/* Generic object operations; and implementation of None (NoObject) */

#include "Python.h"

#include "sliceobject.h" /* For PyEllipsis_Type */

#ifdef __cplusplus

extern "C" {

#endif

#ifdef Py_REF_DEBUG

Py_ssize_t _Py_RefTotal;

Py_ssize_t

_Py_GetRefTotal(void)

{

PyObject *o;

Py_ssize_t total = _Py_RefTotal;

/* ignore the references to the dummy object of the dicts and sets

because they are not reliable and not useful (now that the

hash table code is well-tested) */

o = _PyDict_Dummy();

if (o != NULL)

total -= o->ob_refcnt;

o = _PySet_Dummy();

if (o != NULL)

total -= o->ob_refcnt;

return total;

}

#endif /* Py_REF_DEBUG */

int Py_DivisionWarningFlag;

/* 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.

*/

assert((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 COUNT_ALLOCS

static PyTypeObject *type_list;

/* All types are added to type_list, at least when

they get one object created. That makes them

immortal, which unfortunately contributes to

garbage itself. If unlist_types_without_objects

is set, they will be removed from the type_list

once the last object is deallocated. */

static int unlist_types_without_objects;

extern Py_ssize_t tuple_zero_allocs, fast_tuple_allocs;

extern Py_ssize_t quick_int_allocs, quick_neg_int_allocs;

extern Py_ssize_t null_strings, one_strings;

void

dump_counts(FILE* f)

{

PyTypeObject *tp;

for (tp = type_list; tp; tp = tp->tp_next)

fprintf(f, "%s alloc'd: %" PY_FORMAT_SIZE_T "d, "

"freed: %" PY_FORMAT_SIZE_T "d, "

"max in use: %" PY_FORMAT_SIZE_T "d\n",

tp->tp_name, tp->tp_allocs, tp->tp_frees,

tp->tp_maxalloc);

fprintf(f, "fast tuple allocs: %" PY_FORMAT_SIZE_T "d, "

"empty: %" PY_FORMAT_SIZE_T "d\n",

fast_tuple_allocs, tuple_zero_allocs);

fprintf(f, "fast int allocs: pos: %" PY_FORMAT_SIZE_T "d, "

"neg: %" PY_FORMAT_SIZE_T "d\n",

quick_int_allocs, quick_neg_int_allocs);

fprintf(f, "null strings: %" PY_FORMAT_SIZE_T "d, "

"1-strings: %" PY_FORMAT_SIZE_T "d\n",

null_strings, one_strings);

}

PyObject *

get_counts(void)

{

PyTypeObject *tp;

PyObject *result;

PyObject *v;

result = PyList_New(0);

if (result == NULL)

return NULL;

for (tp = type_list; tp; tp = tp->tp_next) {

v = Py_BuildValue("(snnn)", tp->tp_name, tp->tp_allocs,

tp->tp_frees, tp->tp_maxalloc);

if (v == NULL) {

Py_DECREF(result);

return NULL;

}

if (PyList_Append(result, v) < 0) {

Py_DECREF(v);

Py_DECREF(result);

return NULL;

}

Py_DECREF(v);

}

return result;

}

void

inc_count(PyTypeObject *tp)

{

if (tp->tp_next == NULL && tp->tp_prev == NULL) {

/* first time; insert in linked list */

if (tp->tp_next != NULL) /* sanity check */

Py_FatalError("XXX inc_count sanity check");

if (type_list)

type_list->tp_prev = tp;

tp->tp_next = type_list;

/* Note that as of Python 2.2, heap-allocated type objects

* can go away, but this code requires that they stay alive

* until program exit. That's why we're careful with

* refcounts here. type_list gets a new reference to tp,

* while ownership of the reference type_list used to hold

* (if any) was transferred to tp->tp_next in the line above.

* tp is thus effectively immortal after this.

*/

Py_INCREF(tp);

type_list = tp;

#ifdef Py_TRACE_REFS

/* Also insert in the doubly-linked list of all objects,

* if not already there.

*/

_Py_AddToAllObjects((PyObject *)tp, 0);

#endif

}

tp->tp_allocs++;

if (tp->tp_allocs - tp->tp_frees > tp->tp_maxalloc)

tp->tp_maxalloc = tp->tp_allocs - tp->tp_frees;

}

void dec_count(PyTypeObject *tp)

{

tp->tp_frees++;

if (unlist_types_without_objects &&

tp->tp_allocs == tp->tp_frees) {

/* unlink the type from type_list */

if (tp->tp_prev)

tp->tp_prev->tp_next = tp->tp_next;

else

type_list = tp->tp_next;

if (tp->tp_next)

tp->tp_next->tp_prev = tp->tp_prev;

tp->tp_next = tp->tp_prev = NULL;

Py_DECREF(tp);

