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src/ImageLoader.cpp dyld-43.1 dyld-433.5
--- dyld/dyld-43.1/src/ImageLoader.cpp
+++ dyld/dyld-433.5/src/ImageLoader.cpp
@@ -1,6 +1,6 @@
 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
  *
- * Copyright (c) 2004-2005 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2004-2010 Apple Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
@@ -24,6 +24,7 @@
 
 #define __STDC_LIMIT_MACROS
 #include <stdint.h>
+#include <stdlib.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <mach/mach.h>
@@ -33,129 +34,139 @@
 #include <sys/mman.h>
 #include <sys/param.h>
 #include <sys/mount.h>
+#include <libkern/OSAtomic.h>
 
 #include "ImageLoader.h"
 
 
+uint32_t								ImageLoader::fgImagesUsedFromSharedCache = 0;
 uint32_t								ImageLoader::fgImagesWithUsedPrebinding = 0;
+uint32_t								ImageLoader::fgImagesRequiringCoalescing = 0;
+uint32_t								ImageLoader::fgImagesHasWeakDefinitions = 0;
 uint32_t								ImageLoader::fgTotalRebaseFixups = 0;
 uint32_t								ImageLoader::fgTotalBindFixups = 0;
+uint32_t								ImageLoader::fgTotalBindSymbolsResolved = 0;
+uint32_t								ImageLoader::fgTotalBindImageSearches = 0;
 uint32_t								ImageLoader::fgTotalLazyBindFixups = 0;
 uint32_t								ImageLoader::fgTotalPossibleLazyBindFixups = 0;
+uint32_t								ImageLoader::fgTotalSegmentsMapped = 0;
+uint64_t								ImageLoader::fgTotalBytesMapped = 0;
+uint64_t								ImageLoader::fgTotalBytesPreFetched = 0;
 uint64_t								ImageLoader::fgTotalLoadLibrariesTime;
+uint64_t								ImageLoader::fgTotalObjCSetupTime = 0;
+uint64_t								ImageLoader::fgTotalDebuggerPausedTime = 0;
+uint64_t								ImageLoader::fgTotalRebindCacheTime = 0;
 uint64_t								ImageLoader::fgTotalRebaseTime;
 uint64_t								ImageLoader::fgTotalBindTime;
-uint64_t								ImageLoader::fgTotalNotifyTime;
+uint64_t								ImageLoader::fgTotalWeakBindTime;
+uint64_t								ImageLoader::fgTotalDOF;
 uint64_t								ImageLoader::fgTotalInitTime;
-uintptr_t								ImageLoader::fgNextSplitSegAddress = 0x90000000;
-uintptr_t								Segment::fgNextNonSplitSegAddress = 0x8FE00000;
-
-
-
-__attribute__((noreturn))
-void throwf(const char* format, ...) 
-{
-	va_list	list;
-	char*	p;
-	va_start(list, format);
-	vasprintf(&p, format, list);
-	va_end(list);
-	
-	const char*	t = p;
-	throw t;
-}
-
-void ImageLoader::init(const char* path, uint64_t offsetInFat, dev_t device, ino_t inode, time_t modDate)
-{
-	fPathHash = 0;
-	fPath = NULL;
-	if ( path != NULL )
-		this->setPath(path);
-	fLogicalPath = NULL;
+uint16_t								ImageLoader::fgLoadOrdinal = 0;
+uint32_t								ImageLoader::fgSymbolTrieSearchs = 0;
+std::vector<ImageLoader::InterposeTuple>ImageLoader::fgInterposingTuples;
+uintptr_t								ImageLoader::fgNextPIEDylibAddress = 0;
+
+
+
+ImageLoader::ImageLoader(const char* path, unsigned int libCount)
+	: fPath(path), fRealPath(NULL), fDevice(0), fInode(0), fLastModified(0), 
+	fPathHash(0), fDlopenReferenceCount(0), fInitializerRecursiveLock(NULL), 
+	fDepth(0), fLoadOrder(fgLoadOrdinal++), fState(0), fLibraryCount(libCount), 
+	fAllLibraryChecksumsAndLoadAddressesMatch(false), fLeaveMapped(false), fNeverUnload(false),
+	fHideSymbols(false), fMatchByInstallName(false),
+	fInterposed(false), fRegisteredDOF(false), fAllLazyPointersBound(false), 
+    fBeingRemoved(false), fAddFuncNotified(false),
+	fPathOwnedByImage(false), fIsReferencedDownward(false), 
+	fWeakSymbolsBound(false)
+{
+	if ( fPath != NULL )
+		fPathHash = hash(fPath);
+	if ( libCount > 512 )
+		dyld::throwf("too many dependent dylibs in %s", path);
+}
+
+
+void ImageLoader::deleteImage(ImageLoader* image)
+{
+	delete image;
+}
+
+
+ImageLoader::~ImageLoader()
+{
+	if ( fRealPath != NULL ) 
+		delete [] fRealPath;
+	if ( fPathOwnedByImage && (fPath != NULL) ) 
+		delete [] fPath;
+}
+
+void ImageLoader::setFileInfo(dev_t device, ino_t inode, time_t modDate)
+{
 	fDevice = device;
 	fInode = inode;
 	fLastModified = modDate;
-	fOffsetInFatFile = offsetInFat;
-	//fSegments = NULL;
-	fLibraries = NULL;
-	fLibrariesCount = 0;
-	fReferenceCount = 0;
-	fAllLibraryChecksumsAndLoadAddressesMatch = false;
-	fLeaveMapped = false;
-	fHideSymbols = false;
-	fMatchByInstallName = false;
-	fLibrariesLoaded = false;
-	fBased = false;
-	fBoundAllNonLazy = false;
-	fBoundAllLazy = false;
-	fAnnounced = false;
-	fInitialized = false;
-	fNextAddImageIndex = 0;
-}
-
-
-ImageLoader::ImageLoader(const char* path, uint64_t offsetInFat, const struct stat& info)
-{
-	init(path, offsetInFat, info.st_dev, info.st_ino, info.st_mtime);
-}
-
-ImageLoader::ImageLoader(const char* moduleName)
-{
-	init(moduleName, 0, 0, 0, 0);
-}
-
-
-ImageLoader::~ImageLoader()
-{
-	// need to read up on STL and see if this is right way to destruct vector contents
-	const unsigned int segmentCount = fSegments.size();
-	for(unsigned int i=0; i < segmentCount; ++i){
-		Segment* seg = fSegments[i];
-		delete seg;
-	}
-	if ( fPath != NULL ) 
+}
+
+void ImageLoader::setMapped(const LinkContext& context)
+{
+	fState = dyld_image_state_mapped;
+	context.notifySingle(dyld_image_state_mapped, this, NULL);  // note: can throw exception
+}
+
+int ImageLoader::compare(const ImageLoader* right) const
+{
+	if ( this->fDepth == right->fDepth ) {
+		if ( this->fLoadOrder == right->fLoadOrder )
+			return 0;
+		else if ( this->fLoadOrder < right->fLoadOrder )
+			return -1;
+		else
+			return 1;
+	}
+	else {
+		if ( this->fDepth < right->fDepth )
+			return -1;
+		else
+			return 1;
+	}
+}
+
+void ImageLoader::setPath(const char* path)
+{
+	if ( fPathOwnedByImage && (fPath != NULL) ) 
 		delete [] fPath;
-	if ( fLogicalPath != NULL ) 
-		delete [] fLogicalPath;
-}
-
-			
-void ImageLoader::setPath(const char* path)
-{
-	if ( fPath != NULL ) {
-		// if duplicate path, do nothing
-		if ( strcmp(path, fPath) == 0 )
-			return;
-		delete [] fPath;
-	}
 	fPath = new char[strlen(path)+1];
 	strcpy((char*)fPath, path);
+	fPathOwnedByImage = true;  // delete fPath when this image is destructed
 	fPathHash = hash(fPath);
-}
-
-void ImageLoader::setLogicalPath(const char* path)
-{
-	if ( fPath == NULL ) {
-		// no physical path set yet, so use this path as physical
-		this->setPath(path);
-	}
-	else if ( strcmp(path, fPath) == 0 ) {
-		// do not set logical path because it is the same as the physical path
-		fLogicalPath = NULL;
-	}
-	else {
-		fLogicalPath = new char[strlen(path)+1];
-		strcpy((char*)fLogicalPath, path);
-	}
-}
-
-const char* ImageLoader::getLogicalPath() const
-{
-	if ( fLogicalPath != NULL )
-		return fLogicalPath;
+	fRealPath = NULL;
+}
+
+void ImageLoader::setPathUnowned(const char* path)
+{
+	if ( fPathOwnedByImage && (fPath != NULL) ) {
+		delete [] fPath;
+	}
+	fPath = path;
+	fPathOwnedByImage = false;  
+	fPathHash = hash(fPath);
+}
+
+void ImageLoader::setPaths(const char* path, const char* realPath)
+{
+	this->setPath(path);
+	fRealPath = new char[strlen(realPath)+1];
+	strcpy((char*)fRealPath, realPath);
+}
+
+const char* ImageLoader::getRealPath() const 
+{ 
+	if ( fRealPath != NULL ) 
+		return fRealPath;
 	else
-		return fPath;
-}
+		return fPath; 
+}
+
 
 uint32_t ImageLoader::hash(const char* path)
 {
@@ -183,29 +194,25 @@
 	return ( (this->fDevice == stat_buf.st_dev) && (this->fInode == stat_buf.st_ino) );	
 }
 
-const char* ImageLoader::getShortName() const
+const char* ImageLoader::shortName(const char* fullName)
 {
 	// try to return leaf name
-	if ( fPath != NULL ) {
-		const char* s = strrchr(fPath, '/');
+	if ( fullName != NULL ) {
+		const char* s = strrchr(fullName, '/');
 		if ( s != NULL ) 
 			return &s[1];
 	}
-	return fPath; 
-}
-
-uint64_t ImageLoader::getOffsetInFatFile() const
-{
-	return fOffsetInFatFile;
+	return fullName;
+}
+
+const char* ImageLoader::getShortName() const
+{
+	return shortName(fPath);
 }
 
 void ImageLoader::setLeaveMapped()
 {
 	fLeaveMapped = true;
-	const unsigned int segmentCount = fSegments.size();
-	for(unsigned int i=0; i < segmentCount; ++i){
-		fSegments[i]->setUnMapWhenDestructed(false);
-	}
 }
 
 void ImageLoader::setHideExports(bool hide)
@@ -220,80 +227,120 @@
 
 bool ImageLoader::isLinked() const
 {
-	return fBoundAllNonLazy;
-}
-
-time_t ImageLoader::lastModified()
+	return (fState >= dyld_image_state_bound);
+}
+
+time_t ImageLoader::lastModified() const
 {
 	return fLastModified;
 }
 
 bool ImageLoader::containsAddress(const void* addr) const
 {
-	const unsigned int segmentCount = fSegments.size();
-	for(unsigned int i=0; i < segmentCount; ++i){
-		Segment* seg = fSegments[i];
-		const uint8_t* start = (const uint8_t*)seg->getActualLoadAddress();
-		const uint8_t* end = start + seg->getSize();
-		if ( (start <= addr) && (addr < end) && !seg->unaccessible() )
+	for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+		const uint8_t* start = (const uint8_t*)segActualLoadAddress(i);
+		const uint8_t* end = (const uint8_t*)segActualEndAddress(i);
+		if ( (start <= addr) && (addr < end) && !segUnaccessible(i) )
 			return true;
 	}
 	return false;
 }
 
