From 37bc5562403d626ff74b16dbcb0aafcccb507039 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 20 Jan 2025 16:20:32 +0100
Subject: [PATCH 01/16] fix UBSan failures for `buffered`

---
 Modules/_io/bufferedio.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index bc5fff54a62b6d..0877dac696d87f 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -260,6 +260,7 @@ typedef struct {
     PyObject *dict;
     PyObject *weakreflist;
 } buffered;
+#define _buffered_CAST(op)  ((buffered *)(op))
 
 /*
     Implementation notes:
@@ -399,8 +400,9 @@ _enter_buffered_busy(buffered *self)
 
 
 static int
-buffered_clear(buffered *self)
+buffered_clear(PyObject *op)
 {
+    buffered *self = _buffered_CAST(op);
     self->ok = 0;
     Py_CLEAR(self->raw);
     Py_CLEAR(self->dict);
@@ -408,16 +410,17 @@ buffered_clear(buffered *self)
 }
 
 static void
-buffered_dealloc(buffered *self)
+buffered_dealloc(PyObject *op)
 {
+    buffered *self = _buffered_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     self->finalizing = 1;
-    if (_PyIOBase_finalize((PyObject *) self) < 0)
+    if (_PyIOBase_finalize(op) < 0)
         return;
     _PyObject_GC_UNTRACK(self);
     self->ok = 0;
     if (self->weakreflist != NULL)
-        PyObject_ClearWeakRefs((PyObject *)self);
+        PyObject_ClearWeakRefs(op);
     if (self->buffer) {
         PyMem_Free(self->buffer);
         self->buffer = NULL;
@@ -426,8 +429,8 @@ buffered_dealloc(buffered *self)
         PyThread_free_lock(self->lock);
         self->lock = NULL;
     }
-    (void)buffered_clear(self);
-    tp->tp_free((PyObject *)self);
+    (void)buffered_clear(op);
+    tp->tp_free(op);
     Py_DECREF(tp);
 }
 

From 36f5adc10d218540cc3c24dd97cee9562af13cb2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 20 Jan 2025 16:23:35 +0100
Subject: [PATCH 02/16] fix UBSan failures for `rwpair`

---
 Modules/_io/bufferedio.c | 76 ++++++++++++++++++++++++----------------
 1 file changed, 46 insertions(+), 30 deletions(-)

diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index 0877dac696d87f..10531cbab00b02 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -2229,6 +2229,7 @@ typedef struct {
     PyObject *dict;
     PyObject *weakreflist;
 } rwpair;
+#define _rwpair_CAST(op)    ((rwpair *)(op))
 
 /*[clinic input]
 _io.BufferedRWPair.__init__
@@ -2279,8 +2280,9 @@ _io_BufferedRWPair___init___impl(rwpair *self, PyObject *reader,
 }
 
 static int
-bufferedrwpair_traverse(rwpair *self, visitproc visit, void *arg)
+bufferedrwpair_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    rwpair *self = _rwpair_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->dict);
     Py_VISIT(self->reader);
@@ -2289,8 +2291,9 @@ bufferedrwpair_traverse(rwpair *self, visitproc visit, void *arg)
 }
 
 static int
-bufferedrwpair_clear(rwpair *self)
+bufferedrwpair_clear(PyObject *op)
 {
+    rwpair *self = _rwpair_CAST(op);
     Py_CLEAR(self->reader);
     Py_CLEAR(self->writer);
     Py_CLEAR(self->dict);
@@ -2298,14 +2301,15 @@ bufferedrwpair_clear(rwpair *self)
 }
 
 static void
-bufferedrwpair_dealloc(rwpair *self)
+bufferedrwpair_dealloc(PyObject *op)
 {
+    rwpair *self = _rwpair_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     _PyObject_GC_UNTRACK(self);
     if (self->weakreflist != NULL)
-        PyObject_ClearWeakRefs((PyObject *)self);
-    (void)bufferedrwpair_clear(self);
-    tp->tp_free((PyObject *) self);
+        PyObject_ClearWeakRefs(op);
+    (void)bufferedrwpair_clear(op);
+    tp->tp_free(self);
     Py_DECREF(tp);
 }
 
@@ -2331,62 +2335,72 @@ _forward_call(buffered *self, PyObject *name, PyObject *args)
 }
 
 static PyObject *
-bufferedrwpair_read(rwpair *self, PyObject *args)
+bufferedrwpair_read(PyObject *op, PyObject *args)
 {
+    rwpair *self = _rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(read), args);
 }
 
 static PyObject *
-bufferedrwpair_peek(rwpair *self, PyObject *args)
+bufferedrwpair_peek(PyObject *op, PyObject *args)
 {
+    rwpair *self = _rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(peek), args);
 }
 
 static PyObject *
-bufferedrwpair_read1(rwpair *self, PyObject *args)
+bufferedrwpair_read1(PyObject *op, PyObject *args)
 {
+    rwpair *self = _rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(read1), args);
 }
 
 static PyObject *
-bufferedrwpair_readinto(rwpair *self, PyObject *args)
+bufferedrwpair_readinto(PyObject *op, PyObject *args)
 {
+    rwpair *self = _rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(readinto), args);
 }
 
 static PyObject *
-bufferedrwpair_readinto1(rwpair *self, PyObject *args)
+bufferedrwpair_readinto1(PyObject *op, PyObject *args)
 {
+    rwpair *self = _rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(readinto1), args);
 }
 
 static PyObject *
-bufferedrwpair_write(rwpair *self, PyObject *args)
+bufferedrwpair_write(PyObject *op, PyObject *args)
 {
+    rwpair *self = _rwpair_CAST(op);
     return _forward_call(self->writer, &_Py_ID(write), args);
 }
 
 static PyObject *
-bufferedrwpair_flush(rwpair *self, PyObject *Py_UNUSED(ignored))
+bufferedrwpair_flush(PyObject *op, PyObject *Py_UNUSED(ignored))
 {
+    rwpair *self = _rwpair_CAST(op);
     return _forward_call(self->writer, &_Py_ID(flush), NULL);
 }
 
 static PyObject *
-bufferedrwpair_readable(rwpair *self, PyObject *Py_UNUSED(ignored))
+bufferedrwpair_readable(PyObject *op, PyObject *Py_UNUSED(ignored))
 {
+    rwpair *self = _rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(readable), NULL);
 }
 
 static PyObject *
-bufferedrwpair_writable(rwpair *self, PyObject *Py_UNUSED(ignored))
+bufferedrwpair_writable(PyObject *op, PyObject *Py_UNUSED(ignored))
 {
+    rwpair *self = _rwpair_CAST(op);
     return _forward_call(self->writer, &_Py_ID(writable), NULL);
 }
 
 static PyObject *
-bufferedrwpair_close(rwpair *self, PyObject *Py_UNUSED(ignored))
+bufferedrwpair_close(PyObject *op, PyObject *Py_UNUSED(ignored))
 {
+    rwpair *self = _rwpair_CAST(op);
     PyObject *exc = NULL;
     PyObject *ret = _forward_call(self->writer, &_Py_ID(close), NULL);
     if (ret == NULL) {
@@ -2404,8 +2418,9 @@ bufferedrwpair_close(rwpair *self, PyObject *Py_UNUSED(ignored))
 }
 
 static PyObject *
-bufferedrwpair_isatty(rwpair *self, PyObject *Py_UNUSED(ignored))
+bufferedrwpair_isatty(PyObject *op, PyObject *Py_UNUSED(ignored))
 {
+    rwpair *self = _rwpair_CAST(op);
     PyObject *ret = _forward_call(self->writer, &_Py_ID(isatty), NULL);
 
     if (ret != Py_False) {
@@ -2418,8 +2433,9 @@ bufferedrwpair_isatty(rwpair *self, PyObject *Py_UNUSED(ignored))
 }
 
 static PyObject *
-bufferedrwpair_closed_get(rwpair *self, void *context)
+bufferedrwpair_closed_get(PyObject *op, void *Py_UNUSED(context))
 {
+    rwpair *self = _rwpair_CAST(op);
     if (self->writer == NULL) {
         PyErr_SetString(PyExc_RuntimeError,
                 "the BufferedRWPair object is being garbage-collected");
@@ -2636,20 +2652,20 @@ PyType_Spec bufferedwriter_spec = {
 };
 
 static PyMethodDef bufferedrwpair_methods[] = {
-    {"read", (PyCFunction)bufferedrwpair_read, METH_VARARGS},
-    {"peek", (PyCFunction)bufferedrwpair_peek, METH_VARARGS},
-    {"read1", (PyCFunction)bufferedrwpair_read1, METH_VARARGS},
-    {"readinto", (PyCFunction)bufferedrwpair_readinto, METH_VARARGS},
-    {"readinto1", (PyCFunction)bufferedrwpair_readinto1, METH_VARARGS},
+    {"read", bufferedrwpair_read, METH_VARARGS},
+    {"peek", bufferedrwpair_peek, METH_VARARGS},
+    {"read1", bufferedrwpair_read1, METH_VARARGS},
+    {"readinto", bufferedrwpair_readinto, METH_VARARGS},
+    {"readinto1", bufferedrwpair_readinto1, METH_VARARGS},
 
-    {"write", (PyCFunction)bufferedrwpair_write, METH_VARARGS},
-    {"flush", (PyCFunction)bufferedrwpair_flush, METH_NOARGS},
+    {"write", bufferedrwpair_write, METH_VARARGS},
+    {"flush", bufferedrwpair_flush, METH_NOARGS},
 
-    {"readable", (PyCFunction)bufferedrwpair_readable, METH_NOARGS},
-    {"writable", (PyCFunction)bufferedrwpair_writable, METH_NOARGS},
+    {"readable", bufferedrwpair_readable, METH_NOARGS},
+    {"writable", bufferedrwpair_writable, METH_NOARGS},
 
-    {"close", (PyCFunction)bufferedrwpair_close, METH_NOARGS},
-    {"isatty", (PyCFunction)bufferedrwpair_isatty, METH_NOARGS},
+    {"close", bufferedrwpair_close, METH_NOARGS},
+    {"isatty", bufferedrwpair_isatty, METH_NOARGS},
 
     {NULL, NULL}
 };
@@ -2661,7 +2677,7 @@ static PyMemberDef bufferedrwpair_members[] = {
 };
 
 static PyGetSetDef bufferedrwpair_getset[] = {
-    {"closed", (getter)bufferedrwpair_closed_get, NULL, NULL},
+    {"closed", bufferedrwpair_closed_get, NULL, NULL},
     {NULL}
 };
 

