cpython/Python/ceval.c

/* Execute compiled code */

#define _PY_INTERPRETER

#include "Python.h"
#include "pycore_abstract.h"      // _PyIndex_Check()
#include "pycore_audit.h"         // _PySys_Audit()
#include "pycore_backoff.h"
#include "pycore_call.h"          // _PyObject_CallNoArgs()
#include "pycore_cell.h"          // PyCell_GetRef()
#include "pycore_ceval.h"
#include "pycore_code.h"
#include "pycore_emscripten_signal.h"  // _Py_CHECK_EMSCRIPTEN_SIGNALS
#include "pycore_function.h"
#include "pycore_instruments.h"
#include "pycore_intrinsics.h"
#include "pycore_jit.h"
#include "pycore_long.h"          // _PyLong_GetZero()
#include "pycore_moduleobject.h"  // PyModuleObject
#include "pycore_object.h"        // _PyObject_GC_TRACK()
#include "pycore_opcode_metadata.h" // EXTRA_CASES
#include "pycore_optimizer.h"     // _PyUOpExecutor_Type
#include "pycore_opcode_utils.h"  // MAKE_FUNCTION_*
#include "pycore_pyatomic_ft_wrappers.h" // FT_ATOMIC_*
#include "pycore_pyerrors.h"      // _PyErr_GetRaisedException()
#include "pycore_pystate.h"       // _PyInterpreterState_GET()
#include "pycore_range.h"         // _PyRangeIterObject
#include "pycore_setobject.h"     // _PySet_Update()
#include "pycore_sliceobject.h"   // _PyBuildSlice_ConsumeRefs
#include "pycore_tuple.h"         // _PyTuple_ITEMS()
#include "pycore_typeobject.h"    // _PySuper_Lookup()
#include "pycore_uop_ids.h"       // Uops
#include "pycore_pyerrors.h"

#include "pycore_dict.h"
#include "dictobject.h"
#include "pycore_frame.h"
#include "frameobject.h"          // _PyInterpreterFrame_GetLine
#include "opcode.h"
#include "pydtrace.h"
#include "setobject.h"
#include "pycore_stackref.h"

#include <stdbool.h>              // bool

#ifdef Py_DEBUG
   /* For debugging the interpreter: */
#  define LLTRACE  1      /* Low-level trace feature */
#endif

#if !defined(Py_BUILD_CORE)
#  error "ceval.c must be build with Py_BUILD_CORE define for best performance"
#endif

#if !defined(Py_DEBUG) && !defined(Py_TRACE_REFS)
// GH-89279: The MSVC compiler does not inline these static inline functions
// in PGO build in _PyEval_EvalFrameDefault(), because this function is over
// the limit of PGO, and that limit cannot be configured.
// Define them as macros to make sure that they are always inlined by the
// preprocessor.

#undef Py_IS_TYPE
#define Py_IS_TYPE(ob, type) \
    (_PyObject_CAST(ob)->ob_type == (type))

#undef Py_XDECREF
#define Py_XDECREF(arg) \
    do { \
        PyObject *xop = _PyObject_CAST(arg); \
        if (xop != NULL) { \
            Py_DECREF(xop); \
        } \
    } while (0)

#ifndef Py_GIL_DISABLED

#undef Py_DECREF
#define Py_DECREF(arg) \
    do { \
        PyObject *op = _PyObject_CAST(arg); \
        if (_Py_IsImmortal(op)) { \
            _Py_DECREF_IMMORTAL_STAT_INC(); \
            break; \
        } \
        _Py_DECREF_STAT_INC(); \
        if (--op->ob_refcnt == 0) { \
            destructor dealloc = Py_TYPE(op)->tp_dealloc; \
            (*dealloc)(op); \
        } \
    } while (0)

#undef _Py_DECREF_SPECIALIZED
#define _Py_DECREF_SPECIALIZED(arg, dealloc) \
    do { \
        PyObject *op = _PyObject_CAST(arg); \
        if (_Py_IsImmortal(op)) { \
            _Py_DECREF_IMMORTAL_STAT_INC(); \
            break; \
        } \
        _Py_DECREF_STAT_INC(); \
        if (--op->ob_refcnt == 0) { \
            struct _reftracer_runtime_state *tracer = &_PyRuntime.ref_tracer; \
            if (tracer->tracer_func != NULL) { \
                void* data = tracer->tracer_data; \
                tracer->tracer_func(op, PyRefTracer_DESTROY, data); \
            } \
            destructor d = (destructor)(dealloc); \
            d(op); \
        } \
    } while (0)

#else // Py_GIL_DISABLED

#undef Py_DECREF
#define Py_DECREF(arg) \
    do { \
        PyObject *op = _PyObject_CAST(arg); \
        uint32_t local = _Py_atomic_load_uint32_relaxed(&op->ob_ref_local); \
        if (local == _Py_IMMORTAL_REFCNT_LOCAL) { \
            _Py_DECREF_IMMORTAL_STAT_INC(); \
            break; \
        } \
        _Py_DECREF_STAT_INC(); \
        if (_Py_IsOwnedByCurrentThread(op)) { \
            local--; \
            _Py_atomic_store_uint32_relaxed(&op->ob_ref_local, local); \
            if (local == 0) { \
                _Py_MergeZeroLocalRefcount(op); \
            } \
        } \
        else { \
            _Py_DecRefShared(op); \
        } \
    } while (0)

#undef _Py_DECREF_SPECIALIZED
#define _Py_DECREF_SPECIALIZED(arg, dealloc) Py_DECREF(arg)

#endif
#endif


#ifdef LLTRACE
static void
dump_stack(_PyInterpreterFrame *frame, _PyStackRef *stack_pointer)
{
    _PyStackRef *stack_base = _PyFrame_Stackbase(frame);
    PyObject *exc = PyErr_GetRaisedException();
    printf("    stack=[");
    for (_PyStackRef *ptr = stack_base; ptr < stack_pointer; ptr++) {
        if (ptr != stack_base) {
            printf(", ");
        }
        PyObject *obj = PyStackRef_AsPyObjectBorrow(*ptr);
        if (obj == NULL) {
            printf("<nil>");
            continue;
        }
        if (
            obj == Py_None
            || PyBool_Check(obj)
            || PyLong_CheckExact(obj)
            || PyFloat_CheckExact(obj)
            || PyUnicode_CheckExact(obj)
        ) {
            if (PyObject_Print(obj, stdout, 0) == 0) {
                continue;
            }
            PyErr_Clear();
        }
        // Don't call __repr__(), it might recurse into the interpreter.
        printf("<%s at %p>", Py_TYPE(obj)->tp_name, (void *)(ptr->bits));
    }
    printf("]\n");
    fflush(stdout);
    PyErr_SetRaisedException(exc);
}

static void
lltrace_instruction(_PyInterpreterFrame *frame,
                    _PyStackRef *stack_pointer,
                    _Py_CODEUNIT *next_instr,
                    int opcode,
                    int oparg)
{
    if (frame->owner == FRAME_OWNED_BY_CSTACK) {
        return;
    }
    dump_stack(frame, stack_pointer);
    const char *opname = _PyOpcode_OpName[opcode];
    assert(opname != NULL);
    int offset = (int)(next_instr - _PyFrame_GetBytecode(frame));
    if (OPCODE_HAS_ARG((int)_PyOpcode_Deopt[opcode])) {
        printf("%d: %s %d\n", offset * 2, opname, oparg);
    }
    else {
        printf("%d: %s\n", offset * 2, opname);
    }
    fflush(stdout);
}
static void
lltrace_resume_frame(_PyInterpreterFrame *frame)
{
    PyObject *fobj = PyStackRef_AsPyObjectBorrow(frame->f_funcobj);
    if (!PyStackRef_CodeCheck(frame->f_executable) ||
        fobj == NULL ||
        !PyFunction_Check(fobj)
    ) {
        printf("\nResuming frame.\n");
        return;
    }
    PyFunctionObject *f = (PyFunctionObject *)fobj;
    PyObject *exc = PyErr_GetRaisedException();
    PyObject *name = f->func_qualname;
    if (name == NULL) {
        name = f->func_name;
    }
    printf("\nResuming frame");
    if (name) {
        printf(" for ");
        if (PyObject_Print(name, stdout, 0) < 0) {
            PyErr_Clear();
        }
    }
    if (f->func_module) {
        printf(" in module ");
        if (PyObject_Print(f->func_module, stdout, 0) < 0) {
            PyErr_Clear();
        }
    }
    printf("\n");
    fflush(stdout);
    PyErr_SetRaisedException(exc);
}

static int
maybe_lltrace_resume_frame(_PyInterpreterFrame *frame, _PyInterpreterFrame *skip_frame, PyObject *globals)
{
    if (globals == NULL) {
        return 0;
    }
    if (frame == skip_frame) {
        return 0;
    }
    int r = PyDict_Contains(globals, &_Py_ID(__lltrace__));
    if (r < 0) {
        return -1;
    }
    int lltrace = r * 5;  // Levels 1-4 only trace uops
    if (!lltrace) {
        // Can also be controlled by environment variable
        char *python_lltrace = Py_GETENV("PYTHON_LLTRACE");
        if (python_lltrace != NULL && *python_lltrace >= '0') {
            lltrace = *python_lltrace - '0';  // TODO: Parse an int and all that
        }
    }
    if (lltrace >= 5) {
        lltrace_resume_frame(frame);
    }
    return lltrace;
}

#endif

static void monitor_reraise(PyThreadState *tstate,
                 _PyInterpreterFrame *frame,
                 _Py_CODEUNIT *instr);
static int monitor_stop_iteration(PyThreadState *tstate,
                 _PyInterpreterFrame *frame,
                 _Py_CODEUNIT *instr,
                 PyObject *value);
static void monitor_unwind(PyThreadState *tstate,
                 _PyInterpreterFrame *frame,
                 _Py_CODEUNIT *instr);
static int monitor_handled(PyThreadState *tstate,
                 _PyInterpreterFrame *frame,
                 _Py_CODEUNIT *instr, PyObject *exc);
static void monitor_throw(PyThreadState *tstate,
                 _PyInterpreterFrame *frame,
                 _Py_CODEUNIT *instr);

static int get_exception_handler(PyCodeObject *, int, int*, int*, int*);
static  _PyInterpreterFrame *
_PyEvalFramePushAndInit_Ex(PyThreadState *tstate, _PyStackRef func,
    PyObject *locals, Py_ssize_t nargs, PyObject *callargs, PyObject *kwargs, _PyInterpreterFrame *previous);

#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif

int
Py_GetRecursionLimit(void)
{
    PyInterpreterState *interp = _PyInterpreterState_GET();
    return interp->ceval.recursion_limit;
}

void
Py_SetRecursionLimit(int new_limit)
{
    PyInterpreterState *interp = _PyInterpreterState_GET();
    interp->ceval.recursion_limit = new_limit;
    for (PyThreadState *p = interp->threads.head; p != NULL; p = p->next) {
        int depth = p->py_recursion_limit - p->py_recursion_remaining;
        p->py_recursion_limit = new_limit;
        p->py_recursion_remaining = new_limit - depth;
    }
}

/* The function _Py_EnterRecursiveCallTstate() only calls _Py_CheckRecursiveCall()
   if the recursion_depth reaches recursion_limit. */
int
_Py_CheckRecursiveCall(PyThreadState *tstate, const char *where)
{
#ifdef USE_STACKCHECK
    if (PyOS_CheckStack()) {
        ++tstate->c_recursion_remaining;
        _PyErr_SetString(tstate, PyExc_MemoryError, "Stack overflow");
        return -1;
    }
#endif
    if (tstate->recursion_headroom) {
        if (tstate->c_recursion_remaining < -50) {
            /* Overflowing while handling an overflow. Give up. */
            Py_FatalError("Cannot recover from stack overflow.");
        }
    }
    else {
        if (tstate->c_recursion_remaining <= 0) {
            tstate->recursion_headroom++;
            _PyErr_Format(tstate, PyExc_RecursionError,
                        "maximum recursion depth exceeded%s",
                        where);
            tstate->recursion_headroom--;
            ++tstate->c_recursion_remaining;
            return -1;
        }
    }
    return 0;
}


const binaryfunc _PyEval_BinaryOps[] = {
    [NB_ADD] = PyNumber_Add,
    [NB_AND] = PyNumber_And,
    [NB_FLOOR_DIVIDE] = PyNumber_FloorDivide,
    [NB_LSHIFT] = PyNumber_Lshift,
    [NB_MATRIX_MULTIPLY] = PyNumber_MatrixMultiply,
    [NB_MULTIPLY] = PyNumber_Multiply,
    [NB_REMAINDER] = PyNumber_Remainder,
    [NB_OR] = PyNumber_Or,
    [NB_POWER] = _PyNumber_PowerNoMod,
    [NB_RSHIFT] = PyNumber_Rshift,
    [NB_SUBTRACT] = PyNumber_Subtract,
    [NB_TRUE_DIVIDE] = PyNumber_TrueDivide,
    [NB_XOR] = PyNumber_Xor,
    [NB_INPLACE_ADD] = PyNumber_InPlaceAdd,
    [NB_INPLACE_AND] = PyNumber_InPlaceAnd,
    [NB_INPLACE_FLOOR_DIVIDE] = PyNumber_InPlaceFloorDivide,
    [NB_INPLACE_LSHIFT] = PyNumber_InPlaceLshift,
    [NB_INPLACE_MATRIX_MULTIPLY] = PyNumber_InPlaceMatrixMultiply,
    [NB_INPLACE_MULTIPLY] = PyNumber_InPlaceMultiply,
    [NB_INPLACE_REMAINDER] = PyNumber_InPlaceRemainder,
    [NB_INPLACE_OR] = PyNumber_InPlaceOr,
    [NB_INPLACE_POWER] = _PyNumber_InPlacePowerNoMod,
    [NB_INPLACE_RSHIFT] = PyNumber_InPlaceRshift,
    [NB_INPLACE_SUBTRACT] = PyNumber_InPlaceSubtract,
    [NB_INPLACE_TRUE_DIVIDE] = PyNumber_InPlaceTrueDivide,
    [NB_INPLACE_XOR] = PyNumber_InPlaceXor,
};

const conversion_func _PyEval_ConversionFuncs[4] = {
    [FVC_STR] = PyObject_Str,
    [FVC_REPR] = PyObject_Repr,
    [FVC_ASCII] = PyObject_ASCII
};

const _Py_SpecialMethod _Py_SpecialMethods[] = {
    [SPECIAL___ENTER__] = {
        .name = &_Py_ID(__enter__),
        .error = "'%.200s' object does not support the "
                 "context manager protocol (missed __enter__ method)",
    },
    [SPECIAL___EXIT__] = {
        .name = &_Py_ID(__exit__),
        .error = "'%.200s' object does not support the "
                 "context manager protocol (missed __exit__ method)",
    },
    [SPECIAL___AENTER__] = {
        .name = &_Py_ID(__aenter__),
        .error = "'%.200s' object does not support the asynchronous "
                 "context manager protocol (missed __aenter__ method)",
    },
    [SPECIAL___AEXIT__] = {
        .name = &_Py_ID(__aexit__),
        .error = "'%.200s' object does not support the asynchronous "
                 "context manager protocol (missed __aexit__ method)",
    }
};

const size_t _Py_FunctionAttributeOffsets[] = {
    [MAKE_FUNCTION_CLOSURE] = offsetof(PyFunctionObject, func_closure),
    [MAKE_FUNCTION_ANNOTATIONS] = offsetof(PyFunctionObject, func_annotations),
    [MAKE_FUNCTION_KWDEFAULTS] = offsetof(PyFunctionObject, func_kwdefaults),
    [MAKE_FUNCTION_DEFAULTS] = offsetof(PyFunctionObject, func_defaults),
    [MAKE_FUNCTION_ANNOTATE] = offsetof(PyFunctionObject, func_annotate),
};

