C++ DataExtractor::PeekData方法代码示例

static bool
GetNetBSDProcessArgs (const ProcessInstanceInfoMatch *match_info_ptr,
                      ProcessInstanceInfo &process_info)
{
    if (!process_info.ProcessIDIsValid())
        return false;

    int pid = process_info.GetProcessID();

    int mib[4] = { CTL_KERN, KERN_PROC_ARGS, pid, KERN_PROC_ARGV };

    char arg_data[8192];
    size_t arg_data_size = sizeof(arg_data);
    if (::sysctl (mib, 4, arg_data, &arg_data_size , NULL, 0) != 0)
        return false;

    DataExtractor data (arg_data, arg_data_size, lldb::endian::InlHostByteOrder(), sizeof(void *));
    lldb::offset_t offset = 0;
    const char *cstr;

    cstr = data.GetCStr (&offset);
    if (!cstr)
        return false;

    process_info.GetExecutableFile().SetFile(cstr, false);

    if (!(match_info_ptr == NULL ||
            NameMatches (process_info.GetExecutableFile().GetFilename().GetCString(),
                         match_info_ptr->GetNameMatchType(),
                         match_info_ptr->GetProcessInfo().GetName())))
        return false;

    Args &proc_args = process_info.GetArguments();
    while (1)
    {
        const uint8_t *p = data.PeekData(offset, 1);
        while ((p != NULL) && (*p == '\0') && offset < arg_data_size)
        {
            ++offset;
            p = data.PeekData(offset, 1);
        }
        if (p == NULL || offset >= arg_data_size)
            break;

        cstr = data.GetCStr(&offset);
        if (!cstr)
            break;

        proc_args.AppendArgument(cstr);
    }

    return true;
}

bool Type::ReadFromMemory(ExecutionContext *exe_ctx, lldb::addr_t addr,
                          AddressType address_type, DataExtractor &data) {
  if (address_type == eAddressTypeFile) {
    // Can't convert a file address to anything valid without more
    // context (which Module it came from)
    return false;
  }

  const uint64_t byte_size = GetByteSize();
  if (data.GetByteSize() < byte_size) {
    lldb::DataBufferSP data_sp(new DataBufferHeap(byte_size, '\0'));
    data.SetData(data_sp);
  }

  uint8_t *dst = const_cast<uint8_t *>(data.PeekData(0, byte_size));
  if (dst != nullptr) {
    if (address_type == eAddressTypeHost) {
      // The address is an address in this process, so just copy it
      if (addr == 0)
        return false;
      memcpy(dst, (uint8_t *)nullptr + addr, byte_size);
      return true;
    } else {
      if (exe_ctx) {
        Process *process = exe_ctx->GetProcessPtr();
        if (process) {
          Error error;
          return exe_ctx->GetProcessPtr()->ReadMemory(addr, dst, byte_size,
                                                      error) == byte_size;
        }
      }
    }
  }
  return false;
}

bool
ObjectContainerBSDArchive::MagicBytesMatch (const DataExtractor &data)
{
    uint32_t offset = 0;
    const char* armag = (const char* )data.PeekData (offset, sizeof(ar_hdr));
    if (armag && ::strncmp(armag, ARMAG, SARMAG) == 0)
    {
        armag += offsetof(struct ar_hdr, ar_fmag) + SARMAG;
        if (strncmp(armag, ARFMAG, 2) == 0)
            return true;
    }

//.........这里部分代码省略.........
                data.SetByteOrder(target->GetArchitecture().GetByteOrder());
                data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
                break;
            }
        }
        // fallback to host settings
        data.SetByteOrder(endian::InlHostByteOrder());
        data.SetAddressByteSize(sizeof(void *));
        break;
    }

    // Bail if we encountered any errors
    if (error.Fail())
        return error;

    if (address == LLDB_INVALID_ADDRESS)
    {
        error.SetErrorStringWithFormat ("invalid %s address", address_type == eAddressTypeHost ? "host" : "load");
        return error;
    }

    // If we got here, we need to read the value from memory
    size_t byte_size = GetValueByteSize (&error, exe_ctx);

    // Bail if we encountered any errors getting the byte size
    if (error.Fail())
        return error;