-void ImageLoader::addMappedRegions(RegionsVector& regions) const
-{
-	const unsigned int segmentCount = fSegments.size();
-	for(unsigned int i=0; i < segmentCount; ++i){
-		Segment* seg = fSegments[i];
+bool ImageLoader::overlapsWithAddressRange(const void* start, const void* end) const
+{
+	for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+		const uint8_t* segStart = (const uint8_t*)segActualLoadAddress(i);
+		const uint8_t* segEnd = (const uint8_t*)segActualEndAddress(i);
+		if ( strcmp(segName(i), "__UNIXSTACK") == 0 ) {
+			// __UNIXSTACK never slides.  This is the only place that cares
+			// and checking for that segment name in segActualLoadAddress()
+			// is too expensive.
+			segStart -= getSlide();
+			segEnd -= getSlide();
+		}
+		if ( (start <= segStart) && (segStart < end) )
+			return true;
+		if ( (start <= segEnd) && (segEnd < end) )
+			return true;
+		if ( (segStart < start) && (end < segEnd) )
+			return true;
+	}
+	return false;
+}
+
+void ImageLoader::getMappedRegions(MappedRegion*& regions) const
+{
+	for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
 		MappedRegion region;
-		region.address = seg->getActualLoadAddress();
-		region.size = seg->getSize();
-		regions.push_back(region);
-	}
-}
-
-
-void ImageLoader::incrementReferenceCount()
-{
-	++fReferenceCount;
-}
-
-bool ImageLoader::decrementReferenceCount()
-{
-	return ( --fReferenceCount == 0 );
-}
+		region.address = segActualLoadAddress(i);
+		region.size = segSize(i);
+		*regions++ = region;
+	}
+}
+
+
+
+bool ImageLoader::dependsOn(ImageLoader* image) {
+	for(unsigned int i=0; i < libraryCount(); ++i) {
+		if ( libImage(i) == image )
+			return true;
+	}
+	return false;
+}
+
+
+static bool notInImgageList(const ImageLoader* image, const ImageLoader** dsiStart, const ImageLoader** dsiCur)
+{
+	for (const ImageLoader** p = dsiStart; p < dsiCur; ++p)
+		if ( *p == image )
+			return false;
+	return true;
+}
+
+bool ImageLoader::findExportedSymbolAddress(const LinkContext& context, const char* symbolName,
+											const ImageLoader* requestorImage, int requestorOrdinalOfDef,
+											bool runResolver, const ImageLoader** foundIn, uintptr_t* address) const
+{
+	const Symbol* sym = this->findExportedSymbol(symbolName, true, foundIn);
+	if ( sym != NULL ) {
+		*address = (*foundIn)->getExportedSymbolAddress(sym, context, requestorImage, runResolver);
+		return true;
+	}
+	return false;
+}
+
 
 // private method that handles circular dependencies by only search any image once
-const ImageLoader::Symbol* ImageLoader::findExportedSymbolInDependentImagesExcept(const char* name, std::set<const ImageLoader*>& dontSearchImages, ImageLoader** foundIn) const
+const ImageLoader::Symbol* ImageLoader::findExportedSymbolInDependentImagesExcept(const char* name, 
+			const ImageLoader** dsiStart, const ImageLoader**& dsiCur, const ImageLoader** dsiEnd, const ImageLoader** foundIn) const
 {
 	const ImageLoader::Symbol* sym;
 	// search self
-	if ( dontSearchImages.count(this) == 0 ) {
-		sym = this->findExportedSymbol(name, NULL, false, foundIn);
+	if ( notInImgageList(this, dsiStart, dsiCur) ) {
+		sym = this->findExportedSymbol(name, false, this->getPath(), foundIn);
 		if ( sym != NULL )
 			return sym;
-		dontSearchImages.insert(this);
+		*dsiCur++ = this;
 	}
 
 	// search directly dependent libraries
-	for (uint32_t i=0; i < fLibrariesCount; ++i) {
-		ImageLoader* dependentImage = fLibraries[i].image;
-		if ( (dependentImage != NULL) && (dontSearchImages.count(dependentImage) == 0) ) {
-			const ImageLoader::Symbol* sym = dependentImage->findExportedSymbol(name, NULL, false, foundIn);
+	for(unsigned int i=0; i < libraryCount(); ++i) {
+		ImageLoader* dependentImage = libImage(i);
+		if ( (dependentImage != NULL) && notInImgageList(dependentImage, dsiStart, dsiCur) ) {
+			sym = dependentImage->findExportedSymbol(name, false, libPath(i), foundIn);
 			if ( sym != NULL )
 				return sym;
 		}
 	}
 	
 	// search indirectly dependent libraries
-	for (uint32_t i=0; i < fLibrariesCount; ++i) {
-		ImageLoader* dependentImage = fLibraries[i].image;
-		if ( (dependentImage != NULL) && (dontSearchImages.count(dependentImage) == 0) ) {
-			const ImageLoader::Symbol* sym = dependentImage->findExportedSymbolInDependentImagesExcept(name, dontSearchImages, foundIn);
+	for(unsigned int i=0; i < libraryCount(); ++i) {
+		ImageLoader* dependentImage = libImage(i);
+		if ( (dependentImage != NULL) && notInImgageList(dependentImage, dsiStart, dsiCur) ) {
+			*dsiCur++ = dependentImage; 
+			sym = dependentImage->findExportedSymbolInDependentImagesExcept(name, dsiStart, dsiCur, dsiEnd, foundIn);
 			if ( sym != NULL )
 				return sym;
-			dontSearchImages.insert(dependentImage);
 		}
 	}
 
@@ -301,155 +348,195 @@
 }
 
 
-const ImageLoader::Symbol* ImageLoader::findExportedSymbolInDependentImages(const char* name, ImageLoader** foundIn) const
-{
-	std::set<const ImageLoader*> dontSearchImages;
-	dontSearchImages.insert(this);	// don't search this image
-	return this->findExportedSymbolInDependentImagesExcept(name, dontSearchImages, foundIn);
-}
-
-const ImageLoader::Symbol* ImageLoader::findExportedSymbolInImageOrDependentImages(const char* name, ImageLoader** foundIn) const
-{
-	std::set<const ImageLoader*> dontSearchImages;
-	return this->findExportedSymbolInDependentImagesExcept(name, dontSearchImages, foundIn);
-}
-
-
-void ImageLoader::link(const LinkContext& context, BindingLaziness bindness, InitializerRunning inits, uint32_t notifyCount)
-{
+const ImageLoader::Symbol* ImageLoader::findExportedSymbolInDependentImages(const char* name, const LinkContext& context, const ImageLoader** foundIn) const
+{
+	unsigned int imageCount = context.imageCount()+2;
+	const ImageLoader* dontSearchImages[imageCount];
+	dontSearchImages[0] = this; // don't search this image
+	const ImageLoader** cur = &dontSearchImages[1];
+	return this->findExportedSymbolInDependentImagesExcept(name, &dontSearchImages[0], cur, &dontSearchImages[imageCount], foundIn);
+}
+
+const ImageLoader::Symbol* ImageLoader::findExportedSymbolInImageOrDependentImages(const char* name, const LinkContext& context, const ImageLoader** foundIn) const
+{
+	unsigned int imageCount = context.imageCount()+2;
+	const ImageLoader* dontSearchImages[imageCount];
+	const ImageLoader** cur = &dontSearchImages[0];
+	return this->findExportedSymbolInDependentImagesExcept(name, &dontSearchImages[0], cur, &dontSearchImages[imageCount], foundIn);
+}
+
+// this is called by initializeMainExecutable() to interpose on the initial set of images
+void ImageLoader::applyInterposing(const LinkContext& context)
+{
+	if ( fgInterposingTuples.size() != 0 )
+		this->recursiveApplyInterposing(context);
+}
+
+
+uintptr_t ImageLoader::interposedAddress(const LinkContext& context, uintptr_t address, const ImageLoader* inImage, const ImageLoader* onlyInImage)
+{
+	//dyld::log("interposedAddress(0x%08llX), tupleCount=%lu\n", (uint64_t)address, fgInterposingTuples.size());
+	for (std::vector<InterposeTuple>::iterator it=fgInterposingTuples.begin(); it != fgInterposingTuples.end(); it++) {
+		//dyld::log("    interposedAddress: replacee=0x%08llX, replacement=0x%08llX, neverImage=%p, onlyImage=%p, inImage=%p\n", 
+		//				(uint64_t)it->replacee, (uint64_t)it->replacement,  it->neverImage, it->onlyImage, inImage);
+		// replace all references to 'replacee' with 'replacement'
+		if ( (address == it->replacee) && (inImage != it->neverImage) && ((it->onlyImage == NULL) || (inImage == it->onlyImage)) ) {
+			if ( context.verboseInterposing ) {
+				dyld::log("dyld interposing: replace 0x%lX with 0x%lX\n", it->replacee, it->replacement);
+			}
+			return it->replacement;
+		}
+	}
+	return address;
+}
+
+void ImageLoader::addDynamicInterposingTuples(const struct dyld_interpose_tuple array[], size_t count)
+{
+	for(size_t i=0; i < count; ++i) {
+		ImageLoader::InterposeTuple tuple;
+		tuple.replacement		= (uintptr_t)array[i].replacement;
+		tuple.neverImage		= NULL;
+		tuple.onlyImage		    = this;
+		tuple.replacee			= (uintptr_t)array[i].replacee;
+		// chain to any existing interpositions
+		for (std::vector<InterposeTuple>::iterator it=fgInterposingTuples.begin(); it != fgInterposingTuples.end(); it++) {
+			if ( (it->replacee == tuple.replacee) && (it->onlyImage == this) ) {
+				tuple.replacee = it->replacement;
+			}
+		}
+		ImageLoader::fgInterposingTuples.push_back(tuple);
+	}
+}
+
+
+void ImageLoader::link(const LinkContext& context, bool forceLazysBound, bool preflightOnly, bool neverUnload, const RPathChain& loaderRPaths, const char* imagePath)
+{
+	//dyld::log("ImageLoader::link(%s) refCount=%d, neverUnload=%d\n", imagePath, fDlopenReferenceCount, fNeverUnload);
+	
+	// clear error strings
+	(*context.setErrorStrings)(0, NULL, NULL, NULL);
+
+	uint64_t t0 = mach_absolute_time();
+	this->recursiveLoadLibraries(context, preflightOnly, loaderRPaths, imagePath);
+	context.notifyBatch(dyld_image_state_dependents_mapped, preflightOnly);
+
+	// we only do the loading step for preflights
+	if ( preflightOnly )
+		return;
+		
 	uint64_t t1 = mach_absolute_time();
-	this->recursiveLoadLibraries(context);
-	
+	context.clearAllDepths();
+	this->recursiveUpdateDepth(context.imageCount());
+
 	uint64_t t2 = mach_absolute_time();
  	this->recursiveRebase(context);
+	context.notifyBatch(dyld_image_state_rebased, false);
 	
