h"
+            #line 4411 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4418,7 +4420,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3203 "Python/bytecodes.c"
+            #line 3205 "Python/bytecodes.c"
             int is_meth = method != NULL;
             int total_args = oparg;
             if (is_meth) {
@@ -4447,7 +4449,7 @@
             }
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4451 "Python/generated_cases.c.h"
+            #line 4453 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4460,7 +4462,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3235 "Python/bytecodes.c"
+            #line 3237 "Python/bytecodes.c"
             assert(kwnames == NULL);
             assert(oparg == 0 || oparg == 1);
             int is_meth = method != NULL;
@@ -4489,7 +4491,7 @@
             Py_DECREF(self);
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4493 "Python/generated_cases.c.h"
+            #line 4495 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4502,7 +4504,7 @@
             PyObject **args = (stack_pointer - oparg);
             PyObject *method = stack_pointer[-(2 + oparg)];
             PyObject *res;
-            #line 3267 "Python/bytecodes.c"
+            #line 3269 "Python/bytecodes.c"
             assert(kwnames == NULL);
             int is_meth = method != NULL;
             int total_args = oparg;
@@ -4530,7 +4532,7 @@
             }
             Py_DECREF(callable);
             if (res == NULL) { STACK_SHRINK(oparg); goto pop_2_error; }
-            #line 4534 "Python/generated_cases.c.h"
+            #line 4536 "Python/generated_cases.c.h"
             STACK_SHRINK(oparg);
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
@@ -4540,9 +4542,9 @@
         }
 
         TARGET(INSTRUMENTED_CALL_FUNCTION_EX) {
-            #line 3298 "Python/bytecodes.c"
+            #line 3300 "Python/bytecodes.c"
             GO_TO_INSTRUCTION(CALL_FUNCTION_EX);
-            #line 4546 "Python/generated_cases.c.h"
+            #line 4548 "Python/generated_cases.c.h"
         }
 
         TARGET(CALL_FUNCTION_EX) {
@@ -4551,7 +4553,7 @@
             PyObject *callargs = stack_pointer[-(1 + ((oparg & 1) ? 1 : 0))];
             PyObject *func = stack_pointer[-(2 + ((oparg & 1) ? 1 : 0))];
             PyObject *result;
-            #line 3302 "Python/bytecodes.c"
+            #line 3304 "Python/bytecodes.c"
             // DICT_MERGE is called before this opcode if there are kwargs.
             // It converts all dict subtypes in kwargs into regular dicts.
             assert(kwargs == NULL || PyDict_CheckExact(kwargs));
@@ -4613,14 +4615,14 @@
                 }
                 result = PyObject_Call(func, callargs, kwargs);
             }
-            #line 4617 "Python/generated_cases.c.h"
+            #line 4619 "Python/generated_cases.c.h"
             Py_DECREF(func);
             Py_DECREF(callargs);
             Py_XDECREF(kwargs);
-            #line 3364 "Python/bytecodes.c"
+            #line 3366 "Python/bytecodes.c"
             assert(PEEK(3 + (oparg & 1)) == NULL);
             if (result == NULL) { STACK_SHRINK(((oparg & 1) ? 1 : 0)); goto pop_3_error; }
-            #line 4624 "Python/generated_cases.c.h"
+            #line 4626 "Python/generated_cases.c.h"
             STACK_SHRINK(((oparg & 1) ? 1 : 0));
             STACK_SHRINK(2);
             stack_pointer[-1] = result;
@@ -4631,7 +4633,7 @@
         TARGET(MAKE_FUNCTION) {
             PyObject *codeobj = stack_pointer[-1];
             PyObject *func;
-            #line 3370 "Python/bytecodes.c"
+            #line 3372 "Python/bytecodes.c"
 
             PyFunctionObject *func_obj = (PyFunctionObject *)
                 PyFunction_New(codeobj, GLOBALS());
@@ -4643,7 +4645,7 @@
 
             func_obj->func_version = ((PyCodeObject *)codeobj)->co_version;
             func = (PyObject *)func_obj;
-            #line 4647 "Python/generated_cases.c.h"
+            #line 4649 "Python/generated_cases.c.h"
             stack_pointer[-1] = func;
             DISPATCH();
         }
@@ -4651,7 +4653,7 @@
         TARGET(SET_FUNCTION_ATTRIBUTE) {
             PyObject *func = stack_pointer[-1];
             PyObject *attr = stack_pointer[-2];
-            #line 3384 "Python/bytecodes.c"
+            #line 3386 "Python/bytecodes.c"
             assert(PyFunction_Check(func));
             PyFunctionObject *func_obj = (PyFunctionObject *)func;
             switch(oparg) {
@@ -4676,14 +4678,14 @@
                 default:
                     Py_UNREACHABLE();
             }
-            #line 4680 "Python/generated_cases.c.h"
+            #line 4682 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             stack_pointer[-1] = func;
             DISPATCH();
         }
 
