Feat: Initial setup + PDG (Needs checking tho)

src/org/lsmr/cfg/Node.java

@@ -0,0 +1,171 @@
+package org.lsmr.cfg;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Represents nodes in a CFG. Each node is expected to have a non-null,
+ * non-empty label. A node is tightly connected to a specific graph, so the
+ * creation of nodes is permitted only via
+ * {@link ControlFlowGraph#buildNode(String)}.
+ */
+public class Node {
+	private ControlFlowGraph graph;
+	private Set<Edge> inEdges = new HashSet<>();
+	private Set<Edge> outEdges = new HashSet<>();
+	private String label;
+
+	Node(String label) {
+		if(label == null || label.length() < 1)
+			throw new IllegalArgumentException();
+
+		this.label = label;
+	}
+
+	/**
+	 * Accesses the label for this node.
+	 * 
+	 * @return The label for this node. Should not be null; should not be empty.
+	 */
+	public String label() {
+		return label;
+	}
+
+	/**
+	 * Accesses the parent graph for this node.
+	 * 
+	 * @return The parent graph for this node. Should not be null.
+	 */
+	public ControlFlowGraph graph() {
+		return graph;
+	}
+
+	/**
+	 * Accesses the out-edges of this node as an unmodifiable set.
+	 * 
+	 * @return An unmodifiable set of the out-edges of this node.
+	 */
+	public Set<Edge> outEdges() {
+		return Collections.unmodifiableSet(outEdges);
+	}
+
+	/**
+	 * Accesses the in-edges of this node as an unmodifiable set.
+	 * 
+	 * @return An unmodifiable set of the in-edges of this node.
+	 */
+	public Set<Edge> inEdges() {
+		return Collections.unmodifiableSet(inEdges);
+	}
+
+	/**
+	 * Adds the indicated edge to this node as an in-edge.
+	 * 
+	 * @param edge
+	 *            The edge to be added as an in-edge
+	 * @throws IllegalArgumentException
+	 *             If the edge is null.
+	 * @throws IllegalStateException
+	 *             If the target node of the edge is not identical to this node.
+	 */
+	public void addInEdge(Edge edge) {
+		if(edge == null)
+			throw new IllegalArgumentException();
+
+		if(edge.target() != this)
+			throw new IllegalStateException();
+
+		if(edge.source().graph() == null || edge.target().graph() == null)
+			throw new IllegalStateException();
+
+		inEdges.add(edge);
+	}
+
+	/**
+	 * Adds the indicated edge to this node as an out-edge.
+	 * 
+	 * @param edge
+	 *            The edge to be added as an out-edge
+	 * @throws IllegalArgumentException
+	 *             If the edge is null.
+	 * @throws IllegalStateException
+	 *             If the source node of the edge is not identical to this node.
+	 */
+	public void addOutEdge(Edge edge) {
+		if(edge == null)
+			throw new IllegalArgumentException();
+
+		if(edge.source() != this)
+			throw new IllegalStateException();
+
+		if(edge.source().graph() == null || (edge.target() != null && edge.target().graph() == null))
+			throw new IllegalStateException();
+
+		outEdges.add(edge);
+	}
+
+	void setGraph(ControlFlowGraph graph) {
+		if(this.graph != null) {
+			if(graph == null)
+				this.graph = null;
+		}
+		else if(graph == null)
+			throw new IllegalArgumentException();
+		else
+			this.graph = graph;
+	}
+
+	@Override
+	public int hashCode() {
+		return label.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if(obj instanceof Node) {
+			Node other = (Node)obj;
+
+			return label.equals(other.label);
+		}
+
+		return false;
+	}
+
+	@Override
+	public String toString() {
+		StringBuilder sb = new StringBuilder();
+
+		sb.append("node ");
+		sb.append(label);
+		sb.append(": in-edges [");
+
+		boolean start = true;
+
+		for(Edge edge : inEdges) {
+			if(start)
+				start = false;
+			else
+				sb.append(", ");
+
+			sb.append(edge.toString());
+		}
+
+		sb.append("]; out-edges [");
+
+		start = true;
+
+		for(Edge edge : outEdges) {
+			if(start)
+				start = false;
+			else
+				sb.append(", ");
+
+			sb.append(edge.toString());
+		}
+
+		sb.append("]");
+
+		return sb.toString();
+	}
+}