ReVanced/smali
1
0
Fork 0
mirror of https://github.com/revanced/smali.git synced 2025-05-09 10:54:29 +02:00
Code Issues Packages Projects Releases Wiki Activity

Centralize debug info related parsing into DebugInfo class

Browse Source
This commit is contained in:
Ben Gruver 2012-10-28 14:02:31 -07:00
parent 754b3c4dc0
commit b11a01715a
3 changed files with 302 additions and 289 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
dexlib2/src/main/java/org/jf/dexlib2/dexbacked/DexBackedMethodImplementation.java
View File

@ -33,7 +33,7 @@ package org.jf.dexlib2.dexbacked;
import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableList;
import org.jf.dexlib2.dexbacked.instruction.DexBackedInstruction; import org.jf.dexlib2.dexbacked.instruction.DexBackedInstruction;
import org.jf.dexlib2.dexbacked.util.DebugItemList; import org.jf.dexlib2.dexbacked.util.DebugInfo;
import org.jf.dexlib2.dexbacked.util.FixedSizeList; import org.jf.dexlib2.dexbacked.util.FixedSizeList;
import org.jf.dexlib2.dexbacked.util.VariableSizeList; import org.jf.dexlib2.dexbacked.util.VariableSizeList;
import org.jf.dexlib2.iface.Annotation; import org.jf.dexlib2.iface.Annotation;
@ -56,6 +56,7 @@ public class DexBackedMethodImplementation implements MethodImplementation {
public final int registerCount; public final int registerCount;
@Nonnull public final ImmutableList<? extends Instruction> instructions; @Nonnull public final ImmutableList<? extends Instruction> instructions;
@Nonnull public final DebugInfo debugInfo;
// code_item offsets // code_item offsets
private static final int TRIES_SIZE_OFFSET = 6; private static final int TRIES_SIZE_OFFSET = 6;
@ -72,8 +73,8 @@ public class DexBackedMethodImplementation implements MethodImplementation {
this.method = method; this.method = method;
this.codeOffset = codeOffset; this.codeOffset = codeOffset;
this.registerCount = dexBuf.readUshort(codeOffset); this.registerCount = dexBuf.readUshort(codeOffset);
this.instructions = buildInstructionList();
instructions = buildInstructionList(); this.debugInfo = DebugInfo.newOrEmpty(dexBuf, dexBuf.readSmallUint(codeOffset + DEBUG_OFFSET_OFFSET), this);
} }
@Override public int getRegisterCount() { return registerCount; } @Override public int getRegisterCount() { return registerCount; }
@ -110,11 +111,7 @@ public class DexBackedMethodImplementation implements MethodImplementation {
@Nonnull @Nonnull
@Override @Override
public Iterable<? extends DebugItem> getDebugItems() { public Iterable<? extends DebugItem> getDebugItems() {
final int debugInfoOffset = dexBuf.readSmallUint(codeOffset + DEBUG_OFFSET_OFFSET); return debugInfo;
if (debugInfoOffset > 0) {
return new DebugItemList(dexBuf, debugInfoOffset, this);
}
return ImmutableList.of();
} }
@Nonnull @Nonnull
@ -135,49 +132,7 @@ public class DexBackedMethodImplementation implements MethodImplementation {
return ImmutableList.copyOf(instructions); return ImmutableList.copyOf(instructions);
} }
//TODO: reading the method params from the debug_info_item should probably be centralized with other debug stuff
@Nullable
public VariableSizeList<MethodParameter> getParametersWithNamesOrNull() {
final int debugInfoOffset = dexBuf.readSmallUint(codeOffset + DEBUG_OFFSET_OFFSET);
if (debugInfoOffset > 0) {
DexReader reader = dexBuf.readerAt(debugInfoOffset);
reader.skipUleb128();
final int parameterNameCount = reader.readSmallUleb128();
final List<? extends MethodParameter> methodParametersWithoutNames = method.getParametersWithoutNames();
//TODO: make sure dalvik doesn't allow more parameter names than we have parameters
return new VariableSizeList<MethodParameter>(dexBuf, reader.getOffset()) {
@Nonnull
@Override
protected MethodParameter readItem(@Nonnull DexReader reader, int index) {
