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-rw-r--r--Doc/c-api/long.rst66
-rw-r--r--Doc/whatsnew/3.13.rst7
-rw-r--r--Include/cpython/longobject.h36
-rw-r--r--Lib/test/test_capi/test_long.py145
-rw-r--r--Misc/NEWS.d/next/C API/2024-02-05-17-11-15.gh-issue-111140.WMEjid.rst2
-rw-r--r--Modules/_io/textio.c2
-rw-r--r--Modules/_pickle.c3
-rw-r--r--Modules/_randommodule.c3
-rw-r--r--Modules/_sqlite/util.c2
-rw-r--r--Modules/_struct.c20
-rw-r--r--Modules/_testcapi/long.c48
-rw-r--r--Modules/_tkinter.c3
-rw-r--r--Modules/cjkcodecs/multibytecodec.c6
-rw-r--r--Objects/longobject.c216
14 files changed, 533 insertions, 26 deletions
diff --git a/Doc/c-api/long.rst b/Doc/c-api/long.rst
index f42e23d..c39823e 100644
--- a/Doc/c-api/long.rst
+++ b/Doc/c-api/long.rst
@@ -113,6 +113,28 @@ distinguished from a number. Use :c:func:`PyErr_Occurred` to disambiguate.
retrieved from the resulting value using :c:func:`PyLong_AsVoidPtr`.
+.. c:function:: PyObject* PyLong_FromNativeBytes(const void* buffer, size_t n_bytes, int endianness)
+
+ Create a Python integer from the value contained in the first *n_bytes* of
+ *buffer*, interpreted as a two's-complement signed number.
+
+ *endianness* may be passed ``-1`` for the native endian that CPython was
+ compiled with, or else ``0`` for big endian and ``1`` for little.
+
+ .. versionadded:: 3.13
+
+
+.. c:function:: PyObject* PyLong_FromUnsignedNativeBytes(const void* buffer, size_t n_bytes, int endianness)
+
+ Create a Python integer from the value contained in the first *n_bytes* of
+ *buffer*, interpreted as an unsigned number.
+
+ *endianness* may be passed ``-1`` for the native endian that CPython was
+ compiled with, or else ``0`` for big endian and ``1`` for little.
+
+ .. versionadded:: 3.13
+
+
.. XXX alias PyLong_AS_LONG (for now)
.. c:function:: long PyLong_AsLong(PyObject *obj)
@@ -332,6 +354,50 @@ distinguished from a number. Use :c:func:`PyErr_Occurred` to disambiguate.
Returns ``NULL`` on error. Use :c:func:`PyErr_Occurred` to disambiguate.
+.. c:function:: Py_ssize_t PyLong_AsNativeBytes(PyObject *pylong, void* buffer, Py_ssize_t n_bytes, int endianness)
+
+ Copy the Python integer value to a native *buffer* of size *n_bytes*::
+
+ int value;
+ Py_ssize_t bytes = PyLong_CopyBits(v, &value, sizeof(value), -1);
+ if (bytes < 0) {
+ // Error occurred
+ return NULL;
+ }
+ else if (bytes > sizeof(value)) {
+ // Overflow occurred, but 'value' contains as much as could fit
+ }
+
+ *endianness* may be passed ``-1`` for the native endian that CPython was
+ compiled with, or ``0`` for big endian and ``1`` for little.
+
+ Return ``-1`` with an exception raised if *pylong* cannot be interpreted as
+ an integer. Otherwise, return the size of the buffer required to store the
+ value. If this is equal to or less than *n_bytes*, the entire value was
+ copied.
+
+ Unless an exception is raised, all *n_bytes* of the buffer will be written
+ with as much of the value as can fit. This allows the caller to ignore all
+ non-negative results if the intent is to match the typical behavior of a
+ C-style downcast.
+
+ Values are always copied as twos-complement, and sufficient size will be
+ requested for a sign bit. For example, this may cause an value that fits into
+ 8 bytes when treated as unsigned to request 9 bytes, even though all eight
+ bytes were copied into the buffer. What has been omitted is the zero sign
+ bit, which is redundant when the intention is to treat the value as unsigned.
+
+ Passing *n_bytes* of zero will always return the requested buffer size.
+
+ .. note::
+
+ When the value does not fit in the provided buffer, the requested size
+ returned from the function may be larger than necessary. Passing 0 to this
+ function is not an accurate way to determine the bit length of a value.
