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

#include "PlatformDarwin.h"

// C Includes
// C++ Includes
// Other libraries and framework includes
#include "clang/Basic/VersionTuple.h"
// Project includes
#include "lldb/Breakpoint/BreakpointLocation.h"
#include "lldb/Breakpoint/BreakpointSite.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Core/Error.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/ModuleSpec.h"
#include "lldb/Core/Timer.h"
#include "lldb/Host/Host.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/Symbols.h"
#include "lldb/Interpreter/CommandInterpreter.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Symbol/SymbolFile.h"
#include "lldb/Symbol/SymbolVendor.h"
#include "lldb/Target/Target.h"
#include "llvm/ADT/STLExtras.h"

using namespace lldb;
using namespace lldb_private;
    

//------------------------------------------------------------------
/// Default Constructor
//------------------------------------------------------------------
PlatformDarwin::PlatformDarwin (bool is_host) :
    PlatformPOSIX(is_host),  // This is the local host platform
    m_developer_directory ()
{
}

//------------------------------------------------------------------
/// Destructor.
///
/// The destructor is virtual since this class is designed to be
/// inherited from by the plug-in instance.
//------------------------------------------------------------------
PlatformDarwin::~PlatformDarwin()
{
}

FileSpecList
PlatformDarwin::LocateExecutableScriptingResources (Target *target,
                                                    Module &module,
                                                    Stream* feedback_stream)
{
    FileSpecList file_list;
    if (target && target->GetDebugger().GetScriptLanguage() == eScriptLanguagePython)
    {
        // NB some extensions might be meaningful and should not be stripped - "this.binary.file"
        // should not lose ".file" but GetFileNameStrippingExtension() will do precisely that.
        // Ideally, we should have a per-platform list of extensions (".exe", ".app", ".dSYM", ".framework")
        // which should be stripped while leaving "this.binary.file" as-is.
        ScriptInterpreter *script_interpreter = target->GetDebugger().GetCommandInterpreter().GetScriptInterpreter();
        
        FileSpec module_spec = module.GetFileSpec();
        
        if (module_spec)
        {
            SymbolVendor *symbols = module.GetSymbolVendor ();
            if (symbols)
            {
                SymbolFile *symfile = symbols->GetSymbolFile();
                if (symfile)
                {
                    ObjectFile *objfile = symfile->GetObjectFile();
                    if (objfile)
                    {
                        FileSpec symfile_spec (objfile->GetFileSpec());
                        if (symfile_spec && symfile_spec.Exists())
                        {
                            while (module_spec.GetFilename())
                            {
                                std::string module_basename (module_spec.GetFilename().GetCString());
                                std::string original_module_basename (module_basename);
                                
                                bool was_keyword = false;

                                // FIXME: for Python, we cannot allow certain characters in module
                                // filenames we import. Theoretically, different scripting languages may
                                // have different sets of forbidden tokens in filenames, and that should
                                // be dealt with by each ScriptInterpreter. For now, we just replace dots
                                // with underscores, but if we ever support anything other than Python
                                // we will need to rework this
                                std::replace(module_basename.begin(), module_basename.end(), '.', '_');
                                std::replace(module_basename.begin(), module_basename.end(), ' ', '_');
                                std::replace(module_basename.begin(), module_basename.end(), '-', '_');
                                if (script_interpreter && script_interpreter->IsReservedWord(module_basename.c_str()))
                                {
                                    module_basename.insert(module_basename.begin(), '_');
                                    was_keyword = true;
                                }

                                StreamString path_string;
                                StreamString original_path_string;
                                // for OSX we are going to be in .dSYM/Contents/Resources/DWARF/<basename>
                                // let us go to .dSYM/Contents/Resources/Python/<basename>.py and see if the file exists
                                path_string.Printf("%s/../Python/%s.py",symfile_spec.GetDirectory().GetCString(), module_basename.c_str());
                                original_path_string.Printf("%s/../Python/%s.py",symfile_spec.GetDirectory().GetCString(), original_module_basename.c_str());
                                FileSpec script_fspec(path_string.GetData(), true);
                                FileSpec orig_script_fspec(original_path_string.GetData(), true);
                                
                                // if we did some replacements of reserved characters, and a file with the untampered name
                                // exists, then warn the user that the file as-is shall not be loaded
                                if (feedback_stream)
                                {
                                    if (module_basename != original_module_basename
                                        && orig_script_fspec.Exists())
                                    {
                                        const char* reason_for_complaint = was_keyword ? "conflicts with a keyword" : "contains reserved characters";
                                        if (script_fspec.Exists())
                                            feedback_stream->Printf("warning: the symbol file '%s' contains a debug script. However, its name"
                                                                    " '%s' %s and as such cannot be loaded. LLDB will"
                                                                    " load '%s' instead. Consider removing the file with the malformed name to"
                                                                    " eliminate this warning.\n",
                                                                    symfile_spec.GetPath().c_str(),
                                                                    original_path_string.GetData(),
                                                                    reason_for_complaint,
                                                                    path_string.GetData());
                                        else
                                            feedback_stream->Printf("warning: the symbol file '%s' contains a debug script. However, its name"
                                                                    " %s and as such cannot be loaded. If you intend"
                                                                    " to have this script loaded, please rename '%s' to '%s' and retry.\n",
                                                                    symfile_spec.GetPath().c_str(),
                                                                    reason_for_complaint,
                                                                    original_path_string.GetData(),
                                                                    path_string.GetData());
                                    }
                                }
                                
                                if (script_fspec.Exists())
                                {
                                    file_list.Append (script_fspec);
                                    break;
                                }
                                
                                // If we didn't find the python file, then keep
                                // stripping the extensions and try again
                                ConstString filename_no_extension (module_spec.GetFileNameStrippingExtension());
                                if (module_spec.GetFilename() == filename_no_extension)
                                    break;
                                
                                module_spec.GetFilename() = filename_no_extension;
                            }
                        }
                    }
                }
            }
        }
    }
    return file_list;
}

Error
PlatformDarwin::ResolveExecutable (const ModuleSpec &module_spec,
                                   lldb::ModuleSP &exe_module_sp,
                                   const FileSpecList *module_search_paths_ptr)
{
    Error error;
    // Nothing special to do here, just use the actual file and architecture

    char exe_path[PATH_MAX];
    ModuleSpec resolved_module_spec(module_spec);

    if (IsHost())
    {
        // If we have "ls" as the exe_file, resolve the executable loation based on
        // the current path variables
        if (!resolved_module_spec.GetFileSpec().Exists())
        {
            module_spec.GetFileSpec().GetPath (exe_path, sizeof(exe_path));
            resolved_module_spec.GetFileSpec().SetFile(exe_path, true);
        }

        if (!resolved_module_spec.GetFileSpec().Exists())
            resolved_module_spec.GetFileSpec().ResolveExecutableLocation ();

        // Resolve any executable within a bundle on MacOSX
        Host::ResolveExecutableInBundle (resolved_module_spec.GetFileSpec());
        
        if (resolved_module_spec.GetFileSpec().Exists())
            error.Clear();
        else
        {
            const uint32_t permissions = resolved_module_spec.GetFileSpec().GetPermissions();
            if (permissions && (permissions & eFilePermissionsEveryoneR) == 0)
                error.SetErrorStringWithFormat ("executable '%s' is not readable", resolved_module_spec.GetFileSpec().GetPath().c_str());
            else
                error.SetErrorStringWithFormat ("unable to find executable for '%s'", resolved_module_spec.GetFileSpec().GetPath().c_str());
        }
    }
    else
    {
        if (m_remote_platform_sp)
        {
            error = GetCachedExecutable (resolved_module_spec, exe_module_sp, module_search_paths_ptr, *m_remote_platform_sp);
        }
        else
        {
            // We may connect to a process and use the provided executable (Don't use local $PATH).

