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/*
* Copyright (C) 2011 The Android Open Source Project
*
* 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 com.android.dex;
import com.android.dex.Code.CatchHandler;
import com.android.dex.Code.Try;
import com.android.dex.MethodHandle.MethodHandleType;
import com.android.dex.util.ByteInput;
import com.android.dex.util.ByteOutput;
import com.android.dex.util.FileUtils;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UTFDataFormatException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.AbstractList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.RandomAccess;
import java.util.zip.Adler32;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
/**
* The bytes of a dex file in memory for reading and writing. All int offsets
* are unsigned.
*/
public final class Dex {
private static final int CHECKSUM_OFFSET = 8;
private static final int CHECKSUM_SIZE = 4;
private static final int SIGNATURE_OFFSET = CHECKSUM_OFFSET + CHECKSUM_SIZE;
private static final int SIGNATURE_SIZE = 20;
// Provided as a convenience to avoid a memory allocation to benefit Dalvik.
// Note: libcore.util.EmptyArray cannot be accessed when this code isn't run on Dalvik.
static final short[] EMPTY_SHORT_ARRAY = new short[0];
private ByteBuffer data;
private final TableOfContents tableOfContents = new TableOfContents();
private int nextSectionStart = 0;
private final StringTable strings = new StringTable();
private final TypeIndexToDescriptorIndexTable typeIds = new TypeIndexToDescriptorIndexTable();
private final TypeIndexToDescriptorTable typeNames = new TypeIndexToDescriptorTable();
private final ProtoIdTable protoIds = new ProtoIdTable();
private final FieldIdTable fieldIds = new FieldIdTable();
private final MethodIdTable methodIds = new MethodIdTable();
/**
* Creates a new dex that reads from {@code data}. It is an error to modify
* {@code data} after using it to create a dex buffer.
*/
public Dex(byte[] data) throws IOException {
this(ByteBuffer.wrap(data));
}
private Dex(ByteBuffer data) throws IOException {
this.data = data;
this.data.order(ByteOrder.LITTLE_ENDIAN);
this.tableOfContents.readFrom(this);
}
/**
* Creates a new empty dex of the specified size.
*/
public Dex(int byteCount) throws IOException {
this.data = ByteBuffer.wrap(new byte[byteCount]);
this.data.order(ByteOrder.LITTLE_ENDIAN);
}
/**
* Creates a new dex buffer of the dex in {@code in}, and closes {@code in}.
*/
public Dex(InputStream in) throws IOException {
try {
loadFrom(in);
} finally {
in.close();
}
}
/**
* Creates a new dex buffer from the dex file {@code file}.
*/
public Dex(File file) throws IOException {
if (FileUtils.hasArchiveSuffix(file.getName())) {
ZipFile zipFile = new ZipFile(file);
ZipEntry entry = zipFile.getEntry(DexFormat.DEX_IN_JAR_NAME);
if (entry != null) {
try (InputStream inputStream = zipFile.getInputStream(entry)) {
loadFrom(inputStream);
}
zipFile.close();
} else {
throw new DexException("Expected " + DexFormat.DEX_IN_JAR_NAME + " in " + file);
}
} else if (file.getName().endsWith(".dex")) {
try (InputStream inputStream = new FileInputStream(file)) {
loadFrom(inputStream);
}
} else {
throw new DexException("unknown output extension: " + file);
}
}
/**
* It is the caller's responsibility to close {@code in}.
*/
private void loadFrom(InputStream in) throws IOException {
ByteArrayOutputStream bytesOut = new ByteArrayOutputStream();
byte[] buffer = new byte[8192];
int count;
while ((count = in.read(buffer)) != -1) {
bytesOut.write(buffer, 0, count);
}
this.data = ByteBuffer.wrap(bytesOut.toByteArray());
this.data.order(ByteOrder.LITTLE_ENDIAN);
this.tableOfContents.readFrom(this);
}
private static void checkBounds(int index, int length) {
if (index < 0 || index >= length) {
throw new IndexOutOfBoundsException("index:" + index + ", length=" + length);
}
}
public void writeTo(OutputStream out) throws IOException {
byte[] buffer = new byte[8192];
ByteBuffer data = this.data.duplicate(); // positioned ByteBuffers aren't thread safe
data.clear();
while (data.hasRemaining()) {
int count = Math.min(buffer.length, data.remaining());
data.get(buffer, 0, count);
out.write(buffer, 0, count);
}
}
public void writeTo(File dexOut) throws IOException {
try (OutputStream out = new FileOutputStream(dexOut)) {
writeTo(out);
}
}
public TableOfContents getTableOfContents() {
return tableOfContents;
}
public Section open(int position) {
if (position < 0 || position >= data.capacity()) {
throw new IllegalArgumentException("position=" + position
+ " length=" + data.capacity());
}
ByteBuffer sectionData = data.duplicate();
sectionData.order(ByteOrder.LITTLE_ENDIAN); // necessary?
