irobject.java

来自「用Java实现的编译器。把源代码编译成SPARC汇编程序」· Java 代码 · 共 65 行

// $Id: IRObject.java,v 1.6 1999/09/27 20:01:28 deberg Exp $

package java6035.tools.IR;

import java.util.*;

/**
 * IRObject represents an object in the IR.  
 * 
 * All IRObject instances are annotatable. An annotation is an <int,Object>
 * tuple, and can be placed on an IRObject using the annotate method.
 */

public abstract class IRObject implements Annotatable
{
    protected Hashtable annotations;

 
    public IRObject()
    {
        annotations = new Hashtable();
    }

    
    /**
     * Attach an annotation specified by the tag to the object. Remove
     * existing annotation with the same tag first. 
     */
    public void annotate(int tag, Object data)
    {
        annotations.remove(new Integer(tag));
	annotations.put(new Integer(tag), data);
    }


    /**
     * Searches for a particular annotation, given an annotation tag. Returns
     * the object if found, null otherwise.
     */
    public Object getAnnotation(int tag)
    {
	return annotations.get(new Integer(tag));
    }


    /**
     * Removes an annotation. Returns the object if annotation is found, null
     * otherwise.
     */
    public Object removeAnnotation(int tag)
    {
	return annotations.remove(new Integer(tag));
    }

    public Enumeration listTags()
    {
        return annotations.keys();
    }

    public Enumeration listAnnotations()
    {
        return annotations.elements();
    }
}