bpo-29878: Add global instances of int for 0 and 1. (#852)

Author: serhiy-storchaka

Include/longobject.h

@@ -209,6 +209,11 @@ PyAPI_FUNC(long) PyOS_strtol(const char *, char **, int);
 PyAPI_FUNC(PyObject *) _PyLong_GCD(PyObject *, PyObject *);
 #endif /* !Py_LIMITED_API */
 
+#ifndef Py_LIMITED_API
+PyAPI_DATA(PyObject *) _PyLong_Zero;
+PyAPI_DATA(PyObject *) _PyLong_One;
+#endif
+
 #ifdef __cplusplus
 }
 #endif

Modules/_collectionsmodule.c

@@ -2267,8 +2267,6 @@ _count_elements(PyObject *self, PyObject *args)
     PyObject *it, *iterable, *mapping, *oldval;
     PyObject *newval = NULL;
     PyObject *key = NULL;
-    PyObject *zero = NULL;
-    PyObject *one = NULL;
     PyObject *bound_get = NULL;
     PyObject *mapping_get;
     PyObject *dict_get;
@@ -2282,10 +2280,6 @@ _count_elements(PyObject *self, PyObject *args)
     if (it == NULL)
         return NULL;
 
-    one = PyLong_FromLong(1);
-    if (one == NULL)
-        goto done;
-
     /* Only take the fast path when get() and __setitem__()
      * have not been overridden.
      */
@@ -2325,10 +2319,10 @@ _count_elements(PyObject *self, PyObject *args)
             if (oldval == NULL) {
                 if (PyErr_Occurred())
                     goto done;
-                if (_PyDict_SetItem_KnownHash(mapping, key, one, hash) < 0)
+                if (_PyDict_SetItem_KnownHash(mapping, key, _PyLong_One, hash) < 0)
                     goto done;
             } else {
-                newval = PyNumber_Add(oldval, one);
+                newval = PyNumber_Add(oldval, _PyLong_One);
                 if (newval == NULL)
                     goto done;
                 if (_PyDict_SetItem_KnownHash(mapping, key, newval, hash) < 0)
@@ -2342,18 +2336,14 @@ _count_elements(PyObject *self, PyObject *args)
         if (bound_get == NULL)
             goto done;
 
-        zero = PyLong_FromLong(0);
-        if (zero == NULL)
-            goto done;
-
         while (1) {
             key = PyIter_Next(it);
             if (key == NULL)
                 break;
-            oldval = PyObject_CallFunctionObjArgs(bound_get, key, zero, NULL);
+            oldval = PyObject_CallFunctionObjArgs(bound_get, key, _PyLong_Zero, NULL);
             if (oldval == NULL)
                 break;
-            newval = PyNumber_Add(oldval, one);
+            newval = PyNumber_Add(oldval, _PyLong_One);
             Py_DECREF(oldval);
             if (newval == NULL)
                 break;
@@ -2369,8 +2359,6 @@ _count_elements(PyObject *self, PyObject *args)
     Py_XDECREF(key);
     Py_XDECREF(newval);
     Py_XDECREF(bound_get);
-    Py_XDECREF(zero);
-    Py_XDECREF(one);
     if (PyErr_Occurred())
         return NULL;
     Py_RETURN_NONE;

Modules/_ctypes/_ctypes.c

@@ -3606,12 +3606,9 @@ _build_callargs(PyCFuncPtrObject *self, PyObject *argtypes,
         case PARAMFLAG_FIN | PARAMFLAG_FLCID:
             /* ['in', 'lcid'] parameter.  Always taken from defval,
              if given, else the integer 0. */
-            if (defval == NULL) {
-                defval = PyLong_FromLong(0);
-                if (defval == NULL)
-                    goto error;
-            } else
-                Py_INCREF(defval);
+            if (defval == NULL)
+                defval = _PyLong_Zero;
+            Py_INCREF(defval);
             PyTuple_SET_ITEM(callargs, i, defval);
             break;
         case (PARAMFLAG_FIN | PARAMFLAG_FOUT):