            // Resolve any executable within a bundle on MacOSX
            Host::ResolveExecutableInBundle (resolved_module_spec.GetFileSpec());

            if (resolved_module_spec.GetFileSpec().Exists())
                error.Clear();
            else
                error.SetErrorStringWithFormat("the platform is not currently connected, and '%s' doesn't exist in the system root.", resolved_module_spec.GetFileSpec().GetFilename().AsCString(""));
        }
    }
    

    if (error.Success())
    {
        if (resolved_module_spec.GetArchitecture().IsValid())
        {
            error = ModuleList::GetSharedModule (resolved_module_spec,
                                                 exe_module_sp,
                                                 module_search_paths_ptr,
                                                 NULL,
                                                 NULL);

            if (error.Fail() || exe_module_sp.get() == NULL || exe_module_sp->GetObjectFile() == NULL)
            {
                exe_module_sp.reset();
                error.SetErrorStringWithFormat ("'%s' doesn't contain the architecture %s",
                                                resolved_module_spec.GetFileSpec().GetPath().c_str(),
                                                resolved_module_spec.GetArchitecture().GetArchitectureName());
            }
        }
        else
        {
            // No valid architecture was specified, ask the platform for
            // the architectures that we should be using (in the correct order)
            // and see if we can find a match that way
            StreamString arch_names;
            for (uint32_t idx = 0; GetSupportedArchitectureAtIndex (idx, resolved_module_spec.GetArchitecture()); ++idx)
            {
                error = GetSharedModule (resolved_module_spec,
                                         NULL,
                                         exe_module_sp,
                                         module_search_paths_ptr,
                                         NULL,
                                         NULL);
                // Did we find an executable using one of the
                if (error.Success())
                {
                    if (exe_module_sp && exe_module_sp->GetObjectFile())
                        break;
                    else
                        error.SetErrorToGenericError();
                }
                
                if (idx > 0)
                    arch_names.PutCString (", ");
                arch_names.PutCString (resolved_module_spec.GetArchitecture().GetArchitectureName());
            }
            
            if (error.Fail() || !exe_module_sp)
            {
                if (resolved_module_spec.GetFileSpec().Readable())
                {
                    error.SetErrorStringWithFormat ("'%s' doesn't contain any '%s' platform architectures: %s",
                                                    resolved_module_spec.GetFileSpec().GetPath().c_str(),
                                                    GetPluginName().GetCString(),
                                                    arch_names.GetString().c_str());
                }
                else
                {
                    error.SetErrorStringWithFormat("'%s' is not readable", resolved_module_spec.GetFileSpec().GetPath().c_str());
                }
            }
        }
    }

    return error;
}

Error
PlatformDarwin::ResolveSymbolFile (Target &target,
                                   const ModuleSpec &sym_spec,
                                   FileSpec &sym_file)
{
    Error error;
    sym_file = sym_spec.GetSymbolFileSpec();
    if (sym_file.Exists())
    {
        if (sym_file.GetFileType() == FileSpec::eFileTypeDirectory)
        {
            sym_file = Symbols::FindSymbolFileInBundle (sym_file,
                                                        sym_spec.GetUUIDPtr(),
                                                        sym_spec.GetArchitecturePtr());
        }
    }
    else
    {
        if (sym_spec.GetUUID().IsValid())
        {
            
        }
    }
    return error;
    
}

static lldb_private::Error
MakeCacheFolderForFile (const FileSpec& module_cache_spec)
{
    FileSpec module_cache_folder = module_cache_spec.CopyByRemovingLastPathComponent();
    return FileSystem::MakeDirectory(module_cache_folder, eFilePermissionsDirectoryDefault);
}

static lldb_private::Error
BringInRemoteFile (Platform* platform,
                   const lldb_private::ModuleSpec &module_spec,
                   const FileSpec& module_cache_spec)
{
    MakeCacheFolderForFile(module_cache_spec);
    Error err = platform->GetFile(module_spec.GetFileSpec(), module_cache_spec);
    return err;
}

lldb_private::Error
PlatformDarwin::GetSharedModuleWithLocalCache (const lldb_private::ModuleSpec &module_spec,
                                               lldb::ModuleSP &module_sp,
                                               const lldb_private::FileSpecList *module_search_paths_ptr,
                                               lldb::ModuleSP *old_module_sp_ptr,
                                               bool *did_create_ptr)
{

    Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM));
    if (log)
        log->Printf("[%s] Trying to find module %s/%s - platform path %s/%s symbol path %s/%s",
                     (IsHost() ? "host" : "remote"),
                     module_spec.GetFileSpec().GetDirectory().AsCString(),
                     module_spec.GetFileSpec().GetFilename().AsCString(),
                     module_spec.GetPlatformFileSpec().GetDirectory().AsCString(),
                     module_spec.GetPlatformFileSpec().GetFilename().AsCString(),
                     module_spec.GetSymbolFileSpec().GetDirectory().AsCString(),
                     module_spec.GetSymbolFileSpec().GetFilename().AsCString());
    
    Error err;
    
    err = ModuleList::GetSharedModule(module_spec, module_sp, module_search_paths_ptr, old_module_sp_ptr, did_create_ptr);
    if (module_sp)
        return err;
    
    if (!IsHost())
    {
        std::string cache_path(GetLocalCacheDirectory());
        // Only search for a locally cached file if we have a valid cache path
        if (!cache_path.empty())
        {
            std::string module_path (module_spec.GetFileSpec().GetPath());
            cache_path.append(module_path);
            FileSpec module_cache_spec(cache_path.c_str(),false);
        
            // if rsync is supported, always bring in the file - rsync will be very efficient
            // when files are the same on the local and remote end of the connection
            if (this->GetSupportsRSync())
            {
                err = BringInRemoteFile (this, module_spec, module_cache_spec);
                if (err.Fail())
                    return err;
                if (module_cache_spec.Exists())
                {
                    Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM));
                    if (log)
                        log->Printf("[%s] module %s/%s was rsynced and is now there",
                                     (IsHost() ? "host" : "remote"),
                                     module_spec.GetFileSpec().GetDirectory().AsCString(),
                                     module_spec.GetFileSpec().GetFilename().AsCString());
                    ModuleSpec local_spec(module_cache_spec, module_spec.GetArchitecture());
                    module_sp.reset(new Module(local_spec));
                    module_sp->SetPlatformFileSpec(module_spec.GetFileSpec());
                    return Error();
                }
            }
            