    // Make sure we have enough room within "data", and if we don't make
    // something large enough that does
    if (!data.ValidOffsetForDataOfSize (data_offset, byte_size))
    {
        DataBufferSP data_sp(new DataBufferHeap (data_offset + byte_size, '\0'));
        data.SetData(data_sp);
    }

    uint8_t* dst = const_cast<uint8_t*>(data.PeekData (data_offset, byte_size));
    if (dst != NULL)
    {
        if (address_type == eAddressTypeHost)
        {
            // The address is an address in this process, so just copy it.
            if (address == 0)
            {
                error.SetErrorStringWithFormat("trying to read from host address of 0.");
                return error;
            }
            memcpy (dst, (uint8_t*)NULL + address, byte_size);
        }
        else if ((address_type == eAddressTypeLoad) || (address_type == eAddressTypeFile))
        {
            if (file_so_addr.IsValid())
            {
                // We have a file address that we were able to translate into a
                // section offset address so we might be able to read this from
                // the object files if we don't have a live process. Lets always
                // try and read from the process if we have one though since we
                // want to read the actual value by setting "prefer_file_cache"
                // to false. 
                const bool prefer_file_cache = false;
                if (exe_ctx->GetTargetRef().ReadMemory(file_so_addr, prefer_file_cache, dst, byte_size, error) != byte_size)
                {
                    error.SetErrorStringWithFormat("read memory from 0x%" PRIx64 " failed", (uint64_t)address);
                }
            }
            else
            {
                // The execution context might have a NULL process, but it
                // might have a valid process in the exe_ctx->target, so use
                // the ExecutionContext::GetProcess accessor to ensure we
                // get the process if there is one.
                Process *process = exe_ctx->GetProcessPtr();

                if (process)
                {
                    const size_t bytes_read = process->ReadMemory(address, dst, byte_size, error);
                    if (bytes_read != byte_size)
                        error.SetErrorStringWithFormat("read memory from 0x%" PRIx64 " failed (%u of %u bytes read)",
                                                       (uint64_t)address, 
                                                       (uint32_t)bytes_read, 
                                                       (uint32_t)byte_size);
                }
                else
                {
                    error.SetErrorStringWithFormat("read memory from 0x%" PRIx64 " failed (invalid process)", (uint64_t)address);
                }
            }
        }
        else
        {
            error.SetErrorStringWithFormat ("unsupported AddressType value (%i)", address_type);
        }
    }
    else
    {
        error.SetErrorStringWithFormat ("out of memory");
    }

    return error;
}

//.........这里部分代码省略.........
            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);
                            m_opcode.SetOpcode64(uval64, byte_order);
                            m_opcode_name.assign (".quad");
                            mnemonic_strm.Printf("0x%16.16" PRIx64, uval64);
                        }
                        break;
                    default:
                        if (inst_size == 0)
                            return;
                        else
                        {
                            const uint8_t *bytes = data.PeekData(offset, inst_size);
                            if (bytes == NULL)
                                return;
                            m_opcode_name.assign (".byte");
                            m_opcode.SetOpcodeBytes(bytes, inst_size);
                            mnemonic_strm.Printf("0x%2.2x", bytes[0]);
                            for (uint32_t i=1; i<inst_size; ++i)
                                mnemonic_strm.Printf(" 0x%2.2x", bytes[i]);
                        }
                        break;
                }
                m_mnemonics.swap(mnemonic_strm.GetString());
                return;
            }
            else
            {
                if (m_does_branch == eLazyBoolCalculate)
                {
                    const bool can_branch = mc_disasm_ptr->CanBranch(inst);
                    if (can_branch)
                        m_does_branch = eLazyBoolYes;
                    else
                        m_does_branch = eLazyBoolNo;

                }
            }
            
            static RegularExpression s_regex("[ \t]*([^ ^\t]+)[ \t]*([^ ^\t].*)?", REG_EXTENDED);
            
