C++ ProcessLaunchInfo::GetFlags方法代码示例

short
Host::GetPosixspawnFlags (ProcessLaunchInfo &launch_info)
{
#ifndef __ANDROID__
    short flags = POSIX_SPAWN_SETSIGDEF | POSIX_SPAWN_SETSIGMASK;

#if defined (__APPLE__)
    if (launch_info.GetFlags().Test (eLaunchFlagExec))
        flags |= POSIX_SPAWN_SETEXEC;           // Darwin specific posix_spawn flag
    
    if (launch_info.GetFlags().Test (eLaunchFlagDebug))
        flags |= POSIX_SPAWN_START_SUSPENDED;   // Darwin specific posix_spawn flag
    
    if (launch_info.GetFlags().Test (eLaunchFlagDisableASLR))
        flags |= _POSIX_SPAWN_DISABLE_ASLR;     // Darwin specific posix_spawn flag
        
    if (launch_info.GetLaunchInSeparateProcessGroup())
        flags |= POSIX_SPAWN_SETPGROUP;
    
#ifdef POSIX_SPAWN_CLOEXEC_DEFAULT
#if defined (__APPLE__) && (defined (__x86_64__) || defined (__i386__))
    static LazyBool g_use_close_on_exec_flag = eLazyBoolCalculate;
    if (g_use_close_on_exec_flag == eLazyBoolCalculate)
    {
        g_use_close_on_exec_flag = eLazyBoolNo;
        
        uint32_t major, minor, update;
        if (HostInfo::GetOSVersion(major, minor, update))
        {
            // Kernel panic if we use the POSIX_SPAWN_CLOEXEC_DEFAULT on 10.7 or earlier
            if (major > 10 || (major == 10 && minor > 7))
            {
                // Only enable for 10.8 and later OS versions
                g_use_close_on_exec_flag = eLazyBoolYes;
            }
        }
    }
#else
    static LazyBool g_use_close_on_exec_flag = eLazyBoolYes;
#endif
    // Close all files exception those with file actions if this is supported.
    if (g_use_close_on_exec_flag == eLazyBoolYes)
        flags |= POSIX_SPAWN_CLOEXEC_DEFAULT;
#endif
#endif // #if defined (__APPLE__)
    return flags;
#else
    assert(false *&& "Host::GetPosixspawnFlags() not supported on Android");
    return 0;
#endif
}

lldb::ProcessSP
PlatformPOSIX::DebugProcess (ProcessLaunchInfo &launch_info,
                              Debugger &debugger,
                              Target *target,       // Can be NULL, if NULL create a new target, else use existing one
                              Error &error)
{
    ProcessSP process_sp;

    if (IsHost())
    {
        // We are going to hand this process off to debugserver which will be in charge of setting the exit status.
        // We still need to reap it from lldb but if we let the monitor thread also set the exit status, we set up a
        // race between debugserver & us for who will find out about the debugged process's death.
        launch_info.GetFlags().Set(eLaunchFlagDontSetExitStatus);
        process_sp = Platform::DebugProcess (launch_info, debugger, target, error);
    }
    else
    {
        if (m_remote_platform_sp)
            process_sp = m_remote_platform_sp->DebugProcess (launch_info, debugger, target, error);
        else
            error.SetErrorString ("the platform is not currently connected");
    }
    return process_sp;

}

int32_t
PlatformNetBSD::GetResumeCountForLaunchInfo(ProcessLaunchInfo &launch_info) {
  int32_t resume_count = 0;

  // Always resume past the initial stop when we use eLaunchFlagDebug
  if (launch_info.GetFlags().Test(eLaunchFlagDebug)) {
    // Resume past the stop for the final exec into the true inferior.
    ++resume_count;
  }

  // If we're not launching a shell, we're done.
  const FileSpec &shell = launch_info.GetShell();
  if (!shell)
    return resume_count;

  std::string shell_string = shell.GetPath();
  // We're in a shell, so for sure we have to resume past the shell exec.
  ++resume_count;