final MethodParameter methodParameter = methodParametersWithoutNames.get(index);
String _name = null;
if (index < parameterNameCount) {
_name = reader.getOptionalString(reader.readSmallUleb128() - 1);
}
final String name = _name;
return new MethodParameter() {
@Nonnull @Override public String getType() { return methodParameter.getType(); }
@Nullable @Override public String getName() { return name; }
@Nullable @Override public String getSignature() { return methodParameter.getSignature();}
@Nonnull @Override public List<? extends Annotation> getAnnotations() {
return methodParameter.getAnnotations();
}
};
}
@Override public int size() { return methodParametersWithoutNames.size(); }
};
}
return null;
}
public List<? extends MethodParameter> getParametersWithNames() { public List<? extends MethodParameter> getParametersWithNames() {
List<MethodParameter> parameters = getParametersWithNamesOrNull(); return debugInfo.getParametersWithNames();
if (parameters != null) {
return parameters;
}
return method.getParametersWithoutNames();
} }
} }

296
dexlib2/src/main/java/org/jf/dexlib2/dexbacked/util/DebugInfo.java Normal file
View File

@ -0,0 +1,296 @@
/*
* Copyright 2012, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.jf.dexlib2.dexbacked.util;
import com.google.common.collect.Iterators;
import org.jf.dexlib2.DebugItemType;
import org.jf.dexlib2.dexbacked.DexBackedMethod;
import org.jf.dexlib2.dexbacked.DexBackedMethodImplementation;
import org.jf.dexlib2.dexbacked.DexBuffer;
import org.jf.dexlib2.dexbacked.DexReader;
import org.jf.dexlib2.iface.Annotation;
import org.jf.dexlib2.iface.MethodParameter;
import org.jf.dexlib2.iface.debug.DebugItem;
import org.jf.dexlib2.iface.debug.EndLocal;
import org.jf.dexlib2.iface.debug.LocalInfo;
import org.jf.dexlib2.immutable.debug.*;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
public abstract class DebugInfo implements Iterable<DebugItem> {
@Nonnull public abstract List<? extends MethodParameter> getParametersWithNames();
public static DebugInfo newOrEmpty(@Nonnull DexBuffer dexBuf, int debugInfoOffset,
@Nonnull DexBackedMethodImplementation methodImpl) {
if (debugInfoOffset == 0) {
new EmptyDebugInfo(methodImpl.method);
}
return new DebugInfoImpl(dexBuf, debugInfoOffset, methodImpl);
}
private static class EmptyDebugInfo extends DebugInfo {
@Nonnull private final DexBackedMethod method;
public EmptyDebugInfo(@Nonnull DexBackedMethod method) { this.method = method; }
@Nonnull @Override public Iterator<DebugItem> iterator() { return Iterators.emptyIterator(); }
@Nonnull @Override public List<? extends MethodParameter> getParametersWithNames() {
return method.getParametersWithoutNames();
}
}
private static class DebugInfoImpl extends DebugInfo {
@Nonnull public final DexBuffer dexBuf;
private final int debugInfoOffset;
@Nonnull private final DexBackedMethodImplementation methodImpl;
public DebugInfoImpl(@Nonnull DexBuffer dexBuf,
int debugInfoOffset,
@Nonnull DexBackedMethodImplementation methodImpl) {
this.dexBuf = dexBuf;
this.debugInfoOffset = debugInfoOffset;
this.methodImpl = methodImpl;
}
private static final LocalInfo EMPTY_LOCAL_INFO = new LocalInfo() {
@Nullable @Override public String getName() { return null; }
@Nullable @Override public String getType() { return null; }
@Nullable @Override public String getSignature() { return null; }
};
@Nonnull
@Override
public Iterator<DebugItem> iterator() {
DexReader initialReader = dexBuf.readerAt(debugInfoOffset);
// TODO: this unsigned value could legitimally be > MAX_INT
final int lineNumberStart = initialReader.readSmallUleb128();
int registerCount = methodImpl.getRegisterCount();
//TODO: does dalvik allow references to invalid registers?