            RegularExpression::Match matches(3);
            
            if (s_regex.Execute(out_string, &matches))
            {
                matches.GetMatchAtIndex(out_string, 1, m_opcode_name);
                matches.GetMatchAtIndex(out_string, 2, m_mnemonics);
            }
        }
    }

bool
RegisterContextMach_i386::WriteRegisterBytes (uint32_t reg, DataExtractor &data, uint32_t data_offset)
{
    int set = GetSetForNativeRegNum (reg);

    if (set == -1)
        return false;

    if (ReadRegisterSet(set, false) != KERN_SUCCESS)
        return false;


    const RegisterInfo * reg_info = GetRegisterInfoAtIndex (reg);
    if (reg_info == NULL && data.ValidOffsetForDataOfSize(data_offset, reg_info->byte_size))
        return false;

    uint32_t offset = data_offset;
    switch (reg)
    {
    case gpr_eax:
    case gpr_ebx:
    case gpr_ecx:
    case gpr_edx:
    case gpr_edi:
    case gpr_esi:
    case gpr_ebp:
    case gpr_esp:
    case gpr_ss:
    case gpr_eflags:
    case gpr_eip:
    case gpr_cs:
    case gpr_ds:
    case gpr_es:
    case gpr_fs:
    case gpr_gs:
        (&gpr.eax)[reg - gpr_eax] = data.GetU32 (&offset);
        break;

    case fpu_fcw:
        fpu.fcw = data.GetU16(&offset);
        break;

    case fpu_fsw:
        fpu.fsw = data.GetU16(&offset);
        break;

    case fpu_ftw:
        fpu.ftw = data.GetU8(&offset);
        break;

    case fpu_fop:
        fpu.fop = data.GetU16(&offset);
        break;

    case fpu_ip:
        fpu.ip = data.GetU32(&offset);
        break;

    case fpu_cs:
        fpu.cs = data.GetU16(&offset);
        break;

    case fpu_dp:
        fpu.dp = data.GetU32(&offset);
        break;

    case fpu_ds:
        fpu.ds = data.GetU16(&offset);
        break;

    case fpu_mxcsr:
        fpu.mxcsr = data.GetU32(&offset);
        break;

    case fpu_mxcsrmask:
        fpu.mxcsrmask = data.GetU32(&offset);
        break;

    case fpu_stmm0:
    case fpu_stmm1:
    case fpu_stmm2:
    case fpu_stmm3:
    case fpu_stmm4:
    case fpu_stmm5:
    case fpu_stmm6:
    case fpu_stmm7:
        ::memcpy (fpu.stmm[reg - fpu_stmm0].bytes, data.PeekData(offset, reg_info->byte_size), reg_info->byte_size);
        return false;

    case fpu_xmm0:
    case fpu_xmm1:
    case fpu_xmm2:
    case fpu_xmm3:
    case fpu_xmm4:
    case fpu_xmm5:
    case fpu_xmm6:
    case fpu_xmm7:
        // These values don't fit into scalar types, RegisterContext::ReadRegisterBytes()
        // must be used for these registers
        ::memcpy (fpu.xmm[reg - fpu_xmm0].bytes, data.PeekData(offset, reg_info->byte_size), reg_info->byte_size);
//.........这里部分代码省略.........

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

        if (m_opcode.GetData(data, address_class))
        {
            char out_string[512];
            
            ::LLVMDisasmContextRef disasm_context;
            
            if (address_class == eAddressClassCodeAlternateISA)
                disasm_context = m_disasm.m_alternate_disasm_context;
            else
                disasm_context = m_disasm.m_disasm_context;
            
            lldb::addr_t pc = LLDB_INVALID_ADDRESS;
            
            if (exe_ctx)
            {
                Target *target = exe_ctx->GetTargetPtr();
                if (target)
                    pc = m_address.GetLoadAddress(target);
            }
            
            if (pc == LLDB_INVALID_ADDRESS)
                pc = m_address.GetFileAddress();
            
            m_disasm.Lock(this, exe_ctx);
            uint8_t *opcode_data = const_cast<uint8_t *>(data.PeekData (0, 1));
            const size_t opcode_data_len = data.GetByteSize();
            size_t inst_size = ::LLVMDisasmInstruction (disasm_context,
                                                        opcode_data,
                                                        opcode_data_len,
                                                        pc,
                                                        out_string,
                                                        sizeof(out_string));
            
            m_disasm.Unlock();
            
