/* Generic object operations; and implementation of None */

#include "Python.h"

#include "pycore_ceval.h" // _Py_EnterRecursiveCall()

#include "pycore_context.h"

#include "pycore_initconfig.h"

#include "pycore_object.h"

#include "pycore_pyerrors.h"

#include "pycore_pylifecycle.h"

#include "pycore_pymem.h" // _PyMem_IsPtrFreed()

#include "pycore_pystate.h" // _PyThreadState_GET()

#include "pycore_symtable.h" // PySTEntry_Type

#include "pycore_unionobject.h" // _PyUnion_Type

#include "frameobject.h"

#include "interpreteridobject.h"

#ifdef Py_LIMITED_API

// Prevent recursive call _Py_IncRef() <=> Py_INCREF()

# error "Py_LIMITED_API macro must not be defined"

#endif

#ifdef __cplusplus

extern "C" {

#endif

/* Defined in tracemalloc.c */

extern void _PyMem_DumpTraceback(int fd, const void *ptr);

_Py_IDENTIFIER(Py_Repr);

_Py_IDENTIFIER(__bytes__);

_Py_IDENTIFIER(__dir__);

_Py_IDENTIFIER(__isabstractmethod__);

int

_PyObject_CheckConsistency(PyObject *op, int check_content)

{

#define CHECK(expr) \

do { if (!(expr)) { _PyObject_ASSERT_FAILED_MSG(op, Py_STRINGIFY(expr)); } } while (0)

CHECK(!_PyObject_IsFreed(op));

CHECK(Py_REFCNT(op) >= 1);

_PyType_CheckConsistency(Py_TYPE(op));

if (PyUnicode_Check(op)) {

_PyUnicode_CheckConsistency(op, check_content);

}

else if (PyDict_Check(op)) {

_PyDict_CheckConsistency(op, check_content);

}

return 1;

#undef CHECK

}

#ifdef Py_REF_DEBUG

Py_ssize_t _Py_RefTotal;

Py_ssize_t

_Py_GetRefTotal(void)

{

PyObject *o;

Py_ssize_t total = _Py_RefTotal;

o = _PySet_Dummy;

if (o != NULL)

total -= Py_REFCNT(o);

return total;

}

void

_PyDebug_PrintTotalRefs(void) {

fprintf(stderr,

"[%zd refs, %zd blocks]\n",

_Py_GetRefTotal(), _Py_GetAllocatedBlocks());

}

#endif /* Py_REF_DEBUG */

/* Object allocation routines used by NEWOBJ and NEWVAROBJ macros.

These are used by the individual routines for object creation.

Do not call them otherwise, they do not initialize the object! */

#ifdef Py_TRACE_REFS

/* Head of circular doubly-linked list of all objects. These are linked

* together via the _ob_prev and _ob_next members of a PyObject, which

* exist only in a Py_TRACE_REFS build.

*/

static PyObject refchain = {&refchain, &refchain};

/* Insert op at the front of the list of all objects. If force is true,

* op is added even if _ob_prev and _ob_next are non-NULL already. If

* force is false amd _ob_prev or _ob_next are non-NULL, do nothing.

* force should be true if and only if op points to freshly allocated,

* uninitialized memory, or you've unlinked op from the list and are

* relinking it into the front.

* Note that objects are normally added to the list via _Py_NewReference,

* which is called by PyObject_Init. Not all objects are initialized that

* way, though; exceptions include statically allocated type objects, and

* statically allocated singletons (like Py_True and Py_None).

*/

void

_Py_AddToAllObjects(PyObject *op, int force)

{

#ifdef Py_DEBUG

if (!force) {

/* If it's initialized memory, op must be in or out of

* the list unambiguously.