From 2a0229327f0189224f5a2cf4195cea5447a8d8fb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 20 Jan 2025 16:50:45 +0100
Subject: [PATCH 03/16] fix UBSan failures for `bytesio`

---
 Modules/_io/bytesio.c | 38 ++++++++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 14 deletions(-)

diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c
index 16095333db6638..be0a64ed2a214d 100644
--- a/Modules/_io/bytesio.c
+++ b/Modules/_io/bytesio.c
@@ -21,6 +21,8 @@ typedef struct {
     Py_ssize_t exports;
 } bytesio;
 
+#define _bytesio_CAST(op)   ((bytesio *)(op))
+
 typedef struct {
     PyObject_HEAD
     bytesio *source;
@@ -239,8 +241,9 @@ write_bytes(bytesio *self, PyObject *b)
 }
 
 static PyObject *
-bytesio_get_closed(bytesio *self, void *Py_UNUSED(ignored))
+bytesio_get_closed(PyObject *op, void *Py_UNUSED(ignored))
 {
+    bytesio *self = _bytesio_CAST(op);
     if (self->buf == NULL) {
         Py_RETURN_TRUE;
     }
@@ -620,9 +623,10 @@ _io_BytesIO_truncate_impl(bytesio *self, Py_ssize_t size)
 }
 
 static PyObject *
-bytesio_iternext(bytesio *self)
+bytesio_iternext(PyObject *op)
 {
     Py_ssize_t n;
+    bytesio *self = _bytesio_CAST(op);
 
     CHECK_CLOSED(self);
 
@@ -783,8 +787,9 @@ _io_BytesIO_close_impl(bytesio *self)
  */
 
 static PyObject *
-bytesio_getstate(bytesio *self, PyObject *Py_UNUSED(ignored))
+bytesio_getstate(PyObject *op, PyObject *Py_UNUSED(ignored))
 {
+    bytesio *self = _bytesio_CAST(op);
     PyObject *initvalue = _io_BytesIO_getvalue_impl(self);
     PyObject *dict;
     PyObject *state;
@@ -808,12 +813,13 @@ bytesio_getstate(bytesio *self, PyObject *Py_UNUSED(ignored))
 }
 
 static PyObject *
-bytesio_setstate(bytesio *self, PyObject *state)
+bytesio_setstate(PyObject *op, PyObject *state)
 {
     PyObject *result;
     PyObject *position_obj;
     PyObject *dict;
     Py_ssize_t pos;
+    bytesio *self = _bytesio_CAST(op);
 
     assert(state != NULL);
 
@@ -883,10 +889,11 @@ bytesio_setstate(bytesio *self, PyObject *state)
 }
 
 static void
-bytesio_dealloc(bytesio *self)
+bytesio_dealloc(PyObject *op)
 {
+    bytesio *self = _bytesio_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
-    _PyObject_GC_UNTRACK(self);
+    _PyObject_GC_UNTRACK(op);
     if (self->exports > 0) {
         PyErr_SetString(PyExc_SystemError,
                         "deallocated BytesIO object has exported buffers");
@@ -895,7 +902,7 @@ bytesio_dealloc(bytesio *self)
     Py_CLEAR(self->buf);
     Py_CLEAR(self->dict);
     if (self->weakreflist != NULL)
-        PyObject_ClearWeakRefs((PyObject *) self);
+        PyObject_ClearWeakRefs(op);
     tp->tp_free(self);
     Py_DECREF(tp);
 }
@@ -961,8 +968,9 @@ _io_BytesIO___init___impl(bytesio *self, PyObject *initvalue)
 }
 
 static PyObject *
-bytesio_sizeof(bytesio *self, void *unused)
+bytesio_sizeof(PyObject *op, PyObject *Py_UNUSED(args))
 {
+    bytesio *self = _bytesio_CAST(op);
     size_t res = _PyObject_SIZE(Py_TYPE(self));
     if (self->buf && !SHARED_BUF(self)) {
         size_t s = _PySys_GetSizeOf(self->buf);
@@ -975,8 +983,9 @@ bytesio_sizeof(bytesio *self, void *unused)
 }
 
 static int
-bytesio_traverse(bytesio *self, visitproc visit, void *arg)
+bytesio_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    bytesio *self = _bytesio_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->dict);
     Py_VISIT(self->buf);
@@ -984,8 +993,9 @@ bytesio_traverse(bytesio *self, visitproc visit, void *arg)
 }
 
 static int
-bytesio_clear(bytesio *self)
+bytesio_clear(PyObject *op)
 {
+    bytesio *self = _bytesio_CAST(op);
     Py_CLEAR(self->dict);
     if (self->exports == 0) {
         Py_CLEAR(self->buf);
@@ -999,7 +1009,7 @@ bytesio_clear(bytesio *self)
 #undef clinic_state
 
 static PyGetSetDef bytesio_getsetlist[] = {
-    {"closed",  (getter)bytesio_get_closed, NULL,
+    {"closed",  bytesio_get_closed, NULL,
      "True if the file is closed."},
     {NULL},            /* sentinel */
 };
@@ -1023,9 +1033,9 @@ static struct PyMethodDef bytesio_methods[] = {
     _IO_BYTESIO_GETVALUE_METHODDEF
     _IO_BYTESIO_SEEK_METHODDEF
     _IO_BYTESIO_TRUNCATE_METHODDEF
-    {"__getstate__",  (PyCFunction)bytesio_getstate,  METH_NOARGS, NULL},
-    {"__setstate__",  (PyCFunction)bytesio_setstate,  METH_O, NULL},
-    {"__sizeof__", (PyCFunction)bytesio_sizeof,     METH_NOARGS, NULL},
+    {"__getstate__",  bytesio_getstate,  METH_NOARGS, NULL},
+    {"__setstate__",  bytesio_setstate,  METH_O, NULL},
+    {"__sizeof__", bytesio_sizeof,     METH_NOARGS, NULL},
     {NULL, NULL}        /* sentinel */
 };
 

From fc3cd12689a19ef793a42eadc0706f3f24802989 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 20 Jan 2025 16:53:03 +0100
Subject: [PATCH 04/16] fix UBSan failures for `bytesiobuf`

---
 Modules/_io/bytesio.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c
index be0a64ed2a214d..0fd3cc96e4a85d 100644
--- a/Modules/_io/bytesio.c
+++ b/Modules/_io/bytesio.c
@@ -28,6 +28,8 @@ typedef struct {
     bytesio *source;
 } bytesiobuf;
 
+#define _bytesiobuf_CAST(op)    ((bytesiobuf *)(op))
+
 /* The bytesio object can be in three states:
   * Py_REFCNT(buf) == 1, exports == 0.
   * Py_REFCNT(buf) > 1.  exports == 0,
@@ -1075,9 +1077,10 @@ PyType_Spec bytesio_spec = {
  */
 
 static int
-bytesiobuf_getbuffer(bytesiobuf *obj, Py_buffer *view, int flags)
+bytesiobuf_getbuffer(PyObject *op, Py_buffer *view, int flags)
 {
-    bytesio *b = (bytesio *) obj->source;
+    bytesiobuf *obj = _bytesiobuf_CAST(op);
+    bytesio *b = _bytesio_CAST(obj->source);
 
     if (view == NULL) {
         PyErr_SetString(PyExc_BufferError,
@@ -1090,7 +1093,7 @@ bytesiobuf_getbuffer(bytesiobuf *obj, Py_buffer *view, int flags)
     }
 
     /* cannot fail if view != NULL and readonly == 0 */
-    (void)PyBuffer_FillInfo(view, (PyObject*)obj,
+    (void)PyBuffer_FillInfo(view, op,
                             PyBytes_AS_STRING(b->buf), b->string_size,
                             0, flags);
     b->exports++;
@@ -1098,26 +1101,29 @@ bytesiobuf_getbuffer(bytesiobuf *obj, Py_buffer *view, int flags)
 }
 
 static void
-bytesiobuf_releasebuffer(bytesiobuf *obj, Py_buffer *view)
+bytesiobuf_releasebuffer(PyObject *op, Py_buffer *Py_UNUSED(view))
 {
-    bytesio *b = (bytesio *) obj->source;
+    bytesiobuf *obj = _bytesiobuf_CAST(op);
+    bytesio *b = _bytesio_CAST(obj->source);
     b->exports--;
 }
 
 static int
-bytesiobuf_traverse(bytesiobuf *self, visitproc visit, void *arg)
+bytesiobuf_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    bytesiobuf *self = _bytesiobuf_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->source);
     return 0;
 }
 
 static void
-bytesiobuf_dealloc(bytesiobuf *self)
+bytesiobuf_dealloc(PyObject *op)
 {
+    bytesiobuf *self = _bytesiobuf_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     /* bpo-31095: UnTrack is needed before calling any callbacks */
-    PyObject_GC_UnTrack(self);
+    PyObject_GC_UnTrack(op);
     Py_CLEAR(self->source);
     tp->tp_free(self);
     Py_DECREF(tp);

From cd728f5e2ecb3ea3ada4151f7923e7f67ba0dff4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 20 Jan 2025 16:58:33 +0100
Subject: [PATCH 05/16] fix UBSan failures for `iobase`

---
 Modules/_io/iobase.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index 419e5516b5c11e..23ea8357ef9ad0 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -34,6 +34,7 @@ typedef struct {
     PyObject *dict;
     PyObject *weakreflist;
 } iobase;
+#define _iobase_CAST(op)    ((iobase *)(op))
 