+
+ .. versionadded:: 3.13
+
+
.. c:function:: int PyUnstable_Long_IsCompact(const PyLongObject* op)
Return 1 if *op* is compact, 0 otherwise.
diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index 1916570..b96720d 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -587,6 +587,7 @@ Tier 2 IR by Mark Shannon and Guido van Rossum.
Tier 2 optimizer by Ken Jin.)
+
Deprecated
==========
@@ -1526,6 +1527,11 @@ New Features
(Contributed by Victor Stinner and Petr Viktorin in :gh:`110850`.)
+* Add :c:func:`PyLong_AsNativeBytes`, :c:func:`PyLong_FromNativeBytes` and
+ :c:func:`PyLong_FromUnsignedNativeBytes` functions to simplify converting
+ between native integer types and Python :class:`int` objects.
+ (Contributed by Steve Dower in :gh:`111140`.)
+
Porting to Python 3.13
----------------------
@@ -1585,7 +1591,6 @@ Porting to Python 3.13
platforms, the ``HAVE_STDDEF_H`` macro is only defined on Windows.
(Contributed by Victor Stinner in :gh:`108765`.)
-
Deprecated
----------
diff --git a/Include/cpython/longobject.h b/Include/cpython/longobject.h
index fd1be29..07251db 100644
--- a/Include/cpython/longobject.h
+++ b/Include/cpython/longobject.h
@@ -4,6 +4,40 @@
PyAPI_FUNC(PyObject*) PyLong_FromUnicodeObject(PyObject *u, int base);
+/* PyLong_AsNativeBytes: Copy the integer value to a native variable.
+ buffer points to the first byte of the variable.
+ n_bytes is the number of bytes available in the buffer. Pass 0 to request
+ the required size for the value.
+ endianness is -1 for native endian, 0 for big endian or 1 for little.
+ Big endian mode will write the most significant byte into the address
+ directly referenced by buffer; little endian will write the least significant
+ byte into that address.
+
+ If an exception is raised, returns a negative value.
+ Otherwise, returns the number of bytes that are required to store the value.
+ To check that the full value is represented, ensure that the return value is
+ equal or less than n_bytes.
+ All n_bytes are guaranteed to be written (unless an exception occurs), and
+ so ignoring a positive return value is the equivalent of a downcast in C.
+ In cases where the full value could not be represented, the returned value
+ may be larger than necessary - this function is not an accurate way to
+ calculate the bit length of an integer object.
+ */
+PyAPI_FUNC(Py_ssize_t) PyLong_AsNativeBytes(PyObject* v, void* buffer,
+ Py_ssize_t n_bytes, int endianness);
+
+/* PyLong_FromNativeBytes: Create an int value from a native integer
+ n_bytes is the number of bytes to read from the buffer. Passing 0 will
+ always produce the zero int.
+ PyLong_FromUnsignedNativeBytes always produces a non-negative int.
+ endianness is -1 for native endian, 0 for big endian or 1 for little.
+
+ Returns the int object, or NULL with an exception set. */
+PyAPI_FUNC(PyObject*) PyLong_FromNativeBytes(const void* buffer, size_t n_bytes,
+ int endianness);
+PyAPI_FUNC(PyObject*) PyLong_FromUnsignedNativeBytes(const void* buffer,
+ size_t n_bytes, int endianness);
+
PyAPI_FUNC(int) PyUnstable_Long_IsCompact(const PyLongObject* op);
PyAPI_FUNC(Py_ssize_t) PyUnstable_Long_CompactValue(const PyLongObject* op);
@@ -50,7 +84,7 @@ PyAPI_FUNC(PyObject *) _PyLong_FromByteArray(
*/
PyAPI_FUNC(int) _PyLong_AsByteArray(PyLongObject* v,
unsigned char* bytes, size_t n,
- int little_endian, int is_signed);
+ int little_endian, int is_signed, int with_exceptions);
/* For use by the gcd function in mathmodule.c */
PyAPI_FUNC(PyObject *) _PyLong_GCD(PyObject *, PyObject *);
diff --git a/Lib/test/test_capi/test_long.py b/Lib/test/test_capi/test_long.py
index 8e3ef25..fc82cbf 100644
--- a/Lib/test/test_capi/test_long.py
+++ b/Lib/test/test_capi/test_long.py
@@ -1,5 +1,6 @@
import unittest
import sys
+import test.support as support