         TARGET(RETURN_GENERATOR) {
-            #line 3411 "Python/bytecodes.c"
+            #line 3413 "Python/bytecodes.c"
             assert(PyFunction_Check(frame->f_funcobj));
             PyFunctionObject *func = (PyFunctionObject *)frame->f_funcobj;
             PyGenObject *gen = (PyGenObject *)_Py_MakeCoro(func);
@@ -4704,7 +4706,7 @@
             frame = cframe.current_frame = prev;
             _PyFrame_StackPush(frame, (PyObject *)gen);
             goto resume_frame;
-            #line 4708 "Python/generated_cases.c.h"
+            #line 4710 "Python/generated_cases.c.h"
         }
 
         TARGET(BUILD_SLICE) {
@@ -4712,15 +4714,15 @@
             PyObject *stop = stack_pointer[-(1 + ((oparg == 3) ? 1 : 0))];
             PyObject *start = stack_pointer[-(2 + ((oparg == 3) ? 1 : 0))];
             PyObject *slice;
-            #line 3434 "Python/bytecodes.c"
+            #line 3436 "Python/bytecodes.c"
             slice = PySlice_New(start, stop, step);
-            #line 4718 "Python/generated_cases.c.h"
+            #line 4720 "Python/generated_cases.c.h"
             Py_DECREF(start);
             Py_DECREF(stop);
             Py_XDECREF(step);
-            #line 3436 "Python/bytecodes.c"
+            #line 3438 "Python/bytecodes.c"
             if (slice == NULL) { STACK_SHRINK(((oparg == 3) ? 1 : 0)); goto pop_2_error; }
-            #line 4724 "Python/generated_cases.c.h"
+            #line 4726 "Python/generated_cases.c.h"
             STACK_SHRINK(((oparg == 3) ? 1 : 0));
             STACK_SHRINK(1);
             stack_pointer[-1] = slice;
@@ -4730,14 +4732,14 @@
         TARGET(CONVERT_VALUE) {
             PyObject *value = stack_pointer[-1];
             PyObject *result;
-            #line 3440 "Python/bytecodes.c"
+            #line 3442 "Python/bytecodes.c"
             convertion_func_ptr  conv_fn;
             assert(oparg >= FVC_STR && oparg <= FVC_ASCII);
             conv_fn = CONVERSION_FUNCTIONS[oparg];
             result = conv_fn(value);
             Py_DECREF(value);
             if (result == NULL) goto pop_1_error;
-            #line 4741 "Python/generated_cases.c.h"
+            #line 4743 "Python/generated_cases.c.h"
             stack_pointer[-1] = result;
             DISPATCH();
         }
@@ -4745,7 +4747,7 @@
         TARGET(FORMAT_SIMPLE) {
             PyObject *value = stack_pointer[-1];
             PyObject *res;
-            #line 3449 "Python/bytecodes.c"
+            #line 3451 "Python/bytecodes.c"
             /* If value is a unicode object, then we know the result
              * of format(value) is value itself. */
             if (!PyUnicode_CheckExact(value)) {
@@ -4756,7 +4758,7 @@
             else {
                 res = value;
             }
-            #line 4760 "Python/generated_cases.c.h"
+            #line 4762 "Python/generated_cases.c.h"
             stack_pointer[-1] = res;
             DISPATCH();
         }
@@ -4765,12 +4767,12 @@
             PyObject *fmt_spec = stack_pointer[-1];
             PyObject *value = stack_pointer[-2];
             PyObject *res;
-            #line 3462 "Python/bytecodes.c"
+            #line 3464 "Python/bytecodes.c"
             res = PyObject_Format(value, fmt_spec);
             Py_DECREF(value);
             Py_DECREF(fmt_spec);
             if (res == NULL) goto pop_2_error;
-            #line 4774 "Python/generated_cases.c.h"
+            #line 4776 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
             DISPATCH();
@@ -4779,10 +4781,10 @@
         TARGET(COPY) {
             PyObject *bottom = stack_pointer[-(1 + (oparg-1))];
             PyObject *top;
-            #line 3469 "Python/bytecodes.c"
+            #line 3471 "Python/bytecodes.c"
             assert(oparg > 0);
             top = Py_NewRef(bottom);
-            #line 4786 "Python/generated_cases.c.h"
+            #line 4788 "Python/generated_cases.c.h"
             STACK_GROW(1);
             stack_pointer[-1] = top;
             DISPATCH();
@@ -4794,7 +4796,7 @@
             PyObject *rhs = stack_pointer[-1];
             PyObject *lhs = stack_pointer[-2];
             PyObject *res;
-            #line 3474 "Python/bytecodes.c"
+            #line 3476 "Python/bytecodes.c"
             #if ENABLE_SPECIALIZATION
             _PyBinaryOpCache *cache = (_PyBinaryOpCache *)next_instr;
             if (ADAPTIVE_COUNTER_IS_ZERO(cache->counter)) {
@@ -4809,12 +4811,12 @@
             assert((unsigned)oparg < Py_ARRAY_LENGTH(binary_ops));
             assert(binary_ops[oparg]);
             res = binary_ops[oparg](lhs, rhs);
-            #line 4813 "Python/generated_cases.c.h"
+            #line 4815 "Python/generated_cases.c.h"
             Py_DECREF(lhs);
             Py_DECREF(rhs);
-            #line 3489 "Python/bytecodes.c"
+            #line 3491 "Python/bytecodes.c"
             if (res == NULL) goto pop_2_error;
-            #line 4818 "Python/generated_cases.c.h"
+            #line 4820 "Python/generated_cases.c.h"
             STACK_SHRINK(1);
             stack_pointer[-1] = res;
             next_instr += 1;
@@ -4824,16 +4826,16 @@
         TARGET(SWAP) {
             PyObject *top = stack_pointer[-1];
             PyObject *bottom = stack_pointer[-(2 + (oparg-2))];
-            #line 3494 "Python/bytecodes.c"
+            #line 3496 "Python/bytecodes.c"
             assert(oparg >= 2);
-            #line 4830 "Python/generated_cases.c.h"
+            #line 4832 "Python/generated_cases.c.h"
             stack_pointer[-1] = bottom;
             stack_pointer[-(2 + (oparg-2))] = top;
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_INSTRUCTION) {
-            #line 3498 "Python/bytecodes.c"
+            #line 3500 "Python/bytecodes.c"
             int next_opcode = _Py_call_instrumentation_instruction(
                 tstate, frame, next_instr-1);
             if (next_opcode < 0) goto error;
@@ -4845,26 +4847,26 @@
             assert(next_opcode > 0 && next_opcode < 256);
             opcode = next_opcode;
             DISPATCH_GOTO();
-            #line 4849 "Python/generated_cases.c.h"
+            #line 4851 "Python/generated_cases.c.h"
         }
 
