bpo-43753: Add Py_Is() and Py_IsNone() functions (GH-25227)

Add the Py_Is(x, y) function to test if the 'x' object is the 'y'
object, the same as "x is y" in Python. Add also the Py_IsNone(),
Py_IsTrue(), Py_IsFalse() functions to test if an object is,
respectively, the None singleton, the True singleton or the False
singleton.
This commit is contained in:
Victor Stinner 2021-04-11 00:17:39 +02:00 committed by GitHub
parent 6e468cb16b
commit 09bbebea16
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
9 changed files with 198 additions and 38 deletions

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@ -62,6 +62,37 @@ the definition of all other Python objects.
See documentation of :c:type:`PyVarObject` above.
.. c:function:: int Py_Is(const PyObject *x, const PyObject *y)
Test if the *x* object is the *y* object, the same as ``x is y`` in Python.
.. versionadded:: 3.10
.. c:function:: int Py_IsNone(const PyObject *x)
Test if an object is the ``None`` singleton,
the same as ``x is None`` in Python.
.. versionadded:: 3.10
.. c:function:: int Py_IsTrue(const PyObject *x)
Test if an object is the ``True`` singleton,
the same as ``x is True`` in Python.
.. versionadded:: 3.10
.. c:function:: int Py_IsFalse(const PyObject *x)
Test if an object is the ``False`` singleton,
the same as ``x is False`` in Python.
.. versionadded:: 3.10
.. c:function:: PyTypeObject* Py_TYPE(const PyObject *o)
Get the type of the Python object *o*.

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@ -767,7 +767,11 @@ Py_HasFileSystemDefaultEncoding
Py_IncRef
Py_Initialize
Py_InitializeEx
Py_Is
Py_IsFalse
Py_IsInitialized
Py_IsNone
Py_IsTrue
Py_LeaveRecursiveCall
Py_Main
Py_MakePendingCalls

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@ -1385,6 +1385,13 @@ New Features
build (``Py_TRACE_REFS`` macro).
(Contributed by Victor Stinner in :issue:`43688`.)
* Add the :c:func:`Py_Is(x, y) <Py_Is>` function to test if the *x* object is
the *y* object, the same as ``x is y`` in Python. Add also the
:c:func:`Py_IsNone`, :c:func:`Py_IsTrue`, :c:func:`Py_IsFalse` functions to
test if an object is, respectively, the ``None`` singleton, the ``True``
singleton or the ``False`` singleton.
(Contributed by Victor Stinner in :issue:`43753`.)
Porting to Python 3.10
----------------------

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@ -21,6 +21,14 @@ PyAPI_DATA(struct _longobject) _Py_FalseStruct, _Py_TrueStruct;
#define Py_False ((PyObject *) &_Py_FalseStruct)
#define Py_True ((PyObject *) &_Py_TrueStruct)
// Test if an object is the True singleton, the same as "x is True" in Python.
PyAPI_FUNC(int) Py_IsTrue(PyObject *x);
#define Py_IsTrue(x) Py_Is((x), Py_True)
// Test if an object is the False singleton, the same as "x is False" in Python.
PyAPI_FUNC(int) Py_IsFalse(PyObject *x);
#define Py_IsFalse(x) Py_Is((x), Py_False)
/* Macros for returning Py_True or Py_False, respectively */
#define Py_RETURN_TRUE return Py_NewRef(Py_True)
#define Py_RETURN_FALSE return Py_NewRef(Py_False)

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@ -122,6 +122,11 @@ typedef struct {
#define _PyVarObject_CAST_CONST(op) ((const PyVarObject*)(op))
// Test if the 'x' object is the 'y' object, the same as "x is y" in Python.
PyAPI_FUNC(int) Py_Is(PyObject *x, PyObject *y);
#define Py_Is(x, y) ((x) == (y))
static inline Py_ssize_t _Py_REFCNT(const PyObject *ob) {
return ob->ob_refcnt;
}
@ -586,6 +591,10 @@ Don't forget to apply Py_INCREF() when returning this value!!!
PyAPI_DATA(PyObject) _Py_NoneStruct; /* Don't use this directly */
#define Py_None (&_Py_NoneStruct)
// Test if an object is the None singleton, the same as "x is None" in Python.
PyAPI_FUNC(int) Py_IsNone(PyObject *x);
#define Py_IsNone(x) Py_Is((x), Py_None)
/* Macro for returning Py_None from a function */
#define Py_RETURN_NONE return Py_NewRef(Py_None)

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@ -0,0 +1,6 @@
Add the :c:func:`Py_Is(x, y) <Py_Is>` function to test if the *x* object is the
*y* object, the same as ``x is y`` in Python. Add also the :c:func:`Py_IsNone`,
:c:func:`Py_IsTrue`, :c:func:`Py_IsFalse` functions to test if an object is,
respectively, the ``None`` singleton, the ``True`` singleton or the ``False``
singleton.
Patch by Victor Stinner.