  // Figure out what shell we're planning on using.
  const char *shell_name = strrchr(shell_string.c_str(), '/');
  if (shell_name == NULL)
    shell_name = shell_string.c_str();
  else
    shell_name++;

  if (strcmp(shell_name, "csh") == 0 || strcmp(shell_name, "tcsh") == 0 ||
      strcmp(shell_name, "zsh") == 0 || strcmp(shell_name, "sh") == 0) {
    // These shells seem to re-exec themselves.  Add another resume.
    ++resume_count;
  }

  return resume_count;
}

Error
PlatformRemoteGDBServer::LaunchProcess (ProcessLaunchInfo &launch_info)
{
    Error error;
    lldb::pid_t pid = LLDB_INVALID_PROCESS_ID;
    
    m_gdb_client.SetSTDIN ("/dev/null");
    m_gdb_client.SetSTDOUT ("/dev/null");
    m_gdb_client.SetSTDERR ("/dev/null");
    m_gdb_client.SetDisableASLR (launch_info.GetFlags().Test (eLaunchFlagDisableASLR));
    
    const char *working_dir = launch_info.GetWorkingDirectory();
    if (working_dir && working_dir[0])
    {
        m_gdb_client.SetWorkingDir (working_dir);
    }
    
    // Send the environment and the program + arguments after we connect
    const char **envp = launch_info.GetEnvironmentEntries().GetConstArgumentVector();

    if (envp)
    {
        const char *env_entry;
        for (int i=0; (env_entry = envp[i]); ++i)
        {
            if (m_gdb_client.SendEnvironmentPacket(env_entry) != 0)
                break;
        }
    }
    
    ArchSpec arch_spec = launch_info.GetArchitecture();
    const char *arch_triple = arch_spec.GetTriple().str().c_str();
    
    m_gdb_client.SendLaunchArchPacket(arch_triple);
    
    const uint32_t old_packet_timeout = m_gdb_client.SetPacketTimeout (5);
    int arg_packet_err = m_gdb_client.SendArgumentsPacket (launch_info);
    m_gdb_client.SetPacketTimeout (old_packet_timeout);
    if (arg_packet_err == 0)
    {
        std::string error_str;
        if (m_gdb_client.GetLaunchSuccess (error_str))
        {
            pid = m_gdb_client.GetCurrentProcessID ();
            if (pid != LLDB_INVALID_PROCESS_ID)
                launch_info.SetProcessID (pid);
        }
        else
        {
            error.SetErrorString (error_str.c_str());
        }
    }
    else
    {
        error.SetErrorStringWithFormat("'A' packet returned an error: %i", arg_packet_err);
    }
    return error;
}

static void DisableASLRIfRequested(int error_fd, const ProcessLaunchInfo &info) {
#if defined(__linux__)
  if (info.GetFlags().Test(lldb::eLaunchFlagDisableASLR)) {
    const unsigned long personality_get_current = 0xffffffff;
    int value = personality(personality_get_current);
    if (value == -1)
      ExitWithError(error_fd, "personality get");

    value = personality(ADDR_NO_RANDOMIZE | value);
    if (value == -1)
      ExitWithError(error_fd, "personality set");
  }
#endif
}

Error
ProcessWindows::DoLaunch(Module *exe_module,
                         ProcessLaunchInfo &launch_info)
{
    // Even though m_session_data is accessed here, it is before a debugger thread has been
    // kicked off.  So there's no race conditions, and it shouldn't be necessary to acquire
    // the mutex.

    Error result;
    if (!launch_info.GetFlags().Test(eLaunchFlagDebug))
    {
        result.SetErrorString("ProcessWindows can only be used to launch processes for debugging.");
        return result;
    }

    m_session_data.reset(new ProcessWindowsData(launch_info));

    SetPrivateState(eStateLaunching);
    DebugDelegateSP delegate(new LocalDebugDelegate(shared_from_this()));
    m_session_data->m_debugger.reset(new DebuggerThread(delegate));
    DebuggerThreadSP debugger = m_session_data->m_debugger;

    // Kick off the DebugLaunch asynchronously and wait for it to complete.
    result = debugger->DebugLaunch(launch_info);

    HostProcess process;
    if (result.Success())
    {
        // Block this function until we receive the initial stop from the process.
        if (::WaitForSingleObject(m_session_data->m_initial_stop_event, INFINITE) == WAIT_OBJECT_0)
        {
            process = debugger->GetProcess();
            if (m_session_data->m_launch_error.Fail())
                result = m_session_data->m_launch_error;
        }
        else
            result.SetError(::GetLastError(), eErrorTypeWin32);
    }

    if (!result.Success())
        return result;

