teak-llvm/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerCommon.cpp

//===-- GDBRemoteCommunicationServerCommon.cpp ------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "GDBRemoteCommunicationServerCommon.h"

#include <errno.h>

// C Includes
// C++ Includes
#include <cstring>
#include <chrono>

// Other libraries and framework includes
#include "llvm/ADT/Triple.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/StreamGDBRemote.h"
#include "lldb/Core/StreamString.h"
#include "lldb/Host/Config.h"
#include "lldb/Host/Endian.h"
#include "lldb/Host/File.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/Host.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Host/StringConvert.h"
#include "lldb/Interpreter/Args.h"
#include "lldb/Target/FileAction.h"
#include "lldb/Target/Platform.h"
#include "lldb/Target/Process.h"

// Project includes
#include "ProcessGDBRemoteLog.h"
#include "Utility/StringExtractorGDBRemote.h"

using namespace lldb;
using namespace lldb_private;

//----------------------------------------------------------------------
// GDBRemoteCommunicationServerCommon constructor
//----------------------------------------------------------------------
GDBRemoteCommunicationServerCommon::GDBRemoteCommunicationServerCommon(const char *comm_name, const char *listener_name) :
    GDBRemoteCommunicationServer (comm_name, listener_name),
    m_spawned_pids (),
    m_spawned_pids_mutex (Mutex::eMutexTypeRecursive),
    m_process_launch_info (),
    m_process_launch_error (),
    m_proc_infos (),
    m_proc_infos_index (0),
    m_thread_suffix_supported (false),
    m_list_threads_in_stop_reply (false)
{
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_A,
                                  &GDBRemoteCommunicationServerCommon::Handle_A);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_QEnvironment,
                                  &GDBRemoteCommunicationServerCommon::Handle_QEnvironment);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qfProcessInfo,
                                  &GDBRemoteCommunicationServerCommon::Handle_qfProcessInfo);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qGroupName,
                                  &GDBRemoteCommunicationServerCommon::Handle_qGroupName);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qHostInfo,
                                  &GDBRemoteCommunicationServerCommon::Handle_qHostInfo);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qKillSpawnedProcess,
                                  &GDBRemoteCommunicationServerCommon::Handle_qKillSpawnedProcess);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_QLaunchArch,
                                  &GDBRemoteCommunicationServerCommon::Handle_QLaunchArch);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qLaunchSuccess,
                                  &GDBRemoteCommunicationServerCommon::Handle_qLaunchSuccess);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_QListThreadsInStopReply,
                                  &GDBRemoteCommunicationServerCommon::Handle_QListThreadsInStopReply);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qPlatform_chmod,
                                  &GDBRemoteCommunicationServerCommon::Handle_qPlatform_chmod);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qPlatform_mkdir,
                                  &GDBRemoteCommunicationServerCommon::Handle_qPlatform_mkdir);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qPlatform_shell,
                                  &GDBRemoteCommunicationServerCommon::Handle_qPlatform_shell);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qProcessInfoPID,
                                  &GDBRemoteCommunicationServerCommon::Handle_qProcessInfoPID);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_QSetDetachOnError,
                                  &GDBRemoteCommunicationServerCommon::Handle_QSetDetachOnError);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_QSetSTDERR,
                                  &GDBRemoteCommunicationServerCommon::Handle_QSetSTDERR);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_QSetSTDIN,
                                  &GDBRemoteCommunicationServerCommon::Handle_QSetSTDIN);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_QSetSTDOUT,
                                  &GDBRemoteCommunicationServerCommon::Handle_QSetSTDOUT);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qSpeedTest,
                                  &GDBRemoteCommunicationServerCommon::Handle_qSpeedTest);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qsProcessInfo,
                                  &GDBRemoteCommunicationServerCommon::Handle_qsProcessInfo);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_QStartNoAckMode,
                                  &GDBRemoteCommunicationServerCommon::Handle_QStartNoAckMode);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qSupported,
                                  &GDBRemoteCommunicationServerCommon::Handle_qSupported);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_QThreadSuffixSupported,
                                  &GDBRemoteCommunicationServerCommon::Handle_QThreadSuffixSupported);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_qUserName,
                                  &GDBRemoteCommunicationServerCommon::Handle_qUserName);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_vFile_close,
                                  &GDBRemoteCommunicationServerCommon::Handle_vFile_Close);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_vFile_exists,
                                  &GDBRemoteCommunicationServerCommon::Handle_vFile_Exists);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_vFile_md5,
                                  &GDBRemoteCommunicationServerCommon::Handle_vFile_MD5);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_vFile_mode,
                                  &GDBRemoteCommunicationServerCommon::Handle_vFile_Mode);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_vFile_open,
                                  &GDBRemoteCommunicationServerCommon::Handle_vFile_Open);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_vFile_pread,
                                  &GDBRemoteCommunicationServerCommon::Handle_vFile_pRead);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_vFile_pwrite,
                                  &GDBRemoteCommunicationServerCommon::Handle_vFile_pWrite);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_vFile_size,
                                  &GDBRemoteCommunicationServerCommon::Handle_vFile_Size);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_vFile_stat,
                                  &GDBRemoteCommunicationServerCommon::Handle_vFile_Stat);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_vFile_symlink,
                                  &GDBRemoteCommunicationServerCommon::Handle_vFile_symlink);
    RegisterMemberFunctionHandler(StringExtractorGDBRemote::eServerPacketType_vFile_unlink,
                                  &GDBRemoteCommunicationServerCommon::Handle_vFile_unlink);
}

