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

#include "Python.h"

#ifdef Py_REF_DEBUG

long _Py_RefTotal;

#endif

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;

extern int tuple_zero_allocs, fast_tuple_allocs;

extern int quick_int_allocs, quick_neg_int_allocs;

extern int null_strings, one_strings;

void

dump_counts(void)

{

PyTypeObject *tp;

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

fprintf(stderr, "%s alloc'd: %d, freed: %d, max in use: %d\n",

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

tp->tp_maxalloc);

fprintf(stderr, "fast tuple allocs: %d, empty: %d\n",

fast_tuple_allocs, tuple_zero_allocs);

fprintf(stderr, "fast int allocs: pos: %d, neg: %d\n",

quick_int_allocs, quick_neg_int_allocs);

fprintf(stderr, "null strings: %d, 1-strings: %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("(siii)", 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_allocs == 0) {

/* first time; insert in linked list */

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

Py_FatalError("XXX inc_count sanity check");

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;

}

#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 %i",

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) */

op->ob_type = tp;

_Py_NewReference(op);

return op;

}

PyVarObject *

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

{

if (op == NULL)

return (PyVarObject *) PyErr_NoMemory();

/* Any changes should be reflected in PyObject_INIT_VAR */

op->ob_size = size;

op->ob_type = 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, int 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);

}

/* for binary compatibility with 2.2 */

#undef _PyObject_Del

void

_PyObject_Del(PyObject *op)

{

PyObject_FREE(op);

}

/* 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) {

fprintf(fp, "<nil>");

}

else {

if (op->ob_refcnt <= 0)

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

op->ob_refcnt, op);

else if (op->ob_type->tp_print == NULL) {

PyObject *s;

if (flags & Py_PRINT_RAW)

s = PyObject_Str(op);

else

s = PyObject_Repr(op);

if (s == NULL)

ret = -1;

else {

ret = internal_print(s, fp, Py_PRINT_RAW,

nesting+1);

}

Py_XDECREF(s);

}

else

ret = (*op->ob_type->tp_print)(op, fp, flags);

}

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. See Misc/gdbinit for some useful gdb hooks */

void _PyObject_Dump(PyObject* op)

{

if (op == NULL)

fprintf(stderr, "NULL\n");

else {

fprintf(stderr, "object : ");

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

fprintf(stderr, "\n"

"type : %s\n"

"refcount: %d\n"

"address : %p\n",

op->ob_type==NULL ? "NULL" : op->ob_type->tp_name,

op->ob_refcnt,

op);

}

}

PyObject *

PyObject_Repr(PyObject *v)

{

if (PyErr_CheckSignals())

return NULL;

#ifdef USE_STACKCHECK

if (PyOS_CheckStack()) {

PyErr_SetString(PyExc_MemoryError, "stack overflow");

return NULL;

}

#endif

if (v == NULL)

return PyString_FromString("<NULL>");

else if (v->ob_type->tp_repr == NULL)

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

v->ob_type->tp_name, v);

else {

PyObject *res;

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

if (res == NULL)

return NULL;

#ifdef Py_USING_UNICODE

if (PyUnicode_Check(res)) {

PyObject* str;

str = PyUnicode_AsUnicodeEscapeString(res);

Py_DECREF(res);

if (str)

res = str;

else

return NULL;

}

#endif

if (!PyString_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 (v == NULL)

return PyString_FromString("<NULL>");

if (PyString_CheckExact(v)) {

Py_INCREF(v);

return v;

}

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

return PyObject_Repr(v);

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

if (res == NULL)

return NULL;

#ifdef Py_USING_UNICODE

if (PyUnicode_Check(res)) {

PyObject* str;

str = PyUnicode_AsEncodedString(res, NULL, NULL);

Py_DECREF(res);

if (str)

res = str;

else

return NULL;

}

#endif

if (!PyString_Check(res)) {

PyErr_Format(PyExc_TypeError,

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

res->ob_type->tp_name);

Py_DECREF(res);

return NULL;

}

return res;

}

#ifdef Py_USING_UNICODE

PyObject *

PyObject_Unicode(PyObject *v)

{

PyObject *res;

if (v == NULL)

res = PyString_FromString("<NULL>");

if (PyUnicode_CheckExact(v)) {

Py_INCREF(v);

return v;

}

if (PyUnicode_Check(v)) {

/* For a Unicode subtype that's not a Unicode object,

return a true Unicode object with the same data. */

return PyUnicode_FromUnicode(PyUnicode_AS_UNICODE(v),

PyUnicode_GET_SIZE(v));