 	uint64_t t3 = mach_absolute_time();
- 	this->recursiveBind(context, bindness);
-	
-	uint64_t t4 = mach_absolute_time();	
-	this->recursiveImageNotification(context, notifyCount);	
-	
-	if ( (inits == kRunInitializers) || (inits == kDontRunInitializersButTellObjc) ) {
-		std::vector<ImageLoader*>	newImages;
-		this->recursiveImageAnnouncement(context, newImages);	 // build bottom up list images being added
-		context.notifyAdding(newImages);	// tell gdb or anyone who cares about these
-	}
-	
-	uint64_t t5 = mach_absolute_time();
-	if ( inits == kRunInitializers ) {
-		this->recursiveInitialization(context);
-		uint64_t t6 = mach_absolute_time();
-		fgTotalInitTime += t6 - t5;
-	}
-	fgTotalLoadLibrariesTime += t2 - t1;
+ 	this->recursiveBind(context, forceLazysBound, neverUnload);
+
+	uint64_t t4 = mach_absolute_time();
+	if ( !context.linkingMainExecutable )
+		this->weakBind(context);
+	uint64_t t5 = mach_absolute_time();	
+
+	context.notifyBatch(dyld_image_state_bound, false);
+	uint64_t t6 = mach_absolute_time();	
+
+	std::vector<DOFInfo> dofs;
+	this->recursiveGetDOFSections(context, dofs);
+	context.registerDOFs(dofs);
+	uint64_t t7 = mach_absolute_time();	
+
+	// interpose any dynamically loaded images
+	if ( !context.linkingMainExecutable && (fgInterposingTuples.size() != 0) ) {
+		this->recursiveApplyInterposing(context);
+	}
+	
+	// clear error strings
+	(*context.setErrorStrings)(0, NULL, NULL, NULL);
+
+	fgTotalLoadLibrariesTime += t1 - t0;
 	fgTotalRebaseTime += t3 - t2;
 	fgTotalBindTime += t4 - t3;
-	fgTotalNotifyTime += t5 - t4;
-}
-
-
-// only called pre-main on main executable
-// if crt.c is ever cleaned up, this could go away
-void ImageLoader::runInitializers(const LinkContext& context)
-{
-		std::vector<ImageLoader*>	newImages;
-		this->recursiveImageAnnouncement(context, newImages);	 // build bottom up list images being added
-		context.notifyAdding(newImages);	// tell gdb or anyone who cares about these
-
-	this->recursiveInitialization(context);
-}
-
-// called inside _dyld_register_func_for_add_image()
-void ImageLoader::runNotification(const LinkContext& context, uint32_t notifyCount)
-{
-	this->recursiveImageNotification(context, notifyCount);
-}
-
-
-intptr_t ImageLoader::assignSegmentAddresses(const LinkContext& context)
-{
-	// preflight and calculate slide if needed
-	const unsigned int segmentCount = fSegments.size();
-	intptr_t slide = 0;
-	if ( this->segmentsCanSlide() && this->segmentsMustSlideTogether() ) {
-		bool needsToSlide = false;
-		uintptr_t lowAddr = UINTPTR_MAX;
-		uintptr_t highAddr = 0;
-		for(unsigned int i=0; i < segmentCount; ++i){
-			Segment* seg = fSegments[i];
-			const uintptr_t segLow = seg->getPreferredLoadAddress();
-			const uintptr_t segHigh = segLow + seg->getSize();
-			if ( segLow < lowAddr )
-				lowAddr = segLow;
-			if ( segHigh > highAddr )
-				highAddr = segHigh;
-				
-			if ( context.slideAndPackDylibs || !seg->hasPreferredLoadAddress() || !Segment::reserveAddressRange(seg->getPreferredLoadAddress(), seg->getSize()) )
-				needsToSlide = true;
-		}
-		if ( needsToSlide ) {
-			// find a chunk of address space to hold all segments
-			uintptr_t addr = Segment::reserveAnAddressRange(highAddr-lowAddr, context);
-			slide = addr - lowAddr;
-		}
-	} 
-	else if ( ! this->segmentsCanSlide() ) {
-		for(unsigned int i=0; i < segmentCount; ++i){
-			Segment* seg = fSegments[i];
-			if ( strcmp(seg->getName(), "__PAGEZERO") == 0 )
-				continue;
-			if ( !Segment::reserveAddressRange(seg->getPreferredLoadAddress(), seg->getSize()) )
-				throw "can't map";
-		}
-	}
-	else {
-		// mach-o does not support independently sliding segments
-	}
-	return slide;
-}
-
-
-void ImageLoader::mapSegments(int fd, uint64_t offsetInFat, uint64_t lenInFat, uint64_t fileLen, const LinkContext& context)
-{
-	if ( context.verboseMapping )
-		fprintf(stderr, "dyld: Mapping %s\n", this->getPath());
-	// find address range for image
-	intptr_t slide = this->assignSegmentAddresses(context);
-	// map in all segments
-	const unsigned int segmentCount = fSegments.size();
-	for(unsigned int i=0; i < segmentCount; ++i){
-		Segment* seg = fSegments[i];
-		seg->map(fd, offsetInFat, slide, context);		
-	}
-	// update slide to reflect load location			
-	this->setSlide(slide);
-	
-	// now that it is mapped and slide is set, mark that we should unmap it when done
-	for(unsigned int i=0; i < segmentCount; ++i){
-		fSegments[i]->setUnMapWhenDestructed(true);
-	}
-}
-
-void ImageLoader::mapSegments(const void* memoryImage, uint64_t imageLen, const LinkContext& context)
-{
-	if ( context.verboseMapping )
-		fprintf(stderr, "dyld: Mapping memory %p\n", memoryImage);
-	// find address range for image
-	intptr_t slide = this->assignSegmentAddresses(context);
-	// map in all segments
-	const unsigned int segmentCount = fSegments.size();
-	for(unsigned int i=0; i < segmentCount; ++i){
-		Segment* seg = fSegments[i];
-		seg->map(memoryImage, slide, context);		
-	}
-	// update slide to reflect load location			
-	this->setSlide(slide);
-	// set R/W permissions on all segments at slide location
-	for(unsigned int i=0; i < segmentCount; ++i){
-		Segment* seg = fSegments[i];
-		seg->setPermissions();		
-	}
-}
+	fgTotalWeakBindTime += t5 - t4;
+	fgTotalDOF += t7 - t6;
+	
+	// done with initial dylib loads
+	fgNextPIEDylibAddress = 0;
+}
+
+
+void ImageLoader::printReferenceCounts()
+{
+	dyld::log("      dlopen=%d for %s\n", fDlopenReferenceCount, getPath() );
+}
+
+
+bool ImageLoader::decrementDlopenReferenceCount() 
+{
+	if ( fDlopenReferenceCount == 0 )
+		return true;
+	--fDlopenReferenceCount;
+	return false;
+}
+
+
+// <rdar://problem/14412057> upward dylib initializers can be run too soon
+// To handle dangling dylibs which are upward linked but not downward, all upward linked dylibs
+// have their initialization postponed until after the recursion through downward dylibs
+// has completed.
+void ImageLoader::processInitializers(const LinkContext& context, mach_port_t thisThread,
+									 InitializerTimingList& timingInfo, ImageLoader::UninitedUpwards& images)
+{
+	uint32_t maxImageCount = context.imageCount()+2;
+	ImageLoader::UninitedUpwards upsBuffer[maxImageCount];
+	ImageLoader::UninitedUpwards& ups = upsBuffer[0];
+	ups.count = 0;
+	// Calling recursive init on all images in images list, building a new list of
+	// uninitialized upward dependencies.
+	for (uintptr_t i=0; i < images.count; ++i) {
+		images.images[i]->recursiveInitialization(context, thisThread, images.images[i]->getPath(), timingInfo, ups);
+	}
+	// If any upward dependencies remain, init them.
+	if ( ups.count > 0 )
+		processInitializers(context, thisThread, timingInfo, ups);
+}
+
+
+void ImageLoader::runInitializers(const LinkContext& context, InitializerTimingList& timingInfo)
+{
+	uint64_t t1 = mach_absolute_time();
+	mach_port_t thisThread = mach_thread_self();
+	ImageLoader::UninitedUpwards up;
+	up.count = 1;
+	up.images[0] = this;
+	processInitializers(context, thisThread, timingInfo, up);
+	context.notifyBatch(dyld_image_state_initialized, false);
+	mach_port_deallocate(mach_task_self(), thisThread);
+	uint64_t t2 = mach_absolute_time();
+	fgTotalInitTime += (t2 - t1);
+}
+
+
+void ImageLoader::bindAllLazyPointers(const LinkContext& context, bool recursive)
+{
+	if ( ! fAllLazyPointersBound ) {
+		fAllLazyPointersBound = true;
+
+		if ( recursive ) {
+			// bind lower level libraries first
+			for(unsigned int i=0; i < libraryCount(); ++i) {
+				ImageLoader* dependentImage = libImage(i);
+				if ( dependentImage != NULL )
+					dependentImage->bindAllLazyPointers(context, recursive);
+			}
+		}
+		// bind lazies in this image
+		this->doBindJustLazies(context);
+	}
+}
+
 
 bool ImageLoader::allDependentLibrariesAsWhenPreBound() const
 {
@@ -457,402 +544,531 @@
 }
 
 
-void ImageLoader::recursiveLoadLibraries(const LinkContext& context)
-{
-	if ( ! fLibrariesLoaded ) {
+void ImageLoader::markedUsedRecursive(const std::vector<DynamicReference>& dynamicReferences)
+{
+	// already visited here
+	if ( fMarkedInUse )
+		return;
+	fMarkedInUse = true;
+	
+	// clear mark on all statically dependent dylibs
+	for(unsigned int i=0; i < libraryCount(); ++i) {
+		ImageLoader* dependentImage = libImage(i);
+		if ( dependentImage != NULL ) {
+			dependentImage->markedUsedRecursive(dynamicReferences);
+		}
+	}
+	
+	// clear mark on all dynamically dependent dylibs
+	for (std::vector<ImageLoader::DynamicReference>::const_iterator it=dynamicReferences.begin(); it != dynamicReferences.end(); ++it) {
+		if ( it->from == this )
+			it->to->markedUsedRecursive(dynamicReferences);
+	}
+	
+}
+
+unsigned int ImageLoader::recursiveUpdateDepth(unsigned int maxDepth)
+{
+	// the purpose of this phase is to make the images sortable such that 
+	// in a sort list of images, every image that an image depends on
+	// occurs in the list before it.
+	if ( fDepth == 0 ) {
 		// break cycles
-		fLibrariesLoaded = true;
+		fDepth = maxDepth;
+		
+		// get depth of dependents
+		unsigned int minDependentDepth = maxDepth;
+		for(unsigned int i=0; i < libraryCount(); ++i) {
+			ImageLoader* dependentImage = libImage(i);
+			if ( (dependentImage != NULL) && !libIsUpward(i) ) {
+				unsigned int d = dependentImage->recursiveUpdateDepth(maxDepth);
+				if ( d < minDependentDepth )
+					minDependentDepth = d;
+			}
+		}
+	
+		// make me less deep then all my dependents
+		fDepth = minDependentDepth - 1;
+	}
+	
+	return fDepth;
+}
+
+
+void ImageLoader::recursiveLoadLibraries(const LinkContext& context, bool preflightOnly, const RPathChain& loaderRPaths, const char* loadPath)
+{
+	if ( fState < dyld_image_state_dependents_mapped ) {
+		// break cycles
+		fState = dyld_image_state_dependents_mapped;
 		
