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src/dyld.cpp dyld-45.1 dyld-635.2
--- dyld/dyld-45.1/src/dyld.cpp
+++ dyld/dyld-635.2/src/dyld.cpp
@@ -1,6 +1,6 @@
 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
  *
- * Copyright (c) 2004-2006 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2004-2013 Apple Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
@@ -25,42 +25,189 @@
 #include <stdint.h>
 #include <string.h>
 #include <unistd.h>
+#include <errno.h>
 #include <fcntl.h>
+#include <dirent.h>
+#include <pthread.h>
+#include <libproc.h>
 #include <sys/param.h>
 #include <mach/mach_time.h> // mach_absolute_time()
+#include <mach/mach_init.h> 
 #include <sys/types.h>
 #include <sys/stat.h> 
-#include <mach-o/fat.h> 
+#include <sys/syscall.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/syslog.h>
+#include <sys/uio.h>
+#include <mach/mach.h>
+#include <mach-o/fat.h>
 #include <mach-o/loader.h> 
+#include <mach-o/ldsyms.h> 
 #include <libkern/OSByteOrder.h> 
+#include <libkern/OSAtomic.h>
 #include <mach/mach.h>
 #include <sys/sysctl.h>
-
+#include <sys/mman.h>
+#include <sys/dtrace.h>
+#include <libkern/OSAtomic.h>
+#include <Availability.h>
+#include <System/sys/codesign.h>
+#include <System/sys/csr.h>
+#include <_simple.h>
+#include <os/lock_private.h>
+#include <System/machine/cpu_capabilities.h>
+#include <System/sys/reason.h>
+#include <kern/kcdata.h>
+#if TARGET_IPHONE_SIMULATOR
+	enum {
+		AMFI_DYLD_INPUT_PROC_IN_SIMULATOR = (1 << 0),
+	};
+	enum amfi_dyld_policy_output_flag_set {
+		AMFI_DYLD_OUTPUT_ALLOW_AT_PATH = (1 << 0),
+		AMFI_DYLD_OUTPUT_ALLOW_PATH_VARS = (1 << 1),
+		AMFI_DYLD_OUTPUT_ALLOW_CUSTOM_SHARED_CACHE = (1 << 2),
+		AMFI_DYLD_OUTPUT_ALLOW_FALLBACK_PATHS = (1 << 3),
+		AMFI_DYLD_OUTPUT_ALLOW_PRINT_VARS = (1 << 4),
+		AMFI_DYLD_OUTPUT_ALLOW_FAILED_LIBRARY_INSERTION = (1 << 5),
+	};
+	extern "C" int amfi_check_dyld_policy_self(uint64_t input_flags, uint64_t* output_flags);
+#else
+	#include <libamfi.h>
+#endif
+extern "C" {
+	#include <corecrypto/ccdigest.h>
+	#include <corecrypto/ccsha2.h>
+}
+#include <sandbox.h>
+#include <sandbox/private.h>
+#if __has_feature(ptrauth_calls)
+	#include <ptrauth.h>
+#endif
+
+extern "C" int __fork();
+
+#include <array>
+#include <algorithm>
 #include <vector>
+
+#ifndef CPU_SUBTYPE_ARM_V5TEJ
+	#define CPU_SUBTYPE_ARM_V5TEJ		((cpu_subtype_t) 7)
+#endif
+#ifndef CPU_SUBTYPE_ARM_XSCALE
+	#define CPU_SUBTYPE_ARM_XSCALE		((cpu_subtype_t) 8)
+#endif
+#ifndef CPU_SUBTYPE_ARM_V7
+	#define CPU_SUBTYPE_ARM_V7			((cpu_subtype_t) 9)
+#endif
+#ifndef CPU_SUBTYPE_ARM_V7F
+	#define CPU_SUBTYPE_ARM_V7F			((cpu_subtype_t) 10)
+#endif
+#ifndef CPU_SUBTYPE_ARM_V7S
+	#define CPU_SUBTYPE_ARM_V7S			((cpu_subtype_t) 11)
+#endif
+#ifndef CPU_SUBTYPE_ARM_V7K
+	#define CPU_SUBTYPE_ARM_V7K			((cpu_subtype_t) 12)
+#endif
+#ifndef LC_DYLD_ENVIRONMENT
+	#define LC_DYLD_ENVIRONMENT			0x27
+#endif
+
+#ifndef CPU_SUBTYPE_X86_64_H
+	#define CPU_SUBTYPE_X86_64_H		((cpu_subtype_t) 8) 
+#endif	
+
+#ifndef CPU_SUBTYPE_ARM64_E
+	#define CPU_SUBTYPE_ARM64_E    2
+#endif
+
+#ifndef CPU_ARCH_ABI64_32
+       #define CPU_ARCH_ABI64_32                               ((cpu_type_t) 0x02000000)
+#endif
+#ifndef CPU_TYPE_ARM64_32
+       #define CPU_TYPE_ARM64_32                               ((cpu_type_t) (CPU_TYPE_ARM | CPU_ARCH_ABI64_32))
+#endif
+#ifndef CPU_SUBTYPE_ARM64_32_V8
+       #define CPU_SUBTYPE_ARM64_32_V8         ((cpu_subtype_t) 1)
+#endif
+
+#ifndef VM_PROT_SLIDE   
+    #define VM_PROT_SLIDE 0x20
+#endif
 
 #include "mach-o/dyld_gdb.h"
 
 #include "dyld.h"
 #include "ImageLoader.h"
 #include "ImageLoaderMachO.h"
-#include "dyldLibSystemThreadHelpers.h"
+#include "dyldLibSystemInterface.h"
+#include "dyld_cache_format.h"
+#include "dyld_process_info_internal.h"
+
+#if SUPPORT_ACCELERATE_TABLES
+	#include "ImageLoaderMegaDylib.h"
+#endif
+
+#if TARGET_IPHONE_SIMULATOR
+	extern "C" void* gSyscallHelpers;
+#else
+	#include "dyldSyscallInterface.h"
+#endif
+
+#include "Closure.h"
+#include "libdyldEntryVector.h"
+#include "MachOLoaded.h"
+#include "Loading.h"
+#include "DyldSharedCache.h"
+#include "SharedCacheRuntime.h"
+#include "StringUtils.h"
+#include "Tracing.h"
+#include "ClosureBuilder.h"
+#include "ClosureFileSystemPhysical.h"
+#include "FileUtils.h"
+
+
+// not libc header for send() syscall interface
+extern "C" ssize_t __sendto(int, const void *, size_t, int, const struct sockaddr *, socklen_t);
+
+
+// ARM and x86_64 are the only architecture that use cpu-sub-types
+#define CPU_SUBTYPES_SUPPORTED  ((__arm__ || __arm64__ || __x86_64__) && !TARGET_IPHONE_SIMULATOR)
+
+#if __LP64__
+	#define LC_SEGMENT_COMMAND		LC_SEGMENT_64
+	#define LC_SEGMENT_COMMAND_WRONG LC_SEGMENT
+	#define LC_ENCRYPT_COMMAND		LC_ENCRYPTION_INFO
+	#define macho_segment_command	segment_command_64
+	#define macho_section			section_64
+#else
+	#define LC_SEGMENT_COMMAND		LC_SEGMENT
+	#define LC_SEGMENT_COMMAND_WRONG LC_SEGMENT_64
+	#define LC_ENCRYPT_COMMAND		LC_ENCRYPTION_INFO_64
+	#define macho_segment_command	segment_command
+	#define macho_section			section
+#endif
+
 
 
 #define CPU_TYPE_MASK 0x00FFFFFF	/* complement of CPU_ARCH_MASK */
 
 
 /* implemented in dyld_gdb.cpp */
-void addImagesToAllImages(uint32_t infoCount, const dyld_image_info info[]);
-void removeImageFromAllImages(const mach_header* mh);
-#if OLD_GDB_DYLD_INTERFACE
-void addImageForgdb(const mach_header* mh, uintptr_t slide, const char* physicalPath, const char* logicalPath);
-void removeImageForgdb(const struct mach_header* mh);
-#endif
+extern void resetAllImages();
+extern void addImagesToAllImages(uint32_t infoCount, const dyld_image_info info[]);
+extern void removeImageFromAllImages(const mach_header* mh);
+extern void addNonSharedCacheImageUUID(const dyld_uuid_info& info);
+extern const char* notifyGDB(enum dyld_image_states state, uint32_t infoCount, const dyld_image_info info[]);
+extern size_t allImagesCount();
 
 // magic so CrashReporter logs message
 extern "C" {
 	char error_string[1024];
 }
+
+// magic linker symbol for start of dyld binary
+extern "C" const macho_header __dso_handle;
 
 
 //
@@ -71,7 +218,19 @@
 //
 //
 //
-
+namespace dyld {
+	struct RegisteredDOF { const mach_header* mh; int registrationID; };
+	struct DylibOverride { const char* installName; const char* override; };
+}
+
+
+VECTOR_NEVER_DESTRUCTED(ImageLoader*);
+VECTOR_NEVER_DESTRUCTED(dyld::RegisteredDOF);
+VECTOR_NEVER_DESTRUCTED(dyld::ImageCallback);
+VECTOR_NEVER_DESTRUCTED(dyld::DylibOverride);
+VECTOR_NEVER_DESTRUCTED(ImageLoader::DynamicReference);
+
+VECTOR_NEVER_DESTRUCTED(dyld_image_state_change_handler);
 
 namespace dyld {
 
@@ -84,15 +243,19 @@
 	const char* const *			DYLD_FALLBACK_FRAMEWORK_PATH;
 	const char* const *			DYLD_LIBRARY_PATH;
 	const char* const *			DYLD_FALLBACK_LIBRARY_PATH;
-	const char*	const *			DYLD_ROOT_PATH;
 	const char* const *			DYLD_INSERT_LIBRARIES;
 	const char* const *			LD_LIBRARY_PATH;			// for unix conformance
-	bool						DYLD_PRINT_LIBRARIES;
+	const char* const *			DYLD_VERSIONED_LIBRARY_PATH;
+	const char* const *			DYLD_VERSIONED_FRAMEWORK_PATH;
 	bool						DYLD_PRINT_LIBRARIES_POST_LAUNCH;
 	bool						DYLD_BIND_AT_LAUNCH;
 	bool						DYLD_PRINT_STATISTICS;
+	bool						DYLD_PRINT_STATISTICS_DETAILS;
 	bool						DYLD_PRINT_OPTS;
 	bool						DYLD_PRINT_ENV;
+	bool						DYLD_DISABLE_DOFS;
+                            //  DYLD_SHARED_CACHE_DIR           ==> sSharedCacheOverrideDir
+							//	DYLD_ROOT_PATH					==> gLinkContext.rootPaths
 							//	DYLD_IMAGE_SUFFIX				==> gLinkContext.imageSuffix
 							//	DYLD_PRINT_OPTS					==> gLinkContext.verboseOpts
 							//	DYLD_PRINT_ENV					==> gLinkContext.verboseEnv
@@ -100,40 +263,354 @@
 							//	DYLD_PRINT_INITIALIZERS			==> gLinkContext.verboseInit
 							//	DYLD_PRINT_SEGMENTS				==> gLinkContext.verboseMapping
 							//	DYLD_PRINT_BINDINGS				==> gLinkContext.verboseBind
+							//  DYLD_PRINT_WEAK_BINDINGS		==> gLinkContext.verboseWeakBind
 							//	DYLD_PRINT_REBASINGS			==> gLinkContext.verboseRebase
+							//	DYLD_PRINT_DOFS					==> gLinkContext.verboseDOF
 							//	DYLD_PRINT_APIS					==> gLogAPIs
 							//	DYLD_IGNORE_PREBINDING			==> gLinkContext.prebindUsage
 							//	DYLD_PREBIND_DEBUG				==> gLinkContext.verbosePrebinding
 							//	DYLD_NEW_LOCAL_SHARED_REGIONS	==> gLinkContext.sharedRegionMode
 							//	DYLD_SHARED_REGION				==> gLinkContext.sharedRegionMode
-							//	DYLD_SLIDE_AND_PACK_DYLIBS		==> gLinkContext.slideAndPackDylibs
 							//	DYLD_PRINT_WARNINGS				==> gLinkContext.verboseWarnings
+							//	DYLD_PRINT_RPATHS				==> gLinkContext.verboseRPaths
+							//	DYLD_PRINT_INTERPOSING			==> gLinkContext.verboseInterposing
+							//  DYLD_PRINT_LIBRARIES			==> gLinkContext.verboseLoading
 };
 
+
+
+typedef std::vector<dyld_image_state_change_handler> StateHandlers;
+
+
+enum EnvVarMode { envNone, envPrintOnly, envAll };
+	
 // all global state
 static const char*					sExecPath = NULL;
-static const struct mach_header*	sMainExecutableMachHeader = NULL;
+static const char*					sExecShortName = NULL;
+static const macho_header*			sMainExecutableMachHeader = NULL;
+static uintptr_t					sMainExecutableSlide = 0;
+#if CPU_SUBTYPES_SUPPORTED
 static cpu_type_t					sHostCPU;
 static cpu_subtype_t				sHostCPUsubtype;
-static ImageLoader*					sMainExecutable = NULL;
-static bool							sAllImagesMightContainUnlinkedImages;	 // necessary until will support dylib unloading
+#endif
+static ImageLoaderMachO*			sMainExecutable = NULL;
+static size_t						sInsertedDylibCount = 0;
 static std::vector<ImageLoader*>	sAllImages;
 static std::vector<ImageLoader*>	sImageRoots;
 static std::vector<ImageLoader*>	sImageFilesNeedingTermination;
-static std::vector<ImageLoader*>	sImagesToNotifyAboutOtherImages;
+static std::vector<RegisteredDOF>	sImageFilesNeedingDOFUnregistration;
 static std::vector<ImageCallback>   sAddImageCallbacks;
 static std::vector<ImageCallback>   sRemoveImageCallbacks;
+static std::vector<LoadImageCallback> sAddLoadImageCallbacks;
+static bool							sRemoveImageCallbacksInUse = false;
+static void*						sSingleHandlers[7][3];
+static void*						sBatchHandlers[7][3];
 static ImageLoader*					sLastImageByAddressCache;
 static EnvironmentVariables			sEnv;
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
 static const char*					sFrameworkFallbackPaths[] = { "$HOME/Library/Frameworks", "/Library/Frameworks", "/Network/Library/Frameworks", "/System/Library/Frameworks", NULL };
 static const char*					sLibraryFallbackPaths[] = { "$HOME/lib", "/usr/local/lib", "/usr/lib", NULL };
-static BundleNotificationCallBack   sBundleNotifier = NULL;
-static BundleLocatorCallBack		sBundleLocation = NULL;
+static const char*					sRestrictedFrameworkFallbackPaths[] = { "/System/Library/Frameworks", NULL };
+static const char*					sRestrictedLibraryFallbackPaths[] = { "/usr/lib", NULL };
+#else
+static const char*					sFrameworkFallbackPaths[] = { "/System/Library/Frameworks", NULL };
+static const char*					sLibraryFallbackPaths[] = { "/usr/local/lib", "/usr/lib", NULL };
+#endif
 static UndefinedHandler				sUndefinedHandler = NULL;
+static ImageLoader*					sBundleBeingLoaded = NULL;	// hack until OFI is reworked
+static dyld3::SharedCacheLoadInfo	sSharedCacheLoadInfo;
+static const char*					sSharedCacheOverrideDir;
+       bool							gSharedCacheOverridden = false;
 ImageLoader::LinkContext			gLinkContext;
 bool								gLogAPIs = false;
-const struct ThreadingHelpers*		gThreadHelpers = NULL;
-
+#if SUPPORT_ACCELERATE_TABLES
+bool								gLogAppAPIs = false;
+#endif
+const struct LibSystemHelpers*		gLibSystemHelpers = NULL;
+#if SUPPORT_OLD_CRT_INITIALIZATION
+bool								gRunInitializersOldWay = false;
+#endif
+static std::vector<DylibOverride>	sDylibOverrides;
+#if !TARGET_IPHONE_SIMULATOR	
+static int							sLogSocket = -1;
+#endif
+static bool							sFrameworksFoundAsDylibs = false;
+#if __x86_64__ && !TARGET_IPHONE_SIMULATOR
+static bool							sHaswell = false;
+#endif
+static std::vector<ImageLoader::DynamicReference> sDynamicReferences;
+static OSSpinLock					sDynamicReferencesLock = 0;
+#if !TARGET_IPHONE_SIMULATOR
+static bool							sLogToFile = false;
+#endif
+static char							sLoadingCrashMessage[1024] = "dyld: launch, loading dependent libraries";
+static _dyld_objc_notify_mapped		sNotifyObjCMapped;
+static _dyld_objc_notify_init		sNotifyObjCInit;
+static _dyld_objc_notify_unmapped	sNotifyObjCUnmapped;
+
+#if __IPHONE_OS_VERSION_MIN_REQUIRED && !TARGET_IPHONE_SIMULATOR
+static bool							sForceStderr = false;
+#endif
+
+
+#if SUPPORT_ACCELERATE_TABLES
+static ImageLoaderMegaDylib*		sAllCacheImagesProxy = NULL;
+static bool							sDisableAcceleratorTables = false;
+#endif
+
+bool								gUseDyld3 = false;
+static bool							sSkipMain = false;
+static bool							sEnableClosures = false;
+static uint64_t						launchTraceID = 0;
+
+//
+// The MappedRanges structure is used for fast address->image lookups.
+// The table is only updated when the dyld lock is held, so we don't
+// need to worry about multiple writers.  But readers may look at this
+// data without holding the lock. Therefore, all updates must be done
+// in an order that will never cause readers to see inconsistent data.
+// The general rule is that if the image field is non-NULL then
+// the other fields are valid.
+//
+struct MappedRanges
+{
+	MappedRanges*		next;
+	unsigned long		count;
+	struct {
+		ImageLoader*	image;
+		uintptr_t		start;
+		uintptr_t		end;
+	} array[1];
+};
+
+static MappedRanges*	sMappedRangesStart;
+
+void addMappedRange(ImageLoader* image, uintptr_t start, uintptr_t end)
+{
+	//dyld::log("addMappedRange(0x%lX->0x%lX) for %s\n", start, end, image->getShortName());
+	for (MappedRanges* p = sMappedRangesStart; p != NULL; p = p->next) {
+		for (unsigned long i=0; i < p->count; ++i) {
+			if ( p->array[i].image == NULL ) {
+				p->array[i].start = start;
+				p->array[i].end = end;
+				// add image field last with a barrier so that any reader will see consistent records
+				OSMemoryBarrier();
+				p->array[i].image = image;
+				return;
+			}
+		}
+	}
+	// table must be full, chain another
+#if SUPPORT_ACCELERATE_TABLES
+	unsigned count = (sAllCacheImagesProxy != NULL) ? 16 : 400;
+#else
+	unsigned count = 400;
+#endif
+	size_t allocationSize = sizeof(MappedRanges) + (count-1)*3*sizeof(void*);
+	MappedRanges* newRanges = (MappedRanges*)malloc(allocationSize);
+	bzero(newRanges, allocationSize);
+	newRanges->count = count;
+	newRanges->array[0].start = start;
+	newRanges->array[0].end = end;
+	newRanges->array[0].image = image;
+	OSMemoryBarrier();
+	if ( sMappedRangesStart == NULL ) {
+		sMappedRangesStart = newRanges;
+	}
+	else {
+		for (MappedRanges* p = sMappedRangesStart; p != NULL; p = p->next) {
+			if ( p->next == NULL ) {
+				OSMemoryBarrier();
+				p->next = newRanges;
+				break;
+			}
+		}
+	}
+}
+
+void removedMappedRanges(ImageLoader* image)
+{
+	for (MappedRanges* p = sMappedRangesStart; p != NULL; p = p->next) {
+		for (unsigned long i=0; i < p->count; ++i) {
+			if ( p->array[i].image == image ) {
+				// clear with a barrier so that any reader will see consistent records
+				OSMemoryBarrier();
+				p->array[i].image = NULL;
+			}
+		}
+	}
+}
+
+ImageLoader* findMappedRange(uintptr_t target)
+{
+	for (MappedRanges* p = sMappedRangesStart; p != NULL; p = p->next) {
+		for (unsigned long i=0; i < p->count; ++i) {
+			if ( p->array[i].image != NULL ) {
+				if ( (p->array[i].start <= target) && (target < p->array[i].end) )
+					return p->array[i].image;
+			}
+		}
+	}
+	return NULL;
+}
+
+
+
+const char* mkstringf(const char* format, ...)
+{
+	_SIMPLE_STRING buf = _simple_salloc();
+	if ( buf != NULL ) {
+		va_list	list;
+		va_start(list, format);
+		_simple_vsprintf(buf, format, list);
+		va_end(list);
+		const char*	t = strdup(_simple_string(buf));
+		_simple_sfree(buf);
+		if ( t != NULL )
+			return t;
+	}
+	return "mkstringf, out of memory error";
+}
+
+
+void throwf(const char* format, ...) 
+{
+	_SIMPLE_STRING buf = _simple_salloc();
+	if ( buf != NULL ) {
+		va_list	list;
+		va_start(list, format);
+		_simple_vsprintf(buf, format, list);
+		va_end(list);
+		const char*	t = strdup(_simple_string(buf));
+		_simple_sfree(buf);
+		if ( t != NULL )
+			throw t;
+	}
+	throw "throwf, out of memory error";
+}
+
+
+#if !TARGET_IPHONE_SIMULATOR
+static int sLogfile = STDERR_FILENO;
+#endif
+
+#if !TARGET_IPHONE_SIMULATOR	
+// based on CFUtilities.c: also_do_stderr()
+static bool useSyslog()
+{
+	// Use syslog() for processes managed by launchd
+	static bool launchdChecked = false;
+	static bool launchdOwned = false;
+	if ( !launchdChecked && gProcessInfo->libSystemInitialized ) {
+		if ( (gLibSystemHelpers != NULL) && (gLibSystemHelpers->version >= 11) ) {
+			// <rdar://problem/23520449> only call isLaunchdOwned() after libSystem is initialized
+			launchdOwned = (*gLibSystemHelpers->isLaunchdOwned)();
+			launchdChecked = true;
+		}
+	}
+	if ( launchdChecked && launchdOwned )
+		return true;
+
+	// If stderr is not available, use syslog()
+	struct stat sb;
+	int result = fstat(STDERR_FILENO, &sb);
+	if ( result < 0 )
+		return true; // file descriptor 2 is closed
+
+	return false;
+}
+
+	
+static void socket_syslogv(int priority, const char* format, va_list list)
+{
+	// lazily create socket and connection to syslogd
+	if ( sLogSocket == -1 ) {
+		sLogSocket = ::socket(AF_UNIX, SOCK_DGRAM, 0);
+		if (sLogSocket == -1)
+			return;  // cannot log
+		::fcntl(sLogSocket, F_SETFD, 1);
+	
+		struct sockaddr_un addr;
+		addr.sun_family = AF_UNIX;
+		strncpy(addr.sun_path, _PATH_LOG, sizeof(addr.sun_path));
+		if ( ::connect(sLogSocket, (struct sockaddr *)&addr, sizeof(addr)) == -1 ) {
+			::close(sLogSocket);
+			sLogSocket = -1;
+			return;
+		}
+	}
+	
+	// format message to syslogd like: "<priority>Process[pid]: message"
+	_SIMPLE_STRING buf = _simple_salloc();
+	if ( buf == NULL )
+		return;
+	if ( _simple_sprintf(buf, "<%d>%s[%d]: ", LOG_USER|LOG_NOTICE, sExecShortName, getpid()) == 0 ) {
+		if ( _simple_vsprintf(buf, format, list) == 0 ) {
+			const char* p = _simple_string(buf);
+			::__sendto(sLogSocket, p, strlen(p), 0, NULL, 0);
+		}
+	}
+	_simple_sfree(buf);
+}
+
+
+
+void vlog(const char* format, va_list list)
+{
+#if __IPHONE_OS_VERSION_MIN_REQUIRED && !TARGET_IPHONE_SIMULATOR
+	// <rdar://problem/25965832> log to console when running iOS app from Xcode
+	if ( !sLogToFile && !sForceStderr && useSyslog() )
+#else
+	if ( !sLogToFile && useSyslog() )
+#endif
+		socket_syslogv(LOG_ERR, format, list);
+	else {
+		_simple_vdprintf(sLogfile, format, list);
+	}
+}
+
+void log(const char* format, ...)
+{
+	va_list	list;
+	va_start(list, format);
+	vlog(format, list);
+	va_end(list);
+}
+
+
+void vwarn(const char* format, va_list list) 
+{
+	_simple_dprintf(sLogfile, "dyld: warning, ");
+	_simple_vdprintf(sLogfile, format, list);
+}
+
+void warn(const char* format, ...) 
+{
+	va_list	list;
+	va_start(list, format);
+	vwarn(format, list);
+	va_end(list);
+}
+
+#else
+	extern void vlog(const char* format, va_list list);
+#endif // !TARGET_IPHONE_SIMULATOR	
+
+
+// <rdar://problem/8867781> control access to sAllImages through a lock 
+// because global dyld lock is not held during initialization phase of dlopen()
+// <rdar://problem/16145518> Use OSSpinLockLock to allow yielding
+static OSSpinLock sAllImagesLock = 0;
+
+static void allImagesLock()
+{
+	OSSpinLockLock(&sAllImagesLock);
+}
+
+static void allImagesUnlock()
+{
+	OSSpinLockUnlock(&sAllImagesLock);
+}
 
 
 // utility class to assure files are closed when an exception is thrown
@@ -147,60 +624,542 @@
 };
 
 FileOpener::FileOpener(const char* path)
-{
-	fd = open(path, O_RDONLY, 0);
+ : fd(-1)
+{
+	fd = my_open(path, O_RDONLY, 0);
 }
 
