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make hashes always the size of pointers; introduce Py_hash_t #9778

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Benjamin Peterson 2010-10-17 20:54:53 +00:00
parent 6fb457526c
commit 8f67d0893f
31 changed files with 137 additions and 131 deletions
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25
Objects/typeobject.c
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@ -4918,13 +4918,12 @@ slot_tp_str(PyObject *self)
}
}
static long
static Py_hash_t
slot_tp_hash(PyObject *self)
{
PyObject *func, *res;
static PyObject *hash_str;
long h;
int overflow;
Py_ssize_t h;
func = lookup_method(self, "__hash__", &hash_str);
@ -4947,20 +4946,20 @@ slot_tp_hash(PyObject *self)
"__hash__ method should return an integer");
return -1;
}
/* Transform the PyLong `res` to a C long `h`. For an existing
hashable Python object x, hash(x) will always lie within the range
of a C long. Therefore our transformation must preserve values
that already lie within this range, to ensure that if x.__hash__()
returns hash(y) then hash(x) == hash(y). */
h = PyLong_AsLongAndOverflow(res, &overflow);
if (overflow)
/* res was not within the range of a C long, so we're free to
/* Transform the PyLong `res` to a Py_hash_t `h`. For an existing
hashable Python object x, hash(x) will always lie within the range of
Py_hash_t. Therefore our transformation must preserve values that
already lie within this range, to ensure that if x.__hash__() returns
hash(y) then hash(x) == hash(y). */
h = PyLong_AsSsize_t(res);
if (h == -1 && PyErr_Occurred()) {
/* res was not within the range of a Py_hash_t, so we're free to
use any sufficiently bit-mixing transformation;
long.__hash__ will do nicely. */
PyErr_Clear();
h = PyLong_Type.tp_hash(res);
}
Py_DECREF(res);
if (h == -1 && !PyErr_Occurred())
h = -2;
return h;
}