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

#include "lldb/Host/Host.h"

#include <AvailabilityMacros.h>

#if !defined(MAC_OS_X_VERSION_10_7) || MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_7
#define NO_XPC_SERVICES 1 
#endif

#if !defined(NO_XPC_SERVICES)
#define __XPC_PRIVATE_H__
#include <xpc/xpc.h>
#include "launcherXPCService/LauncherXPCService.h"
#endif

#include "llvm/Support/Host.h"

#include <asl.h>
#include <crt_externs.h>
#include <execinfo.h>
#include <grp.h>
#include <libproc.h>
#include <pwd.h>
#include <spawn.h>
#include <stdio.h>
#include <sys/proc.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/types.h>
#include <unistd.h>

#include "lldb/Core/ArchSpec.h"
#include "lldb/Core/Communication.h"
#include "lldb/Core/ConnectionFileDescriptor.h"
#include "lldb/Core/DataExtractor.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/StreamFile.h"
#include "lldb/Core/StreamString.h"
#include "lldb/Host/Endian.h"
#include "lldb/Host/FileSpec.h"
#include "lldb/Target/Platform.h"
#include "lldb/Target/Process.h"
#include "lldb/Utility/CleanUp.h"

#include "cfcpp/CFCBundle.h"
#include "cfcpp/CFCMutableArray.h"
#include "cfcpp/CFCMutableDictionary.h"
#include "cfcpp/CFCReleaser.h"
#include "cfcpp/CFCString.h"


#include <objc/objc-auto.h>

#include <CoreFoundation/CoreFoundation.h>
#include <Foundation/Foundation.h>

#if !defined(__arm__) && !defined(__arm64__)
#include <Carbon/Carbon.h>
#endif

#ifndef _POSIX_SPAWN_DISABLE_ASLR
#define _POSIX_SPAWN_DISABLE_ASLR       0x0100
#endif

extern "C" 
{
    int __pthread_chdir(const char *path);
    int __pthread_fchdir (int fildes);
}

using namespace lldb;
using namespace lldb_private;

static pthread_once_t g_thread_create_once = PTHREAD_ONCE_INIT;
static pthread_key_t g_thread_create_key = 0;

class MacOSXDarwinThread
{
public:
    MacOSXDarwinThread(const char *thread_name) :
        m_pool (nil)
    {
        // Register our thread with the collector if garbage collection is enabled.
        if (objc_collectingEnabled())
        {
#if MAC_OS_X_VERSION_MAX_ALLOWED <= MAC_OS_X_VERSION_10_5
            // On Leopard and earlier there is no way objc_registerThreadWithCollector
            // function, so we do it manually.
            auto_zone_register_thread(auto_zone());
#else
            // On SnowLeopard and later we just call the thread registration function.
            objc_registerThreadWithCollector();
#endif
        }
        else
        {
            m_pool = [[NSAutoreleasePool alloc] init];
        }


        Host::SetThreadName (LLDB_INVALID_PROCESS_ID, LLDB_INVALID_THREAD_ID, thread_name);
    }

    ~MacOSXDarwinThread()
    {
        if (m_pool)
        {
            [m_pool drain];
            m_pool = nil;
        }
    }

    static void PThreadDestructor (void *v)
    {
        if (v)
            delete static_cast<MacOSXDarwinThread*>(v);
        ::pthread_setspecific (g_thread_create_key, NULL);
    }

protected:
    NSAutoreleasePool * m_pool;
private:
    DISALLOW_COPY_AND_ASSIGN (MacOSXDarwinThread);
};

static void
InitThreadCreated()
{
    ::pthread_key_create (&g_thread_create_key, MacOSXDarwinThread::PThreadDestructor);
}

void
Host::ThreadCreated (const char *thread_name)
{
    ::pthread_once (&g_thread_create_once, InitThreadCreated);
    if (g_thread_create_key)
    {
        ::pthread_setspecific (g_thread_create_key, new MacOSXDarwinThread(thread_name));
    }
}

std::string
Host::GetThreadName (lldb::pid_t pid, lldb::tid_t tid)
{
    std::string thread_name;
#if MAC_OS_X_VERSION_MAX_ALLOWED > MAC_OS_X_VERSION_10_5
    // We currently can only get the name of a thread in the current process.
    if (pid == Host::GetCurrentProcessID())
    {
        char pthread_name[1024];
        if (::pthread_getname_np (::pthread_from_mach_thread_np (tid), pthread_name, sizeof(pthread_name)) == 0)
        {
            if (pthread_name[0])
            {
                thread_name = pthread_name;
            }
        }
        else
        {
            dispatch_queue_t current_queue = ::dispatch_get_current_queue ();
            if (current_queue != NULL)
            {
                const char *queue_name = dispatch_queue_get_label (current_queue);
                if (queue_name && queue_name[0])
                {
                    thread_name = queue_name;
                }
            }
        }
    }
#endif
    return thread_name;
}

bool
Host::GetBundleDirectory (const FileSpec &file, FileSpec &bundle_directory)
{
#if defined (__APPLE__)
    if (file.GetFileType () == FileSpec::eFileTypeDirectory)
    {
        char path[PATH_MAX];
        if (file.GetPath(path, sizeof(path)))
        {
            CFCBundle bundle (path);
            if (bundle.GetPath (path, sizeof(path)))
            {
                bundle_directory.SetFile (path, false);
                return true;
            }
        }
    }
#endif
    bundle_directory.Clear();
    return false;
}


bool
Host::ResolveExecutableInBundle (FileSpec &file)
{
#if defined (__APPLE__)
    if (file.GetFileType () == FileSpec::eFileTypeDirectory)
    {
        char path[PATH_MAX];
        if (file.GetPath(path, sizeof(path)))
        {
            CFCBundle bundle (path);
            CFCReleaser<CFURLRef> url(bundle.CopyExecutableURL ());
            if (url.get())
            {
                if (::CFURLGetFileSystemRepresentation (url.get(), YES, (UInt8*)path, sizeof(path)))
                {
                    file.SetFile(path, false);
                    return true;
                }
            }
        }
    }
#endif
  return false;
}

lldb::pid_t
Host::LaunchApplication (const FileSpec &app_file_spec)
{
#if defined (__arm__) || defined(__arm64__)
    return LLDB_INVALID_PROCESS_ID;
#else
    char app_path[PATH_MAX];
    app_file_spec.GetPath(app_path, sizeof(app_path));

    LSApplicationParameters app_params;
    ::memset (&app_params, 0, sizeof (app_params));
    app_params.flags = kLSLaunchDefaults | 
                       kLSLaunchDontAddToRecents | 
                       kLSLaunchNewInstance;
    
    
    FSRef app_fsref;
    CFCString app_cfstr (app_path, kCFStringEncodingUTF8);
    
    OSStatus error = ::FSPathMakeRef ((const UInt8 *)app_path, &app_fsref, NULL);
    
    // If we found the app, then store away the name so we don't have to re-look it up.
    if (error != noErr)
        return LLDB_INVALID_PROCESS_ID;
    
    app_params.application = &app_fsref;

    ProcessSerialNumber psn;

    error = ::LSOpenApplication (&app_params, &psn);

    if (error != noErr)
        return LLDB_INVALID_PROCESS_ID;