 FileOpener::~FileOpener()
 {
-	close(fd);
-}
-
-
-
-// Objective-C installs an addImage hook to dyld to get notified about new images
-// The callback needs to be run after the image is rebased and bound, but before its initializers are called
-static uint32_t imageNotification(ImageLoader* image, uint32_t startIndex)
-{
-	// tell all register add image handlers about this
-	const uint32_t callbackCount = sAddImageCallbacks.size();
-	for (uint32_t i=startIndex; i < callbackCount; ++i) {
-		ImageCallback cb = sAddImageCallbacks[i];
-		//fprintf(stderr, "dyld: calling add-image-callback[%d]=%p for %s\n", i, cb, image->getPath());
-		(cb)(image->machHeader(), image->getSlide());
-	}
-	return callbackCount;
-}
-
-
-
-// notify gdb et al about these new images
-static void notifyAdding(std::vector<ImageLoader*>& images)
-{
-	// build array
-	unsigned int len = images.size();
-	if ( len != 0 ) {
-		dyld_image_info	infos[len];
-		for (unsigned int i=0; i < len; ++i) {
-			dyld_image_info* p = &infos[i];
-			ImageLoader* image = images[i];
-			p->imageLoadAddress = image->machHeader();
-			p->imageFilePath = image->getPath();
-			p->imageFileModDate = image->lastModified();
-			//fprintf(stderr, "notifying objc about %s\n", image->getPath());
-		}
-		
-		// tell gdb
-		addImagesToAllImages(len, infos);
-				
-		// tell all interested images (after gdb, so you can debug anything the notification does)
-		for (std::vector<ImageLoader*>::iterator it=sImagesToNotifyAboutOtherImages.begin(); it != sImagesToNotifyAboutOtherImages.end(); it++) {
-			(*it)->doNotification(dyld_image_adding, len, infos);
-		}
-	}
-}
-
-
+	if ( fd != -1 )
+		close(fd);
+}
+
+
+static void	registerDOFs(const std::vector<ImageLoader::DOFInfo>& dofs)
+{
+	const size_t dofSectionCount = dofs.size();
+	if ( !sEnv.DYLD_DISABLE_DOFS && (dofSectionCount != 0) ) {
+		int fd = open("/dev/" DTRACEMNR_HELPER, O_RDWR);
+		if ( fd < 0 ) {
+			//dyld::warn("can't open /dev/" DTRACEMNR_HELPER " to register dtrace DOF sections\n");
+		}
+		else {
+			// allocate a buffer on the stack for the variable length dof_ioctl_data_t type
+			uint8_t buffer[sizeof(dof_ioctl_data_t) + dofSectionCount*sizeof(dof_helper_t)];
+			dof_ioctl_data_t* ioctlData = (dof_ioctl_data_t*)buffer;
+			
+			// fill in buffer with one dof_helper_t per DOF section
+			ioctlData->dofiod_count = dofSectionCount;
+			for (unsigned int i=0; i < dofSectionCount; ++i) {
+				strlcpy(ioctlData->dofiod_helpers[i].dofhp_mod, dofs[i].imageShortName, DTRACE_MODNAMELEN);
+				ioctlData->dofiod_helpers[i].dofhp_dof = (uintptr_t)(dofs[i].dof);
+				ioctlData->dofiod_helpers[i].dofhp_addr = (uintptr_t)(dofs[i].dof);
+			}
+			
+			// tell kernel about all DOF sections en mas
+			// pass pointer to ioctlData because ioctl() only copies a fixed size amount of data into kernel
+			user_addr_t val = (user_addr_t)(unsigned long)ioctlData;
+			if ( ioctl(fd, DTRACEHIOC_ADDDOF, &val) != -1 ) {
+				// kernel returns a unique identifier for each section in the dofiod_helpers[].dofhp_dof field.
+				for (unsigned int i=0; i < dofSectionCount; ++i) {
+					RegisteredDOF info;
+					info.mh = dofs[i].imageHeader;
+					info.registrationID = (int)(ioctlData->dofiod_helpers[i].dofhp_dof);
+					sImageFilesNeedingDOFUnregistration.push_back(info);
+					if ( gLinkContext.verboseDOF ) {
+						dyld::log("dyld: registering DOF section %p in %s with dtrace, ID=0x%08X\n", 
+							dofs[i].dof, dofs[i].imageShortName, info.registrationID);
+					}
+				}
+			}
+			else {
+				//dyld::log( "dyld: ioctl to register dtrace DOF section failed\n");
+			}
+			close(fd);
+		}
+	}
+}
+
+static void	unregisterDOF(int registrationID)
+{
+	int fd = open("/dev/" DTRACEMNR_HELPER, O_RDWR);
+	if ( fd < 0 ) {
+		dyld::warn("can't open /dev/" DTRACEMNR_HELPER " to unregister dtrace DOF section\n");
+	}
+	else {
+		ioctl(fd, DTRACEHIOC_REMOVE, registrationID);
+		close(fd);
+		if ( gLinkContext.verboseInit )
+			dyld::warn("unregistering DOF section ID=0x%08X with dtrace\n", registrationID);
+	}
+}
+
+
+//
+// _dyld_register_func_for_add_image() is implemented as part of the general image state change notification
+//
+static void notifyAddImageCallbacks(ImageLoader* image)
+{
+	// use guard so that we cannot notify about the same image twice
+	if ( ! image->addFuncNotified() ) {
+		for (std::vector<ImageCallback>::iterator it=sAddImageCallbacks.begin(); it != sAddImageCallbacks.end(); it++) {
+			dyld3::ScopedTimer timer(DBG_DYLD_TIMING_FUNC_FOR_ADD_IMAGE, (uint64_t)image->machHeader(), (uint64_t)(*it), 0);
+			(*it)(image->machHeader(), image->getSlide());
+		}
+		for (LoadImageCallback func : sAddLoadImageCallbacks) {
+			dyld3::ScopedTimer timer(DBG_DYLD_TIMING_FUNC_FOR_ADD_IMAGE, (uint64_t)image->machHeader(), (uint64_t)(*func), 0);
+			(*func)(image->machHeader(), image->getPath(), !image->neverUnload());
+		}
+		image->setAddFuncNotified();
+	}
+}
+
+
+
+// notify gdb about these new images
+static const char* updateAllImages(enum dyld_image_states state, uint32_t infoCount, const struct dyld_image_info info[])
+{
+	// <rdar://problem/8812589> don't add images without paths to all-image-info-list
+	if ( info[0].imageFilePath != NULL )
+		addImagesToAllImages(infoCount, info);
+	return NULL;
+}
+
+
+static StateHandlers* stateToHandlers(dyld_image_states state, void* handlersArray[7][3])
+{
+	switch ( state ) {
+		case dyld_image_state_mapped:
+			return reinterpret_cast<StateHandlers*>(&handlersArray[0]);
+			
+		case dyld_image_state_dependents_mapped:
+			return reinterpret_cast<StateHandlers*>(&handlersArray[1]);
+			
+		case dyld_image_state_rebased:
+			return reinterpret_cast<StateHandlers*>(&handlersArray[2]);
+			
+		case dyld_image_state_bound:
+			return reinterpret_cast<StateHandlers*>(&handlersArray[3]);
+			
+		case dyld_image_state_dependents_initialized:
+			return reinterpret_cast<StateHandlers*>(&handlersArray[4]);
+
+		case dyld_image_state_initialized:
+			return reinterpret_cast<StateHandlers*>(&handlersArray[5]);
+			
+		case dyld_image_state_terminated:
+			return reinterpret_cast<StateHandlers*>(&handlersArray[6]);
+	}
+	return NULL;
+}
+
+#if SUPPORT_ACCELERATE_TABLES
+static dyld_image_state_change_handler getPreInitNotifyHandler(unsigned index)
+{
+	std::vector<dyld_image_state_change_handler>* handlers = stateToHandlers(dyld_image_state_dependents_initialized, sSingleHandlers);
+	if ( index >= handlers->size() )
+		return NULL;
+	return (*handlers)[index];
+}
+
+static dyld_image_state_change_handler getBoundBatchHandler(unsigned index)
+{
+	std::vector<dyld_image_state_change_handler>* handlers = stateToHandlers(dyld_image_state_bound, sBatchHandlers);
+	if ( index >= handlers->size() )
+		return NULL;
+	return (*handlers)[index];
+}
+
+static void notifySingleFromCache(dyld_image_states state, const mach_header* mh, const char* path)
+{
+	//dyld::log("notifySingle(state=%d, image=%s)\n", state, image->getPath());
+	std::vector<dyld_image_state_change_handler>* handlers = stateToHandlers(state, sSingleHandlers);
+	if ( handlers != NULL ) {
+		dyld_image_info info;
+		info.imageLoadAddress	= mh;
+		info.imageFilePath		= path;
+		info.imageFileModDate	= 0;
+		for (dyld_image_state_change_handler handler : *handlers) {
+			const char* result = (*handler)(state, 1, &info);
+			if ( (result != NULL) && (state == dyld_image_state_mapped) ) {
+				//fprintf(stderr, "  image rejected by handler=%p\n", *it);
+				// make copy of thrown string so that later catch clauses can free it
+				const char* str = strdup(result);
+				throw str;
+			}
+		}
+	}
+	if ( (state == dyld_image_state_dependents_initialized) && (sNotifyObjCInit != NULL) && (mh->flags & MH_HAS_OBJC) ) {
+		dyld3::ScopedTimer timer(DBG_DYLD_TIMING_OBJC_INIT, (uint64_t)mh, 0, 0);
+		(*sNotifyObjCInit)(path, mh);
+	}
+}
+#endif
+
+#if !TARGET_OS_SIMULATOR
+static void sendMessage(unsigned portSlot, mach_msg_id_t msgId, mach_msg_size_t sendSize, mach_msg_header_t* buffer, mach_msg_size_t bufferSize) {
+	// Allocate a port to listen on in this monitoring task
+	mach_port_t sendPort = dyld::gProcessInfo->notifyPorts[portSlot];
+	if (sendPort == MACH_PORT_NULL) {
+		return;
+	}
+	mach_port_t replyPort = MACH_PORT_NULL;
+	mach_port_options_t options = { .flags = MPO_CONTEXT_AS_GUARD | MPO_STRICT,
+		.mpl = { 1 }};
+	kern_return_t kr = mach_port_construct(mach_task_self(), &options, (mach_port_context_t)&replyPort, &replyPort);
+	if (kr != KERN_SUCCESS) {
+		return;
+	}
+	// Assemble a message
+	mach_msg_header_t* h = buffer;
+	h->msgh_bits         = MACH_MSGH_BITS(MACH_MSG_TYPE_COPY_SEND,MACH_MSG_TYPE_MAKE_SEND_ONCE);
+	h->msgh_id           = msgId;
+	h->msgh_local_port   = replyPort;
+	h->msgh_remote_port  = sendPort;
+	h->msgh_reserved     = 0;
+	h->msgh_size         = sendSize;
+	kr = mach_msg(h, MACH_SEND_MSG | MACH_RCV_MSG, h->msgh_size, bufferSize, replyPort, 0, MACH_PORT_NULL);
+	mach_msg_destroy(h);
+	if ( kr == MACH_SEND_INVALID_DEST ) {
+		if (OSAtomicCompareAndSwap32(sendPort, 0, (volatile int32_t*)&dyld::gProcessInfo->notifyPorts[portSlot])) {
+			mach_port_deallocate(mach_task_self(), sendPort);
+		}
+	}
+	mach_port_destruct(mach_task_self(), replyPort, 0, (mach_port_context_t)&replyPort);
+}
+
+static void notifyMonitoringDyld(bool unloading, unsigned imageCount, const struct mach_header* loadAddresses[],
+								 const char* imagePaths[])
+{
+	dyld3::ScopedTimer(DBG_DYLD_REMOTE_IMAGE_NOTIFIER, 0, 0, 0);
+	for (int slot=0; slot < DYLD_MAX_PROCESS_INFO_NOTIFY_COUNT; ++slot) {
+		if ( dyld::gProcessInfo->notifyPorts[slot] == 0) continue;
+		unsigned entriesSize = imageCount*sizeof(dyld_process_info_image_entry);
+		unsigned pathsSize = 0;
+		for (unsigned j=0; j < imageCount; ++j) {
+			pathsSize += (strlen(imagePaths[j]) + 1);
+		}
+		unsigned totalSize = (sizeof(dyld_process_info_notify_header) + entriesSize + pathsSize + 127) & -128;   // align
+		if ( totalSize > DYLD_PROCESS_INFO_NOTIFY_MAX_BUFFER_SIZE ) {
+			// Putting all image paths into one message would make buffer too big.
+			// Instead split into two messages.  Recurse as needed until paths fit in buffer.
+			unsigned imageHalfCount = imageCount/2;
+			notifyMonitoringDyld(unloading, imageHalfCount, loadAddresses, imagePaths);
+			notifyMonitoringDyld(unloading, imageCount - imageHalfCount, &loadAddresses[imageHalfCount], &imagePaths[imageHalfCount]);
+			return;
+		}
+		uint8_t	buffer[totalSize + MAX_TRAILER_SIZE];
+		dyld_process_info_notify_header* header = (dyld_process_info_notify_header*)buffer;
+		header->version			= 1;
+		header->imageCount		= imageCount;
+		header->imagesOffset	= sizeof(dyld_process_info_notify_header);
+		header->stringsOffset	= sizeof(dyld_process_info_notify_header) + entriesSize;
+		header->timestamp		= dyld::gProcessInfo->infoArrayChangeTimestamp;
+		dyld_process_info_image_entry* entries = (dyld_process_info_image_entry*)&buffer[header->imagesOffset];
+		char* const pathPoolStart = (char*)&buffer[header->stringsOffset];
+		char* pathPool = pathPoolStart;
+		for (unsigned j=0; j < imageCount; ++j) {
+			strcpy(pathPool, imagePaths[j]);
+			uint32_t len = (uint32_t)strlen(pathPool);
+			bzero(entries->uuid, 16);
+			dyld3::MachOFile* mf = (dyld3::MachOFile*)loadAddresses[j];
+			mf->getUuid(entries->uuid);
+			entries->loadAddress = (uint64_t)loadAddresses[j];
+			entries->pathStringOffset = (uint32_t)(pathPool - pathPoolStart);
+			entries->pathLength  = len;
+			pathPool += (len +1);
+			++entries;
+		}
+		if (unloading) {
+			sendMessage(slot, DYLD_PROCESS_INFO_NOTIFY_UNLOAD_ID, totalSize, (mach_msg_header_t*)buffer, totalSize+MAX_TRAILER_SIZE);
+		} else {
+			sendMessage(slot, DYLD_PROCESS_INFO_NOTIFY_LOAD_ID, totalSize, (mach_msg_header_t*)buffer, totalSize+MAX_TRAILER_SIZE);
+		}
+	}
+}
+
+static void notifyMonitoringDyldMain()
+{
+	dyld3::ScopedTimer(DBG_DYLD_REMOTE_IMAGE_NOTIFIER, 0, 0, 0);
+	for (int slot=0; slot < DYLD_MAX_PROCESS_INFO_NOTIFY_COUNT; ++slot) {
+		if ( dyld::gProcessInfo->notifyPorts[slot] == 0) continue;
+		uint8_t buffer[sizeof(mach_msg_header_t) + MAX_TRAILER_SIZE];
+		sendMessage(slot, DYLD_PROCESS_INFO_NOTIFY_MAIN_ID, sizeof(mach_msg_header_t), (mach_msg_header_t*)buffer, sizeof(mach_msg_header_t) + MAX_TRAILER_SIZE);
+	}
+}
+#else
+extern void notifyMonitoringDyldMain() VIS_HIDDEN;
+extern void notifyMonitoringDyld(bool unloading, unsigned imageCount, const struct mach_header* loadAddresses[],
+								 const char* imagePaths[]) VIS_HIDDEN;
+#endif
+
+void notifyKernel(const ImageLoader& image, bool loading) {
+	if ( !image.inSharedCache() ) {
+		uint32_t baseCode = loading ? DBG_DYLD_UUID_MAP_A : DBG_DYLD_UUID_UNMAP_A;
+		uuid_t uuid;
+		ino_t inode = image.getInode();
+		image.getUUID(uuid);
+		dyld3::kdebug_trace_dyld_image(baseCode, (const uuid_t *)&uuid, *(fsobj_id_t*)&inode, {{ image.getDevice(), 0 }}, image.machHeader());
+	}
+}
+
+static void notifySingle(dyld_image_states state, const ImageLoader* image, ImageLoader::InitializerTimingList* timingInfo)
+{
+	//dyld::log("notifySingle(state=%d, image=%s)\n", state, image->getPath());
+	std::vector<dyld_image_state_change_handler>* handlers = stateToHandlers(state, sSingleHandlers);
+	if ( handlers != NULL ) {
+		dyld_image_info info;
+		info.imageLoadAddress	= image->machHeader();
+		info.imageFilePath		= image->getRealPath();
+		info.imageFileModDate	= image->lastModified();
+		for (std::vector<dyld_image_state_change_handler>::iterator it = handlers->begin(); it != handlers->end(); ++it) {
+			const char* result = (*it)(state, 1, &info);
+			if ( (result != NULL) && (state == dyld_image_state_mapped) ) {
+				//fprintf(stderr, "  image rejected by handler=%p\n", *it);
+				// make copy of thrown string so that later catch clauses can free it
+				const char* str = strdup(result);
+				throw str;
+			}
+		}
+	}
+	if ( state == dyld_image_state_mapped ) {
+		// <rdar://problem/7008875> Save load addr + UUID for images from outside the shared cache
+		if ( !image->inSharedCache() ) {
+			dyld_uuid_info info;
+			if ( image->getUUID(info.imageUUID) ) {
+				info.imageLoadAddress = image->machHeader();
+				addNonSharedCacheImageUUID(info);
+			}
+		}
+	}
+	if ( (state == dyld_image_state_dependents_initialized) && (sNotifyObjCInit != NULL) && image->notifyObjC() ) {
+		uint64_t t0 = mach_absolute_time();
+		dyld3::ScopedTimer timer(DBG_DYLD_TIMING_OBJC_INIT, (uint64_t)image->machHeader(), 0, 0);
+		(*sNotifyObjCInit)(image->getRealPath(), image->machHeader());
+		uint64_t t1 = mach_absolute_time();
+		uint64_t t2 = mach_absolute_time();
+		uint64_t timeInObjC = t1-t0;
+		uint64_t emptyTime = (t2-t1)*100;
+		if ( (timeInObjC > emptyTime) && (timingInfo != NULL) ) {
+			timingInfo->addTime(image->getShortName(), timeInObjC);
+		}
+	}
+    // mach message csdlc about dynamically unloaded images
+	if ( image->addFuncNotified() && (state == dyld_image_state_terminated) ) {
+		notifyKernel(*image, false);
+		const struct mach_header* loadAddress[] = { image->machHeader() };
+		const char* loadPath[] = { image->getPath() };
+		notifyMonitoringDyld(true, 1, loadAddress, loadPath);
+	}
+}
+
+
+//
+// Normally, dyld_all_image_infos is only updated in batches after an entire
+// graph is loaded.  But if there is an error loading the initial set of
+// dylibs needed by the main executable, dyld_all_image_infos is not yet set 
+// up, leading to usually brief crash logs.
+//
+// This function manually adds the images loaded so far to dyld::gProcessInfo.
+// It should only be called before terminating.
+//
+void syncAllImages()
+{
+	for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); ++it) {
+		dyld_image_info info;
+		ImageLoader* image = *it;
+		info.imageLoadAddress = image->machHeader();
+		info.imageFilePath = image->getRealPath();
+		info.imageFileModDate = image->lastModified();
+		// add to all_image_infos if not already there
+		bool found = false;
+		int existingCount = dyld::gProcessInfo->infoArrayCount;
+		const dyld_image_info* existing = dyld::gProcessInfo->infoArray;
+		if ( existing != NULL ) {
+			for (int i=0; i < existingCount; ++i) {
+				if ( existing[i].imageLoadAddress == info.imageLoadAddress ) {
+					//dyld::log("not adding %s\n", info.imageFilePath);
+					found = true;
+					break;
+				}
+			}
+		}
+		if ( ! found ) {
+			//dyld::log("adding %s\n", info.imageFilePath);
+			addImagesToAllImages(1, &info);
+		}
+	}
+}
+
+
+static int imageSorter(const void* l, const void* r)
+{
+	const ImageLoader* left = *((ImageLoader**)l);
+	const ImageLoader* right= *((ImageLoader**)r);
+	return left->compare(right);
+}
+
+static void notifyBatchPartial(dyld_image_states state, bool orLater, dyld_image_state_change_handler onlyHandler, bool preflightOnly, bool onlyObjCMappedNotification)
+{
+	std::vector<dyld_image_state_change_handler>* handlers = stateToHandlers(state, sBatchHandlers);
+	if ( (handlers != NULL) || ((state == dyld_image_state_bound) && (sNotifyObjCMapped != NULL)) ) {
+		// don't use a vector because it will use malloc/free and we want notifcation to be low cost
+        allImagesLock();
+		dyld_image_info	infos[allImagesCount()+1];
+        ImageLoader* images[allImagesCount()+1];
+        ImageLoader** end = images;
+        for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+            dyld_image_states imageState = (*it)->getState();
+            if ( (imageState == state) || (orLater && (imageState > state)) )
+                *end++ = *it;
+        }
+		if ( sBundleBeingLoaded != NULL ) {
+			dyld_image_states imageState = sBundleBeingLoaded->getState();
+			if ( (imageState == state) || (orLater && (imageState > state)) )
+				*end++ = sBundleBeingLoaded;
+		}
+        const char* dontLoadReason = NULL;
+		uint32_t imageCount = (uint32_t)(end-images);
+		if ( imageCount != 0 ) {
+			// sort bottom up
+			qsort(images, imageCount, sizeof(ImageLoader*), &imageSorter);
+			// build info array
+			for (unsigned int i=0; i < imageCount; ++i) {
+				dyld_image_info* p = &infos[i];
+				ImageLoader* image = images[i];
+				//dyld::log("  state=%d, name=%s\n", state, image->getPath());
+				p->imageLoadAddress = image->machHeader();
+				p->imageFilePath    = image->getRealPath();
+				p->imageFileModDate = image->lastModified();
+				// get these registered with the kernel as early as possible
+				if ( state == dyld_image_state_dependents_mapped)
+					notifyKernel(*image, true);
+				// special case for add_image hook
+				if ( state == dyld_image_state_bound )
+					notifyAddImageCallbacks(image);
+			}
+		}
+#if SUPPORT_ACCELERATE_TABLES
+		if ( sAllCacheImagesProxy != NULL ) {
+			unsigned cacheCount = sAllCacheImagesProxy->appendImagesToNotify(state, orLater, &infos[imageCount]);
+			// support _dyld_register_func_for_add_image()
+			if ( state == dyld_image_state_bound ) {
+				for (ImageCallback callback : sAddImageCallbacks) {
+					for (unsigned i=0; i < cacheCount; ++i) {
+						dyld3::ScopedTimer timer(DBG_DYLD_TIMING_FUNC_FOR_ADD_IMAGE, (uint64_t)infos[imageCount+i].imageLoadAddress, (uint64_t)(*callback), 0);
+						(*callback)(infos[imageCount+i].imageLoadAddress, sSharedCacheLoadInfo.slide);
+					}
+				}
+				for (LoadImageCallback func : sAddLoadImageCallbacks) {
+					for (unsigned i=0; i < cacheCount; ++i) {
+						dyld3::ScopedTimer timer(DBG_DYLD_TIMING_FUNC_FOR_ADD_IMAGE, (uint64_t)infos[imageCount+i].imageLoadAddress, (uint64_t)(*func), 0);
+						(*func)(infos[imageCount+i].imageLoadAddress, infos[imageCount+i].imageFilePath, false);
+					}
+				}
+			}
+			imageCount += cacheCount;
+		}
+#endif
+		if ( imageCount != 0 ) {
+			if ( !onlyObjCMappedNotification ) {
+				if ( onlyHandler != NULL ) {
+					const char* result = NULL;
+					if ( result == NULL ) {
+						result = (*onlyHandler)(state, imageCount, infos);
+					}
+					if ( (result != NULL) && (state == dyld_image_state_dependents_mapped) ) {
+						//fprintf(stderr, "  images rejected by handler=%p\n", onlyHandler);
+						// make copy of thrown string so that later catch clauses can free it
+						dontLoadReason = strdup(result);
+					}
+				}
+				else {
+					// call each handler with whole array
+					if ( handlers != NULL ) {
+						for (std::vector<dyld_image_state_change_handler>::iterator it = handlers->begin(); it != handlers->end(); ++it) {
+							const char* result = (*it)(state, imageCount, infos);
+							if ( (result != NULL) && (state == dyld_image_state_dependents_mapped) ) {
+								//fprintf(stderr, "  images rejected by handler=%p\n", *it);
+								// make copy of thrown string so that later catch clauses can free it
+								dontLoadReason = strdup(result);
+								break;
+							}
+						}
+					}
+				}
+			}
+			// tell objc about new images
+			if ( (onlyHandler == NULL) && ((state == dyld_image_state_bound) || (orLater && (dyld_image_state_bound > state))) && (sNotifyObjCMapped != NULL) ) {
+				const char* paths[imageCount];
+				const mach_header* mhs[imageCount];
+				unsigned objcImageCount = 0;
+				for (int i=0; i < imageCount; ++i) {
+					const ImageLoader* image = findImageByMachHeader(infos[i].imageLoadAddress);
+					bool hasObjC = false;
+					if ( image != NULL ) {
+						hasObjC = image->notifyObjC();
+					}
+#if SUPPORT_ACCELERATE_TABLES
+					else if ( sAllCacheImagesProxy != NULL ) {
+						const mach_header* mh;
+						const char* path;
+						unsigned index;
+						if ( sAllCacheImagesProxy->addressInCache(infos[i].imageLoadAddress, &mh, &path, &index) ) {
+							hasObjC = (mh->flags & MH_HAS_OBJC);
+						}
+					}
+#endif
+					if ( hasObjC ) {
+						paths[objcImageCount] = infos[i].imageFilePath;
+						mhs[objcImageCount]   = infos[i].imageLoadAddress;
+						++objcImageCount;
+					}
+				}
+				if ( objcImageCount != 0 ) {
+					dyld3::ScopedTimer timer(DBG_DYLD_TIMING_OBJC_MAP, 0, 0, 0);
+					uint64_t t0 = mach_absolute_time();
+					(*sNotifyObjCMapped)(objcImageCount, paths, mhs);
+					uint64_t t1 = mach_absolute_time();
+					ImageLoader::fgTotalObjCSetupTime += (t1-t0);
+				}
+			}
+		}
+        allImagesUnlock();
+        if ( dontLoadReason != NULL )
+            throw dontLoadReason;
+		if ( !preflightOnly && (state == dyld_image_state_dependents_mapped) ) {
+			const struct mach_header* loadAddresses[imageCount];
+			const char* loadPaths[imageCount];
+			for(uint32_t i = 0; i<imageCount; ++i) {
+				loadAddresses[i] = infos[i].imageLoadAddress;
+				loadPaths[i] = infos[i].imageFilePath;
+			}
+			notifyMonitoringDyld(false, imageCount, loadAddresses, loadPaths);
+		}
+	}
+}
+
+static void notifyBatch(dyld_image_states state, bool preflightOnly)
+{
+	notifyBatchPartial(state, false, NULL, preflightOnly, false);
+}
+
+static
+void coresymbolication_load_notifier(void* connection, uint64_t timestamp, const char* path, const struct mach_header* mh)
+{
+	const struct mach_header* loadAddress[] = { mh };
+	const char* loadPath[] = { path };
+	notifyMonitoringDyld(false, 1, loadAddress, loadPath);
+}
+
+static
+void coresymbolication_unload_notifier(void* connection, uint64_t timestamp, const char* path, const struct mach_header* mh)
+{
+	const struct mach_header* loadAddress = { mh };
+	const char* loadPath = { path };
+	notifyMonitoringDyld(true, 1, &loadAddress, &loadPath);
+}
 
 // In order for register_func_for_add_image() callbacks to to be called bottom up,
 // we need to maintain a list of root images. The main executable is usally the
@@ -208,82 +1167,210 @@
 // If DYLD_INSERT_LIBRARIES is used, those libraries are first.
 static void addRootImage(ImageLoader* image)
 {
-	//fprintf(stderr, "addRootImage(%p, %s)\n", image, image->getPath());
+	//dyld::log("addRootImage(%p, %s)\n", image, image->getPath());
 	// add to list of roots
 	sImageRoots.push_back(image);
 }
 
-// Objective-C will contain a __DATA/__image_notify section which contains pointers to a function to call
-// whenever any new image is loaded.
-static void addImageNeedingNotification(ImageLoader* image)
-{
-	sImagesToNotifyAboutOtherImages.push_back(image);
+
+static void clearAllDepths()
+{
+	for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++)
+		(*it)->clearDepth();
+}
+
+static void printAllDepths()
+{
+	for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++)
+		dyld::log("%03d %s\n",  (*it)->getDepth(), (*it)->getShortName());
+}
+
+
+static unsigned int imageCount()
+{
+    allImagesLock();
+		unsigned int result = (unsigned int)sAllImages.size();
+    allImagesUnlock();
+	return (result);
+}
+
+
+static void setNewProgramVars(const ProgramVars& newVars)
+{
+	// make a copy of the pointers to program variables
+	gLinkContext.programVars = newVars;
+	
+	// now set each program global to their initial value
+	*gLinkContext.programVars.NXArgcPtr = gLinkContext.argc;
+	*gLinkContext.programVars.NXArgvPtr = gLinkContext.argv;
+	*gLinkContext.programVars.environPtr = gLinkContext.envp;
+	*gLinkContext.programVars.__prognamePtr = gLinkContext.progname;
+}
+
+#if SUPPORT_OLD_CRT_INITIALIZATION
+static void setRunInitialzersOldWay()
+{
+	gRunInitializersOldWay = true;		
+}
+#endif
+
+static bool sandboxBlocked(const char* path, const char* kind)
+{
+#if TARGET_IPHONE_SIMULATOR
+	// sandbox calls not yet supported in simulator runtime
+	return false;
+#else
+	sandbox_filter_type filter = (sandbox_filter_type)(SANDBOX_FILTER_PATH | SANDBOX_CHECK_NO_REPORT);
+	return ( sandbox_check(getpid(), kind, filter, path) > 0 );
+#endif
+}
+
+bool sandboxBlockedMmap(const char* path)
+{
+	return sandboxBlocked(path, "file-map-executable");
+}
+
+bool sandboxBlockedOpen(const char* path)
+{
+	return sandboxBlocked(path, "file-read-data");
+}
+
+bool sandboxBlockedStat(const char* path)
+{
+	return sandboxBlocked(path, "file-read-metadata");
+}
+
+
+static void addDynamicReference(ImageLoader* from, ImageLoader* to) {
+	// don't add dynamic reference if target is in the shared cache (since it can't be unloaded)
+	if ( to->inSharedCache() )
+		return;
+
+	// don't add dynamic reference if there already is a static one
+	if ( from->dependsOn(to) )
+		return;
+	
+	// don't add if this combination already exists
+	OSSpinLockLock(&sDynamicReferencesLock);
+	for (std::vector<ImageLoader::DynamicReference>::iterator it=sDynamicReferences.begin(); it != sDynamicReferences.end(); ++it) {
+		if ( (it->from == from) && (it->to == to) ) {
+			OSSpinLockUnlock(&sDynamicReferencesLock);
+			return;
+		}
+	}
+
+	//dyld::log("addDynamicReference(%s, %s\n", from->getShortName(), to->getShortName());
+	ImageLoader::DynamicReference t;
+	t.from = from;
+	t.to = to;
+	sDynamicReferences.push_back(t);
+	OSSpinLockUnlock(&sDynamicReferencesLock);
 }
 
 static void addImage(ImageLoader* image)
 {
 	// add to master list
-	sAllImages.push_back(image);
+    allImagesLock();
+        sAllImages.push_back(image);
+    allImagesUnlock();
 	
-	if ( sEnv.DYLD_PRINT_LIBRARIES || (sEnv.DYLD_PRINT_LIBRARIES_POST_LAUNCH && (sMainExecutable!=NULL) && sMainExecutable->isLinked()) ) {
-		uint64_t offset = image->getOffsetInFatFile();
-		if ( offset == 0 )
-			fprintf(stderr, "dyld: loaded: %s\n", image->getPath());
-		else
-			fprintf(stderr, "dyld: loaded: %s, cpu-sub-type: %d\n", image->getPath(), image->machHeader()->cpusubtype);
-	}
+	// update mapped ranges
+	uintptr_t lastSegStart = 0;
+	uintptr_t lastSegEnd = 0;
+	for(unsigned int i=0, e=image->segmentCount(); i < e; ++i) {
+		if ( image->segUnaccessible(i) ) 
+			continue;
+		uintptr_t start = image->segActualLoadAddress(i);
+		uintptr_t end = image->segActualEndAddress(i);
+		if ( start == lastSegEnd ) {
+			// two segments are contiguous, just record combined segments
+			lastSegEnd = end;
+		}
+		else {
+			// non-contiguous segments, record last (if any)
+			if ( lastSegEnd != 0 )
+				addMappedRange(image, lastSegStart, lastSegEnd);
+			lastSegStart = start;
+			lastSegEnd = end;
+		}		
+	}
+	if ( lastSegEnd != 0 )
+		addMappedRange(image, lastSegStart, lastSegEnd);
+
 	
-#if OLD_GDB_DYLD_INTERFACE
-	// let gdb find out about this
-	addImageForgdb(image->machHeader(), image->getSlide(), image->getPath(), image->getLogicalPath());
-#endif
-}
+	if ( gLinkContext.verboseLoading || (sEnv.DYLD_PRINT_LIBRARIES_POST_LAUNCH && (sMainExecutable!=NULL) && sMainExecutable->isLinked()) ) {
+		dyld::log("dyld: loaded: %s\n", image->getPath());
+	}
+	
+}
+
+//
+// Helper for std::remove_if
+//
+class RefUsesImage {
+public:
+	RefUsesImage(ImageLoader* image) : _image(image) {}
+	bool operator()(const ImageLoader::DynamicReference& ref) const {
+		return ( (ref.from == _image) || (ref.to == _image) );
+	}
+private:
+	ImageLoader* _image;
+};
+
+
 
 void removeImage(ImageLoader* image)
 {
-	// if in termination list, pull it out and run terminator
-	for (std::vector<ImageLoader*>::iterator it=sImageFilesNeedingTermination.begin(); it != sImageFilesNeedingTermination.end(); it++) {
-		if ( *it == image ) {
-			sImageFilesNeedingTermination.erase(it);
-			image->doTermination(gLinkContext);
-			break;
+	// if has dtrace DOF section, tell dtrace it is going away, then remove from sImageFilesNeedingDOFUnregistration
+	for (std::vector<RegisteredDOF>::iterator it=sImageFilesNeedingDOFUnregistration.begin(); it != sImageFilesNeedingDOFUnregistration.end(); ) {
+		if ( it->mh == image->machHeader() ) {
+			unregisterDOF(it->registrationID);
+			sImageFilesNeedingDOFUnregistration.erase(it);
+			// don't increment iterator, the erase caused next element to be copied to where this iterator points
+		}
+		else {
+			++it;
 		}
 	}
 	
-	// tell all register add image handlers about this
-	// do this before removing image from internal data structures so that the callback can querey dyld about the image
-	for (std::vector<ImageCallback>::iterator it=sRemoveImageCallbacks.begin(); it != sRemoveImageCallbacks.end(); it++) {
-		(*it)(image->machHeader(), image->getSlide());
+	// tell all registered remove image handlers about this
+	// do this before removing image from internal data structures so that the callback can query dyld about the image
+	if ( image->getState() >= dyld_image_state_bound ) {
+		sRemoveImageCallbacksInUse = true; // This only runs inside dyld's global lock, so ok to use a global for the in-use flag.
+		for (std::vector<ImageCallback>::iterator it=sRemoveImageCallbacks.begin(); it != sRemoveImageCallbacks.end(); it++) {
+			dyld3::ScopedTimer timer(DBG_DYLD_TIMING_FUNC_FOR_REMOVE_IMAGE, (uint64_t)image->machHeader(), (uint64_t)(*it), 0);
+			(*it)(image->machHeader(), image->getSlide());
+		}
+		sRemoveImageCallbacksInUse = false;
+
+		if ( sNotifyObjCUnmapped !=  NULL && image->notifyObjC() )
+			(*sNotifyObjCUnmapped)(image->getRealPath(), image->machHeader());
 	}
 	
-	// tell all interested images
-	for (std::vector<ImageLoader*>::iterator it=sImagesToNotifyAboutOtherImages.begin(); it != sImagesToNotifyAboutOtherImages.end(); it++) {
-		dyld_image_info info;
-		info.imageLoadAddress = image->machHeader();
-		info.imageFilePath = image->getPath();
-		info.imageFileModDate = image->lastModified();
-		(*it)->doNotification(dyld_image_removing, 1, &info);
-	}
+	// notify 
+	notifySingle(dyld_image_state_terminated, image, NULL);
+	
+	// remove from mapped images table
+	removedMappedRanges(image);
 
 	// remove from master list
-	for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
-		if ( *it == image ) {
-			sAllImages.erase(it);
-			break;
-		}
-	}
+    allImagesLock();
+        for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+            if ( *it == image ) {
+                sAllImages.erase(it);
+                break;
+            }
+        }
+    allImagesUnlock();
 	
-	// flush find-by-address cache
+	// remove from sDynamicReferences
+	OSSpinLockLock(&sDynamicReferencesLock);
+		sDynamicReferences.erase(std::remove_if(sDynamicReferences.begin(), sDynamicReferences.end(), RefUsesImage(image)), sDynamicReferences.end());
+	OSSpinLockUnlock(&sDynamicReferencesLock);
+
+	// flush find-by-address cache (do this after removed from master list, so there is no chance it can come back)
 	if ( sLastImageByAddressCache == image )
 		sLastImageByAddressCache = NULL;
-
-	// if in announcement list, pull it out 
-	for (std::vector<ImageLoader*>::iterator it=sImagesToNotifyAboutOtherImages.begin(); it != sImagesToNotifyAboutOtherImages.end(); it++) {
-		if ( *it == image ) {
-			sImagesToNotifyAboutOtherImages.erase(it);
-			break;
-		}
-	}
 
 	// if in root list, pull it out 
 	for (std::vector<ImageLoader*>::iterator it=sImageRoots.begin(); it != sImageRoots.end(); it++) {
@@ -293,16 +1380,33 @@
 		}
 	}
 
+	// log if requested
+	if ( gLinkContext.verboseLoading || (sEnv.DYLD_PRINT_LIBRARIES_POST_LAUNCH && (sMainExecutable!=NULL) && sMainExecutable->isLinked()) ) {
+		dyld::log("dyld: unloaded: %s\n", image->getPath());
+	}
+
 	// tell gdb, new way
 	removeImageFromAllImages(image->machHeader());
-
-#if OLD_GDB_DYLD_INTERFACE
-	// tell gdb, old way
-	removeImageForgdb(image->machHeader());
-	gdb_dyld_state_changed();
-#endif
-}
-
+}
+
+
+void runImageStaticTerminators(ImageLoader* image)
+{
+	// if in termination list, pull it out and run terminator
+	bool mightBeMore;
+	do {
+		mightBeMore = false;
+		for (std::vector<ImageLoader*>::iterator it=sImageFilesNeedingTermination.begin(); it != sImageFilesNeedingTermination.end(); it++) {
+			if ( *it == image ) {
+				sImageFilesNeedingTermination.erase(it);
+				if (gLogAPIs) dyld::log("dlclose(), running static terminators for %p %s\n", image, image->getShortName());
+				image->doTermination(gLinkContext);
+				mightBeMore = true;
+				break;
+			}
+		}
+	} while ( mightBeMore );
+}
 
 static void terminationRecorder(ImageLoader* image)
 {
@@ -314,27 +1418,49 @@
 	return sExecPath;
 }
 
+static void runAllStaticTerminators(void* extra)
+{
+	try {
+		const size_t imageCount = sImageFilesNeedingTermination.size();
+		for(size_t i=imageCount; i > 0; --i){
+			ImageLoader* image = sImageFilesNeedingTermination[i-1];
+			image->doTermination(gLinkContext);
+		}
+		sImageFilesNeedingTermination.clear();
+		notifyBatch(dyld_image_state_terminated, false);
+	}
+	catch (const char* msg) {
+		halt(msg);
+	}
+}
 
 void initializeMainExecutable()
 {
-	const int rootCount = sImageRoots.size();
-	for(int i=0; i < rootCount; ++i) {
-		ImageLoader* image = sImageRoots[i];
-		//fprintf(stderr, "initializeMainExecutable: image = %p\n", image);
-		image->runInitializers(gLinkContext);
-	}
-/*
-	// this does not work???
-	for (std::vector<ImageLoader*>::iterator it=sImageRoots.begin(); it != sImageRoots.end(); it++) {
-		ImageLoader* image = *it;
-		fprintf(stderr, "initializeMainExecutable: image = %p\n", image);
-		// don't know why vector sometimes starts with NULL element???
-		if ( image != NULL ) 
-			image->runInitializers(gLinkContext);
-	}
-*/
+	// record that we've reached this step
+	gLinkContext.startedInitializingMainExecutable = true;
+
+	// run initialzers for any inserted dylibs
+	ImageLoader::InitializerTimingList initializerTimes[allImagesCount()];
+	initializerTimes[0].count = 0;
+	const size_t rootCount = sImageRoots.size();
+	if ( rootCount > 1 ) {
+		for(size_t i=1; i < rootCount; ++i) {
+			sImageRoots[i]->runInitializers(gLinkContext, initializerTimes[0]);
+		}
+	}
+	
+	// run initializers for main executable and everything it brings up 
+	sMainExecutable->runInitializers(gLinkContext, initializerTimes[0]);
+	
+	// register cxa_atexit() handler to run static terminators in all loaded images when this process exits
+	if ( gLibSystemHelpers != NULL ) 
+		(*gLibSystemHelpers->cxa_atexit)(&runAllStaticTerminators, NULL, NULL);
+
+	// dump info if requested
 	if ( sEnv.DYLD_PRINT_STATISTICS )
-		ImageLoaderMachO::printStatistics(sAllImages.size());
+		ImageLoader::printStatistics((unsigned int)allImagesCount(), initializerTimes[0]);
+	if ( sEnv.DYLD_PRINT_STATISTICS_DETAILS )
+		ImageLoaderMachO::printStatisticsDetails((unsigned int)allImagesCount(), initializerTimes[0]);
 }
 
 bool mainExecutablePrebound()
@@ -348,27 +1474,144 @@
 }
 
 
-void runTerminators()
-{
-	const unsigned int imageCount = sImageFilesNeedingTermination.size();
-	for(unsigned int i=imageCount; i > 0; --i){
-		ImageLoader* image = sImageFilesNeedingTermination[i-1];
-		image->doTermination(gLinkContext);
-	}
-	sImageFilesNeedingTermination.clear();
-}
+
+
+#if SUPPORT_VERSIONED_PATHS
+
+// forward reference
+static bool getDylibVersionAndInstallname(const char* dylibPath, uint32_t* version, char* installName);
 
 
 //
-// Turns a colon separated list of strings
-// into a NULL terminated array of string 
-// pointers.
+// Examines a dylib file and if its current_version is newer than the installed
+// dylib at its install_name, then add the dylib file to sDylibOverrides.
 //
-static const char** parseColonList(const char* list)
-{
-	if ( list[0] == '\0' )
-		return NULL;
-
+static void checkDylibOverride(const char* dylibFile)
+{
+	//dyld::log("checkDylibOverride('%s')\n", dylibFile);
+	uint32_t altVersion;
+ 	char sysInstallName[PATH_MAX];
+	if ( getDylibVersionAndInstallname(dylibFile, &altVersion, sysInstallName) && (sysInstallName[0] =='/') ) {
+		//dyld::log("%s has version 0x%08X and install name %s\n", dylibFile, altVersion, sysInstallName);
+		uint32_t sysVersion;
+		if ( getDylibVersionAndInstallname(sysInstallName, &sysVersion, NULL) ) {
+			//dyld::log("%s has version 0x%08X\n", sysInstallName, sysVersion);
+			if ( altVersion > sysVersion ) {
+				//dyld::log("override found: %s -> %s\n", sysInstallName, dylibFile);
+				// see if there already is an override for this dylib
+				bool entryExists = false;
+				for (std::vector<DylibOverride>::iterator it = sDylibOverrides.begin(); it != sDylibOverrides.end(); ++it) {
+					if ( strcmp(it->installName, sysInstallName) == 0 ) {
+						entryExists = true;
+						uint32_t prevVersion;
+						if ( getDylibVersionAndInstallname(it->override, &prevVersion, NULL) ) {
+							if ( altVersion > prevVersion ) {
+								// found an even newer override
+								free((void*)(it->override));
+								char resolvedPath[PATH_MAX];
+								if ( realpath(dylibFile, resolvedPath) != NULL )
+									it->override = strdup(resolvedPath);
+								else
+									it->override = strdup(dylibFile);
+								break;
+							}
+						}
+					}
+				}
+				if ( ! entryExists ) {
+					DylibOverride entry;
+					entry.installName = strdup(sysInstallName);
+					char resolvedPath[PATH_MAX];
+					if ( realpath(dylibFile, resolvedPath) != NULL )
+						entry.override = strdup(resolvedPath);
+					else
+						entry.override = strdup(dylibFile);
+					sDylibOverrides.push_back(entry);
+					//dyld::log("added override: %s -> %s\n", entry.installName, entry.override);
+				}
+			}
+		}
+	}
+	
+}
+
+static void checkDylibOverridesInDir(const char* dirPath)
+{
+	//dyld::log("checkDylibOverridesInDir('%s')\n", dirPath);
+	char dylibPath[PATH_MAX];
+	long dirPathLen = strlcpy(dylibPath, dirPath, PATH_MAX-1);
+	if ( dirPathLen >= PATH_MAX )
+		return;
+	DIR* dirp = opendir(dirPath);
+	if ( dirp != NULL) {
+		dirent entry;
+		dirent* entp = NULL;
+		while ( readdir_r(dirp, &entry, &entp) == 0 ) {
+			if ( entp == NULL )
+				break;
+			if ( entp->d_type != DT_REG ) 
+				continue;
+			dylibPath[dirPathLen] = '/';
+			dylibPath[dirPathLen+1] = '\0';
+			if ( strlcat(dylibPath, entp->d_name, PATH_MAX) >= PATH_MAX )
+				continue;
+			checkDylibOverride(dylibPath);
+		}
+		closedir(dirp);
+	}
+}
+
+
+static void checkFrameworkOverridesInDir(const char* dirPath)
+{
+	//dyld::log("checkFrameworkOverridesInDir('%s')\n", dirPath);
+	char frameworkPath[PATH_MAX];
+	long dirPathLen = strlcpy(frameworkPath, dirPath, PATH_MAX-1);
+	if ( dirPathLen >= PATH_MAX )
+		return;
+	DIR* dirp = opendir(dirPath);
+	if ( dirp != NULL) {
+		dirent entry;
+		dirent* entp = NULL;
+		while ( readdir_r(dirp, &entry, &entp) == 0 ) {
+			if ( entp == NULL )
+				break;
+			if ( entp->d_type != DT_DIR ) 
+				continue;
+			frameworkPath[dirPathLen] = '/';
+			frameworkPath[dirPathLen+1] = '\0';
+			int dirNameLen = (int)strlen(entp->d_name);
+			if ( dirNameLen < 11 )
+				continue;
+			if ( strcmp(&entp->d_name[dirNameLen-10], ".framework") != 0 )
+				continue;
+			if ( strlcat(frameworkPath, entp->d_name, PATH_MAX) >= PATH_MAX )
+				continue;
+			if ( strlcat(frameworkPath, "/", PATH_MAX) >= PATH_MAX )
+				continue;
+			if ( strlcat(frameworkPath, entp->d_name, PATH_MAX) >= PATH_MAX )
+				continue;
+			frameworkPath[strlen(frameworkPath)-10] = '\0';
+			checkDylibOverride(frameworkPath);
+		}
+		closedir(dirp);
+	}
+}
+#endif // SUPPORT_VERSIONED_PATHS
+
+
+//
+// Turns a colon separated list of strings into a NULL terminated array 
+// of string pointers. If mainExecutableDir param is not NULL,
+// substitutes @loader_path with main executable's dir.
+//
+static const char** parseColonList(const char* list, const char* mainExecutableDir)
+{
+	static const char* sEmptyList[] = { NULL };
+
+	if ( list[0] == '\0' ) 
+		return sEmptyList;
+	
 	int colonCount = 0;
 	for(const char* s=list; *s != '\0'; ++s) {
 		if (*s == ':') 
@@ -380,54 +1623,112 @@
 	char** result = new char*[colonCount+2];
 	for(const char* s=list; *s != '\0'; ++s) {
 		if (*s == ':') {
-			int len = s-start;
-			char* str = new char[len+1];
-			strncpy(str, start, len);
-			str[len] = '\0';
-			start = &s[1];
+			size_t len = s-start;
+			if ( (mainExecutableDir != NULL) && (strncmp(start, "@loader_path/", 13) == 0) ) {
+				if ( !gLinkContext.allowAtPaths ) {
+					dyld::log("dyld: warning: @loader_path/ ignored because of amfi policy\n");
+					continue;
+				}
+				size_t mainExecDirLen = strlen(mainExecutableDir);
+				char* str = new char[mainExecDirLen+len+1];
+				strcpy(str, mainExecutableDir);
+				strlcat(str, &start[13], mainExecDirLen+len+1);
+				str[mainExecDirLen+len-13] = '\0';
+				start = &s[1];
+				result[index++] = str;
+			}
+			else if ( (mainExecutableDir != NULL) && (strncmp(start, "@executable_path/", 17) == 0) ) {
+				if ( !gLinkContext.allowAtPaths ) {
+					dyld::log("dyld: warning: @executable_path/ ignored because of amfi policy\n");
+					continue;
+				}
+				size_t mainExecDirLen = strlen(mainExecutableDir);
+				char* str = new char[mainExecDirLen+len+1];
+				strcpy(str, mainExecutableDir);
+				strlcat(str, &start[17], mainExecDirLen+len+1);
+				str[mainExecDirLen+len-17] = '\0';
+				start = &s[1];
+				result[index++] = str;
+			}
+			else {
+				char* str = new char[len+1];
+				strncpy(str, start, len);
+				str[len] = '\0';
+				start = &s[1];
+				result[index++] = str;
+			}
+		}
+	}
+	size_t len = strlen(start);
+	if ( (mainExecutableDir != NULL) && (strncmp(start, "@loader_path/", 13) == 0) ) {
+		if ( !gLinkContext.allowAtPaths ) {
+			dyld::log("dyld: warning: @loader_path/ ignored because of amfi policy\n");
+		}
+		else
+		{
+			size_t mainExecDirLen = strlen(mainExecutableDir);
+			char* str = new char[mainExecDirLen+len+1];
+			strcpy(str, mainExecutableDir);
+			strlcat(str, &start[13], mainExecDirLen+len+1);
+			str[mainExecDirLen+len-13] = '\0';
 			result[index++] = str;
 		}
 	}
-	int len = strlen(start);
-	char* str = new char[len+1];
-	strcpy(str, start);
-	result[index++] = str;
+	else if ( (mainExecutableDir != NULL) && (strncmp(start, "@executable_path/", 17) == 0) ) {
+		if ( !gLinkContext.allowAtPaths ) {
+			dyld::log("dyld: warning: @executable_path/ ignored because of amfi policy\n");
+		}
+		else
+		{
+			size_t mainExecDirLen = strlen(mainExecutableDir);
+			char* str = new char[mainExecDirLen+len+1];
+			strcpy(str, mainExecutableDir);
+			strlcat(str, &start[17], mainExecDirLen+len+1);
+			str[mainExecDirLen+len-17] = '\0';
+			result[index++] = str;
+		}
+	}
+	else {
+		char* str = new char[len+1];
+		strcpy(str, start);
+		result[index++] = str;
+	}
 	result[index] = NULL;
 	
+	//dyld::log("parseColonList(%s)\n", list);
+	//for(int i=0; result[i] != NULL; ++i)
+	//	dyld::log("  %s\n", result[i]);
 	return (const char**)result;
 }
 
