Merge branch 'main' into fix-checck-html

Author: StanFromIreland

Doc/c-api/module.rst

@@ -230,6 +230,9 @@ Feature slots
    When creating a module, Python checks the value of this slot
    using :c:func:`PyABIInfo_Check`.
 
+   This slot is required, except for modules created from
+   :c:struct:`PyModuleDef`.
+
    .. versionadded:: 3.15
 
 .. c:macro:: Py_mod_multiple_interpreters
@@ -620,9 +623,9 @@ rather than from an extension's :ref:`export hook <extension-export-hook>`.
    and the :py:class:`~importlib.machinery.ModuleSpec` *spec*.
 
    The *slots* argument must point to an array of :c:type:`PyModuleDef_Slot`
-   structures, terminated by an entry slot with slot ID of 0
+   structures, terminated by an entry with slot ID of 0
    (typically written as ``{0}`` or ``{0, NULL}`` in C).
-   The *slots* argument may not be ``NULL``.
+   The array must include a :c:data:`Py_mod_abi` entry.
 
    The *spec* argument may be any ``ModuleSpec``-like object, as described
    in :c:macro:`Py_mod_create` documentation.

Doc/extending/first-extension-module.rst

@@ -265,12 +265,19 @@ Define this array just before your export hook:
 
 .. code-block:: c
 
+   PyABIInfo_VAR(abi_info);
+
    static PyModuleDef_Slot spam_slots[] = {
+      {Py_mod_abi, &abi_info},
       {Py_mod_name, "spam"},
       {Py_mod_doc, "A wonderful module with an example function"},
       {0, NULL}
    };
 
+The ``PyABIInfo_VAR(abi_info);`` macro and the :c:data:`Py_mod_abi` slot
+are a bit of boilerplate that helps prevent extensions compiled for
+a different version of Python from crashing the interpreter.
+
 For both :c:data:`Py_mod_name` and :c:data:`Py_mod_doc`, the values are C
 strings -- that is, NUL-terminated, UTF-8 encoded byte arrays.
 

Doc/includes/capi-extension/spammodule-01.c

@@ -35,7 +35,10 @@ static PyMethodDef spam_methods[] = {
 
 /// Module slot table
 
+PyABIInfo_VAR(abi_info);
+
 static PyModuleDef_Slot spam_slots[] = {
+    {Py_mod_abi, &abi_info},
     {Py_mod_name, "spam"},
     {Py_mod_doc, "A wonderful module with an example function"},
     {Py_mod_methods, spam_methods},

Doc/library/functions.rst

@@ -1754,7 +1754,7 @@ are always available.  They are listed here in alphabetical order.
             self.age = age
 
          def __repr__(self):
-            return f"Person('{self.name}', {self.age})"
+            return f"Person({self.name!r}, {self.age!r})"
 
 
 .. function:: reversed(object, /)

Doc/whatsnew/3.15.rst

@@ -1347,11 +1347,11 @@ Upgraded JIT compiler
 
 Results from the `pyperformance <https://github.com/python/pyperformance>`__
 benchmark suite report
-`5-6% <https://doesjitgobrrr.com/run/2026-03-11>`__
+`6-7% <https://www.doesjitgobrrr.com/run/2026-04-01>`__
 geometric mean performance improvement for the JIT over the standard CPython
 interpreter built with all optimizations enabled on x86-64 Linux. On AArch64
 macOS, the JIT has a
-`8-9% <https://doesjitgobrrr.com/run/2026-03-11>`__
+`12-13% <https://www.doesjitgobrrr.com/run/2026-04-01>`__
 speedup over the :ref:`tail calling interpreter <whatsnew314-tail-call-interpreter>`
 with all optimizations enabled. The speedups for JIT
 builds versus no JIT builds range from roughly 15% slowdown to over

Include/cpython/longintrepr.h

@@ -133,6 +133,11 @@ _PyLong_CompactValue(const PyLongObject *op)
     assert(PyType_HasFeature(op->ob_base.ob_type, Py_TPFLAGS_LONG_SUBCLASS));
     assert(PyUnstable_Long_IsCompact(op));
     sign = 1 - (op->long_value.lv_tag & _PyLong_SIGN_MASK);
+    if (sign == 0) {
+        // gh-147988: Make sure that the digit is zero.
+        // It helps detecting the usage of uninitialized digits.
+        assert(op->long_value.ob_digit[0] == 0);
+    }
     return sign * (Py_ssize_t)op->long_value.ob_digit[0];
 }
 

Include/internal/pycore_long.h

@@ -238,11 +238,12 @@ _PyLong_IsSmallInt(const PyLongObject *op)
 {
     assert(PyLong_Check(op));
     bool is_small_int = (op->long_value.lv_tag & IMMORTALITY_BIT_MASK) != 0;
-    assert(PyLong_CheckExact(op) || (!is_small_int));
-    assert(_Py_IsImmortal(op) || (!is_small_int));
-    assert((_PyLong_IsCompact(op)
-            && _PY_IS_SMALL_INT(_PyLong_CompactValue(op)))
-           || (!is_small_int));
+    if (is_small_int) {
+        assert(PyLong_CheckExact(op));
+        assert(_Py_IsImmortal(op));
+        assert((_PyLong_IsCompact(op)
+                && _PY_IS_SMALL_INT(_PyLong_CompactValue(op))));
+    }
     return is_small_int;
 }
 