    // We've hit the initial stop.  The private state should already be set to stopped as a result
    // of encountering the breakpoint exception in ProcessWindows::OnDebugException.
    launch_info.SetProcessID(process.GetProcessId());
    SetID(process.GetProcessId());

    return result;
}

lldb::ProcessSP
Platform::DebugProcess (ProcessLaunchInfo &launch_info, 
                        Debugger &debugger,
                        Target *target,       // Can be NULL, if NULL create a new target, else use existing one
                        Listener &listener,
                        Error &error)
{
    ProcessSP process_sp;
    // Make sure we stop at the entry point
    launch_info.GetFlags ().Set (eLaunchFlagDebug);
    // We always launch the process we are going to debug in a separate process
    // group, since then we can handle ^C interrupts ourselves w/o having to worry
    // about the target getting them as well.
    launch_info.SetLaunchInSeparateProcessGroup(true);
    
    error = LaunchProcess (launch_info);
    if (error.Success())
    {
        if (launch_info.GetProcessID() != LLDB_INVALID_PROCESS_ID)
        {
            ProcessAttachInfo attach_info (launch_info);
            process_sp = Attach (attach_info, debugger, target, listener, error);
            if (process_sp)
            {
                launch_info.SetHijackListener(attach_info.GetHijackListener());
                
                // Since we attached to the process, it will think it needs to detach
                // if the process object just goes away without an explicit call to
                // Process::Kill() or Process::Detach(), so let it know to kill the 
                // process if this happens.
                process_sp->SetShouldDetach (false);
                
                // If we didn't have any file actions, the pseudo terminal might
                // have been used where the slave side was given as the file to
                // open for stdin/out/err after we have already opened the master
                // so we can read/write stdin/out/err.
                int pty_fd = launch_info.GetPTY().ReleaseMasterFileDescriptor();
                if (pty_fd != lldb_utility::PseudoTerminal::invalid_fd)
                {
                    process_sp->SetSTDIOFileDescriptor(pty_fd);
                }
            }
        }
    }
    return process_sp;
}

ProcessSP PlatformWindows::DebugProcess(ProcessLaunchInfo &launch_info,
                                        Debugger &debugger, Target *target,
                                        Error &error) {
  // Windows has special considerations that must be followed when launching or
  // attaching to a process.  The
  // key requirement is that when launching or attaching to a process, you must
  // do it from the same the thread
  // that will go into a permanent loop which will then receive debug events
  // from the process.  In particular,
  // this means we can't use any of LLDB's generic mechanisms to do it for us,
  // because it doesn't have the
  // special knowledge required for setting up the background thread or passing
  // the right flags.
  //
  // Another problem is that that LLDB's standard model for debugging a process
  // is to first launch it, have
  // it stop at the entry point, and then attach to it.  In Windows this doesn't
  // quite work, you have to
  // specify as an argument to CreateProcess() that you're going to debug the
  // process.  So we override DebugProcess
  // here to handle this.  Launch operations go directly to the process plugin,
  // and attach operations almost go
  // directly to the process plugin (but we hijack the events first).  In
  // essence, we encapsulate all the logic
  // of Launching and Attaching in the process plugin, and
  // PlatformWindows::DebugProcess is just a pass-through
  // to get to the process plugin.

  if (launch_info.GetProcessID() != LLDB_INVALID_PROCESS_ID) {
    // This is a process attach.  Don't need to launch anything.
    ProcessAttachInfo attach_info(launch_info);
    return Attach(attach_info, debugger, target, error);
  } else {
    ProcessSP process_sp =
        target->CreateProcess(launch_info.GetListenerForProcess(debugger),
                              launch_info.GetProcessPluginName(), nullptr);

    // We need to launch and attach to the process.
    launch_info.GetFlags().Set(eLaunchFlagDebug);
    if (process_sp)
      error = process_sp->Launch(launch_info);

    return process_sp;
  }
}

Error
Host::ShellExpandArguments (ProcessLaunchInfo &launch_info)
{
    Error error;
    if (launch_info.GetFlags().Test(eLaunchFlagShellExpandArguments))
    {
        FileSpec expand_tool_spec;
        if (!HostInfo::GetLLDBPath(lldb::ePathTypeSupportExecutableDir, expand_tool_spec))
        {
            error.SetErrorString("could not find argdumper tool");
            return error;
        }
        expand_tool_spec.AppendPathComponent("argdumper.exe");
        if (!expand_tool_spec.Exists())
        {
            error.SetErrorString("could not find argdumper tool");
            return error;
        }
        