}

if (PyString_Check(v)) {

Py_INCREF(v);

res = v;

}

else {

PyObject *func;

static PyObject *unicodestr;

/* XXX As soon as we have a tp_unicode slot, we should

check this before trying the __unicode__

method. */

if (unicodestr == NULL) {

unicodestr= PyString_InternFromString(

"__unicode__");

if (unicodestr == NULL)

return NULL;

}

func = PyObject_GetAttr(v, unicodestr);

if (func != NULL) {

res = PyEval_CallObject(func, (PyObject *)NULL);

Py_DECREF(func);

}

else {

PyErr_Clear();

if (v->ob_type->tp_str != NULL)

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

else

res = PyObject_Repr(v);

}

}

if (res == NULL)

return NULL;

if (!PyUnicode_Check(res)) {

PyObject *str;

str = PyUnicode_FromEncodedObject(res, NULL, "strict");

Py_DECREF(res);

if (str)

res = str;

else

return NULL;

}

return res;

}

#endif

/* Helper to warn about deprecated tp_compare return values. Return:

-2 for an exception;

-1 if v < w;

0 if v == w;

1 if v > w.

(This function cannot return 2.)

*/

static int

adjust_tp_compare(int c)

{

if (PyErr_Occurred()) {

if (c != -1 && c != -2) {

PyObject *t, *v, *tb;

PyErr_Fetch(&t, &v, &tb);

if (PyErr_Warn(PyExc_RuntimeWarning,

"tp_compare didn't return -1 or -2 "

"for exception") < 0) {

Py_XDECREF(t);

Py_XDECREF(v);

Py_XDECREF(tb);

}

else

PyErr_Restore(t, v, tb);

}

return -2;

}

else if (c < -1 || c > 1) {

if (PyErr_Warn(PyExc_RuntimeWarning,

"tp_compare didn't return -1, 0 or 1") < 0)

return -2;

else

return c < -1 ? -1 : 1;

}

else {

assert(c >= -1 && c <= 1);

return c;

}

}

/* Macro to get the tp_richcompare field of a type if defined */

#define RICHCOMPARE(t) (PyType_HasFeature((t), Py_TPFLAGS_HAVE_RICHCOMPARE) \

? (t)->tp_richcompare : NULL)

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

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

/* Try a genuine rich comparison, returning an object. Return:

NULL for exception;

NotImplemented if this particular rich comparison is not implemented or

undefined;

some object not equal to NotImplemented if it is implemented

(this latter object may not be a Boolean).

*/

static PyObject *

try_rich_compare(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 = RICHCOMPARE(w->ob_type)) != NULL) {

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

if (res != Py_NotImplemented)

return res;

Py_DECREF(res);

}

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

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

if (res != Py_NotImplemented)

return res;

Py_DECREF(res);

}

if ((f = RICHCOMPARE(w->ob_type)) != NULL) {

return (*f)(w, v, swapped_op[op]);

}

res = Py_NotImplemented;

Py_INCREF(res);

return res;

}

/* Try a genuine rich comparison, returning an int. Return:

-1 for exception (including the case where try_rich_compare() returns an

object that's not a Boolean);

0 if the outcome is false;

1 if the outcome is true;

2 if this particular rich comparison is not implemented or undefined.

*/

static int

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

{

PyObject *res;

int ok;

if (RICHCOMPARE(v->ob_type) == NULL && RICHCOMPARE(w->ob_type) == NULL)

return 2; /* Shortcut, avoid INCREF+DECREF */

res = try_rich_compare(v, w, op);

if (res == NULL)

return -1;

if (res == Py_NotImplemented) {

Py_DECREF(res);

return 2;

}

ok = PyObject_IsTrue(res);

Py_DECREF(res);

return ok;

}

/* Try rich comparisons to determine a 3-way comparison. Return:

-2 for an exception;

-1 if v < w;

0 if v == w;

1 if v > w;

2 if this particular rich comparison is not implemented or undefined.

*/

static int

try_rich_to_3way_compare(PyObject *v, PyObject *w)

{

static struct { int op; int outcome; } tries[3] = {

/* Try this operator, and if it is true, use this outcome: */

{Py_EQ, 0},

{Py_LT, -1},

{Py_GT, 1},

};

int i;

if (RICHCOMPARE(v->ob_type) == NULL && RICHCOMPARE(w->ob_type) == NULL)

return 2; /* Shortcut */

for (i = 0; i < 3; i++) {

switch (try_rich_compare_bool(v, w, tries[i].op)) {

case -1:

return -2;

case 1:

return tries[i].outcome;

}

}

return 2;

}

/* Try a 3-way comparison, returning an int. Return:

-2 for an exception;

-1 if v < w;

0 if v == w;

1 if v > w;

2 if this particular 3-way comparison is not implemented or undefined.

