Represents an edge in the control flow graph, pointing from Source to Target.
Ejemplo n.º 1
0
        public  ControlFlowGraph BuildGraph(IList<ILNode> nodes, ILLabel entryLabel)
        {

            int index = 0;
            List<ControlFlowNode> cfNodes = new List<ControlFlowNode>();
            ControlFlowNode entryPoint = new ControlFlowNode(index++, 0, ControlFlowNodeType.EntryPoint);
            cfNodes.Add(entryPoint);
            ControlFlowNode regularExit = new ControlFlowNode(index++, -1, ControlFlowNodeType.RegularExit);
            cfNodes.Add(regularExit);

            // Create graph nodes
            labelToCfNode = new Dictionary<ILLabel, ControlFlowNode>();
            Dictionary<ILNode, ControlFlowNode> astNodeToCfNode = new Dictionary<ILNode, ControlFlowNode>();
            foreach (ILBasicBlock node in nodes)
            {
                ControlFlowNode cfNode = new ControlFlowNode(index++, -1, ControlFlowNodeType.Normal);
                cfNodes.Add(cfNode);
                astNodeToCfNode[node] = cfNode;
                cfNode.UserData = node;

                // Find all contained labels
                foreach (ILLabel label in node.GetSelfAndChildrenRecursive<ILLabel>())
                {
                    labelToCfNode[label] = cfNode;
                }
            }

            // Entry endge
            ControlFlowNode entryNode = labelToCfNode[entryLabel];
            ControlFlowEdge entryEdge = new ControlFlowEdge(entryPoint, entryNode, JumpType.Normal);
            entryPoint.Outgoing.Add(entryEdge);
            entryNode.Incoming.Add(entryEdge);

            // Create edges
            foreach (ILBasicBlock node in nodes)
            {
                ControlFlowNode source = astNodeToCfNode[node];

                // Find all branches
                foreach (ILLabel target in node.GetSelfAndChildrenRecursive<ILExpression>(e => e.IsBranch()).SelectMany(e => e.GetBranchTargets()))
                {
                    ControlFlowNode destination;

                    // Labels which are out of out scope will not be in the collection
                    // Insert self edge only if we are sure we are a loop
                    if (labelToCfNode.TryGetValue(target, out destination) && (destination != source || target == node.Body.FirstOrDefault()))
                    {
                        ControlFlowEdge edge = new ControlFlowEdge(source, destination, JumpType.Normal);
                        source.Outgoing.Add(edge);
                        destination.Incoming.Add(edge);
                    }
                }
            }

            return new ControlFlowGraph(cfNodes.ToArray());
        }
Ejemplo n.º 2
0
 void CreateEdge(ControlFlowNode source, ControlFlowNode destination)
 {
     ControlFlowEdge edge = new ControlFlowEdge(source, destination, JumpType.Normal);
     source.Outgoing.Add(edge);
     destination.Incoming.Add(edge);
 }