    ::pid_t pid = LLDB_INVALID_PROCESS_ID;
    error = ::GetProcessPID(&psn, &pid);
    if (error != noErr)
        return LLDB_INVALID_PROCESS_ID;
    return pid;
#endif
}


static void *
AcceptPIDFromInferior (void *arg)
{
    const char *connect_url = (const char *)arg;
    ConnectionFileDescriptor file_conn;
    Error error;
    if (file_conn.Connect (connect_url, &error) == eConnectionStatusSuccess)
    {
        char pid_str[256];
        ::memset (pid_str, 0, sizeof(pid_str));
        ConnectionStatus status;
        const size_t pid_str_len = file_conn.Read (pid_str, sizeof(pid_str), 0, status, NULL);
        if (pid_str_len > 0)
        {
            int pid = atoi (pid_str);
            return (void *)(intptr_t)pid;
        }
    }
    return NULL;
}

static bool
WaitForProcessToSIGSTOP (const lldb::pid_t pid, const int timeout_in_seconds)
{
    const int time_delta_usecs = 100000;
    const int num_retries = timeout_in_seconds/time_delta_usecs;
    for (int i=0; i<num_retries; i++)
    {
        struct proc_bsdinfo bsd_info;
        int error = ::proc_pidinfo (pid, PROC_PIDTBSDINFO, 
                                    (uint64_t) 0, 
                                    &bsd_info, 
                                    PROC_PIDTBSDINFO_SIZE);
        
        switch (error)
        {
        case EINVAL:
        case ENOTSUP:
        case ESRCH:
        case EPERM:
            return false;
        
        default:
            break;

        case 0:
            if (bsd_info.pbi_status == SSTOP)
                return true;
        }
        ::usleep (time_delta_usecs);
    }
    return false;
}
#if !defined(__arm__) && !defined(__arm64__)

//static lldb::pid_t
//LaunchInNewTerminalWithCommandFile 
//(
//    const char **argv, 
//    const char **envp,
//    const char *working_dir,
//    const ArchSpec *arch_spec,
//    bool stop_at_entry,
//    bool disable_aslr
//)
//{
//    if (!argv || !argv[0])
//        return LLDB_INVALID_PROCESS_ID;
//
//    OSStatus error = 0;
//    
//    FileSpec program (argv[0], false);
//    
//    
//    std::string unix_socket_name;
//
//    char temp_file_path[PATH_MAX];
//    const char *tmpdir = ::getenv ("TMPDIR");
//    if (tmpdir == NULL)
//        tmpdir = "/tmp/";
//    ::snprintf (temp_file_path, sizeof(temp_file_path), "%s%s-XXXXXX", tmpdir, program.GetFilename().AsCString());
//    
//    if (::mktemp (temp_file_path) == NULL)
//        return LLDB_INVALID_PROCESS_ID;
//
//    unix_socket_name.assign (temp_file_path);
//
//    ::strlcat (temp_file_path, ".command", sizeof (temp_file_path));
//
//    StreamFile command_file;
//    command_file.GetFile().Open (temp_file_path, 
//                                 File::eOpenOptionWrite | File::eOpenOptionCanCreate,
//                                 lldb::eFilePermissionsDefault);
//    
//    if (!command_file.GetFile().IsValid())
//        return LLDB_INVALID_PROCESS_ID;
//    
//    FileSpec darwin_debug_file_spec;
//    if (!Host::GetLLDBPath (ePathTypeSupportExecutableDir, darwin_debug_file_spec))
//        return LLDB_INVALID_PROCESS_ID;
//    darwin_debug_file_spec.GetFilename().SetCString("darwin-debug");
//        
//    if (!darwin_debug_file_spec.Exists())
//        return LLDB_INVALID_PROCESS_ID;
//    
//    char launcher_path[PATH_MAX];
//    darwin_debug_file_spec.GetPath(launcher_path, sizeof(launcher_path));
//    command_file.Printf("\"%s\" ", launcher_path);
//    
//    command_file.Printf("--unix-socket=%s ", unix_socket_name.c_str());
//    
//    if (arch_spec && arch_spec->IsValid())
//    {
//        command_file.Printf("--arch=%s ", arch_spec->GetArchitectureName());
//    }
//
//    if (disable_aslr)
//    {
//        command_file.PutCString("--disable-aslr ");
//    }
//        
//    command_file.PutCString("-- ");
//
//    if (argv)
//    {
//        for (size_t i=0; argv[i] != NULL; ++i)
//        {
//            command_file.Printf("\"%s\" ", argv[i]);
//        }
//    }
//    command_file.PutCString("\necho Process exited with status $?\n");
//    command_file.GetFile().Close();
//    if (::chmod (temp_file_path, S_IRWXU | S_IRWXG) != 0)
//        return LLDB_INVALID_PROCESS_ID;
//            
//    CFCMutableDictionary cf_env_dict;
//    
//    const bool can_create = true;
//    if (envp)
//    {
//        for (size_t i=0; envp[i] != NULL; ++i)
//        {
//            const char *env_entry = envp[i];            
//            const char *equal_pos = strchr(env_entry, '=');
//            if (equal_pos)
//            {
//                std::string env_key (env_entry, equal_pos);
//                std::string env_val (equal_pos + 1);
//                CFCString cf_env_key (env_key.c_str(), kCFStringEncodingUTF8);
//                CFCString cf_env_val (env_val.c_str(), kCFStringEncodingUTF8);
//                cf_env_dict.AddValue (cf_env_key.get(), cf_env_val.get(), can_create);
//            }
//        }
//    }
//    
//    LSApplicationParameters app_params;
//    ::memset (&app_params, 0, sizeof (app_params));
//    app_params.flags = kLSLaunchDontAddToRecents | kLSLaunchAsync;
//    app_params.argv = NULL;
//    app_params.environment = (CFDictionaryRef)cf_env_dict.get();
//
//    CFCReleaser<CFURLRef> command_file_url (::CFURLCreateFromFileSystemRepresentation (NULL, 
//                                                                                       (const UInt8 *)temp_file_path, 
//                                                                                       strlen(temp_file_path),
//                                                                                       false));
//    
//    CFCMutableArray urls;
//    
//    // Terminal.app will open the ".command" file we have created
//    // and run our process inside it which will wait at the entry point
//    // for us to attach.
//    urls.AppendValue(command_file_url.get());
//
//
//    lldb::pid_t pid = LLDB_INVALID_PROCESS_ID;
//
//    Error lldb_error;
//    // Sleep and wait a bit for debugserver to start to listen...
//    char connect_url[128];
//    ::snprintf (connect_url, sizeof(connect_url), "unix-accept://%s", unix_socket_name.c_str());
//
//    // Spawn a new thread to accept incoming connection on the connect_url
//    // so we can grab the pid from the inferior
//    lldb::thread_t accept_thread = Host::ThreadCreate (unix_socket_name.c_str(),
//                                                       AcceptPIDFromInferior,
//                                                       connect_url,
//                                                       &lldb_error);
//    
//    ProcessSerialNumber psn;
//    error = LSOpenURLsWithRole(urls.get(), kLSRolesShell, NULL, &app_params, &psn, 1);
//    if (error == noErr)
//    {
//        thread_result_t accept_thread_result = NULL;
//        if (Host::ThreadJoin (accept_thread, &accept_thread_result, &lldb_error))
//        {
//            if (accept_thread_result)
//            {
//                pid = (intptr_t)accept_thread_result;
//            
//                // Wait for process to be stopped the the entry point by watching
//                // for the process status to be set to SSTOP which indicates it it
//                // SIGSTOP'ed at the entry point
//                WaitForProcessToSIGSTOP (pid, 5);
//            }
//        }
//    }
//    else
//    {
//        Host::ThreadCancel (accept_thread, &lldb_error);
//    }
//
//    return pid;
//}

