<rdar://problem/3535148>

Added ability to debug root processes on OS X. This uses XPC service that is available on Lion and above only.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@151419 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Host/common/Host.cpp b/source/Host/common/Host.cpp
index 5f0362b..e9fdf46 100644
--- a/source/Host/common/Host.cpp
+++ b/source/Host/common/Host.cpp
@@ -1173,7 +1173,31 @@
 }
 #endif
 
-#if !defined(__APPLE__)
+uint32_t
+Host::GetUserID ()
+{
+    return getuid();
+}
+
+uint32_t
+Host::GetGroupID ()
+{
+    return getgid();
+}
+
+uint32_t
+Host::GetEffectiveUserID ()
+{
+    return geteuid();
+}
+
+uint32_t
+Host::GetEffectiveGroupID ()
+{
+    return getegid();
+}
+
+#if !defined (__APPLE__)
 uint32_t
 Host::FindProcesses (const ProcessInstanceInfoMatch &match_info, ProcessInstanceInfoList &process_infos)
 {
diff --git a/source/Host/macosx/Host.mm b/source/Host/macosx/Host.mm
index 9547565..944f05a 100644
--- a/source/Host/macosx/Host.mm
+++ b/source/Host/macosx/Host.mm
@@ -9,6 +9,17 @@
 
 #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 BUILDING_ON_SNOW_LEOPARD 1
+#endif
+
+#if !BUILDING_ON_SNOW_LEOPARD
+#include <xpc/xpc.h>
+#include "LauncherXPCService.h"
+#endif
+
 #include <asl.h>
 #include <crt_externs.h>
 #include <execinfo.h>
@@ -53,8 +64,8 @@
 #else
 #include <ApplicationServices/ApplicationServices.h>
 #include <Carbon/Carbon.h>
+#include <Security/Security.h>
 #endif
-#include <Foundation/Foundation.h>
 
 #ifndef _POSIX_SPAWN_DISABLE_ASLR
 #define _POSIX_SPAWN_DISABLE_ASLR       0x0100
@@ -1219,57 +1230,216 @@
     return false;
 }
 
