Fix PyLong digits access in CPython 3.12.

Needed after python/cpython#101292

See cython#5238

Author: scoder

Cython/Utility/Builtins.c

@@ -247,7 +247,7 @@ static PyObject *__Pyx_PyLong_AbsNeg(PyObject *num);/*proto*/
 static PyObject *__Pyx_PyLong_AbsNeg(PyObject *n) {
     if (likely(Py_SIZE(n) == -1)) {
         // digits are unsigned
-        return PyLong_FromLong(((PyLongObject*)n)->ob_digit[0]);
+        return PyLong_FromLong(__Pyx_PyLong_Digits(n)[0]);
     }
 #if CYTHON_COMPILING_IN_CPYTHON
     {

Cython/Utility/Optimize.c

@@ -977,7 +977,7 @@ static PyObject* __Pyx__PyNumber_PowerOf2(PyObject *two, PyObject *exp, PyObject
         const Py_ssize_t size = Py_SIZE(exp);
         // tuned to optimise branch prediction
         if (likely(size == 1)) {
-            shiftby = ((PyLongObject*)exp)->ob_digit[0];
+            shiftby = __Pyx_PyLong_Digits(exp)[0];
         } else if (size == 0) {
             return PyInt_FromLong(1L);
         } else if (unlikely(size < 0)) {
@@ -1058,7 +1058,7 @@ static CYTHON_INLINE {{c_ret_type}} __Pyx_PyInt_{{'' if ret_type.is_pyobject els
         int unequal;
         unsigned long uintval;
         Py_ssize_t size = Py_SIZE({{pyval}});
-        const digit* digits = ((PyLongObject*){{pyval}})->ob_digit;
+        const digit* digits = __Pyx_PyLong_Digits({{pyval}});
         if (intval == 0) {
             // == 0  =>  Py_SIZE(pyval) == 0
             {{return_compare('size', '0', c_op)}}
@@ -1237,7 +1237,7 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, long intval,
         PY_LONG_LONG ll{{ival}}, llx;
 #endif
         {{endif}}
-        const digit* digits = ((PyLongObject*){{pyval}})->ob_digit;
+        const digit* digits = __Pyx_PyLong_Digits({{pyval}});
         const Py_ssize_t size = Py_SIZE({{pyval}});
         {{if c_op == '&'}}
         // special case for &-ing arbitrarily large numbers with known single digit operands
@@ -1492,7 +1492,7 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, double floatv
 
     if (likely(PyLong_CheckExact({{pyval}}))) {
         #if CYTHON_USE_PYLONG_INTERNALS
-        const digit* digits = ((PyLongObject*){{pyval}})->ob_digit;
+        const digit* digits = __Pyx_PyLong_Digits({{pyval}});
         const Py_ssize_t size = Py_SIZE({{pyval}});
         switch (size) {
             case  0: {{fval}} = 0.0; {{zerodiv_check(fval)}} break;

Cython/Utility/StringTools.c

@@ -1065,7 +1065,7 @@ static CYTHON_INLINE int __Pyx_PyByteArray_AppendObject(PyObject* bytearray, PyO
         if (Py_SIZE(value) == 0) {
             ival = 0;
         } else {
-            ival = ((PyLongObject*)value)->ob_digit[0];
+            ival = __Pyx_PyLong_Digits(value)[0];
             if (unlikely(ival > 255)) goto bad_range;
         }
     } else

Cython/Utility/TypeConversion.c

@@ -129,6 +129,14 @@ static CYTHON_INLINE Py_hash_t __Pyx_PyIndex_AsHash_t(PyObject*);
 // __Pyx_PyNumber_Float is now in it's own section since it has dependencies (needed to make
 // string conversion work the same in all circumstances)
 
+#if CYTHON_USE_PYLONG_INTERNALS
+  #if PY_VERSION_HEX >= 0x030C00A5
+  #define __Pyx_PyLong_Digits(x)  (((PyLongObject*)b)->long_value.ob_digit)
+  #else
+  #define __Pyx_PyLong_Digits(x)  (((PyLongObject*)b)->ob_digit)
+  #endif
+#endif
+
 #if PY_MAJOR_VERSION < 3 && __PYX_DEFAULT_STRING_ENCODING_IS_ASCII
 static int __Pyx_sys_getdefaultencoding_not_ascii;
 static int __Pyx_init_sys_getdefaultencoding_params(void) {
@@ -405,7 +413,7 @@ static CYTHON_INLINE Py_ssize_t __Pyx_PyIndex_AsSsize_t(PyObject* b) {
 #endif
   if (likely(PyLong_CheckExact(b))) {
     #if CYTHON_USE_PYLONG_INTERNALS
-    const digit* digits = ((PyLongObject*)b)->ob_digit;
+    const digit* digits = __Pyx_PyLong_Digits(b);
     const Py_ssize_t size = Py_SIZE(b);
     // handle most common case first to avoid indirect branch and optimise branch prediction
     if (likely(__Pyx_sst_abs(size) <= 1)) {
@@ -478,7 +486,7 @@ static CYTHON_INLINE PyObject* __Pyx__PyNumber_Float(PyObject* obj) {
     double val;
     if (PyLong_CheckExact(obj)) {
 #if CYTHON_USE_PYLONG_INTERNALS
-        const digit* digits = ((PyLongObject*)obj)->ob_digit;
+        const digit* digits = __Pyx_PyLong_Digits(obj);
         switch (Py_SIZE(obj)) {
             case 0:
                 val = 0.0;
@@ -968,7 +976,7 @@ static CYTHON_INLINE {{TYPE}} {{FROM_PY_FUNCTION}}(PyObject *x) {
     if (likely(PyLong_Check(x))) {
         if (is_unsigned) {
 #if CYTHON_USE_PYLONG_INTERNALS
-            const digit* digits = ((PyLongObject*)x)->ob_digit;
+            const digit* digits = __Pyx_PyLong_Digits(x);
             switch (Py_SIZE(x)) {
                 case  0: return ({{TYPE}}) 0;
                 case  1: __PYX_VERIFY_RETURN_INT({{TYPE}}, digit, digits[0])
@@ -1009,7 +1017,7 @@ static CYTHON_INLINE {{TYPE}} {{FROM_PY_FUNCTION}}(PyObject *x) {
         } else {
             // signed
 #if CYTHON_USE_PYLONG_INTERNALS
-            const digit* digits = ((PyLongObject*)x)->ob_digit;
+            const digit* digits = __Pyx_PyLong_Digits(x);
             switch (Py_SIZE(x)) {
                 case  0: return ({{TYPE}}) 0;
                 case -1: __PYX_VERIFY_RETURN_INT({{TYPE}}, sdigit, (sdigit) (-(sdigit)digits[0]))