         TARGET(INSTRUMENTED_JUMP_FORWARD) {
-            #line 3512 "Python/bytecodes.c"
+            #line 3514 "Python/bytecodes.c"
             INSTRUMENTED_JUMP(next_instr-1, next_instr+oparg, PY_MONITORING_EVENT_JUMP);
-            #line 4855 "Python/generated_cases.c.h"
+            #line 4857 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_JUMP_BACKWARD) {
-            #line 3516 "Python/bytecodes.c"
+            #line 3518 "Python/bytecodes.c"
             CHECK_EVAL_BREAKER();
             INSTRUMENTED_JUMP(next_instr-1, next_instr+1-oparg, PY_MONITORING_EVENT_JUMP);
-            #line 4863 "Python/generated_cases.c.h"
+            #line 4865 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_POP_JUMP_IF_TRUE) {
-            #line 3521 "Python/bytecodes.c"
+            #line 3523 "Python/bytecodes.c"
             PyObject *cond = POP();
             int err = PyObject_IsTrue(cond);
             Py_DECREF(cond);
@@ -4873,12 +4875,12 @@
             assert(err == 0 || err == 1);
             int offset = err*oparg;
             INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
-            #line 4877 "Python/generated_cases.c.h"
+            #line 4879 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_POP_JUMP_IF_FALSE) {
-            #line 3532 "Python/bytecodes.c"
+            #line 3534 "Python/bytecodes.c"
             PyObject *cond = POP();
             int err = PyObject_IsTrue(cond);
             Py_DECREF(cond);
@@ -4887,12 +4889,12 @@
             assert(err == 0 || err == 1);
             int offset = (1-err)*oparg;
             INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
-            #line 4891 "Python/generated_cases.c.h"
+            #line 4893 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_POP_JUMP_IF_NONE) {
-            #line 3543 "Python/bytecodes.c"
+            #line 3545 "Python/bytecodes.c"
             PyObject *value = POP();
             _Py_CODEUNIT *here = next_instr-1;
             int offset;
@@ -4904,12 +4906,12 @@
                 offset = 0;
             }
             INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
-            #line 4908 "Python/generated_cases.c.h"
+            #line 4910 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(INSTRUMENTED_POP_JUMP_IF_NOT_NONE) {
-            #line 3557 "Python/bytecodes.c"
+            #line 3559 "Python/bytecodes.c"
             PyObject *value = POP();
             _Py_CODEUNIT *here = next_instr-1;
             int offset;
@@ -4921,30 +4923,30 @@
                  offset = oparg;
             }
             INSTRUMENTED_JUMP(here, next_instr + offset, PY_MONITORING_EVENT_BRANCH);
-            #line 4925 "Python/generated_cases.c.h"
+            #line 4927 "Python/generated_cases.c.h"
             DISPATCH();
         }
 