-/*
- * Library path searching is not done for setuid programs
- * which are not run by the real user.  Futher the
- * evironment varaible for the library path is cleared so
- * that if this program executes a non-set uid program this
- * part of the evironment will not be passed along so that
- * that program also will not have it's libraries searched
- * for.
- */
- static bool riskyUser()
- {
-	static bool checked = false;
-	static bool risky = false;
-	if ( !checked ) {
-		risky = ( getuid() != 0 && (getuid() != geteuid() || getgid() != getegid()) );
-		checked = true;
-	}
-	return risky;
- }
- 
- 
-static bool disableIfBadUser(char* rhs)
-{
-	bool didDisable = false;
-	if ( riskyUser() ) {
-		*rhs ='\0';
-		didDisable = true;
-	}
-	return didDisable;
-}
-
+static void	appendParsedColonList(const char* list, const char* mainExecutableDir, const char* const ** storage)
+{
+	const char** newlist = parseColonList(list, mainExecutableDir);
+	if ( *storage == NULL ) {
+		// first time, just set
+		*storage = newlist;
+	}
+	else {
+		// need to append to existing list
+		const char* const* existing = *storage;
+		int count = 0;
+		for(int i=0; existing[i] != NULL; ++i)
+			++count;
+		for(int i=0; newlist[i] != NULL; ++i)
+			++count;
+		const char** combinedList = new const char*[count+2];
+		int index = 0;
+		for(int i=0; existing[i] != NULL; ++i)
+			combinedList[index++] = existing[i];
+		for(int i=0; newlist[i] != NULL; ++i)
+			combinedList[index++] = newlist[i];
+		combinedList[index] = NULL;
+		// leak old arrays
+		*storage = combinedList;
+	}
+}
+
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
 static void paths_expand_roots(const char **paths, const char *key, const char *val)
 {
 // 	assert(val != NULL);
@@ -448,13 +1749,19 @@
 
 static void removePathWithPrefix(const char* paths[], const char* prefix)
 {
-	size_t prefixLen = strlen(prefix);
-	for(int s=0,d=0; (paths[d] != NULL) && (paths[s] != NULL); ++s, ++d) {
-		if ( strncmp(paths[s], prefix, prefixLen) == 0 )
-			++s;
-		paths[d] = paths[s];
-	}
-}
+    size_t prefixLen = strlen(prefix);
+    int skip = 0;
+    int i;
+    for(i = 0; paths[i] != NULL; ++i) {
+        if ( strncmp(paths[i], prefix, prefixLen) == 0 )
+            ++skip;
+        else
+            paths[i-skip] = paths[i];
+    }
+    paths[i-skip] = NULL;
+}
+#endif
+
 
 #if 0
 static void paths_dump(const char **paths)
@@ -463,18 +1770,20 @@
   const char **strs = paths;
   while(*strs != NULL)
   {
-    fprintf(stderr, "\"%s\"\n", *strs);
+    dyld::log("\"%s\"\n", *strs);
     strs++;
   }
   return;
 }
 #endif
 
+
+
 static void printOptions(const char* argv[])
 {
 	uint32_t i = 0;
 	while ( NULL != argv[i] ) {
-		fprintf(stderr, "opt[%i] = \"%s\"\n", i, argv[i]);
+		dyld::log("opt[%i] = \"%s\"\n", i, argv[i]);
 		i++;
 	}
 }
@@ -482,58 +1791,47 @@
 static void printEnvironmentVariables(const char* envp[])
 {
 	while ( NULL != *envp ) {
-		fprintf(stderr, "%s\n", *envp);
+		dyld::log("%s\n", *envp);
 		envp++;
 	}
 }
 
-
-
-void processDyldEnvironmentVarible(const char* key, const char* value)
+void processDyldEnvironmentVariable(const char* key, const char* value, const char* mainExecutableDir)
 {
 	if ( strcmp(key, "DYLD_FRAMEWORK_PATH") == 0 ) {
-		if ( !disableIfBadUser((char*)value) )
-			sEnv.DYLD_FRAMEWORK_PATH = parseColonList(value);
+		appendParsedColonList(value, mainExecutableDir, &sEnv.DYLD_FRAMEWORK_PATH);
 	}
 	else if ( strcmp(key, "DYLD_FALLBACK_FRAMEWORK_PATH") == 0 ) {
-		if ( !disableIfBadUser((char*)value) )
-			sEnv.DYLD_FALLBACK_FRAMEWORK_PATH = parseColonList(value);
+		appendParsedColonList(value, mainExecutableDir, &sEnv.DYLD_FALLBACK_FRAMEWORK_PATH);
 	}
 	else if ( strcmp(key, "DYLD_LIBRARY_PATH") == 0 ) {
-		if ( !disableIfBadUser((char*)value) )
-			sEnv.DYLD_LIBRARY_PATH = parseColonList(value);
+		appendParsedColonList(value, mainExecutableDir, &sEnv.DYLD_LIBRARY_PATH);
 	}
 	else if ( strcmp(key, "DYLD_FALLBACK_LIBRARY_PATH") == 0 ) {
-		if ( !disableIfBadUser((char*)value) )
-			sEnv.DYLD_FALLBACK_LIBRARY_PATH = parseColonList(value);
-	}
+		appendParsedColonList(value, mainExecutableDir, &sEnv.DYLD_FALLBACK_LIBRARY_PATH);
+	}
+#if SUPPORT_ROOT_PATH
 	else if ( (strcmp(key, "DYLD_ROOT_PATH") == 0) || (strcmp(key, "DYLD_PATHS_ROOT") == 0) ) {
-		if ( !disableIfBadUser((char*)value) ) {
-			if ( strcmp(value, "/") != 0 ) {
-				sEnv.DYLD_ROOT_PATH = parseColonList(value);
-				for (int i=0; sEnv.DYLD_ROOT_PATH[i] != NULL; ++i) {
-					if ( sEnv.DYLD_ROOT_PATH[i][0] != '/' ) {
-						fprintf(stderr, "dyld: warning DYLD_ROOT_PATH not used because it contains a non-absolute path\n");
-						sEnv.DYLD_ROOT_PATH = NULL;
-						break;
-					}
+		if ( strcmp(value, "/") != 0 ) {
+			gLinkContext.rootPaths = parseColonList(value, mainExecutableDir);
+			for (int i=0; gLinkContext.rootPaths[i] != NULL; ++i) {
+				if ( gLinkContext.rootPaths[i][0] != '/' ) {
+					dyld::warn("DYLD_ROOT_PATH not used because it contains a non-absolute path\n");
+					gLinkContext.rootPaths = NULL;
+					break;
 				}
 			}
 		}
-	} 
+	}
+#endif
 	else if ( strcmp(key, "DYLD_IMAGE_SUFFIX") == 0 ) {
-		if ( !disableIfBadUser((char*)value) )
-			gLinkContext.imageSuffix = value;
+		gLinkContext.imageSuffix = parseColonList(value, NULL);
 	}
 	else if ( strcmp(key, "DYLD_INSERT_LIBRARIES") == 0 ) {
-		if ( !disableIfBadUser((char*)value) )
-			sEnv.DYLD_INSERT_LIBRARIES = parseColonList(value);
-	}
-	else if ( strcmp(key, "DYLD_DEBUG_TRACE") == 0 ) {
-		fprintf(stderr, "dyld: warning DYLD_DEBUG_TRACE not supported\n");
-	}
-	else if ( strcmp(key, "DYLD_ERROR_PRINT") == 0 ) {
-		fprintf(stderr, "dyld: warning DYLD_ERROR_PRINT not supported\n");
+		sEnv.DYLD_INSERT_LIBRARIES = parseColonList(value, NULL);
+#if SUPPORT_ACCELERATE_TABLES
+		sDisableAcceleratorTables = true;
+#endif
 	}
 	else if ( strcmp(key, "DYLD_PRINT_OPTS") == 0 ) {
 		sEnv.DYLD_PRINT_OPTS = true;
@@ -541,63 +1839,53 @@
 	else if ( strcmp(key, "DYLD_PRINT_ENV") == 0 ) {
 		sEnv.DYLD_PRINT_ENV = true;
 	}
+	else if ( strcmp(key, "DYLD_DISABLE_DOFS") == 0 ) {
+		sEnv.DYLD_DISABLE_DOFS = true;
+	}
+	else if ( strcmp(key, "DYLD_DISABLE_PREFETCH") == 0 ) {
+		gLinkContext.preFetchDisabled = true;
+	}
 	else if ( strcmp(key, "DYLD_PRINT_LIBRARIES") == 0 ) {
-		sEnv.DYLD_PRINT_LIBRARIES = true;
+		gLinkContext.verboseLoading = true;
 	}
 	else if ( strcmp(key, "DYLD_PRINT_LIBRARIES_POST_LAUNCH") == 0 ) {
 		sEnv.DYLD_PRINT_LIBRARIES_POST_LAUNCH = true;
 	}
-	else if ( strcmp(key, "DYLD_TRACE") == 0 ) {
-		fprintf(stderr, "dyld: warning DYLD_TRACE not supported\n");
-	}
-	else if ( strcmp(key, "DYLD_EBADEXEC_ONLY") == 0 ) {
-		fprintf(stderr, "dyld: warning DYLD_EBADEXEC_ONLY not supported\n");
-	}
 	else if ( strcmp(key, "DYLD_BIND_AT_LAUNCH") == 0 ) {
 		sEnv.DYLD_BIND_AT_LAUNCH = true;
 	}
 	else if ( strcmp(key, "DYLD_FORCE_FLAT_NAMESPACE") == 0 ) {
 		gLinkContext.bindFlat = true;
 	}
-	else if ( strcmp(key, "DYLD_DEAD_LOCK_HANG") == 0 ) {
-		fprintf(stderr, "dyld: warning DYLD_DEAD_LOCK_HANG not supported\n");
-	}
-	else if ( strcmp(key, "DYLD_ABORT_MULTIPLE_INITS") == 0 ) {
-		fprintf(stderr, "dyld: warning DYLD_ABORT_MULTIPLE_INITS not supported\n");
-	}
 	else if ( strcmp(key, "DYLD_NEW_LOCAL_SHARED_REGIONS") == 0 ) {
-		gLinkContext.sharedRegionMode = ImageLoader::kUsePrivateSharedRegion;
-	}
-	else if ( strcmp(key, "DYLD_SLIDE_AND_PACK_DYLIBS") == 0 ) {
-		gLinkContext.slideAndPackDylibs = true;
+		// ignore, no longer relevant but some scripts still set it
 	}
 	else if ( strcmp(key, "DYLD_NO_FIX_PREBINDING") == 0 ) {
-		// since the new dyld never runs fix_prebinding, no need to warn if someone does not want it run
-		//fprintf(stderr, "dyld: warning DYLD_NO_FIX_PREBINDING not supported\n");
 	}
 	else if ( strcmp(key, "DYLD_PREBIND_DEBUG") == 0 ) {
 		gLinkContext.verbosePrebinding = true;
 	}
-	else if ( strcmp(key, "DYLD_HINTS_DEBUG") == 0 ) {
-		fprintf(stderr, "dyld: warning DYLD_HINTS_DEBUG not supported\n");
-	}
-	else if ( strcmp(key, "DYLD_SAMPLE_DEBUG") == 0 ) {
-		fprintf(stderr, "dyld: warning DYLD_SAMPLE_DEBUG not supported\n");
-	}
-	else if ( strcmp(key, "DYLD_EXECUTABLE_PATH_DEBUG") == 0 ) {
-		fprintf(stderr, "dyld: warning DYLD_EXECUTABLE_PATH_DEBUG not supported\n");
-	}
-	else if ( strcmp(key, "DYLD_TWO_LEVEL_DEBUG") == 0 ) {
-		fprintf(stderr, "dyld: warning DYLD_TWO_LEVEL_DEBUG not supported\n");
-	}
-	else if ( strcmp(key, "DYLD_LAZY_INITIALIZERS") == 0 ) {
-		fprintf(stderr, "dyld: warning DYLD_LAZY_INITIALIZERS not supported\n");
-	}
 	else if ( strcmp(key, "DYLD_PRINT_INITIALIZERS") == 0 ) {
 		gLinkContext.verboseInit = true;
 	}
+	else if ( strcmp(key, "DYLD_PRINT_DOFS") == 0 ) {
+		gLinkContext.verboseDOF = true;
+	}
 	else if ( strcmp(key, "DYLD_PRINT_STATISTICS") == 0 ) {
 		sEnv.DYLD_PRINT_STATISTICS = true;
+#if __IPHONE_OS_VERSION_MIN_REQUIRED && !TARGET_IPHONE_SIMULATOR
+		// <rdar://problem/26614838> DYLD_PRINT_STATISTICS no longer logs to xcode console for device apps
+		sForceStderr = true;
+#endif
+	}
+	else if ( strcmp(key, "DYLD_PRINT_TO_STDERR") == 0 ) {
+#if __IPHONE_OS_VERSION_MIN_REQUIRED && !TARGET_IPHONE_SIMULATOR
+		// <rdar://problem/26633440> DYLD_PRINT_STATISTICS no longer logs to xcode console for device apps
+		sForceStderr = true;
+#endif
+	}
+	else if ( strcmp(key, "DYLD_PRINT_STATISTICS_DETAILS") == 0 ) {
+		sEnv.DYLD_PRINT_STATISTICS_DETAILS = true;
 	}
 	else if ( strcmp(key, "DYLD_PRINT_SEGMENTS") == 0 ) {
 		gLinkContext.verboseMapping = true;
@@ -605,16 +1893,33 @@
 	else if ( strcmp(key, "DYLD_PRINT_BINDINGS") == 0 ) {
 		gLinkContext.verboseBind = true;
 	}
+	else if ( strcmp(key, "DYLD_PRINT_WEAK_BINDINGS") == 0 ) {
+		gLinkContext.verboseWeakBind = true;
+	}
 	else if ( strcmp(key, "DYLD_PRINT_REBASINGS") == 0 ) {
 		gLinkContext.verboseRebase = true;
 	}
 	else if ( strcmp(key, "DYLD_PRINT_APIS") == 0 ) {
 		gLogAPIs = true;
 	}
+#if SUPPORT_ACCELERATE_TABLES
+	else if ( strcmp(key, "DYLD_PRINT_APIS_APP") == 0 ) {
+		gLogAppAPIs = true;
+	}
+#endif
 	else if ( strcmp(key, "DYLD_PRINT_WARNINGS") == 0 ) {
 		gLinkContext.verboseWarnings = true;
 	}
-	else if ( strcmp(key, "DYLD_SHARED_REGION") == 0 ) {
+	else if ( strcmp(key, "DYLD_PRINT_RPATHS") == 0 ) {
+		gLinkContext.verboseRPaths = true;
+	}
+	else if ( strcmp(key, "DYLD_PRINT_INTERPOSING") == 0 ) {
+		gLinkContext.verboseInterposing = true;
+	}
+	else if ( strcmp(key, "DYLD_PRINT_CODE_SIGNATURES") == 0 ) {
+		gLinkContext.verboseCodeSignatures = true;
+	}
+	else if ( (strcmp(key, "DYLD_SHARED_REGION") == 0) && gLinkContext.allowEnvVarsSharedCache ) {
 		if ( strcmp(value, "private") == 0 ) {
 			gLinkContext.sharedRegionMode = ImageLoader::kUsePrivateSharedRegion;
 		}
@@ -628,7 +1933,19 @@
 			gLinkContext.sharedRegionMode = ImageLoader::kUseSharedRegion;
 		}
 		else {
-			fprintf(stderr, "dyld: warning unknown option to DYLD_SHARED_REGION.  Valid options are: use, private, avoid\n");
+			dyld::warn("unknown option to DYLD_SHARED_REGION.  Valid options are: use, private, avoid\n");
+		}
+	}
+	else if ( (strcmp(key, "DYLD_SHARED_CACHE_DIR") == 0) && gLinkContext.allowEnvVarsSharedCache  ) {
+		sSharedCacheOverrideDir = value;
+	}
+	else if ( strcmp(key, "DYLD_USE_CLOSURES") == 0 ) {
+		if ( dyld3::internalInstall() ) {
+#if __MAC_OS_X_VERSION_MIN_REQUIRED && __i386__
+			// don't support dyld3 for 32-bit macOS
+#else
+			sEnableClosures = true;
+#endif
 		}
 	}
 	else if ( strcmp(key, "DYLD_IGNORE_PREBINDING") == 0 ) {
@@ -645,198 +1962,423 @@
 			gLinkContext.prebindUsage = ImageLoader::kUseSplitSegPrebinding;
 		}
 		else {
-			fprintf(stderr, "dyld: warning unknown option to DYLD_IGNORE_PREBINDING.  Valid options are: all, app, nonsplit\n");
-		}
-	}
+			dyld::warn("unknown option to DYLD_IGNORE_PREBINDING.  Valid options are: all, app, nonsplit\n");
+		}
+	}
+#if SUPPORT_VERSIONED_PATHS
+	else if ( strcmp(key, "DYLD_VERSIONED_LIBRARY_PATH") == 0 ) {
+		appendParsedColonList(value, mainExecutableDir, &sEnv.DYLD_VERSIONED_LIBRARY_PATH);
+	#if SUPPORT_ACCELERATE_TABLES
+		sDisableAcceleratorTables = true;
+	#endif
+	}
+	else if ( strcmp(key, "DYLD_VERSIONED_FRAMEWORK_PATH") == 0 ) {
+		appendParsedColonList(value, mainExecutableDir, &sEnv.DYLD_VERSIONED_FRAMEWORK_PATH);
+	#if SUPPORT_ACCELERATE_TABLES
+		sDisableAcceleratorTables = true;
+	#endif
+	}
+#endif
+#if !TARGET_IPHONE_SIMULATOR
+	else if ( (strcmp(key, "DYLD_PRINT_TO_FILE") == 0) && (mainExecutableDir == NULL) && gLinkContext.allowEnvVarsSharedCache ) {
+		int fd = open(value, O_WRONLY | O_CREAT | O_APPEND, 0644);
+		if ( fd != -1 ) {
+			sLogfile = fd;
+			sLogToFile = true;
+		}
+		else {
+			dyld::log("dyld: could not open DYLD_PRINT_TO_FILE='%s', errno=%d\n", value, errno);
+		}
+	}
+	else if ( (strcmp(key, "DYLD_SKIP_MAIN") == 0)) {
+		if ( dyld3::internalInstall() )
+			sSkipMain = true;
+	}
+#endif
 	else {
-		fprintf(stderr, "dyld: warning, unknown environment variable: %s\n", key);
-	}
-}
-
-
-static void checkEnvironmentVariables(const char* envp[], bool ignoreEnviron)
-{
-	const char* home = NULL;
+		dyld::warn("unknown environment variable: %s\n", key);
+	}
+}
+
+
+#if SUPPORT_LC_DYLD_ENVIRONMENT
+static void checkLoadCommandEnvironmentVariables()
+{
+	// <rdar://problem/8440934> Support augmenting dyld environment variables in load commands
+	const uint32_t cmd_count = sMainExecutableMachHeader->ncmds;
+	const struct load_command* const cmds = (struct load_command*)(((char*)sMainExecutableMachHeader)+sizeof(macho_header));
+	const struct load_command* cmd = cmds;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		switch (cmd->cmd) {
+			case LC_DYLD_ENVIRONMENT:
+			{
+				const struct dylinker_command* envcmd = (struct dylinker_command*)cmd;
+				const char* keyEqualsValue = (char*)envcmd + envcmd->name.offset;
+				char mainExecutableDir[strlen(sExecPath)+2];
+				strcpy(mainExecutableDir, sExecPath);
+				char* lastSlash = strrchr(mainExecutableDir, '/');
+				if ( lastSlash != NULL)
+					lastSlash[1] = '\0';
+				// only process variables that start with DYLD_ and end in _PATH
+				if ( (strncmp(keyEqualsValue, "DYLD_", 5) == 0) ) {
+					const char* equals = strchr(keyEqualsValue, '=');
+					if ( equals != NULL ) {
+						if ( strncmp(&equals[-5], "_PATH", 5) == 0 ) {
+							const char* value = &equals[1];
+							const size_t keyLen = equals-keyEqualsValue;
+							// <rdar://problem/22799635> don't let malformed load command overflow stack
+							if ( keyLen < 40 ) {
+								char key[keyLen+1];
+								strncpy(key, keyEqualsValue, keyLen);
+								key[keyLen] = '\0';
+								//dyld::log("processing: %s\n", keyEqualsValue);
+								//dyld::log("mainExecutableDir: %s\n", mainExecutableDir);
+								processDyldEnvironmentVariable(key, value, mainExecutableDir);
+							}
+						}
+					}
+				}
+			}
+			break;
+		}
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+	}
+}
+#endif // SUPPORT_LC_DYLD_ENVIRONMENT	
+
+	
+static bool hasCodeSignatureLoadCommand(const macho_header* mh)
+{
+	const uint32_t cmd_count = mh->ncmds;
+	const struct load_command* const cmds = (struct load_command*)(((char*)mh)+sizeof(macho_header));
+	const struct load_command* cmd = cmds;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		if (cmd->cmd == LC_CODE_SIGNATURE) 
+			return true;
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+	}
+	return false;
+}
+	
+
+#if SUPPORT_VERSIONED_PATHS
+static void checkVersionedPaths()
+{
+	// search DYLD_VERSIONED_LIBRARY_PATH directories for dylibs and check if they are newer
+	if ( sEnv.DYLD_VERSIONED_LIBRARY_PATH != NULL ) {
+		for(const char* const* lp = sEnv.DYLD_VERSIONED_LIBRARY_PATH; *lp != NULL; ++lp) {
+			checkDylibOverridesInDir(*lp);
+		}
+	}
+	
+	// search DYLD_VERSIONED_FRAMEWORK_PATH directories for dylibs and check if they are newer
+	if ( sEnv.DYLD_VERSIONED_FRAMEWORK_PATH != NULL ) {
+		for(const char* const* fp = sEnv.DYLD_VERSIONED_FRAMEWORK_PATH; *fp != NULL; ++fp) {
+			checkFrameworkOverridesInDir(*fp);
+		}
+	}
+}
+#endif	
+
+
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+//
+// For security, setuid programs ignore DYLD_* environment variables.
+// Additionally, the DYLD_* enviroment variables are removed
+// from the environment, so that any child processes don't see them.
+//
+static void pruneEnvironmentVariables(const char* envp[], const char*** applep)
+{
+#if SUPPORT_LC_DYLD_ENVIRONMENT
+	checkLoadCommandEnvironmentVariables();
+#endif
+
+    // Are we testing dyld on an internal config?
+    if ( _simple_getenv(envp, "DYLD_SKIP_MAIN") != NULL ) {
+		if ( dyld3::internalInstall() )
+            sSkipMain = true;
+    }
+
+	// delete all DYLD_* and LD_LIBRARY_PATH environment variables
+	int removedCount = 0;
+	const char** d = envp;
+	for(const char** s = envp; *s != NULL; s++) {
+		
+	    if ( (strncmp(*s, "DYLD_", 5) != 0) && (strncmp(*s, "LD_LIBRARY_PATH=", 16) != 0) ) {
+			*d++ = *s;
+		}
+		else {
+			++removedCount;
+		}
+	}
+	*d++ = NULL;
+	// slide apple parameters
+	if ( removedCount > 0 ) {
+		*applep = d;
+		do {
+			*d = d[removedCount];
+		} while ( *d++ != NULL );
+		for(int i=0; i < removedCount; ++i)
+			*d++ = NULL;
+	}
+	
+	// disable framework and library fallback paths for setuid binaries rdar://problem/4589305
+	sEnv.DYLD_FALLBACK_FRAMEWORK_PATH = NULL;
+	sEnv.DYLD_FALLBACK_LIBRARY_PATH = NULL;
+
+	if ( removedCount > 0 )
+		strlcat(sLoadingCrashMessage, ", ignoring DYLD_* env vars", sizeof(sLoadingCrashMessage));
+}
+#endif
+
+static void defaultUninitializedFallbackPaths(const char* envp[])
+{
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+	if ( !gLinkContext.allowClassicFallbackPaths ) {
+		sEnv.DYLD_FALLBACK_FRAMEWORK_PATH = sRestrictedFrameworkFallbackPaths;
+		sEnv.DYLD_FALLBACK_LIBRARY_PATH   = sRestrictedLibraryFallbackPaths;
+		return;
+	}
+
+	// default value for DYLD_FALLBACK_FRAMEWORK_PATH, if not set in environment
+	const char* home = _simple_getenv(envp, "HOME");;
+	if ( sEnv.DYLD_FALLBACK_FRAMEWORK_PATH == NULL ) {
+		const char** fpaths = sFrameworkFallbackPaths;
+		if ( home == NULL )
+			removePathWithPrefix(fpaths, "$HOME");
+		else
+			paths_expand_roots(fpaths, "$HOME", home);
+		sEnv.DYLD_FALLBACK_FRAMEWORK_PATH = fpaths;
+	}
+
+    // default value for DYLD_FALLBACK_LIBRARY_PATH, if not set in environment
+	if ( sEnv.DYLD_FALLBACK_LIBRARY_PATH == NULL ) {
+		const char** lpaths = sLibraryFallbackPaths;
+		if ( home == NULL )
+			removePathWithPrefix(lpaths, "$HOME");
+		else
+			paths_expand_roots(lpaths, "$HOME", home);
+		sEnv.DYLD_FALLBACK_LIBRARY_PATH = lpaths;
+	}
+#else
+	if ( sEnv.DYLD_FALLBACK_FRAMEWORK_PATH == NULL )
+		sEnv.DYLD_FALLBACK_FRAMEWORK_PATH = sFrameworkFallbackPaths;
+
+	if ( sEnv.DYLD_FALLBACK_LIBRARY_PATH == NULL )
+		sEnv.DYLD_FALLBACK_LIBRARY_PATH = sLibraryFallbackPaths;
+#endif
+}
+
+
+static void checkEnvironmentVariables(const char* envp[])
+{
+	if ( !gLinkContext.allowEnvVarsPath && !gLinkContext.allowEnvVarsPrint )
+		return;
 	const char** p;
 	for(p = envp; *p != NULL; p++) {
 		const char* keyEqualsValue = *p;
 	    if ( strncmp(keyEqualsValue, "DYLD_", 5) == 0 ) {
 			const char* equals = strchr(keyEqualsValue, '=');
-			if ( (equals != NULL) && !ignoreEnviron ) {
+			if ( equals != NULL ) {
+				strlcat(sLoadingCrashMessage, "\n", sizeof(sLoadingCrashMessage));
+				strlcat(sLoadingCrashMessage, keyEqualsValue, sizeof(sLoadingCrashMessage));
 				const char* value = &equals[1];
-				const int keyLen = equals-keyEqualsValue;
+				const size_t keyLen = equals-keyEqualsValue;
 				char key[keyLen+1];
 				strncpy(key, keyEqualsValue, keyLen);
 				key[keyLen] = '\0';
-				processDyldEnvironmentVarible(key, value);
-			}
-		}
-	    else if ( strncmp(keyEqualsValue, "HOME=", 5) == 0 ) {
-			home = &keyEqualsValue[5];
+				if ( (strncmp(key, "DYLD_PRINT_", 11) == 0) && !gLinkContext.allowEnvVarsPrint )
+					continue;
+				processDyldEnvironmentVariable(key, value, NULL);
+			}
 		}
 		else if ( strncmp(keyEqualsValue, "LD_LIBRARY_PATH=", 16) == 0 ) {
 			const char* path = &keyEqualsValue[16];
-			if ( !disableIfBadUser((char*)path) )
-				sEnv.LD_LIBRARY_PATH = parseColonList(path);
-		}
-	}
-		
-	// default value for DYLD_FALLBACK_FRAMEWORK_PATH, if not set in environment
-	if ( sEnv.DYLD_FALLBACK_FRAMEWORK_PATH == NULL ) {
-		const char** paths = sFrameworkFallbackPaths;
-		if ( home == NULL )
-			removePathWithPrefix(paths, "$HOME");
-		else
-			paths_expand_roots(paths, "$HOME", home);
-		sEnv.DYLD_FALLBACK_FRAMEWORK_PATH = paths;
-	}
-
-	// default value for DYLD_FALLBACK_LIBRARY_PATH, if not set in environment
-	if ( sEnv.DYLD_FALLBACK_LIBRARY_PATH == NULL ) {
-		const char** paths = sLibraryFallbackPaths;
-		if ( home == NULL ) 
-			removePathWithPrefix(paths, "$HOME");
-		else
-			paths_expand_roots(paths, "$HOME", home);
-		sEnv.DYLD_FALLBACK_LIBRARY_PATH = paths;
-	}
-}
-
-
-static void getHostInfo()
-{
-#if 0
+			sEnv.LD_LIBRARY_PATH = parseColonList(path, NULL);
+		}
+	}
+
+#if SUPPORT_LC_DYLD_ENVIRONMENT
+	checkLoadCommandEnvironmentVariables();
+#endif // SUPPORT_LC_DYLD_ENVIRONMENT	
+	
+#if SUPPORT_ROOT_PATH
+	// <rdar://problem/11281064> DYLD_IMAGE_SUFFIX and DYLD_ROOT_PATH cannot be used together
+	if ( (gLinkContext.imageSuffix != NULL && *gLinkContext.imageSuffix != NULL) && (gLinkContext.rootPaths != NULL) ) {
+		dyld::warn("Ignoring DYLD_IMAGE_SUFFIX because DYLD_ROOT_PATH is used.\n");
+		gLinkContext.imageSuffix = NULL; // this leaks allocations from parseColonList
+	}
+#endif
+}
+
+#if __x86_64__ && !TARGET_IPHONE_SIMULATOR
+static bool isGCProgram(const macho_header* mh, uintptr_t slide)
+{
+	const uint32_t cmd_count = mh->ncmds;
+	const struct load_command* const cmds = (struct load_command*)(((char*)mh)+sizeof(macho_header));
+	const struct load_command* cmd = cmds;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		switch (cmd->cmd) {
+			case LC_SEGMENT_COMMAND:
+			{
+				const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+				if (strcmp(seg->segname, "__DATA") == 0) {
+					const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+					const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
+					for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+						if (strncmp(sect->sectname, "__objc_imageinfo", 16) == 0) {
+							const uint32_t*  objcInfo = (uint32_t*)(sect->addr + slide);
+							return (objcInfo[1] & 6); // 6 = (OBJC_IMAGE_SUPPORTS_GC | OBJC_IMAGE_REQUIRES_GC)
+						}
+					}
+				}
+			}
+			break;
+		}
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+	}
+	return false;
+}
+#endif
+
+static void getHostInfo(const macho_header* mainExecutableMH, uintptr_t mainExecutableSlide)
+{
+#if CPU_SUBTYPES_SUPPORTED
+#if __ARM_ARCH_7K__
+	sHostCPU		= CPU_TYPE_ARM;
+	sHostCPUsubtype = CPU_SUBTYPE_ARM_V7K;
+#elif __ARM_ARCH_7A__
+	sHostCPU		= CPU_TYPE_ARM;
+	sHostCPUsubtype = CPU_SUBTYPE_ARM_V7;
+#elif __ARM_ARCH_6K__
+	sHostCPU		= CPU_TYPE_ARM;
+	sHostCPUsubtype = CPU_SUBTYPE_ARM_V6;
+#elif __ARM_ARCH_7F__
+	sHostCPU		= CPU_TYPE_ARM;
+	sHostCPUsubtype = CPU_SUBTYPE_ARM_V7F;
+#elif __ARM_ARCH_7S__
+	sHostCPU		= CPU_TYPE_ARM;
+	sHostCPUsubtype = CPU_SUBTYPE_ARM_V7S;
+#elif __ARM64_ARCH_8_32__
+	sHostCPU		= CPU_TYPE_ARM64_32;
+	sHostCPUsubtype = CPU_SUBTYPE_ARM64_32_V8;
+#elif __arm64e__
+	sHostCPU		= CPU_TYPE_ARM64;
+	sHostCPUsubtype = CPU_SUBTYPE_ARM64_E;
+#elif __arm64__
+	sHostCPU		= CPU_TYPE_ARM64;
+	sHostCPUsubtype = CPU_SUBTYPE_ARM64_V8;
+#else
 	struct host_basic_info info;
 	mach_msg_type_number_t count = HOST_BASIC_INFO_COUNT;
 	mach_port_t hostPort = mach_host_self();
 	kern_return_t result = host_info(hostPort, HOST_BASIC_INFO, (host_info_t)&info, &count);
-	mach_port_deallocate(mach_task_self(), hostPort);
 	if ( result != KERN_SUCCESS )
 		throw "host_info() failed";
-	
 	sHostCPU		= info.cpu_type;
 	sHostCPUsubtype = info.cpu_subtype;
-#endif
-
-	size_t valSize = sizeof(sHostCPU);
-	if (sysctlbyname ("hw.cputype", &sHostCPU, &valSize, NULL, 0) != 0) 
-		throw "sysctlbyname(hw.cputype) failed";
-	valSize = sizeof(sHostCPUsubtype);
-	if (sysctlbyname ("hw.cpusubtype", &sHostCPUsubtype, &valSize, NULL, 0) != 0) 
-		throw "sysctlbyname(hw.cpusubtype) failed";
-}
-
-bool validImage(ImageLoader* possibleImage)
-{
-	const unsigned int imageCount = sAllImages.size();
-	for(unsigned int i=0; i < imageCount; ++i) {
-		if ( possibleImage == sAllImages[i] ) {
-			return true;
-		}
-	}
+	mach_port_deallocate(mach_task_self(), hostPort);
+  #if __x86_64__
+	  // host_info returns CPU_TYPE_I386 even for x86_64.  Override that here so that
+	  // we don't need to mask the cpu type later.
+	  sHostCPU = CPU_TYPE_X86_64;
+	#if !TARGET_IPHONE_SIMULATOR
+	  sHaswell = (sHostCPUsubtype == CPU_SUBTYPE_X86_64_H);
+	  // <rdar://problem/18528074> x86_64h: Fall back to the x86_64 slice if an app requires GC.
+	  if ( sHaswell ) {
+		if ( isGCProgram(mainExecutableMH, mainExecutableSlide) ) {
+			// When running a GC program on a haswell machine, don't use and 'h slices
+			sHostCPUsubtype = CPU_SUBTYPE_X86_64_ALL;
+			sHaswell = false;
+			gLinkContext.sharedRegionMode = ImageLoader::kDontUseSharedRegion;
+		}
+	  }
+	#endif
+  #endif
+#endif
+#endif
+}
+
+static void checkSharedRegionDisable(const dyld3::MachOLoaded* mainExecutableMH, uintptr_t mainExecutableSlide)
+{
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+	// if main executable has segments that overlap the shared region,
+	// then disable using the shared region
+	if ( mainExecutableMH->intersectsRange(SHARED_REGION_BASE, SHARED_REGION_SIZE) ) {
+		gLinkContext.sharedRegionMode = ImageLoader::kDontUseSharedRegion;
+		if ( gLinkContext.verboseMapping )
+			dyld::warn("disabling shared region because main executable overlaps\n");
+	}
+#if __i386__
+	if ( !gLinkContext.allowEnvVarsPath ) {
+		// <rdar://problem/15280847> use private or no shared region for suid processes
+		gLinkContext.sharedRegionMode = ImageLoader::kUsePrivateSharedRegion;
+	}
+#endif
+#endif
+	// iOS cannot run without shared region
+}
+
+bool validImage(const ImageLoader* possibleImage)
+{
+    const size_t imageCount = sAllImages.size();
+    for(size_t i=0; i < imageCount; ++i) {
+        if ( possibleImage == sAllImages[i] ) {
+            return true;
+        }
+    }
 	return false;
 }
 
 uint32_t getImageCount()
 {
-	if ( sAllImagesMightContainUnlinkedImages ) {
-		uint32_t count = 0;
-		for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
-			if ( (*it)->isLinked() )
-				++count;
-		}
-		return count;
-	}
-	else {
-		return sAllImages.size();
-	}
+	return (uint32_t)sAllImages.size();
 }
 
 ImageLoader* getIndexedImage(unsigned int index)
 {
-	if ( sAllImagesMightContainUnlinkedImages ) {
-		uint32_t count = 0;
-		for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
-			if ( (*it)->isLinked() ) {
-				if ( index == count )
-					return *it;
-				++count;
-			}
-		}
-	}
-	else {
-		if ( index < sAllImages.size() )
-			return sAllImages[index];
-	}
+	if ( index < sAllImages.size() )
+		return sAllImages[index];
 	return NULL;
 }
 
 ImageLoader* findImageByMachHeader(const struct mach_header* target)
 {
-	const unsigned int imageCount = sAllImages.size();
-	for(unsigned int i=0; i < imageCount; ++i) {
-		ImageLoader* anImage = sAllImages[i];
-		if ( anImage->machHeader() == target )
+	return findMappedRange((uintptr_t)target);
+}
+
+
+ImageLoader* findImageContainingAddress(const void* addr)
+{
+  #if SUPPORT_ACCELERATE_TABLES
+	if ( sAllCacheImagesProxy != NULL ) {
+		const mach_header* mh;
+		const char* path;
+		unsigned index;
+		if ( sAllCacheImagesProxy->addressInCache(addr, &mh, &path, &index) )
+			return sAllCacheImagesProxy;
+	}
+  #endif
+	return findMappedRange((uintptr_t)addr);
+}
+
+
+ImageLoader* findImageContainingSymbol(const void* symbol)
+{
+	for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+		ImageLoader* anImage = *it;
+		if ( anImage->containsSymbol(symbol) )
 			return anImage;
 	}
 	return NULL;
 }
 
 
-ImageLoader* findImageContainingAddress(const void* addr)
-{
-#if FIND_STATS	
-	static int cacheHit = 0; 
-	static int cacheMiss = 0; 
-	static int cacheNotMacho = 0; 
-	if ( ((cacheHit+cacheMiss+cacheNotMacho) % 100) == 0 )
-		fprintf(stderr, "findImageContainingAddress(): cache hit = %d, miss = %d, unknown = %d\n", cacheHit, cacheMiss, cacheNotMacho);
-#endif
-	// first look in image where last address was found rdar://problem/3685517
-	if ( (sLastImageByAddressCache != NULL) && sLastImageByAddressCache->containsAddress(addr) ) {
-#if FIND_STATS	
-		++cacheHit;
-#endif
-		return sLastImageByAddressCache;
-	}
-	// do exhastive search 
-	// todo: consider maintaining a list sorted by address ranges and do a binary search on that
-	const unsigned int imageCount = sAllImages.size();
-	for(unsigned int i=0; i < imageCount; ++i) {
-		ImageLoader* anImage = sAllImages[i];
-		if ( anImage->containsAddress(addr) ) {
-			sLastImageByAddressCache = anImage;
-#if FIND_STATS	
-		++cacheMiss;
-#endif
-			return anImage;
-		}
-	}
-#if FIND_STATS	
-		++cacheNotMacho;
-#endif
-	return NULL;
-}
-
-ImageLoader* findImageContainingAddressThreadSafe(const void* addr)
-{
-	// do exhastive search 
-	// todo: consider maintaining a list sorted by address ranges and do a binary search on that
-	const unsigned int imageCount = sAllImages.size();
-	for(unsigned int i=0; i < imageCount; ++i) {
-		ImageLoader* anImage = sAllImages[i];
-		if ( anImage->containsAddress(addr) ) {
-			return anImage;
-		}
-	}
-	return NULL;
-}
-
 
 void forEachImageDo( void (*callback)(ImageLoader*, void* userData), void* userData)
 {
-	const unsigned int imageCount = sAllImages.size();
-	for(unsigned int i=0; i < imageCount; ++i) {
+	const size_t imageCount = sAllImages.size();
+	for(size_t i=0; i < imageCount; ++i) {
 		ImageLoader* anImage = sAllImages[i];
 		(*callback)(anImage, userData);
 	}
@@ -844,8 +2386,8 @@
 