//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
GDBRemoteCommunicationServerCommon::~GDBRemoteCommunicationServerCommon()
{
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qHostInfo (StringExtractorGDBRemote &packet)
{
    StreamString response;

    // $cputype:16777223;cpusubtype:3;ostype:Darwin;vendor:apple;endian:little;ptrsize:8;#00

    ArchSpec host_arch(HostInfo::GetArchitecture());
    const llvm::Triple &host_triple = host_arch.GetTriple();
    response.PutCString("triple:");
    response.PutCStringAsRawHex8(host_triple.getTriple().c_str());
    response.Printf (";ptrsize:%u;",host_arch.GetAddressByteSize());

    const char* distribution_id = host_arch.GetDistributionId ().AsCString ();
    if (distribution_id)
    {
        response.PutCString("distribution_id:");
        response.PutCStringAsRawHex8(distribution_id);
        response.PutCString(";");
    }

    // Only send out MachO info when lldb-platform/llgs is running on a MachO host.
#if defined(__APPLE__)
    uint32_t cpu = host_arch.GetMachOCPUType();
    uint32_t sub = host_arch.GetMachOCPUSubType();
    if (cpu != LLDB_INVALID_CPUTYPE)
        response.Printf ("cputype:%u;", cpu);
    if (sub != LLDB_INVALID_CPUTYPE)
        response.Printf ("cpusubtype:%u;", sub);

    if (cpu == ArchSpec::kCore_arm_any)
        response.Printf("watchpoint_exceptions_received:before;");   // On armv7 we use "synchronous" watchpoints which means the exception is delivered before the instruction executes.
    else
        response.Printf("watchpoint_exceptions_received:after;");
#else
    response.Printf("watchpoint_exceptions_received:after;");
#endif

    switch (lldb::endian::InlHostByteOrder())
    {
    case eByteOrderBig:     response.PutCString ("endian:big;"); break;
    case eByteOrderLittle:  response.PutCString ("endian:little;"); break;
    case eByteOrderPDP:     response.PutCString ("endian:pdp;"); break;
    default:                response.PutCString ("endian:unknown;"); break;
    }

    uint32_t major = UINT32_MAX;
    uint32_t minor = UINT32_MAX;
    uint32_t update = UINT32_MAX;
    if (HostInfo::GetOSVersion(major, minor, update))
    {
        if (major != UINT32_MAX)
        {
            response.Printf("os_version:%u", major);
            if (minor != UINT32_MAX)
            {
                response.Printf(".%u", minor);
                if (update != UINT32_MAX)
                    response.Printf(".%u", update);
            }
            response.PutChar(';');
        }
    }

    std::string s;
    if (HostInfo::GetOSBuildString(s))
    {
        response.PutCString ("os_build:");
        response.PutCStringAsRawHex8(s.c_str());
        response.PutChar(';');
    }
    if (HostInfo::GetOSKernelDescription(s))
    {
        response.PutCString ("os_kernel:");
        response.PutCStringAsRawHex8(s.c_str());
        response.PutChar(';');
    }

#if defined(__APPLE__)

#if defined(__arm__) || defined(__arm64__) || defined(__aarch64__)
    // For iOS devices, we are connected through a USB Mux so we never pretend
    // to actually have a hostname as far as the remote lldb that is connecting
    // to this lldb-platform is concerned
    response.PutCString ("hostname:");
    response.PutCStringAsRawHex8("127.0.0.1");
    response.PutChar(';');
#else   // #if defined(__arm__) || defined(__arm64__) || defined(__aarch64__)
    if (HostInfo::GetHostname(s))
    {
        response.PutCString ("hostname:");
        response.PutCStringAsRawHex8(s.c_str());
        response.PutChar(';');
    }
#endif  // #if defined(__arm__) || defined(__arm64__) || defined(__aarch64__)