         TARGET(EXTENDED_ARG) {
-            #line 3571 "Python/bytecodes.c"
+            #line 3573 "Python/bytecodes.c"
             assert(oparg);
             opcode = next_instr->op.code;
             oparg = oparg << 8 | next_instr->op.arg;
             PRE_DISPATCH_GOTO();
             DISPATCH_GOTO();
-            #line 4936 "Python/generated_cases.c.h"
+            #line 4938 "Python/generated_cases.c.h"
         }
 
         TARGET(CACHE) {
-            #line 3579 "Python/bytecodes.c"
+            #line 3581 "Python/bytecodes.c"
             assert(0 && "Executing a cache.");
             Py_UNREACHABLE();
-            #line 4943 "Python/generated_cases.c.h"
+            #line 4945 "Python/generated_cases.c.h"
         }
 
         TARGET(RESERVED) {
-            #line 3584 "Python/bytecodes.c"
+            #line 3586 "Python/bytecodes.c"
             assert(0 && "Executing RESERVED instruction.");
             Py_UNREACHABLE();
-            #line 4950 "Python/generated_cases.c.h"
+            #line 4952 "Python/generated_cases.c.h"
         }
diff --git a/Python/opcode_metadata.h b/Python/opcode_metadata.h
index 4e31a5e69614bb..05d8e1d52e8de0 100644
--- a/Python/opcode_metadata.h
+++ b/Python/opcode_metadata.h
@@ -1048,7 +1048,7 @@ const struct opcode_metadata _PyOpcode_opcode_metadata[512] = {
     [JUMP_BACKWARD] = { true, INSTR_FMT_IB, HAS_ARG_FLAG | HAS_JUMP_FLAG },
     [JUMP] = { true, INSTR_FMT_IB, HAS_ARG_FLAG | HAS_JUMP_FLAG },
     [JUMP_NO_INTERRUPT] = { true, INSTR_FMT_IB, HAS_ARG_FLAG | HAS_JUMP_FLAG },
-    [ENTER_EXECUTOR] = { true, INSTR_FMT_IB, HAS_ARG_FLAG },
+    [ENTER_EXECUTOR] = { true, INSTR_FMT_IB, HAS_ARG_FLAG | HAS_JUMP_FLAG },
     [POP_JUMP_IF_FALSE] = { true, INSTR_FMT_IB, HAS_ARG_FLAG | HAS_JUMP_FLAG },
     [POP_JUMP_IF_TRUE] = { true, INSTR_FMT_IB, HAS_ARG_FLAG | HAS_JUMP_FLAG },
     [POP_JUMP_IF_NOT_NONE] = { true, INSTR_FMT_IB, HAS_ARG_FLAG | HAS_JUMP_FLAG },

From f4d88647eaea97b47d45f807949f23514b9aa243 Mon Sep 17 00:00:00 2001
From: Mark Shannon <mark@hotpy.org>
Date: Wed, 21 Jun 2023 09:57:41 +0100
Subject: [PATCH 3/4] Remove label

---
 Python/ceval.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/Python/ceval.c b/Python/ceval.c
index 3e0dcf8c8629b9..6cea48d4324673 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -763,8 +763,6 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
 
     DISPATCH();
 
-handle_eval_breaker:
-
     /* Do periodic things, like check for signals and async I/0.
      * We need to do reasonably frequently, but not too frequently.
      * All loops should include a check of the eval breaker.