*/

_PyObject_ASSERT(op, (op->_ob_prev == NULL) == (op->_ob_next == NULL));

}

#endif

if (force || op->_ob_prev == NULL) {

op->_ob_next = refchain._ob_next;

op->_ob_prev = &refchain;

refchain._ob_next->_ob_prev = op;

refchain._ob_next = op;

}

}

#endif /* Py_TRACE_REFS */

#ifdef Py_REF_DEBUG

/* Log a fatal error; doesn't return. */

void

_Py_NegativeRefcount(const char *filename, int lineno, PyObject *op)

{

_PyObject_AssertFailed(op, NULL, "object has negative ref count",

filename, lineno, __func__);

}

#endif /* Py_REF_DEBUG */

void

Py_IncRef(PyObject *o)

{

Py_XINCREF(o);

}

void

Py_DecRef(PyObject *o)

{

Py_XDECREF(o);

}

void

_Py_IncRef(PyObject *o)

{

Py_INCREF(o);

}

void

_Py_DecRef(PyObject *o)

{

Py_DECREF(o);

}

PyObject *

PyObject_Init(PyObject *op, PyTypeObject *tp)

{

if (op == NULL) {

return PyErr_NoMemory();

}

_PyObject_Init(op, tp);

return op;

}

PyVarObject *

PyObject_InitVar(PyVarObject *op, PyTypeObject *tp, Py_ssize_t size)

{

if (op == NULL) {

return (PyVarObject *) PyErr_NoMemory();

}

_PyObject_InitVar(op, tp, size);

return op;

}

PyObject *

_PyObject_New(PyTypeObject *tp)

{

PyObject *op = (PyObject *) PyObject_Malloc(_PyObject_SIZE(tp));

if (op == NULL) {

return PyErr_NoMemory();

}

_PyObject_Init(op, tp);

return op;

}

PyVarObject *

_PyObject_NewVar(PyTypeObject *tp, Py_ssize_t nitems)

{

PyVarObject *op;

const size_t size = _PyObject_VAR_SIZE(tp, nitems);

op = (PyVarObject *) PyObject_Malloc(size);

if (op == NULL) {

return (PyVarObject *)PyErr_NoMemory();

}

_PyObject_InitVar(op, tp, nitems);

return op;

}

void

PyObject_CallFinalizer(PyObject *self)

{

PyTypeObject *tp = Py_TYPE(self);

if (tp->tp_finalize == NULL)

return;

/* tp_finalize should only be called once. */

if (_PyType_IS_GC(tp) && _PyGC_FINALIZED(self))

return;

tp->tp_finalize(self);

if (_PyType_IS_GC(tp)) {

_PyGC_SET_FINALIZED(self);

}

}

int

PyObject_CallFinalizerFromDealloc(PyObject *self)

{

if (Py_REFCNT(self) != 0) {

_PyObject_ASSERT_FAILED_MSG(self,

"PyObject_CallFinalizerFromDealloc called "

"on object with a non-zero refcount");

}

/* Temporarily resurrect the object. */

Py_SET_REFCNT(self, 1);

PyObject_CallFinalizer(self);

_PyObject_ASSERT_WITH_MSG(self,

Py_REFCNT(self) > 0,

"refcount is too small");

/* Undo the temporary resurrection; can't use DECREF here, it would

* cause a recursive call. */

Py_SET_REFCNT(self, Py_REFCNT(self) - 1);

if (Py_REFCNT(self) == 0) {

return 0; /* this is the normal path out */

}

/* tp_finalize resurrected it! Make it look like the original Py_DECREF

* never happened. */

Py_ssize_t refcnt = Py_REFCNT(self);

_Py_NewReference(self);

Py_SET_REFCNT(self, refcnt);

_PyObject_ASSERT(self,

(!_PyType_IS_GC(Py_TYPE(self))

|| _PyObject_GC_IS_TRACKED(self)));

/* If Py_REF_DEBUG macro is defined, _Py_NewReference() increased

_Py_RefTotal, so we need to undo that. */

#ifdef Py_REF_DEBUG

_Py_RefTotal--;

#endif

return -1;

}

int

PyObject_Print(PyObject *op, FILE *fp, int flags)

{

int ret = 0;

if (PyErr_CheckSignals())

return -1;

#ifdef USE_STACKCHECK

if (PyOS_CheckStack()) {

PyErr_SetString(PyExc_MemoryError, "stack overflow");

return -1;