const char *applscript_in_new_tty = 
"tell application \"Terminal\"\n"
"	do script \"%s\"\n"
"end tell\n";


const char *applscript_in_existing_tty = "\
set the_shell_script to \"%s\"\n\
tell application \"Terminal\"\n\
	repeat with the_window in (get windows)\n\
		repeat with the_tab in tabs of the_window\n\
			set the_tty to tty in the_tab\n\
			if the_tty contains \"%s\" then\n\
				if the_tab is not busy then\n\
					set selected of the_tab to true\n\
					set frontmost of the_window to true\n\
					do script the_shell_script in the_tab\n\
					return\n\
				end if\n\
			end if\n\
		end repeat\n\
	end repeat\n\
	do script the_shell_script\n\
end tell\n";


static Error
LaunchInNewTerminalWithAppleScript (const char *exe_path, ProcessLaunchInfo &launch_info)
{
    Error error;
    char unix_socket_name[PATH_MAX] = "/tmp/XXXXXX";    
    if (::mktemp (unix_socket_name) == NULL)
    {
        error.SetErrorString ("failed to make temporary path for a unix socket");
        return error;
    }
    
    StreamString command;
    FileSpec darwin_debug_file_spec;
    if (!Host::GetLLDBPath (ePathTypeSupportExecutableDir, darwin_debug_file_spec))
    {
        error.SetErrorString ("can't locate the 'darwin-debug' executable");
        return error;
    }

    darwin_debug_file_spec.GetFilename().SetCString("darwin-debug");
        
    if (!darwin_debug_file_spec.Exists())
    {
        error.SetErrorStringWithFormat ("the 'darwin-debug' executable doesn't exists at '%s'", 
                                        darwin_debug_file_spec.GetPath().c_str());
        return error;
    }
    
    char launcher_path[PATH_MAX];
    darwin_debug_file_spec.GetPath(launcher_path, sizeof(launcher_path));

    const ArchSpec &arch_spec = launch_info.GetArchitecture();
    if (arch_spec.IsValid())
        command.Printf("arch -arch %s ", arch_spec.GetArchitectureName());

    command.Printf("'%s' --unix-socket=%s", launcher_path, unix_socket_name);

    if (arch_spec.IsValid())
        command.Printf(" --arch=%s", arch_spec.GetArchitectureName());

    const char *working_dir = launch_info.GetWorkingDirectory();
    if (working_dir)
        command.Printf(" --working-dir '%s'", working_dir);
    else
    {
        char cwd[PATH_MAX];
        if (getcwd(cwd, PATH_MAX))
            command.Printf(" --working-dir '%s'", cwd);
    }
    
    if (launch_info.GetFlags().Test (eLaunchFlagDisableASLR))
        command.PutCString(" --disable-aslr");
    
    // We are launching on this host in a terminal. So compare the environemnt on the host
    // to what is supplied in the launch_info. Any items that aren't in the host environemnt
    // need to be sent to darwin-debug. If we send all environment entries, we might blow the
    // max command line length, so we only send user modified entries.
    const char **envp = launch_info.GetEnvironmentEntries().GetConstArgumentVector ();
    StringList host_env;
    const size_t host_env_count = Host::GetEnvironment (host_env);
    const char *env_entry;
    for (size_t env_idx = 0; (env_entry = envp[env_idx]) != NULL; ++env_idx)
    {
        bool add_entry = true;
        for (size_t i=0; i<host_env_count; ++i)
        {
            const char *host_env_entry = host_env.GetStringAtIndex(i);
            if (strcmp(env_entry, host_env_entry) == 0)
            {
                add_entry = false;
                break;
            }
        }
        if (add_entry)
        {
            command.Printf(" --env='%s'", env_entry);
        }
    }

    command.PutCString(" -- ");

    const char **argv = launch_info.GetArguments().GetConstArgumentVector ();
    if (argv)
    {
        for (size_t i=0; argv[i] != NULL; ++i)
        {
            if (i==0)
                command.Printf(" '%s'", exe_path);
            else
                command.Printf(" '%s'", argv[i]);
        }
    }
    else
    {
        command.Printf(" '%s'", exe_path);
    }
    command.PutCString (" ; echo Process exited with status $?");
    
    StreamString applescript_source;

    const char *tty_command = command.GetString().c_str();
//    if (tty_name && tty_name[0])
//    {
//        applescript_source.Printf (applscript_in_existing_tty, 
//                                   tty_command,
//                                   tty_name);
//    }
//    else
//    {
        applescript_source.Printf (applscript_in_new_tty, 
                                   tty_command);
//    }

    

    const char *script_source = applescript_source.GetString().c_str();
    //puts (script_source);
    NSAppleScript* applescript = [[NSAppleScript alloc] initWithSource:[NSString stringWithCString:script_source encoding:NSUTF8StringEncoding]];

    lldb::pid_t pid = LLDB_INVALID_PROCESS_ID;

    Error lldb_error;
    // Sleep and wait a bit for debugserver to start to listen...
    ConnectionFileDescriptor file_conn;
    char connect_url[128];
    ::snprintf (connect_url, sizeof(connect_url), "unix-accept://%s", unix_socket_name);

    // Spawn a new thread to accept incoming connection on the connect_url
    // so we can grab the pid from the inferior. We have to do this because we
    // are sending an AppleScript that will launch a process in Terminal.app,
    // in a shell and the shell will fork/exec a couple of times before we get
    // to the process that we wanted to launch. So when our process actually
    // gets launched, we will handshake with it and get the process ID for it.
    lldb::thread_t accept_thread = Host::ThreadCreate (unix_socket_name,
                                                       AcceptPIDFromInferior,
                                                       connect_url,
                                                       &lldb_error);
    

    [applescript executeAndReturnError:nil];
    
    thread_result_t accept_thread_result = NULL;
    if (Host::ThreadJoin (accept_thread, &accept_thread_result, &lldb_error))
    {
        if (accept_thread_result)
        {
            pid = (intptr_t)accept_thread_result;
        
            // Wait for process to be stopped the the entry point by watching
            // for the process status to be set to SSTOP which indicates it it
            // SIGSTOP'ed at the entry point
            WaitForProcessToSIGSTOP (pid, 5);
        }
    }
    ::unlink (unix_socket_name);
    [applescript release];
    if (pid != LLDB_INVALID_PROCESS_ID)
        launch_info.SetProcessID (pid);
    return error;
}

#endif // #if !defined(__arm__)


// On MacOSX CrashReporter will display a string for each shared library if
// the shared library has an exported symbol named "__crashreporter_info__".

