bpo-41103: Remove old buffer protocol support (#21117)

They are deprecated since Python 3.0.

Author: methane

Doc/c-api/abstract.rst

@@ -24,4 +24,3 @@ but whose items have not been set to some non-\ ``NULL`` value yet.
    mapping.rst
    iter.rst
    buffer.rst
-   objbuffer.rst

Doc/c-api/objbuffer.rst

@@ -1568,21 +1568,6 @@ PyOS_FSPath:PyObject*:path:0:
 PyObject_ASCII:PyObject*::+1:
 PyObject_ASCII:PyObject*:o:0:
 
-PyObject_AsCharBuffer:int:::
-PyObject_AsCharBuffer:PyObject*:obj:0:
-PyObject_AsCharBuffer:const char**:buffer::
-PyObject_AsCharBuffer:Py_ssize_t*:buffer_len::
-
-PyObject_AsReadBuffer:int:::
-PyObject_AsReadBuffer:PyObject*:obj:0:
-PyObject_AsReadBuffer:const void**:buffer::
-PyObject_AsReadBuffer:Py_ssize_t*:buffer_len::
-
-PyObject_AsWriteBuffer:int:::
-PyObject_AsWriteBuffer:PyObject*:obj:0:
-PyObject_AsWriteBuffer:void**:buffer::
-PyObject_AsWriteBuffer:Py_ssize_t*:buffer_len::
-
 PyObject_Bytes:PyObject*::+1:
 PyObject_Bytes:PyObject*:o:0:
 
@@ -1618,9 +1603,6 @@ PyObject_CallObject:PyObject*:args:0:
 PyObject_CheckBuffer:int:::
 PyObject_CheckBuffer:PyObject*:obj:0:
 
-PyObject_CheckReadBuffer:int:::
-PyObject_CheckReadBuffer:PyObject*:o:0:
-
 PyObject_DelAttr:int:::
 PyObject_DelAttr:PyObject*:o:0:
 PyObject_DelAttr:PyObject*:attr_name:0:

Doc/data/refcounts.dat

@@ -204,3 +204,8 @@ Porting to Python 3.10
 
 Removed
 -------
+
+* ``PyObject_AsCharBuffer()``, ``PyObject_AsReadBuffer()``, ``PyObject_CheckReadBuffer()``,
+  and ``PyObject_AsWriteBuffer()`` are removed. Please migrate to new buffer protocol;
+  :c:func:`PyObject_GetBuffer` and :c:func:`PyBuffer_Release`.
+  (Contributed by Inada Naoki in :issue:`41103`.

Doc/whatsnew/3.10.rst

@@ -309,53 +309,6 @@ PyAPI_FUNC(int) PyObject_DelItemString(PyObject *o, const char *key);
 PyAPI_FUNC(int) PyObject_DelItem(PyObject *o, PyObject *key);
 
 
-/* === Old Buffer API ============================================ */
-
-/* FIXME:  usage of these should all be replaced in Python itself
-   but for backwards compatibility we will implement them.
-   Their usage without a corresponding "unlock" mechanism
-   may create issues (but they would already be there). */
-
-/* Takes an arbitrary object which must support the (character, single segment)
-   buffer interface and returns a pointer to a read-only memory location
-   useable as character based input for subsequent processing.
-
-   Return 0 on success.  buffer and buffer_len are only set in case no error
-   occurs. Otherwise, -1 is returned and an exception set. */
-Py_DEPRECATED(3.0)
-PyAPI_FUNC(int) PyObject_AsCharBuffer(PyObject *obj,
-                                      const char **buffer,
-                                      Py_ssize_t *buffer_len);
-
-/* Checks whether an arbitrary object supports the (character, single segment)
-   buffer interface.
-
-   Returns 1 on success, 0 on failure. */
-Py_DEPRECATED(3.0) PyAPI_FUNC(int) PyObject_CheckReadBuffer(PyObject *obj);
-
-/* Same as PyObject_AsCharBuffer() except that this API expects (readable,
-   single segment) buffer interface and returns a pointer to a read-only memory
-   location which can contain arbitrary data.
-
-   0 is returned on success.  buffer and buffer_len are only set in case no
-   error occurs.  Otherwise, -1 is returned and an exception set. */
-Py_DEPRECATED(3.0)
-PyAPI_FUNC(int) PyObject_AsReadBuffer(PyObject *obj,
-                                      const void **buffer,
-                                      Py_ssize_t *buffer_len);
-
-/* Takes an arbitrary object which must support the (writable, single segment)
-   buffer interface and returns a pointer to a writable memory location in
-   buffer of size 'buffer_len'.
-
-   Return 0 on success.  buffer and buffer_len are only set in case no error
-   occurs. Otherwise, -1 is returned and an exception set. */
-Py_DEPRECATED(3.0)
-PyAPI_FUNC(int) PyObject_AsWriteBuffer(PyObject *obj,
-                                       void **buffer,
-                                       Py_ssize_t *buffer_len);
-
-
 /* === New Buffer API ============================================ */
 
 /* Takes an arbitrary object and returns the result of calling

Include/abstract.h

@@ -0,0 +1,4 @@
+``PyObject_AsCharBuffer()``, ``PyObject_AsReadBuffer()``,
+``PyObject_CheckReadBuffer()``, and ``PyObject_AsWriteBuffer()`` are
+removed. Please migrate to new buffer protocol; :c:func:`PyObject_GetBuffer`
+and :c:func:`PyBuffer_Release`.