#else   // #if defined(__APPLE__)
    if (HostInfo::GetHostname(s))
    {
        response.PutCString ("hostname:");
        response.PutCStringAsRawHex8(s.c_str());
        response.PutChar(';');
    }
#endif  // #if defined(__APPLE__)

    return SendPacketNoLock (response.GetData(), response.GetSize());
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qProcessInfoPID (StringExtractorGDBRemote &packet)
{
    // Packet format: "qProcessInfoPID:%i" where %i is the pid
    packet.SetFilePos (::strlen ("qProcessInfoPID:"));
    lldb::pid_t pid = packet.GetU32 (LLDB_INVALID_PROCESS_ID);
    if (pid != LLDB_INVALID_PROCESS_ID)
    {
        ProcessInstanceInfo proc_info;
        if (Host::GetProcessInfo (pid, proc_info))
        {
            StreamString response;
            CreateProcessInfoResponse (proc_info, response);
            return SendPacketNoLock (response.GetData(), response.GetSize());
        }
    }
    return SendErrorResponse (1);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qfProcessInfo (StringExtractorGDBRemote &packet)
{
    m_proc_infos_index = 0;
    m_proc_infos.Clear();

    ProcessInstanceInfoMatch match_info;
    packet.SetFilePos(::strlen ("qfProcessInfo"));
    if (packet.GetChar() == ':')
    {

        std::string key;
        std::string value;
        while (packet.GetNameColonValue(key, value))
        {
            bool success = true;
            if (key.compare("name") == 0)
            {
                StringExtractor extractor;
                extractor.GetStringRef().swap(value);
                extractor.GetHexByteString (value);
                match_info.GetProcessInfo().GetExecutableFile().SetFile(value.c_str(), false);
            }
            else if (key.compare("name_match") == 0)
            {
                if (value.compare("equals") == 0)
                {
                    match_info.SetNameMatchType (eNameMatchEquals);
                }
                else if (value.compare("starts_with") == 0)
                {
                    match_info.SetNameMatchType (eNameMatchStartsWith);
                }
                else if (value.compare("ends_with") == 0)
                {
                    match_info.SetNameMatchType (eNameMatchEndsWith);
                }
                else if (value.compare("contains") == 0)
                {
                    match_info.SetNameMatchType (eNameMatchContains);
                }
                else if (value.compare("regex") == 0)
                {
                    match_info.SetNameMatchType (eNameMatchRegularExpression);
                }
                else
                {
                    success = false;
                }
            }
            else if (key.compare("pid") == 0)
            {
                match_info.GetProcessInfo().SetProcessID (StringConvert::ToUInt32(value.c_str(), LLDB_INVALID_PROCESS_ID, 0, &success));
            }
            else if (key.compare("parent_pid") == 0)
            {
                match_info.GetProcessInfo().SetParentProcessID (StringConvert::ToUInt32(value.c_str(), LLDB_INVALID_PROCESS_ID, 0, &success));
            }
            else if (key.compare("uid") == 0)
            {
                match_info.GetProcessInfo().SetUserID (StringConvert::ToUInt32(value.c_str(), UINT32_MAX, 0, &success));
            }
            else if (key.compare("gid") == 0)
            {
                match_info.GetProcessInfo().SetGroupID (StringConvert::ToUInt32(value.c_str(), UINT32_MAX, 0, &success));
            }
            else if (key.compare("euid") == 0)
            {
                match_info.GetProcessInfo().SetEffectiveUserID (StringConvert::ToUInt32(value.c_str(), UINT32_MAX, 0, &success));
            }
            else if (key.compare("egid") == 0)
            {
                match_info.GetProcessInfo().SetEffectiveGroupID (StringConvert::ToUInt32(value.c_str(), UINT32_MAX, 0, &success));
            }
            else if (key.compare("all_users") == 0)
            {
                match_info.SetMatchAllUsers(Args::StringToBoolean(value.c_str(), false, &success));
            }
            else if (key.compare("triple") == 0)
            {
                match_info.GetProcessInfo().GetArchitecture().SetTriple (value.c_str(), NULL);
            }
            else
            {
                success = false;
            }

            if (!success)
                return SendErrorResponse (2);
        }
    }

    if (Host::FindProcesses (match_info, m_proc_infos))
    {
        // We found something, return the first item by calling the get
        // subsequent process info packet handler...
        return Handle_qsProcessInfo (packet);
    }
    return SendErrorResponse (3);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qsProcessInfo (StringExtractorGDBRemote &packet)
{
    if (m_proc_infos_index < m_proc_infos.GetSize())
    {
        StreamString response;
        CreateProcessInfoResponse (m_proc_infos.GetProcessInfoAtIndex(m_proc_infos_index), response);
        ++m_proc_infos_index;
        return SendPacketNoLock (response.GetData(), response.GetSize());
    }
    return SendErrorResponse (4);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qUserName (StringExtractorGDBRemote &packet)
{
#if !defined(LLDB_DISABLE_POSIX)
    // Packet format: "qUserName:%i" where %i is the uid
    packet.SetFilePos(::strlen ("qUserName:"));
    uint32_t uid = packet.GetU32 (UINT32_MAX);
    if (uid != UINT32_MAX)
    {
        std::string name;
        if (HostInfo::LookupUserName(uid, name))
        {
            StreamString response;
            response.PutCStringAsRawHex8 (name.c_str());
            return SendPacketNoLock (response.GetData(), response.GetSize());
        }
    }
#endif
    return SendErrorResponse (5);

