C++ DataExtractor::GetDataStart方法代码示例

RegisterContextCorePOSIX_powerpc::RegisterContextCorePOSIX_powerpc(Thread &thread,
                                                                 RegisterInfoInterface *register_info,
                                                                 const DataExtractor &gpregset,
                                                                 const DataExtractor &fpregset)
    : RegisterContextPOSIX_powerpc(thread, 0, register_info)
{
    m_gpr_buffer.reset(new DataBufferHeap(gpregset.GetDataStart(), gpregset.GetByteSize()));
    m_gpr.SetData(m_gpr_buffer);
    m_gpr.SetByteOrder(gpregset.GetByteOrder());
    m_fpr_buffer.reset(new DataBufferHeap(fpregset.GetDataStart(), fpregset.GetByteSize()));
    m_fpr.SetData(m_fpr_buffer);
    m_fpr.SetByteOrder(fpregset.GetByteOrder());
}

ValueObjectConstResult::ValueObjectConstResult
(
    ExecutionContextScope *exe_scope,
    clang::ASTContext *clang_ast,
    void *clang_type,
    const ConstString &name,
    const DataExtractor &data,
    lldb::addr_t address
) :
    ValueObject (exe_scope),
    m_clang_ast (clang_ast),
    m_type_name (),
    m_byte_size (0),
    m_impl(this, address)
{
    m_data = data;
    
    if (!m_data.GetSharedDataBuffer())
    {
        DataBufferSP shared_data_buffer(new DataBufferHeap(data.GetDataStart(), data.GetByteSize()));
        m_data.SetData(shared_data_buffer);
    }
    
    m_value.GetScalar() = (uintptr_t)m_data.GetDataStart();
    m_value.SetValueType(Value::eValueTypeHostAddress);
    m_value.SetContext(Value::eContextTypeClangType, clang_type);
    m_name = name;
    SetIsConstant ();
    SetValueIsValid(true);
    SetAddressTypeOfChildren(eAddressTypeLoad);
}

RegisterContextCorePOSIX_mips64::RegisterContextCorePOSIX_mips64(Thread &thread,
                                                                 RegisterInfoInterface *register_info,
                                                                 const DataExtractor &gpregset,
                                                                 const DataExtractor &fpregset,
                                                                 const DataExtractor &capregset)
    : RegisterContextPOSIX_mips64(thread, 0, register_info)
{
    m_gpr_buffer.reset(new DataBufferHeap(gpregset.GetDataStart(), gpregset.GetByteSize()));
    m_gpr.SetData(m_gpr_buffer);
    m_gpr.SetByteOrder(gpregset.GetByteOrder());

    m_cr_buffer.reset(new DataBufferHeap(capregset.GetDataStart(), capregset.GetByteSize()));
    m_cr.SetData(m_cr_buffer);
    m_cr.SetByteOrder(capregset.GetByteOrder());

    m_in_bd = lldb_private::eLazyBoolCalculate;
}

RegisterContextCorePOSIX_arm64::RegisterContextCorePOSIX_arm64(
    Thread &thread, RegisterInfoInterface *register_info,
    const DataExtractor &gpregset, llvm::ArrayRef<CoreNote> notes)
    : RegisterContextPOSIX_arm64(thread, 0, register_info) {
  m_gpr_buffer.reset(
      new DataBufferHeap(gpregset.GetDataStart(), gpregset.GetByteSize()));
  m_gpr.SetData(m_gpr_buffer);
  m_gpr.SetByteOrder(gpregset.GetByteOrder());
}

bool
RegisterContextMacOSXFrameBackchain::ReadRegisterBytes (uint32_t reg, DataExtractor &data)
{
    Scalar reg_value;

    if (ReadRegisterValue (reg, reg_value))
    {
        if (reg_value.GetData(data))
        {
            // "reg_value" is local and now "data" points to the data within
            // "reg_value", so we must make a copy that will live within "data"
            DataBufferSP data_sp (new DataBufferHeap (data.GetDataStart(), data.GetByteSize()));
            data.SetData (data_sp, 0, data.GetByteSize());
            return true;
        }
    }
    return false;
}

    virtual bool
    DoesBranch ()
    {
        if (m_does_branch == eLazyBoolCalculate)
        {
            GetDisassemblerLLVMC().Lock(this, NULL);
            DataExtractor data;
            if (m_opcode.GetData(data))
            {
                bool is_alternate_isa;
                lldb::addr_t pc = m_address.GetFileAddress();