 PyDoc_STRVAR(iobase_doc,
     "The abstract base class for all I/O classes.\n"
@@ -342,16 +343,18 @@ _PyIOBase_finalize(PyObject *self)
 }
 
 static int
-iobase_traverse(iobase *self, visitproc visit, void *arg)
+iobase_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    iobase *self = _iobase_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->dict);
     return 0;
 }
 
 static int
-iobase_clear(iobase *self)
+iobase_clear(PyObject *op)
 {
+    iobase *self = _iobase_CAST(op);
     Py_CLEAR(self->dict);
     return 0;
 }
@@ -359,14 +362,15 @@ iobase_clear(iobase *self)
 /* Destructor */
 
 static void
-iobase_dealloc(iobase *self)
+iobase_dealloc(PyObject *self)
 {
     /* NOTE: since IOBaseObject has its own dict, Python-defined attributes
        are still available here for close() to use.
        However, if the derived class declares a __slots__, those slots are
        already gone.
     */
-    if (_PyIOBase_finalize((PyObject *) self) < 0) {
+    iobase *base = _iobase_CAST(self);
+    if (_PyIOBase_finalize(self) < 0) {
         /* When called from a heap type's dealloc, the type will be
            decref'ed on return (see e.g. subtype_dealloc in typeobject.c). */
         if (_PyType_HasFeature(Py_TYPE(self), Py_TPFLAGS_HEAPTYPE)) {
@@ -376,10 +380,10 @@ iobase_dealloc(iobase *self)
     }
     PyTypeObject *tp = Py_TYPE(self);
     _PyObject_GC_UNTRACK(self);
-    if (self->weakreflist != NULL)
-        PyObject_ClearWeakRefs((PyObject *) self);
-    Py_CLEAR(self->dict);
-    tp->tp_free((PyObject *)self);
+    if (base->weakreflist != NULL)
+        PyObject_ClearWeakRefs(self);
+    Py_CLEAR(base->dict);
+    tp->tp_free(self);
     Py_DECREF(tp);
 }
 
@@ -852,7 +856,7 @@ static PyMethodDef iobase_methods[] = {
 
 static PyGetSetDef iobase_getset[] = {
     {"__dict__", PyObject_GenericGetDict, NULL, NULL},
-    {"closed", (getter)iobase_closed_get, NULL, NULL},
+    {"closed", iobase_closed_get, NULL, NULL},
     {NULL}
 };
 

From 0da5a8122cc892fd897e0da97bd708528d534309 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 20 Jan 2025 17:00:59 +0100
Subject: [PATCH 06/16] fix UBSan failures for `stringio`

---
 Modules/_io/stringio.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/Modules/_io/stringio.c b/Modules/_io/stringio.c
index 687f584ee6caff..f87acd0bd2d87b 100644
--- a/Modules/_io/stringio.c
+++ b/Modules/_io/stringio.c
@@ -45,6 +45,8 @@ typedef struct {
     _PyIO_State *module_state;
 } stringio;
 
+#define _stringio_CAST(op)  ((stringio *)(op))
+
 #define clinic_state() (find_io_state_by_def(Py_TYPE(self)))
 #include "clinic/stringio.c.h"
 #undef clinic_state
@@ -397,9 +399,10 @@ _io_StringIO_readline_impl(stringio *self, Py_ssize_t size)
 }
 
 static PyObject *
-stringio_iternext(stringio *self)
+stringio_iternext(PyObject *op)
 {
     PyObject *line;
+    stringio *self = _stringio_CAST(op);
 
     CHECK_INITIALIZED(self);
     CHECK_CLOSED(self);
@@ -411,8 +414,7 @@ stringio_iternext(stringio *self)
     }
     else {
         /* XXX is subclassing StringIO really supported? */
-        line = PyObject_CallMethodNoArgs((PyObject *)self,
-                                             &_Py_ID(readline));
+        line = PyObject_CallMethodNoArgs(op, &_Py_ID(readline));
         if (line && !PyUnicode_Check(line)) {
             PyErr_Format(PyExc_OSError,
                          "readline() should have returned a str object, "
@@ -585,8 +587,9 @@ _io_StringIO_close_impl(stringio *self)
 }
 
 static int
-stringio_traverse(stringio *self, visitproc visit, void *arg)
+stringio_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    stringio *self = _stringio_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->readnl);
     Py_VISIT(self->writenl);
@@ -596,8 +599,9 @@ stringio_traverse(stringio *self, visitproc visit, void *arg)
 }
 
 static int
-stringio_clear(stringio *self)
+stringio_clear(PyObject *op)
 {
+    stringio *self = _stringio_CAST(op);
     Py_CLEAR(self->readnl);
     Py_CLEAR(self->writenl);
     Py_CLEAR(self->decoder);
@@ -606,8 +610,9 @@ stringio_clear(stringio *self)
 }
 
 static void
-stringio_dealloc(stringio *self)
+stringio_dealloc(PyObject *op)
 {
+    stringio *self = _stringio_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     _PyObject_GC_UNTRACK(self);
     self->ok = 0;
@@ -616,9 +621,9 @@ stringio_dealloc(stringio *self)
         self->buf = NULL;
     }
     _PyUnicodeWriter_Dealloc(&self->writer);
-    (void)stringio_clear(self);
+    (void)stringio_clear(op);
     if (self->weakreflist != NULL) {
-        PyObject_ClearWeakRefs((PyObject *) self);
+        PyObject_ClearWeakRefs(op);
     }
     tp->tp_free(self);
     Py_DECREF(tp);

From 9889af87da581969bd081e5cf265346eb33256b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 20 Jan 2025 17:04:36 +0100
Subject: [PATCH 07/16] fix UBSan failures for `nldecoder_object`

---
 Modules/_io/textio.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index 791ee070401fe5..7fb20f773c003b 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -222,6 +222,7 @@ struct nldecoder_object {
     unsigned int translate: 1;
     unsigned int seennl: 3;
 };
+#define _nldecoder_object_CAST(op)  ((nldecoder_object *)(op))
 
 /*[clinic input]
 _io.IncrementalNewlineDecoder.__init__
@@ -263,9 +264,9 @@ _io_IncrementalNewlineDecoder___init___impl(nldecoder_object *self,
 }
 
 static int
-incrementalnewlinedecoder_traverse(nldecoder_object *self, visitproc visit,
-                                   void *arg)
+incrementalnewlinedecoder_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    nldecoder_object *self = _nldecoder_object_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->decoder);
     Py_VISIT(self->errors);
@@ -273,20 +274,22 @@ incrementalnewlinedecoder_traverse(nldecoder_object *self, visitproc visit,
 }
 
 static int
-incrementalnewlinedecoder_clear(nldecoder_object *self)
+incrementalnewlinedecoder_clear(PyObject *op)
 {
+    nldecoder_object *self = _nldecoder_object_CAST(op);
     Py_CLEAR(self->decoder);
     Py_CLEAR(self->errors);
     return 0;
 }
 
 static void
-incrementalnewlinedecoder_dealloc(nldecoder_object *self)
+incrementalnewlinedecoder_dealloc(PyObject *op)
 {
+    nldecoder_object *self = _nldecoder_object_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     _PyObject_GC_UNTRACK(self);
-    (void)incrementalnewlinedecoder_clear(self);
-    tp->tp_free((PyObject *)self);
+    (void)incrementalnewlinedecoder_clear(op);
+    tp->tp_free(self);
     Py_DECREF(tp);
 }
 
@@ -323,7 +326,7 @@ _PyIncrementalNewlineDecoder_decode(PyObject *myself,
 {
     PyObject *output;
     Py_ssize_t output_len;
-    nldecoder_object *self = (nldecoder_object *) myself;
+    nldecoder_object *self = _nldecoder_object_CAST(myself);
 
     CHECK_INITIALIZED_DECODER(self);
 
@@ -625,8 +628,9 @@ _io_IncrementalNewlineDecoder_reset_impl(nldecoder_object *self)
 }
 
 static PyObject *
-incrementalnewlinedecoder_newlines_get(nldecoder_object *self, void *context)
+incrementalnewlinedecoder_newlines_get(PyObject *op, void *Py_UNUSED(context))
 {
+    nldecoder_object *self = _nldecoder_object_CAST(op);
     CHECK_INITIALIZED_DECODER(self);
 
     switch (self->seennl) {
@@ -3313,7 +3317,7 @@ static PyMethodDef incrementalnewlinedecoder_methods[] = {
 };
 
 static PyGetSetDef incrementalnewlinedecoder_getset[] = {
-    {"newlines", (getter)incrementalnewlinedecoder_newlines_get, NULL, NULL},
+    {"newlines", incrementalnewlinedecoder_newlines_get, NULL, NULL},
     {NULL}
 };
 

From 19ed68d7be319569e567fa0382974d1f2ea314d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 20 Jan 2025 17:13:12 +0100
Subject: [PATCH 08/16] fix UBSan failures for `textio`

---
 Modules/_io/textio.c | 115 ++++++++++++++++++++++---------------------
 1 file changed, 60 insertions(+), 55 deletions(-)

diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index 7fb20f773c003b..dca22d013b751f 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -656,8 +656,7 @@ incrementalnewlinedecoder_newlines_get(PyObject *op, void *Py_UNUSED(context))
 
 /* TextIOWrapper */
 
-typedef PyObject *
-        (*encodefunc_t)(PyObject *, PyObject *);
+typedef PyObject *(*encodefunc_t)(PyObject *, PyObject *);
 
 struct textio
 {
@@ -719,6 +718,7 @@ struct textio
 
     _PyIO_State *state;
 };
+#define _textio_CAST(op)    ((textio *)(op))
 
 static void
 textiowrapper_set_decoded_chars(textio *self, PyObject *chars);
@@ -727,78 +727,81 @@ textiowrapper_set_decoded_chars(textio *self, PyObject *chars);
    encoding methods for the most popular encodings. */
 
 static PyObject *
-ascii_encode(textio *self, PyObject *text)
+ascii_encode(PyObject *op, PyObject *text)
 {
+    textio *self = _textio_CAST(op);
     return _PyUnicode_AsASCIIString(text, PyUnicode_AsUTF8(self->errors));
 }
 
 static PyObject *
-utf16be_encode(textio *self, PyObject *text)
+utf16be_encode(PyObject *op, PyObject *text)
 {
-    return _PyUnicode_EncodeUTF16(text,
-                                  PyUnicode_AsUTF8(self->errors), 1);
+    textio *self = _textio_CAST(op);
+    return _PyUnicode_EncodeUTF16(text, PyUnicode_AsUTF8(self->errors), 1);
 }
 
 static PyObject *
-utf16le_encode(textio *self, PyObject *text)
+utf16le_encode(PyObject *op, PyObject *text)
 {
-    return _PyUnicode_EncodeUTF16(text,
-                                  PyUnicode_AsUTF8(self->errors), -1);
+    textio *self = _textio_CAST(op);
+    return _PyUnicode_EncodeUTF16(text, PyUnicode_AsUTF8(self->errors), -1);
 }
 