}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qGroupName (StringExtractorGDBRemote &packet)
{
#if !defined(LLDB_DISABLE_POSIX)
    // Packet format: "qGroupName:%i" where %i is the gid
    packet.SetFilePos(::strlen ("qGroupName:"));
    uint32_t gid = packet.GetU32 (UINT32_MAX);
    if (gid != UINT32_MAX)
    {
        std::string name;
        if (HostInfo::LookupGroupName(gid, name))
        {
            StreamString response;
            response.PutCStringAsRawHex8 (name.c_str());
            return SendPacketNoLock (response.GetData(), response.GetSize());
        }
    }
#endif
    return SendErrorResponse (6);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qSpeedTest (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen ("qSpeedTest:"));

    std::string key;
    std::string value;
    bool success = packet.GetNameColonValue(key, value);
    if (success && key.compare("response_size") == 0)
    {
        uint32_t response_size = StringConvert::ToUInt32(value.c_str(), 0, 0, &success);
        if (success)
        {
            if (response_size == 0)
                return SendOKResponse();
            StreamString response;
            uint32_t bytes_left = response_size;
            response.PutCString("data:");
            while (bytes_left > 0)
            {
                if (bytes_left >= 26)
                {
                    response.PutCString("ABCDEFGHIJKLMNOPQRSTUVWXYZ");
                    bytes_left -= 26;
                }
                else
                {
                    response.Printf ("%*.*s;", bytes_left, bytes_left, "ABCDEFGHIJKLMNOPQRSTUVWXYZ");
                    bytes_left = 0;
                }
            }
            return SendPacketNoLock (response.GetData(), response.GetSize());
        }
    }
    return SendErrorResponse (7);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qKillSpawnedProcess (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen ("qKillSpawnedProcess:"));

    lldb::pid_t pid = packet.GetU64(LLDB_INVALID_PROCESS_ID);

    // verify that we know anything about this pid.
    // Scope for locker
    {
        Mutex::Locker locker (m_spawned_pids_mutex);
        if (m_spawned_pids.find(pid) == m_spawned_pids.end())
        {
            // not a pid we know about
            return SendErrorResponse (10);
        }
    }

    // go ahead and attempt to kill the spawned process
    if (KillSpawnedProcess (pid))
        return SendOKResponse ();
    else
        return SendErrorResponse (11);
}

bool
GDBRemoteCommunicationServerCommon::KillSpawnedProcess (lldb::pid_t pid)
{
    // make sure we know about this process
    {
        Mutex::Locker locker (m_spawned_pids_mutex);
        if (m_spawned_pids.find(pid) == m_spawned_pids.end())
            return false;
    }

    // first try a SIGTERM (standard kill)
    Host::Kill (pid, SIGTERM);

    // check if that worked
    for (size_t i=0; i<10; ++i)
    {
        {
            Mutex::Locker locker (m_spawned_pids_mutex);
            if (m_spawned_pids.find(pid) == m_spawned_pids.end())
            {
                // it is now killed
                return true;
            }
        }
        usleep (10000);
    }

    // check one more time after the final usleep
    {
        Mutex::Locker locker (m_spawned_pids_mutex);
        if (m_spawned_pids.find(pid) == m_spawned_pids.end())
            return true;
    }

    // the launched process still lives.  Now try killing it again,
    // this time with an unblockable signal.
    Host::Kill (pid, SIGKILL);

    for (size_t i=0; i<10; ++i)
    {
        {
            Mutex::Locker locker (m_spawned_pids_mutex);
            if (m_spawned_pids.find(pid) == m_spawned_pids.end())
            {
                // it is now killed
                return true;
            }
        }
        usleep (10000);
    }

    // check one more time after the final usleep
    // Scope for locker
    {
        Mutex::Locker locker (m_spawned_pids_mutex);
        if (m_spawned_pids.find(pid) == m_spawned_pids.end())
            return true;
    }