static Mutex&
GetCrashReporterMutex ()
{
    static Mutex g_mutex;
    return g_mutex;
}

extern "C" {
    const char *__crashreporter_info__ = NULL;
}

asm(".desc ___crashreporter_info__, 0x10");

void
Host::SetCrashDescriptionWithFormat (const char *format, ...)
{
    static StreamString g_crash_description;
    Mutex::Locker locker (GetCrashReporterMutex ());
    
    if (format)
    {
        va_list args;
        va_start (args, format);
        g_crash_description.GetString().clear();
        g_crash_description.PrintfVarArg(format, args);
        va_end (args);
        __crashreporter_info__ = g_crash_description.GetData();
    }
    else
    {
        __crashreporter_info__ = NULL;
    }
}

void
Host::SetCrashDescription (const char *cstr)
{
    Mutex::Locker locker (GetCrashReporterMutex ());
    static std::string g_crash_description;
    if (cstr)
    {
        g_crash_description.assign (cstr);
        __crashreporter_info__ = g_crash_description.c_str();
    }
    else
    {
        __crashreporter_info__ = NULL;
    }
}

bool
Host::OpenFileInExternalEditor (const FileSpec &file_spec, uint32_t line_no)
{
#if defined(__arm__) || defined(__arm64__)
    return false;
#else
    // We attach this to an 'odoc' event to specify a particular selection
    typedef struct {
        int16_t   reserved0;  // must be zero
        int16_t   fLineNumber;
        int32_t   fSelStart;
        int32_t   fSelEnd;
        uint32_t  reserved1;  // must be zero
        uint32_t  reserved2;  // must be zero
    } BabelAESelInfo;
    
    Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_HOST));
    char file_path[PATH_MAX];
    file_spec.GetPath(file_path, PATH_MAX);
    CFCString file_cfstr (file_path, kCFStringEncodingUTF8);
    CFCReleaser<CFURLRef> file_URL (::CFURLCreateWithFileSystemPath (NULL, 
                                                                     file_cfstr.get(), 
                                                                     kCFURLPOSIXPathStyle, 
                                                                     false));
                                                                     
    if (log)
        log->Printf("Sending source file: \"%s\" and line: %d to external editor.\n", file_path, line_no);
    
    long error;	
    BabelAESelInfo file_and_line_info = 
    {
        0,                         // reserved0
        (int16_t)(line_no - 1),    // fLineNumber (zero based line number)
        1,                         // fSelStart
        1024,                      // fSelEnd
        0,                         // reserved1
        0                          // reserved2
    };

    AEKeyDesc file_and_line_desc;
    
    error = ::AECreateDesc (typeUTF8Text, 
                            &file_and_line_info, 
                            sizeof (file_and_line_info), 
                            &(file_and_line_desc.descContent));
    
    if (error != noErr)
    {
        if (log)
            log->Printf("Error creating AEDesc: %ld.\n", error);
        return false;
    }
    
    file_and_line_desc.descKey = keyAEPosition;
    
    static std::string g_app_name;
    static FSRef g_app_fsref;

    LSApplicationParameters app_params;
    ::memset (&app_params, 0, sizeof (app_params));
    app_params.flags = kLSLaunchDefaults | 
                       kLSLaunchDontAddToRecents | 
                       kLSLaunchDontSwitch;
    
    char *external_editor = ::getenv ("LLDB_EXTERNAL_EDITOR");
    
    if (external_editor)
    {
        if (log)
            log->Printf("Looking for external editor \"%s\".\n", external_editor);

        if (g_app_name.empty() || strcmp (g_app_name.c_str(), external_editor) != 0)
        {
            CFCString editor_name (external_editor, kCFStringEncodingUTF8);
            error = ::LSFindApplicationForInfo (kLSUnknownCreator, 
                                                NULL, 
                                                editor_name.get(), 
                                                &g_app_fsref, 
                                                NULL);
            
            // If we found the app, then store away the name so we don't have to re-look it up.
            if (error != noErr)
            {
                if (log)
                    log->Printf("Could not find External Editor application, error: %ld.\n", error);
                return false;
            }
                
        }
        app_params.application = &g_app_fsref;
    }

    ProcessSerialNumber psn;
    CFCReleaser<CFArrayRef> file_array(CFArrayCreate (NULL, (const void **) file_URL.ptr_address(false), 1, NULL));
    error = ::LSOpenURLsWithRole (file_array.get(), 
                                  kLSRolesAll, 
                                  &file_and_line_desc, 
                                  &app_params, 
                                  &psn, 
                                  1);
    
    AEDisposeDesc (&(file_and_line_desc.descContent));

    if (error != noErr)
    {
        if (log)
            log->Printf("LSOpenURLsWithRole failed, error: %ld.\n", error);

        return false;
    }
    
    ProcessInfoRec which_process;
    ::memset(&which_process, 0, sizeof(which_process));
    unsigned char ap_name[PATH_MAX];
    which_process.processName = ap_name;
    error = ::GetProcessInformation (&psn, &which_process);
    
    bool using_xcode;
    if (error != noErr)
    {
        if (log)
            log->Printf("GetProcessInformation failed, error: %ld.\n", error);
        using_xcode = false;
    }
    else
        using_xcode = strncmp((char *) ap_name+1, "Xcode", (int) ap_name[0]) == 0;
    
    // Xcode doesn't obey the line number in the Open Apple Event.  So I have to send
    // it an AppleScript to focus on the right line.
    
    if (using_xcode)
    {
        static ComponentInstance osa_component = NULL;
        static const char *as_template = "tell application \"Xcode\"\n"
                                   "set doc to the first document whose path is \"%s\"\n"
                                   "set the selection to paragraph %d of doc\n"
                                   "--- set the selected paragraph range to {%d, %d} of doc\n"
                                   "end tell\n";
        const int chars_for_int = 32;
        static int as_template_len = strlen (as_template);

      
        char *as_str;
        AEDesc as_desc;
      
        if (osa_component == NULL)
        {
            osa_component = ::OpenDefaultComponent (kOSAComponentType,
                                                    kAppleScriptSubtype);
        }
        
        if (osa_component == NULL)
        {
            if (log)
                log->Printf("Could not get default AppleScript component.\n");
            return false;
        }

        uint32_t as_str_size = as_template_len + strlen (file_path) + 3 * chars_for_int + 1;     
        as_str = (char *) malloc (as_str_size);
        ::snprintf (as_str, 
                    as_str_size - 1, 
                    as_template, 
                    file_path, 
                    line_no, 
                    line_no, 
                    line_no);

        error = ::AECreateDesc (typeChar, 
                                as_str, 
                                strlen (as_str),
                                &as_desc);
        
        ::free (as_str);

        if (error != noErr)
        {
            if (log)
                log->Printf("Failed to create AEDesc for Xcode AppleEvent: %ld.\n", error);
            return false;
        }
            
        OSAID ret_OSAID;
        error = ::OSACompileExecute (osa_component, 
                                     &as_desc, 
                                     kOSANullScript, 
                                     kOSAModeNeverInteract, 
                                     &ret_OSAID);
        
        ::OSADispose (osa_component, ret_OSAID);