 static PyObject *
-utf16_encode(textio *self, PyObject *text)
+utf16_encode(PyObject *op, PyObject *text)
 {
+    textio *self = _textio_CAST(op);
     if (!self->encoding_start_of_stream) {
         /* Skip the BOM and use native byte ordering */
 #if PY_BIG_ENDIAN
-        return utf16be_encode(self, text);
+        return utf16be_encode(op, text);
 #else
-        return utf16le_encode(self, text);
+        return utf16le_encode(op, text);
 #endif
     }
-    return _PyUnicode_EncodeUTF16(text,
-                                  PyUnicode_AsUTF8(self->errors), 0);
+    return _PyUnicode_EncodeUTF16(text, PyUnicode_AsUTF8(self->errors), 0);
 }
 
 static PyObject *
-utf32be_encode(textio *self, PyObject *text)
+utf32be_encode(PyObject *op, PyObject *text)
 {
-    return _PyUnicode_EncodeUTF32(text,
-                                  PyUnicode_AsUTF8(self->errors), 1);
+    textio *self = _textio_CAST(op);
+    return _PyUnicode_EncodeUTF32(text, PyUnicode_AsUTF8(self->errors), 1);
 }
 
 static PyObject *
-utf32le_encode(textio *self, PyObject *text)
+utf32le_encode(PyObject *op, PyObject *text)
 {
-    return _PyUnicode_EncodeUTF32(text,
-                                  PyUnicode_AsUTF8(self->errors), -1);
+    textio *self = _textio_CAST(op);
+    return _PyUnicode_EncodeUTF32(text, PyUnicode_AsUTF8(self->errors), -1);
 }
 
 static PyObject *
-utf32_encode(textio *self, PyObject *text)
+utf32_encode(PyObject *op, PyObject *text)
 {
+    textio *self = _textio_CAST(op);
     if (!self->encoding_start_of_stream) {
         /* Skip the BOM and use native byte ordering */
 #if PY_BIG_ENDIAN
-        return utf32be_encode(self, text);
+        return utf32be_encode(op, text);
 #else
-        return utf32le_encode(self, text);
+        return utf32le_encode(op, text);
 #endif
     }
-    return _PyUnicode_EncodeUTF32(text,
-                                  PyUnicode_AsUTF8(self->errors), 0);
+    return _PyUnicode_EncodeUTF32(text, PyUnicode_AsUTF8(self->errors), 0);
 }
 
 static PyObject *
-utf8_encode(textio *self, PyObject *text)
+utf8_encode(PyObject *op, PyObject *text)
 {
+    textio *self = _textio_CAST(op);
     return _PyUnicode_AsUTF8String(text, PyUnicode_AsUTF8(self->errors));
 }
 
 static PyObject *
-latin1_encode(textio *self, PyObject *text)
+latin1_encode(PyObject *op, PyObject *text)
 {
+    textio *self = _textio_CAST(op);
     return _PyUnicode_AsLatin1String(text, PyUnicode_AsUTF8(self->errors));
 }
 
@@ -806,9 +809,7 @@ latin1_encode(textio *self, PyObject *text)
 static inline int
 is_asciicompat_encoding(encodefunc_t f)
 {
-    return f == (encodefunc_t) ascii_encode
-        || f == (encodefunc_t) latin1_encode
-        || f == (encodefunc_t) utf8_encode;
+    return f == ascii_encode || f == latin1_encode || f == utf8_encode;
 }
 
 /* Map normalized encoding names onto the specialized encoding funcs */
@@ -819,15 +820,15 @@ typedef struct {
 } encodefuncentry;
 
 static const encodefuncentry encodefuncs[] = {
-    {"ascii",       (encodefunc_t) ascii_encode},
-    {"iso8859-1",   (encodefunc_t) latin1_encode},
-    {"utf-8",       (encodefunc_t) utf8_encode},
-    {"utf-16-be",   (encodefunc_t) utf16be_encode},
-    {"utf-16-le",   (encodefunc_t) utf16le_encode},
-    {"utf-16",      (encodefunc_t) utf16_encode},
-    {"utf-32-be",   (encodefunc_t) utf32be_encode},
-    {"utf-32-le",   (encodefunc_t) utf32le_encode},
-    {"utf-32",      (encodefunc_t) utf32_encode},
+    {"ascii",       ascii_encode},
+    {"iso8859-1",   latin1_encode},
+    {"utf-8",       utf8_encode},
+    {"utf-16-be",   utf16be_encode},
+    {"utf-16-le",   utf16le_encode},
+    {"utf-16",      utf16_encode},
+    {"utf-32-be",   utf32be_encode},
+    {"utf-32-le",   utf32le_encode},
+    {"utf-32",      utf32_encode},
     {NULL, NULL}
 };
 
@@ -1437,8 +1438,9 @@ _io_TextIOWrapper_reconfigure_impl(textio *self, PyObject *encoding,
 }
 
 static int
-textiowrapper_clear(textio *self)
+textiowrapper_clear(PyObject *op)
 {
+    textio *self = _textio_CAST(op);
     self->ok = 0;
     Py_CLEAR(self->buffer);
     Py_CLEAR(self->encoding);
@@ -1456,24 +1458,26 @@ textiowrapper_clear(textio *self)
 }
 
 static void
-textiowrapper_dealloc(textio *self)
+textiowrapper_dealloc(PyObject *op)
 {
+    textio *self = _textio_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     self->finalizing = 1;
-    if (_PyIOBase_finalize((PyObject *) self) < 0)
+    if (_PyIOBase_finalize(op) < 0)
         return;
     self->ok = 0;
     _PyObject_GC_UNTRACK(self);
     if (self->weakreflist != NULL)
-        PyObject_ClearWeakRefs((PyObject *)self);
-    (void)textiowrapper_clear(self);
-    tp->tp_free((PyObject *)self);
+        PyObject_ClearWeakRefs(op);
+    (void)textiowrapper_clear(op);
+    tp->tp_free(self);
     Py_DECREF(tp);
 }
 
 static int
-textiowrapper_traverse(textio *self, visitproc visit, void *arg)
+textiowrapper_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    textio *self = _textio_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->buffer);
     Py_VISIT(self->encoding);
@@ -2967,10 +2971,11 @@ _io_TextIOWrapper_truncate_impl(textio *self, PyObject *pos)
 }
 
 static PyObject *
-textiowrapper_repr(textio *self)
+textiowrapper_repr(PyObject *op)
 {
     PyObject *nameobj, *modeobj, *res, *s;
     int status;
+    textio *self = _textio_CAST(op);
     const char *type_name = Py_TYPE(self)->tp_name;
 
     CHECK_INITIALIZED(self);
@@ -2979,7 +2984,7 @@ textiowrapper_repr(textio *self)
     if (res == NULL)
         return NULL;
 
-    status = Py_ReprEnter((PyObject *)self);
+    status = Py_ReprEnter(op);
     if (status != 0) {
         if (status > 0) {
             PyErr_Format(PyExc_RuntimeError,
@@ -2988,7 +2993,7 @@ textiowrapper_repr(textio *self)
         }
         goto error;
     }
-    if (PyObject_GetOptionalAttr((PyObject *) self, &_Py_ID(name), &nameobj) < 0) {
+    if (PyObject_GetOptionalAttr(op, &_Py_ID(name), &nameobj) < 0) {
         if (!PyErr_ExceptionMatches(PyExc_ValueError)) {
             goto error;
         }
@@ -3004,7 +3009,7 @@ textiowrapper_repr(textio *self)
         if (res == NULL)
             goto error;
     }
-    if (PyObject_GetOptionalAttr((PyObject *) self, &_Py_ID(mode), &modeobj) < 0) {
+    if (PyObject_GetOptionalAttr(op, &_Py_ID(mode), &modeobj) < 0) {
         goto error;
     }
     if (modeobj != NULL) {
@@ -3020,14 +3025,14 @@ textiowrapper_repr(textio *self)
                              res, self->encoding);
     Py_DECREF(res);
     if (status == 0) {
-        Py_ReprLeave((PyObject *)self);
+        Py_ReprLeave(op);
     }
     return s;
 
   error:
     Py_XDECREF(res);
     if (status == 0) {
-        Py_ReprLeave((PyObject *)self);
+        Py_ReprLeave(op);
     }
     return NULL;
 }
@@ -3167,9 +3172,10 @@ _io_TextIOWrapper_close_impl(textio *self)
 }
 
 static PyObject *
-textiowrapper_iternext(textio *self)
+textiowrapper_iternext(PyObject *op)
 {
     PyObject *line;
+    textio *self = _textio_CAST(op);
 
     CHECK_ATTACHED(self);
 
@@ -3179,8 +3185,7 @@ textiowrapper_iternext(textio *self)
         line = _textiowrapper_readline(self, -1);
     }
     else {
-        line = PyObject_CallMethodNoArgs((PyObject *)self,
-                                          &_Py_ID(readline));
+        line = PyObject_CallMethodNoArgs(op, &_Py_ID(readline));
         if (line && !PyUnicode_Check(line)) {
             PyErr_Format(PyExc_OSError,
                          "readline() should have returned a str object, "

From 249ec3e4f257a480f1d12377cf343c09679df46b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 20 Jan 2025 17:17:07 +0100
Subject: [PATCH 09/16] fix UBSan failures for `winconsoleio`

---
 Modules/_io/winconsoleio.c | 37 +++++++++++++++++++++++--------------
 1 file changed, 23 insertions(+), 14 deletions(-)

diff --git a/Modules/_io/winconsoleio.c b/Modules/_io/winconsoleio.c
index 3fa0301e337991..48886c3b3f507b 100644
--- a/Modules/_io/winconsoleio.c
+++ b/Modules/_io/winconsoleio.c
@@ -221,6 +221,8 @@ typedef struct {
     wchar_t wbuf;
 } winconsoleio;
 
+#define _winconsoleio_CAST(op)  ((winconsoleio *)(op))
+
 int
 _PyWindowsConsoleIO_closed(PyObject *self)
 {
@@ -492,32 +494,35 @@ _io__WindowsConsoleIO___init___impl(winconsoleio *self, PyObject *nameobj,
 }
 
 static int
-winconsoleio_traverse(winconsoleio *self, visitproc visit, void *arg)
+winconsoleio_traverse(PyObject *op, visitproc visit, void *arg)
 {
+    winconsoleio *self = _winconsoleio_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->dict);
     return 0;
 }
 
 static int
-winconsoleio_clear(winconsoleio *self)
+winconsoleio_clear(PyObject *op)
 {
+    winconsoleio *self = _winconsoleio_CAST(op);
     Py_CLEAR(self->dict);
     return 0;
 }
 
 static void
-winconsoleio_dealloc(winconsoleio *self)
+winconsoleio_dealloc(PyObject *op)
 {
+    winconsoleio *self = _winconsoleio_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     self->finalizing = 1;
-    if (_PyIOBase_finalize((PyObject *) self) < 0)
+    if (_PyIOBase_finalize(op) < 0)
         return;
     _PyObject_GC_UNTRACK(self);
     if (self->weakreflist != NULL)
-        PyObject_ClearWeakRefs((PyObject *) self);
+        PyObject_ClearWeakRefs(op);
     Py_CLEAR(self->dict);
-    tp->tp_free((PyObject *)self);
+    tp->tp_free(self);
     Py_DECREF(tp);
 }
 