                DisassemblerLLVMC::LLVMCDisassembler *mc_disasm_ptr = GetDisasmToUse (is_alternate_isa);
                const uint8_t *opcode_data = data.GetDataStart();
                const size_t opcode_data_len = data.GetByteSize();
                llvm::MCInst inst;
                const size_t inst_size = mc_disasm_ptr->GetMCInst (opcode_data,
                                                                   opcode_data_len,
                                                                   pc,
                                                                   inst);
                // Be conservative, if we didn't understand the instruction, say it might branch...
                if (inst_size == 0)
                    m_does_branch = eLazyBoolYes;
                else
                {
                    const bool can_branch = mc_disasm_ptr->CanBranch(inst);
                    if (can_branch)
                        m_does_branch = eLazyBoolYes;
                    else
                        m_does_branch = eLazyBoolNo;
                }
            }
            GetDisassemblerLLVMC().Unlock();
        }
        return m_does_branch == eLazyBoolYes;
    }

bool
EmulateInstructionMIPS::EvaluateInstruction (uint32_t evaluate_options)
{
    bool success = false;
    llvm::MCInst mc_insn;
    uint64_t insn_size;
    DataExtractor data;

    /* Keep the complexity of the decode logic with the llvm::MCDisassembler class. */
    if (m_opcode.GetData (data))
    {
        llvm::MCDisassembler::DecodeStatus decode_status;
        llvm::ArrayRef<uint8_t> raw_insn (data.GetDataStart(), data.GetByteSize());
        decode_status = m_disasm->getInstruction (mc_insn, insn_size, raw_insn, m_addr, llvm::nulls(), llvm::nulls());
        if (decode_status != llvm::MCDisassembler::Success)
            return false;
    }

    /*
     * mc_insn.getOpcode() returns decoded opcode. However to make use
     * of llvm::Mips::<insn> we would need "MipsGenInstrInfo.inc".
    */
    const char *op_name = m_insn_info->getName (mc_insn.getOpcode ());

    if (op_name == NULL)
        return false;

    /*
     * Decoding has been done already. Just get the call-back function
     * and emulate the instruction.
    */
    MipsOpcode *opcode_data = GetOpcodeForInstruction (op_name);

    if (opcode_data == NULL)
        return false;

    uint64_t old_pc = 0, new_pc = 0;
    const bool auto_advance_pc = evaluate_options & eEmulateInstructionOptionAutoAdvancePC;

    if (auto_advance_pc)
    {
        old_pc = ReadRegisterUnsigned (eRegisterKindDWARF, gcc_dwarf_pc_mips64, 0, &success);
        if (!success)
            return false;
    }

    /* emulate instruction */
    success = (this->*opcode_data->callback) (mc_insn);
    if (!success)
        return false;

    if (auto_advance_pc)
    {
        new_pc = ReadRegisterUnsigned (eRegisterKindDWARF, gcc_dwarf_pc_mips64, 0, &success);
        if (!success)
            return false;

        /* If we haven't changed the PC, change it here */
        if (old_pc == new_pc)
        {
            new_pc += 4;
            Context context;
            if (!WriteRegisterUnsigned (context, eRegisterKindDWARF, gcc_dwarf_pc_mips64, new_pc))
                return false;
        }
    }

    return true;
}

static bool
DumpUTFBufferToStream (ConversionResult (*ConvertFunction) (const SourceDataType**,
                       const SourceDataType*,
                       UTF8**,
                       UTF8*,
                       ConversionFlags),
                       const DataExtractor& data,
                       Stream& stream,
                       char prefix_token,
                       char quote,
                       uint32_t sourceSize,
                       bool escapeNonPrintables)
{
    if (prefix_token != 0)
        stream.Printf("%c",prefix_token);
    if (quote != 0)
        stream.Printf("%c",quote);
    if (data.GetByteSize() && data.GetDataStart() && data.GetDataEnd())
    {
        const int bufferSPSize = data.GetByteSize();
        if (sourceSize == 0)
        {
            const int origin_encoding = 8*sizeof(SourceDataType);
            sourceSize = bufferSPSize/(origin_encoding / 4);
        }