        ::AEDisposeDesc (&as_desc);

        if (error != noErr)
        {
            if (log)
                log->Printf("Sending AppleEvent to Xcode failed, error: %ld.\n", error);
            return false;
        }
    }
    return true;
#endif // #if !defined(__arm__)
}


void
Host::Backtrace (Stream &strm, uint32_t max_frames)
{
    if (max_frames > 0)
    {
        std::vector<void *> frame_buffer (max_frames, NULL);
        int num_frames = ::backtrace (&frame_buffer[0], frame_buffer.size());
        char** strs = ::backtrace_symbols (&frame_buffer[0], num_frames);
        if (strs)
        {
            // Start at 1 to skip the "Host::Backtrace" frame
            for (int i = 1; i < num_frames; ++i)
                strm.Printf("%s\n", strs[i]);
            ::free (strs);
        }
    }
}

size_t
Host::GetEnvironment (StringList &env)
{
    char **host_env = *_NSGetEnviron();
    char *env_entry;
    size_t i;
    for (i=0; (env_entry = host_env[i]) != NULL; ++i)
        env.AppendString(env_entry);
    return i;
        
}


bool
Host::GetOSBuildString (std::string &s)
{
    int mib[2] = { CTL_KERN, KERN_OSVERSION };
    char cstr[PATH_MAX];
    size_t cstr_len = sizeof(cstr);
    if (::sysctl (mib, 2, cstr, &cstr_len, NULL, 0) == 0)
    {
        s.assign (cstr, cstr_len);
        return true;
    }
    
    s.clear();
    return false;
}

bool
Host::GetOSKernelDescription (std::string &s)
{
    int mib[2] = { CTL_KERN, KERN_VERSION };
    char cstr[PATH_MAX];
    size_t cstr_len = sizeof(cstr);
    if (::sysctl (mib, 2, cstr, &cstr_len, NULL, 0) == 0)
    {
        s.assign (cstr, cstr_len);
        return true;
    }
    s.clear();
    return false;
}

bool
Host::GetOSVersion 
(
    uint32_t &major, 
    uint32_t &minor, 
    uint32_t &update
)
{
    static uint32_t g_major = 0;
    static uint32_t g_minor = 0;
    static uint32_t g_update = 0;

    if (g_major == 0)
    {
        static const char *version_plist_file = "/System/Library/CoreServices/SystemVersion.plist";
        char buffer[256];
        const char *product_version_str = NULL;
        
        CFCReleaser<CFURLRef> plist_url(CFURLCreateFromFileSystemRepresentation(kCFAllocatorDefault,
                                                                                (UInt8 *) version_plist_file,
                                                                                strlen (version_plist_file), NO));
        if (plist_url.get())
        {
            CFCReleaser<CFPropertyListRef> property_list;
            CFCReleaser<CFStringRef>       error_string;
            CFCReleaser<CFDataRef>         resource_data;
            SInt32                         error_code;
     
            // Read the XML file.
            if (CFURLCreateDataAndPropertiesFromResource (kCFAllocatorDefault,
                                                          plist_url.get(),
                                                          resource_data.ptr_address(),
                                                          NULL,
                                                          NULL,
                                                          &error_code))
            {
                   // Reconstitute the dictionary using the XML data.
                property_list = CFPropertyListCreateFromXMLData (kCFAllocatorDefault,
                                                                  resource_data.get(),
                                                                  kCFPropertyListImmutable,
                                                                  error_string.ptr_address());
                if (CFGetTypeID(property_list.get()) == CFDictionaryGetTypeID())
                {
                    CFDictionaryRef property_dict = (CFDictionaryRef) property_list.get();
                    CFStringRef product_version_key = CFSTR("ProductVersion");
                    CFPropertyListRef product_version_value;
                    product_version_value = CFDictionaryGetValue(property_dict, product_version_key);
                    if (product_version_value && CFGetTypeID(product_version_value) == CFStringGetTypeID())
                    {
                        CFStringRef product_version_cfstr = (CFStringRef) product_version_value;
                        product_version_str = CFStringGetCStringPtr(product_version_cfstr, kCFStringEncodingUTF8);
                        if (product_version_str != NULL) {
                            if (CFStringGetCString(product_version_cfstr, buffer, 256, kCFStringEncodingUTF8))
                                product_version_str = buffer;
                        }
                    }
                }
            }
        }
        if (product_version_str)
            Args::StringToVersion(product_version_str, g_major, g_minor, g_update);
    }
    
    if (g_major != 0)
    {
        major = g_major;
        minor = g_minor;
        update = g_update;
        return true;
    }
    return false;
}

static bool
GetMacOSXProcessCPUType (ProcessInstanceInfo &process_info)
{
    if (process_info.ProcessIDIsValid())
    {
        // Make a new mib to stay thread safe
        int mib[CTL_MAXNAME]={0,};
        size_t mib_len = CTL_MAXNAME;
        if (::sysctlnametomib("sysctl.proc_cputype", mib, &mib_len)) 
            return false;
    
        mib[mib_len] = process_info.GetProcessID();
        mib_len++;

        cpu_type_t cpu, sub = 0;
        size_t len = sizeof(cpu);
        if (::sysctl (mib, mib_len, &cpu, &len, 0, 0) == 0)
        {
            switch (cpu)
            {
                case CPU_TYPE_I386:      sub = CPU_SUBTYPE_I386_ALL;     break;
                case CPU_TYPE_X86_64:    sub = CPU_SUBTYPE_X86_64_ALL;   break;

#if defined (CPU_TYPE_ARM64) && defined (CPU_SUBTYPE_ARM64_ALL)
                case CPU_TYPE_ARM64:     sub = CPU_SUBTYPE_ARM64_ALL;      break;
#endif

                case CPU_TYPE_ARM:
                    {
                        // Note that we fetched the cpu type from the PROCESS but we can't get a cpusubtype of the 
                        // process -- we can only get the host's cpu subtype.
                        uint32_t cpusubtype = 0;
                        len = sizeof(cpusubtype);
                        if (::sysctlbyname("hw.cpusubtype", &cpusubtype, &len, NULL, 0) == 0)
                            sub = cpusubtype;

                        bool host_cpu_is_64bit;
                        uint32_t is64bit_capable;
                        size_t is64bit_capable_len = sizeof (is64bit_capable);
                        if (sysctlbyname("hw.cpu64bit_capable", &is64bit_capable, &is64bit_capable_len, NULL, 0) == 0)
                            host_cpu_is_64bit = true;
                        else
                            host_cpu_is_64bit = false;

                        // if the host is an armv8 device, its cpusubtype will be in CPU_SUBTYPE_ARM64 numbering
                        // and we need to rewrite it to a reasonable CPU_SUBTYPE_ARM value instead.

