ftl/FTLDWARFDebugLineInfo.cpp

   1 /*
   2  * Copyright (C) 2014 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  14  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  15  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  17  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  18  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  19  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  20  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  21  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  22  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  23  * THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "FTLDWARFDebugLineInfo.h"
  28
  29 #if ENABLE(FTL_JIT)
  30
  31 #include <wtf/DataLog.h>
  32
  33 namespace JSC { namespace FTL {
  34
  35 DebugLineInterpreter::DebugLineInterpreter(const char* program)
  36     : m_program(program)
  37     , m_logResults(false)
  38 {
  39     resetInterpreterState();
  40 }
  41
  42 template <typename T> inline T read(const char*& program)
  43 {
  44     T result = *reinterpret_cast<const T*>(program);
  45     program += sizeof(T);
  46     return result;
  47 }
  48
  49 uint32_t DebugLineInterpreter::parseULEB128(const char*& offset)
  50 {
  51     uint32_t result = 0;
  52     uint8_t byte;
  53     unsigned shiftAmount = 0;
  54     do {
  55         byte = read<uint8_t>(offset);
  56         result |= (byte & ~0x80) << shiftAmount;
  57         shiftAmount += 7;
  58     } while (byte & 0x80);
  59     return result;
  60 }
  61
  62 int32_t DebugLineInterpreter::parseSLEB128(const char*& offset)
  63 {
  64     int32_t result = 0;
  65     uint8_t byte;
  66     unsigned shiftAmount = 0;
  67     do {
  68         byte = read<uint8_t>(offset);
  69         result |= (byte & ~0x80) << shiftAmount;
  70         shiftAmount += 7;
  71     } while (byte & 0x80);
  72
  73     // If the sign bit (in this case, the second MSB) on the last byte is set we need to zero extend.
  74     if (byte & 0x40)
  75         result |= -(1 << shiftAmount);
  76     return result;
  77 }
  78
  79 void DebugLineInterpreter::run()
  80 {
  81     parsePrologue();
  82     interpretStatementProgram();
  83     if (m_logResults)
  84         printLineInfo();
  85 }
  86
  87 void DebugLineInterpreter::parsePrologue()
  88 {
  89     const char* currentProgramOffset = m_program;
  90     m_prologue.totalLength = read<uint32_t>(currentProgramOffset);
  91     if (m_prologue.totalLength == 0xffffffff) {
  92         // This is 64-bit DWARF format.
  93         m_prologue.format = SixtyFourBit;
  94         m_prologue.totalLength = read<uint64_t>(currentProgramOffset);
  95     } else
  96         m_prologue.format = ThirtyTwoBit;
  97     m_prologue.version = read<uint16_t>(currentProgramOffset);
  98
  99     if (m_prologue.format == ThirtyTwoBit)
 100         m_prologue.prologueLength = read<uint32_t>(currentProgramOffset);
 101     else
 102         m_prologue.prologueLength = read<uint64_t>(currentProgramOffset);
 103     const char* afterLengthOffset = currentProgramOffset;
 104
 105     m_prologue.minimumInstructionLength = read<uint8_t>(currentProgramOffset);
 106     m_prologue.defaultIsStatement = read<uint8_t>(currentProgramOffset);
 107     m_prologue.lineBase = read<int8_t>(currentProgramOffset);
 108     m_prologue.lineRange = read<uint8_t>(currentProgramOffset);
 109     m_prologue.opcodeBase = read<uint8_t>(currentProgramOffset);
 110     for (unsigned i = 1; i < m_prologue.opcodeBase; ++i)
 111         m_prologue.standardOpcodeLengths.append(read<uint8_t>(currentProgramOffset));
 112     parseIncludeDirectories(currentProgramOffset);
 113     parseFileEntries(currentProgramOffset);
 114
 115     m_program = afterLengthOffset + m_prologue.prologueLength;
 116
 117     if (!m_logResults)
 118         return;
 119
 120     dataLog("\nPrologue:\n");
 121     dataLog("totalLength = ", m_prologue.totalLength, "\n");
 122     dataLog("version = ", m_prologue.version, "\n");