-Error
-Host::LaunchProcess (ProcessLaunchInfo &launch_info)
+static short
+GetPosixspawnFlags (ProcessLaunchInfo &launch_info)
+{
+    short flags = POSIX_SPAWN_SETSIGDEF | POSIX_SPAWN_SETSIGMASK;
+    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
+    
+    //#ifdef POSIX_SPAWN_CLOEXEC_DEFAULT
+    //    // Close all files exception those with file actions if this is supported.
+    //    flags |= POSIX_SPAWN_CLOEXEC_DEFAULT;       
+    //#endif
+    
+    return flags;
+}
+
+#if !BUILDING_ON_SNOW_LEOPARD
+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 (int i=0; i<count; i++) {
+        memset(buf, 0, 50);
+        sprintf(buf, "%s%i", prefix, i);
+        xpc_dictionary_set_string(message, buf, args.GetArgumentAtIndex(i));
+    }
+}
+
+static Error
+getXPCAuthorization (ProcessLaunchInfo &launch_info)
 {
     Error error;
     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_HOST | LIBLLDB_LOG_PROCESS));
-    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)
+    if (launch_info.GetUserID() == 0)
     {
-        lldb::ModuleSP exe_module_sp;
-        error = host_platform_sp->ResolveExecutable (exe_spec,
-                                                     arch_spec,
-                                                     exe_module_sp,
-                                                     NULL);
-    
-        if (error.Fail())
+        CFDictionaryRef dict = NULL;
+        OSStatus osStatus;
+        const char *rightName = "com.apple.lldb.LaunchUsingXPC";
+
+        osStatus = AuthorizationRightGet(rightName, &dict);
+        if (dict) CFRelease(dict);
+        if (osStatus == errAuthorizationSuccess)
+        {
+            // Got the right already.
             return error;
-    
-        if (exe_module_sp)
-            exe_spec = exe_module_sp->GetFileSpec();
+        }
+        
+        AuthorizationFlags authorizationFlags = kAuthorizationFlagDefaults;
+        AuthorizationRef authorizationRef = NULL;
+        osStatus = AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment, authorizationFlags, &authorizationRef);
+        if (osStatus != errAuthorizationSuccess)
+        {
+            error.SetError(1, eErrorTypeGeneric);
+            if (log)
+            {
+                error.PutToLog(log.get(), "Can't create authorizationRef.");
+            }
+            else {
+                error.SetErrorString("Can't create authorizationRef.");
+            }
+            return error;
+        }
+        
+        CFStringRef prompt = CFSTR("The debugger is debugging a root process. Please authenticate as an administrator.");
+//        CFStringRef keys[] = { CFSTR("") };
+//        CFTypeRef values[] = { prompt };
+//        CFDictionaryRef promptDict = CFDictionaryCreate( kCFAllocatorDefault, (const void **)keys, (const void **)values, 1, &kCFCopyStringDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
+        
+        int timeout = 1; // Make this 10
+        CFNumberRef timeoutRef = CFNumberCreate(NULL, kCFNumberIntType, &timeout);
+        CFStringRef keys1[] = { CFSTR("class"), CFSTR("group"), CFSTR("comment"),                       CFSTR("shared"), CFSTR("timeout") };
+        CFTypeRef values1[] = { CFSTR("user"),  CFSTR("admin"), CFSTR("com.apple.lldb.LaunchUsingXPC"), kCFBooleanFalse, timeoutRef};
+        dict = CFDictionaryCreate( kCFAllocatorDefault, (const void **)keys1, (const void **)values1, 5, &kCFCopyStringDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
+        
+        osStatus = AuthorizationRightSet(authorizationRef, rightName, dict, prompt, NULL, NULL);
+        if (osStatus != 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);
+            if (log)
+            {
+                error.PutToLog(log.get(), "Launching as root needs root authorization.");
+            }
+            else
+            {
+                error.SetErrorStringWithFormat("Launching as root needs root authorization.");
+            }
+        }
+        CFRelease(timeoutRef);
+//        CFRelease(promptDict);
+        CFRelease(dict);
+        if (authorizationRef) {
+            AuthorizationFree(authorizationRef, kAuthorizationFlagDestroyRights);
+        }
     }
+
+    return error;
+}
+#endif
+
+static Error
+LaunchProcessXPC (const char *exe_path, ProcessLaunchInfo &launch_info, ::pid_t &pid)
+{
+#if !BUILDING_ON_SNOW_LEOPARD
+    Error error = getXPCAuthorization(launch_info);
+    if (error.Fail())
+        return error;
     
-    if (exe_spec.Exists())
+    LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_HOST | LIBLLDB_LOG_PROCESS));
+        
+    uid_t requested_uid = launch_info.GetUserID();
+    const char *xpc_service  = nil;
+    if ((requested_uid == UINT32_MAX) || (requested_uid == Host::GetEffectiveUserID()))
     {
-        exe_spec.GetPath (exe_path, sizeof(exe_path));
+        xpc_service = "com.apple.lldb.launcherXPCService";
+    }
+    else if (requested_uid == 0)
+    {
+        xpc_service = "com.apple.lldb.launcherRootXPCService";
     }
     else
     {
-        launch_info.GetExecutableFile().GetPath (exe_path, sizeof(exe_path));
-        error.SetErrorStringWithFormat ("executable doesn't exist: '%s'", exe_path);
+        error.SetError(2, eErrorTypeGeneric);
+        if (log)
+        {
+            error.PutToLog(log.get(), "Launching via XPC is only currently available for either the login user or root.");
+        }
+        else
+        {
+            error.SetErrorStringWithFormat("Launching via XPC is only currently available for either the login user or root.");
+        }
         return error;
     }
-
     