@@ -1137,9 +1142,10 @@ _io__WindowsConsoleIO_write_impl(winconsoleio *self, PyTypeObject *cls,
 }
 
 static PyObject *
-winconsoleio_repr(winconsoleio *self)
+winconsoleio_repr(PyObject *op)
 {
-    const char *type_name = (Py_TYPE((PyObject *)self)->tp_name);
+    winconsoleio *self = _winconsoleio_CAST(op);
+    const char *type_name = Py_TYPE(self)->tp_name;
 
     if (self->fd == -1) {
         return PyUnicode_FromFormat("<%.100s [closed]>", type_name);
@@ -1197,28 +1203,31 @@ static PyMethodDef winconsoleio_methods[] = {
 /* 'closed' and 'mode' are attributes for compatibility with FileIO. */
 
 static PyObject *
-get_closed(winconsoleio *self, void *closure)
+get_closed(PyObject *op, void *Py_UNUSED(closure))
 {
+    winconsoleio *self = _winconsoleio_CAST(op);
     return PyBool_FromLong((long)(self->fd == -1));
 }
 
 static PyObject *
-get_closefd(winconsoleio *self, void *closure)
+get_closefd(PyObject *op, void *Py_UNUSED(closure))
 {
+    winconsoleio *self = _winconsoleio_CAST(op);
     return PyBool_FromLong((long)(self->closefd));
 }
 
 static PyObject *
-get_mode(winconsoleio *self, void *closure)
+get_mode(PyObject *op, void *Py_UNUSED(closure))
 {
+    winconsoleio *self = _winconsoleio_CAST(op);
     return PyUnicode_FromString(self->readable ? "rb" : "wb");
 }
 
 static PyGetSetDef winconsoleio_getsetlist[] = {
-    {"closed", (getter)get_closed, NULL, "True if the file is closed"},
-    {"closefd", (getter)get_closefd, NULL,
+    {"closed", get_closed, NULL, "True if the file is closed"},
+    {"closefd", get_closefd, NULL,
         "True if the file descriptor will be closed by close()."},
-    {"mode", (getter)get_mode, NULL, "String giving the file mode"},
+    {"mode", get_mode, NULL, "String giving the file mode"},
     {NULL},
 };
 

From cf4414173930baffb7e258e8cbeaee81ae51690b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 20 Jan 2025 17:28:11 +0100
Subject: [PATCH 10/16] reduce diff

---
 Modules/_io/bufferedio.c |  2 +-
 Modules/_io/bytesio.c    |  2 +-
 Modules/_io/iobase.c     | 12 ++++++------
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index 10531cbab00b02..cbcb4e80b1c56e 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -430,7 +430,7 @@ buffered_dealloc(PyObject *op)
         self->lock = NULL;
     }
     (void)buffered_clear(op);
-    tp->tp_free(op);
+    tp->tp_free(self);
     Py_DECREF(tp);
 }
 
diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c
index 0fd3cc96e4a85d..aac664e0d3d77d 100644
--- a/Modules/_io/bytesio.c
+++ b/Modules/_io/bytesio.c
@@ -895,7 +895,7 @@ bytesio_dealloc(PyObject *op)
 {
     bytesio *self = _bytesio_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
-    _PyObject_GC_UNTRACK(op);
+    _PyObject_GC_UNTRACK(self);
     if (self->exports > 0) {
         PyErr_SetString(PyExc_SystemError,
                         "deallocated BytesIO object has exported buffers");
diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index 23ea8357ef9ad0..64b94d4ab23607 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -362,15 +362,15 @@ iobase_clear(PyObject *op)
 /* Destructor */
 
 static void
-iobase_dealloc(PyObject *self)
+iobase_dealloc(PyObject *op)
 {
     /* NOTE: since IOBaseObject has its own dict, Python-defined attributes
        are still available here for close() to use.
        However, if the derived class declares a __slots__, those slots are
        already gone.
     */
-    iobase *base = _iobase_CAST(self);
-    if (_PyIOBase_finalize(self) < 0) {
+    iobase *self = _iobase_CAST(op);
+    if (_PyIOBase_finalize(op) < 0) {
         /* When called from a heap type's dealloc, the type will be
            decref'ed on return (see e.g. subtype_dealloc in typeobject.c). */
         if (_PyType_HasFeature(Py_TYPE(self), Py_TPFLAGS_HEAPTYPE)) {
@@ -380,9 +380,9 @@ iobase_dealloc(PyObject *self)
     }
     PyTypeObject *tp = Py_TYPE(self);
     _PyObject_GC_UNTRACK(self);
-    if (base->weakreflist != NULL)
-        PyObject_ClearWeakRefs(self);
-    Py_CLEAR(base->dict);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
+    Py_CLEAR(self->dict);
     tp->tp_free(self);
     Py_DECREF(tp);
 }

From a9b3ca616b6d930e3db71e5e9541192dc29a9ec3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Mon, 20 Jan 2025 17:31:51 +0100
Subject: [PATCH 11/16] add some new lines

---
 Modules/_io/bufferedio.c | 2 ++
 Modules/_io/iobase.c     | 1 +
 Modules/_io/textio.c     | 2 ++
 3 files changed, 5 insertions(+)

diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index cbcb4e80b1c56e..19db4922c00d7c 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -260,6 +260,7 @@ typedef struct {
     PyObject *dict;
     PyObject *weakreflist;
 } buffered;
+
 #define _buffered_CAST(op)  ((buffered *)(op))
 
 /*
@@ -2229,6 +2230,7 @@ typedef struct {
     PyObject *dict;
     PyObject *weakreflist;
 } rwpair;
+
 #define _rwpair_CAST(op)    ((rwpair *)(op))
 
 /*[clinic input]
diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index 64b94d4ab23607..744e8d45de98d5 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -34,6 +34,7 @@ typedef struct {
     PyObject *dict;
     PyObject *weakreflist;
 } iobase;
+
 #define _iobase_CAST(op)    ((iobase *)(op))
 
 PyDoc_STRVAR(iobase_doc,
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index dca22d013b751f..92bf3c45583f60 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -222,6 +222,7 @@ struct nldecoder_object {
     unsigned int translate: 1;
     unsigned int seennl: 3;
 };
+
 #define _nldecoder_object_CAST(op)  ((nldecoder_object *)(op))
 
 /*[clinic input]
@@ -718,6 +719,7 @@ struct textio
 
     _PyIO_State *state;
 };
+
 #define _textio_CAST(op)    ((textio *)(op))
 
 static void

From 416d7405f4dc7669fa50d4d9aa06370c3058e969 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Sat, 25 Jan 2025 20:40:03 +0100
Subject: [PATCH 12/16] post-merge fix

---
 Modules/_io/stringio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Modules/_io/stringio.c b/Modules/_io/stringio.c
index 6bd72a72b32c85..949c4ae0e67a6a 100644
--- a/Modules/_io/stringio.c
+++ b/Modules/_io/stringio.c
@@ -627,7 +627,7 @@ stringio_dealloc(PyObject *op)
         self->buf = NULL;
     }
     PyUnicodeWriter_Discard(self->writer);
-    (void)stringio_clear(self);
+    (void)stringio_clear(op);
     if (self->weakreflist != NULL) {
         PyObject_ClearWeakRefs(op);
     }

From c6f2d0ee2e452ca5ad1f6383caf9bd96076572de Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Thu, 6 Feb 2025 17:44:14 +0100
Subject: [PATCH 13/16] use 'ignored' for NOARGS method and 'args' for others

---
 Modules/_io/bytesio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c
index aac664e0d3d77d..b8a5d8440581f4 100644
--- a/Modules/_io/bytesio.c
+++ b/Modules/_io/bytesio.c
@@ -970,7 +970,7 @@ _io_BytesIO___init___impl(bytesio *self, PyObject *initvalue)
 }
 
 static PyObject *
-bytesio_sizeof(PyObject *op, PyObject *Py_UNUSED(args))
+bytesio_sizeof(PyObject *op, PyObject *Py_UNUSED(ignored))
 {
     bytesio *self = _bytesio_CAST(op);
     size_t res = _PyObject_SIZE(Py_TYPE(self));

From ec1e15d5636377000e198d7a8daf7d86ef88bed3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Thu, 6 Feb 2025 17:49:38 +0100
Subject: [PATCH 14/16] use 'dummy' for NOARGS method

