gh-99845: Use size_t type in __sizeof__() methods (#99846)

The implementation of __sizeof__() methods using _PyObject_SIZE() now
use an unsigned type (size_t) to compute the size, rather than a signed
type (Py_ssize_t).

Cast explicitly signed (Py_ssize_t) values to unsigned type
(Py_ssize_t).

3 files changed, 11 insertions, 14 deletions

diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index 0ba6fb5..f24690a 100644
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -2151,10 +2151,9 @@ static PyObject *
 bytearray_sizeof_impl(PyByteArrayObject *self)
 /*[clinic end generated code: output=738abdd17951c427 input=e27320fd98a4bc5a]*/
 {
-    Py_ssize_t res;
-
-    res = _PyObject_SIZE(Py_TYPE(self)) + self->ob_alloc * sizeof(char);
-    return PyLong_FromSsize_t(res);
+    size_t res = _PyObject_SIZE(Py_TYPE(self));
+    res += (size_t)self->ob_alloc * sizeof(char);
+    return PyLong_FromSize_t(res);
 }
 
 static PySequenceMethods bytearray_as_sequence = {
diff --git a/Objects/listobject.c b/Objects/listobject.c
index da623c9..0e696fb 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -2806,10 +2806,9 @@ static PyObject *
 list___sizeof___impl(PyListObject *self)
 /*[clinic end generated code: output=3417541f95f9a53e input=b8030a5d5ce8a187]*/
 {
-    Py_ssize_t res;
-
-    res = _PyObject_SIZE(Py_TYPE(self)) + self->allocated * sizeof(void*);
-    return PyLong_FromSsize_t(res);
+    size_t res = _PyObject_SIZE(Py_TYPE(self));
+    res += (size_t)self->allocated * sizeof(void*);
+    return PyLong_FromSize_t(res);
 }
 
 static PyObject *list_iter(PyObject *seq);
diff --git a/Objects/setobject.c b/Objects/setobject.c
index ae9e9b9..fcdda2a 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -1957,12 +1957,11 @@ done:
 static PyObject *
 set_sizeof(PySetObject *so, PyObject *Py_UNUSED(ignored))
 {
-    Py_ssize_t res;
-
-    res = _PyObject_SIZE(Py_TYPE(so));
-    if (so->table != so->smalltable)
-        res = res + (so->mask + 1) * sizeof(setentry);
-    return PyLong_FromSsize_t(res);
+    size_t res = _PyObject_SIZE(Py_TYPE(so));
+    if (so->table != so->smalltable) {
+        res += ((size_t)so->mask + 1) * sizeof(setentry);
+    }
+    return PyLong_FromSize_t(res);
 }
 
 PyDoc_STRVAR(sizeof_doc, "S.__sizeof__() -> size of S in memory, in bytes");