/*
* JBoss, Home of Professional Open Source.
*
* Copyright 2012 Red Hat, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
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));
}
}
}
public LocalVariableState(final ConstPool pool, final String ... entries) {
this.constPool = pool;
contents = new ArrayList<StackEntry>();
for(String c : entries) {
final StackEntry entry = StackEntry.of(c, constPool);
contents.add(entry);
}
}
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());
}
}
}