From 94947b983439f837fca80191021410be4feb923f Mon Sep 17 00:00:00 2001
From: Mark Shannon <mark@hotpy.org>
Date: Mon, 3 Jul 2023 13:57:55 +0100
Subject: [PATCH 4/4] Address review comments

---
 Include/internal/pycore_ceval.h |  2 +
 Python/bytecodes.c              |  6 ++-
 Python/ceval.c                  | 68 +--------------------------------
 Python/ceval_gil.c              | 61 ++++++++++++++++++++++++++++-
 4 files changed, 66 insertions(+), 71 deletions(-)

diff --git a/Include/internal/pycore_ceval.h b/Include/internal/pycore_ceval.h
index 9e9b523e7c2222..46bc18cff86d5a 100644
--- a/Include/internal/pycore_ceval.h
+++ b/Include/internal/pycore_ceval.h
@@ -152,6 +152,8 @@ extern struct _PyInterpreterFrame* _PyEval_GetFrame(void);
 
 extern PyObject* _Py_MakeCoro(PyFunctionObject *func);
 
+/* Handle signals, pending calls, GIL drop request
+   and asynchronous exception */
 extern int _Py_HandlePending(PyThreadState *tstate);
 
 
diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index 7eb4cd66da8146..f16d86c1332101 100644
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -2175,10 +2175,12 @@ dummy_func(
 
         inst(ENTER_EXECUTOR, (--)) {
             CHECK_EVAL_BREAKER();
-            JUMPBY(1-oparg);
-            frame->prev_instr = next_instr - 1;
+
             PyCodeObject *code = _PyFrame_GetCode(frame);
             _PyExecutorObject *executor = (_PyExecutorObject *)code->co_executors->executors[oparg&255];
+            int original_oparg = executor->vm_data.oparg | (oparg & 0xfffff00);
+            JUMPBY(1-original_oparg);
+            frame->prev_instr = next_instr - 1;
             Py_INCREF(executor);
             frame = executor->execute(executor, frame, stack_pointer);
             if (frame == NULL) {
diff --git a/Python/ceval.c b/Python/ceval.c
index 6cea48d4324673..51c3acfa599fcf 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -763,66 +763,6 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
 
     DISPATCH();
 
-    /* Do periodic things, like check for signals and async I/0.
-     * We need to do reasonably frequently, but not too frequently.
-     * All loops should include a check of the eval breaker.
-     * We also check on return from any builtin function.
-     *
-     * ## More Details ###
-     *
-     * The eval loop (this function) normally executes the instructions
-     * of a code object sequentially.  However, the runtime supports a
-     * number of out-of-band execution scenarios that may pause that
-     * sequential execution long enough to do that out-of-band work
-     * in the current thread using the current PyThreadState.
-     *
-     * The scenarios include:
-     *
-     *  - cyclic garbage collection
-     *  - GIL drop requests
-     *  - "async" exceptions
-     *  - "pending calls"  (some only in the main thread)
-     *  - signal handling (only in the main thread)
-     *
-     * When the need for one of the above is detected, the eval loop
-     * pauses long enough to handle the detected case.  Then, if doing
-     * so didn't trigger an exception, the eval loop resumes executing
-     * the sequential instructions.
-     *
-     * To make this work, the eval loop periodically checks if any
-     * of the above needs to happen.  The individual checks can be
-     * expensive if computed each time, so a while back we switched
-     * to using pre-computed, per-interpreter variables for the checks,
-     * and later consolidated that to a single "eval breaker" variable
-     * (now a PyInterpreterState field).
-     *
-     * For the longest time, the eval breaker check would happen
-     * frequently, every 5 or so times through the loop, regardless
-     * of what instruction ran last or what would run next.  Then, in
-     * early 2021 (gh-18334, commit 4958f5d), we switched to checking
-     * the eval breaker less frequently, by hard-coding the check to
-     * specific places in the eval loop (e.g. certain instructions).
-     * The intent then was to check after returning from calls
-     * and on the back edges of loops.
-     *
-     * In addition to being more efficient, that approach keeps
-     * the eval loop from running arbitrary code between instructions
-     * that don't handle that well.  (See gh-74174.)
-     *
-     * Currently, the eval breaker check happens here at the
-     * "handle_eval_breaker" label.  Some instructions come here
-     * explicitly (goto) and some indirectly.  Notably, the check
-     * happens on back edges in the control flow graph, which
-     * pretty much applies to all loops and most calls.
-     * (See bytecodes.c for exact information.)
-     *
-     * One consequence of this approach is that it might not be obvious
-     * how to force any specific thread to pick up the eval breaker,
-     * or for any specific thread to not pick it up.  Mostly this
-     * involves judicious uses of locks and careful ordering of code,
-     * while avoiding code that might trigger the eval breaker
-     * until so desired.
-     */
     if (_Py_HandlePending(tstate) != 0) {
         goto error;
     }
@@ -2794,13 +2734,7 @@ _PyUopExecute(_PyExecutorObject *executor, _PyInterpreterFrame *frame, PyObject
     PyThreadState *tstate = _PyThreadState_GET();
     _PyUOpExecutorObject *self = (_PyUOpExecutorObject *)executor;
 
