allocexpr.java

用Java实现的编译器。把源代码编译成SPARC汇编程序

// $Id: AllocExpr.java,v 1.6 2000/10/10 15:47:49 mdeeds Exp $

package java6035.tools.IR;

/**
 * AllocExpr represents an allocation expression.
 */

public class AllocExpr extends Expression
{
    protected IRType type;
    protected Rhs number;

    /**
     * Constructs an AllocExpr indicating the allocation of the
     * specified Rhs (number).  This will typically be an array or
     * class.
     *
     * Requires: type, number are not Null.
     **/
    public AllocExpr(IRType type, Rhs number)
    {
	this.type = type;
	this.number = number;

	if (this.type == null)
	    throw new IRException("AllocExpr: constructor: type null");

	if (this.number == null)
	    throw new IRException("AllocExpr: constructor: number null");
    }

    /**
     * Returns the globally specified ID for this type of Expression.
     * (i.e. ALLOC_EXPR)
     **/
    protected int expkind()
    {
	return ALLOC_EXPR;
    }

    /**
     * Returns the type of this allocation.
     */
    public IRType getAllocType()
    {
	return type;
    }

    /**
     * Sets the type of this allocation.
     *
     * Requires: type is not null
     **/
    public void setAllocType(IRType type)
    {
	this.type = type;
	
	if (this.type == null)
	    throw new IRException("AllocExpr: setAllocType: type null");
    }

    /**
     * Returns the number of allocations.
     */
    public Rhs getNumber()
    {
	return number;
    }

    /**
     * Sets the number of allocation.
     */
    public void setNumber(Rhs number)
    {
	this.number = number;

	if (this.number == null)
	    throw new IRException("AllocExpr: setNumber: number null");
    }

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

    /**
     * Walkable interface: returns the number of neighbors.
     */
    public int getNeighborCount()
    {
	return 2;
    }

    /**
     * Walkable interface: returns the specified neighbor: 0, type; 
     * 1, number.
     */
    public Object getNeighbor(int index)
    {
	if (index == 0)
	    return type;
	else if (index == 1)
	    return number;
	return null;
    }

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

        if (recursive) output += number.PPrint(indent+2, true);

        for(int i=0;i<indent;i++) output += " ";
        output += ") /* alloc_expr */\n";

        return output;
    }
}