/*******************************************************************************
* Copyright (c) 2007 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package com.ibm.wala.classLoader;
import java.io.Reader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import com.ibm.wala.ipa.cha.ClassHierarchyWarning;
import com.ibm.wala.ipa.cha.IClassHierarchy;
import com.ibm.wala.shrikeCT.InvalidClassFileException;
import com.ibm.wala.types.FieldReference;
import com.ibm.wala.types.MethodReference;
import com.ibm.wala.types.Selector;
import com.ibm.wala.types.TypeName;
import com.ibm.wala.types.TypeReference;
import com.ibm.wala.types.annotations.Annotation;
import com.ibm.wala.util.collections.BimodalMap;
import com.ibm.wala.util.collections.HashMapFactory;
import com.ibm.wala.util.collections.HashSetFactory;
import com.ibm.wala.util.collections.SmallMap;
import com.ibm.wala.util.debug.Assertions;
import com.ibm.wala.util.strings.Atom;
import com.ibm.wala.util.strings.ImmutableByteArray;
import com.ibm.wala.util.warnings.Warning;
import com.ibm.wala.util.warnings.Warnings;
/**
* A class representing which originates in some form of bytecode.
*
* @param <T> type of classloader which loads this format of class.
*/
public abstract class BytecodeClass<T extends IClassLoader> implements IClass {
protected BytecodeClass(T loader, IClassHierarchy cha) {
this.loader = loader;
this.cha = cha;
}
/**
* An Atom which holds the name of the super class. We cache this for efficiency reasons.
*/
protected ImmutableByteArray superName;
/**
* The names of interfaces for this class. We cache this for efficiency reasons.
*/
protected ImmutableByteArray[] interfaceNames;
/**
* The object that loaded this class.
*/
protected final T loader;
/**
* Governing class hierarchy for this class
*/
protected final IClassHierarchy cha;
/**
* A mapping from Selector to IMethod
*
* TODO: get rid of this for classes (though keep it for interfaces) instead ... use a VMT.
*/
protected volatile Map<Selector, IMethod> methodMap;
/**
* A mapping from Selector to IMethod used to cache method lookups from superclasses
*/
protected Map<Selector, IMethod> inheritCache;
/**
* Canonical type representation
*/
protected TypeReference typeReference;
/**
* superclass
*/
protected IClass superClass;
/**
* Compute the superclass lazily.
*/
protected boolean superclassComputed = false;
/**
* The IClasses that represent all interfaces this class implements (if it's a class) or extends (it it's an interface)
*/
protected Collection<IClass> allInterfaces = null;
/**
* The instance fields declared in this class.
*/
protected IField[] instanceFields;
/**
* The static fields declared in this class.
*/
protected IField[] staticFields;
/**
* hash code; cached here for efficiency
*/
protected int hashCode;
private final HashMap<Atom, IField> fieldMap = HashMapFactory.make(5);
/**
* A warning for when we get a class not found exception
*/
private static class ClassNotFoundWarning extends Warning {
final ImmutableByteArray className;
ClassNotFoundWarning(ImmutableByteArray className) {
super(Warning.SEVERE);
this.className = className;
}
@Override
public String getMsg() {
return getClass().toString() + " : " + className;
}
public static ClassNotFoundWarning create(ImmutableByteArray className) {
return new ClassNotFoundWarning(className);
}
}
public abstract Module getContainer();
@Override
public IClassLoader getClassLoader() {
return loader;
}
protected abstract IMethod[] computeDeclaredMethods() throws InvalidClassFileException;
@Override
public TypeReference getReference() {
return typeReference;
}
@Override
public String getSourceFileName() {
return loader.getSourceFileName(this);
}
@Override
public Reader getSource() {
return loader.getSource(this);
}
@Override
public int hashCode() {
return hashCode;
}
@Override
public String toString() {
return getReference().toString();
}
@Override
public boolean isArrayClass() {
return false;
}
@Override
public IClassHierarchy getClassHierarchy() {
return cha;
}
@Override
public TypeName getName() {
return getReference().getName();
}
@Override
public boolean isReferenceType() {
return getReference().isReferenceType();
}
@Override
public IField getField(Atom name) {
if (fieldMap.containsKey(name)) {
return fieldMap.get(name);
} else {
List<IField> fields = findDeclaredField(name);
if (!fields.isEmpty()) {
if (fields.size() == 1) {
IField f = fields.iterator().next();
fieldMap.put(name, f);
return f;
} else {
throw new IllegalStateException("multiple fields with name " + name);
}
} else if ((superClass = getSuperclass()) != null) {
IField f = superClass.getField(name);
if (f != null) {
fieldMap.put(name, f);
return f;
}
}
// try superinterfaces
for (IClass i : getAllImplementedInterfaces()) {
IField f = i.getField(name);
if (f != null) {
fieldMap.put(name, f);
return f;
}
}
}
return null;
}
@Override
public IField getField(Atom name, TypeName type) {
boolean unresolved = false;
try {
// typically, there will be at most one field with the name
IField field = getField(name);
if (field != null && field.getFieldTypeReference().getName().equals(type)) {
return field;
} else {
unresolved = true;
}
} catch (IllegalStateException e) {
assert e.getMessage().startsWith("multiple fields with");
unresolved = true;
}
if(unresolved){