}

}

#endif

#ifdef Py_REF_DEBUG

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

void

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

{

char buf[300];

PyOS_snprintf(buf, sizeof(buf),

"%s:%i object at %p has negative ref count "

"%" PY_FORMAT_SIZE_T "d",

fname, lineno, op, op->ob_refcnt);

Py_FatalError(buf);

}

#endif /* Py_REF_DEBUG */

void

Py_IncRef(PyObject *o)

{

Py_XINCREF(o);

}

void

Py_DecRef(PyObject *o)

{

Py_XDECREF(o);

}

PyObject *

PyObject_Init(PyObject *op, PyTypeObject *tp)

{

if (op == NULL)

return PyErr_NoMemory();

/* Any changes should be reflected in PyObject_INIT (objimpl.h) */

Py_TYPE(op) = tp;

_Py_NewReference(op);

return op;

}

PyVarObject *

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

{

if (op == NULL)

return (PyVarObject *) PyErr_NoMemory();

/* Any changes should be reflected in PyObject_INIT_VAR */

op->ob_size = size;

Py_TYPE(op) = tp;

_Py_NewReference((PyObject *)op);

return op;

}

PyObject *

_PyObject_New(PyTypeObject *tp)

{

PyObject *op;

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

if (op == NULL)

return PyErr_NoMemory();

return PyObject_INIT(op, tp);

}

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();

return PyObject_INIT_VAR(op, tp, nitems);

}

/* Implementation of PyObject_Print with recursion checking */

static int

internal_print(PyObject *op, FILE *fp, int flags, int nesting)

{

int ret = 0;

if (nesting > 10) {

PyErr_SetString(PyExc_RuntimeError, "print recursion");

return -1;

}

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 (op->ob_refcnt <= 0)

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

universally available */

Py_BEGIN_ALLOW_THREADS

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

(long)op->ob_refcnt, 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_AsDefaultEncodedString(s, NULL);

if (t == NULL)

ret = 0;

else {

fwrite(PyBytes_AS_STRING(t), 1,

PyBytes_GET_SIZE(t), fp);

}

}

else {

PyErr_Format(PyExc_TypeError,

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

s->ob_type->tp_name);

ret = -1;

}

Py_XDECREF(s);

}

}

if (ret == 0) {

if (ferror(fp)) {

PyErr_SetFromErrno(PyExc_IOError);

clearerr(fp);

ret = -1;

}

}

return ret;

}

int

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

{

return internal_print(op, fp, flags, 0);

}

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

void

_Py_BreakPoint(void)

{

}

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

void

_PyObject_Dump(PyObject* op)

{

if (op == NULL)

fprintf(stderr, "NULL\n");

else {

#ifdef WITH_THREAD

PyGILState_STATE gil;

#endif

fprintf(stderr, "object : ");

#ifdef WITH_THREAD

gil = PyGILState_Ensure();

#endif

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

#ifdef WITH_THREAD

PyGILState_Release(gil);

#endif

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

universally available */

fprintf(stderr, "\n"

"type : %s\n"

"refcount: %ld\n"

"address : %p\n",

Py_TYPE(op)==NULL ? "NULL" : Py_TYPE(op)->tp_name,

(long)op->ob_refcnt,

op);

}

}

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>",

v->ob_type->tp_name, v);

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

if (res != NULL && !PyUnicode_Check(res)) {

PyErr_Format(PyExc_TypeError,

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

res->ob_type->tp_name);

Py_DECREF(res);

return NULL;

}

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)) {

Py_INCREF(v);

return v;

}

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

return PyObject_Repr(v);

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

infinitely. */

if (Py_EnterRecursiveCall(" while getting the str of an object"))

return NULL;

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

Py_LeaveRecursiveCall();

if (res == NULL)

return NULL;

if (!PyUnicode_Check(res)) {

PyErr_Format(PyExc_TypeError,

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

Py_TYPE(res)->tp_name);

Py_DECREF(res);

return NULL;

}

return res;

}

PyObject *

PyObject_ASCII(PyObject *v)

{

PyObject *repr, *ascii, *res;

repr = PyObject_Repr(v);

if (repr == NULL)

return NULL;

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

ascii = PyUnicode_EncodeASCII(

PyUnicode_AS_UNICODE(repr),

PyUnicode_GET_SIZE(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;

static PyObject *bytesstring = NULL;

if (bytesstring == NULL) {

bytesstring = PyUnicode_InternFromString("__bytes__");

if (bytesstring == NULL)

return NULL;

}

if (v == NULL)

return PyBytes_FromString("<NULL>");

if (PyBytes_CheckExact(v)) {

Py_INCREF(v);

return v;

}

/* Doesn't create a reference */

func = _PyType_Lookup(Py_TYPE(v), bytesstring);

if (func != NULL) {

result = PyObject_CallFunctionObjArgs(func, v, NULL);