sectionData.position(position);
sectionData.limit(data.capacity());
return new Section("section", sectionData);
}
public Section appendSection(int maxByteCount, String name) {
if ((maxByteCount & 3) != 0) {
throw new IllegalStateException("Not four byte aligned!");
}
int limit = nextSectionStart + maxByteCount;
ByteBuffer sectionData = data.duplicate();
sectionData.order(ByteOrder.LITTLE_ENDIAN); // necessary?
sectionData.position(nextSectionStart);
sectionData.limit(limit);
Section result = new Section(name, sectionData);
nextSectionStart = limit;
return result;
}
public int getLength() {
return data.capacity();
}
public int getNextSectionStart() {
return nextSectionStart;
}
/**
* Returns a copy of the the bytes of this dex.
*/
public byte[] getBytes() {
ByteBuffer data = this.data.duplicate(); // positioned ByteBuffers aren't thread safe
byte[] result = new byte[data.capacity()];
data.position(0);
data.get(result);
return result;
}
public List<String> strings() {
return strings;
}
public List<Integer> typeIds() {
return typeIds;
}
public List<String> typeNames() {
return typeNames;
}
public List<ProtoId> protoIds() {
return protoIds;
}
public List<FieldId> fieldIds() {
return fieldIds;
}
public List<MethodId> methodIds() {
return methodIds;
}
public Iterable<ClassDef> classDefs() {
return new ClassDefIterable();
}
public TypeList readTypeList(int offset) {
if (offset == 0) {
return TypeList.EMPTY;
}
return open(offset).readTypeList();
}
public ClassData readClassData(ClassDef classDef) {
int offset = classDef.getClassDataOffset();
if (offset == 0) {
throw new IllegalArgumentException("offset == 0");
}
return open(offset).readClassData();
}
public Code readCode(ClassData.Method method) {
int offset = method.getCodeOffset();
if (offset == 0) {
throw new IllegalArgumentException("offset == 0");
}
return open(offset).readCode();
}
/**
* Returns the signature of all but the first 32 bytes of this dex. The
* first 32 bytes of dex files are not specified to be included in the
* signature.
*/
public byte[] computeSignature() throws IOException {
MessageDigest digest;
try {
digest = MessageDigest.getInstance("SHA-1");
} catch (NoSuchAlgorithmException e) {
throw new AssertionError();
}
byte[] buffer = new byte[8192];
ByteBuffer data = this.data.duplicate(); // positioned ByteBuffers aren't thread safe
data.limit(data.capacity());
data.position(SIGNATURE_OFFSET + SIGNATURE_SIZE);
while (data.hasRemaining()) {
int count = Math.min(buffer.length, data.remaining());
data.get(buffer, 0, count);
digest.update(buffer, 0, count);
}
return digest.digest();
}
/**
* Returns the checksum of all but the first 12 bytes of {@code dex}.
*/
public int computeChecksum() throws IOException {
Adler32 adler32 = new Adler32();
byte[] buffer = new byte[8192];
ByteBuffer data = this.data.duplicate(); // positioned ByteBuffers aren't thread safe
data.limit(data.capacity());
data.position(CHECKSUM_OFFSET + CHECKSUM_SIZE);
while (data.hasRemaining()) {
int count = Math.min(buffer.length, data.remaining());
data.get(buffer, 0, count);
adler32.update(buffer, 0, count);
}
return (int) adler32.getValue();
}
/**
* Generates the signature and checksum of the dex file {@code out} and
* writes them to the file.