        std::string quoted_cmd_string;
        launch_info.GetArguments().GetQuotedCommandString(quoted_cmd_string);
        std::replace(quoted_cmd_string.begin(), quoted_cmd_string.end(), '\\', '/');
        StreamString expand_command;
        
        expand_command.Printf("%s %s",
                              expand_tool_spec.GetPath().c_str(),
                              quoted_cmd_string.c_str());
        
        int status;
        std::string output;
        RunShellCommand(expand_command.GetData(), launch_info.GetWorkingDirectory(), &status, nullptr, &output, 10);
        
        if (status != 0)
        {
            error.SetErrorStringWithFormat("argdumper exited with error %d", status);
            return error;
        }
        
        auto data_sp = StructuredData::ParseJSON(output);
        if (!data_sp)
        {
            error.SetErrorString("invalid JSON");
            return error;
        }
        
        auto dict_sp = data_sp->GetAsDictionary();
        if (!data_sp)
        {
            error.SetErrorString("invalid JSON");
            return error;
        }
        
        auto args_sp = dict_sp->GetObjectForDotSeparatedPath("arguments");
        if (!args_sp)
        {
            error.SetErrorString("invalid JSON");
            return error;
        }
        
        auto args_array_sp = args_sp->GetAsArray();
        if (!args_array_sp)
        {
            error.SetErrorString("invalid JSON");
            return error;
        }
        
        launch_info.GetArguments().Clear();
        
        for (size_t i = 0;
             i < args_array_sp->GetSize();
             i++)
        {
            auto item_sp = args_array_sp->GetItemAtIndex(i);
            if (!item_sp)
                continue;
            auto str_sp = item_sp->GetAsString();
            if (!str_sp)
                continue;
            
            launch_info.GetArguments().AppendArgument(str_sp->GetValue().c_str());
        }
    }
    
    return error;
}

static void LLVM_ATTRIBUTE_NORETURN ChildFunc(int error_fd,
                                              const ProcessLaunchInfo &info) {
  if (info.GetFlags().Test(eLaunchFlagLaunchInSeparateProcessGroup)) {
    if (setpgid(0, 0) != 0)
      ExitWithError(error_fd, "setpgid");
  }

  for (size_t i = 0; i < info.GetNumFileActions(); ++i) {
    const FileAction &action = *info.GetFileActionAtIndex(i);
    switch (action.GetAction()) {
    case FileAction::eFileActionClose:
      if (close(action.GetFD()) != 0)
        ExitWithError(error_fd, "close");
      break;
    case FileAction::eFileActionDuplicate:
      if (dup2(action.GetFD(), action.GetActionArgument()) == -1)
        ExitWithError(error_fd, "dup2");
      break;
    case FileAction::eFileActionOpen:
      DupDescriptor(error_fd, action.GetFileSpec(), action.GetFD(),
                    action.GetActionArgument());
      break;
    case FileAction::eFileActionNone:
      break;
    }
  }

  const char **argv = info.GetArguments().GetConstArgumentVector();

  // Change working directory
  if (info.GetWorkingDirectory() &&
      0 != ::chdir(info.GetWorkingDirectory().GetCString()))
    ExitWithError(error_fd, "chdir");

  DisableASLRIfRequested(error_fd, info);
  Environment env = info.GetEnvironment();
  FixupEnvironment(env);
  Environment::Envp envp = env.getEnvp();

  // Clear the signal mask to prevent the child from being affected by any
  // masking done by the parent.
  sigset_t set;
  if (sigemptyset(&set) != 0 ||
      pthread_sigmask(SIG_SETMASK, &set, nullptr) != 0)
    ExitWithError(error_fd, "pthread_sigmask");

  if (info.GetFlags().Test(eLaunchFlagDebug)) {
    // Do not inherit setgid powers.
    if (setgid(getgid()) != 0)
      ExitWithError(error_fd, "setgid");

    // HACK:
    // Close everything besides stdin, stdout, and stderr that has no file
    // action to avoid leaking. Only do this when debugging, as elsewhere we
    // actually rely on passing open descriptors to child processes.
    for (int fd = 3; fd < sysconf(_SC_OPEN_MAX); ++fd)
      if (!info.GetFileActionForFD(fd) && fd != error_fd)
        close(fd);

    // Start tracing this child that is about to exec.
    if (ptrace(PT_TRACE_ME, 0, nullptr, 0) == -1)
      ExitWithError(error_fd, "ptrace");
  }

