/*
* JBoss, Home of Professional Open Source
* Copyright 2010, Red Hat Inc., and individual contributors as indicated
* 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.
*/
package org.jboss.classfilewriter.code;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.jboss.classfilewriter.ClassMethod;
import org.jboss.classfilewriter.InvalidBytecodeException;
import org.jboss.classfilewriter.constpool.ConstPool;
/**
* In immutable local variable state
*
* @author Stuart Douglas
*
*/
public class LocalVariableState {
/**
* The contents, null is used to represent the additional spot taken up by a wide variable.
* <p>
* This list may be shared between frames, so it must never be modified
* <p>
* The very first element represents the first local variable (this for non static methods)
*/
private final List<StackEntry> contents;
private final ConstPool constPool;
/**
* construct the initial local variable state for a method
*/
public LocalVariableState(ClassMethod method) {
this.constPool = method.getClassFile().getConstPool();
contents = new ArrayList<StackEntry>();
if (!method.isStatic()) {
if (method.isConstructor()) {
contents.add(new StackEntry(StackEntryType.UNINITIALIZED_THIS, method.getClassFile().getDescriptor()));
} else {
contents.add(StackEntry.of(method.getClassFile().getDescriptor(), method.getClassFile().getConstPool()));
}
}
for (String param : method.getParameters()) {
StackEntry entry = StackEntry.of(param, method.getClassFile().getConstPool());
contents.add(entry);
if (entry.isWide()) {
contents.add(new StackEntry(StackEntryType.TOP, param));
}
}
}
private LocalVariableState(final List<StackEntry> contents, ConstPool constPool) {
this.contents = contents;
this.constPool = constPool;
}
public List<StackEntry> getContents() {
return Collections.unmodifiableList(contents);
}
public StackEntry get(int index) {
return contents.get(index);
}
public LocalVariableState storeWide(int index, StackEntry entry) {
ArrayList<StackEntry> newContents = new ArrayList<StackEntry>(contents.size());
for (int i = 0; i <= index || i < contents.size(); ++i) {
if (index == i) {
newContents.add(entry);
newContents.add(new StackEntry(StackEntryType.TOP, entry.getDescriptor()));
++i;
} else if (i >= contents.size()) {
// write a null in unitialised slots
// not sure if this is correct
newContents.add(new StackEntry(StackEntryType.NULL, null));
} else {
newContents.add(contents.get(i));
}
}
return new LocalVariableState(newContents, constPool);
}
public LocalVariableState store(int index, StackEntry entry) {
ArrayList<StackEntry> newContents = new ArrayList<StackEntry>(contents.size());
for (int i = 0; i <= index || i < contents.size(); ++i) {
if (index == i) {
newContents.add(entry);
} else if (i >= contents.size()) {
// write a null in unitialised slots
// not sure if this is correct
newContents.add(new StackEntry(StackEntryType.NULL, null));
} else {
newContents.add(contents.get(i));
}
}
return new LocalVariableState(newContents, constPool);
}
public int size() {
return contents.size();
}
@Override
public String toString() {
return "Local Variables: " + contents.toString();
}
public LocalVariableState constructorCall(StackEntry entry) {
List<StackEntry> newContents = new ArrayList<StackEntry>(contents.size());
if (entry.getType() == StackEntryType.UNINITIALIZED_THIS) {
for (int i = 0; i < contents.size(); ++i) {
StackEntry stackEntry = contents.get(i);
if (stackEntry.getType() == StackEntryType.UNINITIALIZED_THIS) {
newContents.add(StackEntry.of(stackEntry.getDescriptor(), constPool));
} else {
newContents.add(stackEntry);
}
}
return new LocalVariableState(newContents, constPool);
} else if (entry.getType() == StackEntryType.UNITITIALIZED_OBJECT) {
for (int i = 0; i < contents.size(); ++i) {
StackEntry stackEntry = contents.get(i);
if (stackEntry.getType() == StackEntryType.UNITITIALIZED_OBJECT
&& stackEntry.getNewInstructionLocation() == entry.getNewInstructionLocation()) {
newContents.add(StackEntry.of(stackEntry.getDescriptor(), constPool));
} else {
newContents.add(stackEntry);
}
}
return new LocalVariableState(newContents, constPool);
} else {
throw new InvalidBytecodeException("entry is not an unitialized object. " + toString());
}
}
}