-    if (launch_info.GetFlags().Test (eLaunchFlagLaunchInTTY))
+    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_release);
+	xpc_connection_resume (conn);
+    xpc_object_t message = xpc_dictionary_create (nil, nil, 0);
+    
+    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, GetPosixspawnFlags(launch_info));
+    
+    xpc_object_t reply = xpc_connection_send_message_with_reply_sync(conn, message);
+    
+    pid = xpc_dictionary_get_int64(reply, LauncherXPCServiceChildPIDKey);
+    if (pid == 0)
     {
-#if !defined(__arm__)
-        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
+        int errorType = xpc_dictionary_get_int64(reply, LauncherXPCServiceErrorTypeKey);
+        int errorCode = xpc_dictionary_get_int64(reply, LauncherXPCServiceCodeTypeKey);
+        
+        error.SetError(errorCode, eErrorTypeGeneric);
+        if (log)
+        {
+            error.PutToLog(log.get(), "Problems with launching via XPC. Error type : %i, code : %i", errorType, errorCode);
+        }
+        else {
+            error.SetErrorStringWithFormat("Problems with launching via XPC. Error type : %i, code : %i", errorType, errorCode);
+        }
     }
+#endif
     
-    Error local_err;    // Errors that don't affect the spawning.
+    return error;
+}
+
+static Error
+LaunchProcessPosixSpawn (const char *exe_path, ProcessLaunchInfo &launch_info, ::pid_t &pid)
+{
+    Error error;
+    LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_HOST | LIBLLDB_LOG_PROCESS));
+    
     posix_spawnattr_t attr;
     error.SetError( ::posix_spawnattr_init (&attr), eErrorTypePOSIX);
     
@@ -1289,21 +1459,7 @@
     ::posix_spawnattr_setsigmask(&attr, &no_signals);
     ::posix_spawnattr_setsigdefault(&attr, &all_signals);
 
-    short flags = POSIX_SPAWN_SETSIGDEF | POSIX_SPAWN_SETSIGMASK;
-    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
-    
-//#ifdef POSIX_SPAWN_CLOEXEC_DEFAULT
-//    // Close all files exception those with file actions if this is supported.
-//    flags |= POSIX_SPAWN_CLOEXEC_DEFAULT;       
-//#endif
-
+    short flags = GetPosixspawnFlags(launch_info);
     error.SetError( ::posix_spawnattr_setflags (&attr, flags), eErrorTypePOSIX);
     if (error.Fail() || log)
         error.PutToLog(log.get(), "::posix_spawnattr_setflags ( &attr, flags=0x%8.8x )", flags);
@@ -1315,6 +1471,7 @@
     // We don't need to do this for ARM, and we really shouldn't now that we
     // have multiple CPU subtypes and no posix_spawnattr call that allows us
     // to set which CPU subtype to launch...
+    const ArchSpec &arch_spec = launch_info.GetArchitecture();
     cpu_type_t cpu = arch_spec.GetMachOCPUType();
     if (cpu != 0 && 
         cpu != UINT32_MAX && 
@@ -1330,7 +1487,7 @@
     }
     
 #endif
-    ::pid_t pid = LLDB_INVALID_PROCESS_ID;
+    
     const char *tmp_argv[2];
     char * const *argv = (char * const*)launch_info.GetArguments().GetConstArgumentVector();
     char * const *envp = (char * const*)launch_info.GetEnvironmentEntries().GetConstArgumentVector();
@@ -1420,7 +1577,98 @@
         // No more thread specific current working directory
         __pthread_fchdir (-1);
     }
+    
+    return error;
+}
 
