Python: Add getAReturnedNode to PythonFunctionValue

python/ql/src/semmle/python/objects/ObjectAPI.qll

@@ -211,7 +211,7 @@ module Value {
     }
 
     /** Gets the `Value` for the integer constant `i`, if it exists.
-     * There will be no `Value` for most integers, but the following are 
+     * There will be no `Value` for most integers, but the following are
      * guaranteed to exist:
      * * From zero to 511 inclusive.
      * * All powers of 2 (up to 2**30)
@@ -486,6 +486,11 @@ class PythonFunctionValue extends FunctionValue {
         )
     }
 
+    /** Gets a control flow node corresponding to a return statement in this function */
+    ControlFlowNode getAReturnedNode() {
+        result = this.getScope().getAReturnValueFlowNode()
+    }
+
 }
 
 /** Class representing builtin functions, such as `len` or `print` */

python/ql/src/semmle/python/web/flask/Response.qll

@@ -9,8 +9,8 @@ import semmle.python.web.flask.General
  */
 class FlaskRoutedResponse extends HttpResponseTaintSink {
     FlaskRoutedResponse() {
-        exists(PyFunctionObject response |
-            flask_routing(_, response.getFunction()) and
+        exists(PythonFunctionValue response |
+            flask_routing(_, response.getScope()) and
             this = response.getAReturnedNode()
         )
     }

python/ql/src/semmle/python/web/pyramid/Response.qll

@@ -11,8 +11,8 @@ private import semmle.python.web.Http
  */
 class PyramidRoutedResponse extends HttpResponseTaintSink {
     PyramidRoutedResponse() {
-        exists(PyFunctionObject view |
-            is_pyramid_view_function(view.getFunction()) and
+        exists(PythonFunctionValue view |
+            is_pyramid_view_function(view.getScope()) and
             this = view.getAReturnedNode()
         )
     }

python/ql/src/semmle/python/web/twisted/Response.qll

@@ -11,8 +11,7 @@ class TwistedResponse extends TaintSink {
             isKnownRequestHandlerMethodName(name) and
             name = func.getName() and
             func = getTwistedRequestHandlerMethod(name) and
-            func.getScope() = ret.getScope() and
-            ret.getValue().getAFlowNode() = this
+            this = func.getAReturnedNode()
         )
     }