// PEP 634: Structural Pattern Matching


// Return a tuple of values corresponding to keys, with error checks for
// duplicate/missing keys.
PyObject *
_PyEval_MatchKeys(PyThreadState *tstate, PyObject *map, PyObject *keys)
{
    assert(PyTuple_CheckExact(keys));
    Py_ssize_t nkeys = PyTuple_GET_SIZE(keys);
    if (!nkeys) {
        // No keys means no items.
        return PyTuple_New(0);
    }
    PyObject *seen = NULL;
    PyObject *dummy = NULL;
    PyObject *values = NULL;
    PyObject *get = NULL;
    // We use the two argument form of map.get(key, default) for two reasons:
    // - Atomically check for a key and get its value without error handling.
    // - Don't cause key creation or resizing in dict subclasses like
    //   collections.defaultdict that define __missing__ (or similar).
    int meth_found = _PyObject_GetMethod(map, &_Py_ID(get), &get);
    if (get == NULL) {
        goto fail;
    }
    seen = PySet_New(NULL);
    if (seen == NULL) {
        goto fail;
    }
    // dummy = object()
    dummy = _PyObject_CallNoArgs((PyObject *)&PyBaseObject_Type);
    if (dummy == NULL) {
        goto fail;
    }
    values = PyTuple_New(nkeys);
    if (values == NULL) {
        goto fail;
    }
    for (Py_ssize_t i = 0; i < nkeys; i++) {
        PyObject *key = PyTuple_GET_ITEM(keys, i);
        if (PySet_Contains(seen, key) || PySet_Add(seen, key)) {
            if (!_PyErr_Occurred(tstate)) {
                // Seen it before!
                _PyErr_Format(tstate, PyExc_ValueError,
                              "mapping pattern checks duplicate key (%R)", key);
            }
            goto fail;
        }
        PyObject *args[] = { map, key, dummy };
        PyObject *value = NULL;
        if (meth_found) {
            value = PyObject_Vectorcall(get, args, 3, NULL);
        }
        else {
            value = PyObject_Vectorcall(get, &args[1], 2, NULL);
        }
        if (value == NULL) {
            goto fail;
        }
        if (value == dummy) {
            // key not in map!
            Py_DECREF(value);
            Py_DECREF(values);
            // Return None:
            values = Py_NewRef(Py_None);
            goto done;
        }
        PyTuple_SET_ITEM(values, i, value);
    }
    // Success:
done:
    Py_DECREF(get);
    Py_DECREF(seen);
    Py_DECREF(dummy);
    return values;
fail:
    Py_XDECREF(get);
    Py_XDECREF(seen);
    Py_XDECREF(dummy);
    Py_XDECREF(values);
    return NULL;
}

// Extract a named attribute from the subject, with additional bookkeeping to
// raise TypeErrors for repeated lookups. On failure, return NULL (with no
// error set). Use _PyErr_Occurred(tstate) to disambiguate.
static PyObject *
match_class_attr(PyThreadState *tstate, PyObject *subject, PyObject *type,
                 PyObject *name, PyObject *seen)
{
    assert(PyUnicode_CheckExact(name));
    assert(PySet_CheckExact(seen));
    if (PySet_Contains(seen, name) || PySet_Add(seen, name)) {
        if (!_PyErr_Occurred(tstate)) {
            // Seen it before!
            _PyErr_Format(tstate, PyExc_TypeError,
                          "%s() got multiple sub-patterns for attribute %R",
                          ((PyTypeObject*)type)->tp_name, name);
        }
        return NULL;
    }
    PyObject *attr;
    (void)PyObject_GetOptionalAttr(subject, name, &attr);
    return attr;
}

// On success (match), return a tuple of extracted attributes. On failure (no
// match), return NULL. Use _PyErr_Occurred(tstate) to disambiguate.
PyObject*
_PyEval_MatchClass(PyThreadState *tstate, PyObject *subject, PyObject *type,
                   Py_ssize_t nargs, PyObject *kwargs)
{
    if (!PyType_Check(type)) {
        const char *e = "called match pattern must be a class";
        _PyErr_Format(tstate, PyExc_TypeError, e);
        return NULL;
    }
    assert(PyTuple_CheckExact(kwargs));
    // First, an isinstance check:
    if (PyObject_IsInstance(subject, type) <= 0) {
        return NULL;
    }
    // So far so good:
    PyObject *seen = PySet_New(NULL);
    if (seen == NULL) {
        return NULL;
    }
    PyObject *attrs = PyList_New(0);
    if (attrs == NULL) {
        Py_DECREF(seen);
        return NULL;
    }
    // NOTE: From this point on, goto fail on failure:
    PyObject *match_args = NULL;
    // First, the positional subpatterns:
    if (nargs) {
        int match_self = 0;
        if (PyObject_GetOptionalAttr(type, &_Py_ID(__match_args__), &match_args) < 0) {
            goto fail;
        }
        if (match_args) {
            if (!PyTuple_CheckExact(match_args)) {
                const char *e = "%s.__match_args__ must be a tuple (got %s)";
                _PyErr_Format(tstate, PyExc_TypeError, e,
                              ((PyTypeObject *)type)->tp_name,
                              Py_TYPE(match_args)->tp_name);
                goto fail;
            }
        }
        else {
            // _Py_TPFLAGS_MATCH_SELF is only acknowledged if the type does not
            // define __match_args__. This is natural behavior for subclasses:
            // it's as if __match_args__ is some "magic" value that is lost as
            // soon as they redefine it.
            match_args = PyTuple_New(0);
            match_self = PyType_HasFeature((PyTypeObject*)type,
                                            _Py_TPFLAGS_MATCH_SELF);
        }
        assert(PyTuple_CheckExact(match_args));
        Py_ssize_t allowed = match_self ? 1 : PyTuple_GET_SIZE(match_args);
        if (allowed < nargs) {
            const char *plural = (allowed == 1) ? "" : "s";
            _PyErr_Format(tstate, PyExc_TypeError,
                          "%s() accepts %d positional sub-pattern%s (%d given)",
                          ((PyTypeObject*)type)->tp_name,
                          allowed, plural, nargs);
            goto fail;
        }
        if (match_self) {
            // Easy. Copy the subject itself, and move on to kwargs.
            if (PyList_Append(attrs, subject) < 0) {
                goto fail;
            }
        }
        else {
            for (Py_ssize_t i = 0; i < nargs; i++) {
                PyObject *name = PyTuple_GET_ITEM(match_args, i);
                if (!PyUnicode_CheckExact(name)) {
                    _PyErr_Format(tstate, PyExc_TypeError,
                                  "__match_args__ elements must be strings "
                                  "(got %s)", Py_TYPE(name)->tp_name);
                    goto fail;
                }
                PyObject *attr = match_class_attr(tstate, subject, type, name,
                                                  seen);
                if (attr == NULL) {
                    goto fail;
                }
                if (PyList_Append(attrs, attr) < 0) {
                    Py_DECREF(attr);
                    goto fail;
                }
                Py_DECREF(attr);
            }
        }
        Py_CLEAR(match_args);
    }
    // Finally, the keyword subpatterns:
    for (Py_ssize_t i = 0; i < PyTuple_GET_SIZE(kwargs); i++) {
        PyObject *name = PyTuple_GET_ITEM(kwargs, i);
        PyObject *attr = match_class_attr(tstate, subject, type, name, seen);
        if (attr == NULL) {
            goto fail;
        }
        if (PyList_Append(attrs, attr) < 0) {
            Py_DECREF(attr);
            goto fail;
        }
        Py_DECREF(attr);
    }
    Py_SETREF(attrs, PyList_AsTuple(attrs));
    Py_DECREF(seen);
    return attrs;
fail:
    // We really don't care whether an error was raised or not... that's our
    // caller's problem. All we know is that the match failed.
    Py_XDECREF(match_args);
    Py_DECREF(seen);
    Py_DECREF(attrs);
    return NULL;
}


static int do_raise(PyThreadState *tstate, PyObject *exc, PyObject *cause);

PyObject *
PyEval_EvalCode(PyObject *co, PyObject *globals, PyObject *locals)
{
    PyThreadState *tstate = _PyThreadState_GET();
    if (locals == NULL) {
        locals = globals;
    }
    PyObject *builtins = _PyDict_LoadBuiltinsFromGlobals(globals);
    if (builtins == NULL) {
        return NULL;
    }
    PyFrameConstructor desc = {
        .fc_globals = globals,
        .fc_builtins = builtins,
        .fc_name = ((PyCodeObject *)co)->co_name,
        .fc_qualname = ((PyCodeObject *)co)->co_name,
        .fc_code = co,
        .fc_defaults = NULL,
        .fc_kwdefaults = NULL,
        .fc_closure = NULL
    };
    PyFunctionObject *func = _PyFunction_FromConstructor(&desc);
    _Py_DECREF_BUILTINS(builtins);
    if (func == NULL) {
        return NULL;
    }
    EVAL_CALL_STAT_INC(EVAL_CALL_LEGACY);
    PyObject *res = _PyEval_Vector(tstate, func, locals, NULL, 0, NULL);
    Py_DECREF(func);
    return res;
}


/* Interpreter main loop */

PyObject *
PyEval_EvalFrame(PyFrameObject *f)
{
    /* Function kept for backward compatibility */
    PyThreadState *tstate = _PyThreadState_GET();
    return _PyEval_EvalFrame(tstate, f->f_frame, 0);
}

PyObject *
PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
{
    PyThreadState *tstate = _PyThreadState_GET();
    return _PyEval_EvalFrame(tstate, f->f_frame, throwflag);
}

#include "ceval_macros.h"

int _Py_CheckRecursiveCallPy(
    PyThreadState *tstate)
{
    if (tstate->recursion_headroom) {
        if (tstate->py_recursion_remaining < -50) {
            /* Overflowing while handling an overflow. Give up. */
            Py_FatalError("Cannot recover from Python stack overflow.");
        }
    }
    else {
        if (tstate->py_recursion_remaining <= 0) {
            tstate->recursion_headroom++;
            _PyErr_Format(tstate, PyExc_RecursionError,
                        "maximum recursion depth exceeded");
            tstate->recursion_headroom--;
            return -1;
        }
    }
    return 0;
}

static const _Py_CODEUNIT _Py_INTERPRETER_TRAMPOLINE_INSTRUCTIONS[] = {
    /* Put a NOP at the start, so that the IP points into
    * the code, rather than before it */
    { .op.code = NOP, .op.arg = 0 },
    { .op.code = INTERPRETER_EXIT, .op.arg = 0 },  /* reached on return */
    { .op.code = NOP, .op.arg = 0 },
    { .op.code = INTERPRETER_EXIT, .op.arg = 0 },  /* reached on yield */
    { .op.code = RESUME, .op.arg = RESUME_OPARG_DEPTH1_MASK | RESUME_AT_FUNC_START }
};

#ifdef Py_DEBUG
extern void _PyUOpPrint(const _PyUOpInstruction *uop);
#endif


/* Disable unused label warnings.  They are handy for debugging, even
   if computed gotos aren't used. */

/* TBD - what about other compilers? */
#if defined(__GNUC__)
#  pragma GCC diagnostic push
#  pragma GCC diagnostic ignored "-Wunused-label"
#elif defined(_MSC_VER) /* MS_WINDOWS */
#  pragma warning(push)
#  pragma warning(disable:4102)
#endif


PyObject **
_PyObjectArray_FromStackRefArray(_PyStackRef *input, Py_ssize_t nargs, PyObject **scratch)
{
    PyObject **result;
    if (nargs > MAX_STACKREF_SCRATCH) {
        // +1 in case PY_VECTORCALL_ARGUMENTS_OFFSET is set.
        result = PyMem_Malloc((nargs + 1) * sizeof(PyObject *));
        if (result == NULL) {
            return NULL;
        }
        result++;
    }
    else {
        result = scratch;
    }
    for (int i = 0; i < nargs; i++) {
        result[i] = PyStackRef_AsPyObjectBorrow(input[i]);
    }
    return result;
}

void
_PyObjectArray_Free(PyObject **array, PyObject **scratch)
{
    if (array != scratch) {
        PyMem_Free(array);
    }
}