 		// get list of libraries this image needs
-		fLibrariesCount = this->doGetDependentLibraryCount();
-		fLibraries = new DependentLibrary[fLibrariesCount];
-		this->doGetDependentLibraries(fLibraries);
+		DependentLibraryInfo libraryInfos[fLibraryCount]; 
+		this->doGetDependentLibraries(libraryInfos);
+		
+		// get list of rpaths that this image adds
+		std::vector<const char*> rpathsFromThisImage;
+		this->getRPaths(context, rpathsFromThisImage);
+		const RPathChain thisRPaths(&loaderRPaths, &rpathsFromThisImage);
 		
 		// try to load each
 		bool canUsePrelinkingInfo = true; 
-		for(unsigned int i=0; i < fLibrariesCount; ++i){
-			DependentLibrary& requiredLib = fLibraries[i];
+		for(unsigned int i=0; i < fLibraryCount; ++i){
+			ImageLoader* dependentLib;
+			bool depLibReExported = false;
+			bool depLibRequired = false;
+			bool depLibCheckSumsMatch = false;
+			DependentLibraryInfo& requiredLibInfo = libraryInfos[i];
+#if DYLD_SHARED_CACHE_SUPPORT
+			if ( preflightOnly && context.inSharedCache(requiredLibInfo.name) ) {
+				// <rdar://problem/5910137> dlopen_preflight() on image in shared cache leaves it loaded but not objc initialized
+				// in preflight mode, don't even load dylib that are in the shared cache because they will never be unloaded
+				setLibImage(i, NULL, false, false);
+				continue;
+			}
+#endif
 			try {
-				requiredLib.image = context.loadLibrary(requiredLib.name, true, this->getPath(), NULL);
-				if ( requiredLib.image == this ) {
+				unsigned cacheIndex;
+				dependentLib = context.loadLibrary(requiredLibInfo.name, true, this->getPath(), &thisRPaths, cacheIndex);
+				if ( dependentLib == this ) {
 					// found circular reference, perhaps DYLD_LIBARY_PATH is causing this rdar://problem/3684168 
-					requiredLib.image = context.loadLibrary(requiredLib.name, false, NULL, NULL);
-					if ( requiredLib.image != this )
-						fprintf(stderr, "dyld: warning DYLD_ setting caused circular dependency in %s\n", this->getPath());
+					dependentLib = context.loadLibrary(requiredLibInfo.name, false, NULL, NULL, cacheIndex);
+					if ( dependentLib != this )
+						dyld::warn("DYLD_ setting caused circular dependency in %s\n", this->getPath());
 				}
-				LibraryInfo actualInfo = requiredLib.image->doGetLibraryInfo();
-				requiredLib.checksumMatches = ( actualInfo.checksum == requiredLib.info.checksum );
+				if ( fNeverUnload )
+					dependentLib->setNeverUnload();
+				if ( requiredLibInfo.upward ) {
+				}
+				else { 
+					dependentLib->fIsReferencedDownward = true;
+				}
+				LibraryInfo actualInfo = dependentLib->doGetLibraryInfo(requiredLibInfo.info);
+				depLibRequired = requiredLibInfo.required;
+				depLibCheckSumsMatch = ( actualInfo.checksum == requiredLibInfo.info.checksum );
+				depLibReExported = requiredLibInfo.reExported;
+				if ( ! depLibReExported ) {
+					// for pre-10.5 binaries that did not use LC_REEXPORT_DYLIB
+					depLibReExported = dependentLib->isSubframeworkOf(context, this) || this->hasSubLibrary(context, dependentLib);
+				}
 				// check found library version is compatible
-				if ( actualInfo.minVersion < requiredLib.info.minVersion ) {
-					throwf("Incompatible library version: %s requires version %d.%d.%d or later, but %s provides version %d.%d.%d",
-							this->getShortName(), requiredLib.info.minVersion >> 16, (requiredLib.info.minVersion >> 8) & 0xff, requiredLib.info.minVersion & 0xff,
-							requiredLib.image->getShortName(), actualInfo.minVersion >> 16, (actualInfo.minVersion >> 8) & 0xff, actualInfo.minVersion & 0xff);
+				// <rdar://problem/89200806> 0xFFFFFFFF is wildcard that matches any version
+				if ( (requiredLibInfo.info.minVersion != 0xFFFFFFFF) && (actualInfo.minVersion < requiredLibInfo.info.minVersion) ) {
+					// record values for possible use by CrashReporter or Finder
+					dyld::throwf("Incompatible library version: %s requires version %d.%d.%d or later, but %s provides version %d.%d.%d",
+							this->getShortName(), requiredLibInfo.info.minVersion >> 16, (requiredLibInfo.info.minVersion >> 8) & 0xff, requiredLibInfo.info.minVersion & 0xff,
+							dependentLib->getShortName(), actualInfo.minVersion >> 16, (actualInfo.minVersion >> 8) & 0xff, actualInfo.minVersion & 0xff);
 				}
-				// prebinding for this image disabled if any dependent library changed or slid
-				if ( !requiredLib.checksumMatches || (requiredLib.image->getSlide() != 0) )
+				// prebinding for this image disabled if any dependent library changed
+				//if ( !depLibCheckSumsMatch )
+				//	canUsePrelinkingInfo = false;
+				// prebinding for this image disabled unless both this and dependent are in the shared cache
+				if ( !dependentLib->inSharedCache() || !this->inSharedCache() )
 					canUsePrelinkingInfo = false;
+					
 				//if ( context.verbosePrebinding ) {
 				//	if ( !requiredLib.checksumMatches )
-				//		fprintf(stderr, "dyld: checksum mismatch, (%lld v %lld) for %s referencing %s\n", requiredLib.info.checksum, actualInfo.checksum, this->getPath(), 	requiredLib.image->getPath());		
-				//	if ( requiredLib.image->getSlide() != 0 )
-				//		fprintf(stderr, "dyld: dependent library slid for %s referencing %s\n", this->getPath(), requiredLib.image->getPath());		
+				//		fprintf(stderr, "dyld: checksum mismatch, (%u v %u) for %s referencing %s\n", 
+				//			requiredLibInfo.info.checksum, actualInfo.checksum, this->getPath(), 	dependentLib->getPath());		
+				//	if ( dependentLib->getSlide() != 0 )
+				//		fprintf(stderr, "dyld: dependent library slid for %s referencing %s\n", this->getPath(), dependentLib->getPath());		
 				//}
 			}
 			catch (const char* msg) {
 				//if ( context.verbosePrebinding )
-				//	fprintf(stderr, "dyld: exception during processing for %s referencing %s\n", this->getPath(), requiredLib.image->getPath());		
-				if ( requiredLib.required ) {
-					const char* formatString = "Library not loaded: %s\n  Referenced from: %s\n  Reason: %s";
-					const char* referencedFrom = this->getPath();
-					char buf[strlen(requiredLib.name)+strlen(referencedFrom)+strlen(formatString)+strlen(msg)+2];
-					sprintf(buf, formatString, requiredLib.name, referencedFrom, msg);
-					throw strdup(buf);  // this is a leak if exception doesn't halt program
+				//	fprintf(stderr, "dyld: exception during processing for %s referencing %s\n", this->getPath(), dependentLib->getPath());		
+				if ( requiredLibInfo.required ) {
+					fState = dyld_image_state_mapped;
+					// record values for possible use by CrashReporter or Finder
+					if ( strstr(msg, "Incompatible library version") != NULL )
+						(*context.setErrorStrings)(DYLD_EXIT_REASON_DYLIB_WRONG_VERSION, this->getPath(), requiredLibInfo.name, NULL);
+					else if ( strstr(msg, "architecture") != NULL )
+						(*context.setErrorStrings)(DYLD_EXIT_REASON_DYLIB_WRONG_ARCH, this->getPath(), requiredLibInfo.name, NULL);
+					else if ( strstr(msg, "file system sandbox") != NULL )
+						(*context.setErrorStrings)(DYLD_EXIT_REASON_FILE_SYSTEM_SANDBOX, this->getPath(), requiredLibInfo.name, NULL);
+					else if ( strstr(msg, "code signature") != NULL )
+						(*context.setErrorStrings)(DYLD_EXIT_REASON_CODE_SIGNATURE, this->getPath(), requiredLibInfo.name, NULL);
+					else if ( strstr(msg, "malformed") != NULL )
+						(*context.setErrorStrings)(DYLD_EXIT_REASON_MALFORMED_MACHO, this->getPath(), requiredLibInfo.name, NULL);
+					else
+						(*context.setErrorStrings)(DYLD_EXIT_REASON_DYLIB_MISSING, this->getPath(), requiredLibInfo.name, NULL);
+					const char* newMsg = dyld::mkstringf("Library not loaded: %s\n  Referenced from: %s\n  Reason: %s", requiredLibInfo.name, this->getRealPath(), msg);
+					free((void*)msg); 	// our free() will do nothing if msg is a string literal
+					throw newMsg;
 				}
+				free((void*)msg); 	// our free() will do nothing if msg is a string literal
 				// ok if weak library not found
-				requiredLib.image = NULL;
+				dependentLib = NULL;
 				canUsePrelinkingInfo = false;  // this disables all prebinding, we may want to just slam import vectors for this lib to zero
 			}
+			setLibImage(i, dependentLib, depLibReExported, requiredLibInfo.upward);
 		}
 		fAllLibraryChecksumsAndLoadAddressesMatch = canUsePrelinkingInfo;
 
 		// tell each to load its dependents
-		for(unsigned int i=0; i < fLibrariesCount; ++i){
-			DependentLibrary& libInfo = fLibraries[i];
-			if ( libInfo.image != NULL ) {	
-				libInfo.isSubFramework = libInfo.image->isSubframeworkOf(context, this);
-				libInfo.isReExported = libInfo.isSubFramework || this->hasSubLibrary(context, libInfo.image);
-				//if ( libInfo.isReExported  )
-				//	fprintf(stderr, "%s re-exports %s\n", strrchr(this->getPath(), '/'), strrchr(libInfo.image->getPath(),'/'));
-				libInfo.image->recursiveLoadLibraries(context);
+		for(unsigned int i=0; i < libraryCount(); ++i) {
+			ImageLoader* dependentImage = libImage(i);
+			if ( dependentImage != NULL ) {	
+				dependentImage->recursiveLoadLibraries(context, preflightOnly, thisRPaths, libraryInfos[i].name);
 			}
 		}
 		