-    // Equivalent to CHECK_EVAL_BREAKER()
-    _Py_CHECK_EMSCRIPTEN_SIGNALS_PERIODICALLY();
-    if (_Py_atomic_load_relaxed_int32(&tstate->interp->ceval.eval_breaker)) {
-        if (_Py_HandlePending(tstate) != 0) {
-            goto error;
-        }
-    }
+    CHECK_EVAL_BREAKER();
 
     OBJECT_STAT_INC(optimization_traces_executed);
     _Py_CODEUNIT *ip_offset = (_Py_CODEUNIT *)_PyFrame_GetCode(frame)->co_code_adaptive - 1;
diff --git a/Python/ceval_gil.c b/Python/ceval_gil.c
index bb1279f46cf9f7..caf506122fba86 100644
--- a/Python/ceval_gil.c
+++ b/Python/ceval_gil.c
@@ -1052,8 +1052,65 @@ _PyEval_FiniState(struct _ceval_state *ceval)
     }
 }
 
-/* Handle signals, pending calls, GIL drop request
-   and asynchronous exception */
+
+/* Do periodic things, like check for signals and async I/0.
+* We need to do reasonably frequently, but not too frequently.
+* All loops should include a check of the eval breaker.
+* We also check on return from any builtin function.
+*
+* ## More Details ###
+*
+* The eval loop (this function) normally executes the instructions
+* of a code object sequentially.  However, the runtime supports a
+* number of out-of-band execution scenarios that may pause that
+* sequential execution long enough to do that out-of-band work
+* in the current thread using the current PyThreadState.
+*
+* The scenarios include:
+*
+*  - cyclic garbage collection
+*  - GIL drop requests
+*  - "async" exceptions
+*  - "pending calls"  (some only in the main thread)
+*  - signal handling (only in the main thread)
+*
+* When the need for one of the above is detected, the eval loop
+* pauses long enough to handle the detected case.  Then, if doing
+* so didn't trigger an exception, the eval loop resumes executing
+* the sequential instructions.
+*
+* To make this work, the eval loop periodically checks if any
+* of the above needs to happen.  The individual checks can be
+* expensive if computed each time, so a while back we switched
+* to using pre-computed, per-interpreter variables for the checks,
+* and later consolidated that to a single "eval breaker" variable
+* (now a PyInterpreterState field).
+*
+* For the longest time, the eval breaker check would happen
+* frequently, every 5 or so times through the loop, regardless
+* of what instruction ran last or what would run next.  Then, in
+* early 2021 (gh-18334, commit 4958f5d), we switched to checking
+* the eval breaker less frequently, by hard-coding the check to
+* specific places in the eval loop (e.g. certain instructions).
+* The intent then was to check after returning from calls
+* and on the back edges of loops.
+*
+* In addition to being more efficient, that approach keeps
+* the eval loop from running arbitrary code between instructions
+* that don't handle that well.  (See gh-74174.)
+*
+* Currently, the eval breaker check happens on back edges in
+* the control flow graph, which pretty much applies to all loops,
+* and most calls.
+* (See bytecodes.c for exact information.)
+*
+* One consequence of this approach is that it might not be obvious
+* how to force any specific thread to pick up the eval breaker,
+* or for any specific thread to not pick it up.  Mostly this
+* involves judicious uses of locks and careful ordering of code,
+* while avoiding code that might trigger the eval breaker
+* until so desired.
+*/
 int
 _Py_HandlePending(PyThreadState *tstate)
 {