GH-145247: Implement _PyTuple_FromPair

Include/internal/pycore_tuple.h

@@ -26,6 +26,9 @@ extern PyStatus _PyTuple_InitGlobalObjects(PyInterpreterState *);
 PyAPI_FUNC(PyObject *)_PyTuple_FromStackRefStealOnSuccess(const union _PyStackRef *, Py_ssize_t);
 PyAPI_FUNC(PyObject *)_PyTuple_FromArraySteal(PyObject *const *, Py_ssize_t);
 
+PyAPI_FUNC(PyObject *)_PyTuple_FromPair(PyObject *, PyObject *);
+PyAPI_FUNC(PyObject *)_PyTuple_FromPairSteal(PyObject *, PyObject *);
+
 typedef struct {
     PyObject_HEAD
     Py_ssize_t it_index;

Lib/test/test_capi/test_tuple.py

@@ -1,9 +1,11 @@
 import unittest
 import gc
+from sys import getrefcount
 from test.support import import_helper
 
 _testcapi = import_helper.import_module('_testcapi')
 _testlimitedcapi = import_helper.import_module('_testlimitedcapi')
+_testinternalcapi = import_helper.import_module('_testinternalcapi')
 
 NULL = None
 PY_SSIZE_T_MIN = _testcapi.PY_SSIZE_T_MIN
@@ -118,6 +120,36 @@ def test_tuple_pack(self):
         # CRASHES pack(1, NULL)
         # CRASHES pack(2, [1])
 
+    def test_tuple_from_pair(self):
+        # Test _PyTuple_FromPair, _PyTuple_FromPairSteal
+        ctors = (("_PyTuple_FromPair", _testinternalcapi._tuple_from_pair),
+                 ("_PyTuple_FromPairSteal", _testinternalcapi._tuple_from_pair_steal))
+
+        for name, ctor in ctors:
+            with self.subTest(name):
+                self.assertEqual(ctor(1, 2), (1, 2))
+                self.assertEqual(ctor(None, None), (None, None))
+                self.assertEqual(ctor(True, False), (True, False))
+
+                # user class supports gc
+                class Temp:
+                    pass
+                temp = Temp()
+                temp_rc = getrefcount(temp)
+                self.assertEqual(ctor(temp, temp), (temp, temp))
+                self.assertEqual(getrefcount(temp), temp_rc)
+
+                self.assertRaises(TypeError, ctor, 1, 2, 3)
+                self.assertRaises(TypeError, ctor, 1)
+                self.assertRaises(TypeError, ctor)
+
+                self.assertFalse(gc.is_tracked(ctor(1, 2)))
+                self.assertFalse(gc.is_tracked(ctor(None, None)))
+                self.assertFalse(gc.is_tracked(ctor(True, False)))
+                self.assertTrue(gc.is_tracked(ctor(temp, (1, 2))))
+                self.assertTrue(gc.is_tracked(ctor(temp, 1)))
+                self.assertTrue(gc.is_tracked(ctor([], {})))
+
     def test_tuple_size(self):
         # Test PyTuple_Size()
         size = _testlimitedcapi.tuple_size

Modules/Setup.stdlib.in

@@ -174,7 +174,7 @@
 @MODULE_XXSUBTYPE_TRUE@xxsubtype xxsubtype.c
 @MODULE__XXTESTFUZZ_TRUE@_xxtestfuzz _xxtestfuzz/_xxtestfuzz.c _xxtestfuzz/fuzzer.c
 @MODULE__TESTBUFFER_TRUE@_testbuffer _testbuffer.c
-@MODULE__TESTINTERNALCAPI_TRUE@_testinternalcapi _testinternalcapi.c _testinternalcapi/test_lock.c _testinternalcapi/pytime.c _testinternalcapi/set.c _testinternalcapi/test_critical_sections.c _testinternalcapi/complex.c _testinternalcapi/interpreter.c
+@MODULE__TESTINTERNALCAPI_TRUE@_testinternalcapi _testinternalcapi.c _testinternalcapi/test_lock.c _testinternalcapi/pytime.c _testinternalcapi/set.c _testinternalcapi/test_critical_sections.c _testinternalcapi/complex.c _testinternalcapi/interpreter.c _testinternalcapi/tuple.c
 @MODULE__TESTCAPI_TRUE@_testcapi _testcapimodule.c _testcapi/vectorcall.c _testcapi/heaptype.c _testcapi/abstract.c _testcapi/unicode.c _testcapi/dict.c _testcapi/set.c _testcapi/list.c _testcapi/tuple.c _testcapi/getargs.c _testcapi/datetime.c _testcapi/docstring.c _testcapi/mem.c _testcapi/watchers.c _testcapi/long.c _testcapi/float.c _testcapi/complex.c _testcapi/numbers.c _testcapi/structmember.c _testcapi/exceptions.c _testcapi/code.c _testcapi/buffer.c _testcapi/pyatomic.c _testcapi/run.c _testcapi/file.c _testcapi/codec.c _testcapi/immortal.c _testcapi/gc.c _testcapi/hash.c _testcapi/time.c _testcapi/bytes.c _testcapi/object.c _testcapi/modsupport.c _testcapi/monitoring.c _testcapi/config.c _testcapi/import.c _testcapi/frame.c _testcapi/type.c _testcapi/function.c _testcapi/module.c
 @MODULE__TESTLIMITEDCAPI_TRUE@_testlimitedcapi _testlimitedcapi.c _testlimitedcapi/abstract.c _testlimitedcapi/bytearray.c _testlimitedcapi/bytes.c _testlimitedcapi/codec.c _testlimitedcapi/complex.c _testlimitedcapi/dict.c _testlimitedcapi/eval.c _testlimitedcapi/float.c _testlimitedcapi/heaptype_relative.c _testlimitedcapi/import.c _testlimitedcapi/list.c _testlimitedcapi/long.c _testlimitedcapi/object.c _testlimitedcapi/pyos.c _testlimitedcapi/set.c _testlimitedcapi/sys.c _testlimitedcapi/tuple.c _testlimitedcapi/unicode.c _testlimitedcapi/vectorcall_limited.c _testlimitedcapi/version.c _testlimitedcapi/file.c
 @MODULE__TESTCLINIC_TRUE@_testclinic _testclinic.c

