Annotate SWIG aa_log_record alloc+dealloc

Swig generates a "thisown" attribute, which is an escape hatch in case
higher-level code does something weird and needs to tell SWIG whether to
free the C object when Python garbage collects it. Adding this attribute
is not a breaking change w.r.t access to the other attributes of the parsed
record.

Signed-off-by: Ryan Lee <ryan.lee@canonical.com>

libraries/libapparmor/swig/SWIG/libapparmor.i

@@ -8,6 +8,26 @@
 %}
 
 %include "typemaps.i"
+
+%newobject parse_record;
+%delobject free_record;
+/*
+ * Despite its name, %delobject does not hook up destructors to language
+ * deletion mechanisms. Instead, it sets flags so that manually calling the
+ * free function and then deleting by language mechanisms doesn't cause a
+ * double-free. (Manually calling the free function twice can still cause a
+ * double-free.)
+ *
+ * Instead, we need manually extend the struct with a C++-like destructor.
+ * This ensures that the record struct is free when the high-level object
+ * goes out of scope.
+ */
+%extend aa_log_record {
+	~aa_log_record() {
+		free_record($self);
+	}
+}
+
 %include <aalogparse.h>
 
 /**

libraries/libapparmor/swig/python/test/test_python.py.in

@@ -118,6 +118,9 @@ class AAPythonBindingsTests(unittest.TestCase):
                 # FIXME: out files should report log version?
                 # FIXME: or can we just deprecate v1 logs?
                 continue
+            elif key == "thisown":
+                # SWIG generates this key to track memory allocation
+                continue
             elif key in NO_VALUE_MAP:
                 if NO_VALUE_MAP[key] == value:
                     continue