final LocalInfo[] locals = new LocalInfo[registerCount];
Arrays.fill(locals, EMPTY_LOCAL_INFO);
VariableSizeList<? extends MethodParameter> parameters = getParametersWithNames();
final VariableSizeList<? extends MethodParameter>.Iterator parameterIterator = parameters.listIterator();
{ // local scope for i
int i=0;
while (parameterIterator.hasNext()) {
locals[i++] = parameterIterator.next();
}
}
if (parameters.size() < registerCount) {
// we need to push the parameter locals back to their appropriate register
int localIndex = registerCount-1;
for (int i=parameters.size()-1; i>-1; i--) {
LocalInfo currentLocal = locals[i];
locals[localIndex] = currentLocal;
locals[i] = EMPTY_LOCAL_INFO;
String type = currentLocal.getType();
localIndex--;
if (type != null && (type.equals("J") || type.equals("D"))) {
localIndex--;
}
}
}
return new Iterator<DebugItem>() {
@Nonnull private DexReader reader = dexBuf.readerAt(parameterIterator.getReaderOffset());
private boolean finished = false;
private int codeAddress = 0;
private int lineNumber = lineNumberStart;
@Nullable private DebugItem nextItem;
@Nullable
protected DebugItem readItem() {
if (finished) {
return null;
}
while (true) {
int next = reader.readUbyte();
switch (next) {
case DebugItemType.END_SEQUENCE: {
finished = true;
return null;
}
case DebugItemType.ADVANCE_PC: {
int addressDiff = reader.readSmallUleb128();
codeAddress += addressDiff;
continue;
}
case DebugItemType.ADVANCE_LINE: {
int lineDiff = reader.readSleb128();
lineNumber += lineDiff;
continue;
}
case DebugItemType.START_LOCAL: {
int register = reader.readSmallUleb128();
String name = dexBuf.getOptionalString(reader.readSmallUleb128() - 1);
String type = dexBuf.getOptionalType(reader.readSmallUleb128() - 1);
ImmutableStartLocal startLocal =
new ImmutableStartLocal(codeAddress, register, name, type, null);
locals[register] = startLocal;
return startLocal;
}
case DebugItemType.START_LOCAL_EXTENDED: {
int register = reader.readSmallUleb128();
String name = dexBuf.getOptionalString(reader.readSmallUleb128() - 1);
String type = dexBuf.getOptionalType(reader.readSmallUleb128() - 1);
String signature = dexBuf.getOptionalString(reader.readSmallUleb128() - 1);
ImmutableStartLocal startLocal =
new ImmutableStartLocal(codeAddress, register, name, type, signature);
locals[register] = startLocal;
return startLocal;
}
case DebugItemType.END_LOCAL: {
int register = reader.readSmallUleb128();
LocalInfo localInfo = locals[register];
boolean replaceLocalInTable = true;
if (localInfo instanceof EndLocal) {
localInfo = EMPTY_LOCAL_INFO;
// don't replace the local info in locals. The new EndLocal won't have any info at all,
// and we dont want to wipe out what's there, so that it is available for a subsequent
// RestartLocal
replaceLocalInTable = false;
}
ImmutableEndLocal endLocal =
new ImmutableEndLocal(codeAddress, register, localInfo.getName(),
localInfo.getType(), localInfo.getSignature());
if (replaceLocalInTable) {
locals[register] = endLocal;
}
return endLocal;
}
case DebugItemType.RESTART_LOCAL: {
int register = reader.readSmallUleb128();
LocalInfo localInfo = locals[register];
ImmutableRestartLocal restartLocal =
new ImmutableRestartLocal(codeAddress, register, localInfo.getName(),
localInfo.getType(), localInfo.getSignature());
locals[register] = restartLocal;
return restartLocal;
}
case DebugItemType.PROLOGUE_END: {
return new ImmutablePrologueEnd(codeAddress);
}
case DebugItemType.EPILOGUE_BEGIN: {
return new ImmutableEpilogueBegin(codeAddress);
}
case DebugItemType.SET_SOURCE_FILE: {
String sourceFile = dexBuf.getOptionalString(reader.readSmallUleb128() - 1);
return new ImmutableSetSourceFile(codeAddress, sourceFile);
}