from test.support import import_helper
@@ -423,6 +424,150 @@ class LongTests(unittest.TestCase):
self.assertRaises(OverflowError, asvoidptr, -2**1000)
# CRASHES asvoidptr(NULL)
+ def test_long_asnativebytes(self):
+ import math
+ from _testcapi import (
+ pylong_asnativebytes as asnativebytes,
+ SIZE_MAX,
+ )
+
+ # Abbreviate sizeof(Py_ssize_t) to SZ because we use it a lot
+ SZ = int(math.ceil(math.log(SIZE_MAX + 1) / math.log(2)) / 8)
+ MAX_SSIZE = 2 ** (SZ * 8 - 1) - 1
+ MAX_USIZE = 2 ** (SZ * 8) - 1
+ if support.verbose:
+ print(f"SIZEOF_SIZE={SZ}\n{MAX_SSIZE=:016X}\n{MAX_USIZE=:016X}")
+
+ # These tests check that the requested buffer size is correct
+ for v, expect in [
+ (0, SZ),
+ (512, SZ),
+ (-512, SZ),
+ (MAX_SSIZE, SZ),
+ (MAX_USIZE, SZ + 1),
+ (-MAX_SSIZE, SZ),
+ (-MAX_USIZE, SZ + 1),
+ (2**255-1, 32),
+ (-(2**255-1), 32),
+ (2**256-1, 33),
+ (-(2**256-1), 33),
+ ]:
+ with self.subTest(f"sizeof-{v:X}"):
+ buffer = bytearray(1)
+ self.assertEqual(expect, asnativebytes(v, buffer, 0, -1),
+ "PyLong_AsNativeBytes(v, NULL, 0, -1)")
+ # Also check via the __index__ path
+ self.assertEqual(expect, asnativebytes(Index(v), buffer, 0, -1),
+ "PyLong_AsNativeBytes(Index(v), NULL, 0, -1)")
+
+ # We request as many bytes as `expect_be` contains, and always check
+ # the result (both big and little endian). We check the return value
+ # independently, since the buffer should always be filled correctly even
+ # if we need more bytes
+ for v, expect_be, expect_n in [
+ (0, b'\x00', 1),
+ (0, b'\x00' * 2, 2),
+ (0, b'\x00' * 8, min(8, SZ)),
+ (1, b'\x01', 1),
+ (1, b'\x00' * 10 + b'\x01', min(11, SZ)),
+ (42, b'\x2a', 1),
+ (42, b'\x00' * 10 + b'\x2a', min(11, SZ)),
+ (-1, b'\xff', 1),
+ (-1, b'\xff' * 10, min(11, SZ)),
+ (-42, b'\xd6', 1),
+ (-42, b'\xff' * 10 + b'\xd6', min(11, SZ)),
+ # Extracts 255 into a single byte, but requests sizeof(Py_ssize_t)
+ (255, b'\xff', SZ),
+ (255, b'\x00\xff', 2),
+ (256, b'\x01\x00', 2),
+ # Extracts successfully (unsigned), but requests 9 bytes
+ (2**63, b'\x80' + b'\x00' * 7, 9),
+ # "Extracts", but requests 9 bytes
+ (-2**63, b'\x80' + b'\x00' * 7, 9),
+ (2**63, b'\x00\x80' + b'\x00' * 7, 9),
+ (-2**63, b'\xff\x80' + b'\x00' * 7, 9),
+
+ (2**255-1, b'\x7f' + b'\xff' * 31, 32),
+ (-(2**255-1), b'\x80' + b'\x00' * 30 + b'\x01', 32),
+ # Request extra bytes, but result says we only needed 32
+ (-(2**255-1), b'\xff\x80' + b'\x00' * 30 + b'\x01', 32),
+ (-(2**255-1), b'\xff\xff\x80' + b'\x00' * 30 + b'\x01', 32),
+
+ # Extracting 256 bits of integer will request 33 bytes, but still
+ # copy as many bits as possible into the buffer. So we *can* copy
+ # into a 32-byte buffer, though negative number may be unrecoverable
+ (2**256-1, b'\xff' * 32, 33),
+ (2**256-1, b'\x00' + b'\xff' * 32, 33),
+ (-(2**256-1), b'\x00' * 31 + b'\x01', 33),
+ (-(2**256-1), b'\xff' + b'\x00' * 31 + b'\x01', 33),
+ (-(2**256-1), b'\xff\xff' + b'\x00' * 31 + b'\x01', 33),
+
+ # The classic "Windows HRESULT as negative number" case
+ # HRESULT hr;
+ # PyLong_CopyBits(<-2147467259>, &hr, sizeof(HRESULT))
+ # assert(hr == E_FAIL)
+ (-2147467259, b'\x80\x00\x40\x05', 4),
+ ]:
+ with self.subTest(f"{v:X}-{len(expect_be)}bytes"):
+ n = len(expect_be)
+ buffer = bytearray(n)
+ expect_le = expect_be[::-1]
+
+ self.assertEqual(expect_n, asnativebytes(v, buffer, n, 0),
+ f"PyLong_AsNativeBytes(v, buffer, {n}, <big>)")
+ self.assertEqual(expect_be, buffer[:n], "<big>")
+ self.assertEqual(expect_n, asnativebytes(v, buffer, n, 1),
+ f"PyLong_AsNativeBytes(v, buffer, {n}, <little>)")
+ self.assertEqual(expect_le, buffer[:n], "<little>")
+
+ # Check a few error conditions. These are validated in code, but are
+ # unspecified in docs, so if we make changes to the implementation, it's
+ # fine to just update these tests rather than preserve the behaviour.