---
 Modules/_io/bufferedio.c | 12 ++++++------
 Modules/_io/bytesio.c    |  6 +++---
 Modules/_io/fileio.c     |  2 +-
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index 19db4922c00d7c..477c98d03ab61d 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -2379,28 +2379,28 @@ bufferedrwpair_write(PyObject *op, PyObject *args)
 }
 
 static PyObject *
-bufferedrwpair_flush(PyObject *op, PyObject *Py_UNUSED(ignored))
+bufferedrwpair_flush(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
     rwpair *self = _rwpair_CAST(op);
     return _forward_call(self->writer, &_Py_ID(flush), NULL);
 }
 
 static PyObject *
-bufferedrwpair_readable(PyObject *op, PyObject *Py_UNUSED(ignored))
+bufferedrwpair_readable(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
     rwpair *self = _rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(readable), NULL);
 }
 
 static PyObject *
-bufferedrwpair_writable(PyObject *op, PyObject *Py_UNUSED(ignored))
+bufferedrwpair_writable(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
     rwpair *self = _rwpair_CAST(op);
     return _forward_call(self->writer, &_Py_ID(writable), NULL);
 }
 
 static PyObject *
-bufferedrwpair_close(PyObject *op, PyObject *Py_UNUSED(ignored))
+bufferedrwpair_close(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
     rwpair *self = _rwpair_CAST(op);
     PyObject *exc = NULL;
@@ -2420,7 +2420,7 @@ bufferedrwpair_close(PyObject *op, PyObject *Py_UNUSED(ignored))
 }
 
 static PyObject *
-bufferedrwpair_isatty(PyObject *op, PyObject *Py_UNUSED(ignored))
+bufferedrwpair_isatty(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
     rwpair *self = _rwpair_CAST(op);
     PyObject *ret = _forward_call(self->writer, &_Py_ID(isatty), NULL);
@@ -2435,7 +2435,7 @@ bufferedrwpair_isatty(PyObject *op, PyObject *Py_UNUSED(ignored))
 }
 
 static PyObject *
-bufferedrwpair_closed_get(PyObject *op, void *Py_UNUSED(context))
+bufferedrwpair_closed_get(PyObject *op, void *Py_UNUSED(dummy))
 {
     rwpair *self = _rwpair_CAST(op);
     if (self->writer == NULL) {
diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c
index b8a5d8440581f4..f95fe2508d1f71 100644
--- a/Modules/_io/bytesio.c
+++ b/Modules/_io/bytesio.c
@@ -243,7 +243,7 @@ write_bytes(bytesio *self, PyObject *b)
 }
 
 static PyObject *
-bytesio_get_closed(PyObject *op, void *Py_UNUSED(ignored))
+bytesio_get_closed(PyObject *op, void *Py_UNUSED(closure))
 {
     bytesio *self = _bytesio_CAST(op);
     if (self->buf == NULL) {
@@ -789,7 +789,7 @@ _io_BytesIO_close_impl(bytesio *self)
  */
 
 static PyObject *
-bytesio_getstate(PyObject *op, PyObject *Py_UNUSED(ignored))
+bytesio_getstate(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
     bytesio *self = _bytesio_CAST(op);
     PyObject *initvalue = _io_BytesIO_getvalue_impl(self);
@@ -970,7 +970,7 @@ _io_BytesIO___init___impl(bytesio *self, PyObject *initvalue)
 }
 
 static PyObject *
-bytesio_sizeof(PyObject *op, PyObject *Py_UNUSED(ignored))
+bytesio_sizeof(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
     bytesio *self = _bytesio_CAST(op);
     size_t res = _PyObject_SIZE(Py_TYPE(self));
diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index cf0f1d671b507a..49d01e2ba2f779 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -1225,7 +1225,7 @@ _io_FileIO_isatty_impl(fileio *self)
    context TOCTOU issues (the fd could be arbitrarily modified by
    surrounding code). */
 static PyObject *
-_io_FileIO_isatty_open_only(PyObject *op, PyObject *Py_UNUSED(ignored))
+_io_FileIO_isatty_open_only(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
     fileio *self = _PyFileIO_CAST(op);
     if (self->stat_atopen != NULL && !S_ISCHR(self->stat_atopen->st_mode)) {

From bb95ac083f694a2c18755f38563b00f71d983c93 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Sat, 8 Feb 2025 10:43:23 +0100
Subject: [PATCH 15/16] Do not add an underscore to the macro if none is
 needed.

---
 Modules/_io/bufferedio.c   | 38 +++++++++++++++++-----------------
 Modules/_io/bytesio.c      | 32 ++++++++++++++---------------
 Modules/_io/iobase.c       |  8 ++++----
 Modules/_io/stringio.c     | 10 ++++-----
 Modules/_io/textio.c       | 42 +++++++++++++++++++-------------------
 Modules/_io/winconsoleio.c | 16 +++++++--------
 6 files changed, 73 insertions(+), 73 deletions(-)

diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
index 477c98d03ab61d..53c4702f673786 100644
--- a/Modules/_io/bufferedio.c
+++ b/Modules/_io/bufferedio.c
@@ -261,7 +261,7 @@ typedef struct {
     PyObject *weakreflist;
 } buffered;
 
-#define _buffered_CAST(op)  ((buffered *)(op))
+#define buffered_CAST(op)   ((buffered *)(op))
 
 /*
     Implementation notes:
@@ -403,7 +403,7 @@ _enter_buffered_busy(buffered *self)
 static int
 buffered_clear(PyObject *op)
 {
-    buffered *self = _buffered_CAST(op);
+    buffered *self = buffered_CAST(op);
     self->ok = 0;
     Py_CLEAR(self->raw);
     Py_CLEAR(self->dict);
@@ -413,7 +413,7 @@ buffered_clear(PyObject *op)
 static void
 buffered_dealloc(PyObject *op)
 {
-    buffered *self = _buffered_CAST(op);
+    buffered *self = buffered_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     self->finalizing = 1;
     if (_PyIOBase_finalize(op) < 0)
@@ -2231,7 +2231,7 @@ typedef struct {
     PyObject *weakreflist;
 } rwpair;
 
-#define _rwpair_CAST(op)    ((rwpair *)(op))
+#define rwpair_CAST(op) ((rwpair *)(op))
 
 /*[clinic input]
 _io.BufferedRWPair.__init__
@@ -2284,7 +2284,7 @@ _io_BufferedRWPair___init___impl(rwpair *self, PyObject *reader,
 static int
 bufferedrwpair_traverse(PyObject *op, visitproc visit, void *arg)
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->dict);
     Py_VISIT(self->reader);
@@ -2295,7 +2295,7 @@ bufferedrwpair_traverse(PyObject *op, visitproc visit, void *arg)
 static int
 bufferedrwpair_clear(PyObject *op)
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     Py_CLEAR(self->reader);
     Py_CLEAR(self->writer);
     Py_CLEAR(self->dict);
@@ -2305,7 +2305,7 @@ bufferedrwpair_clear(PyObject *op)
 static void
 bufferedrwpair_dealloc(PyObject *op)
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     _PyObject_GC_UNTRACK(self);
     if (self->weakreflist != NULL)
@@ -2339,70 +2339,70 @@ _forward_call(buffered *self, PyObject *name, PyObject *args)
 static PyObject *
 bufferedrwpair_read(PyObject *op, PyObject *args)
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(read), args);
 }
 
 static PyObject *
 bufferedrwpair_peek(PyObject *op, PyObject *args)
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(peek), args);
 }
 
 static PyObject *
 bufferedrwpair_read1(PyObject *op, PyObject *args)
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(read1), args);
 }
 
 static PyObject *
 bufferedrwpair_readinto(PyObject *op, PyObject *args)
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(readinto), args);
 }
 
 static PyObject *
 bufferedrwpair_readinto1(PyObject *op, PyObject *args)
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(readinto1), args);
 }
 
 static PyObject *
 bufferedrwpair_write(PyObject *op, PyObject *args)
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     return _forward_call(self->writer, &_Py_ID(write), args);
 }
 
 static PyObject *
 bufferedrwpair_flush(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     return _forward_call(self->writer, &_Py_ID(flush), NULL);
 }
 
 static PyObject *
 bufferedrwpair_readable(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     return _forward_call(self->reader, &_Py_ID(readable), NULL);
 }
 
 static PyObject *
 bufferedrwpair_writable(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     return _forward_call(self->writer, &_Py_ID(writable), NULL);
 }
 
 static PyObject *
 bufferedrwpair_close(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     PyObject *exc = NULL;
     PyObject *ret = _forward_call(self->writer, &_Py_ID(close), NULL);
     if (ret == NULL) {
@@ -2422,7 +2422,7 @@ bufferedrwpair_close(PyObject *op, PyObject *Py_UNUSED(dummy))
 static PyObject *
 bufferedrwpair_isatty(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     PyObject *ret = _forward_call(self->writer, &_Py_ID(isatty), NULL);
 
     if (ret != Py_False) {
@@ -2437,7 +2437,7 @@ bufferedrwpair_isatty(PyObject *op, PyObject *Py_UNUSED(dummy))
 static PyObject *
 bufferedrwpair_closed_get(PyObject *op, void *Py_UNUSED(dummy))
 {
-    rwpair *self = _rwpair_CAST(op);
+    rwpair *self = rwpair_CAST(op);
     if (self->writer == NULL) {
         PyErr_SetString(PyExc_RuntimeError,
                 "the BufferedRWPair object is being garbage-collected");
diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c
index f95fe2508d1f71..dc4e40b9f09a1d 100644
--- a/Modules/_io/bytesio.c
+++ b/Modules/_io/bytesio.c
@@ -21,14 +21,14 @@ typedef struct {
     Py_ssize_t exports;
 } bytesio;
 
-#define _bytesio_CAST(op)   ((bytesio *)(op))
+#define bytesio_CAST(op)    ((bytesio *)(op))
 
 typedef struct {
     PyObject_HEAD
     bytesio *source;
 } bytesiobuf;
 
-#define _bytesiobuf_CAST(op)    ((bytesiobuf *)(op))
+#define bytesiobuf_CAST(op) ((bytesiobuf *)(op))
 
 /* The bytesio object can be in three states:
   * Py_REFCNT(buf) == 1, exports == 0.
@@ -245,7 +245,7 @@ write_bytes(bytesio *self, PyObject *b)
 static PyObject *
 bytesio_get_closed(PyObject *op, void *Py_UNUSED(closure))
 {
-    bytesio *self = _bytesio_CAST(op);
+    bytesio *self = bytesio_CAST(op);
     if (self->buf == NULL) {
         Py_RETURN_TRUE;
     }
@@ -628,7 +628,7 @@ static PyObject *
 bytesio_iternext(PyObject *op)
 {
     Py_ssize_t n;
-    bytesio *self = _bytesio_CAST(op);
+    bytesio *self = bytesio_CAST(op);
 
     CHECK_CLOSED(self);
 
@@ -791,7 +791,7 @@ _io_BytesIO_close_impl(bytesio *self)
 static PyObject *
 bytesio_getstate(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
-    bytesio *self = _bytesio_CAST(op);
+    bytesio *self = bytesio_CAST(op);
     PyObject *initvalue = _io_BytesIO_getvalue_impl(self);
     PyObject *dict;
     PyObject *state;
@@ -821,7 +821,7 @@ bytesio_setstate(PyObject *op, PyObject *state)
     PyObject *position_obj;
     PyObject *dict;
     Py_ssize_t pos;
-    bytesio *self = _bytesio_CAST(op);
+    bytesio *self = bytesio_CAST(op);
 
     assert(state != NULL);
 