 123     dataLog("prologueLength = ", m_prologue.prologueLength, "\n");
 124     dataLog("minimumInstructionLength = ", m_prologue.minimumInstructionLength, "\n");
 125     dataLog("defaultIsStatement = ", m_prologue.defaultIsStatement, "\n");
 126     dataLog("lineBase = ", m_prologue.lineBase, "\n");
 127     dataLog("lineRange = ", m_prologue.lineRange, "\n");
 128     dataLog("opcodeBase = ", m_prologue.opcodeBase, "\n");
 129
 130     dataLog("\nStandard Opcode Lengths:\n");
 131     for (unsigned i = 1; i < m_prologue.opcodeBase; ++i)
 132         dataLog("standardOpcodeLengths[", i - 1, "] = ", m_prologue.standardOpcodeLengths[i - 1], "\n");
 133
 134     dataLog("\nInclude Directories:\n");
 135     for (unsigned i = 0; i < m_prologue.includeDirectories.size(); ++i)
 136         dataLog("includeDirectories[", i, "] = ", m_prologue.includeDirectories[i], "\n");
 137
 138     dataLog("\nFiles:\n");
 139     for (unsigned i = 0; i < m_prologue.fileEntries.size(); ++i) {
 140         FileEntry& entry = m_prologue.fileEntries[i];
 141         dataLog("fileEntries[", i, "] = {name: \"", entry.name, "\", dir_index: ", entry.directoryIndex, ", last_modified: ", entry.lastModified, ", size: ", entry.size, "}\n");
 142     }
 143 }
 144
 145 void DebugLineInterpreter::parseIncludeDirectories(const char*& offset)
 146 {
 147     size_t length = 0;
 148     while ((length = strlen(offset))) {
 149         m_prologue.includeDirectories.append(offset);
 150         offset += length + 1;
 151     }
 152
 153     // Extra increment to get past the last null byte.
 154     offset += 1;
 155 }
 156
 157 void DebugLineInterpreter::parseFileEntries(const char*& offset)
 158 {
 159     while (true) {
 160         DebugLineInterpreter::FileEntry nextEntry;
 161         if (!parseFileEntry(offset, nextEntry))
 162             break;
 163         m_prologue.fileEntries.append(nextEntry);
 164     }
 165 }
 166
 167 bool DebugLineInterpreter::parseFileEntry(const char*& offset, FileEntry& entry)
 168 {
 169     size_t length = strlen(offset);
 170     if (!length) {
 171         offset += 1;
 172         return false;
 173     }
 174     entry.name = offset;
 175     offset += length + 1;
 176     entry.directoryIndex = parseULEB128(offset);
 177     entry.lastModified = parseULEB128(offset);
 178     entry.size = parseULEB128(offset);
 179
 180     return true;
 181 }
 182
 183 void DebugLineInterpreter::interpretStatementProgram()
 184 {
 185     const char* currentProgramOffset = m_program;
 186     bool keepGoing = true;
 187     do {
 188         keepGoing = interpretOpcode(currentProgramOffset);
 189     } while (keepGoing);
 190 }
 191
 192 bool DebugLineInterpreter::interpretOpcode(const char*& offset)
 193 {
 194     uint8_t nextOpcode = read<uint8_t>(offset);
 195     switch (nextOpcode) {
 196     case ExtendedOpcodes: {
 197         uint32_t length = parseULEB128(offset);
 198         if (!length)
 199             return false;
 200         uint8_t extendedOpcode = read<uint8_t>(offset);
 201         switch (extendedOpcode) {
 202         case DW_LNE_end_sequence: {
 203             m_currentState.endSequence = true;
 204             m_lineInfoMatrix.append(m_currentState);
 205             resetInterpreterState();
 206             break;
 207         }
 208         case DW_LNE_set_address: {
 209             m_currentState.address = read<size_t>(offset);
 210             break;
 211         }
 212         case DW_LNE_define_file: {
 213             fprintf(stderr, "Unimplemented extended opcode DW_LNE_define_file.\n");
 214             RELEASE_ASSERT_NOT_REACHED();
 215             break;
 216         }
 217         default: {
 218             fprintf(stderr, "Unknown extended opcode.\n");
 219             RELEASE_ASSERT_NOT_REACHED();
 220             break;
 221         }
 222         }
 223         break;
 224     }
 225         /* Standard opcodes */
 226     case DW_LNS_copy: {
 227         m_lineInfoMatrix.append(m_currentState);
 228         m_currentState.isBasicBlock = false;
