bpo-39573: Convert Py_REFCNT and Py_SIZE to functions (GH-20429)
Convert Py_REFCNT() and Py_SIZE() macros to static inline functions.
They cannot be used as l-value anymore: use Py_SET_REFCNT() and
Py_SET_SIZE() to set an object reference count and size.
Replace &Py_SIZE(self) with &((PyVarObject*)self)->ob_size
in arraymodule.c.
This change is backward incompatible on purpose, to prepare the C API
for an opaque PyObject structure.
diff --git a/Doc/c-api/structures.rst b/Doc/c-api/structures.rst
index 5535f42..b2392fa 100644
--- a/Doc/c-api/structures.rst
+++ b/Doc/c-api/structures.rst
@@ -88,13 +88,13 @@
.. versionadded:: 3.9
-.. c:macro:: Py_REFCNT(o)
+.. c:function:: Py_ssize_t Py_REFCNT(const PyObject *o)
- This macro is used to access the :attr:`ob_refcnt` member of a Python
- object.
- It expands to::
+ Get the reference count of the Python object *o*.
- (((PyObject*)(o))->ob_refcnt)
+ .. versionchanged:: 3.10
+ :c:func:`Py_REFCNT()` is changed to the inline static function.
+ Use :c:func:`Py_SET_REFCNT()` to set an object reference count.
.. c:function:: void Py_SET_REFCNT(PyObject *o, Py_ssize_t refcnt)
@@ -104,12 +104,13 @@
.. versionadded:: 3.9
-.. c:macro:: Py_SIZE(o)
+.. c:function:: Py_ssize_t Py_SIZE(const PyVarObject *o)
- This macro is used to access the :attr:`ob_size` member of a Python object.
- It expands to::
+ Get the size of the Python object *o*.
- (((PyVarObject*)(o))->ob_size)
+ .. versionchanged:: 3.10
+ :c:func:`Py_SIZE()` is changed to the inline static function.
+ Use :c:func:`Py_SET_SIZE()` to set an object size.
.. c:function:: void Py_SET_SIZE(PyVarObject *o, Py_ssize_t size)
diff --git a/Doc/whatsnew/3.10.rst b/Doc/whatsnew/3.10.rst
index fabd9a2..9edef1e 100644
--- a/Doc/whatsnew/3.10.rst
+++ b/Doc/whatsnew/3.10.rst
@@ -138,6 +138,15 @@
see :c:func:`Py_SET_TYPE()` (available since Python 3.9).
(Contributed by Dong-hee Na in :issue:`39573`.)
+* Since :c:func:`Py_REFCNT()` is changed to the inline static function,
+ ``Py_REFCNT(obj) = new_refcnt`` must be replaced with ``Py_SET_REFCNT(obj, new_refcnt)``:
+ see :c:func:`Py_SET_REFCNT()` (available since Python 3.9).
+ (Contributed by Victor Stinner in :issue:`39573`.)
+
+* Since :c:func:`Py_SIZE()` is changed to the inline static function,
+ ``Py_SIZE(obj) = new_size`` must be replaced with ``Py_SET_SIZE(obj, new_size)``:
+ see :c:func:`Py_SET_SIZE()` (available since Python 3.9).
+ (Contributed by Victor Stinner in :issue:`39573`.)
Removed
-------
diff --git a/Include/object.h b/Include/object.h
index 5ad0569..5375670 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -119,30 +119,45 @@
/* Cast argument to PyVarObject* type. */
#define _PyVarObject_CAST(op) ((PyVarObject*)(op))
+#define _PyVarObject_CAST_CONST(op) ((const PyVarObject*)(op))
-#define Py_REFCNT(ob) (_PyObject_CAST(ob)->ob_refcnt)
-#define Py_SIZE(ob) (_PyVarObject_CAST(ob)->ob_size)
+
+static inline Py_ssize_t _Py_REFCNT(const PyObject *ob) {
+ return ob->ob_refcnt;
+}
+#define Py_REFCNT(ob) _Py_REFCNT(_PyObject_CAST_CONST(ob))
+
+
+static inline Py_ssize_t _Py_SIZE(const PyVarObject *ob) {
+ return ob->ob_size;
+}
+#define Py_SIZE(ob) _Py_SIZE(_PyVarObject_CAST_CONST(ob))
+
static inline PyTypeObject* _Py_TYPE(const PyObject *ob) {
return ob->ob_type;
}
#define Py_TYPE(ob) _Py_TYPE(_PyObject_CAST_CONST(ob))
+
static inline int _Py_IS_TYPE(const PyObject *ob, const PyTypeObject *type) {
return ob->ob_type == type;
}
#define Py_IS_TYPE(ob, type) _Py_IS_TYPE(_PyObject_CAST_CONST(ob), type)
+
static inline void _Py_SET_REFCNT(PyObject *ob, Py_ssize_t refcnt) {
ob->ob_refcnt = refcnt;
}
#define Py_SET_REFCNT(ob, refcnt) _Py_SET_REFCNT(_PyObject_CAST(ob), refcnt)
+
static inline void _Py_SET_TYPE(PyObject *ob, PyTypeObject *type) {
ob->ob_type = type;
}
#define Py_SET_TYPE(ob, type) _Py_SET_TYPE(_PyObject_CAST(ob), type)
+
static inline void _Py_SET_SIZE(PyVarObject *ob, Py_ssize_t size) {
ob->ob_size = size;
}
diff --git a/Misc/NEWS.d/next/C API/2020-05-26-16-21-47.bpo-39573.depAgq.rst b/Misc/NEWS.d/next/C API/2020-05-26-16-21-47.bpo-39573.depAgq.rst
new file mode 100644
index 0000000..f8f675c
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2020-05-26-16-21-47.bpo-39573.depAgq.rst
@@ -0,0 +1,5 @@
+Convert :c:func:`Py_REFCNT` and :c:func:`Py_SIZE` macros to static inline
+functions. They cannot be used as l-value anymore: use
+:c:func:`Py_SET_REFCNT` and :c:func:`Py_SET_SIZE` to set an object reference
+count and size. This change is backward incompatible on purpose, to prepare
+the C API for an opaque :c:type:`PyObject` structure.
diff --git a/Modules/arraymodule.c b/Modules/arraymodule.c
index fb1b82c..4c3ddc3 100644
--- a/Modules/arraymodule.c
+++ b/Modules/arraymodule.c
@@ -2525,14 +2525,14 @@
Py_INCREF(self);
if (view->buf == NULL)
view->buf = (void *)emptybuf;
- view->len = (Py_SIZE(self)) * self->ob_descr->itemsize;
+ view->len = Py_SIZE(self) * self->ob_descr->itemsize;
view->readonly = 0;
view->ndim = 1;
view->itemsize = self->ob_descr->itemsize;
view->suboffsets = NULL;
view->shape = NULL;
if ((flags & PyBUF_ND)==PyBUF_ND) {
- view->shape = &((Py_SIZE(self)));
+ view->shape = &((PyVarObject*)self)->ob_size;
}
view->strides = NULL;
if ((flags & PyBUF_STRIDES)==PyBUF_STRIDES)
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index e4c0c91..43706c2 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -82,7 +82,7 @@
numfree[size]--;
/* Inline PyObject_InitVar */
#ifdef Py_TRACE_REFS
- Py_SIZE(op) = size;
+ Py_SET_SIZE(op, size);
Py_SET_TYPE(op, &PyTuple_Type);
#endif
_Py_NewReference((PyObject *)op);