}

#endif

clearerr(fp); /* Clear any previous error condition */

if (op == NULL) {

Py_BEGIN_ALLOW_THREADS

fprintf(fp, "<nil>");

Py_END_ALLOW_THREADS

}

else {

if (Py_REFCNT(op) <= 0) {

/* XXX(twouters) cast refcount to long until %zd is

universally available */

Py_BEGIN_ALLOW_THREADS

fprintf(fp, "<refcnt %ld at %p>",

(long)Py_REFCNT(op), (void *)op);

Py_END_ALLOW_THREADS

}

else {

PyObject *s;

if (flags & Py_PRINT_RAW)

s = PyObject_Str(op);

else

s = PyObject_Repr(op);

if (s == NULL)

ret = -1;

else if (PyBytes_Check(s)) {

fwrite(PyBytes_AS_STRING(s), 1,

PyBytes_GET_SIZE(s), fp);

}

else if (PyUnicode_Check(s)) {

PyObject *t;

t = PyUnicode_AsEncodedString(s, "utf-8", "backslashreplace");

if (t == NULL) {

ret = -1;

}

else {

fwrite(PyBytes_AS_STRING(t), 1,

PyBytes_GET_SIZE(t), fp);

Py_DECREF(t);

}

}

else {

PyErr_Format(PyExc_TypeError,

"str() or repr() returned '%.100s'",

Py_TYPE(s)->tp_name);

ret = -1;

}

Py_XDECREF(s);

}

}

if (ret == 0) {

if (ferror(fp)) {

PyErr_SetFromErrno(PyExc_OSError);

clearerr(fp);

ret = -1;

}

}

return ret;

}

/* For debugging convenience. Set a breakpoint here and call it from your DLL */

void

_Py_BreakPoint(void)

{

}

/* Heuristic checking if the object memory is uninitialized or deallocated.

Rely on the debug hooks on Python memory allocators:

see _PyMem_IsPtrFreed().

The function can be used to prevent segmentation fault on dereferencing

pointers like 0xDDDDDDDDDDDDDDDD. */

int

_PyObject_IsFreed(PyObject *op)

{

if (_PyMem_IsPtrFreed(op) || _PyMem_IsPtrFreed(Py_TYPE(op))) {

return 1;

}

/* ignore op->ob_ref: its value can have be modified

by Py_INCREF() and Py_DECREF(). */

#ifdef Py_TRACE_REFS

if (op->_ob_next != NULL && _PyMem_IsPtrFreed(op->_ob_next)) {

return 1;

}

if (op->_ob_prev != NULL && _PyMem_IsPtrFreed(op->_ob_prev)) {

return 1;

}

#endif

return 0;

}

/* For debugging convenience. See Misc/gdbinit for some useful gdb hooks */

void

_PyObject_Dump(PyObject* op)

{

if (_PyObject_IsFreed(op)) {

/* It seems like the object memory has been freed:

don't access it to prevent a segmentation fault. */

fprintf(stderr, "<object at %p is freed>\n", op);

fflush(stderr);

return;

}

/* first, write fields which are the least likely to crash */

fprintf(stderr, "object address : %p\n", (void *)op);

/* XXX(twouters) cast refcount to long until %zd is

universally available */

fprintf(stderr, "object refcount : %ld\n", (long)Py_REFCNT(op));

fflush(stderr);

PyTypeObject *type = Py_TYPE(op);

fprintf(stderr, "object type : %p\n", type);

fprintf(stderr, "object type name: %s\n",

type==NULL ? "NULL" : type->tp_name);

/* the most dangerous part */

fprintf(stderr, "object repr : ");

fflush(stderr);

PyGILState_STATE gil = PyGILState_Ensure();

PyObject *error_type, *error_value, *error_traceback;

PyErr_Fetch(&error_type, &error_value, &error_traceback);

(void)PyObject_Print(op, stderr, 0);

fflush(stderr);

PyErr_Restore(error_type, error_value, error_traceback);

PyGILState_Release(gil);

fprintf(stderr, "\n");

fflush(stderr);

}

PyObject *

PyObject_Repr(PyObject *v)

{

PyObject *res;

if (PyErr_CheckSignals())

return NULL;