 ImageLoader* findLoadedImage(const struct stat& stat_buf)
 {
-	const unsigned int imageCount = sAllImages.size();
-	for(unsigned int i=0; i < imageCount; ++i){
+	const size_t imageCount = sAllImages.size();
+	for(size_t i=0; i < imageCount; ++i){
 		ImageLoader* anImage = sAllImages[i];
 		if ( anImage->statMatch(stat_buf) )
 			return anImage;
@@ -856,7 +2398,7 @@
 // based on ANSI-C strstr()
 static const char* strrstr(const char* str, const char* sub) 
 {
-	const int sublen = strlen(sub);
+	const size_t sublen = strlen(sub);
 	for(const char* p = &str[strlen(str)]; p != str; --p) {
 		if ( strncmp(p, sub, sublen) == 0 )
 			return p;
@@ -886,7 +2428,7 @@
 				const char* frameworkStart = &dirStart[1];
 				if ( dirStart == path )
 					--frameworkStart;
-				int len = dirDot - frameworkStart;
+				size_t len = dirDot - frameworkStart;
 				char framework[len+1];
 				strncpy(framework, frameworkStart, len);
 				framework[len] = '\0';
@@ -898,8 +2440,10 @@
 					if (  gLinkContext.imageSuffix != NULL ) {
 						// some debug frameworks have install names that end in _debug
 						if ( strncmp(framework, &leaf[1], len) == 0 ) {
-							if ( strcmp( gLinkContext.imageSuffix, &leaf[len+1]) == 0 )
-								return frameworkStart;
+							for (const char* const* suffix=gLinkContext.imageSuffix; *suffix != NULL; ++suffix) {
+								if ( strcmp(*suffix, &leaf[len+1]) == 0 )
+									return frameworkStart;
+							}
 						}
 					}
 				}
@@ -920,6 +2464,8 @@
 }
 
 
+// only for architectures that use cpu-sub-types
+#if CPU_SUBTYPES_SUPPORTED 
 
 const cpu_subtype_t CPU_SUBTYPE_END_OF_LIST = -1;
 
@@ -937,60 +2483,122 @@
 //
 
 
-//	 
-//	32-bit PowerPC sub-type lists
+#if __arm__
+//      
+//     ARM sub-type lists
 //
-const int kPPC_RowCount = 4;
-static const cpu_subtype_t kPPC32[kPPC_RowCount][6] = { 
-	// G5 can run any code
-	{  CPU_SUBTYPE_POWERPC_970, CPU_SUBTYPE_POWERPC_7450,  CPU_SUBTYPE_POWERPC_7400, CPU_SUBTYPE_POWERPC_750, CPU_SUBTYPE_POWERPC_ALL, CPU_SUBTYPE_END_OF_LIST },
+const int kARM_RowCount = 8;
+static const cpu_subtype_t kARM[kARM_RowCount][9] = { 
+
+	// armv7f can run: v7f, v7, v6, v5, and v4
+	{  CPU_SUBTYPE_ARM_V7F, CPU_SUBTYPE_ARM_V7, CPU_SUBTYPE_ARM_V6, CPU_SUBTYPE_ARM_V5TEJ, CPU_SUBTYPE_ARM_V4T, CPU_SUBTYPE_ARM_ALL, CPU_SUBTYPE_END_OF_LIST },
+
+	// armv7k can run: v7k
+	{  CPU_SUBTYPE_ARM_V7K, CPU_SUBTYPE_END_OF_LIST },
+
+	// armv7s can run: v7s, v7, v7f, v7k, v6, v5, and v4
+	{  CPU_SUBTYPE_ARM_V7S, CPU_SUBTYPE_ARM_V7, CPU_SUBTYPE_ARM_V7F, CPU_SUBTYPE_ARM_V6, CPU_SUBTYPE_ARM_V5TEJ, CPU_SUBTYPE_ARM_V4T, CPU_SUBTYPE_ARM_ALL, CPU_SUBTYPE_END_OF_LIST },
+
+	// armv7 can run: v7, v6, v5, and v4
+	{  CPU_SUBTYPE_ARM_V7, CPU_SUBTYPE_ARM_V6, CPU_SUBTYPE_ARM_V5TEJ, CPU_SUBTYPE_ARM_V4T, CPU_SUBTYPE_ARM_ALL, CPU_SUBTYPE_END_OF_LIST },
 	
-	// G4 can run all but G5 code
-	{  CPU_SUBTYPE_POWERPC_7450,  CPU_SUBTYPE_POWERPC_7400,  CPU_SUBTYPE_POWERPC_750, CPU_SUBTYPE_POWERPC_ALL, CPU_SUBTYPE_END_OF_LIST, CPU_SUBTYPE_END_OF_LIST },
-	{  CPU_SUBTYPE_POWERPC_7400,  CPU_SUBTYPE_POWERPC_7450,  CPU_SUBTYPE_POWERPC_750, CPU_SUBTYPE_POWERPC_ALL, CPU_SUBTYPE_END_OF_LIST, CPU_SUBTYPE_END_OF_LIST },
-
-	// G3 cannot run G4 or G5 code
-	{ CPU_SUBTYPE_POWERPC_750,  CPU_SUBTYPE_POWERPC_ALL, CPU_SUBTYPE_END_OF_LIST,  CPU_SUBTYPE_END_OF_LIST, CPU_SUBTYPE_END_OF_LIST, CPU_SUBTYPE_END_OF_LIST }
+	// armv6 can run: v6, v5, and v4
+	{  CPU_SUBTYPE_ARM_V6, CPU_SUBTYPE_ARM_V5TEJ, CPU_SUBTYPE_ARM_V4T, CPU_SUBTYPE_ARM_ALL, CPU_SUBTYPE_END_OF_LIST, CPU_SUBTYPE_END_OF_LIST },
+	
+	// xscale can run: xscale, v5, and v4
+	{  CPU_SUBTYPE_ARM_XSCALE, CPU_SUBTYPE_ARM_V5TEJ, CPU_SUBTYPE_ARM_V4T, CPU_SUBTYPE_ARM_ALL, CPU_SUBTYPE_END_OF_LIST, CPU_SUBTYPE_END_OF_LIST },
+	
+	// armv5 can run: v5 and v4
+	{  CPU_SUBTYPE_ARM_V5TEJ, CPU_SUBTYPE_ARM_V4T, CPU_SUBTYPE_ARM_ALL, CPU_SUBTYPE_END_OF_LIST, CPU_SUBTYPE_END_OF_LIST, CPU_SUBTYPE_END_OF_LIST },
+
+	// armv4 can run: v4
+	{  CPU_SUBTYPE_ARM_V4T, CPU_SUBTYPE_ARM_ALL, CPU_SUBTYPE_END_OF_LIST, CPU_SUBTYPE_END_OF_LIST, CPU_SUBTYPE_END_OF_LIST, CPU_SUBTYPE_END_OF_LIST },
 };
-
-
-//	 
-//	64-bit PowerPC sub-type lists
+#endif
+
+#if __arm64__
 //
-const int kPPC64_RowCount = 1;
-static const cpu_subtype_t kPPC64[kPPC64_RowCount][3] = { 
-	// G5 can run any 64-bit code
-	{  CPU_SUBTYPE_POWERPC_970, CPU_SUBTYPE_POWERPC_ALL, CPU_SUBTYPE_END_OF_LIST },
+//     ARM64 sub-type lists
+//
+const int kARM64_RowCount = 2;
+static const cpu_subtype_t kARM64[kARM64_RowCount][4] = {
+
+	// armv64e can run: 64e, 64
+	{  CPU_SUBTYPE_ARM64_E, CPU_SUBTYPE_ARM64_V8, CPU_SUBTYPE_ARM64_ALL, CPU_SUBTYPE_END_OF_LIST },
+
+	// armv64 can run: 64
+	{  CPU_SUBTYPE_ARM64_V8, CPU_SUBTYPE_ARM64_ALL, CPU_SUBTYPE_END_OF_LIST },
 };
 
-
-
-//	 
-//	32-bit x86 sub-type lists
+#if __ARM64_ARCH_8_32__
+const int kARM64_32_RowCount = 2;
+static const cpu_subtype_t kARM64_32[kARM64_32_RowCount][4] = {
+
+	// armv64_32 can run: v8
+	{  CPU_SUBTYPE_ARM64_32_V8, CPU_SUBTYPE_END_OF_LIST },
+
+	// armv64 can run: 64
+	{  CPU_SUBTYPE_ARM64_V8, CPU_SUBTYPE_ARM64_ALL, CPU_SUBTYPE_END_OF_LIST },
+};
+#endif
+	
+#endif
+
+#if __x86_64__
+//      
+//     x86_64 sub-type lists
 //
-//	TO-DO
-
+const int kX86_64_RowCount = 2;
+static const cpu_subtype_t kX86_64[kX86_64_RowCount][5] = {
+
+	// x86_64h can run: x86_64h, x86_64h(lib), x86_64(lib), and x86_64
+	{ CPU_SUBTYPE_X86_64_H, (cpu_subtype_t)(CPU_SUBTYPE_LIB64|CPU_SUBTYPE_X86_64_H), (cpu_subtype_t)(CPU_SUBTYPE_LIB64|CPU_SUBTYPE_X86_64_ALL), CPU_SUBTYPE_X86_64_ALL,  CPU_SUBTYPE_END_OF_LIST },
+
+	// x86_64 can run: x86_64(lib) and x86_64
+	{ CPU_SUBTYPE_X86_64_ALL, (cpu_subtype_t)(CPU_SUBTYPE_LIB64|CPU_SUBTYPE_X86_64_ALL), CPU_SUBTYPE_END_OF_LIST },
+
+};
+#endif
 
 
 // scan the tables above to find the cpu-sub-type-list for this machine
 static const cpu_subtype_t* findCPUSubtypeList(cpu_type_t cpu, cpu_subtype_t subtype)
 {
 	switch (cpu) {
-		case CPU_TYPE_POWERPC:
-			for (int i=0; i < kPPC_RowCount ; ++i) {
-				if ( kPPC32[i][0] == subtype )
-					return kPPC32[i];
+#if __arm__
+		case CPU_TYPE_ARM:
+			for (int i=0; i < kARM_RowCount ; ++i) {
+				if ( kARM[i][0] == subtype )
+					return kARM[i];
 			}
 			break;
-		case CPU_TYPE_POWERPC64:
-			for (int i=0; i < kPPC64_RowCount ; ++i) {
-				if ( kPPC64[i][0] == subtype )
-					return kPPC64[i];
+#endif
+#if __arm64__
+		case CPU_TYPE_ARM64:
+			for (int i=0; i < kARM64_RowCount ; ++i) {
+				if ( kARM64[i][0] == subtype )
+					return kARM64[i];
 			}
 			break;
-		case CPU_TYPE_I386:
-			// To do 
+
+#if __ARM64_ARCH_8_32__
+		case CPU_TYPE_ARM64_32:
+			for (int i=0; i < kARM64_32_RowCount ; ++i) {
+				if ( kARM64_32[i][0] == subtype )
+					return kARM64_32[i];
+			}
 			break;
+#endif
+
+#endif
+#if __x86_64__
+		case CPU_TYPE_X86_64:
+			for (int i=0; i < kX86_64_RowCount ; ++i) {
+				if ( kX86_64[i][0] == subtype )
+					return kX86_64[i];
+			}
+			break;
+#endif
 	}
 	return NULL;
 }
@@ -1005,7 +2613,7 @@
 	for (uint32_t subTypeIndex=0; list[subTypeIndex] != CPU_SUBTYPE_END_OF_LIST; ++subTypeIndex) {
 		for(uint32_t fatIndex=0; fatIndex < OSSwapBigToHostInt32(fh->nfat_arch); ++fatIndex) {
 			if ( ((cpu_type_t)OSSwapBigToHostInt32(archs[fatIndex].cputype) == cpu) 
-				&& (list[subTypeIndex] == archs[fatIndex].cpusubtype) ) {
+				&& (list[subTypeIndex] == (cpu_subtype_t)OSSwapBigToHostInt32(archs[fatIndex].cpusubtype)) ) {
 				*offset = OSSwapBigToHostInt32(archs[fatIndex].offset);
 				*len = OSSwapBigToHostInt32(archs[fatIndex].size);
 				return true;
@@ -1037,27 +2645,100 @@
 	for(uint32_t i=0; i < OSSwapBigToHostInt32(fh->nfat_arch); ++i) {
 		if ( (cpu_type_t)OSSwapBigToHostInt32(archs[i].cputype) == cpu) {
 			switch (cpu) {
-				case CPU_TYPE_POWERPC:
-				case CPU_TYPE_POWERPC64:
-					if ( (cpu_subtype_t)OSSwapBigToHostInt32(archs[i].cpusubtype) == CPU_SUBTYPE_POWERPC_ALL ) {
+#if __arm__
+				case CPU_TYPE_ARM:
+					if ( (cpu_subtype_t)OSSwapBigToHostInt32(archs[i].cpusubtype) == CPU_SUBTYPE_ARM_ALL ) {
 						*offset = OSSwapBigToHostInt32(archs[i].offset);
 						*len = OSSwapBigToHostInt32(archs[i].size);
 						return true;
 					}
 					break;
-				case CPU_TYPE_I386:
-					if ( (cpu_subtype_t)OSSwapBigToHostInt32(archs[i].cpusubtype) == CPU_SUBTYPE_I386_ALL ) {
+#endif
+#if __arm64__
+				case CPU_TYPE_ARM64:
+					if ( (cpu_subtype_t)OSSwapBigToHostInt32(archs[i].cpusubtype) == CPU_SUBTYPE_ARM64_ALL ) {
 						*offset = OSSwapBigToHostInt32(archs[i].offset);
 						*len = OSSwapBigToHostInt32(archs[i].size);
 						return true;
 					}
 					break;
+#endif
+#if __x86_64__
+				case CPU_TYPE_X86_64:
+					if ( (cpu_subtype_t)OSSwapBigToHostInt32(archs[i].cpusubtype) == CPU_SUBTYPE_X86_64_ALL ) {
+						*offset = OSSwapBigToHostInt32(archs[i].offset);
+						*len = OSSwapBigToHostInt32(archs[i].size);
+						return true;
+					}
+					break;
+#endif
 			}
 		}
 	}
 	return false;
 }
 
+#endif // CPU_SUBTYPES_SUPPORTED
+
+
+//
+// Validate the fat_header and fat_arch array:
+//
+// 1) arch count would not cause array to extend past 4096 byte read buffer
+// 2) no slice overlaps the fat_header and arch array
+// 3) arch list does not contain duplicate cputype/cpusubtype tuples
+// 4) arch list does not have two overlapping slices.
+//
+static bool fatValidate(const fat_header* fh)
+{
+	if ( fh->magic != OSSwapBigToHostInt32(FAT_MAGIC) )
+		return false;
+
+	// since only first 4096 bytes of file read, we can only handle up to 204 slices.
+	const uint32_t sliceCount = OSSwapBigToHostInt32(fh->nfat_arch);
+	if ( sliceCount > 204 )
+		return false;
+
+	// compare all slices looking for conflicts
+	const fat_arch* archs = (fat_arch*)(((char*)fh)+sizeof(fat_header));
+	for (uint32_t i=0; i < sliceCount; ++i) {
+		uint32_t i_offset     = OSSwapBigToHostInt32(archs[i].offset);
+		uint32_t i_size       = OSSwapBigToHostInt32(archs[i].size);
+		uint32_t i_cputype    = OSSwapBigToHostInt32(archs[i].cputype);
+		uint32_t i_cpusubtype = OSSwapBigToHostInt32(archs[i].cpusubtype);
+		uint32_t i_end        = i_offset + i_size;
+		// slice cannot overlap with header
+		if ( i_offset < 4096 )
+			return false;
+		// slice size cannot overflow
+		if ( i_end < i_offset )
+			return false;
+		for (uint32_t j=i+1; j < sliceCount; ++j) {
+			uint32_t j_offset     = OSSwapBigToHostInt32(archs[j].offset);
+			uint32_t j_size       = OSSwapBigToHostInt32(archs[j].size);
+			uint32_t j_cputype    = OSSwapBigToHostInt32(archs[j].cputype);
+			uint32_t j_cpusubtype = OSSwapBigToHostInt32(archs[j].cpusubtype);
+			uint32_t j_end        = j_offset + j_size;
+			// duplicate slices types not allowed
+			if ( (i_cputype == j_cputype) && (i_cpusubtype == j_cpusubtype) )
+				return false;
+			// slice size cannot overflow
+			if ( j_end < j_offset )
+				return false;
+			// check for overlap of slices
+			if ( i_offset <= j_offset ) {
+				if ( j_offset < i_end )
+					return false; //  j overlaps end of i
+			}
+			else {
+				//  j overlaps end of i
+				if ( i_offset < j_end )
+					return false;  //  i overlaps end of j
+			}
+		}
+	}
+	return true;
+}
 
 //
 // A fat file may contain multiple sub-images for the same cpu-type,
@@ -1066,18 +2747,24 @@
 //
 static bool fatFindBest(const fat_header* fh, uint64_t* offset, uint64_t* len)
 {
+	if ( !fatValidate(fh) )
+		return false;
+
+#if CPU_SUBTYPES_SUPPORTED
 	// assume all dylibs loaded must have same cpu type as main executable
 	const cpu_type_t cpu = sMainExecutableMachHeader->cputype;
 
 	// We only know the subtype to use if the main executable cpu type matches the host
-	if ( (cpu & CPU_TYPE_MASK) == sHostCPU ) {
+	if ( cpu == sHostCPU ) {
 		// get preference ordered list of subtypes
 		const cpu_subtype_t* subTypePreferenceList = findCPUSubtypeList(cpu, sHostCPUsubtype);
 	
 		// use ordered list to find best sub-image in fat file
-		if ( subTypePreferenceList != NULL ) 
-			return fatFindBestFromOrderedList(cpu, subTypePreferenceList, fh, offset, len);
-		
+		if ( subTypePreferenceList != NULL ) {
+			if ( fatFindBestFromOrderedList(cpu, subTypePreferenceList, fh, offset, len) )
+				return true;
+		}
+
 		// if running cpu is not in list, try for an exact match
 		if ( fatFindExactMatch(cpu, sHostCPUsubtype, fh, offset, len) )
 			return true;
@@ -1085,24 +2772,36 @@
 	
 	// running on an uknown cpu, can only load generic code
 	return fatFindRunsOnAllCPUs(cpu, fh, offset, len);
+#else
+	// just find first slice with matching architecture
+	const fat_arch* archs = (fat_arch*)(((char*)fh)+sizeof(fat_header));
+	for(uint32_t i=0; i < OSSwapBigToHostInt32(fh->nfat_arch); ++i) {
+		if ( (cpu_type_t)OSSwapBigToHostInt32(archs[i].cputype) == sMainExecutableMachHeader->cputype) {
+			*offset = OSSwapBigToHostInt32(archs[i].offset);
+			*len = OSSwapBigToHostInt32(archs[i].size);
+			return true;
+		}
+	}
+	return false;
+#endif
 }
 
 
 
 //
 // This is used to validate if a non-fat (aka thin or raw) mach-o file can be used
-// on the current processor.  It is deemed compatible if any of the following are true:
-//  1) mach_header subtype is in list of compatible subtypes for running processor
-//  2) mach_header subtype is same as running processor subtype
-//  3) mach_header subtype runs on all processor variants
-//
-//
-bool isCompatibleMachO(const uint8_t* firstPage)
-{
+// on the current processor. //
+bool isCompatibleMachO(const uint8_t* firstPage, const char* path)
+{
+#if CPU_SUBTYPES_SUPPORTED
+	// It is deemed compatible if any of the following are true:
+	//  1) mach_header subtype is in list of compatible subtypes for running processor
+	//  2) mach_header subtype is same as running processor subtype
+	//  3) mach_header subtype runs on all processor variants
 	const mach_header* mh = (mach_header*)firstPage;
 	if ( mh->magic == sMainExecutableMachHeader->magic ) {
 		if ( mh->cputype == sMainExecutableMachHeader->cputype ) {
-			if ( (mh->cputype & CPU_TYPE_MASK) == sHostCPU ) {
+			if ( mh->cputype == sHostCPU ) {
 				// get preference ordered list of subtypes that this machine can use
 				const cpu_subtype_t* subTypePreferenceList = findCPUSubtypeList(mh->cputype, sHostCPUsubtype);
 				if ( subTypePreferenceList != NULL ) {
@@ -1112,77 +2811,282 @@
 							return true;
 					}
 					// have list and not in list, so not compatible
-					throw "incompatible cpu-subtype";
+					throwf("incompatible cpu-subtype: 0x%08X in %s", mh->cpusubtype, path);
 				}
 				// unknown cpu sub-type, but if exact match for current subtype then ok to use
 				if ( mh->cpusubtype == sHostCPUsubtype ) 
 					return true;
 			}
 			
-			// cpu unknown, so don't know if subtype is compatible
-			// only load _ALL variant
+			// cpu type has no ordered list of subtypes
 			switch (mh->cputype) {
-				case CPU_TYPE_POWERPC:
-				case CPU_TYPE_POWERPC64:
-					if ( mh->cpusubtype == CPU_SUBTYPE_POWERPC_ALL ) 
-						return true;
-					break;
 				case CPU_TYPE_I386:
-					if ( mh->cpusubtype == CPU_SUBTYPE_I386_ALL ) 
-						return true;
-					break;					
-			}
-		}
-	}
+				case CPU_TYPE_X86_64:
+					// subtypes are not used or these architectures
+					return true;
+			}
+		}
+	}
+#else
+	// For architectures that don't support cpu-sub-types
+	// this just check the cpu type.
+	const mach_header* mh = (mach_header*)firstPage;
+	if ( mh->magic == sMainExecutableMachHeader->magic ) {
+		if ( mh->cputype == sMainExecutableMachHeader->cputype ) {
+			return true;
+		}
+	}
+#endif
 	return false;
 }
+
+
 
 
 // The kernel maps in main executable before dyld gets control.  We need to 
 // make an ImageLoader* for the already mapped in main executable.
-static ImageLoader* instantiateFromLoadedImage(const struct mach_header* mh, const char* path)
+static ImageLoaderMachO* instantiateFromLoadedImage(const macho_header* mh, uintptr_t slide, const char* path)
 {
 	// try mach-o loader
-	if ( isCompatibleMachO((const uint8_t*)mh) ) {
-		ImageLoader* image = new ImageLoaderMachO(path, mh, 0, gLinkContext);
+	if ( isCompatibleMachO((const uint8_t*)mh, path) ) {
+		ImageLoader* image = ImageLoaderMachO::instantiateMainExecutable(mh, slide, path, gLinkContext);
 		addImage(image);
-		return image;
+		return (ImageLoaderMachO*)image;
 	}
 	
 	throw "main executable not a known format";
 }
 
-
-
+#if SUPPORT_ACCELERATE_TABLES
+static bool dylibsCanOverrideCache()
+{
+	if ( !dyld3::internalInstall() )
+		return false;
+	return ( (sSharedCacheLoadInfo.loadAddress != nullptr) && (sSharedCacheLoadInfo.loadAddress->header.cacheType == kDyldSharedCacheTypeDevelopment) );
+}
+#endif
+
+const void* imMemorySharedCacheHeader()
+{
+	return sSharedCacheLoadInfo.loadAddress;
+}
+
+
+const char* getStandardSharedCacheFilePath()
+{
+	if ( sSharedCacheLoadInfo.loadAddress != nullptr )
+		return sSharedCacheLoadInfo.path;
+	else
+		return nullptr;
+}
+
+
+static bool findInSharedCacheImage(const char* path, bool searchByPath, const struct stat* stat_buf, const macho_header** mh, const char** pathInCache, long* slide)
+{
+	dyld3::SharedCacheFindDylibResults results;
+	if ( dyld3::findInSharedCacheImage(sSharedCacheLoadInfo, path, &results) ) {
+		*mh			 = (macho_header*)results.mhInCache;
+		*pathInCache = results.pathInCache;
+		*slide	     = results.slideInCache;
+		return true;
+	}
+	return false;
+}
+
+bool inSharedCache(const char* path)
+{
+	return dyld3::pathIsInSharedCacheImage(sSharedCacheLoadInfo, path);
+}
+
+
+static ImageLoader* checkandAddImage(ImageLoader* image, const LoadContext& context)
+{
+	// now sanity check that this loaded image does not have the same install path as any existing image
+	const char* loadedImageInstallPath = image->getInstallPath();
+	if ( image->isDylib() && (loadedImageInstallPath != NULL) && (loadedImageInstallPath[0] == '/') ) {
+		for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+			ImageLoader* anImage = *it;
+			const char* installPath = anImage->getInstallPath();
+			if ( installPath != NULL) {
+				if ( strcmp(loadedImageInstallPath, installPath) == 0 ) {
+					//dyld::log("duplicate(%s) => %p\n", installPath, anImage);
+					removeImage(image);
+					ImageLoader::deleteImage(image);
+					return anImage;
+				}
+			}
+		}
+	}
+
+	// some API's restrict what they can load
+	if ( context.mustBeBundle && !image->isBundle() )
+		throw "not a bundle";
+	if ( context.mustBeDylib && !image->isDylib() )
+		throw "not a dylib";
+
+	// regular main executables cannot be loaded 
+	if ( image->isExecutable() ) {
+		if ( !context.canBePIE || !image->isPositionIndependentExecutable() )
+			throw "can't load a main executable";
+	}
+	
+	// don't add bundles to global list, they can be loaded but not linked.  When linked it will be added to list
+	if ( ! image->isBundle() ) 
+		addImage(image);
+	
+	return image;
+}
+
+#if TARGET_IPHONE_SIMULATOR	
+static bool isSimulatorBinary(const uint8_t* firstPages, const char* path)
+{
+	const macho_header* mh = (macho_header*)firstPages;
+	const uint32_t cmd_count = mh->ncmds;
+	const load_command* const cmds = (struct load_command*)(((char*)mh)+sizeof(macho_header));
+	const load_command* const cmdsEnd = (load_command*)((char*)cmds + mh->sizeofcmds);
+	const struct load_command* cmd = cmds;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		switch (cmd->cmd) {
+	#if TARGET_OS_WATCH
+			case LC_VERSION_MIN_WATCHOS:
+				return true;
+	#elif TARGET_OS_TV
+			case LC_VERSION_MIN_TVOS:
+				return true;
+	#elif TARGET_OS_IOS
+			case LC_VERSION_MIN_IPHONEOS:
+				return true;
+	#endif
+			case LC_VERSION_MIN_MACOSX:
+				// grandfather in a few libSystem dylibs
+				if ((strcmp(path, "/usr/lib/system/libsystem_kernel.dylib") == 0) ||
+				    (strcmp(path, "/usr/lib/system/libsystem_platform.dylib") == 0) ||
+				    (strcmp(path, "/usr/lib/system/libsystem_pthread.dylib") == 0) ||
+				    (strcmp(path, "/usr/lib/system/libsystem_platform_debug.dylib") == 0) ||
+				    (strcmp(path, "/usr/lib/system/libsystem_pthread_debug.dylib")  == 0))
+					return true;
+				return false;
+			case LC_BUILD_VERSION:
+			{
+				// Same logic as above, but for LC_BUILD_VERSION instead of legacy load commands
+				const struct build_version_command* buildVersionCmd = (build_version_command*)cmd;
+				switch(buildVersionCmd->platform) {
+					case PLATFORM_IOSSIMULATOR:
+					case PLATFORM_TVOSSIMULATOR:
+					case PLATFORM_WATCHOSSIMULATOR:
+					case PLATFORM_WATCHOS:
+						return true;
+	#if TARGET_OS_IOSMAC
+					case 6:
+						return true;
+	#endif
+					case PLATFORM_MACOS:
+						if ((strcmp(path, "/usr/lib/system/libsystem_kernel.dylib") == 0) ||
+							(strcmp(path, "/usr/lib/system/libsystem_platform.dylib") == 0) ||
+							(strcmp(path, "/usr/lib/system/libsystem_pthread.dylib") == 0) ||
+							(strcmp(path, "/usr/lib/system/libsystem_platform_debug.dylib") == 0) ||
+							(strcmp(path, "/usr/lib/system/libsystem_pthread_debug.dylib")  == 0))
+							return true;
+				}
+			}
+		}
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+		if ( cmd > cmdsEnd )
+			return false;
+	}
+	return false;
+}
+#endif
+
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+static bool iOSMacWhiteListed(const char* path)
+{
+	static char*  whiteListBuffer 	= nullptr;
+	static size_t whiteListSize 	= 0;
+	static bool   tried 			= false;
+	if ( !tried ) {
+		// only try to map file once
+		whiteListBuffer = (char*)mapFileReadOnly("/System/iOSSupport/dyld/macOS-whitelist.txt", whiteListSize);
+		tried = true;
+	}
+	__block bool result = false;
+	if ( whiteListBuffer != nullptr ) {
+		dyld3::forEachLineInFile(whiteListBuffer, whiteListSize, ^(const char* line, bool& stop) {
+			// lines in the file are prefixes.  Any path that starts with one of these lines is allowed to be unzippered
+			size_t lineLen = strlen(line);
+			if ( (*line == '/') && strncmp(line, path, lineLen) == 0 ) {
+				result = true;
+				stop = true;
+			}
+		});
+	}
+	return result;
+}
+
+static bool iOSMacBlackListed(const char* path)
+{
+	static char*  blackListBuffer 	= nullptr;
+	static size_t blackListSize 	= 0;
+	static bool   tried 			= false;
+	if ( !tried ) {
+		// only try to map file once
+		blackListBuffer = (char*)mapFileReadOnly("/System/iOSSupport/dyld/macOS-blacklist.txt", blackListSize);
+		tried = true;
+	}
+	__block bool result = false;
+	if ( blackListBuffer != nullptr ) {
+		dyld3::forEachLineInFile(blackListBuffer, blackListSize, ^(const char* line, bool& stop) {
+			// lines in the file are prefixes.  Any path that starts with one of these lines is allowed to be unzippered
+			size_t lineLen = strlen(line);
+			if ( (*line == '/') && strncmp(line, path, lineLen) == 0 ) {
+				result = true;
+				stop = true;
+			}
+		});
+	}
+	return result;
+}
+
+
+#endif
 
 // map in file and instantiate an ImageLoader
-static ImageLoader* loadPhase6(int fd, struct stat& stat_buf, const char* path, const LoadContext& context)
-{
-	//fprintf(stderr, "%s(%s)\n", __func__ , path);
+static ImageLoader* loadPhase6(int fd, const struct stat& stat_buf, const char* path, const LoadContext& context)
+{
+	//dyld::log("%s(%s)\n", __func__ , path);
 	uint64_t fileOffset = 0;
 	uint64_t fileLength = stat_buf.st_size;
-#if __ppc64__
-	if ( *((uint32_t*)((char*)(&stat_buf)+0x60)) == 0xFEFEFEFE )
-		fileLength = *((uint64_t*)((char*)(&stat_buf)+0x30));	// HACK work around for kernel stat bug rdar://problem/3845883
-#endif
 
 	// validate it is a file (not directory)
 	if ( (stat_buf.st_mode & S_IFMT) != S_IFREG ) 
 		throw "not a file";
 
-	// min file is 4K
+	uint8_t firstPages[MAX_MACH_O_HEADER_AND_LOAD_COMMANDS_SIZE];
+	uint8_t *firstPagesPtr = firstPages;
+	bool shortPage = false;
+	
+	// min mach-o file is 4K
 	if ( fileLength < 4096 ) {
-		throw "file to short";
-	}
-	
-	uint8_t firstPage[4096];
-	pread(fd, firstPage, 4096,0);
+		if ( pread(fd, firstPages, (size_t)fileLength, 0) != (ssize_t)fileLength )
+			throwf("pread of short file failed: %d", errno);
+		shortPage = true;
+	} 
+	else {
+		// optimistically read only first 4KB
+		if ( pread(fd, firstPages, 4096, 0) != 4096 )
+			throwf("pread of first 4K failed: %d", errno);
+	}
 	
 	// if fat wrapper, find usable sub-file
-	const fat_header* fileStartAsFat = (fat_header*)firstPage;
+	const fat_header* fileStartAsFat = (fat_header*)firstPages;
 	if ( fileStartAsFat->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
+		if ( OSSwapBigToHostInt32(fileStartAsFat->nfat_arch) > ((4096 - sizeof(fat_header)) / sizeof(fat_arch)) )
+			throwf("fat header too large: %u entries", OSSwapBigToHostInt32(fileStartAsFat->nfat_arch));
 		if ( fatFindBest(fileStartAsFat, &fileOffset, &fileLength) ) {
-			pread(fd, firstPage, 4096, fileOffset);
+			if ( (fileOffset+fileLength) > (uint64_t)(stat_buf.st_size) )
+				throwf("truncated fat file.  file length=%llu, but needed slice goes to %llu", stat_buf.st_size, fileOffset+fileLength);
+			if (pread(fd, firstPages, 4096, fileOffset) != 4096)
+				throwf("pread of fat file failed: %d", errno);
 		}
 		else {
 			throw "no matching architecture in universal wrapper";
@@ -1190,51 +3094,80 @@
 	}
 	
 	// try mach-o loader
-	if ( isCompatibleMachO(firstPage) ) {
-		char realFilePath[PATH_MAX];
-		if ( gLinkContext.slideAndPackDylibs ) {
-			// when prebinding, we always want to track the real path of images
-			if ( realpath(path, realFilePath) != NULL )
-				path = realFilePath;
-		}
-
-		// instantiate an image
-		ImageLoader* image = new ImageLoaderMachO(path, fd, firstPage, fileOffset, fileLength, stat_buf, gLinkContext);
+	if ( shortPage ) 
+		throw "file too short";
+
+	if ( isCompatibleMachO(firstPages, path) ) {
+
+		// only MH_BUNDLE, MH_DYLIB, and some MH_EXECUTE can be dynamically loaded
+		const mach_header* mh = (mach_header*)firstPages;
+		switch ( mh->filetype ) {
+			case MH_EXECUTE:
+			case MH_DYLIB:
+			case MH_BUNDLE:
+				break;
+			default:
+				throw "mach-o, but wrong filetype";
+		}
+
+		uint32_t headerAndLoadCommandsSize = sizeof(macho_header) + mh->sizeofcmds;
+		if ( headerAndLoadCommandsSize > MAX_MACH_O_HEADER_AND_LOAD_COMMANDS_SIZE )
+			throwf("malformed mach-o: load commands size (%u) > %u", headerAndLoadCommandsSize, MAX_MACH_O_HEADER_AND_LOAD_COMMANDS_SIZE);
+
+		if ( headerAndLoadCommandsSize > fileLength )
+			dyld::throwf("malformed mach-o: load commands size (%u) > mach-o file size (%llu)", headerAndLoadCommandsSize, fileLength);
+
+		if ( headerAndLoadCommandsSize > 4096 ) {
+			// read more pages
+			unsigned readAmount = headerAndLoadCommandsSize - 4096;
+			if ( pread(fd, &firstPages[4096], readAmount, fileOffset+4096) != readAmount )
+				throwf("pread of extra load commands past 4KB failed: %d", errno);
+		}
+
+#if TARGET_IPHONE_SIMULATOR	
+		// <rdar://problem/14168872> dyld_sim should restrict loading osx binaries
+		if ( !isSimulatorBinary(firstPages, path) ) {
+	#if TARGET_OS_WATCH
+			throw "mach-o, but not built for watchOS simulator";
+	#elif TARGET_OS_TV
+			throw "mach-o, but not built for tvOS simulator";
+	#else
+			throw "mach-o, but not built for iOS simulator";
+	#endif
+		}
+#endif
+
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+		if ( gLinkContext.marzipan ) {
+			const dyld3::MachOFile* mf = (dyld3::MachOFile*)firstPages;
+			bool isiOSMacBinary = mf->supportsPlatform(dyld3::Platform::iOSMac) || iOSMacWhiteListed(path);
+			bool isProhibitedMacOSBinary = !isiOSMacBinary && iOSMacBlackListed(path);
+			if ( (context.enforceIOSMac && !isiOSMacBinary) || isProhibitedMacOSBinary ) {
+				throw "mach-o, but not built for iOSMac";
+			}
+		}
+#endif
+
+#if __arm64e__
+		if ( (sMainExecutableMachHeader->cpusubtype == CPU_SUBTYPE_ARM64_E) && (mh->cpusubtype != CPU_SUBTYPE_ARM64_E) )
+			throw "arm64 dylibs cannot be loaded into arm64e processes";
+#endif
+		ImageLoader* image = nullptr;
+		{
+			dyld3::ScopedTimer timer(DBG_DYLD_TIMING_MAP_IMAGE, path, 0, 0);
+			image = ImageLoaderMachO::instantiateFromFile(path, fd, firstPagesPtr, headerAndLoadCommandsSize, fileOffset, fileLength, stat_buf, gLinkContext);
+			timer.setData4((uint64_t)image->machHeader());
+		}
 		
-		// now sanity check that this loaded image does not have the same install path as any existing image
-		const char* loadedImageInstallPath = image->getInstallPath();
-		if ( image->isDylib() && (loadedImageInstallPath != NULL) && (loadedImageInstallPath[0] == '/') ) {
-			for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
-				ImageLoader* anImage = *it;
-				const char* installPath = anImage->getInstallPath();
-				if ( installPath != NULL) {
-					if ( strcmp(loadedImageInstallPath, installPath) == 0 ) {
-						//fprintf(stderr, "duplicate(%s) => %p\n", installPath, anImage);
-						delete image;
-						return anImage;
-					}
-				}
-			}
-		}
-
-		// some API's restrict what they can load
-		if ( context.mustBeBundle && !image->isBundle() )
-			throw "not a bundle";
-		if ( context.mustBeDylib && !image->isDylib() )
-			throw "not a dylib";
-
-		// don't add bundles to global list, they can be loaded but not linked.  When linked it will be added to list
-		if ( ! image->isBundle() ) 
-			addImage(image);
-
-		return image;
+		// validate
+		return checkandAddImage(image, context);
 	}
 	
-	// try other file formats...
+	// try other file formats here...
 	