            // try to find the module in the cache
            if (module_cache_spec.Exists())
            {
                // get the local and remote MD5 and compare
                if (m_remote_platform_sp)
                {
                    // when going over the *slow* GDB remote transfer mechanism we first check
                    // the hashes of the files - and only do the actual transfer if they differ
                    uint64_t high_local,high_remote,low_local,low_remote;
                    FileSystem::CalculateMD5(module_cache_spec, low_local, high_local);
                    m_remote_platform_sp->CalculateMD5(module_spec.GetFileSpec(), low_remote, high_remote);
                    if (low_local != low_remote || high_local != high_remote)
                    {
                        // bring in the remote file
                        Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM));
                        if (log)
                            log->Printf("[%s] module %s/%s needs to be replaced from remote copy",
                                         (IsHost() ? "host" : "remote"),
                                         module_spec.GetFileSpec().GetDirectory().AsCString(),
                                         module_spec.GetFileSpec().GetFilename().AsCString());
                        Error err = BringInRemoteFile (this, module_spec, module_cache_spec);
                        if (err.Fail())
                            return err;
                    }
                }
                
                ModuleSpec local_spec(module_cache_spec, module_spec.GetArchitecture());
                module_sp.reset(new Module(local_spec));
                module_sp->SetPlatformFileSpec(module_spec.GetFileSpec());
                Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM));
                    if (log)
                        log->Printf("[%s] module %s/%s was found in the cache",
                                     (IsHost() ? "host" : "remote"),
                                     module_spec.GetFileSpec().GetDirectory().AsCString(),
                                     module_spec.GetFileSpec().GetFilename().AsCString());
                return Error();
            }
            
            // bring in the remote module file
            if (log)
                log->Printf("[%s] module %s/%s needs to come in remotely",
                             (IsHost() ? "host" : "remote"),
                             module_spec.GetFileSpec().GetDirectory().AsCString(),
                             module_spec.GetFileSpec().GetFilename().AsCString());
            Error err = BringInRemoteFile (this, module_spec, module_cache_spec);
            if (err.Fail())
                return err;
            if (module_cache_spec.Exists())
            {
                Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM));
                if (log)
                    log->Printf("[%s] module %s/%s is now cached and fine",
                                 (IsHost() ? "host" : "remote"),
                                 module_spec.GetFileSpec().GetDirectory().AsCString(),
                                 module_spec.GetFileSpec().GetFilename().AsCString());
                ModuleSpec local_spec(module_cache_spec, module_spec.GetArchitecture());
                module_sp.reset(new Module(local_spec));
                module_sp->SetPlatformFileSpec(module_spec.GetFileSpec());
                return Error();
            }
            else
                return Error("unable to obtain valid module file");
        }
        else
            return Error("no cache path");
    }
    else
        return Error ("unable to resolve module");
}

Error
PlatformDarwin::GetSharedModule (const ModuleSpec &module_spec,
                                 Process* process,
                                 ModuleSP &module_sp,
                                 const FileSpecList *module_search_paths_ptr,
                                 ModuleSP *old_module_sp_ptr,
                                 bool *did_create_ptr)
{
    Error error;
    module_sp.reset();
    
    if (IsRemote())
    {
        // If we have a remote platform always, let it try and locate
        // the shared module first.
        if (m_remote_platform_sp)
        {
            error = m_remote_platform_sp->GetSharedModule (module_spec,
                                                           process,
                                                           module_sp,
                                                           module_search_paths_ptr,
                                                           old_module_sp_ptr,
                                                           did_create_ptr);
        }
    }
    
    if (!module_sp)
    {
        // Fall back to the local platform and find the file locally
        error = Platform::GetSharedModule (module_spec,
                                           process,
                                           module_sp,
                                           module_search_paths_ptr,
                                           old_module_sp_ptr,
                                           did_create_ptr);
        
        const FileSpec &platform_file = module_spec.GetFileSpec();
        if (!module_sp && module_search_paths_ptr && platform_file)
        {
            // We can try to pull off part of the file path up to the bundle
            // directory level and try any module search paths...
            FileSpec bundle_directory;
            if (Host::GetBundleDirectory (platform_file, bundle_directory))
            {
                if (platform_file == bundle_directory)
                {
                    ModuleSpec new_module_spec (module_spec);
                    new_module_spec.GetFileSpec() = bundle_directory;
                    if (Host::ResolveExecutableInBundle (new_module_spec.GetFileSpec()))
                    {
                        Error new_error (Platform::GetSharedModule (new_module_spec,
                                                                    process,
                                                                    module_sp,
                                                                    NULL,
                                                                    old_module_sp_ptr,
                                                                    did_create_ptr));
                        
                        if (module_sp)
                            return new_error;
                    }
                }
                else
                {
                    char platform_path[PATH_MAX];
                    char bundle_dir[PATH_MAX];
                    platform_file.GetPath (platform_path, sizeof(platform_path));
                    const size_t bundle_directory_len = bundle_directory.GetPath (bundle_dir, sizeof(bundle_dir));
                    char new_path[PATH_MAX];
                    size_t num_module_search_paths = module_search_paths_ptr->GetSize();
                    for (size_t i=0; i<num_module_search_paths; ++i)
                    {
                        const size_t search_path_len = module_search_paths_ptr->GetFileSpecAtIndex(i).GetPath(new_path, sizeof(new_path));
                        if (search_path_len < sizeof(new_path))
                        {
                            snprintf (new_path + search_path_len, sizeof(new_path) - search_path_len, "/%s", platform_path + bundle_directory_len);
                            FileSpec new_file_spec (new_path, false);
                            if (new_file_spec.Exists())
                            {
                                ModuleSpec new_module_spec (module_spec);
                                new_module_spec.GetFileSpec() = new_file_spec;
                                Error new_error (Platform::GetSharedModule (new_module_spec,
                                                                            process,
                                                                            module_sp,
                                                                            NULL,
                                                                            old_module_sp_ptr,
                                                                            did_create_ptr));
                                
                                if (module_sp)
                                {
                                    module_sp->SetPlatformFileSpec(new_file_spec);
                                    return new_error;
                                }
                            }
                        }
                    }
                }
            }
        }
    }
    if (module_sp)
        module_sp->SetPlatformFileSpec(module_spec.GetFileSpec());
    return error;
}

size_t
PlatformDarwin::GetSoftwareBreakpointTrapOpcode (Target &target, BreakpointSite *bp_site)
{
    const uint8_t *trap_opcode = NULL;
    uint32_t trap_opcode_size = 0;
    bool bp_is_thumb = false;
        
    llvm::Triple::ArchType machine = target.GetArchitecture().GetMachine();
    switch (machine)
    {
    case llvm::Triple::x86:
    case llvm::Triple::x86_64:
        {
            static const uint8_t g_i386_breakpoint_opcode[] = { 0xCC };
            trap_opcode = g_i386_breakpoint_opcode;
            trap_opcode_size = sizeof(g_i386_breakpoint_opcode);
        }
        break;

    case llvm::Triple::aarch64:
        {
            // TODO: fix this with actual darwin breakpoint opcode for arm64.
            // right now debugging uses the Z packets with GDB remote so this
            // is not needed, but the size needs to be correct...
            static const uint8_t g_arm64_breakpoint_opcode[] = { 0xFE, 0xDE, 0xFF, 0xE7 };
            trap_opcode = g_arm64_breakpoint_opcode;
            trap_opcode_size = sizeof(g_arm64_breakpoint_opcode);
        }
        break;

    case llvm::Triple::thumb:
        bp_is_thumb = true; // Fall through...
    case llvm::Triple::arm:
        {
            static const uint8_t g_arm_breakpoint_opcode[] = { 0xFE, 0xDE, 0xFF, 0xE7 };
            static const uint8_t g_thumb_breakpooint_opcode[] = { 0xFE, 0xDE };