        const SourceDataType *data_ptr = (const SourceDataType*)data.GetDataStart();
        const SourceDataType *data_end_ptr = data_ptr + sourceSize;

        while (data_ptr < data_end_ptr)
        {
            if (!*data_ptr)
            {
                data_end_ptr = data_ptr;
                break;
            }
            data_ptr++;
        }

        data_ptr = (const SourceDataType*)data.GetDataStart();

        lldb::DataBufferSP utf8_data_buffer_sp;
        UTF8* utf8_data_ptr = nullptr;
        UTF8* utf8_data_end_ptr = nullptr;

        if (ConvertFunction)
        {
            utf8_data_buffer_sp.reset(new DataBufferHeap(4*bufferSPSize,0));
            utf8_data_ptr = (UTF8*)utf8_data_buffer_sp->GetBytes();
            utf8_data_end_ptr = utf8_data_ptr + utf8_data_buffer_sp->GetByteSize();
            ConvertFunction ( &data_ptr, data_end_ptr, &utf8_data_ptr, utf8_data_end_ptr, lenientConversion );
            utf8_data_ptr = (UTF8*)utf8_data_buffer_sp->GetBytes(); // needed because the ConvertFunction will change the value of the data_ptr
        }
        else
        {
            // just copy the pointers - the cast is necessary to make the compiler happy
            // but this should only happen if we are reading UTF8 data
            utf8_data_ptr = (UTF8*)data_ptr;
            utf8_data_end_ptr = (UTF8*)data_end_ptr;
        }

        // since we tend to accept partial data (and even partially malformed data)
        // we might end up with no NULL terminator before the end_ptr
        // hence we need to take a slower route and ensure we stay within boundaries
        for (; utf8_data_ptr < utf8_data_end_ptr;)
        {
            if (!*utf8_data_ptr)
                break;

            if (escapeNonPrintables)
            {
                uint8_t* next_data = nullptr;
                auto printable = GetPrintable(StringElementType::UTF8, utf8_data_ptr, utf8_data_end_ptr, next_data);
                auto printable_bytes = printable.GetBytes();
                auto printable_size = printable.GetSize();
                if (!printable_bytes || !next_data)
                {
                    // GetPrintable() failed on us - print one byte in a desperate resync attempt
                    printable_bytes = utf8_data_ptr;
                    printable_size = 1;
                    next_data = utf8_data_ptr+1;
                }
                for (unsigned c = 0; c < printable_size; c++)
                    stream.Printf("%c", *(printable_bytes+c));
                utf8_data_ptr = (uint8_t*)next_data;
            }
            else
            {
                stream.Printf("%c",*utf8_data_ptr);
                utf8_data_ptr++;
            }
        }
    }
    if (quote != 0)
        stream.Printf("%c",quote);
    return true;
}

static bool
DumpUTFBufferToStream (ConversionResult (*ConvertFunction) (const SourceDataType**,
                                                            const SourceDataType*,
                                                            UTF8**,
                                                            UTF8*,
                                                            ConversionFlags),
                       DataExtractor& data,
                       Stream& stream,
                       char prefix_token = '@',
                       char quote = '"',
                       uint32_t sourceSize = 0)
{
    if (prefix_token != 0)
        stream.Printf("%c",prefix_token);
    if (quote != 0)
        stream.Printf("%c",quote);
    if (data.GetByteSize() && data.GetDataStart() && data.GetDataEnd())
    {
        const int bufferSPSize = data.GetByteSize();
        if (sourceSize == 0)
        {
            const int origin_encoding = 8*sizeof(SourceDataType);
            sourceSize = bufferSPSize/(origin_encoding / 4);
        }
        