 	
 	// throw error about what was found
-	switch (*(uint32_t*)firstPage) {
+	switch (*(uint32_t*)firstPages) {
 		case MH_MAGIC:
 		case MH_CIGAM:
 		case MH_MAGIC_64:
@@ -1242,67 +3175,184 @@
 			throw "mach-o, but wrong architecture";
 		default:
 		throwf("unknown file type, first eight bytes: 0x%02X 0x%02X 0x%02X 0x%02X 0x%02X 0x%02X 0x%02X 0x%02X", 
-			firstPage[0], firstPage[1], firstPage[2], firstPage[3], firstPage[4], firstPage[5], firstPage[6],firstPage[7]);
-	}
-}
-
-
-// try to open file
-static ImageLoader* loadPhase5open(const char* path, const LoadContext& context, std::vector<const char*>* exceptions)
-{
-	//fprintf(stdout, "%s(%s)\n", __func__, path);
-	ImageLoader* image = NULL;
+			firstPages[0], firstPages[1], firstPages[2], firstPages[3], firstPages[4], firstPages[5], firstPages[6],firstPages[7]);
+	}
+}
+
+
+static ImageLoader* loadPhase5open(const char* path, const LoadContext& context, const struct stat& stat_buf, std::vector<const char*>* exceptions)
+{
+	//dyld::log("%s(%s, %p)\n", __func__ , path, exceptions);
 
 	// open file (automagically closed when this function exits)
 	FileOpener file(path);
-	
-	//fprintf(stderr, "open(%s) => %d\n", path, file.getFileDescriptor() );
-	
-	if ( file.getFileDescriptor() == -1 )
+		
+	// just return NULL if file not found, but record any other errors
+	if ( file.getFileDescriptor() == -1 ) {
+		int err = errno;
+		if ( err != ENOENT ) {
+			const char* newMsg;
+			if ( (err == EPERM) && sandboxBlockedOpen(path) )
+				newMsg = dyld::mkstringf("file system sandbox blocked open() of '%s'", path);
+			else
+				newMsg = dyld::mkstringf("%s: open() failed with errno=%d", path, err);
+			exceptions->push_back(newMsg);
+		}
 		return NULL;
-		
-	struct stat stat_buf;
-#if __ppc64__
-	memset(&stat_buf, 254, sizeof(struct stat));	 // hack until rdar://problem/3845883 is fixed
-#endif
-	if ( fstat(file.getFileDescriptor(), &stat_buf) == -1)
-		throw "stat error";
-	
-	// in case image was renamed or found via symlinks, check for inode match
-	image = findLoadedImage(stat_buf);
-	if ( image != NULL )
-		return image;
-	
-	// needed to implement NSADDIMAGE_OPTION_RETURN_ONLY_IF_LOADED
-	if ( context.dontLoad )
-		return NULL;
-	
+	}
+
 	try {
 		return loadPhase6(file.getFileDescriptor(), stat_buf, path, context);
 	}
 	catch (const char* msg) {
-		char* newMsg = new char[strlen(msg) + strlen(path) + 8];
-		sprintf(newMsg, "%s: %s", path, msg);
+		const char* newMsg = dyld::mkstringf("%s: %s", path, msg);
 		exceptions->push_back(newMsg);
+		free((void*)msg);
 		return NULL;
 	}
 }
 
+
+
+// try to open file
+static ImageLoader* loadPhase5load(const char* path, const char* orgPath, const LoadContext& context, unsigned& cacheIndex, std::vector<const char*>* exceptions)
+{
+	//dyld::log("%s(%s, %p)\n", __func__ , path, exceptions);
+#if SUPPORT_ACCELERATE_TABLES
+	if ( sAllCacheImagesProxy != NULL ) {
+		if ( sAllCacheImagesProxy->hasDylib(path, &cacheIndex) )
+			return sAllCacheImagesProxy;
+	}
+#endif
+#if TARGET_IPHONE_SIMULATOR
+	// in simulators, 'path' has DYLD_ROOT_PATH prepended, but cache index does not have the prefix, so use orgPath
+	const char* pathToFindInCache = orgPath;
+#else
+	const char* pathToFindInCache = path;
+#endif
+	uint statErrNo;
+	struct stat statBuf;
+	bool didStat = false;
+	bool existsOnDisk;
+	dyld3::SharedCacheFindDylibResults shareCacheResults;
+	shareCacheResults.image = nullptr;
+	if ( dyld3::findInSharedCacheImage(sSharedCacheLoadInfo, pathToFindInCache, &shareCacheResults) ) {
+		// see if this image in the cache was already loaded via a different path
+		for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); ++it) {
+			ImageLoader* anImage = *it;
+			if ( (const mach_header*)anImage->machHeader() == shareCacheResults.mhInCache )
+				return anImage;
+		}
+		// if RTLD_NOLOAD, do nothing if not already loaded
+		if ( context.dontLoad ) {
+			// <rdar://33412890> possible that there is an override of cache
+			if ( my_stat(path, &statBuf) == 0 ) {
+				ImageLoader* imageLoader = findLoadedImage(statBuf);
+				if ( imageLoader != NULL )
+					return imageLoader;
+			}
+			return NULL;
+		}
+		bool useCache = false;
+		if ( shareCacheResults.image == nullptr ) {
+			// HACK to support old caches
+			existsOnDisk = ( my_stat(path, &statBuf) == 0 );
+			didStat = true;
+			statErrNo = errno;
+			useCache = !existsOnDisk;
+		}
+		else {
+			// <rdar://problem/7014995> zero out stat buffer so mtime, etc are zero for items from the shared cache
+			bzero(&statBuf, sizeof(statBuf));
+			if ( shareCacheResults.image->overridableDylib() ) {
+				existsOnDisk = ( my_stat(path, &statBuf) == 0 );
+				didStat = true;
+				statErrNo = errno;
+				if ( sSharedCacheLoadInfo.loadAddress->header.dylibsExpectedOnDisk ) {
+					uint64_t expectedINode;
+					uint64_t expectedMtime;
+					if ( shareCacheResults.image->hasFileModTimeAndInode(expectedINode, expectedMtime) ) {
+						if ( (expectedMtime == statBuf.st_mtime) && (expectedINode == statBuf.st_ino) )
+							useCache = true;
+					}
+				}
+				else {
+					if ( !existsOnDisk )
+						useCache = true;
+				}
+			}
+			else {
+				useCache = true;
+			}
+		}
+		if ( useCache ) {
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+			if ( gLinkContext.marzipan ) {
+				const dyld3::MachOFile* mf = (dyld3::MachOFile*)shareCacheResults.mhInCache;
+				bool isiOSMacBinary = mf->supportsPlatform(dyld3::Platform::iOSMac) || iOSMacWhiteListed(path);
+				bool isProhibitedMacOSBinary = !isiOSMacBinary && iOSMacBlackListed(path);
+				if ( (context.enforceIOSMac && !isiOSMacBinary) || isProhibitedMacOSBinary ) {
+					throw "mach-o, but not built for iOSMac";
+				}
+			}
+#endif
+			ImageLoader* imageLoader = ImageLoaderMachO::instantiateFromCache((macho_header*)shareCacheResults.mhInCache, shareCacheResults.pathInCache, shareCacheResults.slideInCache, statBuf, gLinkContext);
+			return checkandAddImage(imageLoader, context);
+		}
+	}
+
+	// not in cache or cache not usable
+	if ( !didStat ) {
+		existsOnDisk = ( my_stat(path, &statBuf) == 0 );
+		statErrNo = errno;
+	}
+	if ( existsOnDisk ) {
+		// in case image was renamed or found via symlinks, check for inode match
+		ImageLoader* imageLoader = findLoadedImage(statBuf);
+		if ( imageLoader != NULL )
+			return imageLoader;
+		// do nothing if not already loaded and if RTLD_NOLOAD 
+		if ( context.dontLoad )
+			return NULL;
+		// try opening file
+		imageLoader = loadPhase5open(path, context, statBuf, exceptions);
+		if ( imageLoader != NULL ) {
+			if ( shareCacheResults.image != nullptr ) {
+				// if image was found in cache, but is overridden by a newer file on disk, record what the image overrides
+				imageLoader->setOverridesCachedDylib(shareCacheResults.image->imageNum());
+			}
+			return imageLoader;
+		}
+	}
+
+	// just return NULL if file not found, but record any other errors
+	if ( (statErrNo != ENOENT) && (statErrNo != 0) ) {
+		if ( (statErrNo == EPERM) && sandboxBlockedStat(path) )
+			exceptions->push_back(dyld::mkstringf("%s: file system sandbox blocked stat()", path));
+		else
+			exceptions->push_back(dyld::mkstringf("%s: stat() failed with errno=%d", path, statErrNo));
+	}
+	return NULL;
+}
+
 // look for path match with existing loaded images
-static ImageLoader* loadPhase5check(const char* path, const LoadContext& context)
-{
-	//fprintf(stderr, "%s(%s)\n", __func__ , path);
+static ImageLoader* loadPhase5check(const char* path, const char* orgPath, const LoadContext& context)
+{
+	//dyld::log("%s(%s, %s)\n", __func__ , path, orgPath);
 	// search path against load-path and install-path of all already loaded images
 	uint32_t hash = ImageLoader::hash(path);
+	//dyld::log("check() hash=%d, path=%s\n", hash, path);
 	for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
 		ImageLoader* anImage = *it;
-		// check has first to cut down on strcmp calls
-		if ( anImage->getPathHash() == hash )
+		// check hash first to cut down on strcmp calls
+		//dyld::log("    check() hash=%d, path=%s\n", anImage->getPathHash(), anImage->getPath());
+		if ( anImage->getPathHash() == hash ) {
 			if ( strcmp(path, anImage->getPath()) == 0 ) {
 				// if we are looking for a dylib don't return something else
 				if ( !context.mustBeDylib || anImage->isDylib() )
 					return anImage;
 			}
+		}
 		if ( context.matchByInstallName || anImage->matchInstallPath() ) {
 			const char* installPath = anImage->getInstallPath();
 			if ( installPath != NULL) {
@@ -1313,45 +3363,81 @@
 				}
 			}
 		}
+		// an install name starting with @rpath should match by install name, not just real path
+		if ( (orgPath[0] == '@') && (strncmp(orgPath, "@rpath/", 7) == 0) ) {
+			const char* installPath = anImage->getInstallPath();
+			if ( installPath != NULL) {
+				if ( !context.mustBeDylib || anImage->isDylib() ) {
+					if ( strcmp(orgPath, installPath) == 0 )
+						return anImage;
+				}
+			}
+		}
 	}
 	
-	//fprintf(stderr, "check(%s) => NULL\n", path);
+	//dyld::log("%s(%s) => NULL\n", __func__,   path);
 	return NULL;
 }
 
 
 // open or check existing
-static ImageLoader* loadPhase5(const char* path, const LoadContext& context, std::vector<const char*>* exceptions)
-{
-	//fprintf(stderr, "%s(%s)\n", __func__ , path);
+static ImageLoader* loadPhase5(const char* path, const char* orgPath, const LoadContext& context, unsigned& cacheIndex, std::vector<const char*>* exceptions)
+{
+	//dyld::log("%s(%s, %p)\n", __func__ , path, exceptions);
+	
+	// check for specific dylib overrides
+	for (std::vector<DylibOverride>::iterator it = sDylibOverrides.begin(); it != sDylibOverrides.end(); ++it) {
+		if ( strcmp(it->installName, path) == 0 ) {
+			path = it->override;
+			break;
+		}
+	}
+	
 	if ( exceptions != NULL ) 
-		return loadPhase5open(path, context, exceptions);
+		return loadPhase5load(path, orgPath, context, cacheIndex, exceptions);
 	else
-		return loadPhase5check(path, context);
+		return loadPhase5check(path, orgPath, context);
 }
 
 // try with and without image suffix
-static ImageLoader* loadPhase4(const char* path, const LoadContext& context, std::vector<const char*>* exceptions)
-{
-	//fprintf(stderr, "%s(%s)\n", __func__ , path);
+static ImageLoader* loadPhase4(const char* path, const char* orgPath, const LoadContext& context, unsigned& cacheIndex, std::vector<const char*>* exceptions)
+{
+	//dyld::log("%s(%s, %p)\n", __func__ , path, exceptions);
 	ImageLoader* image = NULL;
-	if (  gLinkContext.imageSuffix != NULL ) {
-		char pathWithSuffix[strlen(path)+strlen( gLinkContext.imageSuffix)+2];
-		ImageLoader::addSuffix(path,  gLinkContext.imageSuffix, pathWithSuffix);
-		image = loadPhase5(pathWithSuffix, context, exceptions);
+	if ( gLinkContext.imageSuffix != NULL ) {
+ 		for (const char* const* suffix=gLinkContext.imageSuffix; *suffix != NULL; ++suffix) {
+ 			char pathWithSuffix[strlen(path)+strlen(*suffix)+2];
+ 			ImageLoader::addSuffix(path, *suffix, pathWithSuffix);
+ 			image = loadPhase5(pathWithSuffix, orgPath, context, cacheIndex, exceptions);
+ 			if ( image != NULL )
+ 				break;
+ 		}
+		if ( image != NULL ) {
+			// if original path is in the dyld cache, then mark this one found as an override
+			dyld3::SharedCacheFindDylibResults shareCacheResults;
+			if ( dyld3::findInSharedCacheImage(sSharedCacheLoadInfo, path, &shareCacheResults) && (shareCacheResults.image != nullptr) )
+				image->setOverridesCachedDylib(shareCacheResults.image->imageNum());
+		}
 	}
 	if ( image == NULL )
-		image = loadPhase5(path, context, exceptions);
+		image = loadPhase5(path, orgPath, context, cacheIndex, exceptions);
 	return image;
 }
 
+static ImageLoader* loadPhase2(const char* path, const char* orgPath, const LoadContext& context,
+							   const char* const frameworkPaths[], const char* const libraryPaths[],
+							   unsigned& cacheIndex, std::vector<const char*>* exceptions); // forward reference
+
 
 // expand @ variables
-static ImageLoader* loadPhase3(const char* path, const LoadContext& context, std::vector<const char*>* exceptions)
-{
-	//fprintf(stderr, "%s(%s)\n", __func__ , path);
+static ImageLoader* loadPhase3(const char* path, const char* orgPath, const LoadContext& context, unsigned& cacheIndex, std::vector<const char*>* exceptions)
+{
+	//dyld::log("%s(%s, %p)\n", __func__ , path, exceptions);
 	ImageLoader* image = NULL;
 	if ( strncmp(path, "@executable_path/", 17) == 0 ) {
+		// executable_path cannot be in used in any binary in a setuid process rdar://problem/4589305
+		if ( !gLinkContext.allowAtPaths )
+			throwf("unsafe use of @executable_path in %s with restricted binary", context.origin);
 		// handle @executable_path path prefix
 		const char* executablePath = sExecPath;
 		char newPath[strlen(executablePath) + strlen(path)];
@@ -1361,7 +3447,7 @@
 			strcpy(&addPoint[1], &path[17]);
 		else
 			strcpy(newPath, &path[17]);
-		image = loadPhase4(newPath, context, exceptions);
+		image = loadPhase4(newPath, orgPath, context, cacheIndex, exceptions);
 		if ( image != NULL ) 
 			return image;
 
@@ -1370,17 +3456,20 @@
 		if ( realpath(sExecPath, resolvedPath) != NULL ) {
 			char newRealPath[strlen(resolvedPath) + strlen(path)];
 			strcpy(newRealPath, resolvedPath);
-			char* addPoint = strrchr(newRealPath,'/');
+			addPoint = strrchr(newRealPath,'/');
 			if ( addPoint != NULL )
 				strcpy(&addPoint[1], &path[17]);
 			else
 				strcpy(newRealPath, &path[17]);
-			image = loadPhase4(newRealPath, context, exceptions);
+			image = loadPhase4(newRealPath, orgPath, context, cacheIndex, exceptions);
 			if ( image != NULL ) 
 				return image;
 		}
 	}
 	else if ( (strncmp(path, "@loader_path/", 13) == 0) && (context.origin != NULL) ) {
+		// @loader_path cannot be used from the main executable of a setuid process rdar://problem/4589305
+		if ( !gLinkContext.allowAtPaths  && (strcmp(context.origin, sExecPath) == 0) )
+			throwf("unsafe use of @loader_path in %s with restricted binary", context.origin);
 		// handle @loader_path path prefix
 		char newPath[strlen(context.origin) + strlen(path)];
 		strcpy(newPath, context.origin);
@@ -1389,7 +3478,7 @@
 			strcpy(&addPoint[1], &path[13]);
 		else
 			strcpy(newPath, &path[13]);
-		image = loadPhase4(newPath, context, exceptions);
+		image = loadPhase4(newPath, orgPath, context, cacheIndex, exceptions);
 		if ( image != NULL ) 
 			return image;
 		
@@ -1398,89 +3487,166 @@
 		if ( realpath(context.origin, resolvedPath) != NULL ) {
 			char newRealPath[strlen(resolvedPath) + strlen(path)];
 			strcpy(newRealPath, resolvedPath);
-			char* addPoint = strrchr(newRealPath,'/');
+			addPoint = strrchr(newRealPath,'/');
 			if ( addPoint != NULL )
 				strcpy(&addPoint[1], &path[13]);
 			else
 				strcpy(newRealPath, &path[13]);
-			image = loadPhase4(newRealPath, context, exceptions);
+			image = loadPhase4(newRealPath, orgPath, context, cacheIndex, exceptions);
 			if ( image != NULL ) 
 				return image;
 		}
 	}
-	
-	return loadPhase4(path, context, exceptions);
+	else if ( context.implicitRPath || (strncmp(path, "@rpath/", 7) == 0) ) {
+		const char* trailingPath = (strncmp(path, "@rpath/", 7) == 0) ? &path[7] : path;
+		// substitute @rpath with all -rpath paths up the load chain
+		for(const ImageLoader::RPathChain* rp=context.rpath; rp != NULL; rp=rp->next) {
+			if (rp->paths != NULL ) {
+				for(std::vector<const char*>::iterator it=rp->paths->begin(); it != rp->paths->end(); ++it) {
+					const char* anRPath = *it;
+					char newPath[strlen(anRPath) + strlen(trailingPath)+2];
+					strcpy(newPath, anRPath);
+					if ( newPath[strlen(newPath)-1] != '/' )
+						strcat(newPath, "/");
+					strcat(newPath, trailingPath); 
+					image = loadPhase4(newPath, orgPath, context, cacheIndex, exceptions);
+					if ( gLinkContext.verboseRPaths && (exceptions != NULL) ) {
+						if ( image != NULL ) 
+							dyld::log("RPATH successful expansion of %s to: %s\n", orgPath, newPath);
+						else
+							dyld::log("RPATH failed to expanding     %s to: %s\n", orgPath, newPath);
+					}
+					if ( image != NULL ) 
+						return image;
+				}
+			}
+		}
+		
+		// substitute @rpath with LD_LIBRARY_PATH
+		if ( sEnv.LD_LIBRARY_PATH != NULL ) {
+			image = loadPhase2(trailingPath, orgPath, context, NULL, sEnv.LD_LIBRARY_PATH, cacheIndex, exceptions);
+			if ( image != NULL )
+				return image;
+		}
+		
+		// if this is the "open" pass, don't try to open @rpath/... as a relative path
+		if ( (exceptions != NULL) && (trailingPath != path) )
+			return NULL;
+	}
+	else if ( !gLinkContext.allowEnvVarsPath && (path[0] != '/' ) ) {
+		throwf("unsafe use of relative rpath %s in %s with restricted binary", path, context.origin);
+	}
+
+	return loadPhase4(path, orgPath, context, cacheIndex, exceptions);
+}
+
+static ImageLoader* loadPhase2cache(const char* path, const char *orgPath, const LoadContext& context, unsigned& cacheIndex, std::vector<const char*>* exceptions) {
+	ImageLoader* image = NULL;
+#if !TARGET_IPHONE_SIMULATOR
+	if ( exceptions != NULL) {
+		char resolvedPath[PATH_MAX];
+		realpath(path, resolvedPath);
+		int myerr = errno;
+		// If realpath() resolves to a path which does not exist on disk, errno is set to ENOENT
+		if ( (myerr == ENOENT) || (myerr == 0) )
+		{
+			image = loadPhase4(resolvedPath, orgPath, context, cacheIndex, exceptions);
+		}
+	}
+#endif
+	return image;
 }
 
 
 // try search paths
-static ImageLoader* loadPhase2(const char* path, const LoadContext& context, 
+static ImageLoader* loadPhase2(const char* path, const char* orgPath, const LoadContext& context,
 							   const char* const frameworkPaths[], const char* const libraryPaths[], 
-							   std::vector<const char*>* exceptions)
-{
-	//fprintf(stderr, "%s(%s)\n", __func__ , path);
+							   unsigned& cacheIndex, std::vector<const char*>* exceptions)
+{
+	//dyld::log("%s(%s, %p)\n", __func__ , path, exceptions);
 	ImageLoader* image = NULL;
 	const char* frameworkPartialPath = getFrameworkPartialPath(path);
 	if ( frameworkPaths != NULL ) {
 		if ( frameworkPartialPath != NULL ) {
-			const int frameworkPartialPathLen = strlen(frameworkPartialPath);
+			const size_t frameworkPartialPathLen = strlen(frameworkPartialPath);
 			for(const char* const* fp = frameworkPaths; *fp != NULL; ++fp) {
 				char npath[strlen(*fp)+frameworkPartialPathLen+8];
 				strcpy(npath, *fp);
 				strcat(npath, "/");
 				strcat(npath, frameworkPartialPath);
-				//fprintf(stderr, "dyld: fallback framework path used: %s() -> loadPhase4(\"%s\", ...)\n", __func__, npath);
-				image = loadPhase4(npath, context, exceptions);
-				if ( image != NULL )
+				//dyld::log("dyld: fallback framework path used: %s() -> loadPhase4(\"%s\", ...)\n", __func__, npath);
+				image = loadPhase4(npath, orgPath, context, cacheIndex, exceptions);
+				// Look in the cache if appropriate
+				if ( image == NULL)
+					image = loadPhase2cache(npath, orgPath, context, cacheIndex, exceptions);
+				if ( image != NULL ) {
+					// if original path is in the dyld cache, then mark this one found as an override
+					dyld3::SharedCacheFindDylibResults shareCacheResults;
+					if ( dyld3::findInSharedCacheImage(sSharedCacheLoadInfo, path, &shareCacheResults) && (shareCacheResults.image != nullptr) )
+						image->setOverridesCachedDylib(shareCacheResults.image->imageNum());
 					return image;
-			}
-		}
-	}
-	if ( libraryPaths != NULL ) {
+				}
+			}
+		}
+	}
+	// <rdar://problem/12649639> An executable with the same name as a framework & DYLD_LIBRARY_PATH pointing to it gets loaded twice
+	// <rdar://problem/14160846> Some apps depend on frameworks being found via library paths
+	if ( (libraryPaths != NULL) && ((frameworkPartialPath == NULL) || sFrameworksFoundAsDylibs) ) {
 		const char* libraryLeafName = getLibraryLeafName(path);
-		const int libraryLeafNameLen = strlen(libraryLeafName);
+		const size_t libraryLeafNameLen = strlen(libraryLeafName);
 		for(const char* const* lp = libraryPaths; *lp != NULL; ++lp) {
 			char libpath[strlen(*lp)+libraryLeafNameLen+8];
 			strcpy(libpath, *lp);
 			strcat(libpath, "/");
 			strcat(libpath, libraryLeafName);
-			//fprintf(stderr, "dyld: fallback library path used: %s() -> loadPhase4(\"%s\", ...)\n", __func__, libpath);
-			image = loadPhase4(libpath, context, exceptions);
-			if ( image != NULL )
+			//dyld::log("dyld: fallback library path used: %s() -> loadPhase4(\"%s\", ...)\n", __func__, libpath);
+			image = loadPhase4(libpath, orgPath, context, cacheIndex, exceptions);
+			// Look in the cache if appropriate
+			if ( image == NULL)
+				image = loadPhase2cache(libpath, orgPath, context, cacheIndex, exceptions);
+			if ( image != NULL ) {
+				// if original path is in the dyld cache, then mark this one found as an override
+				dyld3::SharedCacheFindDylibResults shareCacheResults;
+				if ( dyld3::findInSharedCacheImage(sSharedCacheLoadInfo, path, &shareCacheResults) && (shareCacheResults.image != nullptr) )
+					image->setOverridesCachedDylib(shareCacheResults.image->imageNum());
 				return image;
+			}
 		}
 	}
 	return NULL;
 }
 
 // try search overrides and fallbacks
-static ImageLoader* loadPhase1(const char* path, const LoadContext& context, std::vector<const char*>* exceptions)
-{
-	//fprintf(stderr, "%s(%s)\n", __func__ , path);
+static ImageLoader* loadPhase1(const char* path, const char* orgPath, const LoadContext& context, unsigned& cacheIndex, std::vector<const char*>* exceptions)
+{
+	//dyld::log("%s(%s, %p)\n", __func__ , path, exceptions);
 	ImageLoader* image = NULL;
 
 	// handle LD_LIBRARY_PATH environment variables that force searching
 	if ( context.useLdLibraryPath && (sEnv.LD_LIBRARY_PATH != NULL) ) {
-		image = loadPhase2(path, context, NULL, sEnv.LD_LIBRARY_PATH, exceptions);
+		image = loadPhase2(path, orgPath, context,  NULL, sEnv.LD_LIBRARY_PATH, cacheIndex,exceptions);
 		if ( image != NULL )
 			return image;
 	}
 
 	// handle DYLD_ environment variables that force searching
 	if ( context.useSearchPaths && ((sEnv.DYLD_FRAMEWORK_PATH != NULL) || (sEnv.DYLD_LIBRARY_PATH != NULL)) ) {
-		image = loadPhase2(path, context, sEnv.DYLD_FRAMEWORK_PATH, sEnv.DYLD_LIBRARY_PATH, exceptions);
+		image = loadPhase2(path, orgPath, context, sEnv.DYLD_FRAMEWORK_PATH, sEnv.DYLD_LIBRARY_PATH, cacheIndex, exceptions);
 		if ( image != NULL )
 			return image;
 	}
 	
 	// try raw path
-	image = loadPhase3(path, context, exceptions);
+	image = loadPhase3(path, orgPath, context, cacheIndex, exceptions);
 	if ( image != NULL )
 		return image;
 	
 	// try fallback paths during second time (will open file)
-	if ( (exceptions != NULL) && ((sEnv.DYLD_FALLBACK_FRAMEWORK_PATH != NULL) || (sEnv.DYLD_FALLBACK_LIBRARY_PATH != NULL)) ) {
-		image = loadPhase2(path, context, sEnv.DYLD_FALLBACK_FRAMEWORK_PATH, sEnv.DYLD_FALLBACK_LIBRARY_PATH, exceptions);
+	const char* const* fallbackLibraryPaths = sEnv.DYLD_FALLBACK_LIBRARY_PATH;
+	if ( (fallbackLibraryPaths != NULL) && !context.useFallbackPaths )
+		fallbackLibraryPaths = NULL;
+	if ( !context.dontLoad  && (exceptions != NULL) && ((sEnv.DYLD_FALLBACK_FRAMEWORK_PATH != NULL) || (fallbackLibraryPaths != NULL)) ) {
+		image = loadPhase2(path, orgPath, context, sEnv.DYLD_FALLBACK_FRAMEWORK_PATH, fallbackLibraryPaths, cacheIndex, exceptions);
 		if ( image != NULL )
 			return image;
 	}
@@ -1489,24 +3655,59 @@
 }
 
 // try root substitutions
-static ImageLoader* loadPhase0(const char* path, const LoadContext& context, std::vector<const char*>* exceptions)
-{
-	//fprintf(stderr, "%s(%s)\n", __func__ , path);
+static ImageLoader* loadPhase0(const char* path, const char* orgPath, const LoadContext& context, unsigned& cacheIndex, std::vector<const char*>* exceptions)
+{
+	//dyld::log("%s(%s, %p)\n", __func__ , path, exceptions);
+
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+	// handle macOS dylibs dlopen()ing versioned path which needs to map to flat path in mazipan simulator
+	if ( gLinkContext.marzipan && strstr(path, ".framework/Versions/")) {
+		uintptr_t sourceOffset = 0;
+		uintptr_t destOffset = 0;
+		size_t sourceLangth = strlen(path);
+		char flatPath[sourceLangth];
+		flatPath[0] = 0;
+		const char* frameworkBase = NULL;
+		while ((frameworkBase = strstr(&path[sourceOffset], ".framework/Versions/"))) {
+			uintptr_t foundLength = (frameworkBase - &path[sourceOffset]) + strlen(".framework/") ;
+			strlcat(&flatPath[destOffset], &path[sourceOffset], foundLength);
+			sourceOffset += foundLength + strlen("Versions/") + 1;
+			destOffset += foundLength - 1;
+		}
+		strlcat(&flatPath[destOffset], &path[sourceOffset], sourceLangth);
+		ImageLoader* image = loadPhase0(flatPath, orgPath, context, cacheIndex, exceptions);
+		if ( image != NULL )
+			return image;
+	}
+#endif
 	
+#if SUPPORT_ROOT_PATH
 	// handle DYLD_ROOT_PATH which forces absolute paths to use a new root
-	if ( (sEnv.DYLD_ROOT_PATH != NULL) && (path[0] == '/') ) {
-		for(const char* const* rootPath = sEnv.DYLD_ROOT_PATH ; *rootPath != NULL; ++rootPath) {
-			char newPath[strlen(*rootPath) + strlen(path)+2];
-			strcpy(newPath, *rootPath);
-			strcat(newPath, path);
-			ImageLoader* image = loadPhase1(newPath, context, exceptions);
-			if ( image != NULL )
-				return image;
-		}
-	}
+	if ( (gLinkContext.rootPaths != NULL) && (path[0] == '/') ) {
+		for(const char* const* rootPath = gLinkContext.rootPaths; *rootPath != NULL; ++rootPath) {
+			size_t rootLen = strlen(*rootPath);
+			if ( strncmp(path, *rootPath, rootLen) != 0 ) {
+				char newPath[rootLen + strlen(path)+2];
+				strcpy(newPath, *rootPath);
+				strcat(newPath, path);
+				ImageLoader* image = loadPhase1(newPath, orgPath, context, cacheIndex, exceptions);
+				if ( image != NULL )
+					return image;
+			}
+		}
+	}
+#endif
 
 	// try raw path
-	return loadPhase1(path, context, exceptions);
+	return loadPhase1(path, orgPath, context, cacheIndex, exceptions);
+}
+
+static bool cacheablePath(const char* path) {
+	if (strncmp(path, "/usr/lib/", 9) == 0)
+		return true;
+	if (strncmp(path, "/System/Library/", 16) == 0)
+		return true;
+	return false;
 }
 
 //
@@ -1523,82 +3724,140 @@
 // the path.  Either time, if an image is found, the phases all unwind without checking
 // for other paths.
 //
-ImageLoader* load(const char* path, const LoadContext& context)
-{
-	//fprintf(stderr, "%s(%s)\n", __func__ , path);
+ImageLoader* load(const char* path, const LoadContext& context, unsigned& cacheIndex)
+{
+	CRSetCrashLogMessage2(path);
+	const char* orgPath = path;
+	cacheIndex = UINT32_MAX;
+	
+	//dyld::log("%s(%s)\n", __func__ , path);
 	char realPath[PATH_MAX];
 	// when DYLD_IMAGE_SUFFIX is in used, do a realpath(), otherwise a load of "Foo.framework/Foo" will not match
-	if ( context.useSearchPaths && ( gLinkContext.imageSuffix != NULL) ) {
+	if ( context.useSearchPaths && ( gLinkContext.imageSuffix != NULL && *gLinkContext.imageSuffix != NULL) ) {
 		if ( realpath(path, realPath) != NULL )
 			path = realPath;
 	}
 	
 	// try all path permutations and check against existing loaded images
-	ImageLoader* image = loadPhase0(path, context, NULL);
-	if ( image != NULL )
+
+	ImageLoader* image = loadPhase0(path, orgPath, context, cacheIndex, NULL);
+	if ( image != NULL ) {
+		CRSetCrashLogMessage2(NULL);
 		return image;
-	
-	// try all path permutations and try open() until first sucesss
+	}
+
+	// try all path permutations and try open() until first success
 	std::vector<const char*> exceptions;
-	image = loadPhase0(path, context, &exceptions);
-	if ( image != NULL )
+	image = loadPhase0(path, orgPath, context, cacheIndex, &exceptions);
+#if !TARGET_IPHONE_SIMULATOR
+	// <rdar://problem/16704628> support symlinks on disk to a path in dyld shared cache
+	if ( image == NULL)
+		image = loadPhase2cache(path, orgPath, context, cacheIndex, &exceptions);
+#endif
+    CRSetCrashLogMessage2(NULL);
+	if ( image != NULL ) {
+		// <rdar://problem/6916014> leak in dyld during dlopen when using DYLD_ variables
+		for (std::vector<const char*>::iterator it = exceptions.begin(); it != exceptions.end(); ++it) {
+			free((void*)(*it));
+		}
+		// if loaded image is not from cache, but original path is in cache
+		// set gSharedCacheOverridden flag to disable some ObjC optimizations
+		if ( !gSharedCacheOverridden && !image->inSharedCache() && image->isDylib() && cacheablePath(path) && inSharedCache(path) ) {
+			gSharedCacheOverridden = true;
+		}
 		return image;
-	else if ( context.dontLoad )
-		return NULL;
-	else if ( exceptions.size() == 0 )
-		throw "image not found";
+	}
+	else if ( exceptions.size() == 0 ) {
+		if ( context.dontLoad ) {
+			return NULL;
+		}
+		else
+			throw "image not found";
+	}
 	else {
 		const char* msgStart = "no suitable image found.  Did find:";
 		const char* delim = "\n\t";
 		size_t allsizes = strlen(msgStart)+8;
-		for (unsigned int i=0; i < exceptions.size(); ++i) 
+		for (size_t i=0; i < exceptions.size(); ++i) 
 			allsizes += (strlen(exceptions[i]) + strlen(delim));
 		char* fullMsg = new char[allsizes];
 		strcpy(fullMsg, msgStart);
-		for (unsigned int i=0; i < exceptions.size(); ++i) {
+		for (size_t i=0; i < exceptions.size(); ++i) {
 			strcat(fullMsg, delim);
 			strcat(fullMsg, exceptions[i]);
+			free((void*)exceptions[i]);
 		}
 		throw (const char*)fullMsg;
 	}
 }
 
+
+
+
+
+static void mapSharedCache()
+{
+	dyld3::SharedCacheOptions opts;
+	opts.cacheDirOverride	= sSharedCacheOverrideDir;
+	opts.forcePrivate		= (gLinkContext.sharedRegionMode == ImageLoader::kUsePrivateSharedRegion);
+
+
+#if __x86_64__ && !TARGET_IPHONE_SIMULATOR
+	opts.useHaswell			= sHaswell;
+#else
+	opts.useHaswell			= false;
+#endif
+	opts.verbose			= gLinkContext.verboseMapping;
+	loadDyldCache(opts, &sSharedCacheLoadInfo);
+
+	// update global state
+	if ( sSharedCacheLoadInfo.loadAddress != nullptr ) {
+		gLinkContext.dyldCache 								= sSharedCacheLoadInfo.loadAddress;
+		dyld::gProcessInfo->processDetachedFromSharedRegion = opts.forcePrivate;
+		dyld::gProcessInfo->sharedCacheSlide                = sSharedCacheLoadInfo.slide;
+		dyld::gProcessInfo->sharedCacheBaseAddress          = (unsigned long)sSharedCacheLoadInfo.loadAddress;
+		sSharedCacheLoadInfo.loadAddress->getUUID(dyld::gProcessInfo->sharedCacheUUID);
+		dyld3::kdebug_trace_dyld_image(DBG_DYLD_UUID_SHARED_CACHE_A, (const uuid_t *)&dyld::gProcessInfo->sharedCacheUUID[0], {0,0}, {{ 0, 0 }}, (const mach_header *)sSharedCacheLoadInfo.loadAddress);
+	}
+
+//#if __IPHONE_OS_VERSION_MIN_REQUIRED && !TARGET_IPHONE_SIMULATOR
+// RAM disk booting does not have shared cache yet
+// Don't make lack of a shared cache fatal in that case
+//	if ( sSharedCacheLoadInfo.loadAddress == nullptr ) {
+//		if ( sSharedCacheLoadInfo.errorMessage != nullptr )
+//			halt(sSharedCacheLoadInfo.errorMessage);
+//		else
+//			halt("error loading dyld shared cache");
+//	}
+//#endif
+}
 
 
 
 // create when NSLinkModule is called for a second time on a bundle
 ImageLoader* cloneImage(ImageLoader* image)
 {
-	const uint64_t offsetInFat = image->getOffsetInFatFile();
-
 	// open file (automagically closed when this function exits)
 	FileOpener file(image->getPath());
 	
 	struct stat stat_buf;
-#if __ppc64__
-	memset(&stat_buf, 254, sizeof(struct stat));	 // hack until rdar://problem/3845883 is fixed
-#endif
 	if ( fstat(file.getFileDescriptor(), &stat_buf) == -1)
 		throw "stat error";
 	
-	// read first page of file
-	uint8_t firstPage[4096];
-	pread(file.getFileDescriptor(), firstPage, 4096, offsetInFat);
-	
-	// fat length is only used for sanity checking, since this image was already loaded once, just use upper bound
-	uint64_t lenInFat = stat_buf.st_size - offsetInFat;
-	
-	// try mach-o loader
-	if ( isCompatibleMachO(firstPage) ) {
-		ImageLoader* clone = new ImageLoaderMachO(image->getPath(), file.getFileDescriptor(), firstPage, offsetInFat, lenInFat, stat_buf, gLinkContext);
-		// don't add bundles to global list, they can be loaded but not linked.  When linked it will be added to list
-		if ( ! image->isBundle() ) 
-			addImage(clone);
-		return clone;
-	}
-	
-	// try other file formats...
-	throw "can't clone image";
+	dyld::LoadContext context;
+	context.useSearchPaths		= false;
+	context.useFallbackPaths	= false;
+	context.useLdLibraryPath	= false;
+	context.implicitRPath		= false;
+	context.matchByInstallName	= false;
+	context.dontLoad			= false;
+	context.mustBeBundle		= true;
+	context.mustBeDylib			= false;
+	context.canBePIE			= false;
+	context.enforceIOSMac		= false;
+	context.origin				= NULL;
+	context.rpath				= NULL;
+	return loadPhase6(file.getFileDescriptor(), stat_buf, image->getPath(), context);
 }
 
 
@@ -1618,16 +3877,16 @@
 		}
 	}
 
-	// try mach-o each loader
-	if ( isCompatibleMachO(mem) ) {
-		ImageLoader* image = new ImageLoaderMachO(moduleName, (mach_header*)mem, len, gLinkContext);
+	// try each loader
+	if ( isCompatibleMachO(mem, moduleName) ) {
+		ImageLoader* image = ImageLoaderMachO::instantiateFromMemory(moduleName, (macho_header*)mem, len, gLinkContext);
 		// don't add bundles to global list, they can be loaded but not linked.  When linked it will be added to list
 		if ( ! image->isBundle() ) 
 			addImage(image);
 		return image;
 	}
 	
-	// try other file formats...
+	// try other file formats here...
 	
