Add test for attribute points-to extension.

Author: markshannon

python/ql/test/library-tests/PointsTo/extensions/Extend.expected

@@ -5,3 +5,11 @@
 | test.py:8:3:8:3 | ControlFlowNode for IntegerLiteral | int 2 |
 | test.py:8:5:8:5 | ControlFlowNode for IntegerLiteral | int 3 |
 | test.py:8:7:8:7 | ControlFlowNode for IntegerLiteral | int 4 |
+| test.py:10:1:10:2 | ControlFlowNode for a3 | int 3 |
+| test.py:10:6:10:7 | ControlFlowNode for Str | str u'' |
+| test.py:10:6:10:13 | ControlFlowNode for Attribute | int 3 |
+| test.py:11:1:11:2 | ControlFlowNode for a4 | int 4 |
+| test.py:11:6:11:10 | ControlFlowNode for False | bool False |
+| test.py:11:6:11:15 | ControlFlowNode for Attribute | int 4 |
+| test.py:13:1:13:2 | ControlFlowNode for a3 | int 3 |
+| test.py:14:1:14:2 | ControlFlowNode for a4 | int 4 |

python/ql/test/library-tests/PointsTo/extensions/Extend.ql

@@ -5,7 +5,7 @@ import python
 private import semmle.python.types.Extensions
 
 
-class CfgExtension  extends CustomPointsToOriginFact {
+class CfgExtension extends CustomPointsToOriginFact {
 
     CfgExtension() {
         this.(NameNode).getId() = "one"
@@ -23,6 +23,21 @@ class CfgExtension  extends CustomPointsToOriginFact {
     }
 }
 
+class AttributeExtension  extends CustomPointsToAttribute {
+
+    AttributeExtension() { any() }
+
+    override predicate attributePointsTo(string name, Object value, ClassObject cls, ControlFlowNode origin) {
+        cls = theIntType() and origin = any(Module m).getEntryNode() and
+        (
+            name = "three" and value.(NumericObject).intValue() = 3
+            or
+            name = "four" and value.(NumericObject).intValue() = 4
+        )
+    }
+
+}
+
 from ControlFlowNode f, Object o
 where f.getLocation().getFile().getBaseName() = "test.py" and f.refersTo(o)
 select f, o.toString()

python/ql/test/library-tests/PointsTo/extensions/test.py

@@ -6,3 +6,9 @@
 
 #Make sure values exist in DB
 1,2,3,4
+
+a3 = "".three
+a4 = False.four
+
+a3
+a4