*/
public void writeHashes() throws IOException {
open(SIGNATURE_OFFSET).write(computeSignature());
open(CHECKSUM_OFFSET).writeInt(computeChecksum());
}
/**
* Look up a descriptor index from a type index. Cheaper than:
* {@code open(tableOfContents.typeIds.off + (index * SizeOf.TYPE_ID_ITEM)).readInt();}
*/
public int descriptorIndexFromTypeIndex(int typeIndex) {
checkBounds(typeIndex, tableOfContents.typeIds.size);
int position = tableOfContents.typeIds.off + (SizeOf.TYPE_ID_ITEM * typeIndex);
return data.getInt(position);
}
public final class Section implements ByteInput, ByteOutput {
private final String name;
private final ByteBuffer data;
private final int initialPosition;
private Section(String name, ByteBuffer data) {
this.name = name;
this.data = data;
this.initialPosition = data.position();
}
public int getPosition() {
return data.position();
}
public int readInt() {
return data.getInt();
}
public short readShort() {
return data.getShort();
}
public int readUnsignedShort() {
return readShort() & 0xffff;
}
@Override
public byte readByte() {
return data.get();
}
public byte[] readByteArray(int length) {
byte[] result = new byte[length];
data.get(result);
return result;
}
public short[] readShortArray(int length) {
if (length == 0) {
return EMPTY_SHORT_ARRAY;
}
short[] result = new short[length];
for (int i = 0; i < length; i++) {
result[i] = readShort();
}
return result;
}
public int readUleb128() {
return Leb128.readUnsignedLeb128(this);
}
public int readUleb128p1() {
return Leb128.readUnsignedLeb128(this) - 1;
}
public int readSleb128() {
return Leb128.readSignedLeb128(this);
}
public void writeUleb128p1(int i) {
writeUleb128(i + 1);
}
public TypeList readTypeList() {
int size = readInt();
short[] types = readShortArray(size);
alignToFourBytes();
return new TypeList(Dex.this, types);
}
public String readString() {
int offset = readInt();
int savedPosition = data.position();
int savedLimit = data.limit();
data.position(offset);
data.limit(data.capacity());
try {
int expectedLength = readUleb128();
String result = Mutf8.decode(this, new char[expectedLength]);
if (result.length() != expectedLength) {
throw new DexException("Declared length " + expectedLength
+ " doesn't match decoded length of " + result.length());
}
return result;
} catch (UTFDataFormatException e) {
throw new DexException(e);
} finally {
data.position(savedPosition);
data.limit(savedLimit);
}
}
public FieldId readFieldId() {
int declaringClassIndex = readUnsignedShort();
int typeIndex = readUnsignedShort();
int nameIndex = readInt();
return new FieldId(Dex.this, declaringClassIndex, typeIndex, nameIndex);
}
public MethodId readMethodId() {
int declaringClassIndex = readUnsignedShort();
int protoIndex = readUnsignedShort();
int nameIndex = readInt();
return new MethodId(Dex.this, declaringClassIndex, protoIndex, nameIndex);
}
public ProtoId readProtoId() {
int shortyIndex = readInt();
int returnTypeIndex = readInt();
int parametersOffset = readInt();
return new ProtoId(Dex.this, shortyIndex, returnTypeIndex, parametersOffset);
}
public CallSiteId readCallSiteId() {
int offset = readInt();
return new CallSiteId(Dex.this, offset);
}
public MethodHandle readMethodHandle() {
MethodHandleType methodHandleType = MethodHandleType.fromValue(readUnsignedShort());
int unused1 = readUnsignedShort();
int fieldOrMethodId = readUnsignedShort();
int unused2 = readUnsignedShort();
return new MethodHandle(Dex.this, methodHandleType, unused1, fieldOrMethodId, unused2);
}
public ClassDef readClassDef() {
int offset = getPosition();
int type = readInt();
int accessFlags = readInt();
int supertype = readInt();
int interfacesOffset = readInt();
int sourceFileIndex = readInt();
int annotationsOffset = readInt();
int classDataOffset = readInt();
int staticValuesOffset = readInt();
return new ClassDef(Dex.this, offset, type, accessFlags, supertype,
interfacesOffset, sourceFileIndex, annotationsOffset, classDataOffset,
staticValuesOffset);
}
private Code readCode() {
int registersSize = readUnsignedShort();
int insSize = readUnsignedShort();
int outsSize = readUnsignedShort();
int triesSize = readUnsignedShort();
int debugInfoOffset = readInt();
int instructionsSize = readInt();
short[] instructions = readShortArray(instructionsSize);
Try[] tries;
CatchHandler[] catchHandlers;
if (triesSize > 0) {
if (instructions.length % 2 == 1) {
readShort(); // padding
}
/*
* We can't read the tries until we've read the catch handlers.
* Unfortunately they're in the opposite order in the dex file
* so we need to read them out-of-order.