 		// do deep prebind check
 		if ( fAllLibraryChecksumsAndLoadAddressesMatch ) {
-			for(unsigned int i=0; i < fLibrariesCount; ++i){
-				const DependentLibrary& libInfo = fLibraries[i];
-				if ( libInfo.image != NULL ) {
-					if ( !libInfo.image->allDependentLibrariesAsWhenPreBound() )
+			for(unsigned int i=0; i < libraryCount(); ++i){
+				ImageLoader* dependentImage = libImage(i);
+				if ( dependentImage != NULL ) {	
+					if ( !dependentImage->allDependentLibrariesAsWhenPreBound() )
 						fAllLibraryChecksumsAndLoadAddressesMatch = false;
 				}
 			}
 		}
 		
+		// free rpaths (getRPaths() malloc'ed each string)
+		for(std::vector<const char*>::iterator it=rpathsFromThisImage.begin(); it != rpathsFromThisImage.end(); ++it) {
+			const char* str = *it;
+			free((void*)str);
+		}
+		
 	}
 }
 
 void ImageLoader::recursiveRebase(const LinkContext& context)
 { 
-	if ( ! fBased ) {
+	if ( fState < dyld_image_state_rebased ) {
 		// break cycles
-		fBased = true;
+		fState = dyld_image_state_rebased;
 		
 		try {
 			// rebase lower level libraries first
-			for(unsigned int i=0; i < fLibrariesCount; ++i){
-				DependentLibrary& libInfo = fLibraries[i];
-				if ( libInfo.image != NULL )
-					libInfo.image->recursiveRebase(context);
+			for(unsigned int i=0; i < libraryCount(); ++i) {
+				ImageLoader* dependentImage = libImage(i);
+				if ( dependentImage != NULL )
+					dependentImage->recursiveRebase(context);
 			}
 				
 			// rebase this image
 			doRebase(context);
+			
+			// notify
+			context.notifySingle(dyld_image_state_rebased, this, NULL);
 		}
 		catch (const char* msg) {
 			// this image is not rebased
-			fBased = false;
-			throw msg;
-		}
-	}
-}
-
-
-
-
-void ImageLoader::recursiveBind(const LinkContext& context, BindingLaziness bindness)
-{
-	// normally just non-lazy pointers are bound up front,
-	// but DYLD_BIND_AT_LAUNCH will cause lazy pointers to be bound up from
-	// and some dyld API's bind all lazys at runtime
-	bool nonLazy = false;
-	bool lazy = false;
-	switch( bindness ) {
-		case kNonLazyOnly:
-			nonLazy = true;
-			break;
-		case kLazyAndNonLazy:
-			nonLazy = true;
-			lazy = true;
-			break;
-		case kLazyOnly:
-		case kLazyOnlyNoDependents:
-			lazy = true;
-			break;
-	}
-	const bool doNonLazy = nonLazy && !fBoundAllNonLazy;
-	const bool doLazy = lazy && !fBoundAllLazy;
-	if ( doNonLazy || doLazy ) {
+			fState = dyld_image_state_dependents_mapped;
+            CRSetCrashLogMessage2(NULL);
+			throw;
+		}
+	}
+}
+
+void ImageLoader::recursiveApplyInterposing(const LinkContext& context)
+{ 
+	if ( ! fInterposed ) {
 		// break cycles
-		bool oldBoundAllNonLazy = fBoundAllNonLazy;
-		bool oldBoundAllLazy = fBoundAllLazy;
-		fBoundAllNonLazy = fBoundAllNonLazy || nonLazy;
-		fBoundAllLazy = fBoundAllLazy || lazy;
-		
+		fInterposed = true;
+		
+		try {
+			// interpose lower level libraries first
+			for(unsigned int i=0; i < libraryCount(); ++i) {
+				ImageLoader* dependentImage = libImage(i);
+				if ( dependentImage != NULL )
+					dependentImage->recursiveApplyInterposing(context);
+			}
+				
+			// interpose this image
+			doInterpose(context);
+		}
+		catch (const char* msg) {
+			// this image is not interposed
+			fInterposed = false;
+			throw;
+		}
+	}
+}
+
+
+
+void ImageLoader::recursiveBind(const LinkContext& context, bool forceLazysBound, bool neverUnload)
+{
+	// Normally just non-lazy pointers are bound immediately.
+	// The exceptions are:
+	//   1) DYLD_BIND_AT_LAUNCH will cause lazy pointers to be bound immediately
+	//   2) some API's (e.g. RTLD_NOW) can cause lazy pointers to be bound immediately
+	if ( fState < dyld_image_state_bound ) {
+		// break cycles
+		fState = dyld_image_state_bound;
+	
 		try {
 			// bind lower level libraries first
-			if ( bindness != kLazyOnlyNoDependents ) {
-				for(unsigned int i=0; i < fLibrariesCount; ++i){
-					DependentLibrary& libInfo = fLibraries[i];
-					if ( libInfo.image != NULL )
-						libInfo.image->recursiveBind(context, bindness);
-				}
+			for(unsigned int i=0; i < libraryCount(); ++i) {
+				ImageLoader* dependentImage = libImage(i);
+				if ( dependentImage != NULL )
+					dependentImage->recursiveBind(context, forceLazysBound, neverUnload);
 			}
 			// bind this image
-			if ( doLazy && !doNonLazy )
-				doBind(context, kLazyOnly);	
-			else if ( !doLazy && doNonLazy )
-				doBind(context, kNonLazyOnly);
-			else 
-				doBind(context, kLazyAndNonLazy);
+			this->doBind(context, forceLazysBound);	
+			// mark if lazys are also bound
+			if ( forceLazysBound || this->usablePrebinding(context) )
+				fAllLazyPointersBound = true;
+			// mark as never-unload if requested
+			if ( neverUnload )
+				this->setNeverUnload();
+				
+			context.notifySingle(dyld_image_state_bound, this, NULL);
 		}
 		catch (const char* msg) {
 			// restore state
-			fBoundAllNonLazy = oldBoundAllNonLazy;
-			fBoundAllLazy = oldBoundAllLazy;
-			throw msg;
-		}
-	}
-}
-
-//
-// This is complex because _dyld_register_func_for_add_image() is defined to not only
-// notify you of future image loads, but also of all currently loaded images.  Therefore
-// each image needs to track that all add-image-funcs have been notified about it.
-// Since add-image-funcs cannot be removed, each has a unique index and each image
-// records the thru which index notificiation has already been done.
-//
-void ImageLoader::recursiveImageNotification(const LinkContext& context, uint32_t addImageCount)
-{
-	if ( fNextAddImageIndex < addImageCount ) {
+			fState = dyld_image_state_rebased;
+            CRSetCrashLogMessage2(NULL);
+			throw;
+		}
+	}
+}
+
+void ImageLoader::weakBind(const LinkContext& context)
+{
+	if ( context.verboseWeakBind )
+		dyld::log("dyld: weak bind start:\n");
+	uint64_t t1 = mach_absolute_time();
+	// get set of ImageLoaders that participate in coalecsing
+	ImageLoader* imagesNeedingCoalescing[fgImagesRequiringCoalescing];
+	unsigned imageIndexes[fgImagesRequiringCoalescing];
+	int count = context.getCoalescedImages(imagesNeedingCoalescing, imageIndexes);
+	
+	// count how many have not already had weakbinding done
+	int countNotYetWeakBound = 0;
+	int countOfImagesWithWeakDefinitionsNotInSharedCache = 0;
+	for(int i=0; i < count; ++i) {
+		if ( ! imagesNeedingCoalescing[i]->weakSymbolsBound(imageIndexes[i]) )
+			++countNotYetWeakBound;
+		if ( ! imagesNeedingCoalescing[i]->inSharedCache() )
+			++countOfImagesWithWeakDefinitionsNotInSharedCache;
+	}
+
+	// don't need to do any coalescing if only one image has overrides, or all have already been done
+	if ( (countOfImagesWithWeakDefinitionsNotInSharedCache > 0) && (countNotYetWeakBound > 0) ) {
+		// make symbol iterators for each
+		ImageLoader::CoalIterator iterators[count];
+		ImageLoader::CoalIterator* sortedIts[count];
+		for(int i=0; i < count; ++i) {
+			imagesNeedingCoalescing[i]->initializeCoalIterator(iterators[i], i, imageIndexes[i]);
+			sortedIts[i] = &iterators[i];
+			if ( context.verboseWeakBind )
+				dyld::log("dyld: weak bind load order %d/%d for %s\n", i, count, imagesNeedingCoalescing[i]->getIndexedPath(imageIndexes[i]));
+		}
+		
+		// walk all symbols keeping iterators in sync by 
+		// only ever incrementing the iterator with the lowest symbol 
+		int doneCount = 0;
+		while ( doneCount != count ) {
+			//for(int i=0; i < count; ++i)
+			//	dyld::log("sym[%d]=%s ", sortedIts[i]->loadOrder, sortedIts[i]->symbolName);
+			//dyld::log("\n");
+			// increment iterator with lowest symbol
+			if ( sortedIts[0]->image->incrementCoalIterator(*sortedIts[0]) )
+				++doneCount; 
+			// re-sort iterators
+			for(int i=1; i < count; ++i) {
+				int result = strcmp(sortedIts[i-1]->symbolName, sortedIts[i]->symbolName);
+				if ( result == 0 )
+					sortedIts[i-1]->symbolMatches = true;
+				if ( result > 0 ) {
+					// new one is bigger then next, so swap
+					ImageLoader::CoalIterator* temp = sortedIts[i-1];
+					sortedIts[i-1] = sortedIts[i];
+					sortedIts[i] = temp;
+				}
+				if ( result < 0 )
+					break;
+			}
+			// process all matching symbols just before incrementing the lowest one that matches
+			if ( sortedIts[0]->symbolMatches && !sortedIts[0]->done ) {
+				const char* nameToCoalesce = sortedIts[0]->symbolName;
+				// pick first symbol in load order (and non-weak overrides weak)
+				uintptr_t targetAddr = 0;
+				ImageLoader* targetImage = NULL;
+				unsigned targetImageIndex = 0;
+				for(int i=0; i < count; ++i) {
+					if ( strcmp(iterators[i].symbolName, nameToCoalesce) == 0 ) {
+						if ( context.verboseWeakBind )
+							dyld::log("dyld: weak bind, found %s weak=%d in %s \n", nameToCoalesce, iterators[i].weakSymbol, iterators[i].image->getIndexedPath((unsigned)iterators[i].imageIndex));
+						if ( iterators[i].weakSymbol ) {
+							if ( targetAddr == 0 ) {
+								targetAddr = iterators[i].image->getAddressCoalIterator(iterators[i], context);
+								if ( targetAddr != 0 ) {
+									targetImage = iterators[i].image;
+									targetImageIndex = (unsigned)iterators[i].imageIndex;
+								}
+							}
+						}
+						else {
+							targetAddr = iterators[i].image->getAddressCoalIterator(iterators[i], context);
+							if ( targetAddr != 0 ) {
+								targetImage = iterators[i].image;
+								targetImageIndex = (unsigned)iterators[i].imageIndex;
+								// strong implementation found, stop searching
+								break;
+							}
+						}
+					}
+				}
+				// tell each to bind to this symbol (unless already bound)
+				if ( targetAddr != 0 ) {
+					if ( context.verboseWeakBind ) {
+						dyld::log("dyld: weak binding all uses of %s to copy from %s\n",
+									nameToCoalesce, targetImage->getIndexedShortName(targetImageIndex));
+					}
+					for(int i=0; i < count; ++i) {
+						if ( strcmp(iterators[i].symbolName, nameToCoalesce) == 0 ) {
+							if ( context.verboseWeakBind ) {
+								dyld::log("dyld: weak bind, setting all uses of %s in %s to 0x%lX from %s\n",
+											nameToCoalesce, iterators[i].image->getIndexedShortName((unsigned)iterators[i].imageIndex),
+											targetAddr, targetImage->getIndexedShortName(targetImageIndex));
+							}
+							if ( ! iterators[i].image->weakSymbolsBound(imageIndexes[i]) )
+								iterators[i].image->updateUsesCoalIterator(iterators[i], targetAddr, targetImage, targetImageIndex, context);
+							iterators[i].symbolMatches = false; 
+						}
+					}
+				}
+				
+			}
+		}
+		
+		// mark all as having all weak symbols bound
+		for(int i=0; i < count; ++i) {
+			imagesNeedingCoalescing[i]->setWeakSymbolsBound(imageIndexes[i]);
+		}
+	}
+	uint64_t t2 = mach_absolute_time();
+	fgTotalWeakBindTime += t2  - t1;
+	
+	if ( context.verboseWeakBind )
+		dyld::log("dyld: weak bind end\n");
+}
+
+
+
+void ImageLoader::recursiveGetDOFSections(const LinkContext& context, std::vector<DOFInfo>& dofs)
+{
+	if ( ! fRegisteredDOF ) {
 		// break cycles
-		const uint32_t initIndex = fNextAddImageIndex;
-		fNextAddImageIndex = addImageCount;
-	
-		// notify all requestors about this image
-		context.imageNotification(this, initIndex);
-	
-		// notify about lower level libraries first
-		for(unsigned int i=0; i < fLibrariesCount; ++i){
-			DependentLibrary& libInfo = fLibraries[i];
-			if ( libInfo.image != NULL )
-				libInfo.image->recursiveImageNotification(context, addImageCount);
-		}
-	}
-}
-
-
-void ImageLoader::recursiveImageAnnouncement(const LinkContext& context, std::vector<ImageLoader*>& newImages)
-{
-	if ( ! fAnnounced ) {
+		fRegisteredDOF = true;
+		
+		// gather lower level libraries first
+		for(unsigned int i=0; i < libraryCount(); ++i) {
+			ImageLoader* dependentImage = libImage(i);
+			if ( dependentImage != NULL )
+				dependentImage->recursiveGetDOFSections(context, dofs);
+		}
+		this->doGetDOFSections(context, dofs);
+	}
+}
+
+void ImageLoader::setNeverUnloadRecursive() {
+	if ( ! fNeverUnload ) {
 		// break cycles
-		fAnnounced = true;
-		
-		// announce lower level libraries first
-		for(unsigned int i=0; i < fLibrariesCount; ++i){
-			DependentLibrary& libInfo = fLibraries[i];
-			if ( libInfo.image != NULL )
-				libInfo.image->recursiveImageAnnouncement(context, newImages);
-		}
-		
-		// add to list of images to notify gdb about
-		newImages.push_back(this);
-		//fprintf(stderr, "next size = %d\n", newImages.size());
-		
-		// remember that this image wants to be notified about other images
-		 if ( this->hasImageNotification() )
-			context.addImageNeedingNotification(this);
-	}
-}
-
-
-
-void ImageLoader::recursiveInitialization(const LinkContext& context)
-{
-	if ( ! fInitialized ) {
+		fNeverUnload = true;
+		
+		// gather lower level libraries first
+		for(unsigned int i=0; i < libraryCount(); ++i) {
+			ImageLoader* dependentImage = libImage(i);
+			if ( dependentImage != NULL )
+				dependentImage->setNeverUnloadRecursive();
+		}
+	}
+}
+
+void ImageLoader::recursiveSpinLock(recursive_lock& rlock)
+{
+	// try to set image's ivar fInitializerRecursiveLock to point to this lock_info
+	// keep trying until success (spin)
+	while ( ! OSAtomicCompareAndSwapPtrBarrier(NULL, &rlock, (void**)&fInitializerRecursiveLock) ) {
+		// if fInitializerRecursiveLock already points to a different lock_info, if it is for
+		// the same thread we are on, the increment the lock count, otherwise continue to spin
+		if ( (fInitializerRecursiveLock != NULL) && (fInitializerRecursiveLock->thread == rlock.thread) )
+			break;
+	}
+	++(fInitializerRecursiveLock->count); 
+}
+
+void ImageLoader::recursiveSpinUnLock()
+{
+	if ( --(fInitializerRecursiveLock->count) == 0 )
+		fInitializerRecursiveLock = NULL;
+}
+
+void ImageLoader::InitializerTimingList::addTime(const char* name, uint64_t time)
+{
+	for (int i=0; i < count; ++i) {
+		if ( strcmp(images[i].shortName, name) == 0 ) {
+			images[i].initTime += time;
+			return;
+		}
+	}
+	images[count].initTime = time;
+	images[count].shortName = name;
+	++count;
+}
+
+void ImageLoader::recursiveInitialization(const LinkContext& context, mach_port_t this_thread, const char* pathToInitialize,
+										  InitializerTimingList& timingInfo, UninitedUpwards& uninitUps)
+{
+	recursive_lock lock_info(this_thread);
+	recursiveSpinLock(lock_info);
+
+	if ( fState < dyld_image_state_dependents_initialized-1 ) {
+		uint8_t oldState = fState;
 		// break cycles
-		fInitialized = true;
-
+		fState = dyld_image_state_dependents_initialized-1;
 		try {
 			// initialize lower level libraries first
-			for(unsigned int i=0; i < fLibrariesCount; ++i){
-				DependentLibrary& libInfo = fLibraries[i];
-				if ( libInfo.image != NULL )
-					libInfo.image->recursiveInitialization(context);
+			for(unsigned int i=0; i < libraryCount(); ++i) {
+				ImageLoader* dependentImage = libImage(i);
+				if ( dependentImage != NULL ) {
+					// don't try to initialize stuff "above" me yet
+					if ( libIsUpward(i) ) {
+						uninitUps.images[uninitUps.count] = dependentImage;
+						uninitUps.count++;
+					}
+					else if ( dependentImage->fDepth >= fDepth ) {
+						dependentImage->recursiveInitialization(context, this_thread, libPath(i), timingInfo, uninitUps);
+					}
+                }
 			}
 			