+static bool
+ShouldLaunchUsingXPC(const char *exe_path, ProcessLaunchInfo &launch_info)
+{
+    bool result = false;
+
+#if !BUILDING_ON_SNOW_LEOPARD    
+    const char *debugserver = "/debugserver";
+    int len = strlen(debugserver);
+    int exe_len = strlen(exe_path);
+    if (exe_len >= len)
+    {
+        const char *part = exe_path + (exe_len - len);
+        if (strcmp(part, debugserver) == 0)
+        {
+            // We are dealing with debugserver.
+            uid_t requested_uid = launch_info.GetUserID();
+            if (requested_uid == 0)
+            {
+                // Launching XPC works for root. It also works for the non-attaching case for current login
+                // but unfortunately, we can't detect it here.
+                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__)
+        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(exe_path, 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
diff --git a/source/Host/macosx/launcherXPCService/LauncherRootXPCService-Info.plist b/source/Host/macosx/launcherXPCService/LauncherRootXPCService-Info.plist
new file mode 100644
index 0000000..f797f90
--- /dev/null
+++ b/source/Host/macosx/launcherXPCService/LauncherRootXPCService-Info.plist
@@ -0,0 +1,44 @@
+#if RC_XBS && !RC_BUILDIT
+#define AND_APPLE_CODE_SIGNED and ${IS_APPLE_CODE_SIGNED}
+#else 
+#define AND_APPLE_CODE_SIGNED
+#endif
+
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>English</string>
+	<key>CFBundleExecutable</key>
+	<string>${EXECUTABLE_NAME}</string>
+	<key>CFBundleIdentifier</key>
+	<string>${EXECUTABLE_NAME}</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>${PRODUCT_NAME}</string>
+	<key>CFBundlePackageType</key>
+	<string>XPC!</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>NSHumanReadableCopyright</key>
+	<string>Copyright © 2012 Apple Inc. All rights reserved.</string>
+	<key>XPCService</key>
+	<dict>
+		<key>_AllowedClients</key>
+		<array>
+			<string> identifier = com.apple.lldb AND_APPLE_CODE_SIGNED</string>
+			<string> identifier = com.apple.dt.Xcode AND_APPLE_CODE_SIGNED</string>
+		</array>
+		<key>_RoleAccount</key>
+		<string>root</string>
+		<key>ServiceType</key>
+		<string>Application</string>
+	</dict>
+</dict>
+</plist>
diff --git a/source/Host/macosx/launcherXPCService/LauncherXPCService-Info.plist b/source/Host/macosx/launcherXPCService/LauncherXPCService-Info.plist
new file mode 100644
index 0000000..31c8c5a
--- /dev/null
+++ b/source/Host/macosx/launcherXPCService/LauncherXPCService-Info.plist
@@ -0,0 +1,44 @@
+#if RC_XBS && !RC_BUILDIT
+#define AND_APPLE_CODE_SIGNED and ${IS_APPLE_CODE_SIGNED}
+#else 
+#define AND_APPLE_CODE_SIGNED
+#endif
+
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>English</string>
+	<key>CFBundleExecutable</key>
+	<string>${EXECUTABLE_NAME}</string>
+	<key>CFBundleIdentifier</key>
+	<string>${EXECUTABLE_NAME}</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>${PRODUCT_NAME}</string>
+	<key>CFBundlePackageType</key>
+	<string>XPC!</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>NSHumanReadableCopyright</key>
+	<string>Copyright © 2012 Apple Inc. All rights reserved.</string>
+	<key>XPCService</key>
+	<dict>
+		<key>_AllowedClients</key>
+		<array>
+			<string> identifier = com.apple.lldb AND_APPLE_CODE_SIGNED</string>
+			<string> identifier = com.apple.dt.Xcode AND_APPLE_CODE_SIGNED</string>
+		</array>
+		<key>ServiceType</key>
+		<string>Application</string>
+        <key>JoinExistingSession</key>
+        <true/>
+	</dict>
+</dict>
+</plist>
diff --git a/source/Host/macosx/launcherXPCService/LauncherXPCService.entitlements b/source/Host/macosx/launcherXPCService/LauncherXPCService.entitlements
new file mode 100644
index 0000000..a3088cc
