modifiablebytecodevisitor.java

来自「纯java操作系统jnode,安装简单和操作简单的个人使用的Java操作系统」· Java 代码 · 共 80 行

/*
 * $Id: ModifiableBytecodeVisitor.java,v 1.1 2003/11/25 11:42:13 epr Exp $
 */
package org.jnode.vm.bytecode;

/**
 * Utility class used for bytecode visitors that modify the bytecode during
 * the visit.
 * 
 * @author Ewout Prangsma ([e-mail])
 */
public class ModifiableBytecodeVisitor extends BytecodeVisitorSupport {

	private final BytecodeModifier modifier;
	private int noLocals;
	private int maxStack;

	public ModifiableBytecodeVisitor(BytecodeModifier modifier, int noLocals, int maxStack) {
		this.modifier = modifier;
		this.noLocals = noLocals;
		this.maxStack = maxStack;
	}

	protected final void insert(int bcOfs, int skipLen, byte[] src) {
		modifier.insert(bcOfs, skipLen, src, 0, src.length, noLocals, maxStack);
		final byte[] code = modifier.getNewCode();
		final BytecodeParser parser = getParser();
		parser.setCode(code);
		parser.adjustEndPC(src.length - skipLen);
	}

	protected final void remove(int bcOfs, int len) {
		modifier.remove(bcOfs, len, noLocals, maxStack);
		final byte[] code = modifier.getNewCode();
		final BytecodeParser parser = getParser();
		parser.setCode(code);
		parser.adjustEndPC(-len);
	}

	protected byte[] getNewCode() {
		return modifier.getNewCode();
	}

	/**
	 * @return The bytecode modifier
	 */
	protected final BytecodeModifier getModifier() {
		return this.modifier;
	}

	/**
	 * @return The maximum stack size
	 */
	public int getMaxStack() {
		return this.maxStack;
	}

	/**
	 * @param maxStack
	 */
	public void setMaxStack(int maxStack) {
		this.maxStack = maxStack;
	}

	/**
	 * @return The number of locals
	 */
	public int getNoLocals() {
		return this.noLocals;
	}

	/**
	 * @param noLocals
	 */
	public void setNoLocals(int noLocals) {
		this.noLocals = noLocals;
	}

}