+ with self.assertRaises(SystemError):
+ asnativebytes(1, buffer, 0, 2)
+ with self.assertRaises(TypeError):
+ asnativebytes('not a number', buffer, 0, -1)
+
+ def test_long_fromnativebytes(self):
+ import math
+ from _testcapi import (
+ pylong_fromnativebytes as fromnativebytes,
+ SIZE_MAX,
+ )
+
+ # Abbreviate sizeof(Py_ssize_t) to SZ because we use it a lot
+ SZ = int(math.ceil(math.log(SIZE_MAX + 1) / math.log(2)) / 8)
+ MAX_SSIZE = 2 ** (SZ * 8 - 1) - 1
+ MAX_USIZE = 2 ** (SZ * 8) - 1
+
+ for v_be, expect_s, expect_u in [
+ (b'\x00', 0, 0),
+ (b'\x01', 1, 1),
+ (b'\xff', -1, 255),
+ (b'\x00\xff', 255, 255),
+ (b'\xff\xff', -1, 65535),
+ ]:
+ with self.subTest(f"{expect_s}-{expect_u:X}-{len(v_be)}bytes"):
+ n = len(v_be)
+ v_le = v_be[::-1]
+
+ self.assertEqual(expect_s, fromnativebytes(v_be, n, 0, 1),
+ f"PyLong_FromNativeBytes(buffer, {n}, <big>)")
+ self.assertEqual(expect_s, fromnativebytes(v_le, n, 1, 1),
+ f"PyLong_FromNativeBytes(buffer, {n}, <little>)")
+ self.assertEqual(expect_u, fromnativebytes(v_be, n, 0, 0),
+ f"PyLong_FromUnsignedNativeBytes(buffer, {n}, <big>)")
+ self.assertEqual(expect_u, fromnativebytes(v_le, n, 1, 0),
+ f"PyLong_FromUnsignedNativeBytes(buffer, {n}, <little>)")
+
+ # Check native endian when the result would be the same either
+ # way and we can test it.
+ if v_be == v_le:
+ self.assertEqual(expect_s, fromnativebytes(v_be, n, -1, 1),
+ f"PyLong_FromNativeBytes(buffer, {n}, <native>)")
+ self.assertEqual(expect_u, fromnativebytes(v_be, n, -1, 0),
+ f"PyLong_FromUnsignedNativeBytes(buffer, {n}, <native>)")
+
if __name__ == "__main__":
unittest.main()
diff --git a/Misc/NEWS.d/next/C API/2024-02-05-17-11-15.gh-issue-111140.WMEjid.rst b/Misc/NEWS.d/next/C API/2024-02-05-17-11-15.gh-issue-111140.WMEjid.rst
new file mode 100644
index 0000000..a8aa191
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2024-02-05-17-11-15.gh-issue-111140.WMEjid.rst
@@ -0,0 +1,2 @@
+Adds :c:func:`PyLong_AsNativeBytes`, :c:func:`PyLong_FromNativeBytes` and
+:c:func:`PyLong_FromUnsignedNativeBytes` functions.