  // Execute.  We should never return...
  execve(argv[0], const_cast<char *const *>(argv), envp);

#if defined(__linux__)
  if (errno == ETXTBSY) {
    // On android M and earlier we can get this error because the adb daemon
    // can hold a write handle on the executable even after it has finished
    // uploading it. This state lasts only a short time and happens only when
    // there are many concurrent adb commands being issued, such as when
    // running the test suite. (The file remains open when someone does an "adb
    // shell" command in the fork() child before it has had a chance to exec.)
    // Since this state should clear up quickly, wait a while and then give it
    // one more go.
    usleep(50000);
    execve(argv[0], const_cast<char *const *>(argv), envp);
  }
#endif

  // ...unless exec fails.  In which case we definitely need to end the child
  // here.
  ExitWithError(error_fd, "execve");
}

Error
PlatformRemoteGDBServer::LaunchProcess (ProcessLaunchInfo &launch_info)
{
    Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_PLATFORM));
    Error error;

    if (log)
        log->Printf ("PlatformRemoteGDBServer::%s() called", __FUNCTION__);

    auto num_file_actions = launch_info.GetNumFileActions ();
    for (decltype(num_file_actions) i = 0; i < num_file_actions; ++i)
    {
        const auto file_action = launch_info.GetFileActionAtIndex (i);
        if (file_action->GetAction () != FileAction::eFileActionOpen)
            continue;
        switch(file_action->GetFD())
        {
        case STDIN_FILENO:
            m_gdb_client.SetSTDIN(file_action->GetFileSpec());
            break;
        case STDOUT_FILENO:
            m_gdb_client.SetSTDOUT(file_action->GetFileSpec());
            break;
        case STDERR_FILENO:
            m_gdb_client.SetSTDERR(file_action->GetFileSpec());
            break;
        }
    }

    m_gdb_client.SetDisableASLR (launch_info.GetFlags().Test (eLaunchFlagDisableASLR));
    m_gdb_client.SetDetachOnError (launch_info.GetFlags().Test (eLaunchFlagDetachOnError));
    
    FileSpec working_dir = launch_info.GetWorkingDirectory();
    if (working_dir)
    {
        m_gdb_client.SetWorkingDir(working_dir);
    }
    
    // Send the environment and the program + arguments after we connect
    const char **envp = launch_info.GetEnvironmentEntries().GetConstArgumentVector();

    if (envp)
    {
        const char *env_entry;
        for (int i=0; (env_entry = envp[i]); ++i)
        {
            if (m_gdb_client.SendEnvironmentPacket(env_entry) != 0)
                break;
        }
    }
    
    ArchSpec arch_spec = launch_info.GetArchitecture();
    const char *arch_triple = arch_spec.GetTriple().str().c_str();
    
    m_gdb_client.SendLaunchArchPacket(arch_triple);
    if (log)
        log->Printf ("PlatformRemoteGDBServer::%s() set launch architecture triple to '%s'", __FUNCTION__, arch_triple ? arch_triple : "<NULL>");

    int arg_packet_err;
    {
        // Scope for the scoped timeout object
        process_gdb_remote::GDBRemoteCommunication::ScopedTimeout timeout(m_gdb_client, 5);
        arg_packet_err = m_gdb_client.SendArgumentsPacket (launch_info);
    }

    if (arg_packet_err == 0)
    {
        std::string error_str;
        if (m_gdb_client.GetLaunchSuccess (error_str))
        {
            const auto pid = m_gdb_client.GetCurrentProcessID (false);
            if (pid != LLDB_INVALID_PROCESS_ID)
            {
                launch_info.SetProcessID (pid);
                if (log)
                    log->Printf ("PlatformRemoteGDBServer::%s() pid %" PRIu64 " launched successfully", __FUNCTION__, pid);
            }
            else
            {
                if (log)
                    log->Printf ("PlatformRemoteGDBServer::%s() launch succeeded but we didn't get a valid process id back!", __FUNCTION__);
                error.SetErrorString ("failed to get PID");
            }
        }
        else
        {
            error.SetErrorString (error_str.c_str());
            if (log)
                log->Printf ("PlatformRemoteGDBServer::%s() launch failed: %s", __FUNCTION__, error.AsCString ());
        }
    }
    else
    {
        error.SetErrorStringWithFormat("'A' packet returned an error: %i", arg_packet_err);
    }
    return error;
}

