Support python 3.12

Author: tornaria

src/fpylll/gmp/pycore_long.h

@@ -0,0 +1,98 @@
+#include "Python.h"
+#include <stdbool.h>
+
+#if PY_VERSION_HEX >= 0x030C00A5
+#define ob_digit(o)  (((PyLongObject*)o)->long_value.ob_digit)
+#else
+#define ob_digit(o)  (((PyLongObject*)o)->ob_digit)
+#endif
+
+#if PY_VERSION_HEX >= 0x030C00A7
+// taken from cpython:Include/internal/pycore_long.h @ 3.12
+
+/* Long value tag bits:
+ * 0-1: Sign bits value = (1-sign), ie. negative=2, positive=0, zero=1.
+ * 2: Reserved for immortality bit
+ * 3+ Unsigned digit count
+ */
+#define SIGN_MASK 3
+#define SIGN_ZERO 1
+#define SIGN_NEGATIVE 2
+#define NON_SIZE_BITS 3
+
+static inline bool
+_PyLong_IsZero(const PyLongObject *op)
+{
+    return (op->long_value.lv_tag & SIGN_MASK) == SIGN_ZERO;
+}
+
+static inline bool
+_PyLong_IsNegative(const PyLongObject *op)
+{
+    return (op->long_value.lv_tag & SIGN_MASK) == SIGN_NEGATIVE;
+}
+
+static inline bool
+_PyLong_IsPositive(const PyLongObject *op)
+{
+    return (op->long_value.lv_tag & SIGN_MASK) == 0;
+}
+
+static inline Py_ssize_t
+_PyLong_DigitCount(const PyLongObject *op)
+{
+    assert(PyLong_Check(op));
+    return op->long_value.lv_tag >> NON_SIZE_BITS;
+}
+
+#define TAG_FROM_SIGN_AND_SIZE(sign, size) ((1 - (sign)) | ((size) << NON_SIZE_BITS))
+
+static inline void
+_PyLong_SetSignAndDigitCount(PyLongObject *op, int sign, Py_ssize_t size)
+{
+    assert(size >= 0);
+    assert(-1 <= sign && sign <= 1);
+    assert(sign != 0 || size == 0);
+    op->long_value.lv_tag = TAG_FROM_SIGN_AND_SIZE(sign, (size_t)size);
+}
+
+#else
+// fallback for < 3.12
+
+static inline bool
+_PyLong_IsZero(const PyLongObject *op)
+{
+    return Py_SIZE(op) == 0;
+}
+
+static inline bool
+_PyLong_IsNegative(const PyLongObject *op)
+{
+    return Py_SIZE(op) < 0;
+}
+
+static inline bool
+_PyLong_IsPositive(const PyLongObject *op)
+{
+    return Py_SIZE(op) > 0;
+}
+
+static inline Py_ssize_t
+_PyLong_DigitCount(const PyLongObject *op)
+{
+    Py_ssize_t size = Py_SIZE(op);
+    return size < 0 ? -size : size;
+}
+
+static inline void
+_PyLong_SetSignAndDigitCount(PyLongObject *op, int sign, Py_ssize_t size)
+{
+#if (PY_MAJOR_VERSION == 3) && (PY_MINOR_VERSION < 9)
+// The function Py_SET_SIZE is defined starting with python 3.9.
+    Py_SIZE(o) = size;
+#else
+    Py_SET_SIZE(op, sign < 0 ? -size : size);
+#endif
+}
+
+#endif

src/fpylll/gmp/pycore_long.pxd

@@ -0,0 +1,9 @@
+from cpython.longintrepr cimport py_long, digit
+
+cdef extern from "pycore_long.h":
+    digit* ob_digit(py_long o)
+    bint _PyLong_IsZero(py_long o)
+    bint _PyLong_IsNegative(py_long o)
+    bint _PyLong_IsPositive(py_long o)
+    Py_ssize_t _PyLong_DigitCount(py_long o)
+    void _PyLong_SetSignAndDigitCount(py_long o, int sign, Py_ssize_t size)

src/fpylll/gmp/pylong.pxd

@@ -3,23 +3,10 @@
 Various functions to deal with conversion mpz <-> Python int/long
 """
 
-cdef extern from "Python.h":
-    cdef _PyLong_New(Py_ssize_t s)
-    cdef long PyLong_SHIFT
-    ctypedef unsigned int digit
-    ctypedef struct PyLongObject:
-        digit* ob_digit
-
-    ctypedef struct PyObject:
-        pass
-
-    ctypedef struct PyVarObject:
-        PyObject ob_base
-        Py_ssize_t ob_size
-
+from cpython.longintrepr cimport py_long
 from fpylll.gmp.types cimport *
 
 cdef mpz_get_pylong(mpz_srcptr z)
 cdef mpz_get_pyintlong(mpz_srcptr z)
-cdef int mpz_set_pylong(mpz_ptr z, L) except -1
+cdef int mpz_set_pylong(mpz_ptr z, py_long L) except -1
 cdef Py_hash_t mpz_pythonhash(mpz_srcptr z)

src/fpylll/gmp/pylong.pyx

@@ -28,6 +28,9 @@ AUTHORS:
 
 from cpython.int cimport PyInt_FromLong
 from cpython.long cimport PyLong_CheckExact, PyLong_FromLong
+from cpython.longintrepr cimport _PyLong_New, digit, PyLong_SHIFT
+from .pycore_long cimport (ob_digit, _PyLong_IsZero, _PyLong_IsNegative,
+        _PyLong_IsPositive, _PyLong_DigitCount, _PyLong_SetSignAndDigitCount)
 from .mpz cimport *
 
 # Unused bits in every PyLong digit
@@ -40,11 +43,9 @@ cdef mpz_get_pylong_large(mpz_srcptr z):
     """
     cdef size_t nbits = mpz_sizeinbase(z, 2)
     cdef size_t pylong_size = (nbits + PyLong_SHIFT - 1) // PyLong_SHIFT
-    L = _PyLong_New(pylong_size)
-    mpz_export((<PyLongObject*>L).ob_digit, NULL,
-            -1, sizeof(digit), 0, PyLong_nails, z)
-    if mpz_sgn(z) < 0:
-        (<PyVarObject*>L).ob_size = -(<PyVarObject*>L).ob_size
+    cdef py_long L = _PyLong_New(pylong_size)
+    mpz_export(ob_digit(L), NULL, -1, sizeof(digit), 0, PyLong_nails, z)
+    _PyLong_SetSignAndDigitCount(L, mpz_sgn(z), pylong_size)
     return L
 
 
@@ -67,16 +68,13 @@ cdef mpz_get_pyintlong(mpz_srcptr z):
     return mpz_get_pylong_large(z)
 
 
-cdef int mpz_set_pylong(mpz_ptr z, L) except -1:
+cdef int mpz_set_pylong(mpz_ptr z, py_long L) except -1:
     """
     Convert a Python ``long`` `L` to an ``mpz``.
     """
-    cdef Py_ssize_t pylong_size = (<PyVarObject*>L).ob_size
-    if pylong_size < 0:
-        pylong_size = -pylong_size
-    mpz_import(z, pylong_size, -1, sizeof(digit), 0, PyLong_nails,
-            (<PyLongObject*>L).ob_digit)
-    if (<PyVarObject*>L).ob_size < 0:
+    cdef Py_ssize_t pylong_size = _PyLong_DigitCount(L)
+    mpz_import(z, pylong_size, -1, sizeof(digit), 0, PyLong_nails, ob_digit(L))
+    if _PyLong_IsNegative(L):
         mpz_neg(z, z)