 	// throw error about what was found
 	switch (*(uint32_t*)mem) {
@@ -1648,21 +3907,55 @@
 	// now add to list to get notified when any more images are added
 	sAddImageCallbacks.push_back(func);
 	
-	// call callback with all existing images, starting at roots
-	const int rootCount = sImageRoots.size();
-	for(int i=0; i < rootCount; ++i) {
-		ImageLoader* image = sImageRoots[i];
-		image->runNotification(gLinkContext, sAddImageCallbacks.size());
-	}
-	
-//	for (std::vector<ImageLoader*>::iterator it=sImageRoots.begin(); it != sImageRoots.end(); it++) {
-//		ImageLoader* image = *it;
-//		image->runNotification(gLinkContext, sAddImageCallbacks.size());
-//	}
+	// call callback with all existing images
+	for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+		ImageLoader* image = *it;
+		if ( image->getState() >= dyld_image_state_bound && image->getState() < dyld_image_state_terminated ) {
+			dyld3::ScopedTimer timer(DBG_DYLD_TIMING_FUNC_FOR_ADD_IMAGE, (uint64_t)image->machHeader(), (uint64_t)(*func), 0);
+			(*func)(image->machHeader(), image->getSlide());
+		}
+	}
+#if SUPPORT_ACCELERATE_TABLES
+	if ( sAllCacheImagesProxy != NULL ) {
+		dyld_image_info	infos[allImagesCount()+1];
+		unsigned cacheCount = sAllCacheImagesProxy->appendImagesToNotify(dyld_image_state_bound, true, infos);
+		for (unsigned i=0; i < cacheCount; ++i) {
+			dyld3::ScopedTimer timer(DBG_DYLD_TIMING_FUNC_FOR_ADD_IMAGE, (uint64_t)infos[i].imageLoadAddress, (uint64_t)(*func), 0);
+			(*func)(infos[i].imageLoadAddress, sSharedCacheLoadInfo.slide);
+		}
+	}
+#endif
+}
+
+void registerLoadCallback(LoadImageCallback func)
+{
+	// now add to list to get notified when any more images are added
+	sAddLoadImageCallbacks.push_back(func);
+
+	// call callback with all existing images
+	for (ImageLoader* image : sAllImages) {
+		if ( image->getState() >= dyld_image_state_bound && image->getState() < dyld_image_state_terminated ) {
+			dyld3::ScopedTimer timer(DBG_DYLD_TIMING_FUNC_FOR_ADD_IMAGE, (uint64_t)image->machHeader(), (uint64_t)(*func), 0);
+			(*func)(image->machHeader(), image->getPath(), !image->neverUnload());
+		}
+	}
+#if SUPPORT_ACCELERATE_TABLES
+	if ( sAllCacheImagesProxy != NULL ) {
+		dyld_image_info	infos[allImagesCount()+1];
+		unsigned cacheCount = sAllCacheImagesProxy->appendImagesToNotify(dyld_image_state_bound, true, infos);
+		for (unsigned i=0; i < cacheCount; ++i) {
+			dyld3::ScopedTimer timer(DBG_DYLD_TIMING_FUNC_FOR_ADD_IMAGE, (uint64_t)infos[i].imageLoadAddress, (uint64_t)(*func), 0);
+			(*func)(infos[i].imageLoadAddress, infos[i].imageFilePath, false);
+		}
+	}
+#endif
 }
 
 void registerRemoveCallback(ImageCallback func)
 {
+	// <rdar://problem/15025198> ignore calls to register a notification during a notification
+	if ( sRemoveImageCallbacksInUse )
+		return;
 	sRemoveImageCallbacks.push_back(func);
 }
 
@@ -1674,8 +3967,7 @@
 void setErrorMessage(const char* message)
 {
 	// save off error message in global buffer for CrashReporter to find
-	strncpy(error_string, message, sizeof(error_string)-1);
-	error_string[sizeof(error_string)-1] = '\0';
+	strlcpy(error_string, message, sizeof(error_string));
 }
 
 const char* getErrorMessage()
@@ -1683,21 +3975,49 @@
 	return error_string;
 }
 
-void  halt(const char* message)
-{
-	fprintf(stderr, "dyld: %s\n", message);
+void halt(const char* message)
+{
+	dyld::log("dyld: %s\n", message);
 	setErrorMessage(message);
-	strncpy(error_string, message, sizeof(error_string)-1);
-	error_string[sizeof(error_string)-1] = '\0';
-	
-#if __ppc__ || __ppc64__
-	__asm__  ("trap");
-#elif __i386__
-	__asm__  ("int3");
-#else
-	#error unknown architecture
-#endif
-	abort();	// needed to suppress warning that noreturn function returns
+	dyld::gProcessInfo->errorMessage = error_string;
+	if ( !gLinkContext.startedInitializingMainExecutable )
+		dyld::gProcessInfo->terminationFlags = 1;
+	else
+		dyld::gProcessInfo->terminationFlags = 0;
+
+	char payloadBuffer[EXIT_REASON_PAYLOAD_MAX_LEN];
+	dyld_abort_payload* payload = (dyld_abort_payload*)payloadBuffer;
+	payload->version               = 1;
+	payload->flags                 = gLinkContext.startedInitializingMainExecutable ? 0 : 1;
+	payload->targetDylibPathOffset = 0;
+	payload->clientPathOffset      = 0;
+	payload->symbolOffset          = 0;
+	int payloadSize = sizeof(dyld_abort_payload);
+
+	if ( dyld::gProcessInfo->errorTargetDylibPath != NULL ) {
+		payload->targetDylibPathOffset = payloadSize;
+		payloadSize += strlcpy(&payloadBuffer[payloadSize], dyld::gProcessInfo->errorTargetDylibPath, sizeof(payloadBuffer)-payloadSize) + 1;
+	}
+	if ( dyld::gProcessInfo->errorClientOfDylibPath != NULL ) {
+		payload->clientPathOffset = payloadSize;
+		payloadSize += strlcpy(&payloadBuffer[payloadSize], dyld::gProcessInfo->errorClientOfDylibPath, sizeof(payloadBuffer)-payloadSize) + 1;
+	}
+	if ( dyld::gProcessInfo->errorSymbol != NULL ) {
+		payload->symbolOffset = payloadSize;
+		payloadSize += strlcpy(&payloadBuffer[payloadSize], dyld::gProcessInfo->errorSymbol, sizeof(payloadBuffer)-payloadSize) + 1;
+	}
+	char truncMessage[EXIT_REASON_USER_DESC_MAX_LEN];
+	strlcpy(truncMessage, message, EXIT_REASON_USER_DESC_MAX_LEN);
+	abort_with_payload(OS_REASON_DYLD, dyld::gProcessInfo->errorKind ? dyld::gProcessInfo->errorKind : DYLD_EXIT_REASON_OTHER, payloadBuffer, payloadSize, truncMessage, 0);
+}
+
+static void setErrorStrings(unsigned errorCode, const char* errorClientOfDylibPath,
+								const char* errorTargetDylibPath, const char* errorSymbol)
+{
+	dyld::gProcessInfo->errorKind = errorCode;
+	dyld::gProcessInfo->errorClientOfDylibPath = errorClientOfDylibPath;
+	dyld::gProcessInfo->errorTargetDylibPath = errorTargetDylibPath;
+	dyld::gProcessInfo->errorSymbol = errorSymbol;
 }
 
 
@@ -1706,8 +4026,8 @@
 	uintptr_t result = 0;
 	// acquire read-lock on dyld's data structures
 #if 0 // rdar://problem/3811777 turn off locking until deadlock is resolved
-	if ( gThreadHelpers != NULL ) 
-		(*gThreadHelpers->lockForReading)();
+	if ( gLibSystemHelpers != NULL ) 
+		(*gLibSystemHelpers->lockForReading)();
 #endif
 	// lookup and bind lazy pointer and get target address
 	try {
@@ -1715,7 +4035,7 @@
 	#if __i386__
 		// fast stubs pass NULL for mh and image is instead found via the location of stub (aka lazyPointer)
 		if ( mh == NULL )
-			target = dyld::findImageContainingAddressThreadSafe(lazyPointer);
+			target = dyld::findImageContainingAddress(lazyPointer);
 		else
 			target = dyld::findImageByMachHeader(mh);
 	#else
@@ -1723,29 +4043,67 @@
 		target = dyld::findImageByMachHeader(mh);
 	#endif
 		if ( target == NULL )
-			throw "image not found for lazy pointer";
+			throwf("image not found for lazy pointer at %p", lazyPointer);
 		result = target->doBindLazySymbol(lazyPointer, gLinkContext);
 	}
 	catch (const char* message) {
-		fprintf(stderr, "dyld: lazy symbol binding failed: %s\n", message);
+		dyld::log("dyld: lazy symbol binding failed: %s\n", message);
 		halt(message);
 	}
 	// release read-lock on dyld's data structures
 #if 0
-	if ( gThreadHelpers != NULL ) 
-		(*gThreadHelpers->unlockForReading)();
+	if ( gLibSystemHelpers != NULL ) 
+		(*gLibSystemHelpers->unlockForReading)();
 #endif
 	// return target address to glue which jumps to it with real parameters restored
 	return result;
 }
 
 
-// SPI used by ZeroLink to lazy load bundles
-void registerZeroLinkHandlers(BundleNotificationCallBack notify, BundleLocatorCallBack locate)
-{
-	sBundleNotifier = notify;
-	sBundleLocation = locate;
-}
+uintptr_t fastBindLazySymbol(ImageLoader** imageLoaderCache, uintptr_t lazyBindingInfoOffset)
+{
+	uintptr_t result = 0;
+	// get image 
+	if ( *imageLoaderCache == NULL ) {
+		// save in cache
+		*imageLoaderCache = dyld::findMappedRange((uintptr_t)imageLoaderCache);
+		if ( *imageLoaderCache == NULL ) {
+#if SUPPORT_ACCELERATE_TABLES
+		if ( sAllCacheImagesProxy != NULL ) {
+			const mach_header* mh;
+			const char* path;
+			unsigned index;
+			if ( sAllCacheImagesProxy->addressInCache(imageLoaderCache, &mh, &path, &index) ) {
+				result = sAllCacheImagesProxy->bindLazy(lazyBindingInfoOffset, gLinkContext, mh, index);
+				if ( result == 0 ) {
+					halt("dyld: lazy symbol binding failed for image in dyld shared\n");
+				}
+				return result;
+			}
+		}
+#endif
+			const char* message = "fast lazy binding from unknown image";
+			dyld::log("dyld: %s\n", message);
+			halt(message);
+		}
+	}
+	
+	// bind lazy pointer and return it
+	try {
+		result = (*imageLoaderCache)->doBindFastLazySymbol((uint32_t)lazyBindingInfoOffset, gLinkContext, 
+								(dyld::gLibSystemHelpers != NULL) ? dyld::gLibSystemHelpers->acquireGlobalDyldLock : NULL,
+								(dyld::gLibSystemHelpers != NULL) ? dyld::gLibSystemHelpers->releaseGlobalDyldLock : NULL);
+	}
+	catch (const char* message) {
+		dyld::log("dyld: lazy symbol binding failed: %s\n", message);
+		halt(message);
+	}
+
+	// return target address to glue which jumps to it with real parameters restored
+	return result;
+}
+
+
 
 void registerUndefinedHandler(UndefinedHandler handler)
 {
@@ -1759,67 +4117,59 @@
 	}
 }
 
-static bool findExportedSymbol(const char* name, bool onlyInCoalesced, const ImageLoader::Symbol** sym, ImageLoader** image)
-{
-	// try ZeroLink short cut to finding bundle which exports this symbol
-	if ( sBundleLocation != NULL ) {
-		ImageLoader* zlImage = (*sBundleLocation)(name);
-		if ( zlImage == ((ImageLoader*)(-1)) ) {
-			// -1 is magic value that request symbol is in a bundle not yet linked into process
-			// try calling handler to link in that symbol
-			undefinedHandler(name);
-			// call locator again
-			zlImage = (*sBundleLocation)(name);
-		}
-		// if still not found, then ZeroLink has no idea where to find it
-		if ( zlImage == ((ImageLoader*)(-1)) ) 
-			return false;
-		if ( zlImage != NULL ) {
-			// ZeroLink cache knows where the symbol is
-			*sym = zlImage->findExportedSymbol(name, NULL, false, image);
+static bool findExportedSymbol(const char* name, bool onlyInCoalesced, const ImageLoader::Symbol** sym, const ImageLoader** image, ImageLoader::CoalesceNotifier notifier=NULL)
+{
+	// search all images in order
+	const ImageLoader* firstWeakImage = NULL;
+	const ImageLoader::Symbol* firstWeakSym = NULL;
+	const ImageLoader* firstNonWeakImage = NULL;
+	const ImageLoader::Symbol* firstNonWeakSym = NULL;
+	const size_t imageCount = sAllImages.size();
+	for(size_t i=0; i < imageCount; ++i) {
+		ImageLoader* anImage = sAllImages[i];
+		// the use of inserted libraries alters search order
+		// so that inserted libraries are found before the main executable
+		if ( sInsertedDylibCount > 0 ) {
+			if ( i < sInsertedDylibCount )
+				anImage = sAllImages[i+1];
+			else if ( i == sInsertedDylibCount )
+				anImage = sAllImages[0];
+		}
+		//dyld::log("findExportedSymbol(%s) looking at %s\n", name, anImage->getPath());
+		if ( ! anImage->hasHiddenExports() && (!onlyInCoalesced || anImage->hasCoalescedExports()) ) {
+			const ImageLoader* foundInImage;
+			*sym = anImage->findExportedSymbol(name, false, &foundInImage);
+			//dyld::log("findExportedSymbol(%s) found: sym=%p, anImage=%p, foundInImage=%p\n", name, *sym, anImage, foundInImage /*, (foundInImage ? foundInImage->getPath() : "")*/);
 			if ( *sym != NULL ) {
-				*image = zlImage;
-				return true;
-			}
-		}
-		else {
-			// ZeroLink says it is in some bundle already loaded, but not linked, walk them all
-			const unsigned int imageCount = sAllImages.size();
-			for(unsigned int i=0; i < imageCount; ++i){
-				ImageLoader* anImage = sAllImages[i];
-				if ( anImage->isBundle() && !anImage->hasHiddenExports() ) {
-					//fprintf(stderr, "dyld: search for %s in %s\n", name, anImage->getPath());
-					*sym = anImage->findExportedSymbol(name, NULL, false, image);
-					if ( *sym != NULL ) {
-						return true;
-					}
-				}
-			}
-		}
-	}
-
-	// search all images in order
-	ImageLoader* firstWeakImage = NULL;
-	const ImageLoader::Symbol* firstWeakSym = NULL;
-	const unsigned int imageCount = sAllImages.size();
-	for(unsigned int i=0; i < imageCount; ++i){
-		ImageLoader* anImage = sAllImages[i];
-		if ( ! anImage->hasHiddenExports() && (!onlyInCoalesced || anImage->hasCoalescedExports()) ) {
-			*sym = anImage->findExportedSymbol(name, NULL, false, image);
-			if ( *sym != NULL ) {
+				if ( notifier && (foundInImage == anImage) )
+					notifier(*sym, foundInImage, foundInImage->machHeader());
 				// if weak definition found, record first one found
-				if ( ((*image)->getExportedSymbolInfo(*sym) & ImageLoader::kWeakDefinition) != 0 ) {
+				if ( (foundInImage->getExportedSymbolInfo(*sym) & ImageLoader::kWeakDefinition) != 0 ) {
 					if ( firstWeakImage == NULL ) {
-						firstWeakImage = *image;
+						firstWeakImage = foundInImage;
 						firstWeakSym = *sym;
 					}
 				}
 				else {
-					// found non-weak, so immediately return with it
-					return true;
+					// found non-weak
+					if ( !onlyInCoalesced ) {
+						// for flat lookups, return first found
+						*image = foundInImage;
+						return true;
+					}
+					if ( firstNonWeakImage == NULL ) {
+						firstNonWeakImage = foundInImage;
+						firstNonWeakSym = *sym;
+					}
 				}
 			}
 		}
+	}
+	if ( firstNonWeakImage != NULL ) {
+		// found a weak definition, but no non-weak, so return first weak found
+		*sym = firstNonWeakSym;
+		*image = firstNonWeakImage;
+		return true;
 	}
 	if ( firstWeakSym != NULL ) {
 		// found a weak definition, but no non-weak, so return first weak found
@@ -1827,30 +4177,36 @@
 		*image = firstWeakImage;
 		return true;
 	}
-	
+#if SUPPORT_ACCELERATE_TABLES
+	if ( sAllCacheImagesProxy != NULL ) {
+		if ( sAllCacheImagesProxy->flatFindSymbol(name, onlyInCoalesced, sym, image, notifier) )
+			return true;
+	}
+#endif
+
 	return false;
 }
 
-bool flatFindExportedSymbol(const char* name, const ImageLoader::Symbol** sym, ImageLoader** image)
+bool flatFindExportedSymbol(const char* name, const ImageLoader::Symbol** sym, const ImageLoader** image)
 {
 	return findExportedSymbol(name, false, sym, image);
 }
 
-bool findCoalescedExportedSymbol(const char* name, const ImageLoader::Symbol** sym, ImageLoader** image)
-{
-	return findExportedSymbol(name, true, sym, image);
-}
-
-
-bool flatFindExportedSymbolWithHint(const char* name, const char* librarySubstring, const ImageLoader::Symbol** sym, ImageLoader** image)
+bool findCoalescedExportedSymbol(const char* name, const ImageLoader::Symbol** sym, const ImageLoader** image, ImageLoader::CoalesceNotifier notifier)
+{
+	return findExportedSymbol(name, true, sym, image, notifier);
+}
+
+
+bool flatFindExportedSymbolWithHint(const char* name, const char* librarySubstring, const ImageLoader::Symbol** sym, const ImageLoader** image)
 {
 	// search all images in order
-	const unsigned int imageCount = sAllImages.size();
-	for(unsigned int i=0; i < imageCount; ++i){
+	const size_t imageCount = sAllImages.size();
+	for(size_t i=0; i < imageCount; ++i){
 		ImageLoader* anImage = sAllImages[i];
 		// only look at images whose paths contain the hint string (NULL hint string is wildcard)
 		if ( ! anImage->isBundle() && ((librarySubstring==NULL) || (strstr(anImage->getPath(), librarySubstring) != NULL)) ) {
-			*sym = anImage->findExportedSymbol(name, NULL, false, image);
+			*sym = anImage->findExportedSymbol(name, false, image);
 			if ( *sym != NULL ) {
 				return true;
 			}
@@ -1859,114 +4215,1667 @@
 	return false;
 }
 
-static void getMappedRegions(ImageLoader::RegionsVector& regions)
-{
-	const unsigned int imageCount = sAllImages.size();
-	for(unsigned int i=0; i < imageCount; ++i){
-		ImageLoader* anImage = sAllImages[i];
-		anImage->addMappedRegions(regions);
-	}
-}
-
-
-static ImageLoader* libraryLocator(const char* libraryName, bool search, const char* origin, const char* rpath[])
+
+unsigned int getCoalescedImages(ImageLoader* images[], unsigned imageIndex[])
+{
+	unsigned int count = 0;
+	for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+		ImageLoader* image = *it;
+		if ( image->participatesInCoalescing() ) {
+			images[count] = *it;
+			imageIndex[count] = 0;
+			++count;
+		}
+	}
+#if SUPPORT_ACCELERATE_TABLES
+	if ( sAllCacheImagesProxy != NULL ) {
+		sAllCacheImagesProxy->appendImagesNeedingCoalescing(images, imageIndex, count);
+	}
+#endif
+	return count;
+}
+
+
+static ImageLoader::MappedRegion* getMappedRegions(ImageLoader::MappedRegion* regions)
+{
+	ImageLoader::MappedRegion* end = regions;
+	for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+		(*it)->getMappedRegions(end);
+	}
+	return end;
+}
+
+void registerImageStateSingleChangeHandler(dyld_image_states state, dyld_image_state_change_handler handler)
+{
+	// mark the image that the handler is in as never-unload because dyld has a reference into it
+	ImageLoader* handlerImage = findImageContainingAddress((void*)handler);
+	if ( handlerImage != NULL )
+		handlerImage->setNeverUnload();
+
+	// add to list of handlers
+	std::vector<dyld_image_state_change_handler>* handlers = stateToHandlers(state, sSingleHandlers);
+	if ( handlers != NULL ) {
+        // <rdar://problem/10332417> need updateAllImages() to be last in dyld_image_state_mapped list
+        // so that if ObjC adds a handler that prevents a load, it happens before the gdb list is updated
+        if ( state == dyld_image_state_mapped )
+            handlers->insert(handlers->begin(), handler);
+        else
+            handlers->push_back(handler);
+
+		// call callback with all existing images
+		for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+			ImageLoader* image = *it;
+			dyld_image_info	 info;
+			info.imageLoadAddress	= image->machHeader();
+			info.imageFilePath		= image->getRealPath();
+			info.imageFileModDate	= image->lastModified();
+			// should only call handler if state == image->state
+			if ( image->getState() == state )
+				(*handler)(state, 1, &info);
+			// ignore returned string, too late to do anything
+		}
+	}
+}
+
+void registerImageStateBatchChangeHandler(dyld_image_states state, dyld_image_state_change_handler handler)
+{
+	// mark the image that the handler is in as never-unload because dyld has a reference into it
+	ImageLoader* handlerImage = findImageContainingAddress((void*)handler);
+	if ( handlerImage != NULL )
+		handlerImage->setNeverUnload();
+
+	// add to list of handlers
+	std::vector<dyld_image_state_change_handler>* handlers = stateToHandlers(state, sBatchHandlers);
+	if ( handlers != NULL ) {
+		// insert at front, so that gdb handler is always last
+		handlers->insert(handlers->begin(), handler);
+		
+		// call callback with all existing images
+		try {
+			notifyBatchPartial(state, true, handler, false, false);
+		}
+		catch (const char* msg) {
+			// ignore request to abort during registration
+		}
+	}
+}
+
+
+void registerObjCNotifiers(_dyld_objc_notify_mapped mapped, _dyld_objc_notify_init init, _dyld_objc_notify_unmapped unmapped)
+{
+	// record functions to call
+	sNotifyObjCMapped	= mapped;
+	sNotifyObjCInit		= init;
+	sNotifyObjCUnmapped = unmapped;
+
+	// call 'mapped' function with all images mapped so far
+	try {
+		notifyBatchPartial(dyld_image_state_bound, true, NULL, false, true);
+	}
+	catch (const char* msg) {
+		// ignore request to abort during registration
+	}
+
+	// <rdar://problem/32209809> call 'init' function on all images already init'ed (below libSystem)
+	for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+		ImageLoader* image = *it;
+		if ( (image->getState() == dyld_image_state_initialized) && image->notifyObjC() ) {
+			dyld3::ScopedTimer timer(DBG_DYLD_TIMING_OBJC_INIT, (uint64_t)image->machHeader(), 0, 0);
+			(*sNotifyObjCInit)(image->getRealPath(), image->machHeader());
+		}
+	}
+}
+
+bool sharedCacheUUID(uuid_t uuid)
+{
+	if ( sSharedCacheLoadInfo.loadAddress == nullptr )
+		return false;
+
+	sSharedCacheLoadInfo.loadAddress->getUUID(uuid);
+	return true;
+}
+
+#if SUPPORT_ACCELERATE_TABLES
+
+bool dlopenFromCache(const char* path, int mode, void** handle)
+{
+	if ( sAllCacheImagesProxy == NULL )
+		return false;
+	char fallbackPath[PATH_MAX];
+	bool result = sAllCacheImagesProxy->dlopenFromCache(gLinkContext, path, mode, handle);
+	if ( !result && (strchr(path, '/') == NULL) ) {
+		// POSIX says you can call dlopen() with a leaf name (e.g. dlopen("libz.dylb"))
+		strcpy(fallbackPath, "/usr/lib/");
+		strlcat(fallbackPath, path, PATH_MAX);
+		result = sAllCacheImagesProxy->dlopenFromCache(gLinkContext, fallbackPath, mode, handle);
+		if ( !result )
+			path = fallbackPath;
+	}
+	if ( !result ) {
+		// leaf name could be a symlink
+		char resolvedPath[PATH_MAX];
+		realpath(path, resolvedPath);
+		int realpathErrno = errno;
+		// If realpath() resolves to a path which does not exist on disk, errno is set to ENOENT
+		if ( (realpathErrno == ENOENT) || (realpathErrno == 0) ) {
+			result = sAllCacheImagesProxy->dlopenFromCache(gLinkContext, resolvedPath, mode, handle);
+		}
+	}
+
+	return result;
+}
+
+bool makeCacheHandle(ImageLoader* image, unsigned cacheIndex, int mode, void** result)
+{
+	if ( sAllCacheImagesProxy == NULL )
+		return false;
+	return sAllCacheImagesProxy->makeCacheHandle(gLinkContext, cacheIndex, mode, result);
+}
+
+bool isCacheHandle(void* handle)
+{
+	if ( sAllCacheImagesProxy == NULL )
+		return false;
+	return sAllCacheImagesProxy->isCacheHandle(handle, NULL, NULL);
+}
+
+bool isPathInCache(const char* path)
+{
+	if ( sAllCacheImagesProxy == NULL )
+		return false;
+	unsigned index;
+	return sAllCacheImagesProxy->hasDylib(path, &index);
+}
+
+const char* getPathFromIndex(unsigned cacheIndex)
+{
+	if ( sAllCacheImagesProxy == NULL )
+		return NULL;
+	return sAllCacheImagesProxy->getIndexedPath(cacheIndex);
+}
+
+void* dlsymFromCache(void* handle, const char* symName, unsigned index)
+{
+	if ( sAllCacheImagesProxy == NULL )
+		return NULL;
+	return sAllCacheImagesProxy->dlsymFromCache(gLinkContext, handle, symName, index);
+}
+
+bool addressInCache(const void* address, const mach_header** mh, const char** path, unsigned* index)
+{
+	if ( sAllCacheImagesProxy == NULL )
+		return false;
+	unsigned ignore;
+	return sAllCacheImagesProxy->addressInCache(address, mh, path, index ? index : &ignore);
+}
+
+bool findUnwindSections(const void* addr, dyld_unwind_sections* info)
+{
+	if ( sAllCacheImagesProxy == NULL )
+		return false;
+	return sAllCacheImagesProxy->findUnwindSections(addr, info);
+}
+
+bool dladdrFromCache(const void* address, Dl_info* info)
+{
+	if ( sAllCacheImagesProxy == NULL )
+		return false;
+	return sAllCacheImagesProxy->dladdrFromCache(address, info);
+}
+#endif
+
+static ImageLoader* libraryLocator(const char* libraryName, bool search, const char* origin, const ImageLoader::RPathChain* rpaths, bool enforceIOSMac, unsigned& cacheIndex)
 {
 	dyld::LoadContext context;
 	context.useSearchPaths		= search;
+	context.useFallbackPaths	= search;
 	context.useLdLibraryPath	= false;
+	context.implicitRPath		= false;
+	context.matchByInstallName	= false;
 	context.dontLoad			= false;
 	context.mustBeBundle		= false;
 	context.mustBeDylib			= true;
-	context.matchByInstallName	= false;
+	context.canBePIE			= false;
+	context.enforceIOSMac		= enforceIOSMac;
 	context.origin				= origin;
-	context.rpath				= rpath;
-	return load(libraryName, context);
-}
-
-	
-static void setContext(int argc, const char* argv[], const char* envp[], const char* apple[])
+	context.rpath				= rpaths;
+	return load(libraryName, context, cacheIndex);
+}
+
+static const char* basename(const char* path)
+{
+    const char* last = path;
+    for (const char* s = path; *s != '\0'; s++) {
+        if (*s == '/') 
+			last = s+1;
+    }
+    return last;
+}
+
+static void setContext(const macho_header* mainExecutableMH, int argc, const char* argv[], const char* envp[], const char* apple[])
 {
 	gLinkContext.loadLibrary			= &libraryLocator;
-	gLinkContext.imageNotification		= &imageNotification;
 	gLinkContext.terminationRecorder	= &terminationRecorder;
 	gLinkContext.flatExportFinder		= &flatFindExportedSymbol;
 	gLinkContext.coalescedExportFinder	= &findCoalescedExportedSymbol;
+	gLinkContext.getCoalescedImages		= &getCoalescedImages;
 	gLinkContext.undefinedHandler		= &undefinedHandler;
-	gLinkContext.addImageNeedingNotification = &addImageNeedingNotification;
-	gLinkContext.notifyAdding			= &notifyAdding;
 	gLinkContext.getAllMappedRegions	= &getMappedRegions;
 	gLinkContext.bindingHandler			= NULL;
+	gLinkContext.notifySingle			= &notifySingle;
+	gLinkContext.notifyBatch			= &notifyBatch;
+	gLinkContext.removeImage			= &removeImage;
+	gLinkContext.registerDOFs			= &registerDOFs;
+	gLinkContext.clearAllDepths			= &clearAllDepths;
+	gLinkContext.printAllDepths			= &printAllDepths;
+	gLinkContext.imageCount				= &imageCount;
+	gLinkContext.setNewProgramVars		= &setNewProgramVars;
+	gLinkContext.inSharedCache			= &inSharedCache;
+	gLinkContext.setErrorStrings		= &setErrorStrings;
+#if SUPPORT_OLD_CRT_INITIALIZATION
+	gLinkContext.setRunInitialzersOldWay= &setRunInitialzersOldWay;
+#endif
+	gLinkContext.findImageContainingAddress	= &findImageContainingAddress;
+	gLinkContext.addDynamicReference	= &addDynamicReference;
+#if SUPPORT_ACCELERATE_TABLES
+	gLinkContext.notifySingleFromCache	= &notifySingleFromCache;
+	gLinkContext.getPreInitNotifyHandler= &getPreInitNotifyHandler;
+	gLinkContext.getBoundBatchHandler   = &getBoundBatchHandler;
+#endif
 	gLinkContext.bindingOptions			= ImageLoader::kBindingNone;
-	gLinkContext.mainExecutable			= sMainExecutable;
 	gLinkContext.argc					= argc;
 	gLinkContext.argv					= argv;
 	gLinkContext.envp					= envp;
 	gLinkContext.apple					= apple;
-}
-
-static bool checkEmulation()
-{
-#if __i386__
-	int mib[] = { CTL_KERN, KERN_CLASSIC, getpid() };
-	int is_classic = 0;
-	size_t len = sizeof(int);
-	int ret = sysctl(mib, 3, &is_classic, &len, NULL, 0);
-	if ((ret != -1) && is_classic) {
-		// When a 32-bit ppc program is run under emulation on an Intel processor,
-		// we want any i386 dylibs (e.g. the emulator) to not load in the shared region
-		// because the shared region is being used by ppc dylibs
-		gLinkContext.sharedRegionMode = ImageLoader::kDontUseSharedRegion;
-		return true;
-	}
-#endif
+	gLinkContext.progname				= (argv[0] != NULL) ? basename(argv[0]) : "";
+	gLinkContext.programVars.mh			= mainExecutableMH;
+	gLinkContext.programVars.NXArgcPtr	= &gLinkContext.argc;
+	gLinkContext.programVars.NXArgvPtr	= &gLinkContext.argv;
+	gLinkContext.programVars.environPtr	= &gLinkContext.envp;
+	gLinkContext.programVars.__prognamePtr=&gLinkContext.progname;
+	gLinkContext.mainExecutable			= NULL;
+	gLinkContext.imageSuffix			= NULL;
+	gLinkContext.dynamicInterposeArray	= NULL;
+	gLinkContext.dynamicInterposeCount	= 0;
+	gLinkContext.prebindUsage			= ImageLoader::kUseAllPrebinding;
+#if TARGET_IPHONE_SIMULATOR
+	gLinkContext.sharedRegionMode		= ImageLoader::kUsePrivateSharedRegion;
+#else
+	gLinkContext.sharedRegionMode		= ImageLoader::kUseSharedRegion;
+#endif
+}
+
+
+
+//
+// Look for a special segment in the mach header. 
+// Its presences means that the binary wants to have DYLD ignore
+// DYLD_ environment variables.
+//
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+static bool hasRestrictedSegment(const macho_header* mh)
+{
+	const uint32_t cmd_count = mh->ncmds;
+	const struct load_command* const cmds = (struct load_command*)(((char*)mh)+sizeof(macho_header));
+	const struct load_command* cmd = cmds;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		switch (cmd->cmd) {
+			case LC_SEGMENT_COMMAND:
+			{
+				const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+				
+				//dyld::log("seg name: %s\n", seg->segname);
+				if (strcmp(seg->segname, "__RESTRICT") == 0) {
+					const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+					const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
+					for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+						if (strcmp(sect->sectname, "__restrict") == 0) 
+							return true;
+					}
+				}
+			}
+			break;
+		}
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+	}
+		
 	return false;
 }
-
-void link(ImageLoader* image, ImageLoader::BindingLaziness bindness, ImageLoader::InitializerRunning runInitializers)
+#endif
+
+#if __IPHONE_OS_VERSION_MIN_REQUIRED && !TARGET_IPHONE_SIMULATOR
+static bool isFairPlayEncrypted(const macho_header* mh)
+{
+	const uint32_t cmd_count = mh->ncmds;
+	const struct load_command* const cmds = (struct load_command*)(((char*)mh)+sizeof(macho_header));
+	const struct load_command* cmd = cmds;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		if ( cmd->cmd == LC_ENCRYPT_COMMAND ) {
+			const encryption_info_command* enc = (encryption_info_command*)cmd;
+			return (enc->cryptid != 0);
+		}
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+	}
+
+	return false;
+}
+#endif
+
+#if SUPPORT_VERSIONED_PATHS
+
+static bool readFirstPage(const char* dylibPath, uint8_t firstPage[4096]) 
+{
+	firstPage[0] = 0;
+	// open file (automagically closed when this function exits)
+	FileOpener file(dylibPath);
+
+	if ( file.getFileDescriptor() == -1 ) 
+		return false;
+	
+	if ( pread(file.getFileDescriptor(), firstPage, 4096, 0) != 4096 )
+		return false;
+
+	// if fat wrapper, find usable sub-file
+	const fat_header* fileStartAsFat = (fat_header*)firstPage;
+	if ( fileStartAsFat->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
+		uint64_t fileOffset;
+		uint64_t fileLength;
+		if ( fatFindBest(fileStartAsFat, &fileOffset, &fileLength) ) {
+			if ( pread(file.getFileDescriptor(), firstPage, 4096, fileOffset) != 4096 )
+				return false;
+		}
+		else {
+			return false;
+		}
+	}
+	
+	return true;
+}
+
+//
+// Peeks at a dylib file and returns its current_version and install_name.
+// Returns false on error.
+//
+static bool getDylibVersionAndInstallname(const char* dylibPath, uint32_t* version, char* installName)
+{
+	uint8_t firstPage[4096];
+	const macho_header* mh = (macho_header*)firstPage;
+	if ( !readFirstPage(dylibPath, firstPage) ) {
+		// If file cannot be read, check to see if path is in shared cache
+		const macho_header* mhInCache;
+		const char*			pathInCache;
+		long				slideInCache;
+		if ( !findInSharedCacheImage(dylibPath, true, NULL, &mhInCache, &pathInCache, &slideInCache) )
+			return false;
+		mh = mhInCache;
+	}
+
+	// check mach-o header
+	if ( mh->magic != sMainExecutableMachHeader->magic ) 
+		return false;
+	if ( mh->cputype != sMainExecutableMachHeader->cputype )
+		return false;
+
+	// scan load commands for LC_ID_DYLIB
+	const uint32_t cmd_count = mh->ncmds;
+	const struct load_command* const cmds = (struct load_command*)(((char*)mh)+sizeof(macho_header));
+	const struct load_command* const cmdsReadEnd = (struct load_command*)(((char*)mh)+4096);
+	const struct load_command* cmd = cmds;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		switch (cmd->cmd) {
+			case LC_ID_DYLIB:
+			{
+				const struct dylib_command* id = (struct dylib_command*)cmd;
+				*version = id->dylib.current_version;
+				if ( installName != NULL )
+					strlcpy(installName, (char *)id + id->dylib.name.offset, PATH_MAX);
+				return true;
+			}
+			break;
+		}
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+		if ( cmd > cmdsReadEnd )
+			return false;
+	}
+	
+	return false;
+}
+#endif // SUPPORT_VERSIONED_PATHS
+						
+
+#if 0
+static void printAllImages()
+{
+	dyld::log("printAllImages()\n");
+	for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+		ImageLoader* image = *it;
+		dyld_image_states imageState = image->getState();
+		dyld::log("  state=%d, dlopen-count=%d, never-unload=%d, in-use=%d, name=%s\n",
+				  imageState, image->dlopenCount(), image->neverUnload(), image->isMarkedInUse(), image->getShortName());
+	}
+}
+#endif
+
+void link(ImageLoader* image, bool forceLazysBound, bool neverUnload, const ImageLoader::RPathChain& loaderRPaths, unsigned cacheIndex)
 {
 	// add to list of known images.  This did not happen at creation time for bundles
-	if ( image->isBundle() )
+	if ( image->isBundle() && !image->isLinked() )
 		addImage(image);
 
 	// we detect root images as those not linked in yet 
 	if ( !image->isLinked() )
 		addRootImage(image);
 	
-	// notify ZeroLink of new image with concat of logical and physical name
-	if ( sBundleNotifier != NULL && image->isBundle() ) {
-		const int logicalLen = strlen(image->getLogicalPath());
-		char logAndPhys[strlen(image->getPath())+logicalLen+2];
-		strcpy(logAndPhys, image->getLogicalPath());
-		strcpy(&logAndPhys[logicalLen+1], image->getPath());
-		(*sBundleNotifier)(logAndPhys, image);
-	}
-
 	// process images
 	try {
-		image->link(gLinkContext, bindness, runInitializers, sAddImageCallbacks.size());
+		const char* path = image->getPath();
+#if SUPPORT_ACCELERATE_TABLES
+		if ( image == sAllCacheImagesProxy )
+			path = sAllCacheImagesProxy->getIndexedPath(cacheIndex);
+#endif
+		image->link(gLinkContext, forceLazysBound, false, neverUnload, loaderRPaths, path);
 	}
 	catch (const char* msg) {
-		sAllImagesMightContainUnlinkedImages = true;
-		throw msg;
+		garbageCollectImages();
+		throw;
+	}
+}
+
+
+void runInitializers(ImageLoader* image)
+{
+	// do bottom up initialization
+	ImageLoader::InitializerTimingList initializerTimes[allImagesCount()];
+	initializerTimes[0].count = 0;
+	image->runInitializers(gLinkContext, initializerTimes[0]);
+}
+
+// This function is called at the end of dlclose() when the reference count goes to zero.
+// The dylib being unloaded may have brought in other dependent dylibs when it was loaded.
+// Those dependent dylibs need to be unloaded, but only if they are not referenced by
+// something else.  We use a standard mark and sweep garbage collection.
+//
+// The tricky part is that when a dylib is unloaded it may have a termination function that
+// can run and itself call dlclose() on yet another dylib.  The problem is that this
+// sort of gabage collection is not re-entrant.  Instead a terminator's call to dlclose()
+// which calls garbageCollectImages() will just set a flag to re-do the garbage collection
+// when the current pass is done.
+//
+// Also note that this is done within the dyld global lock, so it is always single threaded.
+//
+void garbageCollectImages()
+{
+	static bool sDoingGC = false;
+	static bool sRedo = false;
+
+	if ( sDoingGC ) {
+		// GC is currently being run, just set a flag to have it run again.
+		sRedo = true;
+		return;
 	}
 	