// For local debugging, Linux will override the debug logic to use llgs-launch rather than
// lldb-launch, llgs-attach.  This differs from current lldb-launch, debugserver-attach
// approach on MacOSX.
lldb::ProcessSP
PlatformLinux::DebugProcess (ProcessLaunchInfo &launch_info,
                             Debugger &debugger,
                             Target *target,       // Can be NULL, if NULL create a new target, else use existing one
                             Error &error)
{
    Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PLATFORM));
    if (log)
        log->Printf ("PlatformLinux::%s entered (target %p)", __FUNCTION__, static_cast<void*>(target));

    // If we're a remote host, use standard behavior from parent class.
    if (!IsHost ())
        return PlatformPOSIX::DebugProcess (launch_info, debugger, target, error);

    //
    // For local debugging, we'll insist on having ProcessGDBRemote create the process.
    //

    ProcessSP process_sp;

    // Ensure we're using llgs for local debugging.
    if (!UseLlgsForLocalDebugging ())
    {
        assert (false && "we're trying to debug a local process but platform.plugin.linux.use-llgs-for-local is false, should never get here");
        error.SetErrorString ("attempted to start gdb-remote-based debugging for local process but platform.plugin.linux.use-llgs-for-local is false");
        return process_sp;
    }

    // Make sure we stop at the entry point
    launch_info.GetFlags ().Set (eLaunchFlagDebug);

    // We always launch the process we are going to debug in a separate process
    // group, since then we can handle ^C interrupts ourselves w/o having to worry
    // about the target getting them as well.
    launch_info.SetLaunchInSeparateProcessGroup(true);

    // Ensure we have a target.
    if (target == nullptr)
    {
        if (log)
            log->Printf ("PlatformLinux::%s creating new target", __FUNCTION__);

        TargetSP new_target_sp;
        error = debugger.GetTargetList().CreateTarget (debugger,
                                                       nullptr,
                                                       nullptr,
                                                       false,
                                                       nullptr,
                                                       new_target_sp);
        if (error.Fail ())
        {
            if (log)
                log->Printf ("PlatformLinux::%s failed to create new target: %s", __FUNCTION__, error.AsCString ());
            return process_sp;
        }

        target = new_target_sp.get();
        if (!target)
        {
            error.SetErrorString ("CreateTarget() returned nullptr");
            if (log)
                log->Printf ("PlatformLinux::%s failed: %s", __FUNCTION__, error.AsCString ());
            return process_sp;
        }
    }
    else
    {
        if (log)
            log->Printf ("PlatformLinux::%s using provided target", __FUNCTION__);
    }

    // Mark target as currently selected target.
    debugger.GetTargetList().SetSelectedTarget(target);

    // Now create the gdb-remote process.
    if (log)
        log->Printf ("PlatformLinux::%s having target create process with gdb-remote plugin", __FUNCTION__);
    process_sp = target->CreateProcess (launch_info.GetListenerForProcess(debugger), "gdb-remote", nullptr);

    if (!process_sp)
    {
        error.SetErrorString ("CreateProcess() failed for gdb-remote process");
        if (log)
            log->Printf ("PlatformLinux::%s failed: %s", __FUNCTION__, error.AsCString ());
        return process_sp;
    }
    else
    {
        if (log)
            log->Printf ("PlatformLinux::%s successfully created process", __FUNCTION__);
    }

    // Set the unix signals properly.
    process_sp->SetUnixSignals (Host::GetUnixSignals ());

    // Adjust launch for a hijacker.
    ListenerSP listener_sp;
//.........这里部分代码省略.........

Error
Host::LaunchProcess (ProcessLaunchInfo &launch_info)
{
    Error error;
    char exe_path[PATH_MAX];

    PlatformSP host_platform_sp (Platform::GetHostPlatform ());

    const ArchSpec &arch_spec = launch_info.GetArchitecture();

    FileSpec exe_spec(launch_info.GetExecutableFile());

    FileSpec::FileType file_type = exe_spec.GetFileType();
    if (file_type != FileSpec::eFileTypeRegular)
    {
        lldb::ModuleSP exe_module_sp;
        error = host_platform_sp->ResolveExecutable (exe_spec,
                                                     arch_spec,
                                                     exe_module_sp,
                                                     NULL);

        if (error.Fail())
            return error;

        if (exe_module_sp)
            exe_spec = exe_module_sp->GetFileSpec();
    }

    if (exe_spec.Exists())
    {
        exe_spec.GetPath (exe_path, sizeof(exe_path));
    }
    else
    {
        launch_info.GetExecutableFile().GetPath (exe_path, sizeof(exe_path));
        error.SetErrorStringWithFormat ("executable doesn't exist: '%s'", exe_path);
        return error;
    }

    assert(!launch_info.GetFlags().Test (eLaunchFlagLaunchInTTY));