            // Auto detect arm/thumb if it wasn't explicitly specified
            if (!bp_is_thumb)
            {
                lldb::BreakpointLocationSP bp_loc_sp (bp_site->GetOwnerAtIndex (0));
                if (bp_loc_sp)
                    bp_is_thumb = bp_loc_sp->GetAddress().GetAddressClass () == eAddressClassCodeAlternateISA;
            }
            if (bp_is_thumb)
            {
                trap_opcode = g_thumb_breakpooint_opcode;
                trap_opcode_size = sizeof(g_thumb_breakpooint_opcode);
                break;
            }
            trap_opcode = g_arm_breakpoint_opcode;
            trap_opcode_size = sizeof(g_arm_breakpoint_opcode);
        }
        break;
        
    case llvm::Triple::ppc:
    case llvm::Triple::ppc64:
        {
            static const uint8_t g_ppc_breakpoint_opcode[] = { 0x7F, 0xC0, 0x00, 0x08 };
            trap_opcode = g_ppc_breakpoint_opcode;
            trap_opcode_size = sizeof(g_ppc_breakpoint_opcode);
        }
        break;
        
    default:
        assert(!"Unhandled architecture in PlatformDarwin::GetSoftwareBreakpointTrapOpcode()");
        break;
    }
    
    if (trap_opcode && trap_opcode_size)
    {
        if (bp_site->SetTrapOpcode(trap_opcode, trap_opcode_size))
            return trap_opcode_size;
    }
    return 0;

}

bool
PlatformDarwin::GetProcessInfo (lldb::pid_t pid, ProcessInstanceInfo &process_info)
{
    bool sucess = false;
    if (IsHost())
    {
        sucess = Platform::GetProcessInfo (pid, process_info);
    }
    else
    {
        if (m_remote_platform_sp)
            sucess = m_remote_platform_sp->GetProcessInfo (pid, process_info);
    }
    return sucess;
}

uint32_t
PlatformDarwin::FindProcesses (const ProcessInstanceInfoMatch &match_info,
                               ProcessInstanceInfoList &process_infos)
{
    uint32_t match_count = 0;
    if (IsHost())
    {
        // Let the base class figure out the host details
        match_count = Platform::FindProcesses (match_info, process_infos);
    }
    else
    {
        // If we are remote, we can only return results if we are connected
        if (m_remote_platform_sp)
            match_count = m_remote_platform_sp->FindProcesses (match_info, process_infos);
    }
    return match_count;    
}

bool
PlatformDarwin::ModuleIsExcludedForUnconstrainedSearches (lldb_private::Target &target, const lldb::ModuleSP &module_sp)
{
    if (!module_sp)
        return false;
        
    ObjectFile *obj_file = module_sp->GetObjectFile();
    if (!obj_file)
        return false;
    
    ObjectFile::Type obj_type = obj_file->GetType();
    if (obj_type == ObjectFile::eTypeDynamicLinker)
        return true;
    else
        return false;
}

bool
PlatformDarwin::x86GetSupportedArchitectureAtIndex (uint32_t idx, ArchSpec &arch)
{
    ArchSpec host_arch = HostInfo::GetArchitecture(HostInfo::eArchKindDefault);
    if (host_arch.GetCore() == ArchSpec::eCore_x86_64_x86_64h)
    {
        switch (idx)
        {
            case 0:
                arch = host_arch;
                return true;

            case 1:
                arch.SetTriple("x86_64-apple-macosx");
                return true;

            case 2:
                arch = HostInfo::GetArchitecture(HostInfo::eArchKind32);
                return true;

            default: return false;
        }
    }
    else
    {
        if (idx == 0)
        {
            arch = HostInfo::GetArchitecture(HostInfo::eArchKindDefault);
            return arch.IsValid();
        }
        else if (idx == 1)
        {
            ArchSpec platform_arch(HostInfo::GetArchitecture(HostInfo::eArchKindDefault));
            ArchSpec platform_arch64(HostInfo::GetArchitecture(HostInfo::eArchKind64));
            if (platform_arch.IsExactMatch(platform_arch64))
            {
                // This macosx platform supports both 32 and 64 bit. Since we already
                // returned the 64 bit arch for idx == 0, return the 32 bit arch 
                // for idx == 1
                arch = HostInfo::GetArchitecture(HostInfo::eArchKind32);
                return arch.IsValid();
            }
        }
    }
    return false;
}

// The architecture selection rules for arm processors
// These cpu subtypes have distinct names (e.g. armv7f) but armv7 binaries run fine on an armv7f processor.

bool
PlatformDarwin::ARMGetSupportedArchitectureAtIndex (uint32_t idx, ArchSpec &arch)
{
    ArchSpec system_arch (GetSystemArchitecture());

    const ArchSpec::Core system_core = system_arch.GetCore();
    switch (system_core)
    {
    default:
        switch (idx)
        {
            case  0: arch.SetTriple ("arm64-apple-ios");    return true;
            case  1: arch.SetTriple ("armv7-apple-ios");    return true;
            case  2: arch.SetTriple ("armv7f-apple-ios");   return true;
            case  3: arch.SetTriple ("armv7k-apple-ios");   return true;
            case  4: arch.SetTriple ("armv7s-apple-ios");   return true;
            case  5: arch.SetTriple ("armv7m-apple-ios");   return true;
            case  6: arch.SetTriple ("armv7em-apple-ios");  return true;
            case  7: arch.SetTriple ("armv6m-apple-ios");   return true;
            case  8: arch.SetTriple ("armv6-apple-ios");    return true;
            case  9: arch.SetTriple ("armv5-apple-ios");    return true;
            case 10: arch.SetTriple ("armv4-apple-ios");    return true;
            case 11: arch.SetTriple ("arm-apple-ios");      return true;
            case 12: arch.SetTriple ("thumbv7-apple-ios");  return true;
            case 13: arch.SetTriple ("thumbv7f-apple-ios"); return true;
            case 14: arch.SetTriple ("thumbv7k-apple-ios"); return true;
            case 15: arch.SetTriple ("thumbv7s-apple-ios"); return true;
            case 16: arch.SetTriple ("thumbv7m-apple-ios"); return true;
            case 17: arch.SetTriple ("thumbv7em-apple-ios"); return true;
            case 18: arch.SetTriple ("thumbv6m-apple-ios"); return true;
            case 19: arch.SetTriple ("thumbv6-apple-ios");  return true;
            case 20: arch.SetTriple ("thumbv5-apple-ios");  return true;
            case 21: arch.SetTriple ("thumbv4t-apple-ios"); return true;
            case 22: arch.SetTriple ("thumb-apple-ios");    return true;
            default: break;
        }
        break;