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index d794af8..a3239ec 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -2393,7 +2393,7 @@ textiowrapper_parse_cookie(cookie_type *cookie, PyObject *cookieObj)
return -1;
if (_PyLong_AsByteArray(cookieLong, buffer, sizeof(buffer),
- PY_LITTLE_ENDIAN, 0) < 0) {
+ PY_LITTLE_ENDIAN, 0, 1) < 0) {
Py_DECREF(cookieLong);
return -1;
}
diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index f210c0c..0d83261 100644
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -2162,7 +2162,8 @@ save_long(PicklerObject *self, PyObject *obj)
pdata = (unsigned char *)PyBytes_AS_STRING(repr);
i = _PyLong_AsByteArray((PyLongObject *)obj,
pdata, nbytes,
- 1 /* little endian */ , 1 /* signed */ );
+ 1 /* little endian */ , 1 /* signed */ ,
+ 1 /* with exceptions */);
if (i < 0)
goto error;
/* If the int is negative, this may be a byte more than
diff --git a/Modules/_randommodule.c b/Modules/_randommodule.c
index 5481ed9..4463157 100644
--- a/Modules/_randommodule.c
+++ b/Modules/_randommodule.c
@@ -342,7 +342,8 @@ random_seed(RandomObject *self, PyObject *arg)
res = _PyLong_AsByteArray((PyLongObject *)n,
(unsigned char *)key, keyused * 4,
PY_LITTLE_ENDIAN,
- 0); /* unsigned */
+ 0, /* unsigned */
+ 1); /* with exceptions */
if (res == -1) {
goto Done;
}
diff --git a/Modules/_sqlite/util.c b/Modules/_sqlite/util.c
index 833a666..9e8613e 100644
--- a/Modules/_sqlite/util.c
+++ b/Modules/_sqlite/util.c
@@ -162,7 +162,7 @@ _pysqlite_long_as_int64(PyObject * py_val)
sqlite_int64 int64val;
if (_PyLong_AsByteArray((PyLongObject *)py_val,
(unsigned char *)&int64val, sizeof(int64val),
- IS_LITTLE_ENDIAN, 1 /* signed */) >= 0) {
+ IS_LITTLE_ENDIAN, 1 /* signed */, 0) >= 0) {
return int64val;
}
}
diff --git a/Modules/_struct.c b/Modules/_struct.c
index bd16fa8..fa2cd37 100644
--- a/Modules/_struct.c
+++ b/Modules/_struct.c
@@ -1000,9 +1000,10 @@ bp_longlong(_structmodulestate *state, char *p, PyObject *v, const formatdef *f)
(unsigned char *)p,
8,
0, /* little_endian */
- 1 /* signed */);
+ 1, /* signed */
+ 0 /* !with_exceptions */);
Py_DECREF(v);
- if (res == -1 && PyErr_Occurred()) {
+ if (res < 0) {
PyErr_Format(state->StructError,
"'%c' format requires %lld <= number <= %lld",
f->format,
@@ -1024,9 +1025,10 @@ bp_ulonglong(_structmodulestate *state, char *p, PyObject *v, const formatdef *f
(unsigned char *)p,
8,
0, /* little_endian */
- 0 /* signed */);
+ 0, /* signed */
+ 0 /* !with_exceptions */);
Py_DECREF(v);
- if (res == -1 && PyErr_Occurred()) {
+ if (res < 0) {
PyErr_Format(state->StructError,
"'%c' format requires 0 <= number <= %llu",
f->format,
@@ -1260,9 +1262,10 @@ lp_longlong(_structmodulestate *state, char *p, PyObject *v, const formatdef *f)
(unsigned char *)p,
8,
1, /* little_endian */
- 1 /* signed */);
+ 1, /* signed */
+ 0 /* !with_exceptions */);
Py_DECREF(v);
- if (res == -1 && PyErr_Occurred()) {
+ if (res < 0) {
PyErr_Format(state->StructError,
"'%c' format requires %lld <= number <= %lld",
f->format,
@@ -1284,9 +1287,10 @@ lp_ulonglong(_structmodulestate *state, char *p, PyObject *v, const formatdef *f
(unsigned char *)p,
8,
1, /* little_endian */
- 0 /* signed */);
+ 0, /* signed */
+ 0 /* !with_exceptions */);
Py_DECREF(v);
- if (res == -1 && PyErr_Occurred()) {
+ if (res < 0) {
PyErr_Format(state->StructError,
"'%c' format requires 0 <= number <= %llu",
f->format,
diff --git a/Modules/_testcapi/long.c b/Modules/_testcapi/long.c
index 32ad8d3..dc21cf9 100644
--- a/Modules/_testcapi/long.c
+++ b/Modules/_testcapi/long.c
@@ -776,6 +776,51 @@ pylong_asvoidptr(PyObject *module, PyObject *arg)
return Py_NewRef((PyObject *)value);
}
+static PyObject *
+pylong_asnativebytes(PyObject *module, PyObject *args)
+{
+ PyObject *v;
+ Py_buffer buffer;
+ Py_ssize_t n, endianness;