                        if (host_cpu_is_64bit)
                        {
                            sub = CPU_SUBTYPE_ARM_V7;
                        }
                    }
                    break;

                default:
                    break;
            }
            process_info.GetArchitecture ().SetArchitecture (eArchTypeMachO, cpu, sub);
            return true;
        }
    }
    process_info.GetArchitecture().Clear();
    return false;
}

static bool
GetMacOSXProcessArgs (const ProcessInstanceInfoMatch *match_info_ptr,
                      ProcessInstanceInfo &process_info)
{
    if (process_info.ProcessIDIsValid())
    {
        int proc_args_mib[3] = { CTL_KERN, KERN_PROCARGS2, (int)process_info.GetProcessID() };

        char arg_data[8192];
        size_t arg_data_size = sizeof(arg_data);
        if (::sysctl (proc_args_mib, 3, arg_data, &arg_data_size , NULL, 0) == 0)
        {
            DataExtractor data (arg_data, arg_data_size, lldb::endian::InlHostByteOrder(), sizeof(void *));
            lldb::offset_t offset = 0;
            uint32_t argc = data.GetU32 (&offset);
            const char *cstr;
            
            cstr = data.GetCStr (&offset);
            if (cstr)
            {
                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()))
                {
                    // Skip NULLs
                    while (1)
                    {
                        const uint8_t *p = data.PeekData(offset, 1);
                        if ((p == NULL) || (*p != '\0'))
                            break;
                        ++offset;
                    }
                    // Now extract all arguments
                    Args &proc_args = process_info.GetArguments();
                    for (int i=0; i<static_cast<int>(argc); ++i)
                    {
                        cstr = data.GetCStr(&offset);
                        if (cstr)
                            proc_args.AppendArgument(cstr);
                    }
                    return true;
                }
            }
        }
    }
    return false;
}

static bool
GetMacOSXProcessUserAndGroup (ProcessInstanceInfo &process_info)
{
    if (process_info.ProcessIDIsValid())
    {
        int mib[4];
        mib[0] = CTL_KERN;
        mib[1] = KERN_PROC;
        mib[2] = KERN_PROC_PID;
        mib[3] = process_info.GetProcessID();
        struct kinfo_proc proc_kinfo;
        size_t proc_kinfo_size = sizeof(struct kinfo_proc);

        if (::sysctl (mib, 4, &proc_kinfo, &proc_kinfo_size, NULL, 0) == 0)
        {
            if (proc_kinfo_size > 0)
            {
                process_info.SetParentProcessID (proc_kinfo.kp_eproc.e_ppid);
                process_info.SetUserID (proc_kinfo.kp_eproc.e_pcred.p_ruid);
                process_info.SetGroupID (proc_kinfo.kp_eproc.e_pcred.p_rgid);
                process_info.SetEffectiveUserID (proc_kinfo.kp_eproc.e_ucred.cr_uid);
                if (proc_kinfo.kp_eproc.e_ucred.cr_ngroups > 0)
                    process_info.SetEffectiveGroupID (proc_kinfo.kp_eproc.e_ucred.cr_groups[0]);
                else
                    process_info.SetEffectiveGroupID (UINT32_MAX);            
                return true;
            }
        }
    }
    process_info.SetParentProcessID (LLDB_INVALID_PROCESS_ID);
    process_info.SetUserID (UINT32_MAX);
    process_info.SetGroupID (UINT32_MAX);
    process_info.SetEffectiveUserID (UINT32_MAX);
    process_info.SetEffectiveGroupID (UINT32_MAX);            
    return false;
}


uint32_t
Host::FindProcesses (const ProcessInstanceInfoMatch &match_info, ProcessInstanceInfoList &process_infos)
{
    std::vector<struct kinfo_proc> kinfos;
    
    int mib[3] = { CTL_KERN, KERN_PROC, KERN_PROC_ALL };
    
    size_t pid_data_size = 0;
    if (::sysctl (mib, 4, NULL, &pid_data_size, NULL, 0) != 0)
        return 0;
    
    // Add a few extra in case a few more show up
    const size_t estimated_pid_count = (pid_data_size / sizeof(struct kinfo_proc)) + 10;

    kinfos.resize (estimated_pid_count);
    pid_data_size = kinfos.size() * sizeof(struct kinfo_proc);
    
    if (::sysctl (mib, 4, &kinfos[0], &pid_data_size, NULL, 0) != 0)
        return 0;

    const size_t actual_pid_count = (pid_data_size / sizeof(struct kinfo_proc));

    bool all_users = match_info.GetMatchAllUsers();
    const lldb::pid_t our_pid = getpid();
    const uid_t our_uid = getuid();
    for (size_t i = 0; i < actual_pid_count; i++)
    {
        const struct kinfo_proc &kinfo = kinfos[i];
        
        bool kinfo_user_matches = false;
        if (all_users)
            kinfo_user_matches = true;
        else
            kinfo_user_matches = kinfo.kp_eproc.e_pcred.p_ruid == our_uid;

        // Special case, if lldb is being run as root we can attach to anything.
        if (our_uid == 0)
          kinfo_user_matches = true;

        if (kinfo_user_matches == false         || // Make sure the user is acceptable
            static_cast<lldb::pid_t>(kinfo.kp_proc.p_pid) == our_pid || // Skip this process
            kinfo.kp_proc.p_pid == 0            || // Skip kernel (kernel pid is zero)
            kinfo.kp_proc.p_stat == SZOMB       || // Zombies are bad, they like brains...
            kinfo.kp_proc.p_flag & P_TRACED     || // Being debugged?
            kinfo.kp_proc.p_flag & P_WEXIT      || // Working on exiting?
            kinfo.kp_proc.p_flag & P_TRANSLATED)   // Skip translated ppc (Rosetta)
            continue;

        ProcessInstanceInfo process_info;
        process_info.SetProcessID (kinfo.kp_proc.p_pid);
        process_info.SetParentProcessID (kinfo.kp_eproc.e_ppid);
        process_info.SetUserID (kinfo.kp_eproc.e_pcred.p_ruid);
        process_info.SetGroupID (kinfo.kp_eproc.e_pcred.p_rgid);
        process_info.SetEffectiveUserID (kinfo.kp_eproc.e_ucred.cr_uid);
        if (kinfo.kp_eproc.e_ucred.cr_ngroups > 0)
            process_info.SetEffectiveGroupID (kinfo.kp_eproc.e_ucred.cr_groups[0]);
        else
            process_info.SetEffectiveGroupID (UINT32_MAX);            

        // Make sure our info matches before we go fetch the name and cpu type
        if (match_info.Matches (process_info))
        {
            if (GetMacOSXProcessArgs (&match_info, process_info))
            {
                GetMacOSXProcessCPUType (process_info);
                if (match_info.Matches (process_info))
                    process_infos.Append (process_info);
            }
        }
    }    
    return process_infos.GetSize();
}

bool
Host::GetProcessInfo (lldb::pid_t pid, ProcessInstanceInfo &process_info)
{
    process_info.SetProcessID(pid);
    bool success = false;
    
    if (GetMacOSXProcessArgs (NULL, process_info))
        success = true;
    
    if (GetMacOSXProcessCPUType (process_info))
        success = true;
    
    if (GetMacOSXProcessUserAndGroup (process_info))
        success = true;
    
    if (success)
        return true;
    
    process_info.Clear();
    return false;
}

#if !NO_XPC_SERVICES
static void
PackageXPCArguments (xpc_object_t message, const char *prefix, const Args& args)
{
    size_t count = args.GetArgumentCount();
    char buf[50]; // long enough for 'argXXX'
    memset(buf, 0, 50);
    sprintf(buf, "%sCount", prefix);
	xpc_dictionary_set_int64(message, buf, count);
    for (size_t i=0; i<count; i++) {
        memset(buf, 0, 50);
        sprintf(buf, "%s%zi", prefix, i);
        xpc_dictionary_set_string(message, buf, args.GetArgumentAtIndex(i));
    }
}