    // no luck - the process still lives
    return false;
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_vFile_Open (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen("vFile:open:"));
    std::string path;
    packet.GetHexByteStringTerminatedBy(path,',');
    if (!path.empty())
    {
        if (packet.GetChar() == ',')
        {
            uint32_t flags = packet.GetHexMaxU32(false, 0);
            if (packet.GetChar() == ',')
            {
                mode_t mode = packet.GetHexMaxU32(false, 0600);
                Error error;
                int fd = ::open (path.c_str(), flags, mode);
                const int save_errno = fd == -1 ? errno : 0;
                StreamString response;
                response.PutChar('F');
                response.Printf("%i", fd);
                if (save_errno)
                    response.Printf(",%i", save_errno);
                return SendPacketNoLock(response.GetData(), response.GetSize());
            }
        }
    }
    return SendErrorResponse(18);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_vFile_Close (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen("vFile:close:"));
    int fd = packet.GetS32(-1);
    Error error;
    int err = -1;
    int save_errno = 0;
    if (fd >= 0)
    {
        err = close(fd);
        save_errno = err == -1 ? errno : 0;
    }
    else
    {
        save_errno = EINVAL;
    }
    StreamString response;
    response.PutChar('F');
    response.Printf("%i", err);
    if (save_errno)
        response.Printf(",%i", save_errno);
    return SendPacketNoLock(response.GetData(), response.GetSize());
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_vFile_pRead (StringExtractorGDBRemote &packet)
{
#ifdef _WIN32
    // Not implemented on Windows
    return SendUnimplementedResponse("GDBRemoteCommunicationServerCommon::Handle_vFile_pRead() unimplemented");
#else
    StreamGDBRemote response;
    packet.SetFilePos(::strlen("vFile:pread:"));
    int fd = packet.GetS32(-1);
    if (packet.GetChar() == ',')
    {
        uint64_t count = packet.GetU64(UINT64_MAX);
        if (packet.GetChar() == ',')
        {
            uint64_t offset = packet.GetU64(UINT32_MAX);
            if (count == UINT64_MAX)
            {
                response.Printf("F-1:%i", EINVAL);
                return SendPacketNoLock(response.GetData(), response.GetSize());
            }

            std::string buffer(count, 0);
            const ssize_t bytes_read = ::pread (fd, &buffer[0], buffer.size(), offset);
            const int save_errno = bytes_read == -1 ? errno : 0;
            response.PutChar('F');
            response.Printf("%zi", bytes_read);
            if (save_errno)
                response.Printf(",%i", save_errno);
            else
            {
                response.PutChar(';');
                response.PutEscapedBytes(&buffer[0], bytes_read);
            }
            return SendPacketNoLock(response.GetData(), response.GetSize());
        }
    }
    return SendErrorResponse(21);

#endif
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_vFile_pWrite (StringExtractorGDBRemote &packet)
{
#ifdef _WIN32
    return SendUnimplementedResponse("GDBRemoteCommunicationServerCommon::Handle_vFile_pWrite() unimplemented");
#else
    packet.SetFilePos(::strlen("vFile:pwrite:"));

    StreamGDBRemote response;
    response.PutChar('F');

    int fd = packet.GetU32(UINT32_MAX);
    if (packet.GetChar() == ',')
    {
        off_t offset = packet.GetU64(UINT32_MAX);
        if (packet.GetChar() == ',')
        {
            std::string buffer;
            if (packet.GetEscapedBinaryData(buffer))
            {
                const ssize_t bytes_written = ::pwrite (fd, buffer.data(), buffer.size(), offset);
                const int save_errno = bytes_written == -1 ? errno : 0;
                response.Printf("%zi", bytes_written);
                if (save_errno)
                    response.Printf(",%i", save_errno);
            }
            else
            {
                response.Printf ("-1,%i", EINVAL);
            }
            return SendPacketNoLock(response.GetData(), response.GetSize());
        }
    }
    return SendErrorResponse(27);
#endif
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_vFile_Size (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen("vFile:size:"));
    std::string path;
    packet.GetHexByteString(path);
    if (!path.empty())
    {
        lldb::user_id_t retcode = FileSystem::GetFileSize(FileSpec(path.c_str(), false));
        StreamString response;
        response.PutChar('F');
        response.PutHex64(retcode);
        if (retcode == UINT64_MAX)
        {
            response.PutChar(',');
            response.PutHex64(retcode); // TODO: replace with Host::GetSyswideErrorCode()
        }
        return SendPacketNoLock(response.GetData(), response.GetSize());
    }
    return SendErrorResponse(22);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_vFile_Mode (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen("vFile:mode:"));
    std::string path;
    packet.GetHexByteString(path);
    if (!path.empty())
    {
        Error error;
        const uint32_t mode = File::GetPermissions(path.c_str(), error);
        StreamString response;
        response.Printf("F%u", mode);
        if (mode == 0 || error.Fail())
            response.Printf(",%i", (int)error.GetError());
        return SendPacketNoLock(response.GetData(), response.GetSize());
    }
    return SendErrorResponse(23);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_vFile_Exists (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen("vFile:exists:"));
    std::string path;
    packet.GetHexByteString(path);
    if (!path.empty())
    {
        bool retcode = FileSystem::GetFileExists(FileSpec(path.c_str(), false));
        StreamString response;
        response.PutChar('F');
        response.PutChar(',');
        if (retcode)
            response.PutChar('1');
        else
            response.PutChar('0');
        return SendPacketNoLock(response.GetData(), response.GetSize());
    }
    return SendErrorResponse(24);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_vFile_symlink (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen("vFile:symlink:"));
    std::string dst, src;
    packet.GetHexByteStringTerminatedBy(dst, ',');
    packet.GetChar(); // Skip ',' char
    packet.GetHexByteString(src);
    Error error = FileSystem::Symlink(src.c_str(), dst.c_str());
    StreamString response;
    response.Printf("F%u,%u", error.GetError(), error.GetError());
    return SendPacketNoLock(response.GetData(), response.GetSize());
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_vFile_unlink (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen("vFile:unlink:"));
    std::string path;
    packet.GetHexByteString(path);
    Error error = FileSystem::Unlink(path.c_str());
    StreamString response;
    response.Printf("F%u,%u", error.GetError(), error.GetError());
    return SendPacketNoLock(response.GetData(), response.GetSize());
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qPlatform_shell (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen("qPlatform_shell:"));
    std::string path;
    std::string working_dir;
    packet.GetHexByteStringTerminatedBy(path,',');
    if (!path.empty())
    {
        if (packet.GetChar() == ',')
        {
            // FIXME: add timeout to qPlatform_shell packet
            // uint32_t timeout = packet.GetHexMaxU32(false, 32);
            uint32_t timeout = 10;
            if (packet.GetChar() == ',')
                packet.GetHexByteString(working_dir);
            int status, signo;
            std::string output;
            Error err = Host::RunShellCommand(path.c_str(),
                                              working_dir.empty() ? NULL : working_dir.c_str(),
                                              &status, &signo, &output, timeout);
            StreamGDBRemote response;
            if (err.Fail())
            {
                response.PutCString("F,");
                response.PutHex32(UINT32_MAX);
            }
            else
            {
                response.PutCString("F,");
                response.PutHex32(status);
                response.PutChar(',');
                response.PutHex32(signo);
                response.PutChar(',');
                response.PutEscapedBytes(output.c_str(), output.size());
            }
            return SendPacketNoLock(response.GetData(), response.GetSize());
        }
    }
    return SendErrorResponse(24);
}


GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_vFile_Stat (StringExtractorGDBRemote &packet)
{
    return SendUnimplementedResponse("GDBRemoteCommunicationServerCommon::Handle_vFile_Stat() unimplemented");
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_vFile_MD5 (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen("vFile:MD5:"));
    std::string path;
    packet.GetHexByteString(path);
    if (!path.empty())
    {
        uint64_t a,b;
        StreamGDBRemote response;
        if (FileSystem::CalculateMD5(FileSpec(path.c_str(), false), a, b) == false)
        {
            response.PutCString("F,");
            response.PutCString("x");
        }
        else
        {
            response.PutCString("F,");
            response.PutHex64(a);
            response.PutHex64(b);
        }
        return SendPacketNoLock(response.GetData(), response.GetSize());
    }
    return SendErrorResponse(25);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qPlatform_mkdir (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen("qPlatform_mkdir:"));
    mode_t mode = packet.GetHexMaxU32(false, UINT32_MAX);
    if (packet.GetChar() == ',')
    {
        std::string path;
        packet.GetHexByteString(path);
        Error error = FileSystem::MakeDirectory(path.c_str(), mode);
        
        StreamGDBRemote response;
        response.Printf("F%u", error.GetError());

        return SendPacketNoLock(response.GetData(), response.GetSize());
    }
    return SendErrorResponse(20);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qPlatform_chmod (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen("qPlatform_chmod:"));

    mode_t mode = packet.GetHexMaxU32(false, UINT32_MAX);
    if (packet.GetChar() == ',')
    {
        std::string path;
        packet.GetHexByteString(path);
        Error error = FileSystem::SetFilePermissions(path.c_str(), mode);

        StreamGDBRemote response;
        response.Printf("F%u", error.GetError());

        return SendPacketNoLock(response.GetData(), response.GetSize());
    }
    return SendErrorResponse(19);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qSupported (StringExtractorGDBRemote &packet)
{
    StreamGDBRemote response;

    // Features common to lldb-platform and llgs.
    uint32_t max_packet_size = 128 * 1024;  // 128KBytes is a reasonable max packet size--debugger can always use less
    response.Printf ("PacketSize=%x", max_packet_size);

    response.PutCString (";QStartNoAckMode+");
    response.PutCString (";QThreadSuffixSupported+");
    response.PutCString (";QListThreadsInStopReply+");
#if defined(__linux__)
    response.PutCString (";qXfer:auxv:read+");
#endif