#ifdef USE_STACKCHECK

if (PyOS_CheckStack()) {

PyErr_SetString(PyExc_MemoryError, "stack overflow");

return NULL;

}

#endif

if (v == NULL)

return PyUnicode_FromString("<NULL>");

if (Py_TYPE(v)->tp_repr == NULL)

return PyUnicode_FromFormat("<%s object at %p>",

Py_TYPE(v)->tp_name, v);

PyThreadState *tstate = _PyThreadState_GET();

#ifdef Py_DEBUG

/* PyObject_Repr() 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

/* It is possible for a type to have a tp_repr representation that loops

infinitely. */

if (_Py_EnterRecursiveCall(tstate,

" while getting the repr of an object")) {

return NULL;

}

res = (*Py_TYPE(v)->tp_repr)(v);

_Py_LeaveRecursiveCall(tstate);

if (res == NULL) {

return NULL;

}

if (!PyUnicode_Check(res)) {

_PyErr_Format(tstate, PyExc_TypeError,

"__repr__ returned non-string (type %.200s)",

Py_TYPE(res)->tp_name);

Py_DECREF(res);

return NULL;

}

#ifndef Py_DEBUG

if (PyUnicode_READY(res) < 0) {

return NULL;

}

#endif

return res;

}

PyObject *

PyObject_Str(PyObject *v)

{

PyObject *res;

if (PyErr_CheckSignals())

return NULL;

#ifdef USE_STACKCHECK

if (PyOS_CheckStack()) {

PyErr_SetString(PyExc_MemoryError, "stack overflow");

return NULL;

}

#endif

if (v == NULL)

return PyUnicode_FromString("<NULL>");

if (PyUnicode_CheckExact(v)) {

#ifndef Py_DEBUG

if (PyUnicode_READY(v) < 0)

return NULL;

#endif

Py_INCREF(v);

return v;

}

if (Py_TYPE(v)->tp_str == NULL)

return PyObject_Repr(v);

PyThreadState *tstate = _PyThreadState_GET();

#ifdef Py_DEBUG

/* PyObject_Str() 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

/* It is possible for a type to have a tp_str representation that loops

infinitely. */

if (_Py_EnterRecursiveCall(tstate, " while getting the str of an object")) {

return NULL;

}

res = (*Py_TYPE(v)->tp_str)(v);

_Py_LeaveRecursiveCall(tstate);

if (res == NULL) {

return NULL;

}

if (!PyUnicode_Check(res)) {

_PyErr_Format(tstate, PyExc_TypeError,

"__str__ returned non-string (type %.200s)",

Py_TYPE(res)->tp_name);

Py_DECREF(res);

return NULL;

}

#ifndef Py_DEBUG

if (PyUnicode_READY(res) < 0) {

return NULL;

}

#endif

assert(_PyUnicode_CheckConsistency(res, 1));

return res;

}

PyObject *

PyObject_ASCII(PyObject *v)

{

PyObject *repr, *ascii, *res;

repr = PyObject_Repr(v);

if (repr == NULL)

return NULL;

if (PyUnicode_IS_ASCII(repr))

return repr;

/* repr is guaranteed to be a PyUnicode object by PyObject_Repr */

ascii = _PyUnicode_AsASCIIString(repr, "backslashreplace");

Py_DECREF(repr);

if (ascii == NULL)

return NULL;

res = PyUnicode_DecodeASCII(

PyBytes_AS_STRING(ascii),

PyBytes_GET_SIZE(ascii),

NULL);

Py_DECREF(ascii);

return res;

}

PyObject *

PyObject_Bytes(PyObject *v)

{

PyObject *result, *func;

if (v == NULL)

return PyBytes_FromString("<NULL>");

if (PyBytes_CheckExact(v)) {

Py_INCREF(v);

return v;

}

func = _PyObject_LookupSpecial(v, &PyId___bytes__);

if (func != NULL) {

result = _PyObject_CallNoArgs(func);

Py_DECREF(func);

if (result == NULL)

return NULL;

if (!PyBytes_Check(result)) {

PyErr_Format(PyExc_TypeError,

"__bytes__ returned non-bytes (type %.200s)",

Py_TYPE(result)->tp_name);

