/*
* JBoss, Home of Professional Open Source
* Copyright 2008-10 Red Hat and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*
* @authors Andrew Dinn
*/
package org.jboss.byteman.agent.adapter;
import org.jboss.byteman.agent.TransformContext;
import org.objectweb.asm.*;
/**
* asm Adapter class used to add a rule event trigger call to a method of som egiven class
*/
public class EntryTriggerAdapter extends RuleTriggerAdapter
{
public EntryTriggerAdapter(ClassVisitor cv, TransformContext transformContext)
{
super(cv, transformContext);
}
public MethodVisitor visitMethod(
final int access,
final String name,
final String desc,
final String signature,
final String[] exceptions)
{
MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
if (injectIntoMethod(name, desc)) {
if (name.equals("<init>")) {
return new EntryTriggerConstructorAdapter(mv, getTransformContext(), access, name, desc, signature, exceptions);
} else {
return new EntryTriggerMethodAdapter(mv, getTransformContext(), access, name, desc, signature, exceptions);
}
}
return mv;
}
/**
* a method visitor used to add a rule event trigger call to a method
*/
private class EntryTriggerMethodAdapter extends RuleTriggerMethodAdapter
{
protected boolean unlatched;
/**
* flag which says whether a trigger has been injected into this method
*/
private boolean visited;
/**
* label generated before in
*/
private Label startMarker;
private Label offsetMarker;
EntryTriggerMethodAdapter(MethodVisitor mv, TransformContext transformContext, int access, String name, String descriptor, String signature, String[] exceptions)
{
super(mv, transformContext, access, name, descriptor, signature, exceptions);
this.unlatched = true; // subclass can manipulate this to postponne visit
visited = false;
startMarker = null;
offsetMarker = null;
}
// if possible inject a trigger as soon as we visit the code. This will precede any visit to labels defined
// by the original program -- in particular the loop label for a while loop occuring at the start of the
// method body. if we don't do this then we can end up injecting the trigger into the body of the while
// loop
@Override
public void visitCode()
{
// call the super method first so we have a valid CFG and start label
super.visitCode();
if (unlatched && !visited) {
// if we inject here we keep markers for the original
// and offset start of real code. that allows us to identify
// parameters whose start pos has been pushed forward to the
// end marker and reset it to the start marker
startMarker = new Label();
visitLabel(startMarker);
visited = true;
injectTriggerPoint();
offsetMarker = new Label();
visitLabel(offsetMarker);
}
}
@Override
public void visitLocalVariable(String name, String desc, String signature, Label start, Label end, int index)
{
if (offsetMarker != null && (offsetMarker.getOffset() == start.getOffset())) {
// this local wil be a parameter whose start
// offset was originally 0 and now has been
// offset by the inejcted AT ENTRY code
// passing startMarker will reset it's start to 0
start = startMarker;
}
super.visitLocalVariable(name, desc, signature, start, end, index);
}
// we will not be able to inject into a constructor at visitCode because we need to delay until
// we have run the super constructor. so we also need to override each visitXXXINsn operation
// and inject a trigger point as soon as possible after the constructor unlatches the adapter.
@Override
public void visitInsn(int opcode) {
if (unlatched && !visited) {
visited = true;
injectTriggerPoint();
}
super.visitInsn(opcode);
}
@Override
public void visitIincInsn(int var, int increment) {
if (unlatched && !visited) {
visited = true;
injectTriggerPoint();
}
super.visitIincInsn(var, increment);
}
@Override
public void visitIntInsn(int opcode, int operand) {
if (unlatched && !visited) {
visited = true;
injectTriggerPoint();
}
super.visitIntInsn(opcode, operand);
}
@Override
public void visitLdcInsn(Object cst) {
if (unlatched && !visited) {
visited = true;
injectTriggerPoint();
}
super.visitLdcInsn(cst);
}
@Override
public void visitVarInsn(int opcode, int var) {
if (unlatched && !visited) {
visited = true;
injectTriggerPoint();
}
super.visitVarInsn(opcode, var);
}
@Override
public void visitTypeInsn(int opcode, String desc) {
if (unlatched && !visited) {
visited = true;
injectTriggerPoint();
}
super.visitTypeInsn(opcode, desc);
}
@Override
public void visitFieldInsn(int opcode, String owner, String name, String desc) {
if (unlatched && !visited) {
visited = true;
injectTriggerPoint();
}
super.visitFieldInsn(opcode, owner, name, desc);
}
@Override
public void visitMethodInsn(int opcode, String owner, String name, String desc, boolean itf) {
if (unlatched && !visited) {
visited = true;
injectTriggerPoint();
}
super.visitMethodInsn(opcode, owner, name, desc, itf);
}
@Override
public void visitJumpInsn(int opcode, Label label) {
if (unlatched && !visited) {
visited = true;
injectTriggerPoint();
}
super.visitJumpInsn(opcode, label);
}
@Override
public void visitTableSwitchInsn(int min, int max, Label dflt, Label[] labels) {
if (unlatched && !visited) {
visited = true;
injectTriggerPoint();
}
super.visitTableSwitchInsn(min, max, dflt, labels);
}
@Override
public void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels) {
if (unlatched && !visited) {
visited = true;
injectTriggerPoint();
}
super.visitLookupSwitchInsn(dflt, keys, labels);
}
@Override
public void visitMultiANewArrayInsn(String desc, int dims) {
if (unlatched && !visited) {
visited = true;
injectTriggerPoint();
}
super.visitMultiANewArrayInsn(desc, dims);
}
}
/**
* a method visitor used to add a rule event trigger call to a constructor -- this has to make sure
* the super constructor has been called before allowing a trigger call to be compiled
*/
private class EntryTriggerConstructorAdapter extends EntryTriggerMethodAdapter
{
EntryTriggerConstructorAdapter(MethodVisitor mv, TransformContext transformContext, int access, String name, String descriptor, String signature, String[] exceptions)
{
super(mv, getTransformContext(), access, name, descriptor, signature, exceptions);
this.unlatched = false;
}
public void visitMethodInsn(
final int opcode,
final String owner,
final String name,
final String desc,
final boolean itf)
{
super.visitMethodInsn(opcode, owner, name, desc, itf);
unlatched |= isSuperOrSiblingConstructorCall(opcode, owner, name);
}
}
}