    return SendPacketNoLock(response.GetData(), response.GetSize());
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_QThreadSuffixSupported (StringExtractorGDBRemote &packet)
{
    m_thread_suffix_supported = true;
    return SendOKResponse();
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_QListThreadsInStopReply (StringExtractorGDBRemote &packet)
{
    m_list_threads_in_stop_reply = true;
    return SendOKResponse();
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_QSetDetachOnError (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen ("QSetDetachOnError:"));
    if (packet.GetU32(0))
        m_process_launch_info.GetFlags().Set (eLaunchFlagDetachOnError);
    else
        m_process_launch_info.GetFlags().Clear (eLaunchFlagDetachOnError);
    return SendOKResponse ();
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_QStartNoAckMode (StringExtractorGDBRemote &packet)
{
    // Send response first before changing m_send_acks to we ack this packet
    PacketResult packet_result = SendOKResponse ();
    m_send_acks = false;
    return packet_result;
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_QSetSTDIN (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen ("QSetSTDIN:"));
    FileAction file_action;
    std::string path;
    packet.GetHexByteString(path);
    const bool read = false;
    const bool write = true;
    if (file_action.Open(STDIN_FILENO, path.c_str(), read, write))
    {
        m_process_launch_info.AppendFileAction(file_action);
        return SendOKResponse ();
    }
    return SendErrorResponse (15);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_QSetSTDOUT (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen ("QSetSTDOUT:"));
    FileAction file_action;
    std::string path;
    packet.GetHexByteString(path);
    const bool read = true;
    const bool write = false;
    if (file_action.Open(STDOUT_FILENO, path.c_str(), read, write))
    {
        m_process_launch_info.AppendFileAction(file_action);
        return SendOKResponse ();
    }
    return SendErrorResponse (16);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_QSetSTDERR (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen ("QSetSTDERR:"));
    FileAction file_action;
    std::string path;
    packet.GetHexByteString(path);
    const bool read = true;
    const bool write = false;
    if (file_action.Open(STDERR_FILENO, path.c_str(), read, write))
    {
        m_process_launch_info.AppendFileAction(file_action);
        return SendOKResponse ();
    }
    return SendErrorResponse (17);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_qLaunchSuccess (StringExtractorGDBRemote &packet)
{
    if (m_process_launch_error.Success())
        return SendOKResponse();
    StreamString response;
    response.PutChar('E');
    response.PutCString(m_process_launch_error.AsCString("<unknown error>"));
    return SendPacketNoLock (response.GetData(), response.GetSize());
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_QEnvironment (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen ("QEnvironment:"));
    const uint32_t bytes_left = packet.GetBytesLeft();
    if (bytes_left > 0)
    {
        m_process_launch_info.GetEnvironmentEntries ().AppendArgument (packet.Peek());
        return SendOKResponse ();
    }
    return SendErrorResponse (12);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_QLaunchArch (StringExtractorGDBRemote &packet)
{
    packet.SetFilePos(::strlen ("QLaunchArch:"));
    const uint32_t bytes_left = packet.GetBytesLeft();
    if (bytes_left > 0)
    {
        const char* arch_triple = packet.Peek();
        ArchSpec arch_spec(arch_triple,NULL);
        m_process_launch_info.SetArchitecture(arch_spec);
        return SendOKResponse();
    }
    return SendErrorResponse(13);
}

GDBRemoteCommunication::PacketResult
GDBRemoteCommunicationServerCommon::Handle_A (StringExtractorGDBRemote &packet)
{
    // The 'A' packet is the most over designed packet ever here with
    // redundant argument indexes, redundant argument lengths and needed hex
    // encoded argument string values. Really all that is needed is a comma
    // separated hex encoded argument value list, but we will stay true to the
    // documented version of the 'A' packet here...

    Log *log (GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS));
    int actual_arg_index = 0;

    packet.SetFilePos(1); // Skip the 'A'
    bool success = true;
    while (success && packet.GetBytesLeft() > 0)
    {
        // Decode the decimal argument string length. This length is the
        // number of hex nibbles in the argument string value.
        const uint32_t arg_len = packet.GetU32(UINT32_MAX);
        if (arg_len == UINT32_MAX)
            success = false;
        else
        {
            // Make sure the argument hex string length is followed by a comma
            if (packet.GetChar() != ',')
                success = false;
            else
            {
                // Decode the argument index. We ignore this really because
                // who would really send down the arguments in a random order???
                const uint32_t arg_idx = packet.GetU32(UINT32_MAX);
                if (arg_idx == UINT32_MAX)
                    success = false;
                else
                {
                    // Make sure the argument index is followed by a comma
                    if (packet.GetChar() != ',')
                        success = false;
                    else
                    {
                        // Decode the argument string value from hex bytes
                        // back into a UTF8 string and make sure the length
                        // matches the one supplied in the packet
                        std::string arg;
                        if (packet.GetHexByteStringFixedLength(arg, arg_len) != (arg_len / 2))
                            success = false;
                        else
                        {
                            // If there are any bytes left
                            if (packet.GetBytesLeft())
                            {
                                if (packet.GetChar() != ',')
                                    success = false;
                            }

