bpo-42161: Use _PyLong_GetZero() and _PyLong_GetOne() (GH-22995)

Use _PyLong_GetZero() and _PyLong_GetOne()
in Objects/ and Python/ directories.

Author: vstinner

Objects/clinic/complexobject.c.h

@@ -6,6 +6,7 @@
 /* Submitted by Jim Hugunin */
 
 #include "Python.h"
+#include "pycore_long.h"          // _PyLong_GetZero()
 #include "pycore_object.h"        // _PyObject_Init()
 #include "structmember.h"         // PyMemberDef
 
@@ -870,7 +871,7 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
 /*[clinic input]
 @classmethod
 complex.__new__ as complex_new
-    real as r: object(c_default="_PyLong_Zero") = 0
+    real as r: object(c_default="NULL") = 0
     imag as i: object(c_default="NULL") = 0
 
 Create a complex number from a real part and an optional imaginary part.
@@ -880,7 +881,7 @@ This is equivalent to (real + imag*1j) where imag defaults to 0.
 
 static PyObject *
 complex_new_impl(PyTypeObject *type, PyObject *r, PyObject *i)
-/*[clinic end generated code: output=b6c7dd577b537dc1 input=6f6b0bedba29bcb5]*/
+/*[clinic end generated code: output=b6c7dd577b537dc1 input=f4c667f2596d4fd1]*/
 {
     PyObject *tmp;
     PyNumberMethods *nbr, *nbi = NULL;
@@ -889,6 +890,10 @@ complex_new_impl(PyTypeObject *type, PyObject *r, PyObject *i)
     int cr_is_complex = 0;
     int ci_is_complex = 0;
 
+    if (r == NULL) {
+        r = _PyLong_GetZero();
+    }
+
     /* Special-case for a single argument when type(arg) is complex. */
     if (PyComplex_CheckExact(r) && i == NULL &&
         type == &PyComplex_Type) {

Objects/clinic/floatobject.c.h

@@ -1,6 +1,7 @@
 /* enumerate object */
 
 #include "Python.h"
+#include "pycore_long.h"          // _PyLong_GetOne()
 
 #include "clinic/enumobject.c.h"
 
@@ -115,7 +116,7 @@ enum_next_long(enumobject *en, PyObject* next_item)
     }
     next_index = en->en_longindex;
     assert(next_index != NULL);
-    stepped_up = PyNumber_Add(next_index, _PyLong_One);
+    stepped_up = PyNumber_Add(next_index, _PyLong_GetOne());
     if (stepped_up == NULL) {
         Py_DECREF(next_item);
         return NULL;

Objects/complexobject.c

@@ -6,6 +6,7 @@
 #include "Python.h"
 #include "pycore_dtoa.h"          // _Py_dg_dtoa()
 #include "pycore_interp.h"        // _PyInterpreterState.float_state
+#include "pycore_long.h"          // _PyLong_GetOne()
 #include "pycore_object.h"        // _PyObject_Init()
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()
 
@@ -504,7 +505,7 @@ float_richcompare(PyObject *v, PyObject *w, int op)
                 Py_DECREF(vv);
                 vv = temp;
 
-                temp = PyNumber_Or(vv, _PyLong_One);
+                temp = PyNumber_Or(vv, _PyLong_GetOne());
                 if (temp == NULL)
                     goto Error;
                 Py_DECREF(vv);
@@ -1605,18 +1606,26 @@ float_subtype_new(PyTypeObject *type, PyObject *x);
 /*[clinic input]
 @classmethod
 float.__new__ as float_new
-    x: object(c_default="_PyLong_Zero") = 0
+    x: object(c_default="NULL") = 0
     /
 