default: {
int base = ((next & 0xFF) - 0x0A);
codeAddress += base / 15;
lineNumber += (base % 15) - 4;
return new ImmutableLineNumber(codeAddress, lineNumber);
}
}
}
}
@Override
public boolean hasNext() {
if (finished || nextItem != null) {
return false;
}
nextItem = readItem();
return nextItem != null;
}
@Nonnull
@Override
public DebugItem next() {
if (finished) {
throw new NoSuchElementException();
}
if (nextItem == null) {
DebugItem ret = readItem();
if (ret == null) {
throw new NoSuchElementException();
}
return ret;
}
DebugItem ret = nextItem;
nextItem = null;
return ret;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
};
}
@Nonnull
@Override
public VariableSizeList<MethodParameter> getParametersWithNames() {
DexReader reader = dexBuf.readerAt(debugInfoOffset);
reader.skipUleb128();
final int parameterNameCount = reader.readSmallUleb128();
final List<? extends MethodParameter> methodParametersWithoutNames =
methodImpl.method.getParametersWithoutNames();
//TODO: make sure dalvik doesn't allow more parameter names than we have parameters
return new VariableSizeList<MethodParameter>(dexBuf, reader.getOffset()) {
@Nonnull
@Override
protected MethodParameter readItem(@Nonnull DexReader reader, int index) {
final MethodParameter methodParameter = methodParametersWithoutNames.get(index);
String _name = null;
if (index < parameterNameCount) {
_name = reader.getOptionalString(reader.readSmallUleb128() - 1);
}
final String name = _name;
return new MethodParameter() {
@Nonnull @Override public String getType() { return methodParameter.getType(); }
@Nullable @Override public String getName() { return name; }
@Nullable @Override public String getSignature() { return methodParameter.getSignature();}
@Nonnull @Override public List<? extends Annotation> getAnnotations() {
return methodParameter.getAnnotations();
}
};
}
@Override public int size() { return methodParametersWithoutNames.size(); }
};
}
}
}

238
dexlib2/src/main/java/org/jf/dexlib2/dexbacked/util/DebugItemList.java
View File

@ -1,238 +0,0 @@
/*
* Copyright 2012, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.jf.dexlib2.dexbacked.util;
import org.jf.dexlib2.DebugItemType;
import org.jf.dexlib2.dexbacked.DexBackedMethodImplementation;
import org.jf.dexlib2.dexbacked.DexBuffer;
import org.jf.dexlib2.dexbacked.DexReader;
import org.jf.dexlib2.iface.MethodParameter;
import org.jf.dexlib2.iface.debug.DebugItem;
import org.jf.dexlib2.iface.debug.EndLocal;
import org.jf.dexlib2.iface.debug.LocalInfo;
import org.jf.dexlib2.immutable.debug.*;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.Arrays;
import java.util.Iterator;
import java.util.NoSuchElementException;
public class DebugItemList implements Iterable<DebugItem> {
@Nonnull public final DexBuffer dexBuf;
private final int debugInfoOffset;
@Nonnull private final DexBackedMethodImplementation methodImpl;
public DebugItemList(@Nonnull DexBuffer dexBuf,
int debugInfoOffset,
@Nonnull DexBackedMethodImplementation methodImpl) {
this.dexBuf = dexBuf;
this.debugInfoOffset = debugInfoOffset;
this.methodImpl = methodImpl;
}
private static final LocalInfo EMPTY_LOCAL_INFO = new LocalInfo() {
@Nullable @Override public String getName() { return null; }
@Nullable @Override public String getType() { return null; }
@Nullable @Override public String getSignature() { return null; }
};
@Nonnull
@Override
public Iterator<DebugItem> iterator() {
DexReader initialReader = dexBuf.readerAt(debugInfoOffset);
// TODO: this unsigned value could legitimally be > MAX_INT
final int lineNumberStart = initialReader.readSmallUleb128();
int registerCount = methodImpl.getRegisterCount();
//TODO: does dalvik allow references to invalid registers?