/* _PyEval_EvalFrameDefault() is a *big* function,
 * so consume 3 units of C stack */
#define PY_EVAL_C_STACK_UNITS 2


/* _PyEval_EvalFrameDefault is too large to optimize for speed with PGO on MSVC
   when the JIT is enabled or GIL is disabled. Disable that optimization around
   this function only. If this is fixed upstream, we should gate this on the
   version of MSVC.
 */
#if (defined(_MSC_VER) && \
     defined(_Py_USING_PGO) && \
     (defined(_Py_JIT) || \
      defined(Py_GIL_DISABLED)))
#define DO_NOT_OPTIMIZE_INTERP_LOOP
#endif

#ifdef DO_NOT_OPTIMIZE_INTERP_LOOP
#  pragma optimize("t", off)
/* This setting is reversed below following _PyEval_EvalFrameDefault */
#endif

PyObject* _Py_HOT_FUNCTION
_PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int throwflag)
{
    _Py_EnsureTstateNotNULL(tstate);
    CALL_STAT_INC(pyeval_calls);

#if USE_COMPUTED_GOTOS
/* Import the static jump table */
#include "opcode_targets.h"
#endif

#ifdef Py_STATS
    int lastopcode = 0;
#endif
    uint8_t opcode;    /* Current opcode */
    int oparg;         /* Current opcode argument, if any */
#ifdef LLTRACE
    int lltrace = 0;
#endif

    _PyInterpreterFrame  entry_frame;



#ifdef Py_DEBUG
    /* Set these to invalid but identifiable values for debugging. */
    entry_frame.f_funcobj = (_PyStackRef){.bits = 0xaaa0};
    entry_frame.f_locals = (PyObject*)0xaaa1;
    entry_frame.frame_obj = (PyFrameObject*)0xaaa2;
    entry_frame.f_globals = (PyObject*)0xaaa3;
    entry_frame.f_builtins = (PyObject*)0xaaa4;
#endif
    entry_frame.f_executable = PyStackRef_None;
    entry_frame.instr_ptr = (_Py_CODEUNIT *)_Py_INTERPRETER_TRAMPOLINE_INSTRUCTIONS + 1;
    entry_frame.stackpointer = entry_frame.localsplus;
    entry_frame.owner = FRAME_OWNED_BY_CSTACK;
    entry_frame.return_offset = 0;
    /* Push frame */
    entry_frame.previous = tstate->current_frame;
    frame->previous = &entry_frame;
    tstate->current_frame = frame;

    tstate->c_recursion_remaining -= (PY_EVAL_C_STACK_UNITS - 1);
    if (_Py_EnterRecursiveCallTstate(tstate, "")) {
        tstate->c_recursion_remaining--;
        tstate->py_recursion_remaining--;
        goto exit_unwind;
    }

    /* support for generator.throw() */
    if (throwflag) {
        if (_Py_EnterRecursivePy(tstate)) {
            goto exit_unwind;
        }
        /* Because this avoids the RESUME,
         * we need to update instrumentation */
#ifdef Py_GIL_DISABLED
        /* Load thread-local bytecode */
        if (frame->tlbc_index != ((_PyThreadStateImpl *)tstate)->tlbc_index) {
            _Py_CODEUNIT *bytecode =
                _PyEval_GetExecutableCode(tstate, _PyFrame_GetCode(frame));
            if (bytecode == NULL) {
                goto error;
            }
            ptrdiff_t off = frame->instr_ptr - _PyFrame_GetBytecode(frame);
            frame->tlbc_index = ((_PyThreadStateImpl *)tstate)->tlbc_index;
            frame->instr_ptr = bytecode + off;
        }
#endif
        _Py_Instrument(_PyFrame_GetCode(frame), tstate->interp);
        monitor_throw(tstate, frame, frame->instr_ptr);
        /* TO DO -- Monitor throw entry. */
        goto resume_with_error;
    }

    /* Local "register" variables.
     * These are cached values from the frame and code object.  */
    _Py_CODEUNIT *next_instr;
    _PyStackRef *stack_pointer;

#if defined(_Py_TIER2) && !defined(_Py_JIT)
    /* Tier 2 interpreter state */
    _PyExecutorObject *current_executor = NULL;
    const _PyUOpInstruction *next_uop = NULL;
#endif

start_frame:
    if (_Py_EnterRecursivePy(tstate)) {
        goto exit_unwind;
    }

    next_instr = frame->instr_ptr;
resume_frame:
    stack_pointer = _PyFrame_GetStackPointer(frame);

#ifdef LLTRACE
    lltrace = maybe_lltrace_resume_frame(frame, &entry_frame, GLOBALS());
    if (lltrace < 0) {
        goto exit_unwind;
    }
#endif

#ifdef Py_DEBUG
    /* _PyEval_EvalFrameDefault() must not be called with an exception set,
       because it can clear it (directly or indirectly) and so the
       caller loses its exception */
    assert(!_PyErr_Occurred(tstate));
#endif

    DISPATCH();

    {
    /* Start instructions */
#if !USE_COMPUTED_GOTOS
    dispatch_opcode:
        switch (opcode)
#endif
        {

#include "generated_cases.c.h"


#if USE_COMPUTED_GOTOS
        _unknown_opcode:
#else
        EXTRA_CASES  // From pycore_opcode_metadata.h, a 'case' for each unused opcode
#endif
            /* Tell C compilers not to hold the opcode variable in the loop.
               next_instr points the current instruction without TARGET(). */
            opcode = next_instr->op.code;
            _PyErr_Format(tstate, PyExc_SystemError,
                          "%U:%d: unknown opcode %d",
                          _PyFrame_GetCode(frame)->co_filename,
                          PyUnstable_InterpreterFrame_GetLine(frame),
                          opcode);
            goto error;

        } /* End instructions */

        /* This should never be reached. Every opcode should end with DISPATCH()
           or goto error. */
        Py_UNREACHABLE();

pop_4_error:
    STACK_SHRINK(1);
pop_3_error:
    STACK_SHRINK(1);
pop_2_error:
    STACK_SHRINK(1);
pop_1_error:
    STACK_SHRINK(1);
error:
        /* Double-check exception status. */
#ifdef NDEBUG
        if (!_PyErr_Occurred(tstate)) {
            _PyErr_SetString(tstate, PyExc_SystemError,
                             "error return without exception set");
        }
#else
        assert(_PyErr_Occurred(tstate));
#endif

        /* Log traceback info. */
        assert(frame != &entry_frame);
        if (!_PyFrame_IsIncomplete(frame)) {
            PyFrameObject *f = _PyFrame_GetFrameObject(frame);
            if (f != NULL) {
                PyTraceBack_Here(f);
            }
        }
        _PyEval_MonitorRaise(tstate, frame, next_instr-1);
exception_unwind:
        {
            /* We can't use frame->instr_ptr here, as RERAISE may have set it */
            int offset = INSTR_OFFSET()-1;
            int level, handler, lasti;
            if (get_exception_handler(_PyFrame_GetCode(frame), offset, &level, &handler, &lasti) == 0) {
                // No handlers, so exit.
                assert(_PyErr_Occurred(tstate));

                /* Pop remaining stack entries. */
                _PyStackRef *stackbase = _PyFrame_Stackbase(frame);
                while (stack_pointer > stackbase) {
                    PyStackRef_XCLOSE(POP());
                }
                assert(STACK_LEVEL() == 0);
                _PyFrame_SetStackPointer(frame, stack_pointer);
                monitor_unwind(tstate, frame, next_instr-1);
                goto exit_unwind;
            }

            assert(STACK_LEVEL() >= level);
            _PyStackRef *new_top = _PyFrame_Stackbase(frame) + level;
            while (stack_pointer > new_top) {
                PyStackRef_XCLOSE(POP());
            }
            if (lasti) {
                int frame_lasti = _PyInterpreterFrame_LASTI(frame);
                PyObject *lasti = PyLong_FromLong(frame_lasti);
                if (lasti == NULL) {
                    goto exception_unwind;
                }
                PUSH(PyStackRef_FromPyObjectSteal(lasti));
            }

            /* Make the raw exception data
                available to the handler,
                so a program can emulate the
                Python main loop. */
            PyObject *exc = _PyErr_GetRaisedException(tstate);
            PUSH(PyStackRef_FromPyObjectSteal(exc));
            next_instr = _PyFrame_GetBytecode(frame) + handler;

            if (monitor_handled(tstate, frame, next_instr, exc) < 0) {
                goto exception_unwind;
            }
            /* Resume normal execution */
#ifdef LLTRACE
            if (lltrace >= 5) {
                lltrace_resume_frame(frame);
            }
#endif
            DISPATCH();
        }
    }

exit_unwind:
    assert(_PyErr_Occurred(tstate));
    _Py_LeaveRecursiveCallPy(tstate);
    assert(frame != &entry_frame);
    // GH-99729: We need to unlink the frame *before* clearing it:
    _PyInterpreterFrame *dying = frame;
    frame = tstate->current_frame = dying->previous;
    _PyEval_FrameClearAndPop(tstate, dying);
    frame->return_offset = 0;
    if (frame == &entry_frame) {
        /* Restore previous frame and exit */
        tstate->current_frame = frame->previous;
        tstate->c_recursion_remaining += PY_EVAL_C_STACK_UNITS;
        return NULL;
    }

resume_with_error:
    next_instr = frame->instr_ptr;
    stack_pointer = _PyFrame_GetStackPointer(frame);
    goto error;


#ifdef _Py_TIER2

// Tier 2 is also here!
enter_tier_two:

#ifdef _Py_JIT
    assert(0);
#else

#undef LOAD_IP
#define LOAD_IP(UNUSED) (void)0

#undef GOTO_ERROR
#define GOTO_ERROR(LABEL) goto LABEL ## _tier_two

#ifdef Py_STATS
// Disable these macros that apply to Tier 1 stats when we are in Tier 2
#undef STAT_INC
#define STAT_INC(opname, name) ((void)0)
#undef STAT_DEC
#define STAT_DEC(opname, name) ((void)0)
#endif

#undef ENABLE_SPECIALIZATION
#define ENABLE_SPECIALIZATION 0
#undef ENABLE_SPECIALIZATION_FT
#define ENABLE_SPECIALIZATION_FT 0

#ifdef Py_DEBUG
    #define DPRINTF(level, ...) \
        if (lltrace >= (level)) { printf(__VA_ARGS__); }
#else
    #define DPRINTF(level, ...)
#endif

    ; // dummy statement after a label, before a declaration
    uint16_t uopcode;
#ifdef Py_STATS
    int lastuop = 0;
    uint64_t trace_uop_execution_counter = 0;
#endif

    assert(next_uop->opcode == _START_EXECUTOR);
tier2_dispatch:
    for (;;) {
        uopcode = next_uop->opcode;
#ifdef Py_DEBUG
        if (lltrace >= 3) {
            dump_stack(frame, stack_pointer);
            if (next_uop->opcode == _START_EXECUTOR) {
                printf("%4d uop: ", 0);
            }
            else {
                printf("%4d uop: ", (int)(next_uop - current_executor->trace));
            }
            _PyUOpPrint(next_uop);
            printf("\n");
        }
#endif
        next_uop++;
        OPT_STAT_INC(uops_executed);
        UOP_STAT_INC(uopcode, execution_count);
        UOP_PAIR_INC(uopcode, lastuop);
#ifdef Py_STATS
        trace_uop_execution_counter++;
#endif

        switch (uopcode) {

#include "executor_cases.c.h"

            default:
#ifdef Py_DEBUG
            {
                printf("Unknown uop: ");
                _PyUOpPrint(&next_uop[-1]);
                printf(" @ %d\n", (int)(next_uop - current_executor->trace - 1));
                Py_FatalError("Unknown uop");
            }
#else
            Py_UNREACHABLE();
#endif

        }
    }

jump_to_error_target:
#ifdef Py_DEBUG
    if (lltrace >= 2) {
        printf("Error: [UOp ");
        _PyUOpPrint(&next_uop[-1]);
        printf(" @ %d -> %s]\n",
               (int)(next_uop - current_executor->trace - 1),
               _PyOpcode_OpName[frame->instr_ptr->op.code]);
    }
#endif
    assert (next_uop[-1].format == UOP_FORMAT_JUMP);
    uint16_t target = uop_get_error_target(&next_uop[-1]);
    next_uop = current_executor->trace + target;
    goto tier2_dispatch;

error_tier_two:
    OPT_HIST(trace_uop_execution_counter, trace_run_length_hist);
    assert(next_uop[-1].format == UOP_FORMAT_TARGET);
    frame->return_offset = 0;  // Don't leave this random
    _PyFrame_SetStackPointer(frame, stack_pointer);
    Py_DECREF(current_executor);
    tstate->previous_executor = NULL;
    goto resume_with_error;

jump_to_jump_target:
    assert(next_uop[-1].format == UOP_FORMAT_JUMP);
    target = uop_get_jump_target(&next_uop[-1]);
    next_uop = current_executor->trace + target;
    goto tier2_dispatch;

exit_to_tier1_dynamic:
    next_instr = frame->instr_ptr;
    goto goto_to_tier1;
exit_to_tier1:
    assert(next_uop[-1].format == UOP_FORMAT_TARGET);
    next_instr = next_uop[-1].target + _PyFrame_GetBytecode(frame);
goto_to_tier1:
#ifdef Py_DEBUG
    if (lltrace >= 2) {
        printf("DEOPT: [UOp ");
        _PyUOpPrint(&next_uop[-1]);
        printf(" -> %s]\n",
               _PyOpcode_OpName[next_instr->op.code]);
    }
#endif
    OPT_HIST(trace_uop_execution_counter, trace_run_length_hist);
    Py_DECREF(current_executor);
    tstate->previous_executor = NULL;
    DISPATCH();