Py_DECREF(result);

return NULL;

}

return result;

}

else if (PyErr_Occurred())

return NULL;

return PyBytes_FromObject(v);

}

/*

def _PyObject_FunctionStr(x):

try:

qualname = x.__qualname__

except AttributeError:

return str(x)

try:

mod = x.__module__

if mod is not None and mod != 'builtins':

return f"{x.__module__}.{qualname}()"

except AttributeError:

pass

return qualname

*/

PyObject *

_PyObject_FunctionStr(PyObject *x)

{

_Py_IDENTIFIER(__module__);

_Py_IDENTIFIER(__qualname__);

_Py_IDENTIFIER(builtins);

assert(!PyErr_Occurred());

PyObject *qualname;

int ret = _PyObject_LookupAttrId(x, &PyId___qualname__, &qualname);

if (qualname == NULL) {

if (ret < 0) {

return NULL;

}

return PyObject_Str(x);

}

PyObject *module;

PyObject *result = NULL;

ret = _PyObject_LookupAttrId(x, &PyId___module__, &module);

if (module != NULL && module != Py_None) {

PyObject *builtinsname = _PyUnicode_FromId(&PyId_builtins);

if (builtinsname == NULL) {

goto done;

}

ret = PyObject_RichCompareBool(module, builtinsname, Py_NE);

if (ret < 0) {

// error

goto done;

}

if (ret > 0) {

result = PyUnicode_FromFormat("%S.%S()", module, qualname);

goto done;

}

}

else if (ret < 0) {

goto done;

}

result = PyUnicode_FromFormat("%S()", qualname);

done:

Py_DECREF(qualname);

Py_XDECREF(module);

return result;

}

/* For Python 3.0.1 and later, the old three-way comparison has been

completely removed in favour of rich comparisons. PyObject_Compare() and

PyObject_Cmp() are gone, and the builtin cmp function no longer exists.

The old tp_compare slot has been renamed to tp_as_async, and should no

longer be used. Use tp_richcompare instead.

See (*) below for practical amendments.

tp_richcompare gets called with a first argument of the appropriate type

and a second object of an arbitrary type. We never do any kind of

coercion.

The tp_richcompare slot should return an object, as follows:

NULL if an exception occurred

NotImplemented if the requested comparison is not implemented

any other false value if the requested comparison is false

any other true value if the requested comparison is true

The PyObject_RichCompare[Bool]() wrappers raise TypeError when they get

NotImplemented.

(*) Practical amendments:

- If rich comparison returns NotImplemented, == and != are decided by

comparing the object pointer (i.e. falling back to the base object

implementation).

*/

/* Map rich comparison operators to their swapped version, e.g. LT <--> GT */

int _Py_SwappedOp[] = {Py_GT, Py_GE, Py_EQ, Py_NE, Py_LT, Py_LE};

static const char * const opstrings[] = {"<", "<=", "==", "!=", ">", ">="};

/* Perform a rich comparison, raising TypeError when the requested comparison

operator is not supported. */

static PyObject *

do_richcompare(PyThreadState *tstate, PyObject *v, PyObject *w, int op)

{

richcmpfunc f;

PyObject *res;

int checked_reverse_op = 0;

if (!Py_IS_TYPE(v, Py_TYPE(w)) &&

PyType_IsSubtype(Py_TYPE(w), Py_TYPE(v)) &&

(f = Py_TYPE(w)->tp_richcompare) != NULL) {

checked_reverse_op = 1;

res = (*f)(w, v, _Py_SwappedOp[op]);

if (res != Py_NotImplemented)

return res;

Py_DECREF(res);

}

if ((f = Py_TYPE(v)->tp_richcompare) != NULL) {

res = (*f)(v, w, op);

if (res != Py_NotImplemented)

return res;

Py_DECREF(res);

}

if (!checked_reverse_op && (f = Py_TYPE(w)->tp_richcompare) != NULL) {

res = (*f)(w, v, _Py_SwappedOp[op]);

if (res != Py_NotImplemented)

return res;