            if (inst_size == 0)
            {
                m_comment.assign ("unknown opcode");
                inst_size = m_opcode.GetByteSize();
                StreamString mnemonic_strm;
                uint32_t offset = 0;
                switch (inst_size)
                {
                    case 1:
                        {
                            const uint8_t uval8 = data.GetU8 (&offset);
                            m_opcode.SetOpcode8 (uval8);
                            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);
                            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);
                            m_opcode_name.assign (".long");
                            mnemonic_strm.Printf("0x%8.8x", uval32);
                        }
                        break;
                    case 8:
                        {
                            const uint64_t uval64 = data.GetU64(&offset);
                            m_opcode.SetOpcode64(uval64);
                            m_opcode_name.assign (".quad");
                            mnemonic_strm.Printf("0x%16.16llx", uval64);
                        }
                        break;
                    default:
                        if (inst_size == 0)
                            return;
                        else
                        {
                            const uint8_t *bytes = data.PeekData(offset, inst_size);
                            if (bytes == NULL)
                                return;
                            m_opcode_name.assign (".byte");
                            m_opcode.SetOpcodeBytes(bytes, inst_size);
                            mnemonic_strm.Printf("0x%2.2x", bytes[0]);
                            for (uint32_t i=1; i<inst_size; ++i)
                                mnemonic_strm.Printf(" 0x%2.2x", bytes[i]);
                        }
                        break;
                }
                m_mnemocics.swap(mnemonic_strm.GetString());
                return;
            }
//.........这里部分代码省略.........

//.........这里部分代码省略.........
        if (exe_ctx)
        {
            Target *target = exe_ctx->GetTargetPtr();
            if (target)
            {
                data.SetByteOrder(target->GetArchitecture().GetByteOrder());
                data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
                break;
            }
        }
        // fallback to host settings
        data.SetByteOrder(lldb::endian::InlHostByteOrder());
        data.SetAddressByteSize(sizeof(void *));
        break;
    }

    // Bail if we encountered any errors
    if (error.Fail())
        return error;

    if (address == LLDB_INVALID_ADDRESS)
    {
        error.SetErrorStringWithFormat ("invalid %s address", address_type == eAddressTypeHost ? "host" : "load");
        return error;
    }

    // If we got here, we need to read the value from memory
    uint32_t byte_size = GetValueByteSize (ast_context, &error);

    // Bail if we encountered any errors getting the byte size
    if (error.Fail())
        return error;

    // Make sure we have enough room within "data", and if we don't make
    // something large enough that does
    if (!data.ValidOffsetForDataOfSize (data_offset, byte_size))
    {
        DataBufferSP data_sp(new DataBufferHeap (data_offset + byte_size, '\0'));
        data.SetData(data_sp);
    }

    uint8_t* dst = const_cast<uint8_t*>(data.PeekData (data_offset, byte_size));
    if (dst != NULL)
    {
        if (address_type == eAddressTypeHost)
        {
            // The address is an address in this process, so just copy it
            memcpy (dst, (uint8_t*)NULL + address, byte_size);
        }
        else if ((address_type == eAddressTypeLoad) || (address_type == eAddressTypeFile))
        {
            if (file_so_addr.IsValid())
            {
                // We have a file address that we were able to translate into a
                // section offset address so we might be able to read this from
                // the object files if we don't have a live process. Lets always
                // try and read from the process if we have one though since we
                // want to read the actual value by setting "prefer_file_cache"
                // to false. 
                const bool prefer_file_cache = false;
                if (exe_ctx->GetTargetRef().ReadMemory(file_so_addr, prefer_file_cache, dst, byte_size, error) != byte_size)
                {
                    error.SetErrorStringWithFormat("read memory from 0x%llx failed", (uint64_t)address);
                }
            }
            else
            {
                // The execution context might have a NULL process, but it
                // might have a valid process in the exe_ctx->target, so use
                // the ExecutionContext::GetProcess accessor to ensure we
                // get the process if there is one.
                Process *process = exe_ctx->GetProcessPtr();

