Secure code.

theano/gof/op.py

@@ -801,13 +801,14 @@ class Op(utils.object2, PureOp, CLinkerOp):
     def get_params(self, node):
         if hasattr(self, 'params_type') and isinstance(self.params_type, theano.gof.Wrapper):
             wrapper = self.params_type
-            if all(hasattr(self, field) for field in wrapper.fields):
-                wrap_dict = dict()
-                for i in range(wrapper.length):
-                    field = wrapper.fields[i]
-                    _type = wrapper.types[i]
-                    wrap_dict[field] = _type.filter(getattr(self, field), strict=False, allow_downcast=True)
-                return theano.gof.Wrap(wrapper, **wrap_dict)
+            if not all(hasattr(self, field) for field in wrapper.fields):
+                raise AttributeError('%s: missing attributes for Wrapper parameter.' % type(self).__name__)
+            wrap_dict = dict()
+            for i in range(wrapper.length):
+                field = wrapper.fields[i]
+                _type = wrapper.types[i]
+                wrap_dict[field] = _type.filter(getattr(self, field), strict=False, allow_downcast=True)
+            return theano.gof.Wrap(wrapper, **wrap_dict)
         raise theano.gof.utils.MethodNotDefined('get_params')
 
     def prepare_node(self, node, storage_map, compute_map, impl):

theano/gof/wrapper.py

@@ -101,7 +101,7 @@ class Wrap(dict):
             if field not in kwargs:
                 raise TypeError('Wrap: Wrapper attribute "%s" not in Wrap args.' % field)
         super(Wrap, self).__init__(**kwargs)
-        self.__dict__.update(wrapper=wrapper)
+        self.__dict__.update(wrapper=wrapper, signatures=None)
 
     def __repr__(self):
         return 'Wrap(%s)' % ', '.join([('%s:%s' % (k, type(self[k]))) for k in sorted(self.keys())])
@@ -121,11 +121,15 @@ class Wrap(dict):
         raise NotImplementedError('Wrap is immutable')
 
     def __hash__(self):
-        return hash((type(self), self.wrapper) + tuple(
-            # NB: Wrapped data should have been already filtered.
-            self.wrapper.types[i].make_constant(self[self.wrapper.fields[i]]).signature()
-            for i in range(self.wrapper.length)
-        ))
+        # As values are immutable, we can save data signatures the first time
+        # to not regenerate them in future hash() calls.
+        if self.__dict__['signatures'] is None:
+            self.__dict__['signatures'] = tuple(
+                # NB: Wrapped data should have been already filtered.
+                self.wrapper.types[i].make_constant(self[self.wrapper.fields[i]]).signature()
+                for i in range(self.wrapper.length)
+            )
+        return hash((type(self), self.wrapper) + self.signatures)
 
     def __eq__(self, other):
         return (type(self) == type(other) and self.wrapper == other.wrapper and all(
@@ -210,7 +214,7 @@ class Wrapper(Type):
         wrap_instance = dict()
         for i in range(self.length):
             wrap_instance[self.fields[i]] = self.types[i].filter(getattr(data, self.fields[i]), strict, allow_downcast)
-        return data if strict else Wrap(self, **wrap_instance)
+        return data if (strict or isinstance(data, Wrap)) else Wrap(self, **wrap_instance)
 
     # Returns a wrapped object with expected attributes or (in strict mode) checks that data has expected attributes.
     def filter(self, data, strict=False, allow_downcast=None):