        SourceDataType *data_ptr = (SourceDataType*)data.GetDataStart();
        SourceDataType *data_end_ptr = data_ptr + sourceSize;
        
        while (data_ptr < data_end_ptr)
        {
            if (!*data_ptr)
            {
                data_end_ptr = data_ptr;
                break;
            }
            data_ptr++;
        }
        
        data_ptr = (SourceDataType*)data.GetDataStart();
        
        lldb::DataBufferSP utf8_data_buffer_sp;
        UTF8* utf8_data_ptr = nullptr;
        UTF8* utf8_data_end_ptr = nullptr;
        
        if (ConvertFunction)
        {
            utf8_data_buffer_sp.reset(new DataBufferHeap(4*bufferSPSize,0));
            utf8_data_ptr = (UTF8*)utf8_data_buffer_sp->GetBytes();
            utf8_data_end_ptr = utf8_data_ptr + utf8_data_buffer_sp->GetByteSize();
            ConvertFunction ( (const SourceDataType**)&data_ptr, data_end_ptr, &utf8_data_ptr, utf8_data_end_ptr, lenientConversion );
            utf8_data_ptr = (UTF8*)utf8_data_buffer_sp->GetBytes(); // needed because the ConvertFunction will change the value of the data_ptr
        }
        else
        {
            // just copy the pointers - the cast is necessary to make the compiler happy
            // but this should only happen if we are reading UTF8 data
            utf8_data_ptr = (UTF8*)data_ptr;
            utf8_data_end_ptr = (UTF8*)data_end_ptr;
        }
        
        // since we tend to accept partial data (and even partially malformed data)
        // we might end up with no NULL terminator before the end_ptr
        // hence we need to take a slower route and ensure we stay within boundaries
        for (;utf8_data_ptr != utf8_data_end_ptr; utf8_data_ptr++)
        {
            if (!*utf8_data_ptr)
                break;
            stream.Printf("%c",*utf8_data_ptr);
        }
    }
    if (quote != 0)
        stream.Printf("%c",quote);
    return true;
}

    virtual void
    CalculateMnemonicOperandsAndComment (const lldb_private::ExecutionContext *exe_ctx)
    {
        DataExtractor data;
        const AddressClass address_class = GetAddressClass ();

        if (m_opcode.GetData(data))
        {
            char out_string[512];
            
            DisassemblerLLVMC &llvm_disasm = GetDisassemblerLLVMC();

            DisassemblerLLVMC::LLVMCDisassembler *mc_disasm_ptr;
            
            if (address_class == eAddressClassCodeAlternateISA)
                mc_disasm_ptr = llvm_disasm.m_alternate_disasm_ap.get();
            else
                mc_disasm_ptr = llvm_disasm.m_disasm_ap.get();
            
            lldb::addr_t pc = m_address.GetFileAddress();
            m_using_file_addr = true;
            
            const bool data_from_file = GetDisassemblerLLVMC().m_data_from_file;
            bool use_hex_immediates = true;
            Disassembler::HexImmediateStyle hex_style = Disassembler::eHexStyleC;

            if (exe_ctx)
            {
                Target *target = exe_ctx->GetTargetPtr();
                if (target)
                {
                    use_hex_immediates = target->GetUseHexImmediates();
                    hex_style = target->GetHexImmediateStyle();

                    if (!data_from_file)
                    {
                        const lldb::addr_t load_addr = m_address.GetLoadAddress(target);
                        if (load_addr != LLDB_INVALID_ADDRESS)
                        {
                            pc = load_addr;
                            m_using_file_addr = false;
                        }
                    }
                }
            }
            
            llvm_disasm.Lock(this, exe_ctx);
            
            const uint8_t *opcode_data = data.GetDataStart();
            const size_t opcode_data_len = data.GetByteSize();
            llvm::MCInst inst;
            size_t inst_size = mc_disasm_ptr->GetMCInst (opcode_data,
                                                         opcode_data_len,
                                                         pc,
                                                         inst);

            if (inst_size > 0)
            {
                mc_disasm_ptr->SetStyle(use_hex_immediates, hex_style);
                mc_disasm_ptr->PrintMCInst(inst, out_string, sizeof(out_string));
            }

            llvm_disasm.Unlock();
            