*/

static int

try_3way_compare(PyObject *v, PyObject *w)

{

int c;

cmpfunc f;

/* Comparisons involving instances are given to instance_compare,

which has the same return conventions as this function. */

f = v->ob_type->tp_compare;

if (PyInstance_Check(v))

return (*f)(v, w);

if (PyInstance_Check(w))

return (*w->ob_type->tp_compare)(v, w);

/* If both have the same (non-NULL) tp_compare, use it. */

if (f != NULL && f == w->ob_type->tp_compare) {

c = (*f)(v, w);

return adjust_tp_compare(c);

}

/* If either tp_compare is _PyObject_SlotCompare, that's safe. */

if (f == _PyObject_SlotCompare ||

w->ob_type->tp_compare == _PyObject_SlotCompare)

return _PyObject_SlotCompare(v, w);

/* Try coercion; if it fails, give up */

c = PyNumber_CoerceEx(&v, &w);

if (c < 0)

return -2;

if (c > 0)

return 2;

/* Try v's comparison, if defined */

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

c = (*f)(v, w);

Py_DECREF(v);

Py_DECREF(w);

return adjust_tp_compare(c);

}

/* Try w's comparison, if defined */

if ((f = w->ob_type->tp_compare) != NULL) {

c = (*f)(w, v); /* swapped! */

Py_DECREF(v);

Py_DECREF(w);

c = adjust_tp_compare(c);

if (c >= -1)

return -c; /* Swapped! */

else

return c;

}

/* No comparison defined */

Py_DECREF(v);

Py_DECREF(w);

return 2;

}

/* Final fallback 3-way comparison, returning an int. Return:

-2 if an error occurred;

-1 if v < w;

0 if v == w;

1 if v > w.

*/

static int

default_3way_compare(PyObject *v, PyObject *w)

{

int c;

char *vname, *wname;

if (v->ob_type == w->ob_type) {

/* When comparing these pointers, they must be cast to

* integer types (i.e. Py_uintptr_t, our spelling of C9X's

* uintptr_t). ANSI specifies that pointer compares other

* than == and != to non-related structures are undefined.

*/

Py_uintptr_t vv = (Py_uintptr_t)v;

Py_uintptr_t ww = (Py_uintptr_t)w;

return (vv < ww) ? -1 : (vv > ww) ? 1 : 0;

}

#ifdef Py_USING_UNICODE

/* Special case for Unicode */

if (PyUnicode_Check(v) || PyUnicode_Check(w)) {

c = PyUnicode_Compare(v, w);

if (!PyErr_Occurred())

return c;

/* TypeErrors are ignored: if Unicode coercion fails due

to one of the arguments not having the right type, we

continue as defined by the coercion protocol (see

above). Luckily, decoding errors are reported as

ValueErrors and are not masked by this technique. */

if (!PyErr_ExceptionMatches(PyExc_TypeError))

return -2;

PyErr_Clear();

}

#endif

/* None is smaller than anything */

if (v == Py_None)

return -1;

if (w == Py_None)

return 1;

/* different type: compare type names; numbers are smaller */

if (PyNumber_Check(v))

vname = "";

else

vname = v->ob_type->tp_name;

if (PyNumber_Check(w))

wname = "";

else

wname = w->ob_type->tp_name;

c = strcmp(vname, wname);

if (c < 0)

return -1;

if (c > 0)

return 1;

/* Same type name, or (more likely) incomparable numeric types */

return ((Py_uintptr_t)(v->ob_type) < (

Py_uintptr_t)(w->ob_type)) ? -1 : 1;

}

/* Do a 3-way comparison, by hook or by crook. Return:

-2 for an exception (but see below);

-1 if v < w;

0 if v == w;

1 if v > w;

BUT: if the object implements a tp_compare function, it returns

whatever this function returns (whether with an exception or not).

*/

static int

do_cmp(PyObject *v, PyObject *w)

{

int c;

cmpfunc f;

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

&& (f = v->ob_type->tp_compare) != NULL) {

c = (*f)(v, w);

if (PyInstance_Check(v)) {

/* Instance tp_compare has a different signature.