@@ -893,7 +893,7 @@ bytesio_setstate(PyObject *op, PyObject *state)
 static void
 bytesio_dealloc(PyObject *op)
 {
-    bytesio *self = _bytesio_CAST(op);
+    bytesio *self = bytesio_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     _PyObject_GC_UNTRACK(self);
     if (self->exports > 0) {
@@ -972,7 +972,7 @@ _io_BytesIO___init___impl(bytesio *self, PyObject *initvalue)
 static PyObject *
 bytesio_sizeof(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
-    bytesio *self = _bytesio_CAST(op);
+    bytesio *self = bytesio_CAST(op);
     size_t res = _PyObject_SIZE(Py_TYPE(self));
     if (self->buf && !SHARED_BUF(self)) {
         size_t s = _PySys_GetSizeOf(self->buf);
@@ -987,7 +987,7 @@ bytesio_sizeof(PyObject *op, PyObject *Py_UNUSED(dummy))
 static int
 bytesio_traverse(PyObject *op, visitproc visit, void *arg)
 {
-    bytesio *self = _bytesio_CAST(op);
+    bytesio *self = bytesio_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->dict);
     Py_VISIT(self->buf);
@@ -997,7 +997,7 @@ bytesio_traverse(PyObject *op, visitproc visit, void *arg)
 static int
 bytesio_clear(PyObject *op)
 {
-    bytesio *self = _bytesio_CAST(op);
+    bytesio *self = bytesio_CAST(op);
     Py_CLEAR(self->dict);
     if (self->exports == 0) {
         Py_CLEAR(self->buf);
@@ -1079,8 +1079,8 @@ PyType_Spec bytesio_spec = {
 static int
 bytesiobuf_getbuffer(PyObject *op, Py_buffer *view, int flags)
 {
-    bytesiobuf *obj = _bytesiobuf_CAST(op);
-    bytesio *b = _bytesio_CAST(obj->source);
+    bytesiobuf *obj = bytesiobuf_CAST(op);
+    bytesio *b = bytesio_CAST(obj->source);
 
     if (view == NULL) {
         PyErr_SetString(PyExc_BufferError,
@@ -1103,15 +1103,15 @@ bytesiobuf_getbuffer(PyObject *op, Py_buffer *view, int flags)
 static void
 bytesiobuf_releasebuffer(PyObject *op, Py_buffer *Py_UNUSED(view))
 {
-    bytesiobuf *obj = _bytesiobuf_CAST(op);
-    bytesio *b = _bytesio_CAST(obj->source);
+    bytesiobuf *obj = bytesiobuf_CAST(op);
+    bytesio *b = bytesio_CAST(obj->source);
     b->exports--;
 }
 
 static int
 bytesiobuf_traverse(PyObject *op, visitproc visit, void *arg)
 {
-    bytesiobuf *self = _bytesiobuf_CAST(op);
+    bytesiobuf *self = bytesiobuf_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->source);
     return 0;
@@ -1120,7 +1120,7 @@ bytesiobuf_traverse(PyObject *op, visitproc visit, void *arg)
 static void
 bytesiobuf_dealloc(PyObject *op)
 {
-    bytesiobuf *self = _bytesiobuf_CAST(op);
+    bytesiobuf *self = bytesiobuf_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     /* bpo-31095: UnTrack is needed before calling any callbacks */
     PyObject_GC_UnTrack(op);
diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index 59e3878ab63c01..7e0822e3350eeb 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -35,7 +35,7 @@ typedef struct {
     PyObject *weakreflist;
 } iobase;
 
-#define _iobase_CAST(op)    ((iobase *)(op))
+#define iobase_CAST(op) ((iobase *)(op))
 
 PyDoc_STRVAR(iobase_doc,
     "The abstract base class for all I/O classes.\n"
@@ -347,7 +347,7 @@ _PyIOBase_finalize(PyObject *self)
 static int
 iobase_traverse(PyObject *op, visitproc visit, void *arg)
 {
-    iobase *self = _iobase_CAST(op);
+    iobase *self = iobase_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->dict);
     return 0;
@@ -356,7 +356,7 @@ iobase_traverse(PyObject *op, visitproc visit, void *arg)
 static int
 iobase_clear(PyObject *op)
 {
-    iobase *self = _iobase_CAST(op);
+    iobase *self = iobase_CAST(op);
     Py_CLEAR(self->dict);
     return 0;
 }
@@ -371,7 +371,7 @@ iobase_dealloc(PyObject *op)
        However, if the derived class declares a __slots__, those slots are
        already gone.
     */
-    iobase *self = _iobase_CAST(op);
+    iobase *self = iobase_CAST(op);
     if (_PyIOBase_finalize(op) < 0) {
         /* When called from a heap type's dealloc, the type will be
            decref'ed on return (see e.g. subtype_dealloc in typeobject.c). */
diff --git a/Modules/_io/stringio.c b/Modules/_io/stringio.c
index 949c4ae0e67a6a..9d1bfa3ea05cea 100644
--- a/Modules/_io/stringio.c
+++ b/Modules/_io/stringio.c
@@ -45,7 +45,7 @@ typedef struct {
     _PyIO_State *module_state;
 } stringio;
 
-#define _stringio_CAST(op)  ((stringio *)(op))
+#define stringio_CAST(op)   ((stringio *)(op))
 
 #define clinic_state() (find_io_state_by_def(Py_TYPE(self)))
 #include "clinic/stringio.c.h"
@@ -407,7 +407,7 @@ static PyObject *
 stringio_iternext(PyObject *op)
 {
     PyObject *line;
-    stringio *self = _stringio_CAST(op);
+    stringio *self = stringio_CAST(op);
 
     CHECK_INITIALIZED(self);
     CHECK_CLOSED(self);
@@ -595,7 +595,7 @@ _io_StringIO_close_impl(stringio *self)
 static int
 stringio_traverse(PyObject *op, visitproc visit, void *arg)
 {
-    stringio *self = _stringio_CAST(op);
+    stringio *self = stringio_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->readnl);
     Py_VISIT(self->writenl);
@@ -607,7 +607,7 @@ stringio_traverse(PyObject *op, visitproc visit, void *arg)
 static int
 stringio_clear(PyObject *op)
 {
-    stringio *self = _stringio_CAST(op);
+    stringio *self = stringio_CAST(op);
     Py_CLEAR(self->readnl);
     Py_CLEAR(self->writenl);
     Py_CLEAR(self->decoder);
@@ -618,7 +618,7 @@ stringio_clear(PyObject *op)
 static void
 stringio_dealloc(PyObject *op)
 {
-    stringio *self = _stringio_CAST(op);
+    stringio *self = stringio_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     _PyObject_GC_UNTRACK(self);
     self->ok = 0;
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index 92bf3c45583f60..935aaab20a031f 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -223,7 +223,7 @@ struct nldecoder_object {
     unsigned int seennl: 3;
 };
 
-#define _nldecoder_object_CAST(op)  ((nldecoder_object *)(op))
+#define nldecoder_object_CAST(op)   ((nldecoder_object *)(op))
 
 /*[clinic input]
 _io.IncrementalNewlineDecoder.__init__
@@ -267,7 +267,7 @@ _io_IncrementalNewlineDecoder___init___impl(nldecoder_object *self,
 static int
 incrementalnewlinedecoder_traverse(PyObject *op, visitproc visit, void *arg)
 {
-    nldecoder_object *self = _nldecoder_object_CAST(op);
+    nldecoder_object *self = nldecoder_object_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->decoder);
     Py_VISIT(self->errors);
@@ -277,7 +277,7 @@ incrementalnewlinedecoder_traverse(PyObject *op, visitproc visit, void *arg)
 static int
 incrementalnewlinedecoder_clear(PyObject *op)
 {
-    nldecoder_object *self = _nldecoder_object_CAST(op);
+    nldecoder_object *self = nldecoder_object_CAST(op);
     Py_CLEAR(self->decoder);
     Py_CLEAR(self->errors);
     return 0;
@@ -286,7 +286,7 @@ incrementalnewlinedecoder_clear(PyObject *op)
 static void
 incrementalnewlinedecoder_dealloc(PyObject *op)
 {
-    nldecoder_object *self = _nldecoder_object_CAST(op);
+    nldecoder_object *self = nldecoder_object_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     _PyObject_GC_UNTRACK(self);
     (void)incrementalnewlinedecoder_clear(op);
@@ -327,7 +327,7 @@ _PyIncrementalNewlineDecoder_decode(PyObject *myself,
 {
     PyObject *output;
     Py_ssize_t output_len;
-    nldecoder_object *self = _nldecoder_object_CAST(myself);
+    nldecoder_object *self = nldecoder_object_CAST(myself);
 
     CHECK_INITIALIZED_DECODER(self);
 
@@ -631,7 +631,7 @@ _io_IncrementalNewlineDecoder_reset_impl(nldecoder_object *self)
 static PyObject *
 incrementalnewlinedecoder_newlines_get(PyObject *op, void *Py_UNUSED(context))
 {
-    nldecoder_object *self = _nldecoder_object_CAST(op);
+    nldecoder_object *self = nldecoder_object_CAST(op);
     CHECK_INITIALIZED_DECODER(self);
 
     switch (self->seennl) {
@@ -720,7 +720,7 @@ struct textio
     _PyIO_State *state;
 };
 
-#define _textio_CAST(op)    ((textio *)(op))
+#define textio_CAST(op) ((textio *)(op))
 
 static void
 textiowrapper_set_decoded_chars(textio *self, PyObject *chars);
@@ -731,28 +731,28 @@ textiowrapper_set_decoded_chars(textio *self, PyObject *chars);
 static PyObject *
 ascii_encode(PyObject *op, PyObject *text)
 {
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     return _PyUnicode_AsASCIIString(text, PyUnicode_AsUTF8(self->errors));
 }
 
 static PyObject *
 utf16be_encode(PyObject *op, PyObject *text)
 {
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     return _PyUnicode_EncodeUTF16(text, PyUnicode_AsUTF8(self->errors), 1);
 }
 
 static PyObject *
 utf16le_encode(PyObject *op, PyObject *text)
 {
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     return _PyUnicode_EncodeUTF16(text, PyUnicode_AsUTF8(self->errors), -1);
 }
 
 static PyObject *
 utf16_encode(PyObject *op, PyObject *text)
 {
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     if (!self->encoding_start_of_stream) {
         /* Skip the BOM and use native byte ordering */
 #if PY_BIG_ENDIAN
@@ -767,21 +767,21 @@ utf16_encode(PyObject *op, PyObject *text)
 static PyObject *
 utf32be_encode(PyObject *op, PyObject *text)
 {
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     return _PyUnicode_EncodeUTF32(text, PyUnicode_AsUTF8(self->errors), 1);
 }
 
 static PyObject *
 utf32le_encode(PyObject *op, PyObject *text)
 {
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     return _PyUnicode_EncodeUTF32(text, PyUnicode_AsUTF8(self->errors), -1);
 }
 
 static PyObject *
 utf32_encode(PyObject *op, PyObject *text)
 {
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     if (!self->encoding_start_of_stream) {
         /* Skip the BOM and use native byte ordering */
 #if PY_BIG_ENDIAN
@@ -796,14 +796,14 @@ utf32_encode(PyObject *op, PyObject *text)
 static PyObject *
 utf8_encode(PyObject *op, PyObject *text)
 {
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     return _PyUnicode_AsUTF8String(text, PyUnicode_AsUTF8(self->errors));
 }
 
 static PyObject *
 latin1_encode(PyObject *op, PyObject *text)
 {
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     return _PyUnicode_AsLatin1String(text, PyUnicode_AsUTF8(self->errors));
 }
 