    ::pid_t pid = LLDB_INVALID_PROCESS_ID;

    error = LaunchProcessPosixSpawn(exe_path, launch_info, pid);

    if (pid != LLDB_INVALID_PROCESS_ID)
    {
        // If all went well, then set the process ID into the launch info
        launch_info.SetProcessID(pid);

        Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));

        // Make sure we reap any processes we spawn or we will have zombies.
        if (!launch_info.MonitorProcess())
        {
            const bool monitor_signals = false;
            StartMonitoringChildProcess (Process::SetProcessExitStatus,
                                         NULL,
                                         pid,
                                         monitor_signals);
            if (log)
                log->PutCString ("monitored child process with default Process::SetProcessExitStatus.");
        }
        else
        {
            if (log)
                log->PutCString ("monitored child process with user-specified process monitor.");
        }
    }
    else
    {
        // Invalid process ID, something didn't go well
        if (error.Success())
            error.SetErrorString ("process launch failed for unknown reasons");
    }
    return error;
}

static void LLVM_ATTRIBUTE_NORETURN ChildFunc(int error_fd,
                                              const ProcessLaunchInfo &info) {
  // First, make sure we disable all logging. If we are logging to stdout, our
  // logs can be
  // mistaken for inferior output.
  Log::DisableAllLogChannels(nullptr);

  // Do not inherit setgid powers.
  if (setgid(getgid()) != 0)
    ExitWithError(error_fd, "setgid");

  if (info.GetFlags().Test(eLaunchFlagLaunchInSeparateProcessGroup)) {
    if (setpgid(0, 0) != 0)
      ExitWithError(error_fd, "setpgid");
  }

  for (size_t i = 0; i < info.GetNumFileActions(); ++i) {
    const FileAction &action = *info.GetFileActionAtIndex(i);
    switch (action.GetAction()) {
    case FileAction::eFileActionClose:
      if (close(action.GetFD()) != 0)
        ExitWithError(error_fd, "close");
      break;
    case FileAction::eFileActionDuplicate:
      if (dup2(action.GetFD(), action.GetActionArgument()) == -1)
        ExitWithError(error_fd, "dup2");
      break;
    case FileAction::eFileActionOpen:
      DupDescriptor(error_fd, action.GetFileSpec(), action.GetFD(),
                    action.GetActionArgument());
      break;
    case FileAction::eFileActionNone:
      break;
    }
  }

  const char **argv = info.GetArguments().GetConstArgumentVector();

  // Change working directory
  if (info.GetWorkingDirectory() &&
      0 != ::chdir(info.GetWorkingDirectory().GetCString()))
    ExitWithError(error_fd, "chdir");

  // Disable ASLR if requested.
  if (info.GetFlags().Test(lldb::eLaunchFlagDisableASLR)) {
    const unsigned long personality_get_current = 0xffffffff;
    int value = personality(personality_get_current);
    if (value == -1)
      ExitWithError(error_fd, "personality get");

    value = personality(ADDR_NO_RANDOMIZE | value);
    if (value == -1)
      ExitWithError(error_fd, "personality set");
  }

  Args env = info.GetEnvironmentEntries();
  FixupEnvironment(env);
  const char **envp = env.GetConstArgumentVector();

  // Clear the signal mask to prevent the child from being affected by
  // any masking done by the parent.
  sigset_t set;
  if (sigemptyset(&set) != 0 ||
      pthread_sigmask(SIG_SETMASK, &set, nullptr) != 0)
    ExitWithError(error_fd, "pthread_sigmask");

  if (info.GetFlags().Test(eLaunchFlagDebug)) {
    // HACK:
    // Close everything besides stdin, stdout, and stderr that has no file
    // action to avoid leaking. Only do this when debugging, as elsewhere we
    // actually rely on
    // passing open descriptors to child processes.
    for (int fd = 3; fd < sysconf(_SC_OPEN_MAX); ++fd)
      if (!info.GetFileActionForFD(fd) && fd != error_fd)
        close(fd);

    // Start tracing this child that is about to exec.
    if (ptrace(PTRACE_TRACEME, 0, nullptr, nullptr) == -1)
      ExitWithError(error_fd, "ptrace");
  }