/*
 A valid authorizationRef means that 
    - there is the LaunchUsingXPCRightName rights in the /etc/authorization
    - we have successfully copied the rights to be send over the XPC wire
 Once obtained, it will be valid for as long as the process lives.
 */
static AuthorizationRef authorizationRef = NULL;
static Error
getXPCAuthorization (ProcessLaunchInfo &launch_info)
{
    Error error;
    Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_HOST | LIBLLDB_LOG_PROCESS));
    
    if ((launch_info.GetUserID() == 0) && !authorizationRef)
    {
        OSStatus createStatus = AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment, kAuthorizationFlagDefaults, &authorizationRef);
        if (createStatus != errAuthorizationSuccess)
        {
            error.SetError(1, eErrorTypeGeneric);
            error.SetErrorString("Can't create authorizationRef.");
            if (log)
            {
                error.PutToLog(log, "%s", error.AsCString());
            }
            return error;
        }
        
        OSStatus rightsStatus = AuthorizationRightGet(LaunchUsingXPCRightName, NULL);
        if (rightsStatus != errAuthorizationSuccess)
        {
            // No rights in the security database, Create it with the right prompt.
            CFStringRef prompt = CFSTR("Xcode is trying to take control of a root process.");
            CFStringRef keys[] = { CFSTR("en") };
            CFTypeRef values[] = { prompt };
            CFDictionaryRef promptDict = CFDictionaryCreate(kCFAllocatorDefault, (const void **)keys, (const void **)values, 1, &kCFCopyStringDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
            
            CFStringRef keys1[] = { CFSTR("class"), CFSTR("group"), CFSTR("comment"),               CFSTR("default-prompt"), CFSTR("shared") };
            CFTypeRef values1[] = { CFSTR("user"),  CFSTR("admin"), CFSTR(LaunchUsingXPCRightName), promptDict,              kCFBooleanFalse };
            CFDictionaryRef dict = CFDictionaryCreate(kCFAllocatorDefault, (const void **)keys1, (const void **)values1, 5, &kCFCopyStringDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
            rightsStatus = AuthorizationRightSet(authorizationRef, LaunchUsingXPCRightName, dict, NULL, NULL, NULL);
            CFRelease(promptDict);
            CFRelease(dict);
        }
            
        OSStatus copyRightStatus = errAuthorizationDenied;
        if (rightsStatus == errAuthorizationSuccess)
        {
            AuthorizationItem item1 = { LaunchUsingXPCRightName, 0, NULL, 0 };
            AuthorizationItem items[] = {item1};
            AuthorizationRights requestedRights = {1, items };
            AuthorizationFlags authorizationFlags = kAuthorizationFlagInteractionAllowed | kAuthorizationFlagExtendRights;
            copyRightStatus = AuthorizationCopyRights(authorizationRef, &requestedRights, kAuthorizationEmptyEnvironment, authorizationFlags, NULL);
        }
        
        if (copyRightStatus != errAuthorizationSuccess)
        {
            // Eventually when the commandline supports running as root and the user is not
            // logged in in the current audit session, we will need the trick in gdb where
            // we ask the user to type in the root passwd in the terminal.
            error.SetError(2, eErrorTypeGeneric);
            error.SetErrorStringWithFormat("Launching as root needs root authorization.");
            if (log)
            {
                error.PutToLog(log, "%s", error.AsCString());
            }
            
            if (authorizationRef)
            {
                AuthorizationFree(authorizationRef, kAuthorizationFlagDefaults);
                authorizationRef = NULL;
            }
        }
    }

    return error;
}
#endif

static Error
LaunchProcessXPC (const char *exe_path, ProcessLaunchInfo &launch_info, ::pid_t &pid)
{
#if !NO_XPC_SERVICES
    Error error = getXPCAuthorization(launch_info);
    if (error.Fail())
        return error;
    
    Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_HOST | LIBLLDB_LOG_PROCESS));
    
    uid_t requested_uid = launch_info.GetUserID();
    const char *xpc_service  = nil;
    bool send_auth = false;
    AuthorizationExternalForm extForm;
    if ((requested_uid == UINT32_MAX) || (requested_uid == Host::GetEffectiveUserID()))
    {
        xpc_service = "com.apple.lldb.launcherXPCService";
    }
    else if (requested_uid == 0)
    {
        if (AuthorizationMakeExternalForm(authorizationRef, &extForm) == errAuthorizationSuccess)
        {
            send_auth = true;
        }
        else
        {
            error.SetError(3, eErrorTypeGeneric);
            error.SetErrorStringWithFormat("Launching root via XPC needs to externalize authorization reference.");
            if (log)
            {
                error.PutToLog(log, "%s", error.AsCString());
            }
            return error;
        }
        xpc_service = "com.apple.lldb.launcherRootXPCService";
    }
    else
    {
        error.SetError(4, eErrorTypeGeneric);
        error.SetErrorStringWithFormat("Launching via XPC is only currently available for either the login user or root.");
        if (log)
        {
            error.PutToLog(log, "%s", error.AsCString());
        }
        return error;
    }
    
    xpc_connection_t conn = xpc_connection_create(xpc_service, NULL);
    
	xpc_connection_set_event_handler(conn, ^(xpc_object_t event) {
        xpc_type_t	type = xpc_get_type(event);
        
        if (type == XPC_TYPE_ERROR) {
            if (event == XPC_ERROR_CONNECTION_INTERRUPTED) {
                // The service has either canceled itself, crashed, or been terminated.
                // The XPC connection is still valid and sending a message to it will re-launch the service.
                // If the service is state-full, this is the time to initialize the new service.
                return;
            } else if (event == XPC_ERROR_CONNECTION_INVALID) {
                // The service is invalid. Either the service name supplied to xpc_connection_create() is incorrect
                // or we (this process) have canceled the service; we can do any cleanup of appliation state at this point.
                // printf("Service disconnected");
                return;
            } else {
                // printf("Unexpected error from service: %s", xpc_dictionary_get_string(event, XPC_ERROR_KEY_DESCRIPTION));
            }
            
        } else {
            // printf("Received unexpected event in handler");
        }
    });
    
    xpc_connection_set_finalizer_f (conn, xpc_finalizer_t(xpc_release));
	xpc_connection_resume (conn);
    xpc_object_t message = xpc_dictionary_create (nil, nil, 0);
    
    if (send_auth)
    {
        xpc_dictionary_set_data(message, LauncherXPCServiceAuthKey, extForm.bytes, sizeof(AuthorizationExternalForm));
    }
    
    PackageXPCArguments(message, LauncherXPCServiceArgPrefxKey, launch_info.GetArguments());
    PackageXPCArguments(message, LauncherXPCServiceEnvPrefxKey, launch_info.GetEnvironmentEntries());
    