 229         m_currentState.prologueEnd = false;
 230         m_currentState.epilogueBegin = false;
 231         break;
 232     }
 233     case DW_LNS_advance_pc: {
 234         uint32_t advance = parseULEB128(offset);
 235         m_currentState.address += advance * m_prologue.minimumInstructionLength;
 236         break;
 237     }
 238     case DW_LNS_advance_line: {
 239         int32_t advance = parseSLEB128(offset);
 240         m_currentState.line += advance;
 241         break;
 242     }
 243     case DW_LNS_set_file: {
 244         uint32_t fileIndex = parseULEB128(offset);
 245         m_currentState.file = fileIndex;
 246         break;
 247     }
 248     case DW_LNS_set_column: {
 249         m_currentState.column = parseULEB128(offset);
 250         break;
 251     }
 252     case DW_LNS_negate_stmt: {
 253         m_currentState.isStatement = !m_currentState.isStatement;
 254         break;
 255     }
 256     case DW_LNS_set_basic_block: {
 257         m_currentState.isBasicBlock = true;
 258         break;
 259     }
 260     case DW_LNS_const_add_pc: {
 261         uint8_t adjustedOpcode = nextOpcode - m_prologue.opcodeBase;
 262         uint32_t addressIncrement = (adjustedOpcode / m_prologue.lineRange) * m_prologue.minimumInstructionLength;
 263         m_currentState.address += addressIncrement;
 264         break;
 265     }
 266     case DW_LNS_fixed_advance_pc: {
 267         uint16_t advance = read<uint16_t>(offset);
 268         m_currentState.address += advance;
 269         break;
 270     }
 271     case DW_LNS_set_prologue_end: {
 272         m_currentState.prologueEnd = true;
 273         break;
 274     }
 275     case DW_LNS_set_epilogue_begin: {
 276         m_currentState.epilogueBegin = true;
 277         break;
 278     }
 279     case DW_LNS_set_isa: {
 280         m_currentState.isa = parseULEB128(offset);
 281         break;
 282     }
 283         /* Special opcodes */
 284     default: {
 285         uint8_t adjustedOpcode = nextOpcode - m_prologue.opcodeBase;
 286         uint32_t addressIncrement = (adjustedOpcode / m_prologue.lineRange) * m_prologue.minimumInstructionLength;
 287         int32_t lineIncrement = m_prologue.lineBase + (adjustedOpcode % m_prologue.lineRange);
 288         m_currentState.address += addressIncrement;
 289         m_currentState.line += lineIncrement;
 290         m_lineInfoMatrix.append(m_currentState);
 291         m_currentState.isBasicBlock = false;
 292         m_currentState.prologueEnd = false;
 293         m_currentState.epilogueBegin = false;
 294         break;
 295     }
 296     }
 297     return true;
 298 }
 299
 300 void DebugLineInterpreter::printLineInfo()
 301 {
 302     dataLog("\nLine Info Matrix:\n");
 303     for (unsigned i = 0; i < m_lineInfoMatrix.size(); ++i)
 304         printLineInfo(m_lineInfoMatrix[i]);
 305     dataLog("\n");
 306 }
 307
 308 void DebugLineInterpreter::printLineInfo(LineInfo& info)
 309 {
 310     dataLogF("address: %p", reinterpret_cast<void*>(info.address));
 311     dataLog("  file: ", info.file, "  line: ", info.line, "  column: ", info.column, "  isa: ", info.isa, "  ");
 312     dataLog("  statement?: ", info.isStatement);
 313     dataLog("  basic block?: ", info.isBasicBlock);
 314     dataLog("  end sequence?: ", info.endSequence);
 315     dataLog("  prologue end?: ", info.prologueEnd);
 316     dataLog("  epilogue begin?: ", info.epilogueBegin);
 317     dataLog("\n");
 318 }
 319
 320 void DebugLineInterpreter::resetInterpreterState()
 321 {
 322     m_currentState.address = 0;
 323     m_currentState.file = 1;
 324     m_currentState.line = 1;
 325     m_currentState.column = 0;
 326     m_currentState.isa = 0;
 327     m_currentState.isStatement = false;
 328     m_currentState.isBasicBlock = false;
 329     m_currentState.endSequence = false;
 330     m_currentState.prologueEnd = false;
 331     m_currentState.epilogueBegin = false;
 332 }
 333
 334 } } // namespace JSC::FTL
 335
 336 #endif // ENABLE(FTL_JIT)
 337