Py_DECREF(res);

}

/* If neither object implements it, provide a sensible default

for == and !=, but raise an exception for ordering. */

switch (op) {

case Py_EQ:

res = (v == w) ? Py_True : Py_False;

break;

case Py_NE:

res = (v != w) ? Py_True : Py_False;

break;

default:

_PyErr_Format(tstate, PyExc_TypeError,

"'%s' not supported between instances of '%.100s' and '%.100s'",

opstrings[op],

Py_TYPE(v)->tp_name,

Py_TYPE(w)->tp_name);

return NULL;

}

Py_INCREF(res);

return res;

}

/* Perform a rich comparison with object result. This wraps do_richcompare()

with a check for NULL arguments and a recursion check. */

PyObject *

PyObject_RichCompare(PyObject *v, PyObject *w, int op)

{

PyThreadState *tstate = _PyThreadState_GET();

assert(Py_LT <= op && op <= Py_GE);

if (v == NULL || w == NULL) {

if (!_PyErr_Occurred(tstate)) {

PyErr_BadInternalCall();

}

return NULL;

}

if (_Py_EnterRecursiveCall(tstate, " in comparison")) {

return NULL;

}

PyObject *res = do_richcompare(tstate, v, w, op);

_Py_LeaveRecursiveCall(tstate);

return res;

}

/* Perform a rich comparison with integer result. This wraps

PyObject_RichCompare(), returning -1 for error, 0 for false, 1 for true. */

int

PyObject_RichCompareBool(PyObject *v, PyObject *w, int op)

{

PyObject *res;

int ok;

/* Quick result when objects are the same.

Guarantees that identity implies equality. */

if (v == w) {

if (op == Py_EQ)

return 1;

else if (op == Py_NE)

return 0;

}

res = PyObject_RichCompare(v, w, op);

if (res == NULL)

return -1;

if (PyBool_Check(res))

ok = (res == Py_True);

else

ok = PyObject_IsTrue(res);

Py_DECREF(res);

return ok;

}

Py_hash_t

PyObject_HashNotImplemented(PyObject *v)

{

PyErr_Format(PyExc_TypeError, "unhashable type: '%.200s'",

Py_TYPE(v)->tp_name);

return -1;

}

Py_hash_t

PyObject_Hash(PyObject *v)

{

PyTypeObject *tp = Py_TYPE(v);

if (tp->tp_hash != NULL)

return (*tp->tp_hash)(v);

/* To keep to the general practice that inheriting

* solely from object in C code should work without

* an explicit call to PyType_Ready, we implicitly call

* PyType_Ready here and then check the tp_hash slot again

*/

if (tp->tp_dict == NULL) {

if (PyType_Ready(tp) < 0)

return -1;

if (tp->tp_hash != NULL)

return (*tp->tp_hash)(v);

}

/* Otherwise, the object can't be hashed */

return PyObject_HashNotImplemented(v);

}

PyObject *

PyObject_GetAttrString(PyObject *v, const char *name)

{

PyObject *w, *res;

if (Py_TYPE(v)->tp_getattr != NULL)

return (*Py_TYPE(v)->tp_getattr)(v, (char*)name);

w = PyUnicode_FromString(name);

if (w == NULL)

return NULL;

res = PyObject_GetAttr(v, w);

Py_DECREF(w);

return res;

}

int

PyObject_HasAttrString(PyObject *v, const char *name)

{

PyObject *res = PyObject_GetAttrString(v, name);

if (res != NULL) {

Py_DECREF(res);

return 1;

}

PyErr_Clear();

return 0;

}

int

PyObject_SetAttrString(PyObject *v, const char *name, PyObject *w)

{

PyObject *s;

int res;

if (Py_TYPE(v)->tp_setattr != NULL)

return (*Py_TYPE(v)->tp_setattr)(v, (char*)name, w);

s = PyUnicode_InternFromString(name);

if (s == NULL)

return -1;

res = PyObject_SetAttr(v, s, w);

Py_XDECREF(s);

return res;

}

int

_PyObject_IsAbstract(PyObject *obj)

{

int res;