-#if OLD_GDB_DYLD_INTERFACE
-	// notify gdb that loaded libraries have changed
-	gdb_dyld_state_changed();
-#endif
-}
-
-
+	sDoingGC = true;
+	do {
+		sRedo = false;
+		
+		// mark phase: mark all images not-in-use
+		for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+			ImageLoader* image = *it;
+			//dyld::log("gc: neverUnload=%d name=%s\n", image->neverUnload(), image->getShortName());
+			image->markNotUsed();
+		}
+		
+		// sweep phase: mark as in-use, images reachable from never-unload or in-use image
+		for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+			ImageLoader* image = *it;
+			if ( (image->dlopenCount() != 0) || image->neverUnload() || (image == sMainExecutable) ) {
+				OSSpinLockLock(&sDynamicReferencesLock);
+					image->markedUsedRecursive(sDynamicReferences);
+				OSSpinLockUnlock(&sDynamicReferencesLock);
+			}
+		}
+
+		// collect phase: build array of images not marked in-use
+		ImageLoader* deadImages[sAllImages.size()];
+		unsigned deadCount = 0;
+		int maxRangeCount = 0;
+		for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+			ImageLoader* image = *it;
+			if ( ! image->isMarkedInUse() ) {
+				deadImages[deadCount++] = image;
+				if (gLogAPIs) dyld::log("dlclose(), found unused image %p %s\n", image, image->getShortName());
+				maxRangeCount += image->segmentCount();
+			}
+		}
+
+		// collect phase: run termination routines for images not marked in-use
+		if ( maxRangeCount != 0 ) {
+			__cxa_range_t ranges[maxRangeCount];
+			int rangeCount = 0;
+			for (unsigned i=0; i < deadCount; ++i) {
+				ImageLoader* image = deadImages[i];
+				for (unsigned int j=0; j < image->segmentCount(); ++j) {
+					if ( !image->segExecutable(j) )
+						continue;
+					if ( rangeCount < maxRangeCount ) {
+						ranges[rangeCount].addr = (const void*)image->segActualLoadAddress(j);
+						ranges[rangeCount].length = image->segSize(j);
+						++rangeCount;
+					}
+				}
+				try {
+					runImageStaticTerminators(image);
+				}
+				catch (const char* msg) {
+					dyld::warn("problem running terminators for image: %s\n", msg);
+				}
+			}
+
+			// <rdar://problem/14718598> dyld should call __cxa_finalize_ranges()
+			if ( (rangeCount > 0) && (gLibSystemHelpers != NULL) && (gLibSystemHelpers->version >= 13) )
+				(*gLibSystemHelpers->cxa_finalize_ranges)(ranges, rangeCount);
+		}
+
+		// collect phase: delete all images which are not marked in-use
+		bool mightBeMore;
+		do {
+			mightBeMore = false;
+			for (std::vector<ImageLoader*>::iterator it=sAllImages.begin(); it != sAllImages.end(); it++) {
+				ImageLoader* image = *it;
+				if ( ! image->isMarkedInUse() ) {
+					try {
+						if (gLogAPIs) dyld::log("dlclose(), deleting %p %s\n", image, image->getShortName());
+						removeImage(image);
+						ImageLoader::deleteImage(image);
+						mightBeMore = true;
+						break;  // interator in invalidated by this removal
+					}
+					catch (const char* msg) {
+						dyld::warn("problem deleting image: %s\n", msg);
+					}
+				}
+			}
+		} while ( mightBeMore );
+	} while (sRedo);
+	sDoingGC = false;
+
+	//printAllImages();
+
+}
+
+
+static void preflight_finally(ImageLoader* image)
+{
+	if ( image->isBundle() ) {
+		removeImageFromAllImages(image->machHeader());
+		ImageLoader::deleteImage(image);
+	}
+	sBundleBeingLoaded = NULL;
+	dyld::garbageCollectImages();
+}
+
+
+void preflight(ImageLoader* image, const ImageLoader::RPathChain& loaderRPaths, unsigned cacheIndex)
+{
+	try {
+		if ( image->isBundle() ) 
+			sBundleBeingLoaded = image;	// hack
+		const char* path = image->getPath();
+#if SUPPORT_ACCELERATE_TABLES
+		if ( image == sAllCacheImagesProxy )
+			path = sAllCacheImagesProxy->getIndexedPath(cacheIndex);
+#endif
+		image->link(gLinkContext, false, true, false, loaderRPaths, path);
+	}
+	catch (const char* msg) {	
+		preflight_finally(image);
+		throw;
+	}
+	preflight_finally(image);
+}
+
+static void loadInsertedDylib(const char* path)
+{
+	ImageLoader* image = NULL;
+	unsigned cacheIndex;
+	try {
+		LoadContext context;
+		context.useSearchPaths		= false;
+		context.useFallbackPaths	= false;
+		context.useLdLibraryPath	= false;
+		context.implicitRPath		= false;
+		context.matchByInstallName	= false;
+		context.dontLoad			= false;
+		context.mustBeBundle		= false;
+		context.mustBeDylib			= true;
+		context.canBePIE			= false;
+		context.enforceIOSMac		= true;
+		context.origin				= NULL;	// can't use @loader_path with DYLD_INSERT_LIBRARIES
+		context.rpath				= NULL;
+		image = load(path, context, cacheIndex);
+	}
+	catch (const char* msg) {
+		if ( gLinkContext.allowInsertFailures )
+			dyld::log("dyld: warning: could not load inserted library '%s' into hardened process because %s\n", path, msg);
+		else
+			halt(dyld::mkstringf("could not load inserted library '%s' because %s\n", path, msg));
+	}
+	catch (...) {
+		halt(dyld::mkstringf("could not load inserted library '%s'\n", path));
+	}
+}
+
+
+static void configureProcessRestrictions(const macho_header* mainExecutableMH)
+{
+	uint64_t amfiInputFlags = 0;
+#if TARGET_IPHONE_SIMULATOR
+	amfiInputFlags |= AMFI_DYLD_INPUT_PROC_IN_SIMULATOR;
+#elif __MAC_OS_X_VERSION_MIN_REQUIRED
+	if ( hasRestrictedSegment(mainExecutableMH) )
+		amfiInputFlags |= AMFI_DYLD_INPUT_PROC_HAS_RESTRICT_SEG;
+#elif __IPHONE_OS_VERSION_MIN_REQUIRED
+	if ( isFairPlayEncrypted(mainExecutableMH) )
+		amfiInputFlags |= AMFI_DYLD_INPUT_PROC_IS_ENCRYPTED;
+#endif
+	uint64_t amfiOutputFlags = 0;
+	if ( amfi_check_dyld_policy_self(amfiInputFlags, &amfiOutputFlags) == 0 ) {
+		gLinkContext.allowAtPaths 				= (amfiOutputFlags & AMFI_DYLD_OUTPUT_ALLOW_AT_PATH);
+		gLinkContext.allowEnvVarsPrint			= (amfiOutputFlags & AMFI_DYLD_OUTPUT_ALLOW_PRINT_VARS);
+		gLinkContext.allowEnvVarsPath			= (amfiOutputFlags & AMFI_DYLD_OUTPUT_ALLOW_PATH_VARS);
+		gLinkContext.allowEnvVarsSharedCache	= (amfiOutputFlags & AMFI_DYLD_OUTPUT_ALLOW_CUSTOM_SHARED_CACHE);
+		gLinkContext.allowClassicFallbackPaths	= (amfiOutputFlags & AMFI_DYLD_OUTPUT_ALLOW_FALLBACK_PATHS);
+		gLinkContext.allowInsertFailures    	= (amfiOutputFlags & AMFI_DYLD_OUTPUT_ALLOW_FAILED_LIBRARY_INSERTION);
+	}
+	else {
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+		// support chrooting from old kernel
+		bool isRestricted = false;
+		bool libraryValidation = false;
+		// any processes with setuid or setgid bit set or with __RESTRICT segment is restricted
+		if ( issetugid() || hasRestrictedSegment(mainExecutableMH) ) {
+			isRestricted = true;
+		}
+		bool usingSIP = (csr_check(CSR_ALLOW_TASK_FOR_PID) != 0);
+		uint32_t flags;
+		if ( csops(0, CS_OPS_STATUS, &flags, sizeof(flags)) != -1 ) {
+			// On OS X CS_RESTRICT means the program was signed with entitlements
+			if ( ((flags & CS_RESTRICT) == CS_RESTRICT) && usingSIP ) {
+				isRestricted = true;
+			}
+			// Library Validation loosens searching but requires everything to be code signed
+			if ( flags & CS_REQUIRE_LV ) {
+				isRestricted = false;
+				libraryValidation = true;
+			}
+		}
+		gLinkContext.allowAtPaths                = !isRestricted;
+		gLinkContext.allowEnvVarsPrint           = !isRestricted;
+		gLinkContext.allowEnvVarsPath            = !isRestricted;
+		gLinkContext.allowEnvVarsSharedCache     = !libraryValidation || !usingSIP;
+		gLinkContext.allowClassicFallbackPaths   = !isRestricted;
+		gLinkContext.allowInsertFailures         = false;
+#else
+		halt("amfi_check_dyld_policy_self() failed\n");
+#endif
+	}
+}
+
+
+bool processIsRestricted()
+{
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+	return !gLinkContext.allowEnvVarsPath;
+#else
+	return false;
+#endif
+}
+
+
+// <rdar://problem/10583252> Add dyld to uuidArray to enable symbolication of stackshots
+static void addDyldImageToUUIDList()
+{
+	const struct macho_header* mh = (macho_header*)&__dso_handle;
+	const uint32_t cmd_count = mh->ncmds;
+	const struct load_command* const cmds = (struct load_command*)((char*)mh + sizeof(macho_header));
+	const struct load_command* cmd = cmds;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		switch (cmd->cmd) {
+			case LC_UUID: {
+				uuid_command* uc = (uuid_command*)cmd;
+				dyld_uuid_info info;
+				info.imageLoadAddress = (mach_header*)mh;
+				memcpy(info.imageUUID, uc->uuid, 16);
+				addNonSharedCacheImageUUID(info);
+				return;
+			}
+		}
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+	}
+}
+
+void notifyKernelAboutImage(const struct macho_header* mh, const char* fileInfo)
+{
+	const char *endptr = nullptr;
+	uint64_t fsid_scalar = hexToUInt64(fileInfo, &endptr);
+	uint64_t fsobj_id_scalar = 0;
+	if (endptr != nullptr) {
+		fsobj_id_scalar = hexToUInt64(endptr+1, &endptr);
+	}
+	const uint32_t cmd_count = mh->ncmds;
+	const struct load_command* const cmds = (struct load_command*)((char*)mh + sizeof(macho_header));
+	const struct load_command* cmd = cmds;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		switch (cmd->cmd) {
+			case LC_UUID: {
+				// Add dyld to the kernel image info
+				uuid_command* uc = (uuid_command*)cmd;
+				dyld3::kdebug_trace_dyld_image(DBG_DYLD_UUID_MAP_A, (const uuid_t *)&uc->uuid[0], *reinterpret_cast<fsobj_id_t *>(&fsobj_id_scalar), *reinterpret_cast<fsid_t *>(&fsid_scalar), (const mach_header *)mh);
+				return;
+			}
+		}
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+	}
+}
+
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+typedef int (*open_proc_t)(const char*, int, int);
+typedef int (*fcntl_proc_t)(int, int, void*);
+typedef int (*ioctl_proc_t)(int, unsigned long, void*);
+static void* getProcessInfo() { return dyld::gProcessInfo; }
+static SyscallHelpers sSysCalls = {
+		12,
+		// added in version 1
+		(open_proc_t)&open, 
+		&close, 
+		&pread, 
+		&write, 
+		&mmap, 
+		&munmap, 
+		&madvise,
+		&stat, 
+		(fcntl_proc_t)&fcntl, 
+		(ioctl_proc_t)&ioctl, 
+		&issetugid, 
+		&getcwd, 
+		&realpath, 
+		&vm_allocate, 
+		&vm_deallocate,
+		&vm_protect,
+		&vlog, 
+		&vwarn, 
+		&pthread_mutex_lock, 
+		&pthread_mutex_unlock,
+		&mach_thread_self, 
+		&mach_port_deallocate, 
+		&task_self_trap,
+		&mach_timebase_info,
+		&OSAtomicCompareAndSwapPtrBarrier, 
+		&OSMemoryBarrier,
+		&getProcessInfo,
+		&__error,
+		&mach_absolute_time,
+		// added in version 2
+		&thread_switch,
+		// added in version 3
+		&opendir,
+		&readdir_r,
+		&closedir,
+		// added in version 4
+		&coresymbolication_load_notifier,
+		&coresymbolication_unload_notifier,
+		// Added in version 5
+		&proc_regionfilename,
+		&getpid,
+		&mach_port_insert_right,
+		&mach_port_allocate,
+		&mach_msg,
+		// Added in version 6
+		&abort_with_payload,
+		// Added in version 7
+		&task_register_dyld_image_infos,
+		&task_unregister_dyld_image_infos,
+		&task_get_dyld_image_infos,
+		&task_register_dyld_shared_cache_image_info,
+		&task_register_dyld_set_dyld_state,
+		&task_register_dyld_get_process_state,
+		// Added in version 8
+		&task_info,
+		&thread_info,
+		&kdebug_is_enabled,
+		&kdebug_trace,
+		// Added in version 9
+		&kdebug_trace_string,
+		// Added in version 10
+		&amfi_check_dyld_policy_self,
+		// Added in version 11
+		&notifyMonitoringDyldMain,
+		&notifyMonitoringDyld,
+		// Add in version 12
+		&mach_msg_destroy,
+		&mach_port_construct,
+		&mach_port_destruct
+};
+
+__attribute__((noinline))
+static const char* useSimulatorDyld(int fd, const macho_header* mainExecutableMH, const char* dyldPath,
+								int argc, const char* argv[], const char* envp[], const char* apple[],
+								uintptr_t* startGlue, uintptr_t* mainAddr)
+{
+	*startGlue = 0;
+	*mainAddr = 0;
+
+	// <rdar://35873436> HACK to allow marzipan dyld_sim to run entitled processes
+	if ( strncmp(dyldPath, "/System/", 8) != 0 ) {
+		uint32_t flags;
+		if ( csops(0, CS_OPS_STATUS, &flags, sizeof(flags)) == -1 )
+			return "csops() failed";
+		if ( (flags & CS_RESTRICT) == CS_RESTRICT )
+			return "dyld_sim cannot be loaded in a restricted process";
+	}
+
+	// <rdar://problem/25311921> simulator does not support restricted processes
+	if ( issetugid() )
+		return "dyld_sim cannot be loaded in a setuid process";
+	if ( hasRestrictedSegment(mainExecutableMH) )
+		return "dyld_sim cannot be loaded in a restricted process";
+
+	// get file size of dyld_sim
+	struct stat sb;
+	if ( fstat(fd, &sb) == -1 )
+		return "stat(dyld_sim) failed";
+
+	// read first page of dyld_sim file
+	uint8_t firstPage[4096];
+	if ( pread(fd, firstPage, 4096, 0) != 4096 )
+		return "pread(dyld_sim) failed";
+
+	// if fat file, pick matching slice
+	uint64_t fileOffset = 0;
+	uint64_t fileLength = sb.st_size;
+	const fat_header* fileStartAsFat = (fat_header*)firstPage;
+	if ( fileStartAsFat->magic == OSSwapBigToHostInt32(FAT_MAGIC) ) {
+		if ( !fatFindBest(fileStartAsFat, &fileOffset, &fileLength) ) 
+			return "no matching arch in dyld_sim";
+		// re-read buffer from start of mach-o slice in fat file
+		if ( pread(fd, firstPage, 4096, fileOffset) != 4096 )
+			return "pread(dyld_sim) failed";
+	}
+	else if ( !isCompatibleMachO(firstPage, dyldPath) ) {
+		return "dyld_sim is not compatible with the loaded process, likely due to architecture mismatch";
+	}
+	
+	// calculate total size of dyld segments
+	const macho_header* mh = (const macho_header*)firstPage;
+	struct macho_segment_command* lastSeg = NULL;
+	struct macho_segment_command* firstSeg = NULL;
+	uintptr_t mappingSize = 0;
+	uintptr_t preferredLoadAddress = 0;
+	const uint32_t cmd_count = mh->ncmds;
+	if ( mh->sizeofcmds > 4096 )
+		return "dyld_sim load commands to large";
+	if ( (sizeof(macho_header) + mh->sizeofcmds) > 4096 )
+		return "dyld_sim load commands to large";
+	struct linkedit_data_command* codeSigCmd = NULL;
+	const struct load_command* const cmds = (struct load_command*)(((char*)mh)+sizeof(macho_header));
+	const struct load_command* const endCmds = (struct load_command*)(((char*)mh) + sizeof(macho_header) + mh->sizeofcmds);
+	const struct load_command* cmd = cmds;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		uint32_t cmdLength = cmd->cmdsize;
+		if ( cmdLength < 8 )
+			return "dyld_sim load command too small";
+		const struct load_command* const nextCmd = (const struct load_command*)(((char*)cmd)+cmdLength);
+		if ( (nextCmd > endCmds) || (nextCmd < cmd) )
+			return "dyld_sim load command too large";
+		switch (cmd->cmd) {
+			case LC_SEGMENT_COMMAND:
+				{
+					struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+					if ( seg->vmaddr + seg->vmsize < seg->vmaddr )
+						return "dyld_sim seg wraps address space";
+					if ( seg->vmsize < seg->filesize )
+						return "dyld_sim seg vmsize too small";
+					if ( (seg->fileoff + seg->filesize) < seg->fileoff )
+						return "dyld_sim seg size wraps address space";
+					if ( lastSeg == NULL ) {
+						// first segment must be __TEXT and start at beginning of file/slice
+						firstSeg = seg;
+						if ( strcmp(seg->segname, "__TEXT") != 0 )
+							return "dyld_sim first segment not __TEXT";
+						if ( seg->fileoff != 0 )
+							return "dyld_sim first segment not at file offset zero";
+						if ( seg->filesize < (sizeof(macho_header) + mh->sizeofcmds) )
+							return "dyld_sim first segment smaller than load commands";
+						preferredLoadAddress = seg->vmaddr;
+					}
+					else {
+						// other sements must be continguous with previous segment and not executable
+						if ( lastSeg->fileoff + lastSeg->filesize != seg->fileoff )
+							return "dyld_sim segments not contiguous";
+						if ( lastSeg->vmaddr + lastSeg->vmsize != seg->vmaddr )
+							return "dyld_sim segments not address contiguous";
+						if ( (seg->initprot & VM_PROT_EXECUTE) != 0 )
+							return "dyld_sim non-first segment is executable";
+					}
+					mappingSize += seg->vmsize;
+					lastSeg = seg;
+				}
+				break;
+			case LC_SEGMENT_COMMAND_WRONG:
+				return "dyld_sim wrong load segment load command";
+			case LC_CODE_SIGNATURE:
+				codeSigCmd = (struct linkedit_data_command*)cmd;
+				break;
+		}
+		cmd = nextCmd;
+	}
+	// last segment must be named __LINKEDIT and not writable
+	if ( lastSeg == NULL )
+		return "dyld_sim has no segments";
+	if ( strcmp(lastSeg->segname, "__LINKEDIT") != 0 )
+		return "dyld_sim last segment not __LINKEDIT";
+	if ( lastSeg->initprot & VM_PROT_WRITE )
+		return "dyld_sim __LINKEDIT segment writable";
+
+	// must have code signature which is contained within LINKEDIT segment
+	if ( codeSigCmd == NULL )
+		return "dyld_sim not code signed";
+	if ( codeSigCmd->dataoff < lastSeg->fileoff )
+		return "dyld_sim code signature not in __LINKEDIT";
+	if ( (codeSigCmd->dataoff + codeSigCmd->datasize) <  codeSigCmd->dataoff )
+		return "dyld_sim code signature size wraps";
+	if ( (codeSigCmd->dataoff + codeSigCmd->datasize) > (lastSeg->fileoff + lastSeg->filesize) )
+		return "dyld_sim code signature extends beyond __LINKEDIT";
+
+	// register code signature with kernel before mmap()ing segments
+	fsignatures_t siginfo;
+	siginfo.fs_file_start=fileOffset;							// start of mach-o slice in fat file
+	siginfo.fs_blob_start=(void*)(long)(codeSigCmd->dataoff);	// start of code-signature in mach-o file
+	siginfo.fs_blob_size=codeSigCmd->datasize;					// size of code-signature
+	int result = fcntl(fd, F_ADDFILESIGS_FOR_DYLD_SIM, &siginfo);
+	if ( result == -1 ) {
+		return mkstringf("dyld_sim fcntl(F_ADDFILESIGS_FOR_DYLD_SIM) failed with errno=%d", errno);
+	}
+	// file range covered by code signature must extend up to code signature itself
+	if ( siginfo.fs_file_start < codeSigCmd->dataoff )
+		return mkstringf("dyld_sim code signature does not cover all of dyld_sim. Signature covers up to 0x%08lX. Signature starts at 0x%08X", (unsigned long)siginfo.fs_file_start, codeSigCmd->dataoff);
+
+	// reserve space, then mmap each segment
+	vm_address_t loadAddress = 0;
+	if ( ::vm_allocate(mach_task_self(), &loadAddress, mappingSize, VM_FLAGS_ANYWHERE) != 0 )
+		return "dyld_sim cannot allocate space";
+	cmd = cmds;
+	struct source_version_command* dyldVersionCmd = NULL;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		switch (cmd->cmd) {
+			case LC_SEGMENT_COMMAND:
+				{
+					struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+					uintptr_t requestedLoadAddress = seg->vmaddr - preferredLoadAddress + loadAddress;
+					void* segAddress = ::mmap((void*)requestedLoadAddress, seg->filesize, seg->initprot, MAP_FIXED | MAP_PRIVATE, fd, fileOffset + seg->fileoff);
+					//dyld::log("dyld_sim %s mapped at %p\n", seg->segname, segAddress);
+					if ( segAddress == (void*)(-1) )
+						return "dyld_sim mmap() of segment failed";
+					if ( ((uintptr_t)segAddress < loadAddress) || ((uintptr_t)segAddress+seg->filesize > loadAddress+mappingSize) )
+						return "dyld_sim mmap() to wrong location";
+				}
+				break;
+			case LC_SOURCE_VERSION:
+				dyldVersionCmd = (struct source_version_command*)cmd;
+				break;
+		}
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+	}
+	close(fd);
+
+	// walk newly mapped dyld_sim __TEXT load commands to find entry point
+	uintptr_t entry = 0;
+	cmd = (struct load_command*)(((char*)loadAddress)+sizeof(macho_header));
+	const uint32_t count = ((macho_header*)(loadAddress))->ncmds;
+	for (uint32_t i = 0; i < count; ++i) {
+		if (cmd->cmd == LC_UNIXTHREAD) {
+		#if __i386__
+			const i386_thread_state_t* registers = (i386_thread_state_t*)(((char*)cmd) + 16);
+			// entry point must be in first segment
+			if ( registers->__eip < firstSeg->vmaddr )
+				return "dyld_sim entry point not in __TEXT segment";
+			if ( registers->__eip > (firstSeg->vmaddr + firstSeg->vmsize) )
+				return "dyld_sim entry point not in __TEXT segment";
+			entry = (registers->__eip + loadAddress - preferredLoadAddress);
+		#elif __x86_64__
+			const x86_thread_state64_t* registers = (x86_thread_state64_t*)(((char*)cmd) + 16);
+			// entry point must be in first segment
+			if ( registers->__rip < firstSeg->vmaddr )
+				return "dyld_sim entry point not in __TEXT segment";
+			if ( registers->__rip > (firstSeg->vmaddr + firstSeg->vmsize) )
+				return "dyld_sim entry point not in __TEXT segment";
+			entry = (registers->__rip + loadAddress - preferredLoadAddress);
+		#endif
+		}
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+	}
+	if ( entry == 0 )
+		return "dyld_sim entry not found";
+
+	// notify debugger that dyld_sim is loaded
+	dyld_image_info info;
+	info.imageLoadAddress = (mach_header*)loadAddress;
+	info.imageFilePath	  = strdup(dyldPath);
+	info.imageFileModDate = sb.st_mtime;
+	addImagesToAllImages(1, &info);
+	dyld::gProcessInfo->notification(dyld_image_adding, 1, &info);
+
+	const char** appleParams = apple;
+	// jump into new simulator dyld
+	typedef uintptr_t (*sim_entry_proc_t)(int argc, const char* argv[], const char* envp[], const char* apple[],
+								const macho_header* mainExecutableMH, const macho_header* dyldMH, uintptr_t dyldSlide,
+								const dyld::SyscallHelpers* vtable, uintptr_t* startGlue);
+	sim_entry_proc_t newDyld = (sim_entry_proc_t)entry;
+	*mainAddr = (*newDyld)(argc, argv, envp, appleParams, mainExecutableMH, (macho_header*)loadAddress,
+					 loadAddress - preferredLoadAddress, 
+					 &sSysCalls, startGlue);
+	return NULL;
+}
+#endif
+
+// 
+// If the DYLD_SKIP_MAIN environment is set to 1, dyld will return the 
+// address of this function instead of main() in the target program which 
+// __dyld_start jumps to. Useful for qualifying dyld itself.
 //
-// _pthread_keys is partitioned in a lower part that dyld will use; libSystem
-// will use the upper part.  We set __pthread_tsd_first to 1 as the start of
-// the lower part.  Libc will take #1 and c++ exceptions will take #2.  There
-// is one free key=3 left.
-//
-extern "C" {
-	extern int __pthread_tsd_first;
-}
- 
+int
+fake_main()
+{
+	return 0;
+}
+
+
+
+
+static bool envVarMatches(const dyld3::closure::LaunchClosure* mainClosure, const char* envp[], const char* varName)
+{
+	__block const char* valueFromClosure = nullptr;
+	mainClosure->forEachEnvVar(^(const char* keyEqualValue, bool& stop) {
+		size_t keyLen = strlen(varName);
+		if ( (strncmp(varName, keyEqualValue, keyLen) == 0) && (keyEqualValue[keyLen] == '=') ) {
+			valueFromClosure = &keyEqualValue[keyLen+1];
+			stop = true;
+		}
+	});
+
+	const char* valueFromEnv = _simple_getenv(envp, varName);
+
+	bool inClosure = (valueFromClosure != nullptr);
+	bool inEnv     = (valueFromEnv != nullptr);
+	if ( inClosure != inEnv )
+		return false;
+	if ( !inClosure && !inEnv )
+		return true;
+	return ( strcmp(valueFromClosure, valueFromEnv) == 0 );
+}
+
+static const char* const sEnvVarsToCheck[] = {
+	"DYLD_LIBRARY_PATH",
+	"DYLD_FRAMEWORK_PATH",
+	"DYLD_FALLBACK_LIBRARY_PATH",
+	"DYLD_FALLBACK_FRAMEWORK_PATH",
+	"DYLD_INSERT_LIBRARIES",
+	"DYLD_IMAGE_SUFFIX",
+	"DYLD_VERSIONED_FRAMEWORK_PATH",
+	"DYLD_VERSIONED_LIBRARY_PATH",
+	"DYLD_ROOT_PATH"
+};
+
+static bool envVarsMatch(const dyld3::closure::LaunchClosure* mainClosure, const char* envp[])
+{
+	for (const char* envVar : sEnvVarsToCheck) {
+		if ( !envVarMatches(mainClosure, envp, envVar) ) {
+			if ( gLinkContext.verboseWarnings )
+				dyld::log("dyld: closure %p not used because %s changed\n", mainClosure, envVar);
+			return false;
+		}
+	}
+
+	// FIXME: dyld3 doesn't support versioned paths so we need to fall back to dyld2 if we have them.
+	// <rdar://problem/37004660> dyld3: support DYLD_VERSIONED_*_PATHs ?
+	if ( sEnv.DYLD_VERSIONED_LIBRARY_PATH != nullptr ) {
+		if ( gLinkContext.verboseWarnings )
+			dyld::log("dyld: closure %p not used because DYLD_VERSIONED_LIBRARY_PATH used\n", mainClosure);
+		return false;
+	}
+	if ( sEnv.DYLD_VERSIONED_FRAMEWORK_PATH != nullptr ) {
+		if ( gLinkContext.verboseWarnings )
+			dyld::log("dyld: closure %p not used because DYLD_VERSIONED_FRAMEWORK_PATH used\n", mainClosure);
+		return false;
+	}
+
+	return true;
+}
+
+static bool closureValid(const dyld3::closure::LaunchClosure* mainClosure, const dyld3::closure::LoadedFileInfo& mainFileInfo,
+						 const uint8_t* mainExecutableCDHash, bool closureInCache, const char* envp[])
+{
+	if ( !closureInCache ) {
+		// verify current dyld cache is same as expected
+		uuid_t expectedCacheUUID;
+		if ( mainClosure->builtAgainstDyldCache(expectedCacheUUID) ) {
+			if ( sSharedCacheLoadInfo.loadAddress == nullptr ) {
+				if ( gLinkContext.verboseWarnings )
+					dyld::log("dyld: closure %p dyld cache not loaded\n", mainClosure);
+				return false;
+			}
+			else {
+				uuid_t actualCacheUUID;
+				sSharedCacheLoadInfo.loadAddress->getUUID(actualCacheUUID);
+				if ( memcmp(expectedCacheUUID, actualCacheUUID, sizeof(uuid_t)) != 0 ) {
+					if ( gLinkContext.verboseWarnings )
+						dyld::log("dyld: closure %p not used because built against different dyld cache\n", mainClosure);
+					return false;
+				}
+			}
+		}
+		else {
+			// closure built assume there is no dyld cache
+			if ( sSharedCacheLoadInfo.loadAddress != nullptr ) {
+				if ( gLinkContext.verboseWarnings )
+					dyld::log("dyld: closure %p built expecting no dyld cache\n", mainClosure);
+				return false;
+			}
+		}
+#if __IPHONE_OS_VERSION_MIN_REQUIRED
+		// verify this closure is not from a previous reboot
+		const char* expectedBootUUID = mainClosure->bootUUID();
+		char actualBootSessionUUID[256] = { 0 };
+		size_t bootSize = sizeof(actualBootSessionUUID);
+		bool gotActualBootUUID = (sysctlbyname("kern.bootsessionuuid", actualBootSessionUUID, &bootSize, NULL, 0) == 0);
+		if ( !gotActualBootUUID || (expectedBootUUID == nullptr) || (strcmp(expectedBootUUID, actualBootSessionUUID) != 0) ) {
+			if ( gLinkContext.verboseWarnings )
+				dyld::log("dyld: closure %p built in different boot context\n", mainClosure);
+			return false;
+		}
+#endif
+	}
+
+	// verify all mach-o files have not changed since closure was built
+	__block bool foundFileThatInvalidatesClosure = false;
+	mainClosure->images()->forEachImage(^(const dyld3::closure::Image* image, bool& stop) {
+		__block uint64_t expectedInode;
+		__block uint64_t expectedMtime;
+		if ( image->hasFileModTimeAndInode(expectedInode, expectedMtime) ) {
+			struct stat statBuf;
+			if ( ::stat(image->path(), &statBuf) == 0 ) {
+				if ( (statBuf.st_mtime != expectedMtime) || (statBuf.st_ino != expectedInode) ) {
+					if ( gLinkContext.verboseWarnings )
+						dyld::log("dyld: closure %p not used because mtime/inode for '%s' has changed since closure was built\n", mainClosure, image->path());
+					foundFileThatInvalidatesClosure = true;
+					stop = true;
+				}
+			}
+			else {
+				if ( gLinkContext.verboseWarnings )
+					dyld::log("dyld: closure %p not used because '%s' is needed by closure but is missing\n", mainClosure, image->path());
+				foundFileThatInvalidatesClosure = true;
+				stop = true;
+			}
+		}
+	});
+	if ( foundFileThatInvalidatesClosure )
+		return false;
+
+	// verify cdHash of main executable is same as recorded in closure
+	uint8_t expectedHash[20];
+	const dyld3::closure::Image* mainImage = mainClosure->images()->imageForNum(mainClosure->topImage());
+	if ( mainImage->hasCdHash(expectedHash) ) {
+		if ( mainExecutableCDHash == nullptr ) {
+			if ( gLinkContext.verboseWarnings )
+				dyld::log("dyld: closure %p not used because main executable is not code signed but was expected to be\n", mainClosure);
+            return false;
+		}
+		if ( memcmp(mainExecutableCDHash, expectedHash, 20) != 0 ) {
+			if ( gLinkContext.verboseWarnings )
+				dyld::log("dyld: closure %p not used because main executable cd-hash changed since closure was built\n", mainClosure);
+            return false;
+		}
+	}
+	
+	// verify UUID of main executable is same as recorded in closure
+	uuid_t expectedUUID;
+	bool hasExpect = mainImage->getUuid(expectedUUID);
+	uuid_t actualUUID;
+	const dyld3::MachOLoaded* mainExecutableMH = (const dyld3::MachOLoaded*)mainFileInfo.fileContent;
+	bool hasActual = mainExecutableMH->getUuid(actualUUID);
+	if ( hasExpect != hasActual ) {
+		if ( gLinkContext.verboseWarnings )
+			dyld::log("dyld: closure %p not used because UUID of executable changed since closure was built\n", mainClosure);
+		return false;
+	}
+	if ( hasExpect && hasActual && memcmp(actualUUID, expectedUUID, sizeof(uuid_t)) != 0 ) {
+		if ( gLinkContext.verboseWarnings )
+			dyld::log("dyld: closure %p not used because UUID of executable changed since closure was built\n", mainClosure);
+		return false;
+	}
+
+	// verify DYLD_* env vars are same as when closure was built
+	if ( !envVarsMatch(mainClosure, envp) ) {
+		return false;
+	}
+
+	// verify files that are supposed to be missing actually are missing
+	mainClosure->forEachMustBeMissingFile(^(const char* path, bool& stop) {
+		struct stat statBuf;
+		if ( ::stat(path, &statBuf) == 0 ) {
+			stop = true;
+			foundFileThatInvalidatesClosure = true;
+			if ( gLinkContext.verboseWarnings )
+				dyld::log("dyld: closure %p not used because found unexpected file '%s'\n", mainClosure, path);
+		}
+	});
+
+	// verify closure did not require anything unavailable
+	if ( mainClosure->usedAtPaths() && !gLinkContext.allowAtPaths ) {
+		if ( gLinkContext.verboseWarnings )
+			dyld::log("dyld: closure %p not used because is used @paths, but process does not allow that\n", mainClosure);
+		return false;
+	}
+	if ( mainClosure->usedFallbackPaths() && !gLinkContext.allowClassicFallbackPaths ) {
+		if ( gLinkContext.verboseWarnings )
+			dyld::log("dyld: closure %p not used because is used default fallback paths, but process does not allow that\n", mainClosure);
+		return false;
+	}
+
+	return !foundFileThatInvalidatesClosure;
+}
+
+static bool nolog(const char* format, ...)
+{
+	return false;
+}
+
+static bool dolog(const char* format, ...)
+{
+	va_list	list;
+	va_start(list, format);
+	vlog(format, list);
+	va_end(list);
+	return true;
+}
+
+static bool launchWithClosure(const dyld3::closure::LaunchClosure* mainClosure,
+							  const DyldSharedCache* dyldCache,
+							  const dyld3::MachOLoaded* mainExecutableMH, uintptr_t mainExecutableSlide,
+							  int argc, const char* argv[], const char* envp[], const char* apple[],
+							  uintptr_t* entry, uintptr_t* startGlue)
+{
+	// build list of all known ImageArrays (at most three: cached dylibs, other OS dylibs, and main prog)
+	STACK_ALLOC_ARRAY(const dyld3::closure::ImageArray*, imagesArrays, 3);
+	const dyld3::closure::ImageArray* mainClosureImages = mainClosure->images();
+	if ( dyldCache != nullptr ) {
+		imagesArrays.push_back(dyldCache->cachedDylibsImageArray());
+		if ( auto others = dyldCache->otherOSImageArray() )
+			imagesArrays.push_back(others);
+	}
+	imagesArrays.push_back(mainClosureImages);
+
+	// allocate space for Array<LoadedImage>
+	STACK_ALLOC_ARRAY(dyld3::LoadedImage, allImages, mainClosure->initialLoadCount());
+
+	__block dyld3::Loader loader(allImages, dyldCache, imagesArrays,  (gLinkContext.verboseLoading ? &dolog : &nolog),
+																	  (gLinkContext.verboseMapping ? &dolog : &nolog),
+																	  (gLinkContext.verboseBind    ? &dolog : &nolog),
+																	  (gLinkContext.verboseDOF     ? &dolog : &nolog));
+	dyld3::closure::ImageNum mainImageNum = mainClosure->topImage();
+	mainClosureImages->forEachImage(^(const dyld3::closure::Image* image, bool& stop) {
+		if ( image->imageNum() == mainImageNum ) {
+			// add main executable (which is already mapped by kernel) to list
+			dyld3::LoadedImage mainLoadedImage = dyld3::LoadedImage::make(image, mainExecutableMH);
+			mainLoadedImage.setState(dyld3::LoadedImage::State::mapped);
+			mainLoadedImage.markLeaveMapped();
+			loader.addImage(mainLoadedImage);
+			stop = true;
+		}
+		else {
+			// add inserted library to initial list
+			loader.addImage(dyld3::LoadedImage::make(image));
+		}
+	});
+
+	// recursively load all dependents and fill in allImages array
+	Diagnostics diag;
+	loader.completeAllDependents(diag);
+	if ( diag.noError() )
+		loader.mapAndFixupAllImages(diag, dyld3::Loader::dtraceUserProbesEnabled());
+	if ( diag.hasError() ) {
+		if ( gLinkContext.verboseWarnings )
+			dyld::log("dyld: %s\n", diag.errorMessage());
+		return false;
+	}
+
+	//dyld::log("loaded image list:\n");
+	//for (const dyld3::LoadedImage& info : allImages) {
+	//	dyld::log("mh=%p, path=%s\n", info.loadedAddress(), info.image()->path());
+	//}
+
+	// find libdyld entry
+	dyld3::closure::Image::ResolvedSymbolTarget dyldEntry;
+	mainClosure->libDyldEntry(dyldEntry);
+	const dyld3::LibDyldEntryVector* libDyldEntry = (dyld3::LibDyldEntryVector*)loader.resolveTarget(dyldEntry);
+
+	// send info on all images to libdyld.dylb
+	libDyldEntry->setVars(mainExecutableMH, argc, argv, envp, apple);
+	if ( libDyldEntry->vectorVersion > 4 )
+		libDyldEntry->setRestrictions(gLinkContext.allowAtPaths, gLinkContext.allowEnvVarsPath);
+	libDyldEntry->setHaltFunction(&halt);
+	if ( libDyldEntry->vectorVersion > 5 ) {
+		libDyldEntry->setNotifyMonitoringDyldMain(&notifyMonitoringDyldMain);
+		libDyldEntry->setNotifyMonitoringDyld(&notifyMonitoringDyld);
+	}
+	if ( libDyldEntry->vectorVersion > 2 )
+		libDyldEntry->setChildForkFunction(&_dyld_fork_child);
+#if !TARGET_IPHONE_SIMULATOR
+	if ( libDyldEntry->vectorVersion > 3 )
+		libDyldEntry->setLogFunction(&dyld::vlog);
+#endif
+	libDyldEntry->setOldAllImageInfo(gProcessInfo);
+	const dyld3::LoadedImage* libSys = loader.findImage(mainClosure->libSystemImageNum());
+	libDyldEntry->setInitialImageList(mainClosure, dyldCache, sSharedCacheLoadInfo.path, allImages, *libSys);
+	// run initializers
+	CRSetCrashLogMessage("dyld3: launch, running initializers");
+	libDyldEntry->runInitialzersBottomUp((mach_header*)mainExecutableMH);
+	//dyld::log("returned from runInitialzersBottomUp()\n");
+
+	if (dyld3::kdebug_trace_dyld_enabled(DBG_DYLD_TIMING_LAUNCH_EXECUTABLE)) {
+		dyld3::kdebug_trace_dyld_duration_end(launchTraceID, DBG_DYLD_TIMING_LAUNCH_EXECUTABLE, 0, 0, 3);
+	}
+	dyld3::closure::Image::ResolvedSymbolTarget progEntry;
+	if ( mainClosure->mainEntry(progEntry) ) {
+		// modern app with LC_MAIN
+		// set startGlue to "start" function in libdyld.dylib
+		// set entry to "main" function in program
+		*startGlue = (uintptr_t)(libDyldEntry->startFunc);
+		*entry     = loader.resolveTarget(progEntry);
+	}
+	else if ( mainClosure->startEntry(progEntry) ) {
+		// old style app linked with crt1.o
+		// entry is "start" function in program
+		*startGlue = 0;
+		*entry     = loader.resolveTarget(progEntry);
+	}
+	else {
+		assert(0);
+	}
+
+	CRSetCrashLogMessage("dyld3 mode");
+	return true;
+}
+
+
+#if !TARGET_IPHONE_SIMULATOR
+
+static void putHexNibble(uint8_t value, char*& p)
+{
+	if ( value < 10 )
+		*p++ = '0' + value;
+	else
+		*p++ = 'A' + value - 10;
+}
+
+static void putHexByte(uint8_t value, char*& p)
+{
+	value &= 0xFF;
+	putHexNibble(value >> 4,   p);
+	putHexNibble(value & 0x0F, p);
+}
+
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+static void makeHashOfProgramAndEnv(const char* mainExecutablePath, const uint8_t* mainExecutableCDHash, const char* envp[], uint8_t hash32[32])
+{
+	// create hash of main path, main cd hash, cache UUID, DYLD_* env vars
+	const struct ccdigest_info* di = ccsha256_di();
+	ccdigest_di_decl(di, hashTemp); // defines hashTemp array in stack
+	ccdigest_init(di, hashTemp);
+	// hash in main executable path
+	ccdigest_update(di, hashTemp, strlen(mainExecutablePath), mainExecutablePath);
+	// hash in cdHash of main executable
+	if ( mainExecutableCDHash != nullptr )
+		ccdigest_update(di, hashTemp, 20, mainExecutableCDHash);
+	// hash in shared cache UUID
+	if ( sSharedCacheLoadInfo.loadAddress != nullptr ) {
+		uuid_t cacheUUID;
+		sSharedCacheLoadInfo.loadAddress->getUUID(cacheUUID);
+		ccdigest_update(di, hashTemp, sizeof(uuid_t), cacheUUID);
+	}
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+	// hash in if process is restricted
+	ccdigest_update(di, hashTemp, sizeof(gLinkContext.allowEnvVarsPath), &gLinkContext.allowEnvVarsPath);
+#endif
+	// include dyld's UUID so changing dyld invalidates closures
+	uuid_t dyldUUID;
+	if ( ((const dyld3::MachOLoaded*)&__dso_handle)->getUuid(dyldUUID) )
+		ccdigest_update(di, hashTemp, sizeof(uuid_t), dyldUUID);
+
+	// hash in DYLD_* env vars
+	for (const char* envVar : sEnvVarsToCheck) {
+		if ( const char* keyValue = _simple_getenv(envp, envVar) )
+			ccdigest_update(di, hashTemp, strlen(keyValue), keyValue);
+	}
+	// finish SHA256 into 32-byte value
+	ccdigest_final(di, hashTemp, hash32);
+	ccdigest_di_clear(di, hashTemp);
+}
+#endif
+
+static void buildClosureCachePath(const char* mainExecutablePath,const dyld3::MachOLoaded* mainExecutableMH,
+								  const uint8_t* mainExecutableCDHash, const char* envp[], char closurePath[])
+{
+	// build base path of $TMPDIR/dyld/<prog-name>-
+	const char* tempDir = _simple_getenv(envp, "TMPDIR");
+	if ( tempDir == nullptr )
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+		tempDir = "/private/tmp/";
+#else
+		tempDir = "/private/var/tmp/";
+#endif
+	strlcpy(closurePath, tempDir, PATH_MAX);
+	strlcat(closurePath, "/com.apple.dyld/", PATH_MAX);
+
+	// make sure dyld sub-dir exists
+	struct stat statbuf;
+	if ( ::stat(closurePath, &statbuf) != 0 ) {
+		::mkdir(closurePath, S_IRWXU);
+	}
+
+	const char* leafName = strrchr(mainExecutablePath, '/');
+	if ( leafName == nullptr )
+		leafName = mainExecutablePath;
+	else
+		++leafName;
+	strlcat(closurePath, leafName, PATH_MAX);
+
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+	// on macOS we allow multiple closures by hashing the env vars into the cache filename
+	strlcat(closurePath, "-", PATH_MAX);
+	uint8_t hash32[32];
+	makeHashOfProgramAndEnv(mainExecutablePath, mainExecutableCDHash, envp, hash32);
+	char hashString[72];
+	char* s = hashString;
+	for (int i=0; i < 32; ++i)
+		putHexByte(hash32[i], s);
+	*s = '\0';
+	strlcat(closurePath, hashString, PATH_MAX);
+#else
+	// on iOS, the file name is the leaf name and UUID
+	uuid_t mainExeUUID;
+	if ( mainExecutableMH->getUuid(mainExeUUID) ) {
+		char mainUuidStr[40];
+		bytesToHex(mainExeUUID, sizeof(uuid_t), mainUuidStr);
+		strlcat(closurePath, "-", PATH_MAX);
+		strlcat(closurePath, mainUuidStr, PATH_MAX);
+	}
+#endif
+	strlcat(closurePath, ".closure", PATH_MAX);
+}
+
+static const dyld3::closure::LaunchClosure* mapClosureFile(const char* closurePath)
+{
+	struct stat statbuf;
+	if ( ::stat(closurePath, &statbuf) == -1 )
+		return nullptr;
+
+	int fd = ::open(closurePath, O_RDONLY);
+	if ( fd < 0 )
+		return nullptr;
+
+	const dyld3::closure::LaunchClosure* closure = (dyld3::closure::LaunchClosure*)::mmap(NULL, (size_t)statbuf.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	::close(fd);
+
+	if ( closure == MAP_FAILED )
+		return nullptr;
+
+	return closure;
+}
+
+static const dyld3::closure::LaunchClosure* buildLaunchClosure(const uint8_t* mainExecutableCDHash,
+															   const dyld3::closure::LoadedFileInfo& mainFileInfo, const char* envp[])
+{
+	const dyld3::MachOLoaded* mainExecutableMH = (const dyld3::MachOLoaded*)mainFileInfo.fileContent;
+	dyld3::closure::PathOverrides pathOverrides;
+	pathOverrides.setFallbackPathHandling(gLinkContext.allowClassicFallbackPaths ? dyld3::closure::PathOverrides::FallbackPathMode::classic : dyld3::closure::PathOverrides::FallbackPathMode::restricted);
+	pathOverrides.setEnvVars(envp, mainExecutableMH, mainFileInfo.path);
+	STACK_ALLOC_ARRAY(const dyld3::closure::ImageArray*,  imagesArrays, 3);
+	if ( sSharedCacheLoadInfo.loadAddress != nullptr ) {
+		imagesArrays.push_back(sSharedCacheLoadInfo.loadAddress->cachedDylibsImageArray());
+		if ( auto others = sSharedCacheLoadInfo.loadAddress->otherOSImageArray() )
+			imagesArrays.push_back(others);
+	}
+
+	dyld3::closure::ClosureBuilder::LaunchErrorInfo* errorInfo = (dyld3::closure::ClosureBuilder::LaunchErrorInfo*)&gProcessInfo->errorKind;
+	dyld3::closure::FileSystemPhysical fileSystem;
+	dyld3::closure::ClosureBuilder::AtPath atPathHanding = (gLinkContext.allowAtPaths ? dyld3::closure::ClosureBuilder::AtPath::all : dyld3::closure::ClosureBuilder::AtPath::none);
+	dyld3::closure::ClosureBuilder builder(dyld3::closure::kFirstLaunchClosureImageNum, fileSystem, sSharedCacheLoadInfo.loadAddress, true, pathOverrides, atPathHanding, errorInfo, mainExecutableMH->archName());
+	const dyld3::closure::LaunchClosure* result = builder.makeLaunchClosure(mainFileInfo, gLinkContext.allowInsertFailures);
+	if ( builder.diagnostics().hasError() )
+		halt(builder.diagnostics().errorMessage());
+
+	if ( result == nullptr )
+		return nullptr;
+
+	if ( !closureValid(result, mainFileInfo, mainExecutableCDHash, false, envp) ) {
+		// some how the freshly generated closure is invalid...
+		if ( gLinkContext.verboseWarnings )
+			dyld::log("dyld: somehow just built closure is invalid\n");
+		return nullptr;
+	}
+	// try to save closure to disk for next launch (atomically)
+	char closurePath[PATH_MAX];
+	buildClosureCachePath(mainFileInfo.path, mainExecutableMH, mainExecutableCDHash, envp, closurePath);
+	char closurePathTemp[PATH_MAX];
+	strlcpy(closurePathTemp, closurePath, PATH_MAX);
+	int mypid = getpid();
+	char pidBuf[16];
+	char* s = pidBuf;
+	*s++ = '.';
+	putHexByte(mypid >> 24, s);
+	putHexByte(mypid >> 16, s);
+	putHexByte(mypid >> 8, s);
+	putHexByte(mypid, s);
+	*s = '\0';
+	strlcat(closurePathTemp, pidBuf, PATH_MAX);
+	int fd = ::open(closurePathTemp, O_WRONLY|O_CREAT, S_IRUSR|S_IWUSR);
+	if ( fd != -1 ) {
+		::ftruncate(fd, result->size());
+		::write(fd, result, result->size());
+		::fchmod(fd, S_IRUSR);
+		::close(fd);
+		::rename(closurePathTemp, closurePath);
+		// free built closure and mmap file() to reduce dirty memory
+		result->deallocate();
+		result = mapClosureFile(closurePath);
+	}
+	else if ( gLinkContext.verboseWarnings ) {
+		dyld::log("could not save closure (errno=%d) to: %s\n", errno, closurePathTemp);
+	}
+	
+	if ( gLinkContext.verboseWarnings )
+		dyld::log("dyld: just built closure %p (size=%lu) for %s\n", result, result->size(), sExecPath);
+
+	return result;
+}
+
+static const dyld3::closure::LaunchClosure* findCachedLaunchClosure(const uint8_t* mainExecutableCDHash,
+																    const dyld3::closure::LoadedFileInfo& mainFileInfo,
+																	const char* envp[])
+{
+	char closurePath[PATH_MAX];
+	buildClosureCachePath(mainFileInfo.path, (const dyld3::MachOLoaded*)mainFileInfo.fileContent, mainExecutableCDHash, envp, closurePath);
+	const dyld3::closure::LaunchClosure* closure = mapClosureFile(closurePath);
+	if ( closure == nullptr )
+		return nullptr;
+
+	if ( !closureValid(closure, mainFileInfo, mainExecutableCDHash, false, envp) ) {
+		::munmap((void*)closure, closure->size());
+		return nullptr;
+	}
+
+	if ( gLinkContext.verboseWarnings )
+		dyld::log("dyld: used cached closure %p (size=%lu) for %s\n", closure, closure->size(), sExecPath);
+
+	return closure;
+}
+
+#endif // !TARGET_IPHONE_SIMULATOR
+
+
+
+#if !__MAC_OS_X_VERSION_MIN_REQUIRED
+static const char* sWhiteListDirs[] = {
+	"/bin/",
+	"/sbin/",
+	"/usr/bin/"
+};
+#endif
+
+static bool inWhiteList(const char* execPath)
+{
+    // First test to see if we forced in dyld2 via a kernel boot-arg
+    if ( dyld3::bootArgsContains("force_dyld2=1") )
+		return false;
+
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+
+	// rdar://problem/32701418: Don't use dyld3 for i386 for now.
+#if __i386__
+	return false;
+#else
+
+
+	return true;
+#endif // #if __i386__
+
+#else
+
+
+	// <rdar://problem/33171968> enable dyld3 mode for all OS programs when using customer dyld cache (no roots)
+	if ( (sSharedCacheLoadInfo.loadAddress != nullptr) && (sSharedCacheLoadInfo.loadAddress->header.cacheType == kDyldSharedCacheTypeProduction) )
+		return true;
+
+	return dyld3::bootArgsContains("force_dyld3=1");
+#endif
+}
+
+#if !TARGET_IPHONE_SIMULATOR
+static bool isStagedApp(const dyld3::MachOFile* mainExecutableMH, const char* mainExecutablePath)
+{
+#if !__MAC_OS_X_VERSION_MIN_REQUIRED
+	if ( (strncmp(mainExecutablePath, "/var/containers/Bundle/Application/", 35) == 0)
+	  || (strncmp(mainExecutablePath, "/private/var/containers/Bundle/Application/", 43) == 0) ) {
+		// staged apps are built without LC_ENCRYPTION_INFO
+		if ( !mainExecutableMH->canBeFairPlayEncrypted() )
+			return true;
+	}
+#endif
+	return false;
+}
+#endif
 