#endif  // _Py_JIT

#endif // _Py_TIER2

}

#ifdef DO_NOT_OPTIMIZE_INTERP_LOOP
#  pragma optimize("", on)
#endif

#if defined(__GNUC__)
#  pragma GCC diagnostic pop
#elif defined(_MSC_VER) /* MS_WINDOWS */
#  pragma warning(pop)
#endif

static void
format_missing(PyThreadState *tstate, const char *kind,
               PyCodeObject *co, PyObject *names, PyObject *qualname)
{
    int err;
    Py_ssize_t len = PyList_GET_SIZE(names);
    PyObject *name_str, *comma, *tail, *tmp;

    assert(PyList_CheckExact(names));
    assert(len >= 1);
    /* Deal with the joys of natural language. */
    switch (len) {
    case 1:
        name_str = PyList_GET_ITEM(names, 0);
        Py_INCREF(name_str);
        break;
    case 2:
        name_str = PyUnicode_FromFormat("%U and %U",
                                        PyList_GET_ITEM(names, len - 2),
                                        PyList_GET_ITEM(names, len - 1));
        break;
    default:
        tail = PyUnicode_FromFormat(", %U, and %U",
                                    PyList_GET_ITEM(names, len - 2),
                                    PyList_GET_ITEM(names, len - 1));
        if (tail == NULL)
            return;
        /* Chop off the last two objects in the list. This shouldn't actually
           fail, but we can't be too careful. */
        err = PyList_SetSlice(names, len - 2, len, NULL);
        if (err == -1) {
            Py_DECREF(tail);
            return;
        }
        /* Stitch everything up into a nice comma-separated list. */
        comma = PyUnicode_FromString(", ");
        if (comma == NULL) {
            Py_DECREF(tail);
            return;
        }
        tmp = PyUnicode_Join(comma, names);
        Py_DECREF(comma);
        if (tmp == NULL) {
            Py_DECREF(tail);
            return;
        }
        name_str = PyUnicode_Concat(tmp, tail);
        Py_DECREF(tmp);
        Py_DECREF(tail);
        break;
    }
    if (name_str == NULL)
        return;
    _PyErr_Format(tstate, PyExc_TypeError,
                  "%U() missing %i required %s argument%s: %U",
                  qualname,
                  len,
                  kind,
                  len == 1 ? "" : "s",
                  name_str);
    Py_DECREF(name_str);
}

static void
missing_arguments(PyThreadState *tstate, PyCodeObject *co,
                  Py_ssize_t missing, Py_ssize_t defcount,
                  _PyStackRef *localsplus, PyObject *qualname)
{
    Py_ssize_t i, j = 0;
    Py_ssize_t start, end;
    int positional = (defcount != -1);
    const char *kind = positional ? "positional" : "keyword-only";
    PyObject *missing_names;

    /* Compute the names of the arguments that are missing. */
    missing_names = PyList_New(missing);
    if (missing_names == NULL)
        return;
    if (positional) {
        start = 0;
        end = co->co_argcount - defcount;
    }
    else {
        start = co->co_argcount;
        end = start + co->co_kwonlyargcount;
    }
    for (i = start; i < end; i++) {
        if (PyStackRef_IsNull(localsplus[i])) {
            PyObject *raw = PyTuple_GET_ITEM(co->co_localsplusnames, i);
            PyObject *name = PyObject_Repr(raw);
            if (name == NULL) {
                Py_DECREF(missing_names);
                return;
            }
            PyList_SET_ITEM(missing_names, j++, name);
        }
    }
    assert(j == missing);
    format_missing(tstate, kind, co, missing_names, qualname);
    Py_DECREF(missing_names);
}

static void
too_many_positional(PyThreadState *tstate, PyCodeObject *co,
                    Py_ssize_t given, PyObject *defaults,
                    _PyStackRef *localsplus, PyObject *qualname)
{
    int plural;
    Py_ssize_t kwonly_given = 0;
    Py_ssize_t i;
    PyObject *sig, *kwonly_sig;
    Py_ssize_t co_argcount = co->co_argcount;

    assert((co->co_flags & CO_VARARGS) == 0);
    /* Count missing keyword-only args. */
    for (i = co_argcount; i < co_argcount + co->co_kwonlyargcount; i++) {
        if (PyStackRef_AsPyObjectBorrow(localsplus[i]) != NULL) {
            kwonly_given++;
        }
    }
    Py_ssize_t defcount = defaults == NULL ? 0 : PyTuple_GET_SIZE(defaults);
    if (defcount) {
        Py_ssize_t atleast = co_argcount - defcount;
        plural = 1;
        sig = PyUnicode_FromFormat("from %zd to %zd", atleast, co_argcount);
    }
    else {
        plural = (co_argcount != 1);
        sig = PyUnicode_FromFormat("%zd", co_argcount);
    }
    if (sig == NULL)
        return;
    if (kwonly_given) {
        const char *format = " positional argument%s (and %zd keyword-only argument%s)";
        kwonly_sig = PyUnicode_FromFormat(format,
                                          given != 1 ? "s" : "",
                                          kwonly_given,
                                          kwonly_given != 1 ? "s" : "");
        if (kwonly_sig == NULL) {
            Py_DECREF(sig);
            return;
        }
    }
    else {
        /* This will not fail. */
        kwonly_sig = Py_GetConstant(Py_CONSTANT_EMPTY_STR);
        assert(kwonly_sig != NULL);
    }
    _PyErr_Format(tstate, PyExc_TypeError,
                  "%U() takes %U positional argument%s but %zd%U %s given",
                  qualname,
                  sig,
                  plural ? "s" : "",
                  given,
                  kwonly_sig,
                  given == 1 && !kwonly_given ? "was" : "were");
    Py_DECREF(sig);
    Py_DECREF(kwonly_sig);
}

static int
positional_only_passed_as_keyword(PyThreadState *tstate, PyCodeObject *co,
                                  Py_ssize_t kwcount, PyObject* kwnames,
                                  PyObject *qualname)
{
    int posonly_conflicts = 0;
    PyObject* posonly_names = PyList_New(0);
    if (posonly_names == NULL) {
        goto fail;
    }
    for(int k=0; k < co->co_posonlyargcount; k++){
        PyObject* posonly_name = PyTuple_GET_ITEM(co->co_localsplusnames, k);

        for (int k2=0; k2<kwcount; k2++){
            /* Compare the pointers first and fallback to PyObject_RichCompareBool*/
            PyObject* kwname = PyTuple_GET_ITEM(kwnames, k2);
            if (kwname == posonly_name){
                if(PyList_Append(posonly_names, kwname) != 0) {
                    goto fail;
                }
                posonly_conflicts++;
                continue;
            }

            int cmp = PyObject_RichCompareBool(posonly_name, kwname, Py_EQ);

            if ( cmp > 0) {
                if(PyList_Append(posonly_names, kwname) != 0) {
                    goto fail;
                }
                posonly_conflicts++;
            } else if (cmp < 0) {
                goto fail;
            }

        }
    }
    if (posonly_conflicts) {
        PyObject* comma = PyUnicode_FromString(", ");
        if (comma == NULL) {
            goto fail;
        }
        PyObject* error_names = PyUnicode_Join(comma, posonly_names);
        Py_DECREF(comma);
        if (error_names == NULL) {
            goto fail;
        }
        _PyErr_Format(tstate, PyExc_TypeError,
                      "%U() got some positional-only arguments passed"
                      " as keyword arguments: '%U'",
                      qualname, error_names);
        Py_DECREF(error_names);
        goto fail;
    }

    Py_DECREF(posonly_names);
    return 0;

fail:
    Py_XDECREF(posonly_names);
    return 1;

}


static inline unsigned char *
scan_back_to_entry_start(unsigned char *p) {
    for (; (p[0]&128) == 0; p--);
    return p;
}

static inline unsigned char *
skip_to_next_entry(unsigned char *p, unsigned char *end) {
    while (p < end && ((p[0] & 128) == 0)) {
        p++;
    }
    return p;
}


#define MAX_LINEAR_SEARCH 40

static int
get_exception_handler(PyCodeObject *code, int index, int *level, int *handler, int *lasti)
{
    unsigned char *start = (unsigned char *)PyBytes_AS_STRING(code->co_exceptiontable);
    unsigned char *end = start + PyBytes_GET_SIZE(code->co_exceptiontable);
    /* Invariants:
     * start_table == end_table OR
     * start_table points to a legal entry and end_table points
     * beyond the table or to a legal entry that is after index.
     */
    if (end - start > MAX_LINEAR_SEARCH) {
        int offset;
        parse_varint(start, &offset);
        if (offset > index) {
            return 0;
        }
        do {
            unsigned char * mid = start + ((end-start)>>1);
            mid = scan_back_to_entry_start(mid);
            parse_varint(mid, &offset);
            if (offset > index) {
                end = mid;
            }
            else {
                start = mid;
            }

        } while (end - start > MAX_LINEAR_SEARCH);
    }
    unsigned char *scan = start;
    while (scan < end) {
        int start_offset, size;
        scan = parse_varint(scan, &start_offset);
        if (start_offset > index) {
            break;
        }
        scan = parse_varint(scan, &size);
        if (start_offset + size > index) {
            scan = parse_varint(scan, handler);
            int depth_and_lasti;
            parse_varint(scan, &depth_and_lasti);
            *level = depth_and_lasti >> 1;
            *lasti = depth_and_lasti & 1;
            return 1;
        }
        scan = skip_to_next_entry(scan, end);
    }
    return 0;
}

static int
initialize_locals(PyThreadState *tstate, PyFunctionObject *func,
    _PyStackRef *localsplus, _PyStackRef const *args,
    Py_ssize_t argcount, PyObject *kwnames)
{
    PyCodeObject *co = (PyCodeObject*)func->func_code;
    const Py_ssize_t total_args = co->co_argcount + co->co_kwonlyargcount;

    /* Create a dictionary for keyword parameters (**kwags) */
    PyObject *kwdict;
    Py_ssize_t i;
    if (co->co_flags & CO_VARKEYWORDS) {
        kwdict = PyDict_New();
        if (kwdict == NULL) {
            goto fail_pre_positional;
        }
        i = total_args;
        if (co->co_flags & CO_VARARGS) {
            i++;
        }
        assert(PyStackRef_IsNull(localsplus[i]));
        localsplus[i] = PyStackRef_FromPyObjectSteal(kwdict);
    }
    else {
        kwdict = NULL;
    }

    /* Copy all positional arguments into local variables */
    Py_ssize_t j, n;
    if (argcount > co->co_argcount) {
        n = co->co_argcount;
    }
    else {
        n = argcount;
    }
    for (j = 0; j < n; j++) {
        assert(PyStackRef_IsNull(localsplus[j]));
        localsplus[j] = args[j];
    }

    /* Pack other positional arguments into the *args argument */
    if (co->co_flags & CO_VARARGS) {
        PyObject *u = NULL;
        if (argcount == n) {
            u = (PyObject *)&_Py_SINGLETON(tuple_empty);
        }
        else {
            u = _PyTuple_FromStackRefSteal(args + n, argcount - n);
        }
        if (u == NULL) {
            goto fail_post_positional;
        }
        assert(PyStackRef_AsPyObjectBorrow(localsplus[total_args]) == NULL);
        localsplus[total_args] = PyStackRef_FromPyObjectSteal(u);
    }
    else if (argcount > n) {
        /* Too many positional args. Error is reported later */
        for (j = n; j < argcount; j++) {
            PyStackRef_CLOSE(args[j]);
        }
    }

    /* Handle keyword arguments */
    if (kwnames != NULL) {
        Py_ssize_t kwcount = PyTuple_GET_SIZE(kwnames);
        for (i = 0; i < kwcount; i++) {
            PyObject **co_varnames;
            PyObject *keyword = PyTuple_GET_ITEM(kwnames, i);
            _PyStackRef value_stackref = args[i+argcount];
            Py_ssize_t j;

            if (keyword == NULL || !PyUnicode_Check(keyword)) {
                _PyErr_Format(tstate, PyExc_TypeError,
                            "%U() keywords must be strings",
                          func->func_qualname);
                goto kw_fail;
            }

            /* Speed hack: do raw pointer compares. As names are
            normally interned this should almost always hit. */
            co_varnames = ((PyTupleObject *)(co->co_localsplusnames))->ob_item;
            for (j = co->co_posonlyargcount; j < total_args; j++) {
                PyObject *varname = co_varnames[j];
                if (varname == keyword) {
                    goto kw_found;
                }
            }

            /* Slow fallback, just in case */
            for (j = co->co_posonlyargcount; j < total_args; j++) {
                PyObject *varname = co_varnames[j];
                int cmp = PyObject_RichCompareBool( keyword, varname, Py_EQ);
                if (cmp > 0) {
                    goto kw_found;
                }
                else if (cmp < 0) {
                    goto kw_fail;
                }
            }

            assert(j >= total_args);
            if (kwdict == NULL) {

                if (co->co_posonlyargcount
                    && positional_only_passed_as_keyword(tstate, co,
                                                        kwcount, kwnames,
                                                        func->func_qualname))
                {
                    goto kw_fail;
                }

                PyObject* suggestion_keyword = NULL;
                if (total_args > co->co_posonlyargcount) {
                    PyObject* possible_keywords = PyList_New(total_args - co->co_posonlyargcount);

                    if (!possible_keywords) {
                        PyErr_Clear();
                    } else {
                        for (Py_ssize_t k = co->co_posonlyargcount; k < total_args; k++) {
                            PyList_SET_ITEM(possible_keywords, k - co->co_posonlyargcount, co_varnames[k]);
                        }

                        suggestion_keyword = _Py_CalculateSuggestions(possible_keywords, keyword);
                        Py_DECREF(possible_keywords);
                    }
                }

                if (suggestion_keyword) {
                    _PyErr_Format(tstate, PyExc_TypeError,
                                "%U() got an unexpected keyword argument '%S'. Did you mean '%S'?",
                                func->func_qualname, keyword, suggestion_keyword);
                    Py_DECREF(suggestion_keyword);
                } else {
                    _PyErr_Format(tstate, PyExc_TypeError,
                                "%U() got an unexpected keyword argument '%S'",
                                func->func_qualname, keyword);
                }

                goto kw_fail;
            }

            if (PyDict_SetItem(kwdict, keyword, PyStackRef_AsPyObjectBorrow(value_stackref)) == -1) {
                goto kw_fail;
            }
            PyStackRef_CLOSE(value_stackref);
            continue;

        kw_fail:
            for (;i < kwcount; i++) {
                PyStackRef_CLOSE(args[i+argcount]);
            }
            goto fail_post_args;

        kw_found:
            if (PyStackRef_AsPyObjectBorrow(localsplus[j]) != NULL) {
                _PyErr_Format(tstate, PyExc_TypeError,
                            "%U() got multiple values for argument '%S'",
                          func->func_qualname, keyword);
                goto kw_fail;
            }
            localsplus[j] = value_stackref;
        }
    }