 			// record termination order
 			if ( this->needsTermination() )
 				context.terminationRecorder(this);
 			
+			// let objc know we are about to initialize this image
+			uint64_t t1 = mach_absolute_time();
+			fState = dyld_image_state_dependents_initialized;
+			oldState = fState;
+			context.notifySingle(dyld_image_state_dependents_initialized, this, &timingInfo);
+			
 			// initialize this image
-			this->doInitialization(context);
+			bool hasInitializers = this->doInitialization(context);
+
+			// let anyone know we finished initializing this image
+			fState = dyld_image_state_initialized;
+			oldState = fState;
+			context.notifySingle(dyld_image_state_initialized, this, NULL);
+			
+			if ( hasInitializers ) {
+				uint64_t t2 = mach_absolute_time();
+				timingInfo.addTime(this->getShortName(), t2-t1);
+			}
 		}
 		catch (const char* msg) {
 			// this image is not initialized
-			fInitialized = false;
-			throw msg;
-		}
-	}
-}
-
-void ImageLoader::reprebindCommit(const LinkContext& context, bool commit, bool unmapOld)
-{
-	// do nothing on unprebound images
-	if ( ! this->isPrebindable() )
-		return;
-
-	// do nothing if prebinding is up to date
-	if ( this->usablePrebinding(context) )
-		return;
-		
-	// make sure we are not replacing a symlink with a file
-	char realFilePath[PATH_MAX];
-	if ( realpath(this->getPath(), realFilePath) == NULL ) {
-		throwf("realpath() failed on %s, errno=%d", this->getPath(), errno);
-	}
-	// recreate temp file name
-	char tempFilePath[strlen(realFilePath)+strlen("_redoprebinding")+2];
-	ImageLoader::addSuffix(realFilePath, "_redoprebinding", tempFilePath);
-
-	if ( commit ) {
-		// all files successfully reprebound, so do swap
-		int result = rename(tempFilePath, realFilePath);
-		if ( result != 0 ) {
-			// if there are two dylibs with the same install path, the second will fail to prebind
-			// because the _redoprebinding temp file is gone.  In that case, log and go on.
-			if ( errno == ENOENT )
-				fprintf(stderr, "update_prebinding: temp file missing: %s\n", tempFilePath);
-			else
-				throwf("can't swap temporary re-prebound file: rename(%s,%s) returned errno=%d", tempFilePath, realFilePath, errno);
-		}
-		else if ( unmapOld ) {
-			this->prebindUnmap(context);
-		}
-	}
-	else {
-		// something went wrong during prebinding, delete the temp files
-		unlink(tempFilePath);
-	}
-}
-
-uint64_t ImageLoader::reprebind(const LinkContext& context, time_t timestamp)
-{
-	// do nothing on unprebound images
-	if ( ! this->isPrebindable() )
-		return INT64_MAX;
-
-	// do nothing if prebinding is up to date
-	if ( this->usablePrebinding(context) ) {
-		if ( context.verbosePrebinding )
-			fprintf(stderr, "dyld: no need to re-prebind: %s\n", this->getPath());
-		return INT64_MAX;
-	}
-	// recreate temp file name
-	char realFilePath[PATH_MAX];
-	if ( realpath(this->getPath(), realFilePath) == NULL ) {
-		throwf("realpath() failed on %s, errno=%d", this->getPath(), errno);
-	}
-	char tempFilePath[strlen(realFilePath)+strlen("_redoprebinding")+2];
-	ImageLoader::addSuffix(realFilePath, "_redoprebinding", tempFilePath);
-
-	// make copy of file and map it in
-	uint8_t* fileToPrebind;
-	uint64_t fileToPrebindSize;
-	uint64_t freespace = this->copyAndMap(tempFilePath, &fileToPrebind, &fileToPrebindSize);
-
-	// do format specific prebinding
-	this->doPrebinding(context, timestamp, fileToPrebind);
-	
-	// flush and swap files
-	int result = msync(fileToPrebind, fileToPrebindSize, MS_ASYNC);
-	if ( result != 0 )
-		throw "error syncing re-prebound file";
-	result = munmap(fileToPrebind, fileToPrebindSize);
-	if ( result != 0 )
-		throw "error unmapping re-prebound file";
-
-	// log
-	if ( context.verbosePrebinding )
-		fprintf(stderr, "dyld: re-prebound: %p %s\n", this->machHeader(), this->getPath());
-	
-	return freespace;
-}
-
-uint64_t ImageLoader::copyAndMap(const char* tempFile, uint8_t** fileToPrebind, uint64_t* fileToPrebindSize) 
-{
-	// reopen dylib 
-	int src = open(this->getPath(), O_RDONLY);	
-	if ( src == -1 )
-		throw "can't open image";
-	struct stat stat_buf;
-	if ( fstat(src, &stat_buf) == -1)
-		throw "can't stat image";
-	if ( stat_buf.st_mtime != fLastModified )
-		throw "image file changed since it was loaded";
-		
-	// create new file with all same permissions to hold copy of dylib 
-	unlink(tempFile);
-	int dst = open(tempFile, O_CREAT | O_RDWR | O_TRUNC, stat_buf.st_mode);	
-	if ( dst == -1 )
-		throw "can't create temp image";
-
-	// mark source as "don't cache"
-	(void)fcntl(src, F_NOCACHE, 1);
-	// we want to cache the dst because we are about to map it in and modify it
-	
-	// copy permission bits
-	if ( chmod(tempFile, stat_buf.st_mode & 07777) == -1 )
-		throwf("can't chmod temp image.  errno=%d for %s", errno, this->getPath());
-	if ( chown(tempFile, stat_buf.st_uid, stat_buf.st_gid) == -1)
-		throwf("can't chown temp image.  errno=%d for %s", errno, this->getPath());
-		  
-	// copy contents
-	ssize_t len;
-	const uint32_t kBufferSize = 128*1024;
-	static uint8_t* buffer = NULL;
-	if ( buffer == NULL ) {
-		vm_address_t addr = 0;
-		if ( vm_allocate(mach_task_self(), &addr, kBufferSize, true /*find range*/) == KERN_SUCCESS )
-			buffer = (uint8_t*)addr;
-		else
-			throw "can't allcoate copy buffer";
-	}
-	while ( (len = read(src, buffer, kBufferSize)) > 0 ) {
-		if ( write(dst, buffer, len) == -1 )
-			throwf("write failure copying dylib errno=%d for %s", errno, this->getPath());
-	}
-	
-	// map in dst file
-	*fileToPrebindSize = stat_buf.st_size - fOffsetInFatFile; // this may map in too much, but it does not matter
-	*fileToPrebind = (uint8_t*)mmap(NULL, *fileToPrebindSize, PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, dst, fOffsetInFatFile);
-	if ( *fileToPrebind == (uint8_t*)(-1) )
-		throw "can't mmap temp image";
-		
-	// get free space remaining on dst volume
-	struct statfs statfs_buf;
-	if ( fstatfs(dst, &statfs_buf) != 0 )
-		throwf("can't fstatfs(), errno=%d for %s", errno, tempFile);
-	uint64_t freespace = statfs_buf.f_bavail * statfs_buf.f_bsize;
-	
-	// closing notes:  
-	//		ok to close file after mapped in
-	//		ok to throw above without closing file because the throw will terminate update_prebinding
-	int result1 = close(dst);
-	int result2 = close(src);
-	if ( (result1 != 0) || (result2 != 0) )
-		throw "can't close file";
-		
-	return freespace;
+			fState = oldState;
+			recursiveSpinUnLock();
+			throw;
+		}
+	}
+	
+	recursiveSpinUnLock();
 }
 