            if (inst_size == 0)
            {
                m_comment.assign ("unknown opcode");
                inst_size = m_opcode.GetByteSize();
                StreamString mnemonic_strm;
                lldb::offset_t offset = 0;
                lldb::ByteOrder byte_order = data.GetByteOrder();
                switch (inst_size)
                {
                    case 1:
                        {
                            const uint8_t uval8 = data.GetU8 (&offset);
                            m_opcode.SetOpcode8 (uval8, byte_order);
                            m_opcode_name.assign (".byte");
                            mnemonic_strm.Printf("0x%2.2x", uval8);
                        }
                        break;
                    case 2:
                        {
                            const uint16_t uval16 = data.GetU16(&offset);
                            m_opcode.SetOpcode16(uval16, byte_order);
                            m_opcode_name.assign (".short");
                            mnemonic_strm.Printf("0x%4.4x", uval16);
                        }
                        break;
                    case 4:
                        {
                            const uint32_t uval32 = data.GetU32(&offset);
                            m_opcode.SetOpcode32(uval32, byte_order);
                            m_opcode_name.assign (".long");
                            mnemonic_strm.Printf("0x%8.8x", uval32);
                        }
                        break;
                    case 8:
                        {
                            const uint64_t uval64 = data.GetU64(&offset);
//.........这里部分代码省略.........

 bool
 DoExecute (Args& command, CommandReturnObject &result)
 {
     const size_t argc = command.GetArgumentCount();
     if (argc == 0)
     {
         if (!m_command_byte.GetOptionValue().OptionWasSet())
         {
             result.AppendError ("the --command option must be set to a valid command byte");
             result.SetStatus (eReturnStatusFailed);
         }
         else
         {
             const uint64_t command_byte = m_command_byte.GetOptionValue().GetUInt64Value(0);
             if (command_byte > 0 && command_byte <= UINT8_MAX)
             {
                 ProcessKDP *process = (ProcessKDP *)m_interpreter.GetExecutionContext().GetProcessPtr();
                 if (process)
                 {
                     const StateType state = process->GetState();
                     
                     if (StateIsStoppedState (state, true))
                     {
                         std::vector<uint8_t> payload_bytes;
                         const char *ascii_hex_bytes_cstr = m_packet_data.GetOptionValue().GetCurrentValue();
                         if (ascii_hex_bytes_cstr && ascii_hex_bytes_cstr[0])
                         {
                             StringExtractor extractor(ascii_hex_bytes_cstr);
                             const size_t ascii_hex_bytes_cstr_len = extractor.GetStringRef().size();
                             if (ascii_hex_bytes_cstr_len & 1)
                             {
                                 result.AppendErrorWithFormat ("payload data must contain an even number of ASCII hex characters: '%s'", ascii_hex_bytes_cstr);
                                 result.SetStatus (eReturnStatusFailed);
                                 return false;
                             }
                             payload_bytes.resize(ascii_hex_bytes_cstr_len/2);
                             if (extractor.GetHexBytes(&payload_bytes[0], payload_bytes.size(), '\xdd') != payload_bytes.size())
                             {
                                 result.AppendErrorWithFormat ("payload data must only contain ASCII hex characters (no spaces or hex prefixes): '%s'", ascii_hex_bytes_cstr);
                                 result.SetStatus (eReturnStatusFailed);
                                 return false;
                             }
                         }
                         Error error;
                         DataExtractor reply;
                         process->GetCommunication().SendRawRequest (command_byte,
                                                                     payload_bytes.empty() ? NULL : payload_bytes.data(),
                                                                     payload_bytes.size(),
                                                                     reply,
                                                                     error);
                         
                         if (error.Success())
                         {
                             // Copy the binary bytes into a hex ASCII string for the result
                             StreamString packet;
                             packet.PutBytesAsRawHex8(reply.GetDataStart(),
                                                      reply.GetByteSize(),
                                                      lldb::endian::InlHostByteOrder(),
                                                      lldb::endian::InlHostByteOrder());
                             result.AppendMessage(packet.GetString().c_str());
                             result.SetStatus (eReturnStatusSuccessFinishResult);
                             return true;
                         }
                         else
                         {
                             const char *error_cstr = error.AsCString();
                             if (error_cstr && error_cstr[0])
                                 result.AppendError (error_cstr);
                             else
                                 result.AppendErrorWithFormat ("unknown error 0x%8.8x", error.GetError());
                             result.SetStatus (eReturnStatusFailed);
                             return false;
                         }
                     }
                     else
                     {
                         result.AppendErrorWithFormat ("process must be stopped in order to send KDP packets, state is %s", StateAsCString (state));
                         result.SetStatus (eReturnStatusFailed);
                     }
                 }
                 else
                 {
                     result.AppendError ("invalid process");
                     result.SetStatus (eReturnStatusFailed);
                 }
             }
             else
             {
                 result.AppendErrorWithFormat ("invalid command byte 0x%" PRIx64 ", valid values are 1 - 255", command_byte);
                 result.SetStatus (eReturnStatusFailed);
             }
         }
     }
     else
     {
         result.AppendErrorWithFormat ("'%s' takes no arguments, only options.", m_cmd_name.c_str());
         result.SetStatus (eReturnStatusFailed);
     }
     return false;
 }