 Convert a string or number to a floating point number, if possible.
 [clinic start generated code]*/
 
 static PyObject *
 float_new_impl(PyTypeObject *type, PyObject *x)
-/*[clinic end generated code: output=ccf1e8dc460ba6ba input=540ee77c204ff87a]*/
+/*[clinic end generated code: output=ccf1e8dc460ba6ba input=f43661b7de03e9d8]*/
 {
-    if (type != &PyFloat_Type)
+    if (type != &PyFloat_Type) {
+        if (x == NULL) {
+            x = _PyLong_GetZero();
+        }
         return float_subtype_new(type, x); /* Wimp out */
+    }
+
+    if (x == NULL) {
+        return PyFloat_FromDouble(0.0);
+    }
     /* If it's a string, but not a string subclass, use
        PyFloat_FromString. */
     if (PyUnicode_CheckExact(x))
@@ -1662,7 +1671,7 @@ float_vectorcall(PyObject *type, PyObject * const*args,
         return NULL;
     }
 
-    PyObject *x = nargs >= 1 ? args[0] : _PyLong_Zero;
+    PyObject *x = nargs >= 1 ? args[0] : NULL;
     return float_new_impl((PyTypeObject *)type, x);
 }
 

Objects/enumobject.c

@@ -2,6 +2,7 @@
 
 #include "Python.h"
 #include "pycore_abstract.h"      // _PyIndex_Check()
+#include "pycore_long.h"          // _PyLong_GetZero()
 #include "pycore_tuple.h"         // _PyTuple_ITEMS()
 #include "structmember.h"         // PyMemberDef
 
@@ -105,10 +106,10 @@ range_from_array(PyTypeObject *type, PyObject *const *args, Py_ssize_t num_args)
             if (!stop) {
                 return NULL;
             }
-            Py_INCREF(_PyLong_Zero);
-            start = _PyLong_Zero;
-            Py_INCREF(_PyLong_One);
-            step = _PyLong_One;
+            start = _PyLong_GetZero();
+            Py_INCREF(start);
+            step = _PyLong_GetOne();
+            Py_INCREF(step);
             break;
         case 0:
             PyErr_SetString(PyExc_TypeError,
@@ -190,7 +191,10 @@ compute_range_length(PyObject *start, PyObject *stop, PyObject *step)
     PyObject *tmp1 = NULL, *tmp2 = NULL, *result;
                 /* holds sub-expression evaluations */
 
-    cmp_result = PyObject_RichCompareBool(step, _PyLong_Zero, Py_GT);
+    PyObject *zero = _PyLong_GetZero();  // borrowed reference
+    PyObject *one = _PyLong_GetOne();  // borrowed reference
+
+    cmp_result = PyObject_RichCompareBool(step, zero, Py_GT);
     if (cmp_result == -1)
         return NULL;
 
@@ -212,19 +216,21 @@ compute_range_length(PyObject *start, PyObject *stop, PyObject *step)
         Py_DECREF(step);
         if (cmp_result < 0)
             return NULL;
-        return PyLong_FromLong(0);
+        result = zero;
+        Py_INCREF(result);
+        return result;
     }
 
     if ((tmp1 = PyNumber_Subtract(hi, lo)) == NULL)
         goto Fail;
 
-    if ((diff = PyNumber_Subtract(tmp1, _PyLong_One)) == NULL)
+    if ((diff = PyNumber_Subtract(tmp1, one)) == NULL)
         goto Fail;
 
     if ((tmp2 = PyNumber_FloorDivide(diff, step)) == NULL)
         goto Fail;
 
-    if ((result = PyNumber_Add(tmp2, _PyLong_One)) == NULL)
+    if ((result = PyNumber_Add(tmp2, one)) == NULL)
         goto Fail;
 
     Py_DECREF(tmp2);
@@ -254,7 +260,7 @@ compute_item(rangeobject *r, PyObject *i)
     /* PyLong equivalent to:
      *    return r->start + (i * r->step)
      */
-    if (r->step == _PyLong_One) {
+    if (r->step == _PyLong_GetOne()) {
         result = PyNumber_Add(r->start, i);
     }
     else {
@@ -271,6 +277,7 @@ compute_item(rangeobject *r, PyObject *i)
 static PyObject *
 compute_range_item(rangeobject *r, PyObject *arg)
 {
+    PyObject *zero = _PyLong_GetZero();  // borrowed reference
     int cmp_result;
     PyObject *i, *result;
 
