Initial commit of Python queries and QL libraries.

python/ql/src/analysis/CallGraphMarginalEfficiency.ql

@@ -0,0 +1,29 @@
+/** Compute the marginal increase call-graph facts, the total size of the call-graph relation and 
+ * the ratio of the two in relation to the depth of context.
+ */
+
+import python
+import semmle.python.pointsto.PointsTo
+import semmle.python.pointsto.PointsToContext
+
+from int total_facts, int total_size, int depth, float efficiency
+where 
+total_facts = strictcount(ControlFlowNode call, FunctionObject func |
+    exists(PointsToContext ctx |
+        call = PointsTo::get_a_call(func, ctx) and
+        depth = ctx.getDepth()
+        and not
+        exists(PointsToContext shallower |
+            call = PointsTo::get_a_call(func, shallower) and
+            shallower.getDepth() < depth
+        )
+    )
+)
+and
+total_size = strictcount(ControlFlowNode call, FunctionObject func, PointsToContext ctx |
+    call = PointsTo::get_a_call(func, ctx) and
+    depth = ctx.getDepth()
+)
+and
+efficiency = 100.0 * total_facts / total_size
+select depth, total_facts, total_size, efficiency