    /* Check the number of positional arguments */
    if ((argcount > co->co_argcount) && !(co->co_flags & CO_VARARGS)) {
        too_many_positional(tstate, co, argcount, func->func_defaults, localsplus,
                            func->func_qualname);
        goto fail_post_args;
    }

    /* Add missing positional arguments (copy default values from defs) */
    if (argcount < co->co_argcount) {
        Py_ssize_t defcount = func->func_defaults == NULL ? 0 : PyTuple_GET_SIZE(func->func_defaults);
        Py_ssize_t m = co->co_argcount - defcount;
        Py_ssize_t missing = 0;
        for (i = argcount; i < m; i++) {
            if (PyStackRef_IsNull(localsplus[i])) {
                missing++;
            }
        }
        if (missing) {
            missing_arguments(tstate, co, missing, defcount, localsplus,
                              func->func_qualname);
            goto fail_post_args;
        }
        if (n > m)
            i = n - m;
        else
            i = 0;
        if (defcount) {
            PyObject **defs = &PyTuple_GET_ITEM(func->func_defaults, 0);
            for (; i < defcount; i++) {
                if (PyStackRef_AsPyObjectBorrow(localsplus[m+i]) == NULL) {
                    PyObject *def = defs[i];
                    localsplus[m+i] = PyStackRef_FromPyObjectNew(def);
                }
            }
        }
    }

    /* Add missing keyword arguments (copy default values from kwdefs) */
    if (co->co_kwonlyargcount > 0) {
        Py_ssize_t missing = 0;
        for (i = co->co_argcount; i < total_args; i++) {
            if (PyStackRef_AsPyObjectBorrow(localsplus[i]) != NULL)
                continue;
            PyObject *varname = PyTuple_GET_ITEM(co->co_localsplusnames, i);
            if (func->func_kwdefaults != NULL) {
                PyObject *def;
                if (PyDict_GetItemRef(func->func_kwdefaults, varname, &def) < 0) {
                    goto fail_post_args;
                }
                if (def) {
                    localsplus[i] = PyStackRef_FromPyObjectSteal(def);
                    continue;
                }
            }
            missing++;
        }
        if (missing) {
            missing_arguments(tstate, co, missing, -1, localsplus,
                              func->func_qualname);
            goto fail_post_args;
        }
    }
    return 0;

fail_pre_positional:
    for (j = 0; j < argcount; j++) {
        PyStackRef_CLOSE(args[j]);
    }
    /* fall through */
fail_post_positional:
    if (kwnames) {
        Py_ssize_t kwcount = PyTuple_GET_SIZE(kwnames);
        for (j = argcount; j < argcount+kwcount; j++) {
            PyStackRef_CLOSE(args[j]);
        }
    }
    /* fall through */
fail_post_args:
    return -1;
}

static void
clear_thread_frame(PyThreadState *tstate, _PyInterpreterFrame * frame)
{
    assert(frame->owner == FRAME_OWNED_BY_THREAD);
    // Make sure that this is, indeed, the top frame. We can't check this in
    // _PyThreadState_PopFrame, since f_code is already cleared at that point:
    assert((PyObject **)frame + _PyFrame_GetCode(frame)->co_framesize ==
        tstate->datastack_top);
    tstate->c_recursion_remaining--;
    assert(frame->frame_obj == NULL || frame->frame_obj->f_frame == frame);
    _PyFrame_ClearExceptCode(frame);
    PyStackRef_CLEAR(frame->f_executable);
    tstate->c_recursion_remaining++;
    _PyThreadState_PopFrame(tstate, frame);
}

static void
clear_gen_frame(PyThreadState *tstate, _PyInterpreterFrame * frame)
{
    assert(frame->owner == FRAME_OWNED_BY_GENERATOR);
    PyGenObject *gen = _PyGen_GetGeneratorFromFrame(frame);
    gen->gi_frame_state = FRAME_CLEARED;
    assert(tstate->exc_info == &gen->gi_exc_state);
    tstate->exc_info = gen->gi_exc_state.previous_item;
    gen->gi_exc_state.previous_item = NULL;
    tstate->c_recursion_remaining--;
    assert(frame->frame_obj == NULL || frame->frame_obj->f_frame == frame);
    _PyFrame_ClearExceptCode(frame);
    _PyErr_ClearExcState(&gen->gi_exc_state);
    tstate->c_recursion_remaining++;
    frame->previous = NULL;
}

void
_PyEval_FrameClearAndPop(PyThreadState *tstate, _PyInterpreterFrame * frame)
{
    if (frame->owner == FRAME_OWNED_BY_THREAD) {
        clear_thread_frame(tstate, frame);
    }
    else {
        clear_gen_frame(tstate, frame);
    }
}

/* Consumes references to func, locals and all the args */
_PyInterpreterFrame *
_PyEvalFramePushAndInit(PyThreadState *tstate, _PyStackRef func,
                        PyObject *locals, _PyStackRef const* args,
                        size_t argcount, PyObject *kwnames, _PyInterpreterFrame *previous)
{
    PyFunctionObject *func_obj = (PyFunctionObject *)PyStackRef_AsPyObjectBorrow(func);
    PyCodeObject * code = (PyCodeObject *)func_obj->func_code;
    CALL_STAT_INC(frames_pushed);
    _PyInterpreterFrame *frame = _PyThreadState_PushFrame(tstate, code->co_framesize);
    if (frame == NULL) {
        goto fail;
    }
    _PyFrame_Initialize(tstate, frame, func, locals, code, 0, previous);
    if (initialize_locals(tstate, func_obj, frame->localsplus, args, argcount, kwnames)) {
        assert(frame->owner == FRAME_OWNED_BY_THREAD);
        clear_thread_frame(tstate, frame);
        return NULL;
    }
    return frame;
fail:
    /* Consume the references */
    PyStackRef_CLOSE(func);
    Py_XDECREF(locals);
    for (size_t i = 0; i < argcount; i++) {
        PyStackRef_CLOSE(args[i]);
    }
    if (kwnames) {
        Py_ssize_t kwcount = PyTuple_GET_SIZE(kwnames);
        for (Py_ssize_t i = 0; i < kwcount; i++) {
            PyStackRef_CLOSE(args[i+argcount]);
        }
    }
    PyErr_NoMemory();
    return NULL;
}

static _PyInterpreterFrame *
_PyEvalFramePushAndInit_UnTagged(PyThreadState *tstate, _PyStackRef func,
                        PyObject *locals, PyObject *const* args,
                        size_t argcount, PyObject *kwnames, _PyInterpreterFrame *previous)
{
#if defined(Py_GIL_DISABLED)
    size_t kw_count = kwnames == NULL ? 0 : PyTuple_GET_SIZE(kwnames);
    size_t total_argcount = argcount + kw_count;
    _PyStackRef *tagged_args_buffer = PyMem_Malloc(sizeof(_PyStackRef) * total_argcount);
    if (tagged_args_buffer == NULL) {
        PyErr_NoMemory();
        return NULL;
    }
    for (size_t i = 0; i < argcount; i++) {
        tagged_args_buffer[i] = PyStackRef_FromPyObjectSteal(args[i]);
    }
    for (size_t i = 0; i < kw_count; i++) {
        tagged_args_buffer[argcount + i] = PyStackRef_FromPyObjectSteal(args[argcount + i]);
    }
    _PyInterpreterFrame *res = _PyEvalFramePushAndInit(tstate, func, locals, (_PyStackRef const *)tagged_args_buffer, argcount, kwnames, previous);
    PyMem_Free(tagged_args_buffer);
    return res;
#else
    return _PyEvalFramePushAndInit(tstate, func, locals, (_PyStackRef const *)args, argcount, kwnames, previous);
#endif
}

/* Same as _PyEvalFramePushAndInit but takes an args tuple and kwargs dict.
   Steals references to func, callargs and kwargs.
*/
static _PyInterpreterFrame *
_PyEvalFramePushAndInit_Ex(PyThreadState *tstate, _PyStackRef func,
    PyObject *locals, Py_ssize_t nargs, PyObject *callargs, PyObject *kwargs, _PyInterpreterFrame *previous)
{
    bool has_dict = (kwargs != NULL && PyDict_GET_SIZE(kwargs) > 0);
    PyObject *kwnames = NULL;
    PyObject *const *newargs;
    if (has_dict) {
        newargs = _PyStack_UnpackDict(tstate, _PyTuple_ITEMS(callargs), nargs, kwargs, &kwnames);
        if (newargs == NULL) {
            PyStackRef_CLOSE(func);
            goto error;
        }
    }
    else {
        newargs = &PyTuple_GET_ITEM(callargs, 0);
        /* We need to incref all our args since the new frame steals the references. */
        for (Py_ssize_t i = 0; i < nargs; ++i) {
            Py_INCREF(PyTuple_GET_ITEM(callargs, i));
        }
    }
    _PyInterpreterFrame *new_frame = _PyEvalFramePushAndInit_UnTagged(
        tstate, func, locals,
        newargs, nargs, kwnames, previous
    );
    if (has_dict) {
        _PyStack_UnpackDict_FreeNoDecRef(newargs, kwnames);
    }
    /* No need to decref func here because the reference has been stolen by
       _PyEvalFramePushAndInit.
    */
    Py_DECREF(callargs);
    Py_XDECREF(kwargs);
    return new_frame;
error:
    Py_DECREF(callargs);
    Py_XDECREF(kwargs);
    return NULL;
}

PyObject *
_PyEval_Vector(PyThreadState *tstate, PyFunctionObject *func,
               PyObject *locals,
               PyObject* const* args, size_t argcount,
               PyObject *kwnames)
{
    /* _PyEvalFramePushAndInit consumes the references
     * to func, locals and all its arguments */
    Py_XINCREF(locals);
    for (size_t i = 0; i < argcount; i++) {
        Py_INCREF(args[i]);
    }
    if (kwnames) {
        Py_ssize_t kwcount = PyTuple_GET_SIZE(kwnames);
        for (Py_ssize_t i = 0; i < kwcount; i++) {
            Py_INCREF(args[i+argcount]);
        }
    }
    _PyInterpreterFrame *frame = _PyEvalFramePushAndInit_UnTagged(
        tstate, PyStackRef_FromPyObjectNew(func), locals,
        args, argcount, kwnames, NULL);
    if (frame == NULL) {
        return NULL;
    }
    EVAL_CALL_STAT_INC(EVAL_CALL_VECTOR);
    return _PyEval_EvalFrame(tstate, frame, 0);
}

/* Legacy API */
PyObject *
PyEval_EvalCodeEx(PyObject *_co, PyObject *globals, PyObject *locals,
                  PyObject *const *args, int argcount,
                  PyObject *const *kws, int kwcount,
                  PyObject *const *defs, int defcount,
                  PyObject *kwdefs, PyObject *closure)
{
    PyThreadState *tstate = _PyThreadState_GET();
    PyObject *res = NULL;
    PyObject *defaults = _PyTuple_FromArray(defs, defcount);
    if (defaults == NULL) {
        return NULL;
    }
    PyObject *builtins = _PyDict_LoadBuiltinsFromGlobals(globals);
    if (builtins == NULL) {
        Py_DECREF(defaults);
        return NULL;
    }
    if (locals == NULL) {
        locals = globals;
    }
    PyObject *kwnames = NULL;
    PyObject *const *allargs;
    PyObject **newargs = NULL;
    PyFunctionObject *func = NULL;
    if (kwcount == 0) {
        allargs = args;
    }
    else {
        kwnames = PyTuple_New(kwcount);
        if (kwnames == NULL) {
            goto fail;
        }
        newargs = PyMem_Malloc(sizeof(PyObject *)*(kwcount+argcount));
        if (newargs == NULL) {
            goto fail;
        }
        for (int i = 0; i < argcount; i++) {
            newargs[i] = args[i];
        }
        for (int i = 0; i < kwcount; i++) {
            PyTuple_SET_ITEM(kwnames, i, Py_NewRef(kws[2*i]));
            newargs[argcount+i] = kws[2*i+1];
        }
        allargs = newargs;
    }
    PyFrameConstructor constr = {
        .fc_globals = globals,
        .fc_builtins = builtins,
        .fc_name = ((PyCodeObject *)_co)->co_name,
        .fc_qualname = ((PyCodeObject *)_co)->co_name,
        .fc_code = _co,
        .fc_defaults = defaults,
        .fc_kwdefaults = kwdefs,
        .fc_closure = closure
    };
    func = _PyFunction_FromConstructor(&constr);
    if (func == NULL) {
        goto fail;
    }
    EVAL_CALL_STAT_INC(EVAL_CALL_LEGACY);
    res = _PyEval_Vector(tstate, func, locals,
                         allargs, argcount,
                         kwnames);
fail:
    Py_XDECREF(func);
    Py_XDECREF(kwnames);
    PyMem_Free(newargs);
    _Py_DECREF_BUILTINS(builtins);
    Py_DECREF(defaults);
    return res;
}


/* Logic for the raise statement (too complicated for inlining).
   This *consumes* a reference count to each of its arguments. */
static int
do_raise(PyThreadState *tstate, PyObject *exc, PyObject *cause)
{
    PyObject *type = NULL, *value = NULL;

    if (exc == NULL) {
        /* Reraise */
        _PyErr_StackItem *exc_info = _PyErr_GetTopmostException(tstate);
        exc = exc_info->exc_value;
        if (Py_IsNone(exc) || exc == NULL) {
            _PyErr_SetString(tstate, PyExc_RuntimeError,
                             "No active exception to reraise");
            return 0;
        }
        Py_INCREF(exc);
        assert(PyExceptionInstance_Check(exc));
        _PyErr_SetRaisedException(tstate, exc);
        return 1;
    }