--- /dev/null
+++ b/source/Host/macosx/launcherXPCService/LauncherXPCService.entitlements
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>com.apple.private.xpc.role-account</key>
+	<true/>
+</dict>
+</plist>
diff --git a/source/Host/macosx/launcherXPCService/LauncherXPCService.h b/source/Host/macosx/launcherXPCService/LauncherXPCService.h
new file mode 100644
index 0000000..071cea7
--- /dev/null
+++ b/source/Host/macosx/launcherXPCService/LauncherXPCService.h
@@ -0,0 +1,13 @@
+#ifndef LLDB_LauncherXPCService_h
+#define LLDB_LauncherXPCService_h
+
+// These XPC messaging keys are used for communication between Host.mm and the XPC service.
+#define LauncherXPCServiceArgPrefxKey           "arg"
+#define LauncherXPCServiceEnvPrefxKey           "env"
+#define LauncherXPCServiceCPUTypeKey            "cpuType"
+#define LauncherXPCServicePosixspawnFlagsKey    "posixspawnFlags"
+#define LauncherXPCServiceChildPIDKey           "childPID"
+#define LauncherXPCServiceErrorTypeKey          "errorType"
+#define LauncherXPCServiceCodeTypeKey           "errorCode"
+
+#endif
diff --git a/source/Host/macosx/launcherXPCService/LauncherXPCService.mm b/source/Host/macosx/launcherXPCService/LauncherXPCService.mm
new file mode 100644
index 0000000..9ffae6d
--- /dev/null
+++ b/source/Host/macosx/launcherXPCService/LauncherXPCService.mm
@@ -0,0 +1,185 @@
+//
+//  LauncherXPCService.m
+//  LauncherXPCService
+//
+//  Copyright (c) 2012 Apple Inc. All rights reserved.
+//
+#include <AvailabilityMacros.h>
+
+#if !defined(MAC_OS_X_VERSION_10_7) || MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_7
+#define BUILDING_ON_SNOW_LEOPARD 1
+#endif
+
+#if !BUILDING_ON_SNOW_LEOPARD
+#include <xpc/xpc.h>
+#include <spawn.h>
+#include <signal.h>
+#include <assert.h>
+#include "LauncherXPCService.h"
+
+// Returns 0 if successful.
+int _setup_posixspawn_attributes_file_actions(xpc_object_t message, posix_spawnattr_t *attr, posix_spawn_file_actions_t *file_actions)
+{
+    *attr = 0;
+    
+    int errorCode = posix_spawnattr_init(attr);
+    if (errorCode)
+        return errorCode;
+    
+    cpu_type_t cpuType = xpc_dictionary_get_int64(message, LauncherXPCServiceCPUTypeKey);
+    if (cpuType == -2) {
+        cpuType= CPU_TYPE_ANY;
+    }
+    size_t realCount;
+    errorCode = posix_spawnattr_setbinpref_np(attr, 1, &cpuType, &realCount);
+    if (errorCode)
+        return errorCode;
+    
+    sigset_t no_signals;
+    sigset_t all_signals;
+    sigemptyset (&no_signals);
+    sigfillset (&all_signals);
+    posix_spawnattr_setsigmask(attr, &no_signals);
+    posix_spawnattr_setsigdefault(attr, &all_signals);
+    
+    short flags = xpc_dictionary_get_int64(message, LauncherXPCServicePosixspawnFlagsKey);
+    errorCode = posix_spawnattr_setflags(attr, flags);
+    if (errorCode)
+        return errorCode;
+
+    // Setup any file actions. Here we are emulating what debugserver would do normally in Host.mm since the XPC service meant only for debugserver.
+    errorCode = posix_spawn_file_actions_init(file_actions);
+    if (errorCode)
+        return errorCode;
+    errorCode = posix_spawn_file_actions_addclose(file_actions, STDIN_FILENO);
+    if (errorCode)
+        return errorCode;
+    errorCode = posix_spawn_file_actions_addclose(file_actions, STDOUT_FILENO);
+    if (errorCode)
+        return errorCode;
+    errorCode = posix_spawn_file_actions_addclose(file_actions, STDERR_FILENO);
+    
+    return errorCode;
+}
+
+bool extract_args(xpc_object_t message, const char *prefix, const char ***argsOut)
+{
+    char buf[50]; // long enough for 'argXXX'
+    memset(buf, 0, 50);
+    sprintf(buf, "%sCount", prefix);
+    int argsCount = xpc_dictionary_get_int64(message, buf);
+    if (argsCount == 0) {
