/*
* Copyright 2013, 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.writer;
import org.jf.dexlib2.DebugItemType;
import org.jf.util.ExceptionWithContext;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.io.IOException;
public class DebugWriter<StringKey extends CharSequence, TypeKey extends CharSequence> {
@Nonnull private final StringSection<StringKey, ?> stringSection;
@Nonnull private final TypeSection<StringKey, TypeKey, ?> typeSection;
@Nonnull private final DexDataWriter writer;
private int currentAddress;
private int currentLine;
DebugWriter(@Nonnull StringSection<StringKey, ?> stringSection,
@Nonnull TypeSection<StringKey, TypeKey, ?> typeSection,
@Nonnull DexDataWriter writer) {
this.stringSection = stringSection;
this.typeSection = typeSection;
this.writer = writer;
}
void reset(int startLine) {
this.currentAddress = 0;
this.currentLine = startLine;
}
public void writeStartLocal(int codeAddress, int register,
@Nullable StringKey name,
@Nullable TypeKey type,
@Nullable StringKey signature) throws IOException {
int nameIndex = stringSection.getNullableItemIndex(name);
int typeIndex = typeSection.getNullableItemIndex(type);
int signatureIndex = stringSection.getNullableItemIndex(signature);
writeAdvancePC(codeAddress);
if (signatureIndex == DexWriter.NO_INDEX) {
writer.write(DebugItemType.START_LOCAL);
writer.writeUleb128(register);
writer.writeUleb128(nameIndex + 1);
writer.writeUleb128(typeIndex + 1);
} else {
writer.write(DebugItemType.START_LOCAL_EXTENDED);
writer.writeUleb128(register);
writer.writeUleb128(nameIndex + 1);
writer.writeUleb128(typeIndex + 1);
writer.writeUleb128(signatureIndex + 1);
}
}
public void writeEndLocal(int codeAddress, int register) throws IOException {
writeAdvancePC(codeAddress);
writer.write(DebugItemType.END_LOCAL);
writer.writeUleb128(register);
}
public void writeRestartLocal(int codeAddress, int register) throws IOException {
writeAdvancePC(codeAddress);
writer.write(DebugItemType.RESTART_LOCAL);
writer.writeUleb128(register);
}
public void writePrologueEnd(int codeAddress) throws IOException {
writeAdvancePC(codeAddress);
writer.write(DebugItemType.PROLOGUE_END);
}
public void writeEpilogueBegin(int codeAddress) throws IOException {
writeAdvancePC(codeAddress);
writer.write(DebugItemType.EPILOGUE_BEGIN);
}
public void writeLineNumber(int codeAddress, int lineNumber) throws IOException {
int lineDelta = lineNumber - currentLine;
int addressDelta = codeAddress - currentAddress;
if (addressDelta < 0) {
throw new ExceptionWithContext("debug info items must have non-decreasing code addresses");
}
if (lineDelta < -4 || lineDelta > 10) {
writeAdvanceLine(lineNumber);
lineDelta = 0;
} // no else is intentional here. we might need to advance the PC as well as the line
if ((lineDelta < 2 && addressDelta > 16) || (lineDelta > 1 && addressDelta > 15)) {
writeAdvancePC(codeAddress);
addressDelta = 0;
}
// we need to emit the special opcode even if both lineDelta and addressDelta are 0, otherwise a positions
// entry isn't generated
writeSpecialOpcode(lineDelta, addressDelta);
}
public void writeSetSourceFile(int codeAddress, @Nullable StringKey sourceFile) throws IOException {
writeAdvancePC(codeAddress);
writer.write(DebugItemType.SET_SOURCE_FILE);
writer.writeUleb128(stringSection.getNullableItemIndex(sourceFile) + 1);
}
private void writeAdvancePC(int address) throws IOException {
int addressDelta = address - currentAddress;
if (addressDelta > 0) {
writer.write(1);
writer.writeUleb128(addressDelta);
currentAddress = address;
} /*else if (addressDelta < 0) {
throw new ExceptionWithContext("debug info items must have non-decreasing code addresses");
}*/
}
private void writeAdvanceLine(int line) throws IOException {
int lineDelta = line - currentLine;
if (lineDelta != 0) {
writer.write(2);
writer.writeSleb128(lineDelta);
currentLine = line;
}
}
private static final int LINE_BASE = -4;
private static final int LINE_RANGE = 15;
private static final int FIRST_SPECIAL = 0x0a;
private void writeSpecialOpcode(int lineDelta, int addressDelta) throws IOException {
writer.write((byte)(FIRST_SPECIAL + (addressDelta * LINE_RANGE) + (lineDelta - LINE_BASE)));
currentLine += lineDelta;
currentAddress += addressDelta;
}
}