Modules/_datetimemodule.c

@@ -1481,7 +1481,6 @@ cmperror(PyObject *a, PyObject *b)
  */
 
 /* Conversion factors. */
-static PyObject *one = NULL;      /* 1 */
 static PyObject *us_per_ms = NULL;      /* 1000 */
 static PyObject *us_per_second = NULL;  /* 1000000 */
 static PyObject *us_per_minute = NULL;  /* 1e6 * 60 as Python int */
@@ -2201,7 +2200,7 @@ delta_new(PyTypeObject *type, PyObject *args, PyObject *kw)
         goto Done
 
     if (us) {
-        y = accum("microseconds", x, us, one, &leftover_us);
+        y = accum("microseconds", x, us, _PyLong_One, &leftover_us);
         CLEANUP;
     }
     if (ms) {
@@ -2241,7 +2240,7 @@ delta_new(PyTypeObject *type, PyObject *args, PyObject *kw)
              * is odd. Note that x is odd when it's last bit is 1. The
              * code below uses bitwise and operation to check the last
              * bit. */
-            temp = PyNumber_And(x, one);  /* temp <- x & 1 */
+            temp = PyNumber_And(x, _PyLong_One);  /* temp <- x & 1 */
             if (temp == NULL) {
                 Py_DECREF(x);
                 goto Done;
@@ -5839,12 +5838,11 @@ PyInit__datetime(void)
     Py_BUILD_ASSERT(DI100Y == 25 * DI4Y - 1);
     assert(DI100Y == days_before_year(100+1));
 
-    one = PyLong_FromLong(1);
     us_per_ms = PyLong_FromLong(1000);
     us_per_second = PyLong_FromLong(1000000);
     us_per_minute = PyLong_FromLong(60000000);
     seconds_per_day = PyLong_FromLong(24 * 3600);
-    if (one == NULL || us_per_ms == NULL || us_per_second == NULL ||
+    if (us_per_ms == NULL || us_per_second == NULL ||
         us_per_minute == NULL || seconds_per_day == NULL)
         return NULL;
 

Modules/_functoolsmodule.c

@@ -529,15 +529,8 @@ keyobject_richcompare(PyObject *ko, PyObject *other, int op)
     PyObject *y;
     PyObject *compare;
     PyObject *answer;
-    static PyObject *zero;
     PyObject* stack[2];
 
-    if (zero == NULL) {
-        zero = PyLong_FromLong(0);
-        if (!zero)
-            return NULL;
-    }
-
     if (Py_TYPE(other) != &keyobject_type){
         PyErr_Format(PyExc_TypeError, "other argument must be K instance");
         return NULL;
@@ -561,7 +554,7 @@ keyobject_richcompare(PyObject *ko, PyObject *other, int op)
         return NULL;
     }
 
-    answer = PyObject_RichCompare(res, zero, op);
+    answer = PyObject_RichCompare(res, _PyLong_Zero, op);
     Py_DECREF(res);
     return answer;
 }

Modules/_io/_iomodule.c

@@ -53,7 +53,6 @@ PyObject *_PyIO_str_write;
 
 PyObject *_PyIO_empty_str;
 PyObject *_PyIO_empty_bytes;
-PyObject *_PyIO_zero;
 
 PyDoc_STRVAR(module_doc,
 "The io module provides the Python interfaces to stream handling. The\n"
@@ -790,9 +789,6 @@ PyInit__io(void)
     if (!_PyIO_empty_bytes &&
         !(_PyIO_empty_bytes = PyBytes_FromStringAndSize(NULL, 0)))
         goto fail;
-    if (!_PyIO_zero &&
-        !(_PyIO_zero = PyLong_FromLong(0L)))
-        goto fail;
 
     state->initialized = 1;
 

Modules/_io/_iomodule.h

@@ -183,6 +183,5 @@ extern PyObject *_PyIO_str_write;
 
 extern PyObject *_PyIO_empty_str;
 extern PyObject *_PyIO_empty_bytes;
-extern PyObject *_PyIO_zero;
 
 extern PyTypeObject _PyBytesIOBuffer_Type;