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;

}

PyErr_Clear();

return PyBytes_FromObject(v);

}

/* 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_reserved, 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 char *opstrings[] = {"<", "<=", "==", "!=", ">", ">="};

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

operator is not supported. */

static PyObject *

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

{

richcmpfunc f;

PyObject *res;

if (v->ob_type != w->ob_type &&

PyType_IsSubtype(w->ob_type, v->ob_type) &&

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

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

if (res != Py_NotImplemented)

return res;

Py_DECREF(res);

}

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

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

if (res != Py_NotImplemented)

return res;

Py_DECREF(res);

}

if ((f = w->ob_type->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:

/* XXX Special-case None so it doesn't show as NoneType() */

PyErr_Format(PyExc_TypeError,

"unorderable types: %.100s() %s %.100s()",

v->ob_type->tp_name,

opstrings[op],

w->ob_type->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)

{

PyObject *res;

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

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

if (!PyErr_Occurred())

PyErr_BadInternalCall();

return NULL;

}

if (Py_EnterRecursiveCall(" in cmp"))

return NULL;

res = do_richcompare(v, w, op);

Py_LeaveRecursiveCall();

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;

}

/* Set of hash utility functions to help maintaining the invariant that

if a==b then hash(a)==hash(b)

All the utility functions (_Py_Hash*()) return "-1" to signify an error.

*/

long

_Py_HashDouble(double v)

{

double intpart, fractpart;

int expo;

long hipart;

long x; /* the final hash value */

/* This is designed so that Python numbers of different types

* that compare equal hash to the same value; otherwise comparisons

* of mapping keys will turn out weird.

*/

fractpart = modf(v, &intpart);

if (fractpart == 0.0) {

/* This must return the same hash as an equal int or long. */

if (intpart > LONG_MAX/2 || -intpart > LONG_MAX/2) {

/* Convert to long and use its hash. */

PyObject *plong; /* converted to Python long */

if (Py_IS_INFINITY(intpart))

/* can't convert to long int -- arbitrary */

v = v < 0 ? -271828.0 : 314159.0;

plong = PyLong_FromDouble(v);

if (plong == NULL)

return -1;

x = PyObject_Hash(plong);

Py_DECREF(plong);

return x;

}

/* Fits in a C long == a Python int, so is its own hash. */

x = (long)intpart;

if (x == -1)

x = -2;

return x;

}

/* The fractional part is non-zero, so we don't have to worry about

* making this match the hash of some other type.

* Use frexp to get at the bits in the double.

* Since the VAX D double format has 56 mantissa bits, which is the

* most of any double format in use, each of these parts may have as

* many as (but no more than) 56 significant bits.

* So, assuming sizeof(long) >= 4, each part can be broken into two

* longs; frexp and multiplication are used to do that.

* Also, since the Cray double format has 15 exponent bits, which is

* the most of any double format in use, shifting the exponent field

* left by 15 won't overflow a long (again assuming sizeof(long) >= 4).

*/

v = frexp(v, &expo);

v *= 2147483648.0; /* 2**31 */

hipart = (long)v; /* take the top 32 bits */

v = (v - (double)hipart) * 2147483648.0; /* get the next 32 bits */

x = hipart + (long)v + (expo << 15);

if (x == -1)

x = -2;

return x;

}

long

_Py_HashPointer(void *p)

{

long x;

size_t y = (size_t)p;

/* bottom 3 or 4 bits are likely to be 0; rotate y by 4 to avoid

excessive hash collisions for dicts and sets */

y = (y >> 4) | (y << (8 * SIZEOF_VOID_P - 4));

x = (long)y;

if (x == -1)

x = -2;

return x;

}

long

PyObject_HashNotImplemented(PyObject *v)

{

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

Py_TYPE(v)->tp_name);

return -1;

}

long

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_InternFromString(name);

if (w == NULL)

return NULL;

res = PyObject_GetAttr(v, w);

Py_XDECREF(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;

}

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'",

name->ob_type->tp_name);

return NULL;

}

if (tp->tp_getattro != NULL)

return (*tp->tp_getattro)(v, name);

if (tp->tp_getattr != NULL)

return (*tp->tp_getattr)(v, _PyUnicode_AsString(name));

PyErr_Format(PyExc_AttributeError,

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

tp->tp_name, name);

return NULL;

}

int

PyObject_HasAttr(PyObject *v, PyObject *name)

{

PyObject *res = PyObject_GetAttr(v, name);

if (res != NULL) {

Py_DECREF(res);

return 1;

}

PyErr_Clear();

return 0;

}

int

PyObject_SetAttr(PyObject *v, PyObject *name, PyObject *value)