+        return true;
+    }
+    
+    const char **argsp = NULL;
+    argsp = (const char **)malloc((argsCount+1) * sizeof(argsp[0]));
+    if (argsp == NULL) {
+        return false;
+    }
+    
+    for (int i=0; i<argsCount; i++) {
+        memset(buf, 0, 50);
+        sprintf(buf, "%s%i", prefix, i);
+        const char *arg = xpc_dictionary_get_string(message, buf);
+        argsp[i] = arg;
+    }
+    argsp[argsCount] = NULL;
+    
+    *argsOut = argsp;
+    return true;
+}
+
+// Returns 0 if successful.
+int get_args(xpc_object_t message, const char **path, const char ***argsOut, const char ***envOut)
+{
+    if (!extract_args(message, LauncherXPCServiceArgPrefxKey, argsOut)) {
+        return 1;
+    }
+    *path = (*argsOut)[0];
+    
+    if (!extract_args(message, LauncherXPCServiceEnvPrefxKey, envOut)) {
+        return 2;
+    }
+
+    return 0;
+}
+
+static void launcherXPC_peer_event_handler(xpc_connection_t peer, xpc_object_t event) 
+{
+	xpc_type_t type = xpc_get_type(event);
+	if (type == XPC_TYPE_ERROR) {
+		if (event == XPC_ERROR_CONNECTION_INVALID) {
+			// The client process on the other end of the connection has either
+			// crashed or cancelled the connection. After receiving this error,
+			// the connection is in an invalid state, and you do not need to
+			// call xpc_connection_cancel(). Just tear down any associated state
+			// here.
+		} else if (event == XPC_ERROR_TERMINATION_IMMINENT) {
+			// Handle per-connection termination cleanup.
+		}
+	} else {
+		assert(type == XPC_TYPE_DICTIONARY);
+		// Handle the message.
+        
+        pid_t childPID = 0;
+        posix_spawn_file_actions_t file_actions;
+        posix_spawnattr_t attributes;
+        
+        /*
+         Types of error. Error code will be specific to each type.
+         1 - posixspawn attributes problem
+         2 - get args/env problem
+         3 - posixspawn problem
+         */
+        int errorType = 1;
+        int errorCode = _setup_posixspawn_attributes_file_actions(event, &attributes, &file_actions);
+        if (!errorCode) {
+            const char *path = NULL;
+            const char **argvp = NULL;
+            const char **envp = NULL;
+            errorType = 2;
+            errorCode = get_args(event, &path, &argvp, &envp);
+            if (!errorCode) {
+                errorType = 3;
+                errorCode = posix_spawn(&childPID, path, &file_actions, &attributes, (char * const *)argvp, (char * const *)envp);
+                
+                if (argvp) free(argvp);
+                if (envp) free(envp);
+            }
+        }
+        
+      	xpc_object_t reply = xpc_dictionary_create_reply(event);
+        
+        xpc_dictionary_set_int64(reply, LauncherXPCServiceChildPIDKey, childPID);
+        if (!childPID) {
+            xpc_dictionary_set_int64(reply, LauncherXPCServiceErrorTypeKey, errorType);            
+            xpc_dictionary_set_int64(reply, LauncherXPCServiceCodeTypeKey, errorCode);            
+        }
+        
+        xpc_connection_send_message(peer, reply);
+		xpc_release(reply);
+
+	}
+}
+
+static void launcherXPC_event_handler(xpc_connection_t peer) 
+{
+	// By defaults, new connections will target the default dispatch
+	// concurrent queue.
+	xpc_connection_set_event_handler(peer, ^(xpc_object_t event) {
+		launcherXPC_peer_event_handler(peer, event);
+	});
+	
+	// This will tell the connection to begin listening for events. If you
+	// have some other initialization that must be done asynchronously, then
+	// you can defer this call until after that initialization is done.
+	xpc_connection_resume(peer);
+}
+
+int main(int argc, const char *argv[])
+{
+	xpc_main(launcherXPC_event_handler);
+	return 0;
+}
+#endif