  // Execute.  We should never return...
  execve(argv[0], const_cast<char *const *>(argv),
         const_cast<char *const *>(envp));

  if (errno == ETXTBSY) {
    // On android M and earlier we can get this error because the adb deamon can
    // hold a write
    // handle on the executable even after it has finished uploading it. This
    // state lasts
    // only a short time and happens only when there are many concurrent adb
    // commands being
    // issued, such as when running the test suite. (The file remains open when
    // someone does
    // an "adb shell" command in the fork() child before it has had a chance to
    // exec.) Since
    // this state should clear up quickly, wait a while and then give it one
    // more go.
    usleep(50000);
    execve(argv[0], const_cast<char *const *>(argv),
//.........这里部分代码省略.........

// For local debugging, NetBSD will override the debug logic to use llgs-launch
// rather than lldb-launch, llgs-attach.  This differs from current lldb-
// launch, debugserver-attach approach on MacOSX.
lldb::ProcessSP
PlatformNetBSD::DebugProcess(ProcessLaunchInfo &launch_info, Debugger &debugger,
                             Target *target, // Can be NULL, if NULL create a new
                                             // target, else use existing one
                             Status &error) {
  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PLATFORM));
  LLDB_LOG(log, "target {0}", target);

  // If we're a remote host, use standard behavior from parent class.
  if (!IsHost())
    return PlatformPOSIX::DebugProcess(launch_info, debugger, target, error);

  //
  // For local debugging, we'll insist on having ProcessGDBRemote create the
  // process.
  //

  ProcessSP process_sp;

  // Make sure we stop at the entry point
  launch_info.GetFlags().Set(eLaunchFlagDebug);

  // We always launch the process we are going to debug in a separate process
  // group, since then we can handle ^C interrupts ourselves w/o having to
  // worry about the target getting them as well.
  launch_info.SetLaunchInSeparateProcessGroup(true);

  // Ensure we have a target.
  if (target == nullptr) {
    LLDB_LOG(log, "creating new target");
    TargetSP new_target_sp;
    error = debugger.GetTargetList().CreateTarget(
        debugger, "", "", eLoadDependentsNo, nullptr, new_target_sp);
    if (error.Fail()) {
      LLDB_LOG(log, "failed to create new target: {0}", error);
      return process_sp;
    }

    target = new_target_sp.get();
    if (!target) {
      error.SetErrorString("CreateTarget() returned nullptr");
      LLDB_LOG(log, "error: {0}", error);
      return process_sp;
    }
  }

  // Mark target as currently selected target.
  debugger.GetTargetList().SetSelectedTarget(target);

  // Now create the gdb-remote process.
  LLDB_LOG(log, "having target create process with gdb-remote plugin");
  process_sp =
      target->CreateProcess(launch_info.GetListener(), "gdb-remote", nullptr);

  if (!process_sp) {
    error.SetErrorString("CreateProcess() failed for gdb-remote process");
    LLDB_LOG(log, "error: {0}", error);
    return process_sp;
  }

  LLDB_LOG(log, "successfully created process");
  // Adjust launch for a hijacker.
  ListenerSP listener_sp;
  if (!launch_info.GetHijackListener()) {
    LLDB_LOG(log, "setting up hijacker");
    listener_sp =
        Listener::MakeListener("lldb.PlatformNetBSD.DebugProcess.hijack");
    launch_info.SetHijackListener(listener_sp);
    process_sp->HijackProcessEvents(listener_sp);
  }

  // Log file actions.
  if (log) {
    LLDB_LOG(log, "launching process with the following file actions:");
    StreamString stream;
    size_t i = 0;
    const FileAction *file_action;
    while ((file_action = launch_info.GetFileActionAtIndex(i++)) != nullptr) {
      file_action->Dump(stream);
      LLDB_LOG(log, "{0}", stream.GetData());
      stream.Clear();
    }
  }

  // Do the launch.
  error = process_sp->Launch(launch_info);
  if (error.Success()) {
    // Handle the hijacking of process events.
    if (listener_sp) {
      const StateType state = process_sp->WaitForProcessToStop(
          llvm::None, NULL, false, listener_sp);

      LLDB_LOG(log, "pid {0} state {0}", process_sp->GetID(), state);
    }

    // Hook up process PTY if we have one (which we should for local debugging
    // with llgs).
//.........这里部分代码省略.........