    // Posix spawn stuff.
    xpc_dictionary_set_int64(message, LauncherXPCServiceCPUTypeKey, launch_info.GetArchitecture().GetMachOCPUType());
    xpc_dictionary_set_int64(message, LauncherXPCServicePosixspawnFlagsKey, Host::GetPosixspawnFlags(launch_info));
    const ProcessLaunchInfo::FileAction *file_action = launch_info.GetFileActionForFD(STDIN_FILENO);
    if (file_action && file_action->GetPath())
    {
        xpc_dictionary_set_string(message, LauncherXPCServiceStdInPathKeyKey, file_action->GetPath());
    }
    file_action = launch_info.GetFileActionForFD(STDOUT_FILENO);
    if (file_action && file_action->GetPath())
    {
        xpc_dictionary_set_string(message, LauncherXPCServiceStdOutPathKeyKey, file_action->GetPath());
    }
    file_action = launch_info.GetFileActionForFD(STDERR_FILENO);
    if (file_action && file_action->GetPath())
    {
        xpc_dictionary_set_string(message, LauncherXPCServiceStdErrPathKeyKey, file_action->GetPath());
    }
    
    xpc_object_t reply = xpc_connection_send_message_with_reply_sync(conn, message);
    xpc_type_t returnType = xpc_get_type(reply);
    if (returnType == XPC_TYPE_DICTIONARY)
    {
        pid = xpc_dictionary_get_int64(reply, LauncherXPCServiceChildPIDKey);
        if (pid == 0)
        {
            int errorType = xpc_dictionary_get_int64(reply, LauncherXPCServiceErrorTypeKey);
            int errorCode = xpc_dictionary_get_int64(reply, LauncherXPCServiceCodeTypeKey);
            
            error.SetError(errorCode, eErrorTypeGeneric);
            error.SetErrorStringWithFormat("Problems with launching via XPC. Error type : %i, code : %i", errorType, errorCode);
            if (log)
            {
                error.PutToLog(log, "%s", error.AsCString());
            }
            
            if (authorizationRef)
            {
                AuthorizationFree(authorizationRef, kAuthorizationFlagDefaults);
                authorizationRef = NULL;
            }
        }
    }
    else if (returnType == XPC_TYPE_ERROR)
    {
        error.SetError(5, eErrorTypeGeneric);
        error.SetErrorStringWithFormat("Problems with launching via XPC. XPC error : %s", xpc_dictionary_get_string(reply, XPC_ERROR_KEY_DESCRIPTION));
        if (log)
        {
            error.PutToLog(log, "%s", error.AsCString());
        }
    }
    
    return error;
#else
    Error error;
    return error;
#endif
}

static bool
ShouldLaunchUsingXPC(ProcessLaunchInfo &launch_info)
{
    bool result = false;

#if !NO_XPC_SERVICES    
    bool launchingAsRoot = launch_info.GetUserID() == 0;
    bool currentUserIsRoot = Host::GetEffectiveUserID() == 0;
    
    if (launchingAsRoot && !currentUserIsRoot)
    {
        // If current user is already root, we don't need XPC's help.
        result = true;
    }
#endif
    
    return result;
}

Error
Host::LaunchProcess (ProcessLaunchInfo &launch_info)
{
    Error error;
    char exe_path[PATH_MAX];
    PlatformSP host_platform_sp (Platform::GetDefaultPlatform ());
    
    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;
    }
    
    if (launch_info.GetFlags().Test (eLaunchFlagLaunchInTTY))
    {
#if !defined(__arm__) && !defined(__arm64__)
        return LaunchInNewTerminalWithAppleScript (exe_path, launch_info);
#else
        error.SetErrorString ("launching a processs in a new terminal is not supported on iOS devices");
        return error;
#endif
    }
    
    ::pid_t pid = LLDB_INVALID_PROCESS_ID;
    
    if (ShouldLaunchUsingXPC(launch_info))
    {
        error = LaunchProcessXPC(exe_path, launch_info, pid);
    }
    else
    {
        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);
        
        // 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);
        }
    }
    else
    {
        // Invalid process ID, something didn't go well
        if (error.Success())
            error.SetErrorString ("process launch failed for unknown reasons");
    }
    return error;
}

lldb::thread_t
Host::StartMonitoringChildProcess (Host::MonitorChildProcessCallback callback,
                                   void *callback_baton,
                                   lldb::pid_t pid,
                                   bool monitor_signals)
{
    lldb::thread_t thread = LLDB_INVALID_HOST_THREAD;
    unsigned long mask = DISPATCH_PROC_EXIT;
    if (monitor_signals)
        mask |= DISPATCH_PROC_SIGNAL;

    Log *log(lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_HOST | LIBLLDB_LOG_PROCESS));


    dispatch_source_t source = ::dispatch_source_create (DISPATCH_SOURCE_TYPE_PROC, 
                                                         pid, 
                                                         mask, 
                                                         ::dispatch_get_global_queue (DISPATCH_QUEUE_PRIORITY_DEFAULT,0));

    if (log)
        log->Printf ("Host::StartMonitoringChildProcess (callback=%p, baton=%p, pid=%i, monitor_signals=%i) source = %p\n", 
                     callback, 
                     callback_baton, 
                     (int)pid, 
                     monitor_signals, 
                     source);

    if (source)
    {
        ::dispatch_source_set_cancel_handler (source, ^{
            ::dispatch_release (source);
        });
        ::dispatch_source_set_event_handler (source, ^{
            
            int status= 0;
            int wait_pid = 0;
            bool cancel = false;
            bool exited = false;
            do
            {
                wait_pid = ::waitpid (pid, &status, 0);
            } while (wait_pid < 0 && errno == EINTR);

            if (wait_pid >= 0)
            {
                int signal = 0;
                int exit_status = 0;
                const char *status_cstr = NULL;
                if (WIFSTOPPED(status))
                {
                    signal = WSTOPSIG(status);
                    status_cstr = "STOPPED";
                }
                else if (WIFEXITED(status))
                {
                    exit_status = WEXITSTATUS(status);
                    status_cstr = "EXITED";
                    exited = true;
                }
                else if (WIFSIGNALED(status))
                {
                    signal = WTERMSIG(status);
                    status_cstr = "SIGNALED";
                    exited = true;
                    exit_status = -1;
                }
                else
                {
                    status_cstr = "???";
                }

                if (log)
                    log->Printf ("::waitpid (pid = %llu, &status, 0) => pid = %i, status = 0x%8.8x (%s), signal = %i, exit_status = %i",
                                 pid,
                                 wait_pid,
                                 status,
                                 status_cstr,
                                 signal,
                                 exit_status);
                
                if (callback)
                    cancel = callback (callback_baton, pid, exited, signal, exit_status);
                
                if (exited || cancel)
                {
                    ::dispatch_source_cancel(source);
                }
            }
        });

        ::dispatch_resume (source);
    }
    return thread;
}

//----------------------------------------------------------------------
// Log to both stderr and to ASL Logging when running on MacOSX.
//----------------------------------------------------------------------
void
Host::SystemLog (SystemLogType type, const char *format, va_list args)
{
    if (format && format[0])
    {
        static aslmsg g_aslmsg = NULL;
        if (g_aslmsg == NULL)
        {
            g_aslmsg = ::asl_new (ASL_TYPE_MSG);
            char asl_key_sender[PATH_MAX];
            snprintf(asl_key_sender, sizeof(asl_key_sender), "com.apple.LLDB.framework");
            ::asl_set (g_aslmsg, ASL_KEY_SENDER, asl_key_sender);
        }
        
        // Copy the va_list so we can log this message twice
        va_list copy_args;
        va_copy (copy_args, args);
        // Log to stderr
        ::vfprintf (stderr, format, copy_args);
        va_end (copy_args);

        int asl_level;
        switch (type)
        {
            case eSystemLogError:
                asl_level = ASL_LEVEL_ERR;
                break;
                
            case eSystemLogWarning:
                asl_level = ASL_LEVEL_WARNING;
                break;
        }
        
        // Log to ASL
        ::asl_vlog (NULL, g_aslmsg, asl_level, format, args);
    }
}

lldb::DataBufferSP
Host::GetAuxvData(lldb_private::Process *process)
{
    return lldb::DataBufferSP();
}