*/
Section triesSection = open(data.position());
skip(triesSize * SizeOf.TRY_ITEM);
catchHandlers = readCatchHandlers();
tries = triesSection.readTries(triesSize, catchHandlers);
} else {
tries = new Try[0];
catchHandlers = new CatchHandler[0];
}
return new Code(registersSize, insSize, outsSize, debugInfoOffset, instructions,
tries, catchHandlers);
}
private CatchHandler[] readCatchHandlers() {
int baseOffset = data.position();
int catchHandlersSize = readUleb128();
CatchHandler[] result = new CatchHandler[catchHandlersSize];
for (int i = 0; i < catchHandlersSize; i++) {
int offset = data.position() - baseOffset;
result[i] = readCatchHandler(offset);
}
return result;
}
private Try[] readTries(int triesSize, CatchHandler[] catchHandlers) {
Try[] result = new Try[triesSize];
for (int i = 0; i < triesSize; i++) {
int startAddress = readInt();
int instructionCount = readUnsignedShort();
int handlerOffset = readUnsignedShort();
int catchHandlerIndex = findCatchHandlerIndex(catchHandlers, handlerOffset);
result[i] = new Try(startAddress, instructionCount, catchHandlerIndex);
}
return result;
}
private int findCatchHandlerIndex(CatchHandler[] catchHandlers, int offset) {
for (int i = 0; i < catchHandlers.length; i++) {
CatchHandler catchHandler = catchHandlers[i];
if (catchHandler.getOffset() == offset) {
return i;
}
}
throw new IllegalArgumentException();
}
private CatchHandler readCatchHandler(int offset) {
int size = readSleb128();
int handlersCount = Math.abs(size);
int[] typeIndexes = new int[handlersCount];
int[] addresses = new int[handlersCount];
for (int i = 0; i < handlersCount; i++) {
typeIndexes[i] = readUleb128();
addresses[i] = readUleb128();
}
int catchAllAddress = size <= 0 ? readUleb128() : -1;
return new CatchHandler(typeIndexes, addresses, catchAllAddress, offset);
}
private ClassData readClassData() {
int staticFieldsSize = readUleb128();
int instanceFieldsSize = readUleb128();
int directMethodsSize = readUleb128();
int virtualMethodsSize = readUleb128();
ClassData.Field[] staticFields = readFields(staticFieldsSize);
ClassData.Field[] instanceFields = readFields(instanceFieldsSize);
ClassData.Method[] directMethods = readMethods(directMethodsSize);
ClassData.Method[] virtualMethods = readMethods(virtualMethodsSize);
return new ClassData(staticFields, instanceFields, directMethods, virtualMethods);
}
private ClassData.Field[] readFields(int count) {
ClassData.Field[] result = new ClassData.Field[count];
int fieldIndex = 0;
for (int i = 0; i < count; i++) {
fieldIndex += readUleb128(); // field index diff
int accessFlags = readUleb128();
result[i] = new ClassData.Field(fieldIndex, accessFlags);
}
return result;
}
private ClassData.Method[] readMethods(int count) {
ClassData.Method[] result = new ClassData.Method[count];
int methodIndex = 0;
for (int i = 0; i < count; i++) {
methodIndex += readUleb128(); // method index diff
int accessFlags = readUleb128();
int codeOff = readUleb128();
result[i] = new ClassData.Method(methodIndex, accessFlags, codeOff);
}
return result;
}
/**
* Returns a byte array containing the bytes from {@code start} to this
* section's current position.
*/
private byte[] getBytesFrom(int start) {
int end = data.position();
byte[] result = new byte[end - start];
data.position(start);
data.get(result);
return result;
}
public Annotation readAnnotation() {
byte visibility = readByte();
int start = data.position();
new EncodedValueReader(this, EncodedValueReader.ENCODED_ANNOTATION).skipValue();
return new Annotation(Dex.this, visibility, new EncodedValue(getBytesFrom(start)));
}
public EncodedValue readEncodedArray() {
int start = data.position();
new EncodedValueReader(this, EncodedValueReader.ENCODED_ARRAY).skipValue();
return new EncodedValue(getBytesFrom(start));
}
public void skip(int count) {
if (count < 0) {
throw new IllegalArgumentException();
}
data.position(data.position() + count);
}
/**
* Skips bytes until the position is aligned to a multiple of 4.
*/
public void alignToFourBytes() {
data.position((data.position() + 3) & ~3);
}
/**
* Writes 0x00 until the position is aligned to a multiple of 4.
