asm.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 156 行

// $Id: ASM.java,v 1.4 1999/11/15 07:48:05 deberg Exp $

package java6035.tools.ASM;
import java.util.*;
import java6035.tools.IR.Walkable;

/**
 * ASM represents a list of assembly entries, such as instructions, labels,
 * comments, etc.
 */

public class ASM implements Walkable
{
    Vector asm;
  
    public ASM()
    {
	asm = new Vector();
    }

    /**
     * Returns an enumeration of ASM entries
     */
    public Enumeration nodes()
    {
	return asm.elements();
    }

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

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

    /**
     * Removes a node.
     */
    public void removeEntry(ASMEntry n)
    {
	asm.removeElement(n);
    }

    /**
     * Returns a node at index i. 
     */
    public ASMEntry getEntryAt(int i)
    {
	return (ASMEntry) asm.elementAt(i);
    }

    /**
     * Replace the node at index i with a new one. 
     */
    public void setEntryAt(ASMEntry a, int i)
    {
	if (a == null)
	    throw new ASMException("ASM: setEntryAt: node null");

	asm.setElementAt(a,i);
    }

    /**
     * Insert given node into this block at index i. 
     */
    public void insertEntryAt(ASMEntry a, int i)
    {
	if (a == null)
	    throw new ASMException("ASM: insertEntryAt: node null");

	asm.insertElementAt(a,i);
    }

    /**
     * Add given node to this block. 
     */
    public void appendEntry(ASMEntry a)
    {
	if (a == null)
	    throw new ASMException("ASM: appendEntry: node null");

	asm.addElement(a);
    }

    // add comment to last instruction
    public void commentLast(String s)
    {
        ASMEntry e = (ASMEntry)asm.elementAt(asm.size()-1);
        
        if (e instanceof SPARCInstruction) {
            ((SPARCInstruction)e).setComment(s);
        }
    }

    /**
     * Add the set of nodes in the given vector. 
     */
    public void appendEntries(Vector alist)
    {
	if (alist == null)
	    throw new ASMException("ASM: appendEntries: list null");

	for (int i=0; i<alist.size(); i++)
	{
	    Object o = alist.elementAt(i);
	    if (o != null && o instanceof ASMEntry)
		this.appendEntry((ASMEntry)o);
	    else
		throw new ASMException
		    ("ASM: appendEntries: node null or not a ASMEntry");
	}
    }

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

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

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

    public String PPrint(int indent, boolean recursive)
    {
        return "";
    }

}