final LocalInfo[] locals = new LocalInfo[registerCount];
Arrays.fill(locals, EMPTY_LOCAL_INFO);
// getParametersWithNames returns a VariableSizeList when debug info is present
VariableSizeList<? extends MethodParameter> parameters = methodImpl.getParametersWithNamesOrNull();
assert parameters != null;
final VariableSizeList<? extends MethodParameter>.Iterator parameterIterator = parameters.listIterator();
{ // local scope for i
int i=0;
while (parameterIterator.hasNext()) {
locals[i++] = parameterIterator.next();
}
}
if (parameters.size() < registerCount) {
// we need to push the parameter locals back to their appropriate register
int localIndex = registerCount-1;
for (int i=parameters.size()-1; i>-1; i--) {
LocalInfo currentLocal = locals[i];
locals[localIndex] = currentLocal;
locals[i] = EMPTY_LOCAL_INFO;
String type = currentLocal.getType();
localIndex--;
if (type != null && (type.equals("J") || type.equals("D"))) {
localIndex--;
}
}
}
return new Iterator<DebugItem>() {
@Nonnull private DexReader reader = dexBuf.readerAt(parameterIterator.getReaderOffset());
private boolean finished = false;
private int codeAddress = 0;
private int lineNumber = lineNumberStart;
@Nullable private DebugItem nextItem;
@Nullable
protected DebugItem readItem() {
if (finished) {
return null;
}
while (true) {
int next = reader.readUbyte();
switch (next) {
case DebugItemType.END_SEQUENCE: {
finished = true;
return null;
}
case DebugItemType.ADVANCE_PC: {
int addressDiff = reader.readSmallUleb128();
codeAddress += addressDiff;
continue;
}
case DebugItemType.ADVANCE_LINE: {
int lineDiff = reader.readSleb128();
lineNumber += lineDiff;
continue;
}
case DebugItemType.START_LOCAL: {
int register = reader.readSmallUleb128();
String name = dexBuf.getOptionalString(reader.readSmallUleb128() - 1);
String type = dexBuf.getOptionalType(reader.readSmallUleb128() - 1);
ImmutableStartLocal startLocal =
new ImmutableStartLocal(codeAddress, register, name, type, null);
locals[register] = startLocal;
return startLocal;
}
case DebugItemType.START_LOCAL_EXTENDED: {
int register = reader.readSmallUleb128();
String name = dexBuf.getOptionalString(reader.readSmallUleb128() - 1);
String type = dexBuf.getOptionalType(reader.readSmallUleb128() - 1);
String signature = dexBuf.getOptionalString(reader.readSmallUleb128() - 1);
ImmutableStartLocal startLocal =
new ImmutableStartLocal(codeAddress, register, name, type, signature);
locals[register] = startLocal;
return startLocal;
}
case DebugItemType.END_LOCAL: {
int register = reader.readSmallUleb128();
LocalInfo localInfo = locals[register];
boolean replaceLocalInTable = true;
if (localInfo instanceof EndLocal) {
localInfo = EMPTY_LOCAL_INFO;
// don't replace the local info in locals. The new EndLocal won't have any info at all,
// and we dont want to wipe out what's there, so that it is available for a subsequent
// RestartLocal
replaceLocalInTable = false;
}
ImmutableEndLocal endLocal =
new ImmutableEndLocal(codeAddress, register, localInfo.getName(),
localInfo.getType(), localInfo.getSignature());
if (replaceLocalInTable) {
locals[register] = endLocal;
}
return endLocal;
}
case DebugItemType.RESTART_LOCAL: {
int register = reader.readSmallUleb128();
LocalInfo localInfo = locals[register];
ImmutableRestartLocal restartLocal =
new ImmutableRestartLocal(codeAddress, register, localInfo.getName(),
localInfo.getType(), localInfo.getSignature());
locals[register] = restartLocal;
return restartLocal;
}
case DebugItemType.PROLOGUE_END: {
return new ImmutablePrologueEnd(codeAddress);
}
case DebugItemType.EPILOGUE_BEGIN: {
return new ImmutableEpilogueBegin(codeAddress);
}
case DebugItemType.SET_SOURCE_FILE: {
String sourceFile = dexBuf.getOptionalString(reader.readSmallUleb128() - 1);
return new ImmutableSetSourceFile(codeAddress, sourceFile);
}
default: {
int base = ((next & 0xFF) - 0x0A);
codeAddress += base / 15;
lineNumber += (base % 15) - 4;
return new ImmutableLineNumber(codeAddress, lineNumber);
}
}
}
}
@Override
public boolean hasNext() {
if (finished || nextItem != null) {
return false;
}
nextItem = readItem();
return nextItem != null;
}
@Nonnull
@Override
public DebugItem next() {
if (finished) {
throw new NoSuchElementException();
}
if (nextItem == null) {
DebugItem ret = readItem();
if (ret == null) {
throw new NoSuchElementException();
}
return ret;
}
DebugItem ret = nextItem;
nextItem = null;
return ret;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
};
}
}