But if it returns undefined we fall through. */

if (c != 2)

return c;

/* Else fall through to try_rich_to_3way_compare() */

}

else

return adjust_tp_compare(c);

}

/* We only get here if one of the following is true:

a) v and w have different types

b) v and w have the same type, which doesn't have tp_compare

c) v and w are instances, and either __cmp__ is not defined or

__cmp__ returns NotImplemented

*/

c = try_rich_to_3way_compare(v, w);

if (c < 2)

return c;

c = try_3way_compare(v, w);

if (c < 2)

return c;

return default_3way_compare(v, w);

}

/* Compare v to w. Return

-1 if v < w or exception (PyErr_Occurred() true in latter case).

0 if v == w.

1 if v > w.

XXX The docs (C API manual) say the return value is undefined in case

XXX of error.

*/

int

PyObject_Compare(PyObject *v, PyObject *w)

{

int result;

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

PyErr_BadInternalCall();

return -1;

}

if (v == w)

return 0;

if (Py_EnterRecursiveCall(" in cmp"))

return -1;

result = do_cmp(v, w);

Py_LeaveRecursiveCall();

return result < 0 ? -1 : result;

}

/* Return (new reference to) Py_True or Py_False. */

static PyObject *

convert_3way_to_object(int op, int c)

{

PyObject *result;

switch (op) {

case Py_LT: c = c < 0; break;

case Py_LE: c = c <= 0; break;

case Py_EQ: c = c == 0; break;

case Py_NE: c = c != 0; break;

case Py_GT: c = c > 0; break;

case Py_GE: c = c >= 0; break;

}

result = c ? Py_True : Py_False;

Py_INCREF(result);

return result;

}

/* We want a rich comparison but don't have one. Try a 3-way cmp instead.

Return

NULL if error

Py_True if v op w

Py_False if not (v op w)

*/

static PyObject *

try_3way_to_rich_compare(PyObject *v, PyObject *w, int op)

{

int c;

c = try_3way_compare(v, w);

if (c >= 2)

c = default_3way_compare(v, w);

if (c <= -2)

return NULL;

return convert_3way_to_object(op, c);

}

/* Do rich comparison on v and w. Return

NULL if error

Else a new reference to an object other than Py_NotImplemented, usually(?):

Py_True if v op w

Py_False if not (v op w)

*/

static PyObject *

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

{

PyObject *res;

res = try_rich_compare(v, w, op);

if (res != Py_NotImplemented)

return res;

Py_DECREF(res);

return try_3way_to_rich_compare(v, w, op);

}

/* Return:

NULL for exception;

some object not equal to NotImplemented if it is implemented

(this latter object may not be a Boolean).

*/

PyObject *

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

{

PyObject *res;

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

if (Py_EnterRecursiveCall(" in cmp"))

return NULL;

/* If the types are equal, and not old-style instances, try to

get out cheap (don't bother with coercions etc.). */

if (v->ob_type == w->ob_type && !PyInstance_Check(v)) {

cmpfunc fcmp;

richcmpfunc frich = RICHCOMPARE(v->ob_type);

/* If the type has richcmp, try it first. try_rich_compare

tries it two-sided, which is not needed since we've a

single type only. */

if (frich != NULL) {

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

if (res != Py_NotImplemented)

goto Done;

Py_DECREF(res);

}

/* No richcmp, or this particular richmp not implemented.

Try 3-way cmp. */

fcmp = v->ob_type->tp_compare;

if (fcmp != NULL) {

int c = (*fcmp)(v, w);

c = adjust_tp_compare(c);

if (c == -2) {

res = NULL;

goto Done;

}

res = convert_3way_to_object(op, c);

goto Done;

}

}

/* Fast path not taken, or couldn't deliver a useful result. */

res = do_richcmp(v, w, op);

Done:

Py_LeaveRecursiveCall();

return res;

}

/* Return -1 if error; 1 if v op w; 0 if not (v op w). */

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 || -intpart > LONG_MAX) {

/* 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)

{

#if SIZEOF_LONG >= SIZEOF_VOID_P

return (long)p;

#else

/* convert to a Python long and hash that */

PyObject* longobj;

long x;

if ((longobj = PyLong_FromVoidPtr(p)) == NULL) {

x = -1;

goto finally;

}

x = PyObject_Hash(longobj);

finally:

Py_XDECREF(longobj);

return x;

#endif

}

long

PyObject_Hash(PyObject *v)

{

PyTypeObject *tp = v->ob_type;

if (tp->tp_hash != NULL)

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

if (tp->tp_compare == NULL && RICHCOMPARE(tp) == NULL) {

return _Py_HashPointer(v); /* Use address as hash value */

}