Fix memory leaks in enum.cpp

elmopl · stefanseefeld · commit 2b7842a39f02 · 2017-10-25T08:04:35.000-04:00
Unfortunately due to optimised build of Python3 libraries and executable I got only partial stack from [http://clang.llvm.org/docs/AddressSanitizer.html], however digging into and reducing my code I tracked it down to be issue with `boost/libs/python/src/object/enum.cpp`. It has to bits that leak (and comment mentioning there is one): PyObject *mod = PyObject_GetAttrString( self_, "__module__"); Leaks reference, as it never decreases it. It also stores a new string object under object's `name` that ref count never gets decremented. That commit fixes both issues.
diff --git a/src/object/enum.cpp b/src/object/enum.cpp
@@ -34,11 +34,17 @@ static PyMemberDef enum_members[] = {
 
 extern "C"
 {
+    static void
+    enum_dealloc(enum_object* self)
+    {
+        Py_XDECREF(self->name);
+        Py_TYPE(self)->tp_free((PyObject*)self);
+    }
+
     static PyObject* enum_repr(PyObject* self_)
     {
-        // XXX(bhy) Potentional memory leak here since PyObject_GetAttrString returns a new reference
-        // const char *mod = PyString_AsString(PyObject_GetAttrString( self_, const_cast<char*>("__module__")));
         PyObject *mod = PyObject_GetAttrString( self_, "__module__");
+        object auto_free(handle<>(mod));
         enum_object* self = downcast<enum_object>(self_);
         if (!self->name)
         {
@@ -88,7 +94,7 @@ static PyTypeObject enum_type_object = {
     const_cast<char*>("Boost.Python.enum"),
     sizeof(enum_object),                    /* tp_basicsize */
     0,                                      /* tp_itemsize */
-    0,                                      /* tp_dealloc */
+    (destructor) enum_dealloc,              /* tp_dealloc */
     0,                                      /* tp_print */
     0,                                      /* tp_getattr */
     0,                                      /* tp_setattr */
