C++ DWARFDataExtractor::setAddressSize方法代码示例

bool DWARFDebugLine::LineTable::parse(DWARFDataExtractor &DebugLineData,
                                      uint32_t *OffsetPtr, const DWARFUnit *U,
                                      raw_ostream *OS) {
  const uint32_t DebugLineOffset = *OffsetPtr;

  clear();

  if (!Prologue.parse(DebugLineData, OffsetPtr, U)) {
    // Restore our offset and return false to indicate failure!
    *OffsetPtr = DebugLineOffset;
    return false;
  }

  if (OS)
    Prologue.dump(*OS);

  const uint32_t EndOffset =
      DebugLineOffset + Prologue.TotalLength + Prologue.sizeofTotalLength();

  // See if we should tell the data extractor the address size.
  if (DebugLineData.getAddressSize() == 0)
    DebugLineData.setAddressSize(Prologue.getAddressSize());
  else
    assert(Prologue.getAddressSize() == 0 ||
           Prologue.getAddressSize() == DebugLineData.getAddressSize());

  ParsingState State(this);

  while (*OffsetPtr < EndOffset) {
    if (OS)
      *OS << format("0x%08.08" PRIx32 ": ", *OffsetPtr);

    uint8_t Opcode = DebugLineData.getU8(OffsetPtr);

    if (OS)
      *OS << format("%02.02" PRIx8 " ", Opcode);

    if (Opcode == 0) {
      // Extended Opcodes always start with a zero opcode followed by
      // a uleb128 length so you can skip ones you don't know about
      uint64_t Len = DebugLineData.getULEB128(OffsetPtr);
      uint32_t ExtOffset = *OffsetPtr;

      // Tolerate zero-length; assume length is correct and soldier on.
      if (Len == 0) {
        if (OS)
          *OS << "Badly formed extended line op (length 0)\n";
        continue;
      }

      uint8_t SubOpcode = DebugLineData.getU8(OffsetPtr);
      if (OS)
        *OS << LNExtendedString(SubOpcode);
      switch (SubOpcode) {
      case DW_LNE_end_sequence:
        // Set the end_sequence register of the state machine to true and
        // append a row to the matrix using the current values of the
        // state-machine registers. Then reset the registers to the initial
        // values specified above. Every statement program sequence must end
        // with a DW_LNE_end_sequence instruction which creates a row whose
        // address is that of the byte after the last target machine instruction
        // of the sequence.
        State.Row.EndSequence = true;
        State.appendRowToMatrix(*OffsetPtr);
        if (OS) {
          *OS << "\n";
          OS->indent(12);
          State.Row.dump(*OS);
        }
        State.resetRowAndSequence();
        break;

      case DW_LNE_set_address:
        // Takes a single relocatable address as an operand. The size of the
        // operand is the size appropriate to hold an address on the target
        // machine. Set the address register to the value given by the
        // relocatable address. All of the other statement program opcodes
        // that affect the address register add a delta to it. This instruction
        // stores a relocatable value into it instead.
        //
        // Make sure the extractor knows the address size.  If not, infer it
        // from the size of the operand.
        if (DebugLineData.getAddressSize() == 0)
          DebugLineData.setAddressSize(Len - 1);
        else
          assert(DebugLineData.getAddressSize() == Len - 1);
        State.Row.Address = DebugLineData.getRelocatedAddress(OffsetPtr);
        if (OS)
          *OS << format(" (0x%16.16" PRIx64 ")", State.Row.Address);
        break;

      case DW_LNE_define_file:
        // Takes 4 arguments. The first is a null terminated string containing
        // a source file name. The second is an unsigned LEB128 number
        // representing the directory index of the directory in which the file
        // was found. The third is an unsigned LEB128 number representing the
        // time of last modification of the file. The fourth is an unsigned
        // LEB128 number representing the length in bytes of the file. The time
        // and length fields may contain LEB128(0) if the information is not
        // available.
//.........这里部分代码省略.........