 
@@ -862,58 +1078,113 @@
 	if ( sUnitsPerSecond == 0 ) {
 		struct mach_timebase_info timeBaseInfo;
 		if ( mach_timebase_info(&timeBaseInfo) == KERN_SUCCESS ) {
-			sUnitsPerSecond = timeBaseInfo.denom;
+			sUnitsPerSecond = 1000000000ULL * timeBaseInfo.denom / timeBaseInfo.numer;
 		}
 	}
 	if ( partTime < sUnitsPerSecond ) {
-		uint32_t milliSecondsTimeTen = (partTime*10000)/sUnitsPerSecond;
-		uint32_t milliSeconds = milliSecondsTimeTen/10;
-		uint32_t percentTimesTen = (partTime*1000)/totalTime;
+		uint32_t milliSecondsTimesHundred = (uint32_t)((partTime*100000)/sUnitsPerSecond);
+		uint32_t milliSeconds = (uint32_t)(milliSecondsTimesHundred/100);
+		uint32_t percentTimesTen = (uint32_t)((partTime*1000)/totalTime);
 		uint32_t percent = percentTimesTen/10;
-		fprintf(stderr, "%s: %u.%u milliseconds (%u.%u%%)\n", msg, milliSeconds, milliSecondsTimeTen-milliSeconds*10, percent, percentTimesTen-percent*10);
+		if ( milliSeconds >= 100 )
+			dyld::log("%s: %u.%02u milliseconds (%u.%u%%)\n", msg, milliSeconds, milliSecondsTimesHundred-milliSeconds*100, percent, percentTimesTen-percent*10);
+		else if ( milliSeconds >= 10 )
+			dyld::log("%s:  %u.%02u milliseconds (%u.%u%%)\n", msg, milliSeconds, milliSecondsTimesHundred-milliSeconds*100, percent, percentTimesTen-percent*10);
+		else
+			dyld::log("%s:   %u.%02u milliseconds (%u.%u%%)\n", msg, milliSeconds, milliSecondsTimesHundred-milliSeconds*100, percent, percentTimesTen-percent*10);
 	}
 	else {
-		uint32_t secondsTimeTen = (partTime*10)/sUnitsPerSecond;
-		uint32_t seconds = secondsTimeTen/100;
-		uint32_t percentTimesTen = (partTime*1000)/totalTime;
+		uint32_t secondsTimeTen = (uint32_t)((partTime*10)/sUnitsPerSecond);
+		uint32_t seconds = secondsTimeTen/10;
+		uint32_t percentTimesTen = (uint32_t)((partTime*1000)/totalTime);
 		uint32_t percent = percentTimesTen/10;
-		fprintf(stderr, "%s: %u.%u seconds (%u.%u%%)\n", msg, seconds, secondsTimeTen-seconds*10, percent, percentTimesTen-percent*10);
+		dyld::log("%s: %u.%u seconds (%u.%u%%)\n", msg, seconds, secondsTimeTen-seconds*10, percent, percentTimesTen-percent*10);
 	}
 }
 
 static char* commatize(uint64_t in, char* out)
 {
-	char* result = out;
-	char rawNum[30];
-	sprintf(rawNum, "%llu", in);
-	const int rawNumLen = strlen(rawNum);
-	for(int i=0; i < rawNumLen-1; ++i) {
-		*out++ = rawNum[i];
-		if ( ((rawNumLen-i) % 3) == 1 )
-			*out++ = ',';
-	}
-	*out++ = rawNum[rawNumLen-1];
-	*out = '\0';
-	return result;
-} 
-
-
-void ImageLoader::printStatistics(unsigned int imageCount)
-{
-	uint64_t totalTime = fgTotalLoadLibrariesTime + fgTotalRebaseTime + fgTotalBindTime + fgTotalNotifyTime + fgTotalInitTime;
+	uint64_t div10 = in / 10;
+	uint8_t delta = in - div10*10;
+	char* s = &out[32];
+	int digitCount = 1;
+	*s = '\0';
+	*(--s) = '0' + delta;
+	in = div10;
+	while ( in != 0 ) {
+		if ( (digitCount % 3) == 0 )
+			*(--s) = ',';
+		div10 = in / 10;
+		delta = in - div10*10;
+		*(--s) = '0' + delta;
+		in = div10;
+		++digitCount;
+	}
+	return s;
+}
+
+
+void ImageLoader::printStatistics(unsigned int imageCount, const InitializerTimingList& timingInfo)
+{
+	uint64_t totalTime = fgTotalLoadLibrariesTime  + fgTotalRebaseTime + fgTotalBindTime + fgTotalWeakBindTime + fgTotalDOF + fgTotalInitTime;
+
+	uint64_t totalDyldTime = totalTime - fgTotalDebuggerPausedTime - fgTotalRebindCacheTime;
+	printTime("Total pre-main time", totalDyldTime, totalDyldTime);
+	printTime("         dylib loading time", fgTotalLoadLibrariesTime-fgTotalDebuggerPausedTime, totalDyldTime);
+	printTime("        rebase/binding time", fgTotalRebaseTime+fgTotalBindTime+fgTotalWeakBindTime-fgTotalRebindCacheTime, totalDyldTime);
+	printTime("            ObjC setup time", fgTotalObjCSetupTime, totalDyldTime);
+	printTime("           initializer time", fgTotalInitTime-fgTotalObjCSetupTime, totalDyldTime);
+	dyld::log("           slowest intializers :\n");
+	for (uintptr_t i=0; i < timingInfo.count; ++i) {
+		uint64_t t = timingInfo.images[i].initTime;
+		if ( t*50 < totalDyldTime )
+			continue;
+		dyld::log("%30s ", timingInfo.images[i].shortName);
+		if ( strncmp(timingInfo.images[i].shortName, "libSystem.", 10) == 0 )
+			t -= fgTotalObjCSetupTime;
+			printTime("", t, totalDyldTime);
+	}
+	dyld::log("\n");
+}
+
+void ImageLoader::printStatisticsDetails(unsigned int imageCount, const InitializerTimingList& timingInfo)
+{
+	uint64_t totalTime = fgTotalLoadLibrariesTime  + fgTotalRebaseTime + fgTotalBindTime + fgTotalWeakBindTime + fgTotalDOF + fgTotalInitTime;
 	char commaNum1[40];
 	char commaNum2[40];
 