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@ -5401,32 +5401,98 @@ test_set_type_size(PyObject *self, PyObject *Py_UNUSED(ignored))
}
// Test Py_NewRef() and Py_XNewRef() functions
#define TEST_REFCOUNT() \
do { \
PyObject *obj = PyList_New(0); \
if (obj == NULL) { \
return NULL; \
} \
assert(Py_REFCNT(obj) == 1); \
\
/* test Py_NewRef() */ \
PyObject *ref = Py_NewRef(obj); \
assert(ref == obj); \
assert(Py_REFCNT(obj) == 2); \
Py_DECREF(ref); \
\
/* test Py_XNewRef() */ \
PyObject *xref = Py_XNewRef(obj); \
assert(xref == obj); \
assert(Py_REFCNT(obj) == 2); \
Py_DECREF(xref); \
\
assert(Py_XNewRef(NULL) == NULL); \
\
Py_DECREF(obj); \
Py_RETURN_NONE; \
} while (0) \
// Test Py_NewRef() and Py_XNewRef() macros
static PyObject*
test_refcount(PyObject *self, PyObject *Py_UNUSED(ignored))
test_refcount_macros(PyObject *self, PyObject *Py_UNUSED(ignored))
{
PyObject *obj = PyList_New(0);
if (obj == NULL) {
return NULL;
}
assert(Py_REFCNT(obj) == 1);
TEST_REFCOUNT();
}
// Test Py_NewRef()
PyObject *ref = Py_NewRef(obj);
assert(ref == obj);
assert(Py_REFCNT(obj) == 2);
Py_DECREF(ref);
#undef Py_NewRef
#undef Py_XNewRef
// Test Py_XNewRef()
PyObject *xref = Py_XNewRef(obj);
assert(xref == obj);
assert(Py_REFCNT(obj) == 2);
Py_DECREF(xref);
// Test Py_NewRef() and Py_XNewRef() functions, after undefining macros.
static PyObject*
test_refcount_funcs(PyObject *self, PyObject *Py_UNUSED(ignored))
{
TEST_REFCOUNT();
}
assert(Py_XNewRef(NULL) == NULL);
Py_DECREF(obj);
Py_RETURN_NONE;
// Test Py_Is() function
#define TEST_PY_IS() \
do { \
PyObject *o_none = Py_None; \
PyObject *o_true = Py_True; \
PyObject *o_false = Py_False; \
PyObject *obj = PyList_New(0); \
if (obj == NULL) { \
return NULL; \
} \
\
/* test Py_Is() */ \
assert(Py_Is(obj, obj)); \
assert(!Py_Is(obj, o_none)); \
\
/* test Py_None */ \
assert(Py_Is(o_none, o_none)); \
assert(!Py_Is(obj, o_none)); \
\
/* test Py_True */ \
assert(Py_Is(o_true, o_true)); \
assert(!Py_Is(o_false, o_true)); \
assert(!Py_Is(obj, o_true)); \
\
/* test Py_False */ \
assert(Py_Is(o_false, o_false)); \
assert(!Py_Is(o_true, o_false)); \
assert(!Py_Is(obj, o_false)); \
\
Py_DECREF(obj); \
Py_RETURN_NONE; \
} while (0)
// Test Py_Is() macro
static PyObject*
test_py_is_macros(PyObject *self, PyObject *Py_UNUSED(ignored))
{
TEST_PY_IS();
}
#undef Py_Is
// Test Py_Is() function, after undefining its macro.
static PyObject*
test_py_is_funcs(PyObject *self, PyObject *Py_UNUSED(ignored))
{
TEST_PY_IS();
}
@ -5716,7 +5782,10 @@ static PyMethodDef TestMethods[] = {
{"pynumber_tobase", pynumber_tobase, METH_VARARGS},
{"without_gc", without_gc, METH_O},
{"test_set_type_size", test_set_type_size, METH_NOARGS},
{"test_refcount", test_refcount, METH_NOARGS},
{"test_refcount_macros", test_refcount_macros, METH_NOARGS},
{"test_refcount_funcs", test_refcount_funcs, METH_NOARGS},
{"test_py_is_macros", test_py_is_macros, METH_NOARGS},
{"test_py_is_funcs", test_py_is_funcs, METH_NOARGS},
{"fatal_error", test_fatal_error, METH_VARARGS,
PyDoc_STR("fatal_error(message, release_gil=False): call Py_FatalError(message)")},
{NULL, NULL} /* sentinel */

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@ -2279,6 +2279,33 @@ Py_XNewRef(PyObject *obj)
return _Py_XNewRef(obj);
}
#undef Py_Is
#undef Py_IsNone
#undef Py_IsTrue
#undef Py_IsFalse
// Export Py_Is(), Py_IsNone(), Py_IsTrue(), Py_IsFalse() as regular functions
// for the stable ABI.
int Py_Is(PyObject *x, PyObject *y)
{
return (x == y);
}
int Py_IsNone(PyObject *x)
{
return Py_Is(x, Py_None);
}
int Py_IsTrue(PyObject *x)
{
return Py_Is(x, Py_True);
}
int Py_IsFalse(PyObject *x)
{
return Py_Is(x, Py_False);
}
#ifdef __cplusplus
}
#endif