//.........这里部分代码省略.........
      const bool scalar_is_load_address = false;
      lldb::addr_t addr_of_valobj =
          valobj_sp->GetAddressOf(scalar_is_load_address, &address_type);
      if (addr_of_valobj != LLDB_INVALID_ADDRESS) {
        Status write_error;
        map.WritePointerToMemory(load_addr, addr_of_valobj, write_error);

        if (!write_error.Success()) {
          err.SetErrorStringWithFormat(
              "couldn't write the address of variable %s to memory: %s",
              m_variable_sp->GetName().AsCString(), write_error.AsCString());
          return;
        }
      } else {
        DataExtractor data;
        Status extract_error;
        valobj_sp->GetData(data, extract_error);
        if (!extract_error.Success()) {
          err.SetErrorStringWithFormat("couldn't get the value of %s: %s",
                                       m_variable_sp->GetName().AsCString(),
                                       extract_error.AsCString());
          return;
        }

        if (m_temporary_allocation != LLDB_INVALID_ADDRESS) {
          err.SetErrorStringWithFormat(
              "trying to create a temporary region for %s but one exists",
              m_variable_sp->GetName().AsCString());
          return;
        }

        if (data.GetByteSize() < m_variable_sp->GetType()->GetByteSize()) {
          if (data.GetByteSize() == 0 &&
              m_variable_sp->LocationExpression().IsValid() == false) {
            err.SetErrorStringWithFormat("the variable '%s' has no location, "
                                         "it may have been optimized out",
                                         m_variable_sp->GetName().AsCString());
          } else {
            err.SetErrorStringWithFormat(
                "size of variable %s (%" PRIu64
                ") is larger than the ValueObject's size (%" PRIu64 ")",
                m_variable_sp->GetName().AsCString(),
                m_variable_sp->GetType()->GetByteSize(), data.GetByteSize());
          }
          return;
        }

        size_t bit_align =
            m_variable_sp->GetType()->GetLayoutCompilerType().GetTypeBitAlign();
        size_t byte_align = (bit_align + 7) / 8;

        if (!byte_align)
          byte_align = 1;

        Status alloc_error;
        const bool zero_memory = false;

        m_temporary_allocation = map.Malloc(
            data.GetByteSize(), byte_align,
            lldb::ePermissionsReadable | lldb::ePermissionsWritable,
            IRMemoryMap::eAllocationPolicyMirror, zero_memory, alloc_error);

        m_temporary_allocation_size = data.GetByteSize();

        m_original_data.reset(
            new DataBufferHeap(data.GetDataStart(), data.GetByteSize()));

        if (!alloc_error.Success()) {
          err.SetErrorStringWithFormat(
              "couldn't allocate a temporary region for %s: %s",
              m_variable_sp->GetName().AsCString(), alloc_error.AsCString());
          return;
        }

        Status write_error;

        map.WriteMemory(m_temporary_allocation, data.GetDataStart(),
                        data.GetByteSize(), write_error);

        if (!write_error.Success()) {
          err.SetErrorStringWithFormat(
              "couldn't write to the temporary region for %s: %s",
              m_variable_sp->GetName().AsCString(), write_error.AsCString());
          return;
        }

        Status pointer_write_error;

        map.WritePointerToMemory(load_addr, m_temporary_allocation,
                                 pointer_write_error);

        if (!pointer_write_error.Success()) {
          err.SetErrorStringWithFormat(
              "couldn't write the address of the temporary region for %s: %s",
              m_variable_sp->GetName().AsCString(),
              pointer_write_error.AsCString());
        }
      }
    }
  }