treeblock.java

用Java实现的编译器。把源代码编译成SPARC汇编程序

// $Id: TreeBlock.java,v 1.6 1999/10/06 03:40:32 deberg Exp $

package java6035.tools.IR;

import java.util.*;


/**
 * TreeBlock represents an ordered list of TreeNode objects forming a scope.
 */

public class TreeBlock extends TreeNode
{
    protected Vector body;
    protected LabelInstr label;

    /**
     * Constructs a TreeBlock object, given suffix of the label for the block.
     */
    public TreeBlock(String suffix)
    {
	body = new Vector();
	this.label = new LabelInstr(suffix);
    }

    /**
     * Constructs an empty TreeBlock object. 
     */
    public TreeBlock()
    {
        this("block");
    }

    protected int tnkind()
    {
	return TREE_BLOCK;
    }

    /**
     * Return the label instruction for this block.
     */
    public LabelInstr getLabelInstr()
    {
	return label;
    }

    /**
     * Returns an enumeration of tree nodes.
     */
    public Enumeration nodes()
    {
	return body.elements();
    }

    /**
     * Returns the size of the body.
     */
    public int size()
    {
	return body.size();
    }

    /**
     * Removes a node at index i. 
     */
    public void removeNodeAt(int i)
    {
	body.removeElementAt(i);
    }

    /**
     * Removes a node.
     */
    public void removeNode(TreeNode n)
    {
	body.removeElement(n);
    }

    /**
     * Returns a node at index i. 
     */
    public TreeNode getNodeAt(int i)
    {
	return (TreeNode) body.elementAt(i);
    }

    /**
     * Replace the node at index i with a new one. 
     */
    public void setNodeAt(TreeNode tn, int i)
    {
	if (tn == null)
	    throw new IRException("TreeBlock: setNodeAt: node null");

	body.setElementAt(tn,i);
        tn.setParent(this);
    }

    /**
     * Insert given node into this block at index i. 
     */
    public void insertNodeAt(TreeNode tn, int i)
    {
	if (tn == null)
	    throw new IRException("TreeBlock: insertNodeAt: node null");

	body.insertElementAt(tn,i);
        tn.setParent(this);
    }

    /**
     * Add given node to this block. 
     */
    public void appendNode(TreeNode tn)
    {
	if (tn == null)
	    throw new IRException("TreeBlock: appendNode: node null");

	body.addElement(tn);
        tn.setParent(this);
    }

    /**
     * Add the set of nodes in the given vector. 
     */
    public void appendNodes(Vector tnlist)
    {
	if (tnlist == null)
	    throw new IRException("TreeBlock: appendNodes: list null");

	for (int i=0; i<tnlist.size(); i++)
	{
	    Object o = tnlist.elementAt(i);
	    if (o != null && o instanceof TreeNode) {
		this.appendNode((TreeNode)o);
                ((TreeNode)o).setParent(this);
            }
            else
		throw new IRException
		    ("TreeBlock: appendNodes: node null or not a TreeNode");
	}
    }

    /**
     * Add the set of nodes in the given vector. 
     */
    public void appendNodes(TreeBlock tb)
    {
	if (tb == null)
	    throw new IRException("TreeBlock: appendNodes: list null");

	for (int i=0; i<tb.size(); i++)
	{
	    Object o = tb.getNodeAt(i);
	    if (o != null && o instanceof TreeNode) {
		this.appendNode((TreeNode)o);
                ((TreeNode)o).setParent(this);
            }
            else
		throw new IRException
		    ("TreeBlock: appendNodes: node null or not a TreeNode");
	}
    }

    /**
     * Walkable interface: get name of the node.
     */
    public String getNodeName()
    {
        return "block";
    }

    /**
     * Walkable interface: return number of neighbors.
     */
    public int getNeighborCount()
    {
	return 1+size();
    }

    /**
     * Walkable interface: return the requested neighbor: 0, label; 1 - n,
     * elements of the body (index 0 - n-1).
     */
    public Object getNeighbor(int index)
    {
	if (index == 0)
	    return this.label;
	else
	    return getNodeAt(index-1);
    }

    public String PPrint(int indent, boolean recursive)
    {
        String output = new String();
        for(int i=0;i<indent;i++) output += " ";
        output += "(tree_block "+label.getLabel().toString()+"\n";
        indent += 2;
        if (recursive) {
            for(int i=0;i<getNeighborCount();i++) {
                Object o = getNeighbor(i);
                if (o instanceof Walkable) {
                    output += 
                    ((Walkable)o).PPrint(indent, recursive);
                } else {
                    for(int j=0;j<indent;j++) output+=" ";
                    output += o.toString() + "\n";
                }
            }
        } else {
            for(int i=0;i<indent;i++) output += " ";
            output += getNeighborCount();
            output += " elements)\n";
        }

        indent -= 2;
        for(int i=0;i<indent;i++) output += " ";
        output += ") /* tree_block "+label.getLabel().toString()+" */\n";
        return output;
    }
}