@@ -1442,7 +1442,7 @@ _io_TextIOWrapper_reconfigure_impl(textio *self, PyObject *encoding,
 static int
 textiowrapper_clear(PyObject *op)
 {
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     self->ok = 0;
     Py_CLEAR(self->buffer);
     Py_CLEAR(self->encoding);
@@ -1462,7 +1462,7 @@ textiowrapper_clear(PyObject *op)
 static void
 textiowrapper_dealloc(PyObject *op)
 {
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     self->finalizing = 1;
     if (_PyIOBase_finalize(op) < 0)
@@ -1479,7 +1479,7 @@ textiowrapper_dealloc(PyObject *op)
 static int
 textiowrapper_traverse(PyObject *op, visitproc visit, void *arg)
 {
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->buffer);
     Py_VISIT(self->encoding);
@@ -2977,7 +2977,7 @@ textiowrapper_repr(PyObject *op)
 {
     PyObject *nameobj, *modeobj, *res, *s;
     int status;
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
     const char *type_name = Py_TYPE(self)->tp_name;
 
     CHECK_INITIALIZED(self);
@@ -3177,7 +3177,7 @@ static PyObject *
 textiowrapper_iternext(PyObject *op)
 {
     PyObject *line;
-    textio *self = _textio_CAST(op);
+    textio *self = textio_CAST(op);
 
     CHECK_ATTACHED(self);
 
diff --git a/Modules/_io/winconsoleio.c b/Modules/_io/winconsoleio.c
index 48886c3b3f507b..27c320ed073103 100644
--- a/Modules/_io/winconsoleio.c
+++ b/Modules/_io/winconsoleio.c
@@ -221,7 +221,7 @@ typedef struct {
     wchar_t wbuf;
 } winconsoleio;
 
-#define _winconsoleio_CAST(op)  ((winconsoleio *)(op))
+#define winconsoleio_CAST(op)   ((winconsoleio *)(op))
 
 int
 _PyWindowsConsoleIO_closed(PyObject *self)
@@ -496,7 +496,7 @@ _io__WindowsConsoleIO___init___impl(winconsoleio *self, PyObject *nameobj,
 static int
 winconsoleio_traverse(PyObject *op, visitproc visit, void *arg)
 {
-    winconsoleio *self = _winconsoleio_CAST(op);
+    winconsoleio *self = winconsoleio_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->dict);
     return 0;
@@ -505,7 +505,7 @@ winconsoleio_traverse(PyObject *op, visitproc visit, void *arg)
 static int
 winconsoleio_clear(PyObject *op)
 {
-    winconsoleio *self = _winconsoleio_CAST(op);
+    winconsoleio *self = winconsoleio_CAST(op);
     Py_CLEAR(self->dict);
     return 0;
 }
@@ -513,7 +513,7 @@ winconsoleio_clear(PyObject *op)
 static void
 winconsoleio_dealloc(PyObject *op)
 {
-    winconsoleio *self = _winconsoleio_CAST(op);
+    winconsoleio *self = winconsoleio_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     self->finalizing = 1;
     if (_PyIOBase_finalize(op) < 0)
@@ -1144,7 +1144,7 @@ _io__WindowsConsoleIO_write_impl(winconsoleio *self, PyTypeObject *cls,
 static PyObject *
 winconsoleio_repr(PyObject *op)
 {
-    winconsoleio *self = _winconsoleio_CAST(op);
+    winconsoleio *self = winconsoleio_CAST(op);
     const char *type_name = Py_TYPE(self)->tp_name;
 
     if (self->fd == -1) {
@@ -1205,21 +1205,21 @@ static PyMethodDef winconsoleio_methods[] = {
 static PyObject *
 get_closed(PyObject *op, void *Py_UNUSED(closure))
 {
-    winconsoleio *self = _winconsoleio_CAST(op);
+    winconsoleio *self = winconsoleio_CAST(op);
     return PyBool_FromLong((long)(self->fd == -1));
 }
 
 static PyObject *
 get_closefd(PyObject *op, void *Py_UNUSED(closure))
 {
-    winconsoleio *self = _winconsoleio_CAST(op);
+    winconsoleio *self = winconsoleio_CAST(op);
     return PyBool_FromLong((long)(self->closefd));
 }
 
 static PyObject *
 get_mode(PyObject *op, void *Py_UNUSED(closure))
 {
-    winconsoleio *self = _winconsoleio_CAST(op);
+    winconsoleio *self = winconsoleio_CAST(op);
     return PyUnicode_FromString(self->readable ? "rb" : "wb");
 }
 

From 2340cae3030ee80583c302880c3ee87ecde929b9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?B=C3=A9n=C3=A9dikt=20Tran?=
 <10796600+picnixz@users.noreply.github.com>
Date: Sat, 8 Feb 2025 10:43:32 +0100
Subject: [PATCH 16/16] Do Do not use `_` + capital letter in cast macros as it
 is also UB.

---
 Modules/_io/fileio.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index 3a098fd76b728f..89f1cfe6b20935 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -83,7 +83,7 @@ typedef struct {
 } fileio;
 
 #define PyFileIO_Check(state, op) (PyObject_TypeCheck((op), state->PyFileIO_Type))
-#define _PyFileIO_CAST(op) _Py_CAST(fileio*, (op))
+#define PyFileIO_CAST(op) ((fileio *)(op))
 
 /* Forward declarations */
 static PyObject* portable_lseek(fileio *self, PyObject *posobj, int whence, bool suppress_pipe_error);
@@ -91,7 +91,7 @@ static PyObject* portable_lseek(fileio *self, PyObject *posobj, int whence, bool
 int
 _PyFileIO_closed(PyObject *self)
 {
-    return (_PyFileIO_CAST(self)->fd < 0);
+    return (PyFileIO_CAST(self)->fd < 0);
 }
 
 /* Because this can call arbitrary code, it shouldn't be called when
@@ -100,7 +100,7 @@ _PyFileIO_closed(PyObject *self)
 static PyObject *
 fileio_dealloc_warn(PyObject *op, PyObject *source)
 {
-    fileio *self = _PyFileIO_CAST(op);
+    fileio *self = PyFileIO_CAST(op);
     if (self->fd >= 0 && self->closefd) {
         PyObject *exc = PyErr_GetRaisedException();
         if (PyErr_ResourceWarning(source, 1, "unclosed file %R", source)) {
@@ -542,7 +542,7 @@ _io_FileIO___init___impl(fileio *self, PyObject *nameobj, const char *mode,
 static int
 fileio_traverse(PyObject *op, visitproc visit, void *arg)
 {
-    fileio *self = _PyFileIO_CAST(op);
+    fileio *self = PyFileIO_CAST(op);
     Py_VISIT(Py_TYPE(self));
     Py_VISIT(self->dict);
     return 0;
@@ -551,7 +551,7 @@ fileio_traverse(PyObject *op, visitproc visit, void *arg)
 static int
 fileio_clear(PyObject *op)
 {
-    fileio *self = _PyFileIO_CAST(op);
+    fileio *self = PyFileIO_CAST(op);
     Py_CLEAR(self->dict);
     return 0;
 }
@@ -559,7 +559,7 @@ fileio_clear(PyObject *op)
 static void
 fileio_dealloc(PyObject *op)
 {
-    fileio *self = _PyFileIO_CAST(op);
+    fileio *self = PyFileIO_CAST(op);
     self->finalizing = 1;
     if (_PyIOBase_finalize(op) < 0) {
         return;
@@ -1161,7 +1161,7 @@ mode_string(fileio *self)
 static PyObject *
 fileio_repr(PyObject *op)
 {
-    fileio *self = _PyFileIO_CAST(op);
+    fileio *self = PyFileIO_CAST(op);
     const char *type_name = Py_TYPE(self)->tp_name;
 
     if (self->fd < 0) {
@@ -1229,7 +1229,7 @@ _io_FileIO_isatty_impl(fileio *self)
 static PyObject *
 _io_FileIO_isatty_open_only(PyObject *op, PyObject *Py_UNUSED(dummy))
 {
-    fileio *self = _PyFileIO_CAST(op);
+    fileio *self = PyFileIO_CAST(op);
     if (self->stat_atopen != NULL && !S_ISCHR(self->stat_atopen->st_mode)) {
         Py_RETURN_FALSE;
     }
@@ -1264,28 +1264,28 @@ static PyMethodDef fileio_methods[] = {
 static PyObject *
 fileio_get_closed(PyObject *op, void *closure)
 {
-    fileio *self = _PyFileIO_CAST(op);
+    fileio *self = PyFileIO_CAST(op);
     return PyBool_FromLong((long)(self->fd < 0));
 }
 
 static PyObject *
 fileio_get_closefd(PyObject *op, void *closure)
 {
-    fileio *self = _PyFileIO_CAST(op);
+    fileio *self = PyFileIO_CAST(op);
     return PyBool_FromLong((long)(self->closefd));
 }
 
 static PyObject *
 fileio_get_mode(PyObject *op, void *closure)
 {
-    fileio *self = _PyFileIO_CAST(op);
+    fileio *self = PyFileIO_CAST(op);
     return PyUnicode_FromString(mode_string(self));
 }
 
 static PyObject *
 fileio_get_blksize(PyObject *op, void *closure)
 {
-    fileio *self = _PyFileIO_CAST(op);
+    fileio *self = PyFileIO_CAST(op);
 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
     if (self->stat_atopen != NULL && self->stat_atopen->st_blksize > 1) {
         return PyLong_FromLong(self->stat_atopen->st_blksize);