// multiple fields. look through all of them and see if any have the appropriate type
List<IField> fields = findDeclaredField(name);
for (IField f : fields) {
if (f.getFieldTypeReference().getName().equals(type)) {
return f;
}
}
// check superclass
if (getSuperclass() != null) {
IField f = superClass.getField(name, type);
if (f != null) {
return f;
}
}
// try superinterfaces
for (IClass i : getAllImplementedInterfaces()) {
IField f = i.getField(name, type);
if (f != null) {
return f;
}
}
}
return null;
}
private void computeSuperclass() {
superclassComputed = true;
if (superName == null) {
if (!getReference().equals(loader.getLanguage().getRootType())) {
superClass = loader.lookupClass(loader.getLanguage().getRootType().getName());
}
return;
}
superClass = loader.lookupClass(TypeName.findOrCreate(superName));
}
@Override
public IClass getSuperclass() {
if (!superclassComputed) {
computeSuperclass();
}
if (superClass == null && !getReference().equals(TypeReference.JavaLangObject)) {
throw new IllegalStateException("No superclass found for " + this + " Superclass name " + superName);
}
return superClass;
}
/*
* @see com.ibm.wala.classLoader.IClass#getAllFields()
*/
@Override
public Collection<IField> getAllFields() {
Collection<IField> result = new LinkedList<IField>();
result.addAll(getAllInstanceFields());
result.addAll(getAllStaticFields());
return result;
}
/*
* @see com.ibm.wala.classLoader.IClass#getAllImplementedInterfaces()
*/
@Override
public Collection<IClass> getAllImplementedInterfaces() {
if (allInterfaces != null) {
return allInterfaces;
} else {
Collection<IClass> C = computeAllInterfacesAsCollection();
allInterfaces = Collections.unmodifiableCollection(C);
return allInterfaces;
}
}
/*
* @see com.ibm.wala.classLoader.IClass#getDeclaredFields()
*/
@Override
public Collection<IField> getDeclaredInstanceFields() {
if (instanceFields == null) {
return Collections.emptySet();
} else {
return Collections.unmodifiableList(Arrays.asList(instanceFields));
}
}
/*
* @see com.ibm.wala.classLoader.IClass#getDeclaredFields()
*/
@Override
public Collection<IField> getDeclaredStaticFields() {
return Collections.unmodifiableList(Arrays.asList(staticFields));
}
/*
* @see com.ibm.wala.classLoader.IClass#getDirectInterfaces()
*/
@Override
public Collection<? extends IClass> getDirectInterfaces() {
return array2IClassSet(interfaceNames);
}
/*
* @see com.ibm.wala.classLoader.IClass#getAllInstanceFields()
*/
@Override
public Collection<IField> getAllInstanceFields() {
Collection<IField> result = new LinkedList<IField>(getDeclaredInstanceFields());
IClass s = getSuperclass();
while (s != null) {
result.addAll(s.getDeclaredInstanceFields());
s = s.getSuperclass();
}
return result;
}
/*
* @see com.ibm.wala.classLoader.IClass#getAllStaticFields()
*/
@Override
public Collection<IField> getAllStaticFields() {
Collection<IField> result = new LinkedList<IField>(getDeclaredStaticFields());
IClass s = getSuperclass();
while (s != null) {
result.addAll(s.getDeclaredStaticFields());
s = s.getSuperclass();
}
return result;
}
/*
* @see com.ibm.wala.classLoader.IClass#getAllMethods()
*/
@Override
public Collection<IMethod> getAllMethods() {
Collection<IMethod> result = new LinkedList<IMethod>();
Iterator<IMethod> declaredMethods = getDeclaredMethods().iterator();
while (declaredMethods.hasNext()) {
result.add(declaredMethods.next());
}
if (isInterface()) {
for (IClass i : getDirectInterfaces()) {
result.addAll(i.getAllMethods());
}
}
IClass s = getSuperclass();
while (s != null) {
Iterator<IMethod> superDeclaredMethods = s.getDeclaredMethods().iterator();
while (superDeclaredMethods.hasNext()) {
result.add(superDeclaredMethods.next());
}
s = s.getSuperclass();
}
return result;
}
/*
* @see com.ibm.wala.classLoader.IClass#getDeclaredMethods()
*/
@Override
public Collection<IMethod> getDeclaredMethods() {
try {
computeMethodMapIfNeeded();
} catch (InvalidClassFileException e) {
e.printStackTrace();
Assertions.UNREACHABLE();
}
return Collections.unmodifiableCollection(methodMap.values());
}
/*
* @see com.ibm.wala.classLoader.IClass#getMethod(com.ibm.wala.types.Selector)
*/
@Override
public IMethod getMethod(Selector selector) {
try {
computeMethodMapIfNeeded();
} catch (InvalidClassFileException e1) {
e1.printStackTrace();
Assertions.UNREACHABLE();
}
// my methods + cached parent stuff
IMethod result = methodMap.get(selector);
if (result != null) {
return result;
}
if (inheritCache != null) {
result = inheritCache.get(selector);
if (result != null) {
return result;
}
}
// check parent, caching if found
if (!selector.equals(MethodReference.clinitSelector) && !selector.equals(MethodReference.initSelector)) {
IClass superclass = getSuperclass();
if (superclass != null) {
IMethod inherit = superclass.getMethod(selector);
if (inherit != null) {
if (inheritCache == null) {
inheritCache = new BimodalMap<Selector, IMethod>(5);
}
inheritCache.put(selector, inherit);
return inherit;
}
}
}
// no method found
if (inheritCache == null) {
inheritCache = new BimodalMap<Selector, IMethod>(5);
}
inheritCache.put(selector, null);
return null;
}
protected void populateFieldArrayFromList(List<FieldImpl> L, IField[] A) {
Iterator<FieldImpl> it = L.iterator();
for (int i = 0; i < A.length; i++) {
A[i] = it.next();
}
}
/**
* @return Collection of IClasses, representing the interfaces this class implements.