 //
 // Entry point for dyld.  The kernel loads dyld and jumps to __dyld_start which
@@ -1975,18 +5884,58 @@
 // Returns address of main() in target program which __dyld_start jumps to
 //
 uintptr_t
-_main(const struct mach_header* mainExecutableMH, int argc, const char* argv[], const char* envp[], const char* apple[])
-{	
-	// set pthread keys to dyld range
-	__pthread_tsd_first = 1;
+_main(const macho_header* mainExecutableMH, uintptr_t mainExecutableSlide, 
+		int argc, const char* argv[], const char* envp[], const char* apple[], 
+		uintptr_t* startGlue)
+{
+	if (dyld3::kdebug_trace_dyld_enabled(DBG_DYLD_TIMING_LAUNCH_EXECUTABLE)) {
+		launchTraceID = dyld3::kdebug_trace_dyld_duration_start(DBG_DYLD_TIMING_LAUNCH_EXECUTABLE, (uint64_t)mainExecutableMH, 0, 0);
+	}
+
+    // Grab the cdHash of the main executable from the environment
+	uint8_t mainExecutableCDHashBuffer[20];
+	const uint8_t* mainExecutableCDHash = nullptr;
+	if ( hexToBytes(_simple_getenv(apple, "executable_cdhash"), 40, mainExecutableCDHashBuffer) )
+		mainExecutableCDHash = mainExecutableCDHashBuffer;
+
+	// Trace dyld's load
+	notifyKernelAboutImage((macho_header*)&__dso_handle, _simple_getenv(apple, "dyld_file"));
+#if !TARGET_IPHONE_SIMULATOR
+	// Trace the main executable's load
+	notifyKernelAboutImage(mainExecutableMH, _simple_getenv(apple, "executable_file"));
+#endif
+
+	uintptr_t result = 0;
+	sMainExecutableMachHeader = mainExecutableMH;
+	sMainExecutableSlide = mainExecutableSlide;
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+	// if this is host dyld, check to see if iOS simulator is being run
+	const char* rootPath = _simple_getenv(envp, "DYLD_ROOT_PATH");
+	if ( (rootPath != NULL) ) {
+		// look to see if simulator has its own dyld
+		char simDyldPath[PATH_MAX]; 
+		strlcpy(simDyldPath, rootPath, PATH_MAX);
+		strlcat(simDyldPath, "/usr/lib/dyld_sim", PATH_MAX);
+		int fd = my_open(simDyldPath, O_RDONLY, 0);
+		if ( fd != -1 ) {
+			const char* errMessage = useSimulatorDyld(fd, mainExecutableMH, simDyldPath, argc, argv, envp, apple, startGlue, &result);
+			if ( errMessage != NULL )
+				halt(errMessage);
+			return result;
+		}
+	}
+#endif
+
+	CRSetCrashLogMessage("dyld: launch started");
+
+	setContext(mainExecutableMH, argc, argv, envp, apple);
+
+	// Pickup the pointer to the exec path.
+	sExecPath = _simple_getenv(apple, "executable_path");
+
+	// <rdar://problem/13868260> Remove interim apple[0] transition code from dyld
+	if (!sExecPath) sExecPath = apple[0];
 	
-	bool isEmulated = checkEmulation();
-	// Pickup the pointer to the exec path.
-	sExecPath = apple[0];
-	if (isEmulated) {
-		// under Rosetta 
-		sExecPath = strdup(apple[0] + strlen(apple[0]) + 1);
-	}
 	if ( sExecPath[0] != '/' ) {
 		// have relative path, use cwd to make absolute
 		char cwdbuff[MAXPATHLEN];
@@ -1999,89 +5948,424 @@
 			sExecPath = s;
 		}
 	}
-	uintptr_t result = 0;
-	sMainExecutableMachHeader = mainExecutableMH;
-	checkEnvironmentVariables(envp, isEmulated);
-	if ( sEnv.DYLD_PRINT_OPTS ) 
+
+	// Remember short name of process for later logging
+	sExecShortName = ::strrchr(sExecPath, '/');
+	if ( sExecShortName != NULL )
+		++sExecShortName;
+	else
+		sExecShortName = sExecPath;
+
+    configureProcessRestrictions(mainExecutableMH);
+
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+    if ( !gLinkContext.allowEnvVarsPrint && !gLinkContext.allowEnvVarsPath && !gLinkContext.allowEnvVarsSharedCache ) {
+		pruneEnvironmentVariables(envp, &apple);
+		// set again because envp and apple may have changed or moved
+		setContext(mainExecutableMH, argc, argv, envp, apple);
+	}
+	else
+#endif
+	{
+		checkEnvironmentVariables(envp);
+		defaultUninitializedFallbackPaths(envp);
+	}
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+	if (  ((dyld3::MachOFile*)mainExecutableMH)->supportsPlatform(dyld3::Platform::iOSMac)
+	  && !((dyld3::MachOFile*)mainExecutableMH)->supportsPlatform(dyld3::Platform::macOS)) {
+		gLinkContext.rootPaths = parseColonList("/System/iOSSupport", NULL);
+		gLinkContext.marzipan = true;
+		if ( sEnv.DYLD_FALLBACK_LIBRARY_PATH == sLibraryFallbackPaths )
+			sEnv.DYLD_FALLBACK_LIBRARY_PATH = sRestrictedLibraryFallbackPaths;
+		if ( sEnv.DYLD_FALLBACK_FRAMEWORK_PATH == sFrameworkFallbackPaths )
+			sEnv.DYLD_FALLBACK_FRAMEWORK_PATH = sRestrictedFrameworkFallbackPaths;
+	}
+#endif
+	if ( sEnv.DYLD_PRINT_OPTS )
 		printOptions(argv);
 	if ( sEnv.DYLD_PRINT_ENV ) 
 		printEnvironmentVariables(envp);
-	getHostInfo();
-	setContext(argc, argv, envp, apple);
-	ImageLoader::BindingLaziness bindness = sEnv.DYLD_BIND_AT_LAUNCH ? ImageLoader::kLazyAndNonLazy : ImageLoader::kNonLazyOnly;
-	
-	// load any inserted libraries before loading the main executable so that they are first in flat namespace
-	int insertLibrariesCount = 0;
-	if ( sEnv.DYLD_INSERT_LIBRARIES != NULL ) {
-		for (const char* const* lib = sEnv.DYLD_INSERT_LIBRARIES; *lib != NULL; ++lib) {
-			insertLibrariesCount++;
-		}
-	}
-	ImageLoader* insertedImages[insertLibrariesCount];
-	if ( insertLibrariesCount > 0 ) {
-		for (int i=0; i < insertLibrariesCount; ++i) {
-			try {
-				LoadContext context;
-				context.useSearchPaths		= false;
-				context.useLdLibraryPath	= false;
-				context.dontLoad			= false;
-				context.mustBeBundle		= false;
-				context.mustBeDylib			= true;
-				context.matchByInstallName	= false;
-				context.origin				= NULL;	// can't use @loader_path with DYLD_INSERT_LIBRARIES
-				context.rpath				= NULL;
-				insertedImages[i] = load(sEnv.DYLD_INSERT_LIBRARIES[i], context);
-			}
-			catch (...) {
-				char buf[strlen(sEnv.DYLD_INSERT_LIBRARIES[i])+50];
-				sprintf(buf, "could not load inserted library: %s\n", sEnv.DYLD_INSERT_LIBRARIES[i]);
-				insertedImages[i]  = NULL;
-				halt(buf);
-			}
-		}
-	}
-	
-	// load and link main executable
+	getHostInfo(mainExecutableMH, mainExecutableSlide);
+
+	// load shared cache
+	checkSharedRegionDisable((dyld3::MachOLoaded*)mainExecutableMH, mainExecutableSlide);
+#if TARGET_IPHONE_SIMULATOR
+	// <HACK> until <rdar://30773711> is fixed
+	gLinkContext.sharedRegionMode = ImageLoader::kUsePrivateSharedRegion;
+	// </HACK>
+#endif
+	if ( gLinkContext.sharedRegionMode != ImageLoader::kDontUseSharedRegion ) {
+		mapSharedCache();
+	}
+	bool cacheCompatible = (sSharedCacheLoadInfo.loadAddress == nullptr) || (sSharedCacheLoadInfo.loadAddress->header.formatVersion == dyld3::closure::kFormatVersion);
+	if ( cacheCompatible && (sEnableClosures || inWhiteList(sExecPath)) ) {
+		const dyld3::closure::LaunchClosure* mainClosure = nullptr;
+		dyld3::closure::LoadedFileInfo mainFileInfo;
+		mainFileInfo.fileContent = mainExecutableMH;
+		mainFileInfo.path = sExecPath;
+		// FIXME: If we are saving this closure, this slice offset/length is probably wrong in the case of FAT files.
+		mainFileInfo.sliceOffset = 0;
+		mainFileInfo.sliceLen = std::numeric_limits<__typeof(mainFileInfo.sliceLen)>::max();
+		struct stat mainExeStatBuf;
+		if ( ::stat(sExecPath, &mainExeStatBuf) == 0 ) {
+			mainFileInfo.inode = mainExeStatBuf.st_ino;
+			mainFileInfo.mtime = mainExeStatBuf.st_mtime;
+		}
+		// check for closure in cache first
+		if ( sSharedCacheLoadInfo.loadAddress != nullptr ) {
+			mainClosure = sSharedCacheLoadInfo.loadAddress->findClosure(sExecPath);
+			if ( gLinkContext.verboseWarnings && (mainClosure != nullptr) )
+				dyld::log("dyld: found closure %p (size=%lu) in dyld shared cache\n", mainClosure, mainClosure->size());
+		}
+	#if !TARGET_IPHONE_SIMULATOR
+		if ( (mainClosure == nullptr) || !closureValid(mainClosure, mainFileInfo, mainExecutableCDHash, true, envp) ) {
+			mainClosure = nullptr;
+			if ( sEnableClosures || isStagedApp((dyld3::MachOFile*)mainExecutableMH, sExecPath) ) {
+				// if forcing closures, and no closure in cache, or it is invalid, check for cached closure
+				mainClosure = findCachedLaunchClosure(mainExecutableCDHash, mainFileInfo, envp);
+				if ( mainClosure == nullptr ) {
+					// if  no cached closure found, build new one
+					mainClosure = buildLaunchClosure(mainExecutableCDHash, mainFileInfo, envp);
+				}
+			}
+		}
+	#endif
+		// try using launch closure
+		if ( mainClosure != nullptr ) {
+			CRSetCrashLogMessage("dyld3: launch started");
+			bool launched = launchWithClosure(mainClosure, sSharedCacheLoadInfo.loadAddress, (dyld3::MachOLoaded*)mainExecutableMH,
+											  mainExecutableSlide, argc, argv, envp, apple, &result, startGlue);
+	#if !TARGET_IPHONE_SIMULATOR
+			if ( !launched ) {
+				// closure is out of date, build new one
+				mainClosure = buildLaunchClosure(mainExecutableCDHash, mainFileInfo, envp);
+				if ( mainClosure != nullptr ) {
+					launched = launchWithClosure(mainClosure, sSharedCacheLoadInfo.loadAddress, (dyld3::MachOLoaded*)mainExecutableMH,
+												 mainExecutableSlide, argc, argv, envp, apple, &result, startGlue);
+				}
+			}
+	#endif
+			if ( launched ) {
+#if __has_feature(ptrauth_calls)
+				// start() calls the result pointer as a function pointer so we need to sign it.
+				result = (uintptr_t)__builtin_ptrauth_sign_unauthenticated((void*)result, 0, 0);
+#endif
+				if (sSkipMain)
+					result = (uintptr_t)&fake_main;
+				return result;
+			}
+			else {
+				if ( gLinkContext.verboseWarnings )
+					dyld::log("dyld: unable to use closure %p\n", mainClosure);
+			}
+		}
+	}
+	else {
+		if ( gLinkContext.verboseWarnings )
+			dyld::log("dyld: not using closure because shared cache format version does not match dyld's\n");
+	}
+	// could not use closure info, launch old way
+
+
+
+	// install gdb notifier
+	stateToHandlers(dyld_image_state_dependents_mapped, sBatchHandlers)->push_back(notifyGDB);
+	stateToHandlers(dyld_image_state_mapped, sSingleHandlers)->push_back(updateAllImages);
+	// make initial allocations large enough that it is unlikely to need to be re-alloced
+	sImageRoots.reserve(16);
+	sAddImageCallbacks.reserve(4);
+	sRemoveImageCallbacks.reserve(4);
+	sAddLoadImageCallbacks.reserve(4);
+	sImageFilesNeedingTermination.reserve(16);
+	sImageFilesNeedingDOFUnregistration.reserve(8);
+
+#if !TARGET_IPHONE_SIMULATOR
+#ifdef WAIT_FOR_SYSTEM_ORDER_HANDSHAKE
+	// <rdar://problem/6849505> Add gating mechanism to dyld support system order file generation process
+	WAIT_FOR_SYSTEM_ORDER_HANDSHAKE(dyld::gProcessInfo->systemOrderFlag);
+#endif
+#endif
+
+
 	try {
-		sMainExecutable = instantiateFromLoadedImage(mainExecutableMH, sExecPath);
+		// add dyld itself to UUID list
+		addDyldImageToUUIDList();
+
+#if SUPPORT_ACCELERATE_TABLES
+#if __arm64e__
+		// Disable accelerator tables when we have threaded rebase/bind, which is arm64e executables only for now.
+		if (sMainExecutableMachHeader->cpusubtype == CPU_SUBTYPE_ARM64_E)
+			sDisableAcceleratorTables = true;
+#endif
+		bool mainExcutableAlreadyRebased = false;
+		if ( (sSharedCacheLoadInfo.loadAddress != nullptr) && !dylibsCanOverrideCache() && !sDisableAcceleratorTables && (sSharedCacheLoadInfo.loadAddress->header.accelerateInfoAddr != 0) ) {
+			struct stat statBuf;
+			if ( ::stat(IPHONE_DYLD_SHARED_CACHE_DIR "no-dyld2-accelerator-tables", &statBuf) != 0 )
+				sAllCacheImagesProxy = ImageLoaderMegaDylib::makeImageLoaderMegaDylib(&sSharedCacheLoadInfo.loadAddress->header, sSharedCacheLoadInfo.slide, mainExecutableMH, gLinkContext);
+		}
+
+reloadAllImages:
+#endif
+
+		CRSetCrashLogMessage(sLoadingCrashMessage);
+		// instantiate ImageLoader for main executable
+		sMainExecutable = instantiateFromLoadedImage(mainExecutableMH, mainExecutableSlide, sExecPath);
 		gLinkContext.mainExecutable = sMainExecutable;
+		gLinkContext.mainExecutableCodeSigned = hasCodeSignatureLoadCommand(mainExecutableMH);
+
+#if TARGET_IPHONE_SIMULATOR
+		// check main executable is not too new for this OS
+		{
+			if ( ! isSimulatorBinary((uint8_t*)mainExecutableMH, sExecPath) ) {
+				throwf("program was built for a platform that is not supported by this runtime");
+			}
+			uint32_t mainMinOS = sMainExecutable->minOSVersion();
+
+			// dyld is always built for the current OS, so we can get the current OS version
+			// from the load command in dyld itself.
+			uint32_t dyldMinOS = ImageLoaderMachO::minOSVersion((const mach_header*)&__dso_handle);
+			if ( mainMinOS > dyldMinOS ) {
+	#if TARGET_OS_WATCH
+				throwf("app was built for watchOS %d.%d which is newer than this simulator %d.%d",
+						mainMinOS >> 16, ((mainMinOS >> 8) & 0xFF),
+						dyldMinOS >> 16, ((dyldMinOS >> 8) & 0xFF));
+	#elif TARGET_OS_TV
+				throwf("app was built for tvOS %d.%d which is newer than this simulator %d.%d",
+						mainMinOS >> 16, ((mainMinOS >> 8) & 0xFF),
+						dyldMinOS >> 16, ((dyldMinOS >> 8) & 0xFF));
+	#else
+				throwf("app was built for iOS %d.%d which is newer than this simulator %d.%d",
+						mainMinOS >> 16, ((mainMinOS >> 8) & 0xFF),
+						dyldMinOS >> 16, ((dyldMinOS >> 8) & 0xFF));
+	#endif
+			}
+		}
+#endif
+
+
+	#if __MAC_OS_X_VERSION_MIN_REQUIRED
+		// <rdar://problem/22805519> be less strict about old mach-o binaries
+		uint32_t mainSDK = sMainExecutable->sdkVersion();
+		gLinkContext.strictMachORequired = (mainSDK >= DYLD_MACOSX_VERSION_10_12) || gLinkContext.allowInsertFailures;
+	#else
+		// simulators, iOS, tvOS, and watchOS are always strict
+		gLinkContext.strictMachORequired = true;
+	#endif
+
+	#if SUPPORT_ACCELERATE_TABLES
+		sAllImages.reserve((sAllCacheImagesProxy != NULL) ? 16 : INITIAL_IMAGE_COUNT);
+	#else
+		sAllImages.reserve(INITIAL_IMAGE_COUNT);
+	#endif
+
+		// Now that shared cache is loaded, setup an versioned dylib overrides
+	#if SUPPORT_VERSIONED_PATHS
+		checkVersionedPaths();
+	#endif
+
+
+		// dyld_all_image_infos image list does not contain dyld
+		// add it as dyldPath field in dyld_all_image_infos
+		// for simulator, dyld_sim is in image list, need host dyld added
+#if TARGET_IPHONE_SIMULATOR
+		// get path of host dyld from table of syscall vectors in host dyld
+		void* addressInDyld = gSyscallHelpers;
+#else
+		// get path of dyld itself
+		void*  addressInDyld = (void*)&__dso_handle;
+#endif
+		char dyldPathBuffer[MAXPATHLEN+1];
+		int len = proc_regionfilename(getpid(), (uint64_t)(long)addressInDyld, dyldPathBuffer, MAXPATHLEN);
+		if ( len > 0 ) {
+			dyldPathBuffer[len] = '\0'; // proc_regionfilename() does not zero terminate returned string
+			if ( strcmp(dyldPathBuffer, gProcessInfo->dyldPath) != 0 )
+				gProcessInfo->dyldPath = strdup(dyldPathBuffer);
+		}
+
+		// load any inserted libraries
+		if	( sEnv.DYLD_INSERT_LIBRARIES != NULL ) {
+			for (const char* const* lib = sEnv.DYLD_INSERT_LIBRARIES; *lib != NULL; ++lib) 
+				loadInsertedDylib(*lib);
+		}
+		// record count of inserted libraries so that a flat search will look at 
+		// inserted libraries, then main, then others.
+		sInsertedDylibCount = sAllImages.size()-1;
+
+		// link main executable
+		gLinkContext.linkingMainExecutable = true;
+#if SUPPORT_ACCELERATE_TABLES
+		if ( mainExcutableAlreadyRebased ) {
+			// previous link() on main executable has already adjusted its internal pointers for ASLR
+			// work around that by rebasing by inverse amount
+			sMainExecutable->rebase(gLinkContext, -mainExecutableSlide);
+		}
+#endif
+		link(sMainExecutable, sEnv.DYLD_BIND_AT_LAUNCH, true, ImageLoader::RPathChain(NULL, NULL), -1);
+		sMainExecutable->setNeverUnloadRecursive();
 		if ( sMainExecutable->forceFlat() ) {
 			gLinkContext.bindFlat = true;
 			gLinkContext.prebindUsage = ImageLoader::kUseNoPrebinding;
 		}
-		link(sMainExecutable, bindness, ImageLoader::kDontRunInitializers);
-		result = (uintptr_t)sMainExecutable->getMain();
+
+		// link any inserted libraries
+		// do this after linking main executable so that any dylibs pulled in by inserted 
+		// dylibs (e.g. libSystem) will not be in front of dylibs the program uses
+		if ( sInsertedDylibCount > 0 ) {
+			for(unsigned int i=0; i < sInsertedDylibCount; ++i) {
+				ImageLoader* image = sAllImages[i+1];
+				link(image, sEnv.DYLD_BIND_AT_LAUNCH, true, ImageLoader::RPathChain(NULL, NULL), -1);
+				image->setNeverUnloadRecursive();
+			}
+			// only INSERTED libraries can interpose
+			// register interposing info after all inserted libraries are bound so chaining works
+			for(unsigned int i=0; i < sInsertedDylibCount; ++i) {
+				ImageLoader* image = sAllImages[i+1];
+				image->registerInterposing(gLinkContext);
+			}
+		}
+
+		// <rdar://problem/19315404> dyld should support interposition even without DYLD_INSERT_LIBRARIES
+		for (long i=sInsertedDylibCount+1; i < sAllImages.size(); ++i) {
+			ImageLoader* image = sAllImages[i];
+			if ( image->inSharedCache() )
+				continue;
+			image->registerInterposing(gLinkContext);
+		}
+	#if SUPPORT_ACCELERATE_TABLES
+		if ( (sAllCacheImagesProxy != NULL) && ImageLoader::haveInterposingTuples() ) {
+			// Accelerator tables cannot be used with implicit interposing, so relaunch with accelerator tables disabled
+			ImageLoader::clearInterposingTuples();
+			// unmap all loaded dylibs (but not main executable)
+			for (long i=1; i < sAllImages.size(); ++i) {
+				ImageLoader* image = sAllImages[i];
+				if ( image == sMainExecutable )
+					continue;
+				if ( image == sAllCacheImagesProxy )
+					continue;
+				image->setCanUnload();
+				ImageLoader::deleteImage(image);
+			}
+			// note: we don't need to worry about inserted images because if DYLD_INSERT_LIBRARIES was set we would not be using the accelerator table
+			sAllImages.clear();
+			sImageRoots.clear();
+			sImageFilesNeedingTermination.clear();
+			sImageFilesNeedingDOFUnregistration.clear();
+			sAddImageCallbacks.clear();
+			sRemoveImageCallbacks.clear();
+			sAddLoadImageCallbacks.clear();
+			sDisableAcceleratorTables = true;
+			sAllCacheImagesProxy = NULL;
+			sMappedRangesStart = NULL;
+			mainExcutableAlreadyRebased = true;
+			gLinkContext.linkingMainExecutable = false;
+			resetAllImages();
+			goto reloadAllImages;
+		}
+	#endif
+
+		// apply interposing to initial set of images
+		for(int i=0; i < sImageRoots.size(); ++i) {
+			sImageRoots[i]->applyInterposing(gLinkContext);
+		}
+		ImageLoader::applyInterposingToDyldCache(gLinkContext);
+		gLinkContext.linkingMainExecutable = false;
+
+		// Bind and notify for the main executable now that interposing has been registered
+		uint64_t bindMainExecutableStartTime = mach_absolute_time();
+		sMainExecutable->recursiveBindWithAccounting(gLinkContext, sEnv.DYLD_BIND_AT_LAUNCH, true);
+		uint64_t bindMainExecutableEndTime = mach_absolute_time();
+		ImageLoaderMachO::fgTotalBindTime += bindMainExecutableEndTime - bindMainExecutableStartTime;
+		gLinkContext.notifyBatch(dyld_image_state_bound, false);
+
+		// Bind and notify for the inserted images now interposing has been registered
+		if ( sInsertedDylibCount > 0 ) {
+			for(unsigned int i=0; i < sInsertedDylibCount; ++i) {
+				ImageLoader* image = sAllImages[i+1];
+				image->recursiveBind(gLinkContext, sEnv.DYLD_BIND_AT_LAUNCH, true);
+			}
+		}
+		
+		// <rdar://problem/12186933> do weak binding only after all inserted images linked
+		sMainExecutable->weakBind(gLinkContext);
+
+		// If cache has branch island dylibs, tell debugger about them
+		if ( (sSharedCacheLoadInfo.loadAddress != NULL) && (sSharedCacheLoadInfo.loadAddress->header.mappingOffset >= 0x78) && (sSharedCacheLoadInfo.loadAddress->header.branchPoolsOffset != 0) ) {
+			uint32_t count = sSharedCacheLoadInfo.loadAddress->header.branchPoolsCount;
+			dyld_image_info info[count];
+			const uint64_t* poolAddress = (uint64_t*)((char*)sSharedCacheLoadInfo.loadAddress + sSharedCacheLoadInfo.loadAddress->header.branchPoolsOffset);
+			// <rdar://problem/20799203> empty branch pools can be in development cache
+			if ( ((mach_header*)poolAddress)->magic == sMainExecutableMachHeader->magic ) {
+				for (int poolIndex=0; poolIndex < count; ++poolIndex) {
+					uint64_t poolAddr = poolAddress[poolIndex] + sSharedCacheLoadInfo.slide;
+					info[poolIndex].imageLoadAddress = (mach_header*)(long)poolAddr;
+					info[poolIndex].imageFilePath = "dyld_shared_cache_branch_islands";
+					info[poolIndex].imageFileModDate = 0;
+				}
+				// add to all_images list
+				addImagesToAllImages(count, info);
+				// tell gdb about new branch island images
+				gProcessInfo->notification(dyld_image_adding, count, info);
+			}
+		}
+
+		CRSetCrashLogMessage("dyld: launch, running initializers");
+	#if SUPPORT_OLD_CRT_INITIALIZATION
+		// Old way is to run initializers via a callback from crt1.o
+		if ( ! gRunInitializersOldWay ) 
+			initializeMainExecutable(); 
+	#else
+		// run all initializers
+		initializeMainExecutable(); 
+	#endif
+
+		// notify any montoring proccesses that this process is about to enter main()
+		if (dyld3::kdebug_trace_dyld_enabled(DBG_DYLD_TIMING_LAUNCH_EXECUTABLE)) {
+			dyld3::kdebug_trace_dyld_duration_end(launchTraceID, DBG_DYLD_TIMING_LAUNCH_EXECUTABLE, 0, 0, 2);
+		}
+		notifyMonitoringDyldMain();
+
+		// find entry point for main executable
+		result = (uintptr_t)sMainExecutable->getEntryFromLC_MAIN();
+		if ( result != 0 ) {
+			// main executable uses LC_MAIN, we need to use helper in libdyld to call into main()
+			if ( (gLibSystemHelpers != NULL) && (gLibSystemHelpers->version >= 9) )
+				*startGlue = (uintptr_t)gLibSystemHelpers->startGlueToCallExit;
+			else
+				halt("libdyld.dylib support not present for LC_MAIN");
+		}
+		else {
+			// main executable uses LC_UNIXTHREAD, dyld needs to let "start" in program set up for main()
+			result = (uintptr_t)sMainExecutable->getEntryFromLC_UNIXTHREAD();
+			*startGlue = 0;
+		}
+#if __has_feature(ptrauth_calls)
+		// start() calls the result pointer as a function pointer so we need to sign it.
+		result = (uintptr_t)__builtin_ptrauth_sign_unauthenticated((void*)result, 0, 0);
+#endif
 	}
 	catch(const char* message) {
+		syncAllImages();
 		halt(message);
 	}
 	catch(...) {
-		fprintf(stderr, "dyld: launch failed\n");
-	}
-	
-	// Link in any inserted libraries.  
-	// Do this after link main executable so any extra libraries pulled in by inserted libraries are at end of flat namespace
-	if ( insertLibrariesCount > 0 ) {
-		for (int i=0; i < insertLibrariesCount; ++i) {
-			try {
-				if ( insertedImages[i] != NULL )
-					link(insertedImages[i], bindness, ImageLoader::kDontRunInitializers);
-			}
-			catch (const char* message) {
-				char buf[strlen(sEnv.DYLD_INSERT_LIBRARIES[i])+50+strlen(message)];
-				sprintf(buf, "could not link inserted library: %s\n%s\n", sEnv.DYLD_INSERT_LIBRARIES[i], message);
-				halt(buf);
-			}
-		}
+		dyld::log("dyld: launch failed\n");
+	}
+
+	CRSetCrashLogMessage("dyld2 mode");
+
+	if (sSkipMain) {
+		if (dyld3::kdebug_trace_dyld_enabled(DBG_DYLD_TIMING_LAUNCH_EXECUTABLE)) {
+			dyld3::kdebug_trace_dyld_duration_end(launchTraceID, DBG_DYLD_TIMING_LAUNCH_EXECUTABLE, 0, 0, 2);
+		}
+		result = (uintptr_t)&fake_main;
+		*startGlue = (uintptr_t)gLibSystemHelpers->startGlueToCallExit;
 	}
 	
 	return result;
 }
 
 
-
-
-}; // namespace
-
-
-
+} // namespace
+
+
+