+ if (!PyArg_ParseTuple(args, "Ow*nn", &v, &buffer, &n, &endianness)) {
+ return NULL;
+ }
+ if (buffer.readonly) {
+ PyErr_SetString(PyExc_TypeError, "buffer must be writable");
+ PyBuffer_Release(&buffer);
+ return NULL;
+ }
+ if (buffer.len < n) {
+ PyErr_SetString(PyExc_ValueError, "buffer must be at least 'n' bytes");
+ PyBuffer_Release(&buffer);
+ return NULL;
+ }
+ Py_ssize_t res = PyLong_AsNativeBytes(v, buffer.buf, n, (int)endianness);
+ PyBuffer_Release(&buffer);
+ return res >= 0 ? PyLong_FromSsize_t(res) : NULL;
+}
+
+static PyObject *
+pylong_fromnativebytes(PyObject *module, PyObject *args)
+{
+ Py_buffer buffer;
+ Py_ssize_t n, endianness, signed_;
+ if (!PyArg_ParseTuple(args, "y*nnn", &buffer, &n, &endianness, &signed_)) {
+ return NULL;
+ }
+ if (buffer.len < n) {
+ PyErr_SetString(PyExc_ValueError, "buffer must be at least 'n' bytes");
+ PyBuffer_Release(&buffer);
+ return NULL;
+ }
+ PyObject *res = signed_
+ ? PyLong_FromNativeBytes(buffer.buf, n, (int)endianness)
+ : PyLong_FromUnsignedNativeBytes(buffer.buf, n, (int)endianness);
+ PyBuffer_Release(&buffer);
+ return res;
+}
+
+
static PyMethodDef test_methods[] = {
_TESTCAPI_TEST_LONG_AND_OVERFLOW_METHODDEF
_TESTCAPI_TEST_LONG_API_METHODDEF
@@ -804,6 +849,8 @@ static PyMethodDef test_methods[] = {
{"pylong_as_size_t", pylong_as_size_t, METH_O},
{"pylong_asdouble", pylong_asdouble, METH_O},
{"pylong_asvoidptr", pylong_asvoidptr, METH_O},
+ {"pylong_asnativebytes", pylong_asnativebytes, METH_VARARGS},
+ {"pylong_fromnativebytes", pylong_fromnativebytes, METH_VARARGS},
{NULL},
};
@@ -813,6 +860,5 @@ _PyTestCapi_Init_Long(PyObject *mod)
if (PyModule_AddFunctions(mod, test_methods) < 0) {
return -1;
}
-
return 0;
}
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index f618116..e378986 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -926,7 +926,8 @@ AsObj(PyObject *value)
(unsigned char *)(void *)&wideValue,
sizeof(wideValue),
PY_LITTLE_ENDIAN,
- /* signed */ 1) == 0) {
+ /* signed */ 1,
+ /* with_exceptions */ 1) == 0) {
return Tcl_NewWideIntObj(wideValue);
}
PyErr_Clear();
diff --git a/Modules/cjkcodecs/multibytecodec.c b/Modules/cjkcodecs/multibytecodec.c
index 5d3c16a..2125da4 100644
--- a/Modules/cjkcodecs/multibytecodec.c
+++ b/Modules/cjkcodecs/multibytecodec.c
@@ -973,7 +973,8 @@ _multibytecodec_MultibyteIncrementalEncoder_setstate_impl(MultibyteIncrementalEn
if (_PyLong_AsByteArray(statelong, statebytes, sizeof(statebytes),
1 /* little-endian */ ,
- 0 /* unsigned */ ) < 0) {
+ 0 /* unsigned */ ,
+ 1 /* with_exceptions */) < 0) {
goto errorexit;
}
@@ -1255,7 +1256,8 @@ _multibytecodec_MultibyteIncrementalDecoder_setstate_impl(MultibyteIncrementalDe
if (_PyLong_AsByteArray(statelong, statebytes, sizeof(statebytes),
1 /* little-endian */ ,
- 0 /* unsigned */ ) < 0) {
+ 0 /* unsigned */ ,
+ 1 /* with_exceptions */) < 0) {
return NULL;
}
diff --git a/Objects/longobject.c b/Objects/longobject.c
index e655ba1..932111f 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -928,7 +928,8 @@ _PyLong_FromByteArray(const unsigned char* bytes, size_t n,
int
_PyLong_AsByteArray(PyLongObject* v,
unsigned char* bytes, size_t n,
- int little_endian, int is_signed)
+ int little_endian, int is_signed,
+ int with_exceptions)
{
Py_ssize_t i; /* index into v->long_value.ob_digit */
Py_ssize_t ndigits; /* number of digits */
@@ -945,8 +946,10 @@ _PyLong_AsByteArray(PyLongObject* v,
ndigits = _PyLong_DigitCount(v);
if (_PyLong_IsNegative(v)) {
if (!is_signed) {
- PyErr_SetString(PyExc_OverflowError,
- "can't convert negative int to unsigned");
+ if (with_exceptions) {
+ PyErr_SetString(PyExc_OverflowError,
+ "can't convert negative int to unsigned");
+ }
return -1;
}
do_twos_comp = 1;
@@ -967,7 +970,12 @@ _PyLong_AsByteArray(PyLongObject* v,
/* Copy over all the Python digits.