    /* We support the following forms of raise:
       raise
       raise <instance>
       raise <type> */

    if (PyExceptionClass_Check(exc)) {
        type = exc;
        value = _PyObject_CallNoArgs(exc);
        if (value == NULL)
            goto raise_error;
        if (!PyExceptionInstance_Check(value)) {
            _PyErr_Format(tstate, PyExc_TypeError,
                          "calling %R should have returned an instance of "
                          "BaseException, not %R",
                          type, Py_TYPE(value));
             goto raise_error;
        }
    }
    else if (PyExceptionInstance_Check(exc)) {
        value = exc;
        type = PyExceptionInstance_Class(exc);
        Py_INCREF(type);
    }
    else {
        /* Not something you can raise.  You get an exception
           anyway, just not what you specified :-) */
        Py_DECREF(exc);
        _PyErr_SetString(tstate, PyExc_TypeError,
                         "exceptions must derive from BaseException");
        goto raise_error;
    }

    assert(type != NULL);
    assert(value != NULL);

    if (cause) {
        PyObject *fixed_cause;
        if (PyExceptionClass_Check(cause)) {
            fixed_cause = _PyObject_CallNoArgs(cause);
            if (fixed_cause == NULL)
                goto raise_error;
            if (!PyExceptionInstance_Check(fixed_cause)) {
                _PyErr_Format(tstate, PyExc_TypeError,
                              "calling %R should have returned an instance of "
                              "BaseException, not %R",
                              cause, Py_TYPE(fixed_cause));
                goto raise_error;
            }
            Py_DECREF(cause);
        }
        else if (PyExceptionInstance_Check(cause)) {
            fixed_cause = cause;
        }
        else if (Py_IsNone(cause)) {
            Py_DECREF(cause);
            fixed_cause = NULL;
        }
        else {
            _PyErr_SetString(tstate, PyExc_TypeError,
                             "exception causes must derive from "
                             "BaseException");
            goto raise_error;
        }
        PyException_SetCause(value, fixed_cause);
    }

    _PyErr_SetObject(tstate, type, value);
    /* _PyErr_SetObject incref's its arguments */
    Py_DECREF(value);
    Py_DECREF(type);
    return 0;

raise_error:
    Py_XDECREF(value);
    Py_XDECREF(type);
    Py_XDECREF(cause);
    return 0;
}

/* Logic for matching an exception in an except* clause (too
   complicated for inlining).
*/

int
_PyEval_ExceptionGroupMatch(PyObject* exc_value, PyObject *match_type,
                            PyObject **match, PyObject **rest)
{
    if (Py_IsNone(exc_value)) {
        *match = Py_NewRef(Py_None);
        *rest = Py_NewRef(Py_None);
        return 0;
    }
    assert(PyExceptionInstance_Check(exc_value));

    if (PyErr_GivenExceptionMatches(exc_value, match_type)) {
        /* Full match of exc itself */
        bool is_eg = _PyBaseExceptionGroup_Check(exc_value);
        if (is_eg) {
            *match = Py_NewRef(exc_value);
        }
        else {
            /* naked exception - wrap it */
            PyObject *excs = PyTuple_Pack(1, exc_value);
            if (excs == NULL) {
                return -1;
            }
            PyObject *wrapped = _PyExc_CreateExceptionGroup("", excs);
            Py_DECREF(excs);
            if (wrapped == NULL) {
                return -1;
            }
            *match = wrapped;
        }
        *rest = Py_NewRef(Py_None);
        return 0;
    }

    /* exc_value does not match match_type.
     * Check for partial match if it's an exception group.
     */
    if (_PyBaseExceptionGroup_Check(exc_value)) {
        PyObject *pair = PyObject_CallMethod(exc_value, "split", "(O)",
                                             match_type);
        if (pair == NULL) {
            return -1;
        }
        assert(PyTuple_CheckExact(pair));
        assert(PyTuple_GET_SIZE(pair) == 2);
        *match = Py_NewRef(PyTuple_GET_ITEM(pair, 0));
        *rest = Py_NewRef(PyTuple_GET_ITEM(pair, 1));
        Py_DECREF(pair);
        return 0;
    }
    /* no match */
    *match = Py_NewRef(Py_None);
    *rest = Py_NewRef(exc_value);
    return 0;
}

/* Iterate v argcnt times and store the results on the stack (via decreasing
   sp).  Return 1 for success, 0 if error.

   If argcntafter == -1, do a simple unpack. If it is >= 0, do an unpack
   with a variable target.
*/

int
_PyEval_UnpackIterableStackRef(PyThreadState *tstate, _PyStackRef v_stackref,
                       int argcnt, int argcntafter, _PyStackRef *sp)
{
    int i = 0, j = 0;
    Py_ssize_t ll = 0;
    PyObject *it;  /* iter(v) */
    PyObject *w;
    PyObject *l = NULL; /* variable list */

    PyObject *v = PyStackRef_AsPyObjectBorrow(v_stackref);
    assert(v != NULL);

    it = PyObject_GetIter(v);
    if (it == NULL) {
        if (_PyErr_ExceptionMatches(tstate, PyExc_TypeError) &&
            Py_TYPE(v)->tp_iter == NULL && !PySequence_Check(v))
        {
            _PyErr_Format(tstate, PyExc_TypeError,
                          "cannot unpack non-iterable %.200s object",
                          Py_TYPE(v)->tp_name);
        }
        return 0;
    }

    for (; i < argcnt; i++) {
        w = PyIter_Next(it);
        if (w == NULL) {
            /* Iterator done, via error or exhaustion. */
            if (!_PyErr_Occurred(tstate)) {
                if (argcntafter == -1) {
                    _PyErr_Format(tstate, PyExc_ValueError,
                                  "not enough values to unpack "
                                  "(expected %d, got %d)",
                                  argcnt, i);
                }
                else {
                    _PyErr_Format(tstate, PyExc_ValueError,
                                  "not enough values to unpack "
                                  "(expected at least %d, got %d)",
                                  argcnt + argcntafter, i);
                }
            }
            goto Error;
        }
        *--sp = PyStackRef_FromPyObjectSteal(w);
    }

    if (argcntafter == -1) {
        /* We better have exhausted the iterator now. */
        w = PyIter_Next(it);
        if (w == NULL) {
            if (_PyErr_Occurred(tstate))
                goto Error;
            Py_DECREF(it);
            return 1;
        }
        Py_DECREF(w);

        if (PyList_CheckExact(v) || PyTuple_CheckExact(v)
              || PyDict_CheckExact(v)) {
            ll = PyDict_CheckExact(v) ? PyDict_Size(v) : Py_SIZE(v);
            if (ll > argcnt) {
                _PyErr_Format(tstate, PyExc_ValueError,
                              "too many values to unpack (expected %d, got %zd)",
                              argcnt, ll);
                goto Error;
            }
        }
        _PyErr_Format(tstate, PyExc_ValueError,
                      "too many values to unpack (expected %d)",
                      argcnt);
        goto Error;
    }

    l = PySequence_List(it);
    if (l == NULL)
        goto Error;
    *--sp = PyStackRef_FromPyObjectSteal(l);
    i++;

    ll = PyList_GET_SIZE(l);
    if (ll < argcntafter) {
        _PyErr_Format(tstate, PyExc_ValueError,
            "not enough values to unpack (expected at least %d, got %zd)",
            argcnt + argcntafter, argcnt + ll);
        goto Error;
    }

    /* Pop the "after-variable" args off the list. */
    for (j = argcntafter; j > 0; j--, i++) {
        *--sp = PyStackRef_FromPyObjectSteal(PyList_GET_ITEM(l, ll - j));
    }
    /* Resize the list. */
    Py_SET_SIZE(l, ll - argcntafter);
    Py_DECREF(it);
    return 1;

Error:
    for (; i > 0; i--, sp++) {
        PyStackRef_CLOSE(*sp);
    }
    Py_XDECREF(it);
    return 0;
}

static int
do_monitor_exc(PyThreadState *tstate, _PyInterpreterFrame *frame,
               _Py_CODEUNIT *instr, int event)
{
    assert(event < _PY_MONITORING_UNGROUPED_EVENTS);
    if (_PyFrame_GetCode(frame)->co_flags & CO_NO_MONITORING_EVENTS) {
        return 0;
    }
    PyObject *exc = PyErr_GetRaisedException();
    assert(exc != NULL);
    int err = _Py_call_instrumentation_arg(tstate, event, frame, instr, exc);
    if (err == 0) {
        PyErr_SetRaisedException(exc);
    }
    else {
        assert(PyErr_Occurred());
        Py_DECREF(exc);
    }
    return err;
}

static inline bool
no_tools_for_global_event(PyThreadState *tstate, int event)
{
    return tstate->interp->monitors.tools[event] == 0;
}

static inline bool
no_tools_for_local_event(PyThreadState *tstate, _PyInterpreterFrame *frame, int event)
{
    assert(event < _PY_MONITORING_LOCAL_EVENTS);
    _PyCoMonitoringData *data = _PyFrame_GetCode(frame)->_co_monitoring;
    if (data) {
        return data->active_monitors.tools[event] == 0;
    }
    else {
        return no_tools_for_global_event(tstate, event);
    }
}

void
_PyEval_MonitorRaise(PyThreadState *tstate, _PyInterpreterFrame *frame,
              _Py_CODEUNIT *instr)
{
    if (no_tools_for_global_event(tstate, PY_MONITORING_EVENT_RAISE)) {
        return;
    }
    do_monitor_exc(tstate, frame, instr, PY_MONITORING_EVENT_RAISE);
}

static void
monitor_reraise(PyThreadState *tstate, _PyInterpreterFrame *frame,
              _Py_CODEUNIT *instr)
{
    if (no_tools_for_global_event(tstate, PY_MONITORING_EVENT_RERAISE)) {
        return;
    }
    do_monitor_exc(tstate, frame, instr, PY_MONITORING_EVENT_RERAISE);
}

static int
monitor_stop_iteration(PyThreadState *tstate, _PyInterpreterFrame *frame,
                       _Py_CODEUNIT *instr, PyObject *value)
{
    if (no_tools_for_local_event(tstate, frame, PY_MONITORING_EVENT_STOP_ITERATION)) {
        return 0;
    }
    assert(!PyErr_Occurred());
    PyErr_SetObject(PyExc_StopIteration, value);
    int res = do_monitor_exc(tstate, frame, instr, PY_MONITORING_EVENT_STOP_ITERATION);
    if (res < 0) {
        return res;
    }
    PyErr_SetRaisedException(NULL);
    return 0;
}

static void
monitor_unwind(PyThreadState *tstate,
               _PyInterpreterFrame *frame,
               _Py_CODEUNIT *instr)
{
    if (no_tools_for_global_event(tstate, PY_MONITORING_EVENT_PY_UNWIND)) {
        return;
    }
    do_monitor_exc(tstate, frame, instr, PY_MONITORING_EVENT_PY_UNWIND);
}


static int
monitor_handled(PyThreadState *tstate,
                _PyInterpreterFrame *frame,
                _Py_CODEUNIT *instr, PyObject *exc)
{
    if (no_tools_for_global_event(tstate, PY_MONITORING_EVENT_EXCEPTION_HANDLED)) {
        return 0;
    }
    return _Py_call_instrumentation_arg(tstate, PY_MONITORING_EVENT_EXCEPTION_HANDLED, frame, instr, exc);
}

static void
monitor_throw(PyThreadState *tstate,
              _PyInterpreterFrame *frame,
              _Py_CODEUNIT *instr)
{
    if (no_tools_for_global_event(tstate, PY_MONITORING_EVENT_PY_THROW)) {
        return;
    }
    do_monitor_exc(tstate, frame, instr, PY_MONITORING_EVENT_PY_THROW);
}

void
PyThreadState_EnterTracing(PyThreadState *tstate)
{
    assert(tstate->tracing >= 0);
    tstate->tracing++;
}

void
PyThreadState_LeaveTracing(PyThreadState *tstate)
{
    assert(tstate->tracing > 0);
    tstate->tracing--;
}


PyObject*
_PyEval_CallTracing(PyObject *func, PyObject *args)
{
    // Save and disable tracing
    PyThreadState *tstate = _PyThreadState_GET();
    int save_tracing = tstate->tracing;
    tstate->tracing = 0;

    // Call the tracing function
    PyObject *result = PyObject_Call(func, args, NULL);

    // Restore tracing
    tstate->tracing = save_tracing;
    return result;
}

void
PyEval_SetProfile(Py_tracefunc func, PyObject *arg)
{
    PyThreadState *tstate = _PyThreadState_GET();
    if (_PyEval_SetProfile(tstate, func, arg) < 0) {
        /* Log _PySys_Audit() error */
        PyErr_FormatUnraisable("Exception ignored in PyEval_SetProfile");
    }
}

void
PyEval_SetProfileAllThreads(Py_tracefunc func, PyObject *arg)
{
    PyThreadState *this_tstate = _PyThreadState_GET();
    PyInterpreterState* interp = this_tstate->interp;

    _PyRuntimeState *runtime = &_PyRuntime;
    HEAD_LOCK(runtime);
    PyThreadState* ts = PyInterpreterState_ThreadHead(interp);
    HEAD_UNLOCK(runtime);

    while (ts) {
        if (_PyEval_SetProfile(ts, func, arg) < 0) {
            PyErr_FormatUnraisable("Exception ignored in PyEval_SetProfileAllThreads");
        }
        HEAD_LOCK(runtime);
        ts = PyThreadState_Next(ts);
        HEAD_UNLOCK(runtime);
    }
}

void
PyEval_SetTrace(Py_tracefunc func, PyObject *arg)
{
    PyThreadState *tstate = _PyThreadState_GET();
    if (_PyEval_SetTrace(tstate, func, arg) < 0) {
        /* Log _PySys_Audit() error */
        PyErr_FormatUnraisable("Exception ignored in PyEval_SetTrace");
    }
}

void
PyEval_SetTraceAllThreads(Py_tracefunc func, PyObject *arg)
{
    PyThreadState *this_tstate = _PyThreadState_GET();
    PyInterpreterState* interp = this_tstate->interp;