@@ -281,7 +288,7 @@ compute_range_item(rangeobject *r, PyObject *arg)
      *     i = arg
      *   }
      */
-    cmp_result = PyObject_RichCompareBool(arg, _PyLong_Zero, Py_LT);
+    cmp_result = PyObject_RichCompareBool(arg, zero, Py_LT);
     if (cmp_result == -1) {
         return NULL;
     }
@@ -300,7 +307,7 @@ compute_range_item(rangeobject *r, PyObject *arg)
      *     <report index out of bounds>
      *   }
      */
-    cmp_result = PyObject_RichCompareBool(i, _PyLong_Zero, Py_LT);
+    cmp_result = PyObject_RichCompareBool(i, zero, Py_LT);
     if (cmp_result == 0) {
         cmp_result = PyObject_RichCompareBool(i, r->length, Py_GE);
     }
@@ -375,14 +382,15 @@ compute_slice(rangeobject *r, PyObject *_slice)
 static int
 range_contains_long(rangeobject *r, PyObject *ob)
 {
+    PyObject *zero = _PyLong_GetZero();  // borrowed reference
     int cmp1, cmp2, cmp3;
     PyObject *tmp1 = NULL;
     PyObject *tmp2 = NULL;
     int result = -1;
 
     /* Check if the value can possibly be in the range. */
 
-    cmp1 = PyObject_RichCompareBool(r->step, _PyLong_Zero, Py_GT);
+    cmp1 = PyObject_RichCompareBool(r->step, zero, Py_GT);
     if (cmp1 == -1)
         goto end;
     if (cmp1 == 1) { /* positive steps: start <= ob < stop */
@@ -409,7 +417,7 @@ range_contains_long(rangeobject *r, PyObject *ob)
     if (tmp2 == NULL)
         goto end;
     /* result = ((int(ob) - start) % step) == 0 */
-    result = PyObject_RichCompareBool(tmp2, _PyLong_Zero, Py_EQ);
+    result = PyObject_RichCompareBool(tmp2, zero, Py_EQ);
   end:
     Py_XDECREF(tmp1);
     Py_XDECREF(tmp2);
@@ -460,7 +468,7 @@ range_equals(rangeobject *r0, rangeobject *r1)
     /* Return False or error to the caller. */
     if (cmp_result != 1)
         return cmp_result;
-    cmp_result = PyObject_RichCompareBool(r0->length, _PyLong_One, Py_EQ);
+    cmp_result = PyObject_RichCompareBool(r0->length, _PyLong_GetOne(), Py_EQ);
     /* Return True or error to the caller. */
     if (cmp_result != 0)
         return cmp_result;
@@ -529,7 +537,7 @@ range_hash(rangeobject *r)
     else {
         Py_INCREF(r->start);
         PyTuple_SET_ITEM(t, 1, r->start);
-        cmp_result = PyObject_RichCompareBool(r->length, _PyLong_One, Py_EQ);
+        cmp_result = PyObject_RichCompareBool(r->length, _PyLong_GetOne(), Py_EQ);
         if (cmp_result == -1)
             goto end;
         if (cmp_result == 1) {
@@ -587,7 +595,7 @@ range_index(rangeobject *r, PyObject *ob)
             return NULL;
         }
 
-        if (r->step == _PyLong_One) {
+        if (r->step == _PyLong_GetOne()) {
             return idx;
         }
 
@@ -974,14 +982,15 @@ longrangeiter_reduce(longrangeiterobject *r, PyObject *Py_UNUSED(ignored))
 static PyObject *
 longrangeiter_setstate(longrangeiterobject *r, PyObject *state)
 {
+    PyObject *zero = _PyLong_GetZero();  // borrowed reference
     int cmp;
 