It's crucial that every Python digit except for the MSD contribute
exactly PyLong_SHIFT bits to the total, so first assert that the int is
- normalized. */
+ normalized.
+ NOTE: PyLong_AsNativeBytes() assumes that this function will fill in 'n'
+ bytes even if it eventually fails to convert the whole number. Make sure
+ you account for that if you are changing this algorithm to return without
+ doing that.
+ */
assert(ndigits == 0 || v->long_value.ob_digit[ndigits - 1] != 0);
j = 0;
accum = 0;
@@ -1052,11 +1060,203 @@ _PyLong_AsByteArray(PyLongObject* v,
return 0;
Overflow:
- PyErr_SetString(PyExc_OverflowError, "int too big to convert");
+ if (with_exceptions) {
+ PyErr_SetString(PyExc_OverflowError, "int too big to convert");
+ }
return -1;
}
+// Refactored out for readability, not reuse
+static inline int
+_fits_in_n_bits(Py_ssize_t v, Py_ssize_t n)
+{
+ if (n >= (Py_ssize_t)sizeof(Py_ssize_t) * 8) {
+ return 1;
+ }
+ // If all bits above n are the same, we fit.
+ // (Use n-1 if we require the sign bit to be consistent.)
+ Py_ssize_t v_extended = v >> ((int)n - 1);
+ return v_extended == 0 || v_extended == -1;
+}
+
+static inline int
+_resolve_endianness(int *endianness)
+{
+ if (*endianness < 0) {
+ *endianness = PY_LITTLE_ENDIAN;
+ }
+ if (*endianness != 0 && *endianness != 1) {
+ PyErr_SetString(PyExc_SystemError, "invalid 'endianness' value");
+ return -1;
+ }
+ return 0;
+}
+
+Py_ssize_t
+PyLong_AsNativeBytes(PyObject* vv, void* buffer, Py_ssize_t n, int endianness)
+{
+ PyLongObject *v;
+ union {
+ Py_ssize_t v;
+ unsigned char b[sizeof(Py_ssize_t)];
+ } cv;
+ int do_decref = 0;
+ Py_ssize_t res = 0;
+
+ if (vv == NULL || n < 0) {
+ PyErr_BadInternalCall();
+ return -1;
+ }
+
+ int little_endian = endianness;
+ if (_resolve_endianness(&little_endian) < 0) {
+ return -1;
+ }
+
+ if (PyLong_Check(vv)) {
+ v = (PyLongObject *)vv;
+ }
+ else {
+ v = (PyLongObject *)_PyNumber_Index(vv);
+ if (v == NULL) {
+ return -1;
+ }
+ do_decref = 1;
+ }
+
+ if (_PyLong_IsCompact(v)) {
+ res = 0;
+ cv.v = _PyLong_CompactValue(v);
+ /* Most paths result in res = sizeof(compact value). Only the case
+ * where 0 < n < sizeof(compact value) do we need to check and adjust
+ * our return value. */
+ res = sizeof(cv.b);
+ if (n <= 0) {
+ // nothing to do!
