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package org.jf.dexlib2.dexbacked.util;
import com.google.common.collect.ImmutableSet;
import org.jf.dexlib2.AccessFlags;
import org.jf.dexlib2.DebugItemType;
import org.jf.dexlib2.dexbacked.DexBackedDexFile;
import org.jf.dexlib2.dexbacked.DexBackedMethod;
import org.jf.dexlib2.dexbacked.DexBackedMethodImplementation;
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;
public abstract class DebugInfo implements Iterable<DebugItem> {
/**
* Gets an iterator that yields the parameter names from the debug_info_item
*
* @param reader Optional. If provided, the reader must be positioned at the debug_info_item.parameters_size
* field, and will
* @return An iterator that yields the parameter names as strings
*/
@Nonnull public abstract Iterator<String> getParameterNames(@Nullable DexReader reader);
/**
* Calculate and return the private size of debuginfo.
*
* @return size in bytes
*/
public abstract int getSize();
public static DebugInfo newOrEmpty(@Nonnull DexBackedDexFile dexFile, int debugInfoOffset,
@Nonnull DexBackedMethodImplementation methodImpl) {
if (debugInfoOffset == 0) {
return EmptyDebugInfo.INSTANCE;
}
return new DebugInfoImpl(dexFile, debugInfoOffset, methodImpl);
}
private static class EmptyDebugInfo extends DebugInfo {
public static final EmptyDebugInfo INSTANCE = new EmptyDebugInfo();
private EmptyDebugInfo() {}
@Nonnull @Override public Iterator<DebugItem> iterator() {
return ImmutableSet.<DebugItem>of().iterator();
}
@Nonnull @Override public Iterator<String> getParameterNames(@Nullable DexReader reader) {
return ImmutableSet.<String>of().iterator();
}
@Override
public int getSize() {
return 0;
}
}
private static class DebugInfoImpl extends DebugInfo {
@Nonnull public final DexBackedDexFile dexFile;
private final int debugInfoOffset;
@Nonnull private final DexBackedMethodImplementation methodImpl;
public DebugInfoImpl(@Nonnull DexBackedDexFile dexFile,
int debugInfoOffset,
@Nonnull DexBackedMethodImplementation methodImpl) {
this.dexFile = dexFile;
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 reader = dexFile.readerAt(debugInfoOffset);
final int lineNumberStart = reader.readBigUleb128();
int registerCount = methodImpl.getRegisterCount();
//TODO: does dalvik allow references to invalid registers?
final LocalInfo[] locals = new LocalInfo[registerCount];
Arrays.fill(locals, EMPTY_LOCAL_INFO);
DexBackedMethod method = methodImpl.method;
// Create a MethodParameter iterator that uses our DexReader instance to read the parameter names.
// After we have finished iterating over the parameters, reader will "point to" the beginning of the
// debug instructions
final Iterator<? extends MethodParameter> parameterIterator =
new ParameterIterator(method.getParameterTypes(),
method.getParameterAnnotations(),
getParameterNames(reader));
// first, we grab all the parameters and temporarily store them at the beginning of locals,
// disregarding any wide types
int parameterIndex = 0;
if (!AccessFlags.STATIC.isSet(methodImpl.method.getAccessFlags())) {
// add the local info for the "this" parameter
locals[parameterIndex++] = new LocalInfo() {
@Override public String getName() { return "this"; }
@Override public String getType() { return methodImpl.method.getDefiningClass(); }
@Override public String getSignature() { return null; }
};
}
while (parameterIterator.hasNext()) {
locals[parameterIndex++] = parameterIterator.next();
}
if (parameterIndex < registerCount) {
// now, we push the parameter locals back to their appropriate register, starting from the end
int localIndex = registerCount-1;
while(--parameterIndex > -1) {
LocalInfo currentLocal = locals[parameterIndex];
String type = currentLocal.getType();
if (type != null && (type.equals("J") || type.equals("D"))) {
localIndex--;
if (localIndex == parameterIndex) {
// there's no more room to push, the remaining registers are already in the correct place
break;
}
}
locals[localIndex] = currentLocal;
locals[parameterIndex] = EMPTY_LOCAL_INFO;
localIndex--;
}
}
return new VariableSizeLookaheadIterator<DebugItem>(dexFile, reader.getOffset()) {
private int codeAddress = 0;
private int lineNumber = lineNumberStart;
@Nullable
protected DebugItem readNextItem(@Nonnull DexReader reader) {
while (true) {
int next = reader.readUbyte();
switch (next) {
case DebugItemType.END_SEQUENCE: {
return endOfData();
}
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 = dexFile.getOptionalString(reader.readSmallUleb128() - 1);
String type = dexFile.getOptionalType(reader.readSmallUleb128() - 1);
ImmutableStartLocal startLocal =
new ImmutableStartLocal(codeAddress, register, name, type, null);
if (register >= 0 && register < locals.length) {
locals[register] = startLocal;
}
return startLocal;
}
case DebugItemType.START_LOCAL_EXTENDED: {
int register = reader.readSmallUleb128();
String name = dexFile.getOptionalString(reader.readSmallUleb128() - 1);
String type = dexFile.getOptionalType(reader.readSmallUleb128() - 1);
String signature = dexFile.getOptionalString(reader.readSmallUleb128() - 1);
ImmutableStartLocal startLocal =
new ImmutableStartLocal(codeAddress, register, name, type, signature);
if (register >= 0 && register < locals.length) {
locals[register] = startLocal;
}
return startLocal;
}
case DebugItemType.END_LOCAL: {
int register = reader.readSmallUleb128();
boolean replaceLocalInTable = true;
LocalInfo localInfo;
if (register >= 0 && register < locals.length) {
localInfo = locals[register];
} else {
localInfo = EMPTY_LOCAL_INFO;
replaceLocalInTable = false;
}
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;
if (register >= 0 && register < locals.length) {
localInfo = locals[register];
} else {
localInfo = EMPTY_LOCAL_INFO;
}
ImmutableRestartLocal restartLocal =
new ImmutableRestartLocal(codeAddress, register, localInfo.getName(),
localInfo.getType(), localInfo.getSignature());
if (register >= 0 && register < locals.length) {
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 = dexFile.getOptionalString(reader.readSmallUleb128() - 1);
return new ImmutableSetSourceFile(codeAddress, sourceFile);
}
default: {
int adjusted = next - 0x0A;
codeAddress += adjusted / 15;
lineNumber += (adjusted % 15) - 4;
return new ImmutableLineNumber(codeAddress, lineNumber);
}
}
}
}
};
}
@Nonnull
@Override
public VariableSizeIterator<String> getParameterNames(@Nullable DexReader reader) {
if (reader == null) {
reader = dexFile.readerAt(debugInfoOffset);
reader.skipUleb128();
}
//TODO: make sure dalvik doesn't allow more parameter names than we have parameters
final int parameterNameCount = reader.readSmallUleb128();
return new VariableSizeIterator<String>(reader, parameterNameCount) {
@Override protected String readNextItem(@Nonnull DexReader reader, int index) {
return dexFile.getOptionalString(reader.readSmallUleb128() - 1);
}
};
}
@Override
public int getSize() {
Iterator<DebugItem> iter = iterator();
while(iter.hasNext()) {
iter.next();
}
return ((VariableSizeLookaheadIterator) iter).getReaderOffset() - debugInfoOffset;
}
}
}