1 /* 2 * Copyright 2013, Google Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: 8 * 9 * * Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * * Redistributions in binary form must reproduce the above 12 * copyright notice, this list of conditions and the following disclaimer 13 * in the documentation and/or other materials provided with the 14 * distribution. 15 * * Neither the name of Google Inc. nor the names of its 16 * contributors may be used to endorse or promote products derived from 17 * this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 package org.jf.dexlib2.writer; 33 34 import org.jf.dexlib2.DebugItemType; 35 import org.jf.util.ExceptionWithContext; 36 37 import javax.annotation.Nonnull; 38 import javax.annotation.Nullable; 39 import java.io.IOException; 40 41 public class DebugWriter<StringKey extends CharSequence, TypeKey extends CharSequence> { 42 @Nonnull private final StringSection<StringKey, ?> stringSection; 43 @Nonnull private final TypeSection<StringKey, TypeKey, ?> typeSection; 44 @Nonnull private final DexDataWriter writer; 45 private int currentAddress; 46 private int currentLine; 47 DebugWriter(@onnull StringSection<StringKey, ?> stringSection, @Nonnull TypeSection<StringKey, TypeKey, ?> typeSection, @Nonnull DexDataWriter writer)48 DebugWriter(@Nonnull StringSection<StringKey, ?> stringSection, 49 @Nonnull TypeSection<StringKey, TypeKey, ?> typeSection, 50 @Nonnull DexDataWriter writer) { 51 this.stringSection = stringSection; 52 this.typeSection = typeSection; 53 this.writer = writer; 54 } 55 reset(int startLine)56 void reset(int startLine) { 57 this.currentAddress = 0; 58 this.currentLine = startLine; 59 } 60 writeStartLocal(int codeAddress, int register, @Nullable StringKey name, @Nullable TypeKey type, @Nullable StringKey signature)61 public void writeStartLocal(int codeAddress, int register, 62 @Nullable StringKey name, 63 @Nullable TypeKey type, 64 @Nullable StringKey signature) throws IOException { 65 int nameIndex = stringSection.getNullableItemIndex(name); 66 int typeIndex = typeSection.getNullableItemIndex(type); 67 int signatureIndex = stringSection.getNullableItemIndex(signature); 68 69 writeAdvancePC(codeAddress); 70 if (signatureIndex == DexWriter.NO_INDEX) { 71 writer.write(DebugItemType.START_LOCAL); 72 writer.writeUleb128(register); 73 writer.writeUleb128(nameIndex + 1); 74 writer.writeUleb128(typeIndex + 1); 75 } else { 76 writer.write(DebugItemType.START_LOCAL_EXTENDED); 77 writer.writeUleb128(register); 78 writer.writeUleb128(nameIndex + 1); 79 writer.writeUleb128(typeIndex + 1); 80 writer.writeUleb128(signatureIndex + 1); 81 } 82 } 83 writeEndLocal(int codeAddress, int register)84 public void writeEndLocal(int codeAddress, int register) throws IOException { 85 writeAdvancePC(codeAddress); 86 writer.write(DebugItemType.END_LOCAL); 87 writer.writeUleb128(register); 88 } 89 writeRestartLocal(int codeAddress, int register)90 public void writeRestartLocal(int codeAddress, int register) throws IOException { 91 writeAdvancePC(codeAddress); 92 writer.write(DebugItemType.RESTART_LOCAL); 93 writer.writeUleb128(register); 94 } 95 writePrologueEnd(int codeAddress)96 public void writePrologueEnd(int codeAddress) throws IOException { 97 writeAdvancePC(codeAddress); 98 writer.write(DebugItemType.PROLOGUE_END); 99 } 100 writeEpilogueBegin(int codeAddress)101 public void writeEpilogueBegin(int codeAddress) throws IOException { 102 writeAdvancePC(codeAddress); 103 writer.write(DebugItemType.EPILOGUE_BEGIN); 104 } 105 writeLineNumber(int codeAddress, int lineNumber)106 public void writeLineNumber(int codeAddress, int lineNumber) throws IOException { 107 int lineDelta = lineNumber - currentLine; 108 int addressDelta = codeAddress - currentAddress; 109 110 if (addressDelta < 0) { 111 throw new ExceptionWithContext("debug info items must have non-decreasing code addresses"); 112 } 113 if (lineDelta < -4 || lineDelta > 10) { 114 writeAdvanceLine(lineNumber); 115 lineDelta = 0; 116 } // no else is intentional here. we might need to advance the PC as well as the line 117 if ((lineDelta < 2 && addressDelta > 16) || (lineDelta > 1 && addressDelta > 15)) { 118 writeAdvancePC(codeAddress); 119 addressDelta = 0; 120 } 121 122 // we need to emit the special opcode even if both lineDelta and addressDelta are 0, otherwise a positions 123 // entry isn't generated 124 writeSpecialOpcode(lineDelta, addressDelta); 125 } 126 writeSetSourceFile(int codeAddress, @Nullable StringKey sourceFile)127 public void writeSetSourceFile(int codeAddress, @Nullable StringKey sourceFile) throws IOException { 128 writeAdvancePC(codeAddress); 129 writer.write(DebugItemType.SET_SOURCE_FILE); 130 writer.writeUleb128(stringSection.getNullableItemIndex(sourceFile) + 1); 131 } 132 writeAdvancePC(int address)133 private void writeAdvancePC(int address) throws IOException { 134 int addressDelta = address - currentAddress; 135 136 if (addressDelta > 0) { 137 writer.write(1); 138 writer.writeUleb128(addressDelta); 139 currentAddress = address; 140 } /*else if (addressDelta < 0) { 141 throw new ExceptionWithContext("debug info items must have non-decreasing code addresses"); 142 }*/ 143 } 144 writeAdvanceLine(int line)145 private void writeAdvanceLine(int line) throws IOException { 146 int lineDelta = line - currentLine; 147 if (lineDelta != 0) { 148 writer.write(2); 149 writer.writeSleb128(lineDelta); 150 currentLine = line; 151 } 152 } 153 154 private static final int LINE_BASE = -4; 155 private static final int LINE_RANGE = 15; 156 private static final int FIRST_SPECIAL = 0x0a; 157 writeSpecialOpcode(int lineDelta, int addressDelta)158 private void writeSpecialOpcode(int lineDelta, int addressDelta) throws IOException { 159 writer.write((byte)(FIRST_SPECIAL + (addressDelta * LINE_RANGE) + (lineDelta - LINE_BASE))); 160 currentLine += lineDelta; 161 currentAddress += addressDelta; 162 } 163 } 164