returninstr.java

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// $Id: ReturnInstr.java,v 1.4 1999/09/30 01:48:34 deberg Exp $

package java6035.tools.IR;

/**
 * The ReturnInstr class captures a return statement. This class optionally
 * takes a Rhs value as the possible return value.
 */

public class ReturnInstr extends Instruction
{
    protected Rhs rhs;

    /**
     * Creates a return instruction with no return value.
     */
    public ReturnInstr()
    {
	rhs = null;
    }

    /**
     * Creates a return instruction with a return value in r.
     */
    public ReturnInstr(Rhs r)
    {
	this.rhs = r;
    }

    /**
     * Returns the type of the instruction.
     */
    protected int tnkind()
    {
	return RETURN_INSTR;
    }

    /**
     * Replaces the return value.
     */
    public void setReturnValue(Rhs v)
    {
	this.rhs = v;
    }

    /**
     * Returns the return value.
     */
    public Rhs getReturnValue()
    {
	return rhs;
    }

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

    /**
     * Walkable: returns the number of neighbors from this node.
     */
    public int getNeighborCount()
    {
	if (rhs != null) 
	    return 1;
	return 0;
    }

    /**
     * Walkable: returns a specific neighbor: 0, return value if there is one.
     */
    public Object getNeighbor(int index)
    {
	if (rhs != null)
	{
	    if (index == 0)
		return rhs;
	}
	return null;
    }

    public String PPrint(int indent, boolean recursive)
    {
        String output = new String();
        for(int i=0;i<indent;i++) output += " ";

        output += "(return_instruction\n";

        if (recursive)
            if (rhs != null) output += this.rhs.PPrint(indent+2, true);
        
        for(int i=0;i<indent;i++) output += " ";
        output += ") /* return_instruction */\n";

        return output;
    }

}