-	printTime("total time", totalTime, totalTime);
-	fprintf(stderr, "total images loaded:  %d (%d used prebinding)\n", imageCount, fgImagesWithUsedPrebinding);
-	printTime("total images loading time", fgTotalLoadLibrariesTime, totalTime);
-	fprintf(stderr, "total rebase fixups:  %s\n", commatize(fgTotalRebaseFixups, commaNum1));
-	printTime("total rebase fixups time", fgTotalRebaseFixups, totalTime);
-	fprintf(stderr, "total binding fixups: %s\n", commatize(fgTotalBindFixups, commaNum1));
-	printTime("total binding fixups time", fgTotalBindTime, totalTime);
-	fprintf(stderr, "total bindings lazily fixed up: %s of %s\n", commatize(fgTotalLazyBindFixups, commaNum1), commatize(fgTotalPossibleLazyBindFixups, commaNum2));
-	printTime("total notify time time", fgTotalNotifyTime, totalTime);
-	printTime("total init time time", fgTotalInitTime, totalTime);
+	printTime("  total time", totalTime, totalTime);
+	dyld::log("  total images loaded:  %d (%u from dyld shared cache)\n", imageCount, fgImagesUsedFromSharedCache);
+	dyld::log("  total segments mapped: %u, into %llu pages with %llu pages pre-fetched\n", fgTotalSegmentsMapped, fgTotalBytesMapped/4096, fgTotalBytesPreFetched/4096);
+	printTime("  total images loading time", fgTotalLoadLibrariesTime, totalTime);
+	printTime("  total load time in ObjC", fgTotalObjCSetupTime, totalTime);
+	printTime("  total debugger pause time", fgTotalDebuggerPausedTime, totalTime);
+	printTime("  total dtrace DOF registration time", fgTotalDOF, totalTime);
+	dyld::log("  total rebase fixups:  %s\n", commatize(fgTotalRebaseFixups, commaNum1));
+	printTime("  total rebase fixups time", fgTotalRebaseTime, totalTime);
+	dyld::log("  total binding fixups: %s\n", commatize(fgTotalBindFixups, commaNum1));
+	if ( fgTotalBindSymbolsResolved != 0 ) {
+		uint32_t avgTimesTen = (fgTotalBindImageSearches * 10) / fgTotalBindSymbolsResolved;
+		uint32_t avgInt = fgTotalBindImageSearches / fgTotalBindSymbolsResolved;
+		uint32_t avgTenths = avgTimesTen - (avgInt*10);
+		dyld::log("total binding symbol lookups: %s, average images searched per symbol: %u.%u\n", 
+				commatize(fgTotalBindSymbolsResolved, commaNum1), avgInt, avgTenths);
+	}
+	printTime("  total binding fixups time", fgTotalBindTime, totalTime);
+	printTime("  total weak binding fixups time", fgTotalWeakBindTime, totalTime);
+	printTime("  total redo shared cached bindings time", fgTotalRebindCacheTime, totalTime);
+	dyld::log("  total bindings lazily fixed up: %s of %s\n", commatize(fgTotalLazyBindFixups, commaNum1), commatize(fgTotalPossibleLazyBindFixups, commaNum2));
+	printTime("  total time in initializers and ObjC +load", fgTotalInitTime-fgTotalObjCSetupTime, totalTime);
+	for (uintptr_t i=0; i < timingInfo.count; ++i) {
+		uint64_t t = timingInfo.images[i].initTime;
+		if ( t*1000 < totalTime )
+			continue;
+		dyld::log("%42s ", timingInfo.images[i].shortName);
+		if ( strncmp(timingInfo.images[i].shortName, "libSystem.", 10) == 0 )
+			t -= fgTotalObjCSetupTime;
+		printTime("", t, totalTime);
+	}
+	
 }
 
 
@@ -947,105 +1218,130 @@
 }
 
 
-void Segment::map(int fd, uint64_t offsetInFatWrapper, intptr_t slide, const ImageLoader::LinkContext& context)
-{
-	vm_offset_t fileOffset = this->getFileOffset() + offsetInFatWrapper;
-	vm_size_t size = this->getFileSize();
-	void* requestedLoadAddress = (void*)(this->getPreferredLoadAddress() + slide);
-	int protection = 0;
-	if ( !this->unaccessible() ) {
-		if ( this->executable() )
-			protection   |= PROT_EXEC;
-		if ( this->readable() )
-			protection   |= PROT_READ;
-		if ( this->writeable() )
-			protection   |= PROT_WRITE;
-	}
-	void* loadAddress = mmap(requestedLoadAddress, size, protection, MAP_FILE | MAP_FIXED | MAP_PRIVATE, fd, fileOffset);
-	if ( loadAddress == ((void*)(-1)) )
-		throwf("mmap() error %d at address=0x%08lX, size=0x%08lX in Segment::map() mapping %s", errno, (uintptr_t)requestedLoadAddress, (uintptr_t)size, this->getImage()->getPath());
-	
-	if ( context.verboseMapping )
-		fprintf(stderr, "%18s at %p->%p\n", this->getName(), loadAddress, (char*)loadAddress+this->getFileSize()-1);
-}
-
-void Segment::map(const void* memoryImage, intptr_t slide, const ImageLoader::LinkContext& context)
-{
-	vm_address_t loadAddress = this->getPreferredLoadAddress() + slide;
-	vm_address_t srcAddr = (uintptr_t)memoryImage + this->getFileOffset();
-	vm_size_t size = this->getFileSize();
-	kern_return_t r = vm_copy(mach_task_self(), srcAddr, size, loadAddress);
-	if ( r != KERN_SUCCESS ) 
-		throw "can't map segment";
-		
-	if ( context.verboseMapping )
-		fprintf(stderr, "%18s at %p->%p\n", this->getName(), (char*)loadAddress, (char*)loadAddress+this->getFileSize()-1);
-}
-
-void Segment::setPermissions()
-{
-	vm_prot_t protection = 0;
-	if ( !this->unaccessible() ) {
-		if ( this->executable() )
-			protection   |= VM_PROT_EXECUTE;
-		if ( this->readable() )
-			protection   |= VM_PROT_READ;
-		if ( this->writeable() )
-			protection   |= VM_PROT_WRITE;
-	}
-	vm_address_t addr = this->getActualLoadAddress();
-	vm_size_t size = this->getSize();
-	const bool setCurrentPermissions = false;
-	kern_return_t r = vm_protect(mach_task_self(), addr, size, setCurrentPermissions, protection);
-	if ( r != KERN_SUCCESS ) 
-		throw "can't set vm permissions for mapped segment";
-}	
-
-void Segment::tempWritable()
-{
-	vm_address_t addr = this->getActualLoadAddress();
-	vm_size_t size = this->getSize();
-	const bool setCurrentPermissions = false;
-	kern_return_t r = vm_protect(mach_task_self(), addr, size, setCurrentPermissions, VM_PROT_WRITE | VM_PROT_READ);
-	if ( r != KERN_SUCCESS ) 
-		throw "can't set vm permissions for mapped segment";
-}
-
-
-bool Segment::hasTrailingZeroFill()
-{
-	return ( this->writeable() && (this->getSize() > this->getFileSize()) );
-}
-
-
-uintptr_t Segment::reserveAnAddressRange(size_t length, const ImageLoader::LinkContext& context)
-{
-	vm_address_t addr = 0;
-	vm_size_t size = length;
-	if ( context.slideAndPackDylibs ) {
-		addr = (fgNextNonSplitSegAddress - length) & (-4096); // page align
-		kern_return_t r = vm_allocate(mach_task_self(), &addr, size, false /*use this range*/);
-		if ( r != KERN_SUCCESS ) 
-			throw "out of address space";
-		fgNextNonSplitSegAddress = addr;
-	}
-	else {
-		kern_return_t r = vm_allocate(mach_task_self(), &addr, size, true /*find range*/);
-		if ( r != KERN_SUCCESS ) 
-			throw "out of address space";
-	}
-	return addr;
-}
-
-bool Segment::reserveAddressRange(uintptr_t start, size_t length)
-{
-	vm_address_t addr = start;
-	vm_size_t size = length;
-	kern_return_t r = vm_allocate(mach_task_self(), &addr, size, false /*only this range*/);
-	if ( r != KERN_SUCCESS ) 
-		return false;
-	return true;
-}
-
-
-
+//
+// This function is the hotspot of symbol lookup.  It was pulled out of findExportedSymbol()
+// to enable it to be re-written in assembler if needed.
+//
+const uint8_t* ImageLoader::trieWalk(const uint8_t* start, const uint8_t* end, const char* s)
+{
+	//dyld::log("trieWalk(%p, %p, %s)\n", start, end, s);
+	++fgSymbolTrieSearchs;
+	const uint8_t* p = start;
+	while ( p != NULL ) {
+		uintptr_t terminalSize = *p++;
+		if ( terminalSize > 127 ) {
+			// except for re-export-with-rename, all terminal sizes fit in one byte
+			--p;
+			terminalSize = read_uleb128(p, end);
+		}
+		if ( (*s == '\0') && (terminalSize != 0) ) {
+			//dyld::log("trieWalk(%p) returning %p\n", start, p);
+			return p;
+		}
+		const uint8_t* children = p + terminalSize;
+		if ( children > end ) {
+			dyld::log("trieWalk() malformed trie node, terminalSize=0x%lx extends past end of trie\n", terminalSize);
+			return NULL;
+		}
+		//dyld::log("trieWalk(%p) sym=%s, terminalSize=%lu, children=%p\n", start, s, terminalSize, children);
+		uint8_t childrenRemaining = *children++;
+		p = children;
+		uintptr_t nodeOffset = 0;
+		for (; childrenRemaining > 0; --childrenRemaining) {
+			const char* ss = s;
+			//dyld::log("trieWalk(%p) child str=%s\n", start, (char*)p);
+			bool wrongEdge = false;
+			// scan whole edge to get to next edge
+			// if edge is longer than target symbol name, don't read past end of symbol name
+			char c = *p;
+			while ( c != '\0' ) {
+				if ( !wrongEdge ) {
+					if ( c != *ss )
+						wrongEdge = true;
+					++ss;
+				}
+				++p;
+				c = *p;
+			}
+			if ( wrongEdge ) {
+				// advance to next child
+				++p; // skip over zero terminator
+				// skip over uleb128 until last byte is found
+				while ( (*p & 0x80) != 0 )
+					++p;
+				++p; // skip over last byte of uleb128
+				if ( p > end ) {
+					dyld::log("trieWalk() malformed trie node, child node extends past end of trie\n");
+					return NULL;
+				}
+			}
+			else {
+ 				// the symbol so far matches this edge (child)
+				// so advance to the child's node
+				++p;
+				nodeOffset = read_uleb128(p, end);
+				if ( (nodeOffset == 0) || ( &start[nodeOffset] > end) ) {
+					dyld::log("trieWalk() malformed trie child, nodeOffset=0x%lx out of range\n", nodeOffset);
+					return NULL;
+				}
+				s = ss;
+				//dyld::log("trieWalk() found matching edge advancing to node 0x%lx\n", nodeOffset);
+				break;
+			}
+		}
+		if ( nodeOffset != 0 )
+			p = &start[nodeOffset];
+		else
+			p = NULL;
+	}
+	//dyld::log("trieWalk(%p) return NULL\n", start);
+	return NULL;
+}
+
+
+	
+uintptr_t ImageLoader::read_uleb128(const uint8_t*& p, const uint8_t* end)
+{
+	uint64_t result = 0;
+	int		 bit = 0;
+	do {
+		if (p == end)
+			dyld::throwf("malformed uleb128");
+
+		uint64_t slice = *p & 0x7f;
+
+		if (bit > 63)
+			dyld::throwf("uleb128 too big for uint64, bit=%d, result=0x%0llX", bit, result);
+		else {
+			result |= (slice << bit);
+			bit += 7;
+		}
+	} while (*p++ & 0x80);
+	return result;
+}
+
+
+intptr_t ImageLoader::read_sleb128(const uint8_t*& p, const uint8_t* end)
+{
+	int64_t result = 0;
+	int bit = 0;
+	uint8_t byte;
+	do {
+		if (p == end)
+			throw "malformed sleb128";
+		byte = *p++;
+		result |= (((int64_t)(byte & 0x7f)) << bit);
+		bit += 7;
+	} while (byte & 0x80);
+	// sign extend negative numbers
+	if ( (byte & 0x40) != 0 )
+		result |= (-1LL) << bit;
+	return result;
+}
+
+
+VECTOR_NEVER_DESTRUCTED_IMPL(ImageLoader::InterposeTuple);
+VECTOR_NEVER_DESTRUCTED_IMPL(ImagePair);
+
+
+