     /* clip the value */
-    cmp = PyObject_RichCompareBool(state, _PyLong_Zero, Py_LT);
+    cmp = PyObject_RichCompareBool(state, zero, Py_LT);
     if (cmp < 0)
         return NULL;
     if (cmp > 0) {
-        state = _PyLong_Zero;
+        state = zero;
     }
     else {
         cmp = PyObject_RichCompareBool(r->len, state, Py_LT);
@@ -1022,7 +1031,7 @@ longrangeiter_next(longrangeiterobject *r)
     if (PyObject_RichCompareBool(r->index, r->len, Py_LT) != 1)
         return NULL;
 
-    new_index = PyNumber_Add(r->index, _PyLong_One);
+    new_index = PyNumber_Add(r->index, _PyLong_GetOne());
     if (!new_index)
         return NULL;
 
@@ -1119,7 +1128,7 @@ range_iter(PyObject *seq)
     it->start = r->start;
     it->step = r->step;
     it->len = r->length;
-    it->index = _PyLong_Zero;
+    it->index = _PyLong_GetZero();
     Py_INCREF(it->start);
     Py_INCREF(it->step);
     Py_INCREF(it->len);
@@ -1207,7 +1216,7 @@ range_reverse(PyObject *seq, PyObject *Py_UNUSED(ignored))
     it->len = range->length;
     Py_INCREF(it->len);
 
-    diff = PyNumber_Subtract(it->len, _PyLong_One);
+    diff = PyNumber_Subtract(it->len, _PyLong_GetOne());
     if (!diff)
         goto create_failure;
 
@@ -1226,7 +1235,7 @@ range_reverse(PyObject *seq, PyObject *Py_UNUSED(ignored))
     if (!it->step)
         goto create_failure;
 
-    it->index = _PyLong_Zero;
+    it->index = _PyLong_GetZero();
     Py_INCREF(it->index);
     return (PyObject *)it;
 

Objects/floatobject.c

@@ -15,6 +15,7 @@ this type and there is exactly one in existence.
 
 #include "Python.h"
 #include "pycore_abstract.h"      // _PyIndex_Check()
+#include "pycore_long.h"          // _PyLong_GetZero()
 #include "pycore_object.h"        // _PyObject_GC_TRACK()
 #include "structmember.h"         // PyMemberDef
 
@@ -388,7 +389,7 @@ _PySlice_GetLongIndices(PySliceObject *self, PyObject *length,
 
     /* Convert step to an integer; raise for zero step. */
     if (self->step == Py_None) {
-        step = _PyLong_One;
+        step = _PyLong_GetOne();
         Py_INCREF(step);
         step_is_negative = 0;
     }
@@ -417,7 +418,7 @@ _PySlice_GetLongIndices(PySliceObject *self, PyObject *length,
             goto error;
     }
     else {
-        lower = _PyLong_Zero;
+        lower = _PyLong_GetZero();
         Py_INCREF(lower);
         upper = length;
         Py_INCREF(upper);

Objects/rangeobject.c

@@ -1,6 +1,7 @@
 #include "Python.h"
 #include "pycore_initconfig.h"
 #include "pycore_interp.h"        // PyInterpreterState.warnings
+#include "pycore_long.h"          // _PyLong_GetZero()
 #include "pycore_pyerrors.h"
 #include "pycore_pystate.h"       // _PyThreadState_GET()
 #include "frameobject.h"          // PyFrame_GetBack()
@@ -73,7 +74,7 @@ create_filter(PyObject *category, _Py_Identifier *id, const char *modname)
 
     /* This assumes the line number is zero for now. */
     return PyTuple_Pack(5, action_str, Py_None,
-                        category, modname_obj, _PyLong_Zero);
+                        category, modname_obj, _PyLong_GetZero());
 }
 #endif
 
@@ -472,7 +473,7 @@ update_registry(PyObject *registry, PyObject *text, PyObject *category,
     int rc;
 
     if (add_zero)
-        altkey = PyTuple_Pack(3, text, category, _PyLong_Zero);
+        altkey = PyTuple_Pack(3, text, category, _PyLong_GetZero());
     else
         altkey = PyTuple_Pack(2, text, category);