Modules/_io/textio.c

@@ -1078,7 +1078,7 @@ _io_TextIOWrapper___init___impl(textio *self, PyObject *buffer,
         if (cookieObj == NULL)
             goto error;
 
-        cmp = PyObject_RichCompareBool(cookieObj, _PyIO_zero, Py_EQ);
+        cmp = PyObject_RichCompareBool(cookieObj, _PyLong_Zero, Py_EQ);
         Py_DECREF(cookieObj);
         if (cmp < 0) {
             goto error;
@@ -1087,7 +1087,7 @@ _io_TextIOWrapper___init___impl(textio *self, PyObject *buffer,
         if (cmp == 0) {
             self->encoding_start_of_stream = 0;
             res = PyObject_CallMethodObjArgs(self->encoder, _PyIO_str_setstate,
-                                             _PyIO_zero, NULL);
+                                             _PyLong_Zero, NULL);
             if (res == NULL)
                 goto error;
             Py_DECREF(res);
@@ -2030,7 +2030,7 @@ _textiowrapper_encoder_reset(textio *self, int start_of_stream)
     }
     else {
         res = PyObject_CallMethodObjArgs(self->encoder, _PyIO_str_setstate,
-                                         _PyIO_zero, NULL);
+                                         _PyLong_Zero, NULL);
         self->encoding_start_of_stream = 0;
     }
     if (res == NULL)
@@ -2075,7 +2075,7 @@ _io_TextIOWrapper_seek_impl(textio *self, PyObject *cookieObj, int whence)
 
     if (whence == 1) {
         /* seek relative to current position */
-        cmp = PyObject_RichCompareBool(cookieObj, _PyIO_zero, Py_EQ);
+        cmp = PyObject_RichCompareBool(cookieObj, _PyLong_Zero, Py_EQ);
         if (cmp < 0)
             goto fail;
 
@@ -2094,7 +2094,7 @@ _io_TextIOWrapper_seek_impl(textio *self, PyObject *cookieObj, int whence)
     }
     else if (whence == 2) {
         /* seek relative to end of file */
-        cmp = PyObject_RichCompareBool(cookieObj, _PyIO_zero, Py_EQ);
+        cmp = PyObject_RichCompareBool(cookieObj, _PyLong_Zero, Py_EQ);
         if (cmp < 0)
             goto fail;
 
@@ -2123,7 +2123,7 @@ _io_TextIOWrapper_seek_impl(textio *self, PyObject *cookieObj, int whence)
             goto fail;
         if (self->encoder) {
             /* If seek() == 0, we are at the start of stream, otherwise not */
-            cmp = PyObject_RichCompareBool(res, _PyIO_zero, Py_EQ);
+            cmp = PyObject_RichCompareBool(res, _PyLong_Zero, Py_EQ);
             if (cmp < 0 || _textiowrapper_encoder_reset(self, cmp)) {
                 Py_DECREF(res);
                 goto fail;
@@ -2137,7 +2137,7 @@ _io_TextIOWrapper_seek_impl(textio *self, PyObject *cookieObj, int whence)
         goto fail;
     }
 
-    cmp = PyObject_RichCompareBool(cookieObj, _PyIO_zero, Py_LT);
+    cmp = PyObject_RichCompareBool(cookieObj, _PyLong_Zero, Py_LT);
     if (cmp < 0)
         goto fail;
 

Modules/_sre.c

@@ -2041,7 +2041,7 @@ match_group(MatchObject* self, PyObject* args)
 
     switch (size) {
     case 0:
-        result = match_getslice(self, Py_False, Py_None);
+        result = match_getslice(self, _PyLong_Zero, Py_None);
         break;
     case 1:
         result = match_getslice(self, PyTuple_GET_ITEM(args, 0), Py_None);