                            if (success)
                            {
                                if (arg_idx == 0)
                                    m_process_launch_info.GetExecutableFile().SetFile(arg.c_str(), false);
                                m_process_launch_info.GetArguments().AppendArgument(arg.c_str());
                                if (log)
                                    log->Printf ("LLGSPacketHandler::%s added arg %d: \"%s\"", __FUNCTION__, actual_arg_index, arg.c_str ());
                                ++actual_arg_index;
                            }
                        }
                    }
                }
            }
        }
    }

    if (success)
    {
        m_process_launch_error = LaunchProcess ();
        if (m_process_launch_info.GetProcessID() != LLDB_INVALID_PROCESS_ID)
        {
            return SendOKResponse ();
        }
        else
        {
            Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS));
            if (log)
                log->Printf("LLGSPacketHandler::%s failed to launch exe: %s",
                        __FUNCTION__,
                        m_process_launch_error.AsCString());

        }
    }
    return SendErrorResponse (8);
}

void
GDBRemoteCommunicationServerCommon::CreateProcessInfoResponse (const ProcessInstanceInfo &proc_info,
                                                    StreamString &response)
{
    response.Printf ("pid:%" PRIu64 ";ppid:%" PRIu64 ";uid:%i;gid:%i;euid:%i;egid:%i;",
                     proc_info.GetProcessID(),
                     proc_info.GetParentProcessID(),
                     proc_info.GetUserID(),
                     proc_info.GetGroupID(),
                     proc_info.GetEffectiveUserID(),
                     proc_info.GetEffectiveGroupID());
    response.PutCString ("name:");
    response.PutCStringAsRawHex8(proc_info.GetName());
    response.PutChar(';');
    const ArchSpec &proc_arch = proc_info.GetArchitecture();
    if (proc_arch.IsValid())
    {
        const llvm::Triple &proc_triple = proc_arch.GetTriple();
        response.PutCString("triple:");
        response.PutCStringAsRawHex8(proc_triple.getTriple().c_str());
        response.PutChar(';');
    }
}

void
GDBRemoteCommunicationServerCommon::CreateProcessInfoResponse_DebugServerStyle (
    const ProcessInstanceInfo &proc_info, StreamString &response)
{
    response.Printf ("pid:%" PRIx64 ";parent-pid:%" PRIx64 ";real-uid:%x;real-gid:%x;effective-uid:%x;effective-gid:%x;",
                     proc_info.GetProcessID(),
                     proc_info.GetParentProcessID(),
                     proc_info.GetUserID(),
                     proc_info.GetGroupID(),
                     proc_info.GetEffectiveUserID(),
                     proc_info.GetEffectiveGroupID());

    const ArchSpec &proc_arch = proc_info.GetArchitecture();
    if (proc_arch.IsValid())
    {
        const llvm::Triple &proc_triple = proc_arch.GetTriple();
#if defined(__APPLE__)
        // We'll send cputype/cpusubtype.
        const uint32_t cpu_type = proc_arch.GetMachOCPUType();
        if (cpu_type != 0)
            response.Printf ("cputype:%" PRIx32 ";", cpu_type);

        const uint32_t cpu_subtype = proc_arch.GetMachOCPUSubType();
        if (cpu_subtype != 0)
            response.Printf ("cpusubtype:%" PRIx32 ";", cpu_subtype);

        const std::string vendor = proc_triple.getVendorName ();
        if (!vendor.empty ())
            response.Printf ("vendor:%s;", vendor.c_str ());
#else
        // We'll send the triple.
        response.PutCString("triple:");
        response.PutCStringAsRawHex8(proc_triple.getTriple().c_str());
        response.PutChar(';');
#endif
        std::string ostype = proc_triple.getOSName ();
        // Adjust so ostype reports ios for Apple/ARM and Apple/ARM64.
        if (proc_triple.getVendor () == llvm::Triple::Apple)
        {
            switch (proc_triple.getArch ())
            {
                case llvm::Triple::arm:
                case llvm::Triple::aarch64:
                    ostype = "ios";
                    break;
                default:
                    // No change.
                    break;
            }
        }
        response.Printf ("ostype:%s;", ostype.c_str ());


        switch (proc_arch.GetByteOrder ())
        {
            case lldb::eByteOrderLittle: response.PutCString ("endian:little;"); break;
            case lldb::eByteOrderBig:    response.PutCString ("endian:big;");    break;
            case lldb::eByteOrderPDP:    response.PutCString ("endian:pdp;");    break;
            default:
                // Nothing.
                break;
        }

        if (proc_triple.isArch64Bit ())
            response.PutCString ("ptrsize:8;");
        else if (proc_triple.isArch32Bit ())
            response.PutCString ("ptrsize:4;");
        else if (proc_triple.isArch16Bit ())
            response.PutCString ("ptrsize:2;");
    }
}