    case ArchSpec::eCore_arm_arm64:
        switch (idx)
        {
            case  0: arch.SetTriple ("arm64-apple-ios");   return true;
            case  1: arch.SetTriple ("armv7s-apple-ios");   return true;
            case  2: arch.SetTriple ("armv7f-apple-ios");   return true;
            case  3: arch.SetTriple ("armv7m-apple-ios");   return true;
            case  4: arch.SetTriple ("armv7em-apple-ios");  return true;
            case  5: arch.SetTriple ("armv7-apple-ios");    return true;
            case  6: arch.SetTriple ("armv6m-apple-ios");   return true;
            case  7: arch.SetTriple ("armv6-apple-ios");    return true;
            case  8: arch.SetTriple ("armv5-apple-ios");    return true;
            case  9: arch.SetTriple ("armv4-apple-ios");    return true;
            case 10: arch.SetTriple ("arm-apple-ios");      return true;
            case 11: arch.SetTriple ("thumbv7-apple-ios");  return true;
            case 12: arch.SetTriple ("thumbv7f-apple-ios"); return true;
            case 13: arch.SetTriple ("thumbv7k-apple-ios"); return true;
            case 14: arch.SetTriple ("thumbv7s-apple-ios"); return true;
            case 15: arch.SetTriple ("thumbv7m-apple-ios"); return true;
            case 16: arch.SetTriple ("thumbv7em-apple-ios"); return true;
            case 17: arch.SetTriple ("thumbv6m-apple-ios"); return true;
            case 18: arch.SetTriple ("thumbv6-apple-ios");  return true;
            case 19: arch.SetTriple ("thumbv5-apple-ios");  return true;
            case 20: arch.SetTriple ("thumbv4t-apple-ios"); return true;
            case 21: arch.SetTriple ("thumb-apple-ios");    return true;
        default: break;
        }
        break;

    case ArchSpec::eCore_arm_armv7f:
        switch (idx)
        {
            case  0: arch.SetTriple ("armv7f-apple-ios");   return true;
            case  1: arch.SetTriple ("armv7-apple-ios");    return true;
            case  2: arch.SetTriple ("armv6m-apple-ios");   return true;
            case  3: arch.SetTriple ("armv6-apple-ios");    return true;
            case  4: arch.SetTriple ("armv5-apple-ios");    return true;
            case  5: arch.SetTriple ("armv4-apple-ios");    return true;
            case  6: arch.SetTriple ("arm-apple-ios");      return true;
            case  7: arch.SetTriple ("thumbv7f-apple-ios"); return true;
            case  8: arch.SetTriple ("thumbv7-apple-ios");  return true;
            case  9: arch.SetTriple ("thumbv6m-apple-ios"); return true;
            case 10: arch.SetTriple ("thumbv6-apple-ios");  return true;
            case 11: arch.SetTriple ("thumbv5-apple-ios");  return true;
            case 12: arch.SetTriple ("thumbv4t-apple-ios"); return true;
            case 13: arch.SetTriple ("thumb-apple-ios");    return true;
            default: break;
        }
        break;

    case ArchSpec::eCore_arm_armv7k:
        switch (idx)
        {
            case  0: arch.SetTriple ("armv7k-apple-ios");   return true;
            case  1: arch.SetTriple ("armv7-apple-ios");    return true;
            case  2: arch.SetTriple ("armv6m-apple-ios");   return true;
            case  3: arch.SetTriple ("armv6-apple-ios");    return true;
            case  4: arch.SetTriple ("armv5-apple-ios");    return true;
            case  5: arch.SetTriple ("armv4-apple-ios");    return true;
            case  6: arch.SetTriple ("arm-apple-ios");      return true;
            case  7: arch.SetTriple ("thumbv7k-apple-ios"); return true;
            case  8: arch.SetTriple ("thumbv7-apple-ios");  return true;
            case  9: arch.SetTriple ("thumbv6m-apple-ios"); return true;
            case 10: arch.SetTriple ("thumbv6-apple-ios");  return true;
            case 11: arch.SetTriple ("thumbv5-apple-ios");  return true;
            case 12: arch.SetTriple ("thumbv4t-apple-ios"); return true;
            case 13: arch.SetTriple ("thumb-apple-ios");    return true;
            default: break;
        }
        break;

    case ArchSpec::eCore_arm_armv7s:
        switch (idx)
        {
            case  0: arch.SetTriple ("armv7s-apple-ios");   return true;
            case  1: arch.SetTriple ("armv7-apple-ios");    return true;
            case  2: arch.SetTriple ("armv6m-apple-ios");   return true;
            case  3: arch.SetTriple ("armv6-apple-ios");    return true;
            case  4: arch.SetTriple ("armv5-apple-ios");    return true;
            case  5: arch.SetTriple ("armv4-apple-ios");    return true;
            case  6: arch.SetTriple ("arm-apple-ios");      return true;
            case  7: arch.SetTriple ("thumbv7s-apple-ios"); return true;
            case  8: arch.SetTriple ("thumbv7-apple-ios");  return true;
            case  9: arch.SetTriple ("thumbv6m-apple-ios"); return true;
            case 10: arch.SetTriple ("thumbv6-apple-ios");  return true;
            case 11: arch.SetTriple ("thumbv5-apple-ios");  return true;
            case 12: arch.SetTriple ("thumbv4t-apple-ios"); return true;
            case 13: arch.SetTriple ("thumb-apple-ios");    return true;
            default: break;
        }
        break;

    case ArchSpec::eCore_arm_armv7m:
        switch (idx)
        {
            case  0: arch.SetTriple ("armv7m-apple-ios");   return true;
            case  1: arch.SetTriple ("armv7-apple-ios");    return true;
            case  2: arch.SetTriple ("armv6m-apple-ios");   return true;
            case  3: arch.SetTriple ("armv6-apple-ios");    return true;
            case  4: arch.SetTriple ("armv5-apple-ios");    return true;
            case  5: arch.SetTriple ("armv4-apple-ios");    return true;
            case  6: arch.SetTriple ("arm-apple-ios");      return true;
            case  7: arch.SetTriple ("thumbv7m-apple-ios"); return true;
            case  8: arch.SetTriple ("thumbv7-apple-ios");  return true;
            case  9: arch.SetTriple ("thumbv6m-apple-ios"); return true;
            case 10: arch.SetTriple ("thumbv6-apple-ios");  return true;
            case 11: arch.SetTriple ("thumbv5-apple-ios");  return true;
            case 12: arch.SetTriple ("thumbv4t-apple-ios"); return true;
            case 13: arch.SetTriple ("thumb-apple-ios");    return true;
            default: break;
        }
        break;