Modules/itertoolsmodule.c

@@ -3965,24 +3965,16 @@ count_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
                 fast_mode = 0;
             }
         }
-        Py_INCREF(long_cnt);
     } else {
         cnt = 0;
-        long_cnt = PyLong_FromLong(0);
-        if (long_cnt == NULL) {
-            return NULL;
-        }
+        long_cnt = _PyLong_Zero;
     }
+    Py_INCREF(long_cnt);
 
     /* If not specified, step defaults to 1 */
-    if (long_step == NULL) {
-        long_step = PyLong_FromLong(1);
-        if (long_step == NULL) {
-            Py_DECREF(long_cnt);
-            return NULL;
-        }
-    } else
-        Py_INCREF(long_step);
+    if (long_step == NULL)
+        long_step = _PyLong_One;
+    Py_INCREF(long_step);
 
     assert(long_cnt != NULL && long_step != NULL);
 

Objects/complexobject.c

@@ -936,7 +936,7 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
 /*[clinic input]
 @classmethod
 complex.__new__ as complex_new
-    real as r: object(c_default="Py_False") = 0
+    real as r: object(c_default="_PyLong_Zero") = 0
     imag as i: object(c_default="NULL") = 0
 
 Create a complex number from a real part and an optional imaginary part.

Objects/enumobject.c

@@ -100,7 +100,6 @@ enum_traverse(enumobject *en, visitproc visit, void *arg)
 static PyObject *
 enum_next_long(enumobject *en, PyObject* next_item)
 {
-    static PyObject *one = NULL;
     PyObject *result = en->en_result;
     PyObject *next_index;
     PyObject *stepped_up;
@@ -110,14 +109,9 @@ enum_next_long(enumobject *en, PyObject* next_item)
         if (en->en_longindex == NULL)
             return NULL;
     }
-    if (one == NULL) {
-        one = PyLong_FromLong(1);
-        if (one == NULL)
-            return NULL;
-    }
     next_index = en->en_longindex;
     assert(next_index != NULL);
-    stepped_up = PyNumber_Add(next_index, one);
+    stepped_up = PyNumber_Add(next_index, _PyLong_One);
     if (stepped_up == NULL)
         return NULL;
     en->en_longindex = stepped_up;

Objects/floatobject.c

@@ -443,7 +443,6 @@ float_richcompare(PyObject *v, PyObject *w, int op)
             double fracpart;
             double intpart;
             PyObject *result = NULL;
-            PyObject *one = NULL;
             PyObject *vv = NULL;
             PyObject *ww = w;
 
@@ -466,23 +465,19 @@ float_richcompare(PyObject *v, PyObject *w, int op)
                  */
                 PyObject *temp;
 
-                one = PyLong_FromLong(1);
-                if (one == NULL)
-                    goto Error;
-
-                temp = PyNumber_Lshift(ww, one);
+                temp = PyNumber_Lshift(ww, _PyLong_One);
                 if (temp == NULL)
                     goto Error;
                 Py_DECREF(ww);
                 ww = temp;
 
-                temp = PyNumber_Lshift(vv, one);
+                temp = PyNumber_Lshift(vv, _PyLong_One);
                 if (temp == NULL)
                     goto Error;
                 Py_DECREF(vv);
                 vv = temp;
 
-                temp = PyNumber_Or(vv, one);
+                temp = PyNumber_Or(vv, _PyLong_One);
                 if (temp == NULL)
                     goto Error;
                 Py_DECREF(vv);
@@ -496,7 +491,6 @@ float_richcompare(PyObject *v, PyObject *w, int op)
          Error:
             Py_XDECREF(vv);
             Py_XDECREF(ww);
-            Py_XDECREF(one);
             return result;
         }
     } /* else if (PyLong_Check(w)) */
@@ -1617,7 +1611,7 @@ float_subtype_new(PyTypeObject *type, PyObject *x);
 /*[clinic input]
 @classmethod
 float.__new__ as float_new
-    x: object(c_default="Py_False") = 0
+    x: object(c_default="_PyLong_Zero") = 0
     /
 
 Convert a string or number to a floating point number, if possible.