*/
public void alignToFourBytesWithZeroFill() {
while ((data.position() & 3) != 0) {
data.put((byte) 0);
}
}
public void assertFourByteAligned() {
if ((data.position() & 3) != 0) {
throw new IllegalStateException("Not four byte aligned!");
}
}
public void write(byte[] bytes) {
this.data.put(bytes);
}
@Override
public void writeByte(int b) {
data.put((byte) b);
}
public void writeShort(short i) {
data.putShort(i);
}
public void writeUnsignedShort(int i) {
short s = (short) i;
if (i != (s & 0xffff)) {
throw new IllegalArgumentException("Expected an unsigned short: " + i);
}
writeShort(s);
}
public void write(short[] shorts) {
for (short s : shorts) {
writeShort(s);
}
}
public void writeInt(int i) {
data.putInt(i);
}
public void writeUleb128(int i) {
try {
Leb128.writeUnsignedLeb128(this, i);
} catch (ArrayIndexOutOfBoundsException e) {
throw new DexException("Section limit " + data.limit() + " exceeded by " + name);
}
}
public void writeSleb128(int i) {
try {
Leb128.writeSignedLeb128(this, i);
} catch (ArrayIndexOutOfBoundsException e) {
throw new DexException("Section limit " + data.limit() + " exceeded by " + name);
}
}
public void writeStringData(String value) {
try {
int length = value.length();
writeUleb128(length);
write(Mutf8.encode(value));
writeByte(0);
} catch (UTFDataFormatException e) {
throw new AssertionError();
}
}
public void writeTypeList(TypeList typeList) {
short[] types = typeList.getTypes();
writeInt(types.length);
for (short type : types) {
writeShort(type);
}
alignToFourBytesWithZeroFill();
}
/**
* Returns the number of bytes used by this section.
*/
public int used() {
return data.position() - initialPosition;
}
}
private final class StringTable extends AbstractList<String> implements RandomAccess {
@Override
public String get(int index) {
checkBounds(index, tableOfContents.stringIds.size);
return open(tableOfContents.stringIds.off + (index * SizeOf.STRING_ID_ITEM))
.readString();
}
@Override
public int size() {
return tableOfContents.stringIds.size;
}
}
private final class TypeIndexToDescriptorIndexTable extends AbstractList<Integer>
implements RandomAccess {
@Override
public Integer get(int index) {
return descriptorIndexFromTypeIndex(index);
}
@Override
public int size() {
return tableOfContents.typeIds.size;
}
}
private final class TypeIndexToDescriptorTable extends AbstractList<String>
implements RandomAccess {
@Override
public String get(int index) {
return strings.get(descriptorIndexFromTypeIndex(index));
}
@Override
public int size() {
return tableOfContents.typeIds.size;
}
}
private final class ProtoIdTable extends AbstractList<ProtoId> implements RandomAccess {
@Override
public ProtoId get(int index) {
checkBounds(index, tableOfContents.protoIds.size);
return open(tableOfContents.protoIds.off + (SizeOf.PROTO_ID_ITEM * index))
.readProtoId();
}
@Override
public int size() {
return tableOfContents.protoIds.size;
}
}
private final class FieldIdTable extends AbstractList<FieldId> implements RandomAccess {
@Override
public FieldId get(int index) {
checkBounds(index, tableOfContents.fieldIds.size);
return open(tableOfContents.fieldIds.off + (SizeOf.MEMBER_ID_ITEM * index))
.readFieldId();
}
@Override
public int size() {
return tableOfContents.fieldIds.size;
}
}
private final class MethodIdTable extends AbstractList<MethodId> implements RandomAccess {
@Override
public MethodId get(int index) {
checkBounds(index, tableOfContents.methodIds.size);
return open(tableOfContents.methodIds.off + (SizeOf.MEMBER_ID_ITEM * index))
.readMethodId();
}
@Override
public int size() {
return tableOfContents.methodIds.size;
}
}
private final class ClassDefIterator implements Iterator<ClassDef> {
private final Dex.Section in = open(tableOfContents.classDefs.off);
private int count = 0;
@Override
public boolean hasNext() {
return count < tableOfContents.classDefs.size;
}
@Override
public ClassDef next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
count++;
return in.readClassDef();
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
}
private final class ClassDefIterable implements Iterable<ClassDef> {
@Override
public Iterator<ClassDef> iterator() {
return !tableOfContents.classDefs.exists()
? Collections.<ClassDef>emptySet().iterator()
: new ClassDefIterator();
}
}
}