    _PyRuntimeState *runtime = &_PyRuntime;
    HEAD_LOCK(runtime);
    PyThreadState* ts = PyInterpreterState_ThreadHead(interp);
    HEAD_UNLOCK(runtime);

    while (ts) {
        if (_PyEval_SetTrace(ts, func, arg) < 0) {
            PyErr_FormatUnraisable("Exception ignored in PyEval_SetTraceAllThreads");
        }
        HEAD_LOCK(runtime);
        ts = PyThreadState_Next(ts);
        HEAD_UNLOCK(runtime);
    }
}

int
_PyEval_SetCoroutineOriginTrackingDepth(int depth)
{
    PyThreadState *tstate = _PyThreadState_GET();
    if (depth < 0) {
        _PyErr_SetString(tstate, PyExc_ValueError, "depth must be >= 0");
        return -1;
    }
    tstate->coroutine_origin_tracking_depth = depth;
    return 0;
}


int
_PyEval_GetCoroutineOriginTrackingDepth(void)
{
    PyThreadState *tstate = _PyThreadState_GET();
    return tstate->coroutine_origin_tracking_depth;
}

int
_PyEval_SetAsyncGenFirstiter(PyObject *firstiter)
{
    PyThreadState *tstate = _PyThreadState_GET();

    if (_PySys_Audit(tstate, "sys.set_asyncgen_hook_firstiter", NULL) < 0) {
        return -1;
    }

    Py_XSETREF(tstate->async_gen_firstiter, Py_XNewRef(firstiter));
    return 0;
}

PyObject *
_PyEval_GetAsyncGenFirstiter(void)
{
    PyThreadState *tstate = _PyThreadState_GET();
    return tstate->async_gen_firstiter;
}

int
_PyEval_SetAsyncGenFinalizer(PyObject *finalizer)
{
    PyThreadState *tstate = _PyThreadState_GET();

    if (_PySys_Audit(tstate, "sys.set_asyncgen_hook_finalizer", NULL) < 0) {
        return -1;
    }

    Py_XSETREF(tstate->async_gen_finalizer, Py_XNewRef(finalizer));
    return 0;
}

PyObject *
_PyEval_GetAsyncGenFinalizer(void)
{
    PyThreadState *tstate = _PyThreadState_GET();
    return tstate->async_gen_finalizer;
}

_PyInterpreterFrame *
_PyEval_GetFrame(void)
{
    PyThreadState *tstate = _PyThreadState_GET();
    return _PyThreadState_GetFrame(tstate);
}

PyFrameObject *
PyEval_GetFrame(void)
{
    _PyInterpreterFrame *frame = _PyEval_GetFrame();
    if (frame == NULL) {
        return NULL;
    }
    PyFrameObject *f = _PyFrame_GetFrameObject(frame);
    if (f == NULL) {
        PyErr_Clear();
    }
    return f;
}

PyObject *
_PyEval_GetBuiltins(PyThreadState *tstate)
{
    _PyInterpreterFrame *frame = _PyThreadState_GetFrame(tstate);
    if (frame != NULL) {
        return frame->f_builtins;
    }
    return tstate->interp->builtins;
}

PyObject *
PyEval_GetBuiltins(void)
{
    PyThreadState *tstate = _PyThreadState_GET();
    return _PyEval_GetBuiltins(tstate);
}

/* Convenience function to get a builtin from its name */
PyObject *
_PyEval_GetBuiltin(PyObject *name)
{
    PyObject *attr;
    if (PyMapping_GetOptionalItem(PyEval_GetBuiltins(), name, &attr) == 0) {
        PyErr_SetObject(PyExc_AttributeError, name);
    }
    return attr;
}

PyObject *
_PyEval_GetBuiltinId(_Py_Identifier *name)
{
    return _PyEval_GetBuiltin(_PyUnicode_FromId(name));
}

PyObject *
PyEval_GetLocals(void)
{
    // We need to return a borrowed reference here, so some tricks are needed
    PyThreadState *tstate = _PyThreadState_GET();
     _PyInterpreterFrame *current_frame = _PyThreadState_GetFrame(tstate);
    if (current_frame == NULL) {
        _PyErr_SetString(tstate, PyExc_SystemError, "frame does not exist");
        return NULL;
    }

    // Be aware that this returns a new reference
    PyObject *locals = _PyFrame_GetLocals(current_frame);

    if (locals == NULL) {
        return NULL;
    }

    if (PyFrameLocalsProxy_Check(locals)) {
        PyFrameObject *f = _PyFrame_GetFrameObject(current_frame);
        PyObject *ret = f->f_locals_cache;
        if (ret == NULL) {
            ret = PyDict_New();
            if (ret == NULL) {
                Py_DECREF(locals);
                return NULL;
            }
            f->f_locals_cache = ret;
        }
        if (PyDict_Update(ret, locals) < 0) {
            // At this point, if the cache dict is broken, it will stay broken, as
            // trying to clean it up or replace it will just cause other problems
            ret = NULL;
        }
        Py_DECREF(locals);
        return ret;
    }

    assert(PyMapping_Check(locals));
    assert(Py_REFCNT(locals) > 1);
    Py_DECREF(locals);

    return locals;
}

PyObject *
_PyEval_GetFrameLocals(void)
{
    PyThreadState *tstate = _PyThreadState_GET();
     _PyInterpreterFrame *current_frame = _PyThreadState_GetFrame(tstate);
    if (current_frame == NULL) {
        _PyErr_SetString(tstate, PyExc_SystemError, "frame does not exist");
        return NULL;
    }

    PyObject *locals = _PyFrame_GetLocals(current_frame);
    if (locals == NULL) {
        return NULL;
    }

    if (PyFrameLocalsProxy_Check(locals)) {
        PyObject* ret = PyDict_New();
        if (ret == NULL) {
            Py_DECREF(locals);
            return NULL;
        }
        if (PyDict_Update(ret, locals) < 0) {
            Py_DECREF(ret);
            Py_DECREF(locals);
            return NULL;
        }
        Py_DECREF(locals);
        return ret;
    }

    assert(PyMapping_Check(locals));
    return locals;
}

PyObject *
PyEval_GetGlobals(void)
{
    PyThreadState *tstate = _PyThreadState_GET();
    _PyInterpreterFrame *current_frame = _PyThreadState_GetFrame(tstate);
    if (current_frame == NULL) {
        return NULL;
    }
    return current_frame->f_globals;
}

PyObject*
PyEval_GetFrameLocals(void)
{
    return _PyEval_GetFrameLocals();
}

PyObject* PyEval_GetFrameGlobals(void)
{
    PyThreadState *tstate = _PyThreadState_GET();
    _PyInterpreterFrame *current_frame = _PyThreadState_GetFrame(tstate);
    if (current_frame == NULL) {
        return NULL;
    }
    return Py_XNewRef(current_frame->f_globals);
}

PyObject* PyEval_GetFrameBuiltins(void)
{
    PyThreadState *tstate = _PyThreadState_GET();
    return Py_XNewRef(_PyEval_GetBuiltins(tstate));
}

int
PyEval_MergeCompilerFlags(PyCompilerFlags *cf)
{
    PyThreadState *tstate = _PyThreadState_GET();
    _PyInterpreterFrame *current_frame = tstate->current_frame;
    int result = cf->cf_flags != 0;

    if (current_frame != NULL) {
        const int codeflags = _PyFrame_GetCode(current_frame)->co_flags;
        const int compilerflags = codeflags & PyCF_MASK;
        if (compilerflags) {
            result = 1;
            cf->cf_flags |= compilerflags;
        }
    }
    return result;
}


const char *
PyEval_GetFuncName(PyObject *func)
{
    if (PyMethod_Check(func))
        return PyEval_GetFuncName(PyMethod_GET_FUNCTION(func));
    else if (PyFunction_Check(func))
        return PyUnicode_AsUTF8(((PyFunctionObject*)func)->func_name);
    else if (PyCFunction_Check(func))
        return ((PyCFunctionObject*)func)->m_ml->ml_name;
    else
        return Py_TYPE(func)->tp_name;
}

const char *
PyEval_GetFuncDesc(PyObject *func)
{
    if (PyMethod_Check(func))
        return "()";
    else if (PyFunction_Check(func))
        return "()";
    else if (PyCFunction_Check(func))
        return "()";
    else
        return " object";
}

/* Extract a slice index from a PyLong or an object with the
   nb_index slot defined, and store in *pi.
   Silently reduce values larger than PY_SSIZE_T_MAX to PY_SSIZE_T_MAX,
   and silently boost values less than PY_SSIZE_T_MIN to PY_SSIZE_T_MIN.
   Return 0 on error, 1 on success.
*/
int
_PyEval_SliceIndex(PyObject *v, Py_ssize_t *pi)
{
    PyThreadState *tstate = _PyThreadState_GET();
    if (!Py_IsNone(v)) {
        Py_ssize_t x;
        if (_PyIndex_Check(v)) {
            x = PyNumber_AsSsize_t(v, NULL);
            if (x == -1 && _PyErr_Occurred(tstate))
                return 0;
        }
        else {
            _PyErr_SetString(tstate, PyExc_TypeError,
                             "slice indices must be integers or "
                             "None or have an __index__ method");
            return 0;
        }
        *pi = x;
    }
    return 1;
}

int
_PyEval_SliceIndexNotNone(PyObject *v, Py_ssize_t *pi)
{
    PyThreadState *tstate = _PyThreadState_GET();
    Py_ssize_t x;
    if (_PyIndex_Check(v)) {
        x = PyNumber_AsSsize_t(v, NULL);
        if (x == -1 && _PyErr_Occurred(tstate))
            return 0;
    }
    else {
        _PyErr_SetString(tstate, PyExc_TypeError,
                         "slice indices must be integers or "
                         "have an __index__ method");
        return 0;
    }
    *pi = x;
    return 1;
}

PyObject *
_PyEval_ImportName(PyThreadState *tstate, _PyInterpreterFrame *frame,
            PyObject *name, PyObject *fromlist, PyObject *level)
{
    PyObject *import_func;
    if (PyMapping_GetOptionalItem(frame->f_builtins, &_Py_ID(__import__), &import_func) < 0) {
        return NULL;
    }
    if (import_func == NULL) {
        _PyErr_SetString(tstate, PyExc_ImportError, "__import__ not found");
        return NULL;
    }

    PyObject *locals = frame->f_locals;
    if (locals == NULL) {
        locals = Py_None;
    }

    /* Fast path for not overloaded __import__. */
    if (_PyImport_IsDefaultImportFunc(tstate->interp, import_func)) {
        Py_DECREF(import_func);
        int ilevel = PyLong_AsInt(level);
        if (ilevel == -1 && _PyErr_Occurred(tstate)) {
            return NULL;
        }
        return PyImport_ImportModuleLevelObject(
                        name,
                        frame->f_globals,
                        locals,
                        fromlist,
                        ilevel);
    }

    PyObject* args[5] = {name, frame->f_globals, locals, fromlist, level};
    PyObject *res = PyObject_Vectorcall(import_func, args, 5, NULL);
    Py_DECREF(import_func);
    return res;
}

PyObject *
_PyEval_ImportFrom(PyThreadState *tstate, PyObject *v, PyObject *name)
{
    PyObject *x;
    PyObject *fullmodname, *mod_name, *origin, *mod_name_or_unknown, *errmsg, *spec;

    if (PyObject_GetOptionalAttr(v, name, &x) != 0) {
        return x;
    }
    /* Issue #17636: in case this failed because of a circular relative
       import, try to fallback on reading the module directly from
       sys.modules. */
    if (PyObject_GetOptionalAttr(v, &_Py_ID(__name__), &mod_name) < 0) {
        return NULL;
    }
    if (mod_name == NULL || !PyUnicode_Check(mod_name)) {
        Py_CLEAR(mod_name);
        goto error;
    }
    fullmodname = PyUnicode_FromFormat("%U.%U", mod_name, name);
    if (fullmodname == NULL) {
        Py_DECREF(mod_name);
        return NULL;
    }
    x = PyImport_GetModule(fullmodname);
    Py_DECREF(fullmodname);
    if (x == NULL && !_PyErr_Occurred(tstate)) {
        goto error;
    }
    Py_DECREF(mod_name);
    return x;

 error:
    if (mod_name == NULL) {
        mod_name_or_unknown = PyUnicode_FromString("<unknown module name>");
        if (mod_name_or_unknown == NULL) {
            return NULL;
        }
    } else {
        mod_name_or_unknown = mod_name;
    }
    // mod_name is no longer an owned reference
    assert(mod_name_or_unknown);
    assert(mod_name == NULL || mod_name == mod_name_or_unknown);

    origin = NULL;
    if (PyObject_GetOptionalAttr(v, &_Py_ID(__spec__), &spec) < 0) {
        Py_DECREF(mod_name_or_unknown);
        return NULL;
    }
    if (spec == NULL) {
        errmsg = PyUnicode_FromFormat(
            "cannot import name %R from %R (unknown location)",
            name, mod_name_or_unknown
        );
        goto done_with_errmsg;
    }
    if (_PyModuleSpec_GetFileOrigin(spec, &origin) < 0) {
        goto done;
    }

    int is_possibly_shadowing = _PyModule_IsPossiblyShadowing(origin);
    if (is_possibly_shadowing < 0) {
        goto done;
    }
    int is_possibly_shadowing_stdlib = 0;
    if (is_possibly_shadowing) {
        PyObject *stdlib_modules = PySys_GetObject("stdlib_module_names");
        if (stdlib_modules && PyAnySet_Check(stdlib_modules)) {
            is_possibly_shadowing_stdlib = PySet_Contains(stdlib_modules, mod_name_or_unknown);
            if (is_possibly_shadowing_stdlib < 0) {
                goto done;
            }
        }
    }