*/
protected Collection<IClass> computeAllInterfacesAsCollection() {
Collection<? extends IClass> c = getDirectInterfaces();
Set<IClass> result = HashSetFactory.make();
for (Iterator<? extends IClass> it = c.iterator(); it.hasNext();) {
IClass klass = it.next();
if (klass.isInterface()) {
result.add(klass);
} else {
Warnings.add(ClassHierarchyWarning.create("expected an interface " + klass));
}
}
// at this point result holds all interfaces the class directly extends.
// now expand to a fixed point.
Set<IClass> last = null;
do {
last = HashSetFactory.make(result);
for (IClass i : last) {
result.addAll(i.getDirectInterfaces());
}
} while (last.size() < result.size());
// now add any interfaces implemented by the super class
IClass sup = null;
sup = getSuperclass();
if (sup != null) {
result.addAll(sup.getAllImplementedInterfaces());
}
return result;
}
/**
* @param interfaces a set of class names
* @return Set of all IClasses that can be loaded corresponding to the class names in the interfaces array; raise warnings if
* classes can not be loaded
*/
private Collection<IClass> array2IClassSet(ImmutableByteArray[] interfaces) {
ArrayList<IClass> result = new ArrayList<IClass>(interfaces.length);
for (int i = 0; i < interfaces.length; i++) {
ImmutableByteArray name = interfaces[i];
IClass klass = null;
klass = loader.lookupClass(TypeName.findOrCreate(name));
if (klass == null) {
Warnings.add(ClassNotFoundWarning.create(name));
} else {
result.add(klass);
}
}
return result;
}
protected List<IField> findDeclaredField(Atom name) {
List<IField> result = new ArrayList<IField>(1);
if (instanceFields != null) {
for (int i = 0; i < instanceFields.length; i++) {
if (instanceFields[i].getName() == name) {
result.add(instanceFields[i]);
}
}
}
if (staticFields != null) {
for (int i = 0; i < staticFields.length; i++) {
if (staticFields[i].getName() == name) {
result.add(staticFields[i]);
}
}
}
return result;
}
protected void addFieldToList(List<FieldImpl> L, Atom name, ImmutableByteArray fieldType, int accessFlags,
Collection<Annotation> annotations) {
TypeName T = null;
if (fieldType.get(fieldType.length() - 1) == ';') {
T = TypeName.findOrCreate(fieldType, 0, fieldType.length() - 1);
} else {
T = TypeName.findOrCreate(fieldType);
}
TypeReference type = TypeReference.findOrCreate(getClassLoader().getReference(), T);
FieldReference fr = FieldReference.findOrCreate(getReference(), name, type);
FieldImpl f = new FieldImpl(this, fr, accessFlags, annotations);
L.add(f);
}
/**
* set up the methodMap mapping
*/
protected void computeMethodMapIfNeeded() throws InvalidClassFileException {
if (methodMap == null) {
synchronized (this) {
if (methodMap == null) {
IMethod[] methods = computeDeclaredMethods();
final Map<Selector, IMethod> tmpMethodMap;
if (methods.length > 5) {
tmpMethodMap = HashMapFactory.make(methods.length);
} else {
tmpMethodMap= new SmallMap<Selector, IMethod>();
}
for (int i = 0; i < methods.length; i++) {
IMethod m = methods[i];
tmpMethodMap.put(m.getReference().getSelector(), m);
}
methodMap = tmpMethodMap;
}
}
}
}
public abstract Collection<Annotation> getAnnotations(boolean runtimeVisible) throws InvalidClassFileException;
}