ControlFlowNode.java

   1 import com.sun.source.tree.Tree;
   2 import java.util.*;
   3
   4 /**
   5  * A single node in a control flow graph.
   6  * @author <a href="mailto:koenig@cs.washington.edu">David Matthew Jerry Koenig</a>
   7  */
   8 public class ControlFlowNode {
   9     private ControlFlowNode elseSuccessor;
  10     private Map<Throwable, ControlFlowNode> exceptionSuccessors;
  11     private List<ControlFlowNode> predecessors;
  12     private ControlFlowNode successor;
  13     private Tree tree;
  14
  15     /**
  16      * Sets up a control flow node with no predecessors or exception
  17      * successors.
  18      */
  19     public ControlFlowNode(Tree tree) {
  20         exceptionSuccessors = new HashMap<Throwable, ControlFlowNode>();
  21         predecessors = new ArrayList<ControlFlowNode>();
  22         this.tree = tree;
  23     }
  24
  25     /**
  26      * If the current node is a condition in a loop, if statement, or the
  27      * ternary operator, the path to take if the condition is false.
  28      */
  29     public ControlFlowNode getElseSuccessor() {
  30         return elseSuccessor;
  31     }
  32
  33     /**
  34      * A map from Throwables that may be thrown in the evaluation of this
  35      * node to the path that execution will take on the throwing of the
  36      * corresponding throwable.
  37      */
  38     public Map<Throwable, ControlFlowNode> getExceptionSuccessors() {
  39         return exceptionSuccessors;
  40     }
  41
  42     /**
  43      * All incoming paths to this node.
  44      */
  45     public List<ControlFlowNode> getPredecessors() {
  46         return predecessors;
  47     }
  48
  49     /**
  50      * The outgoing path of execution. If the current node is a condition in
  51      * a loop, if statement, or the ternary operator, the path to take if the
  52      * condition is true.
  53      */
  54     public ControlFlowNode getSuccessor() {
  55         return successor;
  56     }
  57
  58     /**
  59      * Returns the node in the abstract syntax tree that corresponds to this
  60      * node in the control flow graph.
  61      */
  62     public Tree getTree() {
  63         return tree;
  64     }
  65
  66     /**
  67      * Sets the following node for normal execution. If the current node is a
  68      * condition in a loop, if statement, or the ternary operator, the path to
  69      * take if the condition is true.
  70      */
  71     public void setSuccessor(ControlFlowNode successor) {
  72         this.successor = successor;
  73     }
  74
  75     /**
  76      * Sets the path to take if the current node is a condition in a loop, if
  77      * statement, or the ternary operator, and the condition is false.
  78      */
  79     public void setElseSuccessor(ControlFlowNode elseSuccessor) {
  80         this.elseSuccessor = elseSuccessor;
  81     }
  82
  83     /**
  84      * Sets the node in the abstract syntax tree that corresponds to this node
  85      * in the control flow graph.
  86      */
  87     public void setTree(Tree tree) {
  88         this.tree = tree;
  89     }
  90 }