Modules/_testinternalcapi.c

@@ -2981,6 +2981,9 @@ module_exec(PyObject *module)
     if (_PyTestInternalCapi_Init_CriticalSection(module) < 0) {
         return 1;
     }
+    if (_PyTestInternalCapi_Init_Tuple(module) < 0) {
+        return 1;
+    }
 
     Py_ssize_t sizeof_gc_head = 0;
 #ifndef Py_GIL_DISABLED

Modules/_testinternalcapi/parts.h

@@ -15,5 +15,6 @@ int _PyTestInternalCapi_Init_PyTime(PyObject *module);
 int _PyTestInternalCapi_Init_Set(PyObject *module);
 int _PyTestInternalCapi_Init_Complex(PyObject *module);
 int _PyTestInternalCapi_Init_CriticalSection(PyObject *module);
+int _PyTestInternalCapi_Init_Tuple(PyObject *module);
 
 #endif // Py_TESTINTERNALCAPI_PARTS_H

Modules/_testinternalcapi/tuple.c

@@ -0,0 +1,43 @@
+#include "parts.h"
+
+#include "pycore_tuple.h"
+
+
+static PyObject *
+_tuple_from_pair(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    PyObject *one, *two;
+    if (!PyArg_ParseTuple(args, "OO", &one, &two)) {
+        return NULL;
+    }
+
+    return _PyTuple_FromPair(one, two);
+}
+
+static PyObject *
+_tuple_from_pair_steal(PyObject *Py_UNUSED(module), PyObject *args)
+{
+    PyObject *one, *two;
+    if (!PyArg_ParseTuple(args, "OO", &one, &two)) {
+        return NULL;
+    }
+
+    return _PyTuple_FromPairSteal(Py_NewRef(one), Py_NewRef(two));
+}
+
+
+static PyMethodDef test_methods[] = {
+    {"_tuple_from_pair", _tuple_from_pair, METH_VARARGS},
+    {"_tuple_from_pair_steal", _tuple_from_pair_steal, METH_VARARGS},
+    {NULL},
+};
+
+int
+_PyTestInternalCapi_Init_Tuple(PyObject *m)
+{
+    if (PyModule_AddFunctions(m, test_methods) < 0) {
+        return -1;
+    }
+
+    return 0;
+}

Objects/tupleobject.c

@@ -202,6 +202,58 @@ PyTuple_Pack(Py_ssize_t n, ...)
     return (PyObject *)result;
 }
 
+static PyTupleObject *
+tuple_alloc_2(void)
+{
+    Py_ssize_t size = 2;
+    Py_ssize_t index = size - 1;
+    PyTupleObject *result = _Py_FREELIST_POP(PyTupleObject, tuples[index]);
+    if (result == NULL) {
+        result = PyObject_GC_NewVar(PyTupleObject, &PyTuple_Type, size);
+    }
+    if (result != NULL) {
+        _PyTuple_RESET_HASH_CACHE(result);
+    }
+    return result;
+}
+
+PyObject *
+_PyTuple_FromPair(PyObject *one, PyObject *two)
+{
+    assert (one != NULL);
+    assert (two != NULL);
+
+    PyTupleObject *op = tuple_alloc_2();
+    if (op == NULL) {
+        return NULL;
+    }
+    op->ob_item[0] = Py_NewRef(one);
+    op->ob_item[1] = Py_NewRef(two);
+    if (maybe_tracked(one) || maybe_tracked(two)) {
+        _PyObject_GC_TRACK(op);
+    }
+    return (PyObject *)op;
+}
+
+PyObject *
+_PyTuple_FromPairSteal(PyObject *one, PyObject *two)
+{
+    assert (one != NULL);
+    assert (two != NULL);
+
+    PyTupleObject *op = tuple_alloc_2();
+    if (op == NULL) {
+        Py_DECREF(one);
+        Py_DECREF(two);
+        return NULL;
+    }
+    op->ob_item[0] = one;
+    op->ob_item[1] = two;
+    if (maybe_tracked(one) || maybe_tracked(two)) {
+        _PyObject_GC_TRACK(op);
+    }
+    return (PyObject *)op;
+}
 
 /* Methods */
 

PCbuild/_testinternalcapi.vcxproj

@@ -100,6 +100,7 @@
     <ClCompile Include="..\Modules\_testinternalcapi\set.c" />
     <ClCompile Include="..\Modules\_testinternalcapi\complex.c" />
     <ClCompile Include="..\Modules\_testinternalcapi\interpreter.c" />
+    <ClCompile Include="..\Modules\_testinternalcapi\tuple.c" />
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="..\PC\python_nt.rc" />

PCbuild/_testinternalcapi.vcxproj.filters

@@ -27,6 +27,9 @@
     <ClCompile Include="..\Modules\_testinternalcapi\complex.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\Modules\_testinternalcapi\tuple.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="..\PC\python_nt.rc">