+ }
+ else if (n <= sizeof(cv.b)) {
+#if PY_LITTLE_ENDIAN
+ if (little_endian) {
+ memcpy(buffer, cv.b, n);
+ }
+ else {
+ for (Py_ssize_t i = 0; i < n; ++i) {
+ ((unsigned char*)buffer)[n - i - 1] = cv.b[i];
+ }
+ }
+#else
+ if (little_endian) {
+ for (Py_ssize_t i = 0; i < n; ++i) {
+ ((unsigned char*)buffer)[i] = cv.b[sizeof(cv.b) - i - 1];
+ }
+ }
+ else {
+ memcpy(buffer, &cv.b[sizeof(cv.b) - n], n);
+ }
+#endif
+
+ /* If we fit, return the requested number of bytes */
+ if (_fits_in_n_bits(cv.v, n * 8)) {
+ res = n;
+ }
+ }
+ else {
+ unsigned char fill = cv.v < 0 ? 0xFF : 0x00;
+#if PY_LITTLE_ENDIAN
+ if (little_endian) {
+ memcpy(buffer, cv.b, sizeof(cv.b));
+ memset((char *)buffer + sizeof(cv.b), fill, n - sizeof(cv.b));
+ }
+ else {
+ unsigned char *b = (unsigned char *)buffer;
+ for (Py_ssize_t i = 0; i < n - (int)sizeof(cv.b); ++i) {
+ *b++ = fill;
+ }
+ for (Py_ssize_t i = sizeof(cv.b); i > 0; --i) {
+ *b++ = cv.b[i - 1];
+ }
+ }
+#else
+ if (little_endian) {
+ unsigned char *b = (unsigned char *)buffer;
+ for (Py_ssize_t i = sizeof(cv.b); i > 0; --i) {
+ *b++ = cv.b[i - 1];
+ }
+ for (Py_ssize_t i = 0; i < n - sizeof(cv.b); ++i) {
+ *b++ = fill;
+ }
+ }
+ else {
+ memset(buffer, fill, n - sizeof(cv.b));
+ memcpy((char *)buffer + n - sizeof(cv.b), cv.b, sizeof(cv.b));
+ }
+#endif
+ }
+ }
+ else {
+ if (n > 0) {
+ _PyLong_AsByteArray(v, buffer, (size_t)n, little_endian, 1, 0);
+ }
+
+ // More efficient calculation for number of bytes required?
+ size_t nb = _PyLong_NumBits((PyObject *)v);
+ /* Normally this would be((nb - 1) / 8) + 1 to avoid rounding up
+ * multiples of 8 to the next byte, but we add an implied bit for
+ * the sign and it cancels out. */
+ size_t n_needed = (nb / 8) + 1;
+ res = (Py_ssize_t)n_needed;
+ if ((size_t)res != n_needed) {
+ PyErr_SetString(PyExc_OverflowError,
+ "value too large to convert");
+ res = -1;
+ }
+ }
+
+ if (do_decref) {
+ Py_DECREF(v);
+ }
+
+ return res;
+}
+
+
+PyObject *
+PyLong_FromNativeBytes(const void* buffer, size_t n, int endianness)
+{
+ if (!buffer) {
+ PyErr_BadInternalCall();
+ return NULL;
+ }
+
+ int little_endian = endianness;
+ if (_resolve_endianness(&little_endian) < 0) {
+ return NULL;
+ }
+
+ return _PyLong_FromByteArray((const unsigned char *)buffer, n,
+ little_endian, 1);
+}
+
+
+PyObject *
+PyLong_FromUnsignedNativeBytes(const void* buffer, size_t n, int endianness)
+{
+ if (!buffer) {
+ PyErr_BadInternalCall();
+ return NULL;
+ }
+
+ int little_endian = endianness;
+ if (_resolve_endianness(&little_endian) < 0) {
+ return NULL;
+ }
+
+ return _PyLong_FromByteArray((const unsigned char *)buffer, n,
+ little_endian, 0);
+}
+
+
/* Create a new int object from a C pointer */
PyObject *
@@ -1231,7 +1431,7 @@ PyLong_AsLongLong(PyObject *vv)
}
else {
res = _PyLong_AsByteArray((PyLongObject *)v, (unsigned char *)&bytes,
- SIZEOF_LONG_LONG, PY_LITTLE_ENDIAN, 1);
+ SIZEOF_LONG_LONG, PY_LITTLE_ENDIAN, 1, 1);
}
if (do_decref) {
Py_DECREF(v);
@@ -1270,7 +1470,7 @@ PyLong_AsUnsignedLongLong(PyObject *vv)
}
else {
res = _PyLong_AsByteArray((PyLongObject *)vv, (unsigned char *)&bytes,
- SIZEOF_LONG_LONG, PY_LITTLE_ENDIAN, 0);
+ SIZEOF_LONG_LONG, PY_LITTLE_ENDIAN, 0, 1);
}
/* Plan 9 can't handle long long in ? : expressions */
@@ -6068,7 +6268,7 @@ int_to_bytes_impl(PyObject *self, Py_ssize_t length, PyObject *byteorder,
if (_PyLong_AsByteArray((PyLongObject *)self,
(unsigned char *)PyBytes_AS_STRING(bytes),
- length, little_endian, is_signed) < 0) {
+ length, little_endian, is_signed, 1) < 0) {
Py_DECREF(bytes);
return NULL;
}
generated by cgit v0.12 at 2025-08-10 02:55:42 (GMT)