                if (process)
                {
                    const size_t bytes_read = process->ReadMemory(address, dst, byte_size, error);
                    if (bytes_read != byte_size)
                        error.SetErrorStringWithFormat("read memory from 0x%llx failed (%u of %u bytes read)", 
                                                       (uint64_t)address, 
                                                       (uint32_t)bytes_read, 
                                                       (uint32_t)byte_size);
                }
                else
                {
                    error.SetErrorStringWithFormat("read memory from 0x%llx failed (invalid process)", (uint64_t)address);                    
                }
            }
        }
        else
        {
            error.SetErrorStringWithFormat ("unsupported AddressType value (%i)", address_type);
        }
    }
    else
    {
        error.SetErrorStringWithFormat ("out of memory");
    }

    return error;
}

bool
DWARFFormValue::ExtractValue(const DataExtractor& data, lldb::offset_t* offset_ptr, const DWARFCompileUnit* cu)
{
    bool indirect = false;
    bool is_block = false;
    m_value.data = NULL;
    // Read the value for the form into value and follow and DW_FORM_indirect instances we run into
    do
    {
        indirect = false;
        switch (m_form)
        {
        case DW_FORM_addr:      m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::GetAddressByteSize(cu));  break;
        case DW_FORM_block2:    m_value.value.uval = data.GetU16(offset_ptr); is_block = true;          break;
        case DW_FORM_block4:    m_value.value.uval = data.GetU32(offset_ptr); is_block = true;          break;
        case DW_FORM_data2:     m_value.value.uval = data.GetU16(offset_ptr);                           break;
        case DW_FORM_data4:     m_value.value.uval = data.GetU32(offset_ptr);                           break;
        case DW_FORM_data8:     m_value.value.uval = data.GetU64(offset_ptr);                           break;
        case DW_FORM_string:    m_value.value.cstr = data.GetCStr(offset_ptr);
                                // Set the string value to also be the data for inlined cstr form values only
                                // so we can tell the differnence between DW_FORM_string and DW_FORM_strp form
                                // values;
                                m_value.data = (uint8_t*)m_value.value.cstr;                            break;
        case DW_FORM_exprloc:
        case DW_FORM_block:     m_value.value.uval = data.GetULEB128(offset_ptr); is_block = true;      break;
        case DW_FORM_block1:    m_value.value.uval = data.GetU8(offset_ptr); is_block = true;           break;
        case DW_FORM_data1:     m_value.value.uval = data.GetU8(offset_ptr);                            break;
        case DW_FORM_flag:      m_value.value.uval = data.GetU8(offset_ptr);                            break;
        case DW_FORM_sdata:     m_value.value.sval = data.GetSLEB128(offset_ptr);                       break;
        case DW_FORM_strp:      m_value.value.uval = data.GetU32(offset_ptr);                           break;
    //  case DW_FORM_APPLE_db_str:
        case DW_FORM_udata:     m_value.value.uval = data.GetULEB128(offset_ptr);                       break;
        case DW_FORM_ref_addr:
            if (cu->GetVersion() <= 2)
                m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::GetAddressByteSize(cu));
            else
                m_value.value.uval = data.GetU32(offset_ptr); // 4 for DWARF32, 8 for DWARF64, but we don't support DWARF64 yet
            break;
        case DW_FORM_ref1:      m_value.value.uval = data.GetU8(offset_ptr);                            break;
        case DW_FORM_ref2:      m_value.value.uval = data.GetU16(offset_ptr);                           break;
        case DW_FORM_ref4:      m_value.value.uval = data.GetU32(offset_ptr);                           break;
        case DW_FORM_ref8:      m_value.value.uval = data.GetU64(offset_ptr);                           break;
        case DW_FORM_ref_udata: m_value.value.uval = data.GetULEB128(offset_ptr);                       break;
        case DW_FORM_indirect:
            m_form = data.GetULEB128(offset_ptr);
            indirect = true;
            break;

        case DW_FORM_sec_offset:    m_value.value.uval = data.GetU32(offset_ptr);                       break;
        case DW_FORM_flag_present:  m_value.value.uval = 1;                                             break;
        case DW_FORM_ref_sig8:      m_value.value.uval = data.GetU64(offset_ptr);                       break;
        default:
            return false;
            break;
        }
    } while (indirect);

    if (is_block)
    {
        m_value.data = data.PeekData(*offset_ptr, m_value.value.uval);
        if (m_value.data != NULL)
        {
            *offset_ptr += m_value.value.uval;
        }
    }

    return true;
}