    if (is_possibly_shadowing_stdlib) {
        assert(origin);
        errmsg = PyUnicode_FromFormat(
            "cannot import name %R from %R "
            "(consider renaming %R since it has the same "
            "name as the standard library module named %R "
            "and prevents importing that standard library module)",
            name, mod_name_or_unknown, origin, mod_name_or_unknown
        );
    }
    else {
        int rc = _PyModuleSpec_IsInitializing(spec);
        if (rc < 0) {
            goto done;
        }
        else if (rc > 0) {
            if (is_possibly_shadowing) {
                assert(origin);
                // For non-stdlib modules, only mention the possibility of
                // shadowing if the module is being initialized.
                errmsg = PyUnicode_FromFormat(
                    "cannot import name %R from %R "
                    "(consider renaming %R if it has the same name "
                    "as a library you intended to import)",
                    name, mod_name_or_unknown, origin
                );
            }
            else if (origin) {
                errmsg = PyUnicode_FromFormat(
                    "cannot import name %R from partially initialized module %R "
                    "(most likely due to a circular import) (%S)",
                    name, mod_name_or_unknown, origin
                );
            }
            else {
                errmsg = PyUnicode_FromFormat(
                    "cannot import name %R from partially initialized module %R "
                    "(most likely due to a circular import)",
                    name, mod_name_or_unknown
                );
            }
        }
        else {
            assert(rc == 0);
            if (origin) {
                errmsg = PyUnicode_FromFormat(
                    "cannot import name %R from %R (%S)",
                    name, mod_name_or_unknown, origin
                );
            }
            else {
                errmsg = PyUnicode_FromFormat(
                    "cannot import name %R from %R (unknown location)",
                    name, mod_name_or_unknown
                );
            }
        }
    }

done_with_errmsg:
    /* NULL checks for errmsg, mod_name, origin done by PyErr_SetImportError. */
    _PyErr_SetImportErrorWithNameFrom(errmsg, mod_name, origin, name);
    Py_DECREF(errmsg);

done:
    Py_XDECREF(origin);
    Py_XDECREF(spec);
    Py_DECREF(mod_name_or_unknown);
    return NULL;
}

#define CANNOT_CATCH_MSG "catching classes that do not inherit from "\
                         "BaseException is not allowed"

#define CANNOT_EXCEPT_STAR_EG "catching ExceptionGroup with except* "\
                              "is not allowed. Use except instead."

int
_PyEval_CheckExceptTypeValid(PyThreadState *tstate, PyObject* right)
{
    if (PyTuple_Check(right)) {
        Py_ssize_t i, length;
        length = PyTuple_GET_SIZE(right);
        for (i = 0; i < length; i++) {
            PyObject *exc = PyTuple_GET_ITEM(right, i);
            if (!PyExceptionClass_Check(exc)) {
                _PyErr_SetString(tstate, PyExc_TypeError,
                    CANNOT_CATCH_MSG);
                return -1;
            }
        }
    }
    else {
        if (!PyExceptionClass_Check(right)) {
            _PyErr_SetString(tstate, PyExc_TypeError,
                CANNOT_CATCH_MSG);
            return -1;
        }
    }
    return 0;
}

int
_PyEval_CheckExceptStarTypeValid(PyThreadState *tstate, PyObject* right)
{
    if (_PyEval_CheckExceptTypeValid(tstate, right) < 0) {
        return -1;
    }

    /* reject except *ExceptionGroup */

    int is_subclass = 0;
    if (PyTuple_Check(right)) {
        Py_ssize_t length = PyTuple_GET_SIZE(right);
        for (Py_ssize_t i = 0; i < length; i++) {
            PyObject *exc = PyTuple_GET_ITEM(right, i);
            is_subclass = PyObject_IsSubclass(exc, PyExc_BaseExceptionGroup);
            if (is_subclass < 0) {
                return -1;
            }
            if (is_subclass) {
                break;
            }
        }
    }
    else {
        is_subclass = PyObject_IsSubclass(right, PyExc_BaseExceptionGroup);
        if (is_subclass < 0) {
            return -1;
        }
    }
    if (is_subclass) {
        _PyErr_SetString(tstate, PyExc_TypeError,
            CANNOT_EXCEPT_STAR_EG);
            return -1;
    }
    return 0;
}

int
_Py_Check_ArgsIterable(PyThreadState *tstate, PyObject *func, PyObject *args)
{
    if (Py_TYPE(args)->tp_iter == NULL && !PySequence_Check(args)) {
        /* _Py_Check_ArgsIterable() may be called with a live exception:
         * clear it to prevent calling _PyObject_FunctionStr() with an
         * exception set. */
        _PyErr_Clear(tstate);
        PyObject *funcstr = _PyObject_FunctionStr(func);
        if (funcstr != NULL) {
            _PyErr_Format(tstate, PyExc_TypeError,
                          "%U argument after * must be an iterable, not %.200s",
                          funcstr, Py_TYPE(args)->tp_name);
            Py_DECREF(funcstr);
        }
        return -1;
    }
    return 0;
}

void
_PyEval_FormatKwargsError(PyThreadState *tstate, PyObject *func, PyObject *kwargs)
{
    /* _PyDict_MergeEx raises attribute
     * error (percolated from an attempt
     * to get 'keys' attribute) instead of
     * a type error if its second argument
     * is not a mapping.
     */
    if (_PyErr_ExceptionMatches(tstate, PyExc_AttributeError)) {
        _PyErr_Clear(tstate);
        PyObject *funcstr = _PyObject_FunctionStr(func);
        if (funcstr != NULL) {
            _PyErr_Format(
                tstate, PyExc_TypeError,
                "%U argument after ** must be a mapping, not %.200s",
                funcstr, Py_TYPE(kwargs)->tp_name);
            Py_DECREF(funcstr);
        }
    }
    else if (_PyErr_ExceptionMatches(tstate, PyExc_KeyError)) {
        PyObject *exc = _PyErr_GetRaisedException(tstate);
        PyObject *args = ((PyBaseExceptionObject *)exc)->args;
        if (exc && PyTuple_Check(args) && PyTuple_GET_SIZE(args) == 1) {
            _PyErr_Clear(tstate);
            PyObject *funcstr = _PyObject_FunctionStr(func);
            if (funcstr != NULL) {
                PyObject *key = PyTuple_GET_ITEM(args, 0);
                _PyErr_Format(
                    tstate, PyExc_TypeError,
                    "%U got multiple values for keyword argument '%S'",
                    funcstr, key);
                Py_DECREF(funcstr);
            }
            Py_XDECREF(exc);
        }
        else {
            _PyErr_SetRaisedException(tstate, exc);
        }
    }
}

void
_PyEval_FormatExcCheckArg(PyThreadState *tstate, PyObject *exc,
                          const char *format_str, PyObject *obj)
{
    const char *obj_str;

    if (!obj)
        return;

    obj_str = PyUnicode_AsUTF8(obj);
    if (!obj_str)
        return;

    _PyErr_Format(tstate, exc, format_str, obj_str);

    if (exc == PyExc_NameError) {
        // Include the name in the NameError exceptions to offer suggestions later.
        PyObject *exc = PyErr_GetRaisedException();
        if (PyErr_GivenExceptionMatches(exc, PyExc_NameError)) {
            if (((PyNameErrorObject*)exc)->name == NULL) {
                // We do not care if this fails because we are going to restore the
                // NameError anyway.
                (void)PyObject_SetAttr(exc, &_Py_ID(name), obj);
            }
        }
        PyErr_SetRaisedException(exc);
    }
}

void
_PyEval_FormatExcUnbound(PyThreadState *tstate, PyCodeObject *co, int oparg)
{
    PyObject *name;
    /* Don't stomp existing exception */
    if (_PyErr_Occurred(tstate))
        return;
    name = PyTuple_GET_ITEM(co->co_localsplusnames, oparg);
    if (oparg < PyUnstable_Code_GetFirstFree(co)) {
        _PyEval_FormatExcCheckArg(tstate, PyExc_UnboundLocalError,
                                  UNBOUNDLOCAL_ERROR_MSG, name);
    } else {
        _PyEval_FormatExcCheckArg(tstate, PyExc_NameError,
                                  UNBOUNDFREE_ERROR_MSG, name);
    }
}

void
_PyEval_FormatAwaitableError(PyThreadState *tstate, PyTypeObject *type, int oparg)
{
    if (type->tp_as_async == NULL || type->tp_as_async->am_await == NULL) {
        if (oparg == 1) {
            _PyErr_Format(tstate, PyExc_TypeError,
                          "'async with' received an object from __aenter__ "
                          "that does not implement __await__: %.100s",
                          type->tp_name);
        }
        else if (oparg == 2) {
            _PyErr_Format(tstate, PyExc_TypeError,
                          "'async with' received an object from __aexit__ "
                          "that does not implement __await__: %.100s",
                          type->tp_name);
        }
    }
}


Py_ssize_t
PyUnstable_Eval_RequestCodeExtraIndex(freefunc free)
{
    PyInterpreterState *interp = _PyInterpreterState_GET();
    Py_ssize_t new_index;

    if (interp->co_extra_user_count == MAX_CO_EXTRA_USERS - 1) {
        return -1;
    }
    new_index = interp->co_extra_user_count++;
    interp->co_extra_freefuncs[new_index] = free;
    return new_index;
}

/* Implement Py_EnterRecursiveCall() and Py_LeaveRecursiveCall() as functions
   for the limited API. */

int Py_EnterRecursiveCall(const char *where)
{
    return _Py_EnterRecursiveCall(where);
}

void Py_LeaveRecursiveCall(void)
{
    _Py_LeaveRecursiveCall();
}

PyObject *
_PyEval_GetANext(PyObject *aiter)
{
    unaryfunc getter = NULL;
    PyObject *next_iter = NULL;
    PyTypeObject *type = Py_TYPE(aiter);
    if (PyAsyncGen_CheckExact(aiter)) {
        return type->tp_as_async->am_anext(aiter);
    }
    if (type->tp_as_async != NULL){
        getter = type->tp_as_async->am_anext;
    }

    if (getter != NULL) {
        next_iter = (*getter)(aiter);
        if (next_iter == NULL) {
            return NULL;
        }
    }
    else {
        PyErr_Format(PyExc_TypeError,
                        "'async for' requires an iterator with "
                        "__anext__ method, got %.100s",
                        type->tp_name);
        return NULL;
    }

    PyObject *awaitable = _PyCoro_GetAwaitableIter(next_iter);
    if (awaitable == NULL) {
        _PyErr_FormatFromCause(
            PyExc_TypeError,
            "'async for' received an invalid object "
            "from __anext__: %.100s",
            Py_TYPE(next_iter)->tp_name);
    }
    Py_DECREF(next_iter);
    return awaitable;
}

void
_PyEval_LoadGlobalStackRef(PyObject *globals, PyObject *builtins, PyObject *name, _PyStackRef *writeto)
{
    if (PyDict_CheckExact(globals) && PyDict_CheckExact(builtins)) {
        _PyDict_LoadGlobalStackRef((PyDictObject *)globals,
                                    (PyDictObject *)builtins,
                                    name, writeto);
        if (PyStackRef_IsNull(*writeto) && !PyErr_Occurred()) {
            /* _PyDict_LoadGlobal() returns NULL without raising
                * an exception if the key doesn't exist */
            _PyEval_FormatExcCheckArg(PyThreadState_GET(), PyExc_NameError,
                                        NAME_ERROR_MSG, name);
        }
    }
    else {
        /* Slow-path if globals or builtins is not a dict */
        /* namespace 1: globals */
        PyObject *res;
        if (PyMapping_GetOptionalItem(globals, name, &res) < 0) {
            *writeto = PyStackRef_NULL;
            return;
        }
        if (res == NULL) {
            /* namespace 2: builtins */
            if (PyMapping_GetOptionalItem(builtins, name, &res) < 0) {
                *writeto = PyStackRef_NULL;
                return;
            }
            if (res == NULL) {
                _PyEval_FormatExcCheckArg(
                            PyThreadState_GET(), PyExc_NameError,
                            NAME_ERROR_MSG, name);
            }
        }
        *writeto = PyStackRef_FromPyObjectSteal(res);
    }
}

PyObject *
_PyEval_GetAwaitable(PyObject *iterable, int oparg)
{
    PyObject *iter = _PyCoro_GetAwaitableIter(iterable);

    if (iter == NULL) {
        _PyEval_FormatAwaitableError(PyThreadState_GET(),
            Py_TYPE(iterable), oparg);
    }
    else if (PyCoro_CheckExact(iter)) {
        PyObject *yf = _PyGen_yf((PyGenObject*)iter);
        if (yf != NULL) {
            /* `iter` is a coroutine object that is being
                awaited, `yf` is a pointer to the current awaitable
                being awaited on. */
            Py_DECREF(yf);
            Py_CLEAR(iter);
            _PyErr_SetString(PyThreadState_GET(), PyExc_RuntimeError,
                                "coroutine is being awaited already");
        }
    }
    return iter;
}

PyObject *
_PyEval_LoadName(PyThreadState *tstate, _PyInterpreterFrame *frame, PyObject *name)
{

    PyObject *value;
    if (frame->f_locals == NULL) {
        _PyErr_SetString(tstate, PyExc_SystemError,
                            "no locals found");
        return NULL;
    }
    if (PyMapping_GetOptionalItem(frame->f_locals, name, &value) < 0) {
        return NULL;
    }
    if (value != NULL) {
        return value;
    }
    if (PyDict_GetItemRef(frame->f_globals, name, &value) < 0) {
        return NULL;
    }
    if (value != NULL) {
        return value;
    }
    if (PyMapping_GetOptionalItem(frame->f_builtins, name, &value) < 0) {
        return NULL;
    }
    if (value == NULL) {
        _PyEval_FormatExcCheckArg(
                    tstate, PyExc_NameError,
                    NAME_ERROR_MSG, name);
    }
    return value;
}