    case ArchSpec::eCore_arm_armv7em:
        switch (idx)
        {
            case  0: arch.SetTriple ("armv7em-apple-ios");  return true;
            case  1: arch.SetTriple ("armv7-apple-ios");    return true;
            case  2: arch.SetTriple ("armv6m-apple-ios");   return true;
            case  3: arch.SetTriple ("armv6-apple-ios");    return true;
            case  4: arch.SetTriple ("armv5-apple-ios");    return true;
            case  5: arch.SetTriple ("armv4-apple-ios");    return true;
            case  6: arch.SetTriple ("arm-apple-ios");      return true;
            case  7: arch.SetTriple ("thumbv7em-apple-ios"); return true;
            case  8: arch.SetTriple ("thumbv7-apple-ios");  return true;
            case  9: arch.SetTriple ("thumbv6m-apple-ios"); return true;
            case 10: arch.SetTriple ("thumbv6-apple-ios");  return true;
            case 11: arch.SetTriple ("thumbv5-apple-ios");  return true;
            case 12: arch.SetTriple ("thumbv4t-apple-ios"); return true;
            case 13: arch.SetTriple ("thumb-apple-ios");    return true;
            default: break;
        }
        break;

    case ArchSpec::eCore_arm_armv7:
        switch (idx)
        {
            case  0: arch.SetTriple ("armv7-apple-ios");    return true;
            case  1: arch.SetTriple ("armv6m-apple-ios");   return true;
            case  2: arch.SetTriple ("armv6-apple-ios");    return true;
            case  3: arch.SetTriple ("armv5-apple-ios");    return true;
            case  4: arch.SetTriple ("armv4-apple-ios");    return true;
            case  5: arch.SetTriple ("arm-apple-ios");      return true;
            case  6: arch.SetTriple ("thumbv7-apple-ios");  return true;
            case  7: arch.SetTriple ("thumbv6m-apple-ios"); return true;
            case  8: arch.SetTriple ("thumbv6-apple-ios");  return true;
            case  9: arch.SetTriple ("thumbv5-apple-ios");  return true;
            case 10: arch.SetTriple ("thumbv4t-apple-ios"); return true;
            case 11: arch.SetTriple ("thumb-apple-ios");    return true;
            default: break;
        }
        break;

    case ArchSpec::eCore_arm_armv6m:
        switch (idx)
        {
            case 0: arch.SetTriple ("armv6m-apple-ios");   return true;
            case 1: arch.SetTriple ("armv6-apple-ios");    return true;
            case 2: arch.SetTriple ("armv5-apple-ios");    return true;
            case 3: arch.SetTriple ("armv4-apple-ios");    return true;
            case 4: arch.SetTriple ("arm-apple-ios");      return true;
            case 5: arch.SetTriple ("thumbv6m-apple-ios"); return true;
            case 6: arch.SetTriple ("thumbv6-apple-ios");  return true;
            case 7: arch.SetTriple ("thumbv5-apple-ios");  return true;
            case 8: arch.SetTriple ("thumbv4t-apple-ios"); return true;
            case 9: arch.SetTriple ("thumb-apple-ios");    return true;
            default: break;
        }
        break;

    case ArchSpec::eCore_arm_armv6:
        switch (idx)
        {
            case 0: arch.SetTriple ("armv6-apple-ios");    return true;
            case 1: arch.SetTriple ("armv5-apple-ios");    return true;
            case 2: arch.SetTriple ("armv4-apple-ios");    return true;
            case 3: arch.SetTriple ("arm-apple-ios");      return true;
            case 4: arch.SetTriple ("thumbv6-apple-ios");  return true;
            case 5: arch.SetTriple ("thumbv5-apple-ios");  return true;
            case 6: arch.SetTriple ("thumbv4t-apple-ios"); return true;
            case 7: arch.SetTriple ("thumb-apple-ios");    return true;
            default: break;
        }
        break;

    case ArchSpec::eCore_arm_armv5:
        switch (idx)
        {
            case 0: arch.SetTriple ("armv5-apple-ios");    return true;
            case 1: arch.SetTriple ("armv4-apple-ios");    return true;
            case 2: arch.SetTriple ("arm-apple-ios");      return true;
            case 3: arch.SetTriple ("thumbv5-apple-ios");  return true;
            case 4: arch.SetTriple ("thumbv4t-apple-ios"); return true;
            case 5: arch.SetTriple ("thumb-apple-ios");    return true;
            default: break;
        }
        break;

    case ArchSpec::eCore_arm_armv4:
        switch (idx)
        {
            case 0: arch.SetTriple ("armv4-apple-ios");    return true;
            case 1: arch.SetTriple ("arm-apple-ios");      return true;
            case 2: arch.SetTriple ("thumbv4t-apple-ios"); return true;
            case 3: arch.SetTriple ("thumb-apple-ios");    return true;
            default: break;
        }
        break;
    }
    arch.Clear();
    return false;
}


const char *
PlatformDarwin::GetDeveloperDirectory()
{
    Mutex::Locker locker (m_mutex);
    if (m_developer_directory.empty())
    {
        bool developer_dir_path_valid = false;
        char developer_dir_path[PATH_MAX];
        FileSpec temp_file_spec;
        if (HostInfo::GetLLDBPath(ePathTypeLLDBShlibDir, temp_file_spec))
        {
            if (temp_file_spec.GetPath (developer_dir_path, sizeof(developer_dir_path)))
            {
                char *shared_frameworks = strstr (developer_dir_path, "/SharedFrameworks/LLDB.framework");
                if (shared_frameworks)
                {
                    ::snprintf (shared_frameworks, 
                                sizeof(developer_dir_path) - (shared_frameworks - developer_dir_path),
                                "/Developer");
                    developer_dir_path_valid = true;
                }
                else
                {
                    char *lib_priv_frameworks = strstr (developer_dir_path, "/Library/PrivateFrameworks/LLDB.framework");
                    if (lib_priv_frameworks)
                    {
                        *lib_priv_frameworks = '\0';
                        developer_dir_path_valid = true;
                    }
                }
            }
        }
        
        if (!developer_dir_path_valid)
        {
            std::string xcode_dir_path;
            const char *xcode_select_prefix_dir = getenv ("XCODE_SELECT_PREFIX_DIR");
            if (xcode_select_prefix_dir)
                xcode_dir_path.append (xcode_select_prefix_dir);
            xcode_dir_path.append ("/usr/share/xcode-select/xcode_dir_path");
            temp_file_spec.SetFile(xcode_dir_path.c_str(), false);
            size_t bytes_read = temp_file_spec.ReadFileContents(0, developer_dir_path, sizeof(developer_dir_path), NULL);
            if (bytes_read > 0)
            {
                developer_dir_path[bytes_read] = '\0';
                while (developer_dir_path[bytes_read-1] == '\r' ||
                       developer_dir_path[bytes_read-1] == '\n')
                    developer_dir_path[--bytes_read] = '\0';
                developer_dir_path_valid = true;
            }
        }
        
        if (!developer_dir_path_valid)
        {
            FileSpec xcode_select_cmd ("/usr/bin/xcode-select", false);
            if (xcode_select_cmd.Exists())
            {
                int exit_status = -1;
                int signo = -1;
                std::string command_output;
                Error error = Host::RunShellCommand ("/usr/bin/xcode-select --print-path", 
                                                     NULL,                                 // current working directory
                                                     &exit_status,
                                                     &signo,
                                                     &command_output,
                                                     2,                                     // short timeout
                                                     false);                                // don't run in a shell
                if (error.Success() && exit_status == 0 && !command_output.empty())
                {
                    const char *cmd_output_ptr = command_output.c_str();
                    developer_dir_path[sizeof (developer_dir_path) - 1] = '\0';
                    size_t i;
                    for (i = 0; i < sizeof (developer_dir_path) - 1; i++)
                    {
                        if (cmd_output_ptr[i] == '\r' || cmd_output_ptr[i] == '\n' || cmd_output_ptr[i] == '\0')
                            break;
                        developer_dir_path[i] = cmd_output_ptr[i];
                    }
                    developer_dir_path[i] = '\0';