@@ -285,6 +286,14 @@ _PyLong_SameSign(const PyLongObject *a, const PyLongObject *b)
     return (a->long_value.lv_tag & SIGN_MASK) == (b->long_value.lv_tag & SIGN_MASK);
 }
 
+/* Initialize the tag of a freshly-allocated int. */
+static inline void
+_PyLong_InitTag(PyLongObject *op)
+{
+    assert(PyLong_Check(op));
+    op->long_value.lv_tag = SIGN_ZERO; /* non-immortal zero */
+}
+
 #define TAG_FROM_SIGN_AND_SIZE(sign, size) \
     ((uintptr_t)(1 - (sign)) | ((uintptr_t)(size) << NON_SIZE_BITS))
 
@@ -294,13 +303,15 @@ _PyLong_SetSignAndDigitCount(PyLongObject *op, int sign, Py_ssize_t size)
     assert(size >= 0);
     assert(-1 <= sign && sign <= 1);
     assert(sign != 0 || size == 0);
+    assert(!_PyLong_IsSmallInt(op));
     op->long_value.lv_tag = TAG_FROM_SIGN_AND_SIZE(sign, size);
 }
 
 static inline void
 _PyLong_SetDigitCount(PyLongObject *op, Py_ssize_t size)
 {
     assert(size >= 0);
+    assert(!_PyLong_IsSmallInt(op));
     op->long_value.lv_tag = (((size_t)size) << NON_SIZE_BITS) | (op->long_value.lv_tag & SIGN_MASK);
 }
 

Lib/test/support/__init__.py

@@ -71,7 +71,8 @@
     "BrokenIter",
     "in_systemd_nspawn_sync_suppressed",
     "run_no_yield_async_fn", "run_yielding_async_fn", "async_yield",
-    "reset_code", "on_github_actions"
+    "reset_code", "on_github_actions",
+    "requires_root_user", "requires_non_root_user",
     ]
 
 
@@ -3317,3 +3318,8 @@ def control_characters_c0() -> list[str]:
     C0 control characters defined as the byte range 0x00-0x1F, and 0x7F.
     """
     return [chr(c) for c in range(0x00, 0x20)] + ["\x7F"]
+
+
+_ROOT_IN_POSIX = hasattr(os, 'geteuid') and os.geteuid() == 0
+requires_root_user = unittest.skipUnless(_ROOT_IN_POSIX, "test needs root privilege")
+requires_non_root_user = unittest.skipIf(_ROOT_IN_POSIX, "test needs non-root account")

Lib/test/test_capi/test_long.py

@@ -803,6 +803,16 @@ def to_digits(num):
                 self.assertEqual(pylongwriter_create(negative, digits), num,
                                  (negative, digits))
 
+    @unittest.skipUnless(support.Py_DEBUG, "need a debug build (Py_DEBUG)")
+    def test_longwriter_finish(self):
+        # Test PyLongWriter_Create(0, 3, &digits) with PyLongWriter_Finish()
+        # where the last digit is left uninitialized
+        pylongwriter_finish_bug = _testcapi.pylongwriter_finish_bug
+        with self.assertRaises(SystemError) as cm:
+            pylongwriter_finish_bug()
+        self.assertEqual(str(cm.exception),
+                         'PyLongWriter_Finish: digit 2 is uninitialized')
+
     def test_bug_143050(self):
         with support.adjust_int_max_str_digits(0):
             # Bug coming from using _pylong.int_from_string(), that

Lib/test/test_capi/test_module.py

@@ -25,9 +25,13 @@ def def_and_token(mod):
     )
 
 class TestModFromSlotsAndSpec(unittest.TestCase):
-    @requires_gil_enabled("empty slots re-enable GIL")
     def test_empty(self):
-        mod = _testcapi.module_from_slots_empty(FakeSpec())
+        with self.assertRaises(SystemError):
+            _testcapi.module_from_slots_empty(FakeSpec())
+
+    @requires_gil_enabled("minimal slots re-enable GIL")
+    def test_minimal(self):
+        mod = _testcapi.module_from_slots_minimal(FakeSpec())
         self.assertIsInstance(mod, types.ModuleType)
         self.assertEqual(def_and_token(mod), (0, 0))
         self.assertEqual(mod.__name__, 'testmod')
@@ -159,6 +163,16 @@ def test_null_def_slot(self):
                 self.assertIn(name, str(cm.exception))
                 self.assertIn("NULL", str(cm.exception))
 
+    def test_bad_abiinfo(self):
+        """Slots that incompatible ABI is rejected"""
+        with self.assertRaises(ImportError) as cm:
+            _testcapi.module_from_bad_abiinfo(FakeSpec())
+
+    def test_multiple_abiinfo(self):
+        """Slots that Py_mod_abiinfo can be repeated"""
+        mod = _testcapi.module_from_multiple_abiinfo(FakeSpec())
+        self.assertEqual(mod.__name__, 'testmod')
+
     def test_def_multiple_exec(self):
         """PyModule_Exec runs all exec slots of PyModuleDef-defined module"""
         mod = _testcapi.module_from_def_multiple_exec(FakeSpec())