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@ -1,4 +1,3 @@
/* Execute compiled code */
/* XXX TO DO:
@ -2570,7 +2569,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
gen_status = PyIter_Send(receiver, v, &retval);
} else {
_Py_IDENTIFIER(send);
if (v == Py_None && PyIter_Check(receiver)) {
if (Py_IsNone(v) && PyIter_Check(receiver)) {
retval = Py_TYPE(receiver)->tp_iternext(receiver);
}
else {
@ -2634,7 +2633,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
case TARGET(GEN_START): {
PyObject *none = POP();
Py_DECREF(none);
if (none != Py_None) {
if (!Py_IsNone(none)) {
if (oparg > 2) {
_PyErr_SetString(tstate, PyExc_SystemError,
"Illegal kind for GEN_START");
@ -3615,7 +3614,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
case TARGET(IS_OP): {
PyObject *right = POP();
PyObject *left = TOP();
int res = (left == right)^oparg;
int res = Py_Is(left, right) ^ oparg;
PyObject *b = res ? Py_True : Py_False;
Py_INCREF(b);
SET_TOP(b);
@ -3744,11 +3743,11 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
PREDICTED(POP_JUMP_IF_FALSE);
PyObject *cond = POP();
int err;
if (cond == Py_True) {
if (Py_IsTrue(cond)) {
Py_DECREF(cond);
DISPATCH();
}
if (cond == Py_False) {
if (Py_IsFalse(cond)) {
Py_DECREF(cond);
JUMPTO(oparg);
DISPATCH();
@ -3768,11 +3767,11 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
PREDICTED(POP_JUMP_IF_TRUE);
PyObject *cond = POP();
int err;
if (cond == Py_False) {
if (Py_IsFalse(cond)) {
Py_DECREF(cond);
DISPATCH();
}
if (cond == Py_True) {
if (Py_IsTrue(cond)) {
Py_DECREF(cond);
JUMPTO(oparg);
DISPATCH();
@ -3792,12 +3791,12 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
case TARGET(JUMP_IF_FALSE_OR_POP): {
PyObject *cond = TOP();
int err;
if (cond == Py_True) {
if (Py_IsTrue(cond)) {
STACK_SHRINK(1);
Py_DECREF(cond);
DISPATCH();
}
if (cond == Py_False) {
if (Py_IsFalse(cond)) {
JUMPTO(oparg);
DISPATCH();
}
@ -3816,12 +3815,12 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
case TARGET(JUMP_IF_TRUE_OR_POP): {
PyObject *cond = TOP();
int err;
if (cond == Py_False) {
if (Py_IsFalse(cond)) {
STACK_SHRINK(1);
Py_DECREF(cond);
DISPATCH();
}
if (cond == Py_True) {
if (Py_IsTrue(cond)) {
JUMPTO(oparg);
DISPATCH();
}
@ -3966,7 +3965,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
goto error;
}
PUSH(values_or_none);
if (values_or_none == Py_None) {
if (Py_IsNone(values_or_none)) {
Py_INCREF(Py_False);
PUSH(Py_False);
DISPATCH();
@ -4157,7 +4156,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
exc = TOP();
val = SECOND();
tb = THIRD();
assert(exc != Py_None);
assert(!Py_IsNone(exc));
assert(!PyLong_Check(exc));
exit_func = PEEK(7);
PyObject *stack[4] = {NULL, exc, val, tb};
@ -5235,7 +5234,7 @@ do_raise(PyThreadState *tstate, PyObject *exc, PyObject *cause)
type = exc_info->exc_type;
value = exc_info->exc_value;
tb = exc_info->exc_traceback;
if (type == Py_None || type == NULL) {
if (Py_IsNone(type) || type == NULL) {
_PyErr_SetString(tstate, PyExc_RuntimeError,
"No active exception to reraise");
return 0;
@ -5293,7 +5292,7 @@ do_raise(PyThreadState *tstate, PyObject *exc, PyObject *cause)
else if (PyExceptionInstance_Check(cause)) {
fixed_cause = cause;
}
else if (cause == Py_None) {
else if (Py_IsNone(cause)) {
Py_DECREF(cause);
fixed_cause = NULL;
}
@ -5987,7 +5986,7 @@ int
_PyEval_SliceIndex(PyObject *v, Py_ssize_t *pi)
{
PyThreadState *tstate = _PyThreadState_GET();
if (v != Py_None) {
if (!Py_IsNone(v)) {
Py_ssize_t x;
if (_PyIndex_Check(v)) {
x = PyNumber_AsSsize_t(v, NULL);