/**
 * @name Static slicing
 * @description An attempt to perform a static slice
 * @id cs/static-slicing
 * @problem.severity error
 * @precision very-high
 * @tags security
 * @kind path-problem
 */
import csharp
import semmle.code.csharp.security.dataflow.flowsources.Remote
import semmle.code.csharp.commons.Util
import semmle.code.csharp.dataflow.DataFlow::DataFlow::PathGraph
import semmle.code.csharp.controlflow.Guards
import semmle.code.csharp.controlflow.BasicBlocks
import semmle.code.csharp.ExprOrStmtParent
class TaintTrackingConfiguration extends TaintTracking::Configuration {
 TaintTrackingConfiguration() { this = "CustomSlice" }
 override predicate isSource(DataFlow::Node source) {
 any()
 }
 override predicate isSink(DataFlow::Node sink) {
 sink.asExpr().getLocation().getFile().getAbsolutePath().indexOf("Program.cs") > 0
	 and sink.asExpr().getLocation().getStartLine() = 12 // Target of the slicer (catching the variable result)
 }
 // An attempt to add the control dependencies
 override predicate isAdditionalTaintStep(DataFlow::Node pred, DataFlow::Node succ) {
 exists (Guard g, BasicBlock b, AbstractValue v | 
 g.getAControlFlowNode() = pred.getControlFlowNode() and
 b.getANode() = succ.getControlFlowNode() and
 g.controlsBasicBlock(b, v)
 )
 }
}
from TaintTrackingConfiguration c, DataFlow::PathNode source, DataFlow::PathNode sink
where c.hasFlowPath(source, sink)
select sink.getNode(), source, sink, "Msg", source.getNode(), "Msg"

using System;
namespace example2
{
	public class Program
	{
		public static void Main(string[] args)
		{
			int levels = 5;
			TreeNode root = new TreeNode(levels);
			int result = root.addTree(); // *
			var slicingVariable1 = result; // *
			System.Console.WriteLine("Done!");
		}
	}
	internal class TreeNode
	{
		private int value = 0;
		private TreeNode left = null;
		private TreeNode right = null;
		internal TreeNode(int levels)
		{
			value = 1;
			if (levels <= 1)
			{
				if (levels <= 0)
					throw new System.Exception("Number of levels must be positive no.");
				left = null;
				right = null;
			}
			else
			{
				left = new TreeNode(levels - 1);
				right = new TreeNode(levels - 1);
			}
		}
		internal virtual int addTree()
		{
			int total = value; // *
			if (left != null) // *
				total += left.addTree(); // *
			if (right != null) // *
				total += right.addTree(); // *
			return total; // *
		}
	}
}