Misc/NEWS.d/next/C API/2020-06-24-22-57-07.bpo-41103.doojgE.rst

@@ -292,85 +292,6 @@ PyObject_CheckBuffer(PyObject *obj)
 }
 
 
-/* We release the buffer right after use of this function which could
-   cause issues later on.  Don't use these functions in new code.
- */
-int
-PyObject_CheckReadBuffer(PyObject *obj)
-{
-    PyBufferProcs *pb = Py_TYPE(obj)->tp_as_buffer;
-    Py_buffer view;
-
-    if (pb == NULL ||
-        pb->bf_getbuffer == NULL)
-        return 0;
-    if ((*pb->bf_getbuffer)(obj, &view, PyBUF_SIMPLE) == -1) {
-        PyErr_Clear();
-        return 0;
-    }
-    PyBuffer_Release(&view);
-    return 1;
-}
-
-static int
-as_read_buffer(PyObject *obj, const void **buffer, Py_ssize_t *buffer_len)
-{
-    Py_buffer view;
-
-    if (obj == NULL || buffer == NULL || buffer_len == NULL) {
-        null_error();
-        return -1;
-    }
-    if (PyObject_GetBuffer(obj, &view, PyBUF_SIMPLE) != 0)
-        return -1;
-
-    *buffer = view.buf;
-    *buffer_len = view.len;
-    PyBuffer_Release(&view);
-    return 0;
-}
-
-int
-PyObject_AsCharBuffer(PyObject *obj,
-                      const char **buffer,
-                      Py_ssize_t *buffer_len)
-{
-    return as_read_buffer(obj, (const void **)buffer, buffer_len);
-}
-
-int PyObject_AsReadBuffer(PyObject *obj,
-                          const void **buffer,
-                          Py_ssize_t *buffer_len)
-{
-    return as_read_buffer(obj, buffer, buffer_len);
-}
-
-int PyObject_AsWriteBuffer(PyObject *obj,
-                           void **buffer,
-                           Py_ssize_t *buffer_len)
-{
-    PyBufferProcs *pb;
-    Py_buffer view;
-
-    if (obj == NULL || buffer == NULL || buffer_len == NULL) {
-        null_error();
-        return -1;
-    }
-    pb = Py_TYPE(obj)->tp_as_buffer;
-    if (pb == NULL ||
-        pb->bf_getbuffer == NULL ||
-        ((*pb->bf_getbuffer)(obj, &view, PyBUF_WRITABLE) != 0)) {
-        PyErr_SetString(PyExc_TypeError,
-                        "expected a writable bytes-like object");
-        return -1;
-    }
-
-    *buffer = view.buf;
-    *buffer_len = view.len;
-    PyBuffer_Release(&view);
-    return 0;
-}
-
 /* Buffer C-API for Python 3.0 */
 
 int

Objects/abstract.c

@@ -392,11 +392,8 @@ EXPORT_FUNC(PyNumber_Subtract)
 EXPORT_FUNC(PyNumber_ToBase)
 EXPORT_FUNC(PyNumber_TrueDivide)
 EXPORT_FUNC(PyNumber_Xor)
-EXPORT_FUNC(PyObject_AsCharBuffer)
 EXPORT_FUNC(PyObject_ASCII)
 EXPORT_FUNC(PyObject_AsFileDescriptor)
-EXPORT_FUNC(PyObject_AsReadBuffer)
-EXPORT_FUNC(PyObject_AsWriteBuffer)
 EXPORT_FUNC(PyObject_Bytes)
 EXPORT_FUNC(PyObject_Call)
 EXPORT_FUNC(PyObject_CallFunction)
@@ -405,7 +402,6 @@ EXPORT_FUNC(PyObject_CallMethod)
 EXPORT_FUNC(PyObject_CallMethodObjArgs)
 EXPORT_FUNC(PyObject_CallObject)
 EXPORT_FUNC(PyObject_Calloc)
-EXPORT_FUNC(PyObject_CheckReadBuffer)
 EXPORT_FUNC(PyObject_ClearWeakRefs)
 EXPORT_FUNC(PyObject_DelItem)
 EXPORT_FUNC(PyObject_DelItemString)