gh-106320: Re-add some PyLong/PyDict C-API functions (GH-#111162)

* gh-106320: Re-add _PyLong_FromByteArray(), _PyLong_AsByteArray() and _PyLong_GCD() to the public header files since they are used by third-party packages and there is no efficient replacement.

See https://github.com/python/cpython/issues/111140
See https://github.com/python/cpython/issues/111139

* gh-111262: Re-add _PyDict_Pop() to have a C-API until a new public one is designed.

2 files changed, 43 insertions, 0 deletions

diff --git a/Include/cpython/dictobject.h b/Include/cpython/dictobject.h
index b05ca3e..64a4042 100644
--- a/Include/cpython/dictobject.h
+++ b/Include/cpython/dictobject.h
@@ -46,6 +46,7 @@ static inline Py_ssize_t PyDict_GET_SIZE(PyObject *op) {
 
 PyAPI_FUNC(int) PyDict_ContainsString(PyObject *mp, const char *key);
 
+PyAPI_FUNC(PyObject *) _PyDict_Pop(PyObject *dict, PyObject *key, PyObject *default_value);
 
 /* Dictionary watchers */
 
diff --git a/Include/cpython/longobject.h b/Include/cpython/longobject.h
index 5783417..ab885cf 100644
--- a/Include/cpython/longobject.h
+++ b/Include/cpython/longobject.h
@@ -7,3 +7,45 @@ PyAPI_FUNC(PyObject*) PyLong_FromUnicodeObject(PyObject *u, int base);
 PyAPI_FUNC(int) PyUnstable_Long_IsCompact(const PyLongObject* op);
 PyAPI_FUNC(Py_ssize_t) PyUnstable_Long_CompactValue(const PyLongObject* op);
 
+/* _PyLong_FromByteArray:  View the n unsigned bytes as a binary integer in
+   base 256, and return a Python int with the same numeric value.
+   If n is 0, the integer is 0.  Else:
+   If little_endian is 1/true, bytes[n-1] is the MSB and bytes[0] the LSB;
+   else (little_endian is 0/false) bytes[0] is the MSB and bytes[n-1] the
+   LSB.
+   If is_signed is 0/false, view the bytes as a non-negative integer.
+   If is_signed is 1/true, view the bytes as a 2's-complement integer,
+   non-negative if bit 0x80 of the MSB is clear, negative if set.
+   Error returns:
+   + Return NULL with the appropriate exception set if there's not
+     enough memory to create the Python int.
+*/
+PyAPI_FUNC(PyObject *) _PyLong_FromByteArray(
+    const unsigned char* bytes, size_t n,
+    int little_endian, int is_signed);
+
+/* _PyLong_AsByteArray: Convert the least-significant 8*n bits of long
+   v to a base-256 integer, stored in array bytes.  Normally return 0,
+   return -1 on error.
+   If little_endian is 1/true, store the MSB at bytes[n-1] and the LSB at
+   bytes[0]; else (little_endian is 0/false) store the MSB at bytes[0] and
+   the LSB at bytes[n-1].
+   If is_signed is 0/false, it's an error if v < 0; else (v >= 0) n bytes
+   are filled and there's nothing special about bit 0x80 of the MSB.
+   If is_signed is 1/true, bytes is filled with the 2's-complement
+   representation of v's value.  Bit 0x80 of the MSB is the sign bit.
+   Error returns (-1):
+   + is_signed is 0 and v < 0.  TypeError is set in this case, and bytes
+     isn't altered.
+   + n isn't big enough to hold the full mathematical value of v.  For
+     example, if is_signed is 0 and there are more digits in the v than
+     fit in n; or if is_signed is 1, v < 0, and n is just 1 bit shy of
+     being large enough to hold a sign bit.  OverflowError is set in this
+     case, but bytes holds the least-significant n bytes of the true value.
+*/
+PyAPI_FUNC(int) _PyLong_AsByteArray(PyLongObject* v,
+    unsigned char* bytes, size_t n,
+    int little_endian, int is_signed);
+
+/* For use by the gcd function in mathmodule.c */
+PyAPI_FUNC(PyObject *) _PyLong_GCD(PyObject *, PyObject *);