                    FileSpec devel_dir (developer_dir_path, false);
                    if (devel_dir.Exists() && devel_dir.IsDirectory())
                    {
                        developer_dir_path_valid = true;
                    }
                }
            }
        }

        if (developer_dir_path_valid)
        {
            temp_file_spec.SetFile (developer_dir_path, false);
            if (temp_file_spec.Exists())
            {
                m_developer_directory.assign (developer_dir_path);
                return m_developer_directory.c_str();
            }
        }
        // Assign a single NULL character so we know we tried to find the device
        // support directory and we don't keep trying to find it over and over.
        m_developer_directory.assign (1, '\0');
    }
    
    // We should have put a single NULL character into m_developer_directory
    // or it should have a valid path if the code gets here
    assert (m_developer_directory.empty() == false);
    if (m_developer_directory[0])
        return m_developer_directory.c_str();
    return NULL;
}


BreakpointSP
PlatformDarwin::SetThreadCreationBreakpoint (Target &target)
{
    BreakpointSP bp_sp;
    static const char *g_bp_names[] =
    {
        "start_wqthread",
        "_pthread_wqthread",
        "_pthread_start",
    };

    static const char *g_bp_modules[] =
    {
        "libsystem_c.dylib",
        "libSystem.B.dylib"
    };

    FileSpecList bp_modules;
    for (size_t i = 0; i < llvm::array_lengthof(g_bp_modules); i++)
    {
        const char *bp_module = g_bp_modules[i];
        bp_modules.Append(FileSpec(bp_module, false));
    }

    bool internal = true;
    bool hardware = false;
    LazyBool skip_prologue = eLazyBoolNo;
    bp_sp = target.CreateBreakpoint (&bp_modules,
                                     NULL,
                                     g_bp_names,
                                     llvm::array_lengthof(g_bp_names),
                                     eFunctionNameTypeFull,
                                     skip_prologue,
                                     internal,
                                     hardware);
    bp_sp->SetBreakpointKind("thread-creation");

    return bp_sp;
}


int32_t
PlatformDarwin::GetResumeCountForLaunchInfo (ProcessLaunchInfo &launch_info)
{
    const FileSpec &shell = launch_info.GetShell();
    if (!shell)
        return 1;
        
    std::string shell_string = shell.GetPath();
    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, "sh") == 0)
    {
        // /bin/sh re-exec's itself as /bin/bash requiring another resume.
        // But it only does this if the COMMAND_MODE environment variable
        // is set to "legacy".
        const char **envp = launch_info.GetEnvironmentEntries().GetConstArgumentVector();
        if (envp != NULL)
        {
            for (int i = 0; envp[i] != NULL; i++)
            {
                if (strcmp (envp[i], "COMMAND_MODE=legacy" ) == 0)
                    return 2;
            }
        }
        return 1;
    }
    else if (strcmp (shell_name, "csh") == 0
            || strcmp (shell_name, "tcsh") == 0
            || strcmp (shell_name, "zsh") == 0)
    {
        // csh and tcsh always seem to re-exec themselves.
        return 2;
    }
    else
        return 1;
}

void
PlatformDarwin::CalculateTrapHandlerSymbolNames ()
{   
    m_trap_handlers.push_back (ConstString ("_sigtramp"));
}


static const char *const sdk_strings[] = {
    "MacOSX",
    "iPhoneSimulator",
    "iPhoneOS",
};

static FileSpec
GetXcodeContentsPath ()
{
    const char substr[] = ".app/Contents/";
    
    // First, try based on the current shlib's location
    
    {
        FileSpec fspec;
        
        if (HostInfo::GetLLDBPath (lldb::ePathTypeLLDBShlibDir, fspec))
        {
            std::string path_to_shlib = fspec.GetPath();
            size_t pos = path_to_shlib.rfind(substr);
            if (pos != std::string::npos)
            {
                path_to_shlib.erase(pos + strlen(substr));
                return FileSpec(path_to_shlib.c_str(), false);
            }
        }
    }
    
    // Fall back to using xcrun
    
    {
        int status = 0;
        int signo = 0;
        std::string output;
        const char *command = "xcrun -sdk macosx --show-sdk-path";
        lldb_private::Error error = Host::RunShellCommand (command,   // shell command to run
                                                           NULL,      // current working directory
                                                           &status,   // Put the exit status of the process in here
                                                           &signo,    // Put the signal that caused the process to exit in here
                                                           &output,   // Get the output from the command and place it in this string
                                                           3);        // Timeout in seconds to wait for shell program to finish
        if (status == 0 && !output.empty())
        {
            size_t first_non_newline = output.find_last_not_of("\r\n");
            if (first_non_newline != std::string::npos)
            {
                output.erase(first_non_newline+1);
            }
            
            size_t pos = output.rfind(substr);
            if (pos != std::string::npos)
            {
                output.erase(pos + strlen(substr));
                return FileSpec(output.c_str(), false);
            }
        }
    }
    
    return FileSpec();
}

bool
PlatformDarwin::SDKSupportsModules (SDKType sdk_type, uint32_t major, uint32_t minor, uint32_t micro)
{
    switch (sdk_type)
    {
        case SDKType::MacOSX:
            if (major > 10 || (major == 10 && minor >= 10))
                return true;
            break;
        case SDKType::iPhoneOS:
        case SDKType::iPhoneSimulator:
            if (major >= 8)
                return true;
            break;
    }
    
    return false;
}

bool
PlatformDarwin::SDKSupportsModules (SDKType desired_type, const FileSpec &sdk_path)
{
    ConstString last_path_component = sdk_path.GetLastPathComponent();
    
    if (last_path_component)
    {
        const llvm::StringRef sdk_name = last_path_component.GetStringRef();
        
        llvm::StringRef version_part;
        
        if (sdk_name.startswith(sdk_strings[(int)desired_type]))
        {
            version_part = sdk_name.drop_front(strlen(sdk_strings[(int)desired_type]));
        }
        else
        {
            return false;
        }
        
        const size_t major_dot_offset = version_part.find('.');
        if (major_dot_offset == llvm::StringRef::npos)
            return false;
        
        const llvm::StringRef major_version = version_part.slice(0, major_dot_offset);
        const llvm::StringRef minor_part = version_part.drop_front(major_dot_offset + 1);
        
