ref: c2aa8c997aa9f7a6f0bc6cb1ad99cccede44fc72
dir: /sys/src/cmd/python/Modules/testcapi_long.h/
/* Poor-man's template. Macros used:
TESTNAME name of the test (like test_long_api_inner)
TYPENAME the signed type (like long)
F_S_TO_PY convert signed to pylong; TYPENAME -> PyObject*
F_PY_TO_S convert pylong to signed; PyObject* -> TYPENAME
F_U_TO_PY convert unsigned to pylong; unsigned TYPENAME -> PyObject*
F_PY_TO_U convert pylong to unsigned; PyObject* -> unsigned TYPENAME
*/
static PyObject *
TESTNAME(PyObject *error(const char*))
{
const int NBITS = sizeof(TYPENAME) * 8;
unsigned TYPENAME base;
PyObject *pyresult;
int i;
/* Note: This test lets PyObjects leak if an error is raised. Since
an error should never be raised, leaks are impossible <wink>. */
/* Test native -> PyLong -> native roundtrip identity.
* Generate all powers of 2, and test them and their negations,
* plus the numbers +-1 off from them.
*/
base = 1;
for (i = 0;
i < NBITS + 1; /* on last, base overflows to 0 */
++i)
{
int j;
for (j = 0; j < 6; ++j) {
TYPENAME in, out;
unsigned TYPENAME uin, uout;
/* For 0, 1, 2 use base; for 3, 4, 5 use -base */
if(j < 3)
uin = base;
else
uin = (unsigned TYPENAME)(-(TYPENAME)base);
/* For 0 & 3, subtract 1.
* For 1 & 4, leave alone.
* For 2 & 5, add 1.
*/
uin += (unsigned TYPENAME)(TYPENAME)(j % 3 - 1);
pyresult = F_U_TO_PY(uin);
if (pyresult == NULL)
return error(
"unsigned unexpected null result");
uout = F_PY_TO_U(pyresult);
if (uout == (unsigned TYPENAME)-1 && PyErr_Occurred())
return error(
"unsigned unexpected -1 result");
if (uout != uin)
return error(
"unsigned output != input");
UNBIND(pyresult);
in = (TYPENAME)uin;
pyresult = F_S_TO_PY(in);
if (pyresult == NULL)
return error(
"signed unexpected null result");
out = F_PY_TO_S(pyresult);
if (out == (TYPENAME)-1 && PyErr_Occurred())
return error(
"signed unexpected -1 result");
if (out != in)
return error(
"signed output != input");
UNBIND(pyresult);
}
base <<= 1;
}
/* Overflow tests. The loop above ensured that all limit cases that
* should not overflow don't overflow, so all we need to do here is
* provoke one-over-the-limit cases (not exhaustive, but sharp).
*/
{
PyObject *one, *x, *y;
TYPENAME out;
unsigned TYPENAME uout;
one = PyLong_FromLong(1);
if (one == NULL)
return error(
"unexpected NULL from PyLong_FromLong");
/* Unsigned complains about -1? */
x = PyNumber_Negative(one);
if (x == NULL)
return error(
"unexpected NULL from PyNumber_Negative");
uout = F_PY_TO_U(x);
if (uout != (unsigned TYPENAME)-1 || !PyErr_Occurred())
return error(
"PyLong_AsUnsignedXXX(-1) didn't complain");
PyErr_Clear();
UNBIND(x);
/* Unsigned complains about 2**NBITS? */
y = PyLong_FromLong((long)NBITS);
if (y == NULL)
return error(
"unexpected NULL from PyLong_FromLong");
x = PyNumber_Lshift(one, y); /* 1L << NBITS, == 2**NBITS */
UNBIND(y);
if (x == NULL)
return error(
"unexpected NULL from PyNumber_Lshift");
uout = F_PY_TO_U(x);
if (uout != (unsigned TYPENAME)-1 || !PyErr_Occurred())
return error(
"PyLong_AsUnsignedXXX(2**NBITS) didn't "
"complain");
PyErr_Clear();
/* Signed complains about 2**(NBITS-1)?
x still has 2**NBITS. */
y = PyNumber_Rshift(x, one); /* 2**(NBITS-1) */
UNBIND(x);
if (y == NULL)
return error(
"unexpected NULL from PyNumber_Rshift");
out = F_PY_TO_S(y);
if (out != (TYPENAME)-1 || !PyErr_Occurred())
return error(
"PyLong_AsXXX(2**(NBITS-1)) didn't "
"complain");
PyErr_Clear();
/* Signed complains about -2**(NBITS-1)-1?;
y still has 2**(NBITS-1). */
x = PyNumber_Negative(y); /* -(2**(NBITS-1)) */
UNBIND(y);
if (x == NULL)
return error(
"unexpected NULL from PyNumber_Negative");
y = PyNumber_Subtract(x, one); /* -(2**(NBITS-1))-1 */
UNBIND(x);
if (y == NULL)
return error(
"unexpected NULL from PyNumber_Subtract");
out = F_PY_TO_S(y);
if (out != (TYPENAME)-1 || !PyErr_Occurred())
return error(
"PyLong_AsXXX(-2**(NBITS-1)-1) didn't "
"complain");
PyErr_Clear();
UNBIND(y);
Py_XDECREF(x);
Py_XDECREF(y);
Py_DECREF(one);
}
Py_INCREF(Py_None);
return Py_None;
}