PyObject* isabstract;

if (obj == NULL)

return 0;

res = _PyObject_LookupAttrId(obj, &PyId___isabstractmethod__, &isabstract);

if (res > 0) {

res = PyObject_IsTrue(isabstract);

Py_DECREF(isabstract);

}

return res;

}

PyObject *

_PyObject_GetAttrId(PyObject *v, _Py_Identifier *name)

{

PyObject *result;

PyObject *oname = _PyUnicode_FromId(name); /* borrowed */

if (!oname)

return NULL;

result = PyObject_GetAttr(v, oname);

return result;

}

int

_PyObject_SetAttrId(PyObject *v, _Py_Identifier *name, PyObject *w)

{

int result;

PyObject *oname = _PyUnicode_FromId(name); /* borrowed */

if (!oname)

return -1;

result = PyObject_SetAttr(v, oname, w);

return result;

}

static inline int

set_attribute_error_context(PyObject* v, PyObject* name)

{

assert(PyErr_Occurred());

_Py_IDENTIFIER(name);

_Py_IDENTIFIER(obj);

// Intercept AttributeError exceptions and augment them to offer

// suggestions later.

if (PyErr_ExceptionMatches(PyExc_AttributeError)){

PyObject *type, *value, *traceback;

PyErr_Fetch(&type, &value, &traceback);

PyErr_NormalizeException(&type, &value, &traceback);

if (PyErr_GivenExceptionMatches(value, PyExc_AttributeError) &&

(_PyObject_SetAttrId(value, &PyId_name, name) ||

_PyObject_SetAttrId(value, &PyId_obj, v))) {

return 1;

}

PyErr_Restore(type, value, traceback);

}

return 0;

}

PyObject *

PyObject_GetAttr(PyObject *v, PyObject *name)

{

PyTypeObject *tp = Py_TYPE(v);

if (!PyUnicode_Check(name)) {

PyErr_Format(PyExc_TypeError,

"attribute name must be string, not '%.200s'",

Py_TYPE(name)->tp_name);

return NULL;

}

PyObject* result = NULL;

if (tp->tp_getattro != NULL) {

result = (*tp->tp_getattro)(v, name);

}

else if (tp->tp_getattr != NULL) {

const char *name_str = PyUnicode_AsUTF8(name);

if (name_str == NULL) {

return NULL;

}

result = (*tp->tp_getattr)(v, (char *)name_str);

}

else {

PyErr_Format(PyExc_AttributeError,

"'%.50s' object has no attribute '%U'",

tp->tp_name, name);

}

if (result == NULL) {

set_attribute_error_context(v, name);

}

return result;

}

int

_PyObject_LookupAttr(PyObject *v, PyObject *name, PyObject **result)

{

PyTypeObject *tp = Py_TYPE(v);

if (!PyUnicode_Check(name)) {

PyErr_Format(PyExc_TypeError,

"attribute name must be string, not '%.200s'",

Py_TYPE(name)->tp_name);

*result = NULL;

return -1;

}

if (tp->tp_getattro == PyObject_GenericGetAttr) {

*result = _PyObject_GenericGetAttrWithDict(v, name, NULL, 1);

if (*result != NULL) {

return 1;

}

if (PyErr_Occurred()) {

return -1;

}

return 0;

}

if (tp->tp_getattro != NULL) {

*result = (*tp->tp_getattro)(v, name);

}

else if (tp->tp_getattr != NULL) {

const char *name_str = PyUnicode_AsUTF8(name);

if (name_str == NULL) {

*result = NULL;

return -1;

}

*result = (*tp->tp_getattr)(v, (char *)name_str);

}

else {

*result = NULL;

return 0;

}

if (*result != NULL) {

return 1;

}

if (!PyErr_ExceptionMatches(PyExc_AttributeError)) {

return -1;

}

PyErr_Clear();

return 0;

}

int

_PyObject_LookupAttrId(PyObject *v, _Py_Identifier *name, PyObject **result)

{

PyObject *oname = _PyUnicode_FromId(name); /* borrowed */

if (!oname) {

*result = NULL;

return -1;

}

return _PyObject_LookupAttr(v, oname, result);