Code review of the new buffer protocol. Mostly add questions that should

be answered with the comments removed.

There are many places that require checks when doing arithmetic for memory
sizes when allocating memory.  Otherwise, overflow is possible with
a subsequent crash.

Fix SF #1777057 which was a result of not initializing the new BufferError
properly.  Had to update the test for exceptions for BufferError too.

1 files changed, 13 insertions, 16 deletions

diff --git a/Objects/memoryobject.c b/Objects/memoryobject.c
index efcb7aeb19..27fb9695e9 100644
--- a/Objects/memoryobject.c
+++ b/Objects/memoryobject.c
@@ -26,6 +26,7 @@ Create a new memoryview object which references the given object.");
 PyObject *
 PyMemoryView_FromMemory(PyBuffer *info)
 {
+	/* XXX(nnorwitz): need to implement something here? */
         return NULL;
 }
 
@@ -59,7 +60,7 @@ static PyObject *
 memory_new(PyTypeObject *subtype, PyObject *args, PyObject *kwds)
 {
         PyObject *obj;
-        if (!PyArg_ParseTuple(args, "O", &obj)) return NULL;
+        if (!PyArg_UnpackTuple(args, "memoryview", 1, 1, &obj)) return NULL;
 
         return PyMemoryView_FromObject(obj);        
 }
@@ -136,6 +137,7 @@ _indirect_copy_nd(char *dest, PyBuffer *view, char fort)
         void (*func)(int, Py_ssize_t *, Py_ssize_t *);
         
         
+        /* XXX(nnorwitz): need to check for overflow! */
         indices = (Py_ssize_t *)PyMem_Malloc(sizeof(Py_ssize_t)*view->ndim);
         if (indices == NULL) {
                 PyErr_NoMemory();
@@ -260,6 +262,7 @@ PyMemoryView_GetContiguous(PyObject *obj, int buffertype, char fort)
                 /* return a shadowed memory-view object */
                 view->buf = dest;
                 mem->base = PyTuple_Pack(2, obj, bytes);
+		/* XXX(nnorwitz): need to verify alloc was successful. */
                 Py_DECREF(bytes);
         }
         else {
@@ -373,17 +376,15 @@ static PyGetSetDef memory_getsetlist[] ={
 
 
 static PyObject *
-memory_tobytes(PyMemoryViewObject *mem, PyObject *args)
+memory_tobytes(PyMemoryViewObject *mem, PyObject *noargs)
 {
-        if (!PyArg_ParseTuple(args, "")) return NULL;
         /* Create new Bytes object for data */
         return PyBytes_FromObject((PyObject *)mem);
 }
 
 static PyObject *
-memory_tolist(PyMemoryViewObject *mem, PyObject *args)
+memory_tolist(PyMemoryViewObject *mem, PyObject *noargs)
 {
-        if (!PyArg_ParseTuple(args, "")) return NULL;        
         Py_INCREF(Py_NotImplemented);
         return Py_NotImplemented;
 }
@@ -391,8 +392,8 @@ memory_tolist(PyMemoryViewObject *mem, PyObject *args)
 
 
 static PyMethodDef memory_methods[] = {
-        {"tobytes", (PyCFunction)memory_tobytes, 1, NULL},
-        {"tolist", (PyCFunction)memory_tolist, 1, NULL},
+        {"tobytes", (PyCFunction)memory_tobytes, METH_NOARGS, NULL},
+        {"tolist", (PyCFunction)memory_tolist, METH_NOARGS, NULL},
         {NULL,          NULL}           /* sentinel */
 };
 
@@ -400,7 +401,6 @@ static PyMethodDef memory_methods[] = {
 static void
 memory_dealloc(PyMemoryViewObject *self)
 {
-
         if (PyTuple_Check(self->base)) {
                 /* Special case when first element is generic object
                    with buffer interface and the second element is a
@@ -423,21 +423,18 @@ memory_dealloc(PyMemoryViewObject *self)
         else {
                 PyObject_ReleaseBuffer(self->base, &(self->view));
         }
-        Py_DECREF(self->base);
+        Py_CLEAR(self->base);
         PyObject_DEL(self);
 }
 
 static PyObject *
 memory_repr(PyMemoryViewObject *self)
 {
-
-	if ( self->base == NULL )
-		return PyUnicode_FromFormat("<memory at %p>",
-					   self);
+	/* XXX(nnorwitz): the code should be different or remove condition. */
+	if (self->base == NULL)
+		return PyUnicode_FromFormat("<memory at %p>", self);
 	else
-		return PyUnicode_FromFormat(
-			"<memory at %p>",
-			self);
+		return PyUnicode_FromFormat("<memory at %p>", self);
 }