{

PyTypeObject *tp = Py_TYPE(v);

int err;

if (!PyUnicode_Check(name)) {

PyErr_Format(PyExc_TypeError,

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

name->ob_type->tp_name);

return -1;

}

Py_INCREF(name);

PyUnicode_InternInPlace(&name);

if (tp->tp_setattro != NULL) {

err = (*tp->tp_setattro)(v, name, value);

Py_DECREF(name);

return err;

}

if (tp->tp_setattr != NULL) {

err = (*tp->tp_setattr)(v, _PyUnicode_AsString(name), value);

Py_DECREF(name);

return err;

}

Py_DECREF(name);

assert(name->ob_refcnt >= 1);

if (tp->tp_getattr == NULL && tp->tp_getattro == NULL)

PyErr_Format(PyExc_TypeError,

"'%.100s' object has no attributes "

"(%s .%U)",

tp->tp_name,

value==NULL ? "del" : "assign to",

name);

else

PyErr_Format(PyExc_TypeError,

"'%.100s' object has only read-only attributes "

"(%s .%U)",

tp->tp_name,

value==NULL ? "del" : "assign to",

name);

return -1;

}

/* Helper to get a pointer to an object's __dict__ slot, if any */

PyObject **

_PyObject_GetDictPtr(PyObject *obj)

{

Py_ssize_t dictoffset;

PyTypeObject *tp = Py_TYPE(obj);

dictoffset = tp->tp_dictoffset;

if (dictoffset == 0)

return NULL;

if (dictoffset < 0) {

Py_ssize_t tsize;

size_t size;

tsize = ((PyVarObject *)obj)->ob_size;

if (tsize < 0)

tsize = -tsize;

size = _PyObject_VAR_SIZE(tp, tsize);

dictoffset += (long)size;

assert(dictoffset > 0);

assert(dictoffset % SIZEOF_VOID_P == 0);

}

return (PyObject **) ((char *)obj + dictoffset);

}

PyObject *

PyObject_SelfIter(PyObject *obj)

{

Py_INCREF(obj);

return obj;

}

/* Helper used when the __next__ method is removed from a type:

tp_iternext is never NULL and can be safely called without checking

on every iteration.

*/

PyObject *

_PyObject_NextNotImplemented(PyObject *self)

{

PyErr_Format(PyExc_TypeError,

"'%.200s' object is not iterable",

Py_TYPE(self)->tp_name);

return NULL;

}

/* Generic GetAttr functions - put these in your tp_[gs]etattro slot */

PyObject *

PyObject_GenericGetAttr(PyObject *obj, PyObject *name)

{

PyTypeObject *tp = Py_TYPE(obj);

PyObject *descr = NULL;

PyObject *res = NULL;

descrgetfunc f;

Py_ssize_t dictoffset;

PyObject **dictptr;

if (!PyUnicode_Check(name)){

PyErr_Format(PyExc_TypeError,

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

name->ob_type->tp_name);

return NULL;

}

else

Py_INCREF(name);

if (tp->tp_dict == NULL) {

if (PyType_Ready(tp) < 0)

goto done;

}

#if 0 /* XXX this is not quite _PyType_Lookup anymore */

/* Inline _PyType_Lookup */

{

Py_ssize_t i, n;

PyObject *mro, *base, *dict;

/* Look in tp_dict of types in MRO */

mro = tp->tp_mro;

assert(mro != NULL);

assert(PyTuple_Check(mro));

n = PyTuple_GET_SIZE(mro);

for (i = 0; i < n; i++) {

base = PyTuple_GET_ITEM(mro, i);

assert(PyType_Check(base));

dict = ((PyTypeObject *)base)->tp_dict;

assert(dict && PyDict_Check(dict));

descr = PyDict_GetItem(dict, name);

if (descr != NULL)

break;

}

}

#else

descr = _PyType_Lookup(tp, name);

#endif

Py_XINCREF(descr);

f = NULL;

if (descr != NULL) {

f = descr->ob_type->tp_descr_get;

if (f != NULL && PyDescr_IsData(descr)) {

res = f(descr, obj, (PyObject *)obj->ob_type);

Py_DECREF(descr);

goto done;

}

}

/* Inline _PyObject_GetDictPtr */

dictoffset = tp->tp_dictoffset;

if (dictoffset != 0) {

PyObject *dict;

if (dictoffset < 0) {

Py_ssize_t tsize;

size_t size;

tsize = ((PyVarObject *)obj)->ob_size;

if (tsize < 0)

tsize = -tsize;

size = _PyObject_VAR_SIZE(tp, tsize);

dictoffset += (long)size;

assert(dictoffset > 0);

assert(dictoffset % SIZEOF_VOID_P == 0);

}

dictptr = (PyObject **) ((char *)obj + dictoffset);

dict = *dictptr;

if (dict != NULL) {

Py_INCREF(dict);

res = PyDict_GetItem(dict, name);