        const size_t minor_dot_offset = minor_part.find('.');
        if (minor_dot_offset == llvm::StringRef::npos)
            return false;
        
        const llvm::StringRef minor_version = minor_part.slice(0, minor_dot_offset);
        
        unsigned int major = 0;
        unsigned int minor = 0;
        unsigned int micro = 0;
        
        if (major_version.getAsInteger(10, major))
            return false;
        
        if (minor_version.getAsInteger(10, minor))
            return false;
        
        return SDKSupportsModules(desired_type, major, minor, micro);
    }
    
    return false;
}

FileSpec::EnumerateDirectoryResult
PlatformDarwin::DirectoryEnumerator(void *baton,
                                    FileSpec::FileType file_type,
                                    const FileSpec &spec)
{
    SDKEnumeratorInfo *enumerator_info = static_cast<SDKEnumeratorInfo*>(baton);
    
    if (SDKSupportsModules(enumerator_info->sdk_type, spec))
    {
        enumerator_info->found_path = spec;
        return FileSpec::EnumerateDirectoryResult::eEnumerateDirectoryResultNext;
    }
    
    return FileSpec::EnumerateDirectoryResult::eEnumerateDirectoryResultNext;
}

FileSpec
PlatformDarwin::FindSDKInXcodeForModules (SDKType sdk_type,
                                          const FileSpec &sdks_spec)
{
    // Look inside Xcode for the required installed iOS SDK version
    
    if (!sdks_spec.IsDirectory())
        return FileSpec();
    
    const bool find_directories = true;
    const bool find_files = false;
    const bool find_other = true; // include symlinks
    
    SDKEnumeratorInfo enumerator_info;
    
    enumerator_info.sdk_type = sdk_type;
    
    FileSpec::EnumerateDirectory(sdks_spec.GetPath().c_str(),
                                 find_directories,
                                 find_files,
                                 find_other,
                                 DirectoryEnumerator,
                                 &enumerator_info);
    
    if (enumerator_info.found_path.IsDirectory())
        return enumerator_info.found_path;
    else
        return FileSpec();
}

FileSpec
PlatformDarwin::GetSDKDirectoryForModules (SDKType sdk_type)
{
    switch (sdk_type)
    {
        case SDKType::MacOSX:
        case SDKType::iPhoneSimulator:
        case SDKType::iPhoneOS:
            break;
    }
    
    FileSpec sdks_spec = GetXcodeContentsPath();
    sdks_spec.AppendPathComponent("Developer");
    sdks_spec.AppendPathComponent("Platforms");
    
    switch (sdk_type)
    {
        case SDKType::MacOSX:
            sdks_spec.AppendPathComponent("MacOSX.platform");
            break;
        case SDKType::iPhoneSimulator:
            sdks_spec.AppendPathComponent("iPhoneSimulator.platform");
            break;
        case SDKType::iPhoneOS:
            sdks_spec.AppendPathComponent("iPhoneOS.platform");
            break;
    }
    
    sdks_spec.AppendPathComponent("Developer");
    sdks_spec.AppendPathComponent("SDKs");
    
    if (sdk_type == SDKType::MacOSX)
    {
        uint32_t major = 0;
        uint32_t minor = 0;
        uint32_t micro = 0;
        
        if (HostInfo::GetOSVersion(major, minor, micro))
        {
            if (SDKSupportsModules(SDKType::MacOSX, major, minor, micro))
            {
                // We slightly prefer the exact SDK for this machine.  See if it is there.
                
                FileSpec native_sdk_spec = sdks_spec;
                StreamString native_sdk_name;
                native_sdk_name.Printf("MacOSX%u.%u.sdk", major, minor);
                native_sdk_spec.AppendPathComponent(native_sdk_name.GetString().c_str());
                
                if (native_sdk_spec.Exists())
                {
                    return native_sdk_spec;
                }
            }
        }
    }
    
    return FindSDKInXcodeForModules(sdk_type, sdks_spec);
}

void
PlatformDarwin::AddClangModuleCompilationOptionsForSDKType (Target *target, std::vector<std::string> &options, SDKType sdk_type)
{
    const std::vector<std::string> apple_arguments =
    {
        "-x", "objective-c++",
        "-fobjc-arc",
        "-fblocks",
        "-D_ISO646_H",
        "-D__ISO646_H"
    };
    
    options.insert(options.end(),
                   apple_arguments.begin(),
                   apple_arguments.end());
    
    StreamString minimum_version_option;
    uint32_t versions[3] = { 0, 0, 0 };
    bool use_current_os_version = false;
    switch (sdk_type)
    {
        case SDKType::iPhoneOS:
#if defined (__arm__) || defined (__arm64__) || defined (__aarch64__)
            use_current_os_version = true;
#else
            use_current_os_version = false;
#endif
            break;

        case SDKType::iPhoneSimulator:
            use_current_os_version = false;
            break;

        case SDKType::MacOSX:
#if defined (__i386__) || defined (__x86_64__)
            use_current_os_version = true;
#else
            use_current_os_version = false;
#endif
            break;
    }

    bool versions_valid = false;
    if (use_current_os_version)
        versions_valid = GetOSVersion(versions[0], versions[1], versions[2]);
    else if (target)
    {
        // Our OS doesn't match our executable so we need to get the min OS version from the object file
        ModuleSP exe_module_sp = target->GetExecutableModule();
        if (exe_module_sp)
        {
            ObjectFile *object_file = exe_module_sp->GetObjectFile();
            if (object_file)
                versions_valid = object_file->GetMinimumOSVersion(versions, 3) > 0;
        }
    }
    // Only add the version-min options if we got a version from somewhere
    if (versions_valid && versions[0] != UINT32_MAX)
    {
        // Make any invalid versions be zero if needed
        if (versions[1] == UINT32_MAX)
            versions[1] = 0;
        if (versions[2] == UINT32_MAX)
            versions[2] = 0;
        
        switch (sdk_type)
        {
        case SDKType::iPhoneOS:
            minimum_version_option.PutCString("-mios-version-min=");
            minimum_version_option.PutCString(clang::VersionTuple(versions[0], versions[1], versions[2]).getAsString().c_str());
            break;
        case SDKType::iPhoneSimulator:
            minimum_version_option.PutCString("-mios-simulator-version-min=");
            minimum_version_option.PutCString(clang::VersionTuple(versions[0], versions[1], versions[2]).getAsString().c_str());
            break;
        case SDKType::MacOSX:
            minimum_version_option.PutCString("-mmacosx-version-min=");
            minimum_version_option.PutCString(clang::VersionTuple(versions[0], versions[1], versions[2]).getAsString().c_str());
        }
        options.push_back(minimum_version_option.GetString());
    }

    FileSpec sysroot_spec;
    // Scope for mutex locker below
    {
        Mutex::Locker locker (m_mutex);
        sysroot_spec = GetSDKDirectoryForModules(sdk_type);
    }
    
    if (sysroot_spec.IsDirectory())
    {
        options.push_back("-isysroot");
        options.push_back(sysroot_spec.GetPath());
    }
}
